751 research outputs found

    Assessment of wild plants for phytoremediation of heavy metals in soils surrounding the thermal power station

    Get PDF
    ArticleThe present investigation was carried out to evaluate the phytoextraction potential of three main wild plant species: annual nettle (Urtica urens L.), daisy fleabane (Stenactis annua (L.) Ness.) and yarrow (Achillea millefolium L.) that grow spontaneously in heavy metal contaminated areas near the thermal power station in Kakanj, Bosnia and Herzegovina. Analyses of the heavy metal content (Ni, Fe, Cr, Cu, Zn, Cd, Pb, Mn) in soil and plant samples taken from the examined area were performed using atomic absorption spectrophotometry. The results obtained revealed that the examined soils are polluted by Ni and Pb and contain relatively high value of Cr and Fe. Annual nettle, daisy fleabane and yarrow have not shown high efficiency in the absorption and accumulation of heavy metals from polluted soils, and therefore these plants are not be considered as potential phytoremediators of soils on the examined area. Furthermore, the results of the study undoubtedly confirm the fact that the total content of heavy metals in soils is not a sufficient parameter for estimating the toxicity of heavy metals in soils and consequently for their transfer and accumulation in plants

    Does sand content in spawning substrate result in early larval emergence? Evidence from a lithophilic cyprinid fish

    Get PDF
    The spawning success of lithophilic salmonids is strongly influenced by the fine sediment content (“fines”) of spawning substrates, yet knowledge on the impacts of fines on the spawning of non‐salmonid lithophiles remains limited, despite their ecological and socio‐economic importance in European rivers. Consequently, the aim here was to use an ex‐situ experiment to investigate the impact of sand content on egg survival and timing of larval emergence of the surface‐spawning cyprinid European barbel Barbus barbus. Thirty incubator boxes within a recirculating system were filled with one of five experimental sediment mixtures (0%–40% sand by mass) that each contained 300 fertilised eggs at a depth of 50 mm. Emerged, free‐swimming larvae were captured and counted daily to assess grain‐size effects on larval survival and emergence. Specifically, total proportion of emerged larvae, cumulative daily proportion of emerged larvae and time required to reach 50% emergence were measured during the study. Whilst the proportion of sand in the sediments did not have a significant impact on egg‐to‐emergence survival (mean survival per treatment 75%–79%), it significantly affected the timing of larval emergence to the water column; early emergence was detected in treatments with elevated sand content (on average, 50% emergence after 12–13 days versus 19 days in the control). Similar to findings from salmonid studies, these results suggest high sand content in spawning gravels can influence timing of larval emergence and potentially cyprinid lithophilic fish survival

    Caspase-8 controls the gut response to microbial challenges by Tnf-alpha-dependent and independent pathways

    Get PDF
    Objectives: Intestinal epithelial cells (IEC) express toll-like receptors (TLR) that facilitate microbial recognition. Stimulation of TLR ligands induces a transient increase in epithelial cell shedding, a mechanism that serves the antibacterial and antiviral host defence of the epithelium and promotes elimination of intracellular pathogens. Although activation of the extrinsic apoptosis pathway has been described during inflammatory shedding, its functional involvement is currently unclear. Design: We investigated the functional involvement of caspase-8 signalling in microbial-induced intestinal cell shedding by injecting Lipopolysaccharide (LPS) to mimic bacterial pathogens and poly(I:C) as a probe for RNA viruses in vivo. Results: TLR stimulation of IEC was associated with a rapid activation of caspase-8 and increased epithelial cell shedding. In mice with an epithelial cell-specific deletion of caspase-8 TLR stimulation caused Rip3-dependent epithelial necroptosis instead of apoptosis. Mortality and tissue damage were more severe in mice in which IECs died by necroptosis than apoptosis. Inhibition of receptor-interacting protein (Rip) kinases rescued the epithelium from TLR-induced gut damage. TLR3-induced necroptosis was directly mediated via TRIF-dependent pathways, independent of Tnf-α and type III interferons, whereas TLR4-induced tissue damage was critically dependent on Tnf-α. Conclusions: Together, our data demonstrate an essential role for caspase-8 in maintaining the gut barrier in response to mucosal pathogens by permitting inflammatory shedding and preventing necroptosis of infected cells. These data suggest that therapeutic strategies targeting the cell death machinery represent a promising new option for the treatment of inflammatory and infective enteropathies

