159 research outputs found
Rare Earth Elements of modern shelf and deep-water articulated brachiopods: evaluation of seawater masses
Modern Rhynchonellids and Tcrcbratulids, obtained from water depths below the neritic zone (>500m) at 23 stations in the Caribbean Sea, North Atlantic, South Pacific and Southern Oceans, were investigated for their rare earth clement (REE) contents (Fig. I, Table I). The ÎŁREE of shelf (500-I 000 m) or deep-water (> I 000 m) brachiopod populations do not vary significantly between oceans/seas irrespective of water mass origins or influences by major currents
Efficacy of Hyaluronic Acid Injections versus Steroid Injections on Painful Tendinopathies
Background: Tendinopathies are manifested by pain, swelling, and limited mobility functions. Corticosteroid injections have been a mainstay in the treatment of tendinopathy, and are widely used despite the controversy regarding their usefulness and safety. The peri-tendinous administration of hyaluronic acid (HA) has shown promising results in the management of tendinopathy.
Objectives: The aim of the current study was to evaluate the efficacy of peri-tendinous injections of hyaluronic acid versus steroid injections on pain reduction in patients with painful tendinopathies.
Patients and methods: A prospective study, including a total of 90 patients with tendinopathy who were recruited from the Rheumatology and Rehabilitation Outpatient Clinic at Sohag University Hospital. Demographic data including age, disease duration, and tendon affected were evaluated. Patients were divided into three groups, each group contained 30 patients. First group received peritendinous steroid injection, second group received peritendinous hyaluronic acid injection, and the third group received both peritendinous hyaluronic acid and steroid injections. Groups were compared using in visual analogue scale, tenderness and range of motion after one week, one month and after 3 months from injection.
Results: Best improvement was seen in the group of combined hyaluronic acid and steroid; followed by the group of steroid injection alone, which showed early response better than hyaluronic acid alone.
Conclusion: Local injection for tendinopathies by combined hyaluronic acid and steroid gives significantly better and more long standing effect compared to either hyaluronic acid or steroid alone. On the other hand, monotherapy showed non-significant difference between steroid and hyaluronic acid
Brachiopod-based oxygen-isotope thermometer: Update and review
In the early 1950\u2019s, McCrea and Epstein and co-workers laid the foundation for the oxygen isotope-based thermometers. Many variations of the thermometer have been since formulated based on synthetic and biogenic carbonates. Overall, the use and application of oxygen isotope thermometers must consider and be specific as to the mineralogy, and whether it is synthetic, abiogenic or biogenic carbonate. Here, we propose an updated and refined oxygen-isotope thermometer based on a large database of articulated brachiopods from high to low latitudes, cold to warm and shallow to deep-water regimes. In general, brachiopod-based oxygen isotopes are offset from abiogenic calcite precipitated in thermodynamic equilibrium by about -1 . They maintain this offset and that allows for the determination of robust ambient water temperatures over the full marine spectrum. Thus, the specific brachiopod-based oxygen-isotope thermometer applies, with few exceptions, to most modern articulated brachiopods, and potentially their ancient counterparts, and it is as follows: T\ub0C =17.3750 \u2013 4.2535 (\u3b4c-\u3b4w) + 0.1473 (\u3b4c-\u3b4w)2 (N=578, r2 = 0.980) Furthermore, it is imperative that mineralogy and taxa be considered for their appropriateness in the application of oxygen isotope thermometers on synthetic, abiogenic and biogenic marine carbonates. Articulated brachiopods are ideal recorders of oceanographic parameters due to their sessile nature, widespread distribution, high abundance in the Paleozoic and Mesozoic, high resilience to most environmental stresses (e.g., climate change - global warming, ocean acidification), and the resistance of the calcite shell \u2013 the archive \u2013 to post-depositional diagenetic alteration
STUDY THE EFFECT OF SALINITY AND NUTRIENTS FOR THE GROWTH OF Najas marina AND ITS IMPACT TO AQUATIC BIODIVERSITY IN MADU GANGA RAMSAR WETLAND IN SRI LANKA
Madu Ganga is the latest addition to the Ramsar International Convention of Wetlands. Najas marinais an alien aquatic plant and 0.5 m long that are often branched toward the upward portion of the plant. The objective of the study was to study the impact of salinity and nutrients for the growth of Najas marina. Samples were collected for analysed water quality parameters from March, 2006 to January 2007 in the lagoon. Mapping was done using Garmin GPS map 76CS and Arc GIS used to developed maps.Mean nutrient such as, nitrate nitrogen, ammonia nitrogen and orthophosphate concentrations were observed 0.26 ± 0.3 mg/l, 0.057 ± 0.04 mg/l, and 0.354 ± 0.77 mg/l subsequently. Mean salinity variation in bottom and surface are 6.38 ± 6.65 ppt and 4.31 ±  4.68 ppt. Higher bottom salinity was observed in location number 02 (near to sea mouth) and  Najas marinawas not present in the area. Najas marina was also not recorded in upper part of the lagoon and fresh water streams studied. High density of Najas marina plants were observed in sampling location 07, 08 and 09, because of the high nutrient concentration flowing through feeding tributaries. More than 25 % of lagoon area was covered by Najas marina.
Origin of the Breno and Esino dolomites in the western Southern Alps (Italy): Implications for a volcanic influence
The Esino Limestone of the western Southern Alps represents a differentiated Ladinian-Lower Carnian (?)
carbonate platform comprised of margin, slope and peritidal inner platform facies up to 1000 m thick. A
major regional subaerial exposure event lead to coverage by another peritidal Lower Carnian carbonate
platform (Breno Formation). Multiphase dolomitization affected the carbonate sediments. Petrographic
examinations identified at least three main generations of dolomites (D1, D2, and D3) that occur as both
replacement and fracture-filling cements. These phases have crystal-size ranges of 3e35 mm (dolomicrite
D1), 40e600 mm (eu-to subhedral crystals D2), and 200 mm to 5 mm (cavity- and fracture-filling anhedral
to subhedral saddle dolomite D3), respectively.
