bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphology and Infraciliature of Three Species of Metaurostylopsis (Ciliophora, Stichotrichia): M. songi n. sp., M. salina n. sp., and M. marina (Kahl 1932) from Sediments, Saline Ponds, and Coastal Waters
Authors: Lei Yanli , Choi Joong Ki , Xu Kuidong , Petz Wolfgang
Published: February 2005

Abstract. Two new urostylid ciliates, Metaurostylopsis songi n. sp. and Metaurostylopsis salina n. sp. and Metaurostylopsis marina (Kahl 1932) are investigated using live observation and protargol impregnation. These species were isolated in Korea from intertidal sediments, saline ponds, and coastal waters. Metaurostylopsis songi is in vivo about 120 μm × 25 μm, has a slenderly ellipsoidal body, colorless cortical granules in rows on ventral and dorsal body sides, about 54 macronuclear nodules, 28–47 adoral membranelles, five frontal, two or three frontoterminal and six or seven transverse cirri, and 9–12 midventral cirral pairs followed posteriorly by 1–3 single cirri. In vivo M. salina is about 60 μm × 25 μm, has a pyriform body, colorless cortical granules irregularly arranged, about 45 macronuclear nodules, 18–23 adoral membranelles, three frontal, three to five frontoterminal and two to five transverse cirri, and four or five midventral cirral pairs followed posteriorly by five to seven single cirri. Both species have three marginal cirral rows on each body side and 3 long dorsal kineties. The Korean specimens of M. marina match the Chinese population in all main features. Metaurostylopsis songi differs from M. marina by the more slender body, the number of frontal cirri (invariably five vs. four), and the arrangement of cortical granules (in rows on dorsal and ventral cortex vs. only along dorsal kineties and anterior body margin). Metaurostylopsis salina differs from its congeners by the distinctly smaller size, the pyriform body shape, the scattered cortical granules (vs. in rows), and number of frontal cirri. It differs from M. marina also by the number of midventral cirral pairs (four or five vs. seven to 11).
Paramecium aureliaRevisited
Authors: Coleman A. W.
Published: February 2005

Abstract.The speciesParamecium aureliasensu latu, containing 15 sexually isolated subspecies (syngens), is the classic example of a sibling species complex in the ciliates. Using DNA sequence comparison, it is now possible to see whether this example parallels other studied sibling species complexes. We sequenced the internal transcribed spacer (ITS) region of the nuclear ribosomal cistron for 13 of the syngens plus two otherParameciumspecies and severalTetrahymenaspp. Using available spirotrich sequences of the internal transcribed spacer 2 (ITS2), we established the RNA transcript folding pattern for ciliates. Ciliates exhibit the two highly conserved helices in their RNA transcript folding pattern in common with other eukaryotes, despite their unusual nuclear behavior and their presumed low copy number of micronuclear ribosomal repeats. Consequently, the set of 111–116 ITS2 nucleotide positions that are relatively conserved in evolution can be derived and used for comparative analysis. Mating behavior (i.e. gamete agglutination and fusion) is the character showing greatest correlation with the degree of ITS2 evolution in theP. aureliacomplex, as also found in other eukaryotes. The degree of change in the ITS2 relatively conserved sequences found among the sibling species ofP. aureliais the same degree as found among the sibling species of theDrosophila melanogaster–mauritania–sechellia–simulans–yakubaspecies complex. The relatively conserved subregion of ITS2, determined from transcript secondary structure, is a tool for identifying the level of the biological species in the absence of knowledge of sexual compatibility in both micro‐ and macro‐eukaryote species complexes.
Impact of new prostheses on the oral health related quality of life of edentulous patients
Authors: Veyrune J. L. , Tubert‐Jeannin S. , Dutheil C. , Riordan P. J.
Published: February 2005

Objective:  A study was conducted to evaluate the impact of the placement of complete dentures by using the Global Oral Health Assessment Index (GOHAI).

Background:  Oral health quality of life indicators can be used to evaluate the effects of dental treatments.

Material and methods:  The 26 participants were treated in a French University Clinic during 2002. They were randomly divided into two groups. Each group received new prostheses, but evaluation of the quality of life was made at different periods [baseline, denture placement (group 1), 6 and 12 weeks (group 2) after placement]. A questionnaire was used to collect information on patient's satisfaction with the previous and new prostheses. Nonparametric tests were used to test the relationships between patients’ satisfaction or baseline data and GOHAI variations with time as well as to compare mean values of GOHAI within each group.

Results:  At baseline, the impact of oral health problems was apparent; the mean GOHAI‐Add score was 45.8 (10.2). Six weeks after placement of the new denture, there was no difference in GOHAI scores compared with the initial assessment. An improvement in GOHAI score was observed 12 weeks after the participants received their new dentures (p < 0.05). Change in GOHAI‐Add scores was negatively correlated with the initial GOHAI‐Add score. Patients who preferred the new prosthesis enjoyed a positive change in GOHAI scores (p < 0.001). There was a relationship between participants’ satisfaction with the new dentures and change in GOHAI scores (p < 0.05).

Conclusion:  The GOHAI can be used to evaluate needs for and effect of the making of new complete dentures.
The masticatory handicap of wearing removable dentures in elderly men
Authors: Liedberg Birgitta , Stoltze Kaj , Öwall Bengt
Published: February 2005

Objective:  This study aimed at describing the masticatory handicap of wearing removable dentures measured by some masticatory tests and the intake of hard and soft foods.

