Columbia Undergraduate Science Journal

SEPHI of Exoplanets Kepler-504 b, Kepler-315 b and Kepler-315 c

2024-03-01T23:07:11+00:00

The search for habitable exoplanets has improved with every passing year. New methods and advanced instrumentation with higher precision help find more habitable exoplanets and refine existing parameters of highly likely habitable exoplanets. This paper presents the Statistical-likelihood Exo-Planetary Habitability Index (SEPHI) values for Kepler-504 b (of star Kepler-504), Kepler-315 b, and Kepler-315 c (both revolving around star Kepler-315).^1,2,3 SEPHI is based on the geometric mean of the likelihood Gaussian estimation of four different comparison criteria with Earth as the only place we know harboring life: Telluricity, Atmosphere and Planet Gravity, Surface Liquid Water, and Magnetic Field.^4,5,6 The seven physical characteristics of exoplanets have been used to calculate those four criteria: planetary mass, planetary radius, orbital period, stellar mass, stellar radius, and stellar effective temperature. This is a follow-up to previously calculated ESI values for the three exoplanets mentioned above, with Kepler-504 b and Kepler-315 b having a high ESI of 71.23% and 69.44%, respectively.⁷ It has been found that Kepler-504 b (with a host M-type star (small red dwarf)) has a SEPHI value of 0, Kepler-315 b (with a host G-type star) has a SEPHI value of 0, and Kepler-315 c (with a host G-type star) has a SEPHI value of 0. Thus, more than a combination of host star type, the orbital radius of exoplanet, and the final ESI to determine probable habitability, a further in-depth analysis through SEPHI can help us confirm its actual habitability for Earth-based life.

Ascending Arousal Network Connectivity in Disorders of Consciousness: A Diffusion MRI Study

2024-03-02T04:57:21+00:00

The human brain gives rise to a great variety of conscious experiences. Patients with disorders of consciousness, a state characterized by the dissociation of awareness and wakefulness, are particularly noteworthy. This study attempts to find key biomarkers of the disorder of consciousness state and discover key regions of the brain that govern consciousness. The focus is on the ascending arousal network—a network of nodes and edges representing connections from the brainstem to subcortical (thalamus, hypothalamus, basal forebrain) nuclei and reaching the cerebral cortex. Previous studies using animal models have demonstrated a high prognostic value of the ascending arousal network in relation to consciousness. This study conducts a diffusion tensor imaging analysis and generates a tract count plot to illustrate differences in connectivity between (N=6) healthy controls and (N=6) patients with chronic disorders of consciousness. Each region of interest was isolated to investigate its specific role and impact on consciousness. A principal component analysis was performed to assess the separability of the two cohorts. The results found each of the regions of interest to be significantly (p<0.05) disrupted in patients with disorders of consciousness. They contributed equally to the linear separability of the two cohorts. This is consistent with previous research and hints at the importance of the ascending arousal network in governing consciousness. These changes are likely associated with the many pathological deteriorations associated with an impaired cognitive state, such as neuronal loss, gliosis, and the degeneration of white matter tracts that connect critical areas of the brain involved in consciousness.

Recent Progress in Engineered Oncolytic Viruses

2023-03-02T04:59:11+00:00

This review examines recent research in engineered oncolytic viruses and applies a thematic analysis to identify trends in the field. The major themes identified are tumor microenvironment remodeling, enhancing virus efficiency, treating slow-growing tumors, tumor targeting specificity, and combination with chimeric antigen receptor-T cell therapy. The tumor microenvironment plays a significant role in cancer progression through factors like immunosuppression and hypoxia. Engineered oncolytic viruses may be used to remodel aspects of the tumor microenvironment to favor and facilitate an immune response. Another major consideration in the development of oncolytic viruses is their efficiency in inducing antitumor effects. Viral vectors may be engineered with pro-apoptotic or pro-inflammatory signaling molecules to cause cancer cell death or mediate immune cell infiltration, respectively. Slow-growing tumors present a challenge to oncolytic virotherapy since many viruses infiltrate tumors through infected daughter cells arising from cancer cell division. This challenge may be overcome by engineering viruses to maintain a high viral load in infected cancer cells and drawing a sustained immune response. A concern in the development of oncolytic viruses is the issue of viral tropism and infection specificity. Although some viruses have limited tropism, oncolytic viruses may be engineered to specifically target tumors using cancer-specific receptor-ligand mechanisms. Oncolytic viruses may also be used in conjunction with chimeric antigen receptor-T cell therapy to reduce immunosuppression and enhance chimeric antigen receptor-T cell infiltration of tumors. This poses a promising approach in oncology research and treatment.