Salivary gland-specific <i>P. berghei</i> reporter lines enable rapid evaluation of tissue-specific sporozoite loads in mosquitoes

Malaria is a life-threatening human infectious disease transmitted by mosquitoes. Levels of the salivary gland sporozoites (sgs), the only mosquito stage infectious to a mammalian host, represent an important cumulative index of &lt;i&gt;Plasmodium&lt;/i&gt; development within a mosquito. However, current techniques of sgs quantification are laborious and imprecise. Here, transgenic &lt;i&gt;P. berghei&lt;/i&gt; reporter lines that produce the green fluorescent protein fused to luciferase (GFP-LUC) specifically in sgs were generated, verified and characterised. Fluorescence microscopy confirmed the sgs stage specificity of expression of the reporter gene. The luciferase activity of the reporter lines was then exploited to establish a simple and fast biochemical assay to evaluate sgs loads in whole mosquitoes. Using this assay we successfully identified differences in sgs loads in mosquitoes silenced for genes that display opposing effects on &lt;i&gt;P. berghei&lt;/i&gt; ookinete/oocyst development. It offers a new powerful tool to study infectivity of &lt;i&gt;P. berghei&lt;/i&gt; to the mosquito, including analysis of vector-parasite interactions and evaluation of transmission-blocking vaccines

TEMPERATURE AND RELATIVITY

We investigate whether inertial thermometers moving in a thermal bath behave as being hotter or colder. This question is directly related to the classical controversy concerning how temperature transforms under Lorentz transformations. Rather than basing our arguments on thermodynamical hypotheses, we perform straightforward calculations in the context of relativistic quantum field theory. For this purpose we use Unruh-DeWitt detectors, since they have been shown to be reliable thermometers in semi-classical gravity. We believe that our discussion helps in definitely clarifying this issue.Comment: 9 pages, 1 figure available upon reques

Andrological, pathologic, morphometric, and ultrasonographic findings in rams experimentally infected with Brucella ovis

AbstractBrucella ovis is considered the most important infectious cause of reproductive disorders in sheep. The disease is characterized by epididymitis, subfertility and infertility in rams. B. ovis occasionally results in abortion in ewes, as well. The aim of this study was to evaluate kinetic changes in the reproductive organs of rams experimentally infected with B. ovis. Nine rams were experimentally inoculated intrapreputially with 2mL of a suspension containing 1.2×109CFU (colony-forming units)/mL of B. ovis (strain ATCC25840). In addition, 50μL of a suspension containing 1.2×1010CFU/mL of the same B. ovis strain was inoculated into each conjunctival sac, resulting in 3.6×109CFU total per ram. Six of nine infected rams had developed clinical changes in the tail of the epididymis at 30 days post-infection (dpi), but these changes regressed in 50% of these rams. Ultrasound demonstrated an increase in the area of the tail of the epididymis (P<0.001), reduction in the area of the testes (P<0.001), and an increased length and width of the seminal vesicles (P<0.001) during the course of infection. A sperm granuloma was diagnosed on the basis of ultrasonography findings. Microscopically, there was epididymitis, testicular degeneration, and seminal vesiculitis. Inflammatory cells were detected in the semen even before the development of epididymitis. Moreover, inflammatory cells were also found in the semen of asymptomatic rams, indicating that the presence of leukocytes in the ejaculate is a valuable method for screening potential carriers of infections in the genital tract

Assessing uncertainties in estimating surface energy fluxes from remote sensing over natural grasslands in Brazil

Evapotranspiration (ET) is one of the main fluxes in the global water cycle. As the Brazilian Pampa biome carries a rich biodiversity, accurate information on the ET dynamics is essential to support its proper monitoring and establish conservation strategies. In this context, we assessed an operational methodology based on the Simplified Surface Energy Balance Index (S-SEBI) model to estimate energy fluxes over the natural grasslands of the Pampa between 2014 and 2019. The S-SEBI is an ET model that requires a minimum of meteorological inputs and has demonstrated reasonable accuracy worldwide. Therefore, we investigated the model performance considering radiation data from both ERA5 reanalysis and Eddy Covariance measurements from a flux tower. Furthermore, comparisons from satellite-based estimates with in situ measurements were performed with and without energy balance closure (EBC). Results indicated that the meteorological inputs have low sensitivity on daily ET estimates from the S-SEBI model. In contrast, the instantaneous energy balance components are more affected. The strong seasonality impacts the evaporative fraction, which is more evident in late summer and autumn and may compromise the performance of the model in the biome. The effects in the daily ET are lower when in situ data without EBC are considered as ground truth. However, they are less correlated with the remote sensing-based estimates. These insights are useful to monitor water and energy fluxes from local to regional scale and provide the opportunity to capture ET trends over the natural grasslands of the Pampa

An Improved Description of the Dielectric Breakdown in Oxides Based on a Generalized Weibull distribution

In this work, we address modal parameter fluctuations in statistical distributions describing charge-to-breakdown $(Q_{BD})$ and/or time-to-breakdown $(t_{BD})$ during the dielectric breakdown regime of ultra-thin oxides, which are of high interest for the advancement of electronic technology. We reobtain a generalized Weibull distribution ($q$-Weibull), which properly describes $(t_{BD})$ data when oxide thickness fluctuations are present, in order to improve reliability assessment of ultra-thin oxides by time-to-breakdown $(t_{BD})$ extrapolation and area scaling. The incorporation of fluctuations allows a physical interpretation of the $q$-Weibull distribution in connection with the Tsallis statistics. In support to our results, we analyze $t_{BD}$ data of SiO$_2$-based MOS devices obtained experimentally and theoretically through a percolation model, demonstrating an advantageous description of the dielectric breakdown by the $q$-Weibull distribution.Comment: 5 pages, 3 figure

Large phenotype jumps in biomolecular evolution

By defining the phenotype of a biopolymer by its active three-dimensional shape, and its genotype by its primary sequence, we propose a model that predicts and characterizes the statistical distribution of a population of biopolymers with a specific phenotype, that originated from a given genotypic sequence by a single mutational event. Depending on the ratio g0 that characterizes the spread of potential energies of the mutated population with respect to temperature, three different statistical regimes have been identified. We suggest that biopolymers found in nature are in a critical regime with g0 in the range 1-6, corresponding to a broad, but not too broad, phenotypic distribution resembling a truncated Levy flight. Thus the biopolymer phenotype can be considerably modified in just a few mutations. The proposed model is in good agreement with the experimental distribution of activities determined for a population of single mutants of a group I ribozyme.Comment: to appear in Phys. Rev. E; 7 pages, 6 figures; longer discussion in VII, new fig.