bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification and characterization of novel low‐density lipoprotein receptor mutations of familial hypercholesterolaemia patients in Taiwan
Authors: Charng M. J. , Chiou K. R. , Chang H. M. , Cheng H. M. , Ye Z. X. , Lin S. J. 
Published: November 2006

AbstractBackground Familial hypercholesterolaemia (FH) is an autosomal dominant disease associated with a very high risk of coronary vascular disease. The study objective was to identify patients with FH in Taiwan and characterize novel mutations.Materials and methods Fifty‐one patients with suspected FH living in Taiwan were screened for mutations in both the low‐density lipoprotein (LDL) receptor and the apolipoprotein (apoB) genes using the multiplex polymerase chain reaction and exon‐by‐exon DNA sequencing technique. Functional consequences on LDL receptor activity were characterizedin vitrofor novel mutations and family pedigree was also analyzed.Results Thirteen different functional mutations in the LDL receptor gene and one mutation in the apoB gene were found in 21 patients. Among the 13 mutations in the LDL receptor gene, 10 were single‐point missense mutations, one was a two‐point mutation in the same allele, one was a non‐sense mutation and one was a frame‐shift mutation. There were three novel mutations, including two missense mutations (M510K and W512R) and one frame‐shift mutation (1953 delTA mutation). The characterization of missense M510K retained 36·2% of the activity of the normal receptor. Conversely, frame‐shift 1953 delTA and missense W512R led to defective proteins, with only 0–6% of normal receptor activity.Conclusions The study identified 13 LDL receptor gene mutations and characterized three novel mutations causing FH in Taiwan. This facilitated a better understanding of FH among the Chinese population and may enable diagnosis of FH at the molecular level at a presymptomatic, early age.
ApoA‐I mutants V156K and R173C promote anti‐inflammatory function and antioxidant activities
Authors: Cho K. H. , Park S. H. , Han J. M. , Kim H. C. , Choi Y. K. , Choi I. 
Published: November 2006

AbstractBackground  Two mutants of apolipoprotein (apo) A‐I, V156K and A158E, showed markedly different structural and functional properties in lipid‐free and lipid‐bound states in the authors’ earlier report. The physiological activities of these mutants were compared with the wild‐type (WT) and R173C mutant using in vitro and in vivo experiments.Materials and methods  A reconstituted high‐density lipoprotein (rHDL) with palmitoyloleoyl phosphatidylcholine (POPC), combined with each of the apoA‐I variants, was injected into the tail‐veins of hypercholesterolaemic mice (C57BL6/J), which had been fed a high cholesterol and high fat (HCHF; 0·5% cholesterol, 15% lard, 0·1% sodium cholate) diet for 23 weeks, once at 0 h and then every 24 h, at a dosage of 30 mg apoA‐I kg−1 of body‐weight.Results  The V156K‐rHDL and R173C‐rHDL exhibited significantly stronger anti‐oxidant activity against copper‐mediated low‐density lipoprotein (LDL) oxidation than did A158E in an apolipoprotein state. The mice injected with WT‐rHDL or A158E‐rHDL showed abrupt increases in total cholesterol concentrations (47% and 38%, respectively) as compared with the levels before injection, whereas the mice injected with V156K‐rHDL and R173C‐rHDL did not. Injection with V156K‐rHDL improved serum lipids and anti‐oxidative activities compared with the injection of WT‐rHDL. Injection of WT‐rHDL or A158E‐rHDL increased serum interleukin‐6 (IL‐6) to 90–110 pg mL−1, whereas the injection of V156K‐rHDL or R173C‐rHDL increased serum IL‐6 to 17–25 pg mL−1 only.Conclusion  The V156K‐rHDL and R173C‐rHDL displayed potent beneficial effects, including anti‐oxidant and anti‐inflammatory activity from both in vitro and in vivo evaluations, whereas the WT‐rHDL and A158E‐rHDL did not.
Nitrogen sedimentation in a lake affected by massive nitrogen inputs: autochthonous versus allochthonous effects
Authors: PIÑA‐OCHOA ELISA , ALVAREZ‐COBELAS MIGUEL , RODRIGO MARIA A. , ROJO CARMEN , DELGADO ANTONIO 
Published: November 2006

