Obtaining Statistics of Turbulent Velocity from Astrophysical Spectral Line Data

Turbulence is a crucial component of dynamics of astrophysical fluids dynamics, including those of ISM, clusters of galaxies and circumstellar regions. Doppler shifted spectral lines provide a unique source of information on turbulent velocities. We discuss Velocity-Channel Analysis (VCA) and its offspring Velocity Coordinate Spectrum (VCS) that are based on the analytical description of the spectral line statistics. Those techniques are well suited for studies of supersonic turbulence. We stress that a great advantage of VCS is that it does not necessary require good spatial resolution. Addressing the studies of mildly supersonic and subsonic turbulence we discuss the criterion that allows to determine whether a traditional tool for such a research, namely, Velocity Centroids are dominated by density or velocity. We briefly discuss the use of higher order correlations as the means to study intermittency of turbulence. We discuss observational data available and prospects of the field.Comment: 12 pages, Invited Talk, Penetrating Bars Through Masks of Cosmic Dust, Pilanesberg National Park, South Afrika, 7 June-12 June 200

Leadership = Communication? The relations of leaders' communication styles with leadership styles, knowledge sharing and leadership outcomes

Purpose: The purpose of this study was to investigate the relations between leaders' communication styles and charismatic leadership, human-oriented leadership (leader's consideration), task-oriented leadership (leader's initiating structure), and leadership outcomes. Methodology: A survey was conducted among 279 employees of a governmental organization. The following six main communication styles were operationalized: verbal aggressiveness, expressiveness, preciseness, assuredness, supportiveness, and argumentativeness. Regression analyses were employed to test three main hypotheses. Findings: In line with expectations, the study showed that charismatic and human-oriented leadership are mainly communicative, while task-oriented leadership is significantly less communicative. The communication styles were strongly and differentially related to knowledge sharing behaviors, perceived leader performance, satisfaction with the leader, and subordinate's team commitment. Multiple regression analyses showed that the leadership styles mediated the relations between the communication styles and leadership outcomes. However, leader's preciseness explained variance in perceived leader performance and satisfaction with the leader above and beyond the leadership style variables. Implications: This study offers potentially invaluable input for leadership training programs by showing the importance of leader's supportiveness, assuredness, and preciseness when communicating with subordinates. Originality/value: Although one of the core elements of leadership is interpersonal communication, this study is one of the first to use a comprehensive communication styles instrument in the study of leadership. © 2009 The Author(s)

Appraisals, emotions and emotion regulation: An integrative approach

The present work aims to investigate the relation between appraisals, emotions, and emotion regulation strategies by creating a structural equation model which integrates these three aspects of the emotion process. To reach this aim, Italian students (N = 610) confronted with their high school diploma examination completed a questionnaire 3 weeks before the beginning of the exam. Results showed that they experienced primarily three types of emotions—anxiety/fear, frustration/powerlessness, positive emotions—which were related to specific appraisal profiles. Importantly, these appraisal profiles and emotions were associated with the use of different strategies for regulating emotions: anxiety/fear was associated with focusing on the exam, drug use, and an inability to distance oneself from the exam; frustration/powerlessness, with use of suppression, distancing, and drugs; positive emotion, with reappraisal and problem focused strategies. The effectiveness of these different strategies will be discussed

The developmental impact of prenatal stress, prenatal dexamethasone and postnatal social stress on physiology, behaviour and neuroanatomy of primate offspring: studies in rhesus macaque and common marmoset

