Water requirements for growth and survival of Swietenia macrophylla and Tabebuia heterophylla juvenile trees in relation to water production capacity of dew condensers1

Drought mortality of juvenile trees is a major cause for failure of reforestation projects. Portable devices such as passive radiative dew condensers can often provide 0.15 L/day of water in situ, possibly sufficient for tree survival until roots can access groundwater, allowing self-sustainability. To evaluate growth and survivability of juvenile trees of Tabebuia heterophylla Britton and Swietenia macrophylla King under such low water amounts, juvenile trees received approximately 0.033, 0.067, 0.134, 0.201 and 0.268 L/tree/day, representing fractions (relative evapotranspiration or RET) of 0.125, 0.25, 0.50, 0.75 and 1.00 of the evapotranspiration demand (ETo). The experiment lasted 60 days for S. macrophylla and 90 days for T. heterophylla. All T. heterophylla juvenile trees survived even at the lowest irrigation rate. However, S. macrophylla juvenile trees began dying at RET \u3c 0.5, with only 60 percent surviving at RET = 0.25 (0.067 L/day) and 100 percent mortality occurring at RET = 0.125 (0.033 L/day). Water requirements of 0.134 L/day, necessary for full survival of both species, were within the typical production capacity of 1-m2 dew condensers. However, a greater safetyfactor is obtained using drought tolerant species such as T. heterophylla, which can survive under water application rates as low as 0.03 L/day

Evaluación preliminar de condensadores de rocío y su utilización para riego de plántulas de árboles en Puerto Rico

Dew condensers have been proposed as a means to reduce drought mortality of tree seedlings in early stages of reforestation projects. We investigated the amount of dew condensate produced by locally constructed dew condensers, constructed with three different infrared emitting surfaces: standard polyethylene/ TiO2 / BaSO4 foil, thermoplastic polyolefin (TPO), and plastic coated with locally available Lanco UrethanizerTM8 roofing paint. All surfaces produced similar amounts of total dew condensate, typically ranging between 0.05 and 0.25 L/m2/night. However, the materials differed in the fraction of dew running off the surfaces, which represents the water available for tree seedlings. Highest runoff fractions were obtained with painted surfaces, followed by polyethylene and polyolefin surfaces, respectively. Considerably greater amounts of nightly dew condensate were observed during the winter than in summer, attributed to differences in night length and cloud cover. A commercially available dew condenser, the Groasis WaterboxxTM, did not generate more than 0.04 L per night of runoff dew, due primarily to a small condenser surface area of < 0.2 m2. A field study showed that 1 m2 dew condensers maintained the root zone of mahogany seedlings at matric potentials > -60 kPa during dry spells. Overall, results indicated that passive dew condensers with condenser areas of 1 m2 are capable of producing sufficient water for survival of small tree seedlings during drought periods.Los condensadores de rocío se han propuesto como mecanismo para proveer agua a plántulas de árboles en etapas iniciales de reforestación. Se investigó el potencial de condensadores de fabricación local para producir agua. Se compararon condensadores construidos con tres diferentes superficies emisoras en infrarrojo: lámina estándar de polietileno impregnado con TiO2 y BaSO4, poli-olefina termoplástica (TPO), y plástico recubierto con pintura Lanco UrethanizerTM disponible en ferreterías locales. Todas las superficies produjeron cantidades similares de condensado total de rocío, por lo general entre 0.05 y 0.25 L /m2/noche. Sin embargo, los materiales variaron en la fracción del condensado escurrido desde las superficies, lo cual representa el agua disponible para las plántulas. Las fracciones de escorrentía más altas se obtuvieron con las superficies pintadas, seguido por las superficies de polietileno y de poli-olefina, respectivamente. Las cantidades de condensado durante el invierno fueron mayores que en verano, probablemente debido a noches más largas y menor nubosidad en invierno. Se evaluó el volumen de rocío (escorrentía) producido por un modelo comercial de condensador de rocío, el Groasis WaterboxxTM. Este nunca superó 0.04 L por noche, atribuido principalmente a la pequeña área de superficie (< 0.2 m2) del condensador. Un experimento de campo mostró que condensadores de rocío de 1 m2 mantuvieron el potencial matricial de agua en la zona de raíces de plántulas de caoba en valores > -60 kPa durante periodos de sequía. En general, los resultados indicaron que los condensadores de rocío con áreas superficiales de 1 m2 producen suficiente agua para la supervivencia de pequeñas plántulas de árboles

