Start to end simulations of the ERL prototype at Daresbury Laboratory

Daresbury Laboratory is currently building an Energy Recovery Linac Prototype (ERLP) that will serve as a research and development facility for the study of beam dynamics and accelerator technology important to the design and construction of the proposed 4th Generation Light Source (4GLS) project. Two major objectives of the ERLP are the demonstration of energy recovery and of energy recovery from a beam disrupted by an FEL interaction as supplied by an infrared oscillator system. In this paper we present start-to-end simulations of the ERLP including such an FEL interaction. The beam dynamics in the highbrightness injector, which consists of a DC photocathode Gun and a superconducting booster, have been modelled using the particle tracking code ASTRA. After the booster the particles have been tracked with the code elegant. The 3D code GENESIS 1.3 was used to model the FEL interaction with the electron beam at 35 MeV. A brief summary of impedance and wakefield calculations for the whole machine is also given

Focusing on autism spectrum disorder in xia–gibbs syndrome: Description of a female with high functioning autism and literature review

Background: Xia–Gibbs syndrome (XGS) is a rare disorder caused by de novo mutations in the AT-Hook DNA binding motif Containing 1 (AHDC1) gene, which is characterised by a wide spectrum of clinical manifestations, including global developmental delay, intellectual disability, structural abnormalities of the brain, global hypotonia, feeding problems, sleep difficulties and apnoea, facial dysmorphisms, and short stature. Methods: Here, we report on a girl patient who shows a peculiar cognitive and behavioural profile including high-functioning autism spectrum disorder (ASD) without intellectual disability and provide information on her developmental trajectory with the aim of expanding knowledge of the XGS clinical spectrum. On the basis of the current clinical case and the literature review, we also attempt to deepen understanding of behavioural and psychiatric manifestations associated with XGS. Results: In addition to the patient we described, a considerable rate of individuals with XGS display autistic symptoms or have been diagnosed with an autistic spectrum disorder. Moreover, the analysis of the few psychopathological profiles of patients with XGS described in the literature shows a frequent presence of aggressive and self-injurious behaviours that could be either an expression of autistic functioning or an additional symptom of the ASD evolution. A careful investigation of the abovementioned symptoms is therefore required, since they could represent a “red flag” for ASD

Multiple zero modes of the Dirac operator in three dimensions

One of the key properties of Dirac operators is the possibility of a degeneracy of zero modes. For the Abelian Dirac operator in three dimensions the construction of multiple zero modes has been sucessfully carried out only very recently. Here we generalise these results by discussing a much wider class of Dirac operators together with their zero modes. Further we show that those Dirac operators that do admit zero modes may be related to Hopf maps, where the Hopf index is related to the number of zero modes in a simple way.Comment: Latex file, 20 pages, no figure

Prevalence and clinical features of celiac disease in a cohort of italian children with autism spectrum disorders

Background: Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental conditions whose etiopathogenesis derives from a complex interaction between genetic liability and environmental factors. In this framework, mounting evidence suggests that immune system dysfunction could be a risk factor contributing to the development of ASD in at least a subpopulation of individuals. In particular, some studies suggest an association between celiac disease (CD)—a long‐term autoimmune disorder that primarily affects the small intestine triggered by the ingestion of gluten—and ASD, while others hypothesized a random link. This investigation aimed to evaluate the prevalence of CD in a large sample of school‐aged children with ASD and to characterize their clinical profile. Methods: Medical records of 405 children with ASD aged 5–11 years (mean age: 7.2 years; SD: 1.8 years) consecutively referred to a tertiary‐care university hospital between January 2014 and December 2018 were reviewed; among them, 362 had carried out serological testing for CD. Results: Nine patients with positive CD serology were identified, eight of which satisfied the criteria for CD diagnosis. The estimated CD prevalence in ASD children was 2.18% (95% CI, 0.8–3.7), which was not statistically different (1.58%; p = 0.36) from that of an Italian population, matched for age range, considered as a control group (95% CI, 1.26–1.90). Three out of the eight ASD patients with CD did not have any symptoms suggestive of CD. Conclusions: Our findings did not show a higher prevalence of CD in ASD children than in the control population, but could suggest the utility of routine CD screening, given its frequent atypical clinical presentation in this population

Preclinical atherosclerosis and metabolic syndrome increase cardio- and cerebrovascular events rate: a 20-year follow up

