bluuebunny/crossref_metadata_2025 huggingface dataset:
Brief Report: Preliminary Results of a Suicide Awareness Mass Media Campaign in Cuyahoga County, Ohio
Authors: Oliver Richard J. , Spilsbury James C. , Osiecki Scott S. , Denihan William M. , Zureick Joel L. , Friedman Steve
Published: April 2008

Little information is currently available concerning the effects of suicide awareness and prevention campaigns. This brief report provides preliminary information about the influence of such a media campaign on the number of suicide‐related telephone calls to an emergency mental health service in Cuyahoga County, Ohio. Examination of the pattern of calls before, during, and between phases of the campaign suggests that the media campaign significantly increased telephone calls to the emergency service. We provide this information to catalyze similar sharing of data and experiences among those organizations and agencies working to prevent suicide.
Beyond Cat Scratch Disease: Widening Spectrum ofBartonella henselaeInfection
Authors: Florin Todd A. , Zaoutis Theoklis E. , Zaoutis Lisa B.
Published: April 2008

Bartonella henselae was discovered a quarter of a century ago as the causative agent of cat scratch disease, a clinical entity described in the literature for more than half a century. As diagnostic techniques improve, our knowledge of the spectrum of clinical disease resulting from infection with Bartonella is expanding. This review summarizes current knowledge regarding the microbiology, clinical manifestations, diagnostic techniques, and treatment of B henselae infection.
Prolonged Neonatal Jaundice and the Diagnosis of Biliary Atresia: A Single-Center Analysis of Trends in Age at Diagnosis and Outcomes
Authors: Wadhwani Sharad I. , Turmelle Yumirle P. , Nagy Rosemary , Lowell Jeffrey , Dillon Patrick , Shepherd Ross W.
Published: April 2008

Age at diagnosis is a modifiable risk factor in outcomes after hepatoportoenterostomy in biliary atresia; however, distinguishing biliary atresia from other more common causes of prolonged neonatal jaundice can be difficult. To focus attention on diagnosis of biliary atresia, we analyzed secular trends in the age at diagnosis, and other factors that might influence outcome. We performed a retrospective analysis of 55 consecutive infants with biliary atresia presenting to a single academic pediatric center over 15-year period from 1990 to 2004. The median age at diagnosis was 60 days (range: 21–152). In recent era (2000–2004), the median age was 69.0 days, compared with 48.5 days (1990–1994) and 59.5 days (1995–1999), respectively. Consistent with previous studies, the median age at diagnosis of those with poor outcomes (death or liver transplant) exceeded those with good outcomes after the hepatoportoenterostomy (72 vs 52 days, P < .001). The lack of improvement, or a concerning trends toward an increase in the age at diagnosis of biliary atresia, is perhaps attributable to neonatal follow-up practices. Efforts to make an earlier diagnose of this important condition deserve wider application and study.
Relay Writing in an Adolescent Online Community
Authors: Yi Youngjoo
Published: April 2008

“Welcome to Buckeye City” is an adolescent online community that was maintained by 25 Korean students who attended American schools. On the website, the students engaged in “relay writing”—a writing activity in which each person contributed a portion of an evolving story in a relayed manner. Relay writing offers teachers a new and valuable window into online literacy as well as adolescent literacy practices beyond school. The activity can help teachers understand adolescents' composing activities in voluntary (i.e., out‐of‐school) circumstances.
Independent Reading of CD‐ROM Storybooks: Measuring Comprehension With Oral Retellings
Authors: Pearman Cathy J.
Published: April 2008

CD‐ROM storybooks may facilitate reading comprehension for students who are struggling with reading comprehension. Therefore, the use of CD‐ROM storybooks in the classroom as part of a reading instruction program, literacy center, or for independent reading time could benefit young readers.
Show Me: Principles for Assessing Students' Visual Literacy
Authors: Callow Jon
Published: April 2008

This article examines assessment of students' visual literacy. In the context of current theory of multimodal texts, the author presents key features for visual literacy assessment and how this assessment might be undertaken. The article then proposes a set of principles and a framework for developing assessment tasks in authentic classroom settings.
Phonemes in Use: Multiple Activities for a Critical Process
Authors: Manyak Patrick C.
Published: April 2008

Several decades of research have established the critical role of phonemic awareness in the development of beginning reading. In particular, phonemic awareness makes early phonics instruction useful for children and facilitates their ability to blend letter sounds while decoding words, to learn sight words reliably, and to spell phonetically.

A key finding in phonemic awareness research is that instruction involving segmenting and blending phonemes combined with a focus on the letters that represent those phonemes contributes greatly to success in beginning reading and spelling. The author found that students benefit greatly from a variety of activities combining phoneme segmenting and blending with letter—sound instruction. This variety allows children to develop a robust ability to apply phonemic awareness to tasks of reading and writing and supports students who may struggle with this critical process. In this article, the author describes five “phonemes‐in‐use” activities and practical ideas for implementing them in the classroom.
Prediction of relative electrical conductivity of saturated cement paste
Authors: Zheng J. J. , Zhou X. Z.
Published: April 2008

