bluuebunny/crossref_metadata_2025 huggingface dataset:
High rate of failure of impaction grafting in large acetabular defects
Authors: van Haaren E. H. , Heyligers I. C. , Alexander F. G. M. , Wuisman P. I. J. M.
Published: March 2007

We reviewed the results of 71 revisions of the acetabular component in total hip replacement, using impaction of bone allograft. The mean follow-up was 7.2 years (1.6 to 9.7). All patients were assessed according to the American Academy of Orthopedic Surgeons (AAOS) classification of bone loss, the amount of bone graft required, thickness of the graft layer, signs of graft incorporation and use of augmentation.

A total of 20 acetabular components required re-revision for aseptic loosening, giving an overall survival of 72% (95% CI, 54.4 to 80.5). Of these failures, 14 (70%) had an AAOS type III or IV bone defect. In the failed group, poor radiological and histological graft incorporation was seen.

These results suggest that impaction allografting in acetabular revision with severe bone defects may have poorer results than have previously been reported.
Monteggia fractures in adults
Authors: Konrad G. G. , Kundel K. , Kreuz P. C. , Oberst M. , Sudkamp N. P.
Published: March 2007

The objective of this retrospective study was to correlate the Bado and Jupiter classifications with long-term results after operative treatment of Monteggia fractures in adults and to determine prognostic factors for functional outcome. Of 63 adult patients who sustained a Monteggia fracture in a ten-year period, 47 were available for follow-up after a mean time of 8.4 years (5 to 14). According to the Broberg and Morrey elbow scale, 22 patients (47%) had excellent, 12 (26%) good, nine (19%) fair and four (8%) poor results at the last follow-up. A total of 12 patients (26%) needed a second operation within 12 months of the initial operation. The mean Broberg and Morrey score was 87.2 (45 to 100) and the mean DASH score was 17.4 (0 to 70). There was a significant correlation between the two scores (p = 0.01). The following factors were found to be correlated with a poor clinical outcome: Bado type II fracture, Jupiter type IIa fracture, fracture of the radial head, coronoid fracture, and complications requiring further surgery.

Bado type II Monteggia fractures, and within this group, Jupiter type IIa fractures, are frequently associated with fractures of the radial head and the coronoid process, and should be considered as negative prognostic factors for functional long-term outcome. Patients with these types of fracture should be informed about the potential risk of functional deficits and the possible need for further surgery.
High-energy extracorporeal shock-wave therapy for calcifying tendinitis of the rotator cuff
Authors: Albert J.-D. , Meadeb J. , Guggenbuhl P. , Marin F. , Benkalfate T. , Thomazeau H. , Chalès G.
Published: March 2007

In a prospective randomised trial of calcifying tendinitis of the rotator cuff, we compared the efficacy of dual treatment sessions delivering 2500 extracorporeal shock waves at either high- or low-energy, via an electromagnetic generator under fluoroscopic guidance. Patients were eligible for the study if they had more than a three-month history of calcifying tendinitis of the rotator cuff, with calcification measuring 10 mm or more in maximum dimension. The primary outcome measure was the change in the Constant and Murley Score.

A total of 80 patients were enrolled (40 in each group), and were re-evaluated at a mean of 110 (41 to 255) days after treatment when the increase in Constant and Murley score was significantly greater (t-test, p = 0.026) in the high-energy treatment group than in the low-energy group. The improvement from the baseline level was significant in the high-energy group, with a mean gain of 12.5 (−20.7 to 47.5) points (p < 0.0001). The improvement was not significant in the low-energy group. Total or subtotal resorption of the calcification occurred in six patients (15%) in the high-energy group and in two patients (5%) in the low-energy group.

High-energy shock-wave therapy significantly improves symptoms in refractory calcifying tendinitis of the shoulder after three months of follow-up, but the calcific deposit remains unchanged in size in the majority of patients.
Interbody fusion with allograft and rhBMP-2 leads to consistent fusion but early subsidence
Authors: Vaidya R , Weir R. , Sethi A. , Meisterling S. , Hakeos W. , Wybo C. D.
Published: March 2007

We carried out a prospective study to determine whether the addition of a recombinant human bone morphogenetic protein (rhBMP-2) to a machined allograft spacer would improve the rate of intervertebral body fusion in the spine. We studied 77 patients who were to undergo an interbody fusion with allograft and instrumentation. The first 36 patients received allograft with adjuvant rhBMP-2 (allograft/rhBMP-2 group), and the next 41, allograft and demineralised bone matrix (allograft/demineralised bone matrix group). Each patient was assessed clinically and radiologically both pre-operatively and at each follow-up visit using standard methods. Follow-up continued for two years.

Every patient in the allograft/rhBMP-2 group had fused by six months. However, early graft lucency and significant (> 10%) subsidence were seen radiologically in 27 of 55 levels in this group. The mean graft height subsidence was 27% (13% to 42%) for anterior lumbar interbody fusion, 24% (13% to 40%) for transforaminal lumbar interbody fusion, and 53% (40% to 58%) for anterior cervical discectomy and fusion. Those who had undergone fusion using allograft and demineralised bone matrix lost only a mean of 4.6% (0% to 15%) of their graft height.

