First Stage Of Colonization Research Articles

Trade on the Frontier: Entrepreneurial Techniques and Practices in the Russian Far East in the Second Half of the 19th – Early 20th Centuries

The article is devoted to the specifics of the forms and methods of trade on the Far Eastern frontier in the second half of the 19th – early 20th centuries. At the initial stage of colonization of the region, trade was distinguished by a number of features characteristic of frontier zones: the predominance of import trade, distribution trade carried out along the rivers from barges, fairs and mixed stationary trade. One of the main features of trade on the Far Eastern frontier was significant foreign influence. The competitive advantages of entrepreneurs from the USA and European countries were formed at the first stage of colonization from the delivery of goods by sea, the presence of established connections with suppliers of goods in the homeland, the possibility of obtaining a loan or the availability of working capital, the attraction of qualified compatriot employees, high quality of service and a comfortable environment in stores, and at the beginning of the 20th century – due to the export of technical innovations, further improvement of the quality of service, and the introduction of new standards of retail premises. We can speak of the perception of some of these practices by Russian merchants and positive changes in the organization of their trade business only in relation to the end of the 19th – beginning of the 20th century. It is difficult to judge, given the lack of memoirs of regional entrepreneurs, whether this occurred under the influence of European entrepreneurs or it was a consequence of business development and the increased level of education of local merchants. The main reasons for the success of the Chinese traders were solidarity, the ability to please the customer, mutual lending, minimizing expenses on advertising, insurance, furnishings of retail premises, heating, lighting and wages of employees, as well as the use of illegal and legal, but morally dubious methods of enrichment - the sale of low-quality or spoiled goods, non-payment of taxes, smuggling, fraud. Russian and European entrepreneurs estimated the methods and practices of Chinese entrepreneurs negatively, and perceived them as dangerous competitors. The Asian influence on Russian entrepreneurial culture was complicated not only by the existence of a religious and cultural boundary between the Chinese and Russians, but also by the European idea of civilizational superiority and the civilizing mission of Europe, which was accepted by the educated society of the Russian Empire and formed the basis for the attitude not only towards aborigine, but also towards Chinese migrants.

Epiplastic Algal Communities on Different Types of Polymers in Freshwater Bodies: A Short-Term Experiment in Karst Lakes

The increasing amount of plastic debris in water ecosystems provides a new substrate (epiplastic microhabitats) for aquatic organisms. The majority of research about epiplastic communities has focused on seawater environments, while research is still quite limited and scattered concerning freshwater systems. In this study, we analyze the first stages of colonization on different types of plastic by a periphytic algae community (its composition and dominant species complex) in freshwater bodies located in a nature reserve (within the Middle Volga Basin). A four-week-long incubation experiment on common plastic polymers (PET, LDPE, PP, and PS), both floating and dipped (~1 m), was conducted in two hydrologically connected karst water bodies in July 2023. The composition of periphytic algae was more diverse (due to the presence of planktonic, benthic, and periphytic species) than the phytoplankton composition found in the water column, being weakly similar to it (less than 30%). Significant taxonomic diversity and the dominant role of periphytic algae were noted for diatoms (up to 60% of the total composition), cyanobacteria (up to 35%), and green (including Charophyta) algae (up to 25%). The composition and structure of periphytic algae communities were distinct between habitats (biotope specificity) but not between the types of plastic, determined primarily by a local combination of factors. Statistically significant higher values of abundance and biomass were demonstrated for some species, particularly for Oedogonium on PP and Nitzschia on LDPE (p-value ≤ 0.05). As colonization progressed, the number of species, abundance, and dominance of individual taxa increased. In hydrologically connected habitats, different starts of colonization are possible, as well as different types of primary succession (initiated by potentially toxic planktonic cyanobacteria or benthic cyanobacteria and mobile raphid diatoms). Within the transparency zone, colonization was more active on the surface (for example, in relation to green algae on PP (p-value ≤ 0.05)). These results indicate a tendency for microalgae communities to colonize actively submerged plastic materials in freshwater, and they may be useful in assessing the ecological status of these aquatic ecosystems.

