bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors influencing the achievement of steady state in mercury contamination among lakes and catchments of south-central Ontario
Authors: Mills R. Brad , Paterson Andrew M. , Blais Jules M. , Lean David R.S. , Smol John P. , Mierle Greg 
Published: February 2009

Mercury (Hg) concentrations in recent (0.5–1 cm) and preindustrial (>30 cm) sediments were examined across lakes in south-central and eastern Ontario, Canada (45.53°N, 82.41°W to 44.15°N, 76.25°W), to determine whether Hg exported from watersheds is at steady state with atmospheric deposition. An examination of headwater lakes revealed that Hg enrichment was not uniform among watersheds but that the enrichment factor (EF = [Hg]present day/[Hg]preindustrial, standardized for organic matter) decreased as a function of drainage ratio (Ad /Ao, watershedarea/lakearea). Furthermore, the model fit was improved after accounting for differences in sulfate concentrations and pH among lakes: EF = (Ad /Ao)–15.96 – 0.07(SO 42– ) – (3.55(pH>8.3)) (R2 = 0.458, p = 0.0001). Hg concentrations in preindustrial sediments of headwater lakes showed a positive linear relationship with drainage ratio (partial t = 4.83, p < 0.0001, n = 66) that was strengthened following an adjustment for mean annual runoff (MAR) ([Hg]preindustrial = 0.011 ± 0.002(Ad /Ao) + 0.0008 ± 0.0003(MAR) (R2 = 0.108, F[1,66] = 8.01, p = 0.006)). Our results suggest that Hg export from watersheds may be currently lagging behind atmospheric Hg deposition, in which case, Hg export would increase into the future, even as Hg deposition from the atmosphere stabilizes.
Effects of sampling effort, assemblage similarity, and habitat heterogeneity on estimates of species richness and relative abundance of stream fishes
Authors: Fischer Jesse R. , Paukert Craig P. 
Published: February 2009

We estimated the sampling effort required to accurately estimate species richness and to detect changes in catch-per-unit-effort (CPUE) in four Great Plains, USA, streams. The number of sampled reaches (i.e., <1 km) required to estimate stream-segment (i.e., 20–28 km) species richness decreased with increased sampled reach length (i.e., 10, 20, 40, or 60 mean stream widths, MSW), whereas total sampling effort decreased with a greater number of shorter sampled reaches. Collecting all species in a stream segment required all sampled reaches (i.e., 10) of a length equal to 40 or 60 MSW. The number of stream reaches sampled with lengths equal to 40 MSW required to detect a 50% change in CPUE of common species (i.e., total abundance > 1% of total catch) with β = 0.80 ranged from 7 to 630 (mean = 99) and decreased with longer sampled reaches. A greater number of sampled reaches were needed to detect 90% of species richness and 25% changes in CPUE when Jaccard’s similarity of samples of stream fish assemblages and habitat heterogeneity was lower within streams. Our results suggest that homogeneous stream segments require more sampled reaches to characterize fish assemblages and monitor trends in fish abundance.
Biogenic calcite–phosphorus precipitation as a negative feedback to lake eutrophication
Authors: Hamilton Stephen K. , Bruesewitz Denise A. , Horst Geoffrey P. , Weed David B. , Sarnelle Orlando 
Published: February 2009

Lakes in carbonate-rich watersheds commonly precipitate calcium carbonate as calcite, and this is accelerated by photosynthetic uptake of carbon dioxide. Co-precipitation of phosphate with calcite is one reason that algal growth in such lakes tends to be strongly phosphorus (P) limited. The extent to which calcite precipitation can be a sink for added P, and thus act as a potential negative feedback to eutrophication, was demonstrated using large enclosures within a Michigan lake. Nitrogen and P were added over 45 days in the summer to produce mesotrophic and eutrophic conditions. Algal biomass and production increased markedly with the nutrient additions, elevating the pH (9–10) and greatly increasing calcite precipitation, reducing concentrations of calcium and alkalinity by up to 60%. Sediment traps indicated that calcite sedimentation was a major sink for added P. By the end of the experiment, only about half of the added P remained in the water column. Major ion concentrations in a larger set of Michigan lakes showed calcite precipitation to be widespread, reflecting the abundant carbonate minerals in this glacial region.
Reliability-based design of deep foundations based on differential settlement criterion
Authors: Roberts Lance A. , Misra Anil 
Published: February 2009

