bluuebunny/crossref_metadata_2025 huggingface dataset:
Computation of molecular vibrational frequencies using anomalous harmoniclike potentials
Authors: Li Xiangzhu , Paldus Josef
Published: July 2009

The instabilities of Hartree–Fock (HF) solutions at or near the equilibrium geometry of symmetric molecular species imply the existence of broken-symmetry solutions having a lower energy than the corresponding symmetry-adapted ones. Moreover, the distortion of the nuclear framework along the normal modes that are implied by such broken-symmetry solutions results in an anomalous or even singular behavior in the corresponding cuts of the potential energy surface (PES). Using such HF solutions as a reference, these anomalies propagate to a post-HF level and make it impossible to determine reliable harmonic or fundamental vibrational frequencies for such modes by relying on either numerical or analytical differentiation of the PES, requiring instead a numerical integration of the Schrödinger equation for the nuclear motion. This, in turn, requires a detailed knowledge on the PES in a wide range of geometries, necessitating a computation of the potential energy function in a large number of points. We present an alternative approach to this problem, referred to as the integral averaging method (IAM), which facilitates this task by significantly reducing the number of geometries for which one has to compute the potential energy while yielding results of practically the same accuracy as the solution of the Schrödinger equation. The IAM is applied to several ABA-type triatomics and to the allyl radical, whose asymmetric stretching mode potential suffers from an anomalous behavior due to the spin-preserving instabilities in restricted open-shell HF solutions.
Explicitly correlated combined coupled-cluster and perturbation methods
Authors: Shiozaki Toru , Valeev Edward F. , Hirata So
Published: July 2009

Coupled-cluster singles and doubles (CCSD) or coupled-cluster singles, doubles, and triples (CCSDT) with noniterative, perturbation corrections for higher-order excitations have been extended to include the basis functions that explicitly depend on interelectronic distances (r12) in the wave function expansions with the aim of dramatically accelerating the basis-set convergence of correlation energies. The extension has been based on the so-called R12 (or F12) scheme and applied to a second-order triples correction to CCSD [CCSD(2)T-R12], a second-order triples and quadruples correction to CCSD [CCSD(2)TQ-R12], a third-order triples correction to CCSD [CCSD(3)T-R12], and a second-order quadruples correction to CCSDT [CCSDT(2)Q-R12]. A simplified R12 treatment suggested by Fliegl et al. [J. Chem. Phys. 122, 084107 (2005)] has been combined with some of these methods, introducing CCSD(2)T(R12) and CCSD(2)TQ(R12). The CCSD(T)-R12 method has also been developed as an approximation to CCSD(2)T-R12. These methods have been applied to dissociation of hydrogen fluoride and double dissociation of water. For the molecules at their equilibrium geometries, molecular properties predicted by these methods converge extremely rapidly toward the complete-correlation, complete-basis-set limits with respect to the cluster excitation rank, perturbation order, and basis-set size. Although the R12 scheme employed in this work does not improve the basis-set convergence of connected triples or quadruples corrections, the basis-set truncation errors in these contributions have roughly the same magnitude as small residual basis-set truncation errors in the connected singles and doubles contributions even in the dissociation of hydrogen fluoride. In the double dissociation of water, the basis-set truncation errors in the connected triples contribution can be a few times as great as those in the connected singles and doubles contributions.
Characterisation of the melanocortin-1 receptor gene in alpaca and identification of possible markers associated with phenotypic variations in colour
Authors: Feeley N. L. , Munyard K. A.
Published: July 2009

The aim of this study was to determine if any correlation exists between melanocortin-1 receptor (MC1R) polymorphisms and skin and fibre colour in alpacas. Primers capable of amplifying the entire alpaca MC1R gene were designed from a comparative alignment of Bos taurus and Mus musculus MC1R gene sequences. The complete MC1R gene of 41 alpacas exhibiting a range of fibre colours, and which were sourced from farms across Australia, was sequenced from PCR products. Twenty-one single nucleotide polymorphisms were identified within MC1R. Two of these polymorphisms (A82G and C901T) have the potential to reduce eumelanin production by disrupting the activity of MC1R. No agreement was observed between fibre colour alone and MC1R genotype in the 41 animals in this study. However, when the animals were assigned to groups based on the presence or absence of eumelanin in their fibre and skin, only animals that had at least one allele with the A82/C901 combination expressed eumelanin. We propose that A82/C901 is the wild-type dominant ‘E’ MC1R allele, while alpacas with either G82/T901 or G82/Y901 are homozygous for the recessive ‘e’ MC1R allele and are therefore unable to produce eumelanin.
Influence of particle size and microbial phytase supplementation on the performance, nutrient utilisation and digestive tract parameters of broiler starters
Authors: Amerah A. M. , Ravindran V.
Published: July 2009

