Independent and combined effects of exercise and vitamin D on muscle morphology, function and falls in the elderly

Regular exercise, particularly progressive resistance training (PRT), is recognized as one of the most effective strategies to prevent age-related muscle loss (sarcopenia), but its effects on muscle function are mixed. However, emerging data indicates that high velocity PRT (fast concentric muscle contractions) is more effective for improving functional outcomes than traditional PRT. In terms of falls prevention, high-challenging balance training programs appear to be most effective. There is also compelling evidence that supplemental vitamin D is an effective therapeutic option for falls prevention. The findings from a recent meta-analysis revealed that supplemental vitamin D at a dose of at least 700–1,000 IU/d or an achieved serum 25(OH)D level of at least 60 nmol/L was associated with reduced falls risk among older individuals. Based on these findings, it is possible that the combination of exercise and vitamin D could have a synergistic effect on muscle morphology and function, particularly since both interventions have been shown to have beneficial effects on type II “fast twitch” muscle fibers and systemic inflammation, which have both been linked to losses in muscle mass and function. Unfortunately however, the findings from the limited number of factorial 2 × 2 design RCTs indicate that additional vitamin D does not enhance the effects of exercise on measures of muscle morphology, function or falls risk. However, none of these trials were adequately powered to detect a “synergistic” effect between the two treatment strategies, but it is likely that if an exercise-by-vitamin D interaction does exist, it may be limited to situations when vitamin D deficiency/insufficiency is corrected. Further targeted research in “high risk” groups is still needed to address this question, and evaluate whether there is a threshold level of serum 25(OH)D to maximize the effects of exercise on muscle and falls risk.

Ultrastructural analysis of plastids in angiosperm pollen tubes

When Rhododendron pollen tubes are cultured in the dark, electron-dense bodies are present that appear to be a metabolically altered form of a proplastid that is difficult to fix for electron microscopy, and whose membranes may not be intact. When similar pollen tubes are cultured in a dark/light regime, ultrastructurally well-defined proplastids are present after fixation in glutaraldehyde with PIPES buffer and tannic acid, followed by osmic acid. This fixation technique also gave the best ultrastructural images of those proplastids in pollen tubes grown in the dark. Pollen tube plastids have the potential to become chromoplasts when cultured in a dark/light regime as evidenced by the presence of branched tubules characteristic of these organelles. Light appears to be a hitherto neglected environmental factor involved in regulating pollen tube growth. This improved fixation procedure demonstrates the bilayered nature of the membranes surrounding sperm cells and the existence of cytoplasmic channels connecting sperm cell and pollen tube plasma membranes.

Self-assembly and morphology in double crystalline diblock copolymer/homopolymer blends with competitive hydrogen bonding

Block copolymers are of particular interest due to their ability to form a rich variety of nanostructures via self-assembly [1]. The self-assembly via competitive hydrogen bonding is a novel concept which is based on the competition between different blocks of the block copolymer to form more than one kind of intermolecular interaction with the complimentary polymer in the system. Recently, Guo and co-workers have proven that careful selection of the polymers specifically the block copolymer, and the experimental conditions can lead to self-assembled structures in blends and complexes exhibiting competitive hydrogen bonding [2-5].

Morphology evolution during annealing and electrical conductivity of titania nanotube films

Titania nanotube films were produced by anodization of titanium foil. The titania nanotube films were annealed at different temperatures. Morphology evolution, phase transformation and electrical conductivity of the titania nanotubes were studied. Results showed that the nanotube walls became rough, porous and even collapsed after annealed at 400, 500 and 600°C respectively. Titania anatase phase formed after annealed at 400°C; the amount of anatase phase increased as the annealing temperature increased. The conductivity of the nanotube film annealed at 400°C was improved greatly compared with the conductivity of the as-anodized nanotube film. However, the conductivity of the nanotube films annealed at higher temperatures decreased. The effect of the morphology on the electronic conductivity of the titania nanotube films was discussed.

Chronic stress alters the density and morphology of microglia in a subset of stress-responsive brain regions

The current study, in parallel experiments, evaluated the impact of chronic psychological stress on physiological and behavioural measures, and on the activation status of microglia in 15 stress-responsive brain regions. Rats were subjected, for 14 days, to two 30 min sessions of restraint per day, applied at random times each day. In one experiment the effects of stress on sucrose preference, weight gain, core body temperature, and struggling behaviour during restraint, were determined. In the second experiment we used immunohistochemistry to investigate stress-induced changes in ionized calcium-binding adaptor molecule-1 (Iba1), a marker constitutively expressed by microglia, and major histocompatibility complex-II (MHC-II), a marker often expressed on activated microglia, in a total of 15 stress-responsive nuclei. We also investigated cellular proliferation in these regions using Ki67 immunolabelling, to check for the possibility of microglial proliferation. Collectively, the results we obtained showed that chronic stress induced a significant increase in anhedonia, a decrease in weight gain across the entire observation period, a significant elevation in core body temperature during restraint, and a progressive decrease in struggling behaviour within and over sessions. With regard to microglial activation, chronic stress induced a significant increase in the density of Iba1 immunolabelling (nine of 15 regions) and the number of Iba1-positive cells (eight of 15 regions). Within the regions that exhibited an increased number of Iba1-positive cells after chronic stress, we found no evidence of a between group difference in the number of MHC-II or Ki67 positive cells. In summary, these results clearly demonstrate that chronic stress selectively increases the number of microglia in certain stress-sensitive brain regions, and also causes a marked transition of microglia from a ramified-resting state to a non-resting state. These findings are consistent with the view that microglial activation could play an important role in controlling and/or adapting to stress.

