Physical Control of Biological Processes in the Central Equatorial Pacific: A Data Assimilative Modeling Study

A five-component data assimilative ecosystem model is developed in order to investigate the effects of physical processes encompassing a wide range of space and time scales, on the lower trophic levels of the highly dynamic central equatorial Pacific (140°W). Many of the biological processes included in the ecosystem model respond to environmental fluctuations with time scales between one and ten days, which are not typically resolved by basin to global scale circulation models. Therefore, the ecosystem model is forced using daily observations from the TAO mooring array. Model simulations successfully reproduce data collected both during and after the 1991–92 El Niño, suggesting that species composition changes are not of first order importance when examining the effects of this El Niño on the equatorial Pacific ecosystem. Simulations also highlight the importance of higher frequency mesoscale events, such as tropical instability waves and equatorially-trapped internal gravity waves. The feasibility of improving simulation skill by assimilating biogeochemical observations, is also examined. The adjoint method, which minimizes model/data misfits by adjusting model parameters, provides a viable option for assimilating data into marine ecosystem models. When assimilating synthetic data subsampled using the resolution of the JGOFS EqPac cruises, parameters governing processes such as grazing, growth, mortality and recycling can be recovered exactly. The assimilation of phytoplankton time-series data, as are currently available from SeaWiFS, additionally requires a small amount of supplemental in situnutrient data. As expected, deterioration in simulation skill is more severe when assimilating biased data, as compared to data containing random noise. When actual EqPac cruise data and SeaWiFS ocean color data are assimilated, one can objectively determine whether or not a given model structure is consistent with specific sets of observations. For instance, a brief period of macro-nutrient limitation during the 1997–98 El Niño, as well as changes in species composition observed during the passage of a tropical instability wave, are found to violate key model assumptions. Thus, although the assimilation of biological data into a marine ecosystem model cannot necessarily overcome inappropriate model dynamics, data assimilation can often serve to guide model reformulation

Following the Fugitive: Reflections on the Concept of Memorial Routes and the Possibilities of Representing Escape

Carnet de recherche Europe across border

Reference values: a review

Reference values are used to describe the dispersion of variables in healthy individuals. They are usually reported as population-based reference intervals (RIs) comprising 95% of the healthy population. International recommendations state the preferred method as a priori nonparametric determination from at least 120 reference individuals, but acceptable alternative methods include transference or validation from previously established RIs. The most critical steps in the determination of reference values are the selection of reference individuals based on extensively documented inclusion and exclusion criteria and the use of quality-controlled analytical procedures. When only small numbers of values are available, RIs can be estimated by new methods, but reference limits thus obtained may be highly imprecise. These recommendations are a challenge in veterinary clinical pathology, especially when only small numbers of reference individuals are available

Migrations and Borders: Practices and Politics of Inclusion and Exclusion in Europe from the Nineteenth to the Twenty-first Century

Current media images of a “fortress Europe” suggest that migrations and borders are closely connected. This special issue brings together scholars from history, sociology and anthropology to explore cross-border mobility and migration during the formation, development, and transformation of the modern (nation-)state explicating the conflictive and fluctuating character of borders. The historical perspective demonstrates that such bordering processes are not new. However, they have developed new dynamics in different historical phases, from the formation of the modern (nation-)state in the nineteenth century to the creation of the European Union during the second half of the twentieth. This introduction explains the dynamic relationships between borders and migratory movements in Europe from the nineteenth century to the present by approaching them from four different, overlapping angles, which the articles analyze in more detail: (1) the multiple actors involved, (2) scales and places of borders and their crossings, (3) the instruments and techniques employed, and (4) the significance of social categories. Focusing on the historical, local specificity of the complex relations between migration and boundaries will help denaturalize the concept of the border as well as further reflection on the shifting definitions of migration and belonging

Safety of a new extensively hydrolysed formula in children with cow's milk protein allergy: a double blind crossover study

