bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dissociated incretin response to oral glucose at 1 year after restrictive vs. malabsorptive bariatric surgery
Authors: Guldstrand M. , Ahrén B. , Näslund E. , Holst J. J. , Adamson U. 
Published: July 2009

Aim: Compare the response to oral glucose of the two incretin hormones, glucose‐dependent insulinotropic polypeptide (GIP) and glucagon‐like peptide‐1 (GLP‐1) at 1 year after restrictive vs. malabsorptive bariatric surgery.Methods: Vertical banded gastroplasty (VBG, n = 7) or jejunoileal bypass (JIB, n = 5) was performed in 12 women, aged 26–39 years, with severe obesity [body mass index (BMI) 46.6 ± 2.3 kg/m2]. After 1 year, 75 g glucose was administered and plasma levels of glucose, insulin, GIP and GLP‐1 were determined regularly during the following 2 h.Results: At 1 year after operation, reduction in body weight, actual body weight, fasting glucose or insulin, or the glucose and insulin responses to oral glucose did not differ significantly between the groups. Similarly, fasting GIP and GLP‐1 levels did not differ significantly between the groups. In contrast, the GIP and GLP‐1 responses to oral glucose were different between the groups in a dissociated pattern. Thus, AUCGIP was significantly higher after VBG than after JIB (53 ± 8 vs. 26 ± 6 pmol/l/min, p = 0.003). In contrast, AUCGLP−1 was significantly higher after JIB than after VBG (49 ± 5 vs. 20 ± 3 pmol/l/min, p = 0.007).Conclusions: We conclude that at 1 year after bariatric surgery, the two incretins show dissociated responses in that the GIP secretion is higher after VBG whereas GLP‐1 secretion is higher after JIB. This dissociated incretin response is independent from reduction in body weight, glucose tolerance or insulin secretion.
State‐conditional Fertilizer Yield Response on Western Kenyan Farms
Authors: Marenya Paswel P. , Barrett Christopher B. 
Published: July 2009

AbstractFertilizer interventions have attained prominence in rural poverty reduction programs in Africa. Using data from maize plots operated by small farmers in western Kenya, we find a von Liebig‐type relationship between soil organic matter (SOM) and maize yield response to nitrogen application. Low SOM commonly limits the yield response to mineral fertilizer application. Although fertilizer is, on average, profitable in our sample, on roughly one‐third of the plots degraded soils limit the marginal productivity of fertilizer such that it becomes unprofitable at prevailing prices. Moreover, because poorer farmers most commonly cultivate soils deficient in SOM, fertilizer interventions might be less pro‐poor than is widely assumed and may instead reinforce ex ante income inequality.
Consumer and Market Responses to Mad Cow Disease
Authors: Schlenker Wolfram , Villas‐Boas Sofia B. 
Published: July 2009

AbstractWe examine how consumers and financial markets in the United States reacted to two health warnings about mad cow disease: the first discovery of an infected cow in December 2003 and an Oprah Winfrey show that aired seven years earlier on the potentially harmful effects of mad cow disease. We find a pronounced and significant reduction in beef sales following the first discovery of an infected cow in a product‐level scanner data set of a national grocery chain. Cattle futures show a pattern of abnormal price drops comparable to the scanner data. Contracts with longer maturity show smaller drops, suggesting that the market anticipated the impact to be transitory. Cattle futures show abnormal price drops after the Oprah Winfrey show that are more than 50% of the drop following the 2003 discovery of an infected cow.
Finding Missing Markets (and a Disturbing Epilogue): Evidence from an Export Crop Adoption and Marketing Intervention in Kenya
Authors: Ashraf Nava , Giné Xavier , Karlan Dean 
Published: July 2009

AbstractFarmers may grow crops for local consumption despite more profitable export options. DrumNet, a Kenyan NGO that helps small farmers adopt and market export crops, conducted a randomized trial to evaluate its impact. DrumNet services increased production of export crops and lowered marketing costs, leading to a 32% income gain for new adopters. The services collapsed one year later when the exporter stopped buying from DrumNet because farmers could not meet new EU production requirements. Farmers sold to other middlemen and defaulted on their loans from DrumNet. Such experiences may explain why farmers are less likely to adopt export crops.
Export Sectors and Rural Development
Authors: Kilkenny Maureen , Partridge Mark D. 
Published: July 2009

