bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluid dynamics and subsurface sediment mobilization processes: an overview from Southeast Caribbean
Authors: Deville Éric , Guerlais Sophie‐Hélène , Lallemant Siegfried , Schneider Frédéric
Published: May 2010

This paper discusses the origin and the dynamics of subsurface sediment mobilization processes in tectonically mobile regions and shale‐rich environment. This is illustrated by the example of Trinidad and the south of the Barbados prism. In this area of the southeast Caribbean, geophysical acquisitions have spectacularly shown the widespread development of sediment mobilization features in the interference area between the southern part of the Barbados prism and the active turbidite system of the Orinoco. Numerous mud volcanoes are especially developed along ramp anticline crests through hydraulic fracture systems. The area also exhibits trends of structures that correspond to massive uplifts of well‐preserved turbidite and hemipelagic sediments that cut up the surrounding sediments. Some of these structures are complicated by the development of collapse structures, calderas and superimposed mud volcanoes. The mobilized sediments expelled by the mud volcanoes are not only liquefied argillaceous but also fine sandy material from deep horizons, and various shallower formations pierced by the mud conduits. Both in the Barbados prism and in Trinidad, the expelled mud is rich in thin, angular and mechanically damaged quartz grains, which are probably cataclastic flows issued from sheared and collapsed deep sandy reservoirs. The exotic clasts and breccias result mostly from hydraulic fracturing. In Trinidad, the gas phase is mainly deep thermogenic methane associated with hydrocarbon generation at depth. Subsurface sediment mobilization notably differs from salt mobilization by the role taken by the fluid dynamics that control overpressured shale mobilization and induce sediment liquefaction. A reaction chain of several deformation processes develops around the conduits. Massive sedimentary uplift corresponds to large movements of stratified solid levels, possibly due to the tectonic inversion of pre‐existing mud volcano systems. All these phenomena are controlled by the development of overpressure at depth. No evidence for piercing shale diapirs has been observed in the area studied.
Autonomy, evidence and intuition: nurses and decision‐making
Authors: Traynor Michael , Boland Maggie , Buus Niels
Published: May 2010

traynor m., boland m. & buus n. (2010) Autonomy, evidence and intuition: nurses and decision‐making. Journal of Advanced Nursing 66(7), 1584–1591.

Title.  Autonomy, evidence and intuition: nurses and decision‐making.

Aim.  This paper is a report of a study conducted to examine how nurses represent professional clinical decision‐making processes, and to determine what light Jamous and Peloille’s ‘Indeterminacy/Technicality ratio’ concept can shed on these representations.

Background.  Classic definitions of professional work feature autonomy of decision‐making and control over the field of work. Sociologists Jamous and Peloille have described professional work as being high in ‘indeterminacy’ (the use of tacit judgements) relative to technicality (activity able to be codified). The rise of the evidence‐based practice movement has been seen as increasing the realm of technical decision‐making in healthcare, and it is relevant to analyse nurses’ professional discourse and study how they respond to this increase.

Method.  Three focus groups with qualified nurses attending post‐qualifying courses at a London university were held in 2008. Participants were asked to talk about influences on their decision‐making. The discussions were tape‐recorded, transcribed and subjected to discourse analysis.

Findings.  Participants described their decision‐making as influenced by both indeterminate and technical features. They acknowledged useful influences from both domains, but pointed to their personal ‘experience’ as the final arbiter of decision‐making. Their accounts of decision‐making created a sense of professional autonomy while at the same time protecting it against external critique.

Conclusion.  Pre‐ and post‐registration nurse education could encourage robust discussion of the definition and roles of ‘irrational’ aspects of decision‐making and how these might be understood as components of credible professional practice.
Nurses’ intention to leave the profession: integrative review
Authors: Flinkman Mervi , Leino‐Kilpi Helena , Salanterä Sanna
Published: May 2010

flinkman m., leino‐kilpi h. & salanterä s. (2010) Nurses’ intention to leave the profession: integrative review. Journal of Advanced Nursing 66(7), 1422–1434.

Title.  Nurses’ intention to leave the profession: integrative review.

Aim.  This paper is a report of a study conducted to (1) review and critique the published empirical research on nurses’ intention to leave the profession and (2) synthesize the findings across studies.

Background.  Lack of nurses and nurse turnover represent problems for the healthcare system in terms of cost, the ability to care for patients and the quality of care. At a time of current nursing shortage, it is important to understand the reasons why nurses intend to leave the profession.

Data sources.  A review was conducted through an initial search of MEDLINE, CINAHL and PsycINFO computerized databases for the period from 1995 to July 2009. The keywords for the search were: Nurs* AND (Personnel turnover OR Career Mobility). Research on nurses’ organizational turnover was excluded.

Review methods.  An integrative literature review was carried out using Cooper’s five‐stage methodology provided a framework for data collection, analysis and synthesis.

Results.  A total of 31 studies matching the inclusion criteria were identified. Variety in samples, measurement instruments and measures of intention to leave led to difficulties when attempting to compare or generalize study findings. A number of variables influencing nurses’ intention to leave the profession were identified, including demographic, work‐related and individual‐related variables.

