398 research outputs found
Landslide Susceptibility Assessment Using Modified Frequency Ratio Model in Kaski District, Nepal
Landslides are the most common natural hazards in Nepal especially in the mountainous terrain. The existing topographical scenario, complex geological settings followed by the heavy rainfall in monsoon has contributed to a large number of landslide events in the Kaski district. In this study, landslide susceptibility was modeled with the consideration of twelve conditioning factors to landslides like slope, aspect, elevation, Curvature, geology, land-use, soil type, precipitation, road proximity, drainage proximity, and thrust proximity. A Google-earth-based landslide inventory map of 637 landslide locations was prepared using data from Disinventar, reports, and satellite image interpretation and was randomly subdivided into a training set (70%) with 446 Points and a test set with 191 points (30%). The relationship among the landslides and the conditioning factors were statistically evaluated through the use of Modified Frequency ratio analysis. The results from the analysis gave the highest Prediction rate (PR) of 6.77 for elevation followed by PR of 6.45 for geology and PR of 6.38 for the landcover. The analysis was then validated by calculating the Area Under a Curve (AUC) and the prediction rate was found to be 68.87%. The developed landslide susceptibility map is helpful for the locals and authorities in planning and applying different intervention measures in the Kaski District
Detection of Ascosphaera apis, causing chalkbrood disease in the colonies of European honey bee, Apis mellifera in West Bengal, India
The decline of honey bee (Apis mellifera L.) populations is of great concern around the world. Among the several key drivers, dissemination of pests and pathogens is potential one. Chalkbrood is very common fungal disease of honey bee, caused due to Ascosphaera apis. In the present study, survey was conducted regarding the prevalence of diseases in A. mellifera beekeeping in Gangetic plains of West Bengal, India. Results confirmed the occurrence of chalkbrood disease in different apiaries, where dead and mummified bee larvae with cotton like chalky white or greyish-black covering were found as physical symptoms of the disease. From three surveyed apiaries, a total of 16 hives out of 113 hives were found to be infected with the diseases; and 46 frames out of 132 frames from the infected 16 hives were found to be affected by the pathogen. Microscopic examination reflected that nearly 87% of the samples collected from the infected frame were found to be positive for the spore of Ascosphaera. The fungus associated with the disease was isolated on Potato Dextrose Agar medium, pure cultured and its genomic DNA was isolated to perform PCR and based on 18s rDNA sequencing by using specific primer pair of ITS-1 and ITS-4, the fungus was identified as Ascosphaera apis.
Keywords: 18s rDNA, Bees, Necrotrophs, Phylogen
Desert locust and its management in Nepal: a review
Locusts are among the most dangerous agricultural pests. They are a group of short horned grasshoppers belonging to Acrididae family and are hemimetabolous insects. This group of grasshoppers have a unique character of changing habits and behaviors when they aggregate in a group and this habit is catalyzed by different environmental factors. In the adult stage, gregarious locusts migrate from one place to another in a swarm. Desert Locust, Schistocerca gregaria (Forksal), is one of those locusts which cause damage to different types of crop which fly in the direction of wind up to a distance of 150 km. Because of polyphagous feeding habits and swarming in a plague (large group of adults), this pest is considered as the hazardous migratory pest. These pests entered Nepal for the first time in 1962 and then in 1996. In 2020 the pest entered the country from India on three different dates 27th June and continued till 29th (5 districts), 12th July (1 district), and 16th July (2 districts). The swarms migrated to 53 districts and caused the considerable loss in agricultural and field crop in 1118 hectare. These pests are monitored on the basis of environmental factors and many tools and practices such as eLocust3, SMELLS (Soil Moisture for Desert Locust Early Survey), P-locust and SUPARCO Disaster Watch Desert Locust Situation Alert are being used. Their control is critical to food security. Many tools and techniques are integrated for prevention and management of these pests to minimize damage in the existing crops where they migrate. These are physical methods, cultural methods, use of botanicals, green muscle, PAN (phenylacetonitrile) and chemicals. Effective preventive management strategy relies on an improved knowledge of the pest biology, more efficient monitoring and control techniques
