268 research outputs found
Music Perception in Dementia.
Despite much recent interest in music and dementia, music perception has not been widely studied across dementia syndromes using an information processing approach. Here we addressed this issue in a cohort of 30 patients representing major dementia syndromes of typical Alzheimer's disease (AD, n = 16), logopenic aphasia (LPA, an Alzheimer variant syndrome; n = 5), and progressive nonfluent aphasia (PNFA; n = 9) in relation to 19 healthy age-matched individuals. We designed a novel neuropsychological battery to assess perception of musical patterns in the dimensions of pitch and temporal information (requiring detection of notes that deviated from the established pattern based on local or global sequence features) and musical scene analysis (requiring detection of a familiar tune within polyphonic harmony). Performance on these tests was referenced to generic auditory (timbral) deviance detection and recognition of familiar tunes and adjusted for general auditory working memory performance. Relative to healthy controls, patients with AD and LPA had group-level deficits of global pitch (melody contour) processing while patients with PNFA as a group had deficits of local (interval) as well as global pitch processing. There was substantial individual variation within syndromic groups. Taking working memory performance into account, no specific deficits of musical temporal processing, timbre processing, musical scene analysis, or tune recognition were identified. The findings suggest that particular aspects of music perception such as pitch pattern analysis may open a window on the processing of information streams in major dementia syndromes. The potential selectivity of musical deficits for particular dementia syndromes and particular dimensions of processing warrants further systematic investigation
Efficient and Fast Synthesis of Few-Layer Black Phosphorus via Microwave-Assisted Liquid-Phase Exfoliation
High‐quality, few‐layer black‐phosphorus (BP) flakes are prepared in a common organic solvent with very short processing times using microwave‐assisted liquid‐phase exfoliation. A comprehensive range of analysis, combined with density‐functional theory calculations, confirms that the product prepared using the microwave technique is few‐layer BP with small‐ and large‐area flakes. The suspended exfoliated BP sheets show excellent stability, while samples dispersed onto silicon from the suspensions exhibit low oxidation levels after several days in ambient conditions. This straightforward synthesis method is facile, efficient, and extremely fast, and does not involve use of any surfactant or ultrasonication steps and will facilitate future development of phosphorene research
Two stages of parafoveal processing during reading: Evidence from a display change detection task
We used a display change detection paradigm (Slattery, Angele, & Rayner Human Perception and Performance, 37, 1924–1938 2011) to investigate whether display change detection uses orthographic regularity and whether detection is affected by the processing difficulty of the word preceding the boundary that triggers the display change. Subjects were significantly more sensitive to display changes when the change was from a nonwordlike preview than when the change was from a wordlike preview, but the preview benefit effect on the target word was not affected by whether the preview was wordlike or nonwordlike. Additionally, we did not find any influence of preboundary word frequency on display change detection performance. Our results suggest that display change detection and lexical processing do not use the same cognitive mechanisms. We propose that parafoveal processing takes place in two stages: an early, orthography-based, preattentional stage, and a late, attention-dependent lexical access stage
The functional neuroanatomy of musical memory in Alzheimer's disease
BACKGROUND: Memory for music has attracted much recent interest in Alzheimer's disease but the underlying brain mechanisms have not been defined in patients directly. Here we addressed this issue in an Alzheimer's disease cohort using activation fMRI of two core musical memory systems. METHODS: We studied 34 patients with younger onset Alzheimer's disease led either by episodic memory decline (typical Alzheimer's disease) or by visuospatial impairment (posterior cortical atrophy) in relation to 19 age-matched healthy individuals. We designed a novel fMRI paradigm based on passive listening to melodies that were either previously familiar or unfamiliar (musical semantic memory) and either presented singly or repeated (incidental musical episodic memory). RESULTS: Both syndromic groups showed significant functional neuroanatomical alterations