bluuebunny/crossref_metadata_2025_split huggingface dataset:
Romaine lettuce latex deters feeding of banded cucumber beetle: a vehicle for deployment of biochemical defenses
Authors: Sethi Amit , McAuslane Heather J. , Alborn Hans T. , Nagata Russell T. , Nuessly Gregg S. 
Published: June 2008

AbstractLatex is widely found among plant species and is known to play a defensive role against certain herbivores. Two romaine lettuce, Lactuca sativa L. (Asteraceae) cultivars, ‘Valmaine’ (resistant) and ‘Tall Guzmaine’ (susceptible), were selected to study the potential of latex as a defense mechanism against the banded cucumber beetle, Diabrotica balteata LeConte (Coleoptera: Chrysomelidae). Latex from Valmaine strongly inhibited feeding of adult D. balteata compared to latex from Tall Guzmaine when applied to the surface of artificial diet. Beetles consumed significantly less diet from disks treated with Valmaine latex than they consumed from diet treated with Tall Guzmaine latex, in both choice and no‐choice tests. In a choice test involving diet disks treated with Valmaine latex from young leaves vs. disks treated with latex from mature leaves, the beetles consumed significantly less diet treated with latex from young leaves. No significant difference in diet consumption was found between diets treated with latex from young and mature leaves of Tall Guzmaine in choice tests. Three solvents of differing polarity (water, methanol, and methylene chloride) were tested to extract deterrent compounds from latex; Valmaine latex extracted with water:methanol (20:80) strongly inhibited beetle feeding when applied to the surface of artificial diet. In no‐choice tests, fewer beetles were observed feeding on diet treated with water:methanol (20:80) extract of Valmaine latex than on diet treated with a similar extract of Tall Guzmaine latex, resulting in significantly less consumption of the diet treated with the Valmaine latex extract. These studies suggest that moderately polar chemicals within latex may account for resistance in Valmaine to D. balteata.
Isolation and agricultural productivity
Authors: Stifel David , Minten Bart 
Published: June 2008

AbstractThis article examines the mechanisms that transmit isolation into productivity. In particular, we study the effect of isolation and transport infrastructure on welfare and agricultural productivity in the case of Madagascar. Madagascar is a good case study given the bad shape of its infrastructure and therefore the significant variation in isolation. Based on comprehensive household survey data combined with a census of communes, we discover a strong poverty–isolation relationship. Further we find the inverse relationship between agricultural productivity and isolation to be surprisingly strong. We isolate the following reasons why productivity might decline with isolation: (i) transportation‐induced transaction costs, (ii) the inverse relationship between plot size and productivity, (iii) increasing price variability and extensification onto less fertile land, and (iv) insecurity.
Measuring the impact of road rehabilitation on spatial market efficiency in maize markets in Mozambique
Authors: Cirera Xavier , Arndt Channing 
Published: June 2008

AbstractThis article analyzes the impact of road rehabilitation on the spatial market efficiency of maize markets in Mozambique. We estimate a modified version of the Parity Bounds Model (PBM) that allows us to test the impact of road rehabilitation on spatial efficiency. This article seeks to contribute to the existing literature in three ways. First, a unique data set, where road rehabilitation episodes between market pairs are identified, is developed. Second, special care is devoted to estimation of transaction costs due to the sensitivity of the PBM model to the quality of transaction costs estimates. Finally, as opposed to most existing literature that focuses on relatively distant markets, the article focuses on spatially closed markets. We find that maize markets tend to be segmented due to high transport costs. Following road rehabilitation, inefficiency and average absolute price differentials tend to decrease, and market pairs have tended to shift toward autarky regimes. Overall, while the results point broadly toward a positive impact of road rehabilitation on spatial efficiency, they are not as strong or as robust as one would like. Large increases in fuel prices likely offset the positive impacts of road rehabilitation on transaction costs, contributing to the increase in the probability of being in an autarky regime.
Applying cointegration and error correction to measure trade linkages: maize prices in the United States and Mexico
Authors: Motamed Mesbah , Foster Kenneth A. , Tyner Wallace E. 
Published: June 2008

