408 research outputs found

    Energy Dissipation of Eccentrically-braced-frame (Ebf) with Different Level of Eccentricity

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    This research aimed at eliciting the form of relation that exists between level ofeccentricity (e/L) and energy dissipation (Ed) of an Eccentrically Braced Frame (EBF).It continued a previous research that studied relative stiffness of an EBF. Three sets ofEBF specimen were analysed by the merit of SAP2000 v9.0.1 computer-software toobtain range of inelastic drifts and its corresponding range of lateral loads. Specimensvary in level of eccentricity (e/L) and bay to height ration (h/L). Prior to it, a formulathat calculates energy dissipation of a lateral resistant structure as product of lateralloads and the corresponding drifts was developed and used throughout the research forthe purpose of quantifying Ed. Each specimen was alternatively loaded in directionconfronting and concurring the bracing component. It was found that there was nosignificant difference in the form of relation between e/L and Ed, when lateral loadapplied confronting bracing component from when the same load applied concurringbracing component. Forms of each graph that relates e/L to Ed was presented andshown to consists of two parts, divided at e/L = 0.2; suggesting that e/L = 0.2 might bethe point where level of eccentricity and relative stiffness of an EBF reach optimum.Mathematical equations for the relation between e/L and Ed of an EBF were thendeveloped. In spite of this, an inconsistency with the prevalent theory was observed,hence the relations between e/L and Ed concluded so far were contested until furtherresearches be made for clarification

    Hubungan Tingkat Kecemasan Dengan Mekanisme Koping Pada Penderita Diabetes Melitus Tipe II Di Poliklinik Penyakit Dalam Rumah Sakit Umum Daerah Tobelo Kabupaten Halmahera Utara

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    . Diabetes mellitus is a chronic disease that has a negative impact on psychological well-being of patients, the psychological effects such as anxiety. Anxiety is a reaction to the disease as perceived as a threat, discomfort. Coping mechanism is a method to adapt to the changes that occur. The purpose of the study was to determine the level of anxiety is there a relationship with coping mechanisms in patients with type II diabetes mellitus in internal medicine clinic Tobelo hospital. The design of this study using cross-sectional approach. Sample of 32 people, with purposive sampling method. Data were collected by interview using a questionnaire. The results of the study found a 12,5% rate of mild anxiety, medium anxiety 43,8%, severe anxiety 43,8% and adaptive coping mechanism 62,5%, maladaptive coping 37,5% . The results of hypothesis testing with Chi Square test shows that the value of p = 0,002, p is less than α (0,05) . Conclusion that there is a relationship anxiety levels with coping mechanisms in patients with type II diabetes mellitus

    Possible involvement of the inhibition of NF-kβ factor in anti_inflammatory actions that melatonin exert on mast cells

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    Melatonin is a molecule endogenously produced in a wide variety of immune cells, including mast cells (RBL-2H3). It exhibits immunomodulatory, anti-inflammatory and anti-apoptotic properties. The physiologic mechanisms underlying these activities of melatonin have not been clarified in mast cells. This work is designed to determine the anti-inflammatory effect and mechanism of action of melatonin on activated mast cells. RBL-2H3 were pre-treated with exogenous melatonin (MELx) at physiological (100nM) and pharmacological (1mM) doses for 30 min, washed and activated with PMACI (phorbol 12-myristate 13-acetate plus calcium ionophore A23187) for 2h and 12h. The data shows that pre-treatment of MELx in stimulated mast cells, significantly reduced the levels of endogenous melatonin production (MELn), TNF-alpha and IL-6. These effects are directly related with the MELx concentration used. MELx also inhibited IKK/NF-kB signal transduction pathway in stimulated mast cells. These results indicate a molecular basis for the ability of melatonin to prevent inflammation and for the treatment of allergic inflammatory diseases through the down-regulation of mast cell activation

