Regular Events Research Articles

The costs and benefits of boundary maintenance: stress, religion and culture among Jews in Britain.

This paper examines stress among two groups of orthodox Jews suggested to differ in the strength of the boundary of their religious group. Comparisons were made between the two groups, and with urban and rural groups studied by other researchers. Proportions of boundary-maintenance events (events whose threat had been caused or exacerbated by Jewishness) and of severe events, and proportions and rates of regular, irregular and disruptive events were examined. Boundary-maintenance events were higher among the more religiously orthodox affiliated group, and among whom religious observance was indeed reported to be higher. It was suggested that conditions of higher boundary maintenance would be associated with higher rates and proportions of regular events and with lower rates and proportions of irregular and disruptive events. Generally, the analyses supported this expectation. Boundary-maintenance events themselves were somewhat less severe, though not less likely to be irregular or disruptive than other events. Depression was shown to be unrelated to boundary-maintenance events and (surprisingly) unrelated to contextual threat when the effects of irregularity-disruption were controlled. Depression was, however, strongly related to irregular and disruptive events. The results are compared with those of related work, and suggest that the general lowering effect of affiliation to a religious group may be partly explained by the effects of boundary maintenance, which involves stress, but of a less depressogenic kind than the disruptive stress associated with conditions of low/no boundary maintenance. The findings have implications for understanding the relations between culture and mental disorder.

Finitely many-valued regular events in a direct product of semigroups

Finitely many-valued regular events in a direct product of semigroups

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<h3>SUMMARY</h3> Structural and transcriptional changes during early brain maturation follow fixed developmental programs defined by genetics. However, whether this is true for functional network activity remains unknown, primarily due to experimental inaccessibility of the initial stages of the living human brain. Here, we developed cortical organoids that spontaneously display periodic and regular oscillatory network events that are dependent on glutamatergic and GABAergic signaling. These nested oscillations exhibit cross-frequency coupling, proposed to coordinate neuronal computation and communication. As evidence of potential network maturation, oscillatory activity subsequently transitioned to more spatiotemporally irregular patterns, capturing features observed in preterm human electroencephalography (EEG). These results show that the development of structured network activity in the human neocortex may follow stable genetic programming, even in the absence of external or subcortical inputs. Our approach provides novel opportunities for investigating and manipulating the role of network activity in the developing human cortex. <h3>HIGHLIGHTS</h3> Early development of human functional neural networks and oscillatory activity can be modeled <i>in vitro</i>. Cortical organoids exhibit phase-amplitude coupling between delta oscillation (2 Hz) and high-frequency activity (100-400 Hz) during network-synchronous events. Differential role of glutamate and GABA in initiating and maintaining oscillatory network activity. Developmental impairment of MECP2-KO cortical organoids impacts the emergence of oscillatory activity. Cortical organoid network electrophysiological signatures correlate with human preterm neonatal EEG features. <h3>eTOC</h3> Brain oscillations are a candidate mechanism for how neural populations are temporally organized to instantiate cognition and behavior. Cortical organoids initially exhibit periodic and highly regular nested oscillatory network events that eventually transition to more spatiotemporally complex activity, capturing features of late-stage preterm infant electroencephalography. Functional neural circuitry in cortical organoids exhibits emergence and development of oscillatory network dynamics similar to those found in the developing human brain.

Synoptic forcing of wind and temperature in a large cirque 300 km from the coast of East Antarctica

Between 18 January 1988 and 3 June 1989, an automatic weather station recorded 13 different weather parameters every 3 h on a blue-ice area located in Scharffenbergbotnen, a large cirque in central Heimefrontfjella 300 km from the Weddell Sea coast. The first part of the paper reports on annual and monthly data regarding air temperature, air pressure, wind speed and wind direction, and a comparison is also made with corresponding data from the Neumayer and Halley stations. The second part deals mainly with winter (i.e. April–September) conditions in Scharffenbergbotnen. They seem, at least during 1988–89, to have been characterized by a large-scale (30–40 days) and, superimposed on the large-scale, a small-scale (3–4 days) co-variation of air temperature, air pressure and wind speed. The large-scale variation was earlier found to be synoptically forced. This paper shows that synoptic forcing exists also on smaller time scales. Pools of cold, stagnant air are regularly formed in the cirque only to be blown away by katabatic winds triggered by small variations in the synoptic pressure field. When this happens the air temperature increases by more than 20°C and the wind direction swings from east towards south-east. When low pressures dominate in the eastern part of the Weddell Sea, the katabatic winds become very strong, but weaker wind pulses also take place when the synoptic pressure gradient is directed towards the north-east. It therefore seems as if these very regular katabatic events are forced both by synoptic-scale pressure gradients and gradients due to the sloped inversion.

