189 research outputs found

    Dynamics of Postfire Aboveground Carbon in a Chronosequence of Chinese Boreal Larch Forests

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    Boreal forests store a large proportion of the global terrestrial carbon (C), while wildfire plays a crucial role in determining their C storage and dynamics. The aboveground C (AC) pool is an important component of forest C stocks. To quantify the turning point (transforming from C source to C sink) and recovery time of postfire AC, and assess how stand density affects the AC, 175 plots from eight stand age classes were surveyed as a chronosequence in the Great Xing\u27an Mountains of Northeast China. Linear and nonlinear regression analyses were conducted to describe postfire AC recovery patterns. The results showed that (1) postfire AC exhibited a skewed U‐shaped pattern with the turning point at approximately year 30, when the change rate of AC shifted from negative to positive, (2) it took more than 120 years for this forest ecosystem to recover 80% of AC in unburned old‐growth (200 years) stands, and (3) there was an overall positive relationship between AC and stand density over the entire range of stand age classes; and such relationship was stronger during the early‐ and late‐successional stages, but weaker (p \u3e 0.05) during the midsuccessional stage. Although boreal larch forests have been C sinks under historical fire free intervals, predicted increases in fire frequency could potentially shift it to a C source. Understanding postfire AC dynamics in boreal larch forests is central to predicting C cycling response to wildfire and provides a framework for assessing ecosystem resilience to disturbance in this region

    Novel study designs to investigate the placebo response

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    <p>Abstract</p> <p>Background</p> <p>Investigating the size and mechanisms of the placebo response in clinical trials have relied on experimental procedures that simulate the double-blind randomized placebo-controlled design. However, as the conventional design is thought to elucidate drug rather than placebo actions, different methodological procedures are needed for the placebo response.</p> <p>Methods</p> <p>We reviewed the respective literature for trials designs that may be used to elucidate the size of the placebo response and the mechanisms associated with it.</p> <p>Results</p> <p>In general, this can be done by either manipulation the information provided to the subjects, or by manipulation the timing of the drug applied. Two examples of each strategy are discussed: the "balanced placebo design" (BDP) and the "balanced cross-over design" (BCD) and their variants are based on false information, while the "hidden treatment" (HT) and the ""delayed response test" (DRT) are based on manipulating the time of drug action. Since most such approaches include deception or incomplete information of the subjects they are suitable for patient only with authorized deception.</p> <p>Conclusion</p> <p>Both manipulating the information provided to subjects (BDP, DCD) or manipulating the timing of drug application (HT, DRT) allows overcoming some of the restrictions of conventional drug trials in the assessment of the placebo response, but they are feasible mostly in healthy subjects for ethical reasons.</p

    Consistent superiority of selective serotonin reuptake inhibitors over placebo in reducing depressed mood in patients with major depression.

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    The recent questioning of the antidepressant effect of selective serotonin reuptake inhibitors (SSRIs) is partly based on the observation that approximately half of company-sponsored trials have failed to reveal a significant difference between active drug and placebo. Most of these have applied the Hamilton depression rating scale to assess symptom severity, the sum score for its 17 items (HDRS-17-sum) serving as effect parameter. In this study, we examined whether the negative outcomes of many SSRI trials may be partly caused by the use of this frequently questioned measure of response. We undertook patient-level post-hoc analyses of 18 industry-sponsored placebo-controlled trials regarding paroxetine, citalopram, sertraline or fluoxetine, and including in total 6669 adults with major depression, the aim being to assess what the outcome would have been if the single item depressed mood (rated 0-4) had been used as a measure of efficacy. In total, 32 drug-placebo comparisons were reassessed. While 18 out of 32 comparisons (56%) failed to separate active drug from placebo at week 6 with respect to reduction in HDRS-17-sum, only 3 out of 32 comparisons (9%) were negative when depressed mood was used as an effect parameter (

