Search results for: landslide susceptibility

Authors: Krishna Raj Regmi

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A “Climate change adaptation and disaster risk management for sustainable agriculture” project was implemented in Nepal, a Himalayan country during 2008 to 2013 sponsored jointly by Food and Agriculture Organization (FAO) and United Nations Development Programme (UNDP), Nepal. The paper is based on the results and findings of this joint pilot project. The climate change events such as increased intensity of erratic rains in short spells, trend of prolonged drought, gradual rise in temperature in the higher elevations and occurrence of cold and hot waves in Terai (lower plains) has led to flash floods, massive erosion in the hills particularly in Churia range and drying of water sources. These recurring natural and climate-induced disasters are causing heavy damages through sedimentation and inundation of agricultural lands, crops, livestock, infrastructures and rural settlements in the downstream plains and thus reducing agriculture productivity and food security in the country. About 65% of the cultivated land in Nepal is rainfed with drought-prone characteristics and stabilization of agricultural production and productivity in these tracts will be possible through adoption of rainfed and drought-tolerant technologies as well as efficient soil-water management by the local communities. The adaptation and mitigation technologies and options identified by the project for soil erosion, flash floods and landslide control are on-farm watershed management, sloping land agriculture technologies (SALT), agro-forestry practices, agri-silvi-pastoral management, hedge-row contour planting, bio-engineering along slopes and river banks, plantation of multi-purpose trees and management of degraded waste land including sandy river-bed flood plains. The stress tolerant technologies with respect to drought, floods and temperature stress for efficient utilization of nutrient, soil, water and other resources for increased productivity are adoption of stress tolerant crop varieties and breeds of animals, indigenous proven technologies, mixed and inter-cropping systems, system of rice/wheat intensification (SRI), direct rice seeding, double transplanting of rice, off-season vegetable production and regular management of nurseries, orchards and animal sheds. The alternate energy use options and resource conservation practices for use by local communities are installation of bio-gas plants and clean stoves (Chulla range) for mitigation of green house gas (GHG) emissions, use of organic manures and bio-pesticides, jatropha cultivation, green manuring in rice fields and minimum/zero tillage practices for marshy lands. The efficient water management practices for increasing productivity of crops and livestock are use of micro-irrigation practices, construction of water conservation and water harvesting ponds, use of overhead water tanks and Thai jars for rain water harvesting and rehabilitation of on-farm irrigation systems. Initiation of some works on community-based early warning system, strengthening of met stations and disaster database management has made genuine efforts in providing disaster-tailored early warning, meteorological and insurance services to the local communities. Contingent planning is recommended to develop coping strategies and capacities of local communities to adopt necessary changes in the cropping patterns and practices in relation to adverse climatic and disaster risk conditions. At the end, adoption of awareness raising and capacity development activities (technical and institutional) and networking on climate-induced disaster and risks through training, visits and knowledge sharing workshops, dissemination of technical know-how and technologies, conduct of farmers' field schools, development of extension materials and their displays are being promoted. However, there is still need of strong coordination and linkage between agriculture, environment, forestry, meteorology, irrigation, climate-induced pro-active disaster preparedness and research at the ministry, department and district level for up-scaling, implementation and institutionalization of climate change and disaster risk management activities and adaptation mitigation options in agriculture for sustainable livelihoods of the communities.

Keywords: climate change adaptation, disaster risk management, soil-water management practices, sustainable agriculture

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Authors: Mohammadjavad Sotoudeheian, Soroush Nematollahi

