Intestinal perforation due to adult tapeworm of Taenia: a case report and review of the literature

Taeniasis is an intestinal helminth infection due to adult tapeworms belonging to the genus Taenia. Taeniasis remains a major burden in low-income countries in Asia. We present a case of intestinal perforation caused by adult tapeworm of Taenia in a 50-year-old Nepali male. The patients presented to the hospital with severe abdominal pain and intermittent vomiting. Following clinical presentations and imaging features, gastrointestinal perforation was suspected. Surgical removal of adult tapeworm of Taenia, suspected to be T. saginata or T. asiatica, was carried out during exploratory laparotomy, which was followed by an uneventful postoperative period. In addition to case presentation, we systematically review published case reports on taeniasis-related intestinal perforation. A learning point from this case is clinician should maintain a clinical suspicion of taeniasis as a possible cause of intestinal perforation in endemic areas

Exact integral equation for the renormalized Fermi surface

The true Fermi surface of a fermionic many-body system can be viewed as a fixed point manifold of the renormalization group (RG). Within the framework of the exact functional RG we show that the fixed point condition implies an exact integral equation for the counterterm which is needed for a self-consistent calculation of the Fermi surface. In the simplest approximation, our integral equation reduces to the self-consistent Hartree-Fock equation for the counterterm.Comment: 5 pages, 1 figur

Van Hove singularity and spontaneous Fermi surface symmetry breaking in Sr3Ru2O7

The most salient features observed around a metamagnetic transition in Sr3Ru2O7 are well captured in a simple model for spontaneous Fermi surface symmetry breaking under a magnetic field, without invoking a putative quantum critical point. The Fermi surface symmetry breaking happens in both a majority and a minority spin band but with a different magnitude of the order parameter, when either band is tuned close to van Hove filling by the magnetic field. The transition is second order for high temperature T and changes into first order for low T. The first order transition is accompanied by a metamagnetic transition. The uniform magnetic susceptibility and the specific heat coefficient show strong T dependence, especially a log T divergence at van Hove filling. The Fermi surface instability then cuts off such non-Fermi liquid behavior and gives rise to a cusp in the susceptibility and a specific heat jump at the transition temperature.Comment: 11 pages, 4 figure

Direct mass measurements beyond the proton drip-line

First on-line mass measurements were performed at the SHIPTRAP Penning trap mass spectrometer. The masses of 18 neutron-deficient isotopes in the terbium-to-thulium region produced in fusion-evaporation reactions were determined with relative uncertainties of about $7\cdot 10^{-8}$, nine of them for the first time. Four nuclides ($^{144, 145}$Ho and $^{147, 148}$Tm) were found to be proton-unbound. The implication of the results on the location of the proton drip-line is discussed by analyzing the one-proton separation energies

Renormalized perturbation theory for Fermi systems: Fermi surface deformation and superconductivity in the two-dimensional Hubbard model

Divergencies appearing in perturbation expansions of interacting many-body systems can often be removed by expanding around a suitably chosen renormalized (instead of the non-interacting) Hamiltonian. We describe such a renormalized perturbation expansion for interacting Fermi systems, which treats Fermi surface shifts and superconductivity with an arbitrary gap function via additive counterterms. The expansion is formulated explicitly for the Hubbard model to second order in the interaction. Numerical soutions of the self-consistency condition determining the Fermi surface and the gap function are calculated for the two-dimensional case. For the repulsive Hubbard model close to half-filling we find a superconducting state with d-wave symmetry, as expected. For Fermi levels close to the van Hove singularity a Pomeranchuk instability leads to Fermi surfaces with broken square lattice symmetry, whose topology can be closed or open. For the attractive Hubbard model the second order calculation yeilds s-wave superconductivity with a weakly momentum dependent gap, whose size is reduced compared to the mean-field result.Comment: 18 pages incl. 6 figure

Fermi surface instabilities at finite Temperature

We present a new method to detect Fermi surface instabilities for interacting systems at finite temperature. We first apply it to a list of cases studied previously, recovering already known results in a very economic way, and obtaining most of the information on the phase diagram analytically. As an example, in the continuum limit we obtain the critical temperature as an implicit function of the magnetic field and the chemical potential $T_c(\mu,h)$. By applying the method to a model proposed to describe reentrant behavior in $Sr_3Ru_2O_7$, we reproduce the phase diagram obtained experimentally and show the presence of a non-Fermi Liquid region at temperatures above the nematic phase.Comment: 10 pages, 10 figure

Spontaneous breaking of four-fold rotational symmetry in two-dimensional electronic systems explained as a continuous topological transition

The Fermi liquid approach is applied to the problem of spontaneous violation of the four-fold rotational point-group symmetry ($C_4$) in strongly correlated two-dimensional electronic systems on a square lattice. The symmetry breaking is traced to the existence of a topological phase transition. This continuous transition is triggered when the Fermi line, driven by the quasiparticle interactions, reaches the van Hove saddle points, where the group velocity vanishes and the density of states becomes singular. An unconventional Fermi liquid emerges beyond the implicated quantum critical point.Comment: 6 pages, 4 figure

Increased prevalence of potential right-to-left shunting in children with sickle cell anaemia and stroke

'Paradoxical' embolization via intracardiac or intrapulmonary right-to-left shunts (RLS) is an established cause of stroke. Hypercoagulable states and increased right heart pressure, which both occur in sickle cell anaemia (SCA), predispose to paradoxical embolization. We hypothesized that children with SCA and overt stroke (SCA + stroke) have an increased prevalence of potential RLS. We performed contrasted transthoracic echocardiograms on 147 children (aged 2-19 years) with SCA + stroke) mean age 12·7 ± 4·8 years, 54·4% male) and a control group without SCA or stroke (n = 123; mean age 12·1 ± 4·9 years, 53·3% male). RLS was defined as any potential RLS detected by any method, including intrapulmonary shunting. Echocardiograms were masked and adjudicated centrally. The prevalence of potential RLS was significantly higher in the SCA+stroke group than controls (45·6% vs. 23·6%, P < 0·001). The odds ratio for potential RLS in the SCA + stroke group was 2·7 (95% confidence interval: 1·6-4·6) vs controls. In post hoc analyses, the SCA + stroke group had a higher prevalence of intrapulmonary (23·8% vs. 5·7%, P < 0·001) but not intracardiac shunting (21·8% vs. 18·7%, P = 0·533). SCA patients with potential RLS were more likely to report headache at stroke onset than those without. Intrapulmonary and intracardiac shunting may be an overlooked, independent and potentially modifiable risk factor for stroke in SCA

Global Philanthropy : Does Institutional Context Matter for Charitable Giving?

In this article, we examine whether and how the institutional context matters when understanding individuals' giving to philanthropic organizations. We posit that both the individuals' propensity to give and the amounts given are higher in countries with a stronger institutional context for philanthropy. We examine key factors of formal and informal institutional contexts for philanthropy at both the organizational and societal levels, including regulatory and legislative frameworks, professional standards, and social practices. Our results show that while aggregate levels of giving are higher in countries with stronger institutionalization, multilevel analyses of 118,788 individuals in 19 countries show limited support for the hypothesized relationships between institutional context and philanthropy. The findings suggest the need for better comparative data to understand the complex and dynamic influences of institutional contexts on charitable giving. This, in turn, would support the development of evidence-based practices and policies in the field of global philanthropy.Peer reviewe