Changes in metal leachability through stimulation of iron reducing communities within waste sludge

Bioreduction of ferric iron-rich wastes is a rapidly emerging technology for the extraction/ recovery of metals from low-grade ores and metallurgical wastes. However, despite studies being successful, they have only been demonstrated at laboratory scale and issues relating to economic, industrial scale application have yet to be studied. Using bioreduction as a pre-treatment to increase recovery yield is a relatively new concept. This study examines the biostimulation of microbial communities to induce bioreduction of metalliferous sludge and the effect that this has on the leachability of metals from the waste using dilute sulphuric acid. Data shows an increase in both zinc and copper leachability after bioreduction, with maximum six fold and eleven fold increase (compared to pre-treatment) in the amount of zinc and copper leached respectively.</jats:p

Toxic effects of chlorinated and brominated alkanoic acids on pseudomonas-putida PP3 : selction at high-frequencies of mutations in genes encoding dehalogenases

Mutant strains of Pseudomonas putida PP3 capable of utilizing monochloroacetate (MCA) and dichloroacetate (DCA) as the sole sources of carbon and energy were isolated from chemostat cultures. The mutants differed from the parent strain in that they could grow on products of MCA and DCA dehalogenation (catalyzed by inducible dehalogenases I and II) and were resistant to growth inhibition by the two substrates. The growth inhibition of strain PP3 by MCA, DCA, and other halogenated alkanoic acids was studied. Sensitivity to dehalogenase substrates was related to the expression of the dehalogenase genes. For example, mutants producing elevated levels of one or both of the dehalogenases were sensitive to 2-monochloropropionate and 2-monochlorobutanoate at concentrations which did not affect the growth of strain PP3. P. putida PP1, the parent of strain PP3, was resistant to the inhibitory effects of MCA and DCA. Spontaneous mutants of strain PP3, also resistant to MCA and DCA, were selected at high frequency, and four different classes of these strains were distinguished on the basis of dehalogenase phenotype. All dehalogenase-producing mutants were inducible; no constitutive mutant has yet been isolated. Most of the resistant mutants examined did not produce one or both of the dehalogenase, and over half of those tested failed to revert back to the parental (strain PP3) phenotype, indicating that the observed mutations involved high-frequency deletion of DNA base sequences affecting expression of genes encoding dehalogenases and associated permease(s)

Mycobacterium avium subspecies paratuberculosis:human exposure through environmental and domestic aerosols

Mycobacterium avium subspecies paratuberculosis (Map) causes Johne’s disease in animals and is significantly associated with Crohn’s disease (CD) in humans. Our previous studies have shown Map to be present in U.K. rivers due to land deposition from chronic livestock infection and runoff driven by rainfall. The epidemiology of CD in Cardiff showed a significant association with the River Taff, in which Map can be detected on a regular basis. We have previously hypothesized that aerosols from the river might influence the epidemiology of CD. In this preliminary study, we detected Map by quantitative PCR in one of five aerosol samples collected above the River Taff. In addition, we examined domestic showers from different regions in the U.K. and detected Map in three out of 30 independent samples. In detecting Map in river aerosols and those from domestic showers, this is the first study to provide evidence that aerosols are an exposure route for Map to humans and may play a role in the epidemiology of CD

Collision-Aware Fast Simulation for Soft Robots by Optimization-Based Geometric Computing

Soft robots can safely interact with environments because of their mechanical compliance. Self-collision is also employed in the modern design of soft robots to enhance their performance during different tasks. However, developing an efficient and reliable simulator that can handle the collision response well, is still a challenging task in the research of soft robotics. This paper presents a collision-aware simulator based on geometric optimization, in which we develop a highly efficient and realistic collision checking / response model incorporating a hyperelastic material property. Both actuated deformation and collision response for soft robots are formulated as geometry-based objectives. The collision-free body of a soft robot can be obtained by minimizing the geometry-based objective function. Unlike the FEA-based physical simulation, the proposed pipeline performs a much lower computational cost. Moreover, adaptive remeshing is applied to achieve the improvement of the convergence when dealing with soft robots that have large volume variations. Experimental tests are conducted on different soft robots to verify the performance of our approach

Professionals' Views and Experiences of Using Rehabilitation Robotics With Stroke Survivors: A Mixed Methods Survey

From Frontiers via Jisc Publications RouterHistory: collection 2021, received 2021-09-20, accepted 2021-10-22, epub 2021-11-11Publication status: PublishedObjective: To understand the reason for low implementation of clinical and home-based rehabilitation robots and their potential. Design: Online questionnaire (November 2020 and February 2021). Subjects: A total of 100 professionals in stroke rehabilitation area were involved (Physiotherapists n = 62, Occupation therapists n = 35). Interventions: Not applicable. Main Measures: Descriptive statistics and thematic content analysis were used to analyze the responses: 1. Participants' details, 2. Professionals' views and experience of using clinical rehabilitation robots, 3. Professionals' expectation and concerns of using home-based rehabilitation robots. Results: Of 100 responses, 37 had experience of rehabilitation robots. Professionals reported that patients enjoyed using them and they increased accessibility, autonomy, and convenience especially when used at home. The main emergent themes were: “aims and objectives for rehabilitation robotics,” “requirements” (functional, software, and safety), “cost,” “patient factors” (contraindications, cautions, and concerns), and “staff issues” (concerns and benefits). The main benefits of rehabilitation robots were that they provided greater choice for therapy, increased the amount/intensity of treatment, and greater motivation to practice. Professionals perceived logistical issues (ease of use, transport, and storage), cost and limited adaptability to patients' needs to be significant barriers to tier use, whilst acknowledging they can reduce staff workload to a certain extent. Conclusion: The main reported benefit of rehabilitation robots were they increased the amount of therapy and practice after stroke. Ease of use and adaptability are the key requirements. High cost and staffing resources were the main barriers

