1,518 research outputs found
Energy and environmental systems planning under uncertainty-An inexact fuzzy-stochastic programming approach
In this study, an inexact fuzzy-stochastic energy model (IFS-EM) is developed for planning energy and environmental systems (EES) management under multiple uncertainties. In the IFS-EM, methods of interval parameter fuzzy linear programming (IFLP) and multistage stochastic programming with recourse (MSP) are introduced into a mixed-integer linear programming (MILP) framework, such that the developed model can tackle uncertainties described in terms of interval values, fuzzy sets and probability distributions. Moreover, it can reflect dynamic decisions for facility-capacity expansion and energy supply over a multistage context. The developed model is applied to a case of planning regional-scale energy and environmental systems to demonstrate its applicability, where three cases are considered based on different energy and environmental management policies. The results indicate that reasonable solutions have been generated. They are helpful for supporting: (a) adjustment or justification of allocation patterns of regional energy resources and services, (b) formulation of local policies regarding energy consumption, economic development and environmental protection, and (c) in-depth analysis of tradeoffs among system cost, satisfaction degree and environmental requirement under multiple uncertainties. (C) 2010 Elsevier Ltd. All rights reserved
Targeted Albumin Therapy Does Not Improve Short-Term Outcome in Hyponatremic Patients Hospitalized With Complications of Cirrhosis: Data From the ATTIRE Trial
INTRODUCTION:
Patients with decompensated cirrhosis and hyponatremia have a poor prognosis. We investigated Albumin to Prevent Infection in Chronic Liver Failure trial data to determine whether targeted albumin infusions improved outcome in patients with hyponatremia at baseline.
METHODS:
We examined the interaction between targeted albumin and standard care for the composite primary end point, stratifying by baseline sodium ≥ and <130 mmol/L.
RESULTS:
Randomization to albumin was associated with a significant increase in sodium; however, there was no interaction between sodium category and treatment for the trial primary end point.
DISCUSSION:
Targeted intravenous albumin infusions increased serum sodium level in hospitalized hyponatremic patients with cirrhosis, but this did not improve outcome
Use of non-selective B-blockers is safe in hospitalised decompensated cirrhosis patients and exerts a potential anti-inflammatory effect: Data from the ATTIRE trial
Background: Nonselective B-blockers (NSBBs) are believed to have pleiotropic effects beyond reducing portal pressure. However, studies also report potential harm in patients hospitalized with cirrhosis and ascites. We therefore investigated whether NSBB use at ATTIRE trial entry (Albumin to prevent infection in chronic liver failure, 2016-19) was associated with increased renal or cardiovascular dysfunction, compared the incidence of infection and plasma markers of systemic inflammation, and examined mortality at 28-days, 3 and 6-months. Methods: In ATTIRE patients grouped by NSBB use at trial entry, we studied infection at baseline, hospital acquired infection and organ dysfunction during trial treatment period and mortality, with propensity score matching to account for differences in disease severity. Findings: There were no differences in renal or cardiovascular dysfunction between patients treated with NSBBs or not, during days 3–15 of hospitalization, despite elevated serum creatinine in NSBB patients at hospitalisation. Use of NSBBs was associated with a significant reduction in infection at hospitalization (p = 0.006), lower white cell counts throughout hospital stay (p < 0.001) and reduced plasma procalcitonin (p = 0.009) and interlukin-8 levels (p = 0.04) at baseline, but markers of bacterial translocation and systemic inflammation were the same in treatment groups. There was no reduction in hospital acquired infections in patients taking NSBBs and no beneficial impact on mortality at 28-days, 3 and 6-months. Interpretations: Our real-world data from a completed randomised trial show that use of NSBBs in decompensated cirrhosis patients is safe during hospitalisation. We also show a potential anti-inflammatory role for NSBBs which may be mediated by a downregulation of IL-8 induced leucocytosis, that was associated with reduced infection at baseline but not a survival benefit. Funding: Wellcome Trust and Department of Health and Social Care
Investigating potential confounding by indication when considering the association between proton pump inhibitor use, infection, hepatic encephalopathy and mortality in hospitalised decompensated cirrhosis: a post-hoc analysis of the ATTIRE trial
BACKGROUND:
Proton pump inhibitors (PPIs) are commonly prescribed to prevent and treat upper gastrointestinal ulceration and bleeding. Studies have identified increased incidence of spontaneous bacterial peritonitis and hepatic encephalopathy (HE) in cirrhosis patients taking PPIs. However, results are conflicting, and as PPIs are prescribed for variceal bleeding, a major risk factor for infection and HE, it is challenging to discern whether these associations are causal.
