2,772 research outputs found
Multiple Effects of Prefrontal Lesions on Task-Switching
This study examined the performance of 41 patients with focal prefrontal cortical lesions and 38 healthy controls on a task-switching procedure. Three different conditions were evaluated: single tasks without switches and two switching tasks with the currently relevant task signalled either 1500 ms (Long Cue) or 200 ms (Short Cue) before the stimulus. Patients with Superior Medial lesions showed both a general slowing of reaction time (RT) and a significantly increased switch cost as measured by RT. No other prefrontal group showed this increased reaction time switch cost. Increased error rates in the switching conditions, on the other hand, were observed in patients with Inferior Medial lesions and, to a lesser extent, ones with Superior Medial lesions. Patients with left dorsolateral lesions (9/46v) showed slower learning of the task as indicated by a high error rate early on. Several different processes are involved in task-switching and these are selectively disrupted by lesions to specific areas of the frontal lobes
Prognostic implications of the extent of downstaging after neoadjuvant therapy for oesophageal adenocarcinoma and oesophageal squamous cell carcinoma
Background: There are few data evaluating the extent of downstaging in patients with oesophageal adenocarcinoma and oesophageal squamous cell carcinoma and the difference in outcomes for a similar pathological stage in neoadjuvant-naive patients. The aim of this study was to characterize the prognostic value of downstaging extent in patients receiving neoadjuvant therapy for oesophageal cancer.Methods: Oesophageal adenocarcinoma and oesophageal squamous cell carcinoma patients receiving either neoadjuvant chemotherapy or neoadjuvant chemoradiotherapy between 2004 and 2017 were identified from the National Cancer Database. The extent of downstaging was defined as the extent of migration between groups (for example stage IVa to IIIb = one stage). Cox multivariable regression was used to produce adjusted models for downstaging extent.Results: Of 13 594 patients, 11 355 with oesophageal adenocarcinoma and 2239 with oesophageal squamous cell carcinoma were included. In oesophageal adenocarcinoma, patients with downstaged disease by three or more stages (hazards ratio (HR) 0.40, 95 per cent c.i. 0.36 to 0.44, P < 0.001), two stages (HR 0.43, 95 per cent c.i. 0.39 to 0.48, P < 0.001), or one stage (HR 0.57, 95 per cent c.i. 0.52 to 0.62, P < 0.001) had significantly longer survival than those with upstaged disease in adjusted analyses. In oesophageal squamous cell carcinoma, patients with downstaged disease by three or more stages had significantly longer survival than those with less downstaged disease, no change, or upstaged disease. Patients with downstaged disease by three or more stages (HR 0.55, 95 per cent c.i. 0.43 to 0.71, P < 0.001), two stages (HR 0.58, 95 per cent c.i. 0.46 to 0.73, P < 0.001), or one stage (HR 0.69, 95 per cent c.i. 0.55 to 0.86, P = 0.001) had significantly longer survival than those with upstaged disease in adjusted analyses.Conclusion: The extent of downstaging is an important prognosticator, whereas the optimal neoadjuvant therapy remains controversial. Identifying biomarkers associated with response to neoadjuvant regimens may permit individualized treatment
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Linked CSF reduction of phosphorylated tau and IL-8 in HIV associated neurocognitive disorder.
