715 research outputs found
Identifying distinct latent classes of pitch-shift response consistency: Evidence from manipulating the predictability of shift direction
Auditory feedback plays an important role in regulating our vocal pitch. When pitch shifts suddenly appear in auditory feedback, the majority of the responses are opposing, correcting for the mismatch between perceived pitch and actual pitch. However, research has indicated that following responses to auditory perturbation could be common. This study attempts to explore the ways individual speakers would respond to pitch perturbation (using an opposing response or a following response) from trial to trial. Thirty-six native speakers of Mandarin produced the vowel /a/ while receiving perturbed pitch at a random time (500 ~ 700 ms) after vocal onset for a duration of 200 ms. Three blocks of 30 trials that differed in the pitch-shift stimulus direction were recorded in a randomized order: (a) the down-only condition where pitch was shifted downwards 250 cents; (b) the up-only condition where pitch was shifted upwards 250 cents; and (c) the random condition where downshifts and upshifts occurred randomly and were equally likely. The participants were instructed to ignore the pitch shifts. Results from the latent class analysis show that at the individual level across trials, 57% of participants were switchers, 28% were opposers, and 15% were followers. Our results support that speakers produce a mix of opposing and following responses when they respond to perturbed pitch. Specifically, the proportion of followers was conditional on the expectancy of pitch-shift stimulus direction: More followers were observed when the pitch-shift stimulus direction was predictable. Closer inspection of the levels of response consistency in different time phases shows that a particular mechanism (opposing or following) was initially implemented; the two mechanisms may alternate in the middle phase; and then finally, the pitch-shift response was featured as a particular mechanism near the end phase
Analysis of clinical outcomes in pediatric bacterial meningitis focusing on patients without cerebrospinal fluid pleocytosis
BackgroundCerebrospinal fluid (CSF) cell count and biochemical examinations and cultures form the basis for the diagnosis of bacterial meningitis. However, some patients do not have typical findings and are at a higher risk of being missed or having delayed treatment. To better understand the correlation between CSF results and outcomes, we evaluated CSF data focusing on the patients with atypical findings.MethodsThis study enrolled CSF culture-proven bacterial meningitis patients aged from 1 month to 18 years in a medical center. The patients were divided into “normal” and “abnormal” groups for each laboratory result and in combination. The correlations between the laboratory results and the outcomes were analyzed.ResultsA total of 175 children with confirmed bacterial meningitis were enrolled. In CSF examinations, 16.2% of patients had normal white blood cell counts, 29.5% had normal glucose levels, 24.5% had normal protein levels, 10.2% had normal results in two items, and 8.6% had normal results in all three items. In logistic regression analysis, a normal CSF leukocyte count and increased CSF protein level were related to poor outcomes. Patients with meningitis caused by Streptococcus pneumoniae and hyponatremia were at a higher risk of mortality and the development of sequelae.ConclusionsIn children with bacterial meningitis, nontypical CSF findings and, in particular, normal CSF leukocyte count and increased protein level may indicate a worse prognosis
To switch or not? Effects of spokes-character urgency during the social app loading process and app type on user switching intention
Users of mobile phone applications (apps) often have to wait for the pages of apps to load, a process that substantially affects user experience. Based on the Attentional Gate Model and Emotional Contagion Theory, this paper explores the effects of the urgency expressed by a spokes-character’s movement in the loading page of a social app the app type on users’ switching intention through two studies. In Study 1 (N = 173), the results demonstrated that for a hedonic-orientated app, a high-urgency (vs. low-urgency) spokes-character resulted in a lower switching intention, whereas the opposite occurred for a utilitarian-orientated app. We adopted a similar methodology in Study 2 (N = 182) and the results showed that perceived waiting time mediated the interaction effect demonstrated in Study 1. Specifically, for the hedonic-orientated (vs. utilitarian-orientated) social app, the high-urgency (vs. low-urgency) spokes-character made participants estimate a shorter perceived waiting time, which induces a lower user switching intention. This paper contributes to the literature on emotion, spokes-characters, and human–computer interaction, which extends an enhanced understanding of users’ perception during loading process and informs the design of spokes-characters for the loading pages of apps
