758 research outputs found
RESPOND â A patient-centred programme to prevent secondary falls in older people presenting to the emergency department with a fall: Protocol for a mixed methods programme evaluation.
Background Programme evaluations conducted alongside randomised controlled trials (RCTs) have potential to enhance understanding of trial outcomes. This paper describes a multi-level programme evaluation to be conducted alongside an RCT of a falls prevention programme (RESPOND). Objectives 1) To conduct a process evaluation in order to identify the degree of implementation fidelity and associated barriers and facilitators. 2) To evaluate the primary intended impact of the programme: participation in fall prevention strategies, and the factors influencing participation. 3) To identify the factors influencing RESPOND RCT outcomes: falls, fall injuries and ED re-presentations. Methods/ Design Five hundred and twenty eight community-dwelling adults aged 60â90 years presenting to two EDs with a fall will be recruited and randomly assigned to the intervention or standard care group. All RESPOND participants and RESPOND clinicians will be included in the evaluation. A mixed methods design will be used and a programme logic model will frame the evaluation. Data will be sourced from interviews, focus groups, questionnaires, clinician case notes, recruitment records, participant-completed calendars, hospital administrative datasets, and audio-recordings of intervention contacts. Quantitative data will be analysed via descriptive and inferential statistics and qualitative data will be interpreted using thematic analysis. Discussion The RESPOND programme evaluation will provide information about contextual and influencing factors related to the RCT outcomes. The results will assist researchers, clinicians, and policy makers to make decisions about future falls prevention interventions. Insights gained are likely to be transferable to preventive health programmes for a range of chronic conditions
Thirty Years of Cometary Spectroscopy from McDonald Observatory
We report on the results of a spectroscopic survey of 130 comets that was
conducted at McDonald observatory from 1980 through 2008. Some of the comets
were observed on only one night, while others were observed repeatedly. For 20
of these comets, no molecules were detected. For the remaining 110 comets, some
emission from CN, OH, NH, C, C, CH, and NH molecules were
observed on at least one occasion. We converted the observed molecular column
densities to production rates using a Haser (1957) model. We defined a
restricted data set of comets that had at least 3 nights of observations. The
restricted data set consists of 59 comets. We used ratios of production rates
to study the trends in the data. We find two classes of comets: typical and
carbon-chain depleted comets. Using a very strict definition of depleted
comets, requiring C \underline{and} C to both be depleted, we find
9% of our restricted data set comets to be depleted. Using a more relaxed
definition that requires only C to be below a threshold (similar to other
researchers), we find 25% of the comets are depleted. Two-thirds of the
depleted comets are Jupiter Family comets, while one-third are Long Period
comets. 37% of the Jupiter Family comets are depleted, while 18.5% of the Long
Period comets are depleted. We compare our results with other studies and find
good agreement.Comment: Accepted for Icarus; 15 figures, 9 tables (some multi-page and in
landscape mode
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The social consequences of minor innovations in construction
Innovation studies in construction focus on a desire to increase economics and efficiency at a large scale. This has resulted in a skewed perspective that sees only major corporations with substantial R&D resources, complex projects, or national interests at the heart of innovation. By adopting anthropological methods, it becomes possible to examine the two aims of this paper: to demonstrate that an accumulation of minor innovations can have significant consequences; and to show that these are inherently social rather than purely economic. Results come from fieldwork studying the improvisatory house-building practices of the Kelabit people of rural Borneo, tracing changes to the technologies used for roofing and foundations, and describes how these are mutually entangled with new social structures. The conclusion is that we should think more broadly about the forms and effects of innovation in construction, and recognise the significance of improvisation at the level of the individual or small group
Carbon isotope signatures from land snail shells: Implications for palaeovegetation reconstruction in the eastern Mediterranean
