Worn Down and Worn Out

Exposure to early adversity, particularly dire poverty, can powerfully shape the life course of a young person. As a city and region, we continually choose whether we’ll commit ourselves to an alternative course

Lithostratigraphy, sedimentation and evolution of the Volta Basin in Ghana

We present a revised lithostratigraphy for the Voltaian Supergroup of Ghana, based on a review of existing literature, interpretations of remotely sensed data and reconnaissance field survey of the Volta Basin. These strata thicken eastwards, to a maximum of between 5 and 6 km adjacent to the Pan-African Dahomeyide orogen. They began to accumulate some time after about 1000 Ma, along the margin of an epicontinental sea. Initial sedimentation, comprising the age-equivalent Kwahu and Bombouaka Groups, shows a cyclical mode of deposition controlled by eustatic changes in sea-level that produced a range of nearshore marine, littoral and terrestrial environments. A major erosional interval was followed by deposition of the 3–4 km thick Oti-Pendjari Group. Basal tillites and associated sandy diamictons are correlated with the Marinoan (end-Cryogenian) glaciation, indicating a maximum depositional age of about 635 Ma. The overlying cap carbonates and tuffs were deposited within a shallow epeiric sea bordered by a volcanically active rift system. The main part of the group records the transition from a rifted passive margin to a fully developed foreland basin receiving marine flysch in the form of argillaceous strata interbedded with highly immature wacke-type sandstones and conglomerates. Maximum accommodation space was developed within a foredeep adjacent to the Dahomeyide belt. Towards the end of the orogenic phase, the foredeep succession became partially inverted and then was buried under coarse terrestrial, red-bed molasse of the Obosum Group

Dermal fin rays and scales derive from mesoderm, not neural crest

SummaryNeural crest cells disperse throughout the embryonic head to generate diverse cell types of two classes: non-ectomesenchymal (including melanocytes, peripheral neurons and glia) and ectomesenchymal (skeletogenic, odontogenic, cartilaginous and connective tissue cell fates). In contrast to cranial neural crest, trunk neural crest of amniotes generates only non-ectomesenchymal cell types. Anamniote trunk neural crest, however, has been assumed to generate derivatives of both classes, including osteoblasts of dermal skeletal elements, which includes scales and fin rays. Through genetic lineage tracing in zebrafish, we present the first test of this assumption and find that trunk neural crest does not generate fin osteoblasts; rather, these derive from a late emerging population of paraxial mesoderm. Similarly we show that the mineralising cells of the scales are mesodermally derived, with no contribution from neural crest. Our data suggest that trunk/tail exoskeletal structures evolved through deployment of mesodermally derived mesenchyme, rather than neural crest

Cockpit Text Communications: Evaluating the Efficiency and Accuracy of Different Keyboards

Non-voice data exchanges will become a primary method of communication between pilots and Air Traffic Controllers as the Federal Aviation Administration’s plan for the Next Generation Air Traffic Control System (NextGen) evolves. In support of this communication evolution, pilots will need the most efficient interface tools in order to accurately and quickly exchange text messages with Air Traffic Control. Keyboards, or similar input devices, will be become a necessity in the cockpit. This study aims to investigate and compare the typing speed and accuracy possible using three sizes of two-hand, QWERTY1 keyboards: a full size (100%), a medium size (92%), and a small size (thumb typing home theater PC keyboard) that could be used for aviation data exchanges. Each study participant was administered 15 typing tests having aviation specific content, on each keyboard, including 5 tests of short length, 5 tests of medium length, and 5 tests of long length. The results of this study suggest that in terms of words per minute typing speed, participants using the medium size keyboard had a slightly faster typing speed than with the large keyboard, while the small keyboard produced a considerably slower typing speed than either the medium or large keyboards. In terms of accuracy, participants using the small keyboard had the highest level of accuracy, followed by the medium keyboard, while the least accurate keyboard tended to be the large keyboard. Overall, findings suggest that the optimal size of two-handed, QWERTY keyboard for use in an aircraft cockpit was the medium keyboard

Cockpit Text Communications: Evaluating the Efficiency and Accuracy

Non-voice data exchanges will become a primary method of communication between pilots and Air Traffic Controllers as the Federal Aviation Administration’s plan for the Next Generation Air Traffic Control System (NextGen) evolves. In support of this communication evolution, pilots will need the most efficient interface tools in order to accurately and quickly exchange text messages with Air Traffic Control. Keyboards, or similar input devices, will be become a necessity in the cockpit. This study aims to investigate and compare the typing speed and accuracy possible using three sizes of two-hand, QWERTY1 keyboards: a full size (100%), a medium size (92%), and a small size (thumb typing home theater PC keyboard) that could be used for aviation data exchanges. Each study participant was administered 15 typing tests having aviation specific content, on each keyboard, including 5 tests of short length, 5 tests of medium length, and 5 tests of long length. The results of this study suggest that in terms of words per minute typing speed, participants using the medium size keyboard had a slightly faster typing speed than with the large keyboard, while the small keyboard produced a considerably slower typing speed than either the medium or large keyboards. In terms of accuracy, participants using the small keyboard had the highest level of accuracy, followed by the medium keyboard, while the least accurate keyboard tended to be the large keyboard. Overall, findings suggest that the optimal size of two-handed, QWERTY keyboard for use in an aircraft cockpit was the medium keyboard

The Epithelial Cell Adhesion Molecule EpCAM Is Required for Epithelial Morphogenesis and Integrity during Zebrafish Epiboly and Skin Development

The aberrant expression of the transmembrane protein EpCAM is associated with tumor progression, affecting different cellular processes such as cell–cell adhesion, migration, proliferation, differentiation, signaling, and invasion. However, the in vivo function of EpCAM still remains elusive due to the lack of genetic loss-of-function studies. Here, we describe epcam (tacstd) null mutants in zebrafish. Maternal-zygotic mutants display compromised basal protrusive activity and epithelial morphogenesis in cells of the enveloping layer (EVL) during epiboly. In partial redundancy with E-cadherin (Ecad), EpCAM made by EVL cells is further required for cell–cell adhesion within the EVL and, possibly, for proper attachment of underlying deep cells to the inner surface of the EVL, thereby also affecting deep cell epiboly movements. During later development, EpCAM per se becomes indispensable for epithelial integrity within the periderm of the skin, secondarily leading to disrupted morphology of the underlying basal epidermis and moderate hyper-proliferation of skin cells. On the molecular level, EVL cells of epcam mutant embryos display reduced levels of membranous Ecad, accompanied by an enrichment of tight junction proteins and a basal extension of apical junction complexes (AJCs). Our data suggest that EpCAM acts as a partner of E-cadherin to control adhesiveness and integrity as well as plasticity and morphogenesis within simple epithelia. In addition, EpCAM is required for the interaction of the epithelia with underlying cell layers

Halothane hepatitis with renal failure treated with hemodialysis and exchange transfusion

A 38-year-old white female, hepatitis B antigen negative, developed fluminating hepatic failure associated with oliguria and severe azotemia after two halothane anesthesia and without exposure to other hepatotoxic drugs or blood transfusions. She was treated with multiple hemodialysis and exchange blood transfusion. The combined treatment corrected the uremic abnormalities and improved her level of consciousness. The liver and kidney function gradually improved, and she made a complete recovery, the first recorded with hepatic and renal failure under these post-anesthetic conditions. Further evaluation of this combined treatment used for this patient is warranted. © 1974 The Japan Surgical Society