CHY representations for gauge theory and gravity amplitudes with up to three massive particles

We show that a wide class of tree-level scattering amplitudes involving scalars, gauge bosons, and gravitons, up to three of which may be massive, can be expressed in terms of a Cachazo-He-Yuan representation as a sum over solutions of the scattering equations. These amplitudes, when expressed in terms of the appropriate kinematic invariants, are independent of the masses and therefore identical to the corresponding massless amplitudes.Comment: 20 pages, 1 figure; v2: minor typos corrected, published versio

Second primary cancer risk - the impact of applying different definitions of multiple primaries: results from a retrospective population-based cancer registry study

Background: There is evidence that cancer survivors are at increased risk of second primary cancers. Changes in the prevalence of risk factors and diagnostic techniques may have affected more recent risks.<p></p> Methods: We examined the incidence of second primary cancer among adults in the West of Scotland, UK, diagnosed with cancer between 2000 and 2004 (n = 57,393). We used National Cancer Institute Surveillance Epidemiology and End Results and International Agency for Research on Cancer definitions of multiple primary cancers and estimated indirectly standardised incidence ratios (SIR) with 95% confidence intervals (CI).<p></p> Results: There was a high incidence of cancer during the first 60 days following diagnosis (SIR = 2.36, 95% CI = 2.12 to 2.63). When this period was excluded the risk was not raised, but it was high for some patient groups; in particular women aged <50 years with breast cancer (SIR = 2.13, 95% CI = 1.58 to 2.78), patients with bladder (SIR = 1.41, 95% CI = 1.19 to 1.67) and head & neck (SIR = 1.93, 95% CI = 1.67 to 2.21) cancer. Head & neck cancer patients had increased risks of lung cancer (SIR = 3.75, 95% CI = 3.01 to 4.62), oesophageal (SIR = 4.62, 95% CI = 2.73 to 7.29) and other head & neck tumours (SIR = 6.10, 95% CI = 4.17 to 8.61). Patients with bladder cancer had raised risks of lung (SIR = 2.18, 95% CI = 1.62 to 2.88) and prostate (SIR = 2.41, 95% CI = 1.72 to 3.30) cancer.<p></p> Conclusions: Relative risks of second primary cancers may be smaller than previously reported. Premenopausal women with breast cancer and patients with malignant melanomas, bladder and head & neck cancers may benefit from increased surveillance and advice to avoid known risk factors

The Soft-Collinear Bootstrap: N=4 Yang-Mills Amplitudes at Six and Seven Loops

Infrared divergences in scattering amplitudes arise when a loop momentum $\ell$ becomes collinear with a massless external momentum $p$. In gauge theories, it is known that the L-loop logarithm of a planar amplitude has much softer infrared singularities than the L-loop amplitude itself. We argue that planar amplitudes in N=4 super-Yang-Mills theory enjoy softer than expected behavior as $\ell \parallel p$ already at the level of the integrand. Moreover, we conjecture that the four-point integrand can be uniquely determined, to any loop-order, by imposing the correct soft-behavior of the logarithm together with dual conformal invariance and dihedral symmetry. We use these simple criteria to determine explicit formulae for the four-point integrand through seven-loops, finding perfect agreement with previously known results through five-loops. As an input to this calculation we enumerate all four-point dual conformally invariant (DCI) integrands through seven-loops, an analysis which is aided by several graph-theoretic theorems we prove about general DCI integrands at arbitrary loop-order. The six- and seven-loop amplitudes receive non-zero contributions from 229 and 1873 individual DCI diagrams respectively.Comment: 27 pages, 48 figures, detailed results including PDF and Mathematica files available at http://goo.gl/qIKe8 v2: minor corrections v3: figure 7 corrected, Lemma 2 remove

Dualities for Loop Amplitudes of N=6 Chern-Simons Matter Theory

In this paper we study the one- and two-loop corrections to the four-point amplitude of N=6 Chern-Simons matter theory. Using generalized unitarity methods we express the one- and two-loop amplitudes in terms of dual-conformal integrals. Explicit integration by using dimensional reduction gives vanishing one-loop result as expected, while the two-loop result is non-vanishing and matches with the Wilson loop computation. Furthermore, the two-loop correction takes the same form as the one-loop correction to the four-point amplitude of N=4 super Yang-Mills. We discuss possible higher loop extensions of this correspondence between the two theories. As a side result, we extend the method of dimensional reduction for three dimensions to five dimensions where dual conformal symmetry is most manifest, demonstrating significant simplification to the computation of integrals.Comment: 32 pages and 6 figures. v2: minus sign corrections, ref updated v3: Published versio

