bluuebunny/crossref_metadata_2025 huggingface dataset:
WHY THE HORIZON IS IMPORTANT FOR AIRBORNE SENSE AND AVOID APPLICATIONS
Authors: Minwalla C. , Ellis K.
Published: August 2015

Abstract. The utility of the horizon for airborne sense-and-avoid (ABSAA) applications is explored in this work. The horizon is a feature boundary across which an airborne scene can be separated into surface and sky and serves as a salient, heading-independent feature that may be mapped into an electro-optical sensor. The virtual horizon as established in this paper represents the horizon that would be seen assuming a featureless earth model and infinite visibility and is distinct from the apparent horizon in an imaging sensor or the pilot’s eye. For level flight, non-maneuvering collision course trajectories, it is expected that targets of interest will appear in close proximity to this virtual horizon. This paper presents a model for establishing the virtual horizon and its projection into a camera reference plane as part of the sensing element in an ABSAA system. Evaluation of the model was performed on a benchmark dataset of airborne collision geometries flown at the National Research Council (NRC) using the Cerberus camera array. The model was compared against ground truth flight test data collected using high accuracy inertial navigation systems aboard aircraft on several ’near-miss’ intercepts. The paper establishes the concept of ’virtual horizon proximity’ (VHP), the minimum distance from a detected target and the virtual horizon, and investigates the utility of using this metric as a means of rejecting false positive detections, and increasing range at first detection through the use of a region of interest (ROI) mask centred on the virtual horizon. The use of this horizon-centred ROI was shown to increase the range at first detection by an average factor of two, and was shown to reduce false positives for six popular feature detector algorithms applied across the suite of flight test imagery.
THE DIRECT GEOREFERENCING APPLICATION AND PERFORMANCE ANALYSIS OF UAV HELICOPTER IN GCP-FREE AREA
Authors: Lo C. F. , Tsai M. L. , Chiang K. W. , Chu C. H. , Tsai G. J. , Cheng C. K. , El-Sheimy N. , Ayman H.
Published: August 2015

Abstract. There are many disasters happened because the weather changes extremely in these years. To facilitate applications such as environment detection or monitoring becomes very important. Therefore, the development of rapid low cost systems for collecting near real-time spatial information is very critical. Rapid spatial information collection has become an emerging trend for remote sensing and mapping applications. This study develops a Direct Georeferencing (DG) based Unmanned Aerial Vehicle (UAV) helicopter photogrammetric platform where an Inertial Navigation System (INS)/Global Navigation Satellite System (GNSS) integrated Positioning and Orientation System (POS) system is implemented to provide the DG capability of the platform. The performance verification indicates that the proposed platform can capture aerial images successfully. A flight test is performed to verify the positioning accuracy in DG mode without using Ground Control Points (GCP). The preliminary results illustrate that horizontal DG positioning accuracies in the x and y axes are around 5 meter with 100 meter flight height. The positioning accuracy in the z axis is less than 10 meter. Such accuracy is good for near real-time disaster relief. The DG ready function of proposed platform guarantees mapping and positioning capability even in GCP free environments, which is very important for rapid urgent response for disaster relief. Generally speaking, the data processing time for the DG module, including POS solution generalization, interpolation, Exterior Orientation Parameters (EOP) generation, and feature point measurements, is less than 1 hour.
LOCAL ALGORITHM FOR MONITORING TOTAL SUSPENDED SEDIMENTS IN MICRO-WATERSHEDS USIN DRONES AND REMOTE SENSING APPLICATIONS. CASE STUDY: TEUSACÁ RIVER, LA CALERA, COLOMBIA
Authors: Sáenz N. A. , Paez D. E. , Arango C.
Published: August 2015

Abstract. An empirical relationship of Total Suspended Sediments (TSS) concentrations and reflectance values obtained with Drones’ aerial photos and processed using remote sensing tools was set up as the main objective of this research. A local mathematic algorithm for the micro-watershed of the Teusacá River at La Calera, Colombia, was developed based on the computing of four component of bands from consumed-grade cameras obtaining from each their corresponding reflectance values from procedures for correcting digital camera imagery and using statistical analysis for study the fit and RMSE of 25 regressions. The assessment was characterized by the comparison of reflectance values and 34 in-situ data measurements concentrations between 1.6 and 33 mg L−1 taken from the superficial layer of the river in two campaigns. A large data set of empirical and referenced algorithm from literature were used to evaluate the accuracy and precision of the relationship. For estimation of TSS, a higher accuracy was achieved using the Tassan’s algorithm with the BAND X/ BANDX ratio. The correlation coefficient with R2 = X demonstrate the feasibility of use remote sensed data with consumed-grade cameras as an effective tool for a frequent monitoring and controlling of water quality parameters such as Total Suspended Solids of watersheds, these being the most vulnerable and less compliance with environmental regulations.
REGION-BASED 3D SURFACE RECONSTRUCTION USING IMAGES ACQUIRED BY LOW-COST UNMANNED AERIAL SYSTEMS
Authors: Lari Z. , Al-Rawabdeh A. , He F. , Habib A. , El-Sheimy N.
Published: August 2015

