oalib

OALib Journal期刊

ISSN: 2333-9721

费用:99美元

投稿

时间不限

2019 ( 25 )

2018 ( 94 )

2017 ( 126 )

2016 ( 143 )

自定义范围…

匹配条件: “ Richard James” ,找到相关结果约38832条。
列表显示的所有文章,均可免费获取
第1页/共38832条
每页显示
Inexpensive Geophysical Instruments Supporting Groundwater Exploration in Developing Nations  [PDF]
James A. Clark, Richard Page
Journal of Water Resource and Protection (JWARP) , 2011, DOI: 10.4236/jwarp.2011.310087
Abstract: Geophysical methods are often used to aid in exploration for safe and abundant groundwater. In particular resistivity and seismic refraction methods are helpful in determining depth to bedrock and zones of saturation in the subsurface. However the expense of these instruments ($5000 to $20,000) has resulted in their limited use in developing countries. This paper describes how to construct these devices for less than $250 each. The instruments are small, light and robust and are as useful for groundwater exploration as the commercial models for shallow aquifers (less than 35 m deep) where wells can be hand dug, augured or drilled with small portable drill rigs. Data interpretation can be accomplished quickly in the field with free software implemented on a laptop computer. A suite of geophysical instruments and software can therefore be assembled for less than $850. This paper gives the design for these instruments and essential information needed to use them. It is hoped that these inexpensive geophysical instruments can be widely distributed among drillers and aid workers in developing countries, improving the success rate of water wells.
A Case of Cytomegalovirus-Induced Arthritis after Lymphocyte-Depleting Therapy for Kidney Allograft Rejection  [PDF]
Richard Fuquay, James Eric Cooper
Open Journal of Nephrology (OJNeph) , 2012, DOI: 10.4236/ojneph.2012.21001
Abstract: Cytomegalovirus viremia and tissue-invasive disease are common after kidney transplantation. Chemoprophylaxis has made substantial improvement in this clinical problem. Here we report a 29-year-old woman who had kidney allograft rejection and received lymphocyte-depleting therapy. She presented with a new oligo-arthritis that led to 2 successive arthrocenteses. The etiology of the inflammation could not be determined initially. On the second arthrocentesis, a synovial fluid cytomegalovirus polymerase chain reaction test was positive. The patient responded to treatment with valganciclovir, had negative follow-up serum cytomegalovirus polymerase chain reaction tests, and experienced resolution of her joint inflammation. We review briefly the data for cytomegalovirus chemoprophylaxis, preemptive screening, and treatment recommendations.
Climate Change, Adaptive Strategies and Rural Livelihoods in Semiarid Tanzania  [PDF]
Richard Y. M. Kangalawe, James G. Lyimo
Natural Resources (NR) , 2013, DOI: 10.4236/nr.2013.43034
Abstract:

Climate change is a global challenge to both sustainable livelihoods and economic development. In Tanzania as in most African countries, farming depends almost entirely on rainfall, a situation that makes agriculture and thus rural livelihoods especially in semiarid environments particularly vulnerable to climate change. This study analyses the impacts of climate change and variability on rural livelihoods with particular focus on agricultural production, food security and adaptive capacities in semiarid areas of Tanzania. The methods used in this study included focus group discussions, key informant interviews, household surveys and field observations. Results from the study indicate that communities understood climate change in terms of variability in rainfall patterns and amount, temperature patterns, wind, water availability, increased incidences of drought and decreased agricultural productivity. Communities in the study area acknowledged that while rainfall amounts have decreased over the last thirty years, temperatures have increased; an experience is also supported by meteorological data. Such changes were claimed to have reduced agricultural productivity particularly due to prolonged drought, inadequate and uneven distribution of rainfall as well as unpredictable onset and ending of rains. Stressors such as
crop diseases and pests, low soil fertility and inadequate extension services were also reported to contribute to the decline in agricultural productivity and re-occurrence of food insecurity. In response, communities have developed multiple adaptation strategies
, including growing of drought tolerant and early maturing crop varieties, increasing wetlands cultivation, water harvesting for small-scale irrigation and livestock keeping. However, households with limited livelihood assets are more vulnerable to the impacts of climate change and food insecurity. The study argues that diversification of adaptive strategies, such as water harvesting for small-scale irrigation, integration of livestock and crop production are crucial to ensuring sustainable livelihood in a

