bluuebunny/crossref_metadata_2025 huggingface dataset:
Toward a better understanding of the regional causes of local community richness
Authors: Harrison Susan , Cornell Howard
Published: May 2008

Despite widespread acknowledgement that local ecological communities are profoundly shaped by regional‐scale influences, including evolutionary and biogeographic processes, this perspective has yet to be widely incorporated into ecological research. Drawing on recent research, we propose four steps towards making regional influences a stronger part of research on the richness of local communities: (1) identifying the regional‐scale causes of variation in species richness in the systems ecologists study; (2) testing for effects of regional richness on local richness, using improved observational and experimental analyses to overcome earlier problems; (3) simultaneously analysing environmental influences on regional and local species richness as well as the influence of regional richness on local richness and (4) considering the potential reciprocal effects of local processes on regional richness. In conclusion, we suggest some ways that similar approaches could be applied to other aspects of community structure beyond species richness.
The social context of childcare practices and child malnutrition in Niger's recent food crisis
Authors: Hampshire Katherine , Casiday Rachel , Kilpatrick Kate , Panter‐Brick Catherine
Published: May 2008

In 2004–05, Niger suffered a food crisis during which global attention focused on high levels of acute malnutrition among children. In response, decentralised emergency nutrition programmes were introduced into much of southern Niger. Child malnutrition, however, is a chronic problem and its links with food production and household food security are complex. This qualitative, anthropological study investigates pathways by which children are rendered vulnerable in the context of a nutritional ‘emergency’. It focuses on household‐level decisions that determine resource allocation and childcare practices in order to explain why practices apparently detrimental to children's health persist. Risk aversion, the need to maintain self‐identity and status, and constrained decision making result in a failure to invest extra necessary resources ingrowth‐faltering children. Understanding and responding to the social context of child malnutrition will help humanitarian workers to integrate their efforts more effectively with longer‐term development programmes aimed at improving livelihood security.
Necessity and Language: The Gap Is Still Very Real
Authors: Kalhat Javier
Published: May 2008

In my previous paper “Has the later Wittgenstein accounted for necessity?” I argued against the conventionalist account of necessity proposed by Wittgenstein and his followers. Glock has addressed some of my objections in his paper “Necessity and Language: In Defence of Conventionalism”. This brief rejoinder considers Glock's replies to three of those objections. In the course of doing so, I revisit Wittgenstein's explanation of the special status of necessary propositions, the supposedly arbitrary nature of colour‐grammatical propositions, and the relation between rules and modality.
Phillips and Eternal Life: A Response to Haldane
Authors: Burley Mikel
Published: May 2008

This paper responds to John Haldane's recent criticisms of D. Z. Phillips’ treatment of the Christian belief in eternal life. I argue that Haldane's attempt to show that Phillips only partially elucidates, and hence misrepresents, this belief is unsuccessful, the biblical and theological passages cited by Haldane being amenable to elucidation in terms of which Phillips would have approved. Haldane makes three points to support his main claim, and I argue that none of these has significant force against Phillips’ position unless we presuppose the truth of some realist account of meaning, which Phillips would, of course, reject.
EMBRYONIC ASSOCIATIONALISM: NEW LABOUR AND URBAN GOVERNANCE
Authors: BACHE IAN , CATNEY PHILIP
Published: May 2008

This article considers the role of ideas in New Labour’s approach to the governance of urban regeneration and characterizes this approach as ‘embryonic associationalism’. This approach contrasts with the economic rationalism of previous Conservative governments and leads to a more determined effort to empower local community groups within the policy process. We analyse the effects of this shift in approach in practice through a comparative case study of changing patterns of governance in different areas of the English city of Sheffield over a ten‐year period. We conclude that while other factors are important in shaping the nature of community empowerment, New Labour’s approach has promoted a political environment in which it is increasingly difficult for local state actors to ignore the voice of local communities. However, while we refer to this as ‘New Labour’s approach’, we are clear that this relates to a tradition of ideas that is far from new in Labour thought.
WHAT’S VALUED MOST? SIMILARITIES AND DIFFERENCES BETWEEN THE ORGANIZATIONAL VALUES OF THE PUBLIC AND PRIVATE SECTOR
Authors: VAN DER WAL ZEGER , DE GRAAF GJALT , LASTHUIZEN KARIN
Published: May 2008

In recent administrative and organizational literature much attention has been paid to values that guide organizational and managerial behaviour in the public and private domain. Comparative empirical research efforts, however, are sparse. This article reports the results of a comparative empirical survey of 382 managers from a variety of public and private sector organizations in The Netherlands. Contrary to much recent literature that presupposes the intermixing or convergence of value systems guiding governance in different kinds of organizations, the results of this study show two distinct and relatively classical value systems for government and business as well as a ‘common core’ of important organizational qualities. These are accountability, expertise, reliability, efficiency and effectiveness, all of which are considered crucial in both public and private sector organizations. Additional analysis shows that value preferences are primarily attached to sector rather than to age, gender, working experience, or previous employment in the other sector.
IDENTIFYING CAUSALITY IN PUBLIC INSTITUTIONAL CHANGE: THE ADAPTATION OF THE NATIONAL ASSEMBLY FOR WALES TO THE EUROPEAN UNION
Authors: CARTER CAITRÍONA A.
Published: May 2008

