Chaos edges of zz-logistic maps: Connection between the relaxation and sensitivity entropic indices

Chaos thresholds of the $z$-logistic maps $x_{t+1}=1-a|x_t|^z$ $(z>1; t=0,1,2,...)$ are numerically analysed at accumulation points of cycles 2, 3 and 5. We verify that the nonextensive $q$-generalization of a Pesin-like identity is preserved through averaging over the entire phase space. More precisely, we computationally verify $\lim_{t \to\infty}< S_{q_{sen}^{av}} >(t)/t= \lim_{t \to\infty}(t)/t \equiv \lambda_{q_{sen}^{av}}^{av}$, where the entropy $S_{q} \equiv (1- \sum_i p_i^q)/ (q-1)$ ($S_1=-\sum_ip_i \ln p_i$), the sensitivity to the initial conditions $\xi \equiv \lim_{\Delta x(0) \to 0} \Delta x(t)/\Delta x(0)$, and $\ln_q x \equiv (x^{1-q}-1)/ (1-q)$ ($\ln_1 x=\ln x$). The entropic index $q_{sen}^{av}0$ depend on both $z$ and the cycle. We also study the relaxation that occurs if we start with an ensemble of initial conditions homogeneously occupying the entire phase space. The associated Lebesgue measure asymptotically decreases as $1/t^{1/(q_{rel}-1)}$ ($q_{rel}>1$). These results led to (i) the first illustration of the connection (conjectured by one of us) between sensitivity and relaxation entropic indices, namely $q_{rel}-1 \simeq A (1-q_{sen}^{av})^\alpha$, where the positive numbers $(A,\alpha)$ depend on the cycle; (ii) an unexpected and new scaling, namely $q_{sen}^{av}(cycle n)=2.5 q_{sen}^{av}(cycle 2)+ \epsilon$ ($\epsilon=-0.03$ for $n=3$, and $\epsilon = 0.03$ for $n=5$).Comment: 5 pages, 5 figure

Ensemble averages and nonextensivity at the edge of chaos of one-dimensional maps

Ensemble averages of the sensitivity to initial conditions $\xi(t)$ and the entropy production per unit time of a {\it new} family of one-dimensional dissipative maps, $x_{t+1}=1-ae^{-1/|x_t|^z}(z>0)$, and of the known logistic-like maps, $x_{t+1}=1-a|x_t|^z(z>1)$, are numerically studied, both for {\it strong} (Lyapunov exponent $\lambda_1>0$) and {\it weak} (chaos threshold, i.e., $\lambda_1=0$) chaotic cases. In all cases we verify that (i) both $[\ln_q x \equiv (x^{1-q}-1)/(1-q); \ln_1 x=\ln x]$ and $<S_q > [S_q \equiv (1-\sum_i p_i^q)/(q-1); S_1=-\sum_i p_i \ln p_i]$ {\it linearly} increase with time for (and only for) a special value of $q$, $q_{sen}^{av}$, and (ii) the {\it slope} of $$and that of$$ {\it coincide}, thus interestingly extending the well known Pesin theorem. For strong chaos, $q_{sen}^{av}=1$, whereas at the edge of chaos, $q_{sen}^{av}(z)<1$.Comment: 5 pages, 5 figure

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 $S_q=k\frac{1-\sum_{i}p_i^q}{q-1} (q \in {\cal R}; S_1=-k\sum_{i}p_i \ln p_i)$. Among others, we focus on possible realizations of the $q$-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

From second to first order transitions in a disordered quantum magnet

We study the spin-glass transition in a disordered quantum model. There is a region in the phase diagram where quantum effects are small and the phase transition is second order, as in the classical case. In another region, quantum fluctuations drive the transition first order. Across the first order line the susceptibility is discontinuous and shows hysteresis. Our findings reproduce qualitatively observations on LiHo$_x$Y$_{1-x}$F$_4$. We also discuss a marginally stable spin-glass state and derive some results previously obtained from the real-time dynamics of the model coupled to a bath.Comment: 4 pages, 3 figures, RevTe

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

O secretariado e a modernização da administração pública: a implementação de serviços eficientes

