bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrologic Connectivity Affects Fish Assemblage Structure, Diversity, and Ecological Traits in the Unregulated Gambia River, West Africa
Authors: White Seth M. , Ondračková Markéta , Reichard Martin 
Published: December 2011

AbstractThe Gambia River of West Africa is a large unobstructed river, characterized by a natural flow regime and lateral connectivity across its floodplain. Construction of a major dam, however, is planned. We compared patterns of fish diversity, habitat use, assemblage structure, and the distribution of trophic position and body morphology in riverine and floodplain habitats in Niokolo Koba National Park, located downstream of the planned dam site. A total of 49 fish species were captured, revealing a lognormal distribution as expected for species‐rich assemblages. Fish species exhibited a range of habitat use patterns, from generalist to highly habitat‐specific, and appeared to migrate laterally among habitats between seasons. Species richness was homogenous among habitats in the wet season yet appeared to increase with isolation from the main river in the dry season. Fish assemblage structure was best explained by the interaction between habitat type and season, underlining the importance of the natural flow regime and lateral connectivity among floodplain habitats. The abundance of fishes having elongate bodies increased with isolation from the main channel in the wet season only. The distribution of fishes having compressed cross‐sectional morphology decreased with isolation from the main channel in the dry season only. These patterns of trait distribution support the conclusion that variation in hydrologic connectivity structures the fish assemblage. Our results suggest that altered flow regimes and loss of floodplain habitats after damming could lead to both decreased taxonomic and functional diversity of the fish assemblage.
The association between childhood overweight and obesity and otitis media
Authors: Kuhle S. , Kirk S. F. L. , Ohinmaa A. , Urschitz M. S. , Veugelers P. J. 
Published: December 2011

SummaryObjectiveThe objective of this study was to examine the association between otitis media and childhood obesity in a population‐based sample of elementary school children in the Canadian province of Nova Scotia.MethodsThe study design is a prospective cohort study, linking data from a population‐based survey of Grade 5 students (aged 10–11 years) in the Canadian province of Nova Scotia in 2003 with Nova Scotia administrative health data. Measured body mass index was used to define weight status based on the age‐ and gender‐specific cut‐off points of the International Obesity Task Force. Health administration data for each child was linked via Health Card numbers. The primary outcome was healthcare utilization (physician visits and costs) for suppurative otitis media (International Classification of Diseases [ICD]9: 382; ICD10: H65–66) with no previous diagnosis of otitis in the last 30 days.ResultsRelative to normal weight children, obese children had more healthcare provider contacts for otitis media (adjusted incidence rate ratio 2.03, 95% confidence interval [CI] 1.66–2.49), incurred more costs per otitis media‐related visit ($47 vs. $24,
P
= 0.0001) and had higher odds to have repeated otitis media (adjusted odds ratio 2.27, 95% CI 1.54–3.35). Socioeconomic factors, a history of breastfeeding, presence of an allergic disorder or chronic adenoid/tonsil disorder did not change the association between obesity and otitis media.ConclusionThere is a clear association between childhood obesity and otitis media that cannot be explained by confounding by socioeconomic factors or clinically associated disorders.
Dengue Virus Capsid Protein Binding to Hepatic Lipid Droplets (LD) Is Potassium Ion Dependent and Is Mediated by LD Surface Proteins
Authors: Carvalho Filomena A. , Carneiro Fabiana A. , Martins Ivo C. , Assunção-Miranda Iranaia , Faustino André F. , Pereira Renata M. , Bozza Patricia T. , Castanho Miguel A. R. B. , Mohana-Borges Ronaldo , Da Poian Andrea T. , Santos Nuno C. 
Published: December 2011

