Cortactin recruitment by enterohemorrhagic Escherichia coli O157:H7 during infection in vitro and ex vivo

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important human pathogen that colonizes the gut mucosa via attaching and effacing (A/E) lesions; A/E lesion formation in vivo and ex vivo is dependent on the type III secretion system (T3SS) effector Tir. Infection of cultured cells by EHEC leads to induction of localized actin polymerization, which is dependent on Tir and a second T3SS effector protein, TccP, also known as EspF(U). Recently, cortactin was shown to bind both the N terminus of Tir and TccP via its SH3 domain and to play a role in EHEC-triggered actin polymerization in vitro. In this study, we investigated the recruitment of cortactin to the site of EHEC adhesion during infection of in vitro-cultured cells and mucosal surfaces ex vivo (using human terminal ileal in vitro organ cultures [IVOC]). We have shown that cortactin is recruited to the site of EHEC adhesion in vitro downstream of TccP and N-WASP. Deletion of the entire N terminus of Tir or replacing the N-terminal polyproline region with alanines did not abrogate actin polymerization or cortactin recruitment. In contrast, recruitment of cortactin to the site of EHEC adhesion in IVOC is TccP independent. These results imply that cortactin is recruited to the site of EHEC adhesion in vitro and ex vivo by different mechanisms and suggest that cortactin might have a role during EHEC infection of mucosal surfaces.

’Letting the right one in’: provider contexts for recruitment to initial teacher education in the United Kingdom

We exploit policy differences within the UK to investigate provider context and recruitment to initial teacher education (ITE). We identify three dimensions of variation: conceptions of professionalism, universal or context specific preparation and costs and benefits to providers. University-led ITE programmes used similar criteria and processes in each jurisdiction, but there were differences between university-led and school-led recruitment. Our study suggests that the current shortfall in recruitment to ITE in England may be a product of the contextual constraints which schools experience. It also suggests that school-led recruitment may tend to emphasise short-term and school-specific needs.

Pileated Woodpecker Occupancy and the Occurrence and Recruitment of Key Habitat Attributes in a Managed Forest

Thesis (Master's)--University of Washington, 2016-08

Ancient clam gardens, traditional management portfolios, and the resilience of coupled human-ocean systems

Indigenous communities have actively managed their environments for millennia using a diversity of resource use and conservation strategies. Clam gardens, ancient rock-walled intertidal beach terraces, represent one example of an early mariculture technology that may have been used to improve food security and confer resilience to coupled human-ocean systems. We surveyed a coastal landscape for evidence of past resource use and management to gain insight into ancient resource stewardship practices on the central coast of British Columbia, Canada. We found that clam gardens are embedded within a diverse portfolio of resource use and management strategies and were likely one component of a larger, complex resource management system. We compared clam diversity, density, recruitment, and biomass in three clam gardens and three unmodified nonwalled beaches. Evidence suggests that butter clams (Saxidomus gigantea) had 1.96 times the biomass and 2.44 times the density in clam gardens relative to unmodified beaches. This was due to a reduction in beach slope and thus an increase in the optimal tidal range where clams grow and survive best. The most pronounced differences in butter clam density between nonwalled beaches and clam gardens were found at high tidal elevations at the top of the beach. Finally, clam recruits (0.5-2 mm in length) tended to be greater in clam gardens compared to nonwalled beaches and may be attributed to the addition of shell hash by ancient people, which remains on the landscape today. As part of a broader social-ecological system, clam garden sites were among several modifications made by humans that collectively may have conferred resilience to past communities by providing reliable and diverse access to food resources.

Postdigital play and the aesthetics of recruitment

This paper analyses reconfigurations of play in newly emergent material and digital configurations of game design. It extends recent work examining dimensions of hybridity in playful products by turning attention to interfaces, practices and spaces, rather than devices. We argue that the concept of hybrid play relies on predefining clear and distinct entities that then enter into hybrid situations. Drawing on concepts of the ‘interface’ and ‘postdigital’, we argue the distribution of computing devices creates difficulties for such presuppositions. Instead, we propose an ‘aesthetic of recruitment’ that is adequate to the new openness of social and technical play.

