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Large bolts are used in applications which are subjected to fatigue loads, such as the M72 bolts used in ring flanges of wind turbine towers. Pretension is used as a means of protecting bolts against fatigue loading. Design standards require particular levels of pretension to be applied. For example, 70% of the bolt’s proof strength is often specified. However, in practice, bolts may not be experiencing the required level of pretension. Pretensioning procedure, joint face distortion and in-service relaxation can all influence resulting bolt pretension. However, no guidance is available on the fatigue performance of pretensioned bolts when the pretension is less than the specified value. In this work, a series of tests was carried out using a specially designed test jig, which allowed bolts to be pretensioned and then a fatigue load to be applied to the joint faces. Pretension was applied to the bolts using a hydraulic tensioning tool, and the resulting bolt tension was measured using strain gauges. The pretensions used were intentionally less than the recommended level. The fatigue test results showed that it was necessary to apply a significantly higher level of tension (an overtension) with the hydraulic tool prior to tightening the nut in order to achieve a particular target level of pretension. This overtension was more than two times the target tension. In terms of bolt fatigue performance, as expected, increasing the pretension reduced the load range experienced by the bolts and so increased fatigue life. The mean S-N curve for the pretensioned bolts was similar to and slightly higher than the mean S-N curve obtained from bolts tested without pretension. A relationship was derived, which allows bolt load range to be calculated for a given bolt pretension and applied load range.

Mechanically lined pipe (MLP) is a lower cost alternative to clad pipe, and is used to carry corrosive fluids in oil and gas applications. The pipe includes a liner which is made from corrosion resistant alloy (CRA). The liner is fixed at both ends using seal welds and a length of weld overlay. This results in a junction between the backing steel, weld overlay and liner, which is called the transition point or the triple point. When lined pipe is subjected to fatigue loading, the triple point has been shown to be location where fatigue cracks initiate. Flaws present at the triple point will grow in service. When a flaw breaches the liner, the backing steel will be exposed to the corrosive fluid, limiting the remaining life of the pipeline. It is therefore of interest to perform fracture mechanics calculations to understand fatigue crack growth from the triple point, so that the operational service life of MLP can be calculated if a flaw is present at the triple point. In order to do this, a stress intensity factor, K, is needed which describes the stress intensity at a crack tip at the triple point. However, owing to the unique geometry of this location, no stress intensity factor solution currently exists for the triple point location. To overcome this challenge, parametric finite element models were developed to calculate stress intensity factors for triple point crack-like flaws. This paper presents results from a work package from a joint industry project whose aim was to understand the fatigue performance of mechanically lined pipe. Finite element analysis was used to develop K solutions for the triple point in mechanically lined pipe by developing geometry-specific Y-factors for the MLP triple point geometry. An engineering critical assessment was then performed. The calculated fatigue life agreed well with results from full scale resonance fatigue tests and demonstrates the value of using FEA to derive geometry-specific K solutions for this geometry.

The distribution of many fishes that occupy large rivers is poorly known, in part due to the difficulties of sampling for them. This is especially true for small-bodied or rare species, such as the snail darter Percina tanasi, 44, 469-488; 1976). This federally listed (threatened) species has a limited distribution in the Tennessee River system in Alabama and Tennessee, where it is known from a few large tributaries or small rivers. In Alabama, P. tanasi was previously known from only one locality, but has recently been found in two additional, widely separated systems. These new records raise questions regarding the accuracy of our current understanding of the range for this species. Particularly, is P. tanasi present throughout the main stem Tennessee River, and is this species dispersing into new areas from source populations in the river? To clarify the distribution of P. tanasi in Alabama, 83 unique sites were surveyed using environmental DNA analysis. This cost-effective detection tool reduces the difficulty associated with empirically sampling large rivers for small fishes. Approximately 42% of sites sampled were positive for P. tanasi DNA. This study confirmed the known localities of P. tanasi in the Bear Creek, Elk River and Paint Rock River. Several new localities were also discovered throughout the main stem Tennessee River and in Shoal Creek, near Florence, Alabama. These findings can inform biologists about where to prioritize conservation efforts and further could lead to studies assessing movement and relatedness between populations in this system.

Sport participation can play a key role in older adults’ successful aging as it provides an enjoyable opportunity for leisure-time physical activity. Research focusing on the benefits of sport participation in later life and facilitators for involvement has been increasing in the past several years. Drawing on the socioecological model, this study investigated select socioecological factors that predict older adults’ sport participation from a holistic perspective. An online survey provided quantitative data from 1203 adults aged 50 and older across the United States. Results from logistic regression analyses showed that personal characteristics, individual behavior, environment/policy, and life course effects were significant predictors of sport participation in later life. The findings in this study enhance our understanding of factors related to older adults’ sport participation and are also of value to practitioners seeking to promote sport participation among older adults.

