bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of metabolic syndrome with impaired heart rate recovery and low exercise capacity in young male adults
Authors: Deniz Ferhat , Katircibasi Mahmut Tuna , Pamukcu Burak , Binici Suleyman , Sanisoglu S. Yavuz
Published: November 2006

Background  Impaired heart rate recovery (HRR) is a powerful predictor of overall mortality.

Aim  The aim of the present study is to assess HRR in young adult males with metabolic syndrome and to compare HRR with those of obese patients who do not meet the criteria for metabolic syndrome.

Patients and methods  Sixty‐four newly diagnosed and untreated young male subjects (24 ± 3 years) with metabolic syndrome and 40 age and sex matched obese or overweight control subjects (ages 23 ± 3 years) were enrolled in the study. All subjects performed a symptom limited exercise stress test under the standard Bruce protocol. HRR was calculated in the first, second and third minutes of the recovery period. The relationship between metabolic syndrome and HRR was evaluated via logistic regression analysis and a P‐value < 0·05 was accepted as significant.

Results  Body mass index (BMI) was 38·6 ± 3·68 and 32·22 ± 2·99 kg/m2 in the study and control groups, respectively (P < 0·001). Total cholesterol, low‐density lipoprotein (LDL) cholesterol, triglycerides, systolic and diastolic blood pressures and fasting glucose levels were significantly higher in the study group. HRR in the first minute of the recovery period and mean exercise capacity were significantly lower in the study‐group patients with metabolic syndrome (P < 0·001 and P = 0·012, respectively).

Conclusion  We determined that HRR was impaired in young adult males with metabolic syndrome compared with obese ones who do not meet the criteria of metabolic syndrome. This decreased HRR may have prognostic value in the prediction of vascular events in patients with metabolic syndrome.
Effects of grazing and ant/beetle interaction on seed production in the legume Vicia sepium in a seminatural grassland
Authors: LENOIR LISETTE , PIHLGREN AINA
Published: November 2006

Abstract 1. Seed production can be affected by cattle grazing, insect herbivores, and seed predators. Bush vetch, Vicia sepium L. (Fabaceae), possess extra floral nectaries (EFNs), which can attract ants that act as plant defenders.

2. In this field study, four different manipulations were used to investigate interactions between V. sepium, ants, aphids, and seed predators, mainly Bruchus atomarius. The experiment was set up in grazed and non‐grazed plots in a semi‐natural grassland in south‐central Sweden.

3. Grazing negatively affected number of V. sepium buds, flowers, and pods. Seed set, defined as the number of developed seeds per number of ovules in a pod, was higher in grazed plots. Ant abundance, however, was not affected by grazing. Ten different ant species were found on V. sepium and the number of ants was positively correlated with the presence of EFNs. Aphids were found only when ants were excluded from the plants. Pod and seed production of V. sepium plants was not affected by the presence of ants. The seed predator B. atomarius was not affected by the presence of ants. No support was found for the supposition that V. sepium benefited from attracting ants by producing extra floral nectar.

4. A small observational study of V. sepium plants in shrub (Rosa dumalis) plots compared with grassland plots was added to the experimental study. Vicia sepium plants were longer and had higher seed‐set (seeds/ovules) in shrub plots than in grassland plots.
Immunolocalization of duodenal cytochrome B: a relationship with circulating markers of iron status
Authors: Li A. C. Y. , Warley A. , Thoree V. , Simpson R. J. , Mckie A. T. , Kodjabashia K. , Thompson R. P. H. , Powell J. J.
Published: November 2006

Background  The brush border ferric reductase (Dcytb) is critical for the absorption of dietary iron and appears to be expressed on the duodenal enterocyte brush border. The Dcytb expression is increased in severe iron‐deficient anaemia, but the situation in a more typical mild iron deficiency is unclear. This study investigated Dcytb expression in patients with normal iron status or mild iron deficiency and its relationships with enterocyte iron status.

Materials and methods  Duodenal biopsy specimens and blood samples were obtained from 32 patients undergoing routine upper gastrointestinal endoscopy. Twenty‐three specimens (six iron‐deficient and 17 iron‐replete) were processed for light‐microscopy (LM) and for immunohistochemistry with antibodies against Dcytb and heavy/light chain ferritin subunits. The nine remaining biopsies (three iron‐deficient and six iron‐replete) were processed for electron microscopy (EM). Immunolocalization of Dcytb and intracellular ferritin was performed with appropriate primary antibodies followed by 10‐nm gold conjugate labels.

Results  The LM process showed a strong negative correlation between immunolabelling intensity of Dcytb on the enterocyte brush border and serum iron saturation (P < 0·001), but only a weak negative correlation between this antigen and haemoglobin (P = 0·08) or serum ferritin concentrations (P = 0·4). EM confirmed anti‐Dcytb preferential labelling of microvilli rather than enterocyte cytoplasm (P = 0·001), but preferential antiferritin labelling of cytoplasm (P < 0·02). There was no correlation with enterocyte cytoplasmic ferritin labelling (i.e. enterocyte iron status and Dcytb expression).

