Migration, Transfers and Child Labor

We examine agricultural child labor in the context of emigration, transfers, and the abil-ity to hire outside labor. We start by developing a theoretical background based on Basu and Van, (1998), Basu, (1999) and Epstein and Kahana (2008) and show how hiring labor from outside the household and transfers to the household might induce a re-duction in children’s working hours. Analysis using Living Standards Measurement Survey (LSMS) data on the Kagera region in Tanzania lend support to the hypothesis that both emigration and remittances reduce child labor.child labor, emigration, transfers, Tanzania

Structures and waves in a nonlinear heat-conducting medium

The paper is an overview of the main contributions of a Bulgarian team of researchers to the problem of finding the possible structures and waves in the open nonlinear heat conducting medium, described by a reaction-diffusion equation. Being posed and actively worked out by the Russian school of A. A. Samarskii and S.P. Kurdyumov since the seventies of the last century, this problem still contains open and challenging questions.Comment: 23 pages, 13 figures, the final publication will appear in Springer Proceedings in Mathematics and Statistics, Numerical Methods for PDEs: Theory, Algorithms and their Application

Dynamics of nearly spherical vesicles in an external flow

We analytically derive an equation describing vesicle evolution in a fluid where some stationary flow is excited regarding that the vesicle shape is close to a sphere. A character of the evolution is governed by two dimensionless parameters, $S$ and $\Lambda$, depending on the vesicle excess area, viscosity contrast, membrane viscosity, strength of the flow, bending module, and ratio of the elongation and rotation components of the flow. We establish the ``phase diagram'' of the system on the $S-\Lambda$ plane: we find curves corresponding to the tank-treading to tumbling transition (described by the saddle-node bifurcation) and to the tank-treading to trembling transition (described by the Hopf bifurcation).Comment: 4 pages, 1 figur

Highly efficient broadband polarization retarders and tunable polarization filters made of composite stacks of ordinary wave plates

By using the formal analogy between the evolution of the state vector in quantum mechanics and the Jones vector in polarization optics, we construct and demonstrate experimentally efficient broadband half-wave polarization retarders and tunable narrowband polarization filters. Both the broadband retarders and the filters are constructed by the same set of stacked standard multi-order optical wave plates rotated at different angles with respect to their fast polarization axes: for a certain set of angles this device behaves as a broadband polarization retarder while for another set of angles it turns into a narrowband polarization filter. We demonstrate that the transmission profile of our filter can be centered around any desired wavelength in a certain vicinity of the design wavelength of the wave plates solely by selecting appropriate rotation angles

Prediction of sanding in subsurface hydrocarbon reservoirs.

Sand production in oil and gas wells can occur if the fluid velocity exceeds a certain value. Due to drilling operations, the mechanical stresses can exceed the load bearing capacity of the rock. As the local stresses exceed certain level, a certain amount of rock is fractured into sand. Then, the sand is carried by the fluid through the wellbore depending on the flow rate. The amount of the solids can be less than a few grams per cubic meter of reservoir fluid or an essential amount. In the later case erosion of the rock and removing sufficient quantities of rock can occur. This can produce subsurface cavities which collapse and destroy the well. When sanding is unavoidable it is necessary to estimate the characteristics of the process. Our aim was to generate a simple one-dimensional local model, which predicts the volume of sanding, the radius and the porosity of the yielded zone. Such model will help the company in the development of complex 3D models

Where to work?: The role of the household in explaining gender differences in labour market outcomes

With the use of panel data constructed from the 1995 and 1997 Bulgarian Integrated Household Surveys, this paper explores the sectoral reallocation of labour by gender. In Bulgaria, men and women started the transition on an almost equal standing, allowing us to concentrate our attention on the impact of individual and household characteristics in explaining gender differences in the labour market. We find that household characteristics, rather than alternative explanations such as differences in individual characteristics or pure gender discrimination, better explain the observed gender differences in labour market outcomes

Where to work? The role of the household in explaining gender differences in labour market outcomes

With the use of panel data constructed from the 1995 and 1997 Bulgarian Integrated Household Surveys, this paper explores the sectoral reallocation of labour by gender. In Bulgaria, men and women started the transition on an almost equal standing, allowing us to concentrate our attention on the impact of individual and household characteristics in explaining gender differences in the labour market. We find that household characteristics, rather than alternative explanations such as differences in individual characteristics or pure gender discrimination, better explain the observed gender differences in labour market outcomes

Migration, transfers and child labor

We examine agricultural child labor in the context of emigration, transfers, and the ability to hire outside labor. We start by developing a theoretical background based on Basu and Van, (1998), Basu, (1999) and Epstein and Kahana (2008) and show how hiring labor from outside the household and transfers to the household might induce a reduction in children's working hours. Analysis using Living Standards Measurement Survey (LSMS) data on the Kagera region in Tanzania lend support to the hypothesis that both emigration and remittances reduce child labor

Potensi Bakteri Endofit Dalam Meningkatkan Pertumbuhan Tanaman Tembakau Yang Terinfeksi Nematoda Puru Akar (Meloidogyne Spp.)

Potensi Bakteri Endofit dalam Meningkatkan Pertumbuhan Tanaman Tembakau yang Terinfeksi Nematoda Puru Akar (Meloidogyne spp.). Nematoda puru akar (Meloidogyne spp.) pada tanaman tembakau merupakan penyakit penting yang dihadapi oleh perkebunan tembakau di Indonesia. Beberapa teknik pengendalian telah dilakukan, seperti penggunaan nematisida, kultur teknis dan penambahan bahan organik namun belum efektif mengendalikan patogen ini. Pengendalian biologi dengan bakteri endofit merupakan alternatif pengendalian Meloidogyne spp. Penelitian ini bertujuan untuk mendapatkan bakteri endofit asal akar nilam meningkatkan pertumbuhan tanaman tembakau yang terinfeksi nematoda puru akar (Meloidogyne spp.). Penelitian ini dilaksanakan di Laboratorium Penyakit Tumbuhan Fakultas Pertanian Universitas Sumatera Utara pada bulan Juli – Desember 2014. Penelitian ini menggunakan Rancangan Acak Lengkap nonfaktorial dengan perlakuan pemberian beberapa jenis bakteri endofit yaitu: Kontrol (diaplikasikan nematoda 500ekor/pot), Bacillus spp.1, Pseudomonas spp. dan Bacillus spp.2. Hasil penelitian menunjukan laju pertumbuhan dan pertambahan jumlah daun terbaik terdapat pada perlakuan Pseudomonas spp. sedangkan berat basah dan kering akar tertinggi terdapat pada tanaman yang diaplikasikan Bacillus spp 1