Tag Archives: research

Papel da fofoca em nossa evolução

Standard

How to Read a Scientific Paper

Standard
How to Read a Scientific Paper

When reading a Science Paper, we have to focus on identifying some basic informations. Therefore, we have to first understand how to identify each of them:

Background: Every paper presents the scenario in the previous literature that left a door open, leading to the present study. Usually, the authors start talking about it in order to address their own question.

Question: What is the question that authors designed the study to answer? Usually, it is presented right after presenting the previous literature.

Logic: What is the rationale of the experiment? In other words, why does it make sense to do the experiment in the way it was done?

Method: First thing to do is to identify the name of the Method. If you don’t know anything about the Method, you should google it before reading more about the Method… and identify:

  • Stimulus: what was presented to the subject
  • Task: what was the subject asked to do
  • Independent variable (IV): the variable that affects the DV (*)
  • Dependent variable (DV): the variable being measured; what is varying in the experiment that is affected by IV or correlated to the IV(*).

It is worth noting that most of the time the IV and DV are included in the paper title.

Results: What are the results of the experiment? Usually, they present many results but always emphasizing the result that is the most important. The results are very specific, and most of the times expressed in numbers, percentages, and statistical results. If you don’t know how to interpret them, skip to the conclusion… but keep in mind that is necessary to understand statistics in order to evaluate the liability of the paper.

Conclusion: How do the authors interpret the results?  What conclusion do they make from them?

(*) More about IV and DV: http://nces.ed.gov/nceskids/help/user_guide/graph/variables.asp

Vision with Cell Transplant in the Retina [Visão com Transplante de Célula na Retina]

Standard

It was published in Nature April 18 2012, a study that suggests that transplanting photoreceptors – nerve cells that line the back of the eye sensitive to light – could form the basis of a new treatment to restore sight in people with retinal degenerative diseases. Loss of photoreceptors is the cause of blindness in many human eye diseases including age-related macular degeneration and retinitis pigmentosa.

Scientists injected cells from young healthy mice directly into the retinas of adult mice that lacked function for this type of photoreceptors. After 6 weeks, the transplanted cells appeared to be functioning almost as well as normal cells and had formed the connections needed to transmit information to the brain. For the first time, transplanted photoreceptor cells were integrate successfully with the existing retinal circuitry and truly improve vision. The group is hopeful that soon they will be able to replicate this success with photoreceptors derived from embryonic stem cells and eventually to develop human trials. The findings also pave the way for techniques to repair the central nervous system as it demonstrates the brain’s amazing ability to connect with newly transplanted neurons.

Nature, April 18 2012, Pearson et. al.: Restoration of vision after transplantation of photoreceptors

Example of Retinitis Pigmentosa

Example of Retinitis Pigmentosa

[Foi publicado em 18 de abril de 2012, na Nature, um estudo que sugere que o transplante de fotorreceptores – células nervosas no fundo do olho sensíveis à luz – poderia formar a base de um novo tratamento para restaurar a visão em pessoas com doenças degenerativas da retina. A perda de fotorreceptores é a causa de cegueira em muitas doenças do olho humano, incluindo a degeneração macular e a retinose pigmentar.

Os cientistas injetaram células de jovens ratos saudáveis diretamente nas retinas de ratos adultos que não tinham função para este tipo de fotorreceptores. Após 6 semanas, as células transplantadas pareceram estar funcionando quase tão bem como as células normais e tinham formado as ligações necessárias para transmitir informação para o cérebro. Pela primeira vez, as células fotorreceptoras transplantadas foram integradas com sucesso ao circuito existente na retina e melhoraram a visão. O grupo está esperançoso de que em breve eles serão capazes de replicar esse sucesso com fotorreceptores derivados de células-tronco embrionárias e, eventualmente, desenvolver testes em humanos. Os resultados também abrem o caminho para técnicas de reparação do sistema nervoso central que vem demonstrando a incrível habilidade do cérebro para se conectar com neurônios recém-transplantados.]