Nutrient fluxes on an intertidal mudflat in Marennes-Oleron Bay, and influence of the emersion period

Fluxes of nutrients (NH sub(4) super(+), NO sub(3) super(-), PO sub(4) super(3-) and Si(OH) sub(4)) were studied on an intertidal mudflat in Marennes-Oleron Bay, France, at two different seasons and at different times of the emersion period. Fluxes through the sediment-water interface were both calculated from vertical profiles of nutrient concentration in pore-water (diffusive fluxes, JD) and measured in light and dark benthic mini-chambers (measured fluxes, J sub(0)). Results indicate that ammonia was mainly released in summer while nitrate was mainly taken up in late winter. This uptake from the overlying water was probably due to the coupling of nitrification-denitrification within the sediment. The J sub(0) /J sub(D) ratio further indicates that bioturbation likely enhanced ammonia release in summer. Concerning phosphate, the comparison of diffusive and measured fluxes suggests that PO sub(4) super(3-) could be assimilated by the biofilm in winter while it was released in summer at a high rate due to both bioturbation and desorption because of the relative summer anoxic conditions. Silica was always released by the sediment, but at a higher rate in summer. Statistically significant differences in measured fluxes were detected in dark chambers at different times of low tide, thus suggesting a short-term variability of fluxes. Microphytobenthos preferred ammonia to nitrate, but assimilated nitrate when ammonia was not available. It also turned out that benthic cells could be limited in nitrogen during low tide in late winter. In summer, ammonia was not limiting and microphytobenthic activity significantly decreased the measured flux of NH sub(4) super(+) in the middle of low tide when its photosynthetic capacity was highest.

Investigation on reproduction process in two species of crab Eriphia sebana and Ocypode saratan in the intertidal zone of Chabahar area

The present study with headline investigation on reproduction in two species of Crab Eriphia sebana and Ocypode saratan was carried out in the intertidal zone of Chabahar in thirteen month from December 2004 to December 2005. Checked samplings have been taken, 45 number Crab monthly from any four stations by manual or use trap. During this study the following subjects were measured: Temperature range and salinity, Measurable coast granule, Determination of sex ratio, Relations carapace width with carapace length, Carapace width with total body weight, Gonad weight, gonadosomatic index, condition factor, gastrosomatic index, investigation content in stomach, LM50, Growth parameters, plenty distribution length and width and gonad weight and total body weight. Studied on measurable coast granule were expressed that Ocypode saratan in Desalination station, were nest in soils equable sand and this quantity were confirmed in Pozm station. Sex ratio were assign in desalination area and Pozm M: F 0/44:0/56 and in Tiss and Chabahar M: F 0/45:0/55. Carapace length and carapace width (cm) and body weight (g) Furthest were designated in Ocypode saratan within carapace width sequential: female: 5/42-6/15-105/13 and male: 5/53-6/25-108/91 and in Eriphia sebana within Tiss area sequential: female: 5/12-5/94-110/21 and male 5/14-60/01-114/37. Have been linear relationship between carapace length and carapace width and equaled CW = a CL + b. Weight growth in two species were be modal and equaled BW= aCLb and increased Crab weight by built up carapace width. Maximum gonad weight in Ocypode saratan within desalination area in female have been outcome 3/39 and in male 0/84g and in Eriphia sebana extreme within Tiss during may in female were be 4/18 and in male 1/1g. Stomach content in Eriphia sebana were involved a black until half-purplish liquid and yellowish in Ocypode saratan. Stomach contents identifiable were being in four groups: Molluscoid, Crustacean, Plankton and Fish. Carapace width during the first year of maturation have been LM50:3/77 in Desalination area and LM50:3/92 in Pozm for Ocypode saratan and LM50:4/26 in Tiss and LM50:4/62 in Chabahar. Ability spawning in Eriphia sebana within Tiss has been CW=4/17cm and in Ocypode saratan within Desalination area CW=4/23cm. Maximun value of Loo for Eriphia sebana was equal 59/67 and growth factor K=0/68 within Tiss and Loo =61/64 , K=0/65 for Ocypode saratan within Desalination area. Maximun GSI and GI have been within Desalination area and Tiss and minimum within Pozm and Chabahar. The maturity stages of two species were classifed into six stages. Review on GSI, CF have been showed that relation with temperature and salinity and definer in two species have been spawned in two period that Maximun in spring premier than autumn.

