445 research outputs found
Endothelial and cancer cells interact with mesenchymal stem cells via both microparticles and secreted factors
Tightly associated with blood vessels in their perivascular niche, human mesenchymal stem cells (MSCs) closely interact with endothelial cells (ECs). MSCs also home to tumours and interact with cancer cells (CCs). Microparticles (MPs) are cell-derived vesicles released into the extracellular environment along with secreted factors. MPs are capable of intercellular signalling and, as biomolecular shuttles, transfer proteins and RNA from one cell to another. Here, we characterize interactions among ECs, CCs and MSCs via MPs and secreted factors in vitro. MPs and non-MP secreted factors (Sup) were isolated from serum-free medium conditioned by human microvascular ECs (HMEC-1) or by the CC line HT1080. Fluorescently labelled MPs were prepared from cells treated with membrane dyes, and cytosolic GFP-containing MPs were isolated from cells transduced with CMV-GFP lentivirus. MSCs were treated with MPs, Sup, or vehicle controls, and analysed for MP uptake, proliferation, migration, activation of intracellular signalling pathways and cytokine release. Fluorescently labelled MPs fused with MSCs, transferring the fluorescent dyes to the MSC surface. GFP was transferred to and retained in MSCs incubated with GFP-MPs, but not free GFP. Thus, only MP-associated cellular proteins were taken up and retained by MSCs, suggesting that MP biomolecules, but not secreted factors, are shuttled to MSCs. MP and Sup treatment significantly increased MSC proliferation, migration, and MMP-1, MMP-3, CCL-2/MCP-1 and IL-6 secretion compared with vehicle controls. MSCs treated with Sup and MPs also exhibited activated NF-κB signalling. Taken together, these results suggest that MPs act to regulate MSC functions through several mechanisms
Lizard tail regeneration: regulation of two distinct cartilage regions by Indian hedgehog
AbstractLizards capable of caudal autotomy exhibit the remarkable ability to “drop” and then regenerate their tails. However, the regenerated lizard tail (RLT) is known as an “imperfect replicate” due to several key anatomical differences compared to the original tail. Most striking of these “imperfections” concerns the skeleton; instead of the vertebrae of the original tail, the skeleton of the RLT takes the form of an unsegmented cartilage tube (CT). Here we have performed the first detailed staging of skeletal development of the RLT CT, identifying two distinct mineralization events. CTs isolated from RLTs of various ages were analyzed by micro-computed tomography to characterize mineralization, and to correlate skeletal development with expression of endochondral ossification markers evaluated by histology and immunohistochemistry. During early tail regeneration, shortly after CT formation, the extreme proximal CT in direct contact with the most terminal vertebra of the original tail develops a growth plate-like region that undergoes endochondral ossification. Proximal CT chondrocytes enlarge, express hypertrophic markers, including Indian hedgehog (Ihh), apoptose, and are replaced by bone. During later stages of tail regeneration, the distal CT mineralizes without endochondral ossification. The sub-perichondrium of the distal CT expresses Ihh, and the perichondrium directly calcifies without cartilage growth plate formation. The calcified CT perichondrium also contains a population of stem/progenitor cells that forms new cartilage in response to TGF-β stimulation. Treatment with the Ihh inhibitor cyclopamine inhibited both proximal CT ossification and distal CT calcification. Thus, while the two mineralization events are spatially, temporally, and mechanistically very different, they both involve Ihh. Taken together, these results suggest that Ihh regulates CT mineralization during two distinct stages of lizard tail regeneration
Tendenze della contrattazione nazionale in materia di contratto a termine, part-time e apprendistato professionalizzante = National bargaining trends in the term, part-time and professionalizing apprenticeship. WP C.S.D.L.E. “Massimo D’Antona”.IT – 186/2013
The study aims to analyse the most relevant rules set by collective agreements in the ‘private sector’ concerning fixed-term, part-time and professional apprenticeship contracts, whose contractual clauses are more widespread, consistent and significant, due also to several references in the legal frame to the collective bargaining. Some of these legislative references, introduced in recent years/months, assign an important task to the collective bargaining, which is called to decide whether and how to implement the contract regulation. The main regulatory trends in the national collective agreements, integrated within the ‘legislative framework’, which is often the result of frequent and contradictory reforms, may allow an overall evaluation of the legal framework concerning those three above-mentioned work contracts. The frequent changes of the legal framework determine a fast obsolescence of contractual clauses and require a careful comparison and interpretation in the light of subsequent legislative reforms. The study also provides several parameters to verify, within this scope, if and how the collective clauses have changed through time (or will eventually change), also with regard to legal references to collective bargaining, and to measure the risk, the importance and the scope of eventual regulative derogations provided for by so called “intese specifiche” (special regulations) (art. 8, Decree n. 138, 13.8.2011, converted, with amendments, in l. 14.9.2011, n. 148). Furthermore, the essay offers a review of the most recent collective agreements, examined more analytically in this perspective, and describes in more details the main choices made by national collective agreements, taking into account the market conditions
Terminal Area Procedures for Paired Runways
Parallel Runway operations have been found to increase capacity within the National Airspace (NAS) however, poor visibility conditions reduce this capacity [1]. Much research has been conducted to examine the concepts and procedures related to parallel runways however, there has been no investigation of the procedures associated with the strategic and tactical pairing of aircraft for these operations. This study developed and examined the pilot and controller procedures and information requirements for creating aircraft pairs for parallel runway operations. The goal was to achieve aircraft pairing with a temporal separation of 15s(+/- 10s error) at a coupling point that is about 12 nmi from the runway threshold. Two variables were explored for the pilot participants: Two levels of flight deck automation (current-day flight deck automation, and a prototype future automation) as well as two flight deck displays that assisted in pilot conformance monitoring. The controllers were also provided with automation to help create and maintain aircraft pairs. Data showed that the operations in this study were found to be acceptable and safe. Workload when using the pairing procedures and tools was generally low for both controllers and pilots, and situation awareness (SA) was typically moderate to high. There were some differences based upon the display and automation conditions for the pilots. Future research should consider the refinement of the concepts and tools for pilot and controller displays and automation for parallel runway concepts
