Isomeric Character of the Lowest Observed 4^{+} State in ^{44}S

Previous experiments observed a 4^{+} state in the N=28 nucleus ^{44}S and suggested that this state may exhibit a hindered E2-decay rate, inconsistent with being a member of the collective ground state band. We populate this state via two-proton knockout from a beam of exotic ^{46}Ar projectiles and measure its lifetime using the recoil distance method with the GRETINA γ-ray spectrometer. The result, 76(14)_{stat}(20)_{syst}  ps, implies a hindered transition of B(E2;4^{+}→2_{1}^{+})=0.61(19) single-particle or Weisskopf units strength and supports the interpretation of the 4^{+} state as a K=4 isomer, the first example of a high-K isomer in a nucleus of such low mass.

Evolution of collectivity in 72Kr: evidence for rapid shape transition

The transition rates from the yrast 2+ and 4+ states in the self-conjugate 72Kr nucleus were studied via lifetime measurements employing the GRETINA array with a novel application of the recoil-distance method. The large collectivity observed for the 4+→2+ transition suggests a prolate character of the excited states. The reduced collectivity previously reported for the 2+→0+ transition was confirmed. The irregular behavior of collectivity points to the occurrence of a rapid oblate-prolate shape transition in 72Kr, providing stringent tests for advanced theories to describe the shape coexistence and its evolution.

Brucella melitensis infection following military duty in Iraq

Brucellosis is a common zoonotic disease worldwide; however, few cases are reported in the US. Brucella melitensis infections are primarily acquired via consumption of high-risk foods or travel to endemic areas. We describe a case of B. melitensis infection in a Tennessee soldier following deployment in Iraq. Initial symptoms included knee and back pain. Culture of an aspirate of the left sacroiliac joint yielded B. melitensis. Genetic analysis indicated that this isolate came from the Middle East. Investigation of laboratory workers identified risky exposures and positive serology prompting post-exposure prophylaxis. Military personnel and other travellers should be advised to reduce risk regarding food consumption and animal contact in endemic areas. Additionally, medical providers should remain vigilant for non-endemic zoonoses among recent travellers.

Direct binding to and tyrosine phosphorylation of the alpha subunit of the type I interferon receptor by p135tyk2 tyrosine kinase

Binding of type I interferons (IFNs) to their receptors induces rapid tyrosine phosphorylation of multiple proteins, including the alpha and beta subunits of the receptor, the polypeptides that form the transcriptional activator ISGF3 alpha (Stat113, Stat84, and Stat91), and the p135tyk2 and Jak-1 tyrosine kinases. In this report, we demonstrate that the alpha subunit of the type I IFN receptor (IFN-R) corresponds to the product of a previously cloned receptor subunit cDNA and, further, that the p135tyk2 tyrosine kinase directly binds and tyrosine phosphorylates this receptor subunit. Glutathione S-transferase (GST) fusion proteins encoding the different regions of the cytoplasmic domain of the alpha subunit can bind the p135tyk2 contained in human cell lysates. The association between the alpha subunit and Tyk2 was demonstrated by immunoblotting with anti-Tyk2 and antiphosphotyrosine antibodies and by using an in vitro kinase assay. Analogous experiments were then performed with recombinant baculoviruses encoding constitutively active Jak family tyrosine kinases. In this case, p135tyk2, but not Jak-1 or Jak-2 protein, binds to the GST-IFN-R proteins, suggesting that the interaction between these two proteins is both direct and specific. We also demonstrate that Tyk2, from extracts of either IFN alpha-treated human cells or insect cells infected with the recombinant baculoviruses, can catalyze in vitro phosphorylation of GST-IFN-R protein in a specific manner. Deletion mutants of the GST-IFN-R protein were used to localize both the binding and tyrosine phosphorylation site(s) to a 46-amino-acid juxtamembrane region of the alpha subunit, which shows sequence homology to functionally similar regions of other cytokine receptor proteins. These data support the hypothesis that the Tyk2 protein functions as part of a receptor complex to initiate intracellular signaling in response to type I IFNs.

Townley anatomic total knee arthroplasty using total tibial component with cruciate release

The results (average follow-up of 29 months) of the Townley anatomic knee replacement utilizing cruciate release with total tibial component variant is presented in 72 patients with 88 knee replacements. Postoperatively, 94% of the patients had mild or no pain, 99% were able to walk outdoors with minor or no restriction, 82% had flexion of greater than 80 degrees. Ninety-eight per cent of the patients were realigned within 10 degrees of varus/valgus postoperatively. Revision surgery was required in four cases for loosening and in one case for infection. Resurfacing total knee replacements, including the Townley type, appear to be approaching an acceptable level of efficiency and performance, but extensive long-term follow-up is essential for a definitive evaluation of this method.