Materials and methods:  The subjects were participants in a comprehensive health examination of 67–68‐year‐old men living in Malmö, Sweden. Four hundred eighty‐three men took part in a clinical oral examination which recorded the number of teeth and removable dentures. One hundred and one had complete dentures in both jaws and 131 had removable partial dentures in different combinations. Masticatory tests used almonds to record the number of stokes to the first swallow, and two‐coloured chewing gums for recording bolus kneading and shaping. A nutritionist paid a home visit to assess dietary habits including the consumption of hard and soft foods. The data could be split into groups of different tooth and denture situations which were large enough to enable statistical analysis to be carried out. The results of a regression analysis of the group with different numbers of natural teeth (NT) and no removable dentures could be used as a reference for correlation with the masticatory capacity of removable denture wearers.

Results:  Number of strokes to the first swallow revealed no masticatory limitations of wearing removable dentures, while chewing gum colour‐mixing and shaping revealed more differentiated impairments equivalent to the function of five to 16 teeth in a remaining natural dentition. Hard food intake for the removable denture groups was comparable to 17–19 NT. Soft food intake was not influenced by denture wearing. In a ranking of oral conditions, those with more than 24 NT had the highest test values for all tests, and those with complete sets of dentures the lowest except for the number of strokes to the first swallow of an almond.

Conclusion:  Removable denture wearing can be regarded as a handicap when measured with objective masticatory tests using chewing gum and the intake of hard foods. The number of chewing strokes to the first swallow of an almond and the intake of soft foods is not affected by the wearing of removable dentures.
MOLECULAR GENETIC ANALYSES OF MICROSPOROGENESIS AND MICROGAMETOGENESIS IN FLOWERING PLANTS
Authors: Ma Hong
Published: February 2005

In flowering plants, male reproductive development requires the formation of the stamen, including the differentiation of anther tissues. Within the anther, male meiosis produces microspores, which further develop into pollen grains, relying on both sporophytic and gametophytic gene functions. The mature pollen is released when the anther dehisces, allowing pollination to occur. Molecular studies have identified a large number of genes that are expressed during stamen and pollen development. Genetic analyses have demonstrated the function of some of these genes in specifying stamen identity, regulating anther cell division and differentiation, controlling male meiosis, supporting pollen development, and promoting anther dehiscence. These genes encode a variety of proteins, including transcriptional regulators, signal transduction proteins, regulators of protein degradation, and enzymes for the biosynthesis of hormones. Although much has been learned in recent decades, much more awaits to be discovered and understood; the future of the study of plant male reproduction remains bright and exciting with the ever-growing tool kits and rapidly expanding information and resources for gene function studies.
Fibroblast cell lines from young adult mice of long-lived mutant strains are resistant to multiple forms of stress
Authors: Salmon Adam B. , Murakami Shin , Bartke Andrzej , Kopchick John , Yasumura Kyoko , Miller Richard A.
Published: February 2005

Previous studies have shown that dermal fibroblast cell lines derived from young adult mice of the long-lived Snell dwarf mutant stock are resistant, in vitro, to the cytotoxic effects of H2O2, cadmium, UV light, paraquat, and heat. We show here that similar resistance profiles are seen in fibroblast cells derived from a related mutant, the Ames dwarf mouse, and that cells from growth hormone receptor-null mice are resistant to H2O2, paraquat, and UV but not to cadmium. Resistance to UV light, cadmium, and H2O2are similar in cells derived from 1-wk-old Snell dwarf or normal mice, and thus the resistance of cell lines derived from young adult donors reflects developmental processes, presumably hormone dependent, that take place in the first few months of life. The resistance of cells from Snell dwarf mice to these stresses does not reflect merely antioxidant defenses: dwarf-derived cells are also resistant to the DNA-alkylating agent methyl methanesulfonate. Furthermore, inhibitor studies show that fibroblast resistance to UV light is unaffected by the antioxidants ascorbic acid and N-acetyl-l-cysteine. These data suggest that postnatal exposure to altered levels of pituitary hormones leads to development of cellular resistance to oxidative and nonoxidative stressors, which are stable through many rounds of in vitro cell division and could contribute to the remarkable disease resistance of long-lived mutant mice.
Comparative physiology of hypoxic pulmonary hypertension: historical clues from brisket disease
Authors: Rhodes Jann
Published: February 2005

Some of the most valuable contributions to science have come about serendipitously, and, in 1913, when George Glover and Issac Newsom were commissioned by Colorado cattle ranchers to study high mountain disease, there was no way to anticipate the tremendous impact they would have on the study of high-altitude cardiopulmonary physiology. It was through the study of this agricultural malady that the correlation between chronic hypoxia, pulmonary hypertension, medial hypertrophy of the small pulmonary arteries, and right ventricular (RV) hypertrophy was recognized. The amount of vascular smooth muscle comprising the medial layer of pulmonary arteries varies significantly across species and can be used to predict the magnitude of pulmonary hypertension and RV hypertrophy elicited in response to chronic hypoxia. Within species, age and gender both significantly influence the severity of chronic hypoxic pulmonary hypertension and RV hypertrophy. However, despite all that we now know about hypoxic pulmonary hypertension, the specific mechanism(s) that differentiate the hypo- from the hyperresponder have yet to be elucidated. Adventitial fibroblast differentiation, circulating vascular progenitor cells, the presence or absence of specific vascular smooth muscle phenotypes, the upregulation or downregulation of vasoactive mediators, splice variants of oxygen-sensitive transcription factors, upregulation of growth factors, Ca2+sensitization, and/or the Rho/Rho-kinases signaling cascade could all potentially play a role in determining the extent of the vascular response to hypoxia within a species. Understanding the mechanisms that determine why some people, as well as some animals, exhibit a marked susceptibility to hypoxia is an important endeavor with far-reaching implications.
Conduction Velocity of Quiescent Muscle Fibers Decreases During Sustained Contraction
Authors: Gazzoni Marco , Camelia Federico , Farina Dario
Published: February 2005

