Exotic Groups Research Articles

Placer diamond potential of the siberian craton: possible sources and ages

Many diamond placers in the Siberian craton are heterogeneous consisting of several components that differ in origin and ages of the source. The diamonds are either kimberlite-hosted or are exotic varieties which occur mostly in the northeastern craton periphery and come from primary deposits of unknown types and ages. The two groups of diamond placers in the area represent two evolution trends: those found in Middle Paleozoic kimberlites originated in the Famennian and the exotic diamond groups became involved in sedimentation in the Carnian. The trends have been associated with successive weathering of older diamond hosts and redeposition of the minerals into younger sediments. Having joined since the Late Triassic, the two trends eventually produced a polygenetic and multistage mixture of diamond groups in placers.

Abundance and productivity mediate invader effects on nitrogen dynamics in a California grassland

Soil nitrogen (N) transformations have been shown to be influenced by plant community composition. Identifying species traits that control nitrogen dynamics is more straightforward when species dramatically differ in N input via litter (e.g., N-fixing invaders in a non-fixing community) or in litter carbon:N or lignin:N ratios. Cases where invaders and residents are more similar for such traits are more challenging to evaluate. In these settings, a species' relative abundance and its contribution to overall ecosystem productivity are likely to contribute significantly to the development of effects on N availability and cycling. We compared soil N dynamics in experimental grassland communities dominated by native perennial grasses (NP), exotic annual grasses (EA), and exotic perennial grasses (EP), as well as mixtures of the native perennial grasses with each exotic grass group (NP + EA and NP + EP). These groups differ from each other in subtle ways in traits likely to influence soil N cycling including annual productivity, allocation to roots versus shoots, litter production, litter chemistry, and degree of summertime activity. We found that ecosystem N dynamics were significantly different between the various species groups with the greatest differences occurring between EA plots and other community types: soils in EA plots had significantly lower rates of net N mineralization, net nitrification, and microbial biomass-N compared to either NP or NP + EA plots, and lower extractable nitrate in the spring compared to either NP or EP plots. The higher the proportion of productivity in a plot that derived from exotic species, particularly exotic annual species, the lower were the measured rates of net N mineralization. Stepwise regression analysis showed that vegetation productivity was the best predictor of N cycling metrics: the higher the productivity, the higher the rates of net mineralization and nitrification, and microbial biomass-N. We conclude that species' abundance and productivity were strong controlling factors in the development of differences in ecosystem N dynamics between our experimental treatments. Inclusion of relative proportion of productivity contributed by community members in models of the development of species effects will likely aid in predicting when and where invasive species will alter ecosystem N dynamics.

Flow regulation reduces native plant cover and facilitates exotic invasion in riparian wetlands

Summary 1. River regulation and exotic plant invasion threaten riverine ecosystems, and the two often co‐occur. By altering water regimes, flow regulation can facilitate plant invasion by providing conditions that directly benefit invading species, or by reducing competition from native species unsuited to the modified conditions. Integrating water and weed management has the potential to limit riparian plant invasion and maximize the ecological benefit of environmental flows. 2. We surveyed plant communities and modelled flood histories of 24 riparian wetlands along the regulated River Murray, south‐eastern Australia. There were no suitable control rivers, so we compared modelled pre‐ and post‐regulation hydrological data to quantify hydrological change in the study wetlands. Regression analyses revealed relationships between hydrological modification and cover of native non‐weed, native weed and exotic weed groups and 10 individual species. 3. Exotic cover was highest and native non‐weed cover lowest in wetlands that had experienced the greatest change in hydrology – a reduction in peak flow. Native weeds did not respond to hydrological modification indicating that exotic species’ success was not reliant on their generalist characteristics. 4. By altering habitat filters, hydrological modification caused a decline in amphibious native non‐weed species cover and simultaneously provided drier conditions that directly favoured the exotic species group dominated by terrestrial species. Exotic species were potentially further assisted by human‐mediated dispersal. 5. Species and functional diversity was inversely related to exotic cover. By shifting the balance between native and exotic taxa and changing community functional composition, flow regulation may disrupt the ecological function and ecosystem services of floodplain wetlands. 6. Synthesis and applications. Worldwide, flow regulation has led to riverine ecosystems becoming more terrestrial. The success of most introduced plants relies on minimal inundation. In this study, flood magnitude was more important than frequency, timing, or duration for wetland flora because it reflects spatial extent and depth of flooding. Augmenting natural spring floods with environmental flows will kill terrestrial weeds and facilitate native macrophyte growth. Combined with strategies for managing particular amphibious weeds, we recommend flows of 117 000–147 000 ML day−1 for at least 2 days every 10 years for River Murray wetland weed management.