The aim of the present experiment was to examine the interaction between particle size and microbial phytase supplementation on the performance, nutrient utilisation and digestive tract development of broiler starters fed maize-based diets. The experimental design was a 2 × 2 factorial arrangement of treatments evaluating two maize particle sizes (medium and coarse) and two levels of phytase supplementation (without or with 500 phytase units/kg diet). The two particle sizes were achieved by grinding the whole maize in a hammer mill to pass through 3- and 7-mm screens, respectively. Broiler starter diets, based on maize and soybean meal, were formulated to meet recommended requirements for major nutrients, except phosphorus. Each of the four diets was fed ad libitum to six pens of eight male broilers each, from day 1 to day 21 post-hatching. Phytase supplementation increased (P < 0.001) the feed intake and weight gain, and lowered (P < 0.05) feed per gain in both medium and coarse particle size diets. Coarse grinding improved (P < 0.05) weight gain, but had no effect (P > 0.05) on feed intake and feed per gain. No interactions (P > 0.05) between phytase supplementation and particle size were observed for any of the performance parameters. Phytase supplementation increased (P < 0.001) ileal phosphorus digestibility and toe ash content of birds fed the medium particle size diet, but had no effect in those fed the coarse particle size diet. Apparent metabolisable energy and ileal digestibility of calcium and nitrogen were not influenced by particle size or phytase supplementation. The present findings suggest that the effectiveness of supplemental phytase on broiler performance is not influenced by the particle size of maize.
Behavioural changes at weaning in 6-month-old beef calves reared by cows of high or low milk yield
Authors: Ungerfeld R. , Quintans G. , Enríquez D. H. , Hrötzel M. J.
Published: July 2009

The objective of this experiment was to determine the differences in behavioural changes observed in 6-month-old beef calves at weaning in relation to milk yield availability from their dams. Eighteen Hereford or Hereford × Angus crossbred primiparous cows from a single herd remained with their calves suckling until the beginning of the experiment (194.1 ± 1.9 days after calving). On day 0, calves were moved to a 100-m2 corral far from their mothers, which were taken to a field more than 1000 m away, and returned to the original paddock on day 1. Milk production was determined monthly during the lactation period in 14 of the 18 cows. Calves’ behaviour was recorded using instantaneous sampling of individual animals in each group every 10 min from 0800 to 0950, 1200 to 1350, and 1600 to 1750 hours. Recordings were performed from day –3 to day 5, except on day 0. The calves from the five cows with higher milk yield (HMY) and the calves from the five cows with lower milk yield (LMY) were considered for data analysis. Milk yield was greater in HMY than LMY cows throughout all the lactation. HMY calves tended to suckle more frequently than LMY calves. There were no differences in average daily gain after weaning between HMY and LMY calves. However, HMY calves were heavier at weaning than LMY calves. The frequency of grazing, ruminating, walking and standing differed between HMY and LMY calves, and was affected by weaning. For example, calves from HMY cows spent less time grazing before and after weaning than calves from LMY cows. There were also interactions between group and time on the frequency of these behaviours. Overall, we conclude that the behaviour of 6-month-old beef calves at weaning differed according to their mothers’ milk yield, and their developmental growth stage.
A preliminary survey of zearalenone and other mycotoxins in Australian silage and pasture
Authors: Reed K. F. M. , Moore D. D.
Published: July 2009

The oestrogenic mycotoxin zearalenone can occur in pasture and fodder infected with various Fusarium spp., and at concentrations exceeding 1 mg/kg, it has been associated with a reduction in the fertility of grazing ruminants. Pasture and fodder samples collected in four small studies from cattle and sheep farms in south-eastern Australia were tested for zearalenone and other mycotoxins using high performance liquid chromatography. Zearalenone in winter pasture was detected (viz. >0.1 and up to 5.0 mg/kg DM) in 8 of 22 pastures; three exceeded the tolerance concentration, 1.0 mg/kg. Zearalenone was detected in 15 of 24 samples of silage that were submitted by farmers for nutritional assessment, but that were not suspected of toxicity; 12 were in the range 1.0–80 mg/kg. Zearalenone was correlated with crude protein concentration (r = 0.59, P < 0.05); it was high in legume-dominant compared with grass-dominant silage (P < 0.04). In a separate investigation of 28 feed samples submitted for mycotoxin screening by nutritionists/veterinarians, zearalenone was detected in 7 of 13 pastures, in two of two hays and 9 of 13 silages (6 of 28 exceeded 1 mg/kg). Deoxynivalenol was detected in 6 of 13 pastures, one of two hays and 10 of 13 silages. Deoxynivalenol was high (0.64–1.76 mg/kg) in five silages of excellent/average appearance. Ergovaline and lolitrem B were detected at above tolerable concentrations in four of eight perennial ryegrass-dominant samples examined. Aflatoxins, ochratoxin A and fumonisins were detected in some samples although the concentrations were low. Two samples contained either zearalenone and ergovaline, or zearalenone and deoxynivalenol, where both mycotoxins exceeded tolerable concentrations.
Survival of the rumen bacterium Synergistes jonesii in a herd of Droughtmaster cattle in north Queensland
Authors: Jones R. J. , Coates D. B. , Palmer B.
Published: July 2009

Droughtmaster steers from the CSIRO Research Station at Lansdown, 50 km south of Townsville, Queensland, were assessed at slaughter for indications of leucaena toxicity and the presence of the 3,4 dihydroxypyridine (DHP)-degrading bacterium Synergistes jonesii. This bacterium had been introduced to the herd 25 years earlier. Absence of clinical signs of ulceration of the oesophagus, absence of DHP in the urine, the presence of normal thyroid glands and the ability of rumen fluid to degrade high levels of mimosine from leucaena shoot tips in vitro all confirmed that these steers had an active bacterial culture capable of degrading mimosine and its degradation products 3,4 and 2,3 DHP. Steers had been away from the Research Station and away from leucaena pastures for long periods but had clearly not lost the bacteria or if they had, they had regained them on return to leucaena pastures on Lansdown. It is postulated that the bacteria may spread via the faeces in cattle yards and remain in the rumen for long periods, even at low levels, in the absence of leucaena in the diet. Reasons other than the effectiveness of the bacterium should be explored to explain the failure of cattle in some Queensland herds to fully degrade 3,4 and 2,3 DHP.
Global warming benefits the small in aquatic ecosystems
Authors: Daufresne Martin , Lengfellner Kathrin , Sommer Ulrich
Published: July 2009