Moving to capture children’s attention: developing a methodology for measuring visuomotor attention

Attention underpins many activities integral to a child’s development. However, methodological limitations currently make large-scale assessment of children’s attentional skill impractical, costly and lacking in ecological validity. Consequently we developed a measure of ‘Visual Motor Attention’ (VMA) - a construct defined as the ability to sustain and adapt visuomotor behaviour in response to task-relevant visual information. In a series of experiments, we evaluated the capability of our method to measure attentional processes and their contributions in guiding visuomotor behaviour. Experiment 1 established the method’s core features (ability to track stimuli moving on a tablet-computer screen with a hand-held stylus) and demonstrated its sensitivity to principled manipulations in adults’ attentional load. Experiment 2 standardised a format suitable for use with children and showed construct validity by capturing developmental changes in executive attention processes. Experiment 3 tested the hypothesis that children with and without coordination difficulties would show qualitatively different response patterns, finding an interaction between the cognitive and motor factors underpinning responses. Experiment 4 identified associations between VMA performance and existing standardised attention assessments and thereby confirmed convergent validity. These results establish a novel approach to measuring childhood attention that can produce meaningful functional assessments that capture how attention operates in an ecologically valid context (i.e. attention's specific contribution to visuomanual action)

Space-time CFTs from the Riemann sphere

SCOAP

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The immunoprevention measures (vaccination by schedule plus mass campaigns) to achieve the objectives subscribed by PAHO/WHO produced around the year 2000 a sharp drop in cases of rubella and measles in Argentina. For this reason, there is currently a young population that only has immunity through the vaccine. Objective: Given the latent risk of reintroduction of these viruses in the country, we set out to investigate the presence of anti-rubella and anti-measles IgG antibodies in people aged 7 to 19 years who, according to the National Immunization Calendar and data from the National Surveillance Program, they should have two doses of triple viral vaccine and should not have had contact with the virus naturally. A retrospective, descriptive cross-sectional study was conducted. 180 samples from people between 7 and 19 years of age who attended the Fundación para el Progreso de la Medicina de Córdoba (FPM) for routine biochemical analyzes between the months of September 2021 and February 2022 were processed. rubella was determined by CMIA (ABBOTT) (FPM) while indirect immunofluorescence was performed for measles IgG at the Reina Fabiola University Clinic. The seroprevalences found were 88.3% and 92.2% for measles and rubella, respectively. There were no significant differences between antibody concentrations by age subgroup (rubella p=0.1435, measles p=0.1049), but the antibody concentration among women was significantly higher than among men (rubella p=0.036, measles p=0.031). Among women, anti-rubella IgG was higher in the younger age subgroup (p=0.0196), but not for measles (p=0.1874) nor among age subgroups of men (rubella p=0.7445, measles p=0.1236). The seroprevalences detected reach the coverage objective recommended by the WHO to prevent the circulation of rubella, but not the measles virus. These results show the need to sustain efforts to keep the prevalence of antibodies generated by vaccination high, also knowing that during the pandemic their application decreased, increasing the risk of virus reintroduction into the country.Las medidas de inmunoprevención (vacunación por calendario más campañas masivas) para lograr los objetivos suscriptos de la OPS/OMS produjeron hacia el año 2000 una caída abrupta de casos de rubéola y sarampión en Argentina. Por este motivo, actualmente existe una población joven que sólo tiene inmunidad a través de la vacuna. Objetivo: ante el riesgo latente de reintroducción de estos virus en el país, nos propusimos investigar la presencia de anticuerpos IgG anti-rubéola y antisarampión en personas de 7 a 19 años de edad que, de acuerdo al Calendario Nacional de Inmunizaciones y los datos del Programa Nacional de Vigilancia, deberían tener dos dosis de vacuna triple viral y no deberían haber tenido contacto con el virus de manera natural. Se realizó un estudio retrospectivo, descriptivo transversal. Se procesaron 180 muestras de personas de entre 7 y 19 años de edad que concurrieron a realizarse análisis bioquímicos de rutina a la Fundación para el Progreso de la Medicina de Córdoba (FPM) entre los meses de septiembre de 2021 y febrero de 2022. La IgG rubéola se determinó por CMIA (ABBOTT) (FPM) mientras que para IgG sarampión se realizó inmunofluorescencia indirecta en la Clínica Universitaria Reina Fabiola. Las seroprevalencias encontradas fueron del 88.3% y 92.2% para sarampión y rubéola respectivamente. No hubo diferencias significativas entre concentraciones de anticuerpos por subgrupo etario (rubéola p=0.1435, sarampión p=0.1049), pero la concentración de anticuerpos entre mujeres fue significativamente mayor que entre hombres (rubéola p=0.036, sarampión p=0.031). Entre mujeres la IgG anti-rubéola fue mayor en el subgrupo etario de menor edad (p=0.0196), no así para sarampión (p=0.1874) ni entre subgrupos etarios de hombres (rubéola p=0.7445, sarampión p=0.1236). Las seroprevalencias detectadas alcanzan el objetivo de cobertura recomendado por la OMS para impedir la circulación de rubéola, no así de virus sarampión. Estos resultados evidencian la necesidad de sostener los esfuerzos para mantener elevadas las prevalencias de anticuerpos generados por la vacunación, sabiendo además que durante la pandemia bajó la aplicación de las mismas, aumentando el riesgo de reintroducción de los virus en el país.

