1,970 research outputs found
Amplification schemes and multi-channel DBP for unrepeatered transmission
The performance of unrepeatered transmission of a seven Nyquist-spaced 10 GBd PDM-16QAM superchannel using full signal band coherent detection and multi-channel digital back propagation (MC-DBP) to mitigate nonlinear effects is analysed. For the first time in unrepeatered transmission, the performance of two amplification systems is investigated and directly compared in terms of achievable information rates (AIRs): 1) erbium-doped fibre amplifier (EDFA) and 2) second-order bidirectional Raman pumped amplification. The experiment is performed over different span lengths, demonstrating that, for an AIR of 6.8 bit/s/Hz, the Raman system enables an increase of 93 km (36 %) in span length. Further, at these distances, MC-DBP gives an improvement in AIR of 1 bit/s/Hz (to 7.8 bit/s/Hz) for both amplification schemes. The theoretical AIR gains for Raman and MC-DBP are shown to be preserved when considering low-density parity-check codes. Additionally, MC-DBP algorithms for both amplification schemes are compared in terms of performance and computational complexity. It is shown that to achieve the maximum MC-DBP gain, the Raman system requires approximately four times the computational complexity due to the distributed impact of fibre nonlinearity
Screening for Syphilis Infection in Nonpregnant Adults and Adolescents: US Preventive Services Task Force Recommendation Statement
Clinical Review & Education US Preventive Services Task Force | RECOMMENDATION STATEMENT Screening for Syphilis Infection in Nonpregnant Adults and Adolescents US Preventive Services Task Force Recommendation Statement US Preventive Services Task Force (USPSTF) Editorial page 2281 IMPORTANCE In 2014, 19 999 cases of syphilis were reported in the United States. Left untreated, syphilis can progress to late-stage disease in about 15% of persons who are infected. Late-stage syphilis can lead to development of inflammatory lesions throughout the body, which can lead to cardiovascular or organ dysfunction. Syphilis infection also increases the risk for acquiring or transmitting HIV infection. OBJECTIVE To update the 2004 US Preventive Services Task Force (USPSTF) recommendation on screening for syphilis infection in nonpregnant adults. Screening for syphilis in pregnant women was updated in a separate recommendation statement in 2009 (A recommendation). EVIDENCE REVIEW The USPSTF reviewed the evidence on screening for syphilis infection in asymptomatic, nonpregnant adults and adolescents, including patients coinfected with other sexually transmitted infections (such as HIV). Author Audio Interview at jama.com Related article page 2328 and JAMA Patient Page page 2367 CME Quiz at jamanetworkcme.com and CME Questions page 2342 Related articles at jamadermatology.com, jamaneurology.com, jamapediatrics.com FINDINGS The USPSTF found convincing evidence that screening for syphilis infection in asymptomatic, nonpregnant persons at increased risk for infection provides substantial benefit. Accurate screening tests are available to identify syphilis infection in populations at increased risk. Effective treatment with antibiotics can prevent progression to late-stage disease, with small associated harms, providing an overall substantial health benefit. CONCLUSIONS AND RECOMMENDATION The USPSTF recommends screening for syphilis infection in persons who are at increased risk for infection. (A recommendation) Authors/Group Information: The USPSTF members are listed at the end of the article. JAMA. 2016;315(21):2321-2327. doi:10.1001/jama.2016.5824 Corresponding Author: Kirsten Bibbins-Domingo, PhD, MD, MAS ([email protected]). T he US Preventive Services Task Force (USPSTF) makes recommendations about the effectiveness of specific preventive care services for patients without obvious related signs or symptoms. It bases its recommendations on the evidence of both the benefits and harms of the service and an assessment of the bal- ance. The USPSTF does not consider the costs of providing a ser- vice in this assessment. The USPSTF recognizes that clinical decisions involve more con- siderations than evidence alone. Clinicians should understand the evidence but individualize decision making to the specific patient or situation. Similarly, the USPSTF notes that policy and coverage decisions involve considerations in addition to the evidence of clini- cal benefits and harms. Summary of Recommendation and Evidence The USPSTF recommends screening for syphilis infection in per- sons who are at increased risk for infection. (A recommendation) (Figure 1) jama.com See the Clinical Considerations section later in this article for in- formation on risk factors for infection. Rationale Importance The number of cases of primary and secondary syphilis have been in- creasing since 2000. In 2014, 19 999 cases (6.3 cases per 100 000 persons)ofprimaryandsecondarysyphiliswerereportedintheUnited States. 