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1.
Phys Rev Lett ; 127(15): 151803, 2021 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-34678031

RESUMEN

We present a search for the decays of a neutral scalar boson produced by kaons decaying at rest, in the context of the Higgs portal model, using the MicroBooNE detector. We analyze data triggered in time with the Fermilab NuMI neutrino beam spill, with an exposure of 1.93×10^{20} protons on target. We look for monoenergetic scalars that come from the direction of the NuMI hadron absorber, at a distance of 100 m from the detector, and decay to electron-positron pairs. We observe one candidate event, with a standard model background prediction of 1.9±0.8. We set an upper limit on the scalar-Higgs mixing angle of θ<(3.3-4.6)×10^{-4} at the 95% confidence level for scalar boson masses in the range (100-200) MeV/c^{2}. We exclude, at the 95% confidence level, the remaining model parameters required to explain the central value of a possible excess of K_{L}^{0}→π^{0}νν[over ¯] decays reported by the KOTO collaboration. We also provide a model-independent limit on a new boson X produced in K→πX decays and decaying to e^{+}e^{-}.

2.
J Plast Reconstr Aesthet Surg ; 74(5): 1101-1160, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33483263

RESUMEN

The Covid-19 pandemic has forced us to treat mammalian bite injuries more conservatively as resources were redirected to the Covid effort resulting in limited availability of hospital beds and theatre space. When comparing our outcomes before and during the first Covid-19 lockdown, this more conservative approach, which resulted in 24% less admissions and 19% less washouts in theatre, did not result in an increased infection rate. An increased rate of bite injuries during the national lockdown period was also noted. We support the conclusion by Chicco et al. that the majority of patients with bite injuries can 'safely be managed with washout under local anaesthesia, oral antibiotics and discharge on the same day with safety net advice'. It is interesting that in some aspects of our care we may find Covid-19 has been beneficial in de-medicalising management of certain injuries and conditions.


Asunto(s)
COVID-19 , Animales , Control de Enfermedades Transmisibles , Comunicación , Humanos , Pandemias , SARS-CoV-2
3.
S Afr Med J ; 110(10): 988-992, 2020 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-33205725

RESUMEN

Breast cancer is highly prevalent in South Africa, and up to 10% of breast cancer cases may be hereditary. The landscape of genetic testing options for hereditary breast cancer (HBC) has changed significantly over the past decade, and healthcare providers are faced with multiple options when referring breast cancer patients for genetic testing. We have performed a retrospective study of 3 years' worth of breast cancer genetic testing referrals to our laboratory. While Afrikaner and Ashkenazi Jewish founder screens may be appropriate as first-line tests in a limited subset of patients, we have shown that in the majority of cases it is more effective to adopt a multigene panel approach. While variants in the BRCA1 and BRCA2 genes still account for a significant proportion of cases, close to 40% of pathogenic variants were found in genes other than BRCA1 or BRCA2. There are many factors that healthcare providers should consider when requesting genetic testing for breast cancer patients and families, including family history, ancestral background, cost, medical aid scheme reimbursement and scope of testing. We summarise our findings and provide advantages and disadvantages of each approach, with the aim of assisting clinicians and genetic counsellors to make appropriate testing decisions.


Asunto(s)
Neoplasias de la Mama/diagnóstico , Pruebas Genéticas , Proteína BRCA2/genética , Neoplasias de la Mama/genética , Efecto Fundador , Humanos , Herencia Multifactorial , Estudios Retrospectivos , Sudáfrica , Ubiquitina-Proteína Ligasas/genética
4.
Phys Rev Lett ; 123(4): 042502, 2019 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-31491269

RESUMEN

We report the first measurement of the neutron cross section on argon in the energy range of 100-800 MeV. The measurement was obtained with a 4.3-h exposure of the Mini-CAPTAIN detector to the WNR/LANSCE beam at LANL. The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume. A set of 2631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms specifically designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector. The energy averaged cross section is 0.91±0.10(stat)±0.09(syst) b. A comparison of the measured cross section is made to the GEANT4 and FLUKA event generator packages, where the energy averaged cross sections in this range are 0.60 and 0.68 b, respectively.

