bluuebunny/crossref_metadata_2025 huggingface dataset:
Conserved noncoding genomic sequences associated with a flowering-time quantitative trait locus in maize
Authors: Salvi Silvio , Sponza Giorgio , Morgante Michele , Tomes Dwight , Niu Xiaomu , Fengler Kevin A. , Meeley Robert , Ananiev Evgueni V. , Svitashev Sergei , Bruggemann Edward , Li Bailin , Hainey Christine F. , Radovic Slobodanka , Zaina Giusi , Rafalski J.-Antoni , Tingey Scott V. , Miao Guo-Hua , Phillips Ronald L. , Tuberosa Roberto
Published: June 2007

Flowering time is a fundamental trait of maize adaptation to different agricultural environments. Although a large body of information is available on the map position of quantitative trait loci for flowering time, little is known about the molecular basis of quantitative trait loci. Through positional cloning and association mapping, we resolved the major flowering-time quantitative trait locus,
Vegetative to generative transition 1
(
Vgt1
), to an ≈2-kb noncoding region positioned 70 kb upstream of an
Ap2
-like transcription factor that we have shown to be involved in flowering-time control.
Vgt1
functions as a cis-acting regulatory element as indicated by the correlation of the
Vgt1
alleles with the transcript expression levels of the downstream gene. Additionally, within
Vgt1
, we identified evolutionarily conserved noncoding sequences across the maize–sorghum–rice lineages. Our results support the notion that changes in distant cis-acting regulatory regions are a key component of plant genetic adaptation throughout breeding and evolution.
U bodies are cytoplasmic structures that contain uridine-rich small nuclear ribonucleoproteins and associate with P bodies
Authors: Liu Ji-Long , Gall Joseph G.
Published: June 2007

Uridine-rich small nuclear ribonucleoproteins (U snRNPs) are involved in key steps of pre-mRNA processing in the nucleus of eukaryotic cells. U snRNPs are enriched in the nucleus in discrete organelles that include speckles, Cajal bodies, and histone locus bodies. However, most U snRNPs are assembled in the cytoplasm, not in the nucleus. Despite extensive biochemical information, little is known about the spatial organization of U snRNPs in the cytoplasm. Here we show that U snRNPs inDrosophilaare concentrated in discrete cytoplasmic structures, which we call U bodies, because they contain the major U snRNPs. In addition to snRNPs, U bodies contain essential snRNP assembly factors, suggesting that U bodies are sites for assembly or storage of snRNPs before their import into the nucleus. U bodies invariably associate with P bodies, which are involved in RNA surveillance and decay. Genetic disruption of P body components affects the organization of U bodies, suggesting that the two cytoplasmic bodies may cooperate in regulating aspects of snRNP metabolism. The identification of U bodies provides an opportunity to correlate specific biochemical steps of snRNP biogenesis with structural features of the cytoplasm.
Charcot–Marie–Tooth disease-associated mutant tRNA synthetases linked to altered dimer interface and neurite distribution defect
Authors: Nangle Leslie A. , Zhang Wei , Xie Wei , Yang Xiang-Lei , Schimmel Paul
Published: June 2007

Charcot–Marie–Tooth (CMT) diseases are the most common heritable peripheral neuropathy. At least 10 different mutant alleles of
GARS
(the gene for glycyl-tRNA synthetase) have been reported to cause a dominant axonal form of CMT (type 2D). A unifying connection between these mutations and CMT has been unclear. Here, mapping mutations onto the recently determined crystal structure of human GlyRS showed them within a band encompassing both sides of the dimer interface, with two CMT-causing mutations being at sites that are complementary partners of a “kissing” contact across the dimer interface. The CMT phenotype is shown here to not correlate with aminoacylation activity. However, most mutations affect dimer formation (to enhance or weaken). Seven CMT-causing variants and the wild-type protein were expressed in transfected neuroblastoma cells that sprout primitive neurites. Wild-type GlyRS distributed into the nascent neurites and was associated with normal neurite sprouting. In contrast, all mutant proteins were distribution-defective. Thus, CMT-causing mutations of GlyRS share a common defect in localization. This defect may be connected in some way to a change in the surfaces at the dimer interface.
Long-term memory of individual identity in ant queens
Authors: Dreier Stephanie , van Zweden Jelle S , D'Ettorre Patrizia
Published: June 2007

Remembering individual identities is part of our own everyday social life. Surprisingly, this ability has recently been shown in two social insects. While paper wasps recognize each other individually through their facial markings, the ant,
Pachycondyla villosa
, uses chemical cues. In both species, individual recognition is adaptive since it facilitates the maintenance of stable dominance hierarchies among individuals, and thus reduces the cost of conflict within these small societies. Here, we investigated individual recognition in
Pachycondyla
ants by quantifying the level of aggression between pairs of familiar or unfamiliar queens over time. We show that unrelated founding queens of
P. villosa
and
Pachycondyla inversa
store information on the individual identity of other queens and can retrieve it from memory after 24 h of separation. Thus, we have documented for the first time that long-term memory of individual identity is present and functional in ants. This novel finding represents an advance in our understanding of the mechanism determining the evolution of cooperation among unrelated individuals.
Information-theoretic sensitivity analysis: a general method for credit assignment in complex networks
Authors: Lüdtke Niklas , Panzeri Stefano , Brown Martin , Broomhead David S , Knowles Joshua , Montemurro Marcelo A , Kell Douglas B
Published: June 2007

