Precise Control of Molecular Self-Diffusion in Isoreticular and Multivariate Metal-Organic Frameworks.

Understanding the factors that affect self-diffusion in isoreticular and multivariate (MTV) MOFs is key to their application in drug delivery, separations, and heterogeneous catalysis. Here, we measure the apparent self-diffusion of solvents saturated within the pores of large single crystals of MOF-5, IRMOF-3 (amino-functionalized MOF-5), and 17 MTV-MOF-5/IRMOF-3 materials at various mole fractions. We find that the apparent self-diffusion coefficient of N,N-dimethylformamide (DMF) may be tuned linearly between the diffusion coefficients of MOF-5 and IRMOF-3 as a function of the linker mole fraction. We compare a series of solvents at saturation in MOF-5 and IRMOF-3 to elucidate the mechanism by which the linker amino groups tune molecular diffusion. The ratio of the self-diffusion coefficients for solvents in MOF-5 to those in IRMOF-3 is similar across all solvents tested, regardless of solvent polarity. We conclude that average pore aperture, not solvent-linker chemical interactions, is the primary factor responsible for the different diffusion dynamics upon introduction of an amino group to the linker

Morphological and Ultrastructural Studies of Plant Cuticular Membranes. I. Sun and Shade Leaves of Quercus velutina (Fagaceae)

This is the publisher's version, also available electronically from http://www.jstor.org.Sun and shade leaves of Quercus velutina Lam. were evaluated with respect to differences in gross anatomy, morphology, and cuticle (cuticular membrane (CM|) ultrastructure and micromorphology. Sun leaves are smaller, with more deeply lobed margins, and have more stomata, thicker mesophylls, and thicker CMs when compared with shade leaves. Cuticular membranes are thicker on both the adaxial and abaxial surfaces of sun leaves as a result of deposition of more cuticular components and scaly epicuticular wax. Both the adaxial and abaxial epidermises have the same basic fine structure in sun and shade leaves with respect to the outer periclinal cell wall and overlying CM. The cell wall is lamellate and the CM is composed of a two-zoned, reticulate cuticular layer and an amorphous cuticle proper. The outer periclinal wall and associated CM of the adaxial epidermis is thicker than that of the abaxial epidermis with both epidermal layers thicker in sun leaves compared with shade leaves. Difference in thickness of both epidermal layers, between sun and shade leaves, can be attributed to an increase in the inner reticulate region of the CM of sun leaves. Cells of the abaxial epidermis have ultrastructurally different CMs. Nonstomatal epidermal cells have a distinct amorphous cuticle proper whereas subsidiary cells have reticulations that traverse most of the outer CM. Guard cells have radially aligned reticulations through the entire outer CM and, therefore, lack an amorphous cuticle proper. Moreover, an internal CM, which is only sparsely reticulate, lines substomatal chambers. The internal CM of sun leaves is thicker and extends considerably deeper into substomatal chambers

Oocyte cryopreservation as an adjunct to the assisted reproductive technologies

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included. See page 2 of PDF for this item.Keith L Harrison, Michelle T Lane, Jeremy C Osborn, Christine A Kirby, Regan Jeffrey, John H Esler and David Mollo

Sine-Wave Electrical Stimulation Initiates a Voltage-Gated Potassium Channel-Dependent Soft Tissue Response Characterized by Induction of Hemocyte Recruitment and Collagen Deposition

Soft tissue repair is a complex process that requires specific communication between multiple cell types to orchestrate effective restoration of physiological functions. Macrophages play a critical role in this wound healing process beginning at the onset of tissue injury. Understanding the signaling mechanisms involved in macrophage recruitment to the wound site is an essential step for developing more effective clinical therapies. Macrophages are known to respond to electrical fields, but the underlying cellular mechanisms mediating this response is unknown. This study demonstrated that low‐amplitude sine‐wave electrical stimulation (ES) initiates a soft tissue response in the absence of injury in Procambarus clarkii. This cellular response was characterized by recruitment of macrophage‐like hemocytes to the stimulation site indicated by increased hemocyte density at the site. ES also increased tissue collagen deposition compared to sham treatment (P \u3c 0.05). Voltage‐gated potassium (KV) channel inhibition with either 4‐aminopyridine or astemizole decreased both hemocyte recruitment and collagen deposition compared to saline infusion (P \u3c 0.05), whereas inhibition of calcium‐permeable channels with ruthenium red did not affect either response to ES. Thus, macrophage‐like hemocytes in P. clarkii elicit a wound‐like response to exogenous ES and this is accompanied by collagen deposition. This response is mediated by KV channels but independent of Ca2+ channels. We propose a significant role for KV channels that extends beyond facilitating Ca2+ transport via regulation of cellular membrane potentials during ES of soft tissue

Ion Channel Signaling Influences Cellular Proliferation and Phagocyte Activity During Axolotl Tail Regeneration

