bluuebunny/crossref_metadata_2025 huggingface dataset:
Eragrostis curvula (Schrad.) Nees. complex pastures in southern New South Wales, Australia: impact of Eragrostis curvula, Medicago sativa L. and Phalaris aquatica L. pastures on soil water
Authors: Johnston W. H. , Cornish P. S.
Published: November 2005

Gypsum blocks were used to monitor soil water under 5 rotationally grazed pastures [Eragrostis curvula cvv. 4650, 4660 and Consol; Medicago sativa cv. Aurora and Phalaris aquatica (a 50/50 mixture of cvv. Uneta and Sirolan)] at depths of 15, 30, 60 and 120 cm at Wagga Wagga in southern NSW, Australia from 18 December 1993 to 23 November 1998.
At 120 cm depth, soil matric potential (ψ) varied from approximately –14 kPa in winter and spring, to less than –1500 kPa in autumn. During 2 droughts the soil remained drier than its water holding capacity limit, but when rainfall was average or above average, there was no evidence that deficits were maintained through winter. The nature of the rainfall (rainfall/day and numbers of consecutive wet days), which varies through the seasons, impacted markedly on ψ, with considerable short-term variation observed in response to isolated heavy rainfall events in summer and autumn.
Medicago sativa cv. Aurora generated lower ψ than E. curvula in mid- to late-spring; whereas except for 4650, which was not persistent at the site, E. curvula reduced ψ in early to mid-summer, and to generally more negative extremes than by M. sativa. There was no indication that the roots of P. aquatica did not extend to the same depths as the other pastures, but it seemed unable to dry the soil to the same extent. Summer-active weeds, which were prominent in the P. aquatica pasture in years of above average rainfall, reduced the deficit difference between it and the other pastures.
Gypsum block ψ was converted to volumetric soil water content (θv) using soil water retention curves and estimates of soil bulk density (ρb). Relative to P. aquatica, E. curvua Consol and M. sativa maintained a deficit of between 25 and 75 mm for most non-winter periods. There was no evidence that the deficit created by either pasture was consistently greater than the other.
There was considerable dynamism within the datasets for all the pastures, which was ascribed to the frequent occurrence of non-matrix flow, mainly in response to heavy rainfall events (>25 mm in <5 days) that occurred when the soil was dry in summer and autumn. In the long-term it was estimated that such events could be associated with up to 25% of the rainfall.
Inducing biochemical changes to simulate after-roast darkening in macadamia kernel
Authors: Albertson P. L. , De Giovanni C. , Cocksedge R. H. , Forrester R. I. , Rae A. L. , Mason R. , McConchie C. A.
Published: November 2005

After-roast darkening is a defect in macadamia kernel evident only upon roasting that adversely affects kernel quality. After-roast darkening was artificially induced in 3 cultivars by incubating nut-in-shell of high moisture content (about 22% w/w) at elevated temperatures in either sealed or unsealed polyethylene bags before drying to 1.5% kernel moisture. After oil roasting, darkening was more evident in kernel from nut-in-shell incubated for 24 h in sealed bags at temperatures greater than or equal to 47.5°C. At an incubation temperature of 50°C the critical incubation period was 12 h for nut-in-shell treated in sealed bags. In raw kernel induced to exhibit high after-roast darkening upon roasting, the concentrations of the hexoses, glucose and fructose were elevated and levels of sucrose were reduced compared to non-induced kernel. The change in kernel sugar composition increased with increasing incubation temperature. A loss in cellular viability was also associated with kernel susceptibility to after-roast darkening. These results indicate that after-roast darkening might result from reactions, possibly enzymatic, that change the kernel sugar composition as a result of a loss in membrane integrity.
Carcass traits, meat quality and muscle enzyme activity in strains of Merino wether hoggets
Authors: Hopkins D. L. , Hatcher S. , Pethick D. W. , Thornberry K. J.
Published: November 2005

The carcass characteristics, meat quality and specific muscle enzyme activity were studied in 342 Merino wether hoggets representing 7 bloodlines comprising 2 superfine lines, 2 fine wool lines, 2 medium wool lines and 1 broad wool line over 2 years. All animals were supplemented at pasture for 5 weeks before slaughter with high energy pellets. Fat levels in the superfine bloodlines based on total tissue depth over the 12th rib, 110 mm from the midline were much greater than in other lines. This also applied to fat depth measured over the longissimus thoracis et lumborum (LL) muscle for one of the superfine bloodlines when adjusted to the same carcass weight. Differences in LL muscle dimensions were minor, although the broad wool bloodline had a lower depth which translated into a smaller cross-sectional area. Significant differences were detected between bloodlines for muscle pH with superfine animals having the highest values for the LL. The differences for the semitendinosus muscle were less consistent between bloodlines, but of the bloodlines the broad wool line had the lowest pH levels in both muscles. There were few differences between bloodlines for the meat colour parameters measured on the LL. In the second year, muscle samples were taken to determine the activity of fructose 1,6-bis-phosphatase, lactate dehydrogenase (LDH), isocitrate dehydrogenase (ICDH) and the concentration of myoglobin, indicators of anaerobic and aerobic metabolism. Samples from 50 carcasses were selected from a medium wool and a superfine bloodline (2 × 25) based on LL muscle pH values. Of the enzymes, only ICDH activity was different between the 2 bloodlines, with muscle from the medium wool bloodline having a significantly higher activity than muscle from the superfine bloodline. This indicates a greater aerobic capacity in the muscle of the medium wool bloodline. The significantly lower muscle pH for medium wool bloodline was mirrored by a lower glycolytic capacity expressed as the LDH/ICDH ratio with a correlation of 0.46. Thus in this dataset, a high pH is related to a change in energy metabolism as reflected by the aerobic/anaerobic capacity of the muscle and this may be a reflection of a change in fibre type frequency, but this remains to be validated.
Establishment and summer survival of the perennial legumes, Dorycnium hirsutum and D. rectum in Mediterranean environments
Authors: Bell L. W. , Moore G. A. , Ewing M. A. , Bennett S. J.
Published: November 2005

