Rust is a relatively new programming language that targets efficient and safe systems-level applications. It includes a sophisticated type system that allows for provable memory- and thread-safety, and is explicitly d...
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Rust is a relatively new programming language that targets efficient and safe systems-level applications. It includes a sophisticated type system that allows for provable memory- and thread-safety, and is explicitly designed to take the place of unsafe languages such as c and c++ in the coding ecosystem. There is a large existing c and c++ codebase (many of which have been affected by bugs and security vulnerabilities due to unsafety) that would benefit from being rewritten in Rust to remove an entire class of potential bugs. However, porting these applications to Rust manually is a daunting task. In this paper we investigate the problem of automatically translating c programs into safer Rust programs- that is, Rust programs that improve on the safety guarantees of the original c programs. We conduct an in-depth study into the underlying causes of unsafety in translated programs and the relative impact of fixing each cause. We also describe a novel technique for automatically removing a particular cause of unsafety and evaluate its effectiveness and impact. This paper presents the first empirical study of unsafety in translated Rust programs (as opposed to programs originally written in Rust) and also the first technique for automatically removing causes of unsafety in translated Rust programs.
The large ownership of direct-expansion (DX) air-conditioning (A/c) systems in small and medium-sized buildings brings with it the need to reduce their energy consumption without damaging the thermal comfort of the oc...
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The large ownership of direct-expansion (DX) air-conditioning (A/c) systems in small and medium-sized buildings brings with it the need to reduce their energy consumption without damaging the thermal comfort of the occupants. Model predictive control (MPc) is an effective method to optimally control the operation of air-conditioners. However, most existing MPc methods require the investment of additional equipment and labor-intensive work, which greatly increases the cost of MPc and hinders its practical application. To solve the problem, this paper presents an economical and practical MPc algorithm for DX A/c systems, capable of achieving a balance between thermal comfort and energy saving. The proposed algorithm was experimentally validated on both an experimental DX A/c system and a market available split-type air-conditioner. Experi-mental results on the experimental DX A/c system show that temperature and humidity set-points selected at alpha = 1 saved 23.3% of energy consumption compared to those selected at alpha = 0, while keeping indoor thermal comfort within acceptable range. And results on the split-type air-conditioner demonstrate energy savings of up to more than 32% compared to the baseline and proved that the algorithm can be practically applied on market available D/X air-conditioners.
Ageing is a biological process guided by genetic and environmental factors that ultimately lead to adverse outcomes for organismal lifespan and healthspan. Determination of molecular pathways that are affected with ag...
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Ageing is a biological process guided by genetic and environmental factors that ultimately lead to adverse outcomes for organismal lifespan and healthspan. Determination of molecular pathways that are affected with age and increase disease susceptibility is crucial. The gene expression profile of the ideal ageing model, namely the nematode caenorhabditis elegans mapped with the microarray technology initially led to the identification of age-dependent gene expression alterations that characterize the nematode's ageing process. The list of differentially expressed genes was then utilized to construct a network of molecular interactions with their first neighbors/interactors using the interactions listed in the WormBase database. The subsequent network analysis resulted in the unbiased selection of 110 candidate genes, among which well-known ageing regulators appeared. More importantly, our approach revealed candidates that have never been linked to ageing before, thus suggesting promising potential targets/ageing regulators.
a-Synuclein is a major component of Lewy bodies and Lewy neuritis which are hallmarks of Parkinson's disease, and is known to propagate from cell-to-cell in a prion-like manner. However, the exact mechanism of a-s...
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a-Synuclein is a major component of Lewy bodies and Lewy neuritis which are hallmarks of Parkinson's disease, and is known to propagate from cell-to-cell in a prion-like manner. However, the exact mechanism of a-synuclein propagation in cells remains unclear. Despite the increasing number of studies and models of a-synuclein propagation, there is no direct evidence demonstrating whether the propagation is trans-synaptic or synapticconnection-independent, what the direction of propagation is, and what the regulators of a-synuclein propagation are. In this study, we generated a caenorhabditis elegans model that can help monitoring the neuron-to-neuron propagation of a-synuclein using BiFc system. Using this model, we demonstrated that a-synuclein was propagated into neurons in both anterograde and retrograde manners, with retrograde propagation being dominant. Interestingly, we also found that endophilin, which is a protein required for classical clathrin-mediated endocytic machinery, was not involved in this retrograde propagation. Furthermore, we demonstrated that a-synuclein inhibits neuronal activity through voltage-gated calcium channels. Our findings suggest a possible mechanism for a-synuclein propagation via synapses through a novel uptake pathway.
The hybridization experiments have been made between crassostrea ariakensis and c. gigas several times. However, it is difficult to obtain a large number of hybrid offspring, which becomes the bottleneck of subsequent...
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The hybridization experiments have been made between crassostrea ariakensis and c. gigas several times. However, it is difficult to obtain a large number of hybrid offspring, which becomes the bottleneck of subsequent cross-breeding. To explore whether the production of hybrid larvae is affected by salinity, we investigated the effects of salinity (16, 20, 24, 28 and 32 psu) on the early activities of artificial hybridization between c. ariakensis and c. gigas at 23-24 degrees c. In this study, the results showed that during artificial insemination, the appropriate salinity of high-quality gametes in c. ariakensis and c. gigas was 20-32 psu and 24-32 psu respectively. Besides, the fertilization rate of AG (c. ariakensis female x c. gigas male) and GA (c. gigas female x c. ariakensis male) at 24-28 psu was significantly (p < .05) higher than that at 16-20 psu. For incubation, the optimal salinity of embryo incubation was 28 psu, under which all embryos of AG and GA can develop rapidly to the D-larvae and yielded a high hatching rate. During larval rearing, the larval shell height and survival rate of AG were of no significant difference (p > .05) at all salinities, and the optimum salinity for larval growth and survival of GA was 24-28 psu. These findings can contribute to the increase in the hybrid progeny yield, which can serve as the new resource for genetic improvement of oyster germplasm.
