bluuebunny/crossref_metadata_2025 huggingface dataset:
Cloning and characterization of a candidate nutritive glycoprotein from the albumen gland of the freshwater snail, Helisoma duryi (Mollusca: Pulmonata)
Authors: Mukai Spencer T. , Hoque Tafazzal , Morishita Fumihiro , Saleuddin A. Saber M.
Published: August 2010

Abstract. The albumen gland is a female accessory sex gland that synthesizes and secretes perivitelline fluid around pulmonate eggs. The perivitelline fluid is composed of mainly galactogen and proteins, and is thought to provide nourishment to the embryos during development. We have previously identified the major secretory protein of the albumen gland of the freshwater snail Helisoma duryi as a native glycoprotein of ∼288 kDa, consisting of four 66‐kDa subunits. In this study, the major albumen gland protein in H. duryi was purified, cloned, and the full‐length cDNA sequence determined. Nucleotide sequence analysis revealed that the albumen gland protein (HdAGP) shared 83% identity with a partial cDNA sequence from a developmentally regulated albumen gland protein in Biomphalaria glabrata. The HdAGP mRNA was detected by RT‐PCR in the albumen gland, ovotestis, mantle and digestive gland. SDS‐PAGE analysis of the albumen gland protein in egg masses at different stages of development showed that the amount of HdAGP steadily decreased during embryogenesis, suggesting its possible catabolism by the developing embryos. Protein domain searches suggested that the HdAGP shared limited sequence identity, and adopted a similar three‐dimensional conformation to the bactericidal, permeability increasing, protein family, raising the possibility of a potential bactericidal function for this important reproductive/developmental protein.
Fixed focal‐length optics in pulmonate snails (Mollusca, Gastropoda): squaring phylogenetic background and ecophysiological needs (II)
Authors: Gál József , Bobkova Marina V. , Zhukov Valery V. , Shepeleva Irina P. , Meyer‐Rochow V. Benno
Published: August 2010

Abstract. Our results suggest that freshwater pulmonates like Lymnaea stagnalis, Radix peregra, Physa fontinalis, and Planorbarius corneus have inherited from their terrestrial ancestors eyes with a spherical, immobile lens with fixed focal‐length optics. Unable to change the dioptric apparatus to form an image under water, modifications to the retina had to occur if sharp vision was required. Computer‐assisted calculations and 3‐D eye reconstructions demonstrate that the photoreceptors in the deeper, ventral pit are in a position to perceive focused images under water. Vision in air, however, would favour photoreceptive cells located in the shallower, dorsal pit. On the basis of histological, ethological, and optical comparisons, we conclude that the eyes in L. stagnalis and R. peregra, species that are known to escape and seek temporary refuge above the water surface, are well adapted to function in water as well as air, but that the eyes in P. fontinalis and Pl. corneus are less modified from those of their terrestrial ancestors. We also conclude that good resolving power may be of greater importance in the aquatic pulmonates than the terrestrial species, since the former have to locate thin, vertical stems of reeds and sedges to ascend in order to reach the surface to breathe.
Barriers to outcrossing success in the primarily self‐fertilizing clam shrimp, Eulimnadia texana (Crustacea, Branchiopoda)
Authors: Weeks Stephen C. , Marquette Cortney L. , Latsch Elizabeth
Published: August 2010

Abstract. The expected proportion of males in androdioecious populations (those comprised of males and hermaphrodites) largely depends on the fertilization opportunities of males. If male mating opportunities are low due to restricted access to hermaphroditic eggs, then populations will be hermaphrodite‐biased. Hermaphrodites have two mechanisms available to limit male mating success: (1) pre‐mating barriers to outcrossing, in which hermaphrodites choose not to pair with males and (2) post‐mating barriers to outcrossing, in which hermaphrodite sperm has greater access to eggs than male sperm. In this study, we measured male mating success in the androdioecious clam shrimp Eulimnadia texana when pre‐mating barriers to outcrossing were removed. These branchiopod crustaceans are small (5–8 mm), filter feeders that live in ephemeral pools in the deserts of the southwestern United States. Using genetic markers, we measured male mating success in laboratory experiments in two populations of these shrimp. We correlated mating success with clasping time, clasping during egg transfer, and male thrusting during egg transfer. Males fertilized an average of 24–40% of the hermaphrodites' eggs. Outcrossing success was positively correlated with clasping duration, and was nearly an order of magnitude higher for males thrusting during egg transfer relative to thrusting at other times during pairing. Because these estimates of mating success were similar to previously reported estimates (in which both pre‐ and post‐mating barriers to outcrossing were potentially important), we deduced that pre‐mating barriers to outcrossing do not greatly decrease male outcrossing success in E. texana; the low fertilization (25–50% of available eggs) by males is thus due to post‐mating barrier(s) to outcrossing.
Ciliary feeding structures and particle capture mechanism in the freshwater bryozoan Plumatella repens (Phylactolaemata)
Authors: Riisgård Hans Ulrik , Nielsen Kasper Kollerup , Fuchs Judith , Rasmussen Bo Fønss , Obst Matthias , Funch Peter
Published: August 2010

