448 research outputs found

    Truthful Online Scheduling with Commitments

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    We study online mechanisms for preemptive scheduling with deadlines, with the goal of maximizing the total value of completed jobs. This problem is fundamental to deadline-aware cloud scheduling, but there are strong lower bounds even for the algorithmic problem without incentive constraints. However, these lower bounds can be circumvented under the natural assumption of deadline slackness, i.e., that there is a guaranteed lower bound s>1s > 1 on the ratio between a job's size and the time window in which it can be executed. In this paper, we construct a truthful scheduling mechanism with a constant competitive ratio, given slackness s>1s > 1. Furthermore, we show that if ss is large enough then we can construct a mechanism that also satisfies a commitment property: it can be determined whether or not a job will finish, and the requisite payment if so, well in advance of each job's deadline. This is notable because, in practice, users with strict deadlines may find it unacceptable to discover only very close to their deadline that their job has been rejected

    Silicon-etalon fiber-optic temperature sensor

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    A temperature sensor is described which consists of a silicon etalon that is sputtered directly onto the end of an optical fiber. A two-layer protective cap structure is used to improve the sensor's long-term stability. The sensor's output is wavelength encoded to provide a high degree of immunity from cable and connector effects. This sensor is extremely compact and potentially inexpensive

    Rainbow: Combining Improvements in Deep Reinforcement Learning

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    The deep reinforcement learning community has made several independent improvements to the DQN algorithm. However, it is unclear which of these extensions are complementary and can be fruitfully combined. This paper examines six extensions to the DQN algorithm and empirically studies their combination. Our experiments show that the combination provides state-of-the-art performance on the Atari 2600 benchmark, both in terms of data efficiency and final performance. We also provide results from a detailed ablation study that shows the contribution of each component to overall performance.Comment: Under review as a conference paper at AAAI 201

    Vocal Communication Within a Forest Bird Community

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    This thesis takes a community approach to investigate the acoustics of forest birds in Zealandia sanctuary, Wellington. Initially, the annual changes in vocalisation output of 16 study species and their possible effect on bird conspicuousness were described. Environmental factors that may shape these avian vocalisations were addressed though invoking two key hypotheses, the acoustic adaptation hypothesis, and the acoustic niche hypothesis. In addition, the songs of selected species are investigated: the role of song harmonics in the native North Island saddleback, Philesturnus rufusater, and their role in ranging, change in song dialect through time and space in the introduced song thrush, Turdus philomelos, and temporal change in the song of the native grey warbler, Greygone igata. Vocal activity of the study species varied seasonally, affecting their detectability in bird counts. Some species were mostly first heard rather than seen and viceversa. The results lend support to the acoustic niche hypothesis in that vocalisations within the forest bird community appear to have evolved towards divergence, with native species’ vocalisations being more dispersed within the community acoustic space than those of the introduced species. However, all species concentrated their energy within relatively narrow frequency bands, supporting the predictions of the acoustic adaptation hypothesis. Adaptation to different transmission properties associated with different singing elevations or physiological parameters such as body weight may have an effect on shaping such bird vocalisations. Forests provide a complex acoustic space for sound transmission and a “sound window” may not be a constant property of a given forest. The study revealed that a prominent sound window persists in the lower frequency range that is less affected by habitat. Some high frequencies may have similar average attenuation values to those of low frequency, however, with greater fluctuation in attenuation. Ground effect is a further factor in determining how well different frequency ranges transmit and birds may use acoustic characteristics of their habitat to enhance their signal. Harmonics in North Island saddleback chatter song were found to play a potential role in ranging (estimating the distance of signaller), for playback songs with more relative energy within higher harmonics were evidently perceived as coming from a nearby individual. The repertoire size of the song thrush population studied in Zealandia has apparently evolved to become larger and more varied than the source population of song thrushes in the UK, with more syllables delivered with less repetition than the UK song recordings examined. Over a period of 7 years, syllables in grey warbler song have shifted to a higher frequency, but there was no difference in the temporal structure of the song. Habitat effect, competition on the acoustic signal from reintroduced birds and ambient noise level are considered as possible casual factors

    A review of the relationship between proinflammatory cytokines and major depressive disorder.