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Abstract:  Human Bocavirus-1/HBoV1 causes acute respiratory infections/ARI (bronchiolitis/pneumonia) mostly in young children. It was identified in 2005 and has not yet been incorporated into the routine virus screening in ARI. Symptoms of viral pneumonia in children less than 2 years old are often interpreted as of bacterial etiology, leading to unnecessary administration of antibiotics. Objective: to report the case of a previously healthy infant who developed HBoV1 pneumonia without complications, in order to consider HBoV1 as one of the possible agents involved. Clinical case. 19-month-old female, full-term/2780 grams. No relevant personal or familiar pathological history; complete vaccination. Reason for consultation: fever, cough, and shortness of breath. Antecedents: 3 days before, she started with rhinitis and dry cough. She had a fever peak of 38.7°C, so her pediatrician prescribed oral amoxicillin. On Apr/26/2021 she went to the emergency service due to persistent fever and worsening cough. Mild/moderate respiratory distress was observed; inhaled adrenergic drugs were administered, with good clinical response and outpatient follow-up (prior swabbing for COVID-19). The next day, she returned with food rejection and was hospitalized. Laboratory: hemoglobin 10.9g/dl, hematocrit 34%; leukocytes: 15,380 (69/15/15); platelets 299,000/ml; gases: 7.48/27.2/84.2/19.9/-2.1); ionogram Na 134/K 4/Cl 100; CRP: 17.8. Chest X-ray compatible with viral pneumonia. O2 saturation: 93%. Amoxicillin was suspended; hydration, oxygen by nasal cannula (3 liters/min) and inhaled salbutamol were administered. The complete panel of respiratory viruses was negative (RSV, Parainfluenza 1-3, Metapneumovirus, Influenza A/B and Adenovirus by IF; PCR for COVID-19: negative). HBoV1 detected in nasal secretions and serum (PCR with high viral load/>1x106 c.gen/mL) was the only positive finding. Evolution: 48 hours after admission she was afebrile; O2 saturation 95%; supplementary oxygen therapy was suspended. Patient was discharged without complications. In the follow-up (10 days) she did not show relapses or respiratory symptoms, so aerosol therapy was suspended. Conclusions. A case of HBoV1 infection in an infant with no comorbidity is reported. Recognition of the viral etiology in hospitalized cases of pneumonia contributes to optimize the clinical management of patients with rational use of antibiotics. HBoV1 should be included in the standard screening for respiratory infections in hospitalized infants.Resumen:  Bocavirus humano-1/HBoV1 es un parvovirus que causa infecciones respiratorias/IRA (bronquiolitis o neumonía) sobre todo en niños pequeños. Fue identificado en 2005 y aún no está incorporado a la pesquisa de virus habituales en IRA. Los cuadros de neumonía viral en menores de 2 años suelen interpretarse como de etiología bacteriana, administrándoles antibióticos innecesariamente. Objetivo: Reportar el caso de una lactante, sin comorbilidades previas, que desarrolla neumonía por HBoV1 sin complicaciones, a fin de considerar a este virus como uno más de los posibles agentes involucrados. Caso clínico. Paciente femenina de 19 meses de edad, nacida a término/2780gramos. Sin antecedentes patológicos, ni familiares relevantes; vacunación completa. MC: fiebre, tos y dificultad respiratoria. Antecedentes: 3 días previos inicia con rinitis y tos seca. Presenta un pico febril de 38,7°C por lo que su pediatra prescribió amoxicilina vía oral. El día 26/04/2021 concurre al servicio de emergencia por persistencia de la fiebre y empeoramiento de la tos. Se objetiva dificultad respiratoria leve/moderada; se administra adrenérgicos inhalados, con buena repuesta clínica y seguimiento ambulatorio (previo hisopado para COVID-19). Al día siguiente, ante el rechazo alimentario se decide internación. Laboratorio: Hemoglobina 10.9g/dl-Hto 34%; GB:15.380(69/15/15); plaquetas 299.000/ml; Gases:7.48/27.2/84.2/19.9/-2.1); Ionograma (Na134/K4/Cl100); PCR:17.8. Rx tórax compatible con neumonía viral. SatO2:93%. Se suspende amoxicilina, se administra hidratación, oxígeno por naricera-3litros/min y salbutamol inhalado. El panel completo de virus respiratorios resultó negativo (IFI para VRS, Parainfluenza 1,2,3, Metapneumovirus, Infuenza A y B y Adenovirus; PCR para COVID-19: negativo). Detección de HBoV1 en secreciones nasales y suero (PCR positiva con alta carga viral/>1x10^6c.gen/mL) fue el único hallazgo positivo. Evolución: a las 48 hs. del ingreso estaba afebril; Sat 95%; se suspende oxigenoterapia. Alta sin complicaciones. El seguimiento (hasta 10 días) no mostró recaídas o sintomatología respiratoria por lo que se suspende aerosolterapia. Conclusiones. Se reporta un caso de infección por BoVH1 en lactante sin comorbilidad previa. El reconocimiento de la etiología viral en los cuadros hospitalizados por neumonía contribuye a optimizar el manejo clínico de estos pacientes con uso más racional de antibióticos. La detección de BoVH1 debería ser parte de la pesquisa estándar para infecciones respiratorias en lactantes hospitalizados

