Seasonal and interannual ice velocity changes of Polar Record Glacier, East Antarctica

We present a study of seasonal and interannual ice velocity changes at Polar Record Glacier, East Antarctica, using ERS-1/2, Envisat and PALSAR data with D-InSAR and intensity tracking. Ice flow showed seasonal variations at the front of the glacier tongue. Velocities in winter were 19% less than velocities during summer. No significant interannual changes were detected. Ice velocities in the grounding zone and grounded glacier did not show clear seasonal or interannual changes. The distributio of the seasonal variations suggests that the cause for the changes should be localized. Possible causes are seasonal sea-ice changes and iceberg blocking. Satellite images show that the sea ice surrounding Polar Record Glacier undergoes seasonal changes. Frozen sea ice in winter slowed the huge iceberg, and provided increased resistance to the glacier flow. The interaction between the glacier tongue, ice berg and sea ice significantly influences their flow pattern

Elevation determination of nunataks in the Grove Mountains

A majority of the exposed nunataks located in the Grove Mountains of the Antarctic interior have yet to have had their elevations measured. The elevations of Mason Peak and Wilson Ridge were precisely determined by the Grove Team of the 26th CHINARE in 2010, with Mason Peak turning out to be the highest of the Grove Mountains. Considering that both Mason Peak and Wilson Ridge are difficult to climb because of their cragginess, we first selected three control points on the ice surface near Mason Peak and positioned them with GPS. Thus, accurate elevations of Mason Peak and Wilson Ridge could be calculated from three directions using forward intersection and trigonometric leveling of a high-precision theodolite at the chosen control points. The results provide basic geodetic information that can be referred to as high-precision control points for surveying and mapping in this part of Antarctica. This paper elaborates on the process of measurement and computation of the mountains summit elevations, and also analyzes the details of the principal elements influencing the accuracy of trigonometric leveling, the determination of refraction coefficients k, and observations of structure and distance

GPR Surveying in the kernel area of Grove Mountains, Antarctica

The Grove Mountains, located between the Zhongshan Station and Dome A, are a very important area in inland Antarctic research. China has organized five investigations of the Grove Mountains, encompassing the geological structure, ancient climate, meteorites, ice-movement monitoring, basic mapping, meteorological observations, and other multi-disciplinary observational studies. During the 26th Chinese National Antarctic Research Expedition in 2010, the Grove Mountains investigation team applied specialized ground-penetrating radar (GPR) to survey subglacial topography in the eastern kernel area of the Grove Mountains. In this paper, we processed GPS and GPR data gathered in the field and drew, for the first time, two subglacial topographic maps of the Grove Mountains kernel area using professional graphics software. The preliminary results reveal the mystery of the nunatak landform of this area, give an exploratory sense of the real bedrock landforms, and indicate a possible sedimentary basin under the Pliocene epoch fossil ice in the Grove Mountains area. Additionally, it has been proven from cross-sectional analysis between Mount Harding and the Zakharoff ridge that the box-valley shape between two nunataks has already matured

Vulto-van Silfhout-de Vries syndrome caused by de novo variants of DEAF1 gene: a case report and literature review

Vulto-van Silfhout-de Vries syndrome (VSVS; MIM 615828) is an extremely rare autosomal dominant disorder with unknown incidence. It is always caused by de novo heterozygous pathogenic variants in the DEAF1 gene, which encodes deformed epidermal autoregulatory factor-1 homology. VSVS is characterized by mild to severe intellectual disability (ID) and/or global developmental delay (GDD), seriously limited language expression, behavioral abnormalities, somnipathy, and reduced pain sensitivity. In this study, we present a Chinese boy with moderate GDD and ID, severe expressive language impairment, behavioral issues, autism spectrum disorder (ASD), sleeping dysfunction, high pain threshold, generalized seizures, imbalanced gait, and recurrent respiratory infections as clinical features. A de novo heterozygous pathogenic missense variant was found in the 5th exon of DEAF1 gene, NM_021008.4 c.782G>C (p. Arg261Pro) variant by whole exome sequencing (WES). c.782G>C had not been previously reported in genomic databases and literature. According to the ACMG criteria, this missense variant was considered to be “Likely Pathogenic”. We diagnosed the boy with VSVS both genetically and clinically. At a follow-up of 2.1 years, his seizures were well controlled after valproic acid therapy. In addition, the child’s recurrent respiratory infections improved at 3.5 years of age, which has not been reported in previous individuals. Maybe the recurrent respiratory infections like sleep problems reported in the literature are not permanent but may improve naturally over time. The literature review showed that there were 35 individuals with 28 different de novo pathogenic variants of DEAF1-related VSVS. These variants were mostly missense and the clinical manifestations were similar to our patient. Our study expands the genotypic and phenotypic profiles of de novo DEAF1