Owing to its importance both in assessing the microstructural development and in computing the ionic diffusivity and permeability, it is of great practical significance to determine the relative electrical conductivity of saturated cement paste. This paper presents an analytical solution for the relative electrical conductivity of saturated cement paste. By modelling saturated cement paste as a two-phase composite material, consisting of capillary pores, and hydrated products and unhydrated cement grains, an analytical solution is derived for the relative electrical conductivity of saturated cement paste based on the general effective medium theory. Two parameters involved in the analytical solution are then determined by experimental calibration. After verifying the analytical solution with two sets of experimental results obtained from the literature, the effects of the water/cement (w/c) ratio and the degree of hydration on the relative electrical conductivity of saturated cement paste are evaluated in a quantitative manner. It is found that the relative electrical conductivity of saturated cement paste decreases with the decrease of the w/c ratio and/or with the increase of the degree of hydration. The paper concludes that the analytical solution presented can predict the relative electrical conductivity of saturated cement paste with reasonable accuracy.
Cracking in deep beams owing to shear loading. Part 2: Non-linear analysis
Authors: Malm R. , Holmgren J.
Published: April 2008

In this paper, analyses based on laboratory tests of ten large deep beams with I-shaped cross-sections loaded to failure are presented. All beams had the same geometry with a shear span-to-depth ratio of 1·25, but differed in the amount of the vertical and horizontal web reinforcement. All beam tests resulted in shear failure, either diagonal tensile failure or shear compressive failure, depending on the amount of reinforcement. The diagonal tensile failure is generally considered to be the most difficult failure to treat numerically. In this study different material models incorporated in commercial numerical analysis tools are studied. Material models based on fracture mechanics with either rotated or fixed crack directions as well as a plasticity-based model are used in the analyses. The analyses show that the plasticity-based model in Abaqus gives good agreement with the experiments regarding crack pattern, load–displacement response and estimated crack widths. The models based on fracture mechanics in Atena and Response tend to give too stiff behaviour in the load–displacement response, but generally give a good estimation of the load capacity. The analyses performed with Atena gave good estimations of the crack pattern, and the models with a fixed crack direction also gave good estimates of the crack width.
More than inorganic copper is bioavailable to aquatic mosses at environmentally relevant concentrations
Authors: Ferreira Daniel , Tousset Nicolas , Ridame Céline , Tusseau-Vuillemin Marie-Hélène
Published: April 2008

The present study investigates how dissolved organic matter (DOM) alters copper bioavailability at environmentally relevant concentrations (1–5 μg/L of dissolved copper, 1–4 mg/L of dissolved organic copper). A methodology combining two biological endpoints (short-term and steady-state bioaccumulation of copper by the aquatic moss Fontinalis antipyretica) and a sampling of labile copper with diffusion gradient in thin films (DGT) is proposed for batch experiments conducted with mineral water and various DOM, ethylenediaminetetra-acetic acid (EDTA), humic acid, and natural Seine River (France) extracts (hydrophobic and transphilic fractions). All types of DOM reduce the bioavailability of copper to aquatic mosses, and this reduction was more pronounced for the short-term biological endpoint, which was taken as being representative for environmental exposure. Labile copper sampled with DGT made it possible to estimate short-term bioaccumulation in the case of EDTA and natural Seine River extracts. With humic acid solutions, however, labile copper was lower than bioavailable copper. This result suggests that at realistic metal concentrations and with certain types of natural DOM, bioavailable copper might comprise not only inorganic copper but also some weak organic complexes. Hence, labile copper, in situ sampled with DGT, might not systematically overestimate bioavailable copper, as suggested previously on the basis of in vitro toxicity studies.
Differential metallothionein induction patterns in fed and starved carp (Cyprinus carpio) during waterborne copper exposure
Authors: Hashemi Shodja , Kunwar Prabesh S , Blust Ronny , De Boeck Gudrun
Published: April 2008

Starved and fed carp (Cyprinus carpio) were exposed to sublethal waterborne copper exposure (1 μM) for 28 d in softened Antwerp, Belgium, city tap water. Copper accumulation in liver and gill tissues was determined, and changes in branchial Na+/K+–adenosine 5′-triphosphatase (ATPase) activity and metallothionein (MT) induction in gill and liver tissues were investigated following 28-d copper exposure. Gill Na+/K+-ATPase activity in exposed fish, both starved and fed, was at its lowest values after 3 d of exposure, after which it slowly recovered to preexposure values. No significant differences in branchial Na+/K+-ATPase activity were found between starved and fed fish. Copper accumulation in the liver and gills of the exposed starved carp was significantly higher than that in the exposed fed carp. The highest MT induction was found in liver tissues. Different patterns of MT induction were observed in the starved and fed carp during copper exposure. Before exposure, MT concentrations in the livers of the starved fish were significantly higher than those in the fed ones. Copper exposure significantly increased MT concentration in the liver of the fed fish, but no changes occurred in the starved fish. In contrast, copper exposure increased MT concentrations in the gills of the starved fish during the first week of exposure, whereas only a slight increase in MT concentration in the gills of the fed fish was observed. When taking into account the role of feeding status in MT induction, hepatic MT was a more relevant indicator for long-term monitoring of copper pollution in carp, but gill MT provided useful information regarding short-term copper toxicity.
Butyltin accumulation in two marine bivalves along a pollution gradient
Authors: Tang Chuan-Ho , Wang Wei-Hsien
Published: April 2008

In the present study, we describe a field survey regarding the effect of ambient water conditions in the accumulation of tributyltin (TBT) and its metabolites in green mussels (Perna viridis) and Pacific oysters (Crassostrea gigas). The results showed that following the changes in TBT pollution levels, the accumulation of butyltins exhibited clear differences between oysters and mussels. The ratio of TBT to total butyltin (TBT:ΣBT) decreased from 0.87 to 0.31 with increasing TBT burdens in the oysters. This status suggests that following the increases of TBT burdens, the metabolic rates of TBT were clearly enhanced in oysters; however, this phenomenon was not shown in mussels. The TBT:ΣBT remained relatively constant at approximately 0.7 in the mussels despite the TBT burdens. Because of this phenomenon, the opposite status of different TBT burdens between oysters and mussels were present at different TBT pollution levels. These observations may provide valuable insight when evaluating or comparing TBT pollution in the environment using oysters and/or mussels as bioindicators.
Recommendable block sizes: a case study on Finnish official variety trials of barley cultivars
Authors: JAUHIAINEN L. , ÖFVERSTEN J. , KANGAS A.
Published: April 2008

