3,353 research outputs found
Image Management in a Touristic Destination: A Qualitative Approach Analysis of the Border City of Ciudad Juarez, Mexico
This paper summarizes an academic experience. It has been made by the contributions of a group of experts from a Mexican university participating in a discussion panel called "Image of a Touristic Destination". This was done within the framework of the activities carried out during the 8va. Catedra Patrimonial "Sergio Molina" on October 19-21, 2016. The purpose of this paper is to analyze the process of image management of a border touristic destination through the experience of Ciudad Juárez, in order to obtain an improvement in it. The concept of image is analyzed from its components of responsibility and participation in management between Government (message), Society (context), and Universities (management). The methodological approach selected was exploratory. The grounded theory method was selected and thematic analysis with the support of the Atlas-ti software was made. Suggestions are offered for actions which seek to highlight the positive aspects of the city as a touristic destination. The importance of generating responsibility and participation within a social network was highlighted. It was recommended to take advantage of the economic and intellectual resources in education of the Juarez society so that they can know their culture and history
Estimation of incoming global solar radiation and its diffuse component at the surface in Paraiba state (NE Brazil)
Results of a study on the estimation of mean monthly values of incoming global solar radiation and its diffuse component at some stations in Paraiba state (NE Brazil) are presented in this paper. Radiation data at four stations is used. ˚Angstr¨om-type equations are derived for the estimation of global radiation and the diffuse fraction of global radiation is expressed in terms of the clearness index and the sunshine ratio. The applicability of previously reported equations for stations in this region is investigated
Fgf-23 and vascular calcification in a peritoneal dialysis population with residual renal function
Introduction and Aims: Fibroblast growth factor 23 (FGF-23) induces phosphaturia. Its clinical impact is beyond mineral bone disease in chronic kidney disease (CKD), being coupled with vascular calcification and mortality. Residual renal function (RRF) is associated with significant capacity to excrete phosphate in peri- toneal dialysis (PD). Besides testing whether FGF-23 is still related with glomerular filtration rate (GFR) and phosphate excretion in this late stage of CKD (5d), we aimed to explore its link with vascular calcification.Subjects and Methods: FGF-23 (C terminal) was measured in forty prevalent PD patients with RRF, aged 61.5 (51.0-67.0) years old, in renal replacement therapy (RRT) for 43.5 (23-80.0) months; 36.6% were female, 19.5% had diabetes mellitus and 37.5% were under automated PD regimen; 80% were on PD first, and only 20% had previous RRT. Relevant variables including dietary phosphate (P) intake, CKD-bone laboratory parameters, serum 25-hydroxyvitamin D, magnesium (Mg) levels, GFR, urinary phosphate, fractional excretion of phosphorus (FEP), albumin, proBNP and Adragão vascular calcification score were explored. Results: Median levels (25-75% range) of serum variables were: FGF-23 1997 (1623-2149) RU/mL, Mg 0.94 (0.8-1.0) mmol/L, 25-hydroxyvitamin D 30 (18-47) nmol/L, calcium 2.2 (2.0-2.37) mmol/L, phosphorus 1.69 (1.30-1.90) mmol/L, PTH 429 (309-626) pg/mL. FGF-23 correlated positively with serum phosphate (r = 0.39, p = 0.013) and negatively with urine volume (r = -0.48, p = 0.001), phosphaturia (r = -0.594, p < 0.0001) and GFR (r =-0.61,p < 0.0001). However, FGF-23 was not significantly correlated with age, total time of RRT, dietary P, FEP, Mg, nor 25-hydroxyvitamin D. High FGF-23 group had higher FEP. GFR was the single inde- pendent predictor of increased FGF-23. On the other hand, neither FGF-23 nor low FEP/FGF-23 ratio were significantly associated with the vascular calcification score. Only albumin (lower), magnesium (lower) and proBNP (higher) levels significantly differed in calcified versus non-calcified patients (all with p < 0.05). Conclusions: In our population, FGF-23 was not associated with vascular calcification. GFR was the single independent predictor of increased FGF-23 in patients with diuresis. Increment of FGF-23 in PD patients signalizes an active endocrine phosphaturic process compensating renal function loss, as expressed by higher fractional excretion of phosphorus. It alerts for dietetic and therapy optimization. However, its link with vascular calcification still lacks validation
Photosynthetic Light Response of Tanzania Grass under Four Levels of Leaf Temperature
The purpose of this paper is to establish photosynthetic light response curves for Tanzania grass (Panicum maximum Jacq.) under four leaf temperature levels. Photosynthetic rate was measured as a response to levels of photosynthetic photon flux density (PPFD) on the youngest fully expanded leaves of 12 representative tillers with an infra red gas analyzer. The effect of PPFD was tested for each leaf temperature level in a randomized complete block design. Photosynthetic light response curves were adjusted for each leaf temperature using a non-linear hyperbolic model. The maximum photosynthetic response was 25,59; 31,43; 34,57 and 27,53 µmol CO2 m-2 s-1 for 25, 30, 35 and 40 oC of leaf temperature, respectively. Although light saturation was not attained, response to light increments declined with light levels higher than 1000 – 2000 µmol photon m-2 s-1, and the response curve approximated saturation slowly. Photosynthetic rates of Tanzania grass depend on light and temperature level and these must be considered when modelling crop yield potential
