bluuebunny/crossref_metadata_2025_split huggingface dataset:
Autonomic live adaptation of virtual networked environments in a multidomain infrastructure
Authors: Ruth Paul , Rhee Junghwan , Xu Dongyan , Goasguen Sebastien , Kennell Rick 
Published: July 2011

Abstract
The trend toward cloud-based services is creating the need for large scale shared distributed infrastructures. Behind many clouds lay shared distributed infrastructures formed through the federation of many resources residing in multiple domains. Such shared infrastructures enable massive amounts of aggregated computation resources to be shared among large numbers of users. The core technologies enabling these distributed clouds are machine and network virtualization. Virtualization is the technology that enables the execution of arbitrary distributed applications on top of these increasingly popular shared physical infrastructures.
In this paper, we go beyond supporting applications in the cloud and support autonomic adaptation of virtual computation environments as active, integrated entities. More specifically, driven by both dynamic availability of infrastructure resources and dynamic application resource demand, a virtual computation environment is able to automatically relocate itself across the infrastructure and scale its share of infrastructural resources. Such autonomic adaptation is transparent to both users of virtual environments and administrators of infrastructures, maintaining the look and feel of a stable, dedicated environment for the user. As our proof-of-concept, we present the design, implementation, and evaluation of a system called VIOLIN, which is composed of a virtual network of virtual machines capable of live migration across a multidomain physical infrastructure.
Cognitive, biochemical, and imaging profile of patients suffering from idiopathic normal pressure hydrocephalus
Authors: Tarnaris Andrew , Toma Ahmed K. , Pullen Emily , Chapman Miles D. , Petzold Axel , Cipolotti Lisa , Kitchen Neil D. , Keir Geoff , Lemieux Louis , Watkins Laurence D. 
Published: July 2011

IntroductionIt has still not been clearly established whether the cognitive deficits of idiopathic normal pressure hydrocephalus (iNPH) are caused by a disturbance in cerebrospinal fluid (CSF) dynamics or an underlying metabolic disturbance.ObjectiveTo identify the possible associations between biochemical markers, the neuroimaging characteristics, and cognitive deficits of patients undergoing investigations for possible iNPH.MethodsA CSF sample obtained during a lumbar puncture from 10 patients with iNPH was analyzed for several biochemical markers (lactate, 8‐isoprostane, vascular endothelial growth factor [VEGF], neurofilament heavy protein, glial fibrillary acidic protein, amyloid beta 1‐42, and total tau). All patients underwent a battery of neuropsychological testing and imaging as part of their selection process for their suitability for CSF diversion surgical procedure. Volumetric analysis of imaging was carried out measuring the ventricular volume (VV), intracranial volume (ICV), periventricular lucencies, deep white matter hyperintensities, and white matter (WM) volume, as well as their ratios.ResultsA significant negative correlation of preoperative symptom duration and total tau levels (R = −0.841, P = .002) was found. There was a significant positive correlation (R = 0.648, P = .043) between the levels of VEGF and the VV/ICV ratio. There was a significant positive correlation of the levels of glial fibrillary acidic protein and the VV/deep white matter hyperintensities ratio (R = 0.828, P = .006). A significant negative correlation was observed between the levels of neurofilament heavy protein and the VV/ICV ratio (R = −0.657, P = .039) and the WM volume (R = −0.778, P = .023). Lactate levels were lower for patients performing in the normal range on the Recognition Memory Test for faces. Patients who performed better in the Recognition Memory Test words test had higher ICV volumes. All the patients in this study showed below normal performance when the subcortical function was assessed.ConclusionThe positive correlation of VEGF with the severity of ventriculomegaly may indicate that this is because of the transmantle pressure gradient; this response may not be because of hypoxia but represents an attempt at neuroregeneration. The degree of reactive gliosis correlates inversely with the severity of WM lesions. Neuronal degeneration is negatively correlated with the volume of the WM in these patients. The small association of volumetry and the cognitive profile of these patients may be consistent with a direct biochemical disturbance being responsible for the cognitive deficit observed. Ongoing studies with set protocols for neuropsychological assessment and volumetric analysis are warranted to further elucidate on the preliminary results of the current study.
DEVELOPMENT AND ADMINISTRATIVE NORMS: THE OFFICE DU NIGER AND DECENTRALIZATION IN FRENCH SUDAN AND MALI
Authors: Diawara Mamadou 
Published: July 2011

