(Table 2) Aragonite, high and low magnesium calcite, major elements, bioclast and planktic foraminifera from ODP Hole 133-817A

Investigation of the Middle Miocene-Pleistocene succession in cores at ODP Site 817A (Leg 133), drilled on the slope south of the Queensland Plateau, identified the various material fluxes contributing to sedimentation and has determined thereby the paleogeographic events which occurred close to the studied area and influenced these fluxes. To determine proportions of platform origin and of plankton origin of carbonate mud, two reference sediments were collected: (1) back-reef carbonate mud from the Young Reef area (Great Barrier Reef); and (2) Late Miocene chalk from the Loyalty Basin, off New Caledonia. Through their biofacies and mineralogical and geochemical characters, these reference sediments were used to distinguish the proportions of platform and basin components in carbonate muds of 25 core samples from Hole 817A. Two "origin indexes" (i1 and i2) relate the proportion in platform and basin materials. The relative sedimentation rate is inferred from the high-frequency cycles determined by redox intervals in the cores. Bulk carbonate deposited in each core has been calculated in two ways with close results: (1) from calcimetric data available in the Leg 133 preliminary reports (Davies et al., 1991); and (2) from average magnetic susceptibility of cores, a value negatively correlated to the average carbonate content. Vertical changes in sedimentation rates, in carbonate content, in origin indexes and in "linear fluxes" document the evolution of sediment origins from platform carbonates, planktonic carbonates and insoluble material through time. These data are augmented with the variations in organic-matter content through the 817A succession. The observed changes and their interpretation are not modified by compaction, and are compatible with major paleogeographic events including drowning of the Queensland Plateau (Middle Miocene-Early Pliocene) and the renewal of shallow carbonate production, (1) during the Late Pliocene, and (2) from the Early Pleistocene. The birth and growth of the Great Barrier Reef is also recorded from 0.5 Ma by a strengthening of detrital carbonate deposition and possibly by a lack of clay minerals in the 4 upper cores, a response to trapping of terrigenous material behind this barrier. In addition, a maximum of biological silica production is displayed in the Middle Miocene. These changes constrain the time of events and the sequence-stratigraphy framework some components of which are transgression surface, maximum flooding surface and low-stand turbidites. Sedimentation rates and material fluxes show cycles lasting 1.75 Myr. Whatever their origin (climatic and/or eustatic) these cycles affected the planktonic production primarily. The changes also show that major carbonate variations in the deposits are due to a dilution effect by insoluble material (clay, biogenic silica and volcanic glasses) and that plankton productivity, controlling the major fraction of carbonate sedimentation, depends principally on terrigenous supplies, but also on deep-water upwelling. Accuracy of the method is reduced by redeposition, reworking, and probable occurrence of hiatuses.

To the Central African lakes and back: the narrative of the Royal geographical society's East Central African expedition, 1878-80.

Mode of access: Internet.

Problems of American civilization, their practical solution the pressing Christian duty of today

First published in National perils and opportunities, discussions of the general Christian conference held in Washington, D.C., 1887 under the auspices of the Evangelical alliance for the United States. New York,1887.

A review of the first year's experience with an automatic message-routing system for low-cost telemedicine

The Swinfen Charitable Trust has used email for some years as a low-cost telemedicine medium to provide consultant support for doctors in developing countries. A scalable, automatic message-routing system was constructed which automates many of the tasks involved in message handling. During the first 12 months of its use, 1510 messages were processed automatically. There were 128 referrals from 18 hospitals in nine countries. Of these 128 queries, 89 (70%) were replied to within 72 h; the median delay was 1.1 day. The 39 unanswered queries were sent to backup specialists for reply and 36 of them (92%) were replied to within 72 h. In the remaining three cases, a second-line (backup) specialist was required. The referrals were handled by 54 volunteer specialists from a panel of over 70. Two system operators, located 10 time zones apart, managed the system. The median time from receipt of a new referral to its allocation to a specialist was 0.2 days (interquartile range, IQR, 0.1-0.8). The median interval between receipt of a new referral and first reply was 2.6 days (IQR 0.8-5.9). Automatic message handling solves many of the problems of manual email telemedicine systems and represents a potentially scalable way of doing low-cost telemedicine in the developing world.

