144 research outputs found
Application of predictive degree day model for field development of sandfly vectors of visceral leishmaniasis in northwest of Iran
Background & objectives: Temperature plays a significant role in insect’s development where arise in temperature, accelerates the insect’s metabolic rates, increases egg production and makesblood feeding more frequent. It also shortens the time period required for the development ofpathogens within insects. Visceral leishmaniasis (VL) is one of the most important vector-bornediseases transmitted by different sandfly species. In this study, a phenological model was used toestimate the number of generations, peak activity and temporal variability of sandflies in the mainVL foci in northwest Iran.Methods: Development requirements of different life stages of a Phlebotomus papatasi laboratorycolony were measured and were subjected to the formula for calculation of accumulated degree day(ADD) for field sandflies using the online soft (UC IPM), using horizontal cut-off method andsingle triangle model. Sandflies population dynamics was monitored in the field during the seasonalactivity in the region and its association with the ADD was tested using SAS software.Results: Populations of sandflies accommodated well with the amount of accumulated degree days(ADD) in the region. During the seasonal activity, a total of 639 ADD were produced which wasenough to support one complete life cycle and growth of the next generation up to late larvalinstar. Larvae of the second generation hibernate through winter and the first adult populationappears in the mid to late June of the next year when they receive at least 182 ADD from thebeginning of the spring. The highest population density of sandflies was observed in early August,followed by a rapid decrease in early September, with the adult population disappearing completelyin late September. This is the first degree day model related to sandflies in the most important VLfoci of Iran.Interpretation & conclusion: Further studies in various regions with variable climate arerecommended in order to better estimate and understand the development time, population dynamicsand activities of the vectors which in turn could be used in proper implementation of effectivevector control programmes
Influence of core stability exercise on lumbar vertebral instability in patients presented with chronic low back pain: A randomized clinical trial
Background: Excessive lumbar vertebrae translation and rotation in sagittal plane has been attributed as an associated factor of lumbar segmental instability (LSI) and low back pain (LBP). Reduction of these abnormalities improves back pain. The aim of this study was to investigate the effect of core stability exercise on the translation and rotation of lumbar vertebrae in sagittal plane in patients with nonspecific chronic LBP (NSCLBP). Methods: In this randomized clinical trial, 30 patients with NSCLBP due to LSI were included. The participants were randomly divided into two groups of treatment and control. The treatment group received general exercises plus core stability exercise for 8 weeks whereas; the control group received only general exercises. The magnitude of translation (mm) and rotation (deg) of lumbar vertebrae in the sagittal plane was determined by radiography in flexion and extension at baseline and after intervention. The primary outcome measures were to determine the mean changes from baseline in translation and rotation of the lumbar vertebrae in the sagittal plane after 8 weeks of intervention in each group. The secondary outcome was to compare the two groups in regard to translation and rotation of the lumbar vertebrae at the end of the study period. Data were analyzed using paired t-test and independent t-test. Results: Thirty patients aged 18-40 years old with clinical diagnosis of NSCLBP entered the study. Compared with baseline values, mean value of translation and rotation of the lumbar vertebra reduced significantly in both groups (P<0.05), except L3 translation in the control group. At the endpoint, mean translation value of L4 (P=0.04) and L5 (P=0.001) and rotation of the L5 (P=0.01) in the treatment group was significantly lower than the control group. Conclusion: These findings indicate that in patients presented with NSCLBP due to lumbar segmental instability, core stability exercises plus general exercises are more efficient than general exercises alone in the improvement of excessive lumbar vertebrae translation and rotation
Mechanical properties of dense mycelium-bound composites under accelerated tropical weathering conditions
Mycelium, as the root of fungi, is composed of filamentous strands of fine hyphae that bind discrete substrate particles into a block material. With advanced processing, dense mycelium-bound composites (DMCs) resembling commercial particleboards can be formed. However, their mechanical properties and performance under the working conditions of particleboards are unknown. Here, we show how weathering conditions affect the DMC stress and elastic modulus. DMC was made using Ganoderma lucidum mycelium grown on a substrate of sawdust and empty fruit bunch. The DMC was then subjected to weathering under tropical conditions over 35 days and tested under flexural, tensile, and compressive loading with reference to international standards. After exposure to specified weathering conditions, the maximum stress in flexure, tension, and compression decreased substantially. The addition of a protective coating improved the resistance of DMC to weathering conditions; however, the difference between coated and uncoated samples was only found to be statistically significant in tensile strength
Development of an extrudable paste to build mycelium-bound composites
Mycelium-bound composites are promising materials for sustainable packaging, insulation, fashion, and architecture. However, moulding is the main fabrication process explored to date, strongly limiting the ability to design the complex shapes that could widen the range of applications. Extrusion is a facile and low energy-cost process that has not yet been explored for mycelium-bound composites with design freedom and structural properties. In this study, we combine cheap, easily and commonly available agricultural waste materials, bamboo microfibres, chitosan, and mycelium from Ganodermalucidum, to establish a composite mixture that is workable, extrudable and buildable. We study the impact of bamboo fibre size, chitosan concentration, pH and weight ratio of bamboo to chitosan to determine the optimum growth condition for the mycelium as well as high mechanical stiffness. The resulting materials have thus low energy costs, are sustainable and can be shaped easily. The developed composition is promising to further explore the use of mycelium-bound materials for structural applications using agricultural waste
Comparison of Falls and its Determinants in the Elderly with and without Knee Osteoarthritis
Background and Objective: The growth of aging reveals the importance of paying attention to the health needs of the elderly. According to some studies, falls and its consequences are more common in the individuals with knee osteoarthritis (KOA) than those without KOA, but due to lack of evidence, its related factors are still unknown. Thus, the aim of this study was to compare the falls and its determinants in the elderly with and without KOA.
