Broad protection against invasive fungal disease from a nanobody targeting the active site of fungal b-1,3-glucanosyltransferases.

Invasive fungal disease accounts for ~3.8 million deaths annually, an unacceptable rate that urgently prompts the discovery of new knowledge-driven treatments. We report the use of camelid single-domain nanobodies (Nbs) against fungal ß-1,3-glucanosyltransferases (Gel) involved in ß-1,3-glucan transglycosylation. Crystal structures of two Nbs with Gel4 from Aspergillus fumigatus revealed binding to a dissimilar CBM43 domain and a highly conserved catalytic domain across fungal species, respectively. Anti-Gel4 active site Nb3 showed significant antifungal efficacy in vitro and in vivo prophylactically and therapeutically against different A. fumigatus and Cryptococcus neoformans isolates, reducing the fungal burden and disease severity, thus significantly improving immunocompromised animal survival. Notably, C. deneoformans (serotype D) strains were more susceptible to Nb3 and genetic Gel deletion than C. neoformans (serotype A) strains, indicating a key role for ß-1,3-glucan remodelling in C. deneoformans survival. These findings add new insights about the role of b-1,3-glucan in fungal biology and demonstrate the potential of nanobodies in targeting fungal enzymes to combat invasive fungal diseases.

HR Gene Variants Identified in Mexican Patients with Alopecia Areata.

Alopecia Areata (AA) is a multifactorial, dermatological disease characterized by non-scarring hair loss. Alterations in candidate genes, such as HR (Hairless), could represent a risk factor for its development. The aim of this study was to search for and analyze variants in exons 3, 15 and 17 of the HR gene in Mexican patients with AA. A total of 30 samples from both AA patients and healthy donors were analyzed in this study. Exons were amplified and sequenced using the Sanger method. Descriptive statistics and χ2 tests were used in the analysis of clinical-demographic characteristics and the comparison of allelic/genotypical frequencies between groups, respectively. The effect on protein function for the non-synonymous variants was determined with three bioinformatics servers. Three gene variants were identified in the HR gene of the evaluated patients. The benign polymorphism c.1010G > A p.(Gly337Asp) (rs12675375) had been previously reported, whereas the variants c.750G > A p.(Gln250Gln) and c.3215T > A (Val1072AGlu) have not been described in other world populations. Both non-synonymous variants proved to be significant (p ≤ 0.05). The variant c.3215T > A p.(Val1072Glu) is of particular interest due to its deleterious effect on the structure and function of the protein; therefore, it could be considered a risk factor for the development of AA.

Lupus enteritis: A 10-year experience in a single Latin American center.

OBJECTIVE: The objective is to compare the clinical and laboratory characteristics of systemic lupus erythematosus (SLE) patients with and without lupus enteritis (LE) and to identify the factors associated with the occurrence of LE. METHODS: We performed a retrospective, case-control study in hospitalized patients with SLE who were admitted to our tertiary hospital between January 2012 and December 2021. Sixteen LE patients (cases) were matched (1:3 ratio) for sex and birth year with 48 non-LE patients (controls). Univariable and multivariable logistic regression analyses were used to identify the variables associated with LE. RESULTS: Of 2,479 SLE patients who were admitted to our hospital as inpatients, 16 (0.65%) were diagnosed as having LE. All patients, cases and controls, were of Mestizo ethnicity. SLE was diagnosed simultaneously with the first episode of LE in 10 (62.5%) patients. The median time from SLE diagnosis to the first episode of LE was 7 (IQR 0-78) months. LE patients had a shorter median disease duration [7 (0-78) vs 34 (9.5-79) months], and a significantly longer hospital stay (28.3 ± 15.8 vs 6.5 ± 7.9 days, p < 0.001) than non-LE patients. Most LE patients (93.8%) had concomitant lupus nephritis. LE patients had higher SLEDAI-2K scores than those without LE (20.5 ± 9.4 vs 9.8 ± 10.4, p < 0.001). By multivariable analysis, a higher SLEDAI-2K score (OR 1.10, 95% CI 1.02-1.18; p = 0.015) was independently associated with LE occurrence after adjusting for cutaneous involvement, lymphocyte count, serum creatinine, and serum complement C4. Recurrence was observed in two patients (12.5%), both with a bowel wall thickening > 8 mm. The two patients with large intestine-dominant LE developed intestinal pseudo-obstruction. No patient had life-threatening complications (intestinal hemorrhage, infarction, or perforation), and there were no deaths induced directly by LE itself. CONCLUSION: In patients of Mestizo ethnicity, LE occurs during the early course of SLE, frequently is one of the presenting manifestations of SLE, and in most cases, it presents with concomitant lupus nephritis. Higher levels of disease activity at diagnosis were independently associated with LE occurrence and when recurrences occur, they do so in the context of severe wall thickness.

