1,329 research outputs found
Solubilization Of Calcium Dodecyl Sulfate In A Micellar Solution And In Lamellar Liquid Crystal
Calcium dodecyl sulfate (CDS) was solubilized in the aqueous micellar solution of sodium dodecyl sulfate and in the lamellar liquid crystal obtained from water, sodium dodecyl sulfate and decanal. The solubilization of CDS in the micellar solution was strongly increased with the concentration of sodium dodecyl sulfate while the maximum amount of CDS solubilized in the liquid crystal remained similar. The solubilization in the micellar solution was gradually increased with the alcohol content with a sudden reduction to zero at the decanol/sodium-dodecyl-sulfate ratio marking the end of the micellar region with no calcium soap being present. The dependence of the solubilization on the decanol/sodium-dodecyl-sulfate ratio was the opposite in the lamellar liquid-crystalline phase. It suddenly rose to a maximum at the lowest values of the alcohol/sodium-dodecyl-sulfate ratio and the interlayer spacing in the lamellar liquid crystal showed a pronounced reduction for initial addition of the calcium soap. © 1984
Replication Analysis in Exploratory Factor Analysis: What it is and why it makes your analysis better
Exploratory Factor Analysis (EFA) is a powerful and commonly-used tool for investigating the underlying variable structure of a psychometric instrument. However, there is much controversy in the social sciences with regard to the techniques used in EFA (Ford, MacCallum, & Tait, 1986; Henson & Roberts, 2006) and the reliability of the outcome. Simulations by Costello and Osborne (2005), for example, demonstrate how poorly some EFA analyses replicate, even with clear underlying factor structures and large samples. Thus, we argue that researchers should routinely examine the stability or volatility of their EFA solutions to gain more insight into the robustness of their solutions and insight into how to improve their instruments while still at the exploratory stage of development. Accessed 13,498 times on https://pareonline.net from November 01, 2012 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right
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Replication Analysis in Exploratory Factor Analysis: What it is and why it makes your analysis better
Exploratory Factor Analysis (EFA) is a powerful and commonly-used tool for investigating the underlying variable structure of a psychometric instrument. However, there is much controversy in the social sciences with regard to the techniques used in EFA (Ford, MacCallum, & Tait, 1986; Henson & Roberts, 2006) and the reliability of the outcome. Simulations by Costello and Osborne (2005), for example, demonstrate how poorly some EFA analyses replicate, even with clear underlying factor structures and large samples. Thus, we argue that researchers should routinely examine the stability or volatility of their EFA solutions to gain more insight into the robustness of their solutions and insight into how to improve their instruments while still at the exploratory stage of development. Accessed 13,498 times on https://pareonline.net from November 01, 2012 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right
Type I interferon receptor deficiency in dendritic cells facilitates systemic murine norovirus persistence despite enhanced adaptive immunity
In order for a virus to persist, there must be a balance between viral replication and immune clearance. It is commonly believed that adaptive immunity drives clearance of viral infections and, thus, dysfunction or viral evasion of adaptive immunity is required for a virus to persist. Type I interferons (IFNs) play pleiotropic roles in the antiviral response, including through innate control of viral replication. Murine norovirus (MNoV) replicates in dendritic cells (DCs) and type I IFN signaling in DCs is important for early control of MNoV replication. We show here that the non-persistent MNoV strain CW3 persists systemically when CD11c positive DCs are unable to respond to type I IFN. Persistence in this setting is associated with increased early viral titers, maintenance of DC numbers, increased expression of DC activation markers and an increase in CD8 T cell and antibody responses. Furthermore, CD8 T cell function is maintained during the persistent phase of infection and adaptive immune cells from persistently infected mice are functional when transferred to Rag1-/- recipients. Finally, increased early replication and persistence are also observed in mixed bone marrow chimeras where only half of the CD11c positive DCs are unable to respond to type I IFN. These findings demonstrate that increased early viral replication due to a cell-intrinsic innate immune deficiency is sufficient for persistence and a functional adaptive immune response is not sufficient for viral clearance
The life history and ecology of the Pink-tailed Worm-lizard Aprasia parapulchella Kluge a review
