2,602 research outputs found
Flow cytometric evaluation of red blood cells transformed with variable amounts of synthetic A and B glycolipids
Background: According to national guidelines or directives, monoclonal
ABO reagents may be required to detect Ax and B weak subgroup red blood
cells (RBCs). Many routine laboratories do not have access to naturallyoccurring
ABO subgroups that can be used as weak controls for these
reagents. Group O RBCs modified with synthetic analogs of blood group A
and/or B glycolipids (KODE technology) to mimic weak ABO subgroups
could be used for quality control purposes.
Aim: Extensive serological testing of KODE RBCs has previously been
performed. An extended evaluation of KODE RBCs using flow cytometry
was performed to explore the correlation between the concentrations of
synthetic glycolipids and A/B site density of the resulting RBCs. The aim of
this study was to examine if KODE RBCs mimic the distinct flow cytometric
patterns of naturally-occurring ABO subgroups.
Material and Methods: KODE RBCs were prepared according to a previously
decribed procedure [Frame et al., Transfusion 2007; 47: 876–82].
RBCs were modified with 15 different concentrations of synthetic glycolipids,
ranging from 1 mg/mL to 60 ng/mL for KODE-A and 5 mg/mL to
0.3 lg/mL for KODE-B. The concentration was decreased by doubling
dilution steps. Sensitive and specific flow cytometry [Hult & Olsson.
Transfusion 2006; 9S: 32A] was used to characterize and semiquantify the
synthetic A and B antigen levels on RBCs. Relevant control RBCs (A1, A2,
Ax, B, Bweak and O) were included in each run. For both KODE-A and KODE-B RBCs, repeat samples were produced for four selected concentrations
and all KODE batches were tested in triplicate.
Results: Flow cytometric testing of KODE RBCs modified with high
concentrations of synthetic glycolipids revealed a uniform and even
distribution of antigens in the cell population as shown by a single
narrow peak in the FACS histograms. When lower concentrations were
used, peaks tended to broaden to a pattern found in Ax and most B
subgroups indicating a more variable antigen site density on the cells in
the population. The concentrations of synthetic glycolipids that produced
KODE cells that resembled the naturally-occurring subgroup control RBCs
used in this study are ~2–4 lg/mL for KODE-A and ~10 lg/mL for KODEB.
Repeat testing demonstrated good correlation between flow cytometric
runs.
Discussion and Conclusion: Using very low amounts of synthetic
glycolipids, KODE-A and KODE-B RBCs can be made to mimic Ax and
Bweak subgroup control RBCs, respectively, according to this flow
cytometry method. With higher concentrations of synthetic glycolipids, the
KODE RBCs demonstrated a more uniform and even distribution of antigens
among the cells. This is in contrast to naturally-occurring subgroups
in which some cells express almost no A or B antigen whilst others have
close to normal levels. The reason for this is unknown. KODE RBCs obviously
lack A carrying glycoproteins but it is not fully understood to what
extent glycolipid versus glycoprotein epitopes contribute to the phenotype
of weak subgroups.
This study indicates that KODE RBCs with weak expression of A and/or B
antigen have characteristics compatible with use as quality controls for
monoclonal ABO reagents and could be a valuable addition in the
serological laboratory
Dual Identities inside the Gluon and the Graviton Scattering Amplitudes
Recently, Bern, Carrasco and Johansson conjectured dual identities inside the
gluon tree scattering amplitudes. In this paper, we use the properties of the
heterotic string and open string tree scattering amplitudes to refine and
derive these dual identities. These identities can be carried over to loop
amplitudes using the unitarity method. Furthermore, given the -gluon (as
well as gluon-gluino) tree amplitudes, -graviton (as well as
graviton-gravitino) tree scattering amplitudes can be written down immediately,
avoiding the derivation of Feynman rules and the evaluation of Feynman diagrams
for graviton scattering amplitudes.Comment: 43 pages, 3 figures; typos corrected, a few points clarified
A Self-Reference False Memory Effect in the DRM Paradigm: Evidence from Eastern and Western Samples
It is well established that processing information in relation to oneself (i.e., selfreferencing) leads to better memory for that information than processing that same information in relation to others (i.e., other-referencing). However, it is unknown whether self-referencing also leads to more false memories than other-referencing. In the current two experiments with European and East Asian samples, we presented participants the Deese-Roediger/McDermott (DRM) lists together with their own name or other people’s name (i.e., “Trump” in Experiment 1 and “Li Ming” in Experiment 2). We found consistent results across the two experiments; that is, in the self-reference condition, participants had higher true and false memory rates compared to those in the other-reference condition. Moreover, we found that selfreferencing did not exhibit superior mnemonic advantage in terms of net accuracy compared to other-referencing and neutral conditions. These findings are discussed in terms of theoretical frameworks such as spreading activation theories and the fuzzytrace theory. We propose that our results reflect the adaptive nature of memory in the sense that cognitive processes that increase mnemonic efficiency may also increase susceptibility to associative false memories
Inhalation characteristics of asthma patients, COPD patients and healthy volunteers with the Spiromax® and Turbuhaler® devices: a randomised, cross-over study.
