Using a geometric formalism of elasticity theory we develop a systematic theoretical framework for shaping and manipulating the energy landscape of slender solids, and consequently their mechanical ...response to external perturbations. We formally express global mechanical properties associated with non-Euclidean thin sheets in terms of their local rest lengths and rest curvatures, and we interpret the expressions as both forward and inverse problems for designing the desired mechanical properties. We show that by wisely designing geometric frustration, anomalous mechanical properties can be encoded into a material using accessible experimental techniques. To test the methodology we derive a family of ribbon-springs with extreme mechanical behavior such as tunable, anharmonic, and even vanishing rigidities. The presented formalism can be discretized, offering a new methodology for designing mechanical properties and thus opens a new pathway for the design of both continuum and discrete solids and structures.
A geometric theory for manipulating energy landscapes and mechanical properties of thin elastic sheets.
Using a geometric formalism of elasticity theory we develop a systematic theoretical method for controlling and manipulating the mechanical response of slender solids to external loads. We formally ...express global mechanical properties associated with non-euclidean thin sheets, and interpret the expressions as inverse problem for designing desired mechanical properties. We show that by wisely designing geometric frustration, extreme mechanical properties can be encoded into a material using accessible experimental techniques. To test the methodology we derive a family of geometries that result with anomalous mechanical behavior such as tunable, an-harmonic, and even vanishing rigidities. The presented formalism can be discretized and thus opens a new pathway for the design of both continuum and discrete solids and structures.
Animal studies have shown robust electrophysiological activity in the sensory cortex in the absence of stimuli or tasks. Similarly, recent human functional magnetic resonance imaging (fMRI) revealed ...widespread, spontaneously emerging cortical fluctuations. However, it is unknown what neuronal dynamics underlie this spontaneous activity in the human brain. Here we studied this issue by combining bilateral single-unit, local field potentials (LFPs) and intracranial electrocorticography (ECoG) recordings in individuals undergoing clinical monitoring. We found slow (<0.1 Hz, following 1/f-like profiles) spontaneous fluctuations of neuronal activity with significant interhemispheric correlations. These fluctuations were evident mainly in neuronal firing rates and in gamma (40-100 Hz) LFP power modulations. Notably, the interhemispheric correlations were enhanced during rapid eye movement and stage 2 sleep. Multiple intracranial ECoG recordings revealed clear selectivity for functional networks in the spontaneous gamma LFP power modulations. Our results point to slow spontaneous modulations in firing rate and gamma LFP as the likely correlates of spontaneous fMRI fluctuations in the human sensory cortex.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Human brain imaging typically employs structured and controlled tasks to avoid variable and inconsistent activation patterns. Here we expand this assumption by showing that an extremely open-ended, ...high-level cognitive task of thinking about an abstract content, loosely defined as “abstract thinking” - leads to highly consistent activation maps. Specifically, we show that activation maps generated during such cognitive process were precisely located relative to borders of well-known networks such as internal speech, visual and motor imagery. The activation patterns allowed decoding the thought condition at >95%. Surprisingly, the activated networks remained the same regardless of changes in thought content. Finally, we found remarkably consistent activation maps across individuals engaged in abstract thinking. This activation bordered, but strictly avoided visual and motor networks. On the other hand, it overlapped with left lateralized language networks. Activation of the default mode network (DMN) during abstract thought was similar to DMN activation during rest. These observations were supported by a quantitative neuronal distance metric analysis. Our results reveal that despite its high level, and varied content nature - abstract thinking activates surprisingly precise and consistent networks in participants’ brains.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This research examines how faculty members working in complex sociopolitical context cope with campus diversity. Through 20 focus groups comprised of faculty members representing all of the ...departments at one academic institution, we investigated the participants' experiences with student diversity. The findings show that the protracted Israeli-Palestinian conflict seeps into classroom interactions. This infiltration of the protracted conflict is particularly salient during escalations of the conflict. The participants feel they are unable to address these difficulties, experience isolation, fear, and a lack of support. The study expands understanding of how employees cope with political tensions in a real-life setting.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, PRFLJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The aim of the present article is to present a model for teaching qualitative research as part of nursing education. The uniqueness of the course model is that it seeks to combine two objectives: (1) ...initial familiarization of the students with the clinical-nursing environment and the role of the nurse; and (2) understanding the qualitative research approach and inculcation of basic qualitative research skills. The article describes how teaching two central genres in qualitative research – ethnographic and narrative research – constitutes a way of teaching the important skills, concepts, and values of the nursing profession. The article presents the model's structure, details its principal stages, and explains the rationale of each stage. It also presents the central findings of an evaluation of the model's implementation in eight groups over a two-year period. In this way the article seeks to contribute to nursing education literature in general, and to those engaged in clinical training and teaching qualitative research in nursing education in particular.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
FMRI data described here was recorded during resting-state in Mindfulness Meditators (MM) and control participants (see “Task-induced activity and resting-state fluctuations undergo similar ...alterations in visual and DMN areas of long-term meditators” Berkovich-Ohana et al. (2016) 1 for details). MM participants were also scanned during meditation. Analyses focused on functional connectivity within and between the default mode network (DMN) and visual network (Vis). Here we show data demonstrating that: 1) Functional connectivity within the DMN and the Visual networks were higher in the control group than in the meditators; 2) Data show an increase for the functional connectivity between the DMN and the Visual networks in the meditators compared to controls; 3) Data demonstrate that functional connectivity both within and between networks reduces during meditation, compared to the resting-state; and 4) A significant negative correlation was found between DMN functional connectivity and meditation expertise. The reader is referred to Berkovich-Ohana et al. (2016) 1 for further interpretation and discussion.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Morphogen gradients pattern tissues and organs during development. When morphogen production is spatially restricted, diffusion and degradation are sufficient to generate sharp concentration ...gradients. It is less clear how sharp gradients can arise within the source of a broadly expressed morphogen. A recent solution relies on localized production of an inhibitor outside the domain of morphogen production, which effectively redistributes (shuttles) and concentrates the morphogen within its expression domain. Here, we study how a sharp gradient is established without a localized inhibitor, focusing on early dorsoventral patterning of the Drosophila embryo, where an active ligand and its inhibitor are concomitantly generated in a broad ventral domain. Using theory and experiments, we show that a sharp Toll activation gradient is produced through “self-organized shuttling,” which dynamically relocalizes inhibitor production to lateral regions, followed by inhibitor-dependent ventral shuttling of the activating ligand Spätzle. Shuttling may represent a general paradigm for patterning early embryos.
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► Pipe expression at oogenesis defines ventral Spätzle processing domain ► The two Spätzle proteolytic products remain associated and can diffuse dorsally ► Toll binding dissociates Spätzle parts, allowing reformation into an inactive complex ► Ventral cleavage of N-terminal region creates ventral flux of active, C-terminal ligand
An inhibitor that is produced concomitantly with the active Spätzle ligand helps convert a broad domain of Spätzle processing into a sharp gradient of Toll receptor activation by promoting shuttling and accumulation of active Spätzle ligand to a narrow ventral region.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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