bluuebunny/crossref_metadata_2025 huggingface dataset:
Pitch plane analysis of a twin-gas-chamber strut suspension
Authors: Cao D , Rakheja S , Su C-Y
Published: September 2008

A twin-gas-chamber hydropneumatic suspension strut concept is proposed to achieve enhanced bounce and pitch ride, and pitch attitude control. The response characteristics of the twin-gas-chamber strut suspension are compared with those of a single-gas-chamber strut suspension to demonstrate not only superior performance potentials but also the added design flexibility offered by the twin-gas-chamber struts. The relative responses of both strut suspensions are evaluated through analysis of a pitch plane vehicle model, subject to straight-line braking inputs and excitations arising from randomly distributed road elevations. A generalized formulation for the strut forces is presented to derive the bounce and pitch rates of the proposed strut suspensions. The results reveal that the twin-gas-chamber strut suspension exhibits a slightly lower pitch stiffness in the vicinity of design ride height, but progressively hardening effects with increasing pitch deflections. Moreover, the twin-gas-chamber strut suspension exhibits considerably fewer hardening—softening effects in suspension rate compared with the suspension involving the single-gas-chamber struts. The results attained from the parametric studies are also discussed to demonstrate superior design flexibility of the twin-gas-chamber struts for tuning of the suspension bounce and pitch stiffness properties. The dynamic responses of the vehicle model with different suspensions are assessed subject to random road roughness excitations as well as braking torque inputs. The results demonstrate that the twin-gas-chamber strut suspension offers considerable potential for enhancing bounce and pitch ride, pitch attitude control, and suspension travel responses under braking, while the influence on the ride and road-holding responses under random road inputs is insignificant. The results also suggest that a relatively soft front suspension design could provide further enhancement of pitch ride and pitch deflection responses under random road roughness excitations.
Contact resistance study of high-copper alloys used in power automotive connectors
Authors: El Abdi R , Beloufa A , Benjemaâ N
Published: September 2008

Contact resistance of the copper alloys used in automotive connectors was studied in the literature, but no study has been undertaken in order to optimize this resistance for the new high-copper alloys intended for power automotive connectors.

This study was carried out in order to determine the changes in resistance for different loadings and contact geometries. A new generation of high-performance copper alloys was analysed. The used samples were U shaped with a segment containing a sphere and were subjected to insertion (sliding contact) and indentation (static contact) tests. A finite element simulation using the ANSYS code gave contact modellings with or without roughness; this roughness was measured with a profilometer. Numerical modelling of the contact surfaces when the roughness of the materials was taken into account led to results close to the experimental results especially in the case of the lower forces during the indentation test. On the other hand, a relation between the contact resistance and the contact force was established.

These results could help in the choice of a material to provide a good compromise concerning both the electrical and the mechanical aspects for a power connector used for automotive industry.
Unified thermodynamic description and optimization for a class of irreversible reciprocating heat engine cycles
Authors: Chen L-G , Ge Y-L , Sun F-R
Published: September 2008

A unified description of a class of generalized irreversible reciprocating heat engine cycles is given in this paper. The model cycle consisting of two heating branches, two cooling branches, and two adiabatic branches with heat transfer, friction, and variable specific heats of working fluid is established. The thermodynamic performance of the universal cycle is analysed and optimized by using finite time thermodynamics. The relations between the power output and the compression ratio, between the thermal efficiency and the compression ratio, as well as the optimal relation between power output and the efficiency of the cycle are derived by detailed numerical examples. Moreover, the effects of variable specific heats of the working fluid and cycle process on cycle performance are analysed and the major differences of cycle performance are compared when the specific heats of the working fluid are constant and variable respectively. The results obtained herein include the performance characteristics of endoreversible and irreversible reciprocating Diesel, Otto, Atkinson, Brayton, Braysson, Carnot, dual, and Miller cycles with constant and variable specific heats of the working fluid. They can provide some new guidelines for the design practice of real internal combustion engines.
An improved model considering elastic—plastic contact and partial hydrodynamic lubrication for chemical mechanical polishing
Authors: Tsai H-J , Jeng Y-R , Huang P-Y
Published: September 2008

Chemical mechanical polishing (CMP) has become a primary technique for planarization of semiconductor wafers in sub-micro device fabrication. A physical CMP model combines the effects of grain flow hydrodynamic lubrication, pad roughness, and asperity contact between wafer and pad. In this study, an improved CMP model, considering both the grain flow with roughness effects and the micro-contact mechanism, is proposed. The model applies the average lubrication equation with partial hydrodynamic lubrication theory and considers the elastic—plastic micro-contact theory. The applied load acting on the wafer is balanced by the slurry pressure in the non-contact area, and the surface asperity contact force in the contact area. The effects of the CMP parameters including applied load, rotation speed, particle size, and pad roughness are studied and discussed. The simulation results compare well with experimental data in the literature and contribute to further understanding in wafer—pad contact mechanism.
Lack of Specificity of Commercially Available Antisera: Better Specifications Needed
Authors: Pradidarcheep Wisuit , Labruyère Wil T. , Dabhoiwala Noshir F. , Lamers Wouter H.
Published: September 2008