[CRCP units: a strategy to assess health risks in children in contaminated communitiesUnidades RISC: uma estratégia para avaliar os riscos de saúde na população infantil de comunidades contaminadas]. / Unidades RISC: una estrategia para evaluar riesgos de salud en la población infantil de comunidades contaminadas.

Humanitarian crises can occur in places affected by chemical, physical, biological, and social threats, especially when these threats interact with each other and cause a syndemic. In order to avoid crises in these places, it is necessary to introduce mitigation measures that we have framed as "humanitarian scenarios". Due to their nature, implementation of these interventions requires the creation of multidisciplinary operational groups with a work strategy that integrates them into the affected community. In the case of the child population, the operational group was called the 'childhood risks in contaminated places' (CRCP) unit; contaminated places meaning localities impacted by chemical, physical, or biological threats. The strategy has six phases: (i) planning the survey and site visit; (ii) community involvement in identifying threats, vulnerabilities, and routes of exposure (the path of pollutants from their source to the receiving population), and in preparing joint work for the subsequent phases; iii) prioritization of risks identified through environmental monitoring and use of biomarkers of exposure and effects; iv) risk prevention through the creation of various 'capacities and alternatives for the prevention of syndemic threats'; (v) advocacy to implement these capacities and alternatives through risk communication and local training; and (vi) protection through measures that include telehealth, social progress, and innovation to improve health coverage. The strategy has been implemented in different contexts, and in some of them it has been enriched by analysis of respect for human rights.

Crises humanitárias podem ocorrer em locais afetados por ameaças químicas, físicas, biológicas e sociais, principalmente quando essas ameaças interagem entre si e causam uma sindemia. Para evitar as crises, é necessário introduzir nesses locais medidas de mitigação que enquadramos no termo "cenários humanitários". Por sua natureza, a implementação de tais ações de intervenção exige a formação de grupos operacionais multidisciplinares e de uma estratégia de trabalho que permita integrá-los à comunidade afetada. No caso da população infantil, o grupo operacional recebeu o nome de Unidade de Riscos Infantis em Áreas Contaminadas (na sigla em espanhol, RISC), ou seja, em locais impactados por ameaças químicas, físicas ou biológicas. A estratégia consiste nas seis fases a seguir: i) planejamento para o estudo e visita ao local; ii) participação da comunidade para identificar ameaças, vulnerabilidades e rotas de exposição (caminho que os contaminantes devem seguir desde a sua fonte até a população receptora), bem como para o trabalho conjunto nas fases seguintes; iii) priorização dos riscos identificados por meio do monitoramento ambiental e uso de biomarcadores de exposição e efeitos; iv) prevenção de riscos por meio da criação de diversas capacidades e alternativas para a prevenção diante de ameaças sindêmicas (CAPAS); v) promoção da implantação das CAPAS por meio da comunicação de riscos e capacitação local; e vi) proteção com medidas que incluem propostas de telessaúde, progresso social e inovação para melhorar a cobertura de saúde. A estratégia foi aplicada em diferentes contextos, em alguns dos quais foi enriquecida com uma análise do respeito pelos direitos humanos.

Rural and urban disparities in anemia among Peruvian children aged 6-59 months: a multivariate decomposition and spatial analysis.

