Preparation and characterisation of silver nanoparticle coated on cellulose paper: evaluation of their potential as antibacterial water filter

This study investigates the ability of cellulose filter paper coated with silver nanoparticles to remove Escherichia coli from drinking water. The cellulose filter paper was coated with silver nanoparticles by a chemical reduction method using two different ratios of sodium borohydride and silver nitrate. In consideration of drinking-water quality standards and non-carcinogenic health risks, the optimum sodium borohydride:silver nitrate ratio for coating the cellulose filter paper was determined by comparing the silver in the effluent after E. coli removal. For both ratios, 100% E. coli removal was realised. In terms of the silver in the effluent, only the first two lowest concentrations for both ratios of sodium borohydride and silver nitrate were compliant with the drinking-water quality standards, demonstrating hazard quotients (HQs) between 0.084 and 0.484. On the basis of the highest level of E. coli removal with the lowest HQ value, the optimum sodium borohydride:silver nitrate ratio for coating the cellulose filter paper as an antibacterial water filter was 2:1 molar ratio (0.002 M:0.001 M). Silver nanoparticle-coated cellulose filter paper was found to be an inexpensive and easy-to-use emergency antibacterial water filter to generate clean drinking water.     

Defining and diagnosing postpartum clinical endometritis and its impact on reproductive performance in dairy cows

The objectives of this study were to validate diagnostic criteria for clinical endometritis in postpartum dairy cows and to measure the impact of endometritis on reproductive performance. Data were collected from 1865 cows in 27 herds, including history of dystocia, twins, retained placenta, or metritis. All cows were examined once between 20 and 33 d in milk (DIM) including external inspection, vaginoscopy, and transrectal palpation of the cervix, uterus, and ovaries. All cows were followed for a minimum of 7 mo or until pregnancy or culling. Survival analysis was used to derive a case definition of endometritis based on factors associated with increased time to pregnancy. The significance of clinical findings depended on the interval postpartum when examination took place. The presence of purulent uterine discharge or cervical diameter > 7.5 cm after 20 DIM, or mucopurulent discharge after 26 DIM identified cows with clinical endometritis. Given vaginoscopy, no diagnostic criteria based on palpation of the uterus had predictive value for time to pregnancy. The prevalence of clinical endometritis was 16.9%. Vaginoscopy was required to identify 44% of these cases. Accounting for parity, herd, and ovarian status, cows with clinical endometritis between 20 and 33 DIM had a hazard ratio of 0.73 for pregnancy (took 27% longer to become pregnant), and were 1.7 times more likely to be culled for reproductive failure than cows without endometritis.     

Purification of Stearidonic Acid from Modified Soybean Oil by Argentation Silica Gel Column Chromatography

The objective of this study was to purify stearidonic acid (SDA, 18:4 ω-3) from modified soybean oil containing a mixture of over 20 fatty acids (23% SDA). Interest in obtaining purified fractions of SDA arises from reported health benefits associated with polyunsaturated fatty acids (PUFA), such as cardiovascular disease prevention. In addition, SDA may also provide improved stability characteristics since its unsaturation index is less than longer PUFA, such as eicosapentaenoic acid (EPA, 20:5 ω-3). First, a chemical ethanolysis of modified soybean oil was performed to transform the triacylglycerols into fatty acid ethyl esters (FAEE). Then, the FAEE were fractionated and SDA-EE was purified by argentation silica gel (10% AgNO₃) open column chromatography, which allows selectivity based on degree of unsaturation. Different FAEE sample loads and mobile phases were explored until the best purification of SDA-EE was achieved. The solvents used were hexane and hexane:acetone mixtures (99 and 95%). Under the optimal conditions, a fraction with high SDA-EE purity (96%) was obtained with 77% yield. Besides, it was possible to obtain another fraction enriched in α-linolenic acid-EE (37% purity and 68% yield) and γ-linolenic acid-EE (22% purity and 61% yield). A scaled-up process resulted in 840 mg of final product composed of 97% SDA-EE with 71% yield.     

