bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impediments to Secretion of Green Fluorescent Protein and Its Fusion from Saccharomyces cerevisiae
Authors: Li Jincai , Xu Haixin , Bentley William E. , Rao Govind 
Published: September 2002

AbstractWhile it has been demonstrated that GFP‐tagged proteins were transported to their correct cellular compartments in most cells, attempts to secrete GFP/GFP‐fusion through the default secretory pathway have not been as successful. In an attempt to induce secretion of GFP and Hexokinase (HXK)‐GFP fusion in Saccharomycescerevisiae, we have cloned constructs that employed four different yeast secretion signal sequences, i.e., INU1, SUC2, PHO5, and MEL1. The expression is under the control of the galactose‐inducible GAL1promoter. Our results showed that all eight constructs entered the secretory pathway successfully, and the signal peptides were all cleaved off. However, none of the eight constructs were able to lead to secretion into the culture media or the periplasmic space. The expression levels of the eight constructs differ dramatically, depending on both the signal peptide and whether GFP was fused with HXK. Confocal microscopy studies revealed that the eight constructs also led to very different localization patterns. Among them, two constructs targeted GFP to the vacuole partially or exclusively, whereas others were mostly retained in the ER/Golgi compartments. Our efforts, together with those of others, seem to suggest that the signal peptide itself is not enough to lead to secretion of GFP from S. cerevisiae, although it has been successful in some other organisms. Nonetheless, the advantage of GFP's in vivo detection makes it a powerful tool for investigating protein localization events.
Insect Cell Culture Medium Supplementation with Fetal Bovine Serum and Bovine Serum Albumin: Effects on Baculovirus Adsorption and Infection Kinetics
Authors: Maranga Luis , Coroadinha Ana S. , Carrondo Manuel J. T. 
Published: September 2002

AbstractThe effects of insect cell culture medium supplementation with FBS were investigated. BSA was found to be the factor responsible for the increased baculovirus infection rate of FBS‐supplemented cultures in a concentration‐dependent form up to 25 g L−1. Lower rates of baculovirus binding to cells were observed with FBS‐ and BSA‐supplemented cultures compared with infections carried out in serum‐free media. Virus attachment constants were found to depend on medium matrix composition. An efficiency factor dependent on the medium matrix composition was introduced to account for these effects, and a mathematical model was developed to describe the virus‐cell interactions. It was shown that BSA acts by minimizing the nonspecific virus binding leading to an increased cell infection rate. Cell specific Porcine parvovirusvirus‐like particles (PPV‐VLPs) expression was unaffected by medium supplementation pointing out that BSA and/or FBS affects mainly the initial phase of the baculovirus infection cycle. Implications for process definition are discussed.
Integrated Earth and Environmental Evolution of the Southwestern United States: The Clarence A. Hall Jr., Volume
Authors: Busby Cathy Jeanne 
Published: September 2002

This Geological Society of America (GSA) volume was produced in honor of Clarence Hall, Professor of Geology at the University of California, Los Angeles, after his retirement, to call attention to his “administrative and scientific contributions as well as to his dynamic, visionary leadership” (editors' introduction). The volume has 23 papers and is divided into four sections.In the first paper of the volume, “Archean Tectonics and Magmatism,” Warren Hamilton does one of the things he does best: stir up controversy! As a longtime fan of the greenstone belt literature, I found Hamilton's summary of the case against Archean plate tectonics very convincing. In contrast, his arguments that ”plumes probably do not exist in the modern Earth“ (and therefore should not be used to explain Archean geology) are completely unconvincing and ignore a wealth of seismological evidence for present‐day plumes and superplumes.
Effect of canopy structure and the presence of snow on the albedo of boreal conifer forests
Authors: Ni Wenge , Woodcock Curtis E. 
Published: September 2002

