Restricted Interval Research Articles

Classes of graphs with restricted interval models

We introduce q-proper interval graphs as interval graphs with interval models in which no interval is properly contained in more than q other intervals, and also provide a forbidden induced subgraph characterization of this class of graphs. We initiate a graph-theoretic study of subgraphs of q-proper interval graphs with maximum clique size k+1 and give an equivalent characterization of these graphs by restricted path-decomposition. By allowing the parameter q to vary from 0 to k, we obtain a nested hierarchy of graph families, from graphs of bandwidth at most k to graphs of pathwidth at most k. Allowing both parameters to vary, we have an infinite lattice of graph classes ordered by containment.

Experimental properties of gluon and quark jets from a point source

Gluon jets are identified in hadronic Z $^0$ decays as all the particles in a hemisphere opposite to a hemisphere containing two tagged quark jets. Gluon jets defined in this manner are equivalent to gluon jets produced from a color singlet point source and thus correspond to the definition employed for most theoretical calculations. In a separate stage of the analysis, we select quark jets in a manner to correspond to calculations, as the particles in hemispheres of flavor tagged light quark (uds) events. We present the distributions of rapidity, scaled energy, the logarithm of the momentum, and transverse momentum with respect to the jet axes, for charged particles in these gluon and quark jets. We also examine the charged particle multiplicity distributions of the jets in restricted intervals of rapidity. For soft particles at large $p_{\rm T}$ , we observe the charged particle multiplicity ratio of gluon to quark jets to be $2.29\pm0.09\,{\mathrm{(stat.)}} \pm0.15\,{\mathrm{(syst.)}}$ , in agreement with the prediction that this ratio should approximately equal the ratio of QCD color factors, ${\rm C_A/C_F}= 2.25$ . The intervals used to define soft particles and large $p_{\rm T}$ for this result, $p < 4$ GeV/ $c$ and $0.8 < p_{\rm T}< 3.0$ GeV/ $c$ , are motivated by the predictions of the Herwig Monte Carlo multihadronic event generator. Additionally, our gluon jet data allow a sensitive test of the phenomenon of non-leading QCD terms known as color reconnection. We test the model of color reconnection implemented in the Ariadne Monte Carlo multihadronic event generator and find it to be disfavored by our data.

Multifractal multiplicity distribution in and interactions from nonlinear Markov process

The multifractal negative binomial distribution derived from the nonlinear Markov process has been used to explain the multiplicity distributions in high-energy and interactions. The analysis aims at explaining the shoulder structure and high-multiplicity tail of these distributions and determining the strength of influence of nonlinearity in the restricted phase-space intervals which is related to the degree of multifractality.

Mixture designs for constrained components in orthogonal blocks

It is often the case in mixture experiments that some of the ingredients, such as additives or flavourings, are included with proportions constrained to lie in a restricted interval, while the majority of the mixture is made up of a particular ingredient used as a filler. The experimental region in such cases is restricted to a parallelepiped in or near one corner of the full simplex region. In this paper, orthogonally blocked designs with two experimental blends on each edge of the constrained region are considered for mixture experiments with three and four ingredients. The optimal symmetric orthogonally blocked designs within this class are determined and it is shown that even better designs are obtained for the asymmetric situation, in which some experimental blends are taken at the vertices of the experimental region. Some examples are given to show how these ideas may be extended to identify good designs in three and four blocks. Finally, an example is included to illustrate how to overcome the problems of collinearity that sometimes occur when fitting quadratic models to experimental data from mixture experiments in which some of the ingredient proportions are restricted to small values.

Fossil fuel biomarkers in plant waxes as pollution parameters

Hopane and sterane derivatives typical of highly mature sedimentary organic matter, e.g. petroleum, have been identified in several plant species growing near Nancy, France. Analyses of plant waxes by gas chromatography–mass spectrometry over a restricted mass interval ( m/z 185–195) allows definition of pollution parameters based on the relative concentration of fossil hopanes versus modern plant n-alkanes. Indeed, such parameters are higher for Pinus nigra growing along a high traffic highway than for Pinus nigra growing in a less polluted suburb area. Molecular pollution parameters based on fossil molecules are thus promising tools for measuring the extent of fossil fuel input into plant and food.

