A novel behavioral model of the pasture-based dairy cow from GPS data using data mining and machine learning techniques.

A better understanding of the behavior of individual grazing dairy cattle will assist in improving productivity and welfare. Global positioning systems (GPS) applied to cows could provide a means of monitoring grazing herds while overcoming the substantial efforts required for manual observation. Any model of behavioral prediction using GPS needs to be accurate and robust by accounting for inter-cow variation as well as atmospheric effects. We evaluated the performance using a series of machine learning algorithms on GPS data collected from 40 pasture-based dairy cows over 4 mo. A feature extraction step was performed on the collected raw GPS data, which resulted in 43 different attributes. The evaluated behaviors were grazing, resting, and walking. Classifier learners were built using 10 times 10-fold cross validation and tested on an independent test set. Results were evaluated using a variety of statistical significance tests across all parameters. We found that final model selection depended upon level of performance and model complexity. The classifier learner deemed most suitable for this particular problem was JRip, a rule-based learner (classification accuracy=0.85; false positive rate=0.10; F-measure=0.76; area under the receiver operating curve=0.87). This model will be used in further studies to assess the behavior and welfare of pasture-based dairy cows.

Use of a human acellular dermal wound matrix in patients with complex wounds and comorbidities.

OBJECTIVE: Rising prevalence of obesity and uncontrolled diabetes mellitus has resulted in an increasing number of patients with multiple comorbidities who require treatment for chronic complex wounds. Because patients with diabetes and foot ulcers may have a higher risk for amputations, techniques that facilitate complex wound healing and prevent limb amputation are desirable. Here, we investigate a limb preservation strategy that includes application of a human acellular dermal wound matrix (HADWM). METHOD: Medical history, physical examination and full wound assessment were completed for all patients. Systemic antibiotics and appropriate offloading were prescribed as needed. Wounds were debrided to create a bleeding bone and/or wound base for HADWM (Graftjacket regenerative tissue matrix, Wright Medical Technology, Inc., licensed by KCI, an Acelity company, San Antonio, TX). Healing progress was monitored over four weeks with weekly postoperative visits. 'Healed' was defined as full epithelialisation without drainage. RESULTS: Lower extremity ulcers, 16 in 13 patients, were treated with HADWM between May 2004 and July 2013. The median patient age was 76 years (range: 38-90). The average number of comorbidities was three per patient, while 6 (46%) patients had ≥4 comorbidities. Diabetes mellitus (92%) and peripheral vascular disease (77%) were the two most common. All 16 (100%) wounds healed without complications. There were no recurrences in the 11 wounds of the nine patients available for follow-up. Of these patients two had previously advised to receive major leg amputations retained functional limbs. CONCLUSION: The results in this small study reflect our practice's 10-year experience using HADWM as part of a limb preservation strategy.

Associations between daily mortality in London and combined oxidant capacity, ozone and nitrogen dioxide.

Both nitrogen dioxide (NO2) and ozone (O3) are powerful oxidants in ambient air that are intimately linked through atmospheric chemistry and which continuously interchange over very short timescales. Based upon atmospheric chemistry alone, there is a strong, a priori, reason for considering O3 and NO2 together in epidemiological studies, rather than either of the two pollutants separately in single-pollutant models. This paper compares two approaches to this, using Ox, defined as O3 + NO2, as a single metric and also using O3 and NO2 together in two-pollutant models. We hypothesised that the magnitude of the association between Ox and daily mortality would be greater than for NO2 and O3 individually. Using collocated hourly measurements for O3 and NO2 in London, from 2000 to 2005, we carried out a time series analysis of daily mortality. We investigated O3, NO2 and Ox individually in single-pollutant Poisson regression models and NO2 and O3 jointly in two-pollutant models in both all-year and season-specific analyses. We observed larger associations for mean 24-h concentrations of Ox (1.30 % increase in mortality per 10 ppb) than for O3 (0.87 %) and NO2 (0 %) individually. However, when analysed jointly in two-pollutant models, associations for O3 (1.54 %) and NO2 (1.07 %) were comparable to the Ox association. Season-specific analyses broadly followed this pattern irrespective of whether the Ox concentrations were driven by O3 production (summer) or depletion (winter). This novel approach in air pollution epidemiology captures the simultaneous impact of both oxidants whilst avoiding many of the statistical issues associated with two-pollutant models and potentially simplifies health impact calculations.

