969 research outputs found
Direct microwave measurement of Andreev-bound-state dynamics in a proximitized semiconducting nanowire
The modern understanding of the Josephson effect in mesosopic devices derives
from the physics of Andreev bound states, fermionic modes that are localized in
a superconducting weak link. Recently, Josephson junctions constructed using
semiconducting nanowires have led to the realization of superconducting qubits
with gate-tunable Josephson energies. We have used a microwave circuit QED
architecture to detect Andreev bound states in such a gate-tunable junction
based on an aluminum-proximitized InAs nanowire. We demonstrate coherent
manipulation of these bound states, and track the bound-state fermion parity in
real time. Individual parity-switching events due to non-equilibrium
quasiparticles are observed with a characteristic timescale . The of a topological nanowire
junction sets a lower bound on the bandwidth required for control of Majorana
bound states
Volcanic ash supply to the surface ocean â remote sensing of biological responses and their wider biogeochemical significance
Transient micronutrient enrichment of the surface ocean can enhance phytoplankton growth rates and alter microbial community structure with an ensuing spectrum of biogeochemical feedbacks. Strong phytoplankton responses to micronutrients supplied by volcanic ash have been reported recently. Here we: (i) synthesize findings from these recent studies; (ii) report the results of a new remote sensing study of ash fertilization; and (iii) calculate theoretical bounds of ash-fertilized carbon export. Our synthesis highlights that phytoplankton responses to ash do not always simply mimic that of iron amendment; the exact mechanisms for this are likely biogeochemically important but are not yet well understood. Inherent optical properties of ash-loaded seawater suggest rhyolitic ash biases routine satellite chlorophyll-a estimation upwards by more than an order of magnitude for waters with 0.5 mg chlorophyll-a m-3. For this reason post-ash-deposition chlorophyll-a changes in oligotrophic waters detected via standard Case 1 (open ocean) algorithms should be interpreted with caution. Remote sensing analysis of historic events with a bias less than a factor of 2 provided limited stand-alone evidence for ash-fertilization. Confounding factors were poor coverage, incoherent ash dispersal, and ambiguity ascribing biomass changes to ash supply over other potential drivers. Using current estimates of iron release and carbon export efficiencies, uncertainty bounds of ash-fertilized carbon export for 3 events are presented. Patagonian iron supply to the Southern Ocean from volcanic eruptions is less than that of windblown dust on thousand year timescales but can dominate supply at shorter timescales. Reducing uncertainties in remote sensing of phytoplankton response and nutrient release from ash are avenues for enabling assessment of the oceanic response to large-scale transient nutrient enrichment
Effect of prenatal screening on trends in perinatal mortality associated with congenital anomalies before and after the introduction of prenatal screening:A population-based study in the Northern Netherlands
BACKGROUND: Perinatal mortality in foetuses/children with congenital anomalies remains high. Prenatal diagnosis, essential for risk assessment and organisation of perinatal/postnatal care, offers parents the opportunity to consider the termination of pregnancy. In times of quick changes in prenatal screening programmes, it is relevant to evaluate the effect of prenatal screening on perinatal mortality rates. OBJECTIVES: The objective of this study was to study trends in early foetal and perinatal mortality associated with congenital anomalies before/after the introduction of the Dutch prenatal screening programme. METHODS: This populationâbased cohort study included 8535 foetuses/neonates with congenital anomalies born in the Northern Netherlands