Greenhouse gas emissions from managed peatlands have not been extensively studied in Western Patagonia. The objective of this study was to assess the annual CO2 emission from microbial carbon (C) ...mineralization in a peatland site under not saturated conditions at Tierra del Fuego. The annual CO2 emissions were measured from unsaturated soil samples (n = 41) under soil incubation at seasonal local temperatures to simulate CO2 emissions for a year, using a non‐dispersive infrared gas analyser. Spatial models for total soil C and CO2 were calculated using discrete and continuous variables. The annual mean of measured cumulative CO2 was 1,358 µg CO2 g soil−1, lower than Northern peatlands, and 82% of the C mineralization occurred in the warmer season. The modelled CO2 in the warmer season showed levels of CO2 as high as 4 mg CO2 g soil−1, but 66% of the area showed between 600–2000 µg CO2 g soil−1, which is 28%–92% and 9%–32% of CO2 values reported for crop rotations. Consequently, after a potential habilitation of the study area for agricultural use, the soil CO2 emissions from heterotrophic activity would become a C source to the global CO2 emissions. This ecosystem is highly exposed to the effects of the land‐use change, and global temperature increase.
The construction industry has extensively applied the fast-tracking approach to the demanding need for the fast delivery of infrastructure projects. However, the fast-track strategy might be ...threatened by distinctive risks or changes in risk characteristics that emerge when activities are overlapped (overlapping risks). This article proposes a risk assessment simulation model to quantify the economic impact of overlapping risks on fast-track infrastructure projects. The model uses Monte Carlo simulation and a proprietary engine solution for the optimization procedure. It quantifies the overlapping risk impacts in the project duration and cost that could originate in three different overlapping degrees and evaluates the optimal overlapping degree to reduce the impact of the overlapping risks. The model demonstration used a commercial renovation project. The results suggest that overlapping risks have a high potential impact on the total cost, although with a high probability of attaining the target duration. Eight top risks affected the total duration, cost, or both. The optimum overlapping to reduce the economic impact and achieve the target project duration combines different overlapping degrees. This study contribution is a model for fast-track projects considering overlapping risks, their impact characteristic as a distribution, and the potential relationship between these risks.
Summary Population-based cancer registries generate estimates of incidence and survival that are essential for cancer surveillance, research, and control strategies. Although data on cancer stage ...allow meaningful assessments of changes in cancer incidence and outcomes, stage is not recorded by most population-based cancer registries. The main method of staging adult cancers is the TNM classification. The criteria for staging paediatric cancers, however, vary by diagnosis, have evolved over time, and sometimes vary by cooperative trial group. Consistency in the collection of staging data has therefore been challenging for population-based cancer registries. We assembled key experts and stakeholders (oncologists, cancer registrars, epidemiologists) and used a modified Delphi approach to establish principles for paediatric cancer stage collection. In this Review, we make recommendations on which staging systems should be adopted by population-based cancer registries for the major childhood cancers, including adaptations for low-income countries. Wide adoption of these guidelines in registries will ease international comparative incidence and outcome studies.
Nosema ceranae is a worldwide distributed midgut parasite of western honey bees, leading to dwindling colonies and their collapse. As a treatment, only fumagillin is available, causing issues like ...resistance and hampered bee physiology. This study aimed to evaluate ApiHerb® and Api-Bioxal® as treatments against N. ceranae. The efficacy was tested using two qPCR methods based on the 16S rRNA and Hsp70 genes. In addition, these methods were compared for their aptitude for the quantification of the infection. For this, 19 colonies were selected based on the presence of N. ceranae infections. The colonies were divided into three groups: treated with ApiHerb, Api-Bioxal with previous queen caging and an untreated control. All colonies were sampled pre- and post-treatment. The bees were analyzed individually and in duplicate with both qPCR methods. All bees in the pre-treatment tested positive for N. ceranae. Both treatments reduced the abundance of N. ceranae, but ApiHerb also decreased the prevalence of infected bees. Analysis with the 16S rRNA method resulted in several orders of magnitude more copies than analysis with the Hsp70 method. We conclude that both products are suitable candidates for N. ceranae treatment. From our analysis, the qPCR method based on the Hsp70 gene results as more apt for the exact quantification of N. ceranae as is needed for the development of veterinary medicinal products.