BACKGROUND: Intima-media thickness (IMT) is a validated marker of preclinical atherosclerosis and a predictor of cardiovascular events. PATIENTS: We studied a population of 529 asymptomatic patients (age 62\u2009\ub1\u200912.8 years), divided into two groups of subjects with and without Metabolic Syndrome (MetS). METHODS: All patients, at baseline, have had a carotid ultrasound evaluation and classified in two subgroups: the first one without atherosclerotic lesions and the second one with preclinical atherosclerosis (increased IMT or asymptomatic carotid plaque). Cardiovascular endpoints were investigated in a 20-years follow-up. RESULTS: There were 242 cardiovascular events: 144 among patients with MetS and 98 among in healthy controls (57.4% vs. 35.2%; P\u2009<\u20090.0001). 63 events occurred in patients with normal carotid arteries, while 179 events occurred in patients with preclinical atherosclerosis (31.8% vs. 54.1%; P\u2009<\u20090.0001). Of the 144 total events occurred in patients with MetS, 36 happened in the subgroup with normal carotid arteries and 108 in the subgroup with preclinical atherosclerosis (45% vs. 63.15%; P\u2009=\u20090.009). 98 events occurred in patients without MetS, of which 27 in the subgroup with normal carotid arteries and 71 in the subgroup with preclinical atherosclerosis (22.88% vs. 44.37%; P\u2009=\u20090.0003). In addition, considering the 63 total events occurred in patients without atherosclerotic lesions, 36 events were recorded in the subgroup with MetS and 27 events in the subgroup without MetS (45% vs. 22.88%; P\u2009=\u20090.0019). Finally, in 179 total events recorded in patients with preclinical carotid atherosclerosis, 108 happened in the subgroup with MetS and 71 happened in the subgroup without MetS (63.15% vs. 44.37%; P\u2009=\u20090.0009). The Kaplan-Meier function showed an improved survival in patients without atherosclerotic lesions compared with patients with carotid ultrasound alterations (P\u2009=\u20090.01, HR: 0.7366, CI: 0.5479 to 0.9904). CONCLUSIONS: Preclinical atherosclerosis leads to an increased risk of cardiovascular events, especially if it is associated with MetS

Are Vascularized Fibula Autografts a Long-lasting Reconstruction After Intercalary Resection of the Humerus for Primary Bone Tumors?

BackgroundA vascularized fibula graft (VFG) is the vascular autograft most frequently used to restore large segmental long bone defects, particularly in the upper limb. Because the use of a vascularized fibula involves an operation in an uninvolved extremity with potential morbidity, it is important to document that this type of reconstruction is successful in restoring function to the humerus. However, the long-term results of VFG after intercalary resection of the humeral diaphysis for bone tumors are still unknown.Questions/purposes(1) What was the complication rate of reconstruction? (2) What was the functional result after surgical treatment, as assessed by the Musculoskeletal Tumor Society (MSTS) score, the American Shoulder and Elbow Society (ASES) score, and Constant score? (3) What was the survivorship of these grafts free from revision and graft removal at 5, 10, and 15 years?MethodsBetween 1987 and 2021, 127 patients were treated at our institution with en bloc resection for a primary malignant or an aggressive benign bone tumor of the humerus; we excluded patients treated with extra-articular resection or amputation. Of those, 14% (18 of 127) were treated with intercalary resection of the humeral diaphysis for primary bone tumors and reconstruction with VFG, with or without a bulk allograft, and were analyzed in this retrospective study. Generally, our indications for reconstruction with VFG are intercalary resection of the humerus for primary malignant or aggressive benign bone tumors in patients with long life expectancy and high functional demands, in whom adequate bone stock of the proximal and distal epiphysis can be preserved. In 13 patients, VFG was used alone, whereas in five patients, a massive allograft was used. Our policy was to use VFG combined with a massive allograft in patients undergoing juxta-articular joint-sparing resections in which proximal osteotomy was performed close to the anatomic neck of the humerus to obtain more stable fixation and better tendinous reattachment of the rotator cuff and deltoid. All 18 patients who were treated with a VFG were available for follow-up at a minimum of 2 years (median follow-up 176 months, range 26 to 275 months), and although three have not been seen in the past 5 years and are not known to have died, they had 172, 163, and 236 months of follow-up, and were included. The median age at surgery was 25 years (range 2 to 63 years), the median humeral resection length was 15 cm (range 8 to 21 cm), and the median fibular length was 16 cm (range 12 to 23 cm). Complications and functional scores were ascertained by chart review that was performed by an individual not involved in patient care. Functional results were assessed with the MSTS score (range 0 to 30), the ASES score (range 0 to 100), and the Constant score (range 0% to 100%). Survivorship was estimated using a Kaplan-Meier survivorship estimator, which was suitable because there were few deaths in this series.ResultsSeven patients underwent a revision procedure (one radial nerve transient palsy because of screw impingement, four nonunions in three patients with one humeral head avascular necrosis, treatment for screw-related pain in one patient, and two VFG fractures), and one patient underwent VFG removal. Donor site complications were observed in four patients (one ankle valgus deformity and three claw toes - the first toe in two patients and the other toes in the third). At the final clinical control, at a median follow-up of 176 months (range 26 to 275 months), the median MSTS score was 30 of 30 (range 28 to 30), the median ASES score was 98.3 (range 93 to 100), and the median Constant score was 93.5% (range 79% to 100%). Revision-free survival was 71% (95% CI 53% to 96%) at 5 years and 57% (95% CI 37% to 88%) at 10 and 15 years; VFG removal-free survival was 94% (95% CI 83% to 100%) at 5, 10, and 15 years.ConclusionVFG appears to be an effective reconstructive option after humeral intercalary resection for primary bone tumors. These are complex procedures and should be performed by an experienced team of surgeons who recognize that complications may occur frequently in the first years after the procedure. The frequency of mechanical complications observed in the first 5 years postoperatively may be lessened by using long spanning-plate fixation, and if successful, this reconstruction provides a long-term, durable reconstruction with excellent functional results.Level of EvidenceLevel IV, therapeutic study

Hopf instantons in Chern-Simons theory

We study an Abelian Chern-Simons and Fermion system in three dimensions. In the presence of a fixed prescribed background magnetic field we find an infinite number of fully three-dimensional solutions. These solutions are related to Hopf maps and are, therefore, labelled by the Hopf index. Further we discuss the interpretation of the background field.Comment: one minor error corrected, discussion of gauge fixing added, some references adde