Understanding the Effects of a Tannin Extract on Forage Protein Digestion in the Rumen and Abomasum Using a Dynamic Artificial Digestive System Coupled to a Digestomic Approach

Improving the use efficiency of dietary protein in ruminants is a major challenge to decrease feed supplementation and significantly decrease nitrogen (N) losses to the environment. The aim of this study was to characterize the effects of tannins on protein digestion in the rumen and in conditions simulating the abomasum, using a dynamic in vitro digestive system coupled to a digestomic approach. Three ruminally-cannulated sheep fed with alfalfa hay were infused daily with a solution of tannins, while three other sheep were infused with water (control). Standardized ruminal fluid was introduced into the digester, which simulated the transit of digesta under physicochemical conditions mimicking the abomasum in terms of pH regulation, digestive enzyme infusions and transit rate. Protein degradation in the rumen and in the simulated abomasum was analyzed by determination of fermentation end-products, and identification and quantification of peptides (Label Free Quantification) by LC-MS/MS high resolution (Orbitrap). The analysis of rumen samples showed that tannins result in a clear decrease of fermentation end-products related to protein degradation, namely ammonia (NH3) and iso-volatile fatty acids (VFA), and a greater abundance of the Rubisco, a major plant protein. In the simulated abomasal compartment, the peptidomic analysis showed that the hydrolysis intensity of Rubisco was higher in the presence of tannins compared to the control group. These results indicate that protein-tannin complexes could be dissociated in the physico-chemical conditions of the abomasum, increasing the flow of peptides to the intestine after protection of protein by tannins in the rumen

Public Purpose Recreation Marketing: A Focus on the Relationships Between the Public and Public Lands

Marketing has long had a place in the planning and management of public sector recreation. In particular, the use of market segmentation has allowed leisure providers to better understand their clients’ needs and to tailor their services to the diversity of those needs. However, the use of marketing approaches is not without controversy and is sometimes perceived to be at odds with the public service or stewardship mandates often associated with recreation management. We suggest that wholesale adoption of basic marketing principles (such as the notion of giving people exactly what they want at a great price) may be inappropriate. An alternative form, relational marketing, may be better suited to public purpose organizations. Relational marketing focuses on the development or fostering of a relationship between the public and the public agency. Thus, relational marketing focuses on building confidence in the agency’s ability to guard the short- and long-term interests of the public. For example, for land management agencies, these objectives are embedded in legislative and policy mandates to provide outstanding opportunities for recreation, while at the same time protecting and enhancing the environment. Relational marketing seems better suited to these objectives compared with transactional marketing, which is more dominant in private sector businesses. Whereas transactional marketing focuses on fostering current and continuing purchases of goods and services, relational marketing extends beyond the direct economic exchange. In the public recreation settings, the public is considered more than a current or potential customer, they are also considered an owner or shareholder of the agency. Thus, repeat purchases or customer satisfaction are not sufficient measures of success for organizations with a public service mandate. Instead, relational marketing considers the perceptions that the many different groups of the public (e.g. participants and non-participants, supporters and non-supporters) have of the agency and its actions. The research reported here conceptualizes the relationship between the public and the agency into three dimensions: social trust (the degree to which individuals perceive the agency to share their views, goals, and values); commitment (the investment, attachment, and longevity of the relationship to the agency); and social responsibility (which includes attitudes towards the goals or public purposes of the agency). A market segmentation based on these dimensions yielded distinct subpopulations of the general public. The challenge for public agencies, such as the Forest Service, is to be responsive to the different relationships the public has with the agency. Collaborative planning efforts must acknowledge and incorporate knowledge of these differences in social trust, commitment, and social responsibility. Any public action or policy change should consider how it potentially affects the varying public’s relationship with the agency and the services it provides. Managers must demonstrate stewardship, care, responsiveness, and continuing service to today’s public and future generations. Any interaction with the public (e.g., marketing) should focus on the intended public purpose which guides the agency

A comparison of the clinical relevance of thallium201 and technetium-99m-methoxyisobutyl-isonitrile for the evaluation of myocardial blood flow

Thallium-201 is at present the radiotracer of choice for the clinical evaluation of myocardial blood flow. Although different technetium-99m-isonitrile agents have been synthesised recently, only 99mTc-melhoxyisobutyl-isonitrile (99mTc_MIBI) has proved to hold promise for clinical implementation. The myocardial distribution of 201TI and 99mTc_MIBI was compared in a group of 20 patients, who underwent both 201TI single photon emission computed tomography and 99mTc_MIBI study as well as coronary angiography. The sensitivity for predicting a lesion ranged from 25% to 88% in different areas of the heart and was comparable for the two radiophannaceuticals. The specificity was > 80% tor all regions except the inferior region where a specificily ot 58% obtained by 99mTc-MIBI was better than the low specificity of 17% obtained with 201TI (P< 0,008)

Late-night simulation: Opinions of fourth- and fifth-year medical students at the University of the Free State, Bloemfontein, South Africa