Conclusions.  Further research is needed using sound measurement instruments, consistent measures of leaving intention and more rigorous sampling. More in‐depth research is needed to give nurses opportunities to explain in their own words the reasons for their intentions to leave.
Nurse‐led clinics for strict hypertension control are effective long term: a 7 year follow‐up study
Authors: Woodward A. , Wallymahmed M. , Wilding J. P. , Gill G. V.
Published: May 2010

Diabet. Med. 27, 933–937 (2010)

Aims  The primary aim was to assess long‐term blood pressure in 110 patients with Type 2 diabetes who had achieved optimal blood pressure control during attendance at a protocol‐based nurse‐led hypertension intensive intervention clinic 7 years previously. The secondary aim was to assess modifiable cardiovascular risk factor status.

Methods  One hundred and ten patients who attended the clinic during 2000–2002 were selected to reattend to have their blood pressure measured to the same standard as it was during the intensive intervention clinic, by the same specialist nurse. Treatment details were recorded.

Results  Of the 110 patients, 36 (33%) had died; 69 (63%) of the remaining 74 patients were eligible to be contacted by letter; and 35 (51%) agreed to reattend. Age was 70 ± 9 years; 21 (60%) were male; and the duration of diabetes was 17 ± 7 years. Compared with 7 years previously, there was no difference in blood pressure control (systolic 130 ± 17 vs. 131 ± 16 mmHg, P = 0.62; diastolic 68 ± 9 vs. 65 ± 9 mmHg, P = 0.11). The number of patients with blood pressure <130/80 mmHg remained the same: 17 (49%) vs. 17 (49%; P > 0.99). During the 7 year period, 14 (40%) vs. 20 (57%) had macrovascular disease (P = 0.23), and 14 (40%) vs. 19 (54%) microvascular disease (P = 0.33). Thirteen (37%) vs. 18 (51%) were taking three or more antihypertensive drugs (P = 0.33), and 26 (74%) vs. 28 (80%) angiotensin‐converting enzyme inhibitor or angiotensin receptor blocker (P = 0.77).

Conclusions  Optimal blood pressure control was sustained with no significant changes to antihypertensive medication, demonstrating the effectiveness of a protocol‐based nurse‐led clinic in achieving strict BP control.
The prevalence of depressive symptoms in a white European and South Asian population with impaired glucose regulation and screen‐detected Type 2 diabetes mellitus: a comparison of two screening tools
Authors: Aujla N. , Skinner T. C. , Khunti K. , Davies M. J.
Published: May 2010

Diabet. Med. 27, 896–905 (2010)

Aims  To compare the identification of prevalent depressive symptoms by the World Health Organization‐5 Wellbeing Index (WHO‐5) and Centre for Epidemiological Studies Depression Scale (CES‐D) for South Asian and white European people, male and female, attending a diabetes screening programme, and to explore the adequacy of the screening tools for this population. An additional aim was to further explore associations of depressive symptoms with impaired glucose regulation (IGR) and Type 2 diabetes mellitus (Type2 DM).

Methods  Eight hundred and sixty‐four white European (40–75 years old) and 290 South Asian people (25–75 years old) underwent an oral glucose tolerance test (OGTT), detailed history and anthropometric measurements and completed the WHO‐5 and CES‐D. Depressive symptoms were defined by a WHO‐5 score ≤ 13, and CES‐D score ≥ 16.

Results  Unadjusted prevalence of depressive symptoms with the WHO‐5, for people with Type2 DM was 42.3% (47.4% in white European; 28.6% in South Asian) and for IGR 30.7% (26% in white European; 45.8% in South Asian). With the CES‐D, the prevalence in Type2 DM was 27.2% (25.4% in white European; 31.8% in South Asian) and for IGR 30.7% (27.8% in white European; 40.7% in South Asian). Statistically significant differences in the prevalence of depressive symptoms for sex or ethnicity were not identified. Odds ratios adjusted for age, sex and ethnicity showed no significant association of depression with Type2 DM or IGR, with either WHO‐5 or CES‐D. Agreement was moderate (κ = 0.48, 95% confidence intervals 0.42–0.54), and reduced when identifying depressive symptoms in people with Type2 DM. For this group, a WHO‐5 cut‐point of ≤ 10 was optimal.

Conclusions  Depressive symptoms, identified by WHO‐5 or CES‐D, were not significantly more prevalent in people with Type2 DM or IGR. The WHO‐5 and CES‐D differed in their identification of depressive symptoms in people with Type2 DM, though discrepancies between sex and ethnicity were not identified.
The Conservationist Mode of Production and Conservation NGOs in sub‐Saharan Africa
Authors: Brockington Dan , Scholfield Katherine
Published: May 2010

Abstract:  The work of conservation non‐governmental organizations (NGOs) is vital to the conservation movement and has attracted a good deal of comment and observation. Here we combine recent writings about the interactions of conservation and capitalism, and particularly the idea of “the conservationist mode” of production to explore the roles of conservation NGOs with respect to capitalism. We use an analysis of the conservation NGO sector in sub‐Saharan Africa to examine the ways in which conservation NGOs are integral to the spread of certain forms of capitalism, and certain forms of conservation, on the continent. We examine their mediating role in mediating and legitimizing knowledge, in effect forging and reproducing desires for particular visions and versions of Africa, and in producing and promoting new commodities which meet these needs, all of which facilitates capitalism's growth. Finally we consider a number of limitations to the activities of NGOs, and on the nature of the research we have undertaken, which may help to place their work in context.
Disconnected Nature: The Scaling Up of African Wildlife Foundation and its Impacts on Biodiversity Conservation and Local Livelihoods
Authors: Sachedina Hassanali T.
Published: May 2010

