bluuebunny/crossref_metadata_2025 huggingface dataset:
The cytoplasmic domain of NrCAM binds to PDZ domains of synapse‐associated proteins SAP90/PSD95 and SAP97
Authors: Dirks Petra , Thomas Uli , Montag Dirk
Published: July 2006

NrCAM, a member of the L1 family of cell adhesion molecules, serves important functions during the development of the nervous system, e.g. in adhesion‐dependent processes such as neurite outgrowth and axonal pathfinding. Complex homo‐ and heterophilic binding and several extracellular ligands of NrCAM have been described, but less is known about intracellular interaction partners. The cytoplasmic carboxy‐terminus of NrCAM contains a typical sequence motif for binding to PDZ domains, making interactions with PDZ domain‐containing scaffolding proteins quite conceivable. In this study, we identified specific interactions of the intracellular domain of NrCAM with class I PDZ domains of the membrane‐associated guanylate kinases SAP90/PSD95 and SAP97. In contrast to NrCAM, the intracellular domains of the other mammalian L1 family molecules, e.g. L1, CHL1 and Neurofascin, did not interact with these PDZ domains. In transfected COS‐7 cells, NrCAM‐mediated recruitment of SAP97 to the plasma membrane was dependent on the PDZ binding motif. We show that NrCAM and SAP97 are colocalized, e.g. within photoreceptor terminals of the mammalian retina. In summary, our results confirm a functional PDZ domain binding motif at the carboxy‐terminus of NrCAM and support potential functions of NrCAM during the assembly of highly organized protein complexes at the cell membrane.
Repeated withdrawal from ethanol spares contextual fear conditioning and spatial learning but impairs negative patterning and induces over‐responding: evidence for effect on frontal cortical but not hippocampal function?
Authors: Borlikova Gilyana G. , Elbers Nicoliene A. , Stephens David N.
Published: July 2006

Repeated exposure of rats to withdrawal from chronic ethanol reduces hippocampal long‐term potentiation and gives rise to epileptiform‐like activity in hippocampus. We investigated whether such withdrawal experience also affects learning in tasks thought to be sensitive to hippocampal damage. Rats fed an ethanol‐containing diet for 24 days with two intermediate 3‐day withdrawal episodes, resulting in intakes of 13–14 g/kg ethanol per day, showed impaired negative patterning discrimination compared with controls and animals that had continuous 24‐day ethanol treatment, but did not differ from these animals in the degree of contextual freezing 24 h after training or in spatial learning in the Barnes maze. Repeatedly withdrawn animals also showed increased numbers of responses in the period immediately before reinforcement became available in an operant task employing a fixed‐interval schedule although overall temporal organization of responding was unimpaired. Thus, in our model of repeated withdrawal from ethanol, previously observed changes in hippocampal function did not manifest at the behavioural level in the tests employed. The deficit seen after repeated withdrawal in the negative patterning discrimination and over‐responding in the fixed‐interval paradigm might be related to the changes in the functioning of the cortex after withdrawal.
The septal EEG suggests a distributed organization of the pacemaker of hippocampal theta in the rat
Authors: Nerad Ludek , McNaughton Neil
Published: July 2006

Individual neurons in the medial septum and diagonal band fire in phase with, and appear to act as a ‘pacemaker’ of, the hippocampal theta rhythm. We investigated the relationships of periodic EEG both among various parts of the septum and with dorsal hippocampal theta recorded concurrently in freely moving rats. Most septal sites showed theta rhythm concurrent with hippocampal theta during locomotion. However, periods with theta at hippocampal but not septal sites were more frequent than the reverse. Theta waves in different parts of the septum were synchronized with each other but medial septal sites showed less frequent theta than other sites. The phase delays between medial and lateral septal sites were < 10 ms, suggesting that the hippocampus does not act as a simple relay between the two. Spectral analysis revealed periods (> 5 s) of theta at hippocampal sites co‐occurring with rhythms at multiple septal sites that were slower than theta. Even slower were the ‘slow septal waves’ (mean 2.7 Hz), which were present in the absence of locomotion and did not ‘drive’ the hippocampus. Our data suggest that the pacemaker of hippocampal theta may best be thought of as a set of functionally differentiated components rather than as a single homogenous unit.
Net influx of plasma 6‐[18F]fluoro‐l‐DOPA (FDOPA) to the ventral striatum correlates with prefrontal processing of affective stimuli
Authors: Siessmeier Thomas , Kienast Thorsten , Wrase Jana , Larsen Jennifer Lynne , Braus Dieter F. , Smolka Michael N. , Buchholz Hans Georg , Schreckenberger Mathias , Rösch Frank , Cumming Paul , Mann Karl , Bartenstein Peter , Heinz Andreas
Published: July 2006

