Landscape setting and risk of Ranavirus mortality events

Amphibian mortality events in relatively pristine and protected settings cause particular concern because they may be linked to larger scale, off-site factors that interact with local landscape features. We used logistic regression and model selection criterion (QAIC_c) to identify landscape features key to predicting disease incidence in Acadia National Park (ANP), Maine, USA. High catchment position was the most important landscape feature associated with larval mortality events in ANP wetlands, and was present in all competing models. No spatial autocorrelation of disease events was observed, suggesting that within our study area, epizootics are not clustered and landscape and within-pond stressors may be more influential in mortality occurrence than vector movement. However, our model may be a considerable underestimate of in-field infection rates because it was based on die-off event incidences and did not include infected reservoirs or vectors. This study provides the first clear connection between landscape position and Ranavirus mortality events. Conservation and disease containment efforts in ANP should be directed toward higher catchment position and headwater wetlands such as vernal pools.     

Functionalization of graphene nanosheets and its dispersion in PMMA/PEO blend: Thermal,electrical, morphological and rheological analyses

Graphene nanoplatelet (GnP) was chemically functionalized by amine groups for improvement of compatibility in poly(methyl methacrylate) (PMMA)/poly(ethylene oxide) (PEO) blend. PMMA/PEO (90/10) nanocomposites with non-functionalized GnP and functionalized GnP (FGnP) were prepared by solution casting method. Successful grafting of amine groups on the GnP surface was confirmed by Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analysis. The Transmission electron microscopy (TEM) images showed that the dispersion state of FGnP was better than that of GnP in PMMA/PEO nanocomposites. The effects of FGnP and GnP on rheological, thermal and electrical properties of PMMA/PEO nanocomposites were investigated by various methods. The results indicated that the FGnP-based nanocomposites had higher storage modulus, glass transition temperature and thermal stability as compared to the GnP-based nanocomposites. The electrical conductivity of the nanocomposites with FGnP was better than that of GnP-based nanocomposites. The higher conductivity was attributed to homogeneous and well dispersion state of FGnP in PMMA/PEO nanocomposites.     

The importance of understanding spatial population structure when evaluating the effects of silviculture on spotted salamanders (Ambystoma maculatum)

Current silvicultural practices in the northeastern United States create diverse vegetation patterns and microclimates that provide a mosaic of terrestrial habitats for amphibian species. We inferred patterns of habitat use by the spotted salamander, Ambystoma maculatum, by studying colonization of four newly created breeding pools each surrounded by four different forest treatments: a control, partial cut, clearcut with coarse woody debris (CWD) removed, and clearcut with CWD retained. Created pools were rapidly colonized, indicating that breeding salamanders readily bred in new pools they encountered. This suggests that in our study area pool-specific philopatry and site fidelity may not be high and that particular pools may not define local breeding populations. In the experimental silvicultural treatments, juvenile salamanders preferred the control forest to the clearcuts, whereas adult salamanders showed no significant preferences among the treatments. Although silvicultural practices such as clearcutting may reduce juvenile movement between pools, inter-pool movement by adults that are more tolerant of habitat change may ameliorate this effect in our study area. If juveniles are the primary life-history stage dispersing between local populations (i.e., moving between more isolated groups of pools), however, there is potential for clearcutting to reduce the connectivity between local populations.     

Effects of nursery environment on needle morphology of Pinus monticola Dougl. and implications for tree improvement programs

Statistically significant differences were found in 14 needle traits of western white pine (Pinus monticola Dougl.) seedlings grown from the same seed orchard source in the three nurseries in northern Idaho. Traits with significant variation included needle length and width, number of stomatal rows, number of stomata per row, total stomata per needle, adaxial surface area, stomatal density, major axes of stomata, stomatal shape, stomatal area, stomatal occlusion, epistomatal wax degradation, weight of wax per dry weight of needle, and the contact angles of water droplets placed on adaxial needle surfaces. Wax crystallites on needle surfaces were hollow and tubular and the amount of surface wax appeared to be associated with surface wettability. Our results may have important implications for tree improvement programs that require successful inoculation of nursery-grown seedlings with spores of Cronartium ribicola J. C. Fisch. ex Rabenh. to reliably screen white pines for resistance to blister rust.     

Transformation of the L-Asparaginase II Gene to Potato Hairy Roots for Production of Recombinant Protein

Journal of Crop Science and Biotechnology - Nowadays, transgenic plants are considered as an expression system for therapeutic recombinant proteins. One of the approaches to recombinant protein...     

Assessment of Iranian wheat germplasm for salinity tolerance using analysis of the membership function value of salinity tolerance (MFVS)

Journal of Crop Science and Biotechnology - Salinity stress is one of the most important abiotic stresses which reduce crop production worldwide. In this study, 17 morphological and agronomic...