Disorders of breathing and continence have a stronger association with back pain than obesity and physical activity

Although obesity and physical activity have been argued to predict back pain, these factors are also related to incontinence and breathing difficulties. Breathing and continence mechanisms may interfere with the physiology of spinal control, and may provide a link to back pain. The aim of this study was to establish the association between back pain and disorders of continence and respiration in women. We conducted a cross-sectional analysis of self-report, postal survey data from the Australian Longitudinal Study on Women's Health. We used multinomial logistic regression to model four levels of back pain in relation to both the traditional risk factors of body mass index and activity level, and the potential risk factors of incontinence, breathing difficulties, and allergy. A total of 38 050 women were included from three age-cohorts. When incontinence and breathing difficulties were considered, obesity and physical activity were not consistently associated with back pain. In contrast, odds ratios (OR) for often having back pain were higher for women often having incontinence compared to women without incontinence (OR were 2.5, 2.3 and 2.3 for young, mid-age! and older women, respectively). Similarly, mid-aged and older women had higher odds of having back pain often when they experienced breathing difficulties often compared to women with no breathing problems (OR of 2.0 and 1.9, respectively). Unlike obesity and physical activity, disorders of continence and respiration were strongly related to frequent back pain. This relationship may be explained by physiological limitations of co-ordination of postural, respiratory and continence functions of trunk muscles.

Recent developments on a nearshore, terrigenous-influenced reef: Low Isles Reef, Australia

Low Isles Reef is the most southerly located of 46 coral reef platforms unique to the inner shelf of the northern Great Barrier Reef Province, Australia, which support both sea grass and mangrove growth. Such reefs develop in areas that are influenced by river flood plumes and where interreef sediments are dominated by terrigenous mud. Low Isles Reef has long been a popular tourist destination. Informal reports of decreasing visibility, a decline in scleractinian corals, and increases in soft coral and macroalgae have sparked speculation that agricultural activities in coastal catchments are affecting the reef. Comparison of the modern surface of Low Isles Reef with historical surveys and photographs dating back to 1928 allows quantification of modern sedimentary processes, rates of change, and factors influencing reef development. Results indicate that changes on Low Isles Reef are related to remobilization of coarse sediment during storm events and gradual shoreline retreat associated with rising sea level. Retreat of shingle ramparts and elongate ridges of coral debris toward the reef interior has led to the infilling of subtidal ponds on the reef top, which supported hard coral colonies in 1928. The gradual development of a composite shingle rampart along the windward margin has promoted an increase (;150%) in the area of the reef top covered by mangroves. On the leeward margin, a decrease in hard corals since 1950 may reflect a rising contribution of organic debris from the expanding mangrove swamp. Results suggest that recent changes on Low Isles Reef can be explained in the context of natural processes. Further study is needed before the effects of agricultural activities in coastal catchments on reef health can be confirmed.

Interaction of psychosocial risk factors explain increased neck problems among female office workers

This study investigated the relationship between psychosocial risk factors and (1) neck symptoms and (2) neck pain and disability as measured by the neck disability index (NDI). Female office workers employed in local private and public organizations were invited to participate, with 333 completing a questionnaire. Data were collected on various risk factors including age, negative affectivity, history of previous neck trauma, physical work environment, and task demands. Sixty-one percent of the sample reported neck symptoms lasting greater than 8 days in the last 12 months. The mean NDI of the sample was 15.5 out of 100, indicating mild neck pain and disability. In a hierarchical multivariate logistic regression, low supervisor support was the only psychosocial risk factor identified with the presence of neck symptoms. Similarly, low supervisor support was the only factor associated with the score on the NDI. These associations remained after adjustment for potential confounders of age, negative affectivity, and physical risk factors. The interaction of job demands, decision authority, and supervisor support was significantly associated with the NDI in the final model and this association increased when those with previous trauma were excluded. Interestingly, and somewhat contrary to initial expectations, as job demands increased, high decision authority had an increasing effect on the NDI when supervisor support was low. Crown copyright (c) 2006 Published by Elsevier B.V. All rights reserved.