Conclusions  Enterocyte Dcytb brush border expression is increased even in mild iron deficiency and may be related to serum iron saturation. The lack of correlation with enterocyte ferritin expression deserves further study with direct measurement of intracellular iron.
AMP challenge induces a decrease in FENO in asthmatic subjects modulated by nedocromil
Authors: Bruce C. T. , Zhao D. , Yates D. H. , Thomas P. S.
Published: November 2006

Background  Allergen challenge results in an immediate reduction in exhaled nitric oxide (FENO) followed by a long‐term increase. To study mast cell activation in relation to nitric oxide (NO), the study investigated the effect of inhaled adenosine monophosphate (AMP) as a mast cell activator and mast cell stabilizer – nedocromil sodium – on FENO. The NO synthase (NOS) iso‐enzyme involved was studied by the NOS inhibitor aminoguanidine.

Materials and methods  A double‐blind, placebo‐controlled, cross‐over study was performed in two parts. Part I: eight atopic asthmatic subjects inhaled nedocromil or placebo before the AMP challenge. Spirometry and FENO were measured at intervals over a 24‐h period. Part II: seven subjects inhaled aminoguanidine before an identical protocol was used, as in Part I.

Results  Part I: AMP challenge caused a significant decrease from baseline FENO[placebo, 28·9 (20·3–37·4)%, P < 0·002 and nedocromil, 20·9 (8·2–33·6)%, P < 0·01]. Nedocromil gave partial protection against this decrease in FENO. The time‐FENO curve (AUC0–24) differed significantly between nedocromil and placebo: 2·7% (−3·6 to −9) vs. −6·6% (−12 to −1·3) FENO changes h−1, P < 0·002, respectively. Nedocromil protected against AMP‐induced bronchoconstriction (AMP PC20) [nedocromil 182 (72·5–291) mg mL−1 vs. placebo 21·7 (10·7–33) mg mL−1, P < 0·002]. Part II: nebulized aminoguanidine resulted in a significant reduction in FENO from baseline and was greater than after AMP alone (P = 0·006). Nedocromil increased AMP PC20, but no longer protected against the late decrease in FENO.

Conclusions  The AMP challenge caused a reduction in FENO as a result of prior treatment with nedocromil. Aminoguanidine abolished the nedocromil‐induced protection on the late reduction in FENO, but not on AMP PC20. Inducible NOS was implicated in the late FENO decrease after the AMP challenge.
High‐ but not low‐dose folic acid improves endothelial function in coronary artery disease
Authors: Moat S. J. , Madhavan A. , Taylor S. Y. , Payne N. , Allen R. H. , Stabler S. P. , Goodfellow J. , McDowell I. F. W. , Lewis M. J. , Lang D.
Published: November 2006

Background  While folic acid (FA) reduces plasma homocysteine (Hcy), whether the simultaneous improvement in endothelial function is dependent on Hcy lowering per se is questionable. In the present study the relationship between FA dose, Hcy lowering and endothelial function in patients with coronary artery disease (CAD) was investigated.

Materials and methods  Eighty‐four patients with CAD received either 400 µg FA or 5 mg placebo daily for a 6‐week treatment period. A further 44 patients with CAD received either 100 mg kg−1 day−1 of betaine or placebo for a 6‐week treatment period. Flow‐mediated dilatation (FMD), a measure of endothelial function, was assessed before and after the 6‐week periods. Isometric tension and Western blotting were used to investigate the effect of FA on endothelial function and endothelial nitric oxide synthase (eNOS) dimerization in isolated rabbit aortic rings and cultured porcine aortic endothelial cells (PAEC), respectively.

Results  Both 400 µg day−1 and 5 mg day−1 FA significantly increased plasma folate and decreased plasma Hcy. The FMD improved significantly after 6 weeks’ treatment of 5 mg day−1 FA but did not correlate with the reduction in Hcy. There was no change in FMD in either the 400 µg FA or placebo group. In a subgroup analysis of 11 patients in the betaine group, despite a reduced Hcy, a significant impairment in FMD was observed. In the in vitro studies FA, but not betaine, reversed methionine‐induced endothelial dysfunction. Moreover, the FA promoted eNOS dimerization in cultured PAEC.

Conclusions  These data suggest that FA dose‐dependently improves endothelial function in CAD via a mechanism independently of Hcy lowering. It may involve promotion of eNOS dimerization.
Wood CO2 efflux in a primary tropical rain forest
Authors: CAVALERI MOLLY A. , OBERBAUER STEVEN F. , RYAN MICHAEL G.
Published: November 2006

The balance between photosynthesis and plant respiration in tropical forests may substantially affect the global carbon cycle. Woody tissue CO2 efflux is a major component of total plant respiration, but estimates of ecosystem‐scale rates are uncertain because of poor sampling in the upper canopy and across landscapes. To overcome these problems, we used a portable scaffolding tower to measure woody tissue CO2 efflux from ground level to the canopy top across a range of sites of varying slope and soil phosphorus content in a primary tropical rain forest in Costa Rica. The objectives of this study were to: (1) determine whether to use surface area, volume, or biomass for modeling and extrapolating wood CO2 efflux, (2) determine if wood CO2 efflux varied seasonally, (3) identify if wood CO2 efflux varied by functional group, height in canopy, soil fertility, or slope, and (4) extrapolate wood CO2 efflux to the forest. CO2 efflux from small diameter woody tissue (<10 cm) was related to surface area, while CO2 efflux from stems >10 cm was related to both surface area and volume. Wood CO2 efflux showed no evidence of seasonality over 2 years. CO2 efflux per unit wood surface area at 25° (FA) was highest for the N‐fixing dominant tree species Pentaclethra macroloba, followed by other tree species, lianas, then palms. Small diameter FA increased steeply with increasing height, and large diameter FA increased with diameter. Soil phosphorus and slope had slight, but complex effects on FA. Wood CO2 efflux per unit ground area was 1.34±0.36 μmol m−2 s−1, or 508±135 g C m−2 yr−1. Small diameter wood, only 15% of total woody biomass, accounted for 70% of total woody tissue CO2 efflux from the forest; while lianas, only 3% of total woody biomass, contributed one‐fourth of the total wood CO2 efflux.
Projecting future N2O emissions from agricultural soils in Belgium
Authors: ROELANDT CAROLINE , DENDONCKER NICOLAS , ROUNSEVELL MARK , PERRIN DOMINIQUE , VAN WESEMAEL BAS
Published: November 2006

