bluuebunny/crossref_metadata_2025_split huggingface dataset:
Primary seed dispersal by three Neotropical seed-predating primates (Cacajao melanocephalus ouakary,Chiropotes chiropotesandChiropotes albinasus)
Authors: Barnett Adrian A. , Boyle Sarah A. , Pinto Liliam P. , Lourenço Waldete C. , Almeida Thais , Sousa Silva Welma , Ronchi-Teles Beatriz , Bezerra Bruna M. , Ross Caroline , MacLarnon Ann , Spironello Wilson R. 
Published: November 2012

Abstract:The Neotropics house two guilds of large arboreal vertebrate seed predators: parrots and the pitheciin primates. Both have diets dominated by immature fruits. The possibility of members of the Pitheciinae (generaCacajao,ChiropotesandPithecia) acting as occasional seed dispersers has been mooted, but not experimentally shown. We combined primate behavioural data and seed germination data from three separate field studies in the Brazilian states of Amazonas and Pará to analyse patterns of post-consumption seed survivorship for seeds discarded by three pitheciin species (Cacajao melanocephalus ouakary,Chiropotes chiropotesandChiropotes albinasus). We then calculated the frequency of dispersal events for four species eaten byC. m. ouakary. All three primate species dropped intact seeds while feeding, and 30.7% of 674 dropped seeds germinated ex situ. Undamaged seeds from unripe and ripe samples germinated (29.3% and 42.7%, respectively), and all three primate species carried some fruits up to 20 m from the parent tree before consuming them. Potential seed-dispersal events varied from 1 (Macrolobium acaciifolium) per fruiting cycle to more than 6500 (Duroia velutina), suggesting that there are differences in dispersal potential. In summary, although they are highly specialized seed predators, these primates may also act as important dispersers for some plant species, and effective dispersal is not restricted to ripe fruits, as immature fruits removed from a tree may continue to mature and the seeds later germinate, a much-neglected aspect of dispersal ecology. The possibility that similar events occur in parrots should be experimentally investigated.
Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay, Antarctic Peninsula
Authors: Annett Amber L. , Henley Sian F. , Van Beek Pieter , Souhaut Marc , Ganeshram Raja , Venables Hugh J. , Meredith Michael P. , Geibert Walter 
Published: November 2012

AbstractIn the western Antarctic Peninsula region, micronutrient injection facilitates strong plankton blooms that support productive food webs, unlike large areas of the low-productivity Southern Ocean. We use naturally occurring radioisotopes of radium to constrain rates of chemical fluxes into Ryder Bay (a small coastal embayment in northern Marguerite Bay), and hence to evaluate possible sources of sediment-derived micronutrients and estimate sediment-ocean mixing rates. We present the first coupled, short-lived radium isotope (223Ra and 224Ra) measurements from Antarctic waters, both present at very low activities (mean 0.155 and 3.21 dpm m-3, respectively), indicating much lower radium inputs than in other coastal environments. Longer-lived 228Ra activity was also lower than existing nearshore values, but higher than open ocean waters, indicating some degree of coastal radium input on timescales exceeding the week-to-month range reflected by 223Ra and 224Ra. Using a simple diffusion model along a shore to mid-bay transect, effective horizontal eddy diffusivity estimates ranged from 0.22–0.83 m2 s-1 from 223Ra and 224Ra, respectively, much lower than already-low mixing estimates for the Southern Ocean. Significant radium enrichment and much faster mixing (18 m2 s-1) was found near a marine-terminating glacier and consequently any sediment-derived micronutrient inputs in this location are more probably dominated by glacial processes than groundwater, land runoff, or marine sediment sources.
Spontaneous generation of reactive oxygen species and effect on motility and fertilizability of sea urchin spermatozoa
Authors: Kazama Makoto , Sato Taizo , Hino Akiya 
Published: November 2012

