bluuebunny/crossref_metadata_2025 huggingface dataset:
Residual effect of clover-rich leys on soil nitrogen and successive grain crops
Authors: NYKÄNEN A. , GRANSTEDT A. , JAUHIAINEN L.
Published: April 2008

Legume-based leys form the basis for crop rotations in organic farming as they fix nitrogen (N) from the atmosphere for the succeeding crops. The age, yield, C:N, biological N fixation (BNF) and total N of red clover-grass leys were studied for their influence on yields, N uptake and N use efficiency (NUE) of the two sequential cereal crops planted after the leys. Mineral N in deeper soil (30-90 cm) was measured to determine N leaching risk. Altogether, four field experiments were carried out in 1994-1998 at two sites. The age of the ley had no significant effect on the yields and N uptake of the two subsequent cereals. Surprisingly, the residual effect of the leys was negligible, at 020 kg N ha-1yr-1. On the other hand, the yield and C:N of previous red clover-grass leys, as well as BNF-N and total-N incorporated into the soil influenced subsequent cereals. NUEs of cereals after ley incorporation were rather high, varying from 30% to 80%. This might indicate that other factors, such as competition from weeds, prevented maximal growth of cereals. The mineral N content deeper in the soil was mostly below 10 kg ha-1 in the sandy soil of Juva, but was 5-25 kg ha-1 in clayey soil of Mietoinen.;
Predictive Model of Habitat Suitability for the Marbled Murrelet in Western Washington
Authors: HAMER THOMAS E. , VARLAND DANIEL E. , MCDONALD TRENT L. , MEEKINS DOUGLAS
Published: April 2008

Abstract: The marbled murrelet (Brachyramphus marmoratus) is a small Pacific seabird with a breeding range that extends from the Aleutian Islands to central California. Throughout most of its breeding range, it uses mature and old‐growth coniferous forests as nesting habitat. Although most murrelets seem to nest within 60 km of the coast, occupied nesting habitat has been identified as far as 84 km from the ocean in Washington state. Due to the extensive inland distances within which birds are known to breed, the area requiring surveys to identify breeding sites can be enormous. Therefore, the standard 2‐year survey protocol can be expensive and time‐consuming for forest management agencies and companies to administer. We developed a logistic regression model to determine whether a suite of forest structural characteristics could be used to reliably predict occupancy of a forest patch by marbled murrelets. We tested the performance of the final model using cross‐validation procedures and a sample of independent sites. We used 50 sites surveyed for marbled murrelets to estimate the model, and 48 independent sites were available to test model performance. All 50 sites were on private forestland owned by Rayonier located in the western lowlands of Olympic Peninsula within the Sitka spruce and western hemlock transition zones. We sampled forest habitat at each site, and we collected information on 15 explanatory variables. The best‐fitting logistic regression model contained variables that measured number of canopy layers (P<0.001, approx. F test) and mistletoe (Arceuthobium sp.) abundance (P = 0.031, approx. F test). The model misclassified 2 of 33 (94% correct) unoccupied sites as occupied using a classification cut‐off (c) of c=0.25. In the other direction, under cross‐validation the final model misclassified 2 of 17 (88% correct) occupied sites as unoccupied. On a test of the model against an independent sample, using a classification cut‐off value of c = 0.25, the final model correctly classified 36 of 48 sites (75% correct). The final model misclassified 3 of 31 occupied sites as unoccupied (90% correct). Use of predictive models could greatly reduce the amount of forest that requires surveys by screening out those sites with little probability of use and by focusing remaining effort on higher probability sites, resulting in a higher likelihood of identifying occupied sites and thereby more efficiently conserving marbled murrelet nesting habitat.
Associations Among Breeding Birds and Gambel Oak in Southwestern Ponderosa Pine Forests
Authors: JENTSCH STEPHANIE , MANNAN R. WILLIAM , DICKSON BRETT G. , BLOCK WILLIAM M.
Published: April 2008

Abstract: Ponderosa pine (Pinus ponderosa) forests with Gambel oak (Quercus gambelii) are associated with higher bird abundance and diversity than are ponderosa pine forests lacking Gambel oak. Little is known, however, about specific structural characteristics of Gambel oak trees, clumps, and stands that may be important to birds in ponderosa pine‐Gambel oak (hereafter pine‐oak) forests. We examined associations among breeding birds and structural characteristics of Gambel oak at a scale similar in size to individual bird territories in pine‐oak forests in northern Arizona and western New Mexico, USA. Avian species richness and occurrence of some bird species were associated with specific growth forms of Gambel oak. Estimated probability of Virginia's warblers (Vermivora virginiae), black‐headed grosbeaks (Pheucticus melanocephalus), and red‐faced warblers (Cardellina rubrifrons) occurring at points increased with increasing density of pole‐sized Gambel oak 7–15 cm in diameter at breast height. We also found evidence that large Gambel oak trees (≥23 cm dbh) were associated with increased occurrence of yellow‐rumped warblers (Dendroica coronata) at points. Some avian associations with oak were influenced by characteristics of ponderosa pines. For example, bird species richness was positively associated with the abundance of large Gambel oak when density of large pine trees ≥23 cm in diameter at breast height was low. Because large oak trees are rare and their numbers are thought to be declining, efforts should be made to retain and promote growth of additional oaks in this size class. Forest management practices that maintain forest openings, such as prescribed burning, could promote growth of pole‐sized Gambel oak, which appears important to some bird species in pine‐oak forests.
Determining Sustainable Levels of Cumulative Effects for Boreal Caribou
Authors: SORENSEN TROY , MCLOUGHLIN PHILIP D. , HERVIEUX DAVE , DZUS ELSTON , NOLAN JACK , WYNES BOB , BOUTIN STAN
Published: April 2008

