908 resultados para Environmental objective function


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In several regions of the world, climate change is expected to have severe impacts on agricultural systems. Changes in land management are one way to adapt to future climatic conditions, including land-use changes and local adjustments of agricultural practices. In previous studies, options for adaptation have mostly been explored by testing alternative scenarios. Systematic explorations of land management possibilities using optimization approaches were so far mainly restricted to studies of land and resource management under constant climatic conditions. In this study, we bridge this gap and exploit the benefits of multi-objective regional optimization for identifying optimum land management adaptations to climate change. We design a multi-objective optimization routine that integrates a generic crop model and considers two climate scenarios for 2050 in a meso-scale catchment on the Swiss Central Plateau with already limited water resources. The results indicate that adaptation will be necessary in the study area to cope with a decrease in productivity by 0–10 %, an increase in soil loss by 25–35 %, and an increase in N-leaching by 30–45 %. Adaptation options identified here exhibit conflicts between productivity and environmental goals, but compromises are possible. Necessary management changes include (i) adjustments of crop shares, i.e. increasing the proportion of early harvested winter cereals at the expense of irrigated spring crops, (ii) widespread use of reduced tillage, (iii) allocation of irrigated areas to soils with low water-retention capacity at lower elevations, and (iv) conversion of some pre-alpine grasslands to croplands.

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Diseases are believed to arise from dysregulation of biological systems (pathways) perturbed by environmental triggers. Biological systems as a whole are not just the sum of their components, rather ever-changing, complex and dynamic systems over time in response to internal and external perturbation. In the past, biologists have mainly focused on studying either functions of isolated genes or steady-states of small biological pathways. However, it is systems dynamics that play an essential role in giving rise to cellular function/dysfunction which cause diseases, such as growth, differentiation, division and apoptosis. Biological phenomena of the entire organism are not only determined by steady-state characteristics of the biological systems, but also by intrinsic dynamic properties of biological systems, including stability, transient-response, and controllability, which determine how the systems maintain their functions and performance under a broad range of random internal and external perturbations. As a proof of principle, we examine signal transduction pathways and genetic regulatory pathways as biological systems. We employ widely used state-space equations in systems science to model biological systems, and use expectation-maximization (EM) algorithms and Kalman filter to estimate the parameters in the models. We apply the developed state-space models to human fibroblasts obtained from the autoimmune fibrosing disease, scleroderma, and then perform dynamic analysis of partial TGF-beta pathway in both normal and scleroderma fibroblasts stimulated by silica. We find that TGF-beta pathway under perturbation of silica shows significant differences in dynamic properties between normal and scleroderma fibroblasts. Our findings may open a new avenue in exploring the functions of cells and mechanism operative in disease development.

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OBJECTIVE The purpose of this study was to compare clinical outcomes and sexual function between transvaginal and transabdominal repairs of vesicovaginal fistulae (VVF). STUDY DESIGN Participants (99 women with VVF at a tertiary referral center) were treated with urinary catheterization for 12 weeks and, if the procedure was unsuccessful, underwent repair either the transvaginal (Latzko) or transabdominal technique. Objective clinical parameters were analyzed; subjective outcomes were recorded prospectively at the 6-month follow-up examination with the use of the female sexual function index to evaluate sexual function and the visual analogue scale to measure general disturbance by the fistula. RESULTS After bladder drainage for 12 weeks, 8 patients had spontaneous fistula closure. Demographic variables were similar in the transvaginal (n = 60) and transabdominal (n = 31) repair groups. The transvaginal procedure showed significantly shorter operation times, less blood loss, and shorter hospital stay. Continence rates 6 months after surgery were 82% (transvaginal) and 90% (transabdominal). Sexual function in the 64 sexually active patients was significantly improved, and overall disturbance by the fistula was reduced with both operative techniques. Neither surgical intervention was superior to the other regarding any domain of sexual function or visual analog scale. CONCLUSION Fistula repair improves sexual function and quality of life with no difference attributable to surgical route. Given this and that operating time, blood loss and length of stay are less with the transvaginal approach, the transvaginal approach is preferred in VVF repair if fistula and patient characteristics are suitable.