This study analyses the spatial and temporal variability of N2O emissions from the agricultural soils of Belgium. Annual N2O emission rates are estimated with two statistical models, MCROPS and MGRASS, which take account of the impact of changes in land use, climate, and nitrogen‐fertilization rate. The models are used to simulate the temporal trend of N2O emissions between 1990 and 2050 for a 10′ latitude and longitude grid. The results are also aggregated to the regional and national scale to facilitate comparison with other studies and national inventories. Changes in climate and land use are derived from the quantitative scenarios developed by the ATEAM project based on the Intergovernmental Panel on Climate Change‐Special Report on Emissions Scenarios (IPCC‐SRES) storylines. The average N2O flux for Belgium was estimated to be 8.6 × 106 kg N2O‐N yr−1 (STD = 2.1 × 106 kg N2O‐N yr−1) for the period 1990–2000. Fluxes estimated for a single year (1996) give a reasonable agreement with published results at the national and regional scales for the same year. The scenario‐based simulations of future N2O emissions show the strong influence of land‐use change. The scenarios A1FI, B1 and B2 produce similar results between 2001 and 2050 with a national emission rate in 2050 of 11.9 × 106 kg N2O‐N yr−1. The A2 scenario, however, is very sensitive to the reduction in agricultural land areas (−14% compared with the 1990 baseline), which results in a reduced emission rate in 2050 of 8.3 × 106 kg N2O‐N yr−1. Neither the climatic change scenarios nor the reduction in nitrogen fertilization rate could explain these results leading to the conclusion that N2O emissions from Belgian agricultural soils will be more markedly affected by changes in agricultural land areas.
Glucocorticoid‐induced tumour necrosis factor receptor family‐related receptor signalling exacerbates hapten‐induced colitis by CD4+ T cells
Authors: Lee Sun K. , Choi Beom K. , Kim Young H. , Kang Woo J. , Kim Kwang H. , Sakaguchi Shimon , Suh Jae H. , Kim Tae Y. , Kwon Byoung S.
Published: November 2006

The glucocorticoid‐induced tumour necrosis factor receptor family related gene (GITR) has been reported to be expressed on the activated T and CD4+CD25+ regulatory T cells (Treg). Signalling triggered by GITR not only neutralizes the suppressive effect of Treg cells, but also augments activation, proliferation and cytokine production of effector T cells. To test the role of GITR in 2,4,6‐trinitrobenzene sulphonic acid (TNBS)‐induced colitis − a murine model of mucosal inflammation − TNBS‐injected Balb/c mice were treated with agonistic anti‐GITR monoclonal antibody (mAb). Anti‐GITR treatment increased the death rate compared to rat IgG‐treated mice. Typically, death occurred within 4 days after the TNBS injection when the mice were treated with anti‐GITR. The mice that survived anti‐GITR treatment suffered from severe inflammation in their entire intestines. CD4+ T‐depletion protected the mice from colitis; even an anti‐GITR effect was not apparent. In contrast, CD8+ T depletion showed less protective than did CD4+ T depletion. Stimulation of GITR enhanced the production of proinflammatory cytokines including interferon (IFN)‐γ, tumour necrosis factor (TNF)‐α, interleukin (IL)‐6 and IL‐12. It also enhanced the humoral response such as serum levels of IgG2b and IgA, which was completely dependent on CD4+ T cells. Taken together, this study demonstrated that GITR signalling on CD4+ T cells is involved in the development and progress of colitis by enhancing both T helper type 1 (Th1) and Th2 type responses.
Linking recreational disturbance to population size in a ground‐nesting passerine
Authors: MALLORD JOHN W. , DOLMAN PAUL M. , BROWN ANDY F. , SUTHERLAND WILLIAM J.
Published: November 2006

There is often a perceived conflict between recreational access and wildlife conservation. Although many studies have investigated the potential effects on birds, this is the first study to demonstrate an impact of recreational disturbance on population size.

We studied the impact of disturbance on a woodlark Lullula arborea population on 16 heathland sites in southern England. These sites all had historical records of breeding woodlarks and together encompassed a range of visitor‐access levels.

A logistic regression model of patch use was used to quantify the area of habitat suitable for woodlarks. Woodlarks favoured patches with substantial proportions of bare ground and short vegetation. Across heaths, woodlark density (per hectare of suitable habitat) was lower on sites with higher levels of disturbance. Within heaths with recreational access, the probability of suitable habitat being colonized was lower in those areas with greater disturbance and was reduced to below 50% at around eight disturbance events per hour. There was no relationship between disturbance and daily nest survival rates. Birds on heaths with higher levels of disturbance fledged more chicks (per pair) because of a strong density‐dependent increase in reproductive output.

