225 research outputs found
Traditional Practices for Sustainable Rangeland and Natural Resources Management: A Case Study of the Barzok Region, Iran
Livestock husbandry ranks second in importance the agricultural economy of Iran and also underpins the livelihood of many nomadic and sedentary peoples (Farhadi 2001). At the same time many rural locations such as the Bazok district have wide appeal to tourists because of cultural and natural features. This means local Iranian villagers must manage the grassland resources in a sustainable way according to geographical and climatic conditions. In general, utilization systems developed by local villages endeavour to combine social, cultural, economic and technical factors in such a way as to provide an optimal output of agricultural and eco-services (Papeli and Khanyeki 2001). The aim of this study was assess the role of traditional practices to sustain their grassland resources
Filogenetska analiza gena za hemaglutinin podtipa H9N2 virusa influence ptica izdvojenih iz tovnih pilića u Iranu.
In the present study, the genetic variations were examined of hemagglutinin genes of 4 recent H9N2 subtype avian influenza viruses isolated in the Tehran province of Iran. These hemagglutinin genes were amplified and sequenced in order to compare these viruses with the previous isolates from Iran and some other countries from all over the world. The full length hemagglutinin genes of 112 H9N2 avian influenza strains isolated from chickens, and also migratory birds from all over the world, including 68 strains isolated in Iran during 1998-2012, were genetically analyzed. The amino acids in the hemagglutinin cleavage site of the all 4 recent isolates possessed a PAKSSR/GL motif, which is a different motif when compared with the predominant PARSSR/GL motif in the hemagglutinin of the Iranian H9N2 strains isolated before 2010. All 4 recent isolates possessed histidine, alanin, leucine and isoleucine at positions 183, 190, 226 and 227 respectively, which are the key residues in receptor-binding sites. Genetic and phylogenetic analysis of the hemagglutinin genes showed that recent H9N2 strains isolated from chickens in Iran during 2010-2012, formed a distinct subgroup of the previous strains. Recent changes in the H9N2 viruses may be the result of the widespread circulation of these viruses in recent years. This may be due to the lack of adequate surveillance and control programs, such as vaccination and quarantine. Hence, it is highly recommended that continuous surveillance programs and genetic analysis of ongoing changes to H9N2 should be considered.Istražene su inačice gena za hemaglutinin četiriju nedavno izdvojenih izolata podtipa H9N2 virusa influence ptica na području Teherana u Iranu. Geni su umnoženi i sekvencirani s ciljem da se obilježja virusa usporede s prijašnjim izolatima iz Irana i nekih drugih zemalja u svijetu. Analizirani su geni za hemaglutinin u punoj dužini od 112 izolata H9N2 iz pilića i ptica selica iz cijelog svijeta, uključujući i 68 izolata iz Irana od 1998. do 2012. Aminokiselinski sastav na mjestu cijepanja hemaglutinina svih četiriju nedavno izdvojenih izolata sadržavao je PAKSSR/GL motiv, koji je bio različit u usporedbi s prevladavajućim PARSSR/GL u hemaglutininu iranskih sojeva H9N2 izdvojenih prije 2010. Sva četiri izolata posjedovala su histidin, alanin, leucin i izoleucin na pozicijama 183, 190, 226 i 227, koje su ključne za vezanje na receptore. Genetska i filogenetska analiza gena za hemaglutinin pokazala je da izolati H9N2 iz pilića u Iranu izdvojeni od 2010. do 2012. čine posebnu i različitu podskupinu od prijašnjih izolata. Dokazane izmjene tih izolata mogle bi biti uzrok njihova širenja posljednjih godina. To se moglo dogoditi zbog nedostatka odgovarajućeg programa nadzora i kontrole koji bi obuhvaćali cijepljenje i karantenu. Stoga se posebice preporučuje provođenje programa genetske analize te trajnog praćenja trenutnih promjena podtipa H9N2
Influência de tratamento criogênico no comportamento em fadiga estrutural de ligas com memória de forma