The ideal antiserum for immunohistochemical (IHC) applications contains mono-specific high-affinity antibodies with little nonspecific adherence to sections. Many commercially available antibodies are “affinity” purified, but it is unknown if they meet “hard” specificity criteria, such as absence of staining in tissues genetically deficient for the antigen or a staining pattern that is identical to that of an antibody raised against a different epitope on the same protein. Reviewers, therefore, often require additional characterization. Although the affinity-purified antibodies used in our study on the distribution of muscarinic receptors produced selective staining patterns on sections, few passed the preabsorption test, and none produced bands of the anticipated size on Western blots. More importantly, none showed a difference in staining pattern on sections or Western blots between wild-type and knockout mice. Because these antibodies were used in most studies published thus far, our findings cast doubts on the validity of the extant body of morphological knowledge of the whole family of muscarinic receptors. We formulate requirements that antibody-specification data sheets should meet and propose that journals for which IHC is a core technique facilitate consumer rating of antibodies. “Certified” antibodies could avoid fruitless and costly validation assays and should become the standard of commercial suppliers.
Strict Glycemic Targets Need Not Be So Strict: A More Permissive Glycemic Range for Critically Ill Children
Authors: Ulate Kalia Patricia , Lima Falcao Germano Correia , Bielefeld Mark Richard , Morales John Mark , Rotta Alexandre Tellechea
Published: September 2008

OBJECTIVE. The goal was to determine whether a more permissive glycemic target would be associated with a decreased incidence of hypoglycemia but not increased mortality rates in critically ill pediatric patients.

METHODS. This retrospective study evaluated clinical and laboratory data for 177 patients who underwent 211 consecutive surgical procedures for repair or palliation of congenital heart defects at Driscoll Children's Hospital. To establish the relationship between postoperative glycemia and subsequent morbidity and mortality rates, patients were stratified into 4 groups according to their median glucose levels, that is, euglycemia (60–125 mg/dL, 3.3–6.9 mmol/L), mild hyperglycemia (126–139 mg/dL, 6.9–7.7 mmol/L), moderate hyperglycemia (140–179 mg/dL, 7.7–9.9 mmol/L), or severe hyperglycemia (≥180 mg/dL, ≥9.9 mmol/L). Postoperative outcomes for those groups also were compared with outcomes for a more permissive glycemic target group (90–140 mg/dL, 5–7.7 mmol/L).

RESULTS. The peak and mean blood glucose measurements and duration of hyperglycemia were not different for survivors and nonsurvivors in the first 24 hours after surgery. Nonsurvivors had higher peak glucose levels (389.3 ± 162 mg/dL vs 274.4 ± 106.3 mg/dL, 21.4 ± 8.9 mmol/L vs 15.1 ± 5.9 mmol/L) and longer duration of hyperglycemia (3.06 ± 1.67 days vs 2.11 ± 0.92 days) during the first 5 postoperative days, compared with survivors. Mortality rates were significantly higher for the moderate (38.8%) and severe (58.3%) hyperglycemia groups, compared with the euglycemia (6.02%) and permissive target (4.69%) groups. The incidence of hypoglycemia was significantly higher in the euglycemia group (31.8%), compared with the permissive target group (17.18%).

CONCLUSIONS. Postoperative hyperglycemia is associated with increased morbidity and mortality rates in children after surgical repair of congenital heart defects. A more permissive glycemic target is associated with a lower incidence of hypoglycemia but not increased mortality rates in these patients.
Textual Encounters of Three Kinds: Engaging in Reading Through Community Astronomy Night
Authors: Johnson Amy Suzanne , Rezak Achariya Tanya , Hodges Georgia , Lawrence Molly , Tippins Deborah , Bongkotphet Thitiya
Published: September 2008

This article describes a community science night as a professional development experience for teachers in a rural school in the southeastern United States. As participants circulated through eight astronomy activities, they engaged in reading images, reading writing, and reading their natural and physical world. Through such diverse textual encounters, participants were given multiple means for accessing science, and teachers were given a model for understanding the relationship between science and literacy.

تصف هذه المقالة ليلة مجتمع علمية كتجربة التنمية المهنية للأساتذة في مدرسة ريفية في جنوب شرق الولايات المتّحدة. حين تجوّل المشتركون في ثماني أنشطة علم الفلك انشغلوا في قراءة الصور وقراءة الكتابة وقراءة عالمهم الطبيعي والمادّي. وقد توفّرت للمشتركين طرق عديدة لتقييم العلم من خلال تجارب ملموسة متنوّعة وتوفّر للأساتذة نموذج لفهم العلاقة بين العلم ومعرفة القراءة والكتابة.

本文描述一间位于美国东南部的农村学校，为教师举办社区科学之夜以作为他们专业培训的经验。当教师巡回参与八项天文学活动时，他们都专注于阅读图像、阅读文字、阅读他们的自然与物理世界。透过这么多样化的篇章接触，参加者认识到多种进入科学知识领域的方法，而教师亦认识到一个用以了解科学与读写能力之间关系的教学模式。

Cet article décrit une séance de nuit d'une communauté scientifique en tant qu'expérience de développement professionnel d'enseignants d'une école rurale du sud‐est des Etats‐Unis. Alors que les participants passaient par huit activités d'astronomie, ils ont été amenés à lire des images, à lire et à écrire, et à lire le monde physique et la nature autour d'eux. Ainsi, au travers de ces diverses rencontres, les participants ont bénéficié d'une multiplicité de moyens d'accès à la science, et les enseignants ont profité d'un modèle permettant de comprendre les relations entre la science et le monde de l'écrit.

