Quantum Skyrmion Lattices in Heisenberg Ferromagnets

Skyrmions are topological magnetic textures which can arise in non-centrosymmetric ferromagnetic materials. In most systems experimentally investigated to date, skyrmions emerge as classical objects. However, the discovery of skyrmions with nanometer length scales has sparked interest in their quantum properties. Quantum corrections to the classical magnetic textures have already been considered in the semiclassical regime. Here, we go beyond this limit by investigating quantum skyrmions in the deep quantum regime. We use density matrix renormalization group techniques to study two-dimensional spin-1/2 Heisenberg ferromagnets with Dzyaloshinskii-Moriya interactions and discover a broad region in the zero temperature phase diagram which hosts quantum skyrmion lattice ground states. We argue that this novel quantum skyrmion phase can be detected experimentally in the magnetization profile via local magnetic polarization measurements as well as in the spin structure factor measurable via neutron scattering experiments. Finally, we explore the resulting quantum skyrmion state, analyze its real space polarization profile and show that it is a non-classical state featuring entanglement between quasiparticle and environment mainly localized near the boundary spins of the skyrmion

Beta Samati: discovery and excavation of an Aksumite town

The Empire of Aksum was one of Africa's most influential ancient civilisations. Traditionally, most archaeological fieldwork has focused on the capital city of Aksum, but recent research at the site of Beta Samati has investigated a contemporaneous trade and religious centre located between Aksum and the Red Sea. The authors outline the discovery of the site and present important finds from the initial excavations, including an early basilica, inscriptions and a gold intaglio ring. From daily life and ritual praxis to international trade, this work illuminates the role of Beta Samati as an administrative centre and its significance within the wider Aksumite world

GESTÃO DE CUSTOS NA ATIVIDADE LEITEIRA: SISTEMA TRADICIONAL E COMPOST BARN

O estudo apresenta as diferenças de custos em dois sistemas de produção leiteira, tradicional e compost barn. Os casos são propriedades localizadas no interior de São Miguel do Oeste SC, com dados de 07/2020 a 06/2021. Os custos relacionados à produção leiteira no geral, apresentaram-se superiores no compost barn durante o período analisado. O custo unitário no segundo semestre de 2020, no sistema compost barn foi de R 1,32, já no sistema tradicional o custo por litro foi  R 1,22, enquanto no primeiro semestre de 2021 o custo por litro no compost barn ficou em R$1,88 e no tradicional R$ 1,70. O custo maior no compost barn é compensado pela produção de leite. No segundo semestre de 2020 o método compost barn apresentou uma margem de lucro maior R$0,82 e R$ 0,66 no tradicional, o alto custo da alimentação, responsavel pela maior parcela dos custos totais, fez com que no primeiro semestre de 2021 a situação fosse inversa, no sistema compost barn o lucro por litro foi de R$0,24 e no tradicional R$ 0,30 mostrando-se superior. Desse modo, conclui-se que o compost barn, apesar de possuir custos superiores de produção em relação ao sistema tradicional, apresenta maior lucratividade. Palavras-chaves: Atividade leiteira. Gestão de custos. Sistema tradicional. Compost barn. &nbsp

Application of Intravitreal Bevacizumab for Circumscribed Choroidal Hemangioma

We report 3 cases of circumscribed choroidal hemangioma (CCH) effectively managed with intravitreal bevacizumab. One patient (case 1) who had recurrent CCH (1.6 mm in thickness) with prior laser photocoagulation was treated with intravitreal bevacizumab alone. Two patients (case 2 and 3) who had CCH (2.4 mm and 2.2 mm in thickness, respectively) with recent visual impairment were treated with bevacizumab followed by photodynamic therapy (PDT). Ophthalmic evaluations included visual acuity, ophthalmoscopic examination, fluorescein angiography, ultrasonography, and optical coherence tomography. Patients were followed up for 6-9 months. After therapy, all patients showed improved visual acuity due to complete resorption of subretinal fluid and macular edema. Ultrasonography demonstrated a reduction of the thickness of CCH in case 1 and complete regression of the lesions in case 2 and 3. No patient showed tumor recurrence. Intravitreal bevacizumab, alone or in combination therapy with PDT, may be a useful alternative for the treatment of symptomatic CCH with subretinal fluid

Unraveling Nanostructured Spin Textures in Bulk Magnets

One of the key challenges in magnetism remains the determination of the nanoscopic magnetization profile within the volume of thick samples, such as permanent ferromagnets. Thanks to the large penetration depth of neutrons, magnetic small-angle neutron scattering (SANS) is a powerful technique to characterize bulk samples. The major challenge regarding magnetic SANS is accessing the real-space magnetization vector field from the reciprocal scattering data. In this letter, a fast iterative algorithm is introduced that allows one to extract the underlying two-dimensional magnetic correlation functions from the scattering patterns. This approach is used here to analyze the magnetic microstructure of Nanoperm, a nanocrystalline alloy which is widely used in power electronics due to its extraordinary soft magnetic properties. It can be shown that the computed correlation functions clearly reflect the projection of the three-dimensional magnetization vector field onto the detector plane, which demonstrates that the used methodology can be applied to probe directly spin-textures within bulk samples with nanometer-resolution.Comment: 9 pages, 3 figure

Expanding the palette of phenanthridinium cations

5,6-Disubstituted phenanthridinium cations have a range of redox, fluorescence and biological properties. Some properties rely on phenanthridiniums intercalating into DNA, but the use of these cations as exomarkers for the reactive oxygen species (ROS), superoxide, and as inhibitors of acetylcholine esterase (AChE) do not require intercalation. A versatile modular synthesis of 5,6-disubstituted phenanthridiniums that introduces diversity by Suzuki–Miyaura coupling, imine formation and microwave-assisted cyclisation is presented. Computational modelling at the density functional theory (DFT) level reveals that the novel displacement of the aryl halide by an acyclic N-alkylimine proceeds by an SNAr mechanism rather than electrocyclisation. It is found that the displacement of halide is concerted and there is no stable Meisenheimer intermediate, provided the calculations consistently use a polarisable solvent model and a diffuse basis set