Mechanical Characterization of Rabbit Pulmonary Vein Sleeves in In Vitro Intact Ring Preparation
BackgroundPulmonary vein (PV) sleeves, composed of cardiomyocytes, play certain roles in arrhythmogenesis. In the literature, it has been frequently reported that PV sleeves possess intrinsic spontaneous pacemaking activity and triggered activity in normal dogs and rabbits. In contrast, other research groups presented totally opposite findings which showed absence of such pacemakers in dogs, rabbits and rats. The present study was designed to clarify this puzzle and contradiction.MethodsA novel methodology using in vitro experimentation was used to examine the electromechanical activity of whole segments of PV sleeves. The ring preparation was composed of a small piece of left atrial (LA) free wall, PV ostium and sleeve from rabbits. A circumferential contraction of the PV sleeve was measured when the preparation was electrically driven from the LA free wall. Mechanical force of the ring preparation was measured using a force transducer. The action potentials were recorded using conventional intracellular recording technique in strip preparation.ResultsIn 15 rabbits, no spontaneous pacemaking activity or triggered activity was found in the in vitro ring preparation of PV sleeve. The circumferential contraction of PV sleeves was external calcium-dependent. Frequency-force relation displayed a negative staircase at 0.1–0.5 Hz and a positive staircase at 1–5 Hz. Post-rest potentiation was prominent between 15 s and 120 s. Intracellular action potential recording did not display any automaticity or triggered activity in PV sleeves.ConclusionIn an intact ring preparation of rabbit PV sleeves, intrinsic spontaneous pacemaking activity or triggered activity was not found
Deconfined quantum criticality and emergent symmetry in SrCu2(BO3)2
The deconfined quantum critical point (DQCP) represents a paradigm shift in
theories of quantum matter, presenting a "beyond Landau" scenario for
order-order transitions. Its experimental realization, however, has remained
elusive. Here we demonstrate by high-pressure 11B NMR measurements on the
quantum magnet SrCu2(BO3)2 that the magnetic field induced plaquette-singlet to
antiferromagnetic transition above 1.8 GPa is proximate to a DQCP. We find a
weak first-order transition between the two phases at a remarkably low
temperature, Tc~0.07 K. Above Tc we observe quantum critical scaling at the
highest pressure, 2.4 GPa. We explain the low first-order Tc values by a
DQCP-induced emergent O(3) symmetry that is broken in the coexistence state.
Our findings take the DQCP from a theoretical concept to a concrete
experimental platform
Label-free quantitative proteomics of CD133-positive liver cancer stem cells
Abstract
Background
CD133-positive liver cancer stem cells, which are characterized by their resistance to conventional chemotherapy and their tumor initiation ability at limited dilutions, have been recognized as a critical target in liver cancer therapeutics. In the current work, we developed a label-free quantitative method to investigate the proteome of CD133-positive liver cancer stem cells for the purpose of identifying unique biomarkers that can be utilized for targeting liver cancer stem cells. Label-free quantitation was performed in combination with ID-based Elution time Alignment by Linear regression Quantitation (IDEAL-Q) and MaxQuant.
Results
Initially, IDEAL-Q analysis revealed that 151 proteins were differentially expressed in the CD133-positive hepatoma cells when compared with CD133-negative cells. We then analyzed these 151 differentially expressed proteins by MaxQuant software and identified 10 significantly up-regulated proteins. The results were further validated by RT-PCR, western blot, flow cytometry or immunofluorescent staining which revealed that prominin-1, annexin A1, annexin A3, transgelin, creatine kinase B, vimentin, and EpCAM were indeed highly expressed in the CD133-positive hepatoma cells.
Conclusions
These findings confirmed that mass spectrometry-based label-free quantitative proteomics can be used to gain insights into liver cancer stem cells.http://deepblue.lib.umich.edu/bitstream/2027.42/113089/1/12953_2012_Article_407.pd
Serologic Status for Pandemic (H1N1) 2009 Virus, Taiwan
We studied preexisting immunity to pandemic (H1N1) 2009 virus in persons in Taiwan. A total of 18 (36%) of 50 elderly adults in Taiwan born before 1935 had protective antibodies against currently circulating pandemic (H1N1) 2009 virus. Seasonal influenza vaccines induced antibodies that did not protect against pandemic (H1N1) 2009 virus
- …