AbstractThe export base hypothesis is that a region's growth is led by export demand, given perfectly elastic factor supplies. It is a rationale for “sector‐based” rural development policies, and it is formalized by input‐output models. But it is contested by modern trade, migration, and growth theories, and there is little research about its empirical relevance. We investigate the hypothesis for contemporary U.S. rural development by estimating the influence of export sector employment on subsequent rural development outcomes. The results reject the hypothesis that emphasizing traditional export employment results in rural growth, reject the assumption of perfectly elastic factor supply, and support alternative explanations.
Farmers’ Subjective Valuation of Subsistence Crops: The Case of Traditional Maize in Mexico
Authors: Arslan Aslihan , Taylor J. Edward 
Published: July 2009

AbstractShadow prices guide farmers’ resource allocations, but for subsistence farmers who grow traditional crops they may bear little relationship with market prices. We theoretically derive shadow prices for a subsistence crop with nonmarket value, then estimate shadow prices of maize using data from a nationally representative survey of rural households in Mexico. Shadow prices are significantly higher than market prices for traditional but not improved maize varieties. They are particularly high in the indigenous areas of southern and southeastern Mexico, indicating large de facto incentives to maintain traditional varieties there.
The Impact of Agricultural Extension and Roads on Poverty and Consumption Growth in Fifteen Ethiopian Villages
Authors: Dercon Stefan , Gilligan Daniel O. , Hoddinott John , Woldehanna Tassew 
Published: July 2009

AbstractThis article investigates whether public investments that led to improvements in road quality and increased access to agricultural extension services led to faster consumption growth and lower rates of poverty in rural Ethiopia. Estimating an Instrumental Variables model using Generalized Methods of Moments and controlling for household fixed effects, we find evidence of positive impacts with meaningful magnitudes. Receiving at least one extension visit reduces headcount poverty by 9.8 percentage points and increases consumption growth by 7.1 percentage points. Access to all‐weather roads reduces poverty by 6.9 percentage points and increases consumption growth by 16.3 percentage points. These results are robust to changes in model specification and estimation methods.
Growth rate as a prognostic factor in localized invasive cutaneous melanoma
Authors: Tejera‐Vaquerizo A , Barrera‐Vigo MV , López‐Navarro N , Herrera‐Ceballos E 
Published: July 2009

AbstractBackground  Melanoma is a tumour with a very variable progression. Whilst some melanomas grow slowly over many years, others can reach several millimetres in thickness in just a few weeks. Since melanoma is a visible superficial tumour, the information obtained from the clinical interview may be of use to calculate the speed of growth of the melanoma.Objective  This study aims to assess the growth rate (GR) of melanomas and the association of this GR with various clinical and pathological factors and their usefulness as prognostic markers for localized invasive cutaneous melanomas.Methods  The GR of melanomas was calculated as the ratio of tumour thickness to time of development, as obtained from the clinical history (in millimetres per month).Results  Applying the GR calculation to patients with a localized melanoma showed a significant association between melanomas with a GR greater than 0.4 mm per month and an age of 65 years or over, male sex, nodular melanoma, tumour thickness, level of invasion, the presence of ulceration and a high mitotic index. As an independent prognostic factor for overall survival, the GR proved to be significant (P = 0.024).Conclusion  The GR of localized cutaneous melanomas may be a possible prognostic factor for survival. Additionally, rapid GR is associated with male patients more advanced in age at diagnosis, which suggests the need to assess new strategies for the early detection of these melanomas.
Impact of Financial Incentives for Prenatal Care on Birth Outcomes and Spending
Authors: Rosenthal Meredith B. , Li Zhonghe , Robertson Audra D. , Milstein Arnold 
Published: July 2009

