Punching shear strength of flat slab edge column connections with outward eccentricity of loading

Thirteen tests were carried out to investigate the effect of outwards eccentricity on the punching resistance of flat slab edge column connections. The slabs measured 2350 x 1700 mm (92.5 x 66.9 in.) on plan and were 180 mm (7.1 in.) thick. One end of the slab was supported on a 300 mm (11.8 in.) square column with a boot at its base for imposition of eccentricity. The other end was supported on a fixed roller support that extended across the full slab width of 1700 mm (66.9 in.). Four point loads were applied to the unsupported slab edges. The tested variables were eccentricity and the areas of flexural, shear, and torsion reinforcement. Presented test results include reinforcement strains, displacements, rotations, crack patterns, failure modes, and ultimate loads. The ACI 318 design procedure for punching shear at edge columns with outwards eccentricity is shown to be overly conservative unless the interaction between punching shear and unbalanced moment is reduced as permitted by the code. The EC2 design procedure is unsatisfactory and a modification is proposed

Health status and labor force participation : evidence for urban low and middle income individuals in Colombia

This paper analyzes the relationship between individual health status and labor force participation using the first wave of the Colombian Longitudinal Survey. The empirical modeling strategy accounts for the presence of potential endogeneity between these two variables. The results show that there is a positive relationship between health and labor force participation in both directions, indicating that better health is likely to lead to a higher probability of participation in the labor market, but also that individuals who participate in the labor market are more likely to report better health. Interesting differences are uncovered when comparing the results by gender and/or age groups. For instance, for younger females, health status and higher education positively affect the probability of labor participation, whereas having children under the age of 5 and being married reduce their probability of participation. Our findings also highlight the importance of public policy to guarantee good health conditions of the population which could also have a positive impact on labor productivity and consequently on long-run economic growth.info:eu-repo/semantics/publishedVersio

Habitat fragmentation and the future structure of tree assemblages in a fragmented Atlantic forest landscape

The biodiversity value of human-modified landscapes has become a central question in the tropical forest conservation biology, yet the degree to which plant populations and communities are restructured in response to environmental change remains unclear. Here, we address tree species density in a fragmented Atlantic forest landscape to test the hypothesis that tree assemblages inhabiting edge-dominated forest habitats approach typical conditions of early successional systems. Seedlings and adults from 141 tree species were sampled across 39 0.1-ha plots: 19 in small fragments (55 % of all tree species exhibiting higher densities in small fragments than in mature forest, particularly pioneers (>60 % of all species). Seedlings and adults of these proliferating species differed from species exhibiting population declines in terms of wood density and seed size, respectively. Additionally, pioneers were more abundant than shade-tolerant species, as were hardwood species in the case of seedlings. Tree species showing highest population increases consisted largely of long-lived, light-demanding canopy species bearing soft or hardwood and small-to-medium-sized seeds. Tree assemblage structure also differed in terms of forest habitats with small forest fragments supporting few rare species, whereas the most rapidly proliferating species were much more widespread and abundant in fragments. However, 60 % of all adult pioneer species recorded in small fragments were not recorded as seedlings in this habitat type, although both seedling and adult assemblages were dominated by pioneer species. Edge-dominated tree assemblages are likely to experience long-term shifts toward greater dominance of long-lived, pioneer canopy species

Perspectives on the Trypanosoma cruzi-host cell receptor interaction

Chagas disease is caused by the parasite Trypanosoma cruzi. The critical initial event is the interaction of the trypomastigote form of the parasite with host receptors. This review highlights recent observations concerning these interactions. Some of the key receptors considered are those for thromboxane, bradykinin, and for the nerve growth factor TrKA. Other important receptors such as galectin-3, thrombospondin, and laminin are also discussed. Investigation into the molecular biology and cell biology of host receptors for T. cruzi may provide novel therapeutic targets

Cyclic Fatigue of Different Nickel-Titanium Rotary Instruments: A Comparative Study

Since the introduction of nickel-titanium alloy to endodontics, there have been many changes in instrument design, but no significant improvements in the raw material properties, or enhancements in the manufacturing process. Recently, a new method to produce nickel-titanium rotary (NTR) instruments has been developed, in an attempt to obtain instruments that are more flexible and resistant to fatigue. NTR instruments produced using the process of twisting (TF, SybronEndo, Orange, CA) were compared to NTR instruments from different manufacturers produced by a traditional grinding process. The aim of the study was to investigate whether cyclic fatigue resistance is increased for TF NTR files. Tests were performed with a cyclic fatigue device that evaluated cycles to failure of rotary instruments inside curved artificial canals. Results indicated that size 06-25 TF instruments showed a significant increase (P< .05). In the mean number of cycles to failurewhen compared to the other tested 06-25 NTR. Hence, it can be concluded that size 06-25 TF NTR instruments were found to be significantly more resistant to fatigue than those produced with the traditional grinding process

Serum biomarkers associated with SARS-CoV-2 severity

Immunity with SARS-CoV-2 infection during the acute phase is not sufficiently well understood to differentiate mild from severe cases and identify prognostic markers. We evaluated the immune response profile using a total of 71 biomarkers in sera from patients with SARS-CoV-2 infection, confirmed by RT-PCR and controls. We correlated biological marker levels with negative control (C) asymptomatic (A), nonhospitalized (mild cases-M), and hospitalized (severe cases-S) groups. Among angiogenesis markers, we identified biomarkers that were more frequently elevated in severe cases when compared to the other groups (C, A, and M). Among cardiovascular diseases, there were biomarkers with differences between the groups, with D-dimer, GDF-15, and sICAM-1 higher in the S group. The levels of the biomarkers Myoglobin and P-Selectin were lower among patients in group M compared to those in groups S and A. Important differences in cytokines and chemokines according to the clinical course were identified. Severe cases presented altered levels when compared to group C. This study helps to characterize biological markers related to angiogenesis, growth factors, heart disease, and cytokine/chemokine production in individuals infected with SARS-CoV-2, offering prognostic signatures and a basis for understanding the biological factors in disease severity