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A Record of Lateglacial and Early Holocene Environmental and Ecological Change from Southwestern Connecticut, USA
Analyses of a sediment core from Highstead Swamp in southwestern Connecticut, USA, reveal Lateglacial and early Holocene ecological and hydrological changes. Lateglacial pollen assemblages are dominated by Picea and Pinus subg. Pinus, and the onset of the Younger Dryas (YD) cold interval is evidenced by higher abundance of Abies and Alnus viridis subsp. crispa. As climate warmed at the end of the YD, Picea and Abies declined and Pinus strobus became the dominant upland tree species. A shift from lacustrine sediment to organic peat at the YD-Holocene boundary suggests that the lake that existed in the basin during the Lateglacial interval developed into a swamp in response to reduced effective moisture. A change in wetland vegetation from Myrica gale to Alnus incana subsp. rugosa and Sphagnum is consistent with this interpretation of environmental changes at the beginning of the HoloceneOther Research Uni
The Evolution of Distorted Rotating Black Holes III: Initial Data
In this paper we study a new family of black hole initial data sets
corresponding to distorted ``Kerr'' black holes with moderate rotation
parameters, and distorted Schwarzschild black holes with even- and odd-parity
radiation. These data sets build on the earlier rotating black holes of Bowen
and York and the distorted Brill wave plus black hole data sets. We describe
the construction of this large family of rotating black holes. We present a
systematic study of important properties of these data sets, such as the size
and shape of their apparent horizons, and the maximum amount of radiation that
can leave the system during evolution. These data sets should be a very useful
starting point for studying the evolution of highly dynamical black holes and
can easily be extended to 3D.Comment: 16 page
Absorption-Line Systems and Galaxies in Front of the Second Brightest Quasar, PHL 1811
The extraordinarily bright quasar PHL 1811 at a redshift z = 0.192 provides
an attractive opportunity to use ultraviolet absorption-line spectroscopy to
study the properties of gas systems in the local universe. An R = 20,000 far-UV
spectrum recorded by FUSE revealed 7 extragalactic absorption systems, one of
which is a Lyman limit system at z = 0.08093 accompanied by three systems
having redshifts which differ from it by less than 0.008. The abundance of O
with respect to Fe in the Lyman limit system is not much different from the
solar abundance ratio. Supplementary low resolution spectra recorded by STIS
(on HST) at longer wavelengths helped to substantiate our identifications of
systems in the FUSE spectrum and suggested the presence of an additional 4
systems that could be detected only through their Ly-alpha features.
Spectroscopy at visible wavelengths of 7 galaxies within approximately 2' of
PHL 1811 indicated that 2 of them are near the redshift of the quasar and 4
have redshifts within 850 km/s of the extragalactic absorption systems. The
Lyman limit system is likely associated with an L* galaxy lying 23" from the
sightline. Finally, in addition to prominent features at very low velocities
arising from the disk of our Galaxy, the strong resonance transitions of C II
and Mg II show evidence for material at v = -200 km/s; the column densities of
these two species suggest that 17.7 < log N(H I) < 18.1 if the material has a
solar composition.Comment: 47 pages, 5 figures, to appear in the June 2003 issue of the
Astronomical Journa
The Impossibility of a Perfectly Competitive Labor Market
Using the institutional theory of transaction cost, I demonstrate that the assumptions of the competitive labor market model are internally contradictory and lead to the conclusion that on purely theoretical grounds a perfectly competitive labor market is a logical impossibility. By extension, the familiar diagram of wage determination by supply and demand is also a logical impossibility and the neoclassical labor demand curve is not a well-defined construct. The reason is that the perfectly competitive market model presumes zero transaction cost and with zero transaction cost all labor is hired as independent contractors, implying multi-person firms, the employment relationship, and labor market disappear. With positive transaction cost, on the other hand, employment contracts are incomplete and the labor supply curve to the firm is upward sloping, again causing the labor demand curve to be ill-defined. As a result, theory suggests that wage rates are always and everywhere an amalgam of an administered and bargained price. Working Paper 06-0
High-Dispersion Spectroscopy of the X-Ray Transient RXTE J0421+560 (= CI Cam) during Outburst
We obtained high dispersion spectra of CI Cam, the optical counterpart of XTE
J0421+560, two weeks after the peak of its short outburst in 1998 April. The
optical counterpart is a supergiant B[e] star emitting a two-component wind.