В статье описан праздник естественных наук, организованный для местного сообщества в сельской школе на юго‐востоке США, в результате которого учителя этой школы сделали колоссальный шаг вперед в своем профессиональном развитии. Для гостей было подготовлено восемь различных заданий по астрономии: они учились читать изображения, письменный текст, а также явления окружающей природы и мира. Встречи со столь разнообразными видами текста дали гостям множество стимулов и способов заинтересоваться наукой, а учителя познакомились с оптимальной моделью взаимоотношений науки с разными видами грамотности.

Este artículo describe una actividad científica comunitaria que tomó lugar una noche como una experiencia de desarrollo profesional para los maestros de una escuela rural del sureste de los Estados Unidos. A medida que los participantes circulaban por ocho actividades sobre la astronomía, ellos participaron en la lectura de imágenes, la lectura de escritos, y la lectura de su mundo natural y físico. Por medio de tales encuentros con textos diversos, se les dio a los participantes múltiples medios para acceder a las ciencias, y se les dio un modelo para entender la relación entre las ciencias y la capacitación.
Evolving Strategies for the Management of Hand–Foot Skin Reaction Associated with the Multitargeted Kinase Inhibitors Sorafenib and Sunitinib
Authors: Lacouture Mario E. , Wu Shenhong , Robert Caroline , Atkins Michael B. , Kong Heidi H. , Guitart Joan , Garbe Claus , Hauschild Axel , Puzanov Igor , Alexandrescu Doru T. , Anderson Roger T. , Wood Laura , Dutcher Janice P.
Published: September 2008

The multitargeted kinase inhibitors (MKIs) sorafenib and sunitinib have shown benefit in patients with renal cell carcinoma, hepatocellular carcinoma (sorafenib), and gastrointestinal stromal tumor (sunitinib). Their efficacy in other malignancies is currently being investigated because of their broad range of activity. The effectiveness of these drugs is somewhat diminished by the development of a variety of toxicities, most notably hand–foot skin reaction (HFSR). Although HFSR does not appear to directly affect survival, it can impact quality of life and lead to MKI dose modification or interruption, potentially limiting the antitumor effect. Currently, no standard guidelines exist for the prevention and management of MKI-associated HFSR. To address this issue, an international, interdisciplinary panel of experts gathered in January 2008 to discuss and evaluate the best-practice management of these reactions. Based on these proceedings, recommendations for the management of HFSR have been provided to offer patients the best possible quality of life while taking these drugs and to optimize the patient benefit associated with MKI therapy.
Interpretation of sand state from cone penetration resistance
Authors: Ghafghazi M. , Shuttle D.
Published: September 2008

The cone penetration test (CPT) is a widely used test for determining in situ state (or density) of cohesionless soils. The reliability of the estimated in situ state parameter, ψ, is constrained, however, because intrinsic soil properties affect the CPT response (often called a ‘compressibility’ effect). Here, the limiting cavity expansion pressure is used as an analogue for CPT tip resistance, qc, to determine the effect of intrinsic soil properties on the qc versus ψ relation. The limiting cavity pressure is computed by a large strain finite element code using a critical state-based soil model. This cavity expansion idealisation is then scaled to reference calibration chamber data with a universal shape function. The approach leads to a practically simple and theoretically sound method in which results from a few triaxial tests allow calculation of a sand-specific CPT qc–ψ calibration. The method is tested against published reference studies on nine sands and recovers ψ with a precision in void ratio of Δe = ± 0·04 at approximately 80% confidence. This accuracy for soils with elasticity measured by bender elements is considerably greater, Δe = ± 0·04 being obtained at approximately 95% confidence.
FORWARD SELECTION OF EXPLANATORY VARIABLES
Authors: Blanchet F. Guillaume , Legendre Pierre , Borcard Daniel
Published: September 2008

This paper proposes a new way of using forward selection of explanatory variables in regression or canonical redundancy analysis. The classical forward selection method presents two problems: a highly inflated Type I error and an overestimation of the amount of explained variance. Correcting these problems will greatly improve the performance of this very useful method in ecological modeling. To prevent the first problem, we propose a two‐step procedure. First, a global test using all explanatory variables is carried out. If, and only if, the global test is significant, one can proceed with forward selection. To prevent overestimation of the explained variance, the forward selection has to be carried out with two stopping criteria: (1) the usual alpha significance level and (2) the adjusted coefficient of multiple determination () calculated using all explanatory variables. When forward selection identifies a variable that brings one or the other criterion over the fixed threshold, that variable is rejected, and the procedure is stopped. This improved method is validated by simulations involving univariate and multivariate response data. An ecological example is presented using data from the Bryce Canyon National Park, Utah, USA.
Factor Validation of an Instrument Measuring Group Power
Authors: Sieloff Christina Leibold , Dunn Karen
Published: September 2008

