Environmental Impact of Rotationally Grazed Pastures at Different Management Intensities in South Africa

Nitrogen fertilization, irrigation and concentrate feeding are important factors in rotational pasture management for dairy farms in South Africa. The extent to which these factors affect environmental efficiency is subject to current and intense debate among scientists. A three-year field study was conducted to investigate the yield response of different N-fertilizer treatments (0 (N0), 220 (N20), 440 (N40), 660 (N60) and 880 (N80) kg N ha-1 year-1) on grazed pastures and to calculate the carbon footprint (CF) of milk produced. Excessive N-fertilization (N60 and N80) did not increase herbage dry matter and energy yields from pastures. However, N80 indicated the highest N-yield but at the same time also the highest N surpluses at field level. A maximum fertilizer rate of 220 kg ha-1 year-1 (in addition to excreted N from grazing animals) appears sufficient to ensure adequate herbage yields (~20 t DM ha-1 year-1) with a slightly positive field-N-balance. This amount will prevent the depletion of soil C and N, with low N losses to the environment, where adequate milk yields of ~17 t ECM ha-1 with a low CF (~1.3 kg CO2 kg ECM-1) are reached. Methane from enteric fermentation (~49% ± 3.3) and N2O (~16% ± 3.2) emissions from irrigated pastures were the main contributors to the CF. A further CF reduction can be achieved by improved N-fertilization planning, low emission irrigation techniques and strategies to limit N2O emissions from pasture soils in South Africa

Feasibility of overnight electrical stimulation-induced muscle activation in people with a spinal cord injury:A Pilot study

Contains fulltext : 218680.pdf (Publisher’s version ) (Closed access)Study Design: We investigated whether overnight ES is a feasible method to activate gluteal, quadriceps, and hamstrings muscles in a two-week experiment. Electrical stimulation (ES) induced muscle contractions have proven positive effects on risk factors for developing pressure ulcers in people with a spinal cord injury (SCI). Therefore prolonged overnight ES-induced muscle activation is interesting, but has never been studied. Objective: To study feasibility of ES-induced leg muscle activation. In eight participants with motor complete SCI gluteal, hamstrings and quadriceps muscles were activated with a 2-weeks overnight stimulation protocol, 8 h per night, using specially developed ES-shorts. Setting: The Netherlands. Methods: Muscle fatigue was determined with a muscle contraction sensor. Questionnaires on sleep quality (SQ) and the ES-shorts usability were taken. Results: After 8 h of activation muscles still contracted, although fatigue occurred, and mean contraction size was lower at the end of a cycle (p = 0.03). SQ (0-100) after intervention was 75, and 66 after 4 weeks without overnight ES (p = 0.04) indicating ES improves sleep quality. The usability of the ES-shorts was good. Conclusions: This study shows that overnight ES-induced muscle activation using ES-shorts in SCI is a new, feasible method that does not interfere with sleep. The nightly use of the ES-shorts might be considered as an important part of the daily routine in SCI

Grazing under irrigation affects N2O-emissions substantially in South Africa

CITATION: Smit, H. P. J. et al. 2020. Grazing under irrigation affects N2O-emissions substantially in South Africa. Atmosphere, 11(9):925, doi:10.3390/atmos11090925.The original publication is available at https://www.mdpi.comFertilized agricultural soils serve as a primary source of anthropogenic N2O emissions. In South Africa, there is a paucity of data on N2O emissions from fertilized, irrigated dairy-pasture systems and emission factors (EF) associated with the amount of N applied. A first study aiming to quantify direct N2O emissions and associated EFs of intensive pasture-based dairy systems in sub-Sahara Africa was conducted in South Africa. Field trials were conducted to evaluate fertilizer rates (0, 220, 440, 660, and 880 kg N ha−1 year−1) on N2O emissions from irrigated kikuyu–perennial ryegrass (Pennisetum clandestinum–Lolium perenne) pastures. The static chamber method was used to collect weekly N2O samples for one year. The highest daily N2O fluxes occurred in spring (0.99 kg ha−1 day−1) and summer (1.52 kg ha−1 day−1). Accumulated N2O emissions ranged between 2.45 and 15.5 kg N2O-N ha−1 year−1 and EFs for mineral fertilizers applied had an average of 0.9%. Nitrogen in yielded herbage varied between 582 and 900 kg N ha−1. There was no positive effect on growth of pasture herbage from adding N at high rates. The relationship between N balance and annual N2O emissions was exponential, which indicated that excessive fertilization of N will add directly to N2O emissions from the pastures. Results from this study could update South Africa’s greenhouse gas inventory more accurately to facilitate Tier 3 estimates.https://www.mdpi.com/2073-4433/11/9/925Publisher's versio

