bluuebunny/crossref_metadata_2025 huggingface dataset:
BENTHIC AND PLANKTONIC ALGAL COMMUNITIES IN A HIGH ARCTIC LAKE: PIGMENT STRUCTURE AND CONTRASTING RESPONSES TO NUTRIENT ENRICHMENT1
Authors: Bonilla Sylvia , Villeneuve Valérie , Vincent Warwick F.
Published: December 2005

We investigated the fine pigment structure and composition of phytoplankton and benthic cyanobacterial mats in Ward Hunt Lake at the northern limit of High Arctic Canada and the responses of these two communities to in situ nutrient enrichment. The HPLC analyses showed that more than 98% of the total pigment stocks occurred in the benthos. The phytoplankton contained Chrysophyceae, low concentrations of other protists and Cyanobacteria (notably picocyanobacteria), and the accessory pigments chl c2, fucoxanthin, diadinoxanthin, violaxanthin, and zeaxanthin. The benthic community contained the accessory pigments chl b, chl c2, and a set of carotenoids dominated by glycosidic xanthophylls, characteristic of filamentous cyanobacteria. The black surface layer of the mats was rich in the UV‐screening compounds scytonemin, red scytonemin‐like, and mycosporine‐like amino acids, and the blue‐green basal stratum contained high concentrations of light‐harvesting pigments. In a first bioassay of the benthic mats, there was no significant photosynthetic or growth response to inorganic carbon or full nutrient enrichment over 15 days. This bioassay was repeated with increased replication and HPLC analysis in a subsequent season, and the results confirmed the lack of significant response to added nutrients. In contrast, the phytoplankton in samples from the overlying water column responded strongly to enrichment, and chl a biomass increased by a factor of 19.2 over 2 weeks. These results underscore the divergent ecophysiology of benthic versus planktonic communities in extreme latitudes and show that cold lake ecosystems can be dominated by benthic phototrophs that are nutrient sufficient despite their ultraoligotrophic overlying waters.
NOMENCLATURAL NOTE ON A THECADINIUM SPECIES (DINOPHYCEAE, GONYAULACALES), WHICH WAS DESCRIBED AS NEW INDEPENDENTLY THREE TIMES WITHIN TWO MONTHS1
Authors: Hoppenrath Mona , Bolch Christopher J. S. , Yoshimatsu Sadaaki , Saldarriaga Juan F. , Schweikert Michael , Campbell Christine N. , Toriumi Saburo , Dodge John D. , Elbrächter Malte , Taylor F. J. R.
Published: December 2005

Three Thecadinium species, independently described as new in three separate publications, are actually regarded as conspecific. The combined plate formula is Po 3′ 1a 6″ 5‐7/8c 5s 6″′ 2″″. The size range of the species is 38–65 l m in length and 23–42 lm in depth. It has one or two strongly lobed chloroplasts. The correct name of the species is Thecadinium yashimaense Yoshimatsu, Toriumi et Dodge 2004. Thecadinium mucosum Hoppenrath et Taylor 2004 and Thecadinium foveolatum Bolch 2004 are taxonomical synonyms. This note clarifies the plate tabulation and other features of the species.
Epidemiology of Gait Disorders in Community‐Residing Older Adults
Authors: Verghese Joe , LeValley Aaron , Hall Charles B. , Katz Mindy J. , Ambrose Anne F. , Lipton Richard B.
Published: December 2005

OBJECTIVES:To study the epidemiology of gait disorders in community‐residing older adults and their association with death and institutionalization.

DESIGN:Community‐based cohort study.

SETTING:Bronx County and the research center at Albert Einstein College of Medicine.

PARTICIPANTS:The Einstein Aging study recruited 488 adults aged 70 to 99 between 1999 and 2001. At entry and during annual visits over 5 years, subjects received clinical evaluations to determine presence of neurological or nonneurological gait abnormalities.

MEASUREMENTS:Prevalence and incidence of gait disorders based on clinical evaluations and time to institutionalization and death.

RESULTS:Of 468 subjects (95.9%) with baseline gait evaluations, 168 had abnormal gaits: 70 neurological, 81 nonneurological, and 17 both. Prevalence of abnormal gait was 35.0% (95% confidence interval (CI)=28.6–42.1). Incidence of abnormal gait was 168.6 per 1,000 person‐years (95% CI=117.4–242.0) and increased with age. Men had a higher incidence of neurological gait abnormalities, whereas women had a higher incidence of nonneurological gaits. Abnormal gaits were associated with greater risk of institutionalization and death (hazard ratio (HR)=2.2, 95% CI=1.5–3.2). The risk was strongly related to severity of impairment; subjects with moderate to severe gait abnormalities (HR=3.2, 95% CI=1.9–5.2) were at higher risk than those with mild gait abnormalities (HR=1.8, 95% CI=1.0–2.8).

CONCLUSION:The incidence and prevalence of gait disorders are high in community‐residing older adults and are associated with greater risk of institutionalization and death.
The Effects of a Variant of the Program for All‐inclusive Care of the Elderly on Hospital Utilization and Outcomes
Authors: Kane Robert L. , Homyak Patricia , Bershadsky Boris , Flood Shannon
Published: December 2005

OBJECTIVES: To compare the effects of the Wisconsin Partnership Program (WPP) on hospital, emergency department (ED), and nursing home utilization with those of traditional care.

DESIGN: Quasi‐experimental longitudinal cohort design.

SETTING: Selected counties in Wisconsin.

PARTICIPANTS: WPP elderly enrollees and two matched control groups consisting of frail older people enrolled in fee‐for‐service insurance plans, Medicare, and Medicaid and receiving home‐ and community‐based waiver services, one from the same geographic area as the WPP and another from a location in the state where the WPP was not offered.