Abstract. Accurate 3D surface reconstruction of our environment has become essential for an unlimited number of emerging applications. In the past few years, Unmanned Aerial Systems (UAS) are evolving as low-cost and flexible platforms for geospatial data collection that could meet the needs of aforementioned application and overcome limitations of traditional airborne and terrestrial mobile mapping systems. Due to their payload restrictions, these systems usually include consumer-grade imaging and positioning sensor which will negatively impact the quality of the collected geospatial data and reconstructed surfaces. Therefore, new surface reconstruction surfaces are needed to mitigate the impact of using low-cost sensors on the final products. To date, different approaches have been proposed to for 3D surface construction using overlapping images collected by imaging sensor mounted on moving platforms. In these approaches, 3D surfaces are mainly reconstructed based on dense matching techniques. However, generated 3D point clouds might not accurately represent the scanned surfaces due to point density variations and edge preservation problems. In order to resolve these problems, a new region-based 3D surface renostruction trchnique is introduced in this paper. This approach aims to generate a 3D photo-realistic model of individually scanned surfaces within the captured images. This approach is initiated by a Semi-Global dense Matching procedure is carried out to generate a 3D point cloud from the scanned area within the collected images. The generated point cloud is then segmented to extract individual planar surfaces. Finally, a novel region-based texturing technique is implemented for photorealistic reconstruction of the extracted planar surfaces. Experimental results using images collected by a camera mounted on a low-cost UAS demonstrate the feasibility of the proposed approach for photorealistic 3D surface reconstruction.
INDICATOR SPECIES POPULATION MONITORING IN ANTARCTICA WITH UAV
Authors: Zmarz A. , Korczak-Abshire M. , Storvold R. , Rodzewicz M. , Kędzierska I.
Published: August 2015

Abstract. A program to monitor bird and pinniped species in the vicinity of Arctowski Station, King George Island, South Shetlands, Antarctica, has been conducted over the past 38 years. Annual monitoring of these indicator species includes estimations of breeding population sizes of three Pygoscelis penguin species: Adélie, gentoo and chinstrap. Six penguin colonies situated on the western shores of two bays: Admiralty and King George are investigated. To study changes in penguin populations Unmanned Aerial Vehicles were used for the first time in the 2014/15 austral summer season. During photogrammetric flights the high-resolution images of eight penguin breeding colonies were taken. Obtained high resolution images were used for estimation of breeding population size and compared with the results of measurements taken at the same time from the ground. During this Antarctic expedition eight successful photogrammetry missions (total distance 1500 km) were performed. Images were taken with digital SLR Canon 700D, Nikon D5300, Nikon D5100 with a 35mm objective lens. Flights altitude at 350 – 400 AGL, allowed images to be taken with a resolution GSD (ground sample distance) less than 5 cm. The Image J software analysis method was tested to provide automatic population estimates from obtained images. The use of UAV for monitoring of indicator species, enabled data acquisition from areas inaccessible by ground methods.
ESTIMATION OF THE SPECTRAL SENSITIVITY FUNCTIONS OF UN-MODIFIED AND MODIFIED COMMERCIAL OFF-THE-SHELF DIGITAL CAMERAS TO ENABLE THEIR USE AS A MULTISPECTRAL IMAGING SYSTEM FOR UAVS
Authors: Berra E. , Gibson-Poole S. , MacArthur A. , Gaulton R. , Hamilton A.
Published: August 2015

Abstract. Commercial off-the-shelf (COTS) digital cameras on-board unmanned aerial vehicles (UAVs) have the potential to be used as multispectral imaging systems; however, their spectral sensitivity is usually unknown and needs to be either measured or estimated. This paper details a step by step methodology for identifying the spectral sensitivity of modified (to be response to near infra-red wavelengths) and un-modified COTS digital cameras, showing the results of its application for three different models of camera. Six digital still cameras, which are being used as imaging systems on-board different UAVs, were selected to have their spectral sensitivities measured by a monochromator. Each camera was exposed to monochromatic light ranging from 370 nm to 1100 nm in 10 nm steps, with images of each step recorded in RAW format. The RAW images were converted linearly into TIFF images using DCRaw, an open-source program, before being batch processed through ImageJ (also open-source), which calculated the mean and standard deviation values from each of the red-green-blue (RGB) channels over a fixed central region within each image. These mean values were then related to the relative spectral radiance from the monochromator and its integrating sphere, in order to obtain the relative spectral response (RSR) for each of the cameras colour channels. It was found that different un-modified camera models present very different RSR in some channels, and one of the modified cameras showed a response that was unexpected. This highlights the need to determine the RSR of a camera before using it for any quantitative studies.
REMOTE SPECTRAL IMAGING USING A LOW COST UAV SYSTEM
Authors: Tsouvaltsidis C. , Zaid Al Salem N. , Benari G. , Vrekalic D. , Quine B.
Published: August 2015

