bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Circuitry for Updating Spatial Representations. I. Behavioral Evidence for Interhemispheric Transfer in the Split-Brain Macaque
Authors: Berman Rebecca A. , Heiser Laura M. , Saunders Richard C. , Colby Carol L.
Published: May 2005

Internal representations of the sensory world must be constantly adjusted to take movements into account. In the visual system, spatial updating provides a mechanism for maintaining a coherent map of salient locations as the eyes move. Little is known, however, about the pathways that produce updated spatial representations. In the present study, we asked whether direct cortico-cortical links are required for spatial updating. We addressed this question by investigating whether the forebrain commissures—the direct path between the two cortical hemispheres—are necessary for updating visual representations from one hemifield to the other. We assessed spatial updating in two split-brain monkeys using the double-step task, which involves saccades to two sequentially appearing targets. Accurate performance requires that the representation of the second target be updated to take the first saccade into account. We made two central discoveries regarding the pathways that underlie spatial updating. First, we found that split-brain monkeys exhibited a selective initial impairment on double-step sequences that required updating across visual hemifields. Second, and most surprisingly, these impairments were neither universal nor permanent: the monkeys were ultimately able to perform the across-hemifield sequences and, in some cases, this ability emerged rapidly. These findings indicate that direct cortical links provide the main substrate for updating visual representations, but they are not the sole substrate. Rather, a unified and stable representation of visual space is supported by a redundant cortico-subcortical network with a striking capacity for reorganization.
Dynamic Circuitry for Updating Spatial Representations. II. Physiological Evidence for Interhemispheric Transfer in Area LIP of the Split-Brain Macaque
Authors: Heiser Laura M. , Berman Rebecca A. , Saunders Richard C. , Colby Carol L.
Published: May 2005

With each eye movement, a new image impinges on the retina, yet we do not notice any shift in visual perception. This perceptual stability indicates that the brain must be able to update visual representations to take our eye movements into account. Neurons in the lateral intraparietal area (LIP) update visual representations when the eyes move. The circuitry that supports these updated representations remains unknown, however. In this experiment, we asked whether the forebrain commissures are necessary for updating in area LIP when stimulus representations must be updated from one visual hemifield to the other. We addressed this question by recording from LIP neurons in split-brain monkeys during two conditions: stimulus traces were updated either across or within hemifields. Our expectation was that across-hemifield updating activity in LIP would be reduced or abolished after transection of the forebrain commissures. Our principal finding is that LIP neurons can update stimulus traces from one hemifield to the other even in the absence of the forebrain commissures. This finding provides the first evidence that representations in parietal cortex can be updated without the use of direct cortico-cortical links. The second main finding is that updating activity in LIP is modified in the split-brain monkey: across-hemifield signals are reduced in magnitude and delayed in onset compared with within-hemifield signals, which indicates that the pathways for across-hemifield updating are less effective in the absence of the forebrain commissures. Together these findings reveal a dynamic circuit that contributes to updating spatial representations.
Duration Selectivity of Neurons in the Inferior Colliculus of the Big Brown Bat: Tolerance to Changes in Sound Level
Authors: Fremouw Thane , Faure Paul A. , Casseday John H. , Covey Ellen
Published: May 2005

At and above the level of the inferior colliculus (IC), some neurons respond maximally to a limited range of sound durations, with little or no excitatory response to durations outside of this range. Such neurons have been termed “duration tuned” or “duration selective.” In this study we examined the effects of varying signal amplitude on best duration, width of tuning, and first spike latency of duration tuned neurons in the IC of the big brown bat, Eptesicus fuscus. Response areas as a function of stimulus duration and intensity took a variety of forms, including open (V-shaped), narrow and level tolerant (U-shaped), or closed (O-shaped). The majority (82%) of duration tuned neurons had narrow U-shaped or O-shaped duration response areas. Those with narrow U-shaped response areas retained their duration tuning across a broad dynamic range, ≤50 dB above threshold, whereas those with O-shaped response areas were narrowly tuned to both stimulus duration and amplitude. For about one-half (55%) of the neurons with either a U- or O-shaped response areas, best duration (BD) changed by <1 ms across the range of suprathreshold amplitudes tested. Changes in BD most often took the form of a shift to slightly shorter durations as stimulus level increased. For the majority (65%) of U- and O-shaped neurons, 50% width of duration tuning changed by <2 ms with increasing amplitude. Latency of response at BD remained stable across changes in sound level, suggesting that the relative strengths of excitatory and inhibitory inputs to duration tuned neurons remain in balance over a wide dynamic range of sound pressure levels.
Brevity of the Ca2+ Microdomain and Active Zone Geometry Prevent Ca2+-Sensor Saturation for Neurotransmitter Release
Authors: Shahrezaei Vahid , Delaney Kerry R.
Published: May 2005

