StrainInfo introduces electronic passports for microorganisms

Microbiology builds upon biological material deposited in biological resource centers (BRCs) as a reference framework for collaborative research. BRCs assign so-called strain numbers to label the deposited material and are responsible for long-term preservation and worldwide distribution of the material. Cultured microorganisms can be deposited into multiple BRCs and BRCs also mutually exchange their holdings. As a result, many different strain numbers can be attached to biological material that stems from the same isolate. In practice, this material is considered equivalent and used interchangeably. This implies that finding information on given biological material requires all equivalent strain numbers to be used when searching.     

Estimation of Life Cycle Material Costs of Cadmium Telluride– and Copper Indium Gallium Diselenide–Photovoltaic Absorber Materials based on Life Cycle Material Flows

Chalcogenide and chalcopyrite photovoltaic (PV) technologies are highly suitable for solar energy conversion because of their high efficiency, long‐term stable performance, and low‐cost production. However, the absorber materials that are used, such as indium, gallium, and tellurium, are regarded as critical, and their limited availability can hinder market expansion. Therefore, we assess how material efficiency measures along the PV module's life cycle can reduce the net material demand of the absorber materials and thus the material costs. In order to estimate the material flows, we developed a closed‐loop model for the life cycle representing the phases module production, module collection, module recycling, and refinement. In order to reflect the variety and uncertainty in each phase, we compose three different efficiency scenarios by varying material efficiency measures on process and product levels. For each scenario, we compute the life cycle material costs based on the computed material flows. The results show that, in the long term, the material demand can be reduced down to one fourth of the required feedstock for module manufacturing; that is, three fourths of the absorber material stays in the life cycle in a very efficient scenario. Thus, total material costs along the life cycle could be significantly reduced, because the costs for material recycling are lower than the costs for “new” technical‐grade material. This reduction in life cycle material costs means that cadmium telluride– and copper indium gallium diselenide–PV can still be financially viable even if the price of the absorber materials increases significantly. Hence those technologies will still be competitive against crystalline silicon PV in the mid to long term.     

Application of LCA as a decision-making tool for waste management systems

Aim, Scope and Background  When materials are recycled they are made available for use for several future life cycles and can therefore replace virgin material more than just once. In order to analyse the optimal waste management system for a given material, the authors have analysed the material flows in a life cycle perspective. It is important to distinguish this approach for material flow analysis for a given material from life cycle analysis of products. A product life cycle analysis analyses the product system from cradle to grave, but uses some form of allocation in order to separate the life cycle of one product from another in cases where component materials are recycled. This paper does not address allocation of burdens between different product systems, but rather focuses on methodology for decision making for waste management systems where the optimal waste management system for a given material is analysed. The focus here is the flow of the given material from cradle (raw material extraction) to grave (the material, or its inherent energy, is no longer available for use). The limitation on the number of times materials can be recycled is set by either the recycling rate, or the technical properties of the recycled material. Main Features  This article describes a mathematical geometric progression approach that can be used to expand the system boundaries and allow for recycling a given number of times. Case studies for polyethylene and paperboard are used to illustrate the importance of including these aspects when part of the Goal and Scope for the LCA study is to identify which waste management treatment options are best for a given material. The results and discussion examine the different conclusions that can be reached about which waste management option is most environmentally beneficial when the higher burdens and benefits of recycling several times are taken into account. Results  In order to assess the complete picture of the burdens and benefits arising from recycling the system boundaries must be expanded to allow for recycling many times. A mathematical geometric progression approach manages to take into account the higher burdens and benefits arising from recycling several times. If one compares different waste management systems, e.g. energy recovery with recycling, without expanding the system to include the complete effects of material recycling one can reach a different conclusion about which waste management option is preferred. Conclusions  When the purpose of the study is to compare different waste management options, it is important that the system boundaries are expanded in order to include several recycling loops where this is a physical reality. The equations given in this article can be used to include these recycling loops. The error introduced by not expanding the system boundaries can be significant. This error can be large enough to change the conclusions of a comparative study, such that material recycling followed by incineration is a much better option than waste incineration directly. Recommendations and Outlook  When comparing waste management solutions, where material recycling is a feasible option, it is important to include the relevant number of recycling loops to ensure that the benefits of material recycling are not underestimated. The methodology presented in this article should be used in future comparative studies for strategic decision-making for waste management. The approach should not be used for LCAs for product systems without due care, as this could lead to double counting of the benefits of recycling (depending on the goal and scope of the analysis). For materials where the material cycle is more of a closed loop and one cannot truly say that recycled materials replace virgin materials, a more sophisticated approach will be required, taking into account the fact that recycled materials will only replace a certain proportion of virgin materials.     

