bluuebunny/crossref_metadata_2025_split huggingface dataset:
Beta‐diversity gradients of butterflies along productivity axes
Authors: Andrew Margaret E. , Wulder Michael A. , Coops Nicholas C. , Baillargeon Guy 
Published: May 2011

ABSTRACTAim  Several lines of evidence suggest that beta diversity, or dissimilarity in species composition, should increase with productivity: (1) the latitudinal species richness gradient is most closely related to productivity and associated latitudinal beta‐diversity relationships have been described, and (2) the scale dependence of the productivity–diversity relationship implies that there should be a positive productivity–beta‐diversity relationship. However, such a pattern has not yet been demonstrated at broad scales. We test if there is a gradient of increasing beta diversity with productivity.Location  Canada.Methods  Canada was clustered into regions of similar productivity regimes along three remotely sensed productivity axes (minimum and integrated annual productivity, seasonality of productivity) and elevation. The overall (βj), turnover (βsim) and nestedness (βnes) components of beta diversity within each productivity regime were estimated with pairwise dissimilarity metrics and related to cluster productivity with partial linear regression and with spatial autoregression. Tests were performed for all species, productivity breadth‐based subsets (e.g. species occurring in many and a moderate number of productivity regimes), and pre‐ and post‐1970 butterfly records. Beta diversity between adjacent clusters along the productivity gradients was also evaluated.Results  Within‐cluster βj and βsim increased with productivity and decreased with seasonality. The converse was true for βnes. All species subsets responded similarly; however, productivity–beta‐diversity relationships were weaker for the post‐1970 temporal subset and strongest for species of moderate breadth. Between‐cluster beta diversity (βj) and nestedness (βnes) declined with productivity.Main conclusions  As predicted, beta diversity of communities within productivity regimes was observed to increase with productivity. This pattern was driven largely by a gradient of species turnover. Therefore, beta diversity may make an important contribution to the broad‐scale gradient of species richness with productivity. However, this species richness gradient dominates regional beta diversity between productivity regimes, resulting in decreasing between‐productivity dissimilarity with productivity driven by a concurrent decline in nestedness.
‘Street‐level Bureaucracy’ Revisited: The Changing Face of Frontline Discretion in Adult Social Care in England
Authors: Ellis Kathryn 
Published: May 2011

AbstractThis reassessment of the continuing significance of Lipsky's (1980) work on ‘street‐level bureaucracy’ for frontline decision making is based on a retrospective review of the author's research on assessment practice in adult social care in England. The studies span the past two decades during which time successive governments have restructured and modernized social services departments. When these were established in 1970, they represented the high watermark of bureau‐professionalism – a mode of administration which dominated social welfare at the time Lipsky was writing. The subsequent dismantling of bureau‐professionalism calls into question the validity of his findings, and the author draws on her own research to assess conflicting views about the impact of social care reforms on the discretion which social workers exercise as street‐level bureaucrats. She concludes that the distinct types of discretion to emerge from her findings, represented in a taxonomy, are shaped by the differing micro environments of frontline practice which, in turn, affect the relative force of managerialism, professionalism and user empowerment in countering the defensive exercise of discretion described by Lipsky. Whilst her analysis affirms the continuing significance of Lipsky's analysis, it also points to the need for some revision to accommodate major shifts in welfare administration since the publication of his work. She highlights the potential relevance of these insights for investigating the next planned transformation of adult social care, personalization, as well as for the implementation literature more widely.
Choosing Whether to Buy or Make: The Contracting Out of Employment Reintegration Services by Dutch Municipalities
Authors: Plantinga Mirjam , de Ridder Ko , Corra Alex 
Published: May 2011