SummaryWe investigated the generation of reactive oxygen species (ROS) by spermatozoa in two species of sea urchin. ROS generation was accompanied by the initiation of motility and respiration and influenced the motility and fertilizability of spermatozoa. The sea urchin performs external fertilization in aerobic seawater. Sperm motility was initiated after spawning through Na+/H+exchange. ROS generation was dependent on the respiration and sperm concentration and its generation was first observed at initiation of motility, via activation of respiration through ATP/ADP transport. The ROS generation rate increased at higher dilution ratios of spermatozoa, in a manner that was synchronous with the respiratory rate. This phenomenon resembled the previously defined ‘sperm dilution effect’ on respiration. The loss of motility and fertilizability was induced not only by treatment with hydrogen peroxide but also by sperm dilution. Storage of spermatozoa with a higher dilution ratio also accelerated the decrease in fertilizability. Thus, optimum sea urchin fertilizability is maintained by storage of undiluted spermatozoa on ice, in order to minimize oxidative stress and to maximize longevity.
Percutaneous device closure of aortico-left ventricular tunnel using Amplatzer vascular plug III
Authors: Thomas Eapen , Maskari Salim , Farqani Abdullah 
Published: November 2012

AbstractAortico-left ventricular tunnel is a rare congenital heart defect. Reports on successful device closure of these defects are scarce. We are reporting the first case of device closure of aortico-left ventricular tunnel using an Amplatzer vascular plug III.
Energy and climate change in China
Authors: Carraro Carlo , Massetti Emanuele 
Published: November 2012

AbstractThis paper examines future energy and emissions scenarios in China generated by the Integrated Assessment Model WITCH. A Business-as-Usual scenario is compared with five scenarios in which greenhouse gases emissions are taxed, at different levels. The elasticity of China's emissions is estimated by pooling observations from all scenarios and comparing them with the elasticity of emissions in OECD countries. China has a higher elasticity than the OECD for a carbon tax lower than US$50 per ton of CO2-eq. For higher taxes, emissions in OECD economies are more elastic than in China. Our best guess indicates that China would need to introduce a tax equal to about US$750 per ton of CO2-eq in 2050 to achieve the Major Economies Forum goal set for mid-century. In our preferred estimates, the discounted cost of following the 2°C trajectory is equal to 5.4 per cent and to 2.7 per cent of GDP in China and the OECD, respectively.
Assessment of the PROBIT approach for estimating the prevalence of global, moderate and severe acute malnutrition from population surveys
Authors: Dale Nancy M , Myatt Mark , Prudhon Claudine , Briend André 
Published: November 2012

AbstractObjectivePrevalence of acute malnutrition is classically estimated by the proportion of children meeting a case definition in a representative population sample. In 1995 the WHO proposed the PROBIT method, based on converting parameters of a normally distributed variable to cumulative probability, as an alternative method requiring a smaller sample size. The present study compares classical and PROBIT methods for estimating the prevalence of global, moderate and severe acute malnutrition (GAM, MAM and SAM) defined by weight-for-heightZ-score (WHZ) or mid-upper arm circumference (MUAC).DesignBias and precision of classical and PROBIT methods were compared by simulating a total of 1·26 million surveys generated from 560 nutrition surveys.SettingData used for simulation were derived from nutritional surveys of children aged 6–59 months carried out in thirty-one countries around the world.SubjectsData of 459 036 children aged 6–59 months from representative samples were used to generate simulated populations.ResultsThe PROBIT method provided an estimate of GAM, MAM and SAM using WHZ or MUAC proportional to the true prevalence with a small systematic overestimation. The PROBIT method was more precise than the classical method for estimating the prevalence for GAM, MAM and SAM by WHZ or MUAC for small sample sizes (i.e.n<150 for SAM and GAM;n<300 for MAM), but lost this advantage when sample sizes increased.ConclusionsThe classical method is preferred for estimating acute malnutrition prevalence from large sample surveys. The PROBIT method may be useful in sentinel-site surveillance systems with small sample sizes.
SOME EXACT ALGEBRAIC EXPRESSIONS FOR THE TAILS OF TASOEV CONTINUED FRACTIONS
Authors: KOMATSU TAKAO 
Published: November 2012

AbstractDenote the nth convergent of the continued fraction α=[a0;a1,a2,…] by pn/qn=[a0;a1,…,an]. In this paper we give exact formulae for the quantities Dn:=qnα−pn in several typical types of Tasoev continued fractions. A simple example of the type of Tasoev continued fraction considered is α=[0;ua,ua2,ua3,…].
PRODUCTS OF SHIFTED PRIMES SIMULTANEOUSLY TAKING PERFECT POWER VALUES
Authors: FREIBERG TRISTAN 
Published: November 2012

