Destructive sampling natural science collections: an overview for museum professionals and researchers

There are many reasons why museum collections may be used for destructive sampling, from DNA and isotope analysis to radiocarbon dating. The process is invasive and destroys a part, or all, of the specimen. This can result in reluctance by museum staff to allow specimens to be used in particular types of scientific research. We will present some of the motivations on both sides, but argue that the benefits of destructive sampling can outweigh the risks. Many analytical methods have improved dramatically in the last 30 years, requiring smaller sample sizes. With a focus on destructive sampling for genetic analysis, we will also present some examples from the literature where DNA from museum and archaeological specimens has greatly aided the reconstruction of a species' evolutionary history as well as enriching our understanding of the object sampled. In addition, we highlight the need for museum staff to understand exactly what researchers are asking for, and for researchers in turn to understand museum procedures. We include an example of a Destructive Sampling Policy and a Destructive Sampling Request Form, for institutions to adapt for their own use

Destructive sampling natural science collections: an overview for museum professionals and researchers

There are many reasons why museum collections may be used for destructive sampling, from DNA and isotope analysis to radiocarbon dating. The process is invasive and destroys a part, or all, of the specimen. This can result in reluctance by museum staff to allow specimens to be used in particular types of scientific research. We will present some of the motivations on both sides, but argue that the benefits of destructive sampling can outweigh the risks. Many analytical methods have improved dramatically in the last 30 years, requiring smaller sample sizes. With a focus on destructive sampling for genetic analysis, we will also present some examples from the literature where DNA from museum and archaeological specimens has greatly aided the reconstruction of a species' evolutionary history as well as enriching our understanding of the object sampled. In addition, we highlight the need for museum staff to understand exactly what researchers are asking for, and for researchers in turn to understand museum procedures. We include an example of a Destructive Sampling Policy and a Destructive Sampling Request Form, for institutions to adapt for their own use

Second-order propositional modal logic: expressiveness and completeness results

In this paper we advance the state-of-the-art on the application of second-order propositional modal logic (SOPML) in the representation of individual and group knowledge, as well as temporal and spatial reasoning. The main theoretical contributions of the paper can be summarised as follows. Firstly, we introduce the language of (multi-modal) SOPML and interpret it on a variety of different classes of Kripke frames according to the features of the accessibility relations and of the algebraic structure of the quantification domain of propositions. We provide axiomatisations for some of these classes, and show that SOPML is unaxiomatisable on the remaining classes. Secondly, we introduce novel notions of (bi)simulations and prove that they indeed preserve the interpretation of formulas in (the universal fragment of) SOPML. Then, we apply this formal machinery to study the expressiveness of Second-order Propositional Epistemic Logic (SOPEL) in representing higher-order knowledge, i.e., the knowledge agents have about other agents’ knowledge, as well as graph-theoretic notions (e.g., 3-colorability, Hamiltonian paths, etc.). The final outcome is a rich formalism to represent and reason about relevant concepts in artificial intelligence, while still having a model checking problem that is no more computationally expensive than that of the less expressive quantified boolean logic

Logics of preference when there is no best

Well-behaved preferences (e.g., total pre-orders) are a cornerstone of several areas in artificial intelligence, from knowledge representation, where preferences typically encode likelihood comparisons, to both game and decision theories, where preferences typically encode utility comparisons. Yet weaker (e.g., cyclical) structures of comparison have proven important in a number of areas, from argumentation theory to tournaments and social choice theory. In this paper we provide logical foundations for reasoning about this type of preference structures where no obvious best elements may exist. Concretely, we compare and axiomatize a number of ways in which the concepts of maximality and optimality can be lifted to this general class of preferences. In doing so we expand the scope of the long-standing tradition of the logical analysis of preference

Historic landmarks in clinical transplantation: Conclusions from the consensus conference at the University of California, Los Angeles

The transplantation of organs, cells, and tissues has burgeoned during the last quarter century, with the development of multiple new specialty fields. However, the basic principles that made this possible were established over a three-decade period, beginning during World War II and ending in 1974. At the historical consensus conference held at UCLA in March 1999, 11 early workers in the basic science or clinical practice of transplantation (or both) reached agreement on the most significant contribution of this era that ultimately made transplantation the robust clinical discipline it is today. These discoveries and achievements are summarized here is six tables and annotated with references

Oceanography promotes self-recruitment in a planktonic larval disperser

The application of high-resolution genetic data has revealed that oceanographic connectivity in marine species with planktonic larvae can be surprisingly limited, even in the absence of major barriers to dispersal. Australia's southern coast represents a particularly interesting system for studying planktonic larval dispersal, as the hydrodynamic regime of the wide continental shelf has potential to facilitate onshore retention of larvae. We used a seascape genetics approach (the joint analysis of genetic data and oceanographic connectivity simulations) to assess population genetic structure and self-recruitment in a broadcast-spawning marine gastropod that exists as a single meta-population throughout its temperate Australian range. Levels of self-recruitment were surprisingly high, and oceanographic connectivity simulations indicated that this was a result of low-velocity nearshore currents promoting the retention of planktonic larvae in the vicinity of natal sites. Even though the model applied here is comparatively simple and assumes that the dispersal of planktonic larvae is passive, we find that oceanography alone is sufficient to explain the high levels of genetic structure and self-recruitment. Our study contributes to growing evidence that sophisticated larval behaviour is not a prerequisite for larval retention in the nearshore region in planktonic-developing species

Age-Associated Impairments in Mitochondrial ADP Sensitivity Contribute to Redox Stress in Senescent Human Skeletal Muscle.

This is the final version of the article. Available from Elsevier (Cell Press) via the DOI in this record.It remains unknown if mitochondrial bioenergetics are altered with aging in humans. We established an in vitro method to simultaneously determine mitochondrial respiration and H2O2emission in skeletal muscle tissue across a range of biologically relevant ADP concentrations. Using this approach, we provide evidence that, although the capacity for mitochondrial H2O2emission is not increased with aging, mitochondrial ADP sensitivity is impaired. This resulted in an increase in mitochondrial H2O2and the fraction of electron leak to H2O2, in the presence of virtually all ADP concentrations examined. Moreover, although prolonged resistance training in older individuals increased muscle mass, strength, and maximal mitochondrial respiration, exercise training did not alter H2O2emission rates in the presence of ADP, the fraction of electron leak to H2O2, or the redox state of the muscle. These data establish that a reduction in mitochondrial ADP sensitivity increases mitochondrial H2O2emission and contributes to age-associated redox stress.This work was funded by the Natural Sciences and Engineering Research Council of Canada (03656) and TI Food and Nutrition, a public-private partnership on precompetitive research in food and nutrition

Planetary Nebulae as Probes of Stellar Evolution and Populations

Planetary Nebulae (PNe) have been used satisfactory to test the effects of stellar evolution on the Galactic chemical environment. Moreover, a link exists between nebular morphology and stellar populations and evolution. We present the latest results on Galactic PN morphology, and an extension to a distance unbiased and homogeneous sample of Large Magellanic Cloud PNe. We show that PNe and their morphology may be successfully used as probes of stellar evolution and populations.Comment: to appear in: Chemical Evolution of the Milky Way: stars versus clusters, ed. F. Giovannelli and F. Matteucci, Kluwer (2000), in pres