The aim of this article is to identify causes and effects of public institutional change. Analysis is centred on those endogenous, not exogenous, sources of political change that account for the institutional metamorphosis of the Welsh Assembly in its engagement with UK‐EU processes since 1999. The central research question addressed is to explain a qualitative shift in the logic of action of Assembly engagement, resulting in the conduct of a territorially sensitive ‘parliamentary’ EU scrutiny, but within a model of executive devolution. To capture agency and change, and to engage with sociological institutionalist debates, the article develops analytical tools of ‘framing’ and ‘operationalizing’ institutions to study the interplay between informal and formal processes of institution building since devolution. In so doing, we place refined sociological conceptions of institutions at the heart of analyses of political discontinuity and theorization of public institutional change.
PUBLIC SECTOR INNOVATION FOR EUROPE: A MULTINATIONAL EIGHT‐COUNTRY EXPLORATION OF CITIZENS’ PERSPECTIVES
Authors: VIGODA‐GADOT ERAN , SHOHAM AVIV , SCHWABSKY NITZA , RUVIO AYALLA
Published: May 2008

This study presents a three‐year effort to study public sector innovation in Europe from the viewpoint of the citizen. It examines a model of public sector innovation across a multinational sample of eight countries and 626 participants. The paper develops a theory of antecedents to and consequences of innovation in public administration as perceived by knowledgeable citizens and end‐users. Participants were senior and mid‐level managers of third sector organizations that work closely with citizens both as individuals and groups, and with public sector agencies in various domains. Structural Equation Modeling technique was used to examine two theoretical and five alternative models. Major findings that transcend national borders were found to be: (1) responsiveness, together with leadership and vision are important antecedents of innovation in the public sector; (2) public sector innovation affects trust in and satisfaction with public administration; and (3) the effect of public sector innovation on trust and satisfaction is both direct and mediated by the image of public organizations. The paper ends with a discussion of the theoretical and practical implications for public administration theory, especially for public sector innovation in Europe, and with directions for future studies.
Reduced MHC variation in a threatened tuatara species
Authors: Miller H. C. , Miller K. A. , Daugherty C. H.
Published: May 2008

The relationship between neutral and adaptive genetic diversity is important to understand in assessing the implications of a population bottleneck. Fitness‐related genes, such as those of the major histocompatibility complex (MHC), may be influenced by selection, and so retain diversity even when it is lost at neutral markers. We measured MHC class I variation in an archaic reptile species Sphenodon guntheri [North Brother Island (NBI) tuatara], which naturally occurs on one 4 ha island in Cook Strait, New Zealand, and has low levels of microsatellite diversity. MHC variation in S. guntheri was compared with microsatellite DNA variation, and with MHC variation in a large population of Sphenodon punctatus (Cook Strait tuatara) on Stephens Island. The NBI population shows significantly decreased levels of genetic diversity compared with the Stephens Island population. Only three different MHC sequences and three genotypes were found on NBI, compared with 15 sequences and 21 genotypes in a similar sample size from Stephens Island. Two sequences appear to be unique to the NBI population. The assortment of sequence variants into genotypes suggests strong gametic disequilibrium between two MHC class I loci in S. guntheri, and only two haplotypes that were present in Hardy–Weinberg proportions were identified. MHC diversity in NBI tuatara appears to be largely influenced by genetic drift, consistent with a recent population bottleneck. This may compromise the ability of this population to respond to novel disease threats.
Using Population Mixtures to Optimize the Utility of Genomic Databases: Linkage Disequilibrium and Association Study Design in India
Authors: Pemberton T. J. , Jakobsson M. , Conrad D. F. , Coop G. , Wall J. D. , Pritchard J. K. , Patel P. I. , Rosenberg N. A.
Published: May 2008

When performing association studies in populations that have not been the focus of large‐scale investigations of haplotype variation, it is often helpful to rely on genomic databases in other populations for study design and analysis – such as in the selection of tag SNPs and in the imputation of missing genotypes. One way of improving the use of these databases is to rely on a mixture of database samples that is similar to the population of interest, rather than using the single most similar database sample. We demonstrate the effectiveness of the mixture approach in the application of African, European, and East Asian HapMap samples for tag SNP selection in populations from India, a genetically intermediate region underrepresented in genomic studies of haplotype variation.
A simple morphological predictor of bite force in rodents
Authors: Freeman P. W. , Lemen C. A.
Published: May 2008

Bite force was quantified for 13 species of North American rodents using a piezo‐resistive sensor. Most of the species measured (11) formed a tight relationship between body mass and bite force (log 10(bite force)=0.43(log 10(body mass))+0.416; R2>0.98). This high correlation exists despite the ecological (omnivores, grazers and more carnivorous) and taxonomic (Cricetidae, Heteromyidae, Sciuridae and Zapodidae) diversity of species. Two additional species, Geomys bursarius (Geomyidae) and a Sciurus niger (Sciuridae), bit much harder for their size. We found a simple index of strength based on two measurements of the incisor at the level of the alveolus (Zi=((anterior‐posterior length)2× (medial‐lateral width))/6) that is highly predictive of bite force in these rodents (R2>0.96). Zi may be useful for prediction of bite force (log10 (Bite Force)=0.566log10 (Zi)+1.432) when direct measurements are not available.
The feedback correct‐related positivity: Sensitivity of the event‐related brain potential to unexpected positive feedback
Authors: Holroyd Clay B. , Pakzad‐Vaezi Kaivon L. , Krigolson Olave E.
Published: May 2008

