bluuebunny/crossref_metadata_2025 huggingface dataset:
Host–tree oviposition preference of balsam fir sawfly, Neodiprion abietis (Hymenoptera: Diprionidae), in New Brunswick, Canada
Authors: Johns Rob C. , Fidgen J. , Ostaff Don P.
Published: May 2013

Laboratory experiments using field-collected females were carried out to determine the oviposition preference of the balsam fir sawfly, Neodiprion abietis (Harris) (Hymenoptera: Diprionidae) in New Brunswick, Canada. Unmated adult females given no choice among host–plant foliage laid ∼98% of available eggs on balsam fir (Abies balsamea (Linnaeus) Miller; Pinaceae), but only 8% and 10%, respectively, on white spruce (Picea glauca (Moench) Voss; Pinaceae) and black spruce (Picea mariana (Miller) Britton, Sterns, and Poggenburg). Given a choice among shoots from all three hosts in the same chamber, unmated females laid all but one egg in balsam fir. Host plant had no effect on female longevity, although there were nearly four- to eightfold more empty egg slits on balsam fir needles, owing presumably to the greater activity of females on this preferred host foliage.
Athletic Trainer Perceptions of Life-Work Balance and Parenting Concerns
Authors: Eberman Lindsey E. , Kahanov Leamor
Published: May 2013

Context:

Life-work balance may be one reason for retention concerns among athletic trainers (ATs), yet evidence does not exist to support the supposition.

Objective:

To assess the perceptions of ATs regarding life-work balance, specifically on parenting issues.

Design:

Survey.

Setting:

Online survey at www.surveymonkey.com.

Patients or Other Participants:

A random sample of National Athletic Trainers' Association members (N = 9516) received the survey; 20.6% (n = 1962; male = 954, female = 816; age = 37 ± 10 years, experience = 13 ± 9 years) completed any portion of the survey. Most respondents worked in the college/university (34.5%, n = 657 of 1908) and secondary school settings (25.9%, n = 476 of 1908). A majority of participants (50.7%, n = 898 of 1770) were parents.

Intervention(s):

We calculated frequencies and percentages and used Mann-Whitney U tests and Kruskal-Wallis tests to identify the differences between sexes and among job settings on life-work balance measures among parents.

Main Outcome Measures:

The questionnaire included 8 life-work balance items, 7 parenting challenge items, and 3 nonparent items.

Results:

The results indicate that sex and setting significantly affected perceptions about parenting. Males articulated a stronger sense of difficulty in finding balance as a working parent (P < .001; 1.95 ± 1.98). Females felt more strongly than males that managing work and family was stressful (P = .04; 3.86 ± 1.13) and caused burnout (P = .004; 3.50 ± 1.24), and that their energy tended to fall short of their needs (P < .001; 3.74 ± 1.15). The decision not to have children was strongly affected by the work setting (P = .014; 3.37 ± 1.42). Both college/university (4.14 ± 0.85) and secondary school (4.03 ± 0.90) ATs would prefer to spend more time at home, as compared with ATs in other settings (P < .001). College/university ATs (P = .025; 3.17 ± 1.23) felt most strongly that their families were neglected because of work. In none of the settings did ATs feel that their employment settings were particularly tolerant of their parenting responsibilities (P = .027; 1.72 ± 1.97).

Conclusions:

Male and female employees had similar perceptions of life-work balance, but occupational setting may affect these perceptions.
Changes in Lower Extremity Biomechanics Due to a Short-Term Fatigue Protocol
Authors: Cortes Nelson , Greska Eric , Kollock Roger , Ambegaonkar Jatin , Onate James A.
Published: May 2013

Context:

Noncontact anterior cruciate ligament injury has been reported to occur during the later stages of a game when fatigue is most likely present. Few researchers have focused on progressive changes in lower extremity biomechanics that occur throughout fatiguing.

Objective:

To evaluate the effects of a sequential fatigue protocol on lower extremity biomechanics during a sidestep-cutting task (SS).

Design:

Controlled laboratory study.

Setting:

Laboratory.

Patients or Other Participants:

Eighteen uninjured female collegiate soccer players (age = 19.2 ± 0.9 years, height = 1.66 ± 0.5 m, mass = 61.6 ± 5.1 kg) volunteered.

Intervention(s):

The independent variable was fatigue level, with 3 levels (prefatigue, 50% fatigue, and 100% fatigue). Using 3-dimensional motion capture, we assessed lower extremity biomechanics during the SS. Participants alternated between a fatigue protocol that solicited different muscle groups and mimicked actual sport situations and unanticipated SS trials. The process was repeated until fatigue was attained.

Main Outcome Measure(s):

Dependent variables were hip- and knee-flexion and abduction angles and internal moments measured at initial contact and peak stance and defined as measures obtained between 0% and 50% of stance phase.

