bluuebunny/crossref_metadata_2025 huggingface dataset:
Determinants of Successful Outcome in Couples Consulting Infertility Clinic—Postgraduate Institute of Medical Education and Research, Chandigarh, India: A Record-based Analysis
Authors: Singh Amarjeet , Dhaliwal Lakhbir K , Sinha Smita
Published: December 2014

Objective

To identify the factors determining the successful outcome in infertile cases reporting to infertility clinic at a tertiary hospital, Chandigarh, India.

Design

Retrospective record based analysis.

Setting and records

The records of all 2049 patients registered with infertility clinic over the period of 5 years from January 2002 to December 2006 were included for the analysis. Data regarding sociodemographic details, personal history, menstrual history of female, obstetrics history, Past medical and surgical history of couple; gynecological disorder, husband's sexual disorder, details of investigation and treatment received by couple and its outcome were retrieved from the records. Logistic regression model was used to reveal the most important determinants of successful outcome in infertile couples.

Results

The conception rate was twice among younger women (≤ 30 years) compared to older than 30 years. The couples with shorter duration of infertility (≤ 3 years) were more than twice likely to conceive compared to those with duration longer than 3 years. Normal semen analysis findings in men and absence of any demonstrable cause of infertility in women were also found to be favorable predictor of treatment outcome among infertile couples.

Conclusion

Our finding can help couples and clinicians in charting out the workup and counseling plan for individual couples. However, further studies are needed to validate the model developed in study.

How to cite this article

Dhaliwal LK, Singh A, Sinha S. Determinants of Successful Outcome in Couples Consulting Infertility Clinic—Postgraduate Institute of Medical Education and Research, Chandigarh, India: A Record-based Analysis. J Postgrad Med Edu Res 2014;48(4):164-170.
Sexual and Ethnic Differences in Facial Anthropometry of Northwest Indians
Authors: Aggarwal Anjali , Sahni Daisy , LNU Sanjeev , LNU Harjeet , Jaggi Shallu
Published: December 2014

Aim

To determine sexual, age related and ethnic differences in somatometric measurements of northwest Indian (NWI) and to elucidate relation between these measurements.

Context

This information will help surgeons during the planning stages of facial plastic surgery and forensic experts in reconstructing face for identification of homicide victims and missing persons.

Materials and methods

The study included 15 somatometric measurements on 173 males and 127 females healthy subjects from 18 to 70 years.

Results

Statistically significant sexual differences were observed in parameters of head, face, nose and biocular breadth and interpupillary distance. No consistent age related patterns were found except in eye and nasal regions in males. The relation between different parameters showed almost equal length and breadth of face. In majority of subjects, bigonial breadth was smaller than minimum frontal breadth but larger than face breadth. Interocular breadth was smaller than ocular and nasal breadth while nasal height and length were larger than lower face height. Ethnic comparisons render smaller values in most of the parameters.

How to cite this article

Sahni D, Sanjeev, Harjeet, Jaggi S, Aggarwal A. Sexual and Ethnic Differences in Facial Anthropometry of Northwest Indians. J Postgrad Med Edu Res 2014; 48(4):171-182.
Tobacco Habits among the 8 to 15 Years School Children of Rural Haryana
Authors: Goyal Ashima , Rattan Vidya , Mohanty Utkal
Published: December 2014

Aim

The present cross-sectional study was undertaken to determine the prevalence and age at initiation of tobacco use among school children in rural areas of Haryana.

Materials and methods

A cluster sample design was used to produce a representative sample of schools from Panchkula and Ambala district. All students were included from the selected schools and information regarding tobacco use was collected from students of class 3 to 10 (8-15 years) through a self-administered questionnaire.

Results

A total of 3526 students with average age of 12.2 ± 2.3 years were screened for tobacco use. About 182 (5.1%) school children were found to be ever users of tobacco and 79 (2.2%) were current tobacco users in any form. Peer pressure was found to be the most common cause of initiating tobacco use by the students.

Conclusion

Prevalence of tobacco use among the school children of rural Haryana is lower than that reported in urban areas by Global Youth Tobacco Survey (GYTS). However, the downward shift of the age at initiation (<10 years) is a matter of grave concern, which needs to be tackled by creating suitable school environment through health promotion and strengthening anti tobacco laws.

How to cite this article

Rattan V, Mohanty U, Goyal A. Tobacco Habits among the 8 to 15 Years School Children of Rural Haryana. J Postgrad Med Edu Res 2014;48(4):183-185.
Act without Fear or Favor: Ethics in Dentistry
Authors: Ramdurg Vijaylaxmi , Ramdurg Praveenkumar
Published: December 2014

The dental profession holds a special position of trust within society. As a consequence, society affords the profession certain privileges that are not available to members of the public at large. In return, the profession makes a commitment to society that its members will adhere to high ethical standards of conduct. A philosophical study of moral issues of right and wrong is called ethics, and deals with the moral duties of the professional dentists toward their patient, society and professional colleagues. The dentists have a duty to conduct their professional life, in accordance with the fundamental principles of ethics. This article reviews the evolution and philosophy of ethics, theories of ethics and the fundamental principles of ethics that the dentist should follow.