Multiple quantum phase slips in superfluid4He

Phase slips by 2π in the critical flow of superfluid 4He through an orifice have been known to exist for some time. Besides these small, regular events, large and precipitous drops of the velocity which may cause up to a full collapse of the flow through the orifice have been observed by a number of authors. We have found that collapses are robust and repeatable features during the same cool-down and correspond to events involving n quantized vortices. They depend on temperature, pressure, 3He content and resonator drive level. At a given pressure, their appearance is governed solely by the magnitude of the superfluid velocity vs.

Rewriting extended regular expressions

We consider an extended algebra of regular events (languages) with intersection besides the usual operations. This algebra has the structure of a distributive lattice with monotonic operations; the latter property is crucial for some applications. We give a new complete Horn-equational axiomatization of the algebra and develop some term-rewriting techniques for constructing logical inferences of valid equations.

Rewriting extended regular expressions

We consider an extended algebra of regular events (languages) with intersection besides the usual operations. This algebra has the structure of a distributive lattice with monotonic operations; the latter property is crucial for some applications. We give a new complete Horn-equational axiomatization of the algebra and develop some term-rewriting techniques for constructing logical inferences of valid equations.

Mortality of shallow reef corals in the western Arabian Gulf following aerial exposure in winter

Aerial exposure of patch reef corals occurred in Tarut Bay, western Arabian Gulf, (Saudi Arabia) between December 1991 and May 1992, and coincided with extreme low spring tides (below the predicted lowest astronomical tide-LAT). Colonies of Acropora and Stylophora occurring at the highest levels on the tops of patch reef platforms were most affected by the low tides. Corals fully exposed to air suffered total mortality, whereas those not fully exposed suffered tissue damage to their upper parts. Exposure occurred during winter months when air and water temperatures are at their lowest in the gulf. Coupling of extremely low spring tides with wind-induced negative surges (below LAT) are not regular events but are not infrequent. Cold temperatures and exposure may act in concert to produce disproportionate mortalities of reef flat corals in the shallow coastal areas of eastern Saudi Arabia. It is highly unlikely that the Gulf War oil spill played any role in the observed damage to reef corals in the Gulf in 1992.

A Completeness Theorem for Kleene Algebras and the Algebra of Regular Events

We give a finitary axiomatization of the algebra of regular events involving only equations and equational implications. Unlike Salomaa′s axiomatizations, the axiomatization given here is sound for all interpretations over Kleene algebras.

Difference-metric Viterbi decoding of multilevel class-IV partial-response signals

The paper describes the decoding of unconstrained L-ary signals (L/spl ges/2) transmitted over a noisy partial-response channel with transfer function 1-D/sup 2/. Signals received at even and odd sampling times are independently decoded in a pipeline fashion. After stating the known results for full-state maximum-likelihood sequence decoding, a 2-state decoding algorithm is introduced in which the difference between the metrics of the retained two most-likely states is iteratively computed. An analysis of its error-event probability shows that two types of error events are most likely, regular free-distance events and induced free-distance events. The latter cause only a rather small degradation of error performance compared to full-state decoding. In addition, the symbol-error probability for modulo-L encoded user symbols and decoding with finite decoding delay is computed. The 2-state decoder can be realized for arbitrary values of L with low hardware complexity.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Rewriting Extended Regular Expressions

We consider an extended algebra of regular events (languages) with intersection besides the usual operations. This algebra has the structure of a distributive lattice with monotonic operations; the latter property is crucial for some applications. We give a new complete Horn equational axiomatization of the algebra and develop some term-rewriting techniques for constructing logical inferences of valid equations.