The Farmworker Health and Safety Institute (FHSI)

ABSTRACT In general, few people know about pesticide poisoning, understand the concept of restricted entry interval, or have received any training on how to protect themselves from pesticides. Symptoms related to pesticide poisoning are easily confused with those for other illnesses, often resulting in health care providers and farmworkers alike not always recognizing the negative health affects related to pesticide exposure. The Farmworker Health and Safety Institute has developed a training program that makes farmworkers aware of the hazards to which they are exposed to on a daily basis as well as give them skills to address these hazards. The sessions are conducted in English, Spanish, and Haitian Creole and training materials are prepared in each of the three languages. The program enables farmworkers to develop advocacy skills in order to directly address problems in the workplace and community by influencing federal and state agencies who are responsible for enforcing these regulations.

Timing and duration of the Last Interglacial: evidence for a restricted interval of widespread coral reef growth

We report new mass spectrometric U-series ages for eight Last Interglacial fossil reefs along the continental margin of Western Australia. Corals were selected in growth position from localities that are characterized by apparently low levels of diagenesis and relative tectonic stability so that the fossil reefs provide critical information on Last Interglacial sea-levels without requiring corrections for tectonic movements. In addition, we have improved the constraint on the timing of onset of reef growth by recovering drill core coral from the base of the reefs. Uranium and thorium isotopes were measured with high levels of precision, leading to improvements in age resolution and allowing samples which have undergone diagenetic exchange of uranium and thorium to be more easily identified and discarded. These data supplement our previous results for Rottnest Island and Leander Point, leading to more than seventy mass spectrometric U-series ages from which constraints can be placed on the timing, duration and character of the Last Interglacial sea-level highstand. Reliable ages show that reef growth started contemporaneously at 128 ± 1 ka along the entire Western Australian coastline, while relative sea-levels were at least 3 m above the present level. Because Western Australia is located far from the former Penultimate Glacial Maximum ice sheets and are not significantly effected by glacial unloading, these data constrain the timing of onset of the Last Interglacial period to 128 ± 1 ka, assuming reef growth started soon after sea-level approached interglacial levels. A unique regressive reef sequence at Mangrove Bay constrains the timing of termination of the Last Interglacial period to 116 ± 1 ka. The major episode of reef building, however, both globally and locally along the Western Australian coast, is restricted to a very narrow interval occurring from ∼128 ka and ∼121 ka, suggesting that global ocean surface temperatures were warm and/or sea-levels were stable enough to allow prolific reef growth only during the earlier part of the Last Interglacial.

Period-Dependent Oscillatory Free-Run in the Locomotor Activity Rhythm of the Field Mouse Mus booduga Under Skeleton Photoperiodic Regimes

The entrainment behaviour of the circadian rhythm of locomotor activity in the field mouse Mus booduga was studied in order to evaluate the role of the animals' free-running period (τ) and the duration of skeleton photoperiods in determining entrainment of animals with τ values beyond and close to the “limits of entrainment”. We predicted that animals with τ lesser than the lower “limit of entrainment” would entrain only to short skeleton photoperiods (≤ 6 h) and not to longer skeleton photoperiods. Experimental animals (n = 25) were entrained to light/dark (LD) 12:12 h schedule, and then subjected to various skeleton photoperiods in which the duration of one of the two intervals of darkness was successively reduced while holding the zeitgeber period (T) constant. Some animals (n = 9) entrained to long as well as short photoperiods, whereas others (n = 5) entrained only to extremely short skeleton photoperiods of 6 h or less. The mean τ of the animals entraining to all photoperiods (23.78 ± 0.22 h) was significantly greater than that of the animals that entrained only to very short skeleton photoperiods (22.43 ± 0.41 h) (t df 12 = 5.3, p < 0.001). We also selected a few animals (n = 11) with average τ value of 23.13 ± 0.38 h and studied them under several skeleton photoperiods. To our surprise the animals which were subjected to restricted dark intervals invariably underwent “phase-jump” assuming the longer dark interval as “subjective night”. We suggest that the observed variation in entrainment behaviour might be due to the variation seen among individual animals in τ and the shape of their PRC. These results support the view that the duration of the skeleton photoperiod and the τ of an individual animal interact to determine its entrainment, and underscore the relevance of inter-individual variation in circadian organisation to studies of circadian rhythms.