Abstract. The purpose of this scientific survey is to support the research being conducted at York University in the field of spectroscopy and nanosatellites using Argus 1000 micro- spectrometer and low cost unmanned aerial vehicle (UAV) system. On the CanX-2 mission, the Argus spectrometer observes reflected infrared solar radiation emitted by Earth surface targets as small as 1.5 km within the 0.9-1.7 μm range. However, limitations in the volume of data due to onboard power constraints and a lack of an onboard camera system make it very difficult to verify these objectives using ground truth. In the last five years that Argus has been in operation, we have made over 200 observations over a series of land and ocean targets. We have recently examined algorithms to improve the geolocation accuracy of the spectrometer payload and began to conduct an analysis of soil health content using Argus spectral data. A field campaign is used to obtain data to assess geolocation accuracy using coastline crossing detection and to obtain airborne bare soil spectra in ground truth form. The payload system used for the field campaign consists of an Argus spectrometer, optical camera, GPS, and attitude sensors, integrated into a low-cost, unmanned aerial vehicle (UAV), which will be presented along with the experimental procedure and field campaign results.
COMMON APPROACH TO GEOPROCESSING OF UAV DATA ACROSS APPLICATION DOMAINS
Authors: Percivall G. S. , Reichardt M. , Taylor T.
Published: August 2015

Abstract. UAVs are a disruptive technology bringing new geographic data and information to many application domains. UASs are similar to other geographic imagery systems so existing frameworks are applicable. But the diversity of UAVs as platforms along with the diversity of available sensors are presenting challenges in the processing and creation of geospatial products. Efficient processing and dissemination of the data is achieved using software and systems that implement open standards. The challenges identified point to the need for use of existing standards and extending standards. Results from the use of the OGC Sensor Web Enablement set of standards are presented. Next steps in the progress of UAVs and UASs may follow the path of open data, open source and open standards.
POTENTIAL OF UAV BASED CONVERGENT PHOTOGRAMMETRY IN MONITORING REGENERATION STANDARDS
Authors: Vepakomma U. , Cormier D. , Thiffault N.
Published: August 2015

Abstract. Several thousand hectares of forest blocks are regenerating after harvest in Canada. Monitoring their performance over different stages of growth is critical in ensuring future productivity and ecological balance. Tools for rapid evaluation can support timely and reliable planning of interventions. Conventional ground surveys or visual image assessments are either time intensive or inaccurate, while alternate operational remote sensing tools are unavailable. In this study, we test the feasibility and strength of UAV-based photogrammetry with an EO camera on a UAV platform in assessing regeneration performance. Specifically we evaluated stocking, spatial density and height distribution of naturally growing (irregularly spaced stems) or planted (regularly spaced stems) conifer regeneration in different phases of growth. Standard photogrammetric workflow was applied on the 785 acquired images for 3D reconstruction of the study sites. The required parameters were derived based on automated single stem detection algorithm developed in-house. Comparing with field survey data, preliminary results hold promise. Future studies are planned to expand the scope to larger areas and different stand conditions.
LEAF AREA INDEX ESTIMATION IN VINEYARDS FROM UAV HYPERSPECTRAL DATA, 2D IMAGE MOSAICS AND 3D CANOPY SURFACE MODELS
Authors: Kalisperakis I. , Stentoumis Ch. , Grammatikopoulos L. , Karantzalos K.
Published: August 2015

Abstract. The indirect estimation of leaf area index (LAI) in large spatial scales is crucial for several environmental and agricultural applications. To this end, in this paper, we compare and evaluate LAI estimation in vineyards from different UAV imaging datasets. In particular, canopy levels were estimated from i.e., (i) hyperspectral data, (ii) 2D RGB orthophotomosaics and (iii) 3D crop surface models. The computed canopy levels have been used to establish relationships with the measured LAI (ground truth) from several vines in Nemea, Greece. The overall evaluation indicated that the estimated canopy levels were correlated (r2 > 73%) with the in-situ, ground truth LAI measurements. As expected the lowest correlations were derived from the calculated greenness levels from the 2D RGB orthomosaics. The highest correlation rates were established with the hyperspectral canopy greenness and the 3D canopy surface models. For the later the accurate detection of canopy, soil and other materials in between the vine rows is required. All approaches tend to overestimate LAI in cases with sparse, weak, unhealthy plants and canopy.
INVESTIGATIONS ON THE QUALITY OF THE INTERIOR ORIENTATION AND ITS IMPACT IN OBJECT SPACE FOR UAV PHOTOGRAMMETRY
Authors: Hastedt H. , Luhmann T.
Published: August 2015

Abstract. With respect to the usual processing chain in UAV photogrammetry the consideration of the camera’s influencing factors on the accessible accuracy level is of high interest. In most applications consumer cameras are used due to their light weight. They usually allow only for automatic zoom or restricted options in manual modes. The stability and long-term validity of the interior orientation parameters are open to question. Additionally, common aerial flights do not provide adequate images for self-calibration. Nonetheless, processing software include self-calibration based on EXIF information as a standard setting. The subsequent impact of the interior orientation parameters on the reconstruction in object space cannot be neglected. With respect to the suggested key issues different investigations on the quality of interior orientation and its impact in object space are addressed. On the one hand the investigations concentrate on the improvement in accuracy by applying pre-calibrated interior orientation parameters. On the other hand, image configurations are investigated that allow for an adequate self-calibration in UAV photogrammetry. The analyses on the interior orientation focus on the estimation quality of the interior orientation parameters by using volumetric test scenarios as well as planar pattern as they are commonly used in computer vision. This is done by using a Olympus Pen E-PM2 camera and a Canon G1X as representative system cameras. For the analysis of image configurations a simulation based approach is applied. The analyses include investigations on varying principal distance and principal point to evaluate the system’s stability.
UAV IMAGE BLUR – ITS INFLUENCE AND WAYS TO CORRECT IT
Authors: Sieberth T. , Wackrow R. , Chandler J. H.
Published: August 2015

