706 research outputs found
Differential Gene Expression in Liver, Gill, and Olfactory Rosettes of Coho Salmon (Oncorhynchus kisutch) After Acclimation to Salinity.
Most Pacific salmonids undergo smoltification and transition from freshwater to saltwater, making various adjustments in metabolism, catabolism, osmotic, and ion regulation. The molecular mechanisms underlying this transition are largely unknown. In the present study, we acclimated coho salmon (Oncorhynchus kisutch) to four different salinities and assessed gene expression through microarray analysis of gills, liver, and olfactory rosettes. Gills are involved in osmotic regulation, liver plays a role in energetics, and olfactory rosettes are involved in behavior. Between all salinity treatments, liver had the highest number of differentially expressed genes at 1616, gills had 1074, and olfactory rosettes had 924, using a 1.5-fold cutoff and a false discovery rate of 0.5. Higher responsiveness of liver to metabolic changes after salinity acclimation to provide energy for other osmoregulatory tissues such as the gills may explain the differences in number of differentially expressed genes. Differentially expressed genes were tissue- and salinity-dependent. There were no known genes differentially expressed that were common to all salinity treatments and all tissues. Gene ontology term analysis revealed biological processes, molecular functions, and cellular components that were significantly affected by salinity, a majority of which were tissue-dependent. For liver, oxygen binding and transport terms were highlighted. For gills, muscle, and cytoskeleton-related terms predominated and for olfactory rosettes, immune response-related genes were accentuated. Interaction networks were examined in combination with GO terms and determined similarities between tissues for potential osmosensors, signal transduction cascades, and transcription factors
Measuring Basal Force Fluctuations of Debris Flows Using Seismic Recordings and Empirical Green's Functions
We present a novel method for measuring the fluctuating basal normal and shear stresses of debris flows by using alongâchannel seismic recordings. Our method couples a simple parameterization of a debris flow as a seismic source with direct measurements of seismic path effects using empirical Green's functions generated with a force hammer. We test this method using two largeâscale (8 and 10 mÂł) experimental flows at the U.S. Geological Survey debrisâflow flume that were recorded by dozens of threeâcomponent seismic sensors. The seismically derived basal stress fluctuations compare well in amplitude and timing to independent force plate measurements within the valid frequency range (15â50 Hz). We show that although the highâfrequency seismic signals provide bandâlimited forcing information, there are systematic relations between the fluctuating stresses and independently measured flow properties, especially mean basal shear stress and flow thickness. However, none of the relationships are simple, and since the flow properties also correlate with one another, we cannot isolate a single factor that relates in a simple way to the fluctuating forces. Nevertheless, our observations, most notably the gradually declining ratio of fluctuating to mean basal stresses during flow passage and the distinctive behavior of the coarse, unsaturated flow front, imply that flow style may be a primary control on the conversion of translational to vibrational kinetic energy. This conversion ultimately controls the radiation of highâfrequency seismic waves. Thus, flow style may provide the key to revealing the nature of the relationship between fluctuating forces and other flow properties
Measuring Basal Force Fluctuations of Debris Flows Using Seismic Recordings and Empirical Green's Functions
We present a novel method for measuring the fluctuating basal normal and shear stresses of debris flows by using alongâchannel seismic recordings. Our method couples a simple parameterization of a debris flow as a seismic source with direct measurements of seismic path effects using empirical Green's functions generated with a force hammer. We test this method using two largeâscale (8 and 10 mÂł) experimental flows at the U.S. Geological Survey debrisâflow flume that were recorded by dozens of threeâcomponent seismic sensors. The seismically derived basal stress fluctuations compare well in amplitude and timing to independent force plate measurements within the valid frequency range (15â50 Hz). We show that although the highâfrequency seismic signals provide bandâlimited forcing information, there are systematic relations between the fluctuating stresses and independently measured flow properties, especially mean basal shear stress and flow thickness. However, none of the relationships are simple, and since the flow properties also correlate with one another, we cannot isolate a single factor that relates in a simple way to the fluctuating forces. Nevertheless, our observations, most notably the gradually declining ratio of fluctuating to mean basal stresses during flow passage and the distinctive behavior of the coarse, unsaturated flow front, imply that flow style may be a primary control on the conversion of translational to vibrational kinetic energy. This conversion ultimately controls the radiation of highâfrequency seismic waves. Thus, flow style may provide the key to revealing the nature of the relationship between fluctuating forces and other flow properties
Differential Expression of Extracellular Matrix-Mediated Pathways in Single-Suture Craniosynostosis
