bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing tropical forest tree size distributions with the predictions of metabolic ecology and equilibrium models
Authors: Muller‐Landau Helene C. , Condit Richard S. , Harms Kyle E. , Marks Christian O. , Thomas Sean C. , Bunyavejchewin Sarayudh , Chuyong George , Co Leonardo , Davies Stuart , Foster Robin , Gunatilleke Savitri , Gunatilleke Nimal , Hart Terese , Hubbell Stephen P. , Itoh Akira , Kassim Abd Rahman , Kenfack David , LaFrankie James V. , Lagunzad Daniel , Lee Hua Seng , Losos Elizabeth , Makana Jean‐Remy , Ohkubo Tatsuhiro , Samper Cristian , Sukumar Raman , Sun I‐Fang , Nur Supardi M. N. , Tan Sylvester , Thomas Duncan , Thompson Jill , Valencia Renato , Vallejo Martha Isabel , Muñoz Gorky Villa , Yamakura Takuo , Zimmerman Jess K. , Dattaraja Handanakere Shavaramaiah , Esufali Shameema , Hall Pamela , He Fangliang , Hernandez Consuelo , Kiratiprayoon Somboon , Suresh Hebbalalu S. , Wills Christopher , Ashton Peter
Published: March 2006

Tropical forests vary substantially in the densities of trees of different sizes and thus in above‐ground biomass and carbon stores. However, these tree size distributions show fundamental similarities suggestive of underlying general principles. The theory of metabolic ecology predicts that tree abundances will scale as the −2 power of diameter. Demographic equilibrium theory explains tree abundances in terms of the scaling of growth and mortality. We use demographic equilibrium theory to derive analytic predictions for tree size distributions corresponding to different growth and mortality functions. We test both sets of predictions using data from 14 large‐scale tropical forest plots encompassing censuses of 473 ha and > 2 million trees. The data are uniformly inconsistent with the predictions of metabolic ecology. In most forests, size distributions are much closer to the predictions of demographic equilibrium, and thus, intersite variation in size distributions is explained partly by intersite variation in growth and mortality.
Systematic review on the short‐term outcome of laparoscopic resection for colon and rectosigmoid cancer
Authors: Tjandra J. J. , Chan M. K. Y.
Published: March 2006

Objective  Several large randomized controlled trials on laparoscopic resection for colon and rectosigmoid cancer have recently been published. There is a need to provide an up‐to‐date systematic review in this subject.

Methods  A literature search of all published randomized trials in English between January 1991 and September 2005 was obtained, from Ovid MEDLINE, EMBASE, CINAHL, and All EBM Reviews (Cochrane Central Register of Controlled Trial, Cochrane Database of Systemic Review, and Database of Abstracts of Reviews of Effects), including e‐links to the related articles. Two independent assessors reviewed the trials using a standardized protocol. Where means and standard deviations were available, meta‐analysis was performed using the Forest plot review. Studies where medians and ranges were presented were separately analysed.

Results  A total of 17 randomized controlled trials with 4013 procedures were reviewed. The conversion rate varied widely between studies and was lowest in single‐Centre trials. There were no significant differences in overall and surgical complication rate, anastomotic leak rate, re‐operation rate and oncological clearance. However, laparoscopic resection has a significantly lower peri‐operative mortality (odds ratio 0.33; P = 0.005), lower wound complications (odds ratio 0.65; P = 0.01), less blood loss (weighted mean difference 0.11 l; P < 0.00001) and reduced postoperative pain scores by 12.6% with reduction of requirements for narcotic analgesia by 30.7%. After laparoscopic surgery, patients passed flatus 38.8% earlier (weighted mean difference 27.6 h; P < 0.00001) and had bowel movement 21.0% earlier (weighted mean difference 23.9 h; P < 0.00001) and resumed oral diet 28.3% sooner than patients in the open group (weighted mean difference 27.3 h; P < 0.00001). Patients were discharged 19.1% earlier after laparoscopic surgery than open surgery (weighted mean difference 1.7 days; P < 0.00001). Laparoscopic resection took 28.7% longer (weighted mean difference 40.1 min; P < 0.00001) to perform.

Conclusions  Laparoscopic resection for colon and rectosigmoid cancer is feasible, safe and has many short‐term benefits.
New patients: should children be treated differently?
Authors: Dubinsky M. C.
Published: March 2006

Inflammatory bowel disease (IBD) in childhood is often diagnosed at a vulnerable time of growth and development, and is recognized as one of the most significant chronic gastrointestinal diseases to affect children. Children and adolescents with IBD are at increased risk of complications as a result of malnutrition secondary to reduced appetite, increased metabolism and decreased absorptive capacity. The most common and serious complications are growth failure, bone demineralization and impaired psychosocial development. These issues add to the complexity of childhood IBD management and it is essential that adequate medical management is in place to prevent these long‐term complications. Current treatment options include 5‐aminosalicylic acid, antibiotics, corticosteroids, nutritional therapy and immunomodulators used to induce and maintain remission; some are specifically employed to maintain a steroid free long‐term remission. As a general rule, long‐term corticosteroid use should be avoided to reduce the risk of bone demineralization and growth failure. Newer treatment options such as infliximab have been shown to be effective for inducing and prolonging remission of Crohn's disease in children and paediatric use of infliximab is likely to increase in the near future. A recent case report, involving a 15‐year old boy presenting with abdominal pain and bloody diarrhoea, illustrates the difficulty in correctly diagnosing IBD in children and the need for optimizing therapy to achieve treatment success.
Insulin increases gelatinase activity in rat glomerular mesangial cells via ERK‐ and PI‐3 kinase‐dependent signalling
Authors: Lee M. P. S. , Sweeney G.
Published: March 2006

