2,224 research outputs found
The Comparative Morphology of the Female Gonads of Two Members of the Nematode Order Tylenchida
Quantum initial condition sampling for linearized density matrix dynamics: Vibrational pure dephasing of iodine in krypton matrices
This paper reviews the linearized path integral approach for computing time
dependent properties of systems that can be approximated using a mixed
quantum-classical description. This approach is applied to studying vibrational
pure dephasing of ground state molecular iodine in a rare gas matrix. The
Feynman-Kleinert optimized harmonic approximation for the full system density
operator is used to sample initial conditions for the bath degrees of freedom.
This extremely efficient approach is compared with alternative initial
condition sampling techniques at low temperatures where classical initial
condition sampling yields dephasing rates that are nearly an order of magnitude
too slow compared with quantum initial condition sampling and experimental
results.Comment: 20 pages and 8 figure
Suborbital Payload Testing Aboard Level 3 Rocket Research Platform
Embry-Riddle Aeronautical University (ERAU) has launched several suborbital scientific payloads aboard Blue Origin’s New Shepard in 2017 and 2019. Students continue gaining hands-on experience in rocket design and construction, and payload integration and testing of future and more mature payloads to be launched into space. A Level 3 Rocket is being designed and developed at ERAU to serve as a scaled-down model research platform for launching and testing of payloads that will be later flown in commercial suborbital platforms such as Blue Origin’s New Shepard and PLD space Miura 1 rockets. Computer simulations were conducted to calculate the key parameters such as flight trajectory profiles, stability and flight velocities for different rocket motors configurations. A preliminary design of the rocket was developed using Computer-Aided Design (CAD) software. The rocket will accommodate multiple payloads (Cubesats, NanoLabs, TubeSats) designed and developed in the Payload Applied, Technology and Operations (PATO) laboratory. The rocket will be primarily constructed of carbon fiber composite as it has a high strength to weight ratio. These simulations are used to select a suitable motor for the rocket according to the flight requirements and landing restrictions. This prospective Level 3 Rocket is referred to as Suborbital Technology Experimental Vehicle for Exploration (STEVE). Rocket procedures and results from the design, simulation, construction and assembly will be presented
Pandemic influenza control in Europe and the constraints resulting from incoherent public health laws
© 2010 Martin et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: With the emergence of influenza H1N1v the world is facing its first 21st century global pandemic. Severe Acute Respiratory Syndrome (SARS) and avian influenza H5N1 prompted development of pandemic preparedness plans. National systems of public health law are essential for public health stewardship and for the implementation of public health policy[1]. International coherence will contribute to effective regional and global responses. However little research has been undertaken on how law works as a tool for disease control in Europe. With co-funding from the European Union, we investigated the extent to which laws across Europe support or constrain pandemic preparedness planning, and whether national differences are likely to constrain control efforts. Methods: We undertook a survey of national public health laws across 32 European states using a questionnaire designed around a disease scenario based on pandemic influenza. Questionnaire results were reviewed in workshops, analysing how differences between national laws might support or hinder regional responses to pandemic influenza. Respondents examined the impact of national laws on the movements of information, goods, services and people across borders in a time of pandemic, the capacity for surveillance, case detection, case management and community control, the deployment of strategies of prevention, containment, mitigation and recovery and the identification of commonalities and disconnects across states. Results: Results of this study show differences across Europe in the extent to which national pandemic policy and pandemic plans have been integrated with public health laws. We found significant differences in legislation and in the legitimacy of strategic plans. States differ in the range and the nature of intervention measures authorized by law, the extent to which borders could be closed to movement of persons and goods during a pandemic, and access to healthcare of non-resident persons. Some states propose use of emergency powers that might potentially override human rights protections while other states propose to limit interventions to those authorized by public health laws. Conclusion: These differences could create problems for European strategies if an evolving influenza pandemic results in more serious public health challenges or, indeed, if a novel disease other than influenza emerges with pandemic potential. There is insufficient understanding across Europe of the role and importance of law in pandemic planning. States need to build capacity in public health law to support disease prevention and control policies. Our research suggests that states would welcome further guidance from the EU on management of a pandemic, and guidance to assist in greater commonality of legal approaches across states.Peer reviewe
Институциональные условия усиления внедрения инвестиций интенсивного типа
Большое значение в процессе повышения эффективности общественного воспроизводства на основе усиления внедрения инноваций и инвестиций интенсивного типа имеет создание оптимальных институциональных условий и предпосылок. В этой связи в работе исследуются факторы формирования оптимальной институциональной среды как основы интенсификации российской экономики.Велике значення у процесі підвищення ефективності суспільного відтворення на основі посилення впровадження інновацій та інвестицій інтенсивного типу має створення оптимальних інституційних умов і передумов. У зв'язку із цим у роботі досліджуються чинники формування оптимального інституційного середовища як основи інтенсифікації російської економіки.Creation of optimal institutional conditions and preconditions is of great importance in the process of increasing the efficiency of public reproduction on the basis of strengthening the introduction of innovations and investments of intensive type. In this respect the factors of formation of optimal institutional environment as the bases for intensification of the Russian economy are analyzed
Nature-Based Tourism Sustainability and Climatic Change Implication in Ikogosi Resort, Southwestern Nigeria
The implications of climatic changes have been predicted to have devastating effects on biodiversity condition particularly nature-based tourism. In this study, investigation on the climatic characteristics in Ikogosi-Ekiti, Nigeria was conducted. Also, spatio-temporal changes of green and non-green cover were analysed for the study.