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    BACKGROUND: Determining etiological factors and reviewing advances in diagnostic modalities sensitive and specific to Major Depressive Disorder (MDD) is of importance in its evaluation and treatment. The inflammatory hypothesis is one of the most prevalent topics concerning MDD and may provide insight into the pathogenesis of depression, development of biomarkers, and ultimately production of more effective depression therapies. METHOD: We reviewed several studies to evaluate contemporary concepts concerning proinflammatory cytokines and their relationship to various depressive disorders, the use of anti-inflammatory therapies in MDD treatment, and the application of neuroimaging in conjunction with cytokine profiles from both plasma and CSF as possible diagnostic tools. RESULTS: Proinflammatory cytokines in both plasma and CSF have been found to influence the progression and severity of depressive disorders in different populations. Studies have shown elevated serum levels of IL-1, IL-6, TNF-α, CRP, and MCP-1 in depressed patients, but have presented mixed results with IL-8 serum levels, and with IL-6 and MCP-1 CSF levels. Anti-inflammatory treatment of MDD may have adjuvant properties with current depression medications. MRI and NIRS neuroimaging confirm neurological abnormalities in the presence of elevated proinflammatory cytokines in depressed or stressed patients. LIMITATIONS: Heterogeneity of MDD and limited CSF cytokine research complicate the study of MDD pathogenesis. CONCLUSION: There is significant evidence that inflammatory processes influence the development and progression of MDD. Future studies with larger arrays of cytokine profiles aided by neuroimaging may provide more sensitive and specific modes of diagnostics in determining MDD etiology and provide guidance in individual therapies

    Pre-Treatment Inflamed Tumor Immune Microenvironment Is Associated With Folfirinox Response in Pancreatic Cancer

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    INTRODUCTION: Pancreatic adenocarcinoma (PDAC) is an aggressive tumor with limited response to both chemotherapy and immunotherapy. Pre-treatment tumor features within the tumor immune microenvironment (TiME) may influence treatment response. We hypothesized that the pre-treatment TiME composition differs between metastatic and primary lesions and would be associated with response to modified FOLFIRINOX (mFFX) or gemcitabine-based (Gem-based) therapy. METHODS: Using RNAseq data from a cohort of treatment-naïve, advanced PDAC patients in the COMPASS trial, differential gene expression analysis of key immunomodulatory genes in were analyzed based on multiple parameters including tumor site, response to mFFX, and response to Gem-based treatment. The relative proportions of immune cell infiltration were defined using CIBERSORTx and Dirichlet regression. RESULTS: 145 samples were included in the analysis; 83 received mFFX, 62 received Gem-based therapy. Metastatic liver samples had both increased macrophage (1.2 times more, p \u3c 0.05) and increased eosinophil infiltration (1.4 times more, p \u3c 0.05) compared to primary lesion samples. Further analysis of the specific macrophage phenotypes revealed an increased M2 macrophage fraction in the liver samples. The pre-treatment CD8 T-cell, dendritic cell, and neutrophil infiltration of metastatic samples were associated with therapy response to mFFX (p \u3c 0.05), while mast cell infiltration was associated with response to Gem-based therapy (p \u3c 0.05). Multiple immunoinhibitory genes such as ADORA2A, CSF1R, KDR/VEGFR2, LAG3, PDCD1LG2, and TGFB1 and immunostimulatory genes including C10orf54, CXCL12, and TNFSF14/LIGHT were significantly associated with worse survival in patients who received mFFX (p = 0.01). There were no immunomodulatory genes associated with survival in the Gem-based cohort. DISCUSSION: Our evidence implies that essential differences in the PDAC TiME exist between primary and metastatic tumors and an inflamed pretreatment TiME is associated with mFFX response. Defining components of the PDAC TiME that influence therapy response will provide opportunities for targeted therapeutic strategies that may need to be accounted for in designing personalized therapy to improve outcomes

    Translational and Oncologic Significance of Tertiary Lymphoid Structures in Pancreatic Adenocarcinoma

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    Pancreatic adenocarcinoma (PDAC) is an aggressive tumor with poor survival and limited treatment options. PDAC resistance to immunotherapeutic strategies is multifactorial, but partially owed to an immunosuppressive tumor immune microenvironment (TiME). However, the PDAC TiME is heterogeneous and harbors favorable tumor-infiltrating lymphocyte (TIL) populations. Tertiary lymphoid structures (TLS) are organized aggregates of immune cells that develop within non-lymphoid tissue under chronic inflammation in multiple contexts, including cancers. Our current understanding of their role within the PDAC TiME remains limited; TLS are complex structures with multiple anatomic features such as location, density, and maturity that may impact clinical outcomes such as survival and therapy response in PDAC. Similarly, our understanding of methods to manipulate TLS is an actively developing field of research. TLS may function as anti-tumoral immune niches that can be leveraged as a therapeutic strategy to potentiate both existing chemotherapeutic regimens and potentiate future immune-based therapeutic strategies to improve patient outcomes. This review seeks to cover anatomy, relevant features, immune effects, translational significance, and future directions of understanding TLS within the context of PDAC

