1,001 research outputs found

    The portion size effect : women demonstrate an awareness of eating more than intended when served larger than normal portions

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    Large portion sizes lead to increased intake. Some studies suggest that individuals are unaware that they consume more when served larger portions. In a between-subjects design we asked female participants (N = 48) how much pasta and tomato sauce they intended to consume for lunch prior to eating. We then provided a smaller or a larger portion of the same food and invited participants to self-serve a portion into a second bowl (same size in both conditions). After eating until comfortably full, participants were shown an image of the amount they had selected at the beginning of the meal. They were then asked whether they perceived having eaten more or less than this amount, and by how much more or less they had eaten. In total 46 responses were analysed. Of the participants who received the large portion and who ate more than intended, 77% (p = .029) correctly identified eating more. However, when participants were asked to indicate by how much they had eaten above or below their intended amount, those who ate more after receiving a larger portion underestimated their intake by 25% (p = .003). These findings suggest that greater intake from a larger portion is associated with an awareness of having eaten a large quantity combined with a failure to register the actual amount consumed (in the direction of underestimation). The latter might be attributed to an error associated with the visual estimation of volume

    A prospective randomized trial of fk506 versus cyclosporine after human pulmonary transplantation

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    We have conducted a unique prospective randomized study to compare the effect of PK506 and cyclosporine (CsA) as the principal immunosuppressive agents after pulmonary transplantation. Between October 1991 and March 1993, 74 lung transplants (35 single lung transplants [SLT], 39 bilateral lung transplant [BLT]) were performed on 74 recipients who were randomly assigned to receive either FK or CsA. Thirty-eight recipients (19 SLT, 19 BLT) received FK and 36 recipients (16 SLT, 20 BLT) received CsA. Recipients receiving FK or CsA were similar in age, gender, preoperative New York Heart Association functional class, and underlying disease. Acute rejection (ACR) was assessed by clinical, radiographic, and histologic criteria. ACR was treated with methylprednisolone, 1 g i.v./day, for three days or rabbit antithymocyte globulin if steroid-resistant.During the first 30 days after transplant, one patient in the FK group died of cerebral edema, while two recipients treated with CsA died of bacterial pneumonia (1) and cardiac arrest (1) (P=NS). Although one-year survival was similar between the groups, the number of recipients free from ACR in the FK group was significantly higher as compared with the CsA group (P<0.05). Bacterial and viral pneumonias were the major causes of late graft failure in both groups. The mean number of episodes of ACR/ 100 patient days was significantly fewer in the FK group (1.2) as compared with the CsA group (2.0) (P<0.05). While only one recipient (1/36=3%) in the group treated with CsA remained free from ACR within 120 days of transplantation, 13% (5/38) of the group treated with FK remained free from ACR during this interval (P<0.05). The prevalence of bacterial infection in the CsA group was 1.5 episodes/100 patient days and 0.6 episodes/100 patient days in the FK group. The prevalence of cytomegaloviral and fungal infection was similar in both groups.Although the presence of bacterial, fungal, and viral infections was similar in the two groups, ACR occurred less frequently in the FK-treated group as compared with the CsA-treated group in the early postoperative period (<90 days). Early graft survival at 30 days was similar in the two groups, but intermediate graft survival at 6 months was better in the FK group as compared with the CsA group. © 1994 by Williams and Wilkins

    Rising CO2 and warming reduce global canopy deman for nitrogen

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    Nitrogen (N) limitation has been considered as a constraint on terrestrial carbon uptake in response to rising CO2 and climate change. By extension, it has been suggested that declining carboxylation capacity (Vcmax) and leaf N content in enhanced-CO2 experiments and satellite records signify increasing N limitation of primary production. We predicted Vcmax using the coordination hypothesis, and estimated changes in leaf-level photosynthetic N for 1982–2016 assuming proportionality with leaf-level Vcmax at 25˚C. Whole-canopy photosynthetic N was derived using satellite-based leaf area index (LAI) data and an empirical extinction coefficient for Vcmax, and converted to annual N demand using estimated leaf turnover times. The predicted spatial pattern of Vcmax shares key features with an independent reconstruction from remotely-sensed leaf chlorophyll content. Predicted leaf photosynthetic N declined by 0.27 % yr-1, while observed leaf (total) N declined by 0.2–0.25 % yr-1. Predicted global canopy N (and N demand) declined from 1996 onwards, despite increasing LAI. Leaf-level responses to rising CO2, and to a lesser extent temperature, may have reduced the canopy requirement for N by more than rising LAI has increased it. This finding provides an alternative explanation for declining leaf N that does not depend on increasing N limitation