AbstractThe impact of U.S.‐grown maize on Mexican markets is a subject of heated debate, and is complicated by limited substitution between white and yellow maize as well as regional price differences within Mexico. This article improves on previous analyses using a detailed data set of white maize prices reported weekly in 11 states across Mexico from 1998 through 2005. Using cointegration analysis and the error‐correction model, we find that prices between the United States and Mexico do not share a common long‐run relationship. Within Mexico, prices in Michoacán and Oaxaca are only weakly related with prices in neighboring states, whereas prices in Sinaloa and Jalisco exert considerable influence on prices elsewhere in Mexico. We conclude that, despite North American Free Trade Agreement (NAFTA), white maize prices in Mexico are determined by local conditions including particularly the degree of integration to other regions within Mexico.
More reasons why farmers have so little interest in futures markets
Authors: Pannell David J. , Hailu Getu , Weersink Alfons , Burt Amanda 
Published: June 2008

AbstractThe use by farmers of futures contracts and other hedging instruments has been observed to be low in many situations, and this has sometimes seemed to be considered surprising or even mysterious. We propose that it is, in fact, readily understandable and consistent with rational decision making. Standard models of the decision about optimal hedging show that it is negatively related to basis risk, to quantity risk, and to transaction costs. Farmers who have less uncertainty about prices and those with a diversified portfolio of investments have lower optimal levels of hedging. If a farmer has optimistic price expectations relative to the futures market, the incentive to hedge can be greatly reduced. And finally, farmers who have low levels of risk aversion have little to gain from hedging in terms of risk reduction, in that the certainty‐equivalent payoff at their optimal hedge may be little different than the certainty equivalent under zero hedging. These reasons are additional to the argument of Simmons (2002) who showed that, if capital markets are efficient, farmers can manage their risk exposure through adjusting their leverage, obviating the need for hedging instruments.
Technical efficiency and impact of environmental regulations in farrow‐to‐finish swine production in Taiwan
Authors: Yang Chih‐Ching , Hsiao Ching‐Kai , Yu Ming‐Miin 
Published: June 2008

AbstractThis article demonstrates how technical efficiency and the impact of environmental regulations of Taiwanese farrow‐to‐finish swine production can be estimated in the presence of undesirable outputs. The issue of measuring technical efficiencies while considering undesirable outputs has been addressed by past studies. But the proper method of including undesirable outputs has always been a subject of debate. This article develops a data envelopment analysis (DEA)‐based model that includes undesirable outputs. The technologies of desirable output production and undesirable output control are considered simultaneously. This allows one to transform undesirable output into desirable output, whereby a traditional Shephard distance function can be used to measure technical efficiencies. An approach to measuring the impacts due to environmental regulations is then derived. Empirical results show that larger farms are more technically efficient than small‐sized farms, but no clear conclusions can be reached for the measures of regulatory impact among farms with different sizes. On average, the sample farms incurred an opportunity cost due to environmental regulations equivalent to 9.8% of market value. Opportunity costs rise with efficiency.
Raising offtake from cattle grazed on natural rangelands in sub‐Saharan Africa: a transaction cost economics approach
Authors: Kyeyamwa Herbert , Speelman Stijn , Van Huylenbroeck Guido , Opuda‐Asibo John , Verbeke Wim 
Published: June 2008

AbstractFarmers in sub‐Saharan Africa are constrained by large transaction costs associated with marketing of their livestock. However, transaction costs are often not taken into account in the analysis of factors hampering the development of livestock marketing in this region. This article empirically measures the influence of transaction costs on the offtake from cattle grazed on natural rangelands in Uganda. The study is based on the monitoring of 696 cattle transactions in three districts of Uganda from August 2004 to August 2005. The estimated models suggest that proportional transaction costs represented by the state of roads, distance to markets, and time taken to reach the market are important variables constraining market participation. In order to raise offtake from the national herd, it is essential to explicitly address these costs. One potential solution is collective action in marketing of livestock in which proportional and fixed transaction costs are reduced and shared among the group members.
Modeling the length and shape of the R&D lag: an application to UK agricultural productivity
Authors: Thirtle Colin , Piesse Jenifer , Schimmelpfennig David 
Published: June 2008

