bluuebunny/crossref_metadata_2025 huggingface dataset:
Difference in sleep regulation between morning and evening circadian types as indexed by antero‐posterior analyses of the sleep EEG
Authors: Mongrain Valérie , Carrier Julie , Dumont Marie
Published: January 2006

Circadian types classify individuals according to their preferred timing for activity and sleep, morning and evening types showing, respectively, early or late preferences. This characteristic has been associated with corresponding differences in circadian sleep propensity. In this study, quantitative analysis of the sleep EEG in antero‐posterior derivations was used to test the hypothesis that morning and evening types differ not only in the circadian aspect of sleep regulation but also in the homeostatic aspect. Morning types and evening types (six men and six women per group, aged 19–34 years) were selected using the Morningness–Eveningness Questionnaire. They were studied by polysomnography according to their preferred sleep schedule. Spectral activity in four midline derivations (Fz, Cz, Pz, Oz) was calculated separately in nonrapid eye movement (NREM) sleep and in rapid eye movement (REM) sleep. In NREM sleep, morning types showed a steeper decrease of slow‐wave activity (SWA; 1–5 Hz) per sleep cycle in the fronto‐central derivations and a steeper increase in 13–14 Hz activity in the parieto‐occipital derivations than did evening types. Nonlinear regression analysis revealed that the exponential decay rate of relative values of SWA in NREM sleep was faster in morning than evening types, in the frontal derivation. In REM sleep, morning types showed a steeper decrease of high sigma (14–16 Hz) and beta (16–24 Hz) activities across the night in centro‐parietal derivations than did evening types. These results show for the first time a clear difference between morning types and evening types in homeostatic sleep regulation.
Prenatal stress: opposite effects on anxiety and hypothalamic expression of vasopressin and corticotropin‐releasing hormone in rats selectively bred for high and low anxiety
Authors: Bosch Oliver J. , Krömer Simone A. , Neumann Inga D.
Published: January 2006

We studied the mechanisms of genetic–early environmental interactions to modulate adult stress‐coping and tested the hypothesis that prenatal stress (PS) can differentially alter the consequences of a genetic predisposition to either hyper‐ or hypo‐anxiety. Exposure of male Wistar rats, bred for high (HAB) or low (LAB) anxiety‐related behaviour, to PS between pregnancy days 4 and 18 resulted in opposite effects on anxiety in adulthood, i.e. HAB rats became less and LAB rats became more anxious compared with their unstressed controls (plus‐maze and holeboard). The high anxiety of HAB controls was accompanied by elevated expression of vasopressin and corticotropin‐releasing hormone (CRH) mRNA within the hypothalamic paraventricular nucleus compared with LAB rats. PS reduced CRH mRNA expression in HAB rats but increased vasopressin mRNA expression in LAB rats, which may explain the opposite effects of PS on adult emotionality. Differential effects of PS were also found with respect to hypothalamo‐pituitary‐adrenal axis reactivity; the hypothalamo‐pituitary‐adrenal hyper‐response in virgin female HAB controls became attenuated after PS, without affecting plasma corticosterone concentrations in LAB rats. Differences in maternal plasma corticosterone measured between pregnancy days 6 and 14 of HAB and LAB dams or differential effects of PS on maternal behaviour can be excluded. In conclusion, exposure of rats with genetically determined high or low emotionality to PS mitigates the extremes in behavioural and neuroendocrine stress‐coping, thus allowing adequate and similar behavioural responses to potentially dangerous stimuli in adulthood. Differential effects of PS on the activity of the brain vasopressin and CRH systems might represent possible underlying molecular mechanisms.
Sensorineural hearing loss in insulin‐like growth factor I‐null mice: a new model of human deafness
Authors: Cediel R. , Riquelme R. , Contreras J. , Díaz A. , Varela‐Nieto I.
Published: January 2006

It has been reported that mutations in the gene encoding human insulin‐like growth factor‐I (IGF‐I) cause syndromic hearing loss. To study the precise role of IGF‐I in auditory function and to hypothesize the possible morphological and electrophysiological changes that may occur in the human inner ear, we have analysed the auditory brainstem response in a mouse model of IGF‐I deficiency. We show here that homozygous Igf‐1–/– mice present an all‐frequency involved bilateral sensorineural hearing loss. Igf‐1–/– mice also present a delayed response to acoustic stimuli; this increases along the auditory pathway, indicating a contribution of the central nervous system to the hearing loss in Igf‐1–/– mice. These results support the use of the Igf‐1–/– mouse as a new model for the study of human syndromic deafness.
The vomeronasal organ is required for the expression of lordosis behaviour, but not sex discrimination in female mice
Authors: Keller Matthieu , Pierman Sylvie , Douhard Quentin , Baum Michael J. , Bakker Julie
Published: January 2006