AbstractThe Western welfare states are under reform. An important part of these reforms is the introduction of market type mechanisms for the deliverance of public services. Over the years, many countries have chosen to contract out employment reintegration services. The underlying notion of contracting out is the belief that the introduction of market elements in the production of public services increases effectiveness and efficiency. In addition to the cost benefit argument for contracting out public services, ideology is often brought forward as an important factor explaining why public services are provided in‐house. In this article, we analyze to what extent cost benefit arguments and ideology affect the make or buy decision of Dutch municipalities. The Dutch employment reintegration market poses an interesting case in point since Dutch municipalities have the option to either provide employment reintegration services themselves or to buy services on the market. Our analysis shows that cost benefit arguments do not play a role in the make or buy decision of Dutch municipalities. Ideology, however, does. Municipalities that adhere to the principles of New Public Management more often opt to buy employment reintegration services on the market. Also the outcomes of municipal elections have been found to be of importance – left‐wing municipalities more often choose in‐house service provision.
Subverting Social Policy on the Front Line: Agencies of Resistance in the Delivery of Services
Authors: Prior David , Barnes Marian 
Published: May 2011

AbstractAn understanding of policy implementation issues in many of the core fields of social policy requires attention to the mode of service delivery that is characteristic of those fields: face‐to‐face interaction between frontline service staff and service users. A focus on implementation as interaction between these groups reveals the significance of ‘agency’ to the analysis of why and how certain social policy outcomes occur – and in particular why outcomes may sometimes be different from those anticipated by formal policy objectives. This article considers how the agency of workers and users shapes the processes of mediation, negotiation and adaptation that occur in different service delivery contexts, and identifies ways in which resistance to intended policy outcomes, and to the practices expected to deliver them, is formed and expressed. Drawing on a wide range of empirical research material, the article shows how agencies of resistance produce outcomes that are uncertain, fragile and contested, and whose effect can be the subversion of formal policy intentions.
North‐South Migration in Ghana: What Role for the Environment?
Authors: van der Geest Kees 
Published: May 2011

AbstractThe purpose of this paper is to determine the importance of the environment as a driver of North‐South migration in Ghana. Almost one in every five people born in northern Ghana is living in southern Ghana. Interviews with 203 migrant farmers suggest that migration from the North to the South is, to a large extent, environmentally induced. Many Northerners decided to migrate because of poor agro‐ecological conditions at home combined with easy access to fertile lands in the more humid destination area. The interviews with migrant farmers yielded several insights that are relevant for the environmental refugee debate. Firstly, environmental pull appears to be at least as important as environmental push. Secondly, scarcity of fertile land was mentioned much more often as a reason to migrate than climate change or erratic rainfall. Thirdly, none of the respondents ascribed the migration decision to sudden‐onset environmental stress. If the environment is indeed an important driver of migration, one would expect migration rates to be higher in places with and times of more severe scarcity. A cross‐sectional analysis of migration propensities and natural resources scarcity confirms that out‐migration rates are significantly higher in poorly endowed districts. A longitudinal analysis of migration and rainfall shows that the period of worst environmental stress ‐‐ during the Sahelian droughts of the late 1970s and early 1980s ‐‐ was a time of reduced out‐migration from northern Ghana. In this period of northern Ghana’s migration history, economic and political factors weighed heavier than environmental factors. The picture that emerges for northern Ghana is not one of distress migration in the face of environmental disaster but rather of migration as a way of dealing with structural environmental scarcity.
Environmental Degradation and Migration on Hispaniola Island
Authors: Alscher Stefan 
Published: May 2011

AbstractSharing the same island, the Dominican Republic and Haiti are confronting similar environmental challenges. Located on the path of tropical storms, Hispaniola Island is frequently exposed to natural disasters like heavy rainfall, flooding and landslides, aggravated by human‐induced environmental degradation. At the same time, the differences between the two nations are extreme. Haiti is the poorest country in the Western Hemisphere and a well‐known case in environmental studies as nearly all of its forests have disappeared. In the Dominican Republic, a middle‐income country known for its beaches and tourist resorts, deforestation and soil erosion is also a problem, but to a much lower extent compared to its neighbour state. Above all, the rural economy in both countries is suffering from both sudden disasters and slow‐onset environmental degradation. Together with the lack or withdrawal of state support, the incentives for migration as an adaptation strategy are increasing in this panorama of environmental degradation and economic losses. On the basis of field research in selected regions of both countries, this paper analyses the impacts of environmental change on internal and international migration flows on Hispaniola Island.
Flooding and Relocation: The Zambezi River Valley in Mozambique
Authors: Stal Marc 
Published: May 2011

