Spherical collapse model in agegraphic dark energy cosmologies

Under the commonly used spherical collapse model, we study how dark energy affects the growth of large scale structures of the Universe in the context of agegraphic dark energy models. The dynamics of the spherical collapse of dark matter halos in nonlinear regimes is determined by the properties of the dark energy model. We show that the main parameters of the spherical collapse model are directly affected by the evolution of dark energy in the agegraphic dark energy models. We compute the spherical collapse quantities for different values of agegraphic model parameter $\alpha$ in two different scenarios: first, when dark energy does not exhibit fluctuations on cluster scales, and second, when dark energy inside the overdense region collapses similar to dark matter. Using the Sheth-Tormen and Reed mass functions, we investigate the abundance of dark matter halos in the framework of agegraphic dark energy cosmologies. The model parameter $\alpha$ is a crucial parameter in order to count the abundance of dark matter halos. Specifically, the present analysis suggests that the agegraphic dark energy model with bigger (smaller) value of $\alpha$ predicts less (more) virialized halos with respect to that of $\Lambda$CDM cosmology. We also show that in agegraphic dark energy models, the number of halos strongly depends on clustered or uniformed distributions of dark energy.Comment: 14 pages, 7 figures. Accepted in Physical Review

Effect of breakfast omission and consumption on energy intake and physical activity in adolescent girls: a randomised controlled trial

It is not known if breakfast consumption is an effective intervention for altering daily energy balance in adolescents when compared with breakfast omission. This study examined the acute effect of breakfast consumption and omission on free-living energy intake (EI) and physical activity (PA) in adolescent girls. Using an acute randomised crossover design, forty girls (age 13.3 ± 0.8 y, body mass index 21.5 ± 5.0 kg∙m-2) completed two, 3-day conditions in a randomised, counter-balanced order: no breakfast (NB) and standardised (~1962 kJ) breakfast (SB). Dietary intakes were assessed using food diaries combined with digital photographic records and PA was measured via accelerometry throughout each condition. Statistical analyses were completed using repeated measures analysis of variance. Post-breakfast EI was 483 ± 1309 kJ/d higher in NB vs. SB (P=0.025), but total daily EI was 1479 ± 1311 kJ/d higher in SB vs. NB (P<0.0005). Daily carbohydrate, fibre and protein intakes were higher in SB vs. NB (P<0.0005), whereas daily fat intake was not different (P=0.405). Effect sizes met the minimum important difference of ≥0.20 for all significant effects. Breakfast manipulation did not affect post-breakfast macronutrient intakes (P≥0.451) or time spent sedentary or in PA (P≥0.657). In this sample of adolescent girls, breakfast omission increased post-breakfast free-living EI, but total daily EI was greater when a standardised breakfast was consumed. We found no evidence that breakfast consumption induces compensatory changes in PA. Further experimental research is required to determine the effects of extended periods of breakfast manipulation in young people

Abundance of small individuals influences the effectiveness of processing techniques for deep-sea nematodes

Nematodes are the most abundant metazoans of deep-sea benthic communities, but knowledge of their distribution is limited relative to larger organisms. Whilst some aspects of nematode processing techniques, such as extraction, have been extensively studied, other key elements have attracted little attention. We compared the effect of (1) mesh size (63, 45, and 32 μm) on estimates of nematode abundance, biomass, and body size, and (2) microscope magnification (50 and 100×) on estimates of nematode abundance at bathyal sites (250-3100 m water depth) on the Challenger Plateau and Chatham Rise, south-west Pacific Ocean. Variation in the effectiveness of these techniques was assessed in relation to nematode body size and environmental parameters (water depth, sediment organic matter content, %silt/clay, and chloroplastic pigments). The 63-μm mesh retained a relatively low proportion of total nematode abundance (mean ±SD = 55 ±9%), but most of nematode biomass (90 ± 4%). The proportion of nematode abundance retained on the 45-μm mesh in surface (0-1 cm) and subsurface (1-5 cm) sediment was significantly correlated (P < 0.01) with %silt/clay (R² = 0.39) and chloroplastic pigments (R² = 0.29), respectively. Variation in median nematode body weight showed similar trends, but relationships between mean nematode body weight and environmental parameters were either relatively weak (subsurface sediment) or not significant (surface sediment). Using a low magnification led to significantly lower (on average by 43%) nematode abundance estimates relative to high magnification (P < 0.001), and the magnitude of this difference was significantly correlated (P < 0.05) with total nematode abundance (R²p = 0.53) and the number of small (≤ 250 μm length) individuals (R²p = 0.05). Our results suggest that organic matter input and sediment characteristics influence the abundance of small nematodes in bathyal communities. The abundance of small individuals can, in turn, influence abundance estimates obtained using different mesh sizes and microscope magnifications

An Evaluation of Performance and Structural Change in Employment- U.S., Nebraska, and Omaha Area Economies, 1988 to 1995

