Wednesday, September 12, 2012

BIg Chem; Big Harm? (NYT)

Son, this is one reason I have worked so hard to find a place to shop that doesn't have ANY harmful chemicals in their products.  You know my favorite store.  You may also want to click here after reading this article. ;-) This is an important science lesson.The assignment details follow the article.

BIG CHEM; BIG HARM?
by Nicolas Kristof
                                                                  edited by Mom

NEW research is demonstrating that some common chemicals all around us may be even more harmful than previously thought. It seems that they may damage us in ways that are transmitted generation after generation, imperiling not only us but also our descendants.

Yet following the script of Big Tobacco a generation ago, Big Chem has, so far, blocked any serious regulation of these endocrine disruptors, so called because they play havoc with hormones in the body’s endocrine system
One of the most common and alarming is bisphenol-A, better known as BPA. The failure to regulate it means that it is unavoidable. BPA is found in everything from plastics to canned food to A.T.M. receipts. More than 90 percent of Americans have it in their urine

Even before the latest research showing multigeneration effects, studies had linked BPA to breast cancer and diabetes, as well as to hyperactivity, aggression and depression in children.
Maybe it seems surprising to read a newspaper column about chemical safety because this isn’t an issue in the presidential campaign or even firmly on the national agenda. It’s not the kind of thing that we in the news media cover much. 
Yet the evidence is growing that these are significant threats of a kind that Washington continually fails to protect Americans from. The challenge is that they involve complex science and considerable uncertainty, and the chemical companies — like the tobacco companies before them — create financial incentives to encourage politicians to sit on the fence. So nothing happens. 
Yet although industry has, so far, been able to block broad national curbs on BPA, new findings on transgenerational effects may finally put a dent in Big Chem’s lobbying efforts. 
One good sign: In late July, a Senate committee, for the first, time passed the Safe Chemicals Act, landmark legislation sponsored by Senator Frank Lautenberg, a New Jersey Democrat, that would begin to regulate the safety of chemicals. 
Evidence of transgenerational effects of endocrine disruptors has been growing for a half-dozen years, but it mostly involved higher doses than humans would typically encounter.
Now Endocrinology, a peer-reviewed journal, has published a study measuring the impact of low doses of BPA. The study is devastating for the chemical industry.

THE EXPERIMENT:
Pregnant mice were exposed to BPA at dosages analogous to those humans typically receive. 
WHAT HAPPENED:
1) The offspring were less sociable than control mice (using metrics often used to assess an aspect of autism in humans), and various effects were also evident for the next three generations of mice. 
WHY?
The BPA seemed to interfere with the way the animals processed hormones like oxytocin and vasopressin, which affect trust and warm feelings. And while mice are not humans, research on mouse behavior is a standard way to evaluate new drugs or to measure the impact of chemicals. 
CLARIFICATION & COMMENTS by authors of the report
“It’s scary,” said Jennifer T. Wolstenholme, a postdoctoral fellow at the University of Virginia and the lead author of the report. She said that the researchers found behaviors in BPA-exposed mice and their descendants that may parallel autism spectrum disorder or attention deficit disorder in humans. 
Emilie Rissman, a co-author who is professor of biochemistry and molecular genetics at University of Virginia Medical School, noted that BPA doesn’t cause mutations in DNA. Rather, the impact is epigenetic — one of the hot concepts in biology these days — meaning that changes are transmitted not in DNA but by affecting the way genes are turned on and off.  These results at low doses add profoundly to concerns about endocrine disruptors,” said John Peterson Myers, chief scientist at Environmental Health Sciences. “It’s going to be harder than just eliminating exposure to one generation.” 
SCIENCE HISTORY NOTE:  In effect, this (epigenetic impact) is a bit like evolution through transmission of acquired characteristics — the theory of Jean-Baptiste Lamarck, the 19th-century scientist whom high school science classes make fun of as a foil to Charles Darwin. In epigenetics, Lamarck lives. 
The National Institutes of Health is concerned enough that it expects to make transgenerational impacts of endocrine disruptors a priority for research funding, according to a spokeswoman, Robin Mackar.

In his conclusion, the author of this New York Times Article offers his two cents:
Like a lot of Americans, I used to be skeptical of risks from chemicals like endocrine disruptors that are all around us. What could be safer than canned food? I figured that opposition came from tree-hugging Luddites prone to conspiracy theories.
Yet, a few years ago, I began to read the peer-reviewed journal articles, and it became obvious that the opposition to endocrine disruptors is led by toxicologists, endocrinologists, urologists and pediatricians. These are serious scientists, yet they don’t often have the ear of politicians or journalists.
I’m hoping these new studies can help vault the issue onto the national stage. Threats to us need to be addressed, even if they come not from Iranian nuclear weapons, but from things as banal as canned soup and A.T.M. receipts.
ORIGINAL SOURCE:
New York Times Article - Big Chem; Big Harm?
by
Published: August 25, 2012


ASSIGNMENT:  
1) Read this New York Times article. Read a second time and take key word notes
I have edited with notes in red to keep you focused on important points.
2) VOCABULARY: Define and memorize the 20 bolded words or terms.  You already know many of the words and numerous other words can defined contextually.
3) Make sure you understand and memorize the 2 bolded sentences.
4) Become familiar enough with the article that you are ready to discuss it.
5)  Complete a re-write in your own words by Monday.
5) We can discuss this after dinner tonight.  :-)


Also see: http://kristof.blogs.nytimes.com/
 

Monday, September 10, 2012

Scientific Method

Key Info

  • The scientific method is a way to ask and answer scientific questions by making observations and doing experiments.
  • The steps of the scientific method are to:
    • Ask a Question
    • Do Background Research
    • Construct a Hypothesis
    • Test Your Hypothesis by Doing an Experiment
    • Analyze Your Data and Draw a Conclusion
    • Communicate Your Results
  • It is important for your experiment to be a fair test. A "fair test" occurs when you change only one factor (variable) and keep all other conditions the same.
  • While scientists study how nature works, engineers create new things, such as products, websites, environments, and experiences.

