Spontaneous activity in peripheral diaphragmatic lymphatic loops.

The spontaneous contractility of FITC-dextran-filled lymphatics at the periphery of the pleural diaphragm was documented for the first time “in vivo” in anesthetized Wistar rats. We found that lymphatic segments could be divided into four phenotypes: 1) active, displaying rhythmic spontaneous contractions (51.8% of 197 analyzed sites); 2) stretch-activated, whose contraction was triggered by passive distension of the vessel lumen (4.1%); 3) passive, which displayed a completely passive distension (4.5%); and 4) inert, whose diameter never changed over time (39.6%). Smooth muscle actin was detected by immunofluorescence and confocal microscopy in the vessel walls of active but also of inert sites, albeit with a very different structure within the vessel wall. Indeed, while in active segments, actin was arranged in a dense mesh completely surrounding the lumen, in inert segments actin decorated the vessels wall in sparse longitudinal strips. When located nearby along the same lymphatic loop, active, stretch-activated, and passive sites were always recruited in temporal sequence starting from the active contraction. The time delay was ∼0.35 s between active and stretch-activated and 0.54 s between stretch-activated and passive segments, promoting a uniform lymph flux of ∼150/200 pl/min. We conclude that, unlike more central diaphragmatic lymphatic vessels, loops located at the extreme diaphragmatic periphery do require an intrinsic pumping mechanism to propel lymph centripetally, and that such an active lymph propulsion is attained by means of a complex interplay among sites whose properties differ but are indeed able to organize lymph flux in an ordered fashion. </jats:p

Compiler fuzzing: how much does it matter?

Despite much recent interest in randomised testing (fuzzing) of compilers, the practical impact of fuzzer-found compiler bugs on real-world applications has barely been assessed. We present the first quantitative and qualitative study of the tangible impact of miscompilation bugs in a mature compiler. We follow a rigorous methodology where the bug impact over the compiled application is evaluated based on (1) whether the bug appears to trigger during compilation; (2) the extent to which generated assembly code changes syntactically due to triggering of the bug; and (3) whether such changes cause regression test suite failures, or whether we can manually find application inputs that trigger execution divergence due to such changes. The study is conducted with respect to the compilation of more than 10 million lines of C/C++ code from 309 Debian packages, using 12% of the historical and now fixed miscompilation bugs found by four state-of-the-art fuzzers in the Clang/LLVM compiler, as well as 18 bugs found by human users compiling real code or as a by-product of formal verification efforts. The results show that almost half of the fuzzer-found bugs propagate to the generated binaries for at least one package, in which case only a very small part of the binary is typically affected, yet causing two failures when running the test suites of all the impacted packages. User-reported and formal verification bugs do not exhibit a higher impact, with a lower rate of triggered bugs and one test failure. The manual analysis of a selection of the syntactic changes caused by some of our bugs (fuzzer-found and non fuzzer-found) in package assembly code, shows that either these changes have no semantic impact or that they would require very specific runtime circumstances to trigger execution divergence

Interplay between gut lymphatic vessels and microbiota

Lymphatic vessels play a distinctive role in draining fluid, molecules and even cells from interstitial and serosal spaces back to the blood circulation. Lymph vessels of the gut, and especially those located in the villi (called lacteals), not only serve this primary function, but are also responsible for the transport of lipid moieties absorbed by the intestinal mucosa and serve as a second line of defence against possible bacterial infections. Here, we briefly review the current knowledge of the general mechanisms allowing lymph drainage and propulsion and will focus on the most recent findings on the mutual relationship between lacteals and intestinal microbiota

Comprehensive longitudinal non-invasive quantification of healthspan and frailty in a large cohort (n = 546) of geriatric C57BL/6 J mice

Frailty is an age-related condition characterized by a multisystem functional decline, increased vulnerability to stressors, and adverse health outcomes. Quantifying the degree of frailty in humans and animals is a health measure useful for translational geroscience research. Two frailty measurements, namely the frailty phenotype (FP) and the clinical frailty index (CFI), have been validated in mice and are frequently applied in preclinical research. However, these two tools are based on different concepts and do not necessarily identify the same mice as frail. In particular, the FP is based on a dichotomous classification that suffers from high sample size requirements and misclassification problems. Based on the monthly longitudinal non-invasive assessment of frailty in a large cohort of mice, here we develop an alternative scoring method, which we called physical function score (PFS), proposed as a continuous variable that resumes into a unique function, the five criteria included in the FP. This score would not only reduce misclassification of frailty but it also makes the two tools, PFS and CFI, integrable to provide an overall measurement of health, named vitality score (VS) in aging mice. VS displays a higher association with mortality than PFS or CFI and correlates with biomarkers related to the accumulation of senescent cells and the epigenetic clock. This longitudinal non-invasive assessment strategy and the VS may help to overcome the different sensitivity in frailty identification, reduce the sample size in longitudinal experiments, and establish the effectiveness of therapeutic/preventive interventions for frailty or other age-related diseases in geriatric animals

Calidad inicial y daños ocurridos durante la cosecha, transporte y lavado en batatas cultivadas en el partido de San Pedro