Although a high rate of fusion (100%) was achieved with rhBMP-2, significant subsidence occurred in more than half of the levels (23 of 37) in the lumbar spine and 33% (6 of 18) in the cervical spine. A 98% fusion rate (62 of 63 levels) was achieved without rhBMP-2 and without the associated graft subsidence. Consequently, we no longer use rhBMP-2 with allograft in our practice if the allograft has to provide significant structural support.
The effect of the design of the femoral component on the conformity of the patellofemoral joint in total knee replacement
Authors: Ma H.-M. , Lu Y.-C. , Kwok T.-G. , Ho F.-Y. , Huang C.-Y. , Huang C.-H.
Published: March 2007

One of the most controversial issues in total knee replacement is whether or not to resurface the patella. In order to determine the effects of different designs of femoral component on the conformity of the patellofemoral joint, five different knee prostheses were investigated. These were Low Contact Stress, the Miller-Galante II, the NexGen, the Porous-Coated Anatomic, and the Total Condylar prostheses. Three-dimensional models of the prostheses and a native patella were developed and assessed by computer. The conformity of the curvature of the five different prosthetic femoral components to their corresponding patellar implants and to the native patella at different angles of flexion was assessed by measuring the angles of intersection of tangential lines.

The Total Condylar prosthesis had the lowest conformity with the native patella (mean 8.58°; 0.14° to 29.9°) and with its own patellar component (mean 11.36°; 0.55° to 39.19°). In the other four prostheses, the conformity was better (mean 2.25°; 0.02° to 10.52°) when articulated with the corresponding patellar component. The Porous-Coated Anatomic femoral component showed better conformity (mean 6.51°; 0.07° to 9.89°) than the Miller-Galante II prosthesis (mean 11.20°; 5.80° to 16.72°) when tested with the native patella. Although the Nexgen prosthesis had less conformity with the native patella at a low angle of flexion, this improved at mid (mean 3.57°; 1.40° to 4.56°) or high angles of flexion (mean 4.54°; 0.91° to 9.39°), respectively. The Low Contact Stress femoral component had the best conformity with the native patella (mean 2.39°; 0.04° to 4.56°). There was no significant difference (p > 0.208) between the conformity when tested with the native patella or its own patellar component at any angle of flexion.

The geometry of the anterior flange of a femoral component affects the conformity of the patellofemoral joint when articulating with the native patella. A more anatomical design of femoral component is preferable if the surgeon decides not to resurface the patella at the time of operation.
Correction of neglected idiopathic club foot by the Ponseti method
Authors: Lourenço A. F. , Morcuende J. A.
Published: March 2007

The Ponseti method of treating club foot has been shown to be effective in children up to two years of age. However, it is not known whether it is successful in older children. We retrospectively reviewed 17 children (24 feet) with congenital idiopathic club foot who presented after walking age and had undergone no previous treatment. All were treated by the method described by Ponseti, with minor modifications. The mean age at presentation was 3.9 years (1.2 to 9.0) and the mean follow-up was for 3.1 years (2.1 to 5.6). The mean time of immobilisation in a cast was 3.9 months (1.5 to 6.0).

A painless plantigrade foot was obtained in 16 feet without the need for extensive soft-tissue release and/or bony procedures. Four patients (7 feet) had recurrent equinus which required a second tenotomy. Failure was observed in five patients (8 feet) who required a posterior release for full correction of the equinus deformity.

We conclude that the Ponseti method is a safe, effective and low-cost treatment for neglected idiopathic club foot presenting after walking age.
Complex regional pain syndrome with special emphasis on the knee
Authors: Dowd G. S. E. , Hussein R. , Khanduja V. , Ordman A. J.
Published: March 2007

Complex regional pain syndrome is characterised by an exaggerated response to injury in a limb with intense prolonged pain, vasomotor disturbance, delayed functional recovery and trophic changes. This review describes the current knowledge of the condition and outlines the methods of treatment available with particular emphasis on the knee.
Accuracy analysis of Iso-C3D versus fluoroscopy-based navigated retrograde drilling of osteochondral lesions
Authors: Citak M. , Kendoff D. , Kfuri M. , Pearle A. , Krettek C. , Hüfner T.
Published: March 2007

The aim of this pilot study was to evaluate the accuracy of two different methods of navigated retrograde drilling of talar lesions. Artificial osteochondral talar lesions were created in 14 cadaver lower limbs. Two methods of navigated drilling were evaluated by one examiner. Navigated Iso-C3D was used in seven cadavers and 2D fluoroscopy-based navigation in the remaining seven. Of 14 talar lesions, 12 were successfully targeted by navigated drilling. In both cases of inaccurate targeting the 2D fluoroscopy-based navigation was used, missing lesions by 3 mm and 5 mm, respectively. The mean radiation time was increased using Iso-C3D navigation (23 s; 22 to 24) compared with 2D fluoroscopy-based navigation (14 s, 11 to 17).
Adamantinoma of the tibia with late skeletal metastasis
Authors: Kanakaraddi S. V. , Nagaraj G. , Ravinath T. M.
Published: March 2007