MEASUREMENTS: Data came from administrative records. Regression and survival analyses were adjusted for case‐mix variables.

RESULTS: No significant differences in hospital utilization, ED visits, preventable hospitalizations, risk of entry into nursing homes, or mortality were found. WPP enrollees had more contact with care providers than did controls.

CONCLUSION: WPP did not dramatically alter the pattern of care. Part of the weak effect may be attributable to the small numbers of WPP cases per participating physician.
Assessing the Appropriateness of Pain Medication Prescribing Practices in Nursing Homes
Authors: Hutt Evelyn , Pepper Ginette A. , Vojir Carol , Fink Regina , Jones Katherine R.
Published: December 2005

OBJECTIVES: To test a tool for screening the quality of nursing home (NH) pain medication prescribing.

DESIGN: Validity and reliability of measurement tool developed for a pre/postintervention with untreated comparison group.

SETTING: Six treatment NHs and six comparison NHs in rural and urban Colorado.

PARTICIPANTS: NH staff, physicians, and repeated 20% random sample of each home's residents (N=2,031).

INTERVENTION: Nurse and physician education; NH internal pain team to champion better pain management using a pain vital sign, consultations, and rounds.

MEASUREMENTS: An expert panel reviewed the Pain Medication Appropriateness Scale (PMAS) for content validity. Research assistants interviewed NH residents, assessed them for pain using standardized instruments, and reviewed their medical records for prescriptions and use of pain and adjuvant medication. Construct validity was assessed by comparing the PMAS of residents in pain with the PMAS of those not in pain and comparing scores in homes in which the intervention was more effective with those in which it was less effective, using the Fisher exact and Student t tests. Interrater and test‐retest reliability were measured.

RESULTS: The mean total PMAS was 64% of optimal. Fewer than half of residents with predictably recurrent pain were prescribed scheduled pain medication; 23% received at least one high‐risk medication. PMAS scores were better for residents not in pain (68% vs 60%, P=.004) and in homes where nurses' knowledge of pain assessment and management improved or stayed the same during the intervention (69% vs 61%, P=.03).

CONCLUSION: The PMAS is useful for assessing pain medication prescribing in NHs and elucidates why so many residents have poorly controlled pain.
Ten Dimensions of Health and Their Relationships with Overall Self‐Reported Health and Survival in a Predominately Religiously Active Elderly Population: The Cache County Memory Study
Authors: Østbye Truls , Krause Katrina M. , Norton Maria C. , Tschanz JoAnn , Sanders Linda , Hayden Kathleen , Pieper Carl , Welsh‐Bohmer Kathleen A. ,   for the Cache County Investigators
Published: December 2005

OBJECTIVES: To document the extent of healthy aging along 10 different dimensions in a population known for its longevity.

DESIGN: A cohort study with baseline measures of overall self‐reported health and health along 10 specific dimensions; analyses investigated the 10 dimensions as predictors of self‐reported health and 10‐year mortality.

SETTING: Cache County, Utah, which is among the areas with the highest conditional life expectancy at age 65 in the United States.

PARTICIPANTS: Inhabitants of Cache County aged 65 and older (January 1, 1995).

MEASUREMENTS: Self‐reported overall health and 10 specific dimensions of healthy aging: independent living, vision, hearing, activities of daily living, instrumental activities of daily living, absence of physical illness, cognition, healthy mood, social support and participation, and religious participation and spirituality.

RESULTS: This elderly population was healthy overall. With few exceptions, 80% to 90% of persons aged 65 to 75 were healthy according to each measure used. Prevalence of excellent and good self‐reported health decreased with age, to approximately 60% in those aged 85 and older. Even in the oldest old, the majority of respondents were independent in activities of daily living. Although vision, hearing, and mood were significant predictors of overall self‐reported health in the final models, age, sex, and cognition were significant only in the final survival models.

CONCLUSION: This population has a high prevalence of most factors representing healthy aging. The predictors of overall self‐reported health are distinct from the predictors of survival in this age group and, being potentially modifiable, are amenable to clinical and public health efforts.
Risk and Predictors of Motor‐Performance Decline in a Normally Functioning Population‐Based Sample of Elderly Subjects: The Italian Longitudinal Study on Aging
Authors: Inzitari Marco , Di Carlo Antonio , Baldereschi Marzia , Pracucci Giovanni , Maggi Stefania , Gandolfo Carlo , Bonaiuto Salvatore , Farchi Gino , Scafato Emanuele , Carbonin Pierugo , Inzitari Domenico ,   for the ILSA Working Group
Published: December 2005

OBJECTIVES: To examine risk and predictors of motor‐performance (MP) decline targeting subjects performing normally at an initial observation.

DESIGN: Cohort study.

SETTING: A subsample of the Italian Longitudinal Study on Aging (aged 65–84).

PARTICIPANTS: One thousand fifty‐two subjects (mean age±standard deviation=71±5, 69% men) with normal MP at baseline.

MEASUREMENTS: Six tests (standing up from a chair, stepping up, tandem walk, standing on one leg, walking speed, and steps turning 180°) were used to assess MP at baseline and after 3 years. Baseline characteristics were potential predictors of MP decline.

RESULTS: Of the 1,052 subjects performing normally at baseline, 166 (15.8%) had declined in MP at follow‐up. Older age, female sex, lower education, symptoms of distal symmetrical neuropathy, cognitive impairment without dementia, parkinsonism, heart failure, anemia, depressive symptoms, worse Mini‐Mental State Examination score, and lost activities of daily living and instrumental activities of daily living (IADLs) were significantly associated with MP decline in univariate comparisons. Older age (odds ratio (OR)=3.84, 95% confidence interval (CI)=2.14–6.88 comparing age classes ≥80 with 65–69), female sex (OR=1.50, 95% CI=1.03–2.20), distal symmetric neuropathy (OR=2.00, 95% CI=1.03–3.87), depressive symptoms (OR=1.85, 95% CI=1.17–2.24), and baseline IADLs (OR=1.22, 95% CI=1.08–1.37 for each lost activity) independently predicted MP decline after regression analysis.