Abstract. In contrast to marine bryozoans, the lophophore structure and the ciliary filter‐feeding mechanism in freshwater bryozoans have so far been only poorly described. Specimens of the phylactolaemate bryozoan Plumatella repens were studied to clarify the tentacular ciliary structures and the particle capture mechanism. Scanning electron microscopy revealed that the tentacles of the lophophore have a frontal band of densely packed cilia, and on each side a zigzag row of laterofrontal cilia and a band of lateral cilia. Phalloidin‐linked fluorescent dye showed no sign of muscular tissue within the tentacles. Video microscopy was used to describe basic characteristics of particle capture. Suspended particles in the incoming water flow, set up by the lateral ‘pump’ cilia on the tentacles, approach the tentacles with a velocity of 1–2 mm s‐1. Near the tentacles, the particles are stopped by the stiff sensory laterofrontal cilia acting as a mechanical sieve, as previously seen in marine bryozoans. The particle capture mechanism suggested is based on the assumed ability of the sensory stiff laterofrontal cilia to be triggered by the deflection caused by the drag force of the through‐flowing water on a captured food particle. Thus, when a particle is stopped by the laterofrontal cilia, the otherwise stiff cilia are presumably triggered to make an inward flick which brings the restrained particle back into the downward directed main current, possibly to be captured again further down in the lophophore before being carried to the mouth via the food groove. No tentacle flicks and no transport of captured particles on the frontal side of the tentacles were observed. The velocity of the metachronal wave of the water‐pumping lateral cilia was measured to be ∼0.2 mm s‐1, the wavelength was ∼7 μm, and hence the ciliary beat frequency estimated to be ∼30 Hz (∼20 °C). The filter feeding process in P. repens reported here resembles the ciliary sieving process described for marine bryozoans in recent years, although no tentacle flicks were observed in P. repens. The phylogenetic position of the phylactolaemates is discussed in the light of these findings.
Resource allocation in ascidians: reproductive investment vs. other life‐history traits
Authors: Tarjuelo Isabel , Turon Xavier
Published: August 2010

Abstract. To determine patterns of resource allocation among ascidians, we studied 16 colonial and solitary species. We measured investment in reproductive vs. structural material (tunic) both in terms of weight and caloric content, as well as fecundity and degree of larval complexity in the colonial species. Measurements in weight and caloric content were highly correlated in the species studied. A wide range of investment in reproduction was found. Tunic production was related to the growth form of the species, stolonic and solitary species investing less in tunic than massive species, but no significant relationship was found between investment in tunic production vs. reproduction. In colonial species we found that in species with small zooid size, the reproductive investment per zooid was significantly higher. There was a significant negative relationship between investment in reproduction and fecundity. We also found a significant relationship between reproductive investment and larval complexity. The overall trend was that species with low fecundity had large complex larvae and invested the most energy in reproduction.
Population structure and reproductive biology of Pygospio elegans (Polychaeta: Spionidae) on an intertidal sandflat, Firth of Forth, Scotland
Authors: Bolam Stefan G.
Published: August 2010

Abstract. The population structure and reproductive biology of a population of the spionid polychaete Pygospio elegans was studied at Drum Sands, Firth of Forth, Scotland, between March 1997 and February 1998.P. elegans was numerically dominant at the site and exhibited a population density increase through the sampling period. The population showed a seasonal pattern with two acute periods of recruitment during the year, one in spring and one in winter. Planktotrophic larvae were the only larval type produced throughout the sampling period. Larvae were released at the 3–5 setiger stage and settled at a size of 18–22 setigers. The spring recruits grew at a rate of 23 setigers per month, reaching sexual maturation size during September of the same year. The adult sex ratio was female‐biased throughout the study period (mean = 2.99:1 ± 0.51). When female:ripe male sex ratios were highest (summer and fall), the proportion of females brooding larvae decreased suggesting that sexual reproduction is seasonal. Asexual reproduction was not observed in the population of P. elegans on Drum Sands. These findings suggest that a high degree of variability is a trait of the reproductive biology of P. elegans..
Susceptibility of California gastropods to an introduced South African sabellid polychaete, Terebrasabella heterouncinata
Authors: Culver Carolynn S. , Kuris Armand M.
Published: August 2010

Abstract. The outer surfaces of the shells of living marine gastropods are often colonized by other organisms. However, only one species, the sabellid worm Terebrasabella heterouncinata, is able to settle in the aperture of living gastropods. Native to South Africa, and introduced to California, this worm is a pest of abalone aquaculture and has been a threat to native gastropods in California. We investigated the intrinsic susceptibility of 15 marine gastropods from California to this apertural fouling organism. Intrinsic susceptibility was significantly different among gastropod species. Overall, caenogastropods tended to be more resistant than were the vetigastropods and patellogastropods. This suggests that variability in susceptibility could be due to characteristics associated with closely related gastropod hosts. However, this only partially explained the variation in susceptibility to individuals of T. heterouncinata. Intrinsic susceptibility was not associated with potential host species from similar habitats. We discuss host susceptibility to T. heterouncinata, including implications for potential control of this pest species, and for understanding factors enabling this polychaete to inhabit the apertural region, an area typically free of all other epibionts.
Morphology and distribution of antennular setae of scyllarid lobsters (Scyllarides aequinoctialis, S. latus, and S. nodifer) with comments on their possible function
Authors: Weisbaum Dolores , Lavalli Kari L.
Published: August 2010

