The Effects of Gravitational Slip on the Higher-Order Moments of the Matter Distribution

Cosmological departures from general relativity offer a possible explanation for the cosmic acceleration. To linear order, these departures (quantified by the model-independent parameter $\varpi$, referred to as a `gravitational slip') amplify or suppress the growth of structure in the universe relative to what we would expect to see from a general relativistic universe lately dominated by a cosmological constant. As structures collapse and become more dense, linear perturbation theory is an inadequate descriptor of their behavior, and one must extend calculations to non-linear order. If the effects of gravitational slip extend to these higher orders, we might expect to see a signature of $\varpi$ in the bispectrum of galaxies distributed on the sky. We solve the equations of motion for non-linear perturbations in the presence of gravitational slip and find that, while there is an effect on the bispectrum, it is too weak to be detected with present galaxy surveys. We also develop a formalism for incorporating scale dependence into our description of gravitational slip.Comment: 25 pages, 9 figure

Accelerated Parameter Estimation with DALEχ\chi

We consider methods for improving the estimation of constraints on a high-dimensional parameter space with a computationally expensive likelihood function. In such cases Markov chain Monte Carlo (MCMC) can take a long time to converge and concentrates on finding the maxima rather than the often-desired confidence contours for accurate error estimation. We employ DALE$\chi$ (Direct Analysis of Limits via the Exterior of $\chi^2$) for determining confidence contours by minimizing a cost function parametrized to incentivize points in parameter space which are both on the confidence limit and far from previously sampled points. We compare DALE$\chi$ to the nested sampling algorithm implemented in MultiNest on a toy likelihood function that is highly non-Gaussian and non-linear in the mapping between parameter values and $\chi^2$. We find that in high-dimensional cases DALE$\chi$ finds the same confidence limit as MultiNest using roughly an order of magnitude fewer evaluations of the likelihood function. DALE$\chi$ is open-source and available at https://github.com/danielsf/Dalex.git

DEVELOPMENT OF LUMINESCENT SENSING SYSTEMS WITH CLINICAL APPLICATIONS

As the move towards the miniaturization of many diagnostic and detection systems continues, the need for increasingly versatile yet sensitive labels for use in these systems also grows. Luminescent reporters provide us with a solution to many of the issues at hand through their unique and favorable characteristics. Bioluminescent proteins offer detection at extremely low concentrations and no interference from physiological fluids leading to excellent detection limits, while the vast number of fluorescent proteins and molecules available allows the opportunity to select a tailored reporter for a specific task. Both provide relatively simply instrumentation requirements and have exhibited great promise with many of the miniaturized systems such as lab-on-a-chip and lab-on-a-CD designs. Herein, we describe the novel employment of luminescent reporters for four distinct purposes. First off, by combining both time and wavelength resolution we have expanded the multiplexing capabilities of the photoprotein aequorin beyond duel-analytes, demonstrating the ability to simultaneously detect three separate analytes. Three semi-synthetic aequorin proteins were genetically conjugated to three pro-inflammatory cytokines (interleukins 1, 6, and 8) resulting in aequorin labeled cytokines with differing emission maxima and half lives to allow for the simultaneous detection of all three in a single solution through the elevated physiological concentration range. Secondly a semi-synthetic aequorin variant has been genetically enhanced to serve as an immunolabel and exhibited the ability to sensitively detect the acute myeloid leukemia marker, CD33, down to the attomole level in addition to improving aequorin imaging capabilities. In the third example, the aequorin complex was rationally, genetically split into two parts and attached to the termini of the cAMP selective cAMP receptor protein (CRP) creating a genetically fused molecular switch. The conformational change experienced by CRP upon the binding of cAMP translates into a loss of bioluminescent signal from aequorin and has shown the ability to respond linearly to cAMP over several orders of magnitude. Lastly, through custom design, a reagentless, portable, fluorescent fiber optic detection system has been developed, capable of being integrated into the body through a heart catheter. The system was able to respond to changes in potassium concentration selectively, reproducibly and reversibly with a fast response time of one minute

A Multi-Parameter Investigation of Gravitational Slip

A detailed analysis of gravitational slip, a new post-general relativity cosmological parameter characterizing the degree of departure of the laws of gravitation from general relativity on cosmological scales, is presented. This phenomenological approach assumes that cosmic acceleration is due to new gravitational effects; the amount of spacetime curvature produced per unit mass is changed in such a way that a universe containing only matter and radiation begins to accelerate as if under the influence of a cosmological constant. Changes in the law of gravitation are further manifest in the behavior of the inhomogeneous gravitational field, as reflected in the cosmic microwave background, weak lensing, and evolution of large-scale structure. The new parameter, $\varpi_0$, is naively expected to be of order unity. However, a multiparameter analysis, allowing for variation of all the standard cosmological parameters, finds that $\varpi_0 = 0.09^{+0.74}_{-0.59} (2\sigma)$ where $\varpi_0=0$ corresponds to a $\Lambda$CDM universe under general relativity. Future probes of the cosmic microwave background (Planck) and large-scale structure (Euclid) may improve the limits by a factor of four.Comment: 7 pages, 9 figures, colo