AbstractLetrbe an integer greater than 1, and letAbe a finite, nonempty set of nonzero integers. We obtain a lower bound for the number of positive squarefree integersn, up tox, for which the products ∏p∣n(p+a) (over primesp) are perfectrth powers for all the integersainA. Also, in the cases whereA={−1} andA={+1}, we will obtain a lower bound for the number of suchnwith exactlyrdistinct prime factors.
COUNTING FIXED POINTS, TWO-CYCLES, AND COLLISIONS OF THE DISCRETE EXPONENTIAL FUNCTION USING p-ADIC METHODS
Authors: HOLDEN JOSHUA , ROBINSON MARGARET M. 
Published: November 2012

AbstractBrizolis asked for which primes p greater than 3 there exists a pair (g,h) such that h is a fixed point of the discrete exponential map with base g, or equivalently h is a fixed point of the discrete logarithm with base g. Various authors have contributed to the understanding of this problem. In this paper, we use p-adic methods, primarily Hensel’s lemma and p-adic interpolation, to count fixed points, two-cycles, collisions, and solutions to related equations modulo powers of a prime p.
Roth versus traditional accounts in a life-cycle model with tax risk
Authors: LACHANCE MARIE-EVE 
Published: November 2012

AbstractThis paper analytically solves a life-cycle model that compares traditional and Roth retirement accounts. It includes realistic features such as tax deductibility of contributions and taxation of withdrawals, tax bracket structure with deductions, taxation of Social Security benefits, and tax risk at retirement. With current taxes, choosing a traditional account over a Roth creates small welfare losses in only a few cases, largely for those with higher incomes and pensions who are subject to the taxation of Social Security benefits. We also investigate tax variability and find that diversified strategies offer only small risk reduction benefits in our illustrations.
Powdery mildew resistance in some new wheat amphiploids (2n = 6x = 42) derived from A- and S-genome diploid progenitors
Authors: Rafique Khola , Rasheed Awais , Kazi Alvina Gul , Bux Hadi , Naz Farah , Mahmood Tariq , Mujeeb-Kazi Abdul 
Published: November 2012

Triticum urartu possesses the Au genome common to bread wheat. Similarly, Triticum monococcum contains the Am genome, which is closely related to the A-genome donor of bread wheat. Aegilops speltoides of the Sitopsis section has the S genome, which is most similar to the B genome of bread and durum wheat when compared with all other wild grasses. Amphiploids developed through bridge crossing between Am/Au and S-genome diploid resources and elite durum cultivars demonstrate enormous diversity to improve both bread and durum wheat cultivars. We evaluated such A-genome amphiploids (Triticum turgidum × T. urartu and T. turgidum × T. monococcum, 2n = 6x = 42; BBAAAmAm/AuAu) and S-genome amphiploids (T. turgidum × Ae. speltoides, 2n = 6x = 42; AABBSS) along with their durum parents (AABB) for their resistance to powdery mildew (PM) at the seedling stage. The results indicated that 104 accessions (53.6%) of A-genome amphiploids (AABBAmAm/AuAu) were resistant to PM at the seedling stage. Of their 24 durum parents, five (20.83%) were resistant to PM and 16 (66.6%) were moderately tolerant. Similarly, ten (50%) accessions of S-genome amphiploids (BBAASS) possessed seedling PM resistance, suggesting a valuable source of major resistance genes. PM screening of the amphiploids and parental durum lines showed that resistance was contributed either by the diploid progenitors or durum parents, or both. We also observed the suppression of resistance in several cases; for example, resistance in durum wheat was suppressed in respective amphiploids. The results from this germplasm screening will facilitate their utilization to genetically control PM and widen the genetic base of wheat.
Longitudinal and seasonal structure of the ionospheric equatorial electric field
Authors: Alken P. , Chulliat A. , Maus S. 
Published: November 2012

AbstractThe daytime eastward equatorial electric field (EEF) in the ionospheric E‐region plays an important role in equatorial ionospheric dynamics. It is responsible for driving the equatorial electrojet (EEJ) current system, equatorial vertical ion drifts, and the equatorial ionization anomaly. Due to its importance, there is much interest in accurately measuring and modeling the EEF. In this work we propose a method of estimating the EEF using CHAMP satellite‐derived latitudinal current profiles of the daytime EEJ along with Δ H measurements from ground magnetometer stations. Magnetometer station pairs in both Africa and South America were used for this study to produce time series of electrojet current profiles. These current profiles were then inverted for estimates of the EEF by solving the governing electrostatic equations. We compare our results with the Ion Velocity Meter (IVM) instrument on board the Communication/Navigation Outage Forecasting System satellite. We find high correlations of about 80% with the IVM data; however, we also find a constant offset of about 0.3 mV/m between the two data sets in Africa. Further investigation is needed to determine its cause. We compare the EEF structure in Africa and South America and find differences which can be attributed to the effect of atmospheric nonmigrating tides. This technique can be extended to any pair of ground magnetometer stations which can capture the day‐to‐day strength of the EEJ.
Full‐depth desalination of warm sea ice
Authors: Jardon F. P. , Vivier F. , Vancoppenolle M. , Lourenço A. , Bouruet‐Aubertot P. , Cuypers Y. 
Published: November 2012

