Visual computation of surface lightness: Local contrast vs. frames of reference

Seeing black, white and gray surfaces, called lightness perception, might seem simple because white surfaces reflect 90% of the light they receive while black surfaces reflect only 3%, and the human retina is composed of light sensitive cells. The problem is that, because illumination varies from time to time and from place to place, any amount of light can be reflected from any shade of gray. Thus the amount of light reflected by an object, called luminance, says nothing about its lightness. Experts agree that the lightness of a surface can be computed only by using the surrounding context, but they disagree about how the context is used. We have tested an image in which two major classes of theory, contrast theories and frame-of-reference theories, make very different predictions regarding what gray shades will be seen by human observers. We show that when frame-of-reference is varied while contrast is held constant, lightness varies strongly. But when contrast is varied but frame-of-reference is held constant, little or no variation is seen. These results suggest that efforts to discover the exact algorithm by which the human visual system segments the image received by the retina into frames of reference should be given high priority

Gender Representation in the Vision Sciences: A Longitudinal Study

Understanding the current status and historical trends of gender representation within a research field is an important component of fostering a diverse and inclusive scientific community. Here, we report on the gender representation of a large sample of the vision science research community—the attendees of the Annual Meeting of the Vision Sciences Society (VSS). Our analysis shows that the majority of scientists at all career levels in our sample are male. This imbalance is most pronounced for the senior scientists, whereas predoctoral students are nearly balanced between the genders. Historically, the gender imbalance was larger than it is at present, and it has followed a slow-but-steady trend toward gender parity over the past decade. A longitudinal analysis based on tracking individual attendees shows a larger dropout rate for female than male predoctoral trainees. However, among the trainees who continue in the vision science field after graduate school, evidence suggests that career advancement is quite similar between the genders. In an additional analysis, we found that the VSS Young Investigator awardees and the abstract review committee members reflect substantial gender imbalances, suggesting that these recognitions have yet to catch up with the greater gender balance of the rising generation of junior vision scientists. We hope that this report will encourage awareness of issues of diversity in the scientific community and further promote the development of a research field in which all talented scientists are supported to succeed

Antimicrobial Medicines Consumption in Eastern Europe and Central Asia - An Updated Cross-National Study and Assessment of Quantitative Metrics for Policy Action

<p>Introduction: Surveillance of antimicrobial medicines consumption is central to improving their use and reducing resistance rates. There are few published data on antibiotic consumption in Eastern Europe and Central Asia. To address this, 18 non-European Union (EU) countries and territories contribute to the WHO Regional Office for Europe (WHO Europe) Antimicrobial Medicines Consumption (AMC) Network.</p><p>Objectives: (i) Analyze 2015 consumption of J01 class antibacterials for systemic use from 16 AMC Network members; (ii) compare results with 2011 data and 2015 ESAC-Net estimates; (iii) assess consumption against suggested indicators; (iv) evaluate the impact of planned changes to defined daily doses (DDDs) in 2019 for some commonly used antibiotics; and (v) consider the utility of quantitative metrics of consumption for policy action.</p><p>Methods: Analysis methods are similar to ESAC-Net for EU countries. The Anatomical Therapeutic Chemical (ATC) classification and DDD methodology were used to calculate total consumption (DDD/1000 inhabitants/day [DID]), relative use measures (percentages), extent of use of WHO Watch and Reserve group antibiotics and impact of DDD changes.</p><p>Findings: Total J01 consumption in 2015 ranged 8.0–41.5 DID (mean 21.2 DID), generally lower than in 2011 (6.4–42.3 DID, mean 23.6 DID). Beta-lactam penicillins, cephalosporins, and quinolones represented 16.2–56.6, 9.4–28.8, and 7.5–24.6% of total J01 consumption, respectively. Third-generation cephalosporins comprised up to 90% of total cephalosporin consumption in some countries. Consumption of WHO Reserve antibiotics was very low; Watch antibiotics comprised 17.3–49.5% of total consumption (mean 30.9%). Variability was similar to 2015 ESAC-Net data (11.7–38.3 DID; mean 22.6 DID). DDD changes in 2019 impact both total and relative consumption estimates: total DIDs reduced on average by 12.0% (7.3–35.5 DID), mostly due to reduced total DDDs for commonly used penicillins; impact on rankings and relative use estimates were modest.</p><p>Discussion: Quantitative metrics of antibiotic consumption have value. Improvements over time reflect national activities, however, changes in total volumes may conceal shifts to less desirable choices. Relative use measures targeting antibiotics of concern may be more informative. Some, including WHO Watch and Reserve classifications, lend themselves to prescribing targets supported by guidelines and treatment protocols.</p

