93 research outputs found
Robotic Visual Tracking of Relevant Cues in Underwater Environments with Poor Visibility Conditions
Using visual sensors for detecting regions of interest in underwater environments is fundamental for many robotic applications. Particularly, for an autonomous exploration task, an underwater vehicle must be guided towards features that are of interest. If the relevant features can be seen from the distance, then smooth control movements of the vehicle are feasible in order to position itself close enough with the final goal of gathering visual quality images. However, it is a challenging task for a robotic system to achieve stable tracking of the same regions since marine environments are unstructured and highly dynamic and usually have poor visibility. In this paper, a framework that robustly detects and tracks regions of interest in real time is presented. We use the chromatic channels of a perceptual uniform color space to detect relevant regions and adapt a visual attention scheme to underwater scenes. For the tracking, we associate with each relevant point superpixel descriptors which are invariant to changes in illumination and shape. The field experiment results have demonstrated that our approach is robust when tested on different visibility conditions and depths in underwater explorations
Equilibration of Concentrated Hard Sphere Fluids
We report a systematic molecular dynamics study of the isochoric
equilibration of hard-sphere fluids in their metastable regime close to the
glass transition. The thermalization process starts with the system prepared in
a non-equilibrium state with the desired final volume fraction {\phi} but with
a prescribed non-equilibrium static structure factor S_0(k; {\phi}). The
evolution of the {\alpha}- relaxation time {\tau}{\alpha} (k) and long-time
self-diffusion coefficient DL as a function of the evolution time tw is then
monitored for an array of volume fractions. For a given waiting time the plot
of {\tau}{\alpha} (k; {\phi}, tw) as a function of {\phi} exhibits two regimes
corresponding to samples that have fully equilibrated within this waiting time
({\phi} \leq {\phi}(c) (tw)), and to samples for which equilibration is not yet
complete ({\phi} \geq {\phi}(c) (tw)). The crossover volume fraction {\phi}(c)
(tw) increases with tw but seems to saturate to a value {\phi}(a) \equiv
{\phi}(c) (tw \rightarrow \infty) \approx 0.582. We also find that the waiting
time t^(eq)_w({\phi}) required to equilibrate a system grows faster than the
corresponding equilibrium relaxation time, t^(eq)({\phi}) \approx 0.27 \times
[{\tau}{\alpha} (k; {\phi})]^1.43, and that both characteristic times increase
strongly as {\phi} approaches {\phi}^(a), thus suggesting that the measurement
of equilibrium properties at and above {\phi}(a) is experimentally impossible
Amphibians and reptiles encountered during an expedition to Panama
Abstract.—During a recent expedition to five protected areas in Panama (Parque Nacional Volcán Barú andReserva Forestal Fortuna, Chiriquí Province; Parque Nacional Santa Fe, Veraguas Province; Parque Nacional Darien,Rancho Frío, Darien Province; and Mamoni Valley Private Reserve, Panama Province), we observed 95 species ofamphibians and reptiles (51 amphibians and 44 reptiles). We made opportunistic observations of many of them,including noteworthy updates on the conservation status of critically endangered or endangered taxa (Atelopus glyphus,A. limosus, A. varius, Isthmohyla angustilineata, I. tica, Oedipina grandis), the third and fourth distribution records forPanama of Trilepida macrolepis, the second distribution report of Leptophis cupreus for the country, the fourth countryrecord of Bachia blairi, new behavior and maximum size for Oophaga vicentei, and the second known specimen ofNorops triumphalis
Planeamiento estratégico para el sector ganadero de la Región Cajamarca
El objetivo del presente trabajo de investigación es la de elaborar un planeamiento
estratégico que permita al sector ganadero de la región Cajamarca pasar de una situación
actual a una situación futura deseada, su desarrollo esto basado considerando su potencial
ganadero, las condiciones de mercado existentes, en la disponibilidad de los diversos recursos
presentes en la región, así como el interés por parte del gobierno en el desarrollo del sector.