Background: Females are prone to urinary tract infections (UTIs) due to estrogen fluctuations affecting vaginal flora. While menstruating, increased fluid consumption to support urination frequency and void volume may be important, as the urethra and urinary tract are more predisposed to bacteria, particularly UTI pathogens. Aim: This study aimed to investigate the impact of hydration on urinary tract health during menstruation among underhydrated premenopausal women. Methods: Thirteen females participated in a 60-day 2 × 2 randomized crossover trial to evaluate the effectiveness of consuming ≥2.2 L of total beverage fluid intake, with 1.9 L being water, (intervention, INT) and maintaining habitual fluid intake (control, CON) on two subsequent menses. Participants completed fluid and urination diaries at days 2 and 5 after the onset of bleeding (day 1) to determine the fluid amount consumed and urination frequency. Urine concentration was assessed in afternoon (days 2 and 5) and uropathogenic bacterial activity in first-morning (days 3 and 6) urinations. General linear models assessed differences in bacterial and hydration outcomes. Results: The intervention led to a 62% mean total fluid increase, INT 3.0 ± 1.1 L and CON 1.9 ± 0.9 L, p s

Now that bolted flanges rather than grouted connections are used to join the transition piece to the monopile in offshore wind turbine towers, many large bolts are being used in applications which subject them to fatigue loads. The bolts in these ring flanges are typically M64 or M72 in size (ie 64mm of 72mm nominal diameter). The fatigue design codes, BS 7608, DNVGL-RP-C203 and Eurocode 3 do provide S-N curves for threaded fasteners, but the reference diameter in those documents is 25mm or 30mm. A thickness correction is provided, to account for larger diameter bolts, but this was originally derived by analysis of the performance of welded joints. It is unclear whether the S-N curves and the recommended thickness correction are appropriate for larger diameter threaded fasteners. The offshore wind industry usually specifies hot dip galvanised bolts, to provide some corrosion protection in the offshore environment. Again, there is uncertainty over whether the S-N curves in fatigue design standards apply to bolts with a galvanised coating. Since the fatigue design codes provide S-N curves for air, free corrosion or seawater with cathodic protection, it is also unclear which of these should be used to predict the fatigue performance of bolts with a galvanised coating. In order to provide data to address these uncertainties, hot-dip galvanised, grade 10.9, M72 bolts from two manufacturers were tested in both air and a seawater environment. In order to represent the conditions experienced by bolts in internal ring flanges, the artificial seawater was sprayed onto the bolts during testing. Tests were conducted with a mean stress corresponding to 70% of the specified minimum 0.2% proof strength of the bolts. Tests were also performed in air, on uncoated M72 bolts, and uncoated M64 bolts for comparison. The results suggest that the current thickness correction in DNVGL RP C203 and BS 7608 is appropriate for M72 bolts. The results in air from the galvanised bolts were below those from uncoated bolts. Although the galvanised results were above the thickness corrected in-air standard design curves (BS7608 Class X -20%, DNVGL Class G and DNVGL ST 0126 FAT 50), they were below the mean curves, suggesting that the performance of galvanised bolts is slightly lower than the existing recommendations.

Vibration induced fatigue is a well-known problem in oil and gas piping systems. However the use of vibration data to detect damage is not an easy task without a priori knowledge of the undamaged condition. In this paper, level 1: Detection and level 2: Localization of damage from structural health monitoring strategies is adapted for damage identification. An experimental trial of acoustic emission monitoring was run to monitor fatigue damage during a full-scale resonance fatigue test of a girth-welded steel pipe from healthy condition until failure. The pipe was excited into the first mode of vibration using a resonance fatigue testing machine in order to determine the high-cycle fatigue strength of the weld. The information provided by acoustic emission monitoring is useful in evaluating the condition of the pipe during the test and the occurrence of cracking before failure. However, the acoustic emission signals are embedded in noise. To overcome this problem, the signals from different combinations of sensors were recursively cross-correlated, which provides for the derivation of a new effective coefficient (EC) parameter for Bayesian estimation. This parameter is useful for evaluating uncertainty arising from the signals that contribute to source localization errors. The estimation finds the most probable parameters corresponding to cracks using prior knowledge derived from standard pencil lead break tests. The proposed method demonstrates a strong relationship between the acoustic emission energy and the estimated coefficients. A high correlation between signals was found to be associated with cracking, and a low correlation between signals was found to be associated with random signals or noise. The method will be useful for monitoring the condition of piping to manage the risk of vibration induced fatigue failure.

Design of Steel Catenary Risers (SCRs) requires the use of specialized connection hardware to mitigate the high dynamic bending moments at the hang-off location induced by host floater motion. Reliability of this connection hardware is imperative, especially in those applications involving high tension loads, high pressure and elevated fluid temperature. One option for connection hardware is a monolithic, metallic tapered stress joint. Because of its inherent density, strength, and stiffness properties, steel is not well suited for these applications due to excessive stress joint length and weight requirements. Titanium Grade 29 has been identified as an attractive material candidate for demanding service applications due to its unique mechanical properties including increased flexibility, excellent fatigue performance and corrosion resistance to sour fluids. This technology is well established in the offshore industry and utilized in over 60 SCR installations with operating lives exceeding 20 years of continuous subsea operation. Large titanium stress joints (TSJs) for deep-water applications are typically not fabricated as a single piece due to titanium ingot volume limitations thus making one or more intermediate girth weld(s) necessary to satisfy the overall length requirements. Fatigue testing of 38 mm (1.5-in) wall thickness girth welds, utilizing an optimized GTAW welding procedure to limit defect sizes to sub-millimeter, has previously been performed in seawater (OD exposure) under cathodic protection potentials and sour service (ID exposure) under galvanic potentials. Fatigue testing results fully verified the vendor S-N fatigue design curve, in addition, no appreciable differences in fatigue performance in environments were observed allowing project-specific testing to be limited to in-air testing. This paper presents in-air fatigue testing results of 51 mm (2.0-in) wall thickness Grade 29 girth welds, using the same optimized welding procedure, to assess thickness size effect on the vendor S-N fatigue design curve. Verification of the vendor fatigue design curve was demonstrated by testing curved dog-bone specimens, extracted longitudinally across the girth weld, with production level surface finishes on inner and outer surfaces in-air up to a predefined S-N fatigue target curve with 95% confidence level.