CONCLUSION: In a population‐based cohort of elderly people with normal MP, one‐sixth declined in 3 years. Age, sex, distal symmetrical neuropathy, depressive symptoms, and baseline IADLs independently predicted this decline. Distal symmetrical neuropathy is underestimated in the clinical and epidemiological evaluation of motor decline in older people.
Factors Associated with Vaccination of Medicare Beneficiaries in Five U.S. Communities: Results from the Racial and Ethnic Adult Disparities in Immunization Initiative Survey, 2003
Authors: Winston Carla A. , Wortley Pascale M. , Lees Karen A.
Published: December 2005

OBJECTIVES: To examine vaccination in seniors in the five U.S. communities of the Racial and Ethnic Adult Disparities in Immunization Initiative.

DESIGN: Cross‐sectional telephone survey in spring 2003 using stratified sampling by ZIP code and race/ethnicity.

SETTING: New York, Texas, Wisconsin, Illinois, and Mississippi.

PARTICIPANTS: Four thousand five hundred seventy‐seven Medicare beneficiaries.

MEASUREMENTS: Outcomes were pneumococcal vaccination ever and influenza vaccination in 2002/03 and were determined according to race/ethnicity, awareness of vaccination, and provider recommendation. Survey questions also asked about future plans for vaccination, whether respondents believed they had become sick from prior influenza vaccination, and whether unvaccinated respondents would be vaccinated if a health professional recommended it.

RESULTS: Pneumococcal vaccination coverage was 70.3% for whites, 40.8% for blacks, and 53.2% for Hispanics, and the proportion reporting provider recommendation for vaccination differed significantly according to race/ethnicity. In multivariate regression, provider recommendation (risk ratio (RR)=2.32, 95% confidence intervals (CI)=2.10–2.57) and awareness of vaccination (RR=1.60, 95% CI=1.40–1.82) were associated with greater pneumococcal vaccination. Influenza vaccination coverage was 76.2% for whites, 50.7% for blacks, and 65.7% for Hispanics. A little more than half of respondents reported provider recommendation for influenza vaccination, with no differences according to race/ethnicity. Provider recommendation was associated with influenza vaccination (RR=1.31, 95% CI=1.25–1.38). More blacks and Hispanics believed they had become sick from prior influenza vaccination than whites, and this belief was associated with lower vaccination rates.

CONCLUSION: This survey details vaccination patterns in an ethnically and geographically diverse sample of seniors and identifies some differences between blacks, Hispanics, and whites that may contribute to disparities in vaccination coverage. Survey findings highlight the importance of provider vaccination recommendations.
Structural and Mechanical Behavior of Boron Nitride Fibers Derived from Poly[(Methylamino)Borazine] Precursors: Optimization of the Curing and Pyrolysis Procedures
Authors: Toutois Pascaline , Miele Philippe , Jacques Sylvain , Cornu David , Bernard Samuel
Published: December 2005

A series of boron nitride fibers were prepared by varying the tension applied on a same lot of poly(methylamino)borazine fibers during their pyrolytic conversion at 1800°C. Their microstructure/microtexture was studied by X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy investigations. Such analyses showed that ceramic fibers presented good crystallinity, but crystallites oriented along the fiber axis with fiber stress. It is most interesting that stretching was essentially effective during the pyrolysis to 1000°C, preventing fiber crimping, and decreasing the fiber diameter. Therefore, the fiber strength increased, while the fiber modulus also increased because of an improvement of the basal layer orientation along the fiber axis.
Dynamic Compressive Response of Damaged and Interlocked SiC–N Ceramics
Authors: Luo Huiyang , Chen Weinong W. , Rajendran A. M.
Published: December 2005

The dynamic compressive responses of a damaged but interlocked hot‐pressed silicon carbide were determined as a function of loading rates, damage, and confinement. A novel experimental technique based on a split Hopkinson pressure bar was used to conduct the high strain‐rate experiments. The ceramic specimen was loaded by two consecutive stress pulses to determine the responses of the intact and damaged specimen under valid testing conditions. The results show that, once critically damaged, the compressive response of the damaged ceramic was insensitive to increasing strain rates and further damage but varied with increasing lateral confinement. Under 104‐MPa confinement and damaged to three different levels, the flow stress remained at 1 GPa at strain rates of 600–1600 s−1. The flow stress reduced to 500 and 350 MPa under confinement of 56 and 26 MPa, respectively.
Enhancement of Densification and Thermal Conductivity in AlN Ceramics by Addition of Nano‐Sized Particles
Authors: Qiu Jin‐Yu , Hotta Yuji , Watari Koji , Mitsuishi Kenshi
Published: December 2005

The effect of addition of nano‐sized particles on densification and thermal conductivity of AlN ceramics was investigated. The commercially available AlN powder (∼0.9 μm) was mixed with 1.89 mass% nano‐sized AlN particles (<0.1 μm), 3.53 mass% Y2O3, and 2.0 mass% CaO as sintering aid. The mixture was fired at 1500° and 1600°C in a tungsten resistance furnace under flowing N2 atmosphere. The results showed that a fully densified specimen was obtained at the lower temperature of 1600°C by addition of nano‐sized particles. The thermal conductivity of the resulting product was 133 W/m°C. The value is much higher than the 52 W/m°C for the sample prepared without adding the nano‐sized AlN powder. This study indicates a strong potential for the use of nano‐sized particles as additives in the densification of AlN ceramics.
Fabrication of a Highly Porous Bioactive Glass–Ceramic Scaffold with a High Surface Area and Strength
Authors: Jun In‐Kook , Koh Young‐Hag , Kim Hyoun‐Ee
Published: December 2005

