School-Based Agricultural Education Students’ Attitudes and Beliefs toward International Agricultural Concepts

The purpose of this study was to determine the attitudes and beliefs of school-based agriculture education (SBAE) students toward international agricultural concepts. This study builds on several previous studies (Conner, Greer, & Stripling, 2017; Elliot & Yanik, 2002; Heinert, Lavery, & Roberts, 2014; Radhakrishna, Leite, & Domer, 2003). To explore new geographic regions of the United States, two states, one from the Midwest and one from the Northwest, were purposively identified. A 46-item instrument that measures attitudes, beliefs, understanding, and instruction in relation to international agriculture developed by Radhakrishna et al. (2003) was administered to students in three schools representing both rural and urban areas. A total of 133 surveys were returned, for a 55.2% response rate. Overall, students held positive attitudes and beliefs toward international agricultural concepts. Students expressed a need to understand basic geography in relation to international agricultural concepts, and students strongly agreed to concepts and information necessary to understand international agricultural concepts. When historical data were synthesized with data from this study, mean scores from all five studies across all four constructs were consistently high. Future research should focus on how students develop their attitudes and beliefs about international agriculture

Genome-scale metabolic analysis of Clostridium thermocellum for bioethanol production

<p>Abstract</p> <p>Background</p> <p>Microorganisms possess diverse metabolic capabilities that can potentially be leveraged for efficient production of biofuels. <it>Clostridium thermocellum </it>(ATCC 27405) is a thermophilic anaerobe that is both cellulolytic and ethanologenic, meaning that it can directly use the plant sugar, cellulose, and biochemically convert it to ethanol. A major challenge in using microorganisms for chemical production is the need to modify the organism to increase production efficiency. The process of properly engineering an organism is typically arduous.</p> <p>Results</p> <p>Here we present a genome-scale model of <it>C. thermocellum </it>metabolism, <it>i</it>SR432, for the purpose of establishing a computational tool to study the metabolic network of <it>C. thermocellum </it>and facilitate efforts to engineer <it>C. thermocellum </it>for biofuel production. The model consists of 577 reactions involving 525 intracellular metabolites, 432 genes, and a proteomic-based representation of a cellulosome. The process of constructing this metabolic model led to suggested annotation refinements for 27 genes and identification of areas of metabolism requiring further study. The accuracy of the <it>i</it>SR432 model was tested using experimental growth and by-product secretion data for growth on cellobiose and fructose. Analysis using this model captures the relationship between the reduction-oxidation state of the cell and ethanol secretion and allowed for prediction of gene deletions and environmental conditions that would increase ethanol production.</p> <p>Conclusions</p> <p>By incorporating genomic sequence data, network topology, and experimental measurements of enzyme activities and metabolite fluxes, we have generated a model that is reasonably accurate at predicting the cellular phenotype of <it>C. thermocellum </it>and establish a strong foundation for rational strain design. In addition, we are able to draw some important conclusions regarding the underlying metabolic mechanisms for observed behaviors of <it>C. thermocellum </it>and highlight remaining gaps in the existing genome annotations.</p

Trinidad Food Producers’ Training Needs for Food Security and Implications for Extension

The purpose of this study was to explore farmers’ knowledge of food security issues in Trinidad. Such information can be used to develop appropriate extension training interventions. Using a Borich (1980) methodology, a total of 300 agricultural producers in Trinidad were surveyed with an instrument that consisted of two parts: (a) personal demographic and farm related questions, and (b) indicators of knowledge and importance of 27 food security issues derived from The National Food Production Action Plan 2012 – 2015. Overall, the top five issues identified by producers were: (a) the incentive program that is focused on outputs; (b) research and development for both livestock and crop farmers; (c) partnerships between public sector agencies, research institutions, and the private sector to provide suitable capacity to deliver all food production programs; (d) postharvest technologies that create employment opportunities, increase returns to farmers, improve food quality, and ensure food safety; and (e) and technology packages (of information) to help farmers improve yield, quality, and availability. All 27 food security issues varied in at least one of the categories assessed: 22 issues varied by location; 18 issues varied by farm type; 5 issues varied by farming status; and 19 issues varied by education level of the farmer. These results can guide extension programming in Trinidad and also be informative for policy makers

Gap Detection for Genome-Scale Constraint-Based Models

Constraint-based metabolic models are currently the most comprehensive system-wide models of cellular metabolism. Several challenges arise when building an in silico constraint-based model of an organism that need to be addressed before flux balance analysis (FBA) can be applied for simulations. An algorithm called FBA-Gap is presented here that aids the construction of a working model based on plausible modifications to a given list of reactions that are known to occur in the organism. When applied to a working model, the algorithm gives a hypothesis concerning a minimal medium for sustaining the cell in culture. The utility of the algorithm is demonstrated in creating a new model organism and is applied to four existing working models for generating hypotheses about culture media. In modifying a partial metabolic reconstruction so that biomass may be produced using FBA, the proposed method is more efficient than a previously proposed method in that fewer new reactions are added to complete the model. The proposed method is also more accurate than other approaches in that only biologically plausible reactions and exchange reactions are used

