Blogs

Pacemaker cells in the SA node receive direct input from the autonomic nervous system , the input can alter the frequency of action potentials which is basically the only thing that determines heart rate. Also the Sympathetic neurons project into the AV node. They influence the speed with which action potentials are conducted. This leads to a decrease in the duration of the systole which allows the diastole to be able to fill the heart with enough blood. Also the parasympathetic neurons can cause an increase in the length of the systole by decreasing the speed of conduction of the impulse.

In this experiment we hope to find specific differences between physical attributes of the campus pond and nearby puffers pond. We hope that results of this experiment will expose significant differences between the two bodies of water and lead to a better understanding as to why the the differences occur The techniques and procedure used and were pulled from the “Plankton diversity of in a landscape of shallow water bodies”  research paper written by Maria A. Rodrigo, Carmen Rojo and Xavier Armengol.

Planarians play an important role in water based ecosystems and can serve as bioindicators. Planarians can be used to determine the quality of a freshwater source. Abundance and presence of planarians can provide information about a given ecosystem or body of water. Planarians are sensible to environmental changes and pollution of the ecosystem they reside in. If pollution levels are above a certain degree, planarians would not be able to reproduce and eventually will die off. Other factors that can cause the distribution and presence of planarians to be skewed negatively are temperature and ecological processes. Extreme water temperatures can cause the environment to be uninhabitable for planarians.

Other factors that can cause the distribution and presence of planarians to be skewed negatively are temperature and ecological processes. Extreme water temperatures can cause the environment to be uninhabitable for planarians.

Planarians are sensible to environmental changes and pollution of the ecosystem they reside in. If pollution levels are above a certain degree, planarians would not be able to reproduce and eventually will die off.

Planarians play an important role in water based ecosystems and can serve as bioindicators. Planarians can be used to determine the quality of a freshwater source. Abundance and presence of planarians can provide information about a given ecosystem or body of water.

Clearly Jensen’s remarkable story of facing the odds stacked against her due to a failed abortion are a massive inspiration to the pro-life movement. Her monumental life is a perfect example of the lives that anti-abortionist’s aim to protect. Jensen is a perfect example of Marquis’ “future-like-ours” theory, which is Marquis’ central argument against abortion. Marquis argues “The loss of one’s life deprives one of all the experiences, activities, projects and enjoyments that otherwise would have constituted one’s future” (Marquis 189). Jensen shows this clearly, as a survivor of abortion, all the things she has done with the life she has been given were attempted to be stopped with an abortion. Even with the abortion providing massive setbacks in Jensen’s life, she has still lived a life of happiness, meaning and international recognition.

Not surprisingly, Jensen’s story quickly started to spread, not only through the United States, but in Italy and across the world. Jensen began speaking to others about her story and became a figure in the anti-abortion movement. She met with British Prime Minister Tony Blair and U.S. President George Bush. Bush signed the Born Alive Infants Protection Act, which protects those infants born during failed abortions, like Jensen. A movie was even made loosely based on Jensen’s story by the name of “October Baby” and Jensen’s singing was featured in the movie with the song “Ocean Floor” (giannajensen.com).

Ruffs and Reeves:

As with nearly all evolutionary concepts, the deciding factor that determines behavior is the return on investment regarding behaviors, morphology and reproductive success. Evidence of this is reinforced by the dichotomous mating systems observed in Reeves. Males of is species fall into one of 2 categories depending on their allele distribution. Homozygous males have darker feathers and are territorial while the heterozygous males are lighter colored and act as satellite wanders. As seen in Leks and other group settings, species who control territories often have a higher reproductive success rate. However, they also expend more energy by protecting their territory and engaging in displays to reinforce their dominance. Conversely, the wandering males expend far less energy during the breeding season, but have a reduced reproductive success rate.  This dual-reproductive system has been conserved as the ratios of resource allocation: reproductive success are roughly equivalent between the 2 phenotypes. This shows that breeding systems are not only complicated, but can even vary between individuals in a single species.

DNA recombination -
- an example of gene translocation is the antigen receptor gene in the vertebrate immune system
- in B lymphocytes, DNA recombination (aka VDJ joining) leads to the expression of one particular variable (V) region gene for each
immunoglobin (Ig) light- or heavy-chain gene
- in the Ig k light-chain genes, there are >300 germline V segments and one constant (C) gene locus containing 4 joining (J) segments
and an enhancer region
- once the B cell has picked its AB, it proliferates many clones of the same antibody and we can fight off the immune attack
what are variable regions, it is random
- in the chromosome in the B cell, this is where its happening, a permanent excision of this part of the DNA
- the ones that aren’t good, die
- promoter sequence and enhancer (drives expression, in the intron, between variable and constant domain)
- DNA deletion brings a promoter carried by each V gene segment and the enhancer region b/w the J and C gene segments into
proximity, thus activating the translocated gene
Gene Conversion -
- this is another gene-translocation mechanism that activates one particular member of the multigene family (found in yeast mating-type choice and antigenic variation in African trypanosomes)
(- chicken Ig and T-cell receptor genes use gene conversion for their expression and diversification)
- the cell makes a copy of the gene and inserts it into an expression casette
- a copy of the gene to be activated is transferred into the expression cassette located remotely from the gene cluster