Diabetic nephropathy is associated with increased accumulation of the extracellular matrix (ECM) in the kidney, which ultimately leads to kidney failure. This may occur due to excessive synthesis of ECM components or reduced degradation, a process primarily mediated by matrix metalloproteinases (MMPs). The direct effect of insulin on ECM synthesis and degradation in glomerular mesangial cells (GMCs) is unclear. Here, we show an increased gelatinase activity in conditioned media from insulin‐treated rat GMCs, determined by gelatin zymography. Furthermore, we show using the specific inhibitors LY294002 and PD98059 that insulin induced increased gelatinase activity via an intracellular signalling mechanism involving phosphatidylinositol‐3 kinase (PI‐3K) and the extracellular signal‐regulated kinase 1/2 (ERK1/2) mitogen‐activated protein kinases (MAPKs) respectively. In addition, we demonstrate that PI‐3 kinase and ERK1/2 MAPK are activated by insulin in GMCs. The appearance of protease activity at approximately 72 kDa suggested that MMP‐2 activity may be induced by insulin, however, we did not detect an increase in MMP‐2 expression by Western blotting. In summary, our results suggest that insulin can induce gelatinase activity in GMCs, and it is possible that loss of this input in insulin‐resistant type 2 diabetic individuals may contribute to ECM accumulation and the development of nephropathy.
Effect of sibutramine and of cognitive‐behavioural weight loss therapy in obesity and subclinical binge eating disorder
Authors: Bauer C. , Fischer A. , Keller U.
Published: March 2006

Aim:  In this randomized, double‐blind, placebo‐controlled study, the effect of sibutramine and cognitive‐behavioural weight loss (cognitive‐BWL) treatment was assessed in obese subjects with and without subclinical binge eating disorder (sBED).

Methods:  Seventy‐three obese participants were recruited from the community, 29 with and 44 without sBED. Subjects were randomly assigned to a 16‐week treatment with either sibutramine or placebo while simultaneously participating in a cognitive‐behavioural weight loss treatment.

Results:  Intent‐to‐treat analysis showed moderate weight loss after treatment in all subject groups. Treatment with BWL programs and sibutramine leads to a higher weight loss in all subjects compared with that in patients who had undergone BWL programs alone. Subjects with sBED significantly reduced their binge episodes during treatment, but with no augmenting effect of sibutramine.

Discussion:  Our results yield further evidence that sBED is associated with characteristics comparable with full‐syndrome BED, significantly differing from those of obesity alone. These findings call for a systematic assessment of eating behaviour before starting obesity treatment.
Effects of running exercise on fibre‐type distribution of soleus and plantaris muscles in diabetic Otsuka Long‐Evans Tokushima fatty rats
Authors: Yasuda K. , Adachi T. , Kikuchi N. , Tsujimoto G. , Aoki N. , Tsuda K. , Ishihara A.
Published: March 2006

Aim:  Effect of running exercise on fibre‐type distributions of the slow soleus and fast plantaris muscles was investigated in male Otsuka Long‐Evans Tokushima fatty rats (OLETF) as an animal model of spontaneous type 2 diabetes mellitus.

Methods:  Five‐week‐old OLETF rats were allowed to exercise voluntarily in running wheels for 32 days and the data were compared with those of age‐matched non‐exercised OLETF and non‐diabetic Long‐Evans Tokushima Otsuka rats (LETO).

Results:  In the soleus muscle, a higher percentage of type I fibres was observed in non‐exercised OLETF rats compared with LETO rats, and there were no type IIA fibres in non‐exercised OLETF rats. In the plantaris muscle, a higher percentage of type IIB fibres and a lower percentage of type I and type IIA fibres were observed in non‐exercised OLETF rats compared with LETO rats. In contrast, there were no differences in the fibre‐type distribution of soleus and plantaris muscles between exercised OLETF and LETO rats. The body weight and type I fibre percentage of the soleus muscle were related to the running distance in exercised OLETF rats. White adipose tissue weight, HbA1c and blood insulin and glucose concentrations were lower in exercised OLETF rats than in non‐exercised OLETF rats, irrespective of the running distance. There was a difference in the gene‐expression pattern of the soleus muscle among LETO rats, non‐exercised OLETF and exercised OLETF rats.