METHODS:
In this post-hoc analysis of the ATTIRE trial, we pooled all patient data to investigate the effects of PPI use on clinical outcomes. ATTIRE was a multicentre, open-label, randomised trial of targeted 20% human albumin solution (HAS) daily infusions versus standard care involving 777 adults with decompensated cirrhosis hospitalised with acute complications and albumin <30 g/L. Study recruitment was between Jan 25, 2016, and June 28, 2019, at 35 hospitals across England, Scotland, and Wales. Key exclusion criteria were advanced hepatocellular carcinoma with life expectancy <8 weeks and patients receiving palliative care. In ATTIRE, patients were grouped by PPI use at trial entry. We studied infection and HE at baseline and incidence of hospital acquired infection, new onset HE, renal dysfunction and mortality. We attempted with propensity score matching to account for differences in disease severity.
FINDINGS:
Overall PPI use at baseline was not associated with increased incidence of infection, renal dysfunction or mortality, but was associated with significantly increased incidence of grade III/IV HE during hospital stay (P = 0.011). This was only significant for those taking intravenous PPIs and these patients had >10 times the incidence of variceal bleeding and near double the 28-day mortality compared to non-PPI patients. However, propensity score matching was not possible as there was such a strong selection of patients for PPI use, that we could not find sufficient non-PPI patients to match to. We found no impact of PPI use on plasma markers of bacterial translocation, infection or systemic inflammation.
INTERPRETATIONS:
Our real-world data from a completed randomised trial show that PPIs are widely prescribed in the UK and judicious use appears safe in patients hospitalised with decompensated cirrhosis. However, patients prescribed PPIs had fundamentally different phenotypes to those not prescribed PPIs, a form of confounding by indication, which should be strongly considered when interpreting studies and making recommendations about their use.
FUNDING:
Wellcome Trust and Department of Health and Social Care
Study on Chinese Tourism Web Sites' Distribution and Online Marketing Effects.
As a platform and carrier of tourism information, tourism websites (TWs) and online tourism marketing have deeply affected the tourism industry. The authors adopt a geographical perspective to analyze the distribution of Chinese tourism websites (CTWs), and statistical analysis with SPSS16.0 was conducted to explore the online marketing effects of CTWs, and some meaningful results has been produced: 1) The number of CTWs generally decreases from eastern China to central and western China, and are especially dominant in tourism developed provinces. 2) The number of tourists has strong statistical correlation with the number of CTWs. 3) The strongest correlation for inbound tourists is with hotel websites, and the highest correlation coefficient is 0.807 between the number of domestic tourist and resort websites. Both inbound and domestic tourists have a low correlation coefficient with travel agency websites (TA). 4) There exist some statistical models between tourist numbers and different kinds of CTWs. The results clearly unveil the marketing effects and correlation of CTWs and is helpful for further online marketing strategies
Genetic diversity of plankton community as depicted by PCR-DGGE fingerprinting and its relation to morphological composition and environmental factors in lake donghu
To collect information about the genetic diversity of the plankton community and to study how plankton respond to environmental conditions, plankton samples were collected from five stations representing different trophic levels in a shallow, eutrophic lake (Lake Donghu), and investigated by PCR-DGGE fingerprinting. A total of 100 bands (61 of 16S rDNA bands and 39 of 18S rDNA bands) were detected. The DGGE bands unique to any single station accounted for 38% of the total bands, whereas common bands detected at all five stations accounted for only 11%. Using UPGMA clustering and MDS ordination of DGGE fingerprints, stations I and II were found to initially group together into one cluster, which was later joined by station V. Stations III and IV were isolated into two separate groups of one station each. Some differences in grouping relationships were found when analysis was completed on the basis of chemical characteristics and morphological composition, with zooplankton composition showing the greatest variability. However, the most similar stations (I and II) were always initially grouped into one cluster. Moreover, stations that exhibited the same or similar trophic level (stations III and IV), but different concentrations of heavy metals, were further differentiated by the DGGE method. Results of the present study indicated that PCR-DGGE fingerprinting was more sensitive than the traditional methods, as other studies suggested. Additionally, PCR-DGGE appears to be more appropriate for diversity characterization of the plankton community, as it is more canonical, systematic, and effective. Most importantly, fingerprinting results are more convenient for the comparative analyses between different studies. Therefore, the use of the described fingerprinting analysis may provide an operable and sensitive biomonitoring approach to identify critical, and potentially negative, stress within an aquatic ecosystem.To collect information about the genetic diversity of the plankton community and to study how plankton respond to environmental conditions, plankton samples were collected from five stations representing different trophic levels in a shallow, eutrophic lake (Lake Donghu), and investigated by PCR-DGGE fingerprinting. A total of 100 bands (61 of 16S rDNA bands and 39 of 18S rDNA bands) were detected. The DGGE bands unique to any single station accounted for 38% of the total bands, whereas common bands detected at all five stations accounted for only 11%. Using UPGMA clustering and MDS ordination of DGGE fingerprints, stations I and II were found to initially group together into one cluster, which was later joined by station V. Stations III and IV were isolated into two separate groups of one station each. Some differences in grouping relationships were found when analysis was completed on the basis of chemical characteristics and