Technological characterization of vaginal probiotic lactobacilli: resistance to osmotic stress and strains compatibility

Aims: The aim was to evaluate the osmotic stress resistance of vaginal beneficial probiotic strains, their growth kinetics and parameters when growing in salt-added culture media, and their compatibility to go further in the design of a probiotic formula for reconstitution of vaginal microbiome in women. Methods and Results: The resistance to osmotic stress of the lactobacilli was evaluated by determining their growth in MRS (as control) added with NaCl (2–8%). The most resistant strains were Lactobacillus gasseri CRL1509, L. rhamnosus CRL1332 and L. reuteri CRL1327 selected by statistical approaches and growth parameters. Electron microscopy was applied to determine changes. They maintain probiotic properties and viability. Some strains showed incompatibility, then they cannot be included in multistrain formulas. Conclusions: The resistance to different salt concentrations in vaginal lactobacilli is strain-specific, because the behaviour is different in strains identified into the same species. The resistance is not related to the metabolic groups. Significance and Impact of the Study: The resistance and survival to extreme osmotic resistance is one of the specific requirements of beneficial bacteria after the technological processes for their inclusion in probiotic formulas, in a way to express their beneficial characteristics and exert the effect on the host.Fil: Silva, Jessica Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Marchesi, Antonella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Birgitt, Wiese. Hannover Medical School; AlemaniaFil: Nader, Maria Elena Fatima. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin

Elder Isolation in Immigrant Communities

This paper examined loneliness, as a measurement of perceived social isolation, in older immigrant adults. Previous research shows that older adults are more likely to experience social isolation and loneliness. Both of which have a direct correlation with their overall health (Wilson & Molton, 2010, Cacioppo et al., 2002) and mortality rates (Holt-Lunstad et al, 2015). Another international study found that immigrants in particular are at a higher risk for experiencing loneliness (Government of Canada, 2018). In this study, 35 immigrants and non-immigrants participants answered a survey which included 20 questions from the UCLA Loneliness Scale Version 3 (Russel, 1996). Participants were residents of the San Francisco Bay area and ranged in age from under 45 years to over 76 years. Results were non-statistically significant. While the results did not support the study hypotheses, they suggested that older immigrant adults who migrated over the age of 18 feel more lonely than other adults

Graphs with few spanning substructures

In this thesis, we investigate a number of problems related to spanning substructures of graphs. The first few chapters consider extremal problems related to the number of forest-like structures of a graph. We prove that one can find a threshold graph which contains the minimum number of spanning pseudoforests, as well as rooted spanning forests, amongst all graphs on n vertices and e edges. This has left the open question of exactly which threshold graphs have the minimum number of these spanning substructures. We make progress towards this question in particular cases of spanning pseudoforests. The final chapter takes on a different flavor---we determine the complexity of a problem related to Hamilton cycles in hypergraphs. Dirac\u27s theorem states that graphs with minimum degree at least half the size of the vertex set are guaranteed to have a Hamilton cycle. In 1993, Karpinksi, Dahlhaus, and Hajnal proved that for any c\u3c1/2, the problem of determining whether a graph with minimum degree at least cn has a Hamilton cycle is NP-complete. The analogous problem in hypergraphs, for both a Dirac-type condition and complexity, are just as interesting. We prove that for classes of hypergraphs with certain minimum vertex degree conditions, the problem of determining whether or not they contain an l-Hamilton cycle is NP-complete. Advisor: Professor Jamie Radcliff

HIV/AIDS in the Latino Community of San Francisco: Past and Present

There are approximately 122,000 people of Latino origin in San Francisco, which account for 15% of the total population (Census, 2010). Historically, Latinos have and still face several barriers to access healthcare and improvements in health (Aguirre-Molina, Molina & Zambrana, 2001). When the world was exposed to the spread of a new and unknown virus, the broader population suffered from the epidemic. The Latino community in San Francisco was and still is one of the hardest hit by the virus

The combinatorics of interval-vector polytopes

An \emph{interval vector} is a $(0,1)$-vector in $\mathbb{R}^n$ for which all the 1's appear consecutively, and an \emph{interval-vector polytope} is the convex hull of a set of interval vectors in $\mathbb{R}^n$. We study three particular classes of interval vector polytopes which exhibit interesting geometric-combinatorial structures; e.g., one class has volumes equal to the Catalan numbers, whereas another class has face numbers given by the Pascal 3-triangle.Comment: 10 pages, 3 figure

Sexual dimorphism in bite performance drives morphological variation in chameleons

Phenotypic performance in different environments is central to understanding the evolutionary and ecological processes that drive adaptive divergence and, ultimately, speciation. Because habitat structure can affect an animal's foraging behaviour, anti-predator defences, and communication behaviour, it can influence both natural and sexual selection pressures. These selective pressures, in turn, act upon morphological traits to maximize an animal's performance. For performance traits involved in both social and ecological activities, such as bite force, natural and sexual selection often interact in complex ways, providing an opportunity to understand the adaptive significance of morphological variation with respect to habitat. Dwarf chameleons within the Bradypodion melanocephalum-Bradypodion thamnobates species complex have multiple phenotypic forms, each with a specific head morphology that could reflect its use of either open-or closed-canopy habitats. To determine whether these morphological differences represent adaptations to their habitats, we tested for differences in both absolute and relative bite performance. Only absolute differences were found between forms, with the closed-canopy forms biting harder than their open-canopy counterparts. In contrast, sexual dimorphism was found for both absolute and relative bite force, but the relative differences were limited to the closed-canopy forms. These results indicate that both natural and sexual selection are acting within both habitat types, but to varying degrees. Sexual selection seems to be the predominant force within the closed-canopy habitats, which are more protected from aerial predators, enabling chameleons to invest more in ornamentation for communication. In contrast, natural selection is likely to be the predominant force in the open-canopy habitats, inhibiting the development of conspicuous secondary sexual characteristics and, ultimately, enforcing their overall diminutive body size and constraining performance