Characterization of plant-derived water extractable organic matter by multiple spectroscopic techniques

Water extractable organic matter (WEOM) derived from fresh- or early-stage decomposing soil amendment materials may play an important role in the process of organic matter accumulation. In this study, eight WEOM samples extracted with a 40:1 (v/w) water to sample ratio from alfalfa (Medicago sativa L.), corn (Zea mays L.), crimson clover (Trifolium incarnatum L.), hairy vetch (Vicia villosa L.), lupin (Lupinus albus L.), soybean (Glycine max L. Merr.), wheat (Triticum aestivum L.), and dairy manure were investigated using ultraviolet (UV)–visible, Fourier transform infrared (FT-IR), solution ³¹P nuclear magnetic resonance (NMR), and solid state ¹³C NMR spectroscopies. UV–visible and FT-IR spectra of the plant-derived WEOM samples were typical for natural organic matter, but possessed less humic-like characteristics than dairy manure-derived WEOM. Solution ³¹P NMR spectra indicated that WEOM samples extracted from alfalfa, corn, and soybean shoots contained both orthophosphate and monoester P. Of the monoester P in WEOM from soybean shoot, 70% was phytate P. WEOM from crimson clover, hairy vetch, lupin, and wheat shoots contained orthophosphate only. The solid-state ¹³C NMR spectra of the seven plant-derived WEOM samples indicated that they all were primarily composed of sugars, amino acids or peptides, and low molecular mass carboxylic acids. Carbohydrates were dominant components with very few aromatics present in these samples. In addition, WEOM from crimson clover and lupin, but not other three leguminous plant WEOM samples, contained significant asparagine. On the other hand, WEOM from corn and wheat contained less amino acids or peptides. The spectra of WEOM of dairy manure revealed the presence of significant amounts of nonprotonated carbons and lignin residues, suggesting humification of the manure-derived WEOM. Significant carbohydrates as well as aromatics were present in this WEOM. The P and C bonding information for these WEOM samples may be useful for understanding the effects of WEOM on soil nutrient availability to plants. Trade or manufacturers' names mentioned in the paper are for information only and do not constitute endorsement, recommendation, or exclusion by the USDA-ARS.     

Factors Affecting Plasma Pregnancy-associated Glycoprotein 1 Concentrations Throughout Gestation in High-producing Dairy Cows

This study was designed to establish the factors, if any, which could affect plasma pregnancy-associated glycoprotein-1 (PAG-1) expression in a study population of 87 pregnant, high-producing dairy cows. The factors examined were: semen providing breed (Holstein-Friesian vs Limousin), outcome of gestation (male vs female newborn, and singleton vs twin pregnancies), lactation number, milk production at pregnancy diagnosis, plasma progesterone concentration, season of gestation (warm period, March–November vs cool period, December–February), and day of gestation (40, 90, 120, 150, 180 and 210). Pregnancy was diagnosed by transrectal ultrasound on day 40 post-insemination and by palpation per rectum on days 90, 120, 150, 180 and 210. Blood samples were collected from each animal immediately before each pregnancy diagnosis. The relative contributions of the different factors on PAG-1 concentrations were evaluated by GLM repeated measures analysis of variance. No significant effects of the herd, foetal sex, milk production, lactation number and plasma progesterone concentrations were observed. In contrast, twin pregnancy, the use of Limousin semen and conception during the cool period were correlated with significantly increased plasma PAG-1 concentrations throughout gestation. Our data indicate that both cow well-being during early placental development, determined in our conditions by reduced heat stress when conception occurred in the cool season, and crossbreed pregnancies lead to improved PAG-1 production throughout the gestation period.     