ABSTRACT

Dengue virus (DENV) affects millions of people, causing more than 20,000 deaths annually. No effective treatment for the disease caused by DENV infection is currently available, partially due to the lack of knowledge on the basic aspects of the viral life cycle, including the molecular basis of the interaction between viral components and cellular compartments. Here, we characterized the properties of the interaction between the DENV capsid (C) protein and hepatic lipid droplets (LDs), which was recently shown to be essential for the virus replication cycle. Zeta potential analysis revealed a negative surface charge of LDs, with an average surface charge of −19 mV. The titration of LDs with C protein led to an increase of the surface charge, which reached a plateau at +13.7 mV, suggesting that the viral protein-LD interaction exposes the protein cationic surface to the aqueous environment. Atomic force microscopy (AFM)-based force spectroscopy measurements were performed by using C protein-functionalized AFM tips. The C protein-LD interaction was found to be strong, with a single (un)binding force of 33.6 pN. This binding was dependent on high intracellular concentrations of potassium ions but not sodium. The inhibition of Na
+
/K
+
-ATPase in DENV-infected cells resulted in the dissociation of C protein from LDs and a 50-fold inhibition of infectious virus production but not of RNA replication, indicating a biological relevance for the potassium-dependent interaction. Limited proteolysis of the LD surface impaired the C protein-LD interaction, and force measurements in the presence of specific antibodies indicated that perilipin 3 (TIP47) is the major DENV C protein ligand on the surface of LDs.
The effect of sports specialization on musculus quadriceps function after exercise-induced muscle damage
Authors: Skurvydas Albertas , Brazaitis Marius , Venckūnas Tomas , Kamandulis Sigitas , Stanislovaitis Aleksas , Zuoza Aurelijus 
Published: December 2011

The primary aim of the present study was to examine the effect of eccentric exercise-induced (100 submaximal eccentric contractions at an angular velocity of 60° s–1, with 20-s rest intervals) muscle damage on peripheral and central fatigue of quadriceps muscle in well-trained long-distance runners, sprint runners, volleyball players, and untrained subjects. We found that (i) indirect symptoms of exercise-induced muscle damage (prolonged decrease in maximal voluntary contraction, isokinetic concentric torque, and electrically induced (20 Hz) torque) were most evident in untrained subjects, while there were no significant differences in changes of muscle soreness and plasma creatine kinase 48 h after eccentric exercise between athletes and untrained subjects; (ii) low-frequency fatigue was greater in untrained subjects and volleyball players than in sprint runners and long-distance runners; (iii) in all subjects, electrically induced (100 Hz) torque decreased significantly by about 20%, while central activation ratio decreased significantly by about 8% in untrained subjects and sprint runners, and by about 3%–5% in long-distance runners and volleyball players. Thus, trained subjects showed greater resistance to exercise-induced muscle damage for most markers, and long-distance runners had no advantage over sprint runners or volleyball players.
A randomised crossover placebo-controlled trial investigating the effect of brown seaweed (Ascophyllum nodosum and Fucus vesiculosus) on postchallenge plasma glucose and insulin levels in men and women
Authors: Paradis Marie-Eve , Couture Patrick , Lamarche Benoît 
Published: December 2011

This study examined the impact of brown seaweed on post-load plasma glucose and insulin concentrations in men and women. Twenty-three participants (11 men, 12 women) aged 19–59 years were recruited in this double-blind, randomized, placebo-controlled crossover study. The test product consisted of a commercially available blend of brown seaweed (Ascophyllum nodosum and Fucus vesiculosus) with known inhibitory action on α-amylase and α-glucosidase activities (InSea2). Two 250 mg seaweed capsules and 2 placebo capsules were consumed on each occasion 30 min prior to the consumption of 50 g of carbohydrates from bread. Plasma glucose and insulin concentrations were measured over a period of 3 h postcarbohydrate ingestion at predetermined time points. Both treatments were separated by a 1-week washout period. Data were analysed using mixed models for repeated measures. Compared with placebo, consumption of seaweed was associated with a 12.1% reduction in the insulin incremental area under the curve (p = 0.04, adjusted for baseline) and a 7.9% increase in the Cederholm index of insulin sensitivity (p < 0.05). The single ingestion of 500 mg of brown seaweed had no significant effect on the glucose response (p = 0.24, adjusted for baseline). Glucose and insulin responses were similar between men and women. Consumption of the seaweed capsules was not associated with any adverse event. These data suggest that brown seaweed may alter the insulin homeostasis in response to carbohydrate ingestion.
Energy intake and appetite-related hormones following acute aerobic and resistance exercise
Authors: Balaguera-Cortes Liliana , Wallman Karen E. , Fairchild Timothy J. , Guelfi Kym J. 
Published: December 2011

