bluuebunny/crossref_metadata_2025 huggingface dataset:
Dispersal and germination syndromes of tree seeds in a monsoonal forest in northern India
Authors: Thapliyal R.C. , Phartyal S.S.
Published: March 2005

This paper describes the dispersal–germination characteristics of seeds of 77 native tree species in a seasonal monsoon forest in Uttaranchal state, northern India. Results indicate that 50% of the species dispersed in the hot, dry summer months, 18% during the rainy season, 23% during the cold season and the remainder in late spring. Germination tests on fresh and laboratory-stored seeds revealed a relationship between morphological features of the fruit and both germination percentage and mean germination time (MGT). Highest mean germination (50%) was for dry-dehiscent fruits with winged wind-dispersed seeds, followed by dry-dehiscent fruits with non-winged seeds (38%) and seeds of dry-indehiscent fruits (37%). Lowest germination (29%) was for seeds from fleshy or pulpy fruits. MGT followed the reverse course. Germination data for seeds stored dry in the laboratory during one seeding cycle indicated six patterns of seed germination: (1) average germination percentage of fresh seeds lower than that of stored seeds, indicating an after-ripening requirement; (2) initial high germination percentage followed by low values, indicating a steep to moderate decline in viability following harvest; (3) no germination after 1 or 2 months of seed storage, due to complete loss of viability, indicating short seed longevity; (4) fresh seed germination in some species equalled the average germination value of stored seeds, indicating constant germination for one whole seeding cycle; (5) germination of both fresh and stored seeds remained consistently low throughout the season, indicating a requirement for some kind of pre-treatment or having poor quality of seeds; (6) initial high germination followed by decline and again increase, showing a seasonal rhythm of germination.
Salinity tolerance during germination of seashore halophytes and salt-tolerant grass cultivars
Authors: Hanslin Hans Martin , Eggen Trine
Published: March 2005

Direct sowing is the simplest method of plant establishment for restoration and remediation purposes, but relatively few plants can establish under high salinity conditions. In this study, the ability of different seashore plants and grass cultivars to germinate in different dilutions of seawater (0–400 mM NaCl) was tested. Highest germination was found in distilled water or seawater dilutions up to 100 mM NaCl. When seawater concentrations were increased from 100 to 200 mM NaCl, a strong decline in germination percentage and rate was observed in less salt-tolerant species, such as Matricaria maritima and Achillea millefolium. The more salt-tolerant species, Plantago maritima, Juncus gerardii, Artemisia vulgaris, Agrostis spp. and Rumex spp., had a threshold salinity, where germination was significantly decreased in seawater dilutions between 200 and 400 mM NaCl. Even among the salt-tolerant species, only two, Agrostis stolonifera and Artemisia vulgaris, germinated at 400 mM. Variation in salinity response was observed among populations of Artemisia vulgaris and among cultivars of Festuca spp. Increasing salinity to 200 mM NaCl delayed germination in most species. Ungerminated seeds of most salinity-tolerant species were still viable after 21 d at the highest salinity (400 mM), and showed a rapid and high germination when transferred to distilled water. These species would be able to survive high salinity and germinate when the salinity of the sediments decreases through dilution or leaching of salts. The experiment revealed species and cultivars that will be of interest in further testing for restoration and remediation in saline habitats.
‘WARS ON TERROR’ AND VICARIOUS HEGEMONS: THE UK, INTERNATIONAL LAW, AND THE NORTHERN IRELAND CONFLICT
Authors: Campbell Colm
Published: March 2005

The hegemonic position of the United States, and its implication for international law, are rapidly emerging as sites of intense scholarly interest.1It is a truism that the fall of the Berlin wall has been followed by a period of unprecedented American predominance in the military, economic, and political spheres. Replacing the bi-polar certainties of the Cold War is a world in flux, dominated, to a significant extent, by one remaining superpower, or, in the words of the former French Foreign Minister, Hubert Vedrine, by a ‘hyperpower’.2Some though, have emphasised the continuing importance of other loci of (lesser) power in a ‘uni-multipolar’ world.3That this domination posed critical questions for international law was obvious well before the 9/11 atrocities, as the debate over NATO's use of force in Kosovo illustrated. Since the invasions of Afghanistan and Iraq, and with the global ‘war on terror’ reaching into ever-increasing spheres, the debate has intensified significantly.
MARGINS OF APPRECIATION: CULTURAL RELATIVITY AND THE EUROPEAN COURT OF HUMAN RIGHTS IN THE POST-COLD WAR ERA
Authors: Sweeney James A
Published: March 2005

The number of states participating in the Council of Europe's system for the protection of human rights has grown rapidly over recent years. Established in 1949 with an initial membership of 10 states, the Council has now grown to a membership of 46,2dwarfing the EU in its geographical reach. The most significant period of enlargement has been since the end of the Cold War as the formerly Communist states from central and eastern Europe flocked to the Council of Europe seeking assistance with the process of democratisation. The Council's most prominent human rights treaty, the European Convention on Human Rights, has entered into force for all but one of the 46 member states.3This paper questions whether the European Court of Human Rights' recognition of a national ‘margin of appreciation’ has allowed these new Contracting Parties too much leeway in the way they choose to protect, or more specifically, to limit, the exercise of human rights.
MERCOSUR AND REGIONAL INTEGRATION IN SOUTH AMERICA
Authors: Vervaele John AE
Published: March 2005

