Integrative Effects of Vine Water Relations and Grape Ripeness Level of Vitis vinifera L. cv. Shiraz/Richter 99. I. Physiological Changes and Vegetative-Reproductive Growth Balances

The water relations and physiological status of the grapevine are critical for obtaining a quality product andfor fully exploring vineyard and grape potential. The objective of this investigation was to determine theeffect of grapevine water status (induced by means of two field water capacity-based irrigation levels, 75%and 100%, applied at single and combined vine developmental stages) on morphological and physiologicalchanges in Vitis vinifera L. cv. Shiraz/Richter 99 grapevines and grapes (harvested at different solublesolid levels) under field conditions. The integrative effects of vine water relations and grape ripeness level,specifically in a Mediterranean high winter rainfall area, have not yet been investigated systematically. Theterroir affected the reaction of the vines to treatments. The soil displayed high water-holding capacity anda buffer against favourable evapotranspiration conditions, even with a western aspect and being subjectedto long and relatively dry seasons, with frequent occurrence of high temperatures and grapevines withfully developed canopies. The vines did not seem overly stressed – in line with the relatively high basesoil water fractions of mostly more than 50% of field water capacity. Primary and secondary leaf waterpotential and stem water potential displayed similar patterns and the water potential of the primary andsecondary leaves was similar. Despite relatively high base soil water contents that prevented excessivelylow plant water potential and classic leaf and berry behaviour to surface, the vines still responded in anoticeable way to volume and timing of irrigation in relation to the grape ripeness level status. Waterrelations, ripeness level and terroir conditions showed an integrated, steering impact on physiological,vegetative and reproductive behaviour. Post-véraison irrigated vines were expected to maintain relativelyhigh water potential during the last weeks of the ripening period, but this seemed not to be the case. Allvines seemed to have recuperated/stabilised during this time, maintaining their water balances. Physical,physiological and compositional changes in the berry during late ripening under field conditions wereclarified further. New information was obtained on the relationships between the behaviour of the rootsystem, canopy and grapes and the changing terroir conditions during the ripening period

Integrative Effects of Vine Water Relations and Grape Ripeness Level of Vitis vinifera L. cv. Shiraz/Richter 99. II. Grape Composition and Wine Quality

Regulation of grapevine water status is a common practice to manipulate grape composition and winequality. In this investigation the effect of plant water status (two field water capacity-based irrigation levels,75% and 100%, applied at single and combined vine developmental stages) and ripeness level (harvestingat different soluble solid levels) on grape composition and wine quality of Vitis vinifera L. cv. Shiraz/Richter 99 was determined. Integrative effects of vine water relations and grape ripeness level, specificallyin a Mediterranean high winter rainfall area, have not yet been investigated systematically. Source:sinkmechanisms and dynamics and compositional and physical changes during both green berry and ripeningperiods (and in response to environment changes), seemed critical for the final grape composition and winequality/style. Despite relatively favourable conditions of the experiment terroir, additional water was stillrequired to obtain best grape and wine quality. Skin colour and total phenolic contents were stimulated inparticular by 75% (field water capacity) pea size (PS) irrigation, post-véraison (PV) irrigation and 75% peasize+post-véraison irrigation, until the last harvest stage. Treatments that included post-véraison irrigationwere not negative in terms of ripening parameters. Increasing total soluble solids with ripening were notfollowed in parallel by anthocyanin potential. Anthocyanin extractability increased with ripening. A late,overripe harvest may result in wines that are slightly better coloured, but highly alcoholic and tannic.Furthermore, at high ripeness level, differences between treatments largely diminished. Over-ripenessof grapes may have tempering and even negative effects on expected outcomes of seasonal cultivationefforts to produce unique wines. This would not favour economic viability. Although non-irrigated winesfailed to result in exceptional wine quality at any harvest stage, a better result in overall quality wasobtained in comparison to irrigation treatments applied at all stages. Berry and wine composition resultscorresponded with findings on wine sensorial quality. The 75% PS, PV irrigation, and 75% PS+PVirrigation consistently resulted in good quality wines. At the first harvest stage, 75% PV, 100% PV, 75%PS+V and 75% PS+PV irrigations gave most prominent wines; at the second harvest stage, vines irrigated75% at PS, 75% at PS+PV and 75% at PV delivered most prominent wines; and at the third harveststage, 75% PV, 100% PV, 75% PS and 75% PS+PV resulted in most prominent wines. These treatmentsrepresented different wine styles at each harvest stage. Restricted PS irrigation and PV irrigation, as singleor combined treatments, featured prominently in favouring grape and wine composition and wine sensorialquality. Physical and compositional changes in ripening berries and the impact on wine quality and stylewere further clarified. New perspectives on managing time of harvesting with varying vine water status aregiven. Recommendations on vine water status management strategies required to obtain different grapecomposition and wine style are made

Magnetohydrodynamics and Plasma Cosmology

We study the linear magnetohydrodynamic (MHD) equations, both in the Newtonian and the general-relativistic limit, as regards a viscous magnetized fluid of finite conductivity and discuss instability criteria. In addition, we explore the excitation of cosmological perturbations in anisotropic spacetimes, in the presence of an ambient magnetic field. Acoustic, electromagnetic (e/m) and fast-magnetosonic modes, propagating normal to the magnetic field, can be excited, resulting in several implications of cosmological significance.Comment: 9 pages, RevTeX, To appear in the Proceedings of the Peyresq X Meeting, IJTP Conference Serie