INTRODUCTION: Anemia is a global public health issue that affects mainly children aged less than 5 years. In Peru, despite the reduction in the prevalence of anemia between 2010 and 2018, anemia remains a major concern, especially in high-risk zones such as rural areas. Several sociodemographic factors have been associated with anemia in children; however, components contributing to the urban-rural gap have not been previously assessed. The purpose of this study was to evaluate the determinants of the difference in anemia prevalence between urban and rural areas, and its spatial distribution in Peruvian children aged 6-59 months. METHODS: A secondary data analysis was conducted using the 2019 Peruvian Demographic Health Survey. The study population included 18 846 children aged 6-59 months. A multivariate decomposition analysis for non-linear response model was performed to identify the factors contributing to the gap in the prevalence of anemia across urban and rural areas. Global Moran´s I autocorrelation, Ordinary Kriging interpolation and Bernoulli-based purely spatial scan statistics were employed to assess the spatial pattern of anemia. RESULTS: Nationwide, the prevalence of anemia in Peru was 29.47% (95%CI 28.63-30.33). In rural areas, it was 38.25%, and in urban areas 26.39%. The decomposition analysis revealed that 88.61% of the difference in the prevalence of anemia between urban and rural areas was attributed to the difference in the respondents' characteristics. Wealth index, mother´s education, mother´s employment status, number of living children and mother´s age were key determinants contributing to the rural-urban gap. Spatial heterogeneity of anemia prevalence in childhood was observed at both inter- and intradepartmental level. The SaTScan spatial analysis identified six significant cluster areas with high prevalence of anemia in childhood. CONCLUSION: A considerable gap of anemia prevalence between urban and rural areas was found. Targeted interventions are necessary to reduce geographic disparities.

Determination of complex type free, non-conjugated oligosaccharide glucose unit values in tomato xylem sap for early detection of nutrient deficiency.

Although knowledge on glycan biosynthesis and processing is continuously maturing, there are still a limited number of studies that examine biological functions of N-glycan structures in plants, which remain virtually unknown. Here, the statistical correlation between nutrient (nitrogen) deficiency symptoms of crops and changes in 8-aminopyrene-1,3,6-trisulfonic acid (APTS)-labeled complex type free oligosaccharides is reported. While deficiency symptoms are predicted by multispectral images and Kjeldahl digestion, APTS-labeled complex type free oligosaccharides are identified by their glucose unit (GU) values in tomato xylem sap, using capillary electrophoresis with laser induced fluorescence detection (CE-LIF). Given the limited number of structures obtained from plants, archived in the literature, in the future, it is intended to create an open access database of promising indicators, namely, glycan structures that are presumably responsible for the nutrient deficiency caused stress in plants (http://glycoplants.org).

[Persistent foramen ovale as a cause of persistent hypoxemia after a pneumonia caused with COVID-19. Report of one case]. / Foramen oval persistente como causa de hipoxemia persistente en un paciente con neumonía grave COVID-19. Reporte de un caso.

In patients with severe COVID-19, it has been proposed as mechanism of respiratory failure, intra and extrapulmonary shunt. However, there are no reported or documented cases of this mechanism. Also, there are studies showing this mechanism is not relevant. In this report, we present the case of a patient with severe COVID-19 pneumonia, who after two months, during his rehabilitation period, presented persistent hypoxemia with orthodeoxia. Persistent oval foramen with shunt from right to left was diagnosed. The patient underwent a percutaneous closure of the defect and at 48 hours oxygen therapy could be discontinued and the patient discharged.

Impact of the Type of Analgesic Therapy on Postsurgical Complications of Patients with Kidney Cancer Undergoing Nephrectomy.

BACKGROUND: The treatment of kidney cancer usually involves surgery, and in some cases systemic therapy. Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to control postsurgical pain in patients undergoing nephrectomy for renal cancer. Nevertheless, the association between these drugs and adverse postsurgical outcomes, including deterioration of renal function, is not fully established. METHODS: This retrospective cohort study included patients >18 years old with kidney cancer undergoing nephrectomy between January 2006 and January 2018. The primary endpoint was to determine the impact of postsurgical analgesic therapy (NSAIDs vs. acetaminophen) on renal function and postsurgical complications. This study was approved by our scientific and bioethical committee. RESULTS: One hundred patients were included in the final analysis. Clear-cell renal-cell carcinoma was the most frequent histologic subtype. Adequate acute pain control was accomplished in 91% of the patients during hospitalization. Twenty percent of the patients presented postsurgical complications. Bleeding-related complications were the most frequent (9%), followed by surgical-site infection (6%) and acute renal injury (6%). The administration of NSAIDs was not related to any postsurgical complication in comparison with the use of acetaminophen (21.3 vs. 17.9%, respectively). The length of hospital stay did not differ between patients treated with NSAIDs and those treated with acetaminophen (the average stay was 4 days for both groups, p = 0.32). CONCLUSION: The use of NSAIDs was not related to acute kidney injury, postsurgical complications, or prolonged hospital stay in patients with renal cancer undergoing nephrectomy.

