2,269 research outputs found

    Densest Subgraph in Dynamic Graph Streams

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    In this paper, we consider the problem of approximating the densest subgraph in the dynamic graph stream model. In this model of computation, the input graph is defined by an arbitrary sequence of edge insertions and deletions and the goal is to analyze properties of the resulting graph given memory that is sub-linear in the size of the stream. We present a single-pass algorithm that returns a (1+ϵ)(1+\epsilon) approximation of the maximum density with high probability; the algorithm uses O(\epsilon^{-2} n \polylog n) space, processes each stream update in \polylog (n) time, and uses \poly(n) post-processing time where nn is the number of nodes. The space used by our algorithm matches the lower bound of Bahmani et al.~(PVLDB 2012) up to a poly-logarithmic factor for constant ϵ\epsilon. The best existing results for this problem were established recently by Bhattacharya et al.~(STOC 2015). They presented a (2+ϵ)(2+\epsilon) approximation algorithm using similar space and another algorithm that both processed each update and maintained a (4+ϵ)(4+\epsilon) approximation of the current maximum density in \polylog (n) time per-update.Comment: To appear in MFCS 201

    Bidirectional PageRank Estimation: From Average-Case to Worst-Case

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    We present a new algorithm for estimating the Personalized PageRank (PPR) between a source and target node on undirected graphs, with sublinear running-time guarantees over the worst-case choice of source and target nodes. Our work builds on a recent line of work on bidirectional estimators for PPR, which obtained sublinear running-time guarantees but in an average-case sense, for a uniformly random choice of target node. Crucially, we show how the reversibility of random walks on undirected networks can be exploited to convert average-case to worst-case guarantees. While past bidirectional methods combine forward random walks with reverse local pushes, our algorithm combines forward local pushes with reverse random walks. We also discuss how to modify our methods to estimate random-walk probabilities for any length distribution, thereby obtaining fast algorithms for estimating general graph diffusions, including the heat kernel, on undirected networks.Comment: Workshop on Algorithms and Models for the Web-Graph (WAW) 201

    The study of intensity and frequency of posttraumatic stress disorder (PTSD) resulting from war in Ilam city

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    Post-traumatic stress disorder (PTSD) is a set of a person's reactions to stresses which are beyond one's mental capacity and precedes a severe stress. The aim of this Research was to study the intensity and frequency of posttraumatic stress disorder (PTSD) resulting from war in Ilam city. This descriptive- analytic study was investigated the PTSD among the residents of Ilam city who were involved directly or indirectly in the war issues. The sample size was 5110 people chosen through cluster sampling technique. Data were analyzed through statistical methods such as K2 test, t-test, linear regression test, and variance analysis in SPSS software. The results of the study revealed that 26 of the cases who had residence background in Ilam city during Iraqi war against Iran suffered from mental disorder (PTSD). Most of these patients were married, illiterate, or primary educated people and mostly the young and middle aged housewives. The war-induced posttraumatic stress disorder has had negative effects on different aspects of Ilam city residents' health. Therefore, identifying the vulnerable groups to apply medical treatment seemed important and necessary

    The effect of most important medicinal plants on two importnt psychiatric disorders (anxiety and depression)-a review

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    Anxiety and depression are highly comorbid psychiatric conditions that the prevalence will be increased to the second greatest risk of morbidity, causing a significant socioeconomic burden. Due to side effects and destructive effects of some chemical drugs, many patients prefer herbal medicines to treat diseases. Although there are key review papers in the area of medicinal plants and psychiatry disorders, they have either covered the area in a relatively cursory manner or focused on a specific plant medicine. In the present study, we tried to present the effect of most important medicinal plants on two important highly comorbid psychiatric conditions-anxiety and depression

    Germplasm diversity of sunflower volatile terpenoid profiles across vegetative and reproductive organs

