364 research outputs found

    The effects of antidepressants appear to be rapid and at environmentally relevant concentrations

    Get PDF
    The effects of antidepressants on wildlife are currently raising some concern because of an increased number of publications indicating biological effects at environmentally relevant concentrations (\u3c100 ng/L). These results have been met with some scepticism because of the higher concentrations required to detect effects in some species and the perceived slowness to therapeutic effects recorded in humans and other vertebrates. Because their mode of action is thought to be by modulation of the neurotransmitters serotonin, dopamine, and norepinephrine, aquatic invertebrates that possess transporters and receptors sensitive to activation by these pharmaceuticals are potentially affected by them. The authors highlight studies on the effects of antidepressants, particularly on crustacean and molluskan groups, showing that they are susceptible to a wide variety of neuroendocrine disruptions at environmentally relevant concentrations. Interestingly, some effects observed in these species can be observed within minutes to hours of exposure. For example, exposure of amphipod crustaceans to several selective serotonin reuptake inhibitors can invoke changes in swimming behavior within hours. In mollusks, exposure to selective serotonin reuptake inhibitors can induce spawning in male and female mussels and foot detachment in snails within minutes of exposure. In the light of new studies indicating effects on the human brain from selective serotonin reuptake inhibitors using magnetic resonance imaging scans, the authors discuss possible reasons for the discrepancy in former results in relation to the read-across hypothesis, variation in biomarkers used, modes of uptake, phylogenetic distance, and the affinity to different targets and differential sensitivity to receptors

    Slip distribution and tectonic implication of the 1999 Chi‐Chi, Taiwan, Earthquake

    Get PDF
    We report on the fault complexity of the large (M_w = 7.6) Chi‐Chi earthquake obtained by inverting densely and well‐distributed static measurements consisting of 119 GPS and 23 doubly integrated strong motion records. We show that the slip of the Chi-Chi earthquake was concentrated on the surface of a ”wedge shaped” block. The inferred geometric complexity explains the difference between the strike of the fault plane determined by long period seismic data and surface break observations. When combined with other geophysical and geological observations, the result provides a unique snapshot of tectonic deformation taking place in the form of very large (>10m) displacements of a massive wedge‐shaped crustal block which may relate to the changeover from over‐thrusting to subducting motion between the Philippine Sea and the Eurasian plates

    Antecedents of Product Placement Effectiveness Across Cultures

    Get PDF
    Purpose -- The research contributes to the marketing literature by developing and testing a conceptual model to examine the effects of product placement across a country low in assertiveness and performance orientation (the United Kingdom) and a country high in assertiveness and performance orientation (Hong Kong). Design/methodology/approach -- A content analysis of brand appearances in high grossing films within the UK and HK was conducted followed by a 2x2 between-subjects experiment (n=572). Findings -- The results indicate participants exposed to prominent placements have a less positive brand attitude and lower purchase intention towards the placed brand. Likewise, respondents exposed to a less well-known placed brand tend to have a less positive brand attitude and lower purchase intention towards the placed brand. There is evidence of interaction effects with cultural dimensions such as assertiveness and performance orientation within the UK and HK. Practical implications -- The results suggest that product placements can be optimized through tailored campaigns targeted at markets with known cultural characteristics. With advances in digital technology such practices are becoming more frequent and more feasible. Originality/value -- This is one of the first studies to explore the effect of culture on perceptions of product placement and the first study to empirically examine the role of prominence and brand awareness, and their interactions with GLOBE values on the effectiveness of product placement

    Validation of the rupture properties of the 2001 Kunlun, China (M_s=8.1), earthquake from seismological and geological observations

