Crisis in Latin America : infrastructure investment, employment and the expectations of stimulus

Infrastructure investment is a central part of the stimulus plans of the Latin American and the Caribbean (LAC) region as it confronts the growing financial crisis. This paper estimates the potential effects on direct, indirect, and induced employment for different types of infrastructure projects with LAC-specific variables. The analysis finds that the direct and indirect short-term employment generation potential of infrastructure capital investment projects may be considerable - averaging around 40,000 annual jobs per US$1billion in LAC, depending upon such variables as the mix of subsectors in the investment program; the technologies deployed; local wages for skilled and unskilled labor; and the degrees of leakages to imported inputs. While these numbers do not account for substitution effect, they are built around an assumed"basket"of investments that crosses infrastructure sectors most of which are not employment-maximizing. Albeit limited in scope, rural road maintenance projects may employ 200,000 to 500,000 annualized direct jobs for every US$1billion spent. The paper also describes the potential risks to effective infrastructure investment in an environment of crisis including sorting and planning contradictions, delayed implementation and impact, affordability, and corruption.Transport Economics Policy&Planning,,Banks&Banking Reform,Non Bank Financial Institutions,Debt Markets

Solving the woolly mammoth conundrum: amino acid 15N-enrichment suggests a distinct forage or habitat

Understanding woolly mammoth ecology is key to understanding Pleistocene community dynamics and evaluating the roles of human hunting and climate change in late Quaternary megafaunal extinctions. Previous isotopic studies of mammoths’ diet and physiology have been hampered by the ‘mammoth conundrum’: woolly mammoths have anomalously high collagen δ15N values, which are more similar to coeval carnivores than herbivores and which could imply a distinct diet and (or) habitat, or a physiological adaptation. We analyzed individual amino acids from collagen of adult woolly mammoths and coeval species and discovered greater  15N enrichment in source amino acids of woolly mammoths than in most other herbivores or carnivores. Woolly mammoths consumed an isotopically distinct food source, reflective of extreme aridity, dung fertilization and (or) plant selection. This dietary signal suggests that woolly mammoths occupied a distinct habitat or forage niche relative to other Pleistocene herbivores

Wild horses in a ‘European wilderness’: imagining sustainable development in the post-Communist countryside

When the Soviet Union and its satellite regimes collapsed, they bequeathed to successor states an unexpected dual legacy: an outsized, backward agrarian sector on the one hand and a wealth of undeveloped nature, rich in biological diversity, on the other. Popular perceptions of the region centre on nightmarish images of environmental devastation, but environmentalists on both sides of the former ‘Iron Curtain’ are increasingly recognizing the unintended benefits to nature of Communist underdevelopment. Eight of the post-Communist states have now consummated their long-awaited ‘return to Europe’, but as they begin a new era as European Union members, they confront a critical developmental challenge. Faced with declining agricultural prospects and growing Western interest in Eastern nature, what to do with a large and underemployed rural population and an everexpanding area of marginal farmland? This article contributes to a growing literature on the political ecology of post-Communist transformation in the ‘Second World’ through a case study from Latvia. At Lake Pape, the Latvian program office of WWF International has implemented a Western-funded project in ecosystem restoration and eco-tourism promotion involving introduction of wild horses in a remote but ecologically rich coastal wetland area. I explore diverse Latvian responses to the polysemic Western narratives of sustainable rural development and biodiversity conservation that have been borne into Eastern Europe along with Western aid monies. Local mediation of these narratives is shaped by the struggle between competing ‘agrarian’ and ‘internationalist’ understandings of national geography, identity and developmental destiny that have structured cultural and political discourse since the emergence of Latvian nationalism 150 years ago

