Infinite number of MSSMs from heterotic line bundles?

We consider heterotic E8xE8 supergravity compactified on smooth Calabi-Yau manifolds with line bundle gauge backgrounds. Infinite sets of models that satisfy the Bianchi identities and flux quantization conditions can be constructed by letting their background flux quanta grow without bound. Even though we do not have a general proof, we find that all examples are at the boundary of the theory's validity: the Donaldson-Uhlenbeck-Yau equations, which can be thought of as vanishing D-term conditions, cannot be satisfied inside the Kaehler cone unless a growing number of scalar Vacuum Expectation Values (VEVs) is switched on. As they are charged under various line bundles simultaneously, the gauge background gets deformed by these VEVs to a non-Abelian bundle. In general, our physical expectation is that such infinite sets of models should be impossible, since they never seem to occur in exact CFT constructions.Comment: LaTeX, 8 pages, 4 tables, some references and comments adde

Evaluation of Compton scattering sequence reconstruction algorithms for a portable position sensitive radioactivity detector based on pixelated Cd(Zn)Te crystals

We present extensive simulation studies on the performance of algorithms for the Compton sequence reconstruction used for the development of a portable spectroscopic instrument (COCAE), with the capability to localize and identify radioactive sources, by exploiting the Compton scattering imaging. Various Compton Sequence reconstruction algorithms have been compared using a large number of simulated events. These algorithms are based on Compton kinematics, as well as on statistical test criteria that exploit the redundant information of events having two or more photon interactions in the active detector's volume. The efficiency of the best performing technique is estimated for a wide range of incident gamma-ray photons emitted from point-like gamma sources.Comment: 16 pages, 17 figure

Anatomical variations of the superficial and deep palmar arches

The use of radial arteries as an arterial bypass conduit is an invasive procedure which is becoming popular among various medical centres. The greatest risk associated with harvesting the radial artery is ischaemia of the soft tissues of the hand. In this study we dissected 200 hands derived from 100 formalin-fixed cadavers in order to identify arterial patterns that will allow safe removal of the radial artery for use in bypass procedures. A complete superficial palmar arch (SPA) was found in 90% of the cases and divided into 5 types, while the remaining 10% possessed an incomplete palmar arch. Types of SPA are designated by the letter S. In type S-I (40%), the SPA is formed by anastomosis of the superficial volar branch of the radial artery to the ulnar artery. Type S-II (35%) is formed entirely of the ulnar artery. Type S-III (15%) is formed by anastomosis of the ulnar and median arteries. Type S-IV (6%) is formed by anastomosis of the ulnar, radial, and median arteries and Type S-V (4%) is formed by a branch of the deep palmar arch (DPA) communicating with the SPA.DPA was identified in all specimens and classified into three types, all designated by the letter D. Type D-I (60%) is formed by anastomosis of the deep volar branch of the radial artery and the inferior deep branch of the ulnar branch. Type D-II (30%) is formed by anastomosis of the deep volar branch of the radial artery and the superior deep branch of the ulnar artery. Type D-III (10%) is formed by anastomosis of the deep volar branch of the radial artery with both deep branches of the ulnar artery. This data could provide an important source of information for vascular surgeons harvesting radial arteries

Fat herniation through the canal of Schwalbe

The authors report a case of fat herniation through the canal of Schwalbe noted in a female cadaver during abdominopelvic dissection. Perineal hernias are rare hernias, and herniations through the hiatus of Schwalbe represent a rare posterior lateral perineal hernia. While these hernias are extremely rare, anatomists and surgeons should be aware of them, and the clinical significance and manifestations which may occur with these hernias

