1,403 research outputs found
Application of artificial neural networks in sales forecasting
The aim of the work presented in this paper is to forecast sales volumes as accurately as possible and as far into the future as possible. The choice of network topology was Silva's adaptive backpropagation algorithm and the network architectures were selected by genetic algorithms (GAs). The networks were trained to forecast from 1 month to 6 months in advance and the performance of the network was tested after training. The test results of artificial neural networks (ANNs) are compared with the time series smoothing methods of forecasting using several measures of accuracy. The outcome of the comparison proved that the ANNs generally perform better than the time series smoothing methods of forecasting. Further recommendations resulting from this paper are presentedpublished_or_final_versio
Growth and endocrine disrupting effects of the mycotoxins zeralenone and aflatoxin B1 on breast cancer cells
Zearalenone (ZEA) and aflatoxin B1 (AFB1) are secondary metabolites produced by the fungi Fusarium and Aspergillus respectively. ZEA is proven to be an estrogenic endocrine disruptor since 1950s, while AFB1 is recently found to disrupt steroidogenesis in placenta. Both mycotoxins are constant contaminants of cereals worldwide and can both be found at significant levels in human plasma/urine of people in developing countries. Due to the co-occurrence of ZEA and AFB1 in food and human samples and the possibility of endocrine disruptors to modulate the growth of hormonal dependent breast cancer, we hypothesized that exposure to ZEA and AFB1 would affect the growth and cell cycle progression of breast cancer cells by modulating gene expressions and disrupting steroidogenesis and hormone …postprin
Learning curves for laparoscopic repair of inguinal hernia and communicating hydrocele in children
The Supplementary Material for this article can be found online at: http://journal.frontiersin.org/article/10.3389/fped.2017.00207/ full#supplementary-material.Introduction: We analyzed the department and surgeon learning curves during implementation of the percutaneous internal ring suturing (PIRS) technique in our department.
Methods: Children proposed for inguinal hernia or communicating hydrocele repair were included (n = 607). After mentorship, all surgeons were free to propose open or PIRS repair. From gathered data, we assessed department and surgeon learning curves through cumulative experience focusing in perioperative complications, conversion, ipsilateral recurrence, postoperative complications, and metachronous hernia, with benchmarks defined by open repair.
Results: Department-centered analysis revealed that perioperative complications, conversion, and ipsilateral recurrence rates were higher in the beginning, reaching the benchmarks when each surgeon performed, at least, 35 laparoscopic repairs. Postoperative complications and metachronous hernia rates were independent from learning curves, with the metachronous hernia rate being significantly lower in PIRS patients. During the program, the percentage of males in those operated by PIRS progressively increased reaching the percentage of males, in our sample, when department operated over 230 cases.
Conclusion: Thirty-five laparoscopic cases per surgeon are required for perioperative complications, conversion, and ipsilateral recurrence reach the benchmark. The gap between the percentage of males, in those operated by PIRS and in those proposed for surgery, monitors the confidence of the team in the program.This work was supported by the Fundação para a Ciência e Tecnologia (FCT), co-funded by Programa Operacional Regional do Norte (ON.2—O Novo 267 Norte); from the Quadro de Referência Estratégico Nacional (QREN) through the Fundo Europeu de Desenvolvimento Regional (FEDER) and from the Projeto Estratégico—LA 26—2013–2014 (PEst-C/SAU/ LA0026/2013).info:eu-repo/semantics/publishedVersio
Kasha or state selective behavior in the photochemistry of ortho-nitrobenzaldehyde?
