Kardar-Parisi-Zhang growth on one-dimensional decreasing substrates

Recent experimental works on one-dimensional (1D) circular Kardar-Parisi-Zhang (KPZ) systems whose radii decrease in time have reported controversial conclusions about the statistics of their interfaces. Motivated by this, we investigate here several 1D KPZ models on substrates whose size changes in time as $L(t)=L_0 + \omega t$, focusing on the case $\omega<0$. From extensive numerical simulations, we show that for $L_0 \gg 1$ there exists a transient regime in which the statistics is consistent with that of flat KPZ systems (the $\omega=0$ case), for both $\omega0$. Actually, for a given model, $L_0$ and $|\omega|$, we observe that a difference between ingrowing ($\omega0$) systems arises only at long times ($t \gtrsim t_c=L_0/|\omega|$), when the expanding surfaces cross over to the statistics of curved KPZ systems, whereas the shrinking ones become completely correlated. A generalization of the Family-Vicsek scaling for the roughness of ingrowing interfaces is presented. Our results demonstrate that a transient flat statistics is a general feature of systems starting with large initial sizes, regardless their curvature. This is consistent with their recent observation in ingrowing turbulent liquid crystal interfaces, but it is in contrast with the apparent observation of curved statistics in colloidal deposition at the edge of evaporating drops. A possible explanation for this last result, as a consequence of the very small number of monolayers analyzed in this experiment, is given. This is illustrated in a competitive growth model presenting a few-monolayer transient and an asymptotic behavior consistent, respectively, with the curved and flat statistics.Comment: 5 pages, 3 figure

The nature of the LINER in the galaxy NGC 404

NGC 404, at a distance of 3.4 Mpc, is the nearest S0 galaxy. This galaxy harbors a LINER; however, since the spectrum does not show a broad H{\alpha} emission, it is not certain that this LINER is a low luminosity AGN and its nature is still an open question. HST observations show the existence of stellar populations with an age of 3 x 10^8 years years in the galactic bulge and with an age of 6-15 x 10^9 years in the galactic disk. In this work, we present an analysis of the data cube of NGC 404 obtained with the IFU (Integral Field Unity) of the GMOS (Gemini Multi-Object Spectrograph) on the Gemini North telescope.Comment: 2 pages, 2 figure

One-point height fluctuations and two-point correlators of (2+1)(2+1) cylindrical KPZ systems

While the 1-point height distributions (HDs) and 2-point covariances of $(2+1)$ KPZ systems have been investigated in several recent works for flat and spherical geometries, for the cylindrical one the HD was analyzed for few models and nothing is known about the spatial and temporal covariances. Here, we report results for these quantities, obtained from extensive numerical simulations of discrete KPZ models, for three different setups yielding cylindrical growth. Beyond demonstrating the universality of the HD and covariances, our results reveal other interesting features of this geometry. For example, the spatial covariances measured along the longitudinal and azimuthal directions are different, with the former being quite similar to the curve for flat $(2+1)$ KPZ systems, while the latter resembles the Airy$_2$ covariance of circular $(1+1)$ KPZ interfaces. We also argue (and present numerical evidence) that, in general, the rescaled temporal covariance $\mathcal{A}(t/t_0)$ decays asymptotically as $\mathcal{A}(x) \sim x^{-\bar{\lambda}}$ with an exponent $\bar{\lambda} = \beta + d^*/z$, where $d^*$ is the number of interface sides kept fixed during the growth (being $d^* = 1$ for the systems analyzed here). Overall, these results complete the picture of the main statistics for the $(2+1)$ KPZ class.Comment: 10 pages, 8 figures, 2 table

Adulteration of Dietary Supplements by the Illegal Addition of Synthetic Drugs: a review

In the last few years, the consumption of dietary supplements, especially those having plants as ingredients, has been increasing due to the common idea that they are natural products posing no risks to human health. In the European Union and the United States, dietary supplements are legally considered as foods/special category of foods, thus are not being submitted to any safety assessment prior to their commercialization. Among the issues that can affect safety, adulteration by the illegal addition of pharmaceutical substances or their analogs is of major concern since unscrupulous producers can falsify these products to provide for quick effects and to increase sales. This review discusses the various classes of synthetic drugs most frequently described as being illegally added to dietary supplements marketed for weight loss, muscle building/sport performance and sexual performance enhancement. Information regarding regulation and consumption is also presented. Finally, several conventional and advanced analytical techniques used to detect and identify different adulterants in dietary supplements and therefore also in foods, with particular emphasis on plant food supplements, are critically described. This review demonstrates that dietary supplement adulteration is an emerging food safety problem and that an effective control by food regulatory authorities is needed to safeguard consumers.This work was supported by European Union (FEDER funds through COMPETE) and Natl. Funds (FCT, Fundação para a Ciência e Tecnologia) through projects EXPL/DTP-SAP/1438/2013 (Safety of plant food supplements: searching for adulterant pharmaceutical drugs and plants) and LAQV UID/QUI/50006/2013.info:eu-repo/semantics/publishedVersio