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Numerous co-factors, genetic, environmental and physical, play an important role in development and prognosis of cancer. Each year in the USA, more than 31,000 cases of oral and 13,000 cases of cervical cancer are diagnosed. Substantial epidemiological data supports a high correlation between development of these cancers and the presence of specific types of human papillomaviruses (HPV). Molecular biological studies show that not only are several of the viral genes necessary and sufficient to cause transformation but they also function synergistically with other co-factors. Evidence suggests that prevention of infection or inhibition of viral gene expression may alter the course of malignant transition. The main objective of this project was to test the hypothesis that some human carcinoma cells, containing HPV, behave in malignant manner because the viral genes function in the maintenance of some aspect of the transformed phenotype.^ The specific aims were (1) to select oral and cervical cancer cell lines which were HPV-negative or which harbored transcriptionally active HPV-18, (2) to construct and determine the effects of recombinant sense or antisense expressing vectors, (3) to test the effects of synthetic antisense oligodeoxynucleotides on the transformed behavior of these cells.^ To screen cells, we performed Southern and Northern analysis and polymerase chain reactions. When antisense-expressing vectors were used, cells harboring low numbers of HPV-18 where unable to survive transfection but they were readily transfected with all other constructs. Rare antisense transfectants obtained from HPV-positive cells showed significantly altered characteristics including malignant potential in nude mice. The HPV-negative cells showed no differences in transfection efficiencies or growth characteristics with any construct.^ In addition, treatment of the HPV-positive cells with antisense, but not random oligodeoxynucleotides, resulted in decreased cell proliferation and even cell death. These effects were dose-dependent, synergistic and HPV-specific.^ These results suggest that expression of viral genes play an important role in the maintenance of the transformed phenotype which implies that inhibition of expression, by antisense molecules, may be therapeutic in HPV-induced tumors. ^

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OBJECTIVE To investigate the association of renal impairment on functional outcome and complications in stroke patients treated with IV thrombolysis (IVT). METHODS In this observational study, we compared the estimated glomerular filtration rate (GFR) with poor 3-month outcome (modified Rankin Scale scores 3-6), death, and symptomatic intracranial hemorrhage (sICH) based on the criteria of the European Cooperative Acute Stroke Study II trial. Unadjusted and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Patients without IVT treatment served as a comparison group. RESULTS Among 4,780 IVT-treated patients, 1,217 (25.5%) had a low GFR (<60 mL/min/1.73 m(2)). A GFR decrease by 10 mL/min/1.73 m(2) increased the risk of poor outcome (OR [95% CI]): (ORunadjusted 1.20 [1.17-1.24]; ORadjusted 1.05 [1.01-1.09]), death (ORunadjusted 1.33 [1.28-1.38]; ORadjusted 1.18 [1.11-1.249]), and sICH (ORunadjusted 1.15 [1.01-1.22]; ORadjusted 1.11 [1.04-1.20]). Low GFR was independently associated with poor 3-month outcome (ORadjusted 1.32 [1.10-1.58]), death (ORadjusted 1.73 [1.39-2.14]), and sICH (ORadjusted 1.64 [1.21-2.23]) compared with normal GFR (60-120 mL/min/1.73 m(2)). Low GFR (ORadjusted 1.64 [1.21-2.23]) and stroke severity (ORadjusted 1.05 [1.03-1.07]) independently determined sICH. Compared with patients who did not receive IVT, treatment with IVT in patients with low GFR was associated with poor outcome (ORadjusted 1.79 [1.41-2.25]), and with favorable outcome in those with normal GFR (ORadjusted 0.77 [0.63-0.94]). CONCLUSION Renal function significantly modified outcome and complication rates in IVT-treated stroke patients. Lower GFR might be a better risk indicator for sICH than age. A decrease of GFR by 10 mL/min/1.73 m(2) seems to have a similar impact on the risk of death or sICH as a 1-point-higher NIH Stroke Scale score measuring stroke severity.

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Ethanolic fermentation is classically associated with flooding tolerance when plant cells switch from respiration to anaerobic fermentation. However, recent studies have suggested that fermentation also has important functions in the presence of oxygen, mainly in germinating pollen and during abiotic stress. Pyruvate decarboxylase (PDC), which catalyzes the first step in this pathway, is thought to be the main regulatory enzyme. Here, we characterize the PDC gene family in Arabidopsis. PDC is encoded by four closely related genes. By using real-time quantitative polymerase chain reaction, we determined the expression levels of each individual gene in different tissues, under normal growth conditions, and when the plants were subjected to anoxia or other environmental stress conditions. We show that PDC1 is the only gene induced under oxygen limitation among the PDC1 gene family and that a pdc1 null mutant is comprised in anoxia tolerance but not other environmental stresses. We also characterize the expression of the aldehyde dehydrogenase (ALDH) gene family. None of the three genes is induced by anoxia but ALDH2B7 reacts strongly to ABA application and dehydration, suggesting that ALDH may play a role in aerobic detoxification of acetaldehyde. We discuss the possible role of ethanolic fermentation as a robust back-up energy production pathway under adverse conditions when mitochondrial function is disturbed.