High cost of metal powders has increased the demand for recycling of unmelted powder in electron beam powder bed fusion additive manufacturing process. However, powder characteristics are likely to change during manufacturing, recovery and reuse. It is important to track the evolution of powder characteristics at different stages of recycling to produce components with consistent properties. The present work evaluates the changes in Ti6Al4V powder properties during manufacturing by characterising powder particles at different locations in the powder bed; recovery and reuse, through evaluating the effects of the powder recovery system and sieving for 10 build cycles. Heterogeneous powder degradation occurred during manufacturing with the particles closer to the melt zone showing higher oxygen content and thicker α laths with β phase boundaries. Most of them had a hard-sintered and agglomerated powder morphology in contrast to particles at the edges of the powder bed. Recovery and reuse resulted in a refined particle size distribution, but only marginal change in powder morphology. The increased oxygen caused a slight increase in the yield and tensile strengths of the build. The effect of powder reuse on material elongation, hardness and Charpy impact energy was negligible. The high cycle fatigue performance deteriorated with reuse due to the increased lack-of-fusion defects. This might be attributed to the voids formed in the powder bed due to decrease in the number of fine particles coupled with an increase in the number of high-aspect ratio particles.

Background Over 16 million U.S. adults report a major depressive episode each year. Hispanic females comprise the highest number of U.S. births compared to other race/ethnicities and are expected to remain as the Hispanic population grows. Research postulates that depression often co-occurs within families and is passed down to future generations but has yet to determine racial/ethnic disparities for depression and more acute forms including ideation. Methods Using data from the Fragile Families and Child Wellbeing Study, latent class analyses examined the association of primary caregiver’s (PCG) depressive symptoms and how their child’s perceived level of parent-child closeness is related to their now-adolescent’s (age 15) likelihood of ideation (N = 4,898 families). Results Hispanic PCG’s reported a lower rate of depressive symptoms (37%) than non-Hispanic PCG’s (45%). Hispanic PCG’s depressive symptoms were more likely to be chronic throughout their adolescent’s lifetime (15%). Regardless of race/ethnicity, PCG’s chronic depressive symptoms negatively affected parental closeness and increased suicidal risk for adolescents. These associations were found at ages 9 and 15 for non-Hispanic families, and at age 15 for Hispanic families. Limitations While this is an important first step, parental closeness and ideation can wax and wane. Asking teens about ideation before adolescence could have strengthened our study. Conclusions Suicide prevention must be family system focused, and not solely adolescent focused. Impressing upon individuals who serve children (i.e. teachers) and adults (i.e. physicians) to include yearly depression and suicide screens/assessments is crucial given PCG’s different wave presentations and how ideation can present as early as middle school.

Friction welding is being performed offshore in environments where arc welding may be difficult and where fatigue performance is critical. Friction welding underwater with Remotely Operated Vehicles (ROVs) can greatly reduce the cost of a project compared with using divers and arc welding because the support vessel, which is the major cost component in such an operation, is smaller. This paper describes two different programs of experimental work in which the fatigue endurance of friction welds were found to be better than that which could be expected from arc welded joints of similar geometry. The first program involved experimental work done with 25mm diameter steel bars. It found that, in the as-welded condition, friction welds have high fatigue strength. Residual stress measurements showed that this was due to a beneficial residual stress distribution in which compressive stresses are present at the surface adjacent to the failure site. Further evidence of this was obtained by subjecting some specimens to thermal stress relief. The fatigue strength of the stress relieved specimens was reduced compared with the as-welded joints but nevertheless the fatigue strength of these specimens was still high. The second program involved fatigue tests on friction stud welds in which the friction welding equipment was deployed offshore by divers or ROVs. The test specimens were made up of 19mm diameter studs friction welded onto structural steel plate. As with the first program, the specimens showed high fatigue endurance with results approximating to a DNV Class C1 curve. In some of the tests, the studs were preloaded in tension and results from specimens that were preloaded to the correct value specified for the joint were all stopped as run-outs, with specimens remaining unbroken.

Identification of the effect of mean stress for fatigue performance of the premium threaded connection for the OCTG pipes, was conducted via full-scale test. API standard material [grade L80-1] was used for the test. The nominal pipe outside diameter and wall thickness were 244.48 mm (9-5/8 inch) and 11.99 mm (0.472 inch), respectively. The fatigue life of the specimens tested with no mean stress was longer than that of the specimens tested with a tensile mean stress. Through-wall cracks were found at the imperfect thread area of the male embodiment, but the crack initiation site depended on the mean stress. However, the primary root cause of the failure on both mean stress levels can be regarded as the fretting fatigue. Fatigue life was also able to be estimated using modified Goodman relation.

