66 research outputs found
Reciprocal genomic evolution in the ant-fungus agricultural symbiosis
The attine ant–fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal cultivars. We show that ant subsistence farming probably originated in the early Tertiary (55–60 MYA), followed by further transitions to the farming of fully domesticated cultivars and leaf-cutting, both arising earlier than previously estimated. Evolutionary modifications in the ants include unprecedented rates of genome-wide structural rearrangement, early loss of arginine biosynthesis and positive selection on chitinase pathways. Modifications of fungal cultivars include loss of a key ligninase domain, changes in chitin synthesis and a reduction in carbohydrate-degrading enzymes as the ants gradually transitioned to functional herbivory. In contrast to human farming, increasing dependence on a single cultivar lineage appears to have been essential to the origin of industrial-scale ant agriculture
The Research of Sequential Images: Rebuilding of Gray (Position) ~ Time Function on Direction Lines and Their Applications
Contrasted with other information carriers, such as speech and text, images contains larger amount of information, especially in sequential images, that is waiting to be exploited, in particular the dynamic information of correlation, difference, and temporal relationship between different frames. This dynamic information contributes a great deal in analysis of 4D images. This paper proposes a method for detecting dynamic information from sequential images, based on the rebuilding of their gray (position)~time function on direction lines, an approach that has been analyzed and studied extensively on the setting of various direction lines. This method is based on motion that is presented on sequential images. In particular, the method, Omni directional M-mode Echocardiography system, which we have studied extensively, will be described leading to a robust way of diagnosing heart diseases
Microwave Synthesis and High‐Mobility Charge Transport of Carbon‐Nanotube‐in‐Perovskite Single Crystals
Organolead trihalide perovskites have emerged as a new class of competitive solution-processed semiconductors due to their unique optoelectronic properties. However, poor ambient stability and charge transport are the Achilles’ heel of hybrid perovskites, thus limiting their applications. In this work, microwave-assisted synthesis is applied for the first time to rapidly grow perovskite single crystals embedded with single-wall carbon nanotubes. These nanotube-in-perovskite single crystals are endowed with a carrier mobility one order of magnitude higher than the pure counterpart and the related photodetectors show an ultrafast photo-response speed (5 and 80 ns for rise and decay time, respectively). The fast and uniform heating of microwave irradiation facilitates the synthesis of ambient-stable crystals with nanoscale additives, paving the way to creating a wide range of mixed-dimensional perovskite-based nanocomposites with optimal properties and device performance
Dwelling as the life basis of Ukrainians
На прикладі містечок Батурина, Глухова, Борзни та Кролевця у статті
розглядається інтер’єр жител населення Чернігово-Сіверщини (друга половина ХVІІІ –
середина ХІХ ст.). На основі значного описового матеріалу, стосовно звичаїв і побуту
українців, який накопичився в середині і особливо в другій половині ХІХ ст. можна
зробити науково-вивірені узагальнення з приводу порівняльної характеристики
українців і росіян. Дослідженням цієї теми займалися М. Маркевич, І. Срезнєвський,
П. Куліш та ін. Значний внесок до вивчення даної проблематики належить історику
М. Костомарову, який виокремив український культурний і традиційно-буттєвий
комплекс із загальноросійського, що утрадиційнилось як спільне за понад сторіччя
співжиття в рамках однієї імперії.
Також у даній статті характеризується поділ оселі на умовні частини та
визначаються основні сакральні центри хати. Автор наголошує на глибокому
символічному обрядово-ритуальному значенні, яке українці надавали всім предметам
хатнього інтер’єру та наголошує на ліричній прив’язаності їх до місця свого проживання.На примере городков Батурина, Глухова, Борзны и Кролевца в статье
рассматривается интерьер жилищ населения Чернигово-Северщины во второй половине
XVIII – середине XIX вв. На основе материалов, описывающих украинские обычаи и быт,
накопившихся в средине, а особенно во второй половине XIX в., можно сделать
обобщения по поводу сравнительной характеристики украинцев и русских.
Исследованием этой темы занимались Н. Маркевич, И. Срезневский, П. Кулиш и
другие ученые. Значительный вклад в изучение данной проблематики принадлежит
историку Н. Костомарову, который выделил украинский культурный и традиционно-
бытейный комплекс из общероссийского, которые сосуществовали более столетия в
границах одной империи.
Также в данной статье характеризируется разделение жилища на условные части
и определяются основные сакральные центры дома (хаты). Автор отмечает глубокое
символическое ритуально-обрядовое значение, которое украинцы придавали всем
предметам домашнего интерьера, а также подчеркивает лирическую привязанность
населения к месту его проживания.Article deals with the interior of dwellings in Chernihiv-Siverskyi region (in the 2nd half
of the ХVІІІ – 1st half of the ХІХ cent.). On the example of towns Baturyn, Glukhiv, Borzna and
Krolevets the article deals with the house interiors of the population of Chernihovo-Sivershchyna
(the second half of the XVIII – mid. XIX cent.). The analysis is based on considerable descriptive
material concerning Ukrainian customs and way of life that has accumulated in the middle and
especially in the second half of the XIX cent. and led to scientific adjusted conclusion about the
comparative characteristics of Ukrainians and Russians. This topic was researched by M.
