Polariton propagation in weak confinement quantum wells

Exciton-polariton propagation in a quantum well, under centre-of-mass quantization, is computed by a variational self-consistent microscopic theory. The Wannier exciton envelope functions basis set is given by the simple analytical model of ref. [1], based on pure states of the centre-of-mass wave vector, free from fitting parameters and "ad hoc" (the so called additional boundary conditions-ABCs) assumptions. In the present paper, the former analytical model is implemented in order to reproduce the centre-of-mass quantization in a large range of quantum well thicknesses (5a_B < L < inf.). The role of the dynamical transition layer at the well/barrier interfaces is discussed at variance of the classical Pekar's dead-layer and ABCs. The Wannier exciton eigenstates are computed, and compared with various theoretical models with different degrees of accuracy. Exciton-polariton transmission spectra in large quantum wells (L>> a_B) are computed and compared with experimental results of Schneider et al.\cite{Schneider} in high quality GaAs samples. The sound agreement between theory and experiment allows to unambiguously assign the exciton-polariton dips of the transmission spectrum to the pure states of the Wannier exciton center-of-mass quantization.Comment: 15 pages, 15 figures; will appear in Phys.Rev.

Chemostratigraphy of Neoproterozoic carbonates: implications for 'blind dating'

The delta C-13(carb) and Sr-87/Sr-86 secular variations in Neoproteozoic seawater have been used for the purpose of 'isotope stratigraphy' but there are a number of problems that can preclude its routine use. In particular, it cannot be used with confidence for 'blind dating'. The compilation of isotopic data on carbonate rocks reveals a high level of inconsistency between various carbon isotope age curves constructed for Neoproteozoic seawater, caused by a relatively high frequency of both global and local delta C-13(carb) fluctuations combined with few reliable age determinations. Further complication is caused by the unresolved problem as to whether two or four glaciations, and associated negative delta C-13(carb) excursions, can be reliably documented. Carbon isotope stratigraphy cannot be used alone for geological correlation and 'blind dating'. Strontium isotope stratigraphy is a more reliable and precise tool for stratigraphic correlations and indirect age determinations. Combining strontium and carbon isotope stratigraphy, several discrete ages within the 590-544 Myr interval, and two age-groups at 660-610 and 740-690 Myr can be resolved

Amyotrophic lateral sclerosis: one or multiple causes?

The Amyotrophic lateral sclerosis (ALS) is the most common form of motor neuron disease in the adulthood, and it is characterized by rapid and progressive compromise of the upper and lower motor neurons. The majority of the cases of ALS are classified as sporadic and, until now, a specific cause for these cases still is unknown. To present the different hypotheses on the etiology of ALS. It was carried out a search in the databases: Bireme, Scielo and Pubmed, in the period of 1987 to 2011, using the following keywords: Amyotrophic lateral sclerosis, motor neuron disease, etiology, causes and epidemiology and its similar in Portuguese and Spanish. It did not have consensus as regards the etiology of ALS. Researches demonstrates evidences as regards intoxication by heavy metals, environmental and occupational causes, genetic mutations (superoxide dismutase 1), certain viral infections and the accomplishment of vigorous physical activity for the development of the disease. There is still no consensus regarding the involved factors in the etiology of ALS. In this way, new research about these etiologies are necessary, for a better approach of the patients, promoting preventive programs for the disease and improving the quality of life of the patients

Evaluating 'living well' with mild-to-moderate dementia: Co-production and validation of the IDEAL My Life Questionnaire

YesWe aimed to co-produce and validate an accessible, evidence-based questionnaire measuring 'living well' with dementia that reflects the experience of people with mild-to-moderate dementia. Nine people with dementia formed a co-production group. An initial series of workshops generated the format of the questionnaire and a longlist of items. Preliminary testing with 53 IDEAL cohort participants yielded a shortlist of items. These were tested with 136 IDEAL cohort participants during a further round of data collection and assessed for reliability and validity. The co-production group contributed to decisions throughout and agreed the final version. An initial list of 230 items was reduced to 41 for initial testing, 12 for full testing, and 10 for the final version. The 10-item version had good internal consistency and test-retest reliability, and a single factor structure. Analyses showed significant large positive correlations with scores on measures of quality of life, well-being, and satisfaction with life, and expected patterns of association including a significant large negative association with depression scores and no association with cognitive test scores. The co-produced My Life Questionnaire is an accessible and valid measure of 'living well' with dementia suitable for use in a range of contexts.This work was supported by the Economic and Social Research Council, National Institute for Health and Care Research (ES/L001853/2), and Alzheimer’s Society (348, AS-PR2-16-001)

Anti-SARS-CoV-2 inactivated vaccine in patients with ANCA-associated vasculitis: Immunogenicity, safety, antibody decay and the booster dose