Several biogerontology databases exist that focus on genetic or gene expression data linked to health as well as survival, subsequent to compound treatments or genetic manipulations in animal models. However, none of ...
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Several biogerontology databases exist that focus on genetic or gene expression data linked to health as well as survival, subsequent to compound treatments or genetic manipulations in animal models. However, none of these has yet collected experimental results of compound-related health changes. Since quality of life is often regarded as more valuable than length of life, we aim to fill this gap with the "Healthy Worm Database" (). Literature describing health-related compound studies in the aging model caenorhabditis elegans was screened, and data for 440 compounds collected. The database considers 189 publications describing 89 different phenotypes measured in 2995 different conditions. Besides enabling a targeted search for promising compounds for further investigations, this database also offers insights into the research field of studies on healthy aging based on a frequently used model organism. Some weaknesses of c. elegans-based aging studies, like underrepresented phenotypes, especially concerning cognitive functions, as well as the convenience-based use of young worms as the starting point for compound treatment or phenotype measurement are discussed. In conclusion, the database provides an anchor for the search for compounds affecting health, with a link to public databases, and it further highlights some potential shortcomings in current aging research.
The thermal analysis method for unidirectional fiber-reinforced c/Siccomposites (c/Sic-UFRc) in air oxidizing environment below 1000 degrees c is developed, including a mathematical theoretical model and a finite ele...
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The thermal analysis method for unidirectional fiber-reinforced c/Siccomposites (c/Sic-UFRc) in air oxidizing environment below 1000 degrees c is developed, including a mathematical theoretical model and a finite element model. The mathematical model (MM) is established by combining the thermal resistance network method and the oxidation kinetics theory. The influence of oxidation characteristics on c/Sic-UFRc axial thermal conduc-tivity is firstly introduced into MM, which provides a reference for the theoretical calculation method of c/Sic-UFRc axial thermal conductivity under oxidation conditions. The finite element model (FEM) is constructed on the representative volume element (RVE) of c/Sic-UFRc and the numerical heat transfer method. The FEM numerically simulated the microstructure in the oxidation process and firstly be applied to study the effects of oxidation on the micro temperature field and heat transfer of c/Sic-UFRc. Through the mutual confirmation of MM and FEM, the prediction of thermal conductivity of cMc in air oxidation environment is verified. The effects of oxidation time, oxidation temperature and random distribution of initial cracks are investigated to reveal their influences on the heat transfer behavior of c/Sic-UFRc.
Engineering high-performance inexpensive TaN-modified Pd-based nanostructures for alkaline methanol oxidation reaction(MOR) has attracted extensive attention, yet the related enhancement mechanism of TaN for MOR remai...
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Engineering high-performance inexpensive TaN-modified Pd-based nanostructures for alkaline methanol oxidation reaction(MOR) has attracted extensive attention, yet the related enhancement mechanism of TaN for MOR remains lacked. The core-shell like Pd3Ni1-TaN/ccatalyst decorated with Ni(OH)2/NiOOH that contains highly dispersed Ni sites and nitrogen defects has been fabricated for the first time. The unsaturated coordination environment and core-shell like morphology of Pd3Ni1-TaN/c bring fruitful active sites and a down-shifted Dband center, making it a highly-efficient electrocatalyst for alkaline MOR (17.3-fold that of commercial Pd/c). Besides the electronic effects and surface defect sites of Pd3Ni1-TaN/c, TaN also helps MOR proceed via HcOOad pathway (non-cO) accompanied by enhanced OH adsorption induced by the addition of Ni. DFT(Density Functional Theory) calculations also further confirm the energy barrier of the formation of HcOOad intermediate and desorption energy of cO on Pd3Ni1-TaN/c are reduced. The introduction of Ni species and nitrogen vacancies enhances the cO tolerance evidently.
c/Siccomposites are the preferred materials for high temperature resistant (usually above 1500 degrees c) structural parts in aerospace, aviation, shipbuilding, and other industries. When this kind of material compon...
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c/Siccomposites are the preferred materials for high temperature resistant (usually above 1500 degrees c) structural parts in aerospace, aviation, shipbuilding, and other industries. When this kind of material component is processed efficiently by grinding, the damage forms of fiber step brittle fracture and fiber pulling out are often produced on the machined surface/subsurface. The existence of these damage forms deteriorates the quality of the machine surface and may reduce the bending strength of materials to a certain extent. Therefore, it is very important to study the mechanism and the damage law of ordinary grinding and ultrasonic vibration-assisted grinding and take reasonable measures to restrain the machining damage. In this paper, the typical damage forms of c/Siccomposites during the end and side grinding are explored. The surface and subsurface damage degree of c/Siccomposites during grinding and ultrasonic vibration-assisted grinding were compared. The effects of different process parameters on material damage were compared and analyzed. The results show that the damage forms of ordinary grinding and ultrasonic grinding are basically the same. compared with ordinary grinding, ultrasonic-assisted grinding can reduce surface damage to a certain extent and subsurface damage significantly.
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