An investigation of the relationship between uniaxial compressive strength and degradation for selected rock types

The relationship between uniaxial compressive strength and degradation was investigated for selected rock types, by using regression analyses to determine whether degradation was a useful predictor of compressive strength. In addition, the effects of aggregate particle size, number of hammer blows during the degradation test, engineering index properties, petrographic characteristics, and water saturation on the compressive strength-degradation relationship were evaluated. The results show that strong inverse relationships exist between compressive strength and degradation (measured on a 9.5-4.75-mm size aggregate) for sandstones and igneous/metamorphic rocks, but that no significant relationship exists for limestones/dolomites. The results also indicate a strong positive correlation between degradation and L.A. abrasion loss and can be used to establish a limit of allowable degradation for practical applications. Engineering index properties do not significantly affect the relationship between compressive strength and degradation but petrographic characteristics are important in explaining the strength and degradation behavior of the rocks studied. Water saturation decreases compressive strength and increases degradation to varying degrees.     

Forests in Limbo: Assessing Costa Rica's Forest and Land Reform Policies

In this article, we consider the stalled implementation of two state policies among recipients of land reform in Costa Rica: the transfer of authority over forests on state agrarian reform lands over to the Ministry of the Environment, and the Rural Development Institute’s requirement to issue land title to the recipients of its land reform projects. To date, neither of these policies is even partially implemented, resulting in both forests and marginalized landholders existing in a state of dual tenure limbo. In this article we draw on document analysis, interviews with policymakers, and interviews with recipients of land reform to determine why these policies have not been implemented. In addition, we assess the potential consequences for forest conservation that this situation has produced by mapping the extent and characteristics of forests that occupy this state of uncertainty.     

Temporal and Spatial Variability of Freshwater Plumes in a Semienclosed Estuarine–Bay System

While the physical forcing mechanisms that govern the outflows of major rivers throughout the world are well documented in the literature, comparably less research has been done to examine the mechanisms that govern the contributions of small rivers and streams to coastal ocean systems. These rivers and streams provide a direct means for the transport of anthropogenic and terrigenous materials from watersheds to coastal oceans. This study describes the temporal and spatial variability of freshwater plumes from Kaneohe Stream, Hawaii, USA, after storm events in the Kaneohe Bay watershed. Freshwater plumes were examined using a combination of fixed moorings, synoptic shipboard surveys, and lagrangian surface drifters. Data sets were collected over the course of 19 months from August 2005 to March 2007 with particular attention paid to storms during the boreal winters. Stream discharge and duration were found to exert a primary control on plume persistence in the southern Kaneohe Bay system. Time series data show a strong coherence between wind forcing and surface currents, which, in combination with data derived from shipboard and aerial surveys, indicate that the spatial variability of freshwater plumes is primarily determined by atmospheric forcing.     

Mapping adaptive capacity and smallholder agriculture: applying expert knowledge at the landscape scale

The impacts of climate change exacerbate the myriad challenges faced by smallholder farmers in the Tropics. In many of these same regions, there is a lack of current, consistent, and spatially-explicit data, which severely limits the ability to locate smallholder communities, map their adaptive capacity, and target adaptation measures to these communities. To explore the adaptive capacity of smallholder farmers in three data-poor countries in Central America, we leveraged expert input through in-depth mapping interviews to locate agricultural landscapes, identify smallholder farming systems within them, and characterize different components of farmer adaptive capacity. We also used this input to generate an index of adaptive capacity that allows for comparison across countries and farming systems. Here, we present an overview of the expert method used, followed by an examination of our results, including the intercountry variation in expert knowledge and the characterization of adaptive capacity for both subsistence and smallholder coffee farmers. While this approach does not replace the need to collect regular and consistent data on farming systems (e.g. agricultural census), our study demonstrates a rapid assessment approach for using expert input to fill key data gaps, enable trans-boundary comparisons, and to facilitate the identification of the most vulnerable smallholder communities for adaptation planning in data-poor environments that are typical of tropical regions. One potential benefit from incorporating this approach is that it facilitates the systematic consideration of field-based and regional experience into assessments of adaptive capacity, contributing to the relevance and utility of adaptation plans.     

Managed Temporary Labour Migration of Pacific Islanders to Australia and New Zealand in the Early Twenty-first Century

ABSTRACT

Circular migration was one of several enduring themes in Graeme Hugo’s highly productive research career. Although his specialist field was Asian population movement, during the 2000s he became increasingly interested in labour migration in the Pacific Islands. This paper reviews the development of two managed circular migration schemes targeting Pacific labour that emerged following the UN High-level Dialogue on International Migration and Development in 2006. New Zealand’s Recognised Seasonal Employer (RSE) scheme and Australia’s Seasonal Worker Program (SWP) have attracted international attention as the kind of ‘best practice’ temporary labour migration schemes that Hugo had in mind when he emphasised the positive contributions that circular forms of mobility could make to development in both source and destination countries. The two schemes have transformed mobility between the participating countries and have played a major role in the negotiations over a free-trade agreement between Pacific Forum countries, including Australia and New Zealand. Although the schemes have been in operation for almost 10 years, this paper argues that they are not becoming ‘business as usual’; they embody complex systems of relationships between multiple stakeholders that require ongoing management to ensure that they do not become traps for low-skilled, low-paid ‘permanent’ temporary workers.     