HIV-associated neurocognitive disorder (HAND) is a common condition in both developed and developing nations, but its cause is largely unknown. Previous research has inconsistently linked Alzheimer's disease (AD), viral burden, and inflammation to the onset of HAND in HIV-infected individuals. Here we simultaneously measured cerebrospinal fluid (CSF) levels of established amyloid and tau biomarkers for AD, viral copy numbers, and six key cytokines in 41 HIV-infected individuals off combination anti-retroviral therapy (14 with HAND) who underwent detailed clinical and neuropsychological characterization, and compared their CSF patterns with those from young healthy subjects, older healthy subjects with normal cognition, and older people with AD. HAND was associated with the lowest CSF levels of phosphorylated tau (p-Tau181) after accounting for age and race. We also found very high CSF levels of the pro-inflammatory interferon gamma-induced protein 10 (IP-10/CXCL10) in HIV regardless of cognition, but elevated CSF interleukin 8 (IL-8/CXCL8) only in HIV-NC but not HAND. Eleven HIV-infected subjects underwent repeat CSF collection six months later and showed strongly correlated longitudinal changes in p-Tau181 and IL-8 levels (R = 0.841). These data suggest reduced IL-8 relative to IP-10 and reduced p-Tau181 to characterize HAND
Efficient Photometric Selection of Quasars from the Sloan Digital Sky Survey: 100,000 z<3 Quasars from Data Release One
We present a catalog of 100,563 unresolved, UV-excess (UVX) quasar candidates
to g=21 from 2099 deg^2 of the Sloan Digital Sky Survey (SDSS) Data Release One
(DR1) imaging data. Existing spectra of 22,737 sources reveals that 22,191
(97.6%) are quasars; accounting for the magnitude dependence of this
efficiency, we estimate that 95,502 (95.0%) of the objects in the catalog are
quasars. Such a high efficiency is unprecedented in broad-band surveys of
quasars. This ``proof-of-concept'' sample is designed to be maximally
efficient, but still has 94.7% completeness to unresolved, g<~19.5, UVX quasars
from the DR1 quasar catalog. This efficient and complete selection is the
result of our application of a probability density type analysis to training
sets that describe the 4-D color distribution of stars and spectroscopically
confirmed quasars in the SDSS. Specifically, we use a non-parametric Bayesian
classification, based on kernel density estimation, to parameterize the color
distribution of astronomical sources -- allowing for fast and robust
classification. We further supplement the catalog by providing photometric
redshifts and matches to FIRST/VLA, ROSAT, and USNO-B sources. Future work
needed to extend the this selection algorithm to larger redshifts, fainter
magnitudes, and resolved sources is discussed. Finally, we examine some science
applications of the catalog, particularly a tentative quasar number counts
distribution covering the largest range in magnitude (14.2<g<21.0) ever made
within the framework of a single quasar survey.Comment: 35 pages, 11 figures (3 color), 2 tables, accepted by ApJS; higher
resolution paper and ASCII version of catalog available at
http://sdss.ncsa.uiuc.edu/qso/nbckde
Mapping ground instability in areas of geotechnical infrastructure using satellite InSAR and Small UAV Surveying: a case study in Northern Ireland
Satellite Interferometric Synthetic Aperture Radar (InSAR), geological data and Small Unmanned Aerial Vehicle (SUAV) surveying was used to enhance our understanding of ground movement at five areas of interest in Northern Ireland. In total 68 ERS-1/2 images 1992–2000 were processed with the Small Baseline Subset (SBAS) InSAR technique to derive the baseline ground instability scenario of key areas of interest for five stakeholders: TransportNI, Northern Ireland Railways, Department for the Economy, Arup, and Belfast City Council. These stakeholders require monitoring of ground deformation across either their geotechnical infrastructure (i.e., embankments, cuttings, engineered fills and earth retaining structures) or assessment of subsidence risk as a result of abandoned mine workings, using the most efficient, cost-effective methods, with a view to minimising and managing risk to their businesses. The InSAR results provided an overview of the extent and magnitude of ground deformation for a 3000 km2 region, including the key sites of the disused salt mines in Carrickfergus, the Belfast–Bangor railway line, Throne Bend and Ligoniel Park in Belfast, Straidkilly and Garron Point along the Antrim Coast Road, plus other urbanised areas in and around Belfast. Tailored SUAV campaigns with a X8 airframe and generation of very high resolution ortho-photographs and a 3D surface model via the Structure from Motion (SfM) approach at Maiden Mount salt mine collapse in Carrickfergus in 2016 and 2017 also demonstrate the benefits of very high resolution surveying technologies to detect localised deformation and indicators of ground instabilit
Foreign Object Damage in an Oxide/Oxide Composite at Ambient Temperature
ABSTRACT Foreign object damage (FOD) behavior of an oxide/oxide (N720/AS) ceramic matrix composite (CMC) was determined at ambient temperature using impact velocities ranging from 100 to 400 m/s by 1.59-mm diameter steel-ball projectiles
Variation in Vital-rate Sensitivity Between Populations of Texas Horned Lizards
Demographic studies of imperiled populations can aid managers in planning conservation actions. However, applicability of findings for a single population across a species’ range is sometimes questionable. We conducted long-term studies (8 and 9 years, respectively) of 2 populations of the lizard Phrynosoma cornutum separated by 1000 km within the historical distribution of the species. The sites were a 15-ha urban wildlife reserve on Tinker Air Force Base (TAFB) in central Oklahoma and a 6000-ha wildland site in southern Texas, the Chaparral Wildlife Management Area (CWMA). We predicted a trade-off between the effect of adult survival and fecundity on population growth rate (λ), leading to population-specific contributions of individual vital rates to λ and individualized strategies for conservation and management of this taxon. The CWMA population had lower adult survival and higher fecundity than TAFB. As predicted, there was a trade-off in the effects of adult survival and fecundity on λ between the two sites; fecundity affected λ more at CWMA than at TAFB. However, adult survival had the smallest effect on λ in both populations. We found that recruitment in P. cornutum most affected λ at both sites, with hatchling survival having the strongest influence on λ. Management strategies focusing on hatchling survival would strongly benefit both populations. As a consequence, within the constraint of the need to more accurately estimate hatchling survival, managers across the range of species such as P. cornutum could adopt similar management priorities with respect to stage classes, despite intra-population differences in population vital rates
Quantitative data on red cell measures of iron status and their relation to the magnitude of the systemic inflammatory response and survival in patients with colorectal cancer
Background:
Inflammation is recognised to be associated with perturbation of serum measures of iron status. However, the impact of colorectal cancer associated host inflammation on red cell measures of iron status has not been previously quantified.