El desarrollo del plan estratégico ha considerado un análisis interno y externo que ha
permitido determinar un marco situacional con el cual se establecieron estrategias que
coadyuven al logro de objetivos de corto y largo plazo enfocados principalmente en el
desarrollo del sector.
Debe indicarse que la situación actual del sector presenta situaciones complejas como
el hecho de que la producción ganadera se encuentra atomizada, además de la fuerte
presencia de actividades contrarias como la minería, sin embargo el potencial e interés en
desarrollar a la región como zona ganadera se presenta como una oportunidad que permitirá
lograr desarrollo y bienestar para los diferentes grupos de interés.
Finalmente, la situación presenta un escenario favorable para la implementación de
medidas que permitan impulsar el desarrollo del sector, la mejoría en los procesos de
producción, su posicionamiento en el mercado local, las alternativas de expansión a mercados
de la región, la implementación de estándares internacionales en su cadena productiva y de
comercialización serán la base para concretar el desarrollo, con todo ello se impulsará la
intervención de sus principales actores, normalizando y regulando la operación de
productores informales con el fin de incorporarlos a una propuesta de desarrollo conjunta de
la regiónThe objective of this research is to develop a strategic planning that allows the
livestock sector in the Cajamarca region move from a current state to a desired future state,
its development this based considering its livestock potential, existing market conditions, in
the availability of various resources in the region, as well as interest from the government in
developing the sector.
The development of the strategic plan has considered an internal and external
analysis, it has identified a situational framework with which strategies that contribute to
achieving short-term and long-term focused primarily on the development of the sector.
It should be noted that the current situation of the sector presents complex situations
such as the fact that livestock production is atomized, in addition to the strong presence of
contrary activities such as mining, however the potential and interest in developing the region
as livestock area, It presents an opportunity that will achieve development and prosperity for
the different stakeholders.
Finally, the situation is favorable for the implementation of measures to boost the
sector's development, improved production processes, its position in the local market,
alternative expansion to markets in the region, the implementation of standards international
in their production and marketing chain will be the basis for concrete development, with all
the intervention of the main actors it will be promoted, standardizing and regulating the
operation of informal producers in order to incorporate them into a development proposal
jointly in the regionTesi
Mast Cell Changes the Phenotype of Microglia via Histamine and ATP
Background/Aims: Microglia are the dynamic motile phagocytes of the brain considered
the first line of defense against threats or disturbances to the Central Nervous System
(CNS). Microglia help orchestrate the immunological response by interacting with others
immune cells. Mast cells (MCs) are effector cells of the innate immune system distributed
in all organs and vascularized tissues, brain included. Several molecular mechanisms for
potential interactions between MCs and microglia have been determined. However, the
effect of MCs on regulated exocytosis and phagocytic clearance in microglia has not been
explored. Methods: Cocktails of MCs mediators (MCM) obtained at 37°C and 53°C were used
to induce microglia activation. Changes in intracellular calcium [Ca2+]i and ATP release were
studied by calcium and quinacrine fluorescence imaging. Fluorescent latex beads were used
to assay phagocytosis in microglia after MCM treatment and compared to that measured
in the presence of histamine, ATP and lipopolysaccharide (LPS). Iba-1 expression and area
were quantified by immunofluorescence and histamine levels evaluated by ELISA techniques.
