The Perceived Return on College Investment in Relation to Economic Expectations of Students at the University of Maryland

This paper presents the results of a survey conducted in the spring semester of 2017 of University of Maryland students. The results illustrate how University of Maryland students weigh the decision to attend college in terms of their perceived current economic situation and future expectations as well as predicted return on investment. A body of economic literature on the perception of return on investment from attending college exists already and this study hopes to add to the discussion as its results are unexpected. The results imply that the current generation of college students feels uncertain over the worthwhileness of higher education

Accounting for carbon offsets: establishing the foundation for carbon-trading markets

Tackling climate change requires reductions in current and future greenhouse gas (GHG) emissions as well as the removal of existing GHG from the atmosphere. Carbon-offset producers purport to provide such removals. But poor measurement practices and inadequate controls have led to extensive trading of instruments that do not materially reduce the supply of atmospheric GHG. To address these challenges, we apply basic financial-accounting principles to develop an accurate and auditable set of offset accounting principles. These principles complement and extend the E-liability method of accounting for GHG emissions. Having rigorous accounting for both emissions and offsets will expand market forces for impactful decarbonization

Video guide to design flexible DNA.mp4

Model file name: Video guide to design flexible DNA.mp4 Authors: Michelle E Howell, Karin van Dijk, Christine S Booth, Tomas Helikar, Brian A Couch, Rebecca L Roston This 30-minute video includes step-by-step instructions to design and 3-D print a long flexible DNA model that mimics the structure and function of DNA. The instructions are applicable for designing the model using open-source 3-D computer graphics software Blender 2.79 which is available for download at https://www.blender.org/download/. .mp4 file download (70 MB) below

Visualizing the Invisible: A Guide to Designing, Printing, and Incorporating Dynamic 3D Molecular Models to Teach Structure–Function Relationships

Understanding the intricate relationship between macromolecular structure and function represents a central goal of undergraduate biology education (1–3). In teaching complex three-dimensional (3D) concepts, instructors typically depend on static two-dimensional (2D) textbook images or computer-based visualization software, which can lead to unintended misconceptions (4–6). While chemical and molecular kits exist, these models cannot handle the size and detail of macromolecules. Consequently, students may graduate in the life sciences without understanding how structure underlies function or acquiring skills to translate between 2D and 3D molecular models (5, 7). Building on recent technological advances, 3D printing (3DP) potentiates an era in which students learn through direct interaction with dynamic 3D structural models. With 3DP, instructors have the opportunity to use tailor-made models of virtually any size molecule. For example, protein models can be designed to relate enzyme active site structures to kinetic activity. Furthermore, instructors can use diverse printing materials and accessories to demonstrate molecular properties, dynamics, and interactions (Fig. 1). In this article and supplemental guide, we present an example of how to incorporate a 3D model-based lesson on DNA supercoiling in an undergraduate biochemistry classroom and best practices for designing and printing 3D models

Visualizing the Invisible: A Guide to Designing, Printing, and Incorporating Dynamic 3D Molecular Models to Teach Structure–Function Relationships

Understanding the intricate relationship between macromolecular structure and function represents a central goal of undergraduate biology education (1–3). In teaching complex three-dimensional (3D) concepts, instructors typically depend on static two-dimensional (2D) textbook images or computer-based visualization software, which can lead to unintended misconceptions (4–6). While chemical and molecular kits exist, these models cannot handle the size and detail of macromolecules. Consequently, students may graduate in the life sciences without understanding how structure underlies function or acquiring skills to translate between 2D and 3D molecular models (5, 7)

Student Understanding of DNA Structure–Function Relationships Improves from Using 3D Learning Modules with Dynamic 3D Printed Models

Understanding the relationship between molecular structure and function represents an important goal of undergraduate life sciences. Although evidence suggests that handling physical models supports gains in student understanding of structure–function relationships, such models have not been widely implemented in biochemistry classrooms. Three-dimensional (3D) printing represents an emerging cost-effective means of producing molecular models to help students investigate structure–function concepts. We developed three interactive learning modules with dynamic 3D printed models to help biochemistry students visualize biomolecular structures and address particular misconceptions. These modules targeted specific learning objectives related to DNA and RNA structure, transcription factor-DNA interactions, and DNA supercoiling dynamics. We also designed accompanying assessments to gauge student learning. Students responded favorably to the modules and showed normalized learning gains of 49% with respect to their ability to understand and relate molecular structures to biochemical functions. By incorporating accurate 3D printed structures, these modules represent a novel advance in instructional design for biomolecular visualization. We provide instructors with the materials necessary to incorporate each module in the classroom, including instructions for acquiring and distributing the models, activities, and assessments. 9 supplemental files attached (below

Using the no-signaling condition for constraining the nonidealness of a Stern-Gerlach setup

On the basis of a variant of the EPR-Bohm example, we show that the no-signaling condition can be employed as a useful tool for deriving a constraint on a suitably defined measure of the `nonidealness' of a Stern-Gerlach(SG) setup. In this demonstration, a key ingredient is provided by the characteristics of the exact solution of the time-dependent Schroedinger equation as applied to a most general SG setup

Validação de método analítico para quantificação de interferentes endócrinos em águas residuárias após tratamento secundário.

