Establishment Of Colonies Research Articles

Morphometric trait differentiation between a wild and a mass-reared population of Anastrepha fraterculus (Diptera: Tephritidae)

The South American fruit fly Anastrepha fraterculus (Wiedemann) is an important pest in many countries. The sterile insect technique is an effective method of controlling Ceratitis capitata (Wiedemann) in Argentina and has been proposed for use against A. fraterculus. Because this technique relies on sterile mass-reared males mating with wild females, it is essential to verify that artificial rearing does not reduce male mating competitiveness. Several morphometric characters were evaluated to detect differences between a wild population and a laboratory strain that was derived from it and reared artificially since 1997. Eight morphometric traits were analysed as indicators of body size, head shape and potential mobility: Thorax Length, Head Width, Face Width, Eye Length, Wing Length, Wing Width, Third Tibia Length and Femur Length. The results were analysed using multivariate analysis of variance, linear multiple regression and logistic multiple regression. In general, laboratory flies were larger than wild ones (possibly because the larval diet was supplied ad libitum). Laboratory males had significantly larger Head Width and Eye Length and a smaller Wing Width than wild males. Laboratory females differed from wild ones only by having narrower wings. These results could be due to environmental and genetic factors, or as a consequence of genetic drift (for the latter) during colony establishment plus gradual adaptation to laboratory conditions, where flight ability is most likely less important (resources are found easily at close distances). Also, short-distance interactions among individuals are more frequent in a colony, possibly favouring increased facial trait sizes by sexual selection. Because long-term morphological changes could represent the beginning of intraspecific differentiation, they should probably be worthy of some consideration if a large mass-rearing colony is established.

The Greek presence on the east coast of the Iberian Peninsula: Colonial establishments and rhythms of trade with Iberian societies

The Greek presence along the Mediterranean coastline of the Iberian Peninsula is a phenomenon that we can trace from the Archaic Period until the beginning of the Roman Empire. Even though the earliest Greek trade contacts with the west have been dated from the 8th century BC, it was not until the 6th century BC, when the Phocaeans founded Massalia and Emporion, that these contacts began to intensify in the northeast and eastern seaboard of the Iberian Peninsula. Throughout the 5th century BC, the Greek commercial contacts with the Iberian world and the role of Emporion solidified until they reached their peak in the 4th century BC, when Greek products spread massively around the coastline, dovetailing with the rise in Punic trade and broader Greek settlement in the territory with the newly-founded Massalian settlements of Alonis and Hemeroskopeion (known solely through sources) and Rhode (Roses), which would export its own ceramics in the 3rd century BC.

Characterization of the Neurospora crassa cell fusion proteins, HAM-6, HAM-7, HAM-8, HAM-9, HAM-10, AMPH-1 and WHI-2.

Intercellular communication of vegetative cells and their subsequent cell fusion is vital for different aspects of growth, fitness, and differentiation of filamentous fungi. Cell fusion between germinating spores is important for early colony establishment, while hyphal fusion in the mature colony facilitates the movement of resources and organelles throughout an established colony. Approximately 50 proteins have been shown to be important for somatic cell-cell communication and fusion in the model filamentous fungus Neurospora crassa. Genetic, biochemical, and microscopic techniques were used to characterize the functions of seven previously poorly characterized cell fusion proteins. HAM-6, HAM-7 and HAM-8 share functional characteristics and are proposed to function in the same signaling network. Our data suggest that these proteins may form a sensor complex at the cell wall/plasma membrane for the MAK-1 cell wall integrity mitogen-activated protein kinase (MAPK) pathway. We also demonstrate that HAM-9, HAM-10, AMPH-1 and WHI-2 have more general functions and are required for normal growth and development. The activation status of the MAK-1 and MAK-2 MAPK pathways are altered in mutants lacking these proteins. We propose that these proteins may function to coordinate the activities of the two MAPK modules with other signaling pathways during cell fusion.

