1,371 research outputs found
Characterizing the Oldenburg âButter Shaleâ from the Upper Ordovician (Katian) Waynesville Formation along the Cincinnati Arch, USA
The Upper Ordovician (Katian) strata of the Cincinnati Arch contain numerous mudstone units known locally as âbutter shalesâ or âtrilobite shalesâ. Most of these deposits are heavily collected for their excellently-preserved trilobites. The Oldenburg Butter Shale, however, is a previously-undescribed mudstone package from the Waynesville Formation, known only from limited exposure near Oldenburg, Indiana. The Oldenburg Shale is a 2 m-thick mudstone package with minor beds of shelly packstones, and calcisiltite-filled gutter casts. It contains abundant articulated trilobites. The mudstone portion contains illite, chlorite, quartz, calcite and traces of dolomite and pyrite. In outcrop, the shale exhibits no obvious bedding and breaks conchoidally. When cut and polished, the mudstone shows a mottled fabric, containing Lingulichnus and Chondrites trace fossils. The shelly units contain brachiopods, gastropods, and bryozoans. The gutter casts are 20 â 30 cm wide, display hummocky stratification, and contain Lingulichnus. Faunally, the Oldenburg is very unlike surrounding Waynesville strata. Instead of being dominated by brachiopods as is typical, the Oldenburg fauna consists of abundant bivalves (Modiolopsis, Ambonychia, and Caritodens), lingulid brachiopods, and the trilobites (Isotelus, and Flexicalymene, and rare Amphilichas in the upper 30 cm). Articulate brachiopods are represented in the shale to a limited extent by the genera Zygospira and Platystrophia. The shale also contains bryozoans, orthoconic cephalopods, rare crinoids and conulariids. Conodonts and scolecodonts are a major component of the microfauna. Taphonomy of the fossils, together with sedimentological features, indicates that this butter shale accumulated rapidly as a series of episodes of distal storm-generated mud and silt flows. Towards the top of the mudstone is a horizon of small concretions, about 7 cm wide. Overlying the butter shale is the pyrite crusted surface of the Mid-Richmondian Unconformity which removes the Oldenburg shale in most other locations. The concretions present at the top of the shale are the likely product of the prolonged sediment starvation accompanying this unconformity
The StO2 non-invasive tissue hypoperfusion monitor as a screening tool for early sepsis detection in the emergency department
Background: Early Recognition of patients with sepsis induced tissue hypoperfusion (SITH) Remains a significant clinical challenge. Non--âinvasive Tissue oxygenation saturation (StO2) Monitors have been developed to provide rapid, low--âcost, and non--âinvasive bedside assessments of tissue oxygen extraction; they have not been well validated as an initial screening tool for sepsis in the ED. Objectives: To Assess the efficacy of initial bedside StO2 Readings in the early identification of patients with SITH And to compare StO2 Readings with lactate levels. Methods: IRB approved, prospective, observational pilot study of a convenience sample of ED Patients presenting with a sepsis continuum diagnosis. Setting: Urban Tertiary care center with 90k visits/yr. Inclusion criteria: Suspicion Of new infection plus 2 SIRS criteria. Exclusion criteria: \u3c18 Or no suspicion of infection. Study procedures: Demographics, co--âmorbidities, clinical data, treatment, disposition, and mortality were collected. A Portable In--âSpectra âSpot Checkâ StO2 Monitor was used totake a StO2 Reading at the thenar eminence; a second reading was taken three hours later. All Investigators were trained with the device to record data with a high degree of accuracy and reliability. Abnormal StO2 Was defined as \u3c80% or\u3e91%. The Study was observational and there were no clinical interventions. Descriptive Statistics were employed and Sensitivity/Specificity, Likelihood ratios, andNPV/PPV Were calculated with 95% Confidence intervals (in parenthesis) where appropriate. Results: 79 Patients were enrolled into the study. Mean Age 63 (range 21--â96). 61 Were admitted to the hospital, 5 To ICU (100% With St02\u3c74%). 3 Mortalities (100% With St02\u3c72%). 75% (9/12) Of patients with an ED Lactate \u3e2.3 Had an abnormal St02. 80% (4/5) For lactate \u3e3, And 100%(3/3) For Lactate \u3e4. For Any initial SITH (MAP\u3c65 Or Lactate \u3e2.3): Sensitivity: 92% (77.5--â98.2), Specificity: 82.2% (67.9--â92), +LR: 5.2 (2.7--â9.7), --âLR: 0.1 (0.03--â0.3), PPV: 80.5% (65.1--â91.2), NPV: 92.5% (80--â98.3). Conclusions: StO2 May be a useful, rapid, low--âcost, and non--âinvasive bedside screening tool for SITH In the ED, Particularly for severely ill patients. Further Studies are needed to determine StO2âs Ability to predict mortality and assess response to therapy