Dopaminergic neurotransmission in the ventral and dorsal striatum interact with central processing of rewarding and reward‐indicating stimuli, and may affect frontocortical–striatal–thalamic circuits regulating goal‐directed behaviour. Thirteen healthy male volunteers were investigated with multimodal imaging, using the radioligand 6‐[18F]fluoro‐l‐DOPA (FDOPA) for positron emission tomography (PET) measurements of dopamine synthesis capacity, and also functional magnetic resonance imaging (fMRI) in a cognitive activation paradigm. We calculated the correlation between FDOPA net blood–brain influx (; ml/g/min) in the ventral and associative dorsal striatum and BOLD signal changes elicited by standardized affectively positive, negative and neutral visual stimuli. The magnitude of in the ventral striatum was positively correlated with BOLD signal increases in the left anterior cingulate cortex and right insular operculum elicited by positive vs. neutral stimuli, but not negative vs. neutral stimuli. In the dorsal striatum, the magnitude of was positively correlated with processing of positive and negative stimuli in the left dorsolateral prefrontal cortex. These findings suggest that dopamine synthesis capacity in the ventral striatum correlates with the attentional processing of rewarding positive stimuli in the anterior cingulate cortex of healthy subjects. Dopaminergic neurotransmission in the associative dorsal striatum has been associated previously with habit learning. The observed correlation between dopamine synthesis capacity in the dorsal striatum and BOLD signal changes in the dorsolateral prefrontal cortex suggests dopaminergic modulation of processing of emotional stimuli in brain areas associated with motor planning and executive behaviour control.
Making the Smart Choice: a systemic response to school‐based violence
Authors: Breunlin Douglas C. , Cimmarusti Rocco A. , Hetherington Joshua S. , Kinsman Jayne
Published: July 2006

This paper reports on a school‐based intervention in which a family therapist, serving as a consultant to a high school, worked with that school to reduce the level of school‐based violence. The primary intervention reported in this paper is a conflict skills training programme called ‘Making the Smart Choice’. While designed for the families of students suspended for physical violence, this intervention also impacts upon the school's disciplinary system and the climate of the school itself. The context or responses to school‐based violence, the strategy to gain access to the school, the politics of developing such a programme, the programme itself and the infrastructure needed to maintain it are described. For four years, suspensions for school‐based violence were halved compared to the four years prior to the start of the programme.
Anorexia nervosa: treatment satisfaction
Authors: Paulson‐Karlsson Gunilla , Nevonen Lauri , Engström Ingemar
Published: July 2006

Patient satisfaction plays a central role in treatment alliance and outcome. Investigating patient expectations and experiences of treatment sheds light on its importance. This study examines adolescent anorexia nervosa patients and their parents' satisfaction with family‐based treatment. Patients and parents answered a questionnaire at the eighteen‐month follow‐up focusing on expectations and experiences of treatment, therapists, aims of treatment and accomplishment. The results show that 73 per cent of the patients and 83 per cent of the parents felt that their pre‐treatment expectations had been fulfilled. The majority agreed that individual patient sessions and parental sessions were of great help, while the patients valued family therapy sessions as being less helpful than did parents. In overall terms, parents were more pleased with the therapists than were the patients. These data suggest that family‐based treatment with individual sessions for patients, in parallel with parental sessions combined with family sessions, corresponds well to patients' and parents' treatment expectations.
You May Worry, But Can You Recognize Threats When You See Them?; Neuroticism, Threat Identifications, and Negative Affect
Authors: Tamir Maya , Robinson Michael D. , Solberg Emily Crawford
Published: July 2006

ABSTRACT
The present studies sought to investigate the hedonic consequences of threat‐identification skills at low and high levels of neuroticism. Such skills were assessed in terms of both speed (Study 1) and accuracy (Study 2) of identifying threatening objects in cognitive tasks. As predicted, threat‐identification skills interacted with trait neuroticism in predicting subjective experiences. Specifically, individuals high in neuroticism experienced lower levels of negative affect during their everyday lives if they were also skilled in identifying threats in the cognitive tasks (Studies 1–2). Such skills did not matter at low levels of neuroticism. This interactive pattern was also replicated in the context of life domain satisfaction (Study 2). The results support the view that avoidance motivation encompasses multiple component processes, including some that are cognitive in nature, and specifically extends self‐regulatory views of neuroticism. Of most importance, our data indicate that threat‐identification skills can be hedonically beneficial, rather than costly, at high levels of neuroticism.
Word stress production in three‐year‐old children at risk of dyslexia
Authors: De Bree Elise , Wijnen Frank , Zonneveld Wim
Published: July 2006

We investigated Dutch word stress acquisition in 3‐year‐old children at risk of dyslexia (children with at least one parent or older sibling with reading difficulties) and normally developing children, in order to shed light on language acquisition delays in children at risk of dyslexia, as well as to investigate further phonological deficits in dyslexia. The children had to repeat non‐words with stress patterns varying in regularity. Both the at‐risk and control children performed better on imitation of regular stress targets and worse on irregular and prohibited stress patterns. However, the at‐risk children showed more difficulty imitating irregular and prohibited patterns, and had lower percentages phonemes correct than the control group. The results can be interpreted as a delay in word stress acquisition in the at‐risk group. The findings thus point towards a phonological deficit early in language development.
Auditory and motor rhythm awareness in adults with dyslexia
Authors: Thomson Jennifer M. , Fryer Ben , Maltby James , Goswami Usha
Published: July 2006

Children with developmental dyslexia appear to be insensitive to basic auditory cues to speech rhythm and stress. For example, they experience difficulties in processing duration and amplitude envelope onset cues. Here we explored the sensitivity of adults with developmental dyslexia to the same cues. In addition, relations with expressive and receptive rhythm tasks, such as tempi recognition and manual tapping to a metronome, were explored. Our goal was to investigate whether the auditory deficits seen in dyslexia are specific to cues to speech rhythm and stress, or are part of a wider rhythmic awareness problem. A group of 19 undergraduate students with dyslexia were compared with 20 age‐ and ability‐matched controls. The findings confirmed a relationship between auditory rhythm sensitivity and literacy in adults, as well as showing an association with metronome inter‐tap‐interval variability.
Effects of human–carnivore conflict on tiger (Panthera tigris) and prey populations in Lao PDR
Authors: Johnson A. , Vongkhamheng C. , Hedemark M. , Saithongdam T.
Published: July 2006

