2,316 research outputs found

    A simple algorithm for the Kohn-Sham inversion problem applicable to general target densities

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    A simple algorithm for the Kohn-Sham inversion problem is presented. The method is found to converge toward a nearby v-representable Kohn-Sham density irrespective of the fact whether the initial target density has been v-representable or not. For the proposed procedure, the target density can be of general nature. The algorithm can handle Hartree-Fock and post-Hartree-Fock, spin-unpolarized and polarized states equally well. Additionally, experimental densities and even general gedanken densities can be treated. The algorithm is easy to implement and does not require an additional procedure to adjust eigenvalues

    Changes in the milk metabolome of the Giant Panda (Ailuropoda melanoleuca) with time after birth: three phases in early lactation and progressive individual differences

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    Ursids (bears) in general, and giant pandas in particular, are highly altricial at birth. The components of bear milks and their changes with time may be uniquely adapted to nourish relatively immature neonates, protect them from pathogens, and support the maturation of neonatal digestive physiology. Serial milk samples collected from three giant pandas in early lactation were subjected to untargeted metabolite profiling and multivariate analysis. Changes in milk metabolites with time after birth were analysed by Principal Component Analysis, Hierarchical Cluster Analysis and further supported by Orthogonal Partial Least Square-Discriminant Analysis, revealing three phases of milk maturation: days 1–6 (Phase 1), days 7–20 (Phase 2), and beyond day 20 (Phase 3). While the compositions of Phase 1 milks were essentially indistinguishable among individuals, divergences emerged during the second week of lactation. OPLS regression analysis positioned against the growth rate of one cub tentatively inferred a correlation with changes in the abundance of a trisaccharide, isoglobotriose, previously observed to be a major oligosaccharide in ursid milks. Three artificial milk formulae used to feed giant panda cubs were also analysed, and were found to differ markedly in component content from natural panda milk. These findings have implications for the dependence of the ontogeny of all species of bears, and potentially other members of the Carnivora and beyond, on the complexity and sequential changes in maternal provision of micrometabolites in the immediate period after birth

    Prolonged transition time between colostrum and mature milk in a bear, the giant panda, Ailuropoda melanoleuca

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    Bears produce the most altricial neonates of any placental mammal. We hypothesized that the transition from colostrum to mature milk in bears reflects a temporal and biochemical adaptation for altricial development and immune protection. Comparison of bear milks with milks of other eutherians yielded distinctive protein profiles. Proteomic and metabolomic analysis of serial milk samples collected from six giant pandas showed a prolonged transition from colostrum to main-phase lactation over approximately 30 days. Particularly striking are the persistence or sequential appearance of adaptive and innate immune factors. The endurance of immunoglobulin G suggests an unusual duration of trans-intestinal absorption of maternal antibodies, and is potentially relevant to the underdeveloped lymphoid system of giant panda neonates. Levels of certain milk oligosaccharides known to exert anti-microbial activities and/or that are conducive to the development of neonatal gut microbiomes underwent an almost complete changeover around days 20–30 postpartum, coincident with the maturation of the protein profile. A potential metabolic marker of starvation was detected, the prominence of which may reflect the natural postpartum period of anorexia in giant panda mothers. Early lactation in giant pandas, and possibly in other ursids, appears to be adapted for the unique requirements of unusually altricial eutherian neonates

    Impacting Agriculture and Natural Resource Policy: County Commissioners’ Decision-Making Behaviors and Communication Preferences

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    Elected officials at the local, state, and national levels play key roles in shaping the agriculture and natural resources (ANR) sectors through the development and implementation of ANR policies and regulations. As such, it has become necessary for members of the ANR community to understand the policy formation process and how to communicate effectively with elected officials about ANR policies and issues. However, little research has been conducted at the local level to examine how local elected officials (LEOs) interact with information specific to ANR policies to make decisions. This study was designed to assess the communication and information-seeking preferences and behaviors of LEOs that impact their decisions about ANR issues and policies. Of the sources of communication considered by LEOs when making ANR policy decisions, respondents in this study identified communication from farmers and ranchers as having the highest impact on their decision-making. This finding supports the use of farmers and ranchers as opinion leaders in impacting ANR policies. LEOs in this study also reported they would seek factual information from multiple sources to understand the positive or negative impact of the ANR policy before voting on the ANR issue

    Changeover from signalling to energy-provisioning lipids during transition from colostrum to mature milk in the giant panda (Ailuropoda melanoleuca)

