bluuebunny/crossref_metadata_2025 huggingface dataset:
Catecholaminergic Effects on Ventricular Repolarization During Inhibition of the Rapid Component of the Delayed Rectifier Potassium Current in a Perfused Heart Model
Authors: Overholser Brian R. , Zheng Xiaomei , Tisdale James E.
Published: October 2008

Study Objective. To determine the catecholaminergic effects on the duration of ventricular repolarization during inhibition of the rapid component of the delayed rectifier potassium current (IKr).

Design. Isolated perfused heart model.

Setting. University research center.

Animals. Eighteen male Dunkin‐Hartley guinea pigs.

Intervention. Hearts were excised and perfused in a retrograde manner at a constant aortic pressure of 60 mm Hg and temperature of 37°C. Thirteen hearts were administered sparfloxacin 20 μg/ml (an IKrinhibitor) in a buffered solution; the remaining five hearts were perfused with only the buffered solution to act as controls for potential time‐dependent changes in action potential duration (APD). Immediately after the sparfloxacin infusion, six of the 13 hearts were administered a bolus catecholamine infusion of an epinephrine 10 nM‐norepinephrine 6 nM admixture; 10 minutes after the start of the first catecholamine infusion, these hearts received another bolus infusion of an epinephrine 5 nM‐norepinephrine 3 nM admixture. The other seven hearts were administered only a buffered solution.

Measurements and Main Results. Hearts were paced (240 beats/min), and left ventricular monophasic action potentials were recorded for determination of APD at 90% and 30% repolarization (APD90and APD30, respectively). The APD90and APD30increased in all 13 hearts exposed to sparfloxacin. The mean ± SD APD90increase from baseline at 15 minutes was 4.2 ± 2.5% relative to the five control hearts. In the presence of IKrinhibition, the epinephrine 5 nM‐norepinephrine 3 nM and epinephrine 10 nM‐norepinephrine 6 nM admixtures altered APD90, with a mean ± SD maximum increase in APD90of 3.1 ± 1.2% and 4.5 ± 3.6%, respectively. This corresponded to a statistically significant increase in APD90and APD302 minutes after the catecholamine infusion in the presence of IKrinhibition.

Conclusion. A net prolongation of ventricular repolarization was observed after a catecholamine surge in the presence of mild IKrinhibition. This suggests that counteracting mechanisms may contribute to the apparent arrhythmogenic substrate during nonspecific adrenergic receptor activation in the presence of IKrinhibition.
Dabigatran Etexilate: An Oral Direct Thrombin Inhibitor for Prophylaxis and Treatment of Thromboembolic Diseases
Authors: Baetz Brooke E. , Spinler Sarah A.
Published: October 2008

As the only oral anticoagulation option available in the United States, warfarin use remains widespread. However, concerns of safety remain a substantial issue. Additional anticoagulation options include unfractionated heparin, low‐molecular‐weight heparins (e.g., enoxaparin, dalteparin, and tinzaparin), and the indirect‐acting factor Xa inhibitor, fondaparinux. Direct thrombin inhibitors represent a newer class of anticoagulants used primarily in the treatment of heparin‐induced thrombocytopenia and percutaneous coronary interventions. Three intravenous agents are currently available—lepirudin, bivalirudin, and argatroban—with an oral agent, dabigatran etexilate, undergoing clinical investigation. Dabigatran etexilate offers a rapid onset of action after oral administration, reaching peak plasma concentrations and onset of anticoagulant effect within 0.5–2 hours after administration. Studies have demonstrated linear pharmacokinetics, a linear relationship between ecarin clotting time and international normalized ratio, and no known clinically significant drug or food interactions. Dabigatran etexilate has been studied in clinical trials as prophylaxis for venous thromboembolism in patients undergoing total knee replacement or total hip replacement surgeries, as well as for stroke prevention in patients with atrial fibrillation. Dabigatran etexilate has demonstrated superiority and noninferiority to enoxaparin as prophylaxis for venous thromboembolism in patients undergoing orthopedic surgery, with the most frequent adverse effects being gastrointestinal complaints. Elevations in alanine aminotransferase concentrations were noted in small percentages of patients in both the dabigatran etexilate and enoxaparin groups, with no observed dose association. The overall rates of major bleeding were low, with minor bleeding commonly noted, often at surgical sites. Clinical trials of dabigatran etexilate in patients with atrial fibrillation are ongoing. Results of short‐term efficacy and safety appear promising. Further research is needed regarding long‐term safety and efficacy for other anticoagulation indications.
Nilotinib: A New Tyrosine Kinase Inhibitor for the Treatment of Chronic Myelogenous Leukemia
Authors: Jarkowski Anthony , Sweeney Richard P.
Published: October 2008