Understanding the ecological impacts of climate change is a crucial challenge of the twenty-first century. There is a clear lack of general rules regarding the impacts of global warming on biota. Here, we present a metaanalysis of the effect of climate change on body size of ectothermic aquatic organisms (bacteria, phyto- and zooplankton, and fish) from the community to the individual level. Using long-term surveys, experimental data and published results, we show a significant increase in the proportion of small-sized species and young age classes and a decrease in size-at-age. These results are in accordance with the ecological rules dealing with the temperature–size relationships (i.e., Bergmann's rule, James' rule and Temperature–Size Rule). Our study provides evidence that reduced body size is the third universal ecological response to global warming in aquatic systems besides the shift of species ranges toward higher altitudes and latitudes and the seasonal shifts in life cycle events.
Rapid detection and profiling of cancer cells in fine-needle aspirates
Authors: Lee Hakho , Yoon Tae-Jong , Figueiredo Jose-Luiz , Swirski Filip K. , Weissleder Ralph
Published: July 2009

There is a growing need for fast, highly sensitive and quantitative technologies to detect and profile unaltered cells in biological samples. Technologies in current clinical use are often time consuming, expensive, or require considerable sample sizes. Here, we report a diagnostic magnetic resonance (DMR) sensor that combines a miniaturized NMR probe with targeted magnetic nanoparticles for detection and molecular profiling of cancer cells. The sensor measures the transverse relaxation rate of water molecules in biological samples in which target cells of interest are labeled with magnetic nanoparticles. We achieved remarkable sensitivity improvements over our prior DMR prototypes by synthesizing new nanoparticles with higher transverse relaxivity and by optimizing assay protocols. We detected as few as 2 cancer cells in 1-μL sample volumes of unprocessed fine-needle aspirates of tumors and profiled the expression of several cellular markers in <15 min.
Chlorine activation indoors and outdoors via surface-mediated reactions of nitrogen oxides with hydrogen chloride
Authors: Raff Jonathan D. , Njegic Bosiljka , Chang Wayne L. , Gordon Mark S. , Dabdub Donald , Gerber R. Benny , Finlayson-Pitts Barbara J.
Published: July 2009

Gaseous HCl generated from a variety of sources is ubiquitous in both outdoor and indoor air. Oxides of nitrogen (NOy) are also globally distributed, because NO formed in combustion processes is oxidized to NO2, HNO3, N2O5and a variety of other nitrogen oxides during transport. Deposition of HCl and NOyonto surfaces is commonly regarded as providing permanent removal mechanisms. However, we show here a new surface-mediated coupling of nitrogen oxide and halogen activation cycles in which uptake of gaseous NO2or N2O5on solid substrates generates adsorbed intermediates that react with HCl to generate gaseous nitrosyl chloride (ClNO) and nitryl chloride (ClNO2), respectively. These are potentially harmful gases that photolyze to form highly reactive chlorine atoms. The reactions are shown both experimentally and theoretically to be enhanced by water, a surprising result given the availability of competing hydrolysis reaction pathways. Airshed modeling incorporating HCl generated from sea salt shows that in coastal urban regions, this heterogeneous chemistry increases surface-level ozone, a criteria air pollutant, greenhouse gas and source of atmospheric oxidants. In addition, it may contribute to recently measured high levels of ClNO2in the polluted coastal marine boundary layer. This work also suggests the potential for chlorine atom chemistry to occur indoors where significant concentrations of oxides of nitrogen and HCl coexist.
Obstetric outcome in women with hepatitis C virus infection and thyroid dysfunction
Authors: KUMAR ASHOK , AGARWAL KRISHNA , GUPTA RAM KUMAR , KAR PREMASHISH
Published: July 2009

Objectives. To determine the incidence of thyroid abnormality in pregnant women with hepatitis C virus (HCV) infection and evaluate pregnancy outcomes with respect to thyroid function status. Design. Prospective cohort study. Setting. Tertiary care hospital. Population. Pregnant women with HCV infection. Methods. Seventy‐eight HCV positive women had radioimmunoassay thyroid function tests. All were followed until delivery. Pregnancy outcomes were compared in women with and without subclinical hypothyroidism. Main outcome measures. Maternal and perinatal outcomes. Results. Of 78 anti‐HCV antibody positive pregnant women, 13 (16.7%) had abnormal thyroid‐stimulating hormone (TSH) (>5 mIU/L; hypothyroid group) and the remaining 65 (83.3%) had normal TSH values (euthyroid group). None had abnormal free T4 levels. None showed evidence of fetal distress in labor or fetal asphyxia. In the hypothyroid group, 23% compared to 6.2% in euthyroid group underwent cesarean section (p = 0.07). The incidence of preterm delivery (7.7% vs. 24.6%; p = 0.28), mean gestation at delivery (38.2±1.8 vs. 37.5±1.8 weeks, p = 0.19), and birthweight (2,687±430 g vs. 2,846±379 g, p = 0.18) was comparable. Neonatal nursery admissions were comparable. Conclusion. The presence of subclinical hypothyroidism in pregnant women with HCV infection does not adversely affect short‐term pregnancy outcomes.
Diffusion-weighted magnetic resonance imaging in cervical lymphadenopathy: report of three cases of patients with bartonella henselae infection mimicking malignant disease
Authors: Muenzel D. , Duetsch S. , Fauser C. , Slotta-Huspenina J. , Gaa J. , Rummeny E. J. , Holzapfel K.
Published: July 2009