We tested the hypothesis that conduction velocity of quiescent muscle fibers decreases during sustained contraction due to the activity of the active motor units in the muscle. Ten subjects trained for the identification of a target motor unit in the abductor pollicis brevis with feedback on surface EMG signals detected with a two-dimensional array of 61 electrodes. The subjects activated the target motor unit in two 10-s long contractions, before (contraction C1) and after (C3) a 3-min contraction (C2), all in ischemic condition. The target motor unit was not activated during C2. Eight of the 10 subjects (control group) performed a second experimental session identical to the first but with a resting period of 3 min instead of the contraction C2. Exerted force and target motor unit discharge rate were not different between the two subject groups and between C1 and C3 (mean ± SD, over C1 and C3; C2 group: 15.8 ± 10.4% maximal voluntary contractions and 13.1 ± 1.9 pps; control group: 15.6 ± 22.1% maximal voluntary contractions and 14.5 ± 1.9 pps, respectively). Muscle fiber conduction velocity of the target motor unit decreased in C3 with respect to C1 in the C2 group (3.59 ± 0.57 and 3.34 ± 0.47 m/s for C1 and C3, respectively; P < 0.05) but not in the control group (3.47 ± 0.68 and 3.46 ± 0.73 m/s). In the C2 group, the percent decrease in conduction velocity of the target motor unit between C1 and C3 (6.4 ± 7.1%) was not significantly different from the percent decrease in the average conduction velocity of the motor units active during C2 (9.6 ± 5.4%). In conclusion, the contraction-induced modifications in electrophysiological membrane properties of muscle fibers are partly independent on fiber activation.
Understanding Intentions in Social Interaction: The Role of the Anterior Paracingulate Cortex
Authors: Walter Henrik , Adenzato Mauro , Ciaramidaro Angela , Enrici Ivan , Pia Lorenzo , Bara Bruno G.
Published: February 2005

Neuroimaging studies have identified the anterior paracingulate cortex (PCC) as the key prefrontal region subserving theory of mind. We adopt an evolutionary perspective hypothesizing that, in response to the pressures of social complexity, a mechanism for manipulating information concerning social interaction has emerged in the anterior PCC. To date, neuroimaging studies have not properly distinguished between intentions of persons involved in social interactions and intentions of an isolated person. In two separate fMRI experiments, we demonstrated that the anterior PCC is not necessarily involved in the understanding of other people's intentions per se, but primarily in the understanding of the intentions of people involved in social interaction. Moreover, this brain region showed activation when a represented intention implies social interaction and therefore had not yet actually occurred. This result suggests that the anterior PCC is also involved in our ability to predict future intentional social interaction, based on an isolated agent's behavior. We conclude that distinct areas of the neural system underlying theory of mind are specialized in processing distinct classes of social stimuli.
Frontal and Temporo-Parietal Lobe Contributions to Theory of Mind: Neuropsychological Evidence from a False-Belief Task with Reduced Language and Executive Demands
Authors: Apperly Ian A. , Samson Dana , Chiavarino Claudia , Humphreys Glyn W.
Published: February 2005

A model of the functional and anatomical basis of belief reasoning is essential for understanding the relationship between belief reasoning and other cognitive processes in both normal development and pathology. Studies of brain-damaged patients can give valuable insights into the nature of belief processing but pose unique methodological problems. The current study addresses these problems by using a nonlinguistic belief-reasoning task with substantially reduced executive demands. A case series of 12 brain-damaged patients is presented. The belief-reasoning errors of four patients with damage to the prefrontal cortex appeared to arise from these patients' executive function problems. The belief-reasoning errors of three patients with damage to the temporo-parietal junction could not easily be accounted for in this way, raising the possibility that this brain region has a necessary role in representing beliefs, rather than handling the executive demands of belief-reasoning tasks. We discuss the importance of gaining empirical evidence about the scope of “theory of mind” impairments, and the important role for neuropsychological studies in this project.
Observations of Drizzle in Nocturnal Marine Stratocumulus
Authors: vanZanten M. C. , Stevens B. , Vali G. , Lenschow D. H.
Published: February 2005

