2,607 research outputs found
The Conditional Lucas & Kanade Algorithm
The Lucas & Kanade (LK) algorithm is the method of choice for efficient dense
image and object alignment. The approach is efficient as it attempts to model
the connection between appearance and geometric displacement through a linear
relationship that assumes independence across pixel coordinates. A drawback of
the approach, however, is its generative nature. Specifically, its performance
is tightly coupled with how well the linear model can synthesize appearance
from geometric displacement, even though the alignment task itself is
associated with the inverse problem. In this paper, we present a new approach,
referred to as the Conditional LK algorithm, which: (i) directly learns linear
models that predict geometric displacement as a function of appearance, and
(ii) employs a novel strategy for ensuring that the generative pixel
independence assumption can still be taken advantage of. We demonstrate that
our approach exhibits superior performance to classical generative forms of the
LK algorithm. Furthermore, we demonstrate its comparable performance to
state-of-the-art methods such as the Supervised Descent Method with
substantially less training examples, as well as the unique ability to "swap"
geometric warp functions without having to retrain from scratch. Finally, from
a theoretical perspective, our approach hints at possible redundancies that
exist in current state-of-the-art methods for alignment that could be leveraged
in vision systems of the future.Comment: 17 pages, 11 figure
Inability of immunohistochemistry to predict clinical outcomes of endometrial cancer patients
Gossett DR, Alo P, Bristow RE, Galati M, Kyshtoobayeva A, Fruehauf J, Montz FJ. Inability of immunohistochemistry to predict clinical outcomes of endometrial cancer patients. Introduction: Despite optimal surgery, some patients with early endometrial carcinoma develop recurrence and die of disease. A number of immunohistochemical (IHC)-identified cell products (markers) have been proposed as predictors of recurrence. This study characterizes a large series of endometrial carcinomas with previously described markers as well as markers that have not been investigated in endometrial carcinoma. Patients and methods: Women who had undergone surgery for endometrial carcinoma were identified and specimens accessed. Tissue blocks were evaluated for ten IHC markers. Results were correlated with last known clinical status. Results: Mean follow-up was 43 months; complete data were available on 117 patients. Two women died of other causes; of the remaining 115, eight died of disease and six were alive with recurrence at last follow-up (12%). Vascular endothelial growth factor staining independently predicted recurrence and death. However, in multivariate analyses, only FIGO stage predicted outcome. Discussion: Our goal was to identify markers to predict which women with endometrial carcinoma were likely to have disease recurrence. We evaluated cell-cycle regulatory proteins, growth factors, hormone receptors, and angiogenic factors, but did not identify any marker that independently predicted outcome in multivariate analysis. This may reflect the few negative outcomes in our population.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72601/1/j.1048-891x.2004.014028.x.pd
Evolved Gas Analysis of Mars Analog Samples from the Arctic Mars Analog Svalbard Expedition: Implications for Analyses by the Mars Science Laboratory
The 2011 Arctic Mars Analog Svalbard Expedition (AMASE) investigated several geologic settings on Svalbard, using methodologies and techniques being developed or considered for future Mars missions, such as the Mars Science Laboratory (MSL). The Sample Analysis at Mars (SAM) instrument suite on MSL consists of a quadrupole mass spectrometer (QMS), a gas chromatograph (GC), and a tunable laser spectrometer (TLS), which analyze gases created by pyrolysis of samples. During AMASE, a Hiden Evolved Gas Analysis-Mass Spectrometer (EGA-MS) system represented the EGA-QMS capability of SAM. Another MSL instrument, CheMin, will use x-ray diffraction (XRD) and x-ray fluorescence (XRF) to perform quantitative mineralogical characterization of samples. Field-portable versions of CheMin were used during AMASE. AMASE 2011 sites spanned a range of environments relevant to understanding martian surface materials, processes and habitability. They included the basaltic Sverrefjell volcano, which hosts carbonate globules, cements and coatings, carbonate and sulfate units at Colletth0gda, Devonian sandstone redbeds in Bockfjorden, altered basaltic lava delta deposits at Mt. Scott Keltie, and altered dolerites and volcanics at Botniahalvoya. Here we focus on SAM-like EGA-MS of a subset of the samples, with mineralogy comparisons to CheMin team results. The results allow insight into sample organic content as well as some constraints on sample mineralogy
Impact of National Cancer Institute Comprehensive Cancer Centers on Ovarian Cancer Treatment and Survival