Previous research has shown that resistance and aerobic exercise have differing effects on perceived hunger and circulating levels of appetite-related hormones. However, the effect of resistance and aerobic exercise on actual energy intake has never been compared. This study investigated the effect of an acute bout of resistance exercise, compared with aerobic exercise, on subsequent energy intake and appetite-regulating hormones. Ten active men completed 3 trials in a counterbalanced design: 45 min of resistance exercise (RES; free and machine weights), aerobic exercise (AER; running), or a resting control trial (CON). Following exercise or CON, participants had access to a buffet-style array of breakfast foods and drinks to consume ad libitum. Plasma concentrations of a range of appetite-regulating hormones were measured throughout each trial. Despite significantly higher energy expenditure with AER compared with RES (p < 0.05), there was no difference in total energy intake from the postexercise meal between trials (p = 0.779). Pancreatic polypeptide was significantly higher prior to the meal after both RES and AER compared with CON. In contrast, active ghrelin was lower following RES compared with both CON and AER (p ≤ 0.05), while insulin was higher following RES compared with CON (p = 0.013). In summary, the differential response of appetite-regulating hormones to AER and RES does not appear to influence energy intake in the postexercise meal. However, given the greater energy expenditure associated with AER compared with RES, AER modes of exercise may be preferable for achieving short-term negative energy balance.
Chapter 10 Modelling the Snowball Earth
Authors: Goddéris Yves , Le Hir Guillaume , Donnadieu Yannick 
Published: December 2011

Abstract

We review most of the modelling studies performed to date to understand the initiation and melting of a Snowball Earth, as well as to describe the glacial environment during the glaciation itself. All the described scenarios explaining the onset of glaciation rely on a sufficient decrease in the concentrations of atmospheric greenhouse gases (GHGs), typically resulting from the equatorial palaeogeography of the late Proterozoic. It is still heavily debated whether or not the oceanic ice cover was thick during the glaciation itself. However, a consensus has arisen that the most climatically stable scenarios imply the existence of a globally frozen ocean, with a thick ice cover caused by the flowing of high-latitude sea-ice glaciers towards the equator. Depending on the characteristics of the ice, a thin ice layer may have persisted along the equator, but this numerical solution is rather fragile. During the snowball event itself, model results suggest the existence of wet-based continental glaciers. Some parts of the continents may have remained ice-free. From the modelling perspective, the most significant problem in the snowball hypothesis, particularly in its ‘hard snowball’ version (the most stable numerically), is the melting phase. With improved modelling, the CO
2
threshold required to melt the snowball is much higher than initially thought, significantly above 0.29 bar. Indeed, because of the very cold conditions prevailing at the surface of the Earth during the glacial event, the atmosphere becomes vertically isothermal, strongly limiting the efficiency of the greenhouse effect. This melting problem is further highlighted by geochemical modelling studies that show that weathering of the oceanic crust might be an active sink of CO
2
during the glacial event, limiting the rise in atmospheric CO
2
. The solution might be found by considering the input of dark dust from catastrophic volcanic eruptions that would efficiently decrease the albedo of the ice. Finally, modelling studies also explore the aftermath of the glaciation. The world might have been drier than initially anticipated, resulting in the persistence of the supergreenhouse effect for at least one million years after the melting phase.
Chapter 18 The Karoetjes Kop and Bloupoort formations, Gifberg Group, South Africa
Authors: Frimmel Hartwig E. 
Published: December 2011

