Leaching of hexachlorocyclohexane isomers in a flooded field unplanted or planted to rice

Leaching ofα-, β-, γ- andδ-isomers of hexachlorocyclohexane (HCH) in a commercial formulation, sprayed to a flooded field (unplanted or planted to rice) at 1.0 kg a.i. ha ^?1 onγ-isomer basis, was studied with the help of field-installed porous moisture extraction cups. Residues of HCH-isomers in the surface field water and leachates (at 15, 30 and 60 cm) were higher in planted field than in unplanted field, probably due to less volatilization of HCH-isomers under the crop cover. HCH-isomers, with the exception ofβ-isomer, migrated to 30 cm depth;β-isomer did not move beyond 15 cm depth possibly due to lower amount of this isomer available for leaching whileα-HCH was detected even at 60 cm depth.γ-Tetrachlorocyclohexene, a predicted metabolite ofγ-HCH in anaerobic environments, was detected in the the leachate even at 60 cm depth.     

Simulation of Potato Late Blight in the Andes. II: Validation of the LATEBLIGHT Model

ABSTRACT LATEBLIGHT, a mathematical model that simulates the effect of weather, host growth and resistance, and fungicide use on asexual development and growth of Phytophthora infestans on potato foliage, was validated for the Andes of Peru. Validation was needed due to recent modifications made to the model, and because the model had not been formally tested outside of New York State. Prior to validation, procedures to estimate the starting time of the epidemic, the amount of initial inoculum, and leaf wetness duration were developed. Observed data for validation were from field trials with three potato cultivars in the Peruvian locations of Comas and Huancayo in the department of Junín, and Oxapampa in the department of Pasco in 1999 and 2000 for a total of 12 epidemics. These data had not been used previously for estimating model parameters. Observed and simulated epidemics were compared graphically using disease progress curves and numerically using the area under the disease progress curve in a confidence interval test, an equivalence test, and an envelope of acceptance test. The level of agreement between observed and simulated epidemics was high, and the model was found to be valid according to subjective and objective performance criteria. The approach of measuring fitness components of potato cultivars infected with isolates of a certain clonal lineage of P. infestans under controlled conditions and then using the experimental results as parameters of LATEBLIGHT proved to be effective. Fungicide treatments were not considered in this study.     

Feline endocrinopathies.

Feline endocrinopathies (excluding diabetes mellitus) include hyperthyroidism, hypothyroidism, acromegaly, hyposomatotropism, diabetes insipidus, hyperadrenocorticism, primary sex hormone-secreting adrenal tumors, primary hyperaldosteronism, pheochromocytoma, hypoadrenocorticism, hyperparathyroidism, and hypoparathyroidism. Each of these conditions will be discussed including their prevalence, cause, clinical signs, diagnosis, treatment options, and prognosis.     

Assessing irrigation projects performance for sustainable irrigation policy reform

This study examines the socio-economic and financial performances of irrigation projects under the Ogun-Oshun River Basin and Rural Development Authority (O-ORBRDA) in Nigeria. Primary data on the farming activities of the project farmers during the 2001/02 seasons and the projects' records for the period of 1995/96 to 2001/02 were summarised into socio-economic and financial performance indicators. In the Sepeteri Project, a revenue recovery level of 96% was estimated. The project is not financially viable as only 29% of its recurrent expenditure is covered. The farmers do not show commitment to making the project successful. An approximate 67% social capacity level was estimated. The relative irrigation cost and profit indexes do not show sufficient evidence that farmers would prefer irrigation farming to rain-fed farming. The Itoikin Project records a lower revenue recovery level of 75%. The project covers about 50% of its recurrent expenditure. In addition, the farmers do not appear to have a commitment to making the project successful, with a 33% social capacity level. A number of problems may be the causes of unprofitable irrigated cropping. If government increases the subvention, the O-ORBRDA prioritises irrigation service in disbursing the subvention to the projects, and the project manages the risks in the project sites, conscientises and incorporates the intended beneficiaries into managing the projects, the projects would be equipped to supply more irrigation services thereby making it more profitable and encouraging more participation of the intended beneficiaries. This would improve the socio-economic and financial performance of the projects.     

