1,921 research outputs found
On the Empirics of Sudden Stops: The Relevance of Balance-Sheet Effects
Using a sample of 32 developed and developing countries we analyze the empirical characteristics of sudden stops in capital flows and the relevance of balance sheet effects in the likelihood of their materialization. We find that large real exchange rate (RER) fluctuations coming hand in hand with Sudden Stops are basically an emerging market (EM) phenomenon. Sudden Stops seem to come in bunches, grouping together countries that are different in many respects. However, countries are similar in that they remain vulnerable to large RER fluctuations – be it because they could be forced to large adjustments in the absorption of tradable goods, and/or because the size of dollar liabilities in the banking system (i.e., domestic liability dollarization, or DLD) is high. Openness, understood as a large supply of tradable goods that reduces leverage over the current account deficit, coupled with DLD, are key determinants of the probability of Sudden Stops. The relationship between Openness and DLD in the determination of the probability of Sudden Stops is highly non-linear, implying that the interaction of high current account leverage and high dollarization may be a dangerous cocktail.
Virtual body in immersive virtual reality and its influence on creativity
The relationship between the design process, its multiple stages, and how different design mediums affect this process continues to be a topic for research and exploration. The selection of different design tools is done according to the characteristics of the multiple stages within this process. Multiple studies have argued that digital media tools are still incapable of supporting idea development in conceptual stages, but digital mediums have evolved, and digital tools are present in the design process from the beginning to the end. Current digital mediums can provide immersive characteristics in virtual environments that increase the user's sense of presence and embodiment, affecting cognition. Thus, there was a critical need to evaluate and explore how new digital media with multiple levels of embodiment can affect creativity and learning outcomes in conceptual ideation stages of the design process.In addition to presence and embodiment, creativity and spatial abilities are crucial elements for designers. The primary objective of this study was to assess creativity and spatial abilities, examining three different levels of embodiment (first-person online virtual body [VB], first-person offline VB, and third-person online VB). Participants were randomly assigned to one of the three conditions and were required to solve a design task. Pre and post-test questionnaires were used to collect data in addition to a psychophysiological device to account for cognitive load. Spatial skills were assessed before and after the intervention, and the designed outcomes were evaluated to measure the level of creativity. The central hypothesis was that the higher the sense of embodiment (SoE), the greater the presence and lower the cognitive demand of the system, which can be used to improve spatial abilities and stimulate creativity.This study explored how creativity of the designed outcomes and spatial abilities were affected by different levels of embodiment. This study provides relevant information on how VR environments positively affect the development of spatial abilities. Also, the findings facilitate discernment in how different VR setups affect cognitive load on participants, which may ultimately affect cognition and creative thinking
A Novel Hap1-Tsc1 interaction regulates neuronal mTORC1 signaling and morphogenesis in the brain
Tuberous sclerosis complex (TSC) is a leading genetic cause of autism. The TSC proteins Tsc1 and Tsc2 control the mTORC1 signaling pathway in diverse cells, but how the mTORC1 pathway is specifically regulated in neurons remains to be elucidated. Here, using an interaction proteomics approach in neural cells including neurons, we uncover the brain-enriched protein huntingtin-associated protein 1 (Hap1) as a novel functional partner of Tsc1. Knockdown of Hap1 promotes specification of supernumerary axons in primary hippocampal neurons and profoundly impairs the positioning of pyramidal neurons in the mouse hippocampus in vivo. The Hap1 knockdown-induced phenotypes in primary neurons and in vivo recapitulate the phenotypes induced by Tsc1 knockdown. We also find that Hap1 knockdown in hippocampal neurons induces the downregulation of Tsc1 and stimulates the activity of mTORC1, as reflected by phosphorylation of the ribosomal protein S6. Inhibition of mTORC1 activity suppresses the Hap1 knockdown-induced polarity phenotype in hippocampal neurons. Collectively, these findings define a novel link between Hap1 and Tsc1 that regulates neuronal mTORC1 signaling and neuronal morphogenesis, with implications for our understanding of developmental disorders of cognition
Reinforcement of Polymeric Nanoassemblies for Ultra-High Drug Loadings, Modulation of Stiffness and Release Kinetics, and Sustained Therapeutic Efficacy
The optimization of current polymeric nanoparticle therapies is restricted by low drug loadings and limited tunability of core properties. To overcome these shortcomings, a novel self-association approach is utilized to fabricate a dual-loaded poly(1,2-glycerol carbonate)-graft-succinic acid-paclitaxel (PGC-PTX) conjugate nanoparticle (NP) in which the physical entrapment of free paclitaxel (PTX) affords unprecedented ultra-high drug loadings >100 wt%, modulation of mechanical stiffness, and tunable release kinetics. Despite high incorporation of free PTX (up to 50 wt%), the dual-loaded PGC-PTX nanocarriers (i.e., PGC-PTX + PTX NPs) exhibit controlled and sustained drug release over 15 days, without burst release effects. Importantly, optimization of drug/material efficiency concomitantly affords improved in vitro efficacy. In vivo, PGC-PTX + PTX NPs are safely administered at doses exceeding the median lethal dose of standard PTX, while a single high dose significantly extends survival relative to weekly PTX administrations in a murine model of peritoneal carcinomatosis
