VMC++ validation for photon beams in the energy range of 20-1000 keV

In high energy teletherapy, VMC++ is known to be a very accurate and efficient Monte Carlo (MC) code. In principle, the MC method is also a powerful dose calculation tool in other areas in radiation oncology, e.g., brachytherapy or orthovoltage radiotherapy. However, VMC++ is not validated for the low-energy range of such applications. This work aims in the validation of the VMC++ MC code for photon beams in the energy range between 20 and 1000 keV.

Pre-Columbian human occupation patterns in the eastern plains of the Llanos de Moxos, Bolivian Amazonia

Despite an increasing number of publications regarding the Pre-Columbian earthworks of the Llanos de Moxos, there have been no serious attempts to undertake a systematic survey of the archaeological remains of this lowland region in the Bolivian Amazon. Based on the GIS analysis of data gathered in the field and retrieved from satellite images, we discuss the spatial distribution of the Pre-Columbian settlements in a 4500 Km2 area of the Llanos de Moxos to the east of Trinidad, capital of the Beni Department, and their relationship with the geographical settings. Our findings shed new light on the prehistory of the region and bear important implications for our understanding of the impact of Pre-Columbian human occupation.

Femoral morphology and epiphyseal growth plate changes of the hip during maturation: MR assessments in a 1-year follow-up on a cross-sectional asymptomatic cohort in the age range of 9-17 years

The goal of this prospective study was to characterize the morphology and physeal changes of the femoral head during maturation using MRI in a population-based group of asymptomatic volunteers.

[Histiocytic sarcoma in the Swiss population of Bernese mountain dogs: a retrospective study of its genetic predisposition]

A retrospective study to evaluate the genetic predisposition for histiocytic sarcoma in the Swiss population of purebred Bernese mountain dogs identified 51 histologically confirmed cases between 1997 and 2003. Segregation analysis using five major genetic modes was used to evaluate the 51 cases. The general mode yielded the best results suggesting a genetic predisposition for histiocystic sarcoma in this breed. The disease was found in all families analyzed, therefore elimination of the disease through seletive breeding of certain family lines is not possible.

Molecular Determinants Defining the Triggering Range of Prefusion F Complexes of Canine Distemper Virus

The morbillivirus cell entry machinery consists of a fusion (F) protein trimer that refolds to mediate membrane fusion following receptor-induced conformational changes in its binding partner, the tetrameric attachment (H) protein. To identify molecular determinants that control F refolding, we generated F chimeras between measles virus (MeV) and canine distemper virus (CDV). We located a central pocket in the globular head domain of CDV F that regulates the stability of the metastable, prefusion conformational state of the F trimer. Most mutations introduced into this "pocket'" appeared to mediate a destabilizing effect, a phenotype associated with enhanced membrane fusion activity. Strikingly, under specific triggering conditions (i.e., variation of receptor type and H protein origin), some F mutants also exhibited resistance to a potent morbillivirus entry inhibitor, which is known to block F triggering by enhancing the stability of prefusion F trimers. Our data reveal that the molecular nature of the F stimulus and the intrinsic stability of metastable prefusion F both regulate the efficiency of F refolding and escape from small-molecule refolding blockers. IMPORTANCE: With the aim to better characterize the thermodynamic basis of morbillivirus membrane fusion for cell entry and spread, we report here that the activation energy barrier of prefusion F trimers together with the molecular nature of the triggering "stimulus" (attachment protein and receptor types) define a "triggering range," which governs the initiation of the membrane fusion process. A central "pocket" microdomain in the globular F head contributes substantially to the regulation of the conformational stability of the prefusion complexes. The triggering range also defines the mechanism of viral escape from entry inhibitors and describes how the cellular environment can affect membrane fusion efficiency.

Summer temperature in the eastern part of southern South America: its variability in the twentieth century and a teleconnection with Oceania

The 1907–2001 summer-to-summer surface air temperature variability in the eastern part of southern South America (SSA, partly including Patagonia) is analysed. Based on records from instruments located next to the Atlantic Ocean (36°S–55°S), we define indices for the interannual and interdecadal timescales. The main interdecadal mode reflects the late-1970s cold-to-warm climate shift in the region and a warm-to-cold transition during early 1930s. Although it has been in phase with the Pacific Decadal Oscillation (PDO) index since the 1960s, they diverged in the preceding decades. The main interannual variability index exhibits high spectral power at ~3.4 years and is representative of temperature variability in a broad area in the southern half of the continent. Eleven-years running correlation coefficients between this index and December-to-February (DJF) Niño3.4 show significant decadal fluctuations, out-of-phase with the running correlation with a DJF index of the Southern Annular Mode. The main interannual variability index is associated with a barotropic wavetrain-like pattern extending over the South Pacific from Oceania to SSA. During warm (cold) summers in SSA, significant anticyclonic (cyclonic) anomalies tend to predominate over eastern Australia, to the north of the Ross Sea, and to the east of SSA, whereas anomalous cyclonic (anticyclonic) circulation is observed over New Zealand and west of SSA. This teleconnection links warm (cold) SSA anomalies with dry (wet) summers in eastern Australia. The covariability seems to be influenced by the characteristics of tropical forcing; indeed, a disruption has been observed since late 1970s, presumably due to the PDO warm phase.

Local environmental knowledge: a key input for the sustainable development of Andean mountain communities

Local knowledge is crucial to both human development and environmental conservation. This is especially the case in mountain regions, where a combination of remoteness, harsh climatic conditions, rich cultural heritage, and high biological diversity has led to the development of complex local environmental knowledge systems. In the Andes for instance, rural populations mainly rely on their own environmental knowledge to ensure their food security and health. Recent studies conducted within Quechua communities in Peru and Bolivia showed that this knowledge was both persistent and dynamic, and that it responded to socio-economic and environmental changes through cultural resistance and adaptation. As this paper argues, combining local knowledge and so-called scientific knowledge – especially in development projects – can lead to innovative solutions to the socio-environmental challenges facing mountain communities in our globalized world. Based on experiences from the Andes, this paper will provide concrete recommendations to policymakers and practitioners for integrating local knowledge into development and natural resource management initiatives.