Author Archives: Alexandra Christina Nielsen

Fact or fiction: are blue eyes more sensitive to light?

Having blue eyes I am a eye-color-minority in my predominately brown eyed Italian family and being such I always used the excuse that my lighter eyes were sensitive to the sun when reaching for sunglasses before a dinner outside. Without them I would be continuously squinting which would give me a headache and make my eyes tear up. Why did the sun not seem to irritate their eyes as it did to mine?

Blue Eye B&W Macro

Scientifically, yes lighter colored eyes are more sensitive to bright lights and the sun because a lighter color iris allows more light to pass into the retina of the eye. Lighter color eyes such as blue or light green are intact missing a pigment called melanin or have much less of it than a darker brown or hazel eye. In fact the amount of melanin in the eye determines it’s color; the more melanin the darker the eye color, the less melanin the lighter the eye color.


As this diagram shows the color of a person’s eyes is directly caused by the amount of the pigment melanin is present in the eye. In eyes of lighter color with less pigment the light is able to pass more easily through the iris. With the presence of melanin comes a sort of protective filter which acts to reflect light out of the eye consequently allowing the eye to be less aggravated by brighter light. Because the lighter colored eyes have less protection from the sun (they let more UV ray in) those with light eyes are at a higher risk for eye cancer (Vann). It is suggested that people with light eyes wear sunglasses often, with UV ray protection.  Although it has not been proven that people with blue or green or gray eyes who have eye cancer developed it as a direct result from UV ray exposure there is a strong link or correlation; it seems to make sense. Because people with lighter colored eyes have less of the pigment they have more areas of their eye exposed to the sun and dangerous UV rays. There is less of a barrier between lighter eyes and forces in nature that may negatively impact the exposed or uncovered eye.

One interesting study I found relating to eye color was a study done which found that people with darker eye colors were more agreeable than those with lighter eyes. The study however was conducted in Australia. “Researchers surveyed 336 participants, 63 percent of whom were Northern European in ancestry” (Brice). The participants of the study were asked to answer questionnaires that measured aspects of their personalities like agreeableness and conscientiousness. The correlation of darker eyes and a more agreeable personality only applied to Northern Europeans, not any other Europeans from the south or east. Overall I’d have to say the link between eye color and personality is extremely weak. There is only a small correlation and I would argue it’s even just do to chance since the study was rather small and the correlation was only found in a certain group of people from a geographical area.

What I took away from this study that if you have lighter colored eyes it would be a good idea to wear sunglasses with UV protection on a sunny day.




Can a lack of sleep shrink your brain?

Could a lack of sleep affect the actual size of your brain? A new study shows a strong link between poor quality sleep and the size of the brain.

It started with a study done at the University of Oxford and the University of Oslo in the past month where they examined about 150 adults (ages 20-80). The members of the study took a survey and described their sleeping habits. The survey included question like  how many hours of sleep they were getting a night, how soundly they thought they slept, how often they would wake up in the middle of the night, how tired they were during the day, and how long it took them to fall asleep. However we can not be sure how accurate these surveys are since people filled them out based on their memories and opinions; the scientists did not measure any of these factors for the subjects. After the initial survey the researchers took an MRI scan of each individual’s brain. they revisited the subjects 3 and half years later and did a second MRI scan of their brains. What the scientists found was those of those adults who reported poor sleep habits had a decrease in volume and size in certain parts of the brain in contrast to those who had healthy sleeping habits in which there was no size decrease in the brain. The researchers saw “shrinkage in one part of their frontal cortex and some deterioration, throughout three other parts of the brain, including parts involved with reasoning, planning, memory and problem-solving” (CBS). However the study did not measure these parts of the brains ability during the trial so it is hard to say weather they were negatively affected such as slower thinking or bad memory. 


This study does not yet prove that sleep deprivation or poor sleep habits are the direct like to smaller brain size however and from class we know that correlation does not equal causation. The study only shows a correlation or association between the two variables. The possibility of reverse causation could also be a factor coming into play in this study. For example, is it the unhealthy sleeping habits that cause brain shrinkage or shoes the shrinkage in brain size cause sleep problems? It will take some more testing to figure it out; perhaps they could look at the sleep patterns of those with preexisting smaller areas of the brain and examine their sleeping habits and quality in a blind trial so the participants don’t know what kind of sleep pattern they are supposed to have.

Even though poor sleep habits (not lack of sleep) can not be considered the direct cause of decreasing brain size researchers hope to establish this further and in the meantime encourage people to maintain healthy sleep habits while we are unsure of the level of effect it has on the size of our brains.


Could you really be bored to death??

I’ve been there: sitting in class, eyelids heavy, way past zoned out of what my teacher is saying, telling myself and maybe whispering the the kid sitting next to me that I’m “bored to death in this class”. Could a class THAT boring put you into a state of boredom that would lead to your death? Well, not exactly but being “bored” for large portions of your life can lead to an early death (most likely by heart disease or stroke) than if you are more entertained in life. Bottom line: the more bored you are the more likely you are to die prematurely.