Demographics of cattle positive for Mycobacterium avium subspecies paratuberculosis by faecal culture,from submissions to the Cork Regional Veterinary Laboratory

The demography of bovine infections caused by Mycobacterium avium subspecies paratuberculosis (MAP) in Ireland is poorly defined. The objective of this study was to describe the demographics of cattle positive to MAP on faecal culture, based on submissions to the Cork Regional Veterinary Laboratory (Cork RVL) from 1994 to 2006. The study focused on all available faecal samples from adult cattle with non-responsive chronic diarrhoea that were submitted by private veterinary practitioners to Cork RVL for MAP culture. For each MAP-positive by faecal culture animal, data were collated from Cork RVL and Cattle Movement Monitoring Scheme (CMMS) records. Johne's disease (JD) was confirmed in 110 animals from 86 herds by the Cork RVL between 1994 and 2006, with a rate of positive cases between 15% and 18% over last four years of the study. Two breeds (Holstein/Friesian or Limousin) made up 78% of submissions. Movements were assessed for the 57 study animals with available movement information, 90% died within one year of the test and 26% tested positive in the herd they were born into. The study provides preliminary information about movement trends and demographics of animals with MAP positive submissions. Although the study area is restricted, it includes the most intensive (and economically-important) dairy region in Ireland. The demographics of JD infection from the study area are in agreement with international reports. Further work is required to determine demographic trends, incidence and prevalence of JD throughout Ireland. It is hoped this work may contribute to the development of a surveillance strategy for MAP by regional veterinary laboratories.     

Illustrating the critical role of human dimensions research for understanding and managing recreational fisheries within a social‐ecological system framework

Effective management of recreational fishing requires understanding fishers and their actions. These actions constitute critical links between social and ecological systems that result in outcomes that feedback and influence recreational fishers' actions and the management of these actions. Although much research exists on recreational fishers and their actions, this research is often disconnected from management issues. One way to help to overcome this disconnect is to illustrate how past research on the social component of recreational fishing fits within an emerging coupled social‐ecological system (SES) framework. Herein, a conceptual SES is first developed with specific attention to recreational fisheries. This SES is then used to illustrate the importance of considering human dimensions research for articulating, studying and ultimately managing key outcomes of recreational fisheries (e.g. fish population conservation, fisher well‐being) using the example of harvest regulations and a brief review of past interdisciplinary research on recreational fishing. The article ends by identifying key research needs including understanding: how factors such as management rules affect the diversity of actions by recreational fishers; how governance and management approaches adapt to changing social and resource conditions; and how recreational fishers learn and share information.     

Microbial regulation in gorgonian corals

Gorgonian corals possess many novel natural products that could potentially mediate coral-bacterial interactions. Since many bacteria use quorum sensing (QS) signals to facilitate colonization of host organisms, regulation of prokaryotic cell-to-cell communication may represent an important bacterial control mechanism. In the present study, we examined extracts of twelve species of Caribbean gorgonian corals, for mechanisms that regulate microbial colonization, such as antibacterial activity and QS regulatory activity. Ethanol extracts of gorgonians collected from Puerto Rico and the Florida Keys showed a range of both antibacterial and QS activities using a specific Pseudomonas aeruginosa QS reporter, sensitive to long chain AHLs and a short chain N-acylhomoserine lactones (AHL) biosensor, Chromobacterium violaceium. Overall, the gorgonian corals had higher antimicrobial activity against non-marine strains when compared to marine strains. Pseudopterogorgia americana, Pseusopterogorgia acerosa, and Pseudoplexuara flexuosa had the highest QS inhibitory effect. Interestingly, Pseudoplexuara porosa extracts stimulated QS activity with a striking 17-fold increase in signal. The stimulation of QS by P. porosa or other elements of the holobiont may encourage colonization or recruitment of specific microbial species. Overall, these results suggest the presence of novel stimulatory QS, inhibitory QS and bactericidal compounds in gorgonian corals. A better understanding of these compounds may reveal insight into coral-microbial ecology and whether a therapeutic potential exists.     

COMPARISON OF THORACIC ULTRASONOGRAPHY AND RADIOGRAPHY FOR THE DETECTION OF INDUCED SMALL VOLUME PNEUMOTHORAX IN THE HORSE

