Effect of supplemental dietary selenium on growing-finishing pig performance and hepatic and erythrocyte glutathione peroxidase activity

Ninety-eight Yorkshire x Duroc pigs were utilized in this study to determine the effect of six supplemental dietary levels of selenium on growing-finishing pig performance and erythrocyte and hepatic glutathione peroxidase levels in the pig. The pigs were fed a basal corn-soybean meal ration containing approximately 50ppb natural selenium or the basal ration supplemented with 25, 50, 75, 100, 125 or 150 ppb Se as sodium selenite. The pigs were weighed biweekly, feed was measured and performance data were calculated every two weeks during the trial. Blood samples were collected from eight pigs on each treatment after 70 days on experiment and at slaughter. Hemoglobin and percent packed cell volumes were determined at the time the blood samples were collected. Erythrocytes from all blood samples were prepared by washing twice with sodium-phosphate-saline buffer and then frozen at -20°C until they were analyzed for glutathione peroxidase activity. Liver samples were collected at slaughter and were stored frozen until the analysis for glutathione peroxidase could be conducted. The results of this study indicate that there were no significant differences due to treatment on the performance criteria or carcass data that were measured in this study. Erythrocyte glutathione and enzyme units of activity were not significantly affected by treatment at 70 days of this experiment. However, pigs receiving the basal diet without any added selenium had noticeably lower levels of glutathione and enzyme units of activity on the seventieth day of the experiment. This finding suggests that the basal control ration was possibly marginal to deficient in selenium and that the supplemental levels overcame the marginal deficiency. Erythrocyte glutathione peroxidase enzyme units of activity and enzyme units of activity per milligram of hemoglobin at slaughter were significantly (P\u3c.05) affected by treatment. These differences were not linearly increased with increasing level of supplemental Se. No consistent trend was observed and the randomness of the values may be partially explained by the hypothesis of Mahan et al. (1977) who suggested that pigs during the finishing phase may require only 50ppb Se. Since the basal diet in this study contained approximately 50ppb natural Se, the addition of supplemental Se would not be expected to have a consistent linear effect on glutathione peroxidase activity. No significant differences due to treatment in hepatic glutathione peroxidase were observed in this study. The fact that pigs utilized in this study were not depleted of their Se reserves before the experiment was initiated and the hypothesis of Mahan et al. (1977) may explain partially the results obtained for hepatic glutathione peroxidase in this study

TERMINAL MARKET WINDOWS FOR MISSISSIPPI SMALL-FARM VEGETABLE PRODUCERS

This study investigated various marketing strategies involving market windows at wholesale fruit and vegetable terminal markets. Data used in the analysis included weekly prices for okra, sweet corn, strawberries, and green cabbage at terminal markets located in Dallas, St. Louis, Atlanta, Chicago, Cincinnati, and Detroit. Strawberries showed relatively high profit margins for small farmers operating in southwest Mississippi. Sweet corn and okra showed more narrow profit margins, while green cabbage appeared to yield negative net returns (generally) for these farmers. Furthermore, stochastic dominance analysis of various combinations of crop/market/window revealed the following as the preferred marketing strategies: (1) strawberries in all markets in the last third of the calendar year; (2) sweet corn in all six markets in the first third of the calendar year; and (3) okra in St. Louis and Cincinnati in the first third of the calendar year.Agribusiness,

A generative model for feedback networks

We investigate a simple generative model for network formation. The model is designed to describe the growth of networks of kinship, trading, corporate alliances, or autocatalytic chemical reactions, where feedback is an essential element of network growth. The underlying graphs in these situations grow via a competition between cycle formation and node addition. After choosing a given node, a search is made for another node at a suitable distance. If such a node is found, a link is added connecting this to the original node, and increasing the number of cycles in the graph; if such a node cannot be found, a new node is added, which is linked to the original node. We simulate this algorithm and find that we cannot reject the hypothesis that the empirical degree distribution is a q-exponential function, which has been used to model long-range processes in nonequilibrium statistical mechanics.Comment: 11 pages, 6 figure