On some exotic Schottky groups

We construct a Cartan-Hadamard manifold with pinched negative curvature whose group of isometries possesses divergent discrete free subgroups with parabolic elements that do not satisfy the so-called 'parabolic gap condition'' introduced in [4]. This construction relies on the comparaison between the Poincaré series of these free groups and the potential of some transfer operator which appears naturally in this context.

A group-theoretic approach to a family of 2-local finite groups constructed by Levi and Oliver

We extend the notion of a p-local finite group (defined in [BLO03]) to the notion of a p-local group. We define morphisms of p-local groups, obtaining thereby a category, and we introduce the notion of a representation of a p-local group via signalizer functors associated with groups. We construct a chain G = (G_0 → G_1 → ...) of 2-local finite groups, via a representation of a chain G^* = (G_0 → G_1 → ...) of groups, such that G_0 is the 2-local finite group of the third Conway sporadic group Co_3, and for n > 0, G_n is one of the 2-local finite groups constructed by Levi and Oliver in [LO02]. We show that the direct limit G of G exists in the category of 2-local groups, and that it is the 2-local group of the union of the chain G^*. The 2-completed classifying space of G is shown to be the classifying space B DI(4) of the exotic 2-compact group of Dwyer and Wilkerson [DW93].

Using multi-scale species distribution data to infer drivers of biological invasion in riparian wetlands

Aim:? Biological invasion is a major conservation problem that is of interest to ecological science. Understanding mechanisms of invasion is a high priority, heightened by the management imperative of acting quickly after species introduction. While information about invading species’ ecology is often unavailable, species distribution data can be collected near the onset of invasion. By examining distribution patterns of exotic and native plant species at multiple spatial scales, we aim to identify the scale (of those studied) that accounts for most variability in exotic species abundance, and infer likely drivers of invasion. Location:? River Murray wetlands, south-eastern Australia. Methods:? A nested, crossed survey design was used to determine the extent of variation in wetland plant abundance, grazing intensity and water depth at four spatial scales (reaches, wetland clumps, wetlands, wetland sections), and among three Depth-strata. We examined responses of exotic and native species groups (grouped into terrestrial and amphibious taxa), native weeds and 10 individual species using hierarchical ANOVA. Results:? As a group dominated by terrestrial taxa, exotic species cover varied at reach-, wetland- and section-scales. This likely reflects differences in abiotic characteristics and propagule pressure at these scales. Groups based on native species did not vary at any scale examined. Cover of 10 species mostly varied among and within wetlands (patterns unrelated to species’ origin or functional group), but species’ responses differed, despite individual plants being similar in size. While flora mostly varied among wetlands, exotic cover varied most among reaches (26%), which was attributed to hydrological modification and human activities. Main conclusions:? Multi-scale surveys can rapidly identify factors likely to affect species’ distributions and can indicate where future research should be directed. By highlighting disproportionate variation in exotic cover among reaches, this study suggests that flow regulation and human-mediated dispersal facilitate exotic plant invasion in River Murray wetlands.

Relationships between avian diversity, neighborhood age, income, and environmental characteristics of an urban landscape

Maintaining biodiversity in urbanizing landscapes has become a top conservation priority. We examined variation in bird communities across a diverse array of urban and suburban neighborhoods in the Chicago, Illinois, metropolitan region. Rather than taking the usual approach of focusing solely on natural features of the urban landscape, we investigated how urban bird communities were related to neighborhood age and income, as well as environmental characteristics. We found that median housing age was strongly related to avian species richness, with newer neighborhoods supporting more species. Housing age was an important correlate of abundance for several species as well as abundance of exotic, migratory, and non-migratory species groups. Per capita income was inversely related to richness of native bird species and positively related to exotic richness. Total richness was higher in urban sites with undeveloped patches and heterogeneous land cover types; moreover, richness decreased with increasing distance from natural areas greater than 1 km 2. Our findings suggest that bird richness is enhanced both by small patches of natural land within the urban matrix and by close proximity to large natural preserves. Furthermore, these results suggest that investigating a combination of abiotic and environmental features of the built landscape, rather than focusing solely on environmental features, may provide a more complete understanding of the factors influencing avian diversity in human-dominated landscapes.

