7,314 research outputs found
Congruent and Incongruent Corticospinal Activations at the Level of Multiple Effectors
Motor resonance is defined as the subliminal activation of the motor system while observing actions performed by others. However, resonating with another person's actions is not always an appropriate response: In real life, people do not just imitate but rather respond in a suitable fashion. A growing body of neurophysiologic studies has demonstrated that motor resonance can be overridden by complementary motor responses (such as preparing a precision grip on a small object when seeing an open hand in sign of request). In this study, we investigated the relationship between congruent and incongruent corticospinal activations at the level of multiple effectors. The modulation of MEPs evoked by single-pulse TMS over the motor cortex was assessed in upper and lower limb muscles of participants observing a soccer player performing a penalty kick straight in their direction. Study results revealed a double dissociation: Seeing the soccer player kicking the ball triggered a motor resonance in the observer's lower limb, whereas the upper limb response afforded by the object was overridden. On the other hand, seeing the ball approaching the observers elicited a complementary motor activation in upper limbs while motor resonance in lower limbs disappeared. Control conditions showing lateral kicks, mimicked kicks, and a ball in penalty area were also included to test the motor coding of object affordances. Results point to a modulation of motor responses in different limbs over the course of action and in function of their relevance in different contexts. We contend that ecologically valid paradigms are nowadays needed to shed light on the motor system functioning in complex forms of interaction
Factors influencing the pricing of applications in the Apple App Store: A developers\u2019 perspective
Many know how Apple Inc. owes its success in Mobile Commerce to the introduction of the new \u201cApp Store\u201d business model. This new market is characterized by the opening to third party mobile apps, which are distributed to consumers through the App Store. This paper investigates factors that might influence the pricing of applications in the Apple Mobile Application Store.
By reviewing the existing literature on the issue and analyzing the strategic features characterizing the App Store, we detect three main factors that could influence prices for apps, that is the number of developed apps, the presence of two-sided network externalities and developer\u2019s specialization. An empirical analysis on data from 68,220 apps downloaded from the Italian App Store is used to test the hypotheses. Regression results support our hypotheses. We argue, that even if the research here presented can be considered as a started analysis to the pricing problem in such markets, this work may have important managerial implication for the thousands of developers that are competing in this emerging market
Instantaneous cell migration velocity may be ill-defined
Cell crawling is critical to biological development, homeostasis and disease.
In many cases, cell trajectories are quasi-random-walk. In vitro assays on flat
surfaces often described such quasi-random-walk cell trajectories as
approximations to a solution of a Langevin process. However, experiments show
quasi-diffusive behavior at small timescales, indicating that instantaneous
velocity and velocity autocorrelations are not well-defined. We propose to
characterize mean-squared cell displacement using a modified F\"urth equation
with three temporal and spatial regimes: short- and long-time/range diffusion
and intermediate time/range ballistic motion. This analysis collapses
mean-squared displacements of previously published experimental data onto a
single-parameter family of curves, allowing direct comparison between movement
in different cell types, and between experiments and numerical simulations. Our
method also show that robust cell-motility quantification requires an
experiment with a maximum interval between images of a few percent of the
cell-motion persistence time or less, and a duration of a few
orders-of-magnitude longer than the cell-motion persistence time or more.Comment: 5 pages, plus Supplemental materia
Synthetic perspective optical flow: Influence on pilot control tasks