The N200 and the feedback error‐related negativity (fERN) are two components of the event‐related brain potential (ERP) that share similar scalp distributions, time courses, morphologies, and functional dependencies, which raises the question as to whether they are actually the same phenomenon. To investigate this issue, we recorded the ERP from participants engaged in two tasks that independently elicited the N200 and fERN. Our results indicate that they are, in fact, the same ERP component and further suggest that positive feedback elicits a positive‐going deflection in the time range of the fERN. Taken together, these results indicate that negative feedback elicits a common N200 and that modulation of fERN amplitude results from the superposition on correct trials of a positive‐going deflection that we term the feedback correct‐related positivity.
Reconfiguring ‘post‐socialist’ regions: cross‐border networks and regional competition in the Slovak and Ukrainian clothing industry
Authors: SMITH ADRIAN , PICKLES JOHN , BUČEK MILAN , BEGG ROBERT , ROUKOVA POLI
Published: May 2008

The global garment industry is currently being reshaped in dramatic ways through processes of trade liberalization, delocalization and interfirm and interregional competition. There has been much speculation about the increasing importance of factor (especially labour) costs in fuelling further rounds of de‐localization of garment production towards low‐cost production locations, such as China and India. However, the extent to which these processes mean the end to garment production in higher factor‐cost locations, including those neighbouring the major clothing markets of the USA and the EU, is open to question. In this article we interrogate the interregional shifts in garment sourcing taking place in Europe and its surrounding regions. While factor costs (including labour) are important determinants of the geography of sourcing, a range of other costs (logistical and policy costs) are important in structuring the geographies of global and regional production. Firms in the Slovak Republic are responding to increasing competitive pressures and we assess how trans‐border sourcing, subcontracting and FDI are being integrated into strategies to sustain European production networks. We highlight the emergence of cross‐border production relocation to Ukraine as one specific strategy. We examine the product specificity of these changes and the ways in which they are embedded within already existing production networks, forms of cross‐border contracting and central European trade regimes. In other words, we explore some of the forces that shape the somewhat tentative continuation of garment production for export to EU markets in central Europe despite the ‘spectre of China’.
Ethical Issues in Dialysis Aaron Spital, Series Editor: Palliative Care: Misconceptions That Limit Access for Patients with Chronic Renal Disease
Authors: Jablonski Anita
Published: May 2008

There is an urgent need to incorporate palliative care into the treatment of patients with end‐stage renal disease (ESRD). These patients have a shortened lifespan and face end‐of‐life decisions as renal function declines and renal replacement therapy becomes necessary. They also experience a high symptom burden as a result of the illness as well as its treatment. Why, then, do patients with ESRD rarely receive expert palliative care services that have been shown to enhance the quality of life of patients with other life‐limiting illnesses? The lack of access to palliative care can be attributed, in part, to misconceptions about its philosophy and goals. It is hoped that clarification of these misconceptions will facilitate integration of palliative care into routine nephrology practice.
A Challenge for Nephrologists—Increasing Fistula Maturation Rates, Reducing Fistula Maturation Time, and Decreasing Dialysis Catheter Prevalence in the United States
Authors: Levine Michael I.
Published: May 2008

Tunneled dialysis catheters are simultaneously a benefit and burden for hemodialysis patients. The infectious and vascular complications of catheters are well documented. Despite this, prevalence of catheter use in the US hemodialysis population remains high and could be due in part to increased efforts to create arteriovenous (AV) fistulas in most new end‐stage renal disease patients. The editorial argues that creating fistulas instead of prosthetic grafts is the correct approach and that inadequately diagnosed and treated primary fistula failure is a major cause of excessive and prolonged catheter dependency. An understanding of AV fistula physiology and the treatable causes of primary fistula failure are key to maximizing the percentage of created fistulas that are successfully used for dialysis. Diagnosis of fistula malfunction based on history, physical examination, and hemodynamic and angiographic evaluation is discussed, and treatment strategies presented. A major emphasis is placed on early primary fistula failure recognition and intervention. It is the author’s contention if adequate vein and artery are selected for initial fistula construction nearly all fistulas should eventually function adequately to support dialysis and sooner than previously appreciated by utilizing an array of percutaneous and surgical therapies. Fistula malfunction is a unique problem within the spectrum of vascular disease and therefore demands that patients are treated by physicians with demonstrated expertise and experience.
Retrospective Analysis of Catheter Recirculation in Prevalent Dialysis Patients
Authors: Moossavi Shahab , Vachharajani Tushar J. , Jordan Jean , Russell Gregory B. , Kaufman Tina , Moossavi Shahriar
Published: May 2008

