137 research outputs found
Annual phytoplankton succession results from niche-environment interaction
Annual plankton succession has been investigated for many decades and hypotheses ranging from abiotic to biotic mechanisms have been proposed to explain this recurrent pattern. Here, using data collected by the Continuous Plankton Recorder (CPR) survey and models originating from the MacroEcological Theory on the Arrangement of Life (METAL), we investigate annual phytoplankton succession in the North Sea at a species level. Our results show that this
phenomenon can be well predicted by models combining photosynthetically active radiation, temperature and macro-nutrients. Our findings suggest that annual phytoplankton succession, at community level, originates from the interaction between species ecological niche and annual
environmental fluctuations. We discuss our results in the context of traditional hypotheses formulated to explain this recurrent pattern in the marine field, including those on the initiation, the development and the termination of a typical extratropical spring bloom
PIONIER: a visitor instrument for the VLTI
PIONIER is a 4-telescope visitor instrument for the VLTI, planned to see its
first fringes in 2010. It combines four ATs or four UTs using a pairwise ABCD
integrated optics combiner that can also be used in scanning mode. It provides
low spectral resolution in H and K band. PIONIER is designed for imaging with a
specific emphasis on fast fringe recording to allow closure-phases and
visibilities to be precisely measured. In this work we provide the detailed
description of the instrument and present its updated status.Comment: Proceedings of SPIE conference Optical and Infrared Interferometry II
(Conference 7734) San Diego 201
Concept and optical design of the cross-disperser module for CRIRES
This is the peer reviewed version of the following article: Oliva, Ernesto, A. Tozzi, D. Ferruzzi, L. Origlia, A. Hatzes, R. Follert, T. Loewinger et al. "Concept and optical design of the cross-disperser module for CRIRES+." In SPIE Astronomical Telescopes+ Instrumentation, pp. 91477R-91477R. International Society for Optics and Photonics, 2014, which has been published in final form at 10.1117/12.2054381
ESPRESSO: The next European exoplanet hunter
The acronym ESPRESSO stems for Echelle SPectrograph for Rocky Exoplanets and
Stable Spectroscopic Observations; this instrument will be the next VLT high
resolution spectrograph. The spectrograph will be installed at the
Combined-Coud\'e Laboratory of the VLT and linked to the four 8.2 m Unit
Telescopes (UT) through four optical Coud\'e trains. ESPRESSO will combine
efficiency and extreme spectroscopic precision. ESPRESSO is foreseen to achieve
a gain of two magnitudes with respect to its predecessor HARPS, and to improve
the instrumental radial-velocity precision to reach the 10 cm/s level. It can
be operated either with a single UT or with up to four UTs, enabling an
additional gain in the latter mode. The incoherent combination of four
telescopes and the extreme precision requirements called for many innovative
design solutions while ensuring the technical heritage of the successful HARPS
experience. ESPRESSO will allow to explore new frontiers in most domains of
astrophysics that require precision and sensitivity. The main scientific
drivers are the search and characterization of rocky exoplanets in the
habitable zone of quiet, nearby G to M-dwarfs and the analysis of the
variability of fundamental physical constants. The project passed the final
design review in May 2013 and entered the manufacturing phase. ESPRESSO will be
installed at the Paranal Observatory in 2016 and its operation is planned to
start by the end of the same year.Comment: 12 pages, figures included, accepted for publication in Astron. Nach
Automated techniques to follow the spatial distribution of <i>Phaeocystis globosa</i> and diatoms spring blooms in the Channel and North Sea
Results from campaign in the Channel-North Sea and Belgian Coastal Zone – RV <i>Simon Stevin</i>
Objective: The purpose of this study is to determine the relationship between iron storage and overall well-being in female college athletes. This was done to determine a cost-effective screening method for iron deficiency.
Design: Retrospective Cohort
Subjects and Settings: All subjects were 117 Division I Female Athletes at James Madison University. Subjects were ages 17-22 from different teams(Cross Country, Track & Field, Basketball, Field Hockey, Lacrosse, Volleyball, Golf, Swimming & Diving, Soccer, and Softball). We excluded 1 subject based on a medical diagnosis. Some subjects had more than one data entry based on their year at JMU.
Main Outcome Measure: Data was recorded for individuals who have in the past received blood draws testing for ferritin levels and have completed a Henriques 10-Item Well-being Questionnaire(H10WB) within a year of the blood draw.
Results: Correlations resulted in no significant relationship between ferritin levels and H10WB total scores with a 1-tailed p-value of .071. There was some significance seen with responses to individual questions within the questionnaire and ferritin(p=.02 and p= .032).
Conclusion: Since there was very little significance found for this relationship we can conclude that the symptoms of changes in athlete’s overall well-being status are not present in those with iron deficiency. Research does support a relationship between these symptoms with iron deficiency anemia therefore, these results could represent that those symptoms are not experienced with iron deficiency. This suggests the increased need to find a screening tool for healthcare providers to use to determine an iron deficiency without requiring blood draws from everyone. This would allow professionals to determine this deficiency before it becomes anemia and these symptoms develop
Addressing the timing and extension of phytoplankton bloom through the eastern Channel - southern North Sea continuum in spring: an automated approach
Results from campaign in the Channel-North Sea and Belgian Coastal Zone – RV <i>Simon Stevin</i>
An overview of the mid-infrared spectro-interferometer MATISSE: science, concept, and current status
MATISSE is the second-generation mid-infrared spectrograph and imager for the
Very Large Telescope Interferometer (VLTI) at Paranal. This new interferometric
instrument will allow significant advances by opening new avenues in various
fundamental research fields: studying the planet-forming region of disks around
young stellar objects, understanding the surface structures and mass loss
phenomena affecting evolved stars, and probing the environments of black holes
in active galactic nuclei. As a first breakthrough, MATISSE will enlarge the
spectral domain of current optical interferometers by offering the L and M
bands in addition to the N band. This will open a wide wavelength domain,
ranging from 2.8 to 13 um, exploring angular scales as small as 3 mas (L band)
/ 10 mas (N band). As a second breakthrough, MATISSE will allow mid-infrared
imaging - closure-phase aperture-synthesis imaging - with up to four Unit
Telescopes (UT) or Auxiliary Telescopes (AT) of the VLTI. Moreover, MATISSE
will offer a spectral resolution range from R ~ 30 to R ~ 5000. Here, we
present one of the main science objectives, the study of protoplanetary disks,
that has driven the instrument design and motivated several VLTI upgrades
(GRA4MAT and NAOMI). We introduce the physical concept of MATISSE including a
description of the signal on the detectors and an evaluation of the expected
performances. We also discuss the current status of the MATISSE instrument,
which is entering its testing phase, and the foreseen schedule for the next two
years that will lead to the first light at Paranal.Comment: SPIE Astronomical Telescopes and Instrumentation conference, June
2016, 11 pages, 6 Figure
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