Spatial epidemiology of Escherichia coli O157:H7 in dairy cattle in relation to night roosts Of Sturnus vulgaris (European Starling) in Ohio, USA (2007-2009).

The goal of our study was to use spatial scan statics to determine whether the night roosts of European starlings (Sturnus vulgaris) act as point sources for the dissemination of Escherichia coli O157:H7 among dairy farms. From 2007 to 2009, we collected bovine faecal samples (n = 9000) and starling gastrointestinal contents (n = 430) from 150 dairy farms in northeastern Ohio, USA. Isolates of E. coli O157:H7 recovered from these samples were subtyped using multilocus variable-number tandem repeat analysis (MLVA). Generated MLVA types were used to construct a dendrogram based on a categorical multistate coefficient and unweighted pair-group method with arithmetic mean (UPGMA). Using a focused spatial scan statistic, we identified statistically significant spatial clusters among dairy farms surrounding starling night roosts, with an increased prevalence of E. coli O157:H7-positive bovine faecal pats, increased diversity of distinguishable MLVA types and a greater number of isolates with MLVA types from bovine-starling clades versus bovine-only clades. Thus, our findings are compatible with the hypothesis that starlings have a role in the dissemination of E. coli O157:H7 among dairy farms, and further research into starling management is warranted.

Genome sequence of Edwardsiella ictaluri 93-146, a strain associated with a natural channel catfish outbreak of enteric septicemia of catfish.

Edwardsiella ictaluri is the cause of extensive mortalities and economic losses to the channel catfish industry of the southeast United States. Here we report the complete genome of Edwardsiella ictaluri 93-146. Whole-genome sequence analysis of E. ictaluri provides a tool for understanding the genomic regions specific to the species and the Edwardsiella genus.

Multiple-locus variable-nucleotide tandem repeat subtype analysis implicates European starlings as biological vectors for Escherichia coli O157:H7 in Ohio, USA.

AIMS: To provide molecular epidemiological evidence of avian transmission of Escherichia coli O157:H7 between dairy farms in Ohio, this study was designed to identify genetic relatedness between isolates originating from bovine faecal samples and intestinal contents of European starlings captured on these farms. METHODS AND RESULTS: During a three-year period (2007-2009), cattle (n = 9000) and starlings (n = 430) on 150 different dairy farms in northern Ohio were sampled for the presence of E. coli O157:H7. Isolates were subjected to multiple-locus variable-nucleotide tandem repeat analysis (MLVA). Distinct allelic groups were identified on most farms; however, isolates clustering into three MLVA groups originated from both cattle and birds on different farms. CONCLUSIONS: Sharing of indistinguishable epidemiologically linked E. coli O157 MLVA subtypes between starlings and cattle on different farms supports the hypothesis that these birds contribute to the transmission of E. coli O157:H7 between dairy farms. SIGNIFICANCE AND IMPACT OF STUDY: A continued need exists to identify and to improve preharvest measures for controlling E. coli O157:H7. Controlling wildlife intrusion, particularly European starlings, on livestock operations, may be an important strategy for reducing dissemination of E. coli O157:H7 between farms and thereby potentially decreasing the on-farm prevalence of E. coli O157:H7 and enhancing the safety of the food supply.

A novel method of detection and classification of motor nerve late-wave activity.

In motor nerve conduction studies, important diagnostic information is provided by the late-wave responses, comprised of F-waves, A-waves, and repeaters. Late-waves in addition to contamination from power line interference and baseline disturbance, are of low amplitude and random in nature. This makes computer-based analysis of late-wave activity very challenging, especially the computer-based F-wave onset latency assignment. Currently available algorithms assign latency independently on a trace-by-trace basis without considering the information present in an entire ensemble of traces. A novel algorithm that takes into account the ensemble information for segmenting and classifying regions of late-wave data is described in this paper, which in turn can be used to improve the performance of computer-based F-wave onset latency assignment.

Verification of an Edwardsiella ictaluri-specific diagnostic PCR.

