bluuebunny/crossref_metadata_2025 huggingface dataset:
Behavioural response to the bioavailability of inorganic mercury in the hydrothermal musselBathymodiolus azoricus
Authors: Kádár Enikõ , Costa Valentina , Santos Ricardo S. , Lopes Humberto
Published: January 2005

The hydrothermal vent bivalve Bathymodiolus azoricus is naturally exposed to putatively elevated levels of mercury (Hg), exposure that dates back to the geological occurrence of vent ecosystems, and thus may have evolved evolutionary detoxification mechanisms. Therefore, it was used as a model organism in the present investigation to study the Hg–animal interaction. Mussels were exposed to inorganic Hg by daily administration of 20 μg l-1 Hg for 21 days (cumulative added concentration was 420μg l-1, i.e. ∼2 mmol l-1) under controlled laboratory conditions, and consequent bioaccumulation and detoxification patterns were investigated, while shell gaping behaviour indicative of filtering activity was monitored.

As a result of Hg exposure, significant increase in duration, as well as decline in frequency of shell gaping occurred, which did not recover to pre-exposure levels following 21 days of Hg-free treatment. An increase in the duration of open-shelled status may indicate the absence of an avoidance reaction in the vent mussel coming in contact with Hg, unlike other bivalves that normally close their shells in response to stress compounds. Alternatively, it may suggest that Hg had an inhibitory effect on the adductor muscle function that is responsible for closing the shells. As a result,elevated Hg levels were measured in the soft tissues (270±71 μg g-1 in gills, 245±52 μg g-1 in digestive glands, 93±25 μg g-1 in the mantle and 46±9 μg g-1 in the foot), in byssus threads (peak levels of 442±89μg g-1) and in pseudofaeces (reaching levels as high as 1000μg g-1). Overall, gills contributed 75% to the total Hg body burden followed by mantle (13%), digestive gland (7%), byssus (3%) and foot(2%). Tissue Hg levels remained elevated in mussels transferred to Hg-free seawater even after 21 days, despite the high concentrations persistently eliminated with pseudofaeces both, during and after, exposure.

This potential for bioaccumulation of inorganic Hg (concentration factors reached the order of magnitude of 104) by the vent mussel, which does not seem to prevent uptake by shell closure, suggests that the main Hg-handling strategy is elimination via mucus.
Foraging in a complex naturalistic environment: capacity of spatial working memory in flower bats
Authors: Winter York , Stich Kai Petra
Published: January 2005

Memory systems have evolved under selection pressures, such as the need to remember the locations of resources or past events within spatiotemporally dynamic natural environments. The full repertoire of complex behaviours exhibited by animals in dynamic surroundings are, however, difficult to elicit within simply structured laboratory environments. We have developed a computer-controlled naturalistic environment with 64 feeders for simulating dynamic patterns of water or food resource availability (depletion and replenishment) within the laboratory. The combination of feeder and cage remote control permits the automated transfer of animals between cage and test arena and, therefore, high experimental throughput and minimal disturbance to the animals (bats and mice). In the present study, we investigated spatial working memory in nectar-feeding bats (Glossophaga soricina,Phyllostomidae) collecting food from a 64-feeder array. Feeders gave only single rewards within trials so that efficient foraging required bats to avoid depleted locations. Initially, bats tended to revisit feeders (win-stay), but within three trials changed towards a win-shift strategy. The significant avoidance of revisits could not be explained by algorithmic search guiding movement through the array nor by scent cues left by the bats themselves and,thus, the data suggest that bats remembered spatial locations depleted of food. An examination of the recency effect on spatial working memory after bats shifted to a win-shift strategy indicated that bats held more than 40 behaviour actions (feeder visits) in working memory without indication of decay. This result surpasses previous findings for other taxa.
Muscle remodeling in relation to blood supply: implications for seasonal changes in mitochondrial enzymes
Authors: McClelland G. B. , Dalziel A. C. , Fragoso N. M. , Moyes C. D.
Published: January 2005

We investigated if seasonal changes in rainbow trout muscle energetics arise in response to seasonal changes in erythrocyte properties. We assessed if skeletal muscle mitochondrial enzymes changed (1) acutely in response to changes in erythrocyte abundance, or (2) seasonally when we altered the age profile of erythrocytes. Rainbow trout were treated with pheynylhydrazine,causing a 75% reduction in hematocrit within 4 days. After erythropoiesis had returned hematocrit to normal, treated and control fish were subjected to a seasonal cold acclimation regime to assess the impact of erythrocyte age on skeletal muscle remodeling. Anemia (i.e. phenylhydrazine treatment) did not alter the specific activities (U g-1 tissue) of mitochondrial enzymes in white or red muscle. Anemic pretreatment did not alter the normal pattern of cold-induced mitochondrial proliferation in skeletal muscle,suggesting erythrocyte age was not an important influence on seasonal remodeling of muscle. Anemia and cold acclimation both induced a 25–30%increase in relative ventricular mass. The increase in relative ventricular mass with phenylhydrazine treatment was accompanied by a 35% increase in DNA content (mg DNA per ventricle), suggesting an increase in number of cells. In contrast, the increase in ventricular mass with cold temperature acclimation occurred without a change in DNA content (mg DNA per ventricle), suggesting an increase in cell size. Despite the major increases in relative ventricular mass, neither anemia nor seasonal acclimation had a major influence on the specific activities of a suite of mitochondrial enzymes in heart. Collectively, these studies argue against a role for erythrocyte dynamics in seasonal adaptive remodeling of skeletal muscle energetics.
Flight muscle properties and aerodynamic performance ofDrosophilaexpressing aflightintransgene
Authors: Barton Byron , Ayer Gretchen , Heymann Nicole , Maughan David W. , Lehmann Fritz-Olaf , Vigoreaux Jim O.
Published: January 2005