Catheter recirculation (CR) occurs when blood returning from the venous limb of the catheter re‐enters the arterial limb of the catheter without passage through the circulation. Adequacy of dialysis is influenced by the degree of access recirculation. In this study we evaluate factors influencing the degree of dialysis central venous catheter (CVC) recirculation in prevalent hemodialysis patients. This is a retrospective study of all patients undergoing hemodialysis via a catheter at the Wake Forest University Outpatient Dialysis Facilities from September 1, 2006 to May 15, 2007. CR was correlated to catheter type, catheter brand, site of placement, catheter length, time on dialysis, time on the current catheter, and was measured via ultrasound dilution technique. A total of 165 catheters were identified. Seventy‐one catheters were in the right internal jugular position, 43 in the left internal jugular position, 13 in the right subclavian, one in the left subclavian, eight in the right femoral, two in the left femoral, and four in the trans‐lumber position. CR was 6.3 ± 7.5% in symmetric tip catheters (n = 14), 6.0 ± 8.3% in split‐tip catheters (n = 102), 8.4 ± 11.7% in step‐tip catheters (n = 10), and 23.0 ± 8.2% in temporary catheters (n = 3), respectively. These results are borderline significant if temporary catheters are included (p = 0.052); however, the overall p‐value is only 0.80 for tunneled dialysis catheters. There was no correlation between CR and time on dialysis (p = 0.66) or time on the current catheter (p = 0.48). The current study suggests that the CVC recirculation is independent of catheter brand, type, time on dialysis, or time on current catheter.
Selecting an Appropriate Medication for Treating Neuropathic Pain in Patients with Diabetes: A Study Using the U.K. and Germany Mediplus Databases
Authors: Gore Mugdha , Sadosky Alesia , Leslie Douglas , Sheehan Amy Heck
Published: May 2008

▪ Abstract

Objective:  To evaluate the appropriateness of prescribing select neuropathic pain medications to diabetes patients based on the potential for drug–drug interactions with medications diabetes patients were prescribed continuously for ≥ 3 months (chronic use).

Methods:  Medical records of patients with a diagnosis of diabetes or use of antidiabetic medications between January 1, 2002 and September 30, 2005 in the U.K. and Germany Mediplus databases were obtained.

Patients:  Medication use profiles were evaluated between April 2004 and September 2005. The metabolic pathways associated with medications that were prescribed chronically to at least 10% of study patients were compared with the metabolic pathways of neuropathic pain medications to identify potential drug–drug interactions.

Results:  A total of 40,448 patients in the U.K. (63.6 ± 16.6 years, 51% male) and 31,930 patients in Germany (68.9 ± 12.7 years, 46% male) were identified. Frequently prescribed medications in the U.K. included aspirin (33.7%), metformin (32.7%), simvastatin (25.5%), atorvastatin (19.4%), atenolol (18.1%), and in Germany hydrochlorothiazide (35.8%), aspirin (25.2%), metformin (21.6%), metoprolol (20.3%), and simvastatin (18.3%). Several neuropathic pain medications have potential for drug–drug interactions with medications prescribed to diabetes patients. Examples include (neuropathic pain medications vs. diabetes medications): duloxetine, paroxetine, and methadone (CYP2D6 inhibitors) and oxycodone HCL, hydrocodone (CYP2D6 substrates) vs. metoprolol and bisoprolol (CYP2D6 substrates); and carbamazepine (CYP3A4 inducer) vs. simvastatin, and atorvastatin (CYP3A4 substrates).

Conclusions/Interpretation:  Our findings underscore the need for medical vigilance when selecting medications for treating neuropathic pain in diabetes patients. ▪
Effect of partial recording protocols on severity estimates of periodontal disease
Authors: Kingman Albert , Susin Cristiano , Albandar Jasim M.
Published: May 2008

Objectives: The study aim was to assess bias magnitudes of periodontal disease severity estimates for specific partial recording protocols (PRPs) in epidemiological studies.

Material and Methods: Estimates of mean clinical attachment loss (MCAL) and mean probing pocket depth (MPPD) were derived for 20 different PRPs using full‐mouth periodontal data from 1437 dentate Brazilian subjects 14–103 years old having at least four teeth. Biases, relative biases and intra‐class correlations for all PRPs were evaluated. Graphical methods were used to assess how well the PRP‐based estimates agreed with full‐mouth scores across levels of disease.

Results: Slightly higher levels of disease were evidenced on lingual than on buccal sites. Seven multi‐site PRPs and the Ramfjörd PRP produced small biases in MPPD (−0.17 to 0.04 mm) and MCAL with relative biases under 8% and 4% in absolute value for MPPD and MCAL, respectively. Biases for full‐ and random half‐mouth‐based PRPs were similar. The three‐site random half‐mouth MB–B–DL and the Ramfjörd PRPs produced the smallest biases, with relative biases <3% in absolute value for MPPD and MCAL.

Conclusions: Bias for MPPD or MCAL estimates varies by site type, number of sites per tooth and number of quadrants included in the PRP.
Melanoma stem cells: targets for successful therapy?
Authors: Houben Roland , Wischhusen Jörg , Menaa Farid , Synwoldt Peggy , Schrama David , Bröcker Eva‐Bettina , Becker Jürgen C.
Published: May 2008

Increasing evidence suggests that cancer is a disease in which the persistence of the tumor relies on a small population of tumor‐initiating cells, the so called tumor stem cells (TSC). Only these cells are capable of self‐renewal and thereby possess the ability for unlimited proliferation. One reason for the inability of conventional tumor treatments to achieve long‐term cures seems to be that TSC are resistant to many therapeutic approaches. A detailed characterization of TSC should have a substantial impact on the optimization of therapeutic protocols. While TSC in hematopoietic malignancies have been most intensively studied, subpopulations with stem cell properties have been identified in some solid tumors including breast carcinomas, gliomas and melanomas. In case of melanoma, however, a clear‐cut molecular characterization is still pending. Considerable research is needed to establish standard procedures for the isolation of melanoma stem cells to facilitate determining how these cells, critical for tumor persistence and progression, can be effectively eliminated. A pressing question is if melanoma stem cells are in principle sensitive to immunotherapy.
NMR study of cellulose and wheat straw degradation by Ruminococcus albus 20
Authors: Matulova Maria , Nouaille Régis , Capek Peter , Péan Michel , Delort Anne‐Marie , Forano Evelyne
Published: May 2008

