207 research outputs found
Spectral observations of pigment fluorescence in intermediate depth waters of the North Pacific
Vertical profiles at three stations off the California coast showed spectral differences between fluorescence at the primary fluorescence maxima (near 100 m) and the deeper maximum (near 800 m). Two broad-band excitation and several narrow or high-pass emission filters were used with an in situ fluorometer to 1500 m. Interpretation of these data suggests: (1) chlorophyll a was found throughout the water column, with intermediate depth fluorescence about one-third the intensity of that in the primary maximum; (2) phycobilin fluorescence was stronger at intermediate depths than near the surface; and (3) a pigment which fluoresces beyond 700 nm was also found in the primary fluorescence maximum
Characterization of Pfiesteria Ichthyocidal Activity
Letter to the Editor regarding article: Drgon, T., et al. 2005. Characterization of ichthyocidal activity of Pfiesteria piscicida: Dependence on the dinospore cell density. Appl. Environ. Microbiol. 71:519–52
A search for binary systems among the nearest L dwarfs
We have used the NICMOS NIC1 camera on the Hubble Space Telescope to obtain
high angular resolution images of 51 ultracool dwarfs in the immediate Solar
Neighbourhood. Nine systems are resolved as binary, with component separations
from 1.5 and 15 AU. All of the systems have components with similar
luminosities, and, consequently, high mass ratios, q > 0.8. Limiting analysis
to L dwarfs within 20 parsecs, the observed binary fraction is 12(+7/-3).
Applying Bayesian analysis to our dataset, we derive a mass-ratio distribution
that peaks strongly at unity. Modelling the semi-major axis distribution as a
logarithmic Gaussian, the best fit is centered at log(a_0) = 0.8 AU (~6.3 AU),
with a (logarithmic) width of 0.3. The current data are consistent with an
overall binary frequency of ~24%.Comment: 29 pages, 4 tables, 8 figures; accepted for publication in A
Plastid evolution: gene transfer and the maintenance of 'stolen' organelles
Many heterotrophic organisms sequester plastids from prey algae and temporarily utilize their photosynthetic capacity. A recent article in BMC Genomics reveals that the dinoflagellate Dinophysis acuminata has acquired photosynthesis-related genes by horizontal gene transfer, which might explain its ability to retain 'stolen' plastids for extended periods of time
Harmful algal blooms and eutrophication : examining linkages from selected coastal regions of the United States
Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Harmful Algae 8 (2008): 39-53, doi:10.1016/j.hal.2008.08.017.Coastal waters of the United States (U.S.) are subject to many of the major harmful algal
bloom (HAB) poisoning syndromes and impacts. These include paralytic shellfish poisoning
(PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), ciguatera
fish poisoning (CFP) and various other HAB phenomena such as fish kills, loss of submerged
vegetation, shellfish mortalities, and widespread marine mammal mortalities. Here, the
occurrences of selected HABs in a selected set of regions are described in terms of their
relationship to eutrophication, illustrating a range of responses. Evidence suggestive of
changes in the frequency, extent or magnitude of HABs in these areas is explored in the
context of the nutrient sources underlying those blooms, both natural and anthropogenic. In
some regions of the U.S., the linkages between HABs and eutrophication are clear and well
documented, whereas in others, information is limited, thereby highlighting important areas
for further research.Support was provided through the Woods Hole Center for Oceans
and Human Health (to DMA), National Science Foundation (NSF) grants OCE-9808173 and
OCE-0430724 (to DMA), OCE-0234587 (to WPC), OCE04-32479 (to MLP), OCE-0138544
(to RMK), OCE-9981617 (to PMG); National Institute of Environmental Health Sciences
(NIEHS) grants P50ES012742-01 (to DMA) and P50ES012740 (to MLP); NOAA Grants
NA96OP0099 (to DMA), NA16OP1450 (to VLT), NA96P00084 (to GAV and CAH),
NA160C2936 and NA108H-C (to RMK), NA860P0493 and NA04NOS4780241 (to PMG),
NA04NOS4780239-02 (to RMK), NA06NOS4780245 (to DWT). Support was also provided from the West Coast Center for Oceans and Human Health (to VLT and WPC), USEPA
Grant CR826792-01-0 (to GAV and CAH), and the State of Florida Grant S7701617826 (to
GAV and CAH)
Synthesis and biological evaluation of [18F]tetrafluoroborate: a PET imaging agent for thyroid disease and reporter gene imaging of the sodium/iodide symporter
Раціональність як реляційність: синтетична єдність відмінностей в трансцендентальному просторі границі
