A remote sensing-based three-source energy balance model to improve global estimations of evapotranspiration in semi-arid tree-grass ecosystems.

It is well documented that energy balance and other remote sensing-based evapotranspiration (ET) models face greater uncertainty over water-limited tree-grass ecosystems (TGEs), representing nearly 1/6th of the global land surface. Their dual vegetation strata, the grass-dominated understory and tree-dominated overstory, make for distinct structural, physiological and phenological characteristics, which challenge models compared to more homogeneous and energy-limited ecosystems. Along with this, the contribution of grasses and trees to total transpiration (T), along with their different climatic drivers, is still largely unknown nor quantified in TGEs. This study proposes a thermal-based three-source energy balance (3SEB) model, accommodating an additional vegetation source within the well-known two-source energy balance (TSEB) model. The model was implemented at both tower and continental scales using eddy-covariance (EC) TGE sites, with variable tree canopy cover and rainfall (P) regimes and Meteosat Second Generation (MSG) images. 3SEB robustly simulated latent heat (LE) and related energy fluxes in all sites (Tower: LE RMSD ~60 W/m2 ; MSG: LE RMSD ~90 W/m2 ), improving over both TSEB and seasonally changing TSEB (TSEB-2S) models. In addition, 3SEB inherently partitions water fluxes between the tree, grass and soil sources. The modelled T correlated well with EC T estimates (r > .76), derived from a machine learning ET partitioning method. The T/ET was found positively related to both P and leaf area index, especially compared to the decomposed grass understory T/ET. However, trees and grasses had contrasting relations with respect to monthly P. These results demonstrate the importance in decomposing total ET into the different vegetation sources, as they have distinct climatic drivers, and hence, different relations to seasonal water availability. These promising results improved ET and energy flux estimations over complex TGEs, which may contribute to enhance global drought monitoring and understanding, and their responses to climate change feedbacks.

A Potential New Threat to Wild Life: Presence of UV Filters in Bird Eggs from a Preserved Area.

The present study uses bird eggs of seven wild species as a biomonitoring tool for sunscreens occurrence. Seven UV filters (UV-Fs), including 3 hydroxy-metabolites of oxybenzone (benzophenone 3, BP3) were characterized in unhatched eggs from Doñana Natural Space (Spain). High frequency of detection was observed for all UV-Fs, ranging from 95% to 100%. The oxybenzone metabolite 4-hydroxybenzophenone (4HB) was ubiquitous at concentrations in the range 12.0-3348 ng g-1 dry weight (dw). The parent compound, oxybenzone, was also present in all samples at lower concentrations (16.9-49.3 ng g-1 dw). Due to the three BP3's metabolites, benzophenone 1 (BP1), 4HB, and 4,4'-dihydroxybenzophenone (4DHB) presence in unhatched eggs, it can be inferred that parent compounds are absorbed into the bird through the upper gut and the OH-derivatives formed are transferred by the mother to the egg before the lying. White stork (Ciconia ciconia) and western marsh harrier (Circus aeruginosus) were the most contaminated species, with mean total UV-Fs concentrations of 834 and 985 ng g-1 dw, respectively. Results evidenced that biomagnification process across the bird species studied cannot be ruled out.

Comparison of the 2-step tuberculin skin test and the quantiFERON-TB Gold In-Tube Test for the screening of tuberculosis infection before liver transplantation.

The ability of interferon-gamma release assays (IGRAs) to detect latent tuberculosis (TB) infection before liver transplantation (LT)is not well established. The aims of this study were (1) to compare the ability of the tuberculin skin test (TST) and the QuantiFERON-TB Gold In-Tube (QFT-IT) test (a whole-blood IGRA) to diagnose latent TB infections in patients awaiting LT and (2) to correlate the results with the severity of liver disease. We conducted a prospective, cross-sectional study of patients who were evaluated for LT between July 2008 and July 2010. The 95 patients who were included underwent the 2-step TST and the QFT-IT test. The mean Model for End-Stage Liver Disease (MELD) score was 13.8. Forty-four patients (46.3%) had positive TST results, 42 (44.2%) had positive QFT-IT results, and 2 (2.1%) had indeterminate QFT-IT results. Simultaneous TST and QFT-IT testing yielded a positivity rate of 55.8% [95% confidence interval (CI) = 45.3-65.9] with either test, and the 2-step TST yielded a positivity rate of 46.3% (95% CI = 36.1-56.8); the difference was 9.5% (P = 0.004). In an adjusted analysis, the rates for positive TST results were lower in patients with MELD scores > or = 18 [odds ratio (OR) = 0.2, 95% CI = 0.04-0.7], lower in Child-Pugh-Turcotte (CPT) class C patients versus CPT class A patients (OR = 0.1, 95% CI = 0.02-0.6), and higher in males (OR = 6.4, 95% CI = 1.9-22.0). In contrast, only being male (OR = 3.5, 95% CI = 1.1-11.0) was associated with positive QFT-IT results; no association was found with the MELD score (OR = 0.8, 95% CI = 0.2-2.8) or the CPT class (OR = 0.3; 0.05-1.4). In conclusion, the QFT-IT test is better than the TST for detecting latent TB infection in patients with more advanced liver disease. Our results support the regular use of the QFT-IT test for screening patients with end-stage liver disease for latent TB infection before LT.

