Economics of Management Zone Delineation in Cotton Precision Agriculture

This paper develops a management zone delineation procedure based on a spatial clustering approach and evaluates its economic impact for the case of Texas cotton production. The results show that there is potential economic value in using a spatial approach to management zone delineation, but its value critically depends on the cost of collecting soil test information needed to delineate those zones.Management Zones, Exploratory Spatial Data Analysis, Site-Specific Nitrogen Management, Cotton Precision Agriculture, Crop Production/Industries, Q12,

Economics of Management Zone Delineation in Cotton Precision Agriculture

This paper develops a management zone delineation procedure based on a spatial statistics approach and evaluates its economic impact for the case of Texas cotton production. With the use of an optimization model that utilizes a yield response function estimated through spatial econometric methods, we found that applying variable N rates based on the management zones delineated would result in higher cotton yields and higher net returns, above Nitrogen cost, relative to uniformly applying a single N rate for the whole field. In addition, a variable rate N application using the delineated management zones produced higher net returns, above Nitrogen cost, relative to a variable N rate system where the zones are based solely on landscape position. This is indicative of the potential economic value of using a spatial statistics approach to management zone delineation.Management Zones, Exploratory Spatial Data Analysis, Site-Specific Nitrogen Management, Cotton Precision Agriculture., Crop Production/Industries, Q1, Q16,

Guidelines for Recommending Precision Agriculture in Southern Crops

Technology has tremendous implications for Extension agents working with producers, agribusinesses, and youth. Four southern crops, including cotton, corn, grain sorghum, and peanuts, were evaluated under current agricultural management practices and precision farming technology. Yield, profit, and fertilizer application levels are compared across the two management practices. Field characteristics for the most profitable locations are outlined as a reference for producers in determining whether they would likely be good candidates for this technology. Results are commodity specific and suggest maximum bounds on investment levels that would be profitable to producers

Un análisis económico de la aproximación estadística para el establecimiento de zonas de manejo en agricultura de precisión: caso de algodón en Texas

Este artículo desarrolla un proceso para el establecimiento de zonas de manejo basado en una aproximación estadística espacial y evalúa su impacto económico para el caso de producción de algodón en Texas. Con el uso de un modelo de optimización que utiliza funciones de producción estimadas tomando en cuenta la autocorrelación espacial mediante métodos de econometría espacial, se encontró que al aplicar nitrógeno a una tasa variable, basada en las zonas de manejo delineadas, se obtienen rendimientos de algodón más altos comparados con los rendimientos obtenidos al aplicar una tasa uniforme de nitrógeno sobre toda la unidad productiva. Así mismo, se encontró que las aplicaciones de N a una tasa variable generan ingresos netos superiores comparados con los ingresos netos generados por la aplicación uniforme de N a la tasa agronómica sugerida, y retornos inferiores comparados con la aplicación uniforme derivada del óptimo económico. Adicionalmente, se encontró que niveles promedios de nitrógeno más bajos son requeridos con las aplicaciones de nitrógeno a una tasa variable para alcanzar rendimientos más altos comparados con la aplicación uniforme de nitrógeno.Zonas de manejo, análisis espacial exploratorio de datos, manejo espacial específico de nitrógeno, agricultura de precisión con aplicaciones en algodón.

Zebrafish Hagoromo mutants upregulate fgf8 post-embryonically and develop neuroblastoma

We screened an existing collection of zebrafish insertional mutants for cancer susceptibility by histologic examination of heterozygotes at 2 years of age. As most mutants had no altered cancer predisposition, this provided the first comprehensive description of spontaneous tumor spectrum and frequency in adult zebrafish. Moreover, the screen identified four lines, each carrying a different dominant mutant allele of Hagoromo previously linked to adult pigmentation defects, which develop tumors with high penetrance and that histologically resemble neuroblastoma. These tumors are clearly neural in origin, although they do not express catecholaminergic neuronal markers characteristic of human neuroblastoma. The zebrafish tumors result from inappropriate maintenance of a cell population within the cranial ganglia that are likely neural precursors. These neoplasias typically remain small but they can become highly aggressive, initially traveling along cranial nerves, and ultimately filling the head. The developmental origin of these tumors is highly reminiscent of human neuroblastoma. The four mutant Hagoromo alleles all contain viral insertions in the fbxw4 gene, which encodes an F-box WD40 domain–containing protein. However, although one allele clearly reduced the levels of fbxw4 mRNA, the other three insertions had no detectable effect on fbw4 expression. Instead, we showed that all four mutations result in the postembryonic up-regulation of the neighboring gene, fibroblast growth factor 8 (fgf8). Moreover, fgf8 is highly expressed in the tumorigenic lesions. Although fgf8 overexpression is known to be associated with breast and prostate cancer in mammals, this study provides the first evidence that fgf8 misregulation can lead to neural tumors. (Mol Cancer Res 2009;7(6):841–50)National Cancer Institute (U.S.) (Grant CA106416

Effects of Nitrogen and Planting Seed Size on Cotton Growth, Development, and Yield

