New records of the hypercalcified sponge Plectroninia (Calcarea,Minchinellidae) in the Recent deep ocean

Vacelet, J., James, B. 1, & Zibrowius, H., November 2017. New records of the hypercalcified sponge Plectroninia (Calcarea, Minchinellidae) in the Recent deep ocean. Alcheringa 42, 312–319. ISSN 0311-5518

Numerous small specimens of hypercalcified sponges of the genus Plectroninia (Jurassic to Recent) are recorded from deep water in the Atlantic, Indian and Pacific oceans, where they are attached to diverse hard substrata, mostly scleractinian skeletons. Being represented as skeletons of linked calcareous tetractines with an incomplete free spicule complement, the specimens could not be identified at the species level. These observations show that Plectroninia spp. have a wide distribution in the bathyal zone of the Recent World Ocean, where they may be the most common calcareous sponges.

Jean Vacelet* [jean.vacelet@imbe.fr], Benjamin James [ben.james672@gmail.com], Helmut Zibrowius [helmut.zibrowius@gmail.com] UMR 7263 IMBE, Institut Méditerranéen de Biodiversité et d’Écologie Marine et Continentale, CNRS, IRD, Aix Marseille Université, Avignon Université, Station Marine d’Endoume, Rue de la Batterie des Lions, 13007 Marseille, France.     

From Promising Settler to Undesirable Immigrant: The Deportation of British-born Migrants from Mental Hospitals in Interwar Australia and South Africa

This article examines the process by which British-born migrants to Australia and South Africa were deported from mental hospitals in the 1920s and 1930s. It shows how men and women who arrived as permanent settlers could be re-classified as immigrants subject to expulsion. Debates over who was responsible for those who through mental illness or alcoholism were deemed ‘undesirable’ were conducted at the levels of both high diplomacy and petty bureaucracy. Tracing the history of deportation as a means of social engineering within the empire, this article highlights the tension between the transnational ideology of white supremacy and its expression in national terms. Using the case files of those deported from two settler colonial mental hospitals, Callan Park in Sydney and Valkenberg in Cape Town, as well as official deportation paperwork, it also traces how such diplomatic decisions were refracted through the process of attempted implementation. These files show firsthand both the social history of deportation and the mechanisms through which the settler colonial state aimed to shape its population by excluding not only those perceived to be racially other, but also those judged to be racially unfit. The process of determining domicile and of deportation itself reveals much about the frequently precarious circumstances and life histories of these migrants and their often far-flung networks, as well as the ways in which migrants and their families were able to negotiate the regulatory mechanisms of both the state and the asylum.     

Perspectives: On Political Science: Annual Index Volume 30, 2001

Abstract

Although Tocqueville called Jefferson “the greatest democrat, who has yet issued from within the American democracy,” a close reading of their works suggests that Tocqueville’s assessment of Jefferson was far more mixed than first appears. In the first section, I take up Jefferson’s understanding of the principles of the Declaration of Independence and offer arguments for why Tocqueville chose not to cite the Declaration in Democracy in America. Using those writings of Jefferson available to Tocqueville in French translation, I show that Tocqueville saw in Jefferson’s own understanding of those principles certain dangerous tendencies of the democratic mind. Yet there is one principle on which both agree: the natural right to political liberty and association. Section two compares their contrasting views of republican constitutionalism, taking into account Jefferson’s evolving views of republicanism as well as Tocqueville’s analysis of both the American constitution and his contributions to the committee that framed the French constitution in 1848. The concluding section analyzes their differing assessments of philosophical materialism and religion in preserving the political liberty both sought.     

Agroforestry on an Active Volcanic Small Island in Indonesia: Prospering with Adversity

This paper draws on the literature on agroforestry, disaster risk reduction, and livelihoods of people on small islands as it applies to a community prospering in conditions of adversity in Kinali village on Siau Island, Indonesia. Siau Island produces between one‐third and one‐half of all nutmeg and mace exported from Indonesia. The Kinali community has adopted strategies that enable it to prosper in spite of the risks of living on a small island with an active volcano. The paper charts the sociocultural dynamics of the village and examines how local coping mechanisms based on an agroforestry economy have assisted villagers in dealing with the multiple hazards and constraints arising from the biophysical characteristics of their island. The paper thus contributes to more informed responses to managing volcanic risk.     

