Audio Event Detection using Weakly Labeled Data

Acoustic event detection is essential for content analysis and description of multimedia recordings. The majority of current literature on the topic learns the detectors through fully-supervised techniques employing strongly labeled data. However, the labels available for majority of multimedia data are generally weak and do not provide sufficient detail for such methods to be employed. In this paper we propose a framework for learning acoustic event detectors using only weakly labeled data. We first show that audio event detection using weak labels can be formulated as an Multiple Instance Learning problem. We then suggest two frameworks for solving multiple-instance learning, one based on support vector machines, and the other on neural networks. The proposed methods can help in removing the time consuming and expensive process of manually annotating data to facilitate fully supervised learning. Moreover, it can not only detect events in a recording but can also provide temporal locations of events in the recording. This helps in obtaining a complete description of the recording and is notable since temporal information was never known in the first place in weakly labeled data.Comment: ACM Multimedia 201

Complementary, Semi-automated Methods for Creating Multi-dimensional, PEG-based Biomaterials

Tunable biomaterials that mimic selected features of the extracellular matrix (ECM), such as its stiffness, protein composition, and dimensionality, are increasingly popular for studying how cells sense and respond to ECM cues. In the field, there exists a significant trade-off for how complex and how well these biomaterials represent the in vivo microenvironment, versus how easy they are to make and how adaptable they are to automated fabrication techniques. To address this need to integrate more complex biomaterials design with high-throughput screening approaches, we present several methods to fabricate synthetic biomaterials in 96-well plates and demonstrate that they can be adapted to semiautomated liquid handling robotics. These platforms include 1) glass bottom plates with covalently attached ECM proteins, and 2) hydrogels with tunable stiffness and protein composition with either cells seeded on the surface, or 3) laden within the three-dimensional hydrogel matrix. This study includes proof-of-concept results demonstrating control over breast cancer cell line phenotypes via these ECM cues in a semi-automated fashion. We foresee the use of these methods as a mechanism to bridge the gap between high-throughput cell-matrix screening and engineered ECM-mimicking biomaterials

Applicability of Drug Response Metrics for Cancer Studies using Biomaterials

Bioengineers have built models of the tumour microenvironment (TME) in which to study cell–cell interactions, mechanisms of cancer growth and metastasis, and to test new therapies. These models allow researchers to culture cells in conditions that include features of the in vivo TME implicated in regulating cancer progression, such as extracellular matrix (ECM) stiffness, integrin binding to the ECM, immune and stromal cells, growth factor and cytokine depots, and a three-dimensional geometry more representative of the in vivo TME than tissue culture polystyrene (TCPS). These biomaterials could be particularly useful for drug screening applications to make better predictions of efficacy, offering better translation to preclinical models and clinical trials. However, it can be challenging to compare drug response reports across different biomaterial platforms in the current literature. This is, in part, a result of inconsistent reporting and improper use of drug response metrics, and vast differences in cell growth rates across a large variety of biomaterial designs. This study attempts to clarify the definitions of drug response measurements used in the field, and presents examples in which these measurements can and cannot be applied. We suggest as best practice to measure the growth rate of cells in the absence of drug, and follow our ‘decision tree’ when reporting drug response metrics

Comparative Study of Multicellular Tumor Spheroid Formation Methods and Implications for Drug Screening

