Search Results: "acid"

30 April 2013

Gunnar Wolf: Activities facing the next round of Trans-Pacific Partnership negotiations ( #yaratpp #tpp #internetesnuestra )

Excuse me for the rush and lack of organization... But this kind of things don't always allow for proper planning. So, please bear with my chaos ;-) What is the Trans-Pacific Partnership? Yet another secretely negotiated international agreement that, among many chapters, aims at pushing a free-market based economy, as defined by a very select few Most important to me, and to many of my readers: It includes important chapters on intellectual property and online rights. Hundreds of thousands of us along the world took part in different ways on the (online and "meat-space") demonstrations against the SOPA/PIPA laws back in February 2012. We knew back then that a similar project would attempt to bite us back: Well, here it is. Only this time, it's not only covering copyright, patents, trademark, reverse engineering, etc. TPP is basically a large-scale free trade agreement on steroids. The issue that we care about now is just one of its aspects. Thus, it's way less probable we can get a full stop for TPP as we got for SOPA. But we have to get it on the minds of as many people as possible! Learn more with this infography distributed by the EFF. Which countries? The countries currently part of TPP are Chile, Peru, New Zealand, Australia, Malaysia, Brunei, Singapore, Vietnam And, of course, the USA. Mexico, Canada and Japan are in the process of joining the partnership. A group of Mexican senators are travelling to Lima to take part of this round. Image by Colin Beardon (It's Our Future, NZ) What are we doing about it? As much as possible! I tried to tune in with Peru's much more organized call The next round of negotiations will be in Lima, Peru, between May 14 and 24. Their activities are wildly more organized than ours: They are planning a weekend-long Camping for Internet freedom, with 28 hours worth of activities. As for us, our activities will be far more limited, but I still hope to have an interesting session: Poster design by Gacela. Thanks! This Friday, we will have Aula Magna, Facultad de Ingenier a, UNAM, M xico DF, from 10AM and until 3PM. We do not have a clear speakers program, as the organization was quite rushed. I have invited several people who I know will be interesting to hear, and I expect a good part of the discussion to be a round table. I expect we will:
  1. Introduce people working on different corners of this topic
  2. Explain in some more detail what TPP is about
  3. Come up with actions we can take to influence Mexico's joining of TPP
  4. And this will be at Facultad de Ingenier a. Another explicit goal of this session will be, of course, to bring the topic closer to the students!
We want you! So... I am posting this message also as a plead for help. Do you think you can participate here? Were you among the local organizers for the anti-SOPA movement? Do you have some insight on TPP you can share? Do you have some gear to film+encode the talks? (as they will surely be interesting!) Or, is the topic just interesting for you? Well, please come and join us! Some more informative links BE THERE! So, again: Friday, 2012-05-03, 10:00-15:00 [Update] So, 2012-05-03 came and went. And thankfully, Alfredo was there to record most of the talk! So, you can download the video: Gunnar Wolf, Salvador Alc ntar: Qu es TPP? Por qu me debe preoucpar? Qu podemos hacer?
AttachmentSize
Poster. Design by Gacela Thanks!457.49 KB
Infography about TPP distributed by the EFF392.45 KB
"Here, let me sign this for you". Image by Colin Beardon.27.08 KB

19 April 2013

Gunnar Wolf: Of European descent

A colleague of mine at Facultad de Ingenier a pointed me to a note published in the Faculty's gazette about a short cycle of talks we had on April 4th, trying to get life and interest back in the once-active LIDSOL (Laboratorio de Investigaci n y Desarrollo en Software Libre, Free Software Research and Development Laboratory), which nowadays lies mostly dormant. Good thing the official communication channels got notice of this! Only I am not sure if they can properly produce Spanish (as this feels more like an English redaction). Quoting only the first lines of the paragraph that referes to me:
La ltima conferencia fue presentada por Gunnar Wolf, que aunque su nombre nos hiciera pensar en una nacionalidad europea, l es nacido en tierras mexicanas pero con descendencias h ngaras, austriacas y polacas.
Which translates to:
The last talk was presented by Gunnar Wolf, that although he has a name that makes us think about an European nationality, he was born in Mexican soil, but with Hungarian, Austriac and Polish descent.
As far as I can tell (and I am almost sure I know all of the story At least on that regard), I have no descent yet. Not Hungarian, Austriac, Polish, nor of any nationality. (nitpickers: Yes, similar words are often used. In Spanish, it would be correct to say de ascendencia h ngara, austriaca y polaca, and in my attempt towards English translation, it would be of Hungarian, Austriac and Polish descent).

18 March 2013

Richard Hartmann: Bee happy

Finally.. My bee box has arrived. Initially I had planned to build it myself, but with current time constraints and in light of the fact that the commercial variant is built in a sheltered workshop, I decided to go for a pre-built one. The bee box is designed to give bees a natural habitat and allow them to get through the winter without the need for artificial sugar. Harvest is limited to about 15 kg in a good year as opposed to up to 50 kg in commercial beehives, but this method of beekeeping is less stressful for the bees. The trick is that there are two sections in every bee box; starting in the second year, you open the second section as soon as the bees have started to run out of space. As that's done relatively late in May, the bees will mainly build honey-only non-larvae honeycombs. During harvest, you remove only those secondary honeycombs; as a result, the bees will not need to defend their larvae and thus be a lot more relaxed. As those bees are under supervision of a human with access to oxalic acid, it's trivial to protect those bees against infestations by varroa destructor and to keep them safe form mice during winter. Bees are incredibly important for nature's cycle, so this is a hobby with a lot of positive impact on your local flora, and subsequently fauna. And hey.. free honey!

