Drag and inertia coefficients for horizontally submerged rectangular cylinders in waves and currents

The results of an experimental investigation carried out to measure combined wave and current loads on horizontally submerged square and rectangular cylinders are reported in this paper. The wave and current induced forces on a section of the cylinders with breadth-depth (aspect) ratios equal to 1, 0.5, and 0.75 are measured in a wave tank. The maximum value of Keulegan-Carpenter (KC) number obtained in waves alone is about 5 and Reynolds (Re) number ranged from 6.3976103 to 1.186105. The drag (CD) and inertia (CM) coefficients for each cylinder are evaluated using measured sectional wave forces and particle kinematics calculated from linear wave theory. The values of CD and CM obtained for waves alone have already been reported (Venugopal, V., Varyani, K. S., and Barltrop, N. D. P. Wave force coefficients for horizontally submerged rectangular cylinders. Ocean Engineering, 2006, 33, 11-12, 1669-1704) and the coefficients derived in combined waves and currents are presented here. The results indicate that both drag and inertia coefficients are strongly affected by the presenceof the current and show different trends for different cylinders. The values of the vertical component inertia coefficients (CMY) in waves and currents are generally smaller than the inertia coefficients obtained in waves alone, irrespective of the current's magnitude and direction. The results also illustrate the effect of a cylinder's aspect ratio on force coefficients. This study will be useful in the design of offshore structures whose columns and caissons are rectangular sections

Research on the Human Dimensions of Climate Change in Nunavut, Nunavik, and Nunatsiavut: A Literature Review and Gap Analysis

Research on the human dimensions of climate change (HDCC) in the Canadian Arctic has expanded so rapidly over the past decade that we do not have a clear grasp of the current state of knowledge or research gaps. This lack of clarity has implications for duplication of climate policy and research, and it has been identified as a problem by communities, scientists, policy makers, and northern organizations. Our review of current knowledge about the HDCC in Nunavut, Nunavik, and Nunatsiavut indicates that the effects of climate change on subsistence harvesting and other land-based activities and the determinants of vulnerability and adaptation to such changes are well understood. However, the effects of climate change on health are less known. In the nascent research on this topic, studies on food security and personal safety dominate, and little peer-reviewed scholarship focuses on the business and economic sector. Published research shows a strong bias toward case studies in smaller communities, especially communities in Nunavut. Such studies have focused primarily on negative impacts of climate change, present-day vulnerabilities, and adaptive capacity, but studies proposing opportunities for adaptation intervention are beginning to emerge. While documenting the serious risks posed by climate change, they also highlight the adaptability of northern populations and the effects of economic-political stresses on vulnerability to changing climate. We note the absence of studies that examine how Northerners can benefit from new opportunities that may arise from climate change, or assess how the interaction of future climatic and socio-economic changes (specifically, resource development and enhanced shipping) will affect their experience of and response to climate change, or discuss the broader determinants of vulnerability and adaptation.L’étude des dimensions humaines du changement climatique (DHCC) dans l’Arctique canadien a pris de l’ampleur ces dix dernières années au point où nous n’avons pas une idée claire de l’état actuel des connaissances ou des lacunes en matière de recherche. Cette absence de précision a des incidences sur le plan du dédoublement des politiques et des études sur le climat, ce qui est considéré comme problématique par les collectivités, les scientifiques, les décisionnaires et les organi­sations se trouvant dans le Nord. Nous avons passé en revue les connaissances actuelles en matière de DHCC au Nunavut, au Nunavik et au Nunatsiavut, ce qui nous a permis de constater que les effets du changement climatique sur les récoltes de subsistance et sur d’autres activités rattachées aux ressources naturelles sont bien compris, tout comme le sont les déterminants de la vulnérabilité et de l’adaptation à ces changements. Cela dit, les effets du changement climatique sur la santé sont moins bien connus. Dans le cadre des recherches à l’état naissant à ce sujet, les études portant sur l’innocuité alimentaire et la sécurité personnelle dominent, et peu d’études évaluées par les pairs sont axées sur le secteur commercial et économique. Les travaux de recherche dont les résultats ont été publiés indiquent un fort penchant pour des études de cas visant de plus petites collectivités, surtout les collectivités du Nunavut. Ces études portent principalement sur les incidences négatives du changement climatique, sur les vulnérabilités actuelles et sur la capacité d’adaptation, quoi que des études proposant des possibilités d’intervention adaptative commencent à faire surface. Bien que des études se trouvent à documenter les risques sérieux que pose le changement climatique, elles font également ressortir l’adaptabilité des populations nordiques et les effets des stress politiques et économiques sur la vulnérabilité au climat changeant. Nous avons aussi remarqué l’absence d’études qui examinent comment les gens du Nord peuvent bénéficier des retombées du changement climatique, d’études qui évaluent comment l’interaction des changements climatiques et socioéconomiques futurs (plus précisément en ce qui a trait à la mise en valeur des ressources et à l’amélioration des voies d’expédition) toucheront leur expérience du changement climatique et leur réaction à celui-ci, ou d’études qui discutent des plus grands déterminants de la vulnérabilité et de l’adaptation

