No evidence for retinal damage evolving from reduced retinal blood flow in carotid artery disease

Introduction. Carotid artery disease (CAD) comprising high-grade internal carotid artery stenosis (CAS) or carotid artery occlusion (CAO) may lead to ipsilateral impaired cerebral blood flow and reduced retinal blood supply. Objective. To examine the influence of chronic CAD on retinal blood flow, retinal morphology, and visual function. Methods. Patients with unilateral CAS ≥ 50% (ECST criteria) or CAO were grouped according to the grade of the stenosis and to the flow direction of the ophthalmic artery (OA). Retinal perfusion was measured by transorbital duplex ultrasound, assessing central retinal artery (CRA) blood flow velocities. In addition, optic nerve and optic nerve sheath diameter were measured. Optical coherence tomography (OCT) was performed to study retinal morphology. Visual function was assessed using high- and low-contrast visual paradigms. Results. Twenty-seven patients were enrolled. Eyes with CAS ≥ 80%/CAO and retrograde OA blood flow showed a significant reduction in CRA peak systolic velocity (no-CAD side: 0.130 ± 0.035 m/s, CAS/CAO side: 0.098 ± 0.028; p = 0.005; n = 12). OCT, optic nerve thicknesses, and visual functional parameters did not show a significant difference. Conclusion. Despite assessable hemodynamic effects, chronic high-grade CAD does not lead to gaugeable morphological or functional changes of the retina

X-Ray-Diffraction Study of Charge-Density-Waves and Oxygen-Ordering in YBa2Cu3O6+x Superconductor

We report a temperature-dependent increase below 300 K of diffuse superlattice peaks corresponding to q_0 =(~2/5,0,0) in an under-doped YBa_2Cu_3O_6+x superconductor (x~0.63). These peaks reveal strong c-axis correlations involving the CuO_2 bilayers, show a non-uniform increase below \~220 K with a plateau for ~100-160 K, and appear to saturate in the superconducting phase. We interpret this unconventional T-dependence of the ``oxygen-ordering'' peaks as a manifestation of a charge density wave in the CuO_2 planes coupled to the oxygen-vacancy ordering.Comment: 4 pages, 4 figure

EUBerry – verhoging van duurzaamheid en consumptie kleinfruit : samenvatting activiteiten DLO Wageningen UR : PT Eindrapport EUBerry 2011-2014

Doel van dit EU-project is de bevordering van de consumptie van kwalitatief hoogwaardig vers kleinfruit door geïntegreerde gewasbescherming en residuarme teelt, verbeterde teelttechnieken en aandacht voor gezondheidsaspecten

Convection in colloidal suspensions with particle-concentration-dependent viscosity

The onset of thermal convection in a horizontal layer of a colloidal suspension is investigated in terms of a continuum model for binary-fluid mixtures where the viscosity depends on the local concentration of colloidal particles. With an increasing difference between the viscosity at the warmer and the colder boundary the threshold of convection is reduced in the range of positive values of the separation ratio psi with the onset of stationary convection as well as in the range of negative values of psi with an oscillatory Hopf bifurcation. Additionally the convection rolls are shifted downwards with respect to the center of the horizontal layer for stationary convection (psi>0) and upwards for the Hopf bifurcation (psi<0).Comment: 8 pages, 6 figures, submitted to European Physical Journal

Symptom-based staging for logopenic variant primary progressive aphasia

Background and purpose Logopenic variant primary progressive aphasia (lvPPA) is a major variant presentation of Alzheimer's disease (AD) that signals the importance of communication dysfunction across AD phenotypes. A clinical staging system is lacking for the evolution of AD-associated communication difficulties that could guide diagnosis and care planning. Our aim was to create a symptom-based staging scheme for lvPPA, identifying functional milestones relevant to the broader AD spectrum. Methods An international lvPPA caregiver cohort was surveyed on symptom development under an ‘exploratory’ survey (34 UK caregivers). Feedback from this survey informed the development of a ‘consolidation’ survey (27 UK, 10 Australian caregivers) in which caregivers were presented with six provisional clinical stages and feedback was analysed using a mixed-methods approach. Results Six clinical stages were endorsed. Early symptoms included word-finding difficulty, with loss of message comprehension and speech intelligibility signalling later-stage progression. Additionally, problems with hearing in noise, memory and route-finding were prominent early non-verbal symptoms. ‘Milestone’ symptoms were identified that anticipate daily-life functional transitions and care needs. Conclusions This work introduces a new symptom-based staging scheme for lvPPA, and highlights milestone symptoms that could inform future clinical scales for anticipating and managing communication dysfunction across the AD spectrum