    Global datasets of leaf photosynthetic capacity for ecological and earth system research

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    The maximum rate of Rubisco carboxylation (Vcmax) determines leaf photosynthetic capacity and is a key parameter for estimating the terrestrial carbon cycle, but its spatial information is lacking, hindering global ecological research. Here, we convert leaf chlorophyll content (LCC) retrieved from satellite data to Vcmax, based on plants’ optimal distribution of nitrogen between light harvesting and carboxylation pathways. We also derive Vcmax from satellite (GOME-2) observations of sun-induced chlorophyll fluorescence (SIF) as a proxy of leaf photosynthesis using a data assimilation technique. These two independent global Vcmax products agree well (r 2=0.79, RMSE=15.46 μmol m-2 s -1 25 , P<0.001) and compare well with 3672 ground-based measurements (r2=0.68, RMSE=13.55 μmol m-2 s -1 and P<0.001 for SIF; r2=0.55, RMSE=17.55 μmol m-2 s -1 and P<0.001 for LCC). The LCC-derived Vcmax product is also used to constrain the retrieval of Vcmax from TROPOMI SIF data to produce an optimized Vcmax product using both SIF and LCC information. The global distributions of these products are compatible with Vcmax computed from an ecological optimality theory using meteorological variables, but importantly reveal additional information on the influence of land cover, irrigation, soil pH and leaf nitrogen on leaf photosynthetic capacity. These satellite-based approaches and spatial Vcmax products are primed to play a major role in global ecosystem research. The three remote sensing Vcmax products based on SIF, LCC and SIF+LCC are available at https://doi.org/10.5281/zenodo.6466968 (Chen et al., 2020) and the code for implementing the ecological optimality theory is available at https://github.com/SmithEcophysLab/optimal_vcmax_R (Smith, 2020)

    Internal construct validity of the Warwick-Edinburgh Mental Well-being Scale (WEMWBS): a Rasch analysis using data from the Scottish Health Education Population Survey

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    Background: The Warwick-Edinburgh Mental Well-Being Scale (WEMWBS) was developed to meet demand for instruments to measure mental well-being. It comprises 14 positively phrased Likert-style items and fulfils classic criteria for scale development. We report here the internal construct validity of WEMWBS from the perspective of the Rasch measurement model. Methods: The model was applied to data collected from 779 respondents in Wave 12 (Autumn 2006) of the Scottish Health Education Population Survey. Respondents were aged 16–74 (average 41.9) yrs. Results: Initial fit to model expectations was poor. The items 'I've been feeling good about myself', 'I've been interested in new things' and 'I've been feeling cheerful' all showed significant misfit to model expectations, and were deleted. This led to a marginal improvement in fit to the model. After further analysis, more items were deleted and a strict unidimensional seven item scale (the Short Warwick Edinburgh Mental Well-Being Scale (SWEMWBS)) was resolved. Many items deleted because of misfit with model expectations showed considerable bias for gender. Two retained items also demonstrated bias for gender but, at the scale level, cancelled out. One further retained item 'I've been feeling optimistic about the future' showed bias for age. The correlation between the 14 item and 7 item versions was 0.954. Given fit to the Rasch model, and strict unidimensionality, SWEMWBS provides an interval scale estimate of mental well-being. Conclusion: A short 7 item version of WEMWBS was found to satisfy the strict unidimensionality expectations of the Rasch model, and be largely free of bias. This scale, SWEMWBS, provides a raw score-interval scale transformation for use in parametric procedures. In terms of face validity, SWEMWBS presents a more restricted view of mental well-being than the 14 item WEMWBS, with most items representing aspects of psychological and eudemonic well-being, and few covering hedonic well-being or affect. However, robust measurement properties combined with brevity make SWEMWBS preferable to WEMWBS at present for monitoring mental well-being in populations. Where face validity is an issue there remain arguments for continuing to collect data on the full 14 item WEMWBS

    The microaerophilic microbiota of de-novo paediatric inflammatory bowel disease: the BISCUIT study