Abstract. Lateral flagella of the antennules of scyllarid lobsters were examined for setal morphology and distribution via scanning electron microscopy. Setal distribution patterns were mapped directly for 3 regions of the antennule (base, tuft, and tip) and analyzed for differences: (1) between left and right antennules, (2) between males and females within a species, and (3) among species by comparing counts of setae per annulus in the ventral tuft region only. Six types of antennular setae were identified based on their external morphology: aesthetases, simple, modified simple, asymmetric, hemi‐plumose, and toothbrush setae. These different types were organized in a clear pattern over the ventral and dorsal surfaces of the lateral flagella of the antennule. Aesthetase, asymmetric, modified simple, and hemi‐plumose setae were found only on annuli in the tuft region between the distal and proximal ends of the flagellum. Simple setae were found on all annuli of all regions of the antennule, and toothbrush setae were mainly concentrated on all annuli of the base region and on proximal annuli of the tuft region. All species of scyllarids examined had the same general pattern of setal distribution and no differences were found between left and right, or male and female antennules. Similar setae located on the lateral antennules of species from the families Nephrophidae and Palinuridae (clawed and spiny lobsters) have been previously described as chemo‐ and/or mechanoreceptive for use in distance chemoreception (i.e., detection and orientation to olfactory stimuli). Based on work on clawed and spiny lobsters, we predict that the aesthetases on slipper lobsters have a chemoreceptive function and that simple and toothbrush setae may have a bimodal chemo‐ and mechanoreceptive function.
First observations on egg release in the oviparous sponge Chondrilla nucula (Demospongiae, Chondrosida, Chondrillidae) in the Mediterranean Sea
Authors: Sidri Marzia , Milanese Martina , Bümmer Franz
Published: August 2010

Abstract. The reproduction of the demosponge Chondrilla nucula in Portofino (Ligurian Sea, Italy) was studied during August 2001. Eighteen individuals were sampled and examined with light microscopy for the presence of gametes, and 5 individuals carrying oocytes were found. In addition to microscopic observations, reproductive individuals could be easily identified as female even at the macroscopic level because of the presence of a grayish layer in the mesohyl where oocytes were concentrated. Oogenesis resulted in modifications of the external sponge morphology and of the aquiferous system. Approximately one‐third of the sponge body was filled with oocytes with the consequent disappearance of choanocyte chambers in the reproductive portion of the sponge. Under laboratory conditions, we obtained fertilized eggs from females and observed the first stages of embryonic development. Our observations suggest that fertilization in specimens of Chondrilla nucula occurs internally and not in the water. During the 2 years following these observations, no reproductive specimens were found among the same population during the reported reproductive period.
Polarized light microscopy, variability in spider silk diameters, and the mechanical characterization of spider silk
Authors: Blackledge Todd A. , Cardullo Richard A. , Hayashi Cheryl Y.
Published: August 2010

Abstract. Spider silks possess a remarkable combination of high tensile strength and extensibility that makes them among the toughest materials known. Despite the potential exploitation of these properties in biotechnology, very few silks have ever been characterized mechanically. This is due in part to the difficulty of measuring the thin diameters of silk fibers. The largest silk fibers are only 5–10 μm in diameter and some can be as fine as 50 nm in diameter. Such narrow diameters, coupled with the refraction of light due to the anisotropic nature of crystalline regions within silk fibers, make it difficult to determine the size of silk fibers. Here, we report upon a technique that uses polarized light microscopy (PLM) to accurately and precisely characterize the diameters of spider silk fibers. We found that polarized light microscopy is as precise as scanning electron microscopy (SEM) across repeated measurements of individual samples of silk and resulted in mean diameters that were ∼0.10 μm larger than those from SEM. Furthermore, we demonstrate that thread diameters within webs of individual spiders can vary by as much as 600%. Therefore, the ability of PLM to non‐invasively characterize the diameters of each individual silk fiber used in mechanical tests can provide a crucial control for natural variation in silk diameters, both within webs and among spiders.
Seasonal periodicity of enteric nitric oxide synthesis and its regulation in the snail,Helix lucorum
Authors: Röszer Tamás , Kiss‐Tóth Éva , József Szentmiklósi A. , Bánfalvi Gáspár
Published: August 2010

Abstract.The snailHelix lucorumhas been used as a model to study the adaptation of a nitric oxide (NO)‐forming enteric neural network to the long‐term resting period of summer estivation or winter hibernation. Quantification of the NO‐derived nitrite established that NO formation is confined to the nitric oxide synthase (NOS)‐containing myenteric network of the mid‐intestine. In active snails but not in resting snails, NO production could be enhanced by the NOS substratel‐arginine (l‐ARG, 1 mM). We followed the enteric NO synthesis in a snail population kept at natural conditions for 1 year. Our findings indicate that NO synthesis was depressed in July during entry to the estivation, had a peak in autumn before hibernation, and finally was reduced during hibernation. Monoamines (histamine, serotonin, and adrenalin) could inhibit the NO liberation in active snails. Cofactors of NOS (β‐NADPH, β‐NAD, FAD, FMN, Ca2+, TH4) did not alter the low nitrite production in hibernating snails. We conclude that enteric NO synthesis inH. lucorumhas a regular seasonal periodicity following the annual physiological cycles of terrestrial snails. During estivation or hibernation, NOS activity is blocked. Monoamines, the levels of which are elevated during hibernation, can trigger decreased NOS activity. The reduced activity of NOS cannot be restored by the administration of NOS cofactors; therefore, their absence cannot be the cause of the temporarily blocked L‐ARG/NO conversion ability of NOS.
Egg‐feeding in the freshwater piscicolid leechCystobranchus virginicus(Annelida, Hirudinea)
Authors: Light Jessica E. , Fiumera Anthony C. , Porter Brady A.
Published: August 2010

