9,114 research outputs found
Spectral and spatial information from a novel dual-wavelength full-waveform terrestrial laser scanner for forest ecology
The Salford Advanced Laser Canopy Analyser (SALCA) is an experimental terrestrial laser scanner designed and built specifically to measure the structural and biophysical properties of forest canopies. SALCA is a pulsed dual-wavelength instrument with co-aligned laser beams recording backscattered energy at 1063 and 1545 nm; it records full-waveform data by sampling the backscattered energy at 1 GHz giving a range resolution of 150 mm. The finest angular sampling resolution is 1 mrad and around 9 million waveforms are recorded over a hemisphere above the tripod-mounted scanner in around 110 minutes. Starting in 2010, data pre-processing and calibration approaches, data analysis, and information extraction methods, were developed and a wide range of field experiments conducted. The overall objective is to exploit the spatial, spectral and temporal characteristics of the data to produce ecologically useful information on forest and woodland canopies including leaf area index, plant area volume density and leaf biomass, and to explore the potential for tree species identification and classification. This paper outlines the key challenges in instrument development, highlights the potential applications for providing new data for forest ecology, and describes new avenues for exploring information-rich data from the next generation of TLS instruments like SALCA
Effect of paternal education about complementary feeding of infants in Kisumu county, Kenya
Improved health of infants is dependent on the supportive role of the fathers. There is limited research done in Kenya on father involvement and how it affects feeding practices of the infant. The objective of this study was to evaluate the impact on complementary feeding practice of nutrition education targeted to the father. A randomized control trial was conducted with 290 father-mother pairs recruited into the study. The mothers, who were six months pregnant and receiving antenatal services at Kisumu County Hospital, provided the contact point for recruitment of the fathers who were engaged in this study. The consenting mothers provided information of the ‘expectant father’ who were later contacted and invited to go to the hospital together with the mother. Consent was obtained from the study participants in a written form. Randomization was done to the father-mother pairs and eventually, each group had 145 pairs. The pairs in the intervention group were educated on complementary feeding while the other pairs in the control group did not get any intervention. Post-natal, feeding on solids and semi-solids of the infants were assessed at six months and at nine months of age. Qualitative assessment through focus group discussions were done to obtain information on fathers’ support towards complementary feeding. Overall analysis was done on 278 pairs with 12 lost to follow up. Introduction to solids and semi-solids had been done by a majority (96.7%) by six months of the infant’s age in both groups. Solid and semi-solid foods were introduced significantly earlier in the control group and compared to the intervention group (chi-square test; p<0.01). Minimum acceptable diet was significantly higher in the intervention group than the control group (chi-square test; p<0.01). In conclusion, giving fathers information on complementary feeding influences their support towards infant feeding, resulting in positive outcomes in complementary feeding practices.Key words: Father, Involvement, Infant, Complementary feeding, Nutrition Education, Kisumu, Keny
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Patient-derived iPSCs show premature neural differentiation and neuron type-specific phenotypes relevant to neurodevelopment.
Ras/MAPK pathway signaling is a major participant in neurodevelopment, and evidence suggests that BRAF, a key Ras signal mediator, influences human behavior. We studied the role of the mutation BRAFQ257R, the most common cause of cardiofaciocutaneous syndrome (CFC), in an induced pluripotent stem cell (iPSC)-derived model of human neurodevelopment. In iPSC-derived neuronal cultures from CFC subjects, we observed decreased p-AKT and p-ERK1/2 compared to controls, as well as a depleted neural progenitor pool and rapid neuronal maturation. Pharmacological PI3K/AKT pathway manipulation recapitulated cellular phenotypes in control cells and attenuated them in CFC cells. CFC cultures displayed altered cellular subtype ratios and increased intrinsic excitability. Moreover, in CFC cells, Ras/MAPK pathway activation and morphological abnormalities exhibited cell subtype-specific differences. Our results highlight the importance of exploring specific cellular subtypes and of using iPSC models to reveal relevant human-specific neurodevelopmental events
Intracellular trafficking and cellular uptake mechanism of PHBV nanoparticles for targeted delivery in epithelial cell lines
Indexación: Web of Science; Scopus; Scielo.Background: Nanotechnology is a science that involves imaging, measurement, modeling and a manipulation of matter at the nanometric scale. One application of this technology is drug delivery systems based on nanoparticles obtained from natural or synthetic sources. An example of these systems is synthetized from poly(3-hydroxybutyrate-co-3-hydroxyvalerate), which is a biodegradable, biocompatible and a low production cost polymer. The aim of this work was to investigate the uptake mechanism of PHBV nanoparticles in two different epithelial cell lines (HeLa and SKOV-3).