6.
BMC Plant Biol ; 19(1): 172, 2019 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-31039740

RESUMEN

BACKGROUND: Angiosperm sex chromosomes, where present, are generally recently evolved. The key step in initiating the development of sex chromosomes from autosomes is the establishment of a sex-determining locus within a region of non-recombination. To better understand early sex chromosome evolution, it is important to determine the process by which recombination is suppressed around the sex determining genes. We have used the dioecious angiosperm kiwifruit Actinidia chinensis var. chinensis, which has an active-Y sex chromosome system, to study recombination rates around the sex locus, to better understand key events in the development of sex chromosomes. RESULTS: We have confirmed the sex-determining region (SDR) in A. chinensis var. chinensis, using a combination of high density genetic mapping and fluorescent in situ hybridisation (FISH) of Bacterial Artificial Chromosomes (BACs) linked to the sex markers onto pachytene chromosomes. The SDR is a subtelomeric non-recombining region adjacent to the nucleolar organiser region (NOR). A region of restricted recombination of around 6 Mbp in size in both male and female maps spans the SDR and covers around a third of chromosome 25. CONCLUSIONS: As recombination is suppressed over a similar region between X chromosomes and between and X and Y chromosomes, we propose that recombination is suppressed in this region because of the proximity of the NOR and the centromere, with both the NOR and centromere suppressing recombination, and this predates suppressed recombination due to differences between X and Y chromosomes. Such regions of suppressed recombination in the genome provide an opportunity for the evolution of sex chromosomes, if a sex-determining locus develops there or translocates into this region.


Asunto(s)
Actinidia/genética , Cromosomas de las Plantas , Recombinación Genética , Cromosomas Sexuales , Actinidia/citología , Mapeo Cromosómico , Cromosomas Artificiales Bacterianos , Variación Genética , Hibridación Fluorescente in Situ , Repeticiones de Microsatélite
7.
Eur J Neurol ; 26(5): 780-785, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30576046

RESUMEN

BACKGROUND AND PURPOSE: Symptoms and signs in patients with Huntington's disease are usually assessed with the Unified Huntington's Disease Rating Scale (UHDRS). Ceiling and floor effects hamper the measurement of disease progression in patients with late stage Huntington's disease and therefore the UHDRS-For Advanced Patients (UHDRS-FAP) has been developed. The aim of this longitudinal study was to examine if the UHDRS-FAP and UHDRS are sensitive enough to detect change over time in late stage Huntington's disease. METHODS: Forty nursing home residents and patients receiving day-care were assessed with the UHDRS, UHDRS-FAP and Care Dependency Scale (CDS). After 6 months, the assessment scales were completed again in 29 patients. Changes between baseline and follow-up were calculated using paired t tests. Wilcoxon signed-rank tests were used to calculate longitudinal changes for middle and late stage patients separately. RESULTS: The motor and cognitive score of the UHDRS-FAP deteriorated during 6 months' follow-up, whilst the motor and cognitive score of the UHDRS did not show change. Two functional domains of the UHDRS and the CDS also declined. The behavioral score significantly improved with both rating scales in late stage patients. CONCLUSIONS: Our results suggest that the UHDRS-FAP motor and cognitive score, the functional domains of the UHDRS, and the CDS can detect disease progression in late stage Huntington's disease. Therefore, the use of these scores in nursing homes is recommended to optimize care by monitoring disease progression and by evaluating the effect of interventions in clinical care. Psychiatric symptoms seem to fade away as the disease progresses.


Asunto(s)
Enfermedad de Huntington/diagnóstico , Adulto , Anciano , Conducta , Cognición , Progresión de la Enfermedad , Femenino , Humanos , Enfermedad de Huntington/psicología , Estudios Longitudinales , Masculino , Trastornos Mentales/etiología , Trastornos Mentales/psicología , Persona de Mediana Edad , Pruebas Neuropsicológicas , Valor Predictivo de las Pruebas , Desempeño Psicomotor , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
8.
Phys Rev Lett ; 120(16): 163903, 2018 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-29756941

RESUMEN

In this Letter, we show that it is possible to structure the longitudinal polarization component of light. We illustrate our approach by demonstrating linked and knotted longitudinal vortex lines acquired upon nonparaxially propagating a tightly focused subwavelength beam. The remaining degrees of freedom in the transverse polarization components can be exploited to generate customized topological vector beams.

