Evolutionary Changes In Structure Research Articles

GVC spillovers on total factor productivity of local firms: evidence from the Russian Federation

Global value chains (GVCs) generate significant effects on participating firms. But can GVCs affect other companies in the host economies? We propose a conceptual framework for GVC spillovers and test it using data for Russian manufacturing firms in 2009–2015. Using a panel estimation technique with random and fixed effects, we find that firms in industries that are intensively integrated into GVCs, on average, have higher total factor productivity (TFP), controlling for firm heterogeneity, industry and region fixed effects. TFP gains in GVCs are unequally distributed and depend on (i) the industry’s position in the GVC, (ii) the industry’s technological intensity and (iii) the firm’s TFP level. We relate the findings to the evidence of the “optimal” technological gap that maximizes productivity spillovers for national companies. The results are highly relevant for policymakers as they prove that trade policy and foreign direct investment attraction policy should not go hand in hand but should be incorporated into GVC-oriented policy to encourage the full range of TFP improvements in local (non-GVC-included) firms. To fully benefit from GVC-oriented policy, State policy should encourage the development of inter-firm links. In addition, our results support the importance of evolutionary structural changes in economic upgrading in GVCs and the strength of the role of policies oriented towards medium-technology industries as drivers of technological development.

Draft Sequencing Crested Wheatgrass Chromosomes Identified Evolutionary Structural Changes and Genes and Facilitated the Development of SSR Markers.

Crested wheatgrass (Agropyron cristatum), a wild relative of wheat, is an attractive source of genes and alleles for their improvement. Its wider use is hampered by limited knowledge of its complex genome. In this work, individual chromosomes were purified by flow sorting, and DNA shotgun sequencing was performed. The annotation of chromosome-specific sequences characterized the DNA-repeat content and led to the identification of genic sequences. Among them, genic sequences homologous to genes conferring plant disease resistance and involved in plant tolerance to biotic and abiotic stress were identified. Genes belonging to the important groups for breeders involved in different functional categories were found. The analysis of the DNA-repeat content identified a new LTR element, Agrocen, which is enriched in centromeric regions. The colocalization of the element with the centromeric histone H3 variant CENH3 suggested its functional role in the grass centromere. Finally, 159 polymorphic simple-sequence-repeat (SSR) markers were identified, with 72 of them being chromosome- or chromosome-arm-specific, 16 mapping to more than one chromosome, and 71 mapping to all the Agropyron chromosomes. The markers were used to characterize orthologous relationships between A. cristatum and common wheat that will facilitate the introgression breeding of wheat using A. cristatum.

Haloadaptation: insights from comparative modeling studies between halotolerant and non-halotolerant dehalogenases

Halophiles are extremophilic microorganisms that grow optimally at high salt concentrations by producing a myriad of equally halotolerant enzymes. Structural haloadaptation of these enzymes adept to thriving under high-salt environments, though are not fully understood. Herein, the study attempts an in silico investigation to identify and comprehend the evolutionary structural adaptation of a halotolerant dehalogenase, DehHX (GenBank accession number: KR297065) of the halotolerant Pseudomonas halophila, over its non-halotolerant counterpart, DehMX1 (GenBank accession number KY129692) produced by Pseudomonas aeruginosa. GC content of the halotolerant DehHX DNA sequence was distinctively higher (58.9%) than the non-halotolerant dehalogenases (55% average GC). Its acidic residues, Asp and Glu were 8.27% and 12.06%, respectively, compared to an average 5.5% Asp and 7% Glu, in the latter; but lower contents of basic and hydrophobic residues in the DehHX. The secondary structure of DehHX interestingly revealed a lower incidence of α-helix forming regions (29%) and a higher percentage of coils (57%), compared to 49% and 29% in the non-halotolerant homologues, respectively. Simulation models showed the DehHX is stable under a highly saline environment (25% w/v) by adopting a highly negative-charged surface with a concomitant weakly interacting hydrophobic core. The study thus, established that a halotolerant dehalogenase undergoes notable evolutionary structural changes related to GC content over its non-halotolerant counterpart, in order to adapt and thrive under highly saline environments.Communicated by Ramaswamy H. Sarma

A New Morphological Dataset Reveals a Novel Relationship for the Adzebills of New Zealand (Aptornis) and Provides a Foundation for Total Evidence Neoavian Phylogenetics

Relationships among Neoaves, a group comprising approximately 95% of all extant birds, are difficult to resolve because of multiple short internodes presumably created by a rapid evolutionary radiation around the K/Pg boundary. This difficulty has plagued both morphological and molecular studies. Compared with molecular studies with extensive taxon and character sampling, morphological datasets have largely failed to provide insight into the phenotypic evolutionary transitions of the neoavian radiation. Extinct neoavian taxa remain an understudied but critical key to resolving relationships among these problematic stem lineages and understanding evolutionary changes in structure and function. Adzebills (Aptornis), some of the most phylogenetically controversial fossil neoavians, are extinct terrestrial birds endemic to New Zealand since at least the early Miocene. Past morphological studies have placed adzebills as a sister taxon to the flightless Kagu of New Caledonia (Rhynochetos jubatus) or to the land- and waterfowl group Galloanseres. Recent molecular studies reveal the Kagu and Sunbittern (Eurypyga helias) to be sister taxa, whereas adzebills have been postulated to be within Rallidae (rails, gallinules, and coots) or the sister taxon of Sarothruridae (flufftails) or Ralloidea (finfoots, flufftails, and rails). To better resolve the position of adzebills and begin constructing a fine-scale total evidence phylogenetic dataset for the base of Neoaves, we constructed a new and more comprehensive morphological dataset of 368 discrete osteological characters for 38 extant and two extinct taxa that includes extensive sampling of nearly all neoavian stem lineages. We then combined this dataset with 32 DNA sequences of the slowly evolving nuclear RAG1 and RAG2 genes. Morphological results place adzebills as the sister taxon of trumpeters (Psophia) within core Gruiformes and confirm strong support for a Kagu+Sunbittern sister group (99% bootstrap value). Results for analyses of the combined data were identical, and the adzebill+trumpeter clade was supported by a 99% Bayesian clade credibility value. Although the Kagu+Sunbittern sister group is consistent with recent molecular hypotheses, the adzebill+trumpeter group is novel.