Objective: To evaluate inactivated CoronaVac prime vaccination, antibody decay, booster dose, and safety in ANCA-Associated Vasculitis (AAV) patients. Methods: Fifty-three AAV patients and 106 Controls (CG) received CoronaVac on days: D0 (first dose), D28(second dose), and D210 (booster dose, 32 AAV: 32 CG). The primary outcome was immunogenicity after the second vaccine dose (day 69) assessed by Seroconversion Rates (SC) of anti-SARS-CoV-2 S1/S2 IgG and Neutralizing Antibodies (NAb). Secondary outcomes were safety, immunogenicity (D28/D240), 6-months antibody decay (D210) and the booster dose response (D240). Results: At D69 SC (65.1% vs. 96.8%, p&nbsp;=&nbsp;0.0001), GMT (21.3&nbsp;UA/mL vs. 67.7&nbsp;UA/mL, p&nbsp;&lt;&nbsp;0.001) and NAb- positivity (53.7% vs. 80.6%, p&nbsp;=&nbsp;0.001) were moderate but lower in naïve-AAV patients than CG. Patients without SC used more often IS (93.3% vs. 53.3%, p&nbsp;=&nbsp;0.015), mycophenolate mofetil (20% vs. 0%, p&nbsp;=&nbsp;0.037) and prednisone (60.0% vs. 28.6%, p&nbsp;=&nbsp;0.057) than seroconverted. NAb negativity in AAV patients was associated with prednisone treatment (57.9% vs. 18.2%, p&nbsp;=&nbsp;0.015) and IS (84.2% vs. 55.0%, p&nbsp;=&nbsp;0.046). Logistic regression analysis models showed that only prednisone was associated with lower seroconversion (OR&nbsp;=&nbsp;0.2, 0,95% CI 0.05‒0.86, p&nbsp;=&nbsp;0.030) and with lower NAb positivity (OR&nbsp;=&nbsp;0.2, 0,95% CI 0.05‒0.88, p&nbsp;=&nbsp;0.034). After six months (D69‒D210) a decrease in IgG positivity occurred in 32 AAV patients (15.7%, p&nbsp;=&nbsp;0.074) and 32 CG (18.7%, p&nbsp;=&nbsp;0.041). For the NAb positivity, the 6-month decrease was not significant (p&nbsp;=&nbsp;0.114) whereas a major reduction occurred for CG (p&nbsp;&lt;&nbsp;0.001). A booster dose (D240) resulted in an increment in IgG-positivity (21.9%, p&nbsp;=&nbsp;0.023) and NAb-positivity (34.4%, p&nbsp;=&nbsp;0.006) in AAV patients. No moderate/severe adverse events attributable to the vaccine were observed. Conclusion: This study provides novel data on the excellent safety and moderate immunogenicity of CoronaVac in AAV patients. A six-month mild antibody waning was observed with a good response to the booster dose, although levels remained lower than CG (CoronavRheum-NCT04754698)

Neuroplasticity in visual impairments

The visual acuity loss enables the brain to access new pathways in the quest to overcome the visual limitation and this is wellknown as neuroplasticity which have mechanisms to cortical reorganization. In this review, we related the evidences about the neuroplasticity as well as cortical anatomical differences and functional repercussions in visual impairments. We performed a systematic review of PUBMED database, without date or status publication restrictions. The findings demonstrate that the visual impairment produce a compensatory sensorial effect, in which non-visual areas are related to both cross (visual congenital) and multimodal (late blind) neuroplasticity

Predictors of awareness of functional ability in people with dementia: the contribution of personality, cognition, and neuropsychiatric symptoms. Findings from the IDEAL programme

YesIntroduction: Discrepancy scores reflecting the difference between parallel ratings made by people living with dementia (PwD) in the mild-to-moderate stages and by their informants provide a way to investigate awareness of functional ability in relation to activities of daily living (ADL). Methods: Two measures of ADL (Functional Activities Questionnaire; Dependence Scale) were completed by 1,227 PwD and their informants in the IDEAL cohort study baseline assessment. Self-rated and informant-rated scores were used to calculate discrepancies, which were used as an indicator of awareness of functional ability. Smaller discrepancy scores were considered to reflect greater awareness on the part of PwD. PwD completed questionnaires on depression, personality, comorbidities, neuropsychiatric symptoms, and completed a measure of cognition. Informants provided ratings of stress. Univariable and multiple regressions were used to investigate factors related to ADL discrepancy. Results: A similar pattern of associations were found for both ADL discrepancy scores. Smaller discrepancy scores were associated with higher levels of depression, higher neuroticism, fewer neuropsychiatric symptoms, higher comorbidity, lower carer stress, and receipt of less than 1 hour of care per day from the informant. Discussion/Conclusion: There was a clear pattern of factors that were associated with greater awareness for both measures of functional ability. These factors associated with smaller discrepancy scores could be used to identify PwD who might benefit from targeted interventions to support their independence.Economic and Social Research Council (ESRC) and the National Institute for Health and Care Research (NIHR) grant ES/L001853/2; Alzheimer’s Society as a Centre of Excellence, grant number 348, AS-PR2-16-00

