Showing papers by "Ido Izhaki published in 2010"
TL;DR: It is shown for the first time that fish of various species and habitats contain V. cholerae in their digestive tract, and evidence from the literature suggests that fish are reservoirs of V. Cholerae.
Abstract: Vibrio cholerae, the etiologic agent of cholera, is autochthonous to various aquatic environments, but despite intensive efforts its ecology remains an enigma. Recently, it was suggested that copepods and chironomids, both considered as natural reservoirs of V. cholerae, are dispersed by migratory waterbirds, thus possibly distributing the bacteria between water bodies within and between continents. Although fish have been implicated in the scientific literature with cholera cases, as far as we know, no study actually surveyed the presence of the bacteria in the fish. Here we show for the first time that fish of various species and habitats contain V. cholerae in their digestive tract. Fish (n = 110) were randomly sampled from freshwater and marine habitats in Israel. Ten different fish species sampled from freshwater habitats (lake, rivers and fish ponds), and one marine species, were found to carry V. cholerae. The fish intestine of Sarotherodon galilaeus harboured ca. 5 x 10(3)V. cholerae cfu per 1 gr intestine content-high rates compared with known V. cholerae cfu numbers in the bacteria's natural reservoirs. Our results, combined with evidence from the literature, suggest that fish are reservoirs of V. cholerae. As fish carrying the bacteria swim from one location to another (some fish species move from rivers to lakes or sea and vice versa), they serve as vectors on a small scale. Nevertheless, fish are consumed by waterbirds, which disseminate the bacteria on a global scale. Moreover, V. cholerae isolates had the ability to degrade chitin, indicating a commensal relationship between V. cholerae and fish. Better understanding of V. cholerae ecology can help reduce the times that human beings come into contact with this pathogen and thus minimize the health risk this poses.
155 citations
TL;DR: A new hypothesis is outlined, suggesting that chemically protected galls which are also conspicuous are aposematic, and this paper discusses predictions, alternative hypotheses and experimental tests of this hypothesis.
Abstract: Galls are abnormal plant growth induced by various parasitic organisms, mainly insects. They serve as “incubators” for the developing insects in which they gain nutrition and protection from both abiotic factors and natural enemies. Galls are typically armed with high levels of defensive secondary metabolites. Conspicuousness by color, size and shape is a common gall trait. Many galls are colorful (red, yellow etc.) and therefore can be clearly distinguished from the surrounding host plant organs. Here we outlined a new hypothesis, suggesting that chemically protected galls which are also conspicuous are aposematic. We discuss predictions, alternative hypotheses and experimental tests of this hypothesis.
67 citations
TL;DR: It is suggested that the higher nest box occupation and number of nestlings fledged was probably due to the lower temperatures in those boxes, an important factor in a hot/arid environment, although alternative explanations are also considered.
Abstract: To date, nest orientation and location in hole-nesting birds have been studied mainly in temperate regions and in diurnal cavity breeders. Here we studied the effect of exposure, orientation, and habitat on nest box occupation and breeding success of Barn Owls in a semi-arid environment. The occupation of nest boxes varied with exposure and orientation. A higher percentage of occupation and more Barn Owl nestlings per breeding attempt were found in nest boxes located in the shade than in the sun, and in those facing east/north rather than other directions. The temperature in the nest boxes varied, being lowest in those located in the shade and in those facing east. Nest boxes located in crop fields fledged more young per breeding attempt than those located in date plantations. We suggest that the higher nest box occupation and number of nestlings fledged was probably due to the lower temperatures in those boxes, an impor- tant factor in a hot/arid environment, although alternative explanations are also considered.
51 citations
TL;DR: To determine the normal level of the conus medullaris of the spinal cord of normal fetuses at 20 to 24 weeks' gestation using abdominal sonography, abdominal sonographers are used.
Abstract: Objective To determine the normal level of the conus medullaris (CM) of the spinal cord of normal fetuses at 20 to 24 weeks’ gestation using abdominal sonography. Methods Using a 4 to 8 MHz ultrasound abdominal transducer, CM was imaged in the midsagittal plane with the fetal spine facing toward the transducer. The CM ending level was located by counting the vertebrae caudal starting at T12, which was identified by lowest fetal rib. The CM locations were defined according to their positions relative to the vertebrae. Results One hundred and ten consecutive pregnant women were included in the study. The CM was clearly demonstrated in 78 (71%) of these cases. Most of the scanned fetuses had the CM ending height adjacent to vertebrae L2, L2–3 inter-space and L3 (73/78, 93%). The L1–2, L2, L2–3, and L3 vertebral groups did not differ in mean gestational weeks, maternal age, or fetal gender. Conclusion The level of the CM can be determined at 20 to 24 weeks’ gestation in about 70% of fetuses. Most of the scanned fetuses had the CM ending height adjacent to vertebrae L2, L2–3 vertebral space, and L3 (73/78, 93%). When detected lower than the third lumbar vertebra it should prompt prenatal and postnatal surveillance. Copyright 2010 John Wiley & Sons, Ltd.
