bluuebunny/crossref_metadata_2025 huggingface dataset:
No Relation between Therapeutic Response to Methylphenidate and its Cardiovascular Side Effects in Children with Attention-Deficit/Hyperactivity Disorder
Authors: Bhat Venkataramana , Grizenko Natalie , Sanche Steven , Joober Ridha
Published: September 2017

Objective

The aim of this study was to examine the relation between therapeutic response to methylphenidate (MPH) and its associated short term cardiovascular side effects (Systolic Blood Pressure-SBP, Diastolic Blood Pressure-DBP and Heart Rate-HR changes) in children with ADHD, based on the hypothesis that these parameters share common underlying mechanisms.

Method

A double-blind placebo-controlled crossover clinical trial of children 6 to 12 years old diagnosed with ADHD was done. The children were given one week of 0.5 mg/kg MPH and one week of placebo (divided into two equal doses, given twice every day). On the morning of the third day of each week, Blood Pressure (BP) and HR were recorded immediately before (at time 0) and after (at time 10 and 45 minutes) administration of MPH. Children were grouped into 4 categories according to their therapeutic response (large, moderate, mild or no response) to MPH. A mixed model analysis of variance was performed to determine whether response groups were different with regard to cardiovascular side effects.

Results

All variables were comparable among the four groups 10 min after treatment with MPH and with placebo. Small but significant (p < 0.001) increases were seen in SBP (3.65 mm of Hg) and DBP (3.99 mm of Hg) 45 minutes after administration of MPH. A small but significant decrease in HR (3.3 beats per minute) was observed 45 min after administration of placebo. No significant differences in SBP, DBP and HR were found between response groups.

Conclusions

MPH causes a small but significant change in BP at 45 minutes after administration. No changes in HR were observed with MPH at 45 minutes. Responders to MPH treatment do not differ from non-responders in occurrence of BP and HR changes, at least within 45 minutes after administration and with the MPH dosage used in the study.
Article Commentary: Improvements in the Measurement of Physical Activity in Childhood Obesity Research; Lessons from Large Studies of Accelerometers
Authors: Mattocks Calum , Tilling Kate , Ness Andy , Riddoch Chris
Published: September 2017

Advances in technology have improved our ability to measure physical activity in free-living humans. In the last few years, several large epidemiological studies in Europe and the United States have used accelerometers to assess physical activity in children and adolescents. The use of accelerometers to study physical activity has presented some challenges on how to summarise and interpret the data that they generate, however these studies are providing important information on the levels and patterns of physical activity among children and adolescents. Some studies have reported that few children and adolescents appear to meet the recommended minimum of 60 minutes of moderate to vigorous activity per day. Accelerometers have also allowed examination of the relationships between physical activity and health outcomes like obesity and other chronic disease risk factors such as insulin resistance, aerobic fitness, blood lipids and blood pressure. Use of accelerometers allows such relationships to be estimated with a precision that was previously impossible with self-report measures of physical activity. Such information is already advancing our understanding of the role that physical activity plays in preventing childhood obesity and cardiovascular disease risk.
Prevalence of Parasomnia in Autistic Children with Sleep Disorders
Authors: Ming Xue , Sun Ye-Ming , Nachajon Roberto V. , Brimacombe Michael , Walters Arthur S.
Published: September 2017

The prevalence of sleep related complaints is reported by questionnaire studies to be as high as 83.3% in children with autism spectrum disorders (ASD). Questionnaire studies report the presence of various parasomnia in ASD. However, no polysomnographic study reports non-REM parasomnias and only a single study reports REM related parasomnias in ASD. We investigated the prevalence and characteristics of sleep disorders by polysomnographic study and questionnaires in a cohort of 23 children with ASD and 23 age-matched children of a non-autistic comparison group. The results showed significantly more non-REM parasomnias in 14 children with ASD on polysomnograms (PSG) and 16 ASD children by questionnaire, a finding that was not associated with medication use, other comorbid medical or psychiatric disorders, or sleep disordered breathing. Of the 14 children with ASD who had PSG evidence of parasomnia, 11 of them had a history suggestive of parasomnia by questionnaire. There was a high sensitivity but a low specificity of parasomnia in ASD by questionnaire in predicting the presence of parasomnia in the PSG. Of the parasomnias recorded in the laboratory, 13 ASD children had Disorders of Partial Arousal, consistent with sleep terrors or confusional arousals. Furthermore, multiple episodes of partial arousal occurred in 11 of the 13 ASD children who had PSG evidence of Disorders of Partial Arousal. Of the 11 ASD children with multiple episodes of partial arousal, 6 ASD children had multiple partial arousals during both nights’ PSG study. Sleep architecture was abnormal in children with ASD, characterized by increased spontaneous arousals, prolonged REM latency and reduced REM percentage. These results suggest a high prevalence of parasomnia in this cohort of children with ASD and a careful history intake of symptoms compatible with parasomnia could be prudent to diagnose parasomnia in ASD children when performing a PSG is not possible.
IgA Nephropathy: A Twenty Year Retrospective Single Center Experience
Authors: Rube Jacob , Peyser Alexandra , Tarapore Freya , Scheckner Bari , Frank Rachel , Vento Suzanne , Hoffman Cathy , Charney Douglas , Valderamma Elsa , Goilav Beatrice , Trachtman Howard
Published: September 2017