Objective. To evaluate the impact of offering US$100 each to patients and their obstetricians or midwives for timely and comprehensive prenatal care on low birth weight, neonatal intensive care admissions, and total pediatric health care spending in the first year of life.Data Sources/Study Setting. Claims and enrollment profiles of the predominantly low‐income and Hispanic participants of a union‐sponsored, health insurance plan from 1998 to 2001.Study Design. Panel data analysis of outcomes and spending for participants and nonparticipants using instrumental variables to account for selection bias.Data Collection/Abstraction Methods. Data provided were analyzed using t‐tests and chi‐squared tests to compare maternal characteristics and birth outcomes for incentive program participants and nonparticipants, with and without instrumental variables to address selection bias. Adjusted variables were analyzed using logistic regression models.Principle Findings. Participation in the incentive program was significantly associated with lower odds of neonatal intensive care unit admission (0.45; 95 percent CI, 0.23–0.88) and spending in the first year of life (estimated elasticity of −0.07; 95 percent CI, −0.12 to −0.01), but not low birth weight (0.53; 95 percent CI, 0.23–1.18).Conclusion. The use of patient and physician incentives may be an effective mechanism for improving use of recommended prenatal care and associated outcomes, particularly among low‐income women.
Community Demographics and Access to Health Care among U.S. Hispanics
Authors: Gresenz Carole Roan , Rogowski Jeannette , Escarce José J. 
Published: July 2009

Objective.To explore the influence of the communities in which Hispanics live on their access to health care.Data.1996–2002 Medical Expenditure Panel Survey data, linked to secondary data sources and including 14,504 observations from 8,371 Mexican American respondents living in metropolitan areas.Study Design.We use multivariate probit regression models, stratified by individuals' insurance status, for analyses of four dependent variables measuring access to health care. We measure community characteristics at the zip code tabulation area level, and key independent variables of interest are the percentage of the population that speaks Spanish and percentage of the population that is immigrant Hispanic. Each of these measures is interacted with individual‐level measures of nativity and length of U.S. residency.Principal Findings.For Mexican American immigrants, living in an area populated by relatively more Spanish speakers or more Hispanic immigrants is associated with better access to care. The associations are generally stronger for more recent immigrants compared with those who are better established. Among U.S.‐born Mexican Americans who are uninsured, living in areas more heavily populated with Spanish‐speaking immigrants is negatively associated with access to care.Conclusions.The results suggest that characteristics of the local population, including language and nativity, play an important role in access to health care among U.S. Hispanics, and point to the need for further study, including analyses of other racial and ethnic groups, using different geographic constructs for describing the local population, and, to the extent possible, more specific exploration of the mechanisms through which these characteristics may influence access to care.
Development and Validation of a Risk‐Adjustment Tool in Acute Asthma
Authors: Tsai Chu‐Lin , Clark Sunday , Sullivan Ashley F. , Camargo, Jr Carlos A. 
Published: July 2009

Objective. To develop and prospectively validate a risk‐adjustment tool in acute asthma.Data Sources. Data were obtained from two large studies on acute asthma, the Multicenter Airway Research Collaboration (MARC) and the National Emergency Department Safety Study (NEDSS) cohorts. Both studies involved >60 emergency departments (EDs) and were performed during 1996–2001 and 2003–2006, respectively. Both included patients aged 18–54 years presenting to the ED with acute asthma.Study Design. Retrospective cohort studies.Data Collection. Clinical information was obtained from medical record review. The risk index was derived in the MARC cohort and then was prospectively validated in the NEDSS cohort.Principle Findings. There were 3,515 patients in the derivation cohort and 3,986 in the validation cohort. The risk index included nine variables (age, sex, current smoker, ever admitted for asthma, ever intubated for asthma, duration of symptoms, respiratory rate, peak expiratory flow, and number of beta‐agonist treatments) and showed satisfactory discrimination (area under the receiver operating characteristic curve, 0.75) and calibration ( p=.30 for Hosmer–Lemeshow test) when applied to the validation cohort.Conclusions. We developed and validated a novel risk‐adjustment tool in acute asthma. This tool can be used for health care provider profiling to identify outliers for quality improvement purposes.
Luminescence dating of Holocene spit deposits: An example from Skagen Odde, Denmark
Authors: CLEMMENSEN LARS B. , MURRAY ANDREW S. 
Published: July 2009