One approach used to better understand the impact of visual flow on control tasks has been to use synthetic perspective flow patterns. Such patterns are the result of apparent motion across a grid or random dot display. Unfortunately, the optical flow so generated is based on a subset of the flow information that exists in the real world. The danger is that the resulting optical motions may not generate the visual flow patterns useful for actual flight control. Researchers conducted a series of studies directed at understanding the characteristics of synthetic perspective flow that support various pilot tasks. In the first of these, they examined the control of altitude over various perspective grid textures (Johnson et al., 1987). Another set of studies was directed at studying the head tracking of targets moving in a 3-D coordinate system. These studies, parametric in nature, utilized both impoverished and complex virtual worlds represented by simple perspective grids at one extreme, and computer-generated terrain at the other. These studies are part of an applied visual research program directed at understanding the design principles required for the development of instruments displaying spatial orientation information. The experiments also highlight the need for modeling the impact of spatial displays on pilot control tasks
Real-time cell analysis by xCELLigence®: a new method for dynamic, quantitative measurement of adhesion and proliferation of cell lines
Objectives. In this study, we report the use of a real-time cell analysis (RTCA) test system, the xCELLigence® RTCA, as efficient tool for a fast growth kinetics analysis of cell lines. This new dynamic real-time monitoring and impedance-based assay allows for a combined measurement of cell adhesion, spreading and proliferation. Methods. We used four representative human OSCC derived cell lines, PE49, HSC2, HSC3 and PE15 cells. The measured impedance values could be correlated to characteristic cell culture behaviours. In parallel, were evaluated proliferation
and cell viability of the cell lines by the 3-[4,5-dimethylthizol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Results. Through the analysis we were able to quantitatively characterize the growth kinetics of the cell lines. The results are in agreement with the analysis MTT and for us will be the basis for future studies with respect to these lines.Conclusions. The advantage of impedance-based measurements is mainly based on these continuous monitoring of
cell responses for a broad range of different cells and with different parameters of culture. Therefore, the xCELLigence system can be used as a rapid monitoring tool for cellular viability and used for multiple applications, such as toxicity testing
of xenobiotics, biocompatibility of dental materials, tests of invasion and migration using in vitro cell cultures
Dianthus borbonicus (Caryophyllaceae), a new species from Sicily
Dianthus borbonicus a new species occurring in North-Western Sicily is described and illustrated. It is a rare chasmophyte
belonging to the D. sylvestris group, which is exclusive of a rupestrian stand near Rocca Busambra (Ficuzza). Its macro- and
micromorphological features (seed testa sculptures, and leaf anatomy), ecology, conservation status and a comparison with
the related species are provided too
ENDOCANNABINOIDS CB1 AND CB2: A POSSIBLE ROLE IN ORAL SQUAMOUS CELL CARCINOMA PATHOGENESIS
Aim. Cancer of the oral cavity is the eighth most common malignancy in the world. The disease is diagnosed after a considerable delay and predict the individual progression is difficult. The improvements of the therapy did not increased the rate of survival at 5 years, that is still about 50%. The
identification of the possible markers that indicates the progression of the tumor is therefore necessary.
Endocannabinoids may play an important role in the process of carcinogenesis in the oral mucosa. They are able to bind and activate specific membrane receptors coupled to G proteins, cannabinoid receptors CB1 and CB2. The purpose of this study is to evaluate the expression of CB1 and CB2 receptors in the development of oral cancer through the immunohistochemical study on samples of OSCC. Materials and methods. We selected 44 cases of patients with the primary tumor in the oral cavity. The stage of the tumor was classified according to the TNM system. The tumors grading was divided into I, II and III grade. The paraffin sections were analyzed by immunohistochemistry. The assessment of the immunoreactivity for CB1 and CB2 receptors was weak or strong. For quantitative analysis the expression
of CB1 and CB2 receptors was evaluated in percentage with scale of values ??ranging from 0 to 100%.
Results. The immunohistochemical examination of the samples analyzed showed the absence of expression of CB1 and CB2 receptors in normal mucosa, while peritumoral mucosa showed a weak expression in the vicinity of cancer and tumor mucosa showed an overexpression of receptors.
