Tackling Demotivation in STEM Fields: A Student’s Perspective

The fields of STEM/STEAM are ones in which curiosity and creativity meet a very high level of rigor. When navigating such a field, staying motivated and maintaining belief in oneself and one’s intelligence can prove difficult. Self-doubt and discouragement quickly creep in for many students, as they did for me at times. In this piece, I give an account of my STEM journey, from high school chemistry to science fairs, the challenges and disheartening moments that I faced, and the growth and inspiration that came out of them that I take with me as I begin to pursue a career in STEM

Etiology, pathogenesis and future prospects for developing improved vaccines against bluetongue virus: A Review

Bluetongue is a viral disease that primarily affects sheep, occasionally goats and deer and, very rarely, cattle. The disease is caused by an icosahedral, non-enveloped, double-stranded RNA (dsRNA) virus within the Orbivirus genus of the family Reoviridae. It is non-contagious and is only transmitted by insect vectors. BTV serotypes are known to occur in Africa, Asia, South America, North America, Middle East, India, and Australia generally between latitudes 35°S and 50°N. It occurs around the Mediterranean in summer, subsiding when temperatures drop in winter. The replication phase of the bluetongue virus (BTV) infection cycle is initiated when the virus core is delivered into the cytoplasm of a susceptible host cell. The 10 segments of the viral genome remain packaged within the core throughout the replication cycle, helping to prevent the activation of host defense mechanisms that would be caused by direct contact between the dsRNA and the host cell cytoplasm. This review presents comprehensive information on etiology, pathogenesis, prevention and control of the disease.Key words: Bluetongue, orbivirus, pathogenesis, prevention

Determination of genotoxic stress in feral populations of bullheads and carp using the alkaline single cell gel assay.

Monitoring genotoxicity of the environment using endemic organisms as sentinels requires the development of sensitive assays. Towards this end, I explored the feasibility of applying the ALKALINE SINGLE CELL GEL (SCG) or COMET ASSAY. This approach involves detection, under alkaline conditions, of cell DNA fragments which on electrophoresis migrate from the nuclear core resulting in a \u27comet with tail\u27 formation. The length of the tail has been correlated with the level of genotoxicant exposure in a number of organisms. The fish used in this study were benthic feeding bullheads (Ameiurus nebulosus) and carp (Cyprinus carpio). In preliminary studies, on electrophoresis of erythrocyte DNA under alkaline conditions I found a linear increase in the DNA length:width ratio over a broad range of cyclophosphamide (a clastogen) doses. Subsequent examination of two direct acting mutagenic agents (methyl methanesulfonate (MMS) and N-methyl-N-nitrosourea (NMU)), two indirect acting mutagens (benzo(a)pyrene (B(a)P)) and 7,12-dimethylbenz(a)anthracene (DMBA) and two cell cycle specific agents (methotrexate (MTX) and colchicine) over a range of doses showed that all, except the lower methotrexate concentration, resulted in significant (p $\u3c$ 0.001) DNA damage in fish erythrocytes. Freshly caught bullheads from seven different sites showed a wide range of DNA damage. Bullheads from Big Creek (western Lake Erie), Hamilton Harbour (western Lake Ontario) and a number of sites along the Detroit River gave ratios v ranging from 3.36 to 4.65. Samples from Lake St. Clair, Thames River, Lake Huron and Port Franks gave ratios ranging from 1.30 to 2.19. Fish from a hatchery in Brockport, New York, gave ratios between 1.35 and 1.40. Based on polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB) levels, the sediment at the Detroit River sites is considered to be heavily polluted. Bullheads from Big Creek, maintained in the laboratory for three months, gave ratios which dropped from 4.78 to 1.41. The latter are similar to those obtained in hatchery-bred fish. Carp from Big Creek gave ratios of about 4.50, while carp from Lake Huron and laboratory-maintained carp gave values of 1.23 and 1.36, respectively. Bullheads placed in cages at three different sites in the Detroit River, one near Lake St. Clair (Peche Island), and the other two midway between the source and the mouth (near Turkey Island and in the Trenton channel) showed significant increases (p $\u3c$ 0.05) at two sites (Turkey and Trenton) after two days of exposure. The level of damage increased with the duration of exposure. Bullheads caged at two other sites (Big Creek and LaSalle), for eight days also showed significantly higher ratios than controls (p $\u3c$ 0.01). Finally, DNA length:width ratios for bullheads exposed to sediments from Lake St. Clair (relatively clean) did not differ from the control group ratios. In contrast, animals exposed to Big Creek sediment (highly polluted) showed an increase in DNA ratios. The results, from the bullhead and carp systems, indicate that the SCG assay is extremely sensitive and should be useful in detecting DNA damage caused by environmental contaminants. Moreover, the results from freshly caught fish, fish placed in cages and fish placed on sediment were consistent suggesting that any of these approaches could be used in monitoring a particular habitat.Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1997 .P36. Source: Dissertation Abstracts International, Volume: 59-08, Section: B, page: 3911. Adviser: M. Petras. Thesis (Ph.D.)--University of Windsor (Canada), 1997

Little Smalltalk in Java

Little Smalltalk is a small, reasonably fast, easy-to-understand, easy-to-modify Smalltalk system. The system was originally developed in 1984 as a part of an implementation project to develop a minimal Smalltalk system, closely resembling Smalltalk-80. The sys­tem was developed in C. The current project is an experiment to port the Little Smalltalk: system to Java with the dual-aim of testing the usefulness of Java for developing interpre­tive systems and also trying to make Little Smalltalk system reach a larger audience thru the world-wide-web