A Geometric‐Optical and Radiative Transfer (GORT) approach for modeling the radiation regime within plant canopies is capable of predicting temporal variation in the albedo of boreal conifer forests. Model predictions of daily surface albedo patterns and reflected solar radiation during the winter and summer seasons were validated using field measurements from two forest stands in the northern study area of BOReal Ecosystem‐Atmosphere Study (BOREAS) in 1995. The model is able to predict the “W” shape for the daily albedo over the sparse old jack pine forest stand during the snow season and the “bowl” shape of daily albedo during clear days in the summer. Results immediately following new snow and at the end of the snowmelt season indicate the sensitivity of overall forest albedos to the albedo of snow. Incorporation of time‐varying values for snow albedo may improve future efforts to estimate forest albedos in the winter.Forest albedos are a complicated function of the canopy structure, the presence or absence of snow on the ground and the angular distribution of irradiance. These effects differ for the visible, near‐infrared and midinfrared portions of the solar spectrum. Forest albedos vary dramatically as a function of canopy cover when snow covers the ground, but very little when snow is not present. It is found that for tree cover over about 70%, the presence of snow has little effect on albedo.
Introduction to special section: Southern Oxidants Study Nashville/Middle Tennessee Ozone Study, Part 2
Authors: Cowling E. B. , Chameides W. L. , Kiang C. S. , Fehsenfeld F. C. , Meagher J. F. 
Published: September 2002

The 12 papers in this second Southern Oxidants Study (SOS) special section of the Journal of Geophysical Research‐Atmospheres constitute a significant addition to earlier scientific contributions from the SOS: Fehsenfeld et al. [1993], Chameides and Cowling [1995], first special section “;Southern Oxidants Study” in the Journal of Geophysical Research, 103 (D17), 22, 209‐22,669, 1998, and North Carolina State University [1999].These 12 papers give special emphasis to advances in scientific understanding of chemical, meteorological, and biological factors that govern accumulation of ozone and other oxidants in the lower troposphere within the 11‐state study area centered over Nashville, Tennessee. The aircraft and ground‐based fieldwork portions of SOS' Nashville/Middle Tennessee Ozone Study were completed during the summers of 1994 and 1995. In‐depth analysis and interpretation of measurements made during those two summers has continued, and will likely continue for some years in the future. Readers of this second SOS special section needing background information on the Nashville/Middle Tennessee Ozone Study should consult the four overview papers published in the first SOS special section [Cowling et al., 1998; Meagher et al., 1998; McNider et al., 1998; Hübler et al., 1998].
The tectonic evolution of the Kohistan‐Karakoram collision belt along the Karakoram Highway transect, north Pakistan
Authors: Searle M. P. , Khan M. Asif , Fraser J. E. , Gough S. J. , Jan M. Qasim 
Published: September 2002

The Kohistan arc terrane comprises an intra‐oceanic island arc of Cretaceous age separating the Indian plate to the south from the Karakoram (Asian) plate to the north within the Indus suture zone of north Pakistan. The intra‐oceanic arc volcanics (Chalt, Dras Group) were built on a foundation of dominantly mid‐ocean ridge basalt (MORB)‐related amphibolites of the Kamila Group. The subarc magma chamber is represented by multiple intrusions of a huge gabbro‐norite complex (Chilas complex), which includes some ultramafic assemblages of residual mantle harzburgite and dunite, layered cumulates, and hornblendites cut by late stage dikes of hornblende + plagioclase pegmatites. The Chilas complex norites intrude the Gilgit metasediments of lower amphibolite and greenschist facies in northern Kohistan, which also form xenolithic roof pendants within the top of the Chilas complex. Along the southern margin of Kohistan, Jijal and Sapat complex ultramafics (dunites, harzburgites and websterites) form remnant suprasubduction zone ophiolitic mantle rocks along the hanging wall of the Main Mantle Thrust, the Cretaceous obduction plane along which Kohistan was emplaced onto Indian plate rocks. Garnet granulites of the Jijal complex, formed at 12–14 kbars, represent original magmatic lower crustal rocks subducted to depths of at least 45 km and metamorphosed during high‐pressure and high‐temperature subduction of earlier arc‐related rocks. Obduction of the Sapat ophiolite and Kohistan arc occurred between ∼75 and 55 Ma.The closure of the Shyok suture zone separating Kohistan from the Karakoram plate must have occurred prior to 75 Ma, the age of the Jutal basic dikes which crosscut the closure‐related fabrics, mainly late north directed backthrusting in the lower Hunza valley. Andean‐type granitoid (gabbrodiorite‐granodiorite‐granite) emplacement along the Kohistan‐Ladakh batholith ended at the time of India‐Asia collision, ∼ 60–50 Myr ago. Postcollisional crustal thickening along the Karakoram led to multiple episodes of metamorphism from latest Cretaceous and throughout the Tertiary. Sillimanite grade metamorphism in Hunza was actually pre‐India‐Asia collision and may have resulted from the earlier Kohistan collision. Localized and sporadic crustal melting episodes across northern Kohistan (Indus confluence and Parri granite sheets) and the southern Karakoram (Hunza dikes and Sumayar and Mango Gusar leucogranites) occurred from 51 to 9 Ma and culminated in the huge Baltoro monzogranite‐leucogranite intrusion 25–21 Myr ago. A vast network of leucogranitic and pegmatitite dikes containing gem quality aquamarine + muscovite ± tourmaline ± garnet ± biotite quartz are younger than 5 Ma and form the final phase of intrusion in the Haramosh area and parts of the southern Karakoram area.
Geophysicists
Authors: Anonymous  
Published: September 2002

