4,335 research outputs found

    PRIVACY ASSURANCE AND NETWORK EFFECTS IN THE ADOPTION OF LOCATION-BASED SERVICES: AN IPHONE EXPERIMENT

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    The use of geospatially aware mobile devices and applications is increasing, along with the potential for the unethical use of personal location information. For example, iPhone apps often ask users if they can collect location data in order to make the program more useful. The purpose of this research is to empirically examine the significance of this new and increasingly relevant privacy dimension. Through a simulation experiment, we examine how the assurance of location information privacy (as well as mobile app quality and network size) influences users\u27 perceptions of location privacy risk and the utility associated with the app which, in turn, affects their adoption intentions and willingness-to-pay for the app. The results indicate that location privacy assurance is of great concern and that assurance is particularly important when the app’s network size is low or if its quality cannot be verified

    Prospective Study of the Frequency and Outcomes of Patients with Suspected Pulmonary Embolism Administered Heparin Prior to Confirmatory Imaging

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    Objectives The administration of empiric systemic anticoagulation (ESA) before confirmatory radiographic testing in patients with suspected pulmonary embolism (PE) may improve outcomes, but no data have been published regarding current practice. We describe the use of ESA in a large prospective cohort of emergency department (ED) patients and report the outcomes of those treated with ESA compared with patients not receiving ESA. Methods 12-center, noninterventional study of ED patients who presented with symptoms concerning for PE. Clinical data including pretest probability and decision to start ESA were recorded at point of care by attending physicians. Patients were followed for adverse in-hospital outcomes and recurrence of venous thromboembolism. Results ESA was initiated 342/7932 (4.3%) of enrolled patients, including 142/618 (23%) patients with high pretest probability. Patients receiving ESA had more abnormal vital signs and were more likely to have a history of venous thromboembolism than those who did not receive ESA. Overall, 481/7,932 (6.1%) had PE diagnosed, 72/481 (15.0%) with PE had ESA, and 72/342 (21%) of ESA patients had PE. Three patients (0.9%, 95%CI: 0.2-2.5%) who received ESA suffered hemorrhagic complications compared with 38 patients (0.5%, 95%CI: 0.4-0.7%) who did not receive ESA. Conclusions In this multicenter sample, ED physicians administered ESA to a small, generally more acutely ill subset of patients with high pretest probability of PE, and very few had hemorrhagic complications. ESA was not associated with any clear difference in outcomes. More study is needed to clarify the risk versus benefit of ESA

    Spatial and temporal patterns of coral bleaching around Buck Island Reef National Monument, St. Croix, U.S. Virgin Islands

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    Since 2001, biannual fish and habitat monitoring has been conducted for the shallow (> 30 m), colonized pavement and gorgonian dominated Buck Island Reef National Monument (BIRNM) St. Croix, USVI and adjacent waters. during October, 2005, widespread coral bleaching was observed within the ∼50 square-kilometer study area that was preceded by 10 wks of higher than average water temperatures (28.9–30.1 °C). Random transects (100 square meters) were conducted on linear reefs, patch reefs, bedrock, pavement, and scattered coral/rock habitats during October 2005, and April and October 2006, and species specific bleaching patterns were documented. During October 2005 approximately 51% of live coral cover was bleached. Nineteen of 23 coral species within 16 genera and two hydrocoral species exhibited signs of bleaching. Coral cover for Montastraea annularis and species of the genus Agaricia were the most affected, while other species exhibited variability in their susceptibility to bleaching. Bleaching was evident at all depths (1.5–28 m), was negatively correlated with depth, and positively correlated with habitat complexity. Bleaching was less prevalent at all depths and habitat types upon subsequent monitoring during April (15%) and October (3%) 2006. Four species and one genus did not exhibit signs of bleaching throughout the study period (Dendrogyra cylindrus, Eusmilia fastigata, Mussa angulosa, Mycetophyllia aliciae, Scolymia spp.)

    A scalable architecture for ordered parallelism

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    We present Swarm, a novel architecture that exploits ordered irregular parallelism, which is abundant but hard to mine with current software and hardware techniques. In this architecture, programs consist of short tasks with programmer-specified timestamps. Swarm executes tasks speculatively and out of order, and efficiently speculates thousands of tasks ahead of the earliest active task to uncover ordered parallelism. Swarm builds on prior TLS and HTM schemes, and contributes several new techniques that allow it to scale to large core counts and speculation windows, including a new execution model, speculation-aware hardware task management, selective aborts, and scalable ordered commits. We evaluate Swarm on graph analytics, simulation, and database benchmarks. At 64 cores, Swarm achieves 51--122× speedups over a single-core system, and out-performs software-only parallel algorithms by 3--18×.National Science Foundation (U.S.) (Award CAREER-145299

    An assessment of chemical contaminants in the marine sediments of southwest Puerto Rico

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    This report summarizes the results of a characterization of chemical contaminants in the sediments in southwest Puerto Rico. The report is part of a project to integrate various analytical specialties to assess linkages between chemical contaminants and the condition of coral reefs. In this phase of the project, over 120 chemical contaminants were analyzed in sediments collected, including a number of organic (e.g., hydrocarbons), inorganic (e.g., metals), and biological (bacterial) compounds/analytes. The report also provides a preliminary analysis of the association between sediment contaminants and coral species richness. Overall, the levels of chemical contaminants in the study area between Guanica Bay and the town of La Parguera were fairly low. At most of the sites sampled, particularly adjacent to the town of La Parguera, concentrations of organic and inorganic contaminants were below the median values from NOAA’s National Status and Trends Program, which monitors the Nation’s coastal and estuarine waters for chemical contaminants. Elevated levels of a number of contaminant classes were seen at the two sites sampled within Guanica Bay. An initial analysis of modeled PAH (hydrocarbon) data and coral species richness (reef building species) indicated a strong negative correlation between the presence of PAHs in the sediments and coral species richness. Additional work is needed to assess possible reasons for this observed pattern. (PDF contains 126 pages)