Judgement of paintings belonging to different tendencies in the 20th century painting

Prema hipotezi Lazara Trifunovića nastanak i razvoj modernih slikarskih pravaca može se pratiti kroz tri razvojne linije. Prvu (Sezan - kubizam - neoplasticizam - suprematizam) karakteriše intenzivno bavljenje formom i tendencija ka geometrizaciji. Drugu (Van Gog - ekspresionizam - apstraktni ekspresionizam/ enformel) odlikuje korišćenje boje kao osnovnog sredstva izražavanja. Treću (Gogen - fovizam) karakteriše simbolička upotreba boje i ukidanje perspektive. Istraživanje je imalo za cilj da utvrdi da li se slike koje pripadaju navedenim razvojnim linijama procenjuju kao međusobno slične na bazičnim dimenzijama subjektivnog doživljaja forme. Ove dimenzije čine faktori regularnosti, pobuđenosti i evaluacije i merene su instrumentom SDF 9. Ispitanici su procenjivali 15 reprodukcija, reprezentativnih za određeni slikarski pravac, na devet bipolarnih skala procene, koji konvergiraju u navedene tri dimenzije. Prema procenama ispitanika izlagane slike su se grupisale u četiri klastera: apstraktno-ekspresionistički (visoke procene na pobuđenosti, a niske na regularnosti), figuralno-ekspresionistički (slike procenjene kao niske na evaluaciji, više na regularnosti, a niže na pobuđenosti u odnosu na prethodni klaster), konstruktivistički (visoko regularne slike, niske na pobuđenosti) i realistični (slike visoko procenjene na sve tri dimenzije). Rezultati ukazuju da je, uz formalne (stilske) karakteristike slike, ključne za diskriminaciju trećeg od prva dva klastera (konstruktivizam vs. ekspresionizam) i sadržaj slike (apstraktan i neprepoznatljiv vs. figuralan i prepoznatljiv) važan faktor u proceni.In this study Trifunović’ hypothesis that there are three objective lines in the development of modern art was psychologically evaluated. According to Trifunović, in the first line (Cézanne - cubism - neoplasticism - suprematism) the geometrization of form prevails, in the second (Van Gogh - expressionism - abstract expressionism) the use of color is dominant, whereas the main features of the third line (Gauguin - fauvism) are symbolic use of color and reduction of perspective. Fifteen reproductions of paintings that represent the three developmental lines were used as stimuli. The subjects were asked to judge the stimuli on nine bipolar 7-step scales. These scales constitute the three factors of instrument SDF 9: Evaluation, Arousal and Regularity (3 scales x 3 factors = 9 scales). Four clusters of paintings were obtained: Abstract-expressionistic (moderate Evaluation, high Arousal and low Regularity), Figural-expressionistic (very low Evaluation, low Arousal and high Regularity), Constructivistic (moderate Evaluation, low Arousal and high Regularity) and Realistic (high Evaluation, high Arousal and high Regularity). The results partially confirm Trifunović’ hypothesis indicating that, besides the formal features, the content (abstract vs. figural) is also significant factor of subjective clustering of paintings