Unique to South‐east Asia, Lao People's Democratic Republic contains extensive habitat for tigers and their prey within a multiple‐use protected area system covering 13% of the country. Although human population density is the lowest in the region, the impact of human occurrence in protected areas on tiger Panthera tigris and prey populations was unknown. We examined the effects of human–carnivore conflict on tiger and prey abundance and distribution in the Nam Et‐Phou Louey National Protected Area on the Lao–Vietnam border. We conducted intensive camera‐trap sampling of large carnivores and prey at varying levels of human population and monitored carnivore depredation of livestock across the protected area. The relative abundance of large ungulates was low throughout whereas that of small prey was significantly higher where human density was lower. The estimated tiger density for the sample area ranged from 0.2 to 0.7 per 100 km2. Tiger abundance was significantly lower where human population and disturbance were greater. Three factors, commercial poaching associated with livestock grazing followed by prey depletion and competition between large carnivores, are likely responsible for tiger abundance and distribution. Maintaining tigers in the country's protected areas will be dependent on the spatial separation of large carnivores and humans by modifying livestock husbandry practices and enforcing zoning.
Influence of anthropogenic disturbance on bird communities in a tropical dry forest: role of vegetation structure
Authors: Shahabuddin G. , Kumar R.
Published: July 2006

A study was carried out in Sariska Tiger Reserve in India to investigate the effects of anthropogenic disturbance caused by biomass extraction on the bird communities of tropical dry forests. The study was based on comparisons of the avifaunal community as well as vegetation structure between strictly protected (‘undisturbed’) and intensively used (‘disturbed’) sites that were demarcated a priori on the basis of disturbance indicators. There was no significant difference in the number of recorded species and bird abundance between disturbed and undisturbed sites. However, bird species diversity was significantly lower in disturbed sites. Bird species composition was found to differ significantly between disturbed and undisturbed sites and was associated with the measured disturbance indicators. Changes in bird species composition occurred because of seven of 26 locally abundant bird species (26.9%) responding significantly to the disturbance regime. All the affected bird species are primarily insectivorous. Bird species composition was significantly related to six vegetation structural variables, including two that were significantly altered by disturbance. Changes in vegetation structure accounted for all the changes in bird species composition caused by disturbance. However, vegetation structure had additional effects on bird species composition besides those caused simply by disturbance. Thus, our study indicates that forest use in the form of chronic biomass extraction can have significant effects upon bird diversity and species composition of tropical dry forest. There is a need to retain a proportion of natural ecosystems as inviolate if the full complement of biodiversity is to be conserved.
Critical habitat during the transition from maternal provisioning in freshwater fish, with emphasis on Atlantic salmon (Salmo salar) and brown trout (Salmo trutta)
Authors: Armstrong J. D. , Nislow K. H.
Published: July 2006

In freshwater fish, the transition from dependence on maternal yolk reserves to independent foraging can be an early critical period, with survival during this stage having a strong influence on population abundance and cohort strength. Information concerning Atlantic salmonSalmo salarand brown troutSalmo truttaas model species is reviewed to show how population dynamics are influenced by habitat use during the transitional stage and illustrate the role of maternal provisioning along with density‐dependent and ‐independent factors. The allocation of resources in yolk and timing and position of spawning strongly influence the biotic and abiotic environments of juveniles and their subsequent performance. Vulnerability to predators, adverse environmental conditions and restricted conditions over which they can successfully forage result in specific habitat requirements for newly independent juveniles. The availability of slow‐flowing habitats at stream margins during the first month of independence is crucial. Alteration of natural flow regimes and physical habitat structure, associated with a wide range of anthropogenic influences, can have significant deleterious effects on the availability of critical juvenile habitat. A model combining habitat structure and the relationship between density‐dependent and ‐independent mortality is presented to explore the range of conditions under which the transitional period would have a strong influence on population abundance. This model provides a framework for establishing thresholds or optima for habitat availability that will favour sufficient recruitment out of the transitional stage. Using the modelling framework, managers can make informed decisions on the utility and cost effectiveness of fisheries and habitat management activities designed to increase juvenile survival during the transition to independence. A range of management options is outlined for improving habitat quality and increasing juvenile survival during the transitional period, including restoration of structural complexity, provision of suitable flow regimes, and tailoring stocking and reintroduction strategies to mimic natural dynamics.
Habitat selection and habitat‐specific survival of fledgling ovenbirds (Seiurus aurocapilla)
Authors: King D. I. , Degraaf R. M. , Smith M.‐L. , Buonaccorsi J. P.
Published: July 2006