Applicability of the High Field Model: A Preliminary Numerical Study

In a companion presentation, we have discussed the theory of a mesoscopic/ macroscopic model, which can be viewed as an augmented drift-diffusion model. Here, we describe how that model is used. The device we consider for this presentation is the one dimensional GaAs n+−n−n+ structure of length 0.8μm. First, a full Hydro- Dynamic (HD) model, proven reliable when compared with Monte Carlo simulations, is used to simulate the device via the ENO finite difference method. As applied to the full device, the new model is not necessarily superior to traditional Drift-Diffusion (DD). Indeed, when we plot the quantity η= μ0E/kT0/m, where μ0 is the mobility constant and E=−ϕ′ is the electric field, we verify that the high field assumption η › 1, required for the high field model, is satisfied only in an interval given approximately by [0.2, 0.5]. When we run both the DD model and the new high field model in this restricted interval, with boundary conditions of concentration n and potential ϕ provided by the HD results, we demonstrate that the new model outperforms the DD model. This indicates that the high field and DD models should be used only in parts of the device, connected by a transition kinetic regime. This will be a domain decomposition issue involving interface conditions and adequate numerical methods.

U-Pb zircon age for the Umkondo dolerites, eastern Zimbabwe: 1.1 Ga large igneous province in southern Africa–East Antarctica and possible Rodinia correlations

We report a U-Pb zircon age of 1105 ± 2 Ma for the extensive Umkondo dolerites in eastern Zimbabwe, which are part of a large igneous province that can be traced over much of southern Africa and originally contiguous parts of East Antarctica. Other members of the province include widespread tholeiitic intrusions in Botswana and South Africa, bimodal volcanic rocks in Botswana and Namibia, and dolerites and flood basalts in Dronning Maud Land, Antarctica. Available data indicate that substantial parts of the province were emplaced in a restricted interval at ca. 1.1 Ga and originated from a large-scale mantle thermal anomaly inboard of a coeval continental-margin orogen. Striking similarities in age and tectonic setting between the Umkondo igneous province and widespread 1.1 Ga within-plate magmatism in Laurentia are consistent with reconstructions of the early Neoproterozoic Rodinia supercontinent that place southern Africa and Dronning Maud Land off the southern tip of Laurentia.

Multiparticle clusters and intermittent fluctuations

An approach for understanding the behaviour of multiplicity distributions in restricted phase-space intervals derived on the basis of global observables is proposed. We obtain a unifying connection between local multiparticle clusters and the scale-invariant, power-law behaviour of normalized factorial moments. The model can be used to describe multiparticle processes in terms of a decomposition of the observed intermittent signal into contributions from clusters with varying numbers of particles.

