1,270 research outputs found
Effect of decreasing oxygen tension of swimming rate of Crassostrea virginica (Gmelin, 1791) larvae
Four sizes of Crassostrea virginica Gmelin larvae (mean lengths 76.8, 118.1, 139.7 and 290.2 [Lm) were exposed to ·stepwise decreases in oxygen concentration from I 00% saturation (5 .38 mill at 22°C and 22 ppt salinity) to as low as 10% saturation and their swimming rates (net vertical movement per unit time) were recorded at each oxygen concentration. No cessation of swimming was observed and in only two conditions, that of 76.8 [Lm larvae at 10% saturation and 290.2 j.Lm larvae at 21% saturation, was swimming rate significantly lower than that of the same size larvae at full saturation
Reproductive Activity Of Oysters, Crassostrea-Virginica (Gmelin, 1791) In The James River, Virginia, During 1987-1988
Reproductive activity in oysters, Crassostrea virginica Gmelin, in the James River, Virginia, was examined for 1987 from weekly estimates for fecundity and egg viability in oysters collected from Wreck Shoal, and for 1988 from weekly estimates of fecundity, egg viability, gonad volume fraction, gonad thickness, and mean egg size in oysters collected from Horsehead Reef. Maximum and mean fecundity values from Wreck Shoal oysters were higher than from Horsehead oysters. No relationship was evident between fecundity and egg viability at Horsehead Reef. A strong temporal relationship was observed between egg viability and peak oyster settlement in the James in both years of the study as estimated by off-bottom settlement substrates. In 1987 highest viability occurred from late June through mid August with peak settlement occurring from mid June through late August. In 1988 viable eggs were recorded from late July through the end of August; major settlement occurred from early August through mid September. Fishery independent estimates of oyster population abundance on Horsehead Reef, when combined with concurrent egg production and viability data, illustrate the losses that occur during the early life history stages of oysters in this location
Effect of the 3q26-coding oncogene SEC62 as a potential prognostic marker in patients with ovarian neoplasia
With approximately 220,000 newly diagnosed cases per year, ovarian cancer is
among the most frequently occurring cancers among women and the second
leading cause of death from gynecological malignancies worldwide. About 70%
of these cancers are diagnosed in advanced stages (FIGO IIBâIV), with a 5-year
survival rate of 20â30%. Due to the poor prognosis of this disease, research has
focused on its pathogenesis and the identification of prognostic factors. One
possible approach for the identification of biological markers is the
identification of tumor entity-specific genetic âdriver mutationsâ. One such
mutation is 3q26 amplification in the tumor driver SEC62, which has been
identified as relevant to the pathogenesis of ovarian cancer. This study was
conducted to investigate the role of SEC62 in ovarian malignancies. Patients
with ovarian neoplasias (borderline tumors of the ovary and ovarian cancer) who
were treated between January 2007 and April 2019 at the Department of
Gynecology and Obstetrics, Saarland University Hospital, were included in
this retrospective study. SEC62 expression in tumor tissue samples taken
during clinical treatment was assessed immunohistochemically, with the
calculation of immunoreactivity scores according to Remmele and Stegner,
Pathologe, 1987, 8, 138â140. Correlations of SEC62 expression with the TNM
stage, histological subtype, tumor entity, and oncological outcomes
(progression-free and overall survival) were examined. The sample
comprised 167 patients (123 with ovarian cancer and 44 with borderline
tumors of the ovary) with a median age of 60 (range, 15â87) years. At the
time of diagnosis, 77 (46%) cases were FIGO stage III. All tissue slides showed
SEC62 overexpression in tumor cells and no SEC62 expression in other cells.
