Drafts

In this study, the researchers were exploring the genetics behind eating disorders. Researchers know that there is approximately a 50 to 80 percent chance of developing an eating disorder based off of the little knowledge known about specific genes. These researchers decided to take a new approach to dig deep in the genetics behind eating disorders and clear up some of the gray area that remains. This study examines the neuropeptide/neurotrophic factor in the signaling pathway which function in the brain. These factors work, in the brain specifically, to regulate appetite. They also work in other areas of the body such as the gut to assist in digestion and nutrient absorption.

In the phylogenetic tree created on the MAFFT program, there were 37 redundant entries removed, and about four natural groupings could be identified. There were no clear outliers on the tree (Figure 6). The Bradi1g72430 gene was found to be most closely related to a Oryza sativa gene, OSNPB_030183800. Within its natural grouping, the gene was most closely related to O. sativa and Brachypodium distachyon, then Arabidopsis thaliana genes (Figure 6).

Cross-sectioning of wildtype and mutant plant stems revealed mutant stems to have a smaller diameter than wild type, and based on the dyed sections, mutant plants seem to have thicker polysaccharide and lignin walls with smaller openings in the center of the stem.

The four mutant plant sequences obtained through Sanger sequencing were labeled S31-34. S31’s first quality base was the 50th base, while the last quality base was the 615th base. S32 had no quality bases. S33 and S34’s first quality bases were also the 50th base, while the last quality bases were the 600th and 620th bases respectively. The NCBI pairwise BLAST between the Sanger and reference genome sequences revealed one misalignment at the beginning of the sequence, but in between the beginning and end, the Sanger and reference sequences were perfectly aligned except at the 133rd position. This was confirmed to be the position of the NaN1898_Bd1_70884553_Het mutation, and it was located on the 133rd position of the chromatogram (Figure 5). On the chromatogram, there were two peaks, G and A, at the 133rd position, although the algorithm read it as A. This indicated a heterozygous mutation with a wild type G base and mutant A base, which is consistent with the NaN1898_Bd1_70884553_Het mutation. This mutation was at position 715 in the whole genome sequence.

The amino acids in proteins are joined together by peptide bonds to form polypeptide chains; a protein consists of one or more polypeptide chains. Like nucleic acids, polypeptides have polarity under physiological conditions: one end (often called the amino end) has a free amino group (NH3+) and the other end (the carboxyl end) has a free carboxyl group (COO−). Proteins consist of 50 or more amino acids; some have as many as several thousand.

This week I babysat my friends hamster, Cayenne. She is a Syrian Hamster. Cayenne is a large hamster so we nicknamed her Chubby. Everyday, I had to make sure she had enough food. Cayenne needs about 1/3 cup of hamster food everyday and every other day she can have fresh vegetables and fruits. To get her use to me, I wore gloves in case she would bite and gave her a sunflower seed as treats. I filled her water bottle and when I was down to about 1/4 full, I refilled it for her. Hamsters are nocturnal, so when I was in class I would cover her tank with a blanket and closed the blinds so she could sleep. Around 7 or 8pm she would start moving and then when she was fully awake by 9 or 10pm, I would take her out so she could run around in her hamster ball for about 45 minutes. After then, I would put her back in the tank so she could get some food and water. After that she spends all nigh on her wheel, which can get quite loud sometimes. Cayenne is asleep by the time I get up for class in the morning. 

Hummingbirds have adapted their digestive system in order to sufficiently support their high caloric intake. They use their newly ingested sugars as a fuel for flight. They are able to quickly digest sugars for immediate use. It takes a hummingbird about 40 minutes to turn food into fuel whereas it can take a human up to 40 hours to digest. This is partly due to their small digestive tracks and the absorption of nutrients across the intestine. They also have a high capacity for paracellular and transcellular movement of glucose.

Birds have a special organ called the syrinx, that allow them to sing the way they sound. It is located on the trachea to produce sound. It is similar to the mammalian larynx but the way air is used is different. In the syrinx 100% of the air is converted to sound where the larynx only uses 2%. The vibrated air passes through the syringeal passageway to project on the tympaniform membrane. This vibration is the result of how birds can vocalizes. The syrinx is a complex organ itself but the muscle attached around it is also complex. There are layers of muscle structures to create fine adjustment of vibration. Sound produced by the syrinx can be filtered to change the loudness and the pitch. The experiment done to prove that sound travel faster than helium atmosphere showed sound produced in such atmosphere had different pitch and frequency than the sound produced in our normal atmosphere. The understanding of syrinx and physics of sound helped scientists to learn more about vocalization.

In order to be familiar to birds’ vocalization, there are terms that one's needs to study such as:  Amplitude (maximum energy), Fundamental tone, Frequency (number of complete cycles per unit of time), Glissando (bleeding of one tone into the next), Harmonic (a tone in the series of overtones produced by a fundamental tone), Hertz (one cycle per second), Modulation (form of a sound: carrier wave), Oscillograph (a device that records oscillations as a continuous graph), Overtone , Pitch (relative position of a tone in a scale, as determined by its frequency), Resonance (intensification and prolongation of a sound), Sinusoidal waveform (y=sin x), Sonogram (display of the frequency of a sound related to time), and Tone (distinct pitch and quality).

This treatment exploits the cross-presentation function of the immune system that allows antigen-presenting cells (APCs), especially dendritic cells (DCs) to phagocytose extracellular antigens and display them with MHC class I molecules to CD8+ T cells. Typically, extracellular antigens are phagocytosed by APCs and presented through MHC class II to CD4+ T cells, while endogenous antigens are presented through MHC class I to CD8+ T cells. This ability to display extracellular (vaccine-injected) TAAs on MHC I is crucial in the activation of CD8+ T cells in killing the tumor. There are currently two routes for this mechanism of cross-presentation: cytosolic and vacuolar (Immune Response 2014). In the cytosolic route, the extracellular antigen is phagocytosed and then actively transported to the cytosol, where it is cleaved by a proteasome, transported to the ER, and loaded onto MHC class I. In the vacuolar route, the extracellular antigen is phagocytosed and then at the ER is incorporated into an early endosome with lysosomal enzymes and MHC class I, which subsequently displays the antigen on the plasma membrane (Immune Response 2014). The specific pathways involving cross-presentation remain unclear to me and requires further research. I also need to look into mechanisms of APC function, especially those of dendritic cells, so the cancer vaccine treatment will be able to work properly.

Researchers found a connection between the hormone noradrenaline and perception of images. It was found that people with higher levels of noradrenaline in their systems were able to discriminate low quality images better. What the researchers attempted to figure out was whether if noradrenaline and an effect on sensory perception and if noradrenaline improved perception of images. Noradrenaline plays a role in the late processing of the cerebral cortex. Therefore, it would determine whether the image would be brought back into the person’s memory. Typically, noradrenaline is expressed during arousal but there are more functions to the neurotransmitter that was found.