Climate change amplifies plant invasion hotspots in Nepal

Aim Climate change has increased the risk of biological invasions, particularly by increasing the climatically suitable regions for invasive alien species. The distribution of many native and invasive species has been predicted to change under future climate. We performed species distribution modelling of invasive alien plants (IAPs) to identify hotspots under current and future climate scenarios in Nepal, a country ranked among the most vulnerable countries to biological invasions and climate change in the world. Location Nepal. Methods We predicted climatically suitable niches of 24 out of the total 26 reported IAPs in Nepal under current and future climate (2050 for RCP 6.0) using an ensemble of species distribution models. We also conducted hotspot analysis to highlight the geographic hotspots for IAPs in different climatic zones, land cover, ecoregions, physiography and federal states. Results Under future climate, climatically suitable regions for 75% of IAPs will expand in contrast to a contraction of the climatically suitable regions for the remaining 25% of the IAPs. A high proportion of the modelled suitable niches of IAPs occurred on agricultural lands followed by forests. In aggregation, both extent and intensity (invasion hotspots) of the climatically suitable regions for IAPs will increase in Nepal under future climate scenarios. The invasion hotspots will expand towards the high‐elevation mountainous regions. In these regions, land use is rapidly transforming due to the development of infrastructure and expansion of tourism and trade. Main conclusions Negative impacts on livelihood, biodiversity and ecosystem services, as well as economic loss caused by IAPs in the future, may be amplified if preventive and control measures are not immediately initiated. Therefore, the management of IAPs in Nepal should account for the vulnerability of climate change‐induced biological invasions into new areas, primarily in the mountains

Experimental study on durability of CFRP-concrete bond subjected to temperature, humidity and outdoor environment

© 2013 International Institute for FRP in Construction. This paper presents experimental results and observations to-date of an ongoing research undertaken to investigate the long-term behaviour of bond between externally bonded Carbon Fibre Reinforced polymer (CFRP) and concrete. Carbon FRP strips were externally bonded to concrete prisms and were exposed separately to three different environmental conditions, namely, temperature, humidity and outdoor environment for extended durations. Single-lap-joint shear test (pull-out test) was conducted to investigate bond strengths of control (unexposed) and exposed specimens. Moreover, material characterisation of concrete cylinders and CFRP control and exposed coupons was carried out to observe the changes of mechanical properties with the time of exposure. Finally, experimental results of exposed specimens were compared to those of control specimens in terms of bond strengths and failure modes. Based on the results to-date, the most significant degradation of bond strength was observed in specimens exposed to outdoor environment. Whereas no significant effect of temperature cycles were found provided that the temperature is below the glass transition temperature of epoxy resin

Pull-out Strengths of GFRP-Concrete Bond Exposed to Applied Environmental Conditions

© 2016, The Author(s). This paper presents results of an experimental investigation on the behaviour of bond between external glass fibre reinforced polymer reinforcement and concrete exposed to three different environmental conditions, namely, temperature cycles, wet–dry cycles and outdoor environment separately for extended durations. Single shear tests (pull-out test) were conducted to investigate bond strengths (pull-out strengths) of control (unexposed) and exposed specimens. Effect of the exposure conditions on the compressive strength of concrete were also investigated separately to understand the effect of changing concrete compressive strength on the pull-out strength. Based on the comparison of experimental results of exposed specimens to control specimens in terms of bond strengths, failure modes and strain profiles, the most significant degradation of pull-out strength was observed in specimens exposed to outdoor environment, whereas temperature cycles did not cause any deterioration of strength

Comparative local analysis of metabolites, lipids and proteins in intact fish tissues by LAESI mass spectrometry

Direct mass spectrometric analysis of animal tissues is an emerging field enabled by recent developments in ambient ion sources. Label-free in situ analysis of metabolites, lipids, and peptides/proteins from intact tissues in whole fish specimens of different gender and age were performed by laser ablation electrospray ionization (LAESI) mass spectrometry (MS). Hypertrophied glandular tissue (gill gland) of adult male Aphyocharax anisitsi (bloodfin tetra) was compared with gill tissues in females of the same species. Comparison of a large number of sample-specific ions was aided by a multivariate statistical method based on orthogonal projections to latent structures discriminant analysis. More than 200 different ions were detected in the mass spectra corresponding to primary metabolites, hormones, lipids and peptides/proteins. The gill tissues of the sexually mature males exhibited multiply charged ions in the 6+ to 10+ charge states corresponding to a protein with a molecular weight of 11 380 Da. This protein was present only in the mature male gill glands but absent in the corresponding area of the female and immature male specimens. An additional nine proteins were detected by LAESI-MS in both the male and female gill tissues