Abstract.Leeches are common terrestrial and aquatic annelids, parasitizing or feeding on a wide range of host taxa. Here we report evidence for an unusual feeding behavior of egg‐feeding in the piscicolid leechCystobranchus virginicus. We identified distended specimens ofC. virginicusin the nests of at least 4 different fish species:Campostoma anomalum, Moxostoma carinatum, Moxostomasp. (eitherM. anisurumand/orM. breviceps), andNocomis leptocephalus. We collected a total of 41 leeches from the nests of these host species and documented at least 1 leech in 19 of 55 nests (35%), with many sites containing multiple leeches. Individuals ofC. virginicuswere not identified feeding on any of the 41 adult specimens ofMoxostomaspp. or the 635 adult specimens ofNocomis leptocephalusexamined, and were never found in the absence of active host spawning (26 sites). These results are consistent with individuals ofC. virginicusbeing an opportunistic or possibly even an obligate egg‐feeder, potentially timing their own reproductive activities with the spawning of their fish hosts. The current distribution ofC. virginicushas been expanded to include North Carolina, South Carolina, and Tennessee. The potential for leech species to induce mortality in developing fish eggs could be a concern for fish conservation and merits further investigation.
On the environmental scanning electron microscope for taxonomic purposes
Authors: Valdecasas Antonio G. , Camacho Ana I.
Published: August 2010

Abstract. Realism, resolution, and portrayal of spatial relationships are three conditions for iconic representations in formal taxonomic descriptions. Hand drawing is a painstaking and time‐consuming technique. The environmental scanning electron microscope (ESEM) is an alternative that can provide detailed images without damaging the specimen, thus allowing it to be used for further study either in light microscopy or molecular analysis. In this work, we evaluate the suitability of ESEM for basic taxonomic study with specimens of two arthropods groups: water mites and bathynelids. The ESEM provides enough resolution to classify even to the species level. Different kinds of curatorial adhesive strips were used with satisfactory results. We foresee that the ESEM will be a common taxonomic tool in the near future.
Fate of bacteria,Aeromonas caviae, in the midgut of the housefly,Musca domestica
Authors: Nayduch Dana , Pittman Noblet Gayle , Stutzenberger Fred J.
Published: August 2010

Abstract.The role of houseflies as agents in the spread of bacterial diseases has been thoroughly investigated, yet the fate of bacteria ingested by flies has not. We examined the physical location of the bacterial enteropathogenAeromonas caviaein the midgut of laboratory‐reared adult houseflies. Food ingested by houseflies was separated from the midgut epithelium by a double‐layered peritrophic matrix (PM). The inner PM intimately enveloped the food as fecal pellets (food boluses), while the outer PM appeared as a long continuous tube. In flies fed a suspension ofA. caviae, live bacteria were not observed within the inner PM, but were compartmentalized between folds of the PM in the inter‐PM space. Similar observations were made for flies fed a suspension ofSerratia liquefaciensand for highly contaminated feral flies. Isolates of bothA. caviaeandS. liquefacienswere chitinolytic (as demonstrated by clearing zones on chitin agar), but the potential role of bacterial enzymes in the alteration of PM morphology or formation needs further investigation.
Reproductive morphology, mating behavior, and spawning ecology of cephalaspid sea slugs (Aglajidae and Gastropteridae)
Authors: Anthes Nils , Michiels Nico K.
Published: August 2010

Abstract. Several recent experimental studies have assessed the behavioral reproductive ecology of four opisthobranch species belonging to the families Aglajidae and Gastropteridae (Cephalaspidea). In order to extend the scope of this earlier work, here we document the reproductive morphology and behavior of 36 taxa belonging to the same two sea slug families. Measurements focus on insemination patterns, spawning characteristics, as well as the size and shape of male and female reproductive organs (i.e., prostate, penis, bursa copulatrix, seminal receptacle). We found that behavioral and morphological traits vary considerably between species, even between closely related taxa. Mating behavior covers the full spectrum from unilateral to simultaneously reciprocal insemination and includes putatively antagonistic mechanisms such as hypodermic injection in some cases. With respect to morphology, particularly great variation was present in traits related to the male sexual function, such as prostate size and penis type. In traits associated with the female function, noticeable variation in those traits accessible for measurement was limited to the relative size of the sperm‐digesting bursa copulatrix. These data provide the basis for future comparative analyses on the evolution of reproductive characters in a phylogenetic context. We further explore the relationship between characteristics and body size. Our data corroborate previous findings that in species with exclusively planktotrophic development, investment per embryo (using mean egg diameter per species as a proxy) is independent of mean species body size. In contrast to egg size, spawn weight and the number of eggs per spawn tightly increased with body size, both within and among species. Hence, larger individuals among planktotrophs increased reproductive investment by increasing offspring quantity rather than investing more into each single offspring. Comparably large eggs with few eggs per spawn in our only two species with facultatively intracapsular metamorphosis are also consistent with findings in other opisthobranchs.
Developmental patterns of the hermaphroditic gonad in dicyemid mesozoans (Phylum Dicyemida)
Authors: Furuya Hidetaka , Tsuneki Kazuhiko
Published: August 2010

