Role of physically effective fiber and estimation of dietary fiber adequacy in high-producing dairy cattle

Highly fermentable diets require the inclusion of adequate amounts of fiber to reduce the risk of subacute rumen acidosis (SARA). To assess the adequacy of dietary fiber in dairy cattle, the concept of physically effective neutral detergent fiber (peNDF) has received increasing attention because it amalgamates information on both chemical fiber content and particle size (PS) of the feedstuffs. The nutritional effects of dietary PS and peNDF are complex and involve feed intake behavior (absolute intake and sorting behavior), ruminal mat formation, rumination and salivation, and ruminal motility. Other effects include fermentation characteristics, digesta passage, and nutrient intake and absorption. Moreover, peNDF requirements depend on the fermentability of the starch source (i.e., starch type and endosperm structure). To date, the incomplete understanding of these complex interactions has prevented the establishment of peNDF as a routine method to determine dietary fiber adequacy so far. Therefore, this review is intended to analyze the quantitative effects of and interactions among forage PS, peNDF, and diet fermentability with regard to rumen metabolism and prevention of SARA, and aims to give an overview of the latest achievements in the estimation of dietary fiber adequacy in high-producing dairy cattle. Recently developed models that synthesize the effects of both peNDF and fermentable starch on rumen metabolism appear to provide an appropriate basis for estimation of dietary fiber adequacy in high-producing dairy cows. Data suggest that a period lasting more than 5 to 6h/d during which ruminal pH is <5.8 should be avoided to minimize health disturbances due to SARA. The knowledge generated from these modeling approaches recommends that average amounts of 31.2% peNDF inclusive particles >1.18mm (i.e., peNDF(>1.18)) or 18.5% peNDF inclusive particles >8mm (i.e., peNDF(>8)) in the diet (DM basis) are required. However, inclusion of a concentration of peNDF(>8) in the diet beyond 14.9% of diet DM may lower DM intake level. As such, more research is warranted to develop efficient feeding strategies that encourage inclusion of energy-dense diets without the need to increase their content in peNDF above the threshold that leads to lower DM intake. The latter would require strategies that modulate the fermentability characteristics of the diet and promote absorption and metabolic capacity of ruminal epithelia of dairy cows

Measuring psychological distress using the K10 in Kenya

Background The Kessler psychological distress scale (K10) is a brief screening tool that assesses psychological distress in both clinical and epidemiological settings. Despite wide applicability of the K10 globally, there are no data on psychometric properties of the K10 in Kenya. This study investigated the reliability, factor structure, and construct validity of the K10 as a measure of psychological distress among adults in Kenya. Methods A total of 2556 adults attending 11 outpatient clinics in the western and coastal regions of Kenya without a history or clinical diagnosis of psychotic disorders were included. Data were collected on demographic characteristics of the participants and the K10. Internal consistency was evaluated using Cronbach's alpha. Construct validity and factor structures of the K10 were evaluated using both exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) approaches. Results The mean K10 score was 3.4 and Cronbach's alpha was 0.85, indicating good internal consistency (reliability). EFA resulted in a two-factor solution that accounted for 67.6% of variance. CFA results indicated that a unidimensional model with correlated errors best fit the data. Limitations The K10 was only administered to a control group of our study population, which had low levels of psychological distress. Conclusion The K10 has good construct validity and reliability for use as a broad measure of psychological distress in Kenyan adults and may be useful in general medical setting to assess anxiety and depressive disorders

Traumatic experiences assessed with the life events checklist for Kenyan adults

Background Life Events Checklist (LEC-5) has been widely used to assess for exposure to potentially traumatic life events (PTEs), but its psychometric properties have not been evaluated in Kenya. The objectives of this study were to determine the frequency and types of PTEs within this setting and to examine the construct validity of LEC-5 in Kenya. Methods The LEC-5 was administered to 5316 participants in the ongoing multisite case–control study of Neuropsychiatric Genetics of African Populations-Psychosis. We used exploratory factor analysis to assess LEC-5 structure, and conducted confirmatory factor analyses to compare these results with two other models: a six-factor model based on the only prior EFA of the LEC and a theoretical seven-factor model. Results The majority (63.4% overall and 64.4% of cases and 62.4% of controls) of participants had experienced at least one PTE in their lifetime. Results of the exploratory factor analyses for LEC-5 yielded a seven-factor solution with eigenvalues greater than one, accounting for 55.3% of the common variance. Based on confirmatory factor analyses, all three models had good fit for our sample, but the theoretical seven-factor model had the best fit. Limitations The study did not assess if the participants perceived experiences as traumatic, we did not carry out test retest reliability or and we did not consider cultural variations in perception of trauma. Conclusion This study provides evidence of a high prevalence of traumatic life events and for the construct validity of LEC-5 in assessing PTE exposures in a Kenyan setting

