Multiple-length-scale elastic instability mimics parametric resonance of nonlinear oscillators

Spatially confined rigid membranes reorganize their morphology in response to the imposed constraints. A crumpled elastic sheet presents a complex pattern of random folds focusing the deformation energy while compressing a membrane resting on a soft foundation creates a regular pattern of sinusoidal wrinkles with a broad distribution of energy. Here, we study the energy distribution for highly confined membranes and show the emergence of a new morphological instability triggered by a period-doubling bifurcation. A periodic self-organized focalization of the deformation energy is observed provided an up-down symmetry breaking, induced by the intrinsic nonlinearity of the elasticity equations, occurs. The physical model, exhibiting an analogy with parametric resonance in nonlinear oscillator, is a new theoretical toolkit to understand the morphology of various confined systems, such as coated materials or living tissues, e.g., wrinkled skin, internal structure of lungs, internal elastica of an artery, brain convolutions or formation of fingerprints. Moreover, it opens the way to new kind of microfabrication design of multiperiodic or chaotic (aperiodic) surface topography via self-organization.Comment: Submitted for publicatio

Imagens, narrativas e meios

Las producciones audiovisuales son construidas por medio de un lenguaje propio, el que está constituido por diversas posibilidades artísticas, estéticas. No se limita solamente a los lenguajes tradicionales, como lo oral y lo escrita. El lenguaje audiovisual va más allá, aportando al arte recursos como el movimiento de cámara, el encuadre, los ángulos de la toma, la velocidad de captación, la música, la escenografía, el silencio, así como los resultados obtenidos con la edición audiovisual, en sus diversos métodos. El concepto de cine como lenguaje audiovisual también es discutido por Kristeva (1988), que considera esta modalidad artística como poseedora de herramientas específicas de construcción narrativa, mediante la manipulación de planos, cortes, secuencias, etc. A través de un movimiento de cámara es posible orientar al espectador para que “lea” el mensaje de la obra de una determinada manera, así cómo observar una escena bajo cierto punto de vista. A través de estos movimientos podemos “sentir” tal movimiento o incluso “participar” en ese desplazamiento. Autores como Sánchez (2006, p. 106) presentan la idea de que “el cine es lenguaje”. Para él, dentro de los distintos tipos de lenguaje audiovisual presentados, se destacan los movimientos de cámara, el sonido y el montaje. Dentro del concepto de lenguaje, Manovich (2005) define que la producción digital comenzó a contar con lenguajes específicos, multimediales, en los que el montaje digital ofrece al productor una mayor diversidad de recursos audiovisuales. Este libro reúne capítulos provenientes de diversos campos de investigación, que conforman la nueva ecología mediática, específicamente en el ámbito de la imagen y la tecnología. Con este fin, los autores de Argentina, Brasil, México, Bulgaria y Ecuador, presentan sus capítulos en una construcción lógica, en el sentido de ofrecer una lectura desde una base filosófica hasta innovaciones en diversos campos del conocimiento, como el cine, el diseño, la educación, la fotografía, el periodismo, el arte y la publicidad. Los textos están escritos en portugués o español, según el idioma de origen de los autores, o de los países donde desarrollan sus investigaciones. As produções audiovisuais são construídas por meio de uma linguagem própria, a qual é constituída por diversas possibilidades artísticas, estéticas. Não se limita somente às linguagens tradicionais, como a oral e a escrita. A linguagem audiovisual vai mais além, trazendo à arte recursos como a movimentação de câmera, o enquadramento, os ângulos de tomada, a velocidade da captação, a música, o cenário, o silêncio, assim como os resultados obtidos com a montagem audiovisual, em seus diversos métodos. O conceito de cinema como linguagem audiovisual também é discutido por Kristeva (1988), que considera essa modalidade artística como detentora de ferramentas específicas de construção narrativa, através da manipulação de planos, cortes, sequências, etc. Através de um movimento de câmera é possível orientar o espectador a “ler” a mensagem da obra de determinada forma, assim como observar uma cena sob certo ponto-de-vista. Através desses movimentos podemos “sentir” tal movimento, ou mesmo “participar” dessa movimentação. Autores como Sánchez (2006, p. 106) apresentam a ideia de que “o cinema é linguagem”. Para ele, dentro dos diversos tipos de linguagem audiovisual apresentados, destacam-se os movimentos de câmera, o som e a montagem. Dentro do conceito de linguagem, Manovich (2005) define que a produção digital passou a contar com linguagens específicas, multimídia, em que a montagem digital oferece ao produtor uma maior diversidade de recursos audiovisuais. Este livro reúne capítulos provenientes de vários campos de investigação que compõem a nova ecologia midiática, especificamente no campo da imagem e da tecnologia. Para tanto, autores de Argentina, Brasil, México, Bulgária e Equador apresentam seus capítulos em uma construção lógica no sentido de oferecer leitura desde uma base filosófica até inovações em diversos campos do conhecimento, como o cinema, o design, a educação, a fotografia, o jornalismo, a arte e a publicidade. Os textos são redigidos em português ou espanhol, de acordo com o idioma de origem dos autores, ou dos países onde desenvolvem suas investigações

