Security inspection and testing require experts in security who think like an attacker. Security experts need to know code locations on which to focus their testing and inspection efforts. Since ...vulnerabilities are rare occurrences, locating vulnerable code locations can be a challenging task. We investigated whether software metrics obtained from source code and development history are discriminative and predictive of vulnerable code locations. If so, security experts can use this prediction to prioritize security inspection and testing efforts. The metrics we investigated fall into three categories: complexity, code churn, and developer activity metrics. We performed two empirical case studies on large, widely used open-source projects: the Mozilla Firefox web browser and the Red Hat Enterprise Linux kernel. The results indicate that 24 of the 28 metrics collected are discriminative of vulnerabilities for both projects. The models using all three types of metrics together predicted over 80 percent of the known vulnerable files with less than 25 percent false positives for both projects. Compared to a random selection of files for inspection and testing, these models would have reduced the number of files and the number of lines of code to inspect or test by over 71 and 28 percent, respectively, for both projects.
To date, the radial velocity (RV) method has been one of the most productive techniques for detecting and confirming extrasolar planetary candidates. Unfortunately, stellar activity can induce RV ...variations which can drown out or even mimic planetary signals – and it is notoriously difficult to model and thus mitigate the effects of these activity-induced nuisance signals. This is expected to be a major obstacle to using next-generation spectrographs to detect lower mass planets, planets with longer periods, and planets around more active stars. Enter Gaussian processes (GPs) which, we note, have a number of attractive features that make them very well suited to disentangling stellar activity signals from planetary signals. We present here a GP framework we developed to model RV time series jointly with ancillary activity indicators (e.g. bisector velocity spans, line widths, chromospheric activity indices), allowing the activity component of RV time series to be constrained and disentangled from e.g. planetary components. We discuss the mathematical details of our GP framework, and present results illustrating its encouraging performance on both synthetic and real RV data sets, including the publicly available Alpha Centauri B data set.
The microbial response to summer desiccation reflects adaptation strategies, setting the stage for a large rainfall-induced soil CO2 pulse upon rewetting, an important component of the ecosystem ...carbon budget. In three California annual grasslands, the present (DNA-based) and potentially active (RNA-based) soil bacterial and fungal communities were tracked over a summer season and in response to controlled rewetting of intact soil cores. Phylogenetic marker genes for bacterial (16S) and fungal (28S) RNA and DNA were sequenced, and the abundances of these genes and transcripts were measured. Although bacterial community composition differed among sites, all sites shared a similar response pattern of the present and potentially active bacterial community to dry-down and wet-up. In contrast, the fungal community was not detectably different among sites, and was largely unaffected by dry-down, showing marked resistance to dessication. The potentially active bacterial community changed significantly as summer dry-down progressed, then returned to pre-dry-down composition within several hours of rewetting, displaying spectacular resilience. Upon rewetting, transcript copies of bacterial rpoB genes increased consistently, reflecting rapid activity resumption. Acidobacteria and Actinobacteria were the most abundant phyla present and potentially active, and showed the largest changes in relative abundance. The relative increase (Actinobacteria) and decrease (Acidobacteria) with dry-down, and the reverse responses to rewetting reflected a differential response, which was conserved at the phylum level and consistent across sites. These contrasting desiccation-related bacterial life-strategies suggest that predicted changes in precipitation patterns may affect soil nutrient and carbon cycling by differentially impacting activity patterns of microbial communities.
The study explored the immediate impact of internet exposure on the mood and psychological states of internet addicts and low internet-users. Participants were given a battery of psychological tests ...to explore levels of internet addiction, mood, anxiety, depression, schizotypy, and autism traits. They were then given exposure to the internet for 15 min, and re-tested for mood and current anxiety. Internet addiction was associated with long-standing depression, impulsive nonconformity, and autism traits. High internet-users also showed a pronounced decrease in mood following internet use compared to the low internet-users. The immediate negative impact of exposure to the internet on the mood of internet addicts may contribute to increased usage by those individuals attempting to reduce their low mood by re-engaging rapidly in internet use.
Autophagy is a cell-protective and degradative process that recycles damaged and long-lived cellular components. Cancer cells are thought to take advantage of autophagy to help them to cope with the ...stress of tumorigenesis; thus targeting autophagy is an attractive therapeutic approach. However, there are currently no specific inhibitors of autophagy. ULK1, a serine/threonine protein kinase, is essential for the initial stages of autophagy, and here we report that two compounds, MRT67307 and MRT68921, potently inhibit ULK1 and ULK2 in vitro and block autophagy in cells. Using a drug-resistant ULK1 mutant, we show that the autophagy-inhibiting capacity of the compounds is specifically through ULK1. ULK1 inhibition results in accumulation of stalled early autophagosomal structures, indicating a role for ULK1 in the maturation of autophagosomes as well as initiation.
Background: Autophagy is an intracellular lysosomal degradation pathway implicated in many diseases, but there are currently no specific autophagy inhibitors.