    ДИАГНОСТИКА БЕССИМПТОМНОЙ ИШЕМИЧЕСКОЙ БОЛЕЗНИ СЕРДЦА У БОЛЬНЫХ, КОТОРЫМ ПРЕДСТОЯТ РЕКОНСТРУКТИВНЫЕ ОПЕРАЦИИ НА АОРТЕ И МАГИСТРАЛЬНЫХ АРТЕРИЯХ НИЖНИХ КОНЕЧНОСТЕЙ

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    Goal of the study: working out procedure aimed at the diagnostics of painless myocardial ischemia in the patients expecting surgery on aorta and main arteries of lower limbs. Materials and methods. 72 patients with disorders of aorta and main arteries of lower limbs were enrolled into the study. Depending on factors of risk to develop cardiac vascular disorders as per Lee score they were divided into two groups. Group 1 (n = 38) included patients who had 2 and more risk factors in the pre-operative period, Group 2 included patients (n = 34) who had less than 2 risk factors. All of the patients had holter monitoring, stress echocardiography and coronary arteriography during pre-operative period. Results. The study showed the high efficiency of Lee score of cardiac-vascular complication risks. The patients who had 2 risk factors and more had hemodynamically significant lesions of coronary bed in 97.4% which was detected by coronary arteriography. In Group 2 painless myocardial ischemia was detected almost in 1/3 of patients, which later provided certain impact in the choice of surgical treatment strategy. Conclusions. The results proved low efficiency of holter monitoring in the patients suffering from multi-focal atherosclerosis and high efficiency of stress echocardiography. The latter should be mandatory included into the examination procedure of such patients regardless of the results of Lee score; and coronary arteriography is to be performed in case of 2 risk scores and more. Detection of painless myocardial ischemia can change the plan of surgical treatment and requires amending anesthesia tactics. Цель исследования: отработка алгоритма действий, направленного на диагностику бессимптомной ишемической болезни сердца (ИБС) у больных, готовящихся к оперативному вмешательству на аорте и магистральных артериях нижних конечностей. Материалы и методы. В исследование включено 72 пациента с патологией аорты и магистральных артерий нижних конечностей. В зависимости от наличия факторов риска развития сердечно-сосудистых осложнений по Lee они были разделены на две группы. В 1-ю группу (n = 38) вошли пациенты, у которых в предоперационном периоде было определено 2 фактора риска и более, 2-ю группу составили пациенты (n = 34), у которых было менее 2 факторов риска. В предоперационном периоде всем им выполняли холтеровское мониторирование, стресс-эхокардиографию, коронарографию. Результаты. Исследование показало высокую эффективность применения шкалы риска сердечно-сосудистых осложнений по Lee. У пациентов, имевших 2 фактора риска и более, в 97,4% случаев при коронарографии были верифицированы гемодинамически значимые поражения венечного русла. Во 2-й группе атипичную ИБС удалось выявить почти у 1 /3 пациентов, что в дальнейшем также повлияло на выбор стратегии хирургического лечения. Выводы. Результаты показали низкую значимость методики холтеровского мониторирования у пациентов с мультифокальным атеросклерозом и высокую значимость стресс-эхокардиографии. Последнюю следует обязательно включать в алгоритм обследования таких больных независимо от результатов оценки риска осложнений по Lee, а коронарографию – при риске в 2 балла и более. Выявление бессимптомной формы ИБС может изменить план хирургического лечения и диктует внесение корректировок в тактику анестезии.

