bluuebunny/crossref_metadata_2025 huggingface dataset:
Intra‐session repeatability of FET and FEV6 in the general population
Authors: Kainu Annette , Lindqvist Ari , Sarna Seppo , Sovijärvi Anssi
Published: March 2008

Background:  The recent American Thoracic Society/European Respiratory Society spirometry guidelines harmonized quality criteria and included assessment of forced expiratory time (FET) in bronchodilation testing when an isolated significant forced vital capacity (FVC) bronchodilation effect is observed. No consensus exists on the criteria of accepted variability of FET. Forced expiratory volume in 6 s (FEV6) has been suggested to replace FVC, especially in primary care. We examined the variability of FET and FEV6 and its determinants in the general population.

Methods:  We studied the results of acceptable flow‐volume measurements from a general population sample of 603 subjects aged 25–74 years. Intra‐class correlation coefficients (ICC), coefficients of variation (CoV), absolute and relative differences of FET, forced expiratory volume in 1 s (FEV1), FEV6 and FVC from the three acceptable curves were calculated.

Results:  FET had a mean CoV of 11·3% and ICC of 0·873. The average CoV and ICC for FEV1, FVC and FEV6 were 1·4% and 0·996, respectively. The 95th percentile of FET difference was 2·7 s. Older age was associated with slightly higher variability. Reproducibility of FET (CoV 10·6%) was better, that of both FEV6 (1·5%) and FVC (1·7%) slightly worse, in subjects with airflow limitation (FEV1/FVC < 88% predicted).

Conclusions:  Intra‐session variability of FET was eightfold compared with other flow‐volume variables. Variability of FEV1, FEV6 and FVC were similar. The findings suggest that the upper limit of intra‐session repeatability of FET is around 3·0 s. In subjects with airflow limitation FEV6 was slightly but not significantly less variable than FVC.
Hyperaemic blood‐flow velocities in systole and diastole relate to coronary risk in divergent ways
Authors: Järhult Susann J. , Hall Jan , Lind Lars
Published: March 2008

Background:  A recent study suggested blood‐flow velocity in diastole during reactive hyperaemia as a major driver of flow‐mediated vasodilation (FMD) of the brachial artery, also being related to cardiovascular risk factors. The present study aimed to investigate the relative importance of hyperaemic systolic and diastolic blood‐flow velocity in the forearm regarding both FMD and cardiovascular risk factors.

Methods:  In the Prospective Investigation of the Vasculature in Uppsala Seniors study, conducted in 1016 subjects aged 70 years, FMD, systolic and diastolic blood hyperaemic flow velocities in the brachial artery were evaluated by ultrasound.

Results:  Hyperaemic blood‐flow velocity both in systole and diastole were related to FMD (r = 0·14–0·19, P<0·0001). However, while hyperaemic systolic blood‐flow velocity was related to coronary risk (Framingham risk score) in a positive way (r = 0·08, P = 0·013), diastolic blood‐flow velocity was inversely related to coronary risk (r = −0·08, P = 0·016). Therefore, the systolic to diastolic hyperaemic blood‐flow velocity ratio was more powerful related to coronary risk (r = 0·23, P = 0·0001). In a multiple regression model, both FMD and the systolic to diastolic hyperaemic blood‐flow velocity ratio were independent predictors of coronary risk (P = 0·018 and P = 0·0001).

Conclusion:  As hyperaemic blood‐flow velocities in systole and diastole in the brachial artery were related to coronary risk in divergent ways, the ratio thereof is a promising index of vascular function providing independent information regarding coronary risk when compared with FMD.
Short‐ and Long‐Term Mortality after an Acute Illness for Elderly Whites and Blacks
Authors: Polsky Daniel , Jha Ashish K. , Lave Judith , Pauly Mark V. , Cen Liyi , Klusaritz Heather , Chen Zhen , Volpp Kevin G.
Published: March 2008

Objective. To estimate racial differences in mortality at 30 days and up to 2 years following a hospital admission for the elderly with common medical conditions.

Data Sources. The Medicare Provider Analysis and Review File and the VA Patient Treatment File from 1998 to 2002 were used to extract patients 65 or older admitted with a principal diagnosis of acute myocardial infarction, stroke, hip fracture, gastrointestinal bleeding, congestive heart failure, or pneumonia.

Study Design. A retrospective analysis of risk‐adjusted mortality after hospital admission for blacks and whites by medical condition and in different hospital settings.

Principal Findings. Black Medicare patients had consistently lower adjusted 30‐day mortality than white Medicare patients, but the initial survival advantage observed among blacks dissipated beyond 30 days and reversed by 2 years. For VA hospitalizations similar patterns were observed, but the initial survival advantage for blacks dissipated at a slower rate.

Conclusions. Racial disparities in health are more likely to be generated in the posthospital phase of the process of care delivery rather than during the hospital stay. The slower rate of increase in relative mortality among black VA patients suggests an integrated health care delivery system like the VA may attenuate racial disparities in health.
An Overview of Patient Safety Climate in the VA
Authors: Hartmann Christine W. , Rosen Amy K. , Meterko Mark , Shokeen Priti , Zhao Shibei , Singer Sara , Falwell Alyson , Gaba David M.
Published: March 2008

Objective. To assess variation in safety climate across VA hospitals nationally.