Differential effects of pre-tension on shear wave propagation in elastic media with different boundary conditions as measured by magnetic resonance elastography and finite element modeling

Magnetic resonance elastography (MRE) can non-invasively determine material stiffness based on the propagating shear wavelength. Shear wave propagation in a finite homogenous isotropic material can be affected by multiple factors. In this study we examined the effects of pre-tension and frequency on MRE shear measurements of gel phantoms with different boundary conditions, frequencies, and geometries. Results from MRE measurements were compared to wave motion theory in elastic solids and qualitatively to a finite element (FE) model. Results indicated that boundary conditions, geometry and pre-tension are important factors to be considered when performing MRE tests on a finite material, and that FE modeling can help explore how the shear wave propagation is affected under various boundary conditions and axial stresses, among other potential factors.     

Coastal connectivity and spatial subsidy from a microbial perspective

The transfer of organic material from one coastal environment to another can increase production in recipient habitats in a process known as spatial subsidy. Microorganisms drive the generation, transformation, and uptake of organic material in shallow coastal environments, but their significance in connecting coastal habitats through spatial subsidies has received limited attention. We address this by presenting a conceptual model of coastal connectivity that focuses on the flow of microbially mediated organic material in key coastal habitats. Our model suggests that it is not the difference in generation rates of organic material between coastal habitats but the amount of organic material assimilated into microbial biomass and respiration that determines the amount of material that can be exported from one coastal environment to another. Further, the flow of organic material across coastal habitats is sensitive to environmental change as this can alter microbial remineralization and respiration rates. Our model highlights microorganisms as an integral part of coastal connectivity and emphasizes the importance of including a microbial perspective in coastal connectivity studies.     

Operation and performance of an automatic metaphase finder based on the MRC fast interval processor

The Medical Research Council's fast interval processor (FIP) has been adapted for metaphase finding and selection. This article summarizes recent improvements to the hardware, and describes the selection of image features. The system uses a highly simplified but effective clustering procedure to reduce computation time, and incorporates a ranking algorithm based on computed cluster features so that high-quality metaphases can be preferentially selected. Experimental results indicate that the system can detect high-quality metaphases rapidly in "rich" material and a high proportion of the available metaphases in "sparse" material. It can handle a wide range of material with good repeatability of performance.     

Cytopress: automated slide preparation of cytologic material from suspension

This paper describes a new automated system to prepare slides of cytological material from suspension. The system collects material on a filter tape by filtration and transfers it to glass slides by means of pressure-fixation. Using cervical cells as a model, results show that a well-defined cell number is evenly deposited over a standardized area, while a small number of cells is retained on the tape and a negligible number lost in the filtrate. Contamination is very small. Application of the system to other cytological material (fine needle aspirations, monolayer and cell suspension cultures, agar cultures, and isolated nuclei) is shown. In general, more than one slide can be made from one sample. Several histological staining procedures as well as immunofluorescence labeling protocols can be applied to the preparations obtained in this way. This system thus introduces a method that will standardize specimen preparation, is quick, saves operator time, and can be used for both diagnostic and research applications.     

The nonlinear material properties of liver tissue determined from no-slip uniaxial compression experiments

The mechanical response of soft tissue is commonly characterized from unconfined uniaxial compression experiments on cylindrical samples. However, friction between the sample and the compression platens is inevitable and hard to quantify. One alternative is to adhere the sample to the platens, which leads to a known no-slip boundary condition, but the resulting nonuniform state of stress in the sample makes it difficult to determine its material parameters. This paper presents an approach to extract the nonlinear material properties of soft tissue (such as liver) directly from no-slip experiments using a set of computationally determined correction factors. We assume that liver tissue is an isotropic, incompressible hyperelastic material characterized by the exponential form of strain energy function. The proposed approach is applied to data from experiments on bovine liver tissue. Results show that the apparent material properties, i.e., those determined from no-slip experiments ignoring the no-slip conditions, can differ from the true material properties by as much as 50% for the exponential material model. The proposed correction approach allows one to determine the true material parameters directly from no-slip experiments and can be easily extended to other forms of hyperelastic material models.     