relative to the healthy control group. For musical semantic memory, disease-associated activation group differences were localised to right inferior frontal cortex (reduced activation in the group with memory-led Alzheimer's disease); while for incidental musical episodic memory, disease-associated activation group differences were localised to precuneus and posterior cingulate cortex (abnormally enhanced activation in the syndromic groups). In post-scan behavioural testing, both patient groups had a deficit of musical episodic memory relative to healthy controls whereas musical semantic memory was unimpaired. CONCLUSIONS: Our findings define functional neuroanatomical substrates for the differential involvement of musical semantic and incidental episodic memory in major phenotypes of Alzheimer's disease. The complex dynamic profile of brain activation group differences observed suggests that musical memory may be an informative probe of neural network function in Alzheimer's disease. These findings may guide the development of future musical interventions in dementia
Aurora kinase-C-T191D is constitutively active mutant
<p>Abstract</p> <p>Background</p> <p>Aurora kinases (Aurora-A, B and C) belong to a family of conserved serine/threonine kinases which are key regulators of cell cycle progression. Aurora-A and Aurora-B are expressed in somatic cells and involved in cell cycle regulation while aurora-C is meiotic chromosome passenger protein. As Aurora kinase C is rarely expressed in normal somatic cells and has been found over expressed in many cancer lines. It is suggested that Aurora-C-T191D is not hyperactive mutant.</p> <p>Result</p> <p>Aurora-C-T191D variant form was investigated and compared with wild type. The overexpression of Aurora-C-T191D was observed that it behaves like Aurora-C wild type (aurC-WT). Both Aurora-C-T191D and aurC-WT induce abnormal cell division resulting in centrosome amplification and multinucleation in transiently transfected cells as well as in stable cell lines. Similarly, Aurora-C-T191D and aurC-WT formed foci of colonies when grown on soft agar, indicating that a gain of Aurora-C activity is sufficient to transform cells. Furthermore, we reported that NIH-3 T3 stable cell lines overexpressing Aurora-C-T191D and its wild type partner induced tumour formation when injected into nude mice, demonstrating the oncogenic activity of enzymatically active Aurora kinase C. Interestingly enough tumour aggressiveness was positively correlated with the rate of kinase activity, making Aurora-C a potential anti-cancer therapeutic target.</p> <p>Conclusion</p> <p>These findings proved that Aurora C-T191D is not hyperactive but is constitutively active mutant.</p
Specialist antenatal clinics for women at high risk of preterm birth: a systematic review of qualitative and quantitative research
Background
Preterm birth (PTB) is the leading cause of perinatal morbidity and mortality. Women with previous prenatal loss are at higher risk of preterm birth. A specialist antenatal clinic is considered as one approach to improve maternity and pregnancy outcomes.
Methods
A systematic review of quantitative, qualitative and mixed method studies conducted on women at high risk of preterm birth (PTB). The review primary outcomes were to report on the specialist antenatal clinics effect in preventing or reducing preterm birth, perinatal mortality and morbidity and women’s perceptions and experiences of a specialist clinic whether compared or not compared with standard antenatal care. Other secondary maternal, infant and economic outcomes were also determined. A comprehensive search strategy was carried out in English within electronic databases as far back as 1980. The reviewers selected studies, assessed the quality, and extracted data independently. Results were summarized and tabulated.
Results
Eleven studies fully met the review inclusion criteria, ten were quantitative design studies and only one was a qualitative design study. No mixed method design study was included in the review. All were published after 1989, seven were conducted in the USA and four in the UK. Results from five good to low quality randomised controlled trials (RCTs), all conducted before 1990, did not illustrate the efficacy of the clinic in reducing preterm birth. Whereas results from more recent low quality cohort studies showed some positive neonatal outcomes. Themes from one good quality qualitative study reflected on the emotional and psychological need to reduce anxiety and stress of women referred to such a clinic. Women expressed their negative emotional responses at being labelled as high risk and positive responses to being assessed and treated in the clinic. Women also reported that their partners were struggling to cope emotionally.