The genus Dorycnium has been identified for its potential use as a forage plant for southern Australia, but little is known about factors affecting establishment and survival. This investigation examined some factors affecting the establishment of D. hirsutum and D. rectum in Mediterranean environments of south-west Western Australia. The population dynamics of D. hirsutum and D. rectum seedlings were investigated during the summer drought in 4 environments. The effect of time of sowing on establishment and survival of D. hirsutum was tested as a management option for improving establishment of these species. Poor seedling performance was observed in both Dorycnium species. Less than 20% of D. rectum plants survived the summer drought at all locations, compared with >50% for D. hirsutum seedlings. Poor seedling vigour coupled with weed competition resulted in low plant numbers at 2 sites. Compared with autumn sowings, populations of D. hirsutum sown in August and September had lower plant densities before summer due to poorer seedling emergence. Plant numbers declined during the summer in all plots, but losses were greatest in those sown in September. In both experiments, small D. hirsutum plants survived in plots where little competition was present. Improvements in seedling vigour may be possible with plant breeding but establishment methods that reduce weed competition are valuable. Spring sowing may enable effective weed control before seeding, but later sowings run the risk of reducing seedling emergence and survival.
Growth rates of barramundi, Lates calcarifer (Bloch), in Papua new Guinea
Authors: Reynolds LF , Moore R
Published: November 2005

Growth rates of L. calcarifer in western Papua were determined using modal progression in length- frequency samples and analysis of increases in lengths of tagged fish. Growth was rapid, the Von Bertalanffy parameters being K = 0.128, L∞ = 138 cm and t0 = -1.12 years. The length-weight relationship was W = 0.0106l3.02, where W is weight measured in grams and I is length measured in centimetres.
Revison of the Tasmanian genus of freshwater crayfish Astacopsis Huxley (Decapoda : Parastacidae)
Authors: Swain R , Richardson AMM , Hortle M
Published: November 2005

Astacopsis Huxley is revised by examination of a wide range of morphological characters. The number of species is reduced from four to two by synonymy. Variation in spination is examined in A. franklinii in relation to geographical distribution (based upon the major drainage systems in Tasmania), animal size and habitat; spininess is found to relate predominantly to animal size. The distribution of Astacopsis within Tasmania is greatly extended and previous reports of geographically separate species' boundaries, indicating limited distributions. can no longer be accepted. Synonymies and diagnoses are provided for A. franklinii and A. gouldi, and a key to their identification is presented.
HIV testing in an urgent-care clinic
Authors: Murphy Keith , Grusky Oscar , Roberts Kathleen Johnston , Swanson Aimee-Noelle
Published: November 2005

Background: Early detection of HIV is increasingly important in light of advances in HIV research and treatment. Although treatment advances offer the potential to curtail HIV incidence and seroprevalence, the full benefits remain unrealised because many infected individuals remain unaware of their serostatus. An intensive observational study of HIV testing and counselling was undertaken in a large health maintenance organisation’s urgent-care clinic (UCC) for non-threatening illnesses and non-traumatic injuries in order to better understand the HIV testing process in a medical setting. Methods: Multiple data collection strategies, including observation, semi-structured interviews and document and policy analyses, were used in order to identify key factors influencing HIV testing. The study examined physicians’, nurses’ and physician’s assistants’ relationships with patients in the UCC. Results: It was found that HIV testing in the UCC is highly variable because some patients are asked about their sexual risk histories and given HIV prevention education materials and others are not. Moreover, for those patients who do receive these components of testing, the content of both the risk assessments and HIV prevention counselling varies from patient to patient. Findings also highlight the problematic nature of providing HIV test results in an UCC. Conclusions: A number of implementation issues were found to be relevant to the new US Centers for Disease Control and Prevention (CDC) policy of making HIV testing a routine feature of medical care. The study results suggest the need for organisationally fine-tuned interventions designed to improve the process of testing patients for HIV in medical settings.
Transthyretin constitutes a functional component in pancreatic β-cell stimulus-secretion coupling
Authors: Refai Essam , Dekki Nancy , Yang Shao-Nian , Imreh Gabriela , Cabrera Over , Yu Lina , Yang Guang , Norgren Svante , Rössner Sophia M. , Inverardi Luca , Ricordi Camillo , Olivecrona Gunilla , Andersson Mats , Jörnvall Hans , Berggren Per-Olof , Juntti-Berggren Lisa
Published: November 2005