    Self-efficacy enhanced in a cross-cultural context through an initiative in under-resourced schools in KwaZulu-Natal, South Africa

    Get PDF
    This paper discusses the Khanyisa Programme, an initiative in KwaZulu-Natal, South Africa, where learners from under-resourced schools are supported by teachers and high achievers in Grade 11 and 12 from a previously advantaged state school under apartheid. A qualitative, evaluative study was undertaken to identify key elements in the ongoing success of the programme and collect participant suggestions for improvement. The findings, discussed within the framework of self-efficacy theory, identified enormous gains by Khanyisa learners, leading to vastly improved career prospects

    Hydration in Deep Eutectic Solvents Induces Non-monotonic Changes in the Conformation and Stability of Proteins

    Get PDF
    The preservation of labile biomolecules presents a major challenge in chemistry, and deep eutectic solvents (DESs) have emerged as suitable environments for this purpose. However, how the hydration of DESs impacts the behavior of proteins is often neglected. Here, we demonstrate that the amino acid environment and secondary structure of two proteins (bovine serum albumin and lysozyme) and an antibody (immunoglobulin G) in 1:2 choline chloride:glycerol and 1:2 choline chloride:urea follow a re-entrant behavior with solvent hydration. A dome-shaped transition is observed with a folded or partially folded structure at very low (40 wt % H2O) DES hydration, while protein unfolding increases between those regimes. Hydration also affects protein conformation and stability, as demonstrated for bovine serum albumin in hydrated 1:2 choline chloride:glycerol. In the neat DES, bovine serum albumin remains partially folded and unexpectedly undergoes unfolding and oligomerization at low water content. At intermediate hydration, the protein begins to refold and gradually retrieves the native monomer–dimer equilibrium. However, ca. 36 wt % H2O is required to recover the native folding fully. The half-denaturation temperature of the protein increases with decreasing hydration, but even the dilute DESs significantly enhance the thermal stability of bovine serum albumin. Also, protein unfolding can be reversed by rehydrating the sample to the high hydration regime, also recovering protein function. This correlation provides a new perspective to understanding protein behavior in hydrated DESs, where quantifying the DES hydration becomes imperative to identifying the folding and stability of proteinsA.S.F. acknowledges the Spanish Ministerio de Universidades for the awarded Maria Zambrano fellowship. Also, the research in this study was performed with financial support from Vinnova─Swedish Governmental Agency for Innovation Systems within the NextBioForm Competence Centre and from The Crafoord Foundation (grant #20190750). The authors thank the Institute Laue-Langevin for the awarded beamtime (8-03-1049)S

