The first definitive carcharodontosaurid (Dinosauria: Theropoda) from Asia and the delayed ascent of tyrannosaurids

Little is known about the evolution of large-bodied theropod dinosaurs during the Early to mid Cretaceous in Asia. Prior to this time, Asia was home to an endemic fauna of basal tetanurans, whereas terminal Cretaceous ecosystems were dominated by tyrannosaurids, but the intervening 60 million years left a sparse fossil record. Here, we redescribe the enigmatic large-bodied Chilantaisaurus maortuensis from the Turonian of Inner Mongolia, China. We refer this species to a new genus, Shaochilong, and analyze its systematic affinities. Although Shaochilong has previously been allied with several disparate theropod groups (Megalosauridae, Allosauridae, Tyrannosauroidea, Maniraptora), we find strong support for a derived carcharodontosaurid placement. As such, Shaochilong is the first unequivocal Asian member of Carcharodontosauridae, which was once thought to be restricted to Gondwana. The discovery of an Asian carcharodontosaurid indicates that this clade was cosmopolitan in the Early to mid Cretaceous and that Asian large-bodied theropod faunas were no longer endemic at this time. It may also suggest that the ascent of tyrannosaurids into the large-bodied dinosaurian predator niche was a late event that occurred towards the end of the Cretaceous, between the Turonian and the Campanian. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Field-scale monitoring of the long-term impact and sustainability of drainage water reuse on the west side of California's San Joaquin Valley

Diminishing freshwater resources have brought attention to the reuse of degraded water as a water resource rather than a disposal problem. Drainage water from tile-drained, irrigated agricultural land is degraded water that is often in large supply, but the long-term impact and sustainability of its reuse on soil is unknown. Similarly, nothing is known of the ramifications of terminating drainage water reuse. The objective of this study is (i) to monitor the long-term impact on soil chemical properties and thereby the sustainability of drainage water reuse on a marginally productive, saline-sodic, 32.4 ha field located on the west side of California's productive San Joaquin Valley and (ii) to assess spatially what happens to soil when drainage water reuse is terminated. The monitoring and assessment were based on spatial chemical data for soil collected during 10 years of irrigation with drainage water followed by 2 years of no applied irrigation water (only rainfall). Geo-referenced measurements of apparent soil electrical conductivity (EC(a)) were used to direct the soil sampling design to characterize spatial variability of impacted soil properties. Chemical analyses of soil samples were used (i) to characterize the spatial variability of salinity, Na, B, and Mo, which were previously identified as critical to the yield and quality of Bermuda grass (Cynodon dactylon (l.) Pers.) grown for livestock consumption and (ii) to monitor their change during the 12 year study. Soil samples were taken at 0.3 m increments to a depth of 1.2 m at each of 40 sample sites on five occasions: August 1999, April 2002, November 2004, August 2009, and May 2011. Drainage water varying in salinity (1.8-16.3 dS m(-1)), SAR (5.2-52.4), Mo (80-400 μg L(-1)), and B (0.4-15.1 mg L(-1)) was applied from July 2000 to June 2009. Results indicate that salts, Na, Mo, and B were leached from the root zone causing a significant improvement in soil quality from 1999 to 2009. Salinity and SAR returned to original levels or higher in less than two years after termination of irrigation. Boron and Mo showed significant increases. Long-term sustainability of drainage water reuse was supported by the results, but once application of irrigation water was terminated, the field quickly returned to its original saline-sodic condition.     

An assessment of the significant physicochemical interactions involved in pesticide diffusion within a pesticide-sediment-water system

Using the explicit method of finite differences, a one-dimensional numerical model for the diffusion of pesticides through a sorbing porous medium under saturated conditions has been developed to assess the significant physical and chemical properties which influence the diffusion process in an aquatic system. The model quantitatively demonstrates in which area of the aquatic environment a given pesticide will principally reside, as well as providing a means of indicating to what degree various sediment and pesticide chemical and physical properties will influence the migration of the pesticide.     

Being there: the acceptance and marginalization of part‐time professional employees

Part‐time professional employees represent an increasingly important social category that challenges traditional assumptions about the relationships between space, time, and professional work. In this article, we examine both the historical emergence of part‐time professional work and the dynamics of its integration into contemporary organizations. Professional employment has historically been associated with being continuously available to one's organization, and contemporary professional jobs often bear the burden of that legacy as they are typically structured in ways that assume full‐time (and greater) commitments of time to the organization. Because part‐time status directly confronts that tradition, professionals wishing to work part‐time may face potentially resistant work cultures. The heterogeneity of contemporary work cultures and tasks, however, presents a wide variety of levels and forms of resistance to part‐time professionals. In this paper, we develop a theoretical model that identifies characteristics of local work contexts that lead to the acceptance or marginalization of part‐time professionals. Specifically, we focus on the relationship between a work culture's dominant interaction rituals and their effects on co‐workers' and managers' reactions to part‐time professionals. We then go on to examine the likely responses of part‐time professionals to marginalization, based on their access to organizational resources and their motivation to engage in strategies that challenge the status quo. Copyright © 2003 John Wiley & Sons, Ltd.     

Advancing the Integration of History and Ecology for Conservation

Abstract: The important role of humans in the development of current ecosystems was recognized decades ago; however, the integration of history and ecology in order to inform conservation has been difficult. We identified four issues that hinder historical ecological research and considered possible solutions. First, differences in concepts and methods between the fields of ecology and history are thought to be large. However, most differences stem from miscommunication between ecologists and historians and are less substantial than is usually assumed. Cooperation can be achieved by focusing on the features ecology and history have in common and through understanding and acceptance of differing points of view. Second, historical ecological research is often hampered by differences in spatial and temporal scales between ecology and history. We argue that historical ecological research can only be conducted at extents for which sources in both disciplines have comparable resolutions. Researchers must begin by clearly defining the relevant scales for the given purpose. Third, periods for which quantitative historical sources are not easily accessible (before AD 1800) have been neglected in historical ecological research. Because data from periods before 1800 are as relevant to the current state of ecosystems as more recent data, we suggest that historical ecologists actively seek out data from before 1800 and apply analytic methods commonly used in ecology to these data. Fourth, humans are not usually considered an intrinsic ecological factor in current ecological research. In our view, human societies should be acknowledged as integral parts of ecosystems and societal processes should be recognized as driving forces of ecosystem change.