Nearshore-offshore-basin species diversity and body size variation patterns in Late Permian (Changhsingian) brachiopods

 B.V. Body size is a fundamental and defining character of an organism, and its variation in space and time is generally considered to be a function of its biology and interactions with its living environment. A great deal of body size related ecological and evolutionary research has been undertaken, mostly in relation to extant animals. Among the many body size-related hypotheses proposed and tested, the size-bathymetry relationship is probably the least studied. In this study, we compiled a global body size dataset of Changhsingian (Late Permian, ca. 254. Ma-252. Ma) brachiopod species from low-latitude areas (30°S-30°N) and analyzed their species diversity and body size distribution patterns in relation to the nearshore-offshore-basin bathymetric gradient. The dataset contained 1768 brachiopod specimens in 435 species referred to 159 genera and 9 orders, from 135 occurrences (localities) of 18 different palaeogeographic regions. Treating the whole of the Changhsingian Stage as a single time slice, we divided the nearshore-offshore-basin bathymetric gradient into three broad depth-related environments: nearshore, offshore and basinal environments, and compared how the species diversity and body size varied along this large-scale bathymetric gradient.Here, we report an array of complex patterns. First, we found a clear overall inverse correlation between species diversity and water depth along the nearshore-offshore-basin gradient, with most species concentrating in the nearshore environment. Second, when the median sizes of all low-latitude brachiopod species from the three environments were compared, we found that there was no significant size difference between the nearshore and offshore environments, suggesting that neither the wave base nor the hydrostatic pressure exerts a critical influence on the body size of brachiopods. On the other hand, the median sizes of brachiopods from the nearshore environment and, to a lesser extent, the offshore environment were found to be significantly larger than that of basinal brachiopods. This trend of significant size reduction in basinal brachiopods mirrors the relative low species diversity in the basinal environment, and neither can be easily explained by the tendency of decreasing food availability towards deeper sea environments. Rather, both trends are consistent with the hypothesis of an expanding Oxygen Minimum Zone (OMZ) in the bathyal (slope to deepsea) environments, where hypoxic to anoxic conditions are considered to have severely restricted the diversification of benthos and favored the relative proliferation of small-sized brachiopods. Finally, a significant difference was also found between eurybathic and stenobathic species in their body size response to the nearshore-offshore-basin gradient, in that eurybathic species (species found in all three environments) did not tend to change their body size significantly according to depth, whereas stenobathic forms (species restricted to a single environment) exhibit a decline in body size towards the basinal environment. This pattern is interpreted to suggest that bathymetrically more tolerant species are less sensitive to depth control with respect to their body size change dynamics, in contrast to stenobathic species which tend to grow larger in shallower water depths.

Significant pre-mass extinction animal body-size changes : evidences from the Permian–Triassic boundary brachiopod faunas of South China

This paper has undertaken a quantitative and statistical analysis of brachiopod body-size changes through the marine Permian–Triassic boundary section at Zhongzhai, Guizhou Province, South China, and found that (1) pre-mass extinction dwarfing is evident for at least the rugosochonetid species chosen for this study; (2) Tethyochonetes species reduced their size earlier than that in the Neochonetes species; and (3) no significant size reduction occurred in the newly evolved species of these two genera. Inter-species competition for resources between Neochonetes species and Tethyochonetes species and the reduction of food supply in the upper part of the uppermost Permian is here proposed to explain these observed stratigraphic patterns of brachiopod body-size changes throughout the Zhongzhai section. In the case of the newly evolved species showing no significant body-size change, morphological innovations (adaptations) in the process of speciation are considered to have significantly enhanced these newly evolved species' flexibility and survival in coping with degrading environmental conditions.

Structure and characteristics of milled silk particles

This study examined the structure, thermal property, and ion adsorption of silk particles. The particles were prepared by attritor-bead mill combination, using alkaline (pH10) charge repulsion and surfactant steric repulsion methods. Both methods produced particles with a dominant β-sheet structure, similar to the silk fibre. There was no significant difference in the decomposition temperatures for either the silk fibre or the micro/nano silk particles. An important finding from this study is clear evidence of reduction of amorphous content during the final stage of powdering using the bead mill. As a result, despite reduction in β-sheet crystallites with the progressive milling, the relative β-sheet content actually increased during this process. However, intermolecular forces between the β-sheets reduced significantly and hence the XRD results showed significant reduction in crystallinity in nano silk particles but crystal forming segments remained with β-sheet conformations after milling. The structural change influenced the ion-adsorption property where particle-size reduction resulted in a significant increase in both the rate and volume of HCrO4- adsorption. © 2014 Elsevier B.V.