Study Setting. Data were collected from employees at 30 VA hospitals over a 6‐month period using the Patient Safety Climate in Healthcare Organizations survey.

Study Design. We sampled 100 percent of senior managers and physicians and a random 10 percent of other employees. At 10 randomly selected hospitals, we sampled an additional 100 percent of employees working in units with intrinsically higher hazards (high‐hazard units [HHUs]).

Data Collection. Data were collected using an anonymous survey design.

Principal Findings. We received 4,547 responses (49 percent response rate). The percent problematic response—lower percent reflecting higher levels of patient safety climate—ranged from 12.0–23.7 percent across hospitals (mean=17.5 percent). Differences in safety climate emerged by management level, clinician status, and workgroup. Supervisors and front‐line staff reported lower levels of safety climate than senior managers; clinician responses reflected lower levels of safety climate than those of nonclinicians; and responses of employees in HHUs reflected lower levels of safety climate than those of workers in other areas.

Conclusions. This is the first systematic study of patient safety climate in VA hospitals. Findings indicate an overall positive safety climate across the VA, but there is room for improvement.
Ownership Conversions and Nursing Home Performance
Authors: Grabowski David C. , Stevenson David G.
Published: March 2008

Objective. To examine the effects of ownership conversions on nursing home performance.

Data Source. Online Survey, Certification, and Reporting system data from 1993 to 2004, and the Minimum Data Set (MDS) facility reports from 1998 to 2004.

Study Design. Regression specification incorporating facility fixed effects, with terms to identify trends in the pre‐ and postconversion periods.

Principal Findings. The annual rate of nursing home conversions almost tripled between 1994 and 2004. Our regression results indicate converting facilities are generally different throughout the pre/postconversion years, suggesting little causal effect of ownership conversions on nursing home performance. Before and after conversion, nursing homes converting from nonprofit to for‐profit status generally exhibit deterioration in their performance, while nursing homes converting from for‐profit to nonprofit status generally exhibit improvement.

Conclusions. Policy makers have expressed concern regarding the implications of ownership conversions for nursing home performance. Our results imply that regulators and policy makers should not only monitor the outcomes of nursing home conversions, but also the targets of these conversions.
An In Vitro Comparison of Vertical Marginal Gaps of CAD/CAM Titanium and Conventional Cast Restorations
Authors: Tan Philip L. , Gratton David G. , Diaz‐Arnold Ana M. , Holmes David C.
Published: March 2008

Purpose: To determine if there was a significant difference between the vertical marginal openings of cast restorations, computer‐aided design, and computer‐aided machining restorations.

Materials and Methods: Ten working dies were created from a single master die and used to fabricate ten restorations in each of the following groups: computer‐aided design/computer‐assisted machining (CAD/CAM), WAX/CAM, and WAX/CAST. The CAD/CAM titanium restorations were fabricated using the scanning and crown design modules of the KaVo Everest system. The WAX/CAM titanium restorations were fabricated using the double scan technique with the KaVo Everest system. The WAX/CAST high noble copings were fabricated using the conventional lost wax casting technique. The restorations were seated on the master die, and high‐resolution digital photographs were made of the marginal area on all four sides. The vertical marginal opening was then measured using a calibrated digital software program. One‐way ANOVA and Tukey's post hoc tests were used to determine the presence of statistically significant differences.

Results: The vertical margin openings were CAD/CAM: 79.43 ± 25.46 μm; WAX/CAM: 73.12 ± 24.15 μm; WAX/CAST: 23.91 ± 9.80 μm. There was a statistically significant difference between the WAX/CAST group and the remaining groups.

Conclusions: There was no difference between the vertical marginal gaps of the CAD/CAM and WAX/CAM. The WAX/CAST technique resulted in smaller vertical marginal gaps than either CAD/CAM or WAX/CAM.
Effect of Zirconia Type on Its Bond Strength with Different Veneer Ceramics
Authors: Aboushelib Moustafa N. , Kleverlaan Cornelis J. , Feilzer Albert J.
Published: March 2008

Purpose: The bond strength between veneer ceramic and the zirconia framework is the weakest component in the layered structure. This bond was proven to be sensitive to the surface finish of the framework material and to the type of the veneer ceramic and its method of application. New colored zirconia frameworks were introduced to enhance the final esthetics of the layered all‐ceramic restoration. The aim of this study was to investigate the effect of zirconia type, white or colored, and its surface finish on the bond strength to two veneer ceramics.

Materials and Methods: Five commercial zirconia framework materials (Cercon white and yellow, Lava white and yellow, Procera zirconia) received either of the following surface treatments: CAD/CAM milled surface, airborne‐particle abrasion, and liner application. Two veneering ceramics were used to veneer the specimens: Noble Rondo and Ceram Express. The disc‐shaped layered specimens were cut into microbars, and microtensile bond strength (MTBS) test was conducted. Structural and chemical differences between the white and colored frameworks were evaluated using scanning electron microscopy (SEM) and energy dispersive analysis. Two‐way ANOVA and Tukey post hoc tests were used to analyze the data (p < 0.05 was considered significant).

Results: The type of zirconia framework had a significant effect on the core–veneer bond strength, which was material dependent. The bond strength to colored zirconia was significantly weaker compared to white zirconia frameworks. Different surface treatments had different effects on the core–veneer bond strength according to the zirconia material used. Although no marked chemical differences between the examined zirconia materials could be found, there were structural differences, especially between white and colored zirconia and for different zirconia frameworks of different manufacturers, which significantly affected core–veneer bond strength values.