Diffusion-weighted MR imaging is a potential technique for differentiation between benign and malignant lymph nodes. However, lympadenopathy caused by Bartonella henselae infection showes low ADC values in diffusion weighted MRI as typically seen in malignant disease.
Book Reviews
Authors: Svendsmark Rolf
Published: July 2009

The Physics of Clinical MR Taught through Images, second edition. Edited by V. M. Runge, W. R. Nitz, & S. H. Schmeets. Stuttgart/New York: Thieme Medical Publishers, Inc., 2009. ISBN: 978-1-60406-161-1. 232 pages. Price (paperback): USD 44.95, EUR 49.95
Network News Coverage of Avian Flu: Identifying the Characteristics of Risk
Authors: Duhé Sonya Forte , Cho Sooyoung
Published: July 2009

This study is the first of its kind examining network TV news coverage of avian flu over the past decade. It is the only study to date analyzing sources of avian flu media coverage and analyzing the stories for risk characteristics. Researchers found that prevention/preparedness effort was the most frequent frame type. Scientists/MDs were the most frequently quoted sources. A significant proportion of stories regarded the flu as a catastrophic, dreadful, and fatal risk.
HIV uses autophagy for its own means
Authors: LeBrasseur Nicole
Published: July 2009

Virus avoids degradation and turns pathway into a helping hand for virion production.
Matt Gibson: The blueprints of tissue architecture
Authors: Short Ben
Published: July 2009

Gibson studies the genetic and physical processes that help epithelia get in shape.
Lysophosphatidic acid acyltransferase 3 regulates Golgi complex structure and function
Authors: Schmidt John A. , Brown William J.
Published: July 2009

Recent studies have suggested that the functional organization of the Golgi complex is dependent on phospholipid remodeling enzymes. Here, we report the identification of an integral membrane lysophosphatidic acid–specific acyltransferase, LPAAT3, which regulates Golgi membrane tubule formation, trafficking, and structure by altering phospholipids and lysophospholipids. Overexpression of LPAAT3 significantly inhibited the formation of Golgi membrane tubules in vivo and in vitro. Anterograde and retrograde protein trafficking was slower in cells overexpressing LPAAT3 and accelerated in cells with reduced expression (by siRNA). Golgi morphology was also dependent on LPAAT3 because its knockdown caused the Golgi to become fragmented. These data are the first to show a direct role for a specific phospholipid acyltransferase in regulating membrane trafficking and organelle structure.
SUMOylation of nuclear actin
Authors: Hofmann Wilma A. , Arduini Alessandro , Nicol Samantha M. , Camacho Carlos J. , Lessard James L. , Fuller-Pace Frances V. , de Lanerolle Primal
Published: July 2009

Actin, a major component of the cytoplasm, is also abundant in the nucleus. Nuclear actin is involved in a variety of nuclear processes including transcription, chromatin remodeling, and intranuclear transport. Nevertheless, the regulation of nuclear actin by posttranslational modifications has not been investigated. We now show that nuclear actin is modified by SUMO2 and SUMO3 and that computational modeling and site-directed mutagenesis identified K68 and K284 as critical sites for SUMOylating actin. We also present a model for the actin–SUMO complex and show that SUMOylation is required for the nuclear localization of actin.
The Cirque du Soleil of Golgi membrane dynamics
Authors: Bankaitis Vytas A.
Published: July 2009

The role of lipid metabolic enzymes in Golgi membrane remodeling is a subject of intense interest. Now, in this issue, Schmidt and Brown (2009. J. Cell Biol. doi:10.1083/jcb.200904147) report that lysophosphatidic acid–specific acyltransferase, LPAAT3, contributes to Golgi membrane dynamics by suppressing tubule formation.
The principal neurons of the medial nucleus of the trapezoid body and NG2+ glial cells receive coordinated excitatory synaptic input
Authors: Müller Jochen , Reyes-Haro Daniel , Pivneva Tatjyana , Nolte Christiane , Schaette Roland , Lübke Joachim , Kettenmann Helmut
Published: July 2009

Glial cell processes are part of the synaptic structure and sense spillover of transmitter, while some glial cells can even receive direct synaptic input. Here, we report that a defined type of glial cell in the medial nucleus of the trapezoid body (MNTB) receives excitatory glutamatergic synaptic input from the calyx of Held (CoH). This giant glutamatergic terminal forms an axosomatic synapse with a single principal neuron located in the MNTB. The NG2 glia, as postsynaptic principal neurons, establish synapse-like structures with the CoH terminal. In contrast to the principal neurons, which are known to receive excitatory as well as inhibitory inputs, the NG2 glia receive mostly, if not exclusively, α-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid receptor–mediated evoked and spontaneous synaptic input. Simultaneous recordings from neurons and NG2 glia indicate that they partially receive synchronized spontaneous input. This shows that an NG2+ glial cell and a postsynaptic neuron share presynaptic terminals.
Mutations reveal voltage gating of CNGA1 channels in saturating cGMP
Authors: Martínez-François Juan Ramón , Xu Yanping , Lu Zhe
Published: July 2009

