Abstract. Much recent research in human activity recognition has focused on the problem of recognizing simple repetitive (walking, running, waving) and punctual actions (sitting up, opening a door, hugging). However, many interesting human activities are characterized by a complex temporal composition of simple actions. Automatic recognition of such complex actions can benefit from a good understanding of the temporal structures. We present in this paper a framework for modeling motion by exploiting the temporal structure of the human activities. In our framework, we represent activities as temporal compositions of motion segments. We train a discriminative model that encodes a temporal decomposition of video sequences, and appearance models for each motion segment. In recognition, a query video is matched to the model according to the learned appearances and motion segment decomposition. Classification is made based on the quality of matching between the motion segment classifiers and the temporal segments in the query sequence. To validate our approach, we introduce a new dataset of complex Olympic Sports activities. We show that our algorithm performs better than other state of the art methods.

Signal transducer and activator of transcription 3 (STAT3) is phosphorylated by various kinases, several of which have been implicated in aberrant fibroblast activation in fibrotic diseases including systemic sclerosis (SSc). Here we show that profibrotic signals converge on STAT3 and that STAT3 may be an important molecular checkpoint for tissue fibrosis. STAT3 signaling is hyperactivated in SSc in a TGFβ-dependent manner. Expression profiling and functional studies in vitro and in vivo demonstrate that STAT3 activation is mediated by the combined action of JAK, SRC, c-ABL, and JNK kinases. STAT3-deficient fibroblasts are less sensitive to the pro-fibrotic effects of TGFβ. Fibroblast-specific knockout of STAT3, or its pharmacological inhibition, ameliorate skin fibrosis in experimental mouse models. STAT3 thus integrates several profibrotic signals and might be a core mediator of fibrosis. Considering that several STAT3 inhibitors are currently tested in clinical trials, STAT3 might be a candidate for molecular targeted therapies of SSc.

Kinesin-3 motor UNC-104/KIF1A is essential for transporting synaptic precursors to synapses. Although the mechanism of cargo binding is well understood, little is known how motor activity is regulated. We mapped functional interaction domains between SYD-2 and UNC-104 by using yeast 2-hybrid and pull-down assays and by using FRET/ fluorescence lifetime imaging microscopy to image the binding of SYD-2 to UNC-104 in living Caenorhabditis elegans. We found that UNC-104 forms SYD-2-dependent axonal clusters (appearing during the transition from L2 to L3 larval stages), which behave in FRAP experiments as dynamic aggregates. High-resolution microscopy reveals that these clusters contain UNC-104 and synaptic precursors (synaptobrevin-1). Analysis of motor motility indicates bi-directional movement of UNC-104, whereas in syd-2 mutants, loss of SYD-2 binding reduces net anterograde movement and velocity (similar after deleting UNC-104's liprin-binding domain), switching to retrograde transport characteristics when no role of SYD-2 on dynein and conventional kinesin UNC-116 motility was found. These data present a kinesin scaffolding protein that controls both motor clustering along axons and motor motility, resulting in reduced cargo transport efficiency upon loss of interaction.motor regulation ͉ synaptic vesicle transport ͉ active zone protein ͉ axonal transport ͉ dynein

Nintedanib targets core features of SSc in Fra2-transgenic mice and ameliorates histological features of pulmonary arterial hypertension, destructive microangiopathy and pulmonary and dermal fibrosis. These data might have direct implications for the ongoing phase III clinical trial with nintedanib in SSc-associated interstitial lung disease.

Fibroblasts are polymorphic cells with pleiotropic roles in organ morphogenesis, tissue homeostasis and immune responses. In fibrotic diseases, fibroblasts synthesize abundant amounts of extracellular matrix which lead to scaring and organ failure. In contrast, the hallmark feature of fibroblasts in arthritis is matrix degradation by the release of metalloproteinases and degrading enzymes, and subsequent tissue destruction. The mechanisms driving these functionally opposing pro-fibrotic and pro-inflammatory phenotypes of fibroblasts are enigmatic. We identified the transcription factor PU.1 as an essential orchestrator of the pro-fibrotic gene expression program. The interplay between transcriptional and post-transcriptional mechanisms which normally control PU.1 expression is perturbed in various fibrotic diseases, resulting in upregulation of PU.1, induction of fibrosis-associated gene sets, and a phenotypic switch in matrix-producing pro-fibrotic fibroblasts. In contrast, pharmacological and genetic inactivation of PU.1 disrupts the fibrotic network and enables re-programming of fibrotic fibroblasts into resting fibroblasts with regression of fibrosis in different organs.

Very large magnetoresistance discovered in single crystals of the ferromagnetic Fe-intercalated transition metal dichalcogenide, Fe0.28TaS2 was attributed to the deviation of the Fe concentration from commensurate values (x = 1/4 or 1/3), which caused magnetic moment misalignments. Here we report a study of FexTaS2 crystals with 0.23 ≤ x ≤ 0.35, demonstrating that crystallographic defects lead to spin disorder, which correlates with magneto-transport properties such as switching magnetic field HS, magnetoresistance MR, and even zero-field resistivity ρ0 and temperature coefficient A in ρ(T ) = ρ0 + AT 2 : The ordering temperature TC and Weiss temperature θW are maximized at the superstructure composition x = 1/4, while Hs, MR, ρ0, and A are minimum. Conversely, at a composition intermediate between the superstructure compositions x = 1/4 and 1/3, the corresponding magneto-transport properties reach local maxima.

Functional magnetic resonance imaging was used to explore the neural correlates of semantic judgments to Chinese characters. Adult participants were asked to indicate if character pairs were related in meaning that were arranged in a continuous variable according to association strength. This parametric manipulation allowed for a more precise determination of the role of the left inferior parietal lobule in processing meaning, which has not been reported in previous Chinese studies. Consistent with previous findings in English, participants showed activation in left inferior frontal gyrus (BA 47, 45) and left posterior middle temporal gyrus (BA 21). Characters with stronger semantic association elicited greater activation in left inferior parietal lobule (BA 39), suggesting stronger integration of highly related semantic features. By contrast, characters with weaker semantic association elicited greater activation in both an anterior ventral region (BA 47) and a mid-ventral region of left inferior frontal gyrus (BA 45), suggesting a controlled retrieval process and a selection process. Our findings of association strength are discussed in a proposed neuro-anatomical model of semantic processing.

Strong electron correlations are at the heart of many physical phenomena of current interest to the condensed matter community. Here we present a survey of the mechanisms underlying such correlations in charge density wave (CDW) systems, including the current theoretical understanding and experimental evidence for CDW transitions. The focus is on emergent phenomena that result as CDWs interact with other charge or spin states, such as magnetism and superconductivity. In addition to reviewing the CDW mechanisms in 1D, 2D, and 3D systems, we pay particular attention to the prevalence of this state in two particular classes of compounds, the high temperature superconductors (cuprates) and the layered transition metal dichalcogenides. The possibilities for quantum criticality resulting from the competition between magnetic fluctuations and electronic instabilities (CDW, unconventional superconductivity) are also discussed.