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

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The document attached has been archived with permission from the editor of the Medical Journal of Australia.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

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

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

WHEN TRAINING GETS TRUMPED: HOW DUAL-TASK INTERFERENCE INHIBITS SECURITY TRAINING

Security training programs are an important intervention to protect users and organizations against security threats. Unfortunately, users often ignore their training and engage in poor security behaviors. We explain how dual-task interference (DTI) is a primary cause of security training disregard. DTI is a cognitive limitation wherein humans cannot perform more than one task simultaneously without experiencing a deterioration of performance. In our context, we hypothesize how prompting users to perform security behaviors during high-DTI times may derail one’s previous security training, resulting in less secure behaviors. We test our hypotheses in an experiment that compares users’ adherence to security training during low-DTI and high-DTI times in a realistic context. We found that performing security behaviors during low-DTI times increased adherence to prior security training by 31% compared to performing behaviors during high-DTI times. The results have implications for using DTI as a theoretical framework for understanding security behaviors, prompting users to perform security behaviors during times that will maximize adherence to past security training, and considering humans’ neurological limitations when designing security training and intervention programs

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

No abstract is available for this item

The Design and Implementation of Elastic Quotas: A System for Flexible File System Management

We introduce elastic quotas, a disk space management technique that makes disk space an elastic resource like CPU and memory. Elastic quotas allow all users to use unlimited amounts of available disk space while still providing system administrators the ability to control how the disk space is allocated among users. Elastic quotas maintain existing persistent file semantics while supporting user-controlled policies for removing files when the file system becomes too full. We have implemented an elastic quota system in Solaris and measured its performance. The system is simple to implement, requires no kernel modifications, and is compatible with existing disk space management methods. Our results show that elastic quotas are an effective, low-overhead solution for flexible file system management

S-Duality and the Dyon Spectrum in N=2 Super Yang-Mills Theory

We study the dyon spectrum in $N=2$ Super Yang-Mills theory with gauge group $SU(2)$ coupled to $N_f$ matter multiplets in the fundamental representation. For magnetic charge one and two we determine the spectrum explicitly and show that it is in agreement with the duality predictions of Seiberg and Witten. We briefly discuss the extension to higher charge monopoles for the self-dual $N_f=4$ case and argue that the conjectured spectrum of dyons predicts the existence of certain harmonic spinors on the moduli space of higher charge monopoles.Comment: 32 pages, harvma

Magnetic Monopoles in String Theory

Magnetic monopole solutions to heterotic string theory are discussed in toroidal compactifications to four spacetime dimensions. Particular emphasis is placed on the relation to previously studied fivebrane solutions in ten dimensions and on the possibility of constructing exact monopole solutions related to symmetric fivebranes.Comment: 24 pages (Corrected title