The brief time course of the calcium (Ca2+) channel opening combined with the molecular-level colocalization of Ca2+ channels and synaptic vesicles in presynaptic terminals predict sub-millisecond calcium concentration ([Ca2+]) transients of ≥100 μM in the immediate vicinity of the vesicle. This [Ca2+] is much higher than some of the recent estimates for the equilibrium dissociation constant of the Ca2+ sensor(s) that control neurotransmitter release, suggesting release should be close to saturation, yet it is well known that release is highly sensitive to changes in Ca2+ influx. We show that due to the brevity of the Ca2+ influx the binding kinetics of the Ca2+ sensor rather than its equilibrium affinity determine receptor occupancy. For physiologically relevant Ca2+ currents and forward Ca2+ binding rates, the effective affinity of the Ca2+ sensor can be several-fold lower than the equilibrium affinity. Using simple models, we show redundant copies of the binding sites increase effective affinity of the Ca2+ sensor for release. Our results predict that different levels of expression of Ca2+ binding sites could account for apparent differences in Ca2+ sensor affinities between synapses. Using Monte Carlo simulations of Ca2+ dynamics with nanometer resolution, we demonstrate that these kinetic constraints combined with vesicles acting as diffusion barriers can prevent saturation of the Ca2+-sensor(s) for neurotransmitter release. We further show the random positioning of the Ca2+-sensor molecules around the vesicle can result in the emergence of two distinct populations of the vesicles with low and high release probability. These considerations allow experimental evidence for the Ca2+ channel-vesicle colocalization to be reconciled with a high equilibrium affinity for the Ca2+ sensor of the release machinery.
Angiogenesis and Pericytes in the Initiation of Ectopic Calcification
Authors: Collett G.D.M. , Canfield A.E.
Published: May 2005

Ectopic calcification of blood vessels, heart valves, and skeletal muscle is a major clinical problem. There is now good evidence that angiogenesis is associated with ectopic calcification in these tissues and that it is necessary, but not sufficient, for calcification to occur. Angiogenesis may regulate ectopic calcification in several ways. First, many angiogenic factors are now known to exert both direct and indirect effects on bone and cartilage formation. Second, cytokines released by endothelial cells can induce the differentiation of osteoprogenitor cells. Third, the new blood vessels provide oxygen and nutrients to support the growing bone. Finally, the new blood vessels can serve as a conduit for osteoprogenitor cells. These osteoprogenitor cells may be derived from the circulation or from pericytes that are present in the neovessels themselves. Indeed, there is now compelling evidence that pericytes can differentiate into osteoblasts and chondrocytes both in vitro and in vivo. Other vascular cells, including adventitial myofibroblasts, calcifying vascular cells, smooth muscle cells, and valvular interstitial cells, have also been shown to exhibit multilineage potential in vitro. Although these cells share many properties with pericytes, the precise relationship between them is not known. Furthermore, it still remains to be determined whether all or some of these cells contribute to the ectopic calcification observed in vivo. A better understanding of the underlying mechanisms that link angiogenesis, pericytes, and ectopic calcification should provide a basis for development of therapeutic strategies to treat or arrest this clinically significant condition.
Incorporating Medium-Range Numerical Weather Model Output into the Ensemble Streamflow Prediction System of the National Weather Service
Authors: Werner Kevin , Brandon David , Clark Martyn , Gangopadhyay Subhrendu
Published: May 2005

This study introduces medium-range meteorological ensemble inputs of temperature and precipitation into the Ensemble Streamflow Prediction component of the National Weather Service River Forecast System (NWSRFS). The Climate Diagnostics Center (CDC) produced a reforecast archive of model forecast runs from a dynamically frozen version of the Medium-Range Forecast (MRF) model. This archive was used to derive statistical relationships between MRF variables and historical basin-average precipitation and temperatures. The latter are used to feed the Ensemble Streamflow Prediction (ESP) component of the NWSRFS. Two sets of ESP reforecasts were produced: A control run based on historically observed temperature and precipitation and an experimental run based on MRF-derived temperature and precipitation. This study found the MRF reforecasts to be generally superior to the control reforecasts, although there were situations when the downscaled MRF output actually degraded the forecast. Forecast improvements were most pronounced during the rising limb of the hydrograph—at this time accurate temperature forecasts improve predictions of the rate of snowmelt. Further improvements in streamflow forecasts at short forecast lead times may be possible by incorporating output from high-resolution regional atmospheric models into the NWSRFS.
The Diurnal Cycle of the Summertime Atmospheric Hydrologic Cycle over the Southwestern United States
Authors: Anderson Bruce T. , Kanamaru Hideki
Published: May 2005