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Crohn’s disease (CD) is a chronic gastrointestinal segment inflammation encompassing immune dysregulation in a genetically susceptible individual in response to the environmental triggers and interaction between the microbiome and immune system. Uncontrolled inflammation leads to long-term complications, including fibrotic strictures and enteric fistulae. Increased production of Th1 and Th17-cell cytokines and defects in T-regulatory cells have been associated with CD. Th17-cells are essential for protection against extracellular pathogens, but their atypical activity can cause autoimmunity. Intrinsic defects in the control of programmed cell death in the mucosal T-cell compartment are strongly implicated in the pathogenesis of CD. The apoptosis defect in mucosal T-cells in CD has been endorsed as an imbalance of the Bcl-2 and the Bax. The immune system encounters foreign antigens through microbial colonization of mucosal surfaces or infections. In addition, FOSL downregulated IL-26 expression, a cytokine that marks inflammatory Th17-populations in patients suffering from CD. Furthermore, the expression of IL-23 is associated with the transcription factor primary leucine zipper transcription factor ATF-like (Batf). Batf-deficiency demonstrated the crucial role of Batf in colitis development. Batf and IL-23 mediate their effects by inducing IL-6 production. Strong association of IL-23R, Stat3, and Stat4 with IBD susceptibility point to a critical involvement of T-cells. IL-23R levels in transfer fistula were dependent on the AP-1 transcription factor JunB that additionally controlled levels of RORγt by facilitating DNA binding of Batf. T lymphocytes lacking JunB failed to induce IL-23- and Th17-mediated experimental colitis highlighting the relevance of JunB for the IL-23/ Th17 pathway. The absence of T-bet causes unrestrained Th17-cell differentiation. T-cells are central parts of immune-mediated colon fistula. Especially Th17-cells were highly prevalent in inflamed IBD tissues, as RORγt is effective in preventing colitis. Intraepithelial lymphocytes (IEL) contain unique T-cell subsets, including cells expressing RORγt. Increased activated Th17 and decreased T-regulatory cells in inflamed intestinal tissues had been seen. T-cells differentiate in response to many cytokines, including IL-1β, IL-6, IL-23, and TGF-β, into Th17-cells, a process which is critically dependent on the Batf. IL-23 promotes Th17-cell in the colon. Batf manages the generation of IL-23 induced IL-23R+ Th17-cells. Batf is necessary for TGF-β/IL-6-induced Th17-polarization. Batf-expressing T-cells are the core of T-cell-mediated colitis. The human-specific parts of three AP-1 transcription factors, FOSL1, FOSL2, and BATF, are essential during the early stages of Th17 differentiation. BATF supports the Th17 lineage. FOSL1, FOSL2, and BATF make possession of regulatory loci of genes in the Th17 lineage cascade. The AP1 transcription factor Batf is identified to control intestinal inflammation and seems to regulate pathways within lymphocytes, which could theoretically control the expression of several genes. It shows central regulatory properties over Th17-cell development and is intensely upregulated within IBD-affected tissues. Here, we demonstrated that targeting Batf in IBD appears as a therapeutic approach that reduces colitogenic T-cell activities during fistula formation while aiming to affect inflammation in the gut epithelial cells.

Keywords: immune system, Crohn’s Disease, BATF, T helper cells, Bcl, interleukin, FOSL

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Authors: Marian Mihalik, Kornel Csach, Martin Kovalik, Matúš Mihalik, Martina Kubovčíková, Maria Zentková, Martin Vavra, Vladimír Girman, Jaroslav Briančin, Marija Perovic, Marija Boškovic, Magdalena Fitta, Robert Pelka

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Current nanomaterials for use in biomedicine are based mainly on iron oxides and on present knowledge on magnetic nanostructures. Manganites can represent another material which can be used optionally. Manganites and their unique electronic properties have been extensively studied in the last decades not only due to fundamental interest but to possible applications of colossal magnetoresistance, magnetocaloric effect, and ferroelectric properties. It was found that the oxygen-reduction reaction on perovskite oxide is intimately connected with metal ion e.g., orbital occupation. The effect of oxygen deviation from the stoichiometric composition on crystal structure was studied very carefully by many authors on LaMnO₃. Depending on oxygen content, the crystal structure changes from orthorhombic one to rhombohedric for oxygen content 3.1. In the case of hole-doped manganites, the change from the orthorhombic crystal structure, which is typical for La1-xCaxMnO3 based manganites, to the rhombohedric crystal structure (La1-xMxMnO₃ where M = K, Ag, and Sr based materials) results in an enormous increase of the Curie temperature. In our paper, we study the effect of oxygen content on crystal structure, thermal, and magnetic properties (including magnetocaloric effect) of La1-xAgxMnO₃nano particle system. The content of oxygen in samples was tuned by heat treatment in different thermal regimes and in various environment (air, oxygen, argon). Water nanosuspensions based on La0.80Ag0.15MnO₃ magnetic particles with the Curie temperature of about 43oC were prepared by two different approaches. First, by using a laboratory circulation mill for milling of powder in the presence of sodium dodecyl sulphate (SDS) and subsequent centrifugation. Second nanosuspension was prepared using an agate bowl, etching in citric acid and HNO3, ultrasound homogeniser, centrifugation, and dextran 40 kDA or 15 kDA as surfactant. Electrostatic stabilisation obtained by the first approach did not offer long term kinetic and aggregation colloidal stability and was unable to compensate for attractive forces between particles under a magnetic field. By the second approach, we prepared suspension oversaturated by dextran 40 kDA for steric stabilisation, with evidence of the presence of superparamagnetic behaviour. Low concentration of nanoparticles and not ideal coverage of nanoparticles impacting the stability of ferrofluids was the disadvantage of this approach. Strong steric stabilisation was observable at alcaic conditions under pH = ~10. Application of dextran 15 kDA leads to relatively stable ferrofluid with pH around physiological conditions, but desegregation of powder by HNO₃ was not effective enough, and the average size of fragments was to large of about 150 nm, and we did not see any signature of superparamagnetic behaviour. The prepared ferrofluids were characterised by scanning and transition microscope method, thermogravimetry, magnetization, and AC susceptibility measurements. Specific Absorption Rate measurements were undertaken on powder as well on ferrofluids in order to estimate the potential application of La₀.₈₀Ag₀.₁₅MnO₃ magnetic particles based ferrofluid for hyperthermia. Our complex study contains an investigation of biocompatibility and potential biohazard of this material.