Markevych, I. Sreznevskyi, P. Kulish and others. A significant contribution to the study of this
subject belongs to historian M. Kostomarov, who singled Ukrainian cultural and traditional
existential complex out of all-Russian complex, that was considered unified for more than three
centuries of coexistence within a single empire. Also, this article characterizes the division of
the house on special parts and identifies the main sacred centres of the house. The attention is
given to the fact that the Ukrainian housing is associated with many beliefs and rituals. It
indicates that the dwelling-house reflects not only people’s ideological and artistic heritage,
but also a pragmatic idea. After all, the house seemed a model of nature and the universe,
which protected both physically and spiritually. We know that house was not only a place where
the family spent most of its life, but it was the family hearth around which ancient and beautiful
traditions were preserved.
The author emphasizes the deep symbolic ritual value that Ukrainians gave to all subjects
of domestic interior and the lyrical attachment to their place of residence. After all, the house
had a kind of sacred meaning for its tenants, that is why, to the house and all domestic things
people gave some philosophical content. Complexity of representations of the world for humans began from the dwelling and was a dominant through all life. It is revealed that a Ukrainian
house with its aesthetic appearance and its interior in particular, is an important factor in
the understanding of the Ukrainian people and makes the character unique, and one that
is very different from the characteristics of other nations. The author concluded that this
topic needs a further study
Molecular traces of alternative social organization in a termite genome
Although eusociality evolved independently within several orders of insects, research into the molecular underpinnings of the transition towards social complexity has been confined primarily to Hymenoptera (for example, ants and bees). Here we sequence the genome and stage-specific transcriptomes of the dampwood termite Zootermopsis nevadensis (Blattodea) and compare them with similar data for eusocial Hymenoptera, to better identify commonalities and differences in achieving this significant transition. We show an expansion of genes related to male fertility, with upregulated gene expression in male reproductive individuals reflecting the profound differences in mating biology relative to the Hymenoptera. For several chemoreceptor families, we show divergent numbers of genes, which may correspond to the more claustral lifestyle of these termites. We also show similarities in the number and expression of genes related to caste determination mechanisms. Finally, patterns of DNAmethylation and alternative splicing support
Molecular Characterization of a Fus3/Kss1 Type MAPK from Puccinia striiformis f. sp. tritici, PsMAPK1
Puccinia striiformis f. sp. tritici (Pst) is an obligate biotrophic fungus that causes the destructive wheat stripe rust disease worldwide. Due to the lack of reliable transformation and gene disruption method, knowledge about the function of Pst genes involved in pathogenesis is limited. Mitogen-activated protein kinase (MAPK) genes have been shown in a number of plant pathogenic fungi to play critical roles in regulating various infection processes. In the present study, we identified and characterized the first MAPK gene PsMAPK1 in Pst. Phylogenetic analysis indicated that PsMAPK1 is a YERK1 MAP kinase belonging to the Fus3/Kss1 class. Single nucleotide polymerphisms (SNPs) and insertion/deletion were detected in the coding region of PsMAPK1 among six Pst isolates. Real-time RT-PCR analyses revealed that PsMAPK1 expression was induced at early infection stages and peaked during haustorium formation. When expressed in Fusarium graminearum, PsMAPK1 partially rescued the map1 mutant in vegetative growth and pathogenicity. It also partially complemented the defects of the Magnaporthe oryzae pmk1 mutant in appressorium formation and plant infection. These results suggest that F. graminearum and M. oryzae can be used as surrogate systems for functional analysis of well-conserved Pst genes and PsMAPK1 may play a role in the regulation of plant penetration and infectious growth in Pst
Testing structural change in partially linear single-index models with error-prone linear covariates
Motivated by an analysis of a real data set from Duchenne Muscular Dystrophy (Andrews and Herzberg, 1985), we propose a new test of structural change for a class of partially linear single-index models with error-prone linear covariates. Based on the local linear estimation for the unknowns in these semiparametric models, we develop a new generalized F-test statistics for the nonparametric part in the partially linear single-index models with error-prone linear covariates. Asymptotic properties of the newly proposed test statistics are proved to follow asymptotically the chi-squared distribution. The new Wilks’ phenomenon is unveiled in a class of semiparametric measure error models. Simulations are conducted to examine the performance of our proposed method. The simulation results are consistent with our theoretical findings. Real data examples are used to illustrate the proposed methodology
Inhibition of Cellular Proteasome Activities Enhances Hepadnavirus Replication in an HBX-Dependent Manner
The X protein (HBX) of the hepatitis B virus (HBV) is not essential for the HBV life cycle in vitro but is important for productive infection in vivo. Our previous study suggests that interaction of HBX with the proteasome complex may underlie the pleiotropic functions of HBX. With the woodchuck model, we demonstrated that the X-deficient mutants of woodchuck hepatitis virus (WHV) are not completely replication defective, possibly behaving like attenuated viruses. In the present study, we analyzed the effects of the proteasome inhibitors on the replication of wild-type and X-negative HBV and WHV. Recombinant adenoviruses or baculoviruses expressing replicating HBV or WHV genomes have been developed as a robust and convenient system to study viral replication in tissue culture. In cells infected with either the recombinant adenovirus-HBV or baculovirus-WHV, the replication level of the X-negative construct was about 10% of that of the wild-type virus. In the presence of proteasome inhibitors, the replication of the wild-type virus was not affected, while the replication of the X-negative virus of either HBV or WHV was enhanced and restored to the wild-type level. Our data suggest that HBX affects hepadnavirus replication through a proteasome-dependent pathway
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