The role of the vomeronasal organ (VNO) in mediating neuroendocrine responses in female mice is well known; however, whether the VNO is equally important for sex discrimination is more controversial as evidence exists for a role of the main olfactory system in mate recognition. Therefore, we studied the effect of VNO removal (VNOx) on the ability of female mice to discriminate between volatile and non‐volatile odours of conspecifics of the two sexes and in different endocrine states using Y‐maze tests. VNOx female mice were able to reliably distinguish between male and female or male and gonadectomized (gdx) male volatile odours. However, when subjects had to discriminate between male and female or gdx male non‐volatile odours, VNOx females were no longer able to discriminate between sex or different endocrine status. These results thus show that the VNO is primarily involved in the detection and processing of non‐volatile odours, and that female mice can use volatile odours detected and processed by the main olfactory system for mate recognition. However, VNO inputs are needed to promote contact with the male, including facilitation of lordosis responses to his mounts. A single subcutaneous injection with gonadotropin‐releasing hormone (GnRH) partially reversed the deficit in lordosis behaviour observed in VNOx females suggesting that VNO inputs may reach hypothalamic GnRH neurons to influence the display of sexual behaviour.
Measurement of microvolt T‐wave alternans, a new arrhythmic risk stratification test, in Type 2 diabetic patients without clinical cardiovascular disease
Authors: Molon G. , Targher G. , Costa A. , Bertolini L. , Barbieri E. , Zenari L.
Published: January 2006

Aims  Patients with a positive microvolt T‐wave alternans (TWA) are at increased risk of ventricular arrhythmias and sudden cardiac death. Although Type 2 diabetes is associated with an increased risk of these events, there is a dearth of available data on measurements of TWA in people with Type 2 diabetes.

Methods  We studied 43 Type 2 diabetic volunteers who were free of diagnosed cardiovascular disease (CVD). Microvolt TWA analysis was performed non‐invasively using the CH 2000 system during submaximal exercise with the patients sitting on a bicycle ergometer.

Results  TWA analysis was positive in 9 (21%) patients, negative in 32 (74.4%) and indeterminate in 2 (4.6%) subjects. TWA positive patients had significantly higher HbA1c levels than those with TWA negativity (8.1 ± 0.9 vs. 7.2 ± 0.8%, P < 0.01). Age, sex, BMI, blood pressure, lipids, 24‐h heart rate variability, QTc interval duration, smoking history, diabetes duration and treatment, and microvascular complication status did not differ between the groups. In regression logistic analysis, HbA1c was the only significant predictor of TWA positivity (odds ratio 5.7, 95% CI 1.3–26, P = 0.023) after controlling for potential confounders.

Conclusions  These results suggest that in Type 2 diabetic patients without clinically manifest CVD, TWA positivity is common (approximately 20%) and is closely correlated with glycaemic control.
Integration of Multidimensional Self‐Concept and Core Personality Constructs: Construct Validation and Relations to Well‐Being and Achievement
Authors: Marsh Herbert W. , Trautwein Ulrich , Lüdtke Oliver , Köller Olaf , Baumert Jürgen
Published: January 2006

Relations between multiple dimensions of self‐concept, personality (Big Five), well‐being, and academic outcomes (school grades, test scores, coursework selection) for a large (N=4,475) sample of German adolescents support the construct validity of a well‐defined, multidimensional set of self‐concept factors in relation to personality factors, and vice versa. Confirmatory factor analysis of a German adaptation of the Self Description Questionnaire III demonstrated 17 a priori, reasonably independent self‐concept factors (M correlation=.14; SD=.17) that had a highly differentiated pattern of relations with the personality factors and academic outcomes. Consistent with theory and previous research, math and verbal self‐concepts were negatively related to each other, and this extreme domain specificity was reflected in the systematic and substantial relations with academic criteria measures. Self‐esteem, Big Five, and well‐being factors explained only small amounts of variance in academic outcomes and support for their incremental validity after controlling for specific self‐concept factors was weak.
nef gene sequence variation among HIV‐1‐infected African children*
Authors: Chakraborty R , Reinis M , Rostron T , Philpott S , Dong T , D'Agostino A , Musoke R , de Silva E , Stumpf M , Weiser B , Burger H , Rowland‐Jones SL
Published: January 2006

Background

There are few data on African children infected with nonclade B HIV‐1 in endemic settings, which limits generalizations about pathogenesis and progression. Genotypic and phenotypic variations in host immunogenetics and HIV‐1 negative factor (nef) accessory protein may influence disease progression and have frequently been characterized in subjects infected with clade B HIV‐1.

Methods

In this descriptive study, we report nef gene sequence variation and host genetic polymorphisms in 32 Kenyan children, including 12 slow progressors.

Results

Phylogenetic analysis identified HIV‐1 clades A, C and D and a recombinant A/D subtype. Grossly defective nef genes or significant changes from relevant clade reference sequences were not identified in children with delayed disease progression.

Conclusions

nef sequence variations may not be common in perinatally infected African children. Further studies are warranted in HIV‐1‐infected subjects in settings where infection is endemic.
Depression and neurocognitive performance in individuals with HIV/AIDS: 2‐year follow‐up
Authors: Gibbie T , Mijch A , Ellen S , Hoy J , Hutchison C , Wright E , Chua P , Judd F
Published: January 2006

Objectives

The aims of this study were to follow a cohort of HIV‐infected individuals for 2 years to assess changes in depression and neuropsychological performance over time, to explore the relationship between depression, HIV illness and neuropsychological performance, and to examine the natural history of the effect of highly active antiretroviral therapy (HAART) on depression and neurocognitive performance.

Methods

HIV‐seropositive out‐patients were assessed at baseline and at 2‐year follow‐up. At each assessment, patients were assessed for depression [using the Beck Depression Inventory (BDI) and Structured Clinical Interview (SCID‐CV)] and completed a battery of neuropsychological tests including the Cambridge Neuropsychological Test Automated Battery (CANTAB) and the Hopkins HIV Dementia Scale (HDS).

