Breve artigo sobre a hipótese Gaia e a sua importância.

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In Fact, Fiction and Forecast, Nelson Goodman claims that the problem of justifying induction is not something over and above the problem of describing valid induction. Such claim seems to open up the possibility that the new riddle of induction could be addressed empirically. Discoveries about psychological preferences for projecting certain classes of objects could function as a criterion for determining which predicates are after all projectible. In this paper, I argue that Goodman's claim must be construed within his project for constructional definitions, which is methodologically oriented by reflective equilibrium. The description of inductive practice is committed to the articulation of the extension of the class selected by the predicate ‘valid induction’. The mutual adjustment between theoretical considerations and inductive practice involved in the proposal of a definition of ‘valid induction’ must preserve that practice as much as possible, there is no way to get rid of entrenchment. Empirical discoveries about the psychological mechanism that underlies projections may help that adjustment but they cannot substitute the role played by the entrenchment of predicates.

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OBJECTIVES: To assess the association between gingival recession (GR) and oral health-related quality of life (OHRQoL) in a Brazilian population of adults. METHODS: A representative sample from Porto Alegre city was drawn in 2011 using a multistage probability sampling strategy. For this study, 740 individuals, 35-59 years of age and with >/=6 teeth, were included. GR was assessed by two calibrated examiners at four sites in all present teeth. The Oral Health Impact Profile (OHIP-14) was used to assess OHRQoL. OHIP-14 was dichotomized using 'fairly often' as the cutoff point for a negative impact. Multiple logistic regression models were fitted to define which descriptors of GR were associated with the dichotomous outcome of OHIP-14, including dentine hypersensitivity in separate models, adjusting for age, gender, socioeconomic status, smoking, dental care, and missing teeth. RESULTS: Mean OHIP was significantly higher for individuals with >/=1 tooth with GR >/=2, >/=3, >/=4, and >/=5 mm. Individuals with >/=1 tooth with GR >/=2 mm had approximately two times higher chance of having a negative impact than individuals without GR of this threshold [odds ratio (OR) = 1.99, 95% confidence interval (CI) 1.05-3.78]. When buccal and proximal sites were analyzed separately, the presence of GR was significantly associated with worst quality of life only in anterior and not in posterior teeth. GR in the lower arch had no impact on OHRQoL. GR >/=2 mm affected only physical pain (OR = 2.61; 95% CI 1.06-6.42), whereas GR >/=4 mm affected functional limitation, physical pain, psychological discomfort, physical and psychological disabilities, with ORs ranging from 1.43 to 1.91. Dentine hypersensitivity alone was not associated with OHRQoL, but it modified the association between GR and OHIP when present concomitantly with GR, mainly in buccal sites. CONCLUSIONS: OHRQoL is poorer in this adult population in the presence of GR, mainly in upper and anterior teeth. Dentine hypersensitivity and esthetics were found to be factors linking GR to OHRQoL.

In this paper, we derive the dielectric tensor for a plasma containing particles described by an
anisotropic superthermal (bi-kappa) velocity distribution function. The tensor components are
written in terms of the two-variables kappa plasma special functions, recently defined by Gaelzer
and Ziebell [Phys. Plasmas 23, 022110 (2016)]. We also obtain various new mathematical properties for these functions, which are useful for the analytical treatment, numerical implementation,
and evaluation of the functions and, consequently, of the dielectric tensor. The formalism developed
here and in the previous paper provides a mathematical framework for the study of electromagnetic
waves propagating at arbitrary angles and polarizations in a superthermal plasma.