Abstract: Direct and indirect effects of industrial development have contributed, in part, to the threatened status of boreal ecotype caribou (Rangifer tarandus caribou) in Alberta and Canada. Our goal was to develop a model that would allow managers to identify landscape‐scale targets for industrial development, while ensuring functional habitat for sustainable caribou populations. We examined the relationship between functional habitat loss resulting from cumulative effects of natural and anthropogenic disturbance, and the rate of population change (Λ) for 6 populations of boreal caribou in Alberta, Canada. We defined functional habitat loss according to 2 variables for which we had a priori reasons to suspect causative associations with Λ: 1) percentage area of caribou range within 250 m of anthropogenic footprint, and 2) percentage of caribou range disturbed by wildfire within the last 50 years. Multiple regression coefficients for both independent variables indicated significant effects on Λ. The 2‐predictor model explained 96% (R2) of observed variation in Λ among population units (F2,3 = 35.2, P = 0.008). The model may be used to evaluate plans for industrial development in relation to predicted wildfire rates and goals for caribou population growth rates.
Using Pellet Counts to Estimate Snowshoe Hare Numbers in Minnesota
Authors: MCCANN NICHOLAS P. , MOEN RON A. , NIEMI GERALD J.
Published: April 2008

Abstract:We calibrated snowshoe hare (Lepus americanus) numbers with pellet counts in Minnesota, USA, to understand the relationship between hare numbers and pellets in the central portion of the hare range. We found a strong and significant correlation between hare numbers and pellet counts using either linear or functional regression with either annual or semiannual pellet counts. Equations we developed using linear or functional regression predicted >1 hare/ha at similar pellet‐density thresholds. These equations can be used to efficiently identify habitats that support hare numbers necessary for Canada lynx (Lynx canadensis) persistence in Minnesota.
Demographic Sensitivity of Population Change in Northern Bobwhite
Authors: SANDERCOCK BRETT K. , JENSEN WILLIAM E. , WILLIAMS CHRISTOPHER K. , APPLEGATE ROGER D.
Published: April 2008

Abstract: The northern bobwhite (Colinus virginianus) is an economically important gamebird that is currently undergoing widespread population declines. Despite considerable research on the population ecology of bobwhites, there have been few attempts to model population dynamics of bobwhites to determine the contributions of different demographic parameters to variance of the finite rate of population change (Λ). We conducted a literature review and compiled 405 estimates of 9 demographic parameters from 49 field studies of bobwhites. To identify demographic parameters that might be important for management, we used life‐stage simulation analyses (LSA) to examine sensitivity of Λ to simulated variation in 9 demographic parameters for female bobwhites. In a baseline LSA based on uniform distributions bounded by the range of estimates for each demographic parameter, bobwhite populations were predicted to decline (Λ = 0.56) and winter survival of adults made the greatest contribution to variance of Λ (r2 = 0.453), followed by summer survival of adults (r2 = 0.163), and survival of chicks (r2 = 0.120). Population change was not sensitive to total clutch laid, nest survival, egg hatchability, or 3 parameters associated with the number of nesting attempts (r2<0.06). Our conclusions were robust to alternative simulation scenarios, and parameter rankings changed only if we adjusted the lower bounds of winter survival upwards. Bobwhite populations were not viable with survival rates reported from most field studies. Survival rates may be depressed below sustainable levels by environmental conditions or possibly by impacts of capture and telemetry methods. Overall, our simulation results indicate that management practices that improve seasonal survival rates will have the greatest potential benefit for recovery of declining populations of bobwhites.
Evaluation of Electric Fencing to Inhibit Feral Pig Movements
Authors: REIDY MATTHEW M. , CAMPBELL TYLER A. , HEWITT DAVID G.
Published: April 2008

Abstract: Natural resource managers and agricultural producers are seeking innovative tools to minimize damages caused by rapidly expanding feral pig (Sus scrofa) populations. One tool that has received little scientific inquiry is the use of exclusion fences to protect economically and ecologically sensitive areas. Our objectives were to evaluate the ability of electric fencing to minimize feral pig movements in a captive setting as well as in rangeland and agriculture land. In captivity, we tested a 1‐, 2‐, and 3‐strand electric fence. In our captive trial, we found 65% fewer intrusions (F2,18 = 20.46, P < 0.001) for electric fences (x̄ = 12.4, SE = 2.8) compared with nonelectric fences (x̄ = 35.6, SE = 6.9). We found no difference (F2,9 = 1.85, P = 0.212) for 1‐strand (x̄ = 28.1, SE = 7.8), 2‐strand (x̄ = 14.2, SE = 3.2), and 3‐strand (x̄ = 16.9, SE = 4.3) electric fences. However, we found 50% and 40% fewer crossings for the 2‐ and 3‐strand fences, respectively, compared with the 1‐strand fence. In our rangeland trial, we found 49% fewer intrusions (F2,18 =4.39, P = 0.028) into bait stations with a 2‐strand electric fence (x̄ =4.1, SE = 1.8) compared with no fence (x̄ =8.1, SE = 2.4). Finally, in our agriculture trial, we found 64% less damage (X22 = 5.77, P = 0.016) to sorghum crops with a 2‐strand electric fence (x̄ = 4.48, SE = 0.01%) compared with no electric fence (x̄ = 12.46, SE = 0.03%). Furthermore we found no (X11 = 3.72, P = 0.054) wildlife pathways in areas with an electric fence (x̄ = 0.0, SE =0.0) compared with no fence (x̄ = 2.4, SE= 1.3). No electric fence design we tested was 100% pig‐proof However, we found electric fencing restricted feral pig movements. Combining electric fencing with other damage control methods in an integrated management program may be the best method for alleviating feral pig damages.
Evaluation of a Diabetes Management System Based on Practice Guidelines, Integrated Care, and Continuous Quality Management in a Federal State of Germany
Authors: Rothe Ulrike , Müller Gabriele , Schwarz Peter E.H. , Seifert Martin , Kunath Hildebrand , Koch Rainer , Bergmann Sybille , Julius Ulrich , Bornstein Stefan R. , Hanefeld Markolf , Schulze Jan
Published: April 2008

