1,429 research outputs found
Status and Relative Abundance of Alabama Shad, \u3ci\u3eAlosa alabamae\u3c/i\u3e, in Alabama
Alabama Shad, Alosa alabamae, an anadromous fish found historically from the Mississippi River basin eastward to the Suwanee River, has experienced population declines and even extirpation in some States. In Alabama, A. alabamae have been found in rivers of the Mobile River basin and Conecuh, Yellow, and Choctawhatchee rivers in the coastal Gulf Plain. We report on our directed and targeted efforts to assess the current status and relative abundance of A. alabamae in Alabama and compare our results to past A. alabamae surveys in Alabama. We completed 52 sampling trips and expended 129.5 hours of boat-electrofishing effort targeting A. alabamae. Sampling was conducted during the spring to coincide with the spring-spawning migration at historical sites and sites conducive for the collection of A. alabamae. No A. alabamae was collected from the Mobile River basin (i.e., Alabama and Tombigbee rivers) and only one A. alabamae was collected from the Conecuh River. We collected seven A. alabamae in 2011 and three in 2018 from the Choctawhatchee River. For the Choctawhatchee River population, our results indicated a precipitous decline in abundance by 71% and 98% from 1999/2000 to 2011 and 2018, respectively. In addition, our results support the extirpation of A. alabamae from the Mobile River basin and a severely depressed population in the Conecuh River. Although A. alabamae was recently denied listing under the Endangered Species Act by the National Marine Fisheries Service due to lack of apparent range-wide extinction, our results indicate what was once considered the second largest population of A. alabamae from the Choctawhatchee River is on the verge of extirpation. Alosa alabamae could become extirpated from Alabama in the near future, which is a significant portion of its range
Electrochemical Monitoring Of Electrogalvanizing Solutions
The corrosion resistance of steel is vastly improved when a zinc cathodic protective layer is applied. In recent years there has been renewed interest in producing this galvanized coating electrolytically. As with many deposition processes, the control of the operating parameters is very important in order to produce good quality zinc coatings. The homogeneity, ductility and smoothness of the zinc layer are critical. These factors are usually influenced by the electrochemical nature of the solution and organic additives are often used to assist in control. Studies on the polarization behavior of solutions for electro galvanizing electrolytes were made. Cyclic voltammetry techniques were used to develop methods which might be applicable in monitoring the active organic content of liquor ice in solution. The morphologies and orientations of the zinc were studied using SEM and X-ray diffraction techniques. © 1986 Chapman and Hall Ltd
Metabolic enhancers supporting 1-carbon cycle affect sperm functionality: an in vitro comparative study
The sperm plasma membrane is a sensitive target to oxidative stress. The most representative reactive oxygen species (ROS) scavengers in the genital tract, hypotaurine and glutathione, require, for their synthesis, cysteine whose availability is associated with the 1-carbon cycle (1-CC). Human, bovine and ascidian spermatozoa were incubated with compounds supporting the 1-CC (Vitamin B6, Methylcobalamin, 5 Methyl Tetrahydrofolate, Zinc Bisglycinate and N-acetyl-cysteine) (TRT) and compared to the effects induced solely by N-acetyl-cysteine (NAC). In control groups (CNTRL), spermatozoa were incubated with medium alone. After 90 and 180 minutes of incubation, the mitochondrial membrane potential (ΔΨM) in TRT and NAC was significantly (P < 0.01) higher than in CNTRL. At H2DCFDA evaluation, ROS production differed between species whereas, at 2-OH Ethidium, it significantly decreased in bovine TRT group. Intracellular pH (pHi) did not significantly vary in relation to treatment. In ascidian spermatozoa, the NAC supplementation decreased external pH, which in turn brought to a pHi lowering. Buffering seawater with NaHCO3 reversed the beneficial effects of N-acetyl-cysteine supplementation. In conclusion, both fully supporting the 1-CC and treatment with N-acetyl-cysteine alone improved kinetics, ΔΨM and ROS production in mammalian sperm demonstrating for the first time the direct in vitro effects of these compounds on sperm functionality
Prevention of Chemotherapy-Induced Anemia and Thrombocytopenia by Constant Administration of Stem Cell Factor
Purpose: Chemotherapy-induced apoptosis of immature hematopoietic cells is a major cause of anemia and thrombocytopenia in cancer patients. Although hematopoietic growth factors such as erythropoietin and colony-stimulating factors cannot prevent the occurrence of drug-induced myelosuppression, stem cell factor (SCF) has been previously shown to protect immature erythroid and megakaryocytic cells in vitro from drug-induced apoptosis. However, the effect of SCF in vivo as a single myeloprotective agent has never been elucidated.