Few publications have reported empirical findings regarding the measurement of nursing group power. This article reports the confirmatory factor analyses of the Sieloff-King Assessment of Group Power Within Organizations (SKAGPO) for instrument and middle-range theory development. Secondary analyses were conducted using cross-sectional data collected in 1999. The target population of the initial research was the chief nurse executives (CNEs) of all hospitals within the United States (including Alaska and Hawaii). A sample of 600 hospitals from across the United States was selected through a stratified random sampling process. A total of 350 executives comprised the final sample. Second-order confirmatory 8-factor analysis revealed factor loadings ranging from .43 to .89. The overall fit of the proposed model was: χ2 = 1,360, df = 586, p < .00, GFI = .82, CFI = .86, and RMSEA = .06, indicating an acceptable fit with the data. Statistical support was found for the proposed model with the subsequent development of an alternate model that better fit the data. The study results indicated that the SKAGPO has acceptable psychometric properties.
Measuring Attitudes Toward Participation in Cancer Treatment and Cancer Prevention Trials: The Attitudes Toward Cancer Trials Scales (ACTS)
Authors: Schuber Peggy A.
Published: September 2008

This investigation aimed to develop psychometric instruments that measure attitudes toward participating in cancer treatment trials (CTs) and cancer prevention trials (CPTs), that is, the Attitudes Toward Cancer Trials Scales (ACTS). A conceptualized construct of attitudes toward CTs and CPTs guided the writing of items for psychometric measurement. An expert panel assessment condensed reduced items to 116, and these were formatted into a self-report written survey. Data collection occurred within multiple settings, targeting an ethnically diverse sample (N = 312). Item and principal component analyses empirically supported the Attitudes Toward Cancer Trials Scales (ACTS), a 2-dimensional instrument containing an 18-item CT scale (four components) and a 16-item CPT scale (3 components) with Cronbach’s alpha values of .86 and .89, respectively. Four components comprised the CT scale: personal benefits, personal barriers and safety, personal and social value, and trust in the research process. Three components comprised the CPT scale: personal barriers and safety, altruism, and personal value. Early evidence of the internal consistency reliability and construct validity of the ACTS was provided by the sample.
The Perception of Risk of Heart Disease Scale: Development and Psychometric Analysis
Authors: Ammouri Ali A. , Neuberger Geri
Published: September 2008

Perception of risk of getting heart disease is an important predictor of individuals’ engagement in a healthy lifestyle. This study describes the development and testing of the Perception of Risk of Heart Disease Scale (PRHDS). The 20-item instrument was tested in successive steps with 295 individuals for internal consistency, test–retest reliability, and construct validity. The three subscales of dread risk, risk, and unknown risk had internal consistency values ranging from .68 to .80. The total scale alpha was .80. Evidence of the instrument’s stability over time was supported by subscale test–retest reliabilities ranging from .61 to .76. Construct validity was documented with a positive correlation between PRHDS and the Health Promotion Lifestyle Profile II (r = .20 to .39). Further psychometric testing of the PRHDS in a larger sample with a heterogeneous cultural background is recommended.
Rabies surveillance in the United States during 2007
Authors: Blanton Jesse D. , Palmer Dustyn , Christian Kira A. , Rupprecht Charles E.
Published: September 2008

During 2007, 49 states and Puerto Rico reported 7,258 cases of rabies in animals and 1 case in a human to the CDC, representing a 4.6% increase from the 6,940 cases in animals and 3 cases in humans reported in 2006. Approximately 93% of the cases were in wildlife, and 7% were in domestic animals. Relative contributions by the major animal groups were as follows: 2,659 raccoons (36.6%), 1,973 bats (27.2%), 1,478 skunks (20.4%), 489 foxes (6.7%), 274 cats (3.8%), 93 dogs (1.3%), and 57 cattle (0.8%). Compared with numbers of reported cases in 2006, cases in 2007 increased among dogs, bats, foxes, and skunks while decreases were reported among cattle, cats, and skunks. Increases in numbers of rabid raccoons during 2007 were reported by 11 of the 20 eastern states where raccoon rabies was enzootic, and reported cases increased by 1.7% overall, compared with 2006.

On a national level, the number of rabies cases in skunks during 2007 decreased by 1.1% from the number reported in 2006. Texas reported the greatest number (n = 362) of rabid skunks and the greatest overall state total of animal rabies cases (969). No cases of rabies associated with the dog/coyote rabies virus variant were reported. The United States remains free of dog-to-dog transmission of canine rabies virus variants. The total number of cases of rabies reported nationally in foxes increased 14.5%, compared with 2006. Increases in the number of reported rabid foxes were attributable to greater numbers of foxes reported with the Arctic fox rabies virus variant in Alaska, the Texas gray fox rabies virus variant in Texas, and the raccoon rabies virus variant in Virginia. The 1,973 cases of rabies reported in bats represented a 16.6% increase over numbers reported in 2006. Cases of rabies in dogs and in sheep and goats increased 17.7% and 18.2%, respectively, whereas cases reported in cattle, cats, and horses and mules decreased 30.5%, 13.8%, and 20.8%, respectively. In Puerto Rico, reported cases of rabies in mongooses decreased 51.5%, and rabies in domestic animals, presumably attributable to spillover infection from mongooses, increased 25%.