Baryon emission at target rapidities inSi+Al,Cu,Aucollisions at14.6AGeV/candAu+Aucollisions at11.7AGeV/c

We report measurements of proton emission at target rapidities for minimum bias and central collisions of 14.6AGeV/c {sup 28}Si with Al, Cu, and Au nuclei as well as minimum bias and central collisions of 11.7AGeV/c {sup 197}Au with Au nuclei. Results for deuteron emission are also reported for the Si+Au reaction. The spectra span the laboratory angular range of 50{degree}{le}{theta}{le}130{degree} and kinetic energy range of 40MeV{le}E{sub kin}{le}225MeV. Inverse slopes of proton spectra and proton dN/d{eta} values in the kinetic energy range 50MeV{le}E{sub kin}{le}110MeV are reported. The inverse slopes are 40{endash}80 MeV for the various systems, generally increasing with increasing pseudorapidity. The dN/d{eta} values for A+A collisions within the restricted kinetic energy interval are compared to those for protons from p+Au in the literature. All pseudorapidity distributions have very similar shapes. The experimental results have been compared to the predictions of the nucleon-nucleon collision models ARC and RQMD. The predictions made by these two models for the distribution of protons at target rapidities are very similar to each other. However, there are significant differences between the model predictions and the experimental results in the details of the spectral slopes and the proton yields for different trigger conditions. {copyright} {ital 1997} {italmore » The American Physical Society}« less

Phenomenological parametrization of the charged particle multiplicity distributions in restricted rapidity intervals in e+e− annihilation into hadrons and e+p scattering at HERA

It is shown that charged particle multiplicity distributions in restricted (pseudo)rapidity intervals in e + e − annihilation and in e + p scattering at HERA are quite well described by the modified negative binomial distribution and its simple extension.

Chapter 31 On the role of the cerebellum and basal ganglia in cognitive signal processing

Publisher Summary This chapter presents a cooperative control theory of how the cerebellum and basal ganglia might contribute to cognitive functions that are represented in the prefrontal cortex. The prefrontal cortex is a likely site for the formation of temporary representations—called working memories—of important events, contexts, and recalled experiences. Working memories are very important in higher cognitive functions such as attention, synthetic reasoning and planning, comprehension of situations, utilization of experience, and incorporation of verbal instructions for controlling behavior. In physiological terms, a working memory takes the form of sustained discharge in prefrontal neurons, which serves to store information temporarily, over a restricted time interval. A simple paradigm that is often used to elicit a working memory is illustrated in this chapter along with a schematic of the neural correlates that can be recorded from prefrontal neurons. The theory advanced in the chapter asserts that thought processes, such as the instantiation of a working memory, utilize modular signal processing operations in a manner analogous to modularity in voluntary movement control. According to this theory, cortical–basal ganglionic modules are specialized for the initiation of partial thoughts, ones that generally require subsequent elaboration and refinement.

Painted Containers: A New Method for Paclobutrazol Application

The effectiveness of two application methods of the growth regulator paclobutrazol on the growth of Chrysanthemum plants, Dendranthema ×grandiflora (Ramat) (cv. `Fina' and `Cream Dana') were compared. Plants were grown in containers with their interior covered by a mixture of flat latex paint and several concentrations of paclobutrazol (0, 5, 10, 20, 40, 80, 100, 150, 160, and 200 mg·L–1) or were treated with a soil drench of the growth regulator according to label recommendations (59 ml/container of paclobutrazol solution at 4 mg·L–1). Plants grown in containers with the paint–paclobutrazol mix at concentrations &gt;80 mg·L–1 were shorter than plants given the control and paint only treatments but taller than plants given the drench treatment. Increasing paclobutrazol concentrations in paint from 100 to 150 and 200 mg·L–1 did not produce proportionately shorter plants. Paint alone had no effect on growth and development. Plants subject to growth regulator treatments appeared greener than the control plants. None of the plants given treatments with paint with or without paclobutrazol showed any sign of phytotoxicity. These results suggest the possibility of a new application method for systemic chemicals with the potential of reducing or eliminating worker protection standard restricted entry intervals and reducing the release of chemicals to the environment. Chemical name used: beta-[(4-chlorophenyl)methyl]-α-(1,1-dimethyl)-1H-1,2,4,-triazole-1-ethanol (paclobutrazol).