Spatial and temporal interaction between sediment and microphytobenthos in a temperate estuarine macro-intertidal bay

Intertidal flats of the estuarine macro-intertidal Baie des Veys (France) were investigated to identify spatial features of sediment and microphytobenthos (MPB) in April 2003. Gradients occurred within the domain, and patches were identified close to vegetated areas or within the oyster-farming areas where calm physical conditions and biodeposition altered the sediment and MPB landscapes. Spatial patterns of chl a content were explained primarily by the influence of sediment features, while bed elevation and compaction brought only minor insights into MPB distribution regulation. The smaller size of MPB patches compared to silt patches revealed the interplay between physical structure defining the sediment landscape, the biotic patches that they contain, and that median grain-size is the most important parameter in explaining the spatial pattern of MPB. Small-scale temporal dynamics of sediment chl a content and grain-size distribution were surveyed in parallel during 2 periods of 14 d to detect tidal and seasonal variations. Our results showed a weak relationship between mud fraction and MPB biomass in March, and this relationship fully disappeared in July. Tidal exposure was the most important parameter in explaining the summer temporal dynamics of MPB. This study reveals the general importance of bed elevation and tidal exposure in muddy habitats and that silt content was a prime governing physical factor in winter. Biostabilisation processes seemed to behave only as secondary factors that could only amplify the initial silt accumulation in summer rather than primary factors explaining spatial or long-term trends of sediment changes.

Investigations on growth ecology and reproduction of Sargassum sp. and Gracilaria on intertidal region in Bandar Lenge

Investigations on growth and quantity of phycocolloids of Sargassum sp. and Gracilaria corticata was done on field and laboratorial works over one year from January 2003 to May 2004. Sargassum thalli began growth from January. The highest biomass value recorded 1611.04 gm^-2 was obtained in November. The receptacles appeared on November and released eggs. The senescence of Sargassum thalli was in December and the new thallus began to grow from January, The highest relative growth rate (6.74 percent) was in February. The relative growth rate showed significant correlation (p<0,05) with temperature. The highest value of alginate was in November (10.02 percent). Alginat content showed significant correlations (p<0.05) with Sargassum biomass. There was no significant effect of environmental factors on alginate content. The highest biomass of Graciiaria was in Match (49.88 gm^-2). Maximum relative growth rate of Gracilara (2 percent) was in December. Relative growth rate of Gracilaria (2.8 percent) was in December. Relative growth rate of Gracilaria showed significant correlations (p<0.05) with temperature. There was significant effect of ammonium (p<0.05) on growth factors of Gracilaria, maximum agar content was in August {10.005 percent). The yield of agar showed significant correlation (p<0.05) with Gracilaria biomass and ammonium in field and laboratory.

Rising temperatures increased recruitment of brown tiger prawn (Penaeus esculentus) in Moreton Bay (Australia)

Abiotic factors are fundamental drivers of the dynamics of wild marine fish populations. Identifying and quantifying their influence on species targeted by the fishing industry is difficult and very important for managing fisheries in a changing climate. Using multiple regression, we investigated the influence of both temperature and rainfall on the variability of recruitment of a tropical species, the brown tiger prawn (Penaeus esculentus), in Moreton Bay which is located near the southern limit of its distribution on the east coast of Australia. A step-wise selection between environmental variables identified that variations in recruitment from 1990 to 2014 were best explained by a combination of temperature and spawning stock biomass. Temperature explains 35% of recruitment variability and spawning stock biomass 33%. This analysis suggests that increasing temperatures have increased recruitment of brown tiger prawn in Moreton Bay.

Ecologie de la baie de Nhatrang: étude des peuplements animaux du faciès rocheux intertidal

From the analysis of typical animal populations, the author tries to draw an outline of a general bionomic system and to describe the effects of predominant ecological factors (wave action, insolation, salinity and contents of sea water) on the characteristic species (Tectarius nodulosus, Tectarius novaezelandiae, Chthamalus stellatus, Tetraclita porcsa, Ostrea forskali, Balanus tintinna bulum and Madreporaria). He also outlined a rapid sketch of seasonal variations of the biota.

Ecologie de la Baie de Nhatrang. II: Principales espèces végétales et animales du facies rocheux intertidal: rapport préliminaire

This primary report includes 168 common, vegetal and animal species collected on the intertidal rocky shore of the Nhatrang Bay, during the study of the ecology of this area.