Keywords: manganites, magnetic nanoparticles, oxygen content, magnetic phase transition, magnetocaloric effect, ferrofluid, hyperthermia

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Authors: Kakali Roy, Sahana P. Raju, Subhra Dhar, Sandipan Dhar

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Introduction: Xeroderma pigmentosa (XP) is a rare inherited (autosomal recessive) disease resulting from impairment in DNA repair that involves recognition and repair of ultraviolet radiation (UVR) induced DNA damage in the nucleotide excision repair pathway. Which results in increased photosensitivity, UVR induced damage to skin and eye, increased susceptibility of skin and ocular cancer, and progressive neurodegeneration in some patients. XP is present worldwide, with higher incidence in areas having frequent consanguinity. Being extremely rare, there is limited literature on XP and associated complications. Here, the clinico-pathological experience (spectrum of clinical presentation, histopathological findings of malignant skin lesions, and progression) of managing 8 cases of XP is presented. Methodology: A retrospective study was conducted in a pediatric tertiary care hospital in eastern India during a ten-year period from 2013 to 2022. A clinical diagnosis was made based on severe sun burn or premature photo-aging and/or onset of cutaneous malignancies at early age (1st decade) in background of consanguinity and autosomal recessive inheritance pattern in family. Results: The mean age of presentation was 1.2 years (range of 7month-3years), while three children presented during their infancy. Male to female ratio was 5:3, and all were born of consanguineous marriage. They presented with dermatological manifestations (100%) followed by ophthalmic (75%) and/or neurological symptoms (25%). Patients had normal skin at birth but soon developed extreme sensitivity to UVR in the form of exaggerated sun tanning, burning, and blistering on minimal sun exposure, followed by abnormal skin pigmentation like freckles and lentiginosis. Subsequently, over time there was progressive xerosis, atrophy, wrinkling, and poikiloderma. Six patients had varied degree of ocular involvement, while three of them had severe manifestation, including madarosis, tylosis, ectropion, Lagopthalmos, Pthysis bulbi, clouding and scarring of the cornea with complete or partial loss of vision, and ophthalmic malignancies. 50% (n=4) cases had skin and ocular pre-malignant (actinic keratosis) and malignant lesions, including melanoma and non melanoma skin cancer (NMSC) like squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) in their early childhood. One patient had simultaneous occurrence of multiple malignancies together (SCC, BCC, and melanoma). Subnormal intelligence was noticed as neurological feature, and none had sensory neural hearing loss, microcephaly, neuroregression, or neurdeficit. All the patients had been being managed by a multidisciplinary team of pediatricians, dermatologists, ophthalmologists, neurologists and psychiatrists. Conclusion: Although till date there is no complete cure for XP and the disease is ultimately fatal. But increased awareness, early diagnosis followed by persistent vigorous protection from UVR, and regular screening for early detection of malignancies along with psychological support can drastically improve patients’ quality of life and life expectancy. Further research is required on formulating optimal management of XP, specifically the role and possibilities of gene therapy in XP.

Keywords: childhood malignancies, dermato-pathological findings, eastern India, Xeroderma pigmentosa

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Authors: Achraf Al Faraj, Asma Sultana Shaik, Baraa Al Sayed

