Scalar Quantum Field Theory with Cubic Interaction

In this paper it is shown that an i phi^3 field theory is a physically acceptable field theory model (the spectrum is positive and the theory is unitary). The demonstration rests on the perturbative construction of a linear operator C, which is needed to define the Hilbert space inner product. The C operator is a new, time-independent observable in PT-symmetric quantum field theory.Comment: Corrected expressions in equations (20) and (21

Annotated Checklist of Mammals of the Yucatán Peninsula, México. II. Rodentia

The Yucatán Peninsula, as encompassed in this series of papers, includes the Mexican states of Campeche and Yucatán, and the Federal Territory of Quintana Roo. This region is a low-lying plain that rises gently in elevation from north to south. It is surrounded on three sides by water and bounded on the south by British Honduras (i.e. Belize), Guatemala, and the Mexican state of Tabasco. The vegetation of the peninsula increases in height from north to south and from the coast inland. Generally, forest to the north is xerophilic, but that of the southern part of the peninsula is tall, quasi rainforest. Although the mammalian fauna of the Yucatán Peninsula is unique in many ways, there has been no comprehensive account of mammals of the region since Gaumer\u27s (1917) Monografía de los mamíferos de Yucatán. In an earlier paper of this series (Jones, et al., 1973), the chiropteran fauna of the peninsular region was treated. The present report deals exclusively with rodents, 20 native species of which (and two that have been introduced) presently are known from the Yucatán Peninsula. These 22 species represent 16 genera of seven families as follows: Sciuridae, two; Geomyidae, one; Heteromyidae, two; Cricetidae, 12; Muridae, two (introduced); Dasyproctidae, two; and Erethizontidae, one. One genus (Otonyctomys) is endemic to the peninsula, as are four species (Sciurus yucatanicus, Heteromys gaumeri, Peromyscus yucatanicus, and Reithrodontomys spectabilisi and a number of subspecies. This report is based principally upon material housed in the Museum of Natural History at the University of Kansas. In the summer of 1962, two field parties from Kansas visited the region, one consisting of W.E. Duellman and six students enrolled in a field course in vertebrate zoology, and the other including the senior author and four students working on a survey of terrestrial vertebrates and their ectoparasites under the aegis of a contract (DA-49-193MD- 2215) from the U.S. Army Research and Development Command. Also, Percy L. Clifton, field representative of the Museum of Natural History, collected mammals on the peninsula from mid-December 1962 until June 1963. Collections from which specimens were examined are: Museum of Natural History at The University of Kansas, the American Museum of Natural History, the British Museum (Natural History), the University of Michigan Museum of Zoology, the Museum, Texas Tech University, and the National Museum of Natural History. Most localities mentioned in text are plotted in a map. Ectoparasites obtained from our material from the Yucatán Peninsula have been reported by Emerson (1971), Genoways (1973), Lawlor (1965, 1969), Loomis (1969), and Price and Emerson (1971)

Parkinson\u27s Disease in Louisiana, 1999-2012: Based on Hospital Primary Discharge Diagnoses, Incidence, and Risk in Relation to Local Agricultural Crops, Pesticides, and Aquifer Recharge

The two major causes of Parkinson\u27s disease (PD) are genetic susceptibility and exposure to agricultural pesticides. Access to 23,224 individuals\u27 hospital primary discharge diagnoses of PD allowed the mapping of cases against known crop distributions and pesticides. Our main objective was to map PD risks (cases per 10,000 people) against crops and their pesticides. The ZIP Code address locations, and the 2000 and 2010 census data, were used to map the risks of PD throughout Louisiana and in relation to United States Department of Agriculture (USDA)-recorded crops. The introduction of glyphosate-resistant crops appears to have initiated the PD disappearance from northeastern parishes on the west bank of the Mississippi river. Rice and sugar cane are seemingly unassociated with PD, as is the Mississippi itself, except for Jefferson and St. Charles Parishes, which are essentially urban or industrial. The present major PD-affected areas are associated with commercial forests, woodlands, and pastures, and thus with certain arbor-pastoral pesticides, 2,4-D, chlorpyrifos, and paraquat. Human populations at maximum risk are those living in areas of moderate and high aquifer-recharge potential. The levels of estimated pesticide exposure in these recharge areas we were able to access were of variable use, but significant amounts of 2,4-D were being used