A genomic search for the gene conferring resistance to fusarium wilt in tomato

Fusarium wilt is an economically important disease of tomatoes, caused by the soil-born fungus Fusarium oxysporum f. sp. lycopersici. There are three host-specific races of this pathogen. The dominant tomato gene I-2 confers resistance to race 2. The I-2 fusarium resistance gene was mapped genetically to chromosome 11 of tomato, between the RFLP markers TG105 and TG36, 0.4 centiMorgan (cM) from TG105. A mean value of 43 kb for each cM was assigned in the vicinity of I-2. We have generated new RFLP markers in the region by chromosome walking from TG105 towards I-2 on lambda clones, and by subcloning a 350 kb long YAC clone (YAC 8) that contains TG105. These RFLP markers were mapped physically on YAC 8 by PFGE. The location of I-2 relative to these markers was genetically estimated using a recombinant inbred (RI) segregating population. The order of the markers according to the RI population is inconsistent with their order on the physical map. A cDNA clone, D14, that was isolated by YAC 8, turned out to be 53% similar to xanthine dehydrogenase from mammals and flies. Antibodies raised against a part of the protein encoded by D14 recognize cross reacting material of MW 80 kD, that is highly enriched in nodules of legumes, and seems to be induced by various environmental and pathogenic stress conditions.     

The Marek��s disease virus (MDV) protein encoded by the UL17 ortholog is essential for virus growth

Marek’s disease virus type 1 (MDV-1) shows a strict dependency on the direct cell-to-cell spread for its propagation in cell culture. As MDV-1 shows an impaired nuclear egress in cell culture, we wished to address the characterization of capsid/tegument genes which may intervene in the maturation of intranuclear capsids. Orthologs of UL17 are present in all herpesviruses and, in all reported case, were shown to be essential for viral growth, playing a role in capsid maturation and DNA packaging. As only HSV-1 and PrV UL17 proteins have been characterized so far, we wished to examine the role of MDV-1 pUL17 in virus replication. To analyze MDV-1 UL17 gene function, we created deletion mutants or point mutated the open reading frame (ORF) to interrupt its coding phase. We established that a functional ORF UL17 is indispensable for MDV-1 growth. We chose to characterize the virally encoded protein by tagging the 729 amino-acid long protein with a repeat of the HA peptide that was fused to its C-terminus. Protein pUL17 was identified in infected cell extracts as an 82 kDa protein which localized to the nucleus, colocalizing with VP5, the major capsid protein, and VP13/14, a major tegument protein. By using green fluorescent protein fusion and HA tagged proteins expressed under the cytomegalovirus IE gene enhancer/promoter (P_{CMV IE}), we showed that MDV-1 pUL17 nuclear distribution in infected cells is not an intrinsic property. Although our results strongly suggest that another viral protein retains (or relocate) pUL17 to the nucleus, we report that none of the tegument protein tested so far were able to mediate pUL17 relocation to the nucleus.     

Antioxidant profiling of native Andean potato tubers (Solanum tuberosum L.) reveals cultivars with high levels of beta-carotene, alpha-tocopherol, chlorogenic acid, and petanin

The antioxidant profile of 23 native Andean potato cultivars has been investigated from a human nutrition perspective. The main carotenoid and tocopherol compounds were studied using high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD) and a fluorescence detector, respectively, whereas polyphenols (including anthocyanins in colored tubers) were identified by means of both HPLC-mass spectrometry and HPLC-DAD. Antioxidant profiling revealed significant genotypic variations as well as cultivars of particular interest from a nutritional point of view. Concentrations of the health-promoting carotenoids, lutein and zeaxanthin, ranged from 1.12 to 17.69 microg g(-1) of dry weight (DW) and from 0 to 17.7 microg g(-1) of DW, with cultivars 704353 and 702472 showing the highest levels in lutein and zeaxanthin, respectively. Whereas beta-carotene is rarely reported in potato tubers, remarkable levels of this dietary provitamin A carotenoid were detected in 16 native varieties, ranging from 0.42 to 2.19 microg g(-1) of DW. The amounts of alpha-tocopherol found in Andean potato tubers, extending from 2.73 to 20.80 microg g(-1) of DW, were clearly above the quantities generally reported for commercial varieties. Chlorogenic acid and its isomers dominated the polyphenolic profile of each cultivar. Dark purple-fleshed tubers from the cultivar 704429 contained exceptionally high levels of total anthocyanins (16.33 mg g(-1) of DW). The main anthocyanin was identified as petanin (petunidin-3-p-coumaroyl-rutinoside-5-glucoside). The results suggest that Andean potato cultivars should be exploited in screening and breeding programs for the development of potato varieties with enhanced health and nutritional benefits.     

