28 research outputs found
Characterization of a photon-number resolving SNSPD using Poissonian and sub-Poissonian light
Photon-number resolving (PNR) single-photon detectors are of interest for a
wide range of applications in the emerging field of photon based quantum
technologies. Especially photonic integrated circuits will pave the way for a
high complexity and ease of use of quantum photonics. Superconducting nanowire
single-photon detectors (SNSPDs) are of special interest since they combine a
high detection efficiency and a high timing accuracy with a high count rate and
they can be configured as PNR-SNSPDs. Here, we present a PNR-SNSPD with a four
photon resolution suitable for waveguide integration operating at a temperature
of 4 K. A high statistical accuracy for the photon number is achieved for a
Poissonian light source at a photon flux below 5 photons/pulse with a detection
efficiency of 22.7 +- 3.0% at 900 nm and a pulse rate frequency of 76 MHz. We
demonstrate the ability of such a detector to discriminate a sub-Poissonian
from a Poissonian light source
A type theory for strictly unital infinity ∞-categories
We use type-theoretic techniques to present an algebraic theory of ∞-categories with strict units. Starting with a known type-theoretic presentation of fully weak ∞-categories, in which terms denote valid operations, we extend the theory with a non-trivial definitional equality. This forces some operations to coincide strictly in any model, yielding the strict unit behaviour. We make a detailed investigation of the meta-theoretic properties of this theory. We give a reduction relation that generates definitional equality, and prove that it is confluent and terminating, thus yielding the first decision procedure for equality in a strictly-unital setting. Moreover, we show that our definitional equality relation identifies all terms in a disc context, providing a point comparison with a previously proposed definition of strictly unital ∞-category. We also prove a conservativity result, showing that every operation of the strictly unital theory indeed arises from a valid operation in the fully weak theory. From this, we infer that strict unitality is a property of an ∞-category rather than additional structure
A Type Theory for Strictly Unital -Categories
We present a type theory for strictly unital -categories, in which a
term computes to its strictly unital normal form. Using this as a toy model, we
argue that it illustrates important unresolved questions in the foundations of
type theory, which we explore. Furthermore, our type theory leads to a new
definition of strictly unital -category, which we claim is stronger
than any previously described in the literature.Comment: 45 page
Bodyweight Perceptions among Texas Women: The Effects of Religion, Race/Ethnicity, and Citizenship Status
Despite previous work exploring linkages between religious participation and health, little research has looked at the role of religion in affecting bodyweight perceptions. Using the theoretical model developed by Levin et al. (Sociol Q 36(1):157–173, 1995) on the multidimensionality of religious participation, we develop several hypotheses and test them by using data from the 2004 Survey of Texas Adults. We estimate multinomial logistic regression models to determine the relative risk of women perceiving themselves as overweight. Results indicate that religious attendance lowers risk of women perceiving themselves as very overweight. Citizenship status was an important factor for Latinas, with noncitizens being less likely to see themselves as overweight. We also test interaction effects between religion and race. Religious attendance and prayer have a moderating effect among Latina non-citizens so that among these women, attendance and prayer intensify perceptions of feeling less overweight when compared to their white counterparts. Among African American women, the effect of increased church attendance leads to perceptions of being overweight. Prayer is also a correlate of overweight perceptions but only among African American women. We close with a discussion that highlights key implications from our findings, note study limitations, and several promising avenues for future research
First postnatal lactate blood levels on day 1 and outcome of preterm infants with gestational age <29 weeks
Background Serum lactate levels are used as biomarkers for perinatal asphyxia, while their value for outcome prediction in preterm infants is uncertain. It was the aim of this observational study to determine the association of the first postnatal serum-lactate levels on day 1 of life and short-term outcome in preterm infants less than 29 gestational weeks. Methods We analysed data in a population-based cohort of German Neonatal Network (GNN) preterm infants with available first postnatal lactate levels enrolled at 22–28 weeks of gestational age (GA) between 1st of April 2009 and 31st December 2020. We hypothesized that high lactate levels as measured in mmol/L increase the risk of intraventricular haemorrhage (IVH) and bronchopulmonary dysplasia (BPD) in infants with VLBW regardless of small-for-gestational-age (SGA) status. Hypotheses were evaluated in univariate analyses and multiple logistic regression models. Results First postnatal lactate levels were available in 2499 infants. The study population had a median GA of 26.7 [IQR 25.2–27.9] weeks and birth weight of 840 g [IQR 665–995]. Infants with short-term complications such as IVH and BPD had higher initial lactate levels than non-affected infants. The positive predictive value of a lactate cut-off of 4 mmol/L was 0.28 for IVH and 0.30 for BPD. After adjustment for known confounding variables, each 1 mmol/L increase of day 1 lactate levels was associated with a modestly increased risk of IVH (OR 1.18; 95% CI 1.03–1.37; p = 0.002) and BPD (OR 1.23; 95% CI 1.06–1.43; p = 0.005) but not with sepsis or mortality. Notably, SGA was associated with lower risk of any grade and severe IVH (OR 0.70; 95% CI 0.54–0.85; p = 0.001). Conclusions In our observational cohort study higher initial lactate levels were associated with adverse outcome regardless of SGA status. However, the predictive value of lactate cut-off levels such as 4 mmol/L is low
