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Selected AbstractsNanoscale uniformity of pore architecture in diatomaceous silica: a combined small and wide angle x-ray scattering studyJOURNAL OF PHYCOLOGY, Issue 1 2000Engel G. Vrieling Combined small and wide angle X-ray scattering (SAXS and WAXS) analysis was applied to purified biogenic silica of cultured diatom frustules and of natural populations sampled on marine tidal flats. The overall WAXS patterns did not reveal crystalline phases (WAXS domain between 0.07 to 0.5 nm) in this biogenic silica, which is in line with previous reports on the amorphous character of the SiO2 matrix of diatom frustules. One exception was the silica of the pennate species Cylindrotheca fusiformis Reimann et Lewin, which revealed wide peaks in the WAXS spectra. These peaks either indicate the presence of a yet unknown crystalline phase with a repetitive distance (d -value ,0.06 nm) or are caused by the ordering of the fibrous silica fragments; numerous girdle bands. The SAXS spectra revealed the size range of pores (diameter d between 3.0 and 65 nm), the presence of distinct pores (slope transitions), and structure factors (oscillation of the spectra). All slopes varied in the range of ,4.0 to ,2.5, with two clear common regions among species: d < 10 nm (slopes ,4, denoted as region I and also called the Porod region), and 10.0 < d < 40.0 nm (slopes ,2.9 to ,3.8, denoted as region II). The existence of these common regions suggests the presence of comparable form (region I) and structure (region II) factors, respectively the shape of the primary building units of the silica and the geometry of the pores. Contrast variation experiments using dibromomethane to fill pores in the SiO2 matrix showed that scattering was caused by pores rather than silica particles. Electron microscopic analysis confirmed the presence of circular, elliptical, and rectangular pores ranging in size from 3 to 65 nm, determining the structure factor. The fine architecture (length/width ratio of pore diameters) and distribution of the pores, however, seemed to be influenced by environmental factors, such as the salinity of and additions of AlCl3 to the growth medium. The results indicate that diatoms deposit silica with pores <50 nm in size and are highly homologous with respect to geometry. Consequently, it is suggested that in diatoms, whether pennate or centric, the formation of silica at a nanoscale level is a uniform process. [source] Comparison of quantitative and molecular genetic variation of native vs. invasive populations of purple loosestrife (Lythrum salicaria L., Lythraceae)MOLECULAR ECOLOGY, Issue 14 2009YOUNG JIN CHUN Abstract Study of adaptive evolutionary changes in populations of invasive species can be advanced through the joint application of quantitative and population genetic methods. Using purple loosestrife as a model system, we investigated the relative roles of natural selection, genetic drift and gene flow in the invasive process by contrasting phenotypical and neutral genetic differentiation among native European and invasive North American populations (QST , FST analysis). Our results indicate that invasive and native populations harbour comparable levels of amplified fragment length polymorphism variation, a pattern consistent with multiple independent introductions from a diverse European gene pool. However, it was observed that the genetic variation reduced during subsequent invasion, perhaps by founder effects and genetic drift. Comparison of genetically based quantitative trait differentiation (QST) with its expectation under neutrality (FST) revealed no evidence of disruptive selection (QST > FST) or stabilizing selection (QST < FST). One exception was found for only one trait (the number of stems) showing significant sign of stabilizing selection across all populations. This suggests that there are difficulties in distinguishing the effects of nonadaptive population processes and natural selection. Multiple introductions of purple loosestrife may have created a genetic mixture from diverse source populations and increased population genetic diversity, but its link to the adaptive differentiation of invasive North American populations needs further research. [source] Quality variations in transgenic rice with a synthetic cry1Ab gene from Bacillus thuringiensisPLANT BREEDING, Issue 3 2002D. X. Wu Abstract In order to estimate the potential of transgenic rice, characteristics related to grain quality and starch viscosity were investigated in six japonica lines based on three primary transgenic lines containing a synthetic cry1Ab gene from Bacillus thuringiensis. No significant differences were found between the transgenic lines and the wild type, including negative lines and an untransformed line. All six transgenic lines were comparable in size, milling quality, appearance quality and physicochemical properties to the wild type that were derived from. One exception was that the lines derived from the primary transgenic line TR0-101 had smaller grains. Crude protein contents were equivalent in all the material tested, but Cry1Ab protein was only detected in grains of transgenic rice and was undetectable in the cooked rice. The viscosity of the starch differed between the transgenic lines, the wild type and other controls, and two transgenic lines had breakdown values (BDV) and setback values (SBV) similar to the wild type. A positional effect of T-DNA insertion on starch viscosity was found in three primary transgenic lines. [source] Nonaudit Services and Earnings Management: UK Evidence,CONTEMPORARY ACCOUNTING RESEARCH, Issue 4 2004MICHAEL J. FERGUSON Abstract Using a sample of UK firms for the period 1996-98, we provide empirical evidence on the relation between nonaudit services (NAS) purchase and three proxies for earnings management: (1) the likelihood that client firm accounting practices during the sample period were publicly criticized or subject to regulatory investigation; (2) the likelihood that client firms were required to restate prior financial statements or adjust current year results upon adoption of Financial Reporting Standard (FRS) No. 12, which