Improving quality of care and outcome at very preterm birth: the Preterm Birth research programme, including the Cord pilot RCT

BACKGROUND:Being born very premature (i.e. before 32 weeks’ gestation) has an impact on survival and quality of life. Improving care at birth may improve outcomes and parents’ experiences. OBJECTIVES:To improve the quality of care and outcomes following very preterm birth. DESIGN:We used mixed methods, including a James Lind Alliance prioritisation, a systematic review, a framework synthesis, a comparative review, qualitative studies, development of a questionnaire tool and a medical device (a neonatal resuscitation trolley), a survey of practice, a randomised trial and a protocol for a prospective meta-analysis using individual participant data. SETTING:For the prioritisation, this included people affected by preterm birth and health-care practitioners in the UK relevant to preterm birth. The qualitative work on preterm birth and the development of the questionnaire involved parents of infants born at three maternity hospitals in southern England. The medical device was developed at Liverpool Women’s Hospital. The survey of practice involved UK neonatal units. The randomised trial was conducted at eight UK tertiary maternity hospitals. PARTICIPANTS:For prioritisation, 26 organisations and 386 individuals; for the interviews and questionnaire tool, 32 mothers and seven fathers who had a baby born before 32 weeks’ gestation for interviews evaluating the trolley, 30 people who had experienced it being used at the birth of their baby (19 mothers, 10 partners and 1 grandmother) and 20 clinicians who were present when it was being used; for the trial, 261 women expected to have a live birth before 32 weeks’ gestation, and their 276 babies. INTERVENTIONS:Providing neonatal care at very preterm birth beside the mother, and with the umbilical cord intact; timing of cord clamping at very preterm birth. MAIN OUTCOME MEASURES:Research priorities for preterm birth; feasibility and acceptability of the trolley; feasibility of a randomised trial, death and intraventricular haemorrhage. REVIEW METHODS:Systematic review of Cochrane reviews (umbrella review); framework synthesis of ethics aspects of consent, with conceptual framework to inform selection criteria for empirical and analytical studies. The comparative review included studies using a questionnaire to assess satisfaction with care during childbirth, and provided psychometric information. RESULTS:Our prioritisation identified 104 research topics for preterm birth, with the top 30 ranked. An ethnographic analysis of decision-making during this process suggested ways that it might be improved. Qualitative interviews with parents about their experiences of very preterm birth identified two differences with term births: the importance of the staff appearing calm and of staff taking control. Following a comparative review, this led to the development of a questionnaire to assess parents’ views of care during very preterm birth. A systematic overview summarised evidence for delivery room neonatal care and revealed significant evidence gaps. The framework synthesis explored ethics issues in consent for trials involving sick or preterm infants, concluding that no existing process is ideal and identifying three important gaps. This led to the development of a two-stage consent pathway (oral assent followed by written consent), subsequently evaluated in our randomised trial. Our survey of practice for care at the time of birth showed variation in approaches to cord clamping, and that no hospitals were providing neonatal care with the cord intact. We showed that neonatal care could be provided beside the mother using either the mobile neonatal resuscitation trolley we developed or existing equipment. Qualitative interviews suggested that neonatal care beside the mother is valued by parents and acceptable to clinicians. Our pilot randomised trial compared cord clamping after 2 minutes and initial neonatal care, if needed, with the cord intact, with clamping within 20 seconds and initial neonatal care after clamping. This study demonstrated feasibility of a large UK randomised trial. Of 135 infants allocated to cord clamping ≥ 2 minutes, 7 (5.2%) died and, of 135 allocated to cord clamping ≤ 20 seconds, 15 (11.1%) died (risk difference –5.9%, 95% confidence interval –12.4% to 0.6%). Of live births, 43 out of 134 (32%) allocated to cord clamping ≥ 2 minutes had intraventricular haemorrhage compared with 47 out of 132 (36%) allocated to cord clamping ≤ 20 seconds (risk difference –3.5%, 95% CI –14.9% to 7.8%). LIMITATIONS:Small sample for the qualitative interviews about preterm birth, single-centre evaluation of neonatal care beside the mother, and a pilot trial. CONCLUSIONS:Our programme of research has improved understanding of parent experiences of very preterm birth, and informed clinical guidelines and the research agenda. Our two-stage consent pathway is recommended for intrapartum clinical research trials. Our pilot trial will contribute to the individual participant data meta-analysis, results of which will guide design of future trials. FUTURE WORK:Research in preterm birth should take account of the top priorities. Further evaluation of neonatal care beside the mother is merited, and future trial of alternative policies for management of cord clamping should take account of the meta-analysis. STUDY REGISTRATION:This study is registered as PROSPERO CRD42012003038 and CRD42013004405. In addition, Current Controlled Trials ISRCTN21456601. FUNDING:This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 7, No. 8. See the NIHR Journals Library website for further project information

Magyar Gyógypedagógia 17 (1929) 09-10

A Magyar Gyógypedagógiai Társaság folyóirata 17. évfolyam, 9-10. szám, Budapest, 1929. Havi folyóirat a fogyatékosok (siketnémák, vakok, szellemileg gyengék, beszédhibások, idegesek, epileptikusok és nyomorékok) ügyeinek tárgyalására. 1939-től beolvadt a Magyar gyógypedagógiai tanárok közlönyébe