Mortalidade da borboleta migratória Aphrissa statira (Cramer, 1777) (Pieridae - Coliadinae) na BR 156, Amapá.

Resumo 14

Hyaluronan is a natural and effective immunological adjuvant for protein-based vaccines

One of the main goals of vaccine research is the development of adjuvants that can enhance immune responses and are both safe and biocompatible. We explored the application of the natural polymer hyaluronan (HA) as a promising immunological adjuvant for protein-based vaccines. Chemical conjugation of HA to antigens strongly increased their immunogenicity, reduced booster requirements, and allowed antigen dose sparing. HA-based bioconjugates stimulated robust and long-lasting humoral responses without the addition of other immunostimulatory compounds and proved highly efficient when compared to other adjuvants. Due to its intrinsic biocompatibility, HA allowed the exploitation of different injection routes and did not induce inflammation at the inoculation site. This polymer promoted rapid translocation of the antigen to draining lymph nodes, thus facilitating encounters with antigen-presenting cells. Overall, HA can be regarded as an effective and biocompatible adjuvant to be exploited for the design of a wide variety of vaccines

Geotechnical Hazards Caused by Freezing-Thawing Processes Induced by Borehole Heat Exchangers

In closed-loop Ground Source Heat Pump system (GSHP), the thermal exchange with the underground is provided by a heat-carrier fluid circulating into the probes. In order to improve the heat extraction rate during winter, the heat-carrier fluid temperature is often lowered down to 125 \ub0C; this way, the induced thermal anomaly is more intense and can cause freezing processes in the surrounding ground. In sediments with significant clay fraction, the inner structure and the porosity distribution are irreversibly altered by freezing-thawing cycles; therefore, the geotechnical properties (such as deformability, stiffness and permeability) are significantly affected. A wide laboratory program has been performed in order to measure the induced deformations and the permeability variations under different conditions of thermal and mechanical loads and interstitial water salinity. The results suggest that, despite the induced frozen condition is quite confined close to the borehole, the compaction induced in cohesive layers is significant and irreversible and could generate negative friction on the borehole heat exchanger; in addition, the permeability increase in the probe surroundings could lead interconnection among aquifers, with increasing effects with the number of boreholes in the borefield

Experimental Validation for Impedance-Based Small-Signal Stability Analysis of Single-Phase Interconnected Power Systems with Grid-Feeding Inverters

The interactions of more and more power electronics-interfaced power systems can worsen the power quality and the system stability in distribution networks. System stability can be addressed by analyzing the source and load impedances at the interaction section, and well-established approaches exist for dc and three-phase ac networks. Some papers also focused on single-phase ac systems, whose study is generally more difficult due to their time-varying characteristics. Similar to the approaches based on dq rotating frame impedances, this paper focuses on single-phase systems using the dynamic phasor approach to determine the 2-D source and load impedances. The system stability is then evaluated using the generalized Nyquist stability criterion. As an example of application, a single-phase ac system that includes a current-controlled inverter synchronized to the grid through a phase-locked loop is proposed. Experimental validations are provided herein to verify the feasibility of this approach and the stability criteria based on the 2-D source and load impedances in the single-phase systems

LEARNING AS A TOOL FOR CANCER PREVENTION THROUGH THE ACQUISITION OF NEW DIETARY HABITS AND BEHAVIORS

The need to promote knowledge of health entails, in part, by encouraging healthy eating habits. The creation of popular science materials, especially at schools, by promoting guidance for the eating habits is presented as an important tool. Foods that contain bioactive compounds are called nutraceutical foods and about 35% of various cancers occur due to inadequate diets. Conventional therapies are used in the treatment of cancer, even though they are efficient in fighting tumors, to cause many harmful effects to the patient, and therefore the researches for alternative therapies have increased. Especially those act strengthening the immunologic system. The mushrooms are able to modulate carcinogenesis in all stages of the disease through different mechanisms of action of the bioactive compounds, thus having an antitumor effect that is assigned to restore and improve the immune response through stimulation of cellular immunity which are present polysaccharides the composition of the mushrooms, such as beta-glucans that besides the anticancer effect, it still has activity as immunostimulant, antioxidant, anti-inflammatory, which are already used in Japan as drugs for treating cancer patients. The aim of this work was to use learning as a tool for acquiring habits and eating behaviors in the general community and ownership and acquisition of knowledge about the antitumor potential of bioactive compounds in foods which are applied in cancer prevention through the scientific dissemination / education. Because it is a popular science work using written material and the dissemination of the material make for yourself the methodology used for the dissemination of scientific knowledge. Thus, the inclusion of consumption of mushrooms in the diet may represent an important step in the cancer prevention as the best form of prevention, and therefore it shows the need for available information to everyone, as it has proposed this work, disclosure

