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The first ground-based experiment to prove the concept of a novel space-based observation technique for microwave and infrared-laser occultation between low-Earth-orbit satellites was performed in the Canary Islands between La Palma and Tenerife. For two nights from 21 to 22 July 2011 the experiment delivered the infrared-laser differential transmission principle for the measurement of greenhouse gases (GHGs) in the free atmosphere. Such global and long-term stable measurements of GHGs, accompanied also by measurements of thermodynamic parameters and line-of-sight wind in a self-calibrating way, have become very important for climate change monitoring. The experiment delivered promising initial data for demonstrating the new observation concept by retrieving volume mixing ratios of GHGs along a ~144 km signal path at altitudes of ~2.4 km. Here, we present a detailed analysis of the measurements, following a recent publication that introduced the experiment's technical setup and first results for an example retrieval of CO2. We present the observational and validation data sets, the latter simultaneously measured at the transmitter and receiver sites; the measurement data handling; and the differential transmission retrieval procedure. We also determine the individual and combined uncertainties influencing the results and present the retrieval results for 12CO2, 13CO2, C18OO, H2O and CH4. The new method is found to have a reliable basis for monitoring of greenhouse gases such as CO2, CH4, and H2O in the free atmosphere.

A new technique for the satellite remote sensing of greenhouse gases in the atmosphere via the absorption of short-wave infrared laser signals transmitted between counter-rotating satellites in low Earth orbit has recently been proposed; this would enable the acquisition of a long-term, stable, global set of altitude-resolved concentration measurements. We present the first ground-based experimental demonstration of this new infrared-laser occultation method, in which the atmospheric absorption of CO2 near 2.1 μm was measured over a ~144 km path length between two peaks in the Canary Islands (at an altitude of ~2.4 km), using relatively low power diode lasers (~4 to 10 mW). The retrieved CO2 volume mixing ratio of 400 ppm (±15 ppm) is consistent within experimental uncertainty with simultaneously recorded in situ validation measurements. We conclude that the new method has a sound basis for monitoring CO2 in the free atmosphere; other greenhouse gases such as methane, nitrous oxide and water vapour can be monitored in the same way.

Films of zinc sulfide (ZnS) have been grown on silicon (Si) substrates by sputtering in argon and either sulfur‐enriched or deficient‐gaseous environments. The density of electron traps at the ZnS/Si heterojunction is invariant with gas. However the photoluminescent intensity increases for films grown in argon enriched with hydrogen sulfide (Ar:H2S) compared with those grown in argon. Furthermore the density of sulfur vacancies is reduced by the presence of H2S, particularly compared with films grown in a mixture of argon and hydrogen (Ar:H). In these latter films sulfur vacancies increase the electrical conductivity by approximately three orders of magnitude. It is expected, therefore, that the high field condition essential for hot‐electron production in thin film electroluminescent devices is optimized in films with a reduced sulfur vacancy content, i.e., grown in Ar:H2S.

This study used a combination of single antigen immunoperoxidase staining for bovine leukaemia virus (BLV) p24 capsid antigen and IgM to enumerate the peripheral blood mononuclear cells (PBMCs) infected with BLV and the number of B-cells, respectively. A significant relationship was found between the number of BLV-infected PBMCs and the number of circulating B-cells. A model was created that predicted the number of circulating B-cells using the number of BLV-infected PBMCs. These data also show that the percentage of B-cells in PBMCs preparations is not affected by 24 h of in vitro culture when LPS is added to the culture medium. Double antigen labelling showed that the majority of circulating B-cells were infected with BLV in some BLV-seropositive cattle that were not persistently lymphocytotic.

Alternating current thin film electroluminescent (EL) devices exhibiting memory with low Mn concentrations have a temperature independent threshold, but a temperature dependent saturation brightness and memory margin. Based upon these observations we argue that EL emission is initiated via the usual tunneling process from interface states, but subsequent characteristics are determined via a second carrier generation process. Shallow donor sites are calculated to exist at a depth of 0.12 eV below the conduction band. These are believed to be involved in the second carrier generation process since brightness‐voltage characteristics are associated with Poole–Frenkel emission.