    Oceanic cooling recorded in shells spanning the Medieval Climate Anomaly in the subtropical eastern North Atlantic Ocean

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    The Medieval Climate Anomaly (MCA; 900–1300 AD) was the most recent period of pre-industrial climatic warming in the northern hemisphere, and thus estimations of MCA signals can illuminate possible impacts of anthropogenic climate change. Current high-resolution MCA climate signals are restricted to mid- and high-latitude regions, which confounds inferences of how the MCA impacted some global/hemispheric climate mechanisms (e.g. North Atlantic Oscillation; NAO). To address this knowledge gap, we estimate seasonally-resolved sea surface temperatures (SSTs) from the oxygen isotope composition (δ18O) of serially sampled Phorcus atratus shells from archaeological sites spanning the MCA in the Canary Islands. Twelve archaeological and six modern P. atratus shells were analyzed, and archaeological shells were dated using carbonate-target radiocarbon dating. SSTs were estimated using the published aragonite-water equilibrium fractionation equation. Modern shells showed a mean SST of 20.0 ± 1.5 °C, with a seasonal amplitude of 5.3 ± 0.9 °C. Archaeological shells exhibited a mean SST of 18.2 ± 0.7 °C, with a mean seasonal amplitude of 5.5 ± 1.0 °C. Thus, shells that span the MCA in the Canary Islands recorded SSTs that were significantly cooler than the modern (P <.05), contrasting with warming estimates and model predictions elsewhere in the Northern Hemisphere. We propose that the observed cooling resulted from increased upwelling in NW Africa due to a strengthening of the prevailing westerlies and coastal winds along the African shoreline. The intensified upwelling scenario during the MCA is partially supported by in-situ carbon isotope data (δ13C) retrieved from the archaeological shells, which was compared to the δ13C values of modern shells and dissolved inorganic carbon in the ambient seawater. These results are consistent with other low-latitude temperature/precipitation anomalies associated with a positive NAO mode, suggesting a transition to a positive NAO index during the middle and late MCA that possibly extended later into the 13th century AD

    Calibration of the oxygen isotope ratios of the gastropods Patella candei crenata and Phorcus atratus as high-resolution paleothermometers from the subtropical eastern Atlantic Ocean

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    The oxygen isotope composition (δ18O) recorded in shells of the gastropods Patella candei crenata and Phorcus atratus from the Canary Islands (27–29°N) potentially provide invaluable high-resolution paleoclimatic data. However, because these two species have never been studied isotopically, it is necessary to calibrate and validate this approach by using live-collected specimens that can be compared to present-day climate data. For P. candei crenata, live organisms were collected at 15-day intervals for nearly one year (between 2011 and 2012) from the rocky-intertidal coast of SE Tenerife along with sea surface temperatures (SST) and seawater δ18O values. The δ18O values of the last growth episode along the shell growth margin, representing the conditions when organisms were collected, illustrate that P. candei crenata δ18O values were 1.3 ± 0.2‰ higher than expected values from isotopic equilibrium. This finding resulted in estimated SST 5.7 ± 0.6 °C lower than observed values. This offset or “vital effect” is uniform and predictable, and therefore can be corrected by subtracting 1.3‰ from the measured shell δ18O value. Adjusted temperatures from the shell coincided with observed SST in the study area. Therefore, Patella candei crenata shells are reliable repositories of SST data, in agreement with other species of Patella from higher latitudes. For Phorcus atratus, a live specimen was analyzed isotopically along shell-growth direction. The intrashell δ18O values showed the entire range of measured SST in the region without an apparent “vital effect”, in correspondence with other Phorcus species from the Mediterranean. Both Patella candei crenata and Phorcus atratus are common components of archaeological and Pleistocene-Holocene paleontological sites across the Canary Archipelago. This study suggests that well-preserved shells of these two taxa retrieved from ancient settings have the capacity to serve as excellent high-resolution paleotemperature archives for the tropical/subtropical eastern Atlantic region