Conclusion:  Running exercise can inhibit diabetes‐associated type shifting of fibres, which is more apparent with postnatal growth, in skeletal muscles of diabetic OLETF rats, as a result of mRNA expression change in muscle.
Obesity‐related cardiovascular disease: implications of obstructive sleep apnea
Authors: Wolk R. , Somers V. K.
Published: March 2006

Obesity and obstructive sleep apnea (OSA) often coexist. OSA has been linked to cardiovascular disease. Thus, OSA may contribute to the cardiovascular consequences of obesity. In this review, we explore clinical and pathophysiological interactions between obesity, cardiovascular disease and OSA. We discuss the mechanisms whereby OSA may contribute to hypertension, atherosclerosis, insulin resistance and atrial fibrillation associated with obesity, and emphasize the potential implications for understanding why only a subgroup of obese patients develop cardiovascular disease. Identification of the OSA‐dependent and OSA‐independent pathways in the cardiovascular pathophysiology of obesity may hold clinical and therapeutic promise.
Adiponectin – a key adipokine in the metabolic syndrome
Authors: Whitehead J. P. , Richards A. A. , Hickman I. J. , Macdonald G. A. , Prins J. B.
Published: March 2006

Adiponectin is a recently described adipokine that has been recognized as a key regulator of insulin sensitivity and tissue inflammation. It is produced by adipose tissue (white and brown) and circulates in the blood at very high concentrations. It has direct actions in liver, skeletal muscle and the vasculature, with prominent roles to improve hepatic insulin sensitivity, increase fuel oxidation [via up‐regulation of adenosine monophosphate‐activated protein kinase (AMPK) activity] and decrease vascular inflammation. Adiponectin exists in the circulation as varying molecular weight forms, produced by multimerization. Recent data indicate that the high‐molecular weight (HMW) complexes have the predominant action in the liver. In contrast to other adipokines, adiponectin secretion and circulating levels are inversely proportional to body fat content. Levels are further reduced in subjects with diabetes and coronary artery disease. Adiponectin antagonizes many effects of tumour necrosis factor‐α(TNF‐α) and this, in turn, suppresses adiponectin production. Furthermore, adiponectin secretion from adipocytes is enhanced by thiazolidinediones (which also act to antagonize TNF‐α effects). Thus, adiponectin may be the common mechanism by which TNF‐α promotes, and the thiazolidinediones suppress, insulin resistance and inflammation. Two adiponectin receptors, termed AdipoR1 and AdipoR2, have been identified and these are ubiquitously expressed. AdipoR1 is most highly expressed in skeletal muscle and has a prominent action to activate AMPK, and hence promote lipid oxidation. AdipoR2 is most highly expressed in liver, where it enhances insulin sensitivity and reduces steatosis via activation of AMPK and increased peroxisome‐proliferator‐activated receptor α ligand activity. T‐cadherin, which is expressed in endothelium and smooth muscle, has been identified as an adiponectin‐binding protein with preference for HMW adiponectin multimers. Given the low levels of adiponectin in subjects with the metabolic syndrome, and the beneficial effect of the adipokine in animal studies, there is exciting potential for adiponectin replacement therapy in insulin resistance and related disorders.
Effect of a nutritional liquid supplement designed for the patient with diabetes mellitus (Glucerna SR) on the postprandial glucose state, insulin secretion and insulin sensitivity in healthy subjects
Authors: González‐Ortiz M. , Martínez‐Abundis E. , Hernández‐Salazar E. , Kam‐Ramos A. M. , Robles‐Cervantes J. A.
Published: March 2006

Aim:  To identify the effect of a nutritional liquid supplement designed for the patient with diabetes mellitus (Glucerna SR) in single administration on the postprandial glucose state, insulin secretion and insulin sensitivity in healthy subjects.

Methods:  A randomized, single‐blind, cross‐over, clinical trial was carried out in 14 young, healthy, non‐obese, volunteers. A basal metabolic profile, which included glucose level, insulin, total cholesterol, high‐density lipoprotein and low‐density lipoprotein cholesterol, triglycerides, creatinine, and uric acid, was measured. Subjects received a single administration of 300 kcal, gauged with water at 350 ml, of each of the following (at least 3 days apart): glucose 75 g, polymeric supplement (Ensure high calcium) 315 ml or Glucerna SR 323 ml. At the beginning of each administration and 30, 60, 90 and 120 min later, glucose and insulin concentrations were measured. Areas under the curve of glucose and insulin were calculated. First‐phase and total insulin secretions and insulin sensitivity were also estimated.

Results:  Glucose level at 120 min was significantly lower after receiving Ensure high calcium or Glucerna SR. Administration of Glucerna SR resulted in a significant reduction in the areas under the curve of glucose and insulin, as well as in total insulin secretion with a tendency to be lower in their first phase. Insulin sensitivity was increased.

Conclusions:  A single administration of Glucerna SR to healthy subjects decreased the postprandial glucose and insulin states, as well as the insulin secretion; insulin sensitivity increased.
The efficacy and tolerability of fosinopril in Chinese type 2 diabetic patients with moderate renal insufficiency
Authors: Tong P. C. Y. , Ko G. T. C. , Chan W.‐B. , Ma R. C. W. , So W.‐Y. , Lo M. K. W. , Lee K.‐F. , Ozaki R. , Chow C.‐C. , Cockram C. S. , Chan J. C. N.
Published: March 2006

Background:  The renoprotective effect of angiotensin II antagonists has been demonstrated in type 2 diabetic patients with nephropathy but similar data on angiotensin‐converting enzyme (ACE) inhibitors are limited. We examined the efficacy and tolerability of fosinopril, an ACE inhibitor with dual hepatic and renal clearance, in 38 type 2 diabetic patients with moderate renal impairment (plasma creatinine 130–300 µmol/l) over a 2‐year period.

