Advances in image processing and analysis as well as machine learning techniques have contributed to the use of biometric recognition systems in daily people tasks. These tasks range from simple ...access to mobile devices to tagging friends in photos shared on social networks and complex financial operations on self-service devices for banking transactions. In China, the use of these systems goes beyond personal use becoming a country's government policy with the objective of monitoring the behavior of its population. On July 05th 2021, the Brazilian government announced acquisition of a biometric recognition system to be used nationwide. In the opposite direction to China, Europe and some American cities have already started the discussion about the legality of using biometric systems in public places, even banning this practice in their territory. In order to open a deeper discussion about the risks and legality of using these systems, this work exposes the vulnerabilities of biometric recognition systems, focusing its efforts on the face modality. Furthermore, it shows how it is possible to fool a biometric system through a well-known presentation attack approach in the literature called morphing. Finally, a list of ten concerns was created to start the discussion about the security of citizen data and data privacy law in the Age of Artificial Intelligence (AI).
In this paper, we studied the development of a selective lithium ion sensor constituted of a carbon paste electrode modified (CPEM) with an aluminum-doped spinel-type manganese oxide (Li
1.05Al
...0.02Mn
1.98O
4) for investigating the influence of a doping ion in the sensor response. Experimental parameters, such as influence of the lithium concentration in the activation of the sensor by cyclic voltammetry, pH of the carrier solution and selectivity for Li
+ against other alkali and alkaline-earth ions were investigated. The sensor response to lithium ions was linear in the concentration range 5.62
×
10
−5 to 1.62
×
10
−3
mol
L
−1 with a slope 100.1
mV/decade over a wide pH 10 (Tris buffer) and detection limit of 2.75
×
10
−5
mol
L
−1, without interference of other alkali and alkaline-earth metals, demonstrating that the Al
3+ doping increases the structure stability and improves the potentiometric response and sensitivity of the sensor. The super-Nernstian response of the sensor in pH 10 can be explained by mixed potential arising from two equilibria (redox and ion-exchange) in the spinel-type manganese oxide.
In areas where schistosomiasis is endemic, a negative correlation is observed between atopy and helminth infection, associated with a low prevalence of asthma. We investigated whether Schistosoma ...mansoni infection or injection of parasite eggs can modulate airway allergic inflammation in mice, examining the mechanisms of such regulation. We infected BALB/c mice with 30 S. mansoni cercariae or intraperitoneally injected 2,500 schistosome eggs, and experimental asthma was induced by ovalbumin (OVA). The number of eosinophils in bronchoalveolar lavage fluid was higher in the asthmatic group than in asthmatic mice infected with S. mansoni or treated with parasite eggs. Reduced Th2 cytokine production, characterized by lower levels of interleukin-4 (IL-4), IL-5, and immunoglobulin E, was observed in both S. mansoni-treated groups compared to the asthmatic group. There was a reduction in the number of inflammatory cells in lungs of S. mansoni-infected and egg-treated mice, demonstrating that both S. mansoni infection and the egg treatment modulated the lung inflammatory response to OVA. Only allergic animals that were treated with parasite eggs had increased numbers of CD4 super(+) CD25 super(+) Foxp3 super(+) T cells and increased levels of IL-10 and decreased production of CCL2, CCL3, and CCL5 in the lungs compared to the asthmatic group. Neutralization of IL-10 receptor or depletion of CD25 super(+) T cells in vivo confirmed the critical role of CD4 super(+) CD25 super(+) Foxp3 super(+) regulatory T cells in experimental asthma modulation independent of IL-10.
Pseudomonas syringae produces highly efficient biological ice nuclei (IN) that were proposed to influence precipitation by freezing water in clouds. This bacterium may be capable of dispersing ...through the atmosphere, having been reported in rain, snow, and cloud water samples. This study assesses its survival and maintenance of IN activity under stressing conditions present at high altitudes, such as UV radiation within clouds. Strains of the pathovars syringae and garcae were compared to Escherichia coli. While UV-C effectively inactivated these cells, the Pseudomonas were much more tolerant to UV-B. The P. syringae strains were also more resistant to radiation from a solar simulator, composed of UV-A and UV-B, while only one of them suffered a decline in IN activity at -5 °C after long exposures. Desiccation at different relative humidity values also affected the IN, but some activity at -5 °C was always maintained. The pathovar garcae tended to be more resistant than the pathovar syringae, particularly to desiccation, though its IN were found to be generally more sensitive. Compared to E. coli, the P. syringae strains appear to be better adapted to survival under conditions present at high altitudes and in clouds.