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INTRODUCTION: The objective of this study was to evaluate the effects of two different mean arterial blood pressure (MAP) targets on needs for resuscitation, organ dysfunction, mitochondrial respiration and inflammatory response in a long-term model of fecal peritonitis. METHODS: Twenty-four anesthetized and mechanically ventilated pigs were randomly assigned (n = 8/group) to a septic control group (septic-CG) without resuscitation until death or one of two groups with resuscitation performed after 12 hours of untreated sepsis for 48 hours, targeting MAP 50-60 mmHg (low-MAP) or 75-85 mmHg (high-MAP). RESULTS: MAP at the end of resuscitation was 56 ± 13 mmHg (mean ± SD) and 76 ± 17 mmHg respectively, for low-MAP and high-MAP groups. One animal each in high- and low-MAP groups, and all animals in septic-CG died (median survival time: 21.8 hours, inter-quartile range: 16.3-27.5 hours). Norepinephrine was administered to all animals of the high-MAP group (0.38 (0.21-0.56) mcg/kg/min), and to three animals of the low-MAP group (0.00 (0.00-0.25) mcg/kg/min; P = 0.009). The high-MAP group had a more positive fluid balance (3.3 ± 1.0 mL/kg/h vs. 2.3 ± 0.7 mL/kg/h; P = 0.001). Inflammatory markers, skeletal muscle ATP content and hemodynamics other than MAP did not differ between low- and high-MAP groups. The incidence of acute kidney injury (AKI) after 12 hours of untreated sepsis was, respectively for low- and high-MAP groups, 50% (4/8) and 38% (3/8), and in the end of the study 57% (4/7) and 0% (P = 0.026). In septic-CG, maximal isolated skeletal muscle mitochondrial Complex I, State 3 respiration increased from 1357 ± 149 pmol/s/mg to 1822 ± 385 pmol/s/mg, (P = 0.020). In high- and low-MAP groups, permeabilized skeletal muscle fibers Complex IV-state 3 respiration increased during resuscitation (P = 0.003). CONCLUSIONS: The MAP targets during resuscitation did not alter the inflammatory response, nor affected skeletal muscle ATP content and mitochondrial respiration. While targeting a lower MAP was associated with increased incidence of AKI, targeting a higher MAP resulted in increased net positive fluid balance and vasopressor load during resuscitation. The long-term effects of different MAP targets need to be evaluated in further studies.

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OBJECTIVE To assess long-term clinical outcomes of consecutive high-risk patients with severe aortic stenosis according to treatment allocation to transcatheter aortic valve implantation (TAVI), surgical aortic valve replacement (SAVR) or medical treatment (MT). METHODS Patients with severe aortic stenosis were consecutively enrolled into a prospective single centre registry. RESULTS Among 442 patients (median age 83 years, median STS-score 4.7) allocated to MT (n=78), SAVR (n=107), or TAVI (n=257) all-cause mortality amounted to 81%, 37% and 43% after a median duration of follow-up of 3.9 years (p<0.001). Rates of major adverse cerebro-cardiovascular events were lower in patients undergoing SAVR or TAVI as compared with MT (SAVR vs MT: HR 0.31, 95% CI 0.21 to 0.46) (TAVI vs MT: HR 0.34, 95% CI 0.25 to 0.46), with no significant difference between SAVR and TAVI (HR 0.88, 95% CI 0.62 to 1.25). Whereas SAVR (HR 0.39, 95% CI 0.24 to 0.61), TAVI (HR 0.37, 95% CI 0.26 to 0.52), and female gender (HR 0.72, 95% CI 0.53 to 0.99) were associated with improved survival, body mass index ≤20 kg/m(2) (HR 1.60, 95% CI 1.04 to 2.47), diabetes (HR 1.48, 95% CI 1.03 to 2.12), peripheral vascular disease (HR 2.01, 95% CI 1.44 to 2.81), atrial fibrillation (HR 1.74, 95% CI 1.28 to 2.37) and pulmonary hypertension (HR 1.43, 95% CI 1.03 to 2.00) were identified as independent predictors of mortality. CONCLUSIONS Among high-risk patients with severe aortic stenosis, long-term clinical outcome through 5 years was comparable between patients allocated to SAVR or TAVI. In contrast, patients with MT had a dismal prognosis.