The offshore environment contains many sources of cyclic loading. Standard design S-N curves, such as those in DNVGL-RP-C203, are usually assigned to ensure a particular design life can be achieved for a particular set of anticipated loading conditions. Girth welds are often the ‘weak link’ in terms of fatigue strength and so it is important to show that girth welds made using new procedures for new projects that are intended to be used in fatigue sensitive risers or flowlines do indeed have the required fatigue performance. Alternatively, designers of new subsea connectors, used for example in tendons for tension leg platforms, mooring applications or well-heads which will experience cyclic loading in service, also wish to verify the fatigue performance of their new designs. Often operators require contractors to carry out resonance fatigue tests on representative girth welds in order to show that girth welds made using new procedures qualify to the required design S-N curve. Operators and contractors must then interpret the results, which is not necessarily straightforward if the fatigue lives are lower than expected. Many factors influence a component’s fatigue strength so there is usually scatter in results obtained when a number of fatigue tests are carried out on real, production standard components. This scatter means that it is important first to carry out the right number of tests in order to obtain a reasonable understanding of the component’s fatigue strength, and then to interpret the fatigue test results properly. A working knowledge of statistics is necessary for both specifying the test programme and interpreting the test results and there is often confusion over various aspects of test specification and interpretation. This paper describes relevant statistical concepts in a way that is accessible to non-experts and that can be used, practically, by designers. The paper illustrates the statistical analysis of test data with examples of the ‘target life’ approach (that is now included in BS7608:2014 + A1) and the equivalent approach in DNVGL-RP-C203, which uses the stress modification factor. It gives practical examples to designers of a pragmatic method that can be used when specifying test programmes and interpreting the results obtained from tests carried out during qualification programmes, which for example, aim to determine whether girth welds made using a new procedure qualify to a particular design curve. It will help designers who are tasked with specifying test programmes to choose a reasonable number of test specimens and stress ranges, and to understand the outcome when results have been obtained.

P1 Impact of antioxidant-enriched nutrient bar supplementation on the serum antioxidant markers and physical fitness components of track and field athletes

Pipes that experience sour service need to resist that corrosive environment. One method for achieving corrosion resistance is by lining the inside of the pipe with a corrosion resistant alloy (CRA), such as stainless steel or a nickel based alloy. This has the advantage of being much cheaper than either making the pipe from the CRA or metallurgically bonding CRA to the pipe (ie clad pipe). Lined pipe is gaining popularity, and has so far been used successfully in applications where applied strain levels are low, however more data is needed on its fatigue strength and its behavior when subjected to high levels of applied strain. A Joint Industry Project (JIP), funded by Petrobras, BG Group, Saipem, Tenaris, Technip, Cladtek and HMC, was run by TWI Ltd and INTECSEA to investigate and generate data on CRA lined pipe. The JIP included full scale resonance fatigue testing, allowing the failure location of lined pipes to be investigated, development of an ultrasonic inspection procedure for lined pipe, small scale mechanical tests to generate materials data and calculation of stress intensity factors specific to the lined pipe geometry. This paper presents a summary of the work carried out. The significance of the paper is that it describes a body of work carried out in the field of CRA lined pipe, helping operators and those at the front-end engineering design (FEED) stage to choose lined pipe, with the resulting cost savings.

A clear understanding of how students view plagiarism is needed if the extensive efforts devoted to helping them engage in high-quality scholarship are to be worthwhile. There are a variety of views on this topic, but theoretical models to integrate the literature, take account of international differences and guide practitioners are limited. Using a large, international student sample, this paper presents just such a model. More than 2500 university students in the UK and Australia completed a questionnaire rating the perceived ‘seriousness' of various plagiarism-related actions in an individual assignment. Factor analysis identified three underlying themes: dishonest acts, poor referencing, and group work. Group comparisons indicated statistically significant differences in student understanding dependent on previous region of study, current faculty/school and level of study, with the former two emerging as more influential than the latter. This three-factor model provides practitioners with a methodology for integrating the many different studies in the area and gaining a broader overview of student understanding of plagiarism. In particular, it highlights how students consider plagiarism related to group work to be far less serious than other types. Given the increasing emphasis on group work in higher education, the implications of this for policy and practice are discussed. Importantly, the study also notes that effect sizes were small, suggesting that findings in this study, as in other studies, may not represent substantive differences in student perceptions. A single, universal approach to educating students about plagiarism may be as effective as approaches tailored to the individual's background.

The evaluation of teaching and learning has become an important activity in tertiary education institutions. Student surveys provide information about student perceptions and judgments of a particular subject. However, as is widely recognised, the appropriate interpretation of this data is problematic. There is a large literature, mainly for the US, on the use and usefulness of student subject evaluations. This literature has highlighted a number of ‘mitigating factors’ such as subject difficulty, discipline area, etc., that should be taken into account in interpreting the results of these questionnaires. In this paper we examine 8 years of QOT responses from an Economics Department in an Australian University which accounted for more than 79,000 student subject enrolments in 565 subjects. The purpose of this analysis is to establish how the information contained in these data can be used to interpret the responses. In particular, we determine to what extent other factors besides the instructor in charge of the subject have an impact on the raw average student evaluation scores. We find that the following characteristics of the students in these classes had an influence on the average QOT score: year level, enrolment size, the quantitative nature of the subject, the country of origin of the students, the proportion that are female, Honours status of the student, the differential in their mark from previous marks, quality of workbook, quality of textbook and the relative QOT score versus other subjects taught at the same time. However, a number of other factors proposed in the literature to be important influences were found not to be. These include the student’s fee paying status, whether they attended a public, private or catholic secondary school, which other faculty within the University they came from, and if the subject was taught in multiple sessions.

