Infrasonido

Sonido cuya frecuencia es menor a los 20 Hz.

Algunos de nuestros animales más grandes pueden llegar a detectarlos, como es el caso del elefante, que escucha tonos de hasta 15 Hz.
De la misma forma, las ballenas emiten sonidos de baja frecuencia para comunicarse a distancias de kilómetros. Incluso la propia tierra produce vibraciones de baja frecuencia, como es en el caso de los terremotos. De ahí que algunos animales sean capaces de percibirlos antes de que se produzcan.
No tenemos que confundir escuchar un infrasonido con no sufrir sus consecuencias, ya que no es así. Aparatos como calderas, aviones o automóviles emiten sonidos en este rango de frecuencias, y aunque no afectan a nuestra capacidad auditiva, bien pueden causarnos vértigo, náuseas o dolores de cabeza.
Y si subimos un nivel más, estos sonidos de baja frecuencia pueden causar resonancias en las cavidades corporales, pudiendo lesionar los órganos internos. Es para pensárselo a la hora de ponerse delante de un altavoz en una discoteca…
Pero no tenemos que irnos muy lejos para encontrar infrasonidos. Nuestro propio cuerpo emite en esta frecuencia al hacer cosas tan sencillas como mover un brazo. El músculo, al cambiar de longitud, hace que sus fibras vibren y produzcan este tipo de sonido.
Try: Si queremos comprobarlo, no tenemos más que hacer este sencillo experimento: coloquemos los dedos pulgares sobre nuestros oídos, y cerremos los puños. Conforme vaya apretándose cada mano, iremos oyendo un sonido sordo producido por la contracción de los músculos del antebrazo.

Future Memories

Scientists are discovering that human memory does indeed work forward. A growing number of studies show that the mental machinery for reliving your past performs another-perhaps more vital-task: envisioning your future.
Other studies show that total amnesiacs report a "blank" when asked about their personal futures. And severely depressed patients, who tend to think about both the past and future in a nonspecific manner, have difficulty visualizing positive future events.
Such findings have stimulated scientists to rethink the role of memory. Rather than viewing it as a mere storehouse of facts and autobiographical data, researchers are beginning to recognize that memory also constructs, simulates and predicts possible future events in an ever-changing environment. Perhaps, some say, this kind of autobiographical memory exists precisely for this purpose.
Though current studies focus on episodic memory, or memories of events, times and places, Schacter says that other forms of memory such as semantic memory and generalized knowledge are no doubt also relevant to thinking about the future. "Episodic memory seems to be important when people think about their personal futures because it is the source of the details that allow one to build simulations of what might happen."
For more than a century, scientists studying memory have focused on its role in preserving and recovering the past. Eventually, memory's neurochemical nuances were mapped mainly to the hippocampus and prefrontal cortex.
In the early 1980s, researchers identified additional regions used in planning and foresight. Studies of patients with brain lesions suggested that such patients struggled in these tasks as well as in remembering the past. About that time, psychologist Endel Tulving of the University of Toronto suspected that the mental powers enabling humans to remember episodes from the past, such as a disagreement with a client, also confer the ability to foresee possible futures, as in planning an upcoming meeting with that client.
At the time, only one imaging study had been done to examine the general brain regions common to both thinking ahead and remembering the past. By using a more systematic approach, Schacter reasoned, he might be able to pinpoint the components involved in both activities.
In the early stage of constructing an event, the left hippocampal region appeared equally active in remembering and imagining. The overlap was most apparent at the "elaboration phase," when subjects gave details on the events. In addition, certain regions in the right hippocampus became active when subjects imagined a future event, but not when they remembered a past one. Schacter says these activations may reflect a process of recombining details from various past events into a new imaginary episode.
Despite the recent progress, Maguire says scientists are a long way off from understanding how memory's various brain components talk to each other and interact to simulate future events.