1 Left untreated, syphilis can progress to late-stage disease in approximately 15% of persons who are infected. 2 Consequences of late-stage syphilis include development of inflammatory lesions throughout the body (eg, aortitis, gummatous lesions, and osteitis), which can lead to cardiovascular or organ dysfunction. Syphilis in- fection of the central nervous system (neurosyphilis) can occur at any stage of disease and can result in blindness, paresis, tabes dor- salis, and dementia. Syphilis infection also increases the risk for ac- quiring or transmitting HIV infection. The USPSTF addresses screening for syphilis in pregnant women in a separate recommendation statement. 3 (Reprinted) JAMA June 7, 2016 Volume 315, Number 21 Copyright 2016 American Medical Association. All rights reserved. Downloaded From: http://jamanetwork.com/ by a University of California - Los Angeles User on 09/21/201
Increased serum kallistatin levels in type 1 diabetes patients with vascular complications
BACKGROUND: Kallistatin, a serpin widely produced throughout the body, has vasodilatory, anti-angiogenic, anti-oxidant, and anti-inflammatory effects. Effects of diabetes and its vascular complications on serum kallistatin levels are unknown. METHODS: Serum kallistatin was quantified by ELISA in a cross-sectional study of 116 Type 1 diabetic patients (including 50 with and 66 without complications) and 29 non-diabetic controls, and related to clinical status and measures of oxidative stress and inflammation. RESULTS: Kallistatin levels (mean(SD)) were increased in diabetic vs. control subjects (12.6(4.2) vs. 10.3(2.8) Îźg/ml, p = 0.007), and differed between diabetic patients with complications (13.4(4.9) Îźg/ml), complication-free patients (12.1(3.7) Îźg/ml), and controls; ANOVA, p = 0.007. Levels were higher in diabetic patients with complications vs. controls, p = 0.01, but did not differ between complication-free diabetic patients and controls, p > 0.05. On univariate analyses, in diabetes, kallistatin correlated with renal dysfunction (cystatin C, r = 0.28, p = 0.004; urinary albumin/creatinine, r = 0.34, p = 0.001; serum creatinine, r = 0.23, p = 0.01; serum urea, r = 0.33, p = 0.001; GFR, r = -0.25, p = 0.009), total cholesterol (r = 0.28, p = 0.004); LDL-cholesterol (r = 0.21, p = 0.03); gamma-glutamyltransferase (GGT) (r = 0.27, p = 0.04), and small artery elasticity, r = -0.23, p = 0.02, but not with HbA1c, other lipids, oxidative stress or inflammation. In diabetes, geometric mean (95%CI) kallistatin levels adjusted for covariates, including renal dysfunction, were higher in those with vs. without hypertension (13.6 (12.3-14.9) vs. 11.8 (10.5-13.0) Îźg/ml, p = 0.03). Statistically independent determinants of kallistatin levels in diabetes were age, serum urea, total cholesterol, SAE and GGT, adjusted r2 = 0.24, p < 0.00001. CONCLUSIONS: Serum kallistatin levels are increased in Type 1 diabetic patients with microvascular complications and with hypertension, and correlate with renal and vascular dysfunction
The International Gene Trap Consortium Website: a portal to all publicly available gene trap cell lines in mouse
Gene trapping is a method of generating murine embryonic stem (ES) cell lines containing insertional mutations in known and novel genes. A number of international groups have used this approach to create sizeable public cell line repositories available to the scientific community for the generation of mutant mouse strains. The major gene trapping groups worldwide have recently joined together to centralize access to all publicly available gene trap lines by developing a user-oriented Website for the International Gene Trap Consortium (IGTC). This collaboration provides an impressive public informatics resource comprising âź45â000 well-characterized ES cell lines which currently represent âź40% of known mouse genes, all freely available for the creation of knockout mice on a non-collaborative basis. To standardize annotation and provide high confidence data for gene trap lines, a rigorous identification and annotation pipeline has been developed combining genomic localization and transcript alignment of gene trap sequence tags to identify trapped loci. This information is stored in a new bioinformatics database accessible through the IGTC Website interface. The IGTC Website () allows users to browse and search the database for trapped genes, BLAST sequences against gene trap sequence tags, and view trapped genes within biological pathways. In addition, IGTC data have been integrated into major genome browsers and bioinformatics sites to provide users with outside portals for viewing this data. The development of the IGTC Website marks a major advance by providing the research community with the data and tools necessary to effectively use public gene trap resources for the large-scale characterization of mammalian gene function
