Integrated data acquisition and processing to determine metabolite contents, relaxation times, and macromolecule baseline in single examinations of individual subjects

Absolute quantitation of clinical (1)H-MR spectra is virtually always incomplete for single subjects because the separate determination of spectrum, baseline, and transverse and longitudinal relaxation times in single subjects is prohibitively long. Integrated Processing and Acquisition of Data (IPAD) based on a combined 2-dimensional experimental and fitting strategy is suggested to substantially improve the information content from a given measurement time. A series of localized saturation-recovery spectra was recorded and combined with 2-dimensional prior-knowledge fitting to simultaneously determine metabolite T(1) (from analysis of the saturation-recovery time course), metabolite T(2) (from lineshape analysis based on metabolite and water peak shapes), macromolecular baseline (based on T(1) differences and analysis of the saturation-recovery time course), and metabolite concentrations (using prior knowledge fitting and conventional procedures of absolute standardization). The procedure was tested on metabolite solutions and applied in 25 subjects (15-78 years old). Metabolite content was comparable to previously found values. Interindividual variation was larger than intraindividual variation in repeated spectra for metabolite content as well as for some relaxation times. Relaxation times were different for various metabolite groups. Parts of the interindividual variation could be explained by significant age dependence of relaxation times.

Intergenomic epistasis causes asynchronous hatch times in whitefish hybrids, but only when parental ecotypes differ

Support for the theory of ecological speciation requires evidence for ecological divergence between species which directly or indirectly causes reproductive isolation. This study investigates effects of ecological vs. genetic disparity of parental species on the presence of endogenous selection (deformation and mortality rates) and potential sources of exogenous selection (growth rates and hatch timing) on hybrids. Hybrid embryonic development is analysed in a common-garden full-sib cross of three species belonging to two different ecotypes within the Coregonus lavaretus species flock in the central Alpine region of Europe. Although hatch timing was similar across the three species, embryonic growth rates and egg sizes differed between ecotypes. This led to a mismatch between embryonic growth rate and egg size in hybrid crosses that reveals epistasis between the maternal and embryonic genomes and transgressive hatch times that were asynchronous with control crosses. A strong constraint of egg size to embryo size at late development was also evident. We argue that this demonstrates potential for coadaptation of a maternal trait (egg size) with offspring growth rate to be an important source of selection against hybridization between ecotypes with different egg sizes. Implications for the measurement and quantification of early life-history traits affected by this additive relationship, such as hatch day and larval size, are also discussed.

Leadership: A Crucial Ingredient in Unstable Times

Social work is experiencing an unprecedented degree of institutional instability, particularly in the advanced industrial nations which, to varying degrees and via differing paths, have abandoned the Keynesian Welfare State. It has been replaced with a fundamentally different workfare regime in which operates on quite different assumptions – all of which pose fundamental challenges to social work. The degree of change is such that it can be understood as institutional change. The profession needs a number of strategies in response the contemporary de-stabilization. Drawing on theoretical and empirical literature about institutional change we show why it is that professional leadership is crucial in the current environment. The paper reviews what in currently know about leadership, both in general and in relation to social work. Referring to the notion of institutional entrepreneurs and on the role played by other non-social work professional associations in situations of change, we articulate what role leadership can play. We conclude with recommendations about how leadership could be promoted, particularly by the professional associations.

Edna Chamberlain (1921 -2005): A Leader through Times of Transition and Change

Professor Edna Chamberlain was an outstanding leader in Australian social work. She contributed extensively to social work education at the University of Queensland, the social work profession through her leadership of the Australian Association of Social Workers and to the community through advocacy for progressive social policies. Her life experiences were influential is shaping her career and her particular teaching and research interests. Early in her life, Chamberlain was exposed to individual deprivation as a result of the Great Depression. This provided the incentive for a career in social work. She worked as a social work practitioner for some years and entered the academic world until after the death of her husband. In the university and profession, she was confronted by conflict between traditionalists and those wanting immediate reform. In managing these tensions, she tried to find the common ground but these tensions also moderated and changed her views about the purpose and practice of social work. Her rich practice and later research and teaching background provided a strong basis for her professional leadership, research activities and curriculum initiatives. Whilst social casework methods were influential early in her career she sought in later years to integrate the private pain of individuals with social policy and community planning by focusing on the purpose of social work – demonstrating her commitment to the disadvantaged in the context of social justice.

Analytical form of the Probability Density Function of travel times in rectangular zone with Tchebyshev’s metric

Geometrical dependencies are being researched for analytical representation of the probability density function (pdf) for the travel time between a random, and a known or another random point in Tchebyshev’s metric. In the most popular case - a rectangular area of service - the pdf of this random variable depends directly on the position of the server. Two approaches have been introduced for the exact analytical calculation of the pdf: Ad-hoc approach – useful for a ‘manual’ solving of a specific case; by superposition – an algorithmic approach for the general case. The main concept of each approach is explained, and a short comparison is done to prove the faithfulness.