Results:

Knee-flexion angle decreased from prefatigue (−17° ± 5°) to 50% fatigue (−16° ± 6°) and to 100% fatigue (−14° ± 4°) (F2,34 = 5.112, P = .004). Knee flexion at peak stance increased from prefatigue (−52.9° ± 5.6°) to 50% fatigue (−56.1° ± 7.2°) but decreased from 50% to 100% fatigue (−50.5° ± 7.1°) (F2,34 = 8.282, P = 001). Knee-adduction moment at peak stance increased from prefatigue (0.49 ± 0.23 Nm/kgm) to 50% fatigue (0.55 ± 0.25 Nm/kgm) but decreased from 50% to 100% fatigue (0.37 ± 0.24) (F2,34 = 3.755, P = 03). Hip-flexion angle increased from prefatigue (45.4° ± 10.9°) to 50% fatigue (46.2° ± 11.2°) but decreased from 50% to 100% fatigue (40.9° ± 11.3°) (F2,34 = 6.542, P = .004). Hip flexion at peak stance increased from prefatigue (49.8° ± 9.9°) to 50% fatigue (52.9° ± 12.1°) but decreased from 50% to 100% fatigue (46.3° ± 12.9°) (F2,34 = 8.639, P = 001). Hip-abduction angle at initial contact decreased from prefatigue (−13.8° ± 6.6°) to 50% fatigue (−9.1° ± 6.5°) and to 100% fatigue (−7.8° ± 6.5°) (F2,34 = 11.228, P < .001). Hip-adduction moment decreased from prefatigue (0.14 ± 0.13 Nm/kgm) to 50% fatigue (0.08 ± 0.13 Nm/kgm) and to 100% fatigue (0.06 ± 0.05 Nm/kg) (F2,34 = 5.767, P = .007).

Conclusions:

The detrimental effects of fatigue on sagittal and frontal mechanics of the hip and knee were visible at 50% of the participants' maximal fatigue and became more marked at 100% fatigue. Anterior cruciate ligament injury-prevention programs should emphasize feedback on proper mechanics throughout an entire practice and not only at the beginning of practice.
Non Completely Solvable Systems of Complex First Order PDE's
Authors: Hill C. Denson , Nacinovich Mauro
Published: May 2013

We revisit the lack of local solvability for homogeneous vector fields with smooth complex valued coefficients, in the spirit of Nirenberg's three dimensional example. First we provide a short expository proof, in the case of
CR
dimension one, with arbitrary
CR
codimension. Next we pass to Lorenzian structures with any
CR
codimension

\geq 1

and
CR
dimension

\geq 2

. Several different approaches are presented. Finally we discuss the connection with the absence of the Poincare lemma and the failure of local
CR
embeddability, and present a global example.
Study of the Anatomical Variations in the Middle Meatus on Nasal Endoscopy
Authors: Bist SS , Mishra Sarita , Agrawal Vinish , Kabdwal Namita
Published: May 2013

Introduction

The anatomical variations of the lateral wall of nose may create technical difficulties during surgery and increase predisposition for chronic rhinosinusitis (CRS). Various cadaveric and radiological studies have been carried out to identify the variations of critical landmarks in sinonasal anatomy. However, studies analyzing the nasal endoscopic examination of living patients are scarce.

Objective

The aim of the study was to compare the anatomical variations in the middle meatus of patients having CRS with that of normal population.

Materials and methods

This was a prospective clinical study, where 700 subjects (1,400 middle meatus) were subjected to diagnostic nasal endoscopy, over a period of 2 years. A total of 350 subjects each with CRS and normal population were included in the case and control group, respectively. Endoscopic examination of nasal cavity was done to observe the middle meatus configuration.

Results

The anatomical variations in the case group were significantly higher that of control. The most common atypical anatomical presentation in both the case and control group were atypical agger nasi (14vs7%, p-value = 0.0001), concha bullosa in middle turbinate (12vs9%, p-value = 0.0809), medially projected uncinate process (10vs4%, p-value = 0.0001), and sausage shaped ethmoid bulla (18vs10%, p-value = 0.0001). Interestingly, opening of ethmoid bulla was also observed in both the groups.

Conclusion

The prevalence of anatomic variations is significantly higher in the case group. However, the detection of a single anatomical variant itself does not establish the genesis of pathophysiology of CRS. Familiarity with such anatomy is important to optimize surgical treatment of sinus disease, while avoiding complications.

How to cite this article

Bist SS, Varshney S, Bhagat S, Mishra S, Agrawal V, Kabdwal N. Study of the Anatomical Variations in the Middle Meatus on Nasal Endoscopy. Clin Rhinol An Int J 2013;6(1):16-21.
Modeling organic aerosol from the oxidation of α-pinene in a Potential Aerosol Mass (PAM) chamber
Authors: Chen S. , Brune W. H. , Lambe A. T. , Davidovits P. , Onasch T. B.
Published: May 2013