Flightin is a multiply phosphorylated, myosin-binding protein found specifically in indirect flight muscles (IFM) of Drosophila. A null mutation in the flightin gene (fln0) compromises thick filament assembly and muscle integrity resulting in muscle degeneration and lost of flight ability. Using P-element-mediated transformation with the full-length flightin gene driven by the Actin88F promoter,we have achieved rescue of all fln0-related ultrastructural and functional defects of the IFM. Transgenic P{fln+}fln0 `rescued' flies have fewer thick filaments per myofbril than wild-type flies (782±13 vs945±9) but have otherwise normal IFM. Transgenic P{fln+}fln+ `tetraploid' flies have a normal number of thick filaments. The flightin protein levels in both transgenic strains are similar to wild type. By contrast, flightin levels are reduced in a myosin heavy chain tetraploid strain that produces excess myosin and excess thick filaments. These results suggest that regulation of flightin protein level is independent of gene copy number and that the number of thick filaments assembled per myofibril is influenced independently by myosin and flightin expression. We measured mechanical properties of IFM skinned fibers by sinusoidal analysis and found no significant differences in active viscoelastic properties of flightin-rescued and tetraploid transgenic flies vs wild type. The ability of the fln+transgene to overcome deficits in dynamic stiffness and power output in fln0 suggest that the flightin protein contributes directly to fiber stiffness and stretch activation. However, flight parameters at maximum locomotor capacity, measured in a virtual reality flight simulator,are slightly compromised for both transgenic strains. P{fln+}fln0 and P{fln+}fln+ flies generated enough flight force to sustain hovering flight but showed reduced capability to produce forces in excess of hovering flight force. Both strains showed reductions in stroke frequency but only P{fln+}fln+ showed reductions in stroke amplitude. Muscle and aerodynamic efficiency are similar among the two transgenic strains and wild type. These results illustrate the importance of flightin in flight muscle development and function.
Effect of photoperiod on body mass, food intake and body composition in the field vole,Microtus agrestis
Authors: Król E. , Redman P. , Thomson P. J. , Williams R. , Mayer C. , Mercer J. G. , Speakman J. R.
Published: January 2005

Many small mammals respond to seasonal changes in photoperiod by altering body mass and adiposity. These animals may provide valuable models for understanding the regulation of energy balance. Here, we present data on the field vole (Microtus agrestis) – a previously uncharacterised example of photoperiod-induced changes in body mass. We examined the effect of increased day length on body mass, food intake, apparent digestive efficiency,body composition, de novo lipogenesis and fatty acid composition of adipose tissue in cold-acclimated (8°C) male field voles by transferring them from a short (SD, 8 h:16 h L:D) to long day photoperiod (LD, 16 h:8 h L:D). During the first 4 weeks of exposure to LD, voles underwent a substantial increase in body mass, after which the average difference between body masses of LD and SD voles stabilized at 7.5 g. This 24.8% increase in body mass reflected significant increases in absolute amounts of all body components, including dry fat mass, dry lean mass and body water mass. After correcting body composition and organ morphology data for the differences in body mass, only gonads (testes and seminal vesicles) were enlarged due to photoperiod treatment. To meet energetic demands of deposition and maintenance of extra tissue, voles adjusted their food intake to an increasing body mass and improved their apparent digestive efficiency. Consequently, although mass-corrected food intake did not differ between the photoperiod groups, the LD voles undergoing body mass increase assimilated on average 8.4 kJ day-1 more than animals maintained in SD. The majority(73–77%) of the fat accumulated as adipose tissue had dietary origin. The rate of de novo lipogenesis and fatty acid composition of adipose tissue were not affected by photoperiod. The most important characteristics of the photoperiodic regulation of energy balance in the field vole are the clear delineation between phases where animals regulate body mass at two different levels and the rate at which animals are able to switch between different levels of energy homeostasis. Our data indicate that the field vole may provide an attractive novel animal model for investigation of the regulation of body mass and energy homeostasis at both organism and molecular levels.
Specular Reflection and Diffuse Reflectance Spectroscopy of Soils
Authors: Reeves James B. , Francis Barry A. , Hamilton Stephen K.
Published: January 2005

Studies on the occurrence and effects of specular reflection in mid-infrared spectra of soils have shown that distortions due to specular reflection occur for both organic (humic acid) and non-organic fractions (carbonates, silica, ashed fraction of soil). The results explain why the spectra of CaCO3 in limed soils do not match published spectra and offer an explanation as to why the presence of inorganic C interferes with the development of calibrations for organic C. These results may also have implications for the use of mid-infrared spectra for quantitative and qualitative analysis of soils. For example, libraries of spectra collected by means other than diffuse reflectance would be largely useless for comparing mineral spectra to soil spectra. To obtain the best results with forages and grains, it is necessary to develop separate calibrations for different products, but this has not seemed to be a problem for diverse sets of soil samples with C contents of 0 to 5%. Mid-infrared calibrations have also appeared to be more robust than the corresponding near-infrared calibrations in that fewer outliers are found. However, the results discussed here indicate that at least for some soil types (e.g., large differences in mineralogy or C contents), separate calibrations may be necessary.
Development of a Universal Ellipsoidal Mirror Device for Fluorescence Detected Circular Dichroism: Elimination of Polarization Artifacts
Authors: Nehira Tatsuo , Tanaka Katsunori , Takakuwa Takashi , Ohshima Chie , Masago Hisashi , Pescitelli Gennaro , Wada Akio , Berova Nina
Published: January 2005

