2,537 research outputs found
New and interesting records of Brazilian bryophytes
This paper presents data on morphology, ecology and distribution of 16 species of bryophytes collected in Pernambuco, Brazil, that are interesting floristic records. Notothylasorbicularis (Schwein.) Sull. is new to Brazil, 11 species are new to the Northeast region of Brazil and 4 species are new to Pernambuco.Dados morfológicos, ecológicos e de distribuição geográfica são apresentados para 16 espécies de briófitas coletadas no Estado de Pernambuco, Brasil. Notothylas orbicularis (Schwein.) Sull. é registrada pela primeira vez para o Brasil, 11 espécies são novas para a região Nordeste e 4 para o Estado de Pernambuco
Lower left temporal-frontal connectivity characterizes expert and accurate performance: High-alpha T7-Fz connectivity as a marker of conscious processing during movement
The Theory of Reinvestment argues that conscious processing can impair motor performance. The present study tested the utility of left temporal-frontal cortical connectivity as a neurophysiological marker of movement specific conscious processing. Expert and novice golfers completed putts while temporal-frontal connectivity was computed using high alpha Inter Site Phase Clustering (ISPC) and then analyzed as a function of experience (experts versus novices), performance (holed versus missed putts), and pressure (low versus high). Existing evidence shows that left temporal to frontal connectivity is related to dispositional conscious processing and is sensitive to the amount of declarative knowledge acquired during learning. We found that T7-Fz ISPC, but not T8-Fz ISPC, was lower in experts than novices, and lower when putts were holed than missed. Accordingly, our findings provide additional evidence that communication between verbal/language and motor areas of the brain during preparation for action and its execution is associated with poor motor performance. Our findings validate high-alpha left temporal-frontal connectivity as a neurophysiological correlate of movement specific conscious processin
Pricing methods for α-quantile and perpetual early exercise options based on Spitzer identities
We present new numerical schemes for pricing perpetual Bermudan and American options as well as α-quantile options. This includes a new direct calculation of the optimal exercise boundary for early-exercise options. Our approach is based on the Spitzer identities for general Lévy processes and on the Wiener–Hopf method. Our direct calculation of the price of α-quantile options combines for the first time the Dassios–Port–Wendel identity and the Spitzer identities for the extrema of processes. Our results show that the new pricing methods provide excellent error convergence with respect to computational time when implemented with a range of Lévy processes
Achieving macro- and micro-roughness on Ti alloy by etching without prior sandblasting: a surface characterization
INTRODUCTION: Etching is currently the most popular method used to texture the surface of dental implants. Sandblasting prior to etching (SLA) is the only method to achieve a macro- and micro-surface texture with a Sa in the 1-2 μm range, a ‘moderately rough’ surface considered to be an optimized surface. However, SLA surfaces harbor remnant particles from the sandblasting process [l]. Some manufacturers consider the residual alumina particles as a foreign material worth getting rid of. Subsequently, they forgo an optimized moderately rough surface and stick to a ‘minimally rough’ micro-roughened surface displaying a Sa < 1 μm [l].
It has been recently claimed [2] that acid etching is typically not an appropriate treatment for α-β alloys because its biphasic nature leads to an enrichment of the Vanadium-rich β-phase on the surface.
The aim of the present paper is to show that it is feasible to achieve an optimized ‘moderately rough’ macro- and micro-textured surface on titanium alloy (Ti6Al4V) through etching only, without any prior sandblasting and to characterize the resulting surface
Growth, mortality, recruitment and other fishery parameters of the Nailon shell <i>Paphia textile</i> (Gmelin 1791) in Leyte
Poly(ADP-ribosyl)ation is involved in the epigenetic control of TET1 gene transcription
TET enzymes are the epigenetic factors involved in the formation of the Sixth DNA base 5-hydroxymethylcytosine, whose deregulation has been associated with tumorigenesis. In particular, TET1 acts as tumor suppressor preventing cell proliferation and tumor metastasis and it has frequently been found down-regulated in cancer. Thus, considering the importance of a tight control of TET1 expression, the epigenetic mechanisms involved in the transcriptional regulation of TET1 gene are here investigated. The involvement of poly(ADP-ribosyl)ation in the control of DNA and histone methylation on TET1 gene was examined. PARP activity is able to positively regulate TET1 expression maintaining a permissive chromatin state characterized by DNA hypomethylation of TET1 CpG island as well as high levels of H3K4 trimethylation. These epigenetic modifications were affected by PAR depletion causing TET1 downregulation and in turn reduced recruitment of TET1 protein on HOXA9 target gene. In conclusion, this work shows that PARP activity is a transcriptional regulator of TET1 gene through the control of epigenetic events and it suggests that deregulation of these mechanisms could account for TET1 repression in cancer
- …