Procedimento de operação, manutenção e verificação de thermomixer.

bitstream/CENARGEN/29576/1/ct060.pd

Procedimento de operação, manutenção e verificação da centrífuga refrigerada de bancada Eppendorf, Modelo 5810 R.

bitstream/CENARGEN/29583/1/ct063.pd

Procedimento de operação, manutenção e verificação da estufa ELETROLAB modelo 112FC.

bitstream/CENARGEN/29586/1/ct065.pd

Procedimento de operação, manutenção e verificação do Espectrofotômetro.

bitstream/CENARGEN/29588/1/ct067.pd

Spin-glass phase transition and behavior of nonlinear susceptibility in the Sherrington-Kirkpatrick model with random fields

The behavior of the nonlinear susceptibility $\chi_3$ and its relation to the spin-glass transition temperature $T_f$, in the presence of random fields, are investigated. To accomplish this task, the Sherrington-Kirkpatrick model is studied through the replica formalism, within a one-step replica-symmetry-breaking procedure. In addition, the dependence of the Almeida-Thouless eigenvalue $\lambda_{\rm AT}$ (replicon) on the random fields is analyzed. Particularly, in absence of random fields, the temperature $T_f$ can be traced by a divergence in the spin-glass susceptibility $\chi_{\rm SG}$, which presents a term inversely proportional to the replicon $\lambda_{\rm AT}$. As a result of a relation between $\chi_{\rm SG}$ and $\chi_3$, the latter also presents a divergence at $T_f$, which comes as a direct consequence of $\lambda_{\rm AT}=0$ at $T_f$. However, our results show that, in the presence of random fields, $\chi_3$ presents a rounded maximum at a temperature $T^{*}$, which does not coincide with the spin-glass transition temperature $T_f$ (i.e., $T^* > T_f$ for a given applied random field). Thus, the maximum value of $\chi_3$ at $T^*$ reflects the effects of the random fields in the paramagnetic phase, instead of the non-trivial ergodicity breaking associated with the spin-glass phase transition. It is also shown that $\chi_3$ still maintains a dependence on the replicon $\lambda_{\rm AT}$, although in a more complicated way, as compared with the case without random fields. These results are discussed in view of recent observations in the LiHo$_x$Y$_{1-x}$F$_4$ compound.Comment: accepted for publication in PR

S 111 and the polarization of the B[e] supergiants in the Magellanic Clouds

We have obtained linear polarization measurements of the Large Magellanic Cloud B[e] supergiant S 111 using optical imaging polarimetry. The intrinsic polarization found is consistent with the presence of an axisymmetric circumstellar envelope. We have additionally estimated the electron density for S 111 using data from the literature and revisited the correlation between polarization and envelope parameters of the B[e] supergiant stars using more recent IR calibration color data. The data suggest that the polarization can be indeed explained by electron scattering. We have used Monte Carlo codes to model the continuum polarization of the Magellanic B[e] supergiants. The results indicate that the electron density distribution in their envelopes is closer to a homogeneous distribution rather than an r$^{-2}$ dependence. At the same time, the data are best fitted by a spherical distribution with density contrast than a cylindrical distribution. The data and the model results support the idea of the presence of an equatorial disk and of the two-component wind model for the envelopes of the B[e] supergiants. Spectropolarimetry would help further our knowledge of these envelopes

An Ultra-Stable Referenced Interrogation System in the Deep Ultraviolet for a Mercury Optical Lattice Clock

We have developed an ultra-stable source in the deep ultraviolet, suitable to fulfill the interrogation requirements of a future fully-operational lattice clock based on neutral mercury. At the core of the system is a Fabry-P\'erot cavity which is highly impervious to temperature and vibrational perturbations. The mirror substrate is made of fused silica in order to exploit the comparatively low thermal noise limits associated with this material. By stabilizing the frequency of a 1062.6 nm Yb-doped fiber laser to the cavity, and including an additional link to LNE-SYRTE's fountain primary frequency standards via an optical frequency comb, we produce a signal which is both stable at the 1E-15 level in fractional terms and referenced to primary frequency standards. The signal is subsequently amplified and frequency-doubled twice to produce several milliwatts of interrogation signal at 265.6 nm in the deep ultraviolet.Comment: 7 pages, 6 figure

Patterns of ultra-processed foods consumption throughout childhood and trajectories of growth and adiposity

Background & aims: Ultra-processed foods (UPF) consumption has been associated with unhealthy outcomes. However, the literature lacks robust longitudinal studies considering its cumulative effect, particularly in young populations. This study aimed to evaluate the relationship between UPF consumption patterns throughout childhood with growth and adiposity trajectories. Methods: Generation XXI population-based birth cohort (Porto, Portugal) participants were included. Food frequency questionnaire items at 4, 7 and 10 years were classified according to the processing degree using NOVA. UPF consumption patterns based on total quantity were identified using a probabilistic Gaussian mixture model using participants with complete data and predicting for the total sample (n = 8647). To assess whether the outcome trajectories from 4 to 13 years [body weight (kg), height (cm), body mass index (BMI) z-score, waist circumference (WC) (cm) and fat mass (FM) (%)] depend on UPF patterns, a mixed-effects model with linear and quadratic terms for age adjusted for confounders was used. Participants with at least 2 measurements at 4, 7, 10 or 13 years were included in this study (n range: 5885–6272). Results: Four UPF consumption patterns were identified: constantly lower consumption (15.4%), constantly intermediate consumption (56.4%), transition from low to high consumption (11.2%), and constantly higher consumption (17.1%). Compared to the constantly lower UPF consumption, the constantly higher consumption pattern was associated with greater acceleration in body weight (β: 0.119; 95%CI: 0.027; 0.212), BMI z-score (β: 0.014; 95%CI: 0.004; 0.023), WC (β: 0.232; 95%CI: 0.144; 0.319) and FM% (β: 0.200; 95%CI: 0.092; 0.308) and with lower acceleration in height (β: −0.063; 95%CI: −0.111;-0.015). The constantly intermediate UPF consumption pattern was associated with greater acceleration in body weight (β: 0.123; 95%CI: 0.043; 0.203), WC (β: 0.120; 95%CI: 0.045; 0.195) and FM% (β: 0.146; 95%CI: 0.054; 0.238). Conclusion: Constantly higher and constantly intermediate UPF consumption throughout childhood were associated with worse growth and adiposity trajectories until adolescence. © 2024 The Authors"G21 was funded by the Health Operational Programme – Saúde XXI, Community Support Framework III and the Regional Department of Ministry of Health. It was supported by the Portuguese Foundation for Science and Technology – FCT (Portuguese Ministry of Education and Science) within the scope of specific projects. This study was financed by national funds through FCT, I.P., under the Epidemiology Research Unit of the Institute of Public Health of the University of Porto (UIDB/04750/2020, UIDP/04750/2020), the Laboratory for Integrative and Translational Research in Population Health of the University of Porto (LA/P/0064/2020) and the FOCAcCIa project (POCI-01-0145-FEDER-031949). VM benefited from an FCT individual doctoral grant (SFRH/BD/143747/2019). SV is supported by national funds through FCT, under the programme of ‘Stimulus of Scientific Employment – Individual Support’ within the contract 10.54499/2021.01096.CEECIND/CP1686/CT0001 (http://doi.org/10.54499/2021.01096.CEECIND/CP1686/CT0001).