HIV/AIDS and time allocation in rural Malawi

AIDS morbidity and mortality are expected to have a large impact on households’ labor supply in rural Malawi since they reduce the time that adults can spend on production for subsistence and on income generating activities. However, the data demands for estimating this impact are high, limiting the amount of empirical evidence. In this paper, we utilize a unique combination of quantitative and qualitative data, including biomarkers for HIV, collected by the Malawi Diffusion and Ideational Change Project, to analyze the impact of AIDS-related morbidity and mortality on time allocation decisions for rural Malawians. We evaluate both the direct effect of HIV/AIDS on the time allocation of affected individuals as well as its indirect effect on the time allocation of surviving household members. We find that the latter is the most important effect of AIDS-related morbidity and mortality, especially on women’s time. Specifically, AIDS induces diversification of income sources, with women reallocating their time from work-intensive (typically farming and heavy chores) to cash-generating tasks (such as casual labor).Africa, AIDS/HIV, economic impact, Malawi, time allocation

Double Parton Scatterings in High-Energy Proton-Nucleus Collisions and Partonic Correlations

The joint study of Double Parton Scatterings, in high energy proton-proton and proton-nucleus collisions, can provide a lot of information on multi-parton correlations. The multi-parton structure is in fact probed in a different way by DPS, in $p$-$p$ and in $p$-$A$ collisions. In $p$-$A$ collisions the interpretation of the experimental results may be however complicated by the presence of interference terms, which are missing in $p$-$p$. A suitable reaction channel, where interference terms are absent, is $WJJ$ production. By studying $WJJ$ production in $p$-$Pb$ collisions, we estimate that the fraction of events due to DPS may be larger by a factor 3 or 4, as compared to $p$-$p$, while the amount of the increased fraction can give a direct indication on the importance of different correlation terms.Comment: 27 pages, 9 figure

Radio recombination lines from obscured quasars with the SKA

We explore the possibility of detecting hydrogen radio recombination lines from 0 < z < 10 quasars. We compute the expected Hnalpha flux densities as a function of absolute magnitude and redshift by considering (i) the range of observed AGN spectral indices from UV to X-ray bands, (ii) secondary ionizations from X-ray photons, and (iii) stimulated emission due to nonthermal radiation. All these effects are important to determine the line fluxes. We find that the combination of slopes: alpha_X,hard = -1.11, alpha_X,soft = -0.7, alpha_EUV = -1.3, alpha_UV = -1.7, maximizes the expected flux, f_Hnalpha = 10 microJy for z = 7 quasars with M_AB = -27 in the n = 50 lines; allowed SED variations produce variations by a factor of 3 around this value. Secondaries boost the line intensity by a factor of 2 to 4, while stimulated emission in high-z quasars with M_AB = -26 provides an extra boost to RRL flux observed at nu = 1 GHz if recombinations arise in HII regions with T_e = 10^3-5 K, n_e = 10^3-5 cm^-3. We compute the sensitivity required for a 5sigma detection of Hnalpha lines using the SKA, finding that the SKA-MID could detect sources with M_AB < -27 (M_AB < -26) at z < 8 (z < 3) in less than 100 hrs of observing time. These observations could open new paths to searches for obscured SMBH progenitors, complementing X-ray, optical/IR and sub-mm surveys.Comment: 11 pages, 9 figures; to be published in Monthly Notices of the Royal Astronomical Society Main Journa

(Co)homology of crossed modules with coefficients in a π1\pi_1-module

We define a cotriple (co)homology of crossed modules with coefficients in a $\pi_1$-module. We prove its general properties, including the connection with the existing cotriple theories on crossed modules. We establish the relationship with the (co)homology of the classifying space of a crossed module and with the cohomology of groups with operators. An example and an application are given.Comment: 32 pages, LaTeX2e, Paul Taylor's diagram package; added reference. Accepted for publication by Homology, Homotopy and Application

Nanoparticles of transition metals oxides with application potential

Tato práce se zabývá nejvíce používanými metodami přípravy a fyzikálními vlastnostmi nanočástic přechodných kovů. Fyzikální vlastnosti nanočástic mohou být kontrolovány pomocí velikosti a tvaru částic. Na velikost částic mají vliv podmínky přípravy. Zabývali jsme se především sol-gelovou metodou, ko-precipitací a mikroemulzí a provedli jsme shrnutí fyzikálních vlastností ZrO2, TiO2, CoFe2O4, které jsou důležitým aspektem pro jejich možné budoucí využití. Vzorky nanočástic kobaltových ferritů zapoudřených v SiO2 matrici, které byly připraveny pomocí modifikované sol-gelové metody, byly charakterizovány pomocí rentgenové difrakce a ICP-OES. Byla určena velikost částic, která byla porovnána s finální žíhací teplotou.We present summary of the most used preparation methods and physical properties of transition metal-based nanoparticles. The physical properties of the nanoparticles can be controlled by particle shape and size that can be affected by conditions of preparation. We mainly described the sol-gel method, co-precipitation and microemulsions method. We summarized physical properties of ZrO2, TiO2 and CoFe2O4 with respect to their possible application. A series of the cobalt ferrite nanoparticles embedded in silica matrix, obtained by modified sol-gel route, was characterized using X-ray diffraction and ICP-OES. We determined the particle diameter and compared them to the final annealing temperature.Ústav aplikované matematiky a fyzikyDokončená práce s úspěšnou obhajobo

Spectrum of a family of operators

Having as start point the classic definitions of resolvent set and spectrum of a linear bounded operator on a Banach space, we introduce the resolvent set and spectrum of a family of linear bounded operators on a Banach space. In addition, we present some results which adapt to asymptotic case the classic results.Comment: 23 page