Chronic myelogenous leukemia (CML) is a myeloproliferative disorder arising from a single genetic mutation that leads to an increase in immature myeloid cells in the bone marrow and the accumulation of these cells in the blood. Typically, CML represents 15–20% of all adult leukemias, with 4830 new cases expected in 2008. The cytogenetic hallmark of CML is the Philadelphia chromosome, which is the result of the reciprocal translocation and conjugation of the breakpoint cluster region (BCR) gene, BCR, on chromosome 22 and the Abelson (ABL) kinase gene, ABL, on chromosome 9. Current treatment is aimed at inhibiting BCR and ABL kinase with novel agents, the first being imatinib in 2003, and more recently dasatinib in 2006. Nilotinib is a new small‐molecule inhibitor of tyrosine kinase rationally developed from the crystalline structure of the imatinib‐ABL complex. It represents an aminopyrimidine derivative of imatinib with approximately 30 times more potency in vitro against imatinib‐sensitive BCR‐ABL‐expressing cell lines and activity against 32 of 33 point mutations conferring resistance to imatinib. Data from phase I and II studies show that nilotinib has activity against all phases of CML in patients who are intolerant or have failed therapy with imatinib or dasatinib. Nilotinib represents a new therapeutic option for patients with CML who are intolerant or have failed therapy with imatinib. Ongoing clinical trials are assessing nilotinib's role in the treatment of patients with newly diagnosed CML and its long‐term efficacy and safety.
Recombinant Human Erythropoietin Therapy in Critically Ill Jehovah's Witnesses
Authors: Ball Amanda M. , Winstead P. Shane
Published: October 2008

Blood transfusions and blood products are often given as a life‐saving measure in patients with critical illness. However, some patients, such as Jehovah's Witnesses, may refuse their administration due to religious beliefs. Jehovah's Witnesses accept most available medical treatments, but not blood transfusions or blood products due to their religion's interpretation of several passages from the Bible. Since recombinant human erythropoietin (rHuEPO) became available, several cases have been reported in which rHuEPO was successfully administered to critically ill Jehovah's Witnesses. Administration of rHuEPO in combination with other blood conservation techniques has been shown to increase hemoglobin levels and survival in patients who experienced trauma, burns, general surgery, or gastrointestinal hemorrhage. We performed a literature search of the MEDLINE and International Pharmaceutical Abstracts databases of rHuEPO therapy in the Jehovah's Witness population. Fourteen cases were identified in which rHuEPO was administered to Jehovah's Witnesses who required the drug for critical care resuscitation as an alternative to blood products. In each clinical situation, rHuEPO enhanced erythropoiesis; however, time to the start of treatment, dosages, route of administration, and treatment duration varied widely. Supplementation with adjunctive agents, such as iron, folic acid, and vitamin B12, was also beneficial. Use of rHuEPO in Jehovah's Witnesses may provide an alternative to blood transfusions or blood products. Other alternatives, such as hemoglobin‐based oxygen carriers and perfluorocarbons, are also being explored.
Therapeutic Drug Monitoring of Phenytoin in Critically Ill Patients
Authors: von Winckelmann Sandrina L. , Spriet Isabel , Willems Ludo
Published: October 2008

Therapeutic drug monitoring of phenytoin is necessary to ensure therapeutic and nontoxic levels. Hypoalbuminemia, renal failure, and interactions with other highly protein‐bound drugs (e.g., valproic acid) alter protein binding of phenytoin. When these conditions are present, free serum concentrations, which represent the pharmacologically active entity, cannot be predicted from total serum concentrations. Besides general alterations in drug distribution and elimination, protein binding is often altered in critically ill patients. Case reports describe phenytoin toxicity secondary to inappropriate dosage adjustments based solely on total serum concentrations in patients with hypoalbuminemia. Free drug measurements and theoretical equations to facilitate the interpretation of total phenytoin serum levels have been introduced. However, they are not widely implemented in clinical practice because evidence of improvements in patient outcomes is limited. Knowledge of the pharmacokinetic properties of phenytoin is indispensable for correct interpretation of total serum concentrations when protein binding is altered. Free serum concentrations should be measured, or theoretically calculated if measurements are unavailable, to avoid misinterpretation of total serum levels and consequent inappropriate adjustments in the dosage of phenytoin in critically ill patients.
The Cockermouth School Eco Centre, Cumbria, UK
Authors: Pollington S. W.
Published: October 2008

This paper describes the genesis, design and construction of the Mike Wilde Eco Centre at Cockermouth School, Cumbria, UK. This highly unusual multi-functional teaching facility was designed specifically to minimise its environmental impact and to act as a showcase for sustainable design. The paper discusses the choice of different construction materials used and reviews their principal characteristics, along with a number of practical problems faced during design and construction. The more unusual building materials used include recycled brickwork and paving slabs, waste tyres and extensive timber panel construction. The building services and power generation provided are also discussed, as is the success of the project—and the various construction materials used—in terms of achieving its objectives.
Models for teaching sustainable development to children
Authors: Crapper M. , Donald R. , Hill D. , Hall A. , French W.
Published: October 2008

Two models were constructed for use in primary schools to help educate children on the meaning of sustainable development, and more generally on the role of civil engineers. The models shared the same basic structure. One consisted of a river valley, where undeveloped and developed land could be set up and the effects of flooding due to rainfall and river flows investigated. Various types of flood protection could be examined and the effects discussed. The second model allowed a hydropower scheme, with a dam and turbines, to be installed in the river valley. The flow, head and power generated could be varied and the effect on various stakeholders discussed. Both models were accompanied by detailed lesson plans. The models were tested on pupils aged 10 and 11 years from a local primary school. Feedback was good and it was found that in almost all cases the models and associated lessons had improved the children's understanding of sustainable development and the role of civil engineers.
Tilt displacement of caisson breakwater due to wave loading
Authors: ZHANG X.Y. , LEE F.H. , LEUNG C.F.
Published: October 2008