AbstractSince the 1980’s there has been an increasing debate throughout the world, that argues whether environmental degradation is a major cause of migration. Scientists claimed there were millions of “environmental refugees” in the late 1980s. The discussion of the links between environmental change and migration have since then been widely debated, especially because of the lack of empirical data on the linkages of the environment and migration. Within the last years the Nobel price winning International Panel on Climate Change (IPCC, 2007) raised awareness about future impacts of climate change and stated that extreme weather events will occur more frequently and the number of people affected will be highest in the low‐lying deltas of Asia and Africa.Heavy rain in south eastern Africa in early 2008 flooded the low‐lying river areas along the Zambezi River in Central Mozambique and displaced up to 80,000 people ‐‐ the second such occurrence within two years. This number adds to tens of thousands of people already displaced from floods and cyclones during 2000, 2001 and 2007. Flooding in Mozambique provides a picture of the vulnerability many developing countries experience vis‐à‐vis extreme climate events. Resettlement has become a policy of last resort for a government trying to ensure safety in a populated area. Mozambique has in recent years become a prominent example of environmentally induced displacement/migration caused by flooding, and the efforts of a government to balance the safety of threatened people with the need to earn livelihoods on floodplains. Hence, this paper aims to understand the impacts of current extreme weather events, especially for a region of the world where the population is surviving via subsistence economy. This paper intends to decrease the lack of data on the linkages between the environment, displacement and migration and identify the major issues in dealing with these impacts.
Protective effect of the octadecaneuropeptide on hydrogen peroxide‐induced oxidative stress and cell death in cultured rat astrocytes
Authors: Hamdi Yosra , Masmoudi‐Kouki Olfa , Kaddour Hadhemi , Belhadj Feten , Gandolfo Pierrick , Vaudry David , Mokni Meherzia , Leprince Jérôme , Hachem Raya , Vaudry Hubert , Tonon Marie‐Christine , Amri Mohamed 
Published: May 2011

J. Neurochem. (2011) 118, 416–428.AbstractOxidative stress, resulting from accumulation of reactive oxygen species (ROS), plays a critical role on astrocyte death associated with neurodegenerative diseases. Astroglial cells produce endozepines, a family of biologically active peptides that have been implicated in cell protection. Thus, the purpose of the present study was to investigate the potential protective effect of one of the endozepines, the octadecaneuropeptide ODN, on hydrogen peroxide (H2O2)‐induced oxidative stress and cell death in rat astrocytes. Incubation of cultured astrocytes with graded concentrations of H2O2 for 1 h provoked a dose‐dependent reduction of the number of living cells as evaluated by lactate dehydrogenase assay. The cytotoxic effect of H2O2 was associated with morphological modifications that were characteristic of apoptotic cell death. H2O2‐treated cells exhibited high level of ROS associated with a reduction of both superoxide dismutases (SOD) and catalase activities. Pre‐treatment of astrocytes with low concentrations of ODN dose‐dependently prevented cell death induced by H2O2. This effect was accompanied by a marked attenuation of ROS accumulation, reduction of mitochondrial membrane potential and activation of caspase 3 activity. ODN stimulated SOD and catalase activities in a concentration‐dependent manner, and blocked H2O2‐evoked inhibition of SOD and catalase activities. Blockers of SOD and catalase suppressed the effect of ODN on cell survival. Taken together, these data demonstrate for the first time that ODN is a potent protective agent that prevents oxidative stress‐induced apoptotic cell death.
In Vivo Evaluation of the “TinyPump” as a Pediatric Left Ventricular Assist Device
Authors: Kitao Takashi , Ando Yusuke , Yoshikawa Masaharu , Kobayashi Mariko , Kimura Taro , Ohsawa Hideyuki , Machida Shinya , Yokoyama Naoyuki , Sakota Daisuke , Konno Tomohiro , Ishihara Kazuhiko , Takatani Setsuo 
Published: May 2011