The results of the Course Experience Questionnaire (CEQ) in Australian tertiary institutions have been available for a number of years and have provided the administration of these institutions with valuable information as to students’ perceptions of their courses. In addition to the CEQ, all of these institutions survey their students at the subject level. The purpose of this study has been to determine the degree to which the responses recorded on these subject level Teaching Quality Indicators (TQI) are related to the CEQ. In the analysis, we have used two approaches to cast some light on the degree to which the responses on the TQI can be used to anticipate and establish responses on the subsequent CEQ.Prior to performing these studies, we first sampled the extensive literature that describes influences on responses to TQIs. From this survey, we found that there are many factors which influence students’ responses, other than a specific lecturer’s performance in class. We have used the literature on the TQIs because there is almost no literature concerning students’ responses to course level surveys such as the CEQ. Nonetheless we have used the results of this survey to determine how we can control for these factors when modeling responses to the CEQ.There were two major hurdles which needed to be addressed in the performance of this analysis across institutions. First, there is no consistent TQI for all institutions. Most of these surveys have been assembled using questions with different origins that have varied over time and that are individual to each institution. Secondly, even if the TQIs were constant and consistent across all institutions, it would be necessary to account for any other factors, such as the year level and the field of study, that may influence the specific subject TQIs and the overall course evaluation. Our first analysis addresses, in a systematic manner, the first difficulty by investigating the nature of the TQIs in use in Australian tertiary institutions. Through the use of a website designed as a clearing house for information on these surveys, we have collected examples of the TQIs from 39 higher education institutions in Australia. We then categorised these different instruments to develop a composite new TQI survey that captures the characteristics of those in use.Using the new TQI, we then compared the responses of students at the four participating institutions (Flinders, Melbourne, Tasmania, and Wollongong). The students were asked to respond to a survey that included questions relating to teaching, generic skills and overall course satisfaction (from the CEQ), questions from the local TQI, and questions from the new TQI based on the composite question types found in our analysis of all Australian TQIs. We found that few of the institution-specific TQI’s elicited responses that matched the CEQ and that even the new TQI did not provide many solid matches. Thus we concluded that, in most cases, the items on the TQI and the CEQ are measuring different factors.For the CEQ responses from The University of Melbourne, we matched the students’ experiences in order to determine the degree to which their responses could have been anticipated. From this analysis we found that those students who completed the CEQ were most responsive to situations where their expectations are not met. We also found that characteristics of subjects that influence TQI responses are also factors that influence CEQ responses. We found that older students, those that receive higher marks than their peers, and those who study full-time in their last year, are more likely to rate a course more highly. Whilst students who take more than one course, who are in subjects with higher than average enrollments, and that received lower than average TQI ratings, are less likely to rate their course highly.The conclusion from this study is that TQIs at different institutions are not designed in a consistent manner and that only a small portion of the CEQ responses could be predicted by these TQI. However, just as with the studies of the TQIs, we can establish that course characteristics such as: the level of the degree, the Faculty and Department in which the course was taken, the course description, the industry and duties of those who have found employment after completing their course, all strongly influence the CEQ.

We examine the association between student use of a unique, interactive, on-line learning system known as MarlinaLS™ and the learning outcomes achieved by students in a major second year undergraduate accounting subject over the period 2002–2003. Primarily, we explore the relationship between students’ use of MarlinaLS™, an on-line system developed specifically to enhance reciprocal learning, and the examination performance of those students. Our results show that students’ use of MarlinaLS™ is positively associated with their examination performance and also with the internal assessment result achieved. We also find that the extent of usage of the MarlinaLS™ system by students varies systematically based on a number of defined characteristics. The study enhances our understanding of the role of teaching strategies generally, and, more specifically, the role of interactive on-line learning systems in improving student learning outcomes.

Purpose The purpose of this study was to test the hypothesis that spatial and temporal localization of growth factors FGF-2 and VEGF in a rabbit tooth extraction socket model correlate with the histologic events of healing. Materials and Methods Twenty-four male New Zealand white rabbits divided into 8 groups of 3 were used in the study. Incisor teeth were extracted from both jaws and the healing extraction socket with surrounding jaw bone was harvested at 48 hours, 4 days, 1, 2, 4, 8, 12, and 16 weeks. Tissues were fixed, decalcified, and processed for hematoxylin-eosin and immunohistochemical staining. The sections were stained to detect FGF-2 and VEGF. The stained sections were then imaged and an automated computer program was used to detect the brown diaminobenzidine stain that represented the growth factors of interest. Data was obtained in the form of percentage area and intensity of stain and analyzed using the analysis of variance (ANOVA - Tukey Kramer and Scheffe’s post-test). Results Spatial and temporal differences in localization of FGF-2 and VEGF were observed across all time frames in both jaws. Statistically significant differences in percentage area and intensity of brown diaminobenzidine stain were seen temporally between FGF-2 and VEGF (P Conclusion The results of this study showed positive correlation of histologic events to spatial and temporal localization of FGF-2 and VEGF in a rabbit tooth extraction model.