Activity of cyclic nucleotide–gated (CNG) cation channels underlies signal transduction in vertebrate visual receptors. These highly specialized receptor channels open when they bind cyclic GMP (cGMP). Here, we find that certain mutations restricted to the region around the ion selectivity filter render the channels essentially fully voltage gated, in such a manner that the channels remain mostly closed at physiological voltages, even in the presence of saturating concentrations of cGMP. This voltage-dependent gating resembles the selectivity filter-based mechanism seen in KcsA K+ channels, not the S4-based mechanism of voltage-gated K+ channels. Mutations that render CNG channels gated by voltage loosen the attachment of the selectivity filter to its surrounding structure, thereby shifting the channel's gating equilibrium toward closed conformations. Significant pore opening in mutant channels occurs only when positive voltages drive the pore from a low-probability open conformation toward a second open conformation to increase the channels' open probability. Thus, the structure surrounding the selectivity filter has evolved to (nearly completely) suppress the expression of inherent voltage-dependent gating of CNGA1, ensuring that the binding of cGMP by itself suffices to open the channels at physiological voltages.
The dual nest for degenerate Yoccoz puzzles
Authors: Aspenberg Magnus
Published: July 2009

The Yoccoz puzzle is a fundamental tool in Holomorphic Dynamics. The original combinatorial argument by Yoccoz, based on the Branner-Hubbard tableau, counts the preimages of a non-degenerate annulus in the puzzle. However, in some important new applications of the puzzle (notably, matings of quadratic polynomials) there is no non-degenerate annulus. We develop a general combinatorial argument to handle this situation. It allows us to derive corollaries, such as the local connectedness of the Julia set, for suitable families of rational maps.
Liver size reveals social status in the African cichlid Neolamprologus pulcher
Authors: Sopinka N.M. , Fitzpatrick J.L. , Desjardins J.K. , Stiver K.A. , Marsh‐Rollo S.E. , Balshine S.
Published: July 2009

Wild groups (n = 167) of the cooperatively breeding Lake Tanganyika cichlid, Neolamprologus pulcher, were used to investigate how social status and sex influence liver investment. In contrast to expectations, males and females (controlling for body size) had similar liver investment and subordinates (both sexes) had relatively larger livers compared with dominants. Three hypotheses were considered for why social status results in liver size disparity: liver mass might reflect status‐dependent differences in (1) energy expenditure, (2) energy storage and (3) energy acquisition. First, dominants performed more energetically costly behaviours (e.g. social policing and care) compared with subordinates, supporting the notion that energy expenditure drives liver investment. Moreover, dominants in large groups (with many subordinates to monitor) and those holding multiple territories (with large areas to patrol), tended to have smaller livers. Second, subordinates did not appear to use the liver as a strategic energy storage organ. In laboratory and field experiments, subordinates ascending in rank had similar or larger livers during periods of rapid growth compared with non‐ascending controls. Third, although subordinates fed more frequently than dominants, a negative relationship was found between feeding rates and liver size. Hence, these results contrast with previous liver studies and suggest that liver investment patterns were linked to status‐driven differences in energy expenditure but not to energy intake or storage in N. pulcher.
Embryonic staging series for the beach spawning, terrestrially incubating California grunion Leuresthes tenuiswith comparisons to other Atherinomorpha
Authors: Martin K.L. , Moravek C.L. , Flannery J.A.
Published: July 2009

California grunion Leuresthes tenuis synchronize spawning with tidal cycles, so the embryos incubate in a terrestrial environment, delay hatching until cued by a specific environmental trigger, and may extend incubation for up to an additional four weeks. These adaptations, however, do not appear to alter the morphology or sequence of early developmental stages as compared to other Atherinomorph fishes in the Orders Beloniformes and Cyprinodontiformes. Embryonic development is described in a series of 30 stages based on morphology observed by light microscopy. Stages are placed in five periods: zygote and cleavage, blastula, gastrula, segmentation and organogenesis, and hatching competence. Embryos from a southern population of L. tenuis in Los Angeles are compared with embryos found >560 km north in San Francisco Bay. Northern L. tenuis embryos developed more slowly at several stages than southern embryos and reached hatching competence later, but both locations maintained synchrony with the tidal cycle for both spawning and hatching. The variation in rates of development and stage at hatching readiness are forms of developmental heterochrony that may be associated with evolutionary adaptation or morphological plasticity within this highly successful clade.
Lunar and daily spawning rhythms of Senegal sole Solea senegalensis
Authors: Oliveira C. , Dinis M. T. , Soares F. , Cabrita E. , Pousão‐Ferreira P. , Sánchez‐Vázquez F. J.
Published: July 2009

