scholarly journals Spectral memory: Illumination-evoked plasticity

2018 ◽  
Author(s):  
Ifedayo-Emmanuel Adeyefa-Olasupo

AbstractHere human trichromats were presented with two types of scenes – geometric and real-world scenes –tinted with a shade of colour in order to destabilize the perceived illumination, and chromaticity of the retinal image of each scene. Each trichromat was instructed to adjust the chromaticity of the object embedded within each scene until its surface appeared devoid of any hue in the DKL colour space which spans two chromatic opponent axes – the S–(L+M) and L– M axis – and a luminance axis – the L+M axis. The following observations were made : (i) across scenes, adjustments were dispersed along the S–(L+M) axis, along which daylight is known to vary; (ii) across trichromats, for the geometric scenes, adjustments were biased towards the S pole of the S–(L+M) axis for one group (group 1), and towards the (L+M) pole for the other group (group 2); (iii) for the real-world scenes, adjustments for both groups systematically converged towards the (L+M) pole. These results suggest that when the core set of priors upon which the human visual system typically relies become ill-equipped, the human visual system is able to recruit one of the two illumination priors – PriorS or PriorL+M – in combination with the representation it has formed over time about the spectral composition of the illuminant associated with scenes the trichromatic observer is currently being exposed to within its ecological niche, as it attempts to stabilize the chromaticity of the retinal image of real-world scenes.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yonghong Li ◽  
Carmen H. Tong ◽  
Charles M. Rowland ◽  
Jeff Radcliff ◽  
Lance A. Bare ◽  
...  

AbstractIn clinical trials, vitamin D supplementation has been reported to reduce serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) but not high-density lipoprotein cholesterol (HDL-C). In this cohort study we evaluated the association between changes in vitamin D (25-hydroxyvitamin D) and changes in lipid levels in a real-world setting. Changes in lipid levels over a 1-year period were evaluated among individuals whose vitamin D levels increased (group 1) or decreased (group 2) by ≥ 10 ng/mL in year 2018 versus 2017 (cohort 1; n = 5580), in 2019 versus 2018 (cohort 2, n = 6057), or in 2020 versus 2019 (cohort 3, n = 7249). In each cohort, levels of TC, LDL-C, and TG decreased in group 1 and increased in group 2. Between-group differences in average changes in the 3 cohorts ranged from 10.71 to 12.02 mg/dL for TC, from 7.42 to 8.95 mg/dL for LDL-C, and from 21.59 to 28.09 mg/dL for TG. These differences were significant after adjusting for age, sex, race, education, body mass index, blood pressure, smoking status, geographical location, and baseline levels of vitamin D and lipids (P < 0.001). Changes in vitamin D levels were not significantly associated with changes in HDL-C levels.


Stroke ◽  
2001 ◽  
Vol 32 (suppl_1) ◽  
pp. 348-348
Author(s):  
Tudor G Jovin ◽  
Steven Goldstein ◽  
Gebel M James ◽  
Wechsler R Lawrence ◽  
Margareth-Beth Ott ◽  
...  

P51 Background and Purpose: The ischemic penumbra is composed of neurons that are functionally impaired but structurally intact, and thus potentially salvageable. Identifying the penumbra and its relationship with the ischemic core may lead to a more physiologic selection of patients who might benefit from recanalization therapy. We sought to explore the core/penumbra relationship by quantitatively measuring cerebral blood flow (CBF) in patients with acute M1 occlusion. Methods: 19 patients with M1 occlusion proven by CT angiography or conventional cerebral angiography underwent a Xe-CT/CBF study within 6 hours of symptoms onset. Mean CBF values were measured in the ipsilateral cortical MCA territory. The core was defined as areas with CBF< 8 ml/100g/min and the penumbra was defined as areas with CBF 9–20 ml/100g/min. Findings were correlated with the admission NIH stroke scale (NIHSS). Results: In 6/19 patients (31.5%)(group 1), the size of the penumbra was greater than twice the size of the core. In 8/19 patients (42.1%) (group 2), the size of the penumbra was approximately equal the size of the core. In 5/19 patients (26.8%)(group 3) the size of the penumbra was less than half the size of the core. The median core volumes for each of the three groups, expressed as percentage of core relative to ipsilateral cortical MCA territory, increased from group 1 to group 3. While there was a trend towards a correlation between the admission NIHSS and the combined core and penumbral volumes, no such correlation could be established between admission NIHSS and core or penumbral volumes alone. Conclusions: In the first 6 hours after M1 occlusion, penumbral volumes that are larger than or equal to core volumes are present in 14 out of 19 patients. A smaller core volume is associated with an increased penumbra to core ratio. The admission NIHSS in patients with M1 occlusion correlates with the combined volumes of core and penumbra.


