Late Quaternary paleosols and their paleoenvironmental significance along the Andean piedmont, Eastern Bolivia

The Andean piedmont of eastern Bolivia is situated at the southern margin of Amazonia characterized by an overall humid climate regime with a marked contrast between the rainy and dry seasons. The nearby Subandean foothills deliver abundant sandy sediments to the piedmont, leading to a complex array of sediments and paleosol horizons. Within this setting, the presented study analyzes four profiles of paleosol-sediment-sequences along incised ephemeral streams near Santa Cruz de la Sierra with a focus on past pedogenic variability in the context of the regional late Quaternary geomorphic and environmental evolution. Based on field observations, micromorphological analysis, geochemical and clay mineralogical data five classes of paleosol horizons could be distinguished. The individual paleosol horizons as well as the sediments, in which they developed, were interpreted regarding their paleoenvironmental significance, taking into consideration the various controls on soil formation with particular focus on changes of local environmental conditions through time. Thus, three different pathways of soil formation were established. On the late Quaternary timescale, the results suggest a strong relation between paleoenvironmental conditions (climate, vegetation etc.), soil environment (soil water flow, micro-environment) and the type of paleosol horizons developed in the study area. The formation of “red beds” (Bw horizons) implies very dry soil environments under dominantly dry conditions, which seem to have prevailed in the study area some time before ∼ 18 cal ka BP. Moderately dry but markedly seasonal environmental conditions with a long dry season and strong seasonal contrasts in soil water flow could explain the formation of moderately developed Bwt horizons around ∼ 18 cal ka BP and much of the mid-Holocene. The formation of Bt horizons and/or clay lamellae in relation to intense neoformation of clay and dominant clay illuviation by soil water points to wet conditions similar to today, which have probably prevailed in the study area before ∼ 8 cal ka BP and since ∼ 5 cal ka BP.

High-resolution paleoclimatology of the last millennium: a review of current status and future prospects

This review of late-Holocene palaeoclimatology represents the results from a PAGES/CLIVAR Intersection Panel meeting that took place in June 2006. The review is in three parts: the principal high-resolution proxy disciplines (trees, corals, ice cores and documentary evidence), emphasizing current issues in their use for climate reconstruction; the various approaches that have been adopted to combine multiple climate proxy records to provide estimates of past annual-to-decadal timescale Northern Hemisphere surface temperatures and other climate variables, such as large-scale circulation indices; and the forcing histories used in climate model simulations of the past millennium. We discuss the need to develop a framework through which current and new approaches to interpreting these proxy data may be rigorously assessed using pseudo-proxies derived from climate model runs, where the `answer' is known. The article concludes with a list of recommendations. First, more raw proxy data are required from the diverse disciplines and from more locations, as well as replication, for all proxy sources, of the basic raw measurements to improve absolute dating, and to better distinguish the proxy climate signal from noise. Second, more effort is required to improve the understanding of what individual proxies respond to, supported by more site measurements and process studies. These activities should also be mindful of the correlation structure of instrumental data, indicating which adjacent proxy records ought to be in agreement and which not. Third, large-scale climate reconstructions should be attempted using a wide variety of techniques, emphasizing those for which quantified errors can be estimated at specified timescales. Fourth, a greater use of climate model simulations is needed to guide the choice of reconstruction techniques (the pseudo-proxy concept) and possibly help determine where, given limited resources, future sampling should be concentrated.

Evaluating Integration. Research contributions for a gender sensitive migration policy: Research contributions for a gender sensitive migration policy

The integration of academic and non-academic knowledge is a key concern for researchers who aim at bridging the gap between research and policy. Researchers involved in the sustainability-oriented NCCR North-South programme have made the experience that linking different types of knowledge requires time and effort, and that methodologies are still lacking. One programme component was created at the inception of this transdisciplinary research programme to support exchange between researchers, development practitioners and policymakers. After 8 years of research, the programme is assessing whether research has indeed enabled a continuous communication across and beyond academic boundaries and has effected changes in the public policies of poor countries. In a first review of the data, we selected two case studies explicitly addressing the lives of women. In both cases – one in Pakistan, the other in Nepal – the dialogue between researchers and development practitioners contributed to important policy changes for female migration. In both countries, outmigration has become an increasingly important livelihood strategy. National migration policies are gendered, limiting the international migration of women. In Nepal, women were not allowed to migrate to specific countries such as the Gulf States or Malaysia. This was done in the name of positive discrimination, to protect women from potential exploitation and harassment in domestic work. However, women continued to migrate in many other and often illegal and more risky ways, increasing their vulnerability. In Pakistan, female labour migration was not allowed at all and male migration increased the vulnerability of the families remaining back home. Researchers and development practitioners in Nepal and Pakistan brought women’s shared experience of and exposure to the mechanisms of male domination into the public debate, and addressed the discriminating laws. Now, for the first time in Pakistan, the new draft policy currently under discussion would enable broadly-based female labour migration. What can we learn from the two case studies with regard to ways of relating experience- and research-based knowledge? The paper offers insights into the sequence of interactions between researchers, local people, development practitioners, and policy-makers, which eventually contributed to the formulation of a rights-based migration policy. The reflection aims at exploring the gendered dimension of ways to co-produce and share knowledge for development across boundaries. Above all, it should help researchers to better tighten the links between the spheres of research and policy in future.

