A molecular–morphological approach solves taxonomic controversy in arctic Draba (Brassicaceae)

2002 ◽  
Vol 80 (1) ◽  
pp. 59-71 ◽  
Author(s):  
Anne-Cathrine Scheen ◽  
Reidar Elven ◽  
Christian Brochmann
Keyword(s):  
Large Population ◽  
Genotypic Diversity ◽  
Morphological Characters ◽  
Conclusive Evidence ◽  
The Arctic ◽  
Data Sets ◽  
Morphological Approach ◽  
Isozyme Loci ◽  
Autogamous Species

We used a combined molecular and morphological approach to solve a long-term controversy in the taxonomically complex genus Draba L. (Brassicaceae): the delimitation of Draba lactea Adams versus Draba fladnizensis Wulfen. We also tested hypotheses on the origin of D. lactea, which has been reported as hexaploid and possibly derived from the diploids D. fladnizensis, Draba nivalis Liljeblad, and (or) Draba subcapitata Simmons. In an initial analysis of large population samples of three of these autogamous species, intrapopulational isozyme variation was low or absent (mean genotypic diversity, D, was 0.10), the diploids were almost invariably homozygous, and D. lactea was highly fixed-heterozygous. In the main analysis, we examined 35–47 populations of the four tentative species from the arctic archipelago of Svalbard for variation in isozymes, random amplified polymorphic DNAs (RAPDs), and 36 morphological characters. Multivariate analyses of the RAPD data revealed four very distinct groups of multilocus phenotypes. These groups also differed in several morphological characters and corresponded to the four tentative species. The species were less differentiated at isozyme loci, in particular the diploids D. fladnizensis and D. subcapitata, but D. lactea was clearly distinguished from D. fladnizensis based on all three data sets. Contrary to most earlier suggestions, the hexaploid D. lactea was genetically more similar to D. subcapitata than to D. nivalis, but our analyses of the material from Svalbard did not give conclusive evidence on the origin of this widespread arctic hexaploid.Key words: arctic, Draba, isozymes, morphology, polyploidy, RAPDs.

scholarly journals Aerial survey and telemetry data analysis of a peripheral caribou calving area in northwestern Alaska

Rangifer ◽  
2019 ◽  
Vol 39 (1) ◽  
pp. 43-58
Author(s):  
Alexander K. Prichard ◽  
Ryan L. Klimstra ◽  
Brian T. Person ◽  
Lincoln S. Parrett
Keyword(s):  
Industrial Development ◽  
Rangifer Tarandus ◽  
Aerial Survey ◽  
The Arctic ◽  
Primary Data ◽  
Data Sets ◽  
Telemetry Data ◽  
Western Arctic ◽  
Data Source

With industrial development expanding in the Arctic, there is increasing interest in quantifying the impacts of development projects on barren ground caribou (Rangifer tarandus granti). The primary data source to assess caribou distribution and predict impacts in remote areas of Alaska has shifted in recent decades from aerial survey data to telemetry data, but these techniques have different strengths and weaknesses. The ranges of two caribou herds, the Western Arctic Herd and the Teshekpuk Herd, overlap in northwest Alaska between Wainwright and Atqasuk, Alaska. Based on long-term telemetry data sets, this region was thought to be outside of the core calving ranges of both herds. Calving has long been reported to occur in this general area, but early reports assumed caribou were from the Western Arctic Herd and only one systematic aerial survey of caribou density and distribution during calving has been conducted in this area in recent decades. Following interest in industrial development in this area, we conducted aerial strip-transect surveys during early to mid-June 2013–2015 to directly assess the density and distribution of caribou in the area and we used existing telemetry data to compare our results to the seasonal distribution of both herds. Total caribou densities varied between 0.36 and 1.06 caribou/km² among years, and calf densities varied 0.04 and 0.25 calves/km² among years. Contrary to assumptions by early researchers in the area, telemetry data indicated that caribou in this area during early to mid-June were from the Teshekpuk Herd. The use of telemetry data alone underestimated the importance of this area for calving, but the combination of aerial surveys and telemetry data provided complementary information on caribou use of this area showing the importance of collecting the appropriate types of data for assessing potential impacts of development on caribou.