2021 ◽  
Author(s):  
Dongzi Yang ◽  
Linlin Jiang ◽  
Yifan Qian ◽  
Xiaoli Chen ◽  
Xiaohui Ji ◽  
...  

Abstract BackgroundShort gamete coincubation in in vitro fertilization (IVF-S) combined with early rescue intracytoplasmic sperm injection (R-ICSI) and split IVF-ICSI insemination, are two methods to prevent unpredicted low or failed fertilization. This study aimed to determine the utility of IVF-S combined with R-ICSI and split IVF-ICSI during the first assisted reproductive technology (ART) cycle.Patients and methodsA single-center retrospective cohort study based on real-world data. Couples with a high risk of low IVF fertilization during the first ART cycle underwent IVF-S with R-ICSI (n=191) or split IVF-ICSI (n=775). Fertilization rate, embryo quality, and clinical outcomes were measured.ResultsAfter propensity score matching, we included 188 couples in the IVF-S with R-ICSI group as Group 1 and 720 in the split IVF-ICSI group as Group 2, with low IVF fertilization rates of 4.79% and 9.03%, respectively. Normal fertilization rates were similar in the two groups; however, Group1 had a higher multiple pronuclei rate (10.42% vs. 4.50%, P <0.001). The groups were similar for rates of high-quality embryos, blastocyst formation rate, embryo implantation, clinical pregnancy, miscarriage, loss to follow-up, and live birth. Low fertilization following IVF occurred in nine couples in Group 1 with 47 MII oocytes performed R-ICSI and 65 in Group 2 with 331 MII oocytes performed ICSI. Similar fertilization rate, embryo development, and clinical outcomes were noted in two groups with low fertilization.ConclusionsIVF-S with early R-ICSI and split IVF-ICSI were effective strategies in preventing IVF fertilization failure or low fertilization rate in couples with high-risk factors. IVF-S with early R-ICSI could become the preferred approach because of its advantages-fewer ICSI procedures, similar clinical pregnancy rate and live birth rate.


Perception ◽  
1982 ◽  
Vol 11 (3) ◽  
pp. 337-346 ◽  
Author(s):  
Leon N Piotrowski ◽  
Fergus W Campbell

To establish how little information the human visual system requires for recognition, common objects were digitally manipulated in the Fourier domain. The results demonstrate that it is not only possible, but also quite efficient, for a (biological) visual system to exist with very few phase relationships among the component spatial frequencies of the (retinal) image. A visual example is then presented which illustrates how certain phase relationships can hinder, or completely eliminate, the recognition of visual scenes.


2015 ◽  
Vol 23 (4) ◽  
pp. 384-391 ◽  
Author(s):  
Ozcan Basaran ◽  
Nesrin Filiz Basaran ◽  
Edip Guvenc Cekic ◽  
Ibrahim Altun ◽  
Volkan Dogan ◽  
...  