In the period between 1980 and 1995, both Europe and the US made huge investments in Latin America. The process of democratization in Latin America, especially in the countries marked by a tradition of military dictatorship, has reinforced the belief in political and economic stability. The economy has displayed considerable growth and, partly stimulated by the IMF and the World Bank, several countries are embarking on privatization on a grand scale.2 Political and economic cooperation between the countries is taking the place of political and military rivalry. The time is ripe for a new attempt at integration on this continent. The overtures between Argentina and Brazil led to the establishment of Mercosur. Its economic (Mercosur is the fourth largest trade bloc in the world after the US, the EU, and Japan) and political importance have been recognized, especially by the EU. As early as 1996,3 an Interinstitutional Cooperation Agreement was concluded, an interregional framework agreement for cooperation between the EU Member States and Mercosur States parties.4 Since then, the EU-Mercosur Bi-regional Negotiations Committee (BNC)5 has already had ten meetings at which topics such as the free movement of goods, public procurement, investments, services, e-commerce, and conflict resolution were discussed. The US has never appreciated the attempts at integration in Latin America and has always striven to conclude separate free trade agreements with each individual country. The recent free trade agreement with Chile is a clear example.6
The relative role of winter and spring conditions: linking climate and landscape-scale plant phenology to alpine reindeer body mass
Authors: Pettorelli Nathalie , Weladji Robert B , Holand Øystein , Mysterud Atle , Breie Halgrim , Stenseth Nils Chr
Published: March 2005

The relative importance of winter harshness and early summer foraging conditions are of prime interest when assessing the effect of global warming on artic and mountainous ecosystems. We explored how climate and vegetation onset (satellite-derived Normalized Difference Vegetation Index data) determined individual performance in three reindeer populations (data on 27 814 calves sampled over 11 years). Snow conditions, spring temperatures and topography were the main determinants of the onset of the vegetation. An earlier onset positively affected the body mass of calves born the following autumn, while there was no significant direct negative impact of the previous winter. This study underlines the major impact of winter and spring climatic conditions, determining the spring and summer food availability, and the subsequent growth of calves among alpine herbivores.
An Explanation of Shortening Heat Generation and Mechanical Performance Enhancement during Muscle Stretch
Authors: Eremia Dan
Published: March 2005

Titin is an extraordinary long multidomain protein spanning half of the sarcomeric unit. One end of the titin filament is known to emerge from the Z-line, but the precise localization of the other end is still a matter of debate. Assuming that titin filaments connect the Z-line to the tips of thin filaments in the opposite half of the sarcomere, the behavior of an actively contracting muscle during mechanical stretch, as well as the mechanism of muscle shortening heat generation, can be easily explained if one considers that titin filaments are involved not only in the passive elasticity of the muscle but also in the force and heat generation during contraction.
Surface Level Ozone and its Adverse Effects on Crops and Forests: A Need for an Interdisciplinary Understanding
Authors: Krupa Sagar V.
Published: March 2005

Surface level ozone (O3) is clearly a global scale problem with regard to its adverse effects on crops, forests and native, terrestrial plant ecosystems. Photochemists and meteorologists are continuing to define the chemistry and physics of the prevalence of O3at the ground level. Similarly, plant scientists in the U.S. and Europe have examined the effects of O3on crops and tree seedlings or saplings through large-scale studies. Examples include the U.S. National Crop Loss Assessment Network (NCLAN), the U.S. EPA’s (Environmental Protection Agency’s) San Bernardino National Forest Photochemical Oxidant Study, European Open-top Chambers Programme (EOTCP), and several ongoing EU (European Union) projects. In addition, there have been studies on mature tree responses through field measurements and by simulation modeling.
Class I Areas at Risk: Event-Based Nitrogen Deposition to a High-Elevation, Western Site
Authors: Williams Mark W. , Manthorne Dave
Published: March 2005

Between June 1, 2000 and September 30, 2000, 32 precipitation events were sampled near Telluride, CO at an elevation of 3200 m. The wet deposition site was operated following protocols of the Atmospheric Integrated Research Monitoring Network (AIRMoN), a network of the National Atmospheric Deposition Network (NADP). Inorganic nitrogen deposition at the Telluride site of 1.41 kg ha-1during the study period was 25 to 50% higher than nearby NADP sites. In turn, nitrogen deposition at these NADP sites was similar to high-elevation sites in and near the Colorado Front Range that have been shown to be impacted by atmospheric deposition of inorganic nitrogen in wetfall. Power plant emissions are a likely source of a major portion of this elevated inorganic nitrogen in wetfall to the San Juan Mountains. Principal component analysis (PCA) shows that solutes formed by gases that are emitted from power plants were clustered tightly together, including nitrate, ammonium, sulfate, and chloride. Trajectory analysis, including both backward and forward trajectories, shows that the air masses that contributed to the precipitation events with high amounts of nitrogen deposition at the Telluride site passed directly over or near power plants. Our results suggest that Class I Wilderness Areas in and near the San Juan Mountains are at risk to ecosystem impairment at present rates of atmospheric deposition of inorganic nitrogen in wetfall. Deployment of proposed power plants to this area will likely increase the risk of degradation of resource values in nearby Class I areas. While these data were collected over a short time span, they indicate that establishment of an official AIRMoN site in the southwestern U.S. may be warranted.
Input-Output Budget of Nitrogen and the Effect of Experimentally Changed Deposition in the Forest Ecosystems in Central Japan
Authors: Shindo Junko , Fumoto Tamon , Oura Noriko , Toda Hideshige , Kawashima Hiroyuki
Published: March 2005

