896 research outputs found
A food chain ecoepidemic model: infection at the bottom trophic level
In this paper we consider a three level food web subject to a disease
affecting the bottom prey. The resulting dynamics is much richer with respect
to the purely demographic model, in that it contains more transcritical
bifurcations, gluing together the various equilibria, as well as persistent
limit cycles, which are shown to be absent in the classical case. Finally,
bistability is discovered among some equilibria, leading to situations in which
the computation of their basins of attraction is relevant for the system
outcome in terms of its biological implications
Urotensin-II Receptor: A Double Identity Receptor Involved in Vasoconstriction and in the Development of Digestive Tract Cancers and other Tumors
Urotensin II and Urotensin-II receptors are important molecular factors that regulate vasoconstriction and all the diseases that are linked to abnormalities in blood pressure regulation (i.e.: hypertension, kidney diseases, cirrhosis etc.). Recently, Urotensin II and its receptor have also been involved in metabolic syndrome, diabetes and schizophrenia. Recent strong findings suggest that Urotensin II and its receptor are involved in the onset and development of different epithelial cancers. Indeed, it was reported that cell growth, motility and invasion in human breast, bladder, prostate, colorectal and glioblastoma cancer cells were regulated by Urotensin II and Urotensin-II receptor axis. This axis also regulated focal adhesion kinase and small Guanosine-5'-triphosphate binding proteins that likely had a role in motility and invasion mediated by Urotensin-II receptor. Additionally, its expression on tumour tissues is variably associated to the prediction of the clinical outcome of the patients and it can be considered an alternative molecular marker to be used as prognostic factor in human cancers. In conclusion, a new weapon in the treatment of human cancers is highlighting a new scenario for the future
Eliciting Tacit Knowledge with a Grammar-targeted Interview Method
Tacit knowledge represents a challenge to knowledge elicitation due to the assumption that this type of knowledge cannot be articulated. We argue that Polanyi's (1966:4) widely cited notion that “we know more than we can tell” represents a weak model of language that does not acknowledge the grammatical patterns in spoken discourse that we, as speakers, apply tacitly. We investigate the hypothesis that individuals articulate what they know through grammatical patterns, referred to as under-representation, without direct awareness. This thesis develops and pilots a grammar-targeted interview method aimed at unpacking specific grammatical features that occur in spoken discourse. The model of language from which these features are derived is Systemic Functional Linguistics. We report findings from three empirical studies of tacit knowledge in corporate organisations where we used the grammar-targeted interview technique to elicit tacit knowledge in the areas of knowledge management, requirements analysis and performance reviews. We compare this interview method with a content-targeted approach. The results show that the grammar-targeted technique produces less under-represented discourse thus allowing tacit knowledge held by the interviewees to be made visible. Based on the linguistic analyses undertaken in these field studies we propose that Polanyi’s expression “we know more than we tell” be reformulated to “we tell more than we realise we know”
Peptide functionalization of silicon for detection and classification of prostatic cells
The development of simple, rapid, and low costmethods for early detection, identification, andmeasurement ofmultiple biomarkers remains a challenge to improve diagnosis, treatment monitoring, and prognosis of cancer. Biosensing technology, combining the properties of biological systems with functional advanced materials, guarantees rapid, reproducible, and highly sensitive cell detection. In this study, we developed silicon-based biochips for prostate cancer PC3 cells detection by using cytokeratin 8/18 and Urotensin Receptor (UTR) as markers in order to obtain a biochip-based diagnostic system. Spectroscopic ellipsometry and fluorescence microscopy were used to characterize surface homogeneity and chemical properties. Cell detection was investigated by optical microscopy.Moreover, synthetic fluorescently labeled peptides were prepared and used for developing faster and lowercost identification assay compared with classic ELISA immunoassay. Results showed an effective immobilization of PC3 cells on silicon surface and the specific recognition of these cells by fluorescent Urotensin II (4-11). In conclusion, this strategy could be really useful as diagnostic system for prostate cancer
Special issue on HOX genes in development
This Special Issue of Journal of Developmental Biology (JDB) covers an indeed very "special" (at least to me) family of highly evolutionarily conserved genes, the Hox genes.[...]