Most systems can be represented as networks that couple a series of nodes to each other via one or more edges, with typically unknown equations governing their quantitative behaviour. A major question then pertains to the importance of each of the elements that act as system inputs in determining the output(s). We show that any such system can be treated as a ‘communication channel’ for which the associations between inputs and outputs can be quantified via a decomposition of their mutual information into different components characterizing the main effect of individual inputs and their interactions. Unlike variance-based approaches, our novel methodology can easily accommodate correlated inputs.
Trophic network models explain instability of Early Triassic terrestrial communities
Authors: Roopnarine Peter D , Angielczyk Kenneth D , Wang Steve C , Hertog Rachel
Published: June 2007

Studies of the end-Permian mass extinction have emphasized potential abiotic causes and their direct biotic effects. Less attention has been devoted to secondary extinctions resulting from ecological crises and the effect of community structure on such extinctions. Here we use a trophic network model that combines topological and dynamic approaches to simulate disruptions of primary productivity in palaeocommunities. We apply the model to Permian and Triassic communities of the Karoo Basin, South Africa, and show that while Permian communities bear no evidence of being especially susceptible to extinction, Early Triassic communities appear to have been inherently less stable. Much of the instability results from the faster post-extinction diversification of amphibian guilds relative to amniotes. The resulting communities differed fundamentally in structure from their Permian predecessors. Additionally, our results imply that changing community structures over time may explain long-term trends like declining rates of Phanerozoic background extinction
Environmental uncertainty, autocorrelation and the evolution of survival
Authors: Metcalf C.J.E , Koons D.N
Published: June 2007

Survival is a key fitness component and the evolution of age- and stage-specific patterns in survival is a central question in evolutionary biology. In variable environments, favouring chances of survival at the expense of other fitness components could increase fitness by spreading risk across uncertain conditions, especially if environmental conditions improve in the future. Both the magnitude of environmental variation and temporal autocorrelation in the environment might therefore affect the evolution of survival patterns. Despite this, the influence of temporal autocorrelation on the evolution of survival patterns has not been addressed. Here, we use a trade-off structure which reflects the empirically inspired paradigm of acquisition and allocation of resources to investigate how the evolutionarily stable survival probability is shaped in variable, density-dependent environments. We show that temporal autocorrelation is likely to be an important aspect of environmental variability that contributes to shaping age- and stage-specific patterns of survival probabilities in nature.
Biodiversity among luminescent symbionts from squid of the genera Uroteuthis, Loliolus and Euprymna (Mollusca: Cephalopoda)
Authors: Guerrero‐Ferreira R. C. , Nishiguchi M. K.
Published: June 2007

Luminescent bacteria in the family Vibrionaceae (Bacteria: γ‐Proteobacteria) are commonly found in complex, bilobed light organs of sepiolid and loliginid squids. Although morphology of these organs in both families of squid is similar, the species of bacteria that inhabit each host has yet to be verified. We utilized sequences of 16S ribosomal RNA, luciferase α‐subunit (luxA) and the glyceraldehyde‐3‐phosphate dehydrogenase (gapA) genes to determine phylogenetic relationships between 63 strains of Vibrio bacteria, which included representatives from different environments as well as unidentified luminescent isolates from loliginid and sepiolid squid from Thailand. A combined phylogenetic analysis was used including biochemical data such as carbon use, growth and luminescence. Results demonstrated that certain symbiotic Thai isolates found in the same geographic area were included in a clade containing bacterial species phenotypically suitable to colonize light organs. Moreover, multiple strains isolated from a single squid host were identified as more than one bacteria species in our phylogeny. This research presents evidence of species of luminescent bacteria that have not been previously described as symbiotic strains colonizing light organs of Indo‐West Pacific loliginid and sepiolid squids, and supports the hypothesis of a non‐species‐specific association between certain sepiolid and loliginid squids and marine luminescent bacteria.

© The Willi Hennig Society 2007.
Varying effects of anadromous sockeye salmon on the trophic ecology of two species of resident salmonids in southwest Alaska
Authors: SCHEUERELL MARK D. , MOORE JONATHAN W. , SCHINDLER DANIEL E. , HARVEY CHRIS J.
Published: June 2007

1. Anadromous salmon transport marine‐derived nutrients and carbon to freshwater and riparian ecosystems upon their return to natal spawning systems. The ecological implications of these subsidies on the trophic ecology of resident fish remain poorly understood despite broad recognition of their potential importance.

2. We studied the within‐year changes in the ration size, composition and stable isotope signature of the diets of two resident salmonids (rainbow trout,Oncorhynchus mykiss; Arctic grayling,Thymallus arcticus) before and after the arrival of sockeye salmon (Oncorhynchus nerka) to their spawning grounds in the Bristol Bay region of southwest Alaska.

3. Ration size and energy intake increased by 480–620% for both species after salmon arrived. However, the cause of the increases differed between species such that rainbow trout switched to consuming salmon eggs, salmon flesh and blowflies that colonized salmon carcasses, whereas grayling primarily ate more benthic invertebrates that were presumably made available because of physical disturbances by spawning salmon.

4. We also observed an increase in theδ15N of rainbow trout diets post‐salmon, but not for grayling. This presumably led to the observed increase in theδ15N of rainbow trout with increasing body mass, but not for grayling.