24 January 2013

Russell Coker: Power Supplies and Wires

For some time I ve been wondering how the wire size for power supplies limits the power. So I ve done some quick calculations to determine if it s a problem. The first type that is of interest are the Inverters that are used to convert 12VDC to 240VAC (mains power) to allow electric devices to be operated in a car. I ve seen some reports from dissatisfied user about Inverters not supplying as much power as expected and I ve had problems with my 150W Inverter not always supplying my Thinkpad (which definitely doesn t draw 150W). The second type is phone chargers as charging a phone in a reasonable amount of time is always a problem. Inverter Rating Fine Print vs Laptop PSU My Thinkpad Power Supply claims Efficiency Level IV which according to the US EPA document describing the efficiency marking protocol for external power supplies [1] means that it is at least 85% efficient when supplying 50W+. The peak output of the PSU is 4.5A at 20V which is 90W peak output, 90/0.85 == 106W power drawn. One would hope that wouldn t be a problem from a 150W PSU. But the fine print on the PSU says that it can provide 110W continuously and 150W for 10 minutes. So according to my calculations I m within 4W of overloading the PSU if my Thinkpad uses full power. It also says that it is designed for 13.8V input. I have no idea how the performance of the Inverter changes as the supply Voltage changes between the 12.6V that a 6 cell lead-acid battery is designed to provide and the 13.8V charge from the car alternator. But I have had occasions when my Inverter stopped working correctly presumably due to being unable to supply as much current as my Thinkpad draws. As an aside I measured the Voltage in my car (with the engine off) at 12.85V from the cigarette lighter socket and 13.02V directly from the battery. I wonder if there is some sort of overload protection on the cigarette lighter which has a side effect of reducing the Voltage. Resistance in wires reduces the Voltage, but all Voltage meters are designed to have a high resistance to prevent that from being an issue. If anyone has an explanation for the 0.17Volt drop then please write a comment! Can a Car Provide 130W from the Cigarette Lighter socket? If the Inverter is also 85% efficient (and it might be less as it has no indication of efficiency on the box) then when supplying 110W it would draw 110/0.85 == 129.4W (I ll round it up to 130W). The power in Watts is equal to the Voltage multiplied by the current in Amps (W=V*I). Therefore I=W/V so if the car battery was at 12.85V then 130W/12.85V == 10.12A will flow. The current that goes through a circuit is equal to the Voltage divided by the resistance (see the Wikipedia page on Ohm s law for more information). This also means that the resistance equals the Voltage divided by the current. 12.85V/10.12A == 1.27 Ohms. Note that this is the resistance of the entire circuit, all the wires going to the battery, the circuitry inside the Inverter, and the internal resistance of the battery. The Inverter s cable is 1M long (2 meters of wire) and each wire is about 3.5mm in diameter including the insulation which means that the copper wire is probably equivalent to a single core conductor that is about 1mm in diameter. According to one of the online guides to resistance [2] wire that is 1.02mm in diameter will have a resistance of 0.02 Ohms per meter which gives a resistance of 0.04 Ohms. 0.04 Ohms is 3% of the total resistance of the circuit which doesn t seem like it will be a real problem. In practice I ve noticed that the connector gets extremely hot when it s in use while the cable doesn t get warm enough to notice. I suspect that the quality of the connector limits the power that is available but I don t have an easy way of measuring this. Inverters that are rated at 300W are designed to attach directly to the battery. An Inverter that is rated at 300W would draw 300W/0.85 == 352W from the battery. That needs 352W/13.02V == 27.04A and therefore a circuit resistance of 13.02V/27.04A == 0.48 Ohms total resistance. I wonder whether dirt on the battery terminals would give a significant portion of that. Phone Charging I ve also been wondering about why mobile phones take so long to charge, and now I ve finally done the calculations. The latest standard for mobile phones is to use USB for charging. The Wikipedia page about USB says that the standard is for USB 2.0 to supply up to 500mA at 5V +-5%. That means 0.5A*5V == 2.5W +- 5%. If we assume that the internal power supply in a phone is also 85% efficient then that means 2.5*0.85 == 2.125W going to the battery. My Samsung Galaxy S3 has a battery which is rated at 7.98Wh. According to the Wikipedia page about Lithium Ion batteries the charge/discharge efficiency is 80% to 90% I ll assume that it s 85% for further calculations. If the battery in the phone is 85% efficient and the phone is doing nothing but charging then the charge time for a regular USB port would be 7.98Wh/0.85/2.125W == 4.42 hours (4 hours 25 minutes) of charge time. That probably means something closer to 5 hours to totally charge the phone while it s running. There are dedicated charging ports for USB which can supply up to 1.5A. The 3rd party charger which came with my phone was rated at 1A and would hopefully be capable of completely charging the phone in less than 3 hours (but in practice isn t). It s interesting to note that MacBooks expose the amount of current drawn from a USB port with a GUI, so it should be possible to measure a phone charge rate by connecting it to a MacBook (which is cheaper than cutting up a phone cable). My old Samsung Galaxy S has a battery which is rated at 5.55Wh, by the same calculations it would take slightly more than 3 hours to charge on a standard USB port or 1.5 hours on my newest USB charger. In practice it has never got anywhere close to that, I presume that the phone is designed to draw less than 500mA. Phone Cable Resistance The charger that came with my Galaxy S has a cable that is about 1.75M long, the cable is flat and measures just over 1mm thick and about 2mm wide. Presumably the wire is equivalent to a single core that s about 0.4mm in diameter thus giving it a resistance of about 0.134 Ohm per meter, or 1.75*2*0.134 == 0.469 Ohm for the cable. The charger is rated at 0.7A. To supply 0.7A at 5V the resistance would be 5V/0.7A == 7.143 Ohm so about 6.6% of the total resistance of the circuit would be in the wire from the charger to the phone. The charger that came with my Galaxy S3 has a round cable that s just over 3mm thick and about 90cm long. If each wire in the cable is equivalent to a solid wire that is 0.912mm in diameter then it would be 0.0264 Ohm per meter of wire or 0.9*2*0.0264 == 0.0475 Ohm. The total circuit resistance would be 5V/1A == 5 Ohm. So 0.0475 Ohm is less than 1% of the circuit resistance. Voltage Drop The Voltage across a part of a circuit is proportional to the resistance (see the Wikipedia page on Series and Parallel Circuits for a good explanation). Basically this means that if 1% of the resistance of a circuit is in the wire then 1% of the Voltage drop will also be in the wire, so if we have a 5V supply with my Galaxy S3 cable then each of the two wires in the cable will have a difference of about 0.025V between the ends and the phone will receive a supply of 4.95V, the difference isn t something that is worth worrying about. But the cable from my Galaxy S has a resistance equivalent to 6.6% of the circuit resistance which means that the theoretical charge time will be 6% longer than it might be or 6% more current will be drawn from the mains than should be needed. Conclusion The charger that came with my Samsung Galaxy S isn t much good. Wasting 6.6% of the power in the wire is unreasonable. Phones keep getting more power hungry and batteries keep getting larger. There are third party phone batteries and external batteries that are charged by USB which have more than twice the capacity of the stock phone batteries this means more than twice the charge time. This problem will keep getting worse. The problem of a phone in active use drawing more power than the charger can provide (and running out of battery while on the charger) seems likely to stay with us. So while an Android phone has the potential to be a great little embedded server it seems that hacking the power supply is going to be a required first step for realising that potential. The decision to make 5V the USB power standard was reasonable at the time as it was the voltage used for most things on the motherboard. The decision to use USB as the phone charging standard was also reasonable, it allows phones to be charged anywhere. The combination of those two decisions isn t good for the user. If a higher Voltage such as 12V was used then 5* the power could be supplied through the same wires at the same level of efficiency. It would be really good if cars came with built in Inverters and supplied 240VAC or 110VAC depending on the region they were manufactured for. It s becoming a fairly common feature to have a cigarette lighter port in the car boot as well as at least two ports inside the car. When a car has three sockets and only one device to actually light cigarettes (which I suspect is only provided to fill an empty socket) it s very obvious that people want to connect random devices. Also having USB charging ports inside the car would be a really good idea (one for each seat would be good for Ingress).