Abstract. Unmanned aerial vehicles (UAVs) have become an interesting and active research topic in photogrammetry. Current research is based on image sequences acquired by UAVs which have a high ground resolution and good spectral resolution due to low flight altitudes combined with a high-resolution camera. One of the main problems preventing full automation of data processing of UAV imagery is the unknown degradation effect of blur caused by camera movement during image acquisition. The purpose of this paper is to analyse the influence of blur on photogrammetric image processing, the correction of blur and finally, the use of corrected images for coordinate measurements. It was found that blur influences image processing significantly and even prevents automatic photogrammetric analysis, hence the desire to exclude blurred images from the sequence using a novel filtering technique. If necessary, essential blurred images can be restored using information of overlapping images of the sequence or a blur kernel with the developed edge shifting technique. The corrected images can be then used for target identification, measurements and automated photogrammetric processing.
ALIGNMENT OF POINT CLOUD DSMs FROM TLS AND UAV PLATFORMS
Authors: Persad R. A. , Armenakis C.
Published: August 2015

Abstract. The co-registration of 3D point clouds has received considerable attention from various communities, particularly those in photogrammetry, computer graphics and computer vision. Although significant progress has been made, various challenges such as coarse alignment using multi-sensory data with different point densities and minimal overlap still exist. There is a need to address such data integration issues, particularly with the advent of new data collection platforms such as the unmanned aerial vehicles (UAVs). In this study, we propose an approach to align 3D point clouds derived photogrammetrically from UAV approximately vertical images with point clouds measured by terrestrial laser scanners (TLS). The method begins by automatically extracting 3D surface keypoints on both point cloud datasets. Afterwards, regions of interest around each keypoint are established to facilitate the establishment of scale-invariant descriptors for each of them. We use the popular SURF descriptor for matching the keypoints. In our experiments, we report the accuracies of the automatically derived transformation parameters in comparison to manually-derived reference parameter data.
REVIEW OF METHODS FOR DETERMINING THE SPATIAL RESOLUTION OF UAV SENSORS
Authors: Orych A.
Published: August 2015

Abstract. The ground resolved distance (GRD) of an imaging sensor, i.e. the size of the smallest element distinguishable on acquired imagery, is one of the most important sensor quality assessment factors, as it is directly linked to the amount of information that can be derived from the end product. The paper is a review of a wide variety of calibration targets used for determining the spatial resolution of remote sensing sensors. The author provides a description of calibration targets used historically and then moves on to high-frequency targets used for high-resolution remote sensing imaging equipment. As analysis is made which of these types of targets are best suited for UAV sensors, taking into account parameters very specific to UAVs: frame size, small GSD values and low flight stability.
EXPERIMENTS WITH UAS IMAGERY FOR AUTOMATIC MODELING OF POWER LINE 3D GEOMETRY
Authors: Jóźków G. , Vander Jagt B. , Toth C.
Published: August 2015

Abstract. The ideal mapping technology for transmission line inspection is the airborne LiDAR executed from helicopter platforms. It allows for full 3D geometry extraction in highly automated manner. Large scale aerial images can be also used for this purpose, however, automation is possible only for finding transmission line positions (2D geometry), and the sag needs to be estimated manually. For longer lines, these techniques are less expensive than ground surveys, yet they are still expensive. UAS technology has the potential to reduce these costs, especially if using inexpensive platforms with consumer grade cameras. This study investigates the potential of using high resolution UAS imagery for automatic modeling of transmission line 3D geometry. The key point of this experiment was to employ dense matching algorithms to appropriately acquired UAS images to have points created also on wires. This allowed to model the 3D geometry of transmission lines similarly to LiDAR acquired point clouds. Results showed that the transmission line modeling is possible with a high internal accuracy for both, horizontal and vertical directions, even when wires were represented by a partial (sparse) point cloud.
MULTI ROTOR UAV AT DIFFERENT ALTITUDES FOR SLOPE MAPPING STUDIES
Authors: Tahar K. N.
Published: August 2015

Abstract. Most of consultation work only involves a small area, especially for slope mapping studies. The objective of this study is to evaluate the accuracy of slope mapping results from different altitudes at semi-undulated area and undulated area. Multi-rotor UAV is used as an instrument for data acquisition for this study. The images of slope were captured from five different altitudes in the same study area. All images were processed using photogrammetric software to produce digital elevation models and digital orthophoto. In this study, slope map from all different altitudes were identified and recorded for analysis purposes. It was found that the accuracy of slope is increase when altitude is increase. In conclusion, the condition of slope such as semi-undulated and undulated area did have an influence on the slope accuracy.
SYMBIOSIS OF UAS PHOTOGRAMMETRY AND TLS FOR SURVEYING AND 3D MODELING OF CULTURAL HERITAGE MONUMENTS - A CASE STUDY ABOUT THE CATHEDRAL OF ST. NICHOLAS IN THE CITY OF GREIFSWALD
Authors: Grenzdörffer G. J. , Naumann M , Niemeyer F. , Frank A.
Published: August 2015