VISITOR PREFERENCES AND VALUES FOR WATER-BASED RECREATION: A CASE STUDY OF THE OCALA NATIONAL FOREST

We used the open-ended contingent valuation method to elicit willingnes to pay (WTP) for day visitors and extended visitors on the Ocala National Forest (ONF), Florida. A Tobit model specification was applied to account for the issues involved with censored WTP bids. The results reveal that visitors would pay more for improved recreational facilities at the ONF. In particular, our estimates show that visitors would pay $1 million for basic facilities,$1.9 million for moderate improvements, and $2.5 million for more improvements.contingent valuation, Tobit analysis, water-based recreation, Resource /Energy Economics and Policy, Q23, Q26,

Free charges versus excitons: photoluminescence investigation of InGaN/GaN multiple quantum well nanorods and their planar counterparts

InGaN/GaN multiple quantum well (MQW) nanorods have demonstrated significantly improved optical and electronic properties compared to their planar counterparts. However, the exact nature of the processes whereby nanorod structures impact the optical properties of quantum wells is not well understood, even though a variety of mechanisms have been proposed. We performed nanoscale spatially resolved, steady-state, and time-resolved photoluminescence (PL) experiments confirming that photoexcited electrons and holes are strongly bound by Coulomb interactions (i.e., excitons) in planar MQWs due to the large exciton binding energy in InGaN quantum wells. In contrast, free electron–hole recombination becomes the dominant mechanism in nanorods, which is ascribed to efficient exciton dissociation. The nanorod sidewall provides an effective pathway for exciton dissociation that significantly improves the optical performance of InGaN/GaN MQWs. We also confirm that surface treatment of nanorod sidewalls has an impact on exciton dissociation. Our results provide new insights into excitonic and charge carrier dynamics of quantum confined materials as well as the influence of surface states

Grain Yield Stability of Early Maize Genotypes

The objective of this study was to estimate grain yield stability of early maize genotypes. Five early maize genotypes namely Pool-17, Arun1EV, Arun-4, Arun-2 and Farmer's variety were evaluated using Randomized Complete Block Design along with three replications at four different locations namely Rampur, Rajahar, Pakhribas and Kabre districts of Nepal during summer seasons of three consecutive years from 2010 to 2012 under farmer's fields. Genotype and genotype × environment (GGE) biplot was used to identify superior genotype for grain yield and stability pattern. The genotypes Arun-1 EV and Arun-4 were better adapted for Kabre and Pakhribas where as pool-17 for Rajahar environments. The overall findings showed that Arun-1EV was more stable followed by Arun-2 therefore these two varieties can be recommended to farmers for cultivation in both environments

Effect of Heat Stress on Crossbred Dairy Cattle in Tropical Nepal: Impact on Blood Parameters

Chitwan district of Nepal has been known as the dairy kingdom of the country considering its strategic location andpotential to easily provision inputs and produce as well as market quality milk across the country. However, theclimate especially during summer has been a challenge to farmers that potentially compromise the daily milk yieldof cows. Therefore, sixteen crossbred dairy cattle were placed in a RCBD fashion to assess the impacts of cold waterbathing in ameliorating effect of heat stress on their performance and body physiology. Routine assessment of themicroclimate within the experimental shed and blood parameters was made. The results from the experimentinferred that frequency of bathing (none, once, twice or thrice a day) did not have any significant impact onHaemoglobin, Haematocrit, Sodium, Potassium, Chloride and Bicarbonate levels in the blood plasma(p>0.05). Inaddition, the animals did not exhibit any signs of physiological distress clinically either. A detailed study scopingtemperature humidity index and over a number of other milk and blood parameters are to be tested across a numberof other available breeds too in order for the researchers to come to a meaningful strategy to beat the heat stress