Andean potato cultivars (Solanum tuberosum L.) as a source of antioxidant and mineral micronutrients

Potato tubers were evaluated as a source of antioxidants and minerals for the human diet. A genetically diverse sample of Solanum tuberosum L. cultivars native to the Andes of South America was obtained from a collection of nearly 1000 genotypes using microsatellite markers. This size-manageable collection of 74 landraces, representing at best the genetic diversity among potato germplasm, was analyzed for iron, zinc, calcium, total phenolic, total carotenoid, and total vitamin C contents. The hydrophilic antioxidant capacity of each genotype was also measured using the oxygen radical absorbance capacity (ORAC) assay. The iron content ranged from 29.87 to 157.96 microg g-1 of dry weight (DW), the zinc content from 12.6 to 28.83 microg g-1 of DW, and the calcium content from 271.09 to 1092.93 microg g-1 of DW. Total phenolic content varied between 1.12 and 12.37 mg of gallic acid equiv g-1 of DW, total carotenoid content between 2.83 and 36.21 microg g-1 of DW, and total vitamin C content between 217.70 and 689.47 microg g-1 of DW. The range of hydrophilic ORAC values was 28.25-250.67 micromol of Trolox equiv g-1 of DW. The hydrophilic antioxidant capacity and the total phenolic content were highly and positively correlated (r = 0.91). A strong relationship between iron and calcium contents was also found (r = 0.67). Principal component analysis on the studied nutritional contents of the core collection revealed that most potato genotypes were balanced in terms of antioxidant and mineral contents, but some of them could be distinguished by their high level in distinct micronutrients. Correlations between the micronutrient contents observed in the sample and the genetic distances assessed by microsatellites were weakly significant. However, this study demonstrated the wide variability of health-promoting micronutrient levels within the native potato germplasm as well as the significant contribution that distinct potato tubers may impart to the intake in dietary antioxidants, zinc, and iron.     

Generierung variabler Sortier- und Kalkulationshilfen für den Forstbetrieb

Zusammenfassung Auch im Zeitalter des PC haben für einige forstliche Arbeitsbereiche tabellarische Entscheidungshilfen noch eine gewisse Berechtigung. Dies trifft beispielsweise auf die Vorkalkulation von Holzerntema?nahmen sowie die j?hrliche Sorten- und Hiebsplanung auf Revier- und Betriebsebene zu. Derartige Sortier- und Kalkulationshilfen sind aber heute nur noch dann sinnvoll, wenn sie einfach zu erstellen und schnell zu aktualisieren sind sowie jederzeit den betrieblichen Gegebenheiten angepa?t werden k?nnen. Die hier abgedruckten Hiebs- und Deckungsbeitragstarife haben in erster Linie Modell- und Beispielcharakter und sollen zur Aufstellung eigener Tafeln mit Hilfe einer speziellen Software anregen. Dies erfordert die Berücksichtigung regionaltypischer Hiebsverteilungen und Aushaltungsbesonderheiten, sowie realistischer baumarten- und verfahrensbezogener Leistungsdaten von Holzerntemaschinen für den gew?hlten Durchmesserbereich. Grunds?tzlich aber gilt: Komplexe Sortier- und Bewertungsf?lle bedürfen nach wie vor der individuellen PC-L?sung. Eine Weiterentwicklung der Basissoftware (Programm HOLZERNTE) und des zugrundeliegenden waldme?kundlich-biometrischen Methodenapparats ist in Teilbereichen geplant.      

System of rice intensification increases rice productivity on saline soil

The acidic condition of soil intervened crop growth, especially for rice crop. This research aimed to examine whether application of SRI method on saline soil can improve the productivity of rice. This research applied SRI method in the hinterland of mangrove forest areas around Segara Anakan Lagoon of Indonesia through modified irrigation to reduce saline water intrusion. SRI along with deep furrows in this first implementation had reduced the use of synthetic fertilizers by 40%, reduced variable costs by 8.35%, increased the B/C ratio by 95% and crop productivity by 76% compared to the control methods and increased the B/C ratio by 161% and crop productivity by 133% compared to conventional methods. The farmer’s motivation to apply SRI along with deep furrows for both N-Ach and N-Aff majority was distributed from moderate to high.