Background. Sleep deprivation is a problem for medical students and practitioners due to long and late working hours, which may result in a decline in their performance in practising medicine. Objectives. To investigate whether educational practices require altering with regard to the time at which simulation classes are presented, or identify any other possible suggestions for improving the preparation of students for shift work in their profession as medical doctors as a potential solution to reduce sleep-deprivation-related adverse outcomes. Methods. In this quantitative cross-sectional study, an anonymous questionnaire was distributed to 111 fourth-year and 141 fifth-year medical students at the Faculty of Health Sciences, University of the Free State (UFS), Bloemfontein, South Africa, during the second half of 2018. The researchers interpreted the responses and the Department of Biostatistics, UFS, analysed the data. Results. The majority of the fourth-year (88.6%) and fifth-year (90.4%) student groups responded that late-night simulation classes between 01h00 and 04h00 would not be beneficial to their preparation for shift work. The motivation for negative responses was that it might worsen sleep deprivation due to time constraints in an already demanding course. The fourth-year (61.4%) and fifth-year (80.5%) student groups did not regard simulation as realistic and felt that late-night simulation training sessions would not prepare them better for future shift work. However, both groups believed ‘practice makes perfect’ and, as such, their confidence with procedures would improve as they practise more during simulation. Conclusion. The majority of students were negative towards the idea of late-night simulation classes, because of the effect it would have on their already full programme. Students are familiar with the effects of sleep deprivation and felt that late-night simulation classes would add pressure to their busy lives and worsen their sleep deprivation. Further investigation and practical testing would be required to conclude the impact of late-night simulation classes in preparation for shift work of medical doctors and the resultant effect on clinical performance

Anorectal malformations and the impact of HIV on surgical outcome

Background. Anorectal malformations (ARMs) represent a significant surgical load in South African (SA) paediatric surgical centres. Surgical treatment of ARMs may be associated with postoperative complications owing to the nature of surgical procedures necessary in the neonatal and infant period. HIV and its effect on the immune response compound postoperative surgical complications. The impact of HIV exposure and its effect on the child’s immune status, independent of the child’s HIV status, has yet to be studied in the surgical population.Objectives. To assess the incidence of complications in our population of ARM patients and to explore whether these were increased in HIV-exposed but serologically negative children compared with HIV-unexposed children.Methods. This was a prospective study of all patients presenting with ARMs to the paediatric surgery units attached to the University of the Witwatersrand, Johannesburg, SA. Specifically, exposure to an HIV-positive mother, patient HIV status and presence of surgical complications were documented. Data were analysed for the period August 2016 - September 2017.Results. A total of 50 children were included (none were excluded); 19 (38%) were HIV-exposed but none were HIV-positive, and 28 (56%) were male and 22 (44%) female. Seventy-six operative procedures were performed, with 27 operative complications. In the HIV-exposed group, 68% of patients experienced operative complications, compared with 45% in the unexposed group (p=0.1); 50% of the HIV-exposed patients who had stoma formation experienced complications, compared with 20% in the unexposed group (p=0.08).Conclusions. The incidence of postoperative infectious complications in HIV-exposed patients was higher than in HIV-unexposed patients. The incidence of postoperative complications in HIV-unexposed patients parallels that in the international literature, except in the posterior sagittal anorectoplasty groups. It remains critically important to follow stringent perioperative protocols for infection prevention and aggressively treat any infection that arises, particularly in patients born to HIV-positive mothers, regardless of the patient’s HIV status.

Dynamic Impedance of Two-Dimensional Superconducting Films Near the Superconducting Transition

The sheet impedances, Z(w,T), of several superconducting a-Mo77Ge23 films and one In/InOx film have been measured in zero field using a two-coil mutual inductance technique at frequencies from 100 Hz to 100 kHz. Z(w,T) is found to have three contributions: the inductive superfluid, renormalized by nonvortex phase fluctuations; conventional vortex-antivortex pairs, whose contribution turns on very rapidly just below the usual Kosterlitz-Thouless-Berezinskii unbinding temperature; and an anomalous contribution. The latter is predominantly resistive, persists well below the KTB temperature, and is weakly dependent on frequency down to remarkably low frequencies, at least 100 Hz. It increases with T as e-U'(T)/kT, where the activation energy, U'(T), is about half the energy to create a vortex-antivortex pair, indicating that the frequency dependence is that of individual excitations, rather than critical behavior.Comment: 10 pages, 10 figs; subm PR

Inertial Mass of a Vortex in Cuprate Superconductors

We present here a calculation of the inertial mass of a moving vortex in cuprate superconductors. This is a poorly known basic quantity of obvious interest in vortex dynamics. The motion of a vortex causes a dipolar density distortion and an associated electric field which is screened. The energy cost of the density distortion as well as the related screened electric field contribute to the vortex mass, which is small because of efficient screening. As a preliminary, we present a discussion and calculation of the vortex mass using a microscopically derivable phase-only action functional for the far region which shows that the contribution from the far region is negligible, and that most of it arises from the (small) core region of the vortex. A calculation based on a phenomenological Ginzburg-Landau functional is performed in the core region. Unfortunately such a calculation is unreliable, the reasons for it are discussed. A credible calculation of the vortex mass thus requires a fully microscopic, non-coarse grained theory. This is developed, and results are presented for a s-wave BCS like gap, with parameters appropriate to the cuprates. The mass, about 0.5 $m_e$ per layer, for magnetic field along the $c$ axis, arises from deformation of quasiparticle states bound in the core, and screening effects mentioned above. We discuss earlier results, possible extensions to d-wave symmetry, and observability of effects dependent on the inertial mass.Comment: 27 pages, Latex, 3 figures available on request, to appear in Physical Review