Results

At baseline, 34.8% scored ≥14 on the BDI [≥14 suggests depressive symptoms (DS)]. The SCID‐CV revealed that 27% of participants met the criteria for current mood disorder. Seven per cent of the participants' scores on the HDS indicated HIV‐associated cognitive changes. Eighty participants were re‐tested at 2‐year follow‐up and were split into two groups based on BDI scores at baseline. CANTAB results revealed that the cohort were significantly impaired on nine of 10 measures compared with age‐matched normative data. Neurocognitive performance significantly improved for participants with no DS at baseline, whereas participants with DS at baseline did not show as much improvement. Multivariate analysis revealed that 40% of the change in cognitive performance was attributable to the variables age, AIDS and HAART regimen.

Conclusion

These results suggest a significant decline in depression scores and an improvement in several neurocognitive domains over time, with a relationship between HIV illness, HAART, symptoms of depression and neurocognitive performance.
Analysis of genotypic and phenotypic clinical cut‐off levels for ritonavir‐boosted saquinavir
Authors: Hill A , Walmsley S , Clotet B , Molto J
Published: January 2006

There is a need for new, clinically relevant interpretation algorithms for genotypic and phenotypic resistance for ritonavir‐boosted saquinavir (SQV/r) at the current approved dosage [1000/100 mg twice a day (bid)]. Clinical cut‐off levels, which correlate baseline measures of resistance with HIV RNA responses in large cohorts or clinical trials, are the ideal reference for developing such algorithms. Cut‐off levels previously developed for unboosted saquinavir may no longer apply, as the plasma drug levels with SQV/r are significantly higher and may be able partially to overcome protease inhibitor‐resistant HIV. Clinical cut‐off levels for SQV/r, assessed in several cohort studies and clinical trials, also suggest that multiple genotypic mutations are required for complete loss of virological response. For phenotypic analysis of resistance, saquinavir cut‐off levels 10–11‐fold higher than the wild‐type IC50 have best distinguished responders from non‐responders in cohort studies. Using Virtual Phenotype, a 12.3‐fold upper cut‐off level was determined from analysis of large cohort databases. These genotypic and phenotypic algorithms need to be validated in larger prospective studies.
Characterization of nelfinavir binding to plasma proteins and the lack of drug displacement interactions
Authors: Motoya T , Thevanayagam LN , Blaschke TF , Au S , Stone JA , Jayewardene AL , Chi J , Aweeka FT
Published: January 2006

Objectives

To determine the characteristics of the binding of nelfinavir and active M8 to α1‐acid glycoprotein (AAG) and human serum albumin (HSA), and to examine the displacement effects of drugs binding extensively to AAG (ritonavir and saquinavir) or to HSA (salicylic acid and valproic acid).

Methods

Free drugs were separated by equilibrium dialysis after incubation with human plasma or purified plasma proteins and after co‐incubation with potential displacers. Association constants were estimated from double‐reciprocal plots of the data.

Results

Nelfinavir and M8 free fractions [fractions of unbound drug (fus)] were 0.42±0.08% (mean±standard deviation) and 0.64±0.07%, respectively. For the two analytes, respectively, association constants were 7.25 × 107/m and 3.33 × 107/m for AAG and 1.11 × 106/m and 7.92 × 105/m for HSA. Nelfinavir fu in an AAG solution was significantly (P<0.01) increased by the addition of ritonavir or saquinavir, whereas it was unaltered by addition of these drugs to whole plasma. Similarly, fu in an HSA solution was significantly increased (P<0.01) by the addition of salicylic acid or valproic acid, whereas there was no difference in the free fraction in plasma.

Conclusions

The affinity of nelfinavir for human plasma proteins was higher than that of M8, and both nelfinavir and M8 showed higher affinity to AAG than to HSA. The free fraction of nelfinavir was not affected by drugs that bind extensively to AAG or albumin when these drugs were added to whole plasma in combination, suggesting a compensatory effect of alternate binding proteins.
Isolation and characterization of microsatellite DNA markers in the grass Poa alpina L.
Authors: MAURER K. , GAUTSCHI B. , WEYAND A. , STÖCKLIN J. , FISCHER M.
Published: January 2006

The important fodder grass Poa alpina L. occurs at several ploidy levels with common aneuploidy. We isolated and characterized five polymorphic microsatellite markers for the study of molecular genetic variation of this species. As first examples of the value of the developed markers for population genetic analyses, we show that plants with more chromosomes have more microsatellite bands and that isolation by distance plays a small role in shaping microsatellite diversity of P. alpina in the Swiss Alps.
Development and characterization of microsatellite markers in a clonal plant, Dioscorea japonica Thunb.
Authors: MIZUKI INOUE , TANI NAOKI , ISHIDA KIYOSHI , TSUMURA YOSHIHIKO
Published: January 2006

We developed 10 microsatellite loci from genomic DNA of a dioecious clonal plant, Dioscorea japonica. Out of 384 clones, 148 contained microsatellite repeats. Polymerase chain reaction primer pairs were designed for 95 of these clones from their sequence data, of which, 10 pairs produced successful amplification. Thirty‐eight individuals were genotyped for allelic diversity. We detected three to nine alleles per locus, and the expected heterozygosity ranged from 0.461 to 0.851.
Isolation and characterization of microsatellite markers from Sarcocystis neurona, a causative agent of equine protozoal myeloencephalitis
Authors: ASMUNDSSON INGRID M. , ROSENTHAL BENJAMIN M.
Published: January 2006