Coarse-Fine Convolutional Deep-Learning Strategy for Human Activity Recognition.

In the last decade, deep learning techniques have further improved human activity recognition (HAR) performance on several benchmark datasets. This paper presents a novel framework to classify and analyze human activities. A new convolutional neural network (CNN) strategy is applied to a single user movement recognition using a smartphone. Three parallel CNNs are used for local feature extraction, and latter they are fused in the classification task stage. The whole CNN scheme is based on a feature fusion of a fine-CNN, a medium-CNN, and a coarse-CNN. A tri-axial accelerometer and a tri-axial gyroscope sensor embedded in a smartphone are used to record the acceleration and angle signals. Six human activities successfully classified are walking, walking-upstairs, walking-downstairs, sitting, standing and laying. Performance evaluation is presented for the proposed CNN.

The dual orexin receptor antagonist, DORA-22, lowers histamine levels in the lateral hypothalamus and prefrontal cortex without lowering hippocampal acetylcholine.

Chronic insomnia is defined as a persistent difficulty with sleep initiation maintenance or non-restorative sleep. The therapeutic standard of care for this condition is treatment with gamma-aminobutyric acid (GABA)A receptor modulators, which promote sleep but are associated with a panoply of side effects, including cognitive and memory impairment. Dual orexin receptor antagonists (DORAs) have recently emerged as an alternative therapeutic approach that acts via a distinct and more selective wake-attenuating mechanism with the potential to be associated with milder side effects. Given their distinct mechanism of action, the current work tested the hypothesis that DORAs and GABAA receptor modulators differentially regulate neurochemical pathways associated with differences in sleep architecture and cognitive performance induced by these pharmacological mechanisms. Our findings showed that DORA-22 suppresses the release of the wake neurotransmitter histamine in the lateral hypothalamus, prefrontal cortex, and hippocampus with no significant alterations in acetylcholine levels. In contrast, eszopiclone, commonly used as a GABAA modulator, inhibited acetylcholine secretion across brain regions with variable effects on histamine release depending on the extent of wakefulness induction. In normal waking rats, eszopiclone only transiently suppressed histamine secretion, whereas this suppression was more obvious under caffeine-induced wakefulness. Compared with the GABAA modulator eszopiclone, DORA-22 elicits a neurotransmitter profile consistent with wake reduction that does not impinge on neurotransmitter levels associated with cognition and rapid eye movement sleep.

An intramembranous ossification model for the in silico analysis of bone tissue formation in tooth extraction sites.

The accurate modeling of biological processes allows us to predict the spatiotemporal behavior of living tissues by computer-aided (in silico) testing, a useful tool for the development of medical strategies, avoiding the expenses and potential ethical implications of in vivo experimentation. A model for bone healing in mouth would be useful for selecting proper surgical techniques in dental procedures. In this paper, the formulation and implementation of a model for Intramembranous Ossification is presented aiming to describe the complex process of bone tissue formation in tooth extraction sites. The model consists in a mathematical description of the mechanisms in which different types of cells interact, synthesize and degrade extracellular matrices under the influence of biochemical factors. Special attention is given to angiogenesis, oxygen-dependent effects and growth factor-induced apoptosis of fibroblasts. Furthermore, considering the depth-dependent vascularization of mandibular bone and its influence on bone healing, a functional description of the cell distribution on the severed periodontal ligament (PDL) is proposed. The developed model was implemented using the finite element method (FEM) and successfully validated by simulating an animal in vivo experiment on dogs reported in the literature. A good fit between model outcome and experimental data was obtained with a mean absolute error of 3.04%. The mathematical framework presented here may represent an important tool for the design of future in vitro and in vivo tests, as well as a precedent for future in silico studies on osseointegration and mechanobiology.

