Contributions to medical and biological research, dedicated to Sir William Osler, bart., M.D., F.R.S., in honour of his seventieth birthday, June 12, 1919,

Paged continuously.

Selected letters of William Bright, D.D.; regius professor of ecclesiastical history in the University of Oxford; canon of Christ church.

Includes bibliographical references.

A memoir of the Right Hon. William Edward Hartpole Lecky, M.P., O.M., LL. D., D.C.L., LITT. D., member of the French Institute and of the British Academy,

Mode of access: Internet.

The works of William E. Channing, D. D.

Includes bibliographical references.

The English, Scotch and Irish historical libraries. Giving a short view and character of most of our historians, either in print or manuscript. With an account of our records, lawbooks, coins, &c. by W. Nicolson, late bishop of Carlisle. To which is added, A letter to the Reverend White Kennet, D. D., in defence of the English historical library, &c.

The letter to Kennett is a reply to Francis Atterbury.

Acetilação do exopolissacarídeo (1→6)-β-D-glucana (lasiodiplodana): derivatização química e caracterização

Lasiodiplodan is an exocellular β-glucan with biological functionalities such as antioxidant, antiproliferative, hypocholesterolemic, protective activity against DNA damage induced by doxorubicin and hypoglycemic activity. Chemical derivatization of polysaccharide macromolecules has been considered as a potentiating mechanism for bioactivity. In this context, this work proposes the derivatization of lasiodiplodan by acetylation. Acetic anhydride was used as derivatizing agent and pyridine as catalyst and reaction medium. The derivatives obtained were evaluated by its water solubility, degree of substitution (DS), antioxidant potential, and characterized by infrared spectroscopy (FT-IR), thermal analysis, differential scanning calorimetry, X-ray diffraction and scanning electron microscopy. Acetylated derivatives with different degrees of substitution (1.26; 1.03; 0.66 and 0.48) were obtained, and there was correlation between the concentration of derivatizing agent and DS. FT-IR spectroscopy analysis confirmed the insertion of acetyl groups into derivatized macromolecules (LAS-AC) through of specific bands concerning to carbonyl group (C = O) and increase in C-O vibration. SEM analysis indicated that native lasiodiplodan presents morphological structure in the form of thin films with translucent appearance and folds along its length. Derivatization led to morphological changes in the polymer, including aspects thickness, translucency and agglomeration. Thermal analysis indicated the native sample and derivative with DS 0.48 presented three weight loss stages. The first stage occurred until 125 ° C (loss of water) and there were two consecutive events of weight loss (200 ° C - 400 ° C) attributed to molecule degradation. Samples with DS 1.26; 1.03 and 0.66 demonstrated four weight loss stages. The first stage occurred until 130 ° C (loss of water), following by two consecutive events of weight loss (200 ° C - 392 ° C) attributed to degradation of the biopolymer. The fourth stage was between 381 ° C and 532 ° C (final decomposition) with exothermic peaks between 472 ° C and 491 ° C. X-ray diffraction patterns showed that native and acetylated lasiodiplodan have amorphous structure with semicrystalline regions. Derivatization did not contribute to increased solubility of the macromolecule, but potentiated its antioxidant capacity. Acetylation of lasiodiplodan allowed to obtaining a new macromolecule with higher antioxidant potential than the native molecule and with technological properties applicable in various industrial sectors.

Elucidating the links between UV radiation and vitamin D synthesis : using an in vitro model