Industrial pollution declined 2.3% in the United States and Canada in 1996, continuing a dip during the previous 2 years, according to the Commission for Environmental Cooperation's (CEC) August 10 report, “Taking Stock 1996.” The report says the decline also continues beyond 1996.Large manufacturing facilities in the United States and Canada that reported information to CEC produced 1.225 billion kg of pollution in 1996, compared to 1.254 billion kg in 1995, the report says.
Group calls for protecting Great Lakes water
Authors: Showstack Randy 
Published: September 2002

Neither Canadian nor United States governments should allow any surface or groundwater removals from the Great Lakes Basin that endanger the region and its ecosystem, an intergovernmental body recommended on August 18.In addition, the governments should lower substantially the trigger point for proposed new or increased water use that require notice, consultation, and the seeking of consent and concurrence, said the International Joint Commission (IJC).
Bioenergy and biobased products hold promise of reducing pollution emissions
Authors: Showstack Randy 
Published: September 2002

Trees and other plants have, of course, long been useful for the wood and agricultural benefits they provide. Now, this organic matter is gaining new cachet as “biomass.”Some scientists hope that this stuff can be converted into practically a panacea of goods, including transportation fuels, electricity, commercial products such as chemicals, glues, and paints, and other materials—reducing societal dependence on petrochemical products.
Remembering Robert Goddard's vision 100 years later
Authors: Stern David P. 
Published: September 2002

“Life, liberty, and the pursuit of happiness” —such are the goals of most of us.Yet a few always exist who feel called by a higher purpose. Society often owes them a great deal.Robert Hutchins Goddard, whose work made spaceflight possible, found his vision 100 years ago this October as a youth of 17. His family was staying on the farm of a relative, when he was asked to trim the branches of a cherry tree behind the barn.
Recent trends in progressive power lenses
Authors: Fowler Colin 
Published: September 2002

SummaryDespite having been first marketed in the 1950s, new designs of progressive addition spectacle lens continue to appear. Some of the recent patent literature is reviewed on the design of such lenses. As well as a number of improvements to general purpose designs, specifically to include aspheric surfaces for the distance portion of progressive lenses, the literature includes a recent patent on an improved version of the Alvarez lateral translation lens system. The optimisation of single vision lens forms in order to extend the depth of field for early presbyopes is also discussed.
The pharmacological basis of anterior segment therapy
Authors: Vale Janet 
Published: September 2002

