Female body condition affects foetal growth in a capital breeding mysticete

1.Sex allocation theory has received considerable attention, yet the mechanism(s) by which mothers skew offspring sex ratios remain unknown. In birds, females are the heterogametic sex, which potentially gives them control of whether gametes will be male or female. How females might control the sex of the gamete is unclear, but one possibility is that variation in steroid hormones may mediate this process. 2.We experimentally altered circulating levels of corticosterone in female Gouldian finches (Erythrura gouldiae), a species that demonstrates both extreme stress responses and extreme offspring sex ratio biases when breeding with a low-quality (genetically incompatible) partner. 3.During egg production, individual females received both corticosterone and metyrapone (a corticosterone-synthesis inhibitor) implants, in random order, to induce both high and low levels of circulating stress hormones (within physiological limits). 4.We found that females with elevated corticosterone levels produced male-biased sex ratios, but when the same females were treated with metyrapone they produced female-biased offspring sex ratios. 5.These stress responses are adaptive because females constrained to breeding with low-quality males can substantially increase their fitness by overproducing sons. Changes in maternal corticosterone levels during stressful situations, such as the quality of a breeding partner, may provide an endocrine mechanism that can be exploited for strategic sex allocation.

Metrics to assess ecological condition, change, and impacts in sandy beach ecosystems

Complexity is increasingly the hallmark in environmental management practices of sandy shorelines. This arises primarily from meeting growing public demands (e.g., real estate, recreation) whilst reconciling economic demands with expectations of coastal users who have modern conservation ethics. Ideally, shoreline management is underpinned by empirical data, but selecting ecologically-meaningful metrics to accurately measure the condition of systems, and the ecological effects of human activities, is a complex task. Here we construct a framework for metric selection, considering six categories of issues that authorities commonly address: erosion; habitat loss; recreation; fishing; pollution (litter and chemical contaminants); and wildlife conservation. Possible metrics were scored in terms of their ability to reflect environmental change, and against criteria that are widely used for judging the performance of ecological indicators (i.e., sensitivity, practicability, costs, and public appeal). From this analysis, four types of broadly applicable metrics that also performed very well against the indicator criteria emerged: 1.) traits of bird populations and assemblages (e.g., abundance, diversity, distributions, habitat use); 2.) breeding/reproductive performance sensu lato (especially relevant for birds and turtles nesting on beaches and in dunes, but equally applicable to invertebrates and plants); 3.) population parameters and distributions of vertebrates associated primarily with dunes and the supralittoral beach zone (traditionally focused on birds and turtles, but expandable to mammals); 4.) compound measurements of the abundance/cover/biomass of biota (plants, invertebrates, vertebrates) at both the population and assemblage level. Local constraints (i.e., the absence of birds in highly degraded urban settings or lack of dunes on bluff-backed beaches) and particular issues may require alternatives. Metrics - if selected and applied correctly - provide empirical evidence of environmental condition and change, but often do not reflect deeper environmental values per se. Yet, values remain poorly articulated for many beach systems; this calls for a comprehensive identification of environmental values and the development of targeted programs to conserve these values on sandy shorelines globally.

Seasonal stress physiology and body condition differ among co-occurring tropical finch species.

Seasonal changes in avian hormonal stress responses and condition are well known for common species found at temperate and arctic latitudes, but declining and tropical species are poorly studied. This study compares stress and condition measures of co-occurring declining and non-declining tropical grass finch species in Australia. We monitored declining Gouldian finches (Erythrura gouldiae) and non-declining long-tailed and masked finches (Poepila acuticauda and P. personata) during two seasons that are potentially stressful: peak breeding (early dry season when food is plentiful) and moult (late dry to early wet season when food may be scarce). We measured body condition (muscle and fat), haematocrit, and stress response to capture using plasma corticosterone and binding globulin concentrations. All species had higher muscle and lower fat indices during breeding than moult. Haematocrit did not consistently differ between seasons. Long-tailed finches had higher stress responses during breeding than moult, similar to other passerines studied. Masked finches showed no seasonal changes in stress response. Gouldian finches had stress response patterns opposite to those of long-tailed finches, with higher stress responses during moult. However, seasonal trends in Gouldian and long-tailed finch stress responses sometimes differed between years or sites. The differences in stress response patterns between species suggest that the declining Gouldian finch is more sensitive to recent environmental changes which are thought to further reduce grass seed food resources during the late dry to early wet season. Retention of stress responsiveness during a protracted moult could increase the survival potential of Gouldian finches. This study highlights the utility of stress and condition indices to determine the sensitivity of co-occurring species to environmental conditions.

General approach for electrochemical functionalization of glassy carbon surface by in situ generation of diazonium ion under acidic and non-acidic condition with a cascade protocol

Immobilization of catechol derivatives on GC electrode surfaces can be performed by in situ generation and reduction of nitrocatechol. We present the oxidative nitration of catechol in the presence of nitrous acid followed by electrochemically reduction of the generated nitro aromatic group to the corresponding amine group and its conversion to diazonium cation at the electrode surface to yield a surface covalently modified with catechol. In this manner, some derivatives of catechol can be immobilized on the electrode surface. Whole of the process is carried out in Triethylammonium acetate ionic liquid as an inert and neutral medium (pH∼7.0). Surface coverage can be easily controlled by the applied potential, time and concentration of catechol. After modification, the electrochemical features of modified surface have been studied. Also modified GC electrode exhibited remarkable catalytic activity in the oxidation of NADH. The catalytic currents were proportional to the concentration of NADH over the range 0.01-0.80 mM. This condition can be used for modification of GC surfaces by various aromatic molecules for different application such as design of sensors and biosensors. © 2014 Elsevier Ltd. All rights reserved.

