4,487 research outputs found
Spectral distribution of solar radiation
Available quantitative data on solar total and spectral irradiance are examined in the context of utilization of solar irradiance for terrestrial applications of solar energy. The extraterrestrial solar total and spectral irradiance values are also reviewed. Computed values of solar spectral irradiance at ground level for different air mass values and various levels of atmospheric pollution or turbidity are presented. Wavelengths are given for computation of solar, absorptance, transmittance and reflectance by the 100 selected-ordinate method and by the 50 selected-ordinate method for air mass 1.5 and 2 solar spectral irradiance for the four levels of atmospheric pollution
A new ordered compactification
A new Wallman-type ordered compactification ÎłâX is constructed using maximal CZ-filters
(which have filter bases obtained from increasing and decreasing zero sets) as the underlying set. A
necessary and sufficient condition is given for ÎłâX to coincide with the Nachbin compactification βâX; in
particular ÎłâX=βâX whenever X has the discrete order. The Wallman ordered compactification ĎâX
equals ÎłâX whenever X is a subspace of Rn. It is shown that ÎłâX is always T1, but can fail to be T1-ordered
or T2
Distinguishing cancerous from non-cancerous cells through analysis of electrical noise
Since 1984, electric cell-substrate impedance sensing (ECIS) has been used to
monitor cell behavior in tissue culture and has proven sensitive to cell
morphological changes and cell motility. We have taken ECIS measurements on
several cultures of non-cancerous (HOSE) and cancerous (SKOV) human ovarian
surface epithelial cells. By analyzing the noise in real and imaginary
electrical impedance, we demonstrate that it is possible to distinguish the two
cell types purely from signatures of their electrical noise. Our measures
include power-spectral exponents, Hurst and detrended fluctuation analysis, and
estimates of correlation time; principal-component analysis combines all the
measures. The noise from both cancerous and non-cancerous cultures shows
correlations on many time scales, but these correlations are stronger for the
non-cancerous cells.Comment: 8 pages, 4 figures; submitted to PR
Substituent Effects and Nearly Degenerate Transition States: Rational Design of Substrates for the Tandem WolffâCope Reaction
The substrate scope for a ketene-assisted Cope (tandem WolffâCope) reaction is elucidated from first-principles quantum mechanics. An alternate pathway (trans) leading to an undesired and unstable product lies perilously close (âź2.5 kcal/mol) to the primary (cis) reaction pathway; this near-degeneracy arises from preferential ketene stabilization of a radicaloid trans transition state over an aromatic cis transition state. Normally, substitution at âforbiddenâ sites causes the alternate pathway to be favored and the reaction to fail, but using simple conformational analysis principles we design substrates that defy this rule
Order-theoretical connectivity
Order-theoretically connected posets are introduced and applied to create the notion of T-connectivity in ordered topological spaces. As special cases T-connectivity contains classical connectivity, order-connectivity, and link-connectivity
Composition of early life leukocyte populations in preterm infants with and without late-onset sepsis
Background
Composition of leukocyte populations in the first month of life remains incompletely characterised, particularly in preterm infants who go on to develop late-onset sepsis (LOS).
Aim
To characterise and compare leukocyte populations in preterm infants with and without LOS during the first month of life.
Study design
Single-centre prospective observational cohort study.
Participants
Infants born <30 weeks gestational age (GA).
Outcome measures
Peripheral blood samples were collected at 1, 7, 14, 21 and 28 days of life. Leukocyte populations were characterised using 5-fluorophore-6-marker flow cytometry. Absolute leukocyte counts and frequency of total CD45+ leukocytes of each population were adjusted for GA, birth weight z-scores, sex and total leukocyte count.
Results
Of 119 preterm infants enrolled, 43 (36%) had confirmed or clinical LOS, with a median onset at 13 days (range 6â26). Compared to infants without LOS, the adjusted counts and frequency of neutrophils, basophils and non-cytotoxic T lymphocytes were generally lower and immature granulocytes were higher over the first month of life in infants who developed LOS. Specific time point comparisons identified lower adjusted neutrophil counts on the first day of life in those infants who developed LOS more than a week later, compared to those without LOS, albeit levels were within the normal age-adjusted range. Non-cytotoxic T lymphocyte counts and/or frequencies were lower in infants following LOS on days 21 and 28 when compared to those who did not develop LOS.
Conclusion
Changes in non-cytotoxic T lymphocytes occurred following LOS suggesting sepsis-induced immune suppression
Schubert calculus of Richardson varieties stable under spherical Levi subgroups
We observe that the expansion in the basis of Schubert cycles for
of the class of a Richardson variety stable under a spherical Levi subgroup is
described by a theorem of Brion. Using this observation, along with a
combinatorial model of the poset of certain symmetric subgroup orbit closures,
we give positive combinatorial descriptions of certain Schubert structure
constants on the full flag variety in type . Namely, we describe
when and are inverse to Grassmannian permutations with unique descents
at and , respectively. We offer some conjectures for similar rules in
types and , associated to Richardson varieties stable under spherical
Levi subgroups of SO(2n+1,\C) and SO(2n,\C), respectively.Comment: Section 4 significantly shortened, and other minor changes made as
suggested by referees. Final version, to appear in Journal of Algebraic
Combinatoric
'White knuckle care work' : violence, gender and new public management in the voluntary sector
Drawing on comparative data from Canada and Scotland, this article explores reasons why violence is tolerated in non-profit care settings. This article will provide insights into how workers' orientations to work, the desire to care and the intrinsic rewards from working in a non-profit context interact with the organization of work and managerially constructed workplace norms and cultures (Burawoy, 1979) to offset the tensions in an environment characterized by scarce resources and poor working conditions. This article will also outline how the same environment of scarce resources causes strains in management's efforts to establish such cultures. Working with highly excluded service users with problems that do not respond to easy interventions, workers find themselves working at the edge of their endurance, hanging on by their fingernails, and beginning to participate in various forms of resistance; suggesting that even among the most highly committed, 'white knuckle care' may be unsustainable
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