bluuebunny/crossref_metadata_2025 huggingface dataset:
Who benefits from learning with 3D models? the case of spatial ability
Authors: Huk T.
Published: November 2006

Empirical studies that focus on the impact of three‐dimensional (3D) visualizations on learning are to date rare and inconsistent. According to the ability‐as‐enhancer hypothesis, high spatial ability learners should benefit particularly as they have enough cognitive capacity left for mental model construction. In contrast, the ability‐as‐compensator hypothesis proposes that low spatial ability learners should gain particular benefit from explicit graphical representations as they have difficulty mentally constructing their own visualizations. This study examines the impact that interactive 3D models implemented within a hypermedia‐learning environment have on understanding of cell biology. Test scores in a subsequent knowledge acquisition test demonstrated a significant interaction term between students' spatial ability and presence/absence of 3D models. Only students with high spatial ability benefited from the presence of 3D models, while low spatial ability students got fewer points when learning this way. When using 3D models, high spatial ability students perceived their cognitive load to be low whereas the opposite was true for low spatial ability students. The data suggest that students with low spatial ability became cognitively overloaded by the presence of 3D models, while high spatial ability students benefited from them as their total cognitive load remained within working memory limits.
Design of a delegable SCORM conformant learning management system
Authors: Lu E.J.‐L. , Chen Y.‐H.
Published: November 2006

Owing to the emergence and flourishing of the Internet, traditional teaching and educational activities are increasingly relying on the convenient and global‐reaching networking technology. To boost up the development of e‐learning technology and the interoperability of learning materials, the Advanced Distributed Learning Initiative defined a data‐sharing standard, called the Sharable Content Object Reference Model (SCORM). In SCORM, because all learning materials (either SCOs or assets) are sharable, users cannot share (or delegate) parts or all of their teaching materials at will. This paper proposed an access control and delegation model for SCORM conformant learning management systems. Also, a prototype was developed to demonstrate the feasibility of the proposed model.
Learning to be a psychologist: the construction of identity in an online forum
Authors: Perrotta C.
Published: November 2006

The paper reports a study that investigated the construction of a common identity in an online Italian forum of psychologists based on asynchronous CMC. Discourse analysis was carried out on 20 discussions, and three Interpretative Repertoires were identified: (i) Professional Boundaries, (ii) disempowered psychology and (iii) psychology and health, which refer to three recurrent modalities of constructing the psychological profession. The study suggests that a framework drawing on social constructionism and Bourdieu's critical theory can help understand some aspects of identity in, and across, communities of practice. The main conclusion is that analysing critically how identities are constructed in learning environments, virtual or not, allows reconsidering the role of the cultural context in the production of those identities.
The role of rainfall and predators in determining synchrony in reproduction of savanna trees in Serengeti National Park, Tanzania
Authors: MDUMA SIMON A. R. , SINCLAIR A. R. E. , TURKINGTON ROY
Published: November 2006

We examined the factors determining synchrony in reproduction in nine Acacia and six other tree species in the Serengeti ecosystem.

We test two hypotheses: (i) an abiotic hypothesis where the primary determinant of synchrony is an adaptation to water availability; and (ii) biotic hypotheses where these adaptations to water can be further refined by additional adaptations to avoid predators, or attract seed and fruit dispersers.

Flowering and fruiting were recorded monthly for individually marked trees during 1997–2004. Flowering in different species occurs semi‐annually, annually or, in the case of one species, once every 2 years. For most species synchrony of flowering was correlated with seasonal rainfall, with lags related to the mean height of the species; small species flowered during the rains while larger species flowered in the dry season. Fruiting seasons occurred at the end of the rains irrespective of the flowering season.

Most species showed flowering synchrony greater than expected from the distribution of rainfall. This may be related to avoidance of insect seed predators through predator satiation. Two Acacias showed multi‐annual fruiting (masting), possibly as a predator avoidance mechanism. Acacia tortilis has two flowering seasons: a dry season flowering with early abortion of pods and a wet season flowering producing successful fruits.

Two species of Commiphora appeared to be synchronized so as to attract birds that disperse seeds. Acacia tortilis produced indehiscent pods attractive to ungulates, possibly to kill bruchid beetles during digestion and so increase seed viability.

Our results suggest that synchrony in these trees is caused by a strong interaction between abiotic and biotic factors. Closely related species have different reproductive patterns of synchrony that seem to be adapted to different combinations of rainfall, predators and dispersers. Rainfall is the primary determinant but the activities of predators and dispersers increase the degree of synchrony.
Socio‐economic position, household composition, health status and indicators of the well‐being of mothers of children with and without intellectual disabilities
Authors: Emerson E. , Hatton C. , Llewellyn G. , Blacker J. , Graham H.
Published: November 2006

Background  Many previous studies have reported that mothers of children with intellectual disabilities (IDs) are more likely to show signs of psychological distress and have lower well‐being than mothers of ‘typically developing’ children. Our aim was to estimate the extent to which these differences may be accounted for by between‐group differences in socio‐economic position.

Methods  This study involved secondary analysis of happiness, self‐esteem and self‐efficacy variables in a nationally representative sample of 6954 British mothers with dependent children under the age of 17 years, 514 of whom were supporting a child with an ID.