9.
Phys Rev Lett ; 120(6): 063201, 2018 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-29481231

RESUMEN

We propose a method of atom interferometry using a spinor Bose-Einstein condensate with a time-varying magnetic field acting as a coherent beam splitter. Our protocol creates long-lived superpositional counterflow states, which are of fundamental interest and can be made sensitive to both the Sagnac effect and magnetic fields on the sub-µG scale. We split a ring-trapped condensate, initially in the m_{f}=0 hyperfine state, into superpositions of internal m_{f}=±1 states and condensate superflow, which are spin-orbit coupled. After interrogation, the relative phase accumulation can be inferred from a population transfer to the m_{f}=±1 states. The counterflow generation protocol is adiabatically deterministic and does not rely on coupling to additional optical fields or mechanical stirring techniques. Our protocol can maximize the classical Fisher information for any rotation, magnetic field, or interrogation time and so has the maximum sensitivity available to uncorrelated particles. Precision can increase with the interrogation time and so is limited only by the lifetime of the condensate.

10.
Transl Psychiatry ; 7(6): e1143, 2017 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-28585930

RESUMEN

Depression is one of the most prevalent and debilitating psychiatric disorders worldwide. Recently, we showed that both relatively short and relatively long cytosine-adenine-guanine (CAG) repeats in the huntingtin gene (HTT) are associated with an increased risk of lifetime depression. However, to what extent the variations in CAG repeat length in the other eight polyglutamine disease-associated genes (PDAGs) are associated with depression is still unknown. We determined the CAG repeat sizes of ATXN1, ATXN2, ATXN3, CACNA1A, ATXN7, TBP, ATN1 and AR in two well-characterized Dutch cohorts-the Netherlands Study of Depression and Anxiety and the Netherlands Study of Depression in Older Persons-including 2165 depressed and 1058 non-depressed individuals-aged 18-93 years. The association between PDAG CAG repeat size and the risk for depression was assessed via binary logistic regression. We found that the odds ratio (OR) for lifetime depression was significantly higher for individuals with >10, compared with subjects with ≤10, CAG repeats in both ATXN7 alleles (OR=1.90, confidence interval (CI) 1.26-2.85). For TBP we found a similar association: A CAG repeat length exceeding the median in both alleles was associated with an increased risk for lifetime depression (OR=1.33, CI 1.00-1.76). In conclusion, we observed that carriers of either ATXN7 or TBP alleles with relatively large CAG repeat sizes in both alleles had a substantially increased risk of lifetime depression. Our findings provide critical evidence for the notion that repeat polymorphisms can act as complex genetic modifiers of depression.


Asunto(s)
Ataxina-7/genética , Predisposición Genética a la Enfermedad , Proteína de Unión a TATA-Box/genética , Repeticiones de Trinucleótidos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Ataxinas/genética , Canales de Calcio/genética , Estudios de Casos y Controles , Trastorno Depresivo/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas del Tejido Nervioso/genética , Polimorfismo Genético , Receptores Androgénicos/genética , Adulto Joven
11.
J R Coll Physicians Edinb ; 46(3): 198-205, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27959357

RESUMEN

While medical historians have paid ample attention to the introduction of antibiotics and their impact on hospital-based practice during and after the Second World War, the multiple issues surrounding their use in Scottish hospitalsare sorely lacking in current discussions. Drawing on an extensive yet underused range of materials including patient treatment records, oral histories and medical correspondence, this paper explores the introduction of penicillin for civilian treatment at the Royal Infirmary of Edinburgh during the closing stages of the War. It highlights the success of the drug in clinical treatment as well as its shortcomings, offering an alternative view of its initial impact on surgical practice.