was intended to curb opportunistic use of provisions; and (3) the mean absolute value of client discretionary working capital accruals over the sample period. The level of NAS purchase is measured, alternatively, as (1) the ratio of nonaudit to total auditor fees, (2) the natural log of NAS fees, and (3) the decile rank of a particular client's NAS fees given all NAS fees received by the audit firm practice office. With one exception, we find that all three measures of earnings management are positively and significantly associated with the three measures of NAS purchase. [source] Corporate social responsibility in host countries: a perspective from American managersCORPORATE SOCIAL RESPONSIBILITY AND ENVIRONMENTAL MANAGEMENT, Issue 1 2007Robert L. Engle Abstract This paper examines the beliefs of 56 US-based senior international business executives regarding the importance of multinational corporations' involvement in the improvement of host countries' human rights, poverty, education, health care and environment. The results of this pilot study suggest that all five areas are considered important, with the environmental responsibilities of MNCs being perceived as the most important of these five areas. Little significant difference was found with regards to the executives' views of importance based on either their having lived overseas or based on the international component of their current job activity, with one exception: those executives with more than 50% of their job involving international activities believed that MNCs had a significantly greater environmental responsibility in host countries than did those with less job-related international activity. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment. [source] Differential development of infants at risk for psychopathology: the moderating role of early maternal responsivityDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 5 2001Manfred Laucht PhD The development of behaviour problems in infants born with biological risk (low birthweight) and psychosocial risk (psychosocially disadvantaged family) was studied in a sample of 347 children (171 males, 176 females) at the ages of 2, 4:6, and 8 years. In the search for factors that moderate the effects of early risks, the role of early responsive caregiving was examined. Results indicate that infants at psychosocial risk exhibited both more externalizing and internalizing problems across ages than infants not at psychosocial risk, while no overall differences were apparent between normal-and low-birthweight groups. With one exception, no interactions between biological and psychosocial risk factors emerged, suggesting that their simultaneous effect is largely additive. Maternal responsivity was found to moderate the effects of low birthweight on hyperkinetic and internalizing problems as well as to influence the consequences of family disadvantage on total problems. These findings stress the importance of early parenting in the behavioural development of at-risk children. [source] Changes in estrogenic and androgenic activities at different stages of treatment in wastewater treatment worksENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2002Lucy A. Kirk Abstract Estrogenic and androgenic activities of wastewater were determined during treatment in five wastewater treatment works (WWTWs) in the Untied Kingdom. With one exception, both estrogenic and androgenic activities decreased markedly as wastewater progressed through the plants; removal rates were generally 70% or higher, sometimes reaching 100%. Most of the reduction in activity occurred during secondary (biological) treatment. In both influents and effluents, estrogenic and androgenic activities were appreciably lower in samples collected in August, when the amount of rain had been substantial, compared with samples collected in April and May. Most final effluents contained very low (or nondetectable) estrogenic activity (undetectable to 13 ng/L of estradiol equivalents) and androgenic activity (undetectable to 143 ng/L of dihydrotestosterone [DHT] equivalents), although one (from a WWTW that had only primary treatment) contained relatively high activities (40 ng/L of estradiol equivalents; 4,033 ng/L of DHT equivalents). The type of treatment available at the various WWTWs also affected the activity of the final effluent. The biological significance of these results will depend upon which chemicals contribute to the estrogenic and androgenic activities, because of widely different potencies of different estrogenic chemicals, and on the degree of dilution of the effluents in their receiving waters. [source] The Long-Term Effects of Reconciliation in Japanese Macaques Macaca fuscataETHOLOGY, Issue 11 2001Nicola F. Koyama With one exception, all previous studies of reconciliation in non-human primates (friendly reunion between former opponents) have focused on demonstrating the immediate, short-term effects despite the widely held view that reconciliation has a long-term function of repairing social relationships following aggression. To investigate this long-term function I compared mean interaction rates between opponents during the 10 d following reconciled and non-reconciled conflicts to baseline levels of interaction. Aggression rates during the 10 d after non-reconciled conflicts were significantly higher than the baseline rate, whereas after reconciled conflicts aggression was minimal. Similarly, grooming, proximity and approach rates during the 10 d after non-reconciled conflicts were significantly lower than the baseline rate whereas grooming, proximity and approach rates in the 10 d after reconciled conflicts were restored to baseline levels. These results indicate that there are consequences to not reconciling with a former opponent and highlight the fact that these may be costly in terms of increased risk of long-term aggression and reduced affiliation. The data support predictions from the Relationship-Repair Hypothesis suggesting that reconciliation functions as a mechanism for the repair of social relationships damaged by aggression. [source] Changes In Rhesus Macaque ,Coo' Vocalizations during Early DevelopmentETHOLOGY, Issue 