A bioactive glass–ceramic scaffold was fabricated, in which two interlaced three‐dimensional (3‐D) glass–ceramic walls could serve as active surfaces for the formation of a bond to bone. For its fabrication, a 3‐D graphite network acting as a template was prepared using the rapid prototyping method, and then uniformly dip coated with a melt‐derived glass slurry. The resultant sample was heat treated at 900° or 1000°C for 5 h to remove the graphite network and densify the glass–ceramic walls. The fabricated sample exhibited an ultra‐high porosity (∼95%), high compressive strength (0.2±0.03 MPa), as well as a tightly controlled pore structure. In addition, this sample had a high surface area owing to its unique structure, which was expected to enhance the rate of bone growth.
Formation of Silicon‐Doped Boron Nitride Bamboo Structures Via Pyrolysis of a Polymeric Precursor
Authors: Fan Yi , Wang Yansong , Lou Jinsong , Xu Shifeng , Zhang Ligong , An Linan , Heinrich Helge
Published: December 2005

In this paper, we report the growth of bamboo‐like silicon‐doped boron nitride nanotubes via catalyst‐assisted pyrolysis of a boron‐containing polymeric precursor. The morphologies and structures of the nanotubes were characterized using electron microscopy and Raman spectroscopy. Two types of nanotubes are observed, one from a base‐growth mode and the other from a tip‐growth mode. The type II nanotubes contain encapsulated catalytic nanoparticles at the tip of every compartment. This unique structure is a promising candidate for applications in many nanodevices.
Improvement of Water Lubricity of Titanium Nitride–Titanium Composite by Hydrophilic Silane Coupling Agent
Authors: Hibi Yuko , Sasaki Shinya
Published: December 2005

To improve the lubricity of titanium nitride–titanium (TiN–Ti) composite in water, a hydrophilic silane coupling agent was added to the water. The tribological characteristics of the TiN–Ti composite in distilled water and in aqueous solutions of the silane coupling agent ranging in concentration from 0.001 to 0.1 mol/L were investigated. The silane coupling agent effectively inhibited the formation of a thick titanium oxide layer, which degrades the water lubricity of Ti‐based materials, on the sliding surface. The lubricity of the TiN–Ti composite in the aqueous solutions of the silane coupling agent was much better than that in distilled water.
Synthesis of High Density and Transparent Forsterite Ceramics Using Nano‐Sized Precursors and Their Dielectric Properties
Authors: Sano Satoru , Saito Noriko , Matsuda Shin‐ichi , Ohashi Naoki , Haneda Hajime , Arita You , Takemoto Minoru
Published: December 2005

Forsterite (Mg2SiO4) ceramics were prepared using Mg(OH)2 and SiO2 as precursors, and the effect of powder characteristics of Mg(OH)2 on calcination and sintering was investigated. The use of highly dispersed Mg(OH)2 powder (HD powder) resulted in a lower calcination temperature. Forsterite powder of high homogeneity and small particle size prepared from the HD powder enabled synthesis of high‐density forsterite ceramics by ordinary sintering without applying external pressure. Moreover, transparent forsterite ceramics were successfully synthesized through addition of excess Mg to the precursors to compensate for Mg evaporated during the sintering process. Subsequent dielectric measurements revealed that the transparent forsterite ceramics had a very low dielectric loss (tan δ<10−4).
Hot Forging of a Textured α‐Sialon Ceramic
Authors: Carman Andrew , Pereloma Elena , Cheng Yi‐Bing
Published: December 2005

A texture was introduced into an Sm‐α‐sialon ceramic by hot pressing, such that the c‐axis was preferentially oriented normal to the pressing direction. The material was then uniaxially hot forged for up to 60 min, with the forging direction normal to the hot‐pressing direction. The texture initially reduced to a one‐dimensional preferential orientation in the direction normal to both the hot‐pressing and hot‐forging directions. Further deformation resulted in a two‐dimensional texture normal to the hot‐forging direction. The forging process was used to produce a strong one‐dimensional texture by alternating between the hot‐pressing and hot‐forging directions, thereby producing a material with significant anisotropy in its properties.
Synthesis of Mullite Powders Through a Suspension Combustion Process
Authors: Burgos‐Montes Olga , Moreno Rodrigo , Colomer María T. , Fariñas Juan C.
Published: December 2005

This work reports on the synthesis of mullite powders by a suspension combustion process. Aluminum nitrate, as a source of Al, and a colloidal silica suspension, as a source of Si, are used as reagents, and urea serves as the fuel. This colloidal suspension allows a complete mixing of the reactants, thus promoting a core‐shell reaction to produce the mullite. The powders obtained need to be treated at a high temperature to form the mullite. However, when ammonium nitrate is also added as a combustion aid, the mullite phase is directly obtained without any further treatment. A chemical reaction involving all these compounds is proposed, and the thermodynamic parameters are calculated in order to predict the temperature reached during the combustion process. The addition of ammonium nitrate reduces the temperature of the reaction by ca. 150°C. Once the conditions for the combustion reaction are optimized, the Al/Si ratio is modified in an attempt to obtain monophasic mullite.
Grain‐Oriented Bi4Ti3O12 Ferroelectric Ceramics Prepared by Magnetic Alignment
Authors: Chen Weiwu , Kinemuchi Yoshiaki , Watari Koji , Tamura Takuya , Miwa Kenji
Published: December 2005