Abstract. A model has been developed to simulate the formation and evolution of secondary organic aerosol (SOA) and was tested against data produced in a Potential Aerosol Mass (PAM) flow reactor and a large environmental chamber. The model framework is based on the two-dimensional volatility basis set approach (2D-VBS), in which SOA oxidation products in the model are distributed on the 2-D space of effective saturation concentration (Ci*) and oxygen-to-carbon ratio (O : C). The modeled organic aerosol mass concentrations (COA) and O : C agree with laboratory measurements within estimated uncertainties. However, while both measured and modeled O : C increase with increasing OH exposure as expected, the increase of modeled O : C is rapid at low OH exposure and then slows as OH exposure increases while the increase of measured O : C is initially slow and then accelerates as OH exposure increases. A global sensitivity analysis indicates that modeled COA values are most sensitive to the assumed values for the number of Ci* bins, the heterogeneous OH reaction rate coefficient, and the yield of first-generation products. Modeled SOA O : C values are most sensitive to the assumed O : C of first-generation oxidation products, the number of Ci* bins, the heterogeneous OH reaction rate coefficient, and the number of O : C bins. All these sensitivities vary as a function of OH exposure. The sensitivity analysis indicates that the 2D-VBS model framework may require modifications to resolve discrepancies between modeled and measured O : C as a function of OH exposure.
Stratospheric ozone interannual variability (1995–2011) as observed by lidar and satellite at Mauna Loa Observatory, HI and Table Mountain Facility, CA
Authors: Kirgis G. , Leblanc T. , McDermid I. S. , Walsh T. D.
Published: May 2013

Abstract. The Jet Propulsion Laboratory (JPL) lidars, at the Mauna Loa Observatory, Hawaii (MLO, 19.5° N, 155.6° W) and the JPL Table Mountain Facility (TMF, California, 34.5° N, 117.7° W), have been measuring vertical profiles of stratospheric ozone routinely since the early 1990's and late-1980s respectively. Interannual variability of ozone above these two sites was investigated using a multi-linear regression analysis on the deseasonalised monthly mean lidar and satellite time-series at 1 km intervals between 20 and 45 km from January 1995 to April 2011, a period of low volcanic aerosol loading. Explanatory variables representing the 11 yr solar cycle, the El Niño Southern Oscillation, the Quasi-Biennial Oscillation, the Eliassen-Palm flux, and horizontal and vertical transport were used. A new proxy, the mid-latitude Ozone Depleting Gas Index, which shows a decrease with time as an outcome of the Montreal Protocol, was introduced and compared to the more commonly used linear trend method. The analysis also compares the lidar time-series and a merged time-series obtained from the space-borne Stratospheric Aerosol and Gas Experiment II, Halogen Occultation Experiment, and Aura-Microwave Limb Sounder instruments. The results from both lidar and satellite measurements are consistent with recent model simulations which propose changes in tropical upwelling. Additionally, at TMF the Ozone Depleting Gas Index explains as much variance as the Quasi-Biennial Oscillation in the upper stratosphere. Over the past 17 yr a diminishing downward trend in ozone was observed before 2000 and a net increase, and sign of ozone recovery, is observed after 2005. Our results which include dynamical proxies suggest possible coupling between horizontal transport and the 11 yr solar cycle response, although a dataset spanning a period longer than one solar cycle is needed to confirm this result.
Aerosol mixing state, hygroscopic growth and cloud activation efficiency during MIRAGE 2006
Authors: Lance S. , Raatikainen T. , Onasch T. B. , Worsnop D. R. , Yu X.-Y. , Alexander M. L. , Stolzenburg M. R. , McMurry P. H. , Smith J. N. , Nenes A.
Published: May 2013

Abstract. Observations of aerosol hygroscopic growth and CCN activation spectra for submicron particles are reported for the T1 ground site outside of Mexico City during the MIRAGE 2006 campaign. κ-Köhler theory is used to evaluate the characteristic hygroscopicity parameter, κ*, for the CCN active aerosol population using both size-resolved HTMDA and size-resolved CCNc measurements. Organic mass fractions (forg) are evaluated from size-resolved aerosol mass spectrometer (AMS) measurements, from which predictions of the hygroscopicity parameter are compared against κ*. Strong diurnal changes in aerosol water uptake parameters and aerosol composition are observed. We find that new particle formation (NPF) events are correlated with an increased κ* and CCN-active fraction during the daytime, with greater impact on smaller particles. During NPF events, the number concentration of 40 nm particles acting as CCN at 0.51% ± 0.06% supersaturation can surpass by more than a factor of two the corresponding concentrations of 100 nm particles. We also find that at 06:00–08:00 LT throughout the campaign, fresh traffic emissions result in substantial changes to the chemical distribution of the aerosol, with on average 65% externally mixed fraction for 40 nm particles and 30% externally mixed fraction for 100 nm particles, whereas at midday nearly all particles of both sizes can be described as "internally mixed". Average activation spectra and growth factor distributions are analyzed for different time periods characterizing the daytime (with and without NPF events), the early morning "rush hour" and the entire campaign. We show that κ* derived from CCNc measurements decreases as a function of size during all time periods, while the CCN-active fraction increases as a function of size. Size-resolved AMS measurements do not predict the observed trend for κ* versus particle size, which can be attributed to unresolved mixing state and the presence of refractory material not measured by the AMS. Measured κ* typically ranges from 0.2 to 0.35, and organics typically make up 60–85 % of the aerosol mass in the size range studied. We show that κAMS is able to describe CCN concentrations reasonably well, provided mixing-state information is available, especially at the highest CCN concentrations. This is consistent with other CCN studies carried out in urban environments, and is partly due to the fact that the highest CCN concentrations occur during the daytime when the aerosol is internally mixed. During the early morning rush hour, however, failing to account for the aerosol mixing state results in systematic overestimation of CCN concentrations by as much as 50–100% on average.
Chemical evolution of organic aerosol in Los Angeles during the CalNex 2010 study
Authors: Holzinger R. , Goldstein A. H. , Hayes P. L. , Jimenez J. L. , Timkovsky J.
Published: May 2013