How to cite this article

Ramdurg V, Ramdurg P. Act without Fear or Favor: Ethics in Dentistry. J Postgrad Med Edu Res 2014;48(4):186-189.
Peculiar NCCT Brain Picture in Polycythemia
Authors: Bhoil Rohit
Published: December 2014

This is a case of polycythemia presenting with headache and showing hyperdense cerebral vasculature and dural sinuses thereby simulating the appearance of a contrast enhanced computed tomography (CT) on plain films.

How to cite this article

Bhoil R. Peculiar Ncct Brain Picture in Polycythemia. J Postgrad Med Edu Res 2014;48(4):197-198.
Idiopathic Pulmonary Hemosiderosis in an Adult with Unusual Radiologic Features
Authors: Kasilingam Sangeeth Kumar , Prashanth Shylaja , Govindagoudar Manjunath B , Devaramani Bheemaraya , Swamygowda Chaitra Channarayapatna
Published: December 2014

Idiopathic pulmonary hemosiderosis is an exceptionally rare cause of diffuse alveolar hemorrhage that occurs primarily in infants and children. Few cases are reported in adults. Patients usually present with recurrent episodes of hemoptysis, fatigue breathlessness and severe anemia with asymptomatic periods in between. Our patient, who was diagnosed with idiopathic pulmonary hemosiderosis demonstrated diffuse ground glass opacity, focal centrilobular emphysema and multiple sub pleural cysts and few parenchymal cysts during acute episode of hemoptysis. Unusual findings in our case were sub pleural cysts, parenchymal cysts and focal centrilobular emphysema which was not documented in any case reports of idiopathic pulmonary hemosiderosis cases to that of our knowledge.

How to cite this article

Kasilingam SK, Prashanth S, Govindagoudar MB, Devaramani B, Swamygowda CC. Idiopathic Pulmonary Hemosiderosis in an Adult with Unusual Radiologic Features. J Postgrad Med Edu Res 2014;48(4):199-200.
Retropharyngeal Course of Right Internal Carotid Artery
Authors: Khandelwal Niranjan , Singhal Manphool , Prabhakar Nidhi , Rohit Manoj Kumar
Published: December 2014

A case of retropharyngeal course of right internal carotid artery diagnosed on CT angiography is presented along with its clinical relevance.

How to cite this article

Singhal M, Prabhakar N, Rohit MK, Khandelwal N. Retropharyngeal Course of Right Internal Carotid Artery. J Postgrad Med Edu Res 2014;48(4):201-202.
Automatic cloud top height determination in mountainous areas using a cost-effective time-lapse camera system
Authors: Schulz H. M. , Chang S.-C. , Thies B. , Bendix J.
Published: December 2014

Abstract. A new method is presented for the determination of cloud top heights using the footage of a time-lapse camera that is placed above a frequently occurring cloud layer in a mountain valley. Contact points between cloud tops and underlying terrain are automatically detected in the camera image based on differences in the brightness, texture and movement of cloudy and non-cloudy areas. The height of the detected cloud top positions is determined by comparison with a digital elevation model projected to the view of the camera. The technique has been validated using data about the cloud immersion of a second camera as well as via visual assessment. The validation shows a high detection quality, especially regarding the requirements for the validation of satellite cloud top retrieval algorithms.
Flux variations and vertical distributions of microzooplankton (Radiolaria) in the western Arctic Ocean: environmental indices in a warming Arctic
Authors: Ikenoue T. , Bjørklund K. R. , Kruglikova S. B. , Onodera J. , Kimoto K. , Harada N.
Published: December 2014

Abstract. The vertical distribution of radiolarians was investigated using a vertical multiple plankton sampler (100–0, 250–100, 500–250 and 1000–500 m water depths, 62 μm mesh size) at the Northwind Abyssal Plain and southwestern Canada Basin in September 2013. To investigate seasonal variations in the flux of radiolarians in relation to sea-ice and water masses, time series sediment trap system was moored at Station NAP (75°00' N, 162°00' W, bottom depth 1975 m) in the western Arctic Ocean during October 2010–September 2012. We showed characteristics of fourteen abundant radiolarian taxa related to the vertical hydrographic structure in the western Arctic Ocean. We found the Ceratocyrtis histricosus, a warm Atlantic water species, in net samples, indicating that it has extended its habitat into the Pacific Winter Water. The radiolarian flux was comparable to that in the North Pacific Oceans. Amphimelissa setosa was dominant during the open water and the beginning and the end of ice cover seasons with well-grown ice algae, ice fauna and with alternation of stable water masses and deep vertical mixing. During the sea-ice cover season, however, oligotrophic and cold-water tolerant Actinommidae was dominant and the productivity of radiolaria was lower and its species diversity was greater, which might be associated with the seasonal increase of solar radiation that induce the growth of algae on the ice and the other phytoplankton species under the sea-ice. These indicated that the dynamics of sea-ice was a major factor affecting the productivity, distribution, and composition of radiolarian fauna.
Technical Note: Probabilistically constraining proxy age–depth models within a Bayesian hierarchical reconstruction model
Authors: Werner J. P. , Tingley M. P.
Published: December 2014

