Surgical implantation of temperature‐sensitive transmitters and data‐loggers to record body temperature in koalas (Phascolarctos cinereus)          下载免费PDF全文

D Adam  SD Johnston  L Beard  V Nicholson  A Lisle  J Gaughan  R Larkin  P Theilemann  A Mckinnon  W Ellis 《Australian veterinary journal》2016,94(1-2):42-47

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Mechanisms of Action and Dose-Response Relationships Governing Biological Control of Fusarium Wilt of Tomato by Nonpathogenic Fusarium spp     

Larkin RP  Fravel DR 《Phytopathology》1999,89(12):1152-1161

ABSTRACT Three isolates of nonpathogenic Fusarium spp. (CS-1, CS-20, and Fo47), previously shown to reduce the incidence of Fusarium wilt diseases of multiple crops, were evaluated to determine their mechanisms of action and antagonist-pathogen inoculum density relationships. Competition for nutrients, as represented by a reduction in pathogen saprophytic growth in the presence of the biocontrol isolates, was observed to be an important mechanism of action for isolate Fo47, but not for isolates CS-1 and CS-20. All three biocontrol isolates demonstrated some degree of induced systemic resistance in tomato (Lycopersicon esculentum) and watermelon (Citrullus lanatus) plants, as determined by split-root tests, but varied in their relative abilities to reduce disease. Isolate CS-20 provided the most effective control (39 to 53% disease reduction), while Fo47 provided the least effective control (23 to 25% reduction) in split-root tests. Dose-response relationships also differed considerably among the three biocon-trol isolates, with CS-20 significantly reducing disease incidence at antagonist doses as low as 100 chlamydospores per g of soil (cgs) and at pathogen densities up to 10(5) cgs. Isolate CS-1 also was generally effective at antagonist densities of 100 to 5,000 cgs, but only when pathogen densities were below 10(4) cgs. Isolate Fo47 was effective only at antagonist densities of 10(4) to 10(5) cgs, regardless of pathogen density. Epidemiological dose-response models (described by linear, negative exponential, hyperbolic saturation [HS], and logistic [LG] functions) fit to the observed data were used to quantify differences among the biocontrol isolates and establish biocontrol characteristics. Each isolate required a different model to best describe its dose-response characteristics, with the HS/HS, LG/HS, and LG/LG models (pathogen/biocontrol components) providing the best fit for isolates CS-1, CS-20, and Fo47, respectively. Model parameters (defining effective biocontrol dose (ED(50)) indicated an ED(50) of 2.6, 36.3, and 2.1 x 10(6) cgs and estimates of biocontrol efficiency of 0.229, 0.539, and 0.774 for isolates CS-1, CS-20, and Fo47, respectively. Differences in dose-response relationships among the biocontrol isolates were attributed to differences in their mechanisms of action, with CS-20 and CS-1 functioning primarily by induced resistance and Fo47 functioning primarily by competition for nutrients.  相似文献   

Laboratory identification of bacterial pathogens of aquatic animals   总被引：1，自引：0，他引：1  

J C Glorioso  R L Amborski  J M Larkin  G F Amborski  D C Culley 《American journal of veterinary research》1974,35(3):447-450

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The impact of thematic resolution on the patch-mosaic model of natural landscapes   总被引：1，自引：1，他引：0  

Guillermo Castilla  Kerry Larkin  Julia Linke  Geoffrey J. Hay 《Landscape Ecology》2009,24(1):15-23

We argue that thematic resolution, i.e., the level of categorical detail of a thematic map expressed by the number of classes included in the map legend, is an inherent component of the scale at which a landscape is analyzed. Changing the number of classes can change the configuration of the patch mosaic as much as changing the grain does. We address recent calls in this and other journals to deepen research in this topic. In particular, we report how thematic resolution affects the patchiness of mosaics representing natural landscapes, which have seldom been studied in this respect. We selected seven 50 × 50 km landscapes within national parks, each representative of a world biome. We applied an object-based unsupervised classification to Landsat TM imagery of these landscapes using increasing numbers of classes, between 2 and 50, and derived curves of mean patch size and patch density for each site. Our results are consistent with previous findings in that the patchiness of output mosaics increases monotonically with increasing thematic resolution, with a higher rate of increase up to eight classes that declines until it becomes roughly constant for more than 16 classes. However, this constant rate of increase is still considerable, meaning that, at least for natural landscapes, there is no threshold beyond which the patch-mosaic model is independent of the conceptual filter applied. This dependence on human fiat calls for re-thinking the patch-mosaic paradigm.  相似文献   