A simple,chisel-assisted mechanical microdissection system for harvesting homogenous plant tissue suitable for the analysis of nucleic acids and proteins

Many physiological processes are limited to specific tissues or even specific cell types. Analysing entire plants or organs results in averaged data of all cell types contained in the sample; thus, specific metabolic functions cannot be assigned to individual cell types. A higher spatial resolution is required. By microdissecting plant organs, homogeneous material can be obtained. If a suitable amount of material is collected, standard analytical methods can be applied to elucidate cell type-specific processes. The collection of sufficient quantities of homogeneous material can be done by means of mechanical microdissection. This technique is a low-cost alternative to laser-coupled microdissection techniques. Here we describe a protocol for chisel-assisted mechanical microdissection of embedded plant material and demonstrate that the collected material is suitable to obtain nucleic acids and proteins.     

Can the theory of critical distances predict the failure of shape memory alloys?

Components made from shape memory alloys (SMAs) such as nitinol often fail from stress concentrations and defects such as notches and cracks. It is shown here for the first time that these failures can be predicted using the theory of critical distances (TCDs), a method which has previously been used to study fracture and fatigue in other materials. The TCD uses the stress at a certain distance ahead of the notch to predict the failure of the material due to the stress concentration. The critical distance is believed to be a material property which is related to the microstructure of the material. The TCD is simply applied to a linear model of the material without the need to model the complication of its non-linear behaviour. The non-linear behaviour of the material at fracture is represented in the critical stress. The effect of notches and short cracks on the fracture of SMA NiTi was studied by analysing experimental data from the literature. Using a finite element model with elastic material behaviour, it is shown that the TCD can predict the effect of crack length and notch geometry on the critical stress and stress intensity for fracture, with prediction errors of less than 5%. The value of the critical distance obtained for this material was L?=?90?μm; this may be related to its grain size. The effects of short cracks on stress intensity were studied. It was shown that the same value of the critical distance (L?=?90?μm) could estimate the experimental data for both notches and short cracks.     

Encapsulation in a natural, preformed, multi-component and complex capsule: yeast cells

From the first observation about 40 years ago that yeast cells were interesting protective structures that could be used in several industrial applications, processes have been developed enabling technologists to incorporate several compounds possessing different physico-chemical (hydrophobic/hydrophilic) properties. Technologists screened yeast diversity to choose strains possessing the best potential and modified their physiological state to increase the uptake capability and the envelope plasticity, for instance by increasing the amount of lipids. Physico-chemical treatments were also used to improve the uptake and decrease the yeast natural material impact on the final products. For example, yeast cells could be “emptied” of their plasmic material. Yeast cells can also be coated with an additional polymeric material to increase resistance to heat treatment or decrease material liberation. These capsules can be used for several applications including carbonless paper, perfuming tissues and drug targeting, but the main industrial application deals currently with flavour encapsulation, although encapsulation in yeast is also interesting for the global food industry trend for health products. This paper proposes to review the use of yeast as an encapsulation structure focusing particularly on the properties of the yeast capsule and their impact on loading, protection, targeting and release.     

Effects of Adding Alkaline Material on the Heavy Metal Chemical Fractions in Soil under Flooded and Non-Flooded Conditions

We investigated the effect of adding an alkaline material (containing calcium carbonate and gypsum) on the immobilization of heavy metals (Cd, Cu, Pb, and Zn) in a paddy soil slightly contaminated with Cd and Zn under flooded and non-flooded conditions in the laboratory. Adding the alkaline material increased the soil pH and significantly decreased the exchangeable fraction of all of the metals, especially for Cd (>75% decrease) and Zn (ca. 90% decrease), under both flooded and non-flooded conditions. Drying the flooded soil samples increased the ratio of exchangeable fraction to the total fraction, particularly for Cd. The exchangeable fraction ratio was lower in the dried, previously flooded samples that contained the alkaline material than in the samples that did not contain the alkaline material, indicating that adding the alkaline material would be an effective way of immobilizing heavy metals during the oxidation of anoxic soils. These results show that the alkaline material can be used to immobilize heavy metals under both anoxic and oxic conditions, and that the effects of flooding and amending a paddy soil with alkaline material on the chemical forms will be different between heavy metals.     

