Long-term trends in the relation between daytime and nighttime values of <I>fo</I>F2

The data from the vertical ionospheric sounding for 12 stations over the world were analyzed to find the relation between the values of <I>fo</I>F2 for 02:00 LT and 14:00 LT of the same day. It is found that, in general, there exists a negative correlation between <I>fo</I>F2(02) and <I>fo</I>F2(14). The value of the correlation coefficient <I>R(fo</I>F2) can be in some cases high enough and reach minus 0.7&ndash;0.8. The value of <I>R(fo</I>F2) demonstrates a well pronounced seasonal variations, the highest negative values being observed at the equinox periods of the year. It is also found that <I>R(fo</I>F2) depends on geomagnetic activity: the magnitude of <I>R(fo</I>F2) is the highest for the choice of only magnetically quiet days (<I>A_p</I>&lt;6), decreasing with the increase of the limiting value of <I>A_p</I>. For a fixed limitation on <I>A_p</I>, the value of <I>R(fo</I>F2) depends also on solar activity. Apparently, the effects found are related to thermospheric winds. Analysis of long series of the vertical sounding data shows that there is a long-term trend in <I>R(fo</I>F2) with a statistically significant increase in the <I>R(fo</I>F2) magnitude after about 1980. Similar analysis is performed for the <I>fo</I>F2(02)/<I>fo</I>F2(14) ratio itself. The ratio also demonstrates a systematic trend after 1980. Both trends are interpreted in terms of long-term changes in thermospheric circulation

Attachment matters

A review of attachment research findings relevant to early years polic

Behind the Curtain

[Excerpt] On August 31, 2004, for the first time, the nation’s mutual fund companies reported how they cast their proxy votes at the public companies in which they invest. The disclosure is the result of Securities and Exchange Commission rules adopted in January 2003, rules that the AFL-CIO first petitioned for in December 2000 and that the mutual fund industry strenuously opposed. This report evaluates how the 10 largest mutual fund families voted when presented with the opportunity to curb CEO pay abuses at a dozen S&P 500 companies in 2004. We chose executive compensation as our benchmark because, in the words of billionaire investor Warren Buffet, “The acid test for reform will be CEO compensation.

Behind the Curtain: How the 10 Largest Mutual Fund Families Voted When Presented with 12 Opportunities to Curb CEO Pay Abuse in 2004

[Excerpt] On August 31, 2004, for the first time, the nation’s mutual fund companies reported how they cast their proxy votes at the public companies in which they invest. The disclosure is the result of Securities and Exchange Commission rules adopted in January 2003, rules that the AFL-CIO first petitioned for in December 2000 and that the mutual fund industry strenuously opposed. This report evaluates how the 10 largest mutual fund families voted when presented with the opportunity to curb CEO pay abuses at a dozen S&P 500 companies in 2004. We chose executive compensation as our benchmark because, in the words of billionaire investor Warren Buffet, “The acid test for reform will be CEO compensation.” We found that, when it comes to voting proxies on proposals involving CEO pay abuses, there is significant variation among fund families. The scores in our survey ranged from a high of 100% for American Century to a low of 20% for Putnam

Relic Right-handed Dirac Neutrinos and Implications for Detection of Cosmic Neutrino Background

It remains to be determined experimentally if massive neutrinos are Majorana or Dirac particles. In this connection, it has been recently suggested that the detection of cosmic neutrino background of left-handed neutrinos $\nu^{}_{\rm L}$ and right-handed antineutrinos $\overline{\nu}^{}_{\rm R}$ in future experiments of neutrino capture on beta-decaying nuclei (e.g., $\nu^{}_e + {^3{\rm H}} \to {^3}{\rm He} + e^-$ for the PTOLEMY experiment) is likely to distinguish between Majorana and Dirac neutrinos, since the capture rate is twice larger in the former case. In this paper, we investigate the possible impact of right-handed neutrinos on the capture rate, assuming that massive neutrinos are Dirac particles and both right-handed neutrinos $\nu^{}_{\rm R}$ and left-handed antineutrinos $\overline{\nu}^{}_{\rm L}$ can be efficiently produced in the early Universe. It turns out that the capture rate can be enhanced at most by $28\%$ due to the presence of relic $\nu^{}_{\rm R}$ and $\overline{\nu}^{}_{\rm L}$ with a total number density of $95~{\rm cm}^{-3}$, which should be compared to the number density $336~{\rm cm}^{-3}$ of cosmic neutrino background. The enhancement has actually been limited by the latest cosmological and astrophysical bounds on the effective number of neutrino generations $N^{}_{\rm eff} = 3.14^{+0.44}_{-0.43}$ at the $95\%$ confidence level. For illustration, two possible scenarios have been proposed for thermal production of right-handed neutrinos in the early Universe.Comment: 16 pages, 4 figure, more discussions added, references updated, to appear in Nucl. Phys.