Lajikekokeet ovat tyypillisesti kokeita, joissa vertailtavien käsittelyjen eli lajikkeiden määrä on suuri, jopa useita kymmeniä lajikkeita. Tutkimuksessa käytetty aineisto sisälsi 28 virallista ohran lajikekoetta vuosilta 20012005. Tyypillisessä epätäydellisten lohkojen koeasetelman mukaisesti suunnitellussa ohran lajikekokeessa lohkot sisältävät 67 lajiketta, mutta tulosten perusteella vain 45 lajiketta kannattaisi sijoittaa samaan lohkoon. Tulosten perusteella voidaan olettaa epätäydellisten lohkojen koeasetelmista olevan hyötyä myös pienissä, jopa 710 käsittelyn peltokokeissa. Tulokset osoittavat lisäksi, että oikein käytettyinä epätäydellisten lohkojen koeasetelmien avulla pystytään huomioimaan pellolla esiintyvä sangen nopeakin vaihtelu niin hyvin, ettei tarvetta ole siirtyä käyttämään monimutkaisempia tilastollisia menetelmiä, joita ovat mm. koeruutujen välisen spatiaalisen riippuvuuden huomioivat sekamallit.;
Effect of cropping system and peat amendment on strawberry growth and yield
Authors: VESTBERG M. , KUKKONEN S. , KURU H.
Published: April 2008

Comparative studies have usually shown higher yields in conventional cropping systems (CCS) than in organic cropping systems (OCS). By utilizing a long-term field experiment on silt soil with 18 years of cropping history (19821999), including three OCSs and one CCS, we studied if this is true also for strawberry. The strawberry experiment was conducted in 20002002. The experiment had one CCS (A) and three OCSs (B,C,D). The impact of pre-planting peat amendment was also studied. The degree of overwintering, fruit yields, yield components and some soil nutrients were determined. Total and marketable fruit yields were estimated using a peduncle analysis based on weights of fruits of different orders in the peduncle, numbers of healthy and injured fruits in the peduncle and the number of peduncles per plant. The shoot growth, total and marketable fruit yields, as well as all yield components estimated were significantly higher in the OCS rotation D than in the CCS rotation A. The peat amendment, but not the cropping system, decreased the percentage of strawberry plants suffering from or killed by winter damage. However, peat amendment did not affect yield. The cropping system had no impact on soil pH, or the amount of extractable calcium, magnesium and nitrate. Extractable phosphorus and potassium were higher and soil organic carbon (Corg) slightly higher in the OCS than in the CCS. The peat amendment increased Corg by 2%. The amounts of extractable nutrients in soil were not a limiting factor for strawberry growth and yield as they were of sufficient levels both in CCS and OCS. It remains unclear whether the higher yield in the OCS was due to a long-term cropping history or to a short-term effect of composted manure, or to a combination of these two. The importance of soil organic management in strawberry production is emphasized.;
The effect of single farm payments on less favoured areas agriculture in Scotland: a CGE analysis
Authors: GELAN A. , SCHWARZ G.
Published: April 2008

This study quantifies impacts of common agricultural policy reform on farming in Less Favoured Areas (LFAs) in Scotland. LFAs are characterised by low agricultural productivity, because of unfavourable natural conditions, which allow only extensive farming systems such as cattle and sheep rearing. The differential impacts of the single farm payment on LFA farming is examined using a CGE modeling framework that accounts for inter-sectoral linkage effects. The simulation results indicate that the policy reform has considerably larger adverse effects on LFA farms than non-LFA farms and emphasize the need to consider spatially differential impacts in further adjustments to policy reforms taking into account local circumstances.;
Effects of Landscape Composition on Winter Survival of Northern Bobwhites
Authors: SECKINGER ERIC M. , BURGER L. WES , WHITTINGTON RACHEL , HOUSTON ALLAN , CARLISLE RICK
Published: April 2008

Abstract: In a manipulative experiment, we tested effects of select elements of landscape structure and composition on winter survival of northern bobwhites (Colinus virginianus) at Ames Plantation, Tennessee, USA. We hypothesized that abundance of closed canopy forested habitats (52% of the landscape) on Ames diminished usable space for bobwhite and provided usable space for a suite of important predators, thereby contributing to low winter survival. To test this hypothesis we divided a 2,217‐ha portion of the property into 4 approximately equal areas. We altered landscape structure and composition by converting approximately 33% of the timber to early successional herbaceous plant communities on 2 treatment sites, which reduced percentage of landscape and edge density of closed canopy forest and increased percentage of landscape in early successional herbaceous communities, and left 2 control sites in their former composition. During one pretreatment year (1998–1999) and 3 posttreatment years (1999–2000, 2000–2001, 2001–2002), we estimated winter (15 Oct‐10 Apr) survival on treatment and control sites from a radiomarked sample of 920 bobwhites. We used Cox Proportional Hazard models to test for effects of treatment (forest conversion) and covariates describing landscape structure and composition (% closed canopy forest, % early successional herbaceous, wooded edge density) on winter survival at multiple spatial scales. Winter survival on the treatment sites pooled across the 4 winter seasons was 41% compared to 32% for control sites. Additionally, for each 1 m/ha increase in closed canopy woods edge density within winter covey ranges, risk of mortality increased 0.3%. Our results suggest composition at the landscape scale and landscape structure at the local scale influence winter survival of bobwhite. Management strategies that alter composition and structure and increase usable space may be effective in mitigating winter mortality thereby altering population trajectories. Typical bobwhite management plans focus on improving quality of herbaceous vegetation structure within existing herbaceous patches, however, population processes may work at larger spatial scales influencing design and implementation of conservation programs.
Demography of Black Bears in Hunted and Unhunted Areas of the Boreal Forest of Ontario
Authors: OBBARD MARTYN E. , HOWE ERIC J.
Published: April 2008