The photochemistry of ortho-nitrobenzaldehyde dissolved in tetrahydrofuran was studied by means of femtosecond UV/Vis and IR spectroscopy. Comparison was made of the spectral and temporal signatures for similar to 400 nm and similar to 260 nm excitation. The 400 nm excitation promotes NBA to its lowest excited singlet state of n pi* character whereas for 260 nm an upper excited state of pi pi* character is addressed. On the picosecond time scale, the molecule undergoes hydrogen transfer, yielding a ketene intermediate, internal conversion recovering the starting material, and intersystem crossing. Time constants and yields of these processes are virtually not affected by the excitation wavelength. For 400 nm excitation a similar to 100 fs decay component seen in the 260 nm experiment is absent, indicating that this component is due to a pi pi* -> n pi* internal conversion. In contrast to its formation, the decay of the ketene intermediate is influenced by the excitation wavelength. This can be attributed to different amounts of vibrational excitation
Low Blood Lead Levels Do Not Appear to Be Further Reduced by Dietary Supplements
OBJECTIVE: Our objective was to evaluate the association of dietary intakes of selected micronutrients and blood lead (PbB) concentrations in female adults and in children. DESIGN: With longitudinal monitoring, we measured daily intakes of the micronutrients calcium, magnesium, sodium, potassium, barium, strontium, phosphorus, zinc, iron (limited data), and copper from 6-day duplicate diets (2–13 collections per individual) and PbB concentrations. Participants were three groups of females of child-bearing age (one cohort consisting of 21 pregnant subjects and 15 nonpregnant controls, a second cohort of nine pregnant migrants), and one group of 10 children 6–11 years of age. RESULTS: Mean PbB concentrations were < 5 μg/dL. A mixed linear model that included only group and time accounted for 5.9% of the variance of the PbB measurements; neither the effect of time nor the effect of group was significant. The model containing all of the micronutrients (except iron, for which there was a great deal of missing data), along with time and group, accounted for approximately 9.2% of the variance of PbB; this increase was not statistically significant. There was, however, a significant association of PbB with phosphorus, magnesium, and copper when all micronutrients were included in the statistical analysis, perhaps reflecting a synergistic effect. CONCLUSIONS: In contrast to most previous studies, we found no statistically significant relationships between the PbB concentrations and micronutrient intake. In adults and older children with low PbB concentrations and minimal exposure to Pb, micronutrient supplementation is probably unnecessary
A Case of Acute Myocardial Infarction with the Anomalous Origin of the Right Coronary Artery from the Ascending Aorta above the Left Sinus of Valsalva and Left Coronary Artery from the Posterior Sinus of Valsalva
Coronary anomalies are rare angiographic findings. Moreover, there are few reports of cases of an anomalous origin of the right coronary artery from the left sinus of Valsalva and of the left coronary artery from the posterior sinus of Valsalva. Here, we report a case with an anomalous origin of the right coronary artery from the ascending aorta above the left sinus of Valsalva and the left coronary artery from the posterior sinus of Valsalva. This was observed in a patient who was treated for a myocardial infarction of the inferior wall caused by a thrombus in the proximal right coronary artery. The patient was treated successfully with the implantation of a stent in the anomalous origin of the right coronary artery using a 6Fr Amplatz left 1 catheter
Fast, ultrasensitive detection of reactive oxygen species using a carbon nanotube based-electrocatalytic intracellular sensor
Herein, we report a highly sensitive electrocatalytic sensor-cell construct that can electrochemically communicate with the internal environment of immune cells (e.g., macrophages) via the selective monitoring of a particular reactive oxygen species (ROS), hydrogen peroxide. The sensor, which is based on vertically aligned single-walled carbon nanotubes functionalized with an osmium electrocatalyst, enabled the unprecedented detection of a local intracellular “pulse” of ROS on a short second time scale in response to bacterial endotoxin (lipopolysaccharide-LPS) stimulation. Our studies have shown that this initial pulse of ROS is dependent on NADPH oxidase (NOX) and toll like receptor 4 (TLR4). The results suggest that bacteria can induce a rapid intracellular pulse of ROS in macrophages that initiates the classical innate immune response of these cells to infection
