Trilobites from the Middle Ordovician Stairway Sandstone,Amadeus Basin,central Australia

Abstract

During the Middle Ordovician (Darriwilian) sandstones and siltstones were deposited in the epicontinental Larapintine Sea, which covered large parts of central Australia. The Darriwilian Stairway Sandstone has, for the first time, been sampled stratigraphically for macrofossils to track marine benthic biodiversity in this clastic-dominated shallow-water palaeoenvironment situated along the margin of northeastern Gondwana. The faunas from the Stairway Sandstone are generally of low diversity and dominated by bivalves but include several animal groups, with trilobites representing 25% of the entire shelly fauna. Thirteen trilobite taxa are described from the Stairway Sandstone; the fauna displays a high degree of endemism. One new species, Basilicus (Parabasilicus) brumbyensis sp. nov. is described.     

Explaining Congressional Staff Members’ Decisions to Leave the Hill

The high turnover of congressional staff members can have a negative effect on the functioning of Congress as an institution. Though junior staff turnover is not considered a significant concern, the high turnover of senior staff members is problematic. Using data from a survey of staff members located in the Washington personal offices of House of Representatives members, this article investigates what factors influence the likelihood to leave congressional employment. Specifically, I explore how solidary, purposive, and material work incentives influence staff members’ plans to exit. The results of two different models—one for junior and mid-level staff members and one for executive staff members—indicate that purposive incentives, and material incentives that accrue for future employment opportunities, carry the most weight across both models. Current salary has a significant effect on executive staff members, but not on their lower-level counterparts. Following this analysis, I propose actions that congressional offices might take to retain staff.     

Space-time geography of female live-in child domestic workers in Dhaka,Bangladesh

Live-in child domestic workers in Bangladesh often experience the surveilling power of their employer's gaze as a Foucauldian panopticon, which both disciplines and engages children in forms of self-discipline. I argue that female child domestic workers in particular have a form of ‘thin’ agency whereby they are severely restricted in their abilities to make independent decisions or to act to their own benefit. I ethnographically unpack the concept of thin agency by analyzing material, cultural, spatial and discursive constraints that both employers and female child domestic workers engage in their daily lives.     

Degradation of Archaeological Wood Under Freezing and Thawing Conditions—Effects of Permafrost and Climate Change

The degradation of archaeological wood at freezing and thawing temperatures is studied at the site of Qajaa in West Greenland through a combination of environmental monitoring, measurement of oxygen consumption and microscopy of wood samples. Permanently frozen wood is still very well preserved after 2–4000 years, while wood samples that thaw every summer show attack by soft rot and an average density loss of 0.1 g cm^–3 (corresponding to 25% of the dry mass) over the past 27 years. Future increases in temperature may increase the decay rate significantly (Q₁₀ = 4.2 at 0–10°C) but the effects on site depend on local hydrology.     

MIGRATION,SKILL FORMATION,AND THE WAGE STRUCTURE*

ABSTRACT We analyze the impacts of migration and of labor market integration on the distribution of skills and the wage structure in both the short and the long run. To do so, we develop a framework where workers have heterogeneous skills and where in‐migration expands the range of available skills in the economy. In the short run, this expansion leads to productivity gains, which may more than offset the negative endowment effects of a larger labor supply so that all workers may be better off. In the long run, in‐migration impacts wages further by altering the workers' incentives to acquire skills, thereby affecting the wage structure indirectly by changing the economy's skill composition. Since the short and the long‐run effects of in‐migration on wages may differ, compositional changes may be an important element to take into consideration. A numerical illustration calibrated on U.S. data suggests that the immigration of skilled workers negatively affects the incentives for domestic skill formation, thereby suggesting that endowment effects dominate externalities. We finally extend the model to cope with the simultaneous impacts that migration and skill formation have on the host and the source region, and we show that more migration increases wage disparities and the skill gap across regions.     

Mode‐Locking and Regional Business Cycle Synchronization*

Abstract. Business cycles in different regions of the United States tend to synchronize. This study investigates the reasons behind this synchronization of business cycles and the consequent formation of a national business cycle. Trade between regions may not be strong enough for one region to “drive” business cycle fluctuations in another region. This study suggests that regional business cycles synchronize due to a nonlinear “mode‐locking” process in which weakly coupled oscillating systems (regions) tend to synchronize. There is no definitive test for mode‐lock. However, simulations, correlations, Granger causality tests, tests for nonlinearities, vector autoregressions, and spectral analysis reveal modest econometric support for the regional mode‐locking hypothesis of business cycle synchronization.