1,050 research outputs found
CVD of CrO2 Thin Films: Influence of the Deposition Parameters on their Structural and Magnetic Properties
This work reports on the synthesis of CrO2 thin films by atmospheric pressure
CVD using chromium trioxide (CrO3) and oxygen. Highly oriented (100) CrO2 films
containing highly oriented (0001) Cr2O3 were grown onto Al2O3(0001) substrates.
Films display a sharp magnetic transition at 375 K and a saturation
magnetization of 1.92 Bohr magnetons per f.u., close to the bulk value of 2
Bohr magnetons per f.u. for the CrO2.
Keywords: Chromium dioxide (CrO2), Atmospheric pressure CVD, Spintronics.Comment: 5 pages, 6 figure
Exercise Can Improve Speed of Behavior in Older Drivers
The main aim of this research was to study the effects of a specific exercise program
on the speed of behavior of older adults during on-the-road driving. Twenty-six
drivers (55–78 yr old) were randomly assigned to either an exercise group or a
control group. The exercise program (3 sessions of 60 min/wk for 8 wk) incorporated
tasks that induced the participants to respond quickly to challenging situations.
On-the-road driving tasks (under single- and dual-task conditions) included
measures of simple and choice reaction time, movement time, and response time.
Significant positive effects were found at follow-up resulting from participation
in the exercise program: Improvements were found for several measures in all
driving tasks, and a composite score reflected a better general drivers’ speed of
behavior. These results show that exercise can enhance speed of behavior in older
drivers and should therefore be promoted
Manifolds associated with -colored regular graphs
In this article we describe a canonical way to expand a certain kind of
-colored regular graphs into closed -manifolds by
adding cells determined by the edge-colorings inductively. We show that every
closed combinatorial -manifold can be obtained in this way. When ,
we give simple equivalent conditions for a colored graph to admit an expansion.
In addition, we show that if a -colored regular graph
admits an -skeletal expansion, then it is realizable as the moment graph of
an -dimensional closed -manifold.Comment: 20 pages with 9 figures, in AMS-LaTex, v4 added a new section on
reconstructing a space with a -action for which its moment graph is
a given colored grap
The different facets of organelle interplay - an overview of organelle interactions
ReviewThis Document is Protected by copyright and was first published by Frontiers. All rights reserved. it is reproduced with permission.Membrane-bound organelles such as mitochondria, peroxisomes, or the endoplasmic reticulum (ER) create distinct environments to promote specific cellular tasks such as ATP production, lipid breakdown, or protein export. During recent years, it has become evident that organelles are integrated into cellular networks regulating metabolism, intracellular signaling, cellular maintenance, cell fate decision, and pathogen defence. In order to facilitate such signaling events, specialized membrane regions between apposing organelles bear distinct sets of proteins to enable tethering and exchange of metabolites and signaling molecules. Such membrane associations between the mitochondria and a specialized site of the ER, the mitochondria associated-membrane (MAM), as well as between the ER and the plasma membrane (PAM) have been partially characterized at the molecular level. However, historical and recent observations imply that other organelles like peroxisomes, lysosomes, and lipid droplets might also be involved in the formation of such apposing membrane contact sites. Alternatively, reports on so-called mitochondria derived-vesicles (MDV) suggest alternative mechanisms of organelle interaction. Moreover, maintenance of cellular homeostasis requires the precise removal of aged organelles by autophagy—a process which involves the detection of ubiquitinated organelle proteins by the autophagosome membrane, representing another site of membrane associated-signaling. This review will summarize the available data on the existence and composition of organelle contact sites and the molecular specializations each site uses in order to provide a timely overview on the potential functions of organelle interaction.BBSRCFP-7-PEOPLE-2012-Marie Curie-ITN 316723 PERFUMEPortuguese Foundation for Science and Technology (FCT
Recent advances in the manipulation of circularly polarised light with cellulose nanocrystal films
This work is funded by FEDER funds through the COMPETE 2020 Program, National Funds through FCT - Portuguese Foundation for Science and Technology and POR Lisboa2020 , under the projects with references POCI- 01-0145-FEDER-007688 (Reference UID/CTM/50025), UID/BIA/00329/2013, PTDC/CTM-BIO/6178/2014, M-ERA-NET2/0007/2016 (CellColor) and PTDC/CTM-REF/30529/2017. S.N. Fernandes and L.F. Lopes acknowledge the Minister of Science, Technology and Higher Education for National Funds , European Social Funds and FCT for fellowships number SFRH/BDP/78430/2011 and SFRH/BPD/84478/2012 , respectively. This work was supported by the Histology and Comparative Pathology laboratory [Electron Microscopy service] of the Instituto de Medicina Molecular JoĂŁo Lobo Antunes, specifically Andreia Pinto for her kind support. We would like to thank Carlos Silva for providing the C. chrysina specimen. The C. aurata specimen observed was provided by the Insect Collection of the National Museum of Natural History and Science, University of LisboSignificant advances have been made to control the iridescence and the selective reflection of left circularly polarised (LCP) light, and transmission of right circularly polarised (RCP) light of solid films prepared from cellulose nanocrystals (CNCs). However the manipulation of the photonic properties of the CNCs films, which reflect both RCP and LCP light is less investigated. Solid films prepare from natural sources as CNCs have advantageous characteristics that are absent in other synthetic structures, such as wide availability and renewability. Here we review and compare recent research activity involving the production and characterization of photonic band gap structures resulting from an anisotropic layer inserted between two cholesteric layers with different helical pitches but the same handedness. We make connections between systems existing in Nature and synthetic ones with the hope of advancing in the production and manipulation of CNCs-based photonic structures.authorsversionpublishe
Extended BRST invariance in topological Yang Mills theory revisited
Extended BRST invariance (BRST plus anti-BRST invariances) provides in
principle a natural way of introducing the complete gauge fixing structure
associated to a gauge field theory in the minimum representation of the
algebra. However, as it happens in topological Yang Mills theory, not all gauge
fixings can be obtained from a symmetrical extended BRST algebra, where
antighosts belong to the same representation of the Lorentz group of the
corresponding ghosts. We show here that, at non interacting level, a simple
field redefinition makes it possible to start with an extended BRST algebra
with symmetric ghost antighost spectrum and arrive at the gauge fixing action
of topological Yang Mills theory.Comment: Interaction terms heve been included in all the calculations. Two
references added. Version to be published in Phys. Rev. D. 7 pages, Latex, no
figure
HĂbridos e variedades de milho para produção de grĂŁos e silagem - RondĂ´nia, safra 2005/06.
