Author Archives: laylav

The Terrifying Facts about Hurricanes

Posted on October 30, 2012 | 4 comments

Image of a news advisory for a hurricane

We have all seen images on the news depicting the devastating impact a Hurricane can have, Irene, Katrina and most recently hurricane Sandy.   Hurricane Sandy has been described as a “super storm” causing nearly 90 deaths, leaving more than 8.2 million households without power in 17 states and causing more than $20 billion in damages.  Hurricane Sandy began in the Atlantic then hit the Caribbean and subsequently made its way up the southeastern coast of the United States.  With all the attention on the destructive effects a hurricane can have, do we really know what a hurricane is and how it occurs?

What is a hurricane?

A hurricane is a powerful, rotating weather system that forms and intensifies over tropical oceanic regions.  Although they are most commonly referred to as hurricanes their technical name is tropical cyclone; tropical cyclones that form over the Atlantic Ocean or eastern Pacific Ocean are called hurricanes.  These storm systems are characterized by having a low pressure center and surrounding thunderstorms that create strong winds and heavy rains.  A unique characteristic of tropical cyclones that distinguish them from other cyclonic systems is that the center or “eye of the storm” remains warmer than its surroundings regardless of height in the atmosphere.

Hurricane Sandy is seen on the East Coast of the United States in this NASA satellite image taken at 3:55 a.m. ET Tuesday

How do hurricanes occur?

Hurricanes occur only over warm ocean waters because they use warm, moist air to increase its energy.   When the layer of warm, moist air above the ocean’s surface rises this creates an area of lower pressure below it.  The surrounding higher pressure air begins to move into this lower pressure region and as it does it begins to warm and it too rises.  As this air rises more high pressure air moves in to replace it.  The moist, warmed air is cooled as it rises and as this occurs the water in the air forms clouds.  This process is repeated continuously until an entire system of clouds and cyclonic winds is created.

Anatomy of a Hurricane

What are the effects of a hurricane?

With the heavy winds and rains associated with hurricanes, there are several devastating consequences of a hurricane.  As the hurricane approaches the coastline the extremely forceful winds push water towards the coast creating what is better known as a storm surge.  This abnormal rise of water is able to infiltrate inland causing flooding and destruction due to its force along its path.   Another source of flooding during a hurricane comes from the heavy rainfall.  Anywhere from 15-24cm of rain can fall in a very short time.  Arguably the source of the most damage caused by hurricanes comes as a result of the high and powerful winds.  The shear forces involved in these winds can alone cause damage to homes, street lights, roads, vehicles, trees and power lines.  The most damaging effect of these high winds comes from falling trees and power lines.  As trees and power lines are knocked down, they may land in any direction, causing harm to property, a loss of power or even worse, causing a loss of life.  In the case of hurricane Sandy, 18 people were killed in New York City, including 2 drowning deaths, 1 death caused by a fallen tree and 1 death caused by a live electrical wire landing in a puddle. 

To  see the latest update on the damage caused by Hurricane Sandy watch here. YouTube Preview Image

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Posted in Science Communication, Science in the News

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Why are some sounds so displeasing to hear?

Posted on October 15, 2012 | 4 comments

New study ranks nails run along a chalkboard as one of the most unpleasant sounds to the human ear.

The Amygdala- Active in processing negative emotions

Why is it that certain sounds are so displeasing to the human ear?  For example, the sound of nails running along a chalkboard is synonymous with shivers down the spine.  A new paper published in The Journal of Neuroscience examines the interaction between the emotional and auditory parts of your brain while hearing a variety of sounds.  Scientists at Newcastle University have found that while hearing some sounds, a heightened activity and interaction occurs between the Amygdala part of the brain, which is active in processing negative emotions, and the auditory parts of the brain.  Researchers believe this interaction could explain why some sounds are perceived as unpleasant.

Researchers at the Wellcome Trust Centre for Neuroimaging and Newcastle University used functional magnetic resonance imaging (fMRI) to examine how the brains of sixteen volunteers responded to a variety of sounds.  The sixteen participants (seven females) ranged in age from 22-35 years old and had no prior history of neurological or psychiatric disorders.  The participants were asked to listen to 74 different sounds while in the scanner.  The participants then ranked each sound they heard on a scale from 1 (least unpleasant) to 5 (highly unpleasant).  Here is an example of how some sounds stacked up.