Asunto(s)
Antibacterianos/historia , Farmacorresistencia Microbiana , Hospitales/historia , Control de Infecciones/historia , Penicilinas/historia , Guerra , Segunda Guerra Mundial , Antibacterianos/provisión & distribución , Antibacterianos/uso terapéutico , Cirugía General/historia , Historia del Siglo XX , Humanos , Control de Infecciones/métodos , Penicilinas/provisión & distribución , Penicilinas/uso terapéutico , Escocia
13.
Phys Rev Lett ; 114(13): 134101, 2015 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-25884125

RESUMEN

We use an effective one-dimensional Gross-Pitaevskii equation to study bright matter-wave solitons held in a tightly confining toroidal trapping potential, in a rotating frame of reference, as they are split and recombined on narrow barrier potentials. In particular, we present an analytical and numerical analysis of the phase evolution of the solitons and delimit a velocity regime in which soliton Sagnac interferometry is possible, taking account of the effect of quantum uncertainty.

14.
Nat Commun ; 4: 1865, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23673650

RESUMEN

Bright solitons are non-dispersive wave solutions, arising in a diverse range of nonlinear, one-dimensional systems, including atomic Bose-Einstein condensates with attractive interactions. In reality, cold-atom experiments can only approach the idealized one-dimensional limit necessary for the realization of true solitons. Nevertheless, it remains possible to create bright solitary waves, the three-dimensional analogue of solitons, which maintain many of the key properties of their one-dimensional counterparts. Such solitary waves offer many potential applications and provide a rich testing ground for theoretical treatments of many-body quantum systems. Here we report the controlled formation of a bright solitary matter-wave from a Bose-Einstein condensate of (85)Rb, which is observed to propagate over a distance of ∼1.1 mm in 150 ms with no observable dispersion. We demonstrate the reflection of a solitary wave from a repulsive Gaussian barrier and contrast this to the case of a repulsive condensate, in both cases finding excellent agreement with theoretical simulations using the three-dimensional Gross-Pitaevskii equation.

15.
Theor Appl Genet ; 126(3): 847-65, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23224381

RESUMEN

Fruit from Rubus species are highly valued for their flavor and nutritive qualities. Anthocyanin content contributes to these qualities, and although many studies have been conducted to identify and quantify the major anthocyanin compounds from various Rubus species, the genetic control of the accumulation of these complex traits in Rubus is not yet well understood. The identification of the regions of the genome involved in the production of anthocyanins is an important first step in identifying the genes underlying their expression. In this study, ultra and high-performance liquid chromatography (UHPLC and HPLC) and two newly developed Rubus linkage maps were used to conduct QTL analyses to explore the presence of associations between concentrations of five anthocyanins in fruit and genotype. In total, 27 QTL were identified on the Rubus linkage maps, four of which are associated with molecular markers designed from transcription factors and three of which are associated with molecular markers designed from anthocyanin biosynthetic pathway candidate genes. The results of this study suggest that, while QTL for anthocyanin accumulation have been identified on six of seven Rubus linkage groups (RLG), the QTL on RLG2 and RLG7 may be very important for genetic control of cyanidin modification in Rubus.


Asunto(s)
Antocianinas/análisis , Frutas/genética , Genes de Plantas , Sitios de Carácter Cuantitativo , Rosaceae/genética , Cromatografía Líquida de Alta Presión , Mapeo Cromosómico , Epistasis Genética , Frutas/química , Ligamiento Genético , Marcadores Genéticos , Fenotipo , Rosaceae/química , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
16.
Theor Appl Genet ; 125(2): 311-27, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22398438

RESUMEN

The genus Rubus belongs to the Rosaceae and is comprised of 600-800 species distributed world-wide. To date, genetic maps of the genus consist largely of non-transferable markers such as amplified fragment length polymorphisms. An F(1) population developed from a cross between an advanced breeding selection of Rubus occidentalis (96395S1) and R. idaeus 'Latham' was used to construct a new genetic map consisting of DNA sequence-based markers. The genetic linkage maps presented here are constructed of 131 markers on at least one of the two parental maps. The majority of the markers are orthologous, including 14 Rosaceae conserved orthologous set markers, and 60 new gene-based markers developed for raspberry. Thirty-four published raspberry simple sequence repeat markers were used to align the new maps to published raspberry maps. The 96395S1 genetic map consists of six linkage groups (LG) and covers 309 cM with an average of 10 cM between markers; the 'Latham' genetic map consists of seven LG and covers 561 cM with an average of 5 cM between markers. We used BLAST analysis to align the orthologous sequences used to design primer pairs for Rubus genetic mapping with the genome sequences of Fragaria vesca 'Hawaii 4', Malus × domestica 'Golden Delicious', and Prunus 'Lovell'. The alignment of the orthologous markers designed here suggests that the genomes of Rubus and Fragaria have a high degree of synteny and that synteny decreases with phylogenetic distance. Our results give unprecedented insights into the genome evolution of raspberry from the putative ancestral genome of the single ancestor common to Rosaceae.