The cool wind (the source of narrow emission lines of neutral and ionized
metals) has a velocity of 32 km/s and a temperature near 8000 K. Dense and
roughly spherical, it fills the space around the sgB[e] star, and, based on the
size of an infrared-emitting dust shell around the system, extends to a radius
between 13 - 50 AU. It carries away mass at a high rate, Mdot > 10^(-6) solar
masses per year. The hot wind has a velocity in excess of 2500 km/s and a
temperature of 1.7 +/-0.3 x 10^4 K. From UV spectra of CI Cam obtained in 2000
March with Hubble Space Telescope, we derive a differential extinction E(B-V) =
0.85 +/- 0.05. We derive a distance to CI Cam > 5 kpc. Based on this revised
distance, the X-ray luminosity at the peak of the outburst was L(2-25 keV) >
3.0 x 10^38 erg/s, making CI Cam one of the most luminous X-ray transients. The
ratio of quiescent to peak luminosity in the 2 - 25 keV band is < 1.7 x
10^(-6). The compact star in CI Cam is immersed in the dense circumstellar wind
from the sgB[e] star and burrows through the wind producing little X-ray
emission except for rare transient outbursts. This picture (a compact star
traveling in a wide orbit through the dense circumstellar envelope of a sgB[e]
star, occasionally producing transient X-ray outbursts) makes CI Cam unique
among the known X-ray binaries. Strong circumstantial evidence suggests that
the compact object is a black hole, not a neutron star. We speculate that the
X-ray outburst was short because the accretion disk around the compact star is
fed from a stellar wind and is smaller than disks fed by Roche-lobe overflow.Comment: 20 pages incl. 3 tables + 10 figures; accepted for publication in
Feb. 2002 Astrophysical Journal; full resolution figures available at
http://pisces.as.utexas.edu/robinson/Papers/papers00-04.htm
C Wright Mills, power and the power elites ? a reappraisal
This paper revisits and presents a critical appraisal of Mills's analysis of power and the power elite. There are signs of a revival of interest in Mills, but recent commentators have shown little interest in the intellectual, social or political context of his analysis. Setting Mills's thesis in its historical context, we consider an element of his project that has been particularly neglected in recent discussion: Mills's search for possible ways of redistributing power and his attempt to forge an ethico-political stance. Reflecting on recent discussion of contemporary elite formations, we comment on what critics might take from Mills in our own time in relation to the analysis of elites and the politics of critical management studies
Application of quantitative proteomics to discover biomarkers for tick resistance in cattle
Introduction: Breeding for tick resistance is a sustainable alternative to control cattle ticks due to widespread resistance to acaricidal drugs and the lack of a protective vaccine. The most accurate method used to characterise the phenotype for tick resistance in field studies is the standard tick count, but this is labour-intensive and can be hazardous to the operator. Efficient genetic selection requires reliable phenotyping or biomarker(s) for accurately identifying tick-resistant cattle. Although breed-specific genes associated with tick resistance have been identified, the mechanisms behind tick resistance have not yet been fully characterised.
Methods: This study applied quantitative proteomics to examine the differential abundance of serum and skin proteins using samples from naïve tick-resistant and -susceptible Brangus cattle at two-time points following tick exposure. The proteins were digested into peptides, followed by identification and quantification using sequential window acquisition of all theoretical fragment ion mass spectrometry.
Results: Resistant naïve cattle had a suite of proteins associated with immune response, blood coagulation and wound healing that were significantly (adjusted P < 10- 5) more abundant compared with susceptible naïve cattle. These proteins included complement factors (C3, C4, C4a), alpha-1-acid glycoprotein (AGP), beta-2-glycoprotein-1, keratins (KRT1 & KRT3) and fibrinogens (alpha & beta). The mass spectrometry findings were validated by identifying differences in the relative abundance of selected serum proteins with ELISA. The proteins showing a significantly different abundance in resistant cattle following early and prolonged tick exposures (compared to resistant naïve) were associated with immune response, blood coagulation, homeostasis, and wound healing. In contrast, susceptible cattle developed some of these responses only after prolonged tick exposure.