Experimental Design: The ability of SCF to prevent the occurrence of chemotherapy-induced anemia and thrombocytopenia was tested in a mouse model of cisplatin-induced myelosuppression. To highlight the importance of maintaining a continuous antiapoptotic signal in immature hematopoietic cells, we compared two treatment schedules: in the first schedule, SCF administration was interrupted during chemotherapy treatment and resumed thereafter, whereas in the second schedule, SCF was administered without interruption for 7 days, including the day of chemotherapy treatment.
Results: The administration of SCF to cisplatin-treated mice could preserve bone marrow integrity, inhibit apoptosis of erythroid and megakaryocytic precursors, prevent chemotherapy-induced anemia, and rapidly restore normal platelet production. Treatment with SCF increased the frequency of Bcl-2/Bcl-XL\u2013 positive bone marrow erythroid cells and sustained Akt activation in megakaryocytes. Myeloprotection was observed only when SCF was administered concomitantly with cisplatin and kept constantly present during the days following chemotherapy treatment.
Conclusions: SCF treatment can prevent the occurrence of chemotherapy-induced anemia and thrombocytopenia in mice, indicating a potential use of this cytokine in the supportive therapy of cancer patients
Calibrating Water Depths of Ordovician Communities: Lithological and Ecological Controls on Depositional Gradients in Upper Ordovician Strata of Southern Ohio and North-Central Kentucky, USA
Limestone and shale facies of the Upper Ordovician Grant Lake Formation (Katian: Cincinnatian, Maysvillian) are well
exposed in the Cincinnati Arch region of southern Ohio and north-central Kentucky, USA. These rocks record a gradual change in lithofacies and biofacies along a gently northward-sloping ramp. This gradient spans very shallow, olive-gray, platy, laminated dolostones with sparse ostracodes in the south to offshore, nodular, phosphatic, brachiopod-rich limestones and marls in the north. This study uses facies analysis in outcrop to determine paleoenvironmental parameters, particularly those related to water depth (e.g., position of the photic zone and shoreline, relative degree of environmental energy). Within a tightly correlated stratigraphic interval (the Mount Auburn and Straight Creek members of the Grant Lake Formation and the Terrill Member of the Ashlock
Formation), we document the occurrence of paleoenvironmental indicators, including desiccation cracks and light-depth indicators, such as red and green algal fossils and oncolites. This permitted recognition of a ramp with an average gradient of 10.20 cm water depth per horizontal kilometer. Thus, shallow subtidal (.lagoonal.) deposits in the upramp portion fall within the 1.5.6 m depth range, cross-bedded grainstones representing shoal-type environments fall within the 6.18 m depth range and subtidal, shell-rich deposits in the downramp portion fall within the 20.30 m depth range. These estimates match interpretations of depth independently derived from faunal and sedimentologic evidence that previously suggested a gentle ramp gradient and contribute to ongoing and future high-resolution paleontologic and stratigraphic studies of the Cincinnati Arch region
A novel ABCC6 variant causative of pseudoxanthoma elasticum
Pseudoxanthoma elasticum is an autosomal recessive heritable disorder caused by mutations in ABCC6. We describetwo siblings showing typical skin lesions and a clinical diagnosis of pseudoxanthoma elasticum. Genetic analysis ofABCC6 revealed a novel homozygous c.4041G > A variant located in the last position of exon 28 that compromises thesplicing donor site, resulting in a shorter messenger RNA. The deletion impairs the nucleotide-binding fold region,which is crucial for ABCC6 function
Inertial control of the mirror suspensions of the VIRGO interferometer for gravitational wave detection
In order to achieve full detection sensitivity at low frequencies, the
mirrors of interferometric gravitational wave detectors must be isolated from
seismic noise. The VIRGO vibration isolator, called 'superattenuator', is fully
effective at frequencies above 4 Hz. Nevertheless, the residual motion of the
mirror at the mechanical resonant frequencies of the system are too large for
the interferometer locking system and must be damped. A multidimensional
feedback system, using inertial sensors and digital processing, has been
