268 research outputs found

    On the Codimension Sequence of G-Simple Algebras

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    In the 80's, Regev, using results of Formanek, Procesi and Razmyslov in invariant theory and Hilbert series', determined asymptotically the codimension sequence of mXm matrices over an algebraically closed field of characteristic zero. Inspired by Regev's ideas, we found that the asymptotics of cnG(A)c_{n}^{G}(A), the G graded codimension sequence of a finite dimensional G simple algebra A, is equal to αn1dim(Ae)2(dim(A)n\alpha n^{\frac{1-\dim(A_{e})}{2}}(\dim(A)^{n} (this was conjectured by E.Aljadeff, D.Haile and M. Natapov), where \alpha is not yet determined number. Moreover, in the case where A is the algebra of mXm matrices with an arbitrary elementary G-grading we also manged to calculate \alpha

    Implementing Reinforcement Learning Datacenter Congestion Control in NVIDIA NICs

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    As communication protocols evolve, datacenter network utilization increases. As a result, congestion is more frequent, causing higher latency and packet loss. Combined with the increasing complexity of workloads, manual design of congestion control (CC) algorithms becomes extremely difficult. This calls for the development of AI approaches to replace the human effort. Unfortunately, it is currently not possible to deploy AI models on network devices due to their limited computational capabilities. Here, we offer a solution to this problem by building a computationally-light solution based on a recent reinforcement learning CC algorithm [arXiv:2207.02295]. We reduce the inference time of RL-CC by x500 by distilling its complex neural network into decision trees. This transformation enables real-time inference within the μ\mu-sec decision-time requirement, with a negligible effect on quality. We deploy the transformed policy on NVIDIA NICs in a live cluster. Compared to popular CC algorithms used in production, RL-CC is the only method that performs well on all benchmarks tested over a large range of number of flows. It balances multiple metrics simultaneously: bandwidth, latency, and packet drops. These results suggest that data-driven methods for CC are feasible, challenging the prior belief that handcrafted heuristics are necessary to achieve optimal performance

    DiProDB: a database for dinucleotide properties

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    DiProDB (http://diprodb.fli-leibniz.de) is a database of conformational and thermodynamic dinucleotide properties. It includes datasets both for DNA and RNA, as well as for single and double strands. The data have been shown to be important for understanding different aspects of nucleic acid structure and function, and they can also be used for encoding nucleic acid sequences. The database is intended to facilitate further applications of dinucleotide properties. A number of property datasets is highly correlated. Therefore, the database comes with a correlation analysis facility. Authors having determined new sets of dinucleotide property values are invited to submit these data to DiProDB

    Relational experiences of people seeking help and assessment for subjective cognitive concern and memory loss

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    Objective: To understand the experience of people who seek help for subjective cognitive concern and memory loss, including people not referred for further assessment. To understand the patients’ perspective of the medical process of receiving a cognitive assessment. This work is situated within the context of policy priorities for dementia diagnosis. Methods: Participants with and without dementia were recruited through NHS trusts and community organisations in four regional areas in England. Data were collected using longitudinal qualitative interviews. Transcript data were thematically analysed. Results: Sample of 41 people (mean 75 years, 25 dementia diagnoses). Interpretative thematic analyses focused on the presence or absence of trust in relational experiences. There were three transition points where trust could be specifically developed or undermined: 1) deciding to seek help; 2) healthcare practitioners’ response to help-seeking; 3) process and outcome of assessment. Triggers for help-seeking for subjective cognitive concern were being prompted by family and knowing a relative with dementia. When participants perceived healthcare practitioners’ behaviour as dismissive, they had less trust in the outcome of the healthcare encounter. Misunderstandings and absence of trust in assessment processes led to participants stating they did not fully agree with the outcomes of the assessment. Conclusions: Healthcare practitioners have an important role in supporting people with subjective cognitive concern ensuring patients have trust in assessment outcomes. Where the validity of the assessment process is seen as ambiguous, people can be left dealing with uncertainty, rather than being clear about ways they can manage their condition, situation or status

    Perceptions of the risks and benefits of Internet access and use by people with intellectual disabilities