Results  Mothers of children with IDs reported lower levels of happiness, self‐esteem and self‐efficacy than mothers of children without IDs. Statistically controlling for differences in socio‐economic position, household composition and maternal characteristics fully accounted for the between‐group differences in maternal happiness, and accounted for over 50% of the elevated risk for poorer self‐esteem and self‐efficacy.

Conclusions  A socially and statistically significant proportion of the increased risk of poorer well‐being among mothers of children with IDs may be attributed to their increased risk of socio‐economic disadvantage.
A sequence stratigraphic model for an intensely bioturbated shallow‐marine sandstone: the Bridport Sand Formation, Wessex Basin, UK
Authors: MORRIS JENNY E. , HAMPSON GARY J. , JOHNSON HOWARD D.
Published: November 2006

The Bridport Sand Formation is an intensely bioturbated sandstone that represents part of a mixed siliciclastic‐carbonate shallow‐marine depositional system. At outcrop and in subsurface cores, conventional facies analysis was combined with ichnofabric analysis to identify facies successions bounded by a hierarchy of key stratigraphic surfaces. The geometry of these surfaces and the lateral relationships between the facies successions that they bound have been constrained locally using 3D seismic data. Facies analysis suggests that the Bridport Sand Formation represents progradation of a low‐energy, siliciclastic shoreface dominated by storm‐event beds reworked by bioturbation. The shoreface sandstones form the upper part of a thick (up to 200 m), steep (2–3°), mud‐dominated slope that extends into the underlying Down Cliff Clay. Clinoform surfaces representing the shoreface‐slope system are grouped into progradational sets. Each set contains clinoform surfaces arranged in a downstepping, offlapping manner that indicates forced‐regressive progradation, which was punctuated by flooding surfaces that are expressed in core and well‐log data. In proximal locations, progradational shoreface sandstones (corresponding to a clinoform set) are truncated by conglomerate lags containing clasts of bored, reworked shoreface sandstones, which are interpreted as marking sequence boundaries. In medial locations, progradational clinoform sets are overlain across an erosion surface by thin (<5 m) bioclastic limestones that record siliciclastic‐sediment starvation during transgression. Near the basin margins, these limestones are locally thick (>10 m) and overlie conglomerate lags at sequence boundaries. Sequence boundaries are thus interpreted as being amalgamated with overlying transgressive surfaces, to form composite erosion surfaces. In distal locations, oolitic ironstones that formed under conditions of extended physical reworking overlie composite sequence boundaries and transgressive surfaces. Over most of the Wessex Basin, clinoform sets (corresponding to high‐frequency sequences) are laterally offset, thus defining a low‐frequency sequence architecture characterized by high net siliciclastic sediment input and low net accommodation. Aggradational stacking of high‐frequency sequences occurs in fault‐bounded depocentres which had higher rates of localized tectonic subsidence.
Development of spatially diverse and complex dune‐field patterns: Gran Desierto Dune Field, Sonora, Mexico
Authors: BEVERIDGE CARRIE , KOCUREK GARY , EWING RYAN C. , LANCASTER NICHOLAS , MORTHEKAI P. , SINGHVI ASHOK K. , MAHAN SHANNON A.
Published: November 2006

The pattern of dunes within the Gran Desierto of Sonora, Mexico, is both spatially diverse and complex. Identification of the pattern components from remote‐sensing images, combined with statistical analysis of their measured parameters demonstrate that the composite pattern consists of separate populations of simple dune patterns. Age‐bracketing by optically stimulated luminescence (OSL) indicates that the simple patterns represent relatively short‐lived aeolian constructional events since ∼25 ka. The simple dune patterns consist of: (i) late Pleistocene relict linear dunes; (ii) degraded crescentic dunes formed at ∼12 ka; (iii) early Holocene western crescentic dunes; (iv) eastern crescentic dunes emplaced at ∼7 ka; and (v) star dunes formed during the last 3 ka. Recognition of the simple patterns and their ages allows for the geomorphic backstripping of the composite pattern. Palaeowind reconstructions, based upon the rule of gross bedform‐normal transport, are largely in agreement with regional proxy data. The sediment state over time for the Gran Desierto is one in which the sediment supply for aeolian constructional events is derived from previously stored sediment (Ancestral Colorado River sediment), and contemporaneous influx from the lower Colorado River valley and coastal influx from the Bahia del Adair inlet. Aeolian constructional events are triggered by climatic shifts to greater aridity, changes in the wind regime, and the development of a sediment supply. The rate of geomorphic change within the Gran Desierto is significantly greater than the rate of subsidence and burial of the accumulation surface upon which it rests.
Cathodoluminescence characterization of quartz particles in mature arenites
Authors: GÖTTE THOMAS , RICHTER DETLEV K.
Published: November 2006