Proteomic and network analysis characterize stage-specific metabolism in Trypanosoma cruzi

<p>Abstract</p> <p>Background</p> <p><it>Trypanosoma cruzi </it>is a Kinetoplastid parasite of humans and is the cause of Chagas disease, a potentially lethal condition affecting the cardiovascular, gastrointestinal, and nervous systems of the human host. Constraint-based modeling has emerged in the last decade as a useful approach to integrating genomic and other high-throughput data sets with more traditional, experimental data acquired through decades of research and published in the literature.</p> <p>Results</p> <p>We present a validated, constraint-based model of the core metabolism of <it>Trypanosoma cruzi </it>strain CL Brener. The model includes four compartments (extracellular space, cytosol, mitochondrion, glycosome), 51 transport reactions, and 93 metabolic reactions covering carbohydrate, amino acid, and energy metabolism. In addition, we make use of several replicate high-throughput proteomic data sets to specifically examine metabolism of the morphological form of <it>T. cruzi </it>in the insect gut (epimastigote stage).</p> <p>Conclusion</p> <p>This work demonstrates the utility of constraint-based models for integrating various sources of data (e.g., genomics, primary biochemical literature, proteomics) to generate testable hypotheses. This model represents an approach for the systematic study of <it>T. cruzi </it>metabolism under a wide range of conditions and perturbations, and should eventually aid in the identification of urgently needed novel chemotherapeutic targets.</p

A Bell Inequality Analog in Quantum Measure Theory

One obtains Bell's inequalities if one posits a hypothetical joint probability distribution, or {\it measure}, whose marginals yield the probabilities produced by the spin measurements in question. The existence of a joint measure is in turn equivalent to a certain causality condition known as ``screening off''. We show that if one assumes, more generally, a joint {\it quantal measure}, or ``decoherence functional'', one obtains instead an analogous inequality weaker by a factor of $\sqrt{2}$. The proof of this ``Tsirel'son inequality'' is geometrical and rests on the possibility of associating a Hilbert space to any strongly positive quantal measure. These results lead both to a {\it question}: ``Does a joint measure follow from some quantal analog of `screening off'?'', and to the {\it observation} that non-contextual hidden variables are viable in histories-based quantum mechanics, even if they are excluded classically.Comment: 38 pages, TeX. Several changes and added comments to bring out the meaning more clearly. Minor rewording and extra acknowledgements, now closer to published versio

Transition between nuclear and quark-gluon descriptions of hadrons and light nuclei

We provide a perspective on studies aimed at observing the transition between hadronic and quark-gluonic descriptions of reactions involving light nuclei. We begin by summarizing the results for relatively simple reactions such as the pion form factor and the neutral pion transition form factor as well as that for the nucleon and end with exclusive photoreactions in our simplest nuclei. A particular focus will be on reactions involving the deuteron. It is noted that a firm understanding of these issues is essential for unraveling important structure information from processes such as deeply virtual Compton scattering as well as deeply virtual meson production. The connection to exotic phenomena such as color transparency will be discussed. A number of outstanding challenges will require new experiments at modern facilities on the horizon as well as further theoretical developments.Comment: 37 pages, 17 figures, submitted to Reports on Progress in Physic