IgA nephropathy (IgAN) is a common glomerular disease whose etiology is unknown. Previous studies have described the clinical and laboratory features but none have specifically compared patients during different time periods. This 20 year retrospective study was performed to assess trends in the severity of IgAN from 1989–2008. We reviewed 57 patient charts that contained a confirmed biopsy diagnosis of IgAN and recorded data at the time of diagnosis and the final follow-up appointment. Clinical data included physical examination, urine, and blood tests. Patients were separated into two cohorts, Cohort 1 1989–1998 and Cohort 2 1999–2008. An increase in severity was noted in Cohort 2 based on a significantly higher Up/c and lower serum albumin level. Other prognostic indicators including GFRe, hematocrit, and glomerular injury score also demonstrated a trend towards more severe disease over the past 20 years. The patients in both Cohorts received similar treatments and had comparable renal function at the last follow-up visit. Based on our findings, we suggest that although a kidney biopsy is required to diagnose IgAN, the procedure may not be necessary in patients clinically suspected of having the disease but who have normal kidney function and minimal urine abnormalities.
Hydronephrosis in Infants and Children: Natural History and Risk Factors for Persistence in Children Followed by a Medical Service
Authors: Van Dervoort Kristy , Lasky Stephanie , Sethna Christine , Frank Rachel , Vento Suzanne , Choi-Rosen Jeanne , Goilav Beatrice , Trachtman Howard
Published: September 2017

Background

Infants with neonatal hydronephrosis and a normal voiding cystourethrogram (VCUG) are presumed to have ureteropelvic junction obstruction (UPJO). There is little current information about the natural history of children with hydronephrosis or clinical factors that predict resolution of the radiological abnormality.

Objective

To determine the time course until spontaneous resolution of neonatal hydronephrosis and define risk factors for persistence of the abnormality.

Methods

This retrospective single center review examined infants and children <5 years of age with hydronephrosis who were followed for at least 12 months.

Results

136 children were identified (96 male:40 female). The mean age at diagnosis of hydronephrosis was 3.3 ± 9.7 months and 76% of the patients were diagnosed at birth. The hydronephrosis was unilateral in 98 (72%) of cases, and hydronephrosis was at least moderate in severity in 22% of affected kidneys. At last follow-up at 30 ± 10 months, the abnormality had resolved in 77 out of 115 (67%) available patients, 30 (26%) had been referred to urology, and 12 (10%) had persistent hydronephrosis. Severity of hydronephrosis was the only clinical feature that predicted persistence of the abnormality (P < 0.001). There was an association between detection at birth and lack of resolution of hydronephrosis.

Conclusions

Children with hydronephrosis and presumed UPJO and normal kidney parenchyma can be followed for at least 2 years to allow for spontaneous resolution before referral to urology. Serial sonography can be performed at 6 month intervals in uncomplicated cases. More severe hydronephrosis and presence of the lesion at birth may predict infants and children requiring closer observation and referral for possible surgical correction of the hydronephrosis.
A Novel Homozygous Frameshift Mutation in Exon 2 of LEP Gene Associated with Severe Obesity: A Case Report
Authors: Altawil Ashwaq Shukri , Mawlawi Horia Ahmad , Alghamdi Khalid Ateeq , Almijmaj Faten Fohaid
Published: September 2017

Background

Monogenic obesity is a rare type of obesity caused by a mutation in a single gene. Patients with monogenic obesity may develop early onset of obesity and severe metabolic abnormalities.

Case Presentation

A two-and-half-year-old girl was presented to our clinic because of excessive weight gain and hyperphagia. She was born at full term, by normal vaginal delivery with birth weight of 2.82 kg and no complications during pregnancy. The patient was the second child of two healthy, non-obese Saudis with known consanguinity. She gained weight rapidly leading to obesity at the age of three months.

Methods

The demographic data and clinical features were recorded. Blood samples were collected and tested for endocrine and metabolic characteristics and genetic studies. Mutations of the LEP gene were screened. The coding exons 2 and 3 and the corresponding exon–intron boundaries were amplified by polymerase chain reaction using specific primers, analyzed by direct sequencing using an ABI sequencer 3500 xL GA (Applied Biosystems), and evaluated using the JSI SeqPilot software. The resulting sequence data were compared with the reference MM_0002302.

Conclusion

We report a novel homozygous frameshift mutation c.144delin TAC (G1n49Thrfs*23) in exon 2 of the LEP gene associated with extreme obesity.
Validity of Some Anthropometric Indicators in the Prediction of High Systolic Blood Pressure among Indian Adolescents
Authors: Rao Shobha , Kanade Asawari N. , Apte Priti P.
Published: September 2017

Background

In view of the increasing prevalence of obesity in children, it is necessary to investigate the relative performance of different indicators used for its assessment and health consequences.

Objectives

To examine concordance between various indicators used for assessing obesity among adolescents and to examine their ability to predict risk of high systolic blood pressure.

Design

Cross-sectional study, from two schools catering to affluent class.