Conclusion: The addition of coloring pigments to zirconia frameworks resulted in structural changes that require different surface treatment before veneering. To prevent delamination and chipping failures of zirconia veneered restorations, careful selection of both framework and veneer ceramic materials, in addition to proper surface treatment, are essential for maintaining good bond strength.
Pattern Analysis Based on Type, Orientation, Size, and Shape
Authors: Williams Emily Atwood , Wentz Elizabeth A.
Published: March 2008

Quantifying the pattern of geographically defined areas has proven useful in analyzing and understanding geographic processes. Pattern analyses most commonly used by geographers measure the spatial distribution of nonspatial variables at each point or in each area. The objective of this research is to develop and assess a pattern analysis for area‐class maps that considers more than the nonspatial attributes when describing a spatial pattern. We examine whether similar geographic areas—similar with respect to attribute type and several geometric properties—exhibit particular spatial patterns (e.g., clustered, random, or dispersed). The additional attributes we include are orientation, size, and shape. We refer to the method as TOSS, reflecting the Type, Orientation, Size, and Shape of areas. The goal of considering these additional attributes is to capture the geometric aspects of pattern that other approaches to pattern analysis do not. Sets or groups of similar areas are created using cluster analysis, based on a variable standardization score using the Gower coefficient of similarity. The spatial distributions for each set of geographic objects are then calculated using nearest neighbor analysis. To test the effectiveness of the TOSS method, results from pattern analysis and the TOSS method are qualitatively and quantitatively compared. The TOSS method offers a novel approach to pattern analysis.
Modeling Micro‐Spatial Employment Location Patterns: A Comparison of Count and Choice Approaches
Authors: Kim Hyungtai , Waddell Paul , Shankar Venkataraman N. , Ulfarsson Gudmundur F.
Published: March 2008

This article studies employment location patterns in the Puget Sound Region of Washington State at a micro level of geography. Traditional discrete choice modeling using multinomial logit (MNL) models may be problematic at a micro level of geography due to the high dimensionality of the set of alternative locations and the likely violations of the independence from irrelevant alternatives (IIA) assumption. Count models are free from the IIA assumption and, unlike logit models, actually benefit from large numbers of alternatives by adding degrees of freedom. This study identifies the best‐fitting count model as the zero‐inflated negative binomial (ZINB) model, because this model more effectively addresses the large number of cells with no jobs and reflects a dual process that facilitates the identification of threshold clustering effects such as those found in specialized employment centers. The estimation and prediction results of ZINB are compared with those of MNL with a random sampling of alternatives estimated on an equivalent data set. The ZINB and MNL models largely agree on major trends, with the ZINB model providing more insightful details, but with less capacity to predict large count situations.
A Structural Equation Approach to Models with Spatial Dependence
Authors: Oud Johan H. L. , Folmer Henk
Published: March 2008

We introduce the class of structural equation models (SEMs) and corresponding estimation procedures into a spatial dependence framework. SEM allows both latent and observed variables within one and the same (causal) model. Compared with models with observed variables only, this feature makes it possible to obtain a closer correspondence between theory and empirics, to explicitly account for measurement errors, and to reduce multicollinearity. We extend the standard SEM maximum likelihood estimator to allow for spatial dependence and propose easily accessible SEM software like LISREL 8 and Mx. We present an illustration based on Anselin's Columbus, OH, crime data set. Furthermore, we combine the spatial lag model with the latent multiple‐indicators–multiple‐causes model and discuss estimation of this latent spatial lag model. We present an illustration based on the Anselin crime data set again.
Cellular and molecular mechanisms that mediate basal and tumour necrosis factor‐α‐induced regulation of myosin light chain kinase gene activity
Authors: Ye Dongmei , Ma Thomas Y.
Published: March 2008

The patients with Crohn's disease (CD) have a ‘leaky gut’ manifested by an increase in intestinal epithelial tight junction (TJ) permeability. Tumour necrosis factor‐α (TNF‐α) is a proto‐typical pro‐inflammatory cytokine that plays a central role in intestinal inflammation of CD. An important pro‐inflammatory action of TNF‐α is to cause a functional opening of intestinal TJ barrier. Previous studies have shown that TNF‐α increase in TJ permeability was regulated by an increase in myosin light chain kinase (MLCK) gene activity and protein expression. The major aim of this study was to elucidate the cellular and molecular mechanisms that mediate basal and TNF‐α‐induced increase in MLCK gene activity. By progressive 5′ deletion, minimal MLCK promoter was localized between −313 to +118 on MLCK promoter. A p53 binding site located within minimal promoter region was identified as an essential determinant for basal promoter activity. A 4 bp start site and a 5 bp downstream promoter element were required for MLCK gene activity. TNF‐α‐induced increase in MLCK promoter activity was mediated by NF‐κB activation. There were eight κB binding sites on MLCK promoter. The NF‐κB1 site at +48 to +57 mediated TNF‐α‐induced increase in MLCK promoter activity. The NF‐κB2 site at −325 to −316 had a repressive role on promoter activity. The opposite effects on promoter activity were due to differences in the NF‐κB dimer type binding to the κB sites. p50/p65 dimer preferentially binds to the NF‐κB1 site and up‐regulates promoter activity; while p50/p50 dimer preferentially binds to the NF‐κB2 site and down‐regulates promoter activity. In conclusion, we have identified the minimal MLCK promoter region, essential molecular determinants and molecular mechanisms that mediate basal and TNF‐α‐induced modulation of MLCK promoter activity in Caco‐2 intestinal epithelial cells. These studies provide novel insight into the cellular and molecular mechanisms that regulate basal and TNF‐α‐induced modulation of MLCK gene activity.
A Retrospective study of root coverage procedures using an image analysis system
Authors: Kerner Stéphane , Borghetti Alain , Katsahian Sandrine , Etienne Daniel , Malet Jacques , Mora Francis , Monnet‐Corti Virginie , Glise Jean‐Marc , Bouchard Philippe
Published: March 2008

