264 research outputs found

    Nature and causes of land degradation and desertification in Libya: Need for sustainable land management

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    In this article, the characteristics of desertification, causative factors and efforts to combat desertification in Libya are presented. Also, the need to mainstream sustainable land management into land use planning is highlighted which could provide a firm basis for future policy decisions to combat desertification. Libya is characterized by a desert type environment and more than 95% of the country is desert or semi-desert. The processes of desertification have been aggravated by human activities coupled with climatic conditions. This intensification of desertification is believed to affect regional as well as global climate. Currently, desertification is one of the main environmental issues in Libya affecting environment and its resources. Among others, overexploitation of natural resources, inappropriate land use planning, insufficient water resources etc. are the main factors escalating the process of desertification and deteriorating environmental quality. Mainstreaming sustainable land management into land use planning has been considered a viable solution to moderate the effects of desertification and rampant usages of natural resources. However, this requires quantifying the severity of desertification by means of identified causative factor. Development of indicators of desertification process by means of using time-series satellite data coupled with ancillary data need to be attempted to establish a monitoring system to manage desertification in more sensitive areas. Moreover, environmental and livelihood implications of increasing desertification need to be addressed in order to promote regional economic sustainable development.Key words: Desertification, human impacts, Libya, natural resources, sustainable development, remote sensing, monitoring

    High contrast imaging and thickness determination of graphene with in-column secondary electron microscopy

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    We report a new method for quantitative estimation of graphene layer thicknesses using high contrast imaging of graphene films on insulating substrates with a scanning electron microscope. By detecting the attenuation of secondary electrons emitted from the substrate with an in-column low-energy electron detector, we have achieved very high thickness-dependent contrast that allows quantitative estimation of thickness up to several graphene layers. The nanometer scale spatial resolution of the electron micrographs also allows a simple structural characterization scheme for graphene, which has been applied to identify faults, wrinkles, voids, and patches of multilayer growth in large-area chemical vapor deposited graphene. We have discussed the factors, such as differential surface charging and electron beam induced current, that affect the contrast of graphene images in detail.Comment: 5 pages, 4 figure

    Global hotspots in the present-day distribution of ancient animal and plant lineages

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    Intranasal Mice Model to Study the role of Bordetella pertussis antigens in Immunity

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    699-702Pertussis known as whooping cough is a highly contagious disease. Whole cell pertussis vaccine is the most economical and effective strategy for preventing and controlling pertussis. The efficacy of whole cell vaccine is ascertained most commonly by intracerebral challenge assay, but it does not reflect the true efficacy of vaccine as Pertussis essentially is a respiratory disease. Therefore, in order to mimic the natural infection, intranasal challenge model in mice was developed. In intranasal challenge assay mice were immunized with vaccine and challenged through intranasal route. Mice lungs were dissected and examined for bacterial count. The degree of count was related to efficacy of vaccine, higher count indicated low efficacy and low count pointed to better efficacy

    Disclination vortices in elastic media

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    The vortex-like solutions are studied in the framework of the gauge model of disclinations in elastic continuum. A complete set of model equations with disclination driven dislocations taken into account is considered. Within the linear approximation an exact solution for a low-angle wedge disclination is found to be independent from the coupling constants of the theory. As a result, no additional dimensional characteristics (like the core radius of the defect) are involved. The situation changes drastically for 2\pi vortices where two characteristic lengths, l_\phi and l_W, become of importance. The asymptotical behaviour of the solutions for both singular and nonsingular 2\pi vortices is studied. Forces between pairs of vortices are calculated.Comment: 13 pages, published versio

    Evaluation of the response rate of chemo-radiation and brachytherapy in patients with locally advanced carcinoma cervix in a tertiary care center

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    Background: Incidence and mortality estimates are used to measure the burden of cancer in a population and survival estimates are ideal for evaluating the outcome of cancer control activities. Survival studies evaluate the quality and quantity of life of a group of patients after diagnosing the disease. The patient survival after the diagnosis of cervical cancer is indirectly influenced by socio-economic factors. The present study was carried out with an aim to evaluate the success rate of chemo-radiation followed by brachytherapy to the patients of locally advanced carcinoma (Ca.) cervix in a tertiary care center.Methods: All cases were staged according to the International Federation of Gynaecologists and Oncologists (FIGO) staging system. To illustrate the observed survival of cancer patients Kaplan-Meier curve was plotted. All the patients, except one, completed chemo-radiation and were retrospectively analyzed for the presence of local residual disease, local recurrence, distant metastases, radiation reactions, disease-free survival, and overall survival.Results: There were 22 patients of Carcinoma cervix reported in the radiation oncology department in the year 2018 and 2019. The overall treatment time ranged from 30 days to 178 days, with a median of 63 days. All the patients had a complete response after the treatment. The median follow-up time for all the patients was 15 months. Three patients had a metastatic recurrence and one patient developed distant metastases as well as local recurrence. Overall survival rate was 100% while the disease-free survival rate was 81.82%.Conclusions: The response to chemo-radiation in the treatment of locally advanced Carcinoma cervix is comparable to historic data and is well tolerated