A periodic comparative evaluation of employment and its composition is worthwhile since employment is one of the most basic determinants of the health of the economy and quality of life. Changes in employment over time reflect restructuring of an economy and, ultimately, have social impacts. Moreover, the underlying trends of employment give an indication of an economy\u27s future growth and wellbeing. A future article will evaluate personal income as a measure of economic performance. This article examines employment data developed by the U. S. Department of Commerce, Bureau of Economic Analysis (BEA) and compiled by the Bureau of Business Research (BBR). To provide a consistent and comparable analysis, the initial and terminal years of the study, 1988 and 1995, both represent periods of healthy economic growth. The data tables summarize the economies of the U. S. (Table I), Nebraska (Table 2) and the Omaha Area (Tables 3 and 4). The Omaha area includes the Nebraska counties of Douglas, Sarpy, and Washington in Table 3. Pottawattamie County, Iowa is added to the Omaha area in Table 4. Pottawattamie County is also presented separately in Table 5 to show its growth relative to the rest of the Omaha Area. Employment Changes Summary of Employment Changes in the Economies Conclusio

A PRELIMINARY REVISION OF THE GENUS ATRACTOMORPHA SAUSSURE, 1862

abstract not availabl

Principles of Discrete Time Mechanics: IV. The Dirac Equation, Particles and Oscillons

We apply the principles of discrete time mechanics discussed in earlier papers to the first and second quantised Dirac equation. We use the Schwinger action principle to find the anticommutation relations of the Dirac field and of the particle creation operators in the theory. We find new solutions to the discrete time Dirac equation, referred to as oscillons on account of their extraordinary behaviour. Their principal characteristic is that they oscillate with a period twice that of the fundamental time interval T of our theory. Although these solutions can be associated with definite charge, linear momentum and spin, such objects should not be observable as particles in the continuous time limit. We find that for non-zero T they correspond to states with negative squared norm in Hilbert space. However they are an integral part of the discrete time Dirac field and should play a role in particle interactions analogous to the role of longitudinal photons in conventional quantum electrodynamics.Comment: 27 pages LateX; published versio

Benchmarking high fidelity single-shot readout of semiconductor qubits

Determination of qubit initialisation and measurement fidelity is important for the overall performance of a quantum computer. However, the method by which it is calculated in semiconductor qubits varies between experiments. In this paper we present a full theoretical analysis of electronic single-shot readout and describe critical parameters to achieve high fidelity readout. In particular, we derive a model for energy selective state readout based on a charge detector response and examine how to optimise the fidelity by choosing correct experimental parameters. Although we focus on single electron spin readout, the theory presented can be applied to other electronic readout techniques in semiconductors that use a reservoir.Comment: 19 pages, 8 figure

The role of place branding and image in the development of sectoral clusters: the case of Dubai

This paper contextualizes how place branding and image influence the development of Dubai’s key sectoral clusters, including the key determinants of growth and success under the impression of Porter’s cluster theory. The approach is exploratory and of a qualitative inductive nature. Data was collected through conducting 21 semi-structured interviews with Dubai’s marketing/communication managers and stakeholders. Findings suggest that Dubai’s traditional clusters, namely, trading, tourism and logistics that have strong place branding and image show strong signs of success owing to Dubai’s geographical location (i.e., physical conditions). Among the new clusters, the financial sector is also benefitting from place branding. The results suggest that the success of traditional clusters have a positive spill over effect on the new clusters, in particular on construction and real estate. For policy makers it is worth to note that the recent success of the financial services cluster in Dubai will have positive impact on both, the traditional as well new clusters. The marketing and brand communication managers must consider the correlation and interplay of strength of activities amongst trading, tourism and logistics clusters and its implication while undertaking place branding for clients in their sector

Kilohertz QPO Peak Separation Is Not Constant in Scorpius X-1

We report on a series of twenty ~10^5 c/s, 0.125 msec time-resolution RXTE observations of the Z source and low-mass X-ray binary Scorpius X-1. Twin kilohertz quasi-periodic oscillation (QPO) peaks are obvious in nearly all observations. We find that the peak separation is not constant, as expected in some beat-frequency models, but instead varies from ~310 to ~230 Hz when the centroid frequency of the higher-frequency peak varies from ~875 to ~1085 Hz. We detect none of the additional QPO peaks at higher frequencies predicted in the photon bubble model (PBM), with best-case upper limits on the peaks' power ratio of 0.025. We do detect, simultaneously with the kHz QPO, additional QPO peaks near 45 and 90 Hz whose frequency increases with mass accretion rate. We interpret these as first and second harmonics of the so-called horizontal-branch oscillations well known from other Z sources and usually interpreted in terms of the magnetospheric beat-frequency model (BFM). We conclude that the magnetospheric BFM and the PBM are now unlikely to explain the kHz QPO in Sco X-1. In order to succeed in doing so, any BFM involving the neutron star spin (unseen in Sco X-1) will have to postulate at least one additional unseen frequency, beating with the spin to produce one of the kHz peaks.Comment: 6 pages including 3 figure

Triple-Negative Breast Cancer: An Update on Neoadjuvant Clinical Trials

Triple-negative breast cancer (TNBC) is an aggressive malignancy with a poor prognosis despite the high rates of response to chemotherapy. This scenario highlights the need to develop novel therapies and/or treatment strategies to reduce the mortality associated with TNBC. The neoadjuvant setting provides a model for rapid assessment of treatment efficacy with smaller patient accruals and over shorter periods of time compared to the traditional adjuvant setting. In addition, a clear surrogate endpoint of improved survival, known as pathologic complete response, already exists in this setting. Here, we review current data from completed and ongoing neoadjuvant clinical trials for TNBC