    Get PDF
    We determine the finite-fault slip distribution of the 2001 Kunlun earthquake (M_s = 8.1) by inverting teleseismic waveforms, as constrained by geological and remote sensing field observations. The spatial slip distribution along the 400-km-long fault was divided into five segments in accordance with geological observations. Forward modelling of regional surface waves was performed to estimate the variation of the speed of rupture propagation during faulting. For our modelling, the regional 1-D velocity structure was carefully constructed for each of six regional seismic stations using three events with magnitudes of 5.1–5.4 distributed along the ruptured portion of the Kunlun fault. Our result shows that the average rupture velocity is about 3.6 km s^−1, consistent with teleseismic long period wave modelling. The initial rupture was almost purely strike-slip with a rupture velocity of 1.9 km s^−1, increasing to 3.5 km s^−1 in the second fault segment, and reaching a rupture velocity of about 6 km s^−1 in the third segment and the fourth segment, where the maximum surface offset, with a broad fault zone, was observed. The rupture velocity decelerated to a value of 3.3 km s^−1 in the fifth and final segment. Coseismic slip on the fault was concentrated between the surface and a depth of about 10 km. We infer that significant variations in rupture velocity and the observed fault segmentation are indicative of variations in strength along the interface of the Kunlun fault, as well as variations in fault geometry

    Observation of temporal variations in seismic anisotropy within an active fault‐zone revealed from the Taiwan Chelungpu‐fault Drilling Project Borehole Seismic Array

    Get PDF
    Temporal fault-zone observations are important to better understand the evolution of fault structure and stress configuration. However, long-term monitoring in the fault-zone is rare after a large earthquake. Here, we use seismic data in the fault-zone at 1-km depth from the Taiwan Chelungpu-fault Drilling Project to study long-term anisotropy after the 1999 Mw7.6 Chi-Chi earthquake. The direct S-wave splitting measurements resolve the overall weak anisotropy in the shallow crust. In order to resolve fault damage zone anisotropy, we perform coda cross-correlation technique for 794 microearthquakes between 2007 and 2013. We estimate the temporal change in background shear-wave velocity, fast shear-wave polarization direction (FSP), and strength of anisotropy (Aani) in the fault damage zone. We show the average FSP direction is N93°E with a significant Aani of about 12%, likely due to the pervasive vertical microcracks created after the earthquake. Temporal variations of anisotropy exhibit seasonal variation with periodicity every 9 to 12 months that correlates with rainfall events. Furthermore, long-term anisotropy shows a gradual rotation of FSP direction of about 15° during the first 4 years of observation. At the same time, the strength of anisotropy reduced from 17 to 10 % and shear-wave velocity increased, suggesting the fault healed after the earthquake. This study reports in-situ evidence for two key observations: (1) long-term, fault-zone healing after a major earthquake, and (2) modulation of 1-km deep fault-zone properties by surficial hydrologic processes. These observations may provide constraints on the response of the fault damage zone in the interseismic period

    Wireless Home Security System

    Get PDF
    The primary objective of WInnovations is to develop a wireless security system that takes into consideration home safety and security without the hefty monthly costs associated with home security monitoring services or high installation fees. The security system will contain various sensor modules which interface with a main transceiver module to send signals wirelessly to another transceiver connected via serial port to a household computer. The user can monitor safety and security activity on a custom interface on the computer or receive notification via e-mail or text messages through SMS (Short Message Service).&nbsp

    Increasing Trunk Mass Evokes Lower Extremity Biomechanical Plasticity during Stair Descent

    Get PDF
    International Journal of Exercise Science 16(1): 942-953, 2023. The purpose of this study was to investigate the influence of simulated changes in body mass on lower extremity joint work and relative joint contributions during stair descent. Ten healthy recreationally active college-age participants performed five stair descent trials in each of five loading conditions: no added load and with an additional 5%, 10%, 15% and 20% of their body weight. Three-dimensional ankle, knee and hip joint powers were calculated using a six degree-of-freedom model in Visual3D (C-Motion Inc., Germantown, MD, USA). Sagittal plane joint work was calculated as the joint power curve integrated with respect to time during the period between initial contact and toe off. Prism 9.0 (GraphPad Inc., San Diego, CA) was used to perform univariate 1 x 5 repeated measures analyses of variance to determine the effect of added mass on absolute and relative joint work values for total and for each lower extremity joint independently. Increasing added mass was associated with greater total lower extremity negative work during the stair descent task (p \u3c 0.001). At the ankle, increasing added mass was associated with increasing magnitudes of negative joint work. Increasing added mass was associated with greater relative contributions of the ankle and reduced knee contributions to total negative lower extremity joint work (p = 0.014 and p = 0.006). The current findings demonstrated increases in ankle joint contributions to total lower extremity work while knee joint contributions to total lower extremity work were reduced in response to increasing added mass
    • 

    corecore