between 2001 and 2017. Total deaths were defined as sum of early foetal (before 24Â weeksâ gestation) and perinatal deaths (from 24Â weeksâ gestation till day 7 postâpartum). Foetal deaths were categorised into spontaneous or elective termination of pregnancy for foetal anomalies (TOPFA). Trends in total mortality as well as early foetal and perinatal mortality were studied. Joinpoint regression was used to calculate the average annual percentage chance (AAPC) and identify linear trends in mortality within subperiods. RESULTS: Total and perinatal mortality were 17% and 4%. Total mortality was higher in abnormal karyotype and central nervous system anomalies. We observed an increase in total mortality over time: 11.9% in 2001 versus 21.9% in 2017 (AAPC 2.6, 95% confidence interval [CI] 1.5, 3.7), caused by an increase in early foetal mortality from 5.5% to 19.2% (AAPC 8.7, 95% CI 4.7, 12.9) and a decrease in perinatal mortality from 6.4% to 2.7% (AAPC â5.6, 95% CI â10.0, â1.0). The increase in early foetal mortality reflects an increase in TOPFA from 3.6% to 16.9% (AAPC 8.3, 95% CI 4.2, 12.7), mostly occurring at 13â14 and 20â23Â weeksâ gestation. CONCLUSIONS: The introduction of the prenatal screening programme led to a decrease in perinatal mortality among foetuses and neonates with congenital anomalies and a marked increase in early foetal mortality before 24Â weeksâ gestation due to higher rates of TOPFA
Awareness and experiences of cosmetic treatment providers with body dysmorphic disorder in Saudi Arabia
Body Dysmorphic Disorder (BDD) is defined as a constant obsession with one's external appearance and flaws, and it falls under the criteria of neuropsychiatric disorders. Individuals suffering from this disorder may seek unnecessary cosmetic procedures from cosmetic treatment providers such as dermatologists or plastic surgeons. Cosmetic treatments have become readily available, which has led to an influx of undiagnosed BDD patients electing to undergo such treatments. Therefore, physicians should have the clinical knowledge about BDD to diagnose and manage these cases to avoid psychological and physical harm to these patients. However, there were no studies conducted in our region to assess the awareness of BDD among physicians who provide cosmetic treatments with regards to their attitude toward such cases and how they would manage it. This study aims to assess the awareness of Body Dysmorphic Disorder among Saudi physicians who provide cosmetic treatments. We conducted an observational cross-sectional study among physicians practicing in hospitals and cosmetic clinics in Riyadh and Jeddah city (Saudi Arabia), who perform cosmetic procedures, namely dermatologists, plastic surgeons, and otorhinolaryngologists. A paper-based questionnaire consisting of multiple-choice questions was distributed among them. The total number of participants was 155 physicians: 113 (72.9%) males and 42 (27.1%) females. Eighty-two (52.9%) participants reported that they have been familiar with the diagnostic criteria of BDD for a long time and ninety-nine (63.8%) reported being familiar with the clinical picture of BDD. Sixty-three (40.6%) participants estimated the prevalence of BDD cases seen in cosmetic practice to range from 1%-5%, and most agreed on an equal prevalence of BDD among female and male patients. Half of the participants (n = 76) (49%) reported that they sometimes share knowledge about BDD with patients whom they suspect to suffer from this condition. In conclusion, cosmetic treatment providers in Saudi Arabia are aware of BDD, but we have identified a discrepancy between the self-reported participant knowledge of diagnostic criteria and their ability to accurately estimate the prevalence of BDD cases seen in clinical practice
Continuous monitoring of a trapped, superconducting spin
Readout and control of fermionic spins in solid-state systems are key
primitives of quantum information processing and microscopic magnetic sensing.
