56 research outputs found
Solar System Abundances of the Elements
Representative abundances of the chemical elements for use as a solar
abundance standard in astronomical and planetary studies are summarized.
Updated abundance tables for solar system abundances based on meteorites and
photospheric measurements are presented.Comment: 46 pages; 5 figures; 8 tables; In: Principles and Perspectives in
Cosmochemistry.Lecture Notes of the Kodai School on 'Synthesis of Elements in
Stars' held at Kodaikanal Observatory, India, April 29 - May 13, 2008 (Aruna
Goswami and B. Eswar Reddy eds.) Astrophysics and Space Science Proceedings,
Springer-Verlag Berlin Heidelberg, 2010, p. 379-417 (ISBN 978-3-642-10351-3),
201
Concepts for risk-based surveillance in the field of veterinary medicine and veterinary public health: Review of current approaches
BACKGROUND: Emerging animal and zoonotic diseases and increasing international trade have resulted in an increased demand for veterinary surveillance systems. However, human and financial resources available to support government veterinary services are becoming more and more limited in many countries world-wide. Intuitively, issues that present higher risks merit higher priority for surveillance resources as investments will yield higher benefit-cost ratios. The rapid rate of acceptance of this core concept of risk-based surveillance has outpaced the development of its theoretical and practical bases. DISCUSSION: The principal objectives of risk-based veterinary surveillance are to identify surveillance needs to protect the health of livestock and consumers, to set priorities, and to allocate resources effectively and efficiently. An important goal is to achieve a higher benefit-cost ratio with existing or reduced resources. We propose to define risk-based surveillance systems as those that apply risk assessment methods in different steps of traditional surveillance design for early detection and management of diseases or hazards. In risk-based designs, public health, economic and trade consequences of diseases play an important role in selection of diseases or hazards. Furthermore, certain strata of the population of interest have a higher probability to be sampled for detection of diseases or hazards. Evaluation of risk-based surveillance systems shall prove that the efficacy of risk-based systems is equal or higher than traditional systems; however, the efficiency (benefit-cost ratio) shall be higher in risk-based surveillance systems. SUMMARY: Risk-based surveillance considerations are useful to support both strategic and operational decision making. This article highlights applications of risk-based surveillance systems in the veterinary field including food safety. Examples are provided for risk-based hazard selection, risk-based selection of sampling strata as well as sample size calculation based on risk considerations
Attachment as an organizer of behavior: implications for substance abuse problems and willingness to seek treatment
BACKGROUND: Attachment theory allows specific predictions about the role of attachment representations in organizing behavior. Insecure attachment is hypothesized to predict maladaptive emotional regulation whereas secure attachment is hypothesized to predict adaptive emotional regulation. In this paper, we test specific hypotheses about the role of attachment representations in substance abuse/dependence and treatment participation. Based on theory, we expect divergence between levels of maladaptive functioning and adaptive methods of regulating negative emotions. METHODS: Participants for this study consist of a sample of adoptees participating in an ongoing longitudinal adoption study (n = 208). The Semi-Structured Assessment of the Genetics of Alcohol-II [41] was used to determine lifetime substance abuse/dependence and treatment participation. Attachment representations were derived by the Adult Attachment Interview [AAI; [16]]. We constructed a prior contrasts reflecting theoretical predictions for the association between attachment representations, substance abuse/dependence and treatment participation. RESULTS: Logistic regression was used to test our hypotheses. As predicted, individuals classified as dismissing, preoccupied or earned-secure reported the highest rates of substance abuse/dependence. Individuals classified as dismissing reported significantly lower rates of treatment participation despite their high rates of substance abuse/dependence. As expected, the continuous-secure group reported lowest rates of both substance abuse/dependence and treatment participation. CONCLUSION: The findings from this study identify attachment representations as an influential factor in understanding the divergence between problematic substance use and treatment utilization. The findings further imply that treatment may need to take attachment representations into account to promote successful recovery
Ubiquitous healthy diatoms in the deep sea confirm deep carbon injection by the biological pump
The role of the ocean as a sink for CO2 is partially dependent on the downward transport of phytoplankton cells packaged within fast-sinking particles. However, whether such fast-sinking mechanisms deliver fresh organic carbon down to the deep bathypelagic sea and whether this mechanism is prevalent across the ocean requires confirmation. Here we report the ubiquitous presence of healthy photosynthetic cells, dominated by diatoms, down to 4,000 m in the deep dark ocean. Decay experiments with surface phytoplankton suggested that the large proportion (18%) of healthy photosynthetic cells observed, on average, in the dark ocean, requires transport times from a few days to a few weeks, corresponding to sinking rates (124–732 m d−1) comparable to those of fast-sinking aggregates and faecal pellets. These results confirm the expectation that fast-sinking mechanisms inject fresh organic carbon into the deep sea and that this is a prevalent process operating across the global oligotrophic ocean
Synthetic biology: Understanding biological design from synthetic circuits
An important aim of synthetic biology is to uncover the design principles of natural biological systems through the rational design of gene and protein circuits. Here, we highlight how the process of engineering biological systems — from synthetic promoters to the control of cell–cell interactions — has contributed to our understanding of how endogenous systems are put together and function. Synthetic biological devices allow us to grasp intuitively the ranges of behaviour generated by simple biological circuits, such as linear cascades and interlocking feedback loops, as well as to exert control over natural processes, such as gene expression and population dynamics
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