Most Unpleasant Sounds

  • Knife on bottle
  • Fork on glass
  • Chalk on blackboard
  • Ruler on bottle
  • Nails on chalkboard

Least Unpleasant Sounds

  • Applause
  • Baby laughing
  • Thunder
  • Water flowing

Spectrotemporal Representations

Researchers then studied the relationship between the rankings of unpleasantness and the spectrotemporal features obtained from imaging from the fMRI.  Analysis of both the rankings of unpleasantness and the acoustic features of the sounds themselves, found that any sounds within the frequency range of 2,000 to 5,000 Hz were found to be perceived as unpleasant.  The figure to the left shows examples of the spectrotemporal representations for six sounds (the mean unpleasantness is featured in the top right corner of each plot).  These images suggest that sounds with high spectral frequencies and low temporal modulation frequencies are correlated to sounds ranked with high unpleasantness.  It was found that activity in both the auditory complex and the Amygdala were directly proportional to the ratings of perceived unpleasantness.  From this study, it was concluded that the Amygdala is in charge and regulates the activity of the auditory part of the brain, therefore provoking a negative response to some sounds.

Want to see if you agree that the sound of nails running along a chalkboard is highly unpleasant? Take a listen.

YouTube Preview Image

 

 

To read the full journal article click here

 

This blog was written by Layla Vera


 

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Posted in Biological Sciences, Science in the News, Uncategorized

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Could coconut oil be the solution to creating an all natural toothpaste?

Posted on September 16, 2012 | 4 comments

Image source: http://www.cbc.ca/news/technology/story/2012/09/03/sci-coconut-oil-tooth-decay.html

Oral hygiene affects everyone and with the increasing number of children and adults affected by dental caries, more commonly known as tooth decay, has some dentists suggesting we are undergoing an epidemic.  Tooth decay is caused by specific bacteria that erode the hard tissues of the teeth through the production of acid by hydrolysis of food debris.  When left untreated, this infection can spread and possibly lead to serious health complications such as Ludwig’s Angina.

Research done at the Athlone Institute of Technology’s Bioscience Research Institute in Ireland, suggests that coconut oil inhibits the growth of tooth decay causing bacteria and is comparable to the current toothpastes being used.  The research team led by Dr. Damien Brady tested the antibacterial action of coconut oil in both its natural state and when treated with enzymes.  Testing was performed on various strains of Streptococcus bacteria, the most commonly found bacteria in the mouth.  Dr. Brady and his team of researchers found that the enzyme-modified coconut oil substantially inhibited the growth of several strains of Streptococcus.  One of the acid producing, decay causing bacterium, Streptococcus mutans, was found to be strongly inhibited by the modified oil.  An earlier study demonstrating the effects of enzyme-modified milk and its reduction on the binding of Streptococcus mutans to tooth enamel encouraged Dr. Brady’s study on coconut oil.

Dental Caries
http://en.wikipedia.org/wiki/Dental_caries

 

Dr. Brady’s team presented their work at the Society for General Microbiology’s autumn conference at the University of Warwick on September 3, 2012.  Further work will be done on the molecular level interaction between coconut oil and Streptococcus bacteria.  The team will also be testing the modified-oil’s effect against yeast Candida albicans that can cause thrush.

 

 

 

Why do we care?

With the increase of dental caries being reported today, oral hygiene has become the center of public concern.  Excellent oral hygiene and fresh breath demands that we brush our teeth multiple times a day.  Although the frequency of tooth brushing has become the main focus, attention is lacking as to what ingredients in tooth paste are essential.  Tooth brushing has become a part of our daily routine, but have you ever wondered what your tooth paste is made from?  With ingredients like Sodium Hexametaphosphate, glycerin, hydrated silica and propylene glycol it’s no wonder we don’t question it more.  The public has demanded an increase in organic and health food products yet toothpaste seems to be overlooked.  The research being performed by Dr. Brady and his team could have potential benefits for the oral health care industry.  With the results from their research, there is the potential to reduce the amount of chemical additives in toothpaste and substitute modified coconut oil and other natural ingredients.

This blog post was submitted by: Layla Vera

 

 

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Posted in Biological Sciences, Issues in Science, Science in the News, Uncategorized

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