scholarly journals Revising the retrieval technique of a long-term stratospheric HNO<sub>3</sub> data set: from a constrained matrix inversion to the optimal estimation algorithm

2011 ◽  
Vol 29 (7) ◽  
pp. 1317-1330 ◽  
Author(s):  
I. Fiorucci ◽  
G. Muscari ◽  
R. L. de Zafra
Keyword(s):  
Optimal Estimation ◽  
Matrix Inversion ◽  
The Arctic ◽  
Inversion Method ◽  
Data Sets ◽  
Vertical Profiles ◽  
Mixing Ratio ◽  
Data Set ◽  
The Antarctic

Abstract. The Ground-Based Millimeter-wave Spectrometer (GBMS) was designed and built at the State University of New York at Stony Brook in the early 1990s and since then has carried out many measurement campaigns of stratospheric O3, HNO3, CO and N2O at polar and mid-latitudes. Its HNO3 data set shed light on HNO3 annual cycles over the Antarctic continent and contributed to the validation of both generations of the satellite-based JPL Microwave Limb Sounder (MLS). Following the increasing need for long-term data sets of stratospheric constituents, we resolved to establish a long-term GMBS observation site at the Arctic station of Thule (76.5° N, 68.8° W), Greenland, beginning in January 2009, in order to track the long- and short-term interactions between the changing climate and the seasonal processes tied to the ozone depletion phenomenon. Furthermore, we updated the retrieval algorithm adapting the Optimal Estimation (OE) method to GBMS spectral data in order to conform to the standard of the Network for the Detection of Atmospheric Composition Change (NDACC) microwave group, and to provide our retrievals with a set of averaging kernels that allow more straightforward comparisons with other data sets. The new OE algorithm was applied to GBMS HNO3 data sets from 1993 South Pole observations to date, in order to produce HNO3 version 2 (v2) profiles. A sample of results obtained at Antarctic latitudes in fall and winter and at mid-latitudes is shown here. In most conditions, v2 inversions show a sensitivity (i.e., sum of column elements of the averaging kernel matrix) of 100 ± 20 % from 20 to 45 km altitude, with somewhat worse (better) sensitivity in the Antarctic winter lower (upper) stratosphere. The 1σ uncertainty on HNO3 v2 mixing ratio vertical profiles depends on altitude and is estimated at ~15 % or 0.3 ppbv, whichever is larger. Comparisons of v2 with former (v1) GBMS HNO3 vertical profiles, obtained employing the constrained matrix inversion method, show that v1 and v2 profiles are overall consistent. The main difference is at the HNO3 mixing ratio maximum in the 20–25 km altitude range, which is smaller in v2 than v1 profiles by up to 2 ppbv at mid-latitudes and during the Antarctic fall. This difference suggests a better agreement of GBMS HNO3 v2 profiles with both UARS/ and EOS Aura/MLS HNO3 data than previous v1 profiles.

Advances in the HadCRUT5 record of global near-surface temperatures since 1850

2021 ◽  
Author(s):  
Colin Morice ◽  
John Kennedy ◽  
Nick Rayner ◽  
Jonathan Winn ◽  
Emma Hogan ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Measurement Errors ◽  
Global Climate ◽  
The Arctic ◽  
Data Sets ◽  
Observation Data ◽  
Data Set ◽  
Near Surface ◽  
Temperature Records

&lt;p&gt;The new HadCRUT5 data set combines meteorological station air temperature records with sea-surface temperature measurements in a data set of near-surface temperature anomalies from the year 1850 to present. Major developments in HadCRUT5 include: updates to underpinning observation data holdings; use of an updated assessment of the impacts of changing marine measurement methods; and adoption of a statistical gridding method to extend estimates into sparsely observed regions of the globe, such as the Arctic. The data are presented as a 200-member ensemble that spans the assessed uncertainty associated with adjustments for long-term observational biases, observing platform measurement errors and the interaction of observational sampling with gridding methods. The impacts of methodological changes in HadCRUT5 on diagnostics of the global climate will be discussed and compared to results derived from other state-of-the-art global data sets.&lt;/p&gt;