Bacteria in decomposing wood and their interactions with wood-decay fungi

The fungal community within dead wood has received considerable study, but far less attention has been paid to bacteria in the same habitat. Bacteria have long been known to inhabit decomposing wood, but much remains underexplored about their identity and ecology. Bacteria within the dead wood environment must interact with wood-decay fungi, but again, very little is known about the form this takes; there are indications of both antagonistic and beneficial interactions within this fungal microbiome. Fungi are hypothesised to play an important role in shaping bacterial communities in wood, and conversely, bacteria may affect wood-decay fungi in a variety of ways. This minireview considers what is currently known about bacteria in wood and their interactions with fungi, and proposes possible associations based on examples from other habitats. It aims to identify key knowledge gaps and pressing questions for future research

An In-shoe Temperature Measurement System for Studying Diabetic Foot Ulceration Etiology: Preliminary Results with Healthy Participants

AbstractDiabetes is a major public health challenge on a global scale but our scientific understanding of diabetic foot ulceration is limited. A recent systematic review concluded that an increase in skin temperature is predictive of foot ulceration. In-shoe temperature measurement could be a useful tool for studying the etiology of diabetic foot ulceration, we present such a device and preliminary results of its use with 14 healthy participants. Our results show that temperature rise with walking mainly depends on the speed, F(2,190)=3.75, p=0.025, the effect of foot location is mild F(3,1279)=1.69, p=0.169, and there is no difference between the two feet F(1,1279)=0.937, p=0.749. We conclude that such systems are feasible but there are measurement issues to be addressed before they can be utilized further

Rheological behaviour of different composite materials for additive manufacturing of 3D bone scaffolds

The production of scaffolds for bone tissue applications is requiring a combination of physical and biological properties, which are depending on the materials morphology and pro-cessing conditions during the production process. The aim of the paper is the investigation of rheological behaviour of polymer and composite blends regularly used for the production of scaffolds for bone tissue applications with the use of additive manufacturing. Poly-ε-caprolactone (PCL), hydroxyapatite (HA), β-tri-calcium phosphate (TCP) and Bioglass 45S5 blends containing different ceramic concentrations (10 wt%, 15 wt% and 20 wt%) were prepared with the use of melt blending procedure and investigated with the use of oscillation and rotational rheology tests. Results are showing that all blends are presenting viscoelastic behaviour with higher viscous modulus, compared with elastic modulus for low frequencies, with this difference reducing while the frequency is increasing. All blends are presenting shear-thinning behaviour suitable for use with additive manufacturing methods. Viscous and elastic modulus are increasing by adding ceramic particles. Results are presenting that PCL/HA blends of the same material concentration are presenting higher elastic modulus properties compared with the other blends, while PCL/Bioglass blends are presenting lower loss factor, lower relaxation time and lower shear viscosity making them easier to handle during the printing procedure

Haloalkane-utilizing Rhodococcus strains isolated from geographically distinct locations possess a highly conserved gene cluster encoding haloalkane catabolism

The sequences of the 16S rRNA and haloalkane dehalogenase (dhaA) genes of five gram-positive haloalkane-utilizing bacteria isolated from contaminated sites in Europe, Japan, and the United States and of the archetypal haloalkane-degrading bacterium Rhodococcus sp. strain NCIMB13064 were compared. The 16S rRNA gene sequences showed less than 1% sequence divergence, and all haloalkane degraders clearly belonged to the genus Rhodococcus. All strains shared a completely conserved dhaA gene, suggesting that the dhaA genes were recently derived from a common ancestor. The genetic organization of the dhaA gene region in each of the haloalkane degraders was examined by hybridization analysis and DNA sequencing. Three different groups could be defined on the basis of the extent of the conserved dhaA segment. The minimal structure present in all strains consisted of a conserved region of 12.5 kb, which included the haloalkane-degradative gene cluster that was previously found in strain NCIMB13064. Plasmids of different sizes were found in all strains. Southern hybridization analysis with a dhaA gene probe suggested that all haloalkane degraders carry the dhaA gene region both on the chromosome and on a plasmid (70 to 100 kb). This suggests that an ancestral plasmid was transferred between these Rhodococcus strains and subsequently has undergone insertions or deletions. In addition, transposition events and/or plasmid integration may be responsible for positioning the dhaA gene region on the chromosome. The data suggest that the haloalkane dehalogenase gene regions of these gram-positive haloalkane-utilizing bacteria are composed of a single catabolic gene cluster that was recently distributed world-wide