Taphonomic Comparisons of Two Laurentian Upper Ordovician Epeiric Sea âSmall Shelly Faunasâ
The Elgin Member of the Upper Ordovician (Katian) Maquoketa Formation of Iowa contains phosphorite beds consisting of millimeter-scale phosphatic fossils, primarily steinkerns. Similar beds occur in the coeval strata of the classic Cincinnatian Series around the Cincinnati, Ohio area. Initial sampling of the phosphate-rich beds of the Maquoketa allows comparison between the faunal composition and taphonomy of these beds and collections from the more extensively sampled Cincinnatian strata. We isolated these fossils by dissolution of bulk samples in acetic acid and examined the same strata in thin section to study the fossils in context. The Maquoketa diminutive phosphatized fossils have been interpreted as evidence of dwarfed faunas indicative of environmental stress, such as anoxia, which may have also contributed to phosphogenesis. An alternative explanation for the small size is that phosphogenesis was size-selective and that phosphatic particles were concentrated by reworking as less-durable shell material was destroyed. These hypotheses can be tested by examining the fauna for ânormalâ sized elements. Insoluble residue from sampled phosphate-rich strata in both field areas yields abundant molluscan steinkerns, as well as crinoid columnals, conodonts, scolecodonts, bryozoan zooecia steinkerns and other fossils associated with a normal marine fauna. In Cincinnatian occurrences, the composition of the phosphatic assemblages is variable but is a reflection of the variability of faunal composition seen in these strata rather than an indication of an unusual fauna associated with extreme conditions; most are associated with diverse marine assemblages. Insoluble residues from both areas yield steinkerns that precipitated in small pores within larger skeletons. This phenomenon can be seen in thin section, where phosphate is present within certain parts of the larger preserved skeletons. The maximum size of the steinkerns of the Maquoketa is larger than those of most Cincinnatian occurrences, although size is variable in Cincinnatian occurrences. In Cincinnatian strata the abundance of small phosphatic fossils correlates with evidence for reworking; heavily reworked beds yield the most residue. Examined in thin section, the sampled strata of the Maquoketa appear to be heavily reworked and represent an extreme endmember of this concentration of durable phosphatic material. Detailed examination using an SEM and associated XRF elemental mapping reveals that the phosphatic steinkerns of both localities are very similar in their taphonomy. Both consist of botryoidal growths of carbonate fluorapatite (CFA). The botryoidal growth appears to have nucleated on the walls of the original shell, first forming a lining of variable thickness. Some steinkerns have secondary botryoidal growths on the outside of the steinkern indicating continued precipitation of CFA after destruction of the original shell. This secondary precipitation suggests that reworking played a role not only in concentrating the phosphatic material but also in encouraging continued precipitation of CFA. The size of the available pore space appears to have played a role in encouraging the precipitation of CFA. In thin section the CFA is limited to smaller parts of larger shells, such as the apices of gastropods and did not precipitate on the inside of the larger, more open spaces within the shell. Many of the phosphate-filled spaces are also sediment-filled, suggesting that subdivision of the larger space into smaller pores enhanced the precipitation of CFA. The difference in the maximum size of the steinkern achieved in the different assemblages suggests that geochemical factors affected size limits. The most distinctive aspect of phosphate-rich Ordovician strata of mid-Laurentia is the degree of reworking that concentrated the durable small fossils. Details of taphonomy also suggest that phosphate precipitation was an iterative process enhanced by reworking, and that small pore spaces enhanced this mineralization, thus selectively preserving certain sizes and parts of the larger fauna
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
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
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
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
Monitoring multiple myeloma by idiotype-specific peptide binders of tumor-derived exosomes.