Validation of impedance-based small-signal stability analysis for single-phase grid-feeding inverters with PLL

The interactions of more and more power electronics-interfaced power systems can worsen the power quality and the system stability in distribution networks. System stability can be addressed analyzing the source and load impedances at the interaction section and well-established approaches exist for DC and three-phase AC networks. Some papers focused also on single-phase AC systems, whose study is generally more difficult due to their nonlinear and time-varying characteristics. One viable solution to address this issue is the use of equivalent dq rotating reference frame even for single phase system so as to identify a steady-state operating condition. This paper uses this approach and proposes the small-signal analysis of a single-phase AC system that includes a current-controlled inverter synchronized to the grid via a Phase-Locked Loop (PLL). Experimental validations are provided herein to asses the feasibility of this approach and to verify the stability criteria based on the source and load impedances

A large number of T lymphocytes recognize Moloney-murine leukemia virus-induced antigens, but a few mediate long-lasting tumor immunosurveillance

The CD8(+) T cell response to Moloney-murine leukemia virus (M-MuLV)-induced Ags is almost entirely dominated by the exclusive expansion of lymphocytes that use preferential TCRVbeta chain rearrangements. In mice lacking T cells expressing these TCRVbeta, we demonstrate that alternative TCRVbeta can substitute for the lack of the dominant TCRVbeta in the H-2-restricted M-MuLV Ag recognition. We show that, at least for the H-2(b)-restricted response, the shift of TCR usage is not related to a variation of the immunodominant M-MuLV epitope recognition. After virus immunization, all the potentially M-MuLV-reactive lymphocytes are primed, but only the deletion of dominant Vbeta rescues the alternative Vbeta response. The mechanism of clonal T cell "immunodomination" that guides the preferential Vbeta expansion is likely the result of a proliferative advantage of T cells expressing dominant Vbeta, due to differences in TCR affinity and/or cosignal requirements. In this regard, a CD8 involvement is strictly required for the virus-specific cytotoxic activity of CTL expressing alternative, but not dominant, Vbeta gene rearrangements. The ability of T cells expressing alternative TCRVbeta rearrangements to mediate tumor protection was evaluated by a challenge with M-MuLV tumor cells. Although T cells expressing alternative Vbeta chains were activated and expanded, they were not able to control tumor growth in a long-lasting manner due to their incapacity of conversion and accumulation in the T central memory pool

Multiscale analysis of freeze\u2013thaw effects induced by ground heat exchangers on permeability of silty clays

The freeze\u2013thaw cycles artificially induced in the ground by ground source heat pump systems working at sub-zero temperatures, or during underwater soil excavation, could cause unwanted permanent effects on the hydro-mechanical behaviour of the surrounding deposits. Cohesive deposits present a specific sensitivity to these processes connected to phase changes occurring in the interstitial fluid. The experiments conducted on normally consolidated cohesive soils point out that freeze\u2013thaw cycles can cause a hysteretic increase in vertical permeability of about one order of magnitude, despite a significant concurrent reduction in void ratio. Although the induced freeze\u2013thaw processes are quite constrained close to the borehole heat exchanger, the vertical permeability increase may lead to the risk of connecting aquifers previously separated by cohesive layers, with an overall effect that increases according to the number of probes in the array. Permeability variation appears to be due to the irreversible alteration of the microstructure provoked during the development of freeze\u2013thaw processes. In this paper, the changes of the macroscale hydraulic conductivity are related to changes in the porous microstructural variations, detected in a wide dimensional range by means of a combination of X-ray computed micro tomography, scanning electron microscopy and mercury intrusion porosimetry