383 research outputs found
Goal conflicts in long-term cropping system trials - the example of carrots
Agricultural research on multiple cropping systems in parallel increases the potential for knowledge transfer between organic and conventional systems. This project aims to develop cropping systems towards greater sustainability through work in long-term trials that have a unique opportunity to contribute to a holistic research perspective. Data on the fourth crop rotation (2007-2012) are now being compiled. This paper presents preliminary results from cultivation of carrots as an example to demonstrate goal conflicts in organic and conventional systems between good nutrient management and good economy on one hand and nematode control and intensive cropping systems (good short-term economy) on the other. Good productivity and sustainable production levels are major overall goals in the project. The conclusion is that more research on nematode susceptibility and propagating at different crops and varieties is very important
Water Dynamics at Protein Interfaces: Ultrafast Optical Kerr Effect Study
The behavior of water molecules surrounding a protein can have an important bearing on its structure and function. Consequently, a great deal of attention has been focused on changes in the relaxation dynamics of water when it is located at the protein surface. Here we use the ultrafast optical Kerr effect to study the H-bond structure and dynamics of aqueous solutions of proteins. Measurements are made for three proteins as a function of concentration. We find that the water dynamics in the first solvation layer of the proteins are slowed by up to a factor of 8 in comparison to those in bulk water. The most marked slowdown was observed for the most hydrophilic protein studied, bovine serum albumin, whereas the most hydrophobic protein, trypsin, had a slightly smaller effect. The terahertz Raman spectra of these protein solutions resemble those of pure water up to 5 wt % of protein, above which a new feature appears at 80 cm–1, which is assigned to a bending of the protein amide chain
Is the meiofauna a good indicator for climate change and anthropogenic impacts?
Our planet is changing, and one of the most pressing challenges facing the scientific community revolves around understanding how ecological communities respond to global changes. From coastal to deep-sea ecosystems, ecologists are exploring new areas of research to find model organisms that help predict the future of life on our planet. Among the different categories of organisms, meiofauna offer several advantages for the study of marine benthic ecosystems. This paper reviews the advances in the study of meiofauna with regard to climate change and anthropogenic impacts. Four taxonomic groups are valuable for predicting global changes: foraminifers (especially calcareous forms), nematodes, copepods and ostracods. Environmental variables are fundamental in the interpretation of meiofaunal patterns and multistressor experiments are more informative than single stressor ones, revealing complex ecological and biological interactions. Global change has a general negative effect on meiofauna, with important consequences on benthic food webs. However, some meiofaunal species can be favoured by the extreme conditions induced by global change, as they can exhibit remarkable physiological adaptations. This review highlights the need to incorporate studies on taxonomy, genetics and function of meiofaunal taxa into global change impact research
Perceived annoyance and asthmatic symptoms in relation to vehicle exhaust levels outside home: a cross-sectional study
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: Exhaust emissions from vehicles is a well known problem with both epidemiological and experimental studies showing increasing adverse health effects with elevating levels. Many of the studies concerning vehicle exhausts and health are focused on health outcomes where the proportion attributed to exhaust is low, while there is less information on early and more frequent subjective indicators of adverse effects. Methods: The primary aim of this study was to study perceived annoyance in relation to vehicle exhaust concentrations using modelled levels of nitrogen dioxide outside the home as an indicator with high spatial resolution. Almost 2800 persons in a random sample from three Swedish cities (Umea, Uppsala and Gothenburg) responded to our questionnaire. Questions were asked to determine the degree of annoyance related to vehicle exhausts and also the prevalence of irritating and asthmatic symptoms. Exposure was described for each participants home address by meteorological dispersion models with a 50 meter resolution. Results: We found a significant increase of peoples ' self-assessed annoyance with rising levels of NO2. The odds of being very annoyed by vehicle exhausts increased by 14 % per 1 µg/m3 increas
Perception of improvement after orthognathic surgery: the important variables affecting patient satisfaction
PURPOSE: We evaluated which factors affect patient satisfaction and if patient expectations were fulfilled after orthognathic surgery. METHODS: Questionnaires consisting of 14 questions were given 1 year after bimaxillary osteotomy for class-III correction to subjects. Six questions were answered using an 11-point rating scale based on a visual analog scale (VAS; 0 = poor; 10 = excellent). Also included were seven closed-form questions with yes/no answers, as well as one open question for 'further remarks'. Sagittal and vertical cephalometric parameters were determined on postoperative cephalograms. RESULTS: Seventy-seven patients (37 females, 40 males; mean age, 23.4 +/- 4.9 (SD) years) responded. The intention to undergo surgery only for aesthetic improvement was noted in 11.9% of patients; only improvement of chewing function in 15.5%; both in 71.4%; and none/don't know in 2.6%. Postoperative satisfaction was rated (in means) with 8.13 +/- 1.97 on VAS and correlated significantly with the opinions of friends and relatives. Facial aesthetics was rated 5.6 +/- 1.2 before surgery and 8.1 +/- 1.5 after surgery (p = 0.04). Preoperative chewing function was rated 5.65 +/- 1.8 and 8.03 +/- 1.51 after surgery (p = 0.014). TMJ disorders or hypoesthesia had no negative impacts. Cephalometric analyses revealed a significantly lower SNB (75.3 degrees +/- 2.7 degrees ; p = 0.033) in patients rating lower than grade 7 for overall satisfaction. For SNA and ArGoMe, no significant differences were observed. CONCLUSION: The most distinctive factors for patient satisfaction after orthognathic surgery were chewing function and facial aesthetics with respect to the lower face. Function, aesthetics, and even psychological aspects should be considered equally when planning surgery
Pain relief and safety after major surgery A prospective study of epidural and intravenous analgesia in 2696 patients.