Aim: To investigate the efficacy of root coverage procedures and factors that may affect the clinical outcomes in non‐experimental patients.

Material and Methods: Two hundred and eighty‐seven root coverage surgical procedures in 215 adult patients were evaluated retrospectively. Descriptive statistics were used to determine the patient profile. Comparisons between surgeries were assessed, and the impact of different parameters on the probability of mean/complete root coverage and gingival augmentation was explored.

Results: The mean percentage of root coverage was 72.29 (± 28)%. Complete root coverage was observed in 35.56% of the defects. The difference between the surgical procedures was not significant. The mean percentage of gingival augmentation was 106.18 (± 260)%. The difference between non‐submerged grafts and the other techniques was significant (p<10−3). A significant negative impact of smoking, and maxillary teeth for both mean and complete root coverage were found. A significant positive impact of the tuberosity donor site was found for complete root coverage. Maxillary teeth and Miller's Class II and III were positive predictive factors for gingival augmentation.

Conclusions: Under non‐experimental conditions, root coverage procedures are effective. Smoking, maxillary teeth, donor site, and Miller's Classes are prognostic factors that may affect the results.
A pilot study of fluorescence diagnosis of basal cell carcinoma using a digital flash light‐based imaging system
Authors: Gambichler Thilo , Moussa Georg , Altmeyer Peter
Published: March 2008

Background/purpose: Fluorescence diagnosis (FD) is a promising method for the non‐invasive detection of tumor boundaries. We aimed to investigate the clinical utility of a flash light‐based fluorescence imaging system.

Methods: Sixteen patients with basal cell carcinomas were included in this pilot study. FD was performed using a 20% 5‐aminolevulinic acid (ALA) cream. The FD tumor area was determined 3 h after the ALA application using a digital flash light‐based fluorescence imaging system and an image analysis system. The tumor area was also assessed by means of the clinical diagnosis (CD) based on the normal colored picture. The tumors were excised following the FD procedure, but according to the clinically diagnosed lesional area.

Results: Though there was a very strong correlation between the tumor areas assessed by FD and CD, the mean tumor area that was visualized by FD was significantly smaller than the tumor area determined by CD. The mean±SD FD/CD ratio was 0.78±0.11 in total. In 81.3% of cases, complete tumor excision was achieved.

Conclusion: This pilot study indicates that the FD technology may be less sensitive than CD, and refinements of the technique along with larger systematic trials on the sensitivity and specificity of FD are required.
A case of Schamberg's disease responding dramatically to PUVA treatment
Authors: Seckin Dilek , Yazici Zuleyha , Senol Asli , Demircay Zeynep
Published: March 2008

Pigmented purpuric dermatoses are a group of chronic, recurrent disorders characterized by purpuric lesions mainly involving the lower extremities. Their etiology is unknown. Treatment options are limited and none of them have proven benefit. Phototherapy has been reported to be effective in a small number of patients in the literature. We present a case of Schamberg's disease showing a dramatic response to psoralen plus ultraviolet A therapy and discuss the current therapeutic options focusing mainly on phototherapy. We believe that phototherapy is a valuable alternative, especially for patients with long‐standing and widespread pigmented purpuric dermatitis.
Ultraviolet‐B treatment for cutaneous lichen planus: our experience with 50 patients
Authors: Pavlotsky Felix , Nathansohn Nir , Kriger Grigory , Shpiro Dorit , Trau Henri
Published: March 2008

Background: Previous small reports suggested the role of ultraviolet (UV)‐B in the management of cutaneous lichen planus.

Objective: To summarize our experience with UVB in a relatively large study group looking specifically into predictive factors for complete response and the long‐term relapse rates.

Methods: A retrospective analysis of 50 patients with generalized cutaneous lichen planus, treated by broad or narrow band UVB.

Results: Seven and 43 patients were treated by broad and narrow band UVB, respectively. Complete response was achieved in 70% and 85% of those were still in remission after a median of 34.7 months. The complete response rate and the need for higher cumulative exposure doses were not influenced by sex, age, skin type, presence of additional diseases, failure of previous treatment or disease duration.

Limitations: This is a retrospective non‐randomized analysis of a usually self‐limiting disease.

