883 research outputs found
Heavy Vector-like Top Partners at the LHC and flavour constraints
We consider the phenomenology at the Large Hadron Collider of new heavy
vector-like quarks which couple mainly to the third generation quarks via
Yukawa interactions, with special emphasis on non-standard doublet
representations which are less constrained from present data. We also discuss
in detail the flavour limits at tree level and loop level and implications of a
generalised CKM mixing matrix to these cases.Comment: 45 pages, 20 figures, 8 tables. Updated limits in the B-physics part,
typos corrected, minor modifications in the LHC par
Membranes for spontaneous separation of pedestrian counter flows
Designing efficient traffic lanes for pedestrians is a critical aspect of
urban planning as walking remains the most common form of mobility among the
increasingly diverse methods of transportation. Herein, we investigate
pedestrian counter flows in a straight corridor, in which two groups of people
are walking in opposite directions. We demonstrate, using a molecular dynamics
approach applying the social force model, that a simple array of obstacles
improves flow rates by producing flow separations even in crowded situations.
We also report on a developed model describing the separation behavior that
regards an array of obstacles as a membrane and induces spontaneous separation
of pedestrians groups. When appropriately designed, those obstacles are fully
capable of controlling the filtering direction so that pedestrians tend to keep
moving to their left (or right) spontaneously. These results have the potential
to provide useful guidelines for industrial designs aimed at improving
ubiquitous human mobility.Comment: Manuscript accepted for publication in Europhysics Letter
Churg-Strauss Syndrome with Necrosis of Toe Tips
Churg-Strauss syndrome (CSS) is a granulomatous necrotizing vasculitis of unknown etiology associated with bronchial asthma. Despite affecting small to medium-sized vessels, necrosis of the digits due to vasculitis is extremely rare. We report a case of CSS with necrosis of the toe tips. A 37-year-old woman with asthma, who had been diagnosed with CSS 2 years ago, was admitted to our hospital with an exacerbation of CSS. The patient had a high grade fever and complained of abdominal pain and numbness of the lower extremities. Blood examination revealed marked eosinophilia. The fever pattern, abdominal pain and blood eosinophilia showed improvement by combination treatment with prednisolone and cyclophosphamide. However, the color of her right toe tips changed, and necrosis finally resulted despite antithrombotic therapy. Arteriography showed narrowing of the dorsalis pedis artery and of the more peripheral arteries of her right leg. Stump plasty with negative pressure dressing therapy for the toe tips, but not amputation, was done to preserve the leg function. While numbness of the extremities remained, no recurrence of necrosis was seen. Clinicians need to be aware that rare complications of CSS, including necrosis of the digits, can occur
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