Survey of water supply and assessment of groundwater quality in the suburban communes of Selembao and Kimbanseke, Kinshasa in Democratic Republic of the Congo.

In many suburban municipalities of developing countries, the household drinking water comes mainly from groundwater including, wells, streams and springs. These sources are vulnerable because poor hygienic conditions and sanitation prevail causing persistence and recurrent waterborne diseases. In this research, a survey study on water resource use and an epidemiological survey of waterborne diseases were conducted among users of water points and medical institutions in suburban communes of Selembao and Kimbanseke (Kinshasa, the Democratic Republic of the Congo). In addition, physicochemical (temperature, pH, O2, electrical conductivity, and soluble ions: Na+, K+, PO4 3-, SO4 2-, NO3 -, NO2 -) and bacteriological (FIB: faecal indicator bacteria) analyses of water from 21 wells and springs were performed according to the seasonal variations. FIB included Escherichia coli (E. coli), Enterococcus and Total Coliforms. The survey results indicate that more than 75% of the patients admitted to local medical institutions between 2016 and 2019 are affected by waterborne diseases, including typhoid fever, amoebic dysentery, diarrhoea, gastroenteritis disorders and cholera. Except for NO3 - in some sites, the water physicochemical parameter values are within WHO permissible limits for drinking/domestic water quality. On the contrary, the results revealed high FIB levels in water from unmanaged wells and springs during rainy and dry seasons. The microbiological pollution was significantly higher in the rainy season compared to the dry season. Interestingly, no FIB contamination was observed in water samples from managed/developed wells. The results from this study will guide local government decisions on improving water quality to prevent recurrent waterborne diseases.

Adaptation to Photooxidative Stress: Common and Special Strategies of the Alphaproteobacteria Rhodobacter sphaeroides and Rhodobacter capsulatus.

Photosynthetic bacteria have to deal with the risk of photooxidative stress that occurs in presence of light and oxygen due to the photosensitizing activity of (bacterio-) chlorophylls. Facultative phototrophs of the genus Rhodobacter adapt the formation of photosynthetic complexes to oxygen and light conditions, but cannot completely avoid this stress if environmental conditions suddenly change. R. capsulatus has a stronger pigmentation and faster switches to phototrophic growth than R. sphaeroides. However, its photooxidative stress response has not been investigated. Here, we compare both species by transcriptomics and proteomics, revealing that proteins involved in oxidation-reduction processes, DNA, and protein damage repair play pivotal roles. These functions are likely universal to many phototrophs. Furthermore, the alternative sigma factors RpoE and RpoHII are induced in both species, even though the genetic localization of the rpoE gene, the RpoE protein itself, and probably its regulon, are different. Despite sharing the same habitats, our findings also suggest individual strategies. The crtIB-tspO operon, encoding proteins for biosynthesis of carotenoid precursors and a regulator of photosynthesis, and cbiX, encoding a putative ferrochelatase, are induced in R. capsulatus. This specific response might support adaptation by maintaining high carotenoid-to-bacteriochlorophyll ratios and preventing the accumulation of porphyrin-derived photosensitizers.

Horner Syndrome in Birds of Prey.

Horner syndrome, which results from oculosympathetic denervation, has rarely been reported in birds. A retrospective study was conducted in a raptor rehabilitation program to gain further insight into Horner syndrome in birds. Data from 5128 live raptors admitted over 20 years were reviewed. Horner syndrome was identified in 22 individuals from 13 different species. Raptors from the orders Strigiformes, Accipitriformes, and Falconiformes were affected, with the last order being underrepresented. Ptosis of the upper eyelid was the most commonly reported clinical sign in the birds diagnosed with Horner syndrome, having been noted in 21 cases. Signs of traumatic injury, such as fractures, wounds, and hematomas, were documented in 18 cases. Among the 22 cases, 12 birds were euthanatized, 3 died in treatment, and 7 were successfully released back into the wild.

A compressed sensing approach to immobilized nanoparticle localization for superparamagnetic relaxometry.

Superparamagnetic relaxometry (SPMR) exploits the unique magnetic properties of targeted superparamagnetic iron oxide nanoparticles (SPIOs) to detect small numbers of cancer cells. Reconstruction of the spatial distribution of cancer-bound nanoparticles requires solving an ill-posed inverse problem. The current method, multiple source analysis (MSA), uses a least-squares fit to determine the strength and location of a pre-determined number of magnetic dipoles. In this proof-of-concept study, we propose the application of a sparsity averaged reweighting algorithm (SARA) for volumetric reconstruction of immobilized nanoparticle distributions. We first calibrate the parameters that define the location of the sensors in the forward model of measurement physics. Using this optimized model, we evaluated the performance of the algorithms on various configurations of single and multiple point-source phantoms. We investigated the effect of the data fidelity parameter, voxel size, and iterative reweighting on the reconstruction produced by SARA. We found that the calibrated physics model can predict the detected field values within 5% of the measured data. When only a single source was present, both algorithms were able to detect as little as 0.5 µg of immobilized particles. However, when two sources were measured simultaneously, MSA failed to detect sources containing as much as 10 µg of particles, while SARA detected all of the sources containing at least 5 µg of particles. We show that a suitable data fidelity parameter can be selected objectively, and the total magnitude and location of a point source reconstructed by SARA is not sensitive to voxel size. Detection and localization of multiple small clusters of nanoparticles is a crucial step in SPMR-based diagnostic applications. Our algorithm overcomes the need to know the number of dipoles before reconstruction and improves the sensitivity of the reconstruction when multiple sources are present.