The population genetics and systematics of coccidian parasites of the genus Sarcocystis remain poorly defined, notwithstanding their relevency to veterinary and human health. Despite opportunities for sexual recombination, nonrecombinant parasite clones characterized by distinct transmission and pathogenesis traits persist in related parasites (i.e. Toxoplasma gondii). In order to determine whether this may be generally true for parasitic coccidia, and to address evolutionary and taxonomic problems within the genus Sarcocystis, we isolated 12 polymorphic microsatellite markers (four to 14 alleles) for Sarcocystis neurona, the major causative agent of equine protozoal myeloencephalitis (EPM).
Isolation of fungal DNA from plant tissues and removal of DNA amplification inhibitors
Authors: MALVICK DEAN K. , GRUNDEN ERIC
Published: January 2006

Specific primers and the polymerase chain reaction (PCR) are increasingly used for detection of fungi in plants. Detection depends on isolation of DNA that is free of compounds that inhibit amplification. We report on the significance of inhibition in soybean stems with a focus on studies of the vascular fungal pathogen Phialophora gregata. A simple DNA extraction procedure based on a FastDNA® kit is described that allows consistent detection of fungi in soybean stems using PCR. The addition of polyvinylpyrrolidone and supplemental DNA purification steps overcame inhibition in over 90% of samples. These methods should also facilitate studies with other plant and fungal species.
Isolation and characterization of six polymorphic microsatellite markers in the freshwater turtle Mauremys rivulata (Testudines: Geoemydidae)
Authors: MANTZIOU G. , ANTONIOU A. , POULAKAKIS N. , GOULIELMOS G. , TSIGENOPOULOS C. S. , PINOU T. , MYLONAS M.
Published: January 2006

Six polymorphic microsatellite loci containing dinucleotide repeats were developed for the freshwater turtle Mauremys rivulata. The number of alleles ranged from five to 18. The observed and expected heterozygosities ranged from 0.19 to 0.79 and 0.46 to 0.90, respectively. These markers may serve as a valuable tool for population genetics analyses and provide information on the evolutionary history of the species.
Isolation and characterization of polymorphic microsatellite loci in the plural cooperatively breeding superb starling, Lamprotornis superbus
Authors: RUBENSTEIN DUSTIN R.
Published: January 2006

Superb starlings (Lamprotornis superbus) are separate nesting plural cooperative breeders endemic to East Africa that show high levels of reproductive conflict and low reproductive skew. I isolated 31 polymorphic microsatellite loci from the superb starling genome and characterized them in approximately 31 individuals. The numbers of alleles per locus ranged from two to 16 and observed heterozygosities ranged from 0.03 to 0.88. Many of these loci amplified in other passerine species including the European starling, Sturnus vulgaris, and a variety of other starlings and mockingbirds.
Type I microsatellite markers from Atlantic salmon (Salmo salar) expressed sequence tags
Authors: NG SIEMON H. S. , CHANG ALAN , BROWN GORDON D. , KOOP BEN F. , DAVIDSON WILLIAM S.
Published: January 2006

The detection of simple sequence repeats (SSRs) within expressed sequence tags (ESTs) connects potential microsatellite markers with specific genes, generating Type I markers. Using an in silico approach, we identified 1975 SSRs from the Genome Research on Atlantic Salmon Project EST database. We designed primers to amplify 158 SSRs, of which 65 amplified 76 loci (including 11 duplicated loci). Sixty‐one of the 76 loci were variable in 24 Atlantic salmon from seven populations, and 96% of these markers also amplify DNA from other salmonids. Functions for 16 of the SSR associated ESTs have been determined, confirming them as Type I markers.
Development of microsatellite markers in Abies nordmanniana (Stev.) Spach and cross‐species amplification in the Abies genus
Authors: HANSEN O. K. , VENDRAMIN G. G. , SEBASTIANI F. , EDWARDS K. J.
Published: January 2006

Abies nordmanniana (Stev.) Spach is a widely grown Christmas tree in Denmark, from where it is exported to most of Europe. An ongoing breeding programme is taking place, and as a tool for that, we report the development of five polymorphic nuclear microsatellite markers. To investigate the potential for transferring the markers to other species in the Abies genus, polymerase chain reaction amplification was tested in 19 other species. In general, amplification occurred in a very high proportion of the tested species.
Isolation and characterization of microsatellite DNA markers from mangrove crab, Scylla paramamosain
Authors: TAKANO MASATSUGU , BARINOVA ANNA , SUGAYA TAKUMA , OBATA YASUHIRO , WATANABE TOMOHISA , IKEDA MINORU , TANIGUCHI NOBUHIKO
Published: January 2006

The first five variable microsatellite DNA loci for mangrove crab, Scylla paramanosain, were developed. Allelic variation and other characteristics at these loci were examined in this species captured at the Urado Bay, Japan. The number of alleles per locus ranged from 24 to 44. The expected heterozygosity across loci ranged from 0.900 to 0.999 and probability of identity (PI) ranged from 2.8 × 10−3 to 1.7 × 10−2. Therefore, these microsatellite markers could be useful for estimating effect of stock enhancement release and population genetic structure of mangrove crab.
Isolation and characterization of microsatellite loci in Santalum austrocaledonicum, Santalaceae
Authors: BOTTIN L. , VAILLANT A. , SIRE P. , CARDI C. , BOUVET J. M.
Published: January 2006

