Identification of case clusters and counties with high infective connectivity in the 2001 epidemic of foot-and-mouth disease in Uruguay     

Chowell G  Rivas AL  Smith SD  Hyman JM 《American journal of veterinary research》2006,67(1):102-113

OBJECTIVE: To evaluate the influence of individual spatial units (ie, counties) on the epidemic spread of foot-and-mouth disease (FMD) virus. SAMPLE POPULATION: 163 counties in Uruguay where there was an outbreak of FMD between April 23 and July 11, 2001. PROCEDURE: A geographically referenced database was created, and the distance between counties (13,203 county pairs), road density of counties (163 counties), and time when cases were reported in those counties (11 weeks of the epidemic) were considered to assess global spatial and spatial-temporal autocorrelation, determine the contribution of links connecting pairs of counties with infected animals, and allow us to hypothesize the influence for spread during the epidemic for counties with greater than the mean infective link contributions. RESULTS: Case clusters were indicated by the Moran Iand Mantel tests during the first 6 weeks of the epidemic. Spatial lags between pairs of counties with infected animals revealed case clustering before and after vaccination was implemented. Temporal lags predicted autocorrelation for up to 3 weeks. Link indices identified counties expected to facilitate epidemic spread. If control measures had been implemented in counties with a high index link (identifiable as early as week 1 of the epidemic), they could have prevented (by week 11 of the epidemic) at least 2.5 times as many cases per square kilometer than the same measures implemented in counties with average link indices. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of spatial autocorrelation and infective link indices may identify network conditions that facilitate (or prevent) disease spread.  相似文献   

Polyostotic lymphoma with vertebral involvement and spinal extradural compression in a dog     

Lamagna B  Lamagna F  Meomartino L  Paciello O  Fatone G 《Journal of the American Animal Hospital Association》2006,42(1):71-76

A 10-year-old, male, mixed-breed dog that developed cervical pain and neurological deficits was diagnosed with primary lymphoma of the second cervical vertebra. The cervical lesion was not surgically resectable. A dorsal cervical hemilaminectomy was performed to provide temporary decompression. The dog had complete pain relief after surgery but was euthanized 6 weeks later with recurrent clinical signs and evidence of lymphoma in the right femur.  相似文献   

Genetic diversity of maize (<Emphasis Type="Italic">Zea mays</Emphasis> L. ssp. <Emphasis Type="Italic">mays</Emphasis>) in communities of the western highlands of Guatemala: geographical patterns and processes     

Jacob van Etten  Mario Roberto Fuentes López  Luis Gerardo Molina Monterroso  Karla Melina Ponciano Samayoa 《Genetic Resources and Crop Evolution》2008,55(2):303-317

  相似文献   

Bilaterian burrows and grazing behavior at >585 million years ago     

Pecoits E  Konhauser KO  Aubet NR  Heaman LM  Veroslavsky G  Stern RA  Gingras MK 《Science (New York, N.Y.)》2012,336(6089):1693-1696

Based on molecular clocks and biomarker studies, it is possible that bilaterian life emerged early in the Ediacaran, but at present, no fossils or trace fossils from this time have been reported. Here we report the discovery of the oldest bilaterian burrows in shallow-water glaciomarine sediments from the Tacuarí Formation, Uruguay. Uranium-lead dating of zircons in cross-cutting granite dykes constrains the age of these burrows to be at least 585 million years old. Their features indicate infaunal grazing activity by early eumetazoans. Active backfill within the burrow, an ability to wander upward and downward to exploit shallowly situated sedimentary laminae, and sinuous meandering suggest advanced behavioral adaptations. These findings unite the paleontological and molecular data pertaining to the evolution of bilaterians, and link bilaterian origins to the environmental changes that took place during the Neoproterozoic glaciations.  相似文献   