OBJECTIVE—The aim of this study was to evaluate the Saxon Diabetes Management Program (SDMP), which is based on integrated practice guidelines, shared care, and integrated quality management. The SDMP was implemented into diabetes contracts between health insurance providers, general practitioners (GPs), and diabetes specialized practitioners (DSPs) unified in the Saxon association of Statutory Health Insurance Physicians.

RESEARCH DESIGN AND METHODS—The evaluation of the SDMP in Germany represents a real-world study by using clinical data collected from participating physicians. Between 2000 and 2002 all DSPs and about 75% of the GPs in Saxony participated. Finally, 291,771 patients were included in the SDMP. Cross-sectional data were evaluated at the beginning of 2000 (group A1) and at the end of 2002 (group A2). A subcohort of 105,204 patients was followed over a period of 3 years (group B).

RESULTS—The statewide implementation of the SDMP resulted in a change in therapeutic practice and in better cooperation. The median A1C at the time of referral to DSPs decreased from 8.5 to 7.5%, and so did the overall mean. At the end, 78 and 61% of group B achieved the targets for A1C and blood pressure, respectively, recommended by the guidelines compared with 69 and 50% at baseline. Patients with poorly controlled diabetes benefited the most. Preexisting regional differences were aligned.

CONCLUSIONS—Integrated care disease management with practicable integrated quality management including collaboration between GPs and specialist services is a significant innovation in chronic care management and an efficient way to improve diabetes care continuously.
Relation of Left Ventricular Function, Mass, and Volume to NT-proBNP in Type 1 Diabetic Patients
Authors: Astrup Anne Sofie , Kim Won Yong , Tarnow Lise , Botnar René M. , Simonsen Cheryl , Brix Lau , Pietraszek Lotte , Hansen Peter Riis , Manning Warren J. , Parving Hans-Henrik
Published: April 2008

OBJECTIVES—To measure left ventricular mass (LVM), left ventricular volumes, and left ventricular function (LVF) in a cohort of type 1 diabetic patients and to correlate measures of imaging to NH2-terminal pro-brain natriuretic peptide (NT-proBNP).

RESEARCH DESIGN AND METHODS—In a cross-sectional study, all patients with type 1 diabetes underwent cardiovascular magnetic resonance imaging. We included 63 patients with diabetic nephropathy and 73 patients with normoalbuminuria.

RESULTS—All patients had normal global LVF. LVM was increased in patients with diabetic nephropathy compared with patients with persistent normoalbuminuria. Patients with nephropathy had smaller left ventricular volumes and increased levels of NT-proBNP. Linear regression analysis in patients with diabetic nephropathy showed that NT-proBNP and creatinine were associated with LVM.

CONCLUSIONS—Increased LVM is identified in asymptomatic type 1 diabetic patients with nephropathy compared with normoalbuminuric patients. Elevated levels of NT-proBNP were associated with increased LVM, which are both markers of increased cardiovascular risk.
Medication Adherence and Racial Differences in A1C Control
Authors: Adams Alyce S. , Trinacty Connie Mah , Zhang Fang , Kleinman Ken , Grant Richard W. , Meigs James B. , Soumerai Stephen B. , Ross-Degnan Dennis
Published: April 2008

OBJECTIVE—The purpose of this study was to examine medication adherence and other self-management practices as potential determinants of higher glycemic risk among black relative to white patients.

RESEARCH DESIGN AND METHODS—We used a retrospective, longitudinal repeated-measures design to model the contribution of medication adherence to black-white differences in A1C among type 2 diabetic patients at a large multispecialty group practice. We identified 1,806 adult (aged ≥18 at diagnosis) patients (467 black and 1,339 white) with newly initiated oral hypoglycemic therapy between 1 December 1994 and 31 December 2000. Race was identified using an electronic medical record and patient self-report. Baseline was defined as the 13 months preceding and included the month of therapy initiation. All patients were required to have at least 12 months of follow-up.

RESULTS—At initiation of therapy, black patients had higher average A1C values compared with whites (9.8 vs. 8.9, a difference of 0.88; P < 0.0001). Blacks had lower average medication adherence during the first year of therapy (72 vs. 78%; P < 0.0001). Although more frequent medication refills were associated with lower average A1C values, adjustment for adherence did not eliminate the black-white gap.

CONCLUSIONS—We found persistent racial differences in A1C that were not explained by differences in medication adherence. Our findings suggest that targeting medication adherence alone is unlikely to reduce disparities in glycemic control in this setting. Further research is needed to explore possible genetic and environmental determinants of higher A1C among blacks at diagnosis, which may represent a critical period for more intensive intervention.
Serum Prostate-Specific Antigen Levels in Men With Type 2 Diabetes
Authors: Fukui Michiaki , Tanaka Muhei , Kadono Mayuko , Imai Saeko , Hasegawa Goji , Yoshikawa Toshikazu , Nakamura Naoto
Published: April 2008

OBJECTIVE—The aims of this study were to examine if serum prostate-specific antigen (PSA) levels are lower in men with type 2 diabetes compared with those in healthy men and to investigate what factors may be associated with serum PSA levels in men with type 2 diabetes.