Cellulose and wheat straw degradation by Ruminococcus albus was monitored using NMR spectroscopy. In situ solid‐state 13C‐cross‐polarization magic angle spinning NMR was used to monitor the modification of the composition and structure of cellulose and 13C‐enriched wheat straw during the growth of the bacterium on these substrates. In cellulose, amorphous regions were not preferentially degraded relative to crystalline areas by R. albus. Cellulose and hemicelluloses were also degraded at the same rate in wheat straw. Liquid state two‐dimensional NMR experiments were used to analyse in detail the sugars released in the culture medium, and the integration of NMR signals enabled their quantification at various times of culture. The results showed glucose and cellodextrin accumulation in the medium of cellulose cultures; the cellodextrins were mainly cellotriose and accumulated to up to 2 mm after 4 days. In the wheat straw cultures, xylose was the main soluble sugar detected (1.4 mm); arabinose and glucose were also found, together with some oligosaccharides liberated from hemicellulose hydrolysis, but to a much lesser extent. No cellodextrins were detected. The results indicate that this strain of R. albus is unable to use glucose, xylose and arabinose for growth, but utilizes efficiently xylooligosaccharides. R. albus 20 appears to be less efficient than Fibrobacter succinogenes S85 for the degradation of wheat straw.
FLIP and MAPK play crucial roles in the MLN51‐mediated hyperproliferation of fibroblast‐like synoviocytes in the pathogenesis of rheumatoid arthritis
Authors: Ha Ju‐Eun , Choi Young‐Eun , Jang Jinah , Yoon Cheol‐Hee , Kim Ho‐Youn , Bae Yong‐Soo
Published: May 2008

One of the characteristic features of the pathogenesis of rheumatoid arthritis is synovial hyperplasia. We have reported previously that metastatic lymph node 51 (MLN51) and granulocyte–macrophage colony‐stimulating factor (GM‐CSF) are involved in the proliferation of fibroblast‐like synoviocytes in the pathogenesis of rheumatoid arthritis. In this study, we have found that: (1) GM‐CSF‐mediated MLN51 upregulation is attributable to both transcriptional and post‐translational control in rheumatoid arthritis fibroblast‐like synoviocytes; (2) p38 mitogen‐activated protein kinase plays a key role in the upregulation of MLN51; and (3) FLICE‐inhibitory protein is upregulated downstream of MLN51 in response to GM‐CSF, resulting in the proliferation of fibroblast‐like synoviocytes. These results imply that GM‐CSF signaling activates mitogen‐activated protein kinase, followed by the upregulation of MLN51 and FLICE‐inhibitory protein, resulting in fibroblast‐like synoviocyte hyperplasia in rheumatoid arthritis.
A mechanism for short-lived cometary outbursts at sunrise as observed by Deep Impact on 9P/Tempel 1
Authors: Prialnik D. , A'Hearn M. F. , Meech K. J.
Published: May 2008

We explore a possible mechanism that may explain the outbursts observed by the Deep Impact mission on comet 9P/Tempel 1 that appear to occur near sunrise on a particular area. Assuming that the area is covered by a porous, poorly conducting dust layer, the heat wave generated by solar radiation at local noon propagates through the dust layer towards the ice-rich layer underneath it. The heated ice sublimates and the vapour flows towards the surface. However, by the time the heat wave reaches the ice, the spot has moved out of sunlight and its temperature has started dropping. As the vapour flows outwards, the surface has become so cold that it refreezes. Thus, at night some ice accumulates in the dust layer, very close to the surface. At sunrise, it immediately evaporates, producing a short-lived surge of activity. Numerical simulations of this mechanism provide the duration and water production of such outbursts, which are compatible with the 9P/Tempel 1 observations of small outbursts.
Prevalence and causes of visual impairment and blindness in Icelanders aged 50 years and older: the Reykjavik Eye Study
Authors: Gunnlaugsdottir Elin , Arnarsson Arsaell , Jonasson Fridbert
Published: May 2008

Purpose:  This study aimed to study the prevalences and causes of visual impairment and blindness in an Icelandic adult population.

Methods:  The Reykjavik Eye Study includes a random sample of citizens of Reykjavik aged ≥ 50 years, with an equal proportion (6.4%) for each year of birth and each sex. A total of 1045 persons were examined, representing a response rate of 75.8%. All participants underwent an extensive ophthalmological examination using a standard protocol. We used World Health Organization (WHO) definitions for bilateral visual impairment (best corrected visual acuity [VA] < 6/18 or visual field of ≥ 5 ° and < 10 ° around the fixation point in the better eye) and blindness (VA < 3/60 or visual field < 5 ° in the better eye). We also used US criteria, which define bilateral visual impairment as present if VA is < 6/12 and blindness as present if VA is ≤ 6/60 (both in the better eye). The causes of visual loss were determined for all participants found to be visually impaired in one or both eyes.

Results:  The prevalences of bilateral visual impairment and blindness were 0.96% (95% confidence interval [CI] 0.37–1.55) and 0.57% (95% CI 0.12–1.03), respectively, using the WHO criteria, and 2.01% (95% CI 1.16–2.86) and 0.77% (95% CI 0.24–1.29), respectively, using the US criteria. The prevalence rates were 4.40% and 5.45% for unilateral visual impairment and 1.72% and 3.06% for unilateral blindness, using the WHO and US criteria, respectively. Age‐related macular degeneration (AMD) was the major cause of bilateral visual loss, whereas the most common causes of unilateral visual loss were, in this order, amblyopia, cataract and glaucoma.