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    Received: September 4th, 2022 ; Accepted: December 4th, 2022 ; Published: December 24th, 2022 ; Corresponding author: [email protected] sunflower (Helianthus annuus) is the fourth most important oilseed crop globally and is known to have experienced multiple genetic bottlenecks during domestication and improvement. Homogenization of crop germplasm may limit breeding efforts to improve pest and pathogen resistance or optimize other biotic interactions like pollinator attraction. Such interactions are often strongly influenced by plant phytochemistry, especially volatile compounds like terpenoids. Here we use solid-phase microextraction gas chromatography mass spectrometry (SPME GC-MS) to evaluate volatile phytochemistry across leaves, involucral bracts, disc florets, and ray floret petals in a collection of twelve inbred lines selected to represent a cross-section of sunflower germplasm diversity. Results indicate considerable compositional diversity of volatiles among lines, though substantial reduction in total volatile abundance relative to wild H. annuus. From leaves and bracts to disc florets and petals, we observe a strong increase in the proportion of monoterpenoids relative to sesquiterpenoids accompanying the transition to reproductive structures, with consistently over 85% monoterpenoids in disc florets and petals. This pattern is driven by substantially higher production of monoterpenoids (especially alpha-pinene and sabinene) in reproductive structures. Sesquiterpenoid production is roughly similar across organs, and in leaves varies among lines from 21–55% of volatiles, dominated by cadinene-type sesquiterpenoids. This work suggests that the compositional diversity of volatile terpenoids within cultivated germplasm may be sufficient for many breeding applications, though for breeding increased volatile production the use of wild H. annuus and other wild Helianthus germplasm may be necessary

    A Review Study on the Effect of Iranian Herbal Medicines on Opioid Withdrawal Syndrome.

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    Addiction is a chronic and recurring disease that recurrence phenomenon is the most important challenge in treatment of this disease. Recent experiences have shown that synthetic drugs have undesirable side effects. Recent studies on medicinal plants have shown that they might be effective in treatment of different stages of addiction with lower side effects and costs. The aim of this study was to review the effects of medicinal plants in the treatment of morphine addiction in experimental animals. In this review article, by using keywords of morphine, withdrawal, and plants or herbal medicine in databases of indexing cites, desired articles were obtained since 1994. Inclusion criteria for selecting articles were the articles related to application of medicinal plants in decreasing symptoms resulting from morphine withdrawal were selected. Results of this study on experimental studies have shown that medicinal plants such as Trachyspermum copticum L and Melissa officinalis decrease the symptoms of withdrawal syndrome in a dose-dependent. Also, medicinal plants like Avena sativa, Hypericum perforatu, Passiflora incarnate, Valeriana officinalis, Satureja hortensis L, and Mentha piperita can have effects on behavior, emotions, and other problems of addicts, decreasing withdrawal symptoms. Results of this study showed that medicinal plants can be effective in controlling deprivation, decreasing dependency creation, and possibly DETOXIFICATION: of opioid addicts

    Identification of medicinal plants effective in infectious diseases in Urmia, northwest of Iran

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    Objective: To identify the medicinal plants effective in infectious diseases. Methods: Initially, we obtained a list of herbalists and traditional healers from Food and Drug Deputy. Direct observations and interviews as well as collection of herbarium specimens of indigenous medicinal plants effective in infectious diseases of urinary tract, reproductive, digestive, respiratory and skin systems were performed. This study was conducted through questionnaires and interviews; the questionnaires were distributed among traditional healers and simultaneous interviews were also run. The plants were herbariumized, herbarium specimens were authenticated, and their species were determined by using reliable flora and other sources. Finally, the data were input into Excel 2010 and analyses were performed. Results: Out of the studied plants, 35 native medicinal plants belonging to 17 families were effective in the treatment of various diseases and infections. In this study, the Lamiaceae family had the highest frequency of plants for the treatment of infections. Traditional healers of Urmia in 24% of cases used the leaves of medicinal herb to treat patients. In 68% of cases, they prescribed medicinal herbs in the boiled forms. Most medicinal herbs showed therapeutic effect on the digestive system. Conclusions: Traditional medicinal sources, valuable knowledge of traditional healers in Urmia, the scientific investigation of the effects of the herbs offered in this study and their effects in traditional medicine may provide a good source for new drugs in modern medicine

