The fossil bivalve Angulus benedeni benedeni: A potential seasonally resolved stable-isotope-based climate archive to investigate Pliocene temperatures in the southern North Sea basin

Bivalves record seasonal environmental changes in their shells, making them excellent climate archives. However, not every bivalve can be used for this end. The shells have to grow fast enough so that micrometre- to millimetre-sampling can resolve sub-annual changes. Here, we investigate whether the bivalve Angulus benedeni benedeni is suitable as a climate archive. For this, we use ca. 3-million-year-old specimens from the Piacenzian collected from a temporary outcrop in the Port of Antwerp area (Belgium). The subspecies is common in Pliocene North Sea basin deposits, but its lineage dates back to the late Oligocene and has therefore great potential as a high-resolution archive. A detailed assessment of the preservation of the shell material by micro-X-ray fluorescence, X-ray diffraction, and electron backscatter diffraction reveals that it is pristine and not affected by diagenetic processes. Oxygen isotope analysis and microscopy indicate that the species had a longevity of up to a decade or more and, importantly, that it grew fast and large enough so that seasonally resolved records across multiple years were obtainable from it. Clumped isotope analysis revealed a mean annual temperature of 13.5±3.8°C. The subspecies likely experienced slower growth during winter and thus may not have recorded temperatures year-round. This reconstructed mean annual temperature is 3.5°C warmer than the pre-industrial North Sea and in line with proxy and modelling data for this stratigraphic interval, further solidifying A. benedeni benedeni's use as a climate recorder. Our exploratory study thus reveals that Angulus benedeni benedeni fossils are indeed excellent climate archives, holding the potential to provide insight into the seasonality of several major climate events of the past ∼25 million years in northwestern Europe

Design of Experiments for Screening

The aim of this paper is to review methods of designing screening experiments, ranging from designs originally developed for physical experiments to those especially tailored to experiments on numerical models. The strengths and weaknesses of the various designs for screening variables in numerical models are discussed. First, classes of factorial designs for experiments to estimate main effects and interactions through a linear statistical model are described, specifically regular and nonregular fractional factorial designs, supersaturated designs and systematic fractional replicate designs. Generic issues of aliasing, bias and cancellation of factorial effects are discussed. Second, group screening experiments are considered including factorial group screening and sequential bifurcation. Third, random sampling plans are discussed including Latin hypercube sampling and sampling plans to estimate elementary effects. Fourth, a variety of modelling methods commonly employed with screening designs are briefly described. Finally, a novel study demonstrates six screening methods on two frequently-used exemplars, and their performances are compared

The Alvarez impact theory of mass extinction; limits to its applicability and the „great expectations syndrome”

For the past three decades, the Alvarez impact theory of mass extinction, causally related to catastrophic meteorite impacts, has been recurrently applied to multiple extinction boundaries. However, these multidisciplinary research efforts across the globe have been largely unsuccessful to date, with one outstanding exception: the Cretaceous-Paleogene boundary. The unicausal impact scenario as a leading explanation, when applied to the complex fossil record, has resulted in force-fitting of data and interpretations ("great expectations syndrome". The misunderstandings can be grouped at three successive levels of the testing process, and involve the unreflective application of the impact paradigm: (i) factual misidentification, i.e., an erroneous or indefinite recognition of the extraterrestrial record in sedimentological, physical and geochemical contexts, (ii) correlative misinterpretation of the adequately documented impact signals due to their incorrect dating, and (iii) causal overestimation when the proved impact characteristics are doubtful as a sufficient trigger of a contemporaneous global cosmic catastrophe. Examples of uncritical belief in the simple cause-effect scenario for the Frasnian-Famennian, Permian-Triassic, and Triassic-Jurassic (and the Eifelian-Givetian and Paleocene-Eocene as well) global events include mostly item-1 pitfalls (factual misidentification), with Ir enrichments and shocked minerals frequently misidentified. Therefore, these mass extinctions are still at the first test level, and only the F-F extinction is potentially seen in the context of item-2, the interpretative step, because of the possible causative link with the Siljan Ring crater (53 km in diameter). The erratically recognized cratering signature is often marked by large timing and size uncertainties, and item-3, the advanced causal inference, is in fact limited to clustered impacts that clearly predate major mass extinctions. The multi-impact lag-time pattern is particularly clear in the Late Triassic, when the largest (100 km diameter) Manicouagan crater was possibly concurrent with the end-Carnian extinction (or with the late Norian tetrapod turnover on an alternative time scale). The relatively small crater sizes and cratonic (crystalline rock basement) setting of these two craters further suggest the strongly insufficient extraterrestrial trigger of worldwide environmental traumas. However, to discuss the kill potential of impact events in a more robust fashion, their location and timing, vulnerability factors, especially target geology and palaeogeography in the context of associated climate-active volatile fluxes, should to be rigorously assessed. The current lack of conclusive impact evidence synchronous with most mass extinctions may still be somewhat misleading due to the predicted large set of undiscovered craters, particularly in light of the obscured record of oceanic impact events