Painted Containers: A New Method for Imidacloprid Application

The effectiveness of two methods of application of the insecticide imidacloprid in controlling 1) aphids (Brachycaudus helichrysi) on Chrysanthemum plants, Dendranthema ×grandiflora (Ramat) (cv. Nob Hill) and 2) whitefly (Bemisia argentifolii) on poinsettia, Euphorbia pulcherrima (Wild.) (cv. Freedom Red) were compared. Plants were grown in containers with their interior covered by a mixture of flat latex paint and several concentrations of imidacloprid (0, 10, 21, 42, and 88 mg·L–1), or treated with a granular application of the insecticide (1% a.i.) according to label recommendations. All imidacloprid treatments were effective in reducing aphid survival after 8 weeks. The two most effective treatments were: granular (1% a.i.) and 88 mg·L–1 with an average of 0.2 aphid per plant as opposed to 50.4 aphids per plant for the control. The 42-mg·L–1 treatment had an aphid survival rate 1.6 aphids per plant. All imidacloprid treatments were effective in reducing white fly larvae. The 42 and 88 mg·L–1 and the granular (1% a.i.) were equally effective in reducing larvae numbers in lower poinsettia leaves: 0.5, 1.9, 0.9 larvae/2.5 cm leaf disk, respectively, while the control treatment had 62.9. None of the plants given treatments with paint showed any sign of phytotoxicity. These results suggest the possibility of a new application method for systemic chemicals with the potential of reducing or eliminating Worker Protection Standard (WPS) Restricted Entry Intervals (REI) and reducing the release of chemicals to the environment. Chemical name used: 1-[(6-Chloro-3-pyrimidil)]-N-nitro-2-imidazolidinimine.

Overcoming Limitations of the Conventional Strain-Life Fatigue Damage Model

The strain-based approach to fatigue life prediction usually relies on the conventional strain-life equation which correlates the elastic and plastic strain to the life. The correlation is based on separate log-linear curve fits of the elastic and plastic components of the strain data versus the life. It is well known, however, that these linear relationships may be valid only within a specific interval of stress or strain. When material behavior approaches elastic-perfectly plastic, for instance, it is not uncommon for the test data to deviate from linearity at both very high and very low strains. For such materials a separate fit of each curve is likely to give material constants significantly inconsistent with the fit of the cyclic stress-strain curve, especially if a good local fit over a restricted interval is obtained. In this work, some of the errors that arise as a result of this inconsistency are described, and recommended methods are developed for treating these errors. Numerical concerns are also addressed, and sample results are included.

Measurements of the charged particle multiplicity distribution in restricted rapidity intervals

Charged particle multiplicity distributions have been measured with the ALEPH detector in restricted rapidity intervals |Y| ≤0.5, 1.0, 1.5, 2.0 along the thrust axis and also without restriction on rapidity. The distribution for the full range can be parametrized by a log-normal distribution. For smaller windows one finds a more complicated structure, which is understood to arise from perturbative effects. The negative-binomial distribution fails to describe the data both with and without the restriction on rapidity. The JETSET model is found to describe all aspects of the data while the width predicted by HERWIG is in significant disagreement.

Measurements of the charged particle multiplicity distribution in restricted rapidity intervals

Measurements of the charged particle multiplicity distribution in restricted rapidity intervals

Strongly enhanced incoherent‐scatter plasma lines in aurora

Observations of incoherent‐scatter plasma‐line intensities, measured in the E‐region with the European Incoherent Scatter UHF radar, during auroral precipitation, are presented. Intensities up to 200 times the thermal level were observed in a restricted frequency interval from 5.5 to 6.5 MHz. Intensities were lower at both higher and lower frequencies. The intensities are compared with quantitative estimates based on model suprathermal electron fluxes for the prevailing conditions. The minimum in suprathermal electron fluxes between 2 and 4 eV, which is caused by the excitation of vibrational levels in N2, is found to result in a minimum in expected plasma‐line damping and a maximum in intensity between 5.5 and 6.5 MHz, for the EISCAT UHF wavelength. Good agreement is found between the calculated and observed intensities.