Ultraviolet radiation (UV) is the carcinogen that causes the most common malignancy in humans – skin cancer. However, moderate UV exposure is essential for producing vitaminDin our skin. VitaminDincreases the absorption of calcium from the diet, and adequate calcium is necessary for the building and maintenance of bones. Thus, low levels of vitamin D can cause osteomalacia and rickets and contribute to osteoporosis. Emerging evidence also suggests vitamin D may protect against falls, internal cancers, psychiatric conditions, autoimmune diseases and cardiovascular diseases. Since the dominant source of vitamin D is sunlight exposure, there is a need to understand what is a “balanced��� level of sun exposure to maintain an adequate level of vitamin D but minimise the risks of eye damage, skin damage and skin cancer resulting from excessive UV exposure. There are many steps in the pathway from incoming solar UV to the eventual vitamin D status of humans (measured as 25-hydroxyvitamin D in the blood), and our knowledge about many of these steps is currently incomplete. This project begins by investigating the levels of UV available for synthesising vitamin D, and how these levels vary across seasons, latitudes and times of the day. The thesis then covers experiments conducted with an in vitro model, which was developed to study several aspects of vitamin D synthesis. Results from the model suggest the relationship between UV dose and vitamin D is not linear. This is an important input into public health messages regarding ‘safe’ UV exposure: larger doses of UV, beyond a certain limit, may not continue to produce vitamin D; however, they will increase the risk of skin cancers and eye damage. The model also showed that, when given identical doses of UV, the amount of vitamin D produced was impacted by temperature. In humans, a temperature-dependent reaction must occur in the top layers of human skin, prior to vitamin D entering the bloodstream. The hypothesis will be raised that cooler temperatures (occurring in winter and at high latitudes) may reduce vitamin D production in humans. Finally, the model has also been used to study the wavelengths of UV thought to be responsible for producing vitamin D. It appears that vitamin D production is limited to a small range of UV wavelengths, which may be narrower than previously thought. Together, these results suggest that further research is needed into the ability of humans to synthesise vitamin D from sunlight. In particular, more information is needed about the dose-response relationship in humans and to investigate the proposed impact of temperature. Having an accurate action spectrum will also be essential for measuring the available levels of vitamin D-effective UV. As this research continues, it will contribute to the scientific evidence-base needed for devising a public health message that will balance the risks of excessive UV exposure with maintaining adequate vitamin D.

Reply to William B. Grant

THE UVI working group acknowledges the contribution of Vitamin D to bone health as stated in our paper. However, we concluded that an optimal level of Vitamin D for humans has not yet been established with any certainty...

The role of 25-hydroxyvitamin D deficiency in promoting insulin resistance and inflammation in patients with chronic kidney disease: A randomised controlled trial

BACKGROUND Approximately 50% of patients with stage 3 Chronic Kidney Disease are 25-hydroxyvitamin D insufficient, and this prevalence increases with falling glomerular filtration rate. Vitamin D is now recognised as having pleiotropic roles beyond bone and mineral homeostasis, with the vitamin D receptor and metabolising machinery identified in multiple tissues. Worryingly, recent observational data has highlighted an association between hypovitaminosis D and increased cardiovascular mortality, possibly mediated via vitamin D effects on insulin resistance and inflammation. The main hypothesis of this study is that oral Vitamin D supplementation will ameliorate insulin resistance in patients with Chronic Kidney Disease stage 3 when compared to placebo. Secondary hypotheses will test whether this is associated with decreased inflammation and bone/adipocyte-endocrine dysregulation. METHODS/DESIGN This study is a single-centre, double-blinded, randomised, placebo-controlled trial. Inclusion criteria include; estimated glomerular filtration rate 30-59 ml/min/1.73 m(2); aged >or=18 on entry to study; and serum 25-hydroxyvitamin D levels <75 nmol/L. Patients will be randomised 1:1 to receive either oral cholecalciferol 2000IU/day or placebo for 6 months. The primary outcome will be an improvement in insulin sensitivity, measured by hyperinsulinaemic euglycaemic clamp. Secondary outcome measures will include serum parathyroid hormone, cytokines (Interleukin-1beta, Interleukin-6, Tumour Necrosis Factor alpha), adiponectin (total and High Molecular Weight), osteocalcin (carboxylated and under-carboxylated), peripheral blood mononuclear cell Nuclear Factor Kappa-B p65 binding activity, brachial artery reactivity, aortic pulse wave velocity and waveform analysis, and indirect calorimetry. All outcome measures will be performed at baseline and end of study. DISCUSSION To date, no randomised controlled trial has been performed in pre-dialysis CKD patients to study the correlation between vitamin D status with supplementation, insulin resistance and markers of adverse cardiovascular risk. We remain hopeful that cholecalciferol may be a safe intervention, with health benefits beyond those related to bone-mineral homeostasis. TRIAL REGISTRATION Australian and New Zealand Clinical Trials Registry ACTRN12609000246280.