RESEARCH DESIGN AND METHODS—We compared the serum PSA levels in 224 diabetic men with those in 1,293 healthy men and investigated the relationships between serum PSA levels and various variables.

RESULTS—Except for men aged 40–49 years, serum PSA levels were lower in diabetic men than in healthy men. Multiple regression analysis demonstrated that age, BMI, and presence of diabetes were independent determinants of serum PSA level.

CONCLUSIONS—Serum PSA levels were lower in diabetic men compared with those in healthy men, which is in line with previous reports that patients with type 2 diabetes are at a decreased risk of prostate cancer.
Fully Automated Closed-Loop Insulin Delivery Versus Semiautomated Hybrid Control in Pediatric Patients With Type 1 Diabetes Using an Artificial Pancreas
Authors: Weinzimer Stuart A. , Steil Garry M. , Swan Karena L. , Dziura Jim , Kurtz Natalie , Tamborlane William V.
Published: April 2008

OBJECTIVE—The most promising β-cell replacement therapy for children with type 1 diabetes is a closed-loop artificial pancreas incorporating continuous glucose sensors and insulin pumps. The Medtronic MiniMed external physiological insulin delivery (ePID) system combines an external pump and sensor with a variable insulin infusion rate algorithm designed to emulate the physiological characteristics of the β-cell. However, delays in insulin absorption associated with the subcutaneous route of delivery inevitably lead to large postprandial glucose excursions.

RESEARCH DESIGN AND METHODS—We studied the feasibility of the Medtronic ePID system in youth with type 1 diabetes and hypothesized that small manual premeal “priming” boluses would reduce postprandial excursions during closed-loop control. Seventeen adolescents (aged 15.9 ± 1.6 years; A1C 7.1 ± 0.8%) underwent 34 h of closed-loop control; 8 with full closed-loop (FCL) control and 9 with hybrid closed-loop (HCL) control (premeal priming bolus).

RESULTS—Mean glucose levels were 135 ± 45 mg/dl in the HCL group versus 141 ± 55 mg/dl in the FCL group (P = 0.09); daytime glucose levels averaged 149 ± 47 mg/dl in the HCL group versus 159 ± 59 mg/dl in the FCL group (P = 0.03). Peak postprandial glucose levels averaged 194 ± 47 mg/dl in the HCL group versus 226 ± 51 mg/dl in the FCL group (P = 0.04). Nighttime control was similar in both groups (111 ± 27 vs. 112 ± 28 mg/dl).

CONCLUSIONS—Closed-loop glucose control using an external sensor and insulin pump provides a means to achieve near-normal glucose concentrations in youth with type 1 diabetes during the overnight period. The addition of small manual priming bolus doses of insulin, given 15 min before meals, improves postprandial glycemic excursions.
Acute Complications and Drug Misuse Are Important Causes of Death for Children and Young Adults With Type 1 Diabetes
Authors: Feltbower Richard G. , Bodansky H. Jonathan , Patterson Christopher C. , Parslow Roger C. , Stephenson Carolyn R. , Reynolds Catherine , McKinney Patricia A.
Published: April 2008

OBJECTIVE—To examine mortality rates and causes of death among subjects diagnosed with type 1 diabetes aged ≤29 years.

RESEARCH DESIGN AND METHODS— Subjects with type 1 diabetes from a population-based register in Yorkshire, U.K., diagnosed between 1978 and 2004 were linked to the U.K. National Health Service Central Register for death notifications. Deaths were coded using ICD-9 (1979–2000) and ICD-10 (2001–2005). Standardized mortality ratios (SMRs) were calculated using expected numbers of deaths from U.K. mortality rates by cause of death and age at diagnosis.

RESULTS—A total of 4,246 individuals were followed up, providing 50,471 person-years of follow-up. Mean follow-up length was 12.8 years for individuals aged 0–14 years and 8.3 for those aged 15–29 years. Overall, 108 patients died, of whom 77 (71%) were male. A total of 74 (1.7/1,000 person-years) deaths occurred in inidividuals aged 0–14 years and 34 (4.6/1,000 person-years) in those aged 15–29 years. The SMR was 4.7 (95% CI 3.8–5.6) overall, similar for males and females, but higher for individuals aged 15–29 years (SMR 6.2 [95% CI 4.3–8.6]) compared with those aged 0–14 years (4.2 [3.3–5.3]). The SMR rose with increasing disease duration. A total of 47 of 108 deaths (44%) occurred from diabetes complications, 32 of which were acute and 15 chronic. Twenty-two percent (n = 24) of deaths were attributed to accidents or violence (SMR 2.1 [95% CI 1.4–3.2]), including six suicides. Sixteen percent of all deaths were related to drug misuse (including insulin but excluding tobacco and alcohol) (SMR 6.4 [95% CI 3.7–10.2]).

CONCLUSIONS—Subjects with type 1 diabetes diagnosed under 30 years of age had a 4.7-fold excess mortality risk. Nearly half of the deaths were due to acute or chronic complications of diabetes. Drug misuse–related deaths may be an emerging trend in this population warranting further investigation.
Prediction of Mortality in Type 2 Diabetes From Health-Related Quality of Life (ZODIAC-4)
Authors: Kleefstra Nanne , Landman Gijs W.D. , Houweling Sebastiaan T. , Ubink-Veltmaat Lielith J. , Logtenberg Susan J.J. , Meyboom-de Jong Betty , Coyne James C. , Groenier Klaas H. , Bilo Henk J.G.
Published: April 2008

OBJECTIVE—To investigate the relationship between health-related quality of life (HRQOL) and mortality in type 2 diabetes.

