Development and Validation of a New Method to Measure Walking Speed in Free-Living Environments Using the Actibelt? Platform

Walking speed is a fundamental indicator for human well-being. In a clinical setting, walking speed is typically measured by means of walking tests using different protocols. However, walking speed obtained in this way is unlikely to be representative of the conditions in a free-living environment. Recently, mobile accelerometry has opened up the possibility to extract walking speed from long-time observations in free-living individuals, but the validity of these measurements needs to be determined. In this investigation, we have developed algorithms for walking speed prediction based on 3D accelerometry data (actibelt®) and created a framework using a standardized data set with gold standard annotations to facilitate the validation and comparison of these algorithms. For this purpose 17 healthy subjects operated a newly developed mobile gold standard while walking/running on an indoor track. Subsequently, the validity of 12 candidate algorithms for walking speed prediction ranging from well-known simple approaches like combining step length with frequency to more sophisticated algorithms such as linear and non-linear models was assessed using statistical measures. As a result, a novel algorithm employing support vector regression was found to perform best with a concordance correlation coefficient of 0.93 (95%CI 0.92–0.94) and a coverage probability CP1 of 0.46 (95%CI 0.12–0.70) for a deviation of 0.1 m/s (CP2 0.78, CP3 0.94) when compared to the mobile gold standard while walking indoors. A smaller outdoor experiment confirmed those results with even better coverage probability. We conclude that walking speed thus obtained has the potential to help establish walking speed in free-living environments as a patient-oriented outcome measure.     

Absence of Significant Light-Induced Changes in cAMP Levels in Sporangiophores of Phycomyces blakesleeanus

We were unable to find transient changes in the amount of cAMP or cGMP that had been proposed to mediate the light-growth response in sporangiophores of Phycomyces blakesleeanus.     

Types of sesquiterpene-coumarin ethers from Achillea ochroleuca and Artemisia tripartita

In addition to known derivatives, four new sesquiterpene-coumarin ethers were isolated from the roots of Achillea ochroleuca and Artemisia tripartita and identified by ¹H and ¹³C NMR spectroscopy, including lanthanide induced shifts. The new compounds are isofraxidin derived ethers which differ from the previously described derivatives by ring cleavage and methyl migration within the terpenoid unit. The chemosystematic importance of sesquiterpene-coumarin ether accumulation within the two genera is briefly discussed.     

A new phage typing scheme forProteus mirabilis andProteus vulgaris strains

A new bacteriophage typing set, composed of 22 phages, was established as a tool for differentiation ofProteus strains. All the phages were tailed and included 4 morphological types (A1, A2, B1 and C1). They were classified into the familiesMyoviridae, Siphoviridae andPodoviridae. From the set, 19 phages had double-stranded DNA and 3 were single-stranded DNA phages.     

Homologs of the yeast neck filament associated genes: isolation and sequence analysis of Candida albicans CDC3 and CDC10

Morphogenesis in the yeast Saccharomyes cerevisiae consists primarily of bud formation. Certain cell division cycle (CDC) genes, CDC3, CDC10, CDC11, CDC12, are known to be involved in events critical to the pattern of bud growth and the completion of cytokinesis. Their products are associated with the formation of a ring of neck filaments that forms at the region of the mother cell-bud junction during mitosis. Morphogenesis in Candida albicans, a major fungal pathogen of humans, consists of both budding and the formation of hyphae. The latter is thought to be related to the pathogenesis and invasiveness of C. albicans. We have isolated and characterized C. albicans homologs of the S. cerevisiae CDC3 and CDC10 genes. Both C. albicans genes are capable of complementing defects in the respective S. cerevisiae genes. RNA analysis of one of the genes suggests that it is a regulated gene, with higher overall expression levels during the hyphal phase than in the yeast phase. Not surprisingly, DNA sequence analysis reveals that the proteins share extensive homology at the amino acid level with their respective S. cerevisiae counterparts. Related genes are also found in other species of Candida and, more importantly, in filamentous fungi such as Aspergillus nidulans and Neurospora crassa. A database search revealed significant sequence similarity with two peptides, one from Drosophila and one from mouse, suggesting strong evolutionary conservation of function.     

Crown alterations induced by decline: a study of relationships between growth rate and crown morphology in beech (Fagus sylvatica L.)

One of the first symptoms expressed by declining trees is reduced growth in stem diameter and length increment. The possibility of a relationship between length increment and crown thinning in beech (Fagus sylvatica L.) was investigated by developing a computer model to simulate first order branching patterns of the apical 2 m of monopodially branching beech trees, 70–100 years old, for a range of length increment rates. The model was based on values for branching angle, main axis and branch length increment, number of branches produced per year and branch mortality rates for six healthy and declining trees. Shoot growth rates in the apical 2 m of the sample trees ranged from about 5 cm/year (decline class 3) to 43 cm/ year (healthy). Simulations of branching patterns in the apical 2 m of trees growing at different rates indicated that, when growth rate exceeded about 20 cm/year, total first order branch length and area explored were independent of growth rate. When growth rates fell below this value there was a reduction in total area explored and first order branch length due primarily to the formation of fewer branches. More acute branching angles contributed to a reduction in the area explored. Growth rate-related crown thinning could increase the risk of bark necrosis and secondary pathogen infection during dry and/or hot spells.     

The anatomical relations of the ductus vomeronasalis and the occurrence of taste buds in the papilla palatina of Nycticebus coucang (primates, prosimiae) with remarks on strepsirrhinism.

Nycticebus coucang is typically strepsirrhine. This condition is basically the same in all prosimians except Tarsius. The rhinarium shows a labial part; the marked furrow in its median plane clefts the margin of the upper lip. The latter is attached to the gum between the median incisors by means of paired folds (not corresponding to a frenulum labii superioris). The labial cleft is continued in the sulcus papillae palatinae. The ductus vomeronasalis opens into the ductus nasoplatinus which, in turn, enters the aboral part of the sulcus palatinus. Thus strepsirrhinism provides, occasionally, an open communication of the olfactory systems (nose, vomeronasal organ) with the environment in front of the rhinarium. Strepsirrhine primates possess an internarium very similar to the one of platyrrhine monkeys. The shape of the nostrils is not characteristics for strepsirrhinism. A split-lip condition is likely ancestral to the complete lip condition, since it is found in several stems of mammals, especially in archaic forms. Strepsirrhinism, such as in lemuroid prosimians, is probably just one case of the primitive split-lip condition. Therefore, a median furrow in the external hairy skin of the upper lip, found in some platyrrhine monkeys, could be a rudiment of a cleft, indicating that a kind of a split lip condition was ancestral to the undivided lips of platyrrhine monkeys. Taste buds occur in the epithelium of the lateral surface of the papilla palatina of Nycticebus. Other lorisid prosimians have not been studied in this respect. The taste buds test water soluble substances entering the sulcus either way. These substances may come from the environment entering the sulcus through the labial cleft.     

Hemopoiesis stimulating and radioprotective effects of carboxymethylglucan.

Carboxymethylglucan, a novel soluble derivative of beta-1,3-glucan, was found to enhance hemopoietic recovery in sublethally gamma-irradiated mice and to increase survival in lethally irradiated animals when given 24 hours prior to irradiation. Postirradiation treatment with carboxymethylglucan also induced favourable effects in terms of survival when used in combination with preirradiation cystamine administration.