Objectively Measured Walking Duration and Sedentary Behaviour and Four-Year Mortality in Older People

BackgroundPhysical activity is an important component of health. Recommendations based on sensor measurements are sparse in older people. The aim of this study was to analyse the effect of objectively measured walking and sedentary duration on four-year mortality in community-dwelling older people.MethodsBetween March 2009 and April 2010, physical activity of 1271 participants (≥65 years, 56.4% men) from Southern Germany was measured over one week using a thigh-worn uni-axial accelerometer (activPAL; PAL Technologies, Glasgow, Scotland). Mortality was assessed during a four-year follow-up. Cox-proportional-hazards models were used to estimate the associations between walking (including low to high intensity) and sedentary duration with mortality. Models were adjusted for age and sex, additional epidemiological variables, and selected biomarkers.ResultsAn inverse relationship between walking duration and mortality with a minimum risk for the 3rd quartile (102.2 to128.4 minutes walking daily) was found even after multivariate adjustment with HRs for quartiles 2 to 4 compared to quartile 1 of 0.45 (95%-CI: 0.26; 0.76), 0.18 (95%-CI: 0.08; 0.41), 0.39 (95%-CI: 0.19; 0.78), respectively. For sedentary duration an age- and sex-adjusted increased mortality risk was observed for the 4th quartile (daily sedentary duration ≥1137.2 min.) (HR 2.05, 95%-CI: 1.13; 3.73), which diminished, however, after full adjustment (HR 1.63, 95%-CI: 0.88; 3.02). Furthermore, our results suggest effect modification between walking and sedentary duration, such that in people with low walking duration a high sedentary duration was noted as an independent factor for increased mortality.ConclusionsIn summary, walking duration was clearly associated with four-year overall mortality in community-dwelling older people.     

Salt‐enhanced cultivation as a morphology engineering tool for filamentous actinomycetes: Increased production of labyrinthopeptin A1 in Actinomadura namibiensis

Salt‐enhanced cultivation as a morphology engineering tool for the filamentous actinomycete Actinomadura namibiensis was evaluated in 500‐mL shaking flasks (working volume 100 mL) with the aim of increasing the concentration of the pharmaceutically interesting peptide labyrinthopeptin A1. Among the inorganic salts added to a complex production medium, the addition of (NH₄)₂SO₄ led to the highest amount of labyrinthopeptin A1 production. By using 50 mM (NH₄)₂SO₄, the labyrinthopeptin A1 concentration increased up to sevenfold compared to the non‐supplemented control, resulting in 325 mg L^?1 labyrinthopeptin A1 after 10 days of cultivation. The performance of other ammonium‐ and sulfate‐containing salts (e.g., NH₄Cl, K₂SO₄) was much lower than the performance of (NH₄)₂SO₄. A positive correlation between the uptake of glycerol as one of the main carbon sources and nongrowth‐associated labyrinthopeptin productivity was found. The change in the cell morphology of A. namibiensis in conjunction with increased osmolality by the addition of 50 mM (NH₄)₂SO₄, was quantified by image analysis. A. namibiensis always developed a heterogeneous morphology with pellets and loose mycelia present simultaneously. In contrast to the non‐supplemented control, the morphology of (NH₄)₂SO₄‐supplemented cultures was characterized by smaller and circular pellets that were more stable against disintegration in the stationary production phase.     

Scale-up from shake flasks to fermenters in batch and continuous mode with Corynebacterium glutamicum on lactic acid based on oxygen transfer and pH

Scale-up from shake flasks to fermenters has been hampered by the lack of knowledge concerning the influence of operating conditions on mass transfer, hydromechanics, and power input. However, in recent years the properties of shake flasks have been described with empirical models. A practical scale-up strategy for everyday use is introduced for the scale-up of aerobic cultures from shake flasks to fermenters in batch and continuous mode. The strategy is based on empirical correlations of the volumetric mass transfer coefficient (k(L) a) and the pH. The accuracy of the empirical k(L) a correlations and the assumptions required to use these correlations for an arbitrary biological medium are discussed. To determine the optimal pH of the culture medium a simple laboratory method based on titration curves of the medium and a mechanistic pH model, which is solely based on the medium composition, is applied. The effectiveness of the scale-up strategy is demonstrated by comparing the behavior of Corynebacterium glutamicum on lactic acid in shake flasks and fermenters in batch and continuous mode. The maximum growth rate (micro(max) = 0.32 h(-1)) and the oxygen substrate coefficient (Y O2 /S= 0.0174 mol/l) of C. glutamicum on lactic acid were equal for shake flask, fermenter, batch, and continuous cultures. The biomass substrate yield was independent of the scale, but was lower in batch cultures (Y(X/S) = 0.36 g/g) than in continuous cultures (Y(X/S) = 0.45 g/g). The experimental data (biomass, respiration, pH) could be described with a simple biological model combined with a mechanistic pH model.     

