158 research outputs found

    Is GitHub's Copilot as Bad as Humans at Introducing Vulnerabilities in Code?

    Full text link
    Several advances in deep learning have been successfully applied to the software development process. Of recent interest is the use of neural language models to build tools, such as Copilot, that assist in writing code. In this paper we perform a comparative empirical analysis of Copilot-generated code from a security perspective. The aim of this study is to determine if Copilot is as bad as human developers - we investigate whether Copilot is just as likely to introduce the same software vulnerabilities that human developers did. Using a dataset of C/C++ vulnerabilities, we prompt Copilot to generate suggestions in scenarios that previously led to the introduction of vulnerabilities by human developers. The suggestions are inspected and categorized in a 2-stage process based on whether the original vulnerability or the fix is reintroduced. We find that Copilot replicates the original vulnerable code ~33% of the time while replicating the fixed code at a ~25% rate. However this behavior is not consistent: Copilot is more susceptible to introducing some types of vulnerability than others and is more likely to generate vulnerable code in response to prompts that correspond to older vulnerabilities than newer ones. Overall, given that in a substantial proportion of instances Copilot did not generate code with the same vulnerabilities that human developers had introduced previously, we conclude that Copilot is not as bad as human developers at introducing vulnerabilities in code

    Copilot Security: A User Study

    Full text link
    Code generation tools driven by artificial intelligence have recently become more popular due to advancements in deep learning and natural language processing that have increased their capabilities. The proliferation of these tools may be a double-edged sword because while they can increase developer productivity by making it easier to write code, research has shown that they can also generate insecure code. In this paper, we perform a user-centered evaluation GitHub's Copilot to better understand its strengths and weaknesses with respect to code security. We conduct a user study where participants solve programming problems, which have potentially vulnerable solutions, with and without Copilot assistance. The main goal of the user study is to determine how the use of Copilot affects participants' security performance. In our set of participants (n=25), we find that access to Copilot accompanies a more secure solution when tackling harder problems. For the easier problem, we observe no effect of Copilot access on the security of solutions. We also observe no disproportionate impact of Copilot use on particular kinds of vulnerabilities

    Molluscan resources of Kali river estuarine system in Karnataka

    Get PDF
    The present work has shown that there is an organized clam fishery for Meretrix meretrix, Paphia malabarica and Villorita cyprinoides in Kali River. The three species of clams show differential distribution. Paphia malabarica is confined to lower reaches of river from the river mouth to Nandangadda where salinity is 33.44%o suggesting that this species has distinct preference for areas where salinity is high. Meretrix meretrix occurs over a distance of 6.25 km from Nandangadda where the salinity is 30.82%o to Kinnar where the salinity is 8.76%o. Villorita cyprinoids is distributed only in low salinity areas in the upper parts of the river from Botjug to Mallapur where salinity is uniformly low fluctuating between 5.7%o and 0.24%o indicating that this species thrives well in low salinity conditions. During the survey conducted in November- December, 1978 observations were made on the environmental conditions, species composition of the molluscan resources, their distribution pattern, exploitation and marketing and the findings are presented in this paper

    Experimental study of the settlement and collection Of pearl oyster spat from Tuticorin area

    Get PDF
    For the first time settlement and growth of pearl oyst«rs have be-en observed on granite stones forming the embankments of the New Tuticorin Port. Large numbers of pearl oyster spat have also been collected by employing diflfeirent types of spat collectors and the rate of growth of the oysters in the farm has been studied

    Effects of Test-Driven Development : A Comparative Analysis of Empirical Studies

    Get PDF
    Test-driven development is a software development practice where small sections of test code are used to direct the development of program units. Writing test code prior to the production code promises several positive effects on the development process itself and on associated products and processes as well. However, there are few comparative studies on the effects of test-driven development. Thus, it is difficult to assess the potential process and product effects when applying test-driven development. In order to get an overview of the observed effects of test-driven development, an in-depth review of existing empirical studies was carried out. The results for ten different internal and external quality attributes indicate that test-driven development can reduce the amount of introduced defects and lead to more maintainable code. Parts of the implemented code may also be somewhat smaller in size and complexity. While maintenance of test-driven code can take less time, initial development may last longer. Besides the comparative analysis, this article sketches related work and gives an outlook on future research.Peer reviewe

