bluuebunny/crossref_metadata_2025_split huggingface dataset:
The absolute positioning of spaceborne INSAR data using the integer ambiguity method
Authors: Sowter Andrew , Warren Mark A. , Bingley Richard M. 
Published: February 2006

AbstractIn this paper, the capability of the integer ambiguity method to find the absolute position of InSAR data is demonstrated. A radargrammetric model is used for the space triangulation. The method is demonstrated using ERS data of the Thames region and the results are compared to GPS measurements and a digital elevation model. The GPS stations, not visible in the image, are located on the InSAR data using a simple range‐Doppler algorithm and an analysis of their positions is undertaken. The results are consistent with other methods but with the advantage that the radargrammetric model is very simple. The results also highlight the problems of integrating GPS data with InSAR data in urban areas where a GPS station may not be representative of the dominant scatterers within a resolution cell, and they suggest methods that might be applied in future to reduce this problem. The model should help the integration of InSAR data with other geometric survey data.
A review of invertebrates and seed‐bearing plants as food for farmland birds in Europe
Authors: Holland J.M. , Hutchison M.A.S. , Smith B. , Aebischer N.J. 
Published: February 2006

AbstractDietary information was reviewed for 22 bird species typically found in farmland areas across Europe using 100 references from the UK and other European countries for which quantitative data were presented. The number of studies and degree of taxonomic resolution available varied considerably between the species and, for some, dietary information was only available prior to agricultural intensification and may be unrepresentative of current feeding habits. Consequently, some caution is required in interpreting the results because of the different methods of data collection between the studies and the biases in analytical techniques for prey detectability. Food availability was rarely quantified in the study areas, and diet may have reflected availability or preference. Plant families and invertebrate orders were ranked in their importance separately for adult diet in the breeding and nonbreeding seasons and for chicks. The most important plant families overall were Poaceae, Polygonaceae, Caryophyllaceae, Cruciferae, Compositae, Chenopodiaceae and Labiatae, although the last two were unimportant for chicks. A number of key species were also identified. Similarities in dietary preferences were observed among Fringillidae (finches) and members of the Columbidae (doves and pigeons). Fringillidae andCarduelis cannabina(linnet) were associated with plants that occur in seminatural habitats, whileEmberiza citrinella(yellowhammer), Phasianidae (partridges) and Columbidae were shown to be more closely associated with plants of agricultural environments. The most important invertebrate orders overall were Coleoptera adults, Hemiptera adults, Arachnida, Lepidoptera larvae/pupae, Diptera adults, Lepidoptera adults, Diptera larvae/pupae and Hymenoptera adults. During the nonbreeding season, a smaller number of invertebrate taxa were important. For adults in the breeding season and for chicks, there were 10 families of invertebrate that were important for four or more bird species (Aphididae, Carabidae, Chrysomelidae, Curculionidae, Elateridae, Formicidae, Scarabeidae, Staphylinidae, Tenthredinidae and Tipulidae). In the nonbreeding season, Curculionidae and Lumbricidae were important in the diet of three species. A few species exhibited a narrow diet range, selecting invertebrates from only one or two families. Similarities in dietary composition were observed among closely related bird species, while that of chicks and adults sometimes differed.
Distribution of Rupestris stem‐pitting‐associated virus variants in two Australian vineyards showing different symptoms
Authors: Habili N. , Farrokhi N. , Lima M.F. , Nicholas P. , Randles J.W. 
Published: February 2006