Diurnal variations in the climatological large-scale summertime hydrologic cycle over the southwestern United States are examined using surface and upper-air observations along with regional model output. Rainfall rates are greatest during the daytime, but the hydrologic balance that supports this rainfall changes as the day progresses. During the late morning and early afternoon, the area-averaged rainfall is balanced predominantly by evapotranspiration augmented by low-level moisture convergence; moisture from these two sources is redistributed via eddy diffusion, resulting in an overall moistening of the atmosphere and a divergence of moisture aloft. During the late afternoon, vertical redistribution via eddy diffusion weakens considerably, although precipitation continues at approximately the same rate because of drying aloft, which also supports continued large-scale divergence of moisture at these levels. This large-scale divergence aloft persists at all times of day, suggesting that for the domain as a whole, precipitation is dependent upon low-level moisture sources. At finer scales, these balances are modified principally by the presence of moisture convergence/divergence centered on the elevated regions of the domain, suggesting that local balances may be more complex than the area-average balances described here.
Evaluation of Reanalysis Soil Moisture Simulations Using Updated Chinese Soil Moisture Observations
Authors: Li Haibin , Robock Alan , Liu Suxia , Mo Xingguo , Viterbo Pedro
Published: May 2005

Using 19 yr of Chinese soil moisture data from 1981 to 1999, the authors evaluate soil moisture in three reanalysis outputs: the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40); the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalysis 1 (R-1); and the NCEP–Department of Energy (DOE) reanalysis 2 (R-2) over China. R-2 shows improved interannual variability and better seasonal patterns of soil moisture than R-1 as the result of the incorporation of observed precipitation, but not for all stations. ERA-40 produces a better mean value of soil moisture for most Chinese stations and good interannual variability. Limited observations in the spring indicate a spring soil moisture peak for most of the stations. ERA-40 generally reproduced this event, while R-1 or R-2 generally did not capture this feature, either because the soil was already saturated or the deep soil layer was too thick and damped such a response. ERA-40 and R-1 have a temporal time scale comparable to observations, but R-2 has a memory of nearly 5 months for the growing season, about twice the temporal scale of the observations. The cold season tends to prolong soil moisture memory by about 3 months for R-2 and 1 month for ERA-40. The unrealistic long temporal scale of R-2 can be attributed to the deep layer of the land surface model, which is too thick and dominates the soil moisture variability. R-1 has the same land surface scheme as R-2, but shows a temporal scale close to observations, which is actually because of soil moisture nudging to a fixed climatology. This new long time series of observed soil moisture will prove valuable for other studies of climate change, remote sensing, and model evaluation.
Dominant Modes of Moisture Flux Anomalies over North America
Authors: Dominguez Francina , Kumar Praveen
Published: May 2005

This study investigates the principal modes of seasonal moisture flux transport over North America, analyzing their possible dependence on large-scale atmospheric circulation patterns. It uses 23 yr (1979–2001) of 6-hourly data from the NCEP–NCAR reanalysis I project. Complex empirical orthogonal function (complex-EOF) analysis is implemented on the vertically integrated and seasonally averaged moisture flux, to identify the dominant modes. For every season, the characteristic spatial pattern of the two most dominant modes is compared to the geopotential height anomaly field and precipitation anomaly field using correlation analysis.

The two dominant winter modes capture the variability in the moisture flux field associated with extreme precipitation events over the western coast of the United States. The first winter mode captures 52% of the variability of the season and is related to the strong ENSO events of 1982/83 and 1997/98 (El Niño) and 1989 (La Niña). The second winter mode captures anomalous high moisture flux over the southwest related to the east Pacific teleconnection pattern.

The intense moisture transport associated with high-precipitation events in the central United States (including the 1993 flood) is captured by summer mode 1, while the second mode of the summer season captures the moisture flux variability related to the 1983 and 1988 droughts. The results show that these summer flood and drought events are characterized by very different moisture flux anomalies and are not the positive and negative phases of a given mode.

The use of complex-EOF analysis captures extreme hydrologic events as characteristic modes of interannual variability and allows a better understanding of the atmospheric circulation patterns associated with these events.
Psychological Influences on the Policy Choices of Secretaries of State and Foreign Ministers
Authors: Crichlow Scott
Published: May 2005

This article builds upon work linking the psychological characteristics of heads of government to their foreign policy preferences. The primary interest is in determining whether there is a similar link between the psychological characteristics of secretaries of state and foreign ministers and their policy preferences during international disputes. Examining the behavior of a varied set of ministers in a set of 16 decision events, such a link is found. This has important implications for those interested in understanding and predicting foreign policy, and points to the powerful personal influence exerted by these individuals. Additionally, the findings include interesting results dealing with the relative power of various cognitive and personality influences on decision-makers’ policy preferences. Cognitive influences and perceptions of the other have a particularly strong effect on the policies promoted by these decision-makers. Implications of these findings for both the political psychology and governmental politics literatures are also discussed.
Forget ‘Post-Positivist’ IR!
Authors: Rytövuori-Apunen Helena
Published: May 2005

