SummaryEukaryotic cells from fungal hyphae to neurites that grow by polarized extension must coordinate cell growth and cell orientation to enable them to exhibit growth tropisms and to respond to relevant environmental cues. Such cells generally maintain a tip-high Ca2+ cytoplasmic gradient, which is correlated with their ability to exhibit polarized tip growth and to respond to growth-directing extracellular signals [1–5]. In yeast and other fungi, the polarisome, exocyst, Arp2/3, and Spitzenkörper protein complexes collectively orchestrate tip growth and cell polarity, but it is not clear whether these molecular complexes also regulate cell orientation or whether they are influenced by cytoplasmic Ca2+ gradients. Hyphae of the human pathogenic fungus Candida albicans reorient their growth axis in response to underlying surface topography (thigmotropism) [6] and imposed electric fields (galvanotropism) [7]. The establishment and maintenance of directional growth in relation to these environmental cues was Ca2+ dependent. Tropisms were attenuated in media containing low Ca2+, or calcium-channel blockers, and in mutants where calcium channels or elements of the calcium signaling pathway were deleted. Therefore galvanotropism and thigmotropism may both be mediated by localized Ca2+ influx at sites of polarized growth via Ca2+ channels that are activated by appropriate environmental signals.

Phenotypic variability in pathogenic fungi has long been correlated with virulence, but specific genetic and molecular mechanisms are only recently being unraveled. Fungal morphogenesis, reflecting the expression of several regulated genes, and the capacity of the rising forms or phases to cause disease has been focused on at the XIVth Congress of the International Society for Human and Animal Mycology. Three experimental models of pathogenic fungi have been discussed. In Cryptococcus neoformans, phenotypic variability or switching represents controlled and programmed changes rather than random mutations. Evaluated phenotypic traits were the capsular polysaccharide, cell and colony morphology and virulence. In the dimorphic Paracoccidioides brasiliensis, the serine-thiol proteinase from the yeast phase cleaves the main components of the basal membrane, thus being potentially relevant in fungal dissemination. In Candida albicans, relationships between adhesion proteins and those of lymphocytes and neutrophils are related to fungal pathogenicity. Regulation of the directional growth of hyphae and its tropic responses are correlated with the invasive potential of C. albicans.

Background/Objectives: Childhood obesity has increased enormously. Several lifestyle factors have been implicated, including decreased physical activity, partially involving a decline in active travel to school. We aimed to establish the association between school transport mode and physical activity levels of primary 6 and 7 children (aged 10 to 12). Secondary outcomes were body mass index standard deviation scores, blood pressure levels and lung function. Subjects/Methods: A cross sectional study was conducted with a total number of 432 children from three primary schools in North East Scotland. Actigraph accelerometers were used to provide objective measures of physical activity. Ninety-two children in primary 6 and 90 children in primary 7 (40 in common) had adequate data. Modes of transport to school were assessed by a questionnaire. Twohundred and 17 children in primary 6 and 165 in primary 7 returned adequate questionnaires. Children who used active transport modes for greater than 70% of their journeys to school over the week were coded as active travellers and less than 30% were coded as passive travellers. All children also had height, weight, blood pressure levels and lung function measured. Results: Children who lived further away from school, and in more expensive properties were more likely to travel passively to school. Actively commuting children (70% walking) had significantly higher activity levels than passive commuters during the 30 minutes that encompassed their journey to and from