Transthyretin (TTR) is a transport protein for thyroxine and, in association with retinol-binding protein, for retinol, mainly existing as a tetramer
in vivo
. We now demonstrate that TTR tetramer has a positive role in pancreatic β-cell stimulus-secretion coupling. TTR promoted glucose-induced increases in cytoplasmic free Ca
2+
concentration ([Ca
2+
]
i
) and insulin release. This resulted from a direct effect on glucose-induced electrical activity and voltage-gated Ca
2+
channels. TTR also protected against β-cell apoptosis. The concentration of TTR tetramer was decreased, whereas that of a monomeric form was increased in sera from patients with type 1 diabetes. The monomer was without effect on glucose-induced insulin release and apoptosis. Thus, TTR tetramer constitutes a component in normal β-cell function. Conversion of TTR tetramer to monomer may be involved in the development of β-cell failure/destruction in type 1 diabetes.
Reliable prediction of transcription factor binding sites by phylogenetic verification
Authors: Li Xiaoman , Zhong Sheng , Wong Wing H.
Published: November 2005

We present a statistical methodology that largely improves the accuracy in computational predictions of transcription factor (TF) binding sites in eukaryote genomes. This method models the cross-species conservation of binding sites without relying on accurate sequence alignment. It can be coupled with any motif-finding algorithm that searches for overrepresented sequence motifs in individual species and can increase the accuracy of the coupled motif-finding algorithm. Because this method is capable of accurately detecting TF binding sites, it also enhances our ability to predict the cis-regulatory modules. We applied this method on the published chromatin immunoprecipitation (ChIP)-chip data in
Saccharomyces cerevisiae
and found that its sensitivity and specificity are 9% and 14% higher than those of two recent methods. We also recovered almost all of the previously verified TF binding sites and made predictions on the cis-regulatory elements that govern the tight regulation of ribosomal protein genes in 13 eukaryote species (2 plants, 4 yeasts, 2 worms, 2 insects, and 3 mammals). These results give insights to the transcriptional regulation in eukaryotic organisms.
Hzf protein regulates dendritic localization and BDNF-induced translation of type 1 inositol 1,4,5-trisphosphate receptor mRNA
Authors: Iijima Takatoshi , Imai Takao , Kimura Yuki , Bernstein Alan , Okano Hirotaka James , Yuzaki Michisuke , Okano Hideyuki
Published: November 2005

The localization of certain mRNAs to dendrites and their local translation in synaptic regions are proposed to be involved in certain aspects of synaptic plasticity. A
cis
-acting element within the 3′ untranslated region (3′ UTR) of the targeted mRNAs, which is bound by a trans-acting RNA-binding protein, controls the dendritic mRNA localization. Here, we identified hematopoietic zinc finger (Hzf) as a trans-acting factor that regulates the dendritic mRNA localization of the type 1 inositol 1,4,5-trisphosphate receptor (IP
3
RI), a dendritically localized mRNA in cerebellar Purkinje cells, via binding to the 3′ UTR. In
Hzf
-deficient mice, the dendritic localization of IP
3
RI mRNA and brain-derived neurotrophic factor-induced IP
3
RI protein synthesis in the cerebellum were impaired. These findings suggest that Hzf is an RNA-binding protein that controls the dendritic mRNA localization and activity-dependent translation of IP
3
RI, and may be involved in some aspects of synaptic plasticity.
Three small RNAs jointly ensure secondary metabolism and biocontrol in
Pseudomonas fluorescens
CHA0
Authors: Kay Elisabeth , Dubuis Christophe , Haas Dieter
Published: November 2005

In many Gram-negative bacteria, the GacS/GacA two-component system positively controls the expression of extracellular products or storage compounds. In the plant-beneficial rhizosphere bacterium
Pseudomonas fluorescens
CHA0, the GacS/GacA system is essential for the production of antibiotic compounds and hence for biological control of root-pathogenic fungi. The small (119-nt) RNA RsmX discovered in this study, together with RsmY and RsmZ, forms a triad of GacA-dependent small RNAs, which sequester the RNA-binding proteins RsmA and RsmE and thereby antagonize translational repression exerted by these proteins in strain CHA0. This small RNA triad was found to be both necessary and sufficient for posttranscriptional derepression of biocontrol factors and for protection of cucumber from
Pythium ultimum
. The same three small RNAs also positively regulated swarming motility and the synthesis of a quorum-sensing signal, which is unrelated to
N
-acyl-homoserine lactones, and which autoinduces the Gac/Rsm cascade. Expression of RsmX and RsmY increased in parallel throughout cell growth, whereas RsmZ was produced during the late growth phase. This differential expression is assumed to facilitate fine tuning of GacS/A-controlled cell population density-dependent regulation in
P. fluorescens
.
The role of opportunity in the unintentional introduction of nonnative ants
Authors: Suarez Andrew V. , Holway David A. , Ward Philip S.
Published: November 2005