    A review on most important herbal and synthetic antihelmintic drugs

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    Parasites and parasitic diseases are widely spread in the world. Their adverse effects on health and social economic society cause tremendous public health problems. Parasitic infections in different ways (water, soil, food and vegetables) can affect humans and induce other complications such as gastrointestinal disorders, malnutrition, anemia and allergies and sometimes even life threatening. Medicinal plants are being widely used, either as a single drug or in combination with synthetic drugs. These medicinal plants are considered as a valuable source of unique natural products and drugs for development of medicines against various disorders and diseases. In this article the recently published papers about medicinal plants and parasites were reviewed, using scientific sites such as Medline, PubMed and Google Scholar. The used terms included: herbal medicine, medicinal plants, and antihelmintic drugs, antinematoda, anticestoda, antitrematoda. From the above collected literature it might be concluded that these plants are promising potential sources for preparation of new drugs or for pharmacological and therapeutic applications

    Sleep disturbances and psychological well-being among military medical doctors of the Swiss Armed Forces: study protocol, rationale and development of a cross-sectional and longitudinal interventional study.

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    BACKGROUND Compared to civilians and non-medical personnel, military medical doctors are at increased risk for sleep disturbances and impaired psychological well-being. Despite their responsibility and workload, no research has examined sleep disturbances and psychological well-being among the medical doctors (MDs) of the Swiss Armed Forces (SAF). Thus, the aims of the proposed study are (1) to conduct a cross-sectional study (labeled 'Survey-Study 1') of sleep disturbances and psychological well-being among MDs of the SAF; (2) to identify MDs who report sleep disturbances (insomnia severity index >8), along with low psychological well-being such as symptoms of depression, anxiety and stress, but also emotion regulation, concentration, social life, strengths and difficulties, and mental toughness both in the private/professional and military context and (3) to offer those MDs with sleep disturbances an evidence-based and standardized online interventional group program of cognitive behavioral therapy for insomnia (eCBTi) over a time lapse of 6 weeks (labeled 'Intervention-Study 2'). METHOD All MDs serving in the SAF (N = 480) will be contacted via the SAF-secured communication system to participate in a cross-sectional survey of sleep disturbances and psychological well-being ('Survey-Study 1'). Those who consent will be provided a link to a secure online survey that assesses sleep disturbances and psychological well-being (depression, anxiety, stress, coping), including current working conditions, job-related quality of life, mental toughness, social context, family/couple functioning, substance use, and physical activity patterns. Baseline data will be screened to identify those MDs who report sleep disturbances (insomnia severity index >8); they will be re-contacted, consented, and randomly assigned either to the eCBTi or the active control condition (ACC) ('Intervention-Study 2'). Individuals in the intervention condition will participate in an online standardized and evidence-based group intervention program of cognitive behavioral therapy for insomnia (eCBTi; once the week for six consecutive weeks; 60-70 min duration/session). Participants in the ACC will participate in an online group counseling (once the week for six consecutive weeks; 60-70 min duration/session), though, the ACC is not intended as a bona fide psychotherapeutic intervention. At the beginning of the intervention (baseline), at week 3, and at week 6 (post-intervention) participants complete a series of self-rating questionnaires as for the Survey-Study 1, though with additional questionnaires covering sleep-related cognitions, experiential avoidance, and dimensions of self-awareness. EXPECTED OUTCOMES Survey-Study 1: We expect to describe the prevalence rates of, and the associations between sleep disturbances (insomnia (sleep quality); sleep onset latency (SOL); awakenings after sleep onset (WASO)) and psychological well-being among MDs of the SAF; we further expect to identify specific dimensions of psychological well-being, which might be rather associated or non-associated with sleep disturbances.Intervention-Study 2: We expect several significant condition-by-time-interactions. Such that participants in the eCBTi will report significantly greater improvement in sleep disturbances, symptoms of depression, anxiety, stress reduction both at work and at home (family related stress), and an improvement in the overall quality of life as compared to the ACC over the period of the study. CONCLUSION The study offers the opportunity to understand the prevalence of sleep disturbances, including factors of psychological well-being among MDs of the SAF. Further, based on the results of the Intervention-Study 2, and if supported, eCBTi may be a promising method to address sleep disturbances and psychological well-being among the specific context of MDs in the SAF