The relationship between critical international relations (IR) and the conventional mainstream or alleged ‘orthodoxy’ needs to be better articulated. Without connecting to previous theory it cannot logically seek to introduce new ‘turns’ for disciplinary development, and intellectual movement remains isolated choreography contributing to a field that is global only in the scope of its dispersion. Proceeding from this argument, the article undertakes some of the ‘groundwork’ so often neglected in the interests of coming up with new theory and approaches or of presenting the ‘next stage’ for disciplinary discussion. A reexamination of ‘post-positivism’ as a corporate self-definition of critical IR produces an identification of the disciplinary mainstream that highlights the legacy of IR theory in theory-centred approaches and universal taxonomy, thereby providing a locus for a pragmatist turn in the study of IR. Although pragmatist approaches have already won a place in the field, the challenge remains of transcending the dichotomies of the episteme that leaves this research at the margins of the mainstream. Pragmatism is a way of inquiry opposed to dogmatism and can facilitate communication through which a more global discipline can be created. The way proposed by the author combines Deweyan ethics with C. S. Peirce’s logic of the sign.
Economic Interdependence and International Interactions
Authors: Chang Yuan-Ching
Published: May 2005

This article is an empirical analysis of the relationship between economic interdependence and international third-party interactions. When countries seek to protect their trade gains, the trade-conflict model predicts that trade reduces conflict between pairs of countries, designated the ‘actors’ and the ‘targets’. This paper extends the trade-conflict model to garner implications concerning trade and conflict interactions where third parties are involved. The theoretical propositions supported by proofs are: (1) if the actor increases trade with a third party who is a friend of the target, then the actor will reduce conflict toward the target; (2) if the actor increases trade with a third party who is a rival of the target, then the actor will increase conflict toward the target. A similar relationship is also discussed and tested for situations in which conflict increases or decreases between the actor and the third party. The empirical results of tests using a 30-country sample from the Conflict and Peace Data Bank (COPDAB) generally support the derived hypotheses. Trade increases communication and promotes peace between states. According to the implications of structural balance theory, the imbalance in a triadic relationship can be resolved by international trade. Thus, increased world trade will give effect to the maxim: ‘a friend of a friend is a friend’.
Illicit drug use and offending histories: A study of male incarcerated offenders in Australia
Authors: Makkai Toni , Payne Jason
Published: May 2005

Utilizing the self-reported offending and drug use histories of over 2000 incarcerated male prisoners from four Australian jurisdictions, offenders were categorized into different offending typologies based on lifetime criminal behaviour. Eight different crime types were developed and offenders’ reported use of four drugs - cannabis, amphetamines, heroin and cocaine - was examined. The analysis found that the type and level of illicit drug use varied across the different types of offenders. Of those who had used drugs, the rates of poly-drug use were high. Furthermore, most drug using offenders, regardless of crime type, were on average more likely to commit minor offending prior to the onset of illicit drug use. The extent to which offenders attributed drug use to their criminal careers also varied. This article highlights that interventions aimed at drug use alone will have only a limited impact on reducing the likelihood of re-offending.
Mental health training needs amongst staff of Probation Approved Premises: A comparison with mental health hostel staff in the voluntary sector
Authors: Hatfield Barbara , Ryan Tony , Pickering Laura , Downing Brigid , Crofts Roger
Published: May 2005

The recognition of significant levels of mental health need amongst people in contact with the criminal justice system has led to many new areas of partnership working between mental health and the criminal justice system. The training needs of staff within the criminal justice system in England and Wales is recognized as an important area for service development and has to date been largely unexplored. This article examines many of the issues as identified when comparing the mental health training needs and experiences of staff working in two forms of residential service - Probation Approved Premises and voluntary sector mental health services.
Suspended sentences in Spain: Decarceration and recidivism
Authors: Cid Josép
Published: May 2005

The suspended sentence, along with the fine, is the most commonly used alternative to prison in Spain. This sentence is generally regarded as a good sanction because it avoids the personal and financial costs of prison for occasional offenders which are not in need of rehabilitation. The main aim of this article is to present data and empirical research about the effectiveness of the suspended sentence with respect to its two main goals: reducing the use of prison and preventing offenders from re-offending. The data appear to suggest that this is an effective sentence in these terms, but the article also raises questions about the need to replace suspended sentences with more rehabilitative orders in some special cases.
Developing humane criminal justice systems in democratic societies: An update from Hungary
Authors: Gönczöl Katalin
Published: May 2005

This article examines the changes and development of penal policy and community sentencing in Hungary. As a new criminal justice system emerges, including the recently reformed probation service in Hungary, this article argues that democratic societies must hold a careful balance between controlling the behaviour of its citizens, whilst crucially also ensuring their freedom, dignity and human rights. From the position of someone who has been closely involved with these developments and transitions in Hungary, the author questions whether the balance that has been achieved in ‘advanced’ democracies, such as the USA, given the excessive use of imprisonment and punitive sentencing. She argues that an alternative model is in the best interests of all - one that stigmatizes the offence but not the offender.
The Effects of Low-Intensity Ultrasound on Medial Collateral Ligament Healing in the Rabbit Model
Authors: Sparrow Karen J. , Finucane Sheryl D. , Owen John R. , Wayne Jennifer S.
Published: May 2005

Background

Ruptured medial collateral ligaments are capable of healing over time, but biomechanical and biochemical properties remain inferior to normal tissue. Low-intensity ultrasound may improve healing.