Directional dominance on stature and cognition in diverse human populations

Homozygosity has long been associated with rare, often devastating, Mendelian disorders1, and Darwin was one of the first to recognize that inbreeding reduces evolutionary fitness2. However, the effect of the more distant parental relatedness that is common in modern human populations is less well understood. Genomic data now allow us to investigate the effects of homozygosity on traits of public health importance by observing contiguous homozygous segments (runs of homozygosity), which are inferred to be homozygous along their complete length. Given the low levels of genome-wide homozygosity prevalent in most human populations, information is required on very large numbers of people to provide sufficient power3, 4. Here we use runs of homozygosity to study 16 health-related quantitative traits in 354,224 individuals from 102 cohorts, and find statistically significant associations between summed runs of homozygosity and four complex traits: height, forced expiratory lung volume in one second, general cognitive ability and educational attainment (P < 1 × 10−300, 2.1 × 10−6, 2.5 × 10−10 and 1.8 × 10−10, respectively). In each case, increased homozygosity was associated with decreased trait value, equivalent to the offspring of first cousins being 1.2 cm shorter and having 10 months’ less education. Similar effect sizes were found across four continental groups and populations with different degrees of genome-wide homozygosity, providing evidence that homozygosity, rather than confounding, directly contributes to phenotypic variance. Contrary to earlier reports in substantially smaller samples5, 6, no evidence was seen of an influence of genome-wide homozygosity on blood pressure and low density lipoprotein cholesterol, or ten other cardio-metabolic traits. Since directional dominance is predicted for traits under directional evolutionary selection7, this study provides evidence that increased stature and cognitive function have been positively selected in human evolution, whereas many important risk factors for late-onset complex diseases may not have been.

Averting biodiversity collapse in tropical forest protected areas

The rapid disruption of tropical forests probably imperils global biodiversity more than any other contemporary phenomenon(1-3). With deforestation advancing quickly, protected areas are increasingly becoming final refuges for threatened species and natural ecosystem processes. However, many protected areas in the tropics are themselves vulnerable to human encroachment and other environmental stresses(4-9). As pressures mount, it is vital to know whether existing reserves can sustain their biodiversity. A critical constraint in addressing this question has been that data describing a broad array of biodiversity groups have been unavailable for a sufficiently large and representative sample of reserves. Here we present a uniquely comprehensive data set on changes over the past 20 to 30 years in 31 functional groups of species and 21 potential drivers of environmental change, for 60 protected areas stratified across the world's major tropical regions. Our analysis reveals great variation in reserve `health': about half of all reserves have been effective or performed passably, but the rest are experiencing an erosion of biodiversity that is often alarmingly widespread taxonomically and functionally. Habitat disruption, hunting and forest-product exploitation were the strongest predictors of declining reserve health. Crucially, environmental changes immediately outside reserves seemed nearly as important as those inside in determining their ecological fate, with changes inside reserves strongly mirroring those occurring around them. These findings suggest that tropical protected areas are often intimately linked ecologically to their surrounding habitats, and that a failure to stem broad-scale loss and degradation of such habitats could sharply increase the likelihood of serious biodiversity declines.

Scale-dependent relationships between tree species richness and ecosystem function in forests

