bluuebunny/crossref_metadata_2025 huggingface dataset:
Intersection theory of nefb-divisor classes
Authors: Dang Nguyen-Bac , Favre Charles
Published: September 2022

We prove that any nef$b$-divisor class on a projective variety defined over an algebraically closed field of characteristic zero is a decreasing limit of nef Cartier classes. Building on this technical result, we construct an intersection theory of nef$b$-divisors, and prove several variants of the Hodge index theorem inspired by the work of Dinh and Sibony. We show that any big and basepoint-free curve class is a power of a nef$b$-divisor, and relate this statement to the Zariski decomposition of curves classes introduced by Lehmann and Xiao. Our construction allows us to relate various Banach spaces contained in the space of$b$-divisors which were defined in our previous work.
On p-adic uniformization of abelian varieties with good reduction
Authors: Iovita Adrian , Morrow Jackson S. , Zaharescu Alexandru
Published: September 2022

Let $p$ be a rational prime, let $F$ denote a finite, unramified extension of ${{\mathbb {Q}}}_p$, let $K$ be the maximal unramified extension of ${{\mathbb {Q}}}_p$, ${{\overline {K}}}$ some fixed algebraic closure of $K$, and ${{\mathbb {C}}}_p$ be the completion of ${{\overline {K}}}$. Let $G_F$ be the absolute Galois group of $F$. Let $A$ be an abelian variety defined over $F$, with good reduction. Classically, the Fontaine integral was seen as a Hodge–Tate comparison morphism, i.e. as a map $\varphi _{A} \otimes 1_{{{\mathbb {C}}}_p}\colon T_p(A)\otimes _{{{\mathbb {Z}}}_p}{{\mathbb {C}}}_p\to \operatorname {Lie}(A)(F)\otimes _F{{\mathbb {C}}}_p(1)$, and as such it is surjective and has a large kernel. This paper starts with the observation that if we do not tensor $T_p(A)$ with ${{\mathbb {C}}}_p$, then the Fontaine integral is often injective. In particular, it is proved that if $T_p(A)^{G_K} = 0$, then $\varphi _A$ is injective. As an application, we extend the Fontaine integral to a perfectoid like universal cover of $A$ and show that if $T_p(A)^{G_K} = 0$, then $A(\overline {K})$ has a type of $p$-adic uniformization, which resembles the classical complex uniformization.
Parent and carer experiences of health care professionals’ communication about childhood obesity: a qualitative systematic review protocol
Authors: Koivumäki Terhi , Kääriäinen Maria , Tuomikoski Anna-Maria , Kaunonen Marja
Published: September 2022

Objective:

The objective of the systematic review is to identify, critically appraise, and synthesize the best available qualitative evidence on parent and carer experiences of health care professionals’ communication about childhood obesity.

Introduction:

Parents and carers play a key role in a child’s environment and healthy development, which is why they can find it confronting to discuss their child’s weight. This review will provide an insight into the experiences of parents and carers with health care professionals’ communication about their child's overweight or obesity.

Inclusion criteria:

This qualitative review will consider participants who are parents and carers with a child with overweight or obesity (birth to 12 years). The phenomenon of interest is parents’ and carers’ lived experiences of childhood obesity communication from a health care professional, and the context is health care settings. Communication includes verbal or written communication about a child's obesity from health care professionals received by a parent or carer.

Methods:

The proposed review will systematically search the following databases: MEDLINE (EBSCO), CINAHL (EBSCO), PsycINFO (Ovid), Scopus, LILACS, and the Finnish health sciences database MEDIC. ProQuest Dissertations and Theses (ProQuest) will be searched for unpublished articles. A manual search will supplement the database searches. The quality of included studies will be assessed independently by 2 reviewers, and the qualitative data will be extracted from papers by 2 independent reviewers using the standardized JBI data extraction tool. The recommended JBI approach to critical appraisal, study selection, data extraction, and data synthesis meta-aggregation will be used.

Systematic review registration number:

PROSPERO CRD42022297709
Calidad de la vivienda en Lima metropolitana. Índice, satisfacción y propuesta de un instrumento
Authors: Sánchez Barrera Julio César , Valdivia Loro Arturo
Published: September 2022

Este artículo presenta el estudio de la situación actual de la vivienda en Lima metropolitana, enfocándose en su calidad y en la satisfacción originada por ella, siendo esta en Perú la ciudad con mayor cifra poblacional, mayor cantidad de viviendas provenientes de la autoconstrucción y carencia de suelo para construir nuevas. Para ello se diseñaron dos instrumentos que evalúan cada variable, y se construyó y validó un modelo estadístico que permite medir la relación de las variables y estimar el índice de calidad de vivienda de Lima Metropolitana, llevando la investigación por una línea cuantitativa, transversal y no experimental. El estudio constató la relación directa que existe entre las variables y determinó el estado actual de cada una. Además, permitió jerarquizar las dimensiones de la satisfacción por calidad de vivienda.
Investigation of Gas Turbine Internal Cooling Using Supercritical CO2—Effect of Surface Roughness and Channel Aspect Ratio
Authors: Roy Arnab , Searle Matthew , Ramesh Sridharan , Straub Douglas
Published: September 2022

