CAPITAL ADEQUACY OF HEDGE FUNDS: A VALUE-AT-RISK APPROACH

This paper studies the risk profile and capital adequacy of hedge funds by extending the sample period used in the research of Gupta and Liang (2005). We apply a VaR-based approach to evaluate over 6,000 hedge funds from the Lipper Tass Academic Hedge Fund Database, including live funds and graveyard funds, and find that only a small percentage of them are undercapitalized as of September 2014. By conducting a cross-sectional regression of fund capitalization on various characteristics of hedge funds, we reach a conclusion that whether a hedge fund is adequately capitalized is related to its age and investment style. Standard deviation and leverage ratio often underestimate the market risk hedge funds face, whereas VaR-based measures successfully capture both static and dynamic risk profile of hedge funds

Can technology demonstration promote rural households’ adoption of conservation tillage in China?

Under the uncertainty of conservation tillage on output, technology demonstration, as an information disclosure mechanism, is very worthy of attention for its effects on rural households’ conservation tillage adoption. This study constructs a three-stage technology adoption model to discuss the theoretical relationship between technology demonstration and rural households’ conservation tillage adoption decision, and then empirical analyzed it using a sampling rural household data from six provinces in the main grain-producing areas of China. The results show that: First, the cognition of conservation tillage is the pre-determined stage for the adoption and its intensity. Second, technology demonstration has significant positive effect on rural households’ cognition of conservation tillage, but it strongly negative related to the adoption and adoption intensity. Third, extending the technology demonstration time cannot change the rural households’ adoption decision. Fourth, the technological demonstration has similar effects on the conservation tillage adoption of small-scale and large-scale farmers. Fifth, increasing land size helps rural households to adopt conservation tillage, while land fragmentation hinders their adoption

PhotoScout: Synthesis-Powered Multi-Modal Image Search

Due to the availability of increasingly large amounts of visual data, there is a growing need for tools that can help users find relevant images. While existing tools can perform image retrieval based on similarity or metadata, they fall short in scenarios that necessitate semantic reasoning about the content of the image. This paper explores a new multi-modal image search approach that allows users to conveniently specify and perform semantic image search tasks. With our tool, PhotoScout, the user interactively provides natural language descriptions, positive and negative examples, and object tags to specify their search tasks. Under the hood, PhotoScout is powered by a program synthesis engine that generates visual queries in a domain-specific language and executes the synthesized program to retrieve the desired images. In a study with 25 participants, we observed that PhotoScout allows users to perform image retrieval tasks more accurately and with less manual effort

Analyzing the effects of physical activity levels on aggressive behavior in college students using a chain-mediated model

This study aims to examine the mediating role of self-efficacy (SE) and self-control (SC) in the relationship between physical activity (PA) and aggressive behaviors (AB) among college students. It provides a basis for the prevention and control of AB among college students. This study employed a survey research methodology, including the PA Level Scale, the General Self-efficacy Scale, the Self-control Scale, and the Chinese Aggressive Behaviors Scale on 950 college students. The chain mediating effect test and Bootstrap analysis were applied. The results were as follows: (1) There was a main effect of PA on SE, SC, and AB as well as all sub-indicators (physical aggression, verbal aggression, anger, hostility, self-directed aggression), i.e., PA had a direct effect on the control of all three; (2) PA level was significantly negatively correlated with AB and significantly positively correlated with SE and SC. That is, the higher the level of PA, the better the SE and SC, and the lower the probability of AB; (3) The three pathways had mediating effects: PA → SE → AB, PA → SC → AB, PA → SE → SC → AB, with effect sizes of 8.78%, 28.63%, and 19.08%, respectively. It is concluded that regular PA is a potent method for decreasing aggressive behavior and psychological issues in university students while additionally promoting self-efficacy and self-control. Increasing the intensity of PA may enhance the effectiveness of these chain benefits

Dynamic S-acylation of the Er-resident Protein Stromal Interaction Molecule 1 (Stim1) is Required for Store-operated Ca2+ Entry

Many cell surface stimuli cause calcium release from endoplasmic reticulum (ER) stores to regulate cellular physiology. Upon ER calcium store depletion, the ER-resident protein stromal interaction molecule 1 (STIM1) physically interacts with plasma membrane protein Orai1 to induce calcium release-activated calcium (CRAC) currents that conduct calcium influx from the extracellular milieu. Although the physiological relevance of this process is well established, the mechanism supporting the assembly of these proteins is incompletely understood. Earlier we demonstrated a previously unknown post-translational modification of Orai1 with long-chain fatty acids, known as S-acylation. We found that S-acylation of Orai1 is dynamically regulated in a stimulus-dependent manner and essential for its function as a calcium channel. Here using the acyl resin-assisted capture assay, we show that STIM1 is also rapidly S-acylated at cysteine 437 upon ER calcium store depletion. Using a combination of live cell imaging and electrophysiology approaches with a mutant STIM1 protein, which could not be S-acylated, we determined that the S-acylation of STIM1 is required for the assembly of STIM1 into puncta with Orai1 and full CRAC channel function. Together with the S-acylation of Orai1, our data suggest that stimulus-dependent S-acylation of CRAC channel components Orai1 and STIM1 is a critical mechanism facilitating the CRAC channel assembly and function