bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vegetation and seedbank response to Eragrostis lehmanniana removal in semi‐desert communities
Authors: CRIMMINS T M , McPHERSON G R 
Published: November 2008

Summary Eragrostis lehmanniana (Lehmann lovegrass) is an invasive perennial bunchgrass in semi‐desert grasslands in the USA. We removed E. lehmanniana using glyphosate at three locations in south‐eastern Arizona in 2003 and 2004 to evaluate the community response. We also sampled the seedbank five times during the course of the experiment to characterise viable seeds at the sites. Two of the sites with histories of livestock grazing responded similarly to the continued removal of E. lehmanniana, with significant increases in native cover and species richness, mainly attributable to herbaceous annual species. Over the course of the study, progressively fewer E. lehmanniana seeds and higher numbers of native annual herb seeds were germinated from seedbank samples of treated plots. At the third site, characterised by a history of intense agricultural use and drier conditions than the other sites, there was a large decrease in E. lehmanniana cover in all plots, followed by an increase in aggressive non‐native species as well as native grasses. The seedbank at this site suggested potential for restoration, with native perennial grass species present in increasing quantities. The results of this study have implications for site restoration, should a means of permanently removing E. lehmanniana be found.
Modelling within‐field spatial variability of crop biomass – weed density relationships using geographically weighted regression
Authors: BLANCO‐MORENO J M , CHAMORRO L , IZQUIERDO J , MASALLES R M , SANS F X 
Published: November 2008

SummaryThe objective of this study is to offer a new framework for exploring and modelling the spatial variation in crop biomass – weed density relationships, adapting geographically weighted regression (GWR) to include a non‐linear regression model. The relationship between crop biomass and weed density is usually modelled by non‐linear regression models, in which the spatial heterogeneity of the relationship is ignored, although the effect of weeds on crop can differ in relation to topographic and edaphic variability. GWR attempts to capture spatial variability by calibrating a regression model to each location in space. We show the application of the method in different cereal cropping systems, with one or two weed species. The results indicate that GWR can significantly improve model fitting over non‐linear least squares (NLS) in some situations. Furthermore, the parameter estimates can be mapped to illustrate local spatial variations in the regression relationship under study and eventually to relate the spatial variability of the model to the environmental heterogeneity. We discuss the value of the GWR for analysing the observed spatial variability and for improving model development and our understanding of spatial processes.
Liquid Storage of Goat Semen in Chemically Defined Extenders
Authors: Xu C‐L , Zhou J‐B , Zhao B‐T , Lan G‐C , Luo M‐J , Chang Z‐L , Sui H‐S , Tan J‐H 
Published: November 2008

ContentsThe suitability of certain commercial and self‐made chemically defined extenders for liquid storage of goat semen was tested and the effects of storage temperatures, dilution rates and sperm washing and pH of extenders on the goat sperm during liquid storage were observed. Semen was collected from nine goat bucks of the Lubei White and Boer breeds using an artificial vagina. Each ejaculate after initial evaluation was diluted with a specific extender, cooled and stored at a desired temperature. Stored semen was evaluated for sperm motility and other parameters every 24 or 48 h of storage. The ranking order of the existing milk‐ and yolk‐free extenders in sustaining goat sperm motility was Androhep > Zorlesco > Beltsville thawing solution > the Tris–glucose medium. The new extender (mZA) which was formulated based on Zorlesco and Androhep was more suitable for goat sperm than Androhep. The mZAP extender with Bovine Serum Albumin (BSA) replaced with polyvinyl alcohol (PVA) worked as efficiently as the mZA in maintaining sperm motility, membrane integrity, acrosome intactness and capacitation status. Goat sperm motility was best maintained at 5°C during liquid preservation, but decreased significantly as the temperature increased. When semen was sixfold diluted, sperm motility was maintained longer (p < 0.05) after centrifugation, but sperm motility did not differ between the centrifuged and non‐centrifuged groups when semen was 11‐fold diluted. When the extender pH was adjusted from 6.6 to 6.04, the efficiency increased significantly in both Androhep and mZAP. A forward sperm motility of 34% was maintained for 9 days when buck semen was 11‐fold diluted and stored at 5°C in mZAP, with pH adjusted to 6.04. It is concluded that for liquid storage of buck semen, the mZA extender was more suitable than other extenders; BSA can be replaced with PVA in mZA; centrifugation to remove seminal plasma can be omitted by adequate dilution; and the storage temperature and pH of extenders affected sperm motility significantly.
Serum growth factor analysis in dry eye syndrome
Authors: Bradley Jay C , Bradley Rachael H , McCartney David L , Mannis Mark J 
Published: November 2008