Introduction: Inappropriate use of oral anticoagulants (OACs) have not been well investigatedand, however, may be frequent in real-world practice in patients with nonvalvular atrial fibrillation (NVAF). This study was designed to evaluate the prescription patterns and appropriateness of OACs in patients with NVAF in real-world clinical settings. Methods: We performed a prospective, observational study (NCT02366338). A total of 148 patients with NVAF were screened for OAC prescription. Appropriateness of prescribing was evaluated using 9 criteria of the Medication Appropriateness Index (MAI): indication, choice, dosage, modalities and practicability of administration, drug–drug interactions, drug–disease interactions, duplication, and duration. For each criterion, the evaluator has to rate whether the medication is (A) appropriate, (B) inappropriate but with limited clinical importance, and (C) inappropriate. Results: Of 148 patients, 73 (50%) were on warfarin (group 1), 39 (26%) were on rivaroxaban (group 2), and 36 (24%) were on dabigatran therapy (group 3). The MAI showed that 83% of group 1, 28% of group 2, and 47% of group 3 patients had at least 1 inappropriate criterion. Moreover, according to the choice criterion, 37% of group 1, 8% of group 2 and 5% of group 3 were rated as inappropriate, and dosage was not appropriate in 77% of group 1, 23% of group 2, and 42% of group 3. Conclusion: Inappropriate drug use is frequent among patients with NVAF not only for warfarin but also for NOACs. Although there is an apparent improvement in thromboprophylaxis of NVAF, much more effort is needed for appropriate use of OACs.


1977 ◽  
Vol 27 (4) ◽  
pp. 189-197 ◽  
Author(s):  
G. J. Burton ◽  
S. Nagshineh ◽  
K. H. Ruddock

2003 ◽  
Vol 28 (5) ◽  
pp. 475-477 ◽  
Author(s):  
W. L. LAM ◽  
A. GARRIDO ◽  
J. VANDERMEULEN ◽  
M. J. FAGAN ◽  
P. R. W. STANLEY

We carried out a biomechanical study comparing tensile strength after using round-bodied or cutting needles for tendon repair. Swine tendons were repaired in three groups: Group 1 core suture repair only; group 2 core and circumferential suture repair; and group 3 isolated circumferential suture repair. The tendons were tested at longitudinal stress to failure at 5 mm/minute. No significant differences were found between the round-bodied and cutting needles in any group. Equal numbers in the core suture repair group failed by suture pullout when comparing cutting and round-bodied needles. We conclude that the choice of needle has no effect on the outcome of tendon repair if there is consistency of surgeon’s skill and experience.


2006 ◽  
Author(s):  
Kamel Belkacem-Boussaid ◽  
Balaji Raman ◽  
Gilberto Zamora ◽  
Yeshwanth Srinivasan ◽  
Sven-Erick Bursell

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5095-5095
Author(s):  
Abhay Singh ◽  
Sarah Sadek ◽  
Mark G. Faber ◽  
Jeffrey Baron ◽  
James E. Thompson ◽  
...  