Consistency, completeness and external validity of ethnicity recording in NHS primary care records: a cohort study in 25 million patientsâ records at source using OpenSAFELY
Background: Ethnicity is known to be an important correlate of health outcomes, particularly during the COVID-19 pandemic, where some ethnic groups were shown to be at higher risk of infection and adverse outcomes. The recording of patientsâ ethnic groups in primary care can support research and efforts to achieve equity in service provision and outcomes; however, the coding of ethnicity is known to present complex challenges. We therefore set out to describe ethnicity coding in detail with a view to supporting the use of this data in a wide range of settings, as part of wider efforts to robustly describe and define methods of using administrative data. Methods: We describe the completeness and consistency of primary care ethnicity recording in the OpenSAFELY-TPP database, containing linked primary care and hospital records in > 25 million patients in England. We also compared the ethnic breakdown in OpenSAFELY-TPP with that of the 2021 UK census. Results: 78.2% of patients registered in OpenSAFELY-TPP on 1 January 2022 had their ethnicity recorded in primary care records, rising to 92.5% when supplemented with hospital data. The completeness of ethnicity recording was higher for women than for men. The rate of primary care ethnicity recording ranged from 77% in the South East of England to 82.2% in the West Midlands. Ethnicity recording rates were higher in patients with chronic or other serious health conditions. For each of the five broad ethnicity groups, primary care recorded ethnicity was within 2.9 percentage points of the population rate as recorded in the 2021 Census for England as a whole. For patients with multiple ethnicity records, 98.7% of the latest recorded ethnicities matched the most frequently coded ethnicity. Patients whose latest recorded ethnicity was categorised as Other were most likely to have a discordant ethnicity recording (32.2%). Conclusions: Primary care ethnicity data in OpenSAFELY is present for over three quarters of all patients, and combined with data from other sources can achieve a high level of completeness. The overall distribution of ethnicities across all English OpenSAFELY-TPP practices was similar to the 2021 Census, with some regional variation. This report identifies the best available codelist for use in OpenSAFELY and similar electronic health record data
Inferring transient dynamics of human populations from matrix non-normality
This is the final version of the article. Available from Springer Verlag via the DOI in this record.In our increasingly unstable and unpredictable world, population dynamics rarely settle uniformly to long-term behaviour. However, projecting period-by-period through the preceding fluctuations is more data-intensive and analytically involved than evaluating at equilibrium. To efficiently model populations and best inform policy, we require pragmatic suggestions as to when it is necessary to incorporate short-term transient dynamics and their effect on eventual projected population size. To estimate this need for matrix population modelling, we adopt a linear algebraic quantity known as non-normality. Matrix non-normality is distinct from normality in the Gaussian sense, and indicates the amplificatory potential of the population projection matrix given a particular population vector. In this paper, we compare and contrast three well-regarded metrics of non-normality, which were calculated for over 1000 age-structured human population projection matrices from 42 European countries in the period 1960 to 2014. Non-normality increased over time, mirroring the indices of transient dynamics that peaked around the millennium. By standardising the matrices to focus on transient dynamics and not changes in the asymptotic growth rate, we show that the damping ratio is an uninformative predictor of whether a population is prone to transient booms or busts in its size. These analyses