Condition monitoring of induction motors : A review and an application of an ensemble of hybrid intelligent models

In this paper, a review on condition monitoring of induction motors is first presented. Then, an ensemble of hybrid intelligent models that is useful for condition monitoring of induction motors is proposed. The review covers two parts, i.e.; (i) a total of nine commonly used condition monitoring methods of induction motors; and (ii) intelligent learning models for condition monitoring of induction motors subject to single and multiple input signals. Based on the review findings, the Motor Current Signature Analysis (MCSA) method is selected for this study owing to its online, non-invasive properties and its requirement of only single input source; therefore leading to a cost-effective condition monitoring method. A hybrid intelligent model that consists of the Fuzzy Min-Max (FMM) neural network and the Random Forest (RF) model comprising an ensemble of Classification and Regression Trees is developed. The majority voting scheme is used to combine the predictions produced by the resulting FMM-RF ensemble (or FMM-RFE) members. A benchmark problem is first deployed to evaluate the usefulness of the FMM-RFE model. Then, the model is applied to condition monitoring of induction motors using a set of real data samples. Specifically, the stator current signals of induction motors are obtained using the MCSA method. The signals are processed to produce a set of harmonic-based features for classification using the FMM-RFE model. The experimental results show good performances in both noise-free and noisy environments. More importantly, a set of explanatory rules in the form of a decision tree can be extracted from the FMM-RFE model to justify its predictions. The outcomes ascertain the effectiveness of the proposed FMM-RFE model in undertaking condition monitoring tasks, especially for induction motors, under different environments. © 2014 Elsevier Ltd. All rights reserved.

Condition monitoring of broken rotor bars using a hybrid FMM-GA model

A condition monitoring system for induction motors using a hybrid Fuzzy Min-Max (FMM) neural network and Genetic Algorithm (GA) is presented in this paper. Two types of experiments, one from the finite element method and another from real laboratory tests of broken rotor bars in an induction motor are conducted. The induction motor with broken rotor bars is operated under different load conditions. FMM is first used for learning and distinguishing between a healthy motor and one with broken rotor bars. The GA is then utilized for extracting fuzzy if-then rules using the don’t care approach in minimizing the number of rules. The results clearly demonstrate the effectiveness of the hybrid FMM-GA model in condition monitoring of broken rotor bars in induction motors.

Direct perception, inter-subjectivity and social cognition: why phenomenology is a necessary but not sufficient condition

In this paper I argue that many of the core phenomenological insights, including the emphasis on direct perception, are a necessary but not sufficient condition for an adequate account of inter-subjectivity today. I take it that an adequate account of inter-subjectivity must involve substantial interaction with empirical studies, notwithstanding the putative methodological differences between phenomenological description and scientific explanation. As such, I will need to explicate what kind of phenomenology survives, and indeed, thrives, in a milieu that necessitates engagement with the relevant sciences, albeit not necessarily deference to them. There will be two central aims to this paper: 1. to defend the centrality and vitality of phenomenological treatments of inter-subjectivity via a consideration of some remarks in Sartre - which I do think possess a non-trivial unity amongst the various interlocutors - and the manner in which they in fact serve to provide the basis for a better explanation of an array of empirical data than existing inferentialist or mindreading accounts of social cognition (notably Theory Theory, Simulation Theory, and hybrid versions); 2. to offer the methodological resources for renewing phenomenology in a manner that acknowledges ostensibly non-phenomenological moments in theory production - which involve explanation, inference to the best explanation, etc. - but does not abandon phenomenology for all that, allowing it to be simply absorbed into empirical explanation or other forms of philosophical analysis without remainder.

Variation in body condition during the post-moult foraging trip of southern elephant seals and its consequences on diving behaviour

Mature female southern elephant seals (Mirounga leonina) come ashore only in October to breed and in January to moult, spending the rest of the year foraging at sea. Mature females may lose as much as 50% of their body mass, mostly in lipid stores, during the breeding season due to fasting and lactation. When departing to sea, post-breeding females are negatively buoyant, and the relative change in body condition (i.e. density) during the foraging trip has previously been assessed by monitoring the descent rate during drift dives. However, relatively few drift dives are performed, resulting in low resolution of the temporal reconstruction of body condition change. In this study, six post-breeding females were equipped with time-depth recorders and accelerometers to investigate whether changes in active swimming effort and speed could be used as an alternative method of monitoring density variations throughout the foraging trip. In addition, we assessed the consequences of density change on the swimming efforts of individuals while diving and investigated the effects on dive duration. Both descent swimming speed and ascent swimming effort were found to be strongly correlated to descent rate during drift dives, enabling the fine-scale monitoring of seal density change over the whole trip. Negatively buoyant seals minimized swimming effort during descents, gliding down at slower speeds, and reduced their ascent swimming effort to maintain a nearly constant swimming speed as their buoyancy increased. One per cent of seal density variation over time was found to induce a 20% variation in swimming effort during dives with direct consequences on dive duration.