Thin films of ZnS, with varying concentrations of Zn, have been grown onto p−‐Si using the molecular beam deposition method. By increasing the Zn content, a rise in the conductivity is seen and a peak is achieved. With too much Zn, however, the conductivity reduces quickly. The most conducting film forms an ohmic contact with the p−‐Si substrate. Calculation of the Fermi energy in this device shows that the Fermi level lies at 0.11 eV below the conduction band. The less conducting material is found to form a pseudoSchottky barrier at the p−‐Si interface. The conduction process is thought to occur due to an excess of S vacancies (donor sites) compared to Zn vacancies (acceptor sites). The addition of Zn seems to reduce the effect of autocompensation, usually a hindrance in the fabrication of conducting ZnS films.

Polycrystalline films of ZnS with a slight excess of S have been grown on (100) Si by congruent sublimation from a single Knudsen cell. Intense blue emission is observed at 460 nm from room-temperature photoluminescence studies, and is ascribed to S-Zn vacancies acting as self-activated (SA) centres. The emission is quenched by the addition of Zn from a second Knudsen cell, which also causes the growth of a luminescent peak centred on 678 nm. No reduction in the SA luminescence is seen when co-sublimating ZnS and AgS, implying that it is not possible to remove the S-vacancy completely. Quenching of the blue emission occurs when Mn, instead of Zn, is added to the ZnS films, providing direct evidence of Mn incorporation into Zn vacancies. At the optimum Mn concentration, the intensity of the Mn emission at 580 nm is comparable to the blue emission (460 nm) from the undoped ZnS films.

The standard complement fixation (CF) test, a commercial agarose gel immunodiffusion (AGID) test (ImmuCell Corporation, Portland, Maine), and two commercial enzyme-linked immunosorbent assays (ELISAs; Allied Laboratories, Glenwood Springs, Colo. [Allied ELISA], and the CSL, Limited, [Parkville, Victoria, Australia] enzyme immunoassay [CSL ELISA]) were evaluated by using sera from the Repository for Paratuberculosis Specimens. The case definition of subclinical bovine paratuberculosis was isolation of Mycobacterium paratuberculosis from fecal samples or internal organs of dairy cattle without diarrhea or weight loss. Animals designated as free of the disease originated exclusively from certified paratuberculosis-free herds in Wisconsin. None of the cattle evaluated had been vaccinated for paratuberculosis. Among 177 M. paratuberculosis-infected cattle, the CF test, the AGID test, the Allied ELISA, and the CSL ELISA had test sensitivities of 38.4, 26.6, 58.8, and 43.4%, respectively, and specificities of 99.0, 100.0, 95.4, and 99.0%, respectively. Only 108 of the infected cattle were confirmed by culture or by a commercial DNA probe (IDEXX Corporation, Portland, Maine) to be shedding the organism in fecal samples at the time of serological testing. Among the 108 M. paratuberculosis fecal shedders, the CF test, the AGID test, the Allied ELISA, and the CSL ELISA were positive for 54.6, 40.7, 65.7, and 56.5% of the cows, respectively; and among the 69 cows that were nonshedders, the tests were positive for 14.5, 4.3, 47.8, and 24.6% of the cows, respectively. There was a significant difference (P < 0.05) in the rate of positive test results for all four tests between these two groups of animals. The CF test performed well when it was compared with the other serological tests if a titer of >/- 1.8 was classified as a positive test result.

To evaluate the usefulness of pulsed infrared solid-state Holmium:Yttrium-Aluminum-Garnet (Ho:YAG) laser in neurosurgery, acute responses of brain tissue to Ho:YAG irradiation and to investigate the healing processes in rats and rabbits.Animals were divided into groups according to different survival time and laser irradiation mode. Craniotomy was made and laser energy was delivered to the brain surface by two irradiation modes: 1) contact mode with the fiber in contact with the brain surface; and 2) non-contact mode with the fiber tip 5 mm above the brain surface. Gross observations were made and histological changes were studied.Acute responses were studied on rats' brain. The contact mode produced a crater lined with less than 1 mm thick thermally coagulated layer of brain tissue. The non-contact mode effectively vaporized the brain tissue even with water irrigation. Good homeostatic effect was achieved. The shock waves generated by the pulsed delivery of laser energy, however, impacted on the brain resulting in debris spreading and brain vibration. The healing processes were studied on rabbits' brain one day to six weeks after irradiation. The lesions produced by the contact mode were narrow and sharply defined. With the non-contact mode, the thickness of the coagulated layer at the bottom of the crater varied between 0.8 and 1.1 mm.Ho:YAG laser should be a clinically useful tool in neurosurgery because of its good ablation effect, shallow penetration and convenient optic fiber transmission system. Meanwhile, a continuously waved Ho:YAG laser is desired to reduce the shock wave impact.