Abstract. During the CalNex study (15 May to 16 June 2010) a large suite of instruments was operated at the Los Angeles area ground supersite to characterize the sources and atmospheric processing of atmospheric pollution. The thermal-desorption proton-transfer-reaction mass-spectrometer (TD-PTR-MS) was deployed to an urban area for the first time and detected 691 organic ions in aerosol samples, the mean total concentration of which was estimated as 3.3 μg m−3. Based on comparison to total organic aerosol (OA) measurements, we estimate that approximately 50% of the OA mass at this site was directly measured by the TD-PTR-MS. Based on correlations with aerosol mass spectrometer (AMS) OA components, the ions were grouped to represent hydrocarbon-like OA (HOA), local OA (LOA), semi-volatile oxygenated OA (SV-OOA), and low volatility oxygenated OA (LV-OOA). Mass spectra and thermograms of the ion groups are mostly consistent with the assumed sources and/or photochemical origin of the OA components. The mass spectra of ions representing the primary components HOA and LOA included the highest m/z, consistent with their higher resistance to thermal decomposition, and they were volatilized at lower temperatures. Photochemical ageing weakens C-C bond strengths (also resulting in chemical fragmentation), and produces species of lower volatility (through the addition of functional groups). Accordingly the mass spectra of ions representing the oxidized OA components (SV-OOA, and LV-OOA) lack the highest masses and they are volatilized at higher temperatures. Chemical parameters like mean carbon number (nC), mean carbon oxidation state (OSC), and the atomic ratios O/C and H/C of the ion groups are consistent with the expected sources and photochemical processing of the aerosol components. Our data suggest that chemical fragmentation gains importance over functionalization as photochemical age of OA increases. Surprisingly, the photochemical age of OA decreases during the daytime hours, demonstrating the importance of rapid production of new (photochemically young) SV-OOA during daytime. The PTR detects higher organic N concentrations than the AMS, the reasons for which are not well understood and cannot be explained by known artifacts related to PTR or the AMS. The median atomic N/C ratio (6.4%) of the ion group representing LV-OOA is a factor 2 higher than N/C of any other ion group. This suggests a multiphase chemical source involving ammonium ions is contributing to LV-OOA.
The balances of mixing ratios and segregation intensity: a case study from the field (ECHO 2003)
Authors: Dlugi R. , Berger M. , Zelger M. , Hofzumahaus A. , Rohrer F. , Holland F. , Lu K. , Kramm G.
Published: May 2013

Abstract. An inhomogeneous mixing of reactants causes a reduction of their chemical removal compared to the homogeneously mixed case in turbulent atmospheric flows. This can be described by the intensity of segregation IS being the covariance of the mixing ratios of two species divided by the product of their means. Both terms appear in the balance equation of the mixing ratio and are discussed for the reaction between isoprene and OH for data of the field study ECHO 2003 above a deciduous forest. For most of these data, IS is negatively correlated with the fraction of mean OH mixing ratio reacting with isoprene. IS is also negatively correlated with the isoprene standard deviation. Both findings agree with model results discussed by Patton et al. (2001) and others. The correlation coefficient between OH and isoprene, and, therefore, IS increases with increasing mean reaction rate. In addition, the balance equation of the covariance between isoprene and OH is applied for the analysis of the same field data. The storage term is small, and, therefore, a diagnostic equation for this covariance can be derived. The chemical reaction term Rij is dominated by the variance of isoprene times the quotient of mixing ratios of OH and isoprene. In addition a diagnostic equation for IS is formulated. Comparing different terms of this equation, IS and Rij show a relation also to the normalized isoprene standard deviation. It is shown that not only chemistry, but also turbulent and convective mixing and advection – considered in a residual term – influence IS. Despite this finding, a detection of the influence of coherent eddy transport above the forest according to Katul et al. (1997) on IS fails, but a relation with the turbulent transport of isoprene variance is determined. In addition, largest values of IS are found for most unstable conditions with increasing buoyancy. These results are compared to model results by Ouwersloot et al. (2011).
Reconstruction of Northern Hemisphere 1950–2010 atmospheric non-methane hydrocarbons
Authors: Helmig D. , Petrenko V. , Martinerie P. , Witrant E. , Röckmann T. , Zuiderweg A. , Holzinger R. , Hueber J. , Stephens C. , White J. , Sturges W. , Baker A. , Blunier T. , Etheridge D. , Rubino M. , Tans P.
Published: May 2013