Load–displacement analysis of a single deep foundation element can be accomplished by utilizing a soil–structure interaction model, such as the “t–z” model. By combining the soil–structure interaction model with a probabilistic analysis technique, such as Monte Carlo simulation, methods to rationally incorporate variability in the model parameters can be developed. As a result, the service limit state load capacity of a single deep foundation element can be computed for an allowable total head displacement. However, in design, differential settlement between individual foundation elements is often the event of interest. This paper develops a reliability-based design methodology for deep foundations based on a differential settlement design criterion. The design methodology is developed for various levels of uncertainty in the model parameters. The results are presented in the form of cumulative distribution functions that, combined with the calculated service limit state load capacity, form the basis for serviceability design of deep foundations based on a differential settlement criterion.
The Transition to Strong Convection
Authors: Neelin J. David , Peters Ole , Hales Katrina 
Published: February 2009

AbstractRecent work has shown that observations of tropical precipitation conform to properties associated with critical phenomena in other systems. Here some of these universal properties are used to probe the physics of tropical convection empirically, providing potential tests for models and parameterizations. The power-law pickup of ensemble average precipitation as a function of column water vapor w occurs above a critical value wc whose temperature dependence is determined for layer-integrated tropospheric temperature or saturation value. This dependence differs from the simplest expectations based on column saturation. Rescaling w by wc permits a collapse of precipitation-related statistics to similar functional dependence for all temperatures. The sharp precipitation variance peak at wc, obtained without detailed vertical structure information, appears consistent with arguments that onset requires a deep moist layer. Sea surface temperature (SST) is found not to have a significant effect on the precipitation pickup. The effect of SST on the climatological precipitation occurs via the frequency of occurrence of w values as the system spends a larger fraction of time near criticality over regions of warm SST. Near and above criticality, where most precipitation occurs, the w distribution is highly constrained by the interaction with convection, with a characteristic sharp drop at criticality. For precipitating points, the distribution has a Gaussian core with an approximately exponential tail akin to forced advection–diffusion problems. The long tail above wc, implying relatively frequent strong events, remains similar through the range of tropospheric temperature and SST spanning tropical large-scale conditions. A simple empirical closure illustrates time decay properties.
Using Transformation and Formation Maps to Study the Role of Air–Sea Heat Fluxes in North Atlantic Eighteen Degree Water Formation
Authors: Maze Guillaume , Forget Gael , Buckley Martha , Marshall John , Cerovecki Ivana 
Published: February 2009

Abstract
The Walin water mass framework quantifies the rate at which water is transformed from one temperature class to another by air–sea heat fluxes (transformation). The divergence of the transformation rate yields the rate at which a given temperature range is created or destroyed by air–sea heat fluxes (formation). Walin’s framework provides a precise integral statement at the expense of losing spatial information. In this study the integrand of Walin’s expression to yield transformation and formation maps is plotted and used to study the role of air–sea heat fluxes in the cycle of formation–destruction of the 18° ± 1°C layer in the North Atlantic.
Using remotely sensed sea surface temperatures and air–sea heat flux estimates based on both analyzed meteorological fields and ocean data–model syntheses for the 3-yr period from 2004 to 2006, the authors find that Eighteen Degree Water (EDW) is formed by air–sea heat fluxes in the western part of the subtropical gyre, just south of the Gulf Stream. The formation rate peaks in February when the EDW layer is thickened by convection owing to buoyancy loss. EDW is destroyed by air–sea heat fluxes from spring to summer over the entire subtropical gyre. In the annual mean there is net EDW formation in the west to the south of the Gulf Stream, and net destruction over the eastern part of the gyre. Results suggest that annual mean formation rates of EDW associated with air–sea fluxes are in the range from 3 to 5 Sv (Sv ≡ 106 m3 s−1). Finally, error estimates are computed from sea surface temperature and heat flux data using an ensemble perturbation method. The transformation/formation patterns are found to be robust and errors mostly affect integral quantities.
The Intrusion Depth of Density Currents Flowing into Stratified Water Bodies
Authors: Wells Mathew , Nadarajah Parthiban 
Published: February 2009