28 November 2012

Russ Allbery: Review: Emissaries from the Dead

Review: Emissaries from the Dead, by Adam-Troy Castro
Series: Andrea Cort #1
Publisher: Eos
Copyright: March 2008
ISBN: 0-06-144372-7
Format: Mass market
Pages: 387
As a small child, Andrea Cort was a colonist on Bocai, part of a utopian project to create a mixed human and Bocaian community. Until, that is, all the members of the community woke up one day and started horrifically murdering each other for reasons that none of the survivors could ever explain. Now, she's protected from extradition by a life contract with the Diplomatic Corps and serves them as a special investigator. The scene of the investigation of this book is the strange habitat One One One. The habitat was created by the AIsource, an alliance of artificial intelligences now independent of their original creators. It's in deep space, far from any sun, and would have remained entirely unknown to the other inhabitants of the galaxy if the AIsource hadn't announced its presence. The choice to announce it was baffling, since it contains a sentient species entirely under the control of the AIsource, something that's against the shared rules of all the other species, but which they wouldn't have known about if the AIsource hadn't drawn their attention to it. After extensive negotiations, one unofficial human research group has been allowed access, and now two of the members of that group have been murdered. That's where Andrea comes in. This is Castro's first original solo novel, but he has a background in short fiction in the SF, fantasy, and horror genres and some previous collaborations and shared universe writing. The horror shows through a bit more than I'd personally prefer: the preface briefly describing Andrea's past would have been sufficient, but Castro goes back and shows it in horrific and gruesome detail as a flashback. His fight scenes are also strangely and disturbingly detailed. If you have a sensitive stomach, be aware that you may want to skim some parts of this. The overall construction of this novel, though, is not horror. It's an SF murder mystery, about halfway between a procedural and a noir detective story. Andrea does follow a coherent procedure and uses an investigative technique more sophisticated than stirring the pot and seeing what jumps out, making it not quite noir, but it has the noir tendency towards story progress via attacks on the detective and quite a lot of ongoing tension. It also involves quite a lot of setup; be aware going in that we get over a hundred pages of description of the various research group members, the details of the crimes, possible motives, and the details of the artificial habitat without a lot of forward progress on understanding the crime. Castro puts a lot of work into the design of the habitat despite leaving it mostly in the background. It could easily serve as the backdrop of a more typical Big Dumb Object SF novel. The habitable zone where the research team is and where all of Andrea's investigations take place is the effective "top" of the habitat, covered in dense foilage to which the native sentient species clings and crawls its entire life. Below is an effectively infinite fall into crushing acidic atmosphere. Castro managed to not set off my dislike of heights too badly, in part because he focuses more on Andrea's own dislike of heights rather than vividly describing the drop, but it's a constant presence throughout the novel and adds a persistant background tension. It also leads to some minor but neat clashes of perspective in conversations with the native species. For most of the book, I would have described Emissaries from the Dead as an enjoyable but not horribly original detective novel with a neat science fiction background. But there are several interesting ending twists that I won't spoil and some decisions that quite surprised me. They don't have a large effect on the plot of this book, but they make for a fascinating hook and setup for later books in the series (and I see there is a sequel). It's definitely not the sort of thing that you want spoiled before reading this book, so avoid reading blurbs and details about the sequel before reading this one. I wouldn't go out of my way to hunt down this book, but it's solid, enjoyable detective SF with a surprisingly good ending. I can see why it won the Philip K. Dick award (for best SF paperback original). Mildly recommended. Followed by The Third Claw of God. Rating: 7 out of 10

22 November 2012

Cyril Brulebois: Another month, another beta

Today s recipe: Result: Debian Installer 7.0 Beta4 release! Speaking of which, shameless plug: I'm giving a Debian Installer talk at mini-DebConf Paris this sunday.