Furthermore, the intensity of staining increased with the increase of the grading. It can be concluded
that the strong immunoreactivity of CB1 and CB2 receptors is related to aggressive behavior of oral
carcinoma. Conclusions. The analysis of endocannabinoids and their receptors on tissue biopsies taken from carcinoma of the oral cavity may therefore indicate future therapeutic targets and new prognostic
biomarkers in these patients, especially in the early stages of the disease. The ultimate goal of this work is to indicate the possible role of CB1 and CB2 receptors such as tumor biomarker that may help in the
early diagnosis of oral cancer and therefore contribute to reduce drastically the mortality of this disease
The monoclonal antibody nBT062 conjugated to maytansinoids has potent and selective cytotoxicity against CD138 positive multiple myeloma cells _in vitro_ and _in vivo_
CD138 (Syndecan1) is highly expressed on multiple myeloma (MM) cells. In this study, we examined the anti-MM effect of murine/human chimeric CD138-specific monoclonal antibody (mAb) nBT062 conjugated with highly cytotoxic maytansinoid derivatives _in vitro_ and _in vivo_. These agents significantly inhibited growth of CD138-positive MM cell lines and primary tumor cells from MM patients, without cytotoxicity against peripheral blood mononuclear cells from healthy volunteers. In MM cells, they induced G2/M cell cycle arrest followed by apoptosis associated with cleavage of PARP and caspase-3, -8 and -9. Non-conjugated nBT062 completely blocked cytotoxicity induced by nBT062-maytansinoid conjugate, confirming that binding is required for inducing cytotoxicity. Moreover, nBT062-maytansinoid conjugates blocked adhesion of MM cells to bone marrow stromal cells (BMSCs). Co-culture of MM cells with BMSCs, which protects against dexamethasone-induced death, had no impact on the cytotoxicity of the immunoconjugates. Importantly, nBT062-SPDB-DM4 and nBT062-SPP-DM1 significantly inhibited MM tumor growth _in vivo_ in both human multiple myeloma xenograft mouse models and in SCID-human bone grafts (SCID-hu mouse model). These studies provide the preclinical framework supporting evaluation of nBT062-maytansinoid derivatives in clinical trials to improve patient outcome in MM
Stability of casein micelles cross-linked with genipin: a physicochemical study as a function of pH
Chemical or enzymatic cross-linking of casein micelles (CMs) increases their
stability against dissociating agents. In this paper, a comparative study of
stability between native CMs and CMs cross-linked with genipin (CMs-GP) as a
function of pH is described. Stability to temperature and ethanol were
investigated in the pH range 2.0-7.0. The size and the charge
(-potential) of the particles were determined by dynamic light
scattering. Native CMs precipitated below pH 5.5, CMs-GP precipitated from pH
3.5 to 4.5, whereas no precipitation was observed at pH 2.0-3.0 or pH 4.5-7.0.
The isoelectric point of CMs-GP was determined to be pH 3.7. Highest stability
against heat and ethanol was observed for CMs-GP at pH 2, where visible
coagulation was determined only after 800 s at 140 C or 87.5% (v/v) of
ethanol. These results confirmed the hypothesis that cross-linking by GP
increased the stability of CMs.Comment: 5 pages, 2 figures, International Dairy Journal, 201
Recent advances in smart biotechnology: Hydrogels and nanocarriers for tailored bioactive molecules depot
Over the past ten years, the global biopharmaceutical market has remarkably grown, with ten over the top twenty worldwide high performance medical treatment sales being biologics. Thus, biotech R&D (research and development) sector is becoming a key leading branch, with expanding revenues. Biotechnology offers considerable advantages compared to traditional therapeutic approaches, such as reducing side effects, specific treatments, higher patient compliance and therefore more effective treatments leading to lower healthcare costs. Within this sector, smart nanotechnology and colloidal self-assembling systems represent pivotal tools able to modulate the delivery of therapeutics. A comprehensive understanding of the processes involved in the self assembly of the colloidal structures discussed therein is essential for the development of relevant biomedical applications. In this review we report the most promising and best performing platforms for specific classes of bioactive molecules and related target, spanning from siRNAs, gene/plasmids, proteins/growth factors, small synthetic therapeutics and bioimaging probes.Istituto Italiano di Tecnologia (IIT)COST Action [CA 15107]People Program (Marie Curie Actions) of the European Union's Seventh Framework Program under REA [606713 BIBAFOODS]Portuguese Foundation for Science and Technology (FCT) [PTDC/AGR-TEC/4814/2014, IF/01005/2014]Fundacao para a Ciencia e Tecnologia [SFRH/BPD/99982/2014]Danish National Research Foundation [DNRF 122]Villum Foundation [9301]Italian Ministry of Instruction, University and Research (MIUR), PRIN [20109PLMH2]"Fondazione Beneficentia Stiftung" VaduzFondo di Ateneo FRAFRAinfo:eu-repo/semantics/publishedVersio
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