scholarly journals Spectral memory: Illumination-evoked plasticity

2018 ◽  
Author(s):  
Ifedayo-Emmanuel Adeyefa-Olasupo
Keyword(s):  
Visual System ◽  
Real World ◽  
Human Visual System ◽  
Retinal Image ◽  
Spectral Composition ◽  
Colour Space ◽  
The Core ◽  
Core Set ◽  
Group 2 ◽  
Group 1

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.

scholarly journals Association of changes in lipid levels with changes in vitamin D levels in a real-world setting

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yonghong Li ◽  
Carmen H. Tong ◽  
Charles M. Rowland ◽  
Jeff Radcliff ◽  
Lance A. Bare ◽  
...  
Keyword(s):  
Vitamin D ◽  
Real World ◽  
Smoking Status ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Lipid Levels ◽  
Real World Setting ◽  
Vitamin D Levels ◽  
Group 2 ◽  
Group 1

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.

scholarly journals Patterns of core and penumbra in acute MI occlusion and their clinical correlates

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 ◽  
...  
Keyword(s):  
Ischemic Penumbra ◽  
The Core ◽  
Functionally Impaired ◽  
Acute Mi ◽  
Group 3 ◽  
Group 2 ◽  
Core Volume ◽  
Selection Of Patients ◽  
Selection Of ◽  
Group 1

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.

scholarly journals The Effect of Early Rescue ICSI and Split IVF-ICSI in Preventing Low Fertilization Rate During the First ART Cycle: A Real-world Retrospective Cohort Study

2021 ◽  
Author(s):  
Dongzi Yang ◽  
Linlin Jiang ◽  
Yifan Qian ◽  
Xiaoli Chen ◽  
Xiaohui Ji ◽  
...  
Keyword(s):  
Cohort Study ◽  
High Risk ◽  
Real World ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Fertilization Rate ◽  
Clinical Pregnancy ◽  
Fertilization Rates ◽  
Group 2 ◽  
Group 1

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.

A Demonstration of the Visual Importance and Flexibility of Spatial-Frequency Amplitude and Phase

Perception ◽  
1982 ◽  
Vol 11 (3) ◽  
pp. 337-346 ◽  
Author(s):  
Leon N Piotrowski ◽  
Fergus W Campbell
Keyword(s):  
Spatial Frequency ◽  
Visual System ◽  
Human Visual System ◽  
Retinal Image ◽  
Fourier Domain ◽  
Spatial Frequencies ◽  
Visual Importance ◽  
Visual Scenes ◽  
Phase Relationships

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.

scholarly journals PRescriptiOn PattERns of Oral Anticoagulants in Nonvalvular Atrial Fibrillation (PROPER study)

2015 ◽  
Vol 23 (4) ◽  
pp. 384-391 ◽  
Author(s):  
Ozcan Basaran ◽  
Nesrin Filiz Basaran ◽  
Edip Guvenc Cekic ◽  
Ibrahim Altun ◽  
Volkan Dogan ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Real World ◽  
Therapy Group ◽  
Oral Anticoagulants ◽  
Inappropriate Drug ◽  
Nonvalvular Atrial Fibrillation ◽  
Prescription Patterns ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

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.

Processing by the human visual system of the light and dark contrast components of the retinal image

1977 ◽  
Vol 27 (4) ◽  
pp. 189-197 ◽  
Author(s):  
G. J. Burton ◽  
S. Nagshineh ◽  
K. H. Ruddock
Keyword(s):  
Visual System ◽  
Human Visual System ◽  
Retinal Image ◽  
Dark Contrast

Cutting or Round-Bodied Needles for Tendon Repair

2003 ◽  
Vol 28 (5) ◽  
pp. 475-477 ◽  
Author(s):  
W. L. LAM ◽  
A. GARRIDO ◽  
J. VANDERMEULEN ◽  
M. J. FAGAN ◽  
P. R. W. STANLEY
Keyword(s):  
Tensile Strength ◽  
Tendon Repair ◽  
Biomechanical Study ◽  
Suture Repair ◽  
Longitudinal Stress ◽  
The Core ◽  
Group 3 ◽  
Group 2 ◽  
Repair Group ◽  
Group 1

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.