Abstract

The Vredendal Outlier near the South African west coast lies in an intermediate position between the late Neoproterozoic Gariep Belt further north and the Cambrian Saldania Belt further south. It consists of a sedimentary succession of siliciclastic and carbonate rocks, unified as the Gifberg Group, which contains two diamictite-bearing units, the Karoetjes Kop Formation at the base and the Bloupoort Formation near the top of the group. The diamictite of the Karoetjes Kop Formation represents mainly debris flow deposits in a continental rift setting, with some contribution from retreating glaciers. In contrast, the younger diamticite in the Bloupoort Formation is glaciomarine, is associated with banded iron-formation, is underlain by stromatolitic reef carbonates and is overlain by carbonates. Most of the Gifberg Group is poorly exposed and poorly investigated. In the absence of radiometric age data, stratigraphic interpretation and correlation is based on lithological and chemostratigraphic evidence. The entire Gifberg Group is considered to be equivalent to the much better investigated Port Nolloth Group in the Gariep Belt (
sensu stricto
). Whereas the Karoetjes Kop Formation is correlated with the
c.
750 Ma Kaigas Formation of the Gariep Belt, the diamictite and associated banded iron-formation of the Bloupoort Formation are regarded as correlatives of the Numees Formation of the Gariep Belt. The entire Gifberg Group was subjected to transpressional deformation and accompanying low-grade metamorphism during continental collision between the Rio de la Plata and Kalahari plates at the end of the Neoproterozoic and again during the Cambrian accretionary orogeny along the southwestern margin of Gondwana, which led to the development of the Saldania Belt further south.
Chapter 34 The Hula Hula Diamictite and Katakturuk Dolomite, Arctic Alaska
Authors: Macdonald Francis A. 
Published: December 2011

Abstract

The Katakturuk Dolomite is a
c.
2-km-thick Neoproterozoic carbonate succession (units K1–K4) exposed in the NE Brooks Range of Alaska. These strata were deposited on a south-facing (present coordinates), rifted passive margin on the North Slope subterrane (NSST) of the Arctic Alaska-Chukotka Plate (AACP). The glaciogenic Hula Hula diamictite rests below the Katakturuk Dolomite and consists of 2–50 m of diamictite that interfingers with the underlying Mt. Copleston volcanic rocks. Unit K1 of the Katakturuk Dolomite begins with less than 10 m of dark grey, finely laminated limestone with ‘roll-up’ structures, and continues upwards with nearly 500 m of recrystallized, ooid-dominated grainstone. The Nularvik dolomite (unit K2 of the Kataktruk Dolomite) rests on unit K1 with a knife-sharp contact on a heavily silicified surface. The Nularvik dolomite is composed predominantly of laminated micro-peloids hosting tubestone stromatolites and giant wave ripples, followed by decametres of dolomatized, pseudomorphosed former aragonite crystal fans.

Carbon-isotope chemostratigraphy suggests that the Hula Hula diamictite is an early Cryogenian glacial deposit, and that, despite the absence of directly underlying glacial deposits, the Nularvik dolomite is a basal Ediacaran cap carbonate. These correlations are supported by the characteristic sedimentological features in both the carbonate capping the Hula Hula diamictite and the Nularvik dolomite. Detrital zircon and Palaeozoic fauna provenance studies support the inference that much of the AACP is exotic to Laurentia; however, the pre-Mississipian relationship between the NSST and the rest of the AACP remains uncertain. Previous palaeomagnetic surveys have been hampered by pervasive Late Cretaceous overprints. Additional geological mapping, sequence stratigraphy and geochronological data are needed to correlate Neoproterozoic and Palaeozoic units across the AACP, and constrain relationships between subterranes in the AACP.
Chapter 35 The Tatonduk inlier, Alaska–Yukon border
Authors: Macdonald Francis A. , Cohen Phoebe A. 
Published: December 2011