We have developed an ellipsoidal mirror fluorescence detected circular dichroism (FDCD) device with enhanced detection sensitivity that eliminates the polarization artifact; this is applicable to samples with strongly polarized fluorescence. The device, JASCO FDCD465, has an ellipsoidal mirror structure with a framework consisting of three mirrors (one elliptical and two plane mirrors) that maximally collects light in the FDCD. All assemblies on the device including the ellipsoidal mirror, cylindrical cell, and photomultiplier tube (PMT) are aligned on the chamber-fitting sample mount as an attachment compatible with a standard CD spectropolarimeter. The new FDCD465 device eliminates the polarization artifact caused by anisotropic distribution of the emitted light. It represents a convenient, reliable, and sensitive FDCD attachment to the JASCO J-800 CD spectrometer series that can be used under both isotropic and photoselected conditions.
In situ Raman Analysis of Gas Formation in NiMH Batteries
Authors: Mank A. J. G. , Belfadhel-Ayeb A. , Krüsemann P. V. E. , Notten P. H. L.
Published: January 2005

In this paper Raman spectrometry is introduced in the field of sealed battery research for in situ gas-phase analysis and for long-term measurements. For this purpose, a new method was successfully applied in order to model battery behavior without interfering with operation. It is shown that oxygen, hydrogen, and nitrogen are responsible for the pressure increase that occurs during overcharging. The relative contribution of the different gases depends on the current imposed on the battery as well as the operating temperature. Reproducible and stable signals could be obtained even under severe conditions such as high pressure and elevated temperature. Oxygen and hydrogen are produced in side reactions taking place during battery operation. However, as nitrogen is unlikely to be a reacting gas inside the battery, the change in its partial pressure can be attributed to electrode expansion and a change in the electrolyte volume.
Solid-Matrix Fluorescence Quenching of Benzo[E]Pyrene and (±)-Anti-Dibenzo[a,l]Pyrene Diolepoxide-DNA Adducts
Authors: Thompson Allison L. , Hurtubise Robert J.
Published: January 2005

The solid-matrix fluorescence (SMF) quenching of benzo[e]pyrene and (±)-anti-dibenzo[a,l]pyrene-11,12-diol-13,14-epoxide ((±)-anti-DB[a,l]PDE)-DNA adducts with thallium nitrate (TlNO3) and sodium iodide (NaI) was examined and several SMF quenching models were developed. The SMF quenching data for B[e]P with either TlNO3 or NaI fit a two-independent-binding-site model. However, the SMF quenching of (±)-anti-DB[a,l]PDE-DNA adducts with TlNO3 fits a sphere of action model, but quenching with NaI was modeled with the two-independent-binding-site model. The data were compared with earlier SMF quenching data for 7,8,9,10-tetrahydroxytetrahydro-benzo[a]pyrene (tetrol I-1) and (±)-anti-benzo[a]pyrene-trans-7,8-dihydrodiol-9,10-epoxide ((±)-anti-BPDE)-DNA adducts. The interpretation of the SMF quenching data for the (±)-anti-DB[a,l]PDE-DNA adducts was distinctively different than the interpretation of the SMF quenching data for the (±)-anti-BPDE-DNA adducts. This initial study shows that SMF quenching has the potential to characterize polycyclic aromatic hydrocarbon-DNA adducts with different numbers of aromatic rings. In addition, the data indicated that external and intercalated DNA adducts interacted with heavy-atom salts in dissimilar fashions. The new SMF methodology developed is useful for the characterization of both polycyclic aromatic hydrocarbon-DNA adducts and metabolites from polycyclic aromatic hydrocarbons.
Human Umbilical Cord Perivascular (HUCPV) Cells: A Source of Mesenchymal Progenitors
Authors: Sarugaser Rahul , Lickorish David , Baksh Dolores , Hosseini M. Morris , Davies John E.
Published: January 2005

We describe the isolation of a nonhematopoietic (CD45−, CD34−, SH2+, SH3+, Thy-1+, CD44+) human umbilical cord perivascular (HUCPV) cell population. Each HUCPV cell harvest (2–5 × 106, depending on the length of cord available) gave rise to a morphologically homogeneous fibroblastic cell population, which expressed α-actin, desmin, vimentin, and 3G5 (a pericyte marker) in culture. We determined the colony-forming unit-fibro-blast (CFU-F) frequency of primary HUCPV cells to be 1:333 and the doubling time, which was 60 hours at passage 0 (P0), decreased to 20 hours at P2. This resulted in a significant cell expansion, producing over 1010 HUCPV cells within 30 days of culture. Furthermore, HUCPV cells cultured in nonosteogenic conditions contained a subpopulation that exhibited a functional osteogenic phenotype and elaborated bone nodules. The frequency of this CFU-osteogenic subpopulation at P1 was 2.6/105 CFU-F, which increased to 7.5/105 CFU-F at P2. Addition of osteogenic supplements to the culture medium resulted in these frequencies increasing to 1.2/104 and 1.3/104 CFU-F, respectively, for P1 and P2. CFU-O were not seen at P0 in either osteogenic or non-osteogenic culture conditions, but P0 HUCPV cells did contain a 20% subpopulation that presented neither class I nor class II cell-surface major histocompatibility complexes (MHC−/−). This population increased to 95% following passage and cryopreservation (P5). We conclude that, due to their rapid doubling time, high frequencies of CFU-F and CFU-O, and high MHC−/− phenotype, HUCPV cells represent a significant source of cells for allogeneic mesenchymal cell-based therapies.
Health Expenditures for Privately Insured Adults Enrolled in Managed Care Gatekeeping vs Indemnity Plans
Authors: Pati Susmita , Shea Steven , Rabinowitz Daniel , Carrasquillo Olveen
Published: January 2005

Objectives. We assessed the ability of managed care gatekeeping strategies (i.e., requiring a designated primary care provider to authorize referrals) to control health care costs in the mid-1990s.

