354 research outputs found
Effects Of 2 Bloom-Forming Dinoflagellates, Prorocentrum-Minimum And Gyrodinium-Uncatenum, On The Growth And Survival Of The Eastern Oyster, Crassostrea-Virginica (Gmelin 1791)
Laboratory experiments were conducted to investigate the effects of the dinoflagellates Prorocentrum minimum and Gyrodinium uncatenum on the growth and survival of juvenile eastern oysters, Crassostrea virginica. In separate experiments lasting 30 d and 18 d for P. minimum and G. uncatenum, respectively, the dinoflagellates were offered to the oysters in both unialgal and mixed diets (with the diatom Thalassiosira weisflogii). Eight diets were used in each experiment: (i) the dinoflagellate at bloom density, (ii) the dinoflagellate at 33% bloom density, (iii) the dinoflagellate at 5% bloom density, (iv-vi) the diatom at the above densities, (vii) 50% dinoflagellate bloom density + 50% diatom bloom density, and (viii) 5% dinoflagellate bloom density + 95% diatom bloom density. P. minimum at bloom density resulted in 100% mortality of juvenile oysters within 14 d and at 33% bloom density it resulted in 43% mortality within 22 d. Diets containing 5% P. minimum density did not cause mortality and supported good shell growth. No mortality was observed among oysters fed G. uncatenum and diets which included this dinoflagellate resulted in significantly greater growth than diets of the diatom T. weisflogii
Sixfold improved single particle measurement of the magnetic moment of the antiproton
Our current understanding of the Universe comes, among others, from particle physics and cosmology. In particle physics an almost perfect symmetry between matter and antimatter exists. On cosmological scales, however, a striking matter/antimatter imbalance is observed. This contradiction inspires comparisons of the fundamental properties of particles and antiparticles with high precision. Here we report on a measurement of the g-factor of the antiproton with a fractional precision of 0.8 parts per million at 95% confidence level. Our value /2=2.7928465(23) outperforms the previous best measurement by a factor of 6. The result is consistent with our proton g-factor measurement gp/2=2.792847350(9), and therefore agrees with the fundamental charge, parity, time (CPT) invariance of the Standard Model of particle physics. Additionally, our result improves coefficients of the standard model extension which discusses the sensitivity of experiments with respect to CPT violation by up to a factor of 20.EU/ERC/290870-MEFUCOMax-Planck SocietyHelmholtz-GemeinschaftRIKEN Initiative Research Unit ProgramRIKEN President FundingRIKEN Pioneering Project FundingRIKEN FPR FundingRIKEN JRA ProgramMEXT/24000008Max-Planck SocietyEU/ERC Advanced Grant/290870-MEFUCOHelmholtz-GemeinschaftCERN-fellowship program
Unsupervised Domain Transfer with Conditional Invertible Neural Networks
Synthetic medical image generation has evolved as a key technique for neural
network training and validation. A core challenge, however, remains in the
domain gap between simulations and real data. While deep learning-based domain
transfer using Cycle Generative Adversarial Networks and similar architectures
has led to substantial progress in the field, there are use cases in which
state-of-the-art approaches still fail to generate training images that produce
convincing results on relevant downstream tasks. Here, we address this issue
with a domain transfer approach based on conditional invertible neural networks
(cINNs). As a particular advantage, our method inherently guarantees cycle
consistency through its invertible architecture, and network training can
efficiently be conducted with maximum likelihood training. To showcase our
method's generic applicability, we apply it to two spectral imaging modalities
at different scales, namely hyperspectral imaging (pixel-level) and
photoacoustic tomography (image-level). According to comprehensive experiments,
our method enables the generation of realistic spectral data and outperforms
the state of the art on two downstream classification tasks (binary and
multi-class). cINN-based domain transfer could thus evolve as an important
method for realistic synthetic data generation in the field of spectral imaging
and beyond
Improved limit on the directly measured antiproton lifetime
Continuous monitoring of a cloud of antiprotons stored in a Penning trap for 405 days enables us to set an improved limit on the directly measured antiproton lifetime. From our measurements we extract a storage time of 3.15x108 equivalent antiproton-seconds, resulting in a lower lifetime limit of Tp > 10.2,a with a confidence level of 68%. This result improves the limit on charge-parity-time violation in antiproton decays based on direct observation by a factor of 7
The influence of anthropogenic nitrogen loading and meteorological conditions on the dynamics and toxicity of Alexandrium fundyense blooms in a New York (USA) estuary
Author Posting. © The Author(s), 2010. 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 9 (2010): 402-412, doi:10.1016/j.hal.2010.02.003.The goal of this two-year study was to explore the role of nutrients and
climatic conditions in promoting reoccurring Alexandrium fundyense blooms in the
Northport-Huntington Bay complex, NY, USA. A bloom in 2007 was short and small (3
weeks, 103 cells L-1 maximal density) compared to 2008 when the A. fundyense bloom,
which persisted for six weeks, achieved cell densities >106 cells L-1 and water column
saxitoxin concentrations >2.4 x 104 pmol STX eq. L-1. During the 2008 bloom, both
deployed mussels (used as indicator species) and wild soft shell clams became highly
toxic (1,400 and 600μg STX eq./100g shellfish tissue, respectively) resulting in the
closure of shellfish beds. The densities of benthic A. fundyense cysts at the onset of this
bloom were four orders of magnitude lower than levels needed to account for observed
cell densities, indicating in situ growth of vegetative cells was responsible for elevated
bloom densities. Experimental enrichment of bloom water with nitrogenous compounds,
particularly ammonium, significantly increased A. fundyense densities and particulate
saxitoxin concentrations relative to unamended control treatments. The δ15N signatures