Negative Effects of Azteca Ants on the Distribution of the Termite Neocapritermes braziliensis in Central Amazonia

Termites play important roles in tropical ecosystem functioning, and their evolutionary success has been linked to their defense mechanisms. However, microhabitat overlap with potential aggressors may constrain their distribution and thus, their environmental impacts on an ecological timescale. We investigated a possible negative effect of abundant generalist ants (Azteca sp.) on the termite Neocapritermes braziliensis. Both taxa frequently build their nests attached to trees. We determined the densities of their active nests in 10 plots (250 x 10 m) systematically distributed over 5 km2 in central Amazonia, Brazil, and recorded their co-occurrence in individual trees. Using generalized nonlinear modeling in a Bayesian framework, we found good support for a negative effect of Azteca’s nest density on N. braziliensis’. This effect conformed to a power law, and accounted for more than half of the variation in the termite’s nest density (r2 = 0.56). Additionally, of all counted N. braziliensis mounds, only 1.08 percent was attached to trees also hosting Azteca. Such patterns may have arisen due to N. braziliensis’ inability to establish new nests within Azteca territories, or predation by ants on established colonies of the termite. We suggest that even non-strictly termitophagous ant species may have important impacts on termite populations and, consequently, on their roles in nutrient cycling and ecosystem engineering.

Use of plastic tips in artificial feeding of Dermacentor (Anocentor) nitens females Neumann, 1897 (Acari: Ixodidae)

The establishment of laboratory colonies of ticks is often hampered by their lack of adaptation to alternative hosts. The aim of this study was to artificially feed partially engorged Dermacentor (Anocentor) nitens females through plastic tips, and to identify what are the optimal conditions of application of this technique to get as much as possible close to the natural conditions. The technique of artificial feeding through plastic tips allowed the engorgement of D. nitens ticks to a final weight within the normal range for the species.

Generation of rat-induced pluripotent stem cells from a new model of metabolic syndrome.

We recently characterized DahlS.Z-Leprfa/Leprfa (DS/obese) rats, derived from a cross between Dahl salt-sensitive rats and Zucker rats, as a new animal model of metabolic syndrome (MetS). Although the phenotype of DS/obese rats is similar to that of humans with MetS, the pathophysiological and metabolic characteristics in each cell type remain to be clarified. Hence, the establishment of induced pluripotent stem cells (iPSCs) derived from MetS rats is essential for investigations of MetS in vitro. Reports of rat iPSCs (riPSCs), however, are few because of the difficulty of comparing to other rodents such as mouse. Recently, the advantage of using mesenchymal stromal cells (MSCs) as a cell source for generating iPSCs was described. We aimed to establish riPSCs from MSCs in adipose tissues of both DS/obese rats and their lean littermates, DahlS.Z-Lepr+/Lepr+ (DS/lean) rats using lentivirus vectors with only three factors Oct4, Klf4, and Sox2 without c-Myc. The morphology, gene expression profiles, and protein expression of established colonies showed embryonic stem cell (ESCs)-like properties, and the differentiation potential into cells from all three germ layers both in vitro and in vivo (teratomas). Both riPSCs became adipocytes after induction of adipogenesis by insulin, T3, and dexamethasone. Real-time PCR analysis also revealed that both riPSCs and the adipose tissue from DS/obese and DS/lean rats possess similar expression patterns of adipocyte differentiation-related genes. We succeeded in generating riPSCs effectively from MSCs of both DS/obese and DS/lean rats. These riPSCs may well serve as highly effective tools for the investigation of MetS pathophysiology in vitro.

Spatial patterns of social spider colonies in Namibia reflect habitat features and dispersal modes

Colonies of web building social spiders may persist at a site for several generations; therefore, their placement in the habitat is critical for survival. This study focuses on the development of spatial distribution patterns by means of different dispersal modes in a social spider species (Stegodyphus dumicola Pocock, 1898, Eresidae) in central Namibia. Social spiders disperse varying distances from the parent colony by ballooning or short distances by budding. Using spatial point pattern analyses we aimed to identify the dispersal pattern from source colonies and what drivers affect the resulting distribution patterns. The distribution of suitable vegetation constrained pattern development in the three study plots with mapped colonies. In a plot with isolated large trees, colonies were only aggregated over short distances and the average cluster size was small. First generation colonies were established within the same clusters by solitary ballooning females. In the two study plots with more evenly distributed shrubs, clusters were generally larger and new colonies were formed mainly by budding. In these plots, newly established colonies and older source colonies were either associated in suitable habitat patches or segregated from each other. Possible explanations include high mortality of either older colonies and replacement by newly established colonies or of dispersers in the vicinity of established colonies, or selection of “empty” sites by dispersing individuals based on cues from conspecific colonies. In conclusion, both the distribution of the vegetation and the mode of dispersal may explain the development of spatial patterns in S. dumicola. Our results highlight the importance of spatial pattern analyses for inferring underlying causes of distribution of sedentary organisms.