designed for this purpose. An experimental procedure for determining the
feedback control of the system has been defined. In this paper a full
description of the system is given and experimental results are presented.Comment: 17 pages, 11 figures, accepted for publication on Review of
Scientific Instrument
A novel splicing variant of col2a1 in a fetus with achondrogenesis type ii: Interpretation of pathogenicity of in-frame deletions
Achondrogenesis type II (ACG2) is a lethal skeletal dysplasia caused by dominant pathogenic variants in COL2A1. Most of the variants found in patients with ACG2 affect the glycine residue included in the Gly-X-Y tripeptide repeat that characterizes the type II collagen helix. In this study, we reported a case of a novel splicing variant of COL2A1 in a fetus with ACG2. An NGS analysis of fetal DNA revealed a heterozygous variant c.1267-2_1269del located in intron 20/exon 21. The variant occurred de novo since it was not detected in DNA from the blood samples of parents. We generated an appropriate minigene construct to study the effect of the variant detected. The minigene expression resulted in the synthesis of a COL2A1 messenger RNA lacking exon 21, which generated a predicted in-frame deleted protein. Usually, in-frame deletion variants of COL2A1 cause a phenotype such as Kniest dysplasia, which is milder than ACG2. Therefore, we propose that the size and position of an in-frame deletion in COL2A1 may be relevant in determining the phenotype of skeletal dysplasia
Displacement power spectrum measurement of a macroscopic optomechanical system at thermal equilibrium
The mirror relative motion of a suspended Fabry-Perot cavity is studied in
the frequency range 3-10 Hz. The experimental measurements presented in this
paper, have been performed at the Low Frequency Facility, a high finesse
optical cavity 1 cm long suspended to a mechanical seismic isolation system
identical to that one used in the VIRGO experiment. The measured relative
displacement power spectrum is compatible with a system at thermal equilibrium
within its environmental. In the frequency region above 3 Hz, where seismic
noise contamination is negligible, the measurement distribution is stationary
and Gaussian, as expected for a system at thermal equilibrium. Through a simple
mechanical model it is shown that: applying the fluctuation dissipation theorem
the measured power spectrum is reproduced below 90 Hz and noise induced by
external sources are below the measurement.Comment: 11 pages, 9 figures, 2 tables, to be submitte
DINOSAUR FOOTPRINTS FROM THE GLEN ROSE FORMATION (PALUXY RIVER, DINOSAUR VALLEY STATE PARK, SOMERVELL COUNTY, TEXAS)
Dinosaur footprints are found in the Glen Rose Formation and other Lower Cretaceous stratigraphic units over much of central Texas (Pittman, 1989; Rogers, 2002; Farlow et al., 2006). Dinosaur tracks
were discovered in the rocky bed of the Paluxy River, near the town of Glen Rose, Texas, early in the 20th Century (Jasinski, 2008; Farlow et al., 2012b). Ellis W. Shuler of Southern Methodist University did pioneering studies on the dinosaur tracks (Shuler 1917, 1935, 1937), and Langston (1974) summarized much of the early literature.
What really put the dinosaur footprints of the Paluxy River on the map, though, were the herculean efforts that Roland T. Bird of the American Museum of Natural History made to secure trackway slabs for display at that institution and at the Texas Memorial Museum in Austin (Bird, 1985; Jasinski, 2008). In 1970 Dinosaur Valley State Park was created to protect the dinosaur footprints.
This guidebook briefly summarizes earlier work, and also serves as an interim report of research of our group still in progress, concerned with identifying the makers of the Paluxy River footprints, and determining what those animals were up to as they made their tracks. We will offer some comparisons of the dinosaur tracks of the Glen Rose Formation with those from other ichnofaunas around the world. The last quarter-century has seen an explosive increase in the technical literature dealing with dinosaur footprints, and we cannot possibly cite all of the relevant studies. For the sake of brevity we will emphasize publications from the present century, and summary papers and books, as much as possible. Even with this restriction, however, the literature is so vast that the literature-cited “tail” of this report starts to wag the “dog” of the text
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