Abstract: We estimated relative density, survival, and reproduction of American black bears (Ursus americanus) from capture‐recapture and telemetry data collected from 1989 to 1999 in the unhunted Chapleau Crown Game Preserve (CCGP) and nearby hunted areas in the boreal forest of Ontario, Canada. We tested for combinations of effects of age class, sex, year, years of food shortage, encumbrance status, and residency (on or off the Game Preserve) on vital rates. Results from live captures, remote captures, and bait‐station hit rates indicated that density was highest inside CCGP. Total survival of adult females, subadults, and cubs were similar among residents and nonresidents of CCGP, but yearling survival was lower among CCGP residents. Adult females were approximately twice as likely to die and nearly 10 times as likely to be cannibalized (risk ratio [RR] = 9.62, 95% CI = 2.088–44.29) while encumbered with cubs of the year. Nonresidents of CCGP had greater risk of being harvested (RR = 4.00, 95% CI = 1.19–13.46) but similar risk of being cannibalized (RR = 0.875, 95% CI = 0.300–2.55) relative to CCGP residents, suggesting that harvest mortality was additive to other forms of mortality. Residents of CCGP had older ages at primiparity and lower litter‐production rates than bears resident in hunted areas. Few litters were produced in years following food shortages, but litter size was unaffected. We recommend that managers allow for additive harvest mortality and reduced survival of bears encumbered with cubs of the year, and we caution that assuming density‐compensatory increases in cub production could optimistically bias estimates of population growth.
Scale‐Dependent Effects of Landscape Structure and Composition on Diurnal Roost Selection by Forest Bats
Authors: PERRY ROGER W. , THILL RONALD E. , LESLIE DAVID M.
Published: April 2008

Abstract: Forest management affects the quality and availability of roost sites for forest‐dwelling bats, but information on roost selection beyond the scale of individual forest stands is limited. We evaluated effects of topography (elevation, slope, and proximity of roads and streams), forest habitat class, and landscape patch configuration on selection of summer diurnal roosts by 6 species of forest‐dwelling bats in a diverse forested landscape of the Ouachita Mountains, Arkansas, USA. Our objectives were to identify landscape attributes that potentially affect roost placement, determine whether commonalities exist among species in their response to landscape attributes, and evaluate the effects of scale. We modeled roost selection at 2 spatial scales (250‐ and 1,000‐m radius around each roost). For each species, parameters included in models differed between the 2 scales, and there were no shared parameters for 2 species. Average coefficients of determination (R2) for small‐scale models were generally higher than for large‐scale models. Abundance of certain forest habitat classes were included more often than patch configuration or topography in differentiating roost from random locations, regardless of scale, and most species were more likely to roost in areas containing abundant thinned forest. Among topographic metrics, big brown bats (Eptesicus fuscus) were more likely to roost at higher elevations; roosts of big brown bats, northern long‐eared bats (Myotis septentrionalis), and Seminole bats (Lasiurus seminolus) were influenced by slope; and big brown bats, evening bats (Nycticeius humeralis), and Seminole bats were more likely to roost closer to water than random. Northern long‐eared bats and red bats (Lasiurus borealis) were more likely to roost closer to roads, whereas eastern pipistrelles (Perimyotis subflavus) were more likely to roost further from roads than random. Common parameters in most models included 1) positive associations with group selection (5 of 6 species) and thinned mature forest (4 species) at the small scale; 2) negative associations with unmanaged mixed pine‐hardwood forest 50–99 years old at the large scale (4 species); 3) negative association with stands of immature pine 15–29 years old at the small scale (3 species); and 4) a positive association with largest patch index at the large scale (3 species). Our results suggest that, in a completely forested landscape, a variety of stand types, seral stages, and management conditions, varying in size and topographic location throughout the landscape, would likely provide the landscape components for roosting required to maintain a diverse community of forest bats in the Ouachita Mountains.
Direct Estimation of Early Survival and Movements in Eastern Wolf Pups
Authors: MILLS KENNETH J. , PATTERSON BRENT R. , MURRAY DENNIS L.
Published: April 2008

Abstract:Determining juvenile survival and recruitment rates is essential to assess status and viability of animal populations. Currently, the demographic attributes of juvenile carnivores, specifically wolves (Canis lycaon), are poorly known but of considerable conservation interest. We measured survival and dispersal rates for 51 juvenile (age 3.5–31 weeks) wolves in Algonquin Provincial Park, Canada, from 2004 to 2005, using implantable very high frequency transmitters. Monthly pup survival was high (0.970, 95% CI = 0.951–0.990) and constant from June to November, and most pup mortality was from natural causes. Pups dispersed as early as age 15 weeks, and monthly dispersal rates were high for young pups (min. = 0.008, 95% CI = 0.000–0.019; max. = 0.030, 95% CI = 0.010–0.050). We failed to detect any influence of pack or litter size on pup survival or probability of dispersal. Radiotelemetry offers an individual‐based monitoring technique capable of providing direct assessment of wolf pup survival and movements, with rigorous estimation of survival and dispersal rates and quantification of cause‐specific mortality.
Using Viewsheds to Determine Area Sampled by Ground‐Based Radiotelemetry
Authors: ETHERINGTON THOMAS R. , ALEXANDER SHELLEY M.
Published: April 2008