Abstract. Reconstructions of late-Holocene climate rely heavily upon proxies that are assumed to be accurately dated by layer counting, such as measurement on tree rings, ice cores, and varved lake sediments. Considerable advances may be achievable if time uncertain proxies could be included within these multiproxy reconstructions, and if time uncertainties were recognized and correctly modeled for proxies commonly treated as free of age model errors. Current approaches to accounting for time uncertainty are generally limited to repeating the reconstruction using each of an ensemble of age models, thereby inflating the final estimated uncertainty – in effect, each possible age model is given equal weighting. Uncertainties can be reduced by exploiting the inferred space–time covariance structure of the climate to re-weight the possible age models. Here we demonstrate how Bayesian Hierarchical climate reconstruction models can be augmented to account for time uncertain proxies. Critically, while a priori all age models are given equal probability of being correct, the probabilities associated with the age models are formally updated within the Bayesian framework, thereby reducing uncertainties. Numerical experiments show that updating the age-model probabilities decreases uncertainty in the climate reconstruction, as compared with the current de-facto standard of sampling over all age models, provided there is sufficient information from other data sources in the region of the time-uncertain proxy. This approach can readily be generalized to non-layer counted proxies, such as those derived from marine sediments.
Contrasting roles of interception and transpiration in the hydrological cycle – Part 1: Temporal characteristics over land
Authors: Wang-Erlandsson L. , van der Ent R. J. , Gordon L. J. , Savenije H. H. G.
Published: December 2014

Abstract. Moisture recycling, the contribution of terrestrial evaporation to precipitation, has important implications for both water and land management. Although terrestrial evaporation consists of different fluxes (i.e. transpiration, vegetation interception, floor interception, soil moisture evaporation, and open-water evaporation), moisture recycling (terrestrial evaporation–precipitation feedback) studies have up to now only analysed their combined total. This paper constitutes the first of two companion papers that investigate the characteristics and roles of different evaporation fluxes for land–atmosphere interactions. Here, we investigate the temporal characteristics of partitioned evaporation on land and present STEAM (Simple Terrestrial Evaporation to Atmosphere Model) – a hydrological land-surface model developed to provide inputs to moisture tracking. STEAM estimates a mean global terrestrial evaporation of 73 900 km3 year-1, of which 59% is transpiration. Despite a relatively simple model structure, validation shows that STEAM produces realistic evaporative partitioning and hydrological fluxes that compare well with other global estimates over different locations, seasons, and land-use types. Using STEAM output, we show that the terrestrial residence timescale of transpiration (days to months) has larger inter-seasonal variation and is substantially longer than that of interception (hours). Most transpiration occurs several hours or days after a rain event, whereas interception is immediate. In agreement with previous research, our simulations suggest that the vegetation's ability to transpire by retaining and accessing soil moisture at greater depth is critical for sustained evaporation during the dry season. We conclude that the differences in temporal characteristics between evaporation fluxes are substantial and reasonably can cause differences in moisture recycling, which is investigated more in the companion paper (van der Ent et al., 2014, hereafter Part 2).
Contrasting roles of interception and transpiration in the hydrological cycle – Part 2: Moisture recycling
Authors: van der Ent R. J. , Wang-Erlandsson L. , Keys P. W. , Savenije H. H. G.
Published: December 2014

Abstract. The contribution of land evaporation to local and remote precipitation (i.e. moisture recycling) is of significant importance to sustain water resources and ecosystems. But how important are different evaporation components in sustaining precipitation? This is the first paper to present moisture recycling metrics for partitioned evaporation. In the companion paper Wang-Erlandsson et al. (2014) (hereafter Part 1), evaporation was partitioned into vegetation interception, floor interception, soil moisture evaporation and open-water evaporation (constituting the direct, purely physical fluxes, largely dominated by interception), and transpiration (delayed, biophysical flux). Here, we track these components forward as well as backward in time. We also include age tracers to study the atmospheric residence times of these evaporation components. We present a new image of the global hydrological cycle that includes quantification of partitioned evaporation and moisture recycling as well as the atmospheric residence times of all fluxes. We demonstrate that evaporated interception is more likely to return as precipitation on land than transpired water. On average, direct evaporation (essentially interception) is found to have an atmospheric residence time of 8 days, while transpiration typically resides for 9 days in the atmosphere. The process scale over which evaporation recycles is more local for interception compared to transpiration; thus interception generally precipitates closer to its evaporative source than transpiration, which is particularly pronounced outside the tropics. We conclude that interception mainly works as an intensifier of the local hydrological cycle during wet spells and wet seasons. On the other hand, transpiration remains active during dry spells and dry seasons and is transported over much larger distances downwind, where it can act as a significant source of moisture. Thus, as various land-use types can differ considerably in their partitioning between interception and transpiration, our results stress that land-use changes (e.g. forest-to-cropland conversion) do not only affect the magnitude of moisture recycling, but could also influence the moisture recycling patterns and lead to a redistribution of water resources. As such, this research highlights that land-use changes can have complex effects on the atmospheric branch of the hydrological cycle.
Optimizing cropland cover for stable food production in Sub-Saharan Africa using simulated yield and Modern Portfolio Theory
Authors: Bodin P. , Olin S. , Pugh T. A. M. , Arneth A.
Published: December 2014