Unintended Consequences of Air Cleaning Chemistry

Amplified interest in maintaining clean indoor air associated with the airborne transmission risks of SARS-CoV-2 have led to an expansion in the market for commercially available air cleaning systems. While the optimal way to mitigate indoor air pollutants or contaminants is to control (remove) the source, air cleaners are a tool for use when absolute source control is not possible. Interventions for indoor air quality management include physical removal of pollutants through ventilation or collection on filters and sorbent materials, along with chemically reactive processes that transform pollutants or seek to deactivate biological entities. This perspective intends to highlight the perhaps unintended consequences of various air cleaning approaches via indoor air chemistry. Introduction of new chemical agents or reactive processes can initiate complex chemistry that results in the release of reactive intermediates and/or byproducts into the indoor environment. Since air cleaning systems are often continuously running to maximize their effectiveness and most people spend a vast majority of their time indoors, human exposure to both primary and secondary products from air cleaners may represent significant exposure risk. This Perspective highlights the need for further study of chemically reactive air cleaning and disinfection methods before broader adoption

Determination of energy barrier profiles for high-k dielectric materials utilizing bias-dependent internal photoemission

We utilize bias-dependent internal photoemission spectroscopy to determine the metal/dielectric/silicon energy barrier profiles for Au/HfO2/Si and Au/Al2O3/Si structures. The results indicate that the applied voltage plays a large role in determining the effective barrier height and we attribute much of the variation in this case to image potential barrier lowering in measurements of single layers. By measuring current at both positive and negative voltages, we are able to measure the band offsets from Si and also to determine the flatband voltage and the barrier asymmetry at 0 V. Our SiO2 calibration sample yielded a conduction band offset value of 3.03+/-0.1 eV. Measurements on HfO2 give a conduction band offset value of 2.7+/-0.2 eV (at 1.0 V) and Al2O3 gives an offset of 3.3+/-0.1 (at 1.0 V). We believe that interfacial SiO2 layers may dominate the electron transport from silicon for these films. The Au/HfO2 barrier height was found to be 3.6+/-0.1 eV while the Au/Al2O3 barrier is 3.5+/-0.1 eV

Genetic mapping of legume orthologs reveals high conservation of synteny between lentil species and the sequenced genomes of Medicago and chickpea.

Lentil (Lens culinaris Medik.) is a global food crop with increasing importance for food security in south Asia and other regions. Lens ervoides, a wild relative of cultivated lentil, is an important source of agronomic trait variation. Lens is a member of the galegoid clade of the Papilionoideae family, which includes other important dietary legumes such as chickpea (Cicer arietinum) and pea (Pisum sativum), and the sequenced model legume Medicago truncatula. Understanding the genetic structure of Lens spp. in relation to more fully sequenced legumes would allow leveraging of genomic resources. A set of 1107 TOG-based amplicons were identified in L. ervoides and a subset thereof used to design SNP markers for mapping. A map of L. ervoides consisting of 377 SNP markers spread across seven linkage groups was developed using a GoldenGate genotyping array and single SNP marker assays. Comparison with maps of M. truncatula and L. culinaris documented considerable shared synteny and led to the identification of a few major translocations and a major inversion that distinguish Lens from M. truncatula, as well as a translocation that distinguishes L. culinaris from L. ervoides. The identification of chromosome-level differences among Lens spp. will aid in the understanding of introgression of genes from L. ervoides into cultivated L. culinaris, furthering genetic research and breeding applications in lentil

Ethnic disparities in initiation and intensification of diabetes treatment in adults with type 2 diabetes in the UK, 1990-2017: A cohort study.