A Genotype/Phenotype Study of KDM5B-Associated Disorders Suggests a Pathogenic Effect of Dominantly Inherited Missense Variants
Bi-allelic disruptive variants (nonsense, frameshift, and splicing variants) in KDM5B have been identified as causative for autosomal recessive intellectual developmental disorder type 65. In contrast, dominant variants, usually disruptive as well, have been more difficult to implicate in a specific phenotype, since some of them have been found in unaffected controls or relatives. Here, we describe individuals with likely pathogenic variants in KDM5B, including eight individuals with dominant missense variants. This study is a retrospective case series of 21 individuals with variants in KDM5B. We performed deep phenotyping and collected the clinical information and molecular data of these individuals’ family members. We compared the phenotypes according to variant type and to those previously described in the literature. The most common features were developmental delay, impaired intellectual development, behavioral problems, autistic behaviors, sleep disorders, facial dysmorphism, and overgrowth. DD, ASD behaviors, and sleep disorders were more common in individuals with dominant disruptive KDM5B variants, while individuals with dominant missense variants presented more frequently with renal and skin anomalies. This study extends our understanding of the KDM5B-related neurodevelopmental disorder and suggests the pathogenicity of certain dominant KDM5B missense variants
Histone H3.3 beyond cancer: Germline mutations in Histone 3 Family 3A and 3B cause a previously unidentified neurodegenerative disorder in 46 patients
Although somatic mutations in Histone 3.3 (H3.3) are well-studied drivers of oncogenesis, the role of germline mutations remains unreported. We analyze 46 patients bearing de novo germline mutations in histone 3 family 3A (H3F3A) or H3F3B with progressive neurologic dysfunction and congenital anomalies without malignancies. Molecular modeling of all 37 variants demonstrated clear disruptions in interactions with DNA, other histones, and histone chaperone proteins. Patient histone posttranslational modifications (PTMs) analysis revealed notably aberrant local PTM patterns distinct from the somatic lysine mutations that cause global PTM dysregulation. RNA sequencing on patient cells demonstrated up-regulated gene expression related to mitosis and cell division, and cellular assays confirmed an increased proliferative capacity. A zebrafish model showed craniofacial anomalies and a defect in Foxd3-derived glia. These data suggest that the mechanism of germline mutations are distinct from cancer-associated somatic histone mutations but may converge on control of cell proliferation
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Zigzag normalisation for associative n-categories
The theory of associative -categories has recently been
proposed as a strictly associative and unital approach to
higher category theory. As a foundation for a proof assistant,
this is potentially attractive, since it has the potential to allow
simple formal proofs of complex high-dimensional algebraic
phenomena. However, the theory relies on an implicit term
normalisation procedure to recognize correct composites,
with no recursive method available for computing it.
Here we describe a new approach to term normalisation
in associative -categories, based on the categorical zigzag
construction. This radically simplifies the theory, and yields
a recursive algorithm for normalisation, which we prove
is correct. Our use of categorical lifting properties allows
us to give efficient proofs of our results. Our normalisation
algorithm forms a core component of a proof assistant, and
we illustrate our scheme with worked examples
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A type theory for strictly unital infinity-categories
We use type-theoretic techniques to present an algebraic
theory of∞-categories with strict units. Starting with a known
type-theoretic presentation of fully weak ∞-categories, in
which terms denote valid operations, we extend the theory
with a non-trivial definitional equality. This forces some
operations to coincide strictly in any model, yielding the
strict unit behaviour.
We make a detailed investigation of the meta-theoretic
properties of this theory. We give a reduction relation that
generates definitional equality, and prove that it is confluent
and terminating, thus yielding the first decision procedure
for equality in a strictly-unital setting. Moreover, we show
that our definitional equality relation identifies all terms
in a disc context, providing a point comparison with a
previously proposed definition of strictly unital ∞-category.
We also prove a conservativity result, showing that every
operation of the strictly unital theory indeed arises from a
valid operation in the fully weak theory. From this, we infer
that strict unitality is a property of an ∞-category rather
than additional structure