Quantifying metastatic inefficiency: rare genotypes versus rare dynamics

We introduce and solve a ‘null model’ of stochastic metastatic colonization. The model is described by a single parameter θ: the ratio of the rate of cell division to the rate of cell death for a disseminated tumour cell in a given secondary tissue environment. We are primarily interested in the case in which colonizing cells are poorly adapted for proliferation in the local tissue environment, so that cell death is more likely than cell division, i.e. . We quantify the rare event statistics for the successful establishment of a metastatic colony of size N. For , we find that the probability of establishment is exponentially rare, as expected, and yet the mean time for such rare events is of the form while the standard deviation of colonization times is . Thus, counter to naive expectation, for , the average time for establishment of successful metastatic colonies decreases with decreasing cell fitness, and colonies seeded from lower fitness cells show less stochastic variation in their growth. These results indicate that metastatic growth from poorly adapted cells is rare, exponentially explosive and essentially deterministic. These statements are brought into sharper focus by the finding that the temporal statistics of the early stages of metastatic colonization from low-fitness cells () are statistically indistinguishable from those initiated from high-fitness cells (), i.e. the statistics show a duality mapping . We conclude our analysis with a study of heterogeneity in the fitness of colonising cells, and describe a phase diagram delineating parameter regions in which metastatic colonization is dominated either by low or high fitness cells, showing that both are plausible given our current knowledge of physiological conditions in human cancer.

Effects of insemination and blood-feeding on locomotor activity of Aedes albopictus and Aedes aegypti (Diptera: Culicidae) females under laboratory conditions

BackgroundDengue is an arbovirus disease transmitted by two Aedes mosquitoes: Ae. aegypti and Ae. albopictus. Virgin females of these two species generally show a bimodal and diurnal pattern of activity, with early morning and late afternoon peaks. Although some studies on the flight activity of virgin, inseminated and blood-fed Ae. aegypti females have been carried out under laboratory conditions, little is known about the effects of such physiological states on the locomotor activity of Ae. albopictus and Ae. aegypti females. The aim of this study was to analyze, under laboratory conditions, the effects of insemination and blood-feeding on the locomotor activity of Ae. albopictus and Ae. aegypti females under LD 12:12, at 25°C.MethodsBoth Ae. albopictus and Ae. aegypti females were obtained from established laboratory colonies. Control groups were represented by virgin/unfed Ae. albopictus and Ae. aegypti females. Experiments were conducted under laboratory conditions, using an activity monitor that registers individual activity every thirty minutes.ResultsVirgin/unfed Ae. albopictus and Ae. aegypti females showed a diurnal and bimodal pattern of locomotor activity, with peaks at early morning and late afternoon. Insemination and blood-feeding significantly decreased the locomotor activity of Ae. aegypti females, but inseminated/blood-fed Ae. aegypti and Ae. albopictus females showed a similar significant decrease on the locomotor activity compared to virgin/unfed females.ConclusionsThis study is the first demonstration of the effects of insemination and blood-feeding on the locomotor activity of Ae. albopictus and Ae. aegypti females under artificial conditions. Data suggest that Ae. albopictus and Ae. aegypti females respond in different ways to physiological status changes and such divergence between these two dengue vectors, associated with several ecological differences, could be related to the greater dengue vectorial capacity of Ae. aegypti in Americas in comparison to Ae. albopictus.

Whitefellas at the Margins

Within the context of the Australian higher education sector and the organisational interactions facilitated by a university, the politics of Anglo-Australian identity continues to limit the ability of ‘whitefella’ Australians to engage with Indigenous people in a way that might be said to be truly ethical and self-transformative. Instead, the identity politics of Anglo-Australia, a politics that originates in the old colonial stories of the 19th century, continues to function in a way that marginalises those individuals who choose to engage in a way that goes beyond the organisational rhetoric of government and civil institutions in promoting causes such as reconciliation and ‘closing the gap’. The history of Australian colonialism teaches us that, when a deep and productive engagement between settler and native has occurred, the stability of Anglo-Australian identity is destabilised as the colonial establishment is reminded of Indigenous dispossession and the moral and legal legitimacy of the contemporary Australian state become subject to problematic questions that arise from this fact of Australian history. Framing the contemporary context of change and resistance, the authors discuss the importance of inclusive institutional practice, in the quest for a democratic modelling that points to a pathway for a truer recognition, acceptance and inclusion of Indigenous peoples in the ‘mainstream’ of Australian university life.