10 2000Kurt Hammerschmidt In order to test whether ,coo' calls of young rhesus macaques, Macaca mulatta, undergo some modifications during early development, and to explore which factors may influence these changes, we studied the ontogeny of their contact call, the ,coo' call. Vocalizations were recorded during brief periods of social separation. Infants were either raised with their mothers and other conspecifics, or separated from their mothers at birth and housed in a nursery with other infants. We recorded calls uttered in the separation context from 20 infants. We digitized the first 50 calls of a given series and subjected them to a Fourier transform. From each frequency,time spectrum, we extracted 65 acoustic parameters using a software program (LMA 5.9). We then used a cluster analysis to separate the ,coo' calls from other call types. With increasing age, the ,coos' dropped in pitch and became more even. The course of amplitude became more constant and the call duration increased slightly. Nevertheless, we found a high intra-individual variation throughout the 5 mo. Neither rearing condition nor sex had any apparent influence on age-related changes in ,coo' structure. With one exception, all parameters that correlated with age could be explained by variation in weight. Therefore, we conclude that growth is the main factor accounting for the observed changes. [source] IL-7 inhibits dexamethasone-induced apoptosis via Akt/PKB in mature, peripheral T cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 4 2003Hadassah Sade Abstract We have investigated the mechanism of IL-7-mediated inhibition of dexamethasone-induced apoptosis in T cells. Broad-spectrum caspase inhibitors block dexamethasone-triggered nuclear fragmentation, but not the loss of mitochondrial transmembrane potential or membrane integrity in CD3+ mature T cells isolated from adult mouse spleens. IL-7 blocked dexamethasone-induced apoptosis and the processing of caspase-3 and caspase-7. IL-7 also blocked dexamethasone-triggered dephosphorylation of the serine-threonine kinase Akt/PKB and its target, the Ser136 residue in Bad. The loss of anti-apoptotic proteins Bcl-xL and inhibitor of apoptosis protein-2 (IAP-2) was also blocked by IL-7. The protective effect was attenuated by pharmacological inhibitors of phosphatidylinositol-3 kinase (PI3K) with one exception: inhibition of PI3K did not abrogate Bcl-xL expression in the presence of IL-7. The anti-apoptotic role of Akt suggested by these experiments was tested by overexpression of constitutively active Akt, which blocked dexamethasone-induced apoptosis and elevated IAP-2 but not Bcl-xL levels in a mature T cell line. Thus, IL-7 regulates IAP-2 expression and inhibits dexamethasone-induced apoptosis by activating Akt via PI3K-dependent signaling, but regulates Bcl-xL expression via a PI3K-independent pathway in mature T cells. [source] WARNING DISPLAYS IN SPINY ANIMALS: ONE (MORE) EVOLUTIONARY ROUTE TO APOSEMATISMEVOLUTION, Issue 12 2005Michael P. Speed Abstract To date, theoretical or laboratory simulations of aposematic evolution in prey animals have focused narrowly on internally stored chemical defense as the source of unprofitability and ignore aposematic advertisement of physical defenses such as spines (and defensive hairs, claws, etc.). This has occurred even though aposematism in spiny animals has been recognized since the 19th century. In this paper we present the first detailed theoretical consideration of aposematism in spiny animals, focusing on questions of initial evolution, costs of display, and coevolution of displays with defenses. Using an individual-based evolutionary model, we found that spines (or similar physical defenses) can easily evolve without aposematism, but when spines do evolve, aposematic displays can also easily evolve if they help to make the prey animal distinctive and if they draw attention to the physical threat. When aposematic displays evolve, they cause reduced investment in costly spines, so that, in addition to signaling unprofitability, aposematic display may enhance the cost-effectiveness of antipredator defenses (one exception to this conclusion is if the display is itself as costly as the defense). For animals with stinging spines, combining physical and chemical defense, the evolution of aposematic display may lead to reduced investment in the toxin compared to the spine. This occurs because spines act as both secondary (repellent) defenses and as primary defenses (their own visible, honest advertisement), whereas internally stored toxins only (generally) act as repellent secondary defenses. We argue that conspicuous aposematism in spines functions as an attention-getting mechanism, whereas conspicuous aposematic display in purely toxic animals may be explained by signal reliability arguments. Finally, one (more) route by which aposematism may initially evolve is by spiny rather than purely chemically defended species, spreading to species with other forms of secondary defense as the signal becomes common. [source] Structure and diversity of Gram-negative sulfate-reducing bacteria on rice rootsFEMS MICROBIOLOGY ECOLOGY, Issue 2-3 2001Daniel Scheid Abstract Specific PCR assays were used to amplify the 16S rRNA genes of the Desulfobacteriaceae and the Desulfovibrionaceae from extracted environmental DNA from rice roots. 16S rDNA-based community patterns of the Desulfobacteriaceae were generated via terminal restriction fragment length polymorphism analysis from rice roots and compared with bulk soil. The molecular fingerprints showed no significant difference between rice roots and bulk soil, but changes during the vegetation period. 