Tuberculosis research in South Africa over the past 30 years: From bench to bedside

The South African Medical Research Council Centre for Tuberculosis Research has a rich history of high-impact research that has influenced our understating of this hyper-epidemic which is further exacerbated by the emergence and spread of drug-resistant forms of the disease. This review aims to summarise the past 30 years of research conducted in the Centre which has influenced the way that tuberculosis (TB) is diagnosed and treated. The review includes the development of new technologies for rapid screening of people with probable TB and the repurposing of human diagnostics for wildlife conservation

A multidisciplinary study of a small, temporarily open/closed South African estuary, with particular emphasis on the influence of mouth state on the ecology of the system

In 2005/2006 a multidisciplinary research programme that included studies on the hydrodynamics, sediment dynamics, macronutrients, microalgae, macrophytes, zoobenthos, hyperbenthos, zooplankton, ichthyoplankton, fish and birds of the temporarily open/closed East Kleinemonde Estuary was conducted. Particular attention was given to the responses of the different ecosystem components to the opening and closing of the estuary mouth and how this is driven by both riverine and marine events. Using a complementary dataset of daily estuary mouth conditions spanning a 14-year period, five distinct phases of the estuary were identified, including closed (average = 90% of the days), outflow (<1%), tidal (9%) and semi-closed (<1%). The open-mouth phase is critical for the movements of a number of estuary-associated fish (e.g. Rhabdosargus holubi) and invertebrates (e.g. Scylla serrata) between the estuary and sea. The timing of this open phase has a direct influence on the ability of certain estuaryassociated fish (e.g. Lithognathus lithognathus) and invertebrates (e.g. Palaemon peringueyi) to successfully recruit into the system, with a spring opening (October/November) being regarded as optimal for most species. The type of mouth-breaching event and outflow phase is also important in terms of the subsequent salinity regime once the berm barrier forms. A deep mouth breaching following a large river flood tends to result in major tidal inputs of marine water prior to mouth closure and therefore higher salinities (15–25). Conversely, a shallow mouth breaching with reduced tidal exchange during the open phase often leads to a much lower salinity regime at the time of mouth closure (5–15). The biota, especially the submerged macrophytes, respond very differently to the above two scenarios, with Ruppia cirrhosa benefiting from the former and Potamogeton pectinatus from the latter. River flooding and the associated outflow of large volumes of water through the estuary can result in major declines in zooplankton, zoobenthos, hyperbenthos and fish populations during this phase. However, this resetting of the estuary is necessary because certain marine invertebrate and fish species are dependent on the opening of the estuary mouth in order to facilitate recruitment of larvae and post-larvae into the system from the sea. Slight increases in the numbers of certain piscivorous and resident wading bird species were recorded when the estuary mouth opened, possibly linked to increased feeding opportunities during that phase

Correlation of Mycobacterium Tuberculosis Specific and Non-Specific Quantitative Th1 T-Cell Responses with Bacillary Load in a High Burden Setting

Measures of bacillary load in patients with tuberculosis (TB) may be useful for predicting and monitoring response to treatment. The relationship between quantitative T-cell responses and mycobacterial load remains unclear. We hypothesised that, in a HIV-prevalent high burden setting, the magnitude of mycobacterial antigen-specific and non-specific T-cell IFN-γ responses would correlate with (a) bacterial load and (b) culture conversion in patients undergoing treatment.We compared baseline (n = 147), 2 (n = 35) and 6 month (n = 13) purified-protein-derivative (PPD) and RD1-specific (TSPOT.TB and QFT-GIT) blood RD1-specific (TSPOT.TB; QFT-GIT) responses with associates of sputum bacillary load in patients with culture-confirmed TB in Cape Town, South Africa.IFN-γ responses were not associated with liquid culture time-to-positivity, smear-grade, Xpert MTB/RIF-generated cycle threshold values or the presence of cavities on the chest radiograph in patients with culture-confirmed TB and irrespective of HIV-status. 2-month IGRA conversion rates (positive-to-negative) were negligible [<11% for TSPOT.TB (3/28) and QFT-GIT (1/29)] and lower compared to culture [60% (21/35); p<0.01].In a high burden HIV-prevalent setting T-cell IFN-γ responses to M. tuberculosis-specific and non-specific antigens do not correlate with bacillary load, including Xpert MTB/RIF-generated C(T) values, and are therefore poorly suited for monitoring treatment and prognostication