Job turnover and labor turnover : a taxonomy of employment dynamics

We present an organized set of stylized facts on the relations among flows of workers,changes in employment and changes in the numer of jobs at the firm level. Job turnover isusually measured by comparing stocks of employment in each firm at two points in time andadding up the absolute employment changes. This measure is a just proxy for true jobturnover because only net job changes are counted. In this paper we use information thatallows us to compare this proxy with the correct measure. We compare both of thesemeasures to a measure of labor turnover that counts movements of individuals into and outof jobs. We find that: 1) The proxy for job turnover does not differ substantially from actualjob turnover; 2) There is a big difference between job turnover and labor turnover. Mostmobility is into and out of existing jobs rather than to created or from destroyed jobs; 3) Alarge fraction of all hires are by firms where employment is declining, and a large fractionof all layoffs are by firms where employment is expanding; 4) Simultaneous hiring and firingis due to heterogeneity of the work force

Artisanal fishing in Beira, Central Mozambique

The study focuses on artisanal fishing in Beira, located within the most important fishery area of Mozambique - the Sofala Bank in central Mozambique. The main aim is to establish the degree of compliance with artisanal fishing regulations by artisanal fishermen in light of an increasing concern for the impact of fishing on ecosystems and livelihoods. Qualitative research data was gathered through semi-structured interviews with fishermen, officials from the Department of Fisheries and major stakeholders from the Institute for the Development of Small Scale Fisheries (IDSSF), the National Institute for Fishery Research (NIFR) and the Community Fishing Centres (CFCs). Though a review of the regulations and policies for the management of artisanal fishing in Mozambique indicate that they are well formulated and relevant, there is little to no compliance by the practitioners of artisanal fishing. The data revealed that artisanal fishermen in Beira use types of fishing gear which catches immature and juvenile fish and poses a threat to the health of the marine ecosystems. The most dangerous of these fishing gears are the mosquito net traps (known as “chicocota”) and the beach seine. It is clear that the application and enforcement of the relevant regulations under the right circumstances would lead to better management of the fisheries environment and ensure the sustainability of artisanal fishing.http://www.krepublishers.com02-Journals/JHE/JHE-00-0-000-000-1990-Web/JHE-00-0-000-000-1990-1-Cover.htmam201

Transmission of jaagsiekte (ovine pulmonary adenomatosis) by means of a permanent epithelial cell line established from affected lungs

An epithelial cell line, designated JS-15. 4, has been established in culture from jaagsiekte lesions and subcultured in vitro for almost 2 years. It exhibits morphological and other features of transformed cells and has been shown by electron microscopy to consist of type B ovine alveolar epithelial cells. Jaagsiekte was successfully transmitted to 3 new-born lambs by the intratracheal injection of cells following immunosuppressive treatment with either anti-thymocyte immunoglobulin alone or combined with anti-macrophage immunoglobulin. Incubation periods as short as 10 weeks were recorded. Evidence was also obtained that natural transmission may result from the inhalation of viable cells.The articles have been scanned in colour with a HP scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to final presentyation PDF-Format

Holography and Defect Conformal Field Theories

We develop both the gravity and field theory sides of the Karch-Randall conjecture that the near-horizon description of a certain D5-D3 brane configuration in string theory, realized as AdS_5 x S^5 bisected by an AdS_4 x S^2 "brane", is dual to N=4 Super Yang-Mills theory in R^4 coupled to an R^3 defect. We propose a complete Lagrangian for the field theory dual, a novel "defect superconformal field theory" wherein a subset of the fields of N=4 SYM interacts with a d=3 SU(N) fundamental hypermultiplet on the defect preserving conformal invariance and 8 supercharges. The Kaluza-Klein reduction of wrapped D5 modes on AdS_4 x S^2 leads to towers of short representations of OSp(4|4), and we construct the map to a set of dual gauge-invariant defect operators O_3 possessing integer conformal dimensions. Gravity calculations of and are given. Spacetime and N-dependence matches expectations from dCFT, while the behavior as functions of lambda = g^2 N at strong and weak coupling is generically different. We comment on a class of correlators for which a non-renormalization theorem may still exist. Partial evidence for the conformality of the quantum theory is given, including a complete argument for the special case of a U(1) gauge group. Some weak coupling arguments which illuminate the duality are presented.Comment: 47 pages, LaTeX, 2 figures, feynmf. v2: fixed minor errors, added references. v3: fixed more typo

Superconductor coupled to two Luttinger liquids as an entangler for electron spins