The forest tree Santalum austrocaledonicum is endemic to the archipelagos of New Caledonia and Vanuatu, and is threatened by the reduction of the populations due to exploitation. In order to investigate the genetic diversity and structure of this species, we developed eight pairs of primers for nuclear microsatellites. These loci were polymorphic in all the populations, with a mean of three to 33 alleles per locus.
Isolation and characterization of twelve polymorphic microsatellite markers in bottlenose dolphins (Tursiops truncatus)
Authors: ROSEL P. E. , FORGETTA V. , DEWAR K.
Published: January 2006

We developed polymerase chain reaction primers for 12 dinucleotide microsatellite loci in the bottlenose dolphin, Tursiops truncatus. Seven markers were obtained after hybridization screening, and five following random genome sequencing. Orthologous positions were computed for nine markers on the bovine genome and for seven on the human genome. The markers are distributed across chromosomes and found in different types of DNA regions. All 12 loci are polymorphic for Tursiops. Five loci were also polymorphic in the related species Stenella frontalis and the more distantly related river dolphin, Inia geoffrensis, indicating these markers will be informative across the Delphinidae and other cetacean taxa.
DNA microsatellites in Acanthochromis polyacanthus
Authors: MILLER‐SIMS VANESSA , DELANEY MARTHA , ATEMA JELLE , KINGSFORD MICHAEL , GERLACH GABRIELE
Published: January 2006

To determine genetic substructuring in populations of the spiny damselfish Acanthochromis polyacanthus among different reefs of the Great Barrier Reef, Australia, we characterized six polymorphic microsatellite loci.
Estimation and adjustment of microsatellite null alleles in nonequilibrium populations
Authors: VAN OOSTERHOUT C. , WEETMAN D. , HUTCHINSON W. F.
Published: January 2006

Nonamplified (null) alleles are a common feature of microsatellite genotyping and can bias estimates of allele and genotype frequencies, thereby hindering population genetic analyses. The frequency of microsatellite null alleles in diploid populations can be estimated for populations that are in Hardy–Weinberg equilibrium. However, many microsatellite data sets are from nonequilibrium populations, often with known inbreeding coefficients (F) or fixation indices (FIS or FST). Here, we propose a novel null allele estimator that can be used to estimate the null allele frequency and adjust visible allele frequencies in populations for which independent estimates of F, FIS or FST are available. The algorithm is currently available as an Excel macro that can be downloaded at no cost from http://www.microchecker.hull.ac.uk/ and will be incorporated into the software micro‐checker.
Characterization of eight microsatellite loci in the maize stalk borer Busseola fusca Fuller, 1901 (Lepidoptera: Noctuidae)
Authors: FAURE NATHALIE , SILVAIN JEAN‐FRANÇOIS
Published: January 2006

The noctuid stem borer Busseola fusca occurs throughout sub‐Saharan Africa, where it is considered as a major pest of corn and sorghum. To understand B. fusca phylogeography, we isolated and characterized eight microsatellite loci in this species. We investigated these loci for polymorphism on a subset sample of individuals from different geographic populations. All loci were polymorphic, showing between four and 10 alleles. Cross‐species amplification of four of these loci was tested on 11 other noctuid species.
Isolation and characterization of microsatellite DNA loci in sea bass, Lates calcarifer Bloch
Authors: SIM M. P. , OTHMAN A. S.
Published: January 2006

Polymerase chain reaction (PCR)‐based isolation of microsatellite arrays (PIMA) technique was used to isolate seven polymorphic microsatellite loci in sea bass, Lates calcarifer Bloch. A total of 62 samples of wild and cultivated sea bass collected from a few populations within Peninsular Malaysia were used in the study. For seven polymorphic loci, the number of alleles ranged from four to nine and locus heterozygosities ranged from 0.710 to 1.000. The loci will be useful for studying population structure, genetic variability of wild and hatchery stocks of L. calcarifer and broodstock management purposes.
Isolation and characterization of microsatellite loci from the Australasian sea snake, Aipysurus laevis
Authors: LUKOSCHEK VIMOKSALEHI , WAYCOTT MICHELLE , DUNSHEA GLENN
Published: January 2006

We developed 13 microsatellite loci for the olive sea snake, Aipysurus laevis, using both enriched and unenriched genomic DNA libraries. Eleven codominant loci, that reliably amplified, were used to screen 32 individuals across the geographic range of A. laevis. Four loci had four or more alleles (maximum 12), whereas the other seven had either two or three. All but one locus was in Hardy–Weinberg equilibrium. These loci will provide useful markers to investigate population genetic structure for the olive sea snake.
Characterization of eight polymorphic microsatellites in endangered willow Salix hukaoana
Authors: KIKUCHI S. , SUZUKI W. , BAN N. , KANAZASHI A. , YOSHIMARU H.
Published: January 2006

Salix hukaoana is an endangered riparian tree that is found and known only in several isolated sites in eastern Japan, and that has been suffering from the loss and fragmentation of its habitat. To investigate the genetic variation and structures of this willow in these sites, eight polymorphic microsatellites with three to eight alleles were characterized. Cross‐species amplification was successful for many of the loci using the congeners Salix sachalinensis and Chosenia arbutifolia. This set of microsatellites will be useful for the study of the spatial genetic structures of S. hukaoana and other coexisting willows suffering from habitat fragmentation in riparian forests.
Ten new highly polymorphic microsatellite loci in the blood clam Scapharca broughtonii
Authors: AN H. Y. , PARK J. Y.
Published: January 2006