Prevalence of water-related diseases and groundwater (drinking-water) contamination in the suburban municipality of Mont Ngafula, Kinshasa (Democratic Republic of the Congo).

An epidemiological survey conducted among users of water points and medical institutions in the N'djili Kilambu neighborhood of Kinshasa in Democratic Republic of the Congo, indicates that waterborne diseases have already affected more than 60% of the patients admitted to local clinics between 2013 and 2017. In order to raise public and political awareness about this hazardous health issue resulting from the lack of safely managed sanitation systems, this study investigates the microbial quality of drinking water from local water resources. Water samples were collected from nine wells and streams used as drinking sources, and analyzed for Fecal Indicator Bacteria (FIB), including Escherichia coli, Enterococcus, and Total Coliforms. Physicochemical parameters (pH, electrical conductivity, O2, and soluble ions (Na+, K+, PO43-, SO42-, NO3-, NO2-) were also analyzed. Except for NO3- and NO2-, the average concentrations of the physicochemical parameters and dissolved ions generally meet the guidelines for drinking/domestic water quality. By contrast, the results reveal high levels of FIB in the water samples collected during both dry and wet seasons. The contamination is significantly higher during the wet season compared to dry season, due to increased runoff, open defecation practices, and more frequent overflow of onsite sanitation systems and septic tanks.

Varying kVp as a means of reducing CT breast dose to pediatric patients.

We investigated the possibility of reducing radiation dose to the breast tissue of pediatric females by using multiple tube voltages within a single CT examination. The peak kilovoltage (kVp) was adjusted when the x-ray beam was directly exposing the representative breast tissue of a 5-year-old, 10-year-old, and an adult female anthropomorphic phantom; this strategy was called kVp splitting and was emulated by using a different kVp over the anterior and posterior tube angles. Dose savings from kVp splitting were calculated relative to using a fixed kVp over all tube angles and the results indicated savings in all three phantoms when using 80 kVp over the posterior tube angles regardless of the anterior kVp. Monte Carlo (MC) simulations with and without kVp splitting were performed to estimate absorbed breast dose in voxelized models constructed from the CT images of pediatric female patients; 80 kVp was used over the posterior tube angles. The MC simulations revealed breast dose savings of between 9.8% and 33% from using kVp splitting compared to simulations using a fixed kVp protocol with the anterior technique. Before this strategy could be implemented clinically, the development of suitable image reconstruction algorithms and the image quality of scans with kVp splitting would need further study.

Application of laminates to mouthguards: finite element analysis.

A finite element model comprising a flat-ended indentor and a disc representing a colliding object and mouthguard materials, respectively, has been developed to study stress distribution and impact force in laminates. The disc consists of two layers and its top layer is in contact with the indentor. Two different combinations of layers were employed for the simulation. One had a soft layer placed on top of the rigid layer and the other was vice versa. It was found that the former had no significant difference from a monolayer in stress distribution and impact force. However, the latter was found to have a significant effect on stress distribution, and this effect could be increased by controlling ratios of modulus and volume fractions of the top and bottom layers. It was also found that the magnitude of the impact force increases with increasing effect of stress distribution, but this competition can be reduced to some degree by decreasing the volume fraction ratio of top to bottom layers.

[Peridural anesthesia with etidocaine. Clinical studies on the effect of vasoconstrictors on sensory and motor blockade]. / Periduralanaesthesie mit Etidocain. Klinische Untersuchungen zum Einfluss von Vasokonstriktoren auf die sensible und motorische Blockade.

In a randomized double-blind study etidocaine 1.5% without a vasoconstrictor (n = 10), with adrenaline 1:200,000 (n = 10) and with ornipressine 1 IU/10 ml (n = 10) were administered epidurally to 30 orthopaedic patients. Sensory blockade was tested with electric pain stimuli; motor blockade was assessed with dynamometry during isometric plantar flexion of the foot and with the Bromage score; the intraoperative analgesia was determined as well. The development of sensory and motor blockade became faster and more intensive by addition of the two vasoconstrictors. The intraoperative analgesia, insufficient without vasoconstrictors, however, not to full satisfaction. Adrenaline improved the effects of etidocaine more than did ornipressine . The sole use of etidocaine without and with vasoconstrictors is not recommended for epidural anaesthesia for surgery of the lower extremities. It is the local anaesthetic of choice for intensifying motor blockade during already achieved analgesia.