Retinal image enhancement based on the human visual system

2006 ◽  
Author(s):  
Kamel Belkacem-Boussaid ◽  
Balaji Raman ◽  
Gilberto Zamora ◽  
Yeshwanth Srinivasan ◽  
Sven-Erick Bursell
Keyword(s):  
Visual System ◽  
Image Enhancement ◽  
Human Visual System ◽  
Retinal Image

scholarly journals O10 Characteristics of patients who discontinued baricitinib treatment within 12 months and reasons for discontinuation: real-world data

Rheumatology ◽  
2021 ◽  
Vol 60 (Supplement_1) ◽  
Author(s):  
May Nwe Lwin ◽  
Christopher Holroyd ◽  
Christopher J Edwards
Keyword(s):  
Combination Therapy ◽  
Real World ◽  
Personality Change ◽  
University Hospital ◽  
P Value ◽  
Real World Setting ◽  
Advanced Therapy ◽  
Significant Difference ◽  
Group 2 ◽  
Group 1

Abstract Background/Aims  Baricitinib is an oral targeted synthetic disease-modifying anti-rheumatic drug (tsDMARD) recommended by the National Institute for Health and Care Excellence (NICE) in the UK for severe rheumatoid arthritis (RA) either as mono- or combination therapy. We wanted to observe the frequency of discontinuation in a real-world setting, the characteristics of patients who stop taking baricitinib, and the reasons for discontinuation. Objective: To describe the characteristics of patients who discontinue baricitinib treatment and the reasons for discontinuation. Methods  A real-world retrospective observational study of baricitinib use in RA patients at University Hospital Southampton using local advanced therapy database for data collection. We described the characteristics of patients discontinuing baricitinib therapy and divided patients into two groups. Group 1 (those who discontinued therapy within the first 12 months of use) and group 2 (who continued therapy beyond 12 months) Results  From October 2017 to July 2020, a total of 83 patients started baricitinib and were recorded in the database, 55 (66.27%) remain on treatment to date. Among 28 (33.74%) patients who stopped baricitinib, 21 had stopped within 12 months. The reasons for discontinuation were lack of efficacy (64.28%) and AEs (28.57% - 1 tooth infection, 1 urinary tract infection, 1 discitis, 2 chest infection, 1 personality change, 1 deranged liver function and 1 lymphoma). In group 1, the mean (±SD) age was 49.00 (13.65) years, 66.67% were female and 85.71% were previously biologic inadequate responders (IR), 42.86% were receiving monotherapy, with 57.14% being on combination therapy with a csDMARD and 9.52% were using a glucocorticoid. In group 2, 82.26% were female, 61.52 (10.94) years of age and 83.87% were previously biologic IR, 41.94% were on monotherapy and 58.06% on combination therapy with a csDMARD. Patients who discontinued appeared more likely to be younger and male. However, there was no significant difference regarding mono- or combination therapy, disease duration or seropositivity (p-value &gt; 0.05) (Table 1). Conclusion  In a real-world setting, baricitinib appears efficacious and well-tolerated in the first year of use by two-thirds of patients. Characteristics such as older age and female gender were associated with continued use. Disclosure  M. Lwin: None. C. Holroyd: Honoraria; Lily. Member of speakers’ bureau; Lily. C.J. Edwards: Honoraria; Abbvie, Biogen, BMS, Celgene, Fresenius, GSK, Janssen, Lilly, Mundipharma, Pfizer, Roche, Sanofi, UCB. Member of speakers’ bureau; Abbvie, Biogen, BMS, Celgene, Janssen, Lilly, Sanofi, Pfizer, Roche. Grants/research support; Abbvie, Biogen, Pfizer.

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