A periodicity of 29 days was observed in spawning rhythms in Senegal sole Solea senegalensis, with an acrophase around the last quarter and the new moon. In both spring and autumn, a very marked nocturnal spawning rhythm was registered, with spawning beginning after dusk and the acrophase occurring around 2300 hours. When the photoperiod was artificially extended (from 10L:14D to 14L:10D), S. senegalensis synchronized to the new photoperiod: spawning took place after the new ‘dusk’, the beginning gradually shifting from 2100 to 2300 hours and the acrophase from 2325 to 0032 hours. Under continuous light conditions, fish sustained rhythmicity for 2 days, with an acrophase at 2249 hours, which suggested the existence of an endogenous pacemaker controlling the daily spawning rhythm. These findings provided new insights for better understanding the reproductive physiology of this species and for optimizing the timing protocols of egg collection and larvae production in S. senegalensis aquaculture.
Prey selection and functional response of juvenile lemon sharks Negaprion brevirostris
Authors: Reeve A. , Handy R.D. , Gruber S.H.
Published: July 2009

Prey preference of juvenile lemon sharks Negaprion brevirostris was examined in experiments conducted in field‐based pens where the fish were offered meals of live teleosts: grey snapper Lutjanus griseus and yellow fin majorra Gerres cinereus in ratios of L. griseus:G. cinereus varying from 10:0 to 2:8. Relative electivity indices for each treatment showed that N. brevirostris preyed on G. cinereus rather than L. griseus. They showed a prey preference relating to density of G. cinereus (type II functional response) but not to L. griseus.
The structure and possible functions of the milkfish Chanos chanos adipose eyelid
Authors: Chang C.‐H. , Chiao C.‐C. , Yan H. Y.
Published: July 2009

Basic histological sections (with different staining methods) and scanning electron microscopy (SEM) examinations showed that there were three distinctive layers in the adipose eyelid of milkfish Chanos chanos, which is found in the cephalie region and covers the entire eye. The outer and inner layers were epithelial tissues and the middle layer was composed of connective tissue formed by type I collagen fibrils. No adipose tissue was found in any of the three layers of the so‐called adipose eyelid. Examination by transmission spectrophotometer showed that the adipose tissue could filter out ambient light with a wavelength shorter than 305 nm. A photoretinoscope was used to investigate whether the adipose eyelid influenced the mechanism of eye focusing. Eye diopter values did not differ before or after eyelid removal, which indicated that the adipose eyelid did not play a role in eye focusing. In light of these findings, it is suggested that the adipose eyelid serves to block exposure of harmful ultraviolet light into eyes and may also to offer some protection against impact to the eye in the aquatic environment.
Modelling the growth of Japanese eelAnguilla japonicain the lower reach of the Kao‐Ping River, southern Taiwan: an information theory approach
Authors: Lin Y. J. , Tzeng W. N.
Published: July 2009

Information theory was applied to select the best model fitting total length (LT)‐at‐age data and calculate the averaged model for Japanese eelAnguilla japonicacompiled from published literature and the differences in growth between sexes were examined. Five candidate growth models were the von Bertalanffy, generalized von Bertalanffy, Gompertz, logistic and power models. The von Bertalanffy growth model with sex‐specific coefficients was best supported by the data and nearly overlapped the averaged growth model based on Akaike weights, indicating a similar fit to the data. The Gompertz, generalized von Bertalanffy and power growth models were also substantially supported by the data. TheLTat age ofA. japonicawere larger in females than in males according to the averaged growth mode, suggesting a sexual dimorphism in growth. Model inferences based on information theory, which deal with uncertainty in model selection and robust parameter estimates, are recommended for modelling the growth ofA. japonica.
Influence of the photoperiod on growth rate and insulin‐like growth factor‐I gene expression in Nile tilapia Oreochromis niloticus
Authors: Vera Cruz E. M. , Brown C. L.
Published: July 2009

The effects of the duration of the light phase photoperiod (8 h light or 16 h light) on the growth and hepatic insulin‐like growth factor‐I (IGF‐I) gene expression in Nile tilapia Oreochromis niloticus were evaluated. There was a slight but not significant tendency for fish in the long light phase group (LP) to display elevated specific growth rate (G) both in mass (M) and standard length (LS) compared with that in the short light phase group (SP;P = 0·057 for GM;P = 0·055 for GL). Significantly, higher food conversion efficiency was observed in the LP than in the SP. There were significant positive correlations between IGF‐I concentrations and G, both in M and LS. A significantly negative correlation was observed between IGF‐I mRNA level and eye colour pattern. The lack of significant differences in G and hepatic IGF‐I gene expression, despite the significant difference in feed conversion efficiency, may be related partly to the development of different levels of social interactions in the different groups within a photoperiod regime leading to increased variation of results within each group. These findings suggest that hepatic IGF‐I gene expression has potential utility as a growth rate indicator for this species of fish and social status, as quantified by eye colour pattern, appears to be a much stronger determinant of growth rate and IGF‐I transcript level than does light phase photoperiod length.
Melatonin concentrations during larval and postlarval development of gilthead sea bream Sparus auratus: more than a time‐keeping molecule?
Authors: Kalamarz H. , Nietrzeba M. , Fuentes J. , Martinez‐Rodriguez G. , Mancera J.M. , Kulczykowska E.
Published: July 2009

