1,725,727 research outputs found
Atefeh Khazeni, Peter H. Adler, Zakieh Telmadareiiy, Mohammad Ali Oshaghi1,*, Hasan Vatandoost, Seyed Mohammad Abtahi & Abolfazl Lotfi
No full textKhazeni, Atefeh, Adler, Peter H., Telmadareiiy, Zakieh, Oshaghi, Mohammad Ali, Vatandoost, Hasan, Abtahi, Seyed Mohammad, Lotfi, Abolfazl (2013): Atefeh Khazeni, Peter H. Adler, Zakieh Telmadareiiy, Mohammad Ali Oshaghi1,*, Hasan Vatandoost, Seyed Mohammad Abtahi & Abolfazl Lotfi. Zootaxa 3718 (6): 600-600, DOI: 10.11646/zootaxa.3718.6.
What’s My Research? with Dr. Atefeh Rabiee and Mike Wurtz
No full textPlease join us on Thursday, September 26, from noon to 1 pm in the Yosemite Classroom (1st floor of the Library) for “What’s My Research?” featuring Dr. Atefeh Rabiee (Physiology/Pharmacology) and Mike Wurtz (Special Collections).
Dr. Rabiee’s research is centered on uncovering the mechanisms behind lipedema fat resistance. Lipedema is a chronic condition where fat accumulates abnormally in the legs, hips, and arms, causing pain, swelling, and bruising. Unlike typical fat, it doesn\u27t respond to diet or exercise. Identifying the causes of lipedema is crucial for improving diagnosis and developing effective treatments, as the condition is often misdiagnosed as obesity.
Mr. Wurtz is head of the University of the Pacific Holt-Atherton Special Collections and Archives, where he oversees the use and preservation of the historical archives such as the John Muir Papers, the George Moscone Collection, and Japanese American Internment during WWII collections. Nineteenth-century naturalist John Muir made hundreds of drawings of Yosemite. Find out where Muir drew them and hear some stories about him and Yosemite from the curator of Muir’s largest archival collection.
A light lunch will be served
What’s My Research? with Dr. Atefeh Rabiee and Mike Wurtz
No full textPlease join us on Thursday, September 26, from noon to 1 pm in the Yosemite Classroom (1st floor of the Library) for “What’s My Research?” featuring Dr. Atefeh Rabiee (Physiology/Pharmacology) and Mike Wurtz (Special Collections).
Dr. Rabiee’s research is centered on uncovering the mechanisms behind lipedema fat resistance. Lipedema is a chronic condition where fat accumulates abnormally in the legs, hips, and arms, causing pain, swelling, and bruising. Unlike typical fat, it doesn\u27t respond to diet or exercise. Identifying the causes of lipedema is crucial for improving diagnosis and developing effective treatments, as the condition is often misdiagnosed as obesity.
Mr. Wurtz is head of the University of the Pacific Holt-Atherton Special Collections and Archives, where he oversees the use and preservation of the historical archives such as the John Muir Papers, the George Moscone Collection, and Japanese American Internment during WWII collections. Nineteenth-century naturalist John Muir made hundreds of drawings of Yosemite. Find out where Muir drew them and hear some stories about him and Yosemite from the curator of Muir’s largest archival collection.
A light lunch will be served
Peridynamic modeling of inelastic materials for aerospace applications
No full textStudy of the mechanical behavior of ductile materials is essential in engineering and materials science due to the widespread use of these materials in industry. Ductile materials are known for their ability to deform significantly before fracture, and this has contributed to their extensive adoption in many industrial sectors such as aerospace, automotive, and structural engineering.
Ductile materials undergo elastoplastic deformation prior to fracture. This process reduces the stiffness of the material before failure. When a material is loaded, it initially exhibits elastic behavior. A surface in the stress space known as the yield surface controls the initiation of the plastic deformation. Plastic deformation occurs when the stress in the material remains on the yield surface throughout the loading process. Furthermore, to reflect the real behavior observed in most ductile materials, the size of the yield surface is controlled by adding a hardening/softening assumption to the formulation.