morphological composition, with zooplankton composition showing the greatest variability. However, the most similar stations (I and II) were always initially grouped into one cluster. Moreover, stations that exhibited the same or similar trophic level (stations III and IV), but different concentrations of heavy metals, were further differentiated by the DGGE method. Results of the present study indicated that PCR-DGGE fingerprinting was more sensitive than the traditional methods, as other studies suggested. Additionally, PCR-DGGE appears to be more appropriate for diversity characterization of the plankton community, as it is more canonical, systematic, and effective. Most importantly, fingerprinting results are more convenient for the comparative analyses between different studies. Therefore, the use of the described fingerprinting analysis may provide an operable and sensitive biomonitoring approach to identify critical, and potentially negative, stress within an aquatic ecosystem
Cosmopolitan Risk Community and China's Climate Governance
Ulrich Beck asserts that global risks, such as climate change, generate a form of ‘compulsory cosmopolitanism’, which ‘glues’ various actors into collective action. Through an analysis of emerging ‘cosmopolitan risk communities’ in Chinese climate governance, this paper points out a ‘blind spot’ in the theorisation of cosmopolitan belonging and an associated inadequacy in explaining shifting power-relations. The paper addresses this problem by engaging with the intersectionality of the cosmopolitan space. It is argued that cosmopolitan belonging is a form of performative identity. Its key characteristic lies in a ‘liberating prerogative’, which enables individuals to participate in the solution of common problems creatively. It is this liberating prerogative that coerces the state out of political monopoly and marks the cosmopolitan moment
Photosynthesis of Populus euphratica in relation to groundwater depths and high temperature in arid environment, northwest China
The photosynthetic characterization of Populus euphratica and their response to increasing groundwater depth and temperature were analyzed based on net photosynthetic rate (P (N)), stomatal conductance (g (s)), intercellular CO2 concentration (C (i)), transpiration rate (E), water use efficiency (WUE) and stomatal limitation (L-s) measured by a portable gas-exchange system (LI-6400) in the lower reaches of the Tarim River. Light-response curves were constructed to obtain light-compensation and light-saturation points (LCP and LSP), maximum photosynthetic rates (P (max)), quantum yields (AQY), and dark respiration rates (R (D)). The growth condition of P. euphratica, soil moisture, and groundwater depth in the plots were analyzed by field investigation. The results showed that the growth condition and photosynthetic characterization of P. euphratica were closely related to groundwater depth. The rational groundwater depth for the normal growth and photosynthesis was 3-5 m, the stress groundwater depth for mild drought was more than 5 m, for moderate drought was more than 6 m, for severe drought was more than 7 m. However, P. euphratica could keep normal growth through a strong drought resistance depended on the stomatal limitation and osmotic adjustment when it faced mild or moderate drought stress, respectively, at a normal temperature (25A degrees C). High temperature (40A degrees C) significantly reduced P (N) and drought stress exacerbated the damage of high temperature to the photosynthesis. Moreover, P. euphratica would prioritize the resistance of high temperature when it encountered the interaction between heat shock and water deficit through the stomata open unequally to improve the transpiration of leaves to dissipate overheating at the cost of low WUE, and then resist water stress through the osmotic adjustment or the stomatal limitation
Subjective evaluation of the environmental quality in China's industrial corridors.
Based on 270 questionnaire surveys in 8 cities of 5 industrial corridors in China, this study
aims to examine the effects of industry construction on the evaluation of environmental pollution, natural
environment, built environment, personal perception and development and policy. The results show that
the evaluations on environmental pollution and landscape design are both below the medium level, but
the evaluations of the living comfort and safety are both above the medium level. Further analysis,
females usually give lower evaluation scores than males, and age and health situations are negatively
related to the evaluation results; People indicate a great desire to reduce the environmental pollution and
protect the natural environment. Moreover, the landscape was analysed using colour extraction
techniques based on video recording, there are significant correlations between industrial pixel ratio and
evaluation results of air quality, vegetation pixel ratio and evaluation results of river water quality, and
public facilities pixel ratio and evaluation results of comfort levels
Groundwater fluctuations induced by ecological water conveyance in the lower Tarim River, Xinjiang, China
Data from 40 monitoring wells across 9 sections of the lower Tarim River from 2000 to 2006 were analyzed to investigate the relationship between the transmission loss per unit river length and the change in groundwater depth. The relationship between the rise of the groundwater table (y) and the distance from the main river reach (x) was then assessed through regression analysis. We concluded that the maximum affected area was 1933 m away from the main river reach in the Alagan section, and the minimum affected area was 576 m away in the Kaogan section. In addition, after 8 water deliveries, the volume for recharging the groundwater was 78 248.7 x 10(4) m(3). Using the Yingsu section as an example, we found that the volume for recharging the groundwater decreased with additional periods of delivery except after the second and sixth water delivery The results revealed that the beneficial effect of an ecological water conveyance project on the ecosystem in the lower Tarim River is a long-term process. These findings may be useful for guiding studies on instream flow requirements and provide a scientific basis for implementing similar ecological projects in other areas. (C) 2009 Elsevier Ltd. All rights reserved
- …