Supermassive black hole binaries (SMBHBs) should form frequently in galactic nuclei as a result of galaxy mergers. At subparsec separations, binaries become strong sources of low-frequency ...gravitational waves (GWs), targeted by Pulsar Timing Arrays. We used recent upper limits on continuous GWs from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) 11 yr data set to place constraints on putative SMBHBs in nearby massive galaxies. We compiled a comprehensive catalog of ∼44,000 galaxies in the local universe (up to redshift ∼0.05) and populated them with hypothetical binaries, assuming that the total mass of the binary is equal to the SMBH mass derived from global scaling relations. Assuming circular equal-mass binaries emitting at NANOGrav's most sensitive frequency of 8 nHz, we found that 216 galaxies are within NANOGrav's sensitivity volume. We ranked the potential SMBHBs based on GW detectability by calculating the total signal-to-noise ratio such binaries would induce within the NANOGrav array. We placed constraints on the chirp mass and mass ratio of the 216 hypothetical binaries. For 19 galaxies, only very unequal-mass binaries are allowed, with the mass of the secondary less than 10% that of the primary, roughly comparable to constraints on an SMBHB in the Milky Way. However, we demonstrated that the (typically large) uncertainties in the mass measurements can weaken the upper limits on the chirp mass. Additionally, we were able to exclude binaries delivered by major mergers (mass ratio of at least 1/4) for several of these galaxies. We also derived the first limit on the density of binaries delivered by major mergers purely based on GW data.
Tracheal Basal Cells Cole, Brook B; Smith, Russell W; Jenkins, Kimberly M ...
The American journal of pathology,
2010, Letnik:
177, Številka:
1
Journal Article
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Analysis of lineage relationships in the naphthalene-injured tracheal epithelium demonstrated that two multipotential keratin 14–expressing cells (K14ECs) function as progenitors for Clara and ...ciliated cells. These K14EC were distinguished by their self-renewal capacity and were hypothesized to reside at the stem and transit amplifying tiers of a tissue-specific stem cell hierarchy. In this study, we used gene expression and histomorphometric analysis of the steady-state and naphthalene-injured trachea to evaluate the predictions of this model. We found that the steady-state tracheal epithelium is maintained by two progenitor cell pools, secretory and basal cells, and the latter progenitor pool is further divided into two subsets, keratin 14–negative and –positive. After naphthalene-mediated depletion of the secretory and ciliated cell types, the two basal cell pools coordinate to restore the epithelium. Both basal cell types up-regulate keratin 14 and generate a broadly distributed, abundant, and highly mitotic cell pool. Furthermore, basal cell proliferation is associated with generation of differentiated Clara and ciliated cells. The uniform distribution of basal cell progenitors and of their differentiated progeny leads us to propose that the hierarchical organization of tracheal reparative cells be revised to include a facultative basal cell progenitor pool.
We search for a first-order phase transition gravitational wave signal in 45 pulsars from the NANOGrav 12.5-year dataset. We find that the data can be modeled in terms of a strong first order phase ...transition taking place at temperatures below the electroweak scale. However, we do not observe any strong preference for a phase-transition interpretation of the signal over the standard astrophysical interpretation in terms of supermassive black hole mergers; but we expect to gain additional discriminating power with future datasets, improving the signal to noise ratio and extending the sensitivity window to lower frequencies. An interesting open question is how well gravitational wave observatories could separate such signals.
The sequential treatment of Lewis acids with N,N'-bidentate ligands and thereafter with ButLi has afforded a series of hydride-encapsulating alkali metal polyhedra. While the use of Me3Al in ...conjunction with Ph(2-C5H4N)NH gives Ph(2-C5H4N)NAlMe2 and this reacts with MeLi in thf to yield the simple 'ate complex Ph(2-C5H4N)NAlMe3Li.thf, the employment of an organolithium substrate capable of beta-hydride elimination redirects the reaction significantly. Whereas the use of ButLi has previously yielded a main group interstitial hydride in which H- exhibits micro6-coordination, it is shown here that variability in the coordination sphere of the encapsulated hydride may be induced by manipulation of the organic ligand. Reaction of (c-C6H11)(2-C5H4N)NH with Me3Al/ButLi yields {(c-C6H11)(2-C5H4N)N}6HLi8+(But2AlMe2)2Li-, which is best viewed as incorporating only linear di-coordination of the hydride ion. The guanidine 1,3,4,6,7,8-hexahydro-2H-pyrimido1,2-apyrimidine (hppH) in conjunction with Me2Zn/ButLi yields the micro8-hydride (hpp)6HLi8+But3Zn-.0.5PhMe. Formation of the micro8-hydride (hpp)6HLi8+ButBEt3- is revealed by employment of the system Et3B/ButLi. A new and potentially versatile route to interstitial hydrides of this class is revealed by synthesis of the mixed borohydride-lithium hydride species (hpp)6HLi8+Et3BH- and (hpp)6HLi8+(Et3B)2H- through the direct combination of hppLi with Et3BHLi.
