Exact and Scaling Form of the Bipartite Fidelity of the Infinite XXZ Chain

We find an exact expression for the bipartite fidelity f=|'|^2, where |vac> is the vacuum eigenstate of an infinite-size antiferromagnetic XXZ chain and |vac>' is the vacuum eigenstate of an infinite-size XXZ chain which is split in two. We consider the quantity -ln(f) which has been put forward as a measure of quantum entanglement, and show that the large correlation length xi behaviour is consistent with a general conjecture -ln(f) ~ c/8 ln(xi), where c is the central charge of the UV conformal field theory (with c=1 for the XXZ chain). This behaviour is a natural extension of the existing conformal field theory prediction of -ln(f) ~ c/8 ln(L) for a length L bipartite system with 0<< L <<xi.Comment: 6 page

Spring sown oats for hay - Variety trials Denmark Research Station.

The practice of ploughing paddocks in late winter or early spring and the sowing of oats in August and September to cut for hay in November has many advantages in the higher rainfall areas in the south of the State. Trials conducted at the Denmark Research Station from 1954 onward indicate that Fulghum, Kent and Avon oats are the most suitable varieties for spring planting in that distric

Expression and function of calcium-activated potassium channels following in-stent restenosis in a porcine coronary artery model

AbstractIn-stent restenosis (ISR) occurs due to proliferation and migration of smooth muscle cells from media to intima resulting in re-narrowing of the vessel lumen. This study aims to investigate changes in the three main KCa channels in response to stent implantation in porcine coronary arteries as their expression and function in ISR is yet to be defined. Twenty-eight days after stent implantation, immunofluorescent labelling with anti-desmin and anti-vWF confirm the presence of both endothelial and smooth muscle cells within the neointimal layer. Using real-time PCR, significant increase in the SK3 and IKCa and BKCa channel mRNA was observed within this layer alone. Western blot analysis confirms the expression of KCa channels in neointima. Although expression of BKCa was increased in the neointima in comparison with medial region of the artery, microelectrode recordings showed that the function of this channel was unchanged. However, the presence of functional BKCa in both medial and intimal cells suggests that smooth muscle cells migration may contribute to neointimal hyperplasia.Functional analysis using 1-EBIO and Bradykinin produced hyperpolarization of neointimal but not medial myocytes, which indicated the expression of functional endothelial SK3 and IKCa in the former and not in the latter. The expression of IKCa and SK3 within the neointimal layer suggested that some degree of recovery of both endothelial as well as smooth muscle regeneration had occurred. Future development of selective modulators of IKCa and SK3 channels may decrease the progression of ISR and improve coronary vascular function after stent placement, and is an area for future investigation

Walking with giants: The challenges of variant impact assessment in the giant sarcomeric protein titin

Titin, the so-called “third filament” of the sarcomere, represents a difficult challenge for the determination of damaging genetic variants. A single titin molecule extends across half the length of a sarcomere in striated muscle, fulfilling a variety of vital structural and signaling roles, and has been linked to an equally varied range of myopathies, resulting in a significant burden on individuals and healthcare systems alike. While the consequences of truncating variants of titin are well-documented, the ramifications of the missense variants prevalent in the general population are less so. We here present a compendium of titin missense variants—those that result in a single amino-acid substitution in coding regions—reported to be pathogenic and discuss these in light of the nature of titin and the variant position within the sarcomere and their domain, the structural, pathological, and biophysical characteristics that define them, and the methods used for characterization. Finally, we discuss the current knowledge and integration of the multiple fields that have contributed to our understanding of titin-related pathology and offer suggestions as to how these concurrent methodologies may aid the further development in our understanding of titin and hopefully extend to other, less well-studied giant proteins. This article is categorized under: Cardiovascular Diseases > Genetics/Genomics/Epigenetics Congenital Diseases > Genetics/Genomics/Epigenetics Congenital Diseases > Molecular and Cellular Physiology

Probing the folding pathway of a β-clam protein with single-tryptophan constructs

