118 research outputs found

    Rangelands Management: A Foresight in Afghanistan

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    Afghanistan, a land locked country with arid and semi-arid climatic conditions and the average amount of rainfall is 250 mm per year, heavily depends on the rangelands for livestock feed. Permanent pasture cover around 46% of the total land area i.e. 30 million ha rangeland exist in the country (Thomson et al. 2003), whereas forestry covers around 3% of total area i.e. around 1.9 million ha. Based on seasons, the rangelands of Afghanistan divided into three categories; the winter (16 million ha); the spring and autumn (16 million ha) and summer (22.5 million) pastures. Rangeland degradation is quite severe and widespread problem in Afghanistan (ESCAP, 1983). Overgrazing is a major cause of rangeland degradation in dry areas leading to desertification (FAO, 1993). The reduced plant cover due to overgrazing accelerates soil erosion resulting in loss of fertile topsoil. It adversely affects the productivity as well as biodiversity of the land, and causes for the spread of invasive species of non-native weeds. The destruction of rangeland vegetation of Afghanistan is not recent, dating back to hundreds of years (Pittroff, 2011). Keeping in view these constraints, a foresight survey was conducted to assess current status and future prospects on rangelands in Afghanistan

    Sustainability of Grassland Resources in Afghanistan: A Review

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    Afghanistan is land locked country with arid and semi-arid climatic conditions. Out of 65 million ha of its land area, grassland and pastures cover 30 million ha. The grassland is reducing significantly from last six decades mainly due to poor governance in the last three decades of war and conflict, non-existence of scientific capacity and capability, land encroachment, increasing population, urbanization, poor policies and support from the Government, consistent increase in the population of cattle (291%), goats (160%) and (donkeys 290%) during the last two decades (World Bank, 2011)

    Impact of Cocaine Use on Acute Ischemic Stroke Patients: Insights from Nationwide Inpatient Sample in the United States

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    Cocaine is the third most common substance of abuse after cannabis and alcohol. The use of cocaine as an illicit substance is implicated as a causative factor for multisystem derangements ranging from an acute crisis to chronic complications. Vasospasm is the proposed mechanism behind adverse events resulting from cocaine abuse, acute ischemic strokes (AIS) being one of the few. Our study looked into in-hospital outcomes owing to cocaine use in the large population based study of AIS patients. Using the national inpatient sample (NIS) database from 2014 of United States of America, we identified AIS patients with cocaine use using International Classification of Disease, Ninth Revision (ICD-9) codes. We compared demographics, mortality, in-hospital outcomes and comorbidities between AIS with cocaine use cohort versus AIS without cocaine use cohort. Acute ischemic strokes (AIS) with cocaine group consisted of higher number of older patients (\u3e 85 years) (25.6% versus 18.7%, p \u3c 0.001) and females (52.4% versus 51.0%, p \u3c 0.001). Cocaine cohort had higher incidence of valvular disorders (13.2% versus 9.7%, p \u3c 0.001), venous thromboembolism (3.5% versus 2.6%, p \u3c 0.03), vasculitis (0.9% versus 0.4%, p \u3c 0.003), sudden cardiac death (0.4% versus 0.2%, p \u3c 0.02), epilepsy (10.1% versus 7.4%, p \u3c 0.001) and major depression (13.2% versus 10.7%, p \u3c 0.007). The multivariate logistic regression analysis found cocaine use to be the major risk factor for hospitalization in AIS cohort. In-hospital mortality (odds ratio (OR)= 1.4, 95% confidence interval= 1.1-1.9, p \u3c 0.003) and the disposition to short-term hospitals (odds ratio (OR)= 2.6, 95% confidence interval = 2.1-3.3, p \u3c 0.001) were also higher in cocaine cohort. Venous thromboembolism was observed to be linked with cocaine use (OR= 1.5, 95% confidence interval= 1.0-2.1, p \u3c 0.01) but less severely than vasculitis (OR= 3.0, 95% confidence interval= 1.6-5.8, p \u3c 0.001). Further prospective research is warranted in this direction to improve the outcomes for AIS and lessen the financial burden on the healthcare system of the United States