Trabalho de conclusão de curso (graduação)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2016.As Ligas com Memória de Forma (LMF) apresentam um grande potencial de aplicação nas mais diversas áreas da engenharia. Nas aplicações que usam esse tipo de material como atuador, nas quais ele é ciclado térmica e/ou mecanicamente, observa-se que a ocorrência de fadiga mecânica e fadiga termomecânica desempenham papel importante. Neste contexto, o objetivo do presente trabalho é avaliar a influência da imersão e do tempo de imersão em temperatura criogênica na vida a fadiga estrutural . Para isso, desenvolve-se uma análise comparativa entre referidas curvas da liga como recebida e tratadas criogenicamente. Corpos de prova da liga Ni48-Ti52 como recebida e imersas em nitrogênio líquido a -196oC, por 12, 18 e 24 horas foram cicladas mecanicamente sob diferentes cargas. A partir de uma análise analítica dos resultados da liga tratada e não tratada observou-se a influência do tratamento criogênico nessas ligas.Shape memory alloy (SMA) presents a great potential of application in diverse areas of engineering. In a special way, in those where these materials are used as actuators, where the material is cycled thermally or mechanicaly, the mechanical and the functional fatigue play an important role. In this sense, this works aims to investigate the influence of deep cryogenic treatment in structural fatigue. For this was carried out an analytical comparative analysis of these properties before and after the cryogenic treatment. The test samples Ni48-Ti52 as received cryogenically treated by immersion at -196oC using different immersion times of 12, 18 and 24 hours. From a analytical analysis of untreated and treated alloy was observed the influence of the cryogenic treatment in these alloys
Evaluating the Possibility of Integrating Augmented Reality and Internet of Things Technologies to Help Patients with Alzheimer's Disease
People suffering from Alzheimer's disease (AD) and their caregivers seek
different approaches to cope with memory loss. Although AD patients want to
live independently, they often need help from caregivers. In this situation,
caregivers may attach notes on every single object or take out the contents of
a drawer to make them visible before leaving the patient alone at home. This
study reports preliminary results on an Ambient Assisted Living (AAL) real-time
system, achieved through the Internet of Things (IoT) and Augmented Reality
(AR) concepts, aimed at helping people suffering from AD. The system has two
main sections: the smartphone or windows application allows caregivers to
monitor patients' status at home and be notified if patients are at risk. The
second part allows patients to use smart glasses to recognize QR codes in the
environment and receive information related to tags in the form of audio, text,
or three-dimensional image. This work presents preliminary results and
investigates the possibility of implementing such a system.Comment: 5 pages, 5 figure
Footstep Adjustment for Biped Push Recovery on Slippery Surfaces
Despite extensive studies on motion stabilization of bipeds, they still
suffer from the lack of disturbance coping capability on slippery surfaces. In
this paper, a novel controller for stabilizing a bipedal motion in its sagittal
plane is developed with regard to the surface friction limitations. By taking
into account the physical limitation of the surface in the stabilization trend,
a more advanced level of reliability is achieved that provides higher
functionalities such as push recovery on low-friction surfaces and prevents the
stabilizer from overreacting. The discrete event-based strategy consists of
modifying the step length and time period at the beginning of each footstep in
order to reestablish stability necessary conditions while taking into account
the surface friction limitation as a constraint to prevent slippage. Adjusting
footsteps to prevent slippage in confronting external disturbances is perceived
as a novel strategy for keeping stability, quite similar to human reaction. The
developed methodology consists of rough closed-form solutions utilizing
elementary math operations for obtaining the control inputs, allowing to reach
a balance between convergence and computational cost, which is quite suitable
for real-time operations even with modest computational hardware. Several
numerical simulations, including push recovery and switching between different
gates on low-friction surfaces, are performed to demonstrate the effectiveness
of the proposed controller. In correlation with human-gait experience, the
results also reveal some physical aspects favoring stability and the fact of
switching between gaits to reduce the risk of falling in confronting different
conditions.Comment: for associated simulation video, see https://youtu.be/BWzUgHGdl3
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