Clinical trial adaptation by matching evidence in complementary patient sub-groups of auxiliary blinding questionnaire responses

Clinical trial adaptation refers to any adjustment of the trial protocol after the onset of the trial. Such adjustment may take on various forms, including the change in the dose of administered medicines, the frequency of administering an intervention, the number of trial participants, or the duration of the trial, to name just some possibilities. The main goal is to make the process of introducing new medical interventions to patients more efficient, either by reducing the cost or the time associated with evaluating their safety and efficacy. The principal challenge, which is an outstanding research problem, is to be found in the question of how adaptation should be performed so as to minimize the chance of distorting the outcome of the trial. In this paper we propose a novel method for achieving this. Unlike most of the previously published work, our approach focuses on trial adaptation by sample size adjustment i.e. by reducing the number of trial participants in a statistically informed manner. We adopt a stratification framework recently proposed for the analysis of trial outcomes in the presence of imperfect blinding and based on the administration of a generic auxiliary questionnaire that allows the participants to express their belief concerning the assigned intervention (treatment or control). We show that this data, together with the primary measured variables, can be used to make the probabilistically optimal choice of the particular sub-group a participant should be removed from if trial size reduction is desired. Extensive experiments on a series of simulated trials are used to illustrate the effectiveness of our method.

Association of birth weight and current body size to blood pressure in female twins

It has been proposed that low birth weight is associated with high levels of blood pressure in later life. The aim of this study was to assess the relationship of blood pressure to birth weight and current body size during growth and adulthood. A total of 711 female multiple births, with one group of 244 in their growth phase mean age 12.0 (2.3)(SD) years and the other of 467 adults (mean age 35.2 (12.6) years), had height, weight and both systolic (SBP) and diastolic (DBP) blood pressures measured, and self-reported their birth weight. Regression analyses were performed to assess the cross-sectional and within-pair associations of blood pressure to birth weight, with and without adjustments for current body size. Within-pair analysis was based on 296 twin pairs. Cross-sectionally, a reduction in birth weight of 1 kg was associated with 2 to 3 mm Hg higher age-adjusted SBP, which was of marginal significance and explained about 2% of the population variance. Adjustment for body mass index did not significantly change this association. Within-pair analyses found no association between birth weight and SBP or DBP,even after adjusting for current body size. After age, current body size was the strongest predictor of systolic BP. The weak association of blood pressure to birth weight cross-sectionally is of interest, but any within-pair effect of birth weight on blood pressure must be minimal compared with the effect of current body size.

Analytical model of pass-by-pass strain in rod (or bar) rolling and its applications to prediction of austenite grain size

Rod rolling is a process where the deformation state of the workpiece between the work rolls is quite different from the strip rolling process. However, in most microstructure evolution models, the simple area strains (natural logarithm of the area reduction ratio) multiplied by a constant have been used to compute pass-by-pass evolution of austenite grain size (AGS) in rod (or bar) rolling, without any verification. The strains at a given pass play a crucial role in determining the recrystallization behavior (static or dynamic). In this study, an analytical model that calculates the pass-by-pass strain and strain rate in rod rolling has been developed and verified by conducting four-pass (oval–round) bar and plate rolling experiments. Numerical simulations have then been carried out for the four-pass rolling sequence using the area strain model and the new analytical model, focusing on the effect of the method for calculating the strain on the recrystallization behavior and evolution of AGS. The AGS predicted was compared with those obtained from hot torsion tests. It is shown that the analytical model developed in this study is more appropriate in the analysis of bar (or rod) rolling. It was found that the recrystallization behavior and evolution of AGS during this process were influenced significantly by the calculation method for the deformation parameters (strain and strain rate). The pass-by-pass strain obtained from the simple area strain model is inadequate to be used as an input to the equations for recrystallization and AGS evolution under these rolling conditions.

On the size of training set and the benefit from ensemble

In this paper, the impact of the size of the training set on the benefit from ensemble, i.e. the gains obtained by employing ensemble learning paradigms, is empirically studied. Experiments on Bagged/ Boosted J4.8 decision trees with/without pruning show that enlarging the training set tends to improve the benefit from Boosting but does not significantly impact the benefit from Bagging. This phenomenon is then explained from the view of bias-variance reduction. Moreover, it is shown that even for Boosting, the benefit does not always increase consistently along with the increase of the training set size since single learners sometimes may learn relatively more from additional training data that are randomly provided than ensembles do. Furthermore, it is observed that the benefit from ensemble of unpruned decision trees is usually bigger than that from ensemble of pruned decision trees. This phenomenon is then explained from the view of error-ambiguity balance.