Amongst many schemes to relieve curriculum pressure and to allow delivery of a variety of related personal transferable skills and knowledge has been the development of the project-work theme. Here practice amongst course providers has varied considerably. Some have retained the traditional individual `Final-Year' project as the main mechanism; some now include project activity in a variety of formats, as an integrated and developing thread throughout other parts of the curriculum. With the publication of the first draft set of QAA benchmark statements in this subject discipline and extensive debate in the profession relating to the educational formation of electrical engineers, it is felt to be timely that a thorough study of this important teaching and learning method be conducted. This project on the subject of `projects'-hence Project Squared-has the objectives of identifying the desirable learning outcomes of project work in professionally-accredited degree courses, of identifying good practice in the delivery of these learning outcomes and of promoting implementation of these schemes amongst current course providers. The aim is to provide definitive, tried and tested methods of delivering an appropriate student learning experience that harmonises with the benchmarks of academia, professional accreditation and QAA. Although the study has a bias towards final year projects in accredited electrical/electronic engineering degree courses the study evaluates elements of good practice across the entire spectrum of project work in engineering programmes. (5 pages)

To use an on-farm recording form to quantity the effect of specific management practices on apparent prevalence of Mycobacterium paratuberculosis in dairy cattle herds.Epidemiologic survey.26 commercial Wisconsin dairy farms.An instrument was developed on the basis of literature review and expert interviews to quantify on-farm management practices associated with increased apparent prevalence of M paratuberculosis. On-farm visits were conducted to assess how specific management practices were conducted. Apparent prevalence of M paratuberculosis infection was measured for all animals20 months old on all farms, using a commercial ELISA. Regression analysis was used to identify management variables that were significantly associated with apparent prevalence of M paratuberculosis.Regression analysis (R2 = 0.90) identified that high scores for environmental conditions, newborn calf care, grower calf care, bred heifer care, and manure handling were significantly associated with M paratuberculosis apparent prevalence in Wisconsin dairy herds.Environmental conditions, newborn calf care, grower calf management, bred heifer management, and manure handling factors may serve as a prioritized checklist for instructing owners and managers where to place emphasis in changing management practices to limit M paratuberculosis prevalence. Likewise, the factors identified as having low association with apparent prevalence may be de-emphasized in control programs, allowing dairy managers to focus time and finances on more effective components of an M paratuberculosis control program.

We give a definition of the Yagita invariant po(G) of an arbitrary group G, and compute po(GL n (O)) for each prime p, where O is any integrally closed subring of the complex numbers ℂ (i.e., O is integrally closed in its field of fractions F, which is also a subring of ℂ). We also show that po(SL n (O)) is equal to po(GL n (O)) for n ≥ 2 except that possibly po(SL n (O)) is 1/2po (GL n (O)) for some small n and ‘small’ rings O. Our definition of po(G) extends both Yagita’s original definition for G finite [9] and the definition given by one of us for G of finite virtual cohomological dimension (or vcd) [8]. For G of finite vcd such that the Tate-Farrell cohomology Ĥ* (G) of G is p-periodic, po(G) is equal to the p-period. Hence our results may be viewed as a generalisation of those of Biirgisser and Eckmann [1,2], who compute the p-periods of GL n (O) and SL n (O) for various O such that these groups have finite vcd and for all n such that these groups are p-periodic. The methods we use are similar to those used in [1].

