The Role of Calcium in the Regulation of Apoptosis

The recognition that apoptosis is regulated by an evolutionarily conserved set of polypeptides from the nematode Caenorhabditis elegans to humans suggests that a conserved set of biochemical mechanism(s) may also be involved in the response. Early evidence suggested that the endogenous endonuclease implicated in apoptosis in most model systems is Ca2+ -dependent, and subsequent work from a number of independent laboratories suggests that alterations in cytosolic Ca2+ homeostasis are one of the conserved biochemical pathways regulating the response. Molecular targets for Ca2+ are now being identified and include signal transduction intermediates, endonuclease(s) and proteases, and the enzymes involved in the maintenance of phospholipid asymmetry in the plasma membrane. Furthermore, interesting preliminary work suggests that BCL-2 suppresses apoptosis via a mechanism that is linked to intracellular Ca2+ compartmentalization, and it appears that Ca2 + alterations in some examples of apoptosis occur as the result of changes within the mitochondria. This review will summarize what is known about the role of Ca2+ in the regulation of apoptosis and discuss how Ca2+ might interact with some of the other biochemical signals implicated in cell death

Advances In Atomic, Molecular, and Optical Physics

The use of rare gas matrices for the detection of a variety of low-energy metastable species, particularly those from atoms with an np4 outer electron configuration, is discussed in detail. The historical development of the detector is outlined and its performance as a function of rare gas, matrix temperature, and metastable species is discussed. Examples of its use are given for electron impact dissociation of a wide variety of oxygen and sulfur containing targets

Selective detection of singlet gerade metastable states of N-2

Metastable N-2 molecules produced by electron impact on N2 are detected using a unique solid nitrogen matrix detector. The time-of-flight system is shown to be selectively sensitive to a(1)Pi(g) and (1)Sigma(+)(g) or (1)Gamma(g) metastable species. The latter species had been identified theoretically previously but was detected experimentally for the first time in the present investigation. Their identification and excitation as a function of electron energy from threshold to 300 eV are presented. Comparison is made with the data obtained by other techniques. Published by AIP Publishing

Use of solid N2 surfaces in metastable particle detection

A novel detector is described in which solid nitrogen at 17 K is used as the most significant element. Metastable particles impinge on this element and immediately transfer their internal energy to the solid nitrogen producing photons, via excimer formation or otherwise, whose wavelength depends on the metastable being detected and the energy transfer process. The performance of the instrument for the detection of atomic oxygen and molecular nitrogen metastables is discussed

Changes in Children’s Speech and Language Difficulties from Age Five to Nine: An Irish National, Longitudinal Study

In many countries, information on the prevalence of persistent speech and language disorders in early childhood is sparse due to the lack of nationally representative samples and longitudinal studies. Secondary analysis of data collected on over 7500 Irish children at ages 5 and 9 years, found that the prevalence of speech and language difficulties reported by the primary caregivers of Irish children decreased from one in six at age 5 to one in 12 at age 9. However, one in 20 children were reported to have difficulties at both ages. Regression analysis compared children with difficulties at both age 5 and age 9 to those who had been reported to have them at age 5 but no longer had such difficulties at age 9. Children with speech and language difficulties at both age 5 and age 9 were more likely to have two or more developmental impairments as well as current or past hearing impairments. Teachers and parents also reported a greater number of social-emotional difficulties. Family characteristics did not differ significantly across the two groupings. At best, up to one third of the children at ages 5 and 9 with speech and language difficulties had two or more contacts with a speech and language therapists in the preceding 12 month period. Increased support to these children, their parents and teachers would seem to be warranted

N (2P) production in electron-N2 collisions

A unique detector which is selectively sensitive to low energy metastable atoms, has been used to study the production of ground state N (2P) atoms following collisions of low energy (0-200 eV) electrons with molecular nitrogen. TOF techniques have revealed the existence of at least two distinct mechanisms yielding this dissociation product. Released kinetic energies in the dissociation have allowed positioning of the parent molecular states in the Franck-Condon region. This has allowed probable parent states, such as B\u27 3Σu¯, b\u27 1Σu+ and C\u27 3Πu, to be identified making use of recent theoretical calculations. Both direct and predissociation processes are shown to be involved