Self-Care Practices among Geriatric Social Workers
Within the social work profession, there is a lack of understanding about self-care practices of social workers working with older adults. This lack of knowledge is a concern for the profession because as the older adult population continues to grow, so will the need for social workers to address their needs. Using action research, a focus group of 7 female social workers working with older adults in the Pacific Northwest discussed the research questions related to their use of self-care practices and identifying strategies to increase the use of self-care. Self-compassion theory enhanced understanding the relationship between social workers\u27 experiences with older adult clients and self-care. Coding protocols were used to analyze the data. Key findings provided a further understanding of the self-care practices of these social workers including the use of appropriate boundaries, effective communication, education about responsibilities and expectations, and advocacy regarding the need for self-care. Additional strategies to increase self-care involved mindfulness about job roles, primarily related to team and system barriers. Recommendations from this project included adding self-care to education and training in social work courses required for degrees, licensure renewal, and employment-based continuing education courses. By exploring self-care practices of social workers working with older adults, the findings of this study may bring about social change by increasing the awareness of current and future social workers about the importance of self-care and providing strategies that enable social workers to implement self-care
Perception of aircraft Deviation Cues
To begin to address the need for new displays, required by a future airspace concept to support new roles that will be assigned to flight crews, a study of potentially informative display cues was undertaken. Two cues were tested on a simple plan display - aircraft trajectory and flight corridor. Of particular interest was the speed and accuracy with which participants could detect an aircraft deviating outside its flight corridor. Presence of the trajectory cue significantly reduced participant reaction time to a deviation while the flight corridor cue did not. Although non-significant, the flight corridor cue seemed to have a relationship with the accuracy of participants judgments rather than their speed. As this is the second of a series of studies, these issues will be addressed further in future studies
Role of the Controller in an Integrated Pilot-Controller Study for Parallel Approaches
Closely spaced parallel runway operations have been found to increase capacity within the National Airspace System but poor visibility conditions reduce the use of these operations [1]. Previous research examined the concepts and procedures related to parallel runways [2][4][5]. However, there has been no investigation of the procedures associated with the strategic and tactical pairing of aircraft for these operations. This study developed and examined the pilot s and controller s procedures and information requirements for creating aircraft pairs for closely spaced parallel runway operations. The goal was to achieve aircraft pairing with a temporal separation of 15s (+/- 10s error) at a coupling point that was 12 nmi from the runway threshold. In this paper, the role of the controller, as examined in an integrated study of controllers and pilots, is presented. The controllers utilized a pairing scheduler and new pairing interfaces to help create and maintain aircraft pairs, in a high-fidelity, human-in-the loop simulation experiment. Results show that the controllers worked as a team to achieve pairing between aircraft and the level of inter-controller coordination increased when the aircraft in the pair belonged to different sectors. Controller feedback did not reveal over reliance on the automation nor complacency with the pairing automation or pairing procedures
Exploring the role of attention during implicit memory retrieval
Implicit memory is memory for information that is not driven by conscious processing. This study investigated the role of attention during implicit memory retrieval across four experiments using a test-phase division of attention. Implicit retrieval is dissociable into perceptual and conceptual forms. Implicit retrieval is further dissociable into tests that involve stimulus identification or stimulus production. Several lines of research make predictions about implicit retrieval in general, and with respect to these two dissociations. The present study used four implicit tests that can be classified according to each of these two dimensions. Experiment 1 used a perceptual identification test; Experiment 2 used a word-stem completion test; Experiment 3 used a category exemplar production test; and Experiment 4 used a category verification test. Attention was divided during the test-phase only with one of several secondary tasks. It was found that, across all experiments, none of the secondary tasks reduced levels of priming for any of the implicit tests. Further, implicit retrieval had no detrimental effects on performance for any of the secondary tasks. All of the above support the idea that implicit retrieval is automatic
Hybrid Neural Network Approach Based Tool for the Modelling of Photovoltaic Panels
A hybrid neural network approach based tool for identifying the photovoltaic one-diode model is presented. The generalization capabilities of neural networks are used together with the robustness of the reduced form of one-diode model. Indeed, from the studies performed by the authors and the works present in the literature, it was found that a direct computation of the five parameters via multiple inputs and multiple outputs neural network is a very difficult task. The reduced form consists in a series of explicit formulae for the support to the neural network that, in our case, is aimed at predicting just two parameters among the five ones identifying the model: the other three parameters are computed by reduced form. The present hybrid approach is efficient from the computational cost point of view and accurate in the estimation of the five parameters. It constitutes a complete and extremely easy tool suitable to be implemented in a microcontroller based architecture. Validations are made on about 10000 PV panels belonging to the California Energy Commission database
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