A combination of cathodoluminescence (CL) microscopy with digital image analysis and spectroscopic analysis allows the detailed investigation of the commonly occurring colour shift from initial to final CL‐colours in detrital quartz with increasing irradiation. A method for the quantification of the colour shift is presented and applied to different quartz sands: unlithified sands of the Lower Cretaceous Kuhfeld Formation from Ottenstein (W Germany) and Holocene sands from the barrier island of Wangerooge (N Germany). The colour shift depends on the defect structure of the quartz grains. The defect structure is determined by the physico‐chemical conditions during crystallization and therefore can help trace the source of quartz grains. A total of 25 different types of quartz grains in the Ottenstein‐sands indicates a highly variable southern provenance. Many of the grains have recycled quartz cement overgrowths indicating an at least second cycle origin. In contrast, only 16 different quartz types have been observed in the Wangerooge‐sands reflecting a less varied plutonic to metamorphic Scandinavian provenance. The study demonstrates the potential of quantified CL initial colour and colour shift in assessing the provenance of quartz‐rich sands and sandstones.
Short‐term morphological change and sediment dynamics in the intertidal zone of a macrotidal beach
Authors: MASSELINK GERHARD , AUGER NIGEL , RUSSELL PAUL , O'HARE TIM
Published: November 2006

This paper describes the morphological and sedimentological evolution of a macrotidal beach over a 20 day period under varying hydrodynamic conditions (significant breaker heights of 0·3–2 m and tidal ranges of 2–5 m). During the field campaign, an intertidal bar developed around the mid‐tide level, migrated onshore, welded to the upper beach and was then flattened under energetic wave conditions. The bar had a wave breakpoint origin and its formation was triggered by a reduction in tidal range, causing more stationary water‐level conditions, rather than an increase in wave height. Most of the onshore bar migration took place while the bar was positioned in the inner to mid‐surf zone position, such that the bar moved away from the breakpoint and exhibited ‘divergent’ behaviour. The depth of disturbance over individual tidal cycles was 10–20% of the breaker height. Such values are more typical of steep reflective beaches, than gently sloping, dissipative beaches, and are considered to reflect the maximum height of wave‐generated ripples. The grain size distribution of surficial sediments did not vary consistently across the beach profile and temporal changes in the sedimentology were mostly unrelated to the morphological response. The lack of clear links between beach morphology and sedimentology may be in part due to shortcomings in the sampling methodology, which ignored the vertical variability in the sediment size characteristics across the active layer.
Living‐donor kidney transplantation: risks of the donor – benefits of the recipient
Authors: Weitz Jürgen , Koch Moritz , Mehrabi Arianeb , Schemmer Peter , Zeier Martin , Beimler Jörg , Büchler Markus , Schmidt Jan
Published: November 2006

Abstract:  For patients with end‐stage renal disease, kidney transplantation is the optimal therapy. Due to organ shortage, however, most patients have to wait on dialysis for a considerable period of time prior to transplantation. Living‐donor kidney transplantation is a valid option to expand the organ pool and to reduce waiting time. The risk–benefit ratio of living‐donor kidney transplantation needs to be evaluated critically, as healthy persons voluntarily donate an organ for transplantation. The available data from the literature seem to prove that the donor operation can be performed with a minimal perioperative risk. Regarding the long‐term course after kidney donation, the published data suggest that the risk is minimal for well‐selected healthy donors who are closely followed postoperatively. The potential donor, however, needs to be completely informed regarding the potential short‐ and long‐term risks of kidney donation prior to the planned procedure. From the recipient point of view, transplantation of a kidney from a living donor is a very good if not the optimal option, as the short‐ and long‐term outcomes seem to be favorable compared with cadaveric kidney transplantation. With donor safety being constantly monitored, it seems to be justified to further pursue living‐donor kidney transplantation programs.
Antifibrotic actions of mycophenolic acid
Authors: Morath Christian , Schwenger Vedat , Beimler Jörg , Mehrabi Arianeb , Schmidt Jan , Zeier Martin , Muranyi Walter
Published: November 2006

Abstract:  Mycophenolic acid (MPA) is a highly selective, non‐competitive and reversible inhibitor of the inosine monophosphate dehydrogenase (IMPDH), the rate‐limiting enzyme in the de novo biosynthesis of guanosine nucleotides. Mycophenolate mofetil (MMF, the ester prodrug of MPA) strongly inhibits both T‐ and B‐lymphocyte proliferation and has now been widely used in the prevention of acute and chronic allograft rejection. Recent evidence, however, suggests that MMF is also capable of inhibiting the proliferation of non‐immune cells. In various cell lines, e.g. smooth muscle cells, renal tubular cells, mesangial cells, and fibroblasts, MPA reduced or even abrogated proliferation in response to proliferative stimuli. In animal studies, MMF ameliorated renal lesions in immune‐mediated disease, e.g. in the Anti‐Thy 1.1 model and experimental lupus nephritis, but was also effective in non‐immune‐mediated renal damage, e.g. in the rat remnant kidney model or in a model of chronic cyclosporine nephrotoxicity in the rat. In humans, MMF reduced proteinuria in steroid‐resistant nephrotic syndrome and had beneficial effects in the prevention and treatment of chronic allograft nephropathy and calcineurin inhibitor toxicity through the reduction of immune‐ and non‐immune‐mediated renal damage. MMF is well tolerated and has proven to be a relatively safe drug. Taken together, there is a growing body of evidence pointing to therapeutic applications of MMF other than immunosuppression, in particular the prevention of fibrosis.
Interventional therapy of vascular complications following renal transplantation
Authors: Libicher Martin , Radeleff Boris , Grenacher Lars , Hallscheidt Peter , Mehrabi Arianeb , Richer Götz M , Kauffmann Günther , Hosch Waldemar
Published: November 2006