Fuente: http://www.psycport.com/showArticle.cfm?xmlFile=bhsgml_2008_06_28_28496_1501112851-0018-KEYWORD.Missing.xml&provider=Science%20News

Identification of Neural Outgrowth Genes using Genome-Wide RNAi

It's clear that there's a specific set of genes responsible for brain development when you're in the womb, and that those genes affect your ability to learn later on. But now a group of researchers in the U.S. and Canada have identified those genes. And their discovery could represent the first step in tweaking brain development. It's possible that that knocking out some of those genes or adding extra copies of them to a developing baby could result in the tailor-made human minds of Brave New World: Some will be born to develop cutting-edge technologies, and others to be slow-witted and compliant.
Published this weekend in PLoS Genetics, the study is extraordinary not just because of its futuristic implications, but because of the cool new super-rapid system the researchers used to identify which genes are active during brain development. The technique is called RNA interference, or RNAi:
Dr. Katharine Sepp and her fellow researchers took fresh neuronal cells extracted from embryos of the fruit fly genus Drosophila and screened them using RNA interference techniques. The team tested all genes, one by one in a rapid manner, for their potential role in neuronal development. The team then validated the method in mice.
A combination of live-cell imaging and quantitative analysis allowed Sepp et al to characterize neurons’ morphological phenotypes in response to RNAi-mediated gene knockdown. The researchers focused on 104 evolutionary conserved genes that, when downregulated by RNAi, have morphological defects. The team developed algorithms to help streamline the analysis of the thousands of images created in the process.
The analysis revealed unexpected, essential roles in neurite outgrowth for genes representing a wide range of functional categories including signalling molecules, enzymes, channels, receptors, and cytoskeletal proteins. Results also determined that genes known to be involved in protein and vesicle trafficking show similar RNAi phenotypes.
The researchers believe that this study provides an effective method for future studies of a large variety of genes, including those with important functions in the nervous system.

Fuente:http://www.plosgenetics.org/article/fetchArticle.action?articleURI=info:doi/10.1371/journal.pgen.1000111

