sexta-feira, 4 de dezembro de 2015

Avaliação do Professor pelo aluno 2015

Clique aqui para a avaliação do professor Cláudio Patto pelo aluno.

2A
2B
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3B

Obs: estes links só ficam ativos durante a aula de avaliação.

domingo, 15 de novembro de 2015

Why 37oC?

Most "warm blooded" animals maintain their internal body temperature in a specific temperature ranging from 35 to 40oC. Humans keep it at 37. Camels and elephants at 36. Cows and cats at 38. Rabbits at 39 and Chickens at almost 42.

This heating is performed at the expense of much energy. For example, when air temperature is around 20oC, mammals spend 30 times more energy than reptiles to support their metabolic rate.

There are many reasons for maintaining the body temperature constant and elevated (Life Ascending - chapter 8), but why not having a wide range of bodies temperatures? For example, to live in a temperate condition of around 20oC, keeping the body at 20-25 would be very appropriate and economic. In the tropics conditions of around 30oC, 30-35 sounds good. 

But why 35-40? Why 37? The answer may be in the water specific heat. To
Change the the temperature of 1g of water 1oC, from 15oC to 16oC, it is necessary 1 calorie (4.2 joules). But why from 15 to 16? Because this amount of energy varies according to the temperature. From 16 to 17 it is necessary less than 1 calorie and this amount reduces until 35oC. From 35 on the amount of energy required restarts increasing. This means that, around 35oC, the amount of energy to heat up the body (mostly water) is smaller than at any other temperature. This may be a small amount, but adding all the little bits in a life time may pay off (Survival of the Fittest)

sábado, 16 de agosto de 2014

Biology Handbook for the IB Diploma at ESBSP 2016

The handbook as ePub, good for iBooks and other ebook readers is available in the link bellow. Shall you don't have an ebook reader device and want the file in PDF, you may download it here as well:

Biology Handbook IB Diploma at ESBSP - ePub and iBooks
Biology Handbook IB Diploma at ESBSP - pdf

Biology EE Handbook IB Diploma at ESBSP Up to 2017 - pdf
Biology EE Handbook IB Diploma at ESBSP 2018 provisional - ePub and iBooks
Biology EE Handbook IB Diploma at ESBSP 2018 provisional - pdf

In the google drive, there is no need to navigate the files. Just ask to download in the top of the window button.

sexta-feira, 18 de janeiro de 2013

Árvore Genealógica dos Mamíferos

Esta é a mais completa árvore genealógica (cladograma) para mamíferos que eu conheço. É circular, para caber em um espaço menor, mas mesmo assim é gigantesca.

Pode ser visto em PDF e é fantástico. Tem uma seta para indicar onde estamos (Homo sapiens), ao lado dos Pan paniscus e Pan troglodites, as duas espécies de chipanzés, primatas mais próximos a nós nesta árvore.
Abra o PDF para a árvore aqui.


Atenção do Mosquito

Pesquisadores da Universidade Yale identificaram a proteína usada pelo mosquito da malária para perceber suas vítimas. Malária afeta centenas de milhares de pessoas pelo mundo, ocorre em áreas que contém metade da população do planeta e causa ao redor de um milhão de mortes ao ano.

Uma das substâncias encontradas que teria um grande impacto no inseto é o indol, que ocorre naturalmente no sangue humano. Isto pode explicar porque algumas pessoas são muito mais atrativas. Para os mosquitos, algumas pessoas cheiram bem e outras não.

Este achado é muito excitante já que pode levar a melhores repelentes ou armadílhas para os insetos.

CDC
Anopheles

Mosquitoes attraction

Researchers from Yale University have identified the proteins used by the malaria mosquito to sense their victims. Malaria affects hundreds of thousands f people around the world, occurs in areas that fits half the planet’s population and causes around a million deaths every year.
One of the substances found to have great impact on the insects is the indol, which occurs naturally in human blood. This may explain why some people seems to be much more attractive. For the mosquitoes, some people smell good and some doesn’t.
This finding is exciting, as it may lead to better insect repellent or insect traps.

CDC
Anopheles