Tilting and overturning of caisson breakwaters due to wave loading is well documented. Although simplified methods of caisson analysis have been proposed, they are either fully elastic analyses that do not account for permanent displacement, or stability analyses that determine whether overturning will occur. In reality, a caisson can incur significant tilt without overturning: such a phenomenon cannot be replicated by either of the above analyses. This paper presents a simplified analysis that takes into account the elastic caisson response as well as the accumulation of permanent tilt with successive wave cycles. Elastic response was simulated using a lump-mass–spring model. Permanent caisson tilt was analysed based on the assumption of the caisson tilting over a circular slip surface beneath its base. A search algorithm was used to determine the radius and depth to the centre of rotation of the critical slip circle. Permanent tilt is generated by the difference between the overturning and stabilising moments during wave peaks. This allows permanent tilt to be accumulated over successive wave peaks. Comparison with centrifuge test data shows that the analysis is able to capture the progressive build-up of tilt reasonably well. Furthermore, comparison with a field case of caisson failure during a storm shows good correlation, although uncertainty over the number of wave cycles precludes a more direct comparison.
Small‐Mammal Microhabitat Associations and Response to Grazing in Oregon
Authors: JOHNSTON AARON N. , ANTHONY ROBERT G.
Published: October 2008

Abstract: Livestock grazing is common and widespread throughout North America, yet few studies have evaluated its effects on small mammals. We studied small mammals in mixed‐conifer forests and oak woodlands on the Cascade‐Siskiyou National Monument in southern Oregon, USA, to 1) evaluate small‐mammal microhabitat associations, 2) identify riparian‐associated species, and 3) test the hypothesis that grazing does not influence small mammals after accounting for microhabitat associations. We live‐trapped small mammals at 16 study sites and used logistic regression to model probability of capture on measured habitat characteristics at each trap station and to evaluate effects of grazing. Over 2 years, we trapped 1,270 individual small mammals representing 18 species. Odds of capturing western harvest mice (Reithrodontomys megalotis), dusky‐footed woodrats (Neotoma fuscipes), and long‐tailed voles (Microtus longicaudus) were lower (P < 0.05) on heavily versus lightly grazed sites. Odds of capture for deer mice (Peromyscus maniculatus) were lower (P < 0.05) on heavily versus lightly grazed sites in woodlands, but there was less difference in the odds of capture between grazing intensities in conifer forests. Odds of capturing Townsend's vole (Microtus townsendii) were lower on heavily versus lightly grazed riparian areas. Western harvest mice, long‐tailed voles, and Townsend's voles were associated with, but not obligated to, riparian areas. Deer mice were ubiquitous, but captures were also higher (P < 0.05) in riparian areas compared with uplands. Siskiyou chipmunks (Tamias siskiyou) and piñon mice (Peromyscus truei) were associated with uplands (P < 0.05) rather than riparian areas. Trowbridge's shrews (Sorex trowbridgii), Siskiyou chipmunks, and bushy‐tailed woodrats (Neotoma cinerea) were positively associated with coarse woody debris. Land managers should anticipate that small mammals associated with herbaceous or shrub cover, particularly in riparian areas, will decline when cattle remove this cover.
Small Mammal Mycophagy Response to Variations in Green‐Tree Retention
Authors: JACOBS KATHERINE M. , LUOMA DANIEL L.
Published: October 2008

Abstract: We studied the effects of 6 green‐tree retention levels and patterns on the diets of northern flying squirrels (Glaucomys sabrinus), Townsend's chipmunks (Tamias townsendii), Siskiyou chipmunks (T. siskiyou), western red‐backed voles (Myodes californicus), and southern red‐backed voles (Myodes gapperi) using fecal pellet analysis. These rodents are truffle spore dispersers and prey for forest predators such as the northern spotted owl (Strix occidentalis caurina). Pretreatment diets showed differences in truffle and plant consumption among genera. Tree harvesting, especially in the 15% aggregated retention pattern, reduced frequency of Rhizopogon spores in the diet of voles, which may reflect a reduced ability of these animals to forage for Rhizopogon truffles, a decreased access to these truffles, or a reduction in Rhizopogon truffle abundance or frequency. Habitat island effects and edge effects provide conceptual frameworks for the reduction in consumption of Rhizopogon truffles by voles in green‐tree aggregates. Overall, small mammal consumption of truffles showed little change in response to the treatments. Animals may be compensating for a locally declining food source by altering their foraging behavior. The long‐term effect of this postulated behavioral compensation on small mammal energetics and population dynamics is unknown. Forest managers may reduce the impact of tree harvesting on these key forest ecosystem components by including green‐tree aggregates within a dispersed retention matrix.
Factors Influencing Nesting Success of King Eiders on Northern Alaska's Coastal Plain
Authors: BENTZEN REBECCA L. , POWELL ABBY N. , SUYDAM ROBERT S.
Published: October 2008