Factor structure and item response of psychosis symptoms among Kenyan adults

&lt;h4&gt;Background&lt;/h4&gt;The aim of this study was to evaluate the construct validity of the psychosis module of the Mini International Neuropsychiatric Interview version 7.0.2 (MINI-7).&lt;h4&gt;Method&lt;/h4&gt;We utilized data collected from 2738 participants with a primary psychotic or bipolar disorder. Participants were drawn from two Kenyan sites of a large multi-center neuropsychiatric genetic study. The factor structure of the MINI-7 psychosis items were explored using confirmatory factor analyses (CFA) and Item Response Theory approach, for the full sample and by gender.&lt;h4&gt;Results&lt;/h4&gt;The CFA revealed that a 1-factor model provided adequate fit for the MINI-7 psychosis items for the full sample (x&lt;sup&gt;2&lt;/sup&gt; = 397.92, df = 35, p &lt; .0001; RMSEA = 0.06; CFI = 0.92; TLI = 0.90) as well as for the female (x&lt;sup&gt;2&lt;/sup&gt; = 185.16.92, df = 35, p &lt; .0001; RMSEA = 0.06; CFI = 0.93; TLI = 0.91) and male groups (x&lt;sup&gt;2&lt;/sup&gt; = 242.09, df = 35, p &lt; .0001; RMSEA = 0.06; CFI = 0.92; TLI = 0.89). Item thresholds for the full sample, and female and male groups were highest for 'odd beliefs' (-1.42, -1.33, and -1.51 respectively) and lowest for 'visual hallucinations' (-0.03, -0.04, and -0.01 respectively).&lt;h4&gt;Limitations&lt;/h4&gt;Our study used a hospital-based population, which may have excluded patients with milder psychotic symptoms. Findings may therefore not be generalizable to the community setting.&lt;h4&gt;Conclusions&lt;/h4&gt;Our findings indicate good construct validity of the MINI-7 psychosis module, and provides support for use of the tool in diagnosing psychotic disorders in clinical settings in Kenya

Cross-country variations in the reporting of psychotic symptoms among sub-Saharan African adults: A psychometric evaluation of the Psychosis Screening Questionnaire

Background : Self-reporting of psychotic symptoms varies significantly between cultures and ethnic groups. Yet, limited validated screening instruments are available to capture such differences in the African continent. Methodology : Among 9,059 individuals participating as controls in a multi-country case–control study of the genetic causes of psychosis, we evaluated the psychometric properties of the Psychosis Screening Questionnaire (PSQ). We applied multi-group confirmatory factor analysis and item response theory to assess item parameters. Results : The overall positive endorsement of at least one item assessing psychotic symptoms on the PSQ was 9.7%, with variability among countries (Uganda 13.7%, South Africa 11%, Kenya 10.2%, and Ethiopia 2.8%). A unidimensional model demonstrated good fit for the PSQ (root mean square error of approximation = 0.009; comparative fit index = 0.997; and Tucker-Lewis Index = 0.995). Hypomania had the weakest association with single latent factor (standardized factor loading 0.62). Sequential multi-group confirmatory factor analysis demonstrated that PSQ items were measured in equivalent ways across the four countries. PSQ items gave more information at higher levels of psychosis, with hypomania giving the least discriminating information. Limitations : Participants were recruited from general medical facilities, so findings may not be generalizable to the general population. Conclusion : The PSQ demonstrated a unidimensional factor structure in these samples. Items were measured equivalently across all study settings, suggesting that differences in prevalence of psychotic symptoms between countries were less likely to represent measurement artifact. The PSQ is more reliable in screening for psychosis in individuals with higher degrees of psychotic experiences—hypomania excluded—and might decrease the false-positive rate from mild nonspecific psychotic experiences

Metabolic effect of an exogenous gene on transgenic beauveria bassiana using liquid chromatography-mass spectrometry-based metabolomics

Journal of Agricultural and Food Chemistry, 61(28), pages 7008-7017, 2013The article of record as published may be found at http://dx.doi.org/10.1021/jf401703bGenetic modification of Beauveria bassiana with the scorpion neurotoxin aaIT gene can distinctly increase its insecticidal activity, whereas the effect of this exogenous gene on the metabolism of B. bassiana is unknown until now. Thus, we investigate the global metabolic profiling of mycelia and conidia of transgenic and wild-type B. bassiana by liquid chromatography−mass spectrometry (LC−MS). Principal component analysis (PCA) and orthogonal projection to latent structure discriminant analysis (OPLS-DA) reveal clear discrimination of wild-type mycelia and conidia from transgenic mycelia and conidia. The decrease of glycerophospholipids, carnitine, and fatty acids and the increase of oxylipins, glyoxylate, pyruvic acid, acetylcarnitine, fumarate, ergothioneine, and trehalose in transgenic mycelia indicate the enhanced oxidative reactions. In contrast, most metabolites related to oxidative stress are not altered significantly in conidia, which implies that there will be no significant oxidative stress reaction when the aaIT gene is quiescent in cells