Conclusion: UVB is a safe and efficient treatment option for generalized cutaneous lichen planus.
Photoallergic contact dermatitis to Heracleum giganteum
Authors: Karimian‐Teherani Daniela , Kinaciyan Tamar , Tanew Adrian
Published: March 2008

Heracleum plants occur in numerous species worldwide and may cause phototoxic reactions due to its content of various furocoumarins. In this case report, a widespread photoallergic contact dermatitis after exposure to Heracleum giganteum (giant bear claw) is described. A photopatch test with extracts from the stem, leaves and seeds of the giant bear claw revealed a positive papulovesicular reaction that already appeared at 24 h and peaked at 72 h after irradiation with 5 J/cm2 UVA. The unirradiated controls remained negative. We conclude that in rare cases Heracleum plants may cause severe photoallergic reactions that can be verified by photopatch testing.
Purification and structural characterization of a d‐amino acid‐containing conopeptide, conomarphin, from Conus marmoreus
Authors: Han Yuhong , Huang Feijuan , Jiang Hui , Liu Li , Wang Qi , Wang Yanfang , Shao Xiaoxia , Chi Chengwu , Du Weihong , Wang Chunguang
Published: March 2008

Cone snails, a group of gastropod animals that inhabit tropical seas, are capable of producing a mixture of peptide neurotoxins, namely conotoxins, for defense and predation. Conotoxins are mainly disulfide‐rich short peptides that act on different ion channels, neurotransmitter receptors, or transporters in the nervous system. They exhibit highly diverse compositions, structures, and biological functions. In this work, a novel Cys‐free 15‐residue conopeptide from Conus marmoreus was purified and designated as conomarphin. Conomarphin is unique because of its d‐configuration Phe at the third residue from the C‐terminus, which was identified using HPLC by comparing native conomarphin fragments and the corresponding synthetic peptides cleaved by different proteases. Surprisingly, the cDNA‐encoded precursor of conomarphin was found to share the conserved signal peptide with other M‐superfamily conotoxins, clearly indicating that conomarphin should belong to the M‐superfamily, although conomarphin shares no homology with other six‐Cys‐containing M‐superfamily conotoxins. Furthermore, NMR spectroscopy experiments established that conomarphin adopts a well‐defined structure in solution, with a tight loop in the middle of the peptide and a short 310‐helix at the C‐terminus. By contrast, no loop in l‐Phe13‐conomarphin was found, which suggests that d‐Phe13 is essential for the structure of conomarphin. In conclusion, conomarphin may represent a new conotoxin family, whose biological activity remains to be identified.
Peroxiredoxins as cellular guardians in Sulfolobus solfataricus– characterization of Bcp1, Bcp3 and Bcp4
Authors: Limauro Danila , Pedone Emilia , Galdi Ilaria , Bartolucci Simonetta
Published: March 2008

Peroxiredoxins are ubiquitous enzymes that are part of the oxidative stress defense system. In the present study, we identified three peroxiredoxins [bacterioferritin comigratory protein (Bcp)1, Bcp3 and Bcp4] in the genome of the aerobic hyperthermophilic archaeon Sulfolobus solfataricus. Based on the cysteine residues conserved in the deduced aminoacidic sequence, Bcp1 and Bcp4 can be classified as 2‐Cys peroxiredoxins and Bcp3 as a 1‐Cys peroxiredoxin. A comparative study of the recombinant Bcps produced in Escherichia coli showed that these enzymes protect DNA plasmid from oxidative damage and remove both H2O2 and tert‐butyl hydroperoxide, although at different efficiencies. We observed that all of them were particularly thermostable and that peak enzymatic activity fell within the range of the growth temperature of S. solfataricus. Furthermore, we discovered an alternative Bcp reduction system whose composition differs from that of the peroxiredoxin reduction system previously characterized in the aerobic hyperthermophilic archaeon Aeropyrum pernix. Whereas the latter uses the thioredoxin/thioredoxin reductase/NADPH system, this alternative Bcp system is formed of the protein disulfide oxidoreducatase, SSO0192, the thioredoxin reductase, SSO2416, and NADPH. The role of Bcps in oxidative stress was investigated using transcriptional analysis. Different northern blot analysis responses suggested that the Bcp antioxidant system of S. solfataricus can both operate at the constitutive level, with Bcp1 and Bcp4 preventing endogenous peroxide formation, and at the inducible level, with Bcp3 and the already characterized Bcp2 protecting cells from the attack of external peroxides.
The Polydora cornuta complex (Annelida: Polychaeta) contains populations that are reproductively isolated and genetically distinct
Authors: Rice Stanley A. , Karl Stephen , Rice Katherine A.
Published: March 2008

Abstract. We have collected evidence that the nominal species, Polydora cornuta Bosc 1802, contains at least three separate species in North America. Specimens of P. cornuta were collected in California, Florida, and Maine, raised in the laboratory, and assessed for reproductive compatibility, genetic similarity, gamete characteristics, and developmental rates. Reproductive crosses between each combination of sex and population revealed variable levels of hybridization at the level of fertilization. Percent fertilization was very low for all combinations (0–7%) except for California females crossed with Florida males (42%). In all interpopulation crosses, fertilized eggs arrested in cleavage and no viable larvae were produced. All pairwise comparisons of the studied populations showed significant differences in multiple reproductive traits. Mitochondrial cytochrome oxidase subunit I DNA sequences revealed large differences between Florida and California worms with a maximum likelihood genetic distance of d=0.860, while Florida and Maine worms were d=0.806, and California and Maine d=0.156. California and New Zealand worms were very similar genetically (d=0.010). These data strongly suggest that populations of P. cornuta in North America comprise a cryptic species complex composed of at least three distinct lineages.
Morphology of anterior regeneration in two spionid polychaete species: implications for feeding efficiency
Authors: Lindsay Sara M. , Jackson Jennifer L. , Forest David L.
Published: March 2008