Modeling of hydrogen production by serpentinization in ultramafic‐hosted hydrothermal systems: application to the Rainbow field

The production of hydrogen by serpentinization in ultramafic‐hosted hydrothermal systems is simulated by coupling thermodynamic and dynamic modeling in the framework of a thermo‐hydraulic single‐pass model where a high‐temperature hydrothermal fluid moves preferentially through a main canal of high permeability. The alteration of ultramafic rocks is modeled with a first‐order kinetic formulation, wherein the serpentinization rate coefficient, K_r, takes the form: K_r = A exp(?α(T ? T₀)²). In this formulation, α determines the temperature range of the reaction and T₀ is the temperature at which the serpentinization rate reaches its maximum. This model is applied to the Rainbow hydrothermal system, which is situated on the Mid‐Atlantic Ridge, and characterized by a high temperature, a high mass flux, and a very high hydrogen concentration. The results show that a first‐order kinetic law gives a useful representation of the kinetics of serpentinization. The estimated value for the parameter A in the temperature‐dependent formulation of the serpentinization rate coefficient lies in the range (1–5) × 10^?11 s^?1. This effective parameter is several orders of magnitude lower than the values obtained from small grain‐size experiments, but in agreement with other published modeling studies of natural systems. Numerical simulations show that the venting site is able to produce the observed high concentration of hydrogen during the whole continuous lifetime of the Rainbow site.     

ART‐P‐MAP Neural Networks Modeling of Land‐Use Change: Accounting for Spatial Heterogeneity and Uncertainty

Spatial land‐use models over large geographic areas and at fine spatial resolutions face the challenges of spatial heterogeneity, model predictability, data quality, and of the ensuing uncertainty. We propose an improved neural network model, ART‐Probability‐Map (ART‐P‐MAP), tailored to address these issues in the context of spatial modeling of land‐use change. First, it adaptively forms its own network structure to account for spatial heterogeneity. Second, it explicitly infers posterior probabilities of land conversion that facilitates the quantification of prediction uncertainty. Extensive calibration under various test settings is conducted on the proposed model to optimize its utility in seeking useful information within a spatially heterogeneous environment. The calibration strategy involves building a bagging ensemble for training and stratified sampling with varying category proportions for experimentation. Through a temporal validation approach, we examine models’ performance within a systematic assessment framework consisting of global metrics and cell‐level uncertainty measurement. Compared with two baselines, ART‐P‐MAP achieves consistently good and stable performance across experiments and exhibits superior capability to handle the spatial heterogeneity and uncertainty involved in the land‐use change problem. Finally, we conclude that, as a general probabilistic regression model, ART‐P‐MAP is applicable to a broad range of land‐use change modeling approaches, which deserves future research.     

The Holocene fluvial history of the Tremithos river (south central Cyprus) and its linkage to archaeological records

This study aims to reconstruct the Holocene fluvial history of the Tremithos river, south central Cyprus and examine linkages to regional and local archaeological records. Three stratigraphic profiles (Sp1, Sp2 and Sp3) located in the lower valley have been investigated using sedimentology and magnetic parameters. The ¹⁴C dating of 10 samples reveals mid-Holocene ages for Sp1 and Sp2, while the upper most part of Sp3 can be attributed to the early to mid-Holocene. Two main phases of vertical accretion have been recognised: the first, recorded in the lower most part of Sp3, could not be dated but might relate to the late Glacial period. It is not associated with any archaeological artefacts. The second, recorded in all profiles, dating from ca. 5000 to ca. cal 2800 BC, spans the Late Neolithic Sotira (cal 4800/4000 BC) and Late Chalcolithic (cal 2900–2500 BC) cultures. The sediments of Sp1 and Sp2 are up to 8–10 m thick and mainly composed of fine material. However, an intercalated phase of coarse sediment has been identified at the beginning of the third millennium BC, indicating a sudden change in river dynamics, potentially associated with the 5.2 ka rapid climate change regional event. Typical mid-Chalcolithic (ca. cal 3300–3050 BC) ceramics found in a palaeosol in Sp2 indicate for the first time human occupation of the Tremithos river terraces. Two other palaeosols have also been recognised in Sp3 and radiocarbon dated to ca. cal 5600–4100 BC and ca. cal 2900–2600 BC, respectively. These results make it possible to propose a palaeogeographic reconstruction of the Holocene evolution in the Tremithos valley and to make a preliminary assessment of the relative roles of tectonics, climate and anthropogenic forcing.