Subjects

Children in age 9–16 yr (n = 1146 boys and 1036 girls).

Measurements

Body weight, height, skinfold thickness at triceps (TSFT) and body fat percent by trained investigators and blood pressure measurement by a pediatrician using sphygmomanometer.

Results

Prevalence of overweight was lowest with criterion of TSFT (11.7% in boys; 7.6% in girls) and was highest using criterion of body fat percent (53.7% in boys and 28.4% in girls). Body mass index (BMI) had high significant correlation with each of the indicator and with systolic blood pressure (SBP) as well, in both sexes. All the indicators with conventional cut offs showed poor sensitivity for predicting high SBP. However, receiver operating characteristics (ROC) cut-offs improved sensitivity considerably, but the values were much lower compared to conventional cut-offs.

Conclusions

There is considerable disparity in the estimates of overweight children obtained by different indicators. Lower values of ROC cut-offs highlights the need for population specific customized classification systems for assessing obesity in view of the probable population differences in relative risks of non-communicable adult diseases.
Beyond Television: Children's Engagement with Online Food and Beverage Marketing
Authors: Brady Jennifer , Farrell Amber , Wong Sharon , Mendelson Rena
Published: September 2017

Background

Food and beverage marketing has been implicated in the childhood obesity “pandemic.” Prior studies have established the negative impact of television advertising on children's dietary intake, yet few have considered the role of online food and beverage marketing, particularly within the Canadian context.

Objective

This study explores children's engagement in online marketing and investigates the potential impact on their dietary intake.

Methods

Participants were recruited from the Ryerson University Summer Day Camp to participate in a single one-on-one semi-structured interview.

Results

A total of 83 children (age 7 to 13 years; mean 9.99 years; 56.3% boys, 43.8% girls) participated in the study. Fewer children thought that there is food, drink, or candy advertising on the internet (67.7%) than on television (98.8%) (p > 0.001). Awareness of online marketing increased with age: 7 to 8 year olds (23.67%; 4), 9 to 10 years (63.89%; 23), 11 to 12 years (86.96%; 20); 13 years (100%; 9). Over one-third of children had visited a website after seeing the address advertised on television (n = 32; 38.55%) or on product package (n = 29; 34.94%).

Conclusions

Branded internet sites, commonly featured on television and product packaging, offer new opportunities for marketers to reach children with messages promoting commercial food and beverage items. These websites are subsequently spread via word-of-mouth through children's peer networks. The independent impact of web-based food, drink and candy marketing, as well as the synergistic effect of multi-channel product promotion, on children's dietary intake merits further investigation.
Immunolocalization of Dynamin I Protein in Projection Neurons of the Visual System of the Adult Cat
Authors: Cnops Lieselotte , Cuyvers Annemie , Hu Tjing-Tjing , Arckens Lutgarde
Published: September 2017

We here report on the immunolocalization of Dynamin I (Dyn I) in neurons of the visual system of the cat. The lateral geniculate nucleus (LGN) complex displayed abundant Dyn I immunoreactivity in typical relay cells of the X-, Y- and W-pathway. The superficial and deep layers of the superior colliculus were also populated by Dyn I-immunoreactive projection neurons of the W- and Y-cell system. In primary visual areas 17 and 18, many densely packed layer VI neurons were intensely stained. A clear Dyn I signal was also demonstrated in pyramidal neurons of supragranular layers II and III, while layer IV displayed low Dyn I immunoreactivity. Additionally, area 18 displayed larger border pyramidal neurons in layer III compared to area 17. Generally, Dyn I was localized to the cell body and dendrites of neurons, to the neuropil and sometimes also to axon bundles. Typically, the Dyn I signal was not always uniformly distributed within the somatodendritic compartment. Based on its widespread distribution mainly in projection neurons Dyn I may play a fundamental role in mature neurons of different cortical and subcortical structures of the adult mammalian brain.
The effects of Fetal Surgery on Retinopathy of Prematurity Development
Authors: Nallasamy Sudha , Davidson Stefanie L. , Howell Lori J. , Hedrick Holly , Flake Alan W. , Crombleholme Timothy M. , Adzick N. Scott , Young Terri L.
Published: September 2017

Background

Fetal surgery is selectively offered for severe or life-threatening fetal malformations. These infants are often born prematurely and are thus at risk for retinopathy of prematurity (ROP). It is not known whether fetal surgery confers an increased risk of developing severe ROP relative to published rates in standard premature populations ≤37 weeks of age grouped by birth weight (<1500 grams or ≥1500 grams).

Design

This is a retrospective chart review.

Methods

We reviewed the charts of 137 patients who underwent open fetal/fetoscopic surgery from 1996–2004. Surgical indications included twin-twin transfusion syndrome (TTTS), myelomeningocele (MMC), congenital diaphragmatic hernia (CDH), sacrococcygeal teratoma (SCT), cystic adenomatoid malformation of the lung (CCAM), and twin reversed arterial perfusion sequence (TRAP). Of these, 17 patients had local ROP examination data. Binomial tests were performed to assess whether rates of ROP in our fetal/fetoscopic surgery cohort were significantly different from published rates.