Conclusions:  Prevalence of visual loss increases with age. The leading cause of bilateral visual impairment and blindness was AMD, accounting for more than half of all cases, and cases of geographic atrophy outnumbered those of exudative AMD by two to one.
Therapeutic efficacy of intravitreal bevacizumab on posterior uveitis complicated by neovascularization
Authors: Kurup Shree , Lew Julie , Byrnes Gordon , Yeh Steven , Nussenblatt Robert , Levy‐Clarke Grace
Published: May 2008

Purpose:  To evaluate the therapeutic effect of intravitreal bevacizumab in patients with uveitis‐associated choroidal/retinal neovascularization.

Methods:  Two female patients (40 years, 15 years) with posterior uveitis, (one presumed ocular sarcoidosis, one lupus) were evaluated for neovascularization of the posterior segment. Both patients were given a single dose of 1.25 mg intravitreal bevacizumab.

Results:  Significant anatomical and functional recovery was evident in both patients within a few weeks.

Conclusion:  In selected uveitic patients, bevacizumab may be an option for managing neovascularization.
Initial segment Kv2.2 channels mediate a slow delayed rectifier and maintain high frequency action potential firing in medial nucleus of the trapezoid body neurons
Authors: Johnston Jamie , Griffin Sarah J. , Baker Claire , Skrzypiec Anna , Chernova Tatanya , Forsythe Ian D.
Published: May 2008

The medial nucleus of the trapezoid body (MNTB) is specialized for high frequency firing by expression of Kv3 channels, which minimize action potential (AP) duration, and Kv1 channels, which suppress multiple AP firing, during each calyceal giant EPSC. However, the outward K+ current in MNTB neurons is dominated by another unidentified delayed rectifier. It has slow kinetics and a peak conductance of ∼37 nS; it is half‐activated at −9.2 ± 2.1 mV and half‐inactivated at −35.9 ± 1.5 mV. It is blocked by several non‐specific potassium channel antagonists including quinine (100 μm) and high concentrations of extracellular tetraethylammonium (TEA; IC50= 11.8 mm), but no specific antagonists were found. These characteristics are similar to recombinant Kv2‐mediated currents. Quantitative RT‐PCR showed that Kv2.2 mRNA was much more prevalent than Kv2.1 in the MNTB. A Kv2.2 antibody showed specific staining and Western blots confirmed that it recognized a protein ∼110 kDa which was absent in brainstem tissue from a Kv2.2 knockout mouse. Confocal imaging showed that Kv2.2 was highly expressed in axon initial segments of MNTB neurons. In the absence of a specific antagonist, Hodgkin–Huxley modelling of voltage‐gated conductances showed that Kv2.2 has a minor role during single APs (due to its slow activation) but assists recovery of voltage‐gated sodium channels (Nav) from inactivation by hyperpolarizing interspike potentials during repetitive AP firing. Current‐clamp recordings during high frequency firing and characterization of Nav inactivation confirmed this hypothesis. We conclude that Kv2.2‐containing channels have a distinctive initial segment location and crucial function in maintaining AP amplitude by regulating the interspike potential during high frequency firing.
Probing Cold Dense Nuclear Matter
Authors: Subedi R. , Shneor R. , Monaghan P. , Anderson B. D. , Aniol K. , Annand J. , Arrington J. , Benaoum H. , Benmokhtar F. , Boeglin W. , Chen J.-P. , Choi Seonho , Cisbani E. , Craver B. , Frullani S. , Garibaldi F. , Gilad S. , Gilman R. , Glamazdin O. , Hansen J.-O. , Higinbotham D. W. , Holmstrom T. , Ibrahim H. , Igarashi R. , de Jager C. W. , Jans E. , Jiang X. , Kaufman L. J. , Kelleher A. , Kolarkar A. , Kumbartzki G. , LeRose J. J. , Lindgren R. , Liyanage N. , Margaziotis D. J. , Markowitz P. , Marrone S. , Mazouz M. , Meekins D. , Michaels R. , Moffit B. , Perdrisat C. F. , Piasetzky E. , Potokar M. , Punjabi V. , Qiang Y. , Reinhold J. , Ron G. , Rosner G. , Saha A. , Sawatzky B. , Shahinyan A. , SÌirca S. , Slifer K. , Solvignon P. , Sulkosky V. , Urciuoli G. M. , Voutier E. , Watson J. W. , Weinstein L. B. , Wojtsekhowski B. , Wood S. , Zheng X.-C. , Zhu L.
Published: May 2008

The protons and neutrons in a nucleus can form strongly correlated nucleon pairs. Scattering experiments, in which a proton is knocked out of the nucleus with high-momentum transfer and high missing momentum, show that in carbon-12 the neutron-proton pairs are nearly 20 times as prevalent as proton-proton pairs and, by inference, neutron-neutron pairs. This difference between the types of pairs is due to the nature of the strong force and has implications for understanding cold dense nuclear systems such as neutron stars.
Paleo-Eskimo mtDNA Genome Reveals Matrilineal Discontinuity in Greenland
Authors: Gilbert M. Thomas P. , Kivisild Toomas , Grønnow Bjarne , Andersen Pernille K. , Metspalu Ene , Reidla Maere , Tamm Erika , Axelsson Erik , Götherström Anders , Campos Paula F. , Rasmussen Morten , Metspalu Mait , Higham Thomas F. G. , Schwenninger Jean-Luc , Nathan Roger , De Hoog Cees-Jan , Koch Anders , Møller Lone Nukaaraq , Andreasen Claus , Meldgaard Morten , Villems Richard , Bendixen Christian , Willerslev Eske
Published: May 2008