In situ and radar data from the second field study of the Dynamics and Chemistry of Marine Stratocumulus (DYCOMS-II) have been used to study drizzle in stratocumulus. Measurements indicate that drizzle is prevalent. During five of seven analyzed flights precipitation was evident at the surface, and on roughly a third of the flights mean surface rates approached or exceeded 0.5 mm day−1. Additional analysis of the structure and variability of drizzle indicates that the macroscopic (flight averaged) mean drizzle rates at cloud base scale with H3/N where H is the flight-averaged cloud depth and N the flight-averaged cloud droplet number concentration. To a lesser extent flight-to-flight variability in the mean drizzle rate also scales well with differences in the 11- and 4-μm brightness temperatures, and the cloud-top effective radius. The structure of stratocumulus boundary layers with precipitation reaching the surface is also investigated, and a general picture emerges of large flight-averaged drizzle rates being manifested primarily through the emergence of intense pockets of precipitation. The characteristics of the drizzle spectrum in precipitating versus nonprecipitating regions of a particular cloud layer were mostly distinguished by the number of drizzle drops present, rather than a change in size of the median drizzle drop, or the breadth of the drizzle spectrum.
Inferring Fall Attitudes of Pristine Dendritic Crystals from Polarimetric Radar Data
Authors: Matrosov Sergey Y. , Reinking Roger F. , Djalalova Irina V.
Published: February 2005

Single pristine planar ice crystals exhibit some flutter around their preferential horizontal orientation as they fall. This study presents estimates of flutter and analyzes predominant fall attitudes of pristine dendritic crystals observed with a polarization agile Ka-band cloud radar. The observations were made in weakly precipitating winter clouds on slopes of Mt. Washington, New Hampshire. The radar is capable of measuring the linear depolarization ratios in the standard horizontal–vertical polarization basis (HLDR) and the slant 45°–135° polarization basis (SLDR). Both HLDR and SLDR depend on crystal shape. HLDR also exhibits a strong dependence on crystal orientation, while SLDR depends only weakly on orientation. The different sensitivities of SLDR and HLDR to the shape and orientation effects are interpreted to estimate the angular flutter of crystals. A simple analytical expression is derived for the standard deviation of angular flutter as a function of the HLDR to SLDR ratio assuming perfect radar system characteristics. The flutter is also assessed by matching theoretical and observed depolarization patterns as a function of the elevation of the radar’s beam. The matching procedure is generally more robust since it accounts for the actual polarization states and imperfections in the radar hardware. The depolarization approach was used to estimate flutter of falling pristine dendrites that were characterized by Reynolds numbers in a range of approximately 40–100. Using the matching approach, this flutter was found to be about 9° ± 3°, as expressed by the standard deviation of the crystal minor axes from the vertical direction. The analytical expression provides a value of flutter of about 12°, which is at the high end of the estimate obtained by the matching procedure. The difference is explained by the imperfections in the polarization states and radar hardware, so the analytical result serves as an upper bound to the more robust result from matching. The values of flutter estimated from the experimental example are comparable to estimates for planar crystals obtained in laboratory models and by individual crystal sampling.
Zonal Asymmetries, Teleconnections, and Annular Patterns in a GCM
Authors: Cash Benjamin A. , Kushner Paul J. , Vallis Geoffrey K.
Published: February 2005

The influence of zonally asymmetric boundary conditions on the leading modes of variability in a suite of atmospheric general circulation models is investigated. The set of experiments consists of nine model configurations, with varying degrees and types of zonal asymmetry in their boundary conditions. The structure of the leading EOF varies with the zonal asymmetry of the base state for each model configuration. In particular, a close relationship is found between the structure of the EOF and the model storm tracks. An approximately linear relationship is found to hold between the magnitude of the zonal asymmetry of the leading EOF and of the storm tracks in the models. It is shown that this linear relationship extends to the observations.

One-point correlation maps centered on the regions where the EOFs reach their maximum amplitude show similar structures for all configurations. These structures consist of a north–south dipole, resembling the observed structure of the North Atlantic Oscillation (NAO). They are significantly more zonally localized than the leading EOF, but do resemble one-point correlation maps and sector EOFs calculated for a simulation with zonally symmetric boundary conditions. Thus, the leading EOF for each simulation appears to represent the longitudinal distribution of zonally localized NAO-like patterns. This longitudinal distribution appears to be tied to the distribution of high-frequency eddies, as represented by the storm tracks. A detailed momentum budget for each case confirms that high-frequency eddies play a crucial role in producing the NAO-like patterns. Other dynamical processes also play an important role, but vary with the details of the simulation.
An Arctic Springtime Mixed-Phase Cloudy Boundary Layer Observed during SHEBA
Authors: Zuidema P. , Baker B. , Han Y. , Intrieri J. , Key J. , Lawson P. , Matrosov S. , Shupe M. , Stone R. , Uttal T.
Published: February 2005