SummaryThe main concerns in anterior segment therapy are allergy, inflammation and infection. Allergic reactions can be divided into four types with differing etiologies. Although all types may be manifested in ocular inflammatory states, Type I, involving the release of histamine is probably the most common, being involved in responses to pollen, drugs and in GPC and VKC. Inflammation is a complex, multicomponent, protective response involving the synthesis, release and actions of many chemical mediators, including prostaglandins which are synthesised from cell membrane components. Drugs used act through a number of mechanisms: decongestants act directly on dilated vessels to cause constriction and decreased permeability; antihistamines block the access of histamine to its receptors in the target tissues and mast cell stabilisers prevent the release of mediators including histamine in response to the antigen/antibody interaction. Both the non‐steroidal anti‐inflammatory drugs and steroids decrease the production of the prostaglandins by inhibiting the action of cyclo‐oxygenase and phospholipase respectively. Most infections are bacterial and the majority of drugs used are antibacterial. However, many of the principles of antibacterial therapy can be applied to the other classes of drugs. The basic principle in the treatment of any infection is that of selective toxicity, which is the ability to effect harm to the infecting cells (e.g. bacteria) without a similar effect being exerted on the host cells. This selectivity may be qualitative, at no drug concentration is the host cell affected in the same way as the invading cell, or quantitative where the separation of effect is dose dependent. The selectivity may have a biochemical or distributional basis, and the effects may be, in the case of bacteria, bactericidal or bacteriostatic. Most antibiotics used in anterior segment therapy show quantitative biochemical selectivity and are bacteriostatic in action. The antiviral compound (aciclovir) shows quantitative biochemical selectivity because it is a pro‐drug activated in infected cells.
Prevalence of ‘non‐hexagonal’ cells in the corneal endothelium of young Caucasian adults, and their inter‐relationships
Authors: Doughty Michael J. 
Published: September 2002

SummaryThe corneal endothelium is often described as a mosaic of hexagonal cells, despite numerous reports that the relative number of ‘hexagonal’ cells is often only around 65%. Such estimates also cannot define the relative area contribution to the cell mosaic of either these cells, or those that are not 6‐sided. Specular micrographs were therefore taken of 20 healthy young Caucasian adults aged 21 to 34 years and the apical surface areas of at least 105 contiguous cells from each central corneal endothelium measured by planimetry. The numbers of each cell type and their surface areas were assessed so that the summated area occupied by each cell type could be calculated. The results reveal that endothelia that show only modest variance in cell areas are usually composed of 4‐, 5‐, 6‐, 7‐ and 8‐sided cells. Assessments of relative contribution of each cell type to the mosaic indicates that the 6‐sided cells can be expected to constitute just over 60% of the total cell area. Increases in the variance in the areas across all the cells can be strongly correlated with a reduction in the 6‐sided cells and increases in the 5‐ and 7‐sided cells. Each cell type (4‐, 5‐, 6‐sided etc) has a preferred area that is proportional to other cells. The results firmly indicate that the mosaic is not random and follows a specific order that is presumably dictated by the physics of cell packing. These methods of comparing endothelia should allow distinctions to be made between endothelia that are different, versus being abnormal (i.e. with disease).
Modelling adaptation effects in vergence and accommodation after exposure to a simulated Virtual Reality stimulus
Authors: Eadie A. S. , Gray L. S. , Carlin P. , Mon‐Williams M. 
Published: September 2002

SummaryNatural viewing conditions place equal demands on the vergence and accommodation systems. The two responses are co‐ordinated via the interactive components which couple the two systems: accommodative vergence and vergence accommodation. The crosslink components are usually quantified by the AC/A and CA/C ratios. Whether these ratios are stable entities, genetically determined, or modifiable by experience has been the subject of some debate. A ‘Virtual Reality’ stimulus was used to place unequal demands on the vergence and accommodation systems. Pre‐task and post‐task measures of AC/A and CA/C were objectively determined. The changes in the post‐task measures are discussed with reference to a dual interactive model of vergence and accommodation. Model simulations suggest that adaptation of the vergence and accommodative controllers (tonic adaptation) may also play a part by altering the open loop bias. The results therefore support the idea that vergence accommodation and accommodative vergence are capable of adaptation.
Towards a colorimetric characterization of the human iris
Authors: Melgosa M. , Rivas M. J. , Gómez L. , Hita E. 
Published: September 2002