Spreaders, igniters, and burning shrubs: plant flammability explains novel fire dynamics in grass-invaded deserts.

Novel fire regimes are an important cause and consequence of global environmental change that involve interactions among biotic, climatic, and human components of ecosystems. Plant flammability is key to these interactions, yet few studies directly measure flammability or consider how multiple species with different flammabilities interact to produce novel fire regimes. Deserts of the southwestern United States are an ideal system for exploring how novel fire regimes can emerge when fire-promoting species invade ecosystems comprised of species that did not evolve with fire. In these deserts, exotic annual grasses provide fuel continuity across landscapes that did not historically burn. These fires often ignite a keystone desert shrub, the fire-intolerant creosote bush, Larrea tridentata (DC.) Coville. Ignition of Larrea is likely catalyzed by fuels produced by native plants that grow beneath the shrubs. We hypothesize that invasive and native species exhibit distinct flammability characteristics that in combination determine spatial patterns of fire spread and intensity. We measured flammability metrics of Larrea, two invasive grasses, Schismus arabicus and Bromus madritensis, and two native plants, the sub-shrub Ambrosia dumosa and the annual herb Amsinckia menziesii. Results of laboratory experiments show that the grasses carry fire quickly (1.32 cm/s), but burn for short duration (0.5 min) at low temperatures. In contrast, native plants spread fire slowly (0.12 cm/s), but burn up to eight times longer (4 min) and produced hotter fires. Additional experiments on the ignition requirements of Larrea suggest that native plants burn with sufficient temperature and duration to ignite dead Larrea branches (time to ignition, 2 min; temperature at ignition 692°C). Once burning, these dead branches ignite living branches in the upper portions of the shrub. Our study provides support for a conceptual model in which exotic grasses are "spreaders" of fire and native plants growing beneath shrubs are "igniters" of dead Larrea branches. Once burning, flames produced by dead branches engulf the entire shrub, resulting in locally intense fires without historical precedent in this system. We suggest that fire models and conservation-focused management could be improved by incorporating the distinct flammability characteristics and spatial distributions of spreaders, igniters, and keystone shrubs.

Ochronosis as Etiology of Requiring Total Knee Arthroplasty-A Case Series.

Alkaptonuria is a rare hereditary metabolic disorder that leads to the accumulation of homogentisic acid accumulation and weakens the collagen, creating fissuring and articular cartilage degeneration. Therefore, we are reporting a multicenter case series of three patients (four arthroplasties) who presented with signs and symptoms of ochronotic arthropathy-and eventually underwent total knee arthroplasty (TKA)-and provide a review of the current literature on total joint arthroplasty in ochronotic osteoarthritis. Each patient achieved excellent Knee Society Scores (KSS) after at least a five-year follow-up-regardless of receiving cemented or cementless prostheses-and suffered no complications. There have been a number of case reports published on patients who had TKA and were found to have a diagnosis of ochronosis. We believe that surgery for symptomatic patients who are surgical candidates for TKA should not be delayed for concerns of complications. However, future studies should compare outcomes to those who undergo TKA without ochronotic arthropathy.

The invasive species Ulex europaeus (Fabaceae) shows high dynamism in a fragmented landscape of south-central Chile.

Ulex europaeus (gorse) is an invasive shrub deemed as one of the most invasive species in the world. U. europaeus is widely distributed in the south-central area of Chile, which is considered a world hotspot for biodiversity conservation. In addition to its negative effects on the biodiversity of natural ecosystems, U. europaeus is one of the most severe pests for agriculture and forestry. Despite its importance as an invasive species, U. europaeus has been little studied. Although information exists on the potential distribution of the species, the interaction of the invasion process with the spatial dynamic of the landscape and the landscape-scale factors that control the presence or absence of the species is still lacking. We studied the spatial and temporal dynamics of the landscape and how these relate to U. europaeus invasion in south-central Chile. We used supervised classification of satellite images to determine the spatial distribution of the species and other land covers for the years 1986 and 2003, analysing the transitions between the different land covers. We used logistic regression for modelling the increase, decrease and permanence of U. europaeus invasion considering landscape variables. Results showed that the species covers only around 1 % of the study area and showed a 42 % reduction in area for the studied period. However, U. europaeus was the cover type which presented the greatest dynamism in the landscape. We found a strong relationship between changes in land cover and the invasion process, especially connected with forest plantations of exotic species, which promotes the displacement of U. europaeus. The model of gorse cover increase presented the best performance, and the most important predictors were distance to seed source and landscape complexity index. Our model predicted high spread potential of U. europaeus in areas of high conservation value. We conclude that proper management for this invasive species must take into account the spatial dynamics of the landscape within the invaded area in order to address containment, control or mitigation of the invasion.