Greller, A.M. (Department of Biology, Queens College, CUNY, Flushing, NY 11367; and Department of Science, Brooklyn Botanic Garden, 1000 Washington Ave., Brooklyn, NY 11225), G. E. Lotowycz (Planting Fields Herbarium and Library, Planting Fields Arboretum, P.O. Box 58, Oyster Bay, NY 11771), G. Moore (Department of Science, Brooklyn Botanic Garden, 1000 Washington Avenue, Brooklyn, NY 11225), E. Lamont (New York Botanical Garden, Bronx, NY 10458), H. Binger (Department of Biology, Queens College, CUNY, Flushing, NY 11367), B. Conolly (Long Island Botanical Society, P.O. Box 507, Aquebogue, NY 11931), V. Dankel (Department of Biology, Queens College, CUNY, Flushing, NY 11367), J. Hoar (Caumsett Foundation, Caumsett State Park, Lloyd harbor, Huntington, NY 11743), C. Johnston (Planting Fields Herbarium and Library, Planting Fields Arboretum, P.O. Box 58, Oyster Bay, NY 11771), A. Mangiacapre (Department of Biology, Queens College, CUNY, Flushing, NY 11367), J. Schmidt (Department of Biology, Queens...

Recent calls have been made for a fundamental reorientation in higher education from a curriculum that simply transmits information (learner as receiver) to one that encourages students actively to construct their own knowledge and practice using new skills and concepts (learner as constructor). In response, the Case Analysis in Organisational Situations (CAOS) assessment tool was developed for use in teaching organisational behaviour. It follows the principles of problem‐based learning and group work, using an unfolding case design. A pre‐test (n=365), immediate post‐test (n=323) and delayed post‐test (n=129) design was implemented to evaluate the effectiveness of this new learning tool. The assessment of student approaches to learning revealed that students were more likely to adopt a deep approach to learning at the end of CAOS than at the beginning. In general, the results show that CAOS is a useful web‐based tool that promotes learning in organisational behaviour. The benefits of CAOS and some sugges...

Angiogenic therapies have been designed for many pathological conditions, but when used as a single therapy, the clinical results have fallen short of expectations. In addition, strategies for vascularizing engineered tissues have been unsuccessful in promoting the formation of an extensive, stable vasculature. Recent evidence suggests that mural cells play a critical role in the success of these approaches, but our current understanding of the function of mural cells in the microvasculature is incomplete. We studied the three-dimensional spatial and temporal kinetics of the mural cell markers desmin and smooth muscle alpha actin during angiogenesis in an in vivo fibrin gel model. The results led to the following conclusions: (1) desmin and smooth muscle alpha actin positive cells are present during the initial development of vessel sprouts; (2) the presence of these cells in the microvasculature is not always an indicator of vessel stability; and (3) the mural cell markers desmin and smooth muscle alpha actin exhibit differential staining patterns during vessel formation. These findings shed new light on the complexity of the relationship between mural cells and the formation of a mature, stable microcirculation.

In this work we sought to understand the effect of biomaterial properties upon healing bone tissue. We hypothesized that a hydrophilic polymer gel implanted into a bone tissue defect would impede the healing process owing to the biomaterial's prevention of protein adsorption and thus cell adhesion. To test this hypothesis, healing bone was investigated within a rabbit incisor extraction socket, a subcritical size bone defect that resists significant soft tissue invasion by virtue of its conformity. After removal of the incisor teeth, one tooth socket was left as an empty control, one was filled with crosslinked polymer networks formed from the hydrophobic polymer poly(propylene fumarate) (PPF), and one was filled with a hydrogel formed from the hydrophilic oligomer oligo(poly(ethylene glycol) fumarate) (OPF). At five different times (4 days as well as 1, 2, 4, and 8 weeks), jaw bone specimens containing the tooth sockets were removed. We analyzed bone healing by histomorphometrical analysis of hematoxylin and eosin stained sections as well as immunohistochemically stained sections. The proposed hypothesis, that a hydrophilic material would hinder bone healing, was supported by the histomorphometrical results. In addition, the immunohistochemical results reflect molecular signaling indicative of the early invasion of platelets, the vascularization of wound-healing tissue, the differentiation of migrating progenitor cells, and the formation and remodeling of bone tissue. Finally, the results emphasize the need to consider biomaterial properties and their differing effects upon endogenous growth factors, and thus bone healing, during the development of tissue engineering devices.