Diatoms and aquatic palynomorphs in the sediments of the Eurasian Arctic seas and their significance for paleooceanological investigations in the Arctic

2019 ◽  
pp. 246-251
Author(s):  
Yelena I. Polyakova ◽  
Yekaterina I. Novichkova ◽  
Tatiana S. Klyuvitkina ◽  
Elizaveta A. Agafonova ◽  
Irina M. Kryukova
Keyword(s):  
Bering Sea ◽  
Surface Sediments ◽  
Sea Water ◽  
The Arctic ◽  
Marginal Filter ◽  
Arctic Seas ◽  
Hydrological Parameters ◽  
The Arctic Ocean ◽  
Long Term Studies

Presented the results of long-term studies of diatoms and aquatic palynomorphs in surface sediments of the Arctic seas and the possibility of their use for the reconstructions of paleocirculation water masses, advection of Atlantic and Bering sea water into the Arctic ocean, changes in the river runoff to the seas, sedimentary processes in the marginal filter of the largest rivers, seasonal sea ice cover and other hydrological parameters.

A remarkable pogonophoran from a desalted shallow near the mouth of the Yenisey River in the Kara Sea, with the description of a new species of the genus Galathealinum (Annelida: Pogonophora: Frenulata)

2020 ◽  
Vol 29 (1) ◽  
pp. 138-154
Author(s):  
R.V. Smirnov ◽  
O.V. Zaitseva ◽  
A.A. Vedenin
Keyword(s):  
New Species ◽  
Arctic Ocean ◽  
Anterior Part ◽  
Morphological Characters ◽  
Kara Sea ◽  
The Arctic ◽  
External Layer ◽  
The Arctic Ocean ◽  
A New Species ◽  
Unusual Finding

A new species of Pogonophora obtained from one station at a depth of 25 m from near the Dikson Island in the Kara Sea is described. Galathealinum karaense sp. nov. is one of the largest pogonophorans, the first known representative of the rare genus Galathealinum Kirkegaard, 1956 in the Eurasian part of the Arctic Ocean and a highly unusual finding for the desalted shallow of the Yenisey Gulf. Several characters occurring in the new species are rare or unique among the congeners: under-developed, hardly discernible frills on the tube segments, extremely thin felted fibres in the external layer of the tube, and very faintly separated papillae in the anterior part of the trunk. Morphological characters useful in distinguishing species within the genus Galathealinum are defined and summarised in a table. Diagnosis of the genus Galathealinum is emended and supplemented by new characters. Additionally, three taxonomic keys are provided to the species of Galathealinum and to the known species of the Arctic pogonophorans using either animals or their empty tubes only, with the brief zoogeographical information on each Arctic species.

Trends and Prospects of Development of the Oil and Gas Sector in the Context of Digitalization

2020 ◽  
Vol 26 (1) ◽  
pp. 35-45 ◽  
Author(s):  
A. G. Kazanin
Keyword(s):  
Oil And Gas ◽  
Digital Technologies ◽  
Oil And Gas Industry ◽  
Global Market ◽  
The Arctic ◽  
Business And Society ◽  
Gas Industry ◽  
Exploration And Production ◽  
Oil And Gas Sector

The modern oil and gas industry is heavily dependent on the processes and trends driven by the accelerating digitalization of the economy. Thus, the digitalization of the oil and gas sector has become Russia’s top priority, which involves a technological and structural transformation of all production processes and stages.Aim. The presented study aims to identify the major trends and prospects of development of the Russian oil and gas sector in the context of its digitalization and formation of the digital economy.Tasks. The authors analyze the major trends in the development of the oil and gas industry at a global scale and in Russia with allowance for the prospects of accelerated exploration of the Arctic; determine the best practices of implementation of digital technologies by oil and gas companies as well as the prospects and obstacles for the subsequent transfer of digital technologies to the Russian oil and gas industry.Methods. This study uses general scientific methods, such as analysis, synthesis, and scientific generalization.Results. Arctic hydrocarbons will become increasingly important to Russia in the long term, and their exploration and production will require the implementation of innovative technologies. Priority directions for the development of many oil and gas producers will include active application of digital technologies as a whole (different types of robots that could replace people in performing complex procedures), processing and analysis of big data using artificial intelligence to optimize processes, particularly in the field of exploration and production, processing and transportation. Digitalization of the oil and gas sector is a powerful factor in the improvement of the efficiency of the Russian economy. However, Russian companies are notably lagging behind in this field of innovative development and there are problems and high risks that need to be overcome to realize its potential for business and society.Conclusions. Given the strategic importance of the oil and gas industry for Russia, its sustainable development and national security, it is recommendable to focus on the development and implementation of digital technologies. This is crucial for the digitalization of long-term projection and strategic planning, assessment of the role and place of Russia and its largest energy companies in the global market with allowance for a maximum number of different internal and external factors.