Staining of plant Materials Cleared in NaOH

Stains are listed which have proved suitable for staining the epidermis, mesophyll, and sclerenchyma and tracheary elements, respectively, of cleared leaf material of Mouriri and Linociera. Too rapid leaching is avoided by overstaining high in the dehydration series, destaining briefly in the same solvent, and moving through to xylene. Twenty to thirty minutes staining time is generally sufficient. Concentrations and solvents can be varied widely. If destained too much, the material can usually be replaced in the dye with no ill effects. A double stain schedule (Bonnett) of five to ten minutes in 1% Bismarck brown Y in 95% alcohol followed by one to two minutes in 1% fast green FCF in 100% alcohol may be advantageous for thin-walled cells in thick material. It may be preferable to treat thinner material with tannic-acid-iron-chloride followed by safranin (Foster). The effects of bleaches and clearing compounds other than NaOH on staining have not been investigated; however, Dr. Bonnett finds that lactic acid used after NaOH improves clearing and also improves the staining of his combination (above). Mordants can doubtless be used to advantage.     

Comparison of epidermal growth factor receptor expression in lung cancer by immunohistochemical staining of both frozen and formalin fixed specimens

Two monoclonal antibodies used to investigate the expression of the epidermal growth factor receptor (EGF-R) in 45 lung cancers were compared. The R1 antibody recognises the extracellular domain portion of the receptor and the F4 is directed against the cytoplasmic portion. The reactivities of the two antibodies have been compared in fresh frozen tumour specimens. In addition the staining activity of the F4 antibody (the first to EGF-R which can be used in archival material) was compared using frozen and paraffin sections from the same series of tumours. Comparisons of the numbers of cells staining with the R1 and F4 antibody showed only slight discrepancy when fresh material was examined. The discrepancy that existed could be explained by the heterogeneity of the tumours. Very similar results were obtained using the F4 antibody on paraffin embedded and fresh non-small cell lung cancer material. We conclude that the expression EGF-R can be detected reliably by the F4 antibody in both the fresh frozen and formalin fixed, paraffin embedded material and could be useful in assessing the clinical importance of EGF-R in archival tumour material.     

Experiments testing the use of waste material in estuaries as habitat for subtidal organisms

In addition to producing extensive coastal infrastructure, urbanized estuaries are also often littered with large amounts of waste material. This can be used as habitat by fish and benthic plants and animals. Apart from studies of colonization of artificial reefs, which are usually deployed specifically to enhance populations of fish or to replace degraded habitat, there have been few studies that have specifically examined the use of waste material as habitat. Neither have previous studies compared different types of waste material that one characteristically finds in urbanized estuaries, nor the use of small patches of habitat typically created by waste. Spatial comparisons of species found on previously dumped artificial material may be confounded by the fact that different types of waste may be dumped in different places, or may be of different age. This study built small patch reefs of three different types of widespread waste material (tyres, wood or metal) and compared colonization of these over 19 months to colonization of patch reefs of similar age and size made from natural sandstone. Algal assemblages were similar among the different types of reefs, with all showing more cover and diversity on horizontal surfaces. Invertebrates similarly showed few differences among reefs, although there was greater diversity, primarily due to bryozoans, on the vertical surfaces of wooden reefs. Fish rapidly colonized and used all reefs, with cryptic species showing no differences among types of reefs. Schooling species were, however, more common on all of the waste reefs than on the natural sandstone reefs. Small patches of waste material dumped in estuaries can therefore provide useable habitat for a wide range of estuarine organisms and may form a valuable resource if natural habitats continue to be degraded or lost. Although we are not advocating that rubbish simply be discarded into estuaries with the excuse that it provides habitat, removal of existing rubbish should be considered in terms of multiple changes and disturbances to the environment.     

The use of resorbable spacers for nasal spreader grafts

The concept and technique of the use of resorbable synthetic material for nasal spreader grafts are presented. The material is felt to be particularly useful in revision rhinoplasty, in which the likelihood of internal valve collapse is high and the septum (the most common source of material for spreader grafts) often has already been harvested. The material used is a commercially available polymer of polylactic and polyglycolic acid, Lactosorb. It is supplied as a mesh sheet that can be cut to an appropriate size for spreader grafts. Although the material absorbs after approximately 12 months, it is believed that this is sufficient time for the upper lateral cartilages to be stabilized by fibrosis in their new position and to maintain the appropriate internal valve angle. This material was used on 10 patients with valvular collapse undergoing secondary rhinoplasty. In follow-up observations ranging from 12 to 18 months, there has been no recurrence of airway obstruction.     

