1,151 research outputs found
Contribució a la flora dels macromicets de l'illa de Mallorca
Com a resultat de les prospeccions micològiques realitzades a Mallorca entre els anys 1983 i 1990, donem a conèixer un catàleg de 218 taxons (8 Ascomycetes i 210 Basidiomycetes), dels quals creiem que 74 corresponen a citacions noves per a l'illa. En destaquem, entre d'altres: Cordyceps militaris (L.) Link, Daldinia vernicosa (Schw.) Ces. et de Not., Dichomitus campestris (Quél.) Domanski et Ori., Agaricus lanipes (Moell. et Schaeff.) Sing., Amanita boudieri Barla, Clitocybe lituus (Fr.) Metr., Hygrocybe reai Mre., Inocybe tenebrosa Quél., Leucopaxillus tricolor (Peck) Kühn, i Russula seperina Dupain
Compatibility testing of spacecraft materials and space-storable liquid propellants
Compatibility measurements were made for aluminum 2219-T87 alloy and titanium 6Al-4V alloy in the presence of liquid fluorine and flox. Results of post test characterization after exposure durations of 61 and 70 weeks are presented. Results of the total test program are analyzed
The Asymptotic Giant Branches of GCs: Selective Entry Only
The handful of available observations of AGB stars in Galactic Globular
Clusters suggest that the GC AGB populations are dominated by cyanogen-weak
stars. This contrasts strongly with the distributions in the RGB (and other)
populations, which generally show a 50:50 bimodality in CN band strength. If it
is true that the AGB populations show very different distributions then it
presents a serious problem for low mass stellar evolution theory, since such a
surface abundance change going from the RGB to AGB is not predicted by stellar
models. However this is only a tentative conclusion, since it is based on very
small AGB sample sizes. To test whether this problem really exists we have
carried out an observational campaign specifically targeting AGB stars in GCs.
We have obtained medium resolution spectra for about 250 AGB stars across 9
Galactic GCs using the multi-object spectrograph on the AAT (2df/AAOmega). We
present some of the preliminary findings of the study for the second parameter
trio of GCs: NGC 288, NGC 362 and NGC 1851. The results indeed show that there
is a deficiency of stars with strong CN bands on the AGB. To confirm that this
phenomenon is robust and not just confined to CN band strengths and their
vagaries, we have made observations using FLAMES/VLT to measure elemental
abundances for NGC 6752.We present some initial results from this study also.
Our sodium abundance results show conclusively that only a subset of stars in
GCs experience the AGB phase of evolution. This is the first direct, concrete
confirmation of the phenomenon.Comment: 4 pages, to appear in conference proceedings of "Reading the book of
globular clusters with the lens of stellar evolution", Rome, 26-28 November
201
Some Open Points in Nonextensive Statistical Mechanics
We present and discuss a list of some interesting points that are currently
open in nonextensive statistical mechanics. Their analytical, numerical,
experimental or observational advancement would naturally be very welcome.Comment: 30 pages including 6 figures. Invited paper to appear in the
International Journal of Bifurcation and Chao
Síndrome de Mauriac: Uma Apresentação Rara de Uma Doença Mais Comum
Introdução: A diabetes mellitus tipo
1 (DM1) é uma doença metabólica crónica
cuja incidência anual tem vindo a
aumentar. Pode cursar com alterações
sistémicas, como a hepatomegalia e o
atraso de crescimento, decorrentes de
controlo glicémico inadequado.
Caso clínico: Adolescente de 14 anos com o diagnóstico de DM1 desdeos três anos de idade e com mau controlo glicémico, internada numa Unidade de Cuidados Intensivos por cetoacidose grave. Do exame objectivo destacavam-se baixa estatura, hepatomegalia não dolorosa e estadio pubertário P1, M2 de Tanner. Analiticamente apresentava aumento das transaminases, hipercolestorolemia
e hipertrigliceridemia.
Discussão: A síndrome de Mauriac,
caracteriza -se por: DM tipo 1 mal controlada, baixa estatura, atraso pubertário, hipercolesterolémia, aumento das transaminases e hepatomegalia por depósito hepático de glicogénio.
O mecanismo fi siopatológico não
está totalmente esclarecido, sendo provavelmente a combinação de vários factores etiológicos.