Abstract:King eider (Somateria spectabilis) populations have declined markedly in recent decades for unknown reasons. Nest survival is one component of recruitment, and a female's chance of reproductive success increases with her ability to choose an appropriate nesting strategy. We estimated variation in daily nest survival of king eiders at 2 sites, Teshekpuk and Kuparuk, Alaska, USA, 2002–2005. We evaluated both a priori and exploratory competing models of nest survival that considered importance of nest concealment, seclusion, and incubation constancy as strategies to avoid 2 primary egg predators, avian (Larusspp.,Stercorariusspp., andCorvus corax) and fox (Alopex lagopus). We used generalized nonlinear techniques to examine factors affecting nest survival rates and information‐theoretic approaches to select among competing models. Estimated nest survival, accounting for a nest visitation effect, varied considerably across sites and years (0.21–0.57); however, given our small sample size, much of this variation may be attributable to sampling variation (s̀2process= 0.007, 95% CI: 0.003–0.070). Nest survival was higher at Kuparuk than Teshekpuk in all years; however, due to the correlative nature of our data, we cannot determine the underlying causes with any certainty. We found mixed support for the concealed breeding strategy; females derived no benefit from nesting in areas with more willow (Salixspp.; measure of concealment) except that the observer effect diminished as willow cover increased. We suggest these patterns are due to conflicting predation pressures. Nest survival was not higher on islands (measure of seclusion) or with increased incubation constancy but was higher post‐fox removal, indicating that predator control on breeding grounds could be a viable management option. Nest survival was negatively affected by our nest visitations, most likely by exposing the nest to avian scavengers. We recommend precautions be taken to limit the effects of nest visits in future studies and to consider them as a possible negative bias in estimated nest survival. Future models of the impacts of development within the breeding grounds of king eider should consider the influence of humans in the vicinity of nests.
Spatiotemporal Distribution of Black Bear‐Human Conflicts in Colorado, USA
Authors: BARUCH‐MORDO SHARON , BRECK STEWART W. , WILSON KENNETH R. , THEOBALD DAVID M.
Published: October 2008

Abstract: Management and conservation of large carnivores increasingly includes conflicts with humans. Consequently, a greater understanding of spatiotemporal trends of conflicts is needed to efficiently allocate resources and apply targeted management. Therefore, we examined spatial and temporal distribution of American black bear (Ursus americanus; hereafter, bear)‐human conflicts in Colorado, USA, related to 3 conflict types (agriculture operations, human development, and road kills). We used the Getis‐Ord Gi* spatial clustering statistic to describe location and assess magnitude of bear‐human conflicts in Colorado during 1986–2003 and investigated temporal trends of bear‐human conflicts by type. Bear‐human conflicts showed distinct spatial clustering by type, and areas of high clustering overlapped conflict types. Clustering for agriculture operations conflicts had the largest overall Gi* value and overlapped counties with high sheep production. Both human development and road‐kill conflict clusters were high in areas of high‐quality oak (Quercus spp.)—shrub habitat in the central and southern portions of Colorado's Front Range region and near the city of Durango in southwestern Colorado. Bear‐human conflicts varied by year and type but overall increased during the 18 years. Summed across years, most conflicts were related to agriculture (32%), followed by road kills (27%) and human development (24%). The greatest proportion of agriculture operations‐related conflicts (76%), human development‐related conflicts (36%), and road kills (47%) occurred in 1988, 1999, and 2003, respectively. Considering that bear‐human conflicts in Colorado increased over time and will likely continue to increase, we suggest wildlife managers improve data collection by obtaining detailed location data, categorizing conflict types uniformly, and applying conflict regulations consistently to strengthen inference of similar analyses. We also suggest that managers target efforts to mitigate damage by focusing on areas with high clustering of conflicts.
Effects of Natural Barriers and Habitat on the Western Spread of Raccoon Rabies in Alabama
Authors: ARJO WENDY M. , FISHER CHRISTINE E. , ARMSTRONG JAMES , BOYD FRANK , SLATE DENNIS
Published: October 2008

Abstract:Although domestic animal transmission of rabies has largely been mitigated, the disease remains a concern in both Europe and North America where wildlife transmission has caused epizootics. Raccoon (Procyon lotor) rabies was established in Alabama, USA, in 1975, primarily in the southeastern corner of the state. However, with the exception of isolated events, rabies has not continued to spread westward across the Alabama River. We monitored movements of 100 radiocollared raccoons on 2 sites within hardwood and agriculture habitats in a rabies enzootic area east of the Alabama River, in managed pine habitat area west of the river where rabies sporadically occurs, and in a mixed pine hardwood area outside of the known rabies enzootic area to determine if raccoon movements and habitat use in certain habitat types and the presence of a river may serve as natural barriers preventing the western spread of rabies in Alabama. We also examined raccoon contact rates to determine if they influence disease transmission through static and dynamic interactions. Raccoons in mixed pine‐hardwood forest habitats had smaller home ranges and less overlap of ranges compared to the other 3 habitats. However, static interactions between habitats in the use of overlap areas did not differ (F11,129= 1.63,P= 0.09). Rabies antibody titers were highest in the managed pine habitat (28%) even prior to oral vaccine bait distributions in spring of 2004 and 2005. Biomarker data from radiocollared and additional raccoons captured after the bait distribution west of the Alabama River demonstrated a low efficacy of the vaccine reaching the small southern raccoons. The combination of the river as a partial barrier, the high percentage of pine forested habitat west of the river, and limited spatial movements of raccoons within these forested habitats appears to have reduced the likelihood of rabies establishing west of the river. Understanding different host‐habitat‐ disease systems is important for successful management of diseases. Based on our results, we recommend that the oral vaccine program continue to use the Alabama River as a partial barrier and baiting be concentrated in the fragmented bottomland hardwood forests and around larger bodies of water where raccoon densities are highest. Success of baiting strategies designed to take advantage of northern raccoon dynamics and habitat use may not be applicable to southern populations.
Merriam's Turkey Nest Survival and Factors Affecting Nest Predation by Mammals
Authors: LEHMAN CHAD P. , RUMBLE MARK A. , FLAKE LESTER D. , THOMPSON DANIEL J.
Published: October 2008

