bluuebunny/crossref_metadata_2025_split huggingface dataset:
Automated morphometric magnetic resonance imaging analysis for the detection of periventricular nodular heterotopia
Authors: Pascher Bettina , Kröll Judith , Mothersill Ian , Krämer Günter , Huppertz Hans‐Jürgen 
Published: January 2013

SummaryPurpose:  To describe a novel magnetic resonance imaging (MRI) postprocessing technique for the detection of periventricular nodular heterotopia (PNH) and to evaluate its diagnostic value. The method is a further development of voxel‐based morphometric analysis with focus on a region of interest around the lateral ventricles to increase the sensitivity and specificity for automated detection of abnormally located gray matter in this area.Methods:  T1‐weighted MRI volume data sets were normalized and segmented in statistical parametric mapping (SPM 5 software), and the distribution of gray matter was compared to a normal database. As a new approach, individual masks derived from segmentation of the lateral ventricles were used to restrict the search for ectopic gray matter to the periventricular area. PNH were automatically detected by localizing the maximum deviation from the normal database in this area, provided that the z‐score exceeded a certain threshold. The optimal z‐score threshold for maximum sensitivity and specificity was determined by a receiver operating characteristic (ROC) curve analysis. The method was applied in 40 patients with PNH and 400 controls.Key Findings:  PNH were detected in 37 of 40 patients, and false positives were found in 34 of 400 controls, amounting to 92.5% sensitivity and 91.5% specificity. In 17 of the patients in whom PNH could be identified, these lesions had been overlooked in the past, and in 8 patients even in the high‐resolution MRI subsequently used for postprocessing.Significance:  The results suggest that automated morphometric MRI analysis with focus on ectopic gray matter in the periventricular areas facilitates the evaluation of MRI data and increases the sensitivity for the detection of PNH.
How much do fish aggregating devices (FADs) modify the floating object environment in the ocean?
Authors: Dagorn Laurent , Bez Nicolas , Fauvel Thomas , Walker Emily 
Published: January 2013

AbstractNatural floating objects (e.g., logs) have always been a component of the habitat of tropical tunas. However, the introduction of fish aggregating devices (FADs) modifies this environment. To assess the changes due to the deployment of FADs, we compared the spatial distribution of natural and artificial floating objects (FADs), using data from observers onboard tuna purse seine vessels in the Indian Ocean from December 2006 to December 2008. Although natural objects occur more commonly in waters south of 7°S and FADs are more common in waters north of 7°S, all types of floating objects can be found everywhere. Using different spatial scales (quadrats of size 1° × 1°, 2° × 2°, 5° × 5°, and 10° × 10°), we computed the proportion of FADs observed in quadrats without natural objects. The scale of 2° × 2° quadrats represented a threshold: distributions of the two types of objects were different at scales smaller than this threshold. The strongest change that has occurred since the introduction of FADs (besides the increased catches) has been the dramatic increase in the total number of floating objects. Since the introduction of FADs, the number of objects has at least doubled everywhere (except in the Mozambique Channel and Chagos) and in some areas (e.g., Somalia area) the multiplication factor has reached as high as 20 or 40. Our study sets the ranges of values of key parameters of the floating object environment, which are crucial in the design of future experimental studies aimed at investigating the impacts of FADs on the ecology of tunas.
The potential trade‐off between artisanal fisheries production and hydroelectricity generation on the Kafue River, Zambia
Authors: DEINES ANDREW M. , ADAM BEE C. , Katongo Cyprian , JENSEN RICHARD , LODGE DAVID M. 
Published: January 2013