The Sandfish＇s Skin： Morphology, Chemistry and Reconstruction

The sandfish is a lizard having the remarkable ability to move in desert sand in a swimming-like fashion. The most outstanding adaptations to this mode of life are the low friction behaviour and the extensive abrasion resistance of the sandfish skin against sand, outperforming even steel. We investigated the topography, the composition and the mechanical properties of sandfish scales. These consist of glycosylated keratins with high amount of sulphur but no hard inorganic material, such as silicates or lime. Remarkably, atomic force microscopy shows an almost complete absence of attractive forces between the scale surface and a silicon tip, suggesting that this is responsible for the unusual tribological properties. The unusual glycosylation of the keratins was found to be absolutely necessary for the described phenomenon. The scales were dissolved and reconstituted on a polymer surface resulting in properties similar to the original scale. Thus, we provide a pathway towards exploitation of the reconstituted scale material for future engineering applications.     

Respiratory uncoupling in skeletal muscle delays death and diminishes age-related disease

Age-related disease, not aging per se, causes most morbidity in older humans. Here we report that skeletal muscle respiratory uncoupling due to UCP1 expression diminishes age-related disease in three mouse models. In a longevity study, median survival was increased in UCP mice (animals with skeletal muscle-specific UCP1 expression), and lymphoma was detected less frequently in UCP female mice. In apoE null mice, a vascular disease model, diet-induced atherosclerosis was decreased in UCP animals. In agouti yellow mice, a genetic obesity model, diabetes and hypertension were reversed by induction of UCP1 in skeletal muscle. Uncoupled mice had decreased adiposity, increased temperature and metabolic rate, elevated muscle SIRT and AMP kinase, and serum characterized by increased adiponectin and decreased IGF-1 and fibrinogen. Accelerating metabolism in skeletal muscle does not appear to impact aging but may delay age-related disease.     

A microcarrier-based cultivation system for expansion of primary mesenchymal stem cells

Microcarrier cultures have been shown to allow extensive cell expansion of tissue engineering relevant cells, such as chondrocytes, while maintaining their phenotype. Our aim was to investigate the in vitro three-dimensional expansion of porcine bone-marrow-derived primary mesenchymal stem cells (MSC) using commercially available Cytodex type 1, type 2, and type 3 microcarriers. In comparison, the Cytodex type 1 microcarriers showed the best results for adherence with over 80% adherent cells after 3 h of incubation, analyzed by the Poisson distribution. Different start cell densities ranging from 1 to 3 x 106 cells per 100 cm2 had only a minor influence on adhesion. The proliferation was examined on Cytodex type 1 microcarriers over a cultivation time of 28 days, which could reveal cell growth and proof of cells recolonizing freshly added microcarriers. Scanning electron microscopy displayed appropriate cell morphology and confirmed cell proliferation. After enzymatic harvest from microcarriers, the osteogenic and chondrogenic differentiation of these cells was induced and shown by relevant histochemistry, such as von Kossa and Alcian blue staining. Totaling the results, we have shown that the three-dimensional expansion of MSC on microcarriers represents a beneficial alternative to the conventional two-dimensional monolayer cultivation method.     

K2P18.1 translates T cell receptor signals into thymic regulatory T cell development

It remains largely unclear how thymocytes translate relative differences in T cell receptor (TCR) signal strength into distinct developmental programs that driv...     

The Sandfish's Skin:Morphology,Chemistry and Reconstruction

The sandfish is a lizard having the remarkable ability to move in desert sand in a swimming-like fashion. The most out-standing adaptations to this mode of life are the low friction behaviour and the extensive abrasion resistance of the sandfish skin against sand, outperforming even steel. We investigated the topography, the composition and the mechanical properties of sandfish scales. These consist of glycosylated keratins with high amount of sulphur but no hard inorganic material, such as silicates or lime. Remarkably, atomic force microscopy shows an almost complete absence of attractive forces between the scale surface and a silicon tip, suggesting that this is responsible for the unusual tribological properties. The unusual glycosylation of the keratins was found to be absolutely necessary for the described phenomenon. The scales were dissolved and reconstituted on a polymer surface resulting in properties similar to the original scale. Thus, we provide a pathway towards exploitation of the reconstituted scale material for future engineering applications.     

Differentiation of isolated wheat zygotes into embryos and normal plants

Efficient and reproducible embryo development has been obtained from fertilized wheat (Triticum aestivum L.) egg cells isolated 3–6 h after hand-pollination of emasculated spikes. It is possible to routinely isolate viable zygotes from about 75% of the excised ovaries from cultivars of both winter and spring types. Co-culture with barley microspores which had been stimulated to sporophytic development resulted in embryonic development of the cultivated wheat zygotes. Within 23 h of pollination; the zygotes underwent their first cell division. They proceeded to develop into club-shaped embryos, most of which turned subsequently to dorsiventral differentiation. The morphological patterns of in-vitro-grown embryos were in accordance with those of normal zygotic embryos growing in planta. The formation of twin or multiple embryos originating from a single zygote was dependent on genotype and exogeneously supplied auxin. Upon transfer onto a suitable solidified medium, zygote-derived embryos usually germinated and developed into plants. After optimizing the feeder system, the nutrient medium and the concentration of 2,4-dichloro phenoxyacetic acid (2,4-D), more than 80 and 90% of the zygotes eventually developed into plants in genotypes Florida and Veery #5, respectively. All regenerated plants were morphologically normal and fertile. The in-vitro development from isolated zygotes of a higher-plant species into typically patterned zygotic embryos is shown here for the first time. Since the entire process, including early zygotic development, is now freely accessible to observation and micromanipulation, the method presented opens up new approaches in fundamental as well as applied fields of reproductive biology. Received: 4 September 1997 / Accepted: 28 November 1997