Ten novel microsatellite loci were isolated from blood clam Scapharca broughtonii, and the polymorphisms were examined to estimate genetic variability. The genetic variabilities varied depending on the locus. The number of alleles ranged from 11 to 23, and the observed and expected heterozygosities ranged from 0.63 to 0.93 and 0.66 to 0.95, respectively. Four loci showed significant Hardy–Weinberg disequilibrium at P < 0.05 level. The high variabilities revealed in this study suggest that microsatellites should prove useful for various genetic investigations.
Polymorphic microsatellite loci isolated from the great scallop, Pecten maximus (Bivalvia: Pectinidae)
Authors: WATTS PHILLIP C. , MALLANAPHY PAUL J. , MCCARTHY CHRIS , BEUKERS‐STEWART BRYCE D. , MOSLEY MATTHEW W. J. , BRAND ANDREW R. , SACCHERI ILIK J.
Published: January 2006

We isolated and characterized nine polymorphic microsatellite loci from the great scallop (Pecten maximus) as part of an attempt to better understand the population–genetic structure of this species. Levels of genetic diversity were assessed in 32 scallops collected from the coastal waters of Port Erin Bay, Isle of Man. The number of alleles ranged from two to 29 and observed and expected heterozygosities varied between 0.031 to 0.906 and 0.062 to 0.973, respectively. Two loci showed significant (P < 0.05) heterozygote deficits, likely because of null (nonamplifying) alleles; one pair of loci was in linkage disequilibrium.
A nondestructive, rapid, reliable and inexpensive method to sample, store and extract high‐quality DNA from fish body mucus and buccal cells
Authors: LIVIA LUCENTINI , ANTONELLA PALOMBA , HOVIRAG LANCIONI , MAURO NATALI , PANARA FAUSTO
Published: January 2006

A rapid, nondestructive, reproducible and cheap DNA extraction method from body mucus and buccal cells of northern pike and brown trout is described. Buccal cells and body mucus were sampled on FTA Cards; the captured DNA was used directly for microsatellite and polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) analyses. A complete concordance with control DNA was found. The genotyping error rate for microsatellite ranged from 1.9% to 3.3% for the northern pike and brown trout, respectively. This methodology, using for the first time these materials as a fish DNA source, combines speed of sampling and processing, with a twofold to a threefold time and costs saving.
Isolation and characterization of di‐ and tetranucleotide microsatellite loci in the yellow‐spotted night lizard Lepidophyma flavimaculatum (Squamata: Xantusiidae)
Authors: SINCLAIR ELIZABETH A. , SCHOLL REBECCA , BEZY ROBERT L. , CRANDALL KEITH A. , SITES JACK W.
Published: January 2006

We report the development of 17 di‐ and tetranucleotide microsatellite markers in the Yellow‐Spotted Night Lizard Lepidophyma flavimaculatum. Levels of heterozygosity ranged from 0 to 100%. Several loci also amplify in other Lepidophyma species and several species of the sister genus Xantusia. High levels of variation at some loci indicate that they will be useful for parentage assessment and population genetic studies, whereas the 15 loci that amplify across multiple Lepidophyma species suggest these will be useful in determining the origin of parthenogenetic populations.
Microsatellite markers for European Daphnia
Authors: BREDE N. , THIELSCH A. , SANDROCK C. , SPAAK P. , KELLER B. , STREIT B. , SCHWENK K.
Published: January 2006

We present 32 polymorphic microsatellite markers for species of the European Daphnia longispina group: D. galeata, D. hyalina, D. rosea, D. cucullata and D. curvirostris. Microsatellite markers were either isolated from genomic libraries or optimized based on previously published sequence information of sister taxa. Cross‐species tests revealed that all but one of the polymorphic markers are applicable to more than one species, which allows intra‐ and interspecific genetic studies on, i.e. population structure, hybridization events and introgression.
Prebreeding moult, plumage and evidence for a presupplemental moult in the Great Knot Calidris tenuirostris
Authors: BATTLEY PHIL F. , ROGERS DANNY I. , HASSELL CHRIS J.
Published: January 2006

We studied the prebreeding moult and resulting plumage in a long‐distance migrant sandpiper (Scolopacidae), the Great Knot Calidris tenuirostris, on the non‐breeding grounds (northwest Australia), on arrival at the staging grounds after the first migratory flight (eastern China) and on or near the Russian breeding grounds (Russian data from museum specimens). We show that breeding plumage scores and breast blackness were affected not only by the increase in moulted feathers but also in the wearing down of overlaying pale tips of fresh feathers. Birds migrating from Australia and arriving in China had completed or suspended moult, but more moult must occur in Asia as Russian specimens had moulted more of their mantle and scapular feathers. Russian birds had significantly more red feathering on their upperparts than had birds in Australia or those arriving in China. The increase in reddish feathers cannot by accounted for simply by continuation of the prealternate moult. Instead, a third, presupplemental moult must occur, in which red‐marked feathers replace some scapular and especially mantle feathers that were acquired in a prealternate moult only 1–3 months earlier. Great Knot sexes show little size and plumage dimorphism, whereas two other sandpipers that have supplemental plumages (Ruff Philomachus pugnax and Bar‐tailed Godwit Limosa lapponica) are thought to be highly sexually selected. Bidirectional sexual selection may therefore be involved in the evolution of a supplemental plumage in Great Knots.
Adult Brünnich's Guillemots Uria lomvia balance body condition and investment in chick growth
Authors: GASTON ANTHONY J. , HIPFNER J. MARK
Published: January 2006