Methods:  This was a single‐centre, randomized, double‐blinded, placebo‐controlled trial comparing fosinopril 20 mg daily vs. placebo in addition to conventional antihypertensive treatment over a 2‐year period. The primary endpoints were the rate of change and the percentage change in both 24‐h urinary albumin excretion (UAE) and creatinine clearance (CrCl).

Results:  The mean age of the patients was 65 ± 6 years (range 47–76 years, median 66 years) and plasma creatinine 190 ± 49 µmol/l. For similar blood pressure control, the percentage change of UAE in patients with microalbuminuria was greater in the fosinopril than the placebo group (−24.2 ± 28.8 vs. 11.6 ± 42.1%, p = 0.003 after adjustment for baseline covariates). In the fosinopril group, the rate of change of endogenous CrCl was slower than the placebo group (−0.07 ± 0.19 vs. −0.24 ± 0.35 ml/min/week, p = 0.026). The incidence of adverse events was similar between the two groups.

Conclusions:  Fosinopril treatment reduced albuminuria and rate of decline in renal function in type 2 diabetic patients with moderate renal insufficiency and did not increase the incidence of adverse events.
The development of the Dutch national accounts as a tool for analysis and policy
Authors: Bos Frits
Published: March 2006

Since the start of modern national accounting in the 1930s, the Netherlands has played a dominant role in the development of the national accounts. This paper discusses the origins and development of the Dutch national accounts. This includes the surprisingly slow start of political arithmetic in the Netherlands, the views of van Cleeff and Tinbergen on planning and national accounting, the role of Derksen and Oomens as fathers of the Dutch national accounts, the Dutch School of National Accounting, the interaction with national statistics and the role of the international guidelines and the European Union. The paper also takes a look into the future. The major challenges are to bridge the gap with data users and to increase relevance by, e.g. extended accounts, long‐term time series on government finance and modules on education, health care and social security.
Econometric software development: past, present and future
Authors: Ooms Marius , Doornik Jurgen A.
Published: March 2006

We give a short international history of econometric software development, with an emphasis on the origin of the main existing econometric packages. We provide a Dutch perspective on this development. We identify the characteristics of econometric software in comparison with mathematical and statistical software. Finally, a number of recent developments connected with the reuse of code across econometric softwares are discussed.
Visions of 70 years of psychometrics: the past, present, and future
Authors: Groenen Patrick J. F. , Andries van der Ark L.
Published: March 2006

Psychometrics as a separate discipline is approximately 70 years old. Over the last 60 years, there has been an active participation of Dutch researchers in psychometrics. Ten years ago, Van der Heijden and Sijtsma [Statistica Neerlandica (1996) vol. 50, pp. 111–135] described the development of Dutch psychometrics and, as a follow up, we investigated the current state of psychometrics. This study is done through a series of interviews with 12 prominent psychometricians who participated in the International Meeting of the Psychometric Society in Tilburg from July 4 to 9, 2005. Their opinions on the past and present contributions of psychometrics, and their outlook on future developments were sought.
Disequilibrium econometrics: 25 years later*
Authors: Malinvaud E.
Published: March 2006

The author concludes that disequilibrium econometrics, as it developed more than 20 years ago, is not suitable for policy analysis. Various new opportunities are outlined that can put this area on the research agenda again.
‘Rotterdam econometrics’: an analysis of publications of the Econometric Institute 1956–2004
Authors: Van Dijk H. K. , Kaashoek J. F. , Wagelmans A. P. M.
Published: March 2006

The high ranking of the Econometric Institute, as listed in recent leading scientific journals, is examined for a 50‐year period using similar standard measures. The distribution of the publications over different research areas is analyzed and a time‐series model is specified to describe and forecast the publication pattern.
The Rotterdam program in Econometrics & Management Science
Authors: Wagelmans Albert P. M.
Published: March 2006

In this paper, we sketch the main developments of the program in Econometrics & Management Science at Erasmus University Rotterdam in the past 50 years, discuss its current status and point out the main challenges for the future.
Sir Robert Walpole after his Fall from Power, 1742–1745
Authors: OATES JONATHAN
Published: March 2006

It is often assumed that Sir Robert Walpole's career in politics ended with his ceasing to be chief minister in 1742. During his remaining years, however, he continued to exert political influence by bolstering and advising the government, especially in 1743–4. Even without political office, he was still seen as the fount of patronage. He was also able to pursue his other interests in this time and enjoyed favour with both King George II and his former political colleagues. Yet his health, never good, deteriorated rapidly towards the end of 1744 and he died bravely in the spring of the following year.
Epistasis Between Type 2 Diabetes Susceptibility Loci on Chromosomes 1q21‐25 and 10q23‐26 in Northern Europeans
Authors: Wiltshire S. , Bell J. T. , Groves C. J. , Dina C. , Hattersley A. T. , Frayling T. M. , Walker M. , Hitman G. A. , Vaxillaire M. , Farrall M. , Froguel P. , McCarthy M. I.
Published: March 2006