Adamantinoma is a rare tumour of long bones that occurs most commonly in the tibia. Its pathogenesis is unknown. It is locally aggressive and recurrences are common after resection. Metastases have been reported in 10% to 20% of cases, most commonly in the lungs and rarely in the lymph nodes. We report a patient who developed a skeletal metastasis four years after resection of the primary tumour. There was no evidence of recurrence at the primary site or of secondary deposits in the lungs.
GSB III total elbow replacement in rheumatoid arthritis
Authors: Cesar M. , Roussanne Y. , Bonnel F. , Canovas F.
Published: March 2007

Between 1993 and 2002, 58 GSB III total elbow replacements were implanted in 45 patients with rheumatoid arthritis by the same surgeon. At the most recent follow-up, five patients had died (five elbows) and six (nine elbows) had been lost to follow-up, leaving 44 total elbow replacements in 34 patients available for clinical and radiological review at a mean follow-up of 74 months (25 to 143). There were 26 women and eight men with a mean age at operation of 55.7 years (24 to 77).

At the latest follow-up, 31 excellent (70%), six good (14%), three fair (7%) and four poor (9%) results were noted according to the Mayo elbow performance score. Five humeral (11%) and one ulnar (2%) component were loose according to radiological criteria (type III or type IV). Of the 44 prostheses, two (5%) had been revised, one for type-IV humeral loosening after follow-up for ten years and one for fracture of the ulnar component. Seven elbows had post-operative dysfunction of the ulnar nerve, which was transient in five and permanent in two.

Despite an increased incidence of loosening with time, the GSB III prosthesis has given favourable mid-term results in patients with rheumatoid arthritis.
Transplacental transfer of cobalt and chromium in patients with metal-on-metal hip arthroplasty
Authors: Ziaee H. , Daniel J. , Datta A. K. , Blunt S. , McMinn D. J. W.
Published: March 2007

Metal-on-metal bearings are being increasingly used in young patients. The potential adverse effects of systemic metal ion elevation are the subject of ongoing investigation. The purpose of this study was to investigate whether cobalt and chromium ions cross the placenta of pregnant women with a metal-on-metal hip resurfacing and reach the developing fetus. Whole blood levels were estimated using high-resolution inductively-coupled plasma mass spectrometry.

Our findings showed that cobalt and chromium are able to cross the placenta in the study patients with metal-on-metal hip resurfacings and in control subjects without any metal implants. In the study group the mean concentrations of cobalt and chromium in the maternal blood were 1.39 μg/l (0.55 to 2.55) and 1.28 μg/l (0.52 to 2.39), respectively. The mean umbilical cord blood concentrations of cobalt and chromium were comparatively lower, at 0.839 μg/l (0.42 to 1.75) and 0.378 μg/l (0.14 to 1.03), respectively, and this difference was significant with respect to chromium (p < 0.05).

In the control group, the mean concentrations of cobalt and chromium in the maternal blood were 0.341 μg/l (0.18 to 0.54) and 0.199 μg/l (0.12 to 0.33), and in the umbilical cord blood they were 0.336 μg/l (0.17 to 0.5) and 0.194 μg/l (0.11 to 0.56), respectively. The differences between the maternal and umbilical cord blood levels in the controls were marginal, and not statistically significant (p > 0.05). The mean cord blood level of cobalt in the study patients was significantly greater than that in the control group (p < 0.01). Although the mean umbilical cord blood chromium level was nearly twice as high in the study patients (0.378 μg/l) as in the controls (0.1934 μg/l), this difference was not statistically significant. (p > 0.05)

The transplacental transfer rate was in excess of 95% in the controls for both metals, but only 29% for chromium and 60% for cobalt in study patients, suggesting that the placenta exerts a modulatory effect on the rate of metal ion transfer.
Remodelling of the distal radius after epiphysiolysis and lengthening
Authors: Ok I.-Y. , Kim S.-J.
Published: March 2007

Arrest of growth of the distal radius is rare but will produce deformity of the wrist. We corrected angular deformity and shortening of the distal radius by epiphysiolysis and gradual lengthening without a corrective osteotomy.
Intertrochanteric fracture of an arthrodesed hip
Authors: Manzotti A. , Confalonieri N. , Pullen C.
Published: March 2007

We report the case of a 74-year-old woman who sustained an intertrochanteric fracture of the femoral neck in a previously arthrodesed hip. The hip arthrodesis had been performed 53 years earlier to treat septic arthritis. The fracture was treated successfully using a double-plating technique with 4.5 mm titanium reconstruction plates.
Giant-cell tumour of the knee
Authors: von Steyern F. Vult , Kristiansson I. , Jonsson K. , Mannfolk P. , Heineg̊rd D. , Rydholm A.
Published: March 2007

We reviewed nine patients at a mean period of 11 years (6 to 16) after curettage and cementing of a giant-cell tumour around the knee to determine if there were any long-term adverse effects on the cartilage. Plain radiography, MRI, delayed gadolinium-enhanced MRI of the cartilage and measurement of the serum level of cartilage oligomeric matrix protein were carried out. The functional outcome was evaluated using the Lysholm knee score.

Each patient was physically active and had returned to their previous occupation. Most participated in recreational sports or exercise.

The mean Lysholm knee score was 92 (83 to 100). Only one patient was found to have cartilage damage adjacent to the cement. This patient had a history of intra-articular fracture and local recurrence, leading to degenerative changes.

