Data management for JGOFS: Theory and design

The Joint Global Ocean Flux Study (JGOFS), currently being organized under the auspices of the Scientific Committee for Ocean Research (SCOR), is intended to be a decade long internationally coordinated program. The main goal of JGOFS is to determine and understand on a global scale the processes controlling the time-varying fluxes of carbon and associated biogenic elements in the ocean and to evaluate the related exchanges with the atmosphere, sea floor and continental boundaries. 'A long-term goal of JGOFS will be to establish strategies for observing, on long time scales, changes in ocean biogeochemical cycles in relation to climate change'. Participation from a large number of U.S. and foreign institutions is expected. JGOFS investigators have begun a set of time-series measurements and global surveys of a wide variety of biological, chemical and physical quantities, detailed process-oriented studies, satellite observations of ocean color and wind stress and modeling of the bio-geochemical processes. These experiments will generate data in amounts unprecedented in the biological and chemical communities; rapid and effortless exchange of these data will be important to the success of JGOFS

The Black-headed Gull Larus ridibundus in Irian Jaya

Gulls (Laridae) are a familiar group of birds at temperate and subtropical latitudes in both northern and southern hemispheres. However, they are rarely encountered in the tropics, particularly those of Asia and the Pacific. It is therefore interesting to note a group of 20 Black-headed Gulls Larus ridibundus apparently over-wintering in Sorong harbour at the extreme western tip of Irian Jaya (New Guinea) in January and February 1986

Rediscovery of Heinrich's Nightjar Eurostopodus diabolicus

Sulawesi, the largest island of Wallacea, Indonesia, supports a rich and distinctive avifauna that includes 10 endemic genera and 41 species (White & Bruce 1986, Coates & Bishop in press). Among the least known of these endemics is Heinrich's Nightjar Eurostopodus diabolicus (Caprimulgidae) (or Diabolical and/or Satanic Nightjar in some recent literature), known previously only from the unique type (Stresemann 1931, 1940). We now report its rediscovery and field observations

Globally optimal learning rates in multilayer neural networks

A method for calculating the globally optimal learning rate in on-line gradient-descent training of multilayer neural networks is presented. The method is based on a variational approach which maximizes the decrease in generalization error over a given time frame. We demonstrate the method by computing optimal learning rates in typical learning scenarios. The method can also be employed when different learning rates are allowed for different parameter vectors as well as to determine the relevance of related training algorithms based on modifications to the basic gradient descent rule

Intimal smooth muscle cells are a source but not a sensor of anti-inflammatory CYP450 derived oxylipins

AbstractVascular pathologies are associated with changes in the presence and expression of morphologically distinct vascular smooth muscle cells. In particular, in complex human vascular lesions and models of disease in pigs and rodents, an intimal smooth muscle cell (iSMC) which exhibits a stable epithelioid or rhomboid phenotype in culture is often found to be present in high numbers, and may represent the reemergence of a distinct developmental vascular smooth muscle cell phenotype. The CYP450-oxylipin - soluble epoxide hydrolase (sEH) pathway is currently of great interest in targeting for cardiovascular disease. sEH inhibitors limit the development of hypertension, diabetes, atherosclerosis and aneurysm formation in animal models. We have investigated the expression of CYP450-oxylipin-sEH pathway enzymes and their metabolites in paired intimal (iSMC) and medial (mSMC) cells isolated from rat aorta. iSMC basally released significantly larger amounts of epoxy-oxylipin CYP450 products from eicosapentaenoic acid > docosahexaenoic acid > arachidonic acid > linoleic acid, and expressed higher levels of CYP2C12, CYP2B1, but not CYP2J mRNA compared to mSMC. When stimulated with the pro-inflammatory TLR4 ligand LPS, epoxy-oxylipin production did not change greatly in iSMC. In contrast, LPS induced epoxy-oxylipin products in mSMC and induced CYP2J4. iSMC and mSMC express sEH which metabolizes primary epoxy-oxylipins to their dihydroxy-counterparts. The sEH inhibitors TPPU or AUDA inhibited LPS-induced NFκB activation and iNOS induction in mSMC, but had no effect on NFκB nuclear localization or inducible nitric oxide synthase in iSMC; effects which were recapitulated in part by addition of authentic epoxy-oxylipins. iSMCs are a rich source but not a sensor of anti-inflammatory epoxy-oxylipins. Complex lesions that contain high levels of iSMCs may be more resistant to the protective effects of sEH inhibitors