One human rabies case was reported from Minnesota during 2007. Although typing of the rabies virus variant in this case was not possible, an investigation of this case indicated a bat as the most likely source of exposure.
Breed distribution of the ABCB1-1Δ (multidrug sensitivity) polymorphism among dogs undergoing ABCB1 genotyping
Authors: Mealey Katrina L. , Meurs Kathryn M.
Published: September 2008

Objective—To evaluate the breed distribution of the ABCB1-1Δ polymorphism in a large number of dogs in North America, including dogs of several herding breeds in which this polymorphism has been detected and other breeds in which this polymorphism has not yet been identified.

Design—Cross-sectional study.

Animals—5,368 dogs from which buccal swab samples were collected for purposes of ABCB1 genotyping.

Procedures—From May 1, 2004, to September 30, 2007, DNA specimens derived from buccal swab samples collected from 5,368 dogs underwent ABCB1 genotyping. These data were reviewed, and results for each dog were recorded in a spreadsheet, along with the dog's breed. The genotypes for each breed were tallied by use of a sorting function.

Results—The ABCB1-1Δ allele was identified in 9 breeds of dogs and in many mixed-breed dogs. Breeds that had the ABCB1-1Δ allele included Collie, Longhaired Whippet, Australian Shepherd (standard and miniature), Shetland Sheepdog, Old English Sheepdog, Border Collie, Silken Windhound, and German Shepherd Dog (a breed in which this mutation had not been detected previously).

Conclusions and Clinical Relevance—The ABCB1-1Δ polymorphism is associated with increased susceptibility to many adverse drug reactions and with suppression of the hypothalamic-pituitary-adrenal axis and is present in many herding breeds of dog. Veterinarians should be familiar with the breeds that have the ABCB1-1Δ polymorphism to make appropriate pharmacologic choices for these patients.
Evaluation of a questionnaire for obtaining owner-perceived, weighted quality-of-life assessments for dogs with spinal cord injuries
Authors: Budke Christine M. , Levine Jonathan M. , Kerwin Sharon C. , Levine Gwendolyn J. , Hettlich Bianca F. , Slater Margaret R.
Published: September 2008

Objective—To evaluate a questionnaire for obtaining owner-perceived, weighted quality-oflife assessments for dogs with spinal cord injuries.

Design—Evaluation study.

Animals—100 dogs with spinal cord injuries and 48 healthy control dogs.

Procedures—The questionnaire was adapted from a questionnaire (the schedule for the evaluation of individual quality of life–direct weighting) used for human patients. Specifically, owners were asked to identify 5 areas or activities they believed had the most influence on their dogs' quality of life, assess their dogs' current status in each of those areas, and provide a weighting for the importance of each area. Results were used to construct a weighted quality-of-life score ranging from 0 to 100 for each dog. Owners were also asked to provide a quality-of-life score with a visual analog scale (VAS).

Results—A good correlation was found between weighted and VAS quality-of-life scores. Dogs with spinal cord injuries had weighted quality-of-life scores that were significantly lower than scores for control dogs. Quality-of-life areas and activities provided by owners of dogs with spinal cord injuries were similar to areas and activities provided by owners of healthy control dogs and could mostly be encompassed by 5 broader domains: mobility, play or mental stimulation, health, companionship, and other.

Conclusions and Clinical Relevance—Results suggested that the questionnaire could be used to obtain owner-perceived, weighted quality-of-life assessments for dogs with spinal cord injuries. Obtaining owner-perceived quality-of-life assessments for individual dogs should allow veterinarians to better address quality-of-life concerns and expectations of owners.
Some results on multi-valued weakly jungck mappings in b-metric space
Authors: Olatinwo Memudu
Published: September 2008

In this paper, the concept of multi-valued weak contraction of Berinde and Berinde [8] for the Picard iteration in a complete metric space is extended to the case of multi-valued weak contraction for the Jungck iteration in a complete b-metric space. While our main results generalize the recent results of Berinde and Berinde [8], they also extend, improve and unify several classical results pertainning to single and multi-valued contractive mappings in the fixed point theory. Our results also improve the recent results of Daffer and Kaneko [16].
Pleistocene Stratigraphy of Poland and Its Correlation with Stratotype Sections in the Volhynian Upland (Ukraine)
Authors: Lindner Leszek , Marks Leszek
Published: September 2008

Recent stratigraphic subdivision of the Pleistocene of Poland presents 4 complexes: Preglacial, South-Polish, Middle-Polish and North-Polish ones. Each complex comprises a set of stratigraphic units, corresponding to the previously distinguished 8 glaciations/coolings and 7 interglacials/warmings. Three younger complexes and corresponding extents of Scandinavian ice sheets in Poland are described in more detail. Three older interglacials in Poland (Augustovian, Kozi Grzbiet and Ferdynandovian) are characteristic for their bi-optimal climatic sequences but so far, they have no equivalents in loess sections of the Volhynian Upland in the Ukraine. Coolings between the optima of these interglacials are occasionally considered as small glaciations, during which the ice sheet could occupy only a northern part of Poland. All younger interglacials are mono-optimal in Poland and as such, they are also reflected by single palaeosols in loess sections of both countries. Till occurrences in key loess sections of Poland and Ukraine enabled precise delimitation of ice sheet extents, especially within the Middle-Polish Complex with the glaciations Liwiecian, Krznanian and Odranian ascribed to OIS 10, 8 and 6, respectively. During the youngest (Vistulian, Valdai) Glaciation, 3-4 loess deposits were formed in the Lublin and Volhynian Uplands; they are separated by palaeosols that developed during interstadial-rank warmings.
Variability of fluvial transport of the upper Wieprz river
Authors: Stępniewska Sylwia , Stępniewski Krzysztof
Published: September 2008

