Tracer test modeling for characterizing heterogeneity and local-scale residence time distribution in an artificial recharge site

Artificial recharge of aquifers is a technique for improving water quality and increasing groundwater resources. Understanding the fate of a potential contaminant requires knowledge of the residence time distribution (RTD) of the recharged water in the aquifer beneath. A simple way to obtain the RTDs is to perform a tracer test. We performed a pulse injection tracer test in an artificial recharge system through an infiltration basin to obtain the breakthrough curves, which directly yield the RTDs. The RTDs turned out to be very broad and we used a numerical model to interpret them, to characterize heterogeneity, and to extend the model to other flow conditions. The model comprised nine layers at the site scaled to emulate the layering of aquifer deposits. Two types of hypotheses were considered: homogeneous (all flow and transport parameters identical for every layer) and heterogeneous (diverse parameters for each layer). The parameters were calibrated against the head and concentration data in both model types, which were validated quite satisfactorily against 1,1,2-Trichloroethane and electrical conductivity data collected over a long period of time with highly varying flow conditions. We found that the broad RTDs can be attributed to the complex flow structure generated under the basin due to three-dimensionality and time fluctuations (the homogeneous model produced broad RTDs) and the heterogeneity of the media (the heterogeneous model yielded much better fits). We conclude that heterogeneity must be acknowledged to properly assess mixing and broad RTDs, which are required to explain the water quality improvement of artificial recharge basins.Peer ReviewedPostprint (published version

Asteroidea de la plataforma continental de Rio Grande do Sul (Brasil), coleccionados durante los viajes del N/Oc. "Prof. W. Besnard" para el Proyecto Rio Grande do Sul

The Asteroidea collected during the cruises of the R/V "Prof. W. Besnard" along the coast of Rio Grande do Sul (Brazil) from April 1968 to January 1972 were studied. Twenty-four species are reported from the continental shelf for the area between Torres (29ºS) and Chui (34ºS). Labidiaster radiosus Lutken, Luidia clathrata (Say), Marginaster pectinatus Perrier, Mediaster trindadensis Bernasconi, Sclerasterias subangulosa (Verrill) and Tosia parva (Perrier) are new records for the area; Luidia barbadensis Perrier and L. elegans Perrier are new records for Brazil and Pectinidiscus aliciae sp. n. constitutes the first record of the genus from the Americas and is compared with the other two known species of the genus: P. annae and P. sibogae. Ecological data and the geographic distribution for each species are given. Keys for identification are provided. The general hydrology of the area and the biogeography are discussed and correlations of asteroid abundance with two commercially important fish species are made.1 - La hidrología del área estudiada, entre las latitudes 29º y 34ºS, es muy compleja y esta influenciada por aguas tropicales traídas por la Corriente de Brasil, por aguas subantarticas traídas por la Corriente de las Malvinas, por las aguas del estuario del Rio de La Plata y por la presencia cercana de la Convergencia Subtropical. 2 - Las aguas que cubren la plataforma continental del Estado de Rio Grande do Sul pueden clasificarse como Aguas Costeras de Influencia Tropical (ACIT), Aguas del Talud Continental (AT) y Aguas Costeras de Influencia Subantártica (ACISA) originadas casi exclusivamente por procesos de mezcla. 3 - En otoño e invierno es mayor la influencia de las ACISA, AT y las aguas del estuario del Rio de La Plata sobretodo en la región septentrional del área estudiada; ocurren inversiones de temperatura y predominan los procesos de mezcla sobre los de interacción océano-aire. 4 - En primavera y verano es mayor la influencia de las ACIT; predominan los procesos de interacción océano-aire sobre los de mezcla y se encuentra evidencia sugiriendo la ocurrencia de resurgencias en varios puntos. 5 - Los procesos hidrográficos del área estudiada varían estacionalmente y ademas anualmente según las condiciones meteorológicas reinantes. 6 - La fauna de Asteroidea de Rio Grande do Sul comprende cinco ordenes, nueve familias, 15 géneros y 24 especies. 7 - El área estudiada tiene una fauna de asteroideos principalmente tropical y subtropical pero incluye elementos subantárticos y antárticos. Los primeros se encuentran sobretodo al norte del paralelo de 31ºS mientras que los segundos ocurren principalmente al sur de ese paralelo. Constituye esto evidencia adicional a la hipótesis de que el área estudiada comprende dos regiones hidrográficas con su división aproximada en el paralelo 31ºS. 8 - Se reportan ocho nuevas ocurrencias: Labidiaster radiosus Lutken, Luidla clathrata (Say), Marginaster pectinatus Perrier, Mediaster trindadensis Bernasconi, Sclerasterias subangülosa (Verrill) y Tosia parva (Perrier) siendo nuevas ocurrencias para el área de estudio y Luidla barbadensis Perrier y L. elegans Perrier siendo nuevas ocurrencias para Brasil. 9 - El género Pectinidiscus Ludwig se reporta por la primera vez para las Américas y se describe una nueva especie: Pectinidiscus aliciae. Se compara con las otras dos especies conocidas del género, P. annae y P. sibogae