36 citations
TL;DR: A novel and simple multivariate score using clinical and basal endocrine and sonographic parameters has a distinctive prediction of low ovarian reserve in infertile women undergoing assisted reproductive technology treatment and has the potential to predict clinical implantation and pregnancy rates in women with low and good ovarian reserve.
35 citations
TL;DR: Early and short follicular Gn RH antagonist supplementation using flexible GnRH antagonist treatment improves the meiotic status and competence of retrieved oocytes and seems that early and short pituitary shutdown has the potential to improve clinical results in IVF-ET GnRH antagonists cycles.
28 citations
TL;DR: The effects of competition and risk of predation on secondary cavity breeders were examined using an experimental design manipulating two nest entrance sizes (large entrances allowed Barn Owls to enter, while the small entrances excluded them), and Jackdaws probably did not breed in large entrance nest boxes due both to exploitation competition and the risk of interference competition.
Abstract: The effects of competition and risk of predation on secondary cavity breeders were examined between the 2008 and 2009 breeding seasons using an experimental design manipulating two nest entrance sizes (large entrances allowed Barn Owls (Tyto alba) to enter, while the small entrances excluded them). During the 2009 breeding season, the entrance sizes of nest boxes were exchanged, so that if during one year a nest box in a particular location had a small entrance, the second year it had a large entrance and vice versa. Barn Owls and Eurasian Kestrels (Falco tinnunculus) occupied 67.3 and 17.3%, respectively, of large entrance nest boxes. Significantly more Jackdaws (Corvus monedula), House Sparrows (Passer domesticus) and Scops Owls (Otus scops) bred in nest boxes with small than with large entrances. After nest box entrance sizes were exchanged, Barn Owls and smaller species did not breed in the same nest boxes with the new entrance size. Jackdaws probably did not breed in large entrance nest boxes due both to exploitation competition (Barn Owls and Eurasian Kestrels occupied the majority of large entrance nest boxes), and may also have avoided empty nest boxes because of the risk of interference competition; whereas smaller species may have also avoided large entrance nest boxes due to risk of predation.
20 citations
TL;DR: A discriminant analysis model is presented, according to which vulnerable individuals may be predicted at near 100% probability 7 days after arrival, and may be a reliable tool for an early prediction of subclinical signs of BRD.
Abstract: Bovine respiratory disease complex (BRD), a major economic concern to the beef cattle industry all over the world, is triggered by physical, biological and psychological stresses. It is becoming noticeable that the key to reducing BRD appears to be centered at reducing the response to stress. The aims of the present study were to detect individual variations in the stress response of newly received young calves through their leukocyte heat shock protein (Hsp) response, selected neutrophil-related gene expression and oxidative stress, and relate them to pulmonary adhesions at slaughter, an indicative sign of clinical and subclinical episodes of BRD at an early age. Differential expression patterns of Hsp60 and Hsp70A1A were revealed in newly received calves 1 h, 5 h and 1 day after arrival, distinguishing between stress-responsive and non-stress-responsive individuals. Plasma cortisol was also indicative of stress-responsive and non-stress-responsive individuals, 1 h and 5 h after arrival. At the longer term, β-glycan levels were highest 7 days after arrival and significantly correlated with an adhesion-free phenotype at slaughter. Oxidative stress responses, measured through the oxidation products of the exogenous linoleoyl tyrosine (LT) marker, revealed that hydroperoxidation and epoxidation of membranes may readily occur. Based on the LT oxidation products and levels of β-glycan, we present a discriminant analysis model, according to which vulnerable individuals may be predicted at near 100% probability 7 days after arrival. Since clinical signs of BRD may often go undetected in feedlot calves, such a model, after its examination in large-scale experiments, may be a reliable tool for an early prediction of subclinical signs of BRD.
16 citations
TL;DR: The notion that infertile women conceiving singleton pregnancies after ART are a priori at an increased hypercoagulation state is supported, as are the findings that Protein C Global assay levels decline gradually during pregnancy in women who conceived naturally, as well as in infertiles who conceived after ART treatment.
7 citations
TL;DR: Great Tits occupied both types of nest boxes, but significantly fewer pairs breeding in nest boxes with enlarged holes succeeded in fledging at least one young, probably due to their eviction by the larger House Sparrows.
