New York City\u27s Drinking Water - Champagne or Beer?

Every day millions of New Yorkers drink the water from the reservoirs of the Hudson Valley. The water from these reservoirs, however, is dangerously contaminated with pathogens such as giardia and cryptosporidium. The New York City Department of Environmental Protection has undertaken measures to correct this problem and prevent further contamination by proposing revised watershed regulations. These proposed regulations, in effect, regulate the way that upstate landowners, whose property is located in a watershed, may use their land. Although the purpose of the proposed regulations is to protect the watersheds, the source of the New York City drinking water, it can only be achieved at the expense of regulating upstate landowners. This article explores the proposed regulations and potential effects it may have on the upstate landowners

Congenital Chagas Disease in the United States: Cost Savings Through Maternal Screening

Chagas disease, caused by Trypanosoma cruzi, is transmitted by insect vectors through transfusions, transplants, insect feces in food, and from mother to child during gestation. Congenital infection could perpetuate Chagas disease indefinitely, even in countries without vector transmission. An estimated 30% of infected persons will develop lifelong, potentially fatal, cardiac or digestive complications. Treatment of infants with benznidazole is highly efficacious in eliminating infection. This work evaluates the costs of maternal screening and infant testing and treatment of Chagas disease in the United States. We constructed a decision-analytic model to find the lower cost option, comparing costs of testing and treatment, as needed, for mothers and infants with the lifetime societal costs without testing and the consequent morbidity and mortality due to lack of treatment or late treatment. We found that maternal screening, infant testing, and treatment of Chagas disease in the United States are cost saving for all rates of congenital transmission greater than 0.001% and all levels of maternal prevalence above 0.06% compared with no screening program. Newly approved diagnostics make universal screening cost saving with maternal prevalence as low as 0.008%. The present value of lifetime societal savings due to screening and treatment is about $634 million saved for every birth year cohort. The benefits of universal screening for T. cruzi as part of routine prenatal testing far outweigh the program costs for all U.S. births

An Introduction to Inquiry Labs in Physics

AP Physics 1 is a new course for the 2014-2015 school year and the emphasis on inquiry-based laboratory experience will be new for our students, primarily juniors. Historically, our juniors have taken PreAP physics where they learn to use mathematics and graphs to model data and then learn a method to communicate their findings in a lab report format. Inquiry labs have been introduced primarily in AP Physics B, or senior level classes. Feedback from our AP Physics B classes indicates a need for more guidance on writing procedures, developing analysis methods, and ultimately posing questions that can be tested in the lab. Thus, we plan to begin the year in AP Physics 1 with two weeks dedicated to helping students develop procedure writing and data analysis skills that we will build throughout the year. By the end of the unit, we expect students to author procedures that can be followed by peers within the same class, and we expect them to increase their facility with the use of multiple modes for communicating and analyzing motion including observations, diagrams, verbal descriptions, graphs, and mathematical models

Long-Term Opinion Distributions of an Opinion Formation Model with Averaging Behavior

Sociophysics utilizes mathematical tools from physics to study social phenomena. In particular, interactions between individuals can impact emerging trends in the opinions of a population as a whole. This research focuses on the long-term opinion distributions of a population of individuals who can influence one another through pairwise interactions, where one individual modifies their opinion to be more in line with their neighbor. Interactions are governed by a social network, where friends on the network interact while strangers do not. We introduce a new model for opinion formation with averaging behavior where the opinion of an individual at any time t is an integer between −k and k. For example, an opinion of k could indicate a heavily republican opinion and −k a heavily democratic opinion. As the process evolves in time, interactions between neighbors x and y in the social network result in person x updating her opinion to be one step closer to the opinion of person y. We first consider the scenario where everyone in the social network is friends with everyone else. For k = 1 we compute explicitly the long-term opinion distribution via differential equations. For values of k > 1, we solve for the long-term distribution numerically using Runge-Kutta. We then compute the long-term opinion distribution via simulation, in the more general social network scenario

Illuminating the Heterotropic Communication of the Pair-wise Interactions in Phosphofructokinase from Bacillus stearothermophilus

The number of allosteric sites and active sites in phosphofructokinase from Bacillus stearothermophilus create an intricate network of communication within the enzyme. With thermodynamic linkage analysis, the overall allosteric communication can be quantified. This value, however, represents an average contribution for all the interactions involved. The recent development of a hybrid strategy has allowed for the quantification of single interactions, both heterotropic and homotropic. Focusing on the heterotropic interactions whose inhibition is entropy-driven, residues and regions within the enzyme can now be identified to further characterize each specific interaction using the hybrid strategy. Among the many components of entropy, the hybrid strategy has now allowed for the strategic placement of a reporter of side chain dynamics to identify conformational differences between the four ligand bound enzyme species of a single heterotropic interaction. In this study, a combination of these approaches was used in the methodology including constructing hybrids to isolate a single heterotropic interaction along with single tryptophan reporter. Site directed mutagenesis combined with the hybrid strategy was also implemented to directly assess the role of a single residue in the communication path of a single interaction. The region surrounding the allosteric site with the nearest active site has been implicated to be significant in transmitting the allosteric signal. In addition two single residues, T158 and D59, within this region have been identified to potentially contribute to the inhibition of this same interaction. An additional residue, G184, located outside this local region has also been identified as possibly having a significant role in the transmission of the inhibitory signal of a unique heterotropic interaction. The implications of this study have led to the initial identification of residues involved in the 22A route of allosteric communication of a single active site and allosteric site. This allosteric communication occurs to allow the enzyme to compensate for the binding of both ligands. With the location of these residues implicated to be involved in the communication of this isolated interaction, this compensation is not contained within a confined region but is however felt throughout the single subunit

Measurement of Premorbid Intellectual Ability in Brain-Injured Individuals

Clinical Psycholog