Segmentation of joint and musculoskeletal tissue in the study of arthritis

As the most frequent cause of physical disability, musculoskeletal diseases such as arthritis and osteoporosis have a great social and economical impact. Quantitative magnetic resonance imaging (MRI) biomarkers are important tools that allow clinicians to better characterize, monitor, and even predict musculoskeletal disease progression. Post-processing pipelines often include image segmentation. Manually identifying the border of the region of interest (ROI) is a difficult and time-consuming task. Manual segmentation is also affected by inter- and intrauser variability, thus limiting standardization. Fully automatic or semi-automatic methods that minimize the user interaction are highly desirable. Unfortunately, an ultimate, highly reliable and extensively evaluated solution for joint and musculoskeletal tissue segmentation has not yet been proposed, and many clinical studies still adopt fully manual procedures. Moreover, the clinical translation of several promising quantitative MRI techniques is highly affected by the lack of an established, fast, and accurate segmentation method. The goal of this review is to present some of the techniques proposed in recent literature that have been adopted in clinical studies for joint and musculoskeletal tissue analyses in arthritis patients. The most widely used MRI sequences and image processing algorithms employed to accomplish segmentation challenges will be discussed in this paper.     

Engineered nanomaterials exposure in the production of graphene

The objective of this study was to obtain the multi-metric occupational exposure assessment to graphene family nanomaterials (GFNs) particles of workers engaged in the large-scale production of graphene. The study design consisted of the combination of (i) direct-reading instruments, used to evaluate the total particle number concentrations relative to the background concentration (time series with spatial approach) and the mean size-dependent characteristics of particles (mean diameter and surface-area concentration) and (ii) filter-based air sampling for the determination of size-resolved particle mass concentrations. The data obtained from direct reading measurement were then used to estimate the 8-h time weighted average (8-h TWA) exposure to GFNs particles for workers involved in different working tasks. Workers were generally exposed to 8-h TWA GFNs particle levels lower than the proposed reference value (40,000 particle/cm³). Furthermore, despite high short-term exposure conditions were present during specific operations of the production process, the possibility of significant exposure peaks is not likely to be expected. The estimated 8-h TWA concentration showed differences between the unexposed (<100 particle/cm³; <0.05 µg/m³) and exposed subjects (mean concentration ranging from 909 to 6438 particle/cm³ and from 0.38 to 3.86 µg/m³). The research outcomes can be of particular interest because the exposure of workers in real working conditions was assessed with a multi-metric approach; in this regard, the study suggests that workers who are directly involved in some specific working task (material sampling for quality control) have higher potential for occupational exposure than operators who are in charge of routine production work.

© 2016 American Association for Aerosol Research     

Nearshore benthic blooms of filamentous green algae in Lake Baikal

For the first time, species of the genus Spirogyra, non-typical of the open nearshore waters of Lake Baikal, formed algal mats with Ulothrix zonata, Ulothrix tenerrima, and Ulothrix tenuissima near the village of Listvyanka, Russia. Normally widely distributed in the 0- to 1.5-m depth range, the growth of U. zonata was now evident and dominant (63% of the biomass) in the 2- to 5-m depth range. The overgrowth of the lake bottom by filamentous green algae, changes in distributional boundaries, the emergence and mass development of species of the genus Spirogyra, the presence of the eutrophic diatom indicator Fragilaria capucina var. vaucheriae, elevated abundances of coliform bacteria, and elevated levels of nutrients suggest an early stage of cultural eutrophication in the nearshore of Lake Baikal near Listvyanka, a popular tourist destination. The unusual abundance of Fragilaria associated with the filamentous green algae consisted of long-ribbon colonies of F. capucina var. vaucheriae, a eutrophic species, wound around the filamentous green algae, enhancing the dense algae mats. Historically dominant species, such as Didymosphenia geminata, Tetraspora cylindrica var. bullosa, and Draparnaldioides baicalensis typically observed at deeper depths of Lake Baikal, are now subdominants or minor species in the nearshore along the shoreline near Listvyanka.     

Visual analysis of geospatial habitat suitability model based on inverse distance weighting with paired comparison analysis

Geospatial data analytical model is developed in this paper to model the spatial suitability of malaria outbreak in Vellore, Tamil Nadu, India. In general, Disease control strategies are only the spatial information like landscape, weather and climate, but also spatially explicit information like socioeconomic variable, population density, behavior and natural habits of the people. The spatial multi-criteria decision analysis approach combines the multi-criteria decision analysis and geographic information system (GIS) to model the spatially explicit and implicit information and to make a practical decision under different scenarios and different environment. Malaria is one of the emerging diseases worldwide; the cause of malaria is weather & climate condition of the study area. The climate condition is often called as spatially implicit information, traditional decision-making models do not use the spatially implicit information it most often uses spatially explicit information such as socio-economic, natural habits of the people. There is need to develop an integrated approach that consists of spatially implicit and explicit information. The proposed approach is used to identity an effective control strategy that prevents and control of malaria. Inverse Distance Weighting (IDW) is a type of deterministic method used in this paper to assign the weight values based on the neighborhood locations. ArcGIS software is used to develop the geospatial habitat suitability model.     