AbstractThe incidence of Rupestris stem‐pitting‐associated virus (RSPaV) in two vineyards in South Australia was studied by comparing symptoms with the results obtained from biological indexing and from virus detection by reverse‐transcription‐polymerase chain reaction (RT‐PCR). Vineyard 1 was an experimental block comprising a number of varieties grafted onto Vitis rupestris cv. St George rootstocks for the detection of Rupestris stem pitting disease. No swelling at graft union or decline was observed at 3 years, but some vines showed pitting on the rootstock trunk. Vineyard 2 contained Vitis vinifera cv. Shiraz (Syn. Syrah) vines on Paulsen 1103 rootstock, showing a range of symptoms including swelling of the graft union, pitting on the rootstock, leaf reddening and vine decline, resembling those in Syrah Decline, a disorder known to occur in this variety. RT‐PCR using the coat‐protein‐specific primers detected RSPaV in all samples from either vineyard including symptomless V. rupestris cv. St George, which is used as the biological indicator for the virus. In contrast, a pair of primers designed from the replicase gene detected the virus only in symptomatic vines, whereas the symptomless St George control and nonsymptomatic vines in both vineyards tested negative. An assay for 12 other major grapevine viruses showed that none were associated with either type of symptom. Comparison of a 628‐bp amplicon on the replicase gene in 13 RSPaV isolates showed that while they had 96–99% nucleotide sequence identity to each other, their identity to the American isolates from California and New York was around 65%. This low homology may indicate that a different virus species is present. The variability was more pronounced between the two vineyards than among the virus isolates in the Shiraz vines within the same vineyard. However, even the vines of the same vineyard did not contain viruses with exactly the same sequence homology. We found no association between the type of symptom expressed and the sequence variation in the amplicons in either vineyard. The sequence variants in Vineyard 1 showed a closer cluster than in Vineyard 2.
Immunomodulatory Properties of Interferon‐γ: An Updatea
Authors: BILLIAU ALFONS , HEREMANS HUBERTINE , VERMEIRE KURT , MATTHYS PATRICK 
Published: February 2006

ABSTRACT:During the early aspecific phase of host defense, production of interferon (IFN)‐γ by natural killer cells plays an important role in bringing about acute inflammation, mainly because of the activating effects of IFN‐γ on adhesive properties of endothelial cells and on mediator production by mononuclear phagocytes (MPCs). In the subsequent antigen‐specific phase of the immune response, IFN‐γ acts as a regulator of antigen presentation and of proliferation and differentiation of lymphocyte populations. Immunosuppressive as well as immunostimulatory effects may result from these actions.High‐level production of IFN‐γ during this phase of host defense is now classically seen as a hallmark of a T‐helper 1 (TH1)‐type reaction, characterized by activation of antimicrobial activity of macrophages and by inflammatory reactions with a DTH character. Development of TH1‐type lymphocyte populations producing IFN‐γ is regulated by other cytokines including interleukin (IL)‐12. In many systems IL‐12 and IFN‐γ act in a similar fashion, and a current subject of debate is the question of whether all activities of IL‐12 are mediated by IFN‐γ. Another question is whether IFN‐γ, by its ability to potentiate MPCs' ability to produce IL‐12, plays a role in bringing about or stabilizing TH1 type responses. In two model systems of autoimmune disease, experimental autoimmune encephalomyelitis and collagen‐induced arthritis, IL‐12 and IFN‐γ were found to act independently.
Intersegmental Coordination of Swimmeret Movements: Mathematical Models and Neural Circuitsa
Authors: MULLONEY BRIAN , SKINNER FRANCES K. , NAMBA HISAAKI , HALL WENDY M. 
Published: February 2006

Abstract: Swimmerets move periodically through a cycle of power‐strokes and return‐strokes. Swimmerets on neighboring segments differ in phase by ~25%, and maintain this difference even when the period of the cycle changes from < 1 to >4 Hz. We constructed a minimal cellular model of the segmental pattern‐generating circuit which incorporated its essential components, and whose dynamics were like those of the local circuit. Three different intersegmental coordinating units were known to link neighboring ganglia, but their targets are unknown. We constructed different intersegmental circuits which these units might form between neighboring cellular models, and compared their dynamics with the real system. One intersegmental circuit could maintain an ~25% phase difference through a range of periods.In physiological experiments, we identified three types of intersegmental interneurons that originate in each ganglion and project to its neighbors. These neurons fire bursts at certain parts of the swimmeret cycle in their home ganglion. These three neurons are necessary and sufficient to maintain normal coordination between neighboring segments. Their properties conform to the predictions of the cellular model.
Development and Aminergic Neuromodulation of a Spinal Locomotor Network Controlling Swimming in Xenopus Larvaea
Authors: SILLAR KEITH T. , REITH CAROLYN A. , McDEARMID JOE R. 
Published: February 2006