Changes in carbon metabolism and dissolved organic carbon fluxes on seagrass patches (Halodule wrightii) with different ages in Southern Gulf of California

Seagrass meadows are highly dynamic, particularly in sites where extreme climatological events may produce a mosaic of patches with different ages. This study evaluates the community carbon metabolism, dissolved organic carbon (DOC) fluxes and associated fauna in patches of Halodule wrightii with different ages since establishment. Net community production declined as patch age increased, probably due to the increase in non-photosynthetic tissues, higher respiration rates of the community assemblage and a likely increase in self-shading of the canopy. The export of DOC was significantly higher in the youngest patches, mainly as a consequence of the lower seagrass net production recorded in older meadows. We concluded that ‘colonizers’ seagrass species may show higher production rates and DOC release during the first stages of colonization, which suggest that, the production, organic carbon exportation and their role as relevant blue carbon communities may be higher than expected.

ВОЕННО-КРЕПОСТНЫЕ ЛИНИИ РОССИЙСКОЙ ИМПЕРИИ ЮЖНОГО УРАЛА НА РУБЕЖЕ XVIII-XIX ВЕКОВ

This article is devoted to one of the topical issues of Kazakhstan’s colonization by the Russian Empire. At the first stage of colonization, the northern region of Kazakhstan became Russia's interest. Military factor was the leading one in the implementation of colonial policy. At the turn of the 18th-19th centuries, military fortification lines were erected along the northwestern borders, additional regular troops and Cossacks were sentthere, and a part of the civilian population was relegated to the military-cossack ranks. It was a starting point for the further advancement of the empire in the east. As a result of military reforms and reorganization of troops, thegarrisons were significantly strengthened, and the defense capacity of fortresseswas increased. Orenburg authorities pursued a policy of disunion, separation of indigenous peoples of the Southern Urals: Kazakhs, Bashkirs, and Nogais. The disunion policy and social assimilation of the ruling clan by various means were carried out. The issue of transferring military lines deep into the steppes by the beginning of the 19th century was practically resolved.

The role of polychaetes in bioerosion of submerged mosaic floors in the Underwater Archaeological Park of Baiae (Naples, Italy)

The study investigated the role of boring polychaetes in the bioerosion of a submerged Roman mosaic floor in the Underwater Archaeological Park of Baiae (Naples, Italy). Three boring species, Dodecaceria concharum, Polydora ciliata, and Pseudopolydora antennata, were found. The initial colonization phases of boring polychaetes were investigated on experimental limestone panels placed underwater in the same marine area. The results showed that the ecological succession was characterized by a first stage of colonization with abundant spionids and a second stage with a boring mature community dominated by D. concharum. The study of silicone casts of the bored traces allowed confirmation that the ichnospecies belonging to the ichnogeneraMaeandropolydora could be attributed to the action of spionid worms, whereas D. concharum is able to produce tongue- and ribbon-shaped borings (ichnogenus Caulostrepsis), and variously contorted galleries (ichnogenus Maeandropolydora) by settling inside borings produced by other polychaetes and increasing the complexity of the gallery system by modifying them. The study of the epilithic polychaete community highlighted that the site is characterized by a low hydrodynamism. Therefore, the most suitable in situ preservation interventions would be the covering of the mosaics with sand layers or geotextiles.

The dynamics of barter between the Russians and Alaska Natives, 1741–1867

This article explores the dynamics of barter/trade between Russians and Alaska natives under the Russian Empire. During the first stage of colonization, the Russians (unlike the English and French) did not tend to barter/trade. They preferred to take the main riches of Alaska, especially valuable furs, on their own, or to obtain them by exploiting local people in hunting parties, deploying non-economic coercion to work and debt bondage. Moreover, the trade between the Russians and natives was complicated by the high cost of delivery, the chronic deficit of commodities, a relatively narrow assortment and the prohibition of selling firearms and alcohol (with a few exceptions). The paper demonstrates the formation of three different systems of barter/trade with their own dynamics during Russian colonization of Alaska. Though relatively profitable overall, the Russian fur trade in Alaska was less effective than similar operations run by their competitors, French, American and British traders. The development of the fur trade had a dramatic negative effect on the fate of many native peoples. Nevertheless, it improved indigenous standards of living through its influence on material culture and contributed to a decrease in the number of intertribal conflicts.

