The Detection of Inhibitors of the Sclerotinia sclerotiorum (Lib.) de Bary Extracellular Proteinases in Sunflower

Abstract: Water-soluble protein fractions from leaves, seeds and heads of sunflower were shown to contain inhibitors of trypsin, chymotrypsin and extracellular proteinases from Sclerotinia sclerotiorum , a pathogen of sunflower, and Colletotrichum lindemuthianum. These included bifunctional inhibitors of trypsin and subtilisin. Comparison with the patterns of inhibition of standard proteinases indicated that the major extracellular proteinases of S. sclerotiorum are subtilisin-like. It is speculated that the sunflower inhibitors play a role in conferring resistance to fungal infection.     

The effect of nutrient availability and temperature on chain length of the diatom, Skeletonema costatum

We determined the effects of temperature and nutrients on thechain length of a diatom, Skeletonema costatum, in batch cultureand enclosure experiments with estuarine water from San FranciscoBay, USA, using the recently developed CytoBuoy flow cytometer.Determination of the number of cells per diatom chain by CytoBuoyflow cytometer and associated software correlated well withbut was much more precise and time efficient than microscopicquantification. Increasing temperatures (from 6, 8 to 17°C)and nutrient concentrations induced high growth rates and dominanceby longer chains in a cultured S. costatum strain that was originallyacclimatized to a temperature range of 11–30°C. Similarly,a positive correlation between growth rate and chain lengthwas observed in S. costatum in batch culture and natural communitiesin enclosure experiments. Maximal chain lengths of S. costatumwere greater in natural populations than in the batch culture.Longer chains affect sinking rates and thus likely help thediatom remain suspended in the upper part of the water columnwhere physical and chemical parameters are more favorable forgrowth.     

Understanding the function of nocturnal song in ovenbirds: males do not countersing at night

Many diurnal bird species vocalize at night, however the function of nocturnal song is, generally, still poorly understood. Previous research has suggested that nocturnal song may serve a social function and is influenced by environmental factors. To test whether males attend to the nocturnal song of conspecifics, we experimentally exposed ovenbirds Seiurus aurocapilla to nocturnal flight songs, and recorded their response both during the night and during the following dawn chorus. We compared latency to song and vocal output before and after playback exposure to determine if males altered their vocalizations in response to exposure to flight songs from an unknown male. We found no evidence of counter singing or change in nocturnal song output, nor a change in vocal output during the dawn chorus following playback exposure. Our results suggest that, in ovenbirds, nocturnal song does not serve as an intraspecific social function. Nocturnal song, through rare, may be significant in the mating systems of some diurnal bird species, and requires additional study.     

Blebs produced by actin–myosin contraction during apoptosis release damage-associated molecular pattern proteins before secondary necrosis occurs

Apoptosis is a fundamental homeostatic mechanism essential for the normal growth, development and maintenance of every tissue and organ. Dying cells have been defined as apoptotic by distinguishing features, including cell contraction, nuclear fragmentation, blebbing, apoptotic body formation and maintenance of intact cellular membranes to prevent massive protein release and consequent inflammation. We now show that during early apoptosis limited membrane permeabilization occurs in blebs and apoptotic bodies, which allows release of proteins that may affect the proximal microenvironment before the catastrophic loss of membrane integrity during secondary necrosis. Blebbing, apoptotic body formation and protein release during early apoptosis are dependent on ROCK and myosin ATPase activity to drive actomyosin contraction. We identified 231 proteins released from actomyosin contraction-dependent blebs and apoptotic bodies by adapted SILAC (stable isotope labeling with amino acids in cell culture) combined with mass spectrometry analysis. The most enriched proteins released were the nucleosomal histones, which have previously been identified as damage-associated molecular pattern proteins (DAMPs) that can initiate sterile inflammatory responses. These results indicate that limited membrane permeabilization occurs in blebs and apoptotic bodies before secondary necrosis, leading to acute and localized release of immunomodulatory proteins during the early phase of active apoptotic membrane blebbing. Therefore, the shift from apoptosis to secondary necrosis is more graded than a simple binary switch, with the membrane permeabilization of apoptotic bodies and consequent limited release of DAMPs contributing to the transition between these states.     

HPLC‐Fluorescence Method for the Enantioselective Analysis of Propranolol in Rat Serum Using Immobilized Polysaccharide‐Based Chiral Stationary Phase

A stereoselective high‐performance liquid chromatographic (HPLC) method was developed and validated to determine S‐(?)‐ and R‐(+)‐propranolol in rat serum. Enantiomeric resolution was achieved on cellulose tris(3,5‐dimethylphenylcarbamate) immobilized onto spherical porous silica chiral stationary phase (CSP) known as Chiralpak IB. A simple analytical method was validated using a mobile phase consisted of n‐hexane‐ethanol‐triethylamine (95:5:0.4%, v/v/v) at a flow rate of 0.6 mL min^‐1 and fluorescence detection set at excitation/emission wavelengths 290/375 nm. The calibration curves were linear over the range of 10–400 ng mL^‐1 (R = 0.999) for each enantiomer with a detection limit of 3 ng mL^‐1. The proposed method was validated in compliance with ICH guidelines in terms of linearity, accuracy, precision, limits of detection and quantitation, and other aspects of analytical validation. Actual quantification could be made for propranolol isomers in serum obtained from rats that had been intraperitoneally (i.p.) administered a single dose of the drug. The proposed method established in this study is simple and sensitive enough to be adopted in the fields of clinical and forensic toxicology. Molecular modeling studies including energy minimization and docking studies were first performed to illustrate the mechanism by which the active enantiomer binds to the β‐adrenergic receptor and second to find a suitable interpretation of how both enantiomers are interacting with cellulose tris(3,5‐dimethylphenylcarbamate) CSP during the process of resolution. The latter interaction was demonstrated by calculating the binding affinities and interaction distances between propranolol enantiomers and chiral selector. Chirality 26:194–199, 2014. © 2014 Wiley Periodicals, Inc.     