Interpretation of the data obtained from delayed gadolinium-enhanced MRI of the cartilage was difficult, with variation in the T1 values which did not correlate with the clinical or radiological findings. We did not find it helpful in the early diagnosis of degeneration of cartilage. We also found no obvious correlation between the serum cartilage oligomeric matrix protein level and the radiological and MR findings, function, time after surgery and the age of the patient.

In summary, we found no evidence that the long-term presence of cement close to the knee joint was associated with the development of degenerative osteoarthritis.
Heritability of blood pressure increases during mental stress
Authors: Boomsma DI , Snieder H , de Geus EJC , van Doornen LJP
Published: March 2007

We studied the influence of mental stress on the contributions of genes and environment to individual variation in systolic (SBP) and diastolic (DBP) blood pressure by structural equation modelling in 320 adolescent male and female twins. Blood pressure data were collected during rest and during a reaction time and a mental arithmetic task. Univariate analyses of SBP and DBP showed familial aggregation for blood pressure. A genetic explanation for this resemblance was most likely, although during rest conditions a model that attributed familial resemblance to shared environmental factors, also fitted the data. There was no evidence for sex differences in heritabilities. Multivariate analyses showed significant heterogeneity between sexes for the intercorrelations of the blood pressure data measured under different rest and task conditions. Multivariate genetic analyses were therefore carried out separately in males and females. For SBP and DBP in females and for SBP in males an increase in heritabilities was seen for blood pressure measured during stress, as compared to rest measurements. The influence of shared environ-mental factors decreased during stress. For DBP in males no significant contributions of shared environment were found. The multivariate analyses indicated that the same genetic and environmental influences are expressed during rest and stress conditions.
Quantitative genetic analysis of Internalising and Externalising Problems in a large sample of 3-year-old twins
Authors: van der Valk JC , Verhulst FC , Stroet TM , Boomsma DI
Published: March 2007

For a quantitative genetic study of pre-school problem behaviours, we have collected data with the Child Behavior Checklist for 2 and 3-year-old children (CBCL 2/3). Questionnaires were completed by mothers of 3620 twin pairs: 633 monozygotic males, 581 dizygotic males, 695 monozygotic females, 519 dizygotic females and 1192 dizygotic opposite sex twin pairs. The genetic and environmental influences on the Externalising and Internalising Problem scales were estimated, simultaneously with sex differences and sibling interaction effects. Genetic factors explained most of the observed variance for both Externalising and Internalising Problems. Cooperative sibling interactions were found for Externalising Problems, indicating that twins reinforce each other's behaviour. Sex differences in genetic architecture were found for Externalising Problems. Genetic factors explained 75% of the variance in girls and 50% in boys. Shared environmental influences were only of importance in boys. For both problem scales, non-shared environmental factors accounted for 25 to 32% of the variance. The observed variances of Internalising Problems could be adequately explained by genetic and nonshared environmental factors, with genetic factors accounting for 68% of the variance.
Models for the longitudinal genetic analysis of same-age twins: application to HDL cholesterol
Authors: Nance WE , Bodurtha J , Eaves LJ , Hewitt J , Maes H , Segrest J , Meyer J , Neale M , Schieken R
Published: March 2007

Models are presented for the analysis of longitudinal data from same-age twins which permit the exploration of a remarkably diverse array of alternative explanations for continuity and change during development. Data of this type permit the detection of new sources of genetic or environmental covariation during development that are not expressed at earlier ages and, because they include the effects of age-specific genes, the resulting heritability estimates are more reliable than those obtained from relatives who differ in age. The proposed models were applied to measurements of HDL cholesterol obtained on 81 pairs of monozygotic (MZ) twins and 69 dizygotic (DZ) pairs at 11, 12.5 and 14 years of age. All three MZ co-twin correlations were substantially higher than the self correlations across occasions, suggesting that new sources of genetic or environmental covariation must be expressed during early adolescence. This interpretation was confirmed by analysis of the full covariance matrices which showed that only models which assumed the expression of new or age-specific genes could explain the observed pattern of covariation. Because they include the effects of age-specific genes, the resulting heritabilities (0.80–0.83) were substantially higher than many previous estimates.
Twin registers in Europe: an overview
Authors: Boomsma Dorret I
Published: March 2007

This paper is the first in a series that aims to give an overview of existing twin registers worldwide. A short description of 16 registries in nine European countries is presented. These registries have access to over 350 000 pairs and a resource for genetic–epidemiological research.
A factor analysis of associations among self-reported immune related symptoms in a large twin sample
Authors: Duffy David L , Battistutta Diana , Mathews John D , Martin Nicholas G
Published: March 2007

We examined the cumulative prevalences of 22 symptoms thought to reflect immune system function reported in a questionnaire mailed to 7616 Australian twins. The associations between symptoms and demographic variables were expressed in terms of polychoric or polyserial correlations, and a principal components analysis performed. Factors representing underlying propensities respectively to allergic disease, various minor infections, diseases associated with aging such as arthritis, skin disease, and respiratory tract infection were extracted. Possible processes underlying these symptom clusters and the relative strengths and weaknesses of this type of analysis are discussed.
Interaction of marital status and genetic risk for symptoms of depression
Authors: Heath Andrew C , Eaves Lindon J , Martin Nicholas G
Published: March 2007