Apgar score and the risk of cause specific infant mortality: a population based cohort study of 1,029,207 livebirths

Background<p></p> The Apgar score has been used worldwide as an index of early neonatal condition for more than 60 years. With advances in health-care service provision, neonatal resuscitation, and infant care, its present relevance is unclear. The aim of the study was to establish the strength of the relation between Apgar score at 5 min and the risk of neonatal and infant mortality, subdivided by specific causes.<p></p> Methods<p></p> We linked routine discharge and mortality data for all births in Scotland, UK between 1992 and 2010. We restricted our analyses to singleton livebirths, in women aged over 10 years, with a gestational age at delivery between 22 and 44 weeks, and excluded deaths due to congenital anomalies or isoimmunisation. We calculated the relative risks (RRs) of neonatal and infant death of neonates with low (0–3) and intermediate (4–6) Apgar scores at 5 min referent to neonates with normal Apgar score (7–10) using binomial log-linear modelling with adjustment for confounders. Analyses were stratified by gestational age at birth because it was a significant effect modifier. Missing covariate data were imputed.<p></p> Findings<p></p> Complete data were available for 1 029 207 eligible livebirths. Across all gestational strata, low Apgar score at 5 min was associated with an increased risk of neonatal and infant death. However, the strength of the association (adjusted RR, 95% CI referent to Apgar 7–10) was strongest at term (p<0·0001). A low Apgar (0–3) was associated with an adjusted RR of 359·4 (95% CI 277·3–465·9) for early neonatal death, 30·5 (18·0–51·6) for late neonatal death, and 50·2 (42·8–59·0) for infant death. We noted similar associations of a lower magnitude for intermediate Apgar (4–6). The strongest associations were for deaths attributed to anoxia and low Apgar (0–3) for term infants (RR 961·7, 95% CI 681·3–1357·5) and preterm infants (141·7, 90·1–222·8). No association between Apgar score at 5 min and the risk of sudden infant death syndrome was noted at any gestational age (RR 0·6, 95% CI 0·1–4·6 at term; 1·2, 0·3–4·8 at preterm).<p></p> Interpretation<p></p> Low Apgar score at 5 min was strongly associated with the risk of neonatal and infant death. Our findings support its continued usefulness in contemporary practice

Five-minute Apgar score and educational outcomes: retrospective cohort study of 751 369 children

Background: The Apgar score is used worldwide for assessing the clinical condition and short-term prognosis of newborn infants. Evidence for a relationship with long-term educational outcomes is conflicting. We investigated whether Apgar score at 5 min after birth was associated with additional support needs (ASN) and educational attainment. Methods: Data on pregnancy, delivery and later educational outcomes for children attending Scottish schools between 2006 and 2011 were collated by linking individual-level data from national educational and maternity databases. The relationship between Apgar score and overall ASN, type-specific ASN and educational attainment was assessed using binary, multinomial and generalised ordinal logistic regression models, respectively. Missing covariate data were imputed. Results: Of the 751 369 children eligible, 9741 (1.3%) had a low or intermediate Apgar score and 49 962 (6.6%) had ASN. Low Apgar score was independently associated with overall ASN status (adjusted OR for Apgar ≤3, OR 1.52 95% CI 1.35 to 1.70), as well as ASN due to cognitive (OR 1.26, 95% CI 1.09 to 1.47), sensory (OR 2.49 95% CI 1.66 to 3.73) and motor (OR 3.57, 95% CI 2.86 to 4.47) impairments. There was a dose-response relationship between Apgar score and overall ASN status: of those scoring 0–3, 10.1% had ASN, compared with 9.1% of those scoring 4–7 and 6.6% of those scoring 7–10. A low Apgar score was associated with lower educational attainment, but this was not robust to adjustment for confounders. Conclusions: Apgar scores are associated with long-term as well as short-term prognoses, and with educational as well as clinical outcomes at the population level

Excavations at Sites 41LK31/32 and 41LK202 in the Choke Canyon Reservoir, South Texas

Site 41 LK 31/32 is located in Live Oak County, southern Texas on a wide horseshoe bend of the Frio River, approximately 16 km west of the Frio\u27s confluence with the Nueces River. Construction of the Choke Canyon Reservoir by the Bureau of Reclamation (USBR) had necessitated an excavation program at the site prior to destruction. Investigations conducted by the Center for Archaeological Research, The University of Texas at San Antonio, were carried out in two stages, culminating in a major excavation during the summer of 1978. An indication of the depth and significance of cultural deposits at the site occurred in 1977 when the Bureau of Reclamation dug a series of 9 m deep geological test pits. Prehistoric occupation zones beginning at a depth of 2.5 meters and continuing to the surface were exposed. The coincidental location of necessary dam ingredients--specific clays and gravel and the site-prompted testing and, later, intensive excavation by the Center for Archaeological Research. Artifacts and depositional information derived from the field work established 41LK31/32 as the location of intermittent occupation by hunting and gathering peoples for more than 5000 years stretching from the Early Archaic through the Late Archaic