Assessing the impact of fire on the spatial distribution of Larrea tridentata in the Sonoran Desert, USA.

In southwestern American deserts, fire has been historically uncommon because of insufficient continuity of fuel for spreading. However, deserts have been invaded by exotic species that now connect the empty space between shrubs to carry fire. We hypothesized that fire would change the spatial distribution of surviving Larrea tridentata shrubs. We established two study plots, one each in a burned and unburned area, and recorded location and living status of all shrubs. We performed univariate and bivariate point pattern analyses to characterize the impact of fire on the overall distribution of shrubs. Additionally, we used a simple wildfire model to determine how close we could come to reconstructing the observed spatial pattern of living and dead shrubs. We found a hyper-dispersed pattern of shrubs at finer scales and a random pattern at broader scales for both the unburned plot and for the living and dead shrubs combined in the burned plot, the latter providing an approximation of the pre-burn distribution of shrubs. After fire, living shrubs showed a clustered pattern at scales >2.5 m, whereas dead shrubs were randomly distributed, indicating that fire caused a change in the spatial pattern of the surviving shrubs. The fire model was able to partially reconstruct the spatial pattern of Larrea, but created a more clustered distribution for both living and dead shrubs. Our study reinforces the key role of fire in altering landscapes that had not been habituated to fire, and suggests the existence of potential cascading effects across the entire plant community.

Multifocal giant cell tumor of the carpus: Unusual presentation. Case report and review of the literature.

INTRODUCTION AND IMPORTANCE: Giant cell tumors (GCTs) of bone in the carpus are rare. Carpal GCTs are usually solitary lesions; multifocal involvement is exceptional. These lesions have a higher risk of local recurrence after intralesional curettage than those in other body areas. CASE PRESENTATION: We present a case of a 28-year-old male with a six-month history of a palpable mass in the dorsal aspect of the left wrist. Physical examination revealed a 2 cm, mildly tender mass. Magnetic resonance revealed a large intermediate signal lesion involving completely hamate bone and the distal portion of the triquetrum. Histological examination confirmed a giant cell tumor of the carpus. The patient underwent en-bloc resection of the hamate bone extending to the distal part of the pyramidal. The defect was reconstructed using polymethylmethacrylate cement (PMMA), and intercarpal arthrodesis with the capitate was achieved. Follow-up at 18 months revealed a good clinical evolution, wrist range of motion of 30° of extension, 30° of flexion, and 10° of ulnar and radial deviation without evidence of tumoral recurrence. CLINICAL DISCUSSION: The current literature suggests a high incidence of local recurrence in carpal GCT, so wide excision with carpal arthrodesis is recommended, especially in Campanacci III and multifocal involvement. CONCLUSION: Carpal GCT is exceptional, mainly affecting the hamate, capitate, and scaphoid. Most literature supports wide excision of carpal GCT owing to the high recurrence rate with intralesional procedures.

Strategy for the analysis of lignocellulosic biomass to select a viable transformation route in the Colombian context.

Lignocellulosic biomass is widely available in the world. However, a consensus has yet to be established to evaluate the biomass valorization alternatives. The chemical composition is the primary technical limitation in selecting a transformation route to obtain value-added products. In this paper, the bagasse from non-centrifuged sugar (NCS) production and Pinus patula (PP) wood chips were analyzed in terms of complete chemical composition to establish their potential for selecting the transformation routes. A strategy to select the best route based on the chemical composition was applied and a feedstock criteria model was proposed. Schemes were obtained and compared using a bioprocess selection strategy proposed in previous works. As a result, the preliminary biorefinery schemes were finally defined. The assessment of schemes derived from the outlined strategy included technical, economic, environmental, and social analyses. The environmental evaluation was complemented with a geolocation assessment, revealing a 0.75-ton CO2-eq/yr contribution to the carbon footprint for local distribution. The sustainability index for the PP biorefinery and the bagasse from NCS production was analyzed, resulting in indices of 44.8 and 60.9, respectively. These values were primarily derived from the economic and environmental analyses of both processes.