In this paper, an experimental and numerical investigation of internal cooling channels with rib turbulators is presented with sCO2 as the working fluid at process conditions (pressure-20.7 MPa and temperature up to 150 °C). The effect of channel aspect ratio up to 2:1 on thermal-hydraulic performance is explored in additively manufactured rectangular channels and square channels, both with and without 60 deg ribs on the top and bottom sides. The Wilson-plot method is employed to experimentally measure channel-averaged Nusselt number over a Reynolds number range up to 370,000. The friction factor is calculated from pressure drop and mass flow rate and additionally, the overall thermal performance factor (TPF) is reported. A companion computational fluid dynamics (CFD) simulation is performed for the rib turbulated cooling configurations reported in the experiments using the Reynolds average Navier–Stokes-based turbulence model. The objective of the numerical study is to gain insight into the local heat transfer augmentation in the ribbed channels as a result of varying the aspect ratio, channel configuration (square versus rectangular), operating conditions (Reynolds number) and the surface roughness, an inherent outcome of the additive manufacturing process. Surface roughness is simulated using sand grain roughness height (KS) calculated from the experimental data, and a comparison is presented with the corresponding channel configuration with varying surface roughness heights starting from smooth surfaces (KS = 0). Experimental results indicate that the heat transfer augmentation is negligible in the rectangular channels with ribs on the long side compared to the square channel. However, it is enhanced by 60% in comparison to placing ribs on the shorter side. The TPF remains constant at around 1 for the entire range of Reynolds numbers consistent with prior work at the National Energy Technology Laboratory (NETL). The simulation results highlight that increased surface roughness can have a favorable considerable influence on Nusselt number and overall thermal performance enhancement.
Film Cooling and Cold Streaks Tracking on a Fully Cooled Nozzle Guide Vane Under Representative Combustor Outflow Conditions
Authors: Babazzi G. , Bacci T. , Picchi A. , Facchini B. , Cubeda S.
Published: September 2022

The pronounced nonuniform temperature distribution in the core engine flow path is a recurring problem of gas turbine engine design process. Specifically, turbine entry conditions are usually characterized by severe temperature distortions, often referred to as hot and cold streaks, ascribed to combustor burners and combustor liners cooling systems. Temperature distortions remain an issue even at the exit section of the nozzle guide vane (NGV), where additional cold streaks coming from the vane film-cooling system are injected into the flow. A precise knowledge of thermal field and its evolution is thus essential to mitigate their impact on turbine performance and lifetime. Various studies focus on the description of streaks migration through a direct investigation of the thermal field, providing an effective evaluation of the global phenomenon. As a deeper understanding is often required, experimental techniques based on the detection of tracer gases can be successfully adopted. In this study, a realistic combustor outlet swirl profile was imposed on a fully cooled NGV cascade to analyze both film-cooling behavior and cold streaks migration and redirection. A concentration probe based on the fluorescence behavior of an oxygen sensor, fully characterized in a previous work, was here employed to track the position of the film cooling flows at the NGV cascade exit plane, while the adiabatic film-cooling effectiveness was evaluated on the NGV surfaces employing the pressure sensitive paint (PSP) technique. Overall, the swirling structure strongly affects both the film-cooling behavior and cold streaks migration through and downstream the vane. The importance of examining the unsteady aspect is also highlighted to better estimate actual components operating temperatures. A global understanding of the occurring phenomena is therefore provided, as well as significant pieces of information that can be extremely useful for the design phases of both the NGV and the following rotor cascade.
Gait Phase Detection in Walking and Stairs Using Machine Learning
Authors: Bauman Valerie V. , Brandon Scott C. E.
Published: September 2022

Machine learning-based activity and gait phase recognition algorithms are used in powered motion assistive devices to inform control of motorized components. The objective of this study was to develop a supervised multiclass classifier to simultaneously detect activity and gait phase (stance, swing) in real-world walking, stair ascent, and stair descent using inertial measurement data from the thigh and shank. The intended use of this algorithm was for control of a motion assistive device local to the knee. Using data from 80 participants, two decision trees and five long short-term memory (LSTM) models that each used different feature sets were initially tested and evaluated using a novel performance metric: proportion of perfectly classified strides (PPCS). Based on the PPCS of these initial models, five additional posthoc LSTM models were tested. Separate models were developed to classify (i) both activity and gait phase simultaneously (one model predicting six states), and (ii) activity-specific models (three individual binary classifiers predicting stance/swing phases). The superior activity-specific model had an accuracy of 98.0% and PPCS of 55.7%. The superior six-phase model used filtered inertial measurement data as its features and a median filter on its predictions and had an accuracy of 92.1% and PPCS of 22.9%. Pooling stance and swing phases from all activities and treating this model as a binary classifier, this model had an accuracy of 97.1%, which may be acceptable for real-world lower limb exoskeleton control if only stance and swing gait phases must be detected. Keywords: machine learning, deep learning, inertial measurement unit, activity recognition, gait.
Numerical Investigation of Air Entrainment and Outlet Temperature Characteristics of a Convex-Type Infrared Suppression Device
Authors: Mishra Sachin K. , Barik Ashok K.
Published: September 2022