JMS: a workflow management system and web-based cluster front-end for the Torque resource manager

Complex computational pipelines are becoming a staple of modern scientific research. Often these pipelines are resource intensive and require days of computing time. In such cases, it makes sense to run them over distributed computer clusters where they can take advantage of the aggregated resources of many powerful computers. In addition to this, researchers often want to integrate their workflows into their own web servers. In these cases, software is needed to manage the submission of jobs from the web interface to the cluster and then return the results once the job has finished executing

Inference by replication in densely connected systems

An efficient Bayesian inference method for problems that can be mapped onto dense graphs is presented. The approach is based on message passing where messages are averaged over a large number of replicated variable systems exposed to the same evidential nodes. An assumption about the symmetry of the solutions is required for carrying out the averages; here we extend the previous derivation based on a replica symmetric (RS) like structure to include a more complex one-step replica symmetry breaking (1RSB)-like ansatz. To demonstrate the potential of the approach it is employed for studying critical properties of the Ising linear perceptron and for multiuser detection in Code Division Multiple Access (CDMA) under different noise models. Results obtained under the RS assumption in the non-critical regime give rise to a highly efficient signal detection algorithm in the context of CDMA; while in the critical regime one observes a first order transition line that ends in a continuous phase transition point. Finite size effects are also observed. While the 1RSB ansatz is not required for the original problems, it was applied to the CDMA signal detection problem with a more complex noise model that exhibits RSB behaviour, resulting in an improvement in performance.Comment: 47 pages, 7 figure

Possible soliton motion in ac-driven damped nonlinear lattices

We study the possibility of kink motion induced by pure ac driving in damped nonlinear lattices, focusing on the Frenkel-Kontorova and Toda models. Numerical simulations of the Frenkel-Kontorova model show no evidence for steady kink motion. We point out that momentum-balance in addition to energy-balance arguments are needed to understand the translation of the collective excitation. Finally, our result is discussed in view of related theoretical predictions and numerical simulations.Support from a MEC/Fulbright grant, from DGICyT (Spain) under Project No. PB92-0248, and from the European Union Network ERBCHRXCT930413. Work at Zaragoza was supported by DGICyT (Spain) under Project No. PB92-0361, and by the European Union (NETWORK on Nonlinear Approaches to Coherent and Fluctuating Processes in Condensed Matter and Optical Physics). Work at Los Alamos was performed under the auspices of the U.S. Department of Energy.Publicad

Analysis of superficial subcutaneous fat Camper\u27s and Scarpa\u27s fascia in a United States cohort

Together, the Camper\u27s and Scarpa\u27s fasciae form the superficial fat layer of the abdominal wall. Though they have clinical and surgical relevance, little is known about their role in body composition across diverse patient populations. This study aimed to determine the relationship between patient characteristics, including sex and body mass index, and the distribution of Camper\u27s and Scarpa\u27s fascial layers in the abdominal wall. A total of 458 patients\u27 abdominal CT examinations were segmented via CoreSlicer 1.0 to determine the surface area of each patient\u27s Camper\u27s, Scarpa\u27s, and visceral fascia layers. The reproducibility of segmentation was corroborated by an inter-rater analysis of segmented data for 20 randomly chosen patients divided between three study investigators. Pearson correlation and Student\u27s t-test analyses were performed to characterize the relationship between fascia distribution and demographic factors. The ratios of Camper\u27s fascia, both as a proportion of superficial fat (r = -0.44 an