What this theory is based off of is a major scientific study which begin in London in the 1980’s. Over 7,500 civilians ages 33-55 were asked a series of questions about their lives such as how bored they had been at work in the last month and how healthy and physically active they were ( ). Those participants who had said they were bored also said they did not participate in much physical activity and view their health as worse than the other members of the group. Years later in 2009 researchers went through the members of the survey to see which members were still living and which ones had died. The researchers found that those who had been more bored at work were more likely to have died at an early age and in most cases from a fatal heart attack. Scientists think this connection exists because people who are bored are more susceptible to feel in unhappy, unmotivated and thus lead to negative habits such as drinking and drug use. And it is those unhealthy habits that would lead to their early death rather than boredom itself; boredom is just a vessel for these negative or unhealthy behaviors which caused the death of the member of the survey who reported being significantly bored throughout their lives.

While there is not a direct link (direct causation) to boredom and premature death, this study shows that is can be a gateway or a strong link to it; there are other factors however that stem from the condition of being bored. Being bored leads to a series of other behaviors and habits which can be detrimental to your health. Since there have not been multiple trial like this performed in comparison scientists are hesitating to establish that direct link between boredom and death by heart failure. No need to be worried about dying early if you’re bored a few hours a day or a week; it was only those people with “chronic” and consistent boredom on a daily basis that is becomes a lifestyle that should be worried. If we continue to keep our minds entertained boredom will not take our lives earlier than expected.


Can one rotten apple really spoil the whole bunch?

You’ve all hard the expression “one bad apple can spoil the whole bund” be applied to a group of people with one member who is a bad influence. The fear is that the one person who is the poor example will have a negative effect on the other people they associate with. This saying came from some sort of truth; a scientific truth. I began to wonder if you put an actual rotten apple in a bowl of fresh ones, would the spoiled apple quickly ruin the fresh apples?


Turns out this is a scientific truth that when one rotten apple is exposed to ones that are not it will cause the fruit to ripen faster and eventually rot. This is because as apples ripen they give off a hormone in a gaseous from called ethylene which is a catalyst for ripening fruit. When a well ripened fruit is in close vicinity with other fruits the gas is absorbed into the other fruits causing them to ripen. Logically the riper a piece of fruit the more ripening gas it is going to produce and a rotten piece of fruit is going to produce a whole lot more of that ethylene gas. If you have a piece of fruit that is not ripe at all putting it in a sealed bag with a piece of ripe fruit with quicken the process; the ethylene gas is trapped in a more confined area and it delivered in larger concentrations to the fruit in the container.

Most recently scientists have been working on a delayed ripening technology so that fruits and vegetables have a longer self life at super markets before they got rotten. Once a fruit or vegetable begin the ripening process it is irreversible. Thus scientists are trying to prevent the process from starting altogether. Typically former pick and ship their produce while they are still unripe and once they produce reaches the destination they are sprayed the the ripening inducing hormone ethylene. There are drawbacks to this approach however because fruits that have been harvested prematurely may result in poor taste and quality and fruits transported for long periods under refrigeration also have the tendency to lose their quality (ISAAA).

To prevent the poor quality of this fruit scientists have discovered they can suppress certain genes in the fruit or insert certain genes to delay the ripening process. The scientists can insert genes that reduce the amount of hormones available for ethylene production which slows the process of suppress genes that are needed in the final stages of biosynthesis in producing ethylene for ripening. This use if the genetically modifying process has been approved in the US and has been label safe for consumption. With this technology farmers can now wait until their crops are matured to pick them from the vine and extends the shelf life as well.

However these products are considered to be genetically modified and GMOs have been getting a lot of bad press recently because there are still being studies conducted to find out how exactly they affect human health. Much like the process of discovering smoking caused lung cancer and was bad for humans, the scientific world is undergoing to process of determining whether or not GMOs have an adverse effect on the human body and if they do the what degree. A trial was done on rats examining the effects of GMOs. some rate were fed a genetically modified potato while others were fed one that had not been modified. There were noticeable differences in the digestion of the modified potato. However this study was criticized because the potatoes were modified with a substance known to be toxic to mammals; however the scientists of the rat study claim they were only testing the methodology of GMOs. In order for the study go genetically modified foods to go further scientists must start using chemical which are actually used in foods available for sale in the US. I thought this was a good example of how scientific studies are always susceptible to scrutiny as a method of further growth and envelopment for the good of human kind.





Side Effects of Sugar

Of course naturally occurring sugar in fruits is healthy but I am talking about refined sugar. It has several negative side effects the most obvious being from an overconsumption of processed sugar over a long period of time which can lead to being overweight or being obese which leads to a whole other series of health problems. A newer sturdy examined sugar intake of men and women over the course of 15 years. The greater the amount of sugar that person consumed overall, the greater the health risk of heart disease was. In fact people who consumed about 15% of their daily calories from added sugar had a 18% higher risk of dying from heart disease, compared to people who only took in very little added sugar (Forbes). When this trial was done it spanned among women and men of varying age ranges, weights, and physical activity levels showing there is most likely a direct link between sugar consumption and the heart. There is still room for a third variable to be affecting the sugar and heart disease; the direct causation is not definitive here more studies would have to be done since this was simply an observational trial.