Abstract: Geographic Information System (GIS) viewsheds have been suggested as a possible way to determine area sampled by ground telemetry. Although this would be useful information to have, there has been little use of the technique. To investigate if viewsheds could be of use, we produced a telemetry viewshed and compared the results to previously collected radiotelemetry data. Given positive initial results and potential applications, we think GIS viewsheds could be useful for radiotelemetry studies and we encourage further research in this area.
Northern Goshawk Habitat: an Intersection of Science, Management, and Conservation
Authors: REYNOLDS RICHARD T. , GRAHAM RUSSELL T. , BOYCE DOUGLAS A.
Published: April 2008

Abstract:We responded to the claim by Greenwald et al. (2005) that the management recommendations for the northern goshawk in the Southwestern United States (MRNG; Reynolds et al. 1992), a food web‐based conservation plan that incorporated both northern goshawk (Accipiter gentilis) and multiple prey habitats, may be inadequate to protect goshawks. Greenwald et al. (2005) based this claim on their review of 12 telemetry studies of goshawk habitat selection and 5 nontelemetry studies of the effects of vegetation structure at the home range scale on goshawk nest occupancy and reproduction that appeared after the 1992 publication of the MRNG. Greenwald et al. (2005) summarized their review as showing that 1) goshawks were habitat specialists limited to forests with mature and old‐growth structures including large trees, high canopy cover, multiple canopy layering, and abundant woody debris; 2) habitats were not selected on the basis of prey abundance and, therefore, managing for prey habitats diluted goshawk habitats; and 3) selection for openings, edges, and habitat diversity was inconclusive. Our review found that when the studies' respective authors pooled their radiotagged goshawks there were weak to strong selections for old forest structures. However, the studies also documented extensive variation in use of vegetation types and structures by individual goshawks; some avoided openings, edges, young forests, and old forests, whereas others selected for these characteristics. Additionally, by virtue of their wide geographic distribution, the studies showed that the focal populations themselves occurred in a variety of forest types, some with large structural differences. We found no evidence in Greenwald's et al. (2005) review that the MRNG are inadequate to protect goshawks. Rather, the studies reviewed by Greenwald et al. (2005), as well as many studies they missed, supported the MRNG. The suggestion of inadequacy by Greenwald et al. (2005) appeared rooted in misunderstandings of goshawk habitats described in the MRNG, a discounting of the extent of variation in vegetation structural and seral stages used by goshawks, a limited understanding of the extent to which prey limits goshawks, a failure to recognize the dynamic nature of forests, and an incomplete review of the literature. We believe the MRNG are adequate because they maximize the sustainable amount of mature and old forests in goshawk home ranges and specify the kinds and intermixtures of prey habitats within home ranges. Implementation of MRNG should reduce the likelihood that the availability of vegetation structures suited to goshawk nesting and foraging, as well as abundance and availability of prey, will limit goshawk nest occupancy and reproduction.
Exposure to Maternal Diabetes Induces Salt-Sensitive Hypertension and Impairs Renal Function in Adult Rat Offspring
Authors: Nehiri Touria , Duong Van Huyen Jean-Paul , Viltard Mélanie , Fassot Céline , Heudes Didier , Freund Nicole , Deschênes Georges , Houillier Pascal , Bruneval Patrick , Lelièvre-Pégorier Martine
Published: April 2008

OBJECTIVE—Epidemiological and experimental studies have led to the hypothesis of fetal origin of adult diseases, suggesting that some adult diseases might be determined before birth by altered fetal development. We have previously demonstrated in the rat that in utero exposure to maternal diabetes impairs renal development leading to a reduction in nephron number. Little is known on the long-term consequences of in utero exposure to maternal diabetes. The aim of the study was to assess, in the rat, long-term effects of in utero exposure to maternal diabetes on blood pressure and renal function in adulthood.

RESEARCH DESIGN AND METHODS—Diabetes was induced in Sprague-Dawley pregnant rats by streptozotocin on day 0 of gestation. Systolic blood pressure, plasma renin activity, and renal function were measured in the offspring from 1 to 18 months of age. High-salt diet experiments were performed at the prehypertensive stage, and the abundance of tubular sodium transporters was evaluated by Western blot analysis. Kidney tissues were processed for histopathology and glomerular computer-assisted histomorphometry.

RESULTS AND CONCLUSIONS—We demonstrated that in utero exposure to maternal diabetes induces a salt-sensitive hypertension in the offspring associated with a decrease in renal function in adulthood. High-salt diet experiments show an alteration of renal sodium handling that may be explained by a fetal reprogramming of tubular functions in association or as a result of the inborn nephron deficit induced by in utero exposure to maternal diabetes.
Association Analysis in African Americans of European-Derived Type 2 Diabetes Single Nucleotide Polymorphisms From Whole-Genome Association Studies
Authors: Lewis Joshua P. , Palmer Nicholette D. , Hicks Pamela J. , Sale Michele M. , Langefeld Carl D. , Freedman Barry I. , Divers Jasmin , Bowden Donald W.
Published: April 2008

OBJECTIVE— Several whole-genome association studies have reported identification of type 2 diabetes susceptibility genes in various European-derived study populations. Little investigation of these loci has been reported in other ethnic groups, specifically African Americans. Striking differences exist between these populations, suggesting they may not share identical genetic risk factors. Our objective was to examine the influence of type 2 diabetes genes identified in whole-genome association studies in a large African American case-control population.