Abstract Tumor-derived exosomes (TDEs) play a pivotal role in tumor establishment and progression, and are emerging biomarkers for tumor diagnosis in personalized medicine. To date, there is a lack of efficient technology platforms for exosome isolation and characterization. Multiple myeloma (MM) is an incurable B-cell malignancy due to the rapid development of drug-resistance. MM-released exosomes express the immunoglobulin B-cell receptor (Ig-BCR) of the tumor B-cells, which can be targeted by Idiotype-binding peptides (Id-peptides). In this study, we analyzed the production of MM-released exosomes in the murine 5T33MM multiple myeloma model as biomarkers of tumor growth. To this end, we selected Id-peptides by screening a phage display library using as bait the Ig-BCR expressed by 5T33MM cells. By FACS, the FITC-conjugated Id-peptides detected the MM-released exosomes in the serum of 5T33MM-engrafted mice, levels of which are correlated with tumor progression at an earlier time point compared to serum paraprotein. These results indicate that Id-peptide-based recognition of MM-released exosomes may represent a very sensitive diagnostic approach for clinical evaluation of disease progression
SI113, a Specific Inhibitor of the Sgk1 Kinase Activity that Counteracts Cancer Cell Proliferation
Background/Aims: Published observations on serum and glucocorticoid regulated kinase 1 (Sgk1) knockout murine models and Sgk1-specific RNA silencing in the RKO human colon carcinoma cell line point to this kinase as a central player in colon carcinogenesis and in resistance to taxanes. Methods: By in vitro kinase activity inhibition assays, cell cycle and viability analysis in human cancer model systems, we describe the biologic effects of a recently identified kinase inhibitor, SI113, characterized by a substituted pyrazolo[3,4-d]pyrimidine scaffold, that shows specificity for Sgk1. Results: SI113 was able to inhibit in vitro cell growth in cancer cells derived from tumors with different origins. In RKO cells, this kinase inhibitor blocked insulin-dependent phosphorylation of the Sgk1 substrate Mdm2, the main regulator of p53 protein stability, and induced necrosis and apoptosis when used as a single agent. Finally, SI113 potentiated the effects of paclitaxel on cell viability. Conclusion: Since SI113 appears to be effective in inducing cell death in RKO cells, potentiating paclitaxel sensitivity, we believe that this new molecule could be efficiently employed, alone or in combination with paclitaxel, in colon cancer chemotherapy
The variable finesse locking technique
Virgo is a power recycled Michelson interferometer, with 3 km long Fabry-Perot cavities in the arms. The locking of the interferometer has been obtained with an original lock acquisition technique. The main idea is to lock the instrument away from its working point. Lock is obtained by misaligning the power recycling mirror and detuning the Michelson from the dark fringe. In this way, a good fraction of light escapes through the antisymmetric port and the power build-up inside the recycling cavity is extremely low. The benefit is that all the degrees of freedom are controlled when they are almost decoupled, and the linewidth of the recycling cavity is large. The interferometer is then adiabatically brought on to the dark fringe. This technique is referred to as variable finesse, since the recycling cavity is considered as a variable finesse Fabry-Perot. This technique has been widely tested and allows us to reach the dark fringe in few minutes, in an essentially deterministic way
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