AbstractThe large‐scale Arctic sea‐ice retreat induces a gradual replacement of thick, multi‐year sea ice by thinner first‐year ice. The latter has distinctive physical properties and is in particular substantially saltier. It is generally thought that while salt rejection occurs primarily during ice formation in winter, most of the remaining brine is flushed out of the ice by the percolating surface melt water in summer. Here, it is argued that a substantial part of this residual desalination of first‐year sea ice can occur well before summer melt, due to brine convection over the full thickness of the ice, once the ice temperature is higher than a threshold that depends on bulk salinity and thickness. This critical temperature is substantially higher than the permeability threshold. The argument stems from a theoretical analysis of the porous Rayleigh number depicting the propensity for convection in the mushy‐layer theory. It is supported by simulations performed with a state‐of‐the‐art 1‐D sea‐ice model. The study was initially motivated by observations collected in March 2007 in Storfjorden, Svalbard. Those are indirect, however, and are thus presented here as a possible example. Two sporadic anomalies of seawater salinity were recorded close to the base of 40 cm thick ice in temperature conditions that are incompatible with ice formation. Analyses and simulations forced with observed atmospheric conditions suggest that the second peak is caused by flushing of meltwater, while the first and most intense peak is likely associated with an episode of brine convection over the full depth of the ice, yielding significant desalination.
An improved oceanic budget for methyl chloride
Authors: Hu Lei , Yvon‐Lewis Shari A. , Butler James H. , Lobert Jürgen M. , King Daniel B. 
Published: November 2012

AbstractWe present results that improve the estimates of the global net sea‐to‐air flux, global oceanic emission, global oceanic uptake, and partial atmospheric lifetime of methyl chloride (CH3Cl) with respect to oceanic loss. This study includes improved parameterizations for solubility and saturation anomaly‐sea surface temperature relationships for CH3Cl, along with the use of an updated gas transfer velocity from a recent study. By measuring solubilities of CH3Cl in pure water and seawater over a temperature range from 0°C to 40°C, we obtained a new solubility function with both temperature and salinity dependencies. We also developed a new parameterization of seasonal CH3Cl saturation anomaly (∆%) as a function of both sea surface temperature and wind speed using data from 10 different cruises with an extensive coverage in the global surface ocean. Using the new solubility function and the new seasonal ∆%‐(SST, wind speed) relationships, we estimated the global net sea‐to‐air flux of CH3Cl at 335 (210 to 480) Gg yr−1. For the first time, the global flux of CH3Cl was broken into a unidirectional gross emission and a unidirectional gross uptake, which were estimated at 700 (510 to 910) Gg yr−1 and −370 (−430 to −300) Gg yr−1. The partial atmospheric lifetime of CH3Cl with respect to the oceanic uptake was revised to 12 (10–15) years, resulting in a revision on the atmospheric lifetime of CH3Cl from the previous estimate of 1.0 year to 1.2 years.
Limited capacity of river corridor wetlands to remove nitrate: A case study on the Atchafalaya River Basin during the 2011 Mississippi River Flooding
Authors: BryantMason April , Jun Xu Y. , Altabet Mark A. 
Published: November 2012

Key Points
Flow‐through systems may be ineffective in reducing river nitrate during flood
Limited residence time limited nitrate processing
Higher NO3N leaching from subsurface soils during post‐flood period in upper MR
Assessing Avian Predation on Juvenile Salmonids using Passive Integrated Transponder Tag Recoveries and Mark–Recapture Methods
Authors: Frechette Danielle , Osterback Ann-Marie K. , Hayes Sean A. , Bond Morgan H. , Moore Jonathan W. , Shaffer Scott A. , Harvey James T. 
Published: November 2012