One of the models used for studying cancer is the Ehrlich ascites tumor (EAT) due to its ability to grow in liquid suspension, allowing a standard number of cells to be inoculated, growth ...quantification and regression of tumor mass. Among the oncostatic substances, melatonin has shown effectiveness in limiting the tumor cell proliferation. However, studies have shown contradictory effects of melatonin on the EAT. This study has investigated the melatonin effect on tumor growth, time and survival percentage, ultrastructure and metastasis of EAT cells in mice submitted or not to pinealectomy.
Animals were inoculated with 5 x 10
cells/ml and treated or not with exogenous melatonin with doses of at 150 and 300μg/30g animal weight for 12days. Melatonin significantly reduced the abdominal circumference, volume of ascites liquid and EAT-cell viability, raising rates of time and mice survival percentage.
Ultrastructurally, the melatonin treatment revealed changes in the shape of cells, the cell surface showed numerous projections, some bifurcated, cytoplasmic vacuolation, mitochondrial degeneration and nuclear fragmentation, peculiar characteristics of apoptosis. Histopathology revealed no metastasis in the liver, small intestine and large intestine in any of the animals in the experimental groups; however this process was evident in the lungs and kidneys, being inhibited by melatonin administration.
Thus, we can conclude that doses of 150 and 300μg/30g of melatonin for 12 consecutive days have a very effective oncostatic and cytotoxic activity on EAT cells in mice.
The low regeneration potential of the central nervous system (CNS) represents a challenge for the development of new therapeutic strategies. Mesenchymal stem cells (MSCs) have been proposed as a ...possible therapeutic tool for CNS disorders. In addition to their differentiation potential, it is well accepted nowadays that their beneficial actions can also be mediated by their secretome. Indeed, it was already demonstrated, both in vitro and in vivo, that MSCs are able to secrete a broad range of neuroregulatory factors that promote an increase in neurogenesis, inhibition of apoptosis and glial scar formation, immunomodulation, angiogenesis, neuronal and glial cell survival, as well as relevant neuroprotective actions on different pathophysiological contexts. Considering their protective action in lesioned sites, MSCs’ secretome might also improve the integration of local progenitor cells in neuroregeneration processes, opening a door for their future use as therapeutical strategies in human clinical trials. Thus, in this review we analyze the current understanding of MSCs secretome as a new paradigm for the treatment of CNS neurodegenerative diseases.
...over the last decade, the use of stem cells has remarkably been proposed as a regenerative tool, and within it, MSCs have emerged as a promising therapeutic option. ...the secretome strategy ...overcomes the cells survival upon transplantation; second, secretome compounds have lower cell surface proteins expression, providing less immunogenicity when compared to living and proliferative cells (Vizoso et al., 2017); third, using the secretome as a ready-to-use product remarkably reduce the significant high number of cells needed for transplantation (7 × 106 cells/kg), as well as possible phenotypic and therapeutic potential alterations due to long periods of expansion of MSCs in vitro prior to transplantation; fourth, higher rates of production are possible through the use of dynamic controlled laboratory conditions (e.g., bioreactors (Teixeira et al., 2016)), providing a convenient source of bioactive factors; fifth, in the form of conditioned media, MSCs secretome use is more economical and practical for clinical applications, as it avoids invasive cell collection procedures; sixth, MSCs secretome obtained for therapeutic applications could be modified to desired cell-specific effects; seventh, time and cost of expansion and maintenance of cultured stem cells could be greatly reduced and off-the-shelf secretome therapies could be immediately available for treatment; eighth, MSCs secretome may be evaluated for safety, dosage and potency in a similar manner to the conventional pharmaceutical compounds; and finally, MSCs secretome storage can be performed with safety and without losing product potency, discarding the use of potential toxic cryoprotectant agents (Vizoso et al., 2017). ...the use of secretome as whole or its components per se, has advantages over the transplantation of cells themselves, as the few clinical trials already performed so far by using this concept revealed safety and feasibility, with no adverse effects being reported (US National Institutes of Health, http://ClinicalTrials.gov), thereby indicating secretome as a source of bioactive agents that can be efficiently stored and transported as a ready to use biological product. ...there is still not a fulfilled and standard list of biomolecules or (mi)RNAs to be quantified, which have led to a range of studies that selected their own or appropriated molecules of interest, instead of considering secretome composition as a whole (Phelps et al., 2018). ...studies (including from our group) have recently indicated that the secretome of MSCs from different tissues sources has different secretory profiles and distinct exosomal compositions (Pires et al., 2016), thereby indicating that such difference in their secretion pattern may indicate that their secretome or derived vesicles may be specific to a (pathological) condition.
PDF