Assessment of clinical profile, antibiotic sensitivity and prescription pattern in blood culture positive enteric fever among pediatric and adult patients admitted in a tertiary care hospital: a prospective study
Background: Asterion Introduction: Enteric fever is a major concern in developing country. It is predominantly caused by serovars typhi and paratyphi of Salmonella enterica. Recently, an upsurge in antimicrobial resistant strains has worsened the management of enteric fever. So, aim of present study is to evaluate the clinical profile, antibiotic sensitivity and prescription pattern in blood culture proven cases of enteric fever in pediatric and adult patients.Methods: Single centre, prospective study was conducted at a tertiary care hospital. Demographic and clinical details of blood culture proven enteric fever admitted in hospital were collected over the period from August 2016 to November 2018.Results: Total 58 blood cultures grew Salmonella spp. , amongst them 84.48 % had growth of Salmonella typhi. Blood culture was sent after a mean period of 9 days and 10 days of fever in pediatric and adult patients respectively. All isolates of S. paratyphi A were pansusceptible, whereas 36.73 % isolates of S. typhi were multidrug resistant and nalidixic acid resistant. 68.97% patients received antibiotics before admission. The difference between mean time to defervescence in patients who received ceftriaxone and those who received more than one antibiotic was not statistically significant. (P value 0.87)Conclusion: Blood cultures are the important diagnostic tool to identify multidrug resistant Salmonellae. Study showed that combination therapy was not statistically superior and awareness of local antimicrobial susceptibility pattern significantly helps for better management of the patients
Predicting the risk of depression among adolescents in Nepal using a model developed in Brazil : the IDEA Project
The burden of adolescent depression is high in low- and middle-income countries (LMICs), yet research into prevention is lacking. Development and validation of models to predict individualized risk of depression among adolescents in LMICs is rare but crucial to ensure appropriate targeting of preventive interventions. We assessed the ability of a model developed in Brazil, a middle-income country, to predict depression in an existing culturally different adolescent cohort from Nepal, a low-income country with a large youth population with high rates of depression. Data were utilized from the longitudinal study of 258 former child soldiers matched with 258 war-affected civilian adolescents in Nepal. Prediction modelling techniques were employed to predict individualized risk of depression at age 18 or older in the Nepali cohort using a penalized logistic regression model. Following a priori exclusions for prior depression and age, 55 child soldiers and 71 war-affected civilians were included in the final analysis. The model was well calibrated, had good overall performance, and achieved good discrimination between depressed and non-depressed individuals with an area under the curve (AUC) of 0.73 (bootstrap-corrected 95% confidence interval 0.62-0.83). The Brazilian model comprising seven matching sociodemographic predictors, was able to stratify individualized risk of depression in a Nepali adolescent cohort. Further testing of the model's performance in larger socio-culturally diverse samples in other geographical regions should be attempted to test the model's wider generalizability
Unzipping flood vulnerability and functionality loss:tale of struggle for existence of riparian buildings
Floods pose significant risk to riparian buildings as evidenced during many historical events. Although structural resilience to tsunami flooding is well studied in the literature, high-velocity and debris-laden floods in steep terrains are not considered adequately so far. Historical floods in steep terrains necessitate the need for flood vulnerability analysis of buildings. To this end, we report vulnerability of riparian-reinforced concrete buildings using forensic damage interpretations and empirical/analytical vulnerability analyses. Furthermore, we propose the concept and implications of functionality loss due to flooding in residential reinforced concrete (RC) buildings using empirical data. Fragility functions using inundation depth and momentum flux are presented for RC buildings considering a recent flooding event in Nepal. The results show that flow velocity and sediment load, rather than hydrostatic load, govern the damages in riparian RC buildings. However, at larger inundation depth, hydrostatic force alone may collapse some of the RC buildings