Infrared suppression devices (IRS) are frequently used in naval/cargo ships to passively entrain an additional amount of cold air from the atmosphere, and mix it with the hot plume so as to suppress its temperature, and the IR signature. In this work, a convex-type IRS device has been proposed consisting of five numbers of the convex-type funnels. The air entrainment ratio has been numerically computed by solving the transport equations (i.e., mass, momentum, energy, turbulent kinetic energy, and its dissipation rate in a structured grid arrangement by employing a pressure-based finite volume solver in ansysfluent. The pertinent parameters like the Reynolds number, inlet temperature ratio, convex-radius ratio, and funnel-overlap height have been varied in the range of −1.5 × 105 to 1.5 × 106, 1.243 to 2.576, 0.834 to 1, and 0 to 0.326, respectively. It has been observed that the air entrainment ratio increases with both the Reynolds number and convex-radius ratio for the considered temperature ratios. An optimum convex-radius ratio (=0.909) has been obtained, where the air entrainment and the outlet temperature become the maximum and the minimum, respectively. Both the inlet temperature ratio and overlap height significantly improve intake of cold air into the IRS device due to the additional buoyancy force, and the enhanced area availability for air the ingestion. The convex-type IRS device performs better than a cylindrical-type IRS device. A nonlinear regression model based on the Levenberg-Marquardt (L-M) method has been deployed to develop a correlation equation for the air entrainment.
Mechanical Profile of Smooth Cellular Materials
Authors: Rastegarzadeh Sina , Muthusamy Samuel , Huang Jida
Published: September 2022

Cellular materials are critical elements for mechanical metamaterials design and fabrication. Tailoring the internal cellular material structural pattern can achieve a much broader range of bulk properties than the constituent materials, thus enabling the metamaterial design with extraordinary properties. Studying cellular materials’ mechanical properties is critical for understanding metamaterials’ structural design, and macroscale performances. This paper investigates and validates the mechanical properties of two classes of smooth cellular structures defined by deterministic and stochastic functions, respectively. A mechanical profile is proposed to depict the effective mechanical properties of these smooth cellular structures. We developed such profiles numerically based on computational homogenization and validated them by simulations and physical tests. In physical tests, we printed the generated structures on a fused deposition modeling (FDM) printer and conducted compression tests to verify the numerical homogenization and simulation results. Through the comparison studies, we summarize these cellular materials’ mechanical profiles defined by distinct principles. Based on the experimental results, several cellular structural design guidelines are derived for mechanical metamaterials development, which provides foundations for cellular materials database establishment and sheds light on future exotic metamaterials fabrication.
Mechanism of Axial Compressor Tip Clearance Noise Based on Taylor–Couette Flow Rotating Instability
Authors: Joe Beom-Jin , Kim Min-Hyeok , Hong Suk-Yoon , Song Jee-Hun
Published: September 2022

Prediction of the tip clearance noise (TCN) of axial compressors is essential to accurately determine the noise level of the compressor, because it is left unattenuated during propagation. The existing studies on numerical methods are inadequate for accurate determination of the TCN owing to the limited understanding of the physical phenomenon. The most convincing explanation is that the TCN is generated because of the instability in shear waves in the tip clearance region. In this study, the rotating instability theory was developed further by modeling the physical phenomenon of the instability as a Taylor–Couette (T–C) flow. The TCN sources were obtained using T–C flow modeling, and duct noise analysis was performed to obtain the TCN at various locations and frequencies. The TCN predictions were compared with the existing experimental results and noise results obtained using FW–H. Results showed that the T–C flow modeling is sufficiently accurate for predicting the frequencies, wavenumber distributions, and SPL of the tip clearance noise of axial compressors.
Frequency Lock-In Phenomenon of Vortex Induced Vibration of a Rotating Blade Considering Bending-Torsion Coupling Effect
Authors: Ren Yuankai , Lu Jianwei , Deng Gaoming , Wu Bofu , Zhou Dinghua
Published: September 2022

A rotating thin blade with bend-torsional coupling subjected to vortex induced vibration (VIV) is considered in this paper. It is necessary to study the motion coupled bending torsion due to the discordant centroid and shear center and the effect of centrifugal force at high-speed. The blade with a single axisymmetric section is regarded as a beam instead of an oscillator. The motion equation coupled bending-torsion of the blade is established by using the Euler–Lagrange equations, and the effect of centrifugal force is also employed. Vortex shedding is described by a nonlinear oscillator satisfying Van Der Pol (VDP) equation. Ritz–Galerkin method is employed to simplify the equations of the blade, and the interaction between the bending and torsion modes of blade and wake modes is discussed. The motion equation is simplified based on the contribution of the blade flutter mode. Furthermore, the single-mode approximation is used to investigate the effects of mass ratio, damping, and coupling coefficient on the locking phenomenon. It is also analyzed that the variation of flutter amplitude and locking region of the rotating blade considering bending-torsion coupling.
APROXIMACIÓN A LA ANTROPOLOGÍA VISUAL: IMÁGENES DE LA CARTELERÍA DE RIÑAS DE GALLOS EN CANARIAS.
Authors:   EIDUNED / UNED, MIRELES BETANCOR FRANCISCO
Published: September 2022