Characterisation of the interactions between susceptibility loci (epistasis) is central to a full understanding of the genetic aetiology and the molecular pathology of complex diseases. We have examined, in British and French pedigrees, evidence for epistasis between the type 2 diabetes susceptibility loci on chromosomes 1q21‐25 and 10q23‐26 using two complementary linkage‐based approaches. Joint two‐locus linkage analysis of 1q and 10q in British pedigrees provided significant evidence for interaction (P ≤ 0.003) when comparing a general epistasis model with multiplicative or additive‐effects‐only models. Conditional linkage analysis (which models epistasis as a deviation from multiplicativity only) confirmed these findings, with significant LOD score increases at the 1q (P = 0.0002) and 10q (P = 0.0023) loci. These analyses provided sizeable reductions in the 1‐LOD support intervals for both loci. Analyses of the British and French pedigrees together yielded comparable, but not enhanced, findings, with significant (P ≤ 0.003) evidence for epistasis in joint two‐locus linkage analysis, and during conditional linkage analysis significant increases in linkage evidence at the 1q (P = 0.0002) and 10q (P = 0.0036) loci. Our findings of epistasis nevertheless substantiate the evidence for genuine genetic effects at both loci, facilitate endeavours to fine‐map these loci in population samples, and support further examination of this interaction at the nucleotide level by providing a robust prior hypothesis.
Refined Association Mapping for a Quantitative Trait: Weight in the H19‐IGF2‐INS‐TH Region
Authors: Zhang W. , Maniatis N. , Rodriguez S. , Miller G. J. , Day I. N. M. , Gaunt T. R. , Collins A. , Morton N. E.
Published: March 2006

Previous analyses have provided evidence for one or more loci affecting body weight in the H19‐IGF2‐INS‐TH region on chromosome 11p15. To identify the location of a possible causal locus or loci we applied association analysis by composite likelihood to a large cohort under the Malecot model for body weight. A random sample of 2731 men in the UK were typed for eleven single nucleotide polymorphisms (SNPs) in IGF2, two SNPs in H19, one SNP in INS and one microsatellite marker in the TH genes. Using F tests appropriate to small marker sets, the superiority of regression over correlation was confirmed. All the evidence for association came from IGF2, with P= 0.007 for height‐adjusted weight and P= 0.019 for weight additionally adjusted for smoking and alcohol drinking. Although the estimated point location for the suspected causal variant was close to IGF2 ApaI, the 95% confidence and support intervals covered most of IGF2 but none of the other loci. Identification of the causal SNP or SNPs within IGF2 will require typing of more variants in this region.
Microdialysis measures of functional increases in ACh release in the hippocampus with and without inclusion of acetylcholinesterase inhibitors in the perfusate
Authors: Chang Qing , Savage Lisa M. , Gold Paul E.
Published: March 2006

Because brain extracellular acetylcholine (ACh) levels are near detection limits in microdialysis samples, an acetylcholinesterase (AChE) inhibitor such as neostigmine is often added to microdialysis perfusates to increase ACh levels in the dialysate, a practice that raises concerns that the inhibitor might alter the results. Two experiments compared functional differences in ACh release with and without neostigmine. In the first experiment, 30–60% increases in extracellular ACh concentrations in the hippocampus were evident during food‐rewarded T‐maze training with 20–500 nm neostigmine in the perfusate but no increases were seen without neostigmine. In the second experiment, 78% increases in ACh release in the hippocampus were seen after injections of the GABAA receptor antagonist, bicuculline, into medial septum only if neostigmine (50 nm) was included in the perfusate. These findings suggest that, in the hippocampus, endogenous brain AChEs are very efficient at removing extracellular ACh, obscuring differences in ACh release in these experiments. Therefore, inclusion of AChE inhibitors in the microdialysis perfusate may be necessary under some conditions for observations of functional changes in release of ACh in the hippocampus.
Nitric oxide inhibits mitochondrial movement in forebrain neurons associated with disruption of mitochondrial membrane potential
Authors: Rintoul Gordon L. , Bennett Vicki J. , Papaconstandinou Natalia A. , Reynolds Ian J.
Published: March 2006

Nitric oxide (NO) has a number of physiological and pathophysiological effects in the nervous system. One target of NO is the mitochondrion, where it inhibits respiration and ATP synthesis, which may contribute to NO‐mediated neuronal injury. Our recent studies suggested that impaired mitochondrial function impairs mitochondrial trafficking, which could also contribute to neuronal injury. Here, we studied the effects of NO on mitochondrial movement and morphology in primary cultures of forebrain neurons using a mitochondrially targeted enhanced yellow fluorescent protein. NO produced by two NO donors, papa non‐oate and diethylamine/NO complex, caused a rapid cessation of mitochondrial movement but did not alter morphology. Movement recovered after removal of NO. The effects of NO on movement were associated with dissipation of the mitochondrial membrane potential. Increasing cGMP levels using 8‐bromoguanosine 3′,5′‐cyclic monophosphate, did not mimic the effects on mitochondrial movement. Furthermore, 1H‐[1,2,4]oxadiazolo[4,3‐a]quinoxalin‐1‐one (ODQ), an inhibitor of NO‐induced activation of soluble guanylate cyclase, did not block the effects of NO. Thus, neither increasing nor decreasing cGMP levels had an effect on mitochondrial movement. Based on these data, we conclude that NO is a novel modulator of mitochondrial trafficking in neurons, which may act through the inhibition of mitochondrial function.
Effects of Compensation Methods and Physician Group Structure on Physicians' Perceived Incentives to Alter Services to Patients
Authors: Reschovsky James D. , Hadley Jack , Landon Bruce E.
Published: March 2006

Objective. To examine how health plan payment, group ownership, compensation methods, and other practice management tools affect physician perceptions of whether their overall financial incentives tilt toward increasing or decreasing services to patients.