Conclusions
Findings from this review were mixed. Evidence from cohort studies indicated a specialist clinic may be a means of predicting or preventing preterm birth. Testing this in a randomised controlled trial is desirable, though may be hard to achieve due to the growing focus of such clinics on managing women at high risk of preterm birth. Ongoing research has to recognize women’s experiences and perceptions of such a clinic. Further clarification of the optimal referral route and a clear and standardized management and cost economic evaluation plan are also required. Fathers support and experience of PTB clinics should also be included in further research
Estimating health-adjusted life expectancy conditional on risk factors: results for smoking and obesity
BACKGROUND: Smoking and obesity are risk factors causing a large burden of disease. To help formulate and prioritize among smoking and obesity prevention activities, estimations of health-adjusted life expectancy (HALE) for cohorts that differ solely in their lifestyle (e.g. smoking vs. non smoking) can provide valuable information. Furthermore, in combination with estimates of life expectancy (LE), it can be tested whether prevention of obesity and smoking results in compression of morbidity. METHODS: Using a dynamic population model that calculates the incidence of chronic disease conditional on epidemiological risk factors, we estimated LE and HALE at age 20 for a cohort of smokers with a normal weight (BMI < 25), a cohort of non-smoking obese people (BMI>30) and a cohort of 'healthy living' people (i.e. non smoking with a BMI < 25). Health state valuations for the different cohorts were calculated using the estimated disease prevalence rates in combination with data from the Dutch Burden of Disease study. Health state valuations are multiplied with life years to estimate HALE. Absolute compression of morbidity is defined as a reduction in unhealthy life expectancy (LE-HALE) and relative compression as a reduction in the proportion of life lived in good health (LE-HALE)/LE. RESULTS: Estimates of HALE are highest for a 'healthy living' cohort (54.8 years for men and 55.4 years for women at age 20). Differences in HALE compared to 'healthy living' men at age 20 are 7.8 and 4.6 for respectively smoking and obese men. Differences in HALE compared to 'healthy living' women at age 20 are 6.0 and 4.5 for respectively smoking and obese women. Unhealthy life expectancy is about equal for all cohorts, meaning that successful prevention would not result in absolute compression of morbidity. Sensitivity analyses demonstrate that although estimates of LE and HALE are sensitive to changes in disease epidemiology, differences in LE and HALE between the different cohorts are fairly robust. In most cases, elimination of smoking or obesity does not result in absolute compression of morbidity but slightly increases the part of life lived in good health. CONCLUSION: Differences in HALE between smoking, obese and 'healthy living' cohorts are substantial and similar to differences in LE. However, our results do not indicate that substantial compression of morbidity is to be expected as a result of successful smoking or obesity prevention
Decreasing incidence of peptic ulcer complications after the introduction of the proton pump inhibitors, a study of the Swedish population from 1974–2002
<p>Abstract</p> <p>Background</p> <p>Despite a decreasing incidence of peptic ulcer disease, most previous studies report a stabile incidence of ulcer complications. We wanted to investigate the incidence of peptic ulcer complications in Sweden before and after the introduction of the proton pump inhibitors (PPI) in 1988 and compare these data to the sales of non-steroid anti-inflammatory drugs (NSAID) and acetylsalicylic acid (ASA).</p> <p>Methods</p> <p>All cases of gastric and duodenal ulcer complications diagnosed in Sweden from 1974 to 2002 were identified using the National hospital discharge register. Information on sales of ASA/NSAID was obtained from the National prescription survey.</p> <p>Results</p> <p>When comparing the time-periods before and after 1988 we found a significantly lower incidence of peptic ulcer complications during the later period for both sexes (p < 0.001). Incidence rates varied from 1.5 to 7.8/100000 inhabitants/year regarding perforated peptic ulcers and from 5.2 to 40.2 regarding peptic ulcer bleeding. The number of sold daily dosages of prescribed NSAID/ASA tripled from 1975 to 2002. The number of prescribed sales to women was higher than to males. Sales of low-dose ASA also increased. The total volume of NSAID and ASA, i.e. over the counter sale and sold on prescription, increased by 28% during the same period.