Abstract. In marine soft‐sediment habitats, tissue loss by infuanal invertebrates can provide significant energetic input to higher trophic levels, have substantial impacts on individual behavior, growth, and fecundity, and resulting changes in bioturbation rates can secondarily affect community dynamics. The degree to which a community is affected by such sublethal predation depends in part on whether injured individuals can regenerate and on the speed at which they do so. Previously, we demonstrated differences in the rate of anterior segment and palp regeneration by the spionid polychaetes Pygospio elegans and Dipolydora quadrilobata. The current study examined the morphology of the anterior segment and palp regeneration in these species using scanning electron microscopy (SEM) and indirect immunohistochemistry with confocal laser scanning microscopy at 3, 6, 9, and 12 d post‐ablation. Antibodies for acetylated α‐tubulin and the neural tetrapeptide FMRFamide were used to label the regenerating nervous system. SEM revealed that the morphology of anterior tissue regeneration was similar for both species, but the ciliated food groove tended to form sooner on palps in P. elegans than on those of D. quadrilobata. In both species, palp regeneration and ciliated food groove formation were faster when only palps were removed. A shortened ciliated food groove is likely to reduce particle contact and transport efficiency in suspension and deposit feeding. Regenerating palp nerves were initially visible at 3 d following ablation of palps only, but at 6 d following ablation of five anterior segments. Following ablation of anterior segments, the regenerating nervous system was largely complete by 9 d, nuchal organs were innervated by 6 d, and processes of palp sensory cells were visible at 12 d. Contact chemoreception by sensory cells on the palps may be diminished during the early stages of regeneration, but chemoreception of waterborne cues via the nuchal organ should not.
Role of diurnal rhythm of oxygen consumption in emergence from soil at night after heavy rain by earthworms
Authors: Chuang Shu‐Chun , Chen Jiun Hong
Published: March 2008

Abstract. Two species of earthworms were used to unravel why some earthworm species crawl out of the soil at night after heavy rain. Specimens of Amynthas gracilis, which show this behavior, were found to have poor tolerance to water immersion and a diurnal rhythm of oxygen consumption, using more oxygen at night than during the day. The other species, Pontoscolex corethrurus, survived longer under water and was never observed to crawl out of the soil after heavy rain; its oxygen consumption was not only lower than that of A. gracilis but also lacked a diurnal rhythm. Accordingly, we suggest that earthworms have at least two types of physical strategies to deal with water immersion and attendant oxygen depletion of the soil. The first is represented by A. gracilis; they crawl out of the waterlogged soil, especially at night when their oxygen consumption increases. The other strategy, shown by P. corethrurus, allows the earthworms to survive at a lower concentration of oxygen due to lower consumption; these worms can therefore remain longer in oxygen‐poor conditions, and never crawl out of the soil after heavy rain.
Phenotypic Plasticity of Life History Characteristics: Quantitative Analysis of Delayed Reproduction of Green Foxtail (Setaria viridis) in the Songnen Plain of China
Authors: Li Hai‐Yan , Yang Yun‐Fei
Published: March 2008

Green foxtail (Setaria viridis L.) is a common weed species in temperate regions. Research on the effect of delayed reproduction on the phenotypic plasticity and regularity of the vegetative and reproductive growth is of vital significance for understanding population regulation and control of the weed in the growing season. Green foxtail seeds were sown every 10 days from 25 June to 24 August of 2004. The growth and production metrics were measured via harvesting tufts and statistical analysis was carried out. The results showed that the reproductive tillers, seed number, seed biomass and one thousand‐seed weight of plants at the first sowing (25 June) approximately increased 28.8, 7 827.0, 1 104.0 and 12.3 times compared with that at the last sowing (24 August), respectively. Total tillers, reproductive tillers and height increased linearly as the reproductive period delayed, however, biomass increased exponentially. Quadratic equations best explained the relationships between the delayed reproductive period and seed number, inflorescence length, one thousand‐seed weight, seed biomass. Based on the quantity and quality of seed production, weeding young seedlings emerging before July can be the most effective weed‐control strategy in the Songnen Plain.
Preliminary evaluation of 1,1‐Bis (4‐ethoxyphenyl)‐2‐nitropropane as an oviposition deterrent for the Australian sheep blowfly Lucilia cuprina, and development of methods for evaluating oviposition deterrents against sheep blowfly
Authors: Browne L. Barton , Van Gerwen A. C. M.
Published: March 2008

Summary. 1,1‐Bis(4‐ethoxyphenyl)‐2‐nitropropane (GH74) was evaluated as an oviposition deterrent for the sheep blowlly Lucilia cuprina. In several test situations, flies laid only very few egg masses on fleece to which 0.5% GH74 had been applied, and which had been exposed in the field for up to 6 months. However, a significant number of egg masses were laid on the breech of severely scouring sheep when tested several weeks after application of GH74 at the same concentration. Procedures for evaluating oviposition deterrents against sheep blowfly are discussed.
Maternal antibody, vaccination and reproductive failure in dogs with parvovirus infection
Authors: GOODING G. E. , ROBINSON W. F.
Published: March 2008