Variation of NO2 and NOx concentrations between and within 36 European study areas: Results from the ESCAPE study
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Systemic Inflammation in Preclinical Ulcerative Colitis
Background & Aims: Preclinical ulcerative colitis is poorly defined. We aimed to characterize the preclinical systemic inflammation in ulcerative colitis, using a comprehensive set of proteins. Methods: We obtained plasma samples biobanked from individuals who developed ulcerative colitis later in life (n = 72) and matched healthy controls (n = 140) within a population-based screening cohort. We measured 92 proteins related to inflammation using a proximity extension assay. The biologic relevance of these findings was validated in an inception cohort of patients with ulcerative colitis (n = 101) and healthy controls (n = 50). To examine the influence of genetic and environmental factors on these markers, a cohort of healthy twin siblings of patients with ulcerative colitis (n = 41) and matched healthy controls (n = 37) were explored. Results: Six proteins (MMP10, CXCL9, CCL11, SLAMF1, CXCL11 and MCP-1) were up-regulated (P < .05) in preclinical ulcerative colitis compared with controls based on both univariate and multivariable models. Ingenuity Pathway Analyses identified several potential key regulators, including interleukin-1ß, tumor necrosis factor, interferon-gamma, oncostatin M, nuclear factor-¿B, interleukin-6, and interleukin-4. For validation, we built a multivariable model to predict disease in the inception cohort. The model discriminated treatment-naïve patients with ulcerative colitis from controls with leave-one-out cross-validation (area under the curve = 0.92). Consistently, MMP10, CXCL9, CXCL11, and MCP-1, but not CCL11 and SLAMF1, were significantly up-regulated among the healthy twin siblings, even though their relative abundances seemed higher in incident ulcerative colitis. Conclusions: A set of inflammatory proteins are up-regulated several years before a diagnosis of ulcerative colitis. These proteins were highly predictive of an ulcerative colitis diagnosis, and some seemed to be up-regulated already at exposure to genetic and environmental risk factors. © 2021 The Author
On the Use of Accelerated Molecular Dynamics to Enhance Configurational Sampling in Ab Initio Simulations
We have implemented the accelerated molecular dynamics approach (Hamelberg, D.; Mongan, J.; McCammon, J. A. J. Chem. Phys. 2004, 120 (24), 11919) in the framework of ab initio MD (AIMD). Using three simple examples, we demonstrate that accelerated AIMD (A-AIMD) can be used to accelerate solvent relaxation in AIMD simulations and facilitate the detection of reaction coordinates: (i) We show, for one cyclohexane molecule in the gas phase, that the method can be used to accelerate the rate of the chair-to-chair interconversion by a factor of ∼1 × 105, while allowing for the reconstruction of the correct canonical distribution of low-energy states; (ii) We then show, for a water box of 64 H2O molecules, that A-AIMD can also be used in the condensed phase to accelerate the sampling of water conformations, without affecting the structural properties of the solvent; and (iii) The method is then used to compute the potential of mean force (PMF) for the dissociation of Na−Cl in water, accelerating the convergence by a factor of ∼3−4 compared to conventional AIMD simulations.(2) These results suggest that A-AIMD is a useful addition to existing methods for enhanced conformational and phase-space sampling in solution. While the method does not make the use of collective variables superfluous, it also does not require the user to define a set of collective variables that can capture all the low-energy minima on the potential energy surface. This property may prove very useful when dealing with highly complex multidimensional systems that require a quantum mechanical treatment
The changes of oral health-related quality of life and satisfaction after surgery-first orthognathic approach: a longitudinal prospective study
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