Development of reverse transcription loop mediated isothermal amplification assay for visual detection of Grapevine fleck virus (GFkV)

Grapevine fleck virus (GFkV) produces a ubiquitous disease, latent in grapevine causing simple or complex infections with other more dangerous viruses. The aim of the present study is to detect GFkV through application of reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay; its efficiency has been contrasted with other procedures such as Double antibody sandwich ELISA (DAS-ELISA) and RT-polymerase chain reaction (PCR). The coat protein (CP) gene of the virus is basically used for designing the primers. Using hydroxynaphthol blue (HNB) Dye, RT-LAMP was placed in a water bath after the optimization was done. In order to detect GFkV easily and rapidly, a new immunocapture (IC)-RT-LAMP assay was developed as well; it was further compared with other assays. The results show RT-LAMP is an advantageous method because it is highly sensitive, quite cheap, user-friendly, and safe; in addition, it is performed quickly by visual detection and does not require RNA extraction (in IC-RT-LAMP)

Signalling value of maternal and paternal melanism in the barn owl : implication for the resolution of the lek paradox

Secondary sexual characters often signal qualities such as physiological processes associated with resistance to various sources of stress. When the expression of an ornament is not sex-limited, we can identify the costs and benefits of displaying a trait that is typical of its own sex or of the other sex. Indeed, the magnitude and sign of the covariation between physiology and the extent to which an ornament is expressed could differ between males and females if, for instance, the regulation of physiological processes is sensitive to sex hormones. Using data collected over 14 years in the nocturnal barn owl Tyto alba, we investigated how nestling body mass covaries with a heritable melanin-based sex-trait, females displaying on average larger black feather spots than males. Independently of nestling sex, year and time of the day large-spotted nestlings were heavier than small-spotted nestlings. In contrast, the magnitude and sign of the covariation between nestling body mass and the size of parental spots varied along the day in a way that depended on the year and parental gender. In poor years, offspring of smaller-spotted mothers were heavier throughout the resting period; in the morning, offspring sired by larger-spotted fathers were heavier than offspring of smaller-spotted fathers, while in the evening the opposite pattern was found. Thus, maternal and paternal coloration is differentially associated with behaviour or physiology, processes that are sensitive to time of the day and environmental factors. Interestingly, the covariation between offspring body mass and paternal coloration is more sensitive to these environmental factors than the covariation with maternal coloration. This indicates that the benefit of pairing with differently spotted males may depend on environmental conditions, which could help maintain genetic variation in the face of intense directional (sexual) selection

Barn Owl (Tyto alba) breeding biology in relation to breeding season climate

Winter weather has a strong influence on Barn Owl (Tyto alba) breeding biology. Here, we analyzed the impacts of weather conditions on reproductive performance during the breeding season using data collected over 22 years in a Swiss Barn Owl population. Variations in rain and temperature during the breeding season played an important role in within-year variation in Barn Owl reproduction. An increase in rainfall during the period from 4 to 2 weeks preceding egg laying had a positive effect on clutch size. In contrast, fledgling body mass was negatively influenced by rainfall during the 24 h preceding the measurements. Finally, ambient temperature during the rearing period was positively associated with brood size at fledging. In conclusion, weather conditions during the breeding season place constraints on Barn Owl reproduction

Enantioselective conjugate addition of ketones to β-nitrostyrenes catalyzed by 1,2-amino alcohol-derived prolinamides

Various l-prolinamides 14, prepared from l-proline and chiral β-amino alcohols, are active bifunctional catalysts for the direct nitro-Michael addition of ketones to β-nitrostyrenes. In particular, catalyst 14e prepared from l-proline and (1S,2R)-cis-1-amino-2-indanol exhibits the highest catalytic performance working in polar aprotic solvents such as NMP. High syn-diastereoselectivities (up to 94% de) and good enantioselectivities (up to 80% ee) were obtained at rt.This work has been supported by the Dirección General de Investigación of the Ministerio de Educación y Ciencia (CTQ2004-00808/BQU), by the Generalitat Valenciana (CTIOIB/2002/320, GRUPOS03/134, GRUPOS05/11 and GV05/157) and the University of Alicante

Tawny Owl Strix aluco as a bioindicator of Barn Owl Tyto alba breeding and the effect of winter severity on Barn Owl reproduction

