Settlement Stage Research Articles

Bacterial-barnacle interaction: Potential of using juncellins and antibiotics to alter structure of bacterial communities

In preparation for studies using natural products to probe interactions between bacterial consortia and settlement stage barnacles, we isolated 16 strains of bacteria associated with barnacles and examined: (1) effects of films of bacterial isolates on barnacle settlement, and (2) bacteriostatic effects of juncellins and standard antibiotics. Bacteria were isolated from the biofilm associated withBalanus amphitrite. On the basis of morphological and biochemical characteristics, bacteria were classified into five major groups:Aeromonas, Alcaligenes, Flavobacterium, Pseudomonas, andVibrio. Barnacle settlement was inhibited by allVibrio films and 64% of the other isolates. No film stimulated barnacle settlement. Juncellins were approximately as potent as standard antibiotics for all bacterial species tested.Vibrio spp. were most resistant to juncellins.

Interfacing anthropology and epidemiology: The Bedouin Arab infant feeding study

This paper encapsulates a 10 year effort of multi-disciplinary research on the relationship between infant feeding, growth, and morbidity among the Negev Bedouin Arabs of Israel as they underwent a transition from semi-nomadism to urban settlement. The research team was multi-disciplinary including a nutritional epidemiologist and an anthropologist who both came to the study with previous experience in interdisciplinary work. The specific study objectives were (1) a description of infant feeding practices among Negev Bedouin Arab women at various stages of settlement, (2) an examination of the trend in these infant feeding practices, (3) a comparison of the extent to which different infant feeding practices are related to infant morbidity and growth after adjustment for exposure to social change and other covariates. The data collection took place in 1981–1983 and the analysis from 1984–1988. In this paper, two areas of the study are discussed in depth: the duration of exclusive breast feeding during the practice of the traditional postpartum 40 day rest period, and the development of a culture-specific scale of socioeconomic status. Through these examples, we highlight the use of ethnographic data and the merging of epidemiology and anthropology from hypothesis generation through data collection, data analysis and interpretation.

Baron Rothschild and the initial stage of Jewish settlement in Palestine (1882-1890): a different type of colonization?

The paper provides an overview of the first decade of the Jewish modern resettlement in Palestine, stressing Baron de Rothschild's part as the most prominent factor to shape the pioneer endeavour. An analysis of the Baron's commissioners reveals involvement in a variety of activities in the twelve agricultural settlements that were established then. This involvement began with planning and construction, and ended with agricultural guidance and supervision. Community services, especially education and health, are identified as the area in which Rothschild and his employees influenced the Jewish East European new settlers. The study then locates the specific Palestinian case and the Rothschild venture within the wide framework of European colonization in the nineteenth century. But is also identifies divergences in essential aspects such as the destination of the immigration, the character of the capital provided to the new settlement, and the relationship of the colonists with the local population and the authorities. Different ideological motives and spatial expressions distinguished the Jewish settlement in Palestine from other colonization.

Genetic studies of laboratory reared mussels, Mytilus edulis: heterozygote deficiencies, heterozygosity and growth

Offspring derived from several single pair matings and a mass mating of Mytilus edulis were cultured up to the juvenile stage in the laboratory. Samples were collected from the cultures at an early post- settlement (‘spat’) stage and again at the juvenile stage and were scored at up to nine enzyme loci using cellulose acetate and starch gel electrophoresis. An overall significant deficiency of heterozygotes was evident at the juvenile stage but not at the spat stage. Selection against heterozygotes (underdominance) is proposed as the cause. For each mating, shell lengths of juvenile mussels were measured and individuals were classed according to the number of loci at which they were heterozygous. No significant correlations were evident between heterozygosity class and either growth (shell length), or coefficient of variation of shell length. It is argued that these results provide support for the ‘associative overdominance’ rather than the ‘overdominance’ hypothesis as an explanation for heterozygosity/growth correlations in marine bivalves. These data also show that although heterozygosity and growth co-occur in most data sets from natural populations, they may have distinctly differing causes.

