544 research outputs found
Effect of Dietary Starch Source and Concentration on Equine Fecal Microbiota
Starch from corn is less susceptible to equine small intestinal digestion than starch from oats, and starch that reaches the hindgut can be utilized by the microbiota. The objective of the current study was to examine the effects of starch source on equine fecal microbiota. Thirty horses were assigned to treatments: control (hay only), HC (high corn), HO (high oats), LC (low corn), LO (low oats), and LW (low pelleted wheat middlings). Horses received an all-forage diet (2 wk; d -14 to d -1) before the treatment diets (2 wk; d 1 to 14). Starch was introduced gradually so that horses received 50% of the assigned starch amount (high = 2 g starch/kg BW; low = 1 g starch/kg BW) by d 4 and 100% by d 11. Fecal samples were obtained at the end of the forage-only period (S0; d -2), and on d 6 (S1) and d 13 (S2) of the treatment period. Cellulolytics, lactobacilli, Group D Gram-positive cocci (GPC), lactate-utilizers and amylolytics were enumerated. Enumeration data were log transformed and analyzed by repeated measures ANOVA. There were sample day × treatment interactions (P \u3c 0.0001) for all bacteria enumerated. Enumerations from control horses did not change during the sampling period (P \u3e 0.05). All treatments except LO resulted in increased amylolytics and decreased cellulolytics, but the changes were larger in horses fed corn and wheat middlings (P \u3c 0.05). Feeding oats resulted in increased lactobacilli and decreased GPC (P \u3c 0.05), while corn had the opposite effects. LW had increased lactobacilli and GPC (P \u3c 0.05). The predominant amylolytic isolates from HC, LC and LW on S2 were identified by 16S RNA gene sequencing as Enterococcus faecalis, but other species were found in oat fed horses. These results demonstrate that starch source can have a differential effect on the equine fecal microbiota
Effect of Dietary Starch Source and Concentration on Equine Fecal Microbiota
Starch from corn is less susceptible to equine small intestinal digestion than starch from oats, and starch that reaches the hindgut can be utilized by the microbiota. The objective of the current study was to examine the effects of starch source on equine fecal microbiota. Thirty horses were assigned to treatments: control (hay only), HC (high corn), HO (high oats), LC (low corn), LO (low oats), and LW (low pelleted wheat middlings). Horses received an all-forage diet (2 wk; d -14 to d -1) before the treatment diets (2 wk; d 1 to 14). Starch was introduced gradually so that horses received 50% of the assigned starch amount (high = 2 g starch/kg BW; low = 1 g starch/kg BW) by d 4 and 100% by d 11. Fecal samples were obtained at the end of the forage-only period (S0; d -2), and on d 6 (S1) and d 13 (S2) of the treatment period. Cellulolytics, lactobacilli, Group D Gram-positive cocci (GPC), lactate-utilizers and amylolytics were enumerated. Enumeration data were log transformed and analyzed by repeated measures ANOVA. There were sample day × treatment interactions (P \u3c 0.0001) for all bacteria enumerated. Enumerations from control horses did not change during the sampling period (P \u3e 0.05). All treatments except LO resulted in increased amylolytics and decreased cellulolytics, but the changes were larger in horses fed corn and wheat middlings (P \u3c 0.05). Feeding oats resulted in increased lactobacilli and decreased GPC (P \u3c 0.05), while corn had the opposite effects. LW had increased lactobacilli and GPC (P \u3c 0.05). The predominant amylolytic isolates from HC, LC and LW on S2 were identified by 16S RNA gene sequencing as Enterococcus faecalis, but other species were found in oat fed horses. These results demonstrate that starch source can have a differential effect on the equine fecal microbiota
Development and application of a comprehensive analytical workflow for the quantification of non-volatile low molecular weight lipids on archaeological stone tools
Source determination of use-related residues on prehistoric stone tools is especially challenging, due to issues related to preservation, contamination and the contribution of residues from multiple sources. To increase confidence in this process, an analytical workflow was developed to include: (1) a sampling strategy that retains spatial information of the recovered residues and enables monitoring of environmental contamination; and (2) a sensitive and selective gas chromatography-tandem mass spectrometry (GC-MS/MS) procedure to quantify non-volatile low molecular weight lipids on stone artefacts. This workflow was applied to 14 stone artefacts excavated from deposits at Liang Bua, a limestone cave on the Indonesian island of Flores. These artefacts range in age between ∼14 000 and 1000 years old, and were preliminarily classified as either potentially showing traces of use (n = 7) or not (n = 7) using low magnification microscopy. Residues were sampled by direct solvent extraction off the surface of the artefacts. The aliquots were spiked with internal standards and derivatised. The trimethylsilyl derivatives of 40 saturated fatty acids, sterols, di- and tri-terpenoids and their analogues were quantified using optimised multiple reaction monitoring (MRM) transitions. Six of the potentially used artefacts contained sterols, phytosterols and terpenoids, either individually or in combination, whereas none of these compounds was commonly found on the seven artefacts preliminarily classified as unused. This suggests that these six artefacts may have been used as implements to process resources, and provides scope for further investigation. This workflow can also be adapted for the analysis of other archaeological objects
