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

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

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

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

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

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