Hypothesis

Medial collateral ligaments treated with ultrasound will demonstrate superior healing.

Study Design

Controlled laboratory study.

Methods

Twenty-one late-adolescent male rabbits underwent bilateral ligament transection. One ligament from each rabbit received ultrasound treatment every other day for 6 total treatments. Contralateral ligaments received sham treatments. After 3 or 6 weeks, ligaments were evaluated biomechanically and assayed for collagen concentration and the relative proportions of types I and III collagen.

Results

Areas of sonicated specimens were significantly larger (10.6% ± 4.90%) at 6 weeks. Ultimate load (39.5% ± 17.0%), ultimate displacement (24.5% ± 8.0%), and energy absorption (69.1% ± 22.0%) were significantly higher for sonicated specimens at 6 weeks. No significant biomechanical differences were observed at 3 weeks. The relative proportion of type I collagen was significantly higher in sonicated ligaments at 3 weeks (8.61% ± 4.0%) and 6 weeks (6.91% ± 3.0%). No significant differences in collagen concentration were observed at either 3 or 6 weeks.

Conclusion

Subtle improvement with ultrasound treatment may be apparent by 3 weeks after injury, suggested by increased proportion of type I collagen. Ultrasound appears to improve some structural properties and to modestly increase scar cross-sectional area and type I collagen present at 6 weeks after injury in this model.

Clinical Relevance

Ultrasound treatments after ligament injury may facilitate earlier return to activities and decrease risk of reinjury.
Effects of Radiofrequency Energy on Human Articular Cartilage
Authors: Caffey Sean , McPherson Edward , Moore Brian , Hedman Thomas , Vangsness C. Thomas
Published: May 2005

Background

Previous radiofrequency work has not rigidly controlled energy application to the articular cartilage, giving uncertain results published to date.

Hypothesis

At minimal settings, radiofrequency probes cause cell death in measurable areas when applied to human articular cartilage.

Study Design

Controlled laboratory study.

Methods

Simulating operating room conditions, 5 commercially available radiofrequency probes were attached to a customized jig to standardize a minimal contact pressure of each probe tip to 2.0 g. Keeping all variables the same, probes were placed on specific points of fresh grade II human cartilage with treatment times of 1 and 3 seconds at the manufacturer's recommended settings. Grade III cartilage was also tested with a treatment time of 3 seconds, and grade II cartilage was studied with the probe held 1 mm off the cartilage surface. Cartilage was blindly analyzed by confocal microscopy using a live/dead cell viability assay to determine the extent of cell death.

Results

Radiofrequency probes produced significant cellular death in the form of a half-circle into the cartilage to variable depths. For treatment times of 1 and 3 seconds, cell death measurements ranged from 404 to 539 μm and 1034 to 1283 μm, respectively. One probe failed to show any effect, with minimal evidence of cell death or cartilage smoothing. When probes were kept a 1.0-mm distance above the cartilage, no cell death or cartilage smoothing was noted. Radiofrequency treatment of grade III cartilage penetrated to the subchondral bone. There was no statistically significant difference between the damage caused by monopolar and bipolar probes when tested under these rigidly controlled conditions.

Conclusion

These results showed significant cellular death at these minimal conditions to the underlying chondrocytes with radiofrequency probes. Surgeons using this technology need to be aware of the power and dangerous potential these probes can have on articular cartilage.
Neuromuscular and Biomechanical Adaptations of Patients with Isolated Deficiency of the Posterior Cruciate Ligament
Authors: Fontboté Cristián A. , Sell Timothy C. , Laudner Kevin G. , Haemmerle Marcus , Allen Christina R. , Margheritini Fabrizio , Lephart Scott M. , Harner Christopher D.
Published: May 2005

Background

Functional adaptations of patients with posterior cruciate ligament deficiency (grade II) are largely unknown despite increased recognition of this injury.

Hypothesis

Posterior cruciate ligament-deficient subjects (grade II, 6- to 10-mm bilateral difference in posterior translation) will present with neuromuscular and biomechanical adaptations to overcome significant mechanical instability during gait and drop-landing tasks.

Study Design

Controlled laboratory study.

Methods

Bilateral comparisons were made among 10 posterior cruciate ligament-deficient subjects using radiographic, instrumented laxity, and range of motion examinations. Biomechanical and neuromuscular characteristics of the involved limb of the posterior cruciate ligament-deficient subjects were compared to their uninvolved limb and to 10 matched control subjects performing gait and drop-landing tasks.

Results

Radiographic (15.3 ± 2.9 to 5.6 ± 3.7 mm; P =. 008) and instrumented laxity (6.3 ± 2.0 to 1.4 ± 0.5 mm; P <. 001) examinations demonstrated significantly greater posterior displacement of the involved knee within the posterior cruciate ligament-deficient group. The posterior cruciate ligament-deficient group had a significantly decreased maximum knee valgus moment and greater vertical ground reaction force at midstance during gait compared to the control group. During vertical landings, the posterior cruciate ligament-deficient group demonstrated a significantly decreased vertical ground reaction force loading rate. All other analyses reported no significant differences within or between groups.