Molecular domains of the cellulose/xyloglucan network in the cell walls of higher plants

Cellulose and xyloglucan (XG) assemble to form the cellulose/XG network, which is considered to be the dominant load-bearing structure in the growing cell walls of non-graminaceous land plants. We have extended the most commonly accepted model for the macromolecular organization of XG in this network, based on the structural and quantitative analysis of three distinct XG fractions that can be differentially extracted from the cell walls isolated from etiolated pea stems. Approximately 8% of the dry weight of these cell walls consists of XG that can be solubilized by treatment of the walls with a XG-specific endoglucanase (XEG). This material corresponds to an enzyme-susceptible XG domain, proposed to form the cross-links between cellulose microfibrils. Another 10% of the cell wall consists of XG that can be solubilized by concentrated KOH after XEG treatment. This material constitutes another XG domain, proposed to be closely associated with the surface of the cellulose microfibrils. An additional 3% of the cell wall consists of XG that can be solubilized only when the XEG- and KOH-treated cell walls are treated with cellulase. This material constitutes a third XG domain, proposed to be entrapped within or between cellulose microfibrils. Analysis of the three fractions indicates that metabolism is essentially limited to the enzyme-susceptible domain. These results support the hypothesis that enzyme-catalyzed modification of XG cross-links in the cellulose/XG network is required for the growth and development of the primary plant cell wall, and demonstrate that the structural consequences of these metabolic events can be analyzed in detail.     

A new material mapping procedure for quantitative computed tomography-based, continuum finite element analyses of the vertebra

Inaccuracies in the estimation of material properties and errors in the assignment of these properties into finite element models limit the reliability, accuracy, and precision of quantitative computed tomography (QCT)-based finite element analyses of the vertebra. In this work, a new mesh-independent, material mapping procedure was developed to improve the quality of predictions of vertebral mechanical behavior from QCT-based finite element models. In this procedure, an intermediate step, called the material block model, was introduced to determine the distribution of material properties based on bone mineral density, and these properties were then mapped onto the finite element mesh. A sensitivity study was first conducted on a calibration phantom to understand the influence of the size of the material blocks on the computed bone mineral density. It was observed that varying the material block size produced only marginal changes in the predictions of mineral density. Finite element (FE) analyses were then conducted on a square column-shaped region of the vertebra and also on the entire vertebra in order to study the effect of material block size on the FE-derived outcomes. The predicted values of stiffness for the column and the vertebra decreased with decreasing block size. When these results were compared to those of a mesh convergence analysis, it was found that the influence of element size on vertebral stiffness was less than that of the material block size. This mapping procedure allows the material properties in a finite element study to be determined based on the block size required for an accurate representation of the material field, while the size of the finite elements can be selected independently and based on the required numerical accuracy of the finite element solution. The mesh-independent, material mapping procedure developed in this study could be particularly helpful in improving the accuracy of finite element analyses of vertebroplasty and spine metastases, as these analyses typically require mesh refinement at the interfaces between distinct materials. Moreover, the mapping procedure is not specific to the vertebra and could thus be applied to many other anatomic sites.     

Modes de sélection et contraintes en Europe centrale prénéanderthalienne

The Microlithic industries of lower Palaeolithic central Europe have been speculated to be a result of raw material availability and therefore natural constraints. However, on some sites such as Bilzingsleben and Vertessz?ll?s, raw material constraints do not apply. Clearly here has been a positive selection for small-scale tools that must have different explanations. The seemingly stable pattern of forms unrelated to raw material properties, leads to the inference that early hominin societies possessed and transmitted over generations, a defined set of behavioural norms. The paper argues that patterns of choice can be isolated within lower Palaeolithic stone tool assemblages that are distinct from patterns of ecological restraint.     

Aerosol ot Solution—An Effective Softener of Herbarium Specimens for Anatomical Study

Dried plant parts are cut into convenient sizes and soaked in a solution containing 2.5-3.3% Aerosol OT in distilled water for 5 or more hours until well penetrated by the Aerosol. After brief washing in distilled water the material can be embedded, can be sectioned freehand or, if the nature of the material permits, with a sliding microtome, without embedding. Although it is a good wetting agent, Aerosol is chemically neutral; therefore, microchemical tests can be performed successfully on material treated with it. Refractory plant tissues embedded in paraffin can be successfully softened if one face of the block is trimmed to expose the tissue, then soaked in an Aerosol solution before sectioning.