Turbulence Hierarchy in a Random Fibre Laser

Turbulence is a challenging feature common to a wide range of complex phenomena. Random fibre lasers are a special class of lasers in which the feedback arises from multiple scattering in a one-dimensional disordered cavity-less medium. Here, we report on statistical signatures of turbulence in the distribution of intensity fluctuations in a continuous-wave-pumped erbium-based random fibre laser, with random Bragg grating scatterers. The distribution of intensity fluctuations in an extensive data set exhibits three qualitatively distinct behaviours: a Gaussian regime below threshold, a mixture of two distributions with exponentially decaying tails near the threshold, and a mixture of distributions with stretched-exponential tails above threshold. All distributions are well described by a hierarchical stochastic model that incorporates Kolmogorov's theory of turbulence, which includes energy cascade and the intermittence phenomenon. Our findings have implications for explaining the remarkably challenging turbulent behaviour in photonics, using a random fibre laser as the experimental platform.Comment: 9 pages, 5 figure

Changes in insulin sensitivity and lipid profile markers following initial and secondary bouts of multiple eccentric exercises

An acute bout of eccentric exercise affects insulin sensitivity and lipid profile, but how the magnitude of muscle damage affects them is not clear. We compared changes in blood insulin sensitivity and lipid markers after the first (EC1) and second (EC2) eccentric exercise bouts. Fifteen sedentary young men performed arm, leg and trunk muscle eccentric exercises, and repeated them 2 weeks later. Fasting blood samples were taken before, 2 h and 1–5 days after each exercise bout to analyze plasma creatine kinase (CK) activity, serum glucose (GLU), insulin, homeostasis model assessment (HOMA), triacylglycerols (TG), total (TC) and low- (LDLC) and high-density lipoprotein cholesterol (HDLC) concentrations as well as TC/HDLC ratio. Changes in these measures were compared between bouts and relationships to peak plasma CK activity were analyzed. Plasma CK activity increased (p \u3c 0.05) after EC1 (peak: 101,668 ± 58,955 IU/L) but not after EC2. The magnitude of changes in GLU (peak after EC1: 26 ± 10% vs. EC2: 7 ± 6%), insulin (46 ± 27% vs. 15 ± 8%), HOMA (86 ± 48% vs. 24 ± 15%), TC (−20 ± 5% vs. −6 ± 4%), TG (−32 ± 11% vs. −6 ± 3%), LDHC (−47 ± 15% vs. −12 ± 9%), HDLC (35 ± 26% vs. 7 ± 4%), and TC/HDLC ratio (−139 ± 13% vs. −11 ± 7%) were significantly greater after EC1 than EC2. Peak plasma CK activity was significantly (p \u3c 0.05) correlated with the peak changes in blood insulin sensitivity and lipid markers for the combined data of EC1 and EC2. These results suggest that the greater the magnitude of muscle damage, the greater the magnitude of changes in the insulin sensitivity to a negative direction and lipid markers to a positive direction

New segregates from the Neotropical genus Stryphnodendron (Leguminosae, Caesalpinioideae, mimosoid clade)

Non-monophyly is a prominent issue in mimosoid legumes, even in some of the less speciose genera such as the neotropical genus Stryphnodendron. This genus includes 35 species occurring from Nicaragua to Southern Brazil mostly in humid forests and savannas. Previous taxonomic studies of Stryphnodendron have highlighted morphologically distinct groups within the genus, recognized by differences on leaves (number of pinnae and size of leaflets), inflorescences (a simple or compound thyrse), and fruit types (legume, nucoid legume or follicle). Recent phylogenetic analyses have confirmed the non-monophyly of Stryphnodendron, supporting the recognition of three independent and morphologically well-delimited genera. Here we re-circumscribe Stryphnodendron and propose the two new genera Gwilymia and Naiadendron. In addition, we also provide an updated taxonomic account of the closely related genus Microlobius, including the proposal of a lectotype for the single species in the genus

Renal tubular dysfunction in patients with American cutaneous leishmaniasis

Renal dysfunction seen in patients with American cutaneous leishmaniasis (ACL) has been attributed to the use of antimonials for treatment. To determine whether ACL itself causes tubular dysfunction, we measured renal function in 37 patients with ACL prior to their treatment and compared results to that in 10 healthy volunteers of similar mean age. None of the patients presented with glomerular dysfunction; however, 27 had a urinary concentrating defect. There was no statistical difference between groups in the pre- and post-desmopressin test of urine osmolality, but the post-test urine osmolality of the controls was significantly higher. Urinary AQP2 levels, determined by western blot of isolated exosomes, were found to be significantly lower in patients than in controls, whereas that of the cotransporter (NKCC2) was significantly higher. A urinary acidification defect (post-test pH greater than 5.50 following calcium chloride) was found in 15 patients. Pretest plasma bicarbonate was below normal in 12 patients as was the pretest plasma pH in 14. Expression of the Na/H exchanger (NHE3), H+-ATPase, and pendrin were all significantly higher in patients with ACL than in controls. A combined urinary concentration and acidification defect was found in 12 patients. Thus, the urinary concentrating defect of ACL may be caused by decreased AQP2, with increased NKCC2 compensatory. Pendrin upregulation may be related to the urinary acidification defect with increased NHE3 and H+-ATPase also compensatory. Hence, ACL can cause asymptomatic renal tubular dysfunction

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Search for Kaluza-Klein Graviton Emission in ppˉp\bar{p} Collisions at s=1.8\sqrt{s}=1.8 TeV using the Missing Energy Signature

We report on a search for direct Kaluza-Klein graviton production in a data sample of 84 ${pb}^{-1}$ of \ppb collisions at $\sqrt{s}$ = 1.8 TeV, recorded by the Collider Detector at Fermilab. We investigate the final state of large missing transverse energy and one or two high energy jets. We compare the data with the predictions from a $3+1+n$-dimensional Kaluza-Klein scenario in which gravity becomes strong at the TeV scale. At 95% confidence level (C.L.) for $n$=2, 4, and 6 we exclude an effective Planck scale below 1.0, 0.77, and 0.71 TeV, respectively.Comment: Submitted to PRL, 7 pages 4 figures/Revision includes 5 figure

Measurement of the average time-integrated mixing probability of b-flavored hadrons produced at the Tevatron

We have measured the number of like-sign (LS) and opposite-sign (OS) lepton pairs arising from double semileptonic decays of $b$ and $\bar{b}$-hadrons, pair-produced at the Fermilab Tevatron collider. The data samples were collected with the Collider Detector at Fermilab (CDF) during the 1992-1995 collider run by triggering on the existence of $\mu \mu$ and $e \mu$ candidates in an event. The observed ratio of LS to OS dileptons leads to a measurement of the average time-integrated mixing probability of all produced $b$-flavored hadrons which decay weakly, $\bar{\chi} = 0.152 \pm 0.007$ (stat.) $\pm 0.011$ (syst.), that is significantly larger than the world average $\bar{\chi} = 0.118 \pm 0.005$.Comment: 47 pages, 10 figures, 15 tables Submitted to Phys. Rev.