ABSTRACTThis article analyses the historical roots of decentralization, a policy which is presented in the development world as the miracle cure to Third World evils. The text is based on the current literature on the topic as well as field research carried out in Mali in the Office du Niger region, which, already in the colonial period, represented a particular decentralization challenge. It offers a critical perspective on the concept of decentralization, which some trace back to the Middle Ages, and examines colonial experiences. How can the Malian state, inherited from the colonial state, decentralize everything whilst adopting the policy according to which the lands of the central delta of the Niger have been state-owned property since 1935? The aim is to show the analogy between problems encountered by the French colonial state and those that plague the Malian post-colonial state, whilst guarding against the sirens of a false authenticity reeking of neo-traditionalism.
‘INSTEAD OF BEGGING, I FARM TO FEED MY CHILDREN’: URBAN AGRICULTURE – AN ALTERNATIVE TO COPPER AND COBALT IN LUBUMBASHI
Authors: Tambwe Nyumbaiza , Rudolph Michael , Greenstein Ran 
Published: July 2011

ABSTRACTThe collapse of the mining company La Générale des Carrières et des Mines (GECAMINES) in the 1990s forced many unemployed workers in Lubumbashi to look at alternative means of survival. The post-GECAMINES era was characterized by acute economic crisis at a time of rapid population growth and increasing urban poverty. The object of this article is threefold: to demonstrate how Lubumbashi residents resorted to agricultural activities within and around the city; to identify reasons for success and failure from three case studies; and to categorize the types of agriculture that emerge. Data were collected by means of semi-structured interviews, in-depth questions and observation. One hundred farming households were selected and interviewed between November 2004 and March 2005. Data were analysed using thematic content analysis for qualitative aspects and SPSS for the quantitative information. Though the living conditions of 75 per cent of urban farmers declined despite the practice of urban agriculture, these conditions might have worsened without it. However, 20 per cent of the households in the sample succeeded in stabilizing their living conditions, even though they were unable to alleviate poverty completely. A few farmers (5 per cent) became food-secure through the practice of urban agriculture.
Light intensity, photoperiod duration, daily light flux and coral growth ofGalaxea fascicularisin an aquarium setting: a matter of photons?
Authors: Schutter Miriam , van der Ven Rosa M. , Janse Max , Verreth Johan A.J. , Wijffels René H. , Osinga Ronald 
Published: July 2011

Light is one of the most important abiotic factors influencing the (skeletal) growth of scleractinian corals. Light stimulates coral growth by the process of light-enhanced calcification, which is mediated by zooxanthellar photosynthesis. However, the quantity of light that is available for daily coral growth is not only determined by light intensity (i.e. irradiance), but also by photoperiod (i.e. the light duration time). Understanding and optimizing conditions for coral growth is essential for sustainable coral aquaculture. Therefore, in this study, the question was explored whether more light (i.e. more photons), presented either as irradiance or as light duration, would result in more growth. A series of nine genetically identical coral colonies ofGalaxea fascicularisL. were cultured for a period of 18 weeks at different light duration times (8 hours 150 μE m−2s−1:16 hours dark, 12 hours 150 μE m−2s−1:12 hours dark, 16 hours 150 μE m−2s−1:8 hours dark, 24 hours 150 μE m−2s−1:0 hours dark) and different irradiance levels (8 hours 150 μE m−2s−1:16 hours dark, 8 hours 225 μE m−2s−1:16 hours dark and 8 hours 300 μE m−2s−1:16 hours dark). Growth was determined every two weeks by measuring buoyant weight. Temperature, salinity and feeding levels were kept constant during the experiment. To detect possible acclimation of the corals to an increased light duration, rates of net photosynthesis and dark respiration were measured, hereby comparing coral colonies grown under an 8:16 hours light (150 μE m−2s−1):dark cycle with corals grown under a 16:8 hours light (150 μE m−2s−1):dark cycle. No increase in growth was detected with either increasing photoperiod or irradiance. Continuous lighting (24 hours 150 μE m−2s−1:0 hours dark) resulted in immediate bleaching and the corals died after 14 weeks. Hourly photosynthetic rates were significantly reduced in the 16 hour light treatment compared to the 8 hour light treatment. As a result, daily net photosynthetic rates were not significantly different, which may explain the observed specific growth rates. Acclimation to photoperiod duration appeared neither to be mediated by changes in chlorophyll-aconcentration nor zooxanthellae density. Based on the results of this study, we can conclude that the enhancing effect of light on coral growth is not only a matter of photons. Obviously, the availability of light was not limiting growth in these experiments and was probably in excess (i.e. stressful amounts). Other factors are discussed that play a role in determining growth rates and might explain our results.
Seasonal dynamics of subtidal macrophyte assemblages in Sobol Bay (Peter the Great Bay, Sea of Japan) in relation to depth
Authors: Skriptsova Anna V. , Levenets Irina R. 
Published: July 2011