Have you ever found yourself just finished a slice of cake, ice cream, or a piece of candy and instead of being satisfied you have the craving for another sugary sweet? While the dessert might be THAT good it could be due to your brain actually craving it. Besides the strong link between sugar consumption and heart disease the refined substance has no minerals, vitamins, or proteins in it leading people to name it as an “empty calorie”. There have also been some studies in which sugar consumption has been shown to cause a release of dopamine in the brain. Dopamine plays a role in addiction in that it controls the reward and pleasure centers in the brain. For example eating sugar causes pleasure so we naturally want to continue to “reward” ourselves with more sugar. Thus rather than being physically addicted to sugar you can become mentally addicted. Researchers at the University of Florida found that obese and compulsive eaters were irresistibly drawn to images of junk food in the same way cocaine addicts were when shown a bag of the white powder (Huffington Post). A recent study done at the University of Edinburgh has shown no conclusive evidence that people become addicted to chemical substances in certain foods. There is very little evidence currently proving that sugar is addictive or that people have a dependence for it. However there are several studies that show sugar can be addictive. For example a suds done by Princeton university on rats showed that after consecutive days of feeding them sugar the rats suffered withdraw symptoms when the scientists removed the sugar from their diets. The bigger issue is our bodies are not used to handling the amount of sugar humans are consuming today. Sugar is in a overwhelming amount of processed and “natural” foods today. In small amounts sugar is not deadly or addictive. But what do you think? In your own experience can food products containing sugar be addictive or not?



Don’t you wish you were a bilingual baby?

Being a boring monolingual young adult I have always been fascinated at my peers’ ability in mastering a second or even third language at a young age beside English. I always thought these bilingual kids were so much smarter than I was for I surely did not have the capacity to become fluent in a second language as well as them in a mere few years as they did. It turns out my hunch was right; those infants and young children who grow up in a home where 2 or more languages are spoken have increased cognitive advantages when compared with a child of the same age who only knows or speaks a single language.


The  National University of Singapore and the Singapore Institute for Clinical Sciences worked in conduction with multiple hospitals in Singapore to examine bilingual young children as Singapore has a relatively high number of bilingual families compared to most cities in the world. What the researchers did was conduct a visual test among bilingual and monolingual 6 moth old infants. Because the children are so young and their speech skills are still developing the researches throughout a visual test would be the most accurate and effective in their study. The infants were shown two different pictures; they were only shown the second picture when they became disinterested in the first which was a familiar object such as a teddy bear. the bilingual babies became disinterested in the images faster than the monolingual babies. The second imagine they showed the babies was a new animal, something the babies were unfamiliar with; the bilingual babies were more interested in the second unfamiliar picture than they were with the first picture of a teddy bear. My question about this particular study is how did the scientist objectively and factually determine when the babies were “bored” with the image if this was purely a visual test? How did they measure the disinterest? 


The researchers in this study were able to connect it to previous studies in which the infants’ fondness for the second unfamiliar image and the speed at which they become bored with the images correlate with cognitive preference in multiple areas “such as advanced performance in concept formation, non-verbal cognition, expressive and receptive language, and IQ tests” (ScienceDaily). Previous studies associated with this visual testing of bilingual infants found that babies who were bored with the image at a quick rate “demonstrated higher performance in various domains of cognition and language later on as children” (ScienceDaily). This relates to our class discussion about correlation v. causation. While I think it is likey that exposure to two languages is a cause of better brain function perhaps there are other factors undiscovered. The scientists followed these 6 month old until they reached the age of 9. They hope to examine the group of infants who were exposed to 2 languages at birth and the monolingual infants who would eventually learn a second langue to see if the exposure to a second langue at such an early age has long term cognitive benefits as well. 

Researchers came to the conclusion that bilingual children have water or better information processing skills because form such young age they are learning to speak and differentiate between two languages. I think this study is very interesting because it makes sense that of young children are constantly stimulated by a variety of words and phrases and not jus the same ones repeated daily their brain would be more advanced in telling them apart and process the meaning of the words when they reached the age to begin speaking.

The original findings of the study can be found here.


Initial Blog Post

Hey everyone!

My name is Alexandra, I’m a freshmen and I’m planning to major in history (however that’s definitely subject to change). I signed up for this course because I really disliked traditional high school science and I was just terrible at it (except for biology) so when I read the course description for this class and saw it wasn’t a traditional science class of course I opted to take it to fill my science requirement. I’m not planning on majoring in science because it was never a strong area for me in school and I don’t want to fail out of college. This is a picture of the Ponte Vecchio in Florence, Italy or “Firenze” in Italian because who doesn’t love Italy.