A model is presented that predicts the consequences for the woodlark population of a range of access scenarios. The impact on the population depends on both the numbers of people and their spatial distribution. Under current access arrangements, a doubling of visitor numbers has little effect, while the same number of people distributed evenly across all sites leads to a major negative impact on the population. Density‐dependent breeding success partially balances the negative effects of disturbance; however, we calculated that there is currently a 17% reduction in productivity compared with that predicted in the absence of disturbance.

Synthesis and applications. Many previous studies have stressed the negative effects of recreational disturbance on birds’ behaviour, distribution and breeding success. However, from a conservation viewpoint, the impact at the population level is of paramount importance. Modelling the population‐scale consequences of alternative access scenarios will help policymakers develop appropriate mitigation measures.
Behaviour and emotional problems in toddlers with pervasive developmental disorders and developmental delay: associations with parental mental health and family functioning
Authors: Herring S. , Gray K. , Taffe J. , Tonge B. , Sweeney D. , Einfeld S.
Published: November 2006

Background  Behavioural and emotional problems occur at a high rate in children and adolescents with intellectual disability, often from a young age. Some studies have indicated that children and adolescents with autism present with even higher rates. Less is known about the presentation, development and family impact of these difficulties in young children with autism. This study aimed to explore these issues in toddlers with pervasive developmental disorders (PDDs), those with delay without a PDD, and their families.

Methods  Participants were 123 children aged 20–51 months, referred to a developmental assessment clinic. Parents completed a checklist on child behavioural and emotional problems, and individual questionnaires on family functioning, their own mental health, and stress in relation to parenting their child. The child’s language and cognitive skills, adaptive functioning and behaviour were assessed by standardized measures. Measures were repeated 1 year postdiagnosis. Behavioural and emotional problems in young children with a PDD were compared with those in children with developmental delay without a PDD, and their impact on parental outcomes explored over time.

Results  Initial and follow‐up measures of child behaviour and emotional problems, parent mental health problems, parent stress and family functioning were significantly correlated, providing some evidence of stability over time. Child emotional and behavioural problems contributed significantly more to mother stress, parent mental health problems, and perceived family dysfunction than child diagnosis (PDD/non‐PDD), delay or gender. Compared with mothers, all fathers reported significantly less stress in relation to parenting their child.

Conclusion  Results highlighted the importance of addressing emotional and behavioural problems in very young children with autism and/or developmental delay. The need for early support and intervention for mothers, fathers and families in this context was also evidenced. As research has shown that behavioural and emotional problems persist into adolescence and young adulthood, understanding of these issues in very young children and their parents has important implications for intervention and long‐term outcomes.
The contribution of marital quality to the well‐being of parents of children with developmental disabilities
Authors: Kersh J. , Hedvat T.T. , Hauser‐Cram P. , Warfield M. E.
Published: November 2006

Background  This study examines the contribution of the marital relationship to the well‐being of both mothers and fathers of children with developmental disabilities. Parent well‐being is conceptualized in terms of mental health, parenting stress and parenting efficacy.

Methods  These analyses are based on data from 67 families participating in the Early Intervention Collaborative Study, an ongoing longitudinal investigation of the development of children with disabilities and the adaptation of their families. Multidimensional assessment techniques were used to collect data from married mothers and fathers and their child with a disability. Mother and father data were analysed separately using parallel hierarchical regression models.

Results  For both mothers and fathers, greater marital quality predicted lower parenting stress and fewer depressive symptoms above and beyond socio‐economic status, child characteristics and social support. In relation to parenting efficacy, marital quality added significant unique variance for mothers but not for fathers. For fathers, greater social support predicted increased parenting efficacy. Child behaviour was also a powerful predictor of parental well‐being for both mothers and fathers.

Conclusion  The findings support the importance of the marital relationship to parental well‐being and illustrate the value of including fathers in studies of children with developmental disabilities.
Mothers of young adults with intellectual disability: multiple roles, ethnicity and well‐being
Authors: Eisenhower A. , Blacher J.
Published: November 2006

Background  Two opposing perspectives – role strain and role enhancement – were considered as predictive of women’s psychological and physical health. The authors examined the relation between multiple role occupancy (parenting, employment, marriage) and well‐being (depression and health) among mothers of young adults with intellectual disability (ID).

Methods  Participants were 226 mothers aged 35–70 years old caring for a young adult aged 16–26 years old with moderate to severe/profound ID. Mothers were of either Latino ethnicity (n = 117) or Anglo (n = 109). Mothers’ ethnicity and degree of acculturation and young adults’ adaptive behaviour and behaviour problems were examined as potential moderators.

Results  Mothers who were employed, married, or both reported better well‐being than mothers who were both unemployed and unmarried, especially when their offspring had relatively higher adaptive functioning. This relationship between role occupancy and well‐being was fully mediated by socio‐economic status (SES) factors. Results did not suggest a role enhancement effect, but instead indicated a role shortage effect; unemployed, unmarried mothers experienced markedly poor well‐being, while all other mothers experienced comparable well‐being. Well‐being scores were higher for Anglo than for Latino mothers; this relationship was entirely accounted for by SES. In Latina mothers, the relation between role occupancy and well‐being was moderated by degree of acculturation.