Abstract:Nest success is an important parameter affecting population fluctuations of wild turkeys (Meleagris gallopavo). Factors influencing mammalian predation on turkey nests are complicated and not well understood. Therefore, we assessed nest hazard risk by testing competing hypotheses of Merriam's turkey (M. g. merriami) nest survival in a ponderosa pine (Pinus ponderosa) ecosystem during 2001–2003. We collected nesting information on 83 female Merriam's turkeys; annual nest success averaged 50% for adult females (range = 45–59%) and 83% for yearling females (range = 75–100%). Proportional hazard modeling indicated that precipitation increased the hazard of nest mortality. However, estimated hazard of nest predation was lowered when incubating females had greater shrub cover and visual obstruction around nests. Coyotes (Canis latrans) were the primary predator on turkey nests. We hypothesize that precipitation is the best predictor of nest survival for first nests because coyotes use olfaction effectively to find nesting females during wet periods. Temporally, as the nesting season progressed, precipitation declined and vegetation cover increased and coyotes may have more difficulty detecting nests under these conditions later in the nesting period. The interaction of concealment cover with precipitation indicated that nest hazard risk from daily precipitation was reduced with greater shrub cover. Management activities that promote greater shrub cover may partially offset the negative effects of greater precipitation events.
Male Seminole Bat Winter Roost‐Site Selection in a Managed Forest
Authors: HEIN CRIS D. , CASTLEBERRY STEVEN B. , MILLER KARL V.
Published: October 2008

Abstract: Understanding year‐round roost‐site selection is essential for managing forest bat populations. From January to March, 2004 to 2006, we used radiotelemetry to investigate winter roost‐site selection by Seminole bats (Lasiurus seminolus) on an intensively managed landscape with forested corridors in southeastern South Carolina, USA. We modeled roost‐site selection with logistic regression and used Akaike's Information Criterion for small samples (AICc) and Akaike weights to select models relating roost‐site selection to plot‐ and landscape‐level variables. We tracked 20 adult male bats to 71 individual roosts. Bats used a variety of roosting structures, including the canopy of overstory trees, understory vegetation, pine (Pinus spp.) needle clusters, and leaf litter. Roost height, structure type, and habitat type were influenced by changes in minimum nightly temperature. On warmer nights, bats selected taller trees in mature forest stands, but when minimum nightly temperatures were <4° C, bats typically were found roosting on or near the forest floor in mid‐rotation stands. We recommend avoiding prescribed burning in mid‐rotation stands on days when the previous night's temperature is <4 °C to minimize potential disturbance and direct mortality of bats roosting on or near the forest floor. We encourage forest managers to incorporate seasonal changes in roost‐site selection to create year‐round management strategies for forest bats in managed landscapes.
Assessing Landbird Monitoring Programs and Demographic Causes of Population Trends
Authors: SARACCO JAMES F. , DESANTE DAVID F. , KASCHUBE DANIELLE R.
Published: October 2008

Abstract:Population trend data from the North American Breeding Bird Survey (BBS) have been used to identify conservation priorities and justify major conservation initiatives. Yet the BBS has been criticized for potential habitat bias and reliance on abundance indices to estimate trends. We compared 1992–2003 BBS trend estimates to trend estimates derived from bird‐banding data collected as part of the Monitoring Avian Productivity and Survivorship (MAPS) program for 36 wood warbler species. Similarity in trends between the 2 monitoring programs at the survey‐wide and program‐wide scales suggested that each program can provide accurate trend information. The MAPS program, however, was designed primarily to complement (rather than duplicate) count‐based efforts, such as the BBS, by providing estimates or indices of demographic rates. Demographic data from MAPS can be used to lend insight into proximate (demographic) causes of population trends and inform management. We illustrate this with analyses of 1992–2003 MAPS data for yellow warbler (Dendroica petechia). We used reverse‐time capture‐recapture models to evaluate importance of new recruits (including immigrating adults and young from the previous year) relative to surviving adults in explaining variation in trend among BBS physiographic strata. We included the number of young per adult captured (an index of productivity) as a covariate in models to assess effects of productivity on trends. Survival was the key demographic driver of recent population trends. Comparison of MAPS productivity indices and adult apparent survival rate estimates to BBS trend estimates largely confirmed this inference. We suggest that increased MAPS coverage, better coordination between MAPS and the BBS, and continued development of analytical methods that link the 2 programs will enhance the value of these monitoring efforts to land managers and conservation planners working at a variety of spatial scales.
Comparison of Methods for Estimating Bird Abundance and Trends From Historical Count Data
Authors: THOMPSON FRANK R. , LA SORTE FRANK A.
Published: October 2008