This paper describes the species composition, vertical distribution, and the seasonal changes in the biomass of subtidal macrophytes in Sobol Bay (Peter the Great Bay, Sea of Japan). The samples were collected in the depth-range from 0.5 to 4 m. A total of 65 macrophyte species were identified, among which were 10 species of Chlorophyta, 17 of Phaeophyceae, 37 of Rhodophyta and 1 of Magnoliophyta. Multivariate analyses were performed to detect spatial and temporal variations. Maximum species richness was registered in June, with a particularly dramatic biomass increase of brown algae. Both the number of species and the biomass of macrophytes decreased with increasing depth. Depth clearly affected the patterns of seasonal fluctuations of the species composition and biomass. In the study area, the species composition of the shallow-water algal assemblages was more stable throughout the year compared to that of the algal assemblages found in deeper waters. In total, four macrophyte assemblages were identified in the bay. A Phyllospadix iwatensis and Coccophora langsdorfii dominated assemblage occupied muddy-gravel bottoms in depths from 0.5 to 2 m throughout the year. An assemblage, co-dominated by annual brown algae Desmarestia viridis and Costaria costata, occurred at depths more than 3 m at late spring. Two other assemblages occurred on the rock and boulder bottom at 0.5–2 m depths, but they were temporally separated. An assemblage co-dominated by annual laminarian algae (Undaria pinnatifida and Costaria costata) developed at late spring and was succeeded in the autumn and winter by a Tichocarpus crinitus, Ulva lactuca, Sargassum pallidum and Codium fragile co-dominated assemblage. A comparison between the data obtained in the present study and the results of a previous study conducted in 1927 shows that the macrophytes assemblages in Sobol Bay underwent little change.
Soil fertility and crop yields in long-term organic and conventional cropping systems in Eastern Nebraska
Authors: Wortman Sam E. , Galusha Tomie D. , Mason Stephen C. , Francis Charles A. 
Published: July 2011

AbstractOrganic agriculture aims to build soil quality and provide long-term benefits to people and the environment; however, organic practices may reduce crop yields. This long-term study near Mead, NE was conducted to determine differences in soil fertility and crop yields among conventional and organic cropping systems between 1996 and 2007. The conventional system (CR) consisted of corn (Zea maysL.) or sorghum (Sorghum bicolor(L.) Moench)–soybean (Glycine max(L.) Merr.)–sorghum or corn–soybean, whereas the diversified conventional system (DIR) consisted of corn or sorghum–sorghum or corn–soybean–winter wheat (wheat,Triticum aestivumL.). The animal manure-based organic system (OAM) consisted of soybean–corn or sorghum–soybean–wheat, while the forage-based organic system (OFG) consisted of alfalfa (Medicago sativaL.)–alfalfa–corn or sorghum–wheat. Averaged across sampling years, soil organic matter content (OMC), P, pH, Ca, K, Mg and Zn in the top 15 cm of soil were greatest in the OAM system. However, by 2008 OMC was not different between the two organic systems despite almost two times greater carbon inputs in the OAM system. Corn, sorghum and soybean average annual yields were greatest in either of the two conventional systems (7.65, 6.36 and 2.60 Mg ha−1, respectively), whereas wheat yields were greatest in the OAM system (3.07 Mg ha−1). Relative to the mean of the conventional systems, corn yields were reduced by 13 and 33% in the OAM and OFG systems, respectively. Similarly, sorghum yields in the OAM and OFG systems were reduced by 16 and 27%, respectively. Soybean yields were 20% greater in the conventional systems compared with the OAM system. However, wheat yields were 10% greater in the OAM system compared with the conventional DIR system and 23% greater than yield in the OFG system. Alfalfa in the OFG system yielded an average of 7.41 Mg ha−1annually. Competitive yields of organic wheat and alfalfa along with the soil fertility benefits associated with animal manure and perennial forage suggest that aspects of the two organic systems be combined to maximize the productivity and sustainability of organic cropping systems.
Thermodynamics of copper and zinc distribution in the cyanobacterium
Synechocystis
PCC 6803
Authors: Badarau Adriana , Dennison Christopher 
Published: July 2011