Abstract:  Much has been written about the resource crisis facing the conservation movement if it is to scale up successfully to face what are perceived as global threats such as biodiversity loss, poverty and climate change. But what happens to conservation organizations when they successfully scale up, and what are the impacts on biodiversity and local people? This paper attempts to chart the successful scaling up of an international conservation NGO, the African Wildlife Foundation, and examines the implications of this on its performance in community‐based wildlife conservation in Tanzania.
Cashing in on Cetourism: A Critical Ecological Engagement with Dominant E‐NGO Discourses on Whaling, Cetacean Conservation, and Whale Watching1
Authors: Neves Katja
Published: May 2010

Abstract:  This paper engages critically with the monolithic presentation of whale watching as the antithesis of whale hunting. It begins by tackling the reductive and homogenized portrayal of whale watching in mainstream environmental discourse as diametrically opposite to whale hunting and argues that such discourse likely obscures the existence of bad whale watching conduct. Next it reveals significant continuities between whale hunting and whale watching, especially the fetishized commoditization of cetaceans and the creation of a metabolic rift in human–cetacean relations. In both contexts nature is produced first and foremost according to capitalist principles, which problematizes the pervasive assumption that whale watching correlates primarily and directly with conservation. Finally, the paper examines two different business models and the production of distinct ecological and community development effects. The results of the comparison justify the need for more critical and effective environmental non‐governmental organization approaches to cetourism vis‐à‐vis nature conservation goals.
Kibale Forest Wild Coffee: Challenges to Market‐Based Conservation in Africa
Authors: LILIEHOLM ROBERT J. , WEATHERLY W. PAUL
Published: May 2010

Abstract:  Declining rural security and pressures to reduce public‐sector expenditures in the late 1990s spurred efforts to develop alternative funding models for Uganda's Kibale National Park (KNP). The Wild Coffee Project, established in 1999 with support from the U.S. Agency for International Development, the World Bank, and the Ford Foundation, sought to develop a market for wild coffee that had been harvested traditionally from areas within today's KNP. The Kibale Forest Foundation, a U.S.‐based nonprofit organization, was created to legalize harvests, obtain third‐party wild and organic certification, and coordinate management between KNP, the coffee industry, and local communities. Although the project was successful in legalizing, harvesting, and processing the world's first certified wild and organic coffee, efforts to gain entry into the international marketplace failed. Chief among the lessons learned from this project is that for many wild‐grown products, the value of “the story”—in both human and conservation terms—is likely to far exceed actual product values. This value differential should be captured through high‐value niche markets to avoid low commodity pricing and subsequent pressures to improve financial returns through over harvesting. In addition, local producers should hold significant assets in whatever brands are developed, creating a shared‐equity approach that serves social responsibility goals, fosters project sustainability, and ensures a steady stream of positive stories for use in marketing to build brand value. Shared equity—in this case ownership interest in the intellectual property embodied in the brand—provides a second incentive beyond transactional profits that can only be realized if resource conservation is maintained.
Hierarchical Bayesian Spatial Models for Multispecies Conservation Planning and Monitoring
Authors: CARROLL CARLOS , JOHNSON DEVIN S. , DUNK JEFFREY R. , ZIELINSKI WILLIAM J.
Published: May 2010

Abstract:  Biologists who develop and apply habitat models are often familiar with the statistical challenges posed by their data's spatial structure but are unsure of whether the use of complex spatial models will increase the utility of model results in planning. We compared the relative performance of nonspatial and hierarchical Bayesian spatial models for three vertebrate and invertebrate taxa of conservation concern (Church's sideband snails [Monadenia churchi], red tree voles [Arborimus longicaudus], and Pacific fishers [Martes pennanti pacifica]) that provide examples of a range of distributional extents and dispersal abilities. We used presence–absence data derived from regional monitoring programs to develop models with both landscape and site‐level environmental covariates. We used Markov chain Monte Carlo algorithms and a conditional autoregressive or intrinsic conditional autoregressive model framework to fit spatial models. The fit of Bayesian spatial models was between 35 and 55% better than the fit of nonspatial analogue models. Bayesian spatial models outperformed analogous models developed with maximum entropy (Maxent) methods. Although the best spatial and nonspatial models included similar environmental variables, spatial models provided estimates of residual spatial effects that suggested how ecological processes might structure distribution patterns. Spatial models built from presence–absence data improved fit most for localized endemic species with ranges constrained by poorly known biogeographic factors and for widely distributed species suspected to be strongly affected by unmeasured environmental variables or population processes. By treating spatial effects as a variable of interest rather than a nuisance, hierarchical Bayesian spatial models, especially when they are based on a common broad‐scale spatial lattice (here the national Forest Inventory and Analysis grid of 24 km2 hexagons), can increase the relevance of habitat models to multispecies conservation planning.
Molecular Divergence Defines Two Distinct Lineages of Crithidia bombi (Trypanosomatidae), Parasites of Bumblebees
Authors: SCHMID‐HEMPEL REGULA , TOGNAZZO MARTINA
Published: May 2010