Abstract. The development of the hermaphroditic gonad, the infusorigen, was studied in fixed specimens of 16 species belonging to four genera (Conocyema, Dicyema, Dicyemennea, and Pseudicyema) of dicyemid mesozoans. In addition, the literature on the cell lineages of infusorigens of eight other species was reviewed. After an agamete (axoblast) undergoes an unequal first division, excluding a small cell (the paranucleus), the resulting large cell divides to form the infusorigen. Five infursorigen cell lineage patterns can be identified: type I, both the first oogonium and the first spermatogonium are produced at the third division; type II, the first spermatogonium is produced at the second division and the first oogonium is produced at the third division; type III, the first spermatogonium is produced at the second division and the first oogonium is produced at the fourth division; type IV, the first oogonium is produced at the second division and the first spermatogonium is produced at the third division; and type V, the first oogonium is produced at the second division and the first spermatogonium is produced at the fourth division. Later development is similar in members of all genera. Mature infusorigens are similarly organized in all species examined. Sizes of agametes and infusorigen axial cells, the number of infusorigens, and the type of reproductive strategy were not correlated with infusorigen developmental patterns or cell lineage patterns.
Ultrastructural changes in the midgut epithelium of the first larva of Allacma fusca (Insecta, Collembola, Symphypleona)
Authors: Rost‐Roszkowska Magdalena M. , Poprawa Izabela , Swiatek Piotr
Published: August 2010

Abstract. In the newly hatched larva in Allacma fusca, the midgut epithelium was fully developed and formed by flattened epithelial cells surrounding the yolk mass in the midgut lumen. Immediately after hatching, the first larva began to feed; the migut lumen was filled with the yolk mass and food (mainly algae). Regenerative cells typical of the developing midgut epithelium of many insects were not observed. Initially, midgut cells of the larva were cuboidal but became columnar in shape with distinct regionalization in the distribution of cell organelles. Furthermore, urospherites appeared in the midgut cell cytoplasm, i.e., structures characteristic for the midgut epithelium of insects having no Malpighian tubules. As a result, cells with the capacity for digestion, absorption, and excretion were observed to be completely formed in the first larval stage.
Climate Change, Uncertainty, and Adaptation: The Case of Irrigated Agriculture in the Murray–Darling Basin in Australia
Authors: Quiggin John , Adamson David , Chambers Sarah , Schrobback Peggy
Published: August 2010

Climate change is likely to have substantial effects on irrigated agriculture. Extreme climate events, such as droughts, are likely to become more common. These patterns are evident in median projections of climate change for the Murray–Darling Basin in Australia. Understanding climate change effects on returns from irrigation involves explicit representation of spatial changes in natural stocks (i.e., water supply) and their temporal variability (i.e., frequency of drought states of nature) and the active management responses to capital stocks represented by mitigation and alternative adaptation strategies by state of nature. A change in the frequency of drought will induce a change in the allocation of land and water between productive activities. In this paper, a simulation model of state‐contingent production is used to analyze the effects of climate change adaptation and mitigation. In the absence of mitigation, climate change will have severe adverse effects on irrigated agriculture in the Basin. However, a combination of climate mitigation and adaptation through changes in land and water use will allow the maintenance of agricultural water use and environmental flows.

Le changement climatique risque d’avoir des répercussions considérables sur l’agriculture irriguée. Les phénomènes climatiques extrêmes, tels que les sécheresses, risquent de devenir plus fréquents. Ces phénomènes sont mis en évidence dans les projections médianes du changement climatique établies pour le bassin de Murray–Darling, en Australie. Pour comprendre les répercussions du changement climatique sur le rendement des cultures irriguées, il faut disposer d’une représentation explicite des changements spatiaux qui touchent les stocks naturels (c.‐à‐d. l’approvisionnement en eau) et de leur variabilité temporelle (c.‐à‐d. les états de la nature de la fréquence de la sécheresse) et assurer une gestion active des stocks de capital grâce à des stratégies d’atténuation et d’adaptation selon l’état de la nature. Une variation de la fréquence des sécheresses entraînera une modification de l’allocation des terres et de l’eau entre les activités de production. Dans le présent article, nous avons utilisé un modèle de simulation états‐contingences pour analyser les répercussions des stratégies d’atténuation du changement climatique et d’adaptation à ce changement. En l’absence de stratégies d’atténuation, le changement climatique aura des répercussions défavorables sur l’agriculture irriguée dans le Bassin. Toutefois, des stratégies d’atténuation combinées à des stratégies d’adaptation comprenant des changements dans l’utilisation des terres et de l’eau permettront de maintenir l’utilisation de l’eau à des fins agricoles et les débits environnementaux.
Was the progenitor of the Sagittarius stream a disc galaxy?
Authors: Peñarrubia Jorge , Belokurov Vasily , Evans N. W. , Martínez-Delgado David , Gilmore Gerard , Irwin Mike , Niederste-Ostholt Martin , Zucker Daniel B.
Published: August 2010