Recently published papers: A review of novel strategies in the prevention of hospital-acquired infections, the ability of intensivists to perform echocardiography, and the benefit of polymyxin B haemoperfusion in abdominal sepsis
James Hayward, Richard Venn
Critical Care , 2009, DOI: 10.1186/cc7992
Abstract: Prevention of hospital-acquired infections and ventilator-associated pneumonias is a key concern in the reduction of mortality in both the critical care and general ward patient populations. A number of recent articles have evaluated differing approaches relating to this topic [1-4].Climo and colleagues studied the effect of daily 4% chlorhexidine baths on colonisation and subsequent bloodstream infection with multidrug-resistant organisms, in a multicentred before–after study [1]. The acquisition of methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus, as detected by active surveillance cultures, was shown to be significantly reduced (methicillin-resistant S. aureus incidence density 5.04 vs. 3.44 cases per 1,000 eligible patient-days, P = 0.046; vancomycin-resistant enterococcus incidence density 4.35 vs. 2.19 cases per 1,000 eligible patient-days, P = 0.008). Furthermore, the authors showed that the incidence of vancomycin-resistant enterococcus bacteremias decreased significantly following the intervention (2.13 vs. 0.59 cases per 1,000 patient-days). Owing to the low rate of methicillin-resistant S. aureus bacteremia prior to the change in practice, Climo and colleagues were unable to show a significant reduction in methicillin-resistant S. aureus bloodstream infections, although they suggest that with sufficiently powered studies this may also be shown to be the case.Panchabhai and colleagues compared oropharyngeal cleansing using 0.2% chlorhexidine with the study intensive care unit (ICU) policy of twice-daily 0.01% potassium permanganate in a randomised controlled trial [2]. Within their study population of 471 patients in total there was no significant difference between groups. The authors do observe, however, that the incidence of nosocomial pneumonias on their ICU in the 3 months prior to the study and in the 3 months after the study was significantly higher than during the 6-month study period (21.7% vs. 7.4%; P < 0.001). Th
The Moment Generating function for ray lengths in the Half Gilbert Model with Rectangular Cells
James Burridge,Richard Cowan
Mathematics , 2013,
Abstract: In the full rectangular version of Gilbert's tessellation lines extend either horizontally (with east- and west--growing rays) or vertically (north- and south--growing rays) from seed points which form a Poisson point process, each ray stopping when another ray is met. In the half rectangular version, east and south growing rays do not interact with west and north rays. Using techniques developed in our previous paper, we derive an exact expression for the moment generating function for the ray length distribution in the half rectangular model.
Domino tilings with barriers
James Propp,Richard Stanley
Mathematics , 1998,
Abstract: In this paper, we continue the study of domino-tilings of Aztec diamonds. In particular, we look at certain ways of placing ``barriers'' in the Aztec diamond, with the constraint that no domino may cross a barrier. Remarkably, the number of constrained tilings is independent of the placement of the barriers. We do not know of a combinatorial explanation of this fact; our proof uses the Jacobi-Trudi identity.
Assessment of Mangrove Covers Change and Biomass in Mida creek, Kenya  [PDF]
Fikir Alemayehu, Onwonga Richard, Kinyanjui Mwangi James, Oliverv Wasonga
Open Journal of Forestry (OJF) , 2014, DOI: 10.4236/ojf.2014.44045
Abstract:
This study uses old aerial photographs, current high resolution satellite images and ground truthing to analyze the patterns and dynamics of Mida Creek mangrove forest changes over 41 years from 1969-2010. A non-distractive method was used to collect data on 25 sample plots and 934 trees were measured to estimate the above ground biomass and carbon stock of the forest. General published allometric equations with variables of Diameter at Breast Height (DBH) and wood density (ρ) which were species specific were used to estimate above ground biomass. A decline in mangrove cover (16%) took place between 1969 and 1989 and between 1989 and 2010 an increment was observed in mangrove cover (1452.5 ha in 1989 to 1655.7 ha in 2010). Signs of degradation within the mangrove forest were observed in 2010 in which the degraded land covered 8.8 ha. The total above ground biomass and carbon estimated on the 25 plots was 296.14 ton·ha-1 and 148.07 ton·ha-1 respectively. Mida Creek mangrove forest is largely dominated by the presence of Rhizophora mucronata and Ceriop tagal and the regeneration of these two species is very high. If the present dominance of the two species continues it will affect the species composition of the current mangrove forest. This study recommends a better management plan for the mangrove forest through increasing involvement of the surrounding communities. Furthermore, there should be a way to control selective and illegal cutting of mangroves and promote other species of trees for domestic and commercial use to reduce the high dependency on the use of mangroves for construction purposes.
Strength of Social Tie Predicts Cooperative Investment in a Human Social Network
Freya Harrison,James Sciberras,Richard James
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0018338
Abstract: Social networks – diagrams which reflect the social structure of animal groups – are increasingly viewed as useful tools in behavioural ecology and evolutionary biology. Network structure may be especially relevant to the study of cooperation, because the action of mechanisms which affect the cost:benefit ratio of cooperating (e.g. reciprocity, punishment, image scoring) is likely to be mediated by the relative position of actor and recipient in the network. Social proximity could thus affect cooperation in a similar manner to biological relatedness. To test this hypothesis, we recruited members of a real-world social group and used a questionnaire to reveal their network. Participants were asked to endure physical discomfort in order to earn money for themselves and other group members, allowing us to explore relationships between willingness to suffer a cost on another's behalf and the relative social position of donor and recipient. Cost endured was positively correlated with the strength of the social tie between donor and recipient. Further, donors suffered greater costs when a relationship was reciprocated. Interestingly, participants regularly suffered greater discomfort for very close peers than for themselves. Our results provide new insight into the effect of social structure on the direct benefits of cooperation.
Structure and Function of Window Glass and Pyrex
James C. Phillips,Richard Kerner
Physics , 2006,
Abstract: Window glass is a ternary mixture, while pyrex (after window glass, the most common form of commercial glass) is a quaternary. Building on our previous success in deriving the composition of window glass (sodium calcium silicate) without adjustable parameters, and borrowing from known reconstructed crystalline surfaces, we model pyrex as silica clusters with a specific ternary interface. Our global model explains the thermal expansivity contours of ternary sodium borosilicates, and it is consistent with the optimized resistance of pyrex to mechanical and thermal shocks. It suggests new directions for studying the nanoscopic structure of these remarkable materials.
Computation of Variances in Causal Networks
Richard E. Neapolitan,James Kenevan
Computer Science , 2013,
Abstract: The causal (belief) network is a well-known graphical structure for representing independencies in a joint probability distribution. The exact methods and the approximation methods, which perform probabilistic inference in causal networks, often treat the conditional probabilities which are stored in the network as certain values. However, if one takes either a subjectivistic or a limiting frequency approach to probability, one can never be certain of probability values. An algorithm for probabilistic inference should not only be capable of reporting the inferred probabilities; it should also be capable of reporting the uncertainty in these probabilities relative to the uncertainty in the probabilities which are stored in the network. In section 2 of this paper a method is given for determining the prior variances of the probabilities of all the nodes. Section 3 contains an approximation method for determining the variances in inferred probabilities.
第1页/共38832条
每页显示


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.