Methods. We analyzed expenditure data from 8195 privately insured adults sampled in the nationally representative 1996 Medical Expenditure Panel Survey. Managed care gatekeeping plan enrollees included those in health maintenance organizations and other plans requiring a primary care gatekeeper. All others were considered indemnity plan enrollees.

Results. In 1996, total per capita annual health expenditures for adult gatekeeping enrollees were about $50 less than those of indemnity enrollees, primarily owing to lower out-of-pocket expenditures. After multivariate adjustment, mean per capita expenditures were approximately 6% lower for gatekeeping enrollees than for indemnity enrollees.

Conclusions. In the private sector, gatekeeping strategies resulted in modest cost savings over indemnity plans.
Comparative Geographic Concentrations of 4 Sexually Transmitted Infections
Authors: Kerani Roxanne P. , Handcock Mark S. , Handsfield H. Hunter , Holmes King K.
Published: January 2005

Objectives. We measured and compared the concentration of primary and secondary syphilis, gonorrhea, chlamydial infection, and genital herpes in a large county with urban, suburban, and rural settings.

Methods. We geocoded sexually transmitted infections reported to King County, Washington health department in 2000–2001 to census tract of residence. We used a model-based approach to measure concentration with Lorenz curves and Gini coefficients.

Results. Syphilis exhibited the highest level of concentration (estimated Gini coefficient = 0.68, 95% confidence interval [CI] = 0.64, 0.78), followed by gonorrhea (estimated Gini coefficient=0.57; 95% CI=0.54, 0.60), chlamydial infection (estimated Gini coefficient = 0.45; 95% CI = 0.40, 0.43), and herpes (estimated Gini coefficient=0.26; 95% CI=0.22, 0.29).

Conclusions. Geographically targeted interventions may be most appropriate for syphilis and gonorrhea. For less-concentrated infections, control strategies must reach a wider portion of the population.
Racial Disparities in Context: A Multilevel Analysis of Neighborhood Variations in Poverty and Excess Mortality Among Black Populations in Massachusetts
Authors: Subramanian S.V. , Chen Jarvis T. , Rehkopf David H. , Waterman Pamela D. , Krieger Nancy
Published: January 2005

Objectives. We analyzed neighborhood heterogeneity in associations among mortality, race/ethnicity, and area poverty.

Methods. We performed a multilevel statistical analysis of Massachusetts all-cause mortality data for the period 1989 through 1991 (n=142836 deaths), modeled as 79813 cells (deaths and denominators cross-tabulated by age, gender, and race/ethnicity) at level 1 nested within 5532 block groups at level 2 within 1307 census tracts (CTs) at level 3. We also characterized CTs by percentage of the population living below poverty level.

Results. Neighborhood variation in mortality across CTs and block groups was not accounted for by these areas’ age, gender, and racial/ethnic composition. Neighborhood variation in mortality was much greater for the Black population than for the White population, largely because of CT-level variation in poverty rates.

Conclusions. Neighborhood heterogeneity in the relationship between mortality and race/ethnicity in Massachusetts is statistically significant and is closely related to CT-level variation in poverty.
Social Anatomy of Racial and Ethnic Disparities in Violence
Authors: Sampson Robert J. , Morenoff Jeffrey D. , Raudenbush Stephen
Published: January 2005

We analyzed key individual, family, and neighborhood factors to assess competing hypotheses regarding racial/ethnic gaps in perpetrating violence. From 1995 to 2002, we collected 3 waves of data on 2974 participants aged 18 to 25 years living in 180 Chicago neighborhoods, augmented by a separate community survey of 8782 Chicago residents.

The odds of perpetrating violence were 85% higher for Blacks compared with Whites, whereas Latino-perpetrated violence was 10% lower. Yet the majority of the Black–White gap (over 60%) and the entire Latino–White gap were explained primarily by the marital status of parents, immigrant generation, and dimensions of neighborhood social context. The results imply that generic interventions to improve neighborhood conditions and support families may reduce racial gaps in violence.
Addressing the Childhood Asthma Crisis in Harlem: The Harlem Children’s Zone Asthma Initiative
Authors: Nicholas Stephen W. , Jean-Louis Betina , Ortiz Benjamin , Northridge Mary , Shoemaker Katherine , Vaughan Roger , Rome Michaela , Canada Geoffrey , Hutchinson Vincent
Published: January 2005

Objectives. We determined the prevalence of asthma and estimated baseline asthma symptoms and asthma management strategies among children aged 0–12 years in Central Harlem.

Methods. The Harlem Children’s Zone Asthma Initiative is a longitudinal, community-based intervention designed for poor children with asthma. Children aged 0–12 years who live or go to school in the Harlem Children’s Zone Project or who participate in any Harlem Children’s Zone, Inc, program were screened for asthma. Children with asthma or asthma-like symptoms were invited to participate in an intensive intervention.