Electron Dynamics in Nd1.85_{1.85}Ce.15_{.15}CuO4+δ_{4+\delta}: Evidence for the Pseudogap State and Unconventional c-axis Response

Infrared reflectance measurements were made with light polarized along the a- and c-axis of both superconducting and antiferromagnetic phases of electron doped Nd$_{1.85}$Ce$_{.15}$CuO$_{4+\delta}$. The results are compared to characteristic features of the electromagnetic response in hole doped cuprates. Within the CuO$_2$ planes the frequency dependent scattering rate, 1/$\tau(\omega)$, is depressed below $\sim$ 650 cm$^{-1}$; this behavior is a hallmark of the pseudogap state. While in several hole doped compounds the energy scales associated with the pseudogap and superconducting states are quite close, we are able to show that in Nd$_{1.85}$Ce$_{.15}$CuO$_{4+\delta}$ the two scales differ by more than one order of magnitude. Another feature of the in-plane charge response is a peak in the real part of the conductivity, $\sigma_1(\omega)$, at 50-110 cm$^{-1}$ which is in sharp contrast with the Drude-like response where $\sigma_1(\omega)$ is centered at $\omega=0$. This latter effect is similar to what is found in disordered hole doped cuprates and is discussed in the context of carrier localization. Examination of the c-axis conductivity gives evidence for an anomalously broad frequency range from which the interlayer superfluid is accumulated. Compelling evidence for the pseudogap state as well as other characteristics of the charge dynamics in Nd$_{1.85}$Ce$_{.15}$CuO$_{4+\delta}$ signal global similarities of the cuprate phase diagram with respect to electron and hole doping.Comment: Submitted to PR

The development of videoconference-based support for people living with rare dementias and their carers: Protocol for a 3-phase support group evaluation

Background: People living with rarer dementias face considerable difficulty accessing tailored information, advice, and peer and professional support. Web-based meeting platforms offer a critical opportunity to connect with others through shared lived experiences, even if they are geographically dispersed, particularly during the COVID-19 pandemic. Objective: We aim to develop facilitated videoconferencing support groups (VSGs) tailored to people living with or caring for someone with familial or sporadic frontotemporal dementia or young-onset Alzheimer disease, primary progressive aphasia, posterior cortical atrophy, or Lewy body dementia. This paper describes the development, coproduction, field testing, and evaluation plan for these groups. Methods: We describe a 3-phase approach to development. First, information and knowledge were gathered as part of a coproduction process with members of the Rare Dementia Support service. This information, together with literature searches and consultation with experts by experience, clinicians, and academics, shaped the design of the VSGs and session themes. Second, field testing involved 154 Rare Dementia Support members (people living with dementia and carers) participating in 2 rounds of facilitated sessions across 7 themes (health and social care professionals, advance care planning, independence and identity, grief and loss, empowering your identity, couples, and hope and dementia). Third, a detailed evaluation plan for future rounds of VSGs was developed. Results: The development of the small groups program yielded content and structure for 9 themed VSGs (the 7 piloted themes plus a later stages program and creativity club for implementation in rounds 3 and beyond) to be delivered over 4 to 8 sessions. The evaluation plan incorporated a range of quantitative (attendance, demographics, and geography; pre-post well-being ratings and surveys; psycholinguistic analysis of conversation; facial emotion recognition; facilitator ratings; and economic analysis of program delivery) and qualitative (content and thematic analysis) approaches. Pilot data from round 2 groups on the pre-post 3-word surveys indicated an increase in the emotional valence of words selected after the sessions. Conclusions: The involvement of people with lived experience of a rare dementia was critical to the design, development, and delivery of the small virtual support group program, and evaluation of this program will yield convergent data about the impact of tailored support delivered to geographically dispersed communities. This is the first study to design and plan an evaluation of VSGs specifically for people affected by rare dementias, including both people living with a rare dementia and their carers, and the outcome of the evaluation will be hugely beneficial in shaping specific and targeted support, which is often lacking in this population

Search for the Flavor-Changing Neutral Current Decay D0→μ+μ−D^0 \to \mu^+\mu^- with the HERA-B Detector

We report on a search for the flavor-changing neutral current decay $D^0 \to \mu^+\mu^-$ using $50 \times 10^6$ events recorded with a dimuon trigger in interactions of 920 GeV protons with nuclei by the HERA-B experiment. We find no evidence for such decays and set a 90% confidence level upper limit on the branching fraction $Br(D^0 \to \mu^+\mu^-) <2.0 \times 10^{-6}$.Comment: 17 pages, 4 figures (of which 1 double), paper to be submitted to Physics Letters