    A Collision Cone Approach for Control Barrier Functions

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    This work presents a unified approach for collision avoidance using Collision-Cone Control Barrier Functions (CBFs) in both ground (UGV) and aerial (UAV) unmanned vehicles. We propose a novel CBF formulation inspired by collision cones, to ensure safety by constraining the relative velocity between the vehicle and the obstacle to always point away from each other. The efficacy of this approach is demonstrated through simulations and hardware implementations on the TurtleBot, Stoch-Jeep, and Crazyflie 2.1 quadrotor robot, showcasing its effectiveness in avoiding collisions with dynamic obstacles in both ground and aerial settings. The real-time controller is developed using CBF Quadratic Programs (CBF-QPs). Comparative analysis with the state-of-the-art CBFs highlights the less conservative nature of the proposed approach. Overall, this research contributes to a novel control formation that can give a guarantee for collision avoidance in unmanned vehicles by modifying the control inputs from existing path-planning controllers.Comment: 13 pages, 16 pages. arXiv admin note: substantial text overlap with arXiv:2209.11524, arXiv:2303.15871, arXiv:2310.1083

    Robotic Offline RL from Internet Videos via Value-Function Pre-Training

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    Pre-training on Internet data has proven to be a key ingredient for broad generalization in many modern ML systems. What would it take to enable such capabilities in robotic reinforcement learning (RL)? Offline RL methods, which learn from datasets of robot experience, offer one way to leverage prior data into the robotic learning pipeline. However, these methods have a "type mismatch" with video data (such as Ego4D), the largest prior datasets available for robotics, since video offers observation-only experience without the action or reward annotations needed for RL methods. In this paper, we develop a system for leveraging large-scale human video datasets in robotic offline RL, based entirely on learning value functions via temporal-difference learning. We show that value learning on video datasets learns representations that are more conducive to downstream robotic offline RL than other approaches for learning from video data. Our system, called V-PTR, combines the benefits of pre-training on video data with robotic offline RL approaches that train on diverse robot data, resulting in value functions and policies for manipulation tasks that perform better, act robustly, and generalize broadly. On several manipulation tasks on a real WidowX robot, our framework produces policies that greatly improve over prior methods. Our video and additional details can be found at https://dibyaghosh.com/vptr/Comment: First three authors contributed equall

    Advances in Electromagnetic Therapy for Wound Healing

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    Understanding the molecular basis of wound healing and tissue regeneration continues to remain as one of the major challenges in modern medicine. There is absolute necessity to unveil the rather elusive mechanism with a special emphasis on the approaches to accelerate wound healing. Low frequency low intensity Pulsed electromagnetic therapy is evidenced to have a significant impact on wound repair and regeneration. It provides a non-invasive reparative technique to treat an injury. In vitro studies reported a significant effect of electromagnetic field on neovascularisation and angiogenesis. There are also many pieces of evidence which support its efficiency in reducing the duration of wound healing and improving the tensile strength of scars. Here, we compared the traditional stigma associated with pulsed electromagnetic fields and weighed them with its potential therapeutic effect on wound healing. Furthermore, we emphasized the need for more focused research to determine the therapeutic strategies and optimised parameters of pulsed electromagnetic field that can assure efficient wound healing and regeneration.

    Comparative review of international approaches to net-zero buildings:Knowledge-sharing initiative to develop design strategies for greenhouse gas emissions reduction

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    The concept of net-zero, climate-neutral buildings is attracting global attention, and it is widely recognised as a key solution for achieving climate neutrality targets in the construction sector. However, an increasing and confusing abundance of differing labels, definitions, and approaches is increasing worldwide. This article aims to chart the current progress of national net-zero building pathways and identify gaps and challenges that present a significant barrier to industry uptake and decarbonisation of the built environment worldwide. The national net-zero pathways include an analysis of building legislation, policy and voluntary frameworks in four selected countries, Norway, the United Kingdom, the United States and Singapore, which are all leading regional actors in the race to zero and achieving a climate-neutral construction sector. Firstly, the study provides an overview of each country-specific context and motivation related to climate change adaptation and mitigation in the construction sector. Secondly, a review of the essential features from market-leading net-zero definitions, methodologies, schemes, and tools describing specific building approaches is conducted in each investigated country. Finally, based on the selected net-zero building case studies, the article presents the most promising design strategies for both embodied and operational environmental impact reductions, considering each specific climatic and country context. The research results indicated that the system boundaries for embodied and operational indicators (energy or GHG emissions) presented in investigated net-zero frameworks vary significantly. Consequently, there is an urgent need for a harmonised and transparent standardisation to provide coherence through performed life cycle assessments of buildings. In terms of the design strategies for achieving net-zero ambition according to the investigated frameworks, the common approach is the integration of the passive and active design strategies for operational energy or GHG emission reduction. However, it is evident that in some net-zero building examples, the consideration of the embodied environmental impacts and potential reduction strategies is missing because of not being included and mandatory in the national net-zero framework. This work is built upon the current body of knowledge on existing net-zero building frameworks and already constructed buildings and provides practical indications for building policy development and environmental impact reduction strategies in future climate-neutral, net-zero building projects.</p
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