Abstract. Food security can be defined as stable access to food of good nutritional quality. In Sub Saharan Africa access to food is strongly linked to local food production and the capacity to generate enough calories to sustain the local population. Therefore it is important in these regions to generate not only sufficiently high yields but also to reduce interannual variability in food production. Traditionally, climate impact simulation studies have focused on factors that underlie maximum productivity ignoring the variability in yield. By using Modern Portfolio Theory, a method stemming from economics, we here calculate optimum current and future crop selection that maintain current yield while minimizing variance, vs. maintaining variance while maximizing yield. Based on simulated yield using the LPJ-GUESS dynamic vegetation model, the results show that current cropland distribution for many crops is close to these optimum distributions. Even so, the optimizations displayed substantial potential to either increase food production and/or to decrease its variance regionally. Our approach can also be seen as a method to create future scenarios for the sown areas of crops in regions where local food production is important for food security.
Sea ice in the Baltic Sea – revisiting BASIS ice, a historical data set covering the period 1960/1961–1978/1979
Authors: Löptien U. , Dietze H.
Published: December 2014

Abstract. The Baltic Sea is a seasonally ice-covered, marginal sea in central northern Europe. It is an essential waterway connecting highly industrialised countries. Because ship traffic is intermittently hindered by sea ice, the local weather services have been monitoring sea ice conditions for decades. In the present study we revisit a historical monitoring data set, covering the winters 1960/1961 to 1978/1979. This data set, dubbed Data Bank for Baltic Sea Ice and Sea Surface Temperatures (BASIS) ice, is based on hand-drawn maps that were collected and then digitised in 1981 in a joint project of the Finnish Institute of Marine Research (today the Finnish Meteorological Institute (FMI)) and the Swedish Meteorological and Hydrological Institute (SMHI). BASIS ice was designed for storage on punch cards and all ice information is encoded by five digits. This makes the data hard to access. Here we present a post-processed product based on the original five-digit code. Specifically, we convert to standard ice quantities (including information on ice types), which we distribute in the current and free Network Common Data Format (NetCDF). Our post-processed data set will help to assess numerical ice models and provide easy-to-access unique historical reference material for sea ice in the Baltic Sea. In addition we provide statistics showcasing the data quality. The website http://www.baltic-ocean.org hosts the post-processed data and the conversion code. The data are also archived at the Data Publisher for Earth & Environmental Science, PANGAEA (doi:10.1594/PANGAEA.832353).
Using expert knowledge to increase realism in environmental system models can dramatically reduce the need for calibration
Authors: Gharari S. , Hrachowitz M. , Fenicia F. , Gao H. , Savenije H. H. G.
Published: December 2014

Abstract. Conceptual environmental system models, such as rainfall runoff models, generally rely on calibration for parameter identification. Increasing complexity of this type of models for better representation of hydrological process heterogeneity, typically makes parameter identification more difficult. Although various, potentially valuable, approaches for better parameter estimation have been developed, strategies to impose general conceptual understanding of how a catchment works into the process of parameter estimation has not been fully explored. In this study we assess the effects of imposing semi-quantitative, relational inequality constraints, based on expert-knowledge, for model development and parameter specification, efficiently exploiting the complexity of a semi-distributed model formulation. Making use of a topography driven rainfall-runoff modeling (FLEX-TOPO) approach, a catchment was delineated into three functional units, i.e., wetland, hillslope and plateau. Ranging from simple to complex, three model setups, FLEXA, FLEXB and FLEXC were developed based on these functional units, where FLEXA is a lumped representation of the study catchment, and the semi-distributed formulations FLEXB and FLEXC progressively introduce more complexity. In spite of increased complexity, FLEXB and FLEXC allow modelers to compare parameters, as well as states and fluxes, of their different functional units to each other, allowing the formulation of constraints that limit the feasible parameter space. We show that by allowing for more landscape-related process heterogeneity in a model, e.g., FLEXC, the performance increases even without traditional calibration. The additional introduction of relational constraints further improved the performance of these models.
Comparison of rainfall estimations by TRMM 3B42, MPEG and CFSR with ground-observed data for the Lake Tana basin in Ethiopia
Authors: Worqlul A. W. , Maathuis B. , Adem A. A. , Demissie S. S. , Langan S. , Steenhuis T. S.
Published: December 2014