AbstractPediatric patients with end‐stage heart failure require mechanical circulatory support (MCS) just as adults do. In order to meet the special requirements for neonates' and infants' MCS, pediatric circulatory support devices must be compact with low priming volume, easily controllable with low flow, less traumatic for blood cells and tissues, and biocompatible with minimum anticoagulation. We have designed and developed a miniature rotary centrifugal blood pump, “TinyPump,” with a priming volume of 5 mL, which has already demonstrated its controllable performance for low flow and durability in vitro. To evaluate the feasibility of the TinyPump as a left ventricular assist device (LVAD) suitable for neonates and infants, we have examined the biocompatibility and hemodynamic performance of the TinyPump in a pediatric animal model using Shiba goats. The TinyPump is a miniaturized centrifugal pump weighing 150 g comprising a disposable pump head with a 30‐mm diameter impeller having six straight‐vanes and a reusable motor driver. The impeller in the pump head is supported by a hydrodynamic bearing at its center and is driven by radial magnetic force coupled to the motor driver. TinyPump implantations were performed in 22 Shiba goats (17 female and 5 male), with body weights ranging from 8.4 to 27.2 kg. Under gas anesthesia, via left lateral thoracotomy, a 22 Fr inflow cannula was inserted through the left ventricular apex, while a 6‐mm outflow graft was anastomosed to the descending aorta, which were then connected to a TinyPump mounted on the animal's back. Postoperative hemodynamic monitoring included heart rate, arterial and central venous pressure, pump flow, and rotation speed. Target pump flow in all animals was maintained at 0.9 ± 0.1 L/min, which is approximately half the normal pulmonary artery flow measured in control animals. Blood samples were collected to evaluate peripheral organ functions, hemolysis, and thrombosis. Goats were divided into three groups—acute phase (6 h; n = 4), subchronic phase (6 h 2 postoperative days [POD]; n = 11), and chronic phase (3 POD–16 POD; n = 8)—based on their survival duration. In the early experiments, hemolysis and thrombi formation at the impeller bearing resulted in termination of the study. Subsequent modifications of the bearing design, pump housing design, and magnetic coupling force helped to minimize the hemolysis and thrombi formation, prolonging the survival duration of the Shiba goats to 2 weeks with minimum adverse effects on the blood components and organ functions. With further experiments and improvements in pump durability and hemocompatibility, the TinyPump can serve as a suitable circulatory support device for neonates and infants bridging to heart transplantation as well as to heart recovery.
Delivery of the Bioactive Gas Hydrogen Sulfide During Cold Preservation of Rat Liver: Effects on Hepatic Function in an Ex vivo Model
Authors: Balaban Cecilia L. , Rodriguez Joaquín V. , Guibert Edgardo E. 
Published: May 2011

AbstractThe insults sustained by transplanted livers (hepatectomy, hypothermic preservation, and normothermic reperfusion) could compromise hepatic function. Hydrogen sulfide (H2S) is a physiologic gaseous signaling molecule, like nitric oxide (NO) and carbon monoxide (CO). We examined the effect of diallyl disulfide as a H2S donor during hypothermic preservation and reperfusion on intrahepatic resistance (IVR), lactate dehydrogenase (LDH) release, bile production, oxygen consumption, bromosulfophthalein (BSP) depuration and histology in an isolated perfused rat liver model (IPRL), after 48 h of hypothermic storage (4°C) in University of Wisconsin solution (UW, Viaspan). Livers were retrieved from male Wistar rats. Three experimental groups were analyzed: Control group (CON): IPRL was performed after surgery; UW: IPRL was performed in livers preserved (48 h—4°C) in UW; and UWS: IPRL was performed in livers preserved (48 h—4°C) in UW in the presence of 3.4 mM diallyl disulfide. Hypothermic preservation injuries were manifested at reperfusion by a slight increment in IHR and LDH release compared with the control group. Also, bile production for the control group (1.32 µL/min/g of liver) seemed to be diminished after preservation by 73% in UW and 69% in UW H2S group at the end of normothermic reperfusion. Liver samples analyzed by hematoxylin/eosin clearly showed the deleterious effect of cold storage process, partially reversed (dilated sinusoids and vacuolization attenuation) by the addition of a H2S delivery compound to the preservation solution. Hepatic clearance (HC) of BSP was affected by cold storage of livers, but there were no noticeable differences between livers preserved with or without diallyl disulfide. Meanwhile, livers preserved in the presence of H2S donor showed an enhanced capacity for BSP uptake (kACON = 0.29 min−1; kAUW = 0.29 min−1; kAUWS = 0.36 min−1). In summary, our animal model suggests that hepatic hypothermic preservation for transplantation affects liver function and hepatic depuration of BSP, and implies that the inclusion of an H2S donor during hypothermic preservation could improve standard methods of preparing livers for transplant.
Dendronized Polyaniline Nanotubes for Cardiac Tissue Engineering
Authors: Moura Renata Mendes , de Queiroz Alvaro Antonio Alencar 
Published: May 2011