9 November 2012

Gunnar Wolf: Road trip to ECSL 2012 in Guatemala

Encuentro Centroamericano de Software Libre! Guatemala! During a national (for us) holiday, so it's easy to go without missing too much work time! How would I miss the opportunity? Several years ago, I started playing with the idea of having a road trip Probably this was first prompted with the UK crew and the Three Intrepid Motorcycle Riders arriving by land to DebConf 9 I don't know. Fact is, I wanted to go to DebConf10 in New York by land, as well as to DebConf12 in Nicaragua. Mostly due to a lack of time, I didn't Although we did start making some longish trips. Of course, my desire to show Regina what Mexico is like also helped! So, up until a week ago, our (according to my standards) long distance driving experience included:
  • M xico Guanajuato Puerto Vallarta Guanajuato M xico, in early November 2011, for Festival de Software Libre and with Regina and our Blender friends Octavio and Claudia. Totalling almost 1900Km, mostly consisting of wide, toll highway.
  • M xico Xilitla San Luis Potos M xico, in April 2012, just for fun and for a nice short vacation, alone with Regina. Totalling almost 1200Km, but through Sierra Gorda de Quer taro, a very tough stretch of about 250Km which we did at about 50Km/h on average. Beautiful route for sure! We didn't originally intend to go through San Luis Potos , and it does not appear to make much sense, as it adds ~350Km to the total, but it was even quicker than going back by the same route and according to those who now, even faster than our planned route, via Tamazunchale and Ixmiquilpan!
  • M xico San Luis Potos Zacatecas Aguascalientes Guanajuato M xico, in May 2012, for Congreso Internacional de Software Libre, again with Octavio and Claudia. Totalling 1250Km, and following very good roads, although most of them were toll-free.
But there is always a certain halo over crossing a border, maybe more so in countries as large as Mexico. We convinced Pooka and Moni, and granted, with some aprehension, as we knew of some important security risks in the more rural areas we wanted to go through we decided to go to Guatemala. And, although we wanted to go with a bit more time, Real Life took its toll: We could not take more time than the intersection of what our respective jobs offered. So, here goes a short(?) recap of our six day long, 3200Km trip. Of course, we have a map detailing this. Mexico Veracruz I came to my office early on Wednesday (31-oct), and left with Regina around 10AM towards Veracruz. We agreed to meet there with Moni and Pooka, who would take the night bus, and continue together. Crossing Mexico City proved to be the longest obstacle We arrived to Veracruz already past 3PM, and spent a nice evening walking down the center and port of the city. Veracruz port can still be seen as part of central Mexico; I knew the road quite well. Veracruz San Andr s Tuxtla Catemaco San Cristobal de las Casas We met with our friends at the iconic Gran Caf de la Parroquia at 6:30AM. Had a nice breakfast with coffee, and by 7:30 we were heading south-west. The reason to have a road trip was to get to know the route, to enjoy the countryside So, given we "only" had to make 650Km this day, we took the non-toll road A narrow path stretching along the coastal plains of Veracruz, until Acayucan. Doing so, we also saved some money, as the equivalent toll road is around MX$300 (~US$25)! Veracruz is a hot state. We ended up all sweaty and tired by 19:00, when we reached San Cristobal. We had agreed not to drive at night, due to security issues, but fortunately there was quite a bit of traffic both ways between Tuxtla Guti rrez (Chiapas State capital, around 1hr from San Cristobal, where darkness got us) and our destination, so we carried on. Now, San Cristobal is a high city, almost as high as Mexico City (2100m), and being more humid, it was quite chilly. We went for a walk, and were convinced that at a later time, we had to stay for several days there. The city is beautiful, the region is breath-taking, there is a lot of great handicrafts as well, and it's overall very cheap. Really lovely place. San Cristobal de las Casas Cd. Cuauht moc La Mesilla Guatemala Once again, this day started early. We woke up ready to leave at 7AM, and not earlier because the hotel's parking didn't open earlier. After a very quick visit to San Cristobal downtown, to take some photos that were not right the night before, we took the road to Comit n, stopping just for some tamales de bola y chipil n for breakfast. Central Chiapas is almost continuously populated, differing from most of my experience in Mexico. It is all humid, and has some very beautiful landscapes. We passed Comit n, which is a much larger city than what we expected, went downhill after La Trinitaria, crossed a plain, and continued until hills started taking over again. We stopped in a very chaotic, dirty place: Just accross the border, where Ciudad Cuauht moc becomes La Mesilla. This border was basically what we expected: There is no half-official place to exchange money, so we had to buy quetzales from somebody who offered them on the street, at MX$2 per Q1 (where the real exchange should be around 1.50 to 1). While on the road, I was half-looking for exchange posts in Comit n and onwards, and found none (and being a festive day, they would probably be closed anyway). But we were expecting this, after all, and exchanged just the basic minimum: MX$600 (US$50, which by magic became Q300, US$40). The tramit consists of:
  • Spraying the car against diseases (which has a cost of Q18)
  • Each of us has to go through migration. Note, in case you cross this border: We didn't expressly cross Mexican migration, so officially there was no record of us going out. Be sure to go through migration to avoid problems at re-entry!
    Migration has no cost.
  • Customs. As we were entering by car, I had to purchase a permit for circulation. I don't remember the exact quote, but it was around Q150, and the permit is valid for 90 days.
  • That's it! Welcome to Guatemala!
La Mesilla is in Guatemala's Huehuetenango Department, and from all of the Departments we crossed until Guatemala city (Huehuetenango, Quetzaltenango, Totonicap n, Solol , Chimaltenango, Sacatep quez and Guatemala), this is the largest one. Huehuetenango is home to the Cuchumatanes mountain ridge. We found beautiful, really steep, really fertile mountains. It is plainly amazing: Mountains over 60 , and quite often full with agricultural use Even at their steepest points! The CA-1 highway is, in general, in very good shape. There are however many (many, many) speed bumps (or topes, in Mexican terminology. Or t mulos in Guatemalan), at least a couple at every village we crossed, not always painted. The road is narrow and quite winding; it follows river streams for most of the way. We feared it would be in much worse shape, from what we have heard, but during the whole way we found only three points where the road was unusable due to landslides and an alternative road was always in place when we needed it. After Totonicap n, the narrow road becomes a wide (four lane) highway. Don't let that fool you! It still goes through the center of every village along the road, so it's really not meant for speeding. Also, even though the pavement is in very good condition, it is really steep quite often. It is not the easiest road to drive, but it's (again) by far not as bad as we expected. We arrived to Guatemala City as dawn was falling, and got promptly lost. Guatemala has a very strange organization scheme: The city is divided in several zones, laid out in a swirl-like fashion. East-west roads are called Calle and North-south roads are called Avenida (except for zona 4, I think, where they are diagonal, and some are Rutas while the others are V as). I won't go into too much detail). Thing is, many people