Predicting the long-term impact of antiretroviral therapy scale-up on population incidence of tuberculosis.

OBJECTIVE: To investigate the impact of antiretroviral therapy (ART) on long-term population-level tuberculosis disease (TB) incidence in sub-Saharan Africa. METHODS: We used a mathematical model to consider the effect of different assumptions about life expectancy and TB risk during long-term ART under alternative scenarios for trends in population HIV incidence and ART coverage. RESULTS: All the scenarios we explored predicted that the widespread introduction of ART would initially reduce population-level TB incidence. However, many modelled scenarios projected a rebound in population-level TB incidence after around 20 years. This rebound was predicted to exceed the TB incidence present before ART scale-up if decreases in HIV incidence during the same period were not sufficiently rapid or if the protective effect of ART on TB was not sustained. Nevertheless, most scenarios predicted a reduction in the cumulative TB incidence when accompanied by a relative decline in HIV incidence of more than 10% each year. CONCLUSIONS: Despite short-term benefits of ART scale-up on population TB incidence in sub-Saharan Africa, longer-term projections raise the possibility of a rebound in TB incidence. This highlights the importance of sustaining good adherence and immunologic response to ART and, crucially, the need for effective HIV preventive interventions, including early widespread implementation of ART

U.S. Government Manual 2008-2009 Edition: Office of Personnel Management

[Excerpt] The Office of Personnel Management administers a merit system to ensure compliance with personnel laws and regulations and assists agencies in recruiting, examining, and promoting people on the basis of their knowledge and skills, regardless of their race, religion, sex, political influence, or other nonmerit factors. Its role is to provide guidance to agencies in operating human resources programs which effectively support their missions and to provide an array of personnel services to applicants and employees. The Office supports Government program managers in their human resources management responsibilities and provides benefits to employees, retirees, employed annuitants, and their survivors

An optimal penalty method for a hyperbolic system modeling the edge plasma transport in a tokamak

The penalization method is used to take account of obstacles, such as the limiter, in a tokamak. Because of the magnetic confinement of the plasma in a tokamak, the transport occurs essentially in the direction parallel to the magnetic field lines. We study a 1D nonlinear hyperbolic system as a simplified model of the plasma transport in the area close to the wall. A penalization which cuts the flux term of the momentum is studied. We show numerically that this penalization creates a Dirac measure at the plasma-limiter interface which prevents us from defining the transport term in the usual distribution sense. Hence, a new penalty method is proposed for this hyperbolic system. For this penalty method, an asymptotic expansion and numerical tests give an optimal rate of convergence without spurious boundary layer. Another two-fields penalization has also been implemented and the numerical convergence analysis when the penalization parameter tends to $0$ reveals the presence of a boundary layer

Using a damper amplification factor to increase energy dissipation in structures

AbstractFluid dampers are an important tool for dissipating unwanted vibrations in a range of engineering structures. This paper examines the effects of amplifying the displacements transferred to a non-linear damper, to increase the effectiveness of the damper in a range of situations commonly encountered in civil engineering structures. These include, (i) the ability to “fine tune” the required damping for a particular size damper, (ii) the ability to have a set of the same size dampers, but with different amplification factors to achieve a specific damping task, and (iii) to increase the sensitivity of the damper to small movements which effectively extends the range over which the damper works. Through numerical simulations and experimental tests conducted on a non-linear damper, we quantify the potential advantages of adding an amplification factor and the range of parameters where the benefit to this device is significant. The example of a two-storey structure is used as a test case and real-time dynamic substructuring tests are used to assess the complete system performance using a range of different amplification factors. The results show that the structural performance is most improved for frequencies close to resonance and that the amplification factor has an effective limit that for the case considered in this study is of approximately 3. The effects of the mechanism compliance are also assessed