Progressive environmental deterioration in northwestern Pangea leading to the latest Permian extinction

Stratigraphic records from northwestern Pangea provide unique insight into global processes that occurred during the latest Permian extinction (LPE). We examined a detailed geochemical record of the Festningen section, Spitsbergen. A stepwise extinction is noted as: starting with (1) loss of carbonate shelly macrofauna, followed by (2) loss of siliceous sponges in conjunction with an abrupt change in ichnofabrics as well as dramatic change in the terrestrial environment, and (3) final loss of all trace fossils. We interpret loss of carbonate producers as related to shoaling of the lysocline in higher latitudes, in relationship to building atmospheric CO2. The loss of siliceous sponges is coincident with the global LPE event and is related to onset of high loading rates of toxic metals (Hg, As, Co) that we suggest are derived from Siberian Trap eruptions. The final extinction stage is coincident with redox-sen- sitive trace metal and other proxy data that suggest onset of anoxia after the other extinction events. These results show a remarkable record of progressive environmental deterioration in northwestern Pangea during the extinction crises

Void morphology in polyethylene/carbon black composites

A combination of small angle neutron scattering (SANS) and contrast matching techniques is used to determine the size and quantity of voids incorporated during fabrication of polyethylene/carbon black composites. The analysis used to extract void morphology from SANS data is based on the three-phase model of microcrack determination via small angle x-rayscattering (SAXS) developed by W.Wu{sup 12} and applied to particulate reinforced composites

Role of dopant counter-anion functionality in polyaniline salts/blends and implications to morphology

In this paper, wide and small angle X-ray scattering techniques (i.e., WAXS and SAXS) and light microscopy are used to characterize the influence of the dopant`s structure on the morphology of both polyaniline salt and blend. In an attempt to modify the morphology of the PANI-ES, the authors have evaluated a number of doping acids (i.e., methane sulfonic acid (HMSA), butane sulfonic acid (HBSA), dodecyl benzene sulfonic acid (HDBSA) and camphor sulfonic acid (HCSA)) that vary in size and polarity to better understand the role of the acid in PANI-ES`s morphology and the resulting electrical conductivity. These salts were solution blended with polycaprolactam using hexafluoro-2-propanol (HFIP) as a solvent. The other goal was to investigate the effect of the counter-anion structure on the nature of the phase separated PANI-ES network. The shape of the PANI-ES network in the host polycaprolactam has important implications on the nature of conduction behavior and the final electrical conductivity of the blend

Earliest Triassic microbialites in the South China Block and other areas; controls on their growth and distribution

Earliest Triassic microbialites (ETMs) and inorganic carbonate crystal fans formed after the end-Permian mass extinction (ca. 251.4 Ma) within the basal Triassic Hindeodus parvus conodont zone. ETMs are distinguished from rarer, and more regional, subsequent Triassic microbialites. Large differences in ETMs between northern and southern areas of the South China block suggest geographic provinces, and ETMs are most abundant throughout the equatorial Tethys Ocean with further geographic variation. ETMs occur in shallow-marine shelves in a superanoxic stratified ocean and form the only widespread Phanerozoic microbialites with structures similar to those of the Cambro-Ordovician, and briefly after the latest Ordovician, Late Silurian and Late Devonian extinctions. ETMs disappeared long before the mid-Triassic biotic recovery, but it is not clear why, if they are interpreted as disaster taxa. In general, ETM occurrence suggests that microbially mediated calcification occurred where upwelled carbonate-rich anoxic waters mixed with warm aerated surface waters, forming regional dysoxia, so that extreme carbonate supersaturation and dysoxic conditions were both required for their growth. Long-term oceanic and atmospheric changes may have contributed to a trigger for ETM formation. In equatorial western Pangea, the earliest microbialites are late Early Triassic, but it is possible that ETMs could exist in western Pangea, if well-preserved earliest Triassic facies are discovered in future work

Enjoyment, Exploration and Education: Understanding the Consumption of Pornography among Young Men with Non-Exclusive Sexual Orientations