AbstractBackground:  To perform a comprehensive serum growth factor analysis in dry eye syndrome patients and to compare this with matched controls.Methods:  Six female dry eye syndrome patients and six age‐ and gender‐matched controls were recruited. Whole blood was collected, allowed to clot and then centrifuged. Serum was extracted by using sterile technique. Enzyme‐linked immunosorbent assays were performed to quantify serum growth factor levels.Results:  Levels of transforming growth factor‐beta 1 and 2 (TGF‐β1 and β2), nerve growth factor (NGF), insulin‐like growth factor‐1 (IGF‐1), epidermal growth factor (EGF), acidic and basic fibroblast growth factor (FGF), keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), platelet‐derived growth factor‐AA, AB and BB (PDGF‐AA, AB and BB), brain‐derived neurotrophic factor (BDNF), neurotrophin‐3 (NT‐3) and glial cell line‐derived neurotrophic factor (GDNF) were quantified, and statistical analysis was performed by using the Mann–Whitney U‐test with the Bonferroni correction.Conclusions:  No significant difference was found between serum growth factor levels in dry eye syndrome patients versus controls. Our study provides comprehensive analysis of serum growth factor levels in autologous serum eye drops produced from ocular surface disease patients. A knowledge of growth factor levels in serum may be important because of the increasing use of autologous serum eye drops in refractory ocular surface diseases and for an understanding of how topical serum may provide benefit.
Rapid visual recovery after penetrating keratoplasty for keratoconus
Authors: Sutton Gerard , Hodge Chris , McGhee Charles NJ 
Published: November 2008

AbstractPurpose:  To ascertain the level and speed of visual recovery after penetrating keratoplasty for keratoconus.Method:  A retrospective review was performed of 100 consecutive cases of penetrating keratoplasty for keratoconus, performed between 1999 and 2005. Review assessed visual function and the speed at which patients achieved a functional best corrected visual acuity (BCVA) of ≥6/12 either with glasses or phoropter. Analysis of visual, refractive and keratometric results were made on 76 eyes that had reached 6 months after suture removal. Intraoperative and postoperative complications including graft rejections were recorded.Results:  Post keratoplasty, 43.4%, 78.9% and 96.1% of patients achieved a BCVA of 6/12 or better by 1, 3 and 6 months, respectively. The mean time to achieve a BCVA of 6/12 was 9.6 weeks. Only 5.3% of patients required a rigid gas permeable contact lens. Overall 42.4% of patients had unaided visual acuity of 6/12 or better at 12 months. The mean refractive cylinder and standard deviation was 2.78 ± 1.6 D, and the mean spherical equivalent was −1.12 ± 2.9 D. There were no significant intraoperative complications, and although 3.9% of eyes had at least one graft rejection episode there were no graft failures.Conclusion:  Penetrating keratoplasty is an effective method for treating advanced keratoconus. By 3 months almost all patients are able to achieve a BCVA of 6/12 or better with progressive improvement over time. This technique allows almost half of patients to achieve an unaided vision of 6/12 or better with sutures in situ.
Accident analysis: factors contributing to a ureteric injury during deep endometriosis surgery
Authors: Schonman R , De Cicco C , Corona R , Soriano D , Koninckx PR 
Published: November 2008

Objective  To analyse factors associated with a ureteric injury.Design  Retrospective accident analysis.Setting  Deep endometriosis surgery in a tertiary referral centre.Sample  Video recording of a surgical accident was analysed by six gynaecologists.Methods  A 26‐year‐old woman underwent laparoscopy for deep endometriosis that involves the rectosigmoid and left ureter. Post operatively left ureter transection was identified and corrected by laparoscopy. Interventions were recorded and reviewed independently.Main outcome measures  Changes in surgical behaviour that could be measured were identified using the video recording.Results  During the intervention, the periods of uncontrolled bleeding (P < 0.0001) and the duration of laser activation (P = 0.013) increased progressively. Simultaneous laser activation and bipolar coagulation only occurred at the end of surgery (seven episodes). Fatigue could not be measured.Conclusion  Unconscious acceleration of surgery, possibly as a consequence of fatigue, is suggested as a contributing factor for an error of judgement.
Somali women and their pregnancy outcomes postmigration: data from six receiving countries
Authors: Small R , Gagnon A , Gissler M , Zeitlin J , Bennis M , Glazier RH , Haelterman E , Martens G , McDermott S , Urquia M , Vangen S 
Published: November 2008