We use N-body simulations to explore the possibility that the Sagittarius (Sgr) dwarf galaxy was originally a late-type, rotating disc galaxy, rather than a non-rotating, pressure-supported dwarf spheroidal galaxy, as previously thought. We find that bifurcations in the leading tail of the Sgr stream, similar to those detected by the SDSS survey, naturally arise in models where the Sgr disc is misaligned with respect to the orbital plane. Moreover, we show that the internal rotation of the progenitor may strongly alter the location of the leading tail projected on the sky, and thus affect the constraints on the shape of the Milky Way dark matter halo that may be derived from modelling the Sgr stream. Our models provide a clear, easily tested prediction; although tidal mass stripping removes a large fraction of the original angular momentum in the progenitor dwarf galaxy, the remnant core should still rotate with a velocity amplitude ∼20 km s−1 that could be readily detected in future, wide-field kinematic surveys of the Sgr dwarf.
JUVENILITY AND PUNISHMENT: SENTENCING JUVENILES IN ADULT CRIMINAL COURT*
Authors: KURLYCHEK MEGAN C. , JOHNSON BRIAN D.
Published: August 2010

The study outlined in this article addressed a key limitation of prior research on the punishment of juveniles transferred to adult court by employing propensity score matching techniques to create more comparable samples of juvenile and young adult offenders. Using recent data from the Maryland State Commission on Criminal Sentencing Policy, it tested competing theoretical propositions about the salience of juvenile status in adult court. Findings indicate that even after rigorous statistical matching procedures, juvenile offenders are punished more severely than their young adult counterparts. We found no evidence that this “juvenile penalty” is exacerbated by an offender's race or gender, but it does vary starkly across offense type and mode of transfer, being driven primarily by drug crimes and discretionary waivers. The import of these findings is discussed as they relate to the future of juvenile justice policy regarding the continued use of juvenile transfer to adult court.
“BACK‐END SENTENCING” AND REIMPRISONMENT: INDIVIDUAL, ORGANIZATIONAL, AND COMMUNITY PREDICTORS OF PAROLE SANCTIONING DECISIONS*
Authors: LIN JEFFREY , GRATTET RYKEN , PETERSILIA JOAN
Published: August 2010

An understudied contributor to the massive growth of American incarceration is an increase in the practice of reimprisoning parolees through parole board revocations—now referred to as “back‐end sentencing.” To conduct the analyses outlined in this article, we use data from the California Parole Study to analyze the effects of three clusters of factors (parolees' characteristics, organizational pressures, and community conditions) on these sentences. Our analyses are informed by theories that have been used to explain “front‐end” (court) sentences, which center on the focal concerns of social‐control agents, labeling, and racial threat. Our results indicate that status characteristics—race/ethnicity and gender—affect the likelihood that criminal parole violators are reimprisoned. Moreover, certain “pivotal categories” of parolees—registered sex offenders and those who have committed “serious” or “violent” offenses—are much more likely to be returned to prison than others. Organizational pressure (prison crowding) also affects the likelihood of reimprisonment. Communities' political punitiveness affects the likelihood that technical violators are reimprisoned and that serious or violent offenders are reimprisoned for criminal violations. In this article, we use these findings to consider ways that mass incarceration is driven by both top‐down policies as well as bottom‐up organizational and community forces.
IMMIGRATION AND CRIME IN AN ERA OF TRANSFORMATION: A LONGITUDINAL ANALYSIS OF HOMICIDES IN SAN DIEGO NEIGHBORHOODS, 1980–2000*
Authors: MARTINEZ RAMIRO , STOWELL JACOB I. , LEE MATTHEW T.
Published: August 2010

Emerging research associated with the “immigration revitalization” perspective suggests that immigration has been labeled inaccurately as a cause of crime in contemporary society. In fact, crime seems to be unexpectedly low in many communities that exhibit high levels of the following classic indicators of social disorganization: residential instability, ethnic heterogeneity, and immigration. But virtually all research conducted to date has been cross‐sectional in nature and therefore unable to demonstrate how the relationship between immigration and crime might covary over time. This limitation is significant, especially because current versions of social disorganization theory posit a dynamic relationship between structural factors and crime that unfolds over time. The current study addresses this issue by exploring the effects of immigration on neighborhood‐level homicide trends in the city of San Diego, California, using a combination of racially/ethnically disaggregated homicide victim data and community structural indicators collected for three decennial census periods. Consistent with the revitalization thesis, results show that the increased size of the foreign‐born population reduces lethal violence over time. Specifically, we find that neighborhoods with a larger share of immigrants have fewer total, non‐Latino White, and Latino homicide victims. More broadly, our findings suggest that social disorganization in heavily immigrant cities might be largely a function of economic deprivation rather than forms of “neighborhood” or “system” stability.
THE REPRODUCTION OF RACIAL INEQUALITY: HOW CRIME AFFECTS HOUSING TURNOVER*
Authors: XIE MIN , MCDOWALL DAVID
Published: August 2010

This study examines the microlevel process of housing turnover between Blacks and Whites to assess whether crime plays an important role in the racial transition of neighborhoods. The study uses a unique, longitudinal version of the National Crime Survey in which each dwelling's close neighbors are identified. After controlling for household characteristics and the characteristics of their close neighbors, crime occurring in nearby areas is found to increase the chances of White‐to‐Black turnover while decreasing the chances of Black‐to‐White turnover. This change occurs even though the directly victimized houses do not necessarily have a probability of racial turnover different than that of other houses nearby. The findings suggest the presence of structural constraints that limit the housing opportunities for Blacks and constrain their choice of residence to comparatively unsafe neighborhoods. They also indicate that “White avoidance,” in which Whites systematically bypass high‐crime neighborhoods, is important in maintaining the relationship between race and crime.
AN EXAMINATION OF THE CALCIUM AND PHOSPHORUS NUTRITION OF THOROUGHBRED RACEHORSES
Authors: Caple I. W. , Bourke J. M. , Ellis P. G.
Published: August 2010