16S rDNA clone libraries and sequencing showed that the predominant terminal restriction fragments represented distinct phylogenetic groups. The 16S rDNA clone sequences of the Desulfobacteriaceae fell in the phylogenetic radiation of Desulfonema and Desulfosarcina or grouped within the Desulforhabdus,Syntrophobacter assemblage. Three of the latter sequences were closely affiliated with the MPN isolate EZ-2C2 from rice roots. All Desulfovibrionaceae 16S rDNA clone sequences, with one exception, were affiliated with the MPN isolate F1-7b from rice roots. The clustering of the clone sequences and the close phylogenetic affiliation with isolates from MPN enrichments from the same habitat in two cases indicated that these sequence clusters may represent predominant Gram-negative sulfate reducers on rice roots. Quantification of the bacterial abundances was accomplished by rRNA dot blot hybridization. In total the Gram-negative sulfate reducers accounted for approximately 2,3% of the total rRNA content. The relative rRNA abundance of the Desulfobacteriaceae was, at 1.4%, higher than that of the Desulfovibrionaceae (0.5%). [source] Local disturbance history affects patchiness of benthic river algaeFRESHWATER BIOLOGY, Issue 9 2003Christoph D. Matthaei Summary 1.,Recent research has shown that high-flow events in streams leave a small-scale mosaic of bed patches that have experienced scouring, sediment deposition (fill), or remained stable. Few studies have investigated if this ,local disturbance history' contributes to the patchy distribution of benthic organisms in streams and rivers. 2.,In the present research, we demonstrate that local disturbance history in a mid-sized river can have both short- and long-term effects on epilithic algae. Chains buried vertically in the substratum of the river bed (236 in a 800-m reach) indicated that two floods (return periods ,1 year) caused a mosaic of bed patches with different disturbance histories. Once after the first and twice after the second flood, we sampled epilithic algae (mainly diatoms) in replicate patches that had been scoured, filled, or remained stable during the respective event. Algal biomass and cell density per substratum area were determined. 3.,Three months after the first flood, algal biomass, total diatom density, diatom taxon richness, and densities of six of nine most common taxa were highest in fill patches. Six days after the second flood, biomass was highest in stable patches, indicating a refugium function of these patches. The refugium patches consisted of average-sized stones, in contrast to previous studies of flood refugia for benthic algae in which these refugia were always large and/or immobile substrata. Four weeks after the second flood, diatoms tended to be most abundant in scour patches. With one exception, these differences between patch types could not be attributed to differences in local near-bed current velocity or water depth. 4.,The effects of disturbance history were more complex than a simple refugium function of stable patches because algal patterns changed with time since the last disturbance, possibly depending on the successional state of the algal mats. [source] A Family of Location Models for Multiple-Type Discrete DispersionGEOGRAPHICAL ANALYSIS, Issue 3 2006Kevin M. Curtin One of the defining objectives in location science is to maximize dispersion. Facilities can be dispersed for a wide variety of purposes, including attempts to optimize competitive market advantage, disperse negative impacts, and optimize security. With one exception, all of the extant dispersion models consider only one type of facility, and ignore problems where multiple types of facilities must be located. We provide examples where multiple-type dispersion is appropriate and based on this develop a general class of facility location problems that optimize multiple-type dispersion. This family of models expands on the previously formulated definitions of dispersion for single types of facilities, by allowing the interactions among different types of facilities to determine the extent to which they will be spatially dispersed. We provide a set of integer-linear programming formulations for the principal models of this class and suggest a methodology for intelligent constraint elimination. We also present results of solving a range of multiple-type dispersion problems optimally and demonstrate that only the smallest versions of such problems can be solved in a reasonable amount of computer time using general-purpose optimization software. We conclude that the family of multiple-type dispersion models provides a more comprehensive, flexible, and realistic framework for locating facilities where weighted distances should be maximized, when compared with the special case of locating only a single type of facility. [source] Controls on old and new water contributions to stream flow at some nested catchments in Vermont, USAHYDROLOGICAL PROCESSES, Issue 3 2002James B. Shanley Abstract Factors controlling the partitioning of old and new water contributions to stream flow were investigated for three events in four catchments (three of which were nested) at Sleepers River Research Watershed in Danville, Vermont. In the 1993 snowmelt period, two-component isotopic hydrograph separations showed that new water (meltwater) inputs to the stream ranged widely from 41 to 74%, and increased with catchment size (41 to 11 125 ha) (with one exception) and with open land cover (0,73%). Peak dissolved organic carbon concentrations and relative alkalinity dilution in stream water ranked in the same order among catchments as the new water fractions, suggesting that new water followed shallow flow paths. During the 1994 snowmelt, despite similar timing and magnitude of melt inputs, the new-water contribution to stream flow ranged only from 30 to 36% in the four catchments. We conclude that the uncommonly high and variable new water fractions in streamwater during the 1993 melt were caused by direct runoff of meltwater over frozen ground, which was prevalent in open land areas during the 1993 winter. In a high-intensity summer rainstorm in 1993, new water fractions were smaller relative to the 1993 snowmelt, ranging from 28 to 46%, but they ranked in the identical catchment order. Reconciliation of the contrasting patterns of new,old water partitioning in the three events appears to require an explanation that invokes multiple processes and effects, including: 1.topographically controlled increase in surface-saturated area with increasing catchment size; 2.direct runoff over frozen ground; 3.low infiltration in agriculturally compacted soils; 4.differences in soil transmissivity, which