Rose Gillian, en su libro Metodologías Visuales, plantea varios métodos para el análisis de imágenes que pueden ser de gran valor para interpretar una sociedad cambiante como «marco para debatir la cultura visual contemporánea y los métodos para interpretarla», (2019:27). A partir de una pregunta de investigación, como es qué factores de repetición se dan en los carteles emitidos por la Federación Gallística de Canarias para sus campeonatos de riñas anuales, se intenta descubrir 1) los conceptos y valores que encierra el mundo gallístico y qué quieren proyectar al público; 2) cómo las imágenes visuales de los carteles reproducen en realidad las convenciones visuales; 3) o las relaciones de poder que definen lo que es representable. Los métodos elegidos inicialmente fueron: la interpretación composicional, el análisis de contenido y analítica cultural, y la semiología, con el objeto de aproximarnos a diferentes lecturas de las composiciones que desvelen los conceptos y valores del denominado “mundo gallístico”. El objetivo metodológico es «pensar los materiales visuales en función de cuatro lugares: el lugar de producción; el lugar de la imagen; los espacios de su circulación; y el lugar donde el espectador encuentra la imagen o recepción» (Gillian, 2019:71).
Visões de vanguarda, imaginários sociotécnicos e imaginação social: Uma reflexão crítica sobre a economia política da promessa da nova biomedicina
Authors:   Faculdade de Ciências Sociais e Humanas – Universidade Nova de Lisboa (Dep. Antropologia), Pinto Costa José Carlos ,   Centro em Rede de Investigação em Antropologia (FCSH-UNL)
Published: September 2022

O incremento de sinais de bioconvergência, isto é, de associação entre corpos, tecnologias e meios de comunicação digital, tem sido entendido pelos campeões da promessa que lideram as vanguardas tecnocientíficas e políticas como sinais inequívocos da materialização da revolução biotecnológica que tinha sido anunciada nos finais do século XX. A aceleração da produção de novos conceitos e discursividades e de tecnologias inovadoras que prometem transformar radicalmente a nossa relação com os profissionais e as instituições de saúde, e até com os nossos corpos e subjetividades, promove, porém, projeções opostas sobre o futuro. Visões utópicas alimentadas no que Ernst Bloch chamaria de princípio da esperança e visões distópicas que apontam a uma sintomatologia da discriminação e da exclusão das populações mais carentes e necessitadas que experimentam dificuldades de acesso às “maravilhas” da tecnologia aparecem lado a lado na imaginação dos cuidados de saúde do futuro e da própria sociedade. Sheila Jasanoff identificou três questões fundamentais que interferem na coprodução dos futuros no contexto da economia política da promessa: a predominância de organizações privadas na articulação e propagação dos imaginários; a existência de tensões sobre a definição dos futuros desejáveis; e a qualidade dos imaginários enquanto tradutores dos entendimentos de uma sociedade sobre o bem e o mal. A presente comunicação propõe refletir sobre as implicações da economia política da promessa da nova biomedicina na produção dos futuros imaginados analisando estas três questões através de uma abordagem cosmopolítica, isto é, partindo da indagação: “o que é que estamos a fazer?”.
Direct constraints on in situ stress state from deep drilling into the Nankai subduction zone, Japan
Authors: Tobin Harold J. , Saffer Demian M. , Castillo David A. , Hirose Takehiro
Published: September 2022

Stress state is a long-sought but poorly known parameter on subduction megathrusts and in overlying accretionary wedges in general. We used direct observations made during drilling of Integrated Ocean Drilling Program (IODP) borehole C0002 to a depth of 3058 m below the seafloor (mbsf) in the Nankai subduction zone of southwestern Japan to constrain in situ pore pressure and stress state in the deep interior of an accretionary wedge for the first time. These data included downhole pressure, active pumping tests, and logging and sample measurements. We found a nearly linear gradient in minimum horizontal principal stress (Shmin) and show that it remained consistently smaller than the vertical stress (Sv), definitively ruling out a thrust-faulting stress regime to at least 3 km depth, and to within ~2 km above the subduction megathrust. At 3000 mbsf, the estimated effective stresses were: Sv = 33 MPa, SHmax = 25–36 MPa, and Shmin = 18.5–21 MPa. We therefore interpret that the stress state throughout the drilled interval, which lies entirely in the hanging wall of the active megathrust, lies in a normal or strike-slip faulting regime (Sv ≥ SHmax > Shmin). Total differential stresses are below ~18 MPa. We conclude that (1) basal traction along the megathrust must be small in order to permit both locking (and frictional sliding at failure) of the décollement and such low differential stresses deep within the upper plate; and (2) although differential stresses may remain low all the way to the plate boundary at ~5000 mbsf, SHmax must transition to become greater than the vertical stress—either spatially below the base of the borehole or temporally leading up to megathrust fault rupture—in order to drive thrust motion along the plate boundary as observed in great earthquakes and in recurring very low-frequency earthquakes and slow-slip events.
Early accretion and prolonged carbonation of the Pacific Ocean's oldest crust
Authors: Kendrick Mark A. , Zhao Jianxin , Feng Yuexing
Published: September 2022