told us it's a foolproof design, and people from different countries understand the system perfectly. We didn't... At least not when we arrived. We got quite lost, and it took us around one hour to arrive to our hotel, at almost 19:00 Almost 12 hours since we left San Cristobal. Went for a quick dinner, and then waited for our friends to arrive after the first day of work of ECSL, which we missed completely. And, of course, we were quite tired, so we didn't stay up much longer. Antigua Guatemala On Saturday, ECSL's activities started after 14:00 so we almost-kidnapped Wences, the local organization lead, and took him to show us around Antigua Guatemala. Antigua was the capital of Guatemala until an earthquake destroyed it in the 1770s; the capital was moved to present-day Guatemala city, but Antigua was never completely abandoned. Today, it is a world heritage site, a beautiful city, where we could/should have stayed for several days. But we were there for the conference, so we were in Antigua just a couple of hours, and headed back to Guatemala. Word of caution: Going from Guatemala to Antigua, we went down via the steepest road I have ever driven. Again, a real four-lane highway... but quite scary! The main focus for this post is to give some roadtrip advice to potential readers... So, this time around, I won't give much detail regarding ECSL. It was quite interesting, we had some very good discussions... but it would take me too much space to talk about it! The road back: Guatemala Tec n Um n; Cd. Hidalgo Arriaga So, about the road back: Yes, we just spent three days getting to Guatemala City. We were there only for ~36 hours. And... We needed to be here by Tuesday morning no matter what. So, Sunday at noon we said goodbye to our good friends in ECSL and started the long way back. To get to know more of Guatemala, we went back by the CA-2 highway, which goes via the coastal plains Not close to the Pacific ocean, which we didn't get to see at all, but not through the mountains. To get to CA-2, we took CA-9 from Guatemala. If I am not mistaken, this is the only toll road in Guatemala (at least, the only we used, and we used some pretty good highways!) It is not expensive; I don't remember right now, but must have been around Q20 (US$3). Went South past Palin and until CA-2, just outside Escuintla city, and headed West. All of Escuintla and Suchitep quez it is again a four lane highway; somewhere in Retalhueu it becomes a two lane highway. We were strongly advised not to take this road at night because, as the population density is significantly lower than in CA-1, it can get lonely at times And there are several reports of robberies. We did feel the place much less populated, but saw nothing suspicious in any way. Something important: There are almost no speedbumps in CA-2! The terrain stayed quite flat and easy as we crossed Quetzaltenango, and only in San Marcos we found some interesting hills and a very strong rain that would intermitetntly accompany us for the rest of the ride. So, we finally arrived to the border city of Tec n Um n at around 16:30 Approximately four hours after leaving the capital. The Tec n Um n Cd. Hidalgo cities and border pass are completely different from the disorderly and dirty Cd. Cuauht moc La Mesilla ones. The city of Tec n Um n could be just a nice town anywhere in the country, it does not feel aggressive as most border cities I have seen in our continent. We stopped to eat at El pollo campero and headed to the border. In the Mexican side, we also saw a very well consolidated, big and ordered migration area. Migration officers were very kind and helpful As we left Cd. Cuauht moc, Regina didn't get a stamp of leaving Mexico, so technically she was ilegally out of the country (as she is not a national... They didn't care about the rest of us). The tramit to fix this was easy, simple, straightforward. We only paid for the fumigation again (MX$60, US$5), and were allowed to leave. Anyway, we crossed the border. There is a ~30Km narrow road between Cd. Hidalgo and Tapachula, but starting in Tapachula we went on Northwards via a very good, four lane and very straight highway. Even though we had agreed not to drive at night... Well, we were quite hurried and still too far from Mexico City, so we decided to push it for three more hours, following the coastline until the city of Arriaga, almost at the border between Chiapas and Oaxaca. Found a little hotel to sleep some hours and collapsed. Word of warning: This road (from Tapachula to Arriaga) is also known for its robberies. We saw only one suspicious thing: Two guys were pushing up their motorcycle, from which they had apparently fallen. We didn't stop, as they looked healthy and not much in need of help, but later on talked about this Even though this was at night, they were not moving as if they had just crashed; nothing was scratched, not the motorcycle and not their clothes. That might have been an attempt to mug us (or whoever stopped by). This highway is very lonely, and the two directions are separated by a wall of vegetation, so nobody would have probably seen us were we to stop for some minutes. Be aware if you use this road! The trip comes to an end: Arriaga Niltepec Istmo C rdoba M xico The next (last, finally!) day, we left at 6:30AM. After driving somewhat over one hour, we arrived to Niltepec, where a group of taxi drivers had the highway closed as a protest against their local government's tolerance of mototaxis. We evaluated going back to Arriaga and continue via the Tuxtla Guti rrez highway, but that would have been too long. We had a nice breakfast of tlayudas (which resulted in Pooka getting an alergic reaction shortly afterwards) and, talking with people here and there, were told about an alternative route by an agricultural road that surrounds the blockade. So, we took this road the best way we could, and after probably 1hr of driving at 20Km/h, finally came back to the main road. We planned on crossing the isthmus using the Acayucan-Juchit n road We were amazed at the La Ventosa ("the windy") area, where we crossed a huge eolic plant for electricity generation, so of course we got our good share of photos. From then onwards, not much more worth mention. Crossed the isthmus via a quite secondary road in not too good shape (although there is a lot of machinery, and the road will much likely improve in the next few months/years), then took the toll freeway along Veracruz until C rdoba. We stopped for a (delilcious and revigorizing!) cup of coffee in Hotel Zeballos, where Agust n de Iturbide signed with Viceroy Juan O'Donoj the treaties that granted Mexico the independence. Traveller, beware: When crossing between Puebla and Veracruz, there is a steep slope of almost 1000m where , you will almost always (except if it's close to noon) find very thick fog; taking the highway from C rdoba, this is in the region known as Cumbres de Maltrata. We had the usual fog, and just as we left it, a thin but constant rain that went on with us up until we got home. Crossed Puebla state with no further eventualities, and arrived to Pooka and Moni's house by 22:00. Less than one hour later, Regina and me arrived home as well. This was four days ago... and I have finally finished writing it all down ;-) Hope you find this useful, or if not, at least entertaining! If you read this post in my blog, you will find many pictures taken along the trip below (Well, if you are reading the right page, not in the general blog index...). If you are reading from a planet or other syndication service... Well, come to the blog! Dreamhost woes Oh, and... Yes, it sometimes happens: My blog is hosted at Dreamhost. This means that usually it works correctly... But sometimes, specially when many people request many nontrivial pages, it just gives an error. If you get an error, reload once or twice... Or until your patience manages ;-)