A Review of Three-Family Grand Unified String Models

We review the construction and classification of three-family grand unified models within the framework of asymmetric orbifolds in perturbative heterotic superstring. We give a detailed survey of all such models which is organized to aid analysis of their phenomenological properties. We compute tree-level superpotentials for these models. These superpotentials are used to analyze the issues of proton stability (doublet-triplet splitting and R-parity violating terms) and Yukawa mass matrices. To have agreement with phenomenological data all these models seem to require certain degree of fine-tuning. We also analyze the possible patterns of supersymmetry breaking in these models. We find that the supersymmetry breaking scale comes out either too high to explain the electroweak hierarchy problem, or below the electroweak scale unless some degree of fine-tuning is involved. Thus, none of the models at hand seem to be phenomenologically flawless.Comment: 49 pages, Revtex 3.0; one ps figure included. To appear in the Review section of Int.J.Mod.Phy

Numerical study of the transition of the four dimensional Random Field Ising Model

We study numerically the region above the critical temperature of the four dimensional Random Field Ising Model. Using a cluster dynamic we measure the connected and disconnected magnetic susceptibility and the connected and disconnected overlap susceptibility. We use a bimodal distribution of the field with $h_R=0.35T$ for all temperatures and a lattice size L=16. Through a least-square fit we determine the critical exponents $\gamma$ and $\bar{\gamma}$. We find the magnetic susceptibility and the overlap susceptibility diverge at two different temperatures. This is coherent with the existence of a glassy phase above $T_c$. Accordingly with other simulations we find $\bar{\gamma}=2\gamma$. In this case we have a scaling theory with two indipendet critical exponentsComment: 10 pages, 2 figures, Late

Electron-hydrogen scattering in Faddeev-Merkuriev integral equation approach

Electron-hydrogen scattering is studied in the Faddeev-Merkuriev integral equation approach. The equations are solved by using the Coulomb-Sturmian separable expansion technique. We present $S$- and $P$-wave scattering and reactions cross sections up to the $H(n=4)$ threshold.Comment: 2 eps figure

Existence and approximation of Hunt processes associated with generalized Dirichlet forms

We show that any strictly quasi-regular generalized Dirichlet form that satisfies the mild structural condition D3 is associated to a Hunt process, and that the associated Hunt process can be approximated by a sequence of multivariate Poisson processes. This also gives a new proof for the existence of a Hunt process associated to a strictly quasi-regular generalized Dirichlet form that satisfies SD3 and extends all previous results.Comment: Revised, shortened and improved versio

Lysophosphatidic acid signaling promotes proliferation, differentiation, and cell survival in rat growth plate chondrocytes

AbstractGrowth plate cartilage is responsible for long bone growth in children and adolescents and is regulated by vitamin D metabolites in a cell zone-specific manner. Resting zone chondrocytes (RC cells) are regulated by 24,25-dihydroxyvitamin D3 via a phospholipase D-dependent pathway, suggesting downstream phospholipid metabolites are involved. In this study, we showed that 24R,25(OH)2D3 stimulates rat costochondral RC chondrocytes to release lysophosphatidic acid (LPA) and, therefore sought to determine the role of LPA signaling in these cells. RC cells expressed the G-protein coupled receptors LPA1–5 and peroxisome proliferator-activated receptor gamma (PPAR-γ). LPA and the LPA1/3 selective agonist OMPT increased proliferation and two maturation markers, alkaline phosphatase activity and [35S]-sulfate incorporation. LPA and 24R,25(OH)2D3's effects were inhibited by the LPA1/3 selective antagonist VPC32183(S). Furthermore, apoptosis induced by either inorganic phosphate or chelerythrine was attenuated by LPA, based on DNA fragmentation, TUNEL staining, caspase-3 activity, and Bcl-2:Bax protein ratio. LPA prevented apoptotic signaling by decreasing the abundance, nuclear localization, and transcriptional activity of the tumor-suppressor p53. LPA treatment also regulated the expression of the p53-target genes Bcl-2 and Bax to enhance cell survival. Collectively, these data suggest that LPA promotes differentiation and survival in RC chondrocytes, demonstrating a novel physiological function of LPA-signaling