Tropical seagrass-associated macroalgae distributions and trends relative to water quality

Tropical coastal marine ecosystems including mangroves, seagrass beds and coral reef communities are undergoing intense degradation in response to natural and human disturbances, therefore, understanding the causes and mechanisms present challenges for scientist and managers. In order to protect our marine resources, determining the effects of nutrient loads on these coastal systems has become a key management goal. Data from monitoring programs were used to detect trends of macroalgae abundances and develop correlations with nutrient availability, as well as forecast potential responses of the communities monitored. Using eight years of data (1996–2003) from complementary but independent monitoring programs in seagrass beds and water quality of the Florida Keys National Marine Sanctuary (FKNMS), we: (1) described the distribution and abundance of macroalgae groups; (2) analyzed the status and spatiotemporal trends of macroalgae groups; and (3) explored the connection between water quality and the macroalgae distribution in the FKNMS. In the seagrass beds of the FKNMS calcareous green algae were the dominant macroalgae group followed by the red group; brown and calcareous red algae were present but in lower abundance. Spatiotemporal patterns of the macroalgae groups were analyzed with a non-linear regression model of the abundance data. For the period of record, all macroalgae groups increased in abundance (Abi) at most sites, with calcareous green algae increasing the most. Calcareous green algae and red algae exhibited seasonal pattern with peak abundances (Φi) mainly in summer for calcareous green and mainly in winter for red. Macroalgae Abi and long-term trend (mi) were correlated in a distinctive way with water quality parameters. Both the Abi and mi of calcareous green algae had positive correlations with NO3−, NO2−, total nitrogen (TN) and total organic carbon (TOC). Red algae Abi had a positive correlation with NO2−, TN, total phosphorus and TOC, and the mi in red algae was positively correlated with N:P. In contrast brown and calcareous red algae Abi had negative correlations with N:P. These results suggest that calcareous green algae and red algae are responding mainly to increases in N availability, a process that is happening in inshore sites. A combination of spatially variable factors such as local current patterns, nutrient sources, and habitat characteristics result in a complex array of the macroalgae community in the seagrass beds of the FKNMS

Effects of hypophyseal or thymic allograft on thymus development in partially decerebrated chicken embryos: expression of PCNA and CD3 markers

Changes in chicken embryo thymus after partial decerebration (including the hypophysis) and after hypophyseal or thymic allograft were investigated. Chicken embryos were partially decerebrated at 36–40 h of incubation and on day 12 received a hypophysis or a thymus allograft from 18-day-old donor embryos. The thymuses of normal, sham-operated and partially decerebrate embryos were collected on day 12 and 18. The thymuses of the grafted embryos were collected on day 18. The samples were examined with histological method and tested for the anti-PCNA and anti-CD3 immune-reactions. After partial decerebration, the thymic cortical and medullary compartments diminished markedly in size. Anti-PCNA and anti-CD3 revealed a reduced immunereaction, verified also by statistical analysis. In hypophyseal or grafted embryos, the thymic morphological compartments improved, the anti-PCNA and anti-CD3 immune-reactions recovered much better after the thymic graft, probably due to the thymic growth factors and also by an emigration of thymocytes from the same grafted thymus

SiPM technology applied to radiation sensor development

The Silicon Photo-Multiplier (SiPM) being yet in its infancy, a full protocol for the sensor characterization has been developed and implemented at the Physics Department of Universita\u2019 dell\u2019Insubria. Sensors from different producers have been analyzed and compared, in view of the integration in the instruments for radiation detection. Exemplary illustrations are reported here, together with the first results on real-time dosimetry in mammography

Annihilation of low energy antiprotons in silicon

The goal of the AE$\mathrm{\bar{g}}$IS experiment at the Antiproton Decelerator (AD) at CERN, is to measure directly the Earth's gravitational acceleration on antimatter. To achieve this goal, the AE$\mathrm{\bar{g}}$IS collaboration will produce a pulsed, cold (100 mK) antihydrogen beam with a velocity of a few 100 m/s and measure the magnitude of the vertical deflection of the beam from a straight path. The final position of the falling antihydrogen will be detected by a position sensitive detector. This detector will consist of an active silicon part, where the annihilations take place, followed by an emulsion part. Together, they allow to achieve 1$$ precision on the measurement of $\bar{g}$ with about 600 reconstructed and time tagged annihilations. We present here, to the best of our knowledge, the first direct measurement of antiproton annihilation in a segmented silicon sensor, the first step towards designing a position sensitive silicon detector for the AE$\mathrm{\bar{g}}$IS experiment. We also present a first comparison with Monte Carlo simulations (GEANT4) for antiproton energies below 5 MeVComment: 21 pages in total, 29 figures, 3 table

