The Trentonian (Late Ordovician) brachiopod fauna of Ontario: Evolution through a global warming event

This thesis, which examines the evolution of the Late Ordovician (early Katian) brachiopod fauna of Ontario, consists of two main parts: 1) a case study of the Late Ordovician Rhynchotrema–Hiscobeccus lineage of North America to investigate the morphological variations and evolutionary trends of brachiopod fauna in time and space, 2) the paleobiogeography of early Katian brachiopod fauna to explore their distribution patterns at a global scale and controlling factors. During the Katian, the North American craton experienced a first-order marine transgression. The early stage of this event in the early Katian (Trentonian, Chatfieldian) was marked by the development of extensive new habitats for the origin and radiation of brachiopods and other shelly benthos in epicontinental seas. Multivariate analysis, based on nine biometric characters of 171 Late Ordovician rhynchonellide specimens from nine localities in North America, demonstrated quantitatively that Hiscobeccus mackenziensis, as the earliest form of Hiscobeccus, evolved transitional characteristics between Rhynchotrema and the typical Hiscobeccus. During the late Katian (Maysvillian and Richmondian), Hiscobeccus diversified into larger, more globular, and more strongly lamellose shells, especially in the paleoequatorially located inland marine basins. The diversification and morphological trends in the Hiscobeccus lineage are interpreted as the result of adaptation to an environment with relatively shallow, muddy substrates, and low oxygen with unsteady nutrient supply in generally overheated epicontinental seas. Cluster and principal component analyses based on 33 brachiopod faunas of early Katian age, including 252 rhynchonelliform genera, revealed four global distinct faunal provinces, including Kazakhstan, Avalonia, epicontinental Laurentia, and Scoto-Appalachia. The late Darriwilian–early Katian brachiopod faunas of Laurentia show close similarities to those faunas of Siberia, Baltica, and other adjacent tectonic plates and terranes which indicate their semi-cosmopolitan distribution. During the early Katian, the Scoto-Appalachian brachiopod fauna, had a closer affinity to the brachiopod faunas along the western margins of Laurentia, whereas the early Katian brachiopod fauna of the intracratonic region in Laurentia had a closer affinity to the brachiopod fauna from the platform facies of Baltica than to those in pericratonic Laurentia. The brachiopod faunas exhibit strong provincialism during the late Katian, as the brachiopod fauna of Laurentia differentiated from those of Siberia, Kazakhstan, and South China. The faunal endemism within Laurentia was controlled by paleoecological factors related to tectonic events such as the Taconic Orogeny, as well as other factors such as paleolatitudinal faunal gradient, and varying substrate types

Assessing the Effect of Opium Dependence on Visual Evoked Potential (VEP) in Men

Abstract Background: Opium-dependence having different effects on the nervous system is a common problem, especially in the Middle East and Iran. The aim of this study is evaluating the effects of opium-dependence on visual evoked potential (VEP) in men. Methods: Thirty subjects with both chronic cigarette smoking and opium-dependence (group 1) and 30 subjects with only chronic cigarette smoking (group 2) were included in this cross-sectional case-control study and after urinary tests of opium, the pattern reversal visual evoked potentials (PRVEP) were recorded in the standard condition and variables such as N75, P100, N135 and amplitude were obtained and then analyzed with SPSS16. P value < 0.05 was assumed significant statistically. Findings: The mean of N75 (70.426 ± 22.028), P100 (115.457 ± 29.176) and N135 (165.402 ± 66.712) was not significantly different between the two groups. The mean of the amplitude of VEP in group 1 (6.856 ± 3.248) was significantly higher than group 2 (4.933 ± 2.50) (p < 0.05). Conclusion: Our study showed that chronic cigarette smoking and opium dependence have no significant effect on the late components of the VEP (N75, P100 and N135), but chronic cigarette smoking and opium-dependence together significantly increase the amplitude of VEP compared with chronic cigarette smoking alone, probably due to the chronic stimulatory effects of concomitant use of these two substances on the eyes and the visual nervous system. Keyword: Opium, Cigarette, Visual evoked potentia

Use of nanomaterials in the pretreatment of water samples for environmental analysis