Summary1. Monthly changes to N loadings, in‐lake particulate organic nitrogen (PON), planktonic PON, and PON sedimentary flux were studied in a Spanish flowthrough, seepage lake subject to massive nitrogen inputs from June 2003 to December 2004 when water renewal was very rapid (0.09–0.17 year).2. The distribution of in‐lake PON did not show a seasonal trend. Total nitrogen input flux ranged from 1.23 to 4.83 g N m−2 day−1, 71–76% of which is nitrate while PON represents 6–10%. PON sedimentation rates ranged from 9 to 90 mg N m−2 day−1 and fluctuated on a seasonal basis, reaching a minimum in winter and early spring and a maximum after thermal turnover had occurred.3. This fluctuation was not related to either autochthonous planktonic production or allochthonous inputs. Since charophyte populations in Colgada Lake underwent a seasonal pattern of growth and decomposition, and 15δN values of settling material peaked at the end of that decomposition process, we suggest that PON sedimentary flux could be partly driven by decomposed charophyte particles.4. However, the picture of PON sedimentation in this lake was more complex than anticipated because water residence time partly explained PON variability, albeit with a 1 month lag. Water residence time explained 40% of the overall variance of yearly averaged PON sedimentary flux in a meta‐analysis of 13 lakes worldwide. However, the factors such as phytoplankton composition, trophic structure, bottom communities, nutrient loading or productivity levels may also be influential on PON settling dynamics.
Assessing the vulnerability of endemic diatom species in Lake Baikal to predicted future climate change: a multivariate approach
Authors: MACKAY ANSON W. , RYVES D. B. , MORLEY D. W. , JEWSON D. H. , RIOUAL P. 
Published: November 2006

AbstractDiatoms in Lake Baikal exhibit significant spatial variation, related to prevailing climate, lake morphology and fluvial input into the lake. Here we have assessed the threats to endemic planktonic diatom species (through the development of empirical models), which form a major component of primary production within the lake. Multivariate techniques employed include redundancy analysis (RDA) and Huisman–Olff–Fresco (HOF) models. Our analyses suggest that eight environmental variables were significant in explaining diatom distribution across the lake, and in order of importance these are snow thickness on the ice, water depth, duration of days with white ice, suspended matter in the lake, days of total ice duration, temperature of the water surface in July, concentration of zooplankton and suspended organic matter. Impacts on dominant phytoplankton diatom species are highlighted using t‐value biplots. Predictions of future climate change on Lake Baikal are likely to result in shorter periods of ice cover, decreased snow cover across the lake in spring, increased fluvial input into the lake, and an increase in the intensification of surface water stratification during summer months. All these factors are likely to impact negatively on the slow‐growing, cold‐water endemics such as Aulacoseira baicalensis and Cyclotella minuta, which currently dominate diatom assemblages. Instead, taxa that are only intermittently abundant, at present, in offshore areas (e.g. Stephanodiscus meyerii) are likely to become more frequent. However, given the climatic gradient across the lake, the timing and extent of changes in community structure are likely to vary. Moreover, palaeolimnological records show that Lake Baikal diatom assemblages have been dynamic throughout the Holocene, with both endemic and cosmopolitan species exhibiting periods of dominance. Effects of climate change on the entire lake ecosystem may yet be profound as the structure of the pelagic food web may change from one based on endemic diatom taxa to one dominated by nondiatom picoplankton, and as limnological functioning (e.g. stratification and mixing) affects deepwater oxygen availability, nutrient cycling and trophic linkages.
Constraining rooting depths in tropical rainforests using satellite data and ecosystem modeling for accurate simulation of gross primary production seasonality
Authors: ICHII KAZUHITO , HASHIMOTO HIROFUMI , WHITE MICHAEL A. , POTTER CHRISTOPHER , HUTYRA LUCY R. , HUETE ALFREDO R. , MYNENI RANGA B. , NEMANI RAMAKRISHNA R. 
Published: November 2006