A longstanding goal in the study of biological invasions is to predict why some species are successful invaders, whereas others are not. To understand this process, detailed information is required concerning the pool of species that have the opportunity to become established. Here we develop an extensive database of ant species unintentionally transported to the continental United States and use these data to test how opportunity and species-level ecological attributes affect the probability of establishment. This database includes an amount of information on failed introductions that may be unparalleled for any group of unintentionally introduced insects. We found a high diversity of species (232 species from 394 records), 12% of which have become established in the continental United States. The probability of establishment increased with the number of times a species was transported (propagule pressure) but was also influenced by nesting habit. Ground nesting species were more likely to become established compared with arboreal species. These results highlight the value of developing similar databases for additional groups of organisms transported by humans to obtain quantitative data on the first stages of the invasion process: opportunity and transport.
Chromatin domain activation via GATA-1 utilization of a small subset of dispersed GATA motifs within a broad chromosomal region
Authors: Im Hogune , Grass Jeffrey A. , Johnson Kirby D. , Kim Shin-Il , Boyer Meghan E. , Imbalzano Anthony N. , Bieker James J. , Bresnick Emery H.
Published: November 2005

Cis elements that mediate transcription factor binding are abundant within genomes, but the rules governing occupancy of such motifs in chromatin are not understood. The transcription factor GATA-1 that regulates red blood cell development binds with high affinity to GATA motifs, and initial studies suggest that these motifs are often unavailable for occupancy in chromatin. Whereas GATA-2 regulates the differentiation of all blood cell lineages via GATA motif binding, the specificity of GATA-2 chromatin occupancy has not been studied. We found that conditionally active GATA-1 (ER-GATA-1) and GATA-2 occupy only a small subset of the conserved GATA motifs within the murine β-globin locus. Kinetic analyses in GATA-1-null cells indicated that ER-GATA-1 preferentially occupied GATA motifs at the locus control region (LCR), in which chromatin accessibility is largely GATA-1-independent. Subsequently, ER-GATA-1 increased promoter accessibility and occupied the β
major
promoter. ER-GATA-1 increased erythroid Krüppel-like factor and SWI/SNF chromatin remodeling complex occupancy at restricted LCR sites. These studies revealed three phases of β-globin locus activation: GATA-1-independent establishment of specific chromatin structure features, GATA-1-dependent LCR complex assembly, and GATA-1-dependent promoter complex assembly. The differential utilization of dispersed GATA motifs therefore establishes spatial/temporal regulation and underlies the multistep activation mechanism.
Temperature-driven decoupling of key phases of organic matter degradation in marine sediments
Authors: Weston Nathaniel B. , Joye Samantha B.
Published: November 2005

The long-term burial of organic carbon in sediments results in the net accumulation of oxygen in the atmosphere, thereby mediating the redox state of the Earth's biosphere and atmosphere. Sediment microbial activity plays a major role in determining whether particulate organic carbon is recycled or buried. A diverse consortium of microorganisms that hydrolyze, ferment, and terminally oxidize organic compounds mediates anaerobic organic matter mineralization in anoxic sediments. Variable temperature regulation of the sequential processes, leading from the breakdown of complex particulate organic carbon to the production and subsequent consumption of labile, low-molecular weight, dissolved intermediates, could play a key role in controlling rates of overall organic carbon mineralization. We examined sediment organic carbon cycling in a sediment slurry and in flow through bioreactor experiments. The data show a variable temperature response of the microbial functional groups mediating organic matter mineralization in anoxic marine sediments, resulting in the temperature-driven decoupling of the production and consumption of organic intermediates. This temperature-driven decoupling leads to the accumulation of labile, low-molecular weight, dissolved organic carbon at low temperatures and low-molecular weight dissolved organic carbon limitation of terminal metabolism at higher temperatures.
Business Reactions to the 2001 Foot and Mouth Disease Outbreak in Scotland
Authors: Kenyon Wendy , Gilbert Alana
Published: November 2005

The paper focuses on two aspects of the 2001 foot and mouth disease (FMD) outbreak in Scotland that have been largely ignored: first, business managers perceptions of the impact of FMD during and immediately after the outbreak; and second, reactions to the outbreak in terms of action taken by businesses and advice sought. A panel survey of non-farm businesses conducted in April, June and September of 2001 is analysed to shed light on these issues. We find that even at the time, the vast majority of businesses did not report any real impact, although businesses in rural areas and in the tourism industry were more likely to feel some impact - either positive or negative. We show that business managers appeared to favour private sources of advice, although some public sources were found to be very useful, and that some actions, such as increased advertising in tourism businesses, could be more effective than others, such as making redundancies. We conclude with a discussion of the implications of the findings for contingency planning in the event of future FMD outbreaks.
Evolution of skeletal type e–c coupling
Authors: Di Biase Valentina , Franzini-Armstrong Clara
Published: November 2005

The functional separation between skeletal and cardiac muscles, which occurs at the threshold between vertebrates and invertebrates, involves the evolution of separate contractile and control proteins for the two types of striated muscles, as well as separate mechanisms of contractile activation. The functional link between electrical excitation of the surface membrane and activation of the contractile material (known as excitation–contraction [e–c] coupling) requires the interaction between a voltage sensor in the surface membrane, the dihydropyridine receptor (DHPR), and a calcium release channel in the sarcoplasmic reticulum, the ryanodine receptor (RyR). Skeletal and cardiac muscles have different isoforms of the two proteins and present two structurally and functionally distinct modes of interaction.

