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Priority versus brute force: When should males begin guarding resources?

When should males begin guarding a resource when both resources and guarders vary in quality? This general problem applies, for example, to migrant birds occupying territories in the spring and to precopula in crustaceans where males grab females before they molt and become receptive. Previous work has produced conflicting predictions. Theory on migrant birds predicts that the strongest competitor

Pronounced phylogeographic structure on a small spatial scale: Geomorphological evolution and lineage history in the salamander ring species Ensatina eschscholtzii in central coastal California

The salamander Ensatina eschscholtzii is a classic example of a ring species, and has an intricate biogeographic history. Within a part of the ring distribution, earlier work using allozymes disclosed high levels of genetic structure in central coastal California, where the subspecies oregonensis, xanthoptica, and eschscholtzii meet. We used mitochondrial cytochrome b sequences to further examine

Quantitation of repetitive epitopes in glycosaminoglycans immobilized on hydrophobic membranes treated with cationic detergents

Glycosaminoglycans (GAGs) are linear carbohydrate polymers containing repetitive sequences of differently sulfated uronic acid and glycosamine residues that are recognized by antibodies raised against proteoglycans. We have developed a method to demonstrate such repetitive sequence motifs in isolated GAG chains immobilized on hydrophobic membranes derivatized with cationic detergents. Six monoclon

Comparison of operative and endovascular treatment of anterior circulation aneurysms in patients in poor grades

We assessed the outcome of surgical and endovascular treatment in patients in poor (Hunt & Hess IV or V) grade following subarachnoid haemorrhage due to anterior circulation aneurysm (ACA). There were 41 patients, treated surgically (20), by the endovascular route (20) or both (1). The aneurysms were clipped in 20 patients, wrapped in one; 19 were treated with Guglielmi detachable coils (GDC),

An overview of an architecture proposal for a high energy physics grid

This document gives an overview of a Grid testbed architecture proposal for the NorduGrid project [1]. The aim of the project is to establish an inter-Nordic(1) testbed facility for implementation of wide a,rea computing and data handling. The architecture is supposed to define a Grid system suitable for solving data intensive problems at the Large Hadron Collider at CERN [2]. We present the vario

Antagonism of the prostaglandin D2 receptor CRTH2 attenuates asthma pathology in mouse eosinophilic airway inflammation.

Background: Mast cell-derived prostaglandin D-2 (PGD(2)), may contribute to eosinophilic inflammation and mucus production in allergic asthma. Chemoattractant receptor homologous molecule expressed on TH2 cells (CRTH2), a high affinity receptor for prostaglandin D-2, mediates trafficking of TH2-cells, mast cells, and eosinophils to inflammatory sites, and has recently attracted interest as target

Effects of long term NOS inhibition on disease and the immune system in MOG induced EAE

Hypothesising that systemically and intrathecally produced nitric oxide might play different roles in the EAE pathogenesis, we administered the NOS inhibitor N-nitro-methyl-L-arginine-ester intrathecally or systemically via osmotic minipumps to DA rats with MOG induced EAE. We demonstrate an protective effect of the NOS inhibitor on EAE severity, the extent of CNS inflammation, and demyelination.

Endogenous versus exogenous exposure to N-nitroso compounds and gastric cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC-EURGAST) study

The risk of gastric cancer (GC) associated with dietary intake of nitrosodimethylamine (NDMA) and endogenous formation of nitroso compounds (NOCs) was investigated in the European Prospective Investigation into Cancer and Nutrition (EPIC). The study included 521 457 individuals and 314 incident cases of GC that had occurred after 6.6 average years of follow-up. An index of endogenous NOC (ENOC) fo

Chronically administered islet amyloid polypeptide in rats serves as an adiposity inhibitor and regulates energy homeostasis

Aims/Hypothesis: Islet amyloid polypeptide ( IAPP) reduces food intake and body weight in laboratory animals. In addition, IAPP appears to regulate nutrient metabolism. In the present studies, we investigated the effect of chronic IAPP treatment on different aspects of energy homeostasis. Methods: IAPP was infused ( 25 pmol/kg/min) from subcutaneous osmotic pumps for 2 - 7 days. Rats in 2 saline-i

Gene marking of human neural stem/precursor cells using green fluorescent proteins

Background Ex vivo gene therapy and cell replacement in the nervous system may provide therapeutic opportunities for neurodegenerative disorders. The development of optimal gene marking procedures for human neural stem cells (hNSCs) is crucial for the success of these strategies, in order to provide a correct understanding of the biology of transplanted cells. Methods hNSCs were modified to expres

Vibration spectroscopy study of phenylphosphonate at the water-aluminum (hydr)oxide interface

Two previously published surface complexation models of phenylphosphonate on aged gamma-Al2O3 and boehmite (gamma-AlOOH), respectively, have been examined by means of FTIR and FT-Raman spectroscopy. The spectral features of adsorbed phenylphosphonate were studied as a function of pH and total phenylphosphonate concentration. No evidence for a phase transformation into a three-dimensional aluminum

Experimental evidence for evaporation/condensation nonuniform flow in a horizontal aerosol generator

The formation of deposition patterns in the cooling zone during operation of a horizontal evaporation/condensation nanoparticle generator was studied to obtain information about flow conditions during particle formation. Quartz reactor tubes were used together with a simple light attenuation measurement to characterize deposition as a function of axial location. Results for the onset and pattern o

Twilight orientation to polarised light in the crepuscular dung beetle Scarabaeus zambesianus

The polarisation pattern of skylight offers many arthropods a reference for visual compass orientation. The dung beetle Scarabaeus zambesianus starts foraging at around sunset. After locating a source of fresh droppings, it forms a ball of dung and rolls it off at high speed to escape competition at and around the dung pile. Using behavioural experiments in the field and in the laboratory, we show

Short gamma-ray bursts in old populations: magnetars from white dwarf-white dwarf mergers

Recent progress on the nature of short-duration gamma-ray bursts has shown that a fraction of them originate in the local Universe. These systems may well be the result of giant flares from soft gamma-repeaters (highly magnetized neutron stars commonly known as magnetars). However, if these neutron stars are formed via the core collapse of massive stars then it would be expected that the bursts sh

Properties of RF bandpass amplifier topology with Q-enhancing

This paper describes a bandpass amplifier topology for the GHz range using Q-enhancing that allows a systematic design approach to be used to control linearity, noise and power consumption. Frequency selectivity is achieved by a negative feedback network using a LC tank and a positive feedback networks using a resistor to achieve Q-enhancing. The feedback networks are fully passive in order to min

Results of hip revision using the Exeter stem, impacted allograft bone, and cement

The Exeter stem and impacted, morselized allograft bone and cement were used in the revisions of 18 consecutive femoral components (17 patients). The primary arthroplasty had been done because of osteoarthritis. All of the femoral components were revised for the first time because of aseptic loosening. The migration pattern of the Exeter stem after revision was studied using roentgen stereophotogr

Physics based on electron beam ion traps

A brief description of the operational principles of an Electron Beam Ion Trap is given with specific reference to the currently under development/construction Shanghai EBIT. This is followed by an introduction to some of the frontier physics problems of highly charged ions that can be studied with such devices. Also a discussion of the use of EBITs as a powerful tool in hot-plasma diagnostics is