737 research outputs found
Bayesian Model Search for Nonstationary Periodic Time Series
We propose a novel Bayesian methodology for analyzing nonstationary time
series that exhibit oscillatory behaviour. We approximate the time series using
a piecewise oscillatory model with unknown periodicities, where our goal is to
estimate the change-points while simultaneously identifying the potentially
changing periodicities in the data. Our proposed methodology is based on a
trans-dimensional Markov chain Monte Carlo (MCMC) algorithm that simultaneously
updates the change-points and the periodicities relevant to any segment between
them. We show that the proposed methodology successfully identifies time
changing oscillatory behaviour in two applications which are relevant to
e-Health and sleep research, namely the occurrence of ultradian oscillations in
human skin temperature during the time of night rest, and the detection of
instances of sleep apnea in plethysmographic respiratory traces.Comment: Received 23 Oct 2018, Accepted 12 May 201
The Effects of Altitude on the Profitability, Productivity, and Technical Efficiency of Cacao Farms in Calinan and Marilog Districts, Davao City, Philippines
Altitude is one of many components that accounts for climatic variability, which affects the level of inputs and outputs of farmers. This study compared the profitability and technical efficiency of cacao farms situated in areas classified as low, medium, and high altitude in Calinan and Marilog Districts, Davao City, Philippines. Costs and returns were calculated across wet, dried, and mixed cacao bean classification following the Philippine Statistics Authority template. The results suggest that dried cacao bean production in low, medium, and high altitudes have positive but smaller net returns relative to wet cacao bean production in low and medium altitudes and mixed cacao bean production in medium altitude. Dried cacao beans from these areas were marginally less profitable compared to wet beans primarily due to low quality of dried beans as a result of limited drying facilities. The stochastic production function was also used to determine technical efficiency performance. Cost of chemical inputs is a positive and significant factor of production. Farms with high altitude were less technically efficient compared to farms with low and medium altitudes. Higher altitude entails lower temperature and humidity, and cacao farming can be more challenging under this condition. Also, input purchasing behavior of farmers is also affected as the cost of transport becomes expensive. Access to extension, modern technology, and postharvest facilities is also limited in high altitude regions. However, there is an opportunity for farmers in high altitudes to improve their profitability by focusing on producing quality products and accessing specialty market
Plasma Factor XIII Activity in Patients with Disseminated Intravascular Coagulation
The objective of this study was to investigate the correlation between factor XIII (FXIII) activity and disseminated intravascular coagulation (DIC) parameters and also to evaluate the clinical usefulness of DIC diagnosis. Citrated plasma from eighty patients with potential DIC was analyzed for FXIII activity. The primary patient conditions (48 male and 32 female, mean age, 51 years) were malignancy (n = 29), infection (n = 25), inflammation (n = 6), heart disease (n = 3), thrombosis (n = 2), injury (n = 2), and other miscellaneous conditions (n = 13). FXIII testing was performed using the CoaLinkTM FXIII Incorporation Assay Kit (PeopleBio Inc.). Among 80 patients who were suspected to have DIC based on clinical analysis, 46 (57.5%) fulfilled the overt DIC criteria (DIC score > = 5) according to the International Society of Thrombosis and Haemostasis. FXIII levels in the plasma were significantly decreased in overt DIC compared to non-overt DIC patients (mean 75.1% and 199.7% respectively, p < 0.0001). Interestingly, we found a significant inverse correlation between DIC scores and FXIII activity. In addition, FXIII activity significantly correlated with other hemostatic markers that included platelet count, prothrombin time, activated partial thromboplastin time, fibrinogen, and D-dimer. FXIII levels were significantly lower in patients with liver or renal dysfunction. In conclusion, FXIII cross-linking activity measurements may have differential diagnostic value as well as predictive value in patients who are suspected to have DIC
Diurnal changes in capecitabine clock-controlled metabolism enzymes are responsible for its pharmacokinetics in male mice