Year Book For Traditional Music Edited by Anca Giurchescu, Adrienne Kaeppler, and Lisbet Torp Volume 23 published by the International Council for Traditional Music (ICTM), a founding member organisation of the International Music Council under the auspices of the United Nations Educational Scientific and Cultural Organisation (UNESCO), Department of Music, Columbia University, New York, NY 10027, 1991, $15.

the years, however, its focus changed, moving with the times and the developments in both ethnomusicology and the anthropology of human movement (the validity of concepts such as 'folk', 'ethnic', and 'tradition', for example, were questioned by scholars) and it has become probably one of the most encompassing organization dealing with music and dance in a worldwide perspective (its membership covers over 60 countries and the list of members in the 1991 Directory filled 64 pages!). Every other year it organises a world conference (this year it was held in Berlin, June 16-22). In addition, regional committees and specialized study groups hold regular events in between (the UK Chapter, for example held a conference at the University of London, Goldsmith College, on 5 December 1992, looking at the relationships between dance and music). Although in its publications the emphasis is still on forms outside the Western theatrical scene, articles such as Bruno Nettl's 'Mozart and the ethnomusicological study of Western culture (an essay in four movements)' (1989) are also appearing, and one paper, by Robert Coleridge, at the Goldsmith's conference last December, for example, looked at the use of music by Western theatrical choreographers. The size of the orga-

Variability of dayside convection and motions of the cusp/cleft aurora

We present measurements of the ionospheric plasma flow over the range of invariant latitudes 71–76°, observed at 10‐second resolution using both the EISCAT radars, with simultaneous observations of the 630 nm cusp/cleft aurora made by a meridian‐scanning photometer at Ny Ålesund, Svalbard. A major increase in the trans‐auroral voltage from 5 to 40 kV (associated with sunward convection in the early afternoon sector) is found to follow a southward motion of the aurora and coincide with the onset of regular transient auroral breakup events. It is shown that these observations are consistent with recent theoretical work on how ionospheric flows are excited by time‐dependent reconnection at the dayside magnetopause.

Les saisons des congrès internationaux : Le cas des villes européennes

Céline Rosenblat, Seasons and international conferences The choice of smaller cities for holding conferences is more directly linked to seasons than that of larger cities, where such conferences are regular events.

Zidovudine-induced restoration of cell-mediated immunity to mycobacteria in immunodeficient HIV-infected patients.

To describe a localized form of Mycobacterium avium intracellulare (MAI) infection occurring concurrently with the restoration of cutaneous delayed-type hypersensitivity (DTH) responses to mycobacterial antigens after commencement of zidovudine therapy in immunodeficient HIV-infected patients. The first 108 Western Australian patients with a CD4+ T-cell count of < 200 x 10(6)/l and/or symptomatic disease to be given zidovudine (ZDV), of whom 72 had adequate DTH data. DTH responses to seven antigens were measured by the 'Multitest' method before and on at least two occasions during the 6 months after commencing ZDV. All patients were reviewed at regular intervals and clinical events recorded. Of the 64 patients who were anergic to tuberculin before commencing ZDV, 27 (42%) developed a DTH response to tuberculin after ZDV. Four of the nine patients with a 'Multitest' tuberculin response of > or = 8 mm and one patient who developed a positive Mantoux test to M. avium purified protein derivative developed an illness characterized by localized MAI infection, lymphadenopathy and/or severe fevers after 1-2 weeks. The development of localized MAI infection and/or fevers shortly after commencing ZDV in immunodeficient HIV-infected patients may reflect restoration of cellular immunity to mycobacterial antigens in some patients rather than early failure of therapy or hypersensitivity to ZDV.

Tempo sensitivity in auditory sequences

Differential thresholds for 11 tempi (ranging from 100 to 1500 ms between successive onsets) were measured for four subjects using a 2AFC paradigm. In a first experiment, the number of events in the sequence was varied to test whether sensitivity is greater in regularsequences than in simple duration discrimination tasks (only two events). Relative jnd were: (1) optimal at intermediate tempi (as low as 1.5% in the range between 300–800 ms), and (2) decreased as the number of events increased (2 events=6%, 3 events=4%, 5 events=3.2%, 7 events=3%). A second experiment tested whether this higher sensitivity was due to the fact that the sequences were regular or not by measuring differential tempo thresholds for irregular sequences of five events. Globally, sensitivity for these irregular sequences was of an intermediate level between that of the simple duration task and the sequences with five regular events. The results are discussed in terms of the hypothesized ‘‘regularity detectors.’’