The highly localized nature of most fermionic spins decouples them from
parasitic degrees of freedom, but makes long-range interoperability difficult
to achieve. In light of this challenge, an active effort is underway to
integrate fermionic spins with circuit quantum electrodynamics (cQED), which
was originally developed in the field of superconducting qubits to achieve
single-shot, quantum-non-demolition (QND) measurements and long-range
couplings. However, single-shot readout of an individual spin with cQED has
remained elusive due to the difficulty of coupling a resonator to a particle
trapped by a charge-confining potential. Here we demonstrate the first
single-shot, cQED readout of a single spin. In our novel implementation, the
spin is that of an individual superconducting quasiparticle trapped in the
Andreev levels of a semiconductor nanowire Josephson element. Due to a
spin-orbit interaction inside the nanowire, this "superconducting spin"
directly determines the flow of supercurrent through the element. We harnessed
this spin-dependent supercurrent to achieve both a zero-field spin splitting as
well as a long-range interaction between the quasiparticle and a
superconducting microwave resonator. Owing to the strength of this interaction
in our device, measuring the resultant spin-dependent resonator frequency
yielded QND spin readout with 92% fidelity in 1.9 s and allowed us to
monitor the quasiparticle's spin in real time. These results pave the way for
new "fermionic cQED" devices: superconducting spin qubits operating at zero
magnetic field, devices in which the spin has enhanced governance over the
circuit, and time-domain measurements of Majorana modes
Verbal and facial-emotional Stroop tasks reveal specific attentional interferences in sad mood
Mood congruence refers to the tendency of individuals to attend to information more readily when it has the same emotional content as their current mood state. The aim of the present study was to ascertain whether attentional interference occurred for participants in sad mood states for emotionally relevant stimuli (mood-congruence), and to determine whether this interference occurred for both valenced words and valenced faces. A mood induction procedure was administered to 116 undergraduate females divided into two equal groups for the sad and happy mood condition. This study employed three versions of the Stroop task: color, verbal-emotional, and a facial-emotional Stroop. The two mood groups did not differ on the color Stroop. Significant group differences were found on the verbal-emotional Stroop for sad words with longer latencies for sad-induced participants. Main findings for the facial-emotional Stroop were that sad mood is associated with attentional interference for angry-threatening faces as well as longer latencies for neutral faces. Group differences were not found for positive stimuli. These findings confirm that sad mood is associated with attentional interference for mood-congruent stimuli in the verbal domain (sad words), but this mood-congruent effect does not necessarily apply to the visual domain (sad faces). Attentional interference for neutral faces suggests sad mood participants did not necessarily see valence-free faces. Attentional interference for threatening stimuli is often associated with anxiety; however, the current results show that threat is not an attentional interference observed exclusively in states of anxiety but also in sad mood
The Allelic Landscape of Human Blood Cell Trait Variation and Links to Common Complex Disease.
Coherent manipulation of an Andreev spin qubit
Two promising architectures for solid-state quantum information processing
are electron spins in semiconductor quantum dots and the collective
electromagnetic modes of superconducting circuits. In some aspects, these two
platforms are dual to one another: superconducting qubits are more easily
coupled but are relatively large among quantum devices ,
while electrostatically-confined electron spins are spatially compact () but more complex to link. Here we combine beneficial aspects
of both platforms in the Andreev spin qubit: the spin degree of freedom of an
electronic quasiparticle trapped in the supercurrent-carrying Andreev levels of
a Josephson semiconductor nanowire. We demonstrate coherent spin manipulation
by combining single-shot circuit-QED readout and spin-flipping Raman
transitions, finding a spin-flip time and a spin
coherence time . These results herald a new spin qubit
with supercurrent-based circuit-QED integration and further our understanding
and control of Andreev levels -- the parent states of Majorana zero modes -- in
semiconductor-superconductor heterostructures
A global perspective on marine photosynthetic picoeukaryote community structure
A central goal in ecology is to understand the factors affecting the temporal dynamics and spatial distribution of microorganisms and the underlying processes causing differences in community structure and composition. However, little is known in this respect for photosynthetic picoeukaryotes (PPEs), algae that are now recognised as major players in marine CO2 fixation. Here, we analysed dot blot hybridisation and cloningâsequencing data, using the plastid-encoded 16S rRNA gene, from seven research cruises that encompassed all four ocean biomes. We provide insights into global abundance, α- and ÎČ-diversity distribution and the environmental factors shaping PPE community structure and composition. At the class level, the most commonly encountered PPEs were Prymnesiophyceae and Chrysophyceae. These taxa displayed complementary distribution patterns, with peak abundances of Prymnesiophyceae and Chrysophyceae in waters of high (25:1) or low (12:1) nitrogen:phosphorus (N:P) ratio, respectively. Significant differences in phylogenetic composition of PPEs were demonstrated for higher taxonomic levels between ocean basins, using Unifrac analyses of clone library sequence data. Differences in composition were generally greater between basins (interbasins) than within a basin (intrabasin). These differences were primarily linked to taxonomic variation in the composition of Prymnesiophyceae and Prasinophyceae whereas Chrysophyceae were phylogenetically similar in all libraries. These data provide better knowledge of PPE community structure across the world ocean and are crucial in assessing their evolution and contribution to CO2 fixation, especially in the context of global climate change
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