    Geospatial data analysis in Russia’s geoweb

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    The chapter examines the role of geospatial data in Russia’s online ecosystem. Facilitated by the rise of geographic information systems and user-generated content, the distribution of geospatial data has blurred the line between physical spaces and their virtual representations. The chapter discusses different sources of these data available for Digital Russian Studies (e.g., social data and crowdsourced databases) together with the novel techniques for extracting geolocation from various data formats (e.g., textual documents and images). It also scrutinizes different ways of using these data, varying from mapping the spatial distribution of social and political phenomena to investigating the use of geotag data for cultural practices’ digitization to exploring the use of geoweb for narrating individual and collective identities online

    Web-based tools can be used reliably to detect patients with major depressive disorder and subsyndromal depressive symptoms

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    BACKGROUND: Although depression has been regarded as a major public health problem, many individuals with depression still remain undetected or untreated. Despite the potential for Internet-based tools to greatly improve the success rate of screening for depression, their reliability and validity has not been well studied. Therefore the aim of this study was to evaluate the test-retest reliability and criterion validity of a Web-based system, the Internet-based Self-assessment Program for Depression (ISP-D). METHODS: The ISP-D to screen for major depressive disorder (MDD), minor depressive disorder (MinD), and subsyndromal depressive symptoms (SSD) was developed in traditional Chinese. Volunteers, 18 years and older, were recruited via the Internet and then assessed twice on the online ISP-D system to investigate the test-retest reliability of the test. They were subsequently prompted to schedule face-to-face interviews. The interviews were performed by the research psychiatrists using the Mini-International Neuropsychiatric Interview and the diagnoses made according to DSM-IV diagnostic criteria were used for the statistics of criterion validity. Kappa (κ) values were calculated to assess test-retest reliability. RESULTS: A total of 579 volunteer subjects were administered the test. Most of the subjects were young (mean age: 26.2 ± 6.6 years), female (77.7%), single (81.6%), and well educated (61.9% college or higher). The distributions of MDD, MinD, SSD and no depression specified were 30.9%, 7.4%, 15.2%, and 46.5%, respectively. The mean time to complete the ISP-D was 8.89 ± 6.77 min. One hundred and eighty-four of the respondents completed the retest (response rate: 31.8%). Our analysis revealed that the 2-week test-retest reliability for ISP-D was excellent (weighted κ = 0.801). Fifty-five participants completed the face-to-face interview for the validity study. The sensitivity, specificity, positive, and negative predictive values for major depressive disorder were 81.8% and 72.7%, 66.7%, and 85.7% respectively. The overall accuracy was 76.4%. CONCLUSION: The evidence indicates the ISP-D is a reliable and valid online tool for assessing depression. Further studies should test the ISP-D in clinical settings to increase its applications in clinical environments with different populations and in a larger sample size

    Preclinical electrogastrography in experimental pigs

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    Surface electrogastrography (EGG) is a non-invasive means of recording gastric myoelectric activity or slow waves from cutaneous leads placed over the stomach. This paper provides a comprehensive review of preclinical EGG. Our group recently set up and worked out the methods for EGG in experimental pigs. We gained our initial experience in the use of EGG in assessment of porcine gastric myoelectric activity after volume challenge and after intragastric administration of itopride and erythromycin. The mean dominant frequency in pigs is comparable with that found in humans. EGG in experimental pigs is feasible. Experimental EGG is an important basis for further preclinical projects in pharmacology and toxicology

    Interactive voice response technology for symptom monitoring and as an adjunct to the treatment of chronic pain

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    Chronic pain is a medical condition that severely decreases the quality of life for those who struggle to cope with it. Interactive voice response (IVR) technology has the ability to track symptoms and disease progression, to investigate the relationships between symptom patterns and clinical outcomes, to assess the efficacy of ongoing treatments, and to directly serve as an adjunct to therapeutic treatment for chronic pain. While many approaches exist toward the management of chronic pain, all have their pitfalls and none work universally. Cognitive behavioral therapy (CBT) is one approach that has been shown to be fairly effective, and therapeutic interactive voice response technology provides a convenient and easy-to-use means of extending the therapeutic gains of CBT long after patients have discontinued clinical visitations. This review summarizes the advantages and disadvantages of IVR technology, provides evidence for the efficacy of the method in monitoring and managing chronic pain, and addresses potential future directions that the technology may take as a therapeutic intervention in its own right
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