629 research outputs found
Bayesian Inference For Exponential Distribution Based On Upper Record Range
This paper deals with Bayesian estimations of scale parameter of the
exponential distribution based on upper record range (Rn). This has been done
in two steps; point and interval. In the first step the quadratic, squared
error and absolute error, loss functions have been considered to obtain
Bayesian-point estimations. Also in the next step the shortest Bayes interval
(Hight Posterior Density interval) and Bayes interval with equal tails based on
upper record range have been found. Therefore, the Homotopy Perturbation
Method(HPM) has been applied to obtain the limits of Hight Posterior Density
intervals. Moreover, efforts have been made to meet the admissibility
conditions for linear estimators based on upper record range of the form mRn+d
by obtained Bayesian point estimations. So regarding the consideration of loss
functions, the prior distribution between the conjunction family has been
chosen to be able to produce the linear estimations from upper record range
statistics. Finally, some numerical examples and simulations have been
presented
Variation in ecosystem service values in response to land use changes in Zhifanggou watershed of Loess plateau: a comparative study
Background: Anthropological activities could lead to various land use changes. This subsequently exerts impacts on the Ecological status as the land is the carrier of Ecosystems and their services. Ecosystem Services Values (ESVs) are monetary assessment of ecosystems services. The choice of ecosystem services valuation methods highly depends on the type and conditions of the ecological environment.
Results: In this paper, Zhifangou watershed, a watershed with fragile environments in Loess Plateau, is analyzed in terms of the historical changes of land uses and their impact on Ecosystem Services Values (ESVs). The analysis presents that the watershed had seen a large cover of forest (689.8 hectare) and grassland (97.08 hectare) until 1938, which were substituted with a cropland of 663.56 hectare in the following years, and then a gradual recovery of natural land from 1978. During these years, the human activities have ranged from little disruption, to excessive cultivation, and finally to an integrated management of the watershed. The ESVs were highest at 43.75 × 104 in 1958, and then rebounded to $113.44 × 104 in 1999.
Conclusions: The analysis reveals that the values of soil formation and retention, biodiversity protection, and climate regulation have been associated with the largest share of the total ESVs. Among them, soil formation and retention was recognized as the most impacted service by land use changes
Urban water reuse: A triple bottom line assessment framework and review
Water reuse networks have been emerging globally for the last 50 years. This article reviews the economic, social and environmental issues related to implementing water reuse networks in cities. This is reflecting the fact that globally many cities are categorised as water scarce areas, where there is growing imbalance between water demand and availability. In this sense, there is a need for sustainable water supply solutions in the imminent future to provide and maintain service reliability, particularly in the face of climate change. To demonstrate the sustainability implications of water reuse practices, we review a case study in London, UK
Study of the effect of bacterial lipopolysaccharide on the structure and dynamics on mouse tubulin polymerization
Background and aims: In recent decades, there has been much research on the microtubule dynamics as well as on factors affecting it. According to different studies, lipopolysaccharide (LPS) is thought to play an indirect role in neurodegenerative diseases through enzymatic pathways which hyperphosphorylate Tau protein and dissociate it from microtubules. In the present study, it was aimed to assess the direct effect of LPS on the structure and dynamics of tubulin polymerization in vitro.
Methods: In this study, mouse tubulins were purified through two cycles of temperature-dependent polymerization-depolymerization. Cellulose-phosphate chromatography was used to further purify tubulins. SDS-PAGE was used to analyze the purity of the tubulins. Circular dichroism (CD), intrinsic fluorescence and turbidity assays were used to assess the changes in secondary and tertiary structures, and the dynamics of tubulin polymerization in the presence of different concentrations of LPS (5pM, 5nM, 50nM, 0.5µM and 5µM), respectively.
Results: SDS-PAGE analysis confirmed the purity of tubulins. The intrinsic fluorescence analysis and CD assay revealed the changes in the secondary and tertiary structures of tubulins in the presence of LPS. The results of turbidity assay indicated that LPS could reduce the polymerization of tubulins.
Conclusion: Our results indicate that LPS is able to change the secondary and tertiary structures of tubulin and decreases tubulin polymerization. According to our results, lipopolysaccharide in addition to an indirect effect on the microtubules stability, as well as by decreases in tubulin polymerization could result in neurodegenerative diseases specially Alzheimer's diseases
The effect of posture in premature infants on the arterial oxygen saturation, fraction of inspired oxygen and abdominal distension
Background: Putting infants in a posture that reduces oxygen requirement and the complications of the continuous positive airway pressure method is very important. This study aimed at examining the effect of the posture on the arterial oxygen saturation, fraction of inspired oxygen (FIO2) and abdominal distension in premature infants with the respiratory distress syndrome under nasal continuous positive airway pressure. Materials and Methods: In this clinical trial study, 41 premature infants were selected by the simple random sampling and one-group before-after design. The amounts of arterial oxygen saturation, FIO2 and abdominal distension in supine and prone positions were recorded in a data-collection form. Results: There was a significant difference between the mean FIO2 and between the mean abdominal circumference in the prone and supine positions (P=0.022, P<0.001, respectively). There was no significant difference in the mean of arterial oxygen saturation between the two positions (P=0.749). Conclusion: According to the results of the present study, the neonates’ abdominal distension and FIO2 decreased in the prone position. Thus, this supportive, free of charge and effective method can be recommended for these neonates
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