suggest that population ecology approaches to inferring transient dynamics have too often relied on suboptimal analytical tools focussed on an initial population vector rather than the capacity of the life cycle to amplify or dampen transient fluctuations. Finally, we introduce the engineering technique of pseudospectra analysis to population ecology, which, like matrix non-normality, provides a more complete description of the transient fluctuations than the damping ratio. Pseudospectra analysis could further support non-normality assessment to enable a greater understanding of when we might expect transient phases to impact eventual population dynamics.This work was funded by Wellcome Trust New Investigator 103780 to TE, who is also funded by NERC Fellowship NE/J018163/1. JB gratefully acknowledges the ESRC Centre for Population Change ES/K007394/1
"I'm the Momma": Using photo-elicitation to understand matrilineal influence on family food choice
<p>Abstract</p> <p>Background</p> <p>Many complex and subtle aspects relating to mothers and food choice are not well understood. Mothers play a primary role in their children's food choices, but research has not specifically examined how matrilineal family members who do not reside in the same household, such as a mother's mother, aunt, or grandmother, influence the current family's food choices.</p> <p>Methods</p> <p>Seven participants were recruited from the Household Food Inventory (HFI) Study in the Bryan/College Station, Texas. All participants completed an in-depth interview, photographed food-related activities, and discussed photographs in a follow-up in-depth interview. Interviews were transcribed verbatim from audio recordings. Transcripts were analyzed using several qualitative approaches including grounded theory to identify themes and subthemes.</p> <p>Results</p> <p>Participants discussed the following themes relating to the influence of their mother or other female relation (Mom) on their families' food choices: Relationship with Mom, Just like Mom, 'Kinda' like Mom, Different than Mom, and Mom's Influence on Children's Food Choices. Overall, participants used the photographs to illustrate how they were similar or different to their mothers, or other female family member, as well as how their mothers either supported or undermined control over their children's food choices. The "Mom effect" or matrilineal influence of mothers, aunts, and grandmothers on a mother's food choices was omnipresent, even though Mom was no longer living with the participants.</p> <p>Conclusions</p> <p>We found a matrilineal influence to have a residual and persistent influence on a family's food choices. This finding may be helpful for understanding the contextual elements of food choice and explaining why it is sometimes difficult to change mothers' food habits.</p
HAWC+ Far-infrared Observations of the Magnetic Field Geometry in M51 and NGC 891
Abstract: Stratospheric Observatory for Infrared Astronomy High-resolution Airborne Wideband Camera Plus polarimetry at 154 Îźm is reported for the face-on galaxy M51 and the edge-on galaxy NGC 891. For M51, the polarization vectors generally follow the spiral pattern defined by the molecular gas distribution, the far-infrared (FIR) intensity contours, and other tracers of star formation. The fractional polarization is much lower in the FIR-bright central regions than in the outer regions, and we rule out loss of grain alignment and variations in magnetic field strength as causes. When compared with existing synchrotron observations, which sample different regions with different weighting, we find the net position angles are strongly correlated, the fractional polarizations are moderately correlated, but the polarized intensities are uncorrelated. We argue that the low fractional polarization in the central regions must be due to significant numbers of highly turbulent segments across the beam and along lines of sight in the beam in the central 3 kpc of M51. For NGC 891, the FIR polarization vectors within an intensity contour of 1500 are oriented very close to the plane of the galaxy. The FIR polarimetry is probably sampling the magnetic field geometry in NGC 891 much deeper into the disk than is possible with NIR polarimetry and radio synchrotron measurements. In some locations in NGC 891, the FIR polarization is very low, suggesting we are preferentially viewing the magnetic field mostly along the line of sight, down the length of embedded spiral arms. There is tentative evidence for a vertical field in the polarized emission off the plane of the disk
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