Optimal transient performance under output set‐point reset

The purpose of this paper is to propose a new method for the optimization of the output transition in the case of set‐point reset for LTI, non‐minimum phase, possibly non‐hyperbolic plants. Assuming that the plant is stabilized by a proper feedback controller, the problem consists in finding a feedforward linear filter yielding a suitable reference trajectory for the closed‐loop system. The approach situates in the framework of model pseudo‐inversion because the external reference trajectory is computed starting from some desired features of the transient output between the two set points. A significant aspect of the new method is that the transition trajectory is not ‘ad hoc’ exactly prespecified by the designer. Rather, it is implicitly defined by the procedure for the minimization of a suitable multi‐objective quadratic cost functional. As no pre‐actuation is required, the method can be practically implemented on line and also works for the critical class of non‐hyperbolic systems. Copyright © 2015 John Wiley & Sons, Ltd.     

Application of flower pollination algorithm in load frequency control of multi-area interconnected power system with nonlinearity

This work presents an application of bio-inspired flower pollination algorithm (FPA) for tuning proportional–integral–derivative (PID) controller in load frequency control (LFC) of multi-area interconnected power system. The investigated power system comprises of three equal thermal power systems with appropriate PID controller. The controller gain [proportional gain (K _p), integral gain (K _i) and derivative gain (K _d)] values are tuned by using the FPA algorithm with one percent step load perturbation in area 1 (1 % SLP). The integral square error (ISE) is considered the objective function for the FPA. The supremacy performance of proposed algorithm for optimized PID controller is proved by comparing the results with genetic algorithm (GA) and particle swarm optimization (PSO)-based PID controller under the same investigated power system. In addition, the controller robustness is studied by considering appropriate generate rate constraint with nonlinearity in all areas. The result cumulative performance comparisons established that FPA-PID controller exhibit better performance compared to performances of GA-PID and PSO-PID controller-based power system with and without nonlinearity effect.

     

How governance mechanisms in family firms impact open innovation choices: A fuzzy logic approach

The inbound open innovation (OI) process consists of the opening of the innovation funnel to the contribution of external partners, with the aim of tapping into their knowledge. This opportunity is particularly valuable for family firms (FFs), which often have insufficient resources. However, the literature on the OI behaviour of family firms is not conclusive. Indeed, both the behavioural theory (BT) and the resource‐based view (RBV) posit negative and positive outcomes regarding openness choices in FFs. We claim that these contrasting results can be reconciled if, according to the literature, FFs are seen as a heterogeneous breed, whose differences are determined by different levels of participation of non‐family members in the governance mechanisms. Indeed, non‐family members can act in favour of OI. However, previous literature has failed to satisfactorily grasp the nuances of this heterogeneity. We suggest that it is necessary to adequately operationalize the heterogeneity concept by means of fuzzy logic. We conducted a survey on 178 Italian FFs. Results show that the involvement of non‐family members affects the extent to which firms draw on knowledge from external partners. Specifically, the higher the involvement of non‐family members, the more there is collaboration with vertical partners along the supply chain.     

“Solving” ambiguity in the virtual space: communication strategies in a collaborative virtual environment

Collaborative virtual environments (CVE) face the challenge of succeeding in incorporating critical dimensions of cooperation and communication in everyday working situations. One of these dimensions, situation ambiguity, is scarcely considered in studies on CVE although it can prove a key factor in future use of CVE in real work situations. Many computer-supported cooperative environments and telecommunication systems, like those currently used in telemedicine, would benefit from the incorporation of some degree of situation ambiguity allowing users to deploy their diagnostic and interpretive abilities. In the perspective adopted in this study, ambiguity is the contingent outcome of the ongoing interaction taking place between the environment and the interests of social actors. The research focuses on the cooperation within couples of participants facing situation ambiguity in a virtual environment: a simulated city named Babylon. Participants moved in the city through an avatar and could communicate in one of the following conditions: face-to-face, phone or chat. Their goal was that of meeting somewhere in the city, in a place that they did not know previously. Babylon contained elements designed to allow both production and detection of ambiguity. Ambiguity emerged when participants realized the presence of inconsistencies in the way they perceived the situations they had to face. The moments in which ambiguity was perceived—called “critical events” (CE)—were measured and described through qualitative (ethnographically oriented) methods. The different strategies that participants used to “solve” ambiguity were characterized as: looking for environmental cues, narrowing the focus of attention and investing on cooperation. Both CEs and strategies were analyzed with respect to the three communication conditions: face-to-face, phone and chat. All the communication conditions allowed the emergence of ambiguity and the negotiation of strategies to solve ambiguity between partners: according to literature, chat is very costly in terms of time spent on writing but this disadvantage did not block completely the emergence of ambiguity and the development of adequate strategies of solution. All navigations but three (on a total of 18 couples) succeeded: the partners did meet in a short time (less than 15 min) relying on their pragmatic resources in a new virtual place. Further research is required to clarify the possible factors influencing the choice of one strategy over the others, the order in which strategies follow each other and the role of leadership in ambiguity detection and solution.