854 research outputs found
EC87-115 Breeding and Management Improve Quality of Switchgrass Pasture
Extension circular 87-115 is about breeding and management improves quality of switchgrass pasture
Numerical Testing of The Rare Earth Hypothesis using Monte Carlo Realisation Techniques
The Search for Extraterrestrial Intelligence (SETI) has thus far failed to
provide a convincing detection of intelligent life. In the wake of this null
signal, many "contact pessimistic" hypotheses have been formulated, the most
famous of which is the Rare Earth Hypothesis. It postulates that although
terrestrial planets may be common, the exact environmental conditions that
Earth enjoys are rare, perhaps unique. As a result, simple microbial life may
be common, but complex metazoans (and hence intelligence) will be rare. This
paper uses Monte Carlo Realisation Techniques to investigate the Rare Earth
Hypothesis, in particular the environmental criteria considered imperative to
the existence of intelligence on Earth.
By comparing with a less restrictive, more optimistic hypothesis, the data
indicates that if the Rare Earth hypothesis is correct, intelligent
civilisation will indeed be relatively rare. Studying the separations of pairs
of civilisations shows that most intelligent civilisation pairs (ICPs) are
unconnected: that is, they will not be able to exchange signals at lightspeed
in the limited time that both are extant. However, the few ICPs that are
connected are strongly connected, being able to participate in numerous
exchanges of signals. This may provide encouragement for SETI researchers:
although the Rare Earth Hypothesis is in general a contact-pessimistic
hypothesis, it may be a "soft" or "exclusive" hypothesis, i.e. it may contain
facets that are latently contact-optimistic.Comment: 13 pages, 10 figures, accepted for publication in the International
Journal of Astrobiolog
The role of menopause and reproductive senescence in a long-lived social mammal
<p>Abstract</p> <p>Background</p> <p>Menopause is a seemingly maladaptive life-history trait that is found in many long-lived mammals. There are two competing evolutionary hypotheses for this phenomenon; in the adaptive view of menopause, the cessation of reproduction may increase the fitness of older females; in the non-adaptive view, menopause may be explained by physiological deterioration with age. The decline and eventual cessation of reproduction has been documented in a number of mammalian species, however the evolutionary cause of this trait is unknown.</p> <p>Results</p> <p>We examined a unique 30-year time series of killer whales, tracking the reproductive performance of individuals through time. Killer whales are extremely long-lived, and may have the longest documented post-reproductive lifespan of any mammal, including humans. We found no strong support for either of the adaptive hypotheses of menopause; there was little support for the presence of post-reproductive females benefitting their daughter's reproductive performance (interbirth interval and reproductive lifespan of daughters), or the number of mature recruits to the population. Oldest mothers (> 35) did appear to have a small positive impact on calf survival, suggesting that females may gain experience with age. There was mixed support for the grandmother hypothesis – grandoffspring survival probabilities were not influenced by living grandmothers, but grandmothers may positively influence survival of juveniles at a critical life stage.</p> <p>Conclusion</p> <p>Although existing data do not allow us to examine evolutionary tradeoffs between survival and reproduction for this species, we were able to examine the effect of maternal age on offspring survival. Our results are consistent with similar studies of other mammals – oldest mothers appear to be better mothers, producing calves with higher survival rates. Studies of juvenile survival in humans have reported positive benefits of grandmothers on newly weaned infants; our results indicate that 3-year old killer whales may experience a positive benefit from helpful grandmothers. While our research provides little support for menopause evolving to provide fitness benefits to mothers or grandmothers, our work supports previous research showing that menopause and long post-reproductive lifespans are not a human phenomenon.</p
Characterization of zebrafish polymerase iii promoters for the expression of short hairpin RNA interference molecules
RNA interference (RNAi) is a powerful, sequence specific, and long-lasting method of gene knockdown, and can be elicited by the expression of short-hairpin RNA (shRNA) molecules driven via polymerase III type 3 promoters from a DNA vector or transgene. To further develop RNAi as a tool in zebrafish, we have characterized the zebrafish U6 and H1 snRNA promoters and compared the efficiency of each of the promoters to express an shRNA and silence a reporter gene, relative to previously characterized U6 promoters from pufferfish, chicken, and mouse. Our results show that the zebrafish polymerase III promoters were capable of effective gene silencing in the zebrafish ZF4 cell line, but were ineffective in mammalian Vero cells. In contrast, mouse and chicken promoters were active in Vero but not ZF4 cells, highlighting the importance of homologous promoters to achieve effective silencing