Variability of fluvial transport of the upper Wieprz river

This paper shows variability of fluvial transport of the Wieprz river. The catchment of the upper Wieprz river to profile at Guciów located in Central Roztocze Region. In Wieprz during the hydrological years 1996-2006 average annual flow is 1.32 m3·s-1, which correspond to the outflow - 41.5 Mm3·a-1. Extreme values of the flows varied from 0.5 m3·s-1 to 13,1 m3·s-1. Outflow the Wieprz river has feature for the snow-rainy hydrological regime. During the study the annual average suspended load amounted 737 Mg. The annual average dissolved load amounted 10 343 Mg. The bed load estimated for less than 10% of the dissolved load and 1% of the suspended load. The monthly average suspended load and dissolved load were least in the November and were highest in the April. During the period of researches, the average mechanical denudation rates 2.4 Mg·km-2·a-1. Chemical denudation rates were much higher - 36.1 Mg·km-2·a-1. Their differentiation are similar in other regions of Poland.
Simplified technique for the determination of soil aggregation in assessing the resistance of soils to erosion and deflation
Authors: Grigoriev Viktor , Piechnik Leszek , Podsiadłowski Stanisław
Published: September 2008

Simplified technique for the determination of soil aggregation in assessing the resistance of soils to erosion and deflation

The technique provides for the determination of the size and percentage of aggregates of the coarse fraction on the surface of a friable soil followed by the determination of the aggregation index to be used in assessing spatial and temporal resistance of soil to erosion and deflation. The uses of this technique make routine sampling and aggregate analysis after Savvinov unnecessary. Its some outcomes for soils of Poland are given.
Credits, Time, and Attainment: Articulation Policies and Success After Transfer
Authors: Roksa Josipa , Keith Bruce
Published: September 2008

While state legislatures are increasingly enacting articulation policies, research to date provides little evidence that these policies enhance students’ likelihood of transfer. Based on a careful historical review of state statutes, the authors propose that articulation policies do not improve transfer rates because that is not their intended purpose; the main goal of articulation policies is to prevent the loss of credits when students transfer within state higher education systems. Subsequently, the authors use the National Education Longitudinal Study to evaluate articulation policies based on an alternative set of outcomes: attainment of a bachelor’s degree, time to degree, and credits required to complete a bachelor’s degree. They discuss the limitations of existing data and propose that future studies be designed to specifically evaluate the transfer or loss of credits applicable toward general education requirements.
District Policy and Teachers’ Social Networks
Authors: Coburn Cynthia E. , Russell Jennifer Lin
Published: September 2008

Policy makers increasingly include provisions aimed at fostering professional community as part of reform initiatives. Yet little is known about the impact of policy on teachers’ professional relations in schools. Drawing theoretically from social capital theory and methodologically from qualitative social network analysis, this article explores how district policies influence teachers’ social networks in eight elementary schools in two districts involved in the scale-up of mathematics curriculum. It is argued that policy affects whom teachers seek out for discussion of mathematics instruction but that differences in policy provisions lead to variations in the nature and quality of interactions. Furthermore, school leaders mediate district policy, thereby influencing these patterns of interaction. By uncovering the dynamics by which policy influences teachers’ social networks, this article contributes to understandings of the factors that foster the development of social capital. It also uncovers opportunities for intervention for those designing policy initiatives to support implementation of instructional innovations.
Ultrasonographic Examination of the Deltoid Ligament in Bimalleolar Equivalent Fractures
Authors: Chen Pei-Yu , Wang Tyng-Guey , Wang Chung-Li
Published: September 2008

Background: Lauge-Hansen supination-external rotation Stage IV ankle injuries may simulate a Stage II or Stage III injury radiographically if the medial disruption occurred through the deltoid ligament instead of the medial malleolus, making it difficult to determine whether an operation is indicated. Materials and Methods: Seventeen patients presented with radiographically isolated lateral malleolar fractures at the syndesmotic level. They were examined with ultrasonography for evaluation of the integrity of the deltoid ligament. Patients in whom ultrasonography showed complete rupture of the deltoid ligament received operative fixation of the ankle fracture, with exploration and repair of the deltoid ligament at the same time. Patients without complete rupture of the deltoid ligament were treated conservatively with a short leg cast for 6 weeks followed by an ankle brace for another 6 weeks. Nine male and six female patients completed the final clinical and radiographic evaluations. Results: Ultrasonography showed complete rupture of the deltoid ligament in six patients. Exploration of the deltoid ligaments confirmed the sonographic findings in all these patients. In the remaining nine patients, the deltoid ligaments were not completely ruptured on ultrasound. These fractures were treated conservatively, and all healed uneventfully. All the 15 patients had good or fair results on the final evaluation. Conclusion: Ultrasonography is a convenient and accurate diagnostic tool to differentiate unstable bimalleolar-equivalent ankle fractures from an isolated lateral malleolar fracture. Thus, it can be helpful in the decision process for the treatment of choice for different fracture patterns.
The Effect of Stage II Posterior Tibial Tendon Dysfunction on Deep Compartment Muscle Strength: A New Strength Test
Authors: Houck Jeff R. , Nomides Candace , Neville Christopher Glenn , Flemister Adolph Samuel
Published: September 2008