ABSTRACT. This study provides, for the first time, sequence data for the protozoan flagellates Crithidia bombi and Crithidia mellificae (Kinetoplastea: Trypanosomatidae). We amplified the partial sequences of the small subunit ribosomal RNA (SSU rRNA), glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH), cytochrome b (Cyt b), and the complete internal transcribed spacer region 1 (ITS1) of the ribosomal RNA gene region for 66 clones of C. bombi from Switzerland and Alaska. Furthermore, we sequenced the same stretch of SSU rRNA and gGAPDH for one isolate of C. mellificae from Switzerland. All four molecular markers classified the C. bombi samples into two distinct lineages A and B. Both lineages were found in the two sampling locations. Variation within lineages was small or non‐existing. Sequence differences between lineages were 1.64% for SSU rRNA, 4.36% for gGAPDH, and 12.02% for Cyt b. The ITS1‐sequences of lineages A and B have diverged so much that no alignment was possible. With regard to ITS1, we additionally found fragment length polymorphism (variation in microsatellite repeat numbers) as well as nucleotide diversity within each lineage. Furthermore, the sequences of SSU rRNA and gGAPDH of C. mellificae were different from both lineages of C. bombi. The separation of lineages A and B, based on sequence differences and phylogenetic reconstruction, is so pronounced as to characterize two species of “C. bombi.” We propose to retain C. bombi for the more common lineage A and suggest the name Crithidia expoeki n. sp. for lineage B.
Could different environmental conditions select for different flight characteristics in sexual and asexual parasitoid Venturia canescens?
Authors: Lukáš Jan , Bernstein Carlos , Gu Hainan , Dorn Silvia
Published: May 2010

In the parasitoid Venturia canescens Gravenhorst (Hymenoptera: Ichneumonidae), asexual and sexual wasps coexist in the field in the Mediterranean basin, but only the asexual strain is present indoors. The sexual strain dominates outdoors despite the demographic costs associated with the production of males and mate location. The present study tests whether females of the sexual and asexual strains of V. canescens differ in flight characteristics in line with the differences of their preferred habitats and enquires whether these differences might contribute to the persistence of sexually reproducing individuals in the vicinity of asexual counterparts. The results show that sexual female wasps are smaller than their asexual counterparts. The size of wasps has a strong influence on flight parameters, with larger animals generally being better fliers. In wasps of approximately the same size, sexual wasps fly faster than their asexual counterparts under experimental laboratory conditions, in terms of both the average speed over the observation period as well as the longest single flight. Sexual wasps also perform fewer flights to cover the same distance. Sexual wasps have higher wing loading than asexual ones of the same size, which could have contributed to the observed differences in speed between individuals of both reproductive modes. There are no significant differences between the two reproductive modes in the parameters related to the distance traversed or the time spent in flight. This study shows clear differences in the flight behaviour of sexual and asexual V. canescens. Together with previous results, this finding suggests differential adaptations to their preferred habitats. These differences might ease the competition between modes of reproduction through niche and habitat differentiation and might help to explain their coexistence on a geographical scale.
Exploring Parents' Self‐Blame in Relation to Adolescents' Mental Disorders
Authors: Moses Tally
Published: May 2010

This study examined whether parents of adolescents diagnosed with mental disorders self‐blame for their child's disorders; their reasons for self‐blame; and the relationships between parental self‐blame and lower psychological well‐being, perceived stigmatization, social support, potential hereditary factors related to adolescents' mental disorders, demographics, and youths' clinical characteristics. Analysis of qualitative and quantitative interview data was used to classify 68 parents as “more” or “less” (40%) inclined to self‐blame. The most common reasons for parental self‐blame included perceived (a) bad parenting, (b) ineffective oversight of child's mental health status, (c) passing on “bad genes,” and (d) negative family environment. Greater parental self‐blame was related to parents' lower psychological well‐being and associated with potential hereditary transmission, family support, and adolescents' clinical characteristics.
Personal Care Services Utilization by Individuals With Developmental Disabilities
Authors: Harrington Charlene , Kang Taewoon
Published: May 2010

This study examined factors associated with the use of personal care services (PCS) and the amount of authorized hours in California in 2004–2005. Of those Medicaid‐eligible individuals with developmental disabilities living at home, 31% received PCS. When we controlled for client need, gender, and age, individuals who were Asian/Pacific Islanders, African Americans, Hispanics, and other races had higher odds of receiving PCS than Whites but were authorized between 16 and 39 hours fewer than Whites.
The Domestication of Health Care: Health Advice to Canadian Mothers 1993–2008 in Today's Parent
Authors: Clarke Juanne N.
Published: May 2010