Results: Local application onto microglia of the MC mediator cocktail elicited Ca2+ transients
and exocytotic release associated with quinacrine dye de-staining. Ca2+ signals were mimicked
by histamine and blocked by the H1 receptor (H1R) antagonist, cetirizine. Hydrolysis of ATP
by apyrase also affected Ca2+ transients to a lesser extent. Iba-1 fluorescence, cell area and
phagocytosis were enhanced by histamine through H1R. However, ATP prevented iba-1
expression and microglial phagocytosis. MCM showed combined effects of histamine and
ATP, increasing the number of internalized microbeads per cell and area without raising iba1
expression. Conclusion: Our results highlight the relevance of MC-derived histamine and ATP
in the modulation of secretory and phagocytic activities that would explain the heterogeneity
of microglial responses in different pathological contexts.Agencia Estatal de Investigación/ProyectoJunta de Andalucí
Associations of dietary energy density with body composition and cardiometabolic risk in children with overweight and obesity: role of energy density calculations, under-reporting energy intake and physical activity
This study examined (1) the association of dietary energy density from solid (EDS) and solid plus liquids (EDSL) with adiposity and cardiometabolic risk factors (CRF) in children with overweight and obesity, (2) the effect of under-reporting on the mentioned associations and (3) whether the association between ED and body composition and CRF is influenced by levels of physical activity. In a cross-sectional design, 208 overweight and obese children (8-12-year-old; 111 boys) completed two non-consecutive 24 h recalls. ED was calculated using two different approaches: EDS and EDSL. Under-reporters were determined with the Goldberg method. Body composition, anthropometry and fasting blood sample measurements were performed. Moderate to vigorous physical activity (MVPA) was registered with accelerometers (7-d-register). Linear regressions were performed to evaluate the association of ED with the previously mentioned variables. Neither EDS nor EDSL were associated with body composition or CRF. However, when under-reporters were excluded, EDS was positively associated with BMI (P=0 019), body fat percentage (P=0 005), abdominal fat (P=0 008) and fat mass index (P=0 018), while EDSL was positively associated with body fat percentage (P=0 008) and fat mass index (P=0 026). When stratifying the group according to physical activity recommendations, the aforementioned associations were only maintained for non-compliers. Cluster analysis showed that the low-ED and high-MVPA group presented the healthiest profile for all adiposity and CRF. These findings could partly explain inconsistencies in literature, as we found that different ED calculations entail distinct results. Physical activity levels and excluding under-reporters greatly influence the associations between ED and adiposity in children with overweight and obesity.The research leading to these results has received funding from la Caixa Foundation and Triptolemos Foundation, the Ministry of Health (FIS PI081297), the Research Network on Preventative Activities and Health Promotion (RD06/0018/ 0038), the Henning and Johan Throne-Holst Foundation (F. B. O.), the Spanish Ministry of Education, Culture and Sport (FPU14/03329 to M. M.), the Spanish Ministry of Economy and Competitiveness (DEP2013-47540 and DEP2016-78377-R; BES-2014-068829 to C. C.-S.), Fondo de Investigacion Sanitaria del Instituto de Salud Carlos III (PI13/01335), Fondos Estructurales de la Union Europea (FEDER), Una manera de hacer Europa, the Spanish Ministry of Science and Innovation (RYC-2011-09011 to F. B. O.), the University of Granada, Plan Propio de Investigacion 2016, Excellence Actions: Units of Excellence, Unit of Excellence on Exercise and Health (UCEES), Programa de Captacion de Talento - UGR Fellows (L. G.-M.), the SAMID III network, RETICS (PN I +D+ I 2017-2021). This study has been partially funded by the University of Granada, Plan Propio de Investigacion 2016, Excellence actions: Units of Excellence; Unit of Excellence on Exercise and Health (UCEES), and by the Junta de Andalucia, Consejeria de Conocimiento, Investigacion y Universidades and European Regional Development Fund (ERDF), reference SOMM17/6107/UGR. ISCIII-Sub-Directorate General for Research Assessment and Promotion, the European Regional Development Fund (RD16/ 0022), the EXERNET Research Network on Exercise and Health in Special Populations (DEP2005-00046/ACTI), and the University of the Basque Country (GIU14/21). J. M.-G. is supported by the Spanish Ministry of Education, Culture and Sport (FPU14/06837). J. H. M. is supported by the Spanish Ministry of Education, Culture and Sport (FPU15/02645)
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