Grain‐oriented ferroelectric ceramics are desirable for many applications, but developing a mass‐production method for such kinds of ceramics remains a significant challenge. In the current study, we report a convenient approach combining magnetic alignment and gelcasting to prepare grain‐oriented ceramics without applied pressure and templates. This method was found to be effective to prepare highly a–b plane‐oriented Bi4Ti3O12 ferroelectric ceramics and subsequently enhance the dielectric properties. We used the conventional ceramic process, i.e., solid‐state synthesis, gelcasting forming technique, and pressureless sintering except for the application of a 10 T magnetic field. Indeed, such an approach should facilitate the mass production of large and dense grain‐oriented ceramic materials.
Fiber Single‐Crystal Growth from the Melt for Optical Applications
Authors: Lebbou Kheirréddine , Perrodin Didier , Chani Valery I. , Brenier Alain , Tillement Olivier , Aloui Ouassila , Fourmigue Jean Marie , Didierjean Julien , Balembois François , Gorges Patrick
Published: December 2005

The micro‐pulling‐down technique has been applied to produce undoped and 0.1% Nd3+‐doped Y3Al5O12 garnet single‐crystal fibers with controlled diameter. The hot zone construction and fiber‐pulling conditions have been optimized. As a result, growth of transparent and homogeneous fiber crystals has been achieved. The crystals have been grown under 105 Pa (1 atm) of argon atmosphere, with the pulling rate varied in the range of 0.3–2.0 mm/min. One hundred percent of the starting melt has been normally transformed into a crystalline material, with an empty crucible ready for the next growth procedure. The as‐produced fibers demonstrate promising optical properties.
Preparation and Microstructure of Multi‐Wall Carbon Nanotubes‐Toughened Al2O3 Composite
Authors: Fan Jinpeng , Zhao Daqing , Wu Minsheng , Xu Zening , Song Jun
Published: December 2005

With multi‐wall carbon nanotubes (MWNTs) as reinforcement, a 12 vol% MWNTs/alumina (Al2O3) ceramic composite was obtained by hot pressing. A fracture toughness of 5.55±0.26 MPa·m1/2, 1.8 times that of pure Al2O3 ceramics, was achieved. Experimental results showed that the enveloping of carbon nanotubes (CNTs) with sodium dodecyl sulfate (SDS) is effective in changing the hydrophobicity of CNTs to hydrophilicity and improving the dispersion of CNTs in aqueous solution. Enveloped with SDS, CNTs can be homogeneously mixed with Al2O3 at a microscopic level by heterocoagulation. This mixing method can obviously improve the chemical compatibility between CNTs and Al2O3, which is important for enhancement of interfacial strength between them.
Phases in Ceria–Zirconia Binary Oxide (1−x)CeO2–xZrO2 Nanoparticles: The Effect of Particle Size
Authors: Zhang Feng , Chen Chih‐Hao , Hanson Jonathan C. , Robinson Richard D. , Herman Irving P. , Chan Siu‐Wai
Published: December 2005

The phases of ceria–zirconia nanoparticles observed in air are studied as a function of particle size and composition by X‐ray diffraction, transmission electron microscopy, and Raman spectroscopy. The emergence of two tetragonal phases t″ and t monotonically moves toward higher zirconia concentrations with decreasing particle size. A smaller particle size increases the solubility of zirconia in cubic ceria, while higher zirconia content in ceria stabilizes against coarsening. In particular, the cubic Ce1−xZrxO2−y is persistent and is 8% in phase amount even at 90% zirconia with 33 nm crystal size. Neither the monoclinic phase m nor the tetragonal phase t′ is observed in the present nanoparticles (<40 nm). The effectiveness of these nanoparticles as oxygen source‐and‐sink in catalytic support is largely due to the persistence of the cubic and the t″ phases.
Structural Relaxation Time of Bulk and Fiber Silica Glass as a Function of Fictive Temperature and Holding Temperature
Authors: Ryu S.‐R. , Tomozawa M.
Published: December 2005

The structural relaxation times of silica glass, both bulk glass and fiber glass at various fictive temperatures, were estimated at selected temperatures. The structural relaxation time of a glass is needed to estimate the rate of change of various glass properties in the glass transition temperature range. Traditionally, the Tool–Narayanaswamy model, in which activation energy of the relaxation time is divided into two parts, one representing the fictive temperature effect and the other representing the temperature effect, has been used. The model can explain the property changes of glass in the glass transition temperature range well when the change of the fictive temperature is small, but the model fails when the change of the fictive temperature is large, as was the case when a fiber sample was heat treated close to the glass transition temperature. The structural relaxation times estimated in the present work exhibited activation energies that varied with fictive temperature, unlike the assumption in the Tool–Narayanaswamy model. On the other hand, the relaxation time for both bulk glass and fiber glass exhibited the same temperature and fictive temperature dependence within experimental error. From these observations, one can see the source of discrepancy between the Tool–Narayanaswamy model and experimental data when the change in fictive temperature is large.
Microwave Bandgap in Multilayer Ceramic Structures
Authors: Li Bo , Zhou Ji , Li Longtu , Li Qi , Liu XiaoHan , Zi Jian
Published: December 2005

