Kinetics of tidal resuspension of microbiota: Testing the effects of sediment cohesiveness and bioturbation using flume experiments

Resuspension of the top few sediment layers of tidal mud flats is known to enhance planktonic biomass of microbiota (benthic diatoms and bacteria). This process is mainly controlled by tidal shear stress and cohesiveness of mud, and is also influenced by bioturbation activities. Laboratory experiments in a race track flume were performed to test the interactive effects of these factors on both the critical entrainment and resuspension kinetics of microbiota from silt-clay sediments from the Marennes-Oleron Bay, France. The marine snail Hydrobia ulvae was used to mimic surface bioturbation activities. As expected, the kinetics of microbial resuspension versus shear stress were largely controlled by the cohesiveness of silt-clay sediments. However, our results indicate that the effect of surface tracking by H. ulvae on microbial resuspension was clearly dependent on the interaction between sediment cohesiveness and shear velocity. Evidence was also found that microphytobenthos and bacteria are not simultaneously resuspended from silt-clay bioturbated sediments. This supports the theory that diatoms within the easily eroded mucus matrix behave actively and bacteria adhering to fine silt particles eroded at higher critical shear velocities behave passively.

Minas-type fresh cheese developed from buffalo milk with addition of L. acidophilus

Effective incorporation of a probiotic into foods requires the culture to remain viable all along processing and storage, without adverse alterations to sensory characteristics. The objective of this work was developing Minas-type fresh cheese with probiotic properties from buffalo milk. Four batches of Minas-type fresh cheese were prepared using buffalo milk: batch T1 in which neither culture nor lactic acid added; batch T3 in which only lactic acid added; batches T2 and T4 , both added of Lactobacillus acidophilus LAC 4, but T4 was also acidified. Resulting cheeses were evaluated for probiotic culture stability, texture profile, sensory acceptance, and changes in pH. The T4 probiotic cheese presented hardness, gumminess, and chewiness significantly lower than the other treatments. However, values for springiness and cohesiveness did not differ between all cheeses, and no sensory differences (p > 0.05) were found between treatments for texture, taste, and overall acceptance. The addition of probiotic to the acidified cheese (T4) yielded best aroma. The populations of L. acidophilus were greater than 10(6) CFU g-1 after 28 days of storage all products. Minas-type fresh cheese from buffalo milk is a suitable food for the delivery of L. acidophilus, since the culture remained viable during the shelf life of the products and did not negative affect analysed parameters.

Thermal and mechanical characteristics of polyurethane/curaua fiber composites

Polyurethane composites reinforced with curaua fiber at 5, 10 and 20% mass/mass proportions were prepared by using the conventional melt-mixing method. The influence of curaua fibers on the thermal behavior and polymer cohesiveness in polyurethane matrix was evaluated by dynamic mechanical thermal analysis (DMTA) and by differential scanning calorimetry (DSC). This specific interaction between the fibers and the hard segment domain was influenced by the behavior of the storage modulus E` and the loss modulus EaEuro(3) curves. The polyurethane PU80 is much stiffer and resistant than the other composites at low temperatures up to 70A degrees C. All samples were thermoplastic and presented a rubbery plateau over a wide temperature range above the glass transition temperature and a thermoplastic flow around 170A degrees C.

Social identity and self-categorization processes in organizational contexts

Although aspects of social identity theory are familiar to organizational psychologists, its elaboration, through self-categorization theory, of how social categorization and prototype-based depersonalization actually produce social identity effects is less well known. We describe these processes, relate self-categorization theory to social identity theory, describe new theoretical developments in detail, and show how these developments can address a: range of organizational phenomena. We discuss cohesion and deviance, leadership, subgroup and sociodemographic structure, and mergers and acquisitions.

A multidimensional approach to the group cohesion-group performance relationship

This study (a) examined the multidimensionality of both group cohesion and group performance, (b) investigated the relationship between group-level task and social cohesion and group effectiveness, and (c) examined the longitudinal changes in cohesion and performance and the direction of effect between cohesion and performance. First, the authors hypothesized that both task and social cohesion would predict positively all dimensions of group performance. Second, that a stronger relationship would be observed between task cohesion and task effectiveness and between social cohesion and system viability. Third, that all dimensions of cohesion and performance would increase over time. Finally, that cohesion would be both the antecedent and the consequence of performance but that the performance-cohesion relationship would be stronger than the cohesion-performance relationship. Results supported the hypothesized one-to-one relationship between specific dimensions of group cohesion and group performance. Task cohesion was the sole predictor of self-rated performance at both Time 1 and Time 2, whereas social cohesion was the only predictor of system viability at Time 1 and the stronger predictor at Time 2. Social cohesion at Time 2 predicted performance on group task. However, no longitudinal changes were found in cohesion or performance. Finally, group cohesion was found to be the antecedent, but not the consequence, of group performance.

