Vegetation Changes in Southeast Australian Temperate Grasslands

In temperate areas of southeast Australia, the combined effects of tree clearing, grazing, application of fertilizer and the introduction of exotic species have modified the original grasslands. This paper describes these changes and attempts to explain them in terms of ecological principles derived from North American grasslands. Stability of the original grasslands appears to have been due to the lack of disturbance and the slow rates of nitrogen (N) cycling within them. Increased N cycling after disturbance has allowed invasion of species better adapted to higher N status, particularly exotic annual grasses and weeds. The present composition of grasslands, in terms of native perennial grasses and exotic species appears to be explainable by the ecological principles outlined

La comunidad de ácaros Mesostigmata (Acari, Mesostigmata) en el dosel arbóreo de bosques de pícea en Irlanda en comparación con la presente en hábitats muscícolas edáficos

The main aim of this study was to examine the communities of mesostigmatid mites occurring in Irish Sitka spruce (Picea sitchensis) canopies or inhabiting moss, either in the canopy or on the soil surface, and to discover whether a characteristic assemblage of species occurs in particular habitat patches (ground vs. aerial). Twenty two species of Mesostigmata were recorded, of which five occurred exclusively in arboreal microhabitats. All three species of Zerconidae collected were unique to the canopy and moss mats on the tree branches. Trachytes aegrota (C.L. Koch, 1841) was recorded for the first time in Ireland and some comments about its distribution are made. Multivariate analysis indicated that the arboreal mesostigmatid community is not just a subset of the assemblage occurring in moss on soil or trunks and that it appears to be more homogeneous than those occurring on the soil surface.El objetivo principal de este trabajo fue estudiar en Irlanda las comunidades de ácaros Mesostigmata del dosel arbóreo de bosques de Picea sitchensis y en el musgo desarrollado tanto en zonas aéreas como en la superficie edáfica, con el fin de determinar si la estructura y composición de éstas comunidades variaba entre los hábitats diferenciales (edáficos vs. aéreos). Se obtuvieron 22 especies de ácaros Mesostigmata, de las cuales 5 aparecieron solamente en micro-hábitats arbóreos. Las especies de la familia Zerconidae recogidas en este estudio se encontraron exclusivamente en ramas y musgos desarrollados en el dosel. Trachytes aegrota (C.L. Koch, 1841), es citado por primera vez para Irlanda. Se ofrecen asimismo comentarios sobre la distribución de esta especie. El análisis multivariante de los resultados indicó que las poblaciones arbóreas de ácaros Mesostigmata no son un mero subconjunto estructural sino que forman una comunidad diferencial respecto a las presentes en hábitats muscícolas del tronco o del medio edáfico, y son más homogéneas que las existentes en la superficie del suelo

Controlling the uncontrolled: Are there incidental experimenter effects on physiologic responding?

The degree to which experimenters shape participant behavior has long been of interest in experimental social science research. Here, we extend this question to the domain of peripheral psychophysiology, where experimenters often have direct, physical contact with participants, yet researchers do not consistently test for their influence. We describe analytic tools for examining experimenter effects in peripheral physiology. Using these tools, we investigate nine data sets totaling 1,341 participants and 160 experimenters across different roles (e.g., lead research assistants, evaluators, confederates) to demonstrate how researchers can test for experimenter effects in participant autonomic nervous system activity during baseline recordings and reactivity to study tasks. Our results showed (a) little to no significant variance in participants' physiological reactivity due to their experimenters, and (b) little to no evidence that three characteristics of experimenters that are well known to shape interpersonal interactions-status (using five studies with 682 total participants), gender (using two studies with 359 total participants), and race (in two studies with 554 total participants)-influenced participants' physiology. We highlight several reasons that experimenter effects in physiological data are still cause for concern, including the fact that experimenters in these studies were already restricted on a number of characteristics (e.g., age, education). We present recommendations for examining and reducing experimenter effects in physiological data and discuss implications for replication

The Role and Sources of Individual Differences in Critical-Analytic Thinking: a Capsule Overview

Critical-analytic thinking is typically conceived as a meta-construct that arises at the junction of a problem state (i.e., a situation that requires analysis that challenges previous assumptions) and an individual (i.e., an entity with the capacity to exercise critical-analytic thinking). With regard to the latter, there is a substantial body of research focusing on developmental and educational prerequisites for critical-analytic thinking. A less studied aspect of critical-analytic thinking pertains to individual differences, particularly in the set of foundational or componential cognitive skills that embody this construct. The bottom line here is whether, all else being equal (i.e., the same situation and the same developmental/educational stage), there is variation in whether, when, and how people think critically/analytically. We argue that there is unequivocal evidence for both the existence and importance of individual differences in critical-analytic thinking. This review focuses on theoretical and empirical evidence, identifying the cognitive processes that serve as the sources of these individual differences and capturing these processes’ differential contributions to both the critical and analytic components of this construct.National Institutes of Health (U.S.) (Grant HD079143