Although the combination of radiation and tissue expansion has been associated with a significant rate of complications, the specific pathophysiology has yet to be clearly elucidated. The objective of this study was to develop a model to identify and examine specific histologic changes associated with tissue expansion and irradiation. Rectangular 50-cc silicone tissue expanders were placed subcutaneously over the midline dorsum of 18 adult New Zealand white rabbits. Preoperative radiographic dosimetry demonstrated that the radiation portal was away from vital intraabdominal structures. The expanders were inflated with 10 cc of saline every other day for a total of 80 cc. Expanders were left in place for 2 to 3 weeks to allow fibrovascular capsule formation. The rabbits were then divided into three groups (six rabbits per group), each receiving one of three nonfractionated doses of radiation (20, 25, or 35 Gy). Half of the expanded skin was irradiated using a single dose, and the other half served as a nonirradiated control. Capsules and skin were harvested 6 weeks after the delivery of radiation, allowing the beginning of chronic radiation changes to occur. Using hematoxylin and eosin staining, histomorphometric analysis was performed. The data were analyzed using Student's test. Although irradiation did not affect dermal thickness, it did cause a statistically significant increase in epidermal thickness. At 20, 25, and 35 Gy the increase in epidermal thickness was 43, 90, and 130 percent, respectively. Although significant epidermal changes could be identified, capsular and dermal alterations were not evident. Further studies evaluating the long-term effects of alterations in capsular formation caused by radiation may be required.

Studies were performed in a long-term effort to develop clinically translatable, tissue engineered adipose constructs for reconstructive, correctional, and cosmetic indications. Rat preadipocytes were harvested, isolated, expanded ex vivo, and seeded within PLGA scaffolds. Preadipocyte-seeded and acellular (control) scaffolds were implanted for 1-12 months. Explanted scaffolds were stained with osmium tetroxide, processed, and counterstained using HE. Quantitative histomorphometric analysis was performed on all tissue sections to determine the amount of adipose tissue formed. Analyses revealed maximum adipose formation at 2 months, followed by a decrease at 3 months, and complete absence of adipose and PLGA at 5-12 months. These results extend a previous short-term study (Tissue Engineering 1999;5:134) and demonstrate that adipose tissue can be formed in vivo using tissue engineering strategies. However, the long-term maintenance of adipose tissue remains elusive.

The article outlines and evaluates a new learning strategy implemented in the Faculty of Economics and Commerce at the University of Melbourne. The strategy is an internet-based assignment delivery and assessment system designed to (i) equip students to make the link between macro economic theory and important real-world issues, (ii) develop positive attitudes to the subject, (iii) develop deep approaches to learning, (iv) develop a facility for critical analysis and problem-solving, and (v) develop effective study habits. Using a multidimensional evaluation strategy, the indications are that the new approach has succeeded in its aims.

Contrary to the assertions of many contemporary economists, no economic model is "value-free." Both of the major models in the world today, capitalism (or neoclassical economic theory) and Marxism (or Marxian economics), have a long history in which basic assumptions and value choices were made that govern the models. Those assumptions and value choices have deep roots in Western culture, and were certainly shaped by Christianity as it has been practiced in the West (as opposed, often, to how it should have been practiced!). But in both cases, alternative choices were possible, and, as we shall see, some opportunities were missed. However, it is not my purpose to attempt to determine to what extent Christianity can be blamed or credited with the economics we must live with today. Rather, I hope to examine economics from the perspective of my Christian faith to ask how the economic models so powerful today have missed (or worked against) crucial elements of Jewish and Christian standards of justice, and how they might be transformed to create economies that are healthier for human and natural communities, and ecologically sustainable. When Adam Smith published his Inquiry into the Nature and Causes of the Wealth ofNations in 1776, he was asking if there could be a better way to run economies than the entrenched mercantilism of his day, which operated through state monopolies to benefit an elite. He and many others in his time were frustrated with mercantilism and searching for alternatives. They never imagined that the ideas they wrote about would some day coalesce into what we now call "capitalism," and succeed beyond their wildest dreams. They were just trying to make the system more open to more participation by a wider range of people. I believe that today we are in a similar situation. Capitalism has been wildly successful in its single goal: constant growth in the production of "goods." From a Christian perspective, this is an ambiguous goal and in and of itself cannot be supported. In addition, capitalism also has serious negative effects on both communities and the natural environment that must be dealt with, and it has a built-in tendency to leave many people marginalized-not only unemployed and often unemployable within the capitalist market system, but even worse

This article examines the perceptions and experiences of first year students in an Economics and Commerce Faculty. First year Bachelor of Commerce students responded to pre- and post- university experience surveys of their approaches to learning and experience of the learning environment in the faculty. Students' responses indicated a slide into surface learning during their first year and indicated that their expectations of learning at the university level were not realised. English speaking background (ESB) and nonEnglish speaking background (NESB) students were compared. While few differences between the two groups were identified a slight preference for social forms of learning and deeper approaches to learning were observed for NESB students. The implications of the findings for first year teaching are discussed.

Reports on a study in a system of public education that is widely believed to be at the forefront of efforts to create world class schools. The aim of the study, thought to be the first of its kind, was to determine the extent to which five disciplines in the Senge model of a learning organisation are apparent in management practices of schools within the system. Concludes that Senge’s model of a learning organisation provides a helpful template for conceptualising progress towards world class schools. Implications for leadership are identified as an avenue through which to energise the quest for world class schools.

The authors provide an overview of papers presented at The Scholarship of Teaching Economics conference that was held at The University of Melbourne in July 2000. The objective of the conference was to bring attention to research being conducted in economic education at the tertiary level and to engage academic economists in discussion about the scholarship of teaching economics. The presentations of seven of the keynote speakers are discussed using the framework of who, what, and how of teaching economics. Who should determine the curriculum? What should be taught? And how should it be taught?

