Multiparticle States and the Hadron Spectrum on the Lattice

The Clebsch-Gordan decomposition is calculated for direct products of the irreducible representations of the cubic space group. These results are used to identify multiparticle states which appear in the hadron spectrum on the lattice. Consideration of the cubic space group indicates how combinations of both zero momentum and non-zero momentum multiparticle states contribute to the spectrum.Comment: v2) Little groups for lattice momenta corrected. Includes a more consistent labeling scheme. (13 pages

SOUTHERNMOST OCCURRENCE OF THE SUWANNEE COOTER, PSEUDEMYS CONCINNA SUWANNIENSIS (TESTUDINES: EMYDIDAE)

The Suwannee Cooter, Pseudemys concinna suwanniensis, the largest member of the speciose turtle family Emydidae, inhabits a small number of rivers that drain into the northeastern Gulf of Mexico along the northwest coast of Florida from just west of Tallahassee to just south of Tampa. The status of this state-protected subspecies in the southernmost of these rivers, the Alafia, is unknown and hence of conservation concern. We provide recent evidence confirming that a reproducing population still exists in this river, and review available specimens and both published and unpublished records documenting the southern limit of distribution. At least within the eastern United States, our observations also extend confirmed knowledge of the geographic occurrence of hatchling turtles overwintering in the nest southward by 285 km

The Human Thioesterase II Protein Binds to a Site on HIV-1 Nef Critical for CD4 Down-regulation

A HIV-1 Nef affinity column was used to purify a 35-kDa Nef-interacting protein from T-cell lysates. The 35-kDa protein was identified by peptide microsequence analysis as the human thioesterase II (hTE) enzyme, an enzyme previously identified in a yeast two-hybrid screen as a potential Nef-interacting protein. Immunofluorescence studies showed that hTE localizes to peroxisomes and that coexpression of Nef and hTE leads to relocalization of Nef to peroxisomes. Interaction of Nef and hTE was abolished by point mutations in Nef at residues Asp108, Leu112, Phe121, Pro122, and Asp123. All of these mutations also abrogated the ability of Nef to down-regulate CD4 from the surface of HIV-infected cells. Based on the x-ray and NMR structures of Nef, these residues define a surface on Nef critical for CD4 down-regulation. A subset of these mutations also affected the ability of Nef to down-regulate major histocompatibility complex class I. These results, taken together with previous studies, identify a region on Nef critical for most of its known functions. However, not all Nef alleles bind to hTE with high affinity, so the role of hTE during HIV infection remains uncertain

Multi-Gain-Stage InGaAs Avalanche Photodiode with Enhanced Gain and Reduced Excess Noise

We report the design, fabrication, and test of an InGaAs avalanche photodiode (APD) for 950-1650 nm wavelength sensing applications. The APD is grown by molecular beam epitaxy on InP substrates from lattice-matched InGaAs and InAlAs alloys. Avalanche multiplication inside the APD occurs in a series of asymmetric gain stages whose layer ordering acts to enhance the rate of electron-initiated impact ionization and to suppress the rate of hole-initiated ionization when operated at low gain. The multiplication stages are cascaded in series, interposed with carrier relaxation layers in which the electric field is low, preventing avalanche feedback between stages. These measures result in much lower excess multiplication noise and stable linear-mode operation at much higher avalanche gain than is characteristic of APDs fabricated from the same semiconductor alloys in bulk. The noise suppression mechanism is analyzed by simulations of impact ionization spatial distribution and gain statistics, and measurements on APDs implementing the design are presented. The devices employing this design are demonstrated to operate at linear-mode gain in excess of 6000 without avalanche breakdown. Excess noise characterized by an effective impact ionization rate ratio below 0.04 were measured at gains over 1000

Analysis of the Socio-Environmental Impacts of the Sierra del Divisor transportation infrastructure in Peru and Brazil