Physiological ecology of mussel larvae

Mussels produce large numbers of planktotrophic larvae that spend several weeks in the surface waters. This planktonic stage in the species' life-history is a critical phase concerned with feeding, growth and development, dispersal and the selection of a suitable site for the sedentary adult life. The process of development, from the small 70 μm egg through to the pediveliger larva (ca. 300 μm shell length) which settles and undergoes metamorphosis, is outlined. A maximum growth rate of ca. 12 μm day −1 in shell length results in a minimum larval life of 3 weeks at 18°C, but this can be extended to 3 months depending upon endogenous and exogenous (environmental) factors. However, the planktonic larval stage and the immediate post-settlement stage are accompanied by high mortality rates (ca. 0.1 to 0.2 day −1). Therefore any factor that reduces growth rate, and thus extends the period of larval development in the water column will have a major effect on mortality and the chances of survival to the settlement stage and beyond. The effects of environmental factors, such as food availability, temperature, oxygen concentration, salinity, and pollutants, on the processes of feeding, metabolism and growth of mussel larvae are reviewed and discussed in this context. Once the larvae have reached the pediveliger stage and are ‘competent’ to settle, then the process of settlement and metamorphosis can be delayed for up to 7 weeks until a suitable substratum is found. However, any delay will result in a further decline in the number of offspring surviving.

Initial contact, exploration and attachment of barnacle (Balanus amphitrite) cyprids settling in flow

Settlement responses of barnacle (Balanus amphitrite) cyprids to boundary-layer flows were examined in laboratory flume-experiments. The leading-edge configuration of flat plates was altered in order to manipulate flows without changing surface topography or freestream velocity. Settlement along the plates correlated strongly with downstream gradients in shear stress. Analyses of video images taken during the experiments indicate that cyprids first contact plates in regions where plate-ward advection is high, and subsequent exploratory movement along the plate is oriented with flow direction at the plate surface. After exploration, cyprids reject a surface more frequently in a fast flow (10 cm s−1 freestream velocity) than in a slow flow (5 cm s−1), but rejection occurs in shear stresses well below the threshold that would prevent attachment and exploration. A higher rejection rate does not result in lower settlement, however, since contact rate is higher in fast than slow flows. The movement of cyprids in flow thus appears to be a passive transport process during the initial contact stage of settlement, but an active behavioral response to flow direction and shear stress during later stages of exploration and attachment.

An assessment of the early stages of microfouling and corrosion of 70:30 copper nickel alloy in the presence of two marine bacteria

The early stages of bacterial settlement on 70:30 copper nickel alloy was followed by scanning electron microsocopy. Two strains of marine bacteria (Pseudomonas sp and Vibrio alginolyticus) isolated from polluted harbour sea water were used. The corrosion behaviour of the alloy was studied through corrosion potential measurements made in sterile and contaminated sea water. According to our results microbial colonisation of the metal surface occurs within the first 24 h for the two bacteria used. Well defined microbial colonies with localised corrosion underneath were seen by SEM after short periods of exposure. Corrosion attack seems to be closely related to passive film modification by the bacterial settlement.

Extragonadal distribution of primordial germ cells in the early chick embryo

Chick primordial germ cells (PGCs), after separation from the endoderm in early embryonic development, temporarily circulate via the blood vascular system and finally migrate into the gonadal anlagen. It has been noted by some authors that some PGCs are present in extragonadal sites in some vertebrates. In the present study, we examined the distribution and localization of PGCs in extragonadal sites in the chick embryo. PGCs were identified by periodic acid-Schiff staining with light microscopy. In embryos at stages 20-24 (PGCs are in the settlement stage in the gonadal primordium), approximately 20% of the total number of PGCs were observed in extragonadal regions. Approximately 90% of these ectopic PGCs were found in the head, mainly in the mesenchyme surrounding the neural tube. Even at stage 14 when PGCs were usually circulating in the blood vessels, some of the PGCs had emerged from the blood vessels and were detected in the extragonadal site. This pattern of distribution of ectopic PGCs in the head area is probably attributed to the earlier, dominant development of the capillary network, and to the sluggish capillary blood flow in that region, which allows intravascular PGCs to escape into the tissue.

