1,080 research outputs found
Application of palynological data to the chronology of the Palaeogene lava fields of the British Province: implications for magmatic stratigraphy
New high-precision ages, determined from palynomorph assemblages within intercalated sedimentary deposits, are presented for the Palaeogene lava fields (Skye, Mull and Antrim) of the British Province. These data reveal very rapid averaged eruption rates (1 m/200 yr) and the non-synchronous formation of the lava fields. Eruption of the volumetrically dominant transitional to mildly alkaline lavas of the Skye (58.25-58.0 Ma) and Mull (post 55 Ma) lava fields is separated by the eruption of the MORB-like Preshal More flows of olivine tholeiite found at the top of the preserved sequence on Skye and at the base of the Mull Lava Field. The Lower Formation of the Antrim Lava Field correlates with the Skye Lava Field and the Upper Formation correlates with the Preshal More flows. The new ages indicate that the eruption of the Preshal More flows was synchronous with the main ocean floor spreading event which occurred 500 km to the NW, at c. 55 Ma, during Chron 24r. A combined thinspot and channelized plume model may best explain the temporal and spatial distributions of the lava fields and associated subvolcanic complexes of the British Province
The power spectrum of the circular noise
The circular noise is important in connection to Mach's principle, and also
as a possible probe of the Unruh effect. In this letter the power spectrum of
the detector following the Trocheries-Takeno motion in the Minkowski vacuum is
analytically obtained in the form of an infinite series. A mean distribution
function and corresponding energy density are obtained for this particular
detected noise. The analogous of a non constant temperature distribution is
obtained. And in the end, a brief discussion about the equilibrium
configuration is given.Comment: accepted for publication in GR
A Note on the Integral Formulation of Einstein's Equations Induced on a Braneworld
We revisit the integral formulation (or Green's function approach) of
Einstein's equations in the context of braneworlds. The integral formulation
has been proposed independently by several authors in the past, based on the
assumption that it is possible to give a reinterpretation of the local metric
field in curved spacetimes as an integral expression involving sources and
boundary conditions. This allows one to separate source-generated and
source-free contributions to the metric field. As a consequence, an exact
meaning to Mach's Principle can be achieved in the sense that only
source-generated (matter fields) contributions to the metric are allowed for;
universes which do not obey this condition would be non-Machian. In this paper,
we revisit this idea concentrating on a Randall-Sundrum-type model with a
non-trivial cosmology on the brane. We argue that the role of the surface term
(the source-free contribution) in the braneworld scenario may be quite subtler
than in the 4D formulation. This may pose, for instance, an interesting issue
to the cosmological constant problem.Comment: 10 pages, no figures, accepted for publication in the General
Relativity and Gravitation Journa
Maturity Onset Diabetes of the Young (MODY)
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147788/1/dme199613s690.pd
Societal expectations and well-being of academics: views from university lecturers in Ghana
Background:- The study aimed to investigate how societal expectation on educational accomplishments can affect workplace well-being of university lecturers. University education is seen by society as the highest level of educational accomplishment in a person’s life and people with such accomplishments are often held in higher esteem by society. In Ghana, this expectation puts pressure on lecturers who are known to have attained higher educational accomplishments.
Methods:- The study used a qualitative research approach to solicit views from 18 public university lecturers in Ghana. Interpretative Phenomenology Approach (IPA) for data analysis was used to interpret the opinions of lecturers about what society expects of them, how that affects their well-being at work and shifts that are needed to address those expectations.
Results:- The study found that society indeed expects a lot from university lecturers (core university functions and other cultural and economic issues). Societal expectations have both positive and negative effects on the well-being of lecturers. Findings show that respect that lecturers receive from society provides leverage for positive well-being, while financial pressures placed on them tend to create emotional stresses which impact negatively on their well-being.