Abstract:  Renal transplantation is accepted as the preferred treatment for most cases of end‐stage renal disease. Postoperative vascular complications include stenosis or thrombosis of the transplant renal artery or arteriovenous fistulas after biopsy. Impaired arterial perfusion of the transplant may be the leading cause for graft dysfunction or refractory hypertension. Therefore, non‐invasive imaging modalities are required to detect and locate vascular complications with high accuracy. Doppler ultrasound is suited as a screening method for the detection of impaired graft perfusion. Magnetic resonance imaging (MRI) is used for an accurate diagnosis of vascular complications and to support decision for appropriate surgical or interventional treatment. Minimal invasive techniques like percutaneous transluminal angioplasty and stent placement have evolved as safe procedures with a high technical success rate reducing substantial morbidity. They can be considered as an alternative to surgical treatment of transplant renal artery stenosis (TRAS). Embolization of severe arteriovenous fistulas is the method of choice if the feeding artery can be occluded through a microcatheter. In selected cases, even catheter‐guided fibrinolytic treatment of arterial thrombosis might be considered, if instantaneous surgery is considered a high‐risk procedure. This article reviews the imaging features of common vascular complications after renal transplantation with focus on MRI. In addition, interventional radiological techniques are described for the treatment of TRAS, acute thrombotic occlusion, and arteriovenous fistulas.
Mycophenolate mofetil in liver transplantation – is monotherapy safe?
Authors: Schmeding Maximilian , Neumann Ulf P. , Neuhaus Ruth , Neuhaus Peter
Published: November 2006

Abstract: Liver transplantation (LTX) today has become a routine procedure granting curative treatment for various hepatic diseases with excellent survival rates. Constant improvement of immuno‐suppressive regimens has led to significant reduction of rejection frequency and increased safety in long‐term management. Calcineurin‐inhibitors play the key role in most immunosuppressive protocols providing strong T‐cell suppression yet often associated with numerous side‐effects. Increasing renal insufficiency as well as hypertension, hyperglycaemia, hyperuricaemia, and increased risk of secondary malignancy account for the major problems in short‐ and long‐term follow‐up of LTX patients. Mycophenolate mofetil (MMF) as a purine‐synthesis inhibitor has proved to be a potent immunosuppressive agent largely free of the CI‐associated side‐effects. MMF therefore has been used to modulate immunosuppressive protocols in order to both increase efficacy and to reduce CI‐related side‐effects such as nephrotoxicity. In recent years, MMF‐monotherapy protocols have been suggested for LTX patients with renal insufficiency. This review provides an overview on the current role of MMF in immunosuppressive protocols after LTX and evaluates innovative therapeutic concepts.
Biliary complications after liver transplantation
Authors: Hampe T. , Dogan A. , Encke J. , Mehrabi A. , Schemmer P. , Schmidt J. , Stiehl A , Sauer P.
Published: November 2006

Abstract:  Biliary complications remain a substantial cause of morbidity following liver transplantation. They have been reported to occur in a rate of 10–15% of full‐size transplantations and may be higher in living donor, split or reduced size liver transplantations. The most common biliary complications following liver transplantations are leaks and strictures. In both, the incidence varies with respect to type of graft and donor as well as the type of biliary anastomosis. The management of the biliary complications requires a multidisciplinary approach and has changed over the past decade, favoring endoscopic and radiological techniques. Surgical revision including retransplantation is reserved for patients in whom endoscopic and interventional modalities are unsuccessful.
Production and characterization of murine monoclonal antibodies against human podocalyxin
Authors: Rodríguez R. B. , Butta N. , Larrucea S. , Alonso S. , Parrilla R.
Published: November 2006

Podocalyxin (podxl) is a protein with a peptide bone of ∼55.5 kDa that undergoes a post‐translational glycosylation, yielding a final molecular mass from ∼145 to ∼200 kDa. This protein is normally found covering the vascular side of the epithelial glomerular cells, the podocytes, and its presence is essential to maintain a normal renal function. It has also been reported in other cells and tissues although its function has not been yet clarified. The carboxy‐terminal intracellular domain of podxl is nearly 100% identical in most species; however, the ectodomain shows considerable variations although the cysteine residues are conserved. Detection of this protein is elusive, most likely due to differences in post‐translational modifications. We aimed at producing murine monoclonal antibodies against human podxl. Immunization with Chinese hamster ovarian ‐hpodxl‐green fluorescence protein live cells yielded five different monoclonal antibodies that were characterized by enzyme‐linked immunosorbent assay, sodium dodecyl sulfate–polyacrylamide gel electrophoresis/western blot, flow cytometry, immunohistochemistry, and immunoprecipitation. The different behavior of these antibodies suggests that some of them may react against epitopes masked by different glycosylated protein moieties.
Reactive oxygen species generation and antioxidant systems in plant mitochondria
Authors: Navrot Nicolas , Rouhier Nicolas , Gelhaye Eric , Jacquot Jean‐Pierre
Published: November 2006