AbstractThis article updates total factor productivity (TFP) growth in UK agriculture from 1953–2005 and shows that public and private research and returns to scale explain TFP. Cointegration and causality tests are used to investigate the validity of attempts to explain UK agricultural productivity with R&D and related technology variables. Then, the length and shape of the lag structures are modeled and compared with the structures that are commonly imposed on the data. The rates of return (ROR) to R&D using the data determined lags differ considerably from those obtained by imposing lag shapes. These comparisons show that the ROR to public R&D are sensitive to the lag shape as well as its length and that the omission of other technology variables, such as mechanical and chemical patents pertaining to agriculture and farm size can bias the ROR.
The costs of global tariff barriers on wool products: 1997–2005
Authors: Verikios George 
Published: June 2008

AbstractThe Doha round of multilateral trade negotiations commits World Trade Organization (WTO) members to improving market access for both agricultural and nonagricultural goods. Tariff barriers on wool products represent a small but important subset of these negotiations. To inform the debate on the round, we analyze the distortionary effects of recent (1997–2005) tariff barriers on wool products using a model that applies a comprehensive analytical approach with regard to the production, trade, and consumption of wool products. We also account for any indirect effects of wool tariff barriers on the nonwool economy by incorporating the production, trade, and consumption of nonwool products, that is, the framework is a comparative‐static global general equilibrium model with a detailed representation of the world wool market. Changes in wool tariffs over 1997–2005 lead to positive welfare effects for most regions; Italy, China, and the UK are estimated to have gained the most from the changes. The results indicate that the nature of recent wool tariffs severely distort the size of wool industries in different regions. The changes in the output of wool commodities are extreme reflecting the discriminatory nature of the tariffs.
On farmland prices and rents in Japan
Authors: Shigeto Sawako , Hubbard Lionel , Dawson Philip 
Published: June 2008

AbstractHistorically, the Japanese farmland market has been strongly regulated, although fundamental changes in policy were introduced in 1967 and 1980. This article examines the relationship between farmland prices and rents in Japan for 1955–2000 using the cointegration procedure of Johansen et al. (2000), which admits structural breaks. Results show the presence of a cointegrating relationship with a significant break in 1980. There is Granger‐causality from prices to rents, which suggests that rents are determined within an institutional setting according to farmland prices. The rent–price elasticity is unity, which supports the notion of efficiency in the farmland market.
Supply and demand estimates for feed grains in China
Authors: Zhou Zhang Y. , Tian Wei M. , Malcolm Bill 
Published: June 2008

AbstractIn the past two decades, the use of grain to feed livestock in China has increased rapidly. A number of studies have examined demand and supply of grain for animal feed in China. Forecasts have been made. Generally, these projections have turned out to be well wide of the actual supply and demand. Further, forecasts of supply and demand for feed grains for the same time periods have differed greatly. Accurate forecasts of variables affecting supply and demand benefit both producers and consumers. Past forecasts of supply and demand of feed grain for livestock production in China are reviewed and reasons for discrepancies between projections are explored. Ways to improve projections of demand for and supply of grain for livestock feed in China are identified.
Nonlinear adjustments in deviations from the law of one price for wholesale hog prices
Authors: Chen Pei‐Fen , Lee Chien‐Chiang 
Published: June 2008

AbstractThis article applies the Band‐Threshold Autoregression (Band‐TAR) model to investigate whether the law of one price (LOOP) holds in Taiwanese wholesale hog markets during the period from May 1987 through December 2003. We find evidence of a nonlinear mean reversion in deviations from the LOOP for relative hog prices. Our empirical study confirms the presence of thresholds and provides strong evidence in support of the view that the regional hog markets have been tightly integrated in Taiwan and that the wholesale hog market in Taiwan is an efficient market economy. Furthermore, the estimated half‐lives from the nonlinear generalized impulse response analysis are as short as four months.
Adoption of organic farming in Germany and Austria: an integrative dynamic investment perspective
Authors: Musshoff Oliver , Hirschauer Norbert 
Published: June 2008