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The objective of the present study was to assess the validity of barometric whole-body plethysmography (BWBP), to establish reference values, and to standardise a bronchoprovocative test to investigate airway responsiveness using BWBP in healthy dogs. BWBP measurements were obtained from six healthy beagle dogs using different protocols: (1) during three consecutive periods (3.5min each) in two morning and two evening sessions; (2) before and after administration of two protocols of sedation; (3) before and after nebulisation of saline and increasing concentrations of carbachol and histamine both in conscious dogs and in dogs under both protocols of sedation. Enhanced pause (PENH) was used as index of bronchoconstriction. Basal BWBP measurements were also obtained in 22 healthy dogs of different breeds, age and weight. No significant influence of either time spent in the chamber or daytime was found for most respiratory variables but a significant dog effect was detected for most variables. A significant body weight effect was found on tidal volume and peak flow values (P<0.05). Response to carbachol was not reproducible and always associated with side effects. Nebulisation of histamine induced a significant increase in respiratory rate, peak expiratory flow, peak expiratory flow/peak inspiratory flow ratio and PENH (P<0.05). The response was reproduced in each dog at different concentrations of histamine. Sedation with acepromazine+buprenorphine had little influence on basal measurements and did not change the results of histamine challenge. It was concluded that BWBP is a safe, non invasive and reliable technique of investigation of lung function in dogs which provides new opportunities to characterise respiratory status, to evaluate airway hyperresponsiveness and to assess therapeutic interventions.

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BACKGROUND Unilateral ischemic stroke disrupts the well balanced interactions within bilateral cortical networks. Restitution of interhemispheric balance is thought to contribute to post-stroke recovery. Longitudinal measurements of cerebral blood flow (CBF) changes might act as surrogate marker for this process. OBJECTIVE To quantify longitudinal CBF changes using arterial spin labeling MRI (ASL) and interhemispheric balance within the cortical sensorimotor network and to assess their relationship with motor hand function recovery. METHODS Longitudinal CBF data were acquired in 23 patients at 3 and 9 months after cortical sensorimotor stroke and in 20 healthy controls using pulsed ASL. Recovery of grip force and manual dexterity was assessed with tasks requiring power and precision grips. Voxel-based analysis was performed to identify areas of significant CBF change. Region-of-interest analyses were used to quantify the interhemispheric balance across nodes of the cortical sensorimotor network. RESULTS Dexterity was more affected, and recovered at a slower pace than grip force. In patients with successful recovery of dexterous hand function, CBF decreased over time in the contralesional supplementary motor area, paralimbic anterior cingulate cortex and superior precuneus, and interhemispheric balance returned to healthy control levels. In contrast, patients with poor recovery presented with sustained hypoperfusion in the sensorimotor cortices encompassing the ischemic tissue, and CBF remained lateralized to the contralesional hemisphere. CONCLUSIONS Sustained perfusion imbalance within the cortical sensorimotor network, as measured with task-unrelated ASL, is associated with poor recovery of dexterous hand function after stroke. CBF at rest might be used to monitor recovery and gain prognostic information.