The Paleo-Eskimo Saqqaq and Independence I cultures, documented from archaeological remains in Northern Canada and Greenland, represent the earliest human expansion into the New World's northern extremes. However, their origin and genetic relationship to later cultures are unknown. We sequenced a mitochondrial genome from a Paleo-Eskimo human by using 3400-to 4500-year-old frozen hair excavated from an early Greenlandic Saqqaq settlement. The sample is distinct from modern Native Americans and Neo-Eskimos, falling within haplogroup D2a1, a group previously observed among modern Aleuts and Siberian Sireniki Yuit. This result suggests that the earliest migrants into the New World's northern extremes derived from populations in the Bering Sea area and were not directly related to Native Americans or the later Neo-Eskimos that replaced them.
Throughfall and stemflow chemistry under deciduous and coniferous forest canopies in south-central Ontario
Authors: Neary A.J. , Gizyn W.I.
Published: May 2008

By measuring incident precipitation, throughfall, and stemflow chemistry, the roles of coniferous- and deciduous-dominated forest canopies as a source of and sink for ions in precipitation were examined. A regression technique for distinguishing between external (dry deposition) and internal (canopy leaching) sources of ions in the throughfall flux was evaluated. The effect of seasonal changes in the forest canopy on throughfall and stemflow chemistry was also examined. Throughfall comprised 74 and 84%, respectively, of the hydrologic flux at the coniferous and deciduous sites. Sulphate fluxes were highest at the coniferous site during both growing and dormant seasons, suggesting either a higher scavenging efficiency of the needles for atmospheric SO42−, or higher SO42− leaching from the foliage. The deciduous site neutralized acidic inputs, as demonstrated by its net negative H+ flux year round. The buffering capacity of the coniferous forest was exceeded by the higher amount of acid interception by the canopy. Nitrate behaved conservatively and base ions were exported from the canopy. Stemflow contributions of ions, although low, were generally higher than the contribution of stemflow to the hydrologic flux (2–3%). Independent dry deposition measurements for the growing season, when compared with net SO42− flux, overestimated dry deposition collected by the deciduous canopy, but were comparable to the flux at the coniferous site. These data suggest that dry SO2−SO42− deposition may be responsible for all SO42− enrichment seen in throughfall at these sites. A regression technique for separating internal and external ion sources in throughfall yielded inconsistent results, and attributed virtually all ion enrichment to internal sources. Problems with false assumptions and spurious correlations are discussed. We conclude that this method is not satisfactory for separating ion sources. Seasonal patterns in throughfall chemistry are present. During the growing seasons bases exchange for H+ and are exported similarly with SO42−. Hydrogen retention mirrors SO42− export. Base cations (particularly K+) are leached from the canopy primarily during senescence, but from the stem of the tree primarily during the dormant period. This was most evident at the deciduous site. Chloride behaved in a similar manner, while NH4+ and H+ were retained during the senescent period.
Growth of understory Piceaglauca, Calamagrostiscanadensis, and Epilobiumangustifolium in relation to overstory light transmission
Authors: Lieffers V.J. , Stadt K.J.
Published: May 2008

The potential for use of a partial canopy for controlling growth of Calamagrostiscanadensis (Michx.)•Beauv., and Epilobiumangustifolium L. among regenerating Piceaglauca (Moench) Voss saplings was assessed in the understory of 24 established stands in the P. glauca–Viburnum–Rubuspubescens association of the lower boreal cordilleran ecoregion of Alberta. Stand overstories were dominated by Populustremuloides Michx., P. glauca, or were a mixture of these two species The composition, basal area, and light transmission of the overstory of each stand were measured. Hardwood-dominated overstories transmitted between 14 and 40% of incoming light while P. glauca canopies transmitted between 5 and 11 % of light. Cover and height of C. canadensis and E. angustifolium decreased with decreasing light transmission; at 40% light, both species were greatly reduced compared with open-grown conditions and both were virtually eliminated from stands with less than 10% light. The annual height increment of P. glauca saplings increased from 5 cm at 10% light to 25 cm at 40 % light; the latter increment was approximately equal to growth in 100% light conditions. The number of buds, the diameter of the current leader, and the height to diameter ratio of the tree also increased with light transmittance.
Productivity and nutrient cycling in poplar stands in central Himalaya, India
Authors: Lodhiyal L.S. , Singh R.P. , Singh S.P.
Published: May 2008