Seedling establishment and regeneration in a harvested Eucalyptus plantation at Maragamuwa, Naula, Sri Lanka

The first year of secondary succession in a harvested Eucalyptus camaldulensis plantation near Maragamuwa village, Naula, was examined to see the possible effect of distance from the adjacent relatively undisturbed mature forest on the form and composition of natural regeneration after removal of eucalypts. Composition, relative densities and absolute abundance were examined in cleared 40, 20 × 20 m 2 quadrats placed in eight 1 ha blocks in two types of locations: harvested eucalypt plantation away from the natural forest (MP) and harvested blocks next to the natural forest (MT), and compared with 20 similar sized quadrats sampled in the adjacent mature forest (NF). Relative density values for MT and MP were compared with the adjacent NF using Kruskal-Wallis and Mann-Whitney U tests. A total of 11,207 individuals from 77 species were recorded per hectare in MP, while 11,658 individuals/ha from 61 species were recorded from MT and 5,925 individuals/ha from 39 species in NF. Relative densities of seedlings in MP and MT were significantly different from NF ( p p>0.05 ). Most individuals in MP and MT were 1-100 cm tall. Species composition suggests the basis for seral succession, with the cleared and distant MP plots having most non-forest species, and a high abundance per species compared with the MT plots adjacent to the mature forest. Natural forest plots had fewer individuals in each family or species, and a far lower density of the lianas typical of the first stages of colonization. In the first year of succession, there were indications of a distance effect in blocks adjacent to forest sites.

COSSACKS’ LANDHOLDING (XIX - BEGINNING OF XX CENTURIES)

The main type of land the ownership in the first stage of colonization of the Caucasian Line was free of the plots of the lands Such land was called "native lands" They created the preconditions for the formation of the Cossacks’ community In the early nineteenth century the land unsurveying was started In the postreform period, the transformation of estate in land was begun. The government, the main owner of the land, handed over the using of different parts of it to it’s army for free. The army passed the land down to Stanitca societies. Those, in turn, distributed the plots between the Cossacks, depending on the employment position. Granting the Cossacks land was seen as compensation for the service. The Cossack officers and civil servants received the retirement money lands after the separation from service in favour of hereditary possession. According to the decision of the village stakeholders, the Cossacks could lease public lands.

Global transcriptional analysis suggests Lasiodiplodia theobromae pathogenicity factors involved in modulation of grapevine defensive response.

BackgroundLasiodiplodia theobromae is a fungus of the Botryosphaeriaceae that causes grapevine vascular disease, especially in regions with hot climates. Fungi in this group often remain latent within their host and become virulent under abiotic stress. Transcriptional regulation analysis of L. theobromae exposed to heat stress (HS) was first carried out in vitro in the presence of grapevine wood (GW) to identify potential pathogenicity genes that were later evaluated for in planta expression.ResultsA total of 19,860 de novo assembled transcripts were obtained, forty-nine per cent of which showed homology to the Botryosphaeriaceae fungi, Neofusicoccum parvum or Macrophomina phaseolina. Three hundred ninety-nine have homology with genes involved in pathogenic processes and several belonged to expanded gene families in others fungal grapevine vascular pathogens. Gene expression analysis showed changes in fungal metabolism of phenolic compounds; where genes encoding for enzymes, with the ability to degrade salicylic acid (SA) and plant phenylpropanoid precursors, were up-regulated during in vitro HS response, in the presence of GW. These results suggest that the fungal L-tyrosine catabolism pathway could help the fungus to remove phenylpropanoid precursors thereby evading the host defense response. The in planta up-regulation of salicylate hydroxylase, intradiol ring cleavage dioxygenase and fumarylacetoacetase encoding genes, further supported this hypothesis. Those genes were even more up-regulated in HS-stressed plants, suggesting that fungus takes advantage of the increased phenylpropanoid precursors produced under stress. Pectate lyase was up-regulated while a putative amylase was down-regulated in planta, this could be associated with an intercellular growth strategy during the first stages of colonization.ConclusionsL. theobromae transcriptome was established and validated. Its usefulness was demonstrated through the identification of genes expressed during the infection process. Our results support the hypothesis that heat stress facilitates fungal colonization, because of the fungus ability to use the phenylpropanoid precursors and SA, both compounds known to control host defense.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-2952-3) contains supplementary material, which is available to authorized users.