A multilayer ceramic structure with a photonic bandgap (MC‐PBG) was fabricated by a method of tape casting combined with screen printing. The MC‐PBG structure is a two‐dimensional array with either rectangular or hexagonal metal coils in a ceramic matrix. The metal coils are connected to the base metal layer in the ceramic substrate to form a monolithic body. The surface‐wave dispersion properties of these MC‐PBG structures were measured. A stop band, which is significantly influenced by the symmetrical characteristics of the inductor–capacitor (LC) arrays, was found in both the structures in the frequency range of 2.0–3.5 GHz. Because of their effective surface‐wave suppression, MC‐PBG structures can be used as high‐performance antenna substrates to enhance the broadside gain of patch antenna devices.
Microstructured Optical Fibers—Fundamentals and Applications
Authors: Lægsgaard Jesper , Bjarklev Anders
Published: December 2005

In recent years optical fibers having a complex microstructure in the transverse plane have attracted much attention from both researchers and industry. Such fibers can either guide light through total internal reflection or the photonic bandgap effect. Among the many unique applications offered by these fibers are mode guidance in air, highly flexible dispersion engineering, and the use of very heterogeneous material combinations. In this paper, we review the different types and applications of microstructured optical fibers, with particular emphasis on recent advances in the field.
Pyrochlore Phases in the System ZnO–Bi2O3–Sb2O5: I. Stoichiometries and Phase Equilibria
Authors: Miles G. C. , West A. R.
Published: December 2005

Two cubic pyrochlore phases exist in the system ZnO–Bi2O3–Sb2O5. Neither has the supposed “ideal” stoichiometry, Zn2Bi3Sb3O14. One, P1, is a solid solution phase, Zn2+xBi2.96−(x−y)Sb3.04−yO14.04+δ where 0<x<0.13(1), 0<y<0.017(2) and a=10.4285(9)−10.451(1) Å. The other, P2, is a line phase, Zn2Bi3.08Sb2.92O13.92 with a=10.462(2) Å. Subsolidus phase relations at 950°C involving phases P1 and P2 in the ZnO–Bi2O3–Sb2O5 phase diagram have been determined.
A Nonequilibrium Statistical Mechanical Model of Structural Relaxation in Glass
Authors: Mauro John C. , Varshneya Arun K.
Published: December 2005

We derive a new model of structural relaxation in glass based on nonequilibrium statistical mechanics and the Stillinger model of inherent structures. Our model follows the evolution of a system from its equilibrium liquid state through an arbitrary cooling path and allows for the computation of macroscopic properties as a function of time. Using this new model, we have numerically demonstrated for the first time the connection between the topography of a potential energy landscape in 1‐D and its corresponding fragility.
Temperature‐Dependent Optical Reflectivity of Tetragonal‐Prime Yttria‐Stabilized Zirconia
Authors: Nychka John A. , Winter Michael R. , Clarke David R. , Naganuma Tamaki , Kagawa Yutaka
Published: December 2005

The optical reflectance of dense, metastable, tetragonal‐prime zirconia plates, made by densifying electron beam physical vapor‐deposited powder, is reported as a function of temperature up to 1673 K (1400°C) over the range of 400–1500 cm−1 (6.67–25 μm). Curve fitting of the reflectance as a function of temperature was performed using two different damped oscillator models, each with three infrared (IR)‐active modes. Oscillator parameters were then used to calculate the values of the indices of refraction and absorption as a function of temperature using the classical dispersion theory. The reflectance data of tetragonal‐prime yttria‐stabilized zirconia at room temperature are qualitatively similar to that reported for the equilibrium tetragonal phase in that it can be fit with three IR‐active modes.
Structural Equilibria in Silicate Glass Melts Investigated by Raman Spectroscopy
Authors: Yano Tetsuji , Shibata Shuichi , Maehara Terutaka
Published: December 2005

Structural equilibria of alkali silicate glasses and melts are investigated based on the Qn fractions (n=number of bridging oxygen in SiO4 tetrahedron) obtained from high‐temperature Raman spectra. A mathematical treatment of the entropy of mixing, ΔSmix, of structural groups of Qn is conducted and applied to the investigation of phase transformation and phase separation. Characteristics of Qn traces and the counter‐map of ΔSmix on Qn diagram are found to possess useful information to understand their mechanisms. An extended Qn diagram is also proposed to understand the melt structure and properties for the wide composition range.
Predation of the miteHypoaspis aculeiferon the springtailFolsomia fimetariaand the influence of sex, size, starvation, and poisoning
Authors: Baatrup Erik , Bayley Mark , Axelsen Jørgen Aagaard
Published: December 2005

Short‐range predator–prey interactions among small soil‐dwelling arthropods are poorly understood. In this study, we measured the behavioural interactions between the predacious miteHypoaspis aculeiferCanestrini (Gamasida: Laelapidae) and its collembolan preyFolsomia fimetariaL. (Collembola: Isotomidae) and the influence of sex, size, starvation, and poisoning with the organophosphate dimethoate. Pairs of mite and springtail were placed in 18‐mm diameter test arenas with a plaster of Paris substrate and their behaviour were measured by a computerized vision system, which automatically detected the locomotory activity of the two animals, their encounters, and the precise time of capture and killing. Data suggest that neither the mite nor the springtail possesses near‐field sensory detection of the opponent. A Cox regression model showed that mite sex, size ratio between the predator and prey, average mite velocity, and encounter rate had a significant influence on the mite‐capture efficiency (springtail survival). FemaleH. aculeiferdemonstrated higher capture efficiency than males by catching and killing their prey after fewer encounters. Surprisingly, starvation had only a moderate effect on the mite locomotory behaviour and no influence on the capture efficiency as such. Also, springtail survival was independent of its moulting stage. Sublethal poisoning with dimethoate, on the other hand, dramatically increased the mite's capture rate, probably by impeding the evasive response of the springtail.
Plant volatiles mediate attraction to host and non‐host plant in apple fruit moth, Argyresthia conjugella
Authors: Bengtsson Marie , Jaastad Gunnhild , Knudsen Geir , Kobro Sverre , Bäckman Anna‐Carin , Pettersson Eva , Witzgall Peter
Published: December 2005