Abstract: We studied use of nest boxes by Great Tits (Parus major) in rural village gardens in a semi-arid area. Great Tits occupied 46.6% of the nest boxes, and used nest boxes within higher tree densities and with more tree species in the vicinity. Breeding success was greater in nest boxes with higher plant density, more plant species, and greater height of trees in the vicinity of the nest. The presence of children or dogs (Canis lupus familiaris) near nest boxes did not affect breeding parameters. Syrian Woodpeckers (Dendrocopos syriacus) enlarged 38.0% of nest box entrances during the first year. House Sparrows (Passer domesticus) occupied 41.0% of the nest boxes with enlarged holes and none of those with normal holes. Great Tits occupied both types, but significantly fewer pairs breeding in nest boxes with enlarged holes succeeded in fledging at least one young, probably due to their eviction by the larger House Sparrows.
4 citations
TL;DR: Agarwal et al. as discussed by the authors present results of a study that determine whether the lechuzas Asio otus and the halcon Falco tinnunculus use cestas artificiales for anidar, and if estas aves seleccionan un tamano particular de cesta.
Abstract: ?EL TAMANO DE LA ESTRUCTURA DE LOS NIDOS AFECTA EL DESEMPENO REPRODUCTIVO DE Asio otus Y Falco tinnunculus? Los nidos artificiales son elementos importantes en muchos estudios cientificos y para la conservacion de especies de aves. Aqui presentamos los resultados de un estudio que determino si la lechuza Asio otus y el halcon Falco tinnunculus utilizan cestas artificiales para anidar, y si estas aves seleccionan un tamano particular de cesta. Durante nuestro estudio, 36.8% de las cestas de anidacion que colocamos fueron ocupadas por las dos especies. Las lechuzas ocuparon los dos tipos de tamano de cesta, de 30 cm y 40 cm de diametro, pero fueron mas exitosas en producir polluelos prevolantones en las cestas de 30 cm (tanto el numero de crias como el porcentaje de crias por nido fueron mayores). Los halcones tambien ocuparon los dos tamanos en proporciones similares, pero no encontramos diferencias en sus parametros reproductivos entre parejas que criaron en los dos tipos de cestas de anidacion. Especulam...
TL;DR: As stated in White’s comment, signaling of gall coloration is indeed reasonable; the aposematic gall hypothesis should be considered as a legitimate working hypothesis that awaits proper examination.
Abstract: White (2010) commented on our hypothesis about aposematic galls (Inbar et al. 2010) and we are pleased for the opportunity to further discuss this still enigmatic, common, though variable phenomenon of conspicuous (mainly colorful) galls. White proposed an explanation for gall coloration based on the assumed senescing status of the galled tissue. Although the feasibility and generality White’s physiological/nutritional hypothesis deserves a separate, thorough discussion, one should keep in mind that red and yellow pigmentation is not synonymous with senescence. Many young flowers are red and yellow (Lee 2007) and many young leaves are red (Richards 1996). Galls do not necessarily senesce earlier or stop the development of the galled tissue. As posited in our paper, we can clearly accept that gall coloration could have evolved along physiological routes such as stress-related pigmentation, or pleiotropic effects of defensive genes. As such, White’s hypothesis may be relevant for at least some gall-formers. There are numerous gall species, of which probably thousands are colorful. They represent many repeated but independent events of evolution of the galling habit. They are found in different environments and on a great variety of plant taxa, host life stages and organs. It is not reasonable to assume that all these galls have only a single and ubiquitous function for their conspicuous coloration. Indeed, in our paper (Inbar et al. 2010) we discussed several alternative explanations for this phenomenon. Moreover, gall conspicuity and signaling is not dependent only on colors, but also on size, shape (e.g., Fig. 1) and probably odor. A single explanation, such as the level of light exposure for example, cannot explain the variation in gall coloration as colorful galls are also common in dark microhabitats (Lupo, Izhaki and Inbar, in preparation). Whatever the reasons for the evolution of gall coloration, it is still necessary to explain its variability and maintenance. It is widely accepted that gall formers control gall traits (‘‘extended phenotype’’). Thus, if conspicuity would have a strong negative effect on gall survival (e.g., by attracting predators and parasitoids) we would expect a strong selection against it. The common conspicuousness of galls is evident for its potential beneficial role; or at least for lack of strong selection against it. An interesting example of the sophisticated ability of gall-inducers has recently been reported by Tooker et al. (2008). They demonstrated that gall-forming insects can ‘‘silence’’ the emission of conspicuous odor (volatiles) from the galled tissue, which thus reduces its detection by potential enemies. As stated in White’s comment, signaling of gall coloration is indeed reasonable; the aposematic gall hypothesis should therefore be considered as a legitimate working hypothesis that awaits proper examination. Handling Editor: Heikki Hokkanen.