Results: As a first step, we characterized size, shape and surface charge of nanoparticles using dynamic light scattering and transmission electron microscopy. Intracellular incorporation was evaluated through flow cytometry and fluorescence microscopy using intracellular markers. We concluded that cellular uptake mechanism is carried out in a time, concentration and energy dependent way. Our results showed that nanoparticle uptake displays a cell-specific pattern, since we have observed different colocalization in two different cell lines. In HeLa (Cervical cancer cells) this process may occur via classical endocytosis pathway and some internalization via caveolin-dependent was also observed, whereas in SKOV-3 (Ovarian cancer cells) these patterns were not observed. Rearrangement of actin filaments showed differential nanoparticle internalization patterns for HeLa and SKOV-3. Additionally, final fate of nanoparticles was also determined, showing that in both cell lines, nanoparticles ended up in lysosomes but at different times, where they are finally degraded, thereby releasing their contents.
Conclusions: Our results, provide novel insight about PHBV nanoparticles internalization suggesting that for develop a proper drug delivery system is critical understand the uptake mechanism.https://jnanobiotechnology.biomedcentral.com/articles/10.1186/s12951-016-0241-
Melatonin in wake-sleep disorders in children, adolescents and young adults with mental retardation with or without epilepsy: a double-blind, cross-over, placebo-controlled trial
The aim of the present study was to verify the clinical efficacy of melatonin (MLT) in children, adolescents and young adults with wake–
sleep disorder and mental retardation, most of them on chronic anticonvulsant therapy for epileptic seizures, by means of a randomized,
double-blind, placebo-controlled cross-over trial. Twenty-five patients (16 males, nine females), aged from 3.6 to 26 years (mean 10.5 years),
all affected with mental retardation mostly with epileptic seizures, were randomized to oral synthetic fast-release MLT or placebo. Melatonin
was initiated at the daily dose of 3 mg, at nocturnal bedtime. In case of inefficacy, MLT dose could be titrated up to 9 mg the following
2 weeks at increments of 3 mg/week, unless the patient was unable to tolerate it. The analysis of all the sleep logs disclosed a significant
treatment effect of melatonin on sleep latency (P ¼ 0:019). Melatonin was well tolerated in all patients and no side effects were reported. In
conclusion, our study supports the efficacy of MLT in young patients with mental disabilities and epileptic seizures in improving the wake–
sleep disorders such as time to fall asleep. Overall, MLT appeared to influence the seizure frequency poorly, though there may be occasional
seizure worsening or improving. Such a dual effect requires further studies in young epileptic patients
Non-intersecting leaf insertion algorithm for tree structure models
We present an algorithm and an implementation to insert broadleaves or needleleaves to a quantitative structure model according to an arbitrary distribution, and a data structure to store the required information efficiently. A structure model contains the geometry and branching structure of a tree. The purpose of the work is to offer a tool for making more realistic simulations with tree models with leaves, particularly for tree models developed from terrestrial laser scan (TLS) measurements. We demonstrate leaf insertion using cylinder-based structure models, but the associated software implementation is written in a way that enables the easy use of other types of structure models. Distributions controlling leaf location, size and angles as well as the shape of individual leaves are user-definable, allowing any type of distribution. The leaf generation process consist of two stages, the first of which generates individual leaf geometry following the input distributions, while in the other stage intersections are prevented by doing transformations when required. Initial testing was carried out on English oak trees to demonstrate the approach and to assess the required computational resources. Depending on the size and complexity of the tree, leaf generation takes between 6 and 18 minutes. Various leaf area density distributions were defined, and the resulting leaf covers were compared to manual leaf harvesting measurements. The results are not conclusive, but they show great potential for the method. In the future, if our method is demonstrated to work well for TLS data from multiple tree types, the approach is likely to be very useful for 3D structure and radiative transfer simulation applications, including remote sensing, ecology and forestry, among others