RESEARCH DESIGN AND METHODS— Single nucleotide polymorphisms (SNPs) in 12 loci (e.g., TCF7L2, IDE/KIF11/HHEX, SLC30A8, CDKAL1, PKN2, IGF2BP2, FLJ39370, and EXT2/ALX4) associated with type 2 diabetes in European-derived populations were genotyped in 993 African American type 2 diabetic and 1,054 African American control subjects. Additionally, 68 ancestry-informative markers were genotyped to account for the impact of admixture on association results.

RESULTS— Little evidence of association was observed between SNPs, with the exception of those in TCF7L2, and type 2 diabetes in African Americans. One TCF7L2 SNP (rs7903146) showed compelling evidence of association with type 2 diabetes (admixture-adjusted additive P [Pa] = 1.59 × 10−6). Only the intragenic SNP on 11p12 (rs9300039, dominant P [Pd] = 0.029) was also associated with type 2 diabetes after admixture adjustments. Interestingly, four of the SNPs are monomorphic in the Yoruba population of the HAPMAP project, with only the risk allele from the populations of European descent present.

CONCLUSIONS— Results suggest that these variants do not significantly contribute to interindividual susceptibility to type 2 diabetes in African Americans. Consequently, genes contributing to type 2 diabetes in African Americans may, in part, be different from those in European-derived study populations. High frequency of risk alleles in several of these genes may, however, contribute to the increased prevalence of type 2 diabetes in African Americans.
Protein Kinase C-δ Mediates Neuronal Apoptosis in the Retinas of Diabetic Rats via the Akt Signaling Pathway
Authors: Kim Young-Hee , Kim Yoon-Sook , Park Chang-Hwan , Chung In-Yong , Yoo Ji-Myong , Kim Jae-Geun , Lee Byung-Ju , Kang Sang-Soo , Cho Gyeong-Jae , Choi Wan-Sung
Published: April 2008

OBJECTIVE—Protein kinase C (PKC)-δ, an upstream regulator of the Akt survival pathway, contributes to cellular dysfunction in the pathogenesis of diabetes. Herein, we examined the role of PKC-δ in neuronal apoptosis through Akt in the retinas of diabetic rats.

RESEARCH DESIGN AND METHODS—We used retinas from 24- and 35-week-old male Otsuka Long-Evans Tokushima fatty (OLETF) diabetic and Long-Evans Tokushima Otsuka (LETO) nondiabetic rats. To assess whether PKC-δ affects Akt signaling and cell death in OLETF rat retinas, we examined 1) PKC-δ activity and apoptosis; 2) protein levels of phosphatidylinositol 3-kinase (PI 3-kinase) p85, heat shock protein 90 (HSP90), and protein phosphatase 2A (PP2A); 3) Akt phosphorylation; and 4) Akt binding to HSP90 or PP2A in LETO and OLETF retinas in the presence or absence of rottlerin, a highly specific PKC-δ inhibitor, or small interfering RNAs (siRNAs) for PKC-δ and HSP90.

RESULTS—In OLETF retinas from 35-week-old rats, ganglion cell death, PKC-δ and PP2A activity, and Akt-PP2A binding were significantly increased and Akt phosphorylation and Akt-HSP90 binding were decreased compared with retinas from 24-week-old OLETF and LETO rats. Rottlerin and PKC-δ siRNA abrogated these effects in OLETF retinas from 35-week-old rats. HSP90 siRNA significantly increased ganglion cell death and Akt-PP2A complexes and markedly decreased HSP90-Akt binding and Akt phosphorylation in LETO retinas from 35-week-old rats compared with those from nontreated LETO rats.

CONCLUSIONS—PKC-δ activation contributes to neuro-retinal apoptosis in diabetic rats by inhibiting Akt-mediated signaling pathways.
Autocrine IGF-1 Action in Adipocytes Controls Systemic IGF-1 Concentrations and Growth
Authors: Klöting Nora , Koch Linda , Wunderlich Thomas , Kern Matthias , Ruschke Karen , Krone Wilhelm , Brüning Jens C. , Blüher Matthias
Published: April 2008

OBJECTIVE—IGF-1 and the IGF-1 receptor (IGF-1R) have been implicated in the regulation of adipocyte differentiation and lipid accumulation in vitro.

RESEARCH DESIGN AND METHODS—To investigate the role of IGF-1 receptor in vivo, we have inactivated the Igf-1r gene in adipose tissue (IGF-1RaP2Cre mice) using conditional gene targeting strategies.

RESULTS—Conditional IGF-1R inactivation resulted in increased adipose tissue mass with a predominantly increased lipid accumulation in epigonadal fat pads. However, insulin-stimulated glucose uptake into adipocytes was unaffected by the deletion of the IGF-1R. Surprisingly, IGF-1RaP2Cre mice exhibited markedly increased somatic growth in the presence of elevated IGF-1 serum concentrations, and IGF-1 mRNA expression was significantly increased in liver and adipose tissue. IGF-1 stimulation of wild-type adipocytes significantly decreased IGF-1 mRNA expression, whereas the opposite effect was observed in IGF-1R–deficient adipocytes.

