Effect of Wood Particle Size on Fungal Growth in a Model Biomechanical Pulping Process

The pretreatment of aspen wood chips with white-rot fungus has been evaluated as a way of making biomechanical pulp. Our study addressed (1) whether wood particle size (chip size) affects the growth pattern of the attacking organism, and (2) whether the difference in particle size between chips and coarse pulp is related to the availability of wood polymers to the fungus. We qualitatively evaluated the growth of Phanerochaete chrysosporium BKM-F-1767 on aspen wood using standard industrial 6- and 19-mm chips and coarse refiner mechanical pulp. Scanning electron microscopy revealed a slight increase in the number of hyphae in the 19-mm chips compared to that in the 6-mm chips, but no major morphological differences in cellulose or lignin loss. Dense aerial hyphal growth occurred around the chips, but not around the coarse pulp. The fungus appeared to attack the coarse pulp from both outside and within the fiber wall. Hyphae within both the middle lamella and the cell lumina attacked the cell walls. The fungus eroded the chip cell walls and their constituents primarily from the wood cell lumen outward. After only 3 weeks of fungal treatment, both chips and coarse pulp showed marked localized cell-wall thinning and fragmentation as well as generalized swelling and relaxing of the normally rigid cell-wall structure. We conclude that particle size has only a minor effect on fungal growth on wood under conditions such as those likely to be used in a commercial biopulping process

Hypo‐collagenesis in photoaged skin predicts response to anti‐aging cosmeceuticals

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98115/1/jocd12037.pd

Initiation context modulates autoregulation of eukaryotic translation initiation factor 1 (eIF1)

The central feature of standard eukaryotic translation initiation is small ribosome subunit loading at the 5′ cap followed by its 5′ to 3′ scanning for a start codon. The preferred start is an AUG codon in an optimal context. Elaborate cellular machinery exists to ensure the fidelity of start codon selection. Eukaryotic initiation factor 1 (eIF1) plays a central role in this process. Here we show that the translation of eIF1 homologs in eukaryotes from diverse taxa involves initiation from an AUG codon in a poor context. Using human eIF1 as a model, we show that this poor context is necessary for an autoregulatory negative feedback loop in which a high level of eIF1 inhibits its own translation, establishing that variability in the stringency of start codon selection is used for gene regulation in eukaryotes. We show that the stringency of start codon selection (preferential utilization of optimal start sites) is increased to a surprising degree by overexpressing eIF1. The capacity for the cellular level of eIF1 to impact initiation through the variable stringency of initiation codon selection likely has significant consequences for the proteome in eukaryotes

Increasing the Power to Detect Causal Associations by Combining Genotypic and Expression Data in Segregating Populations

To dissect common human diseases such as obesity and diabetes, a systematic approach is needed to study how genes interact with one another, and with genetic and environmental factors, to determine clinical end points or disease phenotypes. Bayesian networks provide a convenient framework for extracting relationships from noisy data and are frequently applied to large-scale data to derive causal relationships among variables of interest. Given the complexity of molecular networks underlying common human disease traits, and the fact that biological networks can change depending on environmental conditions and genetic factors, large datasets, generally involving multiple perturbations (experiments), are required to reconstruct and reliably extract information from these networks. With limited resources, the balance of coverage of multiple perturbations and multiple subjects in a single perturbation needs to be considered in the experimental design. Increasing the number of experiments, or the number of subjects in an experiment, is an expensive and time-consuming way to improve network reconstruction. Integrating multiple types of data from existing subjects might be more efficient. For example, it has recently been demonstrated that combining genotypic and gene expression data in a segregating population leads to improved network reconstruction, which in turn may lead to better predictions of the effects of experimental perturbations on any given gene. Here we simulate data based on networks reconstructed from biological data collected in a segregating mouse population and quantify the improvement in network reconstruction achieved using genotypic and gene expression data, compared with reconstruction using gene expression data alone. We demonstrate that networks reconstructed using the combined genotypic and gene expression data achieve a level of reconstruction accuracy that exceeds networks reconstructed from expression data alone, and that fewer subjects may be required to achieve this superior reconstruction accuracy. We conclude that this integrative genomics approach to reconstructing networks not only leads to more predictive network models, but also may save time and money by decreasing the amount of data that must be generated under any given condition of interest to construct predictive network models

Modeling Early Stage Bone Regeneration With Biomimetic Electrospun Fibrinogen Nanofibers and Adipose-Derived Mesenchymal Stem Cells