Craniosynostosis is a disease defined by premature fusion of one or more cranial sutures. The mechanistic pathology of single-suture craniosynostosis is complex and while a number of genetic biomarkers and environmental predispositions have been identified, in many cases the causes remain controversial and inconclusive. In this study, gene expression data from 199 patients with isolated sagittal (nâ=â100), unilateral coronal (nâ=â50), and metopic (nâ=â49) synostosis are compared against both a control population (nâ=â50), as well as each other. After controlling for variables contributing to potential bias, FGF7, SFRP4, and VCAM1 emerged as genes associated with single-suture craniosynostosis due to their significantly large changes in gene expression compared to the control population. Pathway analysis implicated focal adhesion and extracellular matrix (ECM)-receptor interaction as differentially regulated gene networks when comparing all cases of single-suture synostosis and controls. Lastly, overall gene expression was found to be highly conserved between coronal and metopic cases, as evidenced by the fact that WNT2 and IGFBP2 were the only genes differentially regulated to a significantly large extent in a direct comparison. The identification of genes and gene networks associated with Fgf/Igf/Wnt signaling and ECM-mediated focal adhesion not only support the involvement of biomarkers previously reported to be related to craniosynostosis, but also introduce novel transcripts and pathways that may play critical roles in its pathogenesis
BUDAYA KEDIRI DALAM PEMBELAJARAN MATEMATIKA (PENGEMBANGAN LEMBAR KEGIATAN SISWA (LKS) BERBASIS ETNOMATEMATIKA MELALUI PENDEKATAN SAINTIFIK)
Tujuan penelitian ini adalah untuk mengetahui pengembangan LKS berbasis etnomatematika melalui pendekatan saintifik yang dapat meningkatkan kualitas pembelajaran. Penelitian ini merupakan penelitian pengembangan (R & D) dengan menggunakan desain pengembangan ADDIE yang terdiri dari lima tahap yaitu Analysis (Analisis), Design (Perancangan), Development (Pengembangan), Implementation (Implementasi), dan Evaluation (Evaluasi). Dengan subyek penelitian siswa kelas VIII SMP Negeri 5 Kediri. Penelitian ini menggunakan beberapa instrumen diantaranya lembar penilaian oleh ahli media dan ahli materi, serta angket siswa. Luaran yang diharapkan berupa modul LKS matematika berbasis etnomatematika melalui pendekatan saitifik, sehingga dapat diketahui hasil kevalidan, kepraktisan dan keefektifan
A Novel Antibody-Based Biomarker for Chronic Algal Toxin Exposure and Sub-Acute Neurotoxicity
The neurotoxic amino acid, domoic acid (DA), is naturally produced by marine phytoplankton and presents a significant threat to the health of marine mammals, seabirds and humans via transfer of the toxin through the foodweb. In humans, acute exposure causes a neurotoxic illness known as amnesic shellfish poisoning characterized by seizures, memory loss, coma and death. Regular monitoring for high DA levels in edible shellfish tissues has been effective in protecting human consumers from acute DA exposure. However, chronic low-level DA exposure remains a concern, particularly in coastal and tribal communities that subsistence harvest shellfish known to contain low levels of the toxin. Domoic acid exposure via consumption of planktivorous fish also has a profound health impact on California sea lions (Zalophus californianus) affecting hundreds of animals yearly. Due to increasing algal toxin exposure threats globally, there is a critical need for reliable diagnostic tests for assessing chronic DA exposure in humans and wildlife. Here we report the discovery of a novel DA-specific antibody response that is a signature of chronic low-level exposure identified initially in a zebrafish exposure model and confirmed in naturally exposed wild sea lions. Additionally, we found that chronic exposure in zebrafish caused increased neurologic sensitivity to DA, revealing that repetitive exposure to DA well below the threshold for acute behavioral toxicity has underlying neurotoxic consequences. The discovery that chronic exposure to low levels of a small, water-soluble single amino acid triggers a detectable antibody response is surprising and has profound implications for the development of diagnostic tests for exposure to other pervasive environmental toxins
Profiling quality of care for patients with chronic headache in three different German hospitals â a case study
BACKGROUND: Legal requirements for quality assurance in German rehabilitation hospitals include comparisons of providers. Objective is to describe and to compare outcome quality of care offered by three hospitals providing in-patient rehabilitative treatment exemplified for patients with chronic headache. METHODS: We performed a prospective three center observational study on patients suffering from chronic headache. Patients underwent interventions commonly used according to internal guidelines of the hospitals. Measurements were taken at three points in time (at admission, at discharge and 6 months after discharge). Indicators of outcome quality included pain intensity and frequency of pain, functional ability, depression, quality of life and health related behavior. Analyses of differences amongst the hospitals were adjusted by covariates due to case-mix situation. RESULTS: 306 patients from 3 hospitals were included in statistical analysis. Amongst the hospitals, patients differed significantly in age, education, diagnostic subgroups, beliefs, and with respect to some pain-related baseline values (covariates). Patients in all three hospitals benefited from intervention to a clinically relevant degree. At discharge from hospital, outcome quality differed significantly after adjustment according to case-mix only in terms of patients' global assessment of treatment results. Six months after discharge, the only detectable significant differences were for secondary outcomes like improved coping with stress or increased use of self-help. The profiles for satisfaction with the hospital stay showed clear differences amongst patients. CONCLUSION: The results of this case study do not suggest a definite overall ranking of the three hospitals that were compared, but outcome profiles offer a multilayer platform of reliable information which might facilitate decision making
Cervical and Vulvar Cancer Risk in Relation to the Joint Effects of Cigarette Smoking and Genetic Variation in Interleukin 2.