Conclusion

Posterior cruciate ligament-deficient subjects demonstrate minimal biomechanical and neuromuscular differences despite significant clinical laxity.

Clinical Relevance

The findings of this study indicate that individuals with grade II posterior cruciate ligament injuries are able to perform gait and drop-landing activities similar to a control group without surgical intervention.
Long-term Failure of Thermal Shrinkage for Laxity of the Anterior Cruciate Ligament
Authors: Halbrecht Jeffrey
Published: May 2005

Background

Appropriate treatment for anterior cruciate ligament laxity, owing to partial tears of the native ligament or lax reconstruction, is unclear. Studies suggest that a significant percentage of these untreated tears may progress to complete tears or the patient may develop additional injuries to the meniscus or articular cartilage. Shrinkage of the ligament or graft using thermal energy has been proposed as a solution for this problem.

Purpose

To evaluate the long-term results using thermal energy to shrink laxity of the anterior cruciate ligament.

Study Design

Case series; Level of evidence, 4.

Methods

Nineteen patients with partial tears of the anterior cruciate ligament (n = 14) or stretched anterior cruciate ligament grafts (n = 5) underwent thermal shrinkage treatment. Fourteen were available for follow-up at 1 and 5 years. At 1 year, there were 12 partial tears and 2 grafts available for evaluation. At 5 years, there were 10 partial tears and 4 grafts. Preoperative, postoperative, and intraoperative stability testing was performed using the KT-1000 arthrometer. Clinical results were evaluated using the Cincinnati and Lysholm scoring systems.

Results

Intraoperative shrinkage averaged 2.12 mm (17%, P <. 0001). At 1 year, 12 of the 14 patients remained stable (86%) with a negative Lachman test result and mean KT-1000 arthrometer maximum side-to-side score of 1.29 mm (P <. 001). The 2 failed shrinkages were partial tears of the native anterior cruciate ligament. For these 12 patients, Cincinnati scores improved from 53 to 89 (P <. 0001), and Lysholm scores improved from 55 to 89 (P <. 0003). At 5-year follow-up, 11 of 13 patients had gone on to complete failure (85%, P <. 002; 8/9 partial tears and 3/4 grafts).

Conclusion

Thermal shrinkage provides short-term benefit in the treatment of anterior cruciate ligament laxity but leads to catastrophic failure in the majority of patients at long-term follow-up. We can no longer recommend this procedure for the treatment of anterior cruciate ligament laxity.
Early Screw Fixation versus Casting in the Treatment of Acute Jones Fractures
Authors: Mologne Timothy S. , Lundeen Jeffrey M. , Clapper Mark F. , O’Brien Thomas J.
Published: May 2005

Background

There is considerable variability in the literature concerning the optimal treatment of acute Jones fractures.

Hypothesis

Early surgical fixation of acute Jones fractures will result in shorter times to union and return to athletics compared with cast treatment.

Study Design

Randomized controlled clinical trial; Level of evidence, 1.

Methods

Eighteen patients were randomized to cast treatment, and 19 patients were randomized to screw fixation. Success of treatment and the times to union and return to sports were calculated for each patient.

Results

Mean follow-up was 25.3 months (range, 15-42 months). Eight of 18 (44%) in the cast group were considered treatment failures: 5 nonunions, 1 delayed union, and 2 refractures. One of 19 patients in the surgery group was considered a treatment failure. For the surgery group, the median times to union and return to sports were 7.5 and 8.0 weeks, respectively. For the cast group, the median times were 14.5 and 15.0 weeks, respectively. The Mann-Whitney test showed a statistically significant difference between the groups in both parameters, with P <. 001.

Conclusion

There is a high incidence (44%) of failure after cast treatment of acute Jones fractures. Early screw fixation results in quicker times to union and return to sports compared with cast treatment.
Chemically Functionalized Clay-Epoxy Nanocomposites: Vernonia Oil-based Surfactant
Authors: Balakrishnan S. , Raghavan D.
Published: May 2005

Reactive surfactant C19 hydroxyl amine hydrochloride and octadecyl amine hydrochloride are used to functionalize Na clay. The resultant clay is used to formulate an epoxy nanocomposite by the reactive diluent approach. The clay platelet morphology in the nanocomposites is characterized by X-ray diffraction (XRD) and transmission electron microscopy. Addition of a comonomer glycidyl methacrylate and high-intensity ultrasonic mixing produces an epoxy nanocomposite with improved degree of clay platelet exfoliation. At an organoclay loading of only 3.5 wt%, the modulus improved by 25% in a partially reactive organoclay epoxy system, while the modulus improved by 15% in nonreactive organoclay epoxy system compared to that of epoxy resin.
Transient Response Analysis of Bimodulus Anisotropic Laminated Composite Plates
Authors: Patel B. P. , Gupta S. S. , Joshi M. , Ganapathi M.
Published: May 2005