The microphysical characteristics, radiative impact, and life cycle of a long-lived, surface-based mixed-layer, mixed-phase cloud with an average temperature of approximately −20°C are presented and discussed. The cloud was observed during the Surface Heat Budget of the Arctic experiment (SHEBA) from 1 to 10 May 1998. Vertically resolved properties of the liquid and ice phases are retrieved using surface-based remote sensors, utilize the adiabatic assumption for the liquid component, and are aided by and validated with aircraft measurements from 4 and 7 May. The cloud radar ice microphysical retrievals, originally developed for all-ice clouds, compare well with aircraft measurements despite the presence of much greater liquid water contents than ice water contents. The retrieved time-mean liquid cloud optical depth of 10.1 ± 7.8 far surpasses the mean ice cloud optical depth of 0.2, so that the liquid phase is primarily responsible for the cloud’s radiative (flux) impact. The ice phase, in turn, regulates the overall cloud optical depth through two mechanisms: sedimentation from a thin upper ice cloud, and a local ice production mechanism with a time scale of a few hours, thought to reflect a preferred freezing of the larger liquid drops. The liquid water paths replenish within half a day or less after their uptake by ice, attesting to strong water vapor fluxes. Deeper boundary layer depths and higher cloud optical depths coincide with large-scale rising motion at 850 hPa, but the synoptic activity is also associated with upper-level ice clouds. Interestingly, the local ice formation mechanism appears to be more active when the large-scale subsidence rate implies increased cloud-top entrainment. Strong cloud-top radiative cooling rates promote cloud longevity when the cloud is optically thick. The radiative impact of the cloud upon the surface is significant: a time-mean positive net cloud forcing of 41 W m−2 with a diurnal amplitude of ∼20 W m−2. This is primarily because a high surface reflectance (0.86) reduces the solar cooling influence. The net cloud forcing is primarily sensitive to cloud optical depth for the low-optical-depth cloudy columns and to the surface reflectance for the high-optical-depth cloudy columns. Any projected increase in the springtime cloud optical depth at this location (76°N, 165°W) is not expected to significantly alter the surface radiation budget, because clouds were almost always present, and almost 60% of the cloudy columns had optical depths >6.
Biomechanical Analysis of a Combined Double-Bundle Posterior Cruciate Ligament and Posterolateral Corner Reconstruction
Authors: Sekiya Jon K. , Haemmerle Marcus J. , Stabile Kathryne J. , Vogrin Tracy M. , Harner Christopher D.
Published: February 2005

Background

Failure to address both components of a combined posterior cruciate ligament and posterolateral corner injury has been implicated as a reason for abnormal biomechanics and inferior clinical results.

Hypothesis

Combined double-bundle posterior cruciate ligament and posterolateral corner reconstruction restores the kinematics and in situ forces of the intact knee ligaments.

Study Design

Controlled laboratory study

Methods

Ten fresh-frozen human cadaveric knees were tested using a robotic testing system through sequential cutting and reconstructing of the posterior cruciate ligament and posterolateral corner. The knees were subjected to a 134-N posterior tibial load and a 5-N.m external tibial torque at multiple flexion angles. The double-bundle posterior cruciate ligament reconstruction was performed using Achilles and semitendinosus tendons. The posterolateral corner reconstruction consisted of reattaching the popliteus tendon to its femoral origin and reconstructing the popliteofibular ligament with a gracilis tendon.

Results

Under the posterior load, the combined reconstruction reduced posterior translation to within 1.2 - 1.5 mm of the intact knee. The in situ forces in the posterior cruciate ligament grafts were significantly less than those in the native posterior cruciate ligament at all angles except full extension. Conversely, the forces in the posterolateral corner grafts were significantly higher than those in the native structures at all angles. Under the external torque with the combined reconstruction, external rotation as well as in situ forces in the posterior cruciate ligament and posterolateral corner grafts were not different from the intact knee.

Conclusions

A combined posterior cruciate ligament and posterolateral corner reconstruction can restore intact knee kinematics at time zero. In situ forces in the intact posterior cruciate ligament and posterolateral corner were not reproduced by the reconstruction; however, the posterolateral corner reconstruction reduced the loads experienced by the posterior cruciate ligament grafts.

Clinical Relevance

By addressing both structures of this combined injury, this technique restores native kinematics under the applied loads at fixed flexion angles and demonstrates load sharing among the grafts creating a potentially protective effect against early failure of the posterior cruciate ligament grafts but with increased force in the posterolateral corner construct.
Arthroscopic Cartilage Indentation and Cartilage Lesions of Anterior Cruciate Ligament-Deficient Knees
Authors: Vasara Anna I. , Jurvelin Jukka S. , Peterson Lars , Kiviranta Ilkka
Published: February 2005

Background

The anterior cruciate ligament-deficient knee is prone to osteoarthritis and meniscus lesions. Very little, however, is known about the biomechanical properties of articular cartilage in anterior cruciate ligament-deficient knees.

Purpose

To evaluate biomechanical and macroscopical cartilage changes in the knee joint with respect to the time after anterior cruciate ligament rupture.

Hypothesis

Chronic anterior cruciate ligament deficiency induces cartilage softening.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Cartilage stiffness of 50 patients undergoing anterior cruciate ligament reconstructive surgery because of symptomatic knee instability after chronic anterior cruciate ligament rupture was measured with an arthroscopic indenter device, and the number and size of cartilage lesions were evaluated.

Results

The cartilage stiffness did not correlate with time from trauma to surgery (r = 0.002, P =. 99), but the number of cartilage lesions in the knee increased when the time from the initial trauma to reconstructive surgery increased (r = 0.356, P =. 011). Indentation values measured on healthy-looking cartilage on damaged joint surfaces were lower than the values measured on healthy joint surfaces (P <. 01 on lateral femoral condyle and on tibial plateaus).

Conclusions

The number of cartilage lesions increases with increased time after initial trauma. The arthroscopic indenter device is able to detect cartilage softening as the early mechanical sign of degradation not yet visible to the eye.
Injuries among Competitive Snowboarders at the National Elite Level
Authors: Torjussen Joern , Bahr Roald
Published: February 2005

Background

Little is known about injury risk or the pattern of injuries among competitive snowboarders.