ECOLOGICAL IMPLICATIONS OF ANTI-PATHOGEN EFFECTS OF TROPICAL FUNGAL ENDOPHYTES AND MYCORRHIZAE
We discuss studies of foliar endophytic fungi (FEE) and arbuscular mycorrhizal fungi (AMF) associated with Theobroma cacao in Panama. Direct, experimentally controlled comparisons of endophyte free (E—) and endophyte containing (E+) plant tissues in T. cacao show that foliar endophytes (FEE) that commonly occur in healthy host leaves enhance host defenses against foliar damage due to the pathogen (Phytophthora palmivora). Similarly, root inoculations with commonly occurring AMF also reduce foliar damage due to the same pathogen. These results suggest that endophytic fungi can play a potentially important mutualistic role by augmenting host defensive responses against pathogens. There are two broad classes of potential mechanisms by which endophytes could contribute to host protection: (1) inducing or increasing the expression of intrinsic host defense mechanisms and (2) providing additional sources of defense, extrinsic to those of the host (e.g., endophytebased chemical antibiosis). The degree to which either of these mechanisms predominates holds distinct consequences for the evolutionary ecology of host-endophyte-pathogen relationships. More generally, the growing recognition that plants are composed of a mosaic of plant and fungal tissues holds a series of implications for the study of plant defense, physiology, and genetics.We discuss studies of foliar endophytic fungi (FEE) and arbuscular mycorrhizal fungi (AMF) associated with Theobroma cacao in Panama. Direct, experimentally controlled comparisons of endophyte free (E—) and endophyte containing (E+) plant tissues in T. cacao show that foliar endophytes (FEE) that commonly occur in healthy host leaves enhance host defenses against foliar damage due to the pathogen (Phytophthora palmivora). Similarly, root inoculations with commonly occurring AMF also reduce foliar damage due to the same pathogen. These results suggest that endophytic fungi can play a potentially important mutualistic role by augmenting host defensive responses against pathogens. There are two broad classes of potential mechanisms by which endophytes could contribute to host protection: (1) inducing or increasing the expression of intrinsic host defense mechanisms and (2) providing additional sources of defense, extrinsic to those of the host (e.g., endophytebased chemical antibiosis). The degree to which either of these mechanisms predominates holds distinct consequences for the evolutionary ecology of host-endophyte-pathogen relationships. More generally, the growing recognition that plants are composed of a mosaic of plant and fungal tissues holds a series of implications for the study of plant defense, physiology, and genetics
Freshwater Prawns (Palaemonidae: Macrobrachium) with Abbreviated Larval Development in Rivers of Mexico: Uses, Management, and Conservation Opportunities
The Macrobrachium genus in Mexico is represented by two big groups: the first one, where the larval stages are extended, and the second one, has an abbreviated larval development. There are three main slopes in Mexico or exorheic basins and several endorheic basins such as lakes and inner lagoons. The species with extended larval stage are M. carcinus, M. heterochirus, M. acanthurus, M. olfersii, M. hobbsi, and M. faustinum in the Atlantic and Caribbean slope, while in the Pacific slope, these species are M. americanum, M. occidentale, M. digueti, M. michoacanus, M. acanthochirus, and M. tenellum. These species have important fishery activities on different basins because they live from oasis in desert to main rivers in the bigger basins. However, there are some rivers that have an extended region on their upstream such as Usumacinta, Grijalva, Papaloapan, and Coatzacoalcos basins that in general are considered as hydrological regions. Just in these extended regions, there are more caves in freshwater, springs, and primary or secondary streams, which are covered by short area rivers, and in these places, there are the following species: M. totonacum, M. tuxtlaense, M. oaxacae, M. cosolapaense, M. oaxacae, M. jacatepecense, M. mazatecum, and M. vicconi, while in the cave are M. villalobosi, M. acherontium, and M. sbordonii. However, for these species, the uses are more for the local groups mainly indigenous cultures such as Mayan, Lacandon, Zapotecs and Mixtecs, and others, and their commercial use is only in the local region depending on where these species are distributed
Flujo de potencia trifásico desbalanceado en sistemas de distribución con generación distribuida
En los últimos años, el número de unidades de generación distribuida integradas en las redes de distribución se ha venido incrementado. Bajo este nuevo escenario, la red de distribución deja de comportarse como una red pasiva y por lo tanto, los métodos tradicionales para flujo de carga en sistemas de distribución deben ser modificados. En este artículo se presenta un algoritmo de flujo de potencia trifásico desbalanceado con generación distribuida. El sistema IEEE de 34 barras fue usado para validar el algoritmo propuesto y para mostrar el efecto de la generación distribuida en las redes de distribución. En las pruebas realizadas se compara el impacto de la generación distribuida modelada como un nodo PV con el impacto de los reguladores de tensión
Flujo de potencia trifásico desbalanceado en sistemas de distribución con generación distribuida
En los últimos años, el número de unidades de generación distribuida integradas en las redes de distribución se ha venido incrementado. Bajo este nuevo escenario, la red de distribución deja de comportarse como una red pasiva y por lo tanto, los métodos tradicionales para flujo de carga en sistemas de distribución deben ser modificados. En este artículo se presenta un algoritmo de flujo de potencia trifásico desbalanceado con generación distribuida. El sistema IEEE de 34 barras fue usado para validar el algoritmo propuesto y para mostrar el efecto de la generación distribuida en las redes de distribución. En las pruebas realizadas se compara el impacto de la generación distribuida modelada como un nodo PV con el impacto de los reguladores de tensión
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