Results

There were 5 patients each with an underlying diagnosis of TTTS and MMC, 2 patients each with CDH and TRAP, and 1 patient each with SCT, CCAM, and mediastinal teratoma. The mean gestational age at surgery was 23 4 /7 ± 2 3 /7 weeks, mean gestational age at birth was 30 ± 2 5 /7 weeks, and mean birth weight was 1449 ± 510 grams (610–2485). Compared to published rates of ROP and threshold ROP, our fetal surgery patients had significantly higher rates of ROP and threshold ROP in both the <1500 grams and the ≥1500 grams group (all p-values <0.05).

Conclusions

Fetal/fetoscopic surgery appears to significantly increase the rate of ROP and threshold ROP development. Greater numbers are needed to confirm these observations.
Pharmacokinetics of Stereoisomeric Dipeptide Prodrugs of Acyclovir following Intravenous and Oral Administrations in Rats: A study Involving in vivo corneal Uptake of Acyclovir following Oral Dosing
Authors: Talluri Ravi S. , Gaudana Ripal , Hariharan Sudharshan , Mitra Ashim K.
Published: September 2017

Objective

To delineate the plasma pharmacokinetics and determine the corneal uptake of valine based stereoisomeric dipeptide prodrugs of acyclovir (ACV) in rats.

Methods

Male Sprague-Dawley rats were used for the study. Pharmacokinetics of ACV, L-valine-acyclovir (LACV), L-valine-D-valine-acyclovir (LDACV) and D-valine-L-valine acyclovir (DLACV) prodrugs were delineated. These compounds were administered intravenously as a bolus via jugular vein cannula and orally by gavage. Samples were purified by protein precipitation method and analyzed by LC-MS/MS. Pertinent pharmacokinetic parameters were obtained by using WinNonlin. Corneal uptake studies of LDACV and LACV were studied following oral administration.

Results

Following i.v. administration, the area under the curve (AUC) in μM*min of generated ACV was in the order of LACV > LDACV > DLACV indicating their rate of metabolism. The AUC values of total drug obtained in the systemic circulation after oral administration LACV and LDACV were 1077.93 ± 236.09 and 1141.76 ± 73.67 μM*min, respectively. DLACV exhibited poor oral absorption. Cmax (μM) and AUC of the intact prodrug obtained in the systemic circulation following oral administration of LDACV were almost 4–5 times higher than LACV. Moreover, concentrations achieved in the cornea after oral administration of LDACV were almost two times of LACV.

Conclusions

LDACV increased both the oral bioavailability and subsequent in vivo corneal uptake of ACV Hence, LDACV can be considered as the most promising drug candidate for delivery of ACV, in treatment of both genital herpes and ocular herpes keratitis after oral administration.
Spatial distribution and occurrence probability of regional new
particle formation events in eastern China
Authors: Shen Xiaojing , Sun Junying , Kivekäs Niku , Kristensson Adam , Zhang Xiaoye , Zhang Yangmei , Zhang Lu , Fan Ruxia , Qi Xuefei , Ma Qianli , Zhou Huaigang
Published: September 2017

Abstract. In this work, the spatial extent of new particle formation (NPF) events and the relative probability of observing particles originating from different spatial origins around three rural sites in eastern China were investigated with the NanoMap method, using particle number size distribution (PNSD) data and air mass back trajectories. The length of the datasets used were 7-year, 1.5-year and 3-year at rural sites Shangdianzi (SDZ) in North China Plain (NCP), Mt. Tai (TS) in central eastern China, and Lin'an (LAN) in Yangtze River Delta region in eastern China, respectively. Regional NPF events were observed to occur with the horizontal extent larger than 500 km at SDZ and TS, favored by the fast transport of northwesterly air masses. At LAN, however, the spatial footprint of NPF events was mostly observed around the site within 100–200 km. Difference in the horizontal spatial distribution of new particle source areas at different sites was connected to typical meteorological conditions at the sites. Consecutive large-scale regional NPF events were observed at SDZ and TS simultaneously and were associated with a high surface pressure system dominating over this area. Simultaneous NPF events at SDZ and LAN were seldom observed. At SDZ the polluted air masses arriving over NCP were associated with higher particle growth rates (GR) and new particle formation rates (J) than air masses from Inner Mongolia (IM). At TS the same phenomenon was observed for J, but GR was somewhat lower in air masses arriving over NCP compared to those arriving from IM. The capability of NanoMap to capture the NPF occurrence probability depends on the length of the dataset of PNSD measurement, but also on topography around the measurement site and typical air mass advection speed during NPF events. Thus the long-term measurements of PNSD in planetary boundary layer are necessary in the further study on spatial extent and probability of NPF events. The spatial extent, relative probability of occurrence and typical evolution of PNSD during NPF event presented in this study provide valuable information to further understand the climate and air quality effect of new particle formation.
Groundwater data improve modelling of headwater stream CO2 outgassing with a stable DIC isotope approach
Authors: Marx Anne , Conrad Marcus , Aizinger Vadym , Prechtel Alexander , van Geldern Robert , Barth Johannes A. C.
Published: September 2017