Combined organic biomarker and use-wear analyses of stone artefacts from Liang Bua, Flores, Indonesia
Organic biomarker and lithic use-wear analyses of archaeological implements manufactured and/or used by hominins in the past offers a means of assessing how prehistoric peoples utilised natural resources. Currently, most studies focus on one of these techniques, rather than using both in sequence. This study aims to assess the potential of combining both methods to analyse stone artefacts, using a set of 69 stones excavated from the cave site of Liang Bua (Flores, Indonesia). Prior to chemical analysis, an initial inspection of the artefacts revealed potential use-wear traces but no visible residues. Gas chromatography mass spectrometry (GC-MS) analysis, including the targeting of 86 lipids, terpenes, terpenoids, alkanes and their analogues, found compounds with plant or animal origin on 27 of the 69 stones. The artefacts were subsequently cleaned, and use-wear analysis identified traces of use on 43 artefacts. Use-wear analysis confirmed traces of use on 23 of the 27 artefacts with potential use-residues that were determined by GC-MS. The GC-MS results were broadly consistent with the functional classes identified in the later use-wear analysis. This inclusive approach for stone artefact analysis strengthens the identifications made through multiple lines of enquiry. There remain conflicts and uncertainties in specific cases, suggesting the need for further refinement and analyses of the relationships between use-wear and residues
Preliminary Test Results for Stability and Control Characteristics of a Generic T-Tail Transport Airplane at High Angle of Attack
Tests of a generic T-tail transport airplane, in flaps-up configuration, were conducted using two wind tunnels, a water tunnel, and computational fluid dynamics. Static force and moment testing, forced oscillation testing and dye flow visualization test techniques were used. The purpose of the testing was to obtain stability and control characteristics for development of a research flight simulator aerodynamic database. The purpose of that database was for assessment of aerodynamic model fidelity requirements to train airline pilots to recognize and recover from full stall conditions. Preliminary results, at initial stall conditions, include: an unstable stall pitch break, and near-neutral roll damping. Preliminary results, at deep stall conditions, include: a potential static longitudinal trim condition at approximately 35 degrees angle of attack, large aerodynamic asymmetries, and localized unstable dynamic stability
The impact of an intervention to introduce malaria rapid diagnostic tests on fever case management in a high transmission setting in Uganda: A mixed-methods cluster-randomized trial (PRIME).
Rapid diagnostic tests for malaria (mRDTs) have been scaled-up widely across Africa. The PRIME study evaluated an intervention aiming to improve fever case management using mRDTs at public health centers in Uganda. A cluster-randomized trial was conducted from 2010-13 in Tororo, a high malaria transmission setting. Twenty public health centers were randomized in a 1:1 ratio to intervention or control. The intervention included training in health center management, fever case management with mRDTs, and patient-centered services; plus provision of mRDTs and artemether-lumefantrine (AL) when stocks ran low. Three rounds of Interviews were conducted with caregivers of children under five years of age as they exited health centers (N = 1400); reference mRDTs were done in children with fever (N = 1336). Health worker perspectives on mRDTs were elicited through semi-structured questionnaires (N = 49) and in-depth interviews (N = 10). The primary outcome was inappropriate treatment of malaria, defined as the proportion of febrile children who were not treated according to guidelines based on the reference mRDT. There was no difference in inappropriate treatment of malaria between the intervention and control arms (24.0% versus 29.7%, adjusted risk ratio 0.81 95\% CI: 0.56, 1.17 p = 0.24). Most children (76.0\%) tested positive by reference mRDT, but many were not prescribed AL (22.5\% intervention versus 25.9\% control, p = 0.53). Inappropriate treatment of children testing negative by reference mRDT with AL was also common (31.3\% invention vs 42.4\% control, p = 0.29). Health workers appreciated mRDTs but felt that integrating testing into practice was challenging given constraints on time and infrastructure. The PRIME intervention did not have the desired impact on inappropriate treatment of malaria for children under five. In this high transmission setting, use of mRDTs did not lead to the reductions in antimalarial prescribing seen elsewhere. Broader investment in health systems, including infrastructure and staffing, will be required to improve fever case management
Determination of HIV status and identification of incident HIV infections in a large, community-randomized trial: HPTN 071 (PopART).