Climatic data from Nigeria Meteorological Agency (NIMET) for a period of 1975-2014 were analyzed to reveal the trend of climatic changes using appropriate statistical tool. A 30 meter Landsat image of TM 1991, ETH+ 2002 and OLI 2015 were used for the study. The satellite images were digitally processed using Arcgis10.3 and Fragstat 3.0. Species Diversity and Normalized Difference Vegetation Index (NDVI) analysis was conducted to assess the vegetation degradation in the study area.
The result showed that rainfall and temperature pattern between the year 1975 to 2014 experience an upward trend with maximum rainfall observed in year 2010 (1692.500mm) and temperature distribution reached its peak in year 2010 (27.046o C); annual temperature increment over the years is at regression model 0.016o C per year. Furthermore, results showed that anthropogenic activities as a result of tourism developmental programmes accounted for 25.93% increase in built-up between the periods of 1991 and 2015 with a substantial loss (29.97%) of dense vegetation were observed within the study area. In addition, Shannon Diversity Index (SHIDI) showed diversity decrease of 0.54, 0.47 and 0.21 for year 1991, 2002 and 2015 respectively; NDVI analysis revealed a degraded vegetation with the epoch of the years assessed. The result revealed that changes in rainfall and temperature pattern negatively affected the luxuriant vegetation; uncultured human activities led to massive reduction in the quality of remnant forest. However, tourism vegetation potentials of the study area were threatened; hence, ecosystem imbalance and animal migration were observed.
The study concluded that climate change and vegetation removal has significant effect on the green infrastructures, nature-based tourism and biodiversity conservation. The study recommends a need for ecotourism practices and strict protection of the tourist sit
MedZIM: Mediation analysis for Zero-Inflated Mediators with applications to microbiome data
The human microbiome can contribute to the pathogenesis of many complex
diseases such as cancer and Alzheimer's disease by mediating disease-leading
causal pathways. However, standard mediation analysis is not adequate in the
context of microbiome data due to the excessive number of zero values in the
data. Zero-valued sequencing reads, commonly observed in microbiome studies,
arise for technical and/or biological reasons. Mediation analysis approaches
for analyzing zero-inflated mediators are still lacking largely because of
challenges raised by the zero-inflated data structure: (a) disentangling the
mediation effect induced by the point mass at zero; and (b) identifying the
observed zero-valued data points that are actually not zero (i.e., false
zeros). We develop a novel mediation analysis method under the
potential-outcomes framework to fill this gap. We show that the mediation
effect of the microbiome can be decomposed into two components that are
inherent to the two-part nature of zero-inflated distributions. The first
component corresponds to the mediation effect attributable to a unit-change
over the positive relative abundance and the second component corresponds to
the mediation effect attributable to discrete binary change of the mediator
from zero to a non-zero state. With probabilistic models to account for
observing zeros, we also address the challenge with false zeros. A
comprehensive simulation study and the applications in two real microbiome
studies demonstrate that our approach outperforms existing mediation analysis
approaches.Comment: Corresponding: Zhigang L
Mapping plasma structures in the high-latitude ionosphere using beacon satellite, incoherent scatter radar and ground-based magnetometer observations
In the autumn of the year 2000, four radio receivers capable of tracking various beacon satellites were set up along the southwestern coast of Greenland. They are used to reconstruct images of the ionospheric plasma density distribution via the tomographic method. In order to test and validate tomographic imaging under the highly variable conditions often prevailing in the high-latitude ionosphere, a time interval was selected when the Sondrestrom incoherent scatter radar conducted measurements of the ionospheric plasma density while the radio receivers tracked a number of beacon satellites. A comparison between two-dimensional images of the plasma density distribution obtained from the radar and the satellite receivers revealed generally good agreement between radar measurements and tomographic images. Observed discrepancies can be attributed to F region plasma patches moving through the field of view with a speed of several hundred meters per second, thereby smearing out the tomographic image. A notable mismatch occurred around local magnetic midnight when a magnetospheric substorm breakup occurred in the vicinity of southwest Greenland (identified from ground-based magnetometer observations). The breakup was associated with a sudden intensification of the westward auroral electrojet which was centered at about 69 and extended up to some 73 corrected geomagnetic latitude. Ground-based magnetometer data may thus have the potential of indicating when the tomographic method is at risk and may fail. We finally outline the application of tomographic imaging, when combined with magnetic field data, to estimate ionospheric Joule heating rates
Pilot Project: Use of Wikis to Supplement Student Orientation
Background: During the orientation process, new students are often inundated with manuals, maps, and other materials essential to their success as students. The experience can leave students feeling overwhelmed, unable to sift through the substantial amount of information that has been given to them. Wikis, in contrast, are well-suited for facilitating userinteraction with vast amounts of diverse information. [See PDF for complete abstract
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