On a quasilinear elliptic differential equation in unbounded domains

Existence and multiplicity results for a variational quasilinear elliptic equation on unbounded domains are proved; the solutions are obtained as critical points of a nonsmooth functional. We consider the case where the functional is coercive or has a saddle-point geometry

Characterization of airborne viromes in cheese production plants

Aims To characterize airborne virus like particles isolated from two cheese production plants in order to reveal their complexity in terms of viral communities and microbial genes potentially mobilized by viruses. Methods and results Airborne virus like particles have been isolated from Grana Padano and Gorgonzola PDO cheese production plants and ripening cellars. A shotgun metagenomics analysis of the isolated viromes highlighted a high complexity of the viral communities both in terms of viral taxonomy and phage\u2010host associations. Bacterial reads in each of the viromes were confirmed to be abundant and their taxonomy appeared to be associated to the environmental parameters and the technological processes that characterize the sampling area. Antibiotic resistance genes have been identified in each virome thus confirming that phages could be involved in the mobilization of antimicrobial resistances among bacterial populations. Interestingly human viruses were also identified even if the contamination source was not revealed. Conclusions The environmental conditions, which are imposed by the technology of the dairy process, seams to shape the viral populations as a consequence of the adaptation of microbial taxa to those environments. The identification of sequences belonging to Legionella pneumophila and to the human papillomavirus, raised some considerations about the safety of cheese ripening cellars. Significance and impact of the study In conclusion, the analysis of the dairy airborne viromes, has revealed a high complexity of the viral communities even if the environments where the samples were collected were confined environments. Metagenomics of airborne viral population could be a promising monitoring tool for the biological characterization of dairy environments

Development of a milk-based medium for the selection of urease-defective mutants of Streptococcus thermophilus

Streptococcus thermophilus strains are used in fermented dairy products for their capacity to metabolize lactose into lactic acid. The rate of lactic acid production in milk is of major economic importance, as rapid acidification prevents growth of undesirable microorganisms. It is also of paramount significance for aroma, texture and flavor of the end product. Besides achieving customer satisfaction, improvement of production rate and operational costs incite industrials into selecting fast acidifying strains. Another important trait of S. thermophilus influencing acidification is the urease, which catabolizes urea into ammonia and has a detrimental effect on acidification. Unfortunately, most of the S. thermophilus strains possess the urease, and the urease-negative ones are necessary for industrial applications. Urease activity is a widely distributed activity in S. thermophilus species, and urease-negative strains are rare. The later are however interesting from an industrial point of view, as they may give faster acidification in dairy applications, because lactic acid is not buffered by urea-derived ammonia. Nowadays, the efforts to improve the characteristics of strains for industrial applications are based on natural strategies such as random mutagenesis. This implies the need of a screening method that is efficient in terms of time and success. In this context, the aim of this study was the development of a new medium that allows selection of urease-defective mutants based on S. thermophilus colony morphology. Discrimination capacity of the new medium was verified using previously characterized urease-negative recombinant strains. The new milk-based medium, applied to industrial S. thermophilus strains subjected to UV mutagenesis, allowed the selection of 3 mutants, partially or completely defective in urease activity. Genetic characterization of urease-defective mutants highlighted the presence of nonsense or missense mutations in the ureA, ureC and ureG genes, thus supporting their phenotype. Evaluation of milk acidification revealed increased performance for one out of three urease-defective mutants compared to wild-type strains

Mono-dimensional blue native-PAGE and bi-dimensional blue native/urea-PAGE or /SDS-PAGE combined with nLC-ESI-LIT-MS/MS unveil membrane protein heteromeric and homomeric complexes in streptococcus thermophilus