Health conditions in spousal caregivers of people with dementia and their relationships with stress, caregiving experiences, and social networks: longitudinal findings from the IDEAL programme

YesObjectives: Longitudinal evidence documenting health conditions in spousal caregivers of people with dementia and whether these influence caregivers’ outcomes is scarce. This study explores type and number of health conditions over two years in caregivers of people with dementia and subgroups based on age, sex, education, hours of care, informant-rated functional ability, neuropsychiatric symptoms, cognition of the person with dementia, and length of diagnosis in the person with dementia. It also explores whether over time the number of health conditions is associated with caregivers’ stress, positive experiences of caregiving, and social networks Methods: Longitudinal data from the IDEAL (Improving the experience of Dementia and Enhancing Active Life) cohort were used. Participants comprised spousal caregivers (n = 977) of people with dementia. Self-reported health conditions using the Charlson Comorbidity Index, stress, positive experiences of caregiving, and social network were assessed over two years. Mixed effect models were used Results: On average participants had 1.5 health conditions at baseline; increasing to 2.1 conditions over two years. More health conditions were reported by caregivers who were older, had no formal education, provided 10 + hours of care per day, and/or cared for a person with more neuropsychiatric symptoms at baseline. More baseline health conditions were associated with greater stress at baseline but not with stress over time. Over two years, when caregivers’ health conditions increased, their stress increased whereas their social network diminished Discussion: Findings highlight that most caregivers have their own health problems which require management to avoid increased stress and shrinking of social networksEconomic and Social Research Council (ESRC) and the National Institute for Health and Care Research (NIHR) - grant ES/L001853/2. Alzheimer’s Society, grant number 348, AS-PR2-16-001. Sabatini was supported by an ESRC Postdoctoral fellowship (ES/X007766/1)

Allgrove syndrome and motor neuron disease

Allgrove or triple A syndrome (AS or AAA) is a rare autosomal recessive syndrome with variable phenotype due to mutations in AAAS gene which encodes a protein called ALADIN. Generally, it’s characterized by of adrenal insufficiency in consequence of adrenocorticotropic hormone (ACTH) resistance, besides of achalasia, and alacrimia. Neurologic features are varied and have been the subject of several case reports and reviews. A few cases of Allgrove syndrome with motor neuron disease have been already described. A 25-year-old white man, at the age of four, presented slowly progressive distal amyotrophy and weakness, autonomic dysfunction, dysphagia and lack of tears. He suffered later of orthostatic hypotension and erectile dysfunction. He presented distal amytrophy in four limbs, tongue myofasiculations, alacrimia, hoarseness and dysphagia due to achalasia. The ENMG showed generalized denervation with normal conduction velocities. Genetic testing revealed 2 known pathogenic variants in the AAAS gene (c.938T>C and c.1144_1147delTCTG). Our case presented a distal spinal amyotrophy with slow evolution and symptoms and signs of AS with a mutation in AAAS gen. Some cases of motor neuron disease, as ours, may be due to AAS. Early diagnosis is extremely important for symptomatic treatment

Longitudinal trajectories of quality of life among people with mild-to-moderate dementia: a latent growth model approach with IDEAL cohort study data

Copyright © The Author(s) 2022. Objectives We aimed to examine change over time in self-rated quality of life (QoL) in people with mild-to-moderate dementia and identify sub-groups with distinct QoL trajectories. Method We used data from people with mild-to-moderate dementia followed up at 12 and 24 months in the IDEAL cohort study (baseline n=1537). A latent growth model approach examined mean change over time in QoL, assessed with the QoL-AD scale, and investigated associations of baseline demographic, cognitive and psychological covariates with the intercept and slope of QoL. We employed growth mixture modelling to identify multiple growth trajectories. Results Overall mean QoL scores were stable and no associations with change over time were observed. Four classes of QoL trajectories were identified: two with higher baseline QoL scores, labelled Stable (74.9%) and Declining (7.6%), and two with lower baseline QoL scores, labelled Stable Lower (13.7%) and Improving (3.8%). The Declining class had higher baseline levels of depression and loneliness, and lower levels of self-esteem and optimism, than the Stable class. The Stable Lower class was characterised by disadvantage related to social structure, poor physical health, functional disability, and low psychological well-being. The Improving class was similar to the Stable Lower class but had lower cognitive test scores. Discussion Understanding individual trajectories can contribute to personalised care planning. Efforts to prevent decline in perceived QoL should primarily target psychological well-being. Efforts to improve QoL for those with poorer QoL should additionally address functional impairment, isolation, and disadvantage related to social structure.NIHR Dementias and Neurodegeneration Specialty (DeNDRoN) in England; Scottish Dementia Clinical Research Network (SDCRN); Health and Care Research Wales.; NIHR Applied Research Collaboration South-West Peninsula