CONCLUSIONS—IGF-1R signaling in adipocytes does not appear to be crucial for the development and differentiation of adipose tissue in vivo, but we identified a negative IGF-1R–mediated feedback mechanism of IGF-1 on its own gene expression in adipocytes, indicating an unexpected role for adipose tissue IGF-1 signaling in the regulation of IGF-1 serum concentrations in control of somatic growth.
Diabetes Risk Calculator
Authors: Heikes Kenneth E. , Eddy David M. , Arondekar Bhakti , Schlessinger Leonard
Published: April 2008

OBJECTIVE—The objective of this study was to develop a simple tool for the U.S. population to calculate the probability that an individual has either undiagnosed diabetes or pre-diabetes.

RESEARCH DESIGN AND METHODS—We used data from the Third National Health and Nutrition Examination Survey (NHANES) and two methods (logistic regression and classification tree analysis) to build two models. We selected the classification tree model on the basis of its equivalent accuracy but greater ease of use.

RESULTS—The resulting tool, called the Diabetes Risk Calculator, includes questions on age, waist circumference, gestational diabetes, height, race/ethnicity, hypertension, family history, and exercise. Each terminal node specifies an individual's probability of pre-diabetes or of undiagnosed diabetes. Terminal nodes can also be used categorically to designate an individual as having a high risk for 1) undiagnosed diabetes or pre-diabetes, 2) pre-diabetes, or 3) neither undiagnosed diabetes or pre-diabetes. With these classifications, the sensitivity, specificity, positive and negative predictive values, and receiver operating characteristic area for detecting undiagnosed diabetes are 88%, 75%, 14%, 99.3%, and 0.85, respectively. For pre-diabetes or undiagnosed diabetes, the results are 75%, 65%, 49%, 85%, and 0.75, respectively. We validated the tool using v-fold cross-validation and performed an independent validation against NHANES 1999–2004 data.

CONCLUSIONS—The Diabetes Risk Calculator is the only currently available noninvasive screening tool designed and validated to detect both pre-diabetes and undiagnosed diabetes in the U.S. population.
Tissue Plasminogen Activator, von Willebrand Factor, and Risk of Type 2 Diabetes in Older Men
Authors: Wannamethee S. Goya , Sattar Naveed , Rumley Ann , Whincup Peter H. , Lennon Lucy , Lowe Gordon D.O.
Published: April 2008

OBJECTIVE—The objective of this study was to assess the relationship between putative markers of endothelial dysfunction (tissue plasminogen activator [t-PA] antigen and von Willebrand factor [vWF] antigen) and development of type 2 diabetes, as well as the role of inflammation, adipokines, hepatic function, and insulin resistance in modifying these relationships.

RESEARCH DESIGN AND METHODS—This was a prospective study of 3,562 nondiabetic men aged 60–79 years followed up for an average of 7 years during which there were 162 incident cases of type 2 diabetes.

RESULTS—Elevated t-PA (top third) was associated with a near threefold increase in risk of diabetes compared with the risk in those in the bottom third after adjustment for lifestyle factors and waist circumference (relative risk [RR] 2.98 [95%CI 1.79–5.00]; Ptrend < 0.0001); weaker but significant (marginal) associations were seen with vWF (1.24 [0.83–1.85]; P = 0.05 for trend). Both biomarkers of endothelial dysfunction correlated significantly with markers of inflammation (interleukin-6 [IL-6] and C-reactive protein [CRP]), hepatic function (γ-glutamyl transferase [GGT]), and insulin resistance, with t-PA showing stronger associations with adiposity, hepatic function, and insulin resistance than vWF. t-PA was also significantly and inversely associated with adiponectin. Adjustment for IL-6, adiponectin, and GGT attenuated the association of incident diabetes with vWF (1.06 [0.71–1.60]), but the relationship seen with t-PA remained significant (adjusted RR 2.19 [1.29–3.70]). Subsequent adjustment for insulin attenuated the association further, but t-PA was still associated with a significant increase in risk (1.66 [0.96–2.85]; Ptrend = 0.02).

CONCLUSION—t-PA antigen, but not vWF antigen, is independently associated with risk of type 2 diabetes.
Serial Measurements of Cystatin C Are More Accurate Than Creatinine-Based Methods in Detecting Declining Renal Function in Type 1 Diabetes
Authors: Premaratne Erosha , MacIsaac Richard J. , Finch Sue , Panagiotopoulos Sianna , Ekinci Elif , Jerums George
Published: April 2008

OBJECTIVE—Cystatin C–and creatinine-based methods were compared with 99m-technetium-diethylene-triamine-penta-acetic acid (99mTc-DTPA) plasma clearance (isotopic glomerular filtration rate [iGFR]) for detecting declining renal function.

RESEARCH DESIGN AND METHODS—Glomerular filtration rate (GFR) was monitored over a mean of 10.1 years in 85 subjects with type 1 diabetes (with an average of 5.6 measurements per individual). Baseline mean ± SD iGFR of the cohort was 106.1 ± 2.6 ml/min per 1.73 m2. The rates of decline in GFR (ΔGFR) were derived using linear regression.

RESULTS—In 19 of 85 subjects with declining renal function (i.e., ΔiGFR >3.3 ml/min per 1.73 m2 per year), ΔGFR (ml/min per 1.73 m2 per year) was 6.5 by iGFR, 4.2 by 104/creatinine, 3.6 by Cockcroft-Gault formula, 3.4 by the Modification of Diet in Renal Disease (MDRD)-6 equation, and 3.5 by the MDRD-4 variable equation (P < 0.01 vs. iGFR). In comparison, ΔGFR was 6.1 using the formula Cys-GFR = (86.7/cystatin C concentration) − 4.2 (not significant).