The contribution of residential solar energy systems to the reduction of greenhouse gas emissions in the borough of Queenscliffe

The Borough of Queenscliffe has identified the importance of reducing its greenhouse gas emissions and aims to become a carbon zero municipality by 2020. For a house, suburb or town to become carbon neutral ideally it produces an equivalent amount of energy from renewable resources to that which it consumes. By increasing the number of solar systems, both photovoltaic (PV) and hot water, in the residential sector, greenhouse gas emissions will be reduced. The number of solar systems located in the Borough of Queenscliffe has been estimated and a database of these systems has been created, including the size and panel orientation. The energy generated by each solar system, in addition to the reductions in greenhouse gas emissions, has been calculated for an average year.

Voltage stability analysis with optimum size and location based synchronous machine DG

Power loss of a distribution system can be reduced significantly by using optimum size and location of distributed generation (DG). Proper allocation of DG with appropriate size maximizes overall system efficiency. Moreover it improves the reliability and voltage profile of the distribution system. In this paper, IEEE 123 node test feeder has been considered to determine the optimum size and location of a synchronous machine based DG for loss reduction of the system. This paper also investigates the steady-state and dynamic voltage profile of that three phase unbalance distribution network in presence of DG with optimum size. This analysis shows that optimum size of DG at proper location minimizes the power loss as well as improves the dynamic voltage profile of the distribution system.

Reducing the size distortions of the panel LM test for cointegration

This paper proposes a simple procedure to reduce the size distortions of the panel LM test for cointegration. The new procedure is based on first splitting the sample into even and odd numbered observations, and to employ the panel LM test to each subsample. The two tests are then combined using the Bonferroni principle as suggested by Choi [Choi, I., 2004, Improving the empirical size of the KPSS Test of stationarity, unpublished manuscript, Department of Economics, Hong Kong University of Science and Technology]. The Monte Carlo evidence suggests that this procedure can lead to substantial reduction in size distortions when the equilibrium errors are autoregressive. © 2005 Elsevier B.V. All rights reserved.

Mechanism of a green graphene oxide reduction with reusable potassium carbonate

 A green method for the deoxygenation of graphene oxide (GO) was developed using K2CO3 as a reusable reduction agent. The size and thickness of the reduced GO are less than 1 μm and around 0.85 nm, respectively. Carbon dioxide is the only byproduct during this process. The reduction mechanism of the graphene oxide includes two reduction steps. On the one hand, ionic oxygen generated from the electrochemical reaction between hydroxyl ions and oxygen in the presence of K2CO3 reacts with carbonyl groups attached to the GO layers at 50°C. On the other hand, ionic oxygen attacks hydroxyl and epoxide groups, which become carbonyl groups and then are converted to carbon dioxide by K2CO3 at 90°C. These oxygenous groups are finally converted to CO2 from graphene layers, leading to the formation of graphene sheets. Headspace solid-phase microextraction and gas chromatography-mass spectrometry detected the existence of n-dodecanal and 4-ethylbenzoic acid cyclopentyl ester during the reduction, suggesting that oxygen functional groups on the GO layers are not only aligned, but randomly dispersed in some areas based on the proposed mechanism.

Dependence of deformation behavior on grain size and strain rate in an ultrahigh strength-ductile Mn-based TRIP alloy

A novel ultra-high strength TRIP (transformation induced plasticity) steel, with ~1.5. GPa strength and good ductility of ~26% has been produced. The microstructure consists of ultrafine ferrite, and a large volume fraction of austenite. The flow stress was significantly increased by a reduction in the grain size, but the effect of strain rate on the flow stress was negligible. The formation of stress induced martensite was found to increase linearly with strain, and a reduction in the grain size correlated with an increase in the stress required to form the martensite.

Modulated deformation of lipid membrane to vesicles and tubes due to reduction of graphene oxide substrate under laser irradiation

Biomembrane transformations are closely related to many biological processes including endo/exocytosis and the cellular response to the local physical environment. In this work, we investigated the transformation between lipid membranes and lipid vesicles/tubes modulated by the solid substrate of graphene oxide (GO) aggregates under laser irradiation. We firstly fabricate a novel type of lipid@GO composite consisting of micrometer-sized GO aggregates surrounded by lamellar lipid membranes. Upon laser irradiation, lipid protrusion occurs and leads to the formation of vesicles adsorbed on the GO aggregate surface, with an average size as 0.43 times of the radius of GO aggregate. Both the location and the dynamic formation process of vesicles can be modulated. The arising of vesicles prefers to occur at edges of the GO planes rather than on surface of individual GO sheets within the GO aggregate. Furthermore, at a reduced laser power density, the lipid protrusion mainly grows to tubes instead of vesicles. Such transformations from lipid membrane to vesicles and tubes is ascribed to the reduction of GO to reduced-GO (rGO) under laser irradiation, probably along with the release of gases leading to the deformation of lipid membrane surrounding the GO surface.