    Sleep Disturbances and Psychological Well-Being Among Military Medical Doctors of the Swiss Armed Forces: Study Protocol, Rationale and Development of a Cross-Sectional and Longitudinal Interventional Study

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    Background: Compared to civilians and non-medical personnel, military medical doctors are at increased risk for sleep disturbances and impaired psychological well-being. Despite their responsibility and workload, no research has examined sleep disturbances and psychological well-being among the medical doctors (MDs) of the Swiss Armed Forces (SAF). Thus, the aims of the proposed study are (1) to conduct a cross-sectional study (labeled ‘Survey-Study 1’) of sleep disturbances and psychological well-being among MDs of the SAF; (2) to identify MDs who report sleep disturbances (insomnia severity index \u3e8), along with low psychological well-being such as symptoms of depression, anxiety and stress, but also emotion regulation, concentration, social life, strengths and difficulties, and mental toughness both in the private/professional and military context and (3) to offer those MDs with sleep disturbances an evidence-based and standardized online interventional group program of cognitive behavioral therapy for insomnia (eCBTi) over a time lapse of 6 weeks (labeled ‘Intervention-Study 2’). Method: All MDs serving in the SAF (N = 480) will be contacted via the SAF-secured communication system to participate in a cross-sectional survey of sleep disturbances and psychological well-being (‘Survey-Study 1’). Those who consent will be provided a link to a secure online survey that assesses sleep disturbances and psychological well-being (depression, anxiety, stress, coping), including current working conditions, job-related quality of life, mental toughness, social context, family/couple functioning, substance use, and physical activity patterns. Baseline data will be screened to identify those MDs who report sleep disturbances (insomnia severity index \u3e8); they will be re-contacted, consented, and randomly assigned either to the eCBTi or the active control condition (ACC) (‘Intervention-Study 2’). Individuals in the intervention condition will participate in an online standardized and evidence-based group intervention program of cognitive behavioral therapy for insomnia (eCBTi; once the week for six consecutive weeks; 60–70 min duration/session). Participants in the ACC will participate in an online group counseling (once the week for six consecutive weeks; 60–70 min duration/session), though, the ACC is not intended as a bona fide psychotherapeutic intervention. At the beginning of the intervention (baseline), at week 3, and at week 6 (post-intervention) participants complete a series of self-rating questionnaires as for the Survey-Study 1, though with additional questionnaires covering sleep-related cognitions, experiential avoidance, and dimensions of self-awareness. Expected outcomes: Survey-Study 1: We expect to describe the prevalence rates of, and the associations between sleep disturbances (insomnia (sleep quality); sleep onset latency (SOL); awakenings after sleep onset (WASO)) and psychological well-being among MDs of the SAF; we further expect to identify specific dimensions of psychological well-being, which might be rather associated or non-associated with sleep disturbances. Intervention-Study 2: We expect several significant condition-by-time-interactions. Such that participants in the eCBTi will report significantly greater improvement in sleep disturbances, symptoms of depression, anxiety, stress reduction both at work and at home (family related stress), and an improvement in the overall quality of life as compared to the ACC over the period of the study. Conclusion: The study offers the opportunity to understand the prevalence of sleep disturbances, including factors of psychological well-being among MDs of the SAF. Further, based on the results of the Intervention-Study 2, and if supported, eCBTi may be a promising method to address sleep disturbances and psychological well-being among the specific context of MDs in the SAF
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