Summary1. Freshwater resource managers are increasingly obligated to consider the impacts of large river engineering projects on ecosystem services. We evaluated the effect of altered water regime from the operation of a large dam on the production of the downstream tropical floodplain fishery of the Kafue River, Zambia. We compared the benefits of increased hydropower relative to potentially lost fishery production.2. We compiled a long‐term data set consisting of experimental gillnet catches, artisanal harvesting effort and monthly river flows for 25 years prior to and 29 years after the 1977 completion of the upstream Itezhi‐Tezhi Dam. As a metric of the flood regime, we calculated a canonical correlation score for each hydrological year before and after dam closure. For the period following dam construction, we used the Muskingum method of flood routing to estimate ‘no‐dam’ flows through the fishery area and downstream hydroelectric turbines at the Kafue Gorge Dam.3. We compared 16 alternative models of catch per unit effort (CPUE) with and without an effect of water regime on fish population growth rate. Using the two best fitting models, we estimated the total observed fishery harvest and simulated ‘no‐dam’ fisheries harvest and found no significant effect of altered water regime on fishery production.4. We estimate that the large upstream dam increases downstream hydropower production by about $18 million USD per annum. The reduction in fishery production caused by the altered water regime is not significantly different than zero, although the average reduction amounts to about $2.3 million annually. The total estimated value of harvest ranges from $1.3 million to $56 million annually.5. Large observed declines in fish abundance over the 54‐year study period are attributed primarily with similarly large increases in total fishing effort in this mostly open‐access artisanal fishery.6. These results contrast with other examples of the effects of flow alteration on fish, probably because levels of fisheries exploitation on the Kafue River are very high relative to better studied regions on other continents; our focus on the whole fish community; and the unprecedented length of the time series we considered. If the goal is to sustain fishery production, investments in altering flow regime are likely to be less effective than investments to decrease fishing effort.
Organic enrichment of sediments reduces arbuscular mycorrhizal fungi in oligotrophic lake plants
Authors: MØLLER CLAUS L. , KJØLLER RASMUS , SAND‐JENSEN KAJ 
Published: January 2013

Summary1. Arbuscular mycorrhizal fungi (AMF) commonly colonise isoetid species inhabiting oxygenated sediments in oligotrophic lakes but are usually absent in other submerged plants. We hypothesised that organic enrichment of oligotrophic lake sediments reduces AMF colonisation and hyphal growth because of sediment O2 depletion and low carbon supply from stressed host plants.2. We added organic matter to sediments inhabited by isoetids and measured pore‐water chemistry (dissolved O2, inorganic carbon, Fe2+ and ), colonisation intensity of roots and hyphal density after 135 days of exposure.3. Addition of organic matter reduced AMF colonisation of roots of both Lobelia dortmanna and Littorella uniflora, and high additions stressed the plants. Even small additions of organic matter almost stopped AMF colonisation of initially un‐colonised L. uniflora, though without reducing plant growth. Mean hyphal density in sediments was high (6 and 15 m cm−3) and comparable with that in terrestrial soils (2–40 m cm−3). Hyphal density was low in the upper 1 cm of isoetid sediments, high in the main root zone between 1 and 8 cm and positively related to root density. Hyphal surface area exceeded root surface area by 1.7–3.2 times.4. We conclude that AMF efficiently colonise isoetids in oligotrophic sediments and form extensive hyphal networks. Small additions of organic matter to sediments induce sediment anoxia and reduce AMF colonisation of roots but cause no apparent plant stress. High organic addition induces night‐time anoxia in both the sediment and the plant tissue. Tissue anoxia reduces root growth and AMF colonisation, probably because of restricted translocation of nutrient ions and organic solutes between roots and leaves. Isoetids should rely on AMF for P uptake on nutrient‐poor mineral sediments but are capable of growing without AMF on organic sediments.
Stocked trout have minimal effects on littoral invertebrate assemblages of productive fish‐bearing lakes: a whole‐lake BACI study
Authors: HANISCH JUSTIN R. , TONN WILLIAM M. , PASZKOSWKI CYNTHIA A. , SCRIMGEOUR GARRY J. 
Published: January 2013