Effect of HIV-1 infection on T-Cell-based and skin test detection of tuberculosis infection

RATIONALE: Two forms of the IFN-gamma release assay (IFNGRA) to detect tuberculosis infection are available, but neither has been evaluated in comparable HIV-infected and uninfected persons in a high tuberculosis incidence environment. OBJECTIVE: To compare the ability of the T-SPOT.TB (Oxford Immunotec, Abingdon, UK), QuantiFERON-TB Gold (Cellestis, Melbourne, Australia), and Mantoux tests to identify latent tuberculosis in HIV-infected and uninfected persons. METHODS: A cross-sectional study of 160 healthy adults without active tuberculosis attending a voluntary counseling and testing center for HIV infection in Khayelitsha, a deprived urban South African community with an HIV antenatal seroprevalence of 33% and a tuberculosis incidence of 1,612 per 100,000. MEASUREMENTS AND MAIN RESULTS: One hundred and sixty (74 HIV(+) and 86 HIV(-)) persons were enrolled. A lower proportion of Mantoux results was positive in HIV-infected subjects compared with HIV-uninfected subjects (p < 0.01). By contrast, the proportion of positive IFNGRAs was not significantly different in HIV-infected persons for the T-SPOT.TB test (52 vs. 59%; p = 0.41) or the QuantiFERON-TB Gold test (43 and 46%; p = 0.89). Fair agreement between the Mantoux test (5- and 10-mm cutoffs) and the IFNGRA was seen in HIV-infected people (kappa = 0.52-0.6). By contrast, poor agreement between the Mantoux and QuantiFERON-TB Gold tests was observed in the HIV-uninfected group (kappa = 0.07-0.30, depending on the Mantoux cutoff). The pattern was similar for T-SPOT.TB (kappa = 0.18-0.24). Interpretation: IFNGRA sensitivity appears relatively unimpaired by moderately advanced HIV infection. However, agreement between the tests and with the Mantoux test varied from poor to fair. This highlights the need for prospective studies to determine which test may predict the subsequent risk of tuberculosis

Modifying three-dimensional scaffolds from novel nanocomposite materials using dissolvable porogen particles for use in liver tissue engineering.

Although hepatocytes have a remarkable regenerative power, the rapidity of acute liver failure makes liver transplantation the only definitive treatment. Attempts to incorporate engineered three-dimensional liver tissue in bioartificial liver devices or in implantable tissue constructs, to treat or bridge patients to self-recovery, were met with many challenges, amongst which is to find suitable polymeric matrices. We studied the feasibility of utilising nanocomposite polymers in three-dimensional scaffolds for hepatocytes

Altered ratio of IFN-γ/IL-10 in patients with drug resistant Mycobacterium tuberculosis and HIV-tuberculosis immune reconstitution inflammatory syndrome

We have described a clinical relationship between HIV-Tuberculosis Immune Reconstitution Inflammatory Syndrome (TB-IRIS) and anti-tubercular drug resistance. Here we studied the immune response of TB-IRIS patients from whom a drug-resistant (n = 11) or drug-susceptible (n = 25) Mycobacterium tuberculosis (MTB) strain was isolated after presenting with TB-IRIS. ELISpot analysis and multiplex cytokine analysis of the supernatant collected from peripheral blood mononuclear cells stimulated overnight with the heat-killed H37Rv MTB laboratory strain was used. Although there was no statistical difference in IFN-gamma ELISpot responses between the two groups, the results point towards higher bacterial load in the drug-resistant patients, possibly due to failed therapy. The ratio between secreted IFN-gamma/IL-10 and IL-2/IL-10 was significantly lower in TB-IRIS patients in whom the cause of TB was a drug-resistant strain compared to those with a fully sensitive strain (p = 0.02). Since host immune responses are dependent on the bacterial load, we hypothesise that the impaired cytokine balance is likely to be caused by the poorly controlled bacterial growth in these patients