AbstractTheory and laboratory experiments are presented describing the depth at which a density current intrudes into a linearly stratified water column, as a function of the entrainment ratio E, the buoyancy flux in the dense current B, and the magnitude of the stratification N. The main result is that Z ∼ E−1/3B1/3/N. It is shown that the depth of the intrusion scales as Z ∼ (3 ± 1)B1/3/N for laboratory experiments, and as for oceanic density currents. The velocity of a large-scale density current is controlled by a geostrophic balance defined as Ugeo = 0.25g′s/f, where s is the slope and f is the Coriolis parameter. The geostrophic buoyancy flux is then defined by Bgeo = g′Ugeoh, with g′ the reduced gravity and h the thickness of the current. The scaling herein implies that the depth of an oceanic intrusion is relatively insensitive to changes in source water properties but is very sensitive to changes in the stratification of the water column, consistent with the previous scaling of Price and Baringer. For example, if the buoyancy flux of a dense current were to double while the stratification remained constant, then there would only be a 25% increase in the intrusion depth, whereas doubling the stratification would result in a 50% decrease of the intrusion depth.
Origin and Pathway of Equatorial 13°C Water in the Pacific Identified by a Simulated Passive Tracer and Its Adjoint*
Authors: Qu Tangdong , Gao Shan , Fukumori Ichiro , Fine Rana A. , Lindstrom Eric J. 
Published: February 2009

Abstract
The origin and pathway of the thermostad water in the eastern equatorial Pacific Ocean, often referred to as the equatorial 13°C Water, are investigated using a simulated passive tracer and its adjoint, based on circulation estimates of a global general circulation model. Results demonstrate that the source region of the 13°C Water lies well outside the tropics. In the South Pacific, some 13°C Water is formed northeast of New Zealand, confirming an earlier hypothesis on the water’s origin. The South Pacific origin of the 13°C Water is also related to the formation of the Eastern Subtropical Mode Water (ESTMW) and the Sub-Antarctic Mode Water (SAMW). The portion of the ESTMW and SAMW that eventually enters the density range of the 13°C Water (25.8 &lt; σθ &lt; 26.6 kg m−3) does so largely by mixing. Water formed in the subtropics enters the equatorial region predominantly through the western boundary, while its interior transport is relatively small. The fresher North Pacific ESTMW and Central Mode Water (CMW) are also important sources of the 13°C Water. The ratio of the southern versus the northern origins of the water mass is about 2 to 1 and tends to increase with time elapsed from its origin. Of the total volume of initially tracer-tagged water in the eastern equatorial Pacific, approximately 47.5% originates from depths above σθ = 25.8 kg m−3 and 34.6% from depths below σθ = 26.6 kg m−3, indicative of a dramatic impact of mixing on the route of subtropical water to becoming the 13°C Water. Still only a small portion of the water formed in the subtropics reaches the equatorial region, because most of the water is trapped and recirculates in the subtropical gyre.
A Fourier-Based Method for the Distribution of Breaking Crests from Video Observations
Authors: Thomson Jim , Jessup Andrew T. 
Published: February 2009

Abstract
A Fourier-based method is presented to process video observations of water waves and calculate the speed distribution of breaking crest lengths. The method has increased efficiency and robust statistics compared with conventional algorithms that assemble distributions from tracking individual crests in the time domain. The method is tested using field observations (video images of whitecaps) of fetch-limited breaking waves during case studies with low (6.7 m s−1), moderate (8.5 m s−1), and high (12.6 m s−1) wind speeds. The method gives distributions consistent with conventional algorithms, including breaking rates that are consistent with direct observations. Results are applied to obtain remote estimates of the energy dissipation associated with wave breaking.
Toddler feeding: Expectations and experiences of low-income African American mothers
Authors: Horodynski Mildred A , Brophy-Herb Holly , Henry Michelle , Smith Katharine A , Weatherspoon Lorraine 
Published: February 2009

Objective To ascertain maternal expectations and experiences with mealtimes and feeding of toddlers among low-income African American mothers in two mid- to large-size cities in the United States. Design Qualitative focus group study. Setting Two Early Head Start programme sites in a Midwestern state which serve low income families. Method Twenty-seven low-income African American mothers took part in two focus groups which were conducted by a facilitator, according to a semi-structured topic guide. Focus group data were supplemented with demographic family data. Results Four major themes emerged: (1) maternal perceptions of healthy toddlers, (2) maternal food choices for toddlers, (3) maternal expectations about toddler autonomy and self-regulation of feeding, and (4) mealtime context and interaction. Conclusions and implications Data provided examples of maternal expectations and experiences, suggesting the development of healthy feeding patterns among some toddlers and provided evidence of less healthy feeding patterns in others. Evidence of less healthy feeding patterns included limiting toddler autonomy and food regulation, and misinterpretation of normative toddler behaviours. Because parenting practices and perceptions have been reported to contribute to social and environmental influences of obesity, this research could aid development of culturally sensitive nutrition education interventions.
Comparison of isokinetic exercise versus standard exercise training in patients with chronic low back pain: a randomized controlled study
Authors: Sertpoyraz Filiz , Eyigor Sibel , Karapolat Hale , Capaci Kazim , Kirazli Yeşim 
Published: February 2009