In this studywecompare carbon isotope values inmodern Helix melanostoma shell carbonate (d13Cshell) from the Gebel al-Akhdar region of Libya with carbon isotope values in H. melanostomabody tissue (d13Cbody), local vegetation (d13Cplant) and soil (d13Csoil). All vegetation in the study area followed the C3 photosynthetic pathway. However, the d13Cplant values of different species formed two distinct isotopic groups. This can be best explained by different water use efficiencies with arid adapted species having significantly more positive d13Cplant values than less water efficient species. The ranges and means of d13Cbody and d13Cplant were statistically indistinguishable from one another suggesting that d13Cbody was primarily a function of local vegetation composition. H. melanostoma d13Cshell reflected the d13Cplant of local vegetation with a positive offset between body/diet and shell of 14.5Âą 1.4â°. Therefore, in the Gebel al-Akhdar where only C3 plants are present, highermeand13C shell values likely reflect greater abundances ofwater-efficientC3 plants in the snails diet and therefore in the landscape, whilst lower mean d13Cshell values likely reflect the consumption of less water-efficient C3 plants. The distribution of these plants is in turn affected by environmental factors such as rainfall. These findings can be applied to archaeological and geological shell deposits to reconstruct late Pleistocene to Holocene vegetation change in the southeast Mediterranean
A two-species model of a two-dimensional sandpile surface: a case of asymptotic roughening
We present and analyze a model of an evolving sandpile surface in (2 + 1)
dimensions where the dynamics of mobile grains ({\rho}(x, t)) and immobile
clusters (h(x, t)) are coupled. Our coupling models the situation where the
sandpile is flat on average, so that there is no bias due to gravity. We find
anomalous scaling: the expected logarithmic smoothing at short length and time
scales gives way to roughening in the asymptotic limit, where novel and
non-trivial exponents are found.Comment: 7 Pages, 6 Figures; Granular Matter, 2012 (Online
Higher twists and extractions from the NNLO QCD analysis of the CCFR data for structure function
A detailed next-to-next-to-leading order (NNLO) QCD analysis is performed for
the experimental data of the CCFR collaboration for the structure
function. Theoretical ambiguities of the results of our NNLO fits are estimated
by application of the Pad\'e resummation technique and variation of the
factorization and renormalization scales. The NNLO and NLO
-matching conditions are used. In the process of the fits we are
taking into account of twist-4 -terms. We found that the amplitude of
the -shape of the twist-4 factor is decreasing in NLO and NNLO, though some
remaining twist-4 structure seems to retain in NNLO in the case when
statistical uncertainties are taken into account. The question of the stability
of these results to the application of the [0/2] Pad\'e resummation technique
is considered. Our NNLO results for values, extracted from the
CCFR data, are provided the twist-4 contributions are fixed through the
infrared renormalon model and provided the twist-4 terms are considered as
free parameters.Comment: 33 pages LaTeX, 3 ps figures; minor misprints are eliminated, 2 new
referencies are added; accepted for publication in Nucl. Phys.
Changing patterns of eastern Mediterranean shellfish exploitation in the Late Glacial and Early Holocene: Oxygen isotope evidence from gastropod in Epipaleolithic to Neolithic human occupation layers at the Haua Fteah cave, Libya
The seasonal pattern of shellfish foraging at the archaeological site of Haua Fteah in the Gebel Akhdar, Libya was investigated from the Epipaleolithic to the Neolithic via oxygen isotope (d18O) analyses of the topshell Phorcus (Osilinus) turbinatus. To validate this species as faithful year-round palaeoenvironmental recorder, the intra-annual variability of d18O in modern shells and sea water was analysed and compared with measured sea surface temperature (SST). The shells were found to be good candidates for seasonal shellfish forging studies as they preserve nearly the complete annual SST cycle in their shell d18O with minimal slowing or stoppage of growth. During the terminal Pleistocene Early Epipaleolithic (locally known as the Oranian, with modeled dates of 17.2-12.5 ka at 2sigma probability, Douka et al., 2014), analysis of archaeological specimens indicates that shellfish were foraged year-round. This complements other evidence from the archaeological record that shows that the cave was more intensively occupied in this period than before or afterwards. This finding is significant as the period of the Oranian was the coldest and driest phase of the last glacial cycle in the Gebel Akhdar, adding weight to the theory that the Gebel Akhdar may have served as a refugium for humans in North Africa during times of global climatic extremes. Mollusc exploitation in the Latest Pleistocene and Early Holocene, during the Late Epipaleolithic (locally known as the Capsian, c. 12.7 to 9 ka) and the Neolithic (c. 8.5 to 5.4 ka), occurred predominantly during winter. Other evidence from these archaeological phases shows that hunting activities occurred during the warmer months. Therefore, the timing of Holocene shellfish exploitation in the Gebel Akhdar may have been influenced by the seasonal availability of other resources at these times and possibly shellfish were used as a dietary supplement when other foods were less abundant
Metagenomics combined with activity-based proteomics point to gut bacterial enzymes that reactivate mycophenolate