Abstract. A large portion of terrestrially-derived carbon outgasses as carbon dioxide (CO2) from streams and rivers to the atmosphere. Particularly, the amount of CO2 outgassing from small headwater streams was indicated as highly uncertain. Conservative estimates suggest that they contribute 36 % (i.e., 0.93 petagrams C yr−1) of total CO2 outgassing from all rivers and streams worldwide. In this study, stream pCO2, dissolved inorganic carbon (DIC) and δ13CDIC data were used to determine CO2 outgassing from an acidic headwater stream in the Uhlirska catchment (Czech Republic). This stream drains a catchment with silicate bedrock. The applied stable isotope model is based on the principle, that the 13C / 12C ratio of its sources and the intensity of CO2 outgassing control the isotope ratio of DIC in stream water. It avoids the use of the gas transfer velocity parameter (k) that is highly variable and mostly difficult to constrain. Model results indicate that CO2 outgassing contributed 80 % to the annual stream inorganic carbon loss in the Uhlirska catchment. This translated to a CO2 outgassing rate from the stream of 5.2 t C yr−1 and to 2.9 g C m−2 yr−1, when normalised to the catchment area. Large temporal variations with maximum values during spring snowmelt and summer emphasise the need for investigations at higher temporal resolution. We improved the model uncertainty by incorporating groundwater data to better constrain the isotope compositions of initial DIC. Due to the large global abundance of acidic, humic-rich headwaters, we underline the importance of this integral approach for global applications.
Technical note: Cascade of submerged reservoirs as a rainfall–runoff model
Authors: Kurnatowski Jacek
Published: September 2017

Abstract. The rainfall–runoff conceptual model as a cascade of submerged linear reservoirs with particular outflows depending on storages of adjoining reservoirs is developed. The model output contains different exponential functions with roots of Chebyshev polynomials of the first kind as exponents. The model is applied to instantaneous unit hydrograph (IUH) and recession curve problems and compared with the analogous results of the Nash cascade. A case study is performed on a basis of 46 recession periods. Obtained results show the usefulness of the model as an alternative concept to the Nash cascade.
Towards improved parameterization of a macroscale hydrologic model in a discontinuous permafrost boreal forest ecosystem
Authors: Endalamaw Abraham , Bolton W. Robert , Young-Robertson Jessica M. , Morton Don , Hinzman Larry , Nijssen Bart
Published: September 2017

Abstract. Modeling hydrological processes in the Alaskan sub-arctic is challenging because of the extreme spatial heterogeneity in soil properties and vegetation communities. Nevertheless, modeling and predicting hydrological processes is critical in this region due to its vulnerability to the effects of climate change. Coarse-spatial-resolution datasets used in land surface modeling pose a new challenge in simulating the spatially distributed and basin-integrated processes since these datasets do not adequately represent the small-scale hydrological, thermal, and ecological heterogeneity. The goal of this study is to improve the prediction capacity of mesoscale to large-scale hydrological models by introducing a small-scale parameterization scheme, which better represents the spatial heterogeneity of soil properties and vegetation cover in the Alaskan sub-arctic. The small-scale parameterization schemes are derived from observations and a sub-grid parameterization method in the two contrasting sub-basins of the Caribou Poker Creek Research Watershed (CPCRW) in Interior Alaska: one nearly permafrost-free (LowP) sub-basin and one permafrost-dominated (HighP) sub-basin. The sub-grid parameterization method used in the small-scale parameterization scheme is derived from the watershed topography. We found that observed soil thermal and hydraulic properties – including the distribution of permafrost and vegetation cover heterogeneity – are better represented in the sub-grid parameterization method than the coarse-resolution datasets. Parameters derived from the coarse-resolution datasets and from the sub-grid parameterization method are implemented into the variable infiltration capacity (VIC) mesoscale hydrological model to simulate runoff, evapotranspiration (ET), and soil moisture in the two sub-basins of the CPCRW. Simulated hydrographs based on the small-scale parameterization capture most of the peak and low flows, with similar accuracy in both sub-basins, compared to simulated hydrographs based on the coarse-resolution datasets. On average, the small-scale parameterization scheme improves the total runoff simulation by up to 50 % in the LowP sub-basin and by up to 10 % in the HighP sub-basin from the large-scale parameterization. This study shows that the proposed sub-grid parameterization method can be used to improve the performance of mesoscale hydrological models in the Alaskan sub-arctic watersheds.
CHANGE ANALYSIS OF LASER SCANS OF LABORATORY ROCK SLOPES SUBJECT TO WAVE ATTACK TESTING
Authors: Shen Y. , Lindenbergh R. , Hofland B. , Kramer R.
Published: September 2017

Abstract. For better understanding how coastal structures with gentle slopes behave during high energy events, a wave attack experiment representing a storm of 3000 waves was performed in a flume facility. Two setups with different steepness of slope were compared under the same conditions. In order to quantify changes in the rock slopes after the wave attack, a terrestrial laser scanner was used to obtain 3D coordinates of the rock surface before and after each experiment. Next, through a series of processing steps, the point clouds were converted to a suitable 2D raster for change analysis. This allowed to estimate detailed and quantitative change information. The results indicate that the area around the artificial coast line, defined as the intersection between sloped surface and wave surface, is most strongly affected by wave attacks. As the distances from the sloped surface to the waves are shorter, changes for the mildly sloped surface, slope 1 (1 : 10), are distributed over a larger area compared to the changes for the more steeply sloped surface, slope 2 (1 : 5). The results of this experiment show that terrestrial laser scanning is an effective and feasible method for change analysis of rock slopes in a laboratory setting. Most striking results from a process point of view is that the transport direction of the rocks change between the two different slopes: from seaward transport for the steeper slope to landward transport for the milder slope.
SURFACE FITTING FILTERING OF LIDAR POINT CLOUD WITH WAVEFORM INFORMATION
Authors: Xing S. , Li P. , Xu Q. , Wang D. , Li P.
Published: September 2017