In this study, melatonin (MEL) and thyroxine (T4) concentrations were measured during larval and postlarval development of gilthead sea bream Sparus auratus Hormones were measured in whole bodies of larvae or the head and trunk of postlarvae after 67 days of exposure to constant light, 24L:0D, constant darkness, 0L:24D or 12L:12D and in the plasma of 6 month juveniles kept under the 12L:12D, 0L:24D and 24L:0D regimes. High MEL concentrations in larvae suggested a distinct role of MEL in early organogenesis and development of S. auratus. In larvae, the gastro‐intestinal tract seemed to be an important extrapineal and extraretinal source of MEL. No endogenous rhythm of MEL synthesis was demonstrated in 67 day larvae; however, in 6 month juveniles, it was evident. At early ontogenesis of S. auratus, the role of MEL is probably related mostly to the control of development and protection against free radicals, whereas its action as a time‐keeping molecule develops later. The increase in T4 concentration during the S. auratus larva–juvenile transition, i.e. between 50 and 70 days post‐hatch, which was observed concurrently with the decrease of MEL concentration, may suggest an inverse relationship between T4 and MEL.
Contrasting trends in two condition indices: bathymetric and spatial variation in autumn condition of Icelandic cod Gadus morhua
Authors: Pardoe H. , Marteinsdóttir G.
Published: July 2009

Bathymetric and regional variation in condition of Icelandic cod Gadus morhua in autumn is compared to that previously observed in spring. Once again, contradicting patterns in the hepato‐somatic index and a morphometric index of fish condition were observed. The relevance of this persistent spatial variation in condition in relation to emerging evidence of behavioural types is discussed.
Stock structure of blue threadfin Eleutheronema tetradactylum on the Queensland east coast, as determined by parasites and conventional tagging
Authors: Zischke M. T. , Cribb T. H. , Welch D. J. , Sawynok W. , Lester R. J. G.
Published: July 2009

Blue threadfin Eleutheronema tetradactylum (Polynemidae) were examined from four areas (Princess Charlotte Bay, Trinity Inlet, Halifax Bay and Upstart Bay) in eastern Queensland covering a distance of c. 950 km of coastline. Parasites were used as biological markers to infer stock structure of E. tetradactylum. Parasites designated as ‘temporary’ biological markers were the copepod Thysanote eleutheronemi, the acanthocephalan Neoechinorhynchus topseyi, the nematode Philometra rajani and hemiurid trematodes. The larval nematodes Anisakis sp. Type 1 and Terranova sp. Type 2; and the larval cestodes Pterobothrium pearsoni and Callitetrarhynchus gracilis were considered ‘permanent’ biological markers. Both univariate and multivariate analyses demonstrated that there was little difference in temporary parasite abundance between the four areas. In contrast, the same analyses revealed that most areas had two or more significant differences in permanent parasite abundance, with the exception of Halifax Bay and Upstart Bay, which were significantly different only in the multivariate analysis. Biological markers predicted that Princess Charlotte Bay and Trinity Inlet consisted of distinct populations, whereas Halifax Bay and Upstart Bay were not clearly differentiated. Tag recapture data supported this hypothesis; the majority of recaptures were within 100 km of the initial tagging location. Geographical movement of E. tetradactylum may be limited due to their biology and ecology, as well as the distances and oceanographic boundaries that separate habitats. Contrary to current management definitions, the stock structure of E. tetradactylum on the east coast of Queensland appears to be geographically differentiated at a small spatial scale.
Winter lipid depletion of juvenile walleye pollock Theragra chalcogramma in the Doto area, northern Japan
Authors: Kooka K. , Yamamura O. , Ohkubo N. , Honda S.
Published: July 2009

Seasonal variation in body size and nutritional condition of juvenile walleye pollock Theragra chalcogramma was examined to elucidate the mechanism underlying their first‐winter survival on the continental shelf of the Doto area, northern Japan, based on monthly samples collected over 2 years. Stored lipid mass was highest during autumn, but 93% (2004) and 80% (2005) of lipids were exhausted by the onset of winter. Lipid levels in the winter of 2004 remained low (7–14% of the autumnal maximum), and there was reduced growth rate until the spring, whereas in 2005 lipid levels were higher and more variable (10–46% of the maximum) and some growth occurred. An analysis of the allometric relationships between body size and stored energy showed that larger individuals accumulated disproportionately more energy in the autumn, but the advantage disappeared prior to the winter. In January 2004, stored lipid energy was low throughout the Doto continental shelf relative to the continental slope area. These results suggest that winter feeding opportunities on the shelf are severely limited but not completely absent. Previous studies have shown that winter temperatures on the shelf are lower than those in the slope area. It is possible that juvenile T. chalcogramma survive winter on the shelf without a high level of pre‐winter lipid storage because the occasional feeding in the cold shelf water benefits energy conservation.
Patterns of migration and residency in coastal cutthroat trout Oncorhynchus clarkii clarkii from two tributaries of the lower Columbia River
Authors: Zydlewski G.B. , Zydlewski J. , Johnson J.
Published: July 2009

Coastal cutthroat trout Onchorhynchus clarkii clarkii life‐history variants, migration and freshwater residency were monitored using stationary passive integrated transponder (PIT) tag arrays in two tributaries of the Columbia River from 2001 to 2005 (Abernathy Creek, river kilometre, rkm 76) and from 2002 to 2005 (Chinook River, rkm 6). In 2001–2003 and 2002–2003 (Abernathy and Chinook, respectively), 300–500 coastal O. c. clarkii were captured in each tributary by electrofishing and implanted with 23 mm PIT tags. PIT arrays monitored movements from the initiation of tagging through the spring of 2005. Rotary screw traps were also operated on both tributaries. In Abernathy Creek, 28% of tagged individuals were observed through either active capture or passive interrogation. Of these, 32% were identified as migrants and 68% were identified as residents. In the Chinook River, 48% of tagged fish were observed subsequent to tagging; 92% of these fish were migrants and only 8% were resident. In both tributaries, a greater proportion of resident fish were in the upper reaches. The majority of migrants (78–93%) moved the spring following tagging. Migrants leaving at age 2+ years tended to grow faster than those that migrated at age 3+ years or residents. Patterns of growth or growth opportunities may influence both patterns of life‐history expression and the timing of migration.
Reproductive characteristics and population decline of four species of skate (Rajidae) off the eastern coast of Canada
Authors: Mcphie R. P. , Campana S. E.
Published: July 2009