PecS is an important player in the regulatory network governing the coordinated expression of virulence genes during the interaction between Dickeya dadantii 3937 and plants

Successful infection of a pathogen relies on the coordinated expression of numerous virulence factor-encoding genes. In plant-bacteria interactions, this control is very often achieved through the integration of several regulatory circuits controlling cell-cell communication or sensing environmental conditions. Dickeya dadantii (formerly Erwinia chrysanthemi), the causal agent of soft rot on many crops and ornamentals, provokes maceration of infected plants mainly by producing and secreting a battery of plant cell wall-degrading enzymes. However, several other virulence factors have also been characterized. During Arabidopsis infection, most D. dadantii virulence gene transcripts accumulated in a coordinated manner during infection. This activation requires a functional GacA-GacS two-component regulatory system but the Gac system is not involved in the growth phase dependence of virulence gene expression. Here we show that, contrary to Pectobacterium, the AHL-mediated ExpIR quorum-sensing system does not play a major role in the growth phase-dependent control of D. dadantii virulence genes. On the other hand, the global regulator PecS participates in this coordinated expression since, in a pecS mutant, an early activation of virulence genes is observed both in vitro and in planta. This correlated with the known hypervirulence phenotype of the pecS mutant. Analysis of the relationship between the regulatory circuits governed by the PecS and GacA global regulators indicates that these two regulators act independently. PecS prevents a premature expression of virulence genes in the first stages of colonization whereas GacA, presumably in conjunction with other regulators, is required for the activation of virulence genes at the onset of symptom occurrence.

Recovering the Reptile Community after the Mine‐Tailing Accident of Aznalcóllar (Southwestern Spain)

Abstract Ecosystem restoration requires that habitat requirements of all species be considered. Among animal communities in Mediterranean ecosystems, reptiles, as ectothermic vertebrates, need refuges for avoidance of extreme environmental temperatures, concealment from predators, and oviposition sites. In 1998, a massive amount of tailings broke out of the holding pond of the Aznalcóllar mine (southwestern Spain) and polluted the Guadiamar river valley. After the accident, a soil‐ and vegetation restoration program began, and the Guadiamar Green Corridor was created to connect two huge natural areas, Doñana National Park and the Sierra Morena. Within this corridor, the reptile community remained dramatically impoverished, probably because of elimination of all natural refuges during the soil restoration program. To test this hypothesis, we set an array of artificial refuges (logs) in a large experimental plot. During the 5 years of the experiment (2002–2006), the area managed with artificial refuges exhibited a better and faster recovery of the reptile community in species richness and individual abundance than did the control area with no artificial refuges. Moreover, reptile colonization of the Guadiamar Green Corridor was transverse rather than lineal—that is, it did not act as a corridor for reptiles, at least in the first stages of colonization. This suggests that landscape restoration programs should not neglect refuge availability, a limiting resource for reptile species.

Effect of heat treatment on extracellular enzymatic activities involved in beech wood degradation by Trametes versicolor

Effect of heat treatment on extracellular enzymes involved in wood degradation by Trametes versicolor was investigated. Heat-treated and untreated beech blocks were exposed to T. versicolor on malt-agar medium and extracellular enzymatic activities investigated. A strong ABTS oxidizing activity has been detected during the first stage of colonization in both cases, while cellulase activities are mainly detected in the case of untreated beech wood. Further investigations carried out on holocellulose, isolated using sodium chlorite delignification procedure and subjected to heat treatment or not, indicate that commercially available cellulases and xylanases are able to hydrolyse untreated holocellulose, while heat-treated holocellulose was not affected. All these data suggest that chemical modifications of wood components during heat treatment disturb enzymatic system involved in wood degradation.

Changes in seed rain during secondary succession in a tropical montane cloud forest region in Oaxaca, Mexico

AbstractSeed dispersal is the first stage of colonization, and potentially affects recruitment. This process deserves more attention in tropical montane cloud forests (TMCF), since secondary succession is common owing to episodic disturbances. We studied annual seed rain in 10 nearby forest stands, ≈7 to ≈100 y following shifting agriculture, and one primary forest stand in southern Mexico to test the hypothesis that seed rain is limited at the scale of neighbouring fragments and that such limitation differs among species with different dispersal modes and successional origin. Annual seed rain was heterogeneous among forest fragments probably due to the prevalence of local seed dispersal, differences in stand age and the proportion of zoochory, and may help explain the patchy distribution of species observed in TMCF. Seed rain abundance and species diversity per unit trap area increased with the age of the stand. Biotically dispersed seeds increased towards older stands relative to abiotically dispersed seeds. Late-successional seeds were rarer in early successional stands than pioneer seeds in late-successional stands, suggesting that long-distance dispersal is generally more common for pioneer plants. Seed dispersal appears to constrain forest regeneration and to influence fragment species composition as a function of the distance from the source forests.