Abstract. In this contribution the possibility to combine terrestrial laser scanner (TLS) measurements and UAS photogrammetry for the detailed description and high quality surveying of a cultural monument will be illustrated by the example of the Cathedral of St. Nicholas in the city of Greifswald. Due to the different nature of UAS photogrammetry and TLS walls and windows as well as portions of roofs are captured with a different level of completeness and accuracy. The average deviations of the test areas on the overlap between the two measurement methods ranges from 0.015 m to 0.033 m with standard deviations of 0.025 m to 0.088 m.
Neogene tectonics and climate forcing of carnivora dispersals between Asia and North America
Authors: Jiang H. , Deng T. , Li Y. , Xu H.
Published: August 2015

Abstract. Exchange records of terrestrial mammals can be combined with available tectonic and climatic documents to evaluate major biological and environmental events. Previous studies identified four carnivoran dispersals between Eurasia and North America in the Neogene, namely, at ∼ 20, 13–11, 8–7, and ∼ 4 Ma. In order to evaluate driving mechanism of these biological events, we collected, compared and analyzed a large number of published records. The results indicate that the carnivoran dispersal from Eurasia to North America at ∼ 20 Ma was probably caused by intense tectonic movements in Asia. During 13–11 Ma, global cooling possibly drove the mammal exchanges between Eurasia and North America. By comparison, the carnivoran dispersal from Eurasia to North America at 8–7 Ma was probably caused by the combination of global cooling and tectonic movements of the Tibetan Plateau. Similar to during 13–11 Ma, the carnivoran exchanges between Eurasia and North America at ∼ 4 Ma were possibly driven by global cooling.
Can Plants’ Ability for DNA Repair and Stress Defense be Used against Patients’ Circulating Tumor Cells?
Authors: C.D. Volko  , U.D. Rohr
Published: August 2015

Introduction: It was suggested that specific plants may reduce cancer's resistance to chemotherapy. Resistance inhibits apoptosis, as well as other fundamental anti-cancer protective mechanisms. Soy bean has been found to reduce cellular stress and repair DNA damage caused by drought or parasites, and can transfer this defense mechanism to other plant species as well. The aim of this study is therefore to conduct a systematic comparison of the effect of soy bean formulation (FSWW08) on gene expression in in vitro human breast cancer cell line, and in in vivo in blood circulating tumor cells (CTC), after oral consumption of FSWW08 by patients suffering from breast-, ovarian-, and prostate cancer. Method: In vitro gene expressions studies were conducted with the human breast cancer cell line BT-474 that was exposed to doxorubicin or FSWW08, either alone or in combination. Ovarian-, prostate-, and breast cancer patients received FSWW08 for 30 days. CTC were extracted from their blood according to an established protocol. Gene expression evaluations were conducted before and after treatment. Results: In vitro, the multi-drug resistance (MDR) protein was reduced by FSWW08, but was increased by doxorubicin. The combination of FSWW08 and doxorubicin, however, showed a protective effect against the increase of MDR in physiologic concentrations, increased, however, also in high experimental concentrations of both agents. The expression of several cancer-related protective genes, such as tumor suppressor factors p21, p38 and p53, was improved by FSWW08 in vitro and in vivo, which helped cell differentiation and new tissue formation. Additionally, the BAX/Bcl2 ratio was improved, in vitro, as well as gene expression of estrogen receptor beta, NF-κB, MAP kinase, c-JUN, and matrix metalloproteinase 9, together with an increase of VEGF expression in vivo in CTC. Conclusion: It was demonstrated that FSWW08 improved the gene functions related to DNA repair and stress in human blood CTC and resistance marker, in vitro, when applied in combination with doxorubicin. As such, larger in vitro and in vivo clinical studies that investigate single botanical compounds from other plants, are warranted.
Acoustic shadows help gleaning bats find prey, but may be defeated by prey acoustic camouflage on rough surfaces
Authors: Clare Elizabeth L , Holderied Marc W
Published: August 2015

Perceptual abilities of animals, like echolocating bats, are difficult to study because they challenge our understanding of non-visual senses. We used novel acoustic tomography to convert echoes into visual representations and compare these cues to traditional echo measurements. We provide a new hypothesis for the echo-acoustic basis of prey detection on surfaces. We propose that bats perceive a change in depth profile and an ‘acoustic shadow’ cast by prey. The shadow is more salient than prey echoes and particularly strong on smooth surfaces. This may explain why bats look for prey on flat surfaces like leaves using scanning behaviour. We propose that rather than forming search images for prey, whose characteristics are unpredictable, predators may look for disruptions to the resting surface (acoustic shadows). The fact that the acoustic shadow is much fainter on rougher resting surfaces provides the first empirical evidence for ‘acoustic camouflage’ as an anti-predator defence mechanism.
An ancient Pygo-dependent Wnt enhanceosome integrated by Chip/LDB-SSDP
Authors: Fiedler Marc , Graeb Michael , Mieszczanek Juliusz , Rutherford Trevor J , Johnson Christopher M , Bienz Mariann
Published: August 2015

