3,027 research outputs found

    The story of a small trout fishery

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    This article relates the experience of creating and developing a fishery in southern England. The fishery was made from a small stream which dries up from time to time, and marks the boundary between a Sussex farm and a large coniferous forest. The preparation of the site and creation of the impoundment are described, and early experiences outlined. The fishery was expanded in later years, as a result of its popularity, and records of its use by anglers are illustrated. The performance of the fishery is measured in terms of "good fish" (more than 675 g) taken, and their number has increased from 81 in 1984 to 226 in 1991. The aquatic plants, invertebrates, and birds of the fishery are discussed, as are the natural predators of the fish

    Object recognition using shape-from-shading

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    This paper investigates whether surface topography information extracted from intensity images using a recently reported shape-from-shading (SFS) algorithm can be used for the purposes of 3D object recognition. We consider how curvature and shape-index information delivered by this algorithm can be used to recognize objects based on their surface topography. We explore two contrasting object recognition strategies. The first of these is based on a low-level attribute summary and uses histograms of curvature and orientation measurements. The second approach is based on the structural arrangement of constant shape-index maximal patches and their associated region attributes. We show that region curvedness and a string ordering of the regions according to size provides recognition accuracy of about 96 percent. By polling various recognition schemes. including a graph matching method. we show that a recognition rate of 98-99 percent is achievable

    New constraints on data-closeness and needle map consistency for shape-from-shading

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    This paper makes two contributions to the problem of needle-map recovery using shape-from-shading. First, we provide a geometric update procedure which allows the image irradiance equation to be satisfied as a hard constraint. This not only improves the data closeness of the recovered needle-map, but also removes the necessity for extensive parameter tuning. Second, we exploit the improved ease of control of the new shape-from-shading process to investigate various types of needle-map consistency constraint. The first set of constraints are based on needle-map smoothness. The second avenue of investigation is to use curvature information to impose topographic constraints. Third, we explore ways in which the needle-map is recovered so as to be consistent with the image gradient field. In each case we explore a variety of robust error measures and consistency weighting schemes that can be used to impose the desired constraints on the recovered needle-map. We provide an experimental assessment of the new shape-from-shading framework on both real world images and synthetic images with known ground truth surface normals. The main conclusion drawn from our analysis is that the data-closeness constraint improves the efficiency of shape-from-shading and that both the topographic and gradient consistency constraints improve the fidelity of the recovered needle-map

    WHEAT ACREAGE SUPPLY RESPONSE IN THE UNITED STATES

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    The dynamic structure of wheat acreage supply response is considerably more complex than previous studies have recognized. The distributed lag response is saw-toothed in its pattern, which is believed to eminate from the influence of summer fallow in crop rotations in the Great Plains. The acreage response elasticity estimate for the Great Plains at mean price was 1.3, and for the aggregate U.S. it was 1.5. For the Unites States, the proportion of long-run response experienced over the first five years from an increment to price was .24, .44, .70, .95, and. 99.Crop Production/Industries,

    Insect (Arthropoda: Insecta) Composition in the Diet of Ornate Box Turtles (Terrapene ornata ornata) in Two Western Illinois Sand Prairies, with a New State Record for Cyclocephala (Coleoptera: Scarabaeidae)

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    A study of fecal samples collected over a two-year period from juvenile ornate box turtles (Terrapene ornata ornata Agassiz) revealed diets consisting of six orders of insects representing 19 families. Turtles were reared in captivity from eggs harvested from local, wild populations, and released at two remnant prairies. Identifiable insect fragments were found in 94% of samples in 2013 (n=33) and 96% in 2014 (n=25). Frequency of occurrence of insects in turtle feces is similar to results reported in previous studies of midwestern Terrapene species. A comparison of insect composition presented no significant difference between release sites. There is no significant difference in consumed insect species between turtles released into or outside of a fenced enclosure at the same site. Specimens of Cyclocephala longula LeConte collected during this study represent a new state record for Illinois

    Interventions for treating oral mucositis for patients with cancer receiving treatment

