Extending resection and preserving function: modern concepts of glioma surgery

Recent studies have demonstrated that the improved prognosis derived from resection of gliomas largely depends on the extent and quality of the resection, making maximum but safe resection the ultimate goal. Simultaneously, technical innovations and refined neurosurgical methods have rapidly improved efficacy and safety. Because gliomas derive from intrinsic brain cells, they often cannot be visually distinguished from the surrounding brain tissue during surgery. In order to appreciate the full extent of their solid compartment, various technologies have recently been introduced. However, radical resection of infiltrative glioma puts neurological function at risk, with potential detrimental consequences for patients' survival and quality of life. The allocation of various neurological functions within the brain varies in each patient and may undergo additional changes in the presence of a tumour (brain plasticity), making intra-operative localisation of eloquent areas mandatory for preservation of essential brain functions. Combining methods that visually distinguish tumour tissue and detect tissues responsible for critical functions now enables resection of tumours in brain regions that were previously considered off-limits, and benefits patients by enabling a more radical resection, while simultaneously lowering the risk of neurological deficits. Here we review recent and expected developments in microsurgery for glioma and their respective benefits.

The "Profiles" document: a modern revision of the objectives of undergraduate medical studies in Switzerland

The Joint Commission of the Swiss Medical Schools (SMIFK/CIMS) decided in 2000 to establish a Swiss Catalogue of Learning Objectives (SCLO) for undergraduate medical training, which was adapted from a similar Dutch blueprint. A second version of the SCLO was developed and launched in 2008. The catalogue is a prerequisite for the accreditation of the curricula of the six Swiss medical faculties and defines the contents of the Federal Licensing Examination (FLE). Given the evolution of the field of medicine and of medical education, the SMIFK/CIMS has decided to embark on a total revision of the SCLO. This article presents the proposed structure and content of Profiles, a new document which, in the future, will direct the format of undergraduate studies and of the FLE. Profiles stands for the Principal Relevant Objectives for Integrative Learning and Education in Switzerland. It is currently being developed by a group of experts from the six Swiss faculties as well as representatives of other institutions involved in these developments. The foundations of Profiles are grounded in the evolution of medical practice and of public health and are based on up-to-date teaching concepts, such as EPAs (entrustable professional activities). An introduction will cover the concepts and a tutorial will be displayed. Three main chapters will provide a description of the seven 2015 CanMEDS roles, a list of core EPAs and a series of ≈250 situations embracing the most frequent and current conditions affecting health. As Profiles is still a work in progress, it is hoped that this paper will attract the interest of all individuals involved in the training of medical students.

Statistical evaluation of alternative models of human evolution

An appropriate model of recent human evolution is not only important to understand our own history, but it is necessary to disentangle the effects of demography and selection on genome diversity. Although most genetic data support the view that our species originated recently in Africa, it is still unclear if it completely replaced former members of the Homo genus, or if some interbreeding occurred during its range expansion. Several scenarios of modern human evolution have been proposed on the basis of molecular and paleontological data, but their likelihood has never been statistically assessed. Using DNA data from 50 nuclear loci sequenced in African, Asian and Native American samples, we show here by extensive simulations that a simple African replacement model with exponential growth has a higher probability (78%) as compared with alternative multiregional evolution or assimilation scenarios. A Bayesian analysis of the data under this best supported model points to an origin of our species approximately 141 thousand years ago (Kya), an exit out-of-Africa approximately 51 Kya, and a recent colonization of the Americas approximately 10.5 Kya. We also find that the African replacement model explains not only the shallow ancestry of mtDNA or Y-chromosomes but also the occurrence of deep lineages at some autosomal loci, which has been formerly interpreted as a sign of interbreeding with Homo erectus.

Water versus ice: The competing roles of modern climate and Pleistocene glacial erosion in the Central Alps of Switzerland

Recent studies have identified relationships between landscape form, erosion and climate in regions of landscape rejuvenation, associated with increased denudation. Most of these landscapes are located in non-glaciated mountain ranges and are characterized by transient geomorphic features. The landscapes of the Swiss Alps are likewise in a transient geomorphic state as seen by multiple knickzones. In this mountain belt, the transient state has been related to erosional effects during the Late Glacial Maximum (LGM). Here, we focus on the catchment scale and categorize hillslopes based on erosional mechanisms, landscape form and landcover. We then explore relationships of these variables to precipitation and extent of LGM glaciers to disentangle modern versus palaeo controls on the modern shape of the Alpine landscape. We find that in grasslands, the downslope flux of material mainly involves unconsolidated material through hillslope creep, testifying a transport-limited erosional regime. Alternatively, strength-limited hillslopes, where erosion is driven by bedrock failure, are covered by forests and/or expose bedrock, and they display oversteepened hillslopes and channels. There, hillslope gradients and relief are more closely correlated with LGM ice occurrence than with precipitation or the erodibility of the underlying bedrock. We relate the spatial occurrence of the transport- and strength-limited process domains to the erosive effects of LGM glaciers. In particular, strength-limited, rock dominated basins are situated above the equilibrium line altitude (ELA) of the LGM, reflecting the ability of glaciers to scour the landscape beyond threshold slope conditions. In contrast, transport-limited, soil-mantled landscapes are common below the ELA. Hillslopes covered by forests occupy the elevations around the ELA and are constrained by the tree line. We conclude that the current erosional forces at work in the Central Alps are still responding to LGM glaciation, and that the modern climate has not yet impacted on the modern landscape.