Newly formed oceanic crust is altered by seawater and carbonated at low temperatures over poorly defined periods of time. We applied in situ U-Pb dating to investigate 28 carbonate veins from Ocean Drilling Program Hole 801C, which is situated in the oldest Jurassic-age oceanic crust preserved in the western Pacific Ocean. Our results indicate that Pacific Ocean crust began accreting at 192 ± 6 Ma, which is ~25 m.y. earlier than previously recognized. Carbonation peaked at 171 ± 5 Ma and continued at a low rate for more than ~65 m.y. after accretion. Jurassic carbonation rates varied over ~10 m.y. timescales but encompassed a range similar to that observed today. These data suggest that carbonation rates are relatively insensitive to changes in atmospheric CO2, but confirm the longevity of seafloor alteration as a critical control in global volatile cycling.
Osmium isotopes fingerprint mantle controls on the genesis of an epithermal gold province
Authors: Tassara Santiago , Rooney Alan D. , Ague Jay. J. , Guido Diego , Reich Martin , Barra Fernando , Navarrete César
Published: September 2022

The formation of crustal blocks enriched with gold (Au) deposits above subduction zones is intimately bound to the genesis and evolution of magmatic-hydrothermal systems. A long-standing question, however, is whether the metal fertility of these systems stems from distinct sources that are anomalously enriched in Au or from subsequent processes occurring during crustal magma emplacement and hydrothermal activity. The Deseado Massif auriferous province in southern Patagonia (Argentina) is a unique place to test these contrasting hypotheses because Au-bearing mantle xenoliths indicate the presence of an underlying Au-rich lithospheric mantle reservoir. However, direct geochemical links between the Au-rich mantle source and the formation of the Deseado Massif auriferous province in the overlying crust remain to be established. To address this prominent gap in knowledge, we used sulfide Re-Os geochronology to identify the source of Au at Cerro Vanguardia, the largest low-sulfidation epithermal Au-Ag deposit in the Deseado Massif. Pyrite from high-grade Au quartz veins yielded an isochron age of 147.4 ± 2.9 Ma (mean square of weighted deviates = 1.04, n = 8) and an initial 187Os/188Os ratio of 0.26 ± 0.01, fingerprinting a dominant mantle control for the source of Os and, by inference, the source of Au. Our data provide a unique geochemical linkage between an Au-rich subcontinental lithospheric mantle source and the genesis of epithermal Au deposits, supporting the hypothesis that pre-enriched mantle domains may be a critical factor underpinning the global-scale localization of Au provinces.
Large-scale lava dome fracturing as a result of concealed weakened zones
Authors: Harnett Claire E. , Heap Michael J. , Troll Valentin R. , Deegan Frances M. , Walter Thomas R.
Published: September 2022

Mechanically weakened alteration zones in lava domes are thought to jeopardize their stability. Such zones can be hazardous when concealed within the dome, either because they formed by subsurface hydrothermal circulation or because they formed on the surface but were subsequently buried by renewed lava extrusion. We present a new suite of computational models showing how the size and position of a weakened brittle zone within a dome can affect large-scale fracture formation, displacement, and the collapse mechanism. By combining recent laboratory data for the mechanical behavior of dome rocks with discrete element method models, we show (1) the presence of a weak zone increases instability, which is exacerbated when the size of the zone increases or the zone is positioned off-center; (2) the position of the weak zone changes the deformation mechanism from slumping-type slope deformation when the zone is positioned centrally, compared with deep-seated rotational slope failure when the zone is positioned toward the dome flank; and finally, (3) dome-cutting tensile fractures form in the presence of a small weak zone (60 m diameter, ∼14% of dome width), whereas large weak zones (120 m diameter, ∼27% of dome width) promote the formation of longer and deeper fractures that jeopardize larger dome volumes. Our results corroborate previous field observations at lava domes and indicate that large fracture formation, which greatly influences dome stability and outgassing, can be explained by the presence of concealed alteration zones. This improved understanding of the mechanisms responsible for dome instability enables better hazard assessment at volcanoes worldwide.
Laryngeal mask airway versus face mask ventilation or intubation for neonatal resuscitation in low-and-middle-income countries: a systematic review and meta-analysis
Authors: Diggikar Shivashankar , Krishnegowda Roshani , Nagesh Karthik N , Lakshminrusimha Satyan , Trevisanuto Daniele
Published: September 2022

Objective

To assess whether laryngeal mask airway (LMA) as compared with face mask (FM) or endotracheal intubation (ETT) is more effective in delivering positive pressure ventilation (PPV) during neonatal resuscitation in low-and-middle income countries (LMICs).

Study design

We followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and searched Medline (PubMed interphase), Cumulative Index of Nursing and Allied Health Literature, Embase and Cochrane Registry between January 1990 and April 2022 for the studies that examined the effect of LMA in delivering PPV compared with the FM or ETT in infants during neonatal resuscitation. We included the studies conducted in LMIC only. We assessed the quality of all the included studies using GRADE (Grading of Recommendations Assessment, Development, and Evaluation) recommendations.