Novel ready-to-eat mango product using gellan gum as gelling agent: physico-chemical, microbial and sensory characteristics

Este trabalho foi efectuado com o apoio da Universidade de Lisboa, Instituto Superior de Agronomia com o Centro de Engenharia dos Biossistemas (CEER

Manipulating keratinocyte stem cell proliferation and differentiation using RNA interference

ABSTRACT : The epidermis, the outermost compartment of the skin, is a stratified and squamous epithelium that constantly self-renews. Keratinocytes, which represent the main epidermal population, are responsible for its cohesion and barrier function. Epidermal renewal necessitates a fine equilibrium between keratinocyte proliferation and differentiation. The keratinocyte stem cell, located in the basal cell layer, is responsible for epidermal homeostasis and regeneration during the wound healing process. The transcription factor p63 structurally belongs to the p53 superfamily. It is expressed in the basal and supra-basal cell layers of stratified epithelia and is thought to be important for the renewal or the differentiation of keratinocyte stem cells (Yang et al., 1999; Mills et al., 1999). In order to better understand its function, we established an in vitro model of p63 deficient human keratinocyte stem cells using a shp63 mediated RNA interference. Knockdown of endogenous p63 induces downregulation of cell-adhesion genes as previously described (Carroll et al., 2006). Interestingly, the replating of attached p63-knockdown keratinocytes on a feeder layer results in a loss of attachment and proliferation. They are no longer clonogenic. However, if the same population are replated in a fibrin matrix, extended fibrinolysis is reported, a common process in wound healing, suggesting that p63 regulates the fibrinolytic pathway. This result was confirmed by Q-PCR and shows that the urokinase pathway, which mediates fibrinolysis, is upregulated. Altogether, these findings suggest a mechanism in which the fine tuning of p63 expression promotes attachment or release of the keratinocyte stem cell from the basement membrane by inducing genes of adhesion and/or of fibrinolysis. This mechanism may be important for epidermal self-renewal, differentiation as well as wound healing. Its misregulation may be partly responsible for the p63 knockout phenotype. The downregulation of p63 also induces a decrease in LEKTI expression. LEKTI (lymphoepithelial Kazal-type serine protease inhibitor) is a serine protease inhibitor encoded by the Spink5 gene. It is expressed and secreted in the uppermost differentiated layers of stratified epithelia and plays a role in the desquamation process. When this gene is disrupted, humans develop the Netherton syndrome (Chavanas et al., 2000b). It is a dermatosis characterized by hair dysplasias, ichtyosiform erythroderma and impairment in epidermal barrier function promoting inflammation similarly as in psoriasis with inflammatory infiltrate in excess. TNFα (tumor necrosis factor alpha) and EDA1 (ectodysplasin A1) are two transmembraneprecursors that belong to the TNF superfamily, which is involved in immune and inflammation regulation (Smahi et al., 2002). We suggest that the secreted serine protease inhibitor LEKTI plays a role in the regulation of TNFα and EDA1 precursor cleavage and absence of LEKTI induces excess of inflammation. To investigate this hypothesis, we induced downregulation of Spink5 expression in rat keratinocyte stem cells by using a shSpink5 mediated RNA interference approach. Interestingly, expression of TNFα and EDA1 is modified after knockdown of Spink5 by Q-PCR. Moreover, downregulation of Spink5 induces loss of cohesiveness between keratinocytes and colonies adopt a scattered phenotype. Altogether, these preliminary data suggest that downregulation of LEKTI may play a role in the inflammatory response in Netherton syndrome patients, by regulating TNFα expression.

Aportacions per a una bibliografia de l'exili republicà català, valencià i balear als Estats Units d'Amèrica

This article attempts to gather together the work published in the United States and Puerto Rico by Spanish Civil War exiles of Catalan, Valencia and Balearic origin. Included are books, serials, sheet music, sound recordings and domestic movie videos, which have appeared in US territory from 1936 through 2004. The objective of the bibliography is to provide both an overview and a starting point for recovering the intellectual effort carried out by these exiles because this first inventory must still be completed with the addition of journal articles, contributions to monographs, and conference proceedings. There have also been exiles for whom books, music or videos have not been found, but for whom a certain level of intellectual activity is known or suspected. Such potential work would include articles and other contributions to journals in the US or cultural and membership activities of Catalan communities in that country. Without being able to offer definitive conclusions, it appears that exile in North America was a solitary experience, and never as a cohesive group or with the ties of mutual interests as was the case in Mexico or even in France. There were neither readers nor publishers to facilitate publication and to serve for creating group cohesiveness.