Summary1. Rainbow Trout (Oncorhynchus mykiss [Walbaum]) is commonly stocked as a sport fish throughout the world but can have serious negative effects on native species, especially in headwater systems. Productive fish‐bearing lakes represent a frequently stocked yet infrequently studied system, and effects of trout in these systems may differ from those in headwater lakes.2. We used a Before‐After Control‐Impact (BACI) design to determine how stocked trout affected assemblage‐level and taxon‐level biomass, abundance and average length of littoral invertebrates in a stocked lake relative to three unstocked control lakes in the boreal foothills of Alberta, Canada. Lakes were studied 1 year before and for 2 years after stocking. Because characteristics of productive fish‐bearing lakes should buffer impacts of introduced fish, we predicted that trout would not affect assemblage‐level structure of littoral invertebrates but might reduce the abundance or average length of large‐bodied taxa frequently consumed by trout.3. Relative to the unstocked control lakes, biomass, but not abundance, of the littoral invertebrate assemblage was affected indirectly by trout through increases of some taxa after trout stocking. At the individual taxon‐level, trout stocking did not affect most (23 of the 27) taxa, with four taxa increasing in abundance or biomass after stocking. Only one taxon, Chironomidae, showed evidence of size‐selective predation by trout, being consumed frequently by trout and decreasing significantly in average length after stocking.4. Our results contrast with the strong negative effects of trout stocking on invertebrate assemblages commonly reported from headwater lakes. A combination of factors, including large and robust native populations of forage fish, the generalised diet of trout, overwinter aeration, relatively high productivity and dense macrophyte beds, likely works in concert to reduce potentially negative effects of stocked trout in these systems. As such, productive, fish‐bearing lakes may represent a suitable system for trout stocking, especially where native sport fish populations are lacking.
Did life originate from a global chemical reactor?
Authors: Stüeken E. E. , Anderson R. E. , Bowman J. S. , Brazelton W. J. , Colangelo‐Lillis J. , Goldman A. D. , Som S. M. , Baross J. A. 
Published: January 2013

AbstractMany decades of experimental and theoretical research on the origin of life have yielded important discoveries regarding the chemical and physical conditions under which organic compounds can be synthesized and polymerized. However, such conditions often seem mutually exclusive, because they are rarely encountered in a single environmental setting. As such, no convincing models explain how living cells formed from abiotic constituents. Here, we propose a new approach that considers the origin of life within the global context of the Hadean Earth. We review previous ideas and synthesize them in four central hypotheses: (i) Multiple microenvironments contributed to the building blocks of life, and these niches were not necessarily inhabitable by the first organisms; (ii) Mineral catalysts were the backbone of prebiotic reaction networks that led to modern metabolism; (iii) Multiple local and global transport processes were essential for linking reactions occurring in separate locations; (iv) Global diversity and local selection of reactants and products provided mechanisms for the generation of most of the diverse building blocks necessary for life. We conclude that no single environmental setting can offer enough chemical and physical diversity for life to originate. Instead, any plausible model for the origin of life must acknowledge the geological complexity and diversity of the Hadean Earth. Future research may therefore benefit from identifying further linkages between organic precursors, minerals, and fluids in various environmental contexts.
Markers of microbial translocation predict hypertension in HIV‐infected individuals
Authors: Manner IW , Baekken M , Kvale D , Oektedalen O , Pedersen M , Nielsen SD , Nowak P , Os I , Trøseid M 
Published: January 2013