Pyrethroid insecticides in wild bird eggs from a World Heritage Listed Park: A case study in Doñana National Park (Spain).

Recent studies demonstrated that the common pyrethroid insecticides are present in aquatic biota tissues. In this study, 123 samples of unhatched eggs of 16 wild bird species collected from 2010 to 2012 in Doñana National and Natural Park were analysed to determine 13 pyrethroids. This study represents the first time that pyrethroids are detected in tissues of terrestrial biota, 93% of these samples being positive to those pollutants. Levels of total pyrethroids ranged from not detected to 324 ng g-1 lw. The samples were characterized by stable isotope analysis. Species with diets based on anthropogenic food showed higher levels of pyrethroids and lower values of δ15N. Finally, we characterized the isomers of pyrethroids and discerned some isomeric- and enantiomeric-specific accumulations. In particular, tetramethrin and cyhalothrin showed an enantiomeric-selective accumulation of one enantiomer, highlighting the need to assess toxicological effects of each enantiomer separately to be able to make a correct risk assessment of pyrethroids in birds.

Human-mediated secondary contact of two tortoise lineages results in sex-biased introgression.

Human-mediated secondary contact of recently diverged taxa offers valuable opportunities for studying the evolutionary mechanisms involved in the establishment and maintenance of genetic boundaries between taxa. We used mitochondrial and microsatellite markers to examine a recently introduced population of the spur-thighed tortoise (Testudo graeca) of mixed origin in the Doñana National Park (SW Spain). The earliest records of tortoises in Doñana trace back to the 18th century, but several population reinforcements in the 20th century with animals from Morocco are well-documented. Consequently, different genetic lineages, which represent distinct subspecies, are thought to co-exist there. Our results confirmed the presence of distinct lineages by revealing that tortoises of the subspecies T. g. marokkensis were introduced into a local allochthonous T. g. graeca population. Unexpectedly, T. g. marokkensis haplotypes exclusively appeared in males, and admixture levels were statistically sex-biased toward males. The sex ratio of the population deviated from parity, with males being 2.36-fold more abundant than females. Our results indicated that population reinforcements had a strong effect on the genetic composition of this population and aggravated its sex ratio deviation. We predict that this sex-biased pattern of introgression is ephemeral and advocated to the near loss of T. g. marokkensis haplotypes.

Detection of latent tuberculosis by the tuberculin skin test and a whole-blood interferon-γ release assay, and the development of active tuberculosis in HIV-seropositive persons.

This study evaluated the QuantiFERON-TB Gold In-Tube (QFT-GIT; Cellestis, Carnegie, Australia) test and the tuberculin skin test (TST) for the detection of latent tuberculosis infection (LTBI) in HIV-infected adults. One hundred thirty-five HIV-seropositive persons and 135 controls underwent TST and QFT-GIT. HIV-infected patients who gave a positive result on either test were offered chemoprophylaxis. The prevalence of LTBI was 6.7% by TST and 9.6% by QFT-GIT (P = 0.3) in HIV-seropositive subjects, and 34.8% by TST and 21.5% by QFT-GIT (P = 0.02) among controls. TST reactivity declined sharply as CD4(+) cells fell (15.8%, 10.3%, and 0% for >500, 301-500 and ≤300 CD4(+) cells/mm(3), respectively; P = 0.002). A less pronounced fall occurred with QFT-GIT (15.8%, 13.8%, and 0% for >500, 301-500, and <100 CD4(+) cells/mm(3), respectively; P = 0.03). No cases of tuberculosis occurred during follow-up (0.26 per 100 person-years). Simultaneous testing with TST and QFT-GIT for targeting of chemoprophylaxis, early in the course of HIV infection, might minimize the risk of tuberculosis in these patients.

Diagnosis of tuberculosis infection by tuberculin skin test and a whole-blood interferon-γ release assay in patients considered for anti-tumor necrosis factor-α therapy.

To assess the performance of QuantiFERON®-TB Gold in-Tube (QFT-GIT; Cellestis, Carnegie, Australia) and tuberculin skin test (TST) in patients with immune-mediated inflammatory diseases (IMID), before anti-tumor necrosis factor-α (TNF-α) therapy, and to compare the results with those from the healthy population. Three hundred fourteen subjects (214 with IMID and 100 controls) underwent simultaneous QFT-GIT and TST. QFT-GIT was positive in 21% of IMID patients and in 16% of controls (P = 0.29). Among IMID patients, 21% tested positive by QFT-GIT and 24%, by TST (P = 0.30). Positive QFT-GIT results were not affected by immunosuppressive therapy (odds ratio, 0.78; 95% confidence interval [CI], 0.36-1.68; P = 0.52). Agreement between both tests in those patients who tested positive by one of the tests was 50% (95% CI, 37.2-62.8). QFT-GIT is useful for identifying IMID patients requiring treatment of latent tuberculosis before anti-TNF therapy. However, given the poor agreement between TST and QFT-GIT, we advocate a strategy of simultaneous testing to optimize diagnostic sensitivity.