Teleagro: software architecture of georeferencing and detection of heat of cattle
The systems of livestock production contribute in a preponderant way to improve the quality of life of the communities, since it allows to support the production of the daily sustenance of the communities, to conserve the
ecosystems, to promote the conservation of the wild life and to satisfy the values and traditions cultural Latin America, with its large wilderness areas, and a privileged climate favors the maintenance of livestock, to meet the demands of food and ensure regional and global food security. In Colombia, the agricultural sector contributes approximately 11.83% of the national GDP at current prices, according to the Bank of the Republic. Likewise, the livestock industry participates with 3.6%, in comparison with other sectors of the agricultural economy, the production of Colombian cattle doubles and triples to other sectors, such as poultry, coffee and floriculture. In addition, it contributes to the generation of employment in more than 25% of the total jobs generated in the agricultural sector and approximately 7% of the total employment of the Colombian economy (http://www.banrep.gov.co/is/pib). Within agricultural production, livestock occupy 38 million hectares, being 9 times larger than the area dedicated to agriculture. However, agriculture contributes 63% of the value of agricultural production, while livestock, mainly extensive, contributes 26% (FEDEGAN, Strategic Livestock Plan 2019). The large proportion of the área with agricultural vocation dedicated to precarious extensive livestock has
explained the low agricultural productivity in Colombia, with very serious consequences for human and sustainable development. This document shows the results of the communications, software and hardware platforms to help the livestock sector to manage production
Vitamin D in cancer chemoprevention
Context: There is increasing evidence that Vitamin D (Vit D) and its metabolites, besides their well-known calcium-related functions, may also exert antiproliferative, pro-differentiating, and immune modulatory effects on tumor cells in vitro and may also delay tumor growth in vivo.
Objective: The aim of this review is to provide fresh insight into the most recent advances on the role of Vit D and its analogues as chemopreventive drugs in cancer therapy.
Methods: A systematic review of experimental and clinical studies on Vit D and cancer was undertaken by using the major electronic health database including ISI Web of Science, Medline, PubMed, Scopus and Google Scholar.
Results and conclusion: Experimental and clinical observations suggest that Vit D and its analogues may be effective in preventing the malignant transformation and/or the progression of various types of human tumors including breast cancer, prostate cancer, colorectal cancer, and some hematological malignances. These findings suggest the possibility of the clinical use of these molecules as novel potential chemopreventive and anticancer agent
Comparison of clastogen-induced gene expression profiles in wild-type and DNA repair-deficient Rad54/Rad54B cells
Background: Previously we found that Rad54/Rad54B cells are more sensitive towards mitomycin C (MMC) as compared to wild-type (WT) cells. This difference in sensitivity was absent upon exposure to other clastogens like bleomycin (BLM) and g-radiation. In order to get further insight into possible underlying mechanisms, gene expression changes in WT and Rad54/Rad54B MEFs (mouse embryonic fibroblasts) after exposure to the clastogens MMC and BLM were investigated. Exposures of these cells to mutagens (N-ac-AAF and ENU) and vehicle were taken as controls. Results: Most exposures resulted in an induction of DNA damage signaling and apoptosis genes and a reduced expression of cell division genes in cells of both genotypes. As expected, responses to N-ac-AAF were very similar in both genotypes. ENU exposure did not lead to significant gene expression changes in cells of both genotypes, presumably due to its short half-life. Gene expression responses to clastogens, however, showed a genotype-dependent effect for BLM and MMC. MMC treated Rad54/Rad54B MEFs showed no induction of p53-signaling, DNA damage response and apoptosis as seen for all the other treatments. Conclusion: These data support our finding that different types of clastogens exist and that responses to these types depend on the DNA repair status of the cells.Toxicogenomics and risk assessmen
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