Interferentes endócrinos são substâncias que estão cada vez mais presentes no meio ambiente, especialmente nos corpos hídricos, que podem causar câncer em seres humanos e animais, mutagenicidade nos órgãos reprodutores das espécies animais presentes na biota aquática, esterilidade em homens, entre outros efeitos adversos à saúde. Constructed wetlands são métodos alternativos de tratamento de água e efluentes, que se baseiam na retirada de poluentes pelas macrófitas aquáticas e pelo biofilme formado nas raízes das plantas fixadas ao meio suporte, simulando assim os sistemas naturais de tratamento. Eles têm como vantagem o baixo custo de implantação e manutenção, economia de energia elétrica durante seu funcionamento, além de serem eficientes na remoção de poluentes. Constructed wetlands foram citados como um eficiente método de remoção de pesticidas levemente hidrofóbicos. Neste contexto, devido ao fato de estrogênios serem substâncias levemente hidrofóbicas, o presente trabalho visou desenvolver e validar uma metodologia de análise cromatográfica para determinação quantitativa dos hormônios etinilestradiol (EE2) e levonorgestrel (LEV), e do composto químico bisfenol A (BPA) em águas residuárias após tratamento secundário, com o intuito de analisar esses compostos no afluente e efluente de uma wetland construída em escala laboratorial

Avaliação de um sistema de leito cultivado com recirculação para piscicultura.

Resumo: O presente estudo teve como objetivo avaliar a eficiência de leitos cultivados de fluxo subsuperficial no tratamento do efluente de piscicultura da tilápia-do-nilo (Oreochromis niloticus) em escala piloto, com ciclo fechado de água. Para tanto, foi construído um sistema de leitos cultivados composto por três unidades com os seguintes tipos de meio suporte: brita, argila expandida e uma mistura homogênea de ambos os substratos, denominada MIX. Estes meios suportes foram avaliados com e sem a presença da planta vetiver (Chrysopogon zizanioides). A eficiência dos leitos foi medida por avaliações de parâmetros físicoquímicos da água bruta e tratada, além do desempenho da planta vetiver no tratamento da água. Os resultados indicam que o meio suporte composto de brita com vetiver apresentou melhor eficiência como tratamento do efluente de piscicultura considerando a avaliação da qualidade da água, principalmente para os parâmetros: pH (próximo da neutralidade - 6,55), condutividade elétrica (0,49 mS/cm), e nitrogênio total (0,086 mg/L), com maior percentual de redução após o tratamento, onde a brita em associação com o vetiver apresentou redução de 85% do nitrogênio total. Tais resultados reforçam o potencial deste sistema para uso por piscicultores, pois emprega materiais de custo relativamente baixo, porém com elevada eficiência na redução de parâmetros críticos para a piscicultura. Abstract: The present study aimed to evaluate the efficiency of subsurface flow constructed wetlands to treat effluent from fish farming of nile tilapia (Oreochromis niloticus) in pilot scale with closed water cycle. To this end, it set up a system of constructed wetlands consisting of three types of support media: gravel, expanded clay and a homogeneous mixture of both substrates, called MIX. These support media were tested with and without the association with the plant vetiver (Chrysopogon zizanioides). The performance of the beds was measured by assessments of physical-chemical parameters of effluent and treated water, besides the performance of the vetiver plant in water filtration. The results indicate that the gravel bed associated with the plant vetiver performed better for the quality of the treated water for pH (closer to neutrality ? 6,55), electric conductivity (0,49 mS/cm) and total nitrogen (0,086 mg/L) (highest percentage reduction after treatment). The gravel in association with vetiver showed a reduction of 85% of the total nitrogen. These results reinforce the potential of this system for use by fish farmers, since it uses materials of relatively low cost but with high efficiency in the reduction of critical parameters for fish farming.bitstream/item/160850/1/BP-71-Mariana.pd

Catecholaminergic polymorphic ventricular tachycardia patients with multiple genetic variants in the PACES CPVT Registry.

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is often a life-threatening arrhythmia disorder with variable penetrance and expressivity. Little is known about the incidence or outcomes of CPVT patients with ≥2 variants. METHODS: The phenotypes, genotypes and outcomes of patients in the Pediatric and Congenital Electrophysiology Society CPVT Registry with ≥2 variants in genes linked to CPVT were ascertained. The American College of Medical Genetics & Genomics (ACMG) criteria and structural mapping were used to predict the pathogenicity of variants (3D model of pig RyR2 in open-state). RESULTS: Among 237 CPVT subjects, 193 (81%) had genetic testing. Fifteen patients (8%) with a median age of 9 years (IQR 5-12) had ≥2 variants. Sudden cardiac arrest occurred in 11 children (73%), although none died during a median follow-up of 4.3 years (IQR 2.5-6.1). Thirteen patients (80%) had at least two RYR2 variants, while the remaining two patients had RYR2 variants plus variants in other CPVT-linked genes. Among all variants identified, re-classification of the commercial laboratory interpretation using ACMG criteria led to the upgrade from variant of unknown significance (VUS) to pathogenic/likely pathogenic (P/LP) for 5 variants, and downgrade from P/LP to VUS for 6 variants. For RYR2 variants, 3D mapping using the RyR2 model suggested that 2 VUS by ACMG criteria were P/LP, while 2 variants were downgraded to likely benign. CONCLUSIONS: This severely affected cohort demonstrates that a minority of CPVT cases are related to ≥2 variants, which may have implications on family-based genetic counselling. While multi-variant CPVT patients were at high-risk for sudden cardiac arrest, there are insufficient data to conclude that this genetic phenomenon has prognostic implications at present. Further research is needed to determine the significance and generalizability of this observation. This study also shows that a rigorous approach to variant re-classification using the ACMG criteria and 3D mapping is important in reaching an accurate diagnosis, especially in the multi-variant population