Care and Global Migration in the Nursing Profession: a north Indian perspective

ABSTRACT

Globalisation, supply–demand dynamics, uneven development, enhanced connectivity including the better flow of information, communication and the reduced cost of travel have encouraged the global integration of nursing labour markets. Developed regions of the world have attracted internationally educated nurses (IENs) because of growing healthcare needs. India, along with the Philippines, has become a key supplier of nurses in the global economy. Traditionally the supply of nurses was heavily regionalised in south India, especially Kerala, but of late Punjab, in north India, has played an increasing role in nurse training and migration as the profession has become more respected and more international. This paper uses survey and interview data to detail the recent interest in nursing as a channel for independent female international migration from Punjab, and to examine how migratory ambitions have developed over the last decade in parallel with the changing status of nursing as an internationally respected profession. We identify growing interest in international migration for nursing students and their increased intention to pursue employment opportunities in Australia and New Zealand. This research highlights how nursing and care migration are increasingly structured by international circuits of training and employment, and how such circuits alter migrant and occupational geographies on the ground in sending regions.     

Emerging flux in active regions

We have compared the rates at which flux emerges in active and quiet solar regions within the sunspot belts. The emerging flux regions (EFRs) were identified by the appearance of arch filament structures in H. All EFRs in high-resolution films of active regions made at Big Bear in 1978 were counted. The comparable rate of flux emergence in quiet regions was obtained from SGD data and independently from EFRs detected outside the active region perimeter on the same films. The rate of flux emergence is 10 times higher in active regions than in quiet regions. A sample of all active regions in 31 days of 1983 gave a ratio of 7.5. We discuss possible mechanisms which might funnel new magnetic flux to regions of strong magnetic field.     

The effect of source area and atmospheric transport on mineral aerosol collected over the North Pacific Ocean

Aerosol samples collected on two North Pacific cruises were analyzed for rock-magnetic properties, grain size and <2 μm and 2–20 μm mineralogy. These sedimentological results were compared with isentropic air mass trajectories in order to study the effects of source region and atmospheric transport on the mineral aerosol. The results indicate that there are differences in the aerosol composition and grain size for two broad source regions. Aerosols which originate from west of the Pacific are characterized by abundant, fine-grained aerosol, which has a high coercivity magnetic composition, and is relatively enriched in kaolinite. Aerosols originating from continents to the north and east of the Pacific basin are much less abundant, contain coarse-grained material with a low coercivity magnetic component, and the mineralogy is relatively enriched in plagioclase. Comparison of the mineral aerosol from Asia with atmospheric transport time indicated that the concentration of the mineral aerosol decreases with increasing transport time. The mineral aerosol is compositionally fractionated as it moves away from the continental source region, with a relative decrease in the primary minerals quartz and plagioclase and an increase in the smectite, illite and chlorite concentration with increasing transport time.     

Increased toxicity of benzo(a)pyrene-7,8-dihydrodiol in the presence of polychlorobiphenylols

Benzo(a)pyrene (BaP) and polychlorinated biphenyls (PCBs) often co-exist in contaminated environments. Polychlorobiphenylols (OH-PCBs), formed by CYP-dependent monooxygenation of PCBs, are potent inhibitors of the glucuronidation of hydroxylated BaP metabolites. We hypothesized that OH-PCBs could drive the biotransformation of (-)BaP-7,8-dihydrodiol (BaP-7, 8-D) away from detoxication and towards formation of the reactive metabolite. A mixture of five OH-PCBs with 4-6 Cl atoms was infused into isolated, perfused, biliary intact livers (n=3 fish) removed from 3-methylcholanthrene-induced channel catfish. Controls (n=3) were infused with vehicle. Subsequently, [3H]-BaP-7, 8-D was infused into each liver and bile was collected for 1 h. The livers were taken for analysis of metabolites and DNA adducts. Induction status was confirmed by EROD assay. Bile was analyzed for metabolites. It was found that preinfusion of the mixture of OH-PCBs reduced the extent of glucuronidation of BaP-7, 8-D and increased the formation of DNA adducts 5-fold over controls. GSH conjugates, tetrols and triols were increased in the OH-PCB-infused fish, providing further support for our hypothesis that if the glucuronidation were inhibited, CYP-dependent activation would increase. These studies suggest a mechanism for synergy of toxicity of PAH and PCBs.