Plant volatiles mediate host finding in insect herbivores and lead to host fidelity and habitat‐specific mating, generating premating reproductive isolation and facilitating sympatric divergence. The apple fruit moth, Argyresthia conjugella Zeller (Lepidoptera: Argyresthiidae), is a particularly suitable species to study the cues and behavioural mechanisms leading to colonization of a new host: it recurrently oviposits on the non‐host plant, apple Malus domestica Borkh. (Rosaceae), where the larvae cannot complete their development. The larval host of the apple fruit moth (Lepidoptera, Argyresthiidae), is rowan Sorbus aucuparia L. (Rosaceae). Fruit setting in rowan, however, fluctuates strongly over large areas in Scandinavia. Every 2–4 years, when too few rowanberries are available for egg laying in forests, apple fruit moth females oviposit instead on apple in nearby orchards, but not on other fruits, such as pear or plum. This poses the question of which cues mediate attraction to rowan and apple, and how apple fruit moth discriminates rowan from apple. Chemical analysis and antennal recordings showed that 11 out of 15 rowan volatiles eliciting an antennal response in A. conjugella females co‐occur in rowan and apple headspace, in a different proportion. In the field, A. conjugella was attracted to several of these plant volatiles, especially to 2‐phenyl ethanol, methyl salicylate, and decanal. Addition of anethole to 2‐phenyl ethanol had a strong synergistic effect, the 1 : 1 blend is a powerful attractant for A. conjugella males and females. These results confirm that volatiles common to both plants may account for a host switch in A. conjugella from rowan to apple. Some of the most attractive compounds, including 2‐phenyl ethanol, anethole, and decanal, which have been found in several apple cultivars, were not present in the headspace of the apple cultivar, Aroma, which is also susceptible to attack by A. conjugella. This supports the idea that the odour signal from apple is suboptimal for attraction of A. conjugella, but is nonetheless sufficient for attraction, during times when rowan is not available for egg laying.
Use of micro‐CAT scans to understand cowpea seed resistance to Callosobruchus maculatus
Authors: Tarver M.R. , Shade R.E. , Tarver R.D. , Liang Y. , Krishnamurthi G. , Pittendrigh B.R. , Murdock L.L.
Published: December 2005

The cowpea bruchid, Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae: Bruchini), is a worldwide pest of stored cowpea grain [Vigna unguiculata (L.) Walp. (Leguminosae)], causing tens of millions of dollars’ worth of damage annually. One method of managing this pest involves planting cultivars whose seeds are resistant to bruchids. Despite extensive research, we still do not know the mechanism by which TVu 2027, the original resistant cowpea line, resists C. maculatus. Using micro‐CAT (computerized axial tomography) scan imaging, we visualized the feeding patterns of bruchids living and growing within cowpea seeds. We present evidence that an interior zone in TVu 2027 seeds is responsible for the high mortality and developmental delays experienced by avirulent larval bruchids. We observed that both virulent as well as avirulent bruchid strains have different feeding patterns in TVu 2027 seeds compared to susceptible seeds. It appears that the resistance factor is most concentrated in a zone in each cotyledon adjacent to the air space separating the two seed halves.
Effect of larval‐rearing density on adult life‐history traits and developmental stability of the dorsal eyespot pattern in the speckled wood butterfly,Pararge aegeria
Authors: Gibbs Melanie , Breuker Casper J.
Published: December 2005

Behavioural stresses such as crowding are thought to incur a metabolic cost to insect larvae, and fluctuating asymmetry (FA) has been shown to be a possible indicator of this stress. A study of a Madeiran population of the butterflyPararge aegeriaL. (Lepidoptera: Satyrinae) shows that larval crowding affects larval development and growth, with female larvae being more adversely affected than males. It was predicted that if larval crowding increases FA, male and femaleP. aegeriaadults may show different responses to this stress. The FA of five different wing pattern elements on the dorsal hindwings of adult male and femaleP. aegeriathat had been reared at different larval densities was measured. Crowding inP. aegeriaresulted in a trait‐specific and sex‐specific increase in FA. Although a significant correlation between FA and longevity was not observed, there was a significant correlation with egg‐laying rate. Stressed females increased their egg‐laying rate. An increased egg‐laying rate may carry a further fitness cost through the offspring of stressed females, because high egg‐laying rates are associated with a decline in oviposition site quality.
Respiration rhythms and heartbeats of diapausing Colorado potato beetles, Leptinotarsa decemlineata, at low temperatures
Authors: Vanatoa Alo , Kuusik Aare , Tartes Urmas , Metspalu Luule , Hiiesaar Külli
Published: December 2005

Discontinuous gas exchange cycles (DGCs), active muscular ventilation, microcycles of repetitive openings, and heartbeats of diapausing adult Colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), were studied at low temperatures (0, 5, and 10 °C) using an electrolytic respirometer combined with an infrared actograph. The DGC of the adult constriction‐flutter‐open type was the main respiration mode in fully quiescent beetles at temperatures from 5 to 10 °C. The CO2 bursts were actively ventilated at temperatures above 5 °C. During the flutter period, a series of microcycles appeared, but no muscular contractions associated with the microcycles were detected. We identified this respiration mode as discontinuous suction ventilation.

The hydration condition of the beetles did not influence the frequency of the gas exchange cycles, but dehydrated beetles showed significantly longer flutter periods and shorter ventilation periods than hydrated beetles. The heartbeat frequencies were influenced by both temperature and hydration status.