El presente artículo revisa uno de los planteamientos centrales en la teoría de Norbert Lechner, quien fue uno de los intelectuales más representativos de los estudios de subjetividad política en ...América Latina. A partir del diagnóstico de una crisis de Estado operada por su funcionamiento como instrumento de dominación, el autor formula una concepción de éste como forma y razón histórica, es decir, como un referente imaginario que medie las relaciones sociales entre la praxis cotidiana y la institucionalidad. Para Lechner, es en los espacios microfísicos donde se despliega la lucha hegemónica que debe ser representada por un interés general. Sin esa mediación y sin contenido ético, el Estado deviene en mero aparato reproductor de relaciones capitalistas. Proponemos que la búsqueda de una conceptualización con perspectiva histórica, se constituye en una de las bases que sustentan la teoría de la subjetividad política de Norbert Lechner.
Pectin-based hydrogels for biomedical applications have attracted recent attention due to their low cost, large availability of the materials, and high levels of biocompatibility. Specifically, ...periodate-oxidized pectin has been combined with chitosan and gelatin to form different structures. However, hydrogen peroxide-mediated oxidation of pectin has not been studied for this application; furthermore, there is little information on the effect of the degree of oxidation on hydrogel characteristics nor has the feasibility of these systems as controlled drug delivery matrices been explored. Thus, the present work proposes to study the properties of gelatin-peroxide-oxidized pectin hydrogels as drug delivery systems in wound dressing applications. Combinations of pectin at different degrees of oxidation (high, low, and native pectin) and gelatin were analyzed and tested by swelling properties, reswelling from xerogel and aerogel forms, SEM, FTIR, and drug release. It was determined that hydrogels that contained oxidized pectin had improved swelling ratios and stability, at 32°C, compared to those with native pectin and only gelatin. The porosity of the oxidized pectin hydrogels allowed to have sustained and high release rates, which would make them an attractive alternative for wound dressings.
In nature, tissues are patterned, but most biomaterials used in human applications are not. Patterned biomaterials offer the opportunity to mimic spatially segregating biophysical and biochemical ...properties found in nature. Engineering such properties allows to study cell-matrix interactions in anisotropic matrices in great detail. Here, we developed alginate-based hydrogels with patterns in stiffness and degradation, composed of distinct areas of soft non-degradable (Soft-NoDeg) and stiff degradable (Stiff-Deg) material properties. The hydrogels exhibit emerging patterns in stiffness and degradability over time, taking advantage of dual crosslinking: Diels-Alder covalent crosslinking (norbornene-tetrazine, non degradable) and UV-mediated peptide crosslinking (matrix metalloprotease sensitive peptide, enzymatically degradable). The materials were mechanically characterized using rheology for single-phase and surface micro-indentation for patterned materials. 3D encapsulated mouse embryonic fibroblasts (MEFs) allowed to characterize the anisotropic cell-matrix interaction in terms of cell morphology by employing a novel image-based quantification tool. Live/dead staining showed no differences in cell viability but distinct patterns in proliferation, with higher cell number in Stiff-Deg materials at day 14. Patterns of projected cell area became visible already at day 1, with larger values in Soft-NoDeg materials. This was inverted at day 14, when larger projected cell areas were identified in Stiff-Deg. This shift was accompanied by a significant decrease in cell circularity in Stiff-Deg. The control of anisotropic cell morphology by the material patterns was also confirmed by a significant increase in filopodia number and length in Stiff-Deg materials. The novel image-based quantification tool was useful to spatially visualize and quantify the anisotropic cell response in 3D hydrogels with stiffness-degradation spatial patterns. Our results show that patterning of stiffness and degradability allows to control cell anisotropic response in 3D and can be quantified by image-based strategies. This allows a deeper understanding of cell-matrix interactions in a multicomponent material.
Display omitted
•Alginate-based hydrogels with stiffness-degradation spatial patterns•Indentation of patterned gels match bulk mechanical testing in single phase gels•Novel image-based tool to spatially visualize and quantify cell response in anisotropic materials•Anisotropic patterns in cell proliferation and morphology emerge over time•Patterns in cell projected area, circularity, filopodia number and length emerge over time
Concurrent engineering through overlapping of activities (i.e., fast-tracking) has been used as a schedule acceleration technique. Fast-track construction projects are generally recognized as riskier ...and subject to risks arising due to the concurrency of work. This work reports the risk perception of construction professionals to three different degrees of overlapping. Semi-structured interviews were used to collect the data, and the analysis applied data transformation and descriptive statistics. The risks were mainly perceived in the middle degree of overlapping and in activities occurring earlier in the schedule. The low and high degrees of overlapping were mainly perceived as having no risk or not being feasible, respectively. The four risk types accounted for most of the perceived threats: construction error, design change, crew interference, and poor construction productivity. The findings of this study suggest that construction professionals perceive risks differently based on the amount of activity overlapping. It is consistent with previous studies that found that risks decrease as the project advances and that fast-track projects face additional risks.
PDF
