Fully-adaptive algorithms for long-lived renaming

Long-lived renaming allows processes to repeatedly get distinct names from a small name space and release these names. This paper presents two long-lived renaming algorithms in which the name a process gets is bounded above by the number of processes currently occupying a name or performing one of these operations. The first algorithm is asynchronous, uses LL/SC objects, and has step complexity that is linear in the number of processes, c, currently getting or releasing a name. The second is synchronous, uses registers and counters, and has step complexity that is polylogarithmic in c. Both tolerate any number of process crashes.     

A8高速路公园

Koog aan de Zaan是阿姆斯特丹附近的个可爱的小村庄,坐落于Zaan河边。20世纪70年代早期,这里新建了条高速路。为了跨过河,A8高速下面由桥墩支撑。这条新路奇妙地穿过镇子,在城市肌理中形成了个粗暴的切口。具有讽刺意义的是,在这里形成了个教会和政府间的根本分离：高架路的一侧是一个小教堂,而另一侧则是原来的市政厅。桥墩大概有7米高。桥下的空间变得非常具有纪念性：成为一个延伸的教堂。     

On the question of an electrokinetic requirement for phospholipase C action

The phospholipase C of clostridium welchii (alpha toxin) has an absolute requirement for trace quantities of Ca2+. It attacks pure phosphatidylcholine particles (smectic mesophases) having a close-packed bilayer structure only when their surface zeta potential is made positive by the addition of certain divalent ions (e.g., Ca2+) to the aqueous phase or by the presence of low concentrations of long chain cations to the lipid. Alternatively, if the rotational freedom of individual phospholipid molecules is increased by the insertion of short n-alkanols (e.g., hexanol) into the bilayer or when a monolayer of the substrate at an air/water interface is expended, enzymic hydrolysis can occur without any requirement for a net postive charge on the surface.     

Platelet density and size: the interpretation of heterogeneity

Platelets have been separated according to buoyant density using a colloidal silica-polyvinylpyrrolidone system and subjected to electronic sizing. All density populations were found to be heterogeneous in size, the most dense platelets ranging from less than 3 fl to greater than 21 fl in both man and rat. Light platelet fractions contained no platelets greater than 13 fl in either species. Cohort labeling with [75Se]selenomethionine showed no indication of significant change in platelet buoyant density with ageing; greater specific activity found in young, dense platelets appears to be related to increased protein synthetic activity shown in vitro and likely to occur also in their precursor megakaryocytes. It is postulated that dense, intermediate and light platelets are released synchronously by the three different ploidy classes of megakaryocyte, that varying density indicates differing structural characteristics and presumably differences in function. The present findings do not deny the possibility that platelets decrease in size with ageing but if such occurs, it is not associated with a significant change in platelet buoyant density.