Silybin-Phosphatidylcholine Complex Protects Human Gastric and Liver Cells from Oxidative Stress
Silybin is the main component of silymarin with antioxidant, anti-inflammatory and cytoprotective actions. Our aim was to compare the effect of silybin used as single substance, silybin-phosphatidylcholine complex (SilPho), and derivatives of silybin (MannpSil, GalpSil, GlcpSil, LactpSil) on MKN28 and HepG2 cell viability and cell death, in vitro, after induction of oxidative stress
Aggressiveness pattern and second primary tumor risk associated with basaloid squamous cell carcinoma of the larynx
Basaloid squamous cell carcinoma (BSCC) is a rare, aggressive and distinct variant of squamous cell carcinoma (SCC) of the upper respiratory and digestive tract. We have evaluated disease specific survival (DSS) and overall survival (OS) through Kaplan-Meier method and mortality risk through univariate statistical analysis of Cox in 42 cases of BSCC and other 42 of laryngeal SCC (LSCC) matched for both age and sex. We demonstrated that laryngeal BSCC is a more aggressive tumor than LSCC as is associated to higher nodal recurrence of pathology (5 vs 2 patients, median survival, OR 2.7), a reduced survival (median survival 34 vs 40 months, OR 3.2 for mortality); in addition, basaloid patients have a higher risk to be affected by second primary tumors (13 vs 3 patients, OR 5.8) and a higher probability to die for this second tumor (Hazard Risk, HR 4.4). The analysis of survival shows an increased mortality risk concurrent with the parameters assessed by univariate analyses that assume a predictive and statistical significance in second tumor and grading in basaloid LSSC.Basaloid squamous cell carcinoma (BSCC) is a rare, aggressive and distinct variant of squamous cell carcinoma (SCC) of the upper respiratory and digestive tract. We have evaluated disease specific survival (DSS) and overall survival (OS) through Kaplan-Meier method and mortality risk through univariate statistical analysis of Cox in 42 cases of BSCC and other 42 of laryngeal SCC (LSCC) matched for both age and sex. We demonstrated that laryngeal BSCC is a more aggressive tumor than LSCC as is associated to higher nodal recurrence of pathology (5 vs 2 patients, median survival, OR 2.7), a reduced survival (median survival 34 vs 40 months, OR 3.2 for mortality); in addition, basaloid patients have a higher risk to be affected by second primary tumors (13 vs 3 patients, OR 5.8) and a higher probability to die for this second tumor (Hazard Risk, HR 4.4). The analysis of survival shows an increased mortality risk concurrent with the parameters assessed by univariate analyses that assume a predictive and statistical significance in second tumor and grading in basaloid LSSC
Farms as a resilience factors to land degradation in peri-urban areas
The purpose of this study was the analysis of the effects induced by urban pressures on the socio-economic and territorial characteristics of the rural peri-urban areas in order to identify planning and intervention strategies aimed at enhancing the quality of agriculture and landscape. A survey was conducted in the surroundings of Parma on farms located in the vicinity of urban areas. The structural, productive and social characteristics of the family-farm units were analyzed. The survey updated an identical survey, carried out in 1986, in which it was examined a sample of 208 farms. The units surveyed were evaluated in two aspects: the “vitality”, which takes into account the structural characteristics (size, production, labour force, etc.), and the “stability”, in which a crucial role is played by the age of the conductor and the presence of a successor. It was found that only 28% of the original farm sample is still alive, one third has disappeared, 30% was absorbed by existing farms, 8% has been abandoned. The factors most favourable to the survival resulted those referred to the vitality, especially the physical and economic size of the farm, the presence of cattle, the percentage of land in property, the presence of young labour. Among the factors that predispose to the abandonment, the urbanization processes were found to be determinants, in terms of expansion of both the built-up area and of that planned as urbanisable. The research has highlighted the importance of the vitality of the farms together with a context that has maintained its original rural features. These combined aspects can better define what we call the resiliency of the landfarms system i.e. the capability of positively reacting to the variable modifications of the internal and external conditions
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