Results. Of the 1982 children currently screened, 28.5% have been told by a doctor or nurse that they have asthma, and 30.3% have asthma or asthma-like symptoms. To date, 229 children are enrolled in the Harlem Children’s Zone Asthma Initiative; at baseline, 24.0% had missed school in the last 14 days because of asthma.

Conclusion. The high prevalence of asthma among children in the Harlem Children’s Zone Project is consistent with reports from other poor urban communities. Intensive efforts are under way to reduce children’s asthma symptoms and improve their asthma management strategies.
Comparative study of the mechanical and flame‐retarding properties of polybutadiene rubber filled with nanoparticles and fly ash
Authors: Mishra S. , Sonawane S. H. , Badgujar N. , Gurav K. , Patil D.
Published: January 2005

A comparative study was performed of fly ash and nano‐CaCO3 as fillers in polybutadiene rubber with 0, 4, 8 and 12% fly ash and nano‐CaCO3. Uniform sheets were prepared of well‐compounded rubber. Nano‐CaCO3 was synthesized by in situ deposition. The CaCO3 nanoparticles as reinforcing agents improved the tensile strength more than 50% than fly ash, and the toughness and hardness also increased significantly. Up to a 75% reduction in flammability and a 100% improvement in the tear strength were observed with nano‐CaCO3.© 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 6–9, 2005
Preparation and surfactancy of branched copolymers from poly(oxyalkylene)‐amine and trichlorotriazine coupling
Authors: Lin J. J. , Huang B. H.
Published: January 2005

A family of branched and block copolymers consisting of poly(oxyalkylene) segments was prepared by using 2,4,6‐trichloro‐1,3,5‐triazine as the amine coupling agent. The copolymers were characterized to have a high molecular weight of up to 22,600 g/mol (Mn) and be thermally stable due to the presence of triazine cores and reactive chloride functionalities. Using the trifunctional poly(oxypropylene)‐block amines as the starting material and a two‐step coupling process, the prepared copolymers are star‐shape or branched, multiple‐block copolymers, with a versatile solubility in water or organic solvents. Further variation in amine structures of hydrophobic poly(oxypropylene) (POP‐) and hydrophilic poly(oxyethylene) (POE‐) blocks may allow the prepared copolymers to be amphiphilic. As an example, the triazine/POP T‐5000/POE ED‐2001 copolymer behaves as a surfactant and exhibits the capability of reducing toluene/water interfacial tension until 1.3 mN/m at critical association concentration as low as 0.001 wt %. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 29–36, 2005
Adsorption of hexavalent chromium by chitosan‐based polymeric surfactants
Authors: Lee Moo‐Yeal , Hong Kyung‐Jin , Shin‐Ya Yoshitsune , Kajiuchi Toshio
Published: January 2005

Chitosan‐based polymeric surfactants (CBPSs) were prepared by the partial N‐acylation of amine groups on chitosan with acid anhydrides. To apply the CBPSs for the removal of Cr(VI) commonly found in wastewater, a batch test was conducted to evaluate the adsorption capacity. The removal efficiency of Cr(VI) by the CBPS depended on several factors, including the solution pH, CBPS dose, and ionic strength. Our results show that the CBPSs exhibited a greater adsorption capacity for Cr(VI) than have other modified chitosans reported in the literature. The maximum adsorption capacity of Cr(VI) was 180 mg/g of CBPS at a final pH of 5.3. From the results of dynamic light scattering, we propose that the removal mechanism of Cr(VI) by the CBPSs was mainly through the adsorption of negatively charged chromium ions by positively charged amine groups on the CBPSs followed by colloidal precipitation because of its lower solubility. Conclusively, we found that the CBPS was significantly effective for the removal of Cr(VI). © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 44–50, 2005
Synthesis and characteristics of semi‐interpenetrating polymer network hydrogels based on chitosan and poly(hydroxy ethyl methacrylate)
Authors: Kim Seon Jeong , Shin Su Ryon , Shin Dong Ik , Kim In Young , Kim Sun I.
Published: January 2005

Semi‐interpenetrating polymer networks (semi‐IPNs), composed of chitosan and poly(hydroxy ethyl methacrylate) hydrogels, were prepared and the effects of various pH, temperatures, and an electric‐field on the swollen hydrogels were investigated. The swelling kinetics increased rapidly, reaching equilibrium within 60 min. Semi‐IPN hydrogels exhibited relatively high swelling ratios, 150∼350%. The swelling ratio increased when the pH of the buffer was below pH 7 as a result of the dissociation of ionic bonds. Semi‐IPN hydrogels showed electroresponsiveness by shrinking when an electric field was applied. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 86–92, 2005
Processing, structure, and mechanical properties of as‐spun polypropylene filaments—A systematic approach using factorial design and statistical analysis
Authors: Yang Ruodan , Mather Robert R. , Fotheringham Alex F.
Published: January 2005

Polypropylene filaments spun under a factorial experimental design were characterized with respect to filament tenacity, elongation, and specific secant modulus. These quantities were assessed quantitatively as responses to seven selected processing parameters using standard statistical methods. It was found that among all the significant factors identified, the draw‐down ratio, which combines metering pump speed (MPS) and filament winding speed (WS), exerts the most significant effects on all the three responses. The grade of polypropylene used, as denoted by its melt flow index (MFI), also significantly influences tenacity and modulus. Spinning temperature, too, influences modulus. In addition, the significant influence of two interaction effects, MPS*WS and MFI*WS, is demonstrated. A further feature of the study is systematic correlation of physical properties with microscopic structure as well as processing conditions. The study has demonstrated that the statistical approach to the development of fiber process technology has the advantages of a one‐step overall design, considerably reduced experimental size, and systematic analysis leading to concise models with known levels of confidence. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 144–154, 2005
Shielding‐effectiveness modeling of carbon‐fiber/nylon‐6,6 composites
Authors: Janda Nicholas B. , Keith Jason M. , King Julia A. , Perger Warren F. , Oxby Troy J.
Published: January 2005