Temporal and spatial variation in an island fish fauna

Elements of the reef fish fauna of a northeastern New Zealand island group was sampled over a 12-yr period. Sampling was divided into temporal and spatial elements. Temporal sampling in the form of annual surveys of labrid fishes was carried out at a single locality from 1974 until 1986. Surveys of a single species Suezichthys aylingi Russell were carried out from 1972 to 1986. Two series of surveys to analyse spatial pattern were carried out in 1982 and in 1984. The sampling targets were juvenile and adult rather than newly settled fishes. The degree of fluctuation in fish numbers over time reflected differences in geographic distribution and source areas amongst the different species. One element derived from northern subtropical areas declined from moderate numbers in 1974 to local extinction by 1979. The greatest numerical fluctuation (a 15-fold change) was observed in S. aylingi. Island populations of this species appeared to be derived from a discrete source area in northern New Zealand, the Three Kings Islands. Other species of labrids with established populations in northern New Zealand displayed moderate fluctuations. Labrids with southern distributions and abundant in adjacent coastal environments were rare at the islands and showed little variation in numbers. For most species, numerical fluctuations followed a similar course with enhanced numbers in the early 1970s, followed by marked decline, then showing a modest increase during the early 1980s. The patterns of numerical change correlated with both coastal sea temperatures and storm-induced disturbance to the habitat. The reef fish fauna showed marked spatial variation, often at very localized scales. Where temporal and spatial monitoring were combined the spatial patterns remained coherent over time. For most species examined spatial variation was of greater magnitude than temporal variation. We suggest that two mechanisms are involved. Inter-annual variation in numbers of recruits results from events in the oceanic environment of northeastern New Zealand. The spatial patterns were apparently driven by habitat selection at the settlement stage of reef fishes. Temporal variation appeared to enhance spatial patterns but not override them.

Effect of solar ultra-violet radiation on the kelp Ecklonia radiata

During spring and summer, 1982–1986, experiments were carried out near Marmion Reef, Western Australia. In summer, nearly 30% of the surface solar ultraviolet radiation (280 to 400 nm) penetrates offshore waters to 5 m depth. Experimental removal of the mature Ecklonia radiata kelp canopy in summer results in tissue damage, photopigment destruction, reduced growth, and low survivorship of subcanopy kelp sporophytes. These effects do not occur with canopy removal in winter. Laboratory experiments revealed that the UV component of radiation, rather than intense photosynthetically active radiation, was responsible for the inhibition of growth and photodamage. UV radiation probably affects survival of the settlement stages of E. radiata sporophytes, thus excluding them from otherwise suitable substrata in shallow waters. UV radiation is implicated in the reduction of canopy productivity in summer.

Comments on the First Report

The First Report focuses upon two distinct and major outcomes of the host group adaptation pilot project: cost and social adaptation. In light of the stated objectives, it was predicted that refugees who were assisted by host groups would depend less upon formal cash assistance from governmental sources, especially the Adjustment Assistance Programme (AAF'). Rather, they would be assisted by host groups to obtain goods and services in the community through informal and personal networks available to host-group members. As in the case of private sponsorship, it was expected that donations would supplement and reduce the number of goods which would be purchased in the early stages of settlement. Yet the Report indicates that refugees with host-group experience received about the same (and in certain cases slightly more) assistance from AAP than did host-group refugees. The comparison may not be exact, as the family size of refugees under the host-group programme is larger. Higher AAF' expenditures may thereby be attributable.1 In any event, under the conditions in the pilot programme, no cost savings in governmental assistance are evident.

Demographic structure of the migrant groups of fishermen of Puri coast, India.

SummaryThe demographic structure of the migrant groups of fishermen living in Puri, India, is studied. Data on age, sex, birth place, endogamy, consanguinity, and reproductive histories of 1409 couples and a census of 690 households are utilized. The results suggest the existence of three breeding units within the complex, in different stages of settlement as local populations. Random genetic drift has not yet assumed any significant role in any of these populations. Childhood mortality rates are high; 22% in the Vadabalija of Penticotta, 32% in the Vadabalija of Vadapeta and 35% in the Jalary.In almost all the components of population structure and demographic variables studied, sympatric populations with similar recent migratory histories show greater similarity than the ethnically similar groups.

Urban history in Australasia

New Zealand's national myths have emphasized the rural frontier. The archetypal and most commonly celebrated colonist has been the backblocks settler, the cow cockie, and to some extent the gold miner. New Zealanders have never seen much glamour in their towns. Yet from the very beginning New Zealand has been a mainly urban society. Many towns were founded in the early stages of European settlement, and New Zealand has exhibited in modified form the tendency to ‘metropolitanism’ characteristic of other countries that were settled in the mid-nineteenth century. The urban historian could have a very important role to play in helping New Zealanders to come to terms with, and absorb into their sense of national identity, this major aspect of their national existence.