Methods: In this case-control study, 700 older adults in two groups of elderly with and without KOA were compared in terms of falls and some variables including KOA, sex, age, body mass index, living status, quadriceps femoris muscle strength, hand muscles strength, balance, number of comorbidities, number of drugs used, walking duration, physical activity and frailty. KOA was diagnosed based on The American College of Rheumatology (ACR) criteria.
Findings: In this study, falls were 1.90 times higher in the elderly with KOA than elderly without KOA. Although all variables were significantly different in case and control groups, only female gender (p=0.035) and KOA (p=0.012) were significantly associated with falls.
Conclusion: These findings suggest that variables in combination may increase the risk of falls in the elderly with KOA, while each of them alone may not be associated with falls
Assessing the Responsiveness of the Persian Version of the Western Ontario Meniscal Evaluation Tool in Patients with Meniscus Injuries
Background and Objective: Responsiveness is one of the important properties of health-related questionnaires in demonstrating the changes in a patient's clinical conditions before and after therapy. The present study was carried out with the aim of assessing the responsiveness of the Western Ontario Meniscal Evaluation Tool (WOMET) and determining its minimal clinically important difference in patients undergoing physical therapy interventions after meniscus injuries.
Methods: This cross-sectional methodological study was performed on 100 patients aged 18-70 years with meniscus injuries who underwent physical therapy interventions. Patients completed WOMET and Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaires in the first and tenth sessions. The minimum score obtained from the WOMET questionnaire was zero and the maximum was 1600, and the minimum score obtained from the KOOS questionnaire was zero and the maximum was 168. Internal and external responsiveness were the primary outcomes, and effect size tests, ROC curves, and correlation coefficients were used to examine them. The relationship between the WOMET and KOOS questionnaires were considered as secondary outcomes, which were evaluated by calculating the correlation coefficient.
Findings: The results of internal responsiveness showed that the standardized response mean for the entire WOMET questionnaire was 0.11 (insignificant) and Cohen's d score for the entire WOMET questionnaire was -1.586 (large). The difference in the mean internal responsiveness between recovered (20%) and unrecovered (80%) patients reached a significant level (p<0.001). This questionnaire had an acceptable external responsiveness; the area under the curve of the ROC curve was greater and equal to 0.7 and the optimal cut-off point was 20.031 (p<0.001). The Pearson correlation coefficient between WOMET and KOOS questionnaires (except the emotions subscale) was moderate to large (0.5-0.8) with p<0.001.
Conclusion: The findings of the study showed that the Persian version of the WOMET questionnaire has a high level of responsiveness and is a suitable tool for evaluating the quality of life among patients suffering from meniscus injury
Comparison of three malignancy risk indices and CA-125 in the preoperative evaluation of patients with pelvic masses
A historical overview of the classification, evolution, and dispersion of Leishmania parasites and sandflies
Background The aim of this study is to describe the major evolutionary historical events among Leishmania, sandflies, and the associated animal reservoirs in detail, in accordance with the geographical evolution of the Earth, which has not been previously discussed on a large scale. Methodology and Principal Findings Leishmania and sandfly classification has always been a controversial matter, and the increasing number of species currently described further complicates this issue. Despite several hypotheses on the origin, evolution, and distribution of Leishmania and sandflies in the Old and New World, no consistent agreement exists regarding dissemination of the actors that play roles in leishmaniasis. For this purpose, we present here three centuries of research on sandflies and Leishmania descriptions, as well as a complete description of Leishmania and sandfly fossils and the emergence date of each Leishmania and sandfly group during different geographical periods, from 550 million years ago until now. We discuss critically the different approaches that were used for Leishmana and sandfly classification and their synonymies, proposing an updated classification for each species of Leishmania and sandfly. We update information on the current distribution and dispersion of different species of Leishmania (53), sandflies (more than 800 at genus or subgenus level), and animal reservoirs in each of the following geographical ecozones: Palearctic, Nearctic, Neotropic, Afrotropical, Oriental, Malagasy, and Australian. We propose an updated list of the potential and proven sandfly vectors for each Leishmania species in the Old and New World. Finally, we address a classical question about digenetic Leishmania evolution: which was the first host, a vertebrate or an invertebrate? Conclusions and Significance We propose an updated view of events that have played important roles in the geographical dispersion of sandflies, in relation to both the Leishmania species they transmit and the animal reservoirs of the parasites
Effect of Leishmania spp infection on the survival, life expectancy, fecundity and fertility of Lutzomyia longipalpis s.l. and Lutzomyia pseudolongipalpis
Hydrogen Storage Materials for Mobile and Stationary Applications: Current State of the Art
One of the limitations to the widespread use of hydrogen as an energy carrier is its storage in a safe and compact form. Herein, recent developments in effective high-capacity hydrogen storage materials are reviewed, with a special emphasis on light compounds, including those based on organic porous structures, boron, nitrogen, and aluminum. These elements and their related compounds hold the promise of high, reversible, and practical hydrogen storage capacity for mobile applications, including vehicles and portable power equipment, but also for the large scale and distributed storage of energy for stationary applications. Current understanding of the fundamental principles that govern the interaction of hydrogen with these light compounds is summarized, as well as basic strategies to meet practical targets of hydrogen uptake and release. The limitation of these strategies and current understanding is also discussed and new directions proposed
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