Transforming growth factor- directly induces p53-up-regulated modulator of apoptosis (PUMA) during the rapid induction of apoptosis in myc-driven B-cell lymphomas

Background: TGF-β induces apoptosis in Burkitt's lymphoma cells. Results: PUMA is a direct target gene of TGF-β signaling and is required for rapid apoptosis. Conclusion: TGF-β-mediated direct induction of PUMA contributes to apoptosis in human and murine c-Myc-driven lymphomas. Significance: These studies link TGF-β signaling and transcriptional activation of PUMA, two factors with critical roles in regulating B-cell survival

A palaeoenvironmental history of the southern Bekaa Valley and the Lebanon Mountains, Lebanon during the last glacial period (~ 112-35 ka BP)

The remnant montane forests of southern Lebanon provide habitat to a rich diversity of endemic, rare and threatened plant and animal species. Prior to the intensification of human activity during the mid-Holocene period these forests covered most of the Lebanon and Anti-Lebanon Mountain ranges. What is not known is how the dynamics of these forests changed in response to major shifts in climate. The aim of this DPhil thesis was to document changes in vegetation composition in southern Lebanon during the last glacial period (~112 to 35 ka BP). To achieve this aim, a palynological study was conducted on a sedimentary sequence recovered from Aammiq Wetland located in the Bekaa Valley, Lebanon. Fossil pollen was analysed to reconstruct variability in vegetation composition and abundance. Energy dispersive spectroscopy, magnetic susceptibility and loss-on-ignition were used to reconstruct the geomorphological and hydrological processes acting within the wetland and its watershed. Macro and microcharcoal were analysed to reconstruct local and regional fire histories respectively. A chronology was established for this sequence using a combination of radiocarbon and optically stimulated luminescence dating (OSL) techniques. The results indicate significant variability in the composition and abundance of vegetation through the time interval ~ 112 to ~ 35 ka BP closely aligned in time to global and regional climatic events. Changes in the chemical and physical properties of the sediments indicate significant variability in landscape erosion processes and hydrological conditions in the watershed and within the wetland over the similar interval in time. Peaks in local and regional fire activity were concurrent with periods of precession minima and Dansgaard-Oeschger warming events and had a significant impact on the composition of vegetation within the Aammiq region. These findings provide the first account of environmental change in the southern Bekaa Valley and adjacent slopes of the Lebanon Mountains during the last glacial period.</p

Social-ecological systems in the Anthropocene : the need for integrating social and biophysical records at regional scales

Understanding social-ecological system dynamics is a major research priority for sustainable management of landscapes, ecosystems and resources. But the lack of multi-decadal records represents an important gap in information that hinders the development of the research agenda. Without improved information on the long-term and complex interactions between causal factors and responses, it will be difficult to answer key questions about trends, rates of change, tipping points, safe operating spaces and pre-impact conditions. Where available long-term monitored records are too short or lacking, palaeoenvironmental sciences may provide continuous multi-decadal records for an array of ecosystem states, processes and services. Combining these records with conventional sources of historical information from instrumental monitoring records, official statistics and enumerations, remote sensing, archival documents,cartography and archaeology produces an evolutionary framework for reconstructing integrated regional histories. We demonstrate the integrated approach with published case studies from Australia, China, Europe and North America.Peer reviewe

An intensive tree-ring experience: Connecting education and research during the 25th European Dendroecological Fieldweek (Asturias, Spain).

The European Dendroecologial Fieldweek (EDF) provides an intensive learning experience in tree-ring research that challenges any participant to explore new multidisciplinary dendro-sciences approaches within the context of field and laboratory settings. Here we present the 25th EDF, held in Asturias, NW Spain, in summer 2014. The course, with 33 participants and 10 instructors from 18 countries included advanced training in dendrochronology skills, an overview of tree-ring broad fields and methodological basics to deal with specific research questions as well as applied advanced micro-projects in dendroarchaeology (DAR), dendroclimatology (DCL), dendrogeomorphology (DGM), forest dynamic (FD) and plant anatomy (PA). The results demonstrated the potential of tree-ring research in the Asturias region. The DAR group researched archaeological samples from different contexts (Oviedo cathedral choir stalls, Segovia cathedral roof timbers, Ribadeo shipwreck ship timbers and Bronze Age site charcoal) and explored the supply of wood in different periods. The DCL group established that the Quercus robur and Castanea sativa ring-width measurements show weak climate-growth correlations, where for many trees this is likely caused by management. The strength of the climatic signal could be enhanced using undisturbed settings. The DGM group found that Corylus avellana and Salix spp. are challenging species for dendrogeomorphological studies. Debris-flow events were detected by the presence of tension wood, growth reduction and scars, and their incidences were also supported by local meteorological data. The FD group found that tree growth decreases with increasing competition, a pattern more pronounced in C. sativa than in Pinus sylvestris forest plantations. The results indicate that wood production could be increased by applying thinning treatments on C. sativa. The PA group showed that xylem conduits and phloem area are organized according to the common needs for water supply to leaves and obtain photosynthetic products, regardless site growing conditions for P. sylvestris and Tusilago farfara. In conclusion, this EDF has been a model for interdisciplinary research and international collaboration that has demonstrated that high-quality research and education can be conducted within one week. The EDFs provide an important service to the dendrochronological community and demonstrate the usefulness of this educational-scientific and multi-cultural experience