Heat exposure in sugarcane harvesters in Costa Rica.

BACKGROUND: Occupational heat stress is a major concern in sugarcane production and has been hypothesized as a causal factor of a chronic kidney disease epidemic in Central America. This study described working conditions of sugarcane harvesters in Costa Rica and quantified their exposure to heat. METHODS: Non-participatory observation and Wet Bulb Globe Temperatures (WBGT) according to Spanish NTP (Technical Prevention Notes) guidelines were utilized to quantify the risk of heat stress. OSHA recommendations were used to identify corresponding exposure limit values. RESULTS: Sugarcane harvesters carried out labor-intensive work with a metabolic load of 261 W/m² (6.8 kcal/min), corresponding to a limit value of 26° WBGT which was reached by 7:30 am on most days. After 9:15 am, OSHA recommendations would require that workers only work 25% of each hour to avoid health risks from heat. CONCLUSIONS: Sugarcane harvesters are at risk for heat stress for the majority of the work shift. Immediate action is warranted to reduce such exposures.

[Conflicting values in Colombia's health system: balancing the market economy and constitutional legislation, 2007-2009]. / Conflicto de valores en el sistema de salud de Colombia: entre la economía de mercado y la normativa constitucional, 2007-2009.

OBJECTIVE: To present the conflicting moral issues that arise in clinical and administrative decision-making processes in Colombia's General Health Social Security System (SGSSS). METHODS: A study was conducted between 2007 and 2009 in six Colombian cities (Barranquilla, Bogotá, Bucaramanga, Leticia, Medellín, and Pasto) using a theory-based qualitative methodology. A total of 179 in-depth interviews were held with physicians, nursing personnel, and administrators with broad experience in the health sector, as well as 10 focus groups representing users and leaders of community organizations involved in health. The interviews, which followed a predetermined script and used semistructured questions, gathered personal and professional information from the respondents. RESULTS: The health care decision-making process in Colombia is seen from two different moral perspectives: the rentier, or profit-making, motive, characterized by a neoliberal view of the market economy (the practical perspective), and the constitutional axiology of social democracy (the regulatory perspective). It was found that the utilitarian and individualistic motive predominates, in which individual and business profits are promoted over the collective interest, and this trend favors practices that undermine the rights of people and the community. CONCLUSIONS: Predominance of a morality that views the Colombian SGSSS in terms of the market model generates conditions that go against the principles and values that are supposed to guide the health system as guarantor of the right to health and human dignity. Health decisions should take into account not only technical and scientific criteria but also the principles and values involved, and consideration should be given to safeguarding them.

Foaming Properties of Lignosulfonates in the Flotation Process.

The widely used technology for the selective flotation of copper and molybdenite using sodium hydrosulfide (NaSH) to depress copper sulfides creates environmental issues related to the potential emissions of toxic hydrosulfide gas (H2S) and bad odors. Previous studies showed that molybdenite flotation can be depressed by the action of lignosulfonates, but no significant progress has been made in studying the effect that these reagents have on the foaming/frothing phenomena in flotation. The objective of this work was to investigate the foaming properties of three samples of lignosulfonates through measurements of surface tension, foamability, bubble size distributions, and water recovery. A sugared sodium lignosulfonate (NaLS), a calcium lignosulfonate (CaLS), and a sample prepared by sulphomethylation of kraft lignin (KLS) were tested. It was found that all lignosulfonates displayed surface activity that decreased with pH and was related to the degree of anionicity and molecular weight. The NaLS lignosulfonate showed the highest dynamic foamability index (DFI) value, compared to that of the CaLS and KLS samples. The lignosulfonates tested in this study strongly affected bubble size. Water recovery tests performed using flotation experiments in a two-phase system showed that the KLS and NaLS samples had the strongest effect, which correlated with the surface tension, foamability, and bubble size results.