La batata es considerada un cultivo rústico, comparada con otras hortalizas. Sin embargo, cuando hablamos de calidad, hay muchos aspectos de manejo que deben mejorar para lograr un producto sin defectos. Un estudio previo determino que tan solo el 3,11 % de las batatas procedentes de San Pedro, no poseen ningún tipo de defecto. Como parte de las actividades realizadas en la Plataforma Herramientas de Gestión de la Calidad y del proyecto Local “Batata de calidad sampedrina”, se monitoreó la calidad de las batatas producidas en el territorio. Se plantearon dos objetivos: a) determinar la calidad inicial de la batata producida en San Pedro relevando: daños por insectos, pudriciones y defectos presentes en precosecha y b) relevar los daños ocurridos durante la cosecha, y poscosecha (transporte y lavado). Las muestras de raíces, se recolectaron en cuatro momentos: Antes de cosecha, luego de cosecha, a la llegada al galpón de acondicionado y después del lavado. En la evaluación de precosecha, o calidad inicial, se analizaron las 400 batatas (100 de cada momento de muestreo) se relevaron: daños por insectos, deformaciones, heridas cicatrizadas, brotes, venas, raicillas, batatines y otros defectos, generalmente asociados a factores genéticos y otros como heridas cicatrizadas, debido a condiciones ambientales y de manejo. Los daños poscosecha (roturas, heridas abiertas, peladuras y abrasiones se relevaron sobre 100 batatas correspondientes a cada momento de muestreo. Los defectos y daños en las raíces se relevaron según lo especificado en la Resolución SAyG Nº 297/1983 y en bibliografía existente. Los resultados mostraron que todas las raíces presentaron daños por insectos, el 46 % de las batatas presentó algún grado de deformación, la presencia de venas y batatines, fue menor. Y en cuanto a heridas abiertas, en cosecha se observaron un mínimo de 18% y un máximo de 32 % de heridas abiertas, y el 70 % de las batatas analizadas luego del lavado, presentaron heridas abiertas. Se observó que no aumentan las roturas luego de la evaluación pos cosecha, por lo que aparentemente, es durante la cosecha en el que se producen la mayor parte de ellas. A modo de conclusión se pueden agrupar los problemas de calidad según tres orígenes. De origen genético: constricciones, deformaciones, surcos, venas y batatines, estaban presentes en el 63,75 % de la muestra. Así, partiendo de material seleccionado podemos disminuir estos defectos. Daños originados por insectos: El 100 % de las batatas analizadas presento daños por insectos. Combinando prácticas de manejo, se podría reducir el ataque de las principales plagas del cultivo. Los daños originados en poscosecha: las heridas sin cicatrizar acumuladas luego del lavado, representaron el 70% de las raíces, mientras que las abrasiones fueron en su mayoría en el momento de cosecha, posiblemente asociado a la “madurez” de las raíces y a las condiciones de poca humedad del suelo

Author Correction: Accurate detection of circulating tumor DNA using nanopore consensus sequencing

The Data Availability statement in the original version of the paper reads: “The sequencing datasets generated during the current study are available upon request at EGA, under accession number EGAS00001003759”. However, as this data upload was not successful, the authors reuploaded the data under a different accession number and have amended the Data Availability statement to read “The sequencing datasets generated during the current study are available upon request at EGA, under accession number EGAS00001007090”. The original article has been corrected.</p

Accurate detection of circulating tumor DNA using nanopore consensus sequencing

Levels of circulating tumor DNA (ctDNA) in liquid biopsies may serve as a sensitive biomarker for real-time, minimally-invasive tumor diagnostics and monitoring. However, detecting ctDNA is challenging, as much fewer than 5% of the cell-free DNA in the blood typically originates from the tumor. To detect lowly abundant ctDNA molecules based on somatic variants, extremely sensitive sequencing methods are required. Here, we describe a new technique, CyclomicsSeq, which is based on Oxford Nanopore sequencing of concatenated copies of a single DNA molecule. Consensus calling of the DNA copies increased the base-calling accuracy ~60×, enabling accurate detection of TP53 mutations at frequencies down to 0.02%. We demonstrate that a TP53-specific CyclomicsSeq assay can be successfully used to monitor tumor burden during treatment for head-and-neck cancer patients. CyclomicsSeq can be applied to any genomic locus and offers an accurate diagnostic liquid biopsy approach that can be implemented in clinical workflows

Towards an EPR on a Chip Spectrometer for Monitoring Radiation Damage During X ray Absorption Spectroscopy

Electron paramagnetic resonance EPR spectroscopy is an essential tool to investigate the effects of ionizing radiation, which is routinely administered for reducing contaminations and waste in food products and cosmetics as well as for sterilization in industry and medicine. In materials research, EPR methods are not only employed as a spectroscopic method of structural investigations, but also have been employed for detection of changes in electronic structure due to radiation damage from high energy X rays, for example, to monitor radical formation inside biomolecules caused by X ray irradiation at carbon, nitrogen, and oxygen K edges at synchrotron facilities. Here a compact EPR spectrometer, based on EPR on a chip EPRoC sensor and a portable electromagnet, has been developed as a solution for monitoring radiation damage of samples during their investigation by X ray absorption spectroscopy XAS at synchrotron facilities. A portable electromagnet with a soft iron core and forced air temperature stabilization was constructed as the source of the external magnetic field. The sweep range of magnetic field inside the most homogeneous region of the portable electromagnet is 12 290 mT. The compact spectrometer performance was evaluated by placing the EPRoC sensor inside either a commercial electromagnet or the portable electromagnet to record the EPR spectrum of tempol, irradiated alanine, and dilithium phthalocyanine Li2Pc . The potential performance of the portable spectrometer for the detection of radiation damage in organic compounds and transition metal containing catalysts during XAS measurements in both fluorescence and transmission modes was calculated with promising implications for measurements after implementation in a synchrotron based XAS spectromete