may be more relevant under dry antecedent conditions. These data highlight some of the difficulties faced by catchment hydrologists in formulating a theory of runoff generation at varying basin scales. Copyright © 2002 John Wiley & Sons, Ltd. [source] A study into the plaque-inhibitory activity of experimental toothpaste formulations containing antimicrobial agentsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 8 2005J. Moran Abstract Background/Aims: The use of specific antimicrobial agents in toothpastes may help reduce plaque and gingivitis. There would also appear to be some value in formulating products that contain combinations of such agents that may potentiate any activity present. The aims of this exploratory and pragmatic study were twofold:- (1) exploratory: to compare the effects on plaque re-growth of two zinc citrate/triclosan formulations, one of which contained bromochlorophene and hence demonstrate any additional beneficial effects produced by the addition of the phenol. (2) pragmatic: to assess whether both pastes were significantly better than a benchmark control, proprietary fluoride toothpaste at inhibiting plaque formation. Methods: Following an initial prophylaxis to remove all plaque and calculus, toothpaste slurry rinses were used over a 96 h period by 24 volunteers, while omitting all other oral hygiene procedures. After 24, 48 and 96 h, plaque was measured by plaque area and by plaque index. For comparative purposes, a conventional commercial fluoride toothpaste rinse was also used as a benchmark control in this triple cross-over double-blind study. Results: With one exception, comparisons between the three pastes failed to show any significant differences in plaque accumulation at 96 h whether assessed by plaque index or area. At this time period, significantly more plaque was seen with the zinc citrate paste without bromochlorophene, compared with that of the control paste. Conclusions: The findings from this study failed to demonstrate a plaque-inhibitory action from the two novel formulations beyond that of a conventional benchmark toothpaste, although overall levels of plaque formed by the volunteers, especially on the control paste were generally lower than in previous studies. Nevertheless, it remains to be determined whether the test formulations could exert a direct anti-inflammatory action against gingivitis by way of the triclosan delivery system. Neither test formulation was subsequently marketed. [source] Histopathological observations of human periimplantitis lesionsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 5 2004Tord Berglundh Abstract Objective: The aim of the present study was to analyze some characteristics of advanced and progressive periimplantitis lesions in man. Material and methods: Soft tissue biopsies were obtained from 12 implants in six patients. The implants had been in function between 4 and 21 years and were, with one exception, located in the maxilla. The radiographic examination performed prior to biopsy revealed that all sites exhibited advanced bone loss. Further, clinical signs of severe inflammation, such as suppuration, swelling and/or fistula formation were detected in the majority of sites and seven of the 12 implants were found to be mobile at biopsy. Each biopsy was following fixation embedded in epoxy resin and sections were prepared for histometric and morphometric analysis. Results and conclusion: It was demonstrated (i) that all soft tissue units harbored large inflammatory cell infiltrates (ICT) that extended to a position apical of a pocket epithelium and (ii) that about 60% of the lesions were occupied by inflammatory cells, among which plasma cells dominated. Numerous amounts of PMN cells occurred not only in the pocket epithelium and adjacent connective tissue areas, but were also present in peri-vascular compartments in more central areas of the ICT. [source] Experimental and CFD studies of fluid dynamic gauging in annular flowsAICHE JOURNAL, Issue 8 2009T. Gu Abstract Fluid dynamic gauging has been applied for the first time to measurements on a curved surface, specifically the inner convex surface of an annulus. Two hydraulic cases were examined: (i) the quasi-static case, where there is no flow in the annulus, other than the flow imposed by the working action of the gauge and (ii) the turbulent case, where there is additionally a forced advective flow in the turbulent regime (14,000 < Reannulus < 32,000). The nozzle clearance,flow rate characteristics resembled those reported previously for flat geometries, with one exception; at small clearance values (0 < h/dt < 0.1), flow rate was found to be independent of clearance because of a leakage flow arising from the curvature of the surface. The experimental results for the quasi-static case showed very good agreement with simulations of the configuration using computational fluid dynamics (CFD). The agreement indicates that the technique may be used not only for measuring the thickness of deposits on curved surfaces, but also for measuring their strength. CFD simulation of the turbulent case was not attempted, but the experimental results imply that the technique could be used reliably as a real-time in situ thickness sensor for this scenario, which is often employed in laboratory fouling studies. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] SEAWEED ABUNDANCE AND DIVERSITY IN HIGH ENERGY AND LOW ENERGY AREAS AT PORT ARANSAS, TEXAS JETTIESJOURNAL OF PHYCOLOGY, Issue 3 2001Article first published online: 24 SEP 200 Agan, J. C. & Lehman, R. L. Department of Physical and Life Sciences, Texas A&M University-Corpus Christi 6300 Ocean Dr., Corpus Christi, TX 78412 USA Benthic algal sampling from high and low energy zones at a selected site on the south jetty at Port Aransas, Texas was completed between April 1999 and February 2000. Species composition and seasonal periodicity in relation to temperature and salinity fluctuations were determined. Dominant plants throughout the year included Bryocladia cuspidata, Bryocladia thyrsigera, Gelidium pusillum, Centroceras clavulatum, Ulva fasciata, and Padina gymnospora. The Rhodophyta dominated species coverage, along with biomass accumulation, although Chlorophyta species accrued the greatest biomass on the high energy side in April and June sampling. Chlorophyta are important to benthic coverage and biomass in the shallowest of waters, despite being fewer in species richness. Phaeophyta species including Petalonia fascia, Hincksia mitchelliae, and Ectocarpus siliculosus were found only during the cooler months. Padina gymnospora was the one exception as it was collected year-round. Results indicate that a greater Rhodophyta abundance was found on the channel side (low energy), where as, the surf side (high energy) contained a greater Chlorophyta abundance. Phaeophyta abundance for both high and low energy sites were comparable possibly due to the greater depth of water in which they are located. Little variance occurred in average biomass accumulation throughout the year. Highest biomass was in August (216.613g dry weight) with lowest occurring in April (107.4205g dry weight). [source] SEAWEED ABUNDANCE AND DIVERSITY IN HIGH ENERGY AND LOW ENERGY AREAS AT PORT ARANSAS, TEXAS JETTIESJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 9 OCT 200 Agan, J. C. & Lehman, R. L. Department of Physical and Life Sciences, Texas A&M University-Corpus Christi 6300 Ocean Dr., Corpus Christi, TX 78412 USA Benthic algal sampling from high and low energy zones at a selected site on the south jetty at Port Aransas, Texas was completed between April 1999 and February 2000. Species composition and seasonal periodicity in relation to temperature and salinity fluctuations were determined. Dominant plants throughout the year included Bryocladia cuspidata, Bryocladia thyrsigera, Gelidium pusillum, Centroceras clavulatum, Ulva fasciata, and Padina gymnospora. The Rhodophyta dominated species coverage, along with biomass accumulation, although Chlorophyta species accrued the greatest biomass on the high energy side in April and June sampling. Chlorophyta are important to benthic coverage and biomass in the shallowest of waters, despite being fewer in species richness. Phaeophyta species including Petalonia fascia, Hincksia mitchelliae, and Ectocarpus siliculosus were found only during the cooler months. Padina gymnospora was the one exception as it was collected year-round. Results indicate that a greater Rhodophyta abundance was found on the channel side (low energy), where as, the surf side (high energy) contained a greater Chlorophyta abundance. Phaeophyta abundance for both high and low energy sites were comparable possibly due to the greater depth of water in which they are located. Little variance occurred in average biomass accumulation throughout the year. Highest biomass was in August (216.613g dry weight) with lowest occurring in April (107.4205g dry weight). [source] Geochemistry, dispersal, volumes and chronology of Holocene silicic tephra layers from the Katla volcanic system, IcelandJOURNAL OF QUATERNARY SCIENCE, Issue 2 2001Gudrún Larsen Abstract At least 12 silicic tephra layers (SILK tephras) erupted between ca. 6600 and ca. 1675 yr BP from the Katla volcanic system, have been identified in southern Iceland. In addition to providing significant new knowledge on the Holocene volcanism of the Katla system which typically produces basaltic tephra, the SILK tephras form distinct and precise isochronous marker horizons in a climatically sensitive location close to both the atmospheric and marine polar fronts. With one exception the SILK tephras have a narrow compositional range, with SiO2 between 63 and 67%. Geochemically they are indistinguishable from ocean transported pumice found on beaches in the North Atlantic region, although they differ significantly from the silicic component of the North Atlantic Ash Zone One (NAAZO). Volumes of airborne SILK tephra range from 0.05 to 0.3 km3. We present new isopach maps of the six largest layers and demonstrate that they originate within the Katla caldera. The apparently stable magma system conditions that produced the SILK tephras may have been established as a consequence of the eruption of the silicic component of NAAZO (ca. 10.3 ka) and disrupted by another large-scale event, the tenth century ad Eldgjá eruption (ca. 1 ka). Despite the current long repose, silicic activity of this type may occur again in the future, presenting hitherto unknown hazards. Copyright © 2001 John Wiley & Sons, Ltd. [source] Outcome Expectancies and Risk Behaviors in Maltreated AdolescentsJOURNAL OF RESEARCH ON ADOLESCENCE, Issue 2 2006Patrick Nickoletti This study examined positive and negative outcome expectancies for risk behaviors, and their association with engagement in risk behaviors, in a sample of 149 maltreated adolescents. "Outcome Expectancies" are evaluative social cognitions about what will occur as a consequence of one's actions. Risk behaviors and outcome expectancies for substance use, sexual behavior, and delinquency were assessed. In all regression models, positive expectancies were significantly related to risk behaviors while negative expectancies, with one exception, were not significantly related. In three of four regression models, significant interactions were found between positive and negative expectancies in predicting risk behaviors. The nature of the interaction differed by type of risk behavior. Beyond demonstrating associations between outcome expectancies and risk behaviors in a maltreated sample, this paper contributes to the study of social information processing by demonstrating significant interactions between positive and negative expectancies. [source] HPLC-MS of anthraquinoids, flavonoids, and their degradation products in analysis of natural dyes in archeological objectsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 13 2007Izabella Surowiec Abstract LC with MS detection was optimized for sensitive and selective analysis of main classes of natural dyes used in ancient times for dyeing textiles , red anthraquinoids, yellow flavonoids, and known degradation products of flavonols , hydroxybenzoic acids. Fragmentation patterns of both negative and positive molecular ions for the above mentioned compounds were investigated. Three acquisition modes of MS