GRIPS - Gamma-Ray Imaging, Polarimetry and Spectroscopy

We propose to perform a continuously scanning all-sky survey from 200 keV to 80 MeV achieving a sensitivity which is better by a factor of 40 or more compared to the previous missions in this energy range. The Gamma-Ray Imaging, Polarimetry and Spectroscopy (GRIPS) mission addresses fundamental questions in ESA's Cosmic Vision plan. Among the major themes of the strategic plan, GRIPS has its focus on the evolving, violent Universe, exploring a unique energy window. We propose to investigate $\gamma$-ray bursts and blazars, the mechanisms behind supernova explosions, nucleosynthesis and spallation, the enigmatic origin of positrons in our Galaxy, and the nature of radiation processes and particle acceleration in extreme cosmic sources including pulsars and magnetars. The natural energy scale for these non-thermal processes is of the order of MeV. Although they can be partially and indirectly studied using other methods, only the proposed GRIPS measurements will provide direct access to their primary photons. GRIPS will be a driver for the study of transient sources in the era of neutrino and gravitational wave observatories such as IceCUBE and LISA, establishing a new type of diagnostics in relativistic and nuclear astrophysics. This will support extrapolations to investigate star formation, galaxy evolution, and black hole formation at high redshifts.Comment: to appear in Exp. Astron., special vol. on M3-Call of ESA's Cosmic Vision 2010; 25 p., 25 figs; see also www.grips-mission.e

The energy dependence of flow in Ni induced collisions from 400 to 1970A MeV

We study the energy dependence of collective (hydrodynamic-like) nuclear matter flow in 400-1970 A MeV Ni+Au and 1000-1970 A MeV Ni+Cu reactions. The flow increases with energy, reaches a maximum, and then gradually decreases at higher energies. A way of comparing the energy dependence of flow values for different projectile-target mass combinations is introduced, which demonstrates a common scaling behaviour among flow values from different systems.Comment: 12 pages, 3 figures. Submitted to Physical Review Letter

Radial Flow in Au+Au Collisions at E=0.25-1.15 A GeV

A systematic study of energy spectra for light particles emitted at midrapidity from Au+Au collisions at E=0.25-1.15 A GeV reveals a significant non-thermal component consistent with a collective radial flow. This component is evaluated as a function of bombarding energy and event centrality. Comparisons to Quantum Molecular Dynamics (QMD) and Boltzmann-Uehling-Uhlenbeck (BUU) models are made for different equations of state.Comment: 10 pages of text and 4 figures (all ps files in a uuencoded package)

Accumulative Difference Image Protocol for Particle Tracking in Fluorescence Microscopy Tested in Mouse Lymphonodes

The basic research in cell biology and in medical sciences makes large use of imaging tools mainly based on confocal fluorescence and, more recently, on non-linear excitation microscopy. Substantially the aim is the recognition of selected targets in the image and their tracking in time. We have developed a particle tracking algorithm optimized for low signal/noise images with a minimum set of requirements on the target size and with no a priori knowledge of the type of motion. The image segmentation, based on a combination of size sensitive filters, does not rely on edge detection and is tailored for targets acquired at low resolution as in most of the in-vivo studies. The particle tracking is performed by building, from a stack of Accumulative Difference Images, a single 2D image in which the motion of the whole set of the particles is coded in time by a color level. This algorithm, tested here on solid-lipid nanoparticles diffusing within cells and on lymphocytes diffusing in lymphonodes, appears to be particularly useful for the cellular and the in-vivo microscopy image processing in which few a priori assumption on the type, the extent and the variability of particle motions, can be done

Cardiovascular disease after childhood acute lymphoblastic leukaemia: a cohort study.

BACKGROUND AND AIMS Cardiovascular diseases (CVD) increase late morbidity and mortality in survivors of acute lymphoblastic leukaemia (ALL). We compared the risk of CVD in ALL survivors to siblings, examined time trends, quantified treatment-related risks, and investigated whether risk extends beyond patients treated with anthracyclines and chest radiotherapy. METHODS The Swiss Childhood Cancer Survivor Study assessed CVD by patient questionnaire in 5-year ALL survivors diagnosed between 1976 and 2005 and their siblings. Participants were asked whether a physician had ever told them that they had hypertension, arrhythmia, heart failure, myocardial infarction, angina pectoris, stroke, thrombosis or valvular problems. We investigated treatment-related risk factors for CVD using multivariable logistic regression, adjusting for demographic and socioeconomic factors, BMI, smoking, diabetes mellitus, alcohol consumption and physical activity. RESULTS We contacted 707 survivors and 1299 siblings, 511 (72%) and 709 (55%) of whom responded, respectively. Survivors had a higher risk of developing CVD than siblings (odds ratio [OR] 1.9, 95% confidence interval 1.3–2.8), in particular heart failure (OR 13.9, 1.8–107.4). Compared to patients treated 1976–85, the risk of CVD was 1.4 (0.7–2.8) for those treated 1985–1994 and 1.5 (0.6–3.7) for those treated 1995–2005. The overall CVD risks after anthracycline treatment (OR 3.1, 2.0–4.7), haematopoietic stem cell transplantation (OR 8.0, 2.4–26.9) or relapse (OR 4.1, 1.9–8.8) were increased compared to those of siblings, while the CVD risks of survivors treated without anthracycline or chest radiotherapy were similar (OR 1.0; 0.5–2.0). CONCLUSIONS Despite attempts to reduce cardiotoxicity in childhood cancer treatment, CVD risks in ALL survivors treated more recently do not seem to have declined