Tumor cell budding and laminin-5 expression in colorectal carcinoma can be modulated by the tissue micro-environment.

Expression of laminin-5 alpha3, beta3 and gamma2 protein subunits was investigated in colorectal adenocarcinomas using immunostaining and confocal microscopy. The laminin-5 heterotrimer was found in basement membranes and as extracellular deposits in tumor stroma. In contrast to the alpha3 subunit, which was under-expressed, the gamma2 and beta3 subunits were detected in the cytoplasm of carcinoma cells dissociating (budding) from neoplastic tubules, suggestive of focal alterations in laminin-5 assembly and secretion. Laminin-5 gamma2 or beta3 subunit-reactive budding carcinoma cells expressed cytokeratins but not vimentin; they did not proliferate and were not apoptotic. Furthermore, expression of laminin-5 gamma2 and beta3 subunits in budding cells was associated with focal under-expression of the E-cadherin-beta-catenin complex. Results from xenograft experiments showed that budding activity in colorectal adenocarcinomas could be suppressed when these tumors grew at ectopic s.c. sites in nude mice. In vitro, cultured colon carcinoma cells, but not adenoma-derived tumor cells, shared the laminin-5 phenotype expressed by carcinoma cells in vivo. Using colon carcinoma cell lines implanted orthotopically and invading the cecum of nude mice, the laminin-5-associated budding was restored, indicating that this phenotype is not only determined by tumor cell properties but also dependent on the tissue micro-environment. Our results indicate that both laminin-5 alpha3 subunit expression and cell-cell cohesiveness are altered in budding carcinoma cells, which we consider to be actively invading. We propose that the local tissue micro-environment contributes to these events.

Iowa Legal Assistance Program Best Practices, 2009

Legal problems faced by older Iowans are often more critical than those problems faced by any other segment of our population. Older Iowans in poverty are less likely to seek the assistance of an attorney. Often, it is either because they do not have cash resources to pay for services or they do not realize that they have a “legal problem.” The Older Americans Act of 1965 (hereafter, OAA) as amended, which primarily funds the Legal Assistance Program, requires that states have the capacity to improve the quality and quantity of legal programs for older individuals. These Legal Assistance Program Best Practices are meant to provide guidance to providers in the area of priority casework, coordination and collaboration to ensure cohesiveness and uniformity throughout the state’s legal assistance programs. Additionally, Congress mandates that states improve the quality of their Title III-B legal programs. One proven way to ensure a quality program is to have in place best practices to define expectations for not only the legal assistance program provider, but for the state unit on aging (the Iowa Department on Aging) and the area agencies on aging as well. These legal assistance program best practices may be amended from time to time to reflect the change in the legal needs of older Iowans as well as the mandates under the OAA, Iowa Department on Aging (hereafter, department) policy and other governing state and federal laws and regulations.

Assessment of high hydrostatic pressure and starter culture on the quality properties of low-acid fermented sausages

The addition of starter culture and high pressure processing after ripening improved the microbial quality of low-acid fermented sausages (fuet and chorizo). The use of Lactobacillus sakei CTC6626 and Staphylococcus xylosus CTC6013 as starter culture significantly reduced Enterobacteriaceae and Enterococcus levels in the finished sausages. Moreover, the addition of starter culture produced sausages of similar quality to traditional low-acid fermented sausages. Slightly lower pH values and higher cohesiveness were obtained for both fuet and chorizo with starter culture. Sensory analysis showed no differences between lots of chorizo whereas starter fuet was more acid and gummy. High pressure induced an additional reduction of Enterobacteriaceae in non-starter sausages. An increase of textural properties was observed after pressurization. No other differences were observed between non-treated and pressurized sausages.

La influència de les dinàmiques de grup en la millora de la cohesió de grup i l’estabilitat emocional dels infants

En aquest estudi qualitatiu s’investiga la influència de les dinàmiques de grup en la millora de la cohesió de grup i l’estabilitat emocional dels infants. La mostra està constituïda per 24 infants, d’edats compreses entre els 5 i 6 anys, i per una mestra de 58 anys. Es realitza una intervenció educativa, basada en quatre dinàmiques de grup diferents, per tal d’avaluar la seva incidència en relació a la cohesió de grup i l’estabilitat emocional dels infants. Els instruments utilitzats són de naturalesa qualitativa, concretament, l’entrevista i l’observació, que s’apliquen pre i post intervenció per tal d’identificar possibles canvis. En els resultats, no es poden observar grans canvis a nivell de cohesió de grup ni d’estabilitat emocional dels infants, però sí, una actitud positiva i de motivació en relació a l’aplicació de dinàmiques de grup. La curta durada de la intervenció educativa ha estat la principal limitació d’aquesta investigació, fet pel qual no s’han pogut extreure uns resultats significatius. És per això que a les conclusions es mostren un seguit d’aspectes a tenir en compte en futurs estudis.