Purpose

To describe the incidence and pattern of injuries among female and male snowboard athletes at the highest national level.

Study Design

Descriptive epidemiology study

Methods

This study consists of 2 parts: prospective registration of injuries at snowboarding national cup events and the national championships during the 2002 season, as well as a retrospective interview of the participants during the national championships in March 2002. All injuries that resulted in missed participation were recorded. Exposure was recorded as the number of runs in all disciplines.

Results

In the prospective study, the competition incidence was 4.0 ± 0.7 injuries per 1000 runs (n = 32 injuries). Back (22%), knee (16%), and hand/wrist injuries (9%) were the most common. The incidence for the different disciplines was 14.2 ± 5.3 per 1000 runs for big jump, 6.1 ± 1.8 for snowboardcross, 3.1 ± 0.9 for halfpipe, and 1.9 ± 1.9 for giant slalom. The retrospective interview (n = 163 athletes, 83% response) revealed 84 acute time-loss injuries during the season; knee (16%), back (13%), head (13%), and hand/wrist injuries (12%) were the 4 most common injury types. The overall competition incidence was 3.4 ± 0.6 injuries per 1000 runs (6.6 ± 3.0 for big jump, 5.8 ± 1.7 for snowboardcross, 2.1 ± 0.7 for halfpipe, and 6.6 ± 4.7 for giant slalom). No injury was recorded in parallel slalom in either study.

Conclusion

The incidence of injuries is high among competitive snowboarders at the elite national level. The injury pattern is different from the panorama seen among less experienced athletes, with fewer wrist injuries and more knee injuries.
Opening Wedge Tibial Osteotomy: The 3-Triangle Method to Correct Axial Alignment and Tibial Slope
Authors: Noyes Frank R. , Goebel Steven X. , West John
Published: February 2005

Background

Although a change in tibial slope may occur during a medial opening wedge osteotomy, calculations have not been defined to address this problem. The authors investigated geometric factors important to correct axial alignment and tibial slope during osteotomy.

Purpose

To calculate, through 3-dimensional analysis of the proximal tibia, how the angle of the opening wedge along the anteromedial tibial cortex influences the tibial slope (sagittal plane) and valgus correction (coronal plane) during osteotomy, and to analyze the different radiographic methods reported in the literature to measure medial and lateral tibial slope. The authors postulated that differences in reported normal values of tibial slope in the sagittal plane were technique dependent.

Study Design

Descriptive laboratory study

Methods

The proximal anteromedial tibial cortex obliquity on magnetic resonance imaging was measured in 35 knees. Serial computed tomography images of the proximal tibia were digitized, allowing a series of virtual opening wedge osteotomies to be performed. Algebraic calculations defined the effect of an opening wedge osteotomy on the anteromedial tibial cortex opening wedge angle, sagittal tibial slope angle, and coronal valgus alignment.

Results

The anteromedial tibial cortex oblique angle at the medial osteotomy site was 45°± 6° and determined, along with the degrees of valgus correction, the degrees of the opening wedge angle in the oblique plane. The anterior osteotomy gap at the tibial tubercle was generally one half of the posteromedial gap to maintain the normal sagittal tibial slope. Every millimeter of gap error at the tibial tubercle resulted in approximately 2° of change in the tibial slope. The width of the buttress plate along the anteromedial tibial cortex was 2 to 3 mm less than the computed coronal valgus posteromedial osteotomy gap to achieve tibiofemoral valgus correction.

Conclusions

A series of measurements preoperatively and intraoperatively are required to obtain the desired correction of tibial slope and valgus alignment.
Biomechanics of Youth Windmill Softball Pitching
Authors: Werner Sherry L. , Guido John A. , McNeice Ryan P. , Richardson Jasper L. , Delude Neil A. , Stewart Gregory W.
Published: February 2005

Background

Limited research attention has been paid to the potentially harmful windmill softball pitch. No information is available regarding lower extremity kinetics in softball pitching.

Hypothesis

The stresses on the throwing arm of youth windmill pitchers are clinically significant and similar to those found for college softball pitchers.

Study Design

Descriptive laboratory study.

Methods

Three-dimensional, high-speed (240-Hz) video and stride foot force plate (1200 Hz) data were collected on fastballs from 53 youth softball pitchers. Kinematic parameters related to pitching mechanics and resultant kinetics on the throwing-arm elbow and shoulder joints were calculated. Kinetic parameters were compared to those reported for baseball pitchers.

Results

Elbow and shoulder joint loads were similar to those found for baseball pitchers and college softball pitchers. Shoulder distraction stress averaged 94% body weight for the youth pitchers. Stride foot ground reaction force patterns were not similar to those reported for baseball pitchers. Vertical and braking force components under the stride foot were in excess of body weight.

Conclusions

Excessive distraction stress and joint torques at the throwing-arm elbow and shoulder are similar to those found in baseball pitchers, which suggests that windmill softball pitchers are at risk for overuse injuries. Normative information regarding upper and lower extremity kinematics and kinetics for 12- to 19-year-old softball pitchers has been established.
Anterior Cruciate Ligament Injury in National Collegiate Athletic Association Basketball and Soccer: A 13-Year Review
Authors: Agel Julie , Arendt Elizabeth A. , Bershadsky Boris
Published: February 2005

Background

Female collegiate athletes have been reported to have a higher rate of anterior cruciate ligament injury compared to male collegiate athletes. This finding has spawned a branch of research focused on understanding and preventing this injury pattern.