The key events of the earliest stages of bone regeneration have been described in vivo although not yet modeled in an in vitro environment, where mechanistic cell-matrix-growth factor interactions can be more effectively studied. Here, we explore an early-stage bone regeneration model where the ability of electrospun fibrinogen (Fg) nanofibers to regulate osteoblastogenesis between distinct mesenchymal stem cells populations is assessed. Electrospun scaffolds of Fg, polydioxanone (PDO), and a Fg:PDO blend were seeded with adipose-derived mesenchymal stem cells (ASCs) and grown for 7-21 days in osteogenic differentiation media or control growth media. Scaffolds were analyzed weekly for histologic and molecular evidence of osteoblastogenesis. In response to osteogenic differentiation media, ASCs seeded on the Fg scaffolds exhibit elevated expression of multiple genes associated with osteoblastogenesis. Histologic stains and scanning electron microscopy demonstrate widespread mineralization within the scaffolds, as well as de novo type I collagen synthesis. Our data demonstrates that electrospun Fg nanofibers support ASC osteogenic differentiation, yet the scaffold itself does not appear to be osteoinductive. Together, ASCs and Fg recapitulate early stages of bone regeneration ex vivo and presents a prospective autologous therapeutic approach for bone repair

A Method for Measuring Planar Residual Stresses in Rectangularly Orthotropic Materials

A semidestructive method has been developed for determining the principal residual stresses and directions in rectangularly orthotropic materials. The reduction equations are based upon a set of functions that describe the surface strain-relaxation field about a hole drilled to a limited depth into the material. Three constants contained in the strain functions have to be determined by calibration tests; they are related to three general constants and the elastic material constants to establish applicability to an orthotropic material. Expressions for the planar residual-stress components in the material-symmetry directions are then devel oped, and from Mohr's stress circle, the principal residual stresses and directions are determined.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

A Cas9-based toolkit to program gene expression in Saccharomyces cerevisiae

Despite the extensive use of Saccharomyces cerevisiae as a platform for synthetic biology, strain engineering remains slow and laborious. Here, we employ CRISPR/Cas9 technology to build a cloning-free toolkit that addresses commonly encountered obstacles in metabolic engineering, including chromosomal integration locus and promoter selection, as well as protein localization and solubility. The toolkit includes 23 Cas9-sgRNA plasmids, 37 promoters of various strengths and temporal expression profiles, and 10 protein-localization, degradation and solubility tags. We facilitated the use of these parts via a web-based tool, that automates the generation of DNA fragments for integration. Our system builds upon existing gene editing methods in the thoroughness with which the parts are standardized and characterized, the types and number of parts available and the ease with which our methodology can be used to perform genetic edits in yeast. We demonstrated the applicability of this toolkit by optimizing the expression of a challenging but industrially important enzyme, taxadiene synthase (TXS). This approach enabled us to diagnose an issue with TXS solubility, the resolution of which yielded a 25-fold improvement in taxadiene production

Children's Medicines in Tanzania: A National Survey of Administration Practices and Preferences.

The dearth of age-appropriate formulations of many medicines for children poses a major challenge to pediatric therapeutic practice, adherence, and health care delivery worldwide. We provide information on current administration practices of pediatric medicines and describe key stakeholder preferences for new formulation characteristics. We surveyed children aged 6-12 years, parents/caregivers over age 18 with children under age 12, and healthcare workers in 10 regions of Tanzania to determine current pediatric medicine prescription and administration practices as well as preferences for new formulations. Analyses were stratified by setting, pediatric age group, parent/caregiver education, and healthcare worker cadre. Complete data were available for 206 children, 202 parents/caregivers, and 202 healthcare workers. Swallowing oral solid dosage forms whole or crushing/dissolving them and mixing with water were the two most frequently reported methods of administration. Children frequently reported disliking medication taste, and many had vomited doses. Healthcare workers reported medicine availability most significantly influences prescribing practices. Most parents/caregivers and children prefer sweet-tasting medicine. Parents/caregivers and healthcare workers prefer oral liquid dosage forms for young children, and had similar thresholds for the maximum number of oral solid dosage forms children at different ages can take. There are many impediments to acceptable and accurate administration of medicines to children. Current practices are associated with poor tolerability and the potential for under- or over-dosing. Children, parents/caregivers, and healthcare workers in Tanzania have clear preferences for tastes and formulations, which should inform the development, manufacturing, and marketing of pediatric medications for resource-limited settings

The role of assistance dogs in society

Assistance dogs are specially trained to undertake a variety of tasks to help individuals with disabilities. This review gives an overview of the different types of assistance dogs in the UK, including guide dogs, hearing dogs, mobility assistance dogs, service dogs and dual purpose dogs. The literature describes many benefits of assistance dogs, including their impact on physical wellbeing and safety of their ‘owners,’ as well as on psychological wellbeing and social inclusion. The role of assistance dogs in society is widely recognized by the public, but is not currently acknowledged in government social policy. The current evidence on the benefits of assistance dogs is limited by the type and scale of current research. This article highlights the need for independent funding for high quality research to enable social care and policy makers to make evidence-based decisions on the value of assistance dogs to people with disabilities