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    &lt;p&gt;Introduction: Children presenting for the first time with inflammatory bowel disease (IBD) offer a unique opportunity to study aetiological agents before the confounders of treatment. Microaerophilic bacteria can exploit the ecological niche of the intestinal epithelium; Helicobacter and Campylobacter are previously implicated in IBD pathogenesis. We set out to study these and other microaerophilic bacteria in de-novo paediatric IBD.&lt;/p&gt; &lt;p&gt;Patients and Methods: 100 children undergoing colonoscopy were recruited including 44 treatment naïve de-novo IBD patients and 42 with normal colons. Colonic biopsies were subjected to microaerophilic culture with Gram-negative isolates then identified by sequencing. Biopsies were also PCR screened for the specific microaerophilic bacterial groups: Helicobacteraceae, Campylobacteraceae and Sutterella wadsworthensis.&lt;/p&gt; &lt;p&gt;Results: 129 Gram-negative microaerophilic bacterial isolates were identified from 10 genera. The most frequently cultured was S. wadsworthensis (32 distinct isolates). Unusual Campylobacter were isolated from 8 subjects (including 3 C. concisus, 1 C. curvus, 1 C. lari, 1 C. rectus, 3 C. showae). No Helicobacter were cultured. When comparing IBD vs. normal colon control by PCR the prevalence figures were not significantly different (Helicobacter 11% vs. 12%, p = 1.00; Campylobacter 75% vs. 76%, p = 1.00; S. wadsworthensis 82% vs. 71%, p = 0.312).&lt;/p&gt; &lt;p&gt;Conclusions: This study offers a comprehensive overview of the microaerophilic microbiota of the paediatric colon including at IBD onset. Campylobacter appear to be surprisingly common, are not more strongly associated with IBD and can be isolated from around 8% of paediatric colonic biopsies. S. wadsworthensis appears to be a common commensal. Helicobacter species are relatively rare in the paediatric colon.&lt;/p&gt

    The microwave background temperature at the redshift of 2.33771

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    The Cosmic Microwave Background radiation is a fundamental prediction of Hot Big Bang cosmology. The temperature of its black-body spectrum has been measured at the present time, TCMBR,0T_{\rm CMBR,0} = 2.726±\pm 0.010 K, and is predicted to have been higher in the past. At earlier time, the temperature can be measured, in principle, using the excitation of atomic fine structure levels by the radiation field. All previous measurements however give only upper limits as they assume that no other significant source of excitation is present. Here we report the detection of absorption from the first {\sl and} second fine-structure levels of neutral carbon atoms in an isolated remote cloud at a redshift of 2.33771. In addition, the unusual detection of molecular hydrogen in several rotational levels and the presence of ionized carbon in its excited fine structure level make the absorption system unique to constrain, directly from observation, the different excitation processes at play. It is shown for the first time that the cosmic radiation was warmer in the past. We find 6.0 < T_{\rm CMBR} < 14 K at z = 2.33771 when 9.1 K is expected in the Hot Big Bang cosmology.Comment: 20 pages, 5 figures, accepted for publication in Nature, Press embargo until 1900 hrs London time (GMT) on 20 Dec 200

    Multicystic encephalomalacia as an end-stage finding in abusive head trauma

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    Abusive head trauma (AHT) is one of the most severe forms of physical child abuse. If a child initially survives severe AHT the neurological outcome can be poor. In recent years several children were seen who developed multicystic encephalomalacia (MCE) after documented severe AHT. A search of the Netherlands Forensic Institute database in The Hague was performed. Inclusion criteria were cases of AHT between 1999 and 2010 where the child was under the age of 1 year old at the time of trauma. Trauma mechanism and radiological information were collected. Five children, three boys and two girls (mean age 57 days, range 8–142 days) who developed cystic encephalomalacia after inflicted traumatic brain injury were included. Survival ranged from 27 to 993 days. In all cases judicial autopsy was performed. All cases came before court and in each case child abuse was considered to be proven. In two cases the perpetrator confessed, during police interrogation, to shaking of the child only. Although a known serious outcome, this is one of the few reports on MCE as a result of AHT. In all cases the diagnosis was confirmed at autopsy

    Study of the chemotactic response of multicellular spheroids in a microfluidic device

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    YesWe report the first application of a microfluidic device to observe chemotactic migration in multicellular spheroids. A microfluidic device was designed comprising a central microchamber and two lateral channels through which reagents can be introduced. Multicellular spheroids were embedded in collagen and introduced to the microchamber. A gradient of fetal bovine serum (FBS) was established across the central chamber by addition of growth media containing serum into one of the lateral channels. We observe that spheroids of oral squamous carcinoma cells OSC–19 invade collectively in the direction of the gradient of FBS. This invasion is more directional and aggressive than that observed for individual cells in the same experimental setup. In contrast to spheroids of OSC–19, U87-MG multicellular spheroids migrate as individual cells. A study of the exposure of spheroids to the chemoattractant shows that the rate of diffusion into the spheroid is slow and thus, the chemoattractant wave engulfs the spheroid before diffusing through it.This work has been supported by National Research Program of Spain (DPI2011-28262-c04-01) and by the project "MICROANGIOTHECAN" (CIBERBBN, IMIBIC and SEOM). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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