760 research outputs found
Examination of Edge Effects with Different Storage Conditions of Preplated Dimethyl Sulfoxide Nanospots in ChemLib 1,536- and 3,456-Well Assay-Ready Plates
For ultra-high-throughput screening, 10â30 nl of compound dissolved in 75% dimethyl sulfoxide (DMSO)/25% water (vol/vol) is spotted into 1,536- and 3,456-well ChemLib⢠plates (Aurora Biotechnologies, Carlsbad, CA) and stored appropriately for a short time before screening. Although this practice eliminates the compound plating bottleneck, plated volumes of DMSO slowly evaporate from assay wells if plates are not properly stored in the interim. Since many assays are sensitive to DMSO concentrations, even slight evaporation may cause intra-plate variation and thus decrease assay quality. Using a cytochrome P450 3A4 VividÂŽ Blue assay (Invitrogen, Carlsbad), we investigated the rate, pattern, and quantity of evaporation over a 1-year time frame to identify best practices for long-term (i.e., 6 months or greater) storage of assay-ready compound plates. Our findings regarding evaporation at plate edges indicate that nanospots preplated in ChemLib 1,536- or 3,456-well plates are best stored at â80°C, in a bag, with or without the outer evaporation wells filled or at â20°C, in a bag, with evaporation wells filled.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63203/1/adt.2008.169.pd
The Pathways for Intelligible Speech: Multivariate and Univariate Perspectives
An anterior pathway, concerned with extracting meaning from sound, has been identified in nonhuman primates. An analogous pathway has been suggested in humans, but controversy exists concerning the degree of lateralization and the precise location where responses to intelligible speech emerge. We have demonstrated that the left anterior superior temporal sulcus (STS) responds preferentially to intelligible speech (Scott SK, Blank CC, Rosen S, Wise RJS. 2000. Identification of a pathway for intelligible speech in the left temporal lobe. Brain. 123:2400-2406.). A functional magnetic resonance imaging study in Cerebral Cortex used equivalent stimuli and univariate and multivariate analyses to argue for the greater importance of bilateral posterior when compared with the left anterior STS in responding to intelligible speech (Okada K, Rong F, Venezia J, Matchin W, Hsieh IH, Saberi K, Serences JT,Hickok G. 2010. Hierarchical organization of human auditory cortex: evidence from acoustic invariance in the response to intelligible speech. 20: 2486-2495.). Here, we also replicate our original study, demonstrating that the left anterior STS exhibits the strongest univariate response and, in decoding using the bilateral temporal cortex, contains the most informative voxels showing an increased response to intelligible speech. In contrast, in classifications using local "searchlightsâ and a whole brain analysis, we find greater classification accuracy in posterior rather than anterior temporal regions. Thus, we show that the precise nature of the multivariate analysis used will emphasize different response profiles associated with complex sound to speech processin
The Number of Supernovae from Primordial Stars in the Universe
Recent simulations of the formation of the first luminous objects in the
universe predict isolated very massive stars to form in dark matter halos with
virial temperatures large enough to allow significant amounts of molecular
hydrogen to form. We construct a semi-analytic model based on the
Press-Schechter formalism and calibrate the minimum halos mass that may form a
primordial star with the results from extensive adaptive mesh refinement
simulations. The model also includes star formation in objects with virial
temperatures in excess of ten thousand Kelvin. The free parameters are tuned to
match the optical depth measurements by the WMAP satellite. The models
explicitly includes the negative feedback of the destruction of molecular
hydrogen by a soft UV background which is computed self-consistently. We
predict high redshift supernova rates as one of the most promising tools to
test the current scenario of primordial star formation. The supernova rate from
primordial stars peaks at redshifts ~20. Using an analytic model for the
luminosities of pair-instability supernovae we predict observable magnitudes
and discuss possible observational strategies. Such supernovae would release
enough metals corresponding to a uniform enrichment to a few hundred thousands
of solar metalicity. If some of these stars produce gamma ray bursts our rates
will be directly applicable to understanding the anticipated results from the
SWIFT satellite. This study highlights the great potential for the James Webb
space telescope in probing cosmic structure at redshifts greater than 20.Comment: 12 pages, 8 figures, submitted to Astrophysical Journa
Development of a Semi-Field System for Contained Field Trials With Aedes Aegypti in Southern Mexico
Development of new genetic approaches to either interfere with the ability of mosquitoes to transmit dengue virus or to reduce vector population density requires progressive evaluation from the laboratory to contained field trials, before open field release. Trials in contained outdoor facilities are an important part of this process because they can be used to evaluate the effectiveness and reliability of modified strains in settings that include natural environmental variations without releasing mosquitoes into the open field. We describe a simple and cost-effective semi-field system designed to study Aedes aegypti carrying a dominant lethal gene (fsRIDL) in semi-field conditions. We provide a protocol for establishing, maintaining, and monitoring stable Ae. aegypti population densities inside field cages
Differential expression and prognostic value of long nonâ coding RNA in HPVâ negative head and neck squamous cell carcinoma