É uma situação rara, cujo diagnóstico,
essencialmente clínico, assume extrema
importância dada a reversibilidade do
quadro com a optimização terapêutica
Nonadditive entropy and nonextensive statistical mechanics - Some central concepts and recent applications
We briefly review central concepts concerning nonextensive statistical
mechanics, based on the nonadditive entropy . Among others, we focus on
possible realizations of the -generalized Central Limit Theorem, including
at the edge of chaos of the logistic map, and for quasi-stationary states of
many-body long-range-interacting Hamiltonian systems.Comment: 15 pages, 9 figs., to appear in Journal of Physics: Conf.Series (IOP,
2010
A investigação enquanto prática de deliberação curricular: o caso do projecto ICR
Este artigo refere-se a um projecto de investigação curricular colaborativa que
nasceu da conjugação entre, por um lado, a preocupação de alguns professores do
ensino básico com o desinteresse manifestado por determinados alunos em relação à escola e ao currículo e, por outro, o interesse de alguns professores universitários em estudar questões de relevância curricular. Dessa conjugação resultou a assunção de uma dimensão investigativa na prática profissional dos referidos professores do ensino básico, concretizada num projecto de investigação-acção colaborativa conduzido por uma equipa de quatro docentes universitários e dez docentes do ensino básico (todos os ciclos), que têm estudado a problemática do reconhecimento (ou não), por parte dos alunos, da relevância das aprendizagens escolares. A recolha de dados tem sido feita em sucessivos ciclos de investigação-acção, com a duração de um ano escolar cada, principalmente através do registo sistemático de manifestações de desinteresse (por parte dos alunos em relação ao currículo) observadas nas aulas e de entrevistas aos alunos, conduzidas pelos seus professores. Os dados têm sido analisados pelos próprios professores do ensino básico, com o apoio dos docentes universitários, e sujeitos a interpretações individuais e de equipa, sendo essas interpretações inspiradoras de novas estratégias de ensino, que são continuamente monitorizadas e revistas. Os processos já amadurecidos e os resultados já gerados sugerem que, apesar da existência de algumas dificuldades, é possível desenvolver nas escolas do ensino básico práticas de gestão curricular que integrem uma componente de
investigação.ABSTRACT: This article describes a project of collaborative research on curriculum, which
was created by a team that includes (1) elementary school teachers worried about the
lack of interest shown by some of their students with regard to the school and the
curriculum, and (2) university professors interested in studying issues of curriculum
relevance. This partnership has contributed to an increased use of research in classrooms by those elementary school teachers, through an action research project focused on students’ acknowledgment of the relevance of what they learn in school. Data has been collected in successive cycles of action research, mainly through classroom field notes that provide evidence of given students’ lack of interest with
regard to the curriculum, and through interviews conducted by the teachers. Each action research cycle is one school year long. Data have been analyzed by the elementary school teachers, sometimes with support from the university professors, and interpreted both individually and collectively. Such interpretation of data inspires
teachers in designing new teaching strategies, which are continuously monitored and
reviewed. The processes that have already been consolidated and the results that have already been generated by this project suggest that, despite some difficulties, it is possible to develop curricula in elementary schools in ways that entail research
Tunable Nb superconducting resonators based upon a Ne-FIB-fabricated constriction nanoSQUID
Hybrid superconducting--spin systems offer the potential to combine highly
coherent atomic quantum systems with the scalability of superconducting
circuits. To fully exploit this potential requires a high quality-factor
microwave resonator, tunable in frequency and able to operate at magnetic
fields optimal for the spin system. Such magnetic fields typically rule out
conventional Al-based Josephson junction devices that have previously been used
for tunable high- microwave resonators. The larger critical field of niobium
(Nb) allows microwave resonators with large field resilience to be fabricated.
Here, we demonstrate how constriction-type weak links, patterned in parallel
into the central conductor of a Nb coplanar resonator using a neon focused ion
beam (FIB), can be used to implement a frequency-tunable resonator. We study
transmission through two such devices and show how they realise high quality
factor, tunable, field resilient devices which hold promise for future
applications coupling to spin systems
The relationship between sensory sensitivity and autistic traits in the general population.
Individuals with Autism Spectrum Disorders (ASDs) tend to have sensory processing difficulties (Baranek et al. in J Child Psychol Psychiatry 47:591–601, 2006). These difficulties include over- and under-responsiveness to sensory stimuli, and problems modulating sensory input (Ben-Sasson et al. in J Autism Dev Disorders 39:1–11, 2009). As those with ASD exist at the extreme end of a continuum of autistic traits that is also evident in the general population, we investigated the link between ASD and sensory sensitivity in the general population by administering two questionnaires online to 212 adult participants. Results showed a highly significant positive correlation (r = .775, p < .001) between number of autistic traits and the frequency of sensory processing problems. These data suggest a strong link between sensory processing and autistic traits in the general population, which in turn potentially implicates sensory processing problems in social interaction difficulties
Ageing in the critical contact process: a Monte Carlo study
The long-time dynamics of the critical contact process which is brought
suddenly out of an uncorrelated initial state undergoes ageing in close analogy
with quenched magnetic systems. In particular, we show through Monte Carlo
simulations in one and two dimensions and through mean-field theory that
time-translation invariance is broken and that dynamical scaling holds. We find
that the autocorrelation and autoresponse exponents lambda_{Gamma} and lambda_R
are equal but, in contrast to systems relaxing to equilibrium, the ageing
exponents a and b are distinct. A recent proposal to define a non-equilibrium
temperature through the short-time limit of the fluctuation-dissipation ratio
is therefore not applicable.Comment: 18 pages, 7 figures, Latex2e with IOP macros; final for
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