Results: Small molecule inhibition of ULK1, the upstream autophagy initiating kinase, blocks autophagosome initiation and maturation.
Conclusion: ULK1 plays a role in autophagosome maturation as well as initiation.
Significance: ULK1 can be targeted to block autophagy for disease therapy.
Canonical Notch signaling is initiated by γ-secretase-mediated cleavage of the Notch receptor, leading to the release of the active intra-cellular domain of Notch that migrates to the nucleus and ...interacts with RBP-Jκ, resulting in the activation of downstream target genes. While canonical Notch signaling is well known to play an active role in several steps during development as well in multiple cell fate decisions, recent evidence from both invertebrate and vertebrate systems indicates that non-canonical, RBP-Jκ-independent signaling is important in several cellular processes including oncogenesis and activation of T lymphocytes. These observations raise the possibility that, through an understanding of non-canonical Notch signaling, novel strategies for inhibiting Notch signaling may prove useful in the design of therapies targeted to block aberrant Notch activity. In this mini-review, we will examine the current data demonstrating a non-canonical role for Notch signaling in both cancer and the immune system and suggest a better understanding of non-canonical signaling may reveal novel strategies to block Notch signaling in disease.
A large soil CO2 pulse is associated with rewetting soils after the dry summer period under a Mediterranean-type climate, significantly contributing to grasslands' annual carbon budget. Rapid ...reactivation of soil heterotrophs and a pulse of available carbon are both required to fuel the CO2 pulse. Understanding of the effects of altered summer precipitation on the metabolic state of indigenous microorganisms may be important in predicting changes in carbon cycling. Here, we investigated the effects of extending winter rainfall into the normally dry summer period on soil microbial response to a controlled rewetting event, by following the present (DNA-based) and potentially active (rRNA-based) soil bacterial and fungal communities in intact soil cores (from a California annual grassland) previously subjected to three different precipitation patterns over 4 months (full summer dry season, extended wet season and absent dry season). Phylogenetic marker genes for bacteria and fungi were sequenced before and after rewetting, and the abundance of these genes and transcripts was measured. After having experienced markedly different antecedent water conditions, the potentially active bacterial communities showed a consistent wet-up response. We found a significant positive relation between the extent of change in the structure of the potentially active bacterial community and the magnitude of the CO2 pulse upon rewetting dry soils. We suggest that the duration of severe dry summer conditions characteristic of the Mediterranean climate is important in conditioning the response potential of the soil microbial community to wet-up as well as in framing the magnitude of the associated CO2 pulse.
The future of employment Frey, Carl Benedikt; Osborne, Michael A
Technological forecasting & social change,
2017, January 2017, 2017-01-00, 20170101, Letnik:
114, Številka:
January
Journal Article
Recenzirano
Odprti dostop
We examine how susceptible jobs are to computerisation. To assess this, we begin by implementing a novel methodology to estimate the probability of computerisation for 702 detailed occupations, using ...a Gaussian process classifier. Based on these estimates, we examine expected impacts of future computerisation on US labour market outcomes, with the primary objective of analysing the number of jobs at risk and the relationship between an occupations probability of computerisation, wages and educational attainment.
Variability is a problem for the scalability of semiconductor quantum devices. The parameter space is large, and the operating range is small. Our statistical tuning algorithm searches for specific ...electron transport features in gate-defined quantum dot devices with a gate voltage space of up to eight dimensions. Starting from the full range of each gate voltage, our machine learning algorithm can tune each device to optimal performance in a median time of under 70 minutes. This performance surpassed our best human benchmark (although both human and machine performance can be improved). The algorithm is approximately 180 times faster than an automated random search of the parameter space, and is suitable for different material systems and device architectures. Our results yield a quantitative measurement of device variability, from one device to another and after thermal cycling. Our machine learning algorithm can be extended to higher dimensions and other technologies.
Semiconductor nanocrystals or quantum dots (QDs) are highly photoluminescent materials with unique optical attributes that are being exploited in an ever‐increasing array of applications. However, ...the complex surface chemistry of these finite‐sized fluorophores gives rise to a number of photophysical phenomena that can complicate their use in imaging applications. Fluorescence intermittency (FI), photoluminescence enhancement (PLE) and spectral bluing are properties of QD emission that would appear, at first sight, detrimental to quantitative measurement. Fortunately, developments in rational QD synthesis and surface modification are promising to minimize the effects of these fluorescence instabilities, while applications that exploit them are now coming to the fore. We review recent experimental and theoretical studies of FI, PLE and bluing, highlighting the benefits, as well as complications, they bring to key applications.
Colourful Quantum Dots: The unique photoluminescent properties of semiconductor nanocrystals (see picture) offer new insights into the quantum nature of nanomaterials. Certain features of their photophysics can be detrimental to conventional imaging, but can also be exploited in novel ways. Understanding the photochemical life of the quantum dot is helping towards the control and utilization of their properties in existing and new applications.
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