Located in the remote southwestern Amazon, the Sierra del Divisor mountain range divides the Ucayali and Jurua Watersheds and separates the urban centers of Pucallpa, Peru and Cruzeiro do Sul, Brazil. Both Pucallpa and Cruzeiro do Sul serve as economic hubs for their region, but are each the end of the road, as beyond them rivers remain the main means of transportation (figure 1). The Sierra del Divisor region includes indigenous territories, forestry and mining concessions, a reserve for the “uncontacted” Isconahua people, the Serra do Divisor national park in Brazil, and a proposed Peruvian national park, currently the Sierra del Divisor reserved zone: a transitional category (figure 1). The Brazilian Park embraces the Peruvian border and hosts a “spectacular” number of rare and endemic species (Vriesendorp et al. 2006), including jaguar, white-lipped peccaries and the red Uakari monkey (Salisbury et al. 2013). In addition to fauna and flora, the region also holds cultural diversity with descendants of the Asheninka, Nawa people, rubber tappers, and the “uncontacted” Isconahua people. Indigenous communities and small villages line the rivers. In the last decade, loggers, miners, and drug traffickers have become more visible, even as populations in both cities continues to grow (Salisbury et al. 2013). Simultaneously, plans to bridge the ecologically and culturally diverse region between the cities with transportation infrastructure continue to coalesce.https://scholarship.richmond.edu/geography-posters/1002/thumbnail.jp

Narwhal hunting by Pond Inlet Inuit: An analysis of foraging mode in the floe-edge environment

The harvesting of narwhals by Baffin Island Inuit represents an important relationship in terms of the continuous utilization of an indigenous marine resource. However, research on Inuit hunting with respect to narwhals has been mainly confined to harvest counts despite the major role narwhals play in the local northern Baffin subsistence system. The present research examines Pond Inlet Inuit foraging behaviour for narwhals in the spring floe-edge environment. While sea ice is one of the most dominant features of the arctic marine environment for much of any year, it is in the spring that the dynamism of its physical and biological characteristics is most notable. This was especially evident at the fast ice-open water interface, or floe-edge, where rapid physical change in the condition of the ice is frequent and summer migratory marine mammals and birds are present in large numbers. In this paper, analysis of 14 observed hunts indicates that Inuit utilization of the spring floe edge for narwhal hunting, in contrast to most other hunt types, follows a sit-and-wait mode of foraging. The study also explicates aspects of Pond Inlet hunters traditional ecological knowledge necessary to travel and conduct harvesting operations successfully in this complex environment.La chasse au narval par les Inuit de la Terre de Baffin représente une relation importante en terme d’une utilisation continue d’une ressource marine indigène. Cependant, la recherche portant sur la chasse au narval par les Inuit a surtout été limitée aux dénombrements des récoltes, malgré le rôle majeur que les narvals jouent dans le système local de subsistance. La présente recherche explore le comportement alimentaire des Inuit face aux narvals dans l’environnement printanier de la lisière des banquises (floe-edge). Tandis que la glace marine est l’aspect dominant de l’environnement arctique marin pendant la majeure partie de l’année, c’est au printemps que le dynamisme de ses caractéristiques physiques et biologiques est le plus notable. Ceci est particulièrement évident à l’interface rapide de la glace et des eaux dégagées, nommément la lisière des banquises, où le changement physique rapide dans la condition de la glace est fréquent et où les mammifères marins et les oiseaux migrateurs estivaux sont présents en grand nombre. Dans cet article, une analyse de 14 voyages observés indique que l’utilisation par les Inuit de la lisière des banquises au printemps pour chasser le narval, comparativement aux autres types de chasse, suit un mode de chasse à l’affût (sit-and-wait). Cette étude expose les aspects du savoir écologique traditionnel appartenant aux Inuit de Pond Inlet, nécessaire pour voyager et conduire les opérations de chasse avec succès dans cet environnement complexe

The Financial Collapse Of The Milwaukee Public Museum

The 123-year old Milwaukee Public Museum, which had long been considered to be one of the top natural history museums in the country, found itself in dire financial straights in 2005. The museum had run large deficits for the past three years and had almost entirely eaten through its cash and long-term endowment. In June 2005 it was forced to lay off many of its experienced collections and research staff and had begun the process of preparing to sell off assets that were not a part of the “exhibit experience.”  Milwaukee County’s Chief Executive went so far as to suggest that the Museum’s celebrated 700-acre Tirimbina rain forest preserve in Costa Rica should be sold. How did this once renowned organization become a shell of its former self? What financial management and governance mistakes were made, if any, and how could this disaster have been prevented

The Diminishing Benefits Of Nae International Portfolio Diversification Following The 1997 Asian Financial Crisis

Nae international diversification has been fundamental to portfolio management over the past 30 years, but the benefits appear to be significantly diminished following the 1997 Asian financial crisis. Using monthly return data covering the period from 1970 through 2004, we found rising correlations between U.S. and international equity markets exceeding 0.85 since July 1997. Even the return correlation of emerging countries recently has reached almost 0.80. We also found a significant reduction in the variance of the international return correlation after the financial crisis. Portfolio managers should not expect to receive the same benefits from international portfolio diversification as that obtained prior to the Asian financial crisis