BACKGROUND: Formulae for infants with cow's milk protein allergy (CMA) should be based on extensively hydrolysed protein. 'Extensively' however is not strictly defined. Differences in molecular weight and peptide chain length may affect its clinical outcome. We studied the safety of a new extensively hydrolysed casein based formula (Frisolac Allergycare(®): FAC) for children with IgE mediated CMA. METHODS: Thirty children, aged 1.5 – 14.8 years old (median 4.9 years) with persistent CMA were enrolled in this double-blind reference product (Nutramigen(®): NUT) controlled crossover study. All had positive skin prick tests (SPT) and IgE mediated allergy, showing immediate reactions after ingestion of small amounts of milk. Twenty-five children also had positive radio allergen sorbent tests (RAST) to cow's milk. Formulae provided consisted of 80% elementary formula in combination with 20% reference or test product. Crossover periods lasted for two weeks. From both products molecular weight (MALDI-TOF method and HPLC) and peptide chain length distribution (adapted Edman degradation) were determined. RESULTS: Maximum molecular weights of NUT and FAC are 2.1 and 2.56 kDa, respectively. The contribution of free amino acids and small peptides <0.5 kDa is 46% for FAC and 53% for NUT. About 50% of the protein fraction of both products consists of peptides longer than four amino acids. Three children did not complete the study. The other children all tolerated FAC very well; no adverse reactions were reported. CONCLUSIONS: The new extensively hydrolysed casein-based formula (FAC) can safely be used in children with IgE mediated cow's milk allergy

Establishing a yard specific normal rectal temperature reference range for horses

Previously published equine temperature ranges often fail to state the population of animals or the method of temperature measurement used to establish the range. An inappropriate reference range can negatively affect the interpretation of measurements, resulting in animals being misdiagnosed. A yard specific equine rectal temperature reference range was therefore calculated. 652 rectal temperatures were collected from a population of 41 healthy adult horses, including a range of breeds aged 2-23 years old. Rectal temperature was measured at a depth of 5cm, using lubricated digital predictive thermometers. The normal rectal temperature range of horses on this yard was 36.0 – 38.0°C (90% confidence interval [CI] = 35.97–36.03°C at the lower limit, CI = 37.97–38.03°C at the upper limit). A Mann Whitney test showed significant difference between geldings and mares (Z = -1.389, p = 0.165). Spearman’s correlation showed no significant correlations between rectal temperature and ambient temperature (Rs = 0.137, p = 0.052), or rectal temperature and horse height (Rs = -0.047, p = 0.791). The upper limit of the range is lower than most previously suggested temperature ranges, which may reflect the low stress environment in which temperatures were measured; horses were housed in a familiar environment and examined and handled by familiar equine technicians. The findings of this study suggest that establishing yard specific normal temperature ranges could improve early detection of fever, and support biosecurity protocols in the face of infectious disease outbreaks. Additionally, the results suggest that existing equine temperature ranges may need reviewing

Common Variants of the Genes Encoding Erythropoietin and Its Receptor Modulate Cognitive Performance in Schizophrenia

Erythropoietin (EPO) improves cognitive performance in clinical studies and rodent experiments. We hypothesized that an intrinsic role of EPO for cognition exists, with particular relevance in situations of cognitive decline, which is reflected by associations of EPO and EPO receptor (EPOR) genotypes with cognitive functions. To prove this hypothesis, schizophrenic patients (N > 1000) were genotyped for 5′ upstream-located gene variants, EPO SNP rs1617640 (T/G) and EPOR STR(GA)n. Associations of these variants were obtained for cognitive processing speed, fine motor skills and short-term memory readouts, with one particular combination of genotypes superior to all others (p 800), these associations were confirmed. A matching preclinical study with mice demonstrated cognitive processing speed and memory enhanced upon transgenic expression of constitutively active EPOR in pyramidal neurons of cortex and hippocampus. We thus predicted that the human genotypes associated with better cognition would reflect gain-of-function effects. Indeed, reporter gene assays and quantitative transcriptional analysis of peripheral blood mononuclear cells showed genotype-dependent EPO/EPOR expression differences. Together, these findings reveal a role of endogenous EPO/EPOR for cognition, at least in schizophrenic patients