    Proterozoic crustal evolution of central East Antarctica: Age and isotopic evidence from glacial igneous clasts, and links with Australia and Laurentia

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    Rock clasts entrained in glacial deposits sourced from the continental interior of Antarctica provide an innovative means to determine the age and composition of ice-covered crust. Zircon U-Pb ages from a suite of granitoid clasts collected in glacial catchments draining central East Antarctica through the Transantarctic Mountains show that crust in this region was formed by a series of magmatic events at ∼2.01, 1.88–1.85, ∼1.79, ∼1.57, 1.50–1.41, and 1.20–1.06 Ga. The dominant granitoid populations are ca. 1.85, 1.45 and 1.20–1.06 Ga. None of these igneous ages are known from limited outcrop in the region. In addition to defining a previously unrecognized geologic history, zircon O and Hf isotopic compositions from this suite have: (1) mantle-like δ18O signatures (4.0–4.5‰) and near-chondritic Hf-isotope compositions (εHf ∼ +1.5) for granitoids of ∼2.0 Ga age; (2) mostly crustal δ18O (6.0–8.5‰) and variable Hf-isotope compositions (εHf = −6 to +5) in rocks with ages of ∼1.88–1.85, ∼1.79 and ∼1.57 Ga, in which the ∼1.88–1.79 Ga granitoids require involvement of older crust; (3) mostly juvenile isotopic signatures with low, mantle-like δ18O (∼4–5‰) and radiogenic Hf-isotope signatures (εHf = +6 to +10) in rocks of 1.50–1.41 Ga age, with some showing crustal sources or evidence of alteration; and (4) mixed crustal and mantle δ18O signatures (6.0–7.5‰) and radiogenic Hf isotopes (εHf = +3 to +4) in rocks of ∼1.2 Ga age. Together, these age and isotopic data indicate the presence in cratonic East Antarctica of a large, composite igneous province that formed through a punctuated sequence of relatively juvenile Proterozoic magmatic events. Further, they provide direct support for geological correlation of crust in East Antarctica with both the Gawler Craton of present-day Australia and Proterozoic provinces in western Laurentia. Prominent clast ages of ∼2.0, 1.85, 1.57 and 1.45 Ga, together with sediment source linkages, provide evidence for the temporal and spatial association of these cratonic elements in the Columbia supercontinent. Abundant ∼1.2–1.1 Ga igneous and metamorphic clasts may sample crust underlying the Gamburtsev Subglacial Mountains, indicating the presence of a Mesoproterozoic orogenic belt in the interior of East Antarctica that formed during final assembly of Rodinia.Field and analytical portions of this project were supported by the National Science Foundation (award 0944645)

    Penerapan Model Pembelajaran Problem Based Learning (Pbl) untuk Meningkatkan Hasil Belajar Siswa pada Pokok Bahasan Kelarutan dan Hasil Kali Kelarutan di Kelas XI IPA SMA Negeri 1 Kampar

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    Research was aimed to improve study result of student on solubility and result times solubility subject has been doing in class XI science SMAN 1 Kampar. This research was a form of experiments research with design pretest-posttest. Sample of the research were student of class XI science 2 as experimental class and class XI science 3 as control class. The experimental class was applied learning model problem base learning while the control class using discussion method. Data were analized using t- test. Result from the data analysis showed t count > t table (1,6923 > 1,68). It means learning model problem based learning can increase study result of student on solubility and result times solubility subject in class XI science SMAN 1 Kampar with category of increase study results on the solubility and result times solubility in class XI science is high category

    Isoform-specific subcellular localization and function of protein kinase A identified by mosaic imaging of mouse brain.

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    Protein kinase A (PKA) plays critical roles in neuronal function that are mediated by different regulatory (R) subunits. Deficiency in either the RIβ or the RIIβ subunit results in distinct neuronal phenotypes. Although RIβ contributes to synaptic plasticity, it is the least studied isoform. Using isoform-specific antibodies, we generated high-resolution large-scale immunohistochemical mosaic images of mouse brain that provided global views of several brain regions, including the hippocampus and cerebellum. The isoforms concentrate in discrete brain regions, and we were able to zoom-in to show distinct patterns of subcellular localization. RIβ is enriched in dendrites and co-localizes with MAP2, whereas RIIβ is concentrated in axons. Using correlated light and electron microscopy, we confirmed the mitochondrial and nuclear localization of RIβ in cultured neurons. To show the functional significance of nuclear localization, we demonstrated that downregulation of RIβ, but not of RIIβ, decreased CREB phosphorylation. Our study reveals how PKA isoform specificity is defined by precise localization

    Status of the coral reef ecosystems in the U.S. Caribbean and Gulf of Mexico: Florida, Flower Garden Banks, Puerto Rico, Navassa and USVI

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    This chapter covers coral reef areas under the jurisdiction of the USA in the Wider Caribbean: Florida; Flower Garden Banks; Puerto Rico; U.S. Virgin Islands; and Navassa. The following information is condensed from six chapters of The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2008. Access to the full text of this comprehensive report is available at: http://ccma.nos.noaa.gov/stateofthereefs
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