An interactive expert system for daylighting design exploration

Architects increasingly use digital tools during the design process, particularly as they approach such complex problems as designing for successful daylighting performance. However, while simulation tools may provide the designer with valuable information, they do not necessarily guide the user toward design changes which will improve performance. This paper proposes an interactive, goal-based expert system for daylighting design, intended for use during the early design phases. The expert system consists of two major components: a daylighting knowledge-base which contains information regarding the effects of a variety of design conditions on resultant daylighting performance, and a fuzzy rule-based decision-making logic which is used to determine those design changes most likely to improve performance for a given design. The system gives the user the ability to input an initial model and a set of daylighting performance goals in the form of illuminance and daylighting-specific glare metrics. The system acts as a “virtual daylighting consultant,” guiding the user toward improved performance while maintaining the integrity of the original design and of the design process itself. Two sets of case studies are presented: first, a comparison of the expert system results to high performing benchmark designs generated with a genetic algorithm; and second, an evaluation of the expert system performance based on varying levels of esthetic constraints. The results of these case studies indicate that the expert system is successful at finding designs with improved performance for a variety of initial geometries and daylighting performance goals.     

The selective treatment of clinical mastitis based on on-farm culture results: I. Effects on antibiotic use, milk withholding time, and short-term clinical and bacteriological outcomes

The objective of this multi-state, multi-herd clinical trial was to evaluate the efficacy of using an on-farm culture system to guide strategic treatment decisions in cows with clinical mastitis. The study was conducted in 8 commercial dairy farms ranging in size from 144 to 1,795 cows from Minnesota, Wisconsin, and Ontario, Canada. A total of 422 cows affected with mild or moderate clinical mastitis in 449 quarters were randomly assigned to either (1) a positive-control treatment program or (2) an on-farm, culture-based treatment program. Quarter cases assigned to the positive-control group received immediate on-label intramammary treatment with cephapirin sodium. Quarters assigned to the culture-based treatment program were cultured on-farm and treated with cephapirin sodium after 18 to 24 h of incubation if they had gram-positive growth or a mixed infection. Quarters with gram-negative or no growth did not receive intramammary therapy. The proportion of quarter cases assigned to positive-control and culture-based treatments that received intramammary antibiotic therapy because of study assignment was 100 and 44%, respectively; the proportion of cases that received secondary antibiotic therapy was 36 and 19%, respectively; and the proportion of cases that received intramammary antibiotic therapy because of study assignment or secondary therapy was 100 and 51%, respectively. A tendency existed for a decrease in the number of days in which milk was discarded from cows assigned to the culture-based treatment program versus cows assigned to the positive-control group (5.9 vs. 5.2 d). No statistically significant differences existed between cases assigned to the positive-control and cases assigned to the culture-based treatment program in days to clinical cure (2.7 vs. 3.2 d), bacteriological cure risk within 21 d of enrollment (71 vs. 60%), new intramammary infection risk within 21 d of enrollment (50 vs. 50%), and treatment failure risk (presence of infection, secondary treatment, clinical mastitis recurrence, or removal from herd within 21 d after enrollment; 81 vs. 78%). In summary, the use of an on-farm culture system to guide the strategic treatment of clinical mastitis reduced intramammary antibiotic use by half and tended to decrease milk withholding time by 1 d, without significant differences in days to clinical cure, bacteriological cure risk, new intramammary infection risk, and treatment failure risk within 21 d after the clinical mastitis event.     

Sampling-rate calibration for rapid and nonlethal monitoring of organic contaminants in fish muscle by solid-phase microextraction

Solid-phase microextraction (SPME) is a promising technique for determining organic contaminants within biotic systems. Existing in vivo SPME-kinetic calibration (SPME-KC) approaches are unwieldy due to the necessity of predetermining a distribution coefficient for the analyte of interest in the tissue and the preloading of a calibrating compound to the fiber. In this study, a rapid and convenient SPME alternative calibration method for in vivo analysis, termed SPME-sampling rate (SPME-SR) calibration, was developed and validated under both laboratory and field conditions to eliminate such presampling requirements. Briefly, the SPME probe is inserted into tissue, in this study fish dorsal-epaxial muscle, for 20 min allowing the concentrations of target analytes in the fish muscle to be determined by the extracted amount of analyte and the predetermined sampling rates. Atrazine, carbamazepine, and fluoxetine were detected nonlethally in the low ppb levels within fish muscle, with both laboratory and field-derived results obtained by in vivo SPME-KC comparable (within a factor of 1.27) to those obtained by lethal sampling followed by tissue liquid extraction. The technique described in this study represents an important advance which broadens the application of SPME in vivo sampling technology.     