Depression scores (DSSI) were available for 1232 MZ and 751 DZ female twin pairs who completed a mailed questionnaire. Pairs were divided into those concordant for being in a marriage-like state, concordant for having no partners, and those discordant. The pattern of twin correlations differed according to marital status. Our results suggest that having a marriage-like relationship acts as a protective factor in reducing the impact of inherited liability to symptoms of depression in the general population.
Etiology of individual differences in birth weight of twins as a function of maternal smoking during pregnancy
Authors: van Baal Caroline GM , Boomsma Dorret I
Published: March 2007

Birth weight is in large extent influenced by gestational age. In addition genetic and environmental factors determine intrauterine growth and birth weight. The contributions of these factors may be influenced by maternal smoking during pregnancy. We examined birth weight and maternal smoking in a sample of 2930 twin pairs from the Netherlands Twin Register using structural equation modelling. Gestational age accounted for 27–44% of the variance in birth weight. A lower variability of birth weight and a lower association of birth weight with gestational age was found in twins whose mothers smoked during pregnancy. The variance not associated with gestational age was independent of maternal smoking during pregnancy. A systematic smaller part of the variability in birth weight was associated with variability in gestational age in second born twins compared to first born twins. The heritability of interindividual differences in birth weight was modest (10% for twins with non-smoking mothers and 11% for twins with smoking mothers). Common environmental influences other than gestational age accounted for a slightly larger part of the variance not associated with gestational age (17–20%).
Sex differences and non-additivity in the effects of genes on personality
Authors: Eaves Lindon J , Heath Andrew C , Neale Michael C , Hewitt John K , Martin Nicholas G
Published: March 2007

New large-sample data show that non-additive genetic effects, probably epistatic interactions between loci, and sex-limited gene expression are significant features of the genetic architecture of human personality as measured by questionnaire scales of extraversion and neuroticism. Three large data sets – new data on large samples (n = 20 554) of US twins, their spouses, parents, siblings and children, correlations for Australian twins (n = 7 532), and previously published twin data from Finland (n = 14 288) – are subjected to an integrated analysis to test alternative hypotheses about the genetic causes of family resemblance in personality. When allowance is made for differences in reliability of the scales, the combined data are consistent with the same model for variation. There are significant amounts of genetic non-additivity for both dimensions of personality. The evidence favours additive × additive epistatic interactions rather than dominance. In the case of neuroticism, there is especially strong evidence of sex differences in genetic architecture favouring a greater relative contribution of non-additive genetic effects in males. The data confirm previous claims to find no major contribution of the shared environment of twins and siblings to these dimensions of personality. Correlations between spouses are zero, and the correlations for very large samples of siblings and non-identical twins do not differ significantly.
Time trends in twin perinatal mortality in northern England, 1982–94
Authors: Glinianaia Svetlana V , Rankin Judith , Renwick Marjorie ,   on behalf of the Northern Region Perinatal Mortality Survey Steering Group
Published: March 2007

The dynamics of perinatal mortality rates (PNMR) and causes of death in twin pregnancies over 13 years in the Northern Region of the National Health Service in England is described. All twin perinatal deaths occurring between 1982–1994 were identified from the Northern Region Perinatal Mortality Survey. The twinning rate increased from 9.9 per 1000 maternities in 1982 to 12.0 in 1994. There was a total of 10734 twin pregnancies and of these 421 resulted in 530 perinatal deaths. The perinatal mortality rate in twins significantly decreased over time (1982–87, 55.4 per 1000; 1988–94, 44.4 per 1000; P = 0.01). The PNMR was significantly higher for twins from like-sexed than from unlike-sexed pairs (53.5 and 34.4 per 1000 respectively, P < 0.001). Despite no improvement in birthweight distribution in the twin population, birthweight-specific perinatal mortality rates for both like and unlike-sexed twins decreased for each birthweight category in 1988–94 compared with 1982–87. Twins with very low birthweight ( < 1500 g) comprised 69%, and preterm twins ( < 37 completed weeks of gestation) 74.9% of all twin perinatal deaths. The major immediate cause of early neonatal death was pulmonary immaturity (63%); antepartum anoxia caused 76.9% of antenatal deaths. Unexplained preterm labour and intrauterine death were the leading obstetric factors underlying death in twins. Despite a decrease over the 13 years, the perinatal mortality rate in twins in the Northern Region remains high. Continued monitoring of trends in twinning and mortality rates is needed to inform health care planning.
Maternal smoking and twinning
Authors: Källén Karin
Published: March 2007