Astronomical Distance Determination in the Space Age: Secondary Distance Indicators

The formal division of the distance indicators into primary and secondary leads to difficulties in description of methods which can actually be used in two ways: with, and without the support of the other methods for scaling. Thus instead of concentrating on the scaling requirement we concentrate on all methods of distance determination to extragalactic sources which are designated, at least formally, to use for individual sources. Among those, the Supernovae Ia is clearly the leader due to its enormous success in determination of the expansion rate of the Universe. However, new methods are rapidly developing, and there is also a progress in more traditional methods. We give a general overview of the methods but we mostly concentrate on the most recent developments in each field, and future expectations. © 2018, The Author(s)

Prophylactic diclofenac infusions in major orthopedic surgery: effects on analgesia and acute phase proteins

The influence of diclofenac, given by continuous i.v. infusion starting preoperatively, on postoperative pain and inflammation was assessed in a double‐blind, randomized, placebo‐controlled study in 40 patients scheduled for major orthopedic surgery. Starting 30 min before induction the patients received either diclofenac (0.35 mg.kg‐1 bolus followed by a constant‐rate infusion of 90 μ.min‐1) or placebo for 24 h. The pain intensity (VAS) and the amount of rescue narcotic (piritramide on demand) were significantly lower in the diclofenac group from 4 and 6 h postsurgery, respectively, till end of infusion. Acute phase proteins used as inflammation markers (C‐reactive protein, α1‐chymotrypsin, α1‐acid glycoprotein, haptoglobin and coeruloplasmin) showed similar variations in both groups for 24 h. The diclofenac treatment had no influence on hematological and coagulation profiles, nor on muscle and liver enzymes in comparison with placebo. Both patients and observer rated the diclofenac treatment as significantly superior to the placebo treatment. © 1992 Acta Anaesthesiologica Scandinavica FondenSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Thoracic epidural bupivacaine-fentanyl anesthesia for percutaneous cholecystolithotomy in high-risk patients

Background and Objectives. The efficacy of a thoracic epidural block was assessed in 12 high-risk patients scheduled for elective percutaneous cholecystolithotomy. Methods. A thoracic epidural catheter was inserted at level T8-9. The amount of 0.5% bupivacaine to block two thoracic epidural segments was calculated, adapted to age, height, and epidural level, and administered with 50 μg fentanyl. Hemodynamic and respiratory variables and patients' pain and movement were assessed throughout the procedure. Results. Anesthesia was obtained with a minimal dose of local anesthetic. All patients were satisfied with this method. Neither hemodynamic nor respiratory impairment were observed after epidural injection. However, vagal reactions reported in other studies occurred in two patients upon puncture of the gallbladder. Conclusions. This minimally invasive anesthetic technique seems to be a good alternative for high-risk patients. However, careful monitoring of heart rate and blood pressure remains mandatory throughout the procedure.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Haemodynamic changes during anaesthesia induced and maintained with propofol

Summary: The haemodynamic effects of propofol, given as a single dose of 2 mg kg-1 immediately followed by a continuous infusion of 6 mg kg-1 h-1, were studied in 10 elderly patients premedicated with lorazepam 1 mg i.v. All patients breathed room air spontaneously. Unconsciousness was successfully induced in all patients and persisted during the 60 min of the infusion. Statistically significant decreases in systolic and diastolic arterial pressures were observed 2 min after induction (28% and 19% respectively) and during infusion (30% and 25% respectively) and were related to decreases in systemic vascular resistance (21% following induction and 30% during infusion). Cardiac output was not affected at any time nor were stroke volume and heart rate. We conclude that the arterial hypotension associated with the induction and infusion of propofol is mainly a result of a decrease in afterload without compensatory increases in heart rate or cardiac output. © 1988 British Journal of Anaesthesia.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Haemodynamic effects and oxygen transport during intentional haemodilution with Elohes 6% in elderly patients

SCOPUS: cp.jinfo:eu-repo/semantics/publishe

Reversal of flunitrazepam with flumazenil: Duration of antagonist activity

The duration of action, dose requirements and efficacy of flumazenil, a specific benzodiazepine antagonist, were evaluated in 50 patients scheduled for orthopaedic surgery under local anaesthesia and flunitrazepam sedation. Fifteen minutes after injection of flunitrazepam 0.03 mg kg-1 the patients received placebo or flumazenil i.v. in a randomized, double-blind and titrated fashion. At selected time intervals, sedation, anterograde amnesia, muscular hypotonia, orientation in time and space, comprehension and collaboration were evaluated. Compared with placebo, flumazenil promptly reversed sedation for 30 min, hypotonia for 45 min and anterograde amnesia for 60 min, and improved orientation and collaboration for 60 min. However, after 90 min significant recurrent sedation was observed, while anterograde amnesia reappeared after 60 and up to 120 min. No side-effects were noted at any time. The dose of flumazenil required for reversal of flunitrazepam sedation was 0.35 ± 0.15 mg (mean ± SD).SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe