bluuebunny/crossref_metadata_2025_split huggingface dataset:
The major volatile elements of the Earth: Their origin, behavior, and fate
Authors: Javoy M. 
Published: February 2004

Stable isotope constraints impose a heterogeneous accretion of the earth's volatiles: the primary, reduced material, 99.8% of the planet, brought 6% of the hydrogen, 48% of the carbon and 70% of the nitrogen of the Upper Earth (upper mantle, crust, ocean‐atmosphere). A late veneer (1.4 per mil of the bulk Earth's mass), of CI composition, supplied 94% of the hydrogen, 52% of the carbon and 30% of the nitrogen.The present distribution of the major volatiles in the Upper Earth corresponds to a negligible supply from the lower mantle. Measured in units of the superficial reservoirs the upper mantle contains: 0.21 ocean masses of water, ∼10 atmosphere masses of nitrogen, 5.4 crustal carbon masses of carbon.This corresponds to a very significant trapping of carbon and nitrogen by the mantle during the Earth's history, whereas water repartition stayed about unchanged and strongly favoured the superficial reservoir. There is, however, a very significant difference between carbon and nitrogen, the present outgassing and subducting fluxes of carbon being equilibrated both in masses and isotopically, whereas there is still a gross isotopic disequilibrium for nitrogen, the large, isotopically heavy, subducted flux, still outweighing the small, isotopically light, outgassed flux.This is due to the fact that, while carbon and water are essentially incompatible components, nitrogen is a compatible element because of the presence of very stable mantle nitrides (probably osbornite).
Biogeochemical cycling in the Ross Sea: An introduction
Authors: Marra John 
Published: February 2004

Twenty or 30 years ago, interest in the Southern Ocean was largely driven by its exceptional characteristics. The Southern Ocean was such an anomaly, with extremes of productivity (thought to be high), nutrients (also high), temperatures (low), populations of krill and whales, and, of course, the presence of ice. There was also created, perhaps, an allure because of its distance and because it was so unusual, relative to the familiarity of the North Atlantic, for example.It has turned out, not surprisingly, that these exceptional characteristics illustrate the exceptional importance of the Southern Ocean to global ocean phenomena. By virtue of creating water masses the Southern Ocean may play a significant role in the ocean's nutrient distributions. Low temperatures over large areas mean that, potentially, it is a significant sink for dissolved gases such as oxygen and carbon dioxide. It is generally believed that Antarctica (as well as the Arctic) may be more susceptible to climate change than either temperate or tropical ecosystems, because these ecosystems function within a few degrees of the freezing point of water. Altogether, the processes here will tell us much about how the ocean works today and in the distant past.
Early multiplatform results from the International Solar Terrestrial Physics/Global Geospace Science (ISTP/GGS) Program
Authors: Desch M. , Ogilvie K. , Acuna M. , Fairfield D. , Hoffman R. 
Published: February 2004

This issue of the Geophysical Research Letters is the third† to contain a special section devoted to science results from the Global Geospace Science (GGS) Program [Acuna et al, 1995], a key component of the International Solar Terrestrial Physics Program. Designed to provide coverage of key regions of geospace, the GGS suite of spacecraft (WIND, POLAR, and GEOTAIL), along with other currently operational spacecraft, and related groundbased and theoretical support assets are intended to make a significant improvement in our understanding of the flow of energy, mass, and momentum in the solar‐terrestrial environment.With the WIND spacecraft monitoring the upstream interplanetary medium and providing the solar wind input to the magnetosphere, with POLAR measuring plasma input into the magnetosphere and monitoring the Earth's auroral signature, and GEOTAIL observing the geomagnetic tail response, the principal regions of geospace where energy is transported and stored are sampled by an advanced array of instruments. Simultaneous groundbased investigations and theoretical and global modelling round out the synergistic approach to answering key questions concerning how individual parts of this closely‐coupled system work together. The papers in this special section of GRL emphasize this multi‐spacecraft, multi‐discipline approach to solar‐terrestrial observations. The ISTP/GGS program works best when all the elements are working together, and in this issue the value of coordinated, simultaneous observations with multiple platforms is amply demonstrated.
Surface impedance time domain reflectometry for the determination of ice depth
Authors: Garner Stephen J. , Thiel David V. , O'Keefe Steven G. 
Published: February 2004

The analysis of the surface impedance of a horizontally stratified earth is similar to the impedance of a step‐wise discontinuous lossy transmission line. Time Domain Reflectometry (TDR) is commonly used in transmission line assessment to determine the location of faults. There are electrical conditions where TDR can be applied to a two layered subsurface to determine the time of flight of the EM wave and hence the thickness of the top layer. When the upper layer resistivity is sufficiently contrasted over a conductive second layer, then transforming surface impedance data measured across a broad band of frequencies into the time domain allows one to determine the time of flight to the subsurface boundary.If the maximum frequency, frequency step size and number of steps are optimised for the two layers a periodicity appears in the surface impedance profile. It is demonstrated through computer modelling that a layer of ice on rock or sea water gives a return time of flight equal to the separation time of peaks in the time domain surface impedance profile. The technique requires a vertically polarised transmitter which steps up to the high frequency (HF) range. For example an ice layer of 30 to 400 meters thickness requires frequencies up to 5MHz.In this paper, the basic theory for the use of TDR techniques in the interpretation of the surface impedance data is explained, and computer modelling results are presented
Introduction to special section: Synoptic and mesoscale weather systems in the polar regions
Authors: Bromwich David H. 
Published: February 2004

This special section consists primarily of papers contributed to Symposium M‐9 on Synoptic and Mesoscale Weather Systems in the Polar Regions at the XXI General Assembly of the International Union of Geodesy and Geophysics, which was held in Boulder, Colorado, during July 1995. The symposium was convened by John Turner of the British Antarctic Survey and Erik Rasmussen of the University of Copenhagen.High‐latitude meteorology is in a period of rapid transition away from being a generally neglected area of atmospheric science. With the general understanding that the atmospheric and oceanic circulation is to first order driven by the thermal contrast between the equatorial heat source and the polar heat sinks, it no longer seems appropriate to deemphasize the role of the polar regions in climate variability and change. However, the natures of the Arctic and Antarctic are profoundly different. The ice‐covered and land‐locked Arctic Ocean contrasts with the elevated and extensive Antarctic ice sheets that are surrounded by the Southern Ocean. The very different geographic characteristics limit the similarities between these two regions.
Enhancing water quality in hydropower system operations
Authors: Hayes Donald F. , Labadie John W. , Sanders Thomas G. , Brown Jackson K. 
Published: February 2004

The quality of impounded waters often degrades over time because of thermal stratification, sediment oxygen demands, and accumulation of pollutants. Consequently, reservoir releases impact water quality in tailwaters, channels, and other downstream water bodies. Low dissolved oxygen (DO) concentrations in the Cumberland River below Old Hickory dam result from stratification of upstream reservoirs and seasonally low release rates. Operational changes in upstream hydropower reservoirs may be one method to increase DO levels without substantially impacting existing project purposes. A water quality model of the upper Cumberland basin is integrated into an optimal control algorithm to evaluate water quality improvement opportunities through operational modifications. The integrated water quantity/quality model maximizes hydropower revenues, subject to various flow and headwater operational restrictions for satisfying multiple project purposes, as well as maintenance of water quality targets. Optimal daily reservoir release policies are determined for the summer drawdown period which increase DO concentrations under stratification conditions with minimal impact on hydropower production and other project purposes.Appendixes A–D available with entire article on microfiche. Order by mail from AGU, 2000 Florida Ave., N.W., Washington, DC 20009 or by phone at 800‐966‐2481; $2.50. Document W97‐003. Payment must accompany order.
Effects of topical antiglaucoma drugs on apoptosis rates of conjunctival epithelial cells in glaucoma patients
Authors: Dog˘an Aysun Lanal , Orhan Mehmet , Söylemezog˘lu Figen , İrkeç Murat , Bozkurt Banu 
Published: February 2004

Abstract Background: To investigate the effects of topical antiglaucoma drugs on apoptosis rates of conjunctival epithelial cells in vivo. Methods: Specimens were obtained from the bulbar conjunctiva of 30 patients who underwent either cataract or glaucoma surgery. Of these 30 patients, 14 had glaucoma and received topical antiglaucoma drugs. The 16 patients in the control group had neither systemic nor ocular disease except cataract and they did not receive any medications. TUNEL (terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labelling) method was used to show the apoptosis of the conjunctival epithelial cells. Results: Increased apoptosis rates were detected in specimens of patients who were on topical antiglaucoma therapy (mean ± SD 0.208 ± 0.154) when compared with the healthy subjects (mean ± SD 0.083 ± 0.102; P = 0.013). The apoptosis rates did not differ according to type, number or duration of drugs. Conclusions: The apoptosis observed in the conjunctival epithelial cells might be due to the preservative benzalkonium chloride in the antiglaucoma medications because the apoptosis rates did not differ in patients using different types of medications.
Black eye drop bottle tips improve compliance
Authors: Stack Rebecca R , McKellar Malcolm J 
Published: February 2004

Abstract Aim: To determine if dark coloured tips on eye drop bottles facilitate ocular therapy. Methods: Eye drop bottles were modified by placing sterile black tape around the bottle tip. Patients on regular timolol therapy were asked to use bottles with the modified tip for one month. They then completed a questionnaire comparing the black tips with the standard tips on the bottle they normally use. Results: Eighty‐eight per cent of patients found the black tipped bottles easier to use than bottles with the standard tip. Sixty‐eight per cent of patients had fewer occasions on which they needed to instil a second drop and 30% of patients touched their eyelid less when using the modified bottle tips. Conclusion: Black coloured bottle tips aid ocular therapy. They are easier to use, result in less contact with the eye on instillation and patients note a reduction in need for a second or additional drop. This is likely to improve compliance and reduce contamination. A change in manufacturing practise should be encouraged.
Controlled trial of hyperbaric oxygen treatment for alkali corneal burn in the rabbit
Authors: Hirst Lawrence W , Summers Phillip M , Griffiths David , Bancroft Josephine , Lillicrap Gary R 
Published: February 2004

Abstract Purpose: To evaluate the efficacy of hyperbaric oxygen therapy in the treatment of alkali‐induced corneal burns in an animal model. Methods: Twenty‐four rabbits were randomized into a control group (n = 12) and hyperbaric oxygen treatment group (n = 12). After induction of anaesthesia, the alkali burn model was established by application of 1 N sodium hydroxide to one eye of each rabbit. The hyperbaric oxygen treatment group was treated each day for 21 days with hyperbaric oxygen at 2.4 Atmospheres Absolute (ATA) for 1 h. The eyes of the animals were examined daily for 2 weeks and then weekly until the end of the trial. The principal endpoint was that of perforation of the cornea at which time the animals were killed with a lethal dose of either intravenous or intraperitoneal barbiturate and the eyes immediately enucleated and fixed in 10% neutral buffered formalin. All animals in which complete healing took placed were also killed, the eyes removed, fixed and examined histologically. Photographs were taken of the rabbit's eyes at weekly intervals and the area of vascularization and epithelial defects in the hyperbaric and control groups were compared. Results: Equal numbers (seven) of the control and hyperbaric oxygen treated groups had perforated corneas and there was no statistical difference in the mean time to perforation (control 30.1 days; treated 30 days). There was also no statistical difference between the two groups with respect to epithelial defect size. Conclusion: Treatment with hyperbaric oxygen for 1 h daily for 21 days had no beneficial effect on alkali‐induced corneal burns.
Activation of ERK1/2 after neonatal rat cerebral hypoxia–ischaemia
Authors: Wang Xiaoyang , Zhu Changlian , Qiu Lin , Hagberg Henrik , Sandberg Mats , Blomgren Klas 
Published: February 2004

AbstractActivation of extracellular signal‐related kinases (ERK1/2), also known as p42/44 mitogen‐activated protein kinase (MAPK), is considered important for neuronal survival, cell proliferation and apoptosis. In the present study, activation (phosphorylation) of ERK1/2 (P‐ERK) was investigated in brains of 7‐day‐oldrats after hypoxia‐ischaemia (HI). In damaged areas, P‐ERK‐positive neurons appeared immediately after HI and the staining remained for at least 8 h. At later time points, 24 and 72 h post‐HI, P‐ERK‐positive neurons were found in the core of the infarct and in the border zone to undamaged tissue. These cells also showed signs of DNA damage and calpain‐induced fodrin breakdown, indicative of injury. At 72 h post‐HI, P‐ERK was also observed in microglia in the border zone to the damaged area and in astrocytes and oligodendrocytes in white matter of both hemispheres. P‐ERK was strongly expressed in the subventricular zone in both hemispheres after HI at most time points, although the staining in the ipsilateral (damaged hemisphere) was stronger than in the contralateral (non‐damaged hemisphere). In summary, ERK1/2 activation occurred early in neurons after HI in the neonatal brain, and mainly in cells displaying signs of damage.
Striatal neurones show sustained recovery from severe hypoglycaemic insult
Authors: McDermott C. J. , Bradley K. N. , McCarron J. G. , Palmer A. M. , Morris B. J. 
Published: February 2004

AbstractGlucose deprivation provides a reliable model to investigate cellular responses to metabolic dysfunction, and is reportedly associated with permanent cell death in many paradigms. Consistent with previous studies, primary cultures of rat striatal neurones exposed to 24‐h hypoglycaemia showed dramatically decreased sodium 2,3‐bis(2‐methoxy‐4‐nitro‐5‐sulfophenyl)‐2H‐tetrazolium‐5‐carboxanilide (XTT) metabolism (used as a marker of cell viability) and increased TUNEL staining, suggesting widespread DNA damage typical of apoptotic cell death. Remarkably, restoration of normal glucose levels initiated a sustained recovery in XTT staining, along with a concomitant decrease in TUNEL staining, even after 24 h of hypoglycaemia, suggesting recovery of damaged neurones and repair of nicked DNA. No alterations in the levels of four DNA repair proteins could be detected during hypoglycaemia or recovery. A reduction in intracellular calcium concentration was seen in recovered cells. These data suggest that striatal cells do not die after extended periods of glucose deprivation, but survive in a form of suspended animation, with sufficient energy to maintain membrane potential.
Amyloid‐beta increases acetylcholinesterase expression in neuroblastoma cells by reducing enzyme degradation
Authors: Hu William , Gray Noah W. , Brimijoin Stephen 
Published: February 2004

AbstractAmyloid‐beta (Aβ) is the principal protein constituent of ‘senile plaques’ and is a suspected mediator in Alzheimer's disease (AD). Senile plaques also contain acetylcholinesterase (AChE; EC 3.1.1.7), which may have a role in promoting Αβ‐toxicity. We have found that Αβ can affect AChE expression in a neuron‐like line, the N1E.115 neuroblastoma cell. When 1 µmΑβ 1–42 or 25–35 was added for 24 h to differentiating N1E.115 in culture, AChE activity increased 30–40% in adherent cells, and 100% or more in nonadherent cells. The changes in both tetrameric (G4) and monomeric (G1) AChE forms were comparable. Turnover studies indicated that the elevation of AChE activity reflected slowed AChE degradation rather than accelerated synthesis. With a similar time course, Αβ also increased the quantity of muscarinic receptors on the plasma membrane. Immunocytochemistry for a lysosomal membrane protein (LAMP‐1) indicated no change in abundance or localization of lysosomes in treated cells. But decreased labeling by pH‐sensitive fluorescent dye pointed to an impairment of lysosomal acidification. We consider that the alteration of AChE expression after Αβ‐exposure could reflect lysosomal dysfunction, and might itself enhance Αβ‐toxicity.
Interaction of 14‐3‐3 with Bid during seizure‐induced neuronal death
Authors: Shinoda Sachiko , Schindler Clara K. , Quan‐Lan Jing , Saugstad Julie A. , Taki Waro , Simon Roger P. , Henshall David C. 
Published: February 2004

AbstractSeizure‐induced neuronal death may involve coordinated intracellular trafficking and protein–protein interactions of members of the Bcl‐2 family. The 14‐3‐3 proteins are known to sequester certain pro‐apoptotic members of this family. BH3‐interacting domain death agonist (Bid) may contribute to seizure‐induced neuronal death, although regulation by 14‐3‐3 has not been reported. In this study we examined whether 14‐3‐3 proteins interact with Bid during seizure‐induced neuronal death. Brief seizures were evoked in rats by intraamygdala microinjection of kainic acid to elicit unilateral hippocampal CA3 neuronal death. Coimmunoprecipitation analysis demonstrated that although Bcl‐2‐associated death promoter (Bad) constitutively bound 14‐3‐3, there was no interaction between Bid and 14‐3‐3 in control brain. Seizures triggered Bid cleavage and a commensurate increase in binding of Bid to 14‐3‐3 within injured hippocampus. Casein kinases I and II, which can inactivate Bid by phosphoserine/threonine modification, did not coimmunoprecipitate with Bid. The largely uninjured contralateral hippocampus did not exhibit Bid cleavage or binding of 14‐3‐3 to Bid. In vitro experiments confirmed that 14‐3‐3β is capable of binding truncated Bid, likely in the absence of phosphoserine/threonine modification. These data suggest 14‐3‐3 proteins may target active as well as inactive conformations of pro‐apoptotic Bcl‐2 death agonists, highlighting novel targets for intervention in seizure‐induced neuronal death.
From ethnic group toward the modern nation: the Czech case
Authors: Hroch Miroslav 
Published: February 2004

AbstractHistorians usually try to understand and interpret the reasons for the successful result of national movements. Less attractive seems to be the question, why the early ‘nationalists’ took the decision to persuade the members of their ethnie to accept a new national identity, i.e., why did Phase B start? The author of this article formulated many years ago the hypothesis that this decision had to do with the identity crisis caused by great reforms and changes which put in question the old system of values and legitimacy, and eroded old pre‐modern ties in patriarchal or late ‘feudal’ societies. The article tries to check this hypothesis analyzing the turn towards Phase B in the case of Czech intellectuals (in Bohemia) at the end of the eighteenth and first decade of the nineteenth centuries, in the time of radical enlightened reforms and of the wars against the French Revolution. Loosening their old ties and traditional values, these intellectuals tried to find a new identity with their nation‐to‐be. The author argues that this decision was not a voluntarist mood or ‘nationalist’ plague but that it had serious social motivation. The same can be said about the turn of the incipient Czech national movement towards language and literature.
Eating behaviors of elderly persons with hyperlipidemia in urban Chiang Mai
Authors: Aree Patcharaporn , Tanphaichitr Vichai , Suttharangsri Wandee , Kavanagh Kathryn 
Published: February 2004

AbstractThe objective of the present ethnographic study was to describe the eating behaviors of elderly persons with hyperlipidemia. Twenty‐one elderly subjects with hyperlipidemia and their relatives volunteered to be included in the study. Focus group and in‐depth interviews with participant observations were used for data collection. Each transcript from interviews and observations were analyzed using content analysis. Subjects were asked to validate findings and ethical considerations were maintained throughout the study. When discussing the meaning of food, three themes emerged: (i) substances make people strong or healthy; (ii) food is like medicine and; (iii) food causes illness. Most subjects had learned about food and nutrition from their parents or relatives and from school. Regarding food procurement, most bought food such as fish or other seafood, meat and eggs from the fresh markets nearby almost daily. All subjects cooked their own traditional northern Thai food, such as Hung‐le (northern curry) and preferred seasoning such as fish sauce, pepper and herbs. They ate when they were hungry or after they had finished working. The present study reflected that northern Thai culture strongly influences the participants’ eating behaviors.
Predictors of nurses’ intent to stay at work in a university health center
Authors: Sourdif Jacynthe 
Published: February 2004

AbstractThe purpose of the present study was to evaluate nurses’ intent to stay at work and to determine the associations between intent to stay and various predictors. A sample of 108 nurses at a single tertiary care hospital filled in a questionnaire on intent to stay, satisfaction at work, satisfaction with administration, organizational commitment and work group cohesion. The results showed that the majority of nurses are planning to stay in their current job. Satisfaction at work and satisfaction with administration are the best predictors of intent to stay and explained 25.5% of intent to stay variance. It is possible that developing strategies based on the predictors of intent to stay at work could improve that intent. Healthcare organizations could consider this with the objective of increasing nurses’ intent to stay at work and, consequently, retention.