21 research outputs found
Rearfoot kinematics in distance runners: association with overuse injuries
Distance runners suffer often from overuse injures, caused by excessive pronation or supinating foot. The purpose of this study was to compare the rearfoot kinematics and the questionnaire results of incidences of overuse injuries symptoms. Fourteen distance runners, who were distributed into the more-symptomatic (MSL, n = 7) and less-symptomatic (LSL, n = 7) groups according to the questionnaire participated in this study. The subjects ran at average speed 3.79 m·s–1 on the 5,8 m runway with four markers set on rearfoot and shank, and kinematics were determined using the motion analysis system with 6 and 8 cameras. For the rearfoot kinematics analysis the angles between calcaneus and shank in both legs were measured: angle at impact; maximum angle; the pronation amplitude; time from impact to maximum angle; time from maximum angle to toe-off supination. The pronation amplitude in the right foot was greater (p < 0.05) in MSL compared to LSL group (5.5º and 8.2º, respectively; p = 0.02). The other measured parameters did not differ significantly between the groups. We concluded that the variations in rearfoot kinematics cannot be the reasons for causing the symptoms of overuse and their origin should be searched from training errors
Using spectral diversity and heterogeneity measures to map habitat mosaics: An example from the Classical Karst
Questions: Can we map complex habitat mosaics from remote-sensing data? In doing
this, are measures of spectral heterogeneity useful to improve image classification
performance? Which measures are the most important? How can multitemporal data
be integrated in a robust framework?
Location: Classical Karst (NE Italy).
Methods: First, a habitat map was produced from field surveys. Then, a collection of
12 monthly Sentinel-2 images was retrieved. Vegetation and spectral heterogeneity
(SH) indices were computed and aggregated in four combinations: (1) monthly layers
of vegetation and SH indices; (2) seasonal layers of vegetation and SH indices; (3)
yearly layers of SH indices computed across the months; and (4) yearly layers of SH
indices computed across the seasons. For each combination, a Random Forest clas-
sification was performed, first with the complete set of input layers and then with a
subset obtained by recursive feature elimination. Training and validation points were
independently extracted from field data.
Results: The maximum overall accuracy (0.72) was achieved by using seasonally ag-
gregated vegetation and SH indices, after the number of vegetation types was re-
duced by aggregation from 26 to 11. The use of SH measures significantly increased
the overall accuracy of the classification. The spectral β-diversity was the most im-
portant variable in most cases, while the spectral α-diversity and Rao's Q had a low
relative importance, possibly because some habitat patches were small compared to
the window used to compute the indices.
Conclusions: The results are promising and suggest that image classification frame-
works could benefit from the inclusion of SH measures, rarely included before. Habitat
mapping in complex landscapes can thus be improved in a cost-and time-effective
way, suitable for monitoring applications
Delayed Capital Injections for a Risk Process with Markovian Arrivals
In this paper we propose a generalisation to the Markov Arrival Process (MAP) risk model, by allowing for a delayed receipt of required capital injections whenever the surplus of an insurance firm is negative. Delayed capital injections often appear in practice due to the time taken for administrative and processing purposes of the funds from a third party or the shareholders of a firm. We introduce a MAP risk model that allows for capital injections to be received instantaneously, or with a random delay, depending on the amount of deficit experienced by the firm. For this model, we derive a system of Fredholm integral equations of the second kind for the Gerber-Shiu function and obtain an explicit expression (in matrix form) in terms of the Gerber-Shiu function of the MAP risk model without capital injections. In addition, we show that the expected discounted accumulated capital injections and the expected discounted overall time in red, up to the time of ruin, satisfy a similar integral equation, which can also be solved explicitly. Finally, to illustrate the applicability of our results, numerical examples are given
The matrix metalloproteinase inhibitor marimastat promotes neural progenitor cell differentiation into neurons by gelatinase-independent TIMP-2-dependent mechanisms.
Metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs), produced in the brain by cells of non-neural and neural origin, including neural progenitors (NPs), are emerging as regulators of nervous system development and adult brain functions. In the present study, we explored whether MMP-2, MMP-9, and TIMP-2, abundantly produced in the brain, modulate NP developmental properties. We found that treatment of NPs, isolated from the murine fetal cerebral cortex or adult subventricular zone, with the clinically tested broad-spectrum MMP inhibitor Marimastat profoundly affected the NP differentiation fate. Marimastat treatment allowed for an enrichment of our cultures in neuronal cells, inducing NPs to generate higher percentage of neurons and a lower percentage of astrocytes, possibly affecting NP commitment. Consistently with its proneurogenic effect, Marimastat early downregulated the expression of Notch target genes, such as Hes1 and Hes5. MMP-2 and MMP-9 profiling on proliferating and differentiating NPs revealed that MMP-9 was not expressed under these conditions, whereas MMP-2 increased in the medium as pro-MMP-2 (72 kDa) during differentiation; its active form (62 kDa) was not detectable by gel zymography. MMP-2 silencing or administration of recombinant active MMP-2 demonstrated that MMP-2 does not affect NP neuronal differentiation, nor it is involved in the Marimastat proneurogenic effect. We also found that TIMP-2 is expressed in NPs and increases during late differentiation, mainly as a consequence of astrocyte generation. Endogenous TIMP-2 did not modulate NP neurogenic potential; however, the proneurogenic action of Marimastat was mediated by TIMP-2, as demonstrated by silencing experiments. In conclusion, our data exclude a major involvement of MMP-2 and MMP-9 in the regulation of basal NP differentiation, but highlight the ability of TIMP-2 to act as key effector of the proneurogenic response to an inducing stimulus such as Marimastat
NAADP-Dependent Ca2+ Signaling Controls Melanoma Progression, Metastatic Dissemination and Neoangiogenesis
A novel transduction pathway for the powerful angiogenic factor VEGF has been recently shown in endothelial cells to operate through NAADP-controlled intracellular release of Ca(2+). In the present report the possible involvement of NAADP-controlled Ca(2+) signaling in tumor vascularization, growth and metastatic dissemination was investigated in a murine model of VEGF-secreting melanoma. Mice implanted with B16 melanoma cells were treated with NAADP inhibitor Ned-19 every second day for 4 weeks and tumor growth, vascularization and metastatization were evaluated. Control specimens developed well vascularized tumors and lung metastases, whereas in Ned-19-treated mice tumor growth and vascularization as well as lung metastases were strongly inhibited. In vitro experiments showed that Ned-19 treatment controls the growth of B16 cells in vitro, their migratory ability, adhesive properties and VEGFR2 expression, indicating NAADP involvement in intercellular autocrine signaling. To this regard, Ca(2+) imaging experiments showed that the response of B16 cells to VEGF stimulation is NAADP-dependent. The whole of these observations indicate that NAADP-controlled Ca(2+) signaling can be relevant not only for neoangiogenesis but also for direct control of tumor cells
Mode of Collection Does Not Influence Haematopoietic Content of Umbilical Cord Blood Units from Caesarean Deliveries
Association between habitual physical activity and parameters of physical fitness in postmenopausal women
Designing food structure to control stability, digestion, release and absorption of lipophilic food components
The bioavailability of dietary lipophilic components may be either increased or decreased by manipulating the microstructure and/or physicochemical properties of the foods that contain them. This article stresses how knowledge of the molecular, physicochemical, and physiological processes that occur during lipid ingestion, digestion, and absorption can be used to rationally design food structures to control these processes and therefore impact the rate or extent of lipid digestion and/or absorption. These approaches include controlling the molecular characteristics of the lipid molecules, altering lipid droplet size or interfacial properties, and manipulating food matrix structure and composition. Improved knowledge of the molecular, physicochemical, and physiological processes that occur during lipid ingestion, digestion, and absorption will facilitate the rational design and fabrication of functional foods for improved health and wellness