Patterns of habitat use by some passerines change after the young leave the nest, and thus our understanding of habitat selection derived from counts of singing males earlier in the nesting cycle may not adequately represent the breeding habitat requirements of these species. Post‐fledging changes in habitat use may have important conservation implications if the survival of fledglings is affected by characteristics of the habitat; however, there have been relatively few systematic studies of the post‐fledging ecology of forest passerines and, of these, even fewer have incorporated analyses of the relationship between habitat characteristics and fledgling survival. We studied the post‐fledging habitat selection and survival of ovenbirdsSeiurus aurocapillain northern New Hampshire, USA during two breeding seasons using radio telemetry. Habitat at sites used by radio‐marked fledgling ovenbirds was characterized by fewer large trees and greater vertical structure 0–3 m above ground than ovenbird nest sites. Similarly, habitat at sites used by fledgling ovenbirds was characterized by fewer large trees and greater vertical structure than unused sites. Most (80%) of the 15 mortalities that we observed were due to predation. Nine (70%) of these occurred within the first 3 days of fledging, resulting in a significant drop in survival during this period. Fledgling survival increased significantly with increased vegetation structure. Our observations that fledgling ovenbirds are selective in their habitat use, that they select different habitat features than adult ovenbirds select for nesting and that fledgling survival is positively associated with these habitat features suggest that the use of habitat models based on counts of singing males before fledging does not adequately represent the habitat needs of this species. Conceivably, mortality during the post‐fledging period could limit recruitment to levels insufficient to maintain the viability of ovenbird population even if adequate nesting habitat were available.
Transition to independence by subadult beavers (Castor canadensis) in an unexploited, exponentially growing population
Authors: DeStefano S. , Koenen K. K. G. , Henner C. M. , Strules J.
Published: July 2006

We conducted a 4‐year study of beaversCastor canadensisto compare the movements, survival and habitat of adults established in existing colonies to juveniles dispersing to new sites in a region with high beaver densities along a suburban–rural gradient. Estimates of annual survival were high for adult and juvenile beavers. Of nine known mortalities, seven (78%) were juveniles. Mortalities occurred during spring–summer, and none during fall–winter. There was a trend toward higher‐to‐lower survival along the suburban–rural gradient, respectively. Human‐induced mortality (e.g. trapping and shooting) was higher in rural areas, whereas nonhuman‐induced mortality (e.g. disease, accidents) was higher in suburban areas. Fifteen (14 subadults and one adult) beavers moved from natal colonies to other areas. The average dispersal distance for subadults was 4.5 km (se=1.0) along streams or rivers, or 3.5 km (se=0.7) straight‐line point‐to‐point. Most dispersal movements were made in spring (April–June). In two cases, individual subadults made return movements from their dispersal sites back to their natal colonies. Dispersal sites tended to be in smaller, shallower wetlands or streams and in areas with higher overstorey canopy closure compared with natal colonies. Woody vegetation usually preferred by beavers for food tended to be less common at dispersal sites than at natal colonies. In regions with high densities of beaver, dispersing juveniles are likely to attempt to colonize lower quality sites. High densities of beavers also lead to more human–beaver conflicts and, in Massachusetts, the pest control management options in place during the past decade have been ineffectual at controlling population levels. Alternately, in regions with no beavers or very low densities and where reintroductions are being attempted, the landscape matrix surrounding release sites should include suitable sites for dispersing young to establish colonies.
Prioritising for fertility treatments—the effect of excluding women with a high body mass index
Authors: Gillett WR , Putt T , Farquhar CM
Published: July 2006

The effect of clinical priority access criteria for access to infertility treatment was examined for women outside the body mass index (BMI) range of 18–32 kg/m2. Treatments and outcomes were analysed from 1280 cases referred from 1998 to May 2005. Sixteen percent of women had a BMI of >32 kg/m2. Overall, 38% of these women had a birth from conceiving a treatment‐related pregnancy or spontaneous pregnancy, compared with 52% of women with BMI < 32 kg/m2. Weight loss allowed women in the BMI group >32<35 kg/m2 to access treatment, but women in higher BMI groups were less successful.
Cell death pathways differ in several mouse models with motoneurone disease: analysis of pure motoneurone populations at a presymptomatic age
Authors: Perrin Florence E. , Boisset Gaelle , Lathuilière Aurélien , Kato Ann C.
Published: July 2006

To identify candidate genes that are responsible for motoneurone degeneration, we combined laser capture microdissection with microarray technology. We analysed gene expression in pure motoneurones from two mouse mutants that develop motoneurone degeneration, progressive motor neuronopathy and wobbler. At a presymptomatic age, there was a significant differential expression of a restricted number of genes (25 and 72 in progressive motor neuronopathy and wobbler respectively, of 22 600 transcripts screened). We compared these results to our previous analyses in the copper–zinc superoxide dismutase mutant mouse (SOD1G93A) in which we observed a de‐regulation of 27 genes. Some of these genes were de‐regulated uniquely in one mouse mutant and some have already been identified in cell death pathways implicated in amyotrophic lateral sclerosis and animal models of motoneurone degeneration (i.e. de‐regulation of intermediate filaments, axonal transport, the ubiquitin–proteasome system and excitotoxicity). One gene, vimentin, was differentially up‐regulated in all mouse mutants; this main candidate gene has been confirmed by in situ hybridization and immunohistochemistry to be expressed in motoneurones in all mouse mutants. Furthermore, vimentin expression correlated with the state of motoneurone degeneration. These results identify early molecular changes that may be involved in the pathogenesis of motoneurones leading to cell death and favour a complex multipathway induction of the disease; surprisingly, there was no important modification in cell death‐associated genes. This is the first study to show a clear difference in the genes that are de‐regulated at an early stage in three different mouse models of motoneurone disease.
Microsatellite markers for the Sydney rock oyster, Saccostrea glomerata, a commercially important bivalve in southeastern Australia
Authors: BANKS S. C. , PIGGOTT M. P. , RAFTOS D. A. , BEHEREGARAY L. B.
Published: July 2006