Summary. The maternal antibody (MAb) titre to canine parvovirus (CPV) was determined on consecutive serums from 39 puppies in 7 litters. Vaccination with inactivated CPV was performed at a variety of ages and the response of the puppies determined. Transfer of MAb was demonstrated in 71% (5/7) of the litters and persisted for up to 10 weeks in some litters. MAb titres of >20 precluded a vaccination response by puppies. Sixty‐ one per cent (8/13) of puppies responded to vaccination when the MAb titre was <20. However, no anamestic response occurred and in some cases a decrease in antibody titre was observed following a second vaccination. During an outbreak of canine parvovirus enteritis (CPE) in the kennel, 33 puppies developed clinical signs of enteritis. Of these puppies 85% (28) had MAb titres of <80 at the onset of clinical signs. Fifty per cent (4/8) of the puppies which responded to vaccination developed CPE, whereas 100% (5/5) of those that did not respond to vaccination developed CPE.

The results indicate that MAb may persist for up to 10 weeks and puppies with MAb in the titre range >20 to <80 do not respond to vaccination but are still susceptible to infection. It is also apparent that a significant minority of puppies with MAb <20 do not respond to vaccination.

An examination of the breeding records of the kennel for the 7 year period 1973–1981 demonstrated a sudden decrease in reproductive efficiency during and subsequent to 1978. This coincided with the recognition of cases of CPV infection in the kennel. It is suggested that further investigation is required into the possible role of CPV in reproductive failure.

The authors would like to thank H. Findlay, P. Hinchliffe, G. Griffiths and S. MacPhail for technical assistance and Dr G. Wilcox and R. Flower for helpful discussion and advice.
The trichostrongyloid parasites of sheep in South Australia and their regional distribution
Authors: BEVERIDGE I. , FORD G. E.
Published: March 2008

Summary. The species of trichostrongyloid nematodes present in 376 sheep from different agricultural regions of the state of South Australia were determined.

Parasites encountered in the abomasum were Teladorsagia circumcincta, T. trifurcata, T. davtiani, Camelostrongylus mentulatus, Haemonchus contortus and Trichostrongylus axel. T. circumcincta was the species most commonly encountered, but C. mentulatus was widespread in arid areas. H. contortus was present in a small number of sheep only, mainly in southern areas.

In the small intestine, Trichostrongylus vitrinus predominated in the wetter, southern districts, and T. rugatus in dry, northern areas. T. colubriformis was common, but was rarely dominant. T. probolurus was found in one sheep. Nematodirus filicollis was restricted to wetter, southern areas, while N. spathiger and N. abnormalis were widespread and predominated in dry areas. N. helvetianus was found once. Cooperia species were uncommon; species encountered were C. oncophora, C. surnabada and C. pectinata.

Thanks are due to P. M. Bonnin, E. Moore, S. M. Fitzsimons, F. M. and R. R. Martin and M. G. O'Callaghan for excellent technical assistance, and to members of the South Australian Department of Agriculture, particularly the staff of the Northern Region, for collecting material or helping with the collection.
Considerations in the management of the pregnant patient
Authors: Livingston H. Mark , Dellinger Tracy M. , Holder Ray
Published: March 2008

Traditionally, general dentists have been reluctant to treat pregnant patients due to uncertainty of the risks that might be imposed on both the mother and the fetus. However, preventive, emergency, and routine dental procedures are all suitable during various phases of a pregnancy, with some treatment modifications and initial planning. This article will review some of the physiologic changes and oral pathology associated with pregnancy, and how these alterations affect dental care for the patient. A brief discussion concerning the risks and benefits of radiation, certain medications, and pre‐natal fluoride is also given. Additionally, an overview of possible obstetric emergencies that may arise during a general dental appointment is presented with treatment options outlined.
Serum neopterin levels in patients with non‐alcoholic steatohepatitis
Authors: Uygun Ahmet , Kadayifci Abdurrahman , Musabak Ugur , Ercin Nuri , Karslioglu Yildirim , Degertekin Bulent , Kurt Bulent , Bagci Sait
Published: March 2008

Aim:  Neopterin is a marker of cell‐mediated immunity. It also has a fundamental role in host‐defense reactions, including interactions with reactive oxygen intermediates and the promotion of local and systemic oxidative stress. The present study aimed to assess the importance of serum neopterin levels in patients with non‐alcoholic steatohepatitis (NASH).

Methods:  Thirty‐nine patients with NASH diagnosed by liver biopsy and 32 healthy adults (controls) were enrolled in the study. Serum neopterin levels were measured with an enzyme‐linked immunosorbent assay in addition to other biochemical parameters, including liver enzymes. Histopathological examinations were graded as suggested by both the necroinflammatory activity grading system and the NASH scoring system.

Results:  The mean serum neopterin levels were higher in patients with NASH compared to the controls (24.1 ± 16.4 vs 16.2 ± 9.5, P = 0.019). The histological examination of liver biopsies revealed that 34 of the patients with NASH had grade 1 steatohepatitis and only five patients had grade 2 steatohepatitis. A higher serum mean neopterin level was detected in grade 2 patients compared to grade 1 (40.6 ± 5.6 vs 21.7 ± 16.1, P = 0.014). A gradual increase was also observed in serum neopterin levels with the increase of the NASH score.