O objetivo desta Circular TĂ©cnica Ă© a indicação para a safra 2005/06, de sete cultivares de milho, sendo quatro variedades de polinização aberta destinadas Ă agricultura familiar, e trĂŞs hĂbridos (duplo e triplo) de linhagens para cultivo medianamente tecnificado na Ă©poca normal ou em “safrinha”. Para o manejo cultural adequado das cultivares de milho, sugeriu-se as Ă©pocas de semeadura, as principais exigĂŞncias fĂsicas e quĂmicas dos solos e as regiões homogĂŞneas de cultivo e adaptação. Alerta-se tambĂ©m, acerca dos aspectos comerciais dos grĂŁos e dos principais riscos biolĂłgicos (pragas ou doenças) que podem influenciar na performance agronĂ´mica destas cultivares de milho desenvolvidas pela Embrapa. A partir deste conjunto de informações tĂ©cnicas, espera-se contribuir com a elevação das produtividades de grĂŁos, a redução das perdas de produção e a viabilização tanto da agricultura familiar quanto daquelas em fase de tecnificação nas diferentes regiões do Estado de RondĂ´nia.bitstream/item/72113/1/0000004002-CT74-milho.pd
New insights into the peroxisomal protein inventory: Acyl-CoA oxidases and -dehydrogenases are an ancient feature of peroxisomes
Journal ArticleCopyright © 2014 Elsevier B.V. All rights reserved.Peroxisomes are ubiquitous organelles which participate in a variety of essential biochemical pathways. An intimate interrelationship between peroxisomes and mitochondria is emerging in mammals, where both organelles cooperate in fatty acid β-oxidation and cellular lipid homeostasis. As mitochondrial fatty acid β-oxidation is lacking in yeast and plants, suitable genetically accessible model systems to study this interrelationship are scarce. Here, we propose the filamentous fungus Ustilago maydis as a suitable model for those studies. We combined molecular cell biology, bioinformatics and phylogenetic analyses and provide the first comprehensive inventory of U. maydis peroxisomal proteins and pathways. Studies with a peroxisome-deficient Δpex3 mutant revealed the existence of parallel and complex, cooperative β-oxidation pathways in peroxisomes and mitochondria, mimicking the situation in mammals. Furthermore, we provide evidence that acyl-CoA dehydrogenases (ACADs) are bona fide peroxisomal proteins in fungi and mammals and together with acyl-CoA oxidases (ACOX) belong to the basic enzymatic repertoire of peroxisomes. A genome comparison with baker's yeast and human gained new insights into the basic peroxisomal protein inventory shared by humans and fungi and revealed novel peroxisomal proteins and functions in U. maydis. The importance of our findings for the evolution and function of the complex interrelationship between peroxisomes and mitochondria in fatty acid β-oxidation is discussed.Portuguese Foundation for Science and Technology (FCT)FEDER/COMPETEBBSRCCRUP/Treaty of Windso
Time-to-Arrival and Useful Field of View: Associations with Reported Driving Difficulties Among Older Adults
The purpose of this study was to determine self-reported driving difficulties related to time-to-arrival (TTA) and/or useful field of view (UFOV), to identify associations between TTA and UFOV, and to compare the TTA estimated accuracy between different vehicle speed approaches. Thirty-eight male and female active drivers ages 61 to 81 years (70,2 ± 5,0 years) participated in this study. The UFOV® test was applied. TTA was studied with a removal paradigm, using two vehicle speeds (50 and 70km/h) for data collection. A driving habits questionnaire was administered, including items concerning driving difficulties. Results showed that lower performances in divided attention (subtest 2 of UFOV®) were significantly associated with reported difficulties in hightraffic intersections, trouble seeing the signs in time to respond to them, and problems judging the speed or distance of an approaching vehicle. Concerning TTA, greater response bias and/or greater response inconsistency were significantly associated with difficulties in overtaking other cars, difficulties seeing the signs in time to react to them, difficulties in the speed or distance perception of an oncoming vehicle. Low associations were found between UFOV and TTA measures. TTA estimated accuracy increased when the vehicle traveled at higher speeds. We concluded that both TTA and UFOV seem to be important measures to identify driving difficulties in older adults. The TTA could be relevant in measuring specific aspects of visual information processing in addition to other instruments like UFOV®
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