Reliability and Precision of the Nana Protocol to Assess Body Composition Using Dual Energy X-ray Absorptiometry

The Nana positioning protocol is widely used to position participants to minimize technical error when undertaking body composition scanning and analysis with a Dual energy X-Ray absorptiometry (DXA) machine. Once biological and technical errors are accounted for, the only variation in test–retest results is from statistical fluctuation or machine error. Therefore, the aim of this study is to assess the test–retest reliability of the Nana positioning protocol and establish the smallest real difference percentage (SRD%). A gender-balanced group of 30 participants (15 males, 15 females) underwent two scans in succession using the Nana positioning protocol, with repositioning between scans. Percentage change in mean with typical error, Intraclass Correlation Coefficients (ICC), and standard error measurement percentage (SEM%) were used to identify the test–retest reliability and error rate of these protocols. Additionally, SRD% was calculated to assess the point at which clinically important changes occurred in a participant. The reliabilities of the whole body and regional scans were excellent. Percentage change in mean ranged between 0.00% and 0.23%. High reproducibility of the Nana positioning protocol was evident through an ICC ranging between 0.966–1.000. Additionally, typical error, SEM%, and SRD% were all low. Interestingly, fat mass was associated with the largest fluctuations observed to be associated with any of the parameters assessed. When all sources of biological and technical errors have been accounted for, the Nana positioning protocol has excellent test–retest reliability and produces low SEM% and SRD%

The Spread of the Sea Lamprey Through the Great Lakes

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141050/1/tafs0172.pd

Dual energy X-ray absorptiometry positioning protocols in assessing body composition: A systematic review of the literature:A systematic review of the literature

OBJECTIVES: To systematically identify and assess methods and protocols used to reduce technical and biological errors in published studies that have investigated reliability of dual energy X-ray absorptiometry (DXA) for assessing body composition. DESIGN: Systematic review. METHODS: Systematic searches of five databases were used to identify studies of DXA reliability. Two independent reviewers used a modified critical appraisal tool to assess their methodological quality. Data was extracted and synthesised using a level of evidence approach. Further analysis was then undertaken of methods used to decrease DXA errors (technical and biological) and so enhance DXA reliability. RESULTS: Twelve studies met eligibility criteria. Four of the articles were deemed high quality. Quality articles considered biological and technical errors when preparing participants for DXA scanning. The Nana positioning protocol was assessed to have a strong level of evidence. The studies providing this evidence indicated very high test–retest reliability (ICC 0.90–1.00 or less than 1% change in mean) of the Nana positioning protocol. The National Health and Nutrition Examination Survey (NHANES) positioning protocol was deemed to have a moderate level of evidence due to lack of high quality studies. However, the available studies found the NHANES positioning protocol had very high test–retest reliability. Evidence is limited and reported reliability has varied in papers where no specific positioning protocol was used or reported. CONCLUSIONS: Due to the strong level of evidence of excellent test–retest reliability that supports use of the Nana positioning protocol, it is recommended as the first choice for clinicians when using DXA to assess body composition

Experiences of long-term life-limiting conditions among patients and carers: what can we learn from a meta-review of systematic reviews of qualitative studies of chronic heart failure, chronic obstructive pulmonary disease and chronic kidney disease?

Objectives: To summarise and synthesise published qualitative studies to characterise factors that shape patient and caregiver experiences of chronic heart failure (CHF), chronic obstructive pulmonary disease (COPD) and chronic kidney disease (CKD).Design: Meta-review of qualitative systematic reviews and metasyntheses. Papers analysed using content analysis.Data sources: CINAHL, EMBASE, MEDLINE, PsychINFO, Scopus and Web of Science were searched from January 2000 to April 2015.Eligibility criteria for selecting studies: Systematic reviews and qualitative metasyntheses where the participants were patients, caregivers and which described experiences of care for CHF, COPD and CKD in primary and secondary care who were aged ?18?years.Results: Searches identified 5420 articles, 53 of which met inclusion criteria. Reviews showed that patients' and caregivers' help seeking and decision-making were shaped by their degree of structural advantage (socioeconomic status, spatial location, health service quality); their degree of interactional advantage (cognitive advantage, affective state and interaction quality) and their degree of structural resilience (adaptation to adversity, competence in managing care and caregiver response to demands).Conclusions: To the best of our knowledge, this is the first synthesis of qualitative systematic reviews in the field. An important outcome of this overview is an emphasis on what patients and caregivers value and on attributes of healthcare systems, relationships and practices that affect the distressing effects and consequences of pathophysiological deterioration in CHF, COPD and CKD. Interventions that seek to empower individual patients may have limited effectiveness for those who are most affected by the combined weight of structural, relational and practical disadvantage identified in this overview. We identify potential targets for interventions that could address these disadvantages.Systematic review registration number: PROSPERO CRD42014014547.<br/

The Sec14-superfamily and the regulatory interface between phospholipid metabolism and membrane trafficking

A central principle of signal transduction is the appropriate control of the process so that relevant signals can be detected with fine spatial and temporal resolution. In the case of lipid-mediated signaling, organization and metabolism of specific lipid mediators is an important aspect of such control. Herein, we review the emerging evidence regarding the roles of Sec14-like phosphatidylinositol transfer proteins (PITPs) in the action of intracellular signaling networks; particularly as these relate to membrane trafficking. Finally, we explore developing ideas regarding how Sec14-like PITPs execute biological function. As Sec14-like proteins define a protein superfamily with diverse lipid (or lipophile) binding capabilities, it is likely these under-investigated proteins will be ultimately demonstrated as a ubiquitously important set of biological regulators whose functions influence a large territory in the signaling landscape of eukaryotic cells