Genetic Contribution of Introduced Varieties to Wheat Breeding in China Evaluated Using Microsatellite Markers

The objective of the study was to understand the genetic contribution of introduced varieties to Chinese wheat ( Triticum aestivum L.) breeding at the genomic level. A total of 44 representative accessions, consisting of 11 introduced parents from the 1950s to the 1970s and 33 Chinese modern varieties that were released in different years, were evaluated using 363 microsatellite markers. The introduced accessions contained 76.3% of the alleles presented in the Chinese varieties examined. Comparing the genetic diversity of grouped accessions based on their origins and released ages, the exotic group had the largest average allele number per locus (3.9), followed by the 1980s group (3.5), and the 1960s and the 1970s groups had the smallest value (2.9 and 3.0, respectively). Analysis of genetic distance among groups showed an accordant result to that on allelic diversity. According to the allelic frequency, 33 loci of introduced varieties were selected preferentially and transmitted to Chinese accessions, and the allelic frequencies at these loci were all larger than 70%. These loci played an important role in the improvement of wheat varieties in China. The objective of the study was to understand the genetic contribution of introduced varieties to Chinese wheat ( Triticum aestivum L.) breeding at the genomic level. A total of 44 representative accessions, consisting of 11 introduced parents from the 1950s to the 1970s and 33 Chinese modern varieties that were released in different years, were evaluated using 363 microsatellite markers. The introduced accessions contained 76.3% of the alleles presented in the Chinese varieties examined. Comparing the genetic diversity of grouped accessions based on their origins and released ages, the exotic group had the largest average allele number per locus (3.9), followed by the 1980s group (3.5), and the 1960s and the 1970s groups had the smallest value (2.9 and 3.0, respectively). Analysis of genetic distance among groups showed an accordant result to that on allelic diversity. According to the allelic frequency, 33 loci of introduced varieties were selected preferentially and transmitted to Chinese accessions, and the allelic frequencies at these loci were all larger than 70%. These loci played an important role in the improvement of wheat varieties in China.

On the homotopy type of the non-completed classifying space of a p-local finite group

We establish sufficient conditions for the nerve of the centric linking system of a p-local finite group (S, ℱ, ℒ) to have the homotopy type of an Eilenberg-MacLane space K(Γ, 1) for a group Γ which contains S. We prove that in this situation the entire p-local finite group can be reconstructed from Γ. Our theorem applies to many of the known examples of exotic p-local finite groups.

Exotic group actions on simply connected smooth 4-manifolds

We produce infinite families of exotic actions of finite cyclic groups on simply connected smooth 4-manifolds with nontrivial Seiberg-Witten invariants.

Field Manual of Techniques in Invertebrate Pathology: Application and Evaluation of Pathogens for Control of Insects and other Invertebrate Pests, 2nd edn ‐ Edited by L. Lacey & H. K. Kaya

<i>Field Manual of Techniques in Invertebrate Pathology: Application and Evaluation of Pathogens for Control of Insects and other Invertebrate Pests</i>, 2nd edn ‐ Edited by L. Lacey &amp; H. K. Kaya

Plant responses to agricultural intensification

Summary 1. A large proportion of the world's land surface is extensively managed for livestock production. In areas where livestock systems are becoming more intensive, a major challenge is to predict those plant species likely to decline, persist or increase as a result of agricultural intensification. 2. Most analyses develop inferences for frequent or abundant species, or rely on intensive studies of single species. A promising approach is to identify plant traits related to disturbance to enable inference to be made about changes in plant community composition. We used a Bayesian hierarchical model to analyse the response to agricultural intensification of 494 plant species of pastures and woodlands in southern Australia, and to identify how simple species' traits (life form, growth form and species origin) influence those responses. 3. The probability of occurrence of most species declined along the two intensification gradients, grazing intensity and soil phosphorous concentration, although the occurrence of a greater proportion of species was negatively correlated with soil phosphorous. Responses could be broadly predicted from both plant origin and plant traits, in particular growth form. 4. Native perennial geophytes, ferns and shrubs were most negatively affected by both gradients, while exotic annual grasses and forbs were more tolerant. Along the phosphorous gradient, 24 of the 30 most negatively affected plant species were native geophytes. Mean within-group responses masked considerable within- and between-species variation, particularly for the exotic species group which included species that responded both negatively and positively to intensification. 5. Synthesis and applications. The hierarchical model described here provides a powerful method for estimating individual plant responses and identifying how species' traits influence those responses. Plant species native to southern Australia are sensitive to grazing and phosphorous apparently due to a shared evolutionary history of low grazing intensity and low phosphorous soils. Invading exotic plants have faced strongly contrasting ecological filters, leading to a greater diversity of responses. Where grazing systems have been most intense, a small suite of exotics dominate. Maintaining native and functional plant diversity will necessitate limits being placed on intensive livestock management systems.

