1,192 research outputs found
A Compromise between Neutrino Masses and Collider Signatures in the Type-II Seesaw Model
A natural extension of the standard gauge
model to accommodate massive neutrinos is to introduce one Higgs triplet and
three right-handed Majorana neutrinos, leading to a neutrino mass
matrix which contains three sub-matrices ,
and . We show that three light Majorana neutrinos (i.e., the mass
eigenstates of , and ) are exactly massless in this
model, if and only if
exactly holds. This no-go theorem implies that small but non-vanishing neutrino
masses may result from a significant but incomplete cancellation between
and terms in the Type-II
seesaw formula, provided three right-handed Majorana neutrinos are of TeV and experimentally detectable at the LHC. We propose three simple
Type-II seesaw scenarios with the flavor symmetry to
interpret the observed neutrino mass spectrum and neutrino mixing pattern. Such
a TeV-scale neutrino model can be tested in two complementary ways: (1)
searching for possible collider signatures of lepton number violation induced
by the right-handed Majorana neutrinos and doubly-charged Higgs particles; and
(2) searching for possible consequences of unitarity violation of the neutrino mixing matrix in the future long-baseline neutrino oscillation
experiments.Comment: RevTeX 19 pages, no figure
ciliaFA : a research tool for automated, high-throughput measurement of ciliary beat frequency using freely available software
Background: Analysis of ciliary function for assessment of patients suspected of primary ciliary dyskinesia (PCD) and
for research studies of respiratory and ependymal cilia requires assessment of both ciliary beat pattern and beat
frequency. While direct measurement of beat frequency from high-speed video recordings is the most accurate and
reproducible technique it is extremely time consuming. The aim of this study was to develop a freely available
automated method of ciliary beat frequency analysis from digital video (AVI) files that runs on open-source software
(ImageJ) coupled to Microsoft Excel, and to validate this by comparison to the direct measuring high-speed video
recordings of respiratory and ependymal cilia. These models allowed comparison to cilia beating between 3 and 52 Hz.
Methods: Digital video files of motile ciliated ependymal (frequency range 34 to 52 Hz) and respiratory epithelial cells
(frequency 3 to 18 Hz) were captured using a high-speed digital video recorder. To cover the range above between 18
and 37 Hz the frequency of ependymal cilia were slowed by the addition of the pneumococcal toxin pneumolysin.
Measurements made directly by timing a given number of individual ciliary beat cycles were compared with those
obtained using the automated ciliaFA system.
Results: The overall mean difference (± SD) between the ciliaFA and direct measurement high-speed digital imaging
methods was −0.05 ± 1.25 Hz, the correlation coefficient was shown to be 0.991 and the Bland-Altman limits of
agreement were from −1.99 to 1.49 Hz for respiratory and from −2.55 to 3.25 Hz for ependymal cilia.
Conclusions: A plugin for ImageJ was developed that extracts pixel intensities and performs fast Fourier
transformation (FFT) using Microsoft Excel. The ciliaFA software allowed automated, high throughput measurement of
respiratory and ependymal ciliary beat frequency (range 3 to 52 Hz) and avoids operator error due to selection bias. We
have included free access to the ciliaFA plugin and installation instructions in Additional file 1 accompanying this
manuscript that other researchers may use
Lithium intoxication related multiple temporary ecg changes: A case report
Lithium is a widely used mood stabilizer, which may cause cardiac side effects. In this article, we present the case of a 39-year-old woman who had presented with pre-syncope and developed multiple ECG abnormalities that are caused by lithium intoxication and are disappeared after hemodialysis
The tensions of defining and developing thought leadership within knowledge-intensive firms
This is the final version. Available on open access from Emerald via the DOI in this record.Design/methodology/approach We review the academic and practitioner literature on thought leadership to provide a rich oversight of how it is defined and can be understood by separating inputs, creation processes and outcomes. We also draw on qualitative data from 12 in-depth interviews with senior leaders of professional service firms. Purpose A major part of knowledge management for knowledge-intensive firms such as professional service firms is the increasing focus on thought leadership. Despite being a well-known term, it is poorly defined and analysed in the academic and practitioner literature. As a result, we seek to answer three questions. First, what is thought leadership? Second, what tensions exist when seeking to create thought leadership in knowledge-based organisations? Third, what further research is needed about thought leadership? We call for cross-disciplinary and academic-practitioner approaches to understanding the field of thought leadership. Findings Through analysing and building on previous understandings of the concept, we redefine thought leadership as: “Knowledge from a trusted, eminent and authoritative source that is actionable and provides valuable solutions for stakeholders.” We find and explore nine tensions that developing thought leadership creates and propose a framework for understanding how to engage with thought leadership at the industry/macro, organisational/meso and individual/micro levels. We propose a research agenda based on testing propositions derived from new theories to explain thought leadership, including leadership, reducing risk, signaling quality, and managing social networks, as well as examining the suggested ways to resolve different tensions. Originality/value We are the first to separate out thought leadership from its inputs, creation processes and outcomes. We show new organisational paradoxes within thought leadership and show how they can play out at different levels of analysis when implementing a thought leadership strategy. This work on thought leadership is set in a relatively under-explored context for knowledge management researchers, namely, knowledge-intensive professional service firms
Gender differences in the impact of family background on leaving the parental home