We use structural clues to trace the evolution of the dichotomy from a single, generic type of e–c coupling to a diversified system involving a novel mechanism for skeletal muscle activation. Our results show that a significant structural transition marks the protochordate to the Craniate evolutionary step, with the appearance of skeletal muscle–specific RyR and DHPR isoforms.
Coordinated oncogenic transformation and inhibition of host immune responses by the PAX3-FKHR fusion oncoprotein
Authors: Nabarro Stephen , Himoudi Nourredine , Papanastasiou Antigoni , Gilmour Kimberly , Gibson Sian , Sebire Neil , Thrasher Adrian , Blundell Michael P. , Hubank Mike , Canderan Glenda , Anderson John
Published: November 2005

Tumors have evolved elaborate mechanisms for evading immune detection, such as production of immunoinhibitory cytokines and down-regulation of major histocompatibility complex (MHC) expression. We have studied PAX3-FKHR as an example of an oncogenic fusion protein associated with an aggressive metastatic cancer. We show that PAX3-FKHR alters expression of genes that are normally regulated by Janus kinase/signal transducer and activator of transcription (STAT) signaling pathways. This occurs as a result of a specific interaction between PAX3-FKHR and the STAT3 transcription factor, which results in a dramatic reduction in tumor MHC expression, and an alteration in local cytokine concentrations to inhibit surrounding inflammatory cells and immune detection. Collectively, these data show that an oncogenic transcription factor can promote tumor growth and tissue invasion while inhibiting local inflammatory and immune responses. This is the first time that an immunomodulatory role has been described for an oncogenic fusion protein.
The many roads to cross-presentation
Authors: Groothuis Tom A.M. , Neefjes Jacques
Published: November 2005

Cross-presentation of extracellular antigens by MHC class I molecules is required for priming cytotoxic T lymphocytes (CTLs) at locations remote from the site of infection. Various mechanisms have been proposed to explain cross-presentation. One such mechanism involves the fusion of the endoplasmic reticulum (ER) with the endosomal-phagosomal system, in which the machinery required for peptide loading of MHC class I molecules is introduced directly into the phagosome. Here, we discuss the evidence for and against the ER-phagosome concept as well as other possible mechanisms of cross-presentation.
Invariant measures for the horocycle flow on periodic hyperbolic surfaces
Authors: Ledrappier François , Sarig Omri
Published: November 2005

We describe the ergodic invariant Radon measures for the horocycle flow on general (infinite) regular covers of finite volume hyperbolic surfaces. The method is to establish a bijection between these measures and the positive minimal eigenfunctions of the Laplacian of the covering surface.
Regulation of an intergenic transcript controls adjacent gene transcription in Saccharomyces cerevisiae
Authors: Martens Joseph A. , Wu Pei-Yun Jenny , Winston Fred
Published: November 2005

Recent studies have revealed that transcription of noncoding, intergenic DNA is abundant among eukaryotes. However, the functions of this transcription are poorly understood. We have previously shown that in Saccharomyces cerevisiae, expression of an intergenic transcript, SRG1, represses the transcription of the adjacent gene, SER3, by transcription interference. We now show that SRG1 transcription is regulated by serine, thereby conferring regulation of SER3, a serine biosynthetic gene. This regulation requires Cha4, a serine-dependent activator that binds to the SRG1 promoter and is required for SRG1 induction in the presence of serine. Furthermore, two coactivator complexes, SAGA and Swi/Snf, are also directly required for activation of SRG1 and transcription interference of SER3. Taken together, our results elucidate a physiological role for intergenic transcription in the regulation of SER3. Moreover, our results demonstrate a mechanism by which intergenic transcription allows activators to act indirectly as repressors.
Molecular mechanism of light responses in Neurospora: from light-induced transcription to photoadaptation
Authors: He Qiyang , Liu Yi
Published: November 2005

Blue light regulates many molecular and physiological activities in a large number of organisms. In Neurospora crassa, a eukaryotic model system for studying blue-light responses, the transcription factor and blue-light photoreceptor WHITE COLLAR-1 (WC-1) and its partner WC-2 are central to blue-light sensing. Neurospora's light responses are transient, that is, following an initial acute phase of induction, light-regulated processes are down-regulated under continuous illumination, a phenomenon called photoadaptation. The molecular mechanism(s) of photoadaptation are not well understood. Here we show that a common mechanism controls the light-induced transcription of immediate early genes (such as frq, al-3, and vvd) in Neurospora, in which light induces the binding of identical large WC-1/WC-2 complexes (L-WCC) to the light response elements (LREs) in their promoters. Using recombinant proteins, we show that the WC complexes are functional without the requirement of additional factors. In vivo, WCC has a long period photocycle, indicating that it cannot be efficiently used for repeated light activation. Contrary to previous expectations, we demonstrate that the light-induced hyperphosphorylation of WC proteins inhibits bindings of the L-WCC to the LREs. We show that, in vivo, due to its rapid hyperphosphorylation, L-WCC can only bind transiently to LREs, indicating that WCC hyperphosphorylation is a critical process for photoadaptation. Finally, phosphorylation was also shown to inhibit the LRE-binding activity of D-WCC (dark WC complex), suggesting that it plays an important role in the circadian negative feedback loop.
NKp46 and NKG2D receptor expression in NK cells with CD56dim and CD56bright phenotype: regulation by histamine and reactive oxygen species
Authors: Romero Ana I. , Thorén Fredrik B. , Brune Mats , Hellstrand Kristoffer
Published: November 2005