Median immunoreactivity scores were 8 (range, 2â12) for ovarian cancer and 9
(range, 4â12) for borderline tumors of the ovary. Patients with borderline
tumors of the ovary as well as patients with ovarian cancer and an
immunoreactive score (IRS) †9 showed an improved overall survival compared to those presenting with an IRS score >9 (p = 0.03). SEC62 seems to
be a prognostic biomarker for the overall survival of patients with ovarian
malignancies
The 3q Oncogene SEC62 Predicts Response to Neoadjuvant Chemotherapy and Regulates Tumor Cell Migration in Triple Negative Breast Cancer
In the absence of targeted treatment options, neoadjuvant chemotherapy (NACT) is applied
widely for triple-negative breast cancer (TNBC). Response to NACT is an important parameter
predictive of oncological outcomes (progression-free and overall survival). An approach to the
evaluation of predictive markers enabling therapy individualization is the identification of tumor
driver genetic mutations. This study was conducted to investigate the role of SEC62, harbored at 3q26
and identified as a driver of breast cancer pathogenesis, in TNBC. We analyzed SEC62 expression
in The Cancer Genome Atlas database, and immunohistologically investigated SEC62 expression
in pre- and post-NACT tissue samples from 64 patients with TNBC treated at the Department of
Gynecology and Obstetrics/Saarland University Hospital/Homburg between January 2010 and
December 2018 and compared the effect of SEC62 on tumor cell migration and proliferation in
functional assays. SEC62 expression dynamics correlated positively with the response to NACT
(p †0.01) and oncological outcomes (p †0.01). SEC62 expression stimulated tumor cell migration
(p †0.01). The study findings indicate that SEC62 is overexpressed in TNBC and serves as a
predictive marker for the response to NACT, a prognostic marker for oncological outcomes, and a
migration-stimulating oncogene in TNBC
Extragalactic magnetism with SOFIA (SALSA Legacy Program) -- V: First results on the magnetic field orientation of galaxies
We present the analysis of the magnetic field (-field) structure of
galaxies measured with far-infrared (FIR) and radio (3 and 6 cm) polarimetric
observations. We use the first data release of the Survey on extragALactic
magnetiSm with SOFIA (SALSA) of 14 nearby ( Mpc) galaxies with resolved (5
arcsec-18 arcsec; pc-- kpc) imaging polarimetric observations using
HAWC+/SOFIA from to \um. We compute the magnetic pitch angle
() profiles as a function of the galactrocentric radius. We introduce
a new magnetic alignment parameter () to estimate the
disordered-to-ordered -field ratio in spiral -fields. We find FIR and
radio wavelengths to not generally trace the same -field morphology in
galaxies. The profiles tend to be more ordered with galactocentric
radius in radio () than in FIR
(). For spiral galaxies, FIR -fields
are \% more turbulent than the radio -fields. For starburst galaxies,
we find that FIR polarization is a better tracer of the -fields along the
galactic outflows than radio polarization. Our results suggest that the
-fields associated with dense, dusty, turbulent star-forming regions, those
traced at FIR, are less ordered than warmer, less-dense regions, those traced
at radio, of the interstellar medium. The FIR -fields seem to be more
sensitive to the activity of the star-forming regions and the morphology of the
molecular clouds within a vertical height of few hundred pc in the disk of
spiral galaxies than the radio -fields.Comment: 26 pages, 13 figure
Gene silencing pathways found in the green alga Volvox carteri reveal insights into evolution and origins of small RNA systems in plants
Background: Volvox carteri (V. carteri) is a multicellular green alga used as model system for the evolution of multicellularity. So far, the contribution of small RNA pathways to these phenomena is not understood. Thus, we have sequenced V. carteri Argonaute 3 (VcAGO3)-associated small RNAs from different developmental stages. Results: Using this functional approach, we define the Volvox microRNA (miRNA) repertoire and show that miRNAs are not conserved in the closely related unicellular alga Chlamydomonas reinhardtii. Furthermore, we find that miRNAs are differentially expressed during different life stages of V. carteri. In addition to miRNAs, transposon-associated small RNAs or phased siRNA loci, which are common in higher land plants, are highly abundant in Volvox as well. Transposons not only give rise to miRNAs and other small RNAs, they are also targets of small RNAs. Conclusion: Our analyses reveal a surprisingly complex small RNA network in Volvox as elaborate as in higher land plants. At least the identified VcAGO3-associated miRNAs are not conserved in C. reinhardtii suggesting fast evolution of small RNA systems. Thus, distinct small RNAs may contribute to multicellularity and also division of labor in reproductive and somatic cells
Functionalized Fullerene for Inhibition of SARS-CoV-2 Variants