Abstract. The short-chain non-methane hydrocarbons (NMHC) are mostly emitted into the atmosphere by anthropogenic processes. Recent studies have pointed out a tight linkage between the atmospheric mole fractions of the NMHC ethane to the atmospheric growth rate of methane. Consequently, atmospheric NMHC are valuable indicators for tracking changes in anthropogenic emissions, photochemical ozone production, and greenhouse gases. This study investigates the 1950–2010 Northern Hemisphere atmospheric C2-C5 NMHC ethane, propane, i-butane, n-butane, i-pentane, and n-pentane. Atmospheric mole fractions of these trace gases were constructed from (a) air samples of these trace gases from air samples extracted from three firn boreholes in 2008 and 2009 at the North Greenland Eemian Ice Drilling (NEEM) site using state of the art models of trace gas transport in firn, and by (b) considering eight years of ambient NMHC monitoring data from five Arctic sites within the NOAA Global Monitoring Division (GMD) Cooperative Air Sampling Network. Results indicate that these NMHC increased by ~ 40–120% after 1950, peaked around 1980 (with the exception of ethane, which peaked approximately 10 years earlier), and have since dramatically decreased to be now back close to 1950 levels. The earlier peak time of ethane versus the C3-C5 NMHC suggests that different processes and emissions mitigation measures contributed to the decline in these NMHC. The 60 yr record also illustrates notable increases in the ratios of the isomeric iso-/n-butane and iso-/n-pentane ratios. Comparison of the reconstructed NMHC histories with 1950–2000 volatile organic compounds (VOC) emissions data and with other recently published ethane trend analyses from ambient air Pacific transect data showed (a) better agreement with North America and Western Europe emissions than with total Northern Hemisphere emissions data, and (b) better agreement with other Greenland firn air data NMHC history reconstructions than with the Pacific region trends. These analyses emphasize that for NMHC, having atmospheric lifetimes on the order of < 2 months, the Greenland firn air records are primarily a representation of Western Europe and North America emission histories.
On the optimal method for evaluating cloud products from passive satellite imagery using CALIPSO-CALIOP data: example investigating the CM SAF CLARA-A1 dataset
Authors: Karlsson K.-G. , Johansson E.
Published: May 2013

Abstract. A method for detailed evaluation of a new satellite-derived global 28 yr cloud and radiation climatology (Climate Monitoring SAF Clouds, Albedo and Radiation from AVHRR data, named CLARA-A1) from polar-orbiting NOAA and Metop satellites is presented. The method combines 1 km and 5 km resolution cloud datasets from the CALIPSO-CALIOP (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation – Cloud-Aerosol Lidar with Orthogonal Polarization) cloud lidar for estimating cloud detection limitations and the accuracy of cloud top height estimations. Cloud detection is shown to work efficiently for clouds with optical thicknesses above 0.30 except for at twilight conditions when this value increases to 0.45. Some misclassifications of cloud-free surfaces during daytime were revealed for semi-arid land areas in the sub-tropical and tropical regions leading to up to 20% overestimated cloud amounts. In addition, a substantial fraction (at least 20–30%) of all clouds remains undetected in the polar regions during the polar winter season due to the lack of or an inverted temperature contrast between Earth surfaces and clouds. Subsequent cloud top height evaluation took into account the derived information about the cloud detection limits. It was shown that this has fundamental importance for the achieved results. An overall bias of −274 m was achieved compared to a bias of −2762 m when no measures were taken to compensate for cloud detection limitations. Despite this improvement it was concluded that high-level clouds still suffer from substantial height underestimations, while the opposite is true for low-level (boundary layer) clouds. The validation method and the specifically collected satellite dataset with optimal matching in time and space are suggested for a wider use in the future for evaluation of other cloud retrieval methods based on passive satellite imagery.
Distribution of phytoplankton functional types in high-nitrate low-chlorophyll waters in a new diagnostic ecological indicator model
Authors: Palacz A. P. , John M. A. St. , Brewin R. J. W. , Hirata T. , Gregg W. W.
Published: May 2013

Abstract. Modeling and monitoring plankton functional types (PFTs) is challenged by insufficient amount of field measurements to ground-truth both plankton models and bio-optical algorithms. In this study, we combine remote sensing data and a dynamic plankton model to simulate an ecologically-sound spatial and temporal distribution of phyto-PFTs. We apply an innovative ecological indicator approach to modeling PFTs, and focus on resolving the question of diatom-coccolithophore co-existence in the subpolar high-nitrate and low-chlorophyll regions. We choose an artificial neural network as our modeling framework because it has the potential to interpret complex nonlinear interactions governing complex adaptive systems, of which marine ecosystems are a prime example. Using ecological indicators that fulfill the criteria of measurability, sensitivity and specificity, we demonstrate that our diagnostic model correctly interprets some basic ecological rules similar to ones emerging from dynamic models. Our time series highlight a dynamic phyto-PFT community composition in all high latitude areas, and indicate seasonal co-existence of diatoms and coccolithophores. This observation, though consistent with in situ and remote sensing measurements, was so far not captured by state-of-the-art dynamic models which struggle to resolve this "paradox of the plankton". We conclude that an ecological indicator approach is useful for ecological modeling of phytoplankton and potentially higher trophic levels. Finally, we speculate that it could serve as a powerful tool in advancing ecosystem-based management of marine resources.
Tracking atmospheric and riverine terrigenous supplies variability during the last glacial and the Holocene in central Mediterranean
Authors: Bout-Roumazeilles V. , Combourieu-Nebout N. , Desprat S. , Siani G. , Turon J.-L. , Essallami L.
Published: May 2013