4 September 2012

Gunnar Wolf: To CURP or not to CURP

To CURP or not to CURP
CURP: Clave nica del Registro Poblacional, or Unique Population Registry Code. This is a (hopefully) unique, 18 character long, string identifying each Mexican - I won't get into the technicalities, but serve yourselves. By following such a convoluted scheme, the authorities should have ensured a biunivocal relation between each person and their CURP number. Well, at some point, due to a bureaucratical mishap completely outside my hands (my patron registered me with the wrong birth date, as you can see in the page at the bottom), I got two CURPs - And the procedure to fix it was far from trivial. Last Sunday, I entered the Consulta CURP system to print a copy of the official document. Much to my surprise... It answered that I was not registered! A couple of minutes later, I tried again, and succeeded. But I could not refrain from printing my Certificate of non-registration. I guess their system follows a strong-but-stupid scheme such as:
  1. begin
  2. db = connect_to_database
  3. curp = find_curp_for_person(query)
  4. generate_document(curp)
  5. rescue
  6. generate_non_reg_certificate(query)
So, right, if a user submits a query during the system maintenance window (after all, it was Sunday after 23:00), the system will fail to connect to the database (or whatever), raise an exception, trap it, and... Well, you no longer exist, thanks for playing!

4 May 2012

John Goerzen: Geeky plan: Solar power supply IN THE CAR

From the might be geeky dept For an upcoming car trip, we have to take my wife s car (long story). I will be taking two large lead-acid batteries in the trunk hooked up to a solar panel in the rear window area and, of course, some electronics in the front seat. Why, you ask? While she drives, I will be working via tethered 3G (conveniently reducing the number of vacation days the trip requires). This is Kansas, so signals are weak sometimes. I have an external antenna that hooks up to a signal booster. So I ll be running a laptop, cellphone in draw lots of power mode , and a cellphone booster at minimum. Measurements suggest that this combination could easily put me in range of the typical 10A limit of dash electronics. (And doesn t even include the nice to haves of GPS, my handheld radio, and the amplifier for it.) My car has a direct high-current link from the battery to the trunk to support the 100W amateur radio mounted there. It is pretty easy to tap into it and add a cable that runs to the passenger seat to run all this stuff. Terah s car doesn t. So, I thought, what s the easy solution? Well, my solar power system, of course! If I charge up a couple of the large batteries beforehand (just pop them and a few panels in the sun for a day), then put the batteries in the trunk, it will probably power my electronics for a whole day (enough for the trip we have planned), and I have already cabled them up to support the kind of current draw I ll have. I ll have to recharge the batteries at the destination, of course, so I ll bring along a panel (no need to bring more than one since there will be plenty of time to charge). Once I m planning to take a panel along, I figured I might as well put it under the rear window so it can actually help charge the batteries as we go. The current drain will, of course, be larger than the 1A or so it can put out, but hey, who else drives down the interstate with an active solar panel in their car? I can actually split the load between the batteries and the vehicle system too, so I do not need a continuous 10A draw on the batteries. The sad part about this is I will probably never surpass a temporary battery system with a solar panel in terms of geeky travel.

16 April 2012

Gunnar Wolf: Biking over Cd. Nezahualc yotl

April 15 2012, my friend Alberto and I took on a difficult mission: Cross the allegedly biggest city in the world and conquer Ciudad Nezahualc yotl, one of its populous and famous districts. Alberto had been to Cd. Neza a couple of times, as he is one of the providers for a physical rehabilitation center built in it, but I had never set foot in it. My friend Al and me started cycling in col. Escand n, in Mexico's Center-West, followed roughly along Metrob s' line 2 until its terminal, and at Cabeza de Ju rez entered Cd. Neza. We went along the main avenue "Adolfo L pez Mateos" until Bordo de Xochiaca, then all straight until V a Tapo, almost all around the airport, got lost a couple of times in the way, then back to the heart of the city. I took only a couple of quick shots, which I have uploaded to this album We saw so much, so huge, so surreal things, but the main goal we set for this was just to enjoy cycling. I can just complain about one thing: We cycled for maybe 10Km following the main open sewage line in Mexico City. I had never breathed so much shit in my life take it as literally as you want. But, all in all, an interesting little trip.

9 April 2012

Gunnar Wolf: Xilitla

On this Semana Santa (holy/major week), Regina and I took a little vacation: We went ~400Km North, to the magical Xilitla, in the Eastern part of San Luis Potos state. To get there, we went by the Sierra Gorda de Quer taro route: A beautiful but quite hard to drive road, crossing desert, forest and jungle through a very steep mountain ridge. What does hard to drive mean? It means that for ~200Km we had a speed average of 40-50Km/h. The road is in very good conditions, and traffic was quite light. And although our plans were to come back via the other ridge road (crossing Hidalgo state instead of Quer taro), we were persuaded to go the long way instead: We came back via San Luis Potos city, making ~700Km instead of ~400, but I'll concede it was a much easier drive. But although I take the road as an important part of the vacation, and although it was a very quick vacation, what is it we went to see there? Xilitla is a town at the beginning of the huasteca potosina region, with really exuberant vegetation, that captured Sir Edward James' heart back in the 1940s. Sir Edward, a noble Englishman, was good friends with several surrealist artists, and became one himself. After moving to Xilitla and buying an impressive chunk of jungle, in the 1960s he started building a surrealist garden in the middle of the jungle, which he continued to work on until his death, in 1984. We took some pictures, but of course, they pay very little tribute to the magic and beauty of the place. And going to the huasteca means going to places of nature, of many crystaline rivers. Yes, only three days (two of them spent getting there and back) are far too little to enjoy it. But even so, we went to the birth of river Huichihuay n (~45 minutes North of Xilitla) and to the Los Micos waterfalls (~20 minutes West of Ciudad Valles). Very nice places to visit, among so many others. We should go back to the huasteca soon! I uploaded many of the pictures here. They will not be syndicated on the planets that follow my blog on RSS (or for individuals following RSS, FWIW), but you will find them following the relevant links. And of course: I pay for a very cheap package on my hosting provider. Drupal often answers with an error page when the server is (even mildly) overloaded. So, feel free to hit reload if something appears unavailable.

24 February 2012

Julien Danjou: 10 years as a Debian developer

Ten years ago, I joined the Debian project as a developer. At that time, I was 18 and in my first year at university, hanging out with the TuxFamily system administrators, which included 3 french Debian developers (sjg, igenibel and creis). I was learning Debian packaging while working on VHFFS, and decided to package one or two non-yet-packaged software for Debian. My friends pushed me into the NM process, and less than 2 months later I was a Debian developer. One have to admit that back in the days, the NM process was really fast if you were able to reply to the questions quickly. :-) I think I became the youngest developer among Debian's ones. That was my first steps in a Free Software project, and it was really exciting. In 10 years, I've been doing a lot of different things for Debian. Sure, I've been using it all the years long, but let's recap a bit what I did, from what I recall. My first Debian only project was apt-build around 2003, and later rebuildd in 2007. I built the Xen packaging team in 2005, I've been a Stable Release Manager for a year in 2006, and did heavy bug squashing to release Etch that same year. I also was an Application Manager in 2006 and managed the application of 2 Debian developers (Jose Parrella and Dami n Viano). I admit I've been less active in Debian after 2007, mainly because I was busy working on awesome, GNU Emacs and others software. Since 2011, I joined the OpenStack packaging team and I'm working on OpenStack on a (almost) daily basis. I don't know how many packages I touched, managed or updated, but that should be one or two hundreds. I still maintain 53 of them. After all, the adventure has been really pleasant, and I had the chance to work with and meet fabulous and smart people. I always liked this project and what it's trying to do. After all these years, I'm definitively staying! See you in another 10 years, folks! :)

30 January 2012

Pau Garcia i Quiles: HTML5 for everything?