The aim of this study was to determine test‐retest reliability and concurrent validity of vertical force‐velocity‐power (FVP) profiles using Smith machine and free‐weight countermovement jumps ...(CMJs). A repeated‐measure cross‐over design with randomized load order and counterbalanced trials was employed. Sixteen resistance‐trained males (age: 26.4 ± 3.9 years, height: 179.6 ± 8.1 cm, body mass: 84.5 ± 10.8 kg) performed maximal loaded CMJs with 4–50 kg on six occasions, with three trials utilizing a Smith machine and three utilizing free‐weights. Jump height was estimated with a linear‐position transducer, and the Samozino computation method estimated theoretical maximal jump parameters. Reliability and concurrent validity were determined for jump height for each jump load and estimated theoretical maximal jump parameters using estimates of bias (mean difference, 95% limits of agreement) and agreement (intraclass correlation coefficients, ICCs). The jump height and maximum theoretical power demonstrated good‐to‐excellent reliability between sessions for both methods (ICC: 0.872–0.947) and concurrent validity between methods (ICC: 0.885–0.969). However, reliability for theoretical maximal force, velocity, and force‐velocity gradient was not as high using either method (ICC = 0.320–0.615) and concurrent validity was poor (ICC: 0.122–0.340). In summary, using both jump methods, a linear‐position transducer provides reliable jump height and theoretical maximal power values. However, our data do not support the reliability or validity of FV relationships using linear position transducers.
Highlights
Countermovement jump (CMJ) height can be reliably assessed with a linear‐position transducer when adding mass (4–50 kg) with either a Smith machine or free‐weights.
Theoretical maximum force, velocity, and force‐velocity gradients derived from the Smith machine and free‐weights are neither reliable, nor consistent between methods.
Smith machine and free‐weight CMJ methods cannot be used interchangeably to develop force‐velocity‐power profiles with a linear position transducer.
Although progress has been made in the last few decades at reducing ambient concentrations of air pollutants, scientific evidence suggests that there remains a risk to human health from exposure to ...these pollutants at current levels in Canada. Much of the motivation for air pollution reduction efforts is to protect population health. This article presents a method of monitoring changes in air pollution-related health outcomes over time in conjunction with temporal changes in ambient pollution concentrations. The progress measure is a function of temporal changes in location-specific ambient concentrations and the potentially time-dependent association between those concentrations and daily deaths. The progress measure can be determined for a single location or at a national level. The measure can also be extended to include several pollutants. The progress measure is illustrated with an example of how changes in nitrogen dioxide levels in 12 Canadian cities from 1981 to 1999 have translated into changes in the percent of nonaccidental mortality burden attributable to this pollutant over time.
1University of Iowa Healthcare, Iowa City, IA; 2The University of Texas MD Anderson Cancer Center, Houston, TX; 3Massachusetts General Hospital, Boston, MA; 4Mayo Clinic, Jacksonville, FL; ...5University of Washington, Seattle, WA; 6West Cancer Center, Germantown TN; 7University of Colorado Comprehensive Cancer Center, Aurora, CO; 8University of Pennsylvania, Philadelphia, PA; 9Natera, Inc., San Carlos, CA BACKGROUND. MRD positivity rates and ctDNA quantification (mean tumor molecules/mL) are shown in Table 1. ctDNA detection was significantly associated with stage of disease (P .0001; Chi-square: 50.94, df = 3). PK would like to acknowledge research funding from Advanced Accelerator Applications, Array BioPharma, Bristol Myers Squibb, Celgene; consultancy/advisory board:
Wool was at the forefront of the establishment of England as a European political and economic power. This volume was the first study of the medieval wool market in over twenty years. It investigates ...the role of advance contracts for the sale of wool and their impact on medieval monasteries.
The recent revelation that there are correlated period derivative and pulse shape changes in pulsars has dramatically changed our understanding of timing noise as well as the relationship between the ...radio emission and the properties of the magnetosphere as a whole. Using Gaussian processes we are able to model timing and emission variability using a regression technique that imposes no functional form on the data. We revisit the pulsars first studied by Lyne et al. (2010). We not only confirm the emission and rotational transitions revealed therein, but reveal further transitions and periodicities in 8 years of extended monitoring. We also show that in many of these objects the pulse profile transitions between two well-defined shapes, coincident with changes to the period derivative. With a view to the SKA and other telescopes capable of higher cadence we also study the detection limitations of period derivative changes.
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