5. Using a bioenergetics model, we predicted that salmon‐derived resources contributed a large majority of the energy necessary for growth in this resident fish community. Furthermore, the bioenergetics model also showed how seasonal changes in diet affected the stable isotope ratios of both species. These results expand upon a growing body of literature that highlights the different pathways whereby anadromous salmon influence coastal ecosystems, particularly resident fish.
Role of Sand Fly Saliva in Human and Experimental Leishmaniasis: Current Insights
Authors: Andrade B. B. , De Oliveira C. I. , Brodskyn C. I. , Barral A. , Barral‐Netto M.
Published: June 2007

Leishmaniases are wide spread diseases transmitted to their vertebrate host by infected sand fly. The saliva from these arthropods contains a vast repertoire of pharmacologically active molecules that hampers the host’s haemostatic, inflammatory and immune responses. The early interactions between Leishmania and the host’s immune response are closely linked to disease evolution or protection against the protozoan, and the ectoparasite saliva contributes directly to these interactions. Current studies have depicted these features, and these relations are being widely explored. There are concrete indications that the host response against sand fly saliva influences disease outcome in leishmaniasis. Additionally, there are demonstrations that immunization with whole sand fly saliva, or its components, leads to protection against leishmaniasis in different host species. The combination of these evidences opens up optimistic perspectives for improving vaccine development against Leishmania infection.
Multiple subcutaneous nodules leading to the diagnosis of pulmonary aspergillosis in a renal transplant recipient
Authors: Özcan Deren , Güleç Ayşe Tülin , Haberal Mehmet
Published: June 2007

Abstract:  Aspergillosis is the second most frequent opportunistic fungal infection in solid organ transplant recipients; however, cutaneous aspergillosis occurs very rarely. Herein, we report a 34‐yr‐old male renal transplant recipient with secondary cutaneous aspergillosis due to Aspergillus fumigatus in whom cutaneous lesions led to the correct diagnosis. To the best of our knowledge, this is the first case of secondary cutaneous aspergillosis reported in the setting of a solid organ transplantation.
KETANSERIN‐INDUCED BAROREFLEX ENHANCEMENT IN SPONTANEOUSLY HYPERTENSIVE RATS DEPENDS ON CENTRAL 5‐HT2A RECEPTORS
Authors: Shen Fu‐Ming , Wang Jin , Ni Can‐Rong , Yu Jian‐Guang , Wang Wei‐Zhong , Su Ding‐Feng
Published: June 2007

Ketanserin may influence baroreflex function by blocking 5‐HT2A receptors and/or α1‐adrenoceptors through central and/or peripheral mechanisms.

In the present study, we tested the hypothesis that the baroreflex sensitivity (BRS)‐enhancing effects of ketanserin are mediated by central 5‐HT2A receptors in spontaneously hypertensive rats (SHR).

Using a conjugate of a monoclonal antibody to the serotonin reuptake transporter (SERT) and the toxin saporin (anti‐SERT‐SAP), which specifically eliminates the neurons that express SERT, the effects of ketanserin (0.3 and 3.0 mg/kg, i.g.) on BRS, blood pressure (BP), heart period (HP) and blood pressure variability (BPV) were compared between conscious intact SHR and SHR pretreated with anti‐SERT‐SAP.

Immunochemistry showed that, 2 weeks after intracerebroventricular injection of the toxin, 5‐HT expression was strikingly attenuated in the brain, whereas values of BRS, BPV and BP were similar to those in the sham group. In intact SHR, 0.3 mg/kg ketanserin significantly improved BRS (191% control) and reduced BPV without affecting BP; at 3.0 mg/kg, ketanserin significantly increased BRS (197% control) and decreased BPV and BP. In toxin‐pretreated SHR, only the high dose of ketanserin improved BRS (132% control), neither of the ketanserin doses reduced BPV, but both significantly decreased BP.

We conclude that the BRS‐enhancing effects of ketanserin are mediated largely by central 5‐HT2A receptors, whereas the antihypertensive effect of ketanserin persists even after destruction of serotonergic neurons in the central nervous system.
SIMULTANEOUS GENOTYPING OF CYP2D6*3, *4, *5 AND *6 POLYMORPHISMS IN A SPANISH POPULATION THROUGH MULTIPLEX LONG POLYMERASE CHAIN REACTION AND MINISEQUENCING MULTIPLEX SINGLE BASE EXTENSION ANALYSIS
Authors: Crescenti A , Mas S , Gassó P , Baiget M , Bernardo M , Lafuente A
Published: June 2007

The aim of the present study was to perform a descriptive study of the prevalence of the four major CYP2D6 poor metaboliser (PM) alleles (*3, *4, *5 and *6) in a Spanish population (n = 290) using a method based on a new combination of multiplex long polymerase chain reaction (PCR) and minisequencing through multiplex single base extension (SBE) analysis.

The method was validated using different strategies, such as allelic discrimination assay and PCR–restriction fragment length polymorphism (RFLP).

The allele frequencies were similar to those described for other Spanish populations, namely 0.9% (95% confidence interval (CI) 0.5–1.3), 16.4% (95% CI 14.9–18.0), 2.7% (95% CI 2.0–3.4) and 0.7% (95% CI 0.3–1.0) for the *3, *4, *5 and *6 alleles, respectively. The results were satisfactory and left little doubt as to the genotypes, which were confirmed either by allelic discrimination assay (*4 and *6) or PCR‐RFLP (*3) with 100% concordance.