In order to investigate a possible association between maternal smoking during pregnancy and twinning, information on 1 096 330 single births and 12 342 twin births in 1983–95 was obtained from the Swedish Medical Birth Registry (MBR). All odds ratios (OR) were estimated after stratification for year of birth and maternal age, parity, and educational level. Smoking women, compared with non-smoking women, were at increased risk of having dizygotic (DZ) twins, but the risk increase was only evident among multiparas. A strong association between previous involuntary childlessness and dizygotic (DZ) twinning (especially in primiparas) was found. The strongest association between maternal smoking and DZ twinning was found among multiparas without any history of involuntary childlessness (OR: 1.35, 95%CI:1.22–1.49), whereas among women who had experienced involuntary childlessness, the opposite was seen (OR: 0.82, 95%CI:0.66–1.00, no difference between parity strata). Weinberg's differential method was used to estimate the number of monozygotic (MZ) twins, and a method of estimating stratified ORs among mothers of MZ twins was presented. No association was found between MZ twinning and maternal smoking (OR: 0.96, 95%CI:0.86–1.07), and no confounding by parity or previous involuntary childlessness was indicated. Several non-causal explanations to the positive association between DZ twinning and maternal smoking among multiparas were discussed, but homogeneity over strata indicated that maternal smoking may be a true risk factor for double ovulation.
No paternal effect on monozygotic twinning in the Swedish Twin Registry
Authors: Lichtenstein Paul , Källén Bengt , Köster Max
Published: March 2007

Previous research has provided evidence for a genetic effect in monozygotic twinning, indicated by an increased risk for monozygotic women to have monozygotic offspring. However, since the biological mechanism for this trait is unknown, it is not clear if there exists a paternal inheritance. In this study we investigated twin pregnancies in offspring born in 1941–1996 to male twins in the Swedish Twin Registry and population controls born in 1926–1980. In total 4 225 331 offspring, of which 89 286 were twins, were studied. There was neither an increase in the probability for monozygotic men to have like-sexed twin offspring risk ratio (RR = 0.95; 95% CI = 0.77–1.13) nor an increase in the estimated number of monozygotic twin births. Thus, there is no evidence for a paternal effect on monozygotic twinning, suggesting that the gene(s) increasing the liability for division of the embryo are expressed in the mother and not in the fertilised egg.
Nature vs nurture: Are leaders born or made? A behavior genetic investigation of leadership style
Authors: Johnson Andrew M , Vernon Philip A , McCarthy Julie M , Molson Mindy , Harris Julie A , Jang Kerry L
Published: March 2007

With the recent resurgence in popularity of trait theories of leadership, it is timely to consider the genetic determination of the multiple factors comprising the leadership construct. Individual differences in personality traits have been found to be moderately to highly heritable, and so it follows that if there are reliable personality trait differences between leaders and non-leaders, then there may be a heritable component to these individual differences. Despite this connection between leadership and personality traits, however, there are no studies of the genetic basis of leadership using modern behavior genetic methodology. The present study proposes to address the lack of research in this area by examining the heritability of leadership style, as measured by self-report psychometric inventories. The Multifactor Leadership Questionnaire (MLQ), the Leadership Ability Evaluation, and the Adjective Checklist were completed by 247 adult twin pairs (183 monozygotic and 64 same-sex dizygotic). Results indicated that most of the leadership dimensions examined in this study are heritable, as are two higher level factors (resembling transactional and transformational leadership)derived from anobliquely rotated principal components factors analysis of the MLQ. Univariate analyses suggested that 48% of the variance in transactional leadership may be explained by additive heritability, and 59% of the variance in transformational leadership may be explained by non-additive (dominance) heritability. Multi-variate analyses indicatedthat most ofthe variables studiedshared substantial genetic covariance, suggesting a large overlap in the underlying genes responsible for the leadership dimensions.
Notes and Queries and the Pitt Rivers Museum
Authors: Petch Alison
Published: March 2007

This article examines the contribution that a major ethnographic museum, the Pitt Rivers Museum at the University of Oxford, has made to the development of anthropology in the United Kingdom, through the prism of a seminal publication, Notes and Queries on Anthropology, which was published in several editions between 1874 and 1951. While Notes and Queries has been of considerable interest to historians of anthropology, its connections to museum anthropology and to material culture studies have, to a large degree, gone unexamined hitherto.
Constructing Identities on Marbles and Terracotta: Representations of Classical Heritage in Greece and Turkey
Authors: Jezernik Božidar
Published: March 2007

During the late 18th century and after,Western Europeans construed ancient Greece as an exceptional land, peopled not with humans, but with super‐humans. As a result, modern Greeks were cast in the role of the living ancestors of European civilization. When they passed the antiquities laws and built museums for their preservation, they were imagined as true beneficiaries of their forefathers, even though not yet fully adequate for keeping their prestigious heritage. However, when the Ottomans endeavored to "modernize" their country and developed their interest in preserving antiquities, the "history‐conscious" West judged their efforts by much different standards.
Dancing Demons: Ceremonial Masks of Mongolia An online exhibition of the Asia Society
Authors: Charleux Isabelle
Published: March 2007

Isabelle Charleux teaches at the Sorbonne and is a researcher affiliated with the Centre National de la Recherche Scientifique (CNRS) in Paris.Her work focuses on Mongolian material culture, especially Buddhist architecture in Mongolia. She is the author of numerous works, including Temples et monastères de Mongolie‐Intérieure (Institut National d'Histoire de l'Art et Comité National des Travaux Historiques et Scientiques, 2006) and (with Edith Parlier) L'Art bouddhique (Scala, 2000).
Coptic Textiles. An online exhibition of the California Academy of Sciences
Authors: Hoskins Nancy Arthur
Published: March 2007