Copper is supplied to plastocyanin for photosynthesis and cytochrome
c
oxidase for respiration in the thylakoids of
Synechocystis
PCC 6803 by the membrane-bound P-type ATPases CtaA and PacS, and the metallochaperone Atx1. We have determined the Cu(I) affinities of all of the soluble proteins and domains in this pathway. The Cu(I) affinities of the trafficking proteins range from 5 × 10
16
to 5 × 10
17
M
-1
at pH 7.0, consistent with values for homologues. Unusually, Atx1 binds Cu(I) significantly tighter than the metal-binding domains (MBDs) of CtaA and PacS (CtaA
N
and PacS
N
), and equilibrium copper exchange constants of approximately 0.2 are obtained for transfer to the MBDs. Dimerization of Atx1 increases the affinity for Cu(I), but the loop 5 His61 residue has little influence. The MBD of the zinc exporter ZiaA (ZiaA
N
) exhibits an almost identical Cu(I) affinity, and Cu(I) exchange with Atx1, as CtaA
N
and PacS
N
, and the relative stabilities of the complexes must enable the metallochaperone to distinguish between the MBDs. The binding of potentially competing zinc to the trafficking proteins has been studied. ZiaA
N
has the highest Zn(II) affinity and thermodynamics could be important for zinc removal from the cell. Plastocyanin has a Cu(I) affinity of 2.6 × 10
17
M
-1
, 15-fold tighter than that of the Cu
A
site of cytochrome
c
oxidase, highlighting the need for specific mechanisms to ensure copper delivery to both of these targets. The narrow range of Cu(I) affinities for the cytoplasmic copper proteins in
Synechocystis
will facilitate relocation when copper is limiting.
Pathway and mechanism of drug binding to G-protein-coupled receptors
Authors: Dror Ron O. , Pan Albert C. , Arlow Daniel H. , Borhani David W. , Maragakis Paul , Shan Yibing , Xu Huafeng , Shaw David E. 
Published: July 2011

How drugs bind to their receptors—from initial association, through drug entry into the binding pocket, to adoption of the final bound conformation, or “pose”—has remained unknown, even for G-protein-coupled receptor modulators, which constitute one-third of all marketed drugs. We captured this pharmaceutically critical process in atomic detail using the first unbiased molecular dynamics simulations in which drug molecules spontaneously associate with G-protein-coupled receptors to achieve final poses matching those determined crystallographically. We found that several beta blockers and a beta agonist all traverse the same well-defined, dominant pathway as they bind to theβ1- andβ2-adrenergic receptors, initially making contact with a vestibule on each receptor’s extracellular surface. Surprisingly, association with this vestibule, at a distance of 15 Å from the binding pocket, often presents the largest energetic barrier to binding, despite the fact that subsequent entry into the binding pocket requires the receptor to deform and the drug to squeeze through a narrow passage. The early barrier appears to reflect the substantial dehydration that takes place as the drug associates with the vestibule. Our atomic-level description of the binding process suggests opportunities for allosteric modulation and provides a structural foundation for future optimization of drug–receptor binding and unbinding rates.
Structural basis for alginate secretion across the bacterial outer membrane
Authors: Whitney John C. , Hay Iain D. , Li Canhui , Eckford Paul D. W. , Robinson Howard , Amaya Maria F. , Wood Lynn F. , Ohman Dennis E. , Bear Christine E. , Rehm Bernd H. , Lynne Howell P. 
Published: July 2011