Background: Cellular retinoic acid binding protein I (CRABPI) is a small, predominantly β-sheet protein with a simple architecture and no disulfides or cofactors. Folding of mutants containing only one of the three native tryptophans has been examined using stopped-flow fluorescence and circular dichroism at multiple wavelengths.Results: Within 10 ms, the tryptophan fluorescence of all three mutants shows a blue shift, and stopped-flow circular dichroism shows significant secondary structure content. The local environment of Trp7, a completely buried residue located near the intersection of the N and C termini, develops on a 100 ms time scale. Spectral signatures of the other two tryptophan residues (87 and 109) become native-like in a 1 s kinetic phase.Conclusions:Formation of the native β structure of CRABPI is initiated by rapid hydrophobic collapse, during which local segments of chain adopt significant secondary structure. Subsequently, transient yet specific interactions of amino acid residues restrict the arrangement of the chain topology and initiate long-range associations such as the docking of the N and C termini. The development of native tertiary environments, including the specific packing of the β-sheet sidechains, occurs in a final, highly cooperative step simultaneous with stable interstrand hydrogen bonding

The Greatest Generation II: a Narrative Study of Post-9/11 Veterans in Higher Education

The Post 9/11 GI Bill is the most lucrative version of the GI Bill since the original World War II version. As such, veterans are entering colleges and universities around the country at an increased rate that is expected to continue for the foreseeable future. Despite this growing number of student veterans, it is unclear if university faculty and staff are prepared to deal with their unique needs. This study examined the transitional issues faced by veterans as they leave the military and enter higher education. Moreover, it sought to explore how colleges can provide support services that promote a positive and rewarding college experience for student veterans. Three questions guided this research: (a) How do veterans describe their transition from military to civilian life? (b) What stories do Post 9/11 veterans tell about their experiences in higher education? and (c) How do Post 9/11 veterans describe what faculty and staff can do to better serve their needs. To address these questions, a qualitative narrative research design was applied and semi-structured interviews were conducted with 13 veterans who successfully completed college following military service. Through analysis of the data, five findings revealed that veterans in college have unique needs that need to be addressed. The findings revealed that while veterans face unique needs when entering higher education, they also possess a maturity level that helps them overcome challenges associated with higher education. Findings also revealed that peer-to-peer support is crucial to veterans successfully completing college. As the number of veterans in college continues to increase, so does the need for university administrators to gain a deeper understanding of their issues.Ed.D., Educational Leadership and Management -- Drexel University, 201

Estimation of the within-herd transmission rates of bovine viral diarrhoea virus in extensively grazed beef cattle herds

International audienceMany research groups have developed mathematical models to simulate the dynamics of BVDV infections in cattle herds. However, most models use estimates for within-herd BVDV transmission rates that are either based on expert opinion or adapted from other dairy herd simulation models presented in the literature. There is currently little information on the transmission rates for BVDV in extensively grazed beef herds partly due to the logistical challenges in obtaining longitudinal data of individual animal’s seroconversion, and it may not be appropriate to apply the same transmission rates from intensive dairy herds given the significant differences in herd demographics and management. To address this knowledge gap, we measured BVDV antibody levels in 15 replacement heifers in each of 75 New Zealand beef breeding farms after their first calving and again at pregnancy scanning or weaning to check for seroconversion. Among these, data from 9 farms were used to infer the within-herd BVDV transmission rate with an approximate Bayesian computation method. The most probable within-herd BVDV transmission rate was estimated as 0.11 per persistently infected (PI) animal per day with a 95% highest posterior density interval between 0.03 and 0.34. This suggests that BVDV transmission in extensively grazed beef herds is generally slower than in dairy herds where the transmission rate has been estimated at 0.50 per PI animal per day and therefore may not be sufficient to ensure that all susceptible breeding females gain adequate immunity to the virus before the risk period of early pregnancy for generating new PI calves

Bi-partite entanglement entropy in integrable models with backscattering

In this paper we generalise the main result of a recent work by J. L. Cardy and the present authors concerning the bi-partite entanglement entropy between a connected region and its complement. There the expression of the leading order correction to saturation in the large distance regime was obtained for integrable quantum field theories possessing diagonal scattering matrices. It was observed to depend only on the mass spectrum of the model and not on the specific structure of the diagonal scattering matrix. Here we extend that result to integrable models with backscattering (i.e. with non-diagonal scattering matrices). We use again the replica method, which connects the entanglement entropy to partition functions on Riemann surfaces with two branch points. Our main conclusion is that the mentioned infrared correction takes exactly the same form for theories with and without backscattering. In order to give further support to this result, we provide a detailed analysis in the sine-Gordon model in the coupling regime in which no bound states (breathers) occur. As a consequence, we obtain the leading correction to the sine-Gordon partition function on a Riemann surface in the large distance regime. Observations are made concerning the limit of large number of sheets.Comment: 22 pages, 2 figure