BACKGROUND: Spiromax® is a novel dry-powder inhaler containing formulations of budesonide plus formoterol (BF). The device is intended to provide dose equivalence with enhanced user-friendliness compared to BF Turbuhaler® in asthma and chronic obstructive pulmonary disease (COPD). The present study was performed to compare inhalation parameters with empty versions of the two devices, and to investigate the effects of enhanced training designed to encourage faster inhalation. METHODS: This randomised, open-label, cross-over study included children with asthma (n = 23), adolescents with asthma (n = 27), adults with asthma (n = 50), adults with COPD (n = 50) and healthy adult volunteers (n = 50). Inhalation manoeuvres were recorded with each device after training with the patient information leaflet (PIL) and after enhanced training using an In-Check Dial device. RESULTS: After PIL training, peak inspiratory flow (PIF), maximum change in pressure (∆P) and the inhalation volume (IV) were significantly higher with Spiromax than with the Turbuhaler device (p values were at least <0.05 in all patient groups). After enhanced training, numerically or significantly higher values for PIF, ∆P, IV and acceleration remained with Spiromax versus Turbuhaler, except for ∆P in COPD patients. After PIL training, one adult asthma patient and one COPD patient inhaled <30 L/min through the Spiromax compared to one adult asthma patient and five COPD patients with the Turbuhaler. All patients achieved PIF values of at least 30 L/min after enhanced training. CONCLUSIONS: The two inhalers have similar resistance so inhalation flows and pressure changes would be expected to be similar. The higher flow-related values noted for Spiromax versus Turbuhaler after PIL training suggest that Spiromax might have human factor advantages in real-world use. After enhanced training, the flow-related differences between devices persisted; increased flow rates were achieved with both devices, and all patients achieved the minimal flow required for adequate drug delivery. Enhanced training could be useful, especially in COPD patients
Masculinity as Governance: police, public service and the embodiment of authority, c. 1700-1850
About the book: Public Men offers an introduction to an exciting new field: the history of masculinities in the political domain and will be essential reading for students and specialists alike with interests in gender or political culture. By building upon new work on gender and political culture, these new case studies explore the gendering of the political domain and the masculinities of the men who have historically dominated it. As such, Public Men is a major contribution to our understanding of the history of Britain between the Eighteenth and the Twentieth centuries
The Cosmic Infrared Background: Measurements and Implications
The cosmic infrared background records much of the radiant energy released by
processes of structure formation that have occurred since the decoupling of
matter and radiation following the Big Bang. In the past few years, data from
the Cosmic Background Explorer mission provided the first measurements of this
background, with additional constraints coming from studies of the attenuation
of TeV gamma-rays. At the same time there has been rapid progress in resolving
a significant fraction of this background with the deep galaxy counts at
infrared wavelengths from the Infrared Space Observatory instruments and at
submillimeter wavelengths from the Submillimeter Common User Bolometer Array
instrument. This article reviews the measurements of the infrared background
and sources contributing to it, and discusses the implications for past and
present cosmic processes.Comment: 61 pages, incl. 9 figures, to be published in Annual Reviews of
Astronomy and Astrophysics, 2001, Vol. 3
Differences in osmotolerance in freshwater and brackish water populations of Theodoxus fluviatilis (Gastropoda: Neritidae) are associated with differential protein expression
The euryhaline gastropod Theodoxus fluviatilis is found in northern Germany in freshwater or in brackish water habitats in the Baltic Sea. Previous studies have revealed that individuals from both habitats are not distinguishable by morphological characters or by sequence comparison of DNA encoding 16S RNA or cytochrome C. As reported in this study, animals collected in the two habitats differ substantially in their physiological ability to adapt to different salinities. Comparison of accumulation rates of ninhydrin-positive substances (NPS) in foot muscle upon transfer of animals to higher medium salinities revealed that brackish water animals were perfectly able to mobilize NPS, while freshwater animals had only limited ability to