Pseudomonas aeruginosa
is the predominant pathogen associated with chronic lung infection among cystic fibrosis patients. During colonization of the lung,
P. aeruginosa
converts to a mucoid phenotype characterized by the overproduction of the exopolysaccharide alginate. Secretion of newly synthesized alginate across the outer membrane is believed to occur through the outer membrane protein AlgE. Here we report the 2.3 Å crystal structure of AlgE, which reveals a monomeric 18-stranded β-barrel characterized by a highly electropositive pore constriction formed by an arginine-rich conduit that likely acts as a selectivity filter for the negatively charged alginate polymer. Interestingly, the pore constriction is occluded on either side by extracellular loop L2 and an unusually long periplasmic loop, T8. In halide efflux assays, deletion of loop T8 (ΔT8-AlgE) resulted in a threefold increase in anion flux compared to the wild-type or ΔL2-AlgE supporting the idea that AlgE forms a transport pathway through the membrane and suggesting that transport is regulated by T8. This model is further supported by in vivo experiments showing that complementation of an
algE
deletion mutant with ΔT8-AlgE impairs alginate production. Taken together, these studies support a mechanism for exopolysaccharide export across the outer membrane that is distinct from the Wza-mediated translocation observed in canonical capsular polysaccharide export systems.
Is Interstitial Velocity a Good Predictor of Salmonid Embryo Survival?
Authors: Malcolm I. A. , Youngson A. F. , Soulsby C. , Imholt C. , Fryer R. J. 
Published: July 2011

AbstractInterstitial velocity within spawning bed substrates is frequently used to predict salmonid embryo survival and often forms the basis of habitat assessment or sediment‐based predictive models. In this study, the relationships between interstitial velocity, hyporheic dissolved oxygen (DO), and survival of Atlantic salmon Salmo salar embryos were examined in an experimental field study that incorporated natural complexity in the hyporheic environment. Hyporheic DO and interstitial velocity were not clearly related over the observed range of velocities. There was strong evidence of a relationship between survival and DO but only weak evidence of a relationship with interstitial velocity. Conceptual models of hyporheic environmental variation and salmonid embryo survival should include the appropriate range of environmental processes. Given the findings of this study, we suggest that interstitial velocity should not be used to assess or predict spawning habitat quality; direct measurements of DO offer a more defensible approach.
Rural–Urban Differences in Childcare Subsidy Use and Employment Stability
Authors: Davis Elizabeth E. , Grobe Deana , Weber Roberta B. 
Published: July 2011

AbstractLocal economic disparities, particularly lower average wages, higher overall unemployment rates and higher poverty rates may lead to rural–urban differences in the use of public programs designed to support working low‐income families. This study analyzes the dynamics of program participation and employment stability for rural and urban families in the Oregon childcare subsidy program. While families' demographic characteristics, employment stability, and participation in work support programs were similar, families in rural noncore counties tended to make less use of public assistance, including childcare subsidies, food stamps and welfare, than did families in metropolitan and micropolitan counties.
Does Agricultural Trade Liberalization Reduce Rural Welfare in Less Developed Countries? The Case of CAFTA
Authors: Taylor J. Edward , Naude Antonio Yúnez , Jesurun‐Clements Nancy 
Published: July 2011

AbstractFindings from aggregate economy‐wide models suggest that removing tariffs on agricultural imports is detrimental to rural welfare in less developed countries. This paper explores the rural welfare effects of agricultural trade liberalization called for under the Central American Free Trade Agreement (CAFTA), using a disaggregated rural economy‐wide model nesting a series of agricultural household models. Lower tariffs reduce nominal incomes for nearly all rural household groups in El Salvador, Guatemala, Honduras and Nicaragua. However, they also lower consumption costs substantially. The net effect on rural households' welfare is positive in most cases, implying that pre‐CAFTA agricultural protection policies are disadvantageous for most rural household groups.