ObjectivesThe aim of the study was to test the hypothesis that microbial translocation, quantified by levels of lipopolysaccharide (LPS) and subsequent monocyte activation [soluble (sCD14)], is associated with hypertension in HIV‐infected individuals.MethodsIn this exploratory substudy, 42 patients were recruited from a larger, longitudinal HIV‐infected cohort study on blood pressure. LPS and sCD14 levels were measured retrospectively at the time of nadir CD4 cell count, selecting untreated HIV‐infected patients with both advanced immunodeficiency and preserved immunocompetence at the time of nadir. Patients with later sustained hypertension (n = 16) or normotension (n = 26) throughout the study were identified. LPS was analysed using the Limulus Amebocyte Lysate colorimetric assay (Lonza, Walkersville, MD) and sCD14 using an enzyme‐linked immunosorbent assay (ELISA). Nonparametric statistical tests were applied.ResultsIn the HIV‐infected patients [median (interquartile range) age 42 (32–46) years; 79% male and 81% Caucasian], LPS and sCD14 levels were both negatively correlated with nadir CD4 cell count. Plasma levels of LPS (P < 0.001) and sCD14 (P = 0.024) were elevated in patients with later hypertension compared with patients with normotension. There was a stepwise increase in the number of patients with hypertension across tertiles of LPS (P = 0.001) and sCD14 (P = 0.007). Both LPS and sCD14 were independent predictors of elevated blood pressure after adjustment for age and gender. For each 10‐unit increase in LPS (range 66–272 pg/ml), the increment in mean blood pressure in the first period of blood pressure recording was 0.86 (95% confidence interval 0.31–1.41) mmHg (P = 0.003).ConclusionsAs LPS and sCD14 were both independently associated with elevated blood pressure, microbial translocation may be linked to the development of hypertension.
Do Finnish home economics and health education textbooks promote constructivist learning in nutrition education?
Authors: Hokkanen Säde , Kosonen Anna‐Liisa 
Published: January 2013

AbstractIn Finnish secondary schools, nutrition education is integrated mainly in home economics and health education lessons. The aim of this research was to describe the content and pedagogical style in food‐ and nutrition‐related texts in secondary school textbooks. Textbooks are important learning tools in education in so far as they reflect current pedagogical thinking and the objectives set in the national core curriculum. The study data consisted commonly used home economics (n = 4) and health education (n = 3) textbooks. Nutrition contents of the textbooks were compatible with the national core curriculum. The scope of nutrition education in health education textbooks was health centred, whereas home economics textbooks considered also cultural and environmental aspects of nutrition education. All textbooks considered adolescents' current nutrition issues. The pedagogical style was usually participative in exercises and neutral informative in a plain text; however, a considerable amount of text was written on using a persuasive style. Overall, textbook pedagogical style supported the constructivist idea of learning, and textbooks can be a positive agent for change as we strive towards a better nutrition health in children and adolescents.
Does preserved kidney volume predict 1 year donor renal function after laparoscopic living donor nephrectomy?
Authors: Yakoubi Rachid , Autorino Riccardo , Kassab Ahmad , Long Jean Alexandre , Haber Georges‐Pascal , Kaouk Jihad H 
Published: January 2013

AbstractThe aim of the present study was to evaluate whether preserved kidney volume predicts donor renal function at 1‐year post‐surgery. Data of patients who underwent laparoscopic living donor nephrectomy between October 2006 and September 2010 were retrospectively reviewed. All patients underwent computed tomography scan with an estimation of kidney volume by using an automated segmentation algorithm. We also calculated kidney volume adjusted for donor body surface area and donor preserved kidney volume ratio (split volume). Estimated glomerular filtration rate was estimated using the Modification of Diet in Renal Disease equation. Predictors of the estimated glomerular filtration rate at 1 year were assessed by multiple linear regression. The 1‐year estimated glomerular filtration rate was available in 140 patients. The median age was 40 years, and median adjusted preserved kidney volume was 160.5 cc/1.73 m2 (interquartile range 143.7–177.9). Median estimated glomerular filtration rate was 92.4 (interquartile range 81.9–101.2) and 61.2 mL/min/1.73 m2 (interquartile range 53.4–68.7), respectively, at baseline and at 1 year. Preserved kidney volume adjusted to body surface area (P = 0.02) with age (P = 0.002) and preoperative estimated glomerular filtration rate (P < 0.001) were independent predictors of estimated glomerular filtration rate at 1 year. However, split kidney volume was not statistically related to estimated glomerular filtration rate at 1 year (P = 0.47). In order to maximize preservation of donor renal function, the pre‐donation kidney volume adjusted to body surface area might be a useful parameter to consider when deciding on living kidney donation.
Variable induction of vitellogenin genes in the varroa mite, Varroa destructor (Anderson & Trueman), by the honeybee, Apis mellifera L, host and its environment
Authors: Cabrera Cordon A. R. , Shirk P. D. , Duehl A. J. , Evans J. D. , Teal P. E. A. 
Published: January 2013