Little is known about the potential for ion channels to regulate cellular behaviors during tissue regeneration. Here, we utilized an amphibian tail regeneration assay coupled with a chemical genetic screen to identify ion channel antagonists that altered critical cellular processes during regeneration. Inhibition of multiple ion channels either partially (anoctamin1/Tmem16a, anoctamin2/Tmem16b, KV2.1, KV2.2, L-type CaV channels and H/K ATPases) or completely (GlyR, GABAAR, KV1.5 and SERCA pumps) inhibited tail regeneration. Partial inhibition of tail regeneration by blocking the calcium activated chloride channels, anoctamin1&2, was associated with a reduction of cellular proliferation in tail muscle and mesenchymal regions. Inhibition of anoctamin 1/2 also altered the post-amputation transcriptional response of p44/42 MAPK signaling pathway genes, including decreased expression of erk1/erk2. We also found that complete inhibition via voltage gated K+ channel blockade was associated with diminished phagocyte recruitment to the amputation site. The identification of H+ pumps as required for axolotl tail regeneration supports findings in Xenopus and Planaria models, and more generally, the conservation of ion channels as regulators of tissue regeneration. This study provides a preliminary framework for an in-depth investigation of the mechanistic role of ion channels and their potential involvement in regulating cellular proliferation and other processes essential to wound healing, appendage regeneration, and tissue repair

Palaeofibulus Gen. nov., a Clamp-Bearing Fungus from the Triassic of Antarctica

No abstract is available for this item

Multistep Solid-State Organic Synthesis of Carbamate-Linked Covalent Organic Frameworks.

Herein, we demonstrate the first example of a multistep solid-state organic synthesis, in which a new imine-linked two-dimensional covalent organic framework (COF-170, 1) was transformed through three consecutive postsynthetic modifications into porous, crystalline cyclic carbamate and thiocarbamate-linked frameworks. These linkages are previously unreported and inaccessible through de novo synthesis. While not altering the overall connectivity of the framework, these chemical transformations induce significant conformational and structural changes at each step, highlighting the key importance of noncovalent interactions and conformational flexibility to COF crystallinity and porosity. These transformations were assessed using 15N multiCP-MAS NMR spectroscopy, providing the first quantitation of yields in COF postsynthetic modification reactions, as well as of amine defect sites in imine-linked COFs. This multistep COF linkage postsynthetic modification represents a significant step toward bringing the precision of organic solution-phase synthesis to extended solid-state compounds

Prioritizing Conservation of Ungulate Calving Resources in Multiple-Use Landscapes

BACKGROUND: Conserving animal populations in places where human activity is increasing is an ongoing challenge in many parts of the world. We investigated how human activity interacted with maternal status and individual variation in behavior to affect reliability of spatially-explicit models intended to guide conservation of critical ungulate calving resources. We studied Rocky Mountain elk (Cervus elaphus) that occupy a region where 2900 natural gas wells have been drilled. METHODOLOGY/PRINCIPAL FINDINGS: We present novel applications of generalized additive modeling to predict maternal status based on movement, and of random-effects resource selection models to provide population and individual-based inference on the effects of maternal status and human activity. We used a 2×2 factorial design (treatment vs. control) that included elk that were either parturient or non-parturient and in areas either with or without industrial development. Generalized additive models predicted maternal status (parturiency) correctly 93% of the time based on movement. Human activity played a larger role than maternal status in shaping resource use; elk showed strong spatiotemporal patterns of selection or avoidance and marked individual variation in developed areas, but no such pattern in undeveloped areas. This difference had direct consequences for landscape-level conservation planning. When relative probability of use was calculated across the study area, there was disparity throughout 72-88% of the landscape in terms of where conservation intervention should be prioritized depending on whether models were based on behavior in developed areas or undeveloped areas. Model validation showed that models based on behavior in developed areas had poor predictive accuracy, whereas the model based on behavior in undeveloped areas had high predictive accuracy. CONCLUSIONS/SIGNIFICANCE: By directly testing for differences between developed and undeveloped areas, and by modeling resource selection in a random-effects framework that provided individual-based inference, we conclude that: 1) amplified selection or avoidance behavior and individual variation, as responses to increasing human activity, complicate conservation planning in multiple-use landscapes, and 2) resource selection behavior in places where human activity is predictable or less dynamic may provide a more reliable basis from which to prioritize conservation action

Performativity and primary teacher relations

A performativity discourse currently pervades teachers' work. It is a discourse that relies on teachers and schools instituting self-disciplinary measures to satisfy newly transparent public accountability and it operates alongside a market discourse. The introduction of the performativity discourse has affected teacher relations at three levels of professional work: with students, colleagues and local advisor/inspectors. Ethnographic research with primary teachers - which focused on their experience of Ofsted inspections in six schools over periods of up to four years - is the source of this paper. The paper argues that a humanist discourse prevalent in teacher relations with students, colleagues and advisor/inspectors has been challenged by a performativity discourse that: distances teachers from students and creates a dependency culture in opposition to previous mutual and intimate relations; creates self disciplining teams that marginalize individuality and stratifies collegial relations in opposition to previous relations where primary teachers sought consensus; and creates subjugatory, contrived and de-personalized relations between local advisors/inspectors in preference to previous partnership relations. The paper concludes that the change in relations is an indicator of fundamental change to social relations but that primary teachers are in a good position to influence the performativity discourse, albeit it a struggle, by reconstituting it through the maintenance of humanist relations