AbstractFarm‐level adaptation to changing economic environments is often slower than expected. Technological innovations, for instance, are frequently adopted at a later date than the net present value of investment suggests. This can be explained by a model of “investment under uncertainty,” which consistently accounts for uncertainty, sunk costs, and the flexibility of investment timing. Its essential conclusion is that, due to temporal opportunity costs, critical incremental cash flows that trigger investments might be higher than those needed for simple cost recovery. This accounts for an ostensible reluctance to invest (economic hysteresis). In this article, we demonstrate how slow conversion to organic farming in general, and the different rates of conversion in Germany and Austria in particular, can be explained by the new investment theory.
Periodontal inflamed surface area: quantifying inflammatory burden
Authors: Nesse Willem , Abbas Frank , Van Der Ploeg Ids , Spijkervet Frederik Karst Lucien , Dijkstra Pieter Ubele , Vissink Arjan 
Published: June 2008

AbstractBackground: Currently, a large variety of classifications is used for periodontitis as a risk factor for other diseases. None of these classifications quantifies the amount of inflamed periodontal tissue, while this information is needed to assess the inflammatory burden posed by periodontitis.Aim: To develop a classification of periodontitis that quantifies the amount of inflamed periodontal tissue, which can be easily and broadly applied.Material and Methods: A literature search was conducted to look for a classification of periodontitis that quantified the amount of inflamed periodontal tissue. A classification that quantified the root surface area affected by attachment loss was found. This classification did not quantify the surface area of inflamed periodontal tissue, however. Therefore, an Excel spreadsheet was developed in which the periodontal inflamed surface area (PISA) is calculated using clinical Attachment Level (CAL), recessions and bleeding on probing (BOP).Results: The PISA reflects the surface area of bleeding pocket epithelium in square millimetres. The surface area of bleeding pocket epithelium quantifies the amount of inflamed periodontal tissue. A freely downloadable spreadsheet is available to calculate the PISA.Conclusion: PISA quantifies the inflammatory burden posed by periodontitis and can be easily and broadly applied.
Innate immune modulation of keratinocytes by antikeratin 16 antibodies
Authors: Wu Caixia , Li Chengxin , Wei Liming , Zheng Zhizhong 
Published: June 2008

AbstractBackground:  Chronic inflammation of psoriatic lesions may be due to an exaggerated innate immune response. Toll‐like receptors (TLRs) are expressed by keratinocytes in psoriasis. Antikeratin 16 autoantibodies (AK16 autoAbs) are increased in serum from patients with psoriasis. Whether the elevated AK16 autoAbs play a role in psoriasis by exaggerating innate immune response is still unknown.Objective:  To prove that AK16 autoAbs are involved in psoriasis, by exaggerating the innate immune response of keratinocytes.Methods:  Keratinocytes were incubated with mouse antikeratin 16 monoclonal antibodies (AK16 mAbs) for a given length of time. Levels of TLR2, TLR4, involucrin and nascent polypeptide‐associated complex (NACA) mRNA were measured by quantitative RT‐PCR. Levels of TLR2, TLR4, involucrin, NF‐κB and actin‐related protein 2 (ARP2) protein were measured by flow cytometry or Western blot. Effects of the mAbs on keratinocytes were studied using DNA synthesis and cell cycle analysis.Results:  TLR2 mRNA increased 1.73‐, 1.60‐ and 2.52‐fold at 6, 24 and 36 h after incubation, respectively. TLR4 mRNA increased 3.62‐ and 2.21‐fold after 12 and 36 h. Involucrin mRNA increased 2.33‐ and 2.0‐fold after 12 and 36 h. NACA mRNA increased 5.93‐, 3.35‐ and 3.54‐fold after 12, 24 and 36 h. TLR2 protein increased 1.73‐fold on the cell membrane and 2.22‐fold on membrane plus intracytoplasm. NF‐κB increased 2.64‐fold after 6 h. Involucrin protein increased 4.5‐fold, whereas Arp2 protein decreased 1.82‐fold, after 36 h. The mAbs had an inhibitory effect on cultured keratinocytes.Conclusion:  AK16 autoAbs may be involved in the chronic inflammation of psoriasis lesions by promoting TLR expression.
Antibiotic treatment of cutaneous infections with Staphylococcus aureus in patients with atopic dermatitis: current antimicrobial resistances and susceptibilities
Authors: Niebuhr Margarete , Mai Uwe , Kapp Alexander , Werfel Thomas 
Published: June 2008