Phylogenetic Analysis of Seven WRKY Genes across the Palm Subtribe Attaleinae (Arecaceae) Identifies Syagrus as Sister Group of the Coconut

BACKGROUND:The Cocoseae is one of 13 tribes of Arecaceae subfam. Arecoideae, and contains a number of palms with significant economic importance, including the monotypic and pantropical Cocos nucifera L., the coconut, the origins of which have been one of the "abominable mysteries" of palm systematics for decades. Previous studies with predominantly plastid genes weakly supported American ancestry for the coconut but ambiguous sister relationships. In this paper, we use multiple single copy nuclear loci to address the phylogeny of the Cocoseae subtribe Attaleinae, and resolve the closest extant relative of the coconut. METHODOLOGY/PRINCIPAL FINDINGS:We present the results of combined analysis of DNA sequences of seven WRKY transcription factor loci across 72 samples of Arecaceae tribe Cocoseae subtribe Attaleinae, representing all genera classified within the subtribe, and three outgroup taxa with maximum parsimony, maximum likelihood, and Bayesian approaches, producing highly congruent and well-resolved trees that robustly identify the genus Syagrus as sister to Cocos and resolve novel and well-supported relationships among the other genera of the Attaleinae. We also address incongruence among the gene trees with gene tree reconciliation analysis, and assign estimated ages to the nodes of our tree. CONCLUSIONS/SIGNIFICANCE:This study represents the as yet most extensive phylogenetic analyses of Cocoseae subtribe Attaleinae. We present a well-resolved and supported phylogeny of the subtribe that robustly indicates a sister relationship between Cocos and Syagrus. This is not only of biogeographic interest, but will also open fruitful avenues of inquiry regarding evolution of functional genes useful for crop improvement. Establishment of two major clades of American Attaleinae occurred in the Oligocene (ca. 37 MYBP) in Eastern Brazil. The divergence of Cocos from Syagrus is estimated at 35 MYBP. The biogeographic and morphological congruence that we see for clades resolved in the Attaleinae suggests that WRKY loci are informative markers for investigating the phylogenetic relationships of the palm family

Systematic Review of Potential Health Risks Posed by Pharmaceutical, Occupational and Consumer Exposures to Metallic and Nanoscale Aluminum, Aluminum Oxides, Aluminum Hydroxide and Its Soluble Salts

