scholarly journals Long-term retainment of some chromosomal inversions in a local population of Belgica antarctica Jacobs (Diptera, Chironomidae)

2021 ◽  
Vol 11 (1) ◽  
pp. 16-24
Author(s):  
Paraskeva Michailova ◽  
Julia Ilkova ◽  
Pavlo Kovalenko ◽  
Artem Dzhulai ◽  
Iryna Kozeretska

Genome of antarctic endemic Belgica antarctica Jacobs has been sequenced. However, no set of inversion diagnostic markers has ever been assigned for the species. Using the classical method of polytene chromosome squash preparation, we found three heterozygous inversions located on the second (two heterozygous inversions) and third chromosomes (one heterozygous inversion) in the Belgica antarctica population of a cape of Wiencke Island, 500 m to SW from Port Lockroy. The chromosome set and chromosome variability did not differ from those described in the literature (Atchley and Davis 1979). Every salivary gland chromosome had its own markers by which it can be determined. However, we did not find a sex-linked inversion on chromosome III and heterozygous inversion on chromosome I, reported in earlier studies. For the first time, we observed a strong heterochromatin band in chromosome III at the telomere of one arm. Our data show not only the stability of the described inversions in the population but also the usefulness of the squash preparation technique in the studies of genetic variability of Belgica antarctica in present time.

2021 ◽  
Vol 11 (19) ◽  
pp. 8880
Author(s):  
Bowen Guan ◽  
Cunbo Fan ◽  
Ning An ◽  
Ricardo Cesar Podesta ◽  
Dra Ana Pacheco ◽  
...  

As one of the major error sources, satellite signature effect should be reduced or even erased from the distribution of the post-fit residuals to improve the ranging precision. A simulation of satellite signature effect removal process for normal point algorithm is conducted based on a revised model of satellite response, which fully considers the structural and distribution characteristics of retroreflectors. In order to eliminate both long-term and short-term satellite signature effect, a clipping method for SLR data processing is proposed by defining the clipping location as 5.6 mm away from the mean value of the long-term fit residuals to select effective returns for normal points. The results indicate that, compared to normal points algorithm, the RMS per NP of LAGEOS-1 observation data processed by the clipping method is reduced from 62.90 ± 9.9 mm to 56.07 ± 4.69 mm, and the stability of RMS is improved 53%. This study improves the satellite signature effect model and simulates the fluctuation of normal points caused by satellite signature effect for the first time. The new method based on the simulation of satellite signature effect has stronger robustness and applicability, which can further minimize the influence of satellite signature effect on the SLR production and significantly improve the data property.


2018 ◽  
Vol 7 (4) ◽  
pp. 122-126
Author(s):  
Galina Anatolievna Fadeeva ◽  
Elena Evgenievna Boryakova

The fauna of parasitic mites of bats from the karst caves in the region of the Volga Upland was studied in 2004-2005. Six species of bats such as Daubentons water bat, Brandts bat, whiskered bat, pond bat, northern bat and long-eared bat were examined. 18 species of arthropods were detected, among them there are gamasid mites (10 species) and harvest mites (2 species). Leptotrombidium russicum (Oud., 1902) and Myotrombicula sp. were found for the first time in Central Russia. Spinturnix acuminatus (Koch, 1836), Steatonyssus spinosus (Willmann, 1936), Steatonyssus periblepharus (Kolenati, 1858), Macronyssus flavus (Kolenati, 1856) turned out to be the main group of parasites in this study. As for the insects flies of the family Nycteribiidae and fleas of the family Ischnopsyllidae were found. The cluster analysis of ectoparasite fauna has showed that they are more or less evenly distributed among all members of mixed colonies of bats, while there is no violation of specificity in the choice of hosts. Low values of the Berger-Parker index marked a lack of competition between species, which indicates the stability of parasitic communities formed on bats in mixed colonies and in natural habitats. This fact indicates a complex relationship between the parasites in the community on the one hand, and long-term existence of the community on the other hand. This, in its turn, shows that in long-evolving communities competitive relationships between parasites are obliterated, which gives them stability. Herewith the bat colony is used as an integral whole, although some parasitic species prefer certain types of hosts.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Huarui Yang ◽  
Kangquan Shou ◽  
Shijun Wei ◽  
Zhi Fang ◽  
Qiwen Hu ◽  
...  