In the temperate zone, food availability and winter weather place serious constraints on European Barn Owl Tyto alba populations. Using data collected over 22years in a Swiss population, we analysed the influence of early pre-breeding food conditions and winter severity on between-year variations in population size and reproductive performance. To estimate pre-breeding food conditions, we attempted a novel approach based on an index that combines Tawny Owl Strix aluco reproductive parameters and the occurrence of wood mice Apodemus sp. in their diet. Tawny Owls breed earlier in the season than Barn Owls and are strongly dependent on the abundance of wood mice for breeding. This index was strongly positively associated with the number of breeding pairs and early breeding in the Barn Owl. Winter severity, measured by snow cover and low temperatures, had a pronounced negative influence on the size of the breeding population and clutch size. Food conditions early in the breeding season and winter severity differentially affect the Barn Owl life cycle. We were able to use aspects of the ecology and demography of the Tawny Owl as an indicator of the quality of the environment for a related species of similar ecology, in this case the Barn Owl

Agricultural land use and human presence around breeding sites increase stress-hormone levels and decrease body mass in barn owl nestlings.

Human activities can have a suite of positive and negative effects on animals and thus can affect various life history parameters. Human presence and agricultural practice can be perceived as stressors to which animals react with the secretion of glucocorticoids. The acute short-term secretion of glucocorticoids is considered beneficial and helps an animal to redirect energy and behaviour to cope with a critical situation. However, a long-term increase of glucocorticoids can impair e.g. growth and immune functions. We investigated how nestling barn owls (Tyto alba) are affected by the surrounding landscape and by human activities around their nest sites. We studied these effects on two response levels: (a) the physiological level of the hypothalamus-pituitary-adrenal axis, represented by baseline concentrations of corticosterone and the concentration attained by a standardized stressor; (b) fitness parameters: growth of the nestlings and breeding performance. Nestlings growing up in intensively cultivated areas showed increased baseline corticosterone levels late in the season and had an increased corticosterone release after a stressful event, while their body mass was decreased. Nestlings experiencing frequent anthropogenic disturbance had elevated baseline corticosterone levels, an increased corticosterone stress response and a lower body mass. Finally, breeding performance was better in structurally more diverse landscapes. In conclusion, anthropogenic disturbance affects offspring quality rather than quantity, whereas agricultural practices affect both life history traits

A 10 Year Survey on Childhood CNS Tumors

AbstractObjectiveTumors of the central nervous system constitute the largest group of solid neoplasms in children and are second only to leukemia in their overall frequency during childhood. The main purpose of the present study is to determine the incidence, age, sex, location and histological diagnosis of CNS tumors in children, less than 15 years of age, in the Mofid Children's Hospital, in the past 10 years. Materials and MethodsIn this descriptive retrospective study we reviewed the medical records of 143 children with diagnosis of CNS tumors admitted during the past 10 years in neurology and surgery departments of Mofid Children's Hospital between the years 1996 and 2006.ResultsDuring the 10 year study period, CNS tumor was diagnosed in 143 patients; of these tumors, 119 were intracranial and 58 were intraspinal; 51.3% of brain tumors were located in the supratentorial and 48.7% in the infratentorial regions. The most common intracranial neoplasms were astrocytic tumors (36.8%), embryonal tumors (31.1%) and ependymal tumors (13.4%). Of the intraspinal neoplasms the most frequently noted were embryonal tumors(37.5%), mesenchymal meningothelial tumors (20.8%), followed by astrocytic tumors (16.7%). The median age at diagnosis was 8.9 ± 4.1 years with a male to female ratio of 1.4:1 (PConclusionBrain tumors in children constitute a diverse group in terms of incidence,distribution and histopathological diagnosis.

Corticosterone promotes scramble competition over sibling negotiation in Barn Owl nestlings (Tyto alba)

In species with parental care, siblings compete for access to food resources. Typically, they vocally signal their level of need to each other and to parents, and jostle for the position in the nest where parents deliver food. Although food shortage and social interactions are stressful, little is known about the effect of stress on the way siblings resolve the conflict over how food is shared among them. Because glucocorticoid hormones mediate physiological and behavioral responses to stressors, we tested whether corticosterone, the main glucocorticoid in birds, modulates physical and vocal signaling used by barn owl siblings (Tyto alba) to compete for food. Although corticosterone-implanted (cort-) nestlings and placebo-nestlings were similarly successful to monopolize food, they employed different behavioral strategies. Compared to placebo-nestlings, cort-individuals reduced the rate of vocally communicating with their siblings (but not with their parents) but were positioned closer to the nest-box entrance where parents predictably deliver food. Therefore, corticosterone induced nestlings to increase their effort in physical competition for the best nest position at the expense of investment in sib-sib communication without modifying vocal begging signals directed to parents. This suggests that in the barn owl stress alters nestlings' behavior and corticosterone could mediate the trade-off between scramble competition and vocal sib-sib communication. We conclude that stressful environments may prevent the evolution of sib-sib communication as a way to resolve family conflicts peacefully