As virus outbreaks continue to pose a challenge, a nonspecific viral inhibitor can provide significant benefits, especially against respiratory viruses. Polyglycerol sulfates recently emerge as promising agents that mediate interactions between cells and viruses through electrostatics, leading to virus inhibition. Similarly, hydrophobic C60 fullerene can prevent virus infection via interactions with hydrophobic cavities of surface proteins. Here, two strategies are combined to inhibit infection of SARS-CoV-2 variants in vitro. Effective inhibitory concentrations in the millimolar range highlight the significance of bare fullerene's hydrophobic moiety and electrostatic interactions of polysulfates with surface proteins of SARS-CoV-2. Furthermore, microscale thermophoresis measurements support that fullerene linear polyglycerol sulfates interact with the SARS-CoV-2 virus via its spike protein, and highlight importance of electrostatic interactions within it. All-atom molecular dynamics simulations reveal that the fullerene binding site is situated close to the receptor binding domain, within 4 nm of polyglycerol sulfate binding sites, feasibly allowing both portions of the material to interact simultaneously
Extragalactic Magnetism with SOFIA (SALSA Legacy Program). VII. A tomographic view of far infrared and radio polarimetric observations through MHD simulations of galaxies
The structure of magnetic fields in galaxies remains poorly constrained,
despite the importance of magnetism in the evolution of galaxies. Radio
synchrotron and far-infrared dust polarization (FIR) polarimetric observations
are the best methods to measure galactic scale properties of magnetic fields in
galaxies beyond the Milky Way. We use synthetic polarimetric observations of a
simulated galaxy to identify and quantify the regions, scales, and interstellar
medium (ISM) phases probed at FIR and radio wavelengths. Our studied suite of
magnetohydrodynamical cosmological zoom-in simulations features
high-resolutions (10 pc full-cell size) and multiple magnetization models. Our
synthetic observations have a striking resemblance to those of observed
galaxies. We find that the total and polarized radio emission extends to
approximately double the altitude above the galactic disk (half-intensity disk
thickness of kpc)
relative to the FIR total and polarized emission that are concentrated in the
disk midplane ( kpc).
Radio emission traces magnetic fields at scales of pc, whereas
FIR emission probes magnetic fields at the smallest scales of our simulations.
These scales are comparable to our spatial resolution and well below the
spatial resolution ( pc) of existing FIR polarimetric measurements.
Finally, we confirm that synchrotron emission traces a combination of the warm
neutral and cold neutral gas phases, whereas FIR emission follows the densest
gas in the cold neutral phase in the simulation. These results are independent
of the ISM magnetic field strength. The complementarity we measure between
radio and FIR wavelengths motivates future multiwavelength polarimetric
observations to advance our knowledge of extragalactic magnetism.Comment: Submitted to ApJ. 32 pages, 15 figure
Dating of the hominid (homo neanderthalensis) remains accumulation from el sidrón cave (piloña, asturias, north spain): An example of a multi-methodological approach to the dating of upper pleistocene sites
The age of Neanderthal remains and associated sediments from El SidrĂłn cave has been obtained through different dating methods (14CAMS, U/TH, OSL, ESR and AAR) and samples (charcoal debris, bone, tooth dentine, stalagmitic flowstone, carbonate-rich sedi
Extragalactic Magnetism with SOFIA (SALSA Legacy Program). VII. A Tomographic View of Far-infrared and Radio Polarimetric Observations through MHD Simulations of Galaxies
The structure of magnetic fields in galaxies remains poorly constrained, despite the importance of magnetism in the evolution of galaxies. Radio synchrotron and far-infrared (FIR) polarization and polarimetric observations are the best methods to measure galactic scale properties of magnetic fields in galaxies beyond the Milky Way. We use synthetic polarimetric observations of a simulated galaxy to identify and quantify the regions, scales, and interstellar medium (ISM) phases probed at FIR and radio wavelengths. Our studied suite of magnetohydrodynamical cosmological zoom-in simulations features high-resolutions (10 pc full-cell size) and multiple magnetization models. Our synthetic observations have a striking resemblance to those of observed galaxies. We find that the total and polarized radio emission extends to approximately double the altitude above the galactic disk (half-intensity disk thickness of h I radio ⌠h PI radio = 0.23 ± 0.03 kpc) relative to the total FIR and polarized emission that are concentrated in the disk midplane (h I FIR ⌠h PI FIR = 0.11 ± 0.01 kpc). Radio emission traces magnetic fields at scales of âł300 pc, whereas FIR emission probes magnetic fields at the smallest scales of our simulations. These scales are comparable to our spatial resolution and well below the spatial resolution (<300 pc) of existing FIR polarimetric measurements. Finally, we confirm that synchrotron emission traces a combination of the warm neutral and cold neutral gas phases, whereas FIR emission follows the densest gas in the cold neutral phase in the simulation. These results are independent of the ISM magnetic field strength. The complementarity we measure between radio and FIR wavelengths motivates future multiwavelength polarimetric observations to advance our knowledge of extragalactic magnetism
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