Short communication: Survey of animal-borne pathogens in the farm environment of 13 dairy operations

A survey was conducted on 13 dairies to determine the occurrence of 5 animal-borne pathogens (Salmonella enterica, Escherichia coli O157:H7, Campylobacter jejuni, Mycobacterium avium ssp. paratuberculosis, and Cryptosporidium parvum) and their distributions across farm elements (feces, bedding, milk filters, stored manure, field soil, and stream water). Presence of C. parvum was measured only in feces and stored manure. All but one farm were positive for at least one pathogen species, and 5 farms were positive for 3 species. Escherichia coli O157:H7 was detected on 6 farms and in all farm elements, including milk filters. Mycobacterium avium ssp. paratuberculosis was detected on 10 of 13 farms and in all farm elements except for milk filters. Salmonella enterica and C. jejuni were detected at lower frequencies and were not identified in soil, stream water, or milk filters on any of the 13 farms. Cryptosporidium parvum was detected in feces but not in stored manure. Stored manure had the highest occurrence of pathogens (73%), followed by feces (50%), milk filters, bedding, soil, and water (range from 23 to 31%). Association of pathogen presence with farm management factors was examined by t-test; however, the small number of study farms and samples may limit the scope of inference of the associations. Pathogens had a higher prevalence in maternity pen bedding than in calf bedding, but total pathogen occurrence did not differ in calf compared with lactating cow feces or in soils with or without manure incorporation. Herd size and animal density did not appear to have a consistent effect on pathogen occurrence. The extent of pathogen prevalence and distribution on the farms indicates considerable public health risks associated with not only milk and meat consumption and direct animal contact, but also potential dissemination of the pathogens into the agroecosystem.     

Effects of aging on efficiency of task switching in a variant of the Trail Making Test.

The Trail Making Test [TMT, R. M. Reitan, (see record 1960-00397-001), 1992] is extensively used in research in neuropsychology and in aging, in part because it has been postulated to reflect executive processes, such as planning and switching. However, neurocognitive and individual-difference based analyses of this test are complicated because of different spatial arrangements of targets, the use of letters only in Version B, and potential order effects when Version A is administered prior to Version B. The present article examines a variant of a TMT (called the Connections Test) that attempts to remedy these deficiencies. A structural equation model suggested that there were no direct effects of age on either the nonalternating or alternating versions of the Connections Test (analogous to TMT Versions A and B, respectively); rather, all age-related effects were mediated through effects on perceptual speed. Moreover, although the nonalternating and alternating versions were strongly related to one another, only the latter had significant independent relations with measures of higher order cognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Introduction of Wide-Band Communications in the Telecommunications Network

An increasing demand for digital wide-band business communications has been emerging as a new driving force in the evolution of the telecommunication network. In parallel with this demand, new transmission, multiplexing, and switching technologies are becoming available to support the implementation of attractive end-to-end wide-band services. This paper looks at the application opportunities of wide-band technologies in the telecommunication network for both near and longer term use, and discusses key implementation and evolution issues. The paper also defines a wide-band channel structure plan as a basis for wide-band ISDN standardization.     

A reasonably practical XUV laser for applications

We describe a laboratory-scale 109 nm Xe Auger laser pumped by an all-commercial high-repetition-rate Nd:YAG laser system. The Xe laser provides pulse energies up to 1 μJ, and an average flux of 3×10 ¹² photons/s at 11.5 eV. Measurements of the gain, output energy, and output beam shape are reported, along with an investigation of the time dependence of the gain     

Superconductivity above 100K in compounds containing Hg

Several members of a new family of (Hg,Tl)(Ba,Sr)CaCuO high temperature superconductors have been synthesized. These compounds, which are analogs to the Hg-Ba-Ca- and Tl-Ba-Ca-layered cuprates, are multi-phased and have superconducting transition temperatures above 100K. Several samples with a nominal composition of HgTl₂Ba₄Ca₄Cu₆O_y had T_cs near 130K. Details of the characterization of these samples are presented.     

Hierarchical NTSC compatible HDTV system architecture — A North American perspective

High definition television (HDTV) has become a major world-wide event in the television arena. Since the early 1980s, when HDTV was first demonstrated by Japan, a number of alternative systems have emerged. These systems clearly reflect the business and political objectives of the particular countries or organizations. In North America, which is the largest single consumer market in the world, technical, business and political considerations are shaping the evolution of HDTV. This paper describes a possible advanced television (ATV) architecture for North America and defines its functional modules and corresponding interfaces. The developed model is recommended as a design tool for standardizing ATV in North America and analysing interrelationships of the functional modules on the economic basis. The paper proposes an ‘hierarchical’ ATV emission system with full NTSC compatibility and HDTV quality. Solutions are recommended for terrestrial broadcast, CATV and satellite. This work describes a total systems approach to HDTV called HDS-NA (high definition system for North America). The two emission signals of HDS-NA: HDMAC-60 and HDNTSC are characterized. RF alternatives for the terrestrial broadcast of HDTV are also discussed.     

Automated method for identifying and prioritizing project risk factors

This paper describes an approach for automatically determining project risk factors based on answers to an interactive questionnaire. Stored knowledge of complex interrelationships is used to transform qualitative inputs into quantitative factors used to rank and compare identified risks. A tool called the Software Technology Risk Advisor is described which implements these techniques and provides a testbed for further refinement.     

Color indicator of cuprate superconductivity observed by polarized light microscopy

A common mineralogical technique for identifying individual crystals in a heterogeneous, polycrystalline sample involves the observation at room temperature of their colors in reflected polarized light (colors of polarization). Here we present the observation that a brownish yellow (golden) color of polarization is not only characteristic of the YBa₂Cu₃O₇ superconductor, but of the cuprate superconductors in general and is correlated with the occurrence of superconductivity.