A standardized experiment was conducted during 2009 and 2010 at 20 location-years across U.S. cotton (Gossypium hirsutum L.)-producing states to compare the N use requirement of contemporary cotton cultivars based on their planting seed size. Treatments consisted of three cotton varieties with planting seed of different numbers of seed per kg and N rates of 0, 45, 90, and 134 kg ha⁻¹. Soil at each trial location was sampled and tested for nitrate presence. High levels of soil nitrate (>91 N-NO₃⁻kg ha⁻¹) were found in Arizona and western Texas, and soil nitrate in the range of 45 to 73 kg N-NO₃⁻ ha⁻¹ was found at locations in the central United States. Cotton lint yield responded to applied N at 11 of 20 locations. Considering only sites that responded to applied N, highest lint yields were achieved with 112 to 224 kg ha⁻¹of applied plus pre-plant residual soil NO₃—translating to an optimal N requirement of 23 kg ha⁻¹ per 218 kg bale of lint produced. Among the varieties tested those with medium-sized seed produced higher yields in response to N than did larger and smaller seeded varieties. Varieties with larger seed had longer and stronger fibers, higher fiber length uniformity than small seeded varieties and decreased micronaire. Seed protein and oil increased and decreased slightly in response to increasing amounts of soil nitrate plus applied N, respectively

HIV policy: the path forward--a joint position paper of the HIV Medicine Association of the Infectious Diseases Society of America and the American College of Physicians.

Executive Summary The American College of Physicians (ACP) and the Infectious Diseases Society of America (IDSA) have jointly published 3 policy statements on AIDS, the first in 1986 [1], the second in 1988 [2], and the third in 1994 [3]. In 2001, the IDSA created the HIV Medicine Association (HIVMA), and this updated policy paper is a collaboration between the ACP and the HIVMA of the IDSA. Since the last statement, many new developments call for the need to reexamine and update our policies relating to HIV infection. First, there have been major advances in treatment for HIV infection that have transformed HIV/AIDS from a terminal illness to a chronic disease for many of those who have access to potent therapies and expert medical care [4]. Second, there has been a profound expansion and intensification of the global HIV pandemic, particularly in sub-Saharan Africa, coupled with significant US leadership and resources aimed at providing prevention and care services to affected populations in developing countries. Third, the concerns that were prevalent in the mid-1990s regarding the possibility of HIV transmission in health care settings have ultimately proven to be unfounded as the result of the adoption of universal precautions in those settings. In this article, we emphasize the public health and clinical imperatives for earlier identification of persons with HIV infection; the urgent need to expand access to state-of-the-art HIV care and treatment for infected individuals; the need for access to comprehensive prevention and education for those living with and those at risk for HIV infection; and the need for stronger national leadership to respond to the HIV epidemic in the United States and in the developing world. In December 2008, the ACP and HIVMA released a guidance statement on screening for HIV infection in health care settings that recommended that clinicians adopt routine screening for HIV infection and encourage patients to be tested. Also included in the guidance statement is a recommendation that clinicians determine the need for additional screening on an individual basis

Many Ribosomal Protein Genes Are Cancer Genes in Zebrafish

We have generated several hundred lines of zebrafish (Danio rerio), each heterozygous for a recessive embryonic lethal mutation. Since many tumor suppressor genes are recessive lethals, we screened our colony for lines that display early mortality and/or gross evidence of tumors. We identified 12 lines with elevated cancer incidence. Fish from these lines develop malignant peripheral nerve sheath tumors, and in some cases also other tumor types, with moderate to very high frequencies. Surprisingly, 11 of the 12 lines were each heterozygous for a mutation in a different ribosomal protein (RP) gene, while one line was heterozygous for a mutation in a zebrafish paralog of the human and mouse tumor suppressor gene, neurofibromatosis type 2. Our findings suggest that many RP genes may act as haploinsufficient tumor suppressors in fish. Many RP genes might also be cancer genes in humans, where their role in tumorigenesis could easily have escaped detection up to now

A Spontaneous Mutation in Contactin 1 in the Mouse

Mutations in the gene encoding the immunoglobulin-superfamily member cell adhesion molecule contactin1 (CNTN1) cause lethal congenital myopathy in human patients and neurodevelopmental phenotypes in knockout mice. Whether the mutant mice provide an accurate model of the human disease is unclear; resolving this will require additional functional tests of the neuromuscular system and examination of Cntn1 mutations on different genetic backgrounds that may influence the phenotype. Toward these ends, we have analyzed a new, spontaneous mutation in the mouse Cntn1 gene that arose in a BALB/c genetic background. The overt phenotype is very similar to the knockout of Cntn1, with affected animals having reduced body weight, a failure to thrive, locomotor abnormalities, and a lifespan of 2–3 weeks. Mice homozygous for the new allele have CNTN1 protein undetectable by western blotting, suggesting that it is a null or very severe hypomorph. In an analysis of neuromuscular function, neuromuscular junctions had normal morphology, consistent with previous studies in knockout mice, and the muscles were able to generate appropriate force when normalized for their reduced size in late stage animals. Therefore, the Cntn1 mutant mice do not show evidence for a myopathy, but instead the phenotype is likely to be caused by dysfunction in the nervous system. Given the similarity of CNTN1 to other Ig-superfamily proteins such as DSCAMs, we also characterized the expression and localization of Cntn1 in the retinas of mutant mice for developmental defects. Despite widespread expression, no anomalies in retinal anatomy were detected histologically or using a battery of cell-type specific antibodies. We therefore conclude that the phenotype of the Cntn1 mice arises from dysfunction in the brain, spinal cord or peripheral nervous system, and is similar in either a BALB/c or B6;129;Black Swiss background, raising a possible discordance between the mouse and human phenotypes resulting from Cntn1 mutations