We conclude from the results that DGCs are used at rest in adult L. decemlineata under various environmental conditions and also at low temperatures. Our results showed that DGCs are the main respiration mode of resting adult Colorado potato beetle irrespective of its hydration state and temperature. Our method resolves O2 uptake and subsequent CO2 release in flutter and ventilation periods and shows that diffusion is replaced by convection to reduce water loss in adult beetles.
Resource quality affects restlessness in the parasitoid wasp Nasonia vitripennis
Authors: King B.H. , Ellison J.H.
Published: December 2005

Optimal foraging theory, specifically the marginal value theorem, predicts quicker leaving (shorter residence time) from poorer patches. One proximal mechanism for achieving the leaving is that exposure to lower‐quality resources may trigger increased restlessness (proportion of time in locomotion). Which aspects of host quality, if any, affect restlessness was examined in females of the parasitoid wasp Nasonia vitripennis Walker (Hymenoptera: Pteromalidae). Females were individually exposed to a single host. Restlessness was greater both during and after exposure to a host, when the host was externally damaged vs. intact. Other aspects of host quality that affected restlessness were whether the host was parasitized and whether it was dead and unsuitable for offspring development. In contrast, the host's age and stage did not affect restlessness. Increased restlessness did not make females more willing to launch themselves across an inhospitable environment using their wings.
The Retention Factor p11 Confers an Endoplasmic Reticulum‐Localization Signal to the Potassium Channel TASK‐1
Authors: Renigunta Vijay , Yuan Hebao , Zuzarte Marylou , Rinné Susanne , Koch Annett , Wischmeyer Erhard , Schlichthörl Günter , Gao Yadong , Karschin Andreas , Jacob Ralf , Schwappach Blanche , Daut Jürgen , Preisig‐Müller Regina
Published: December 2005

The interaction of the adaptor protein p11, also denoted S100A10, with the C‐terminus of the two‐pore‐domain K+ channel TASK‐1 was studied using yeast two‐hybrid analysis, glutathione S‐transferase pulldown, and co‐immunoprecipitation. We found that p11 interacts with a 40 amino‐acid region in the proximal C‐terminus of the channel. In heterologous expression systems, deletion of the p11‐interacting domain enhanced surface expression of TASK‐1. Attachment of the p11‐interacting domain to the cytosolic tail of the reporter protein CD8 caused retention/retrieval of the construct in the endoplasmic reticulum (ER). Attachment of the last 36 amino acids of p11 to CD8 also caused ER localization, which was abolished by removal or mutation of a putative retention motif (H/K)xKxxx, at the C‐terminal end of p11. Imaging of EGFP‐tagged TASK‐1 channels in COS cells suggested that wild‐type TASK‐1 was largely retained in the ER. Knockdown of p11 with siRNA enhanced trafficking of TASK‐1 to the surface membrane. Our results suggest that binding of p11 to TASK‐1 retards the surface expression of the channel, most likely by virtue of a di‐lysine retention signal at the C‐terminus of p11. Thus, the cytosolic protein p11 may represent a ‘retention factor’ that causes localization of the channel to the ER.
Postdispersal Fruit and Seed Removal by the CrabGecarcinus lateralisin a Coastal Forest in Veracruz, Mexico1
Authors: Capistrán‐Barradas Ascención , Moreno‐Casasola Patricia , Defeo Omar
Published: December 2005

In the coastal semideciduous forest of La Mancha, Veracruz (Mexico), we evaluated the removal of fallen fruits and seeds of different species by the land crabGecarcinus lateralisunder different environmental conditions (age soil of forest stand, topography, and cover). Crabs removed 67 percent of the propagules in the experiments (3106 of a total of 4608), and seeds were removed in greater quantities (61.1%) than fruits (38.9%). Fruits ofMaclura tinctoria(Moraceae) andEhretia tinifolia(Boraginacea) and seeds ofE. tinifoliawere the most affected species. Crabs removed higher quantities of fruits in old‐soil forest and in the understory than in young‐soil forest and gaps. In experiments with seeds, only for the older forest, the crabs removed more seeds in slopes and peaks than in valleys and in the understory than gaps, whereas in the young‐soil forest, the differences were not significant. Our results suggest thatG. lateralis, likeGecarcoidea natalisandGecarcinus quadratus, is an efficient propagule predator and can exert pressure in the establishment of plant species, but in La Mancha, this also depends on site conditions and identity of the species.
Effects of Small Rodent and Large Mammal Exclusion on Seedling Recruitment in Costa Rica1
Authors: DeMattia Elizabeth A. , Rathcke Beverly J. , Curran Lisa M. , Aguilar Reinaldo , Vargas Orlando
Published: December 2005

We examined whether the experimental exclusion of large mammalian and small rodent seed predators had differing effects on seedling recruitment under natural seed rain conditions. In both primary and late‐successional secondary forested areas, exclosure experiments using natural seed densities were designed to assess seedling recruitment. To assess the differences in seedling recruitment, we monitored three exclosure treatments (1.2 m radius/1.5 m height) in two forest types (primary vs. late‐successional secondary forest): (1) fenced exclosures that excluded large mammals; (2) fenced exclosures that excluded both large and small mammals; and (3) open controls. Within each exclosure treatment, we marked and identified all seedlings at the beginning of the experiment (February 2001), followed the marked seedlings' fate for a year, and then marked and identified all new seedlings after a year. Two preliminary findings were generated from these data: for some tree species, small rodents and large mammals have differential effects on seedling recruitment, and the effect of excluding mammals did not differ with habitat type (primary vs. late‐successional secondary forest). These preliminary results highlight the need to examine further how the effects of small rodent and large mammal exclusion may affect species‐specific seed predation and seedling recruitment in a variety of habitat/land use types (e.g., primary forest, late‐successional forest, and early‐successional forest).