"It All Ended in an Unsporting Way": Serbian Football and the Disintegration of Yugoslavia, 1989-2006

Part of a wider examination into football during the collapse of Eastern European Communism between 1989 and 1991, this article studies the interplay between Serbian football and politics during the period of Yugoslavia's demise. Research utilizing interviews with individuals directly involved in the Serbian game, in conjunction with contemporary Yugoslav media sources, indicates that football played an important proactive role in the revival of Serbian nationalism. At the same time the Yugoslav conflict, twinned with a complex transition to a market economy, had disastrous consequences for football throughout the territories of the former Yugoslavia. In the years following the hostilities the Serbian game has suffered decline, major financial hardship and continuing terrace violence, resulting in widespread nostalgia for the pre-conflict era

Bounded rationality and the Brexit negotiations:Why Britain failed to understand the EU

Research on the Brexit negotiations has linked the problems faced by Britain to flawed assumptions in the UK’s perception of EU interests. These include the idea that the EU would be open to compromise on key principles, that it would offer the UK a bespoke relationship, that national capitals would respond favourably to bilateral initiatives, and that EU unity would not hold. Yet the origins of these assumptions have been subject to little systematic scrutiny. How did such wrong-headed assumptions about the EU’s interests emerge? Drawing on insights from bounded rationality we identify three aspects of the decision-making environment linked with biased thinking: (1) ill-fitting routines and lessons, (2) a lack of decision-making openness, and (3) a lack of EU expertize and contact. We demonstrate our argument using data obtained from interviews in Brussels and London in 2017–18 and accounts of those involved in the decisions

Immunological characterisation of an unmasking TB-IRIS case

Background. Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is an early complication of combination antiretroviral therapy (cART). Two forms are recognised: (i) paradoxical – recurrent or new TB symptoms develop after cART initiation in patients receiving TB treatment prior to cART; and (ii) unmasking TB-IRIS – active TB presents within 3 months of cART in patients not receiving TB treatment at cART initiation. The latter has heightened clinical manifestations and a marked inflammatory presentation. Aim. To gain insight into the immune pathogenesis of a case of unmasking TB-IRIS. Methods. The patient was recruited when starting cART and followed up at 4, 12 and 24 weeks of treatment. Peripheral blood mononuclear cells were used for flow cytometry. Results. Immunological analysis indicated increased CD4+ T-cell proportions from 1.1% at baseline to 14% at 24 weeks (the CD4 count increased from 4 cells/µl at baseline to 41 cells/µl at 24 weeks). HIV viral load fell from 460 774 to 1 405 copies/ml during the same period. The proportion of TB antigen (PPD)-specific CD4+IFN-γ+ cells increased from 0.4% at baseline and 4 weeks (IRIS onset) to 7.8% at 12 weeks (after resolution of the IRIS episode); this fell to 0.7% at 24 weeks. The surface phenotype of CD4+IFN-γ+ cells during the episode was CD45RO+, CD45RA-, CCR7-, CD62L-, CCR5+/- and CD69-. We found a distorted balance between central memory and effector memory T-cells at cART commencement that might have predisposed the patient to unmasking TB-IRIS. We showed that this might have reflected compromised thymic output. Discussion. While it has been suggested that tuberculin-specific Th1-responses induce TB-IRIS in HIV co-infected patients, our data in this case indicated that these cells were expanded only after IRIS onset and were therefore not inducing TB-IRIS. Conclusion. We describe, in hitherto unpublished detail, the immunological characterisation of an unmasking TB-IRIS case; we show that thymic output may be compromised at IRIS onset