analysis: scanning, SIM, and multiple reaction monitoring (MRM) in both positive and negative ion modes were optimized and compared with each other and with the UV-Vis diode-array detection. Even though in the applied chromatographic system formic acid was used in the mobile phase, SIM in the negative ion mode was the most selective and sensitive detection for all the investigated compounds when both mixtures of standards and analysis of extracts from archeological samples were concerned, with one exception , alizarin, for which MS detection in positive ion mode was more sensitive. Detection limits obtained with MS detection for all investigated compounds except quinizarin were lower than the ones obtained with the diode-array UV-Vis detection, making MS detection the most suitable tool for the analysis of natural dyes and their degradation products in extracts from archeological samples. [source] Thermodynamically Stable SiwCxNyOz Polymer-Like, Amorphous Ceramics Made from Organic PrecursorsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2008Riham M. Morcos This communication reports new results on the enthalpy of formation of pseudo-amorphous ceramic compounds constituted from silicon, carbon, oxygen, and nitrogen (SiCNO), made from the polymer route. Again, like the SiCO materials, although with one exception, the enthalpy of formation from crystalline components (SiO2 cristobalite, ,-Si3N4, SiC, and excess C) is negative. Some of the alloyed oxygen,nitrogen compositions yield enthalpies that are much more negative (,100 kJ/g·atom) in comparison with compositions that contain mainly oxygen or nitrogen (,20 kJ/g·atom). The exception, having a N/O ratio near 2, has a positive value for the enthalpy. This may reflect the presence of nanoclusters of stoichiometric Si2N2O instead of the pseudo-amorphous nanodomain structure seen for the other samples. [source] Seeing other women breastfeed: how vicarious experience relates to breastfeeding intention and behaviourMATERNAL & CHILD NUTRITION, Issue 2 2010Pat Hoddinott Abstract Vicarious experience gained through seeing women breastfeed may influence infant feeding decisions and self-efficacy. Our aim was to measure the attributes of seeing breastfeeding and to investigate how these relate to feeding intention (primary outcome) and behaviour (secondary outcome). First, we developed a Seeing Breastfeeding Scale (SBS), which consisted of five attitudes (Cronbach's alpha of 0.86) to most recently observed breastfeeding: ,I felt embarrassed'; ,I felt uncomfortable'; ,I did not know where to look'; and ,It was lovely' and ,It didn't bother me'. Test,retest reliability showed agreement (with one exception, kappas ranged from 0.36 to 0.71). Second, we conducted a longitudinal survey of 418 consecutive pregnant women in rural Scotland. We selected the 259 women who had never breastfed before for further analysis. Following multiple adjustments, women who agreed that ,It was lovely to see her breastfeed' were more than six times more likely to intend to breastfeed compared with women who disagreed with the statement [odds ratio (OR) 6.72, 95% confidence interval (CI) 2.85,15.82]. Women who completed their full-time education aged 17 (OR 3.09, 95% CI 1.41,6.77) or aged 19 (OR 7.41 95% CI 2.51,21.94) were more likely to initiate breastfeeding. Women who reported seeing breastfeeding within the preceding 12 months were significantly more likely to agree with the statement ,It was lovely to see her breastfeed' (P = 0.02). Positive attitudes to recently seen breastfeeding are more important determinants of feeding intention than age of first seeing breastfeeding, the relationship to the person seen and seeing breastfeeding in the media. [source] Isotopic compositions of different presolar silicon carbide size fractions from the Murchison meteoriteMETEORITICS & PLANETARY SCIENCE, Issue 5 2000Sachiko AMARI Ratios of 12C/13C range from 37 to 42 and 14N/15N ratios from 370 to 520, within the range of single-grain measurements on coarser samples and in agreement with an asymptotic giant branch (AGB) star origin of most of the grains. Variations among size fractions do not show any simple trend and can be explained by varying contamination with isotopically normal material. Silicon isotopic ratios vary only little and, with one exception, lie to the right of the singlegrain mainstream correlation line. This might indicate a higher percentage of the minor populations Y and Z among finer grain-size fractions. All bulk samples have large 26Mg excesses attributed to the presence of short-lived 26Al at the time of grain formation. Inferred 26Al/27Al ratios are much larger than those measured in single larger mainstream grains. This is probably because of the presence of SiC grains of type X; we obtain an estimate of 0.4 for their 26Al/27Al ratio. Our Ca-isotopic measurements, the first made on presolar SiC grains, show excesses in 42Ca and 43Ca, which is in general agreement with theoretical expectations for AGB stars. Calcium-44 excesses are much larger than expected and are probably because of X grains, which have high44Ca excesses because of the decay of short-lived 44Ti produced in supernova explosions. We arrive at an estimate of 0.014 for the initial 44Ti/48Ti ratio of the X grains, within the range obtained from previous single X grain measurements. The Ti-isotopic ratios of the bulk samples show a V-shaped pattern with excesses of all isotopes relative to 48Ti. Isotopes 46Ti, 47Ti, and 50Ti show excesses relative to the correlation between Ti and Si ratios for single grains and are in general agreement with theoretical models of s-process nucleosynthesis in AGB stars. In contrast, 49Ti does not show any excess relative to the singlegrain data; it also fails to agree with theory, which predicts much larger excesses than observed. Measured 53Cr/52Cr and 57Fe/56Fe ratios are normal within errors. The first result is expected even for Cr in AGB star envelopes, but the second result suggests that most of the Fe analyzed originates from contamination. We have found no simple trends in isotopic composition with respect to grain size that can be interpreted in terms of nucleosynthetic