Osteochondroma is one of the most common benign bone tumor; however, the surgical treatment still remains a challenge for those that occur at the distal tibiofibular interosseous location. Previously, the transfibular approach has been successfully described, but the potential damage of the syndesmosis would give rise to the instability of the ankle joint and thus may result in the unfavorable long-term outcome. Here, a revised strategy which can protect the syndesmotic complex is introduced. From 2010 to 2017, eleven patients with the distal tibiofibular interosseous osteochondroma who underwent the revised surgery were collected. The distal fibular osteotomy and posterior tibial osteotomy were performed to keep the inferior syndesmosis intact for better stability of the ankle joint. Both the anterior tibiofibular ligaments (AITFL) and posterior tibiofibular ligaments (PITFL) have been preserved successfully, and thus, the stability of the ankle joint has been maintained due to our strategy. The VAS and AOFAS scores were utilized to assess the clinical outcome and function. Postoperatively, all the patients were pain-free and were able to wear the appropriate shoes at the last follow-up. Preoperative and postoperative AOFAS scores were 93.63±6.91 and 47.27±5.27 (P<0.05), respectively. Moreover, the average VAS score was 1.73±0.27 (compared with preoperative as 7.45±2.15, P<0.05), demonstrating obvious improvement after the operation. To our best knowledge, this is the first time to perform the resection of the distal tibial interosseous osteochondroma involving the fibula without interrupting the inferior syndesmotic complex especially the AITFL and PITFL. We believe that this strategy may pave a new way for optimized clinical outcome for these patients with distal tibiofibular interosseous osteochondroma. This clinical trial study is registered with number ChiCTR1900024690.


Author(s):  
V Sidorenko ◽  
A Romanenko ◽  
V Panchenko

The purpose of this article is to develop a new methodology for assessing the stability margin of iron ore opencast sides sections. The sequence of work. To achieve this goal, at the first stage, high-resolution photography was carried out for characteristic sections of the pit wall, followed by computer processing of photographs to assess the fracturing of rocks. The next step was the calculation of the fractal dimension of the array section from the obtained images using the ImageJ and FracLac programs, including the MicroMod2015 plug-in package (add-ons). The next step was assess the disturbance of the massif due to fracturing, a study of the relationship between the fractal dimension and the coefficient of structural weakening was carried out (this coefficient is determined by the classical method through the ratio of the strength of rocks in the massif and in the sample). At the last stage of the work, after establishing the specified connection and calculating the coefficient of structural weakening of rocks that based on the results of determining the fractal dimension, an assessment of the stability margin iron ore opencast sides sections that carried out. The known dependence of the stability safety factor on the coefficient of structural weakening of the array was used. As a result of comparing the fractal dimension of the exposed massif areas based on photographs with the calculation by classical methods, the discrepancy in the structural attenuation coefficient was 5-10%. This indicates a satisfactory convergence and allows the use of this express technique for assessing the fracturing of a section of a pit flank on the basis of fractal dimension. The scientific novelty of the results obtained - for the first time, the analytical dependence of the structural weakening coefficient of rocks on the fractal dimension of the massif cracks was established, which made it possible to simplify the procedure for its calculation. The practical significanceof the work lies in the creation of a new methodology for assessing the stability margin of an iron ore opencast side sections that the basis of rock fractures fractal analysis.


2009 ◽  
Vol 66 (6) ◽  
pp. 1335-1340 ◽  
Author(s):  
Hans Petter Knudsen

Abstract Knudsen, H. P. 2009. Long-term evaluation of scientific-echosounder performance. – ICES Journal of Marine Science, 66: 1335–1340. When scientific acoustic instruments are utilized for quantitative measurements of underwater biological resources, it is extremely important to know their overall performance, and it is imperative to measure their stability over time. Echosounders mounted on research vessels are therefore routinely calibrated several times annually, often immediately before, during, and after important resource-assessment surveys. In recent years, multifrequency systems for acoustic surveys requiring species identification and categorization based on the frequency response of targets have been introduced, further emphasizing the importance of monitoring instrument performance. In the 1970s, hydrophones and steel spheres were used as alternative references for calibrations. Substantial variations of system performance were observed, however, and gradually it was accepted that the use of hydrophones was inappropriate, because their performance varied more than that of the instruments being calibrated. Not until optimized reference targets were introduced in ca. 1980, was it possible to monitor the stability of acoustic-survey equipment with an acceptable degree of confidence. For the first time, the true, long-term stability of transducers, including ageing effects, could be accurately measured. This paper gives examples of calibration time-series for several Norwegian research vessels operating in various regions from Arctic to tropical waters.


2021 ◽  
Author(s):  
SUCHHANDA SWAIN ◽  
Lakshmi Unnikrishnan ◽  
Smita Mohanty ◽  
Sanjay K. Nayak

Abstract MMMs have been opened up a new window in gas separation and purification applications, but the actual viability can be reckoned on the basis of performance achieved in realistic feed conditions. This research highlights the selection of silica decorated graphene for the first time to prepare nanocomposite membranes. In the study, XRD, Raman, and UV validated the existence of the different fillers within the host Polysulfone (PSf), while TEM authenticated their distribution. The burst strength and thermal properties were also investigated. Besides, it covered a prudent step towards resolving the dominant ingredients, which routinely appraise the stability and durability of the membranes. These indexes are long-term gas permeation up to 120 hours coupled with sustainability against hydrothermal and chemical resistance under various conditions similar to real-life separation applications. Finally, the report demonstrated that the nanohybrid integrated membrane systems displayed optimum separation performance and stability than their parent counterparts: PSf/mSiO2, PSf/GO.


