1,467 research outputs found

    SonicJoin: fast, robust and worst-case optimal

    Get PDF
    The establishment of the AGM bound on the size of intermediate results of natural join queries has led to the development of several so-called worst-case join algorithms. These algorithms provably produce intermediate results that are (asymptotically) no larger than the final result of the join. The most notable ones are the Recursive Join, its successor, the Generic Join and the Leapfrog-Trie-Join. While algorithmically efficient, however, all of these algorithms require the availability of index structures that allow tuple lookups using the prefix of a key. Key-prefix-lookups in relational database systems are commonly supported by tree-based index structures since hash-based indices only support full-key lookups. In this paper, we study a wide variety of main-memory-oriented index structures that support key-prefix-lookups with a specific focus on supporting the Generic Join. Based on that study, we develop a novel, best-of-breed index structure called Sonic that combines the fast build and point lookup properties of hashtables with the prefix-lookups capabilities of trees and tries. To evaluate the performance of a variety of indices for worst-case optimal joins in a modern code-generating DBMS, we leveraged flexible, compile-time metaprogramming features to build a framework that creates highly efficient code, interweaving (at a microarchitectural level) a generic join implementation with any appropriate index structure. We demonstrate experimentally that in that framework, Sonic outperforms the fastest existing approaches by up to 2.5 times when supporting the Generic Join algorithm

    Exploration of the experience of living with chronic insomnia: A qualitative study

    Get PDF
    Background. Chronic insomnia is associated with consequential experience that may affect quality of life. Understanding such experience can be helpful in planning effective interventions for patients with chronic insomnia. Objective. The study aimed to describe and illuminate the experience of living with chronic insomnia. Method. The study was conducted using a descriptive phenomenology approach. Participants were selected purposefully from patients with chronic insomnia who had been referred to the sleep disorders research center at Kermanshah University of Medical Sciences in Iran in 2014. Data were gathered through in-depth unstructured interviews and analyzed according to the Colaizzi method by means of Husserlian phenomenology. Results. Two main themes were found in this study, from which five sub themes were constructed: first, an upset mind, with the subthemes of insomnia as an unpleasant experience and insomnia as a worrying experience; and second, an unwanted new lifestyle with treatment seeking behavior, a boring new daily routine and being overshadowed by depressed mood as the subthemes. Conclusion. The study identified the experience of living with chronic insomnia as a painful one with both mental and practical aspects. The experience also explains how mental engagement and practical outcomes of chronic insomnia may interfere with well-being and quality of life in sufferers. It is recommended that patients' experiences would be considered in assessment and treatment of chronic insomnia. Therefore, therapeutic interventions should pay attention to this area

    Hypothalamic-pituitary-gonadal activity in paradoxical and psychophysiological insomnia

    Get PDF
    Background: Although insomnia is a sex-dimorphic disorder, there is limited knowledge about the association between sex hormones and insomnia. In the present study, the level of hypothalamus-pituitary-gonadal (HPG) axis activity was investigated in patients with insomnia by measuring serum levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), 17α-Hydroxyprogesterone, testosterone, progesterone, estradiol, dehydroepiandrosterone sulfate, and sex hormone-binding globulin. Methods: Numbers of 19 patients; including 13 females (68.40) with paradox insomnia (32-53 years; 43.20 ± 6.40) and 17 patients; including 8 females (47.05) with psychophysiological insomnia (14-62 years; 38.40 ± 16.30) were recruited. Seventeen aged-matched normal sleeper consisted of 13 males (26-59 years; 40.70 ± 10) consisted of 13 males (76.50) were also recruited as control group. Insomnia was diagnosed by a sleep clinician according to the International Classification of Sleep Disorders-Second Edition criteria and an overnight polysomnography (PSG). A volume of 5 ml of venous blood samples were collected, prepared, and stored at 8 AM under standard condition. Serum levels of hormones were measured using enzyme-linked immunosorbent assay kits. Data were analyzed by Chi-square and ANCOVA. The associations between PSG and biochemical parameters were evaluated using multiple linear regression analysis. Results: There were no significant differences in all biochemical analyses between two insomnia subgroups (paradoxical and psychophysiological insomnia) and normal sleepers. Testosterone was positively related to maximum pulse transit time (PTT). Moreover, both LH and FSH were positively related to wake index and diastolic blood pressure. Conclusion: Although there were no significant differences in all HPG's hormones between groups, both LH and FSH were associated with wake index and diastolic blood pressure. Moreover, testosterone was positively related to PTT. © 2019 Journal of Medical Signals & Sensors

    Making a symbolic gesture: a qualitative examination of self-immolation in Iran

    Get PDF
    Self-immolation is one of the most dramatic methods of committing suicide. Some regions in Iran have a high prevalence of suicide by this method. This study aims to understand and explore the experience of self-immolated women in Iran. Twenty women have interviewed in the burns centers of three different cities immediately the following hospitalization due self-immolation, and the data was analyzed using conventional content analysis. The results were categorized in three main categories: Cultural background and preparing the stage, making a symbolic gesture and events of the day of the incident. Making a symbolic gesture consists of the critical elements of self-immolation, including the presence of significant others, dramatic presentation of misery, bringing an end to misfortune, proof of innocence, creating a sense of compassion or guilt and inspiration from similar cases. The social situation of women in Iran is contributing to self-immolation through feelings of anger and helplessnes