Cigarette smoking is an established cofactor to human papillomavirus (HPV) in the development of cervical and vulvar squamous cell carcinoma (SCC), and may influence risk through an immunosuppressive pathway. Genetic variation in interleukin 2 (IL2), associated in some studies with the inhibition of HPV-targeted immunity, may modify the effect of smoking on the risk of HPV-related anogenital cancers. We conducted a population-based case-only study to measure the departure from a multiplicative joint effect of cigarette smoking and IL2 variation on cervical and vulvar SCC. Genotyping of the four IL2 tagSNPs (rs2069762, rs2069763, rs2069777, and rs2069778) was done in 399 cervical and 486 vulvar SCC cases who had been interviewed regarding their smoking history. Compared with cases carrying the rs2069762 TT genotype, we observed significant departures from multiplicativity for smoking and carriership of the TG or GG genotypes in vulvar SCC risk [interaction odds ratio (IOR), 1.67; 95% confidence interval (CI), 1.16-2.41]. Carriership of one of three diplotypes, together with cigarette smoking, was associated with either a supramultiplicative (TGCT/GGCC; IOR, 2.09; 95% CI, 0.98-4.46) or submultiplicative (TTCC/TGTC; IOR, 0.37; 95% CI, 0.16-0.85 or TGCT/TGCC; IOR, 0.37; 95% CI, 0.15-0.87) joint effect in vulvar cancer risk. For cervical SCC, departure from multiplicativity was observed for smokers homozygous for the rs2069763 variant allele (TT versus GG or GT genotypes; IOR, 1.87; 95% CI, 1.00-3.48), and for carriership of the TTCC/TTCC diplotype (IOR, 2.08; 95% CI, 1.01-4.30). These results suggest that cervical and vulvar SCC risk among cigarette smokers is modified by genetic variation in IL2. (Cancer Epidemiol Biomarkers Prev 2008;17(7):1790-9)
Seasonal changes in patterns of gene expression in avian song control brain regions.
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Photoperiod and hormonal cues drive dramatic seasonal changes in structure and function of the avian song control system. Little is known, however, about the patterns of gene expression associated with seasonal changes. Here we address this issue by altering the hormonal and photoperiodic conditions in seasonally-breeding Gambel's white-crowned sparrows and extracting RNA from the telencephalic song control nuclei HVC and RA across multiple time points that capture different stages of growth and regression. We chose HVC and RA because while both nuclei change in volume across seasons, the cellular mechanisms underlying these changes differ. We thus hypothesized that different genes would be expressed between HVC and RA. We tested this by using the extracted RNA to perform a cDNA microarray hybridization developed by the SoNG initiative. We then validated these results using qRT-PCR. We found that 363 genes varied by more than 1.5 fold (>log(2) 0.585) in expression in HVC and/or RA. Supporting our hypothesis, only 59 of these 363 genes were found to vary in both nuclei, while 132 gene expression changes were HVC specific and 172 were RA specific. We then assigned many of these genes to functional categories relevant to the different mechanisms underlying seasonal change in HVC and RA, including neurogenesis, apoptosis, cell growth, dendrite arborization and axonal growth, angiogenesis, endocrinology, growth factors, and electrophysiology. This revealed categorical differences in the kinds of genes regulated in HVC and RA. These results show that different molecular programs underlie seasonal changes in HVC and RA, and that gene expression is time specific across different reproductive conditions. Our results provide insights into the complex molecular pathways that underlie adult neural plasticity
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