Nancy Arthur Hoskins is a former college weaving instructor and a specialist in the study of Coptic textiles. She is the author of various works, including The Coptic Tapestry Albums and the Archaeologist of Antinoé, Albert Gayet (University of Washington Press, 2004) and Weft‐Faced Pattern Weaves: Tabby to Taquete (University of Washington Press, 1992).
Great Lakes Native Quilting
Authors: Klassen Teri
Published: March 2007

Teri Klassen is a graduate student in the Department of Folklore and Ethnomusicology at Indiana University. Her studies focus on historical ethnography and material culture in the United States. The complex cultural history of American quiltmaking is her special interest. She recently published an article on quiltmaking and patriotism in the American Quilt Study Group's annual Uncoverings.
Book Reviews
Authors: Baumgarten Linda
Published: March 2007

American Artifacts of Personal Adornment, 1680‐1820 by Carolyn L. White. Lanham, MD: AltaMira Press, 2005. 160 pp.

Linda Baumgarten is Curator of Textiles and Costumes at the Colonial Williamsburg Foundation where she has worked since 1978. She is the author of What Clothes Reveal: The Language of Clothing in Colonial and Federal America (Yale University Press, 2002) and (with John Watson) Costume Close‐Up: Clothing Construction and Pattern, 1750–1790 (Quite Specific Media Group, 2000).
Book Reviews
Authors: Arnoldi Mary Jo
Published: March 2007

Unwrapping the Textile Traditions of Madagascar by Chapurukha M. Kusimba, J. Claire Odland, and Bennet Bronson, eds. Los Angeles: Fowler Museum of Cultural History, 2004. 196 pp. (Co‐published with the Field Museum.)

Mary Jo Arnoldi is a curator for African ethnology and arts in the Department of Anthropology, National Museum of Natural History. She is the author of Playing with Time: Art and Performance in Central Mali (Indiana University Press, 1995) and was the lead curator on the permanent exhibition African Voices that opened at the Smithsonian in 1999.
Declines in Low Birth Weight and Preterm Birth Among Infants Who Were Born to HIV-Infected Women During an Era of Increased Use of Maternal Antiretroviral Drugs: Pediatric Spectrum of HIV Disease, 1989–2004
Authors: Schulte Joann , Dominguez Ken , Sukalac Thomas , Bohannon Beverly , Fowler Mary Glenn ,   for the Pediatric Spectrum of HIV Disease Consortium
Published: March 2007

OBJECTIVE. Our goal was to determine trends in low birth weight and preterm birth among US infants born to HIV-infected women.

METHODS. We used data from the longitudinal Pediatric Spectrum of HIV Disease, a large HIV cohort, to assess trends in low birth weight and preterm birth from 1989 to 2004 among 11321 study infants. Among women with prenatal care, we also assessed risk factors, including maternal antiretroviral therapy during pregnancy, that were predictive of low birth weight and preterm birth using univariate and multivariate logistic regression models.

RESULTS. Overall, 11231 of 14464 infants who were enrolled in Pediatric Spectrum of HIV Disease were tested during the neonatal period. From 1989 to 2004, testing increased from 32% to 97%. The proportion of HIV-exposed infants who had low birth weight decreased from 35% to 21% and occurred in all racial/ethnic groups. Prevalence of preterm birth decreased from 35% to 22% and occurred in all groups. Any maternal antiretroviral therapy use increased from 2% to 84%. Among 8793 women who had prenatal care, low birth weight was associated with a history of illicit maternal drug use, unknown maternal HIV status before delivery, symptomatic maternal HIV disease, black race, Hispanic ethnicity, and infant HIV infection. Antiretroviral therapy or lack of it was not associated with low birth weight. Among women with prenatal care, preterm birth was associated with a history of illicit maternal drug use, symptomatic maternal HIV disease, no antiretroviral therapy, receipt of a 3-drug highly active antiretroviral therapy regimen with protease inhibitors, black race, and infant HIV infection.

CONCLUSIONS. The proportion of infants who had low birth weight or were born preterm declined during an era of increased maternal antiretroviral therapies. These Pediatric Spectrum of HIV Disease trends differ from the overall increases in both outcomes among the US population.
Efficacy of a Pill-Swallowing Training Intervention to Improve Antiretroviral Medication Adherence in Pediatric Patients With HIV/AIDS
Authors: Garvie Patricia A. , Lensing Shelly , Rai Shesh N.
Published: March 2007

OBJECTIVE. We aimed to retrospectively assess the efficacy of pill-swallowing training provided as a clinical intervention to referred pediatric patients with HIV in relation to improved adherence and subsequent related health outcomes. The primary goal of this study was to demonstrate participation in pill-swallowing training is associated with improved medication adherence as documented by routine pharmacy pill counts. Secondary objectives were to assess corresponding improvements in clinically observed biologic indicators of adherence, specifically, immunologic functioning (CD4+ T-cell%) and viral load, over time.

PATIENTS AND METHODS. A retrospective chart review of 23 pediatric patients with HIV aged 4 to 21 years who were clinically referred for pill-swallowing training by an experienced pediatric psychologist for either noted difficulties with currently prescribed antiretroviral regimens and/or desire to change the child's regimen/formulary. Patient demographics, reason(s) for pill-swallowing training referral, number of pill-swallowing training sessions required to attain success, adherence, CD4+ T-cell%, and viral load were abstracted at baseline and at ∼3 and 6 months posttraining.