Abstract. Full-waveform LiDAR is an active technology of photogrammetry and remote sensing. It provides more detailed information about objects along the path of a laser pulse than discrete-return topographic LiDAR. The point cloud and waveform information with high quality can be obtained by waveform decomposition, which could make contributions to accurate filtering. The surface fitting filtering method with waveform information is proposed to present such advantage. Firstly, discrete point cloud and waveform parameters are resolved by global convergent Levenberg Marquardt decomposition. Secondly, the ground seed points are selected, of which the abnormal ones are detected by waveform parameters and robust estimation. Thirdly, the terrain surface is fitted and the height difference threshold is determined in consideration of window size and mean square error. Finally, the points are classified gradually with the rising of window size. The filtering process is finished until window size is larger than threshold. The waveform data in urban, farmland and mountain areas from “WATER (Watershed Allied Telemetry Experimental Research)” are selected for experiments. Results prove that compared with traditional method, the accuracy of point cloud filtering is further improved and the proposed method has highly practical value.
IMPROVED CONJUGATE GRADIENT BUNDLE ADJUSTMENT OF DUNHUANG WALL PAINTING IMAGES
Authors: Hu K. , Huang X. , You H.
Published: September 2017

Abstract. Bundle adjustment with additional parameters is identified as a critical step for precise orthoimage generation and 3D reconstruction of Dunhuang wall paintings. Due to the introduction of self-calibration parameters and quasi-planar constraints, the structure of coefficient matrix of the reduced normal equation is banded-bordered, making the solving process of bundle adjustment complex. In this paper, Conjugate Gradient Bundle Adjustment (CGBA) method is deduced by calculus of variations. A preconditioning method based on improved incomplete Cholesky factorization is adopt to reduce the condition number of coefficient matrix, as well as to accelerate the iteration rate of CGBA. Both theoretical analysis and experimental results comparison with conventional method indicate that, the proposed method can effectively conquer the ill-conditioned problem of normal equation and improve the calculation efficiency of bundle adjustment with additional parameters considerably, while maintaining the actual accuracy.
A GROUND-BASED LIDAR AND IMAGING SPECTROMETER SYNCHRONOUS EXPERIMENT ON VEGETATION
Authors: Hong T. , Luo X. , Chen H. , Hui J.
Published: September 2017

Abstract. Extraction of vegetation canopy structure parameters is of great significance for researching global ecosystem and environment. Focused on the effective synergy between active and passive sensors, we carried out some ground-based observations about different vegetation on different terrains. In different experimental sites, a light detection and ranging (LiDAR) data and an imaging spectrum data of typical vegetation were collected from different directions and angles. Meanwhile, a variety of canopy structure parameters, including plant height, crown breadth, leaf area index, etc, were measured. The whole observed results form a comprehensive ground synchronous data set corresponding to flight data and provide data support for development and validation of synergic retrieval methods of vegetation canopy structure parameters. Our specific experimental objectives and design are introduced, including the selection of sampling plots, arrangement of observation stations, acquisition of active and passive data, and measurement of auxiliary data. The processing and practical applications of those obtained synchronous data are also discussed. Finally, our experimental experience is summarized and it is a valuable reference for remote sensing researchers.
GLOBAL PATCH MATCHING
Authors: Huang X. , Hu K. , Ling X. , Zhang Y. , Lu Z. , Zhou G.
Published: September 2017

Abstract. This paper introduces a novel global patch matching method that focuses on how to remove fronto-parallel bias and obtain continuous smooth surfaces with assuming that the scenes covered by stereos are piecewise continuous. Firstly, simple linear iterative cluster method (SLIC) is used to segment the base image into a series of patches. Then, a global energy function, which consists of a data term and a smoothness term, is built on the patches. The data term is the second-order Taylor expansion of correlation coefficients, and the smoothness term is built by combing connectivity constraints and the coplanarity constraints are combined to construct the smoothness term. Finally, the global energy function can be built by combining the data term and the smoothness term. We rewrite the global energy function in a quadratic matrix function, and use least square methods to obtain the optimal solution. Experiments on Adirondack stereo and Motorcycle stereo of Middlebury benchmark show that the proposed method can remove fronto-parallel bias effectively, and produce continuous smooth surfaces.
APPLICATION AND PERFORMANCE ANALYSIS OF A NEW BUNDLE ADJUSTMENT MODEL
Authors: Sun Y. , Liu X. , Chen R. , Wan J. , Wang Q. , Wang H. , Li Y. , Yan L.
Published: September 2017