Hierarchical structures of anodised cold gas sprayed titanium coatings

Three different surface treatments on a Ti6Al4V alloy have been in vitro tested for possible application in cementless joint prosthesis; all of them involve the novelty of using the Cold Spray technology for their deposition: (i) an as-sprayed highly rough titanium and, followed by the deposition of a thin hydroxyapatite layer with (ii) microcrystalline or (iii) nanocrystalline structure. Primary human osteoblasts extracted from knee were seeded onto surfaces and cell viability using MTS and LIFE/DEAD assays, osteoblasts differentiation by alkaline phosphatase (ALP) quantification as well as cell morphology were tested at 1, 7 and 14 days of cell culture. Different cell morphologies between titanium and hydroxyapatite surfaces were exhibited; at 1 day of cell culture, cells on the titanium coating were spread and flattened, expanding the filopodia actin filaments in all directions, while cells on the hydroxyapatite coatings showed round like-shape morphology due to a slower attachment. Higher cell viability was detected at all times of cell culture on titanium coating due to a better attachment at 1 day. However, from 7 days of cell culture, cells on hydroxyapatite showed good attachment onto surfaces and highly increased their proliferation, mostly on nanocrystalline, achieving similar cell viability levels than titanium coatings. ALP levels were significantly higher in titanium, in part, because of greatest cell number. Overall, the best cell functional results were obtained on titanium coatings whereas microcrystalline hydroxyapatite presented the worst cellular parameters. However, results indicate that nanocrystalline hydroxyapatite coatings may achieve promising results for the faster cell proliferation once cells are attached on the surface

Detection of Trypanosoma cruzi in the saliva of diverse neotropical bats

Trypanosoma cruzi is widely reported in bats, yet transmission routes remain unclear. We present evidence from metagenomic sequence data that T. cruzi occurs in the saliva of diverse Neotropical bats. Phylogenetic analyses demonstrated that the bat‐associated T. cruzi sequences described here formed part of a bat‐specific clade, suggesting an independent transmission cycle. Our results highlight the value in repurposing metagenomic data generated for viral discovery to reveal insights into the biology of other parasites. Evaluating whether the presence of T. cruzi in the saliva of two hematophagous bat species represents an ecological route for zoonotic transmission of Chagas disease is an interesting avenue for future research

Real-time RT-PCR for Venezuelan equine encephalitis complex, Madariaga and Eastern equine encephalitis viruses: application in human and mosquito public health surveillance in Panama

Eastern equine encephalitis virus (EEEV), Madariaga virus (MADV), and Venezuelan equine encephalitis virus complex (VEEV) are New World alphaviruses transmitted by mosquitoes. They cause febrile and sometimes severe neurological disease in human and equine hosts. Detecting them during the acute phase is hindered by nonspecific symptoms and limited diagnostic tools. We designed and clinically assessed reverse transcription polymerase chain reaction assays (rRT-PCRs) for VEEV complex, MADV, and EEEV using whole-genome sequences. Validation involved 15 retrospective serum samples from 2015-2017 outbreaks, 150 mosquito pools from 2015, and 118 prospective samples from 2021-2022 surveillance in Panama. The rRT-PCRs detected VEEV complex RNA in 10 samples (66.7%) from outbreaks, with one having both VEEV complex and MADV RNAs. VEEV complex RNA was found in 5 suspected dengue cases from disease surveillance. The rRT-PCR assays identified VEEV complex RNA in 3 Culex (Melanoconion) vomerifer pools, leading to VEEV isolates in 2. Phylogenetic analysis revealed the VEEV ID subtype in positive samples. Notably, 11.9% of dengue-like disease patients showed VEEV infections. Together, our rRT-PCR validation in human and mosquito samples suggests this method can be incorporated into mosquito and human encephalitic alphavirus surveillance programs in endemic regions

Hyperspectral imaging benchmark based on machine learning for intraoperative brain tumour detection

publishedVersio

Impact of facial conformation on canine health: Brachycephalic Obstructive Airway Syndrome