SummaryWe propose a new approach to the quantitative determination of the iris colour through the spectroradiometric measurement of a set of 72 artificial irises under controlled illumination and geometry. The spread of these samples in the CIELAB colour space indicates no clearly distinguished groups within the set analysed. Colour measurements for different points of these irises and for the overall irises (pupil and specular image of the light source included) are well correlated. Complementary colour measurements were also performed for the irises of 25 ocular prostheses and 40 real observers. All these colour measurements appear to be quite consistent, the average standard deviation of any of the three a*, b*, L* co‐ordinates being lower than 1.0 units. In a visual experiment where 11 normal observers matched the 25 ocular prostheses using the 72 artificial irises, the results indicate that a simple criterion based on the lowest colour‐difference agreed with the observers’judgements in only 18% of the cases. This result suggests that, although colour appears to be a major parameter in the overall characterization of the human iris, additional factors such as patterns or textures should also be considered.
Further analysis of the size and shape of cells obtained by impression cytology from the exposed portion of the human bulbar conjunctiva
Authors: Doughty Michael J. , Blades Kenneth , Button Norman F. , Wilson Graeme 
Published: September 2002

Summary Purpose: To assess whether the size of the cells obtained by conjunctival impression cytology can be quantitatively assessed by measurement of the longest dimension of the cells. Methods: Under topical benoxinate anaesthesia, cells were removed from the normally exposed nasal bulbar conjunctival surface using a 0.4 μm pore diameter filter (Biopore® filter; type Millcell®‐CM). The filters were stained with haematoxylin after ethanol denaturation, photographed at 40× magnification, and 35 mm slides prepared. An optical overlay method was used to outline the borders of sets of 30–35 contiguous cells on each image. The cell area, longest and shortest dimensions were measured by planimetry to an accuracy of ±3%. Results: Analyses of 20 sets of samples, from individuals aged 21 to 48 years and without clinically significant ocular surface disease, revealed a median cell area of 133 μm2 (n=621, range 46–1602 μm2; average 212 μm2), a median longest dimension of 13.9 μm (range 6.6–68.8 μm; average 16.9 μm) and a shorter dimension of 10.0 μm (range 4.7–43.0 μm; average 11.9 μm); the distributions of values indicated bimodality. Most cells had a long:short ratio (L:S ratio) value between 1.00 and 1.80, but 11.9±6.1% of the cells had L:S ratios between 1.80 and 4.60. The overall relationship between the longest dimension and the area of the cells was non‐linear, with cells having larger L:S ratios having disproportionately smaller areas. Conclusions: The superficial conjunctival cells are small, and their longest dimensions are systematically related to area. Analyses of cell shape indicate further possible ways of identifying different cells on the bulbar conjunctiva. Compared to literature values, there is a substantial overlap in longest dimensions of the conjunctival cells with those of cells that can be collected off the corneal surface. This means that superficial conjunctival and corneal cells cannot be distinguished simply on the basis of measurements of the long dimension.
Observer variability in optic disc assessment: implications for glaucoma shared care
Authors: Harper Robert , Reeves Barnaby , Smith George 
Published: September 2002

SummaryDemonstrating that optometrists can make valid and reliable assessments of optic disc features is an important prerequisite for establishing schemes for shared care/co‐management. Previous studies have estimated observer variability among experts in the assessment of optic disc cupping, but there has been a paucity of information on observer variability amongst optometrists. This paper describes a study to investigate intra‐ and inter‐observer variability for a range of disc features, as graded by both ophthalmologists and optometrists. Five observers (three optometrists and two ophthalmologists) graded 48 stereo‐pairs of optic disc photographs from 48 patients on two separate occasions. Each observer graded the following features: vertical and horizontalC/D ratios, narrowest rim width, the presence/absence of a disc haemorrhage, focal pallor of the neuroretinal rim, peri‐papillary atrophy, the steepness of the cup‐edge and the presence/absence of the cribriform sign. The average intra‐ and inter‐observer standard deviation (SD) of differences are, respectively, 0.11 and 0.19 for the verticalC/D ratios and 0.10 and 0.18 for the horizontalC/D ratios. For the verticalC/D ratio the average weighted kappa (κw) is 0.79 within observers and 0.46 between observers. Percentage agreements for the presence/absence of a disc haemorrhage range from 96 to 100% (averageκ=0.92) within observers and from 90 to 98% (averageκ=0.77) between observers. For other disc features, averageκw values range from 0.67 to 0.71 within observers and from 0.23 to 0.46 between observers. Intra‐and inter‐observer comparisons (within and between different professionals) across all disc features are comparable for the optometrists and ophthalmologists, thus demonstrating that optometrists can make valid assessments of disc features. The implications for shared care are discussed.