У статті висвітлюються проблеми «постсучасної» раціональності, визначальною характеристикою котрої покладається іманентна пограничність. Відношення та Іншість розглядаються як визначальні предикати раціональності, які в класичній парадигмі імплікують принципи рефлексійності, конструктивності, співмірності. Корелятами означених принципів у постструктуралістській раціональності визначаються повторність (ітеративність), фрагментарність, подвоєння, розрізняння. Конгруентність класичної та постсучасної раціональності зумовлена еквівалентністю понять трансцендентальності та пограничності. Синтетична єдність (розбіжність та зв'язок) з її специфікацією принципами пов’язання та розрізняння, визначається через медіативну функцію судження, структура якого фундується параметрами реляційності.В статье освещаются проблемы «постсовременной» рациональности, определяющей характеристикой которой полагается имманентная пограничность. Отношение и Другость рассматриваются как определяющие предикаты рациональности, которые имплицируют принципы рефлексивности, конструктивности, соразмерности в классической парадигме. Коррелятами обозначенных принципов в постструктуралистской рациональности являются повторность (итеративность), фрагментарность, удвоение, различание. Конгруэнтность классической и постсоврменной рациональности обусловлена эквивалентностью понятий трансцендентальности и пограничности. Синтетическое единств (различие и связь) с его спецификацией в позициях увязывания и различания, определяется через медиативную функцию суждения, структура которого фундируется параметрами реляционности.The paper illuminates some problems of the post-contemporary rationality that possesses the immanent borderness as its distinctive feature. The Relationality and the Anotherness are investigaled as the common predicates of rationality that implicate the “classical” principles of reflexity, constructiveness, proportionality. The main principles of the poststructuralistic rationality correlating with the classical ones are recurrence (iterativity), doubleness, fragmentariness, differance. The congruence of the classical rationality and the post-contemporary one is caused by the equivalency of the concepts “transcendentality” and “borderness”. The synthetical unity (relation between deviation and connection) with its specification by the linking and the differance principles is determined by the mediative function of the assertion that is structured by the relationality parameters
Harmful algal blooms and climate change: exploring future distribution changes
Harmful algae can cause death in fish, shellfish, marine mammals, and humans, via their toxins or from effects associated with their sheer quantity. There are many species, which cause a variety of problems around north-west Europe, and the frequency and distribution of algal blooms have altered in the recent past. Species distribution modelling was used to understand how harmful algal species may respond in the future to climate change, by considering environmental preferences and how these may shift. Most distribution studies to date use low resolution global model outputs. In this study, high resolution, downscaled shelf seas climate projections for the north-west European shelf were nested within lower resolution global projections, to understand how the distribution of harmful algae may change by the mid to end of century. Projections suggest that the habitat of most species (defined by temperature, salinity, depth, and stratification) will shift north this century, with suitability increasing in the central and northern North Sea. An increase in occurrence here might lead to more frequent detrimental blooms if wind, irradiance and nutrient levels are also suitable. Prioritizing monitoring of species in these susceptible areas could help in establishing early-warning systems for aquaculture and health protection schemes
Carbon Nanotubes in Tissue Engineering
For their peculiar features carbon nanotubes (CNTs) are emerging in many areas of nanotechnology applications. CNT-based technology has been increasingly proposed for biomedical applications, to develop biomolecule nanocarriers, bionanosensors and smart material for tissue engineering purposes. In the following chapter this latter application will be explored, describing why CNTs can be considered an ideal material able to support and boost the growth and the proliferation of many kind of tissues
Neuron-glial Interactions
Although lagging behind classical computational neuroscience, theoretical and computational approaches are beginning to emerge to characterize different aspects of neuron-glial interactions. This chapter aims to provide essential knowledge on neuron-glial interactions in the mammalian brain, leveraging on computational studies that focus on structure (anatomy) and function (physiology) of such interactions in the healthy brain. Although our understanding of the need of neuron-glial interactions in the brain is still at its infancy, being mostly based on predictions that await for experimental validation, simple general modeling arguments borrowed from control theory are introduced to support the importance of including such interactions in traditional neuron-based modeling paradigms.Junior Leader Fellowship Program by “la Caixa” Banking Foundation (LCF/BQ/LI18/11630006
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