The purpose of this article was to describe and analyze the ways that parents' and children's health are portrayed in health advice to parents in Canada's major mass print media magazine entitled Today's Parent, from 1993 to 2008. The qualitative content analysis noted three significant themes, including: most health issues are easily managed by mothers using common sense at home; mothers are responsible, healthy, energetic, and capable managers and experts who are able to work and advocate for their children's health; and mothers are able to critically assess doctors and medical care. Finally, anomalous stories are highlighted and some of the underlying assumptions of the stories are discussed. The substantive and practical consequences of these findings regarding parental health beliefs and actions are discussed.
Low‐Income Parental Profiles of Coping, Resource Adequacy, and Public Assistance Receipt: Links to Parenting
Authors: Maupin Angela N. , Brophy‐Herb Holly E. , Schiffman Rachel F. , Bocknek Erika L.
Published: May 2010

Variation in perceptions of resources and in coping strategies among low‐income parents likely influences parenting. The purposes of this study were to identify differences in parental profiles, as indicated by receipt of public assistance, perceptions of adequacy of resources, and coping strategies, and to examine these profiles relative to parenting. Results showed that perceptions of resource adequacy and coping strategies best differentiated parental profiles, whereas use of constructive coping strategies predicted cognitive stimulating parenting.
Stress, Communication, and Marital Quality in Couples
Authors: Ledermann Thomas , Bodenmann Guy , Rudaz Myriam , Bradbury Thomas N.
Published: May 2010

The association between daily stress outside and inside of the relationship and marital functioning in the form of communication in conflict situations and marital quality was examined. We hypothesized that relationship stress mediates the association between external stress and marital functioning at the individual level, and that the association between relationship stress and marital quality is partially mediated by communication at the dyadic level. Using the Actor‐Partner Interdependence and Common Fate Model, the results of 345 couples supported our hypotheses and revealed that a person's relationship stress is more strongly related with one's own external stress than with the partner's external stress. The findings indicate that both low relationship stress and a high level of positive communication are important in relationships.
Choosing Effective Youth‐Focused Prevention Strategies: A Practical Guide for Applied Family Professionals
Authors: Olson Jonathan R.
Published: May 2010

Advances in the field of prevention science have resulted in strategies that target various youth outcomes. In recent years, numerous “best practices” lists have been developed to help professionals identify such strategies. Some scholars have questioned the quality of these lists and cautioned that there are flaws in evaluations of many prevention strategies. The purpose of this paper is to review these criticisms and provide applied family scholars with suggestions regarding how to identify effective strategies.
Observations on the sexual system and the natural history of the semi‐terrestrial shrimp Merguia rhizophorae (Rathbun, 1900)
Authors: Baeza J. Antonio
Published: May 2010

Abstract. The sexual system of the semi‐terrestrial shrimp Merguia rhizophorae is described, along with natural history observations on this unusual caridean. Individuals of M. rhizophorae in the Bocas del Toro Archipelago, Panama, were found occupying fossilized coral terraces in the upper and mid‐intertidal zones, inhabiting caves and crevices, in and out of water. These fossilized coral terraces represent a new habitat for this species, which was previously reported only from mangrove swamps. Males, which made up 65% of the studied population, were smaller than females on average. No small juvenile females were observed, but transitional individuals having the characteristics of both males (gonopores) and females (ovaries) were observed in the population. These data suggest that individuals of M. rhizophorae are protandric hermaphrodites. Logistic regression indicated that the carapace length at which 50% of the individuals change sex is 4.89 mm. The abundance of shrimps at the study site was low. Shrimps were usually solitary, but occasionally observed in groups of ≤5 individuals. Shrimps were commonly observed walking while out of water, and in some cases, emerged shrimps jumped vigorously, presumably to avoid capture by the researcher or by predatory crabs. Additional studies on the reproductive biology and the behavioral ecology of members of this genus and of members of the closely related families Barbouridae and Lysmatidae will aid in understanding the evolutionary origin and the adaptive value of gender expression patterns in shrimps.
Iodide/Iodate Chemical Actinometry Using Spherical Vessels for Radiation Exposure as well as for Monitoring Absorbance Changes
Authors: Rahn Ronald O. , Echols Stanley
Published: May 2010

Spherical quartz vessels containing an iodide/iodate chemical actinometer are useful for measuring the fluence of omnidirectional germicidal radiation. It is shown here that such vessels can be used not only for exposure purposes but also for measuring the absorbance of the resulting triiodide endpoint. A hand‐held commercially available colorimeter using a 420 nm LED light source was adapted to hold the spheres in the optical light path. The absorbance at 420 nm obeyed Beer’s Law and the dose response showed linear kinetics following irradiation at 254 nm. The determination of the fluence obtained in this manner was consistent with that obtained following transfer of the contents of the spheres to a 1 cm cuvette and measuring the absorbance at 352 nm in a conventional spectrophotometer. Hence, dose response data can be obtained making absorbance measurements on the same sample following sequential or continuous irradiation. Furthermore, because the expression for the fluence is independent of the radius of the sphere, there is no need to measure and keep track of the volume of each sphere, thus simplifying the experimental procedure. Furthermore, the use of an inexpensive colorimeter circumvents the need for a more expensive spectrophotometer and allows measurements to be made in the field.
Fiber‐optic Singlet Oxygen [1O2 (1Δg)] Generator Device Serving as a Point Selective Sterilizer
Authors: Aebisher David , Zamadar Matibur , Mahendran Adaickapillai , Ghosh Goutam , McEntee Catherine , Greer Alexander
Published: May 2010