Data Source. Nationally representative data on physicians are from the 2000–2001 Community Tracking Study Physician Survey (N=12,406).

Study Design. Ordered and multinomial logistic regression were used to explore how physician, group, and market characteristics are associated with physician reports of whether overall financial incentives are to increase services, decrease services, or neither.

Principal Findings. Seven percent of physicians report financial incentives are to reduce services to patients, whereas 23 percent report incentives to increase services. Reported incentives to reduce services were associated with reports of lower ability to provide quality care. Group revenue in the form of capitation was associated with incentives to reduce services whereas practice ownership and variable compensation and bonuses for employee physicians were mostly associated with incentives to increase services to patients. Full ownership of groups, productivity incentives, and perceived competitive markets for patients were associated with incentives to both increase and reduce services.

Conclusions. Practice ownership and the ways physicians are compensated affect their perceived incentives to increase or decrease services to patients. In the latter case, this adversely affects perceived quality of care and satisfaction, although incentives to increase services may also have adverse implications for quality, cost, and insurance coverage.
Development of an Easy‐to‐Use Spanish Health Literacy Test
Authors: Lee Shoou‐Yih D. , Bender Deborah E. , Ruiz Rafael E. , Cho Young Ik
Published: March 2006

Objective. The study was intended to develop and validate a health literacy test, termed the Short Assessment of Health Literacy for Spanish‐speaking Adults (SAHLSA), for the Spanish‐speaking population.

Study Design. The design of SAHLSA was based on the Rapid Estimate of Adult Literacy in Medicine (REALM), known as the most easily administered tool for assessing health literacy in English. In addition to the word recognition test in REALM, SAHLSA incorporates a comprehension test using multiple‐choice questions designed by an expert panel.

Data Collection. Validation of SAHLSA involved testing and comparing the tool with other health literacy instruments in a sample of 201 Spanish‐speaking and 202 English‐speaking subjects recruited from the Ambulatory Care Center at UNC Health Care.

Principal Findings. With only the word recognition test, REALM could not differentiate the level of health literacy in Spanish. The SAHLSA significantly improved the differentiation. Item response theory analysis was performed to calibrate the SAHLSA and reduce the instrument to 50 items. The resulting instrument, SAHLSA‐50, was correlated with the Test of Functional Health Literacy in Adults, another health literacy instrument, at r=0.65. The SAHLSA‐50 score was significantly and positively associated with the physical health status of Spanish‐speaking subjects (p<.05), holding constant age and years of education. The instrument displayed good internal reliability (Cronbach's α=0.92) and test–retest reliability (Pearson's r=0.86).

Conclusions. The new instrument, SAHLSA‐50, has good reliability and validity. It could be used in the clinical or community setting to screen for low health literacy among Spanish speakers.
Rural Residents with Disabilities Confront Substantial Barriers to Obtaining Primary Care
Authors: Iezzoni Lisa I. , Killeen Mary B. , O'Day Bonnie L.
Published: March 2006

Objective.To learn about the health care experiences of rural residents with disabilities.

Study Setting.Rural areas in Massachusetts and Virginia.

Study Design.Local centers for independent living recruited 35 adults with sensory, physical, or psychiatric disabilities to participate in four focus group interviews.

Data Collection Methods.Verbatim transcripts of interviews were reviewed to identify major themes.

Principal Findings.Interviewees described the many well‐recognized impediments to health care in rural America; disability appears to exacerbate these barriers. Interviewees reported substantial difficulties finding physicians who understand their disabilities and sometimes feel that they must teach their local doctors about their underlying conditions. Interviewees described needing to travel periodically to large medical centers to get necessary specialty care. Many are poor and are either uninsured or have Medicaid coverage, complicating their searches for willing primary care physicians. Because many cannot drive, they face great difficulties getting to their local doctor and especially making long trips to urban centers. Available public transportation often is inaccessible and unreliable. Physicians' offices are sometimes located in old buildings that do not have accessible entrances or equipment. Based on their personal experiences, interviewees perceive that rural areas are generally less sensitive to disability access issues than urban areas.

Conclusions.Meeting the health care needs of rural residents with disabilities will require interventions beyond health care, involving transportation and access issues more broadly.
Referrals to High‐Quality Cardiac Surgeons: Patients' Race and Characteristics of Their Physicians
Authors: Mukamel Dana B. , Weimer David L. , Mushlin Alvin I.
Published: March 2006

Objective. To examine the referral process to cardiac surgeons in order to explain racial disparities in access to high‐quality cardiac surgeons.

Data Sources/Study Settings. All white and black Medicare fee‐for‐service patients undergoing coronary artery bypass graft (CABG) surgery in New York State during 1997–1999.