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Nosocomial Transmission of Highly Resistant Microorganisms on a Spinal Cord Rehabilitation Ward

BACKGROUND/OBJECTIVE: To study the mechanism of nosocomial transmission of highly resistant microorganisms (HRMOs). DESIGN: A prospective observational study. SETTING: A spinal cord ward of a rehabilitation center. PARTICIPANTS: Patients admitted to the spinal cord rehabilitation ward. OUTCOME MEASURES: HRMOs present in urine and feces. HRMOs, Enterobacteriaceae: (1) that produced an extended-spectrum beta-lactamase (ESBL), (2) that were resistant to carbapenems, (3) that fluoroquinolones and aminoglycosides (for Escherichia coli and Klebsiella species), or other Enterobacteriaceae species that were resistant to 2 of 3 of the following types of antibiotics (fluoroquinolones, aminoglycosides, cotrimoxazole). METHODS: Bacterial growth, identification and sensitivity were tested in urine cultures of 46 patients and faeces cultures of 15 patients. Data were collected on demographic characteristics, underlying diseases, reason and date of admission, room number, method of catheterization (suprapubic, clean intermittent catheterization or indwelling Foley catheter) and antibiotic use. RESULTS: Nine different HRMOs (7 E. coli, 1 Enterobacter cloacae, and 1 Citrobacter koseri) were isolated in urine samples from 15 patients. E. coli resistant to gentamicin, tetracycline, amoxicillin, cotrimoxazole, and ciprofloxacin were isolated from 8 patients during the study (cluster 1). One strain of multiresistant E coli found before the start of the study was not found during the study period (cluster 2). E coli strains producing an ESBL and resistant to tetracycline, cotrimoxazole, and ciprofloxacin were isolated from urine samples of 3 patients (cluster 3). Ciprofloxacin-resistant E. coli were present in feces of 3 patients (2 in cluster 1). Catheterization was found to be significantly more prevalent in patients with HRMOs. Most of the patients in cluster 1 were treated with antibiotics before the first isolation of the strain. CONCLUSIONS: HRMOs from urine samples were strongly correlated with the use of catheterization. A close correlation was found between prior use of antibiotics and colonization of the urinary tract on the level of the individual patient, which has been rarely described in the literatur

Grazing under Irrigation Affects N2O-Emissions Substantially in South Africa

Fertilized agricultural soils serve as a primary source of anthropogenic N2O emissions. In South Africa, there is a paucity of data on N2O emissions from fertilized, irrigated dairy-pasture systems and emission factors (EF) associated with the amount of N applied. A first study aiming to quantify direct N2O emissions and associated EFs of intensive pasture-based dairy systems in sub-Sahara Africa was conducted in South Africa. Field trials were conducted to evaluate fertilizer rates (0, 220, 440, 660, and 880 kg N ha&minus;1 year&minus;1) on N2O emissions from irrigated kikuyu&ndash;perennial ryegrass (Pennisetum clandestinum&ndash;Lolium perenne) pastures. The static chamber method was used to collect weekly N2O samples for one year. The highest daily N2O fluxes occurred in spring (0.99 kg ha&minus;1 day&minus;1) and summer (1.52 kg ha&minus;1 day&minus;1). Accumulated N2O emissions ranged between 2.45 and 15.5 kg N2O-N ha&minus;1 year&minus;1 and EFs for mineral fertilizers applied had an average of 0.9%. Nitrogen in yielded herbage varied between 582 and 900 kg N ha&minus;1. There was no positive effect on growth of pasture herbage from adding N at high rates. The relationship between N balance and annual N2O emissions was exponential, which indicated that excessive fertilization of N will add directly to N2O emissions from the pastures. Results from this study could update South Africa&rsquo;s greenhouse gas inventory more accurately to facilitate Tier 3 estimates