Community Partnership Interprofessional Program as Pedagogy: Process Outcomes and Faculty Impressions
Background: Since 1992, East Tennessee State University (ETSU) has augmented traditional health professions curricula with community-based, experiential learning through the Community Partnership Interprofessional Rural Health Program. The program was expanded in 2005 by including more interprofessional faculty, students, and community partners. Interprofessional teams of students and faculty work with community organizations to identify health needs and assets and implement health education programs or services.Methods and Findings: Course process outcomes were compiled from a survey of section reports and presentations. Faculty impressions of being involved in the course were gathered through conducting interviews with five interprofessional faculty. From 2005–2011, community partners included individuals, groups, and organizations within seven counties in Tennessee. Forty programs and services have been implemented through the program during the past seven years. Faculty reported the main reasons for being involved are their interests in interprofessional education and working in communities. Faculty also cited 12 different types of teaching strategies (pedagogical approaches) employed through the course.Conclusions: The Community Partnership Interprofessional Rural Health Program at ETSU is a testing ground for the unique combination of communitybased learning and interprofessional health education. Study findings demonstrate how the course has benefited faculty, students, and communities
Using Super-Imposition by Translation And Rotation (SITAR) to relate pubertal growth to bone health in later life:the Medical Research Council (MRC) National Survey of Health and Development
BACKGROUND: To explore associations between pubertal growth and later bone health in a cohort with infrequent measurements, using another cohort with more frequent measurements to support the modelling, data from the Medical Research Council (MRC) National Survey of Health and Development (2-26 years, 4901/30 004 subjects/measurements) and the Avon Longitudinal Study of Parents And Children (ALSPAC) (5-20 years) (10 896/74 120) were related to National Survey of Health and Development (NSHD) bone health outcomes at 60-64 years. METHODS: NSHD data were analysed using Super-Imposition by Translation And Rotation (SITAR) growth curve analysis, either alone or jointly with ALSPAC data. Improved estimation of pubertal growth parameters of size, tempo and velocity was assessed by changes in model fit and correlations with contemporary measures of pubertal timing. Bone outcomes of radius [trabecular volumetric bone mineral density (vBMD) and diaphysis cross-sectional area (CSA)] were regressed on the SITAR parameters, adjusted for current body size. RESULTS: The NSHD SITAR parameters were better estimated in conjunction with ALSPAC, i.e. more strongly correlated with pubertal timing. Trabecular vBMD was associated with early height tempo, whereas diaphysis CSA was related to weight size, early tempo and slow velocity, the bone outcomes being around 15% higher for the better vs worse growth pattern. CONCLUSIONS: By pooling NSHD and ALSPAC data, SITAR more accurately summarized pubertal growth and weight gain in NSHD, and in turn demonstrated notable associations between pubertal timing and later bone outcomes. These associations give insight into the importance of the pubertal period for future skeletal health and osteoporosis risk
Lunch and Learn Small Discussion Groups
Mini-conversations in which attendees self-select. There will be a discussant at each table to assist in guiding the dialogues.
Alexia Hudson-Ward: Situating Our Work Within the Mission in a Liberal Arts SettingStrategies on how to strategically communicate and steward the importance of this work to the faculty and senior leaders of our institutions as a mission-centered imperative.
Laura Perrings: Educational Opportunities Provided by Rare Book SchoolLearn more about the educational opportunities provided by Rare Book School, such as the Lang Fellowship.
Ken Grossi and Ed Vermue: Building Professional CommunityWe all need our people. This dialogue will explore how one can share and support a cohort of colleagues across the disciplines to maintain this critical work.
Anne Cuyler Salsich, Megan Mitchell, and Heath Patten: Discoverability, Presentation and Promotion of Your Existing CollectionsThis session explores questions of outreach and how to present and promote your existing objects with faculty and students.