The cytotoxicity of natural killer (NK) cells is dependent on the interaction between target cell ligands and a series of stimulatory receptors on NK cells. Two of these triggering receptors, the NKp46 natural cytotoxicity receptor (NKp46) and the major histocompatibility complex (MHC) class I‐interactive NKG2D receptor, are deficiently expressed by NK cells recovered from patients with acute myeloid leukaemia (AML), but little is known regarding the regulation of NKp46 and NKG2D expression. Here we report that mononuclear and polymorphonuclear phagocytes downregulate the cell surface density of NKp46 and NKG2D on NK cells with CD56dim phenotype in vitro by a mechanism that is dependent on the availability of phagocyte‐derived reactive oxygen species (ROS). Histamine maintained NKp46 and NKG2D expression despite the presence of inhibitory phagocytes by targeting an H2 receptor on phagocytes. By contrast, NKp46 and NKG2D expression by the CD56bright subset of NK cells was resistant to inhibition by phagocytes. Our findings are suggestive of a novel mechanism of relevance to the regulation of NKp46/NKG2D receptor expression. Moreover, our findings suggest that the previously reported action of histamine on NK cell‐mediated killing of leukaemic cells may be related to the preservation of activatory NK‐cell receptors.
Non‐lethal predator effects on the performance of a native and an exotic crayfish species
Authors: NYSTRÖM PER
Published: November 2005

1. I tested the hypothesis that the potential for non‐lethal effects of predators are more important for overall performance of the fast‐growing exotic signal crayfish (Pacifastacus leniusculus Dana) than for the slower growing native noble crayfish (Astacus astacus L.). I further tested if omnivorous crayfish switched to feed on less risky food sources in the presence of predators, a behaviour that could reduce the feeding costs associated with predator avoidance.

2. In a 2 month long outdoor pool experiment, I measured behaviour, survival, cheliped loss, growth, and food consumption in juvenile noble or signal crayfish in pools with either a caged predatory dragonfly larvae (Aeshna sp.), a planktivorous fish that do not feed on crayfish (sunbleak, Leucaspius delineatus Heckel), or predator‐free controls. Crayfish had access to multiple food sources: live zooplankton, detritus and periphyton. Frozen chironomid larvae were also supplied ad libitum outside crayfish refuges, simulating food in a risky habitat.

3. Crayfish were mainly active during hours of darkness, with signal crayfish spending significantly more time outside refuges than noble crayfish. The proportion of crayfish outside refuges varied between crayfish species, time and predator treatment, with signal crayfish spending more time in refuges at night in the presence of fish.

4. Survival in noble crayfish was higher than in signal crayfish, and signal crayfish had a higher frequency of lost chelipeds, indicating a high level of intraspecific interactions. Crayfish survival was not affected by the presence of predators.

5. Gut‐contents analysis and stable isotope values of carbon (δ13C) and nitrogen (δ15N) indicated that the two crayfish species had similar food preferences, and that crayfish received most of their energy from feeding on invertebrates (e.g. chironomid larvae), although detritus was the most frequent food item in their guts. Signal crayfish guts were more full than those of noble crayfish, but signal crayfish in pools with fish contained significantly less food and fewer had consumed chironomids compared with predator‐free controls. Length increase of signal crayfish (35%) was significantly higher than of noble crayfish (20%), but signal crayfish in pools with fish grew less than in control pools.

6. This short‐term study indicates that fish species that do not pose a lethal threat to an organism may indirectly cause reductions in growth by affecting behaviour and feeding. This may occur even though prey are omnivorous and have access to and consume multiple food sources. These non‐lethal effects of predators are expected to be particularly important in exotic crayfish species that show a general response to fish, have high individual growth rates, and when their feeding on the most profitable food source is reduced.
Changing nutrient levels in Grasmere, English Lake District, during recent centuries
Authors: BARKER P. A. , PATES J. M. , PAYNE R. J. , HEALEY R. M.
Published: November 2005

1. Historical nutrient changes in Grasmere were investigated using a 300‐year record derived from six sediment cores. One core was investigated at high resolution for diatoms, total sedimentary phosphorus, and loss‐on‐ignition (LOI), and was dated using 210Pb and 137Cs. Six other cores were scanned for magnetic susceptibility, diatoms and LOI to confirm the stratigraphic integrity of the primary record.

2. A rise in nutrient levels occurred after 1855 AD. This event was marked by a shift away from benthic diatom assemblages and a rise in Asterionella formosa. The onset of eutrophication from 1855 corresponds to the expansion of the local and tourist population in the area.

3. The replacement of A. formosa with Cyclotella spp. ca 1945–65 indicates reduced nutrient loads, possibly because of enhanced flushing brought about by the seasonal rainfall distribution.

4. After 1965 a step‐wise increase in both absolute and relative amounts of Asterionella was found. High sedimentary P and diatom inferred TP confirmed the high nutrient loading of the lake. Nutrient increase is attributable to problems with the Grasmere village sewage system and the installation of a wastewater treatment works (WwTW) on the River Rothay in 1971. Modifications to the WwTW in 1982 caused an initial improvement, but have not led to a full recovery to pre‐1965 ecological conditions.