Discussion: Resistant cattle were able to transmigrate immune-response related proteins towards the tick bite sites, which may prevent tick feeding. Significantly differentially abundant proteins identified in this research in resistant naïve cattle may provide a rapid and efficient protective response to tick infestation. Physical barrier (skin integrity and wound healing) mechanisms and systemic immune responses were key contributors to resistance. Immune response-related proteins such as C4, C4a, AGP and CGN1 (naïve samples), CD14, GC and AGP (post-infestation) should be further investigated as potential biomarkers for tick resistance
Antibody correlates of protection from SARS-CoV-2 reinfection prior to vaccination : a nested case-control within the SIREN study
Funding: This study was supported by the U.K. Health Security Agency, the U.K. Department of Health and Social Care (with contributions from the governments in Northern Ireland, Wales, and Scotland), the National Institute for Health Research, and grant from the UK Medical Research Council (grant number MR/W02067X/1). This work was supported by the Francis Crick Institute which receives its core funding from Cancer Research UK (CC2087, CC1283), the UK Medical Research Council (CC2087, CC1283), and the Wellcome Trust (CC2087, CC1283).Objectives To investigate serological differences between SARS-CoV-2 reinfection cases and contemporary controls, to identify antibody correlates of protection against reinfection. Methods We performed a case-control study, comparing reinfection cases with singly infected individuals pre-vaccination, matched by gender, age, region and timing of first infection. Serum samples were tested for anti-SARS-CoV-2 spike (anti-S), anti-SARS-CoV-2 nucleocapsid (anti-N), live virus microneutralisation (LV-N) and pseudovirus microneutralisation (PV-N). Results were analysed using fixed effect linear regression and fitted into conditional logistic regression models. Results We identified 23 cases and 92 controls. First infections occurred before November 2020; reinfections occurred before February 2021, pre-vaccination. Anti-S levels, LV-N and PV-N titres were significantly lower among cases; no difference was found for anti-N levels. Increasing anti-S levels were associated with reduced risk of reinfection (OR 0·63, CI 0·47-0·85), but no association for anti-N levels (OR 0·88, CI 0·73-1·05). Titres >40 were correlated with protection against reinfection for LV-N Wuhan (OR 0·02, CI 0·001–0·31) and LV-N Alpha (OR 0·07, CI 0·009–0·62). For PV-N, titres >100 were associated with protection against Wuhan (OR 0·14, CI 0·03–0·64) and Alpha (0·06, CI 0·008–0·40). Conclusions Before vaccination, protection against SARS-CoV-2 reinfection was directly correlated with anti-S levels, PV-N and LV-N titres, but not with anti-N levels. Detectable LV-N titres were sufficient for protection, whilst PV-N titres >100 were required for a protective effect. Trial registration number ISRCTN11041050Publisher PDFPeer reviewe
Comparison of transcriptional responses in liver tissue and primary hepatocyte cell cultures after exposure to hexahydro-1, 3, 5-trinitro-1, 3, 5-triazine
BACKGROUND: Cell culture systems are useful in studying toxicological effects of chemicals such as Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), however little is known as to how accurately isolated cells reflect responses of intact organs. In this work, we compare transcriptional responses in livers of Sprague-Dawley rats and primary hepatocyte cells after exposure to RDX to determine how faithfully the in vitro model system reflects in vivo responses. RESULTS: Expression patterns were found to be markedly different between liver tissue and primary cell cultures before exposure to RDX. Liver gene expression was enriched in processes important in toxicology such as metabolism of amino acids, lipids, aromatic compounds, and drugs when compared to cells. Transcriptional responses in cells exposed to 7.5, 15, or 30 mg/L RDX for 24 and 48 hours were different from those of livers isolated from rats 24 hours after exposure to 12, 24, or 48 mg/Kg RDX. Most of the differentially expressed genes identified across conditions and treatments could be attributed to differences between cells and tissue. Some similarity was observed in RDX effects on gene expression between tissue and cells, but also significant differences that appear to reflect the state of the cell or tissue examined. CONCLUSION: Liver tissue and primary cells express different suites of genes that suggest they have fundamental differences in their cell physiology. Expression effects related to RDX exposure in cells reflected a fraction of liver responses indicating that care must be taken in extrapolating from primary cells to whole animal organ toxicity effects
The state of the Martian climate
60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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