Leaching of isothiocyanates through intact soil following simulated biofumigation

Biofumigation can be used as an alternative to conventional soil fumigation to control soil-borne pests. With biofumigation, plant tissue with a natural content of glucosinolates (cruciferous plants) is damaged and incorporated into the topsoil. When the plant tissue is damaged, the glucosinolates come into contact with the endogenous enzyme myrosinase, which catalyse the hydrolysis of glucosinolates into various products depending on the reaction conditions. Isothiocyanates are among the potential products formed from these reactions. We investigated if the isothiocyanates from rape plant material were leached through the soil to drain depth when a heavy rainstorm followed the biofumigation. We applied isothiocyanates from rape plant material (1,480 μmol m⁻²) to four large (0.6 m diameter, 1.0 m long) intact soil monoliths from a loamy and a sandy soil and conducted a leaching experiment under semi-field conditions. The soil monoliths were irrigated with 70–90 mm (10 mm h⁻¹) and the concentrations of three isothiocyanates (3-butenyl, 4-pentenyl and 2-phenethyl) were monitored in the leachate. Between 0 and 14.8 mmol isothiocyanates were leached for each mol of isothiocyanates applied during application of 70–90 mm irrigation. The distribution coefficient estimated from leached concentrations was 0.04–1.19 for 3-butenyl, 0.04–1.15 for 4-pentenyl isothiocyanate and 0.037–0.97 for 2-phenethyl isothiocyanate. The concentration of total isothiocyanates in the leachate was in the same order of magnitude as the LD₅₀ of isothiocyanates for sensitive aquatic organisms.     

Secular trend of dental development in Dutch children

Many studies have established dental age standards for different populations; however, very few studies have investigated whether dental development is stable over time on a population level. Therefore, the aim of this study was to analyze changes in dental maturity in Dutch children born between 1961 and 2004. We used 2,655 dental panoramic radiographs of 2‐ to 16‐year‐old Dutch children from studies performed in three major cities in the Netherlands. Based on a trend in children born between 1961 and 1994, we predicted that a child of a certain age and gender born in 1963 achieved the same dental maturity on average, 1.5 years later than a child of the same age born 40 years later. After adjusting for the birth year of a child in the analysis, the regression coefficient of the city variable was reduced by 56.6% and it remained statistically significant. The observed trend from 1961 to 1994 was extrapolated to 9‐ to 10‐year‐old children born in 2002–2004, and validation with the other samples of children with the same characteristics showed that 95.9%–96.8% of the children had dental maturity within the 95% of the predicted range. Dental maturity score was significantly and positively associated with the year of birth, gender, and age in Dutch children, indicating a trend in earlier dental development during the observation period, 1961–2004. These findings highlight the necessity of taking the year of birth into account when assessing dental development within a population with a wider time span. Am J Phys Anthropol 155:91–98, 2014. © 2014 Wiley Periodicals, Inc.     

Ecology, Inhibitory Activity, and Morphogenesis of a Marine Antagonistic Bacterium Belonging to the Roseobacter Clade

Roseobacter strain 27-4 has been isolated from a turbot larval rearing unit and is capable of reducing mortality in turbot egg yolk sac larvae. Here, we demonstrate that the supernatant of Roseobacter 27-4 is lethal to the larval pathogens Vibrio anguillarum and Vibrio splendidus in a buffer system and inhibited their growth in marine broth. Liquid chromatography (LC) with both UV spectral detection and high-resolution mass spectrometry (HR-MS) identified the known antibacterial compound thiotropocin or its closely related precursor tropodithietic acid in the bioactive fractions. Antibacterial activity correlated with the appearance of a brownish pigment and was only formed in marine broth under static growth conditions. A thick biofilm of multicellular star-shaped aggregated cells formed at the air-liquid interface under static growth conditions. Here, the bioactive compound was the base peak in the LC-UV chromatograms of the extracts where it constituted 15% of the total peak area. Aerated conditions results in 10-fold-higher cell yield, however, cultures were nonpigmented, did not produce antibacterial activity, and grew as single cells. Production of antibacterial compounds may be quorum regulated, and we identified the acylated homoserine lactone (3-hydroxy-decanoyl homoserine lactone) from cultures of Roseobacter 27-4 using LC-HR-MS. The signal molecule was primarily detected in stagnant cultures. Roseobacter 27-4 grew between 10 and 30°C but died rapidly at 37°C. Also, the antibacterial compounds was sensitive to heat and was inactivated at 37°C in less than 2 days and at 25°C in 8 days. Using Roseobacter 27-4 as a probiotic culture will require that is be established in stagnant or adhered conditions and, due to the temperature sensitivity of the active compound, constant production must be ensured.     