Preliminary observations on the tank and pond culture of the glass eels of the Australian shortfin eel, Anguilla australis Richardson     

B A Ingram  G J Gooley  S S De Silva  B J Larkin  & R A Collins 《Aquaculture Research》2001,32(10):833-848

There is expanding interest in the culture of the Australian shortfin eel Anguilla australis Richardson; however, there is a lack of fundamental biology and husbandry information necessary to further develop an industry within Australia. The present study was undertaken to gain a preliminary understanding of basic husbandry requirements for rearing of juvenile A. australis (glass eels and elvers) in tanks and earthen ponds. Newly caught glass eels were successfully acclimated to culture conditions. During tank culture trials, specific growth rates (SGR) and survival rates ranged from ?2.1 to 2.8% day^?1 and 52% to 100% respectively. Glass eels weaned onto a commercial eel diet exhibited a significantly greater SGR and survival rate than those weaned onto a commercial trout diet. Glass eels weaned onto an eel diet over a 15‐day period grew slightly faster than eels weaned over a 5‐day period, but survival rates were not significantly different for each treatment. SGRs (up to 2.8% day^?1) were significantly higher for glass eels fed at 9 and 12% day^?1 than at 6% day^?1. Stocking densities between 2.5 kg m^?3 and 30 kg m^?3 did not influence either SGR or survival rates. SGRs were significantly higher for glass eels cultured at 25 °C than at lower temperatures. During pond culture trials, SGRs and survival rates ranged from 1.36 to 1.65% day^?1 and 39% to 77% respectively. The SGR and survival rates of juvenile eels stocked into ponds receiving supplementary feeding with a commercial eel diet were not significantly different to those of eels stocked into ponds that did not receive supplementary feeding.  相似文献   

Volume and Value of Marine Ornamentals Collected in Florida, 1990–98     

Charles M. Adams  Sherry L. Larkin  Donna J. Lee 《Aquarium Sciences and Conservation》2001,3(1-3):25-36

The marine life fishing industry in Florida is defined by the state as the non-lethal harvest of marine plants, finfish, and invertebrates that are sold live for commercial purposes (primarily into the saltwater aquarium industry). Approximately 330 different species of finfish and invertebrates are harvested by marine life collectors in Florida, including 180 species of finfish and 150 species of invertebrates and plants. In 1998, the total dockside value of these species was approximately US$1.9 million. The industry is highly regulated via limits on gear, handling methods, harvest sizes, and trip/bag/possession limits. Entry into the industry has been recently curtailed by the implementation of a moratorium on marine life endorsements. The total number of licensed harvesters exceeded 700 in 1998. Approximately 70 wholesales buyers also participated in the market during 1998. The majority of the dockside value is generated in south Florida, with the majority of the remaining value accruing from the region including and north of Tampa Bay. Over 80% of the total value associated with both finfish and invertebrates is generated by only 10 species within each group. Dockside prices vary considerably among the various species landed, with those landed in greater volumes exhibiting the lower prices.  相似文献   

The U.S. Wholesale Market for Marine Ornamentals     

Sherry L. Larkin  Robert L. Degner 《Aquarium Sciences and Conservation》2001,3(1-3):13-24

The market for marine ornamentals encompasses all live marine species (fish and invertebrates) destined for the aquarium trade. In 1998, U.S. imports and exports were valued at approximately US $1.5 billion at the border (all dollar values cited in this paper are $US). In Florida, cultured freshwater and collected saltwater species accounted for $70 million and $4 million, respectively, in annual dockside revenue. To help explain Florida's marine landings and provide suggestions for future resource management and market campaigns that reflect the perceptions of the industry, a survey of wholesalers was initiated in 1999. Preliminary results indicate that there are several intermediate wholesale markets. Florida firms are closer to the supply as many also collect. Wholesalers in other states handle more freshwater product, are larger, and tend to import a larger share of their inventory. Consolidation is expected to continue, but niche markets for eco-friendly firms are expected to grow. In Florida, marketing strategies should focus on the observed higher survival rates and increasing supply of the popular invertebrate species. Many wholesalers are concerned about additional regulations that could reduce the number of collectors and thereby increase supply variability, a noted weakness of the Florida industry.  相似文献   