Aluminum (Al) is a ubiquitous substance encountered both naturally (as the third most abundant element) and intentionally (used in water, foods, pharmaceuticals, and vaccines); it is also present in ambient and occupational airborne particulates. Existing data underscore the importance of Al physical and chemical forms in relation to its uptake, accumulation, and systemic bioavailability. The present review represents a systematic examination of the peer-reviewed literature on the adverse health effects of Al materials published since a previous critical evaluation compiled by Krewski et al. (2007). Challenges encountered in carrying out the present review reflected the experimental use of different physical and chemical Al forms, different routes of administration, and different target organs in relation to the magnitude, frequency, and duration of exposure. Wide variations in diet can result in Al intakes that are often higher than the World Health Organization provisional tolerable weekly intake (PTWI), which is based on studies with Al citrate. Comparing daily dietary Al exposures on the basis of “total Al”assumes that gastrointestinal bioavailability for all dietary Al forms is equivalent to that for Al citrate, an approach that requires validation. Current occupational exposure limits (OELs) for identical Al substances vary as much as 15-fold. The toxicity of different Al forms depends in large measure on their physical behavior and relative solubility in water. The toxicity of soluble Al forms depends upon the delivered dose of Al+ 3 to target tissues. Trivalent Al reacts with water to produce bidentate superoxide coordination spheres [Al(O2)(H2O4)+ 2 and Al(H2O)6 + 3] that after complexation with O2•−, generate Al superoxides [Al(O2•)](H2O5)]+ 2. Semireduced AlO2• radicals deplete mitochondrial Fe and promote generation of H2O2, O2 • − and OH•. Thus, it is the Al+ 3-induced formation of oxygen radicals that accounts for the oxidative damage that leads to intrinsic apoptosis. In contrast, the toxicity of the insoluble Al oxides depends primarily on their behavior as particulates. Aluminum has been held responsible for human morbidity and mortality, but there is no consistent and convincing evidence to associate the Al found in food and drinking water at the doses and chemical forms presently consumed by people living in North America and Western Europe with increased risk for Alzheimer\u27s disease (AD). Neither is there clear evidence to show use of Al-containing underarm antiperspirants or cosmetics increases the risk of AD or breast cancer. Metallic Al, its oxides, and common Al salts have not been shown to be either genotoxic or carcinogenic. Aluminum exposures during neonatal and pediatric parenteral nutrition (PN) can impair bone mineralization and delay neurological development. Adverse effects to vaccines with Al adjuvants have occurred; however, recent controlled trials found that the immunologic response to certain vaccines with Al adjuvants was no greater, and in some cases less than, that after identical vaccination without Al adjuvants. The scientific literature on the adverse health effects of Al is extensive. Health risk assessments for Al must take into account individual co-factors (e.g., age, renal function, diet, gastric pH). Conclusions from the current review point to the need for refinement of the PTWI, reduction of Al contamination in PN solutions, justification for routine addition of Al to vaccines, and harmonization of OELs for Al substances

Dietary phytochemicals, HDAC inhibition, and DNA damage/repair defects in cancer cells

Genomic instability is a common feature of cancer etiology. This provides an avenue for therapeutic intervention, since cancer cells are more susceptible than normal cells to DNA damaging agents. However, there is growing evidence that the epigenetic mechanisms that impact DNA methylation and histone status also contribute to genomic instability. The DNA damage response, for example, is modulated by the acetylation status of histone and non-histone proteins, and by the opposing activities of histone acetyltransferase and histone deacetylase (HDAC) enzymes. Many HDACs overexpressed in cancer cells have been implicated in protecting such cells from genotoxic insults. Thus, HDAC inhibitors, in addition to unsilencing tumor suppressor genes, also can silence DNA repair pathways, inactivate non-histone proteins that are required for DNA stability, and induce reactive oxygen species and DNA double-strand breaks. This review summarizes how dietary phytochemicals that affect the epigenome also can trigger DNA damage and repair mechanisms. Where such data is available, examples are cited from studies in vitro and in vivo of polyphenols, organosulfur/organoselenium compounds, indoles, sesquiterpene lactones, and miscellaneous agents such as anacardic acid. Finally, by virtue of their genetic and epigenetic mechanisms, cancer chemopreventive agents are being redefined as chemo- or radio-sensitizers. A sustained DNA damage response coupled with insufficient repair may be a pivotal mechanism for apoptosis induction in cancer cells exposed to dietary phytochemicals. Future research, including appropriate clinical investigation, should clarify these emerging concepts in the context of both genetic and epigenetic mechanisms dysregulated in cancer, and the pros and cons of specific dietary intervention strategies