Blogs

Zugunruhe or migratory restlessness is determined by the circadian clock in response to the annual cycle. In a study of the orientation of Zugunruhe in Common Starlings, the birds were placed in cages in a room where they could see the sun, including its change of position as the day progressed. As long as they could see the sun, they focused their attention towards the northeast, the correct direction for spring migration. On overcast days, however, the starlings showed no directional tendency.

Following up on my work on sensory priming during the past semester and this summer, I will continue running arena trials with a new generation of P. princeps in order to study the behavioral responses of jumping spiders towards visual and acoustic stimuli. My experiments consisted of introducing a jumping spider in an arena so that it walked into a viewing chamber were pictures suddenly appeared in an iPod screen. The pictures were of a wasp (a potential predator), a cricket (a preferred prey), and a beetle (a neutral stimulus). Each spider was shown one image per trial and during the sound trials a speaker played a wasp buzzing sound for 5 seconds every 2 minutes.  Since the trials were run between the end of the Spring semester and this summer, it is possible that the effect of age influenced the spider’s response towards the stimuli, because jumping spiders are very visual and still they showed little response towards the pictures.

You certainly do not have to be a physicist to know of gravity. Gravity is not some obscure concept mentioned only in the lingo of die-hard astronomy fans, like a “quasar" or a "red giant." Gravity is a concept known by toddlers and astrophysicists alike. From a young age, we learn that when we throw a ball up, it must come back down. We learn that if we slip on the monkey bars, gravity will bring us hurtling toward the ground. And sadly, we learn that we cannot fly. These lessons are all thanks to gravity.  But while anyone and everyone recognizes that gravity exists, it is likely that far fewer people have pondered where gravity comes from. Few have likely asked themselves, “what really IS gravity?" That is where physicists come into play, and the answer is not quite as simple as the concept itself. 

One of the most prominent great thinkers of Ancient Greece, philosopher Aristotle, took a stab at theorizing the nature of gravity in the 4th century B.C. Aristotle believed that different elements gravitated toward different sources based on their own internal nature, rather than an external compelling force. The consensus at that time was that the earth was the center of the universe, supported by the complex diagrams constructed by the Roman Ptolemy which could be used to predict the motion of the visible planets. Thus, Aristotle believed that heavy elements were trying to seek their "correct" place at the center of the universe (the center of the earth).  For this reason rocks would fall to the ground, but lighter elements like steam would rise to their own natural and "correct" place in the sky. This led Aristotle to the conclusion that heavier elements fall faster.

You certainly do not have to be a physicist to know of gravity. Gravity is not some obscure concept mentioned only in the lingo of die-hard astronomy fans, like a quasar or a red giant. Gravity is a concept known by toddlers and astrophysicists alike. From a young age, we learn that when we throw a ball up, it must come back down. We learn that if we slip on the money bars, gravity will bring us hurtling toward the ground. And sadly, we learn that we cannot fly. These lessons are all thanks to gravity. And it doesn’t stop there. We all feel gravity constantly, pulling us to the ground when we are sitting, standing, running, skipping, and jumping. John Mayer even wrote a song about it. We all know of gravity’s existence just like we all know the sky is blue. But while anyone and everyone can recognize that gravity exists, not many people have probably sat down and really asked themselves, from what source does gravity originate? What really IS gravity? And that is where physicists come into play, and the answer is not quite as simple as the concept itself. 

Gobiiformes is an order of fish containing about 210 genera and 1700 species. Gobies are marine fish which occasionally wander into adjacent freshwater areas. Their pelvic and medial fins unite and form a sucker, which they may use to adhere to objects such as plants and rocks. Some sand dwelling gobies have a symbiotic relationship with shrimp. The shrimp will dig a burrow in the soft sand substrate in which the two organisms live. The goby will then alert the shrimp to danger and they will both burrow deeper. There are also reef dwelling gobies. Some species of reef dwelling gobies exhibit a bidirectional sex change. Generally these go from female to male (protogynus), though under lab conditions the opposite direction has been induced by removing the female. When this occurs the largest male will become a female. If two males are ever placed in the same area, one will change to form a matching pair of male and female. Of course this may only work in lab conditions as in the wild, the gobies will likely simply migrate to a new area.

In every living organism, structure plays a large role in the function of certain things. Proteins make up nearly all living organisms, so understanding the structure of proteins can help us understand the overall structure and function of us and other living things. Proteins have four levels of structure: primary, secondary, tertiary, and quaternary. Primary structure is the sequence of amino acids, which are linked together with peptide bonds. Secondary structure are structures the sequence of amino acids often form into. Proteins usually have alpha helices and/or beta sheets. Alpha helices are helices, similar to the structure of DNA. Beta sheets are flat structures that can run parallel or antiparallel. Usually, the two middle sheets are parallel and the two sheets on the outside are antiparallel to those. The bonding that is involved in secondary structure is hydrogen bonding Tertiary structure is the overall fold of a single polypeptide chain. Quaternary structure is the folding of two or more polypeptide chains, subunits, that function together. The bonds that are involved in tertiary/quaternary structure are the noncovalent bonds.

Following up on my work on sensory priming during the past semester and this summer, I will continue running arena trials with a new generation of P. princeps in order to study the behavioral responses of jumping spiders towards visual and acoustic stimuli. My experiments consisted of introducing a jumping spider in an arena so that it walked into a viewing chamber were pictures suddenly appeared in an iPod screen. The pictures were of a wasp (a potential predator), a cricket (a preferred prey), and a beetle (a neutral stimulus). Each spider was shown one image per trial and during the sound trials a speaker played a wasp buzzing sound for 5 seconds every 2 minutes.  Since the trials were run between the end of the Spring semester and this summer, it is possible that the effect of age influenced the spider’s response towards the stimuli, because jumping spiders are very visual and still they showed little response towards the pictures.

There is another form of parthogenesis used by fish in order to reproduce. This form is called hybridogenesis and is also used by monocha-lucida fish. During this process a diploid ML female will produce a haploid M egg. A haploid L sperm will join with the egg, though a female is always produced by this process. However once fully maturing as an adult, the paternal portion of the genes is discarded and the female will once again only produce haploid M eggs, and the cycle repeats.

Other fish use a variety of methods to attract their mates. For instance, some will have physical traits which monopolize on certain behaviors of the other sex. For example, many female fish carry their eggs in their mouths for safety, even before fertilization. Males of this species may produce structures on the ends of their fins which mimic the appearence of eggs. The female will therefore attempt to carry the mimic eggs in its mouth, at which time the male will fertilize the eggs already in the females mouth.

Ponds are freshwater bodies of water found all over the world. These ponds host all types of organisms ranging from unicellular organisms to multicellular organisms such as fish and frogs. In ponds, groups of living things depend on the water environment and each other for their own supplements and survival (Rejesh, 2017). If a pond has more "evenness" when it comes to diversity, it's system is going to be stronger, and better equipped for survival. By evaluating pond water samples from different ponds on The UMass Campus, we should see which pond is most diverse and therefore better equipped for survival. To test what pond has a higher Shannon Diversity Index, we gathered pond water samples from two locations. We counted the organisms, identified and classified the species, charted the numbers, and then calculated which pond had higher diversity.