Angela Vanden Elzen: Making as Pedagogy with Makerspaces and Digital GamingWe will review the concept of making as pedagogy with makerspaces, digital projects, and exhibitions and how to engage students, faculty, and the community in this growing area
Self-reported depression symptoms in haemodialysis patients: Bi-factor structures of two common measures and their association with clinical factors
Copyright © 2018 Elsevier Inc. All rights reserved.Objective: To validate the factor structure of two common self-report depression tools in a large sample of haemodialysis (HD) patients and to examine their demographic and clinical correlates, including urine output, history of depression and transplantation. Methods: Factor structures of the Beck Depression Inventory (BDI-II) and Patient Health Questionnaire (PHQ-9) were evaluated using confirmatory factor analysis (CFA). Data was utilised from the screening phase (n = 709) of a placebo-controlled feasibility randomised control trial (RCT) of sertraline in HD patients with mild to moderate Major Depressive Disorder. Alternative factor models including bi-factor models for the BDI-II and PHQ-9 were evaluated. Coefficient omega and omega-hierarchical were calculated. Results: For both measures, bi-factor measurement models had the overall best fit to the data, with dominant general depression factors. Omega-hierarchical for the general BDI-II and PHQ-9 factors was 0.94 and 0.88 respectively. Both general factors had high reliability (coefficient omega = 0.97 and 0.94 respectively) and explained over 85% of the explained common variance within their respective models. BDI-II and PHQ-9 general depression factors were negatively associated with age and urine output and positively with a history of depression, antidepressant use within the last 3 months and a history of failed transplantation. In adjusted regression models, age, urine output and a history of depression remained significant. Conclusions: These data suggest that both the BDI-II and PHQ-9 are sufficiently unidimensional to warrant the use of a total score. Younger age, lower urine output and a history of depression appear consistent correlates of depression severity among HD patients.Peer reviewedFinal Accepted Versio
Genomic Reconstruction of an Uncultured Hydrothermal Vent Gammaproteobacterial Methanotroph (Family Methylothermaceae) Indicates Multiple Adaptations to Oxygen Limitation
Hydrothermal vents are an important contributor to marine biogeochemistry, producing large volumes of reduced fluids, gasses, and metals and housing unique, productive microbial and animal communities fueled by chemosynthesis. Methane is a common constituent of hydrothermal vent fluid and is frequently consumed at vent sites by methanotrophic bacteria that serve to control escape of this greenhouse gas into the atmosphere. Despite their ecological and geochemical importance, little is known about the ecophysiology of uncultured hydrothermal vent-associated methanotrophic bacteria. Using metagenomic binning techniques, we recovered and analyzed a near-complete genome from a novel gammaproteobacterial methanotroph (B42) associated with a white smoker chimney in the Southern Lau basin. B42 was the dominant methanotroph in the community, at ∼80x coverage, with only four others detected in the metagenome, all on low coverage contigs (7x–12x). Phylogenetic placement of B42 showed it is a member of the Methylothermaceae, a family currently represented by only one sequenced genome. Metabolic inferences based on the presence of known pathways in the genome showed that B42 possesses a branched respiratory chain with A- and B-family heme copper oxidases, cytochrome bd oxidase and a partial denitrification pathway. These genes could allow B42 to respire over a wide range of oxygen concentrations within the highly dynamic vent environment. Phylogenies of the denitrification genes revealed they are the result of separate horizontal gene transfer from other Proteobacteria and suggest that denitrification is a selective advantage in conditions where extremely low oxygen concentrations require all oxygen to be used for methane activation
Multi-pixel high-resolution three-dimensional imaging radar
A three-dimensional imaging radar operating at high frequency e.g., 670 GHz radar using low phase-noise synthesizers and a fast chirper to generate a frequency-modulated continuous-wave (FMCW) waveform, is disclosed that operates with a multiplexed beam to obtain range information simultaneously on multiple pixels of a target. A source transmit beam may be divided by a hybrid coupler into multiple transmit beams multiplexed together and directed to be reflected off a target and return as a single receive beam which is demultiplexed and processed to reveal range information of separate pixels of the target associated with each transmit beam simultaneously. The multiple transmit beams may be developed with appropriate optics to be temporally and spatially differentiated before being directed to the target. Temporal differentiation corresponds to a different intermediate frequencies separating the range information of the multiple pixels. Collinear transmit beams having differentiated polarizations may also be implemented
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