AbstractAccurate parameterization of rooting depth is difficult but important for capturing the spatio‐temporal dynamics of carbon, water and energy cycles in tropical forests. In this study, we adopted a new approach to constrain rooting depth in terrestrial ecosystem models over the Amazon using satellite data [moderate resolution imaging spectroradiometer (MODIS) enhanced vegetation index (EVI)] and Biome‐BGC terrestrial ecosystem model. We simulated seasonal variations in gross primary production (GPP) using different rooting depths (1, 3, 5, and 10 m) at point and spatial scales to investigate how rooting depth affects modeled seasonal GPP variations and to determine which rooting depth simulates GPP consistent with satellite‐based observations. First, we confirmed that rooting depth strongly controls modeled GPP seasonal variations and that only deep rooting systems can successfully track flux‐based GPP seasonality at the Tapajos km67 flux site. Second, spatial analysis showed that the model can reproduce the seasonal variations in satellite‐based EVI seasonality, however, with required rooting depths strongly dependent on precipitation and the dry season length. For example, a shallow rooting depth (1–3 m) is sufficient in regions with a short dry season (e.g. 0–2 months), and deeper roots are required in regions with a longer dry season (e.g. 3–5 and 5–10 m for the regions with 3–4 and 5–6 months dry season, respectively). Our analysis suggests that setting of proper rooting depths is important to simulating GPP seasonality in tropical forests, and the use of satellite data can help to constrain the spatial variability of rooting depth.
Direct and indirect effects of the most widely implemented Dutch agri‐environment schemes on breeding waders
Authors: VERHULST JORT , KLEIJN DAVID , BERENDSE FRANK 
Published: November 2006

Summary

In the Netherlands, agri‐environment schemes are an important tool for halting the ongoing decline of meadow birds and, in particular, waders breeding on wet meadows. The effectiveness of the main scheme, postponed mowing, is heavily debated because it does not result in higher breeding densities. Recently, agri‐environmental collectives have become involved in the co‐ordination of scheme applications and additional measures have been introduced. One of them is per‐clutch payment: farmers are paid per wader clutch without being restricted in their farming practices.
We evaluated the effectiveness of the combination of the two measures, postponed mowing and per‐clutch payment, by determining the number of birds and territories on 12·5‐ha plots where both measures (on average 1·6 ha postponed mowing and 10·9 ha per‐clutch payment) were being implemented. Conventionally managed grasslands served as controls. Additionally, on a field with postponed mowing and a paired control field, we measured a number of environmental factors that might influence wader distribution.
On plots operating a combination of postponed mowing and per‐clutch payment, more territories of all bird species were found and more redshanks Tringa totanus were observed. The same pattern occurred on fields with per‐clutch payment alone. On fields with postponed mowing alone, we found more territories of the most abundant wader species but on conventional fields we observed more lapwings Vanellus vanellus.
The positive effects of postponed mowing on wader territories were probably caused by small differences in soil moisture and groundwater level between the two field types, as inclusion of these factors in a general linear model rendered all scheme effects insignificant.
Postponed mowing affected the form and amount of fertilizer applied to the fields as well as available nitrogen, but none of the other environmental factors that were measured. Additional analyses identified groundwater depth, penetration resistance and prey density (earthworms, Lumbricidae, and leatherjackets, Tipulidae larvae) as the main factors determining wader density.
Synthesis and applications. Our results show that conservation measures consisting of postponed mowing and per‐clutch payment implemented by agri‐environment collectives do not support a higher abundance of waders but do support marginally higher breeding densities of waders compared to conventional farms. These results are probably due to differences in soil moisture and groundwater depth. The effectiveness of agri‐environment schemes directed towards conservation of waders might be enhanced by including raised groundwater levels into scheme prescriptions.
Cognitive perturbation through dynamic modelling: a pedagogical approach to conceptual change in science
Authors: Li S. C. , Law N. , Lui K. F. A. 
Published: November 2006