Abstract: In this article we review our research on the development and intrinsic neuromodulation of a spinal network controlling locomotion in a simple ventral roovertebrate. Swimming in hatchling Xenopus embryos is generated by a restricted network of well‐characterized spinal neurons. This network produces a stereotyped motor pattern which, like real swimming, involves rhythmic activity that alternates across the body and progresses rostrocaudally with a brief delay between muscle segments. The stereotypy results from motoneurons discharging a single impulse in each cycle; because all motoneurons appear to behave similarly there is little scope for altering the output to the myotomes from one cycle to the next. Just one day later, however, Xenopus larvae generate a more complex and flexible motor pattern in which motoneurons can discharge a variable number of impulses which contribute to ventral root bursts in each cycle.This maturation of swimming is due, in part, to the influence of serotonin released from brain‐stem raphespinal interneurons whose axonal projections innervate the cord early in larval life. Larval swimming is differentially modulated by both serotonin and by noradrenaline: serotonin leads to relatively fast, intense swimming whereas noradrenaline favors slower, weaker activity. Thus, these two biogenic amines select opposite extremes from the spectrum of possible output patterns that the swimming network can produce. Our studies on the cellular and synaptic effects of the amines indicate that they can control the strength of reciprocal glycinergic inhibition in the spinal cord. Serotonin and noradrenaline act presynaptically on the terminals of glycinergic commissural interneurons to weaken and strengthen, respectively, crossed glycinergic inhibition during swimming. As a result, serotonin reduces and noradrenaline increases interburst intervals. The membrane properties of spinal neurons are also affected by the amines. In particular, serotonin can induce intrinsic oscillatory membrane properties in the presence of NMDA. These depolarizations are slow compared to the cycle periods during swimming and so may contribute to enhancement of swimming over several consecutive cycles of activity.
Guillain‐Barré Syndrome and Fisher's Syndrome Following Campylobacter jejuni Infectiona
Authors: YUKI NOBUHIRO , MIYATAKE TADASHI 
Published: February 2006

ABSTRACT: The patients with Guillain‐Barré Syndrome (GBS) subsequent to Campylobacter jejuni enteritis showed axonal degeneration and had IgG anti‐GM1 antibody. The most frequently isolated C. jejuni from the patients was specific serotype of Penner's 19 in Japan. In the lipopolysaccharide (LPS) in C. jejuni of this serotype, the same oligosaccharide structure as GM1 ganglioside existed, suggesting the molecular mimicry between GM1 in nervous tissue and C. jejuni LPS. IgG anti‐GM1 antibody may bind the nodes of Ranvier and axon terminals and causes degeneration of the motor axon.Some patients develop Fisher's syndrome following C. jejuni infection. C. jejuni strains from the patients who had IgG anti‐GQ1b antibody in the acute phase had GQ1b epitope in their LPS, and the molecular mimicry between GQ1b in nervous tissue and an antecedent infectious agent was clarified.
Scanning Tunneling Microscopy (STM) on Physisorbed Chemical Groups of Individual Immobilized Molecules
Authors: MANASSEN YISHAY , SHACHAL DOV 
Published: February 2006