In vitro and in vivo characterization of a Bordetella bronchiseptica mutant strain with a deep rough lipopolysaccharide structure.

Bordetella bronchiseptica is closely related to Bordetella pertussis, which produces respiratory disease primarily in mammals other than humans. However, its importance as a human pathogen is being increasingly recognized. Although a large amount of research on Bordetella has been generated regarding protein virulence factors, the participation of the surface lipopolysaccharide (LPS) during B. bronchiseptica infection is less understood. To get a better insight into this matter, we constructed and characterized the behavior of an LPS mutant with the deepest possible rough phenotype. We generated the defective mutant B. bronchiseptica LP39 on the waaC gene, which codes for a heptosyl transferase involved in the biosynthesis of the core region of the LPS molecule. Although in B. bronchiseptica LP39 the production of the principal virulence determinants adenylate cyclase-hemolysin, filamentous hemagglutinin, and pertactin persisted, the quantity of the two latter factors was diminished, with the levels of pertactin being the most greatly affected. Furthermore, the LPS of B. bronchiseptica LP39 did not react with sera obtained from mice that had been infected with the parental strain, indicating that this defective LPS is immunologically different from the wild-type LPS. In vivo experiments demonstrated that the ability to colonize the respiratory tract is reduced in the mutant, being effectively cleared from lungs within 5 days, whereas the parental strain survived at least for 30 days. In vitro experiments have demonstrated that, although B. bronchiseptica LP39 was impaired for adhesion to human epithelial cells, it is still able to survive within the host cells as efficiently as the parental strain. These results seem to indicate that the deep rough form of B. bronchiseptica LPS cannot represent a dominant phenotype at the first stage of colonization. Since isolates with deep rough LPS phenotype have already been obtained from human B. bronchiseptica chronic infections, the possibility that this phenotype arises as a consequence of selection pressure within the host at a late stage of the infection process is discussed.

Seed availability and recruitment of the perennial herb Sanicula europaea1

Dispersal ability is an important determinant of plant distribution and a key factor in predicting effects of habitat fragmentation. In recent years, dispersal limitation has been demonstrated empirically by seed-sowing experiments for a number of plant species. However, these studies have been criticized for dealing with only the first stages of colonization and for not being replicated over several years. In this study we present data from transplantation experiments with seeds and established plants of the perennial herb Sanicula europaea L. Experiments were carried out in several years and at sites with and without natural occurrence of the species. We also examined the effect of vegetation removal on seedling recruitment. Sanicula europaea germinated at several previously unoccupied sites, but our results provide no evidence that the distribution of S. europaea is dispersal limited. Moreover, unlike studies on several other species, there was no evidence that existing vegetation limits recruitment.

Epifluorescence and Scanning Electron Microscopy of Host-Pathogen Interactions between Pythium porphyrae (Peronosporales, Oomycota) and Porphyra yezoensis (Bangiales, Rhodophyta)

The initial steps of host-pathogen interactions leading to successful colonization of Porphyra yezoensis thalli by zoospores of Pythium porphyrae were studied using epifluorescence and scanning electron microscopy. Biflagellated zoospores act as the infective agents for the red rot causing microbial pathogen Pythium porphyrae. These biflagellate zoospores were similar in morphology to primary and secondary zoospores of diplanetic Oomycetes. The flagella lie in a longitudinal groove on the ventral zoospore surface, with long, fine mastigonemes occurring on the anterior tinsel flagellum. There was no evidence of zoospore chemotaxis. The zoospores came into contact, attached and encysted onto the host thallus. The membrane-bound zoospores did not stain with calcofluor, which is specific for chitin and glucans, while the cell walled cysts and mycelia specifically stained with calcofluor when viewed by epifluorescence microscopy, allowing in situ identification of the encysted zoospores, the first stage of colonization on the host thallus. Cysts attached to the host thallus developed a cell wall, germinated, formed appressoria (an essential prelude of penetration), and penetrated the host surface near the site of cyst attachment. The cysts appeared to be adhering to the host thallus by forming a cementing matrix around encysted zoospores when observed with a scanning electron microscope. Absence of inward deformations at penetration sites suggested that enzymatic action rather than mechanical pressure was responsible for initial penetration of the host cell wall. The specific staining of spore walls with calcofluor fluorescent brightner is an inexpensive, easy and rapid technique for early identification of parasitized Porphyra thalli.