The present study corroborates the low prevalence of the most frequent polymorphism (CYP2D6*4) that leads to null CYP2D6 activity in Spain and the allelic geographical gradient between Caucasian populations in the north and south. The present study reports a technique for the detection of four polymorphisms that account for 98% of the CYP2D6 defect alleles. This multiplex long PCR–SBE technique is a combination of several known methods to genotype CYP2D6 alleles (*3, *4, *5 and*6). Given the importance of CYP2D6 in drug metabolism and the need to genotype a large number of samples, we believe that this method will find broad application.
INDICES OF VASCULAR STIFFNESS AND WAVE REFLECTION IN RELATION TO BODY MASS INDEX OR BODY FAT IN HEALTHY SUBJECTS
Authors: Wykretowicz Andrzej , Adamska Karolina , Guzik Przemyslaw , Krauze Tomasz , Wysocki Henryk
Published: June 2007

Obesity appears to influence vascular stiffness, an important cardiovascular risk factor. An accurate picture of arterial stiffness may be obtained when a combination of various techniques is used.

The purpose of the present study was to assess whether the body mass index (BMI) and body fat content obtained by bioimpedance were of equal value in estimating the influence of body fatness on various indices of vascular stiffness and wave reflection.

A total of 175 healthy subjects was studied. Anthropometric measurements and total body bio‐impedance analysis were performed to assess fat mass as a proportion of total body composition. Arterial stiffness and wave reflection were assessed using digital volume pulse analysis and tonometric measurement of the wave reflection indices and central haemodynamics.

Significant differences in the stiffness index (SIDVP; P < 0.0001), peripheral augmentation index (pAIx; P < 0.0001), central augmentation index (cAIx; P < 0.0001), peripheral pulse pressure (pPP; P = 0.026) and central pulse pressure (cPP; P < 0.0001) were found when the population examined was divided accordingly to tertile of body fat content. However, subdividing various indices of arterial stiffness according to the tertile of BMI did not reveal any significant differences between groups, except for pPP and cPP.

Body fat content was significantly correlated with SIDVP, pAIx, cAIx, pPP and cPP. The BMI correlated weakly with SIDVP, pPP and cPP.

In conclusion, the BMI is not very useful in predicting changes in arterial stiffness and wave reflection due to obesity. However, stiffness and wave reflection indices derived from digital volume pulse analysis, the characteristics of radial and aortic pressure waveforms and peripheral and aortic pulse pressure are all related to body fat content, as estimated by bioimpedance.
EFFECTS OF RESVERATROL ON NUMBER AND ACTIVITY OF ENDOTHELIAL PROGENITOR CELLS FROM HUMAN PERIPHERAL BLOOD
Authors: Wang Xiao‐Bin , Huang Jun , Zou Jian‐Gang , Su En‐Ben , Shan Qi‐Jun , Yang Zhi‐Jian , Cao Ke‐Jiang
Published: June 2007

It has been well established that oestrogens can increase the number of endothelial progenitor cells (EPC) by anti‐apoptotic effects. Resveratrol, a polyphenolic phytoalexin extracted from grapes and wine, has been reported to act as an oestrogen receptor agonist. We hypothesize that putative phyto‐oestrogen may promote EPC proliferation and survival in vitro.

Endothelial progenitor cells were isolated from human peripheral blood and identified immunocytochemically. Endothelial progenitor cells were incubated with resveratrol (1, 10, 25 and 50 mmol/L) or control for specified times. Cell proliferation, migration and in vitro vasculogenesis were assayed using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetra‐zolium bromide (MTT) assay, modified Boyden chamber assay and in vitro vasculogenesis detection, respectively.

Resveratrol increased the number of EPC and promoted EPC proliferation, adhesion and migration in a dose‐ and time‐dependent manner. Cell number peaked at 50 mmol/L resveratrol after incubation for 24 h compared with vehicle control (61.3 ± 5.8 vs 112.8 ± 7.2, respectively; P < 0.01).

Furthermore, cell cycle analysis showed that 50 mmol/L resveratrol significantly increased the S phase and decreased the G0/G1 phase of EPC. In addition, resveratrol increased vascular endothelial growth factor production and further induced vasculogenesis in vitro.

In conclusion, resveratrol significantly induces EPC proliferation, migration and further promotes angiogenesis in vitro.
FLAVONE INHIBITS VASCULAR CONTRACTION BY DECREASING PHOSPHORYLATION OF THE MYOSIN PHOSPHATASE TARGET SUBUNIT
Authors: Jeon Su Bun , Kim Gutae , Kim Jee In , Seok Young Mi , Kim Sang‐Hyun , Suk Kyoungho , Shin Heung‐Mook , Lee Young‐Ho , Kim In Kyeom
Published: June 2007

Flavonoids modulate vascular tone through an endothelium‐dependent or ‐independent mechanism. Although a few mechanisms for endothelium‐independent relaxation have been suggested, such as interference with protein kinase C or cAMP or cGMP phosphodiesterase, the inhibition of Ca2+release from intracellular stores or Ca2+influx from extracellular fluids, the mode of action of flavonoids remains elusive.

We hypothesized that treatment with flavone inhibits vascular smooth muscle contraction by decreasing the phosphorylation of the myosin phosphatase target subunit (MYPT1).

Rat aortic rings were denuded of endothelium, mounted in organ baths and contracted with U46619, a thromboxane A2analogue.

Flavone dose‐dependently inhibited the U46619‐induced contractile response and myosin light chain (MLC20) phosphorylation. At 10−7 mol/L, U46619 induced vascular contraction with the concomitant phosphorylation of MYPT1 at Thr855, but not at Thr697. Incubation with flavone (100 or 300 µmol/L) for 30 min attenuated the phosphorylation of MYPT1Thr855, but not MYPT1Thr697.

