Electroporation for water disinfection: a proof of concept experimentation

This paper is a proof of concept showing the effectiveness of using irreversible electroporation (IRE) as a stage of water disinfection in the water treatment process. The IRE process essentially requires relatively high voltage pulses to pose a pulsed electric field across harmful microorganisms. In this paper, a laboratory-based solid-state Marx generator was built for this purpose and untreated water samples have been used to test the effectiveness of applying variable pulse width, magnitude and rate. All the pulses are unipolar rectangular. The tested samples are all from the same water source with the same coliform count. After performing the electroporation disinfection process the coliform count reached zero proving the effectiveness of IRE

Invasion by P. falciparum Merozoites Suggests a Hierarchy of Molecular Interactions

Central to the pathology of malaria disease are the repeated cycles of parasite invasion and destruction of human erythrocytes. In Plasmodium falciparum, the most virulent species causing malaria, erythrocyte invasion involves several specific receptor–ligand interactions that direct the pathway used to invade the host cell, with parasites varying in their dependency on these different pathways. Gene disruption of a key invasion ligand in the 3D7 parasite strain, the P. falciparum reticulocyte binding-like homolog 2b (PfRh2b), resulted in the parasite invading via a novel pathway. Here, we show results that suggest the molecular basis for this novel pathway is not due to a molecular switch but is instead mediated by the redeployment of machinery already present in the parent parasite but masked by the dominant role of PfRh2b. This would suggest that interactions directing invasion are organized hierarchically, where silencing of dominant invasion ligands reveal underlying alternative pathways. This provides wild parasites with the ability to adapt to immune-mediated selection or polymorphism in erythrocyte receptors and has implications for the use of invasion-related molecules in candidate vaccines

UAS-based high resolution mapping of evapotranspiration in a Mediterranean tree-grass ecosystem

Este artículo está sujeto a una licencia CC BY 4.0Understanding the impact of land use and land cover change on surface energy and water budgets is increasingly important in the context of climate change research. Eddy covariance (EC) methods are the gold standard for high temporal resolution measurements of water and energy fluxes, but cannot resolve spatial heterogeneity and are limited in scope to the tower footprint (few hundred meter range). Satellite remote sensing methods have excellent coverage, but lack spatial and temporal resolution. Long-range unmanned aerial systems (UAS) can complement these other methods with high spatial resolution over larger areas. Here we use UAS thermography and multispectral data as inputs to two variants of the Two Source Energy Balance Model to accurately map surface energy and water fluxes over a nutrient manipulation experiment in a managed semi-natural oak savanna from peak growing season to senescence. We use energy flux measurements from 6 EC stations to evaluate the performance of our method and achieve good accuracy (RMSD ≈ 60 W m− 2 for latent heat flux). We use the best performing latent heat estimates to produce very high-resolution evapotranspiration (ET) maps, and investigate the drivers of ET change over the transition to the senescence period. We find that nitrogen and nitrogen plus phosphorus treatments lead to significant increases in ET (P < 0.001) for both trees (4 and 6%, respectively) and grass (12 and 9%, respectively) compared to the control. These results highlight that the high sensitivity and spatial and temporal resolution of a UAS system allows the precise estimation of relative water and energy fluxes over heterogeneous vegetation cover.This research was supported by the DAAD/BMBF program Make Our Planet Great Again – German Research Initiative Project MONSOON (grant number 57429870).Peer reviewe

Penetrating spinal injury with wooden fragments causing cauda equina syndrome: case report and literature review

Study design: Case report Objective: To report an unusual case of cauda equina syndrome following penetrating injury to the lumbar spine by wooden fragments and to stress the importance of early magnetic resonance imaging (MRI) in similar cases. Summary of background data: A 22-year-old girl accidentally landed on wooden bannister and sustained a laceration to her back. She complained of back pain but had fully intact neurological function. The laceration in her back was explored and four large wooden pieces were removed. However 72 h later, she developed cauda equina syndrome. MRI demonstrated the presence of a foreign body between second and third lumbar spinal levels following which she underwent emergency decompressive laminectomy and the removal of the multiple wooden fragments that had penetrated the dura. Results: Post-operatively motor function in her lower limbs returned to normal but she continued to require a catheter for incontinence. At review 6 months later, she was mobilising independently but the incontinence remained unchanged. Conclusion: There are no reported cases in the literature of wooden fragments penetrating the dura from the back with or without the progression to cauda equina syndrome. The need for a high degree of suspicion and an early MRI scan to localise any embedded wooden fragments that may be separate from the site of laceration is emphasized even if initial neurology is intact

Highly selective and solvent-dependent reduction of Nitrobenzene to N-phenylhydroxylamine, azoxybenzene, and aniline catalyzed by phosphino-modified polymer immobilized ionic liquid-stabilized AuNPs