Minimal Model Holography for SO(2N)

A duality between the large N 't Hooft limit of the WD_N minimal model CFTs and a higher spin gravity theory on AdS3 is proposed. The gravity theory has massless spin fields of all even spins s=2,4,6,..., as well as two real scalar fields whose mass is determined by the 't Hooft parameter of the CFT. We show that, to leading order in the large N limit, the 1-loop partition function of the higher spin theory matches precisely with the CFT partition function.Comment: 21 pages, LaTe

Resolving the contributions of the membrane-bound and periplasmic nitrate reductase systems to nitric oxide and nitrous oxide production in Salmonella enterica serovar Typhimurium

The production of cytotoxic nitric oxide (NO) and conversion into the neuropharmacological agent and potent greenhouse gas nitrous oxide (N2O) is linked with anoxic nitrate catabolism by Salmonella enterica serovar Typhimurium. Salmonella can synthesize two types of nitrate reductase: a membrane-bound form (Nar) and a periplasmic form (Nap). Nitrate catabolism was studied under nitrate-rich and nitrate-limited conditions in chemostat cultures following transition from oxic to anoxic conditions. Intracellular NO production was reported qualitatively by assessing transcription of the NO-regulated genes encoding flavohaemoglobin (Hmp), flavorubredoxin (NorV) and hybrid cluster protein (Hcp). A more quantitative analysis of the extent of NO formation was gained by measuring production of N2O, the end-product of anoxic NO-detoxification. Under nitrate-rich conditions, the nar, nap, hmp, norV and hcp genes were all induced following transition from the oxic to anoxic state, and 20% of nitrate consumed in steady-state was released as N2O when nitrite had accumulated to millimolar levels. The kinetics of nitrate consumption, nitrite accumulation and N2O production were similar to those of wild-type in nitrate-sufficient cultures of a nap mutant. In contrast, in a narG mutant, the steady-state rate of N2O production was ~30-fold lower than that of the wild-type. Under nitrate-limited conditions, nap, but not nar, was up-regulated following transition from oxic to anoxic metabolism and very little N2O production was observed. Thus a combination of nitrate-sufficiency, nitrite accumulation and an active Nar-type nitrate reductase leads to NO and thence N2O production, and this can account for up to 20% of the nitrate catabolized

Successfully implementing and embedding guidelines to improve the nutrition and growth of preterm infants in neonatal intensive care: a prospective interventional study.

OBJECTIVES: We aimed to improve the nutritional care of preterm infants by developing a complex (multifaceted) intervention intended to translate current evidence into practice. We used the sociological framework of Normalization Process Theory (NPT), to guide implementation in order to embed the new practices into routine care. DESIGN: A prospective interventional study with a before and after methodology. PARTICIPANTS: Infants <30 weeks gestation or <1500 g at birth. SETTING: Tertiary neonatal intensive care unit. INTERVENTIONS: The intervention was introduced in phases: phase A (control period, January-August 2011); phase B (partial implementation; improved parenteral and enteral nutrition solutions, nutrition team, education, August-December 2011); phase C (full implementation; guidelines, screening tool, 'nurse champions', January-December 2012); phase D (postimplementation; January-June 2013). Bimonthly audits and staff NPT questionnaires were used to measure guideline compliance and 'normalisation', respectively. NPT Scores were used to guide implementation in real time. Data on nutrient intakes and growth were collected continuously. RESULTS: There were 52, 36, 75 and 35 infants in phases A, B, C and D, respectively. Mean guideline compliance exceeded 75% throughout the intervention period, peaking at 85%. Guideline compliance and NPT scores both increased over time, (r=0.92 and 0.15, p<0.03 for both), with a significant linear association between the two (r=0.21, p<0.01). There were significant improvements in daily protein intake and weight gain between birth and discharge in phases B and Ccompared with phase A (p<0.01 for all), which were sustained into phase D. CONCLUSIONS: NPT and audit results suggest that the intervention was rapidly incorporated into practice, with high guideline compliance and accompanying improvements in protein intake and weight gain. NPT appears to offer an effective way of implementing new practices such that they lead to sustained changes in care. Complex interventions based on current evidence can improve both practice and clinical outcomes

Improving the normalization of complex interventions: measure development based on normalization process theory (NoMAD): study protocol

&lt;b&gt;Background&lt;/b&gt; Understanding implementation processes is key to ensuring that complex interventions in healthcare are taken up in practice and thus maximize intended benefits for service provision and (ultimately) care to patients. Normalization Process Theory (NPT) provides a framework for understanding how a new intervention becomes part of normal practice. This study aims to develop and validate simple generic tools derived from NPT, to be used to improve the implementation of complex healthcare interventions.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Objectives&lt;/b&gt; The objectives of this study are to: develop a set of NPT-based measures and formatively evaluate their use for identifying implementation problems and monitoring progress; conduct preliminary evaluation of these measures across a range of interventions and contexts, and identify factors that affect this process; explore the utility of these measures for predicting outcomes; and develop an online users’ manual for the measures.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods&lt;/b&gt; A combination of qualitative (workshops, item development, user feedback, cognitive interviews) and quantitative (survey) methods will be used to develop NPT measures, and test the utility of the measures in six healthcare intervention settings.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Discussion&lt;/b&gt; The measures developed in the study will be available for use by those involved in planning, implementing, and evaluating complex interventions in healthcare and have the potential to enhance the chances of their implementation, leading to sustained changes in working practices