Global unpredictability in nonlinear dynamics: capture, dispersal and the indeterminate bifurcations

This paper surveys in general terms some of the problems of predictability that arise in regular and chaotic dynamics. These relate to attractors, basins and bifurcations, and a capture-dispersal diagram is introduced to assess relative degrees of global unpredictability. Indeterminate bifurcations emerge as the most severe generators of unpredictability, and some new examples involving both regular and chaotic events are presented as illustrations.

Predictive responses in Parkinson's disease: manual keypresses and saccadic eye movements to regular stimulus events.

In a coincidence timing task, Parkinsonian patients and a control group were instructed to synchronize a keypress with the onset of a visual signal which had been preceded by a regular train of warning signals. Although the Parkinsonian group had previously exhibited slower reactions in a conventional simple reaction-time task, they were able to generate predictive responses that fell as close to the target onset as the controls' but showed greater variability. In a second experiment, Parkinsonian patients and controls made saccadic eye movements to a visual target that stepped at regular intervals between two fixed locations. After a few trials all the subjects tended to make predictive saccades that were initiated before the target excursion. However, the Parkinsonian group were slower to develop this strategy and when they did their saccades became considerably more hypometric than those of the controls. Both groups were able to maintain predictive responding even when the visual target disappeared and responses were paced by a buzzer. We concluded that Parkinsonian patients are capable of initiating predictive responses of the eye and the hand, at least in some circumstances, but such responses tend to be inaccurate in execution. This, in turn, may dispose the Parkinsonian patient against predictive movement.

Regular and irregular characteristics of ovulation and the interovulatory interval in mares

Characteristics of regular and irregular ovarian events were studied by daily ultrasound examination in 102 non-bred mares. The mean diameter of the prevoluatory follicle on the day before a single ovulation was significantly higher in April (46 mm) and May (48 mm) than in July (40 mm). Diameter was also significantly different among single (44 mm), double unilateral (35 mm), and double bilateral (40 mm) preovulatory follicles. The incidence of apparent anovulation within the ovulatory season was 4.7%. All apparent anovulations involved filling of the follicle with blood (hemorrhagic follicles). The incidence of diestrous ovulations was 4%. Prolonged interovulatory intervals occurred in 6 of 69 (9%) intervals. In 2 intervals (30 and 33 days), both the luteal and follicular phases were prolonged and no structural ovarian or uterine irregularities were detected. Three prolonged intervals (34, 41, and 49 days) were associated with hemorrhagic follicles and 1 was associated with a late diestrous ovulation (47 days). The condition known as spontaneous persistence of the corpus luteum, which is thought to be common in nonpregnant mares, was not detected in any of 69 interovulatory intervals.

The centroid of tree crowns as an indicator of abiotic processes in a balsam fir wave forest

Wave forests are rare and were previously known only in high altitude Abiesbalsamea forests in northeastern U.S.A. and in subalpine A. veitchii – A. mariesii forests in Japan. Wave forests have been discovered at several locations in Newfoundland, including a very large and unique wave forest extending over 100–150 km2 on the coastal plain of northwestern Newfoundland. The wave fronts, characterized by dead tree strips, are mostly sinusoidal with an axis aligned in the direction of the prevailing wind, are spaced 100–150 m apart, and move in 55-year cycles. Crest-shaped wave fronts are concave on the windward side, occur as random events, and leave a trailing edge to the right of the prevailing wind that becomes a sinusoidal wave front. Two types of wave cycles, uniformcycle and brokencycle, have been identified as regular and random events, respectively. This paper reports the initial results of a detailed study on the impact of wind on the dynamics of a wave forest and concentrates on the centroid as a measure of crown asymmetry useful for distinguishing between purely biotic (mainly competition) and abiotic (mainly wind) processes as the primary cause of crown asymmetry. The development of wave forests at Spirity Cove is described based on the hypothesis that longitudinal helical roll vortices are primarily responsible for their formation.