Apparently HTML5 applications are the best thing after sliced bread. HTML5 is the first platform any mobile vendor supports: iPhone, Android, Windows Phone, BlackBerry, Symbian. All of them. Windows 8 is said to promote HTML5 as the preferred application development solution. I used to look kindly at that. But about a month ago I started to get worried: is HTML5 good for everything? Long-lived applications In military, industrial, warehouse management, medical, etc is not rare that bespoke applications are developed and stay in use for many years (and I really mean many: 10, 20 or even more!) with barely an update. It s not rare that those applications only receive very small updates once very 5 years. Those applications, not Angry Birds, are what keeps the world running: troops know what supplies they can count on, iPhones are manufactured, FedEx is able to deliver your package and your doctor is able to check your health. But now that everybody seems to be moving to HTML5 webapps, what happens when my warehouse management application is a webapp and the additions in the newest browsers make the webapp no longer work? Are vain upgrades the future? Say my webapp is released in 2014 and it works fine with Firefox 14.0 and Chrome 26.0, the newest browsers when I release the application in 2014. Fast-forward to 2020 and Firefox 14.0 and Chrome 26.0 do not even install on Windows 10 computer! What s the solution? Should the customer pay for a huge update and redesign to make it work with Firefox 27.1 and Chrome 41.0 in 2020? A virtual machine with Windows 8 and Firefox 14.0? A portable Mozilla Firefox 14.0 on Windows 10 in 2020 to be able to use that line-of-business application that only requires a small update once or twice every 5 years? How are the virtual machine and/or Portable Firefox 14.0 different from or better than a fat client? What s the advantage? I d say none! Native applications usually do not have that kind of problems because APIs are much more stable. You can still run Win16 applications on Windows 7! You don t believe me? We may soon be developing for 76 browsers! While HTML5 may be fine for applications which are updated very often, it makes me feel very uneasy to see it used in environments where applications will be rarely updated, such as SCADAs, warehouse management, control system, medical records, etc. A solution is needed It looks like that choice of technology is going to make those applications much more expensive in the medium and long term, paying for adaptations to new browsers (sorry, I resist to call update or upgrade to something that adds zero value other than being able to run on a newer browser). Or maybe it s about time to define actual HTML5 profiles . ACID3 seems to be too weak of a profile: two very different browsers may pass ACID3 yet a webapp would work with one browser and fail with the other due to bugs, missing features/added features, etc. Something needs to be done.

2 January 2012

Gunnar Wolf: Happy Public Domain day, even for the inhabitants of the longest-copyright-term country

Happy Public Domain day, even for the inhabitants of the longest-copyright-term country
Every year, on January 1st, new material ceases to be protected by copyright and enters the public domain. This means, every year, more knowledge, literature, paintings, music, movies and a long etcetera becomes collective property, instead of being artificially held by the current holders of their rights. As this image shows (source: http://publicdomainday.org/node/39 ), I have the honor(?) to live in the country with the longest copyright protection term in the world. Copyright in Mexico does not only last for 100 years It lasts for the natural life of the author plus 100 years. This means that the popular corridos that tell the stories of the 1910 revolution are still not in the public domain. La sucesi n presidencial, the book which Francisco I. Madero wrote to justify that a peaceful political change was needed for the 1910 elections, will not enter the public domain until 2014 (president Madero was killed during 1913). Does it make any sense to kidnap cultural, political or artistic works for over a century? Not only that: Material that is legally sold as public domain in other countries is illegal in ours. Take as an example the recordings of Enrico Carusso, the great Italian tenor who died in 1921. Over 15 years ago, I bought a couple of CDs with his recordings (even if the sources were quite low-quality, as they had been copied over from wax cylinders to magnetic tapes to optical media). I bought them surprisingly cheap, as they were genuine public domain. But they are still protected in my country. That means, I ilegally have some stolen(!) works of art which I lawfully bought outside my country. Copyright law needs to be revised to match reality. Technological advances have strongly changed reality since 1717's promulgation of the first copyright laws. The solution is not to extend the terms, but to rethink the whole process. (yes, this rant was mainly made as an excuse for me to copy this image and put it in a location I can easily refer to later. But I hope it is interesting to you!)

7 October 2011

Matthew Garrett: Margaret Dayhoff

It's become kind of a clich for me to claim that the reason I'm happy working on ACPI and UEFI and similarly arcane pieces of convoluted functionality is that no matter how bad things are there's at least some form of documentation and there's a well-understood language at the heart of them. My PhD was in biology, working on fruitflies. They're a poorly documented set of layering violations which only work because of side-effects at the quantum level, and they tend to die at inconvenient times. They're made up of 165 million bases of a byte code language that's almost impossible to bootstrap[1] and which passes through an intermediate representations before it does anything useful[2]. It's an awful field to try to do rigorous work in because your attempts to impose any kind of meaningful order on what you're looking at are pretty much guaranteed to be sufficiently naive that your results bear a resemblance to reality more by accident than design.

The field of bioinformatics is a fairly young one, and because of that it's very easy to be ignorant of its history. Crick and Watson (and those other people) determined the structure of DNA. Sanger worked out how to sequence proteins and nucleic acids. Some other people made all of these things faster and better and now we have huge sequence databases that mean we can get hold of an intractable quantity of data faster than we could ever plausibly need to, and what else is there to know?

Margaret Dayhoff graduated with a PhD in quantum chemistry from Columbia, where she'd performed computational analysis of various molecules to calculate their resonance energies[3]. The next few years involved plenty of worthwhile research that aren't relevant to the story, so we'll (entirely unfairly) skip forward to the early 60s and the problem of turning a set of sequence fragments into a single sequence. Dayhoff worked on a suite of applications called "Comprotein". The original paper can be downloaded here, and it's a charming look back at a rigorous analysis of a problem that anyone in the field would take for granted these days. Modern fragment assembly involves taking millions of DNA sequence reads and assembling them into an entire genome. In 1960, we were still at the point where it was only just getting impractical to do everything by hand.