Add ecology to the pre-medical curriculum     

Beck C  Klemow K  Paulson J  Bernstein A  Lam M  Middendorf G  Reynolds J  Belanger K  Cardelus C  Cid C  Doshi S  Gerardo N  Jablonski L  Kimmel H  Lowman M  Macrae-Crerar A  Pohlad B  de Roode J  Thomas C 《Science (New York, N.Y.)》2012,335(6074):1301

  相似文献   

Root system of Quercus suber L. seedlings in response to herbaceous competition and different watering and fertilisation regimes     

Elena Cubera  Gerardo Moreno  Alejandro Solla  Manuel Madeira 《Agroforestry Systems》2012,85(2):205-214

Different management practices are commonly applied to increase pasture yield of Mediterranean open woodlands, but the consequences of increasing competition for soil resources with these practices on tree recruitment are still unknown. In a greenhouse study, belowground competition of Quercus suber L. seedlings growing together with natural (Oak_NP) or improved pasture (Oak_IP) was evaluated, and their root systems compared with those of seedlings growing in bare soil (Oak_BS). Two watering levels and two regimes of P₂O₅ fertilisation were also tested. Because of competition, the Oak_IP seedlings had their fine root mass density, coarse root length, and shoot mass reduced by up to 40, 36, and 39%, respectively, when compared to Oak_NP seedlings. Oak_NP and Oak_BS seedlings showed similar average root density parameters and shoot mass values, indicating that Q. suber seedlings growing with natural pasture is a low competitive system. High availability of water and phosphorus did not mitigate the strength of competition between herbaceous plants and oak seedlings, and favoured the pasture to the detriment of the trees. Our findings suggest that P₂O₅ fertilisation and irrigation practices performed to improve herbaceous productivity will negatively influence recruitment of Q. suber seedlings.  相似文献   

Evaluation of variables to describe the shape of volumetric capnography curves during bronchoconstriction in dogs     

Mosing M  Iff I  Hirt R  Moens Y  Tusman G 《Research in veterinary science》2012,93(1):386-392

The aim of the study was to investigate changes in volumetric capnography (V(C)) variables during bronchoconstriction in dogs and compare it with total respiratory resistance (R(L)) measured with a Fleisch pneumotachograph. Six dogs were challenged with increasing concentrations of carbachol until obvious signs of bronchoconstriction were seen. All V(C) parameters were obtained before, directly after, 10 and 20 min after maximal bronchoconstriction. The slope of phase III (SIII) and airway and alveolar dead space parameters were significantly different from baseline directly after the challenge. The V(C) curve obtained a typical shape at the time of maximal bronchoconstriction and a trend to return to baseline shape was seen over time. A significant correlation was found for all aforementioned parameters with R(L). We conclude that the shape of the V(C) curve in combination with dead space calculation can be used to verify bronchoconstriction on a breath-to-breath basis.  相似文献   

Influence of sexually inactive bucks subjected to long photoperiod or testosterone on the induction of estrus in anovulatory goats     

Luna-Orozco JR  Guillen-Muñoz JM  De Santiago-Miramontes Mde L  García JE  Rodríguez-Martínez R  Meza-Herrera CA  Mellado M  Véliz FG 《Tropical animal health and production》2012,44(1):71-75

The objective of this study was to evaluate the efficacy of treating sexually inactive bucks with artificial long photoperiod or testosterone on the induction of estrus in anovulatory grazing goats. A total of 91 multiparous mixed-breed anestrous goats were randomly assigned to one of three treatment groups: (1) joining with bucks subjected to 2.5 month of artificial long days (16 h of light/day; n = 31), (2) joining with testosterone-treated bucks (n = 30), and (3) joining with untreated bucks (control; n = 30). There were no differences between the light-treated (100%) and testosterone-treated (93%) bucks in their ability to induce estrus in anovulatory does. On the other hand, none of the goats in contact with control bucks exhibited estrus. The interval from start of mating to estrus was shorter in goats with the light-treated bucks (37.9 ± 4.8 h) compared with does in contact with testosterone-treated bucks (58.3 ± 8.7 h). The overall pregnancy rate in goats joined with light-treated, testosterone-treated and control bucks was 84%, 77% and 0%, respectively, with no difference (P > 0.05) between the first two groups. Anogenital sniffing, approaches, mounting attempts, and mounts were highest (P < 0.01) in light-treated bucks and lowest in control bucks. It was concluded that testosterone-treated bucks and long-day-treated bucks were equally effective in synchronizing estrus in anovulatory goats and resulted in similar levels of fertility. Given that light-treated bucks are unviable in communal production systems of goats raised by resource-poor farmers, the sexual arousal of bucks with testosterone is a practical and reliable method to induce ovulation in anovulatory goats in pastoral goat systems in hot environments.  相似文献   