Improved in vitro models are needed to better understand cancer progression and bridge the gap between in vitro proof-of-concept studies, in vivo validation, and clinical application. Multicellular tumor spheroids (MCTS) are a popular method for three-dimensional (3D) cell culture, because they capture some aspects of the dimensionality, cell–cell contact, and cell–matrix interactions seen in vivo. Many approaches exist to create MCTS from cell lines, and they have been used to study tumor cell invasion, growth, and how cells respond to drugs in physiologically relevant 3D microenvironments. However, there are several discrepancies in the observations made of cell behaviors when comparing between MCTS formation methods. To resolve these inconsistencies, we created and compared the behavior of breast, prostate, and ovarian cancer cells across three MCTS formation methods: in polyNIPAAM gels, in microwells, or in suspension culture. These methods formed MCTS via proliferation from single cells or passive aggregation, and therefore showed differential reliance on genes important for cell–cell or cell–matrix interactions. We also found that the MCTS formation method dictated drug sensitivity, where MCTS formed over longer periods of time via clonal growth were more resistant to treatment. Toward clinical application, we compared an ovarian cancer cell line MCTS formed in polyNIPAAM with cells from patient-derived malignant ascites. The method that relied on clonal growth (PolyNIPAAM gel) was more time and cost intensive, but yielded MCTS that were uniformly spherical, and exhibited the most reproducible drug responses. Conversely, MCTS methods that relied on aggregation were faster, but yielded MCTS with grape-like, lobular structures. These three MCTS formation methods differed in culture time requirements and complexity, and had distinct drug response profiles, suggesting the choice of MCTS formation method should be carefully chosen based on the application required

Prevalence of apical periodontitis and endodontic treatment in a Kosovar adult population

<p>Abstract</p> <p>Background</p> <p>Despite numerous studies on the prevalence of apical periodontitis (AP) and endodontic treatment in diverse geographical populations, there are currently no data on the prevalence of these conditions in populations of adults native to Kosovo. Therefore, little is known about how widespread these conditions are, and whether there is any correlation between root canal treatment and AP. The purpose of our research was to address this anomaly by investigating AP and endodontic treatment in an adult Kosovar population based on radiographic examination.</p> <p>Methods</p> <p>The sample used for this study consisted of randomly selected individuals referred to the University Dentistry Clinical Center of Kosovo in the years 2006-2007. Orthopantomographs of 193 patients were evaluated. The periapical status of all teeth (with the exception of third molars) was examined according to Ørstavik's Periapical Index. The quality of the root canal filling was rated as 'adequate' or 'inadequate' based on whether all canals were filled, the depth of fill relative to the radiographic apex and the quality of compaction (absence/presence of voids). Data were analyzed statistically using the Chi-square test and calculation of odds ratios.</p> <p>Results</p> <p>Out of 4131 examined teeth, the prevalence of apical periodontitis (AP) and endodontic treatment was 12.3% and 2.3%, respectively. Of 95 endodontically-treated teeth, 46.3% were associated with AP. The prevalence of AP increased with age. The prevalence in subjects aged over 60 years old (20.2%) was higher than in other age groups. A statistically significant difference was found for the frequency of endodontically-treated teeth associated with AP in the 40-49 year age group (P < 0.001). Of some concern was the discovery that only 30.5% of the endodontically-treated teeth examined met the criteria of an acceptable root canal filling. Inadequately root-filled teeth were associated with an increased AP risk.</p> <p>Conclusions</p> <p>The prevalence of AP and the frequency of endodontically-treated teeth with AP in this Kosovar population are higher than those found in other countries. Inadequate root canal fillings were associated with an increased prevalence of AP.</p

Effects of initial fattening age on carcass characteristics and meat quality in Simmental bulls imported from Austria to Turkey

The aim of this study was to determine the effects of initial fattening age on carcass and meat quality of Simmental bulls imported from Austria to Turkey. These animals were allocated to two initial ages of fattening groups, namely young (n = 74) and old group (n = 61) at 5.5 and 7.5 months old, respectively. After reaching the target final weights, the animals were slaughtered and the carcass characteristics, area and circumference of the longissimus thoracis et lumborum (LTL) muscle, marbling score, and meat quality, including cooking loss, water-holding capacity (WHC), shear force (WBSF), and colour parameters were evaluated in six animals per group. A comparison of hot and cold carcass weights and dressing percentages, LTL circumference, fat thickness values and marbling score indicated no significant differences between young and old groups. However, the LTL area was significantly affected by the initial age. There were no significant differences between groups in WHC, cooking loss, and WBSF values and meat colour parameters. The results of this study showed that the initial fattening age of bulls showed no significant effect on carcass and meat quality parameters, except the LTL area. The LTL area was significantly higher in young group than the old group. Further studies are needed to improve carcass and meat quality of imported Simmental bulls through modifying the initial fattening age.Keywords: Age, beef, carcass quality, Simmenta