We have formulated a linear theory for the shielding effectiveness of composite matrix materials and have tested the theory for various amounts of ThermalGraph DKD X carbon fiber within nylon 6,6. The theory predicts that the most important parameters for the shielding effectiveness of a sample are the carbon‐fiber volume percentage and the frequency of the wave to be shielded. Although we expected the model to be valid at low filler‐loading levels, it actually performs remarkably, covering an electrical‐resistivity range of 1016 (at low filler‐loading levels) to 101 Ω cm (at high filler‐loading levels), well above the percolation threshold of electrical‐resistivity theory. The model performs much better than those reported in the literature and can be used to determine filler loadings needed to provide a certain level of shielding of electromagnetic waves. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 62–69, 2005
Secretion without membrane fusion: Porocytosis
Authors: Silver Robert B. , Pappas George D.
Published: January 2005

We have recently proposed a mechanism to describe secretion, a fundamental process in all cells. That hypothesis, called porocytosis, embodies all available data and encompasses both forms of secretion, i.e., vesicular and constitutive. The current accepted view of exocytotic secretion involves the physical fusion of vesicle and plasma membranes; however, that hypothesized mechanism does not fit all available physiological data. Energetics of apposed lipid bilayers do not favor unfacilitated fusion. We consider that calcium ions (e.g., 10−4 to 10−3 M calcium in microdomains when elevated for 1 ms or less), whose mobility is restricted in space and time, establish salt bridges among adjacent lipid molecules. This establishes transient pores that span both the vesicle and plasma membrane lipid bilayers; the diameter of this transient pore would be ∼ 1 nm (the diameter of a single lipid molecule). The lifetime of the transient pore is completely dependent on the duration of sufficient calcium ion levels. This places the porocytosis hypothesis for secretion squarely in the realm of the physical and physical chemical interactions of calcium and phospholipids and places mass action as the driving force for release of secretory material. The porocytosis hypothesis that we propose satisfies all of the observations and provides a framework to integrate our combined knowledge of vesicular and constitutive secretion. Anat Rec (Part B: New Anat) 282B:18–37, 2005. © 2005 Wiley‐Liss, Inc.
No effect on cognitive function from daily mobile phone use
Authors: Besset Alain , Espa Fabrice , Dauvilliers Yves , Billiard Michel , de Seze René
Published: January 2005

The increasing use of mobiles phones (MP) has raised the problem of the effects of daily electromagnetic fields (EMF) exposure on human health. To date several studies have been published concerning the effects of acute MP exposure on psychomotor performances. This study investigated the effects of daily exposure to GSM 900 type MP on cognitive function. Fifty‐five subjects (27 male and 28 female) were divided into two groups: a group with MP switched on and a group with MP switched off. The two groups were matched according to age, gender, and IQ. This double blind study lasted for 45 days and was divided in three periods: baseline (BLP, 2 days), exposure (EP, 27 days), and recovery (RP, 13 days). Subjects were exposed during EP and sham exposed during RP for 2 h/day, 5 days/week. The neuropsychological test battery composed of 22 tasks screened four neuropsychological categories: information processing, attention capacity, memory function, and executive function. This neuropsychological battery was performed four times on day 2 (BLP), day 15 (EP), day 29 (EP), and day 43 (RP). Our results indicate that daily MP use has no effect on cognitive function after a 13‐h rest period. Bioelectromagnetics 26:102–108, 2005. © 2005 Wiley‐Liss, Inc.
A theoretical study of the effects of RF fields in the vicinity of membranes
Authors: Barnes F. , Kwon Y.
Published: January 2005

In this article the forces associated with the gradients of a radio frequency (RF) field at the boundary between fluids and cell membranes are calculated, and it is shown that they can be large enough to affect the particle motion by amounts that are on the same order of magnitude as the random diffusion motion when the energy imparted to the particles is a reasonable fraction of the thermal energy. The induced dipole moment is assumed to track the alternating RF so that the force exerted by the gradient is in a constant direction; and this in turn leads to a modification of the particle distribution, even when the energy added to the particle is very small. For RF fields of 45 V/m the energy acquired by an induced dipole moment is expected to be on the order of a micro electron volt and small compared to the average thermal energy. Bioelectromagnetics 26:118–124, 2005. © 2005 Wiley‐Liss, Inc.
Exposure chamber for determining the biological effects of electric and magnetic fields on dairy cows
Authors: Nguyen Duc Hai , Richard Louis , Burchard Javier F.
Published: January 2005

An exposure chamber was designed to study the effects of electric and magnetic fields (EMF) on oestrous cycles, hormonal profile during gestation, pineal function, quantity and quality of milk production, feed intake, and central nervous system of dairy cattle. The chamber was 15 × 10 × 3 m; and the control system was fully computerized so that the field intensities can be varied and monitored continuously, on site or remotely. During exposure to EMF, milk production, feed consumption, and health were monitored closely and blood and cerebral spinal fluid were continuously sampled. The chamber characteristics allow use of a wide range of exposure such as electric fields (0–30 kV/m) and magnetic fields (0–100 μT) at frequencies ranging from 45 to 3000 Hz. Bioelectromagnetics 26:138–144, 2005. © 2005 Wiley‐Liss, Inc.
Sexual behaviors among children and adolescents with acquired brain injury: an incidence survey at a community‐based neurorehabilitation center
Authors: Luiselli James K. , Sherak Donald L. , Dunn Erin K. , Pace Gary M.
Published: January 2005

