500 research outputs found
Emulated nuclear spin gyroscope with NV centers in diamond
Nuclear spins in solid-state platforms are promising for building rotation
sensors due to their long coherence times. Among these platforms,
nitrogen-vacancy centers have attracted considerable attention with ambient
operating conditions. However, the current performance of NV gyroscopes remains
limited by the degraded coherence when operating with large spin ensembles.
Protecting the coherence of these systems requires a systematic study of the
coherence decay mechanism. Here we present the use of nitrogen-15 nuclear spins
of NV centers in building gyroscopes, benefiting from its simpler energy
structure and vanishing nuclear quadrupole term compared with nitrogen-14
nuclear spins, though suffering from different challenges in coherence
protection. We systematically reveal the coherence decay mechanism of the
nuclear spin in different NV electronic spin manifolds and further develop a
robust coherence protection protocol based on controlling the NV electronic
spin only, achieving a 15-fold dephasing time improvement. With the developed
coherence protection, we demonstrate an emulated gyroscope by measuring a
designed rotation rate pattern, showing an order-of-magnitude sensitivity
improvement
Cerebrospinal fluid neopterin: an informative biomarker of central nervous system immune activation in HIV-1 infection
HIV-1 invades the central nervous system (CNS) in the context of acute infection, persists thereafter in the absence of treatment, and leads to chronic intrathecal immunoactivation that can be measured by the macrophage activation marker, neopterin, in cerebrospinal fluid (CSF). In this review we describe our experience with CSF neopterin measurements in 382 untreated HIV-infected patients across the spectrum of immunosuppression and HIV-related neurological diseases, in 73 untreated AIDS patients with opportunistic CNS infections, and in 233 treated patients
Assembly of functional diversity in an oceanic island flora
Oceanic island floras are well known for their morphological peculiarities and exhibit striking examples of trait evolution1–3. These morphological shifts are commonly attributed to insularity and are thought to be shaped by the biogeographical processes and evolutionary histories of oceanic islands2,4. However, the mechanisms through which biogeography and evolution have shaped the distribution and diversity of plant functional traits remain unclear5. Here we describe the functional trait space of the native flora of an oceanic island (Tenerife, Canary Islands, Spain) using extensive field and laboratory measurements, and relate it to global trade-offs in ecological strategies. We find that the island trait space exhibits a remarkable functional richness but that most plants are concentrated around a functional hotspot dominated by shrubs with a conservative life-history strategy. By dividing the island flora into species groups associated with distinct biogeographical distributions and diversification histories, our results also suggest that colonization via long-distance dispersal and the interplay between inter-island dispersal and archipelago-level speciation processes drive functional divergence and trait space expansion. Contrary to our expectations, speciation via cladogenesis has led to functional convergence, and therefore only contributes marginally to functional diversity by densely packing trait space around shrubs. By combining biogeography, ecology and evolution, our approach opens new avenues for trait-based insights into how dispersal, speciation and persistence shape the assembly of entire native island floras.Fil: Barajas Barbosa, Martha Paola. Martin-luther-Universität Halle-Wittenberg; Alemania. German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; Alemania. Universität Göttingen; AlemaniaFil: Craven, Dylan. Data Observatory Foundation; Chile. Universidad Mayor; ChileFil: Weigelt, Patrick. Universität Göttingen; AlemaniaFil: Denelle, Pierre. Universität Göttingen; AlemaniaFil: Otto, RĂĽdiger. Universidad de La Laguna; EspañaFil: DĂaz, Sandra Myrna. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂa Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂsicas y Naturales. Instituto Multidisciplinario de BiologĂa Vegetal; ArgentinaFil: Price, Jonathan. University Of Hawaii At Hilo; Estados UnidosFil: Fernández Palacios, JosĂ© MarĂa. Universidad de La Laguna; EspañaFil: Kreft, Holger. Universität Göttingen; Alemani
Unmet clinical needs for COVID-19 tests in UK health and social care settings
There is an urgent requirement to identify which clinical settings are in most need of COVID-19 tests and the priority role(s) for tests in these settings to accelerate the development of tests fit for purpose in health and social care across the UK. This study sought to identify and prioritize unmet clinical needs for COVID-19 tests across different settings within the UK health and social care sector via an online survey of health and social care professionals and policymakers. Four hundred and forty-seven responses were received between 22nd May and 15th June 2020. Hospitals and care homes were recognized as the settings with the greatest unmet clinical need for COVID-19 diagnostics, despite reporting more access to laboratory molecular testing than other settings. Hospital staff identified a need for diagnostic tests for symptomatic workers and patients. In contrast, care home staff expressed an urgency for screening at the front door to protect high-risk residents and limit transmission. The length of time to test result was considered a widespread problem with current testing across all settings. Rapid tests for staff were regarded as an area of need across general practice and dental settings alongside tests to limit antibiotics use
We are 60!