Asian Americans and Pacific Islanders: Employment Issues in the United States

2011 ◽  
Vol 9 (1-2) ◽  
pp. 58-69
Author(s):  
Marlene Kim
Keyword(s):  
United States ◽  
Asian Americans ◽  
The United States ◽  
Current Data ◽  
Pacific Islanders ◽  
Native Hawaiians ◽  
Data Sets ◽  
High Poverty ◽  
Unemployment Rates

Asian Americans and Pacific Islanders (AAPIs) in the United States face problems of discrimination, the glass ceiling, and very high long-term unemployment rates. As a diverse population, although some Asian Americans are more successful than average, others, like those from Southeast Asia and Native Hawaiians and Pacific Islanders (NHPIs), work in low-paying jobs and suffer from high poverty rates, high unemployment rates, and low earnings. Collecting more detailed and additional data from employers, oversampling AAPIs in current data sets, making administrative data available to researchers, providing more resources for research on AAPIs, and enforcing nondiscrimination laws and affirmative action mandates would assist this population.

Population fragmentation causes inadequate gene flow and increases extinction risk

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Gene Flow ◽  
Extinction Risk ◽  
Random Mating ◽  
Large Population ◽  
Isolated Population ◽  
Population Fragmentation ◽  
Single Population ◽  
Total Size ◽  
Limited Gene Flow

Most species now have fragmented distributions, often with adverse genetic consequences. The genetic impacts of population fragmentation depend critically upon gene flow among fragments and their effective sizes. Fragmentation with cessation of gene flow is highly harmful in the long term, leading to greater inbreeding, increased loss of genetic diversity, decreased likelihood of evolutionary adaptation and elevated extinction risk, when compared to a single population of the same total size. The consequences of fragmentation with limited gene flow typically lie between those for a large population with random mating and isolated population fragments with no gene flow.

Epidemiological Evidence that Maternal Influenza Contributes to the Aetiology of Schizophrenia

1993 ◽  
Vol 163 (4) ◽  
pp. 522-534 ◽  
Author(s):  
W. Adams ◽  
R. E. Kendell ◽  
E. H. Hare ◽  
P. Munk-Jørgensen
Keyword(s):  
Data Sets ◽  
Time Lags ◽  
Epidemiological Evidence ◽  
Intrauterine Development ◽  
Increased Risk ◽  
Schizophrenic Patients ◽  
The Relationship ◽  
Monthly Incidence ◽  
Maternal Influenza

The epidemiological evidence that the offspring of women exposed to influenza in pregnancy are at increased risk of schizophrenia is conflicting. In an attempt to clarify the issue we explored the relationship between the monthly incidence of influenza (and measles) in the general population and the distribution of birth dates of three large series of schizophrenic patients - 16 960 Scottish patients born in 1932–60; 22 021 English patients born in 1921–60; and 18 723 Danish patients born in 1911–65. Exposure to the 1957 epidemic of A2 influenza in midpregnancy was associated with an increased incidence of schizophrenia, at least in females, in all three data sets. We also confirmed the previous report of a statistically significant long-term relationship between patients' birth dates and outbreaks of influenza in the English series, with time lags of - 2 and - 3 months (the sixth and seventh months of pregnancy). Despite several other negative studies by ourselves and others we conclude that these relationships are probably both genuine and causal; and that maternal influenza during the middle third of intrauterine development, or something closely associated with it, is implicated in the aetiology of some cases of schizophrenia.

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