The circadian timing system controls absorption, distribution, metabolism, and elimination processes of drug pharmacokinetics over a 24-h period. Exposure of target tissues to the active form of the drug and cytotoxicity display variations depending on the chronopharmacokinetics. For anticancer drugs with narrow therapeutic ranges and dose-limiting side effects, it is particularly important to know the temporal changes in pharmacokinetics. A previous study indicated that pharmacokinetic profile of capecitabine was different depending on dosing time in rat. However, it is not known how such difference is attributed with respect to diurnal rhythm. Therefore, in this study, we evaluated capecitabine-metabolizing enzymes in a diurnal rhythm-dependent manner. To this end, C57BL/6J male mice were orally treated with 500 mg/kg capecitabine at ZT1, ZT7, ZT13, or ZT19. We then determined pharmacokinetics of capecitabine and its metabolites, 5 '-deoxy-5-fluorocytidine (5 ' DFCR), 5 '-deoxy-5-fluorouridine (5 ' DFUR), 5-fluorouracil (5-FU), in plasma and liver. Results revealed that plasma C-max and AUC(0-6h) (area under the plasma concentration-time curve from 0 to 6 h) values of capecitabine, 5 ' DFUR, and 5-FU were higher during the rest phase (ZT1 and ZT7) than the activity phase (ZT13 and ZT19) (p < 0.05). Similarly, C-max and AUC(0-6h) values of 5 ' DFUR and 5-FU in liver were higher during the rest phase than activity phase (p < 0.05), while there was no significant difference in liver concentrations of capecitabine and 5 ' DFCR. We determined the level of the enzymes responsible for the conversion of capecitabine and its metabolites at each ZT. Results indicated the levels of carboxylesterase 1 and 2, cytidine deaminase, uridine phosphorylase 2, and dihydropyrimidine dehydrogenase (p < 0.05) are being rhythmically regulated and, in turn, attributed different pharmacokinetics profiles of capecitabine and its metabolism. This study highlights the importance of capecitabine administration time to increase the efficacy with minimum adverse effects.Istanbul Universit
Genotyping Cancer-Associated Genes in Chordoma Identifies Mutations in Oncogenes and Areas of Chromosomal Loss Involving CDKN2A, PTEN, and SMARCB1
The molecular mechanisms underlying chordoma pathogenesis are unknown. We therefore sought to identify novel mutations to better understand chordoma biology and to potentially identify therapeutic targets. Given the relatively high costs of whole genome sequencing, we performed a focused genetic analysis using matrix-assisted laser desorption/ionization-time of flight mass spectrometer (Sequenom iPLEX genotyping). We tested 865 hotspot mutations in 111 oncogenes and selected tumor suppressor genes (OncoMap v. 3.0) of 45 human chordoma tumor samples. Of the analyzed samples, seven were identified with at least one mutation. Six of these were from fresh frozen samples, and one was from a paraffin embedded sample. These observations were validated using an independent platform using homogeneous mass extend MALDI-TOF (Sequenom hME Genotyping). These genetic alterations include: ALK (A877S), CTNNB1 (T41A), NRAS (Q61R), PIK3CA (E545K), PTEN (R130), CDKN2A (R58*), and SMARCB1 (R40*). This study reports on the largest comprehensive mutational analysis of chordomas performed to date. To focus on mutations that have the greatest chance of clinical relevance, we tested only oncogenes and tumor suppressor genes that have been previously implicated in the tumorigenesis of more common malignancies. We identified rare genetic changes that may have functional significance to the underlying biology and potential therapeutics for chordomas. Mutations in CDKN2A and PTEN occurred in areas of chromosomal copy loss. When this data is paired with the studies showing 18 of 21 chordoma samples displaying copy loss at the locus for CDKN2A, 17 of 21 chordoma samples displaying copy loss at PTEN, and 3 of 4 chordoma samples displaying deletion at the SMARCB1 locus, we can infer that a loss of heterozygosity at these three loci may play a significant role in chordoma pathogenesis
Stream drying drives microbial ammonia oxidation and first-flush nitrate export
Acknowledgments We thank Roser Ventosa for technical assistance at the Nutrient Analytical Service of the CEAB-CSIC, Unai Perez de Arenaza Basauri for field assistance and Iñaki Odriozola and Aitor Larrañaga for statistical advice. We also acknowledge two anonymous reviewers for valuable feedback and constructive comments on the manuscript. S. N. Merbt was supported by a JAE predoctoral fellowship from the Spanish National Research Council (CSIC). This research was granted by the projects DARKNESS (CGL2012-32747, MINECO) to E. O. Casamayor and MED_FORESTREAM (CGL2011-30590-CO2-02, MINECO) and REFRESH (244121 FP7 EU Commission) to E. Martí.Peer reviewedPostprin
Egr3 Dependent Sympathetic Target Tissue Innervation in the Absence of Neuron Death