In living cells, reactive oxygen species (ROS) play a key role in signaling but these compounds can also damage macromolecules. As in other compartments, the mitochondrial ROS concentrations need to be tightly controlled. Plant mitochondria contain several antioxidant systems that are not only able to scavenge ROS and limit their production but also to repair damages to macromolecules and possibly to serve as redox sensors. They comprise ascorbate‐ and glutathione‐dependent pathways as well as systems based on thioredoxin (TRX)‐ and glutaredoxin (GRX)‐like molecules. This review describes the various mitochondrial redox pathways for ROS control in plants with special emphasis on the poorly studied GRX and TRX systems and provides perspectives for future research in this area.
Digestibility and nitrogen retention of diets containing different levels of fibre in local (Mong Cai), F1 (Mong Cai × Yorkshire) and exotic (Landrace × Yorkshire) growing pigs in Vietnam
Authors: Len N. T. , Lindberg J. E. , Ogle B.
Published: November 2006

Total tract digestibility and nitrogen retention of three diets containing different levels of fibre [200, 260 and 320 g/kg neutral detergent fibre (NDF) in dry matter] were determined in three breeds of growing pig at an initial age of approximately 3.5 months. The breeds were local (Mong Cai, MC), F1 crossbred (MC × Yorkshire) and exotic (Landrace × Yorkshire, LY), allocated at random within breed (block) to double 3 × 3 Latin squares. The main fibrous ingredients of the experimental diets were rice bran, cassava residue meal and non‐dehulled groundnut cake meal. Digestibility of organic matter (OM), crude protein (CP), NDF, crude fibre, gross energy (GE) and ether extract (EE) decreased as the level of dietary NDF increased (p < 0.001). The r2 values for the relationship between NDF level and digestibility of OM, CP, GE and EE were 83%, 83%, 80% and 82% respectively. On average, an increase in NDF content of 1% unit resulted in a decrease in OM, CP, GE and EE digestibility of 0.67%, 0.75%, 0.50% and 0.42% units respectively. Digestibility of energy and nutrients was the highest for MC and the lowest for LY (p < 0.01), with intermediate values for F1. There was a negative effect of NDF level on nitrogen (N) retained as a proportion of intake (p < 0.05). Nitrogen retention and utilization were significantly higher (p < 0.001) for LY than for MC and F1 pigs.
Influence of different phosphorus levels and phytase supplementation in gestation diets on sow performance
Authors: Lyberg K. , Andersson H. K. , Simonsson A. , Lindberg J. E.
Published: November 2006

A total of 104 sows of different parities were studied. They were fed four diets with different phosphorus (P) levels during gestation for two reproductive cycles, while the same diet was fed during lactation. The aim was to decrease the total P level in the diet during gestation and to evaluate the effect on sow performance. The gestation treatments were low P (LP−; 3.7 g P/kg feed), low P with phytase (LP+, Ronozyme® P; 765 FTU/kg feed), medium P (MP; 4.5 g P/kg feed) and high P (HP; 6.0 g P/kg feed). Daily feed allowances were 2.6 kg during gestation and 9.2 kg during lactation. Number of born piglets and piglet mortality were higher (p < 0.05) in the LP treatments than in the MP and HP treatments. No difference (p > 0.05) in the numbers of live‐born piglets, piglet birthweights, sow weights or piglet weight gains was found between the treatments. Phosphorus level in sow milk was the highest (p < 0.05) in the MP treatment, while no effects (p > 0.05) of treatment were found on milk Ca levels, P and Ca levels in serum of sows and piglets, nor on the analysed mineral, fat and protein contents of piglets. The estimated average requirement of P for the entire gestation period was 4.4–4.5 g/day. In conclusion, a reduction of dietary total P content during gestation did not result in negative effects on sow or piglet performance. This suggests that it should be possible to lower the dietary P content for gestating sows, compared with earlier recommendations, and thereby reduce the environmental P pollution.
Synchronous intercontinental splits between assemblages of woodpeckers suggested by molecular data
Authors: Fuchs Jérôme , Ohlson Jan I. , Ericson Per G. P. , Pasquet Eric
Published: November 2006

The woodpeckers (Piciformes: Picinae) comprise a widely distributed and species‐rich clade of birds that is strongly associated with trees for feeding, nesting, or both. Because of this association, woodpeckers provide a useful model for evaluating the impact of climatic and tectonic events on the diversification of forest birds during the Tertiary. In order to resolve the biogeographical history of the woodpeckers, we have analysed sequences from two nuclear introns and one mitochondrial gene using likelihood and Bayesian approaches. Our analyses favour a tropical Eurasian origin; divergences between African, Indo‐Malayan and New World clades with subsequent colonizations of Africa and the New World occurred synchronously during the Middle Miocene, a period corresponding to the expansion of the C4 grasses and the uplift of the Himalayan‐Tibetan plateau. The taxonomic diversification of woodpeckers at this time may be attributed to the fragmentation of forests in response to the drier climate, which in turn prevented gene flow between tropical stocks in Africa, Indo‐Malaya and the New World. Our estimates of colonization times of South America predate the closure of the Panama Isthmus and support the hypothesis of a short‐lived, terrestrial corridor at the end of the Miocene, 5.7 Myr BP.
Bladder tumour development after urothelial carcinoma of the upper urinary tract is related to primary tumour location
Authors: Zigeuner Richard E. , Hutterer Georg , Chromecki Thomas , Rehak Peter , Langner Cord
Published: November 2006

OBJECTIVE

To better define the predictors of bladder tumour development in patients operated for upper urinary tract urothelial cancer (UT‐UC).