RESEARCH DESIGN AND METHODS—In 1998, 1,143 primary care patients with type 2 diabetes participated in the Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) study. At baseline, HRQOL was assessed with the RAND-36 and, after almost 6 years, life status was retrieved. Cox proportional hazards modeling was used to investigate the association between HRQOL (continuous data) and mortality with adjustment for selected confounders (smoking, age, sex, diabetes duration, A1C, renal function, BMI, blood pressure, HDL cholesterol, and macrovascular complications).

RESULTS—The Physical Component Summary of the RAND-36 was inversely associated with mortality (hazard ratio [HR] 0.979 [95% CI 0.966–0.992]), as were two separate RAND-36 dimensions.

CONCLUSIONS—This study found that HRQOL is an independent marker of mortality and emphasizes the importance of looking beyond clinical parameters in patients with type 2 diabetes.
Determinants for the Effectiveness of Lifestyle Intervention in the Finnish Diabetes Prevention Study
Authors: Lindström Jaana , Peltonen Markku , Eriksson Johan G. , Aunola Sirkka , Hämäläinen Helena , Ilanne-Parikka Pirjo , Keinänen-Kiukaanniemi Sirkka , Uusitupa Matti , Tuomilehto Jaakko ,   for the Finnish Diabetes Prevention Study (DPS) Group
Published: April 2008

OBJECTIVE—Intensive lifestyle intervention significantly reduced diabetes incidence among the participants in the Finnish Diabetes Prevention Study. We investigated whether and to what extent risk factors for type 2 diabetes and other baseline characteristics of the study participants modified the effectiveness of the lifestyle intervention.

RESEARCH DESIGN AND METHODS—Overweight, middle-aged volunteers with impaired glucose tolerance were randomly assigned to intensive lifestyle intervention (n = 265) or to a control group (n = 257) for a median of 4 years. Diabetes status was ascertained annually with repeated oral glucose tolerance testing. Incidence rates of diabetes and hazard ratios (HRs) comparing the intervention group with the control group were calculated by sex and baseline tertiles of age, BMI, waist circumference, plasma glucose concentration at fasting and 2 h after a glucose load, fasting serum insulin and insulin resistance index, and categories of composite baseline Finnish Diabetes Risk Score (FINDRISC). Interactions between the intervention assignment and baseline risk factors on diabetes risk were analyzed.

RESULTS—The intervention was most effective among the oldest individuals (HRs 0.77, 0.49, and 0.36 by increasing age tertiles, respectively; Pinteraction = 0.0130) and those with a high baseline FINDRISC (HRs 1.09, 0.84, 0.34, and 0.22 by increasing risk score category, respectively; Pinteraction = 0.0400). The effect of the intervention on diabetes risk was not modified by other baseline characteristics or risk factors.

CONCLUSIONS—The FINDRISC may be useful in identifying high-risk groups most likely to benefit from intensive lifestyle intervention to prevent type 2 diabetes.
Rosiglitazone-Associated Fractures in Type 2 Diabetes
Authors: Kahn Steven E. , Zinman Bernard , Lachin John M. , Haffner Steven M. , Herman William H. , Holman Rury R. , Kravitz Barbara G. , Yu Dahong , Heise Mark A. , Aftring R. Paul , Viberti Giancarlo ,   for the A Diabetes Outcome Progression Trial (ADOPT) Study Group
Published: April 2008

OBJECTIVE—The purpose of this study was to examine possible factors associated with the increased risk of fractures observed with rosiglitazone in A Diabetes Outcome Progression Trial (ADOPT).

RESEARCH DESIGN AND METHODS—Data from the 1,840 women and 2,511 men randomly assigned in ADOPT to rosiglitazone, metformin, or glyburide for a median of 4.0 years were examined with respect to time to first fracture, rates of occurrence, and sites of fractures.

RESULTS—In men, fracture rates did not differ between treatment groups. In women, at least one fracture was reported with rosiglitazone in 60 patients (9.3% of patients, 2.74 per 100 patient-years), metformin in 30 patients (5.1%, 1.54 per 100 patient-years), and glyburide in 21 patients (3.5%, 1.29 per 100 patient-years). The cumulative incidence (95% CI) of fractures in women at 5 years was 15.1% (11.2–19.1) with rosiglitazone, 7.3% (4.4–10.1) with metformin, and 7.7% (3.7–11.7) with glyburide, representing hazard ratios (95% CI) of 1.81 (1.17–2.80) and 2.13 (1.30–3.51) for rosiglitazone compared with metformin and glyburide, respectively. The increase in fractures with rosiglitazone occurred in pre- and postmenopausal women, and fractures were seen predominantly in the lower and upper limbs. No particular risk factor underlying the increased fractures in female patients who received rosiglitazone therapy was identified.

CONCLUSIONS—Further investigation into the risk factors and underlying pathophysiology for the increased fracture rate in women taking rosiglitazone is required to relate them to preclinical data and better understand the clinical implications of and possible interventions for these findings.
Outcome After Leg Bypass Surgery for Critical Limb Ischemia Is Poor in Patients With Diabetes
Authors: Malmstedt Jonas , Leander Karin , Wahlberg Eric , Karlström Lars , Alfredsson Lars , Swedenborg Jesper
Published: April 2008

OBJECTIVE—Our aim was to assess the risk of major amputation or death after leg bypass surgery for critical limb ischemia in patients with diabetes versus those without.