The Energetic Particle Detector (EPD) Investigation and the Energetic Ion Spectrometer (EIS) for the Magnetospheric Multiscale (MMS) Mission

Abstract The Energetic Particle Detector (EPD) Investigation is one of 5 fields-and-particles investigations on the Magnetospheric Multiscale (MMS) mission. MMS comprises 4 spacecraft flying in close formation in highly elliptical, near-Earth-equatorial orbits targeting understanding of the fundamental physics of the important physical process called magnetic reconnection using Earth’s magnetosphere as a plasma laboratory. EPD comprises two sensor types, the Energetic Ion Spectrometer (EIS) with one instrument on each of the 4 spacecraft, and the Fly’s Eye Energetic Particle Spectrometer (FEEPS) with 2 instruments on each of the 4 spacecraft. EIS measures energetic ion energy, angle and elemental compositional distributions from a required low energy limit of 20 keV for protons and 45 keV for oxygen ions, up to \u3e0.5 MeV (with capabilities to measure up to \u3e1 MeV). FEEPS measures instantaneous all sky images of energetic electrons from 25 keV to \u3e0.5 MeV, and also measures total ion energy distributions from 45 keV to \u3e0.5 MeV to be used in conjunction with EIS to measure all sky ion distributions. In this report we describe the EPD investigation and the details of the EIS sensor. Specifically we describe EPD-level science objectives, the science and measurement requirements, and the challenges that the EPD team had in meeting these requirements. Here we also describe the design and operation of the EIS instruments, their calibrated performances, and the EIS in-flight and ground operations. Blake et al. (The Flys Eye Energetic Particle Spectrometer (FEEPS) contribution to the Energetic Particle Detector (EPD) investigation of the Magnetospheric Magnetoscale (MMS) Mission, this issue) describe the design and operation of the FEEPS instruments, their calibrated performances, and the FEEPS in-flight and ground operations. The MMS spacecraft will launch in early 2015, and over its 2-year mission will provide comprehensive measurements of magnetic reconnection at Earth’s magnetopause during the 18 months that comprise orbital phase 1, and magnetic reconnection within Earth’s magnetotail during the about 6 months that comprise orbital phase 2

Energetic charged particle fluxes relevant to Ganymede's polar region

The JEDI instrument made measurements of energetic charged particles near Ganymede during a close encounter with that moon. Here we find ion flux levels are similar close to Ganymede itself but outside its magnetosphere and on near wake and open field lines. But energetic electron flux levels are more than a factor of 2 lower on polar and near-wake field lines than on nearby Jovian field lines at all energies reported here. Flux levels are relevant to the weathering of the surface, particularly processes that affect the distribution of ice, since surface brightness has been linked to the open-closed field line boundary. For this reason, we estimate the sputtering rates expected in the polar regions due to energetic heavy ions. Other rates, such as those related to radiolysis by plasma and particles that can reach the surface, need to be added to complete the picture of charged particle weathering

The small GTPase Rab29 is a common regulator of immune synapse assembly and ciliogenesis

Acknowledgements We wish to thank Jorge Galán, Gregory Pazour, Derek Toomre, Giuliano Callaini, Joel Rosenbaum, Alessandra Boletta and Francesco Blasi for generously providing reagents and for productive discussions, and Sonia Grassini for technical assistance. The work was carried out with the financial support of Telethon (GGP11021) and AIRC.Peer reviewedPostprin

Electronic structure, phase stability and chemical bonding in Th2_2Al and Th2_2AlH4_4