5. The diatom record indicates a further improvement after 1990 by a return toward Achnanthes minutissima.

6. The sedimentary archive of sensitive sites provides important benchmarks against which to judge the attainment of water quality targets.
Empowerment in parents of school‐aged children with and without developmental disabilities
Authors: Nachshen J. S. , Minnes P.
Published: November 2005

Background  Despite the widespread use of the term ‘empowerment’ in clinical literature to describe both a desirable process and the outcome of service delivery, the term remains more of a theoretical than practical construct. This study examined the factors that contribute to empowerment in parents of school‐aged children with and without developmental disabilities (DD) using the Double ABCX model of family adaptation contrasted with the linear ACBX model.

Methods  Parents of children with (n = 100, 97% mothers) and without (n = 100, 98% mothers) DD completed questionnaires relating to child behaviour problems, parent stress and well‐being, and formal and informal support. Structural equation modelling was used

Results  Parents of children with DD reported more child behaviour problems, more stress, less well‐being and more social support than parents of children without DD. Structural equation modelling supported the ACBX model for both groups. A linear relationship was found in which parent well‐being and resources mediated the relationship between the stressor (child behaviour problems) and the outcome (empowerment).

Conclusions  The results of the current study support Hastings and Taunt's assertion in 2002, in that empowerment was adequately explained using a traditional model of family functioning. The significant prediction offered by the parent's resources points to the need to deliver services in a manner that is more family‐centred. In the education system, this means providing parents with clear messages regarding the schools goals, clarifying the parent's rights and responsibilities, including the parent in planning and decision making, respecting their knowledge as caregivers and supporting their hopes for their child.
Stability and change in cognitive ability over the life span: a comparison of populations with and without Down's syndrome
Authors: Carr J.
Published: November 2005

Background  Longitudinal studies show that in the general population IQ declines with age: early and rapidly in the case of performance IQ, later and more slowly in the case of verbal IQ. These populations have not apparently included people with intellectual disabilities (ID).

Method  A literature search identified 11 studies, some cross‐sectional and others longitudinal, which provided data on a variety of verbal and performance tests, over periods from 3 to 19 years, on older people with ID. Following statistical advice the results from the different tests were converted into the equivalent of, for verbal scores, British Picture Vocabulary Scale, and for performance scores, Leiter International Performance Scale, raw scores. Percentage change between earlier and later scores was then calculated.

Results  With one exception the studies considered tend to show verbal ability declining relatively more, and performance ability declining relatively less, than has been shown to occur in the general population. Potential confounding factors, such as population attrition, cohort effects, etc., are thought not to have affected these results.

Conclusions  The pattern of change with age in verbal and performance ability appears different in people with ID from that seen in the general population. Some possible reasons for this difference are discussed.
Investigation of Japanese quail (Coturnix japonica) as a pharmacokinetic model for cockatiels (Nymphicus hollandicus) and Poicephalus parrots via comparison of the pharmacokinetics of a single intravenous injection of oxytetracycline hydrochloride
Authors: OSOFSKY A. , TELL L. A. , KASS P. H. , WETZLICH S. E. , NUGENT‐DEAL J. , CRAIGMILL A. L.
Published: November 2005

The purpose of this study was to determine whether Japanese quail (Coturnix japonica) would serve as a pharmacokinetic animal model for two small companion parrots: cockatiels (Nymphicus hollandicus) and Poicephalus parrots. Oxytetracycline (OTC) was the pharmacologic agent chosen for this study as it is eliminated primarily by renal glomerular filtration and undergoes minimal metabolism. A single intravenous injection of 20 mg/kg oxytetracycline hydrochloride was administered to the three study groups and blood samples were obtained at 5, 10, 15, and 30 min post‐OTC injection as well as 1, 2, 4, 8, 12 and 24 h post‐OTC injection. Quantification of plasma OTC was accomplished using a standardized microbial inhibition assay. Naïve‐pooled data (NPD) analysis of the plasma concentration–time profile of OTC best fit a two‐compartment open model for all three avian species. Noncompartmental analysis of the mean data yielded the following parameters for quail, cockatiels and Poicephalus parrots respectively: λz = 3.14, 4.57, 3.71 h; AUC = 38.9, 42.7, 49.6 μg·h/mL; and Cl = 514, 468, 403 mL/h/kg. Based on the similarity of these pharmacokinetic parameters, it appears that quail could be used as a model species to predict the appropriate OTC dosing regimen for small psittacine birds. A bootstrap procedure was also applied to these sparse data sets for both compartmental and noncompartmental analysis. The bootstrap procedure allowed for the calculation of variability of parameters; however, the estimates of the parameters were very similar to those calculated using the NPD and the data mean values.
An original system for the continuous monitoring of antimicrobial use in poultry production in France
Authors: CHAUVIN C. , LE BOUQUIN‐LENEVEU S. , HARDY A. , HAGUET D. , ORAND J. P. , SANDERS P.
Published: November 2005