Protein interactions are essential elements for the biological machineries underlying biochemical and physiological mechanisms indispensable for microorganism life. By using mono-dimensional blue native polyacrylamide gel electrophoresis (1D-BN-PAGE), two-dimensional blue native/urea-PAGE (2D-BN/urea-PAGE) and two-dimensional blue native/SDS-PAGE (2D-BN/SDS-PAGE), membrane protein complexes of Streptococcus thermophilus were resolved and visualized. Protein complex and oligomer constituents were then identified by nLC-ESI-LIT-MS/MS. In total, 65 heteromeric and 30 homomeric complexes were observed, which were then associated with 110 non-redundant bacterial proteins. Protein machineries involved in polysaccharide biosynthesis, molecular uptake, energy metabolism, cell division, protein secretion, folding and chaperone activities were highly represented in electrophoretic profiles; a number of homomeric moonlighting proteins were also identified. Information on hypothetical proteins was also derived. Parallel genome sequencing unveiled that the genes coding for the enzymes involved in exopolysaccharide biosynthesis derive from two separate clusters, generally showing high variability between bacterial strains, which contribute to a unique, synchronized and active synthetic module. The approach reported here paves the way for a further functional characterization of these protein complexes and will facilitate future studies on their assembly and composition during various growth conditions and in different mutant backgrounds, with important consequences for biotechnological applications of this bacterium in dairy productions. Biological significance Combined proteomic procedures have been applied to the characterization of heteromultimeric and homomeric protein complexes from the membrane fraction of S. thermophilus. Protein machineries involved in polysaccharide biosynthesis, molecular uptake, energy metabolism, cell division, protein secretion, folding and chaperone activities were identified; information on hypothetical and moonlighting proteins were also derived. This study is original in the lactic bacteria context and maybe considered as preliminary to a deeper functional characterization of the corresponding protein complexes. Due to the large use of S. thermophilus as a starter for dairy productions, the data reported here may facilitate future investigations on protein complex assembly and composition under different experimental conditions or for bacterial strains having specific biotechnological applications

Coexistence of diploid and triploid hybrid water frogs: population differences persist in the apparent absence of differential survival

Background: The role of differential selection in determining the geographic distribution of genotypes in hybrid systems has long been discussed, but not settled. The present study aims to asses the importance of selection in structuring all-hybrid Pelophylax esculentus populations. These populations, in which the parental species (P. lessonae with genotype LL and P. ridibundus with genotype RR) are absent, have pond-specific proportions of diploid (LR) and triploid (LLR and LRR) genotypes. Results: With data from 12 Swedish ponds, we first show that in spite of significant changes in genotype proportions over time, the most extreme ponds retained their differences over a six year study period. The uneven distribution of genotypes among ponds could be a consequence of differential selection varying among ponds (selection hypothesis), or, alternatively, of different gamete production patterns among ponds (gamete pattern hypothesis). The selection hypothesis was tested in adults by a six year mark-recapture study in all 12 ponds. As the relative survival and proportion of LLR, LR and LRR did not correlate within ponds, this study provided no evidence for the selection hypothesis in adults. Then, both hypotheses were tested simultaneously in juvenile stages (eggs, tadpoles, metamorphs and one year old froglets) in three of the ponds. A gradual approach to adult genotype proportions through successive stages would support the selection hypotheses, whereas the presence of adult genotype proportions already at the egg stage would support the gamete pattern hypothesis. The result was a weak preference for the gamete pattern hypothesis. Conclusions: These results thus suggest that selection is of little importance for shaping genotype distributions of all-hybrid populations of P. esculentus, but further studies are needed for confirmation. Moreover, the study provided valuable data on genotype-specific body lengths, adult survival and sex ratios

Prevalence of Vertebral Fractures in Osteoporotic HIP Fractured Patients: The Focus Study