It is concluded that treatment with flavone inhibits vascular smooth muscle contraction by decreasing the phosphorylation of the MYPT1. These results suggest that flavone causes endothelium‐independent relaxation through, at least in part, the inhibition of p160 Rho‐associated coiled‐coil‐containing protein kinase (ROCK) signalling.
17β‐OESTRADIOL PARTIALLY ATTENUATES THE INHIBITION OF NITRIC OXIDE SYNTHASE‐3 BY ADVANCED GLYCATION END‐PRODUCTS IN HUMAN PLATELETS
Authors: Chen Lu , Liu Yuan , Cui Bota , Mi Qiongyu , Huang Yan , Fan Leming , Chen Qi , Tang James , Ferro Albert , Ji Yong
Published: June 2007

Diabetes mellitus predisposes to and female sex protects against arterial thrombosis. The aim of the present study was to determine whether advanced glycation end‐products (AGE), which accumulate in diabetes, impair platelet function through effects on platelet nitric oxide (NO) generation and whether this can be prevented by 17β‐oestradiol.

Aggregation responses of human platelet‐rich plasma to ADP were determined in the absence or presence of 200 mg/L AGE‐modified albumin (AGE‐albumin), 10−5 mol/L 17β‐oestradiol and 10−5 mol/L ICI 182 780 (the pure oestrogen receptor antagonist).

Intraplatelet cGMP, an index of bioactive NO, was measured by radioimmunoassay and expression of nitric oxide synthase (NOS)‐3, phosphoserine‐1177‐NOS‐3 and O‐glycosylated NOS‐3 was quantified by western blotting in response to these same treatments.

Advanced glycation end‐products–albumin increased platelet aggregatory responses to ADP. This increase was largely prevented by 17β‐oestradiol. Advanced glycation end‐products–albumin decreased and 17β‐oestradiol increased intraplatelet NO‐attributable cGMP and 17β‐oestradiol attenuated the AGE‐albumin‐induced decrease in NO‐attributable cGMP. Despite no effect on NOS‐3 expression, AGE‐albumin decreased and 17β‐oestradiol increased phosphoserine‐1177‐NOS‐3 and 17β‐oestradiol largely prevented the decrease in phosphoserine‐1177‐NOS‐3 induced by AGE‐albumin. Alone, AGE‐albumin increased O‐glycosylation of NOS‐3 by N‐acetylglucosamine, an effect largely inhibited by 17β‐oestradiol.

In conclusion, AGE‐albumin inhibits platelet NO biosynthesis through effects on serine phosphorylation and O‐glycosylation of platelet NOS‐3 and this may explain, at least in part, the increase in platelet aggregability induced by AGE‐albumin. These effects of AGE‐albumin are largely prevented by 17β‐oestradiol. These actions may contribute to the effects of diabetes and sex on arterial thrombosis in vivo.
ANTICONVULSANT, BUT NOT ANTIEPILEPTIC, ACTION OF VALPROATE ON AUDIOGENIC SEIZURES IN METAPHIT–TREATED RATS
Authors: Stanojlović Olivera P , Hrnčić Dragan R , Živanović Dragana P , Šušić Veselinka T
Published: June 2007

1. The blocking effects of valproate (2‐propylpentanoic acid), a standard anti‐epileptic drug, on metaphit (1‐[1‐(3‐isothiocyanatophenyl)‐cyclohexyl]‐piperidine)‐induced audiogenic seizures as a model of generalized, reflex audiogenic epilepsy in adult Wistar male rats were studied.

Rats were stimulated using an electric bell (100 ± 3 dB, 5–8 kHz, 60 s) 60 min after i.p. metaphit (10 mg/kg) injection and afterwards at hourly intervals. For power spectra and electroencephalograph (EEG) recordings, three gold‐plated screws were implanted into the skull. Different doses of valproate (50, 75 and 100 mg/kg) were injected i.p. into rats with fully developed metaphit seizures after the eighth audiogenic testing.

In metaphit‐treated animals, the EEG appeared as polyspikes, spike–wave complexes and sleep‐like patterns, whereas the power spectra were increased compared with the corresponding controls.

Valproate reduced the incidence and intensity of convulsions and prolonged the duration of the latency period in a dose‐dependent manner 4 h after administration.

The ED50 of valproate in the first hour after injection was 63.19 mg/kg (95% confidence interval 51.37–77.71 mg/kg).

None of the doses of valproate applied eliminated the EEG signs of metaphit‐provoked epileptiform activity.

Taken together, these results suggest that all doses of valproate examined acted to suppresse behavioural but not epileptic EEG spiking activity in metaphit‐induced seizures.
AGEING, OESTROGEN, PLATELETS AND THROMBOTIC RISK
Authors: Miller Virginia M , Jayachandran Muthuvel , Owen Whyte G
Published: June 2007

Adverse thrombotic cardiovascular events increase in women coincident with the onset of menopause.

Age past menopause may be an important variable in defining the benefit/risk of hormone treatments.

Few studies have examined hormonal status as a variable of ageing using a polygenomic approach of both humoral and cellular components of the coagulation system.