One-pot organocatalyzed synthesis of tricyclic indolizines
Indolizines and their saturated derivatives are important structural motifs present in several biologically active compounds of both natural and synthetic origin. We describe herein a one-pot approach for the synthesis of tricyclic indolizines catalyzed by a bicyclic imidazole-alcohol. The protocol is based on an aqueous Morita-Baylis-Hillman reaction between pyridine-2-carboxaldehydes and six- or seven-membered cyclic enones, followed by sequential intramolecular cyclization and dehydration. So, in a single operational step two new bonds (C-C and C-N) are formed in an organocatalyzed process that takes place in simple conditions (stirring in water at 60 °C for 12 h) and with great atom economy (water as the sole byproduct), affording the purified compounds in yields ranging from 19 to 70%. The facility of the cyclization strongly depends on the size of the cycloalkenone ring: while MBH adducts derived from six-, seven- or eight-membered cycloenones are readily transformed into the corresponding indolizines, cyclopentenone-derived MBH adducts do not cyclize. A competition experiment revealed that cycloheptenone- derived MBH adducts cyclize faster than cyclohexenone-derived adducts. Model DFT calculations have been performed to rationalize these reactivity trends
J-PLUS: A wide-field multi-band study of the M15 globular cluster. Evidence of multiple stellar populations in the RGB
The Javalambre Photometric Local Universe Survey (J-PLUS) provides wide
field-of-view images in 12 narrow, intermediate and broad-band filters
optimized for stellar photometry. Here we have applied J-PLUS data for the
first time for the study of Galactic GCs using science verification data
obtained for the very metal-poor GC M\,15. Our J-PLUS data provide
low-resolution spectral energy distributions covering the near-UV to the
near-IR, allowing us to search for MPs based on pseudo-spectral fitting
diagnostics. J-PLUS CMDs are found to be particularly useful to search for
splits in the sequences formed by the upper red giant branch (RGB) and
asymptotic giant branch (AGB) stars. We interpret these split sequences as
evidence for the presence of MPs. This demonstrates that the J-PLUS survey will
have sufficient spatial coverage and spectral resolution to perform a large
statistical study of GCs through multi-band photometry in the coming years.Comment: 11 pages, 11 figures. Accepted for publication @ A&
Novel hydroxyapatite/chitosan bilayered scaffold for osteochondral tissue-engineering applications : scaffold design and its performance when seeded with goat bone marrow stromal cells
Recent studies suggest that bone marrow stromal cells are a potential source of osteoblasts and chondrocytes and can be used to
regenerate damaged tissues using a tissue-engineering (TE) approach. However, these strategies require the use of an appropriate scaffold
architecture that can support the formation de novo of either bone and cartilage tissue, or both, as in the case of osteochondral defects.
The later has been attracting a great deal of attention since it is considered a difficult goal to achieve. This work consisted on developing
novel hydroxyapatite/chitosan (HA/CS) bilayered scaffold by combining a sintering and a freeze-drying technique, and aims to show the
potential of such type of scaffolds for being used in TE of osteochondral defects. The developed HA/CS bilayered scaffolds were
characterized by Fourier transform infra-red spectroscopy, X-ray diffraction analysis, micro-computed tomography, and scanning
electron microscopy (SEM). Additionally, the mechanical properties of HA/CS bilayered scaffolds were assessed under compression. In
vitro tests were also carried out, in order to study the water-uptake and weight loss profile of the HA/CS bilayered scaffolds. This was
done by means of soaking the scaffolds into a phosphate buffered saline for 1 up to 30 days. The intrinsic cytotoxicity of the HA scaffolds
and HA/CS bilayered scaffolds extract fluids was investigated by carrying out a cellular viability assay (MTS test) using Mouse
fibroblastic-like cells. Results have shown that materials do not exert any cytotoxic effect. Complementarily, in vitro (phase I) cell culture
studies were carried out to evaluate the capacity of HA and CS layers to separately, support the growth and differentiation of goat
marrow stromal cells (GBMCs) into osteoblasts and chondrocytes, respectively. Cell adhesion and morphology were analysed by SEM
while the cell viability and proliferation were assessed by MTS test and DNA quantification. The chondrogenic differentiation of
GBMCs was evaluated measuring the glucosaminoglycans synthesis. Data showed that GBMCs were able to adhere, proliferate and
osteogenic differentiation was evaluated by alkaline phosphatase activity and immunocytochemistry assays after 14 days in osteogenic
medium and into chondrocytes after 21 days in culture with chondrogenic medium. The obtained results concerning the physicochemical
and biological properties of the developed HA/CS bilayered scaffolds, show that these constructs exhibit great potential for their use in
TE strategies leading to the formation of adequate tissue substitutes for the regeneration of osteochondral defects
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