Study Design. A retrospective analysis of referral patterns for white and black patients in relation to the quality of the cardiac surgeon, measured by the surgeon's risk‐adjusted mortality rate (RAMR), and in relation to characteristics of the physician providing the majority of cardiac care before the surgery. The average RAMRs of the surgeons to whom different physicians referred patients were compared using t‐tests and paired t‐tests. A hierarchical multivariate regression model was estimated to test hypotheses about the effect of physicians' characteristics on referrals of blacks to low‐quality surgeons.

Data Extraction Method. Variables were constructed from Medicare claims.

Principal Findings. The differential in surgeons' quality for white and black patients is partially due to the physician providing the majority of cardiac care before the surgery. There is both across‐ and within‐physician variation in referrals. Of the physician characteristics investigated, only the number of black patients referred to CABG and the percent of all cardiac referrals to the same hospital decrease the difference in surgeons' quality between whites and blacks.

Conclusions. Several different pathways lead blacks to cardiac surgeons of lower quality. Further research is needed to understand the causes and inform policies designed to minimize disparities in access to high‐quality providers.
State Regulation and the Delivery of Physical Therapy Services
Authors: Resnik Linda , Feng Zhanlian , Hart Dennis L.
Published: March 2006

Objective.The study purpose was to examine the relationship between state regulations of physical therapists (PT) and three dependent variables: physical therapist assistant (PTA) utilization more than 50 percent of the time during the treatment episode (high PTA utilization), number of visits, and patient self‐reported functional health status (FHS) at discharge. We evaluated regulations governing licensure of PTAs, PT/PTA ratio, frequency of PT re‐evaluation, and PTA supervision.

Data Source.The analytic sample included 63,900 patients from 38 states drawn from 395 clinics who participated in the Focus on Therapeutic Outcomes Inc. (Knoxville, TN) database in 2000 and 2001.

Study Design.Using a Bayesian modeling approach with the Markov Chain Monte Carlo estimation method, we fitted separate multilevel multivariate regression models predicting high PTA utilization, number of visits, and discharge FHS.

Data Collection Methods.Patients completed FHS surveys at intake and discharge. Clinicians recorded the number of visits and percentage of time a patient spent with each provider.

Principal Findings.After controlling for patient, therapist, and clinic characteristics, the presence of state regulations regarding PTA supervision was not associated with the likelihood of high PTA utilization. High PTA utilization and regulations requiring full‐time onsite supervision were associated with more visits, whereas regulation of PT/PTA ratio was associated with fewer visits. Supervisory regulations were associated with better discharge FHS. High PTA utilization and use of therapy aides were associated with more visits per episode and lower discharge FHS.

Conclusions.The use of care extenders in place of PTs is likely to result in less efficient and lower quality care in outpatient rehabilitation.
The Utility of Clinical Features in Patients Presenting With Nontraumatic Headache: An Investigation of Adult Patients Attending an Emergency Department
Authors: Locker Thomas E , Thompson Catriona , Rylance Jamie , Mason Suzanne M
Published: March 2006

Objective.—When patients present to an emergency department because of nontraumatic headache, they often present a diagnostic challenge. This study aimed to examine the utility of clinical features in detecting serious underlying causes of nontraumatic headache in adult patients presenting to an emergency department.

Methods.—A prospective observational study of alert adult patients presenting to 1 UK emergency department over a period of 14 months was conducted. Patients were excluded if their headache was related to trauma or they had been previously recruited into the study. A standardized data collection form was used to record details of the history and examination findings. Investigation and management were conducted according to the existing departmental protocols. Patients were followed up for 3 months following their initial presentation. Each factor in the history and examination was examined for its ability to predict a serious underlying cause of headache.

Results.—Five hundred and eighty‐nine patients were included in the study with complete follow‐up details obtained on 558 (94.7%) patients. Seventy‐five (13.4%) patients were found to have a serious pathological cause of their headache. Four features were found to be significant independent predictors of serious pathology, these were age >50 years (likelihood ratio (LR) = 2.34), sudden onset, (LR = 1.74), any abnormality on neurological examination (LR = 3.56), and presentation due to associated features (LR = 2.27). Taken in combination, the presence of any 1 of the first 3 features has a sensitivity of 98.6% and specificity of 34.4% (Positive LR = 1.50, Negative LR = 0.04).

Conclusion.—Three features, age greater than 50, sudden onset, and an abnormal neurological examination, are identified as significant independent predictors of serious pathology, which, in combination, can exclude the presence of such pathology in adult patients presenting with nontraumatic headache.
Effects of Energy Drink Ingestion on Alcohol Intoxication
Authors: Ferreira Sionaldo Eduardo , De Mello Marco Túlio , Pompéia Sabine , De Souza‐Formigoni Maria Lucia Oliveira
Published: March 2006

Background: Well‐known reports suggest that the use of energy drinks might reduce the intensity of the depressant effects of alcohol. However, there is little scientific evidence to support this hypothesis.

Objective and Methods: The present study aimed at evaluating the effects of the simultaneous ingestion of an alcohol (vodka37.5%v/v) and an energy drink (Red Bull®—3.57 mL/kg), compared with those presented after the ingestion of an alcohol or an energy drink alone. Twenty‐six young healthy volunteers were randomly assigned to 2 groups that received 0.6 or 1.0 g/kg alcohol, respectively. They all completed 3 experimental sessions in random order, 7 days apart: alcohol alone, energy drink alone, or alcohol plus energy drink. We evaluated the volunteers' breath alcohol concentration, subjective sensations of intoxication, objective effects on their motor coordination, and visual reaction time.