Design and implementation of an automatic message-routing system for low-cost telemedicine

Email has been used for some years as a low-cost telemedicine medium to provide support for developing countries. However, all operations have been relatively small scale and fairly labour intensive to administer. A scalable, automatic message-routing system was constructed which automates many of the tasks. During a four-month study period in 2002, 485 messages were processed automatically. There were 31 referrals from eight hospitals in three countries. These referrals were handled by 25 volunteer specialists from a panel of 42. Two system operators, located 10 time zones apart, managed the system. The median time from receipt of a new referral to its allocation to a specialist was 1.0 days (interquartile range 0.7-2.4). The median interval between allocation and first reply was 0.7 days (interquartile range 0.3-2.3). Automatic message handling solves many of the problems of manual email telemedicine systems and represents a potentially scalable way of doing low-cost telemedicine in the developing world.

ANÁLISE DAS MUDANÇAS DOS FATORES DETERMINANTES DA ESTRUTURA DE CAPITAL EM FUNÇÃO DO CICLO DE VIDA DAS EMPRESAS BRASILEIRAS SÃO BERNARDO DO CAMPO

As várias teorias acerca da estrutura de capital despertam interesse motivando diversos estudos sobre o assunto sem, no entanto, ter um consenso. Outro tema aparentemente pouco explorado refere-se ao ciclo de vida das empresas e como ele pode influenciar a estrutura de capital. Este estudo teve como objetivo verificar quais determinantes possuem maior relevância no endividamento das empresas e se estes determinantes alteram-se dependendo do ciclo de vida da empresa apoiada pelas teorias Trade Off, Pecking Order e Teoria da Agência. Para alcançar o objetivo deste trabalho foi utilizado análise em painel de efeito fixo sendo a amostra composta por empresas brasileiras de capital aberto, com dados secundários disponíveis na Economática® no período de 2005 a 2013, utilizando-se os setores da BM&FBOVESPA. Como resultado principal destaca-se o mesmo comportamento entre a amostra geral, alto e baixo crescimento pelo endividamento contábil para o determinante Lucratividade apresentando uma relação negativa, e para os determinantes Oportunidade de Crescimento e Tamanho, estes com uma relação positiva. Para os grupos de alto e baixo crescimento alguns determinantes apresentaram resultados diferentes, como a singularidade que resultou significância nestes dois grupos, sendo positiva no baixo crescimento e negativa no alto crescimento, para o valor colateral dos ativos e benefício fiscal não dívida apresentaram significância apenas no grupo de baixo crescimento. Para o endividamento a valor de mercado foi observado significância para o Benefício fiscal não dívida e Singularidade. Este resultado reforça o argumento de que o ciclo de vida influência a estrutura de capital

Statistical mechanics of low-density parity-check codes

We review recent theoretical progress on the statistical mechanics of error correcting codes, focusing on low-density parity-check (LDPC) codes in general, and on Gallager and MacKay-Neal codes in particular. By exploiting the relation between LDPC codes and Ising spin systems with multispin interactions, one can carry out a statistical mechanics based analysis that determines the practical and theoretical limitations of various code constructions, corresponding to dynamical and thermodynamical transitions, respectively, as well as the behaviour of error-exponents averaged over the corresponding code ensemble as a function of channel noise. We also contrast the results obtained using methods of statistical mechanics with those derived in the information theory literature, and show how these methods can be generalized to include other channel types and related communication problems.