Conclusion:- To our knowledge, this study is the first of its kind to examine the experiences of well-being amongst university academics in Ghana. Results suggest that how the role of university academics is perceived by society can create pressures which affect their well-being negatively. This study highlights the importance of these findings and their impact on well-being. It shows that societal expectations are linked to sociocultural beliefs and economic factors in a developing country context. The authors recommend a mind-set shift amongst society and academics to bring expectations from both sides closer together; through education; engaging community talks on the pressures of societal expectations and demands to create awareness, and observing cultural beliefs that impact the understanding of well-being issues. These initiatives could potentially reduce the pressure of unrealistic expectations on academics and other “knowledge workers”
VNIR Multispectral Observations of Rocks at Spirit of St. Louis Crater and Marathon Valley on Th Rim of Endeavour Crater Made by the Opportunity Rover Pancam
The Mars Exploration Rover Opportunity has been exploring the western rim of the 22 km diameter Endeavour crater since August, 2011. Recently, Opportunity has reached a break in the Endeavour rim that the rover team has named Mara-thon Valley. This is the site where orbital observations from the MRO CRISM imaging spectrometer indicated the presence of iron smectites. On the outer western portion of Marathon Valley, Opportunity explored the crater-form feature dubbed Spirit of St. Louis (SoSL) crater. This presentation describes the 430 to 1009 nm (VNIR) reflectance, measured by the rover's Pancam, of rock units present both at Spirit of St. Louis and within Marathon Valley
Short communication: Development of an equation for estimating methane emissions of dairy cows from milk Fourier transform mid-infrared spectra by using reference data obtained exclusively from respiration chambers
Evaluation and mitigation of enteric methane (CH4) emissions from ruminant livestock, in particular from dairy cows, have acquired global importance for sustainable, climate-smart cattle production. Based on CH4 reference measurements obtained with the SF6 tracer technique to determine ruminal CH4 production, a current equation permits evaluation of individual daily CH4 emissions of dairy cows based on milk Fourier transform mid-infrared (FT-MIR) spectra. However, the respiration chamber (RC) technique is considered to be more accurate than SF6 to measure CH4 production from cattle. This study aimed to develop an equation that allows estimating CH4 emissions of lactating cows recorded in an RC from corresponding milk FT-MIR spectra and to challenge its robustness and relevance through validation processes and its application on a milk spectral database. This would permit confirming the conclusions drawn with the existing equation based on SF6 reference measurements regarding the potential to estimate daily CH4 emissions of dairy cows from milk FT-MIR spectra. A total of 584 RC reference CH4 measurements (mean ± standard deviation of 400 ± 72 g of CH4/d) and corresponding standardized milk mid-infrared spectra were obtained from 148 individual lactating cows between 7 and 321 d in milk in 5 European countries (Germany, Switzerland, Denmark, France, and Northern Ireland). The developed equation based on RC measurements showed calibration and cross-validation coefficients of determination of 0.65 and 0.57, respectively, which is lower than those obtained earlier by the equation based on 532 SF6 measurements (0.74 and 0.70, respectively). This means that the RC-based model is unable to explain the variability observed in the corresponding reference data as well as the SF6-based model. The standard errors of calibration and cross-validation were lower for the RC model (43 and 47 g/d vs. 66 and 70 g/d for the SF6 version, respectively), indicating that the model based on RC data was closer to actual values. The root mean squared error (RMSE) of calibration of 42 g/d represents only 10% of the overall daily CH4 production, which is 23 g/d lower than the RMSE for the SF6-based equation. During the external validation step an RMSE of 62 g/d was observed. When the RC equation was applied to a standardized spectral database of milk recordings collected in the Walloon region of Belgium between January 2012 and December 2017 (1,515,137 spectra from 132,658 lactating cows in 1,176 different herds), an average ± standard deviation of 446 ± 51 g of CH4/d was estimated, which is consistent with the range of the values measured using both RC and SF6 techniques. This study confirmed that milk FT-MIR spectra could be used as a potential proxy to estimate daily CH4 emissions from dairy cows provided that the variability to predict is covered by the model
Thermodynamic Gravity and the Schrodinger Equation
We adopt a 'thermodynamical' formulation of Mach's principle that the rest
mass of a particle in the Universe is a measure of its long-range collective
interactions with all other particles inside the horizon. We consider all
particles in the Universe as a 'gravitationally entangled' statistical ensemble
and apply the approach of classical statistical mechanics to it. It is shown
that both the Schrodinger equation and the Planck constant can be derived
within this Machian model of the universe. The appearance of probabilities,
complex wave functions, and quantization conditions is related to the
discreetness and finiteness of the Machian ensemble.Comment: Minor corrections, the version accepted by Int. J. Theor. Phy
Finding, Characterizing, and Classifying Variable Sources in Multi-epoch Sky Surveys: QSOs and RR Lyrae in PS1 3π data
In area and depth, the Pan-STARRS1 (PS1) 3π survey is unique among many-epoch, multi-band surveys and has enormous potential for the all-sky identification of variable sources. PS1 has observed the sky typically seven times in each of its five bands (grizy) over 3.5 years, but unlike SDSS, not simultaneously across the bands. Here we develop a new approach for quantifying statistical properties of non-simultaneous, sparse, multi-color light curves through light curve structure functions, effectively turning PS1 into a ~35-epoch survey. We use this approach to estimate variability amplitudes and timescales (ωr, τ) for all point sources brighter than rP1 = 21.5 mag in the survey. With PS1 data on SDSS Stripe 82 as "ground truth," we use a Random Forest Classifier to identify QSOs and RR Lyrae based on their variability and their mean PS1 and WISE colors. We find that, aside from the Galactic plane, QSO and RR Lyrae samples of purity ~75% and completeness ~92% can be selected. On this basis we have identified a sample of ~1,000,000 QSO candidates, as well as an unprecedentedly large and deep sample of ~150,000 RR Lyrae candidates with distances from ~10 to ~120 kpc. Within the Draco dwarf spheroidal, we demonstrate a distance precision of 6% for RR Lyrae candidates. We provide a catalog of all likely variable point sources and likely QSOs in PS1, a total of 25.8 × 106 sources
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