TCF/LEF factors are ancient context-dependent enhancer-binding proteins that are activated by β-catenin following Wnt signaling. They control embryonic development and adult stem cell compartments, and their dysregulation often causes cancer. β-catenin-dependent transcription relies on the NPF motif of Pygo proteins. Here, we use a proteomics approach to discover the Chip/LDB-SSDP (ChiLS) complex as the ligand specifically binding to NPF. ChiLS also recognizes NPF motifs in other nuclear factors including Runt/RUNX2 and Drosophila ARID1, and binds to Groucho/TLE. Studies of Wnt-responsive dTCF enhancers in the Drosophila embryonic midgut indicate how these factors interact to form the Wnt enhanceosome, primed for Wnt responses by Pygo. Together with previous evidence, our study indicates that ChiLS confers context-dependence on TCF/LEF by integrating multiple inputs from lineage and signal-responsive factors, including enhanceosome switch-off by Notch. Its pivotal function in embryos and stem cells explain why its integrity is crucial in the avoidance of cancer.
NUDT21-spanning CNVs lead to neuropsychiatric disease and altered MeCP2 abundance via alternative polyadenylation
Authors: Gennarino Vincenzo A , Alcott Callison E , Chen Chun-An , Chaudhury Arindam , Gillentine Madelyn A , Rosenfeld Jill A , Parikh Sumit , Wheless James W , Roeder Elizabeth R , Horovitz Dafne DG , Roney Erin K , Smith Janice L , Cheung Sau W , Li Wei , Neilson Joel R , Schaaf Christian P , Zoghbi Huda Y
Published: August 2015

The brain is sensitive to the dose of MeCP2 such that small fluctuations in protein quantity lead to neuropsychiatric disease. Despite the importance of MeCP2 levels to brain function, little is known about its regulation. In this study, we report eleven individuals with neuropsychiatric disease and copy-number variations spanning NUDT21, which encodes a subunit of pre-mRNA cleavage factor Im. Investigations of MECP2 mRNA and protein abundance in patient-derived lymphoblastoid cells from one NUDT21 deletion and three duplication cases show that NUDT21 regulates MeCP2 protein quantity. Elevated NUDT21 increases usage of the distal polyadenylation site in the MECP2 3′ UTR, resulting in an enrichment of inefficiently translated long mRNA isoforms. Furthermore, normalization of NUDT21 via siRNA-mediated knockdown in duplication patient lymphoblasts restores MeCP2 to normal levels. Ultimately, we identify NUDT21 as a novel candidate for intellectual disability and neuropsychiatric disease, and elucidate a mechanism of pathogenesis by MeCP2 dysregulation via altered alternative polyadenylation.
Standard osteopathic manipulative treatment acutely improves gait performance in patients with Parkinson's disease
Authors: Wells Michael R. , Giantinoto Sal , D’agate David , Areman R D , Fazzini Enrico A , Dowling Dennis , Bosak Andrew
Published: August 2015

Patients with Parkinson's disease exhibit a variety of motor deficits which can ultimately result in complete disability. The primary objective of this study was toquantitatively evaluate the effect of osteopathic manipulative treatment (OMT)on the gait of patients with Parkinson's disease. Ten patients with idiopathicParkinson's disease and a group of eight age-matched normal control subjects ~eresubjected to an analysis of gait before and after a single session of an OMT protocol. A separate group of 10 patients with Parkinson's disease was given asham-control procedure and tested in the same manner. In the treated group ofpatients with Parkinson's disease, statistically significant increases were observedin stride length, cadence, and the maximum velocities of upper and lower extremitiesafter treatment. There were no significant differences observed in the controlgroups. The data demonstrate that a single session of an OMT protocol hasan immediate impact on Parkinsonian gait. Osteopathic manipulation may be aneffective physical treatment method in the management of movement deficits inpatients with Parkinson's disease.
A solar escalator on Mars: Self‐lifting of dust layers by radiative heating
Authors: Daerden F. , Whiteway J. A. , Neary L. , Komguem L. , Lemmon M. T. , Heavens N. G. , Cantor B. A. , Hébrard E. , Smith M. D.
Published: August 2015

Dust layers detected in the atmosphere of Mars by the light detection and ranging (LIDAR) instrument on the Phoenix Mars mission are explained using an atmospheric general circulation model. The layers were traced back to observed dust storm activity near the edge of the north polar ice cap where simulated surface winds exceeded the threshold for dust lifting by saltation. Heating of the atmospheric dust by solar radiation caused buoyant instability and mixing across the top of the planetary boundary layer (PBL). Differential advection by wind shear created detached dust layers above the PBL that ascended due to radiative heating and arrived at the Phoenix site at heights corresponding to the LIDAR observations. The self‐lifting of the dust layers is similar to the “solar escalator” mechanism for aerosol layers in the Earth's stratosphere.
Stereoselective Total Synthesis of Myriocin Using Rhodium(II)‐Catalyzed C−H Amination Followed by Alkylation
Authors: Nambu Hisanori , Noda Narumi , Niu Wenqi , Fujiwara Tomoya , Yakura Takayuki
Published: August 2015

The stereoselective total synthesis of myriocin was achieved by using the Du Bois RhII‐catalyzed C−H amination of sulfamate 6, derived from diethyl l‐tartrate, and a subsequent alkylation. The reaction of sulfamate 6 with PhI(OAc)2 and MgO in the presence of Rh2(OAc)4 gave an oxathiazinane N,O‐acetal as the sole product in high yield. Alkylation of the N,O‐acetal with vinylmagnesium bromide in the presence of ZnCl2 proceeded stereoselectively to provide an oxathiazinane bearing a quaternary chiral center in high yield. This route includes the first application of the Du Bois procedure for the construction of a quaternary chiral center.
Charge and Spin Transport in an Organic Molecular Square
Authors: Wu Yilei , Nalluri Siva Krishna Mohan , Young Ryan M. , Krzyaniak Matthew D. , Margulies Eric A. , Stoddart J. Fraser , Wasielewski Michael R.
Published: August 2015