Conclusions  Findings suggest that multiple roles benefit mothers of young adults with ID primarily through their impact on socio‐economic resources. For more acculturated Latina mothers, occupying more roles predicted better well‐being even after controlling for SES. Latina mothers who were unemployed and unmarried had lower SES, and this group emerged as at particular risk. The latter group may benefit most from respite assistance and other interventions aimed at addressing their physical and mental health.
Child, parent and family factors as predictors of adjustment for siblings of children with a disability
Authors: Giallo R. , Gavidia‐Payne S.
Published: November 2006

Background  Siblings adjust to having a brother or sister with a disability in diverse ways. This study investigated a range of child, parent and family factors as predictors of sibling adjustment outcomes.

Methods  Forty‐nine siblings (aged 7–16 years) and parents provided information about (1) sibling daily hassles and uplifts; (2) sibling coping; (3) parent stress; (4) parenting; and (5) family resilience. Multiple regression techniques were used.

Results  It was found that parent and family factors were stronger predictors of sibling adjustment difficulties than siblings’ own experiences of stress and coping. Specifically, socio‐economic status, past attendance at a sibling support group, parent stress, family time and routines, family problem‐solving and communication, and family hardiness‐predicted sibling adjustment difficulties. Finally, siblings’ perceived intensity of daily uplifts significantly predicted sibling prosocial behaviour.

Conclusions  The results revealed that the family level of risk and resilience factors were better predictors of sibling adjustment than siblings’ own experiences of stress and coping resources, highlighting the importance of familial and parental contributions to the sibling adjustment process. The implications of these results for the design of interventions and supports for siblings are discussed.
Personality, coping style and well‐being of parents rearing children with developmental disabilities
Authors: Glidden L. M. , Billings F. J. , Jobe B. M.
Published: November 2006

Background  Parents with children with developmental disabilities (DD) encounter a variety of stressors associated with rearing their children and must develop effective coping mechanisms in order to adapt successfully to these challenges. Previous research has failed to establish the role of parental individual differences in the reported use of different coping strategies. The current study explores parental personality and whether children with DD were adopted or born into the families and their influence on the coping strategies used by mothers and fathers.

Methods  A total of 97 mother–father dyads rearing at least one child with DD were participants. They narrated stressful situations related to their child and completed the Ways of Coping Questionnaire twice. Data were also collected with regard to personality, depression and subjective well‐being (SWB).

Results  Both adoptive and birth mothers and fathers used more problem‐focused than emotion‐focused strategies. Personality factors, Neuroticism especially, were predictive of coping strategy use. Higher levels of Positive Reappraisal were associated with higher levels of SWB, whereas higher levels of Escape‐Avoidance were associated with lower levels of SWB, but only for mothers. Results were consistent with a dispositional model of strategy use in that frequency of use was associated with personality characteristics, was consistent over time, and for different children in the same families. Future research should focus on the persistence of the associations between strategy use and well‐being and whether they hold true at different stages of the lifespan when coping contexts may change quite dramatically.
Facies, geometry and geological significance of Late Ordovician (early Caradocian) coral bioherms: Lourdes Formation, western Newfoundland
Authors: BATTEN HENDER KELLY L. , DIX GEORGE R.
Published: November 2006

Late Ordovician coral bioherms in the Lourdes Formation of western Newfoundland exhibit a complex mixing of architectural elements, including framework, boundstone and suspension deposits. The bioherms occur within a narrow (16 m) stratigraphic interval, and a prominent unconformity truncates the interval of bioherm growth and tops of many of the bioherms. The buildups developed along a carbonate ramp. They occur isolated and in groups, individuals in groups are aligned in parallel orientation. The sizes of the bioherms range from small (50–100 cm) coral piles to columnar and dome‐shaped masses (1–15 m); however, topographic relief was never more than ≈1 m. Bioherm construction reflects: (i) stacking of the tabulate coral Labyrinthites chidlensis, and less common stromatoporoids; (ii) accumulation of microbial‐stromatoporoid boundstone and suspension deposits within shelter cavities between corals; and (iii) detrital bioherm‐flank skeletal grainstone beds. Trypanites borings are common in the tops of coral heads. The bioherms exhibit three growth‐development stages: (i) seafloor stabilization, wherein rare, abraded coral colonies lie scattered within pelmatozoan/skeletal grainstone lenses; (ii) colonization, wherein corals (L. chidlensis), rare stromatoporoids (Labechia sp.), and other biota (bryozoans) produced a bioherm overlying the basal sediment base; and (iii) diversification, which is marked by a more diverse range of fauna and flora as well as occurrence of shelter‐cavity deposits. The diversification stage usually makes up more than 70% of a bioherm structure, and, in some defines multiple periods of start‐up and shut‐down of bioherm growth. The latter is defined by bored omission surfaces and/or deposition of inter‐bioherm sediment. The Lourdes bioherms have a similar ecological structure, biotic diversity and depositional environment to patch reefs in the equivalent Carters Limestone in Tennessee. The mixture of coral stacking and boundstone as architectural elements identify an Early Palaeozoic transition of reef‐design development along shallow‐water platforms that began to displace the muddy (boundstone, bafflestone) carbonate buildups more typical of the Early and Middle Ordovician time.
Form, function and feedbacks in a tidally dominated ooid shoal, Bahamas
Authors: RANKEY EUGENE C. , RIEGL BERNHARD , STEFFEN KELLEY
Published: November 2006