Food supplements adulteration with undeclared synthetic phosphodiesterase type-5 drugs (PDE-5) inhibitors

The use ofplant food supplements (PFS) in developed countries is becoming increasingly popular mostly due to the consumers' widespread idea that natural products are safer and healthier than conventional pharmaceutical drugs [l]. However, in the last years, several studies have been showing the existence of gaps in PFS regulation that can result in insuíficient quality control and intentional adulteration ofthese products [2]. Among the issues that can aíFect PFS safety, the illegal addition of pharmaceutical substances is of major concern, since unscrupulous producers can dope PFS to provide for quick effects. Supplements used for sexual performance improvement are among the most popular PFS used by males. One of the major concerns in this type of product is the possible adulteration with drugs used for the treatment of erectile dysfunction, namely synthetic phosphodiesterase type-5 (PDE-5) inhibitor drugs, such as sildenafil, vardenafil and tadalafil which are approved prescription drugs being marketed as Viagra (Pfizer, USA), Levitra (Bayer Pharmaceuticals Co., Germany) and Cialis (Elli Lilly, USA), respectively. Since these drugs can present side eífects, its illegal addition in PFS can seriously endanger consumers' health. In particular, individuais for whom conventional PDE-5 inhibitor drugs are contraindicated and consequently use food supplements as an alternative maybe at risk ifthe clandestine addition ofthese drugs occurs. In the last years, the presence ofthis type ofdrugs have been detected by FDA in the US, and reported in food supplements commercialized in Ásia, however studies regarding this issue in the EU are almost inexistent. For the presented reasons, an analytical methodology based on the use of high performance liquid chromatography coupled to a fluorescence detector in series with a photodiode array (HPLC-FL-PDA) is proposed for the detection ofPDE-5 inhibitors, namely sildenafil and its analogue acetildenafil, vardenafil and tadalaíil, illegally added to supplements used for aphrodisiac purposes.to FCT (PEst-C/EQB/LA0006/2013 and EXPL/DTP-SAP/1438/2013) and QREN (NORTE-07-0124-FEDER-000069-CIÊNCIA DO ALIMENTO).info:eu-repo/semantics/publishedVersio

Food supplements adulteration with undeclared synthetic phosphodiesterase type-5 drugs (PDE-5) inhibitors

The use ofplant food supplements (PFS) in developed countries is becoming increasingly popular mostly due to the consumers' widespread idea that natural products are safer and healthier than conventional pharmaceutical drugs [l]. However, in the last years, several studies have been showing the existence of gaps in PFS regulation that can result in insuíficient quality control and intentional adulteration ofthese products [2]. Among the issues that can aíFect PFS safety, the illegal addition of pharmaceutical substances is of major concern, since unscrupulous producers can dope PFS to provide for quick effects. Supplements used for sexual performance improvement are among the most popular PFS used by males. One of the major concerns in this type of product is the possible adulteration with drugs used for the treatment of erectile dysfunction, namely synthetic phosphodiesterase type-5 (PDE-5) inhibitor drugs, such as sildenafil, vardenafil and tadalafil which are approved prescription drugs being marketed as Viagra (Pfizer, USA), Levitra (Bayer Pharmaceuticals Co., Germany) and Cialis (Elli Lilly, USA), respectively. Since these drugs can present side eífects, its illegal addition in PFS can seriously endanger consumers' health. In particular, individuais for whom conventional PDE-5 inhibitor drugs are contraindicated and consequently use food supplements as an alternative maybe at risk ifthe clandestine addition ofthese drugs occurs. In the last years, the presence ofthis type ofdrugs have been detected by FDA in the US, and reported in food supplements commercialized in Ásia, however studies regarding this issue in the EU are almost inexistent. For the presented reasons, an analytical methodology based on the use of high performance liquid chromatography coupled to a fluorescence detector in series with a photodiode array (HPLC-FL-PDA) is proposed for the detection ofPDE-5 inhibitors, namely sildenafil and its analogue acetildenafil, vardenafil and tadalaíil, illegally added to supplements used for aphrodisiac purposes.to FCT (PEst-C/EQB/LA0006/2013 and EXPL/DTP-SAP/1438/2013) and QREN (NORTE-07-0124-FEDER-000069-CIÊNCIA DO ALIMENTO).info:eu-repo/semantics/publishedVersio

Towards a green and secure architecture for reconfigurable IoT end-devices

With the advent of the Internet of Things (IoT), objects are becoming smaller, smarter and increasingly connected. IoT devices are being deployed in massive numbers, and the success of this new Internet era is heavily dependent upon the trust and security built over billions of heterogeneous devices. However, securing IoT devices can be a quandary, with hardware requirements, energy consumption and cost limitations pulling in opposite directions. This work-in-progress proposes a novel architecture for reconfigurable IoT end-devices, where several constrains, such as the security, performance and power budget must be seriously considered. The proposed architecture intends to go beyond state-of-the-art by focusing on a trade-off between device security and power consumption, in an attempt to find an optimal design point in the energy-security space.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT -Fundacao para a Ciencia e Tecnologia within the Project Scope: UID/CEC/00319/2013