2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Luís F. Seoane ◽  
Xaquín Loredo ◽  
Henrique Monteagudo ◽  
Jorge Mira

Abstract We study the stability of Catalan and Spanish coexistence in Catalonia, a key political and economic European region. Recent, abundant empirical data of language use is analyzed within an analytic model of population dynamics. This model contemplates the possibilities of both long-term language coexistence and decline. The data needs to be interpreted under different circumstances. The most likely scenario, we find, is a sustained coexistence. Extreme cases still lead to the decline of one of the tongues–we delimit when this can happen. Asymptotic behavior is often an unreliable predictor in complex social systems; we make an attempt at forecasting fractions of speakers towards $$2030$$ 2030 . These also suggest sustained coexistence, but some counterintuitive dynamics are unveiled. Model parameters estimated from the data convey relevant information about the prestige and interlinguistic similarity of both tongues. We quantify these parameters rigorously for these languages for the first time. Remarkably, Spanish is found to have a larger prestige in areas which historically had larger Catalan monolingual communities. With limited, spatially-segregated data we examine more fine grained dynamics, thus better addressing the likely outcomes. Differences in model parameters across regions reveal how the two languages are perceived in more urban or rural environments.


1979 ◽  
Vol 42 (04) ◽  
pp. 1135-1140 ◽  
Author(s):  
G I C Ingram

SummaryThe International Reference Preparation of human brain thromboplastin coded 67/40 has been thought to show evidence of instability. The evidence is discussed and is not thought to be strong; but it is suggested that it would be wise to replace 67/40 with a new preparation of human brain, both for this reason and because 67/40 is in a form (like Thrombotest) in which few workers seem to use human brain. A �plain� preparation would be more appropriate; and a freeze-dried sample of BCT is recommended as the successor preparation. The opportunity should be taken also to replace the corresponding ox and rabbit preparations. In the collaborative study which would be required it would then be desirable to test in parallel the three old and the three new preparations. The relative sensitivities of the old preparations could be compared with those found in earlier studies to obtain further evidence on the stability of 67/40; if stability were confirmed, the new preparations should be calibrated against it, but if not, the new human material should receive a calibration constant of 1.0 and the new ox and rabbit materials calibrated against that.The types of evidence available for monitoring the long-term stability of a thromboplastin are discussed.


1970 ◽  
Vol 19 (1) ◽  
pp. 89-99
Author(s):  
K. Choudhary ◽  
M. Singh ◽  
M. S. Rathore ◽  
N. S. Shekhawat

This long term study demonstrates for the first time that it is possible to propagate embryogenic Vigna trilobata and to subsequently initiate the differentiation of embryos into complete plantlets. Initiation of callus was possible on 2,4-D. Somatic embryos differentiated on modified MS basal nutrient medium with 1.0 mg/l  of 2,4-D and 0.5 mg/l  of Kn. Sustained cell division resulted in globular and heart shape stages of somatic embryos. Transfer of embryos on to a fresh modified MS basal medium with 0.5 mg/l of Kn and 0.5 mg/l of GA3 helped them to attain maturation and germination. However, the propagation of cells, as well as the differentiation of embryos, were inhibited by a continuous application of these growth regulators. For this reason, a long period on medium lacking these growth regulators was necessary before the differentiation of embryos occurred again. The consequences for improving the propagation of embryogenic cultures in Vigna species are discussed. Key words: Pasture  legume, Vigna trilobata, Globular, Heart shape, somatic embryogenesis D.O.I. 10.3329/ptcb.v19i1.4990 Plant Tissue Cult. & Biotech. 19(1): 89-99, 2009 (June)


2017 ◽  
pp. 34-47
Author(s):  
Hoi Le Quoc ◽  
Nam Pham Xuan ◽  
Tuan Nguyen Anh

The study was targeted at developing a methodology for constructing a macroeconomic performance index at a provincial level for the first time in Vietnam based on 4 groups of measurements: (i) Economic indicators; (ii) oriented economic indicators; (iii) socio-economic indicators; and (iv) economic - social – institutional indicators. Applying the methodology to the 2011 - 2015 empirical data of all provinces in Vietnam, the research shows that the socio-economic development strategy implemented by those provinces did not provide balanced outcomes between growth and social objectives, sustainability and inclusiveness. Many provinces focused on economic growth at the cost of structural change, equality and institutional transformation. In contrast, many provinces were successful in improving equality but not growth. Those facts threaten the long-term development objectives of the provinces.


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