The Evolution of Cell Communication: The Road not Taken.

In the post-genomic era the complex problem of evolutionary biology can be tackled from the top-down, the bottom-up, or from the middle-out. Given the emergent and contingent nature of this process, we have chosen to take the latter approach, both as a mechanistic link to developmental biology and as a rational means of identifying signaling mechanisms based on their functional genomic significance. Using this approach, we have been able to configure a working model for lung evolution by reverse-engineering lung surfactant from the mammalian lung to the swim bladder of fish. Based on this archetypal cell-molecular model, we have reduced evolutionary biology to cell communication, starting with unicellular organisms communicating with the environment, followed by cell-cell communication to generate metazoa, culminating in the communication of genetic information between generations, i.e. reproduction. This model predicts the evolution of physiologic systems-including development, homeostasis, disease, regeneration/repair, and aging- as a logical consequence of biology reducing entropy. This approach provides a novel and robust way of formulating refutable, testable hypotheses to determine the ultimate origins and first principles of physiology, providing candidate genes for phenotypes hypothesized to have mediated evolutionary changes in structure and/or function. Ultimately, it will form the basis for predictive medicine and molecular bioethics, rather than merely showing associations between genes and pathology, which is an unequivocal Just So Story. In this new age of genomics, our reach must exceed our grasp.

Assessment of the probabilities for evolutionary structural changes in protein folds

The evolution of protein sequences can be described by a stepwise process, where each step involves changes of a few amino acids. In a similar manner, the evolution of protein folds can be at least partially described by an analogous process, where each step involves comparatively simple changes affecting few secondary structure elements. A number of such evolution steps, justified by biologically confirmed examples, have previously been proposed by other researchers. However, unlike the situation with sequences, as far as we know there have been no attempts to estimate the comparative probabilities for different kinds of such structural changes. We have tried to assess the comparative probabilities for a number of known structural changes, and to relate the probabilities of such changes with the distance between protein sequences. We have formalized these structural changes using a topological representation of structures (TOPS), and have developed an algorithm for measuring structural distances that involve few evolutionary steps. The probabilities of structural changes then were estimated on the basis of all-against-all comparisons of the sequence and structure of protein domains from the CATH-95 representative set. The results obtained are reasonably consistent for a number of different data subsets and permit the identification of several 'most popular' types of evolutionary changes in protein structure. The results also suggest that alterations in protein structure are more likely to occur when the sequence similarity is >10% (the average similarity being approximately 6% for the data sets employed in this study), and that the distribution of probabilities of structural changes is fairly uniform within the interval of 15-50% sequence similarity. The algorithms have been implemented on the Windows operating system in C++ and using the Borland Visual Component Library. The source code is available on request from the first author. The data sets used for this study (representative sets of protein domains, matrices of sequence similarities and structural distances) are available on http://bioinf.mii.lu.lv/epsrc_project/struct_ev.html.

Konfliktfelder und Konfliktparteien im Prozeß der lutherischen und reformierten Konfessionalisierung - das Fürstentum Anhalt und die Hochstifte Halberstadt und Magdeburg im 16. Jahrhundert

Article Konfliktfelder und Konfliktparteien im Prozeß der lutherischen und reformierten Konfessionalisierung - das Fürstentum Anhalt und die Hochstifte Halberstadt und Magdeburg im 16. Jahrhundert was published on December 1, 2001 in the journal Archiv für Reformationsgeschichte - Archive for Reformation History (volume 92, issue jg).

Revolution, Evolution and Local Government Structure: An Empirical Analysis of London

Conventional analyses of local government structure focus on the revolutionary changes that result from deliberate reorganisations. We propose a new perspective on structural change that emphasises the importance of evolutionary processes as well as radical reforms. Evolutionary changes in structure are caused, for example, by population growth or decline and reallocations of service responsibilities between tiers. The argument is illustrated by an empirical analysis of fragmentation and concentration in the structure of local government in London. The evidence reveals that structural change is the norm rather than the exception: it occurs even when the absolute number of local government tiers and units is constant.

Evolutionary synthesis of separation processes

AbstractThis paper deals with the problem of finding, among many alternatives, the sequence of separation units that will isolate desired products from given feed at the minimum cost. Multicomponent products can be specified. An evolutionary procedure is presented. This method consists of two phases. In the first phase, a good initial structure is created by heuristic methods. In the second phase, the initial structure is successively modified by making evolutionary structural changes. This logic has been programmed on a digital computer and has been tested on several problems.