Abstract. Planning for drought relief and floods in developing countries is greatly hampered by the lack of a sufficiently dense network of weather stations measuring precipitation. In this paper, we test the utility of three satellite products to augment the ground-based precipitation measurement to provide improved spatial estimates of rainfall. The three products are the Tropical Rainfall Measuring Mission (TRMM) product (3B42), Multi-Sensor Precipitation Estimate–Geostationary (MPEG) and the Climate Forecast System Reanalysis (CFSR). The accuracy of the three products is tested in the Lake Tana basin in Ethiopia, where 38 weather stations were available in 2010 with a full record of daily precipitation amounts. Daily gridded satellite-based rainfall estimates were compared to (1) point-observed ground rainfall and (2) areal rainfall in the major river sub-basins of Lake Tana. The result shows that the MPEG and CFSR satellites provided the most accurate rainfall estimates. On average, for 38 stations, 78 and 86% of the observed rainfall variation is explained by MPEG and CFSR data, respectively, while TRMM explained only 17% of the variation. Similarly, the areal comparison indicated a better performance for both MPEG and CFSR data in capturing the pattern and amount of rainfall. MPEG and CFSR also have a lower root mean square error (RMSE) compared to the TRMM 3B42 satellite rainfall. The bias indicated that TRMM 3B42 was, on average, unbiased, whereas MPEG consistently underestimated the observed rainfall. CFSR often produced large overestimates.
Quantifying river form variations in the Mississippi Basin using remotely sensed imagery
Authors: Miller Z. F. , Pavelsky T. M. , Allen G. H.
Published: December 2014

Abstract. Geographic variations in river form are often estimated using the framework of downstream hydraulic geometry (DHG), which links spatial changes in discharge to channel width, depth, and velocity through power-law models. These empirical relationships are developed from limited in situ data and do not capture the full variability in channel form. Here, we present a data set of 1.2 ×106 river widths in the Mississippi Basin measured from the Landsat-derived National Land Cover Dataset that characterizes width variability observationally. We construct DHG for the Mississippi drainage by linking digital elevation model (DEM)-estimated discharge values to each width measurement. Well-developed DHG exists over the entire Mississippi Basin, though individual sub-basins vary substantially from existing width–discharge scaling. Comparison of depth predictions from traditional depth–discharge relationships with a new model incorporating width into the DHG framework shows that including width improves depth estimates by, on average, 24%. Results suggest that channel geometry derived from remotely sensed imagery better characterizes variability in river form than do estimates based on DHG.
Notes on the estimation of resistance to flow during flood wave propagation
Authors: Mrokowska M. M. , Rowiński P. M. , Kalinowska M. B.
Published: December 2014

Abstract. The paper discusses methods of expressing and evaluating resistance to flow in an unsteady flow. Following meaningful trends in hydrological sciences, the paper suggests abandoning, where possible, resistance coefficients in favour of physically based variables such as shear stress and friction velocity. Consequently, an acknowledged method of friction velocity evaluation based on the relations derived from flow equations is examined. The paper presents both a theoretical discussion of various aspects of friction velocity evaluation and the application of the method to field data originating from artificial dam-break flood waves in a small lowland river. As the method is prone to many errors due to the scarcity and the uncertainty of measurement data, the aim of the paper is to provide suggestions on how to apply the method to enhance the correctness of the results. The main steps in applying the method include consideration of the shape of the channel, the type of wave, the method of evaluating the gradient of the flow depth, and the assessment of the uncertainty of the result. Friction velocity and the Manning coefficient are compared in terms of resistance to flow variability during flood wave propagation. It is concluded that the Manning coefficient may be a misleading indicator of the magnitude of resistance in unsteady flow, and to be inferior to physically based variables in such cases.
Moraine-dammed lake failures in Patagonia and assessment of outburst susceptibility in the Baker Basin
Authors: Iribarren Anacona P. , Norton K.P. , Mackintosh A.
Published: December 2014

Abstract. Glacier retreat since the Little Ice Age has resulted in the development or expansion of hundreds of glacial lakes in Patagonia. Some of these lakes have produced large (≥ 106 m3) Glacial Lake Outburst Floods (GLOFs) damaging inhabited areas. GLOF hazard studies in Patagonia have been mainly based on the analysis of short-term series (≤ 50 years) of flood data and until now no attempt has been made to identify the relative susceptibility of lakes to failure. Power schemes and associated infrastructure are planned for Patagonian basins that have historically been affected by GLOFs, and we now require a thorough understanding of the characteristics of dangerous lakes in order to assist with hazard assessment and planning. In this paper, the conditioning factors of 16 outbursts from moraine-dammed lakes in Patagonia were analysed. These data were used to develop a classification scheme designed to assess outburst susceptibility, based on image classification techniques, flow routine algorithms and the Analytical Hierarchy Process. This scheme was applied to the Baker Basin, Chile, where at least seven moraine-dammed lakes have failed in historic time. We identified 386 moraine-dammed lakes in the Baker Basin of which 28 were classified with high or very high outburst susceptibility. Commonly, lakes with high outburst susceptibility are in contact with glaciers and have moderate (> 8°) to steep (> 15°) dam outlet slopes, akin to failed lakes in Patagonia. The proposed classification scheme is suitable for first-order GLOF hazard assessments in this region. However, rapidly changing glaciers in Patagonia make detailed analysis and monitoring of hazardous lakes and glaciated areas upstream from inhabited areas or critical infrastructure necessary, in order to better prepare for hazards emerging from an evolving cryosphere.
Hydrochemical characteristics of the hot spring waters in the Kangding district related to the Lushan MS 7.0 earthquake in Sichuan, China
Authors: Chen Z. , Zhou X. , Du J. , Xie C. , Liu L. , Li Y. , Yi L. , Liu H. , Cui Y.
Published: December 2014