Abstract
Many populations of coho salmon Oncorhynchus kisutch and steelhead O. mykiss are listed under the U.S. Endangered Species Act. Until recently, the role of avian predation in limiting recovery of coho salmon and steelhead in central California coastal watersheds has been overlooked. We used recoveries of passive integrated transponder (PIT) tags from Año Nuevo Island (ANI), a breeding site for several species of piscivorous seabirds, to estimate predation rates on juvenile salmonids and identify susceptible life stages and species responsible for predation. A total of 34,485 PIT tags were deployed in coho salmon and steelhead in six watersheds in San Mateo and Santa Cruz counties. Tags were deposited on ANI by predators after ingestion of tagged fish. Because tags were not removed from the island and were detected on multiple sampling occasions, we were able to use mark–recapture models to generate a corrected minimum predation estimate. We used POPAN, a variation of the Jolly–Seber model, to generate an estimate of gross population abundance, which accounted for tags deposited on the island but not detected during surveys. Detections of 196 tags from surveys conducted between autumn 2006 and spring 2009 were incorporated into the model, producing a gross population estimate of 242 tags (SE = 9.8). Addition of tags detected between autumn 2009 and 2010 to the abundance estimate from POPAN produced a new minimum estimate of 362 tags on ANI. Western gulls Larus occidentalis probably were the primary predator depositing tags on ANI. Minimum predation estimates ranged from 0.1% (Soquel Creek) to 4.6% (Waddell Creek) of outmigrating coho salmon and steelhead smolts. Predation was potentially greater given still unquantified deposition of tags off-colony and destruction of tags during digestive processes of predators. Finally, avian predators targeted estuary-reared fish, which contributed disproportionately to adult populations, further impacting imperiled salmon populations.
Received August 4, 2011; accepted August 27, 2012
Statistical features of coherent structures at increasing magnetic field pitch investigated using fast imaging in QUEST
Authors: Banerjee Santanu , Zushi H. , Nishino N. , Hanada K. , Sharma S.K. , Honma H. , Tashima S. , Inoue T. , Nakamura K. , Idei H. , Hasegawa M. , Fujisawa A. 
Published: November 2012

Abstract
Fluctuations in slab plasma produced by electron cyclotron waves in an open magnetic configuration with vertical (B

z
) and toroidal (B
t) fields are investigated as a function of B

z
/B
t (field pitch) using a high speed visible camera in the spherical tokamak QUEST. Higher order moments (skewness s and kurtosis k) of spatio-temporal fluctuations are investigated. Background fluctuations, generation of coherent convective structures (blobs) and their propagation are analysed at the intensity gradient (R
im) and the source-free (essentially vacuum on the low-field side) regions, respectively. Parabolic relation (k = As
2 + C) is observed between s and k on the entire R–Z plane for a wide range of B

z
/B
t. Progressive shift from the Gaussian statistics beyond R
im is observed with increasing B

z
/B
t. From the moments of the probability density functions, possible location for blob generation is inferred to be R
im. Direct correspondence is observed with the prominence of the blobs and increase in stochastic forces with the increase in field pitch. Distribution of waiting time suggests that the blob generation may be a Poisson process. Accelerated cross field transport is observed for reasonably large-sized blobs.
Undergraduate students' interaction with online information resources in their academic tasks
Authors: He Daqing , Wu Dan , Yue Zhen , Fu Anna , Thien Vo Kim 
Published: November 2012

PurposeThis paper aims to identify the opinions of undergraduate students on the importance of internet‐based information sources when they undertake academic tasks.Design/methodology/approachBased on a set of identified typical academic tasks for undergraduate students, three research questions were designed around the students' usage and views of information resources for completing these tasks. Web‐accessible questionnaires were used to collect data from participants in two universities in the USA and China, and the data were analyzed using quantitative methods, which included several statistic methods.FindingsThe results confirm that undergraduate students use different information resources for various academic tasks. In their tasks, online electronic resources including search engines are the most commonly used resources, particularly for complex academic tasks. Social networking sites are not used for the students' individual academic tasks, and traditional resources still play equal or more important roles in certain specific academic tasks. Students in collaborative tasks look for resources that make it easy to share documents. Participants from the two countries also exhibit interesting and important differences in their usage of information resources.Originality/valueThis study examines undergraduate students' usages and views of different information resources in their various academic tasks, and pays special attention to the impacts of being from their different countries. The study also considers both students' individual academic tasks and collaborative tasks. This study is an invaluable addition to the information seeking behaviour literature.