Research activity among UK social work academics

Summary: The research activity of social work academics in the UK has been of interest and concern amongst academics and research funders. Multiple initiatives have been implemented to develop social work research activity, yet research by social work academics remains limited, hindered by lack of time, support infrastructures, funding and training. Through the use of a mixed-methods cross-sectional survey (N = 200) and follow-up individual interviews (N = 11), this study reports on the factors that were found to contribute to or impede the amount of time that social work academics reported spending on research. Findings: The results from the survey indicated that 73% of respondents were research active. Bivariate analysis revealed that academics spent less time on research and teaching, and more time on administration than expected by their employing universities. Multivariate analysis found that less time spent on administration and teaching, more university supports, and being from a pre-1992 university predicted more time spent on research. Applications: The findings indicate that the administrative burdens associated with teaching and assessment in social work education result in academics struggling to fit research into their busy lives, despite initiatives to raise the profile and productivity of social work research. Research support infrastructures and strategies should be reviewed in light of such findings

Bacillus anthracis diversity in Kruger National Park [South Africa]

The Kruger National Park (KNP), South Africa, has a recorded history of periodic anthrax epidemics causing widespread disease among wild animals. Bacillus anthracis is the causative agent of anthrax, a disease primarily affecting ungulate herbivores. Worldwide there is little diversity among B. anthracis isolates, but examination of variable-number tandem repeat (VNTR) loci has identified six major clones, with the most dissimilar types split into the A and B branches. Both the A and B types are found in southern Africa, giving this region the greatest genetic diversity of B. anthracis worldwide. Consequently, southern Africa has been hypothesized to be the geographic origin of B. anthracis. In this study, the genotypic types of 98 KNP B. anthracis isolates were identified using multiple-locus VNTR analysis. Two major types are evident, the A branch and the B branch. The spatial and temporal distribution of the different genotypes indicates that anthrax epidemic foci are independent, though correlated through environmental cues. Kruger B isolates were found on significantly higher-calcium and higher-pH soils than were Kruger type A. This relationship between genotype and soil chemistry may be due to adaptive differences among divergent anthrax strains. While this association may be simply fortuitous, adaptation of A types to diverse environmental conditions is consistent with their greater geographic dispersal and genetic dissimilarity

Experimental habitat fragmentation disrupts nematode infections in Australian skinks

Habitat conversion and fragmentation threaten biodiversity and disrupt species interactions. While parasites are recognized as ecologically important, the impacts of fragmentation on parasitism are poorly understood relative to other species interactions. This lack of understanding is in part due to confounding landscape factors that accompany fragmentation. Fragmentation experiments provide the opportunity to fill this knowledge gap by mechanistically testing how fragmentation affects parasitism while controlling landscape factors. In a large‐scale, long‐term experiment, we asked how fragmentation affects a host–parasite interaction between a skink and a parasitic nematode, which is trophically transmitted via a terrestrial amphipod intermediate host. We expected that previously observed amphipod declines resulting from fragmentation would result in decreased transmission of nematodes to skinks. In agreement, we found that nematodes were absent among skinks in the cleared matrix and that infections in fragments were about one quarter of those in continuous forest. Amphipods found in gut contents of skinks and collected from pitfall traps mirrored this pattern. A structural equation model supported the expectation that fragmentation disrupted this interaction by altering the abundance of amphipods and suggested that other variables are likely also important in mediating this effect. These findings advance understanding of how landscape change affects parasitism.This work was funded by an NSF Postdoctoral Research Fellowship in Biology (1309192) to J. Resasco and NSF funding to K. F. Davies (DEB-0841892

The global distribution of Bacillus anthracis and associated anthrax risk to humans, livestock and wildlife.