Results

Our search resulted in eight randomised studies Six studies compared LMA with FM and three studies compared LMA with ETT. When used as the primary device for providing PPV, the LMA as compared with FM resulted in a significant lower failure rate (relative risk (RR) 0.23, 95% CI 0.13 to 0.43) with moderate certainty of evidence (CoE) and lesser need for intubation (RR 0.21, 95% CI 0.07 to 0.58) with low CoE. There was no difference in the incidence of encephalopathy, neonatal admission, need for advanced resuscitations or death. No differences were observed between LMA and ETT. Studies comparing LMA to ETT were limited for any conceivable conclusion.

Conclusion

LMA is more effective than FM in delivering PPV with less failure rates and reduced need for intubation during neonatal resuscitation in term infants and in LMIC without any difference in the incidence of encephalopathy or death. Studies comparing LMA to ETT are scarce with important methodological limitations.

PROSPERO registration number

CRD42021283478.
Squamous cell carcinoma arising in a tailgut cyst: role of radiotherapy
Authors: Aldave Diego , Teijo Ana , Abril Claudia , Cerezo Laura
Published: September 2022

Tailgut cysts (TGCs) are rare tumours which can undergo malignant transformation. The gold standard of treatment is complete surgical excision. Multidisciplinary assessment is advisable in order to apply adjuvant treatment. Postoperative radiotherapy should be given in case of compromised surgical margins or other factors such as high histological grade or perineural and lymphovascular invasion. Here, we present a case of a squamous cell carcinoma arising from a retrorectal TGC treated with surgery and postoperative radiotherapy and review the main indications and techniques of this therapy.
Rare case of lingual nerve schwannoma of parapharyngeal space
Authors: Deewani Muhammad Hammad , Danish Muhammad Hassan , Awan Muhammad Sohail
Published: September 2022

Schwannoma of parapharyngeal space is an uncommon benign tumour of head and neck region. These are slow-growing and usually well-encapsulated masses arising from Schwann cells of cranial nerves. The majority of schwannoma in parapharyngeal space arise from vagus; however, cases have been reported with origin from other cranial nerves. Complete surgical excision is the treatment of choice. We recently experienced a case of schwannoma arising in parapharyngeal space of lingual nerve origin which was treated by transcervical excision.
Rectourethral fistula following focal irreversible electroporation for prostate cancer
Authors: Ong Sean , Alhamdani Zein , Lawrentschuk Nathan
Published: September 2022

A man in his 50s presented 4-week postirreversible electroporation (IRE) for low-to-intermediate risk prostate cancer with urinary symptoms, diarrhoea and passing fluid per rectum when urinating. Urine microscopy and sensitivities showed raised leucocytes, erythrocytes and pansensitiveEscherichia coli. A CT cystogram revealed a rectourethral fistula (RUF). Urinary diversion with insertion of an indwelling catheter for 6 weeks was performed. A rigid cystoscopy 6 weeks after urinary diversion revealed that the fistula was still present, confirmed by intraoperative contrast. The fistula was repaired with diathermy and a fibrin glue. The patient reported resolution of urinary and bowel symptoms. This is the first case report in the literature of an RUF following IRE for prostate cancer. It is important to report these rare complications as novel treatments become more common across the world.Background
Dementia clinical trials over the past decade: are women fairly represented?
Authors: Pinho-Gomes Ana-Catarina , Gong Jessica , Harris Katie , Woodward Mark , Carcel Cheryl
Published: September 2022

Background

Lack of progress in finding disease-modifying treatments for dementia may be due to heterogeneity in treatment effects among subgroups, such as by sex. Therefore, we investigated the characteristics of dementia trials completed in the last decade, with a focus on women’s representation and sex-disaggregated outcomes.

Methods

Clinical trials on dementia completed since 2010 were identified from ClinicalTrials.gov. Randomised, phase III/IV trials with ≥100 participants were selected to quantify women’s representation among participants, by computing the participation to prevalence ratio (PPR) and investigate whether sex-disaggregated analyses had been performed.

Results

A total of 1351 trials were identified between January 2010 and August 2021 (429 520 participants), of which 118 were eligible for analysis of women’s representation and sex-stratified analysis. Only 113 reported the sex of participants and were included in the analysis of women’s representation. Of the 110 469 participants in these 113 trials, 58% were women, lower than their estimated representation in the global dementia population of 64%. The mean PPR was 0.90 (95% CI 0.86 to 0.94). Women’s participation tended to be higher when the first or last authors of the trial report were women. Eight out of the 118 trials reported sex-disaggregated outcomes, and three of those found significant sex differences in efficacy outcomes. None of the trials reported screening failures or adverse events stratified by sex.

Conclusions

Overall, women and men were equally represented in dementia trials carried out over the past decade, but women’s representation was lower than in the underlying dementia population. Sex-disaggregated efficacy and safety outcomes were rarely reported.
Nationwide survey of Lambert-Eaton myasthenic syndrome in Japan
Authors: Yoshikawa Hiroaki , Adachi Yumi , Nakamura Yosikazu , Kuriyama Nagato , Murai Hiroyuki , Nomura Yoshiko , Sakai Yasunari , Iwasa Kazuo , Furukawa Yutaka , Kuwabara Satoshi , Matsui Makoto
Published: September 2022

Background

There was no nationwide epidemiological study of Lambert-Eaton myasthenic syndrome (LEMS) in Japan; therefore, we conducted a nationwide survey.