Osteoporosis is a multifactorial systemic skeletal disease, characterized by low bone mass and microarchitectural modifications of bone tissue, with a consequent increase in fragility fractures. Vertebral fractures are the most prevalent osteoporotic fractures and osteoporotic hip fractures are the most serious complication of osteoporosis resulting in increased mortality and high socio-economic cost. The coexistence of these two pathological conditions in elderly patients has been previously described, leading to even worse functional outcomes than each one alone. To determine the prevalence of vertebral fractures in osteoporotic hip fractured women and to evaluate the relationship between prevalence of vertebral fractures and pre-existing factors such us autonomy in daily life activity, quality of walking, numbers of falls, cognitive aspects and comorbidities. 946 osteoporotic hip fractured women aged more than 60 years and with an X-ray evaluation of spine were consecutively enrolled in 25 Orthopaedic, Physical Medicine and geriatric centers in Italy. After spine X-ray morphometry patients were divided in two groups: previous vertebral fracture (F) and no previous fracture (NF). Moreover anamnestic, demographical and outcome related data (ADL, IADL, CIRS, SPMSQ, FAC and RANKIN scale) were collected. Prevalent vertebral fractures were present in 502 (54%) patients. 119 (13.7%) patients had at least one severe fracture. The F compared to NF group showed statistically significant worse scores regarding the pre hip fracture values of RANKIN, CIRS, SPMSQ, IADL and the overall number of falls (p<0.001). Moreover the F group showed statistically significant lower values of serif 25(OH)D than NF group (p<.0.001). Previous Vertebral fractures in hip fractured patients are a common issue and negatively influence several functional and cognitive outcome measures in these patients

The role of aerodynamic forces in a mathematical model for suspension bridges

In a fish-bone model for suspension bridges studied by us in a previous paper we introduce linear aerodynamic forces. We numerically analyze the role of these forces and we theoretically show that they do not influence the onset of torsional oscillations. This suggests a new explanation for the origin of instability in suspension bridges: it is a combined interaction between structural nonlinearity and aerodynamics and it follows a precise pattern. This gives an answer to a long-standing question about the origin of torsional instability in suspension bridges

Acompanhamento da eficiência de atrativos alimentares para o monitoramento de Anastrepha fraterculus (Diptera: Tephritidae) na cultura da macieira.

O objetivo do trabalho foi acompanhar a eficiência de atrativos alimentares para o monitoramento da espécie em pomar comercial em São Joaquim, SC no ano agrícola 2013/2014

Flutuação populacional de Grapholita molesta (Busck) com armadilhas de feromôniosexual na cultura do pessegueiro em Bento Gonçalves, RS, Brasil.

A flutuação populacional de machos deGrapholita molesta (Busck, 1916) (Lepidoptera: Tortricidae)foi avaliada em dois pomares comerciais de pessegueiro dacultivar Chiripá em Bento Gonçalves, RS, entre julho de 2000a junho de 2002. Os insetos foram capturados por meio dearmadilhas Delta (duas por pomar) iscadas com a formulaçãocomercial do feromônio sexual sintético (E-8-dodecenil-acetato + Z-8-dodecenil-acetato + Z-8-dodecenol) e avaliadossemanalmente. Foram observados quatro picos populacionaisdurante o período de produção do pessegueiro: quartasemana de agosto, primeira de novembro e dezembro, esegunda de janeiro. A temperatura média dos sete diasanteriores à cada avaliação foi correlacionada positivamentecom o número de adultos da G. molesta capturados nasarmadilhas. As informações deste trabalho podem serutilizadas para orientar os produtores de pessegueiro, visandoa direcionar as táticas de controle para os períodos em que apopulação do inseto for mais elevada nos pomarescomerciais.Palavras-chave:Mariposa oriental, levantamentopopulacional, pêssego. ABSTRACT Seasonal fluctuation of male Grapholita molesta(Busck, 1916) (Lepidoptera: Tortricidae) was evaluated intwo commercial peach orchards cv Chiripá in BentoGonçalves, RS, from June of 2000 to July of 2002. The insectswere evaluated weekly using Delta traps (two/orchard) baitedwith commercial synthetic sex pheromone (E-8-dodecenil-acetato + Z-8-dodecenil-acetato + Z-8-dodecenol). Fourpeaks were observed during peach production period: lastweek of August, first of November and December and secondof January. Medium temperature seven days before evaluationwas positively correlated with catches of male G. molesta inthe traps. Information about seasonal fluctuation can beused for growers as a tool to guide insecticide treatments forpest control in peach orchards.Key words:oriental fruit moth, seasonal fluctuation, peach