As a kid, as soon as I found out that some baseball bats were made out of ash wood, they instantly became my favorite tree. Fraxinus americana -- the White Ash tree, is native to eastern and central North America. It has since expanded its range to Nova Scotia, Missouri, and northern Florida and has been naturalized in Hawaii. In addition to baseball bats, ash wood has long been sought after for its use as guitar bodies, hockey sticks, tool handles, and furniture. However, in recent years it has come under threat from the Emerald Ash Borer -- an invasive species native to Asia -- and has since been identified as a Critically Endangered species.
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There are three main families of lampreys: the Petromyzontidae (Northern Lampreys), the Geotriidae (Southern Lampreys) and Mordaciidae (Top-eyed lamprey) and all of them display unique anatomy and behaviors. Most adult lampreys are parasitic blood feeders, albeit only in a marine environment, whereas juveniles burrow into the substrate to filter feed. Interestingly, they do not eat when they return to freshwater to spawn. Their mating ritual consists of both the male and female pushing large stones together to form a nest known as a redd which creates an area of low pressure where the eggs are laid and fertilized. As for their anatomy, it is important to note that that their eye musculature is extrinsic and they have arcalia -- cartilaginous nodules along their notochord. In addition, they have realtively high blood pressure and are not isosmotic, unlike hagfishes; their relatives. The brains of hagfishes are enclosed by a cartilaginous pan which leaves the top of the brain exposed, however the brain case of lampreys fully enclose their nervous tissue.
One of the biggest barriers to research into cystic fibrosis is the lack of an usable animal model for lung disease phenotype, as mice with mutations in the CFTR gene do not display such symptoms. Thus, this study aimed to create a new animal model that overcame this problem in order to further research on the disease itself, in the form of pigs. When the pigs were first born, one of the first problems they encountered was the presence of an intestinal blockage. This was avoided by circumventing the meconium ileus, much like surgery to remove intestinal blockages in humans. Thus, this proved that the pigs could survive surgery and were at least potentially viable as a model system. After this, performing X-ray tomography showed progressive thickening of airway walls and scattered infiltrates which were symptoms consistent with CF patients. Inflammation, mucus accumulation and remodeling of the lungs were all found in the CF pigs which is also consistent with the symptoms found in humans. More notably, the study suggests that the CF pigs have an impaired ability to fight bacteria even in the absence of inflammation.
There are three main families of lampreys: the Petromyzontidae (Northern Lampreys), the Geotriidae (Southern Lampreys) and Mordaciidae (Top-eyed lamprey). Most adults are parasitic blood feeders, albeit only in a marine environment, whereas juveniles burrow into the substrate to filter feed. Interestingly, they do not eat when they return to freshwater to spawn. Lampreys are peculiar in that their eye musculature is extrinsic and they have arcalia -- cartilagnious "bumps" along their vertebrae. Interestingly, they have realtively high blood pressure and are not isosmotic. They also have a brain case with lateral walls -- compared to the hagfish in which its brain is only encased by a "pan".
The nostrils of hagfish and lampreys are located on the roof of the mouth. Thus, this allows them to to take in water and "smell" even while attached to something with their mouth. Hagfishes can be divided into two classes; the Atlantic Hagfish(Myxinoidea) and the Pacific hagfish(Entatreus). The Myxinoidea class consists of 7 genera and 76 species and are the only craniates that are isomotic with sea water (i.e. their blood has the same osmolarity as sea water). Interestingly, they are covered in mucous pores which acts as their main method of defense. Hagfishes also display Protandry; they start off as males and then transform into females as they age. Generally, this is due to the fact that sperm is relatively inexpensive to manufacture even when the hagfish itself is small. Conversely, larger eggs that have a higher chance of survival are more expensive and are thus formed more easily by older, larger individuals. Their other main feature of interest is the presence of keratinized teeth on their tongue, which they use to scavenge on carcasses and perhaps prey on invertebrates. They are also unique anatomically as they do not have a skull, but instead have a cartilaginous "pan" which encases the bottom and sides of the brain, but not the top.
Some of the more common divisions of marine creatures can be divided based on more obvious characteristics. Ambulacraria can be remember as "things that can move" coming from the word "amble" which means to walk slowly. Echinoderms and hemichordates both share larval forms and one species of pterobranches have a set of pharyngial gills. Conversely, acorn worms have pharyngeal pores. Chordates on the other hand, share a defined set of synopomorphies; the presence of pharyngeal gills, a dorsal hollow nerve, a notochord, a post anal tail, and an iodine fixing gland. Interesting, tunicate larvae have all the characteristics of chordates before undergoing paedomorphosis. As a result, it has been determined that they are the sister group to modern vertebrates.
Family trees are produced by comparing shared characteristics. These characters must be homologous in order for the tree to be valid. Of note are two branches; the protostomata (stomach forms first in blastula) and deuterostomata (stomach forms second after the anus in blastula). Protostomata generally undergo spiral cleavage as part of their first cell divisions while deuterostomata undergo radial cleavage. Deuterostomata also experience a "pinching off" of the mesoderm from the endoderm while the mesoderm of the Protostomata form separately. Finally, cell fates are generally determined much earlier on in Protostomata than in deuterostomata.
After waking up, a good part of my day consists of walking, and on Thursday, I took relatively long walks on seven different occasions. These walks consisted of going to the gym, walking to class, walking to the dining hall, and walking back home, all whilst listening to music on my phone. However, the bulk of my dad consisted of sitting in class and listening to lectures on java programming, and ichthyology or discussing the genetics and treatment of cystic fibrosis. In between all of this, I found time to eath breakfast, lunch, and dinner, which consisted of a protein bar, grab n go, and a sandwich and salad, respectively.
I would like to focus on something fairly unique for my methods project. The first organisms that come to mind are the koi and the flora inside the Durfee Conservatory. The fact that both of them are stationary make them prime candidates for this project as it would be easily replicable. This is important since picking more motile or migratory organisms such as insects or birds would make this project exceedingly difficult if not impossible to replicate. Another possible avenue would be to decide on observing any number of the beautiful trees on campus, for the same reasons as above.