ABSTRACT: Most scanning tunneling microscopy (STM) studies of adsorbed molecules are performed either on molecules that are chemically bound to the surface or are part of a molecular monolayer. In the first case, the chemical reaction with the surface changes the surface local density of states. In the second one, the electrons tunnel through a physisorbed molecule. In the study described in this paper STM imaging is performed on isolated molecules immobilized on a clean semiconductor surface where atomic resolution is observed. This is an intermediate case.The adsorption behavior of diene molecules on Si(111)7 × 7 was investigated. The molecules adsorb by reaction of the double bonds on the surface. In the reaction, the C=C bond is opened to create two neighboring Si‐C bonds. Two such C‐C bonds are used to immobilize the chain to the surface. The adsorption chemistry is affected not only by the nature of the Si‐C bond but also by steric limitations.Performing STM imaging on such systems ensures that the position of the immobilized chemical group (in this case an aliphatic chain) could be clearly identified and that it was possible to image parts of the molecule that are not chemically bound to the surface. STM images of 1,13‐tetradecadiene revealed a white protrusion in the location of the aliphatic chain. The increase in transmission is explained by an additional channel for tunneling: through bond tunneling. Long‐range electron transfer through molecules is a widely known chemical and biochemical process. This observation opens the possibility to investigate this fundamental phenomenon in large details. The potential applications for molecular electronics are discussed.
Telomeres: Influencing the Rate of Aging
Authors: VON ZGLINICKI THOMAS 
Published: February 2006

ABSTRACT: Evidence is reviewed that suggests a central role for telomeres in one major model of biological aging, namely, proliferative senescence. Telomeric shortening with each cell division does not only act as a biological clock, but appears to trigger the ultimate loss of proliferative ability via activation of the p53‐dependent check point system.Oxidative stress induces single‐stranded damage in telomeric DNA. It is not clear yet whether this damage occurs in the form of single‐stranded gaps or overhangs or as arbitrarily distributed single‐stranded breaks. However, in contradiction to the rest of the genome, this damage is not repaired in telomeres. It is, therefore, the major cause of telomere shortening even under standard in vitro cell culture conditions. Therefore, controlling the oxidative load onto DNA, in general, and, especially, onto telomeres might become a major factor to influence the rate of aging.Further experiments demonstrate that G‐rich single‐stranded telomeric DNA fragments do activate the p53 check point control, leading to an inhibition of proliferation in wild‐type p53 cells. Not only the shortening of telomeres down to a “signal value,” but accumulation of telomeric single‐stranded DNA fragments, as well, could be relevant triggers for proliferative senescence.
B Vitamins and Homocysteine in Cardiovascular Disease and Aging
Authors: WILCKEN DAVID E. L. , WILCKEN BRIDGET 
Published: February 2006

ABSTRACT: The sulfur‐containing amino acid, homocysteine, is formed from the essential amino acid methionine, and a number of B vitamins are involved in methionine metabolism. Pyridoxine, vitamin B6, is a cofactor for cystathionine β synthase, which mediates the transformation of homocysteine to cystathionine, the initial step in the transsulfuration pathway and the urinary excretion of sulfur. In a normal diet there is conservation of the carbon skeleton, and about 50% of the homocysteine formed is remethylated to methionine via steps that require folic acid and vitamin B12. A deficiency of any of these three vitamins leads to modest homocyst(e)ine elevation, as does diminished renal function, both of which are common in the elderly. It is also established that homocyst(e)ine elevation of this order is associated with increased cardiovascular risk but is also associated with most established risk factors, although it is thought to be an independent contributor.In the inborn error of metabolism homocystinuria due to cystathionine β synthase deficiency there is greatly increased circulating homocyst(e)ine and a clear association with precocious vascular disease. In about 50% of these patients there is a vascular event before the age of 30 years. The homocysteine‐induced adverse vascular changes appear to result from endothelial and smooth muscle cell effects and increased thrombogenesis. We have documented a highly significant reduction in the occurrence of vascular events during 539 patient years of treatment in 32 patients with cystathionine β synthase deficiency (mean age 30 years, range 9‐66 years) by aggressive homocyst(e)ine lowering with pyridoxine, folic acid, and B12 (
p = 0.0001
). The 15 pyridoxine nonresponsive patients also received oral betaine.Although a cause and effect relationship is postulated for the increased cardiovascular risk associated with mild homocysteine elevation, a common cause of this elevation is the methylenetetrahydrofolate reductase C677T mutation. Homozygotes occur in about 11% of Caucasian populations. However, the mutation is not associated with increased coronary risk. Since mild homocysteine elevation is easily normalized by B vitamin supplementation, usually with folic acid, it remains for controlled clinical trials of this inexpensive therapy to determine whether normalizing mild homocyst(e)ine elevation reduces cardiovascular risk.
Nutrition, Cancer, and Aging
Authors: DREOSTI IVOR E. 
Published: February 2006