Results: When compared with the ingestion of alcohol alone, the ingestion of alcohol plus energy drink significantly reduced subjects' perception of headache, weakness, dry mouth, and impairment of motor coordination. However, the ingestion of the energy drink did not significantly reduce the deficits caused by alcohol on objective motor coordination and visual reaction time. The ingestion of the energy drink did not alter the breath alcohol concentration in either group.

Conclusions: Even though the subjective perceptions of some symptoms of alcohol intoxication were less intense after the combined ingestion of the alcohol plus energy drink, these effects were not detected in objective measures of motor coordination and visual reaction time, as well as on the breath alcohol concentration.
Proposal Rights and Political Power
Authors: Kalandrakis Tasos
Published: March 2006

In a canonical model of sequential collective bargaining over a divisible good we show that equilibrium expected payoffs are not restricted by players' voting rights or their impatience. For all monotonic voting rules and discount factors, and for all divisions of the good among players, there exists a stationary proposal‐making rule such that this division represents players' expected payoffs in a Stationary Subgame Perfect Nash equilibrium in pure strategies. The result highlights the significance of proposal rights in determining political power in collective deliberations.
Policy, technology, and management strategies for achieving sustainable agricultural intensification
Authors: Lee David R. , Barrett Christopher B. , McPeak John G.
Published: March 2006

Considerable agreement exists among researchers, development practitioners, and policymakers regarding the goals of sustainable agricultural intensification (SAI). They include: achieving agricultural productivity growth, household food security, and improved rural livelihoods and employment, while simultaneously mitigating environmental degradation. However, the multiplicity of these objectives, as well as the choice of approaches to achieving them and the site‐ and context‐specificity of specific technological and institutional interventions, assures that the research and policy challenges to achieving SAI will remain considerable. This article summarizes the contributions of the articles in this Special Issue in four areas of the literature. First, labor market constraints, the labor intensity of specific agricultural technologies and practices, and labor's substitutability, or complementarity, with other inputs are shown to widely influence their viability and related input efficiencies. Second, the articles identify specific tradeoffs and synergistic relationships that arise in the attainment of these multiple goals stemming from technologies, management practices, and policies introduced under specific agroclimatic, market, and institutional conditions. Third, these papers contribute to the literature on agricultural technology adoption by furnishing additional empirical evidence on the determinants and effects of investment behavior and adoption of specific technologies and management practices. Finally, the articles in this Special Issue emphasize that there is no single policy nor technological, management, or institutional innovation that unambiguously promotes SAI. Preferred policies must be contextualized and sensitive to initial biophysical, market, and institutional conditions.
Deprived land‐use intensification in shifting cultivation: the population pressure hypothesis revisited
Authors: Pascual Unai , Barbier Edward B.
Published: March 2006

This article provides a theoretical framework, based on optimal control theory, to analyze farm households' land‐use intensification decisions in forest‐based shifting cultivation (slash‐and‐burn) agroecosystems. The main results from the analysis generally coincide with the “Population Pressure Hypothesis” (PPH) as an important driver of soil degradation due to the so‐called “fallow crisis” or “deprived land‐use intensification” in shifting cultivation. However, the model also shows, from a supply perspective, that such a vicious circle of lower yields and greater forest land clearing may be avoided when the production elasticity of on‐farm labor outweighs the elasticity of substitution between farm labor and soil fertility. Furthermore, using data from shifting cultivating households from Yucatán, Mexico, we calibrate the effect of changes in population density. The numerical analysis suggests that by contrast to better‐off households, when population density increases, poorer shifting cultivating households' optimal labor allocation strategy is to further extensify land use by clearing more forest in the village common property land, or ejido land.
Strategies for sustainable intensification in East African highlands: labor use and input efficiency
Authors: Ruben Ruerd , Kruseman Gideon , Kuyvenhoven Arie
Published: March 2006

Strategies for poverty alleviation and sustainable natural resource management usually focus on land use options for improving yields. Increasing the returns to critical factors requires possibilities for input substitution. Inadequate timing of input applications or nonavailability of complementary factors can seriously hinder this substitution. Such constraints particularly apply in less‐favored areas where soil organic matter content is too low for enabling efficient nutrient uptake and soil structure limits water infiltration and moisture retention.

This article focuses attention on the importance of labor for crop management activities and input applications that enhance input efficiency in highland area cropping systems of Northern Ethiopia. Given the inherent complementarities between labor and nutrient supply during critical phases of the plant growth process, input efficiency strongly depends on labor use. We present a semiparametric bioeconomic modeling approach to analyze the available options for improving input efficiency in agricultural production. Input response equations are used that consider the returns per unit of land and labor as a function of specific combinations of material inputs and management practices. Critical trade‐offs may arise when opportunity costs for labor are considered or when complementary factors appear as binding constraints. The model enables assessment of feasible pathways for enhancing sustainable intensification and poverty alleviation in typical settings of the East African highland region.