Clemmensen, L. B. & Murray, A. S. 2009: Luminescence dating of Holocene spit deposits: An example from Skagen Odde, Denmark. Boreas, 10.1111/j.1502‐3885.2009.00110.x. ISSN 0300‐9483.Skagen Odde is a large, active spit system in northern Denmark that started to form about 7200 years ago. Models for spit growth have usually relied on radiocarbon‐dating of swale peat (Martørv). In this study, we date the spit deposits at three sites directly using Optically Stimulated Luminescence (OSL) to obtain supplementary age control on spit development. The spit deposits consist of a lowermost succession of shoreface, beach and backshore aeolian deposits topped by a swale peat and followed by an uppermost succession of aeolian sand sheet and dune deposits. The ages of the shallow marine, beach and backshore aeolian deposits at the main study site are indistinguishable, implying good resetting of the shallow marine deposits; the average age of 4640±250 years compares well with earlier model predictions based on radiocarbon‐dating of swale peat. Aeolian sand extracted from the uppermost part of the swale peat at this site provides OSL ages of between 1600 and 2500 years, in good agreement with a calibrated AMS age from the same level of 2330–2200 years. The uppermost aeolian succession consists of two units separated by a thin palaeosol, and the aeolian units have OSL ages of about 1500 years and younger than 130 years. Lowermost spit deposits at the two additional sites have average ages of 5010±240 and 3730±190, respectively, supporting the existing chronology for spit growth based on radiocarbon‐dating.
Nonlinear Cointegration Relationships Between Non‐Life Insurance Premiums and Financial Markets
Authors: Jawadi Fredj , Bruneau Catherine , Sghaier Nadia 
Published: July 2009

AbstractThe aim of this article is to study the adjustment dynamics of the non‐life insurance premium (NLIP) and test its dependence to the financial markets in five countries (Canada, France, Japan, the United Kingdom, and the United States). First, we justify the linkage between the insurance and the financial markets by the underwriting cycle theory and financial models of insurance pricing. Second, we examine the relationship between the NLIP, the interest rate, and the stock price using the recent developments of nonlinear econometrics. We use threshold cointegration models: the switching transition error correction models (STECM). We show that STECM perform better than a linear error correction model (LECM) to reproduce the NLIP dynamics. Our empirical results show that the adjustment of the NLIP in France, Japan, and the United States is rather discontinuous, asymmetrical, and nonlinear. Moreover, we suggest a strong evidence of significant linkages between insurance and financial markets, show two regimes for the NLIP, and find that the NLIP adjustment toward equilibrium is time varying with a convergence speed that varies according to the insurance disequilibrium size.
Optimal Reinsurance Arrangements Under Tail Risk Measures
Authors: Bernard Carole , Tian Weidong 
Published: July 2009

AbstractRegulatory authorities demand insurance companies control their risk exposure by imposing stringent risk management policies. This article investigates the optimal risk management strategy of an insurance company subject to regulatory constraints. We provide optimal reinsurance contracts under different tail risk measures and analyze the impact of regulators' requirements on risk sharing in the reinsurance market. Our results underpin adverse incentives for the insurer when compulsory Value‐at‐Risk risk management requirements are imposed. But economic effects may vary when regulatory constraints involve other risk measures. Finally, we compare the obtained optimal designs to existing reinsurance contracts and alternative risk transfer mechanisms on the capital market.
Percutaneous Microwave Ablation with a Long Side‐Firing Antenna Array Can Successfully Treat a Nonsurgical Chronic Ovine Atrial Flutter Model
Authors: LIM TOON WEI , CLOUT RAY , BARRY MICHAEL A. , LU JUNTANG , HUANG KAIMIN , THOMAS STUART P. 
Published: July 2009

Introduction:Long side‐firing microwave (MW) arrays can deliver energy uniformly over its length without the need for intimate endocardial contact. We hypothesize that a novel 6 Fr 20 mm long percutaneous high‐efficiency MW antenna array ablation catheter can rapidly create long, continuous, and transmural linear ablation lesions.Methods and Results:Cavotricuspid isthmus (CTI)‐dependent atrial flutter (AFL) was created in 11 sheep by a line of radiofrequency ablation lesions in the posterior right atrium (RA) linking the venae cavae. After 4–6 weeks recovery, CTI‐dependent AFL was still inducible in all 11 sheep (cycle length 178 ± 13 ms). MW ablation of the CTI at 100 W for 30 seconds was then performed with an endpoint of AFL noninducibility. AFL was not inducible in all 11 sheep after 4.3 ± 3.3 MW applications (129 ± 99 seconds). The last 6 animals needed fewer ablations (2.2 ± 1.5) and 3 of these sheep required only a single ablation. Although conduction times from proximal coronary sinus to lateral RA and vice versa increased postablation (51 ± 14 ms to 118 ± 31 ms [P = 0.0002] and 60 ± 13 ms to 119 ± 28 ms [P = 0.0001], respectively), AFL was still inducible in 2 sheep and further ablation was needed to reach the endpoint.Conclusions:High‐efficiency side‐firing MW array ablation can rapidly create long linear and electrically intact lesions in an ovine AFL model. AFL noninducibility may be a more reliable indicator than CTI conduction times of an intact line of ablation in this animal model.
The Impact of Left Atrial Size on Long‐Term Outcome of Catheter Ablation of Chronic Atrial Fibrillation
Authors: LO LI‐WEI , LIN YENN‐JIANG , TSAO HSUAN‐MING , CHANG SHIH‐LIN , UDYAVAR AMEYA R. , HU YU‐FENG , UENG KWO‐CHANG , TSAI WEN‐CHIN , TUAN TA‐CHUN , CHANG CHIEN‐JUNG , TANG WEI‐HUA , HIGA SATOSHI , TAI CHING‐TAI , CHEN SHIH‐ANN 
Published: July 2009