Morphology of ball milled graphite

The Scanning Electron Microscope (SEM) is used to characterize the morphology of ball milled graphite samples, which can be helpful for the further understanding of the samples' spectroscopic and absorptive properties.

Cancrinella and Costatumulus (Brachiopoda) from the Permian of South Mongolia and South China : their morphology, biostratigraphy and distribution

Two brachiopod genera, Cancrinella Fredericks and Costatumulus Waterhouse, are studied from the Permian of South Mongolia and South China. Many of the specimens previously described as Cancrinella are revised and assigned to Costatumulus. The new data presented in this paper indicate that these two genera are similar to each other, but are distinguishable by different features in relation to their morphology. Several species of both genera are described here, providing critical new information on the morphology and taxonomy of Cancrinella and Costatumulus. The reported biostratigraphical information reveals that species of Cancrinella are present from the Lower Carboniferous (Tournaisian) to Middle Permian (Capitanian), whereas species of Costatumulus are mostly restricted to the Lower Permian (Sakmarian) to Upper Permian (Changhsingian). An analysis of the palaeogeographical distribution of Cancrinella and Costatumulus reveals that Cancrinella was more commonly distributed in the Northern Transitional Zone and the Boreal Realm, in contrast to Costatumulus, which tended to be more common in the Southern Transitional Zone and Gondwanan Realm.

Influence of ionic liquids on the electrical conductivity and morphology of PEDOT:PSS films

Small-molecule nonvolatile additives based on ionic liquids (IL) as electrical conductivity enhancer in Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) was studied. Ionic liquids were investigated in the synthesis of self-assembled, highly organized hybrid nanostructures due to their ability as supramolecular solvents. Different percentage of five ionic liquids, such as 1-butyl-3-methylimidazolium tetrafluoroborate (bmim) F 4 and 1-butyl-3-methylimidazolium bromide (bmim)Br were added to a PEDOT:PSScommercial dispersion. Films of pure PEDOT:PSS showed an average conductivity of 14 S cm-1, which corresponded to the value range given by the supplier. AFM images showed that IL induced the formation of a three-dimensional conducting network with smaller PEDOT domains. The ionic character of the films was significantly increased because of the presence of ionic liquids, which can be used effectively in optoelectronic devices.

Controlling morphology and porosity of porous siloxane membranes through water content of precursor microemulsion

Here we report a facile method for controlling the morphology and porosity of porous siloxane membranes through manipulation of the water content of precursor microemulsions. The polymerizable microemulsion precursors consisted of a methacrylate-terminated siloxane macromonomer (MTSM) as the oil phase, nonionic surfactant (Teric G9A8), water, and cosurfactant (isopropanol). Photo-polymerization of the oil phase in the parent microemulsion solutions resulted in polymeric solids, and subsequent removal of the extractable components yielded porous PDMS membranes. The pre-cured parent microemulsion solutions and post-cured polymers were characterized by small angle X-ray scattering (SAXS) while the nanostructures of extracted porous polymer membranes were characterized by SAXS, scanning electron microscopy (SEM) and mercury porosimetry. The results indicated that nano- and micro-structures of the membranes could be modulated by the water content of the precursor microemulsions. Further, in situ photo-rheometry was used to follow the microemulsion polymerization process. The rate of polymerization and the mechanical properties of the resulting PDMS membranes also depend on the water content of precursor microemulsions. This study demonstrates a simple approach to the fabrication of a variety of novel porous PDMS membranes with controllable morphology and porosity.

The implications of adult morphology for clutch size in the flatback turtle (Natator depressa)

When the mean adult length and mean clutch volume of marine turtles are examined, a clear pattern for larger species to lay larger clutches is evident, in accord with predictions that female size constrains the available space for carrying eggs. However, when compared with this general trend, the volume of clutches laid by flatback turtles (Natator depressa) are smaller than expected. The implication is that the unusually flat morphology of flatback turtles, provides an additional constraint on their egg carrying capacity.

Interspecific differences in the Diel Vertical Migration of Marine Copepods : the Implications of size, color, and morphology

Samples collected by continuous plankton recorders (CPRs) between 1948 and 1992 were used to describe the diel vertical migration (DVM) behavior of 41 copepod taxa in the northeast Atlantic between 45 and 55?N and 11 and 31?W. A total of 13,622 samples, each representing - 18.5 km (10 nm) of tow, were analyzed. Since CPRs are towed in near-surface waters, taxa that exhibit DVM occur predominantly in samples taken at night. Larger taxa showed significantly stronger DVM, with body size explaining 47% of the intertaxa variation in DVM. For small taxa (< 1 mm wide) the residual variation in DVM was correlated with carotenoid pigment levels but not with body morphology, with more heavily pigmented taxa exhibiting DVM. For larger taxa (> 1 mm wide) the residual variation in DVM was correlated with body morphology but not with carotenoid pigment levels, with more elongate copepods not exhibiting DVM.