RESULTS. Modal number of sessions required to acquire the pill-swallowing skill was 1 session. Younger children (aged 4–5 years) required a median of 2 training sessions, while older children required ≥3 sessions. A significant improvement in adherence from baseline to 6 months post–pill-swallowing training completion was observed, as were significant related improvements in CD4+ T-cell% and viral load.

CONCLUSIONS. Participation in pill-swallowing training related to improved medication adherence at 6 months posttraining. Subsequent improvements in related CD4+ T-cell% and viral load were noted over time, most significantly at 6 months postintervention. These preliminary findings provide justification for additional study via a prospective, randomized, controlled clinical trial. Pill-swallowing training potentially is a successful time-limited, cost-effective intervention to improve adherence to antiretroviral therapies, and thus medical status, in children with HIV.
Influence of tamper weight shape on dynamic compaction
Authors: Arslan H. , Baykal G. , Ertas O.
Published: March 2007

This paper presents the effect of tamper weight shape on the dynamic compaction method in granular soils. Although the dynamic compaction method appears to be very simple, it requires careful design of the compaction process. The aim of this study is to improve the efficiency and decrease the cost of deep compaction by using cylinder-shaped tamper weights. The influence of the shape of the bottom of the tamper weight on dynamic compaction efficiency was evaluated experimentally on sandy soils. Sands of three different densities were used to evaluate the compaction efficiency. Conical-bottom tamper weights were studied with the conic angle approximately the same values as the internal friction angles of the three different densities of soil. Also, in order to compare results, a flat-bottom tamper was used with the same weight. The results indicated significant increases of the amount of ground improvement by using a conical rather than a flat-bottom load.

Cet article traite de l'effet de la forme du poids de dameuse sur la méthode de compactage dynamique sur les sols granulaires. Bien que cette méthode apparaisse très simple, elle demande une conception soignée du processus de compactage. Cette étude a pour objectif d'améliorer l'efficacité et de réduire le coût du compactage profond en utilisant des poids de dameuse de forme cylindrique. Elle évalue expérimentalement l'influence de la forme de la base du poids de dameuse sur l'efficacité du compactage dynamique pour des sols sablonneux. Des sables de trois densités différentes ont été utilisés pour déterminer l'efficacité du compactage. L'étude porte sur des poids de dameuse de forme conique avec un angle conique correspondant approximativement aux mêmes valeurs que les angles de frottement interne des trois différentes densités de sable. Une dameuse de base plate, de même poids, a également été utilisée en vue d'établir une comparaison. Les résultats indiquent une augmentation significative de l'amélioration du sol lorsque l'on utilise une charge à base conique plutôt que plate.
Comparison of Means of Spatial Data in Unreplicated Field Trials
Authors: Plant Richard E.
Published: March 2007

The measurement technologies of site‐specific agriculture provide precision instruments at the landscape scale, permitting investigators and farmers to obtain data from experiments in commercial fields at previously unheard of spatial resolution. However, the statistical properties of data arising from these technologies are different from those of traditional small‐plot trials data. These differences provide the opportunity to analyze data in different ways. The objective of this paper is to develop a method for estimating the effective sample size and P value of a significance test of the difference between two means in an unreplicated large‐scale trial in a commercial field. The method is based on a modification of a well‐known correction for spatial autocorrelation of the data when testing the significance of the correlation coefficient between two random variables. An example, the comparison of readings taken from a yield monitor on two different days, is given to demonstrate the properties of the method.
Defoliation Effects on Production and Nutritive Value of Four Irrigated Cool‐Season Perennial Grasses
Authors: Volesky Jerry D. , Anderson Bruce E.
Published: March 2007

Irrigated cool‐season perennial grasses are becoming an important complementary forage source in the Central Plains. A study was conducted to evaluate effects of clipping stubble height on dry matter (DM) production, growth rate, tiller density, and nutrient content of smooth bromegrass (Bromus inermis Leyss.) orchardgrass (Dactylis glomerata L.), creeping foxtail (Alopecurus arundinaceus Poir.), and meadow bromegrass (Bromus riparius Rhem.) under irrigated conditions on a Cozad silt loam soil (fine‐silty, mixed, mesic Typic Haplustoll). Clipping treatments (35‐cm canopy height cut to 7‐, 14‐, and 21‐cm stubble heights) were applied to monoculture plots of these species for two growing seasons in a randomized complete block design. Stubble height effects on total DM production varied by species (P < 0.05). For orchardgrass and meadow bromegrass, DM production was similar at the 14‐ and 21‐cm stubble heights (22.22 Mg ha−1), but significantly greater than production at the 7‐cm stubble height (14.03 Mg ha−1). In contrast, DM production of smooth bromegrass and creeping foxtail was significantly greater at each successively higher stubble height. End‐of‐season tiller density of the 7‐cm stubble height treatment was about 50% of the tiller density of the 14‐cm and 21‐cm stubble height treatments. Stubble height effects on nutritive value varied by species and clipping period. Stubble height did not affect crude protein (CP) content of creeping foxtail, but CP was lower at the 7‐cm height for the other species. Defoliation strategies that maintain adequate residual herbage will optimize production of nutrient dense forage and maintain tiller density.