Objective  This study aimed to investigate pregnancy outcomes in Somali‐born women compared with those women born in each of the six receiving countries: Australia, Belgium, Canada, Finland, Norway and Sweden.Design  Meta‐analyses of routinely collected data on confinements and births.Setting  National or regional perinatal datasets spanning 3–6 years between 1997 and 2004 from six countries.Sample  A total of 10 431 Somali‐born women and 2 168 891 receiving country‐born women.Methods  Meta‐analyses to compare outcomes for Somali‐born and receiving country‐born women across the six countries.Main outcome measures  Events of labour (induction, epidural use and proportion of women using no analgesia), mode of birth (spontaneous vaginal birth, operative vaginal birth and caesarean section) and infant outcomes (preterm birth, birthweight, Apgar at 5 minutes, stillbirths and neonatal deaths).Results  Compared with receiving country‐born women, Somali‐born women were less likely to give birth preterm (pooled OR 0.72, 95% CI 0.64–0.81) or to have infants of low birthweight (pooled OR 0.89, 95% CI 0.82–0.98), but there was an excess of caesarean sections, particularly in first births (pooled OR 1.41, 95% CI 1.25–1.59) and an excess of stillbirths (pooled OR 1.86, 95% CI 1.38–2.51).Conclusions  This analysis has identified a number of disparities in outcomes between Somali‐born women and their receiving country counterparts. The disparities are not readily explained and they raise concerns about the provision of maternity care for Somali women postmigration. Review of maternity care practices followed by implementation and careful evaluation of strategies to improve both care and outcomes for Somali women is needed.
FACTOR SHARES IN AGRICULTURE: THE CANADA‐U.S. EXPERIENCE
Authors: LEROHL M. L. , MacEACHERN G. A. 
Published: November 2008

The class shares of income in the Canadian economy and public policy developments are closely related. A comparison of the levels and trends in functional income shares with those in the United States economy generates a number of testable hypotheses. In this paper, the functional shares in all Canadian agriculture and agricultural regions are also observed and compared to US. agriculture and adjacent type of fanning regions.The analysis indicates a marked similarity in the total economy income shares despite dissimilar factor supply functions. In both countries there has been a slight upward trend in the labor share over time. The rate and pattern of growth has also been similar in the two countries; however, a serious divergence has developed in recent years. In contrast to the total economies, declining farm labor income shares characterize both agricultures. Real estate shares also have followed a similar pattern in the two countries, with the past two decades witnessing a reversal in the historical decline. Nevertheless, there are a number of differences between factor shares in Canadian and United States agriculture. In part, these can be explained by comparing adjacent regions. It is clear, however, that the different impact of technological change and economic growth has bad a great impact on regional shares. The operation of capital and labor markets within Canadian agriculture also contribute to the differences in agricultural factor shares between the two countries.
DETERMINANTS OF CHANGE IN THE NORTH AMERICAN FEEDER‐CATTLE ECONOMY
Authors: BOSWELL A. M. , MacEACHERN G. A. 
Published: November 2008

Changing flow patterns characterize the North American cattle industry, which are having a significant impact on all aspects of Canadian agriculture. A brief review of important changes taking place in the feeder cattle industry is given together with an analysis of forces influencing the changing interregional economic relationships.The results suggest an increasing rate of adjustment may be needed in the future as the economic variables and technological advances responsible for much of the change in the past continue to influence the Canadian cattle industry. The impact of change will not occur evenly across all areas and segments of the industry with the interregional trends that have developed particularly the expansion in flows from Western Canada to the Western United States showing no sign of slowing down. Eastern Canada may be under increasing pressure to expand either its imports of feeder cattle and dressed beef or develop its own feeder supply.
PRODUCTION FUNCTION ANALYSIS AS A GUIDE TO POLICY IN LOW‐INCOME FARM AREAS
Authors: SCHMITZ A. 
Published: November 2008

This paper discusses many of the problems encountered in estimating production functions in a low‐income farm area in Saskatchewan. It also ermines the difficulties of interpreting the estimated structural coefficients and their usefulness in policy formulation.The econometric difficulties discussed in production function estimation are those of function selection and choice and rearmament of variables. Many of the comments are also relevant to other forms of quantitative research.It is combed that: a great deal of arbitrariness is involved in selecting the appropriate production function model, statistical results often conflict with economic theory, it is impossible to interpret the results in a meaningful manner, and production function research is unable to. provide fruitful information for the type of policy decisions deemed desirable to change the economic structure of low‐income farm areas.
MARKETING BOARDS AND QUOTA POLICIES FOR CANADIAN FARM PRODUCTS: AN APPRAISAL OF PERFORMANCE*
Authors: WALKER H. V. 
Published: November 2008