AIMS: To verify the specificity of a PCR assay for the identification and diagnosis of Edwardsiella ictaluri. METHODS AND RESULTS: An Edwardsiella ictaluri-specific PCR assay was developed utilizing two features of the ribosomal DNA gene clusters. The first feature is the presence of two ribosomal gene clusters located in tandem to one another (the inter-ribosomal spacer, IRS). This characteristic is present in the Edwardsiella genus but absent in the other sequenced members of the Enterobacteriaceae. The second feature is the presence of an intervening sequence (IVS) in the 23S rRNA gene of Edw. ictaluri. To verify the specificity of this assay, we tested genomic DNA from a variety of bacterial species. The IVS/IRS PCR assay results in an c. 2000-bp product from all Edw. ictaluri isolates tested, but not from any other species including Edwardsiella tarda. CONCLUSIONS: The IVS/IRS PCR assay is highly specific for Edw. ictaluri and useful as a tool for identifying this pathogen. SIGNIFICANCE AND IMPACT OF THE STUDY: This research verifies the specificity of PCR-based assay for Edw. Ictaluri, and we describe this assay as a highly versatile diagnostic tool for its identification.

Emotional intimacy predicts condom use: findings in a group at high sexually transmitted disease risk.

Previous studies have reported an inverse relationship between condom use and emotional intimacy. The aim of this study was to determine the relationship between condom use and emotional intimacy. The study was a gonorrhoea case-comparison study with the samples being drawn from public health clinics (cases) and select bars/nightclubs (places) of Houston, TX (n = 215). Data were collected by questionnaires administered on a laptop computer. The majority of respondents were African-American (97.7%), women (69.3%) and had either high school or GED education (72.6%). Condom use with the last sexual partner was analysed along with intimacy with that partner assessed on a 3-point scale. Analysis showed that higher intimacy was related to greater condom use which was significant in men but not in women. In conclusion, these data were opposite to those of previous studies, which showed an inverse relationship between condom use and emotional intimacy. We hypothesize that in a high-risk environment, people exert more effort in protecting those they feel closer to. These data suggest a need to further explore the complex relationship between emotional intimacy and condom use.

Internet based HIV prevention research targeting rural MSM: feasibility, acceptability, and preliminary efficacy.

Internet delivered primary prevention interventions for HIV risk reduction present significant challenges. Changing lifestyle behaviors, such as beginning to use condoms, is difficult and men seeking dates on line may want to avoid thinking about HIV risk which may lead to low initiation and high dropout rates. Many Internet delivered HIV risk reduction programs have mimicked face-to-face outreach programs, failing to take advantage of the Internet's capabilities or did not conduct evaluation. This study focuses on examining the feasibility, acceptability, and efficacy of an Internet delivered HIV risk reduction program for rural men who have sex with men (MSM). The program included online recruiting, three intervention modules, each with two sessions, online questionnaires. The intervention was developed based on iterative research and the Information-Motivation-Behavioral skills model. Participants (N = 475) were randomly assigned to one of six module orders and data were collected automatically at pre-test and after each module. Data supports the feasibility and acceptability of the program as demonstrated by good retention and rapid program completion. Knowledge, self-efficacy, outcome expectancies and motivation increase in a dose response fashion. Post-intervention behavior changes included reduced anal sex and significant increases in condom use. Limitations include a short follow-up period, a predominantly young white rural sample, and the lack of an attention control. Overall the results of the study provide support for the efficacy of Internet-based interventions to reduce risk of HIV infection. Results also support traditional research methods to evaluate HIV prevention programs delivered exclusively through the Internet.

Personal and partner measures in stages of consistent condom use among African-American heterosexual crack cocaine smokers.

Participants' personal condom use measures and those of their last sex partner's were examined in five stages of change for consistent condom use among 449 urban sexually active, heterosexual, African-American crack smokers. The measures included participants' personal and their last sex partner's perceived responsibility, personal and perceived negative attitudes, and participants' self-efficacy to use condoms. The relationships between the measures and the stages were examined using analyses of variance and multivariate logistic regression. Over 90% of participants did not use condoms, consistently. Two-thirds of the inconsistent users were in the precontemplation stage. The rest were equally divided between the contemplation and preparation stages. Personal responsibility outperformed other measures in initial intention to become a regular condom user; partner's perceived responsibility dominated continued intention and actual consistent condom use. Negative attitudes and self-efficacies had strong relationships to the stages of consistent condom use in univariate analyses but these relationships became substantially weaker when the responsibility, attitude, and self-efficacy concepts were entered simultaneously into multivariate analyses.