Competition between ammonia-oxidizing bacteria and benthic microalgae

The abundance, activity, and diversity of ammonia-oxidizing bacteria (AOB) were studied in prepared microcosms with and without microphytobenthic activity. In the microcosm without alga activity, both AOB abundance, estimated by real-time PCR, and potential nitrification increased during the course of the experiment. AOB present in the oxic zone of these sediments were able to fully exploit their nitrification potential because NH(4)(+) did not limit growth. In contrast, AOB in the alga-colonized sediments reached less than 20% of their potential activity, suggesting starvation of cells. Starvation resulted in a decrease with time in the abundance of AOB as well as in nitrification potential. This decrease was correlated with an increase in alga biomass, suggesting competitive exclusion of AOB by microalgae. Induction of N limitation in the oxic zone of the alga-colonized sediments and O(2) limitation of the majority of AOB in darkness were major mechanisms by which microalgae suppressed the growth and survival of AOB. The competition pressure from the algae seemed to act on the entire population of AOB, as no differences were observed by denaturing gradient gel electrophoresis of amoA fragments during the course of the experiment. Enumeration of bacteria based on 16S rRNA gene copies and d-amino acids suggested that the algae also affected other bacterial groups negatively. Our data indicate that direct competitive interaction takes place between algae and AOB and that benthic algae are superior competitors because they have higher N uptake rates and grow faster than AOB.     

Traditional Knowledge,Use, and Management of <Emphasis Type="Italic">Aphandra natalia</Emphasis> (Arecaceae) in Amazonian Peru

Traditional Knowledge, Use, and Management of Aphandra natalia (Arecaceae) in Amazonian Peru. Along the Pastaza and Urituyacu rivers in Peru, 100 informants in four villages knew 17 different uses of the piassaba fiber palm, Aphandra natalia (Balslev and Henderson) Barfod. Human consumption of fruits, extraction of fibers for trade, and harvesting leaves for thatch were the most frequently reported uses. Twenty uses were documented previously in the literature, and eight are reported here for the first time. Knowledge concerning the use of A. natalia among villagers varied significantly with ethnicity, village, and gender, but not with education or age; Amerindian informants knew more than non-Amerindian informants, and men knew more than women. Old and young informants knew about the same numbers of uses, and those who had little formal school training knew as many as those who had attended school for a longer time. Although 44% of our informants knew about fiber extraction, trade involving Aphandra fibers was not of great economic importance in our study area. Because fiber extraction has been documented as the most important use in all previous studies of A. natalia, it was surprising to find that people in one of the studied villages did not use A. natalia for that purpose at all. In contrast to previous observations, the extraction of fibers involved the destructive felling of the palms. We recommend implementing non-destructive extraction techniques so that local communities could exploit the fiber resource in a sustainable way. Non-destructive extraction methods involve cutting leaves from standing palms instead of felling the entire tree and leaving a few leaves on each extracted palm. However, given the limited economic incentive to the extractor, market mechanisms may be the greatest barrier to implementing sustainable extraction techniques.     

A tomato ER-type Ca-ATPase, LCA1, has a low thapsigargin-sensitivity and can transport manganese

Recombinant Ca²⁺-ATPase from tomato (i.e. LCA1 for Lycopersicon esculentum [Since the identification and naming of LCA1, the scientific name for the tomato has been changed to Solanum lycopersicum.] Ca-ATPase) was heterologously expressed in yeast for structure-function characterization. We investigate the differences between plant and animal Ca pumps utilizing comparisons between chicken and rabbit SERCA-type pumps with Arabidopsis (ECA1) and tomato plant (LCA1) Ca²⁺-ATPases. Enzyme function was confirmed by the ability of each Ca²⁺-ATPase to rescue K616 growth on EGTA-containing agar and directly via in vitro ATP hydrolysis. We found LCA1 to be ∼300-fold less sensitive to thapsigargin than animal SERCAs, whereas ECA1 was thapsigargin-resistant. LCA1 showed typical pharmacological sensitivities to cyclopiazonic acid, vanadate, and eosin, consistent with it being a P_IIA-type Ca²⁺-ATPase. Possible amino acid changes responsible for the reduced plant thapsigargin-sensitivity are discussed. We found that LCA1 also complemented K616 yeast growth in the presence of Mn²⁺, consistent with moving Mn²⁺ into the secretory pathway and functionally compensating for the lack of secretory pathway Ca-ATPases (SPCAs) in plants.     