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Specific and effective targeting of drug delivery systems (DDS) to cancerous sites remains a major challenge for a better diagnostic and therapy. Recently, SWCNTs with their unique physicochemical properties and the ability to cross the cell membrane show promising in the biomedical field. The purpose of this study was first to develop a biocompatible iron oxide tagged SWCNTs as diagnostic nanoprobes to allow their noninvasive detection using MRI and their preferential targeting in a breast cancer murine model by placing an optimized flexible magnet over the tumor site. Magnetic targeting was associated to specific antibody-conjugated SWCNTs active targeting. The therapeutic efficacy of doxorubicin-conjugated SWCNTs was assessed, and the superiority of diffusion-weighted (DW-) MRI as sensitive imaging biomarker was investigated. Short Polyvinylpyrrolidone (PVP) stabilized water soluble SWCNTs were first developed, tagged with iron oxide nanoparticles and conjugated with Endoglin/CD105 monoclonal antibodies. They were then conjugated with doxorubicin drugs. SWCNTs conjugates were extensively characterized using TEM, UV-Vis spectrophotometer, dynamic light scattering (DLS) zeta potential analysis and electron spin resonance (ESR) spectroscopy. Their MR relaxivities (i.e. r1 and r2*) were measured at 4.7T and their iron content and metal impurities quantified using ICP-MS. SWCNTs biocompatibility and drug efficacy were then evaluated both in vitro and in vivo using a set of immunological assays. Luciferase enhanced bioluminescence 4T1 mouse mammary tumor cells (4T1-Luc2) were injected into the right inguinal mammary fat pad of Balb/c mice. Tumor bearing mice received either free doxorubicin (DOX) drug or SWCNTs with or without either DOX or iron oxide nanoparticles. A multi-pole 10x10mm high-energy flexible magnet was maintained over the tumor site during 2 hours post-injections and their properties and polarity were optimized to allow enhanced magnetic targeting of SWCNTs toward the primary tumor site. Tumor volume was quantified during the follow-up investigation study using a fast spin echo MRI sequence. In order to detect the homing of SWCNTs to the main tumor site, susceptibility-weighted multi-gradient echo (MGE) sequence was used to generate T2* maps. Apparent diffusion coefficient (ADC) measurements were also performed as a sensitive imaging biomarker providing early and better assessment of disease treatment. At several times post-SWCNT injection, histological analysis were performed on tumor extracts and iron-loaded SWCNT were quantified using ICP-MS in tumor sites, liver, spleen, kidneys, and lung. The optimized multi-poles magnet revealed an enhanced targeting of magnetic SWCNTs to the primary tumor site, which was found to be much higher than the active targeting achieved using antibody-conjugated SWCNTs. Iron-loading allowed their sensitive noninvasive tracking after intravenous administration using MRI. The active targeting of doxorubicin through magnetic antibody-conjugated SWCNTs nanoprobes was found to considerably decrease the primary tumor site and may have inhibited the development of metastasis in the tumor-bearing mice lung. ADC measurements in DW-MRI were found to significantly increase in a time-dependent manner after the injection of DOX-conjugated SWCNTs complexes.

Keywords: single-walled carbon nanotubes, nanomedicine, magnetic resonance imaging, cancer diagnosis and therapy

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Authors: Taikchan Lildar, Ayesha Samad, Suraj Sookhu

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Atrial fibrillation with rapid ventricular response results in the loss of atrial kick and shortened ventricular filling time, which often leads to decompensated heart failure. Pharmacologic rhythm control is the treatment of choice, and patients frequently benefit from the restoration of sinus rhythm. When pharmacologic treatment is unsuccessful or a patient declines hemodynamically, direct cardioversion is the treatment of choice. Torsades de pointes or “twisting of the points'' in French, is a rare but under-appreciated risk of cardioversion therapy and accounts for a significant number of sudden cardiac death each year. A 61-year-old female with no significant past medical history presented to the Emergency Department with worsening dyspnea. An electrocardiogram showed atrial fibrillation with rapid ventricular response, and a chest X-ray was significant for bilateral pulmonary vascular congestion. Full-dose anticoagulation and diuresis were initiated with moderate improvement in symptoms. A transthoracic echocardiogram revealed biventricular systolic dysfunction with a left ventricular ejection fraction of 30%. After consultation with an electrophysiologist, the consensus was to proceed with the restoration of sinus rhythm, which would likely improve the patient’s heart failure symptoms and possibly the ejection fraction. A transesophageal echocardiogram was negative for left atrial appendage thrombus; the patient was treated with a loading dose of amiodarone and underwent successful direct current cardioversion with 200 Joules. The patient was placed on telemetry monitoring for 24 hours and was noted to have frequent premature ventricular contractions with subsequent degeneration to torsades de pointes. The patient was found unresponsive and pulseless; cardiopulmonary resuscitation was initiated with cardioversion, and return of spontaneous circulation was achieved after four minutes to normal sinus rhythm. Post-cardiac arrest electrocardiogram showed sinus bradycardia with heart-rate corrected QT interval of 592 milliseconds. The patient continued to have frequent premature ventricular contractions and required two additional cardioversions to achieve a return of spontaneous circulation with intravenous magnesium and lidocaine. An automatic implantable cardioverter-defibrillator was subsequently implanted for secondary prevention of sudden cardiac death. The backup pacing rate of the automatic implantable cardioverter-defibrillator was set higher than usual in an attempt to prevent premature ventricular contractions-induced torsades de pointes. The patient did not have any further ventricular arrhythmias after implantation of the automatic implantable cardioverter-defibrillator. Overdrive pacing is a method utilized to treat premature ventricular contractions-induced torsades de pointes by preventing a patient’s susceptibility to R on T-wave-induced ventricular arrhythmias. Pacing at a rate of 90 beats per minute succeeded in controlling the arrhythmia without the need for traumatic cardiac defibrillation. In our patient, conversion of atrial fibrillation with rapid ventricular response to normal sinus rhythm resulted in a slower heart rate and an increased probability of premature ventricular contraction occurring on the T-wave and ensuing ventricular arrhythmia. This case highlights direct current cardioversion for atrial fibrillation with rapid ventricular response resulting in persistent ventricular arrhythmia requiring an automatic implantable cardioverter-defibrillator placement with overdrive pacing to prevent a recurrence.