High prevalence of subclinical tuberculosis in HIV-1-infected persons without advanced immunodeficiency: implications for TB screening

Background The prevalence of asymptomatic tuberculosis (TB) in recently diagnosed HIV-1-infected persons attending pre-antiretroviral therapy (ART) clinics is not well described. In addition, it is unclear if the detection of Mycobacterium tuberculosis in these patients clearly represents an early asymptomatic phase leading to progressive disease or transient excretion of bacilli. Objective To describe the prevalence and outcome of subclinical TB disease in HIV-1-infected persons not eligible for ART. Methods The study was conducted in 274 asymptomatic ART-naive HIV-1-infected persons in Khayelitsha Day Hospital, Cape Town, South Africa. All participants were screened for TB using a symptom screen and spoligotyping was performed to determine genotypes. Results The prevalence of subclinical TB disease was 8.5% (95% CI 5.1% to 13.0%) (n = 18; median days to culture positivity 17 days), with 22% of patients being smear-positive. Spoligotyping showed a diverse variety of genotypes with all paired isolates being of the same spoligotype, effectively excluding cross-contamination. 56% of patients followed up developed symptoms 3 days to 2 months later. All were well and still in care 6-12 months after TB diagnosis; 60% were started on ART. A positive tuberculin skin test (OR 4.96, p = 0.064), low CD4 count (OR 0.996, p = 0.06) and number of years since HIV diagnosis (OR 1.006, p = 0.056) showed trends towards predicting TB disease. Conclusion This study found a high prevalence but good outcome (retained in care) of subclinical TB disease in HIV-1-infected persons. The results suggest that, in high HIV/TB endemic settings, a positive HIV-1 test should prompt TB screening by sputum culture irrespective of symptoms, particularly in those with a positive tuberculin skin test, longer history of HIV infection and low CD4 count. Operational difficulties in resource-constrained settings with respect to screening with TB culture highlight the need for rapid and affordable point-of-care tests to identify persons with clinical and subclinical TB disease.Immunogenetics and cellular immunology of bacterial infectious disease

Cytotoxic Mediators in Paradoxical HIV-Tuberculosis Immune Reconstitution Inflammatory Syndrome

Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) frequently complicates combined antiretroviral therapy and antituberculosis therapy in HIV-1–coinfected tuberculosis patients. The immunopathological mechanisms underlying TB-IRIS are incompletely defined, and improved understanding is required to derive new treatments and to reduce associated morbidity and mortality. We performed longitudinal and cross-sectional analyses of human PBMCs from paradoxical TB-IRIS patients and non-IRIS controls (HIV-TB–coinfected patients commencing antiretroviral therapy who did not develop TB-IRIS). Freshly isolated PBMC stimulated with heat-killed Mycobacterium tuberculosis H37Rv (hkH37Rv) were used for IFN-γ ELISPOT and RNA extraction. Stored RNA was used for microarray and RT-PCR, whereas corresponding stored culture supernatants were used for ELISA. Stored PBMC were used for perforin and granzyme B ELISPOT and flow cytometry. There were significantly increased IFN-γ responses to hkH37Rv in TB-IRIS, compared with non-IRIS PBMC (p = 0.035). Microarray analysis of hkH37Rv-stimulated PBMC indicated that perforin 1 was the most significantly upregulated gene, with granzyme B among the top five (log(2) fold difference 3.587 and 2.828, respectively), in TB-IRIS. Downstream experiments using RT-PCR, ELISA, and ELISPOT confirmed the increased expression and secretion of perforin and granzyme B. Moreover, granzyme B secretion reduced in PBMC from TB-IRIS patients during corticosteroid treatment. Invariant NKT cell (CD3(+)Vα24(+)) proportions were higher in TB-IRIS patients (p = 0.004) and were a source of perforin. Our data implicate the granule exocytosis pathway in TB-IRIS pathophysiology. Further understanding of the immunopathogenesis of this condition will facilitate development of specific diagnostic and improved therapeutic options