Interferon gamma is a key cytokine in lung phase immunity to schistosomes but what is its precise role?

Vaccination of mice with radiation-attenuated cercariae of Schistosoma mansoni induces a high level of protection against challenge with normal larvae. The immune effector mechanism, which operates in the lungs, is a cell-mediated delayed-type hypersensitivity response and involves the formation of a tight focus of mononuclear cells around embolised larvae. CD4+ T cells with Th1 characteristics are a major component of the infiltrate. They secrete abundant interferon gamma (IFNg) upon antigen stimulation in vitro, whilst in vivo neutralisation of the cytokine results in 90% abrogation of immunity. IFNg can induce a large number of genes and an attempt has been made to identify the ones which are essential components of the effector mechanism. Inducible nitric oxide synthase (iNOS) is such a candidate and nitric oxide (NO) is produced by cultures of airway leucocytes from the lungs of vaccinated mice post-challenge. However, the continued resistance of mice with a disrupted iNOS gene indicates that NO has only a minor role in the protective response. Mice with a disrupted IFNg receptor gene have been used to dissect the role of the cytokine. After vaccination and challenge, CD4+ T cells from the pulmonary interstitium have reduced levels of ICAM-1 and LFA-1 expression, compared to wild-type animals, which coincides with a reduced cohesiveness of foci. However, immunity is not significantly impaired in mice with a disrupted ICAM-1 gene, and focus formation is normal. Similarly, a role has not been found for CD2/CD48 interactions in cell aggregation. Possible IFNg-inducible molecules yet to be fully investigated include other ligand-receptor pairs, chemokines, and tumour necrosis factor a.

Evaluation of thermotolerant capacity of lactic acid bacteria isolated from commercial sausages and the effects of their addition on the quality of cooked sausages

The thermotolerant capacity of several lactic acid bacteria strains isolated from cooked commercial sausages was determined. Four strains were positively identified as Lactobacillus plantarum, Lactobacillus curvatus, Pediococcus pentosaceus and Pediococcus acidilacti, after surviving thermal treatment (70 °C during 60 minutes). Thermotolerant strains were inoculated in sausage batters before cooking in order to determine their effect on color, texture, acceptance and inhibition of Enterobacteria during 12 days at 8 °C. No significant effect of the inoculated strains was detected on color parameters. Textural profile parameters, cohesiveness and resilience, were not affected by the inoculation of thermotolerant lactic acid bacteria, but L. curvatus sausages resulted softer than the rest of the treatments. Samples inoculated with L. curvatus also obtained the lowest scores for the sensory attributes evaluated, with the remaining treatments causing no unfavorable effects on sausage acceptance. There was a reduction in enterobacterial counts after 12 days of cold storage in inoculated samples. The performance of inoculated lactic acid bacteria strains can be explained in a similar way as that of starter cultures in dry-fermented sausages, where the growth in nests impairs other pathogenic microorganisms present in the rest of the sausage, since environmental conditions and the early inoculation of these thermotolerant strains favor them to become the dominant flora.

Okara, a soymilk industry by-product, as a non-meat protein source in reduced fat beef burgers

Okara is a by-product generated during the manufacture of soymilk and tofu. Wet okara was added to beef burgers at 0%, 20%, and 25%. The effects of okara on certain physicochemical, textural, and sensory properties of reduced fat beef burgers were investigated. The beef burgers formulated with okara (104.0-106.0 kcal/100 g) had 60% less calories than commercial beef burgers (268.8 kcal/100 g). The texture profile analysis showed that the addition of wet okara led to a significant increase in hardness (p < 0.05) and a concomitant reduction in the values of chewiness, springiness, and cohesiveness. Lower sensory scores (p < 0.05) of flavour were observed in the beef burgers containing 25% wet okara. However, the sensory evaluation results showed that juiciness, appearance, tenderness, and overall acceptability of beef burgers formulated with okara did not differ statistically from that of the control (0% okara). Wet okara (20%) can be used as a non-meat protein source in the production of reduced-fat beef burgers without changing their sensory quality.