RATIONALE: Exposure of the immature mammalian brain to stress factors, including stress levels of glucocorticoids, either prenatally or postnatally, is regarded as a major regulatory factor in short- and long-term brain function and, in human, as a major aetiological factor in neuropsychiatric disorders. Experimental human studies are not feasible and animal studies are required to demonstrate causality and elucidate mechanisms. A number of studies have been conducted and reviewed in rodents but there are relatively few studies in primates. OBJECTIVES: Here we present an overview of our published studies and some original data on the effects of: (1) prenatal stress on hypothalamic-pituitary-adrenal (HPA) re/activity and hippocampus neuroanatomy in juvenile-adolescent rhesus macaques; (2) prenatal dexamethasone (DEX) on HPA activity, behaviour and prefrontal cortex neuroanatomy in infant-adolescent common marmosets; (3) postnatal daily parental separation stress on HPA re/activity, behaviour, sleep and hippocampus and prefrontal cortex neuroanatomy in infant-adolescent common marmoset. RESULTS: Prenatal stress increased basal cortisol levels and reduced neurogenesis in macaque. Prenatal DEX was without effect on HPA activity and reduced social play and skilled motor behaviour in marmoset. Postnatal social stress increased basal cortisol levels, reduced social play, increased awakening and reduced hippocampal glucocorticoid and mineralocorticoid receptor expression in marmoset. CONCLUSIONS: Perinatal stress-related environmental events exert short- and long-term effects on HPA function, behaviour and brain status in rhesus macaque and common marmoset. The mechanisms mediating the enduring effects remain to be elucidated, with candidates including increased basal HPA function and epigenetic programming

Periodontitis and diabetes: a two-way relationship

Periodontitis is a common chronic inflammatory disease characterised by destruction of the supporting structures of the teeth (the periodontal ligament and alveolar bone). It is highly prevalent (severe periodontitis affects 10–15% of adults) and has multiple negative impacts on quality of life. Epidemiological data confirm that diabetes is a major risk factor for periodontitis; susceptibility to periodontitis is increased by approximately threefold in people with diabetes. There is a clear relationship between degree of hyperglycaemia and severity of periodontitis. The mechanisms that underpin the links between these two conditions are not completely understood, but involve aspects of immune functioning, neutrophil activity, and cytokine biology. There is emerging evidence to support the existence of a two-way relationship between diabetes and periodontitis, with diabetes increasing the risk for periodontitis, and periodontal inflammation negatively affecting glycaemic control. Incidences of macroalbuminuria and end-stage renal disease are increased twofold and threefold, respectively, in diabetic individuals who also have severe periodontitis compared to diabetic individuals without severe periodontitis. Furthermore, the risk of cardiorenal mortality (ischaemic heart disease and diabetic nephropathy combined) is three times higher in diabetic people with severe periodontitis than in diabetic people without severe periodontitis. Treatment of periodontitis is associated with HbA1c reductions of approximately 0.4%. Oral and periodontal health should be promoted as integral components of diabetes management

The Cercal Organ May Provide Singing Tettigoniids a Backup Sensory System for the Detection of Eavesdropping Bats

Conspicuous signals, such as the calling songs of tettigoniids, are intended to attract mates but may also unintentionally attract predators. Among them bats that listen to prey-generated sounds constitute a predation pressure for many acoustically communicating insects as well as frogs. As an adaptation to protect against bat predation many insect species evolved auditory sensitivity to bat-emitted echolocation signals. Recently, the European mouse-eared bat species Myotis myotis and M. blythii oxygnathus were found to eavesdrop on calling songs of the tettigoniid Tettigonia cantans. These gleaning bats emit rather faint echolocation signals when approaching prey and singing insects may have difficulty detecting acoustic predator-related signals. The aim of this study was to determine (1) if loud self-generated sound produced by European tettigoniids impairs the detection of pulsed ultrasound and (2) if wind-sensors on the cercal organ function as a sensory backup system for bat detection in tettigoniids. We addressed these questions by combining a behavioral approach to study the response of two European tettigoniid species to pulsed ultrasound, together with an electrophysiological approach to record the activity of wind-sensitive interneurons during real attacks of the European mouse-eared bat species Myotis myotis. Results showed that singing T. cantans males did not respond to sequences of ultrasound pulses, whereas singing T. viridissima did respond with predominantly brief song pauses when ultrasound pulses fell into silent intervals or were coincident with the production of soft hemi-syllables. This result, however, strongly depended on ambient temperature with a lower probability for song interruption observable at 21°C compared to 28°C. Using extracellular recordings, dorsal giant interneurons of tettigoniids were shown to fire regular bursts in response to attacking bats. Between the first response of wind-sensitive interneurons and contact, a mean time lag of 860 ms was found. This time interval corresponds to a bat-to-prey distance of ca. 72 cm. This result demonstrates the efficiency of the cercal system of tettigoniids in detecting attacking bats and suggests this sensory system to be particularly valuable for singing insects that are targeted by eavesdropping bats