Understanding electronic communication among multiple chromophoric and redox units requires construction of well‐defined molecular architectures. Herein, we report the modular synthesis of a shape‐persistent chiral organic square composed of four naphthalene‐1,8:4,5‐bis(dicarboximide) (NDI) sides and four trans‐1,2‐cyclohexanediamine corners. Single crystal X‐ray diffraction reveals some distortion of the cyclohexane chair conformation in the solid state. Analysis of the packing of the molecular squares reveals the formation of highly ordered, one‐dimensional tubular superstructures, held together by means of multiple [CH⋅⋅⋅OC] hydrogen‐bonding interactions. Steady‐state and time‐resolved electronic spectroscopies show strong excited‐state interactions in both the singlet and triplet manifolds. Electron paramagnetic resonance (EPR) and electron‐nuclear double resonance (ENDOR) spectroscopies on the monoreduced state reveal electron sharing between all four NDI subunits comprising the molecular square.
A Highly Stable and Magnetically Recyclable Nanocatalyst System: Mesoporous Silica Spheres Embedded with FeCo/Graphitic Shell Magnetic Nanoparticles and Pt Nanocatalysts
Authors: Kim Da Jeong , Li Yan , Kim Yun Jin , Hur Nam Hwi , Seo Won Seok
Published: August 2015

We have developed a highly stable and magnetically recyclable nanocatalyst system for alkene hydrogenation. The materials are composed of mesoporous silica spheres (MSS) embedded with FeCo/graphitic shell (FeCo/GC) magnetic nanoparticles and Pt nanocatalysts (Pt‐FeCo/GC@MSS). The Pt‐FeCo/GC@MSS have superparamagnetism at room temperature and show type IV isotherm typical for mesoporous silica, thereby ensuring a large enough inner space (surface area of 235.3 m2 g−1, pore volume of 0.165 cm3 g−1, and pore diameter of 2.8 nm) to undergo catalytic reactions. We have shown that the Pt‐FeCo/GC@MSS system readily converts cyclohexene into cyclohexane, which is the only product isolated and Pt‐FeCo/GC@MSS can be seperated very quickly by an external magnetic field after the catalytic reaction is finished. We have demonstrated that the recycled Pt‐FeCo/GC@MSS can be reused further for the same hydrogenation reaction at least four times without loss in the initial catalytic activity.
Exploring the Conformational Space of Bridge‐Substituted Dithienylcyclopentenes
Authors: Fredersdorf Maic , Göstl Robert , Kolmer Andreas , Schmidts Volker , Monecke Peter , Hecht Stefan , Thiele Christina M.
Published: August 2015

Stimuli responsive compounds and materials are of high interest in synthetic chemistry and materials science, with light being the most intriguing stimulus due to the possibility to remote control the physicochemical properties of a molecule or a material. There is a constant quest to design photoswitches with improved switching efficiency and especially diarylethene‐type switches promise photo cyclization quantum yields up to unity. However, only limited attention has been paid towards the influence of the solution conformation on the switching efficiency. Here, we describe a detailed NMR spectroscopic investigation on the conformational distribution of bridge‐substituted dithienylcyclopentenes in solution. We could discriminate between several photoactive and photoinactive as well as two diastereomorphous conformations and show that the trends observed in the switching efficiency match the conformer populations obtained from state of the art NMR parameters in solution.
Unusual Cyclodextrin Derivatives as a New Avenue to Modulate Self‐ and Metal‐Induced Aβ Aggregation
Authors: Oliveri Valentina , Bellia Francesco , Pietropaolo Adriana , Vecchio Graziella
Published: August 2015

Mounting evidence suggests an important role of cyclodextrins in providing protection in neurodegenerative disorders. Metal dyshomeostasis is reported to be a pathogenic factor in neurodegeneration because it could be responsible for damage involving oxidative stress and protein aggregation. As such, metal ions represent an effective target. To improve the metal‐binding ability of cyclodextrin, we synthesized three new 8‐hydroxyquinoline‐cyclodextrin conjugates with difunctionalized cyclodextrins. In particular, the 3‐difunctionalized regioisomer represents the first example of cyclodextrin with two pendants at the secondary rim, resulting in a promising compound. The derivatives have significant antioxidant capacity and the powerful activity in inhibiting self‐induced amyloid‐β aggregation seems to be led by synergistic effects of both cyclodextrin and hydroxyquinoline. Moreover, the derivatives are also able to complex metal ions and to inhibit metal‐induced protein aggregation. Therefore, these compounds could have potential as therapeutic agents in diseases related to protein aggregation and metal dyshomeostasis.
Hydrogen‐Bonding‐Mediated Synthesis of Atomically Thin TiO2 Films with Exposed (001) Facets and Applications in Fast Lithium Insertion/Extraction
Authors: Zhang Hongye , Yang Zhenzhen , Gan Wei , Zhao Yanfei , Yu Bo , Xu Huanjun , Ma Zhishuang , Hao Leiduan , Chen Dechao , Miao Shiding , Liu Zhimin
Published: August 2015