This qualitative research examines the influence of pornography consumption on young men with non-exclusive sexual orientations. Drawing on 35 in-depth interviews with young men from an elite university in the north-eastern United States, we examine how pornography was experienced as a leisure activity to be consumed in free time. Rather than focusing on the potential harms of pornography, we use an inductive analytic approach to explore the broader range of experiences that participants had, since the time they first consumed pornography. We demonstrate that pornography had educational benefits for these young men, related to their sexual desires, emerging sexual identities and for developing new sexual techniques. This study is part of a growing body of research that seeks to develop a holistic understanding of pornography in society, addressing the absence of the lived experience of the consumer in most pornography research

The Impact of Global Warming and Anoxia on Marine Benthic Community Dynamics: an Example from the Toarcian (Early Jurassic)

The Pliensbachian-Toarcian (Early Jurassic) fossil record is an archive of natural data of benthic community response to global warming and marine long-term hypoxia and anoxia. In the early Toarcian mean temperatures increased by the same order of magnitude as that predicted for the near future; laminated, organic-rich, black shales were deposited in many shallow water epicontinental basins; and a biotic crisis occurred in the marine realm, with the extinction of approximately 5% of families and 26% of genera. High-resolution quantitative abundance data of benthic invertebrates were collected from the Cleveland Basin (North Yorkshire, UK), and analysed with multivariate statistical methods to detect how the fauna responded to environmental changes during the early Toarcian. Twelve biofacies were identified. Their changes through time closely resemble the pattern of faunal degradation and recovery observed in modern habitats affected by anoxia. All four successional stages of community structure recorded in modern studies are recognised in the fossil data (i.e. Stage III: climax; II: transitional; I: pioneer; 0: highly disturbed). Two main faunal turnover events occurred: (i) at the onset of anoxia, with the extinction of most benthic species and the survival of a few adapted to thrive in low-oxygen conditions (Stages I to 0) and (ii) in the recovery, when newly evolved species colonized the re-oxygenated soft sediments and the path of recovery did not retrace of pattern of ecological degradation (Stages I to II). The ordination of samples coupled with sedimentological and palaeotemperature proxy data indicate that the onset of anoxia and the extinction horizon coincide with both a rise in temperature and sea level. Our study of how faunal associations co-vary with long and short term sea level and temperature changes has implications for predicting the long-term effects of “dead zones” in modern oceans

Clinical Laboratory Parameters Among Adult Males During a Primaquine Chemoprophylaxis Trial in Irian Jaya, Indonesia

Primakuin yang digunakan sebagai profilaksis malaria terbukti efektif dan diterima dengan baik oleh tubuh manusia yang normal terhadap aktivitas enzim 6 glukosa-6 fosfat dehidrogenase (G-6PD). Pemeriksaan laboratoris klinik adalah bagian dari uji coba secara acak dengan kontrol plasebo dalam rangka mengevaluasi penggunaan primakuin sebagai profilaksis pada penduduk transmigran yang tidak kebal di Irian Jaya. Penelitian ini dilakukan terhadap 129 pria Jawa dewasa yang normal G-6PDnya. Pemeriksaan hematologi, fungsi hati dan ginjal, dan pemeriksaan limfosit dilakukan berulang kali selama waktu penelitian profilaksis dilakukan untuk menjamin keamanan dari sukarelawan tersebut dan mengawasi Perubahan yang mungkin terjadi akibat obat profilaksis. Seperti yang diperkirakan, pengguna primakuin tidak menunjukkan gejala peningkatan methemoglobin yang kembali dalam batas normal setelah 7 hari pemberian dosis terakhir. Pada akhir penelitian (12 bulan profilaksis) nilai hematologi, fungsi hati dan ginjal, dan nilai limfosit dari kelompok primakuin sebanding dengan kelompok plasebo, dan berada dalam batas nilai normal untuk orang Indonesia.Hasil penelitian ini memberikan masukan adanya keluhan fisik yang sedikit dari sukarelawan pengguna profilaksis primakuin. Untuk membuktikan hasil penelitian ini dan mempersiapkan penggunaan secara umum primakuin untuk profilaksis malaria, perlu dilakukan uji coba lebih lanjut keamanan primakuin. Di Indonesia, primakuin tidak digunakan sebagai profilaksis dan laporan hasil penelitian ini hendaknya tidak ditafsirkan sebagai laporan keamanan dari primakuin