Objective: To compare the effectiveness of an isokinetic exercise programme and a standard exercise programme in patients with chronic low back pain in terms of pain, mobility, disability, psychological status and muscle strength. Design: A randomized controlled trial. Setting: An outpatient rehabilitation clinic. Subjects: A total of 40 patients with low back pain were included in the study. Interventions: Patients with low back pain were randomly allocated into group 1 (n=20, isokinetic exercises) and group 2 (n=20, standard exercise). Main measures: Outcome measures included a visual analogue scale (VAS) for pain, fingertip-to-floor test for spinal mobility, Modified Oswestry Low Back Disability Questionnaire (MOLBDQ), Beck Depression Inventory and isokinetic muscle testing. Results: The isokinetic and standard exercise groups demonstrated significant improvement in the VAS, fingertip-to-floor test, MOLBDQ, Beck Depression Inventory scores, and muscle strength compared with the baseline that persisted until the end of the first month (P<0.05). Comparison of both exercise groups in terms of these parameters obtained at the end of the treatment and at the first month after treatment showed no significant difference (P>0.05). Conclusion: Isokinetic and standard exercise programmes have an equal effect in the treatment of low back pain, with no statistically significant difference found between the two programmes. The standard exercise programme was easily performed and had a low cost, making it the preferred option for exercise.
Impaired neutrophil extracellular trap (NET) formation: a novel innate immune deficiency of human neonates
Authors: Yost Christian C. , Cody Mark J. , Harris Estelle S. , Thornton Nathan L. , McInturff Alison M. , Martinez Mark L. , Chandler Nancy B. , Rodesch Christopher K. , Albertine Kurt H. , Petti Cathy A. , Weyrich Andrew S. , Zimmerman Guy A. 
Published: February 2009

AbstractNeutrophils are highly specialized innate effector cells that have evolved for killing of pathogens. Human neonates have a common multifactorial syndrome of neutrophil dysfunction that is incompletely characterized and contributes to sepsis and other severe infectious complications. We identified a novel defect in the antibacterial defenses of neonates: inability to form neutrophil extracellular traps (NETs). NETs are lattices of extracellular DNA, chromatin, and antibacterial proteins that mediate extracellular killing of microorganisms and are thought to form via a unique death pathway signaled by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase–generated reactive oxygen species (ROS). We found that neutrophils from term and preterm infants fail to form NETs when activated by inflammatory agonists—in contrast to leukocytes from healthy adults. The deficiency in NET formation is paralleled by a previously unrecognized deficit in extracellular bacterial killing. Generation of ROSs did not complement the defect in NET formation by neonatal neutrophils, as it did in adult cells with inactivated NADPH oxidase, demonstrating that ROSs are necessary but not sufficient signaling intermediaries and identifying a deficiency in linked or downstream pathways in neonatal leukocytes. Impaired NET formation may be a critical facet of a common developmental immunodeficiency that predisposes newborn infants to infection.
A novel variant on chromosome 7q22.3 associated with mean platelet volume, counts, and function
Authors: Soranzo Nicole , Rendon Augusto , Gieger Christian , Jones Chris I. , Watkins Nicholas A. , Menzel Stephan , Döring Angela , Stephens Jonathan , Prokisch Holger , Erber Wendy , Potter Simon C. , Bray Sarah L. , Burns Philippa , Jolley Jennifer , Falchi Mario , Kühnel Brigitte , Erdmann Jeanette , Schunkert Heribert , Samani Nilesh J. , Illig Thomas , Garner Stephen F. , Rankin Angela , Meisinger Christa , Bradley John R. , Thein Swee Lay , Goodall Alison H. , Spector Tim D. , Deloukas Panos , Ouwehand Willem H. 
Published: February 2009