Responses of aquatic invertebrates to anthropogenic sound across different life history stages

Underwater soundscapes have grown considerably louder over the previous century due to increases in anthropogenic noise, with increasing evidence that manmade sound can negatively impact aquatic fauna. Despite their vital ecological roles, and increasing commercial importance, the effects of sound on aquatic invertebrates are understudied in comparison to marine mammals and fish, despite their ability to perceive sound. Even fewer studies have considered the responses of early life aquatic invertebrates to underwater sound, despite their often greater vulnerability to environmental stressors compared to adults. Through a series of controlled laboratory experiments, five model species (Norway lobster Nephrops norvegicus (L.), European lobster Homarus gammarus (L.), the European flat oyster Ostrea edulis (L.), the veined squid Loligo forbesii (Steenstrup, 1857) and the water flea Daphnia magna (Straus, 1820)) were exposed to playbacks of anthropogenic noise. Two key knowledge gaps were addressed in this thesis: whether, and how 1) continuous noise (the most common anthropogenic noise source in the field) affects the early life stages of aquatic invertebrates and 2) noise impacts on aquatic invertebrates carry over from one life stage to the next e.g. from larva to juvenile or from mother to offspring. The early life stages of four out of the five model species studied were negatively impacted by noise, demonstrating that noise susceptibility is shared across a functionally and taxonomically diverse range of early life aquatic invertebrates. The experiments also revealed that impacts can carry over from larva to juvenile (N. norvegicus) and from mother to offspring (D. magna). The scientific evidence generated here will inform future research, legislative decision makers and managers of the importance of considering early life invertebrates as receptors of anthropogenic noise impacts, allowing them to generate more adequate mitigation strategies to uphold their commitments to limiting the impacts of noise on the marine environment

Developing and validating an experience sampling measure of aggression:The Aggression-ES Scale

Experience sampling methodologies are likely to play an important role in advancing our understanding of momentary influences on aggression, including short-term antecedent psychological states and situations. In this study, we evaluate whether a newly developed experiencing sampling measure of aggression, the Aggression Experience Sampler (Aggression-ES), provides a valid and reliable measure of aggression in experience sampling contexts. Participants were a convenience sample of 23 young adults recruited from the local University community. Data were collected using an experience sampling smartphone application over 8 days. They were analyzed using multilevel structural equation modeling. Our results support the within- and between-person reliability and the criterion validity of the Aggression-ES. The Aggression-ES represents a good choice of measure for use in experience sampling studies of aggression. Further work in other samples will help to provide further validity evidence for the measure

Chronic myocardial infarction promotes atrial action potential alternans, afterdepolarisations and fibrillation

Aims: Atrial fibrillation (AF) is increased in patients with heart failure resulting from myocardial infarction (MI). We aimed to determine the effects of chronic ventricular MI in rabbits on the susceptibility to AF, and underlying atrial electrophysiological and Ca2+-handling mechanisms. Methods and results: In Langendorff-perfused rabbit hearts, under beta-adrenergic-stimulation with isoproterenol (1 µM; ISO), 8 weeks MI decreased AF threshold, indicating increased AF-susceptibility. This was associated with increased atrial action potential duration-alternans at 90% repolarisation, by 147%, and no significant change in mean APD or atrial global conduction velocity (n=6-13 non-MI hearts, 5-12 MI). In atrial isolated myocytes, also under beta-stimulation, L-type Ca2+ current (ICaL) density and intracellular Ca2+-transient amplitude were decreased by MI, by 35% and 41%, respectively, and the frequency of spontaneous depolarisations (SDs) was substantially increased. MI increased atrial myocyte size and capacity, and markedly decreased transverse-tubule density. In non-MI hearts perfused with ISO, the ICaL-blocker nifedipine, at a concentration (0.02 µM) causing an equivalent ICaL-reduction (35%) to that from the MI, did not affect AF-susceptibility, and decreased APD. Conclusion: chronic MI in rabbits remodels atrial structure, electrophysiology and intracellular Ca2+-handling. Increased susceptibility to AF by MI, under beta-adrenergic-stimulation, may result from associated production of atrial APD-alternans and SDs, since steady-state APD and global conduction velocity were unchanged under these conditions, and may be unrelated to the associated reduction in whole-cell ICaL. Future studies may clarify potential contributions of local conduction changes, and cellular and sub-cellular mechanisms of alternans, to the increased AF-susceptibility