Although the general aspects of oolitic depositional systems are well documented, seascape‐scale (≈103–106 m2) patterns of oolitic shoals and the details of processes acting on them are not well understood or quantified. To begin to fill this basic gap in understanding, this paper describes the morphology and hydrodynamics of Lily Bank, a Modern tidally dominated Bahamian ooid shoal. In this study, integrating remote sensing imagery with quantitative, geo‐located bathymetrical, hydrological and granulometric data in a Geographic Information System documents geomorphic and sedimentological patterns and facilitates interpreting these patterns in the context of the processes operating in this system. The results of these analyses reveal that parabolic bars up to several kilometres in wavelength and several metres in height form a common morphologic motif, although there is considerable variation on that general theme. The seascape‐scale configuration of bars and superimposed sedimentary structures is closely linked to spatial patterns of tidal movements, and includes the presence of mutually evasive flood and ebb channels. Sedimentologically, bars are neither homogenous nor random bodies; instead, granulometric parameters such as sorting and percentage mud vary systematically, as shaped by hydro‐geomorphic controls. The best sorted, coarsest ooids are on bar crests, whereas the finest grains are found in the lower energy, deeper interior and flanking regions. In short, results clearly document hydrodynamic‐bathymetrical influences on these ooid shoals and their granulometry, linkages akin to siliciclastic analogues. Sedimentological, hydrodynamic and geomorphic observations are consistent with a conceptual model for the formation of parabolic bars in which initial irregularities in non‐parabolic bars are enhanced through their effect of focusing flow. Constricted flow leads to higher flow velocities, tidal flow velocity asymmetries, differential net sediment transport and growth of bathymetrical highs. This bathymetrical divergence creates separate paths for flood‐ and ebb‐tides, facilitating emergence of better‐developed parabolic forms. The resultant parabolic geometries and component bedforms appear to be either in dynamic equilibrium with both ebb‐ and flood‐tide flows, or evolving toward that state. In exploring patterns and processes within carbonate shoals, this study illustrates some of the first documented insights on quantitative details of morphology and dynamics and in the links between geomorphic framework and grain‐size and sorting in an oolitic carbonate system. Assuming a continuity of processes between ancient and modern, the insights from this shoal provide information on possible facies geometries and on the characteristics of grains and depositional porosity of analogous facies within ancient ooid shoals.
Evolution of a Holocene delta driven by episodic sediment delivery and coseismic deformation, Puget Sound, Washington, USA
Authors: BARNHARDT WALTER A. , SHERROD BRIAN L.
Published: November 2006

Episodic, large‐volume pulses of volcaniclastic sediment and coseismic subsidence of the coast have influenced the development of a late Holocene delta at southern Puget Sound. Multibeam bathymetry, ground‐penetrating radar (GPR) and vibracores were used to investigate the morphologic and stratigraphic evolution of the Nisqually River delta. Two fluvial–deltaic facies are recognized on the basis of GPR data and sedimentary characteristics in cores, which suggest partial emplacement from sediment‐rich floods that originated on Mount Rainier. Facies S consists of stacked, sheet‐like deposits of andesitic sand up to 4 m thick that are continuous across the entire width of the delta. Flat‐lying, highly reflective surfaces separate the sand sheets and comprise important facies boundaries. Beds of massive, pumice‐ and charcoal‐rich sand overlie one of the buried surfaces. Organic‐rich material from that surface, beneath the massive sand, yielded a radiocarbon age that is time‐correlative with a series of known eruptive events that generated lahars in the upper Nisqually River valley. Facies CF consists of linear sandbodies or palaeochannels incised into facies S on the lower delta plain. Radiocarbon ages of wood fragments in the sandy channel‐fill deposits also correlate in time to lahar deposits in upstream areas. Intrusive, sand‐filled dikes and sills indicate liquefaction caused by post‐depositional ground shaking related to earthquakes. Continued progradation of the delta into Puget Sound is currently balanced by tidal‐current reworking, which redistributes sediment into large fields of ebb‐ and flood‐oriented bedforms.
Geochemical and Nd isotope composition of detrital sediments on the north margin of the South China Sea: provenance and tectonic implications
Authors: YAN YI , XIA BIN , LIN GE , CARTER ANDY , HU XIAOQIONG , CUI XUEJUN , LIU BAOMING , YAN PIN , SONG ZHENGJIANG
Published: November 2006

A major re‐organization of regional drainages in eastern Tibet and south‐western China took place in the Cenozoic as deformation from the growing Himalayas and Tibetan Plateau affected an increasingly wider area. The effects of these changes on the regional sediment routing systems is not well constrained. This study examines the geochemical and Nd signatures of sedimentary rocks from the Ying‐Qiong and Nanxiong basins on the northern margin of the South China Sea to constrain and identify any significant changes in sediment source. Upper Cretaceous to Lower Eocene sedimentary rocks in the Nanxiong Basin show higher Th/Sc, La/Sc, Th/Cr and Th/Co ratios and lower Eu/Eu* ratios than PAAS (post‐Archaean Australian Shale), which indicates that Palaeozoic sedimentary rocks of the South China Block were the main basin sediment source. In contrast, Oligocene to Pleistocene sedimentary rocks of the Ying‐Qiong Basin show an abrupt change in these trace‐element ratios between 16·3 and 10·4 Ma, indicating a mid‐Miocene shift in provenance. ɛNd values from the Ying‐Qiong Basin (range = −11·1 to −2·1) reinforce this, with pre‐13·8 Ma sedimentary rocks having average ɛNd of −5·6 (range = −2·1 to −7·4), and post‐13·8 Ma sedimentary rocks having average ɛNd of −9·3 (range = −8·7 to −11·1). During the Oligocene, the centre of rifting transferred south and basins on the north margin of the South China Sea experienced rapid subsidence. Further uplift and erosion then exposed Mesozoic and Cenozoic granites that supplied large amounts of granitic detritus, especially to the Ying‐Qiong Basin. Then a change occurred at ca 13 Ma resulting in less input from local sources (i.e. the fault blocks formed by Mesozoic‐Cenozoic tectonics and magmatism) to an increasing contribution of older continental material, mostly from Indochina to the west of the South China Sea.
Lithofacies and origin of late Quaternary mass transport deposits in submarine canyons, central Scotian Slope, Canada
Authors: JENNER KIMBERLEY A. , PIPER DAVID J. W. , CAMPBELL D. CALVIN , MOSHER DAVID C.
Published: November 2006