Associations among correlates of schedule adherence to antiretroviral therapy (ART): a path analysis of a sample of crack cocaine using sexually active African-Americans with HIV infection.

Adherence to HIV medication regimens is a function of multiple dimensions including psychological functioning, social support, adherence self-efficacy and optimism regarding treatment. Active substance use can also negatively affect adherence. An understanding of the nature of the associations among the correlates of adherence can better inform the design of interventions to improve adherence. This study developed an exploratory path model of schedule adherence using data from a sample 130 African-American HIV-positive crack cocaine users on highly active antiretroviral therapy (ART). This model was based on the Transactional Model of Stress and Coping developed by Lazarus and Folkman. Following the theory, the effects of psychological distress on schedule adherence were mediated by patients' relationship with their doctor and optimism towards antiretroviral treatment. Adherence was also associated with patients' self-efficacy regarding their medical regimen which, in turn, was associated with their social support.

Characterization of the rrn operons in the channel catfish pathogen Edwardsiella ictaluri.

AIMS: To advance diagnostics and phylogenetics of Edwardsiella ictaluri by sequencing and characterizing its rrn operons. METHODS AND RESULTS: The Edw. ictaluri rrn operons were identified from a 5-7 kbp insert lambda library and from Edw. ictaluri fosmid clones. We present the complete sequences and analysis of all eight Edw. ictaluri rrn operons and unique regions located upstream and downstream. Two rrn operons were located in tandem with 169 bp separating them, which is apparently a conserved feature between Edw. ictaluri and Edwardsiella tarda. I-CeuI enzyme digestion of Edw. ictaluri genomic DNA and analysis by pulsed field gel electrophoresis indicated that rrn operon number and chromosomal locations are conserved within the species Edw. ictaluri. CONCLUSIONS: The rrn operons of Edw. ictaluri have similar structure and flanking regions compared with other members of the family Enterobacteriaceae; however, the presence of eight copies of the rrn operon makes Edw. ictaluri unique within the family. SIGNIFICANCE AND IMPACT OF THE STUDY: This research clarifies previous phylogenetic analyses of Edw. ictaluri and provides support for the Edw. ictaluri genome sequencing project. In addition, we identified a unique feature of two rrn operons that shows potential for the development of a diagnostic PCR method.

Process, efficacy and sample demographics of three approaches to behavioural surveillance for gonorrhoea: case interviews, place surveys, and network studies.

We investigated the process and time required to collect 450 interviews in a project to determine the most efficacious behavioural surveillance approaches to detect changes in gonorrhoea prevalence. In total, 150 respondents were recruited in each method. For each of place surveys (bars), gonorrhoea case interviews, and network studies based on seeds from the case and place interviews, we determined the recruitment rate and process. Urine testing for gonorrhoea and chlamydia took place in the place interviews. We present data from Houston, Texas that illustrate the sample characteristics, recruitment rates, and, where appropriate, infection rates. Data indicate that there was high uptake and a rapid recruitment rate from the place surveys, an intermediate rate from the network studies, and that the gonorrhoea case interviews were the most inefficient accrual method for behavioural surveillance. Sample characteristics and biases in each method are described, and conclusions drawn for the relative efficacy of each method for gonorrhoea behavioural surveillance.

Tuberculosis infection in drug users: interferon-gamma release assay performance.

SETTING: An inner city neighborhood in Houston, Texas, known for a high rate of drug use. OBJECTIVE: To determine the prevalence of latent tuberculosis infection (LTBI) using the QuantiFERON-TB Gold (QFT-G) test, the TSPOT.TB test and the tuberculin skin test (TST) in drug users and to evaluate the performance of the QFT-G and TSPOT.TB tests vs. the TST. DESIGN: Cross-sectional study. Bivariate and multivariate logistic regression analyses were used to determine risks associated with each test outcome. RESULTS: The prevalence of LTBI in 119 drug users studied was 28% by TST and 34% by QFT-G and T-SPOT.TB. Kappa statistics indicated fair to moderate concordance between QFT-G and TSPOT.TB vs. TST. About one-fifth of the population that tested negative with TST was positive with either QFT-G or T-SPOT.TB. On multivariate analysis, the likelihood of testing QFT-positive or T-SPOT.TB-positive increased by 8% and 6%, respectively, for every year of age; TST positivity was associated with smoking crack at home; being Caucasian or having a history of alcohol use was positively associated with a positive T-SPOT.TB test. CONCLUSION: Interferon-gamma release assays (IGRAs) are superior to the TST in drug users with a higher prevalence of LTBI. Future studies need to assess the predictive value of IGRAs on the progression from LTBI to active TB in high-risk populations.