Abstract: The use of bird counts as indices has come under increasing scrutiny because assumptions concerning detection probabilities may not be met, but there also seems to be some resistance to use of model‐based approaches to estimating abundance. We used data from the United States Forest Service, Southern Region bird monitoring program to compare several common approaches for estimating annual abundance or indices and population trends from point‐count data. We compared indices of abundance estimated as annual means of counts and from a mixed‐Poisson model to abundance estimates from a count‐removal model with 3 time intervals and a distance model with 3 distance bands. We compared trend estimates calculated from an autoregressive, exponential model fit to annual abundance estimates from the above methods and also by estimating trend directly by treating year as a continuous covariate in the mixed‐Poisson model. We produced estimates for 6 forest songbirds based on an average of 621 and 459 points in 2 physiographic areas from 1997 to 2004. There was strong evidence that detection probabilities varied among species and years. Nevertheless, there was good overall agreement across trend estimates from the 5 methods for 9 of 12 comparisons. In 3 of 12 comparisons, however, patterns in detection probabilities potentially confounded interpretation of uncorrected counts. Estimates of detection probabilities differed greatly between removal and distance models, likely because the methods estimated different components of detection probability and the data collection was not optimally designed for either method. Given that detection probabilities often vary among species, years, and observers investigators should address detection probability in their surveys, whether it be by estimation of probability of detection and abundance, estimation of effects of key covariates when modeling count as an index of abundance, or through design‐based methods to standardize these effects.
Monitoring in the Context of Structured Decision‐Making and Adaptive Management
Authors: LYONS JAMES E. , RUNGE MICHAEL C. , LASKOWSKI HAROLD P. , KENDALL WILLIAM L.
Published: October 2008

Abstract: In a natural resource management setting, monitoring is a crucial component of an informed process for making decisions, and monitoring design should be driven by the decision context and associated uncertainties. Monitoring itself can play ≥3 roles. First, it is important for state‐dependent decision‐making, as when managers need to know the system state before deciding on the appropriate course of action during the ensuing management cycle. Second, monitoring is critical for evaluating the effectiveness of management actions relative to objectives. Third, in an adaptive management setting, monitoring provides the feedback loop for learning about the system; learning is sought not for its own sake but primarily to better achieve management objectives. In this case, monitoring should be designed to reduce the critical uncertainties in models of the managed system. The United States Geological Survey and United States Fish and Wildlife Service are conducting a large‐scale management experiment on 23 National Wildlife Refuges across the Northeast and Midwest Regions. The primary management objective is to provide habitat for migratory waterbirds, particularly during migration, using water‐level manipulations in managed wetlands. Key uncertainties are related to the potential trade‐offs created by management for a specific waterbird guild (e.g., migratory shorebirds) and the response of waterbirds, plant communities, and invertebrates to specific experimental hydroperiods. We reviewed the monitoring program associated with this study, and the ways that specific observations fill ≥1 of the roles identified above. We used observations from our monitoring to improve state‐dependent decisions to control undesired plants, to evaluate management performance relative to shallow‐water habitat objectives, and to evaluate potential trade‐offs between waterfowl and shorebird habitat management. With limited staff and budgets, management agencies need efficient monitoring programs that are used for decision‐making, not comprehensive studies that elucidate all manner of ecological relationships.
β-Cell Mass and Type 1 Diabetes
Authors: Akirav Eitan , Kushner Jake A. , Herold Kevan C.
Published: October 2008

OBJECTIVE— β-Cell regeneration is a fundamental but elusive goal for type 1 diabetes research. Our objective is to review newer human and animal studies of β-cell destruction and regeneration and consider the implications for treatment of type 1 diabetes.

RESEARCH DESIGN AND METHODS— Recent human and animal studies of β-cell destruction and regeneration in type 1 diabetes are reviewed.

RESULTS— The loss of β-cells that characterizes type 1 diabetes reflects the net effects of destruction and regeneration. These processes have been examined in the nonobese diabetic (NOD) mouse; uncertainty remains about β-cell dynamics in humans. Islet inflammation stimulates β-cell replication that produces new insulin-positive cells. The regenerative process may tide the loss of overall β-cell function, but it also may enhance the autoimmune attack on β-cells by providing new epitopes. The highest rates of β-cell replication are at the time of diagnosis of diabetes in NOD mice, and if autoimmunity and islet inflammation are arrested, new β-cells are formed. However, the majority of β-cells after treatment with immune modulators such as anti-CD3 monoclonal antibody, and most likely during the “honeymoon” in human disease, are recovered β-cells that had been degranulated but present at the time of diagnosis of diabetes.

CONCLUSIONS— Residual β-cells play a significant role for the design of therapeutic trials: they not only may respond to combination therapies that include stimulants of metabolic function but are also the potential source of new β-cells.
Effects of High-Dose Simvastatin Therapy on Glucose Metabolism and Ectopic Lipid Deposition in Nonobese Type 2 Diabetic Patients
Authors: Szendroedi Julia , Anderwald Christian , Krssak Martin , Bayerle-Eder Michaela , Esterbauer Harald , Pfeiler Georg , Brehm Attila , Nowotny Peter , Hofer Astrid , Waldhäusl Werner , Roden Michael
Published: October 2008

OBJECTIVE—Statins may exert pleiotropic effects on insulin action that are still controversial. We assessed effects of high-dose simvastatin therapy on peripheral and hepatic insulin sensitivity, as well as on ectopic lipid deposition in patients with hypercholesterolemia and type 2 diabetes.

RESEARCH DESIGN AND METHODS—We performed a randomized, double-blind, placebo-controlled, single-center study. Twenty patients with type 2 diabetes received 80 mg simvastatin (BMI 29 ± 4 kg/m2, age 55 ± 6 years) or placebo (BMI 27 ± 4 kg/m2, age 58 ± 8 years) daily for 8 weeks and were compared with 10 healthy humans (control subjects; BMI 27 ± 4 kg/m2, age 55 ± 7 years). Euglycemic-hyperinsulinemic clamp tests combined with d-[6,6-d2]glucose infusion were used to assess insulin sensitivity (M) and endogenous glucose production (EGP). 1H magnetic resonance spectroscopy was used to quantify intramyocellular and hepatocellular lipids.