Methods:
Patients undergoing elective surgery with curative intent, for colorectal cancer, at a single centre between 2008 and 2017 were included (n = 824). Blood samples taken for C-reactive protein (CRP), albumin, and full blood count (FBC) allowed patients to be grouped by modified Glasgow Prognostic Score (mGPS), and anaemia subtype (haemoglobin (Hb) M < 130 mg/L and F < 120 mg/L, with microcytic anaemia being mean corpuscular volume (MCV) < 80 f/L, and normocytic anaemia with MCV 80–100 f/L). Relationships between these groupings and red cell measures iron status including Hb, MCV, mean corpuscular haemoglobin (MCH) and red cell distribution width (RDW) were examined.
Results:
The combination of increasing T stage and increasing mGPS was associated with lower Hb, lower MCV, lower MCH, higher RDW, and higher prevalence of both microcytic and normocytic anaemia (all p < 0.001). The combination of CRP >10 mg/L and albumin <35 g/L was associated with lower Hb, lower MCV, lower MCH, higher RDW, and higher prevalence of both microcytic and normocytic anaemia (all p < 0.010). At multivariate Cox regression only Hb remained significantly associated with cancer specific (HR 0.98, 95% CI 0.97–0.99, p < 0.001), and overall survival (HR 0.98, 95% CI 0.97–0.99, p = 0.001).
Conclusions:
The presence of a host systemic inflammatory response to colorectal cancer was associated with significant perturbation of red cell measure of iron status
Perioperative blood transfusion is associated with the postoperative systemic inflammatory response and poorer outcomes following surgery for colorectal cancer
Background:
The present study investigated relationships between perioperative blood transfusion, postoperative systemic inflammatory response, and outcomes following surgery for colorectal cancer.
Methods:
Data were recorded for patients (n = 544) undergoing potentially curative, elective surgery for colorectal cancer at a single center between 2012 and 2017. Transfusion history was obtained retrospectively from electronic records. Associations between blood transfusion, postoperative C-reactive protein (CRP), albumin, hemoglobin, complications, cancer-specific survival and overall survival (OS) were assessed using propensity score matching (n =116).
Results:
Of 544 patients, the majority were male (n =294, 54%), over 65 years of age (n =350, 64%), and with colonic (n =347, 64%) node-negative disease (n =353, 65%). Eighty-six patients (16%) required perioperative blood transfusion. In the unmatched cohort, blood transfusion was associated with higher median postoperative day (POD) 3 CRP {143 [interquartile range (IQR) 96–221 mg/L] vs. 120 (IQR 72–188 mg/L); p = 0.004}, lower median POD 3 albumin [24 (IQR 20–26 g/L) vs. 27 (IQR 24–30 g/L); p < 0.001], more postoperative complications [odds ratio (OR) 3.28, 95% confidence interval (CI) 2.03–5.29] and poorer OS [hazard ratio (HR) 3.18, 95% CI 2.08–4.84]. In the propensity score matched cohort, blood transfusion was similarly associated with higher median POD 3 CRP [130 (IQR 93–196 mg/L) vs. 113 (IQR 66–173 mg/L); p = 0.046], lower median POD 3 albumin [24 (IQR 20–26 g/L) vs. 26 (IQR 24–30 g/L); p < 0.001], more postoperative complications (OR 2.91, 95% CI 1.36–6.20) and poorer OS (HR 2.38, 95% CI 0.99–5.73).
Conclusions:
Perioperative blood transfusion was associated with postoperative inflammation, complications, and poorer survival in patients undergoing colorectal cancer surgery, with and without propensity score techniques
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