Background: The purpose of this study was to compare isometric subtalar inversion and forefoot adduction strength in subjects with Stage II posterior tibial tendon dysfunction (PTTD) to controls. Materials and Methods: Twenty four subjects with Stage II PTTD and fifteen matched controls volunteered for this study. A force transducer (Model SML-200, Interface, Scottsdale, AZ) was connected with a resistance plate and oscilloscope (TDS 410A, Tektronix, Beaverton, OR) to the foot. Via the oscilloscope, subjects were given feedback on the amount of force produced and muscle activation of the anterior tibialis (AT) muscle. Subjects were instructed to maintain a plantar flexion force while performing a maximal voluntary subtalar inversion and forefoot adduction effort. A two-way ANOVA model with the factors including, side (involved/uninvolved) and group (control/PTTD) was used. Results: The PTTD group on the involved side showed significantly decreased subtalar inversion and foot adduction strength (0.70 ± 0.24 N/Kg) compared to the uninvolved side (0.94 ± 0.24 N/Kg) and controls (involved side = 0.99 ± 0.24 N/Kg, uninvolved side = 0.97 ± 0.21 N/Kg). The average AT activation was between 11% to 17% for both groups, however, considerable variability in subjects with PTTD. Conclusion: These data confirm a subtalar inversion and forefoot adduction strength deficit by 20% to 30% in subjects with Stage II PTTD. Although isolating the PT muscle is difficult, a test specific to subtalar inversion and forefoot adduction demonstrated the weakness in this population.
Radiographic and Pedobarographic Comparison of Femoral Head Allograft versus Block Plate with Dorsal Opening Wedge Medial Cuneiform Osteotomy: A Biomechanical Study
Authors: League Alan C. , Parks Brent G. , Schon Lew C.
Published: September 2008

Background: The effect of the Cotton osteotomy has not been studied in isolation, and no alternative to bone graft has been investigated for this osteotomy. We hypothesized that there would be no difference in radiographic and pressure findings using the Cotton osteotomy with bone graft or an opening wedge block plate. Materials and Methods: Each specimen of eight matched pairs of lower extremities was loaded in simulated double-leg stance via pneumatic cylinders as described previously. Weightbearing lateral and anteroposterior radiographs and medial and lateral pressure measurements were obtained for all intact specimens. Specimens were randomly assigned to receive a Cotton osteotomy with a dorsal opening wedge allograft or an opening wedge plate. Each specimen was cycled at 3 Hz to 720 N for 5000 cycles and measurements were repeated. Results: Calcaneal pitch was lower after the block plate procedure (mean ± standard error of the mean) (intact, 23.4 ± 1.2 degrees versus post-procedure, 21.8 ± 1.1 degrees; p = 0.05). There was a significant difference ( p < 0.05) in percentage of total plantar pressure medially and laterally between the intact specimen and the specimen after osteotomy with both methods. Pressure increased medially and decreased laterally. Conclusion: With the numbers available, these methods for performing a Cotton osteotomy did not differ in addressing lateral column overload. Clinical Relevance: Dorsal opening wedge medial cuneiform osteotomy performed with femoral head allograft or a block plate may be effective both in reducing lateral column pressures and increasing medial column pressures when they are deficient preoperatively.
Crossed Screws versus Dorsomedial Locking Plate with Compression Screw for First Metatarsocuneiform Arthrodesis: A Cadaver Study
Authors: Gruber Florian , Sinkov Vladimir S. , Bae Su-Young , Parks Brent G. , Schon Lew C.
Published: September 2008

Background: We hypothesized that a dorsomedial locking plate with adjunct screw compression would provide superior rigidity compared to crossed screws for first metatarsocuneiform (MTC) arthrodesis. Materials and Methods: In ten matched lower extremity pairs, specimens in each pair were randomly assigned to receive screw fixation or plate with screw fixation. Bone mineral density (BMD) was measured. For the crossed-screw construct, two 4.0-mm cannulated screws were used. One screw was inserted dorsal to plantar beginning from the first metatarsal 10 to 15 mm distal to the joint, and the second was inserted from the cuneiform 8 to 10 mm proximal to the joint, medial to the first screw, into the first metatarsal. For the plate construct, a 4.0-mm cannulated compression screw was inserted from the dorsal cortex of the first metatarsal to the plantar aspect of the medial cuneiform. A locking plate was inserted dorsomedially across the MTC joint. Specimens were loaded in four-point bend configuration (displacement rate, 5 mm/min) until failure of the fixation or 3-mm deformation. An extensometer was used to measure deformation. Results: There was no difference in load to failure or stiffness between the two groups. BMD was positively correlated with load to failure in the screw ( r = 0.893, p = 0.001) and the plate ( r = 0.858, p = 0.001) construct. Conclusion: The plate construct with compression screw did not show different rigidity as compared with the screw construct with the numbers available. Clinical Relevance: Further investigation of a dorsomedial plate with adjunct screw compression may be warranted for first MTC arthrodesis.
Implementing Intelligent Compaction Specification on Minnesota TH-64
Authors: White David J. , Thompson Mark J. , Vennapusa Pavana , Siekmeier John
Published: September 2008

An intelligent compaction (IC) specification that required variable feedback amplitude control was recently implemented on the TH-64 reconstruction project in Minnesota. At this site, IC and in situ measurement values were collected to characterize the empirical relationships and variation associated with each measurement value, ultimately to develop a process that better describes the geospatial nature of the data. A geographic information system database was created with IC measurement values and parallel quality assurance data to demonstrate one method for managing large quantities of data. Spatial geostatistics were also examined by using variogram modeling for characterizing uniformity. The findings from this study provide guidance on implementing IC specifications regarding effective use of the technology and some of the challenges that still remain.
Parameter Estimation for Evaluation of in Situ Density and Moisture Content by using Elastic and Electromagnetic Wave Propagation
Authors: Alramahi Bashar , Fratta Dante , Alshibli Khalid A.
Published: September 2008

Soil density and moisture content are two essential properties in the quality control and quality assurance of projects that involve soil compaction. However, current field practices either are destructive and time-consuming (i.e., sand cone or water balloon for soil density and oven drying for moisture content) or include hazardous substances that require special handling and operating procedures (i.e., nuclear density gauge). Therefore, new robust, reliable, and nonnuclear techniques for the determination of in situ density and moisture content would assist in quality control and quality assurance processes and would allow more measurements to be performed in a shorter time. A methodology for the in situ determination of density and moisture content by using the propagation of elastic and electromagnetic waves through soils was evaluated. It is based on a semiempirical model that relates elastic wave velocity through soils to the water content, porosity, and degree of saturation. An experimental program was used to verify the model and examine its range of applicability. It was also used to examine the accuracy and limitations of the suggested methodology. An analysis was made of the experimental assessment, along with a detailed numerical study of the inversion procedure used to calculate the density and moisture content. Although the parametric and experimental study shows that the methodology can provide an estimate of density and water content rapidly and non-destructively, there are inherent accuracy and precision limitations that need to be solved. These results also show that combined elastic and electromagnetic wave propagation measurements can help in the development of a methodology that may assist in solving inconsistencies in stiffness measurements.
Compaction-Induced Earth Pressures against a Sheet Pile Wall in Peat
Authors: Tan Yong , Lu Ye
Published: September 2008

With vibrating-wire total pressure cells instrumented on sheet pile walls in peat bogs, lateral earth pressures developing in peat against the supporting faces of sheet pile walls were measured during deep dynamic compaction (DDC). The measured total lateral earth pressures induced by impaction at different tamping points were examined. Analyses of field data indicated that during DDC, pressure increments increased linearly with blow counts. Under the same compaction energy, pressure increments were determined by both the horizontal tamping distance, X (distance from a tamping point to sheet pile walls), and the vertical depth, Y (distance to ground surface). Compaction-induced earth pressure increments could be modeled by an exponential relationship with both X and Y. Finite element method simulation showed a similar tendency as field measurements, verifying that the developed exponential relationships reasonably interpret the mechanism of soil–structure interaction under dynamic compaction conditions.
Evaluation and Recommendations for Flowfill and Mechanically Stabilized Earth Bridge Approaches
Authors: Abu-Hejleh Naser M. , Hanneman Dennis , Wang Trever , Ksouri Ilyess
Published: September 2008

To alleviate the common bridge bump problem, the Colorado Department of Transportation (CDOT) has employed three new alternatives for bridge abutment backfill since 1992: flowfill, mechanically stabilized earth (MSE) using well-graded granular Class 1 backfill (reinforced soil mass as in MSE walls), and MSE using free-draining Class B filter material. However, the occurrence of bridge bump problems is still reported. A study evaluated CDOT current practice for design and construction of bridge approaches and then developed recommendations to improve this practice (improve performance and reduce costs) on the basis of the results of the following: (a) best practices for bridge approaches collected from CDOT staff and reported in the literature, (b) evaluation of the performance and cost-effectiveness of Colorado's MSE and flowfill bridge approaches, and (c) identification of the causes of significant bridge approach settlement problems observed in some of Colorado's MSE and flowfill bridge approaches. Evaluation procedures and forensic investigations were developed and applied to obtain the information needed for the first two items. Flowfill should remain a viable alternative for certain field and construction scenarios that justify its higher costs. MSE approaches with both Class B and Class 1 backfill materials should be routinely used in future CDOT projects with documentation of their performance and cost (construction and repair costs) for a future evaluation. Comprehensive recommendations are presented to mitigate the observed bridge approach settlement problem; the most important recommendations are for improved support and drainage systems for the sleeper slab where the settlement problem occurs.