Abstract. Hydrogeochemistry of 10 hot springs in the Kangding district was investigated by analyzing cation and anion concentrations of the spring waters. The water samples were collected within 5 days after the Lushan earthquake. The spring waters are classified into 7 chemical types based on the hydrochemical compositions. Comparison with the hydrochemical data before the Lushan earthquake, concentrations of Ca2+, HCO3− and TDS of the waters from the Guanding, Erdaoqiao, Gonghe, Erhaoying, Tianwanhe and Caoke springs evidently increased, which resulted from enhancing interaction between deep-earth fluids and carbonate rocks by the increment of dissolved CO2 in the groundwater. Concentrations of Na+, Cl− and SO42− of the waters from the Guanding, zheduotang, Xinxing and Gonghe springs were decreased, indicating dilution of precipitation water. Concentrations of Na+ and SO42− of the Erhaoying spring water increased, which may be attributed to the more supplement of fluids enriched in sulfur. The results indicate that hydrochemical components of spring water can be used as an effective indicator for earthquakes.
Benjamin–Feir instability of waves in the presence of current
Authors: Shugan I. V. , Hwung H. H. , Yang R. Y.
Published: December 2014

Abstract. The development of Benjamin–Feir instability of Stokes waves in the presence of variable current is presented. We employ a model of a resonance system having three coexisting nonlinear waves and nonuniform current. The model is free from the narrow-band approximation for surface waves and relatively weak adverse current. The modulation instability of Stokes waves in nonuniform moving media has special properties. Interaction with countercurrent accelerates the growth of sideband modes on a short spatial scale. An increase in initial wave steepness intensifies the wave energy exchange accompanied by wave breaking dissipation, results in asymmetry of sideband modes and a frequency downshift with an energy transfer jump to the lower sideband mode, and depresses the higher sideband and carrier wave. Nonlinear waves may even overpass the blocking barrier produced by strong adverse current. The frequency downshift of the energy peak is permanent and the system does not revert to its initial state. We find reasonable correspondence between the results of model simulations and available experimental results for wave interaction with blocking opposing current. Large transient or freak waves with amplitude and steepness several times those of normal waves may form during temporal nonlinear focusing of the resonant waves accompanied by energy income from sufficiently strong opposing current. We employ the resonance model for the estimation of the maximum amplification of wave amplitudes as a function of gradually increasing opposing current and compare the result obtained with recently published experimental results and modeling results obtained with the nonlinear Schrödinger equation.
Evaluation of empirical mode decomposition for quantifying multi-decadal variations in sea level records
Authors: Chambers D. P.
Published: December 2014

Abstract. The ability of empirical mode decomposition (EMD) to extract multidecadal variability from sea level records is tested using three simulations: one based on a series of purely sinusoidal modes, one based on scaled climate indices of El Niño and the Pacific Decadal Oscillation (PDO), and the final one including a single month with an extreme sea level event. All simulations include random noise of similar variance to high-frequency variability in the San Francisco tide gauge record. The intrinsic mode functions (IMFs) computed using EMD were compared to the prescribed oscillations. In all cases, the longest-period modes are significantly distorted, with incorrect amplitudes and phases. This affects the estimated acceleration computed from the longest periodic IMF. In these simulations, the acceleration was underestimated in the case with purely sinusoidal modes, and overestimated by nearly 100% in the case with prescribed climate modes. Additionally, in all cases, extra low-frequency modes uncorrelated with the prescribed variability are found. These experiments suggest that using EMD to identify multidecadal variability and accelerations in sea level records should be used with caution.
The transient variation of the complexes of the low latitude ionosphere within the equatorial ionization anomaly region of Nigeria
Authors: Rabiu A. B. , Ogunsua B. O. , Fuwape I. A. , Laoye J. A.
Published: December 2014