The Stimulatory Gαs Protein Is Involved in Olfactory Signal Transduction in Drosophila

Seven-transmembrane receptors typically mediate olfactory signal transduction by coupling to G-proteins. Although insect odorant receptors have seven transmembrane domains like G-protein coupled receptors, they have an inverted membrane topology, constituting a key difference between the olfactory systems of insects and other animals. While heteromeric insect ORs form ligand-activated non-selective cation channels in recombinant expression systems, the evidence for an involvement of cyclic nucleotides and G-proteins in odor reception is inconsistent. We addressed this question in vivo by analyzing the role of G-proteins in olfactory signaling using electrophysiological recordings. We found that Gαs plays a crucial role for odorant induced signal transduction in OR83b expressing olfactory sensory neurons, but not in neurons expressing CO2 responsive proteins GR21a/GR63a. Moreover, signaling of Drosophila ORs involved Gαs also in a heterologous expression system. In agreement with these observations was the finding that elevated levels of cAMP result in increased firing rates, demonstrating the existence of a cAMP dependent excitatory signaling pathway in the sensory neurons. Together, we provide evidence that Gαs plays a role in the OR mediated signaling cascade in Drosophila

Population ecology of the sea lamprey (Petromyzon marinus) as an invasive species in the Laurentian Great Lakes and an imperiled species in Europe

The sea lamprey Petromyzon marinus (Linnaeus) is both an invasive non-native species in the Laurentian Great Lakes of North America and an imperiled species in much of its native range in North America and Europe. To compare and contrast how understanding of population ecology is useful for control programs in the Great Lakes and restoration programs in Europe, we review current understanding of the population ecology of the sea lamprey in its native and introduced range. Some attributes of sea lamprey population ecology are particularly useful for both control programs in the Great Lakes and restoration programs in the native range. First, traps within fish ladders are beneficial for removing sea lampreys in Great Lakes streams and passing sea lampreys in the native range. Second, attractants and repellants are suitable for luring sea lampreys into traps for control in the Great Lakes and guiding sea lamprey passage for conservation in the native range. Third, assessment methods used for targeting sea lamprey control in the Great Lakes are useful for targeting habitat protection in the native range. Last, assessment methods used to quantify numbers of all life stages of sea lampreys would be appropriate for measuring success of control in the Great Lakes and success of conservation in the native range

An Overview of the Ethics of Eating and Drinking

Eating and drinking are ethical acts. When we make decisions about what to eat and what not to, we are making decisions that impact our own health, the well-being of those who work in the food system, animal welfare, and the environment. Food ethics is the interdisciplinary study of how what we eat – including the way it is produced, distributed, marketed, prepared, and ultimately consumed – impacts human, animal, and planetary health and well-being. Food ethics also analyses the justice or fairness of these impacts. Food ethics raises many difficult questions that do not always have clear or easy answers, such as how do we produce enough food to feed everyone well and equitably; how do we ensure that everyone has access to high-quality, nutritious food that is culturally appropriate; how do we do this in a way that treats workers fairly and respectfully, is considerate of animal welfare, and is environmentally sustainable; and how do we shift power across the food system in favor of the public good over multinational food companies. This chapter will explore these questions and more, hopefully encouraging thoughtful discussions and potential solutions for the future