Publisher Correction: Very-high-energy particle acceleration powered by the jets of the microquasar SS 433

In this Letter, owing to a production error, the penultimate version of the PDF was published. The HTML version was always correct. The PDF has been corrected online.

Extended gamma-ray sources around pulsars constrain the origin of the positron flux at Earth

The unexpectedly high flux of cosmic-ray positrons detected at Earth may originate from nearby astrophysical sources, dark matter, or unknown processes of cosmic-ray secondary production. We report the detection, using the High-Altitude Water Cherenkov Observatory (HAWC), of extended tera-electron volt gamma-ray emission coincident with the locations of two nearby middle-aged pulsars (Geminga and PSR B0656+14). The HAWC observations demonstrate that these pulsars are indeed local sources of accelerated leptons, but the measured tera-electron volt emission profile constrains the diffusion of particles away from these sources to be much slower than previously assumed. We demonstrate that the leptons emitted by these objects are therefore unlikely to be the origin of the excess positrons, which may have a more exotic origin.

A new class of tunable hypersonic phononic crystals based on polymer-tethered colloids

The design and engineering of hybrid materials exhibiting tailored phononic band gaps are fundamentally relevant to innovative material technologies in areas ranging from acoustics to thermo-optic devices. Phononic hybridization gaps, originating from the anti-crossing between local resonant and propagating modes, have attracted particular interest because of their relative robustness to structural disorder and the associated benefit to 'manufacturability'. Although hybridization gap materials are well known, their economic fabrication and efficient control of the gap frequency have remained elusive because of the limited property variability and expensive fabrication methodologies. Here we report a new strategy to realize hybridization gap materials by harnessing the 'anisotropic elasticity' across the particle-polymer interface in densely polymer-tethered colloidal particles. Theoretical and Brillouin scattering analysis confirm both the robustness to disorder and the tunability of the resulting hybridization gap and provide guidelines for the economic synthesis of new materials with deliberately controlled gap position and width frequencies.

Merosin-deficient congenital muscular dystrophy in two siblings

Congenital muscular dystrophies are a group of heterogeneous inherited autosomal recessive disorders. The so-called 'pure' or 'occidental' form is further divided into merosin-positive and merosin-negative subgroups. Merosin is also expressed in the nervous system and its deficiency could affect development of the nervous system. The authors report two siblings with merosin-negative congenital muscular dystrophy. The clinical picture, biopsy findings, and abnormalities as detected by the magnetic resonance imaging of the two patients are presented.

Thrombotic thrombocytopenic purpura as a rare complication in childhood systemic lupus erythematosus: case report and literature review

Thrombotic thrombocytopenic purpura is a rare but serious condition in childhood. It can be idiopathic or a complication of other diseases or drug therapy. We report on a 12-year-old Chinese girl who presented with fulminant systemic lupus erythematosus with progressive renal failure, pancytopenia, and cerebral dysfunction due to thrombotic thrombocytopenic purpura. The patient also had Pneumocystis carinii pneumonia, Pseudomonas septicaemia, and Herpes zoster infections as a result of immunosuppressive treatment. She responded to combined therapy with pulse methylprednisolone, cyclophosphamide, plasmapheresis, and intensive care support, and completely recovered renal and neurological function. A review of the English-language medical literature since 1968 identified 20 other paediatric cases of systemic lupus erythematosus and thrombotic thrombocytopenic purpura. Clinical features, treatment, and outcome of these cases are presented and discussed. Early recognition is important, and although plasmapheresis is not of proven benefit in severe cases of systemic lupus erythematosus, it is life-saving in lupus-related thrombotic thrombocytopenic purpura and must be instituted early to avoid a poor outcome.

Splenic rupture in a newborn

Traumatic rupture of the spleen in the newborn is a rare event and is seldom reported in the literature. It can occur to an abnormally enlarged spleen or to a normal spleen. In the latter, it usually is associated with difficult delivery. Previously, the majority of patients died probably because of delayed or missed diagnoses. The classic presentation is a triad of bleeding, abdominal distension, and hemoperitoneum. High index of suspicion and improvement in diagnostic tools like ultrasonography and computed tomography are important contributions in early diagnosis so that appropriate treatment can be implemented. Splenectomy is no longer the standard treatment because it increases the chance of postsplenectomy sepsis. Instead, treatment should aim for hemostasis and preservation of spleen. The authors present a case of traumatic rupture of spleen in a normal newborn with normal labor and delivery. The first symptom began at 16 hours of age and evolved to a full-blown classic picture. The baby was saved without splenectomy, and the recovery was smooth and uneventful. This is probably the first reported case of a patient treated without splenectomy in this locality. Discussion of the condition and review of the literature also are presented.