Abstract. As the basis for photogrammetry, Bundle Adjustment (BA) can restore the pose of cameras accurately, reconstruct the 3D models of environment, and serve as the criterion of digital production. For the classical nonlinear optimization of BA model based on the Euclidean coordinate, it suffers the problem of being seriously dependent on the initial values, making it unable to converge fast or converge to a global minimum. This paper first introduces a new BA model based on parallax angle feature parametrization, and then analyses the applications and performance of the model used in photogrammetry field. To discuss the impact and the performance of the model (especially in aerial photogrammetry), experiments using two aerial datasets under different initial values were conducted. The experiment results are better than some well-known software packages of BA, and the simulation results illustrate the stability of the new model than the normal BA under the Euclidean coordinate. In all, the new BA model shows promising applications in faster and more efficient aerial photogrammetry with good convergence and fast convergence speed.
A PRELIMINARY WORK ON LAYOUT SLAM FOR RECONSTRUCTION OF INDOOR CORRIDOR ENVIRONMENTS
Authors: Baligh Jahromi A. , Sohn G. , Shahbazi M. , Kang J.
Published: September 2017

Abstract. We propose a real time indoor corridor layout estimation method based on visual Simultaneous Localization and Mapping (SLAM). The proposed method adopts the Manhattan World Assumption at indoor spaces and uses the detected single image straight line segments and their corresponding orthogonal vanishing points to improve the feature matching scheme in the adopted visual SLAM system. Using the proposed real time indoor corridor layout estimation method, the system is able to build an online sparse map of structural corner point features. The challenges presented by abrupt camera rotation in the 3D space are successfully handled through matching vanishing directions of consecutive video frames on the Gaussian sphere. Using the single image based indoor layout features for initializing the system, permitted the proposed method to perform real time layout estimation and camera localization in indoor corridor areas. For layout structural corner points matching, we adopted features which are invariant under scale, translation, and rotation. We proposed a new feature matching cost function which considers both local and global context information. The cost function consists of a unary term, which measures pixel to pixel orientation differences of the matched corners, and a binary term, which measures the amount of angle differences between directly connected layout corner features. We have performed the experiments on real scenes at York University campus buildings and the available RAWSEEDS dataset. The incoming results depict that the proposed method robustly performs along with producing very limited position and orientation errors.
INDOOR SMARTPHONE NAVIGATION USING A COMBINATION OF WI-FI AND INERTIAL NAVIGATION WITH INTELLIGENT CHECKPOINTS
Authors: Hofer H. , Retscher G.
Published: September 2017

Abstract. For Wi-Fi positioning location fingerprinting is one of the most commonly employed localization technique. To achieve an acceptable level of positioning accuracy on the few meter level, i.e., to provide at least room resolution in buildings, such an approach is very labour consuming as it requires a high density of reference points. Thus, the novel approach developed aims at a significant reduction of workload for the training phase. The basic idea is to intelligently choose waypoints along possible users’ trajectories in the indoor environment. These waypoints are termed intelligent checkpoints (iCPs) and serve as reference points for the fingerprinting localization approach. They are selected along the trajectories in such a way that they define a logical sequence with their ascending order. Thereby, the iCPs are located, for instance, at doors at entrances to buildings, rooms, along corridors, etc., or in low density along the trajectory to provide a suitable absolute user localization. Continuous positioning between these iCPs is obtained with the help of the smartphones’ inertial sensors. While walking along a selected trajectory to the destination a dynamic recognition of the iCPs is performed and the drift of the inertial sensors is reduced as the iCP recognition serves as absolute position update. Conducted experiments in a multi-storey office building have shown that positioning accuracy of around 2.0 m are achievable which goes along with a reduction of workload by three quarter using this novel approach. The iCP concept and performance are presented and demonstrated in this paper.
INTEGRATED SHORELINE EXTRACTION APPROACH WITH USE OF RASAT MS AND SENTINEL-1A SAR IMAGES
Authors: Demir N. , Oy S. , Erdem F. , Şeker D. Z. , Bayram B.
Published: September 2017

Abstract. Shorelines are complex ecosystems and highly important socio-economic environments. They may change rapidly due to both natural and human-induced effects. Determination of movements along the shoreline and monitoring of the changes are essential for coastline management, modeling of sediment transportation and decision support systems. Remote sensing provides an opportunity to obtain rapid, up-to-date and reliable information for monitoring of shoreline. In this study, approximately 120 km of Antalya-Kemer shoreline which is under the threat of erosion, deposition, increasing of inhabitants and urbanization and touristic hotels, has been selected as the study area. In the study, RASAT pansharpened and SENTINEL-1A SAR images have been used to implement proposed shoreline extraction methods. The main motivation of this study is to combine the land/water body segmentation results of both RASAT MS and SENTINEL-1A SAR images to improve the quality of the results. The initial land/water body segmentation has been obtained using RASAT image by means of Random Forest classification method. This result has been used as training data set to define fuzzy parameters for shoreline extraction from SENTINEL-1A SAR image. Obtained results have been compared with the manually digitized shoreline. The accuracy assessment has been performed by calculating perpendicular distances between reference data and extracted shoreline by proposed method. As a result, the mean difference has been calculated around 1 pixel.
MONITORING AND EVALUATION OF A LONG-SPAN RAIWAY BRIDGE USING SENTINEL-1 DATA
Authors: Huang Q. , Crosetto M. , Monserrat O. , Crippa B.
Published: September 2017