Mass transport deposits, up to 3·9 m thick, have been identified from piston cores collected from canyon floors and inter‐canyon ridges on the central Scotian Slope. These deposits are characterized by four distinct mass‐transport facies – folded mud, dipping stratified mud, various types of mud‐clast conglomerate, and diamicton. Commonly, the folded and stratified mud facies are overlain by mud‐clast conglomerate, followed by diamicton and then by turbidity current deposits of well‐sorted sand. Stratified and folded mud facies were sourced from canyon walls. Overconsolidation in clasts in some mud‐clast conglomerates indicates that the source sediment was buried 12–33 m, much deeper than the present cored depth, implying a source in canyon heads and canyon walls. The known stratigraphic framework for the region and new radiocarbon dating suggests that there were four or five episodes of sediment failure within the past 17 ka, most of which are found in more than one canyon system. The most likely mechanism for triggering occasional, synchronous failures in separate canyons is seismic ground shaking. The facies sequence is interpreted as resulting from local slides being overlain by mud‐clast conglomerate deposits derived from failures farther upslope and finally by coarser‐grained deposits resulting from retrogressive failure re‐mobilizing upper slope sediments to form debrisflows and turbidity currents.
Holocene evolution of the Anichab Pan on the south‐west coast of Namibia
Authors: COMPTON JOHN S.
Published: November 2006

Coastal sediment‐filled depressions (pans) are one of the few areas that contain Quaternary records of sea‐level and palaeoenvironmental change along the western margin of southern Africa. Anichab is a 128 km2 salt‐encrusted pan on the hyper‐arid southern coast of Namibia with an emergent, well‐preserved and in‐place mid‐Holocene mollusc assemblage. The molluscs are typical of subtidal sands on the sheltered side of offshore islands but include several warm‐water species no longer found living along this coast. The Holocene evolution of the pan was largely influenced by changes in sea level and supply of sand along the coast. Calibrated radiocarbon ages of mollusc shells indicate a maximum Holocene sea level of ca 2 m above mean sea level (msl) from 7·0 to 6·3 ka and a return to near present‐day sea level by 5·3 ka. The pan surface is 2 m below msl and has been emergent since 4·9 ka from the build up of sandy beaches and coastal dunes. A thin (1–4 cm) halite crust occurs over much of the pan surface but a layer of halite‐cemented sand up to 40 cm thick is restricted to the central pan. Gypsum occurs near the subsurface brine interface and is limited by calcium to the edges of the pan. Nodules of calcite‐cemented sand are forming in brackish, relatively high alkalinity subsurface waters in the south‐east corner of the pan and nodules of aragonite‐cemented sand are forming in brines 1 m below the central pan surface. Although modern dolomite has been reported from coastal lagoons of Brazil and Australia, carbonate cements are a minor feature of Anichab Pan and dolomite was restricted to a single reworked nodule most likely of Late Pleistocene age. Therefore, Anichab Pan does not appear to be a modern analogue to extensive, mixed‐water dolomite cements found in Upper Pleistocene sediment‐filled depressions on the Namibian shelf.
Factors affecting the nature and rate of dust production from natural dune sands
Authors: BULLARD JOANNA E. , MCTAINSH GRANT H. , PUDMENZKY CHRISTA
Published: November 2006

This paper evaluates the influence of natural sand particle characteristics on the amount and particle‐size distributions of dust produced by aeolian abrasion. It contrasts with previous studies of aeolian abrasion by conducting experiments using: (i) whole sand samples, as opposed to selected size fractions; (ii) natural, mature dune sands, rather than artificial or freshly crushed material; and (iii) weathered sands that have acquired a superficial clay coating, instead of grains with clean surfaces. Whilst previous research has found clear, positive relationships between particle size, sorting, roundness and the amount of dust produced by aeolian abrasion, the relationships determined in this study show some variation according to the geomorphological context from which the original samples were obtained. The most important factor affecting the amount and particle‐size characteristics of the dust produced was the presence of a clay coating on the grain surface that is removed by the abrasion process. The dust produced by this mechanism had a modal size of 2–5 μm and material <10 μm comprised up to 90% of the particles produced.
Formation and preservation of open‐framework gravel strata in unidirectional flows
Authors: LUNT I. A. , BRIDGE J. S.
Published: November 2006