This single piece of software was arguably the birth of modern bioinformatics, the creation of a computational method for taking sequence data and turning it into something more useful. But Dayhoff didn't stop there. The 60s brought a growing realisation that small sequence differences between the same protein in related species could give insight into their evolutionary past. In 1965 Dayhoff released the first edition of the Atlas of Protein Sequence and Structure, containing all 65 protein sequences that had been determined by then. Around the same time she developed computational methods for analysing the evolutionary relationship of these sequences, helping produce the first computationally generated phylogenetic tree. Her single-letter representation of amino acids was born of necessity[4] but remains the standard for protein sequences. And the atlas of 65 protein sequences developed into the Protein Information Resource, a dial-up database that allowed researchers to download the sequences they were interested in. It's now part of UniProt, the world's largest protein database.

Her contributions to the field were immense. Every aspect of her work on bioinformatics is present in the modern day larger, faster and more capable, but still very much tied to the techniques and concepts she pioneered. And so it still puzzles me that I only heard of her for the first time when I went back to write the introduction to my thesis. She's remembered today in the form of the Margaret Oakley Dayhoff award for women showing high promise in biophysics, having died of a heart attack at only 57.

I don't work on fruitflies any more, and to be honest I'm not terribly upset by that. But it's still somewhat disconcerting that I spent almost 10 years working in a field so defined by one person that I knew so little about. So my contribution to Ada Lovelace day is to highlight a pivotal woman in science who heavily influenced my life without me even knowing.

[1] You think it's difficult bringing up a compiler on a new architecture? Try bringing up a fruitfly from scratch.
[2] Except for the cases where the low-level language itself is functionally significant, and the cases where the intermediate representation is functionally significant.
[3] Something that seems to have involved a lot of putting punch cards through a set of machines, getting new cards out, and repeating. I'm glad I live in the future.
[4] The three-letter representation took up too much space on punch cards

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8 September 2011

Wouter Verhelst: Why I think MySQL is a toy.

A commentor on my previous post asked why I think MySQL is a toy. I've actually blogged about that a number of times, but when wanting to point that out, I found that most of those posts point out just one thing, rather than having one post that enumerates them all. So let's remedy that, shall we? There are many things wrong with MySQL, including, but not limited to: So it's my opinion that any database which fails to store data correctly in its default settings can't be anything but a toy; or that a database which has a comparatively small feature set can't be anything but a toy. But maybe that's just me. [1] No, I haven't used all those features; but I have used asynchronous notification, sequences (other than for primary keys), kerberos auth, custom data types, and (obviously) I have enjoyed the extra peace of mind of knowing that my database is ACID compliant, meaning that it will either accept my transaction as a whole, or reject it as a whole (but usually the former). In addition, I've seen customers use the table inheritance feature.

28 August 2011

Blars Blarson: oogoo-raspberrypi

Oogoo and Raspberry Pi While I haven't been doing much blogable myself, I have recently found a couple of interesting things via Hack A Day: Oogoo is a moldable silicone clay that is easy to make from readily available substances. The main problem for what I'm thinking of using it for is it releases acid as it cures, so I'm not sure using it to encapsulate metal is a good idea. Still, it looks like something fun to work with. Raspberry Pi while not shipping yet (they hope for November/December) looks very interesting -- a $35 (or $25 for the less well configured one) low-power credit-card sized Arm board running Linux with a reasonable amount of I/O (USB, Ethernet, HDMI, I2C, I2S, SPI, serial, audio, composite video, and GPIO). The alpha version is running Debian, but they plan on shipping with Ubuntu or another distro. While the first version is aimed at experimenters (no case, no power supply) they are a UK non-profit aiming at the education market. This is not a direct competitor with the OLPC, which is aimed at younger children.

19 March 2011

Gunnar Wolf: Starting work on KindleClip

Starting work on KindleClip
Quite probably, the best thing got for myself during the last year was my Kindle. I just love it! It has changed the way I interact with knowledge, and saved me from hours of boredom. But it has also taught me the value of scribbling along the book pages and of underlining passages. Yes, I hold a deep regard for my regular (paper) books, and I never scribble on them, not even on text books. In any case, I can scribble on a post-it or something like that. Still, when you underline or comment on a passage in the Kindle, what can you do with your annotation? Well, not much. Annotations (called clippings in Kindlespeak) are stored on an easily accessible My Clippings.txt text file, very easy to parse and work with. So, I devoted yesterday evening to coming up with a first prototype of an app that I think can be very useful if you use clippings extensively: It displays each clipping with its base information separately, allows you to filter on the specific book to which each clipping is related as well as on the clipping type. So, if it interests you, clone it away from github!
git://github.com/gwolf/kindleclip.git
Written in Ruby, Gtk (Glade). No further libraries are (currently?) needed. The code is far from beautiful, but is a first stab towards functionality. Any comments welcome!

23 February 2011

Gunnar Wolf: Finally presented that long-overdue exam!

Finally presented that long-overdue exam!
What Yes, I have not used this kind of outfit for over 20 years. And I hope it will be 20 more years before I do it again. But today, I was seen like this in public. Why? Well, I won't explain the whole background yet again I did it a bit over a month ago in this same space. Much much in short, I never attended university, so after many years of working without any formal validation for my knowledge I followed the CENEVAL Acuerdo 286 procedure to get a "Software Engineering" title and the corresponding c dula profesional. Today I did the last portion of this procedure: Presenting an oral exam, defending the work I developed. Not precisely a thesis, but you can see it as an equivalent. One of the requisites was to go on formal attire Of course, I have some beautiful shirts I am very fond of, but I didn't want to risk it to such a detail, so I asked my friend and almost-neighbour Miguel Barajas to lend me the needed bits of clothing, and presented the exam. Was it easy? No, not by a long shot. Did I pass? Yes! Now, back to work!

10 January 2011

Gunnar Wolf: Tomatoes produced in Mexico

Tomatoes produced in Mexico
So this is that misterious red type of produce known only to a certain US ex-vicepresident? (seen at a Mexico City supermarket. Note that there was no label stating what the misterious thing was in Spanish)

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