The domestic dog may be the most morphologically diverse terrestrial mammalian species known to man; pedigree dogs are artificially selected for extreme aesthetics dictated by formal Breed Standards, and breed-related disorders linked to conformation are ubiquitous and diverse. Brachycephaly–foreshortening of the facial skeleton–is a discrete mutation that has been selected for in many popular dog breeds e.g. the Bulldog, Pug, and French Bulldog. A chronic, debilitating respiratory syndrome, whereby soft tissue blocks the airways, predominantly affects dogs with this conformation, and thus is labelled Brachycephalic Obstructive Airway Syndrome (BOAS). Despite the name of the syndrome, scientific evidence quantitatively linking brachycephaly with BOAS is lacking, but it could aid efforts to select for healthier conformations. Here we show, in (1) an exploratory study of 700 dogs of diverse breeds and conformations, and (2) a confirmatory study of 154 brachycephalic dogs, that BOAS risk increases sharply in a non-linear manner as relative muzzle length shortens. BOAS only occurred in dogs whose muzzles comprised less than half their cranial lengths. Thicker neck girths also increased BOAS risk in both populations: a risk factor for human sleep apnoea and not previously realised in dogs; and obesity was found to further increase BOAS risk. This study provides evidence that breeding for brachycephaly leads to an increased risk of BOAS in dogs, with risk increasing as the morphology becomes more exaggerated. As such, dog breeders and buyers should be aware of this risk when selecting dogs, and breeding organisations should actively discourage exaggeration of this high-risk conformation in breed standards and the show ring

Diversification of mammalian deltaviruses by host shifting

Hepatitis delta virus (HDV) is an unusual RNA agent that replicates using host machinery but exploits hepatitis B virus (HBV) to mobilize its spread within and between hosts. In doing so, HDV enhances the virulence of HBV. How this seemingly improbable hyperparasitic lifestyle emerged is unknown, but it underpins the likelihood that HDV and related deltaviruses may alter other host–virus interactions. Here, we show that deltaviruses diversify by transmitting between mammalian species. Among 96,695 RNA sequence datasets, deltaviruses infected bats, rodents, and an artiodactyl from the Americas but were absent from geographically overrepresented Old World representatives of each mammalian order, suggesting a relatively recent diversification within the Americas. Consistent with diversification by host shifting, both bat and rodent-infecting deltaviruses were paraphyletic, and coevolutionary modeling rejected cospeciation with mammalian hosts. In addition, a 2-y field study showed common vampire bats in Peru were infected by two divergent deltaviruses, indicating multiple introductions to a single host species. One vampire bat-associated deltavirus was detected in the saliva of up to 35% of individuals, formed phylogeographically compartmentalized clades, and infected a sympatric bat, illustrating horizontal transmission within and between species on ecological timescales. Consistent absence of HBV-like viruses in two deltavirus-infected bat species indicated acquisitions of novel viral associations during the divergence of bat and human-infecting deltaviruses. Our analyses support an American zoonotic origin of HDV and reveal prospects for future cross-species emergence of deltaviruses. Given their peculiar life history, deltavirus host shifts will have different constraints and disease outcomes compared to ordinary animal pathogens

Prolonged survival of patients with angioimmunoblastic T-cell lymphoma after high-dose chemotherapy and autologous stem cell transplantation: the GELTAMO experience

Abstract OBJECTIVES: Angioimmunoblastic T-cell lymphoma (AIL) is a rare lymphoma with a poor prognosis and no standard treatment. Here, we report our experiences with 19 patients treated with high-dose chemotherapy and autologous stem cell transplantation (HDC/ASCT) within the GELTAMO co-operative group between 1992 and 2004. METHODS: The median age at transplantation was 46 yr. Fifteen patients underwent the procedure as front-line therapy and four patients as salvage therapy. Most patients received peripheral stem cells (90%) coupled with BEAM or BEAC as conditioning regimen (79%). RESULTS: A 79% of patients achieved complete response, 5% partial response and 16% failed the procedure. After a median follow-up of 25 months, eight patients died (seven of progressive disease and secondary neoplasia), while actuarial overall survival and progression-free survival at 3 yr was 60% and 55%. Prognostic factors associated with a poor outcome included bone marrow involvement, transplantation in refractory disease state, attributing more than one factor of the age-adjusted-International Prognostic Index, Pretransplant peripheral T-cell lymphoma (PTCL) Score or Prognostic Index for PTCL. CONCLUSIONS: More than half of the patients with AIL that display unfavourable prognostic factors at diagnosis or relapse would be expected to be alive and disease-free after 3 yr when treated with HDC/ASCT. Patients who are transplanted in a refractory disease state do not benefit from this procedure