Picosecond time-resolved energy transfer within C-phycocyanin aggregates of Mastigocladus laminosus

We have investigated by picosecond absorption experiments how the size of C-phycocyanin aggregates from Mastigocladus laminosus influences the excitation energy transfer kinetics. Going from C-phycocyanin monomers to trimers the lifetime of the faster energy transfer component decreased from 57 ± 4 to 27 ± 4 ps over most of the wavelength range (580–645 nm) studied. This change was interpreted as the opening of fast transfer channels (α-84 → β-84 and/or β-84 → β-84) between two adjacent monomers in the trimeric unit. The 57 ps lifetime is probably due mainly to the β-155 → β-84 energy transfer step. The intermediate lifetime decreased from about 300 ps in the monomer to 100–120 ps in the trimer. The former is believed to be dominated by the equilibration process α-84 a3 β-84, while the latter probably represents the time required for the excitation energy to reach thermodynamic equilibrium within the trimer. The lifetime of the longest components was about 1 ns in both systems. This indicates that the chromophores in these C-phycocyanin complexes are more exposed to non-radiative processes (like, for instance, isomerization) compared to the chromophores in intact phycobilisomes, where this lifetime typically is about 1.8 ns. The anisotropy relaxation closely followed the isotropic lifetimes in both systems. The anisotropy after the initial fast relaxation, r(∞), was 0.29 ± 0.04 in monomers and decreased to 0.15 ± 0.03 in trimers. Measurements of the steady-state fluorescence excitation anisotropy gave the same results within the experimental error

Electroweak and Top physics at ATLAS

The observations of electroweak boson (W, Z) and top quark pair (t¯t) production are among the key milestones for the early LHC physics programme. Production of t¯t, W and Z in association with jets are important backgrounds in various searches for physics beyond the Standard Model, and new physics may also give rise to additional production mechanisms or modification of the decay channels. This note summarizes √ the electroweak and top physics performed in ATLAS with Vs = 7TeV proton-proton collisions during 2010 and compares the observations with theoretical predictions

Palaeobiology, ecology, and distribution of stromatoporoid faunas in biostromes of the mid-Ludlow of Gotland

Six well exposed mid−Ludlow stromatoporoid−dominated reef biostromes in four localities from the Hemse Group in southeastern Gotland, Sweden comprise a stromatoporoid assemblage dominated by four species; Clathrodictyon mohicanum, “Stromatopora” bekkeri, Plectostroma scaniense, and Lophiostroma schmidtii. All biostromes investigated in this area (of approximately 30 km2) are interpreted to belong to a single faunal assemblage forming a dense accumulation of fossils that is probably the best exposed stromatoporoid−rich deposit of the Silurian. The results from this comprehensive study strengthen earlier interpretations of a combination of genetic and environmental control on growth−forms of the stromatoporoids. Growth styles are similar for stromatoporoids in all six biostromes. Differences in biostrome fabric are due to variations in the degree of disturbance by storms. The uniformity of facies and the widespread low−diversity fauna support the view that palaeoenvironmental conditions were similar across the area where these biostromes crop out, and promoted the extraordinary growth of stromatoporoids in this shallow shelf area

Significant Association of Streptococcus bovis with Malignant Gastrointestinal Diseases

Streptococcus bovis is a Gram-positive bacterium causing serious human infections, including endocarditis and bacteremia, and is usually associated with underlying disease. The aims of the current study were to compare prevalence of the bacterium associated with malignant and nonmalignant gastrointestinal diseases and to determine the susceptibility of the isolated strains to different antimicrobial agents. The result showed that the prevalence of S. bovis in stool specimens from patients with malignant or with nonmalignant gastrointestinal diseases was statistically significant. This result may support the idea that there is correlation between S. bovis and the malignant gastrointestinal diseases

The two-year impact of first generation protease inhibitor based antiretroviral therapy (PI-ART) on health-related quality of life