Abstract. A multiproxy study – coupling mineralogical, grain size and geochemical approaches – was used to tentatively retrace eolian and fluvial contributions to sedimentation in the Sicilian–Tunisian Strait since the last glacial. The eolian supply is dominant over the whole interval, excepted during the sapropel S1 when riverine contribution apparently became significant. Saharan contribution increased during the Bølling–Allerød, evidencing the persistence of aridity over North Africa although the northern Mediterranean already experienced moister and warmer conditions. The Younger Dryas is marked by proximal dust inputs, highlighting intense regional eolian activity. A southward migration of dust provenance toward Sahel occurred at the onset of the Holocene, likely resulting from a southward position of the Inter Tropical Convergence Zone that was probably associated with a large-scale atmospheric reorganization. Finally, a peculiar high terrigenous flux associated with drastic modifications of the mineralogical and geochemical sediment signature occurred during the sapropel S1, suggesting the propagation of fine particles derived from major floodings of the Nile River – resulting from enhanced rainfall on northeastern Africa – and their transportation across the Sicilian–Tunisian Strait by intermediate water masses.
Thermal management of an unconsolidated shallow urban groundwater body
Authors: Epting J. , Händel F. , Huggenberger P.
Published: May 2013

Abstract. This study presents the development of tools for the sustainable thermal management of a shallow unconsolidated urban groundwater body in the city of Basel (Switzerland). The concept of the investigations is based on (1) a characterization of the present thermal state of the urban groundwater body, and (2) the evaluation of potential mitigation measures for the future thermal management of specific regions within the groundwater body. The investigations focus on thermal processes down-gradient of thermal groundwater use, effects of heated buildings in the subsurface as well as the thermal influence of river–groundwater interaction. Investigation methods include (1) short- and long-term data analysis, (2) high-resolution multilevel groundwater temperature monitoring, as well as (3) 3-D numerical groundwater flow and heat transport modeling and scenario development. The combination of these methods allows for the quantifying of the thermal influences on the investigated urban groundwater body, including the influences of thermal groundwater use and heated subsurface constructions. Subsequently, first implications for management strategies are discussed, including minimizing further groundwater temperature increase, targeting "potential natural" groundwater temperatures for specific aquifer regions and exploiting the thermal potential.
Spatial patterns in timing of the diurnal temperature cycle
Authors: Holmes T. R. H. , Crow W. T. , Hain C.
Published: May 2013

Abstract. This paper investigates the structural difference in timing of the diurnal temperature cycle (DTC) over land resulting from choice of measuring device or model framework. It is shown that the timing can be reliably estimated from temporally sparse observations acquired from a constellation of low Earth orbiting satellites given record lengths of at least three months. Based on a year of data, the spatial patterns of mean DTC timing are compared between Ka-band temperature estimates, geostationary thermal infrared (TIR) temperature estimates and numerical weather prediction model output from the Global Modeling and Assimilation Office (GMAO). It is found that the spatial patterns can be explained by vegetation effects, sensing depth differences and more speculatively the orientation of orographic relief features. In absolute terms, the GMAO model puts the peak of the DTC on average at 12:50 local solar time, 23 min before TIR with a peak temperature at 13:13. Since TIR is the shallowest observation of the land surface, this small difference represents a structural error that possibly affects the models ability to assimilate observations that are closely tied to the DTC. For non-desert areas, the Ka-band observations have only a small delay of about 15 min with the TIR observations which is in agreement with their respective theoretical sensing depth. The results of this comparison provide insights into the structural differences between temperature measurements and models, and can be used as a first step to account for these differences in a coherent way.
Spatial and seasonal variations in evapotranspiration over Canada's landmass
Authors: Wang S. , Yang Y. , Luo Y. , Rivera A.
Published: May 2013

Abstract. A 30 yr (1979–2008) dataset of actual evapotranspiration (ET) at 1 km resolution was generated over Canada's landmass by integrating remote sensing land surface data and gridded climate data using the EALCO model run at 30 min time step. This long-term high resolution dataset was used to characterize the spatiotemporal variations in ET across Canada. The results show that annual ET varied from 600 mm yr−1 over several regions in the south to less than 100 mm yr−1 in the northern arctic. Nationally, ET in summer (i.e., June to August) comprised 65% of the annual total amount. ET in the cold season remained mostly below 10 mm month−1 over the country. Negative monthly ET was obtained over the arctic region in winter, indicating EALCO simulated a larger amount of condensation than ET. Overall, the mean ET over the entire Canadian landmass for the 30 yr was 239 mm yr−1, or 44% of its corresponding precipitation. Comparisons of available ET studies in Canada revealed large uncertainties in ET estimates associated with using different approaches. The scarcity of ET measurements for the diverse ecosystems in Canada remains a significant challenge for reducing the uncertainties; this gap needs to be addressed in future studies to improve capabilities in climate/weather modelling and water resource management.
Spatial-temporal dynamics of chemical composition of surface snow in East Antarctic along the transect Station Progress-Station Vostok
Authors: Khodzher T. V. , Golobokova L. P. , Shibaev Y. A. , Lipenkov V. Y. , Petit J. R.
Published: May 2013