The Sydney rock oyster (Saccostrea glomerata) is a commercially important bivalve in southeastern Australian. We describe the isolation and characterization of nine microsatellite markers for S. glomerata. The loci are highly polymorphic, with between five and 20 alleles identified among 30 individuals. Expected heterozygosity levels ranged from 0.608 to 0.936. The markers will be used to study natural dispersal, translocations and population structure. We will also use the microsatellites to test the genetic effects of QX disease on oyster populations. This infectious parasitic disease has decimated S. glomerata productivity in a number of areas over the past few decades.
Extending networks and mediating brands: stallholder strategies in a Mauritian market
Authors: Edensor Tim , Kothari Uma
Published: July 2006

We examine how increasingly volatile global flows and tenuous networks rearrange local spaces and are inhabited by local people by looking at the strategies adopted by stallholders on a Mauritian market who acquire and sell locally manufactured branded clothes. Continuously (re)negotiating their connections to power‐holders within networks of clothing production, we highlight how these traders achieve momentarily stable arrangements within a context where their entrepreneurial strategies are constrained. Further, in exploring how traders distinguish their wares, we investigate how multiple meanings and values circulate around these branded clothes as global objects.
VARIATIONS OF PSP TOXIN PROFILES DURING DIFFERENT GROWTH PHASES IN GYMNODINIUM CATENATUM (DINOPHYCEAE) STRAINS ISOLATED FROM THREE LOCATIONS IN THE GULF OF CALIFORNIA, MEXICO1
Authors: Band‐Schmidt Christine , Bustillos‐Guzmán José , Morquecho Lourdes , Gárate‐Lizárraga Ismael , Alonso‐Rodríguez Rosalba , Reyes‐Salinas Amada , Erler Katrin , Luckas Bernd
Published: July 2006

In vitro experiments were performed with Gymnodinium catenatum Graham strains isolated from three locations in the Gulf of California to determine the variability in toxicity and toxin profiles. Strains were cultivated in GSe at 20°C±1°C, 150 μmol photons·m−2·s−1 (12:12 light:dark cycle), and harvested during different growth phases. Growth rates were higher than in previous studies, varying between 0.70 and 0.82 day−1. The highest cell yields were reached at 16 and 19 days, with maximum densities between 1090 and 3393 cells·mL−1. Bahía de La Paz (BAPAZ) and Bahía de Mazatlán (BAMAZ) were the most toxic (101 pg STXeq·cell−1), whereas strains from Bahía Concepción (BACO) were the least toxic (13 pg STXeq·cell−1). A strain isolated from cyst germination was one of the least toxic strains. No significant changes in toxin content with culture age were observed (0.2 and 0.6 pmol paralytic shellfish poisoning·cell−1). All strains contained neosaxitoxin (NEOSTX), decarbamoyl‐saxitoxin (dcSTX), decarbamoyl‐gonyautoxin‐2,‐3, (dcGTX2‐3), N‐sulfo‐carbamoylsaxitoxin (B1), N‐sulfo‐carbamoylneosaxitoxin (B2), and N‐sulfo‐carbamoylgonyautoxin‐2,‐3 (C1‐2). Bahía Concepción strains had the highest content of C1; BAPAZ and BAMAZ strains had a higher percentage of NEOSTX. Differences in toxin composition with culture age were observed only in BAMAZ and BAPAZ strains. Cultures with a higher percentage of long chains had more NEOSTX, while those with a higher proportion of short chains had a lower content of NEOSTX. Gulf of California strains are characterized by a high proportion of NEOSTX, and seem to have evolved particular physiological responses to their environment that are reflected in the toxin profile, suggesting different populations.
LIFE CYLE AND SEXUALITY OF THE FRESHWATER RAPHIDOPHYTE GONYOSTOMUM SEMEN (RAPHIDOPHYCEAE)1
Authors: Figueroa Rosa Isabel , Rengefors Karin
Published: July 2006

Previously unknown aspects in the life cycle of the freshwater flagellate Gonyostomum semen (Ehrenb.) (Raphidophyceae) are described here. This species forms intense blooms in many northern temperate lakes, and has increased in abundance and frequency in northern Europe during the past decades. The proposed life cycle is based on observations of life cycle stages and transitions in cultures. Viable stages of the life cycle were individually isolated and monitored by time‐lapse photography. The most common processes undertaken by the isolated cells were: division, fusion followed by division, asexual cyst formation, and sexual cyst formation. Motile cells divided by two different processes. One lasted between 6 and 24 h and formed two cells with vegetative cell size and with or without the same shape. The second division process lasted between 10 and 20 min and formed two identical cells, half the size of the mother cell. Planozygotes formed by the fusion of hologametes subsequently underwent division into two cells. Asexual cyst‐like stages were spherical, devoid of a thick wall and red spot, and germinated in 24–48 h. Heterogamete pairs were isogamous, and formed an angle of 0–90° between each other. Planozygote and sexual cyst formation were identified within strains established from one vegetative cell. The identity of these strains, which was studied by an amplified fragment length polymorphism analysis, was correlated with the viability of the planozygote. Resting cyst germination was described using cysts collected in the field. The size and morphology of these cysts were comparable with those formed sexually in culture. The excystment rate was higher at 24°C than at 19 or 16°C, although the cell liberated during germination (germling) was only viable at 16°C. The placement of G. semen within the Raphidophyceae family was confirmed by sequence analysis of a segment of the 18S ribosomal DNA.
A NOVEL ALKALINE PHOSPHATASE IN THE COCCOLITHOPHOREEMILIANIA HUXLEYI(PRYMNESIOPHYCEAE) AND ITS REGULATION BY PHOSPHORUS1
Authors: Xu Yan , Wahlund Thomas M. , Feng Liang , Shaked Yeala , Morel François M. M.
Published: July 2006