O presente artigo pretende evidenciar a necessária mudança de paradigma no que se refere à capacidade de um profissional qualificado em secretariado, no mundo contemporâneo, bem como à necessária abrangência dos seus conhecimentos e das suas competências. Pretende-se ainda apresentar um projeto de implementação do Balcão Único de Atendimento (BUA) na Câmara Municipal de Moimenta da Beira, no sentido de adequar os seus serviços ao atual paradigma competitivo, que exige da Administração Pública uma postura moderna e dinamizadora que incremente a melhoria constante dos seus serviços, de forma a responder às exigências de eficiência, eficácia, transparência e qualidade dos seus clientes

Identification of non-tuberculous mycobacteria isolated from opossum (Didelphis virginiana) lymph nodes and characterisation of lesions

The aim of this study was to investigate the presence of NTM in the lymph nodes of opossums (D. virginiana) and to characterise the microscopic changes in affected tissue. Retropharyngeal and tracheobronchial lymph nodes were collected postmortem from 18 opossums in the state of Colima, Mexico in 2013. The lymph nodes were also cultured for mycobacterial organisms and processed for histopathological examination. Bacteriological cultures yielded 5/18X100 (28%) isolates of NTM, which were subsequently identified as M. terrae, M. szulgai, M. gastri and M. asiaticum. Microscopic examination of the affected nodes revealed a necrotic granulomatous lymphadenitis (3/60%) composed of histiocytes, epithelioid cells and giant cells with intralesional alcoholresistant acid bacteria. An association between the sex of the opossum and the presence of NTM was observed. To our knowledge, this is the first report of NTM isolation in opossums with granulomatous lymphadenitis in Mexico

MARS – A Fresh Look at Risk Assessment Modelling and Effective Safety Data Communication

Aviation industry’s safety management is strictly regulated since the introduction of Safety Management System (SMS) concept and its propagation through the industry and literature. Safety and Risk are in the focus of the constant research ranging from strictly technical and technological to organisational influence. Still effective and practical assessing and communicating the risk is a challenge thus diminishing optimal enhancing of organisations’ safety level. The paper will analyse the literature for the SMS in aviation for their ability to account for the complex dynamics from which safety in these kinds of systems tends to emerge – or not. Evolution of safety assessment methods and methodologies (including) the systemic models (RAG, FRAM, STAMP) will be presented. After this, it will introduce MARS as a model by describing the general features and their connection with biometrics for varied practical and theoretical reasons. Conceptual description and presentation of the model will be followed by presenting mathematical approach in the model. General presentation of mathematical approach will be applied to a case study involving aviation organisation and related data (related to Human, Technical and Environment factors). Finally one of these factors will be defined and analysed more in detail demonstrating the effectiveness and application of the MARS on the operational data

Intraoperative frozen section assessment of sentinel lymph nodes in the operative management of women with symptomatic breast cancer

<p>Abstract</p> <p>Background</p> <p>Maximisation of the potential of sentinel lymph node biopsy as a minimally invasive method of axillary staging requires sensitive intraoperative pathological analysis so that rates of re-operation for lymphatic metastases are minimised. The aim of this study was to describe the test parameters of the frozen section evaluation of sentinel node biopsy for breast cancer compared to the gold standard of standard permanent pathological evaluation at our institution.</p> <p>Methods</p> <p>The accuracy of intraoperative frozen section (FS) of sentinel nodes was determined in 94 consecutive women undergoing surgery for clinically node negative, invasive breast cancer (37:T1 disease; 43:T2; 14:T3). Definitive evidence of lymphatic spread on FS indicated immediate level II axillary clearance while sentinel node "negativity" on intraoperative testing led to the operation being curtailed to allow formal H&E analysis of the remaining sentinel nodal tissue.</p> <p>Results</p> <p>Intraoperative FS correctly predicted axillary involvement in 23/30 patients with lymphatic metastases (76% sensitivity rate) permitting definitive surgery to be completed at the index operation in 87 women (93%) overall. All SN found involved on FS were confirmed as harbouring tumour cells on subsequent formal specimen examination (100% specificity and positive predictive value) with 16 patients having additional non-sentinel nodes found also to contain tumour. Negative Predictive Values were highest in women with T1 tumours (97%) and lessened with more local advancement of disease (T2 rates: 86%; T3: 75%). Of those with falsely negative FS, three had only micrometastatic disease.</p> <p>Conclusion</p> <p>Intraoperative FS reliably evaluates the status of the sentinel node allowing most women complete their surgery in a single stage. Thus SN can be offered with increased confidence to those less likely to have negative axillae hence expanding the population of potential beneficiaries.</p