Traditionally, Type II heterogeneous photo‐oxidations produce singlet oxygen via external irradiation of a sensitizer and external supply of ground‐state oxygen. A potential improvement is reported here. A hollow‐core fiber‐optic device was developed with an “internal” supply of light and flowing oxygen, and a porous photosensitizer‐end capped configuration. Singlet oxygen was delivered through the fiber tip. The singlet oxygen steady‐state concentration in the immediate vicinity of the probe tip was ca 20 fm by N‐benzoyl‐dl‐methionine trapping. The device is portable and the singlet oxygen‐generating tip is maneuverable, which opened the door to simple disinfectant studies. Complete Escherichia coli inactivation was observed in 2 h when the singlet oxygen sensitizing probe tip was immersed in 0.1 mL aqueous samples of 0.1–4.4 × 107 cells. Photobleaching of the probe tip occurred after ca 12 h of use, requiring baking and sensitizer reloading steps for reuse.
In Vivo Effects on Photosynthesis Gene Expression of Base Pair Exchanges in the Gene Encoding the Light‐responsive BLUF Domain of AppA in Rhodobacter Sphaeroides
Authors: Metz Sebastian , Hendriks Johnny , Jäger Andreas , Hellingwerf Klaas , Klug Gabriele
Published: May 2010

The Rhodobacter sphaeroides protein AppA has the unique quality of sensing and transmitting light and redox signals. By acting as antirepressor to the PpsR protein, it acts as a major regulator in photosynthesis gene expression. In this study, we show that by introducing amino acid exchanges into the AppA protein, the in vivo activity as an antirepressor can be greatly altered. The tryptophan 104 to phenylalanine (W104F) base exchange greatly diminished blue‐light sensitivity of the BLUF domain. From the obtained in vivo data, the difference in thermal recovery rate of the signaling state of the BLUF domain between the wild type and mutated protein was calculated, predicting an about 10‐fold faster recovery in the mutant, which is consistent with in vitro data. Introduction of a tyrosine 21 to phenylalanine (Y21F) or to cysteine (Y21C) mutation led to a complete loss of AppA antirepressor activity, while additionally leading to an increase of photosynthesis gene expression after illumination with high blue‐light quantities. Interestingly, this effect is not visible in a W104F/Y21F double mutant that again shows a wild‐type–like behavior of the BLUF domain after blue‐light illumination, thus restoring the activity of AppA.
Colic in geriatric compared to mature nongeriatric horses. Part 2: Treatment, diagnosis and short‐term survival
Authors: SOUTHWOOD L. L. , GASSERT T. , LINDBORG S.
Published: May 2010

Reason for performing study:Owners and veterinarians are often concerned about mortality of geriatric horses following colic surgery.

Objective:To compare treatment, diagnosis and short‐term survival for geriatric compared to mature nongeriatric horses with colic.

Methods:Medical records of horses admitted with a presenting complaint of colic between 2000 and 2006 were reviewed. Geriatric horses were aged ≥16 years (n = 300) and subcategorised as age ≥20 years (n = 134). Mature nongeriatric horses were age 4–15 years (n = 300). Information obtained included medical (included horses subjected to euthanasia without surgery) vs. surgical management, lesion location, type and classification, surgical procedures performed and short‐term survival. Data were analysed using a Chi‐squared test or an analysis of variance. Level of significance was P<0.05.

Results:The overall short‐term survival of geriatric horses was lower than that for mature horses (59 vs. 76%, respectively). The survival of medically managed geriatric horses was lower than that for mature horses (58 vs. 80%, respectively). The survival of surgically managed geriatric horses was not different to that for mature horses (59 vs. 70%, respectively) except for geriatric horses age ≥20 years (53%). There was no difference in survival between geriatric and mature horses with small (86 and 83%, respectively) or large (78 vs. 70%, respectively) intestinal strangulating lesions or those undergoing jejunojejunostomy (75 vs. 70%, respectively). Geriatric horses with a large colon simple obstruction had a lower survival compared to mature horses (80 vs. 97%, respectively).

Conclusions and potential relevance:The survival of geriatric horses with a strangulating lesion or requiring jejunojejunostomy was not different to that for mature horses. Geriatric horses presenting with colic were more likely than mature horses to be subjected to euthanasia without surgery (i.e. lower survival with medical treatment). Geriatric horses undergoing surgery for a large colon simple obstruction had a lower survival than mature horses.
Pathology of lethal peripartum broad ligament haematoma in 31 Thoroughbred mares
Authors: UENO T. , NAMBO Y. , TAJIMA Y. , UMEMURA T.
Published: May 2010

Reasons for performing study: Broad ligament haemorrhage in peripartum mares is a life‐threatening disease and there are few reports on the aetiology and pathogenesis of broad ligament haematoma.

Objectives: To obtain information regarding the sites for the early diagnosis and pathogenesis of broad ligament haematoma of mares.

Methods: Thirty‐one mares that died of broad ligament haematoma peripartum were examined pathologically for bleeding sites. The arterial distribution of 5 young mares with several parities served as negative controls.