do so. In an attempt to explore whether this difference in physiology may be caused by genetic differentiation, we compared protein expression patterns of soluble foot muscle proteins using 2D gel electrophoresis and silver staining. Of the 40 consistently detected protein spots, 27 showed similar levels in protein expression in animals collected from freshwater or brackish water habitats, respectively. In 12 spots, however, protein concentration was higher in brackish water than in freshwater animals. In four of these spots, expression levels followed increases or decreases in medium salinities. In a different set of 4 of these 12 spots, protein levels were always higher in brackish water as compared to freshwater animals, regardless of their physiological situation (14 days in artificial pond water or in medium with a salinity of 16‰). The remaining 4 of the 12 spots had complex expression patterns. Protein levels of the remaining single spot were generally higher in freshwater animals than in brackish water animals. These expression patterns may indicate that freshwater and brackish water animals of T. fluviatilis belong to different locally adapted populations with subtle genetic differentiation
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The behavioural effect of electronic home energy reports: Evidence from a randomised field trial in the United States
Behavioural interventions, such as informational nudges, have become an increasingly popular strategy in demand-side energy management. In particular, home energy reports (HERs) have been used to induce behavioural change among residential consumers. These HERs typically provide peer comparisons of energy use and information about energy savings opportunities. Despite the growing prevalence of HERs and a shift from postal to electronic delivery of HERs, the experimental evidence base of their effectiveness comes primarily from HERs delivered by post from a single vendor (Opower). Whether that evidence generalises to other programmes and to the electronic delivery of HERs is unclear. This paper reports new evidence for HER effectiveness from a 12-month field experiment with approximately 9,000 households that tested electronic HER programme in a deregulated American residential electricity market. Despite high non-compliance with HER delivery, the programme reduced household electricity consumption by 2.9%, 95% CI [-5.0%, -0.76%]. This estimated reduction is consistent with prior estimated impacts of HERs delivered by post and implies electronic HERs are at least as effective as reports delivered by post in reducing electricity consumption, while they are administered at a lower cost
Frontal white matter tracts sustaining speech production in primary progressive aphasia
In primary progressive aphasia (PPA), speech and language difficulties are caused by neurodegeneration of specific brain networks. In the nonfluent/agrammatic variant (nfvPPA), motor speech and grammatical deficits are associated with atrophy in a left fronto-insular-striatal network previously implicated in speech production. In vivo dissection of the crossing white matter (WM) tracts within this "speech production network" is complex and has rarely been performed in health or in PPA. We hypothesized that damage to these tracts would be specific to nfvPPA and would correlate with differential aspects of the patients' fluency abilities. We prospectively studied 25 PPA and 21 healthy individuals who underwent extensive cognitive testing and 3 T MRI. Using residual bootstrap Q-ball probabilistic tractography on high angular resolution diffusion-weighted imaging (HARDI), we reconstructed pathways connecting posterior inferior frontal, inferior premotor, insula, supplementary motor area (SMA) complex, striatum, and standard ventral and dorsal language pathways. We extracted tract-specific diffusion tensor imaging (DTI) metrics to assess changes across PPA variants and perform brain-behavioral correlations. Significant WM changes in the left intrafrontal and frontostriatal pathways were found in nfvPPA, but not in the semantic or logopenic variants. Correlations between tract-specific DTI metrics with cognitive scores confirmed the specific involvement of this anterior-dorsal network in fluency and suggested a preferential role of a posterior premotor-SMA pathway in motor speech. This study shows that left WM pathways connecting the speech production network are selectively damaged in nfvPPA and suggests that different tracts within this system are involved in subcomponents of fluency. These findings emphasize the emerging role of diffusion imaging in the differential diagnosis of neurodegenerative diseases
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