Abstract. This paper is focused on displacement monitoring of a bridge, which is one of the key aspects of its structural health monitoring. A simplified Persistent Scatterer Interferometry (PSI) approach is used to monitor the displacements of the Nanjing Dashengguan Yangtze River High-speed Railway Bridge (China). This bridge is 1272 m long and hosts a total of 6 railway lines. The analysis was based on a set of twenty-nine Sentinel-1A images, acquired from April 2015 to August 2016. A dense set of measurement points were selected on the bridge. The PSI results show a maximum longitudinal displacement of 150 mm, on each side of the bridge. The displacements are strongly correlated with the temperature, showing that they are due to thermal expansion. Using the PSI results, the Coefficient of Thermal Expansion (CTE) of the whole bridge was estimated. The result agrees well with the CTE of the bridge materials. Using a regression model, the PSI-measured displacements were compared with in-situ measurements. The paper proposes a procedure to assess the performance of the movable bearings of the bridge, which is based on the PSI measurements.
ESTIMATION OF PHASE DELAY DUE TO PRECIPITABLE WATER FOR DINSARBASED
LAND DEFORMATION MONITORING
Authors: Susaki J. , Maeda N. , Akatsuka S.
Published: September 2017

Abstract. In this paper, we present a method for using the estimated precipitable water (PW) to mitigate atmospheric phase delay in order to improve the accuracy of land-deformation assessment with differential interferometric synthetic aperture radar (DInSAR). The phase difference obtained from multi-temporal synthetic aperture radar images contains errors of several types, and the atmospheric phase delay can be an obstacle to estimating surface subsidence. In this study, we calculate PW from external meteorological data. Firstly, we interpolate the data with regard to their spatial and temporal resolutions. Then, assuming a range direction between a target pixel and the sensor, we derive the cumulative amount of differential PW at the height of the slant range vector at pixels along that direction. The atmospheric phase delay of each interferogram is acquired by taking a residual after a preliminary determination of the linear deformation velocity and digital elevation model (DEM) error, and by applying high-pass temporal and low-pass spatial filters. Next, we estimate a regression model that connects the cumulative amount of PW and the atmospheric phase delay. Finally, we subtract the contribution of the atmospheric phase delay from the phase difference of the interferogram, and determine the linear deformation velocity and DEM error. The experimental results show a consistent relationship between the cumulative amount of differential PW and the atmospheric phase delay. An improvement in land-deformation accuracy is observed at a point at which the deformation is relatively large. Although further investigation is necessary, we conclude at this stage that the proposed approach has the potential to improve the accuracy of the DInSAR technique.
POINT-CLOUD COMPRESSION FOR VEHICLE-BASED MOBILE MAPPING SYSTEMS USING PORTABLE NETWORK GRAPHICS
Authors: Kohira K. , Masuda H.
Published: September 2017

Abstract. A mobile mapping system is effective for capturing dense point-clouds of roads and roadside objects．Point-clouds of urban areas, residential areas, and arterial roads are useful for maintenance of infrastructure, map creation, and automatic driving. However, the data size of point-clouds measured in large areas is enormously large. A large storage capacity is required to store such point-clouds, and heavy loads will be taken on network if point-clouds are transferred through the network. Therefore, it is desirable to reduce data sizes of point-clouds without deterioration of quality. In this research, we propose a novel point-cloud compression method for vehicle-based mobile mapping systems. In our compression method, point-clouds are mapped onto 2D pixels using GPS time and the parameters of the laser scanner. Then, the images are encoded in the Portable Networking Graphics (PNG) format and compressed using the PNG algorithm. In our experiments, our method could efficiently compress point-clouds without deteriorating the quality.
FAST AND ROBUST REGISTRATION OF MULTIMODAL REMOTE SENSING IMAGES VIA DENSE ORIENTATED GRADIENT FEATURE
Authors: Ye Y.
Published: September 2017

Abstract. This paper presents a fast and robust method for the registration of multimodal remote sensing data (e.g., optical, LiDAR, SAR and map). The proposed method is based on the hypothesis that structural similarity between images is preserved across different modalities. In the definition of the proposed method, we first develop a pixel-wise feature descriptor named Dense Orientated Gradient Histogram (DOGH), which can be computed effectively at every pixel and is robust to non-linear intensity differences between images. Then a fast similarity metric based on DOGH is built in frequency domain using the Fast Fourier Transform (FFT) technique. Finally, a template matching scheme is applied to detect tie points between images. Experimental results on different types of multimodal remote sensing images show that the proposed similarity metric has the superior matching performance and computational efficiency than the state-of-the-art methods. Moreover, based on the proposed similarity metric, we also design a fast and robust automatic registration system for multimodal images. This system has been evaluated using a pair of very large SAR and optical images (more than 20000 × 20000 pixels). Experimental results show that our system outperforms the two popular commercial software systems (i.e. ENVI and ERDAS) in both registration accuracy and computational efficiency.