AbstractToday, nanobiomaterials represent a very important class of biomaterials because they differ dramatically in their bulk precursors. The properties of these materials are determined by the size and morphology, thus creating a fascinating line in their physicochemical properties. Polyaniline nanotubes (PANINTs) are one of the most promising nanobiomaterials for cardiac tissue engineering applications due to their electroactive properties. The biocompatibility and low hydrophilic properties of PANINTs can be improved by their functionalization with the highly hydrophilic polyglycerol dendrimers (PGLDs). Hydrophilicity plays a fundamental role in tissue regeneration and fundamental forces that govern the process of cell adhesion and proliferation. In this work, the biocompatible properties and cardiomyocyte proliferation onto PANINTs modified by PGLD are described. PGLDs were immobilized onto PANINTs via surface‐initiated anionic ring‐opening polymerization of glycidol. The microstructure and morphology of PGLD‐PANINTs was determined by X‐ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. The cardiac cell growth on the PGLD‐PANINTs was investigated. The PGLD‐coated PANINTs showed noncytotoxic effects to Chinese hamster ovary cells. It was observed that the application of microcurrent stimulates the differentiation of cardiac cells cultured on PGLD‐PANINTs scaffolds. The electroactive and biocompatible results of PGLD‐PANINTs observed in this work demonstrate the potential of this nanobiomaterial for the culture of cardiac cells and open the possibility of using this material as a biocompatible electroactive three‐dimensional matrix in cardiac tissue engineering.
Implantable Centrifugal Blood Pump With Dual Impeller and Double Pivot Bearing System: Electromechanical Actuator, Prototyping, and Anatomical Studies
Authors: Bock Eduardo , Antunes Pedro , Leao Tarcisio , Uebelhart Beatriz , Fonseca Jeison , Leme Juliana , Utiyama Bruno , da Silva Cibele , Cavalheiro Andre , Filho Diolino Santos , Dinkhuysen Jarbas , Biscegli Jose , Andrade Aron , Arruda Celso 
Published: May 2011

AbstractAn implantable centrifugal blood pump has been developed with original features for a left ventricular assist device. This pump is part of a multicenter and international study with the objective to offer simple, affordable, and reliable devices to developing countries. Previous computational fluid dynamics investigations and wear evaluation in bearing system were performed followed by prototyping and in vitro tests. In addition, previous blood tests for assessment of normalized index of hemolysis show results of 0.0054 ± 2.46 × 10−3 mg/100 L. An electromechanical actuator was tested in order to define the best motor topology and controller configuration. Three different topologies of brushless direct current motor (BLDCM) were analyzed. An electronic driver was tested in different situations, and the BLDCM had its mechanical properties tested in a dynamometer. Prior to evaluation of performance during in vivo animal studies, anatomical studies were necessary to achieve the best configuration and cannulation for left ventricular assistance. The results were considered satisfactory, and the next step is to test the performance of the device in vivo.