Four of the most common species of skate (Rajidae) were studied off eastern Canada to determine if their reproductive characteristics were linked to their population trajectories. The fecundity of the winter skate Leucoraja ocellata, the little skate Leucoraja erinacea, the thorny skate Amblyraja radiata and the smooth skate Malacoraja senta averaged between 41 and 56 egg cases per year for each species. For all species but L. ocellata, males matured at larger sizes and at later ages than females. Theoretical rates of population increase for non‐equilibrium populations of L. ocellata (c. 0·07), M. senta (c. 0·14) and L. erinacea and A. radiata (c. 0·20) were low compared to most fishes, indicating that north‐west Atlantic skates are intrinsically unproductive, yet are theoretically capable of supporting low‐level fisheries. Nevertheless, the results of 36 years of research surveys indicate that the abundance of mature L. ocellata, A. radiata and M. senta all decreased by >90% since 1970, indicating that past fishing mortality (both directed and undirected) has outstripped the net productivity of the skate populations on the eastern Scotian Shelf. The relationship between maximum age (tmax) and age of maturity (tmat) was a better predictor of population growth rate than was body size, with the species exhibiting the highest ratios of tmat :tmax (L. ocellata = 0·68, M. senta = 0·66) having the lowest predicted population growth rates. L. ocellata appears to have the lowest productivity and has experienced the greatest population decline, thus raising concerns over its future status.
Feeding guilds and food resource partitioning in a lake fish assemblage: an ontogenetic approach
Authors: Specziár A. , Rezsu E. T.
Published: July 2009

Ontogenetic diet patterns and trophic guild structure of a 15 species temperate lake fish assemblage were analysed over wide size intervals (up to seven orders of magnitude in body mass), representing practically the whole life span in most species. A two‐step objective clustering technique supplemented with other multivariate statistical tools proved that size‐related diet changes clearly played an important role in structuring trophic organization of fishes inhabiting Lake Balaton. As many as 13 out of the 15 fish species showed marked size‐related dietary changes with two to four ontogenetic feeding stages. At the assemblage level, 11 trophic guilds were separated. Guild membership was size‐dependent in 11 fish species that participated in two to four trophic guilds during their life span. The most complex trophic ontogeny was observed in roachRutilus rutilusand aspAspius aspiuswith four guild memberships. This study showed that trophic status of fishes may be very size‐sensitive and thus a universal classification of fish species to general trophic guilds, such as ‘planktivore’, ‘benthivore’, ‘piscivore’ or ‘herbivore’, should be applied very carefully even in environmental monitoring and fisheries management applications, unless it is supported by relevant results of life span diet analyses.
Geochemical constraints on the Palaeocene–Miocene evolution of eastern Azerbaijan, with implications for the South Caspian basin and eastern Paratethys
Authors: Johnson C. L. , Hudson S. M. , Rowe H. D. , Efendiyeva M. A.
Published: July 2009

Fine‐grained Palaeogene–early Neogene strata of the South Caspian basin, specifically the Oligocene–Lower Miocene Maikop Series, are responsible for the bulk of hydrocarbon generation in the region. Despite the magnitude of oil and gas currently attributed to the source interval offshore, geochemical evaluation of 376 outcrop samples from the northern edge of the Kura basin (onshore eastern Azerbaijan) indicates that depositional conditions in these proximal strata along the basin margins were dominantly oxic to mildly suboxic/anoxic throughout three major depositional stages: the Palaeocene–Eocene, Oligocene–early Middle Miocene and late Middle–Late Miocene. Palaeocene–Eocene samples have low average total organic carbon (TOC) values (0.3%), with higher total inorganic carbon (TIC) values (average=2.6%), extremely low sulphur content (0.2%) and relatively high detrital input as indicated by Fe/Al and Ti/Al ratios. C–S–Fe associations, along with relatively lower concentrations of redox‐sensitive trace elements (e.g. V, Ni, Mo, U) indicate dominantly oxic environments of deposition during much of the Palaeocene–Eocene. A pronounced geochemical shift occurred near the Eocene–Oligocene boundary, and continued through the Early Miocene. Specifically, this interval is characterized by a distinct increase in TOC (ranging from 0.1 to 6.3% with an average of 1.5%), C–S–Fe associations that reveal an abrupt relative increase of carbon and sulphur with respect to iron‐dominated Palaeocene–Eocene samples, and higher concentrations of redox‐sensitive trace metals. These changes suggest that a shift away from unrestricted marine conditions and towards more variable salinity conditions occurred coincident with the initial collision of the Arabian plate and partial closure of the Paratethys ocean. Despite periodic basin restriction, the majority of Upper Eocene–Lower Miocene strata in the northern Kura basin record oxic to slightly dysoxic conditions.