(12 to 23‰) of particulate organic matter (POM) during blooms were similar to those of
sewage (10 to 30‰) and both toxin and A. fundyense densities were significantly
correlated with POM δ15N (p < 0.001). These findings suggest A. fundyense growth was
supported by a source of wastewater such as the sewage treatment plant which discharges
into Northport Harbor. Warmer than average atmospheric temperatures in the late winter
and spring of 2008 and a cooler May contributed to an extended period of water column
temperatures optimal for A. fundyense growth (12 – 20ºC), and thus may have also
contributed toward the larger and longer bloom in 2008. Together this evidence suggests
sewage-derived N loading and above average spring temperatures can promote intense
and toxic A. fundyense blooms in estuaries.This work was supported by a grant from EPA’s Long Island Sound Study, New York
Sea Grant, and the New York State Department of Environmental Conservation (to CJG)
and from the NOAA Sea Grant Program (Grant No. NA06OAR4170021 (R/B-177)) to
DMA
An assigned responsibility system for robotic teleoperation control
This paper proposes an architecture that explores a gap in the spectrum of existing strategies for robot control mode switching in adjustable autonomy. In situations where the environment is reasonably known and/or predictable, pre-planning these control changes could relieve robot operators of the additional task of deciding when and how to switch. Such a strategy provides a clear division of labour between the automation and the human operator(s) before the job even begins, allowing for individual responsibilities to be known ahead of time, limiting confusion and allowing rest breaks to be planned. Assigned Responsibility is a new form of adjustable autonomy-based teleoperation that allows the selective inclusion of automated control elements at key stages of a robot operation plan’s execution. Progression through these stages is controlled by automatic goal accomplishment tracking. An implementation is evaluated through engineering tests and a usability study, demonstrating the viability of this approach and offering insight into its potential applications
A novel de novo BRCA1 mutation in a Chinese woman with early onset breast cancer
Germline mutations in the two breast cancer susceptibility genes, BRCA1 and BRCA2 account for a significant portion of hereditary breast/ovarian cancer. De novo mutations such as multiple exon deletion are rarely occurred in BRCA1 and BRCA2. During our mutation screening for BRCA1/2 genes to Chinese women with risk factors for hereditary breast/ovarian cancer, we identified a novel germline mutation, consisting of a deletion from exons 1 to 12 in BRCA1 gene, in a patient diagnosed with early onset triple negative breast cancer with no family history of cancer. None of her parents carried the mutation and molecular analysis showed that this novel de novo germline mutation resulted in down-regulation of BRCA1 gene expression
Rapid screening for chromosomal aneuploidies using array-MLPA
<p>Abstract</p> <p>Background</p> <p>Chromosome abnormalities, especially trisomy of chromosome 21, 13, or 18 as well as sex chromosome aneuploidy, are a well-established cause of pregnancy loss. Cultured cell karyotype analysis and FISH have been considered reliable detectors of fetal abnormality. However, results are usually not available for 3-4 days or more. Multiplex ligation-dependent probe amplification (MLPA) has emerged as an alternative rapid technique for detection of chromosome aneuploidies. However, conventional MLPA does not allow for relative quantification of more than 50 different target sequences in one reaction and does not detect mosaic trisomy. A multiplexed MLPA with more sensitive detection would be useful for fetal genetic screening.</p> <p>Methods</p> <p>We developed a method of array-based MLPA to rapidly screen for common aneuploidies. We designed 116 universal tag-probes covering chromosomes 13, 18, 21, X, and Y, and 8 control autosomal genes. We performed MLPA and hybridized the products on a 4-well flow-through microarray system. We determined chromosome copy numbers by analyzing the relative signals of the chromosome-specific probes.</p> <p>Results</p> <p>In a blind study of 161 peripheral blood and 12 amniotic fluid samples previously karyotyped, 169 of 173 (97.7%) including all the amniotic fluid samples were correctly identified by array-MLPA. Furthermore, we detected two chromosome X monosomy mosaic cases in which the mosaism rates estimated by array-MLPA were basically consistent with the results from karyotyping. Additionally, we identified five Y chromosome abnormalities in which G-banding could not distinguish their origins for four of the five cases.</p> <p>Conclusions</p> <p>Our study demonstrates the successful application and strong potential of array-MLPA in clinical diagnosis and prenatal testing for rapid and sensitive chromosomal aneuploidy screening. Furthermore, we have developed a simple and rapid procedure for screening copy numbers on chromosomes 13, 18, 21, X, and Y using array-MLPA.</p
The relationships between West Nile and Kunjin viruses.
Until recently, West Nile (WN) and Kunjin (KUN) viruses were classified as distinct types in the Flavivirus genus. However, genetic and antigenic studies on isolates of these two viruses indicate that the relationship between them is more complex. To better define this relationship, we performed sequence analyses on 32 isolates of KUN virus and 28 isolates of WN virus from different geographic areas, including a WN isolate from the recent outbreak in New York. Sequence comparisons showed that the KUN virus isolates from Australia were tightly grouped but that the WN virus isolates exhibited substantial divergence and could be differentiated into four distinct groups. KUN virus isolates from Australia were antigenically homologous and distinct from the WN isolates and a Malaysian KUN virus. Our results suggest that KUN and WN viruses comprise a group of closely related viruses that can be differentiated into subgroups on the basis of genetic and antigenic analyses
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