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

How long will an Arctic mountain glacier survive? A case study of Austre Lovénbreen, Svalbard

To study Arctic valley glacier responses to global climate change, the Elmer/Ice ice-flow model was used to investigate long-term changes in Austre Lovénbreen, a typical polythermal glacier in Svalbard. Evolution and features, including volume, area, ice thickness, runoff and time and mode of glacier disappearance, were projected. Firstly, steady-state simulations were performed to determine the best parameters for the ice-flow model, which were then used to simulate glacial dynamics. Based on the 21st-century Arctic warming trend in the fifth assessment report published by the Intergovernmental Panel on Climate Change, the evolution of the glacier was simulated under three hypothetical climatic scenarios: pessimistic, high-probability and optimistic. The results predicted that the glacier will retreat until disappearance under all three scenarios, and its disappearance time will likely be approximately 111 years (by 2120). Under all scenarios, glacier volume and area reductions will be slow at first, then fast and finally slow again at the end. In particular, glacial runoff will increase markedly until 2070 in the high-probability scenario, and the peak runoff will be double the current value

The Effects of Nitrogen Addition on the Uptake and Allocation of Macro- and Micronutrients in Bothriochloa ischaemum on Loess Plateau in China

The effects of nitrogen (N) addition on the macro- and micronutrient concentrations, storage, and allocation of Bothriochloa ischaemum (L.) Keng, a native forage plant on the Loess Plateau in China remain unclear. We studied the effects of N addition at 0 (CK), 2.5 (N1), 5.0 (N2), and 10.0 (N3) g N m-2 y-1. N addition significantly decreased the available copper (Cu), zinc (Zn), and total Cu concentration, but significantly increased the available iron concentration in the soil. Cu, manganese (Mn), and sodium (Na) concentrations in aboveground tissues and potassium (K), magnesium, and Zn concentrations in belowground tissues significantly increased with N addition. Calcium (Ca) concentrations in belowground tissues decreased significantly. The ratios of above- to belowground Ca, Cu, Zn, and Mn significantly increased with N addition. The maximum ratios appeared at N2 for Cu, Zn, and Mn. The aboveground, belowground, and total biomass storage of studied nutrients significantly changed with N addition, and most attained maximum values under N2 treatment. The storage ratios of above- to belowground Cu, Zn, Mn, and Na attained maximum values at N2. We conclude that N addition significantly, but differentially influence the macro- and micronutrient concentrations and storage in B. ischaemum. B. ischaemum allocated and accumulated increased macro- and micronutrients to its aboveground tissues and exhibited high total storage when the amount of N addition reached 5 g N m-2 y-1

Topographic survey on the surface of glacier Austre Lovénbreen and Pedersenbreen in Svalbard based on GPS method

Since 2005, the Chinese Arctic National Research Expedition (CHINARE) has carried out highly precise GPS Measurements on two glaciers, Austre Lovénbreen and Pedersenbreen near the Chinese Arctic Yellow River station, Acquiring precise locations of observation poles on the two glaciers. In April 2009, CHINARE acquired high density GPS point positioning data on the two glaciers with a Novatel SMART-V1 GPS instrument, which is an integrated Single frequency GPS receiver. This paper introduced the field work of the topographic survey ingusing the SMART-V1 GPS, analyzed the possibility of using single frequency GPS point positioning data for topographic surveying on glaciers, and acquired the digital elevation model of the glaciers’surface. Contour lines were then produced in Arcmapand the contour data exported into Corel Draw formapping. The precision of the adjusted GPS point positioning data reach 0.78m apart from altitude.This is less than the altitude change in seasonal wave and the year round melting. As a widely used componentin the pulse EKKOGPR, theSMART-V1GPS receiver is capable of Topographic surveying on glaciers, and the data processing method in this paper is of use to similar studies. Full text in Chinese only