In this article, we describe and evaluate a package of measures designed to introduce a collaborative, problem-solving (CPS) approach to learning into the tutorials of a second-year university macroeconomics subject. These findings are derived from a comparison of a trial group of 311 students and a control group of 301 students, each drawn randomly from students enrolled in a single subject, at a single institution, the University of Melbourne. To learn economics successfully, students need to have ability in both abstract thinking and in application. They also need to be able to express complex ideas logically and fluently. The development of these diverse aspects of thinking is challenging for students in their early undergraduate years and may be one reason why students often view economics as a difficult subject. The 1995 CPS project was a pilot for a wider departmental initiative designed to enhance the role of tutorials (one-hour classes of about 20 students led by a tutor) in the teaching and learning process. The project embodied two major components: problem-based learning and collaborative learning. Both these components were thought to be potentially valuable for undergraduate students

Efficiency considerations have led to increased use of multiple-choice questions to assess economics understanding at the secondary and tertiary levels throughout Australia. A multiple-choice test would suffice if multiple-choice and essay questions measure the same dimensions of knowledge, as suggested by least squares estimation of the relationship between these two forms of testing. We show a simultaneous equation bias inherent in least squares estimation of the relationship between these two forms. A two-stage least squares estimation reveals no relationship, implying that these testing forms measure different dimensions of knowledge. Thus, a single form of testing economics knowledge must be avoided.

Residual stresses (RS) are unavoidably generated in components after welding. Tensile residual stresses in engineering structures generally have an adverse effect on structural integrity, with detrimental effects on brittle fracture, corrosion properties and fatigue performance. Residual stress measurements for offshore welded joints are generally very limited. In this study, experimental measurements and numerical modelling of residual stresses were carried out and the through-thickness residual stress distributions in circumferential butt welds are presented. Pipes of two different dimensions and steels were investigated: a seamless X70 steel pipe with an outside diameter of 406mm and a seam-welded X65 steel with an outside diameter of 508mm. The measurement methods used included the centrehole air abrasion drilling, the deep-hole drilling (DHD) and the block removal, splitting and layering (BRSL). The numerical modelling was undertaken to determine whether modelling could provide a satisfactory prediction of the final residual stresses. Finally, the new experimental data were combined with the BS 7910 database to derive revised upper bound through-thickness residual stress distributions for girth welds and to provide an assessment of the impact of residual stresses on the structural integrity of circumferential welds in offshore structures.

Carotid artery plaque instability can result in rupture and lead to ischaemic stroke. Stability of plaques appears to be a function of composition. Current non-invasive imaging techniques are limited in their ability to classify distinct histological regions within plaques. Phase-contrast (PC) X-ray imaging methods are an emerging class of techniques that have shown promise for identifying soft-tissue features without use of exogenous contrast agents. This is the first study to apply analyser-based X-ray PC imaging in CT mode to provide three-dimensional (3D) images of excised atherosclerotic plaques. The results provide proof of principle for this technique as a promising method for analysis of carotid plaque microstructure. Multiple image radiography CT (MIR-CT), a tomographic implementation of X-ray PC imaging that employs crystal optics, was employed to image excised carotid plaques. MIR-CT imaging yields three complementary images of the plaque's 3D X-ray absorption, refraction and scatter properties. These images were compared with histological sections of the tissue. X-ray PC images were able to identify the interface between the plaque and the medial wall. In addition, lipid-rich and highly vascularized regions were visible in the images as well as features depicting inflammation. This preliminary research shows MIR-CT imaging can reveal details about plaque structure not provided by traditional absorption-based X-ray imaging and appears to identify specific histological regions within plaques. This is the first study to apply analyser-based X-ray PC imaging to human carotid artery plaques to identify distinct soft-tissue regions.

Hydroxychloroquine (HCQ) is a racemic antiarthritic agent that has a long half-life (t1/2) in plasma and accumulates in blood cells. To study the relationships between HCQ concentrations in plasma, serum, and whole blood and to determine the optimal blood fraction to use for therapeutic drug monitoring of the drug, we studied the relative distribution of the HCQ enantiomers in various fractions of human blood under in vivo and in vitro conditions. Substantially greater concentrations of both enantiomers were found in serum as compared with plasma because of release via platelet activation. After in vitro incubations of the separated blood cells with HCQ, high concentrations of both enantiomers were found in leukocytes, and low concentrations in erythrocytes and platelets; the R:S ratio in vitro was near unity in all of the cells examined. Unlike the in vitro cellular uptake, the concentrations of HCQ in vivo were significantly lower and stereoselective (R:S ratio = 2). There was almost no drug in the polymorphonuclear cells (PMN) in vivo, despite a substantial uptake in vitro after incubation of separated cells. The enantiomeric (R:S) ratio in the urinary excretion of the enantiomers was significantly correlated with that in plasma. The plasma-protein binding of the enantiomers was stereoselective and complimented the cellular uptake findings; the unbound fraction was dependent on the plasma concentrations of alpha 1-acid glycoprotein, but not albumin. Although concentrations in whole blood correlated well with those in lymphocytes and monocytes (the proposed site of HCQ action), stronger correlations were found between concentrations in serum and in the mononuclear cells.