The linear elastic fracture mechanics (LEFM) approach, which neglects yielding at the crack front, is not reliable for simulating the mechanical behavior of ductile materials that undergo significant deformation under service loads. In contrast, the elasto-plastic fracture mechanics (EPFM) approach considers the impact of yielding at crack tips and characterizes the plastic behavior of the material. Consequently, it is appropriate for analysing ductile materials.
Moreover, the deformation of all metals is, to some extent, time-dependent. This behavior can be effectively characterized by elasto-viscoplasticity. This framework accounts for the time-dependent inelastic strains observed in solids. The Perzyna constitutive law, with its simple formulation, accurately simulates the evolution of viscous effects and is thus widely employed in engineering applications.
Classical continuum mechanics is a theory that establishes the mathematical foundation for the study of the mechanical behavior of ductile materials. However, fracture analysis is challenging, especially when it is approached within the framework of the classical mechanics theory because this theory uses partial derivatives in the equation of motion, which require continuity of the displacement field. This assumption becomes problematic when dealing with discontinuities such as cracks.
Peridynamics is a nonlocal theory of solid mechanics designed for discontinuous problems. It is well suited to failure analysis because it uses integral equations rather than partial differential equations. It redefines the equation of motion and improves its suitability for solving problems involving cracks. However, since it is a recently introduced theory, Peridynamics is not equipped with all constitutive laws normally available for classical continuum mechanics.
Therefore, it is reasonable to develop a peridynamic elastoplastic model for the study of the mechanical behaviour of ductile materials. The main purpose of this dissertation is to develop peridynamic approaches to simulate both elastoplastic materials and elasto-viscoplastic materials with strain hardening. The elastoplastic model is based on the classical theory of plasticity. The model is capable of simulating the elastoplastic behavior of materials with isotropic, kinematic and combined hardening. The elasto-viscoplastic peridynamic model is based on the Perzyna constitutive law. For materials with hardening, the yield surface changes with any change in plastic strain, a behavior observed in most materials. This effect is duly taken into account in the proposed models. We shall briefly show that the proposed approaches are well suited for fracture analysis of ductile materials. Several examples, including 2D plane stress and plane strain, and 3D cases, are performed to demonstrate the capabilities of the proposed approaches
Identified Serotonin-Releasing Neurons Induce Behavioral Quiescence and Suppress Mating in Drosophila
No full textAnimals show different levels of activity that are reflected in sensory responsiveness and endogenously generated behaviors. Biogenic amines have been determined to be causal factors for these states of arousal. It is well established that, in Drosophila, dopamine and octopamine promote increased arousal. However, little is known about factors that regulate arousal negatively and induce states of quiescence. Moreover, it remains unclear whether global, diffuse modulatory systems comprehensively affecting brain activity determine general states of arousal. Alternatively, individual aminergic neurons might selectively modulate the animals' activity in a distinct behavioral context. Here, we show that artificially activating large populations of serotonin-releasing neurons induces behavioral quiescence and inhibits feeding and mating. We systematically narrowed down a role of serotonin in inhibiting endogenously generated locomotor activity to neurons located in the posterior medial protocerebrum. We identified neurons of this cell cluster that suppress mating, but not feeding behavior. These results suggest that serotonin does not uniformly act as global, negative modulator of general arousal. Rather, distinct serotoninergic neurons can act as inhibitory modulators of specific behaviors.German Research Foundation [FI 821/3-1
Commemorating Karbala’s Youngest Martyr in Iran
No full textThis article explores recent ritual developments in the Iranian religious culture honouring Ali-Asqar (d. 680 CE), the infant son of Imam Husayn. In 2003, a new ritual, the Husayni Infancy Conference, was introduced. The ritual is the only public Muharram assembly dedicated to women and their infants. Based on observation and interviews, I identify ritual transformations, terms of institutionalisation, and the staging of rituals and their structure, and I also examine the objectives behind the Conference from the perspectives of the organisers and participants. I argue that the organisers seek to promote new interpretations of the significance of the Battle of Karbala. This objective is shared by some participants whereas many continue to seek out traditional reasons to commemorate the Battle, such as receiving God’s blessings. Attending large ritual gatherings also offers opportunities for socialising and empowerment
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