Small volume pneumothorax can be challenging to diagnose in horses. The current standard method for diagnosis is standing thoracic radiography. We hypothesized that thoracic ultrasonography would be more sensitive. Objectives of this prospective, experimental study were to describe a thoracic ultrasound method for detection of small volume pneumothorax in horses and to compare results of radiography and ultrasound in a sample of horses with induced small volume pneumothorax. Six mature healthy horses were recruited for this study. For each horse, five 50 ml air boluses were sequentially introduced via a teat cannula into the pleural space. Lateral thoracic radiographs and standardized ultrasound (2D and M‐mode) examinations of both hemithoraces were performed following administration of each 50 ml air bolus. Radiographs and ultrasound images/videos were analyzed for detection of pneumothorax by four independent investigators who were unaware of treatment status. Sensitivity, specificity, positive predictive values, negative predictive values, and agreement among investigators (Kappa test, κ) were calculated for radiography, 2D and M‐mode ultrasound. Comparisons were made using a chi‐squared exact test with significance set at P < 0.05. Two‐dimensional (84%) and M‐mode (80%) ultrasound were more sensitive than radiography (48%) for pneumothorax detection (P = 0.02 and P = 0.04, respectively). Specificity and positive predictive values were similar for all three imaging modalities (P = 1). Agreement between investigators for pneumothorax detection was excellent for 2D ultrasound (κ = 1), very good for M‐mode ultrasound (κ = 0.87), and good for radiography (κ = 0.79). Findings from this experimental study supported the use of thoracic ultrasonography as a diagnostic method for detecting pneumothorax in horses.     

European Eel Sperm Diluent for Short‐term Storage

The sperm of European eel shows a high density and the time of spermatozoa motility is very short after activation with sea water. These characteristics make difficult the sperm handling and its quality assessment. Several diluents were previously described for the Japanese eel obtaining over 3 weeks’ conservation times under refrigeration, but they rendered bad results in the European species. In the present study, several diluents were developed taking as basis the P1 medium, and using different dilution ratios (1 : 50, 1 : 100) and two pH (6.5, 8.5). The effect of the addition of bovine serum albumin (BSA, 2% w/v) was also evaluated. At 24 h, undiluted samples already showed significant lower motility and viability than sperm samples diluted in the different media. The results for diluents with pH 6.5 and 8.5 were different. Spermatozoa diluted in media at pH 6.5 cannot be activated at 24 h, while samples diluted in the diluents with pH 8.5 and added with BSA did not show significant differences with respect to the fresh sperm motility until 48 h. The viability (percentage of alive cells) did not show differences until 1 week, independent of the dilution ratio. After 1 week, the motility was approximately 30% in the media containing BSA, which presented no differences for head size of the spermatozoa (perimeter and area) until 72 h and 1 week, respectively. In conclusion, the combination of one medium having similar physico‐chemical characteristics to the seminal plasma, including pH 8.5, and supplemented with BSA can be used in different dilution ratios for the sperm’s short‐term storage, preserving its motility capacity.     

Pregnancy‐Associated Glycoprotein and Progesterone Concentrations during Pregnancy Failure in Bedouin Goat from the Southwest of Algeria

Thirteen female Bedouin goats living in arid land of Algeria Sahara desert were used in this study. These goats were pregnant but they sustained an abortion because of unidentified causes. None of the goats showed any signs of general disease. Plasma concentrations of caprine pregnancy‐associated glycoproteins (cPAGs) and progesterone (P4) were determined during pregnancy using radioimmunoassay. The cPAGs concentration was undetectable (<0.8 ng/ml) throughout the first 2 weeks of gestation. From week 3 after mating, cPAGs concentration was detectable with significant individual variations (p < 0.05) reaching a maximum secretion (436.1 ng/ml). Throughout gestation, cPAGs concentration remained relatively constant but decreased few days before abortion, on an average of 9.2 ± 1.2 days (n = 11), except for two females where the concentrations decreased later (1–2 days before abortion). One or two peaks of cPAGs concentrations (in 4/13 and in 9/13 females, respectively) have been measured few weeks before abortion (77–124 days after mating), when a decline of cPAGs was detected. The P4 concentration increased after mating, and was high from the first week till the end of pregnancy. The P4 concentration (9.1 ± 0.9 ng/ml) decreased rapidly (<0.5 ng/ml) after 4 ± 0.7 days (n = 6) or 9.4 ± 1.6 days (n = 7) before abortion. A positive relationship (p < 0.01) was found between P4 and cPAGs concentrations during gestation. Results indicate that cPAGs and P4 measurements can be used for monitoring gestation and for abortion prediction.