    Syrian refugee labour and food insecurity in Middle Eastern agriculture during the early COVID-19 pandemic

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    Drawing on ethnographic data from the 2019 SyrianFoodFutures and 2020 From the FIELD projects, this article provides insights into the early effects of the COVID-19 pandemic on refugee labour in agriculture in Jordan, Turkey, Lebanon, Iraq, and Syria. In spring 2020, movement restrictions and supply chain disruptions caused displaced Syrian farmworkers to lose their jobs and experience increased food insecurity. We situate our findings in the context of host countries’ use of legal ambiguity for governing refugees, Middle Eastern agriculture’s reliance on migrant labour, and the region’s longstanding food insecurity. We conclude that formalising refugee labour is not enough to address exploitation

    Comparison of Efficacy and Ocular Surface Disease Index Score between Bimatoprost, Latanoprost, Travoprost, and Tafluprost in Glaucoma Patients

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    Aim. The purpose of this study is to evaluate and compare the efficacy of 4 prostaglandin analogues (PGAs) and to determine the incidence of ocular surface disease in newly diagnosed, primary open-angle glaucoma (POAG) patients started on one of those 4 PGAs: bimatoprost (benzalkonium chloride, BAK, 0.3 mg/mL), latanoprost (BAK 0.2 mg/mL), travoprost (polyquad), and tafluprost (BAK-free). Patients and Methods. In this single-center, open-label trial, 32 patients newly diagnosed with POAG were randomly started on one of the four PGAs. All patients underwent a complete ophthalmological exam at presentation and at 1, 3, and 6 months of follow-up. Dry eye disease (DED) was assessed using the original Ocular Surface Disease Index (OSDI) questionnaire, in order to evaluate the impact of the drops on the quality of life of patients. Results. The mean age was 60.06 years ± 11.76. All four drugs equally and significantly reduced the intraocular pressure (IOP) with respect to the baseline IOP. There was a trend for a slightly greater reduction of IOP with bimatoprost, but the difference was not found to be statistically significant when compared to other PGAs. OSDI scores were significantly superior for travoprost (10.68 ± 5.73) compared to the other three drugs (p<0.05). Latanoprost caused the most significant eyelash growth and iris discoloration. Conjunctival hyperemia and superficial keratitis occurrence were similar in the four groups. Conclusion. All prostaglandin analogues equally and significantly reduce the IOP in patients with POAG. According to the results of the OSDI score, latanoprost seems to be the least tolerated among the four drugs

    Prevalence of pre-eclampsia in women in the Middle East: a scoping review

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    Hypertensive disorders of pregnancy are the second most common cause of maternal deaths worldwide. Metabolic syndrome is recognized as one of the risk factors for pre-eclampsia. A recent study revealed a high prevalence of metabolic syndrome in the United Arab Emirates (UAE), particularly amongst Emirati women compared with global estimates. This finding raises the possibility that the prevalence of pre-eclampsia in the region may also be higher as research is increasingly demonstrating an association between pre-eclampsia and metabolic syndrome. We therefore conducted this scoping review of the literature to investigate the nature and extent of studies evaluating the prevalence of pre-eclampsia within the Middle East region to enable subsequent comparison of these findings with the global burden of pre-eclampsia, objectively identify gaps in the literature and inform the design of future studies to address these gaps. PubMed and Scopus were used to extract studies published over the last 20 years (2003–2023). The search terms used included (“Pre-eclampsia” AND “Prevalence”) OR (“Hypertension in pregnancy” AND “Prevalence”) OR (“Pregnancy” AND “Pre-eclampsia”) OR (“Pre-eclampsia” AND “Epidemiology”). We limited our studies to those from the Middle East (ME). A total of 556 relevant articles were identified following which 11 were shortlisted for review. There were four studies from Iran, two from Saudi Arabia, two from Qatar, one from Jordan, and one from Bahrain. The remaining study included 29 countries from Africa, Asia, Latin America, and the Middle East of which data from Jordan, Lebanon, the Occupied Palestinian Territory, and Qatar were included. There were four retrospective, two cross-sectional, and two cohort studies, one prospective study, one meta-analysis, and one descriptive-analytical study. The prevalence of pre-eclampsia in the studies ranged from 0.17 to 5%. We did not find any study investigating the prevalence of pre-eclampsia in the United Arab Emirates. Based on our findings, we conclude that there is a significant scarcity of research in this area, especially within the Middle East, and notably an absence of studies specifically pertaining to the UAE. Consequently, we assert that there is a pressing requirement for additional research to evaluate the prevalence of pre-eclampsia in the region
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