origin, unlike the results for Kr, Xe, Ba, and Sr. [source] Genetic variation and population structure in the endangered greater horseshoe bat Rhinolophus ferrumequinumMOLECULAR ECOLOGY, Issue 8 2000Stephen J. Rossiter Abstract Following a dramatic decline last century, the British population of the endangered greater horseshoe bat Rhinolophus ferrumequinum is highly fragmented. To examine the consequences of fragmentation and limited dispersal on patterns of genetic structure and variation, we used microsatellite markers to screen bats from around 50% of the known maternity colonies in Britain, and two areas from continental Europe. Analyses revealed that Welsh and English colonies were genetically isolated. This, and lower variability in Britain than north France, may result from either genetic drift, or the species' colonization history. Gene flow among most neighbouring colonies was not generally restricted, with one exception. These findings have important implications for the ongoing conservation management of this species. [source] Investigation of the ELAIS field by Vega photometry: absolute magnitude-dependent Galactic model parametersMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2006S. Bilir ABSTRACT We estimate the density laws of the Galactic stellar populations as a function of absolute magnitude in a near-polar Galactic field. The density laws are determined by direct fitting to photometric parallaxes from Vega photometry in the ELAIS field (; epoch 2000), both independently for each population and simultaneously for all stellar populations. Stars have been separated into different populations based on their spatial location. The thick disc and halo are fitted best by an exponential. However, the thin disc is fitted best by using a sech2 law for stars at faint absolute magnitudes [10 < M(g,) , 11, 11 < M(g,) , 12 and 12 < M(g,) , 13], and an exponential law for stars at relatively bright absolute magnitudes [5 < M(g,) , 6, 6 < M(g,) , 7, 7 < M(g,) , 8, 8 < M(g,) , 9 and 9 < M(g,) , 10]. The scaleheights for the sech2 density laws are the equivalent exponential scaleheights. Galactic model parameters are dependent on absolute magnitude. The scaleheight for the thin disc decreases monotonically from stars at bright absolute magnitudes [M(g,) = 5] to stars at faint absolute magnitudes [M(g,) = 13] in the range 363,163 pc, except for the minimum H= 211 pc at 9 < M(g,) , 10 where the sech density law fits better. Its local density is flat at bright absolute magnitudes but increases at faint absolute magnitudes. For the thick disc, the scaleheight is flat within the uncertainties. The local space density of the thick disc relative to the local space density for the thin disc is almost flat in the absolute magnitude intervals 5 < M(g,) , 6 and 6 < M(g,) , 7, 7.59 and 7.41 per cent respectively, whereas it decreases down to 3.31 per cent in the absolute magnitude interval 7 < M(g,) , 8. The axial ratio for the halo is ,= 0.60, 0.73 and 0.78 for the absolute magnitude intervals 4 < M(g,) , 5, 5 < M(g,) , 6 and 6 < M(g,) , 7 respectively, and its local space density relative to the local space density for the thin disc is 0.06 and 0.04 per cent for the intervals 5 < M(g,) , 6 and 6 < M(g,) , 7, respectively [the local space density relative to the thin disc could not be derived for the absolute magnitude interval 4 < M(g,) , 5 owing to a lack of the local space density for the thin disc for this interval]. The simultaneous fit of all three stellar populations agrees within uncertainties with the most recent values in the literature. Also, each parameter is close to one of the corresponding parameters estimated for different absolute magnitude intervals in this work, but with one exception: i.e. the scaleheight for the thick disc is relatively small and its error is rather large (H= 760+62,55 pc). [source] Oral and Maxillofacial Pathology: Bcl-2 expression in sequential biopsies of potentially malignant oral mucosal lesions assessed by immunocytochemistryORAL DISEASES, Issue 5 2000RL McAlinden OBJECTIVE: To examine, for the first time Bcl-2 expression in sequential (autogenous) oral mucosal biopsies taken from the same sites in a gender, risk-factor matched, Caucasoid sample, over a 21-year period. DESIGN: Retrospective immunocytochemical longitudinal study of archival serial biopsies. MATERIALS AND METHODS: Computer records were used to identify biopsy specimens derived from 12 patients. These were divided into four groups: (1) Histologically innocuous lesions which remained histologically innocuous. (2) Dysplastic lesions which remained dysplastic. (3) Histologically innocuous lesions which later progressed to squamous cell carcinoma (SCC). (4) Dysplastic lesions which later progressed to SCC. This represented 65 biopsies in total. Bcl-2 expression was studied using mouse antihuman BCL-2 oncoprotein clone 124 (Dako, Denmark). RESULTS: Generally, there was a lack of Bcl-2 immuno-reactivity in the epithelium, with one exception in dysplastic epithelium from a group (3) patient. CONCLUSION: These findings suggest that in our series, Bcl-2 is not expressed early in oral premalignant lesions and appears to contradict previous reports. Possible explanations for this disparity are considered. [source] Topiramate for smoking cessationPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 3 2006YASSER KHAZAAL md Abstract Due to its AMPA (,-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid)/kainate antagonism, topiramate would be particularly interesting in addiction treatment. Flexible-dose topiramate was prescribed to 13 smokers (10 smokers who wanted to stop smoking, and three who received topiramate for other reasons). Six out of 13 smokers were abstinent at 2 months and two more subjects had reduced their cigarette consumption by >50%. With one exception, temporary reduction of the number of smoked cigarettes preceded definitive abstinence at month 2. Three more subjects who achieved a momentary reduction had, however, to interrupt the treatment due to intolerable side-effects. Controlled trials are needed to confirm these preliminary observations. [source] | |||||||||||||||||||||||||||||||||||||