RESEARCH DESIGN AND METHODS—We did a population-based cohort study by linking nationwide databases in Sweden. We identified 1,840 patients in the Swedish Vascular Registry who had their first leg bypass procedure for critical lower-limb ischemia between 1 January 2001 and 31 December 2003—742 with and 1,098 without diabetes. Our primary end point was first major amputation of the limb on which bypass was done or death. Individuals were followed up until 31 December 2005 through the National Hospital Patient Registry and the Cause-of-Death Registry.

RESULTS—Incidence of ipsilateral amputation or death was higher in patients with diabetes than in patients without (30.2 vs. 22 events/100 person-years; crude hazard ratio [HR] 1.32 [95% CI 1.17–1.50]). Similarly, individuals with diabetes had a shorter amputation-free survival period than individuals without (2.3 years, range 1.9–2.8 vs. 3.4 years, range 3.1–3.7). Adjustment for demographic characteristics, comorbidities, and risk factors for amputation or death did not substantially affect the risk (HR 1.46 [95% CI 1.26–1.69]). The effect was more pronounced in male (1.75 [1.47–2.08]) than in female (1.35 [1.11–1.64]) patients after adjustment for age.

CONCLUSIONS—Diabetes is associated with lower amputation–free survival after leg bypass for critical limb ischemia. Patients with diabetes and limb ischemia need intensified treatment of diabetes-related risk factors to improve outcome.
Contribution of the Flexor Hallucis Longus to Loading of the First Metatarsal and First Metatarsophalangeal Joint
Authors: Kirane Y. M. , Michelson James D. , Sharkey Neil A.
Published: April 2008

Background

A recent clinical study suggested that restrictive tenosynovitis of the flexor hallucis longus (FHL) may play an important causative role in hallux rigidus. The goals of this research were to assess normal function of the FHL and the effect of restricted FHL gliding on the loading of the hallux metatarsophalangeal joint (MTPJ). We hypothesized that proximal displacement of the FHL would increase the forces carried by the FHL tendon, causing increased loading of the first metatarsal and MTPJ.

Materials and Methods

Dynamic simulations of the stance phase of walking were created by loading 5 non-embalmed, non-paired cadaver lower extremities (2 male, 3 female; mean age, 69; range, 56 to 75) in the Robotic Dynamic Activity Simulator (RDAS). The RDAS recreates lower leg motion and muscle activity based on kinematic and electromyographic data of healthy subjects. FHL tendon forces and excursions were measured for the entire stance phase of gait. Bone strains in the mid-shaft of the first metatarsal were recorded and used to derive the in situ forces and moments imposed on the metatarsal and the hallux MTPJ.

Results

Under force-feedback control, FHL excursion averaged 6.57 (±3.13) mm during gait. When the FHL was held 2-, 4-, and 6-mm proximal to the mid-point of normal excursion to simulate progressive stenosis, the forces in the FHL tendon, first metatarsal and first MTP joint were progressively, and significantly, increased ( p < 0.05).

Conclusion

These findings support the hypothesis that progressive fibrosis at the FHL myotendinous junction can cause increased loading of the hallux MTPJ, thereby leading to hallux rigidus.
Neuropathic Plantar Forefoot Ulcers Treated with Tendon Lengthenings
Authors: Laborde James Monroe
Published: April 2008

Background

Foot ulcers are a common cause of infection and amputation in patients with neuropathy. This retrospective study evaluated the healing and recurrence rates after treating neuropathic ulcers plantar to the metatarsal heads with tendon lengthenings in the leg.

Materials and Methods

Between 1995 and 2003, 20 ulcers plantar to the metatarsal heads in 17 patients were treated with tendon lengthenings. All patients had gastroc-soleus recession (Vulpius procedure). Patients with first metatarsal head ulcers also had Z-type lengthenings of the peroneus longus. Patients with fifth metatarsal head ulcers also had intramuscular lengthening of the tibialis posterior. Patients with second, third, and fourth metatarsal head ulcers had only a gastroc-soleus recession.

Results

All patients had neuropathy; 15 patients with 17 ulcers had diabetes mellitus. All incisions healed primarily without infection. Nineteen of 20 ulcers healed. One patient with one ulcer was lost to followup after the ulcer healed. Average followup for the remaining 19 ulcers was 45 months. Average duration of the 19 ulcers before surgery was 17 months. Three of 19 ulcers recurred and had repeat tendon lengthening and healed again. None of the patients whose ulcers healed had to be admitted for foot infection or amputation. The one patient whose ulcer did not heal developed progressive dry gangrene which required trans-femoral amputation six months after tendon lengthening.

Conclusion

Tendon lengthenings in the leg seem to be effective in healing and preventing recurrence of neuropathic ulcers plantar to the metatarsal head with a low complication rate.
Radiographic Comparison of Sagittal Plane Stability between Cast and Boots
Authors: Kadakia Anish R. , Espinosa Norman , Smerek Jonathan , White Kacey , Myerson Mark S. , Jeng Clifford L.
Published: April 2008

Background

The importance of postoperative stability when considering surgery on the foot and ankle cannot be overestimated. To our knowledge, no literature exists to describe the radiographic sagittal plane motion with varying types of immobilization devices. The purpose of this study was to evaluate the sagittal plane range of motion allowed in different types of boots in comparison to fiberglass cast treatment on normal human subjects.

Materials and Methods

Ten healthy volunteers without preexisting foot and ankle pathology were chosen for the study. Five types of immobilization were selected for testing, including 4 off-the-shelf braces and a fiberglass cast. Maximum dorsiflexion and maximum plantarflexion lateral radiographs were taken without any immobilization and in the fiberglass cast and all walkers.