We conducted a survey to identify the incidence of sexual behaviors among a community sample of children and adolescents with acquired brain injury (ABI). The survey was completed by professional staff at a residential pediatric neurorehabilitation setting and included behaviors observed directly during their employment tenure (1–6 years). The five highest ranked categories of sexual behaviors from a sample of 24 students were (1) masturbation, (2) sex talk, (3) attempted or actual ‘petting/fondling’;, (4) attempt to solicit sex, and (5) verbal sexual threat. Staff identified relatively few students who exhibited sexually coercive or aggressive behaviors. Clinical implications of the findings are discussed. Copyright © 2005 John Wiley & Sons, Ltd.
A critical analysis of data‐based studies examining behavioral interventions with children and adolescents with brain injuries
Authors: Gurdin Lisa Selznick , Huber Sara A. , Cochran Cynthia R.
Published: January 2005

This paper is a review and critical analysis of 20 data‐based studies examining the effects of behavioral interventions with children and adolescents with brain injuries in the rehabilitation, residential, and educational settings. First, the selection criteria and article search methods that were used to locate the studies are described. The procedures for each of the studies are then discussed. The studies are evaluated along several dimensions related to experimental control and are discussed for their significance to both the brain injury and behavioral disciplines. Future areas of research are also proposed. Copyright © 2005 John Wiley & Sons, Ltd.
Enhancing staff performance measures in an acquired brain injury setting: combating the habituation to organizational behavioral interventions
Authors: Guercio John M. , Dixon Mark R. , Soldner James , Shoemaker Zach , Zlomke Kimberly , Root Shannon , Small Stacey
Published: January 2005

The current study examines the utility of a range of behavioral strategies involving group and individual performance feedback for direct care staff in an in‐patient acquired brain injury setting. We first assessed the level of staff completion of behavioral programs for persons with brain injury who resided in one of two residential houses. A weekly percentage score for the entire house was obtained that reflected the completion of behavior programs in each residence. In a multiple baseline fashion across houses we varied the types of feedback intervention introduced to staff, which included in‐service training on the importance of completing behavior programs, a weekly public posting of overall program completion by house, and a weekly public posting of completion of programs by specific staff members. Copyright © 2005 John Wiley & Sons, Ltd.
Enhanced sensitivity of Cypridina luciferin analogue (CLA) chemiluminescence for the detection of .O2− with non‐ionic detergents
Authors: Osman Ahmed Mohamud , Laane Colja , Hilhorst Riet
Published: January 2005

Superoxide anion‐triggered chemiluminescence of Cypridina luciferin analogue (CLA), 2‐methyl‐6‐phenyl‐3,7‐dohydroimidazo[1,2‐α]pyrazin‐3‐one, is enhanced by non‐ionic detergents such as Tween 20, Triton X‐100 and Tween 80. At the concentration of 0.6% (v/v) the largest increase (2.7‐fold) of CLA light intensity was obtained with Tween 20, followed by Tween 80 and Triton X‐100. Using this detergent‐amplified CLA chemiluminescence, the detection limits of xanthine and xanthine oxidase were examined at pH 7.4 and reinvestigated at pH 5.5. At pH 5.5, concentrations of xanthine and xanthine oxidase as low as 5 nmol/L and 3.85 × 10−7 U/mL, respectively, could be accurately determined, whereas, under the experimental conditions used, at pH 7.4 the lowest concentrations of xanthine and xanthine oxidase detectable were 10 nmol/L and 3.85 × 10−6 U/mL. The lowest detectable values of xanthine and xanthine oxidase obtained at pH 5.5 are about 400 and 10 times lower than those previously reported. The detection limit of xanthine (5 nmol/L) by this chemiluminescent‐based method is about 200 and 20 times more sensitive than the determination of xanthine by enzymatic means or by HPLC with detection limits of 1 µmol/L and 0.1 µmol/L, respectively. Our data suggest that this chemiluminescent probe can detect concentrations of superoxide anion below the nanomolar range. Copyright ­© 2001 John Wiley & Sons, Ltd.
Mitochondria and calcium homeostasis: a tale of three luminescent proteins
Authors: Magalhães Paulo J. , Rizzuto Rosario
Published: January 2005

In recent years the jellyfish Aequorea victoria has provided the scientific community with a pair of tools of exceptional usefulness: aequorin and the green fluorescent protein (GFP). Whereas the former has played a major role in the study of calcium signalling, the latter has sparked the imagination of researchers into a myriad of elegant experiments. The firefly Photinus pyralis has also been of great use, providing a third luminescent protein, luciferase, which is mostly known for its role as a reporter protein. Concurrent use of these three proteins provides a powerful means of elucidating biological processes with fine spatio‐temporal detail. Here we will illustrate how specific molecular engineering of these three proteins provided a set of biological tools capable of generating important data in the field of calcium homeostasis. First, we will show how the use of specifically targeted aequorin chimeras enabled the measurement of regional Ca2+ concentrations; second, how the use of GFP (and derived chromatic mutants) permitted detailed morphological analyses in living cells; third, how luciferase was used to analyse energetic requirements at the subcellular level. Together, these three experimental approaches have provided important details on how mitochondria participate actively in calcium homeostasis. A final note regarding clinical implications demonstrates the practical usefulness of the data obtained. Copyright © 2001 John Wiley & Sons, Ltd.
Electrogenerated chemiluminescence of luminol for oxidase‐based fibre‐optic biosensors
Authors: Marquette Christophe A. , Leca Béatrice D. , Blum Loïc J.
Published: January 2005