Ultrathin two‐dimensional (2D) crystalline materials show high specific surface area (SA) of high energy (HE) facets, imparting a significant improvement in their performances. Herein we report a novel route to synthesize TiO2 nanofilms (NFs) with atomic thickness (<2.0 nm) through a solvothermal reaction mediated by the hydrogen‐bonding networks constructed by hydroquinone (HQ). The resultant TiO2 NFs have nearly 100 % exposed (001) facets and give an extremely high SA up to 487 m2 g−1. The synergistic effect of HQ and choline chloride plays a vital role in the formation of TiO2 NFs and in the exposure of HE (001) facets. Because of its ultrathin feature and exposed (001) facet, the N2‐annealled TiO2 NFs showed fast kinetics of lithium insertion/extraction, demonstrating foreseeable applications in the energy storage.
Role of phenotypic plasticity and population differentiation in adaptation to novel environmental conditions
Authors: Volis Sergei , Ormanbekova Danara , Yermekbayev Kanat
Published: August 2015

Species can adapt to new environmental conditions either through individual phenotypic plasticity, intraspecific genetic differentiation in adaptive traits, or both. Wild emmer wheat, Triticum dicoccoides, an annual grass with major distribution in Eastern Mediterranean region, is predicted to experience in the near future, as a result of global climate change, conditions more arid than in any part of the current species distribution. To understand the role of the above two means of adaptation, and the effect of population range position, we analyzed reaction norms, extent of plasticity, and phenotypic selection across two experimental environments of high and low water availability in two core and two peripheral populations of this species. We studied 12 quantitative traits, but focused primarily on the onset of reproduction and maternal investment, which are traits that are closely related to fitness and presumably involved in local adaptation in the studied species. We hypothesized that the population showing superior performance under novel environmental conditions will either be genetically differentiated in quantitative traits or exhibit higher phenotypic plasticity than the less successful populations. We found the core population K to be the most plastic in all three trait categories (phenology, reproductive traits, and fitness) and most successful among populations studied, in both experimental environments; at the same time, the core K population was clearly genetically differentiated from the two edge populations. Our results suggest that (1) two means of successful adaptation to new environmental conditions, phenotypic plasticity and adaptive genetic differentiation, are not mutually exclusive ways of achieving high adaptive ability; and (2) colonists from some core populations can be more successful in establishing beyond the current species range than colonists from the range extreme periphery with conditions seemingly closest to those in the new environment.
Fuel moisture content enhances nonadditive effects of plant mixtures on flammability and fire behavior
Authors: Blauw Luke G. , Wensink Niki , Bakker Lisette , van Logtestijn Richard S. P. , Aerts Rien , Soudzilovskaia Nadejda A. , Cornelissen J. Hans C.
Published: August 2015

Fire behavior of plant mixtures includes a complex set of processes for which the interactive contributions of its drivers, such as plant identity and moisture, have not yet been unraveled fully. Plant flammability parameters of species mixtures can show substantial deviations of fire properties from those expected based on the component species when burnt alone; that is, there are nonadditive mixture effects. Here, we investigated how fuel moisture content affects nonadditive effects in fire behavior. We hypothesized that both the magnitude and variance of nonadditivity in flammability parameters are greater in moist than in dry fuel beds. We conducted a series of experimental burns in monocultures and 2‐species mixtures with two ericaceous dwarf shrubs and two bryophyte species from temperate fire‐prone heathlands. For a set of fire behavior parameters, we found that magnitude and variability of nonadditive effects are, on average, respectively 5.8 and 1.8 times larger in moist (30% MC) species mixtures compared to dry (10% MC) mixed fuel beds. In general, the moist mixtures caused negative nonadditive effects, but due to the larger variability these mixtures occasionally caused large positive nonadditive effects, while this did not occur in dry mixtures. Thus, at moister conditions, mixtures occasionally pass the moisture threshold for ignition and fire spread, which the monospecific fuel beds are unable to pass. We also show that the magnitude of nonadditivity is highly species dependent. Thus, contrary to common belief, the strong nonadditive effects in mixtures can cause higher fire occurrence at moister conditions. This new integration of surface fuel moisture and species interactions will help us to better understand fire behavior in the complexity of natural ecosystems.
Affecting the Catalytic Activity of the Known [Ru(tpy)(bpy)(OH2)]2+ Complex in Water Oxidation by Utilization of a Hangman Ligand
Authors: Wrzolek Pierre , Schwalbe Matthias
Published: August 2015

[Ru(tpy)(bpy)(OH2)]2+ (bpy = 2,2′‐bipyridine, tpy = 2,2′;6′,2″‐terpyridine) is the archetype of many known single‐site ruthenium complexes used for catalytic water oxidation. Its efficiency is likely influenced by installing a proton‐donor/acceptor functionality in proximity to the catalytic site because the reaction mechanism is believed to occur by nucleophilic attack of a water molecule on a high‐valent metal–oxo species assisted by hydrogen‐bonding interactions. We present herein the results of a study of a new metal complex based on the “hangman” motif that possesses a carboxylic functional group close to the ruhenium center. This catalyst was synthesized in very good yield and fully characterized. We discovered that its catalytic activity was in fact hampered by the presence of the functional group. Further investigations revealed a strong dependence of the catalytic performance not only on the solvent, but also on the counter ion and other additives used.