Abstract

Glaciogenic deposits of the Rapitan and Hay Creek Groups are exposed in the Tatonduk inlier of east-central Alaska and the western Yukon. The Rapitan Group ranges in thickness from
c.
50 to 700 m with Fe-formation common in the upper 10 m. In the most distal settings, the Rapitan Group is separated from the diamictite of the Hay Creek Group by over 100 m of sandstone and siltstone; however, the Hay Creek Group contains large erosive surfaces and cannibalizing breccia, and rarely preserves strata between the two glaciogenic deposits. The diamictite of the Hay Creek Group is capped by a white- to buff-coloured dolostone with pseudo-teepee structures, bed-parallel, isopachous sheet-crack cements, and a depleted C-isotope signature. Late Neoproterozoic glacial deposits in the Tatonduk inlier were formerly assigned to the Tindir Group. To simplify the nomenclature in the northwestern Canadian Cordillera, the Tindir Group was abandoned and replaced with nomenclature consistent with that of the Windermere Supergroup in the Mackenzie Mountains. The mixed lithology and anchizone-grade metamorphism distinguish the Rapitan and Hay Creek Groups in the Tatonduk inlier as attractive future targets for integrated micropalaeontology, geochemistry, palaeomagnetism and geochronology.
Chapter 37 The record of Neoproterozoic glaciations in the Windermere Supergroup, southern Canadian Cordillera
Authors: Smith Mark D. , Arnaud Emmanuelle , Arnott R.W.C. , Ross Gerald M. 
Published: December 2011

Abstract

The Neoproterozoic Windermere Supergroup (WSG) is exposed over an area of 35 000 km
2
in the southern Canadian Cordillera, and consists primarily of deep-marine meta-sedimentary rocks interpreted to have been deposited during rifting and subsequent post-rift thermal relaxation. The main exposures of the WSG occur within thrust panels and structural culminations of the eastern Cordilleran orogen. Within the thick stratigraphic succession (
c.
9 km) are three units of glaciogenic affinity: Toby, Vreeland and Old Fort Point (OFP) formations. The Toby Formation (Fm.) is composed of up to 2500 m of diamictite, interbedded with conglomerate, sandstone, mudstone, carbonate and mafic volcanic rocks. The Vreeland Formation ranges from 350 m to 2000 m in thickness and consists of diamictite, interbedded with mudstone, sandstone and conglomerate. The OFP ranges from 60 to 450 m in thickness and consists of a distinctive threefold stratigraphic package of basal siltstone grading upward into limestone–siltstone rhythmite, organic-rich mudstone and an overlying heterolithic unit of diamictite, breccia, conglomerate, sandstone, siltstone to mudstone and limestone. A locally prominent unconformity marks the base of the OFP upper member. Both the Toby and Vreeland formations represent remobilized glacially derived marine sediments deposited by sediment-gravity flows. Deposition of the Toby Fm. was fault-controlled during an active tectonic phase (rifting), whereas the Vreeland Fm. accumulated during the subsequent quiescent phase (post-rift) with limited structural control. The OFP is interpreted to be a regionally extensive deep-marine post-glacial marker temporally associated with the glaciogenic Vreeland Fm. Although direct geochronological ages for WSG units in southwestern Canada are generally absent, high-precision radiometric ages of underlying and overlying igneous events constrain the relative maximum and minimum timing of deposition from
c.
740–728 Ma to
c.
569 Ma. At the base of the WSG succession, the Toby Fm. may be as young as
c.
685 Ma based on ages obtained from potential stratigraphic correlatives in the USA. There is no direct age constraint for the deposition of the Vreeland Fm.; its minimum timing is based on its stratigraphic relationship with the post-glacial OFP. The middle member of the OFP was precisely dated at 607.8±4.7 Ma using the Re–Os method, placing it in the Ediacaran Period. Published geochemical and stable isotopic data are similarly limited for all three units with only some δ
34
S
py
values available from one section of the OFP. Recent work has focused on detailed sedimentological and stratigraphic studies of the Toby and OFP formations with future efforts being directed towards integrated geochemical and isotopic research. Additional geochronological constraints are needed to refine palaeogeographical models and strengthen regional correlations with other North American Cordilleran glaciogenic units.