    Antisense epidermal growth factor receptor RNA transfection in human glioblastoma cells down-regulates telomerase activity and telomere length

    Get PDF
    Epidermal growth factor receptor is overexpressed and/or amplified in up to 50% of glioblastomas, suggesting an important role of this gene in glial tumorigenesis and progression. In the present study we demonstrated that epidermal growth factor receptor is involved in regulation of telomerase activity in glioblastoma. Antisense-epidermal growth factor receptor approach was used to inhibit epidermal growth factor receptor expression of glioblastoma U87MG cells. Telomerase activity in antisense-epidermal growth factor receptor cells decreased by up to 54 folds compared with control cells. Moreover, the telomere lengths of antisense-epidermal growth factor receptor cells were shortened. In addition, the tumorigenicity of antisense-epidermal growth factor receptor cells was significantly inhibited. Taken together, there were strong correlations between tumorigenicity and epidermal growth factor receptor expression levels, and between tumorigenicity and telomerase activity. These results provide evidence that epidermal growth factor receptor plays an important role in the regulation of telomerase activity of glioma cells. Our findings provide new insights into both the biological functions of epidermal growth factor receptor and the regulation of telomerase activity. The inhibition of telomerase activity triggered by antisense-epidermal growth factor receptor treatment may reflect yet another mechanism of antisense-epidermal growth factor receptor approach in tumour suppression

    The effect of acceptance and commitment therapy on insomnia and sleep quality: A systematic review

    Get PDF
    Background Acceptance and Commitment Therapy (ACT), as a type of behavioral therapy, attempts to respond to changes in people’s performance and their relationship to events. ACT can affect sleep quality by providing techniques to enhance the flexibility of patients’ thoughts, yet maintaining mindfullness. Therefore, for the first time, a systematic review on the effects of ACT on sleep quality has been conducted. Methods This systematic review was performed to determine the effect of ACT on insomnia and sleep quality. To collect articles, the PubMed, Web of Science (WOS), Cochrane library, Embase, Scopus, Science Direct, ProQuest, Mag Iran, Irandoc, and Google Scholar databases were searched, without a lower time-limit, and until April 2020. Results Related articles were derived from 9 research repositories, with no lower time-limit and until April 2020. After assessing 1409 collected studies, 278 repetitive studies were excluded. Moreover, following the primary and secondary evaluations of the remaining articles, 1112 other studies were removed, and finally a total of 19 intervention studies were included in the systematic review process. Within the remaining articles, a sample of 1577 people had been assessed for insomnia and sleep quality. Conclusion The results of this study indicate that ACT has a significant effect on primary and comorbid insomnia and sleep quality, and therefore, it can be used as an appropriate treatment method to control and improve insomnia

    EGFR Kinase Promotes Acquisition of Stem Cell-Like Properties: A Potential Therapeutic Target in Head and Neck Squamous Cell Carcinoma Stem Cells

    Get PDF
    Members of the EGFR/ErbB family of tyrosine kinases are found to be highly expressed and deregulated in many cancers, including head and neck squamous cell carcinoma (HNSCC). The ErbB family, including EGFR, has been demonstrated to play key roles in metastasis, tumorigenesis, cell proliferation, and drug resistance. Recently, these characteristics have been linked to a small subpopulation of cells classified as cancer stem cells (CSCs) which are believed to be responsible for tumor initiation and maintenance. In this study, we investigated the possible role of EGFR as a regulator of “stemness” in HNSCC cells. Activation of EGFR by the addition of EGF ligand or ectopic expression of EGFR in two established HNSCC cell lines (UMSCC-22B and HN-1) resulted in the induction of CD44, BMI-1, Oct-4, NANOG, CXCR4, and SDF-1. Activation of EGFR also resulted in increased tumorsphere formation, a characteristic ability of cancer stem cells. Conversely, treatment with the EGFR kinase inhibitor, Gefinitib (Iressa), resulted in decreased expression of the aforementioned genes, and loss of tumorsphere-forming ability. Similar trends were observed in a 99.9% CD44 positive stem cell culture derived from a fresh HNSCC tumor, confirming our findings for the cell lines. Additionally, we found that these putative cancer stem cells, when treated with Gefitinib, possessed a lower capacity to invade and became more sensitive to cisplatin-induced death in vitro. These results suggest that EGFR plays critical roles in the survival, maintenance, and function of cancer stem cells. Drugs that target EGFR, perhaps administered in combination with conventional chemotherapy, might be an effective treatment for HNSCC

    The Pixel Luminosity Telescope: a detector for luminosity measurement at CMS using silicon pixel sensors

    Get PDF
    The Pixel Luminosity Telescope is a silicon pixel detector dedicated to luminosity measurement at the CMS experiment at the LHC. It is located approximately 1.75 m from the interaction point and arranged into 16 “telescopes”, with eight telescopes installed around the beam pipe at either end of the detector and each telescope composed of three individual silicon sensor planes. The per-bunch instantaneous luminosity is measured by counting events where all three planes in the telescope register a hit, using a special readout at the full LHC bunch-crossing rate of 40 MHz. The full pixel information is read out at a lower rate and can be used to determine calibrations, corrections, and systematic uncertainties for the online and offline measurements. This paper details the commissioning, operational history, and performance of the detector during Run 2 (2015–18) of the LHC, as well as preparations for Run 3, which will begin in 2022
    corecore