First-principle description of magnonic PdnFem multilayers

Ab-initio calculations are used to determine the parameters that determine magnonic band structure of PdnFem multilayers (n = 2, m <= 8). We obtain the layer-resolved magnetization, the exchange coupling, and the magnetic anisotropy of the Pd-Fe structures. The Fe moment is 3.0 mu(B) close to the Pd layers and 2.2 mu(B) in the middle of the Fe layers. An intriguing but not usually considered aspect is that the elemental Pd is nonmagnetic, similar to Cu spacer layers in other multilayer systems. This leads to a pre-asymptotic ferromagnetic coupling through the Pd (about 40 mJ/m(2)). Furthermore, the Pd acquires a small moment due to spin polarization by neighboring Fe atoms, which translates into magnetic anisotropy. The anisotropies are large, in the range typical for L1(0) structures, which is beneficial for high-frequency applications. (C) 2011 American Institute of Physics. doi:10.1063/1.3556763

EFFECTS OF CLIMATIC CONDITIONS ON MOUNTAIN ULTRA-MARATHON RUNNERS’ HEART RATE VARIABILITY AND PARASYMPATHETIC ACTIVITY

S. S. Sahota, P. K. Singh, I. J. Foster, A. L. Wookey, M. J. Rogers, C. Q. Malcolm, M.D. White Simon Fraser University, Burnaby, BC, Canada PURPOSE: Heart rate variability (HRV) can be employed to give an indication of parasympathetic activity as an index of fatigue. Following two 50 km mountain ultra-marathons, run on the same course but in different years and in differing climatic conditions, HRV was employed to assess fatigue of the runners. The root mean square of successive electrocardiogram R-R intervals (RMSSD), which reflects parasympathetic activity, was employed to give an index of fatigue, where a lower RMSSD value indicates greater fatigue. It was hypothesized that there would be a lower post-race RMSSD in 2014 when there was a greater heat stress relative to post-race RMSSD for the same race in 2015. METHODS: Five males volunteered for the study after an orientation session and completed a medical history, PAR-Q and informed consent forms for the study that was approved by the SFU Office of Research Ethics; one runner competed in both years. In both years, pre-race, and immediate post-race heart rate RMSSD was collected using chest heart rate straps and fitness computers. In 2014 the temperature was 22.3 ± 3.4°C (mean ±SD) and the ambient vapor pressure was 10.7 ± 0.3 mm Hg. For the 2015 race the temperature was 12.9 ± 4.5°C and ambient vapor pressure was 10.4 mm Hg. From each volunteer a 5 min section of the R-R data was analyzed using online software for HRV. The statistical analysis included a 2 factor non-repeated ANOVA with factors of Year (2014 and 2015) and Race Day Time (Pre-Race and Post-Race). The p-value set a 0.05. RESULTS: For RMSSD the main effect of Year (F=0.1, p=0.740) was not significant whereas there was a trend for an effect of Race Day Time (F=2.9, p=0.1). Pre-race RMSSD in 2014 was 34.7 ± 9.7 ms and the post-race RMSSD in 2014 was 19.3 ± 17.1 ms. In 2015, pre-race was 35.5 ± 18.1 ms, whereas the post-race value 23.9 ± 6.1 ms. CONCLUSION: The hypothesis that there would be a lower post-race RMSSD in 2014 when there was a greater heat stress compared to the same race in 2015 was not supported by the data. Supported by NSERC and CFI

Cefaléias em salvas: estudo das alterações autonômicas e outras manifestações associadas em 28 casos Cluster headache: study of autonomic alterations and other associated manifestations in 28 cases

As cefaléias de curta duração dividem-se entre aquelas com pouca ativação; autonômica e aquelas com importante ativação, este grupo inclui a cefaléia em salvas. Este trabalho tem por objetivo discutir a fisiopatologia da cefaléia em salvas, com maior enfoque nos fenômenos autonômicos, como injeção conjuntival, lacrimejamento, congestão nasal, rinorréia, semiptose e edema palpebral, mostrando o nítido envolvimento do núcleo salivatório superior com a propagação do estímulo doloroso, originado no nervo trigêmeo. As alterações autonômicas foram estudadas em 28 pacientes com cefaléia em salvas e as prevalentes foram o lacrimejamento e a hiperemia conjuntival.<br>The short lasting primary headaches are classified as those without autonomic activation and those with important activation, which includes the cluster headache. This study focuses on the pathophysiology of cluster headache mainly in its autonomic phenomenon (conjuntival injection, lacrimation, nasal congestion, rhinorrhoea, parcial ptosis and eyelid oedema) showing the involvement of superior salivatory nucleus with the pain stimulus propagation, which begins in the trigeminal nerve. The autonomic alterations were studied in 28 patients being lacrimation and conjuntival injection, the main features

Insights into the regulation of immunoglobulin light chain gene rearrangements via analysis of the κ light chain locus in λ myeloma

Accumulating evidence indicates that B cells may undergo sequential rearrangements at the light chain loci, despite already expressing light chain receptors. This phenomenon may occur in the bone marrow and, perhaps, in germinal centers. As immunoglobulin (Ig)κ light chains usually rearrange before Igλ light chains, we analysed, by polymerase chain reaction, the Igκ locus of bone marrow mononuclear cells from 29 patients with Igλ myeloma to identify earlier recombinations in marrow plasma cells. The results demonstrated that Igκ alleles were inactivated via the kappa-deleting element, presumably prior to Vκ-Jκ rearrangement, in many cases. Eighteen alleles (16 myeloma clones, 55%) showed Vκ–Jκ rearrangements, with increased utilization of 5‵ distant Vκ and 3′ distant Jκ gene segments (Jκ4, 56%), an indication of multiple sequential rearrangements. In-frame, potentially functional Vκ–Jκ rearrangements were found in approximately one-third of available rearrangements (as expected by chance), each one in different myeloma clones: three were germline encoded, while one had several nucleotide substitutions, suggesting inactivation after the onset of somatic hypermutation. Three of four potentially functional Vκ–Jκ rearrangements involved Vκ4–1, a segment considered to be associated with autoimmunity. These findings provide insights into the regulation of light chain rearrangements and support the view that B cells may occasionally undergo sequential light chain rearrangements after the onset of somatic hypermutation