This review synthesises research on the Pink-tailed Worm-lizard Aprasia parapukhella - a threatened species with life-history traits and habitat and dietary preferences that make it particularly vulnerable to decline. Further information on the ecology of A. parapukhella is required in order to develop effective approaches to conservation and management, particularly given the conservation status of the species. Aprasia parapukhella is a dietary specialist living in the burrows of small ants, the eggs and larvae of which it preys upon. It is late maturing (adult size probably attained in the third or fourth year of life), has a small clutch, is thought to be longlived and has specific habitat preferences. It has a strong association with landscapes that are characterised by outcroppings of lightly-embedded surface rocks.The lizard is associated with a particular suite of ant species and ground cover tending towards open native vegetation (grasses and shrubs) at most sites, but with regional differences. Although the highest densities have been recorded in areas without tree cover, the species has also been found in open-forest and woodland.The relative density of populations and the snout-vent length and weight of specimens reveal regional differences, suggesting that further analysis of the genetic status of the population across its range is warranted. There is still much to learn about the ecology of the species, in particular with respect to movement, breeding, dispersal and the relationship between lizards and ants. Further survey for new populations remains a key priority
Identification of Histamine H3 Receptor Ligands Using a New Crystal Structure Fragment-based Method
Persistent enteric murine norovirus infection is associated with functionally suboptimal virus-specific CD8 T cell responses
Norovirus (NV) gastroenteritis is a major contributor to global morbidity and mortality, yet little is known about immune mechanisms leading to NV control. Previous studies using the murine norovirus (MNV) model have established a key role for T cells in MNV clearance. Despite these advances, important questions remain regarding the magnitude, location, and dynamics of the MNV-specific T cell response. To address these questions, we identified MNV-specific major histocompatibility complex (MHC) class I immunodominant epitopes using an overlapping peptide screen. One of these epitopes (amino acids 519 to 527 of open reading frame 2 [ORF2(519-527)]) was highly conserved among all NV genogroups. Using MHC class I peptide tetramers, we tracked MNV-specific CD8 T cells in lymphoid and mucosal sites during infection with two MNV strains with distinct biological behaviors, the acutely cleared strain CW3 and the persistent strain CR6. Here, we show that enteric MNV infection elicited robust T cell responses primarily in the intestinal mucosa and that MNV-specific CD8 T cells dynamically regulated the expression of surface molecules associated with activation, differentiation, and homing. Furthermore, compared to MNV-CW3 infection, chronic infection with MNV-CR6 resulted in fewer and less-functional CD8 T cells, and this difference was evident as early as day 8 postinfection. Finally, MNV-specific CD8 T cells were capable of reducing the viral load in persistently infected Rag1(−/−) mice, suggesting that these cells are a crucial component of NV immunity. Collectively, these data provide fundamental new insights into the adaptive immune response to two closely related NV strains with distinct biological behaviors and bring us closer to understanding the correlates of protective antiviral immunity in the intestine
Superfluid to solid crossover in a rotating Bose-Einstein condensed gas
The properties of a rotating Bose-Einstein condensate confined in a prolate
cylindrically symmetric trap are explored both analytically and numerically. As
the rotation frequency increases, an ever greater number of vortices are
energetically favored. Though the cloud anisotropy and moment of inertia
approach those of a classical fluid at high frequencies, the observed vortex
density is consistently lower than the solid-body estimate. Furthermore, the
vortices are found to arrange themselves in highly regular triangular arrays,
with little distortion even near the condensate surface. These results are
shown to be a direct consequence of the inhomogeneous confining potential.Comment: 4+e pages, 5 embedded figures, revte
Redshift Filtering by Swift Apparent X-ray Column Density
We remark on the utility of an observational relation between the absorption
column density in excess of the Galactic absorption column density, , and redshift, z, determined from
all 55 Swift-observed long bursts with spectroscopic redshifts as of 2006
December. The absorption column densities, , are determined
from powerlaw fits to the X-ray spectra with the absorption column density left
as a free parameter. We find that higher excess absorption column densities
with cm are only present in bursts
with redshifts z2. Low absorption column densities with cm appear preferentially in high-redshift bursts. Our
interpretation is that this relation between redshift and excess column density
is an observational effect resulting from the shift of the source rest-frame
energy range below 1 keV out of the XRT observable energy range for high
redshift bursts. We found a clear anti-correlation between
and z that can be used to estimate the range of the maximum redshift of an
afterglow. A critical application of our finding is that rapid X-ray
observations can be used to optimize the instrumentation used for ground-based
optical/NIR follow-up observations. Ground-based spectroscopic redshift
measurements of as many bursts as possible are crucial for GRB science.Comment: revised version including updates and the referee's comments,
accepted for publication in the Astronomical Journal, 12 pages, 2 figures, 2
tables - v3 contains an update on the reference lis
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