Effects of Electrical Stimulation on Risk Factors for Developing Pressure Ulcers in People with a Spinal Cord Injury: A Focused Review of Literature

Pressure ulcers (PUs) are a common and serious problem for wheelchair users, such as individuals with a spinal cord injury (SCI), resulting in great discomfort, loss of quality of life, and significant medical care costs. Therefore, it is of utmost importance to prevent PUs. In this literature overview, the effects of electrical stimulation (ES) on the risk factors for developing PUs in people with an SCI are examined and synthesized from January 1980 to January 2015. Thirty-four relevant studies of PU prevention in SCI were identified. Four were randomized clinical trials, 24 were case series, 6 had other designs. Three types of ES modalities were identified. The methodological quality varied from poor to fairly strong, with a large variety in used ES parameters. Twenty-three studies were identified describing short-term effects of ES on interface pressure, oxygenation, and/or blood flow, and 24 studies described the long-term effects of ES on muscle volume, muscle strength, and histology. Whereas there is a lack of controlled studies on the effects of ES on PU incidence, which disallows definite conclusions, there is moderate evidence to suggest that ES-induced muscle activation has a positive influence on several risk factors for developing PUs in people with an SCI

Prolonged electrical stimulation-induced gluteal and hamstring muscle activation and sitting pressure in spinal cord injury: Effect of duty cycle

Pressure ulcers (PUs) are highly prevalent in people with spinal cord injury (SCI). Electrical stimulation (ES) activates muscles and might reduce risk factors. Our objectives were to study and compare the effects of two duty cycles during 3 h of ES-induced gluteal and hamstring activation on interface pressure distribution in sitting individuals with SCI and study the usability of a newly developed electrode garment (ES shorts). Ten individuals with SCI participated in this study, in which two ES protocols with different duty cycles (1:1 s vs 1:4 s on-off) were applied in counterbalanced order using a custom-made garment with built-in electrodes. Outcome variables included interface pressure of the ischial tuberosities (ITs) and pressure gradient. A questionnaire was used to determine usability of the ES shorts. In both protocols, ES caused a significant decrease in average IT pressure compared with rest (no ES); on average, 35% for protocol 1:4 and 13% for protocol 1:1. The ES on-off duty cycle of protocol 1:4 showed less muscle fatigue. In general, participants scored the usability of the ES shorts as satisfactory. In this study, the application of ES resulted in a significant decrease in IT pressure. The ES on-off duty cycle of 1:4 s is recommended because of the less fatiguing effect. ES of the hamstrings and gluteal muscles might be a promising method in preventing PUs, but further study is needed

Optimization of protocols using neuromuscular electrical stimulation for paralyzed lower-limb muscles to increase energy expenditure in people with spinal cord injury

OBJECTIVE: To evaluate if using surface neuromuscular electrical stimulation (NMES) for paralyzed lower-limb muscles results in an increase in energy expenditure and if the number of activated muscles and duty cycle affect the potential increase. DESIGN: Cross-sectional study. RESULTS: Energy expenditure during all NMES protocols was significantly higher than the condition without NMES (1.2 ± 0.2 kcal/min), with the highest increase (+ 51%; +0.7 kcal/min, 95% CI: 0.3 - 1.2) for the protocol with more muscles activated and the duty cycle with a shorter rest period. A significant decrease in muscle contraction size during NMES was found with a longer stimulation time, more muscles activated or the duty cycle with a shorter rest period. CONCLUSION: Using NMES for paralyzed lower-limb muscles can significantly increase the energy expenditure compared to sitting without NMES with the highest increase for the protocol with more muscles activated and the duty cycle with a shorter rest period. Muscle fatigue occurred significantly with the more intense NMES protocols which might cause a lower energy expenditure in a longer protocol. Future studies should further optimize the NMES parameters and investigate the long-term effects of NMES on weight management in people with SCI