Preparation of an unprotected phosphotyrosine building block and its application in solid-phase synthesis of phosphopeptides

Summary A new and facile synthesis of tyrosine phosphorylated peptides has been developed.N ^α-Fmoc-Tyr(tBu)-OPfp was treated with TFA, phosphorylated with phosphorous oxychloride and the resulting phosphoric acid dichloride was hydrolysed to giveN ^α-Fmoc-Tyr(PO₃H₂)-OPfp1 in an overall yield of 98%. Compound1 was used in solid-phase peptide synthesis of phosphopeptides2, 3 and4, which are fragments of murine adipocyte lipid binding protein. The advantage of using the Pfp ester was the absence of pyrophosphates and other byproducts.     

Placental superoxide dismutase 3 mediates benefits of maternal exercise on offspring health

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Large-scale validation of methods for cytotoxic T-lymphocyte epitope prediction

Background  

Reliable predictions of Cytotoxic T lymphocyte (CTL) epitopes are essential for rational vaccine design. Most importantly, they can minimize the experimental effort needed to identify epitopes. NetCTL is a web-based tool designed for predicting human CTL epitopes in any given protein. It does so by integrating predictions of proteasomal cleavage, TAP transport efficiency, and MHC class I affinity. At least four other methods have been developed recently that likewise attempt to predict CTL epitopes: EpiJen, MAPPP, MHC-pathway, and WAPP. In order to compare the performance of prediction methods, objective benchmarks and standardized performance measures are needed. Here, we develop such large-scale benchmark and corresponding performance measures and report the performance of an updated version 1.2 of NetCTL in comparison with the four other methods.     

Maternal weight change from prepregnancy to 18 months postpartum and subsequent risk of hypertension and cardiovascular disease in Danish women: A cohort study

BackgroundOne-fourth of women experience substantially higher weight years after childbirth. We examined weight change from prepregnancy to 18 months postpartum according to subsequent maternal risk of hypertension and cardiovascular disease (CVD).Methods and findingsWe conducted a cohort study of 47,966 women with a live-born singleton within the Danish National Birth Cohort (DNBC; 1997–2002). Interviews during pregnancy and 6 and 18 months postpartum provided information on height, gestational weight gain (GWG), postpartum weights, and maternal characteristics. Information on pregnancy complications, incident hypertension, and CVD was obtained from the National Patient Register. Using Cox regression, we estimated adjusted hazard ratios (HRs; 95% confidence interval [CI]) for hypertension and CVD through 16 years of follow-up. During this period, 2,011 women were diagnosed at the hospital with hypertension and 1,321 with CVD. The women were on average 32.3 years old (range 18.0–49.2) at start of follow-up, 73% had a prepregnancy BMI <25, and 27% a prepregnancy BMI ≥25. Compared with a stable weight (±1 BMI unit), weight gains from prepregnancy to 18 months postpartum of >1–2 and >2 BMI units were associated with 25% (10%–42%), P = 0.001 and 31% (14%–52%), P < 0.001 higher risks of hypertension, respectively. These risks were similar whether weight gain presented postpartum weight retention or a new gain from 6 months to 18 months postpartum and whether GWG was below, within, or above the recommendations. For CVD, findings differed according to prepregnancy BMI. In women with normal-/underweight, weight gain >2 BMI units and weight loss >1 BMI unit were associated with 48% (17%–87%), P = 0.001 and 28% (6%–55%), P = 0.01 higher risks of CVD, respectively. Further, weight loss >1 BMI unit combined with a GWG below recommended was associated with a 70% (24%–135%), P = 0.001 higher risk of CVD. No such increased risks were observed among women with overweight/obesity (interaction by prepregnancy BMI, P = 0.01, 0.03, and 0.03, respectively). The limitations of this observational study include potential confounding by prepregnancy metabolic health and self-reported maternal weights, which may lead to some misclassification.ConclusionsPostpartum weight retention/new gain in all mothers and postpartum weight loss in mothers with normal-/underweight may be associated with later adverse cardiovascular health.

Helene Kirkegaard and co-workers study maternal weight changes and cardiovascular risk over 16 years of follow-up.