Alkaline phosphatase (AP) plays an important role in the regeneration of bioavailable phosphate from organic compounds and allows phytoplankton growing in low inorganic phosphate environments to acquire phosphorus. We report the isolation, cloning, and initial characterization of the first AP (ehap1) in the coccolithophoreEmiliania huxleyi(Lohm.) Hay and Mohler. This novel AP is a major form of AP released from the cell surface into the medium at late exponential and stationary phase of P‐limited batch cultures but has no significant sequence similarity to other known APs. The cDNA sequence encodes a protein of roughly 94 kDa, while the processed active EHAP1 released from the cell surface is roughly 75 kDa. This difference is due to the cleavage of the signal sequence at its N‐terminus and perhaps some truncation at its C‐terminus. In response to variations in phosphate levels, the expression ofehap1was found to correlate well with cellular AP activity. Theehap1transcript was induced 4 h after phosphate depletion, increasing 1000‐fold within a day, and was repressed rapidly upon phosphate addition. These results provide the basis for developing specific probes to study the expression of AP, and thus phosphate stress, of field populations.
OOGAMOUS REPRODUCTION, WITH TWO‐STEP AUXOSPORULATION, IN THE CENTRIC DIATOM THALASSIOSIRA PUNCTIGERA (BACILLARIOPHYTA)1
Authors: Chepurnov Victor A. , Mann David G. , Von Dassow Peter , Armbrust E. Virginia , Sabbe Koen , Dasseville Renaat , Vyverman Wim
Published: July 2006

Thalassiosira species are common components of marine planktonic communities worldwide and are used intensively as model experimental organisms. However, data on life cycles and sexuality within the genus are fragmentary. A clone of the cosmopolitan marine diatom Thalassiosira punctigera Cleve emend. Hasle was isolated from the North Sea and oogamous sexual reproduction was observed in culture. Cells approximately 45 μm and smaller became sexualized. Oogonia were produced preferentially and spermatogenesis was infrequent. Unfertilized oogonia always aborted and their development was apparently arrested at prophase of meiosis I. Further progression through meiosis and auxospore formation occurred only after a sperm had penetrated into the oocyte. Many cells of the new large‐celled generation (approximately 90–120 μm in size) immediately became sexualized again but only oogonia were produced. A few of the large oogonia became auxospores and produced initial cells 132–153 μm in diameter. The second step of auxosporulation probably involved fertilization of large‐celled oocytes by the sperm of the small‐celled spermatogonangia that were still present in the culture. An F1 clone obtained after selfing within the small‐celled auxosporulation size range was investigated. Like the parent clone, the F1 clone was homothallic but no auxosporulation was observed: spermatogonangia were unable to produce viable sperm, apparently because of inbreeding depression. Aggregation and interaction of oogonia were documented, and may be relevant for understanding the mechanisms of signaling and recognition between sexualized cells and the evolution of sexuality in pennate diatoms.
CRYPTOPERIDINIOPSIS BRODYI GEN. ET SP. NOV. (DINOPHYCEAE), A SMALL LIGHTLY ARMORED DINOFLAGELLATE IN THE PFIESTERIACEAE1
Authors: Steidinger Karen A. , Landsberg Jan H. , Mason Patrice L. , Vogelbein Wolfgang K. , Tester Patricia A. , Wayne Litaker R.
Published: July 2006

A new genus and species of heterotrophic dinoflagellate, Cryptoperidiniopsis brodyi gen. et sp. nov., are described. This new species commonly occurs in estuaries from Florida to Maryland, and is often associated with Pfiesteria piscicida Steidinger et Burkholder, Pseudopfiesteria shumwayae (Glasgow et Burkholder) Litaker et al., and Karlodinium veneficum (Ballantine) J. Larsen, as well as other small (<20 μm) heterotrophic and mixotrophic dinoflagellates. C. brodyi gen. et sp. nov. feeds myzocytotically on pigmented microalgae and other microorganisms. The genus and species have the enhanced Kofoidian plate formula of Po, cp, X, 5′, 0a, 6″, 6c, PC, 5+s, 5″′, 0p, and 2″″ and are assigned to the order Peridiniales and the family Pfiesteriaceae. Because the Pfiesteriaceae comprise small species and are difficult to differentiate by light microscopy, C. brodyi gen. et sp. nov. can be easily misidentified.
RELATIONSHIPS BETWEEN GROWTH RATE, CELL SIZE, AND INDUCTION OF SPERMATOGENESIS IN THE CENTRIC DIATOM THALASSIOSIRA WEISSFLOGII (BACILLARIOPHYTA)1
Authors: Von Dassow Peter , Chepurnov Victor A. , Armbrust E. Virginia
Published: July 2006