BACKGROUND: Type 2 diabetes mellitus (T2DM) disproportionately affects individuals of nonwhite ethnic origin. Timely and appropriate initiation and intensification of glucose-lowering therapy is key to reducing the risk of major vascular outcomes. Given that ethnic inequalities in outcomes may stem from differences in therapeutic management, the aim of this study was to identify ethnic differences in the timeliness of initiation and intensification of glucose-lowering therapy in individuals newly diagnosed with T2DM in the United Kingdom. METHODS AND FINDINGS: An observational cohort study using the Clinical Practice Research Datalink was conducted using 162,238 adults aged 18 and over diagnosed with T2DM between 1990 and 2017 (mean age 62.7 years, 55.2% male); 93% were of white ethnicity (n = 150,754), 5% were South Asian (n = 8,139), and 2.1% were black (n = 3,345). Ethnic differences in time to initiation and intensification of diabetes treatment were estimated at three time points (initiation of noninsulin monotherapy, intensification to noninsulin combination therapy, and intensification to insulin therapy) using multivariable Cox proportional hazards regression adjusted for factors a priori hypothesised to be associated with initiation and intensification: age, sex, deprivation, glycated haemoglobin (HbA1c), body mass index (BMI), smoking status, comorbidities, consultations, medications, calendar year, and clustering by practice. Odds of experiencing therapeutic inertia (failure to intensify treatment within 12 months of HbA1c >7.5% [58 mmol/mol]), were estimated using multivariable logistic regression adjusted for the same hypothesised confounders. Noninsulin monotherapy was initiated earlier in South Asian and black groups (South Asian HR 1.21, 95% CI 1.08-1.36, p < 0.001; black HR 1.29, 95% CI 1.05-1.59, p = 0.017). Correspondingly, no ethnic differences in therapeutic inertia were evident at initiation. Intensification with noninsulin combination therapy was slower in both nonwhite ethnic groups relative to white (South Asian HR 0.80, 95% CI 0.74-0.87, p < 0.001; black HR 0.79, 95% CI 0.70-0.90, p < 0.001); treatment inertia at this stage was greater in nonwhite groups relative to white (South Asian odds ratio [OR] 1.45, 95% CI 1.23-1.70, p < 0.001; black OR 1.43, 95% CI 1.09-1.87, p = 0.010). Intensification to insulin therapy was slower again for black groups relative to white groups (South Asian HR 0.49, 95% CI 0.41-0.58, p < 0.001; black HR 0.69, 95% CI 0.53-0.89, p = 0.012); correspondingly, treatment inertia was significantly higher in nonwhite groups at this stage relative to white groups (South Asian OR 2.68, 95% CI 1.89-3.80 p < 0.001; black OR 1.82, 95% CI 1.13-2.79, p = 0.013). At both stages of treatment intensification, nonwhite groups had fewer HbA1c measurements than white groups. Limitations included variable quality and completeness of routinely recorded data and a lack of information on medication adherence. CONCLUSIONS: In this large UK cohort, we found persuasive evidence that South Asian and black groups intensified to noninsulin combination therapy and insulin therapy more slowly than white groups and experienced greater therapeutic inertia following identification of uncontrolled HbA1c. Reasons for delays are multifactorial and may, in part, be related to poorer long-term monitoring of risk factors in nonwhite groups. Initiatives to improve timely and appropriate intensification of diabetes treatment are key to reducing disparities in downstream vascular outcomes in these populations

Exercise Increases Insulin Content and Basal Secretion in Pancreatic Islets in Type 1 Diabetic Mice

Exercise appears to improve glycemic control for people with type 1 diabetes (T1D). However, the mechanism responsible for this improvement is unknown. We hypothesized that exercise has a direct effect on the insulin-producing islets. Eight-week-old mice were divided into four groups: sedentary diabetic, exercised diabetic, sedentary control, and exercised control. The exercised groups participated in voluntary wheel running for 6 weeks. When compared to the control groups, the islet density, islet diameter, and β-cell proportion per islet were significantly lower in both sedentary and exercised diabetic groups and these alterations were not improved with exercise. The total insulin content and insulin secretion were significantly lower in sedentary diabetics compared to controls. Exercise significantly improved insulin content and insulin secretion in islets in basal conditions. Thus, some improvements in exercise-induced glycemic control in T1D mice may be due to enhancement of insulin content and secretion in islets