    Voting behavior during FDA Medical Device Advisory Committee panel meetings

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    OBJECTIVES: During premarket review, the US Food and Drug Administration may ask its Medical Device Advisory Committee (MDAC) Panels to assess the safety and effectiveness of medical devices being considered for approval. The objective of this study is to assess the relationship, if any, between individual votes and Panel recommendations and: (1) the composition of Panels, specifically the expertise and demographic features of individual members; or (2) Panel members\u27 propensity to speak during Panel deliberations. METHODS: This was a retrospective cohort study of routinely collected data from voting members of MDAC panels convened between January 2011 to June 2016 to consider premarket approval. Data sources were verbatim transcripts available publicly from the FDA. Number of words spoken, directionality of votes on device approval, profession, and demographics were collected. RESULTS: 658,954 words spoken by 536 members during 49 meetings of 11 Panels were analyzed. Based on multivariate analysis, biostatisticians spoke more (+373 words; P = 0.0002), and women (-187 words; P = 0.0184) and other non-physician voting members less (-213 words; P = 0.0306), than physicians. Speaking more was associated with abstaining (P = 0.0179), and with voting against the majority (P = 0.0153). Non-physician, non-biostatistician members (P = 0.0109), and those having attended more meetings as a voting member (P = 0.0249) were more likely to vote against approval. In bivariable analysis, unanimous Panels had a greater proportion of biostatisticians (mean 0.1580; 95% CI 0.1237-0.1923) than non-unanimous Panels (0.1107; 95% CI 0.0912-0.1301; p = 0.0201). CONCLUSIONS: Panelists likely to vote against the majority include non-physician, non-biostatisticians; experienced Panelists; and more talkative members. The increased presence of biostatisticians on Panels leads to greater voting consensus. Having a diversity of opinions on Panels, including in sufficient numbers those members likely to dissent from majority views, may help ensure that a diversity of opinions are aired before decision-making

    Voting behavior during FDA Medical Device Advisory Committee panel meetings

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    Objectives During premarket review, the US Food and Drug Administration may ask its Medical Device Advisory Committee (MDAC) Panels to assess the safety and effectiveness of medical devices being considered for approval. The objective of this study is to assess the relationship, if any, between individual votes and Panel recommendations and: (1) the composition of Panels, specifically the expertise and demographic features of individual members; or (2) Panel members’ propensity to speak during Panel deliberations. Methods This was a retrospective cohort study of routinely collected data from voting members of MDAC panels convened between January 2011 to June 2016 to consider premarket approval. Data sources were verbatim transcripts available publicly from the FDA. Number of words spoken, directionality of votes on device approval, profession, and demographics were collected. Results 658,954 words spoken by 536 members during 49 meetings of 11 Panels were analyzed. Based on multivariate analysis, biostatisticians spoke more (+373 words; P = 0.0002), and women (-187 words; P = 0.0184) and other non-physician voting members less (-213 words; P = 0.0306), than physicians. Speaking more was associated with abstaining (P = 0.0179), and with voting against the majority (P = 0.0153). Non-physician, non-biostatistician members (P = 0.0109), and those having attended more meetings as a voting member (P = 0.0249) were more likely to vote against approval. In bivariable analysis, unanimous Panels had a greater proportion of biostatisticians (mean 0.1580; 95% CI 0.1237–0.1923) than non-unanimous Panels (0.1107; 95% CI 0.0912–0.1301; p = 0.0201). Conclusions Panelists likely to vote against the majority include non-physician, non-biostatisticians; experienced Panelists; and more talkative members. The increased presence of biostatisticians on Panels leads to greater voting consensus. Having a diversity of opinions on Panels, including in sufficient numbers those members likely to dissent from majority views, may help ensure that a diversity of opinions are aired before decision-making