On producing and sharing knowledge across boundaries: experiences from the interfaces of an international development research network

The number of large research networks and programmes engaging in knowledge production for development has grown over the past years. One of these programmes devoted to generating knowledge about and for development is National Centre of Competence in Research (NCCR) North–South, a cross-disciplinary, international development research network funded by the Swiss Agency for Development and Cooperation and the Swiss National Science Foundation. Producing relevant knowledge for development is a core goal of the programme and an important motivation for many of the participating researchers. Over the years, the researchers have made use of various spaces for exchange and instruments for co-production of knowledge by academic and non-academic development actors. In this article we explore the characteristics of co-producing and sharing knowledge in interfaces between development research, policy and NCCR North–South practice. We draw on empirical material of the NCCR North–South programme and its specific programme element of the Partnership Actions. Our goal is to make use of the concept of the interface to reflect critically about the pursued strategies and instruments applied in producing and sharing knowledge for development across boundaries.

New means in spinal pedicle hook fixation. A biomechanical evaluation

Pedicle hooks which are used as an anchorage for posterior spinal instrumentation may be subjected to considerable three-dimensional forces. In order to achieve stronger attachment to the implantation site, hooks using screws for additional fixation have been developed. The failure loads and mechanisms of three such devices have been experimentally determined on human thoracic vertebrae: the Universal Spine System (USS) pedicle hook with one screw, a prototype pedicle hook with two screws and the Cotrel-Dubousset (CD) pedicle hook with screw. The USS hooks use 3.2-mm self-tapping fixation screws which pass into the pedicle, whereas the CD hook is stabilised with a 3-mm set screw pressing against the superior part of the facet joint. A clinically established 5-mm pedicle screw was tested for comparison. A matched pair experimental design was implemented to evaluate these implants in constrained (series I) and rotationally unconstrained (series II) posterior pull-out tests. In the constrained tests the pedicle screw was the strongest implant, with an average pull-out force of 1650 N (SD 623 N). The prototype hook was comparable, with an average failure load of 1530 N (SD 414 N). The average pull-out force of the USS hook with one screw was 910 N (SD 243 N), not significantly different to the CD hook's average failure load of 740 N (SD 189 N). The result of the unconstrained tests were similar, with the prototype hook being the strongest device (average 1617 N, SD 652 N). However, in this series the difference in failure load between the USS hook with one screw and the CD hook was significant. Average failure loads of 792 N (SD 184 N) for the USS hook and 464 N (SD 279 N) for the CD hook were measured. A pedicular fracture in the plane of the fixation screw was the most common failure mode for USS hooks.(ABSTRACT TRUNCATED AT 250 WORDS)

Global change revealed by palaeolimnological records from remote lakes: a review

Over recent decades, palaeolimnological records from remote sites have provided convincing evidence for the onset and development of several facets of global environmental change. Remote lakes, defined here as those occurring in high latitude or high altitude regions, have the advantage of not being overprinted by local anthropogenic processes. As such, many of these sites record broad-scale environmental changes, frequently driven by regime shifts in the Earth system. Here, we review a selection of studies from North America and Europe and discuss their broader implications. The history of investigation has evolved synchronously with the scope and awareness of environmental problems. An initial focus on acid deposition switched to metal and other types of pollutants, then climate change and eventually to atmospheric deposition-fertilising effects. However, none of these topics is independent of the other, and all of them affect ecosystem function and biodiversity in profound ways. Currently, remote lake palaeolimnology is developing unique datasets for each region investigated that benchmark current trends with respect to past, purely natural variability in lake systems. Fostering conceptual and methodological bridges with other environmental disciplines will upturn contribution of remote lake palaeolimnology in solving existing and emerging questions in global change science and planetary stewardship.