Here we are midway in our 60th Anniversary year. Since I last wrote, quite a few things have happened with the journal and AIP Publishing. First, of course, AIP Publishing have signed up to the Declaration on Research Assessment (DORA), aligning well with the mantra which has always been a core principle in Applied Physics Letters (APL)—the quality and clarity of the manuscript, the contribution it makes to the field, and the potential it offers for new applied physics opportunities are key for us—not the immediacy of its impact or trend following. Having said all that, I am proud that the impact factor of the journal continues to increase and that communities of applied physics researchers are discovering or returning to the journal
GRB010222: afterglow emission from a rapidly decelerating shock
The GRB010222 optical and near-infrared (NIR) afterglow was monitored at the
TNG and other Italian telescopes starting ~1 day after the high-energy prompt
event. The optical BVR light curves, which are the best sampled, are
continuously steepening, and can be described by two power laws, f(t) =
t^(-alpha), of indices alpha_1 ~ 0.7 and alpha_2 ~ 1.3 before and after a break
occurring at about 0.5 days after the GRB start time, respectively. This model
accounts well also for the flux in the U, I and J bands, which are less well
monitored. The temporal break appears to be achromatic. The two K-band points
are not consistent with the above behaviour, and rather suggest a constant
trend. A low-resolution optical spectrum has also been taken with TNG. In the
optical spectrum we found three absorption systems at different redshifts
(0.927, 1.155 and 1.475), the highest of which represents a lower limit to, and
probably coincides with, the redshift of this GRB. The broad-band optical
spectral energy distributions do not appear to vary with time, consistently
with the achromatic behaviour of the light curves. We compare our measurements
with different afterglow evolution scenarios and we find that they favor a
transition from relativistic to non-relativistic conditions in the shock
propagation.Comment: Accepted by Astronomy and Astrophysics; modified according to
referee's comments. Two figures added, U-band photometry corrected,
hydrodynamic description of the afterglow revised, host galaxy absorption
considered, references adde
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See & Eat! Using E-books to Promote Vegetable Eating Among Preschoolers: Findings From an Italian Sample
Different strategies have been developed to help parents with introducing new or disliked vegetables. Nonetheless, many parents of preschoolers struggle against children's refusal to eat vegetables. In this study, we aimed to evaluate the effectiveness of e-books in promoting positive attitudes toward vegetables through repeated visual exposures. A total of 61 families with preschoolers joined the See & Eat study and received an e-book about one of two vegetables chosen from a list of 24. Parents provided ratings of children's willingness to taste, intake, and liking of the chosen vegetables before and after reading the e-book; parents also evaluated their children's food fussiness and their agreement with respect to three mealtime goals of the family. Using a 2 (vegetable: target or non-target) Ă— 2 (time: pre-test or post-test) within-subjects analysis, results from 53 families revealed a significant increase in children's willingness to taste, intake, and liking at post-test of both target and non-target vegetables. Following a two-week parent-child e-book reading intervention, children's food fussiness and parents' endorsement of positive mealtime goals slightly but significantly increased. Results suggest that e-books are effective in encouraging healthy eating among preschoolers and that the positive effect of e-book reading can generalize to other vegetables
Cerebrospinal Fluid Viral Load Across the Spectrum of Untreated Human Immunodeficiency Virus Type 1 (HIV-1) Infection: A Cross-Sectional Multicenter Study
Background The aim of this large multicenter study was to determine variations in cerebrospinal fluid (CSF) HIV-RNA in different phases of untreated human immunodeficiency virus type 1 (HIV-1) infection and its associations with plasma HIV-RNA and other biomarkers. Methods Treatment naive adults with available CSF HIV-RNA quantification were included and divided into groups representing significant disease phases. Plasma HIV-RNA, CSF white blood cell count (WBC), neopterin, and albumin ratio were included when available. Results In total, 1018 patients were included. CSF HIV-RNA was in median (interquartile range [IQR]) 1.03 log(10) (0.37-1.86) copies/mL lower than in plasma, and correlated with plasma HIV-RNA (r = 0.44, P < .01), neopterin concentration in CSF (r = 0.49, P < .01) and in serum (r = 0.29, P < .01), CSF WBC (r = 0.34, P < .01) and albumin ratio (r = 0.25, P < .01). CSF HIV-RNA paralleled plasma HIV-RNA in all groups except neuroasymptomatic patients with advanced immunodeficiency (CD4 < 200) and patients with HIV-associated dementia (HAD) or opportunistic central nervous system (CNS) infections. Patients with HAD had the highest CSF HIV-RNA (in median [IQR] 4.73 (3.84-5.35) log(10) copies/mL). CSF > plasma discordance was found in 126 of 972 individuals (13%) and varied between groups, from 1% in primary HIV, 11% in neuroasymptomatic groups, up to 30% of patients with HAD. Conclusions Our study confirms previous smaller observations of variations in CSF HIV-RNA in different stages of HIV disease. Overall, CSF HIV-RNA was approximately 1 log(10) copies/mL lower in CSF than in plasma, but CSF discordance was found in a substantial minority of subjects, most commonly in patients with HAD, indicating increasing CNS compartmentalization paralleling disease progression. HIV-RNA is detectable in cerebrospinal fluid (CSF) across all stages of untreated HIV and usually parallel plasma HIV-RNA at a lower level. A substantial proportion (13%) of patients have CSF>plasma HIV-RNA, most commonly in patients with HIV-associated dementia
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