Methods

For the first survey, we sent survey sheets to randomly selected medical departments (n=7545) to obtain the number of LEMS who visited medical departments between 1 January 2017 and 31 December 2017. For the second survey, we sent survey sheets to the corresponding medical departments to obtain clinical information on LEMS.

Results

We received 2708 responses (recovery rate: 35.9%) to the first survey. We estimated the number of LEMS as 348 (95% CI 247 to 449). The prevalence was 2.7 (95% CI 1.9 to 3.5) in 1 000 000 population. As a result of the second survey, we obtained 30 case records of 16 men and 14 women. Fourteen patients (46.7%) had a tumour, and 10 out of 14 tumours were small-cell lung carcinoma (71.4%). There was a predominance of men in the LEMS with tumour (paraneoplastic LEMS, P-LEMS) (n=11, 78.6%) and women in the LEMS without tumour (a primary autoimmune form of LEMS, AI-LEMS) (n=11, 68.8%) (p=0.0136). The onset age (mean (SD)) for the P-LEMS was 67.1 (9.0), and that for AI-LEMS was 57.8 (11.2) years old (p=0.0103). The disease duration (median) for P-LEMS was 2 years, and for AI-LEMS was 7.5 years (p=0.0134).

Conclusions

The prevalence of LEMS in Japan is similar to that in other countries. There are predominances of men in P-LEMS and women in AI-LEMS.
Coping in the role as next of kin of a person with a brain tumour: a qualitative metasynthesis
Authors: Lien Anette Windsland , Rohde Gudrun
Published: September 2022

Objective

Being the next of kin of a person with a brain tumour is a stressful experience. For many, being a next of kin involves fear, insecurity and overwhelming responsibility. The purpose of this study was to identify and synthesise qualitative original studies that explore coping in the role as next of kin of a person with a brain tumour.

Methods

A qualitative metasynthesis guided by Sandelowski and Barroso’s guidelines was used. The databases Medline, CHINAL and PsycINFO were searched for studies from January 2000 to 18 January 2022. Inclusion criteria were qualitative original studies that aimed to explore coping experience by the next of kin of a person with brain tumour. The next of kin had to be 18 years of age or older.

Results

Of a total of 1476 screened records data from 20 studies, including 342 participants (207 females, 81 males and 54 unclassified) were analysed into metasummaries and a metasynthesis. The metasynthesis revealed that the next of kin coping experiences were characterised by two main themes: (1) coping factors within the next of kin and as a support system, such as their personal characteristics, perceiving the role as meaningful, having a support system, and hope and religion; (2) coping strategies—control and proactivity, including regaining control, being proactive and acceptance.

Conclusion

Next of kin of patients with brain tumours used coping factors and coping strategies gathered within themselves and in their surroundings to handle the situation and their role. It is important that healthcare professionals suggest and facilitate these coping factors and strategies because this may reduce stress and make the role of next of kin more manageable.
Efficiency of ER:YAG laser therapy in combination with behaviour management technique in reducing anxiety among paediatric dental patients – a study protocol for a randomised clinical trial
Authors: Belcheva Ani , Shindova Maria
Published: September 2022

Introduction

When providing dental care to children with a high level of dental anxiety, the range of approaches is divided into two sections: use of behaviour management techniques (BMTs) and application of alternative methods for caries removal. In an attempt to reduce dental anxiety, they can be mixed and matched in accordance with the dentists’ choice. Owing to its promoted advantages, erbium-doped yttrium aluminium garnet (Er:YAG) laser turns into an ideal alternative technique for hard dental tissue therapy in anxious paediatric patients. The aim of the study is to assess the efficacy of a modified version of the BMT ‘Latent inhibition’ in combination with Er:YAG laser for achieving a reduction of dental anxiety in paediatric dental patients.

Methods and analysis

This is a protocol for a randomised controlled clinical trial. The participants will be children aged 6–9 years, requiring conservative treatment of occlusal carious lesion on a second primary molar. Patients will be randomly assigned to the experimental or control group via a computer-generated sequence. In both groups, ‘Latent inhibition’ will be used as an anxiety-management technique. In the experimental group, caries treatment will be performed with Er:YAG laser, whereas that in the control group it will be performed with conventional rotary instruments. Outcome measures will be dental anxiety felt before and after the treatment, reported by the patient on a modified version of the Faces Scale by LeBaron et al., and the dynamics of heart rate, registered during the treatment session, which will be measured with a mobile pulse oximeter. Data will be analysed by independent sample t-test and paired t-test (p˂0.05).

Ethics and dissemination

The study protocol has been approved by the Committee for Scientific Research Ethics, Medical University–Plovdiv, Bulgaria (reference number P-2839, protocol of approval number 3/30.04.2015) and registered on a publicly accessible database. This research received institutional funding from the Medical University–Plovdiv, Bulgaria. The results will be presented through peer-reviewed publications and conference presentations.

Trial registration number

NCT04924452.
Sleep quality and associated factors among pregnant women attending antenatal care unit at Gondar, Ethiopia: a cross-sectional study
Authors: Takelle Girmaw Medfu , Muluneh Niguse Yigzaw , Biresaw Mengesha Srahbzu
Published: September 2022

Objective

This study aimed to determine the prevalence and associated factors of poor sleep quality among pregnant women in Ethiopia.