Longitudinal studies of a global set of platelet functions that define procoagulant activity (i.e. adhesion, aggregation, secretion and thrombin production) in individuals with documented hormonal status are needed to better understand how hormonal changes associated with ageing impact thrombotic risk.
NON‐GENOMIC VASCULAR ACTIONS OF FEMALE SEX HORMONES: PHYSIOLOGICAL IMPLICATIONS AND SIGNALLING PATHWAYS
Authors: Leung Susan WS , Teoh Hwee , Keung Wendy , Man Ricky YK
Published: June 2007

Epidemiological studies indicate a lower incidence of coronary heart disease in premenopausal women compared with age‐matched men and post‐menopausal women. Accumulating evidence suggests that this cardiovascular protection observed in premenopausal women is at least partially attributed to the direct action of oestrogens on the vascular system.

Research focused on vascular actions of 17β‐oestradiol indicates that this female sex hormone favourably modulates vascular reactivity at physiological concentrations. The vascular actions of 17β‐oestradiol appear independent of its genomic actions. Both endothelium‐dependent and ‐independent signalling cascades have been implicated in the vascular effects of 17β‐oestradiol.

However, clinical trials on hormone‐replacement therapy argue against a role of oestrogens in preventing the development of coronary heart disease. Supplementation with oestrogen is also complicated with the increased risk of breast and endometrial cancer. Hence, a better understanding of the vascular actions of 17β‐oestradiol will serve to enhance our understanding of its role in coronary heart disease.
From the mountains to the sea: assemblage structure and dynamics in Chironomidae (Insecta: Diptera) in the Clyde River estuarine gradient, New South Wales, south‐eastern Australia
Authors: Dimitriadis Sophia , Cranston Peter S
Published: June 2007

Abstract  Chironomidae (Insecta: Diptera: non‐biting midges) were surveyed at five shallow riffle stations along the estuarine gradient of the Clyde River, southern New South Wales (35°45′S, 150°15′E). Benthic populations were sampled seasonally between April 2001 and January 2002, between an uppermost fully fresh station and 7 km south of the tidal limit at Shallow Crossing, encompassing a 23 km stretch. Biological structure and integrity of chironomid assemblages, which are essentially unknown in eastern Australia's estuarine environments, were elucidated. Assemblages were diverse: from 5732 chironomid larvae, 45 species belonging to four subfamilies were identified from riffles. All chironomid assemblages were strongly structured and non‐random with respect to spatial position along the salinity gradient although relatively random with respect to temporal shifts between the five seasonal samples. Generally, the salinity gradient had strong effects on assemblage composition but no discrete brackish fauna was identifiable, and the abundance of many species declined gradually with distance from the freshest station. Dominant taxa in the brackish zone were Parakiefferiella‘variegatus’ and two species of Cladotanytarsus. Notably, the little‐known Semiocladius crassipennis Skuse (Orthocladiinae) was abundant at the most marine‐influenced station. Taxa present exclusively in freshwaters included several Tanypodinae notably absent from sites below Shallow Crossing at salinities normally tolerated in athalassic waters. Other species restricted to freshwaters included Nanocladius sp., Demicryptochironomus (Irmakia) sp., Polypedilum vespertinus (Skuse), Zavrelliella fuscoguttata (Kieffer), Riethia stictoptera (Kieffer) and Podonomopsis sp.
Lipid‐enhanced pollen and lipid‐reduced flour diets and their effect on the longevity of honey bees (Apis mellifera L.)
Authors: Manning Rob , Rutkay April , Eaton Linda , Dell Bernard
Published: June 2007

Abstract  As eucalypt pollens contain low concentrations of lipid, enhancing pollen diets with fatty acids was hypothesised to improve honey bee longevity. Different concentrations of linoleic and oleic acid added to eucalypt pollen were trialled in small cages containing approximately 1400 bees each. Bees fed diets of redgum (Corymbia calophylla (Lindl.) Hill & Johnson, formerly Eucalyptus calophylla) pollen had the lowest mortality of 22 diets tested for 6 weeks and had life spans (50%) greater than 42 days. Linoleic acid mixed with a redgum diet in concentrations >6% corresponded to life spans of 24–25 days. Bee longevity appeared to be more sensitive to oleic acid as life spans decreased to 15–21 days when diets had concentrations >2%. The life spans of bees fed soya bean flour were 26 days on low (0.6% lipid) fat, 19 days on defatted and 20 days on full‐fat diets. Bees fed lupin flour had a life span of 23 days. Adding redgum pollen to lupin flour caused increased mortality, but addition of pollen to soya bean flour was beneficial. Thus, beekeepers who choose to utilise soya bean or lupin flours as protein substitutes to pollen will have bees with reduced longevity. Bees fed redgum pollen that had been dried, crushed, irradiated and hermetically stored in a cool room for several years had similar longevity to bees fed fresh‐collected and frozen redgum pollen.
Australian biodiversity: threats for the present, opportunities for the future
Authors: Raven Peter H , Yeates David K
Published: June 2007

Abstract  Australia's insect fauna comprises a very large component of its biodiversity, and one that remains a largely unknown and untapped resource. Estimates of global and Australian insect species richness are reviewed, and Australia's insect biodiversity is placed in its biogeographical context of Mesozoic, Gondwanan connectivity and Tertiary isolation. Some unique, relict faunal elements derived from Australia's long periods of isolation are highlighted. Examples of the dramatic insect evolutionary radiations are profiled that are the consequence of successful adaptation to new biomes made available by the environmental transformations in Australia in the latter half of the Tertiary. Then conservation of Australian forests and the major processes threatening Australian biodiversity are discussed: invasive species, habitat conversion and climate change. The four components necessary to build sustainability in Australia or throughout the world are discussed: description and understanding, direct action for conservation, promoting sustainable use in balance with conservation, and providing education and information to maintain the overall effort.
Coding location in enclosed spaces: is geometry the principle?
Authors: Huttenlocher Janellen , Lourenco Stella F.
Published: June 2007