Results: Age and/or multiparity were the predisposing factors for the disease. Arterial injuries were most commonly observed in the uterine artery (24 of 31 mares). Among these, the proximal uterine artery that lies within 15 cm of the bifurcation of the iliac artery was the most frequent site for rupture (18 mares). The lesions occurred preferentially at the bifurcations, lateral part of curvatures and abrupt flexures of the artery. The morphology of the injuries was classified into 3 types: ruptures with and without longitudinal fissures, and transections. Histologically, the arterial wall adjacent to the rupture showed atrophy of smooth muscle cells with fibrosis of the tunica media and disruption and/or calcification of the internal elastic lamina.

Conclusions: Arterial injuries that led to broad ligament haematoma in peripartum mares occurred most frequently in the proximal uterine artery, and atrophy of smooth muscle cells with fibrosis of the arterial wall was as one of the predisposing factors in aged and multiparous mares.

Potential relevance: Monitoring small aneurysms, mural tearing, medial fibrosis at the proximal uterine artery by transrectal echography could provide useful information for the early diagnosis and possible prevention of broad ligament haematoma of peripartum mares.
A computational model of Purkinje fibre single cell electrophysiology: implications for the long QT syndrome
Authors: Sampson K. J. , Iyer V. , Marks A. R. , Kass R. S.
Published: May 2010

Computer modelling has emerged as a particularly useful tool in understanding the physiology and pathophysiology of cardiac tissues. Models of ventricular, atrial and nodal tissue have evolved and include detailed ion channel kinetics and intercellular Ca2+ handling. Purkinje fibre cells play a central role in the electrophysiology of the heart and in the genesis of cardiac arrhythmias. In this study, a new computational model has been constructed that incorporates the major membrane currents that have been isolated in recent experiments using Purkinje fibre cells. The model, which integrates mathematical models of human ion channels based on detailed biophysical studies of their kinetic and voltage‐dependent properties, recapitulates distinct electrophysiological characteristics unique to Purkinje fibre cells compared to neighbouring ventricular myocytes. These characteristics include automaticity, hyperpolarized voltage range of the action potential plateau potential, and prolonged action potential duration. Simulations of selective ion channel blockade reproduce responses to pharmacological challenges characteristic of isolated Purkinje fibres in vitro, and importantly, the model predicts that Purkinje fibre cells are prone to severe arrhythmogenic activity in patients harbouring long QT syndrome 3 but much less so for other common forms of long QT. This new Purkinje cellular model can be a useful tool to study tissue‐specific drug interactions and the effects of disease‐related ion channel dysfunction on the cardiac conduction system.
Glycinergic and GABAergic tonic inhibition fine tune inhibitory control in regionally distinct subpopulations of dorsal horn neurons
Authors: Takazawa Tomonori , MacDermott Amy B.
Published: May 2010

Inhibition mediated by glycine and GABA in the spinal cord dorsal horn is essential for controlling sensitivity to painful stimuli. Loss of inhibition results in hyperalgesia, a sensitized response to a painful stimulus, and allodynia, a pain‐like response to an innocuous stimulus like touch. The latter is due, in part, to disinhibition of an excitatory polysynaptic pathway linking low threshold touch input to pain projection neurons. This critical impact of disinhibition raises the issue of what regulates the activity of inhibitory interneurons in the dorsal horn under non‐pathological conditions. We have found that inhibitory neurons throughout lamina I–III, identified by the GAD67 promoter‐driven EGFP, are tonically inhibited by glycine or GABA in a regionally distinct way that is mirrored by their inhibitory synaptic input. This tonic inhibition strongly modifies action potential firing properties. Surprisingly, we found that inhibitory neurons at the lamina II/III border are under tonic glycinergic control and receive synapses that are predominantly glycinergic. Futhermore, this tonic glycinergic inhibition remains strong as the mice mature postnatally. Interestingly, GlyT1, the glial glycine transporter, regulates the strength of tonic glycinergic inhibition of these glycine‐dominant neurons. The more dorsal lamina I and IIo inhibitory neurons are mainly under control by tonic GABA action and receive synapses that are predominantly GABAergic. Our work supports the hypothesis that tonic glycine inhibition controls the inhibitory circuitry deep in lamina II that is likely to be responsible for separating low threshold input from high threshold output neurons of lamina I.
Permeant anions contribute to voltage dependence of ClC‐2 chloride channel by interacting with the protopore gate
Authors: Sánchez‐Rodríguez Jorge E. , De Santiago‐Castillo José A. , Arreola Jorge
Published: May 2010