    Scale of time-averaging in archaeological shell middens from the Canary Islands

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    Characterizing the degree of disturbance in archaeological deposits is critically important for archaeologists assessing foraging strategies, environmental conditions, or behavior patterns of ancient human groups. Qualitative techniques (e.g. micromorphology analysis) have previously been applied to assess the degree of disturbance (age-mixing) in archaeological sites; however, quantitative dating of material in the sites provides a more robust assessment of potential age-mixing. Unfortunately, because of budget constraints, archaeologists are frequently forced to rely on few quantitative age dates for an assemblage, thus obfuscating the signal of age-mixing of the deposit. The development of an affordable and rapid carbonate-target accelerator mass spectrometry (AMS) radiocarbon (14C) dating method provides a cost-effective way to retrieve more quantitative dates from carbonate material in archaeological assemblages to assess the degree of age-mixing in the deposit. This study tests this new technique and dates numerous harvested marine limpet shells from archaeological sites in the Canary Islands to determine whether there is multidecadal to multicentennial age-mixing. A total of 58 shells retrieved from six sites and three islands yielded uncalibrated radiocarbon ages ranging from 2265 ± 40 to 765 ± 35 BP, coinciding with the time of prehistoric human occupation in these islands. While most shells from the same stratum showed statistically equivalent ages, in some cases we detected age ranges that exceeded the imprecisions from analytical errors. This investigation is one of the first to quantitatively illustrate that shells retrieved from depth intervals without evident stratigraphic disturbance do not always contain contemporaneous remains and, therefore, dating each specimen is valuable for developing further paleoclimatic and paleoanthropological inferences. This study presents the first report of carbonate-target 14C ages from archaeological shell middens, and suggests that this novel radiocarbon methodology can be applied to these sites, thus allowing the generation of a more comprehensive chronology

    Millennial-scale cyclical environment and climate variability during the Holocene in the western Mediterranean region deduced from a new multi-proxy analysis from the Padul record (Sierra Nevada, Spain)

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    A high-resolution multi-proxy approach, integrating pollen, inorganic and organic geochemical and sedimentological analyses, has been carried out on the Holocene section of the Padul sedimentary record in the southern Iberian Peninsula reconstructing vegetation, environment and climate throughout the last ~ 11.6 cal kyr BP in the western Mediterranean. The study of the entire Holocene allows us to determine the significant climate shift that occurred during the middle-to-late Holocene transition. The highest occurrence of deciduous forest in the Padul area from ~ 9.5 to 7.6 cal kyr BP represents the Holocene humidity optimum probably due to enhanced winter precipitation during a phase of highest seasonal anomaly and maximum summer insolation. Locally, insolation maxima induced high evaporation, counterbalancing the effect of relatively high precipitation, and triggered very low water table in Padul and the deposition of peat sediments. A transitional environmental change towards more regional aridity occurred from ~ 7.6 to 4.7 cal kyr BP and then aridification enhanced in the late Holocene most likely related to decreasing summer insolation. This translated into higher water levels and a sedimentary change at ~ 4.7 cal kyr BP in the Padul wetland, probably related to reduced evaporation during summer in response to decreased in seasonality. Millennial-scale variability is superimposed on the Holocene long-term trends. The Mediterranean forest regional climate proxy studied here shows significant cold-arid events around ~ 9.6, 8.5, 7.5, 6.5 and 5.4 cal kyr BP with cyclical periodicities (~1100 and 2100 yr) during the early and middle Holocene. A change is observed in the periodicity of these cold-arid events towards ~1430 yr in the late Holocene, with forest declines around ~ 4.7–4, 2.7 and 1.3 cal kyr BP. The comparison between the Padul-15-05 data with published North Atlantic and Mediterranean paleoclimate records suggests common triggers for the observed climate variability, with the early and middle Holocene forest declines at least partially controlled by external forcing (i.e. solar activity) and the late Holocene variability associated with internal mechanisms (oceanic-atmospheric)
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