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Parvovirus B19/B19V primary infection in pregnant women can be transmitted to the embryo/fetus and cause anomalies associated with TORCH syndrome. Local knowledge of the infection can help visualize the clinical picture to achieve early diagnosis. The objectives were to identify B19V in suspected cases of parvoviral infection during pregnancy and to describe the clinical manifestations present in positive cases. Descriptive, cross-sectional study. Inclusion criteria: pregnant patients with suspected B19V infection (compatible maternal or fetal-neonatal clinical manifestations or with epidemiological link), newborns (NB) of mothers with suspected or confirmed infection and NB with signs/symptoms associated with congenital infection (still present or not at birth), selected according to medical records of the clinical history. Viral DNA (PCR), specific IgM and IgG (ELISA) were determined in serum samples stored at the institution’s biobank. Ethical Committee of participating centers approved the protocol: Clinica Universitaria Reina Fabiola, Hospital Universitario de Maternidad y Neonatología, Clínica Privada Vélez Sársfield (2018-2022). A total of 242 patients were included (epidemiological weeks/EW 1-52, 171 pregnant women and 71 NB, 60 of them were mother-NB pair). Infection was confirmed in 27/242 (11.1%) cases, the majority (24/27, 88.9%) in pregnant women and 3/27 (11.1%) in NB. In the mother-NB pair group, 9 pregnant women and 2 NB were positive (vertical transmission rate: 22.2%). Epidemiological characteristics of B19V+ cases: mean age of pregnant women 30.1±6.3 years (p=0.45 versus study sample; median 30.5), 96% in EW 15-52 (autumn-spring). Clinical manifestations in pregnant women: maternal anemia 14/24 (58.3%), hydrops fetalis 5/24 (20.8%), abortion 5/24 (20.8%), fetal anemia 2/24 (8.3%), polyhydramnios 1/24 (4.2%), rash and arthralgia 1/24 (4.2%). One NB presented hydrops, another anemia, and one was asymptomatic, born to mother with rash, arthralgia, and anemia). Laboratory markers of infection: 16/27 (59.3%) cases were confirmed by detection of viral DNA (DNA+/IgM-/IgG+). During the study period, B19V was detected in 11% of the sample, being frequent in symptomatic pregnant women (24/171, 14%), with a rate of transmission to the fetus of 22%. Upon clinical suspicion, the complementary determination of virus and antibodies can improve diagnostic performance.La primoinfección por parvovirus B19/B19V en la embarazada puede transmitirse al embrión/feto y causar manifestaciones clínicas asociadas al síndrome de TORCH. Conocer la infección en nuestro medio puede contribuir a visibilizar su presentación clínica y promover el diagnóstico temprano. Los objetivos fueron identificar B19V en casos sospechosos de infección parvoviral durante la gestación y describir las manifestaciones clínicas presentes en los casos positivos. Estudio descriptivo, transversal. Se incluyeron pacientes embarazadas con sospecha de infección por B19V (manifestaciones clínicas maternas o feto-neonatales compatibles