SummaryBackground/aims:  Atopic dermatitis (AD) is a common chronic inflammatory skin disease. In many patients, the disease is complicated by enhanced susceptibility to skin infections, especially with Staphylococcus aureus. The aim of this study was to determine the antimicrobial susceptibility of skin‐colonizing S. aureus strains in patients with AD and consecutively to recommend the first‐line antibiotic therapy.Methods:  We studied S. aureus‐positive skin swabs (n = 102) from lesional skin of children, adolescents and adults with AD presenting to our inpatient and outpatient departments from January 2005 to June 2006.Results:  Antimicrobial susceptibility testing revealed resistance against oxacillin, amoxicillin/clavulanic acid, cephalexin and cefuroxim in 3%, against tetracycline in 17%, against gentamicin in 16%, against erythromycin and clindamycin in 21%, against trimethoprim/sulfamethoxazol in 23%, against levofloxacin in 23%, against fusidic acid in 25%, against fosfomycin in 12% and against rifampicin in 16%. All strains isolated were susceptible to vancomycin.Conclusion:  Currently, the first generation cephalosporin cephalexin appears to be the preferential first‐line antibiotic for the treatment of bacterial superinfections with S. aureus in children and adults with AD due to its restricted antimicrobial spectrum to Gram‐positive bacteria and a limited number of Gram‐negative strains. Cefuroxim and amoxicillin/clavulanate, which also showed 3% resistances in our patients, cover a broader range of bacterial micro‐organisms. However, a broader coverage is not required in case of AD, as S. aureus is the most frequent bacterial micro‐organism causing skin infections.
Physiological changes in tissues denervated by spinal cord injury tissues and possible effects on wound healing
Authors: Rappl Laurie M 
Published: June 2008

AbstractThere are many metabolic and physiological changes that happen to the tissues below the level of a spinal cord injury. These deficits are examined in relation to the series of events that has to take place for wound healing – the “wound healing cascade”. The conclusion is that every step of the wound healing process is impaired by the physiological deficits inherent post‐spinal cord injury. This may explain, in part, why pressure ulcers on these patients are so difficult to close and to maintain closed.
Use of chlorhexidine‐impregnated patch at pin site to reduce local morbidity: the ChIPPS Pilot Trial
Authors: Wu Stephanie C , Crews Ryan T , Zelen Charles , Wrobel James S , Armstrong David G 
Published: June 2008

AbstractPin tract infection is one of the most common complications associated with the use of external fixation. While some studies have identified the potential benefit of chlorhexidine gluconate‐impregnated polyurethane dressings to reduce the incidence of catheter‐related bloodstream infections, we are unaware of any published studies that evaluate the effectiveness of similar technologies in reducing the risk for external‐fixation‐related pin tract infections. Therefore, the purpose of this study was to evaluate the effectiveness of chlorhexidine gluconate‐impregnated polyurethane dressing in reducing percutaneous‐device‐related skin colonisation and local infections. In this initial retrospective cohort, data were abstracted for two groups of consecutive patients undergoing surgery involving external fixation at an interdisciplinary foot and ankle surgical unit. All patients received surgical treatment of their foot/ankle pathology along with application of a hybrid external fixator. Twenty patients (45% male, age 54·5 ± 3·69 years) received chlorhexidine gluconate‐impregnated polyurethane dressing and twenty (55% male, age 55·8 ± 3·22 years) received standard pin care. There was a significantly higher rate of pin tract infection in patients who received standard pin care compared with those who received chlorhexidine gluconate‐impregnated polyurethane dressings (25% versus 0%, P = 0·047). There was no significant difference in any of the descriptive study characteristics (age, gender, diabetes and presence of neuropathy). The results of this initial study suggest that chlorhexidine gluconate‐impregnated polyurethane dressing may be effective to reduce the incidence of pin tract infections and help decrease morbidity associated with external fixation.