    Toward a first-principles integrated simulation of tokamak edge plasmas

    Get PDF
    Performance of the ITER is anticipated to be highly sensitive to the edge plasma condition. The edge pedestal in ITER needs to be predicted from an integrated simulation of the necessary first-principles, multi-scale physics codes. The mission of the SciDAC Fusion Simulation Project (FSP) Prototype Center for Plasma Edge Simulation (CPES) is to deliver such a code integration framework by (1) building new kinetic codes XGC0 and XGC1, which can simulate the edge pedestal buildup; (2) using and improving the existing MHD codes ELITE, M3D-OMP, M3D-MPP and NIMROD, for study of large-scale edge instabilities called Edge Localized Modes (ELMs); and (3) integrating the codes into a framework using cutting-edge computer science technology. Collaborative effort among physics, computer science, and applied mathematics within CPES has created the first working version of the End-to-end Framework for Fusion Integrated Simulation (EFFIS), which can be used to study the pedestal-ELM cycles

    Effects of dietary Na+ deprivation on epithelial Na+ channel (ENaC), BDNF, and TrkB mRNA expression in the rat tongue

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In rodents, dietary Na<sup>+ </sup>deprivation reduces gustatory responses of primary taste fibers and central taste neurons to lingual Na<sup>+ </sup>stimulation. However, in the rat taste bud cells Na<sup>+ </sup>deprivation increases the number of amiloride sensitive epithelial Na<sup>+ </sup>channels (ENaC), which are considered as the "receptor" of the Na<sup>+ </sup>component of salt taste. To explore the mechanisms, the expression of the three ENaC subunits (α, β and γ) in taste buds were observed from rats fed with diets containing either 0.03% (Na<sup>+ </sup>deprivation) or 1% (control) NaCl for 15 days, by using <it>in situ </it>hybridization and real-time quantitative RT-PCR (qRT-PCR). Since BDNF/TrkB signaling is involved in the neural innervation of taste buds, the effects of Na<sup>+ </sup>deprivation on BDNF and its receptor TrkB expression in the rat taste buds were also examined.</p> <p>Results</p> <p><it>In situ </it>hybridization analysis showed that all three ENaC subunit mRNAs were found in the rat fungiform taste buds and lingual epithelia, but in the vallate and foliate taste buds, only α ENaC mRNA was easily detected, while β and γ ENaC mRNAs were much less than those in the fungiform taste buds. Between control and low Na<sup>+ </sup>fed animals, the numbers of taste bud cells expressing α, β and γ ENaC subunits were not significantly different in the fungiform, vallate and foliate taste buds, respectively. Similarly, qRT-PCR also indicated that Na<sup>+ </sup>deprivation had no effect on any ENaC subunit expression in the three types of taste buds. However, Na<sup>+ </sup>deprivation reduced BDNF mRNA expression by 50% in the fungiform taste buds, but not in the vallate and foliate taste buds. The expression of TrkB was not different between control and Na<sup>+ </sup>deprived rats, irrespective of the taste papillae type.</p> <p>Conclusion</p> <p>The findings demonstrate that dietary Na<sup>+ </sup>deprivation does not change ENaC mRNA expression in rat taste buds, but reduces BDNF mRNA expression in the fungiform taste buds. Given the roles of BDNF in survival of cells and target innervation, our results suggest that dietary Na<sup>+ </sup>deprivation might lead to a loss of gustatory innervation in the mouse fungiform taste buds.</p

    Adenosine A2A receptors modulate BDNF both in normal conditions and in experimental models of Huntington’s disease

    Get PDF
    Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, enhances synaptic transmission and regulates neuronal proliferation and survival. Functional interactions between adenosine A2A receptors (A2ARs) and BDNF have been recently reported. In this article, we report some recent findings from our group showing that A2ARs regulate both BDNF functions and levels in the brain. Whereas BDNF (10 ng/ml) increased the slope of excitatory postsynaptic field potentials (fEPSPs) in hippocampal slices from wild-type (WT) mice, it was completely ineffective in slices taken from A2AR knock-out (KO) mice. Furthermore, enzyme immunoassay studies showed a significant reduction in hippocampal BDNF levels in A2AR KO vs. WT mice. Having found an even marked reduction in the striatum of A2AR KO mice, and as both BDNF and A2ARs have been implicated in the pathogenesis of Huntington’s disease (HD), an inherited striatal neurodegenerative disease, we then evaluated whether the pharmacological blockade of A2ARs could influence striatal levels of BDNF in an experimental model of HD-like striatal degeneration (quinolinic acid-lesioned rats) and in a transgenic mice model of HD (R6/2 mice). In both QA-lesioned rats and early symptomatic R6/2 mice (8 weeks), the systemic administration of the A2AR antagonist SCH58261 significantly reduced striatal BDNF levels. These results indicate that the presence and the tonic activation of A2ARs are necessary to allow BDNF-induced potentiation of synaptic transmission and to sustain a normal BDNF tone. The possible functional consequences of reducing striatal BDNF levels in HD models need further investigation
    corecore