Patterns of changes in cell size, growth rate, and the inducibility of spermatogenesis were followed in eight sub‐clones of two isolates of the centric diatom Thalassiosira weissflogii (Grunow) Fryxell & Hasle grown at saturating light. One isolate originated from Long Island Sound, New York, USA and the other originated from Jakarta Harbor, Indonesia. As expected from previous studies, oscillations between intervals of cell size reduction and cell size enlargement were observed for each sub‐clone. For both isolates, sperm were easily detected, but cells resembling eggs and auxospores were rarely observed and fertilization was not confirmed, suggesting that the observed cell size increases may have resulted from a combination of asexual cell enlargement and rare auxosporulation. The two isolates differed in their minimum and maximum sizes, and the threshold size for the induction of sperm formation. However, the two sets of isolated sub‐clones displayed comparable relationships between growth rate, sperm inducibility, and cell size relative to the minimum, maximum, and threshold sizes. Growth rate increased as cell size decreased during vegetative divisions until the threshold for sperm inducibility was crossed. Below the size threshold for sperm inducibility, growth rate declined as cell size continued to decrease. Smaller cells were susceptible to failure of normal cytokinesis and valve deposition, resulting in the formation of abnormally long and often multinucleate cells. Culture conditions may select against restoration of cell size via auxosporulation due to the relationship between growth rate and cell size.
RE‐EXAMINATION OF THE DOUBLE BOND POSITIONS IN ALKENONES AND DERIVATIVES: BIOSYNTHETIC IMPLICATIONS1
Authors: Rontani Jean‐François , Prahl Fredrick G. , Volkman John K.
Published: July 2006

By derivatizing with OsO4, we determined the double bond positions of all the diunsaturated alkenones present in different haptophytes and demonstrated that the positions in C37–C40homologs occur at a fixed carbon number from the carbonyl group, a finding contrary to earlier speculation. These data have allowed us to recognize three “families” of alkenones, for which we propose different biosynthetic pathways. The proposed biosynthesis of classical C37–C40alkenones starts with acetyl‐ or propionyl‐SCoA and involves classical chain elongation steps with malonyl‐ and methylmalonyl‐SCoA affording alkanoyl‐ACP intermediates, which undergo subsequent Δ14, 21‐desaturation and decarboxylation reactions. Unusual diunsaturated shorter‐chain (C35and C36) ketones now being produced for yet unknown physiological reasons by our specimen ofEmiliania huxleyi(Lohm). Hay et Mohler strain CCMP1742. These compounds exhibit ω15,22 and ω16,23 double bonds, which are at a shorter distance (two carbon atoms) from the carbonyl group than the higher homologs, implying that their biosynthesis must involve an additional chain‐shortening step after Δ14, 21‐desaturation of alkanoyl‐ACP. Alkenones exhibiting a very unusual double bond spacing (three methylene groups instead of five) were detected in Holocene Black Sea sediments, in particulate matter collected in the Ligurian Sea and inGephyrocapsa oceanicastrain JB‐02. The formation of these compounds seems to be linked to the biosynthesis of monounsaturated alkenones previously detected in several haptophytes. Our work demonstrates the value of determining the double bond locations of alkenones whenever possible.
Effect of Interface Structure on the Microstructural Evolution of Ceramics
Authors: Jo Wook , Kim Doh‐Yeon , Hwang Nong‐Moon
Published: July 2006

The interface atomic structure was proposed to have a critical effect on microstructure evolution during sintering of ceramic materials. In liquid‐phase sintering, spherical grains show normal grain growth behavior without exception, while angular grains often grow abnormally. The coarsening process of spherical grains with a disordered or rough interface atomic structure is diffusion‐controlled, because there is little energy barrier for atomic attachments. On the other hand, kink‐generating sources such as screw dislocations or two‐dimensional (2‐D) nuclei are required for angular grains having an ordered or singular interface structure. Coarsening of angular grains based on a 2‐D nucleation mechanism could explain the abnormal grain growth behavior. It was also proposed that a densification process is closely related to the interface atomic structure. Enhanced densification by carefully chosen additives during solid state sintering was explained in terms of the grain‐boundary structural transition from an ordered to a disordered open structure.
Tribological Behavior of SiC‐Reinforced Ti3SiC2‐Based Composites under Dry Condition and under Lubricated Condition with Water and Ethanol
Authors: Hibi Yuko , Miyake Koji , Murakami Takashi , Sasaki Shinya
Published: July 2006

To evaluate the lubrication compatibility of SiC‐reinforced Ti3SiC2‐based composites, i.e., a Ti3SiC2/SiC composite, with water and alcohol, sliding experiments were conducted under dry condition and lubricated with water and C2H5OH. The friction and wear of the Ti3SiC2/SiC composite decreased in the order of dry condition, in water, and in C2H5OH. The worn surfaces indicated that oxide masses, which caused oxidation wear and abrasive wear, were formed by tribo‐oxidation on the sliding surface under the dry condition and in water, while tribo‐oxidation scarcely occurred in C2H5OH.
Diffuse Ferroelectric Phase Transition and Relaxor Behaviors in Ba‐Based Bismuth Layer‐Structured Compounds and La‐Substituted SrBi4Ti4O15
Authors: Hou R. Z. , Chen X. M. , Zeng Y. W.
Published: July 2006