    Dislocation-Mediated Melting: The One-Component Plasma Limit

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    The melting parameter Γm\Gamma_m of a classical one-component plasma is estimated using a relation between melting temperature, density, shear modulus, and crystal coordination number that follows from our model of dislocation-mediated melting. We obtain Γm=172±35,\Gamma_m=172\pm 35, in good agreement with the results of numerous Monte-Carlo calculations.Comment: 8 pages, LaTe

    Quantum thermodynamics at critical points during melting and solidification processes

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    We systematically explore and show the existence of finite-temperature continuous quantum phase transition (CTQPT) at a critical point, namely, during solidification or melting such that the first-order thermal phase transition is a special case within CTQPT. Infact, CTQPT is related to chemical reaction where quantum fluctuation (due to wavefunction transformation) is caused by thermal energy and it can occur maximally for temperatures much higher than zero Kelvin. To extract the quantity related to CTQPT, we use the ionization energy theory and the energy-level spacing renormalization group method to derive the energy-level spacing entropy, renormalized Bose-Einstein distribution and the time-dependent specific heat capacity. This work unambiguously shows that the quantum phase transition applies for any finite temperatures.Comment: To be published in Indian Journal of Physics (Kolkata

    Dizajniranje, sinteza, kinetika hidrolize i farmakodinamski profili konjugata aceklofenaka s histidinom i alaninom

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    The gastrointestinal toxicity associated with aceclofenac can be reduced by condensing its carboxylic acid group with methyl esters of amino acids like histidine and alanine to give amide linkage by the Schotten-Baumann method. Physicochemical characterization of the conjugates was carried out by various analytical and spectral methods. The synthesized conjugates were also subjected to in vitro hydrolysis in simulated gastric fluid (SGF) at pH 1.2, simulated intestinal fluid (SIF) at pH 7.4 and SIF + 80 % human plasma at pH 7.4. The release of free aceclofenac from histidine and alanine conjugated aceclofenac showed negligible hydrolysis in SGF compared to SIF. This indicated that the conjugates do not break in stomach, but release aceclofenac in SIF. Both synthesized conjugates showed excellent pharmacological response and encouraging hydrolysis rate in SIF and SIF + 80 % human plasma. Marked reduction of the ulcer index and comparable increase in analgesic and anti-inflammatory activities were obtained in both cases compared to aceclofenac alone. These findings suggest that the conjugates are better in action compared to the parent drug and have fewer gastrointestinal side-effects.Gastrointestinalna toksičnost aceklofenaka može se umanjiti kondenzacijom karboksilne skupine aceklofenaka s metilnim esterima aminokiselina poput histidina i alanina, pri čemu se stvaraju nove amidne veze po Schotten-Baumannovoj metodi. Fizikokemijska karakterizacija konjugata provedena je različitim analitičkim i spektralnim metodama. Nadalje, praćena je hidroliza sintetiziranih konjugata in vitro u simuliranoj gastričnoj tekućini (SGF) pri pH 1,2, simuliranoj intestinalnoj tekućini (SIF) pri pH 7,4 i simuliranoj intestinalnoj tekućini s 80 % humane plazme pri pH 7,4. Oslobađanje aceklofenaka iz konjugata s histidinom, odnosno alaninom, bilo je zanemarivo u SGF-u, u odnosu na oslobađanje u SIF-u. To ukazuje da su konjugati stabilni u želucu, dok se u SIF-u iz njih oslobađa aceklofenak. Oba konjugata daju izvrstan farmakološki odgovor i zadovoljavajući stupanj hidrolize u SIF-u i smjesi SIF-a i humane plazme. Oba konjugata pokazala su značajno smanjenu ulcerogenost i pojačano analgetsko i protuupalno djelovanje u odnosu na aceklofenak. Rezultati ukazuju na prednost konjugata u odnosu na samu ljekovitu tvar
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