Bacillus anthracis is a spore-forming, Gram-positive bacterium responsible for anthrax, an acute infection that most significantly affects grazing livestock and wild ungulates, but also poses a threat to human health. The geographic extent of B. anthracis is poorly understood, despite multi-decade research on anthrax epizootic and epidemic dynamics; many countries have limited or inadequate surveillance systems, even within known endemic regions. Here, we compile a global occurrence dataset of human, livestock and wildlife anthrax outbreaks. With these records, we use boosted regression trees to produce a map of the global distribution of B. anthracis as a proxy for anthrax risk. We estimate that 1.83 billion people (95% credible interval (CI): 0.59-4.16 billion) live within regions of anthrax risk, but most of that population faces little occupational exposure. More informatively, a global total of 63.8 million poor livestock keepers (95% CI: 17.5-168.6 million) and 1.1 billion livestock (95% CI: 0.4-2.3 billion) live within vulnerable regions. Human and livestock vulnerability are both concentrated in rural rainfed systems throughout arid and temperate land across Eurasia, Africa and North America. We conclude by mapping where anthrax risk could disrupt sensitive conservation efforts for wild ungulates that coincide with anthrax-prone landscapes

Cm-Wavelength Total Flux and Linear Polarization Properties of Radio-Loud BL Lacertae Objects

Results from a long-term program to quantify the range of behavior of the cm-wavelength total flux and linear polarization variability properties of a sample of 41 radio-loud BL Lac objects using weekly to tri-monthly observations with the University of Michigan 26-m telescope operating at 14.5, 8.0, and 4.8 GHz are presented; these observations are used to identify class-dependent differences between these BL Lacs and QSOs in the Pearson-Readhead sample. The BL Lacs are found to be more highly variable in total flux density than the QSOs, exhibiting changes that are often nearly-simultaneous and of comparable amplitude at 14.5 and 4.8 GHz in contrast to the behavior in the QSOs and supporting the existence of class-dependent differences in opacity within the parsec-scale jet flows. Structure function analyses of the flux observations quantify that a characteristic timescale is identifiable in only 1/3 of the BL Lacs. The time-averaged fractional linear polarizations are only on the order of a few percent and are consistent with the presence of tangled magnetic fields within the emitting regions. In many sources a preferred long-term orientation of the EVPA is present; when compared with the VLBI structural axis, no preferred position angle difference is identified. The polarized flux typically exhibits variability with timescales of months to a few years and shows the signature of a propagating shock during several resolved outbursts. The observations indicate that the source emission is predominately due to evolving source components and support the occurrence of more frequent shock formation in BL Lac parsec-scale flows than in QSO jets. The differences in variability behavior and polarization between BL Lacs and QSOs can be explained by differences in jet stability.Comment: 1 LaTex (aastex) file, 21 postscript figure files, 2 external LaTex table files. To appear in the Astrophysical Journa

The impact of the mixing properties within the Antarctic stratospheric vortex on ozone loss in spring

Calculations of equivalent length from an artificial advected tracer provide new insight into the isentropic transport processes occurring within the Antarctic stratospheric vortex. These calculations show two distinct regions of approximately equal area: a strongly mixed vortex core and a broad ring of weakly mixed air extending out to the vortex boundary. This broad ring of vortex air remains isolated from the core between late winter and midspring. Satellite measurements of stratospheric H2O confirm that the isolation lasts until at least mid-October. A three-dimensional chemical transport model simulation of the Antarctic ozone hole quantifies the ozone loss within this ring and demonstrates its isolation. In contrast to the vortex core, ozone loss in the weakly mixed broad ring is not complete. The reasons are twofold. First, warmer temperatures in the broad ring prevent continuous polar stratospheric cloud (PSC) formation and the associated chemical processing (i.e., the conversion of unreactive chlorine into reactive forms). Second, the isolation prevents ozone-rich air from the broad ring mixing with chemically processed air from the vortex core. If the stratosphere continues to cool, this will lead to increased PSC formation and more complete chemical processing in the broad ring. Despite the expected decline in halocarbons, sensitivity studies suggest that this mechanism will lead to enhanced ozone loss in the weakly mixed region, delaying the future recovery of the ozone hole