Data collection at the flock level on a continuous basis, for antimicrobial use surveillance purposes, provides a complex challenge. Using existing on‐farm records, produced as part of the regulations for meat inspection, a sampling scheme was implemented to collect on a simple, representative and continuous basis, the forms providing history of antimicrobial consumption of poultry flocks slaughtered in Brittany. Relational database‐stored information provided by the forms includes treatment purpose, antimicrobial drug administered, age at treatment and treatment duration. The aim of this study was to collect information describing antimicrobial drug use quantitatively and qualitatively, by computing the frequency of antimicrobial use according to species, therapeutic class, treatment purpose, duration, and animal age at treatment. A study was carried out to check the validity of farmers’ declarations. Examples of data and results are presented such as the relative importance of the different antimicrobial classes in relation to the live weight treated, which shows that beta‐lactams and tetracyclines are the main classes used in broilers and turkeys respectively. Average bird weight at treatment was 0.5 kg for a broiler and 3 kg for a turkey. Nevertheless, several ‘at‐risk’ periods could be identified. Initial results after 1 year of data collection showed that this surveillance system provides valid, detailed and useful data about antimicrobial drug use in poultry production at a low cost and with only a moderate time involvement.
Quantitative analysis of the effect of probenecid on pharmacokinetics of 99mTc‐mercaptoacetyltriglycine in dogs
Authors: KAKIZAKI T. , YOKOYAMA Y. , NATSUHORI M. , YAMADA N. , HASHIMOTO M. , SATO K. , ITO N. , DANIEL G. B.
Published: November 2005

Effect of probenecid on pharmacokinetics of 99mTc‐mercaptoacetylytriglycine (99mTc‐MAG3) in dogs was investigated before (control), and after 15 min and 24 h of i.v. injection of probenecid (20 mg/kg). Plasma concentration–time profiles of 99mTc‐MAG3 were described with a two‐compartment open model. Plasma 99mTc‐MAG3 clearances (Clp, ml/min/kg) were 7.9 ± 0.5, 3.3 ± 0.5 and 4.8 ± 1.3 in control, 15 min and 24 h after probenecid administration respectively. Similarly, the biological half‐lives at elimination phase (t1/2, h) were 0.61 ± 0.09, 0.79 ± 0.11 and 0.74 ± 0.12, and volumes of distribution at steady state (Vdss, L/kg) were 0.29 ± 0.04, 0.20 ± 0.05 and 0.25 ± 0.06 respectively. The prolonged biological half‐life and decreased Vdss decreased Clp significantly. Clp was a function of plasma probenecid concentration based on Michaelis–Menten kinetics. The maximum Clp inhibition (Imax) by probenecid and the plasma probenecid concentration that induced 50% of Imax (I50) were estimated to be 72 ± 12% and 13 ± 8 μg/ml respectively. This means that the rest (about 28%) of the Clp is not blocked by probenecid alone, suggesting the possibility of another route(s) of elimination or renal transporters which are independent from probenecid. Moreover, inter‐species correlation between Clp of 99mTc‐MAG3 and body weight are discussed.
Anti‐phagocytic mechanisms of Streptococcus pyogenes: binding of fibrinogen to M‐related protein
Authors: Courtney Harry S. , Hasty David L. , Dale James B.
Published: November 2005

A key attribute of invasive Streptococcus pyogenes is their ability to resist phagocytosis and multiply in human blood. M‐related protein (Mrp) is a major anti‐phagocytic factor but the mechanism whereby it helps streptococci to evade phagocytosis has not been demonstrated. We investigated phagocytosis resistance in a strain of serotype M4 by inactivating the mrp gene and also the emm, enn, sof and sfbX genes and by analysing the effect on streptococcal growth in blood and on complement deposition on the bacterial surface. Inactivation of enn4 and sfbX4 had little impact on growth in blood, but ablation of mrp4, emm4 or sof4 reduced streptococcal growth in human blood, confirming that Mrp and Emm are required for optimal resistance to phagocytosis and providing the first indication that Sof may be an anti‐phagocytic factor. Moreover, antisera against Mrp4, Emm4 and Sof4 promoted the killing of S. pyogenes, but anti‐SfbX serum had no effect. Growth of S. pyogenes in blood was dependent on the presence of fibrinogen and in the absence of fibrinogen there was a twofold increase in complement deposition. Inactivation of mrp4 resulted in a loss of fibrinogen‐binding and caused a twofold increase in the binding of C3b that was inhibited by Mg‐EGTA. Mrp contained two fibrinogen‐binding sites, one of which is within a highly conserved region. These findings indicate that Mrp–fibrinogen interactions prevent surface deposition of complement via the classical pathway, thereby contributing to the ability of these streptococci to resist phagocytosis. This may be a common mechanism for evasion of phagocytosis because Mrp is expressed by approximately half of the clinical isolates of S. pyogenes.
Sedation and fiberoptic intubation of a neonate with a cystic hygroma
Authors: Bryan Y. , Chwals W. , Ovassapian A.
Published: November 2005

The flexible bronchoscope (FB) has been used to secure the difficult airway in pediatric patients (1). Difficult intubations in patients with cystic hygromas have been performed in awake patients or after the induction of general anesthesia (2). A recent case report acknowledges the challenges of performing intubations in pediatric patients under sedation because of their inability to fully cooperate (3). The following case demonstrates the two step–two fiberoptic bronchoscopic tracheal intubation performed using sedation and topical anesthesia in a neonate with a difficult airway.