The challenge of providing clean drinking water is of enormous relevance in today’s human civilization, being essential for human consumption, but also for agriculture, livestock and several industrial applications. In addition to remediation strategies, the accurate monitoring of pollutants in water sup-plies, which most of the times are present at low concentrations, is a critical challenge. The usual low concentration of target analytes, the presence of in-terferents and the incompatibility of the sample matrix with instrumental techniques and detectors are the main reasons that renders sample preparation a relevant part of environmental monitoring strategies. The discovery and ap-plication of new nanomaterials allowed improvements on the pretreatment of water samples, with benefits in terms of speed, reliability and sensitivity in analysis. In this chapter, the use of nanomaterials in solid-phase extraction (SPE) protocols for water samples pretreatment for environmental monitoring is addressed. The most used nanomaterials, including metallic nanoparticles, metal organic frameworks, molecularly imprinted polymers, carbon-based nanomaterials, silica-based nanoparticles and nanocomposites are described, and their applications and advantages overviewed. Main gaps are identified and new directions on the field are suggested.publishe

Online) An Open Access

ABSTRACT Soil moisture constitutes an important contribution to the knowledge of a part of the water balance at the global, regional, and local scales. Hence, this information is widely used in hydrological applications helping to quantify the diverse components of the water balance -infiltration, surface runoff, evaporation, deep percolation, and changes in water content. Remote sensing provides researchers and the community with the possibility to monitor changes in land and ocean around the globe, especially where in-situ observations are limited or non-existent. Microwave remote sensing enables satellite to get observations day and night regardless of the lighting conditions, and at selected frequencies, microwave emissions have a good cloud penetration which proves to be an immensely advantage over the oceans, which are on average 70% covered by clouds. We can mention the recent succes

Effects of Preparation Parameters on Characteristics of Cu-ZnO-Al 2 O 3 Catalysts for Low Pressure Methanol Synthesis

Abstract Catalysts containing copper, zinc and aluminum are widely used in hydrogenation and some other petrochemical processes. Among the latter are low temperature water -gas shift conversion and methanol synthesis at low pressure. In this paper, by using a special three-level experimental design, the effects of certain preparation parameters on crystalline phase of the catalysts for calcined and uncalcined precursors are discussed. The influence of such parameters on total surface area, copper metal surface area and also on reactor activity of the catalysts are also investigated

Removal of total petroleum hydrocarbons from oil refinery waste using granulated NaA zeolite nanoparticles modified with hexadecyltrimethylammonium bromide

Petroleum pollution is a common problem in industrial areas to such an extent that it poses a global threat. The wastes of oil refineries contain a wide variety of hydrocarbons. The aim of this study was to investigate the possibility to removal of total petroleum hydrocarbons (TPH) from Behregan oil refinery, Bushehr, Iran, by granulated nanozeolite NaA particles (NaA-ZNPs) modified with cationic surfactants. Synthesized NaA-ZNPs with a silica source extracted from Hordeum vulgare were granulated by an alginate granulation method and were modified by the cationic surfactant hexadecyltrimethylammonium bromide (CTAB). The CTAB-modified granulated NaA-ZNPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and the Brunauer-Emmett-Teller (BET) theory. Adsorption of TPH was studied using both a batch process and a continuous-flow process in a fixed-bed column. The effect of various parameters, including time, pH, adsorbent dosage, flow rate, and column height investigated, and the results were analyzed by GC-MS. The efficiency of the CTAB-modified granulated NaA-ZNPs was evaluated with one-way analysis of variance (ANOVA) software SPSS 21. The highest TPH removal efficiency for batch processing (92.3%) was achieved at adsorbent dosage 0.5 mg, pH 7, and 20 min contact time; the highest TPH removal efficiency for continuous processing (87.4%) was achieved at 15 cm column height and 17.26 mL min–1 flow rate. The results indicated the potential of CTAB-modified granulated NaA-ZNPs for absorbing TPH in treating oil-refinery waste.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

The Study of Figures of Speech (Simile, Metaphor, Trope, and Metonymy) in Bundahishn

This research aims at the study of figures of speech in Bundahishn. The research paradigm is of the qualitative type, and it is conducted using the content analysis method. The first hand source on which the research has been done is that of translated by Mehrdad Bahar to Contemporary Persian. The results of this research indicate that among the aforementioned figures of speech, simile has the highest frequency. And among different kinds of simile, sensuous simile has the highest frequency. After that comes sensuous-reasonable similes as more frequent which is used for making concepts more abstract. It seems that simile is one of the most efficient and expressive devices which is used mostly for making educational, philosophical, and abstract concepts pertinent to Creation and other subjects more receivable and concrete. In between, there are some issues which are sensuous, but normally, they are too hard to be understood; however, simile has made them more illuminated. In this work, only one metaphor was found while there is no figures of speech such as metonymy and trope. Maybe, because metaphor, metonymy, and trope make an educational work more difficult and complicated rather than being effective and illuminating. It seems that in this work, the most useful and deliberate style for teaching educational concepts has been used