An ELISA was developed to detect antibodies to the 41-kd flagellin (P41) of Borrelia burgdorferi in serum obtained from cattle. Absorption studies, immunoblot analysis, immunoelectron microscopy, and correlation of results of the P41-ELISA and the P39-ELISA as well as measurement of the antibody to P41 in calves challenge-exposed with Borrelia theileri were used to assess the specificity of the P41-ELISA. Antigens derived from Escherichia coli, Leptospira interrogans serovar hardjo, and B burgdorferi were used for absorption studies and immunoblot analysis. Antibodies to P41 of B burgdorferi cross-reacted with antigens of E coli, but were not cross-reactive with L hardjo. A value 3 SD higher than the mean of the negative-control population of cattle was defined as the minimum value (cutoff value) for a positive result by the P41-ELISA. Use of this value for classification of test results reduced the predicted rate of false-positive results attributable to E coli cross-reactivity to 1%. Immunoblot analysis revealed that test-positive serum from cattle reacted mainly with 41-, 39-, 34-, and 31-kd proteins of B burgdorferi, as well as several smaller proteins. Immunoelectron microscopy revealed that serum from cattle that was test-positive by the P41-ELISA bound to the flagellin and outer membrane of B burgdorferi. Results of absorption studies, immunoblot analysis, and immunoelectron microscopy were correlated and indicated that serum from cattle that was test-positive by P41-ELISA had stronger reactivity to B burgdorferi antigens than to antigens of E coli or L hardjo.(ABSTRACT TRUNCATED AT 250 WORDS)

A random sample of Wisconsin dairy herds, stratified by herd size, were tested for paratuberculosis by use of an absorbed ELISA procedure. The ELISA was optimized for overall accuracy by means of receiver operating characteristic curve analysis, and had a sensitivity and specificity of 50.9 and 94.9%, respectively. Herd prevalence was analyzed for correlation with responses to a management practices questionnaire completed by the herd owners. One hundred and fifty-eight herds and 4,990 cattle were tested. Of these, 50% of herds and 7.29% of cattle had positive test results. Calculation of true prevalence from the apparent prevalence indicated that 4.79% of cattle and 34% of the Wisconsin dairy herds tested had serologic evidence of paratuberculosis. Among the 54 herds classified as positive on the basis of true prevalence estimation, the mean number of test positive cattle was 20.3%. The geographic distribution of herds with positive results was not uniform. More infected herds were found in the southern and western districts of Wisconsin than in the eastern district. The west-central district had a larger number of infected herds than did other districts. By use of chi 2 analysis, the only management factor found to be significantly associated with herd prevalence was housing of calves after weaning (P = 0.03). Specifically, in herds with higher prevalence, calves were separated after weaning into calf barns and hutches rather than into pens in the cow barn more often than in herds with lower prevalence. This factor was also considered significant by use of logistic regression analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

The frequency of thioguanine-resistant, hypoxanthine phosphoribosyltransferase-deficient lymphocytes in the peripheral blood of human subjects was used to study the genotoxic effects of smoking. Sixty-two nonsmokers and 58 smokers, aged 19 to 45 years with average ages of 30 and 32 years, respectively, and with no other known exposures, were studied using an in vitro assay of the frequency of mutant lymphocyte clones. Analysis of variance explained 68% of the variation in the mutant frequencies. Mutant frequency was dependent upon lymphocyte cloning efficiency, length of smoking history, age, and interactions between these variables. Four nonsmokers and three smokers had high mutant frequencies that were not explained by these variables. Mutant frequencies were inversely related to lymphocyte cloning efficiencies; the effect was twice as great for smokers as for nonsmokers. The time-dependent effect of smoking dominated, with mutant frequency increasing 10%/year of smoking as compared with an independent 1%/year of age. Smoking had a greater effect on young smokers' lymphocytes. Heterogeneity of mutant frequency among both smokers and nonsmokers and its implications for use of lymphocyte mutation assays as biomarkers are discussed.

In order to successfully apply laboratory tests to the solution of clinical problems, a clinician needs to select tests that are appropriate to the suspected disease, collect and submit the necessary specimens, and recognize sources of variation that affect test results. The clinician must have confidence in the accuracy and precision of analytical methods used to produce results. An understanding of reference ranges and test performance in healthy and diseased animals is necessary for accurate interpretation and clinical decision making.

Commercial laying hens were examined microbiologically at necropsy 31 or 42 weeks after aerosol vaccination with the F strain of Mycoplasma gallisepticum (MG). Mycoplasma isolates were studied in Western blots probed with polyclonal antiserum raised in rabbits to F strain immunogen. The persistence of the vaccine strain was demonstrated by detection of a 75-kilodalton immunoreactive protein, which was present in all MG isolates and thought to be a unique marker of the F strain. Use of PCA-F to probe Western blots allowed simultaneous identification of non-MG isolates, non-F strains of MG, and the F strain of MG.

The efficacy of two media, an Edward-type medium (EPJ) and a modified SP4-type medium (SP4-PS), were compared for primary isolation of Mycoplasma gallisepticum (MG) from commercial layer chickens (n = 58) vaccinated with the live F strain of MG. Three groups of chickens that differed in the interval after vaccinal exposure to the F strain (32, 41, and 102 weeks) were studied at necropsy. Mycoplasma isolation was attempted from the trachea, sinus, and cloaca using lavage and swab techniques but was successful only from the trachea and sinus. MG was isolated from 39 (8.4%) of 463 culture attempts from 58 tracheal inocula and 58 sinus inocula. Isolation of MG was successful more frequently using EPJ medium than SP4-PS medium, and isolation occurred more often from the sinus than from the trachea. Of the 58 chickens studied, 19 (33%) were shown by culture to be infected with MG. Isolation was successful only from 32- and 41-week post-vaccination exposure groups. However, all chickens studied were serologically positive for MG antibody by rapid-plate agglutination and hemagglutination-inhibition assays.

An immunobinding assay capable of distinguishing among Mycoplasma synoviae, M. gallisepticum, M. gallopavonis, and M. meleagridis was developed. A low-protein-binding membrane filter served as the solid support, and a 96-well microsample filtration manifold was used. The assay detected 50 ng of mycoplasmal protein, or approximately 3 x 10(4) colony-forming units, from pure or mixed cultures. No cross-reactions were observed among the mycoplasma species tested. The assay was inexpensive, easy to interpret, and required approximately 3 hr to perform. The 96-well format allowed screening of numerous cultures and use of several antisera in a single assay.

This volume is based on lecture courses and seminars given at the LMS Durham Symposium on the geometry of low-dimensional manifolds. This area has been one of intense research recently, with major breakthroughs that have illuminated the way a number of different subjects interact (for example: topology, differential and algebraic geometry and mathematical physics). The workshop brought together a number of distinguished figures to give lecture courses and seminars in these subjects; the volume that has resulted is the only expository source for much of the material, and will be essential for all research workers in geometry and mathematical physics.

The hypothesis that the quality of human relationships is a component in the development of cancer was investigated in a prospective study of former medical students. Findings from two psychological measures are presented: the Closeness to Parents Scale, which showed that students who subsequently developed cancer were more likely to describe a lack of closeness with their parents than their healthy classmates; and the Rorschach Interaction Scale, which demonstrated less satisfactory relationships among male cancer victims as contrasted with the rest of the cohort. The findings suggest that internal self-other representations, as measured by these two tests, are involved as regulators of biologic systems and manifestations of illness, such as cancer.

In a prospective study of 1,046 male medical students, those who later committed suicide showed a heightened sensitivity in stressful situations as assessed by the Habits of Nervous Tension Questionnaire (HNT). Survival analyses specified 2 of the 25 HNT items as the strongest suicide predictors: Irritability (relative risk 5.5; 95% confidence interval 1.76-17.17) and Urinary Frequency (3.3; 1.07-10.32). No other risk factors for suicide emerged from family background measures or individual medical school measures. It appears that types of sensitivity reflect psychological characteristics that are long-term precursors of suicide.

Medical records from 333 cats with diabetes mellitus were studied retrospectively, using epidemiologic methods to determine the incidence of and risk factors for diabetes mellitus in this species. Abstracts were derived, using the Veterinary Medical Data Program with its 17 participating academic institutions in the United States and Canada. A reference population of 135,651 cats was derived from the same hospital population and time span (July 1980 to June 1986). The incidence of diabetes mellitus in cats was determined to be 2.45 cases/1,000 cat-years-of-risk during the 6-year study period. Breed had no detectable effect on risk for diabetes mellitus. In contrast, body weight, age, gender, and neutering had a significant (P less than or equal to 0.01) effect. Body weight of cats was categorized as being less than or greater than or equal to 6.8 kg. The higher body weight, probably indicating obesity, contributed a 2.2-fold increase in risk, even after adjustment for age and gender (adjusted odds ratio). The etiologic fraction for high body weight was 3.8%, suggesting that an estimated 3.8% of cases of diabetes mellitus was attributable to this factor alone. Over 50% of diabetic cats were greater than 10 years old, and the etiologic fraction for age greater than 7 years alone was 73.5%. Age was a significant (P less than 0.001) and the most important single risk factor for development of the disease in cats, with adjusted odds ratios of 8.3 and 14.4 for age 7 to 10 years and greater than 10 years, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)