BACKGROUND: After many decades of stagnation, several promising novel therapies have recently been approved for the management of patients (pts) with Acute Myeloid Leukemia (AML). Many of these target pts in specific clinical and molecular subsets such as midostaurin/gilteritinib for FLT3-mutated AML, liposomal daunorubicin-cytarabine for secondary AML, and fractionated gemtuzumab ozogamicin (GO) for good risk AML. To address the dismal outlook for elderly AML patients, we now have venetoclax or glasdegib combinations. Single agent FLT3 inhibitors (resulting in ~4 m improvement in overall survival (OS)) and IDH inhibitors (response rate 40%, doubled OS in responders) have shown to be superior to traditional approaches in the relapsed setting. Although these agents are exciting, a majority of pts with AML present with intermediate and high-risk disease and only a small subset will have actionable mutations. In order to determine the impact of these newer therapies on outcome for our pts, we investigated AML outcomes for pts diagnosed and treated since 2017 and compared these with survival for similar pts treated in the prior two years (y). METHODS: We performed a retrospective chart review to identify newly diagnosed pts treated with chemotherapy over a 2y period (2015-17) prior to the first FDA approval of Midostaurin in April, 2017 (old AML era or group 1) and the 2y since approval (2017-19; new AML era or group 2). We reviewed charts of 138 AML pts meeting these criteria at our institution: 79 in group 1 and 59 in group 2. Demographics, disease-specific variables, as well as outcomes of interest (overall survival (OS), overall response rate (CR/CRi)) were collected on an IRB-approved protocol. Responses were defined according to the 2003 International Working Group (IWG) criteria. Demographics, baseline characteristics, and treatment responses were analyzed using descriptive statistics. Overall survival was estimated utilizing Kaplan-Meier (KM) survival analysis. RESULTS: Clinical characteristics were comparable in both groups. Median age was 65y with slight differences in gender distribution (Table 1). ELN risk categories (Döhner, Blood. 2017) across the groups were similarly distributed; a majority of pts had intermediate and adverse risk characteristics. As expected, more pts received newer therapies in group 2. 6 pts (7.6%) in group 1 received new drugs (as part of clinical trials), while 31 (52%) received newer therapies in group 2. Newer therapies were mostly GO (28%), midostaurin (11%) and venetoclax (11%) with lesser percentages of the more specific targeted therapies. Median follow-up was 10m for group 1 and 8m for group 2. Median OS was 13m for group 1 and 20m for group 2, but the difference was not statistically significant (p=0.29) [Figure 1]. OS was significantly better in the subgroup of older AML pts (age ≥ 60y); median OS was 7m vs. 11m in groups 1 and 2 respectively (p=0.01).Rates of CR from induction therapy were comparable in both groups (68% in group 1 versus 65% in group 2). A larger number of pts (especially older pts) in group 2 went on to allogeneic bone marrow transplant (allo-HCT). This was perhaps due to increased recognition of performance status over age in selection of pts for allo-HCT and increased utilization of reduced intensity and non-myeloablative conditioning regimens. CONCLUSIONS: Our results indicate a positive impact on survival for pts diagnosed in the era of novel therapies in a real world setting, specifically for pts presenting at older ages. A larger cohort analysis to further evaluate these findings is currently underway. The expansion of the therapeutic armamentarium as well as expanded transplant options is encouraging and offers new hope for pts diagnosed with AML Disclosures Griffiths: Onconova Therapeutics: Other: PI on a clinical trial; Partner Therapeutics: Consultancy; Astex Phramaceuticals/Otsuka Pharmaceuticals: Consultancy, Research Funding; Appelis Pharmaceuticals: Other: PI on a clinical trial; Onconova Therapeutics: Other: PI on a clinical trial; Appelis Pharmaceuticals: Other: PI on a clinical trial; Boston Scientific: Consultancy; Genentech, Inc.: Research Funding; Genentech, Inc.: Research Funding; New Link Genetics: Consultancy; Astex Phramaceuticals/Otsuka Pharmaceuticals: Consultancy, Research Funding; Celgene, Inc: Consultancy, Research Funding; Celgene, Inc: Consultancy, Research Funding; Abbvie, Inc.: Consultancy, PI on a clinical trial; Abbvie, Inc.: Consultancy; New Link Genetics: Consultancy; Persimmune: Consultancy; Persimmune: Consultancy; Boston Scientific: Consultancy; Novartis Inc.: Consultancy; Partner Therapeutics: Consultancy; Novartis Inc.: Consultancy. Wang:Kite: Other: Advisory role; Jazz: Other: Advisory role; Amgen: Other: Advisory role; Agios: Other: Advisory role; Abbvie: Other: Advisory role; Daiichi: Other: Advisory role; Stemline: Other: Advisory role, Speakers Bureau; Pfizer: Other: Advisory role, Speakers Bureau; celyad: Other: Advisory role; Astellas: Other: Advisory role, Speakers Bureau. Thota:Incyte, Inc.: Speakers Bureau.


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