It has been shown that the voltage (Vm) dependence of ClC Cl− channels is conferred by interaction of the protopore gate with H+ ions. However, in this paper we present evidence which indicates that permeant Cl− ions contribute to Vm‐dependent gating of the broadly distributed ClC‐2 Cl− channel. The apparent open probability (PA) of ClC‐2 was enhanced either by changing the [Cl−]i from 10 to 200 mm or by keeping the [Cl−]i low (10 mm) and then raising [Cl−]o from 10 to 140 mm. Additionally, these changes in [Cl−] slowed down channel closing at positive Vm suggesting that high [Cl−] increased pore occupancy thus hindering closing of the protopore gate. The identity of the permeant anion was also important since the PA(Vm) curves were nearly identical with Cl− or Br− but shifted to negative voltages in the presence of SCN− ions. In addition, gating, closing rate and reversal potential displayed anomalous mole fraction behaviour in a SCN−/Cl− mixture in agreement with the idea that pore occupancy by different permeant anions modifies the Vm dependence ClC‐2 gating. Based on the ec1‐ClC anion pathway, we hypothesized that opening of the protopore gate is facilitated when Cl− ions dwell in the central binding site. In contrast, when Cl− ions dwell in the external binding site they prevent the gate from closing. Finally, this Cl−‐dependent gating in ClC‐2 channels is of physiological relevance since an increase in [Cl−]o enhances channel opening when the [Cl−]i is in the physiological range.
Neutron transmutation doping effects in GaN
Authors: Polyakov A. Y. , Smirnov N. B. , Govorkov A. V. , Kolin N. G. , Merkurisov D. I. , Boiko V. M. , Korulin A. V. , Pearton S. J.
Published: May 2010

The effects of neutron transmutation doping were studied for undoped (residual donor concentrations <1015 cm−3) GaN films grown by metalorganic chemical vapor deposition. After irradiation with reactor neutrons (equal fluences of 1.5×1017 n/cm2 of thermal and fast neutrons) the sample became semi-insulating, with the Fermi level pinned near Ec−0.8 eV. Isochronal annealing from 100 to 1000 °C showed three stages—slight recovery of conductivity at 200–300 °C, reverse annealing at 300–500 °C, and a broad recovery stage from 600 to 1000 °C. After annealing at 1000 °C, the donor concentration in the sample was close to the expected concentration of Ge donors transformed from Ga atoms upon interaction with thermal neutrons (2×1016 cm−3). Admittance spectroscopy showed that the donors had ionization energies ∼Ea=0.2 eV, much deeper than substitutional Ge donors. For intermediate annealing temperatures of 800 °C the donors were deeper (Ea=0.47 eV), but the proximity of concentrations of all these different centers suggests that they are due to transformation of complexes of Ge donors with radiation defects.
The Balance of WNT and FGF Signaling Influences Mesenchymal Stem Cell Fate During Skeletal Development
Authors: Maruyama Takamitsu , Mirando Anthony J. , Deng Chu-Xia , Hsu Wei
Published: May 2010

Imbalance of WNT and FGF signaling promotes premature closure of skull bones by inducing bone formation through chondrogenesis.
Uses the Force
Authors: Foley John F.
Published: May 2010

Coupling to antigen-presenting cells through the T cell receptor renders T cells sensitive to mechanical force.
Escaping the Dephosphorylation Zone
Authors: Adler Elizabeth M.
Published: May 2010

Generation of signals crucial to arterial morphogenesis depends on VEGFR2 trafficking mechanisms that limit its exposure to the phosphatase PTP1b.
All Together Now
Authors: Vinson Valda
Published: May 2010

Stochastic pulsing of individual cells plays a critical role in initiating cAMP pulses.
Budding Yeast Kinome Revealed
Authors: Ray L. Bryan
Published: May 2010

Phosphorylation reactions in budding yeast reveal the regulatory architecture of a fundamental cellular control system.
Controlling the Fate of NIK: A Central Stage in Noncanonical NF-κB Signaling
Authors: Sun Shao-Cong
Published: May 2010

A component of the IκB kinase complex mediates feedback inhibition of the kinase NIK.
Cell Wall Thickening Is Not a Universal Accompaniment of the Daptomycin Nonsusceptibility Phenotype in
Staphylococcus aureus
: Evidence for Multiple Resistance Mechanisms
Authors: Yang Soo-Jin , Nast Cynthia C. , Mishra Nagendra N. , Yeaman Michael R. , Fey Paul D. , Bayer Arnold S.
Published: May 2010

The mechanism(s) of daptomycin (DAP) resistance (DAP
r
) is incompletely defined. Thickened cell walls (CWs) acting as either a mechanical barrier or an affinity trap for DAP have been purported to be a major contributor to the DAP
r
phenotype. To this end, we studied an isogenic set of methicillin-resistant
Staphylococcus aureus
(MRSA) isolates (pulsotype USA 300) from the bloodstream of a DAP-treated patient with endocarditis in which serial strains exhibited increasing DAP
r
. Of interest, the DAP
r
isolate differed from its parental strain in several parameters, including acquisition of a point mutation within the putative synthase domain of the
mprF
gene in association with enhanced
mprF
expression, increased synthesis of lysyl-phosphotidylglycerol, an enhanced positive envelope charge, and reduced DAP surface binding. Transmission electron microscopy (TEM) revealed no significant increases in CW thickness in the two DAP
r
isolates (MRSA 11/21 and REF2145) compared with that in the DAP-susceptible (DAP
s
) parental strain, MRSA 11/11. The rates of Triton X-100-induced autolysis were also identical for the strain set. Furthermore, among six additional clinically isolated DAP
s
/DAP
r
S. aureus
strain pairs, only three DAP
r
isolates exhibited CWs significantly thicker than those of the respective DAP
s
parent. These data confirm that CW thickening is neither universal to DAP
r
S. aureus
nor sufficient to yield the DAP
r
phenotype among
S. aureus
strains.