The heparan sulfate proteoglycan syndecan-1 regulates colon cancer stem cell function via a focal adhesion kinase—Wnt signaling axis
In colon cancer, downregulation of the transmembrane heparan sulfate proteoglycan syndecan‐1 (Sdc‐1) is associated with increased invasiveness, metastasis, and dedifferentiation. As Sdc‐1 modulates signaling pathways relevant to stem cell function, we tested the hypothesis that it may regulate a tumor‐initiating cell phenotype. Sdc‐1 small‐interfering RNA knockdown in the human colon cancer cell lines Caco2 and HT‐29 resulted in an increased side population (SP), enhanced aldehyde dehydrogenase 1 activity, and higher expression of CD133, LGR5, EPCAM, NANOG, SRY (sex‐determining region Y)‐box 2, KLF2, and TCF4/TCF7L2. Sdc‐1 knockdown enhanced sphere formation, cell viability, Matrigel invasiveness, and epithelial‐to‐mesenchymal transition‐related gene expression. Sdc‐1‐depleted HT‐29 xenograft growth was increased compared to controls. Decreased Sdc‐1 expression was associated with an increased activation of β1‐integrins, focal adhesion kinase (FAK), and wingless‐type (Wnt) signaling. Pharmacological FAK and Wnt inhibition blocked the enhanced stem cell phenotype and invasive growth. Sequential flow cytometric SP enrichment substantially enhanced the stem cell phenotype of Sdc‐1‐depleted cells, which showed increased resistance to doxorubicin chemotherapy and irradiation. In conclusion, Sdc‐1 depletion cooperatively enhances activation of integrins and FAK, which then generates signals for increased invasiveness and cancer stem cell properties. Our findings may provide a novel concept to target a stemness‐associated signaling axis as a therapeutic strategy to reduce metastatic spread and cancer recurrence.DatabasesThe GEO accession number of the Affymetrix transcriptomic screening is GSE58751
B Physics at the Tevatron: Run II and Beyond
This report provides a comprehensive overview of the prospects for B physics
at the Tevatron. The work was carried out during a series of workshops starting
in September 1999. There were four working groups: 1) CP Violation, 2) Rare and
Semileptonic Decays, 3) Mixing and Lifetimes, 4) Production, Fragmentation and
Spectroscopy. The report also includes introductory chapters on theoretical and
experimental tools emphasizing aspects of B physics specific to hadron
colliders, as well as overviews of the CDF, D0, and BTeV detectors, and a
Summary.Comment: 583 pages. Further information on the workshops, including
transparencies, can be found at the workshop's homepage:
http://www-theory.lbl.gov/Brun2/. The report is also available in 2-up
http://www-theory.lbl.gov/Brun2/report/report2.ps.gz or chapter-by-chapter
http://www-theory.lbl.gov/Brun2/report
RhoA/ROCK-mediated switching between Cdc42- and Rac1-dependent protrusion in MTLn3 carcinoma cells
Rho GTPases are versatile regulators of cell shape that act on the actin cytoskeleton. Studies using Rho GTPase mutants have shown that, in some cells, Rac1 and Cdc42 regulate the formation of lamellipodia and filopodia, respectively at the leading edge, whereas RhoA mediates contraction at the rear of moving cells. However, recent reports have described a zone of RhoA/ROCK activation at the front of cells undergoing motility. In this study, we use a FRET-based RhoA biosensor to show that RhoA activation localizes to the leading edge of EGF-stimulated cells. Inhibition of Rho or ROCK enhanced protrusion, yet markedly inhibited cell motility; these changes correlated with a marked activation of Rac-1 at the cell edge. Surprisingly, whereas EGF-stimulated protrusion in control MTLn3 cells is Rac-independent and Cdc42-dependent, the opposite pattern is observed in MTLn3 cells after inhibition of ROCK. Thus, Rho and ROCK suppress Rac-1 activation at the leading edge, and inhibition of ROCK causes a switch between Cdc42 and Rac-1 as the dominant Rho GTPase driving protrusion in carcinoma cells. These data describe a novel role for Rho in coordinating signaling by Rac and Cdc42
- …