Abstract
Mean platelet volume (MPV) and platelet count (PLT) are highly heritable and tightly regulated traits. We performed a genome-wide association study for MPV and identified one SNP, rs342293, as having highly significant and reproducible association with MPV (per-G allele effect 0.016 ± 0.001 log fL; P < 1.08 × 10−24) and PLT (per-G effect −4.55 ± 0.80 109/L; P < 7.19 × 10−8) in 8586 healthy subjects. Whole-genome expression analysis in the 1-MB region showed a significant association with platelet transcript levels for PIK3CG (n = 35; P = .047). The G allele at rs342293 was also associated with decreased binding of annexin V to platelets activated with collagen-related peptide (n = 84; P = .003). The region 7q22.3 identifies the first QTL influencing platelet volume, counts, and function in healthy subjects. Notably, the association signal maps to a chromosome region implicated in myeloid malignancies, indicating this site as an important regulatory site for hematopoiesis. The identification of loci regulating MPV by this and other studies will increase our insight in the processes of megakaryopoiesis and proplatelet formation, and it may aid the identification of genes that are somatically mutated in essential thrombocytosis.
Chronological expression ofCiliated Bronchial Epithelium 1during pulmonary development
Authors: Haitchi H. M. , Yoshisue H. , Ribbene A. , Wilson S. J. , Holloway J. W. , Bucchieri F. , Hanley N. A. , Wilson D. I. , Zummo G. , Holgate S. T. , Davies D. E. 
Published: February 2009

Ciliated Bronchial Epithelium(CBE)1is a novel gene, which is expressed in ciliated cells. As cilia are important during embryogenesis, the present authors characterised the murine homologue ofCBE1(Cbe1) and compared its temporal expression during murine and human lung development.Cbe1cDNA was cloned and characterised using sequencing, standard PCR and Western blotting. Mouse and human embryonic/fetal lungs (HELs) were harvested for mRNA analysis and protein localisationin vivoandin vitrousing RT-PCR and immunohistochemistry.The Cbe1 amino acid sequence was >75% identical with CBE1 and its alternative splicing and tissue distribution were highly conserved. Pulmonary expression ofCbe1mRNA was increased at embryonic day (E)16, 1 day later thanFoxj1, which is consistent with a role in ciliogenesis. In HELs,CBE1mRNA was detectable at 8–9 weeks post-conception and increased in explant culture. CBE1 protein expression was weak at 10 weeks post-conception but strong at 12.3 weeks post-conception, in parallel with cilia formation. Additionally,Cbe1mRNA was expressed at E11 (4–5 weeks post-conception in HELs) in the absence ofFoxj1, implying a distinct role in early development.Chronological regulation ofCBE1/Cbe1expression during pulmonary differentiation suggests involvement in ciliogenesis, with an additional role during early lung development.
Iloprost for pulmonary vasodilator testing in idiopathic pulmonary arterial hypertension
Authors: Jing Z-C. , Jiang X. , Han Z-Y. , Xu X-Q. , Wang Y. , Wu Y. , Lv H. , Ma C-R. , Yang Y-J. , Pu J-L. 
Published: February 2009

The aim of this study was to confirm the utility of aerosolised iloprost for identifying long-term responders to calcium channel blockers (CCBs) in patients with idiopathic pulmonary arterial hypertension (IPAH).While undergoing right heart catheterisation, 74 patients with IPAH sequentially received incremental infusions of adenosine and aerosolised iloprost. The effects of the two vasodilators on haemodynamic parameters were recorded. All acute responders identified by aerosolised iloprost were subsequently treated with high doses of a CCB and were re-evaluated after 12 months.Both adenosine and iloprost produced significant decreases in mean pulmonary arterial pressure and pulmonary vascular resistance, and significant increases in cardiac index. Adverse effects were experienced by 35 out of the 74 patients with adenosine, but by only two with iloprost. Aerosolised iloprost identified more acute responders than infused adenosine (10versuseight, respectively) according to the criteria recommended in recent consensus guidelines. Nine responders identified by iloprost were followed-up after 12 months of high-dose CCB therapy. Five had normal or near-normal haemodynamics and a World Health Organization functional classification of I or II after 12 months.Aerosolised iloprost is an appropriate new agent to identify long-term responders to CCBs in patients with IPAH. It is as effective in this regard as infused adenosine but is better tolerated.