    Basic Research Needs for Geosciences: Facilitating 21st Century Energy Systems

    Full text link
    Executive Summary Serious challenges must be faced in this century as the world seeks to meet global energy needs and at the same time reduce emissions of greenhouse gases to the atmosphere. Even with a growing energy supply from alternative sources, fossil carbon resources will remain in heavy use and will generate large volumes of carbon dioxide (CO2). To reduce the atmospheric impact of this fossil energy use, it is necessary to capture and sequester a substantial fraction of the produced CO2. Subsurface geologic formations offer a potential location for long-term storage of the requisite large volumes of CO2. Nuclear energy resources could also reduce use of carbon-based fuels and CO2 generation, especially if nuclear energy capacity is greatly increased. Nuclear power generation results in spent nuclear fuel and other radioactive materials that also must be sequestered underground. Hence, regardless of technology choices, there will be major increases in the demand to store materials underground in large quantities, for long times, and with increasing efficiency and safety margins. Rock formations are composed of complex natural materials and were not designed by nature as storage vaults. If new energy technologies are to be developed in a timely fashion while ensuring public safety, fundamental improvements are needed in our understanding of how these rock formations will perform as storage systems. This report describes the scientific challenges associated with geologic sequestration of large volumes of carbon dioxide for hundreds of years, and also addresses the geoscientific aspects of safely storing nuclear waste materials for thousands to hundreds of thousands of years. The fundamental crosscutting challenge is to understand the properties and processes associated with complex and heterogeneous subsurface mineral assemblages comprising porous rock formations, and the equally complex fluids that may reside within and flow through those formations. The relevant physical and chemical interactions occur on spatial scales that range from those of atoms, molecules, and mineral surfaces, up to tens of kilometers, and time scales that range from picoseconds to millennia and longer. To predict with confidence the transport and fate of either CO2 or the various components of stored nuclear materials, we need to learn to better describe fundamental atomic, molecular, and biological processes, and to translate those microscale descriptions into macroscopic properties of materials and fluids. We also need fundamental advances in the ability to simulate multiscale systems as they are perturbed during sequestration activities and for very long times afterward, and to monitor those systems in real time with increasing spatial and temporal resolution. The ultimate objective is to predict accurately the performance of the subsurface fluid-rock storage systems, and to verify enough of the predicted performance with direct observations to build confidence that the systems will meet their design targets as well as environmental protection goals. The report summarizes the results and conclusions of a Workshop on Basic Research Needs for Geosciences held in February 2007. Five panels met, resulting in four Panel Reports, three Grand Challenges, six Priority Research Directions, and three Crosscutting Research Issues. The Grand Challenges differ from the Priority Research Directions in that the former describe broader, long-term objectives while the latter are more focused

    Small cells lung epidermoid carcinoma in a HTLV1-infected patient: case report and literature review

    Get PDF
    The human T cell lymphotropic virus type 1 (HTLV-1) is the first human retrovirus discovered. Since then, it has spread worldwide and is mainly associated with adult T cell leukemia/lymphoma (ATLL) and HTLV1-associated myelopathy (HAM). Its relationship, however, with other types of cancer is controversial. We describe the case of a patient presenting with small cells lung epidermoid carcinoma who had recently developed HAM, and a review of the literature related to these conditions. This is the first case of this type of lung cancer, the same of the first description in the literature, associated with HAM outside Japan

    The role of intrinsic pathway in apoptosis activation and progression in Peyronie’s disease

    Get PDF
    Peyronie’s disease (PD) is a connective tissue disorder where formation of fibrous plaques in tunica albuginea (TA) and erectile tissue can result in penile deformity, pain, and erectile dysfunction. Fibrosis, its major pathological manifestation, arises from fibroblast proliferation and accumulation of extracellular matrix; PD progresses with formation of plaques or even ectopic calcification having the appearance of scar tissue, which prevent TA expansion during erections. The mechanisms underpinning PD are unclear, and relatively little is known about the disease itself. To date corrective surgery is the sole effective treatment. A greater understanding of PD pathophysiology at the molecular level has the potential to help develop novel medical therapeutic approaches. The aim of this study was to investigate the activation of the apoptotic intrinsic apoptotic pathway in plaques from PD patients. Tunica albuginea from either PD and control patients were assessed for the expression of bax, bcl-2, caspase 9 and 3 using immunohistochemistry, and by measurement of apoptotic cells using TUNEL assay. Bax overexpression was observed in metaplasic bone tissue, in fibroblasts and in myofibroblast of plaques from PD patients. Little or no bcl-2 immunostaining was detected in samples from either patients or controls. Caspase 3 immunostaining was very strong in fibrous tissue, in metaplasic bone osteocytes and in primary ossification center osteoblasts. Moderate caspase 9 immunostaining was seen in fibrous cells plaques and in osteocytes and osteoblasts of primary ossification centers from PD patients. Control samples were negative for caspase 9 immunostaining. In PD patients the TUNEL immunoassay showed intense immunostaining of fibroblasts and myofibroblasts, the absence of apoptotic cells in metaplasic bone tissue and on the border between fibrous and metaplasic bone tissue. Apoptotic cell death occurs in stabilized PD plaques and is partly induced by the intrinsic mitochondrial pathway. The present findings can have clinical implications and may help devise improved treatment strategies. A therapeutic approach aimed at enhancing apoptosis-inducing molecules would at least help delay the progression of PD. Identification of target molecules for gene construct or biological or chemical reagent delivery to target sites could contribute to induce PD plaque stabilization
    • 

    corecore