RESULTS—High-dose simvastatin treatment lowered plasma total and LDL cholesterol levels by ∼33 and ∼48% (P < 0.005) but did not affect M, intracellular lipid deposition in soleus and tibialis anterior muscles and liver, or basal and insulin-suppressed EGP. In simvastatin-treated patients, changes in LDL cholesterol related negatively to changes in M (r = −0.796, P < 0.01). Changes in fasting free fatty acids (FFAs) related negatively to changes in M (r = −0.840, P < 0.01) and positively to plasma retinol-binding protein-4 (r = 0.782, P = 0.008).

CONCLUSIONS—High-dose simvastatin treatment has no direct effects on whole-body or tissue-specific insulin action and ectopic lipid deposition. A reduction in plasma FFAs probably mediates alterations in insulin sensitivity in vivo.
Prevalence of Pre-Diabetes and Its Association With Clustering of Cardiometabolic Risk Factors and Hyperinsulinemia Among U.S. Adolescents
Authors: Li Chaoyang , Ford Earl S. , Zhao Guixiang , Mokdad Ali H.
Published: October 2008

OBJECTIVE—Impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) are considered to constitute “pre-diabetes.” We estimated the prevalence of IFG, IGT, and pre-diabetes among U.S. adolescents using data from a nationally representative sample.

RESEARCH DESIGN AND METHODS—We analyzed data from participants aged 12–19 years in the National Health and Nutrition Examination Survey 2005–2006. We used fasting plasma glucose and 2-h glucose during an oral glucose tolerance test to assess the prevalence of IFG, IGT, and pre-diabetes and used the log-binomial model to estimate the prevalence ratios (PRs) and 95% CIs.

RESULTS—The unadjusted prevalences of IFG, IGT, and pre-diabetes were 13.1, 3.4, and 16.1%, respectively. Boys had a 2.4-fold higher prevalence of pre-diabetes than girls (95% CI 1.3–4.3). Non-Hispanic blacks had a lower rate than non-Hispanic whites (PR 0.6, 95% CI 0.4–0.9). Adolescents aged 16–19 years had a lower rate than those aged 12–15 years (0.6, 0.4–0.9). Overweight adolescents had a 2.6-fold higher rate than those with normal weight (1.3–5.1). Adolescents with two or more cardiometabolic risk factors had a 2.7-fold higher rate than those with none (1.5–4.8). Adolescents with hyperinsulinemia had a fourfold higher prevalence (2.2–7.4) than those without. Neither overweight nor number of cardiometabolic risk factors was significantly associated with pre-diabetes after adjustment for hyperinsulinemia.

CONCLUSIONS—Pre-diabetes was highly prevalent among adolescents. Hyperinsulinemia was independently associated with pre-diabetes and may account for the association of overweight and clustering of cardiometabolic risk factors with pre-diabetes.
YKL-40, a Marker of Inflammation and Endothelial Dysfunction, Is Elevated in Patients With Type 1 Diabetes and Increases With Levels of Albuminuria
Authors: Rathcke Camilla Noelle , Persson Frederik , Tarnow Lise , Rossing Peter , Vestergaard Henrik
Published: October 2008

OBJECTIVE—The inflammation marker YKL-40 is elevated in patients with type 2 diabetes and is associated with atherosclerosis and increased cardiovascular mortality. In the present study, YKL-40 levels were examined in patients with type 1 diabetes with increasing levels of albuminuria, known to be associated with an increased risk of cardiovascular disease.

RESEARCH DESIGN AND METHODS—A total of 149 patients with type 1 diabetes attending Steno Diabetes Center were examined: 58 had normoalbuminuria (urinary albumin excretion rate <30 mg/24 h), 46 had persistent microalbuminuria (urinary albumin excretion rate 30–300 mg/24 h), and 45 had persistent macroalbuminuria/diabetic nephropathy (urinary albumin excretion rate >300 mg/24 h). The control group consisted of 55 healthy individuals. Groups were matched according to sex and duration of diabetes (>30 years).

RESULTS—Median levels [interquartile range] of serum YKL-40 were significantly higher in normoalbuminuria versus control (37 [29–52] vs. 53 [32–105] ng/ml, P < 0.01) and were increasing with increasing levels of albuminuria (microalbuminuria 74 [45–160] ng/ml and diabetic nephropathy 117 [68–215] ng/ml; P < 0.001 for all comparisons). YKL-40 levels correlated with the urinary albumin-to-creatinine ratio in the total group of participants (r2 = 0.25, P < 0.001). Significant but weak intercorrelations of YKL-40 were found with age, diastolic blood pressure, A1C, and serum creatinine. After adjustment for significant covariates, albuminuria was significantly associated with YKL-40 levels (P < 0.001).

CONCLUSIONS—YKL-40 levels are elevated in patients with type 1 diabetes with an independent association between increasing YKL-40 levels and increasing levels of albuminuria. The present study is the first to suggest a role of YKL-40 in the gradually progressing vascular complications in patients with type 1 diabetes.
Oral Disposition Index Predicts the Development of Future Diabetes Above and Beyond Fasting and 2-h Glucose Levels
Authors: Utzschneider Kristina M. , Prigeon Ronald L. , Faulenbach Mirjam V. , Tong Jenny , Carr Darcy B. , Boyko Edward J. , Leonetti Donna L. , McNeely Marguerite J. , Fujimoto Wilfred Y. , Kahn Steven E.
Published: October 2008

OBJECTIVE—We sought to determine whether an oral disposition index (DIO) predicts the development of diabetes over a 10-year period. First, we assessed the validity of the DIO by demonstrating that a hyperbolic relationship exists between oral indexes of insulin sensitivity and β-cell function.