SUMMARY The calcium and phosphorus nutrition of thoroughbred racehorses was assessed by analysis of serum and urine samples collected from 90 horses in 1975 and 139 horses in 1980–81 at racetracks in Melbourne. Horses that were excreting greater than 15 μmole Ca/mosmole and which had a calcium to creatinine clearance ratio greater than 2.5% were considered to have adequate Ca intake. Horses that were excreting greater than 15 μmole P/mosmole and which had a phosphorus to creatinine clearance ratio greater than 4% were considered to have excessive phosphorus intake.

Sixty‐percent of the horses sampled had adequate Ca intake, and 44% had excessive intakes of P. Twenty‐five percent of the horses were excreting more P in urine than Ca. This would indicate these horses were subjected to nutritional secondary hyperparathyroidism, and horses entered in races by 53 of 99 trainers were in this category.

It may be concluded that a high proportion (40%) of thoroughbred racehorses receive inadequate calcium nutrition while they are fed high‐grain diets during racing.
DIELDRIN POISONING AND BOTULISM IN AUSTRALIAN PELICANS (PELECANUS CONSPICILLATUS)
Authors: McKenzie R. A. , Freudigmann C. L. , Mawhinney H. , Eaves L. E. , Green P. E. , Rees G. J.
Published: August 2010

SUMMARY Autopsies and laboratory examinations of material from 24 Australian pelicans found sick or dead in southern coastal Queensland in 1977 to 1979 revealed dieldrin poisoning in 8 from the Brisbane region and botulism in 8 from Brisbane. Bundaberg and Gladstone. In those diagnosed as dieldrin poisoning, brain and liver samples contained 12.1 to 27.4 and 34.0 to 48.1 mg/kg dieldrin respectively. All of these birds were emaciated, 2 had convulsed and 1 had muscle tremors. Low and probably insignificant residues of DDE were detected in many birds. Type C botulism was confirmed in 4 of the 6 birds tested with specific antiserums. A large number of parasites including mites, lice, nematodes, cestodes, trematodes, coccidia and Sarcocystis sp were found but were thought to have had only a limited effect on the health of these birds.
FUNCTIONING ADRENOCORTICAL TUMOUR IN A DOG
Authors: Vince M. E. , Watson A. D. J.
Published: August 2010

SUMMARYNaturally‐occurring hyperadrenocorticism was diagnosed in an 11‐year‐old female Dachshund with signs of polydipsia, polyuria, pendulous abdomen, weakness, depression and lethargy, and laboratory test abnormalities comprising lymphocytopaenia, eosinopaenia, hypercholesterolaemia and increased plasma alkaline phosphatase concentration. While awaiting hormonal test results, an adrenocorticolytic drug (o,p'‐DDD) was administered for 14 days, during which the patient deteriorated. Hormonal assays suggested a functioning adrenocortical tumour, but the poor condition of the patient precluded adrenalectomy. An adrenocortical carcinoma with hepatic metastases was found at necropsy.
Control of α‐mannosidosis in Angus cattle
Authors: HEALY P. J. , BABIDGE P. J. , EMBURY D. H. , HARRISON M. A. , JUDSON G. J. , MASON R. W. , PETTERSON D. S. , SINCLAIR A. J.
Published: August 2010

SUMMARY Tests for the detection of animals heterozygous for a‐mannosidosis were undertaken on samples taken from 34,203 cattle registered with the Angus Society of Australia. Results indicates 1,836 (5.4%) of the animals were heterozygotes. Heterozygotes were detected in 214 (51%) of the herds examined.
Pathology in the ovine foetus caused by an ovine pestivirus
Authors: PLANT J. W. , WALKER K. H. , ACLAND H. M. , GARD G. P.
Published: August 2010

SUMMARY Homogenised tissues or tissue culture supernatant fluid containing a non‐cytopathic pestivirus obtained from a lamb with a neurologic form of border disease, were inoculated into ewes at different stages of pregnancy.

Foetal death occurred in 9 ewes of those inoculated between 19 and 47 days of pregnancy while 3 ewes did not lamb. Eight of the foetuses were aborted between 77 and 132 days of pregnancy; of these 6 were autolysed or mummified and one had arthrogryposis. The one full‐term dead lamb had a hairy birth coat and lissencephalic micrencephaly.

Foetal death occurred in only 7 of 14 ewes inoculated between 57 and 72 days of pregnancy. Four of these ewes aborted between 77 and 108 days of pregnancy and 3 gave birth to full‐term, dead, hairy lambs. The remaining 7 ewes gave birth to live hairy lambs with severe inco‐ordination.

All lambs carried to term and aborted foetuses or lambs that could be examined had a range of intracranial malformations including focal leucomalacia, micrencephaly, hydranencephaly, porencephaly, lissencephaiy and cerebellar hypoplasia. Some lambs also had skeletal abnormalities including arthrogryposis, scoliosis and brachygnathia inferior.