ABSTRACT:The parallel increase in cancer risk with advancing age is well recognized, and several pathophysiological mechanisms common to both conditions have been proposed to explain this interrelationship. The importance of nutrition, both in delaying the aging process and in protecting against cancer is also well recognized, and it is therefore of interest to compare the relative impact several of the more widely studied dietary manipulations may have on each of these conditions.For example, caloric restriction, which putatively reduces oxidative stress and effectively increases life span in animals also seems to reduce the incidence of many cancers, possibly due to diminished mitogenesis. Likewise, oxidative damage to DNA appears to be common to both processes but may be more important in the mitochondria with respect to aging and in the nucleus in relation to cancer. Inadequate dietary folate and impaired DNA methylation status are closely associated with increased cancer risk, and recently defective somatic cell methylation and accumulated genetic instability have been proposed as key mechanisms contributing to senescence.Several other well‐established anticancer dietary strategies, which include increased fiber intake and the consumption of more fruits and vegetables, have not been studied extensively in relation to aging, although many of the phytochemicals considered important as chemopreventive agents for cancer may well contribute to delaying the aging process.Although not directly related to nutrition, but nevertheless highly relevant, is the question of physical activity, which has been strongly linked to a reduction in risk of some cancers. Although less is known with respect to exercise and biological markers of aging, physical activity does appear to retard the age‐related decline in the muscle strength and in the bone density.
Reactive Oxygen Intermediates, Molecular Damage, and Aging: Relation to Melatonin
Authors: REITER RUSSELL J. , GUERRERO JUAN M. , GARCIA JOAQUIN J. , ACUÑA‐CASTROVIEJO DARIO 
Published: February 2006

ABSTRACT: Melatonin, the chief secretory product of the pineal gland, is a direct free radical scavenger and indirect antioxidant. In terms of its scavenging activity, melatonin has been shown to quench the hydroxyl radical, superoxide anion radical, singlet oxygen, peroxyl radical, and the peroxynitrite anion. Additionally, melatonin's antioxidant actions probably derive from its stimulatory effect on superoxide dismutase, glutathione peroxidase, glutathione reductase, and glucose‐6‐phosphate dehydrogenase and its inhibitory action on nitric oxide synthase. Finally, melatonin acts to stabilize cell membranes, thereby making them more resistant to oxidative attack. Melatonin is devoid of prooxidant actions.In models of oxidative stress, melatonin has been shown to resist lipid peroxidation induced by paraquat, lipopolysaccharide, ischemia‐reperfusion, l‐cysteine, potassium cyanide, cadmium chloride, glutathione depletion, alloxan, and alcohol ingestion. Likewise, free radical damage to DNA induced by ionizing radiation, the chemical carcinogen safrole, lipopolysaccharide, and kainic acid are inhibited by melatonin. These findings illustrate that melatonin, due to its high lipid solubility and modest aqueous solubility, is able to protect macromolecules in all parts of the cell from oxidative damage. Melatonin also prevents the inhibitory action of ruthenium red at the level of the mitochondria, thereby promoting ATP production. In humans, the total antioxidative capacity of serum is related to melatonin levels. Thus, the reduction in melatonin with age may be a factor in increased oxidative damage in the elderly.