    Overview of the Scientific Method

    The scientific method is a process for experimentation that is used to explore observations and answer questions. Scientists use the scientific method to search for cause and effect relationships in nature. In other words, they design an experiment so that changes to one item cause something else to vary in a predictable way.
    Just as it does for a professional scientist, the scientific method will help you to focus your science fair project question, construct a hypothesis, design, execute, and evaluate your experiment.
    Overview of the Scientific Method


    Steps of the Scientific Method Detailed Help for Each Step
    Ask a Question: The scientific method starts when you ask a question about something that you observe: How, What, When, Who, Which, Why, or Where?
    And, in order for the scientific method to answer the question it must be about something that you can measure, preferably with a number.
    Your Question
    Do Background Research: Rather than starting from scratch in putting together a plan for answering your question, you want to be a savvy scientist using library and Internet research to help you find the best way to do things and insure that you don't repeat mistakes from the past. Background Research Plan
    Finding Information
    Bibliography
    Research Paper

    Construct a Hypothesis: A hypothesis is an educated guess about how things work:
    "If _____[I do this] _____, then _____[this]_____ will happen." You must state your hypothesis in a way that you can easily measure, and of course, your hypothesis should be constructed in a way to help you answer your original question.
    Variables
    Variables for Beginners
    Hypothesis

    Test Your Hypothesis by Doing an Experiment: Your experiment tests whether your hypothesis is true or false. It is important for your experiment to be a fair test. You conduct a fair test by making sure that you change only one factor at a time while keeping all other conditions the same. You should also repeat your experiments several times to make sure that the first results weren't just an accident.
    Experimental Procedure
    Materials List
    Conducting an Experiment

    Analyze Your Data and Draw a Conclusion: Once your experiment is complete, you collect your measurements and analyze them to see if your hypothesis is true or false. Scientists often find that their hypothesis was false, and in such cases they will construct a new hypothesis starting the entire process of the scientific method over again. Even if they find that their hypothesis was true, they may want to test it again in a new way.
    Data Analysis & Graphs
    Conclusions

    Communicate Your Results: To complete your science fair project you will communicate your results to others in a final report and/or a display board. Professional scientists do almost exactly the same thing by publishing their final report in a scientific journal or by presenting their results on a poster at a scientific meeting. Final Report
    Abstract
    Display Board
    Science Fair Judging

    Even though we show the scientific method as a series of steps, keep in mind that new information or thinking might cause a scientist to back up and repeat steps at any point during the process. A process like the scientific method that involves such backing up and repeating is called an iterative process.
    Throughout the process of doing your science fair project, you should keep a journal containing all of your important ideas and information. This journal is called a laboratory notebook.

    LINKS:  Steps of the Scientific Method


Wednesday, September 5, 2012

Franklin Bell & Leyden Jar

Franklin bells are an early demonstration of electric charge designed to work with a *Leyden jar. They were invented by Benjamin Franklin in the 18th century during his experimentation with electricity. Franklin bells are only a qualitative indicator of electric charge and were used for simple demonstrations rather than research.

The bells consist of a metal stand with a crossbar, from which hang three bells. The outer two bells hang from conductive metal chains, while the central bell hangs from a nonconductive thread. In the spaces between these bells hang two metal clappers, small pendulums, which hang from nonconductive threads. A short metal chain hangs from the central bell.

The central bell's chain is put in contact with the inner surface of a * Leyden jar, while the outside surface of the jar is put in contact with the metal stand. The central bell takes its charge from the inner surface of the jar, while the outer surface charges the two bells on the conductive chains; this causes the bells to have a potential difference equal to that between the inner and outer surfaces of the jar. The hanging metal clappers will be attracted to one bell, will touch it, pick up its charge, and be repelled; they will then swing across to the other bell, and do the same there. Each time the clappers touch a bell, charge is transferred between the inner and outer surfaces of the *Leyden jar. When the jar is completely discharged, the bells will stop ringing.


Electric Fly Swatter + Coke Can = Franklin's Bell 
http://www.youtube.com/watch?v=jIL0ze6_GIY&feature=related 


What is a Leyden Jar?

A Leyden jar, or Leiden jar, is a device that "stores" static electricity between two electrodes on the inside and outside of a glass jar. It was the original form of the capacitor.

It was invented independently by German cleric Ewald Georg von Kleist on 11 October 1745 and by Dutch scientist Pieter van Musschenbroek of Leiden (Leyden) in 1745–1746.[1] The invention was named for this city.

The Leyden jar was used to conduct many early experiments in electricity, and its discovery was of fundamental importance in the study of electricity. Previously, researchers had to resort to insulated conductors of large dimensions to store a charge. The Leyden jar provided a much more compact alternative.