The transient flexural response analysis of anisotropic laminated composite plates of bimodulus materials subjected to mechanical loading is carried out in this study. The formulation is based on the higher-order theory that accounts for the transverse shear and transverse normal deformations, and incorporates the nonlinear through-the-thickness approximations of the in-plane and transverse displacements. The governing equations obtained using the Lagrange’s equations of motion are solved through the finite element approach. The results obtained are compared with the first-order shear deformation theory. The combined influence of the higher-order shear deformation, plate geometry, lay-up, and ply-angle on the response history of displacements and stresses of bimodulus angle-ply composite laminates is examined.
Numerical Filling Simulation of Injection Molding Based on 3D Finite Element Model
Authors: Zhou Huamin , Geng Tie , Li Dequn
Published: May 2005

The traditional numerical simulation of injection molding is the 2.5D technique based on the Hele-Shaw approximation, which cannot predict the filling of thick or nonuniform-thickness parts and some flow behaviors such as the fountain flow. A three-dimensional (3D) finite element model is presented to perform more accurate simulations of a fully 3D flow. The model employs an equal-order velocity-pressure interpolation method. The relation between velocity and pressure is obtained from the discretized momentum equations in order to derive the pressure equation. A 3D control volume scheme is introduced to track the flow front. The validity of the model has been tested by case studies and experimental verification.
Mixed Mode Fracture Analysis of the Lap Shear Specimen Test Per ASTM D1002
Authors: Yeh Hsien-Yang , Tandjung Darmo
Published: May 2005

ASTM D1002 is a standard test method used to evaluate the shear strength of adhesives. This method is popular due to the simplicity of the test, ease to replicate, and the consistency of the testing results. However, this test is also the most criticized one, as the results can be too misleading to be used as design criteria.

Due to the material elastic mismatch and the eccentricity of the test setup, a mixed mode loading is introduced to the adhesive joint. This paper presents a detailed study on the behavior of the adhesive joint under the shear loading, tested by the ASTM D1002 method. The conventional fracture mechanics theory is utilized.

A crack embedded in the adhesive joint specimens, including both the single thickness and the double thickness, are used for the analysis. The specimen is loaded on a tensile test machine until failure, and the load and displacement are recorded for each specimen. The result from the experiment is used as the data for the stress and fracture mechanics analysis.

From the experimental results, it is seen that the specimen also experiences out-of-plane tensile stress. There is an indication that the final failure might be due to cleavage loading, for the double thickness. The eccentricity of the loading path cannot be eliminated completely. The results of the experiment and the effect of the mixed mode loading are studied in detail.

This paper provides a better understanding of the behavior of adhesives under a mixed-mode fracture. This knowledge is beneficial to understand and design reliable adhesive bond joints.
A Heat Transfer Analysis of the Fiber Placement Composite Manufacturing Process
Authors: Hassan Noha , Thompson Joseph E. , Batra R. C. , Hulcher A. Bruce , Song Xiaolan , Loos Alfred C.
Published: May 2005

A computer code is developed to accurately simulate the three-dimensional heat transfer during the thermoset fiber placement composite manufacturing process. The code is based on the Lagrangian formulation of the problem. Eight-node brick elements are employed, and the 2 × 2 × 2 integration rule is used to numerically evaluate the integrals over an element. The coupled ordinary differential equations obtained by the semidiscrete formulation of the problem are integrated by the unconditionally stable backward difference method. The code is validated by comparing the computed results for several problems with those available in the literature. Composite rings are manufactured by continuously laying a tape over a cylindrical mandrel and the temperature histories at several points are measured with thermocouples. The computed temperature distribution is found to compare well with the test findings. The code can be used to optimize the processing variables.
Beards, Breasts, and Bodies
Authors: Dozier Raine
Published: May 2005

Gender is commonly thought of as dependent on sex even though there are occasional aberrations. Interviews with female-to-male trans people, however, suggest that sex and sex characteristics can be understood as expressions of gender. The expression of gender relies on both behavior and the appearance of the performer as male or female. When sex characteristics do not align with gender, behavior becomes more important to gender expression and interpretation. When sex characteristics become more congruent with gender, behavior becomes more fluid and less important in asserting gender. Respondents also challenge traditional notions of sexual orientation by focusing less on the sex of the partner and more on the gender organization of the relationship. The relationship’s ability to validate the interviewee’s masculinity or maleness often takes precedence over the sex of the partner, helping to explain changing sexual orientation as female-to-male transsexual and transgendered people transition into men.
Who Manages Feminist-Inspired Reform? An In-Depth Look at Title IX Coordinators in the United States
Authors: Taylor Judith
Published: May 2005