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    Among the large placental mammals, ursids give birth to the most altricial neonates with the lowest neonatal:maternal body mass ratios. This is particularly exemplified by giant pandas. To examine whether there is compensation for the provision of developmentally important nutrients that other species groups may provide in utero, we examined changes in the lipids of colostrum and milk with time after birth in giant pandas. Lipids that are developmental signals or signal precursors, and those that are fundamental to nervous system construction, such as docosahexaenoic acid (DHA) and phosphatidylserines, appear early and then fall dramatically in concentration to a baseline at 20-30 days. The dynamics of lysophosphatidic acid and eicosanoids display similar patterns, but with progressive differences between mothers. Triglycerides occur at relatively low levels initially and increase in concentration until a plateau is reached at about 30 days. These patterns indicate an early provision of signalling lipids and their precursors, particularly lipids crucial to brain, retinal and central nervous system development, followed by a changeover to lipids for energy metabolism. Thus, in giant pandas, and possibly in all bears, lactation is adapted to provisioning a highly altricial neonate to a degree that suggests equivalence to an extension of gestation

    Technically Speaking: Technical Skills Needed for Agricultural Communication Baccalaureate Graduates

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    Technically Speaking: Technical Skills Needed for Agricultural Communication Baccalaureate Graduates Abstract The purpose of this national study was to assess the perceived importance of 57 technical skills identified in previous literature, and to determine entry-level, agricultural communication graduates’ ability to perform those technical skills as perceived by agricultural communication graduates, communication industry professionals, and agricultural communication faculty members. Participants from the three evaluation groups (n = 193) identified three of the most important technical skills needed by agricultural communication graduates. These skills were communicating in written form, concise and clear writing, and communicating verbally. Graduates placed a higher importance on technical skills than the other two evaluation groups. All three evaluation groups showed some agreement on graduates’ highest ability to perform several technical skills: ability to use technology, ability to use Microsoft Word, and ability to adapt to contemporary media. A significant difference was found between the evaluation groups for the ability graduates afforded themselves in telephone etiquette, ability to use Microsoft Word, reading skills, ability to use Instagram, ability to use graphic design software, and ability to use web design software, as compared to the other two evaluation groups. Recommendations included incorporating technical skills into instruction for undergraduate students. Content should be focused in technical-skill areas identified as being of high importance: communicate in written form; communicate verbally; write concisely and clearly; and use of proper punctuation, grammar, and spelling. Faculty members could benefit from research that identifies more effective measures to evaluate technical skills attainment

    Chiral phase transition in a lattice fermion--gauge--scalar model with U(1) gauge symmetry

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    The chiral phase transition induced by a charged scalar field is investigated numerically in a lattice fermion-gauge-scalar model with U(1) gauge symmetry, proposed recently as a model for dynamical fermion mass generation. For very strong gauge coupling the transition is of second order and its scaling properties are very similar to those of the Nambu--Jona-Lasinio model. However, in the vicinity of the tricritical point at somewhat weaker coupling, where the transition changes the order, the scaling behavior is different. Therefore it is worthwhile to investigate the continuum limit of the model at this point.Comment: 20 pages, latex2e, 15 PostScript figures included, all files tared, compressed and uudecode

    Impact of Vancomycin on sarA-Mediated Biofilm Formation: Role in Persistent Endovascular Infections Due to Methicillin-Resistant Staphylococcus aureus

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    Background. Staphylococcus aureus is the most common cause of endovascular infections. The staphylococcal accessory regulator A locus (sarA) is a major virulence determinant that may potentially impact methicillin-resistant S. aureus (MRSA) persistence in such infections via its influence on biofilm formation. Methods. Two healthcare-associated MRSA isolates from patients with persistent bacteremia and 2 prototypical community-acquired MRSA strains, as well as their respective isogenic sarA mutants, were studied for in vitro biofilm formation, fibronectin-binding capacity, autolysis, and protease and nuclease activities. These assays were done in the presence or absence of sub-minimum inhibitory concentrations (MICs) of vancomycin. In addition, these strain pairs were compared for intrinsic virulence and responses to vancomycin therapy in experimental infective endocarditis, a prototypical biofilm model. Results. All sarA mutants displayed significantly reduced biofilm formation and binding to fibronectin but increased protease production in vitro, compared with their respective parental strains. Interestingly, exposure to sub-MICs of vancomycin significantly promoted biofilm formation and fibronectin-binding in parental strains but not in sarA mutants. In addition, all sarA mutants became exquisitely susceptible to vancomycin therapy, compared with their respective parental strains, in the infective endocarditis model. Conclusions. These observations suggest that sarA activation is important in persistent MRSA endovascular infection, potentially in the setting of biofilm formatio
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