INTRODUCTION: The HPTN 071 (PopART) trial evaluated the impact of an HIV combination prevention package that included "universal testing and treatment" on HIV incidence in 21 communities in Zambia and South Africa during 2013-2018. The primary study endpoint was based on the results of laboratory-based HIV testing for>Â 48,000 participants who were followed for up to three years. This report evaluated the performance of HIV assays and algorithms used to determine HIV status and identify incident HIV infections in HPTN 071, and assessed the impact of errors on HIV incidence estimates. METHODS: HIV status was determined using a streamlined, algorithmic approach. A single HIV screening test was performed at centralized laboratories in Zambia and South Africa (all participants, all visits). Additional testing was performed at the HPTN Laboratory Center using antigen/antibody screening tests, a discriminatory test and an HIV RNA test. This testing was performed to investigate cases with discordant test results and confirm incident HIV infections. RESULTS: HIV testing identified 978 seroconverter cases. This included 28 cases where the participant had acute HIV infection at the first HIV-positive visit. Investigations of cases with discordant test results identified cases where there was a participant or sample error (mixups). Seroreverter cases (errors where status changed from HIV infected to HIV uninfected, 0.4% of all cases) were excluded from the primary endpoint analysis. Statistical analysis demonstrated that exclusion of those cases improved the accuracy of HIV incidence estimates. CONCLUSIONS: This report demonstrates that the streamlined, algorithmic approach effectively identified HIV infections in this large cluster-randomized trial. Longitudinal HIV testing (all participants, all visits) and quality control testing provided useful data on the frequency of errors and provided more accurate data for HIV incidence estimates
American Society of Clinical Oncology/College ofAmerican Pathologists guideline recommendations forimmunohistochemical testing of estrogen andprogesterone receptors in breast cancer
Purpose: To develop a guideline to improve theaccuracy of immunohistochemical (IHC) estrogen receptor(ER) and progesterone receptor (PgR) testing in breastcancer and the utility of these receptors as predictivemarkers.Methods: The American Society of Clinical Oncologyand the College of American Pathologists convened aninternational Expert Panel that conducted a systematicreview and evaluation of the literature in partnership withCancer Care Ontario and developed recommendations foroptimal IHC ER/PgR testing performance.Results: Up to 20% of current IHC determinations ofER and PgR testing worldwide may be inaccurate (falsenegative or false positive). Most of the issues with testinghave occurred because of variation in preanalyticvariables, thresholds for positivity, and interpretationcriteria.Recommendations: The Panel recommends that ER andPgR status be determined on all invasive breast cancers andbreast cancer recurrences. A testing algorithm that relieson accurate, reproducible assay performance is proposed.Elements to reliably reduce assay variation are specified. It is recommended that ER and PgR assays be consideredpositive if there are at least 1% positive tumor nuclei in the sample on testing in the presence of expected reactivity of internal (normal epithelial elements) and external controls. The absence of benefit from endocrine therapy for women with ER-negative invasive breast cancers has been confirmed in large overviews of randomized clinical trials.(Arch Pathol Lab Med. 2010;134:907–922
Effect of Black Tea Intake on Blood Cholesterol Concentrations in Individuals with Mild Hypercholesterolemia: A Diet-Controlled Randomized Trial
Habitual intake of black tea has been associated with relatively lower serum cholesterol concentrations in observational studies. However, clinical trial results evaluating the effects of black tea on serum cholesterol have been inconsistent. Several factors could explain these mixed results, in particular, uncontrolled confounding caused by lifestyle factors, e.g. diet. This diet-controlled clinical trial estimates the effect of black tea flavonoid consumption on cholesterol concentrations in 57 borderline hypercholesterolemic individuals (total cholesterol concentrations between 190 and 260 mg/dl (4.9 and 6.7 mmol/L)). A double blind, randomized crossover trial was conducted in Minneapolis, MN from April 2002 through April 2004, wherein key conditions were tightly controlled to minimize possible confounding. Participants consumed a controlled low-flavonoid diet plus 5 cups per day of black tea or tea-like placebo over two 4-week treatment periods. The flavonoid-free caffeinated placebo matched the tea in color and taste. Differences in cholesterol concentrations at the end of each treatment period were evaluated via linear mixed models. Differences (95% CI) in mg/dl among those treated with tea versus placebo were 3.43 (−7.08, 13.94) for total cholesterol, −1.02 (−11.34, 9.30) for low-density lipoprotein cholesterol (LDL-C), 0.58 (−2.98, 4.14) for high-density lipoprotein cholesterol (HDL-C), 15.22 (−40.91, 71.35) for triglycerides, and −0.39 (−11.16, 10.38) for LDL plus HDL cholesterol fraction. The LCL-C/HDL-C ratio decreased by −0.1 units (95% CI −0.41, 0.21). No results were statistically or clinically significant. Thus, the intake of 5 cups of black tea per day did not significantly alter the lipid profile of borderline hypercholesterolemic subjects
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