Method

Institutional based cross-sectional study.

Setting

University of Gondar Comprehensive Specialized Hospital, Gondar, Ethiopia.

Participants

A total of 415 pregnant women were recruited by using a systematic random sampling technique from 28 April 2020 to 12 June 2020.

Measurement

The desired data were collected through face-to-face interview technique by using validated questionnaires such as the Pittsburgh Sleep Quality Index, Edinburgh Postnatal Depression Scale, Perceived Stress Scale, Oslo-3 and Abuse Assessment Screen. The data were analysed by using SPSS V.20. Logistic regression analysis was used to identify associated factors with poor sleep quality. Variables having a p value of less than 0.2 in the bivariate analysis were entered to the multivariable logistic regression. A p value of less than 0.05 was considered statistically significant, at 95% CI.

Result

In this study, 175 (42.2%) pregnant women had poor sleep quality. According to multivariable logistic regression, being first and third trimesters of gestational age (adjusted OR (aOR) 2.31, 95% CI 1.16 to 4.61 and aOR 3.45, 95% CI 2.05 to 5.79, respectively), consumption of caffeinated substances (aOR 2.96, 95% CI 1.68 to 5.52), having depression (aOR 2.12, 95% CI 1.19 to 3.76), having high perceived stress (aOR 5.39, 95% CI 1.96 to 14.79) and experience of intimate partner violence (aOR 5.57, 95% CI 2.19 to 14.68) were positive significant associated factors with poor sleep quality.

Conclusion and recommendation

The prevalence of poor sleep quality among pregnant women was relatively high. First and third trimesters, consumption of caffeinated substances, antenatal depression, high perceived stress and intimate partner violence were factors significantly associated with poor sleep quality. This result suggests that all pregnant women should be screened and treated for poor sleep quality during the first and third trimesters.
Accounts of preventative coping: an interview study of stroke survivors on general practice registers
Authors: Scott Reid Peter , Neville Emma , Cater Frances , Mullis Ricky , Mant Jonathan , Duschinsky Robbie
Published: September 2022

Objectives

Preventative coping is an underexplored aspect of coping behaviour. Specifically, coping is a key concern in stroke survivor accounts, but this has yet to be investigated with reference to secondary prevention.

Design

Secondary analysis of a qualitative data set comprising semistructured interviews of 22 stroke survivors recruited from five general practices in the East of England. The topic guide included exploration of advice and support given by their doctor on medication and lifestyle. The interviews were coded using thematic analysis.

Results

The accounts emphasised individual responsibility. Two key themes were identified, which foregrounded the role of self-concept for coping: (a) striving to be ‘good’, (b) appeal to ideas of ‘personality’. In the former, preventative behaviour was depicted in moralistic terms, with the doctor as an adjudicator. In the latter, participants attributed their coping behaviour to their personality, which might help or hinder these efforts.

Conclusions

We highlight that coping was characterised by survivors as something enacted by the individual self, and consider how constructions of self may impact preventative coping efforts.
Development and validation of a dynamic 48-hour in-hospital mortality risk stratification for COVID-19 in a UK teaching hospital: a retrospective cohort study
Authors: Wiegand Martin , Cowan Sarah L , Waddington Claire S , Halsall David J , Keevil Victoria L , Tom Brian D M , Taylor Vince , Gkrania-Klotsas Effrossyni , Preller Jacobus , Goudie Robert J B
Published: September 2022

Objectives

To develop a disease stratification model for COVID-19 that updates according to changes in a patient’s condition while in hospital to facilitate patient management and resource allocation.

Design

In this retrospective cohort study, we adopted a landmarking approach to dynamic prediction of all-cause in-hospital mortality over the next 48 hours. We accounted for informative predictor missingness and selected predictors using penalised regression.

Setting

All data used in this study were obtained from a single UK teaching hospital.

Participants

We developed the model using 473 consecutive patients with COVID-19 presenting to a UK hospital between 1 March 2020 and 12 September 2020; and temporally validated using data on 1119 patients presenting between 13 September 2020 and 17 March 2021.

Primary and secondary outcome measures

The primary outcome is all-cause in-hospital mortality within 48 hours of the prediction time. We accounted for the competing risks of discharge from hospital alive and transfer to a tertiary intensive care unit for extracorporeal membrane oxygenation.

Results

Our final model includes age, Clinical Frailty Scale score, heart rate, respiratory rate, oxygen saturation/fractional inspired oxygen ratio, white cell count, presence of acidosis (pH <7.35) and interleukin-6. Internal validation achieved an area under the receiver operating characteristic (AUROC) of 0.90 (95% CI 0.87 to 0.93) and temporal validation gave an AUROC of 0.86 (95% CI 0.83 to 0.88).

Conclusions

Our model incorporates both static risk factors (eg, age) and evolving clinical and laboratory data, to provide a dynamic risk prediction model that adapts to both sudden and gradual changes in an individual patient’s clinical condition. On successful external validation, the model has the potential to be a powerful clinical risk assessment tool.

Trial registration

The study is registered as ‘researchregistry5464’ on the Research Registry (www.researchregistry.com).