RESEARCH DESIGN AND METHODS—A total of 613 Japanese-American subjects (322 men and 291 women) underwent a 75-g oral glucose tolerance test (OGTT) at baseline, 5 years, and 10 years. Insulin sensitivity was estimated as 1/fasting insulin or homeostasis model assessment of insulin sensitivity (HOMA-S). Insulin response was estimated as the change in insulin divided by change in glucose from 0 to 30 min (ΔI0–30/ΔG0–30).

RESULTS—ΔI0–30/ΔG0–30 demonstrated a curvilinear relationship with 1/fasting insulin and HOMA-S with a left and downward shift as glucose tolerance deteriorated. The confidence limits for the slope of the loge-transformed estimates included −1 for ΔI0–30/ΔG0–30 versus 1/fasting insulin for all glucose tolerance groups, consistent with a hyperbolic relationship. When HOMA-S was used as the insulin sensitivity measure, the confidence limits for the slope included −1 only for subjects with normal glucose tolerance (NGT) or impaired fasting glucose (IFG)/impaired glucose tolerance (IGT) but not diabetes. On the basis of this hyperbolic relationship, the product of ΔI0–30/ΔG0–30 and 1/fasting insulin was calculated (DIO) and decreased from NGT to IFG/IGT to diabetes (P < 0.001). Among nondiabetic subjects at baseline, baseline DIO predicted cumulative diabetes at 10 years (P < 0.001) independent of age, sex, BMI, family history of diabetes, and baseline fasting and 2-h glucose concentrations.

CONCLUSIONS—The DIO provides a measure of β-cell function adjusted for insulin sensitivity and is predictive of development of diabetes over 10 years.
Average entanglement of spin 1 and 1/2 pair
Authors: Zhu Guo-Qiang
Published: October 2008

We study the entanglement features of the ground state of a system composed of spin 1 and 1/2 parts. In the light of the ground state degeneracy, the notion of average entanglement is used to measure the entanglement of the Hilbert subspace. The entanglement properties of both a general superposition as well as the mixture of the degenerate ground states are discussed by means of average entanglement and the negativity respectively.
Anti-Inflammatory Effects of Thyme Essential Oil in Mice
Authors: Juhas Š. , Bujňáková D. , Rehák P. , Čikoš Š. , Czikková S. , Veselá J. , Iłková G. , Koppel J.
Published: October 2008

Plant essential oils are plant secondary metabolites possessing various pharmacological properties, primarily anti-oxidative, antimicrobial or immunomodulatory ones. The aim of this work was to study the effects of thyme essential oil dietary administration in murine DTH/ CHS reaction, carrageenan paw oedema and TNBS colitis. Thyme essential oil was added to the murine diet at three concentrations (5000, 2500 and 1250 ppm) and fed to Balb/c mice. The extent of ear swelling in DTH/CHS reaction and paw oedema induced by carrageenan application was measured using the Mitutoyo thickness gauge. In the model of TNBS colitis we evaluated the changes in body weight, the colon weight : body weight ratio, bacterial translocation to mesenteric lymph nodes, and macroscopical and histological scores. IL-1β and IL-6 messenger RNA expression in colonic samples of one experimental group were assessed using quantitative real-time reverse transcriptase PCR. Dietary supplementation with 5000 ppm of thyme essential oil significantly decreased paw oedema and ear swelling. This thyme essential oil concentration caused a significant inhibition of total mRNA IL-1β expression in the mouse colon, and markedly decreased the macroscopic and microscopic scores of colitis. On the other hand, the 1250 ppm of thyme essential oil in diet increased ear oedema induced by oxazolone application in mice. Our study indicates that thyme essential oil is able to affect murine experimental inflammatory models depending on the concentration used. It is concluded that the anti-inflammatory effects of thyme essential oil should be interpreted with a caution due to its contradictory, dose-related effects.
Activities of Antioxidant and Detoxifying Enzymes in Rats after Lead Exposure
Authors: Alghazal M. A. , Lenártová V. , Holovská K. , Sobeková A. , Falis M. , Legáth J.
Published: October 2008

The studies were undertaken to investigate the activity response of the antioxidant enzyme superoxide dismutase (SOD) and detoxifying enzyme glutathione-S-transferase (GST) of rats exposed to lead. Enzyme activities were determined in the liver, kidneys and heart of male and female rats that received 100 mg and 1000 mg of lead acetate per litre, respectively, in their drinking water for 18 weeks. Statistical analyses indicated differences related to the organs and to the sex of animals. Administration of lead evoked an increase of the SOD activity in the liver and kidneys both in male and female rats but only in the heart of female rats. GST activity decreased in the liver and heart of male rats, while this activity increased in the liver and heart of female rats. In kidneys, the lower lead dose resulted in a decrease of the GST activity in both groups but the higher dose evoked an increase of activity only in male rats. Thiobarbituric acid reactive substances (TBARS), an indicator of oxidative stress, significantly increased in rats that were given the high lead dose, in the kidneys of male rats and in the heart of female rats. Most probably, the observed changes could be a compensatory response to different lead accumulation in the male and female organs and also the possible distinct mechanisms in ROS elimination.