Both animals and human toddlers can find an object in a rectangular enclosure after they have been disoriented. They use geometric cues (relative lengths of walls) to discriminate among different corners (e.g. long wall to the left, short to the right). It has been claimed that this ability is ‘modular’, i.e. exclusively geometric. The present study demonstrates that the ability toddlers exhibit is a more general one, namely, an ability to discriminate relative quantity. Using a square enclosure, we show that toddlers use the relative sizes of the figures on different walls to characterize different corners. We also show that they do not use simple non‐relative features to distinguish different corners. Possible reasons for differences in the ability to use relative versus non‐relative cues are discussed.
Use it or lose it: examining preschoolers’ difficulty in maintaining and executing a goal
Authors: Marcovitch Stuart , Boseovski Janet J. , Knapp Robin J.
Published: June 2007

Individuals with low working memory capacity (e.g. preschoolers) are more prone to goal neglect, or a failure to execute a goal even though it is understood. We examined the role of goal neglect in performance on the Dimensional Change Card Sort by including ‘redundant’ cards that could be sorted without attending to the rules, as well as the traditional ‘conflict’ cards that encouraged awareness of the rules. In Experiment 1, 4‐ and 5‐year‐old children were administered two card sorts that differed on the proportion of redundant cards presented (20% vs. 80%). Children neglected the goal more often when faced with a preponderance of redundant cards, suggesting that consistent attention to the rules leads to goal maintenance. In Experiment 2, results were replicated even when the post‐switch rules were repeated on every trial. Implications for the development of working memory are discussed.
Development of beliefs about storybook reality
Authors: Woolley Jacqueline D. , Cox Victoria
Published: June 2007

The goal of this research was to assess children's beliefs about the reality status of storybook characters and events. InExperiment 1, 156 preschool age children heard realistic, fantastical, or religious stories, and their understanding of the reality status of the characters and events in the stories was assessed. Results revealed that 3‐year‐olds were more likely to judge characters as real than were 4‐ and 5‐year‐olds, but most children judged all characters as not real for all story types. Children of all ages who heard realistic stories made more claims that the events in the stories could happen in real life than did children who heard fantastical stories. Five‐year‐olds made significantly more claims that events in religious stories could happen in real life than did younger children. InExperiment 2, 136 4‐ and 5‐year‐olds heard similar stories. Results replicated those fromExperiment 1, and also indicated a growing awareness of the basic nature of realistic fiction.
LARGE DEVIATIONS IN MULTIFACTOR PORTFOLIO CREDIT RISK
Authors: Glasserman Paul , Kang Wanmo , Shahabuddin Perwez
Published: June 2007

The measurement of portfolio credit risk focuses on rare but significant large‐loss events. This paper investigates rare event asymptotics for the loss distribution in the widely used Gaussian copula model of portfolio credit risk. We establish logarithmic limits for the tail of the loss distribution in two limiting regimes. The first limit examines the tail of the loss distribution at increasingly high loss thresholds; the second limiting regime is based on letting the individual loss probabilities decrease toward zero. Both limits are also based on letting the size of the portfolio increase. Our analysis reveals a qualitative distinction between the two cases: in the rare‐default regime, the tail of the loss distribution decreases exponentially, but in the large‐threshold regime the decay is consistent with a power law. This indicates that the dependence between defaults imposed by the Gaussian copula is qualitatively different for portfolios of high‐quality and lower‐quality credits.
PORTFOLIO MANAGEMENT WITH CONSTRAINTS
Authors: Boyle Phelim , Tian Weidong
Published: June 2007

The traditional portfolio selection problem concerns an agent whose objective is to maximize the expected utility of terminal wealth over some horizon. This basic problem can be modified by adding constraints. In this paper we investigate the portfolio selection problem for an investor who desires to outperform some benchmark index with a certain confidence level. The benchmark is chosen to reflect some particular investment objective and it can be either deterministic or stochastic. The optimal strategy for this class of problems can lead to nonconvex constraints raising issues of existence and uniqueness. We solve this optimal portfolio selection problem and investigate the procedure for both deterministic and stochastic benchmarks.
A STATE‐SPACE PARTITIONING METHOD FOR PRICING HIGH‐DIMENSIONAL AMERICAN‐STYLE OPTIONS
Authors: Jin Xing , Tan Hwee Huat , Sun Junhua
Published: June 2007

The pricing of American‐style options by simulation‐based methods is an important but difficult task primarily due to the feature of early exercise, particularly for high‐dimensional derivatives. In this paper, a bundling method based on quasi‐Monte Carlo sequences is proposed to price high‐dimensional American‐style options. The proposed method substantially extends Tilley's bundling algorithm to higher‐dimensional situations. By using low‐discrepancy points, this approach partitions the state space and forms bundles. A dynamic programming algorithm is then applied to the bundles to estimate the continuation value of an American‐style option. A convergence proof of the algorithm is provided. A variety of examples with up to 15 dimensions are investigated numerically and the algorithm is able to produce computationally efficient results with good accuracy.
MEASURES OF TECHNICAL CHANGE AND STRUCTURAL CHANGE IN SERVICES IN THE USA: WAS THERE A RESURGENCE OF PRODUCTIVITY GROWTH IN SERVICES?
Authors: Wolff Edward N.
Published: June 2007