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    This is an accepted manuscript of an article published by Wiley in British Journal of Learning Disabilities on 15 July 2016, available online: https://doi.org/10.1111/bld.12170 The accepted version of the publication may differ from the final published version.Accessible summary Both good and bad things can happen when people use the Internet, and people with learning disabilities are not using the Internet as much as other people. Worry about the bad things that can happen online might be one reason people with learning disabilities are not supported to access the Internet as much as other people. We wanted to find out what people without learning disabilities believe about these good and bad things for people with learning disabilities. We wanted to find this out because the way people without disabilities think about the good and bad things online might affect how people with learning disabilities are treated. We found out that people without learning disabilities think that both the good and bad things are more likely to happen to people with learning disabilities when they use the Internet. Abstract Background: Information and communication technologies, with the Internet at the forefront, have the potential to enhance the knowledge, service, employment, development and social interactional opportunities available to people with intellectual disabilities. Despite this, people with intellectual disabilities are not accessing the Internet to the same degree as people without intellectual disabilities. Issues of safety, risk and protection online for people with intellectual disabilities have yet to be adequately investigated, and these currently serve as reasons given for hindering people from gaining online access. Materials and Method: This survey aimed to gauge the views people without intellectual disabilities have of risks and benefits of using the Internet for themselves and for people with intellectual disabilities and to compare self-ratings of risk and benefits to ratings for people with intellectual disabilities. Results: The survey findings indicate that, with only a small number of exceptions, both the risks and benefits of being online were believed to be greater for people with intellectual disabilities compared with those without intellectual disabilities. Greater use of the Internet was associated with increased perception of benefits to being online for both people with intellectual disabilities and for participants. Conclusions: Perceptions of increased benefits suggest more needs to be performed to improve online access whilst a perception of increased risk may help to explain the reduced inclusion of people with intellectual disabilities in the online world

    Assessment of the influence of using green tea waste and fish waste as soil amendments for biosolarization on the growth of lettuce (Lactuca sativa L. var. ramosa Hort.)

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    IntroductionSafe and efficient treatment of organic waste is crucial to developing a sustainable food system around the world. Soil biosolarization (SBS) is a soil treatment technique that can use organic solid wastes to treat the soil in a way that is alternative to the use of chemical fumigants to improve soil fertility in agriculture.MethodsIn this study, two types of organic food wastes, green tea waste (GTW) and fish waste (FW), were evaluated for the feasibility of being applied as soil amendments within simulations of high-temperature cycle SBS. The evaluation was conducted by execution of three groups of measurements: gas and organic volatile emission profile, residual soil phytotoxicity and weed suppression, and cultivar growth (Lactuca sativa L. var. ramosa Hort.).Results and DiscussionGreen tea waste contributed to elevated levels of soil respiration and the evolution of signature volatile organic compounds during the simulated SBS. In the soil amended with green tea waste and then undergoing SBS the phyto compatibility was restored after residual phytotoxicity dissipation and a complete weed suppression was achieved. By using an application rate of 2.5% (w/w, mass fraction of green tea waste in total soil-waste mixture) green tea waste cultivar growth comparable to that of the non-treated soil (NTS) group was attained, with a more efficient nitrogen utilization and higher residual soil nitrogen content enabling the improvement of the continuous cropping system. FW at 1% (w/w, mass fraction of FW in total soil-waste mixture) promoted cultivar growth despite the significant reduction of the nitrogen (p value=0.02) and phosphorus (p value=0.03) contents in the cultivar leaves. A significant increase of the sodium content together with an increase of iron and chromium, which exceeded the permissible limit, were observed. These results provide new information about amendment selection for the SBS process

    Promoter prediction and annotation of microbial genomes based on DNA sequence and structural responses to superhelical stress

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    BACKGROUND: In our previous studies, we found that the sites in prokaryotic genomes which are most susceptible to duplex destabilization under the negative superhelical stresses that occur in vivo are statistically highly significantly associated with intergenic regions that are known or inferred to contain promoters. In this report we investigate how this structural property, either alone or together with other structural and sequence attributes, may be used to search prokaryotic genomes for promoters. RESULTS: We show that the propensity for stress-induced DNA duplex destabilization (SIDD) is closely associated with specific promoter regions. The extent of destabilization in promoter-containing regions is found to be bimodally distributed. When compared with DNA curvature, deformability, thermostability or sequence motif scores within the -10 region, SIDD is found to be the most informative DNA property regarding promoter locations in the E. coli K12 genome. SIDD properties alone perform better at detecting promoter regions than other programs trained on this genome. Because this approach has a very low false positive rate, it can be used to predict with high confidence the subset of promoters that are strongly destabilized. When SIDD properties are combined with -10 motif scores in a linear classification function, they predict promoter regions with better than 80% accuracy. When these methods were tested with promoter and non-promoter sequences from Bacillus subtilis, they achieved similar or higher accuracies. We also present a strictly SIDD-based predictor for annotating promoter sequences in complete microbial genomes. CONCLUSION: In this report we show that the propensity to undergo stress-induced duplex destabilization (SIDD) is a distinctive structural attribute of many prokaryotic promoter sequences. We have developed methods to identify promoter sequences in prokaryotic genomes that use SIDD either as a sole predictor or in combination with other DNA structural and sequence properties. Although these methods cannot predict all the promoter-containing regions in a genome, they do find large sets of potential regions that have high probabilities of being true positives. This approach could be especially valuable for annotating those genomes about which there is limited experimental data
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