The Vaginal Microbiome: Disease, Genetics and the Environment

The vagina is an interactive interface between the host and the environment. Its surface is covered by a protective epithelium colonized by bacteria and other microorganisms. The ectocervix is nonsterile, whereas the endocervix and the upper genital tract are assumed to be sterile in healthy women. Therefore, the cervix serves a pivotal role as a gatekeeper to protect the upper genital tract from microbial invasion and subsequent reproductive pathology. Microorganisms that cross this barrier can cause preterm labor, pelvic inflammatory disease, and other gynecologic and reproductive disorders. Homeostasis of the microbiome in the vagina and ectocervix plays a paramount role in reproductive health. Depending on its composition, the microbiome may protect the vagina from infectious or non-infectious diseases, or it may enhance its susceptibility to them. Because of the nature of this organ, and the fact that it is continuously colonized by bacteria from birth to death, it is virtually certain that this rich environment evolved in concert with its microbial flora. Specific interactions dictated by the genetics of both the host and microbes are likely responsible for maintaining both the environment and the microbiome. However, the genetic basis of these interactions in both the host and the bacterial colonizers is currently unknown. _Lactobacillus_ species are associated with vaginal health, but the role of these species in the maintenance of health is not yet well defined. Similarly, other species, including those representing minor components of the overall flora, undoubtedly influence the ability of potential pathogens to thrive and cause disease. Gross alterations in the vaginal microbiome are frequently observed in women with bacterial vaginosis, but the exact etiology of this disorder is still unknown. There are also implications for vaginal flora in non-infectious conditions such as pregnancy, pre-term labor and birth, and possibly fertility and other aspects of women&#x2019;s health. Conversely, the role of environmental factors in the maintenance of a healthy vaginal microbiome is largely unknown. To explore these issues, we have proposed to address the following questions:&#xd;&#xa;&#xd;&#xa;*1.&#x9;Do the genes of the host contribute to the composition of the vaginal microbiome?* We hypothesize that genes of both host and bacteria have important impacts on the vaginal microbiome. We are addressing this question by examining the vaginal microbiomes of mono- and dizygotic twin pairs selected from the over 170,000 twin pairs in the Mid-Atlantic Twin Registry (MATR). Subsequent studies, beyond the scope of the current project, may investigate which host genes impact the microbial flora and how they do so.&#xd;&#xa;*2.&#x9;What changes in the microbiome are associated with common non-infectious pathological states of the host?* We hypothesize that altered physiological (e.g., pregnancy) and pathologic (e.g., immune suppression) conditions, or environmental exposures (e.g., antibiotics) predictably alter the vaginal microbiome. Conversely, certain vaginal microbiome characteristics are thought to contribute to a woman&#x2019;s risk for outcomes such as preterm delivery. We are addressing this question by recruiting study participants from the ~40,000 annual clinical visits to women&#x2019;s clinics of the VCU Health System.&#xd;&#xa;*3.&#x9;What changes in the vaginal microbiome are associated with relevant infectious diseases and conditions?* We hypothesize that susceptibility to infectious disease (e.g. HPV, _Chlamydia_ infection, vaginitis, vaginosis, etc.) is impacted by the vaginal microbiome. In turn, these infectious conditions clearly can affect the ability of other bacteria to colonize and cause pathology. Again, we are exploring these issues by recruiting participants from visitors to women&#x2019;s clinics in the VCU Health System.&#xd;&#xa;&#xd;&#xa;Three kinds of sequence data are generated in this project: i) rDNA sequences from vaginal microbes; ii) whole metagenome shotgun sequences from vaginal samples; and iii) whole genome shotgun sequences of bacterial clones selected from vaginal samples. The study includes samples from three vaginal sites: mid-vaginal, cervical, and introital. The data sets also include buccal and perianal samples from all twin participants. Samples from these additional sites are used to test the hypothesis of a per continuum spread of bacteria in relation to vaginal health. An extended set of clinical metadata associated with these sequences are deposited with dbGAP. We have currently collected over 4,400 samples from ~100 twins and over 450 clinical participants. We have analyzed and deposited data for 480 rDNA samples, eight whole metagenome shotgun samples, and over 50 complete bacterial genomes. These data are available to accredited investigators according to NIH and Human Microbiome Project (HMP) guidelines. The bacterial clones are deposited in the Biodefense and Emerging Infections Research Resources Repository (&#x22;http://www.beiresources.org/&#x22;:http://www.beiresources.org/). &#xd;&#xa;&#xd;&#xa;In addition to the extensive sequence data obtained in this study, we are collecting metadata associated with each of the study participants. Thus, participants are asked to complete an extensive health history questionnaire at the time samples are collected. Selected clinical data associated with the visit are also obtained, and relevant information is collected from the medical records when available. This data is maintained securely in a HIPAA-compliant data system as required by VCU&#x2019;s Institutional Review Board (IRB). The preponderance of these data (i.e., that judged appropriate by NIH staff and VCU&#x2019;s IRB are deposited at dbGAP (&#x22;http://www.ncbi.nlm.nih.gov/gap&#x22;:http://www.ncbi.nlm.nih.gov/gap). Selected fields of this data have been identified by NIH staff as &#x2018;too sensitive&#x2019; and are not available in dbGAP. Individuals requiring access to these data fields are asked to contact the PI of this project or NIH Program Staff. &#xd;&#xa

Nutritional supplements and infection in the elderly: why do the findings conflict?

BACKGROUND: Most of the randomized placebo-controlled trials that have examined the clinical effects of multivitamin-mineral supplements on infection in the elderly have shown no significant effect. The exceptions are three such trials, all using a supplement with the same composition, and all claiming dramatic benefits: a frequently cited study published in 1992, which reported a 50% reduction in the number of days of infection (NDI), and two 2002 replication studies. Questions have been raised about the 1992 report; a second report in 2001 based on the same trial, but describing effects of the supplement on cognitive functions, has been retracted by Nutrition. The primary purpose of the present paper is to evaluate the claims about the effects of supplements on NDI in the two replication reports. METHODS: Examination of internal consistency (outcomes of statistical tests versus reported data); comparison of variability of NDI across individuals in these two reports with variability in other trials; estimation of the probability of achieving the reported close agreement with the original finding. RESULTS: The standard deviations of NDI and levels of statistical significance reported are profoundly inconsistent. The reported standard deviations of NDI are consistently below what other studies have found. The reported percent reductions in NDI agree too closely with the original study. CONCLUSION: The claims of reduced NDI in the two replication reports should be questioned, which also adds to concerns about the 1992 study. It follows that there is currently no trustworthy evidence from randomized placebo-controlled clinical trials that favors the use of vitamin-mineral supplements to reduce infection in the elderly