PATIENTS AND METHODS

Surgical specimens from 191 consecutive patients with no history of bladder cancer and operated for UT‐UC were chosen for analysis. Bladder tumour development was assessed in relation to UT‐UC location, tumour multiplicity, stage and grade, margin status, mode of operation, age and gender.

RESULTS

Overall, 51 of 191 (27%) patients developed subsequent bladder tumours, including 25 of 123 (20%) with pelvic, 19 of 47 (40%) with ureteric and seven of 21 (33%) with multifocal tumours (P = 0.04 for all subgroups; P = 0.01 for pelvic vs ureteric). There was no influence of the other variables. The median (mean, range) time to recurrence was 12 (18, 3–64) months. In a multivariate analysis, ureteric tumour location was an independent predictor (P = 0.02; risk ratio, RR, 2.0, 95% confidence interval, CI, 1.1–3.7). After excluding 68 patients with systemic disease progression, bladder tumour development was noted in 39 of 123 (32%), including 18 of 76 (24%) with pelvic, 16 of 34 (47%) with ureteric and five of 13 with multifocal tumours (P = 0.06 for all subgroups; P = 0.02 for pelvic vs ureteric). In a multivariate analysis, ureteric location (P = 0.03; RR 2.1, 95% CI 1.1–4.2) and high tumour grade (P = 0.04; RR 2.2, 95% CI  1.03–4.7) were independent predictors of subsequent bladder tumour development.

CONCLUSION

The risk of developing a bladder tumour after surgery for UT‐UC is significantly related to ureteric tumour location and high tumour grade. Clinical trials to evaluate a possible reduction of bladder cancer risk by intraoperative ureteric ligation and/or peri‐operative topical intravesical chemotherapy instillation are justified.
Nephroureterectomy for treating upper urinary tract transitional cell carcinoma: time to change the treatment paradigm?
Authors: Brown Gordon A. , Busby J. Erik , Wood Christopher G. , Pisters Louis L. , Dinney Colin P.N. , Swanson David A. , Grossman H. Barton , Pettaway Curtis A. , Munsell Mark F. , Kamat Ashish M. , Matin Surena F.
Published: November 2006

OBJECTIVE

To evaluate factors associated with disease recurrence and survival in patients undergoing nephroureterectomy for upper urinary tract transitional cell carcinoma (UUT‐TCC) in one centre over an 18‐year period.

PATIENTS AND METHODS

The records of patients who had a nephroureterectomy for UUT‐TCC at our institution from 1986 to 2004 were reviewed for clinical, pathological and treatment period data. Cox’s proportional hazards regression model was used to test the statistical significance of several potential prognostic factors for recurrence and survival.

RESULTS

The median overall duration of follow‐up was 2.5 years for 184 patients. Significant prognosticators for disease‐specific survival (DSS) by univariate analysis were tumour stage (P < 0.01), tumour grade (P < 0.01), node‐positive disease (P < 0.01), multifocality (P = 0.03), previous cystectomy (P < 0.01) and synchronous bilateral UUT‐TCC (P = 0.02). On multivariate analysis, only tumour stage (P = 0.03) and grade (P = 0.01) correlated with DSS. The median recurrence‐free survival duration was 2.4 years. In 44 patients, the disease recurred outside the bladder; 15 (8.2%) had local recurrence, 20 (10.9%) distant metastasis, and nine (4.9%) both local and distant recurrence. Bladder tumours occurred in 40 (26.1%) patients with no previous cystectomy. The evaluation of treatment outcome during three periods of the study showed no significant effect on DSS.

CONCLUSION

Tumour stage and grade correlated with DSS in this cohort, with no improvement in outcome over the 18‐year period assessed. Patients with high‐stage and high‐grade disease continue to fare poorly, suggesting a need for changing the treatment protocol. Judiciously applying a multimodal approach to the management of high‐risk patients by incorporating neoadjuvant chemotherapy and surgical resection might provide, for the first time, the opportunity to improve patient outcome.
The association between local atherosclerosis and prostate cancer
Authors: Hager Martina , Mikuz Gregor , Bartsch Georg , Kolbitsch Christian , Moser Patrizia L.
Published: November 2006

OBJECTIVE

To morphometrically compare local atherosclerotic changes in cancerous prostate with those in noncancerous prostate specimens, as epidemiological studies report a positive association between the prevalence of general atherosclerosis and prostate cancer.

MATERIALS AND METHODS

The intima‐to‐media‐ratio (IMR) of 538 prostate capsular tissue arteries was measured in 50 prostate cancer‐positive and 29 prostate cancer‐negative specimens (including 26 with benign prostatic hyperplasia and three with normal prostatic tissue).