20 Reasons not to move to Dubai

1. There is no standard address system making mail-to-the door delivery impossible. In fact, it makes anything nearly impossible. The taxi driver, here for only two days, and having learned English from old Beatles albums has no clue where your house is. He won’t tell you that of course, he’ll just keep calling and saying, “Okay, okay. Yeah, yeah.”
2. The government blocks all web sites that it deems “offensive” to the “religious, moral, and cultural values” of the UAE. All VOIP access and related web sites are blocked.
3. It is really hot outside. Not Florida in July hot; Hot as if you were locked in a car in Florida in July with sufficient humidity to make it feel as though you are drowning.
4. There are too few trees, plants, and grass – or living things aside from us crazy humans, for that matter. Ever see a bird pant? I have. In my opinion, human beings were not meant to live in such a place. If we were, there would be sufficient water and shade. The only greenery around are the roadside gardens planted by the government, who waters the hell out of them in the middle of the day. Thanks a lot!
5. This country prides itself so much on its glitz and glamour that it put a picture of its 7-star hotel on the license plate. Yet, the public toilets in the king-of-bling Gold Souk district are holes in the ground with no toilet paper or soap. Hoses to rinse your nether regions, however, are provided.
6. This country encourages businesses to hire people from other poor countries to come here and work. They have them sign contracts that are a decade long and then take their passports. Even though taking passports is supposedly illegal, the government knows it happens and does nothing to enforce the law. These poor people are promised a certain pay, but the companies neglect to tell them they will be deducting their cost of living from their paychecks, leaving them virtually penniless – that is, if they choose to pay them. Companies hold back paychecks for months at a time. When the workers strike as a result, they are jailed. Protesting is illegal, you see (apparently this law IS enforced).
7. Things are not cheaper here.
8. There are traffic cameras everywhere. I consider this cheating. Where are the damn cops? I drove around this city for weeks before I ever even saw a cop. Trust me, they need traffic cops here. People drive like idiots. These cameras are placed strategically as you come down hills, or just as the speed limit changes.
9. The clothing some of these women wear makes no sense to me. I understand that as part of your religion you are required to dress in a particular way, but a black robe over your jeans and turtleneck and cover your head when it is 120 degrees outside? In the gym some women wear five layers of clothing…sweatpants and t-shits over sweaters with headscarves. Yet the men’s clothing makes absolute sense: white, airy, and nothing underneath but their skivvies.
10. People stare at you. I am sick of being stared at. I’m stared at by men who have never seen a fair-skinned blue-eyed woman before, or who have and think we are all prostitutes so it’s okay to stare. They stare at me when I am fully covered or with my husband, and even follow me around. It’s beyond creepy and has brought me to tears on more than one occasion.
11. Prostitutes? Oh hell yes, there are prostitutes. Tons of them.
12. Alcohol can only be sold in hotels and a handful of private clubs. A person must own a liquor license to consume in the privacy of their own home. To obtain a liquor license you must get signed approval from your boss, prove a certain level of salary that determines how much you are allowed to buy, and then submit several mug shots (aka passport photos) for approval. Pay the fee and the additional 30% tax on every purchase and you may drink at home. Then again, you can just pick up a few bottles in the airport duty free on your way in to the country, but two is the max.
13. Not only do you have to get your boss’s approval to obtain a liquor license, but you must also get the company’s approval to rent property, have a telephone, or get satellite TV.
14. Back to the craziness on the roads: If I see one more kid standing up and waving to me out the back window while flying down the road at 160 kph…whatever happened to seatbelts?
15. When is the weekend again? Let me get this straight: the weekend used to be Thursday and Friday, but no one took off all of Thursday, just a half day really. Now the government says Friday and Saturday are the weekend, but some people only take off Friday, others still take a half day on Thursday, but some might just take a half day on Saturday instead.
16. There are few satellite television operators: The movie channels play movies that are old and outdated. Many of them went straight to video back in the States. Every sitcom that failed in the US has been purchased and is played here. Old episodes of Knight Rider are advertised like it is the coolest thing since sliced bread. The TV commercials are repeated so often that I am determined NOT to buy anything I see advertised on television here just for thee principle of it. When I say repeated often, I mean every commercial break - sometimes more than once.
17. The roads are horribly designed. Driving ten minutes out of the way to make a U-turn is not uncommon. People are not able to give directions most of the time (remember reason #1), and the maps are little help because most have few road names on them, if any.
18. Taxi drivers are dangerous and smell. Taxi drivers work very hard here to earn a living because travel by taxi is still relatively inexpensive, even though the cost of living is not (see reason #7). Because of this you may have a driver who has had little sleep or the opportunity to shower for several days.
19. Speeding is an Emirati sport and Emirates Road is just an extension of the Dubai Autodrome. I know I keep mentioning the roads, but really, much of this city’s issues are encompassed by the erratic and irrational behavior displayed on its streets. Local nationals are somehow able to get the sun-protecting dark window tint denied to us lowly expats and use it to hide their faces as they tailgate you incessantly at unbelievably high speeds, their lights flickering on and off and horn blaring repeatedly. It doesn’t matter that you can’t get over, or if doing so would be particularly dangerous, they will run you off the road to get in front of you. Don’t even think about giving someone the finger; the offense could land you in jail. Tailgating is, unbelievably, legal.
20. Dubai is far from environmentally friendly. Ever wonder how much damage those manmade islands are doing to the delicate ocean ecosystem? Coral reefs, sea grasses, and oyster beds that were once part of protected marine lands lie choked under a barrage of dredged up sea sand. Consider the waste that occurs from erecting buildings on top of these sand monsters and from the people that occupy them coupled with the lack of an effective recycling program and you have an environmental disaster on your hands.

Fuente: http://www.escapeartist.com/efam/94/art_20_Reasons_Not_Move_to_Dubai.html

Vivienda para tifones

• La construcción se comenzó en el año 1992 y está compuesta por grandes silos que tienen 65 metros de altura y 32 de anchura. Estos túneles tienen 6.5 kilómetros y están construidos 50 metros por debajo de la superficie. Además tiene un tanque gigante que mide 25.4 metros de alto, 177 metros de largo y 78 de ancho con 59 columnas de concreto. Lo que están viendo en la fotografía es nada menos que el sistema de colectores de aguas lluvias de la ciudad de Saitama, en Japón, que no permite que la ciudad se inunde en caso de tifones.