Genome-wide association study of handedness excludes simple genetic models

Handedness is a human behavioural phenotype that appears to be congenital, and is often assumed to be inherited, but for which the developmental origin and underlying causation(s) have been elusive. Models of the genetic basis of variation in handedness have been proposed that fit different features of the observed resemblance between relatives, but none has been decisively tested or a corresponding causative locus identified. In this study, we applied data from well-characterised individuals studied at the London Twin Research Unit. Analysis of genome-wide SNP data from 3940 twins failed to identify any locus associated with handedness at a genome-wide level of significance. The most straightforward interpretation of our analyses is that they exclude the simplest formulations of the ‘right-shift'' model of Annett and the ‘dextral/chance'' model of McManus, although more complex modifications of those models are still compatible with our observations. For polygenic effects, our study is inadequately powered to reliably detect alleles with effect sizes corresponding to an odds ratio of 1.2, but should have good power to detect effects at an odds ratio of 2 or more.     

Determination of myoseverin embryotoxic potential by using FETAX

BACKGROUND: Since MYS is a microtubular poison with a reversible activity, Xenopus blastulae were exposed to MYS to verify the eventual drug-related developmental suspension and the reversibility of this effect. METHODS: Lethal and teratogenic effects of myoseverin (MYS) were evaluated using the FETAX. Embryos were exposed to different MYS concentrations from stage 8 to stage 47. RESULTS: Probit analysis gave 12.14 microM LC50 and 7.67 microM TC50 from which 1.58 T.I. is derived. Several malformations were observed such as facial abnormalities, abnormal tail flexure, heart ventricle chamber enlargement and external appendix. MYS led to an arrest of living embryo development. Before MYS removing, exposed blastulae showed the lack of mitotic spindles along with different nuclei alterations. Living embryos, moved in control solution, mainly died around the hatching showing severe malformations likely ascribable to the altered planes of newly occurring mitosis. CONCLUSION: In spite of the low T.I, MYS has to be considered a highly teratogenic compound.     

Impact of white‐tailed deer on the spread of Borrelia burgdorferi

There is a public perception that the white‐tailed deer Odocoileus virginianus (Artiodactyla: Cervidae) is the main reservoir supporting the maintenance and spread of the causative agent of Lyme disease, Borrelia burgdorferi. This study examines the pathogen prevalence rate of Borrelia in adult Ixodes scapularis (Ixodida: Ixodidae), the black‐legged tick, collected from white‐tailed deer and compares it with pathogen prevalence rates in adult ticks gathered by dragging vegetation in two contiguous counties west of the Hudson Valley in upstate New York. In both Broome and Chenango Counties, attached and unattached ticks harvested from white‐tailed deer had significantly lower prevalences of B. burgdorferi than those collected from vegetation. No attached ticks on deer (n = 148) in either county, and only 2.4 and 7.3% of unattached ticks (n = 389) in Broome and Chenango Counties, respectively, were harbouring the pathogen. This contrasts with the finding that 40.8% of ticks in Broome County and 46.8% of ticks in Chenango County collected from vegetation harboured the pathogen. These data suggest that a mechanism in white‐tailed deer may aid in clearing the pathogen from attached deer ticks, although white‐tailed deer do contribute to the spatial distribution of deer tick populations and also serve as deadend host breeding sites for ticks.     

Aspects of the bionomics of Phlebotomus sergenti sandflies from an endemic area of anthroponotic cutaneous leishmaniasis in Aleppo Governorate, Syria

Aspects of the bionomics of phlebotomine sandflies (Diptera: Psychodidae) were studied from June to November 2005 in three foci of anthroponotic cutaneous leishmaniasis (ACL) in Aleppo Governorate, Syria, where the agent Leishmania tropica (Wright) (Kinetoplastida: Trypanosomatidae) is transmitted by Phlebotomus sergenti Parrot. Syria has been designated by the World Health Organization as one of four countries in the Old World where cutaneous leishmaniasis is hyperendemic, but little is known about the biology of local vector populations. Standard collections by sticky traps showed two peaks in density, in June and late August. In total, 1840 sandflies were caught, comprising five species: Phlebotomus papatasi (Scopoli) (68.0%); P. sergenti (25.4%); Sergentomyia minuta (Rondani) (6.4%); Phlebotomus tobbi Adler & Theodor (0.1%), and Phlebotomus mascittii canaaniticus Adler & Theodor (0.1%). Similar numbers of P. sergenti were caught indoors (246 specimens) and outdoors (222), whereas P. papatasi was significantly more abundant indoors (1096 specimens) than outdoors (156) (χ² = 241, P < 0.01). In total, 212 blood-fed females were tested for host blood determination, of which 176 (83.0%) reacted with anti-species reagent. Results from 20 P. sergenti suggest that this species is an opportunistic feeder, imbibing human, ovine, avian, bovine and feline blood, although more bloodmeals were taken from humans and cattle than expected in relation to the relative proportions of potential hosts present (the forage ratio, FR). The bionomics of P. sergenti are discussed in relation to the inefficacy of control campaigns based on indoor spraying with residual insecticides that have been implemented by the Syrian Ministry of Health to control the epidemics of ACL in the Aleppo Governorate.