1. The relationship between species richness and ecosystem function, as measured by productivity or biomass, is of long-standing theoretical and practical interest in ecology. This is especially true for forests, which represent a majority of global biomass, productivity and biodiversity. 2. Here, we conduct an analysis of relationships between tree species richness, biomass and productivity in 25 forest plots of area 8-50ha from across the world. The data were collected using standardized protocols, obviating the need to correct for methodological differences that plague many studies on this topic. 3. We found that at very small spatial grains (0.04ha) species richness was generally positively related to productivity and biomass within plots, with a doubling of species richness corresponding to an average 48% increase in productivity and 53% increase in biomass. At larger spatial grains (0.25ha, 1ha), results were mixed, with negative relationships becoming more common. The results were qualitatively similar but much weaker when we controlled for stem density: at the 0.04ha spatial grain, a doubling of species richness corresponded to a 5% increase in productivity and 7% increase in biomass. Productivity and biomass were themselves almost always positively related at all spatial grains. 4. Synthesis. This is the first cross-site study of the effect of tree species richness on forest biomass and productivity that systematically varies spatial grain within a controlled methodology. The scale-dependent results are consistent with theoretical models in which sampling effects and niche complementarity dominate at small scales, while environmental gradients drive patterns at large scales. Our study shows that the relationship of tree species richness with biomass and productivity changes qualitatively when moving from scales typical of forest surveys (0.04ha) to slightly larger scales (0.25 and 1ha). This needs to be recognized in forest conservation policy and management.

Caracterización y evaluación preliminar del Teocinte anual (Zea lexurians D.) recolectado en la zona norte de Chinandega, Nicaragua

Este trabajo trata sobre la caracterización y evaluación preliminar del posible ancestro del maíz, el teocintle anual (Zea luxurians Durie), el cual fue recolectado en la región Nor-occidental de Nicaragua (Villanueva, Chinandega). El experimento se llevó a efecto en el área experimental del Programa Recursos Genéticos Nicaragüenses (REGEN), adscrito a la Universidad Nacional Agraria (UNA), ubicado en el Km 12 1/2 carretera Norte. Dicha investigación se realizó en el periodo comprendido de Enero a Octubre de 1995. los meses de Enero y Febrero no fueron evaluados debido al fuerte acame de las plantas, y el mes de Octubre no se evaluó debido al deficiente crecimiento y desarrollo. El diseño empleado fue un bifactorial en parcelas divididas con dos bloques. En las parcelas grandes se ubicaron los tratamientos épocas de siembra (meses), y en las parcelas pequeñas se realizó el control de malezas (con maleza y sin maleza en todo el ciclo de la planta. Se utilizaron 45 descriptores, de los cuales cuantitativos y 11 son cualitativos. Según el realizado se observó diferencia significativa 34 son ANDEVA en los caracteres cuantitativos, a excepción de los caracteres de grano. Las mayores alturas de plantas se obtuvieron en las primeras fechas de siembra, sobrepasando los 3m de altura y en cuanto al rendimiento los mayores promedios se presentaron bajo el tratamiento sin maleza. Esta especie responde al fotoperiodo, ya que la floración se produjo entre los meses de Noviembre y Diciembre para los meses de Enero hasta Septiembre y la época de siembra del mes de Octubre se registró entre Diciembre y Enero. De los resultados obtenidos se elaboró un catálogo (valores máximos,medios, mínimos, desviación estándar y coeficiente de variación para los descriptores cuantitativos) para los diferentes tratamientos.Debido a la importancia que esta especie representa se debe tomar en cuenta la caracterización In situ y declarar zona protegida el área de origen por riesgos de erosión genética.

Symmetrical 2-D Hermite-Gaussian square launch for high bit rate transmission in multimode fiber links

A 2-D Hermite-Gaussian square launch is demonstrated to show improved systems capacity over multimode fiber links. It shows a bandwidth improvement over both center and offset launches and exhibits ±5 μm misalignment tolerance. © 2011 Optical Society of America.

Peuplements zooplanctoniques dans les régions de remontées d'eau du littoral atlantique africain

The introduction is followed by a resume of the biogeographic factors and the principal work. The characteristics of zooplankton in different regions are presented based on regular research in Santa Helena Bay and Walvis Bay and the research carried out by William Scoresby. Certain factors of the digestive system of South African plankton are discussed. The next section concerns research in intertropical and equatorial regions in the Gulf of Guinea. It considers the littoral region of Angola, the Pointe Noire region and discusses the density and complexity of stocks. The last section concerns the zooplankton of Nigeria, Ghana and the Ivory Coast and discusses the grouping of species and compares the results.