Purpose

To determine if the trends reported in 1994 have continued.

Study Type

Descriptive epidemiology study.

Methods

The National Collegiate Athletic Association Injury Surveillance System database was reviewed for all data relating to men's and women's basketball and soccer anterior cruciate ligament injuries for 1990 to 2002.

Results

No significant difference was seen in basketball comparing frequency of contact versus noncontact injuries between men (70.1%) and women (75.7%). Male basketball players sustained 37 contact injuries and 78 noncontact injuries. Female basketball players sustained 100 contact injuries and 305 noncontact injuries. In soccer, there was a significant difference in frequency of injury for male (49.6%) and female (58.3%) athletes when comparing contact and noncontact injuries (χ2 = 4.1, P <. 05). Male soccer players sustained 72 contact injuries and 66 noncontact injuries. Female soccer players sustained 115 contact injuries and 161 noncontact injuries. The magnitude of the difference in injury rates between male and female basketball players (0.32-0.21, P =. 93) remained constant, whereas the magnitude of the difference in the rate of injuries between male and female soccer players (0.16-0.21, P =. 08) widened. Comparing injury within gender by sport, soccer players consistently sustained more anterior cruciate ligament injuries than did basketball players. The rate of anterior cruciate ligament injury for male soccer players was 0.11 compared to 0.08 for male basketball players (P =. 002). The rate of anterior cruciate ligament injury for female soccer players was 0.33 and for female basketball players was 0.29 (P =. 04). The rates for all anterior cruciate ligament injuries for women were statistically significantly higher (P <. 01) than the rates for all anterior cruciate ligament injuries for men, regardless of the sport. In soccer, the rate of all anterior cruciate ligament injuries across the 13 years for male soccer players significantly decreased (P =. 02), whereas it remained constant for female players.

Conclusions

In this sample, the rate of anterior cruciate ligament injury, regardless of mechanism of injury, continues to be significantly higher for female collegiate athletes than for male collegiate athletes in both soccer and basketball.

Clinical Relevance

Despite vast attention to the discrepancy between anterior cruciate ligament injury rates between men and women, these differences continue to exist in collegiate basketball and soccer players. Also demonstrated is that although the rate of injury for women is higher than for men, the actual rate of injury remains low and should not be a deterrent to participation in sports.
Using gaming simulation to understand deregulation dynamics
Authors: Backus George , Amlin Jeff
Published: February 2005

Emerging from a protected, regulated environment, utilities use gaming and simulation models to learn about the dynamics of deregulation. UTILITIES 21, an all-fuel, fully integrated energy model, details actual data and area dynamics. Proven both reliable and valid, the results generated from the UTILITIES 21 gaming model predicted recent energy crises as being caused by implementation of conventional decision making rather than employment of new knowledge learned from the gaming sessions. Gaming facilitators realize that learning new knowledge is insufficient. They must also teach utilities how to implement that knowledge.
The INFRASTRATEGO game: An evaluation of strategic behavior and regulatory regimes in a liberalizing electricity market
Authors: Kuit Martijn , Mayer Igor S. , de Jong Martin
Published: February 2005

The authors used the INFRASTRATEGO simulation game to examine strategic behavior in a liberalizing electricity market and the effectiveness of different regulatory regimes in dealing with this strategic behavior. The game simulates the Dutch electricity market in the years 2002 to 2006. The game was played eight times with about 400 players, both professionals and students. Two regulatory regimes defined by (a) the policy-making model and (b) the regulation by negotiation model were evaluated. The authors found several patterns of strategic behavior, such as regulatory capture, sometimes with rather disturbing effects with regard to the settlement of rates and long-term capacity planning.
Identification and characterization of circulating human transitional B cells
Authors: Sims Gary P. , Ettinger Rachel , Shirota Yuko , Yarboro Cheryl H. , Illei Gabor G. , Lipsky Peter E.
Published: February 2005

Murine B-cell development begins in bone marrow and results in the generation of immature transitional B cells that transit to the spleen to complete their maturation. It remains unclear whether the same developmental pathway takes place in humans. Using markers characteristic of human bone marrow immature B cells, we have identified a population of circulating human B cells with a phenotype most similar to mouse transitional type I (T1) B cells, although these human counterparts express CD5. These cells die rapidly in culture, and B-cell activation factor member of the tumor necrosis factor (TNF) family (BAFF) does not effect their survival regardless of B-cell receptor (BCR) stimulation. In contrast, bone marrow stromal cells or interleukin-4 (IL-4) significantly enhanced their survival. In the presence of T-cell signals provided by IL-4 or CD40 ligation, BCR stimulation can induce progression into cell cycle. Interestingly, circulating B cells that phenotypically and functionally resemble murine T2 B cells are found in cord blood and adult peripheral blood, suggesting that B-cell maturation may not be restricted to the spleen. Notably, increased proportions of T1 B cells were found in blood of patients with systemic lupus erythematosus (SLE), although bone marrow production and selection appeared to be normal.
Late mortality in survivors of autologous hematopoietic-cell transplantation: report from the Bone Marrow Transplant Survivor Study
Authors: Bhatia Smita , Robison Leslie L. , Francisco Liton , Carter Andrea , Liu Yan , Grant Marcia , Baker K. Scott , Fung Henry , Gurney James G. , McGlave Philip B. , Nademanee Auayporn , Ramsay Norma K. C. , Stein Anthony , Weisdorf Daniel J. , Forman Stephen J.
Published: February 2005