The pestivirus isolate used in these trials produced more severe effects on the ovine foetus than previously observed in similar inoculation trials using pestivirus isolates from border disease lambs without nervous signs.
Seasonal variation in anthelmintic response by cattle to dermally applied levamisole
Authors: FORSYTH B. A. , GIBBON A. J. , PRYOR D. E.
Published: August 2010

SUMMARY Four experiments in 1978–79, and 2 in 1982 designed to define the optimum dose rate of dermally applied formulations of levamisole are described. These experiments showed that the absorption of levamisole with resultant blood levels and anthelmintic activity is strongly influenced by temperature. In warm to hot conditions percutaneous absorption is rapid and high blood levels with high anthelmintic activity against Haemonchus placet, Ostertagi sp, Trichostrongylus sp, Cooperia sp, Oesophagostomum radiatum, O. venulosum and Dictyocaulus viviparus result from dose rates of 10 mg/kg or more. In cold weather the high efficacy against H. placet, Cooperia sp, and Oesophagostomum sp is unchanged, but efficacy against Ostertagia sp, T. axei and D. viviparus decreases to the extent that a mean dose rate of 20 mg/kg (range 15 to 25 mg/kg) is necessary if the anthelmintic activity of dermally applied levamisole is to match that of either parenterally or orally administered material. These anthelmintic data are supported by the levamisole blood profile which in winter months, peaks at a figure of one quarter or less of that obtained from a similar dose rate in warm conditions. The implications of this variability in action are discussed.
Evaluation of a gel diffusion precipitin test for porcine parvovirus
Authors: TOO H. L. , SEAMAN J. T. , LITTLEJOHNS I. R. , LOVE R. J.
Published: August 2010

SUMMARYThe use of a gel diffusion precipitin (GDP) test for the detection of porcine parvovirus (PPV) infection in pigs is described. The close correlation between gel diffusion precipitin and haemagglutination inhibiting (HI) antibody titres indicates that, with careful standardisation, a high level of sensitivity can be achieved with the GDP test and that it is a simple and relatively inexpensive alternative to the more commonly used HI test.

Experimental infection of 2 groups of pigs showed that GDP and HI antibody responses were closely correlated and that GDP antibodies to PPV persisted for at least 41 weeks after infection.

In a commercial herd study, serological evidence of declining passive immunity and subsequent acquisition of active immunity was demonstrated by measuring the GDP and HI antibody titres in sequential serum samples of pigs from a known PPV endemic farm.

The GDP test described was shown to be less sensitive than haemagglutination (HA) in the detection of viral antigen but was, nevertheless, considered useful as a simple screening test for the amounts of antigen usually present in PPV infected mummified foetuses.
Vaccination of cattle against brucellosis using either a reduced dose of strain 19 or one or two doses of 45/20 vaccine
Authors: ALTON G. G. , CORNER L. A. , PLACKETT P.
Published: August 2010

SUMMARY Three groups, each of 14 mature Jersey heifers, were vaccinated. They were mated about 2 months later and those that became pregnant were challenged at about 6.5 months of pregnancy by the conjunctival application of virulent Brucella abortus.

Group 1 heifers received 2 doses of B. abortus 45/20 vaccine 2 months apart. Only 5 of the 14 heifers became pregnant, and of these 5 only one resisted challenge. Group 2 heifers received only one dose of 45/20 vaccine, 5 of the 10 challenged resisted infection. Group 3 heifers received 3 × 108 cfu of strain 19. Six of the 10 heifers challenged resisted infection. All of 5 non‐vaccinated control cattle became infected.

It appeared advantageous to give only one dose of 45/20 rather than 2 as presently recommended. A single dose of 45/20 vaccine induced resistance to virulent B. abortus approximately equal to that given by the reduced dose of strain 19. One dose of 45/20 vaccine stimulated transient serological positivity in 2 of 28 heifers whereas the reduced dose of strain 19 gave rise to persistent titres in 2 of 14 vaccinated heifers.
Immunisation of bulls against trichomoniasis
Authors: CLARK B. L. , DUFTY J. H. , PARSONSON I. M.
Published: August 2010

SUMMARY Studies into the immunisation of bulls against infection with Tritrichomonas foetus showed that subcutaneous administration of vaccines containing killed cells of T. foetus in a mineral oil adjuvant prevented the eliminted genital infection in most bulls up to the age of 5 years. Immunisation did not effectively prevent or cure infection in bulls older than 5.5 years.
Sampling ryegrass to assess the risk of annual ryegrass toxicity
Authors: McKAY ALAN C , RILEY IAN T
Published: August 2010

SUMMARY Most stock losses caused by annual ryegrass toxicity occur because stockowners unknowingly allow their stock to graze annual ryegrass (Lollum rigidum) Infected with the bacterium Clavlbacter toxicus. To help stockowners avoid losses we have developed criteria for a testing service to determine the risk of poisoning before the pasture is grazed. Low, medium and high risk categories were selected using samples of dry, mature ryegrass seedheads collected by stockowners from untreated, Infected pastures In South Australia. The proportion of toxic paddocks in each risk category over all the seasons tested was 11%;, 32%; and 76%;, respectively, and these accounted for 7%;, 14%; and 79%; of total stock losses. The proportion of paddocks in which stock were poisoned did not vary significantly between years, was not affected by variation in sample weight, and did not vary between South Australia and Western Australia.