QTL analysis of main and epistatic effects for flour color traits in durum wheat     

Pablo F. Roncallo  Gerardo L. Cervigni  Carlos Jensen  Rubén Miranda  Alicia D. Carrera  Marcelo Helguera  Viviana Echenique 《Euphytica》2012,185(1):77-92

The aim of this work was to map quantitative trait loci (QTLs) associated with flour yellow color (Fb*) and yellow pigment content (YPC) in durum wheat (Triticum turgidum L. var. durum). Additionally, QTLs affecting flour redness (Fa*) and brightness (FL*) color parameters were investigated. A population of 93 RILs (UC1113 × Kofa) was evaluated in three locations of Argentina over 2 years. High heritability values (>94%) were obtained for Fb* and YPC, whereas FL* and Fa* showed intermediate to high values. The main QTLs affecting Fb* and YPC overlapped on chromosome arms 4AL (4AL.2), 6AL (6AL.2), 7AS, 7AL, 7BS (7BS.2) and 7BL (7BL.2). The 7BL.1 QTL included the Psy-B1 locus, but one additional linked QTL was detected. A novel minor QTL located on 7AS affected Fb*, with an epistatic effect on YPC. An epistatic interaction occurred between the 7AL and 7BL.2 QTLs. The 4AL.2 QTL showed a strong effect on Fb* and was involved in two digenic epistatic interactions. The 6AL.2 QTL explained most of the variation for Fb* and YPC. The main QTLs affecting FL* and Fa* were located on 2BS and 7BL, respectively. These results confirm the complex inheritance of flour color traits and open the possibility of developing perfect markers to improve pasta quality in Argentinean breeding programs.  相似文献   

Eco-friendly Production of Metallic Nanoparticles in Polymeric Solutions and Their Processing into Biocompatible Composites     

Alejandra Pérez-Nava  Josué D. Mota-Morales  Zaira Y. García-Carvajal  Sara E. Herrera-Rodríguez  Gerardo Arrevillaga-Boni  Cristy L. Azanza-Ricardo  Milton O. Vazquez-Lepe  J. Betzabe Gonzalez-Campos 《Fibers and Polymers》2018,19(1):156-169

Silver and gold nanoparticles were produced and embedded in poly(vinyl alcohol) (PVA) and chitosan (CTS) solutions by the photoreduction of metallic salt precursors triggered by direct sunlight irradiation, in which the polymers acted as reducing, dispersing and stabilizing agents. Sunlight photoreduction can be standardized using a constant UV index regardless of the season. This strategy was found to be an improvement over other common energy sources used to trigger the reduction of metal ions, including UV light irradiation and high-temperature reduction with mechanical stirring. The resulting PVA/metal nanoparticle and CTS/metal nanoparticle composite solutions were processed into thin films and nanofiber composites. In vitro testing of the cytotoxicity and biocompatibility demonstrates that the film composites are non-toxic and biocompatible with the HT-29 human colon cancer cell line. Promotion of HT-29 cell growth using our hybrid composites was observed, in contrast to other studies in which colloidal NPs were tested. Therefore, a sustainable approach for the onestep preparation of biocompatible polymer/metallic nanoparticle composites is reported.  相似文献