o nexo epidemiológico), RN de madres con infección sospechada o confirmada y RN con signos/síntomas asociables a infección congénita (aún presentes o no al nacer), seleccionados a partir de los datos de la historia clínica. Se determinó ADN viral (PCR), IgM e IgG específicas (ELISA) en muestras de suero recuperadas del biobanco. Protocolo aprobado por los Comités de Ética de los centros participantes: Clínica Universitaria Reina Fabiola, Hospital Universitario de Maternidad y Neonatología, Clínica Privada Vélez Sársfield (2018-2022). Se estudiaron 242 pacientes (semanas epidemiológicas/SE 1-52, 171 embarazadas y 71 RN, de ellos 60 constituían binomio madre-RN), confirmándose la infección en 27/242 (11,1%), la mayoría (24/27, 88,9%) en embarazadas y 3/27 (11,1%) en RN. En el grupo de binomios, fueron positivos 9 embarazadas y 2 RN (tasa de transmisión vertical: 22,2%). Características epidemiológicas de los casos B19V+: edad promedio de las embarazadas 30,1±6,3 años (p=0,45 versus muestra estudiada; mediana 30,5), 96% en las SE 15-52 (otoño-primavera). Manifestaciones marcadoras en embarazadas: anemia materna 14/24 (58,3%), hydrops fetal 5/24 (20,8%), aborto 5/24 (20,8%), anemia fetal 2/24 (8,3%), polihidramnios 1/24 (4,2%), exantema y artralgia 1/24 (4,2%). Un RN presentó hydrops, otro anemia y otro fue asintomático (con antecedente de madre positiva con exantema, artralgia y anemia en la madre). Marcadores laboratoriales de infección: 16/27 (59,3%) casos fueron confirmados por detección de ADN viral (ADN+/IgM-/IgG+). En el período estudiado se detectó B19V en 11% de la muestra, siendo frecuente en embarazadas sintomáticas (24/171, 14%), con una tasa de transmisión al feto de 22%. Ante la sospecha clínica, la determinación complementaria de virus y anticuerpos puede mejorar el rendimiento diagnóstico.

Ambitwistor strings and the scattering equations at one loop

Ambitwistor strings are chiral, infinite tension analogues of conventional string theory whose target space is the space of complex null geodesics and whose spectrum consists exclusively of massless states. At genus zero, these strings underpin the Cachazo-He-Yuan formulae for tree level scattering of gravitons, gluons and scalars. In this paper we extend these formulae in a number of directions. Firstly, we consider Ramond sector vertex operators and construct simple amplitudes involving space-time fermions. These agree with tree amplitudes in ten dimensional supergravity and super Yang--Mills. We then show that, after the usual GSO projections, the ambitwistor string partition function is modular invariant. We consider the scattering equations at genus one, and calculate one loop scattering amplitudes for NS-NS external states in the Type II ambitwistor string. We conjecture that these give new representations of (the integrand of) one loop supergravity amplitudes and we show that they have the expected behaviour under factorization of the worldsheet in both non--separating and separating degenerations.Comment: 34 pages, no figures. v2: improvements to discussion, references update