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    Background Treatment of cancer is increasingly effective but is associated with short and long term side effects. Oral and gastrointestinal side effects, including oral candidiasis, remain a major source of illness despite the use of a variety of agents to treat them. Objectives To assess the effectiveness of interventions for the treatment of oral candidiasis for patients with cancer receiving chemotherapy or radiotherapy or both. Search strategy Computerised searches of Cochrane Oral Health Group and PaPaS Trials Registers (to 1 June 2010), CENTRAL via the Cochrane Library (Issue 2, 2010, 1 June 2010), MEDLINE via OVID (1 June 2010), EMBASE via OVID (1 June 2010), CINAHL via EBSCO (1 June 2010), CANCERLIT via PubMed (1 June 2010), OpenSIGLE (1 June 2010) and LILACS via Virtual Health Library (1 June 2010) were undertaken. Reference lists fromrelevant articles were searched and the authors of eligible trials were contacted to identify trials and obtain additional information. Selection criteria All randomised controlled trials comparing agents prescribed to treat oral candidiasis in people receiving chemotherapy or radiotherapy for cancer. The outcomes were eradication of oral candidiasis, dysphagia, systemic infection, amount of analgesia, length of hospitalisation, cost and patient quality of life. Data collection and analysis Data were independently extracted, in duplicate, by two review authors. Trial authors were contacted for details of randomisation and withdrawals and a quality assessment was carried out. Risk ratios (RR) were calculated using fixed-effect models. Main results Ten trials involving 940 patients, satisfied the inclusion criteria and are included in this review. Drugs absorbed from the gastrointestinal (GI) tract were beneficial in eradication of oral candidiasis compared with drugs not absorbed from the GI tract (three trials: RR = 1.29, 95% confidence interval (CI) 1.09 to 1.52), however there was significant heterogeneity. A drug absorbed from the GI tract, ketoconazole, wasmore beneficial than placebo in eradicating oral candidiasis (one trial: RR = 3.61, 95% CI 1.47 to 8.88). Clotrimazole, at a higher dose of 50 mg was more effective than a lower 10 mg dose in eradicating oral candidiasis, when assessed mycologically (one trial: RR = 2.00, 95% CI 1.11 to 3.60). Only one of the ten trials was assessed as at low risk of bias. Authors' conclusions There is insufficient evidence to claimor refute a benefit for any antifungal agent in treating candidiasis. Further well designed, placebo-controlled trials assessing the effectiveness of old and new interventions for treating oral candidiasis are needed. Clinicians need to make a decision on whether to prevent or treat oral candidiasis in patients receiving treatment for cancer. This review is published as a Cochrane Review in the Cochrane Database of Systematic Reviews 2010, Issue 7. Cochrane Reviews are regularly updated as new evidence emerges and in response to comments and criticisms, and the Cochrane Database of Systematic Reviews should be consulted for the most recent version of the Review.</p

    How are small firms financed? Evidence from small business investment companies

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    This article examines the investment decisions of small business investment companies (SBICs). The results indicate that potential costs of contracting among SBICs, small firms, and others may have significant effects on how small firms are funded. For instance, projects generating tangible assets and firms operating in industries with few growth opportunities are more likely to be financed with debt than nondebt.Small business ; Venture capital

    Performance and access to government guarantees: the case of small business investment companies

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    This article analyzes the performance of small business investment companies (SBICs) that are chartered and regulated by the Small Business Administration (SBA). Our principal finding is that poor performance over the 1986-91 period is associated with high usage of funds from the SBA.Small business

    A Trojan horse or the golden fleece? small business investment companies and government guarantees

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    Profitability is a central concern when governments provide guarantees to increase the flow of funds to disadvantaged groups. We examine the profitability of small business investment companies (SBICs) that are chartered and regulated by the U.S. Small Business Administration (SBA) to finance the activities of small firms. We document, over the 1986-91 period, dismal performance by SBICs. Because SBICs have access to government-guaranteed funds, financial distress among SBICs can expose the SBA, and hence taxpayers, to losses. Using two alternative sample selection models, we examine the relationship between SBICs’ use of SBA funds and returns on equity (ROE) and survival probabilities. The first sample selection model is based on a model of failure/survival. The second selection model is based on our observation that many SBICs do not take advantage of SBA leverage: nearly one-third of SBICs use no leverage at all, and that figure rises to three-fifths for bank-owned SBICs. The results from our sample selection models indicate that SBA leverage--the amount of funds borrowed from the SBA as a percent of private capital--reduces ROE and the probability of survival. In addition, we find that the probability of using SBA leverage decreases for bank-owned SBICs relative to other SBICs and for highly profitable and efficient SBICs, while it increases for SBICs using debt to finance the activities of small firms. Thus, our results suggest that an SBIC’s performance is negatively correlated with SBA leverage.Small business
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