We present the results of theoretical investigation on the electronic structure, bonding nature and ground state properties of Th$_2$Al and Th$_2$AlH$_4$ using generalized-gradient-corrected first-principles full-potential density-functional calculations. Th$_2$AlH$_4$ has been reported to violate the "2 \AA rule" of H-H separation in hydrides. From our total energy as well as force-minimization calculations, we found a shortest H-H separation of 1.95 {\AA} in accordance with recent high resolution powder neutron diffraction experiments. When the Th$_2$Al matrix is hydrogenated, the volume expansion is highly anisotropic, which is quite opposite to other hydrides having the same crystal structure. The bonding nature of these materials are analyzed from the density of states, crystal-orbital Hamiltonian population and valence-charge-density analyses. Our calculation predicts different nature of bonding for the H atoms along $a$ and $c$. The strongest bonding in Th$_2$AlH$_4$ is between Th and H along $c$ which form dumb-bell shaped H-Th-H subunits. Due to this strong covalent interaction there is very small amount of electrons present between H atoms along $c$ which makes repulsive interaction between the H atoms smaller and this is the precise reason why the 2 {\AA} rule is violated. The large difference in the interatomic distances between the interstitial region where one can accommodate H in the $ac$ and $ab$ planes along with the strong covalent interaction between Th and H are the main reasons for highly anisotropic volume expansion on hydrogenation of Th$_2$Al.Comment: 14 pages, 9 figure

The comitology game: European policymaking with parliamentary involvement

This paper discusses institutional reforms that might strengthen the role of the European Parliament in the policymaking process of the European Union. Using simple game theory, the paper analyzes the working properties of the different implementation procedures that are known as ‘comitology’. The Council of the European Union employs these procedures when it delegates some of its policymaking power to the Commission as part of Union legislation. We show how the balance of power is determined by the current comitology procedures, and how this balance would change if the role of the European Parliament were strengthened in the comitology game

An empirical approach to modeling ion production rates in Titan’s ionosphere I: Ion production rates on the dayside and globally

Titan's ionosphere is created when solar photons, energetic magnetospheric electrons or ions, and cosmic rays ionize the neutral atmosphere. Electron densities generated by current theoretical models are much larger than densities measured by instruments on board the Cassini orbiter. This model density overabundance must result either from overproduction or from insufficient loss of ions. This is the first of two papers that examines ion production rates in Titan's ionosphere, for the dayside and nightside ionosphere, respectively. The first (current) paper focuses on dayside ion production rates which are computed using solar ionization sources (photoionization and electron impact ionization by photoelectrons) between 1000 and 1400 km. In addition to theoretical ion production rates, empirical ion production rates are derived from CH4, CH3+, and CH4+ densities measured by the INMS (Ion Neutral Mass Spectrometer) for many Titan passes. The modeled and empirical production rate profiles from measured densities of N2+ and CH4+ are found to be in good agreement (to within 20%) for solar zenith angles between 15 and 90°. This suggests that the overabundance of electrons in theoretical models of Titan's dayside ionosphere is not due to overproduction but to insufficient ion losses

Risk of Subsequent Coronary Heart Disease in Patients Hospitalized for Immune-Mediated Diseases: A Nationwide Follow-Up Study from Sweden

Background: Certain immune-mediated diseases (IMDs), such as rheumatoid arthritis and systemic lupus erythematosus, have been linked to cardiovascular disorders. We examined whether there is an association between 32 different IMDs and risk of subsequent hospitalization for coronary heart disease (CHD) related to coronary atherosclerosis in a nationwide follow up study in Sweden. Methods and Findings: All individuals in Sweden hospitalized with a main diagnosis of an IMD (n = 336,479) without previous or coexisting CHD, between January 1, 1964 and December 31 2008, were followed for first hospitalization for CHD. The reference population was the total population of Sweden. Standardized incidence ratios (SIRs) for CHD were calculated. Overall risk of CHD during the first year after hospitalization for an IMD was 2.92 (95 % CI 2.84–2.99). Twentyseven of the 32 IMDs studied were associated with an increased risk of CHD during the first year after hospitalization. The overall risk of CHD decreased over time, from 1.75 after 1–5 years (95 % CI 1.73–1.78), to 1.43 after 5–10 years (95 % CI 1.41– 1.46) and 1.28 after 10+ years (95 % CI 1.26–1.30). Females generally had higher SIRs than males. The IMDs for which the SIRs of CDH were highest during the first year after hospitalization included chorea minor 6.98 (95 % CI 1.32–20.65), systemic lupus erythematosus 4.94 (95 % CI 4.15–5.83), rheumatic fever 4.65 (95 % CI 3.53–6.01), Hashimoto’s thyroiditis 4.30 (95 % CI 3.87–4.75), polymyositis/dermatomyositis 3.81 (95 % CI 2.62–5.35), polyarteritis nodosa 3.81 (95 % CI 2.72–5.19), rheumatoi