BackgroundLong nonâ coding RNA (lncRNA) has emerged as a new avenue of interest due to its various biological functions in cancer. Abnormal expression of lncRNA has been reported in other malignancies but has been understudied in head and neck squamous cell carcinoma (HNSCC).MethodsThe lncRNA expression was interrogated via quantitative realâ time polymerase chain reaction (qRTâ PCR) array for 19 human papillomavirus (HPV)â negative HNSCC tumorâ normal pairs. The Cancer Genome Atlas (TCGA) was used to validate these results. The association between differentially expressed lncRNA and survival outcomes was analyzed.ResultsDifferential expression was validated for 5 lncRNA (SPRY4â IT1, HEIH, LUCAT1, LINC00152, and HAND2â AS1). There was also an inverse association between MEG3 expression (not significantly differentially expressed in TCGA tumors but highly variable expression) and 3â year recurrenceâ free survival (RFS).ConclusionWe identified and validated differential expression of 5 lncRNA in HPVâ negative HNSCC. Low MEG3 expression was associated with favorable 3â year RFS, although the significance of this finding remains unclear.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144638/1/hed25136_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144638/2/hed25136.pd
How Low Can We Go?: Comparing Long-term Oncologic Outcomes for APR and LAR in Very Low Rectal Cancer
Management of very low rectal cancer is one of the most challenging issues faced by colorectal surgeons. For tumors in the mid and upper rectum, procedures can be done to resect the cancer while maintaining continence, a major determinant of post-operative quality of life. In the low rectum, however, to optimize oncologic outcomes, many surgeons feel compelled to pursue abdominoperineal (APR) over low anterior resection (LAR), a sphincter-preserving procedure. It was hypothesized that after robust adjustment, procedure choice will not be associated with a difference in disease-free survival in the resection of tumors in the low rectum. To analyze this, the US Rectal Cancer Collaborative Database, a comprehensive, multi-center dataset obtained from six institutions between 2010 and 2016, was queried. Patients undergoing TME resection for Stage I-III very low rectal cancers (involvement) were selected for this study. Patients were categorized by procedure- LAR vs APR. Primary outcome was five-year disease-free survival. Secondary outcomes included overall survival, recurrence, length of stay, and complications. An adjusted analysis was performed to account for all known potential confounders. 431 patients with very low rectal cancer treated by either APR or LAR were identified. 154 (35.7%) underwent APR. The overall recurrence rate was 19.6%. Median follow-up time was 42.5 months. An analysis adjusted for age, gender, BMI, ASA class, and pathologic stage observed no difference in disease free survival between operative types (HR=0.90, 95% CI [0.53-1.52], p=0.70). Similarly, secondary outcomes demonstrated no significant difference between operation types, including length of stay (Beta: 0.04, Std. error = 0.25, p = 0.54), overall survival (HR=1.29, 95% CI [0.71-2.32], p=0.39), or complications (OR = 1.53, 95% CI [0.94 - 2.50], p=0.09). In this analysis, no significant difference in disease-free survival or overall survival was observed between patients undergoing APR or LAR for very low rectal cancer. This comprehensive study supports the treatment of very low rectal cancer, less than 5cm from the anorectal ring with no sphincter involvement, by either abdominal perineal or low anterior resection. Further studies may focus on patient-reported and quality of life outcomes which may influence decision-making
The Pathways for Intelligible Speech: Multivariate and Univariate Perspectives.
An anterior pathway, concerned with extracting meaning from sound, has been identified in nonhuman primates. An analogous pathway has been suggested in humans, but controversy exists concerning the degree of lateralization and the precise location where responses to intelligible speech emerge. We have demonstrated that the left anterior superior temporal sulcus (STS) responds preferentially to intelligible speech (Scott SK, Blank CC, Rosen S, Wise RJS. 2000. Identification of a pathway for intelligible speech in the left temporal lobe. Brain. 123:2400-2406.). A functional magnetic resonance imaging study in Cerebral Cortex used equivalent stimuli and univariate and multivariate analyses to argue for the greater importance of bilateral posterior when compared with the left anterior STS in responding to intelligible speech (Okada K, Rong F, Venezia J, Matchin W, Hsieh IH, Saberi K, Serences JT,Hickok G. 2010. Hierarchical organization of human auditory cortex: evidence from acoustic invariance in the response to intelligible speech. 20: 2486-2495.). Here, we also replicate our original study, demonstrating that the left anterior STS exhibits the strongest univariate response and, in decoding using the bilateral temporal cortex, contains the most informative voxels showing an increased response to intelligible speech. In contrast, in classifications using local "searchlights" and a whole brain analysis, we find greater classification accuracy in posterior rather than anterior temporal regions. Thus, we show that the precise nature of the multivariate analysis used will emphasize different response profiles associated with complex sound to speech processing
Planet Sensitivity from Combined Ground- and Space-based Microlensing Observations
To move one step forward toward a Galactic distribution of planets, we
present the first planet sensitivity analysis for microlensing events with
simultaneous observations from space and the ground. We present this analysis
for two such events, OGLE-2014-BLG-0939 and OGLE-2014-BLG-0124, which both show
substantial planet sensitivity even though neither of them reached high
magnification. This suggests that an ensemble of low to moderate magnification
events can also yield significant planet sensitivity and therefore probability
to detect planets. The implications of our results to the ongoing and future
space-based microlensing experiments to measure the Galactic distribution of
planets are discussed.Comment: 10 pages, 5 figures, 1 table; ApJ in pres
- âŚ