The boundary lubricated friction and wear of low alloy steel

Pin on disc wear machines were used to study the boundary lubricated friction and wear of AISI 52100 steel sliding partners. Boundary conditions were obtained by using speed and load combinations which resulted in friction coefficients in excess of 0.1. Lubrication was achieved using zero, 15 and 1000 ppm concentrations of an organic dimeric acid additive in a hydrocarbon base stock. Experiments were performed for sliding speeds of 0.2, 0.35 and 0.5 m/s for a range of loads up to 220 N. Wear rate, frictional force and pin temperature were continually monitored throughout tests and where possible complementary methods of measurement were used to improve accuracy. A number of analytical techniques were used to examine wear surfaces, debris and lubricants, namely: Scanning Electron Microscopy (SEM), Auger Electron Spectroscopy (AES), Powder X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), optical microscopy, Back scattered Electron Detection (BSED) and several metallographic techniques. Friction forces and wear rates were found to vary linearly with load for any given combination of speed and additive concentration. The additive itself was found to act as a surface oxidation inhibitor and as a lubricity enhancer, particularly in the case of the higher (1000 ppm) concentration. Wear was found to be due to a mild oxidational mechanism at low additive concentrations and a more severe metallic mechanism at higher concentrations with evidence of metallic delamination in the latter case. Scuffing loads were found to increase with increasing additive concentration and decrease with increasing speed as would be predicted by classical models of additive behaviour as an organo-metallic soap film. Heat flow considerations tended to suggest that surface temperature was not the overriding controlling factor in oxidational wear and a model is proposed which suggests oxygen concentration in the lubricant is the controlling factor in oxide growth and wear.

Surface acoustic wave devices with low loss and high frequency operation

This thesis describes an industrial research project carried out in collaboration with STC Components, Harlow, Essex. Technical and market trends in the use of surface acoustic wave (SAW) devices are reviewed. As a result, three areas not previously addressed by STC were identified: lower insertion loss designs, higher operating frequencies and improved temperature dependent stability. A review of the temperature performance of alternative lower insertion loss designs,shows that greater use could be made of the on-site quartz growing plant. Data is presented for quartz cuts in the ST-AT range. This data is used to modify the temperature performance of a SAW filter. Several recently identified quartz orientations have been tested. These are SST, LST and X33. Problems associated with each cut are described and devices demonstrated. LST quartz, although sensitive to accuracy of cut, is shown to have an improved temperature coefficient over the normal ST orientation. Results show that its use is restricted due to insertion loss variations with temperature. Effects associated with split-finger transducers on LST-quartz are described. Two low-loss options are studied, coupled resonator filters for very narrow bandwidth applications and single phase unidirectional transducers (SPUDT) for fractional bandwidths up to about 1%. Both designs can be implemented with one quarter wavelength transducer geometries at operating frequencies up to 1GHz. The SPUDT design utilised an existing impulse response model to provide analysis of ladder or rung transducers. A coupled resonator filter at 400MHz is demonstrated with a matched insertion loss of less than 3.5dB and bandwidth of 0.05%. A SPUDT device is designed as a re-timing filter for timing extraction in a long haul PCM transmission system. Filters operating at 565MHz are demonstrated with insertion losses of less than 6dB. This basic SPUDT design is extended to a maximally distributed version and demonstrated at 450MHz with 9.8dB insertion loss.

A constructive learning algorithm based on back-propagation

There are been a resurgence of interest in the neural networks field in recent years, provoked in part by the discovery of the properties of multi-layer networks. This interest has in turn raised questions about the possibility of making neural network behaviour more adaptive by automating some of the processes involved. Prior to these particular questions, the process of determining the parameters and network architecture required to solve a given problem had been a time consuming activity. A number of researchers have attempted to address these issues by automating these processes, concentrating in particular on the dynamic selection of an appropriate network architecture.The work presented here specifically explores the area of automatic architecture selection; it focuses upon the design and implementation of a dynamic algorithm based on the Back-Propagation learning algorithm. The algorithm constructs a single hidden layer as the learning process proceeds using individual pattern error as the basis of unit insertion. This algorithm is applied to several problems of differing type and complexity and is found to produce near minimal architectures that are shown to have a high level of generalisation ability.