RESULTS

An IMR of >1 was significantly associated with prostate cancer and a greater risk of prostate cancer (odds ratio 2.28). The IMR was >1 in cancer‐positive specimens about twice as often as in cancer‐negative tissue.

CONCLUSION

Local atherosclerosis (measured by the IMR) was more pronounced in prostate cancer‐positive than in prostate cancer‐negative specimens. The results support the view that men with local atherosclerotic lesions are at higher risk of prostate cancer.
A matched‐cohort comparison of laparoscopic cryoablation and laparoscopic partial nephrectomy for treating renal masses
Authors: O’Malley Rebecca L. , Berger Aaron D. , Kanofsky Jamie A. , Phillips Courtney K. , Stifelman Michael , Taneja Samir S.
Published: November 2006

OBJECTIVE

To compare the surgical outcomes of elderly patients with renal masses treated with laparoscopic partial nephrectomy (LPN) or laparoscopic cryoablation (LCA).

PATIENTS AND METHODS

All 15 patients who had LCA at the authors’ institution between May 2003 and July 2005 were included, and compared with a matched cohort of 15 patients selected by patient age and tumour size, from a pre‐existing database of 104 patients who had LPN from July 2002 to July 2005. The two groups were compared for gender, number of comorbidities, American Society of Anesthesiologists status (ASA), body mass index (BMI), baseline renal function and haematocrit, location and size of lesion, length of stay, operative time, estimated blood loss (EBL), transfusion rate, number and type of complications, conversion rate, and postoperative renal function and haematocrit.

RESULTS

The two groups were similar in age, sex, BMI, ASA, baseline renal function, haematocrit, size and side of tumour, the percentage of exophytic tumours, and the likelihood of more than one comorbidity. Surgical outcomes between the groups were also relatively similar. The length of stay, creatinine and haematocrit levels after surgery did not differ between the groups. The LPN group had a significantly longer operation (248 vs 152 min, P < 0.001) and higher EBL (222 vs 59 mL, P = 0.007) than the LCA group, but only one patient required a transfusion and there was no discernible difference in discharge haematocrit values. No recurrences were detected in either group, with a similar mean follow‐up of 9.8 and 11.9 months, respectively.

CONCLUSION

Although this matched‐cohort comparison showed that LPN had a higher mean EBL, a longer operation and higher relative risk of open conversion, the overall clinical outcome was similar in terms of complication rates, length of stay and changes in creatinine and haematocrit after surgery. In this small retrospective evaluation, there was similar morbidity, treatment outcome and short‐term efficacy with LCA and LPN. At present, although still experimental, LCA is a good choice for elderly patients with comorbidities precluding blood loss or renal ischaemia. However, in experienced hands, LPN is a preferred option for most elderly patients and should be considered when contemplating definitive treatment of renal masses.
The Relationships Among Body Image, Body Mass Index, Exercise, and Sexual Functioning in Heterosexual Women
Authors: Weaver Angela D. , Byers E. Sandra
Published: November 2006

Problems related to negative body image are very common among young women. In this study, we examined the relationship between women's body image and their sexual functioning over and above the effects of physical exercise and body mass index (BMI) in a sample of 214 university women. Low situational body image dysphoria and low body dissatisfaction were associated with high sexual assertiveness and sexual esteem, low sexual anxiety, and fewer sexual problems. Positive body image was significantly associated with better sexual functioning, even after controlling for BMI and exercise. Although related to body image, BMI and exercise did not predict sexual functioning. These results were interpreted as indicating that a woman's subjective body image is significantly related to her sexual functioning beyond the effects of actual body size and level of physical exercise.
Acculturation and Eating Disorders in a Mexican American Community Sample
Authors: Cachelin Fary M. , Phinney Jean S. , Schug Robert A. , Striegel-Moore Ruth H.
Published: November 2006

Our purpose was to investigate acculturation and eating disorders by examining the role of ethnic identity and by utilizing a bidimensional perspective toward two cultures. We predicted that orientation toward European American culture and lower ethnic identity would be positively associated with eating disorders. Participants were 188 Mexican American women recruited from the community (79 with eating disorders and 109 control women). The Structured Clinical Interview for DSM-IV-TR and Eating Disorder Examination were used to establish diagnoses. The Acculturation Rating Scale for Mexican Americans–II and the Multigroup Ethnic Identity Measure assessed Anglo orientation, Mexican orientation, and ethnic identity. Orientation toward Anglo American culture was significantly associated with eating disorders, whereas orientation toward Mexican culture and strength of ethnic identity were not associated with eating disorder status. Findings point to the role of Anglo cultural orientation in the development of eating disorders and underscore the need for future research to utilize bidimensional models.
Understanding Female Sport Attrition in a Stereotypical Male Sport Within the Framework of Eccles's Expectancy–Value Model
Authors: Guillet Emma , Sarrazin Philippe , Fontayne Paul , Brustad Robert J.
Published: November 2006