Genetic Diversity in Main Parents of Sweetpotato in China as Revealed by ISSR Markers

Sixty-two main parents of sweetpotato [ Ipomoea batatas (L.) Lam.] in China were assessed using inter-simple sequence repeat (ISSR) markers to understand their genetic differences. Seventeen ISSR primers generated 490 polymorphic bands with an average of 28.8 polymorphic bands per primer, indicating that ISSR marker was efficient to analyze the genetic diversity of sweetpotato. Wide genetic distances (GDs), ranged from 0.158 to 0.924 with an average of 0.574, were observed among the tested cultivars. The cluster analysis classified the cultivars into domestic and exotic groups using unweighted pair group method with arithmetic mean. The domestic group was distant from the exotic group in terms of GD. The Asian cultivars had higher genetic diversity than the African and American cultivars. The cultivars from Chinese mainland, which had the smallest GD (0.419), were genetically close to the cultivars from Taiwan, China, whereas they had relative larger differences with the cultivars originated from other Asian countries. The results suggested that the crosses between domestic and exotic parents should be emphasized in sweetpotato breeding in China.

The linking systems of the Solomon 2-local finite groups are simply connected

A p-local finite group is an algebraic structure which includes two categories, a fusion system and a linking system, which mimic the fusion and linking categories of a finite group over one of its Sylow subgroups. The p-completion of the geometric realization of the linking system is the classifying space of the finite group. In this paper, we study the geometric realization, without completion, of linking systems of certain exotic 2-local finite groups of which the existence was predicted by Solomon and Benson, and prove that they are all simply connected.

Fillings, finite generation and direct limits of relatively hyperbolic groups

We examine the relationship between finitely and infinitely generated relatively hyperbolic groups. We observe that direct limits of relatively hyperbolic groups are in fact direct limits of finitely generated relatively hyperbolic groups. We combine this observation with known results to prove the Strong Novikov Conjecture for some exotic groups constructed by Osin.

Exotic normal fusion subsystems of general linear groups

We classify the saturated fusion subsystems of index prime to p of the general linear group over 𝔽q over a Sylow p-subgroup, where q is a prime power prime to an odd prime p. In this classification we obtain some of the exotic p-local finite groups discovered by Broto and Møller as saturated fusion subsystems of general linear groups.

An integrated approach to understanding Apollo 16 impact glasses: Chemistry, isotopes, and shape

Abstract The major‐ and minor‐element abundances were determined by electron microprobe in 1039 glasses from regoliths and regolith breccias to define the compositional topology of lunar glasses at the Apollo 16 landing site in the central highlands of the Moon. While impact glasses with chemical compositions similar to local materials (i.e., Apollo 16 rocks and regoliths) are abundant, glasses with exotic compositions (i.e., transported from other areas of the Moon) account for up to ˜30% of the population. A higher proportion of compositionally exotic, angular glass fragments exists when compared to compositionally exotic glass spherules. Ratios of non‐volatile lithophile elements (i.e., Al, Ti, Mg) have been used to constrain the original source materials of the impact glasses. This approach is immune to the effects of open‐system losses of volatile elements (e.g., Si, Na, K). Four impact glasses from one compositionally exotic group (low‐Mg high‐K Fra Mauro; lmHKFM) were selected for 40Ar/39 Ar dating. The individual fragments of lmHKFM glass all yielded ages of ˜3750 ± 50 Ma for the time of the impact event. Based on the petrography of these individual glasses, we conclude that the likely age of the impact event that formed these 4 glasses, as well as the possible time of their ballistic arrival at the Apollo 16 site from a large and distant cratering event (perhaps in the Procellarum KREEP terrain) (Zeigler et al. 2004), is 3730 ± 40 Ma, close to the accepted age for Imbrium.

