Patch-level spatial layout for classification and weakly supervised localization

International audienceWe propose a discriminative patch-level spatial layout model suitable for training with weak supervision. We start from a block-sparse model of patch appearance based on the normalized Fisher vector representation. The appearance model is responsible for i) selecting a discriminative subset of visual words, and ii) identifying distinctive patches assigned to the selected subset. These patches are further filtered by a sparse spatial model operating on a novel representation of pairwise patch layout. We have evaluated the proposed pipeline in image classification and weakly supervised localization experiments on a public traffic sign dataset. The results show significant advantage of the proposed spatial model over state of the art appearance models

Opportunities to Learn Mathematics Pedagogy and Connect Classroom Learning to Practice: A Study of Future Teachers in the United States and Singapore

In this study, we conducted secondary analyses using the TEDS-M database to explore future mathematics specialists teachers’ opportunities to learn (OTL) how to teach mathematics. We applied latent class analysis techniques to differentiate among groups of prospective mathematics specialists with potentially different OTL mathematics pedagogy within the United States and Singapore. Within the United States, three subgroups were identified: (a) Comprehensive OTL, (b) Limited OTL, and (c) OTL Mathematics Pedagogy. Within Singapore, four subgroups were identified: (a) Comprehensive OTL, (b) Limited Opportunities to Connect Classroom Learning with Practice, (c) OTL Mathematics Pedagogy, and (d) Basic OTL. Understanding the opportunities different prospective teachers had to learn from and their experiences with different components of instructional practice in university and practicum settings has implications for teacher preparation programs

Technology-supported learning innovation in cultural contexts

Many reform initiatives adopt a reductionist, proceduralized approach to cultural change, assuming that deep changes can be realized by introducing new classroom activities, textbooks, and technological tools. This article elaborates a complex system perspective of learning culture: A learning culture as a complex system involves macro-level properties (e.g., epistemological beliefs, social values, power structures) and micro-level features (e.g., technology, classroom activities). Deep changes in macro-level properties cannot be reduced to any component. This complex system perspective is applied to examining technology-supported educational change in East Asia and analyzing how teachers sustain the knowledge building innovation in different contexts. Working with the macro-micro dynamics in a learning culture requires a principle-based approach to learning innovation that specifies macro-level changes using principle-based instead of procedure-based terms and engages teachers’ deep reflection and creative engagement at both the macro- and the micro-level

Homeostatic regulation of the endoneurial microenvironment during development, aging and in response to trauma, disease and toxic insult

The endoneurial microenvironment, delimited by the endothelium of endoneurial vessels and a multi-layered ensheathing perineurium, is a specialized milieu intérieur within which axons, associated Schwann cells and other resident cells of peripheral nerves function. The endothelium and perineurium restricts as well as regulates exchange of material between the endoneurial microenvironment and the surrounding extracellular space and thus is more appropriately described as a blood–nerve interface (BNI) rather than a blood–nerve barrier (BNB). Input to and output from the endoneurial microenvironment occurs via blood–nerve exchange and convective endoneurial fluid flow driven by a proximo-distal hydrostatic pressure gradient. The independent regulation of the endothelial and perineurial components of the BNI during development, aging and in response to trauma is consistent with homeostatic regulation of the endoneurial microenvironment. Pathophysiological alterations of the endoneurium in experimental allergic neuritis (EAN), and diabetic and lead neuropathy are considered to be perturbations of endoneurial homeostasis. The interactions of Schwann cells, axons, macrophages, and mast cells via cell–cell and cell–matrix signaling regulate the permeability of this interface. A greater knowledge of the dynamic nature of tight junctions and the factors that induce and/or modulate these key elements of the BNI will increase our understanding of peripheral nerve disorders as well as stimulate the development of therapeutic strategies to treat these disorders

Species-Specific Therapy of Acute Lymphoid Leukemia

Forty years ago, Farber and associates described temporary remissions of acute leukemia in children produced by folic acid antagonists [13]. This ignited the hope that this most frequent and always fatal childhood cancer might be curable by drugs. Twenty years ago, Aur and as-sociates completed accession of patients to total therapy study V, the first treat-ment protocol to result in 50 % cure of acute lymphoid leukemia (ALL) [3]. Their results stand 20 years later (Fig. 1), and have been reproduced throughout the world in many thousands of children [6]. More important, recent national vital statistics of the United States and the United Kingdom indicate a 50 % reduc-tion in childhood leukemia mortality [4, 29]. Further, the cured children generally enjoy a normal life-style without need for medication. In the past 20 years, efforts have been directed at improving the cure rate of ALL while simplifying curative treat-ment, reducing its side effects, and im-proving its availability and accessibility. In a Stohlman Lecture at Wilsede 10 years ago the following statement was made [32]:- The most significant opportunity for improving the treatment of acute lymphoid leukemia in the past five years has been its biological and clini-cal classification by immunological cell surface markers. This allows spe-cies identification of the leukemia cells, the first step toward developing specific cytocidal or cytostatic therapy