Isolating Factors that Influence Grazing Patterns in Dairy Cattle

Factors influencing grazing patterns were identified utilizing remote sensors on lactating Holstein and Brown Swiss dairy cattle in order to recommend efficient management techniques to dairy farmers. Over the course of three separate two week periods- one in the spring, summer and fall- data was collected on the dairy herd at Eastern Kentucky University’s Meadowbrook Farm. Approximately 18 cows were used each trial period; half being Brown Swiss and the other half being Holstein. Data was collected via CowManager ear tags, which tracked the five behavioral patterns of eating, ruminating, high, medium, and no activity. These activities served as dependent variables for this study. The independent variables included breed, temperature, humidity, month in lactation, pounds of milk produced, percent fat, percent protein and somatic cell count. This raw data was statistically evaluated using multivariate multiple linear regression analyses. Statistical analysis revealed that breed, season, temperature, stage of lactation and pounds of milk produced impact grazing patterns. Therefore, it is recommended that Brown Swiss cows be allowed to graze longer than Holsteins because of their superior utilization of forage as a low cost feed source. It is also recommended that dairy herds be allowed to graze longer in the summer and fall than in the spring. However, it is probably a more accurate recommendation to graze during hours of no direct sunlight, such as early morning and evening, rather than grazing midday. In addition, it is suggested that individual farm managers evaluate their net income per cow relative to feed costs

Global Climate Niche Estimates for Bioenergy Crops and Invasive Species of Agronomic Origin: Potential Problems and Opportunities

The global push towards a more biomass-based energy sector is ramping up efforts to adopt regionally appropriate high-yielding crops. As potential bioenergy crops are being moved around the world an assessment of the climatic suitability would be a prudent first step in identifying suitable areas of productivity and risk. Additionally, this assessment also provides a necessary step in evaluating the invasive potential of bioenergy crops, which present a possible negative externality to the bioeconomy. Therefore, we provide the first global climate niche assessment for the major graminaceous (9), herbaceous (3), and woody (4) bioenergy crops. Additionally, we contrast these with climate niche assessments for North American invasive species that were originally introduced for agronomic purposes as examples of well-intentioned introductions gone awry. With few exceptions (e.g., Saccharum officinarum, Pennisetum purpureum), the bioenergy crops exhibit broad climatic tolerance, which allows tremendous flexibility in choosing crops, especially in areas with high summer rainfall and long growing seasons (e.g., southeastern US, Amazon Basin, eastern Australia). Unsurprisingly, the invasive species of agronomic origin have very similar global climate niche profiles as the proposed bioenergy crops, also demonstrating broad climatic tolerance. The ecoregional evaluation of bioenergy crops and known invasive species demonstrates tremendous overlap at both high (EI≥30) and moderate (EI≥20) climate suitability. The southern and western US ecoregions support the greatest number of invasive species of agronomic origin, especially the Southeastern USA Plains, Mixed Woods Plains, and Mediterranean California. Many regions of the world have a suitable climate for several bioenergy crops allowing selection of agro-ecoregionally appropriate crops. This model knowingly ignores the complex biotic interactions and edaphic conditions, but provides a robust assessment of the climate niche, which is valuable for agronomists, crop developers, and regulators seeking to choose agro-ecoregionally appropriate crops while minimizing the risk of invasive species

Reviewing research priorities in weed ecology, evolution and management : a horizon scan

Weedy plants pose a major threat to food security, biodiversity, ecosystem services and consequently to human health and wellbeing. However, many currently used weed management approaches are increasingly unsustainable. To address this knowledge and practice gap, in June 2014, 35 weed and invasion ecologists, weed scientists, evolutionary biologists and social scientists convened a workshop to explore current and future perspectives and approaches in weed ecology and management. A horizon scanning exercise ranked a list of 124 pre-submitted questions to identify a priority list of 30 questions. These questions are discussed under seven themed headings that represent areas for renewed and emerging focus for the disciplines of weed research and practice. The themed areas considered the need for transdisciplinarity, increased adoption of integrated weed management and agroecological approaches, better understanding of weed evolution, climate change, weed invasiveness and finally, disciplinary challenges for weed science. Almost all the challenges identified rested on the need for continued efforts to diversify and integrate agroecological, socio-economic and technological approaches in weed management. These challenges are not newly conceived, though their continued prominence as research priorities highlights an ongoing intransigence that must be addressed through a more system-oriented and transdisciplinary research agenda that seeks an embedded integration of public and private research approaches. This horizon scanning exercise thus set out the building blocks needed for future weed management research and practice; however, the challenge ahead is to identify effective ways in which sufficient research and implementation efforts can be directed towards these needs

Surrogacy in invasion research and management: inferring “impact” from “invasiveness”

Biological invasions are widely accepted drivers of biodiversity decline, yet the ecological impacts of invaders in many contexts remain largely unmeasured. Consequently, other measures of a species invasion (e.g. local abundance) are regularly used as surrogates (or ‘proxies’) to infer impact on recipient ecosystems. The use of surrogates for impact represents an implicit application of ecological surrogacy in invasion science, but without the evaluation and validation of surrogate-target relationships that characterizes surrogate use in other fields. While there are practical reasons for this, there also are risks associated with not testing the accuracy, stability and certainty of surrogate-impact relationships that need to be acknowledged. Recognizing the role of surrogacy in invasion science offers previously unappreciated solutions for increasing the quantitative rigor of invasive species impact assessments that inform management decisions.ARC Laureate Fellowshi

Reflections on thirty years since the death of Steve Biko : a legacy revisited

Papers presented at the Forum for Religious Dialogue Symposium of the Research Institute for Theology and Religion held at the University of South Africa, Pretoria, 23-24 August 2008Research Institute for Theology and Religio