Seasonal variation of biomass and productivity of the periphytic community on artificial substrata in the Jurumirim Reservoir (Sao Paulo, Brazil)

The seasonal variation of the periphytic community attached to an artificial substratum (glass tubes) was studied during two different periods in a lagoon connected to the Paranapanema River, the main tributary of the Jurumirim Reservoir (Sao Paulo–Brazil). An analysis of dry weight, ash free dry weight, chlorophyll a, phaeophytin and primary productivity of periphyton was carried out. The first experiment lasted from August to December 1993, the second from February to June 1994. Tubes were removed after 7, 14, 21, 28, 60, 90 and 119 days of incubation. In the 1st experiment, the periphytic community reached a higher biomass after the 4th week of colonization (28th day), in the 2nd experiment after the 2nd week (14th day). This discrepancy is related to seasonal differences in environmental factors (water temperature, nutrients concentrations and water discharge) that determine initial colonization. After the first stages of colonization, the biomass and primary productivity of periphyton reached their maximum values after the 60th day of incubation. In both experiments, three developmental phases could be discerned. In the initial phase, an exponential growth was observed. In the second phase, the bioderm reached its maximum biomass and productivity. In the third phase, a decrease of biomass and productivity occurred.

Fungal colonization of attached beech branches

summaryEarly colonizing fungal communities in beech branches exhibit a distinct spatial organization. Decay often begins in distal regions with stain‐associated fungi, which derive from latent propagules in the wood and bark, effecting the first stages of colonization. This characteristic assemblage is followed by a more combative group of wood‐rotting fungi, particularly Basidiomycotina. The resource at the front of colonization is partitioned between individuals of different species intermixed without clear delimitation. By contrast, the more combative Basidiomycotina which arrive later and displace the fungi in the colonization front usually occupy much larger spatial domains clearly delimited by interaction zone‐lines.

Microscopie de la mycoflore des aiguilles de sapin (Abies alba). III. Marasmius androsaceus

Marasmius androsaceus (L.: Fr.) Fr. spreads in the litter by means of its rhizomorphs. It colonizes needles in autumn, soon after litter fall. Penetration of mycelium into needles occurs through stomata. Rhizomorphs and fruit bodies appear 1 year later, in summer and autumn, emerging from the needles by rupturing the epi- and hypo-dermis. In the first stage of colonization hyphae invade needle tissues in extracellular spaces and along vessels. During a second stage, parenchyma (cellulosic cell walls and residual cytoplasm) is bleached and destroyed. Lignified cell walls are degraded, in particular those of the epi- and hypo-dermis. Marasmius androsaceus activity is restricted to L and F1 litter, reaching a maximum after those of Thysanophora penicillioides (Roum.) Kendrick and Lophodermium piceae (Fuckl.) Höhn. Obvious differences are observed among needles colonized by these three different fungi.

Abundance, Productivity and Energy Flow of a Population of Coleps hirtusNitzsch (Protozoa, Ciliophora) during the First Stage of Colonization in an Experimental Ricefield

Summary Estimates of abundance, production and respiration energy losses by the ciliate population Coleps hirtus Nitzsch , were made in an experimental ricefield located in the province of Reggio Emilia (Northern Italy) during the first stage of colonization (May 10 to 20, 1983) corresponding to the period between the first flooding and the first drying up of the ricefield. Among ciliate populations, Coleps hirtus was the first colonizer of the ricefield, and by the third day reached a peak density of more than 60 × 10 3 1 −1 , remaining the dominant ciliate species for a week. However, on the 8th d a drastic reduction in density due to predation and natural mortality was observed. Production and respiration rates were estimated to be 9.6 kJ · m −2 and 6.1 kJ · m −2 respectively during the time period considered. The net production efficiency was 61 %.