Humboldt University of Berlin

About: Humboldt University of Berlin is a education organization based out in Berlin, Germany. It is known for research contribution in the topics: Population & Transplantation. The organization has 33671 authors who have published 61781 publications receiving 1908102 citations. The organization is also known as: Humboldt-Universität zu Berlin & Universitas Humboldtiana Berolinensis.

Middle-range theories of land system change

Abstract: Changes in land systems generate many sustainability challenges Identifying more sustainable land-use alternatives requires solid theoretical foundations on the causes of land-use/cover changes Land system science is a maturing field that has produced a wealth of methodological innovations and empirical observations on land-cover and land-use change, from patterns and processes to causes We take stock of this knowledge by reviewing and synthesizing the theories that explain the causal mechanisms of land-use change, including systemic linkages between distant land-use changes, with a focus on agriculture and forestry processes We first review theories explaining changes in land-use extent, such as agricultural expansion, deforestation, frontier development, and land abandonment, and changes in land-use intensity, such as agricultural intensification and disintensification We then synthesize theories of higher-level land system change processes, focusing on: (i) land-use spillovers, including land sparing and rebound effects with intensification, leakage, indirect land-use change, and land-use displacement, and (ii) land-use transitions, defined as structural non-linear changes in land systems, including forest transitions Theories focusing on the causes of land system changes span theoretically and epistemologically disparate knowledge domains and build from deductive, abductive, and inductive approaches A grand, integrated theory of land system change remains elusive Yet, we show that middle-range theories – defined here as contextual generalizations that describe chains of causal mechanisms explaining a well-bounded range of phenomena, as well as the conditions that trigger, enable, or prevent these causal chains –, provide a path towards generalized knowledge of land systems This knowledge can support progress towards sustainable social-ecological systems

Predicting MOOC Dropout over Weeks Using Machine Learning Methods

Abstract: With high dropout rates as observed in many current larger-scale online courses, mechanisms that are able to predict student dropout become increasingly important. While this problem is partially solved for students that are active in online forums, this is not yet the case for the more general student population. In this paper, we present an approach that works on click-stream data. Among other features, the machine learning algorithm takes the weekly history of student data into account and thus is able to notice changes in student behavior over time. In the later phases of a course (i.e., once such history data is available), this approach is able to predict dropout significantly better than baseline methods.

Bringing an ecological view of change to Landsat‐based remote sensing

Abstract: When characterizing the processes that shape ecosystems, ecologists increasingly use the unique perspective offered by repeat observations of remotely sensed imagery. However, the concept of change embodied in much of the traditional remote-sensing literature was primarily limited to capturing large or extreme changes occurring in natural systems, omitting many more subtle processes of interest to ecologists. Recent technical advances have led to a fundamental shift toward an ecological view of change. Although this conceptual shift began with coarser-scale global imagery, it has now reached users of Landsat imagery, since these datasets have temporal and spatial characteristics appropriate to many ecological questions. We argue that this ecologically relevant perspective of change allows the novel characterization of important dynamic processes, including disturbances, longterm trends, cyclical functions, and feedbacks, and that these improvements are already facilitating our understanding of critical driving forces, such as climate change, ecological interactions, and economic pressures.

Ruminants, climate change and climate policy

Abstract: Greenhouse gas emissions from ruminant meat production are significant. Reductions in global ruminant numbers could make a substantial contribution to climate change mitigation goals and yield important social and environmental co-benefits.

Comparison of quality of life in patients undergoing abdominoperineal extirpation or anterior resection for rectal cancer.

Abstract: ObjectiveTo evaluate the quality of life (QoL) in patients undergoing anterior resection (AR) or abdominoperineal extirpation (APE) for rectal cancer in a sample of patients recruited from a field trial.Summary Background DataAbdominoperineal resection has been reported to put patients at higher ris