Productivity and nutrient-use efficiency were investigated in plantations of similar age of poplar clone D121 (Populusdeltoides Marsh.) that differed mainly in plant density. The plantations were located in the Tarai belt (low-lying area with high water table) of the Indian Central Himalaya. The total net primary productivity of the high-density plantation (4 years old with 666 trees/ha) was conspicuously higher (32.4 tones•ha−1•year−1) than that of the low-density (20 tonnes•ha−1•year−1) plantation (5 years old with 400 trees/ha), while nutrient-use efficiency was similar in these plantations. The net primary productivity/leaf nutrient ratios and percent nutrient retranslocation from senescing leaves were higher in the high-density than in the low-density plantations. In these young plantations leaf litterfall accounted for most of the litterfall (96–97%). The amount of nutrients that returned through litterfall to the soil was distinctly greater in the high-density plantation than in the low-density plantation. The greater nutrient return was due to first, the greater dry weight of litterfall and the lower proportional nutrient retranslocation from leaves during senescence in the high-density plantation. The high-density plantation also showed greater nutrient extraction efficiency from soil. Compared with a Eucalyptustereticornis Sm. plantation, and with natural forests of the study region, the nutrient use efficiency of poplar, regardless of its density, was lower.
Genetic variation in tree structure and its relation to size in Douglas-fir. II. Crown form, branch characters, and foliage characters
Authors: St. Clair J.B.
Published: May 2008

Genetic variation and covariation among traits of tree size and structure were assessed in an 18-year-old Douglas-fir (Pseudotsugamenziesii var. menziesii (Mirb.) Franco) genetic test in the Coast Range of Oregon. Considerable genetic variation was found for relative crown width; stem increment per crown projection area; leaf area and branch weight relative to crown size; branch diameter and length adjusted for stem size; branch stoutness; cross-sectional area of branches per crown length; and needle size. Little genetic variation was found for branch numbers per whorl, branch angle, and specific leaf area. At both the phenotypic and genetic level, large trees growing well relative to growing space had tall, narrow crowns, high leaf areas per crown projection area or branch length, greater partitioning to leaves versus branches, and stouter branches. Thus, large, efficient trees were those that invested more in the photosynthetic machinery of leaf area and the branch biomass necessary to support that leaf area, but distributed that leaf area over a greater vertical distance. Unfortunately, these traits also were associated with increased branchiness, and selection for these traits would be accompanied by reductions in harvest index and wood quality.
Minimizing the cost of wildland fire suppression: a model with uncertainty in predicted flame length and fire-line width produced
Authors: Mees Romain , Strauss David , Chase Richard
Published: May 2008

We describe a model that estimates the optimal total expected cost of a wildland fire, given uncertainty in both flame length and fire-line width produced. In the model, a sequence of possible fire-line perimeters is specified, each with a forecasted control time. For a given control time and fire line, the probability of containment of the fire is determined as a function of the fire-fighting resources available. Our procedure assigns the resources to the fire line so as to minimize the total expected cost. A key feature of the model is that the probabilities reflect the degree of uncertainty in (i) the width of fire line that can be built with a given resource allocation, and (ii) the flame length of the fire. The total expected cost associated with a given choice of fire line is the sum of: the loss or gain of value of the area already burned; the cost of the resources used in the attack; and the expected loss or gain of value beyond the fire line. The latter is the product of the probability that the chosen attack strategy fails to contain the fire and the value of the additional burned area that would result from such a failure. The model allows comparison of the costs of the different choices of fire line, and thus identification of the optimal strategy. A small case study is used to illustrate the procedure.
Central endothelin: effects on vasopressin and the arterial baroreflex in doxorubicin heart failure ratsThis article is one of a selection of papers published in the special issue (part 1 of 2) on Forefronts in Endothelin.
Authors: Rossi Noreen F. , Maliszewska-Scislo Maria , Chen Haiping
Published: May 2008

Endothelin 1 (ET-1) is increased in heart failure, both in plasma and within the central nervous system. Centrally, ET-1 induces sympathetic hyperactivity and arginine vasopressin (AVP) secretion. Both sympathetic activity and AVP secretion are regulated by the arterial baroreflex, which is typically impaired in heart failure. We hypothesized that central blockade of ETA receptors (ETAR) alters the baroreflex response of heart rate, renal sympathetic nerve activity (RSNA), and plasma AVP levels in a cardiomyopathic model of heart failure. Female Sprague–Dawley rats received weekly intraperitoneal injections of doxorubicin 2.5 mg·kg–1 (doxorubicin heart failure, doxo-HF) or saline vehicle (control). After 8 weeks, they were instrumented, conditioned to the study environment, and then studied in the awake, non-restrained state. Baseline mean arterial pressure (MAP), RSNA, and plasma osmolality were similar in both groups, but heart rate (p < 0.02), left ventricular pressure (p < 0.001), and plasma AVP (p < 0.01) were higher in the doxo-HF group. ET-1 dose dependently increased MAP, but the rise was significantly attenuated in doxo-HF rats at all doses. Baseline baroreflex control of heart rate and RSNA was similar in both groups. ETAR blockade with 4 nmol BQ123 i.c.v. significantly decreased both the upper plateau (p < 0.05) and the range (p < 0.05) of the baroreflex response of both heart rate and RSNA in doxo-HF but not in control rats. Despite higher basal plasma levels of AVP, ET-1 evoked a rise in plasma AVP of 13.6 ± 3.2 pg·mL–1 in doxo-HF compared with 0.4 ± 0.4 pg·mL–1 in control rats (p < 0.001). To account for the blunted pressor response to ET-1 in the doxo-HF rats, gain of AVP release was calculated as ΔAVP/ΔMAP and was also found to be significantly greater in the doxo-HF rats (p < 0.001). BQ123 prevented the rise in AVP and restored the gain in doxo-HF rats to that seen in controls. Thus, central ETAR contribute to the sympathoexcitation and AVP responses observed in heart failure due to doxorubicin cardiomyopathy.