Monitoring the initial DNS behavior of malicious domains

Attackers often use URLs to advertise scams or propagate mal-ware. Because the reputation of a domain can be used to identify malicious behavior, miscreants often register these domains “just in time ” before an attack. This paper explores the DNS behav-ior of attack domains, as identified by appearance in a spam trap, shortly after the domains were registered. We explore the behav-ioral properties of these domains from two perspectives: (1) the DNS infrastructure associated with the domain, as is observable from the resource records; and (2) the DNS lookup patterns from networks who are looking up the domains initially. Our analysis yields many findings that may ultimately be useful for early de-tection of malicious domains. By monitoring the infrastructure for these malicious domains, we find that about 55 % of scam domains occur in attacks at least one day after registration, suggesting the potential for early discovery of malicious domains, solely based on properties of the DNS infrastructure that resolves those domains. We also find that there are a few regions of IP address space that host name servers and other types of servers for only malicious domains. Malicious domains have resource records that are dis-tributed more widely across IP address space, and they are more quickly looked up by a variety of different networks. We also iden-tify a set of “tainted ” ASes that are used heavily by bad domains to host resource records. The features we observe are often evident before any attack even takes place; ultimately, they might serve as the basis for a DNS-based early warning system for attacks

Rate and Frequency of Urease Inhibitor Application for Minimizing Ammonia Emissions from Beef Cattle Feedyards

Reduction of ammonia emissions from animal feeding operations is important from the perspective of environmental policy and its impact on agriculture. A laboratory study was conducted to evaluate how rate and frequency of urease inhibitor application affect ammonia emissions from simulated beef cattle feedyard manure surfaces. The urease inhibitor N-(n-butyl)thiophosphoric triamide (NBPT) was applied at rates of 0, 1, and 2 kg ha-1, at 8, 16, and 32 day frequencies, and with or without simulated rainfall. Synthetic urine was added every two days to the manure surface. Gaseous ammonia was trapped by bubbling through a sulfuric acid solution using a vacuum system and analyzed for nitrogen using automated procedures. NBPT applied every 8 days was most effective, with the 1 and 2 kg NBPT ha-1 treatments resulting in 49% to 69% reduction in ammonia emission rates, respectively. The 8-day, 1 kg NBPT ha-1 treatments had the most promising benefit/cost ratios of 0.48 to 0.60. Simulated rainfall reduced the ammonia emission rates from 1% to 25% as compared to the non-rainfall treatments, although the differences were not statistically different. The use of NBPT for reducing ammonia emissions looks promising; however, possible buildup of urea in the pen surface may require a higher NBPT application rate with time

Polyherbal formulation conjugated to gold nanoparticles induced ferroptosis in drug-resistant breast cancer stem cells through ferritin degradation

Aim: Due to their minimal side effects, the anti-cancer properties of the polyherbal formulation are being investigated. However, due to their low absorption potential, the administration of polyherbal formulations is restricted. Loading the polyherbal formulation into gold nanoparticles enhances the bioavailability of the polyherbal formulation (PHF) accompanied by reducing the concentration of doxorubicin (dox). Ferroptosis is one of the novel pathways that specifically target cancer stem cells due to high ferritin levels. Hence, in the present study, we conjugated polyherbal formulation with gold nanoparticles and studied its effect on inducing ferroptosis in drug-resistant breast cancer cell lines.Materials and methods: PHF and dox conjugated to gold nanoparticles were characterized using FTIR, UV-Vis spectrophotometer, DLS, particle size analyzer, and XRD. The drug entrapment and efficiency studies were performed to assess the biodegradable potential of the synthesized gold nanoparticles. Paclitaxel-resistant breast cancer stem cells were generated, and an MTT assay was performed to evaluate the cytotoxicity potential of AuNP-PHF and AuNP-dox. Scratch assay and clonogenic assay were performed to assess the migration and proliferation of the cells after treatment with chosen drug combinations. The ability of PHF and dox conjugated to gold nanoparticles to induce ferritinophagy was evaluated by RT-PCR. Finally, image analysis was performed to check apoptosis and cellular ROS using inverted fluorescent microscope. The ability to induce cell cycle arrest was assessed by cell cycle analysis using flow cytometer.Results and conclusion: PHF and dox conjugated to gold nanoparticles showed high stability and showed to induce ferritin degradation in drug resistant breast cancer stem cells through ferritin degradation. AuNP-PHF in combination with low dose of AuNP-Dox nanoconjugate could be used as an effective cancer therapeutic agent, by targeting the autophagy necroptosis axis

High- but not low-intensity light leads to oxidative stress and quality loss of cold-stored baby leaf spinach

BACKGROUND: Quality management in the fresh produce industry is an important issue. Spinach is exposed to various adverse conditions (temperature, light, etc.) within the supply chain. The present experiments were conducted to investigate the effect of light conditions (dark, low-intensity light (LL) and high-intensity light (HL)) and photoperiod (6 h HL and 18 h dark) on the quality changes of cold-stored spinach. RESULTS: HL exposure resulted in oxidative stress, causing tissue damage and quality loss as evidenced by increased membrane damage and water loss. The content of total ascorbic acid was reduced under HL conditions. On the other hand, storage of spinach under LL conditions gave promising results, as nutritional quality was not reduced, while texture maintenance was improved. No significant differences, with the exception of nutritional quality, were found between spinach leaves stored under continuous (24 h) low-intensity light (30–35 µmol m−2 s−1) and their counterparts stored under the same light integral over 6 h (130–140 µmol m−2 s−1). CONCLUSION: LL extended the shelf-life of spinach. The amount of light received by the leaves was the key factor affecting produce quality. Light intensity, however, has to be low enough not to cause excess oxidative stress and lead to accelerated senescence