Abstract. The quest to find an index for proper characterization and description of the dynamical response of the ionosphere to external influences and its various internal irregularities has led to the study of the day to day variations of the chaoticity and dynamical complexity of the ionosphere. This study was conducted using Global Positioning System (GPS) Total Electron Content (TEC) time series, measured in the year 2011, from 5 GPS receiver stations in Nigeria which lies within the Equatorial Ionization Anomaly region. The nonlinear aspect of the TEC time series were obtained by detrending the data. The detrended TEC time series were subjected to various analyses for phase space reconstruction and to obtain the values of chaotic quantifiers which are Lyapunov exponents LE, correlation dimension, and Tsallis entropy for the study of dynamical complexity. The results show positive Lyapunov exponents for all days which indicate chaoticity of the ionosphere with no definite pattern for both quiet and disturbed days. However values of LE were lower for the storm period compared to its nearest relative quiet periods for all the stations. Considering all the days of the year the daily/transient variations show no definite pattern for each month but day to day values of Lyapunov exponent for the entire year show a wavelike semiannual variation pattern with lower values around March, April, September and October, a change in pattern which demonstrates the self-organized critical phenomenon of the system. This can be seen from the correlation dimension with values between 2.7 and 3.2 with lower values occurring mostly during storm periods demonstrating a phase transition from higher dimension during the quiet periods to lower dimension during storms for most of the stations. The values of Tsallis entropy show similar variation pattern with that of Lyapunov exponent with a lot of agreement in their comparison, with all computed values of Lyapunov exponent correlating with values of Tsallis entropy within the range of 0.79 to 0.82. These results show that Lyapunov quantifiers can be used together as indices in the study of the variations of the dynamical complexity of the ionosphere. The presence of chaos and high variations in the dynamical complexity, even at quiet periods in the ionosphere may be due to the internal dynamics and inherent irregularities of the ionosphere which exhibit non-linear properties. However, this inherent dynamics may be complicated by external factors like geomagnetic storms. This may be the main reason for the drop in the values of Lyapunov exponent and Tsallis entropy during storms. The results also show a strong interplay between determinism and stochasticity, as the ionosphere shows its response to changes in solar activities and in its internal dynamics. The dynamical behavior of the ionosphere throughout the year as described by these quantifiers, were discussed in this work.
Study of a temperature gradient metamorphism of snow from 3-D images: time evolution of microstructures, physical properties and their associated anisotropy
Authors: Calonne N. , Flin F. , Geindreau C. , Lesaffre B. , Rolland du Roscoat S.
Published: December 2014

Abstract. We carried out a study to monitor the time evolution of microstructural and physical properties of snow during temperature gradient metamorphism: a snow slab was subjected to a constant temperature gradient in the vertical direction for 3 weeks in a cold room, and regularly sampled in order to obtain a series of three-dimensional (3-D) images using X-ray microtomography. A large set of properties was then computed from this series of 3-D images: density, specific surface area, correlation lengths, mean and Gaussian curvature distributions, air and ice tortuosities, effective thermal conductivity, and intrinsic permeability. Whenever possible, specific attention was paid to assess these properties along the vertical and horizontal directions, and an anisotropy coefficient defined as the ratio of the vertical over the horizontal values was deduced. The time evolution of these properties, as well as their anisotropy coefficients, was investigated, showing the development of a strong anisotropic behavior during the experiment. Most of the computed physical properties of snow were then compared with two analytical estimates (self-consistent estimates and dilute beds of spheroids) based on the snow density, and the size and anisotropy of the microstructure through the correlation lengths. These models, which require only basic microstructural information, offer rather good estimates of the properties and anisotropy coefficients for our experiment without any fitting parameters. Our results highlight the interplay between the microstructure and physical properties, showing that the physical properties of snow subjected to a temperature gradient cannot be described accurately using only isotropic parameters such as the density and require more refined information. Furthermore, this study constitutes a detailed database on the evolution of snow properties under a temperature gradient, which can be used as a guideline and a validation tool for snow metamorphism models at the micro- or macroscale.
Challenging the commodification of public spheres: The hacker work ethic in a free media lab
Authors: Corbett Steven
Published: December 2014

This paper explores the hacker work ethic in a case study of Access Space, a free media lab in Sheffield, United Kingdom, which provides free access to information and communication technologies (ICTs). It is suggested that the hacker work ethic allows participants at Access Space to become socially and digitally included in an empowering way. This aspect of ICT culture is explored in the context of social and technological changes from a public sphere perspective (Habermas, 1989). Access Space is described as part of a hacker counter-public sphere that challenges the dominant trend towards the commodification of ICTs by engaging the principles of the hacker work ethic in social practice. With a move towards informationalism as the ideology of the techno-capitalist age (Castells, 1996; Kellner, 1989), adopting the hacker work ethic in wider social practice may promote empowerment, social and digital inclusion, and critical engagement with ICTs and wider society.
Pricey privacy: Framing the economy of information in the digital age
Authors: Fornaciari Federica
Published: December 2014

As new information technologies become ubiquitous, individuals are often prompted rethinking disclosure. Available media narratives may influence one’s understanding of the benefits and costs related to sharing personal information. This study, guided by frame theory, undertakes a Critical Discourse Analysis (CDA) of media discourse developed to discuss the privacy concerns related to the corporate collection and trade of personal information. The aim is to investigate the frames — the central organizing ideas — used in the media to discuss such an important aspect of the economics of personal data. The CDA explored 130 articles published in the New York Times between 2000 and 2012. Findings reveal that the articles utilized four frames: confusion and lack of transparency, justification and private interests, law and self-regulation, and commodification of information. Articles used episodic framing often discussing specific instances of infringements rather than broader thematic accounts. Media coverage tended to frame personal information as a commodity that may be traded, rather than as a fundamental value.
Contextualizing the power of social media: Technology, communication and the Libya Crisis
Authors: Morris Laura
Published: December 2014