Demographic and Breeding Performance of a New Kelp GullLarus dominicanusColony in Patagonia, Argentina

Fil: Lisnizer, Nora. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Nacional Patagonico; Argentina

In-vitro developmental studies of Cheilanthes farinosa (Forssk.) Kaulf. (Pteridaceae)

Developmental pattern of spore germination, gametophyte growth, differentiation, sex ontogeny and development of
 sporophytes of Cheilanthes farinosa were studied in in-vitro conditions. The spore germination and prothallial development are found to be of Vittaria type and Ceratopteris type, respectively. The species seems be a good colonizer in nature. A considerable numbers of sporophytes were produced through intra- and intergametophytic selfing in culture. Sporophyte
 production efficiency was observed to be 8% in isolate population and 12% in composite gametophyte population.
 Genetic barriers and over-exploitation for ornamental purposes causes the reduction in the population size. Protection of this taxon in the natural habitat is urgently required as it grows well in barren and disturbed habitats and help in the establishment of colonies of other plants.

Colony founding by the ant Myrmelachista flavocotea

Identifying key life history characters is crucial to understanding the selective forces that influence species interactions and reciprocal evolution. We often know little about colony-founding behavior and colony structure of ants involved in obligate interactions with plants. Here, I describe colony-founding behavior of Myrmelachista flavocotea (Formicidae: Formicinae) on its obligate host plants Ocoteaatirrensis and O. dendrodaphne (Lauraceae) in a lowland Caribbean rainforest at La Selva Biological Station, Costa Rica. Ocotea seedlings produce specialized nodules on the main stem that are used as domatia by founding queens. In this study, Ocotea seedlings were colonized by multiple haplometrotically founding M.flavocotea queens. Mature colonies typically had only a single queen, apparently as a result of secondary monogyny. The number of foundress queens per tree was positively correlated with seedling height and stem diameter (nesting space) at time of colony founding. The extent to which foundress queens cooperate in colony founding is not known. Nonetheless, colony establishment by multiple foundress queens may be critical in ensuring the successful founding by at least one queen, thus allowing the perpetuation of the Myrmelachista-Ocotea interaction.

Defining the “flesh” of the black soldier in colonial Sierra Leone: background to the gunners' mutiny of 1939

Instances of discontent within colonial military establishments in Africa have largely been ignored by historians of colonial Africa. The heavy focus on the incidence of coups in the historiography has helped to obscure the privations suffered by African soldiers in colonial armies. Using the Sierra Leone experience, this study draws on hitherto untapped archival material to examine the complex causes of the “Gunners' Mutiny” of January 1939. While showing that the causes of mutinies could be significantly nuanced, the study helps to bridge a vital gap in Sierra Leone's history.

Religion and Capital Punishment in the United States

AbstractReligion and the death penalty have long been linked in the United States, from colonial establishments that used biblical law as one basis for criminal statutes to the contemporary use of religion to support or oppose executions. This article begins by analyzing the literature on these links at the most abstract before using religiously motivated opposition to capital punishment to survey the history and historiography on the subject. It then looks at how religious institutions engage the issue before bringing the discussion into the courtroom to look at how religion impacts the legal process and how this has been studied. The article concludes by suggesting some avenues for future research.

‘Preaching Disaffection’ in the Presbyterian Atlantic: Jotham Blanchard and the Reform Crisis in Scotland and Nova Scotia, c. 1827–37

In the 1820s and ’30s Jotham Blanchard (1800–38), assemblyman for Pictou, Nova Scotia, launched a reform campaign against the Nova Scotian government. With the help of his mentor, the Rev. Thomas McCulloch, a Presbyterian missionary from Scotland, Blanchard attacked the colonial establishment for its failure to support the Pictou Academy, a college of higher learning for religious dissenters. Connected to a transatlantic denominational information web, Blanchard and McCulloch were inspired by the radical ecclesiology of the Scottish United Secession Church, with which McCulloch was affiliated. In 1831 Blanchard travelled to Britain to lobby the Colonial Office. There he was aided by the ministers of the United Secession, currently embroiled in their own local campaign in support of the Reform Bill. Blanchard's visit impacted on the domestic scene and the two campaigns became closely interwoven. Unfortunately for Blanchard his mission failed and he was written out of Nova Scotian history. Colonial historiography, concerned with celebrating the role of local heroes in the struggle for national self-determination, has focused overwhelmingly on the legacy of Joseph Howe, the triumphant champion of responsible government. Situating the Nova Scotian campaign within a transatlantic context, this article resurrects Blanchard's career and underlines its importance.

Dispersing hemipteran vectors have reduced arbovirus prevalence

A challenge in managing vector-borne zoonotic diseases in human and wildlife populations is predicting where epidemics or epizootics are likely to occur, and this requires knowing in part the likelihood of infected insect vectors dispersing pathogens from existing infection foci to novel areas. We measured prevalence of an arbovirus, Buggy Creek virus, in dispersing and resident individuals of its exclusive vector, the ectoparasitic swallow bug (Oeciacus vicarius), that occupies cliff swallow (Petrochelidon pyrrhonota) colonies in western Nebraska. Bugs colonizing new colony sites and immigrating into established colonies by clinging to the swallows' legs and feet had significantly lower virus prevalence than bugs in established colonies and those that were clustering in established colonies before dispersing. The reduced likelihood of infected bugs dispersing to new colony sites indicates that even heavily infected sites may not always export virus to nearby foci at a high rate. Infected arthropods should not be assumed to exhibit the same dispersal or movement behaviour as uninfected individuals, and these differences in dispersal should perhaps be considered in the epidemiology of vector-borne pathogens such as arboviruses.

Breaking the In Vitro Alveolar Type II Cell Proliferation Barrier while Retaining Ion Transport Properties

Alveolar type (AT)I and ATII cells are central to maintaining normal alveolar fluid homeostasis. When disrupted, they contribute to the pathogenesis of acute lung injury (ALI) and acute respiratory distress syndrome. Research on ATII cells has been limited by the inability to propagate primary cells in vitro to study their specific functional properties. Moreover, primary ATII cells in vitro quickly transdifferentiate into nonproliferative "ATI-like" cells under traditional culture conditions. Recent studies have demonstrated that normal and tumor cells grown in culture with a combination of fibroblast (feeder cells) and a pharmacological Rho kinase inhibitor (Y-27632) exhibit indefinite cell proliferation that resembled a "conditionally reprogrammed cell" phenotype. Using this coculture system, we found that primary human ATII cells (1) proliferated at an exponential rate, (2) established epithelial colonies expressing ATII-specific and "ATI-like" mRNA and proteins after serial passage, (3) up-regulated genes important in cell proliferation and migration, and (4) on removal of feeder cells and Rho kinase inhibitor under air-liquid interface conditions, exhibited bioelectric and volume transport characteristics similar to freshly cultured ATII cells. Collectively, our results demonstrate that this novel coculture technique breaks the in vitro ATII cell proliferation barrier while retaining cell-specific functional properties. This work will allow for a significant increase in studies designed to elucidate ATII cell function with the goal of accelerating the development of novel therapies for alveolar diseases.

The effects of brood ester pheromone on foraging behaviour and colony growth in apicultural settings

Brood ester pheromone (BEP) is a pheromone emitted by developing larvae in a honey bee (Apis mellifera) colony. It has been shown to have multiple potential commercially beneficial effects on worker physiology and behaviour, but like other bee pheromones, its effects are likely context dependent. To better understand the utility of BEP treatment, we examined the effects of BEP treatment in an apicultural setting (using a SuperBoost BEP treatment) in two contexts: in newly established colonies from bee packages in the summer and on large, established colonies in the autumn. We found that in small, newly established colonies, BEP treatment had no effect on colony growth (measured as brood cover). Further, BEP treatment decreased overall foraging activity and the proportion of pollen foragers. In established colonies, BEP had no effect on brood cover or foraging behaviour later in the season. Our data show that BEP treatments can change the behaviour of bees, but these can only translate into improved colony conditions if other factors are not limiting of colony performance.

British colonialism in East-Africa during nineteenth century

British colonialism in East-Africa during nineteenth century