The Similarity Hypothesis in General Relativity

Self-similar models are important in general relativity and other fundamental theories. In this paper we shall discuss the ``similarity hypothesis'', which asserts that under a variety of physical circumstances solutions of these theories will naturally evolve to a self-similar form. We will find there is good evidence for this in the context of both spatially homogenous and inhomogeneous cosmological models, although in some cases the self-similar model is only an intermediate attractor. There are also a wide variety of situations, including critical pheneomena, in which spherically symmetric models tend towards self-similarity. However, this does not happen in all cases and it is it is important to understand the prerequisites for the conjecture.Comment: to be submitted to Gen. Rel. Gra

Palaeoenvironmental control on distribution of crinoids in the Bathonian (Middle Jurassic) of England and France

Bulk sampling of a number of different marine and marginal marine lithofacies in the British Bathonian has allowed us to assess the palaeoenvironmental distribution of crinoids for the first time. Although remains are largely fragmentary, many species have been identified by comparison with articulated specimens from elsewhere, whilst the large and unbiased sample sizes allowed assessment of relative proportions of different taxa. Results indicate that distribution of crinoids well corresponds to particular facies. Ossicles of Chariocrinus and Balanocrinus dominate in deeper-water and lower-energy facies,with the former extending further into shallower-water facies than the latter. Isocrinus dominates in shallower water carbonate facies, accompanied by rarer comatulids, and was also present in the more marine parts of lagoons. Pentacrinites remains are abundant in very high-energy oolite shoal lithofacies. The presence of millericrinids within one, partly allochthonous lithofacies suggests the presence of an otherwise unknown hard substrate from which they have been transported. These results are compared to crinoid assemblages from other Mesozoic localities, and it is evident that the same morphological ad-aptations are present within crinoids from similar lithofacies throughout the Jurassic and Early Cretaceous

Rotating Black Branes in the presence of nonlinear electromagnetic field

In this paper, we consider a class of gravity whose action represents itself as a sum of the usual Einstein-Hilbert action with cosmological constant and an $U(1)$ gauge field for which the action is given by a power of the Maxwell invariant. We present a class of the rotating black branes with Ricci flat horizon and show that the presented solutions may be interpreted as black brane solutions with two event horizons, extreme black hole and naked singularity provided the parameters of the solutions are chosen suitably. We investigate the properties of the solutions and find that for the special values of the nonlinear parameter, the solutions are not asymptotically anti-deSitter. At last, we obtain the conserved quantities of the rotating black branes and find that the nonlinear source effects on the electric field, the behavior of spacetime, type of singularity and other quantities.Comment: 7 pages, 5 figures, to appear in EPJ

Can forest management based on natural disturbances maintain ecological resilience?

Given the increasingly global stresses on forests, many ecologists argue that managers must maintain ecological resilience: the capacity of ecosystems to absorb disturbances without undergoing fundamental change. In this review we ask: Can the emerging paradigm of natural-disturbance-based management (NDBM) maintain ecological resilience in managed forests? Applying resilience theory requires careful articulation of the ecosystem state under consideration, the disturbances and stresses that affect the persistence of possible alternative states, and the spatial and temporal scales of management relevance. Implementing NDBM while maintaining resilience means recognizing that (i) biodiversity is important for long-term ecosystem persistence, (ii) natural disturbances play a critical role as a generator of structural and compositional heterogeneity at multiple scales, and (iii) traditional management tends to produce forests more homogeneous than those disturbed naturally and increases the likelihood of unexpected catastrophic change by constraining variation of key environmental processes. NDBM may maintain resilience if silvicultural strategies retain the structures and processes that perpetuate desired states while reducing those that enhance resilience of undesirable states. Such strategies require an understanding of harvesting impacts on slow ecosystem processes, such as seed-bank or nutrient dynamics, which in the long term can lead to ecological surprises by altering the forest's capacity to reorganize after disturbance

Moderate drinking before the unit: medicine and life assurance in Britain and the US c.1860–1930

This article describes the way in which “Anstie’s Limit” – a particular definition of moderate drinking first defined in Britain in the 1860s by the physician Francis Edmund Anstie (1833–1874) – became established as a useful measure of moderate alcohol consumption. Becoming fairly well-established in mainstream Anglophone medicine by 1900, it was also communicated to the public in Britain, North America and New Zealand through newspaper reports. However, the limit also travelled to less familiar places, including life assurance offices, where a number of different strategies for separating moderate from excessive drinkers emerged from the dialogue between medicine and life assurance. Whilst these ideas of moderation seem to have disappeared into the background for much of the twentieth century, re-emerging as the “J-shaped” curve, these early developments anticipate many of the questions surrounding uses of the “unit” to quantify moderate alcohol consumption in Britain today. The article will therefore conclude by exploring some of the lessons of this story for contemporary discussions of moderation, suggesting that we should pay more attention to whether these metrics work, where they work and why