Nerve Growth Factor (NGF) is a target tissue derived neurotrophin required for normal sympathetic neuron survival and target tissue innervation. NGF signaling regulates gene expression in sympathetic neurons, which in turn mediates critical aspects of neuron survival, axon extension and terminal axon branching during sympathetic nervous system (SNS) development. Egr3 is a transcription factor regulated by NGF signaling in sympathetic neurons that is essential for normal SNS development. Germline Egr3-deficient mice have physiologic dysautonomia characterized by apoptotic sympathetic neuron death and abnormal innervation to many target tissues. The extent to which sympathetic innervation abnormalities in the absence of Egr3 is caused by altered innervation or by neuron death during development is unknown. Using Bax-deficient mice to abrogate apoptotic sympathetic neuron death in vivo, we show that Egr3 has an essential role in target tissue innervation in the absence of neuron death. Sympathetic target tissue innervation is abnormal in many target tissues in the absence of neuron death, and like NGF, Egr3 also appears to effect target tissue innervation heterogeneously. In some tissues, such as heart, spleen, bowel, kidney, pineal gland and the eye, Egr3 is essential for normal innervation, whereas in other tissues such as lung, stomach, pancreas and liver, Egr3 appears to have little role in innervation. Moreover, in salivary glands and heart, two tissues where Egr3 has an essential role in sympathetic innervation, NGF and NT-3 are expressed normally in the absence of Egr3 indicating that abnormal target tissue innervation is not due to deregulation of these neurotrophins in target tissues. Taken together, these results clearly demonstrate a role for Egr3 in mediating sympathetic target tissue innervation that is independent of neuron survival or neurotrophin deregulation
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Inflation and Dark Energy from spectroscopy at z > 2
The expansion of the Universe is understood to have accelerated during two
epochs: in its very first moments during a period of Inflation and much more
recently, at z < 1, when Dark Energy is hypothesized to drive cosmic
acceleration. The undiscovered mechanisms behind these two epochs represent
some of the most important open problems in fundamental physics. The large
cosmological volume at 2 < z < 5, together with the ability to efficiently
target high- galaxies with known techniques, enables large gains in the
study of Inflation and Dark Energy. A future spectroscopic survey can test the
Gaussianity of the initial conditions up to a factor of ~50 better than our
current bounds, crossing the crucial theoretical threshold of
of order unity that separates single field and
multi-field models. Simultaneously, it can measure the fraction of Dark Energy
at the percent level up to , thus serving as an unprecedented test of
the standard model and opening up a tremendous discovery space
Churches as firms : an exploration of regulatory similarities
Regulatory states manage religious activity within their jurisdiction in the same way they manage economic activity, in an alignment pattern that reflects institutionally embedded processes. Relying on regulatory institutional options to trace consistencies in the way a regime manages economic and religious activity, the article develops and tests theoretical accounts of the presence and content - in terms of comparative variation - of this alignment. The empirical setting, primarily OECD countries in recent decades, allows us to reverse the conventional causal view and treat religious regulation as causally embedded in the logic and practice of economic regulation. If reliance on regulation as a means of social control is bound by the same processes across domains, this may even suggest the existence of national cross-sectoral models of coordinating competition. The study elaborates a broad conceptualisation of regulatory governance with potentially wide applicability
Convection and Retro-Convection Enhanced Delivery: Some Theoretical Considerations Related to Drug Targeting
Delivery of drugs and macromolecules into the brain is a challenging problem, due in part to the blood–brain barrier. In this article, we focus on the possibilities and limitations of two infusion techniques devised to bypass the blood–brain barrier: convection enhanced delivery (CED) and retro-convection enhanced delivery (R-CED). CED infuses fluid directly into the interstitial space of brain or tumor, whereas R-CED removes fluid from the interstitial space, which results in the transfer of drugs from the vascular compartment into the brain or tumor. Both techniques have shown promising results for the delivery of drugs into large volumes of tissue. Theoretical approaches of varying complexity have been developed to better understand and predict brain interstitial pressures and drug distribution for these techniques. These theoretical models of flow and diffusion can only be solved explicitly in simple geometries, and spherical symmetry is usually assumed for CED, while axial symmetry has been assumed for R-CED. This perspective summarizes features of these models and provides physical arguments and numerical simulations to support the notion that spherical symmetry is a reasonable approximation for modeling CED and R-CED. We also explore the potential of multi-catheter arrays for delivering and compartmentalizing drugs using CED and R-CED
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