Results

The mean range of motion in a fiberglass cast was 8.4 degrees (SD, 4.3 degrees); FP Foam Walker, 16 degrees (SD, 6.7 degrees); XP Pneumatic Walker, 15.4 degrees (SD, 5.6 degrees); Donjoy Max Walker, 19.1 degrees (5.4 degrees); and the SP Walker, 39 degrees (SD, 10.7 degrees). The cast was noted to have a significantly greater limitation of sagittal plane motion compared to all other forms of immobilization ( p < 0.05).

Conclusion

Sagittal plane motion is restricted significantly more with a fiberglass cast compared to the FP Foam Walker, and XP Pneumatic Walker, Donjoy Max Walker, and the SP Walker. Therefore, in patients whom maximum restriction of sagittal plane motion is required, use of a fiberglass cast offers superior control.
Optimizing Achilles Tendon Repair: Effect of Epitendinous Suture Augmentation on the Strength of Achilles Tendon Repairs
Authors: Lee Steven J. , Goldsmith Scott , Nicholas Stephen J. , McHugh Malachy , Kremenic Ian , Ben-Avi Simon
Published: April 2008

Background

Epitendinous suture augmentation has been shown to increase gap resistance and overall strength in flexor tendon repairs of the hand. The purpose of this study was to evaluate the effect of various suture augmentation techniques in Achilles tendon repair.

Materials and Methods

Eighteen fresh-frozen cadaveric Achilles tendons were transected and repaired with a 4-strand Krackow core stitch. Suture augmentation was performed with 3 figure-of-eight stitches in 6 specimens and a running cross-stitch weave in 6 specimens. The other 6 specimens were not augmented. Each tendon was loaded to failure on an MTS. Force to failure (defined as peak force or force at 5 mm gapping), gapping resistance, stiffness, and elongation were compared.

Results

Force to failure ( p < 0.001), stiffness ( p < 0.01) and gapping resistance ( p < 0.05) were increased by suture augmentation. Additionally failure force and gapping resistance for the cross-stitch augmentation was higher than the figure-of-eight augmentation ( p < 0.05).

Conclusion

Cross-stitch augmentation of Achilles tendon repair yields a stronger and stiffer repair with greater resistance to gapping.

Clinical Relevance

Achilles tendon repairs augmented with a cross stitch weave will be able to withstand substantially higher forces than non-augmented repairs.
Osteochondritis Dissecans of the Tarsal Navicular
Authors: Ozturk Ersin , Sirvanci Mustafa , Mutlu Hakan , Duran Cihan , Sonmez Guner
Published: April 2008

A 27-year-old male athlete presented with chronic right dorsal midfoot pain and limitation in midfoot movements. Computed tomography and magnetic resonance imaging demonstrated an nondisplaced osteochondral fragment within the proximal articular surface of the tarsal navicular. Imaging findings of this disease are presented and discussed.
Assessing the Demand for Scholarly Publishing in South Africa
Authors: Roux Elizabeth le , Galloway Francis
Published: April 2008

It is often assumed that African scholarly publishing is poorly resourced and unappealing to authors, both African and otherwise. While the resource constraints are real, is it true that authors are avoiding African publishers in favour of those based in the North? An exploratory study was undertaken to assess the demand for scholarly publishers based in South Africa but serving the continent as a whole. The qualitative survey, though not based on a large and widely generalizable sample, indicates some clear trends and, in so doing, explodes the myth of the African publisher as the site of last resort for academic authors. Rather, the results show broad support for locally based publishers, and many respondents expressed a need for far more publishers, wherever they may be based. Certain guidelines are derived from this survey to indicate trends for scholarly publishers working in this region.
Historical Scholarship, Periodization, Themes, and Specialization: Implications for Research and Publication
Authors: Hérubel Jean-Pierre V.M.
Published: April 2008

Within the scholarly communication system, historical scholarship represents a burgeoning and evolving intellectual topography. This discussion attempts to frame historical research and scholarship within a contextual disciplinary environment where specialization and the use of historical periodization and discrete themes reflect necessary conditions of historical research and scholarship. Normative practice and conditions animating the academic historical enterprise generate and maintain the drive to specialization appearing in various publication venues. Historians necessarily hone specific periods, themes, or orientations, addressing historiographic conditions that lie at the centre of historical research and scholarship. The drive toward highly articulated monographs, journals, and reference publications speaks to this particular phenomenon in historical research and scholarship. The logic animating graduate history education and training and the momentum toward specialization, as well as hyper-specialization, exert influence, if not pressure, upon the scholarly publication system. Historians concentrating on highly honed and articulated research endeavour to disseminate their scholarship in venues that address their intellectual and historiographic orientations and preoccupations. The disciplinary and intellectual morphology of historical research and scholarly publication cannot be adequately appreciated without considering these phenomena.
Sinners Well Edited
Authors: Deville Adam A.J.
Published: April 2008

It is not possible to blame ‘technology’ for the inability of many academics to write well, because most of today's faculty were trained before the advent of cell phones and computers. Bad writing is, as Lindsay Waters suggest in Enemies of Promise: Publishing, Perishing, and the Eclipse of Scholarship, partly caused by too much administrative pressure for too much output. Editors are caught in the middle, between administrators trying to control costs and academics trying to get published. The author offers practical suggestions for academic writers to improve their writing and so save time and money on the part of editors and administrators.
Accuracy of References in Journals of Hand Surgery
Authors: Boya Hakan , Ozcan Ozal , Mete Abdullah M. , Gunal Izge
Published: April 2008

Three hundred randomly selected references collected from the Journal of Hand Surgery (American Volume), the Journal of Hand Surgery (British and European Volume), and the British Journal of Plastic Surgery, spanning the years 1998 to 2002, were evaluated for citation errors. Forty-four citations across all journals contained errors (14.6 per cent). None of the errors made the cited article impossible to retrieve. Ten of the forty-four inaccuracies were incorrect final page numbers.
Assessing species diagnostic value in large data sets: A comparison between phi‐coefficient and Ochiai index
Authors: De Cáceres M. , Font X. , Oliva F.
Published: April 2008

Question:

Diagnostic species are useful tools for the identification and ecological interpretation of community types. Vegetation databases facilitate the computation of diagnostic values of regional validity, but it is essential to understand the behaviour of fidelity measures in large data sets.