Gradual cessation of milking reduces milk leakage and motivation to be milked in dairy cows at dry-off

The effects of gradual versus abrupt cessation of milking at dry-off in dairy cows are not well understood, but gradually reducing milk production in human mothers is known to reduce discomfort and milk leakage. This study compared the effects of abrupt versus gradual cessation of milking on milk leakage and dairy cow behavior. Holstein dairy cows were housed in groups of 6 and randomly assigned to either abrupt milk cessation (i.e., dry-off on d 0) or gradual milk cessation (i.e., skipped milkings beginning on d 0; dry-off on d 5). Four replicates were performed over time, for a total of 24 cows (mean ± SD; parity = 2.3 ± 1.2; milk production the day before d 0 = 24 ± 5 kg/d). Intramammary antibiotic, internal teat sealer, and external teat sealant were administered at dry-off. Measurements were taken from d −3 to 8 relative to dry-off. Three periods were identified for behavior data: baseline (d −3 to 1), period 1 (abrupt cows dry, gradual cows milking; d 0–4), and period 2 (all cows dry; d 5–8). Lying time was recorded with data loggers. Video scan samples (5-min intervals) were used to measure feeding time and motivation to be milked (i.e., standing at the pen's exit gate). Milk leakage was monitored every 20 min during the 2-h period following the milking times of 0500 and 1500 h after complete cessation of milking (period 1 for abrupt vs. period 2 for gradual). Composite milk samples were taken before dry-off (d −1, 0, and 5) and at the start of the next lactation (colostrum, 24 h and 7–10 d postcalving) to determine somatic cell score (SCS) and conduct bacteriological examinations in clinical mastitis cases. Regardless of treatment, dry-off resulted in reduced lying time [14.1 vs. 13.2 h/d; standard error of the difference (SED) = 0.2], reduced lying bouts (10.7 vs. 8.3 bouts/d; SED = 0.2), increased lying bout duration (1.4 vs. 1.7 h/bout; SED = 0.03) and increased feeding time (5.0 vs. 5.9 h/d; SED = 0.2). Compared with baseline, the odds of standing at the gate increased for abrupt cows (period 1: odds ratio = 6.2; 95% CI: 2.7–14.4; and period 2: odds ratio = 5.2; 95% CI: 1.8–14.6). No increase in time spent standing at the gate was noted in gradual cows. Frequency of leakage was greater in abrupt versus gradual cows (75 vs. 27%). Although the gradual treatment showed an increase in SCS over the 5 d of reduced milking frequency, both treatments showed an increase in SCS at calving and both returned to pre-experiment levels within 7 to 10 d after calving. This work demonstrates that gradually reducing milking frequency in high-producing cows results in reduced time spent anticipating milking and reduced milk leakage after dry-off.     

Psychometric characteristics and clinical correlates of NEO-PI-R fearless dominance and impulsive antisociality in the Collaborative Longitudinal Personality Disorders Study.

[Correction Notice: An erratum for this article was reported online in Psychological Assessment on September 26 2011 (see record 2011-21951-001). The Appendix should have read: Fearless Dominance: 7*, 11, 16*, 37, 46, 71, 72, 102*, 127*, 132, 144, 152, 162*, 166, 192, 227, 232 Impulsive Antisociality: 14, 30, 44*, 45, 50*, 60*, 65*, 66, 95, 99, 159, 169, 189, 201, 205, 229, 240* * Indicates a reverse-scored item (based on original item content). NEO-PI-R = NEO Personality Inventory–Revised (Costa & McCrae, 1992).] This study evaluates the validity of derived measures of the psychopathic personality traits of Fearless Dominance and Impulsive Antisociality from the NEO Personality Inventory–Revised (NEO-PI-R; Costa & McCrae, 1992) using data from the Collaborative Longitudinal Personality Disorders Study (baseline N = 733). These 3 issues were examined: (a) the stability of the measures over a 10-year interval, (b) their criterion-related validity, and (c) their incremental validity relative to an alternative NEO-PI-R profile-rating approach for assessing psychopathy. NEO-PI-R Fearless Dominance and Impulsive Antisociality scales were relatively stable across 10 years and demonstrated differential associations with measures of personality pathology and psychopathology generally consistent with past research and theoretical considerations. Moreover, these measures demonstrated an appreciable degree of incremental validity over the NEO-PI-R profile-rating approach. (PsycINFO Database Record (c) 2011 APA, all rights reserved)