The impact of HIV-related interventions on HIV risk behavior in a community sample of African American crack cocaine users.

While there are reports of the impact of specific interventions designed to reduce HIV drug and sexual risk behaviors, there are few reports of the impact of HIV interventions in a community-based sample. We report on baseline data from a sample of African American crack smokers who were about to participate in an intervention designed to reduce HIV-related risk behaviors. The majority were male (80%), single (70%) and homeless (52%). Data indicated that 29% of the sample had been in a previous HIV intervention in the past 12 months, the majority in a correctional setting or CBO program. There were few systematic demographic differences between the two groups. Those who had been in an intervention reported using male and female condoms significantly more frequently on all measures of condom use, had positive condom use outcome expectations for male condoms and higher affective and situational condom-related self-efficacy beliefs. These data suggest that, at a community level, the spectrum of HIV risk-reduction programs does produce a significant improvement in condom use and related cognitions, although there is a need to cover a greater proportion of the population. Previous exposure to interventions must be a critical covariate in assessing the impact of future interventions.

Responsibility as a dimension of HIV prevention normative beliefs: measurement in three drug-using samples.

The concept of responsibility was derived originally from principles of morality, as part of a network of rights, duties and obligations. HIV risk-related studies have suggested that a sense of responsibility for condom use to protect a partner is a potentially important predictor of condom use in drug-using populations. We created a four-item scale measuring Self responsibility to use condoms and Partner's responsibility to use condoms. Data were collected from three drug-using samples: crack smokers, HIV seropositive crack smokers in an intervention study in Houston, Texas, and Tanzanian heroin users in Dar es Salaam. Data indicated that the four responsibility items had high alpha coefficients in each sample, and that there were moderate to high intercorrelations between equivalent self and partner responsibility items. There were significant differences in scale scores between the crack smokers and the HIV positive crack smokers and the Tanzanian samples, but no significant differences between the HIV positive and Tanzanian samples. Comparing within the first crack-smoker sample those who were HIV positive and negative showed significant differences in the direction of higher beliefs in responsibility to use condoms in the HIV positive group. These data suggest that responsibility is measurable, holds similar psychometric properties across three samples differing in culture and HIV serostatus, and that condom use responsibility is conceptualized as a measure of general responsibility rather than as a reciprocal self/partner responsibility.

Heroin and HIV risk in Dar es Salaam, Tanzania: youth hangouts, mageto and injecting practices.

HIV risk through needle sharing is now an emerging phenomenon in Africa. This article describes the practices that heroin users are producing as they establish the rules and organization surrounding their drug use. Their practices and interactions reveal the ways that they become initiated into its use, how they progress to injecting, and the important role of local neighbourhood hangouts in facilitating this process. Their practices, interactions and narratives also provide insights into what may be the most appropriate HIV-prevention interventions. Semi-structured interviews were conducted during the months of February and July 2003 with 51 male and female injectors residing in 8 neighbourhoods in the Dar es Salaam, Tanzania. Interviews were content coded and codes were collapsed into emergent themes around hangout places, initiation of heroin use, and progression to injecting. Interviews reveal that Dar es Salaam injectors begin smoking heroin in hangout areas with their friends, either because of peer pressure, desire, or trickery. One hangout place in particular, referred to as the 'geto' (ghetto) is the main place where the organization and rules governing heroin use are produced. Three main types of heroin 'ghettoes' are operating in Dar es Salaam. As users build a tolerance for the drug they move along a continuum of practices until they begin to inject. Injecting heroin is a comparatively recent practice in Africa and coincides with: (1) Tanzania transitioning to becoming a heroin consuming community; (2) the growing importance of youth culture; (3) the technical innovation of injecting practices and the introduction and ease of use of white heroin; and (4) heroin smokers, sniffers, and inhalers perceived need to escalate their use through a more effective and satisfying form of heroin ingestion.