To investigate the covariation of adult body condition and nestling growth, we weighed adult Brünnich's Guillemots Uria lomvia rearing chicks at Coats Island, Nunavut, Canada, each year between 1988 and 2002. We estimated chick mass at 14 days for a sample of chicks reared in the same years. Adult mass and chick mass at 14 days were highly correlated, suggesting that, as feeding conditions deteriorate, adults compromise by reducing their own body reserves, while at the same time delivering less food to their offspring. We compared the prediction of the least‐squares regression for the Coats Island data with observations made at Digges Island, a much larger colony about 300 km away, where birds are similar in linear body measurements to those at Coats Island and have a similar body mass while incubating. Adult mass at Digges Island averaged 11% less during chick‐rearing than during incubation, compared with only a 5% difference at Coats Island. Mean chick mass at 14 days at Digges Island was lower in all years than was observed for chicks at Coats Island in any year. The observed 14‐day chick masses at Digges Island in two years were close to values predicted by adult mass and somewhat lower in two other years (those when chick growth was slowest). At Digges Island, the distribution of mass for brooding adults was right skewed and suggested a lower threshold at 800–850 g, below which Brünnich's Guillemots terminate breeding. We conclude that the correlation between adult and chick mass represents a dynamic equilibrium in which adults simultaneously adjust their own energy reserves and their delivery rate to the chick. This compromise must be based on behavioural choices made by individual birds and is unlikely to be a passive consequence of fluctuating conditions.
A NEW EARLY DEVONIAN THELODONT FROM CELTIBERIA (SPAIN), WITH A REVISION OF SPANISH THELODONTS
Authors: BOTELLA HÉCTOR , VALENZUELA‐RÍOS JOSÉ I. , CARLS PETER
Published: January 2006

Abstract:  A revision of thelodont scales from the Lower Devonian of the Iberian Chains enables their grouping into two taxa: Turinia pagei and T. nachoi sp. nov. These taxa are clearly distinguishable by morphological and histological features; they also have a different stratigraphic range (T. pagei is restricted to Lochkovian strata, whereas T. nachoi sp. nov. occurs within lower–middle Pragian rocks). The new species is represented by head, transitional (cephalopectoral) and trunk scales.
Knowledge‐Based Risk Assessment Under Uncertainty for Species Invasion
Authors: Sikder Iftikhar U. , Mal‐Sarkar Sanchita , Mal Tarun K.
Published: January 2006

Management of invasive species depends on developing prevention and control strategies through comprehensive risk assessment frameworks that need a thorough analysis of exposure to invasive species. However, accurate exposure analysis of invasive species can be a daunting task because of the inherent uncertainty in invasion processes. Risk assessment of invasive species under uncertainty requires potential integration of expert judgment with empirical information, which often can be incomplete, imprecise, and fragmentary. The representation of knowledge in classical risk models depends on the formulation of a precise probabilistic value or well‐defined joint distribution of unknown parameters. However, expert knowledge and judgments are often represented in value‐laden terms or preference‐ordered criteria. We offer a novel approach to risk assessment by using a dominance‐based rough set approach to account for preference order in the domains of attributes in the set of risk classes. The model is illustrated with an example showing how a knowledge‐centric risk model can be integrated with the dominance‐based principle of rough set to derive minimal covering “if … , then…,” decision rules to reason over a set of possible invasion scenarios. The inconsistency and ambiguity in the data set is modeled using the rough set concept of boundary region adjoining lower and upper approximation of risk classes. Finally, we present an extension of rough set to evidence a theoretic interpretation of risk measures of invasive species in a spatial context. In this approach, the multispecies interactions in an invasion risk are approximated with imprecise probability measures through a combination of spatial neighborhood information of risk estimation in terms of belief and plausibility.
Consumer Phase Risk Assessment for Listeria monocytogenes in Deli Meats
Authors: Yang Hong , Mokhtari Amirhossein , Jaykus Lee‐Ann , Morales Roberta A. , Cates Sheryl C. , Cowen Peter
Published: January 2006

The foodborne disease risk associated with the pathogen Listeria monocytogenes has been the subject of recent efforts in quantitative microbial risk assessment. Building upon one of these efforts undertaken jointly by the U.S. Food and Drug Administration and the U.S. Department of Agriculture (USDA), the purpose of this work was to expand on the consumer phase of the risk assessment to focus on handling practices in the home. One‐dimensional Monte Carlo simulation was used to model variability in growth and cross‐contamination of L. monocytogenes during food storage and preparation of deli meats. Simulations approximated that 0.3% of the servings were contaminated with >104 CFU/g of L. monocytogenes at the time of consumption. The estimated mean risk associated with the consumption of deli meats for the intermediate‐age population was approximately 7 deaths per 1011 servings. Food handling in homes increased the estimated mean mortality by 106‐fold. Of all the home food‐handling practices modeled, inadequate storage, particularly refrigeration temperatures, provided the greatest contribution to increased risk. The impact of cross‐contamination in the home was considerably less. Adherence to USDA Food Safety and Inspection Service recommendations for consumer handling of ready‐to‐eat foods substantially reduces the risk of listeriosis.
Implications of Excessive Precision for Risk Comparisons: Lessons from the Past Four Decades
Authors: Hassenzahl David M.
Published: January 2006