</p> <p>Conclusion</p> <p>When comparing the periods before and after the introduction of the proton pump inhibitors we found a significant decrease in the incidence of peptic ulcer complications in the Swedish population after 1988 when PPI were introduced on the market. The cause of this decrease is most likely multifactorial, including smoking habits, NSAID consumption, prevalence of Helicobacter pylori and the introduction of PPI. Sales of prescribed NSAID/ASA increased, especially in middle-aged and elderly women. This fact seems to have had little effect on the incidence of peptic ulcer complications.</p
Effects of selective serotonin reuptake inhibitor treatment on plasma oxytocin and cortisol in major depressive disorder
Background: Oxytocin is known for its capacity to facilitate social bonding, reduce anxiety and for its actions on the stress hypothalamopituitary adrenal (HPA) axis. Since oxytocin can physiologically suppress activity of the HPA axis, clinical applications of this neuropeptide have been proposed in conditions where the function of the HPA axis is dysregulated. One such condition is major depressive disorder (MDD). Dysregulation of the HPA system is the most prominent endocrine change seen with MDD, and normalizing the HPA axis is one of the major targets of recent treatments. The potential clinical application of oxytocin in MDD requires improved understanding of its relationship to the symptoms and underlying pathophysiology of MDD. Previous research has investigated potential correlations between oxytocin and symptoms of MDD, including a link between oxytocin and treatment related symptom reduction. The outcomes of studies investigating whether antidepressive treatment (pharmacological and non-pharmacological) influences oxytocin concentrations in MDD, have produced conflicting outcomes. These outcomes suggest the need for an investigation of the influence of a single treatment class on oxytocin concentrations, to determine whether there is a relationship between oxytocin, the HPA axis (e.g., oxytocin and cortisol) and MDD. Our objective was to measure oxytocin and cortisol in patients with MDD before and following treatment with selective serotonin reuptake inhibitors, SSRI. Method: We sampled blood from arterial plasma. Patients with MDD were studied at the same time twice; pre- and post- 12 weeks treatment, in an unblinded sequential design (clinicaltrials.govNCT00168493). Results: Results did not reveal differences in oxytocin or cortisol concentrations before relative to following SSRI treatment, and there were no significant relationships between oxytocin and cortisol, or these two physiological variables and psychological symptom scores, before or after treatment. Conclusions: These outcomes demonstrate that symptoms of MDD were reduced following effective treatment with an SSRI, and further, stress physiology was unlikely to be a key factor in this outcome. Further research is required to discriminate potential differences in underlying stress physiology for individuals with MDD who respond to antidepressant treatment, relative to those who experience treatment resistance.Charlotte Keating, Tye Dawood, David A Barton, Gavin W Lambert and Alan J Tilbroo
Observation of the Baryonic Flavor-Changing Neutral Current Decay Lambda_b -> Lambda mu+ mu-
We report the first observation of the baryonic flavor-changing neutral
current decay Lambda_b -> Lambda mu+ mu- with 24 signal events and a
statistical significance of 5.8 Gaussian standard deviations. This measurement
uses ppbar collisions data sample corresponding to 6.8fb-1 at sqrt{s}=1.96TeV
collected by the CDF II detector at the Tevatron collider. The total and
differential branching ratios for Lambda_b -> Lambda mu+ mu- are measured. We
find B(Lambda_b -> Lambda mu+ mu-) = [1.73+-0.42(stat)+-0.55(syst)] x 10^{-6}.
We also report the first measurement of the differential branching ratio of B_s
-> phi mu+ mu- using 49 signal events. In addition, we report branching ratios
for B+ -> K+ mu+ mu-, B0 -> K0 mu+ mu-, and B -> K*(892) mu+ mu- decays.Comment: 8 pages, 2 figures, 4 tables. Submitted to Phys. Rev. Let
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