This article presents an analysis of the political consciousness and commitments of six gender equity coordinators who served in the same public agency in the United States during a 20-year period in an effort to contribute knowledge about the people who institute movement-inspired laws and the diverse ways in which they come to understand their mandates and the organizational and political milieus within which they work. The author’s findings corroborate existing research indicating that bureaucrats have considerable autonomy to interpret equity law and vary in their approaches. Most significantly, the author shows the ways in which individuals’ commitment to movement ideals can deepen (rather than abate) in the course of working as equity bureaucrats.
What is Behind the Curtain? A Woman’s Perspective on European Issues
Authors: Kowalska Anna
Published: May 2005

In this paper the author evaluates the situation of women in contemporary Polish society. Using statistical data and information from different disciplines, evidence is given that the situation of women today, in Poland, is worse than before 1989. Although, in general, women are better educated than men, adapt better to modern life, and have access to a growing variety of professional careers, the traditional image of women and of family life persists. Women still endure the double burden of professional work and care for the household. They earn less and are more easily affected by unemployment and weak social assistance. They are also more affected by the dysfunctional aspects and low quality of public medical health care and face more risks due to weak access to medical services and high additional costs. This picture contrasts strongly with the situation of women in Western European countries, enjoying more personal autonomy, democratic freedom, social and economic security, financial independence, and access to the consumer market.
Religion, Ecology, and Gender: A Jewish Perspective
Authors: Tirosh-Samuelson Hava
Published: May 2005

This article examines the reasons for the limited interest in environmentalism in Judaism. The author suggests that the reasons are both historical and theological, Jews have been an urban people since the tenth century and they are also people of the book—that is a culture that sees any distraction from scholarly contemplation as less than worthy. However, over the past three decades there has been an interest and this is in response to the claim that the Judeo-Christian tradition is to blame for the environmental crisis. The author challenges the notion that nature can be seen as the base of a core ethic of care pointing out that it is violent and does not care for the weak. The article challenges earth-based spirituality as it has appropriated the kabbalah, particularly the Skehinah and suggests that a misreading underpins this approach.
The Flow Behaviors of MR Fluids Flowing Through an Orifice for Damper Designing
Authors: Wang Yibing , Xu Minglong , Qiu Yang
Published: May 2005

The flow behavior of magnetorheologic fluids (MRFs) flowing through variable orifices were experimented and the properties of the magnetic field around the orifice were analyzed by the finite element method in this article. The results show that the magnetic effects of MRF differ according to: the material, the position, and the thickness of the rectangular orifice. In this article, the relationship between orifice shapes and flow behavior of MRF is described. The results are valuable for MRF device design.
The Use of Magnetorheological Fluid Dampers to Reduce Servo Drive Velocity Jumps due to Load Changes
Authors: Milecki Andrzej , Sedziak Dariusz
Published: May 2005

A problem of velocity control of servo drives in the presence of high load changes is described and studied in this article. The rapid fall of load causes an unexpected jump of the movable elements of the machine. The increase of velocity is harmful and may be reduced by usage of electrically controllable dampers. Such dampers employ a magnetorheological fluid that changes its properties in the presence of a magnetic field. This results in a damper whose characteristics may by adapted in real time to the user’s requirements. In this article the construction of such a damper is described and a machine tool servo drive with an MRF damper is presented. Its simulation model is proposed and some simulation and control analyses are made. Finally experimental results of servo drive velocity control in the presence of load changes are presented. The article is focused on velocity jump reduction which is caused by load decrease.
Exact Solutions of Functionally Gradient Piezothermoelastic Cantilevers and Parameter Identification
Authors: Ying Chen , Zhifei Shi
Published: May 2005

Based on the theory of elasticity, some exact solutions of functionally gradient piezothermoelastic cantilevers under different coupled loadings are obtained. As an application, these solutions have been successfully used to identify the gradient piezoelectric parameter and the thermal material coefficients. Besides, some numerical results have been carried out for the cantilever under two different kinds of loadings. It is found that the tip deflection of the cantilever agrees very well with the experimental and theoretical findings provided by other investigations. The present study also shows that the linear change of thermal material parameters does not influence the distribution of the stress and induction of the cantilever. But it influences the components of strain and electric field strength as well as the displacement and electric potential of the cantilever.
Penalization and retreat
Authors: Pakes Francis
Published: May 2005

This article examines criminal justice policy in the Netherlands from 1994 until 2002. These so-called purple years, in reference to the labour-liberal coalition government in office were characterized by falling crime rates and a hugely expanding criminal justice state at the expense of traditional Dutch reductionist penal policy. The emergence of a Dutch-style crime complex requires scrutiny in light of Downes’s emphasis on Dutch post-war tolerance towards lawbreakers. I conclude that tolerance no longer is a driving force in penal matters but it continues to inform the governance of areas of ambiguous morality such as euthanasia and prostitution. The beneficiaries of the new tolerance are no longer offenders but rather those making certain life choices or preferring certain lifestyles. This article looks at causes and effects of these changes in the nature of criminal justice governance in the Netherlands.