Conclusion:  The serum neopterin levels were significantly higher in patients with NASH compared to the controls, and levels showed an association with the severity of liver damage.
Disturbance Rejection Through an External Model
Authors: Tomizuka Masayoshi , Chew Kok-Kia , Yang Wei-Chi
Published: March 2008

This paper considers the use of external models for the cancellation of disturbances that can be regarded as output of stable (in the sense of Lyapunov) autonomous systems. The external model is set up outside the feedback loop so that the design of the feedback controller is accomplished without favoring particular disturbances. External model controllers can, therefore, be add-on devices to existing control systems. An application to track-following in a disk-file actuator system is presented.
Spatial Filtering Concepts in Distributed Parameter Control
Authors: Burke S. E. , Hubbard J. E.
Published: March 2008

A new method of analyzing distributed parameter control systems is presented, based upon their input/output representation in a spatially and temporally transformed frequency space. The classes of distributed systems amenable to the analysis are described in terms of their Green’s functions. The plants’ input/output relations are studied in the transformed space using the singular value decomposition to determine the system’s spatial performance. Performance is quantified in terms of generalized command following, disturbance rejection, noise rejection, controllability, and observability over spatial and temporal bandwidths, with suitable design measures presented. The analysis provides insight into the performance of sensor and actuator distributions in achieving spatial frequency performance specifications, determines spatial regimes where the response is directional, and quantifies sensor and actuator placement with respect to limitations of system and transducer spatial modelling. The analysis is shown to be applicable to discrete as well as distributed sensors and actuators, and utilizes commonly available numerical analysis techniques. An example problem is considered.
Perturbed Butterworth Pole Patterns for Tracking in the Sense of Spheres
Authors: Jayasuriya Suhada , Kee Chang-Doo
Published: March 2008

The “Quantitative Pole Placement” (QPP) identified in the context of guaranteed tracking in the sense of spheres is considered. At the center of this design philosophy is the need for directly satisfying performance specifications in uncertain, nonlinear systems. In the literature, this pole placement relies on trial and error. A systematic procedure is proposed for such pole placement when the nominal linear part of the uncertain nonlinear system is minimum phase. The approach to the problem is based on the standard LQR problem formulation. The preferred pole locations that minimize the critical operator norm needed for the success of the QPP formulation are conjectured to be a perturbed version of the Butterworth pole configuration. The results are applied to a 3 d.o.f. robotic manipulator.
Internal Combustion Engine Intake-Manifold Aspiration Dynamics
Authors: Miyano T. , Hubbard M.
Published: March 2008

A model is developed for simulating and predicting the dynamics of intake-manifolds for automotive internal combustion engines. A thermodynamic control volume approach and bond graphs are used to derive mass and energy conservation equations. Simulation outputs include time histories of pressure, temperature, mass flow, energy flow, heat flow and overall volumetric efficiency. Cylinder pressure when the intake valve closes is intensively examined because it determines the volumetric efficiency. Increases in volumetric efficiency result from increases in pressure caused by dynamic effects. Volumetric efficiency versus rpm is used to evaluate the dynamic effects of certain intake-manifold configurations. Major design parameters are the length of the intake manifold pipe, diameter of the intake manifold pipe and length of the pipe upstream of the throttle valve. Changing manifold parameters can yield improvements in volumetric efficiency at certain engine speeds but can also cause deterioration at other speeds. Shortening the length of the upstream pipe moves the volumetric efficiency peaks to higher engine speeds.
Reduced Order Design of Active Suspension Control
Authors: Salman M. A. , Lee A. Y. , Boustany N. M.
Published: March 2008

The presence of fast and slow modes in suspension systems is utilized in the design of two reduced-order active suspension control strategies. The first strategy is obtained by combining the solutions of slow and fast control sub-problems. The second strategy is based on a two-level hierarchical control design. The local level requires measurements of local fast variables, namely the unsprung mass velocities. The coordinating level relies on measurements of slow variables, namely, suspension deflections, sprung mass velocity, and mass pitch rate. Neither strategy requires tire deflection measurements. In spite of their simplified structure, simulation results indicate that their performance is comparable to that of the full-state feedback design.
Theory and Experiments on the Compliance Control of Redundant Robot Manipulators
Authors: Kazerooni H. , Bouklas K. G. , Guo J.
Published: March 2008

This work presents a control methodology for compliant motion in redundant robot manipulators. This control approach takes advantage of the redundancy in the robot’s degrees of freedom: while a maximum six degrees of freedom of the robot control the robot’s endpoint position, the remaining degrees of freedom impose an appropriate force on the environment. To verify the applicability of this control method, an active end-effector is mounted on an industrial robot to generate redundancy in the degrees of freedom. A set of experiments are described to demonstrate the use of this control method in constrained maneuvers. The stability of the robot and the environment is analyzed.
Application of Nonlinear Quadratic Stochastic Control to a Position Servomechanism
Authors: Beaman J. J. , Lin C. H.
Published: March 2008

Nonlinear Quadratic Stochastic control is applied to a position servomechanism. A method for estimating the maximum sampling time of a digital implementation of the technique is given. Additionally, a technique for improving on Gaussian statistics is shown. Non-Gaussian statistics are especially useful for the precise control of servomechanisms with granular nonlinearities such as coulomb friction and backlash.