Abstract. This paper presents data on chemical composition of the Antarctic snow sampled during the 53rd Russian Antarctic Expedition (RAE, 2008) along the first tractor traverse (TT) from Station Progress to Station Vostok (East Antarctica). Snow samples were obtained from the cores drilled at 55.3, 253, 337, 369, 403, 441, 480, 519, 560, 618, 819, and 1276 km from Station Progress. Data on horizontal and deep distribution of chemical components in the snow provide evidence of spatial and temporal variations of conditions for the snow cover formation along the transect under study. Sea salt was the main source for chemical composition of snow cover near the ice edge. Concentrations of marine-derived components decreased further inland. A hypothesis was put forward that some ions in the snow cover of the central part of East Antarctica were likely to be of continental origin. Elevated concentrations of sulphate ions of continental origin were recorded in some profiles of the transect at a depth of 130–150 cm which was attributed to buried signals of the Pinatubo volcano eruption (1991).
Network locality: Local knowledge and politics in a network culture
Authors: Gordon Eric
Published: May 2013

The theory of network locality suggests that location continues to matter in a globalized and networked culture. But the conditions under which location produces local knowledge and politics are changing. With the ubiquity of digital networks, the physical location of bodies is coupled with the accessibility of located information. This article explores a theoretical framework for the global reorientation of local politics.
Philosophy Democratized?
Authors: Elvebakk Beate
Published: May 2013

This article compares the individuals categorized as 20th century philosophers in Wikipedia with the selection found in two major edited and widely used online philosophy resources, The Stanford Encyclopaedia of Philosophy (plato.stanford.edu), and the Internet Encyclopedia of Philosophy (www.iep.utm.edu). These are both free online resources, but unlike Wikipedia, they are written and edited by members of the academic community, and thus sanctioned by the established communities. The individuals presented as 20th century philosophers are compared along the parameters of year of birth, gender, and national and disciplinary backgrounds. The results show that although the types of academics listed in Wikipedia are generally similar to those in the other encyclopaedias, their relative youth and their very numbers may still serve to give the user a very different impression on philosophy as a field.
Web 2.0: An argument against convergence
Authors: Allen Matthew
Published: May 2013

Web 2.0 has been a dominant concept in recent discussion and development of Internet applications, businesses and uses. Dating from 2004, the term Web 2.0 is variously understood as new forms of website development and delivery technology, changing uses of the Internet to emphasise sociability over consumption, new understandings of the possible financial exploitation of the web, and more broadly, a new way of thinking about the Internet as a whole. However, Web 2.0 is, conceptually, both more and less than these various understandings and we can only grasp why it has become such a key term in contemporary usage by appreciating two key discursive foundations for this term. Firstly, much Web 2.0 thinking is a re-expression of long-held ideas about the Internet and the web. Secondly, at the particular time when Web 2.0 was made popular, net technology policy makers and financial analysts were primarily enthused by the possibilities of broadband networks for improved and more profitable versions of the well-established businesses of telephony and audio-visual entertainment, and had to some extent consigned novel, web-based services to a lesser role, following the dot.com crash. Thus, as I argue in this paper, Web 2.0 can be understood as a key intervention, from within the dot.com / new media business sector, recovering from the crash, that re-asserts the equal legitimacy of the use of networked computing, over high-speed lines, for computing-oriented activities, and not just video on demand and voice over IP. In short, in the first years of this century, discussions about the future of the Internet had become dominated by arguments for increased broadband access, substantially concerned with providing more traditional video and voice services in new ways. The World Wide Web was seen as relatively unimportant for this purpose, even though it was part of the so-called 'triple play' of voice and data services. At this time, first in the hands of Tim O'Reilly and then from others who took up his position, Web 2.0 became a catchy simple term under which to mount a campaign for the renaissance of the World Wide Web as a quite distinct, yet equally important, form of media and communications. So, Web 2.0 provides evidence that, while there is a convergence of all forms of media and communications towards similar data traffic over the Internet, there remain diverging views over the nature, control and use of the Internet, views that express the degree to which corporate players imagine themselves to be 'media', 'telephony' or 'computing' in primary orientation.
Interactivity is Evil! A critical investigation of Web 2.0
Authors: Jarrett Kylie
Published: May 2013

Central to Web 2.0 is the requirement for interactive systems to enable the participation of users in production and social interaction. Consequently, in order to critically explore the Web 2.0 phenomenon it is important to explore the relationship of interactivity to social power. This study firstly characterises interactivity in these media using Barry's (2001) framework differentiating interactivity from disciplining technologies as defined by Foucault. Contrary to Barry's model though, the analysis goes on to explore how interactivity may indeed function as a disciplining technology within the framework of a neo-liberal political economy.
Loser Generated Content: From Participation to Exploitation
Authors: Petersen Søren Mørk
Published: May 2013

In this article some of the critical aspects of Web 2.0 are mapped in relation to labor and the production of user generated content. For many years the Internet was considered an apt technology for subversion of capitalism by the Italian post-Marxists. What we have witnessed, however, is that the Internet functions as a double-edged sword; the infrastructure does foster democracy, participation, joy, creativity and sometimes creates zones of piracy. But, at the same time, it has become evident how this same infrastructure also enables companies easily to piggyback on user generated content. Different historical and contemporary examples are provided to map how the architecture of participation sometimes turns into an architecture of exploitation.
Online social networking as participatory surveillance
Authors: Albrechtslund Anders
Published: May 2013

