Dynamic Testing of Materials for Galvanising Pot Roll Bearings with Improved Performance.

Galvanising pot roll bearings are subjected to severe deterioration due to the corrosion of the bearing materials in liquid Zn, resulting in maintenance stops that can cost thousands of pounds per hour in downtime. Dynamic wear testing in molten Zn-Al and Zn-Al-Mg was conducted to assess the corrosion and wear resistance of three material pairs using a bespoke testing rig. The materials investigated in this study were Wallex6 coated with WC-Co, stainless steel 316L coated with AlO, and as-received Wallex6 and Wallex4 alloys.

The Effect of Sliding Speed on the Tribological Properties of Ceramic Materials.

Ceramics are considered to be candidate materials for galvanising pot bearing materials due to their excellent corrosion resistance in many molten metals. Galvanising pot roll bearings must have excellent wear resistance, and, therefore, it is important to understand the wear behaviour of prospective bearing materials. This study investigates the friction- and wear-resistant properties of select ceramics, namely, pure hBN, BN M26, AlN-BN, Macor, 3YSZ, AlO and SiN.

Absence of ancient DNA in sub-fossil insect inclusions preserved in 'Anthropocene' Colombian copal.

Insects preserved in copal, the sub-fossilized resin precursor of amber, have potential value in molecular ecological studies of recently-extinct species and of extant species that have never been collected as living specimens. The objective of the work reported in this paper was therefore to determine if ancient DNA is present in insects preserved in copal. We prepared DNA libraries from two stingless bees (Apidae: Meliponini: Trigonisca ameliae) preserved in 'Anthropocene' Colombian copal, dated to 'post-Bomb' and 10,612±62 cal yr BP, respectively, and obtained sequence reads using the GS Junior 454 System.

Can long-range PCR be used to amplify genetically divergent mitochondrial genomes for comparative phylogenetics? A case study within spiders (Arthropoda: Araneae).

The development of second generation sequencing technology has resulted in the rapid production of large volumes of sequence data for relatively little cost, thereby substantially increasing the quantity of data available for phylogenetic studies. Despite these technological advances, assembling longer sequences, such as that of entire mitochondrial genomes, has not been straightforward. Existing studies have been limited to using only incomplete or nominally intra-specific datasets resulting in a bottleneck between mitogenome amplification and downstream high-throughput sequencing.

A new species of Proceroplatus Edwards (Diptera: Keroplatidae) in Miocene amber from the Dominican Republic.

Keroplatid fungus gnats (Diptera: Keroplatidae) were hitherto known from the Caribbean island of Hispaniola from a single named species in Miocene amber from the Dominican Republic. Here we describe the new fossil species Proceroplatus preziosii Evenhuis & Penney based on a mature male specimen, which differs markedly from both fossil and extant taxa in the structure of its gonostyli and U-shaped wing pattern. We also document the first record of extant Keroplatidae, Proceroplatus pictipennis (Williston), from Hispaniola.

A new fossil cricket of the genus Proanaxipha in Miocene amber from the Dominican Republic (Orthoptera, Gryllidae, Pentacentrinae).

A new species of the cricket genus Proanaxipha Vickery & Poinar (Orthoptera: Gryllidae: Pentacentrinae) from Early Miocene Dominican amber is described and illustrated. Proanaxipha madgesuttonaesp. n.

Ancient Ephemeroptera-Collembola symbiosis fossilized in amber predicts contemporary phoretic associations.

X-ray computed tomography is used to identify a unique example of fossilized phoresy in 16 million-year-old Miocene Dominican amber involving a springtail being transported by a mayfly. It represents the first evidence (fossil or extant) of phoresy in adult Ephemeroptera and only the second record in Collembola (the first is also preserved in amber). This is the first record of Collembola using winged insects for dispersal.

Summary statistics for fossil spider species taxonomy.

Spiders (Araneae) are one of the most species-rich orders on Earth today, and also have one of the longest geological records of any terrestrial animal groups, as demonstrated by their extensive fossil record. There are currently around 1150 described fossil spider species, representing 2.6% of all described spiders (i.

A minute fossil phoretic mite recovered by phase-contrast X-ray computed tomography.

High-resolution phase-contrast X-ray computed tomography (CT) reveals the phoretic deutonymph of a fossil astigmatid mite (Acariformes: Astigmata) attached to a spider's carapace (Araneae: Dysderidae) in Eocene (44-49 Myr ago) Baltic amber. Details of appendages and a sucker plate were resolved, and the resulting three-dimensional model demonstrates the potential of tomography to recover morphological characters of systematic significance from even the tiniest amber inclusions without the need for a synchrotron. Astigmatids have an extremely sparse palaeontological record.