Open‐framework gravel (OFG) in river deposits is important because of its exceptionally high permeability, resulting from the lack of sediment in the pore spaces between the gravel grains. Fluvial OFG occurs as planar strata and cross strata of varying scale, and is interbedded with sand and sandy gravel. The origin of OFG has been related to: (1) proportion of sand available relative to gravel; (2) separation of sand from gravel during a specific flow stage and sediment transport rate (either high, falling or low); (3) separation of sand from gravel in bedforms superimposed on the backs of larger bedforms; (4) flow separation in the lee of dunes or unit bars. Laboratory flume experiments were undertaken to test and develop these theories for the origin of OFG. Bed sediment size distribution (sandy gravel with a mean diameter of 1·5 mm) was kept constant, but flow depth, flow velocity and aggradation rate were varied. Bedforms produced under these flow conditions were bedload sheets, dunes and unit bars. The fundamental cause of OFG is the sorting of sand from gravel associated with flow separation at the crest of bedforms, and further segregation of grain sizes during avalanching on the steep lee side. Sand in transport near the bed is deposited in the trough of the bedform, whereas bed‐load gravel avalanches down the leeside and overruns the sand in the trough. The effectiveness of this sorting mechanism increases as the height of the bedform increases. Infiltration of sand into the gravel framework is of minor importance in these experiments, and occurs mainly in bedform troughs. The geometry and proportion of OFG in fluvial deposits are influenced by variation in height of bedforms as they migrate, superposition of small bedforms on the backs of larger bedforms, aggradation rate, and changes in sediment supply. If the height of a bedform increases as it migrates downstream, so does the amount of OFG. Changes in the character of OFG on the lee‐side of unit bars depend on grain‐size sorting in the superimposed bedforms (dunes and bedload sheets). Thick deposits of cross‐stratified OFG require high bedforms (dunes, unit bars) and large amounts of aggradation. These conditions might be expected to occur during high falling stages in the deeper parts of river channels adjacent to compound‐bar tails and downstream of confluence scours. Increase in the amount of sand supplied relative to gravel reduces the development of OFG. Such increases in sand supply may be related to falling flow stage and/or upstream erosion of sandy deposits.
Desensitization strategies enabling successful renal transplantation in highly sensitized patients
Authors: Beimler J.H.M. , Susal C. , Zeier M.
Published: November 2006

Abstract:  Currently, the number of highly sensitized patients awaiting a renal transplant is increasing on the waiting lists of different organ exchange organizations. Due to the presence of antibodies against a broad variety of human leukocyte antigen (HLA) specificities, highly sensitized patients have a markedly reduced chance of receiving a crossmatch‐negative organ. It has long been recognized that hyperacute rejection is associated with the presence of donor‐specific anti‐HLA antibodies at the time of transplantation. Meanwhile treatment protocols have been developed to achieve successful transplantation across antibody barriers. Therefore, the presence of donor‐specific anti‐HLA antibodies and a positive serological crossmatch are no longer considered as an absolute contraindication to renal transplantation. Mainly, two desensitization protocols have been established in order to overcome a positive crossmatch or to enhance the chance of highly sensitized patients to receive a crossmatch‐negative organ: high‐dose intravenous immunoglobulin (IVIg) or low‐dose IVIg in combination with plasmapheresis. Herein, we summarize the characteristics of these two treatment regimes along with other alternative approaches that are currently used for the management of kidney graft recipients with broad alloantibody reactivity against potential kidney donors.
Real‐time contrast‐enhanced sonography in renal transplant recipients
Authors: Schwenger Vedat , Hinkel Ulrich‐Paul , Nahm Anna‐Maria , Morath Christian , Zeier Martin
Published: November 2006

Abstract:  Conventional colour Doppler ultrasonography (CDUS) is a well‐established and the most frequently used imaging procedure to diagnose kidney allograft dysfunction. Unfortunately, this technique is limited to the estimation of the allograft perfusion in large arteries. Early diagnosis of vascular damage, i.e., chronic allograft nephropathy is essential for an early therapeutic intervention. CDUS is still limited in interpreting vascular integrity. In contrast‐enhanced sonography (CES) is a feasible technique for quantitative analysis of kidney perfusion and early diagnosis of biopsy proven chronic allograft nephropathy. CES does not provide only quantitative information on microvascular perfusion of the renal allografts but also represents improved diagnostic significance compared with CDUS for the detection of chronic allograft nephropathy.
General aspects and pitfalls in liver transplant pathology
Authors: Longerich Thomas , Schirmacher Peter
Published: November 2006

Abstract:  Pathology in a liver transplant setting addresses four different topics: establishment of a definite diagnosis of the liver disease before listing for transplantation, evaluation of the donor liver with regard to pre‐existing diseases, in particular macrovesicular steatosis and fibrosis, assessment of the hepatectomy specimen, and post‐transplant biopsy evaluation. Of these, post‐transplant biopsy evaluation is the most challenging and clinically the most relevant issue. It requires fast diagnoses to facilitate specific treatment and it has to incorporate a broad spectrum of differential diagnoses. Precise knowledge about rejection, post‐transplant therapy, pathology of immunosuppression, and recurrence of the initially underlying liver disease including the characteristic time peaks and atypical histological presentations (e.g., fibrosing cholestatic hepatitis) is needed to evaluate specific and combined histological pictures of liver damage. For adequate interpretation of post‐transplant biopsies the hepatopathologist has to be informed about the essential clinico‐anamnestic aspects such as time course, medication, imaging results, and serology.