• Fuente: http://alt1040.com/2008/07/increible-construccion-japonesa-para-soportar-tifones/

Mensaje Encriptado

• Según leo en NewTeeVee, “The Pirate Bay wants to encrypt the entire Internet“, la propuesta de The Pirate Bay consiste en una tecnología, Transparent end-to-end encryption for the internets, abreviada como IPETEE, cuyo desarrollo preliminar aparece recogido en este wiki, que traspasaría la encriptación desde el nivel de la aplicación hasta el nivel de la red, lo que haría que todas las transmisiones que salen de tu ordenador estuviesen encriptadas, independientemente de su naturaleza o de la aplicación que las originó. Uno de los cofundadores de The Pirate Bay, Fredrik Neij, conocido como Tiamo, tuvo la idea a mediados de 2007, cuando algunos políticos europeos iniciaron el debate acerca de la eliminación de derechos fundamentales en Internet para favorecer a los lobbies de la propiedad intelectual, y ha considerado oportuno ahora, al recrudecerse la ofensiva liberticida. La idea sería instalar IPETEE como un add-on sobre el sistema operativo, que se encargaría de realizar las tareas de encriptación de todo el tráfico IP sin que el usuario tuviese que llevar a cabo ninguna tarea: en cada conexión, IPETEE comprobaría si el servidor remoto posee soporte para la tecnología de encriptación, y en caso positivo, intercambiaría las claves para proceder al envío de la información, que se desencriptaría de manera automática al alcanzar el ordenador de destino. En el caso de que el servidor no soportase la tecnología de encriptación, la conexión pasaría a desarrollarse en modo abierto.
• Fuente: http://feeds.feedburner.com/~r/ElBlogDeEnriqueDans/~3/331580781/contra-los-vigilantes-encriptemos-internet.html

¿Cómo cazan los programadores a los elefantes?

• Programador dBase: Solo cazan de noche para que nadie los vea que todavía utilizan garrotes para cazar.
  
• Programador C: No compran Rifles, prefieren llevar acero y un torno a África para construir el mejor rifle desde el diseño, mientras los demás se acaban los elefantes.
  
• Programador FOXPRO: Toman los rifles que desechan los programadores C, lo que ocasiona que se les vaya el tiempo en aprender nuevas técnicas de tiro en vez de cazar elefantes.
  
• Programador Clipper: Ellos no cazan elefantes, se la pasan comprando librería tras librería de partes de elefantes y se pasan años intentando integrar uno completo mientras resuelven los errores que van apareciendo.
  
• Programador RPG: Son mas difíciles de encontrar que los elefantes. De hecho, cuando un elefante ve a un programador RPG piensa que es su día de suerte.
  
• Programadores ADA, FORTRAN, PROLOG: Son personajes ficticios como Santa Claus y los elefantes rosas.
  
• Programador COBOL: No les interesa mucho el ir a cazar a otra especie en extinción como ellos, en realidad prefieren la vida de oficina.
  
• Programador VISUAL BASIC: Con el mouse dan doble-click en los rifles, dan doble-click en las balas, dan doble-click en el elefante. Esto realmente divierte tanto al elefante que lo hace revolcarse de risa por el suelo y aplasta el mouse. Mientras, el programador VISUAL BASIC se queda mirando como el elefante se aleja tranquilamente.
  
• Programador Assembler: No los cazan, crean sus propios elefantes, mas rápidos y pequeños.
  
• Programador C++ / Java: Toman un elefante abstracto y derivan de el un nuevo elefante (ej.MiElefante) con todas las propiedades que necesitan. Para cazar uno simplemente, una instancia class Cazador, llama al método CazarElefante el cual la envía el mensaje CAZAR a la class Elefante que lo entiende con un método virtual puro, cuya implementacion esta definida en la nueva clase derivada MiElefante. Esta implementación llama al método setEstoyCazado() que pone el atributo bEstoyCazado =TRUE, con lo que el elefante se da por enterado que ha sido cazado. La class MiElefante esta disponible para ser rehusada/extendida por otro proyecto, ventajas de la OOP.
  
• Programador de 4GLs: En el servidor establecen que: if (select count(*) from animal where nariz = 'larga' and orejas = 'Grande' and color = 'gris' and nombre not like 'ratón') > 0 then execute procedure Mata_elefante(animal.animal_id); else execute procedure Crea_animal('Elefante', 'larga','grande','gris'); execute procedure Mata_elefante(animal.animal_id); end if; Luego tienes que crear una pantalla en el cliente, para ver la foto del elefante, y ponerle el boton de "disparar" que simplemente ejecuta lo anterior...
• 
  Fuente: http://www.mail-archive.com/rivendel@firebirds.com.ar/msg00085.html