Not All Worms Were Created Equal

[Extract] Whilst we support the need to report safety outcomes from experimental therapy of any kind, including the use of helminths as therapy, we believe that it is important to critically examine the causal relationship of the reported event to the proposed etiology so that a balanced view of the cause and effect be arrived at. This is particularly the case in an uncontrolled setting where formal processes for documenting and reporting experimental therapy may not be in place. Recent reviews of studies with one of the most widely used helminths, the anthropophilic hookworm, Necator americanus, have shown this helminth to be safe and well tolerated in hundreds of individuals by numerous research groups across Australia, the US and Europe (1–3). In BMC Pulmonary Medicine (4), Zeynalyan and colleagues report rapidly progressive respiratory failure in a patient with significant comorbidities, including systemic sclerosis, interstitial lung disease and pulmonary hypertension after self-administration of N. americanus larvae that were purchased over the internet. Here we raise some concerns about this report

Experimental human hookworm infection: a narrative historical review

In 1896, a serendipitous laboratory accident led to the understanding that hookworms propagate infection by penetrating skin, a theory that was then confirmed with the first experimental human infection, reported in 1901. Experimental human infections undertaken in the 20th century enabled understanding of the natural history of infection and the immune response. More recently, experimental hookworm infection has been performed to investigate the immunomodulatory potential of hookworm infection and for the evaluation of hookworm vaccines and chemotherapeutic interventions. Experimental human hookworm infection has been proven to be safe, with no deaths observed in over 500 participants (although early reports predate systematic adverse event reporting) and no serious adverse events described in over 200 participants enrolled in contemporary clinical trials. While experimental human hookworm infection holds significant promise, as both a challenge model for testing anti-hookworm therapies and for treating various diseases of modernity, there are many challenges that present. These challenges include preparation and storage of larvae, which has not significantly changed since Harada and Mori first described their coproculture method in 1955. In vitro methods of hookworm larval culture, storage, and the development of meaningful potency or release assays are required. Surrogate markers of intestinal infection intensity are required because faecal egg counts or hookworm faecal DNA intensity lack the fidelity required for exploration of hookworm infection as a vaccine/drug testing platform or as a regulated therapy

Ectopic arachnoid granulation involving a rare intracranial venous sinus variant

Arachnoid granulations are hypertrophied arachnoid villi, which extend from the subarachnoid space into the venous system and aid in the passive filtration and reabsorption of cerebrospinal fluid. These macroscopic structures have been described in various locations, with the transverse and sigmoid sinuses seen as normal variants on imaging. Here we present the occurrence of an enlarged arachnoid granulation at the foramen rotundum where a variant intracranial venous sinus was identified during routine dissection. Variations, such as the one described herein, should be recognised by those who operate or interpret images of the skull base

Vaccination with Schistosoma mansoni cholinesterases reduces the parasite burden and egg viability in a mouse model of Schistosomiasis

Schistosomiasis is a neglected tropical disease caused by parasitic blood flukes of the genus Schistosoma, which kills 300,000 people every year in developing countries, and there is no vaccine. Recently, we have shown that cholinesterases (ChEs)—enzymes that regulate neurotransmission—from Schistosoma mansoni are expressed on the outer tegument surface and present in the excretory/secretory products of larval schistosomula and adult worms, and are essential for parasite survival in the definitive host, highlighting their utility as potential schistosomiasis vaccine targets. When treated in vitro with anti-schistosome cholinesterase (SmChE) IgG, both schistosomula and adult worms displayed significantly decreased ChE activity, which eventually resulted in parasite death. Vaccination with individual SmChEs, or a combination of all three SmChEs, significantly reduced worm burdens in two independent trials compared to controls. Average adult worm numbers and liver egg burdens were significantly decreased for all vaccinated mice across both trials, with values of 29–39% and 13–46%, respectively, except for those vaccinated with SmAChE1 in trial 1. Egg viability, as determined by egg hatching from liver homogenates, was significantly reduced in the groups vaccinated with the SmChE cocktail (40%) and SmAChE2 (46%). Furthermore, surviving worms from each vaccinated group were significantly stunted and depleted of glycogen stores, compared to controls. These results suggest that SmChEs could be incorporated into a vaccine against schistosomiasis to reduce the pathology and transmission of this debilitating disease