Mycophenolate mofetil (MMF) is an important immunosuppressant prodrug prescribed to prevent organ transplant rejection and to treat autoimmune diseases. MMF usage, however, is limited by severe gastrointestinal toxicity that is observed in approximately 45% of MMF recipients. The active form of the drug, mycophenolic acid (MPA), undergoes extensive enterohepatic recirculation by bacterial beta-glucuronidase (GUS) enzymes, which reactivate MPA from mycophenolate glucuronide (MPAG) within the gastrointestinal tract. GUS enzymes demonstrate distinct substrate preferences based on their structural features, and gut microbial GUS enzymes that reactivate MPA have not been identified. Here, we compare the fecal microbiomes of transplant recipients receiving MMF to healthy individuals using shotgun metagenomic sequencing. We find that neither microbial composition nor the presence of specific structural classes of GUS genes are sufficient to explain the differences in MPA reactivation measured between fecal samples from the two cohorts. We next employed a GUS-specific activity-based chemical probe and targeted metaproteomics to identify and quantify the GUS proteins present in the human fecal samples. The identification of specific GUS enzymes was improved by using the metagenomics data collected from the fecal samples. We found that the presence of GUS enzymes that bind the flavin mononucleotide (FMN) is significantly correlated with efficient MPA reactivation. Furthermore, structural analysis identified motifs unique to these FMN-binding GUS enzymes that provide molecular support for their ability to process this drug glucuronide. These results indicate that FMN-binding GUS enzymes may be responsible for reactivation of MPA and could be a driving force behind MPA-induced GI toxicity.Bio-organic Synthesi
Prenatal cortisol exposure impairs adrenal function but not glucose metabolism in adult sheep
Adverse environmental conditions before birth are known to program adult metabolic and endocrine phenotype in several species. However, whether increments in fetal cortisol
concentrations of the magnitude commonly seen in these conditions can cause
developmental programming remains unknown. Thus, this study investigated the outcome
of physiological increases in fetal cortisol concentrations on glucose-insulin dynamics and
pituitary-adrenal function in adult sheep. Compared to saline treatment, intravenous fetal
cortisol infusion for 5 days in late gestation did not affect birthweight but increased lamb
body weight at 1-2 weeks after birth. Adult glucose dynamics, insulin sensitivity and insulin
secretion were unaffected by prenatal cortisol overexposure, assessed by glucose tolerance
tests, hyperinsulinaemic-euglycaemic clamps and acute insulin administration. In contrast,
prenatal cortisol infusion induced adrenal hypo-responsiveness in adulthood with
significantly reduced cortisol responses to insulin-induced hypoglycaemia and exogenous
adrenocorticotropic hormone (ACTH) administration relative to saline treatment. The area of
adrenal cortex expressed as a percentage of the total cross-sectional area of the adult adrenal
gland was also lower after prenatal cortisol than saline infusion. In adulthood, basal
circulating ACTH but not cortisol concentrations were significantly higher in the cortisol than
saline treated group. The results show that cortisol overexposure before birth programs
pituitary-adrenal development with consequences for adult stress responses. Physiological
variations in cortisol concentrations before birth may, therefore, have an important role in
determining adult phenotypical diversity and adaptability to environmental challenges
A Model for the Development of the Rhizobial and Arbuscular Mycorrhizal Symbioses in Legumes and Its Use to Understand the Roles of Ethylene in the Establishment of these two Symbioses
We propose a model depicting the development of nodulation and arbuscular mycorrhizae. Both processes are dissected into many steps, using Pisum sativum L. nodulation mutants as a guideline. For nodulation, we distinguish two main developmental programs, one epidermal and one cortical. Whereas Nod factors alone affect the cortical program, bacteria are required to trigger the epidermal events. We propose that the two programs of the rhizobial symbiosis evolved separately and that, over time, they came to function together. The distinction between these two programs does not exist for arbuscular mycorrhizae development despite events occurring in both root tissues. Mutations that affect both symbioses are restricted to the epidermal program. We propose here sites of action and potential roles for ethylene during the formation of the two symbioses with a specific hypothesis for nodule organogenesis. Assuming the epidermis does not make ethylene, the microsymbionts probably first encounter a regulatory level of ethylene at the epidermisâoutermost cortical cell layer interface. Depending on the hormone concentrations there, infection will either progress or be blocked. In the former case, ethylene affects the cortex cytoskeleton, allowing reorganization that facilitates infection; in the latter case, ethylene acts on several enzymes that interfere with infection thread growth, causing it to abort. Throughout this review, the difficulty of generalizing the roles of ethylene is emphasized and numerous examples are given to demonstrate the diversity that exists in plants
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