CONCLUSIONS—Cystatin C was more accurate in detecting decline in renal function than creatinine-based methods in this population of subjects with type 1 diabetes and a normal mean baseline GFR.
Where Is the Patient in Diabetes Performance Measures?
Authors: Glasgow Russell E. , Peeples Malinda , Skovlund Soren E.
Published: April 2008

OBJECTIVE—Health policies are important determinants of clinician and patient behavior, and an important policy issue is what items are included in healthcare quality and performance measures. There is consensus that patient-centered care and self-management support are essential evidence-based components of good diabetes care. However, most major diabetes performance measures such as the National Committee for Quality Assurance (NCQA)/American Diabetes Association (ADA) Provider Recognition Program indexes have not included self-management or psychosocial items.

RESEARCH DESIGN AND METHODS AND RESULTS—We review the case for and propose a set of patient-centered, self-management indicators to be included as a standard part of diabetes quality indicators. The proposed indicators include: patient self-management goal(s), measures of health behaviors (e.g., healthy eating, medication taking, physical activity, and smoking status), quality of life, and patient-centered collaborative care. We discuss the evidence and the concerns about patient-report measures and summarize successful incorporation of such patient-centered measures in other countries and by the American Association of Diabetes Educators (AADE).

CONCLUSIONS—The adage that “what gets measured, gets done” applies to diabetes management and many other areas of healthcare. Inclusion of the proposed indicators in national diabetes performance measures would be consistent with Institute of Medicine (IOM), ADA, Centers for Disease Control (CDC), Diabetes Attitudes, Wishes, and Needs (DAWN), AADE, and Society of Behavioral Medicine (SBM) recommendations. Such action would enhance both the priority and delivery of quality, patient-centered care, and diabetes self-management support.
Effects of Ramipril and Rosiglitazone on Cardiovascular and Renal Outcomes in People With Impaired Glucose Tolerance or Impaired Fasting Glucose
Authors:   The DREAM Trial Investigators
Published: April 2008

OBJECTIVE—Impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG) are risk factors for diabetes, cardiovascular disease (CVD), and kidney disease. We determined the effects of ramipril and rosiglitazone on combined and individual CVD and renal outcomes in people with IGT and/or IFG in the Diabetes REduction Assessment With ramipril and rosiglitazone Medication (DREAM) trial.

RESEARCH DESIGN AND METHODS—A total of 5,269 people aged ≥30 years, with IGT and/or IFG without known CVD or renal insufficiency, were randomized to 15 mg/day ramipril versus placebo and 8 mg/day rosiglitazone versus placebo. A composite cardiorenal outcome and its CVD and renal components were assessed during the 3-year follow-up.

RESULTS—Compared with placebo, neither ramipril (15.7% [412 of 2,623] vs. 16.0% [424 of 2,646]; hazard ratio [HR] 0.98 [95% CI 0.84–1.13]; P = 0.75) nor rosiglitazone (15.0% [394 of 2,635] vs. 16.8% [442 of 2,634]; 0.87 [0.75–1.01]; P = 0.07) reduced the risk of the cardiorenal composite outcome. Ramipril had no impact on the CVD and renal components. Rosiglitazone increased heart failure (0.53 vs. 0.08%; HR 7.04 [95% CI 1.60–31.0]; P = 0.01) but reduced the risk of the renal component (0.80 [0.68–0.93]; P = 0.005); prevention of diabetes was independently associated with prevention of the renal component (P < 0.001).

CONCLUSIONS—Ramipril did not alter the cardiorenal outcome or its components. Rosiglitazone, which reduced diabetes, also reduced the development of renal disease but not the cardiorenal outcome and increased the risk of heart failure.
Proliferative Diabetic Retinopathy in Type 2 Diabetes Is Related to Coronary Artery Calcium in the Veterans Affairs Diabetes Trial (VADT)
Authors: Reaven Peter D. , Emanuele Nicholas , Moritz Thomas , Klein Ronald , Davis Mathew , Glander Kathy , Duckworth William , Abraira Carlos ,   for the Veterans Affairs Diabetes Trial (VADT)
Published: April 2008

OBJECTIVE—Increasing evidence suggests that macrovascular disease and retinopathy may be more closely linked than previously believed. We determined the relationship between retinopathy and coronary atherosclerosis as measured by computed tomography–detectable coronary artery calcium (CAC).

RESEARCH DESIGN AND METHODS—The cross-sectional association between CAC and retinopathy was assessed on a Veteran Affairs Diabetes Trial subsample of 204 subjects with a mean duration of type 2 diabetes of 12.3 ± 8.3 years.

RESULTS—Retinopathy was correlated with CAC (r = 0.19, P = 0.006). Median CAC increased across retinopathy categories: 197 in those with no retinopathy, 229 in those with microaneurysms only, 364 in those with mild nonproliferative diabetic retinopathy (NPDR), 300 in those with moderate to severe NPDR, and 981 in those with proliferative diabetic retinopathy (PDR). Stepwise multivariable linear regression analysis was performed to find a parsimonious subset of relevant risk factors to include along with PDR in predicting CAC. After adjustment for either this subset of standard factors (P = 0.047) or a more extensive panel of risk factors (P = 0.035), PDR was significantly associated with CAC. Moreover, using logistic regression, individuals with PDR were approximately sixfold more likely to have CAC >400 than those with no PDR, even after adjustment for other CVD risk factors.

CONCLUSIONS—These data indicate an important relationship between retinopathy and extent of CAC and suggest the potential to identify and treat shared risk factors for these common micro- and macrovascular complications.