Development and characterization of common wheat-Thinopyrum intermedium translocation lines with resistance to barley yellow dwarf virus     

Z.Y. Xin  Z.Y. Zhang  X. Chen  Z.S. Lin  Y.Z. Ma  H.J. Xu  P.M. Banks  P.J. Larkin 《Euphytica》2001,119(1-2):163-167

We developed some wheat-Th. intermedium translocation lines,Yw642, Yw443 and Yw243, etc., showing good BYDV resistance from L1by induced homoeologous pairing using CS ph mutant. Characterization ofthese wheat lines was carried out by GISH and RFLP analysis. The resultsof GISH showed that the lines, YWw42, Yw443 and Yw243, etc., arehomozygous wheat-Th. intermedium translocation lines, in which thechromosome segments of Th. intermedium were transferred to thedistal end of a pair of wheat chromosomes. RFLP analysis indicated that thetranslocation chromosome of the wheat lines is T7DS · 7DL-7XL. Thebreakpoint of the translocation is located on the distal end of 7DL, betweenXpsr965 and Xpsr680 about 90–99 cm from the centromere. The BYDVgene is located on the distal end of 7XL around Xpsr680, Xpsr687 andXwg380. The RFLP markers of psr680, psr687 and wg380 werecosegregated with the BYDV resistance respectively and could be used formolecular assisted selection (MAS) in wheat breeding program for BYDVresistance.  相似文献   

"Coulomb Staircase" at Room Temperature in a Self-Assembled Molecular Nanostructure     

RP Andres  T Bein  M Dorogi  S Feng  JI Henderson  CP Kubiak  W Mahoney  RG Osifchin  R Reifenberger 《Science (New York, N.Y.)》1996,272(5266):1323-1325

Double-ended aryl dithiols [alpha,alpha'-xylyldithiol (XYL) and 4,4'-biphenyldithiol] formed self-assembled monolayers (SAMs) on gold(111) substrates and were used to tether nanometer-sized gold clusters deposited from a cluster beam. An ultrahigh-vacuum scanning tunneling microscope was used to image these nanostructures and to measure their current-voltage characteristics as a function of the separation between the probe tip and the metal cluster. At room temperature, when the tip was positioned over a cluster bonded to the XYL SAM, the current-voltage data showed "Coulomb staircase" behavior. These data are in good agreement with semiclassical predictions for correlated single-electron tunneling and permit estimation of the electrical resistance of a single XYL molecule (approximately18 ± 12 megohms).  相似文献   

Dynamics of mammalian chromosome evolution inferred from multispecies comparative maps     

Murphy WJ  Larkin DM  Everts-van der Wind A  Bourque G  Tesler G  Auvil L  Beever JE  Chowdhary BP  Galibert F  Gatzke L  Hitte C  Meyers SN  Milan D  Ostrander EA  Pape G  Parker HG  Raudsepp T  Rogatcheva MB  Schook LB  Skow LC  Welge M  Womack JE  O'brien SJ  Pevzner PA  Lewin HA 《Science (New York, N.Y.)》2005,309(5734):613-617

The genome organizations of eight phylogenetically distinct species from five mammalian orders were compared in order to address fundamental questions relating to mammalian chromosomal evolution. Rates of chromosome evolution within mammalian orders were found to increase since the Cretaceous-Tertiary boundary. Nearly 20% of chromosome breakpoint regions were reused during mammalian evolution; these reuse sites are also enriched for centromeres. Analysis of gene content in and around evolutionary breakpoint regions revealed increased gene density relative to the genome-wide average. We found that segmental duplications populate the majority of primate-specific breakpoints and often flank inverted chromosome segments, implicating their role in chromosomal rearrangement.  相似文献