BACKGROUND: Protease inhibitor based antiretroviral therapy (PI-ART) was introduced in 1996 and has greatly reduced the incidence of HIV-related morbidity and mortality in the industrialised world. PI-ART would thus be expected to have a positive effect on health-related quality of life (HRQL). On the other hand, HRQL might be negatively affected by strict adherence requirements as well as by short and long-term adverse effects. The aim of this study was to assess the influence of two years of first generation PI-ART on HRQL in patients with a relatively advanced state of HIV-infection. Furthermore, we wanted to investigate the relation between developments in HRQL and viral response, self-reported adherence and subjective experience of adverse effects in patients with PI-ART. METHODS: HRQL was measured by the Swedish Health-Related Quality of Life Questionnaire (SWED-QUAL). Sixty-three items from the SWED-QUAL forms two single-item and 11 multi-item dimension scales. For this study, two summary SWED-QUAL scores (physical HRQL composite score and emotional HRQL composite score) were created through a data reduction procedure. At the 2-year follow-up measurement (see below), items were added to measure adherence and subjective experience of adverse effects. Demographic and medical data were obtained from specific items in the questionnaires and from the medical files. Seventy-two patients who were among the first to receive PI-ART (indinavir or ritonavir based) responded to the questionnaire before the start of PI-ART. Of these, 54 responded to the same instrument after two years of treatment (13 had died, four had changed clinic and one did not receive the questionnaire). RESULTS: The main findings were that the emotional HRQL deteriorated during two years of PI-ART, while the physical HRQL remained stable. Multiple linear regression analyses showed that experience of adverse effects contributed most to the deterioration of emotional HRQL. CONCLUSION: In this sample of patients with relatively advanced state of HIV-infection, our data suggested that a negative development of physical HRQL had been interrupted by the treatment and that the emotional dimension of HRQL deteriorated during two years after start of PI-ART. Subjective experience of adverse effects made a major contribution to the decrease in emotional HRQL. The results underline the importance of including HRQL measures in the evaluation of new life prolonging therapies

Peak Bone Mass and Quantitative Ultrasound Bone Properties in Young Adulthood : A Study in the PEAK-25 Cohort of Women

Peak bone mass is normally reached in the third decade of life. Previously, in the population-based PEAK-25 cohort (n = 1061, age 25.5 ± 0.2), we demonstrated that bone mineral density in the population-based PEAK-25 cohort is comparatively high; therefore, this study aimed to determine if the calcaneus microarchitecture mirrored this. In the process, we describe normative quantitative ultrasound (QUS) values for 25-yr-old women and the relationship between QUS values and extremes of body weight. QUS variables speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness index were measured. Young adult values were based on the manufacturer-supplied QUS reference values. Analyses were performed in the cohort as a whole, and additionally, to understand the relationship between body weight and QUS values in young women, the variables were categorized into octiles for weight or body mass index (BMI) and the lowest and highest octiles were compared. In the cohort, SOS values, reflecting bone density, were higher (108 ± 18%), whereas BUA values, reflecting bone complexity, were lower (90 ± 14%) compared to the young adult reference population. SOS did not correlate with body weight or BMI. In the cohort, overall correlations between BUA weight, and BMI were small and positive (Pearson's r coefficients 0.261 and 0.197, respectively; p <0.001), although in the low-weight group, r coefficients were higher (r = 0.313 and 0.268; p <0.05). In contrast, in the high-weight group, correlation with BUA values tended to be small, negative, and nonsignificant. Correlation between QUS and dual-energy X-ray absorptiometry-measured bone mineral density was low to moderate and significant at all skeletal sites (r = 0.37-0.52). Whereas coefficients tended to be higher in the low-weight group, the reverse was apparent for the low-BMI group. In these 25-yr-old women, a comparatively high dual-energy X-ray absorptiometry-measured bone mass is offset by less complex bone structures assessed by QUS. This may have implications for later osteoporosis assessment and future fracture risk

Recent Heavy Ion Results with the ATLAS Detector at the LHC

Results are presented from the ATLAS collaboration from the 2010 LHC heavy ion run, during which nearly 10 inverse microbarns of luminosity were delivered. Soft physics results include charged particle multiplicities and collective flow. The charged particle multiplicity, which tracks initial state entropy production, increases by a factor of two relative to the top RHIC energy, with a centrality dependence very similar to that already measured at RHIC. Measurements of elliptic flow out to large transverse momentum also show similar results to what was measured at RHIC, but no significant pseudorapidity dependence. Extensions of these measurements to higher harmonics have also been made, and can be used to explain structures in the two-particle correlation functions that had long been attributed to jet-medium interactions. New hard probe measurements include single muons, jets and high $p_T$ hadrons. Single muons at high momentum are used to extract the yield of $W^{\pm}$ bosons and are found to be consistent within statistical uncertainties with binary collision scaling. Conversely, jets are found to be suppressed in central events by a factor of two relative to peripheral events, with no significant dependence on the jet energy. Fragmentation functions are also found to be the same in central and peripheral events. Finally, charged hadrons have been measured out to 30 GeV, and their centrality dependence relative to peripheral events is similar to that found for jets.Comment: 9 pages, 9 figures, proceedings for Quark Matter 2011, Annecy, France, May 23-28, 201