Journey to the West

What is often called the first Japanese embassy to Europe was actually a publicity stunt conceived in 1582 by Alexandro Valignano, the inspector of the Portuguese-sponsored Asian missions of the Society of Jesus. Four teenagers from Kyushu were paraded through Portugal, Spain, and Italy-performers and audience at the same time in a theatrical production designed to display the capabilities of the Japanese before influential circles of Catholic Europe while imbuing the Japanese with the idea of the superiority of European civilization under the aegis of the Catholic Church. After returning to their native country in 1590, all four joined the Jesuit order. Three served the cause of Christianity faithfully. The fourth, Miguel Chijiwa, apostatized and derided all that he had been taught to hold sacred. He is the narrator of the scurrilous piece of anti-Christian fiction Kirishitan kanagaki, a fantasy novel avant-la-lettre that deserves much greater attention than it has received. Its multifaceted deployment of European legendary materials makes it a challenge to students of comparative culture. KEYWORDS: Miguel Chijiwa - Mancio Ito - Martinho Hara - Juliao Nakaura - Alexandro Valignano - Dialogue about the Mission of the Japanese Ambas-sadors- Kirishitan kanagaki (ProQuest-CSA LLC: ... denotes non-USASCII text omitted.) ON a June day in 1585, an exotic group paid the Umbrian hill town of Montefalco a visit. What was billed as a Japanese embassy was passing through. Four teenage boys from Kyushu were the stars of this traveling show-Mancio Ito, cast in the role of the ambassador of the King of Bungo; Miguel Chijiwa, assigned the part of the envoy of the King of Arima and the Prince of Omura; and Martinho Hara and Juliao Nakaura, featured as the noble companions of the other two. Members of the Society of Jesus, acting in the indispensable capacity of the youths' mentors and chaperons, accompanied them. An account of these country boys' journey to the West and back to Asia, composed some years later in the form of an elaborate colloquy among them and two of their Japanese Christian friends (actually, it is not much of a colloquy, as the dialogue is dominated by long speeches scripted for Miguel Chijiwa), sums up the object of this brief visit as follows:1 We passed through a town called Montefalco, where we were gladdened extraordinarily by the sight of the sacred cadaver of...Saint Clare, who bears a cognomen derived from the name of that town. Not only is her venerable cadaver uncorrupted and intact to the present day, but her heart is marked by the images of Christ crucified and other mysteries. Moreover, in her heart were found three globes, similar in the highest degree to one another, which are endowed with a supernatural property, so that the weight of all three together is exactly the same as that of each by itself, and there is no difference whether you place one of them on one dish of a balance and two on the other or, then again, put all together in the same dish. In this we perceived the manifest sign of the most holy Trinity, each person of which singly, no less than the three persons jointly, is replete with the same nature, power, and majesty. This supreme mystery of our faith is what this Saint (Diua haec) revered above all in her soul. Clare of Montefalco (1268-1308) was not yet a saint, properly speaking, at the time of the Japanese youths' call at her shrine, as her case for canonization, formally initiated the year after her death, failed for obscure reasons to make progress and was not to be brought to a successful conclusion until 1881. She was, however, the object of a substantial local and regional cult. As a child, she had entered a religious community headed by her sister, whom she would eventually succeed as abbess. Her life in the convent was not circumscribed, however, by the routine practice of monastic virtues. Clare was known for her intense asceticism, her ecstatic mystical experiences, and the ardency of her identification with the crucified Christ. …

Predicting transgressive segregants in early generation using single seed descent method-derived micro-macrosperma genepool of lentil (Lens culinaris Medikus)

In a self-fertilised crop like lentil, the identification of transgressive segregants for economically important trait such as seed yield is an important aspect of any practical breeding programme. The prediction of expected transgressive segregants in F1 generation obtained as a ratio of additive genic effect [d] and additive variance (D) i.e. [d]/√D was studied in 28 crosses of lentil generated in a diallel fashion involving four parents each of macrosperma (exotic) and microsperma (Indian) types, respectively, resulting in three hybridization groups. The seed material advanced to F2, F3 and F4 generations through single seed descent method was evaluated to determine the observed transgressive segregants for seed yield/plant. The observed frequency of crosses showing more than 20% transgressive segregants in F2 to F4 generations were exhibited in 9(32%) crosses, of which 7(77%) crosses were of macrosperma × microsperma type. Genotypes Precoz and HPL-5 of the exotic group (macrosperma) produced maximum number of transgressive segregants with the genotypes L-259, L-4145 and PL-406 of the Indian origin (microsperma). Goodness of fit (non-significant χ2 value) in F2 generation was observed for 19(68%) crosses of the total genepool, out of which 9(56%) crosses each in F3 and F4 generation belonged to the macrosperma × microsperma group, depicting it as the gene pool of paramount importance to obtain maximum transgressive segregants, therefore establishing the efficacy of the method used.

Exotic Galileian group in field theory

The exotic Galileian group is realized as a symmetry group of a family of nonrelativistic field theories on the noncommutative plane. This was obtained in a unique way consistent with the Seiberg—Witten mapping. The symmetry group of the free model is analyzed and a characterization of the class of the self-interacting theories is given.