Methods:

We focused our study on the phi‐coefficient (φ) of association and its limit value, the Ochiai index. The northeast Spanish relevé database was stratified using an arbitrary distance threshold in species composition. Diagnostic species analysis was undertaken using three methods of context selection: I. within a syntaxon of higher rank; II. including relevés with similar composition to that of the target unit; III. using the entire stratified database. Species diagnostic values were computed as well as bootstrap percentile confidence intervals.

Results:

Many species deemed as diagnostic by method I have their optima in vegetation types neighbouring the unit chosen as context. In contrast, method II excluded many of these species. φ‐values and confidence intervals were similar to those obtained by the Ochiai indexwhen using a large dataset (method III) but this similarity was greater for low level syntaxa.

Conclusions:

The diagnostic value of species in a given region is best assessed using the Ochiai index, since it can be split into two interpretable asymmetrical components. We recommend the determination of context‐dependent differential species using the φ‐coefficient, and the assessment of species regional diagnostic value by means of a stratification procedure in combination with the Ochiai index.
Evidence for “diminishing returns” from the scaling of stem diameter and specific leaf area
Authors: Niklas Karl J. , Cobb Edward D.
Published: April 2008

Research indicates that increases in total leaf area (AT) may fail to keep pace with increases in total leaf mass (ML) across plants differing in size (e.g., as measured by stem diameter,D). This “diminishing returns” hypothesis predicts that the scaling exponent forATvs.MLwill be less than one and that the exponent for specific leaf mass (i.e.,AT/ML) vs.Dwill be negative. These predictions were examined using data from 46 plants ranging between 0.125 cm ≤D≤ 0.485 m across 25 woody dicot species. Standardized major axis slopes were used to quantify scaling exponents and random effects models were used to quantify species and size effects on the numerical values of exponents. The exponents forATvs.MLandAT/MLvs.Ddiffered among species and different species groupings. In general, the exponent forATvs.MLwas less than one and the exponent forAT/MLvs.Dwas negative, as predicted. However, random effects models indicated that species effects overshadowed size effects, although size effects were statistically significant. The diminishing returns hypothesis therefore receives statistical support, i.e., although the numerical values of exponents are “species‐dependent,” they are less than unity, as predicted by theory.
Mass flowering and parental death in the regeneration ofCerberiopsis candelabra(Apocynaceae), a long‐lived monocarpic tree in New Caledonia1
Authors: Read Jennifer , Sanson Gordon D. , Burd Martin , Jaffré Tanguy
Published: April 2008

Monocarpy is rare among forest trees, and the selective conditions allowing this life history to evolve are poorly known. Here we examined the regeneration dynamics of a New Caledonian monocarpic tree species,Cerberiopsis candelabra, to better understand how postreproductive mortality and mass flowering might contribute to the success of this strategy. We investigated population size structures and seedling establishment patterns in 18 stands following the 2003 flowering event. We found little evidence of recent recruitment. Instead, population size structures suggested a history of one or more substantial recruitment events followed by recruitment failure, despite multiple flowering events in most populations. The canopy gap created by death of an individual parent appeared generally insufficient to allow seedling establishment, but mass flowering and consequent death of many adults appeared to enhance seedling recruitment by opening more of the canopy. Site means of seedling density below dead parents correlated strongly with light availability and with the proportional density of flowering trees. Therefore, we suggest that mass flowering and gregariousness may have been necessary preconditions for the evolution of monocarpy in this species. However, the degree to which regeneration relies on synchronous flowering and gregariousness vs. infrequent catastrophic disturbances remains uncertain.
The evolutionary relations of sunken, covered, and encrypted stomata to dry habitats in Proteaceae
Authors: Jordan Gregory J. , Weston Peter H. , Carpenter Raymond J. , Dillon Rebecca A. , Brodribb Timothy J.
Published: April 2008

Sunken, covered, and encrypted stomata have been anecdotally linked with dry climates and reduced transpiration and therefore have been used to infer dry palaeoclimates from fossils. This study assesses the evolutionary and ecological associations of such stomatal protection in a model system—the diverse southern hemisphere family Proteaceae. Analyses were based on the morphology of over 1400 Australian, South African, New Caledonian, New Zealand, and South American species, anatomy of over 300 of these species, and bioclimatic data from all 1109 Australian species. Ancestral state reconstruction revealed that five or six evolutionary transitions explain over 98% of the dry climate species in the family, with a few other, minor invasions of dry climates. Deep encryption, i.e., stomata in deep pits, in grooves, enclosed by tightly revolute margins or strongly overarched by cuticle, evolved at least 11 times in very dry environments. Other forms of stomatal protection (sunken but not closely encrypted stomata, papillae, and layers of hairs covering the stomata) also evolved repeatedly, but had no systematic association with dry climates. These data are evidence for a strong distinction in function, with deep encryption being an adaptation to aridity, whereas broad pits and covered stomata have more complex relations to climate.