Essai sur la dynamique des peuplements de lianes ligneuses d’une forêt du Nord-Est du Gabon

The dynamics of two woody liana communities has been studied in two rain forest plots on the M’Passa plateau, North-East Gabon. The forest structure was different in the two areas studied. The first plot (2.4 ha) was set up at ground level on the forest edge, along a track opened ten years earlier. The second plot (3.2 ha) was located within the mature rain forest itself, a few hundred metres away, on uneven ground with a slope leaning towards a small river valley. The pattern of distribution of the woody climbers whose diameter at breast height (DBH) was ≧ 5 cm is described on the two plots. The distribution of these liana communities was always clumped. The density of woody climbers was higher in the forest edge plot than in the mature forest plot (145 ind/ha vs. 114 ind/ha). However, the percentage of older lianas, i.e. those whose DBH was ≧ 10 cm, was higher in the mature forest than at the forest edge (20.6 % vs. 7.8 %). The role of tree falls at the settlement stage of a woody liana community is discussed, and the importance of the supporting trees surrounding the gap is stressed. Woody lianas thrive during the first stages of the forest growth cycle, competing for light with the trees. Later on, woody climber communities age and regress when the forest mosaic matures.

Reproductive seasonality, settlement, and post-settlement mortality of Pocillopora damicornis (Linnaeus), at Lizard Island, Great Barrier Reef

Pocillopora damicornis (Linnaeus) has seasonal gametogenesis and planula release at Lizard Island, Great Barrier Reef, in contrast with several previous reports on the species at other locations. The number of planulae released and gonad development varied considerably among colonies sampled at the same time, but reproductive activity occurred predominantly in winter. P. damicornis planulae settled preferentially on algal-covered substrata, rather than bare coral substrata, but showed subsequent mortality inversely related to this settlement preference. Competition with algae and biological disturbance contribute to spat mortality at different stages of settlement and growth.

Consolidation analysis by the velocity method : Barkin, A K Proc 10th International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15–19 June 1981, V1, P723–726. Publ Rotterdam: A. A. Balkema, 1981

A new method for deriving the coefficient of consolidation from oedometer test results is proposed, based on a velocity time graph. The method requires no construction, and is shown to be unaffected by imperfections in the initial and final stages of settlement. The method is used to examine typical behaviour of several natural soils, including normally consolidated clays, moderately and heavily over consolidated clays, and sensitive clays (a).

The use of housing as a spatio-political measure: the Israeli case

This paper focuses on the use of the provision of public housing in Israel as a political measure, in addition to its benign role of providing shelter. In the early stages of Jewish settlement in the country the Right controlled most towns and cities, while Labour was engaged in building a rural base. As urban growth attracted many of the newly arrived workers, Labour found it necessary to become politically active in the urban sphere. This has been done through the provision of a variety of services, among which was the provision of housing with a view to recruiting their political support. Two strategies were adopted. One was the penetration of existing towns by building public housing estates, the other was the establishment of new urban centres. These strategies have enabled Labour to attain local political hegemony in many cities, but while the provision of public housing proved to be as effective political tool in the short run, it has failed to secure a lasting impact.

Public Poor Relief and the Massachusetts Community, 1620-1715

IN 1624 secretary for the Merchant Adventurers, James Sherley, sent the inhabitants of Plymouth Colony one red heifer begin a stock for the poor. Five years later, preparing for the Winthrop fleet to sail, the Massachusetts Bay Company instructed John Endecott, its resident governor of the settlement at Salem, to raise a general stock for community purposes, including the relief of the poor.1 These actions were the first formal steps taken to provide public poor relief in Massachusetts. Thereafter, settlement and provision for public poor relief advanced hand in hand. With one possible exception, every community in the Plymouth and Massachusetts Bay colonies provided for relief in the initial stages of settlement and subsequently administered relief as a regular town function.2 Public poor relief, it appears, was basic to the Massachusetts community experience. So basic was the association, in fact, that public poor relief

Settlements of turbogenerator foundations in the first power unit of the Kura nuclear power plant

1. The results of full-scale instrument observations made it possible to establish that the active settlement stage of turbogenerator foundations continued for a period of three years after the start of construction. Maximum settlements over the entire period amounted to 18–20 mm in contrast to their design value of 58 mm. 2. After two years of service, the settlements stabilized at a certain level relative to which fluctuations from ±1 to ±1.5 mm occurred to variation in temperature regimes. 3. External factors — the control of construction-assembly work, water table fluctuation, and the vibration of power equipment — did not have a significant effect on the progress of deformations of the turbogenerator foundations.

Change and Continuity in Zionist Territorial Orientations and Politics

components in the Zionist ideology and political praxis that refer to territory, by using some analytical concepts that will be presented and developed. I shall analyze systematically the period beginning with the initial stage of the Jewish settlement of Palestine and ending with the preliminary consequences of the recent peace treaty between Egypt and Israel. The major theoretical question around which the discussion will be focused is the possible causal relationships between the diverse and changing orientations or feelings toward a specific territorial expanse and the political practice (i.e., different degrees and patterns of control or desire for control) related to this space.