Traditional measures of productivity growth show very low gains made by most service industries since 1980s in the USA. However, other indices of ‘technological activity’, such as computerization, education, and occupational change, show that service industries were more technologically active than goods producers over this period. I first distinguish among three types of services: standardized like communications, customized like recreation, and hybrid like retailing. Using output, employment, and capital stock data for 43 industries over 1960–2000, I find that in terms of productivity standardized services behave like goods producers, customized services have had virtually zero productivity growth, and hybrid services fall in between. These results show up in historical data as well as in econometric analysis.
‘BAUMOL'S DISEASE’, PRODUCTION EXTERNALITIES AND PRODUCTIVITY EFFECTS OF INTERSECTORAL TRANSFERS
Authors: De Vincenti Claudio
Published: June 2007

This paper presents a model that introduces in an unbalanced growth framework à la Baumol the hypothesis of an endogenous productivity growth due to a positive externality of the service sector on manufacturing productivity and a learning‐by‐doing process inside both sectors. The model shows that a policy aimed at keeping the ratio between outputs in the two sectors constant in real terms may improve the aggregate productivity performance of the economy, depending on the parameters' values. Then the model derives the dynamics of the intersectoral transfer which is necessary to keep the ratio between outputs constant, and verifies that the amount of the transfer turns out to be always lower than the output of the manufacturing sector, and only asymptotically approaches it.
Single nucleotide sequence analysis: a cost‐ and time‐effective protocol for the analysis of microsatellite‐ and indel‐rich chloroplast DNA regions
Authors: GUICKING DANIELA , KRÖGER‐KILIAN TIM , WEISING KURT , BLATTNER FRANK R.
Published: June 2007

We present a simple method to screen for DNA sequence variation in microsatellite‐ and indel‐rich regions of the chloroplast genome. The single nucleotide sequence (SNS) analysis provides a trade‐off between the time‐ and cost‐effective, but less informative and homoplasy‐sensitive electrophoretic detection of microsatellite and indel size variation on the one hand, and more costly, but also more accurate methods like DNA sequencing on the other. The principle of the SNS method is to sequence one instead of all four nucleotides of a target region amplified by polymerase chain reaction. By careful selection of the respective nucleotide, almost the same amount of information can be retrieved from these partial sequences as could be from complete sequences; however, only a third to a fourth of the money and time resources are needed.
Tube structures of probable microbial origin in the Neoarchean Carawine Dolomite, Hamersley Basin, Western Australia
Authors: MURPHY M. A. , SUMNER D. Y.
Published: June 2007

The ~2.63 Ga Carawine Dolomite, Hamersley Basin, Western Australia, preserves tube structures of probable microbial origin that formed in a low energy environment. The tubes are 0.4–1.8 cm in diameter and at least 10–16 cm long in outcrop. The tubes are defined by dark, 45‐µm‐thick dolomicritic walls, whereas the tube fill and host rock are composed of 30 µm, cloudy dolomite crystals and rare 170‐ to 425‐µm‐wide, dark well‐sorted clasts. Closely spaced, rarely discontinuous laminae coat the insides of tubes; less closely spaced, peaked, discontinuous laminae coat the outsides of tubes. The laminae on the outsides of tubes are often intercalated with mammilate structures. The presence of probable microbial coatings on both the insides and the outsides of the tube walls requires that the tubes formed above the sediment–water interface. These tube structures probably formed during gas‐charged fluid escape, similar to tubes observed in ancient and modern hydrocarbon seeps and cylindrical water transfer structures in sandstones. The laminae that coat the tubes have very similar geometries to modern biofilms that form in both turbulent and laminar flow, and their geometries probably reflect flow conditions during the fluid escape. The identification of these structures suggests that the preserved interaction between fluid escape and microbial growth in carbonates may be more common than previously thought.
Associations between Outpatient and Inpatient Service Use among Persons with HIV Infection: A Positive or Negative Relationship?
Authors: Fleishman John A. , Moore Richard D. , Conviser Richard , Lawrence Perrin B. , Korthuis P. Todd , Gebo Kelly A.
Published: June 2007

Objective. To examine the prospective association between frequency of outpatient visits and subsequent inpatient admissions.

Data Sources. Medical record data on 13,942 patients with HIV infection seen in 10 HIV speciality care sites across the United States.

Study Design. This observational study followed a cohort of HIV‐infected patients who were in care in the first half of 2001. Numbers of inpatient admissions and outpatient visits were calculated for each patient for each 3‐month period, from 2001 through 2004.

Analysis. Negative binomial and logistic regression analyses using random‐effects models examined the effects of inpatient admissions and outpatient visits in the previous period on inpatient and outpatient service utilization, controlling for background characteristics and HIV disease stage.

Results. For 3‐month periods, between 5 and 9 percent of patients had an inpatient admission. The linear association between number of outpatient visits and any inpatient admission in the subsequent period was positive (adjusted odds ratio=1.05; 95 percent confidence interval [CI]=1.04, 1.06). However, patients with zero prior outpatient visits had significantly greater admission rates than those with one prior visit. Hospitalization rates were also higher among those with a prior hospitalization and those with more advanced HIV disease.

Conclusions. These results suggest a J‐shaped relationship between outpatient use and inpatient use among persons with HIV disease. Those in worse health have greater utilization of both inpatient and outpatient care. However, having no outpatient visits may also increase the likelihood of subsequent hospitalization. Although outpatient care cannot be justified as a cost‐saving mechanism, maintaining regular clinical monitoring of patients is important.