The fabric retentive near-micritic grain size coupled with low mean Sr concentration (76 \ub1 37 ppm)
and estimated d18O of the parent dolomitizing fluids of D1 suggest formation in shallow burial setting at
temperature ~ 45e50 C with possible contributions from volcanic-related fluids (basinal fluids circulated
in volcaniclastics or related to volcanic activity), which is consistent with its abnormally high Fe
(4438 \ub1 4393 ppm) and Mn (1219 \ub1 1418 ppm) contents. The larger crystal sizes, homogenization
temperatures (D2, 108 \ub1 9 C; D3, 111 \ub1 14 C) of primary two-phase fluid inclusions, and calculated
salinity estimates (D2, 23 \ub1 2 eq wt% NaCl; D3, 20 \ub1 4 eq wt% NaCl) of D2 and D3 suggest that they
formed at later stages under mid-to deeper burial settings at higher temperatures from dolomitizing
fluids of higher salinity, which is supported by higher estimated d18O values of their parent dolomitizing
fluids. This is also consistent with their high Fe (4462 \ub1 4888 ppm; and 1091 \ub1 1183 ppm, respectively)
and Mn (556 \ub1 289 ppm and 1091 \ub1 1183 ppm) contents, and low Sr concentrations (53 \ub1 31 ppm and
57 \ub1 24 ppm, respectively).
The similarity in shale-normalized (SN) REE patterns and Ce (Ce/Ce*)SN and La (Pr/Pr*)SN anomalies of
the investigated carbonates support the genetic relationship between the dolomite generations and their
calcite precursor. Positive Eu anomalies, coupled with fluid-inclusion gas ratios (N2/Ar, CO2/CH4, Ar/He),
high F concentration, high F/Cl and high Cl/Br molar ratios suggest an origin from diagenetic fluids
circulated through volcanic rocks, which is consistent with the co-occurrence of volcaniclastic lenses in
the investigated sequence
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Oxygenation of the mid-Proterozoic atmosphere: clues from chromium isotopes in carbonates
Chromium (Cr) isotopes in marine sedimentary rocks can be used as a sensitive proxy for ancient atmospheric oxygen because Cr-isotope fractionation during terrestrial weathering only occurs when pO2 exceeds a threshold value. This is a useful system when applied to rocks of mid-Proterozoic age, where fundamental questions persist about atmospheric pO2 and its relationship to biological innovation. Whereas previous studies have focused on temporally limited iron-rich sedimentary rocks, we present new Cr-isotope data from a suite of mid-Proterozoic marine carbonate rocks. Application of the Cr-isotope proxy to carbonate rocks has the potential to greatly enhance the temporal resolution of Proterozoic palaeo-redox data. Here we report positive δ53Cr values in four carbonate successions, extending the mid-Proterozoic record of Cr-isotope fractionation – and thus pO2 above threshold values – back to ~1.1 Ga. These data suggest that pO2 sufficient for the origin of animals was transiently in place well before their Neoproterozoic appearance, although uncertainty in the pO2 threshold required for Cr-isotope fractionation precludes definitive biological interpretation. This study provides a proof of concept that the Cr-isotopic composition of carbonate rocks can provide important new constraints on the oxygen content of the ancient atmosphere.Organismic and Evolutionary Biolog
One-Year Water-Stable and Porous Bi(III) Halide Semiconductor with Broad-Spectrum Antibacterial Performance
Hybrid metal halide semiconductors are a unique family of materials with immense potential for numerous applications. For this to materialize, environmental stability and toxicity deficiencies must be simultaneously addressed. We report here a porous, visible light semiconductor, namely, (DHS)Bi2I8 (DHS = [2.2.2] cryptand), which consists of nontoxic, earth-abundant elements, and is water-stable for more than a year. Gas- and vapor-sorption studies revealed that it can selectively and reversibly adsorb H2O and D2O at room temperature (RT) while remaining impervious to N2 and CO2. Solid-state NMR measurements and density functional theory (DFT) calculations verified the incorporation of H2O and D2O in the molecular cages, validating the porous nature. In addition to porosity, the material exhibits broad band-edge light emission centered at 600 nm with a full width at half-maximum (fwhm) of 99 nm, which is maintained after 6 months of immersion in H2O. Moreover, (DHS)Bi2I8 exhibits bacteriocidal action against three Gram-positive and three Gram-negative bacteria, including antibiotic-resistant strains. This performance, coupled with the recorded water stability and porous nature, renders it suitable for a plethora of applications, from solid-state batteries to water purification and disinfection
Computational Modelling of Genome-Side Transcription Assembly Networks Using a Fluidics Analogy
Understanding how a myriad of transcription regulators work to modulate mRNA output at thousands of genes remains a fundamental challenge in molecular biology. Here we develop a computational tool to aid in assessing the plausibility of gene regulatory models derived from genome-wide expression profiling of cells mutant for transcription regulators. mRNA output is modelled as fluid flow in a pipe lattice, with assembly of the transcription machinery represented by the effect of valves. Transcriptional regulators are represented as external pressure heads that determine flow rate. Modelling mutations in regulatory proteins is achieved by adjusting valves' on/off settings. The topology of the lattice is designed by the experimentalist to resemble the expected interconnection between the modelled agents and their influence on mRNA expression. Users can compare multiple lattice configurations so as to find the one that minimizes the error with experimental data. This computational model provides a means to test the plausibility of transcription regulation models derived from large genomic data sets
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