AbstractTranscript levels of vitellogenins (Vgs) in the varroa mite, Varroa destructor (Anderson & Trueman), were variably induced by interactions between the developing honeybee, Apis mellifera L, as a food source and the capped honeybee cell environment. Transcripts for two Vgs of varroa mites were sequenced and putative Vg protein products characterized. Sequence analysis of VdVg1 and VdVg2 proteins showed that each had greater similarity with Vg1 and Vg2 proteins from ticks, respectively, than between themselves and were grouped separately by phylogenetic analyses. This suggests there was a duplication of the ancestral acarine Vg gene prior to the divergence of the mites and ticks. Low levels of transcript were detected in immature mites, males and phoretic females. Following cell invasion by phoretic females, VdVg1 and VdVg2 transcript levels were up‐regulated after cell capping to a maximum at the time of partial cocoon formation by the honeybee. During oviposition the two transcripts were differentially expressed with higher levels of VdVg2 being observed. A bioassay based on assessing the transcript levels was established. Increases in VdVg1 and VdVg2 transcripts were induced experimentally in phoretic females when they were placed inside a cell containing an early metamorphosing last instar bee but not when exposed to the metamorphosing bee alone. The variable response of Vg expression to the food source as well as environmental cues within the capped cell demonstrates that perturbation of host−parasite interactions may provide avenues to disrupt the reproductive cycle of the varroa mites and prevent varroasis.
Transgene‐mediated suppression of the RNA interference pathway in Aedes aegypti interferes with gene silencing and enhances Sindbis virus and dengue virus type 2 replication
Authors: Khoo C. C. H. , Doty J. B. , Heersink M. S. , Olson K. E. , Franz A. W. E. 
Published: January 2013

AbstractRNA interference (RNAi) is the major innate antiviral pathway in Aedes aegypti that responds to replicating arboviruses such as dengue virus (DENV) and Sindbis virus (SINV). On the one hand, the mosquito's RNAi machinery is capable of completely eliminating DENV2 from Ae. aegypti. On the other, transient silencing of key genes of the RNAi pathway increases replication of SINV and DENV2, allowing the viruses to temporally overcome dose‐dependent midgut infection and midgut escape barriers (MEB) more efficiently. Here we expressed Flock house virus B2 (FHV‐B2) from the poly‐ubiquitin (PUb) promoter in Ae. aegypti using the ΦC31 site‐directed recombination system to investigate the impact of transgene‐mediated RNAi pathway suppression on infections with SINV‐TR339eGFP and DENV2‐QR94, the latter of which has been shown to be confronted with a strong MEB in Ae. aegypti. FHV‐B2 was constitutively expressed in midguts of sugar‐ and blood‐fed mosquitoes of transgenic line PUbB2 P61. B2 over‐expression suppressed RNA silencing of carboxypeptidase A‐1 (AeCPA‐1) in midgut tissue of PUbB2 P61 mosquitoes. Following oral challenge with SINV‐TR339eGFP or DENV2‐QR94, mean titres in midguts of PUbB2 P61 females were significantly higher at 7 days post‐bloodmeal (pbm) than in those of nontransgenic control mosquitoes. At 14 days pbm, infection rates of carcasses were significantly increased in PubB2 P61 mosquitoes infected with SINV‐TR339eGFP. Following infection with DENV2‐QR94, midgut infection rates were significantly increased in the B2‐expressing mosquitoes at 14 days pbm. However, B2 expression in PUbB2 P61 did not increase the DENV2‐QR94 dissemination rate, indicating that the infection phenotype was not primarily controlled by RNAi.