In this article, I argue that online social networking is anchored in surveillance practices. This gives us an opportunity to challenge conventional understandings of surveillance that often focus on control and disempowerment. In the context of online social networking, surveillance is something potentially empowering, subjectivity building and even playful — what I call participatory surveillance.
An activity theoretic model for information quality change
Authors: Stvilia Besiki , Gasser Les
Published: May 2013

To manage information quality (IQ) effectively, one needs to know how IQ changes over time, what causes it to change, and whether the changes can be predicted. In this paper we analyze the structure of IQ change in Wikipedia, an open, collaborative general encyclopedia. We found several patterns in Wikipedia’s IQ process trajectories and linked them to article types. Drawing on the results of our analysis, we develop a general model of IQ change that can be used for reasoning about IQ dynamics in many different settings, including traditional databases and information repositories.
Ze Frank and the poetics of Web video
Authors: Newman Michael Z.
Published: May 2013

This article initiates a poetics of Web video by considering the central features of one kind of video on the Web, the amateur videoblog, in terms of its functions, which include various affordances of use, and constraints, which include economics, technology, and viewing conditions. It takes as its central example an American videoblog called The Show With Ze Frank, which ran from 2006-2007, and which drew a passionate community of fans into collaborating in its creation. This article considers amateur Web video as a potentially democratic space for media production, offering an alternative to commercial media that involves ordinary citizens as participants and champions their creativity.
To catch a predator? The MySpace moral panic
Authors: Marwick Alice E
Published: May 2013

This paper discusses moral panics over contemporary technology, or “technopanics.” I use the cyberporn panic of 1996 and the contemporary panic over online predators and MySpace to demonstrate links between media coverage and content legislation. In both cases, Internet content legislation is directly linked to media-fueled moral panics that concern uses of technology deemed harmful to children. This is of particular interest right now as a new internet content bill, the Deleting Online Predators Act (DOPA), is being debated in Congress. The technopanic over “online predators” is remarkably similar to the cyberporn panic; both are fueled by media coverage, both rely on the idea of harm to children as the justification for internet content restriction, and both have resulted in carefully crafted legislation to circumvent First Amendment concerns. Research demonstrates that legislation proposed (or passed) to curb these problems is an extraordinary response; it is misguided and in many cases masks the underlying problem.
Moving the crowd at iStockphoto: The composition of the crowd and motivations for participation in a crowdsourcing application
Authors: Brabham Daren C.
Published: May 2013

Crowdsourcing is an online, distributed problem solving and production model already in use by for-profit organizations such as Threadless, iStockphoto, and InnoCentive. Speculation in Weblogs and wisdom of crowds theory assumes a diverse crowd engaged in crowdsourcing labor. Furthermore, and as crowdsourcing is in some ways similar to open source software production, prior research suggests that individuals in the crowd likely participate in crowdsourcing ventures to gain peer recognition and to develop creative skills. The present study tests these assumptions in the crowdsourcing community at iStockphoto. An online survey obtained 651 responses from iStockers to demographic and motivations questions. Results indicate that the desire to make money, develop individual skills, and to have fun were the strongest motivators for participation at iStockphoto, and that the crowd at iStockphoto is quite homogenous and elite. These data have implications for future research into crowdsourcing, particularly regarding notions of professionalism and investment in online communities.
Visual comparison of search results: A censorship case study
Authors: Meiss Mark , Menczer Filippo
Published: May 2013

Understanding the qualitative differences between the sets of results from different search engines can be a difficult task. How many links must you follow from each list before you can reach a conclusion? We describe a user interface that allows users to quickly identify the most significant differences in content between two lists of Web pages. We have implemented this interface in CenSEARCHip, a system for comparing the effects of censorship policies on search engines.
The Internet as a tool for democracy? A survey of non-profit Internet decision-makers and Web users
Authors: Kenix Linda Jean
Published: May 2013

Although research has urged scholars and practitioners to develop the Internet as a democratic tool, little research has examined how users actually use the Internet and how the Internet is conceptualized by those who create its content – particularly in the non-profit sector where questions of democracy, interconnected communication and information gathering are often central to survival. This research surveys 688 people associated with non-profit organizations in the United States to better understand their perceptions and uses of the Internet as a tool for social change.
Rights and Responsibilities Online: A Paradox for Our Times
Authors: Fanton Jonathan F.
Published: May 2013

The Internet is hailed as a democratic force freeing people from inherited orthodoxy and hierarchy. Yet some observers and visitors of virtual worlds decry the absence of the individual rights we have come to expect in a democratic society. This paradox of the Internet’s democratic promise and lack of democratic protections raises vexing legal issues. What are the rights and responsibilities of owners and users of digital media, profilers on social network sites, game players and participants in virtual worlds of all types? These issues must be addressed if the power of community is to be realized in a just and sustainable way.
Ashes2Art: Collaboration and Community in the Humanities
Authors: Flaten Arne , Gill Alyson
Published: May 2013

Ashes2Art is the integration of research and pedagogy in digital

reconstructions of ancient monuments, data retrieval matrices, open source

software and intercollegiate collaboration. The program's immediate focus

is 4th century BCE Delphi, Greece. A joint effort among faculty and

undergraduate students at Coastal Carolina University and Arkansas State

University, Ashes2Art combines art history, archaeology, Web design, digital

modeling, panoramic photography, animation, video and site-specific travel.