The dielectric characteristics of BaBi2Nb2O9, BaBi4Ti4O15, BaBi8Ti7O27, and La‐substituted SrBi4Ti4O4 were investigated to discuss their ferroelectric phase transition and relaxor behaviors. BaBi2Nb2O9 showed typical relaxor behaviors, and a shift of Tm with increasing frequency was observed in BaBi4Ti4O15 and SrBi4−xLaxTi4O15 (x=0.8, 1.0) but they underwent a real paraelectric–ferroelectric phase transition on zero‐field cooling, while BaBi8Ti7O27 showed a normal ferroelectric nature. The reduced concentration and weakened coupling of the dipoles related to A‐site bismuth are believed to be responsible for the appearance of short‐range electric ordering and the relaxor behaviors in these bismuth layer‐structured compounds.
The Motivation Behind Serial Sexual Homicide: Is It Sex, Power, and Control, or Anger?*
Authors: Myers Wade C. , Husted David S. , Safarik Mark E. , O'Toole Mary Ellen
Published: July 2006

ABSTRACT: Controversy exists in the literature and society regarding what motivates serial sexual killers to commit their crimes. Hypotheses range from the seeking of sexual gratification to the achievement of power and control to the expression of anger. The authors provide theoretical, empirical, evolutionary, and physiological support for the argument that serial sexual murderers above all commit their crimes in pursuit of sadistic pleasure. The seeking of power and control over victims is believed to serve the two secondary purposes of heightening sexual arousal and ensuring victim presence for the crime. Anger is not considered a key component of these offenders' motivation due to its inhibitory physiological effect on sexual functioning. On the contrary, criminal investigations into serial sexual killings consistently reveal erotically charged crimes, with sexual motivation expressed either overtly or symbolically. Although anger may be correlated with serial sexual homicide offenders, as it is with criminal offenders in general, it is not causative. The authors further believe serial sexual murderers should be considered sex offenders. A significant proportion of them appear to have paraphilic disorders within the spectrum of sexual sadism. “sexual sadism, homicidal type” is proposed as a diagnostic subtype of sexual sadism applicable to many of these offenders, and a suggested modification of DSM criteria is presented.
A Method for Enhancing Gunshot Residue Patterns on Dark and Multicolored Fabrics Compared with the Modified Griess Test*
Authors: Bailey James A. , Casanova Ruby S. , Bufkin Kim
Published: July 2006

ABSTRACT: In using infrared or infrared‐enhanced photography to examine gunshot residue (GSR) on dark‐colored clothing, the GSR particles are microscopically examined directly on the fabric followed by the modified Griess test (MGT) for nitrites. In conducting the MGT, the GSR is transferred to treated photographic paper for visualization. A positive reaction yields an orange color on specially treated photographic paper. The examiner also evaluates the size of the powder pattern based on the distribution of nitrite reaction sites or density. A false‐positive reaction can occur using the MGT due to contaminants or dyes that produce an orange cloud reaction as well. A method for enhancing visualization of the pattern produced by burned and partially unburned powder is by treatment of the fabric with a solution of sodium hypochlorite. In order to evaluate the results of sodium hypochlorite treatment for GSR visualization, the MGT was used as a reference pattern. Enhancing GSR patterns on dark or multicolored clothing was performed by treating the fabric with an application of 5.25% solution of sodium hypochlorite. Bleaching the dyes in the fabric enhances visualization of the GSR pattern by eliminating the background color. Some dyes are not affected by sodium hypochlorite; therefore, bleaching may not enhance the GSR patterns in some fabrics. Sodium hypochlorite provides the investigator with a method for enhancing GSR patterns directly on the fabric. However, this study is not intended to act as a substitute for the MGT or Sodium Rhodizonate test.
The Application of Ultraviolet Irradiation to Exogenous Sources of DNA in Plasticware and Water for the Amplification of Low Copy Number DNA
Authors: Tamariz Jeannie , Voynarovska Kristina , Prinz Mechthild , Caragine Theresa
Published: July 2006

ABSTRACT: Using high sensitivity forensic STR polymerase chain reaction (PCR) typing procedures, we have found low concentrations of DNA contamination in plasticware and water assumed to be sterile, which is not detected by standard DNA procedures. One technique commonly used to eliminate the presence of DNA is ultraviolet (UV) irradiation; we optimized such a protocol used in the treatment of water, tubes, plates, and tips for low copy number DNA (LCN) amplification. UV light from a Stratalinker® 2400 was administered to 0.2, 1.5 mL tubes, and PCR plates contaminated with up to 500 pg of DNA. They were subsequently quantified with an ALU‐based real‐time PCR method using the Rotorgene 3000. Overall, there was a decrease in concentration of DNA recovered as the duration of treatment increased. Nonetheless, following 45 min of irradiating a PCR plate with 500 pg of DNA, nearly 6 pg were still detected. However, when the plate was raised within an inch of the UV source, less than 0.2 pg of DNA was detected. Additionally, lining the area around the samples with aluminum foil further reduced the amount of time necessary for irradiation, as only 30 min eliminated the presence DNA in the raised PCR plate. Similar experiments were conducted using tubes filled with a solution of DNA and water in equivalent concentrations for 50, 15, and 1.5 mL tubes with comparative results. It is plausible that the aluminum foil increased the amount of reflection in the area thereby enhancing penetration of UV rays through the walls of the plasticware. This protocol was tested for the possibility of inhibitors produced from irradiation of plastic tubes. As our protocols require less irradiation time than previous studies, PCR sensitivity was not affected. Moreover, the lifespan of the UV lamps was extended. Our findings demonstrate that this method is useful as an additional precautionary measure to prevent amplification of extraneous DNA from plasticware and water without compromising the sensitivity of LCN DNA amplifications.