Computed tomography recovers data from historical amber: an example from huntsman spiders.

Computed tomography (CT) methods were applied to a problematic fossil spider (Arachnida: Araneae) from the historical Berendt collection of Eocene (ca. 44-49 Ma) Baltic amber. The original specimens of Ocypete crassipes Koch and Berendt 1854 are in dark, oxidised amber and the published descriptions lack detail.

Genetic variation in a tropical tree species influences the associated epiphytic plant and invertebrate communities in a complex forest ecosystem.

Genetic differences among tree species, their hybrids and within tree species are known to influence associated ecological communities and ecosystem processes in areas of limited species diversity. The extent to which this same phenomenon occurs based on genetic variation within a single tree species, in a diverse complex ecosystem such as a tropical forest, is unknown. The level of biodiversity and complexity of the ecosystem may reduce the impact of a single tree species on associated communities.

Fossil spiders.

Over the last three decades, the fossil record of spiders has increased from being previously biased towards Tertiary ambers and a few dubious earlier records, to one which reveals a much greater diversity in the Mesozoic, with many of the modern families present in that era, and with clearer evidence of the evolutionary history of the group. We here record the history of palaeoarachnology and the major breakthroughs which form the basis of studies on fossil spiders. Understanding the preservation and taphonomic history of spider fossils is crucial to interpretation of fossil spider morphology.

Human health risk assessment of long chain alcohols.

Representative chemicals from the long chain alcohols category have been extensively tested to define their toxicological hazard properties. These chemicals show low acute and repeat dose toxicity with high-dose effects (if any) related to minimal liver toxicity. These chemicals do not show evidence of activity in genetic toxicity tests or to the reproductive system or the developing organism.

Oldest true orb-weaving spider (Araneae: Araneidae).

The aerial orb web woven by spiders of the family Araneidae typifies these organisms to laypersons and scientists alike. Here we describe the oldest fossil species of this family, which is preserved in amber from Alava, Spain and represents the first record of Araneidae from the Lower Cretaceous. The fossils provide direct evidence that all three major orb web weaving families: Araneidae, Tetragnathidae and Uloboridae had evolved by this time, confirming the antiquity of the use of this remarkable structure as a prey capture strategy by spiders.

Comparing amber fossil assemblages across the Cenozoic.

To justify faunistic comparisons of ambers that differ botanically, geographically and by age, we need to determine that resins sampled uniformly. Our pluralistic approach, analysing size distributions of 671 fossilized spider species from different behavioural guilds, demonstrates that ecological information about the communities of two well-studied ambers is retained. Several lines of evidence show that greater structural complexity of Baltic compared to Dominican amber trees explains the presence of larger web-spinners.

Portal vein thrombosis: an unusual complication of laparoscopic cholecystectomy.

Background: Complications following laparoscopic cholecystectomy are encountered infrequently due to increasing proficiency in laparoscopic surgery. The occurrence of portal venous thrombosis following laparoscopic cholecystectomy has not been previously described and forms the basis of this report.

Methods: A healthy, 32-year-old, female on oral contraceptives underwent an uneventful laparoscopic cholecystectomy for symptomatic gallbladder disease.

Scholarly activities--essential to surgical education.

Research and scholarship are an integral part of a surgical residency program. A concerted effort by a Director of Surgical Research and a Residency Program Director at the community hospital were successful in addressing this very important part of medical education. A questionnaire was designed and data gathered on the attitudes and involvement toward research activities of graduates over the past 6 years.

Resistance of spiders to Cretaceous-Tertiary extinction events.

Throughout Earth history a small number of global catastrophic events leading to biotic crises have caused mass extinctions. Here, using a technique that combines taxonomic and numerical data, we consider the effects of the Cenomanian-Turonian and Cretaceous-Tertiary mass extinctions on the terrestrial spider fauna in the light of new fossil data. We provide the first evidence that spiders suffered no decline at the family level during these mass extinction events.

Embryo-fetal developmental and reproductive toxicology of vinyl chloride in rats.

Vinyl chloride (VC) exposure is primarily via inhalation in the workplace. The primary target organ of VC toxicity is the liver and occupational exposure to VC leads to hepatic angiosarcoma. However, based on epidemiological studies, researchers have been unable to ascertain the effect of occupational VC exposure on embryo-fetal development or reproductive function.