To evaluate the current nitrogen (N) status in Japanese forests, field measurements of rainfall, throughfall, litter layer percolation, and soil solution percolation were conducted in a red pine stand (Kannondai) and a deciduous stand (Yasato) located in central Japan. N input via throughfall was 31 and 14 kg ha–1year–1and output below rooting zone was 9.6 and 5.5 kg ha1year–1in Kannondai and in Yasato, respectively. Two thirds of input N were retained in plant-soil systems. Manipulation of N input was carried out. Ionic constituents were removed from throughfall with ion exchange resin at removal sites and ammonium nitrate containing twice the N of the throughfall was applied at N addition sites periodically. SO42–output below 20-cm soil layer changed depending on the input, while NO3–output was regulated mainly by the internal cycle and effect of manipulation was undetected. These Japanese stands were generally considered to have a larger capacity to assimilate N than NITREX sites in Europe. However, N output fluxes had large spatial variability and some sites in Kannondai showed high N leaching below rooting zone almost balanced with the input via throughfall.
An Innovative Approach for Locating and Evaluating Subsurface Pathways for Nitrogen Loss
Authors: Walthall C.L. , Gish T.J. , Daughtry C.S.T. , Dulaney W.P. , Kung K.-J.S. , McCarty G. , Timlin D. , Angier J. T. , Buss P. , Houser P. R.
Published: March 2005

Fundamental watershed-scale processes governing chemical flux to neighboring ecosystems are so poorly understood that effective strategies for mitigating chemical contamination cannot be formulated. Characterization of evapotranspiration, surface runoff, plant uptake, subsurface preferential flow, behavior of the chemicals in neighboring ecosystems, and an understanding of how crop management practices influence these processes are needed. Adequate characterization of subsurface flow has been especially difficult because conventional sampling methods are ineffective for measuring preferential flow of water and solutes. A sampling strategy based on ground-penetrating radar (GPR) mapping of subsurface structures coupled with near real-time soil moisture data, surface topography, remotely sensed imagery, and a geographic information system (GIS) appears to offer a means of accurately identifying subsurface preferential flow pathways. Four small adjacent watersheds draining into a riparian wetland and first-order stream at the USDA-ARS Beltsville Agricultural Research Center, Beltsville, MD are being studied with this protocol. The spatial location of some preferential flow pathways for chemicals exiting these agricultural watersheds to the neighboring ecosystems have been identified. Confirmation of the pathways is via examination of patterns in yield monitor data and remote sensing imagery.
Founding Editorial – Forensics and TheScientificWorld
Authors: Rowe Walter
Published: March 2005

At the beginning of a new millennium it seems a good idea to stop for a moment and take stock of the current state of forensic science. As a field of scientific research and scientific application, forensic science is a little more than a century old. Forensic science may be said to have begun in 1887 with the simultaneous publication of A. Conan Doyle’s A Study in Scarlet and Hans Gross’s Handbuch für Untersuchungsrichter. Conan Doyle’s novel introduced to the world the character of Sherlock Holmes, whose literary career would popularize the use of physical evidence in criminal investigations. Gross’s manual for examining magistrates suggests ways in which the expertise of chemists, biologists, geologists, and other natural scientists could contribute to investigations. Gross’s book was translated into a number of languages and went through various updated editions during the course of the century. The intervening century saw the development and application of fingerprinting, firearm and tool mark identification, forensic chemistry, forensic biology, forensic toxicology, forensic odontology, forensic pathology, and forensic engineering. Increasingly, the judicial systems of the industrial nations of the world have come to rely upon the expertise of scientists in a variety of disciplines. In most advanced countries, virtually all criminal prosecutions now involve the presentation of scientific testimony. This has had the beneficial effect of diminishing the reliance of courts on eyewitness testimony and defendant confessions.
N-Losses and Energy Use in a Scenario for Conversion to Organic Farming
Authors: Dalgaard Tommy , Kjeldsen Chris , Hutchings Nicholas J. , Hansen Jorgen F.
Published: March 2005

The aims of organic farming include the recycling of nutrients and organic matter and the minimisa-tion of the environmental impact of agriculture. Reduced nitrogen (N)-losses and energy (E)-use are therefore fundamental objectives of conversion to organic farming. However, the case is not straightforward, and different scenarios for conversion to organic farming might lead to reduced or increased N-losses and E-use. This paper presents a scenario tool that uses a Geographical Information System in association with models for crop rotations, fertilisation practices, N-losses, and E-uses. The scenario tool has been developed within the multidisciplinary research project Land Use and Landscape Development Illustrated with Scenarios (ARLAS). A pilot scenario was carried out, where predicted changes in N-losses and E-uses following conversion to organic farming in areas with special interests in clean groundwater were compared. The N-surplus and E-use were on average reduced by 10 and 54%, respectively. However, these reductions following the predicted changes in crop rotations, livestock densities, and fertilisation practices were not large enough to ensure a statistically significant reduction at the 95% level. We therefore recommend further research in how conversion to organic farming or other changes in the agricultural practice might help to reduce N-surpluses and E-uses. In that context, the presented scenario tool would be useful.
Ecosystem Processes and Nitrogen Export in Northern U.S. Watersheds
Authors: Stottlemyer Robert
Published: March 2005

There is much interest in the relationship of atmospheric nitrogen (N) inputs to ecosystem outputs as an indicator of possible “nitrogen saturation” by human activity. Longer-term, ecosystem-level mass balance studies suggest that the relationship is not clear and that other ecosystem processes may dominate variation in N outputs. We have been studying small, forested watershed ecosystems in five northern watersheds for periods up to 35 years. Here I summarize the research on ecosystem processes and the N budget. During the past 2 decades, average wet-precipitation N inputs ranged from about 0.1 to 6 kg N ha–1year–1among sites. In general, sites with the lowest N inputs had the highest output-to-input ratios. In the Alaska watersheds, streamwater N output exceeded inputs by 70 to 250%. The ratio of mean monthly headwater nitrate (NO3–) concentration to precipitation NO3–concentration declined with increased precipitation concentration. A series of ecosystem processes have been studied and related to N outputs. The most important appear to be seasonal change in hydrologic flowpath, soil freezing, seasonal forest-floor inorganic N pools resulting from over-winter mineralization beneath the snowpack, spatial variation in watershed forest-floor inorganic N pools, the degree to which snowmelt percolates soils, and gross soil N mineralization rates.
Assessment of Nitrogen Ceilings for Dutch Agricultural Soils to Avoid Adverse Environmental Impacts
Authors: de Vries Wim , Kros Hans , Oenema Oene , Erisman Jan Willem
Published: March 2005

In the Netherlands, high traffic density and intensive animal husbandry have led to high emissions of reactive nitrogen (N) into the environment. This leads to a series of environmental impacts, including: (1) nitrate (NO3) contamination of drinking water, (2) eutrophication of freshwater lakes, (3) acidification and biodiversity impacts on terrestrial ecosystems, (4) ozone and particle formation affecting human health, and (5) global climate change induced by emissions of N2O. Measures to control reactive N emissions were, up to now, directed towards those different environmental themes. Here we summarize the results of a study to analyse the agricultural N problem in the Netherlands in an integrated way, which means that all relevant aspects are taken into account simultaneously. A simple N balance model was developed, representing all crucial processes in the N chain, to calculate acceptable N inputs to the farm (so-called N ceiling) and to the soil surface (application in the field) by feed concentrates, organic manure, fertiliser, deposition, and N fixation. The N ceilings were calculated on the basis of critical limits for NO3concentrations in groundwater, N concentrations in surface water, and ammonia (NH3) emission targets related to the protection of biodiversity of natural areas. Results show that in most parts of the Netherlands, except the western and the northern part, the N ceilings are limited by NH3emissions, which are derived from critical N loads for nature areas, rather than limits for both ground- and surface water. On the national scale, the N ceiling ranges between 372 and 858 kton year–1depending on the choice of critical limits. The current N import is 848 kton year–1. A decrease of nearly 60% is needed to reach the ceilings that are necessary to protect the environment against all adverse impacts of N pollution from agriculture.
An Internet-Based Simulation Model for Nitrogen Management in Agricultural Settings
Authors: Shaffer M.J. , Newton B.J. , Gross C.M.
Published: March 2005

Complex chemical, physical, and biological processes mediate nitrogen (N) transformations and movement during agricultural production, making the optimization of fertilizer use and environmental protection exceedingly difficult. Various computer models have been developed to simulate the site-specific fate and transport of N resulting from different crop production scenarios, but these models are very complex and difficult to use for most farmers, consultants, and conservationists. In an effort to facilitate access and simplify the use of sophisticated models, the U.S. Department of Agriculture (USDA) has developed an Internet-based nitrogen analysis tool. Based on the Nitrate Leaching and Economic Analysis Package (NLEAP), the Web site allows a user to conduct multiyear N simulation modeling specific to a crop field. Servers handle much of the required data assembly and formatting, thus sparing the user�s resources. Model runs are executed on the servers and the results are transmitted to the user. This new tool is presented along with early implementation results.
Symbiotic Performance of Herbaceous Legumes in Tropical Cover Cropping Systems
Authors: Ibewiro Basil , Onuh Martin , Sanginga Nteranya , Vanlauwe Bernard , Merckx Roel
Published: March 2005

Increasing use of herbaceous legumes such as mucuna (Mucuna pruriens var. utilis [Wright] Bruck) and lablab (Lablab purpureus [L.] Sweet) in the derived savannas of West Africa can be attributed to their potential to fix atmospheric nitrogen (N2). The effects of management practices on N2fixation in mucuna and lablab were examined using 15N isotope dilution technique. Dry matter yield of both legumes at 12 weeks was two to five times more in in situ mulch (IM) than live mulch (LM) systems. Land Equivalent Ratios, however, showed 8 to 30% more efficient utilization of resources required for biomass production under LM than IM systems. Live mulching reduced nodule numbers in the legumes by one third compared to values in the IM systems. Similarly, nodule mass was reduced by 34 to 58% under LM compared to the IM systems. The proportion of fixed N2in the legumes was 18% higher in LM than IM systems. Except for inoculated mucuna, the amounts of N fixed by both legumes were greater in IM than LM systems. Rhizobia inoculation of the legumes did not significantly increase N2fixation compared to uninoculated plots. Application of N fertilizer reduced N2fixed in the legumes by 36 to 51% compared to inoculated or uninoculated systems. The implications of cover cropping, N fertilization, and rhizobia inoculation on N contributions of legumes into tropical low-input systems were discussed.
Quantification, Sources, and Control of Ammonia Emissions in the Czech Republic
Authors: Skybova Marie
Published: March 2005

The exact quantification of ammonia (NH3) emissions is the basic presumption for the fulfilment of obligations set by the CLRTAP (Convention on Long Range Transboundary Air Pollution) Protocol which was signed by the Czech Republic in 1999. Most NH3emissions in the Czech Republic are produced during the breeding of cattle, pigs, and poultry; therefore, determinating emission factors for these kinds of animals by studying their total number, type of breeding, and subsequent disposal of manure is the solution to the problem of NH3emissions quantification. This paper summarizes the results of 4 years of research in this area, determining the emission factors and ways of decreasing emissions from the breeding of cattle, pigs, and poultry.
Soil N Fluxes in Three Contrasting Dry Tropical Forests
Authors: Tokuchi Naoko , Nakanishi Asami , Wachirinrat Chongrak , Takeda Hiroshi
Published: March 2005

A comparative study of N fluxes in soil among a dry dipterocarp forest (DDF), a dry evergreen forest (DEF), and a hill evergreen forest (HEF) in Thailand was done. N fluxes in soil were estimated using an ion exchange resin core method and a buried bag method. Soil C and N pools were 38 C Mg/ha/30 cm and 2.5 N Mg/ha/30 cm in DDF, 82 C Mg/ha/30 cm and 6.2 N Mg/ha/30 cm in DEF, and 167 C Mg/ha/30 cm and 9.3 N Mg/ha/30 cm in HEF. Low C concentration in the DDF and DEF sites was compensated by high fine soil content. In the highly weathered tropical soil, fine soil content seemed to be important for C accumulation. Temporal and vertical fluctuations of N fluxes were different among the sites. The highest N flux was exhibited at the onset of the wet season in DDF, whereas inorganic N production and estimated uptake of N were relatively stable during the wet season in DEF and HEF. It is suggested that N cycling in soil becomes stable in dry tropical forests to intermediate in temperate forests. N deposition may result in large changes of N cycling in the DDF and DEF due to low accumulations of C and N.
Alternate Nitrogen Amendments for Organic Fertilizers
Authors: Sridhar M.K.C. , Adeoye G.O. , AdeOluwa O.O.
Published: March 2005

The use of compost or manure in agriculture as an organic source of nutrients is common in many tropical, developing countries like Nigeria. One of the drawbacks of such materials is their low nitrogen (N) content (=1% N). Farmers commonly use chemical N fertilizers such as urea, calcium ammonium nitrate (CAN), and NPK formulations to obtain better crop growth and yield. These chemical supplements may have a negative impact on the environment through nitrate leaching into water, leading to eutrophication of surface waters that can affect public health. Gliricidia sepium, a fast-growing, tropical, perennial hedge plant was tested as a source of N in organo-mineral fertilizer formulations. Average nutrient content of Gliricidia is 3.8% N, 0.32% P, 1.8% K, 0.8% Ca, and 0.2% Mg. Using a sand culture and Amaranthus caudatus as a test crop, it was shown that amending commercial composts with 30% Gliricidia prunings would benefit many small-scale farmers and control environmental pollution.
Extracellular and Intracellular Regulation of Calcium Homeostasis
Authors: Bronner Felix
Published: March 2005

An organism with an internal skeleton must accumulate calcium while maintaining body fluids at a well-regulated, constant calcium concentration. Neither calcium absorption nor excretion plays a significant regulatory role. Instead, isoionic calcium uptake and release by bone surfaces causes plasma calcium to be well regulated. Very rapid shape changes of osteoblasts and osteoclasts, in response to hormonal signals, modulate the available bone surfaces so that plasma calcium can increase when more low-affinity bone calcium binding sites are made available and can decrease when more high-affinity binding sites are exposed. The intracellular free calcium concentration of body cells is also regulated, but because cells are bathed by fluids with vastly higher calcium concentration, their major regulatory mechanism is severe entry restriction. All cells have a calcium-sensing receptor that modulates cell function via its response to extracellular calcium. In duodenal cells, the apical calcium entry structure functions as both transporter and a vitamin D–responsive channel. The channel upregulates calcium entry, with intracellular transport mediated by the mobile, vitamin D–dependent buffer, calbindin D9K, which binds and transports more than 90% of the transcellular calcium flux. Fixed intracellular calcium binding sites can, like the body's skeleton, take up and release calcium that has entered the cell, but the principal regulatory tool of the cell is restricted entry.
Stem Cell Quandary Quashes Research, Smithsonian Secretary Backs Down from CRC Closure - and Welcome Back to Star Wars
Authors: Haley Shauna M.
Published: March 2005

Nature leads this week with a story about how questions surrounding stem cell research have thrown a funding agency and the German government into the boxing ring. The contested overhaul of the U.S. Smithsonian Institution tops the news this week in Science.
Founding Editorial — Atmospheric Systems and TheScientificWorld
Authors: Brimblecombe Peter , Watson John G.
Published: March 2005

There is a satisfying logic to the Greek choice of air, water, and earth as elements. Today we see this logic reflected in the way that that global science is subdivided into the categories of air, land, and water. Thus, the relevance of a science of global issues is not merely of academic interest. The tide of environmental concern, a vision of limits to growth, and a desire for sustainability have fostered an unprecedented interest in global sciences.
Alternative Attractors of Shallow Lakes
Authors: Scheffer Marten
Published: March 2005

Ponds and shallow lakes can be very clear with abundant submerged plants, or very turbid due to a high concentration of phytoplankton and suspended sediment particles. These strongly contrasting ecosystem states have been found to represent alternative attractors with distinct stabilizing feedback mechanisms. In the turbid state, the development of submerged vegetation is prevented by low underwater light levels. The unprotected sediment frequently is resuspended by wave action and by fish searching for food causing a further decrease of transparency. Since there are no plants that could serve as refuges, zooplankton is grazed down by fish to densities insufficient to control algal blooms. In contrast, the clear state in eutrophic shallow lakes is dominated by aquatic macrophytes. The submerged macrophytes prevent sediment resuspension, take up nutrients from the water, and provide a refuge for zooplankton against fish predation. These processes buffer the impacts of increased nutrient loads until they become too high. Consequently, the response of shallow lakes to eutrophication tends to be catastrophic rather than smooth, and various lakes switch back and forth abruptly between a clear and a turbid state repeatedly without obvious external forcing. Importantly, a switch from a turbid to a stable clear state often can be invoked by means of biomanipulation in the form of a temporary reduction of the fish stock.
Reactions among Indoor Pollutants
Authors: Weschler Charles J.
Published: March 2005

This paper reviews recent studies in the field of “indoor chemistry” — reactions among indoor pollutants. Advances have occurred in a number of areas. A mouse bioassay procedure has shown that ozone/terpene reactions produce products that are more irritating than their precursors, although the agents responsible for the deleterious effects remain to be determined. Indoor ozone/terpene reactions have been demonstrated to produce hydroxyl radicals, hydrogen peroxide, sub-micron particles, and ultrafine particles. New analytical techniques such as LC/MS and thermal desorption mass spectrometry have greatly improved our knowledge of the condensed-phase species associated with such particles. Indeed, the latter approach has identified a number of short-lived or thermally labile species, including organic hydroperoxides, peroxy-hemiacetals, and secondary ozonides, which would be missed by more conventional techniques. Investigators are making inroads into the poorly understood area of indoor heterogeneous chemistry. Systems studied include ozone/HVAC components, ozone/paint, and ozone/carpets. Another heterogeneous process that has been further examined is the indoor formation of nitrous acid through NO2/surface chemistry. Emissions from indoor sources that contribute to, or are altered by, indoor chemistry have also received attention. Researchers have expanded our awareness of reactive chemicals that can emanate from wood coatings and other products commonly used indoors. In a related vein, a number of recent investigations have shown that emissions from materials can be significantly altered by indoor chemistry. On the theoretical side, an outdoor atmospheric chemistry model has been modified for use as an indoor air model, the effects of ventilation rates on indoor chemistry have been simulated, and initial steps have been taken in applying computational fluid dynamics (CFD) methods to indoor chemistry.
The International Editorship of Freshwater Systems
Authors: Havens Karl E.
Published: March 2005

It is my pleasure to announce that two distinguished internationalscientists have joined the editorship of the FreshwaterSystems domain of TheScientificWorldJOURNAL  Professor BrijGopal of Jawaharlal Nehru University (India) and Dr. Manual Gra柠of the Universityof Coimbra (Portugal). Professor Gopal is the Secretary General of the NationalInstitute of Ecology, Editor of the InternationalJournal of Ecology & Environmental Science,and Chairman of the SIL (International Association of Theoretical and AppliedLimnology) Committee on Limnology in Developing Countries. His research interestsinclude the ecology, biogeochemistry and biodiversity of wetland ecosystems,the management of wetlands as an integral part of the watershed, and wetlandwater policyrelated issues. Dr. Gra柠is a stream ecologist whose researchinterests include the two general areas of organic matter decomposition andbiological monitoring. His specific areas of research focus include quantificationof organic matter and other chemical changes in decomposing leaves, the ecologyof aquatic hyphomycetes, and the ecology of animals feeding on detritus. Hisresearch dealing with biological monitoring is carried out in close cooperationwith the paper and mining industries, facilitating the practical applicationof his work.
Cloning Approaches for Identifying Aging and Longevity-Related Genes in Mammals
Authors: Simoes Davina C. , Gonos Efstathios S.
Published: March 2005

Aging is a phenomenon that affects nearly all animal species. Several studies using different systems have identified a number of processes thought to contribute to the aging phenotype. Many differentially expressed genes have been implicated, but the mechanisms governing mammalian aging (and longevity) are not yet fully understood, and the list of concerned genes is still incomplete and fragmented. Different approaches have been used to clone aging and longevity-related genes. In this article we review these cloning techniques and discuss their advantages and limitations. Further research on the function of these genes as well as the network of their protein products will give better insight into the aging process as a whole and its associated pathologies.
Latent Fingerprint Detection with SYPRO®Rose Plus Protein Blot Stain
Authors: Bouldin Kimberly K. , Menzel E. Roland
Published: March 2005

Lanthanide complexes are employed in photoluminescence detection of fingerprints because their long luminescence lifetimes allow use of time-resolved imaging techniques to suppress problematic background fluorescence. To date, however, these complexes have been unsuccessful when used in developing old fingerprints on porous substrates. SYPRO®Rose Plus Protein Blot Stain remedies this shortcoming; it lends itself to smooth surfaces as well, thus having potential as a universal fingerprint reagent.
Pharmacogenetics of Antiplatelet Drugs
Authors: Curtin Ronan , Fitzgerald Desmond J.
Published: March 2005

Pharmacogenetics refers to the genetic factors that influence the response to a drug, often involving genetic variations in drug metabolizing enzymes. The pharmacogenetics of antiplatelet agents is in its infancy and largely reflects variations in drug targets or related genes. One particular gene variant, the PlA2polymorphism of the glycoprotein (GP) IIb/IIIa receptor, is now emerging as a probable determinant of the response to antiplatelet agents including GPIIb/IIIa antagonists. This variant may in part explain the heterogeneity in the response to GPIIb/IIIa antagonists. The PlA2genotype appears to be associated with an adverse outcome in patients treated with an oral GPIIb/IIIa antagonist and may be a factor in the observed failure of these agents in unselected populations. However, there are preliminary indications that other antiplatelet agents may have an enhanced effect in PlA2subjects. Further clinical trials in particular are required to definitively characterize the pharmacogenetic effect of PlA2. Other polymorphisms are also likely to contribute to the pharmacogenetics of antiplatelet agents, but these await investigation.
Fractionation of Hepatic Nonparenchymal Cells
Authors: Graham John
Published: March 2005

The majority of parenchymal cells from mammalian liver cells can be removed by very low speed centrifugation (50 g) but a simple low-density barrier (1.096 g/ml) is required to remove the remaining parenchymal cells from the 50-g supernatant which contains all of the lower density nonparenchymal cells. Continuous gradients of Nycodenz®can provide satisfactory resolution of Kupffer, stellate, and endothelial cells on an analytical basis but the separation of different cell types is not sufficient preparatively. Flotation through a low-density iodixanol barrier can, however, provide a satisfactory enrichment of the least dense nonparenchymal cell – the stellate cells.
Salinity Preference in Hatchery-Reared Juvenile Red Drum
Authors: Parkyn Daryl C. , Murie Debra J. , Sherwood Edward T.
Published: March 2005

Juvenile red drum (Sciaenops ocellatus), reared in either 15- or 30-ppt salinity seawater, were tested to determine whether they develop preference for the salinity of the water in which they were cultured. In a two-choice test, large- and small-sized juvenile red drum chose the raceway that matched the seawater in which they were cultured over the other salinity. Additional large and small fish reared in either 15- or 30-ppt salinity water were also tested following a 4-h acclimation period that simulated the duration of transport time from the hatchery to a release site. These fish also showed preference for their original culture salinity. This observed salinity preference in juvenile red drum has implications with respect to movement or residency of hatchery-reared juvenile red drum out-planted into natural coastal systems.
Calcitonin Gene-Related Peptide in Tension-Type Headache
Authors: Ashina M.
Published: March 2005

In the last 10 years there has been increasing interest in the role of calcitonin gene-related peptide (CGRP) in primary headaches. Tension-type headache is one of the most common and important types of primary headaches, and ongoing nociception from myofascial tissues may play an important role in the pathophysiology of this disorder. CGRP sensory fibers are preferentially located in the walls of arteries, and nerve fibers containing CGRP accompany small blood vessels in human cranial muscles. It is well established that nociception may lead to release of CGRP from sensory nerve endings and from central terminals of sensory afferents into the spinal cord. It has also been shown that density of CGRP fibers around arteries is increased in persistently inflamed muscle. These findings indicate that ongoing activity in sensory neurons in the cranial muscles may be reflected in changes of plasma levels of neuropeptides in patients with chronic tension-type headache. To explore the possible role of CGRP in tension-type headache, plasma levels of CGRP were measured in patients with chronic tension-type headache. This study showed that plasma levels of CGRP are normal in patients and unrelated to headache state. However, the findings of normal plasma levels of CGRP do not exclude the possibility that abnormalities of this neuropeptide at the neuronal or peripheral (pericranial muscles) levels play a role in the pathophysiology of tension-type headache. Investigation of CGRP in other compartments with new sensitive methods of analysis is necessary to clarify its role in tension-type headache.
Induction of Glutathione Synthesis and Glutathione Reductase Activity by Abiotic Stresses in Maize and Wheat
Authors: Kocsy Gábor , Szalai Gabriella , Gáliba Gabor
Published: March 2005

The effect of different abiotic stresses (extreme temperatures and osmotic stress) on the synthesis of glutathione and hydroxymethylglutathione, on the ratio of the reduced to oxidised forms of these thiols (GSH/GSSG, hmGSH/hmGSSG), and on the glutathione reductase (GR) activity was studied in maize and wheat genotypes having different sensitivity to low temperature stress. Cold treatment induced a greater increase in total glutathione (TG) content and in GR activity in tolerant genotypes of both species than in sensitive ones. The GSH/GSSG and hmGSH/hmGSSG ratios were increased by this treatment only in the frost-tolerant wheat variety. High-temperature stress increased the TG content and the GSH/GSSG ratio only in the chilling-sensitive maize genotype, but GR activity was greater after this treatment in both maize genotypes. Osmotic stress resulted in a great increase in the TG content in wheat and the GR activity in maize. The amount of total hydroxymethylglutathione increased following all stress treatments. These results indicate the involvement of these antioxidants in the stress responses of wheat and maize.
Purification of Peroxisomes in a Preformed Iodixanol Gradient in a Fixed-Angle Rotor
Authors: Graham John
Published: March 2005

In iodixanol, peroxisomes are the densest organelle in the light mitochondrial fraction and are therefore easily separated from the other components (lysosomes, mitochondria, etc.) in a preformed isosmotic continuous gradient. The resolution of the peroxisomes is far superior than that in sucrose and, unlike in Percoll® there is no contamination from endoplasmic reticulum.
Isolation of Rat and Human Hippocampal Neuron Fractions in a Discontinuous Density Gradient
Authors: Graham John
Published: March 2005

The plating efficiency of neurons in culture is highly dependent on the concentration of cells used to establish the monolayer. A discontinuous iodixanol gradient permits both the production of a viable concentrated suspension of neurons and purification from other brain tissue elements. The gradient that is described in this Protocol Article is applicable to brain tissue from rat and also from human biopsy specimens.
Purification of Gastric Mucosal ECL Cells from a Crude Elutriation Fraction
Authors: Graham John
Published: March 2005

Acid-secreting parietal cells from the gastric mucosa are widely studied as a model in studies on ion transport and the endocrine/paracrine ECL cells effectively control parietal cell function. Discontinuous gradients of iodixanol for the purification of ECL cells were subsequently simplified to the use of a density barrier. This technique is now commonly used following initial centrifugal elutriation.
Carcinogenesis and Chemotherapy Viewed from the Perspective of Stoichiometric Network Analysis (SNA): What Can the Biological System of the Elements Contribute to an Understanding of Tumour Induction by Elemental Chemical Noxae (e.g., Ni2+, Cd2+) and to an Understanding of Chemotherapy?
Authors: Franzle Stefan , Markert Bernd
Published: March 2005

The biological application of stoichiometric network analysis (SNA) permits an understanding of tumour induction, carcinogenesis, and chemotherapy. Starting from the Biological System of the Elements, which provides a comprehensive treatment of the functions and distributions of chemical (trace) elements in biology, an attempt is made to interrelate the essential feature of biology and — regrettably — of tumour genesis by superimposing SNA reasoning on common features of all crucial biological processes. For this purpose, aspects, effects and drawbacks of autocatalysis (identical reproduction which can occur either under control or without control [in tumours]) are linked with the known facts about element distributions in living beings and about interference of metals with tumours (in terms of both chemotherapy and carcinogenesis). The essential role of autocatalysis in biology and the drawbacks of either controlled or spontaneous cell division can be used to understand crucial aspects of carcinogenesis and chemotherapy because SNA describes and predicts effects of autocatalysis, including phase effects that may be due to some kind of intervention. The SNA-based classifications of autocatalytic networks in cell biology are outlined here to identify new approaches to chemotherapy.
Is There a Seasonal Difference in the Detection of Trichomonas vaginalis by Cervical Cytology?
Authors: Shrader Sydney , Hernandez Enrique , Gaughan John
Published: March 2005

This objective of our study was to determine the prevalence of a Trichomonas vaginalis diagnosis in routine Papanicolaou smears and whether it is seasonal. We reviewed the diagnosis rendered for 93,681 Papanicolaou smears evaluated at a medical school hospital laboratory between 1992 and 1997. The occurrence of a diagnosis of T. vaginalis was analyzed by year, by quarter, and by month using a generalized linear regression model. The prevalence of a T. vaginalis diagnosis during the 6-year study period was 3.1%. The between-month and between-quarter comparisons of prevalence were not statistically different. In the population reported here, the prevalence of a Papanicolaou smear diagnosis of T. vaginalis was low and no seasonal difference in making this diagnosis was identified.