At the beginning of 2011, revolution across the MENA region threw into question the potential power of new media to bring about large-scale revolutionary pursuits. In Libya, the correlation between social media usage and social upheavals seemed, at most, tenuous in light of low levels of Internet penetration generally and in light of the state-sponsored Internet blackout following the nation-wide protests there. This qualitative research intends, through content analysis and semi-structured interviewing of key communicators, to decode the realities of how and why people were communicating through the crisis in Libya from its inception and to overcome misconceptions about social media as a stand alone or predominant factor in liberation across the region. What emerged from this case study was a confluence of actions and tools responsible for communication through the crisis, of which social media featured significantly. This paper will further discuss the significance of the convivial relationships of the Internet-based campaigners working towards a ‘democratic’ outcome in Libya and working beyond the limitations of national Internet connectedness. I conclude that there is a great potential for Internet-based networks to support widespread social upheaval within ripe socio-political settings.
Mediating the Black Pete discussion on Facebook: Slacktivism, flaming wars, and deliberation
Authors: Van Es Karin , Van Geenen Daniela , Boeschoten Thomas
Published: December 2014

In this paper we counter the idea that Facebook is a unified medium and stress the need to analyze the distinct qualities of its pages. We do so by exploring the Black Pete discussion on Facebook that ignited when United Nations investigator Verene Shepherd held a plea for the Dutch government to abolish the Saint Nicholas tradition, which features a black-face character, Black Pete. Both quantitative and qualitative methods are employed to interrogate how Facebook mediates this discussion in terms of divergent formatted spaces of participation. Reflecting on our findings against the notions of deliberation, slacktivism and flaming wars, we consider the particular features and potentials of different types of mediation.
COMPARATIVE ANALYSIS OF 14C AND TGA TECHNIQUES FOR THE QUANTIFICATION OF THE BIOMASS CONTENT OF END-OF-LIFE TIRES
Authors: Saiz-Rodríguez Leticia , Bermejo-Muñoz José María , Rodríguez-Díaz Andrés , Fernández-Torres Alberto , Rubinos-Pérez Antonio
Published: December 2014

Thermogravimetric analysis (TGA) and 14C techniques were compared for the determination of the biomass content of end-of-life tires (ELTs). Samples of different types (of ELTs) were prepared, and the biomass fraction of each sample was measured using the two methods (TGA and 14C). Six reference samples were also prepared with known quantities of natural rubber and stearic acid in order to establish the calibration curve necessary for the thermogravimetric analysis and to verify the accuracy of the results of the 14C analysis. The conclusions were that the 14C technique is the more valid, reliable, and precise method for determining the biomass content of end-of-life tires, since the results of the 14C tests of the reference samples coincided perfectly with the actual natural rubber and stearic acid content. On the other hand, the results of the thermogravimetric method differed considerably from the known natural rubber content of the reference samples as well as from the results of the 14C technique. This method is therefore not appropriate for use in determining the biomass content of end-of-life tires.
COMPARACIÓN DE CALIDAD EN LA PRODUCCIÓN DE CARBÓN VEGETAL EN LA FINCA EL PLANTEL, MASAYA
Authors: Reyes Flores Giovanni Francisco , Rodríguez Malespín Concepción Elí
Published: December 2014

La presente investigación tuvo como objetivo comparar la producción de calidad de carbón vegetal entre la fosa de tierra y el horno de ladrillo utilizando Eucalyptus camaldulensis, se seleccionaron árboles con diámetros entre 20-30 cm y mayores de 30 cm. Por cada categoría diamétrica se emplearon cinco árboles para un total de diez individuos, se tumbaron los árboles con la técnica de tala dirigida, con hacha a partir de 30 cm del suelo. Se procedió a medir la longitud de la troza en metros empleando una cinta métrica para la medición del diámetro medio. Se calculó el volumen del fuste limpio utilizando la fórmula de Smalian, posteriormente se trasladó trozas y ramas al sitio de carbonización, se depositaron por clase diamétrica donde se calculó el volumen empleando la fórmula de Huber, para la cubicación de las ramas se empleó el método de metro estéreo. Para la clase diamétrica de 20 a 30 cm se utilizó un volumen de 4.48 m3 y para mayor de 30 cm, 6.55 m3. Finalizado el proceso de carbonización se obtuvieron ocho sacos en la fosa de tierra, equivalente a 0.217 m3, en el horno de ladrillo se obtuvieron 18 sacos lo que representa 0.496 m3. Comparando los estándares de calidad de la FAO, con los obtenidos en este estudio, son aceptables, se concluye que el método de producción de horno de ladrillos usando arboles mayores de 30 cm es el mejor método para la producción de carbón vegetal. DOI: http://dx.doi.org/10.5377/calera.v13i21.1677