Since the great economic Depression, Canadian farm operators have always emphasized the need to strengthen their bargaining position in the market place. Basically, farm operators believe that the individual farmer is in no position to bargain effectively in a product market with a few large firms.Legislators have responded to the wishes of farm operators by enacting legislation which provides for the formation of compulsory marketing boards controlled by producers. An ever‐increasing number of these boards are now in operation. The granting of exclusive powers to sell particular farm products, however, is one which involves the public interest and the public is, therefore, vitally interested.This paper focuses attention on the exercise of the powers vested in these marketing boards through their use of quotas, and their limitations to entry of new producers into particular sectors of the agricultural industry. The paper indicates that there are some positive features to the quota policies pursued by marketing boards. Some economic security has been afforded farm operators with short‐term stability engendered in particular sectors of agriculture. There are certain negative consequences of these quota policies, which affect the location of production and also impair the competitive strength of particular sectors of agriculture to which they are applied. They have also interfered with the most rational utilization of resources in associated industries. These aspects of the quota policies are, therefore, inconsistent with the public interest. The study outlines principles that should form the basis of a revitalized marketing policy that may be more consistent with the public interest.
FARM FINANCIAL MANAGEMENT: EMERGING PROBLEMS*
Authors: KRAUSE KENNETH R. 
Published: November 2008

Changes in the structure of Agriculture and more particularly in food and natural fiber production during the last two decades have served to focus attention on the neglected area of farm financial management. Technical farm production decisions are becoming less difficult relative to financial decisions. Financial management is not only becoming more important but is vitally connected with problems of what is going to happen to family firms; what form of business organization should they use to acquire capital, how should they obtain capital, and how should management be obtained and organized. Financial institutions are also facing some serious questions for which answers are scarce, not only because of lack of available information, but also because of conceptual voids. This paper discusses these problems particularly as they relate to relevant areas for research inquiry.SummaryIt is unlikely that the changes giving rise to the need for more attention to the agricultural finance areas will slow down in the foreseeable future. Financial parameters will be the major determinants of the entrepreneurial independence of family size and large food and natural fiber producers. The financial problems already confronting farming are numerous and complex, and the task ahead for the agricultural economists is great since time cannot be neutral in its effect if progress is to be achieved.
MEASURING MANAGEMENT PERFORMANCE OF DAIRY FARMERS
Authors: JUSTUS FRED E. , HOBBS DARYL J. , CAMPBELL REX R. 
Published: November 2008

Increased emphasis has centered on methods to measure and predict managerial performance of farmers. In doing this, one of the foremost problems is the development of a reliable and valid criterion variable, because of a number of characteristics of farming and the farm‐family complex.This article discusses problems in developing a criterion of management performance and examines the use of rating techniques for this purpose. Two rating techniques are used to measure management performance on Missouri dairy farms. The results, while suggesting major differences both in the criterion of managerial performance used by different people and in the ratings, identify sources of the differences and opportunities to improve the measuring of management performance.
AN ECONOMIC EVALUATION OF NON‐RESIDENT HUNTING AND GUIDING IN THE EAST KOOTENAY1
Authors: PEARSE PETER H. 
Published: November 2008

Guiding is an industry closely linked to ranching in Western Canada. In the more remote areas where guiding is a significant activity, agriculture is often depressed. Such complementary non‐farm sources of income are attracting increasing attention as a means of mitigating the “farm problem” in these situations.This study attempts an evaluation of the economic contribution of non‐resident hunting and the associated guiding industry in a region of British Columbia where guiding is an important adjunct to low‐income ranching. The net economic gain from non‐resident hunting is calculated, as are the private profits of guiding. These appear surprisingly low, though there is wide variation in the profitability of guiding. Public administrative policies are probably responsible in part for the failure of this industry to rationalize itself and for underutilization of game resources.
NEGATIVE TAXATION AND POVERTY
Authors: BENDER LLOYD D. , GREEN BERNAL L. 
Published: November 2008

The persistence and scope of poverty and its deleterious effects on society are far greater in the present affluent economy than leaders have anticipated. The evolving control structures have not kept the world's poverty at tolerable levels, and leaders in all countries are seeking more effective means to meet this grave challenge of our age. A negative income tax is one of these mechanisms being studied. In this paper we consider the merits of this plan as implemented in a developing region — the rural areas of the Ozarks — and compare them with the merits of the present public assistance program in the United States. The relevance of the study extends to all affluent societies.SUMMARYApplying the negative income tax to a cross section of households in the rural portion of the Ozarks Region raises questions concerning its overall effectiveness if instituted without modification. The primary issues relate to its distributive effects. Although coverage under the Friedman Negative Tax Plan is much broader than that under current welfare plans, the gap between a target income and disposable income under, the plan is not greatly decreased except at prohibitively high negative tax rates. Many former welfare recipients would receive less total income under the plan. The bulk of the negative tax payments would be received by younger multiple‐member families, and their work incentives might be reduced. Furthermore, costs of a negative tax plan would likely be high.