We assessed late mortality in 854 individuals who had survived 2 or more years after autologous hematopoietic cell transplantation (HCT) for hematologic malignancies. Median age at HCT was 36.5 years, and median length of follow-up was 7.6 years. Overall survival was 68.8% ± 1.8% at 10 years, and the cohort was at a 13-fold increased risk for late death (standardized mortality ratio [SMR] = 13.0) when compared with the general population. Mortality rates approached those of the general population after 10 years among patients at standard risk for relapse at HCT (SMR = 1.1) and in patients undergoing transplantation for acute myeloid leukemia (AML; SMR = 0.9). Relapse of primary disease (56%) and subsequent malignancies (25%) were leading causes of late death. Relapse-related mortality was increased among patients with Hodgkin disease (HD; relative risk [RR] = 3.6), non-Hodgkin lymphoma (NHL; RR = 2.1), and acute lymphoblastic leukemia (ALL; RR = 6.5). Total body irradiation (RR = 0.6) provided a protective effect. Nonrelapse-related mortality was increased after carmustine (RR = 2.3) and with use of peripheral blood stem cells (RR = 2.4). Survivors were more likely to report difficulty in holding jobs (RR = 9.4) and in obtaining health (RR = 7.7) or life insurance (RR = 8.4) when compared with siblings. Although mortality rates approach that of the general population after 10 years in certain subgroups, long-term survivors of autologous HCT continue to face challenges affecting their health and well-being.
Perils of paradigm: Complexity, policy design, and the Endocrine Disruptor Screening Program
Authors: Vogel Jason M
Published: February 2005

The Endocrine Disruptor Screening Program (EDSP), mandated by the United States Congress in the Food Quality Protection Act of 1996, attempts to protect public health from adverse endocrine effects of synthetic chemical compounds by establishing a new testing regime. But the complexities and uncertainties of endocrine disruption and its broader regulatory and social context all but ensure the failure of this policy. This article addresses the issues facing EDSP comprehensively and in detail, in order to move beyond the current regulatory paradigm and foster discourse on a positive role for scientists in support of EDSP's end goal: to protect public health.
An immunocompromised BALB/c mouse model for respiratory syncytial virus infection
Authors: Kong Xiaoyuan , Hellermann Gary R , Patton Geoff , Kumar Mukesh , Behera Aruna , Randall Timothy S , Zhang Jian , Lockey Richard F , Mohapatra Shyam S
Published: February 2005

Background

Respiratory syncytial virus (RSV) infection causes bronchiolitis in infants and children, which can be fatal, especially in immunocompromised patients. The BALB/c mouse, currently used as a model for studying RSV immunopathology, is semi-permissive to the virus. A mouse model that more closely mimics human RSV infection is needed. Since immunocompromised conditions increase risk of RSV infection, the possibility of enhancing RSV infection in the BALB/c mouse by pretreatment with cyclophosphamide was examined in this study. BALB/c mice were treated with cyclophosphamide (CYP) and five days later, they were infected with RSV intranasally. Pulmonary RSV titers, inflammation and airway hyperresponsiveness were measured five days after infection.

Results

CYP-treated mice show higher RSV titers in their lungs of than the untreated mice. Also, a decreased percentage of macrophages and an increased number of lymphocytes and neutrophils were present in the BAL of CYP-treated mice compared to controls. The CYP-treated group also exhibited augmented bronchoalveolar and interstitial pulmonary inflammation. The increased RSV infection in CYP-treated mice was accompanied by elevated expression of IL-10, IL-12 and IFN-γ mRNAs and proteins compared to controls. Examination of CYP-treated mice before RSV infection showed that CYP treatment significantly decreased both IFN-γ and IL-12 expression.

Conclusions

These results demonstrate that CYP-treated BALB/c mice provide a better model for studying RSV immunopathology and that decreased production of IL-12 and IFN-γ are important determinants of susceptibility to RSV infection.
Spray and combustion characteristics of dimethyl ether fuel
Authors: Lee Seang-Wock , Murata Yukata , Daisho Yasuhiro
Published: February 2005

Dimethyl ether (DME) has been recognized as an alternative fuel for better combustion and less pollutant formation than diesel, even though they have a cetane number. In this study, characteristics of DME spray were observed experimentally under various ambient conditions in a constant-volume chamber with a common-rail injection system. To understand the combustion characteristics of DME, radicals from the flame and exhaust gases were also investigated. Radicals from DME combustion were measured by a high-speed camera with stereoscope. Flame spectra were taken near 310 and 400-530 nm emitting from OH and CH or C2 radicals respectively. Flames of diesel were found to be much stronger than those of DME because of the smoke emitted from CH and C22 radicals. Moreover, NOx emission is substantially decreased without increasing in the smoke emission with a high exhaust gas recirculation (EGR) rate in DME combustion. It was confirmed from these results that DME has the potential for a low emission fuel alternative to diesel.