This article reviews five published “second‐order” risk comparisons from the past four decades that implied precise understanding, and hence clear relationships or orderings, of the underlying risks. “Second order” here refers to efforts that extract information from original sources with the goal of relating diverse findings. All five of these publications have frequently been cited in the peer‐reviewed literature and/or in risk regulatory debate in the United States. Each is associated with at least one contemporaneous critique that the findings were excessively precise. None of these critiques suggested that an alternative relationship or ordering of the risks evaluated was more appropriate. Instead, each critique concluded that alternative, contradictory relationships were at least as plausible given data and/or analytical limitations. In one case, the critique led to the withdrawal of the original publication. The original findings have been propagated or used uncritically in subsequent literature, including political support for cost‐effectiveness analysis. In other cases, the critiques have been used to discredit quantitative risk analysis in general, especially in the cases of nuclear power and cost‐benefit analysis. Both of these outcomes are undesirable. Future risk comparisons should avoid excessive precision, include explicit discussion of uncertainty, and differentiate between plausible estimates and expected values.
Reinforcement of Hydroxyapatite Bioceramic by Addition of Ti3SiC2
Authors: Shi Sui Lin , Pan Wei , Fang Ming Hao , Fang Zhen Yi
Published: January 2006

Ti3SiC2/HAp composites with different Ti3SiC2 volume fractions were fabricated by spark plasma sintering (SPS) at 1200°C. The effects of Ti3SiC2 addition on the mechanical properties and microstructures of the composites were investigated. The bending strength and fracture toughness of the composites increased with increasing of Ti3SiC2 content, whereas the Vickers hardness decreased. The bending strength and fracture toughness reached 252±10 MPa and 3.9±0.1 MPa·m1/2, respectively, with the addition of 50 vol% Ti3SiC2. The increases in the mechanical properties were attributed to the matrix strengthening and interactions between cracks and the Ti3SiC2 platelets.
Real‐Time Observation of a Non‐Equilibrium Liquid Condensate Confined at Tensile Crack Tips in Oxide Glasses
Authors: Wondraczek Lothar , Dittmar Anne , Oelgardt Carina , Célarié Fabrice , Ciccotti Matteo , Marlière Christian
Published: January 2006

As crack propagation in oxide materials at low crack velocities is partly determined by chemical corrosion, proper knowledge of the crack tip chemistry is crucial for understanding fracture in these materials. Such knowledge can be obtained only fromin situstudies because the processes that occur in the highly confined environment of the crack tip are very different from those that take place at free surfaces, or that can be tracedpost mortem. We report on the occurrence of a hydrous liquid condensate between the two fracture surfaces in the vicinity of the tip of tensile cracks in silica. Observations are performed in real time by means of atomic force microscopy (AFM) at continuously controlled crack velocities in the regime of stress corrosion. Condensate formation and changes in the extent and the shape are demonstrated for a wide range of macroscopic humidities at different crack speeds. Its liquid character is confirmed by the study of AFM phase‐contrast data. It is believed that this evidence of a nanoscale liquid hydrous phase at the crack tip will provide novel insights into the chemistry of failure of oxide materials.
Neck Formation and Self‐Adjusting Mechanism of Neck Growth of Conducting Powders in Spark Plasma Sintering
Authors: Song Xiaoyan , Liu Xuemei , Zhang Jiuxing
Published: January 2006

By using spherical Cu powders as the conducting sintering material, the microstructures of sintered powder particles at different stages in the process of spark plasma sintering (SPS) have been investigated. Theoretical analyses are proposed to quantify the effects of the pulsed direct current on the neck formation and the neck growth of conducting powders. It is found that there is a considerable inhomogeneous distribution of the temperature increase from the particle‐contacting surface to the center of the particle when the pulsed current passes through. The temperature at the particle‐contacting surface may reach the boiling point of the material, which results in neck formation at relatively low‐sintering temperatures through a process of local melting and rapid solidification. The neck growth depends on the local distribution of the current intensity, which is determined by the competition between the neck cross‐sectional area and the electrical resistivity increasing with the temperature. Accordingly, we propose that the coarsening of necks follows a “self‐adjusting” mechanism, which is likely to be the essential reason for the homogeneous distributions of neck sizes and sizes of fine grains formed in the neck zones during the SPS process.
Growth Mechanisms for SiC–AlN Solid Solution Crystals Prepared by Combustion Synthesis
Authors: Wang Huabin , Northwood Derek O. , Han Jiecai , Du Shanyi
Published: January 2006

AlN–SiC solid solution particles with a variety of morphologies including faceted polyhedrons with or without ledges; hexagonal platelets; hexagonal columns with a hexagonal plate or a pyramidal cap; and interpenetrating cones, have been found in the combustion products of a mixture of Al, Si, and carbon black under a nitrogen pressure of 10 MPa. Combustion temperature (the growth temperature of crystals) is the most important factor controlling the morphology of crystals formed in the combustion product. When temperatures are close to the melting point of the solid solutions, a small driving force for nucleation and long distances of surface migration make nucleation on the basal plane difficult, and thus the solid solution particles tend to grow as platelets. Supersaturation is the second key factor influencing crystal growth. At relatively low temperatures, a low supersaturation at the large pores renders nucleation difficult and the solid solution particles tend to grow as platelets. At relatively low temperatures and high supersaturation, a relatively high driving force for nucleation and short mean distances of surface migration promote the growth of AlN–SiC solid solutions as polyhedrons. The formation of the ledges on the polyhedral particles is attributed to the differences in the evaporation rates and the deposition rates between Al and Si. At relatively low temperatures and an intermediate supersaturation, the solid solution particles grow as prismatic columns. The formation of the prismatic columns with a hexagonal plate, or a pyramidal cap, is attributed to a sudden change of temperature during combustion. A possible growth mechanism for the AlN–SiC solid solution cones is proposed.