We consider an s-wave superconductor (SC) which is tunnel-coupled to two spatially separated Luttinger liquid (LL) leads. We demonstrate that such a setup acts as an entangler, i.e. it creates spin-singlets of two electrons which are spatially separated, thereby providing a source of electronic Einstein-Podolsky-Rosen pairs. We show that in the presence of a bias voltage, which is smaller than the energy gap in the SC, a stationary current of spin-entangled electrons can flow from the SC to the LL leads due to Andreev tunneling events. We discuss two competing transport channels for Cooper pairs to tunnel from the SC into the LL leads. On the one hand, the coherent tunneling of two electrons into the same LL lead is shown to be suppressed by strong LL correlations compared to single-electron tunneling into a LL. On the other hand, the tunneling of two spin-entangled electrons into different leads is suppressed by the initial spatial separation of the two electrons coming from the same Cooper pair. We show that the latter suppression depends crucially on the effective dimensionality of the SC. We identify a regime of experimental interest in which the separation of two spin-entangled electrons is favored. We determine the decay of the singlet state of two electrons injected into different leads caused by the LL correlations. Although the electron is not a proper quasiparticle of the LL, the spin information can still be transported via the spin density fluctuations produced by the injected spin-entangled electrons.Comment: 15 pages, 2 figure

Art, Virtual Worlds and the Emergent Imagination

This paper presents a framework for the emergent imagination that arises out of the transitional spaces created in avatar-mediated online space. Through four categories of transitional space identified in artworks created in virtual worlds, the paper argues that, as the virtual remains connected to time, the imagination becomes connected to space. The author’s analysis of the imaginative effects of artworks presented in the two virtual (and physical) gallery exhibitions of the Kritical Works in SL project demonstrates a mode of artistic exploitation of the particular combination of user-generated and avatar-mediated space

A New Technology for Stabilization of Biomolecules in Tissues for Combined Histological and Molecular Analyses

For accurate diagnosis, prediction of outcome, and selection of appropriate therapies, the molecular characterization of human diseases requires analysis of a broad spectrum of altered biomolecules, in addition to morphological features, in affected tissues such as tumors. In a high-throughput screening approach, we have developed the PAXgene Tissue System as a novel tissue stabilization technology. Comprehensive characterization of this technology in stabilized and paraffin-embedded human tissues and comparison with snap-frozen tissues revealed excellent preservation of morphology and antigenicity, as well as outstanding integrity of nucleic acids (genomic DNA, miRNA, and mRNA) and phosphoproteins. Importantly, PAXgene-fixed, paraffin-embedded tissues provided RNA quantity and quality not only significantly better than that obtained with neutral buffered formalin, but also similar to that from snap-frozen tissue, which currently represents the gold standard for molecular analyses. The PAXgene tissue stabilization system thus opens new opportunities in a variety of molecular diagnostic and research applications in which the collection of snap-frozen tissue is not feasible for medical, logistic, or ethical reasons. Furthermore, this technology allows performing histopathological analyses together with molecular studies in a single sample, which markedly facilitates direct correlation of morphological disease phenotypes with alterations of nucleic acids and other biomolecules

Crossover from two- to three-dimensional critical behavior for nearly antiferromagnetic itinerant electrons

The crossover from two- to three-dimensional critical behavior of nearly antiferromagnetic itinerant electrons is studied in a regime where the inter-plane single-particle motion of electrons is quantum-mechanically incoherent because of thermal fluctuations. This is a relevant regime for very anisotropic materials like the cuprates. The problem is studied within the Two-Particle Self-Consistent approach (TPSC), that has been previously shown to give a quantitative description of Monte Carlo data for the Hubbard model. It is shown that TPSC belongs to the $n\rightarrow \infty$ limit of the $O\left( n\right)$ universality class. However, contrary to the usual approaches, cutoffs appear naturally in the microscopic TPSC theory so that parameter-free calculations can be done for Hubbard models with arbitrary band structure. A general discussion of universality in the renormalized-classical crossover from $d=2$ to $d=3$ is also given.Comment: Revtex, 23 pages + 6 postcript figures (with epsfile

Spin Stiffness of Mesoscopic Quantum Antiferromagnets

We study the spin stiffness of a one-dimensional quantum antiferromagnet in the whole range of system sizes $L$ and temperatures $T$. We show that for integer and half-odd integer spin case the stiffness differs fundamentally in its $L$ and $T$ dependence, and that in the latter case the stiffness exhibits a striking dependence on the parity of the number of sites. Integer spin chains are treated in terms of the non-linear sigma model, while half-odd integer spin chains are discussed in a renormalization group approach leading to a Luttinger liquid with Aharonov-Bohm type boundary conditions.Comment: 12 pages, LaTe