An empirical research study based upon the expectancy–value model of Eccles and colleagues (1983) investigated the effect of gender-role orientations on psychological dimensions of female athletes' sport participation and the likelihood of their continued participation in a stereotypical masculine activity. The model (Eccles et al., 1983) posits that gender-role orientation is linked to the intention to persist or discontinue sport participation, which is acted upon indirectly through mediation by two motivational variables: an individual's perceived competence and the perceived value of the activity. Three models were compared to test this mediation hypothesis with 333 female adolescent handball players in a prospective study. Results from structural equation modeling showed that a fully mediated model fit the data. The masculinity orientation positively predicted value for and perceived competence in handball, whereas the femininity orientation negatively predicted perceived competence. In addition, the two motivational variables negatively predicted intention to drop out. Finally, such intentions are the more proximal predictors of actual dropout.
Rolling with the Changes: A Role Congruity Perspective on Gender Norms
Authors: Diekman Amanda B. , Goodfriend Wind
Published: November 2006

Role congruity theory (e.g., Eagly & Diekman, 2005 ) posits that a group will be positively evaluated when its characteristics are perceived to align with the requirements of the group's typical social roles. Social roles may thus form the basis of norms that prescribe valued behavior for men and women. Three experiments explored the relationship between perceived social roles and the prescriptive content of gender stereotypes by examining perceptions of cross-temporal role change. In the first study, participants evaluated the gender-stereotypic traits of past, present, and future men and women. In the second study, participants evaluated descriptions of consensually perceived trends for men and women. In the third study, participants read experimentally manipulated descriptions of role changes in a novel society and evaluated the traits of future citizens. Perceptions of cross-temporal changes in social roles (whether naturally occurring or experimentally manipulated) were associated with differential valuing of role-congruent characteristics. In general, participants' responses reflected a pattern of anticipated accommodation to shifts in social roles, with greater value projected for characteristics that facilitate role success.
Nonverbal Behavior, Status, and Gender: How do We Understand Their Relations?
Authors: Hall Judith A.
Published: November 2006

The causes of gender differences in nonverbal behavior are not well understood. The present article discusses status as a possible explanation and analyzes some of the methodological and conceptual challenges associated with testing that hypothesis. The study by Helweg-Larsen, Cunningham, Carrico, and Pergram (2004 ), which investigated gender in relation to nodding toward peers versus professors in college classes, is highlighted to demonstrate some of the difficulties facing researchers when testing the status explanation.
Stereotype Threat and the Gender Gap in Political Knowledge
Authors: McGlone Matthew S. , Aronson Joshua , Kobrynowicz Diane
Published: November 2006

Men tend to achieve higher response accuracy than women on surveys of political knowledge. We investigated the possibility that this performance gap is moderated by factors that render the communicative context of a survey intellectually threatening to women and thereby induce stereotype threat. In a telephone survey of college students' political knowledge, we manipulated two factors of the survey context: the alleged diagnosticity of the question set (i.e., whether it was portrayed as being sensitive to potential gender differences) and the gender of the interviewer. Consistent with previous studies of political knowledge, men scored higher than women overall. However, as predicted, this difference was reliably moderated by the manipulated factors. Women's scores were not reliably different from men's when the survey was portrayed as nondiagnostic and when women were interviewed by female interviewers. Diagnosticity and interviewer gender had no effects on men's scores. Consistent with previous research on stereotype threat, these results suggest that explicit and implicit cues reminding women of the possibility that they might confirm a negative gender stereotype can impair their retrieval of political knowledge.
Women's Benevolent Sexism as Reaction to Hostility
Authors: Fischer Ann R.
Published: November 2006

Grounded in the theory of ambivalent sexism, this study tested the speculation that women's benevolent sexist attitudes may be, in part, a self-protective response to environments they perceive as hostile to women. Data that have indirectly supported this conjecture thus far have been correlational. The current study involved a more powerful, experimental test of the hypothesis. Women ( N = 105) were randomly assigned to one of three conditions, which differed only in what participants were told about research findings on men's attitudes toward women (negative or positive attitudes, or no information). As predicted, benevolent sexist attitudes—but not hostile sexist attitudes—were strongest for women told that men hold negative attitudes toward women. This effect is consistent with a benevolent sexism-as-protest explanation and was statistically significant even while controlling for attitudes toward feminism. The differential effect of beliefs about men's attitudes on these two types of sexism lends further support to the idea that, although hostile and benevolent sexism are related, they may serve different functions.
Factors influencing liver disease progression in chronic hepatitis B
Authors: Liaw Yun‐Fan , Sollano Jose D.
Published: November 2006

Abstract: Chronic hepatitis B virus (HBV) infection is a serious health issue in the Asia‐Pacific region, where most infections are acquired perinatally or during early childhood and may lead to the development of chronic sequelae such as liver cirrhosis and hepatocellular carcinoma (HCC). Studies have identified several host factors (age, gender, immune status) and viral factors (HBV viral load, genotype, basal core promoter and other naturally occurring HBV mutations) associated with disease progression. Other factors, including lifestyle (habitual alcohol consumption, cigarette smoking), exposure to aflatoxin, and viral superinfection may also influence liver disease progression in patients with chronic HBV. This review highlights pertinent data on the factors associated with progressive HBV‐related liver disease in patients with chronic hepatitis B. An enhanced understanding of factors associated with HBV disease progression may lead to improvements in the selection of candidates for intervention and overall disease management. Interventions such as lifestyle changes and antiviral therapy may thus prevent or reduce disease progression.