The past ecology of Abies alba provides new perspectives on future responses of silver fir forests to global warming

Paleoecology can provide valuable insights into the ecology of species that complement observation and experiment-based assessments of climate impact dynamics. New paleoecological records (e.g., pollen, macrofossils) from the Italian Peninsula suggest a much wider climatic niche of the important European tree species Abies alba (silver fir) than observed in its present spatial range. To explore this discrepancy between current and past distribution of the species, we analyzed climatic data (temperature, precipitation, frost, humidity, sunshine) and vegetation-independent paleoclimatic reconstructions (e.g., lake levels, chironomids) and use global coupled carbon-cycle climate (NCAR CSM1.4) and dynamic vegetation (LandClim) modeling. The combined evidence suggests that during the mid-Holocene (6000 years ago), prior to humanization of vegetation, A. alba formed forests under conditions that exceeded the modern (1961-1990) upper temperature limit of the species by 5-7°C (July means). Annual precipitation during this natural period was comparable to today (>700-800 mm), with drier summers and wetter winters. In the meso-Mediterranean to sub-Mediterranean forests A. alba co-occurred with thermophilous taxa such as Quercus ilex, Q. pubescens, Olea europaea, Phillyrea, Arbutus, Cistus, Tilia, Ulmus, Acer, Hedera helix, Ilex aquifolium, Taxus, and Vitis. Results from the last interglacial (ca. 130 000-115 000 BP), when human impact was negligible, corroborate the Holocene evidence. Thermophilous Mediterranean A. alba stands became extinct during the last 5000 years when land-use pressure and specifically excessive anthropogenic fire and browsing disturbance increased. Our results imply that the ecology of this key European tree species is not yet well understood. On the basis of the reconstructed realized climatic niche of the species, we anticipate that the future geographic range of A. alba may not contract regardless of migration success, even if climate should become significantly warmer than today with summer temperatures increasing by up to 5-7°C, as long as precipitation does not fall below 700-800 mm/yr, and anthropogenic disturbance (e.g., fire, browsing) does not become excessive. Our finding contradicts recent studies that projected range contractions under global-warming scenarios, but did not factor how millennia of human impacts reduced the realized climatic niche of A. alba.

Consumption and food production in crisis time: Swiss consumption co-operations as farmers at the End of World War I

During the last two years of World War I food supply in Switzerland declined and caused shortcomings in consume, leading to social distress and conflict. Mainly two important factors caused these problems: First, Switzerland was highly dependent on food imports and during the war traditional supply lines faded. Second, weather extremes in the years 1916–1917 caused crop failure all over Europe and North America, which intensified the decline of food trade between the nations. In 1918 a conflict between classic urban consumers, such as workers, and famers erupted due to the food shortcomings and led to a lasting discord between urban and agrarian regions in Switzerland. But there was not only disharmony and conflict between the urban and agrarian regions. As a matter of fact several agents (urban and agrarian) interested in presenting adequate coping strategies to overcome the food shortages developed ideas of alternative ways of food production and supply since 1917. The aim of the paper is to outline these strategies that were undertaken to create a new era of food production that was not solely dependent on the agrarian sector or the import-trade. Actual growing of vegetables in estate areas is an important, but just one, factor of establishing a new system of food production, distribution and consume. The market-leading grocery stores in Switzerland nowadays (Coop and Migros) started their business during that time as co-operatives establishing new forms of distribution and food-production. So the interest of the paper is not only in actual «urban farming», but it wants to share some light on how swiss urban and agrarian spheres overlapped their functions in order to create a modern system of agro food-chains at the beginning of the interwar period.

Prehistoric genomes reveal the genetic foundation and cost of horse domestication

The domestication of the horse revolutionized warfare, trade, and the exchange of people and ideas. This at least 5,500-y-long process, which ultimately transformed wild horses into the hundreds of breeds living today, is difficult to reconstruct from archeological data and modern genetics alone. We therefore sequenced two complete horse genomes, predating domestication by thousands of years, to characterize the genetic footprint of domestication. These ancient genomes reveal predomestic population structure and a significant fraction of genetic variation shared with the domestic breeds but absent from Przewalski’s horses. We find positive selection on genes involved in various aspects of locomotion, physiology, and cognition. Finally, we show that modern horse genomes contain an excess of deleterious mutations, likely representing the genetic cost of domestication.

Refractions of Canada in European Literature and Culture

Ever since the first exploratory expeditions in the early modern period, North America has epitomized to Europeans a promise and the hope for the fulfilment of great expectations, be it of more freedom, greater wealth, social liberation or religious tolerance. While numerous features in this dialogic intercontinental relationship will hold true for North America in its entirety, the vast northern territories which we know as Canada today began to emerge early on as a specific iconic location in European mind-maps, and they definitely acquired a distinctive profile after the formation of the USA. As a rich source of cultural exchange and an important partner in political and economic cooperation Canada has come to occupy an important position in the cultural discourses of many European nations. It is these refractions and images of Canada which this volume thoroughly explores in European literature and culture. The contributions include literature, philosophy, language, life-writing and the concept of 'Heimat' (homeland) as well as the cultural impact of the World Wars. While there is an emphasis on literary texts, other fields of cultural representation are also included.