Background: The left atrial (LA) size is an important predictor of atrial fibrillation (AF) procedural termination and the long‐term outcome. We sought to evaluate the long‐term outcome in regard to the LA size and procedural termination. Methods: Eighty‐seven consecutive chronic AF patients (72 males, 53 ± 10 years) underwent 3D mapping (NavX) and ablation. A stepwise approach including circumferential pulmonary vein (PV) isolation, linear ablation, and continuous complex‐fractionated electrogram (CFE) ablation (targeting fractionation intervals of < 50 ms). Electrical cardioversion was applied to those without any procedural termination. The freedom from AF was defined as the maintenance of sinus rhythm without the use of any class I or III antiarrhythmic drugs after the blanking period. Results: Among the 87 patients, all received a circumferential PV isolation, 93% a linear ablation, and 59% a continuous CFE ablation. Those with AF procedural termination (n = 30) had a better long‐term outcome when compared with those without termination during a follow‐up of 21 ± 12 months. Moreover, a Kaplan‐Meier analysis showed that in those with an LA diameter of less than 45 mm (n = 49), the freedom from AF rate was higher when procedural termination was achieved (P = 0.004). On the contrary, the outcome was comparable in those with an LA diameter of ≥ 45 mm (n = 38), whether AF procedural termination occurred or not (P = 0.658). Conclusions: AF procedural termination was related to the long‐term success during chronic AF ablation, especially in those with an LA diameter of less than 45 mm. The favorable effect of termination decreased when the LA diameter was ≥ 45 mm.
Synergistic effect of insect herbivory and plant parasitism on the performance of the invasive tree Schinus terebinthifolius
Authors: Manrique Veronica , Cuda J. P. , Overholt W. A. , Ewe S. M. L. 
Published: July 2009

Abstract Schinus terebinthifolius Raddi (Anacardiaceae) is an introduced tree from South America that has invaded many ecosystems throughout central and south Florida, USA. Exploratory surveys in the plant’s native range identified several potential biocontrol agents, including the leaflet rolling moth, Episimus unguiculus Clarke (Lepidoptera: Tortricidae). The larval stages of E. unguiculus tie together the plant leaflets while feeding and can completely defoliate small plants. The native love vine, Cassytha filiformis L. (Lauraceae), has been found parasitizing S. terebinthifolius in Florida. Natural processes such as plant parasitism may be one of the components of an integrated approach for S. terebinthifolius management in Florida. Thus, the objective of this study was to evaluate the combined effects of insect herbivory and plant parasitism on the performance of S. terebinthifolius. A factorial design experiment was conducted in the greenhouse to determine the effect of C. filiformis parasitism and E. unguiculus feeding damage on the growth and biomass of S. terebinthifolius. Results showed that plant parameters, including leaflet biomass, growth rate, and flower production, were negatively affected by plant parasitism and insect herbivory. Moreover, the decrease in S. terebinthifolius performance was greater when these two factors were combined, indicative of a synergistic relationship. In addition, the combined effect of C. filiformis and E. unguiculus suppressed plant performance for at least 2 months after the moths were removed. Therefore, increased control of S. terebinthifolius stands may be achieved in those areas where C. filiformis is present in Florida (e.g., pinelands, hammock forests) if the biocontrol agent E. unguiculus is approved for release.