AbstractWhile simulations have widely been used to facilitate conceptual change in learning science, results indicate that significant disparity or gap between students' prior conceptions and scientific conceptions still exists. To bridge the gap, we argue that the applications of computer simulation in science education should be broadened to enable students to model their thoughts and to improve and advance their theories progressively. While computer simulations are often used to offer opportunities for students to explore scientific models, they do not give them the space to explore their own conceptions, and thus cannot effectively address the challenge of changing students' alternative conceptions. Findings from our recent empirical study reveal that, firstly, dynamic modelling using the environment WorldMaker 2000 in conjunction with the use of a cognitive perturbation strategy by the teacher was effective in helping students to migrate from their alternative conceptions towards a more scientifically inclined one; secondly, the pathways of conceptual change across groups were idiosyncratic and diverse. Respecting students' ideas seriously and providing cognitive perturbation at appropriate junctures of the inquiry process are found to be conducive to fostering conceptual change. In this paper, we will report on the details of the pedagogical approach adopted by the teacher and portray how students' conceptions change during the entire process of model building.
Achieving educational technology standards: the relationship between student teacher's interest and institutional support offered
Authors: Kadijevich Dj. 
Published: November 2006

AbstractHaving in mind the need for an increased attention to the importance of pre‐service teacher development concerning technology, this study examined teachers' interest to attain educational technology standards (Interest) in terms of their computer attitude (Attitude) and the professional support they received to attain these standards (Support). The study used a sample of 39 mathematics student teachers and 62 elementary student teachers. The two groups only differed in Support favouring elementary student teachers, who, contrary to mathematics student teachers, received some basic instruction concerning ET standards.Despite these differences in Support, the two‐group path analysis applied revealed that, for both student teachers, the direct effects of Support on Attitude and of Attitude on Interest were positive and significant. On the other hand, the total and direct effects of Support on Interest, although positive, were insignificant. However, because of significant indirect effects, the impact of Support on Interest was mediated through Attitude in both groups. These findings support the view that in order to develop Interest, Support should focus on developing Attitude, which may hold true in general not depending on student teacher type and the level of Support. Implications for further research and (pre‐service) teacher professional development are examined.
Promotion and prevention orientations in the choice to attend lectures or watch them online
Authors: Bassili J. N. 
Published: November 2006

AbstractWhen presented with the option to use a new instructional technology, students often face an approach–avoidance conflict. This study explored promotion and prevention orientations, concepts linked to approach and avoidance in Higgins's regulatory focus theory, in the choice to attend lectures or watch them online. Openness, a core disposition in the Big Five Model of personality, and positive attitudes towards the utility of the Internet, reflect promotion orientations that are potentially related to the choice to watch lectures online. By contrast, neuroticism, another core disposition in the Big Five Model, and anxiety about the Internet as a computer technology, reflect a prevention orientation that is potentially related to the choice of attending lectures in class. The results illustrate that both promotion and prevention are at work in the choice to attend lectures or to watch them online. Neuroticism and anxiety about the Internet as a computer technology were related to the choice to attend lectures in class, whereas the perceived utility of the Internet was related to the choice to watch lectures online. Instructional mode choice was not related to examination performance, suggesting that the choice to attend lectures or watch them online has more to do with individual differences in promotion and prevention orientations than with pedagogical characteristics that impact learning.
Invertebrate herbivory during the regeneration phase: experiments with a freshwater angiosperm
Authors: ELGER A. , DE BOER T. , HANLEY M. E. 
Published: November 2006