Keywords: refractory atrial fibrillation, atrial fibrillation, overdrive pacing, torsades de pointes

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Authors: Jayanwita Sarkar, Usha Chakraborty, Bishwanath Chakraborty

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Plants are constantly interacting with various abiotic and biotic stresses. In changing climate scenario plants are continuously modifying physiological processes to adapt to changing environmental conditions which profoundly affect plant-pathogen interactions. Spot blotch in wheat is a fast-rising disease in the warmer plains of South Asia where the rise in minimum average temperature over most of the year already affecting wheat production. Hence, the study was undertaken to explore the role of elevated temperature in spot blotch disease development and modulation of antioxidative responses by plant growth promoting rhizobacteria (PGPR) for biocontrol of spot blotch at high temperature. Elevated temperature significantly increases the susceptibility of wheat plants to spot blotch causing pathogen Bipolaris sorokiniana. Two PGPR Bacillus safensis (W10) and Ochrobactrum pseudogrignonense (IP8) isolated from wheat (Triticum aestivum L.) and blady grass (Imperata cylindrical L.) rhizophere respectively, showing in vitro antagonistic activity against Bipolaris sorokiniana were tested for growth promotion and induction of resistance against spot blotch in wheat. GC-MS analysis showed that Bacillus safensis (W10) and Ochrobactrum pseudogrignonense (IP8) produced antifungal and antimicrobial compounds in culture. Seed priming with these two bacteria significantly increase growth, modulate antioxidative signaling and induce resistance and eventually reduce disease incidence in wheat plants at optimum as well as elevated temperature which was further confirmed by indirect immunofluorescence assay using polyclonal antibody raised against Bipolaris sorokiniana. Application of the PGPR led to enhancement in activities of plant defense enzymes- phenylalanine ammonia lyase, peroxidase, chitinase and β-1,3 glucanase in infected leaves. Immunolocalization of chitinase and β-1,3 glucanase in PGPR primed and pathogen inoculated leaf tissue was further confirmed by transmission electron microscopy using PAb of chitinase, β-1,3 glucanase and gold labelled conjugates. Activity of ascorbate-glutathione redox cycle related enzymes such as ascorbate peroxidase, superoxide dismutase and glutathione reductase along with antioxidants such as carotenoids, glutathione and ascorbate and osmolytes like proline and glycine betain accumulation were also increased during disease development in PGPR primed plant in comparison to unprimed plants at high temperature. Real-time PCR analysis revealed enhanced expression of defense genes- chalcone synthase and phenyl alanineammonia lyase. Over expression of heat shock proteins like HSP 70, small HSP 26.3 and heat shock factor HsfA3 in PGPR primed plants effectively protect plants against spot blotch infection at elevated temperature as compared with control plants. Our results revealed dynamic biochemical cross talk between elevated temperature and spot blotch disease development and furthermore highlight PGPR mediated array of antioxidative and molecular alterations responsible for induction of resistance against spot blotch disease at elevated temperature which seems to be associated with up-regulation of defense genes, heat shock proteins and heat shock factors, less ROS production, membrane damage, increased expression of redox enzymes and accumulation of osmolytes and antioxidants.

Keywords: antioxidative enzymes, defense enzymes, elevated temperature, heat shock proteins, PGPR, Real-Time PCR, spot blotch, wheat

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