The luminol electrochemiluminescence has been exploited for the development of several fibre‐optic biosensors allowing the detection of hydrogen peroxide and of substrates of H2O2‐producing oxidases. Electro‐optical flow injection analysis of glucose, lactate, cholesterol and choline are thus described. To perform the experiments, a glassy carbon electrode was polarized at a fixed potential. Luminol was then electrochemically oxidized and could react in the presence of hydrogen peroxide to produce light. Several parameters had to be optimized to obtain reliable optical biosensors. An optimum applied potential of +425 mV between the glassy carbon electrode and the platinum pseudo‐reference electrode was determined, allowing the best signal: noise ratio to be obtained. It was also necessary to optimize the experimental conditions for the immobilization of the different oxidases involved (preactivated membranes, chemically activated collagen membranes, photopolymerized matrix). For each biosensor developed, the optimum reaction conditions have been studied: buffer composition, pH, temperature, flow rate and luminol concentration. Under optimal conditions, the detection limits (S/N = 3) were 30 pmol, 60 pmol, 0.6 nmol and 10 pmol for lactate, glucose, cholesterol and choline, respectively. The miniaturization of electrochemiluminescence‐based biosensors has been realized using screen‐printed electrodes instead of a glassy carbon macroelectrode, with choline oxidase as a model H2O2‐generating oxidase. Copyright © 2001 John Wiley & Sons, Ltd.
Application of an enhanced luminol chemiluminescence reaction using 4‐[4,5‐di(2‐pyridyl)‐1H‐imidazol‐2‐yl]phenylboronic acid to photographic detection of horseradish peroxidase on a membrane
Authors: Kuroda Naotaka , Murasaki Naoko , Wada Mitsuhiro , Nakashima Kenichiro
Published: January 2005

Photographic detection of horseradish peroxidase (HRP) on a membrane by the luminol–hydrogen peroxide–HRP chemiluminescence reaction using 4‐[4,5‐di(2‐pyridyl)‐1H‐imidazol‐2‐yl]phenylboronic acid (DPPA) as an enhancer is described. The method is based on the long‐lived chemiluminescence emission obtained by using DPPA. Under the optimum conditions, as little as 0.10 ng (ca. 2.3 fmol) and 0.20 ng (ca. 4.6 fmol) per spot of HRP on a membrane were detected as visible spots with exposure time of 60 and 10 min, respectively, by using an instant photographic film and a camera luminometer. The proposed method was highly sensitive and was successfully applied to the detection of HRP conjugates as an alternative to the colorimetric method using a chromogenic substrate in a commercially available assay kit of Western blotting. Copyright © 2001 John Wiley & Sons, Ltd.
Intrinsic fluorescence of enzymes and fluorescence of chemically modified enzymes for analytical purposes: a review
Authors: Galbán Javier , Andreu Yolanda , Sierra Jose F. , de Marcos Susana , Castillo Juan R.
Published: January 2005

In recent years our research group has developed new alternatives for fluorescence enzymatic determinations. First, we observed that the intrinsic fluorescence of enzymes changes during enzymatic reactions, proportionally to the substrate concentration, avoiding the combination of the enzymatic reaction with a fluorophore‐involving reaction. The main disadvantage of this method is that the excitation and emission wavelengths of the enzymes are in the UV region of the spectrum. An alternative to overcome this problem consisted of covalently bonding the enzyme to a fluorophore. In this paper, an overview is given of all of the applications and future developments on both types of alternatives that we have developed. Apart from the analytical charactersitics of the methods, we have also reviewed all of the information about mathematical models we have elaborated to date. Copyright © 2001 John Wiley & Sons, Ltd.
Importance of the ionization states of m‐THPC for its HPLC fluorescence detection
Authors: Desroches M.‐C. , Bourdon O. , Morokro Y. , Chaminade P. , Blais J. , Prognon P. , Kasselouri A.
Published: January 2005

An original, rapid and sensitive high‐performance liquid chromatographic (HPLC) method has been developed for the detection of 5, 10, 15, 20 tetra‐meso‐hydroxyphenylchlorine (m‐THPC), a photosensitizer used in the photodynamic therapy (PDT) of cancers. Chromatographic separation was carried out on a C8 Zorbax® column (80 × 4 mm, 5 µm). The mobile phase was an ethanol/aqueous sulphuric acid, pH 2.0 (65/35 v/v), in an isocratic mode yielding to rapid analysis (3.1 min) with narrow peaks. As the fluorescence intensity was found to be highly pH‐dependent and to increase with pH values, a post‐column device prior to the fluorescence detection (λexc = 423 nm, λem = 650 nm) was used to allow the addition of a 0.05 mol/L Na2HPO4 solution to the mobile phase. Compared to standard conditions, a 300% increase of the fluorescence intensity was obtained for optimized operating conditions using experimental design. The validation of this analytical method showed that the response function was linear for concentrations up to 1000 µg/L (1.47 × 10−6 mol/L) with a detection limit of 188 pg (S/N = 3). Copyright © 2001 John Wiley & Sons, Ltd.