SummaryInvertebrate grazing during the regeneration phase is well known to exert a strong structuring effect in terrestrial plant communities. However, very few studies have investigated the effect of invertebrate herbivores on regenerating freshwater angiosperms, despite the obvious benefits for the development of general theories in plant community ecology.Our study investigated the parameters that determine the sensitivity of the freshwater macrophytePotamogeton pectinatusL. to herbivory by the pond snailLymnaea stagnalis(L.).P. pectinatuswas raised from winter‐collected tubers in aquatic microcosms and submitted to grazing by snails at various densities and starvation levels.Newly sproutedP. pectinatuswas much more sensitive to snail grazing than mature plants: survival of newly sprouted plants decreased as snail density increased, whereas the survival rate of mature plants was unaffected by snail density. Moreover, the sensitivity of newly sproutedP. pectinatusto herbivory decreased as its initial tuber mass increased. The damage to newly sproutedP. pectinatusby herbivory increased with snail starvation. However, the presence of an alternative, highly palatable, food (i.e. benthic algae) deflected feeding onP. pectinatus, even by extremely hungry snails.These results demonstrate the potential structuring role exerted by gastropods during the regeneration of freshwater macrophytes, supporting results from terrestrial systems. They also suggest that regenerating plants may avoid invertebrate herbivory by modulating their intrinsic characteristics (e.g. increasing propagule size) or by emerging under favourable environmental conditions (e.g. low invertebrate density, presence of alternative food). Herbivory during the regeneration phase is therefore pivotal to our understanding of plant dynamics in aquatic as well as terrestrial ecosystems, and should be integrated into explicative models of vegetation patterns across various environments.
Families challenged by and accommodating to the adolescent years
Authors: Schneider J. , Wedgewood N. , Llewellyn G. , McConnell D. 
Published: November 2006

AbstractBackground  Informed by Ecocultural theory, this study explores the challenges that families caring for an adolescent with disability face and strategies they apply to sustain a meaningful family routine during the adolescent years.Methods  In‐depth Ecocultural interviews were conducted with 20 families caring for an adolescent (aged 10–21 years) with severe disabilities, including intellectual disability. Transcripts were analysed using a constant comparative approach. Two types of family level challenges were differentiated – internal and external factors impacting on daily family life.Results  Two themes representing this distinction between internal and external family challenges are presented in detail. Across both younger adolescent (aged 10–14 years) and older adolescent (aged 16–20 years) groups, families were first challenged by changing family roles and relationships (an internal factor). In response, families used three strategies: dividing up family time, protecting some members from too much involvement and engaging others in family activities. Families were also challenged by service discontinuity (an external factor). Accommodation strategies included advocacy, coordinating multiple services and forfeiting a desired alternative.Conclusions  Family routine in the adolescent years is dynamic rather than static, simultaneously challenged by internal and external factors. Families use multiple strategies to accommodate these challenges, which are underpinned by their beliefs, values and resources. Professionals working with families caring for an adolescent with disability need to be aware of these in order to support families effectively to sustain a meaningful family routine during the adolescent years.
Well‐being, involvement in paid work and division of child‐care in parents of children with intellectual disabilities in Sweden
Authors: Olsson M. B. , Hwang C. P. 
Published: November 2006

AbstractBackground  The aim of the study was to compare mothers’ and fathers’ involvement in paid work and child‐care in families of children with intellectual disability (ID) and control families and to test if differences in well‐being between mothers and fathers of children with ID can be explained by differences in involvement in paid work and child‐care.Methods  Mothers and fathers of 179 children with ID and 196 typically developing children answered mailed surveys on their involvement in paid work, child‐care tasks and well‐being. Only two‐parent families were included.Results  The results show main effects for gender of the parent and presence of a child with ID on involvement in paid work and well‐being. Interaction effects indicate that mothers of children with ID are more affected than fathers in their participation in paid work and well‐being. A positive relation between level of participation in paid work and well‐being was found for both mothers and fathers. No difference in division of child‐care tasks was found between families of children with ID and control families. Differences in involvement in paid work and child‐care in families of children with ID only explained 5% of the variance in the difference between mothers’ and fathers’ well‐being.Conclusions  Families with children with ID differ from control families in that the parents are less involved in paid work and have lower levels of well‐being. A positive relation between involvement in paid work and well‐being was found.