Gold nanoparticles stabilized by phosphine-decorated polymer immobilized ionic liquids (AuNP@PPh2-PIILP) is an extremely efficient multiproduct selective catalyst for the sodium borohydride-mediated reduction of nitrobenzene giving N-phenylhydroxylamine, azoxybenzene, or aniline as the sole product under mild conditions and a very low catalyst loading. The use of a single nanoparticle-based catalyst for the partial and complete reduction of nitroarenes to afford three different products with exceptionally high selectivities is unprecedented. Under optimum conditions, thermodynamically unfavorable N-phenylhydroxylamine can be obtained as the sole product in near quantitative yield in water, whereas a change in reaction solvent to ethanol results in a dramatic switch in selectivity to afford azoxybenzene. The key to obtaining such a high selectivity for N-phenylhydroxylamine is the use of a nitrogen atmosphere at room temperature as reactions conducted under an inert atmosphere occur via the direct pathway and are essentially irreversible, while reactions in air afford significant amounts of azoxy-based products by virtue of competing condensation due to reversible formation of N-phenylhydroxylamine. Ultimately, aniline can also be obtained quantitatively and selectively by adjusting the reaction temperature and time accordingly. Introduction of PEG onto the polyionic liquid resulted in a dramatic improvement in catalyst efficiency such that N-phenylhydroxylamine could be obtained with a turnover number (TON) of 100 000 (turnover frequency (TOF) of 73 000 h–1, with >99% selectivity), azoxybenzene with a TON of 55 000 (TOF of 37 000 h–1 with 100% selectivity), and aniline with a TON of 500 000 (TOF of 62 500 h–1, with 100% selectivity). As the combination of ionic liquid and phosphine is required to achieve high activity and selectivity, further studies are currently underway to explore whether interfacial electronic effects influence adsorption and thereby selectivity and whether channeling of the substrate by the electrostatic potential around the AuNPs is responsible for the high activity. This is the first report of a AuNP-based system that can selectively reduce nitroarenes to either of two synthetically important intermediates as well as aniline and, in this regard, is an exciting discovery that will form the basis to develop a continuous flow process enabling facile scale-up

Lunar Mining: Designing a Robust Robotic Mining System

The annual NASA Robotic Mining Challenge: Lunabotics tasks teams with building robots capable of traversing and mining simulated Lunar terrain. The competition goal is to utilize automation and sensing alongside mechanical systems to harvest icy regolith (gravel) from beneath the satellite’s surface. This year, Utah Student Robotics sought to improve upon the design from last year. The 2019-2020 rover is based on proven NASA concepts, such as the RASSOR 2.0 digging drum, and the Rocker-Bogie mobility platform

A global model of the response of tropical and sub-tropical forest biodiversity to anthropogenic pressures

Habitat loss and degradation, driven largely by agricultural expansion and intensification, present the greatest immediate threat to biodiversity. Tropical forests harbour among the highest levels of terrestrial species diversity and are likely to experience rapid land-use change in the coming decades. Synthetic analyses of observed responses of species are useful for quantifying how land use affects biodiversity and for predicting outcomes under land-use scenarios. Previous applications of this approach have typically focused on individual taxonomic groups, analysing the average response of the whole community to changes in land use. Here, we incorporate quantitative remotely sensed data about habitats in, to our knowledge, the first worldwide synthetic analysis of how individual species in four major taxonomic groups—invertebrates, ‘herptiles’ (reptiles and amphibians), mammals and birds—respond to multiple human pressures in tropical and sub-tropical forests. We show significant independent impacts of land use, human vegetation offtake, forest cover and human population density on both occurrence and abundance of species, highlighting the value of analysing multiple explanatory variables simultaneously. Responses differ among the four groups considered, and—within birds and mammals—between habitat specialists and habitat generalists and between narrow-ranged and wide-ranged species

Obesity dysregulates the pulmonary antiviral immune response

Obesity is a well-recognized risk factor for severe influenza infections but the mechanisms underlying susceptibility are poorly understood. Here, we identify that obese individuals have deficient pulmonary antiviral immune responses in bronchoalveolar lavage cells but not in bronchial epithelial cells or peripheral blood dendritic cells. We show that the obese human airway metabolome is perturbed with associated increases in the airway concentrations of the adipokine leptin which correlated negatively with the magnitude of ex vivo antiviral responses. Exogenous pulmonary leptin administration in mice directly impaired antiviral type I interferon responses in vivo and ex vivo in cultured airway macrophages. Obese individuals hospitalised with influenza showed dysregulated upper airway immune responses. These studies provide insight into mechanisms driving propensity to severe influenza infections in obesity and raise the potential for development of leptin manipulation or interferon administration as novel strategies for conferring protection from severe infections in obese higher risk individuals