We address the question to what extent characteristics of the family of origin influence the timing of leaving the parental home and to what extent these effects differ between men and women. We use data from the Netherlands Kinship Panel Study to examine the effects of parental resources, atmosphere in the family of origin and family structure on leaving home to live without a partner and leaving home to live with a partner. The results indicate that a pleasant atmosphere in the parental home decreases the risk of leaving home and living in stepfamilies or single-parent families increases this risk. The availability of parental resources leads to a decreased risk of leaving home at young ages, but an increased risk at later ages. Many of these effects are found for both men and women and for both pathways out of the home. Furthermore, we find evidence that women are affected more strongly by family background characteristics than men are
The antisaccade task as an index of sustained goal activation in working memory: modulation by nicotine
The antisaccade task provides a laboratory analogue of situations in which execution of the correct behavioural response requires the suppression of a more prepotent or habitual response. Errors (failures to inhibit a reflexive prosaccade towards a sudden onset target) are significantly increased in patients with damage to the dorsolateral prefrontal cortex and patients with schizophrenia. Recent models of antisaccade performance suggest that errors are more likely to occur when the intention to initiate an antisaccade is insufficiently activated within working memory. Nicotine has been shown to enhance specific working memory processes in healthy adults. MATERIALS AND METHODS: We explored the effect of nicotine on antisaccade performance in a large sample (N = 44) of young adult smokers. Minimally abstinent participants attended two test sessions and were asked to smoke one of their own cigarettes between baseline and retest during one session only. RESULTS AND CONCLUSION: Nicotine reduced antisaccade errors and correct antisaccade latencies if delivered before optimum performance levels are achieved, suggesting that nicotine supports the activation of intentions in working memory during task performance. The implications of this research for current theoretical accounts of antisaccade performance, and for interpreting the increased rate of antisaccade errors found in some psychiatric patient groups are discussed
Testing the cognitive-behavioural maintenance models across DSM-5 bulimic-type eating disorder diagnostic groups: A multi-centre study
The original cognitive-behavioural (CB) model of bulimia nervosa, which provided the basis for the widely used CB therapy, proposed that specific dysfunctional cognitions and behaviours maintain the disorder. However, amongst treatment completers, only 40–50 % have a full and lasting response. The enhanced CB model (CB-E), upon which the enhanced version of the CB treatment was based, extended the original approach by including four additional maintenance factors. This study evaluated and compared both CB models in a large clinical treatment seeking sample (N = 679), applying both DSM-IV and DSM-5 criteria for bulimic-type eating disorders. Application of the DSM-5 criteria reduced the number of cases of DSM-IV bulimic-type eating disorders not otherwise specified to 29.6 %. Structural equation modelling analysis indicated that (a) although both models provided a good fit to the data, the CB-E model accounted for a greater proportion of variance in eating-disordered behaviours than the original one, (b) interpersonal problems, clinical perfectionism and low self-esteem were indirectly associated with dietary restraint through over-evaluation of shape and weight, (c) interpersonal problems and mood intolerance were directly linked to binge eating, whereas restraint only indirectly affected binge eating through mood intolerance, suggesting that factors other than restraint may play a more critical role in the maintenance of binge eating. In terms of strength of the associations, differences across DSM-5 bulimic-type eating disorder diagnostic groups were not observed. The results are discussed with reference to theory and research, including neurobiological findings and recent hypotheses
Get Organised: The 'Do's' Preceding Successful Field Research
There is no shortage in the political science literature on field research regarding issues of research design, methodology, and data evaluation. Yet, the practical and organisational intricacies that precede successful fieldwork are frequently overlooked. This lack of methodical advice may be due to the impression that field research is highly contextual, and so case-specific that general guidelines, which apply to all field research endeavours alike, are inconceivable. While we acknowledge the organisational complexity of field research, we disagree with the notion that the preparatory dimension of fieldwork is by necessity unique for every undertaking. Rather, recommendations for common challenges that occur during the preparation and organisation phase of a field trip can be identified and formulated. Consequently, we present and discuss ten organisational ?do's? preceding successful field research. Current graduate students and future field researchers will regard these ten pointers as useful hints in the organisation of their own endeavour. While the list is by no means exhaustive, the ten recommendations will lower the organisational entry costs of aspiring field researchers, and enable them to hit the ground running when arriving in the field
Chromosomal-level assembly of the Asian Seabass genome using long sequence reads and multi-layered scaffolding
We report here the ~670 Mb genome assembly of the Asian seabass (Lates calcarifer), a tropical marine teleost. We used long-read sequencing augmented by transcriptomics, optical and genetic mapping along with shared synteny from closely related fish species to derive a chromosome-level assembly with a contig N50 size over 1 Mb and scaffold N50 size over 25 Mb that span ~90% of the genome. The population structure of L. calcarifer species complex was analyzed by re-sequencing 61 individuals representing various regions across the species' native range. SNP analyses identified high levels of genetic diversity and confirmed earlier indications of a population stratification comprising three clades with signs of admixture apparent in the South-East Asian population. The quality of the Asian seabass genome assembly far exceeds that of any other fish species, and will serve as a new standard for fish genomics
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