Asunto(s)
Mapeo Cromosómico/métodos , Fragaria/genética , Ligamiento Genético , Genoma de Planta/genética , Malus/genética , Prunus/genética , Rosaceae/genética , Cromosomas de las Plantas/genética , Cruzamientos Genéticos , Marcadores Genéticos , Filogenia
18.
Br J Pharmacol ; 161(1): 92-102, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20718742

RESUMEN

BACKGROUND AND PURPOSE: The incretin hormone, glucagon-like peptide (GLP)-1(7-36), is rapidly cleaved by dipeptidyl peptidase 4 (DPP-4) into GLP-1(9-36), and although it is agreed that most, if not all, of the metabolic effects are attributable to the intact peptide, the degree to which the cardiovascular effects are due to the cleavage product is unclear. The purpose of this study was to measure the regional haemodynamic effects of GLP-1(7-36), and determine the extent to which the cardiovascular effects of GLP-1(7-36) were influenced by DPP-4 inhibition and reproduced by GLP-1(9-36). Additional experiments investigated the involvement of autonomic mechanisms in the cardiovascular effects of GLP-1(7-36). EXPERIMENTAL APPROACH: Regional haemodynamic effects of bolus doses and 4 h infusions of GLP-1(7-36) amide and GLP-1(9-36) amide were measured in conscious, chronically instrumented rats; the influence of DPP-4 inhibition and autonomic blockade on responses to GLP-1(7-36) were also assessed. KEY RESULTS: Glucagon-like peptide-1(7-36) had clear regional haemodynamic effects comprising tachycardia, a rise in blood pressure, renal and mesenteric vasoconstriction and hindquarters vasodilatation, whereas GLP-1(9-36) was devoid of any cardiovascular actions. The effects of GLP-1(7-36) were enhanced by DPP-4 inhibition, and the tachycardia and hindquarters vasodilatation were beta-adrenoceptor-mediated. CONCLUSIONS AND IMPLICATIONS: In conscious rats, the cardiovascular effects of GLP-1(7-36) resemble those of the GLP analogue, exendin-4, and are attributable to the intact peptide rather than the cleavage product, GLP-1(9-36).


Asunto(s)
Presión Sanguínea/efectos de los fármacos , Péptido 1 Similar al Glucagón/análogos & derivados , Fragmentos de Péptidos/farmacología , Péptidos/farmacología , Taquicardia/inducido químicamente , Vasoconstricción/efectos de los fármacos , Vasodilatación/efectos de los fármacos , Animales , Fármacos Cardiovasculares/administración & dosificación , Fármacos Cardiovasculares/farmacología , Dipeptidil Peptidasa 4/metabolismo , Inhibidores de la Dipeptidil-Peptidasa IV/farmacología , Péptido 1 Similar al Glucagón/administración & dosificación , Péptido 1 Similar al Glucagón/farmacología , Masculino , Fragmentos de Péptidos/administración & dosificación , Péptidos/administración & dosificación , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
19.
Phys Rev Lett ; 103(8): 083201, 2009 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-19792725

RESUMEN

For two states of opposite parity that cross as a function of an external magnetic field, the addition of an electric field will break the symmetry and induce an avoided crossing. A suitable arrangement of fields may be used to create a conical intersection as a function of external spatial coordinates. We consider the effect of the resulting geometric phase for ultracold polar molecules. For a Bose-Einstein condensate in the mean-field approximation, the geometric phase effect induces stable states of persistent superfluid flow that are characterized by half-integer quantized angular momentum.

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