Assessing the prospects of transboundary multihazard dynamics:The case of Bhotekoshi—Sunkoshi watershed in Sino—Nepal border region
The impacts of multihazards have become more pronounced over the past few decades globally. Multiple hazards and their cascading impacts claim enormous losses of lives, livelihoods, and built environment. This paradigm prompts integrated and multidisciplinary perspectives to identify, characterize, and assess the occurrence of multihazards and subsequently design counter-measures considering impending multihazard scenarios at the local level. To this end, we considered one of the most egregious transboundary watersheds, which is regarded as a multihazard hotspot of Nepal, to analyze the underlying causes and cascade scenarios of multihazards, and their associated impacts. In this paper, geophysical, hydrometeorological, and socioeconomic perspectives are formulated to characterize the watershed from the dimension of susceptibility to multihaz-ard occurrence. To characterize the complex dynamics of transboundary multihazard occurrence, insights have been presented from both the Nepali and the Chinese sides. Individual case studies and the interrelation matrix between various natural hazards are also presented so as to depict mul-tihazard consequences in the transboundary region. The sum of the observations highlights that the watershed is highly vulnerable to a single as well as multiple natural hazards that often switch to disasters
Multi-Hazard Risk Assessment of Kathmandu Valley, Nepal
Natural hazards are complex phenomena that can occur independently, simultaneously, or in a series as cascading events. For any particular region, numerous single hazard maps may not necessarily provide all information regarding impending hazards to the stakeholders for preparedness and planning. A multi-hazard map furnishes composite illustration of the natural hazards of varying magnitude, frequency, and spatial distribution. Thus, multi-hazard risk assessment is performed to depict the holistic natural hazards scenario of any particular region. To the best of the authors’ knowledge, multi-hazard risk assessments are rarely conducted in Nepal although multiple natural hazards strike the country almost every year. In this study, floods, landslides, earthquakes, and urban fire hazards are used to assess multi-hazard risk in Kathmandu Valley, Nepal, using the Analytical Hierarchy Process (AHP), which is then integrated with the Geographical Information System (GIS). First, flood, landslide, earthquake, and urban fire hazard assessments are performed individually and then superimposed to obtain multi-hazard risk. Multi-hazard risk assessment of Kathmandu Valley is performed by pair-wise comparison of the four natural hazards. The sum of observations concludes that densely populated areas, old settlements, and the central valley have high to very high level of multi-hazard risk
Seismic Performance of High-Rise Condominium Building during the 2015 Gorkha Earthquake Sequence
On 25 April 2015, a strong earthquake of magnitude 7.8 struck central Nepal including the capital city, Kathmandu. Several powerful aftershocks of magnitude 6.7, 6.9 and 7.3 together with hundreds of aftershocks of local magnitude greater than 4 hit the same area until May 2015. This earthquake sequence resulted in considerable damage to the reinforced concrete buildings apart from brick and stone masonry constructions. High-rise buildings in Nepal are mainly confined in Kathmandu valley and their performance was found to be in the life safety to collapse prevention level during the Gorkha earthquake sequence. In this paper, seismic performance assessment of a reinforced concrete apartment building with brick infill masonry walls that sustained life safety performance level is presented. Rapid visual assessment performed after the 12 May aftershock (MW 7.3) highlighted the need for detailed assessment, thus, we carried out nonlinear time history analysis using the recorded accelerograms. The building was first simulated for the recorded acceleration time history (PGA = 0.16 g) and the PGA was scaled up to 0.36 g to assess the behaviour of building in the case of the maximum considered earthquake occurrence. The sum of results and observations highlighted that the building sustained minor damage due to low PGA occurrence during the Gorkha earthquake and considerable damage would have occurred in the case of 0.36 g PGA
- …