The role of higher education

Papers presented at the Forum for Religious Dialogue Symposium of the Research Institute for Theology and Religion held at the University of South Africa, Pretoria, 26-27 March 2009.Research Institute for Theology and Religio

Susceptibility of Pseudomonas aeruginosa Biofilm to Alpha-Helical Peptides: D-enantiomer of LL-37

Pseudomonas aeruginosa is a highly versatile opportunistic pathogen and its ability to produce biofilms is a direct impediment to the healing of wounds and recovery from infection. Interest in anti-microbial peptides (AMPs) has grown due to their potential therapeutic applications and their possible use against antibiotic resistant bacteria. LL-37 is the only cathelicidin expressed by humans. In this study, we tested LL-37 and the effect of a protease-resistant LL-37 peptide mimetic, the peptide enantiomer D-LL-37, for anti-microbial and anti-biofilm activity against P. aeruginosa. Both forms of the peptide were equally effective as AMPs with similar killing kinetics. Circular dichroism spectra were obtained to demonstrate the chirality of D- and L-LL-37, and the trypsin resistance of D-LL-37 was confirmed. The helical cathelicidin from the cobra Naja atra (NA-CATH), and synthetic peptide variations (ATRA-1, ATRA-2, NA-CATH:ATRA1-ATRA1) were also tested. Although the cobra cathelicidin and related peptides had strong anti-microbial activity, those tested did not inhibit Pseudomonas biofilm formation, neither did control peptides. Both D- and L-LL-37 inhibited the attachment of Pseudomonas to a 96-well plate and decreased the amount of pre-formed (established) biofilm. D-LL-37 is able to promote Pseudomonas motility and decrease biofilm formation by altering the rate of twitching as well as by downregulating the expression of the biofilm-related genes, rhlA and rhlB, similar to L-LL-37. Both L- and D-LL-37 protected Galleria mellonella in vivo against Pseudomonas infection, while NA-CATH:ATRA1-ATRA1 peptide did not. This study demonstrates the ability and equivalence of D-LL-37 compared to L-LL-37 to promote bacterial twitching motility and inhibit biofilm formation, and protect against in vivo infection, and suggests that this peptide could be a critical advancement in the development of new treatments for P. aeruginosa infection

Health needs of clients as reported by medical practitioners from two districts of Sindh

Objective: To identify the major health and reproductive health problems for which people consult local medical practitioners.METHODOLOGY: Forty-one practitioners completed a self-administered questionnaire. A startified purposive sample of practitioners was selected by asking the community members from various towns and rural areas to identify practitioners who have most busy practices and are perceived as providing quality care.Results: Nine of the forty-one practitioners were females. Twenty-two were consulted mainly by women and another seventeen by an equal number of women and men. Practitioners pointed to malnutrition, malaria, gastrointestinal and respiratory tract problems as being the most common ailments. They identified menstrual problems, malnutrition among pregnant women, burning micturition and vaginal discharge as the most common reproductive health problems of their clients. Only 16 medical practitioners said that they diagnosed someone in the last one-month as suffering from sexually transmitted infections.CONCLUSION: The survey helped in developing an understanding of health issues from provider perspective. Findings indicate a concordance between what has been revealed by previous population based studies in similar situations and to what health problems practitioners pointed as common. While a comprehensive needs-assessment requires surveys and qualitative interviews with communities, consultations with relatively fewer medical practitioners could also provide a quick and fair approximation of priority health problems in the area

Theory of Parabolic Arcs in Interstellar Scintillation Spectra

Our theory relates the secondary spectrum, the 2D power spectrum of the radio dynamic spectrum, to the scattered pulsar image in a thin scattering screen geometry. Recently discovered parabolic arcs in secondary spectra are generic features for media that scatter radiation at angles much larger than the rms scattering angle. Each point in the secondary spectrum maps particular values of differential arrival-time delay and fringe rate (or differential Doppler frequency) between pairs of components in the scattered image. Arcs correspond to a parabolic relation between these quantities through their common dependence on the angle of arrival of scattered components. Arcs appear even without consideration of the dispersive nature of the plasma. Arcs are more prominent in media with negligible inner scale and with shallow wavenumber spectra, such as the Kolmogorov spectrum, and when the scattered image is elongated along the velocity direction. The arc phenomenon can be used, therefore, to constrain the inner scale and the anisotropy of scattering irregularities for directions to nearby pulsars. Arcs are truncated by finite source size and thus provide sub micro arc sec resolution for probing emission regions in pulsars and compact active galactic nuclei. Multiple arcs sometimes seen signify two or more discrete scattering screens along the propagation path, and small arclets oriented oppositely to the main arc persisting for long durations indicate the occurrence of long-term multiple images from the scattering screen.Comment: 22 pages, 11 figures, submitted to the Astrophysical Journa

Cavitation in soft matter

Cavitation is the sudden, unstable expansion of a void or bubble within a liquid or solid subjected to a negative hydrostatic stress. Cavitation rheology is a field emerging from the development of a suite of materials characterization, damage quantification, and therapeutic techniques that exploit the physical principles of cavitation. Cavitation rheology is inherently complex and broad in scope with wide-ranging applications in the biology, chemistry, materials, and mechanics communities. This perspective aims to drive collaboration among these communities and guide discussion by defining a common core of high-priority goals while highlighting emerging opportunities in the field of cavitation rheology. A brief overview of the mechanics and dynamics of cavitation in soft matter is presented. This overview is followed by a discussion of the overarching goals of cavitation rheology and an overview of common experimental techniques. The larger unmet needs and challenges of cavitation in soft matter are then presented alongside specific opportunities for researchers from different disciplines to contribute to the field