BACKGROUND: The regional impact of care at a National Cancer Institute Comprehensive Cancer Center (NCI-CCC) on adherence to National Comprehensive Cancer Network (NCCN) ovarian cancer treatment guidelines and survival is unclear. STUDY DESIGN: We performed a retrospective population-based study of consecutive patients diagnosed with epithelial ovarian cancer between January 1, 1996 and December 31, 2006 in southern California. Patients were stratified according to care at an NCI-CCC (n = 5), non-NCI high-volume hospital (≥10 cases/year, HVH, n = 29), or low-volume hospital (<10 cases/year, LVH, n = 158). Multivariable logistic regression and Cox-proportional hazards models were used to examine the effect of NCI-CCC status on treatment guideline adherence and ovarian cancer-specific survival. RESULTS: A total of 9,933 patients were identified (stage I, 22.8%; stage II, 7.9%; stage III, 45.1%; stage IV, 24.2%), and 8.1% of patients were treated at NCI-CCCs. Overall, 35.7% of patients received NCCN guideline adherent care, and NCI-CCC status (odds ratio [OR] 1.00) was an independent predictor of adherence to treatment guidelines compared with HVHs (OR 0.83, 95% CI 0.70 to 0.99) and LVHs (OR 0.56, 95% CI 0.47 to 0.67). The median ovarian cancer-specific survivals according to hospital type were: NCI-CCC 77.9 (95% CI 61.4 to 92.9) months, HVH 51.9 (95% CI 49.2 to 55.7) months, and LVH 43.4 (95% CI 39.9 to 47.2) months (p < 0.0001). National Cancer Institute Comprehensive Cancer Center status (hazard ratio [HR] 1.00) was a statistically significant and independent predictor of improved survival compared with HVH (HR 1.18, 95% CI 1.04 to 1.33) and LVH (HR 1.30, 95% CI 1.15 to 1.47). CONCLUSIONS: National Cancer Institute Comprehensive Cancer Center status is an independent predictor of adherence to ovarian cancer treatment guidelines and improved ovarian cancer-specific survival. These data validate NCI-CCC status as a structural health care characteristic correlated with superior ovarian cancer quality measure performance. Increased access to NCI-CCCs through regional concentration of care may be a mechanism to improve clinical outcomes
Recommended from our members
Antimicrobial Resistance in Neisseria gonorrhoeae: Proceedings of the STAR Sexually Transmitted Infection-Clinical Trial Group Programmatic Meeting.
The goal of the Sexually Transmitted Infection Clinical Trial Group's Antimicrobial Resistance (AMR) in Neisseria gonorrhoeae (NG) meeting was to assemble experts from academia, government, nonprofit and industry to discuss the current state of research, gaps and challenges in research and technology and priorities and new directions to address the continued emergence of multidrug-resistant NG infections. Topics discussed at the meeting, which will be the focus of this article, include AMR NG global surveillance initiatives, the use of whole genome sequencing and bioinformatics to understand mutations associated with AMR, mechanisms of AMR, and novel antibiotics, vaccines and other methods to treat AMR NG. Key points highlighted during the meeting include: (i) US and International surveillance programs to understand AMR in NG; (ii) the US National Strategy for combating antimicrobial-resistant bacteria; (iii) surveillance needs, challenges, and novel technologies; (iv) plasmid-mediated and chromosomally mediated mechanisms of AMR in NG; (v) novel therapeutic (eg, sialic acid analogs, factor H [FH]/Fc fusion molecule, monoclonal antibodies, topoisomerase inhibitors, fluoroketolides, LpxC inhibitors) and preventative (eg, peptide mimic) strategies to combat infection. The way forward will require renewed political will, new funding initiatives, and collaborations across academic and commercial research and public health programs
Discovery of a Transiting Adolescent Sub-Neptune Exoplanet with K2
The role of stellar age in the measured properties and occurrence rates of
exoplanets is not well understood. This is in part due to a paucity of known
young planets and the uncertainties in age-dating for most exoplanet host
stars. Exoplanets with well-constrained ages, particularly those which are
young, are useful as benchmarks for studies aiming to constrain the
evolutionary timescales relevant for planets. Such timescales may concern
orbital migration, gravitational contraction, or atmospheric photo-evaporation,
among other mechanisms. Here we report the discovery of an adolescent
transiting sub-Neptune from K2 photometry of the low-mass star K2-284. From
multiple age indicators we estimate the age of the star to be 120 Myr, with a
68% confidence interval of 100-760 Myr. The size of K2-284 b ( = 2.8
0.1 ) combined with its youth make it an intriguing case study for
photo-evaporation models, which predict enhanced atmospheric mass loss during
early evolutionary stages.Comment: Accepted to AJ, 36 pages, 17 figures, 5 table
Concept and optical design of the cross-disperser module for CRIRES
This is the peer reviewed version of the following article: Oliva, Ernesto, A. Tozzi, D. Ferruzzi, L. Origlia, A. Hatzes, R. Follert, T. Loewinger et al. "Concept and optical design of the cross-disperser module for CRIRES+." In SPIE Astronomical Telescopes+ Instrumentation, pp. 91477R-91477R. International Society for Optics and Photonics, 2014, which has been published in final form at 10.1117/12.2054381
- …