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OBJECTIVES Objective evaluation of the impact of minimized extracorporeal circulation (MECC) on perioperative cognitive brain function in coronary artery bypass grafting (CABG) by electroencephalogram P300 wave event-related potentials and number connection test (NCT) as metrics of cognitive function. METHODS Cognitive brain function was assessed in 31 patients in 2013 with a mean age of 65 years [standard deviation (SD) 10] undergoing CABG by the use of MECC with P300 auditory evoked potentials (peak latencies in milliseconds) directly prior to intervention, 7 days after and 3 months later. Number connection test, serving as method of control, was performed simultaneously in all patients. RESULTS Seven days following CABG, cognitive P300 evoked potentials were comparable with preoperative baseline values [vertex (Cz) 376 (SD 11) ms vs 378 (18) ms, P = 0.39; frontal (Fz) 377 (11) vs 379 (21) ms, P = 0.53]. Cognitive brain function at 3 months was compared with baseline values [(Cz) 376 (11) ms vs 371 (14 ms) P = 0.09; (Fz) 377 (11) ms vs 371 (15) ms, P = 0.04]. Between the first postoperative measurement and 3 months later, significant improvement was observed [(Cz) 378 (18) ms vs 371 (14) ms, P = 0.03; (Fz) 379 (21) vs 371 (15) ms, P = 0.02]. Similar clearly corresponding patterns could be obtained via the number connection test. Results could be confirmed in repeated measures analysis of variance for Cz (P = 0.05) and (Fz) results (P = 0.04). CONCLUSIONS MECC does not adversely affect cognitive brain function after CABG. Additionally, these patients experience a substantial significant cognitive improvement after 3 months, evidentiary proving that the concept of MECC ensures safety and outcome in terms of brain function.

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The single-layered gut epithelium represents the primary line of defense against environmental stressors; thereby monolayer integrity and tightness are essentially required to maintain gut health and function. To date only a few plant-derived phytochemicals have been described as affecting intestinal barrier function. We investigated the impact of 28 secondary plant compounds on the barrier function of intestinal epithelial CaCo-2/TC-7 cells via transepithelial electrical resistance (TEER) measurements. Apart from genistein, the compounds that had the biggest effect in the TEER measurements were biochanin A and prunetin. These isoflavones improved barrier tightness by 36 and 60%, respectively, compared to the untreated control. Furthermore, both isoflavones significantly attenuated TNFα-dependent barrier disruption, thereby maintaining a high barrier resistance comparable to nonstressed cells. In docking analyses exploring the putative interaction with the tyrosine kinase EGFR, these novel modulators of barrier tightness showed very similar values compared to the known tyrosine kinase inhibitor genistein. Both biochanin A and prunetin were also identified as potent reducers of NF-κB and ERK activation, zonula occludens 1 tyrosine phosphorylation, and metalloproteinase-mediated shedding activity, which may account for the barrier-improving ability of these isoflavones.

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BACKGROUND Cystic fibrosis (CF) lung disease starts in the first months of life often before the onset of clinical symptoms. Multiple breath washout (MBW) detects abnormal lung function in infants and young children in the laboratory setting. OBJECTIVE The aim of this study was to determine the feasibility of MBW in 0- to 4-year-old children with CF and non-CF controls in the clinical setting. METHODS Fourteen children with CF (mean age 1.3 ± 1.0 years) and 26 age-matched non-CF controls were sedated with chloral hydrate and MBW was performed with sulfur hexafluoride. RESULTS MBW measurements were successful in 27 of 40 children (67.5%). The mean lung clearance index (LCI) was significantly higher in CF patients compared to non-CF controls (p = 0.006). Further, the frequency of elevated LCI (z-score >1.96) was significantly increased in CF patients compared to controls (p = 0.0003). CONCLUSIONS We conclude that MBW is feasible and sensitive to detect abnormal lung function in infants and young children with CF in the clinical setting.

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When kept in barren and restrictive cages, animals frequently develop stereotypic behaviour patterns that are characterized by high repetition rates, conspicuous invariance and an apparent lack of function. Although millions of animals are affected, the underlying causes and mechanisms are still unclear. Growing evidence suggests that cage-induced stereotypies may reflect pathological dysfunction within basal ganglia circuitry expressed by perseverative behaviour. In order to assess whether variation in stereotypy performance and variation in perseverative behaviour may have a common cause in ICR CD-1 mice, we assessed the effects of environmental enrichment on both phenomena. We raised 48 female ICR CD-1 mice in standard or enriched cages from three weeks to either 6 or 11 months of age and measured stereotypy level in the home cage and perseveration on an extinction task. We further examined whether enriched rearing conditions (early enrichment) protect mice from the developing stereotypies later in life and whether stereotypies developed in barren cages would persist in an enriched environment (late enrichment) by transferring standard mice to enriched cages and vice versa for 14 weeks after completion of the extinction task. We found no evidence for a causal relation between stereotypy and perseveration in mice. However, transfer to enriched cages reduced stereotypy levels significantly both at 6 and 11 months of age indicating that stereotypies had not become established yet. Finally, we found that removing enrichments at both ages did not induce higher stereotypy levels, thereby confirming earlier reports of a neuroprotective effect of early enrichment.