It is commonly believed that visual short-term memory (VSTM) consists of a fixed number of "slots" in which items can be stored. An alternative theory in which memory resource is a continuous ...quantity distributed over all items seems to be refuted by the appearance of guessing in human responses. Here, we introduce a model in which resource is not only continuous but also variable across items and trials, causing random fluctuations in encoding precision. We tested this model against previous models using two VSTM paradigms and two feature dimensions. Our model accurately accounts for all aspects of the data, including apparent guessing, and outperforms slot models in formal model comparison. At the neural level, variability in precision might correspond to variability in neural population gain and doubly stochastic stimulus representation. Our results suggest that VSTM resource is continuous and variable rather than discrete and fixed and might explain why subjective experience of VSTM is not all or none.
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We measured the precision with which an irrelevant feature of a relevant object is stored in visual short-term memory. In each experiment, 600 online subjects each completed 30 trials in which the ...same feature (orientation or color) was relevant, followed by a single surprise trial in which the other feature was relevant. Pooling data across all subjects, we find in a delayed-estimation task but not in a change localization task that the irrelevant feature is retrieved, but with much lower precision than when the same feature is relevant: The irrelevant/relevant precision ratio was 3.8% for orientation and 20.4% for color.
A central question in the study of visual short-term memory (VSTM) has been whether its basic units are objects or features. Most studies addressing this question have used change detection tasks in ...which the feature value before the change is highly discriminable from the feature value after the change. This approach assumes that memory noise is negligible, which recent work has shown not to be the case. Here, we investigate VSTM for orientation and color within a noisy-memory framework, using change localization with a variable magnitude of change. A specific consequence of the noise is that it is necessary to model the inference (decision) stage. We find that (a) orientation and color have independent pools of memory resource (consistent with classic results); (b) an irrelevant feature dimension is either encoded but ignored during decision-making, or encoded with low precision and taken into account during decision-making; and (c) total resource available in a given feature dimension is lower in the presence of task-relevant stimuli that are neutral in that feature dimension. We propose a framework in which feature resource comes both in packaged and in targeted form.
We used a delayed-estimation paradigm to characterize the joint effects of set size (one, two, four, or six) and delay duration (1, 2, 3, or 6 s) on visual working memory for orientation. We ...conducted two experiments: one with delay durations blocked, another with delay durations interleaved. As dependent variables, we examined four model-free metrics of dispersion as well as precision estimates in four simple models. We tested for effects of delay time using analyses of variance, linear regressions, and nested model comparisons. We found significant effects of set size and delay duration on both model-free and model-based measures of dispersion. However, the effect of delay duration was much weaker than that of set size, dependent on the analysis method, and apparent in only a minority of subjects. The highest forgetting slope found in either experiment at any set size was a modest 1.14°/s. As secondary results, we found a low rate of nontarget reports, and significant estimation biases towards oblique orientations (but no dependence of their magnitude on either set size or delay duration). Relative stability of working memory even at higher set sizes is consistent with earlier results for motion direction and spatial frequency. We compare with a recent study that performed a very similar experiment.
In hardware verification, constrained random testing is used to cover the vast verification space efficiently. Verification engineers adjust testbench settings to guide test behavior. Since this ...method produces many tests, we can train a machine learning (ML) model with test outcome to identify tests with high probability of having bugs, leading to increase in testing efficiency. However, maintaining good model performance after deployment is challenging. The data types are heterogeneous, change over time, and have multiple interpretations. I developed a data-centric ML pipeline that preprocesses custom verification-specific data types automatically and enables tuning data preprocessing methods ("data tuning"). This ML pipeline is adaptive to changes in future data and thus increases deployment scalability and robustness. Real-world benchmark testing shows that data tuning with this pipeline improves model performance.
The objective of this study was to evaluate the functional properties of lactic acid bacteria (LAB) from kimchi, a traditional Korean fermented vegetable product generally consumed raw as a side-dish ...with practically every meal.
Twelve mild acid producing facultatively heterofermentative Lactobacillus strains were selected for their potential as starter cultures for fermentation of kimchi, and evaluated for their functional properties. Eleven strains were identified as
Lactobacillus sakei and one as
Lactobacillus plantarum. The strains identified as
L. sakei differed in some physiological features; of particular interest was the fact that 9 of these strains produced L(+) lactic acid from glucose in presence of acetate.
All strains were able to survive gastrointestinal conditions simulating stomach and duodenum passage. In addition, they showed higher adherence to HT-29 cells than
Lactobacillus rhamnosus GG, a commercial probiotic strain used worldwide. These strains also showed antimicrobial activity against a number of food-borne pathogens. Their ability to lower cholesterol was demonstrated by BSH (bile salt hydrolytic) activity, and cholesterol assimilation tests
in vitro. The results suggest the probiotic potential of these strains for use in kimchi fermentation.
► Twelve LAB strains from kimchi were investigated for their functional properties. ► Of 11 Lb. sakei strains, 9 produced L(+) lactic acid from glucose in presence of acetate.►All strains survived simulated gastrointestinal conditions. ► All strains showed BSH (bile salt hydrolytic) activity. ► Most strains showed higher adherence to HT-29 cells than Lb. rhamnosus GG.
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Photobiomodulation (PBM) has widely been used to effectively treat complications associated with cancer treatment, including oral mucositis, radiation dermatitis, and surgical wounds. However, the ...safety of PBM against cancer still needs to be validated as the effects of PBM on cancer cells and their mechanisms are unclear. The current study investigated the wavelength-dependent PBM effects by examining four different laser wavelengths (405, 532, 635, and 808 nm) on B16F10 melanoma tumor cells. In vitro tests showed that PBM with 808 nm promoted both proliferation and migration of B16F10 cells. In vivo results demonstrated that PBM with 808 nm significantly increased the relative tumor volume and promoted angiogenesis with overexpression of VEGF and HIF-1α. In addition, PBM induced the phosphorylation of factors closely related to cancer cell proliferation and tumor growth and upregulated the related gene expression. The current result showed that compared to the other wavelengths, 808 nm yielded a significant tumor-stimulating effect the malignant melanoma cancer. Further studies will investigate the in-depth molecular mechanism of PBM on tumor stimulation in order to warrant the safety of PBM for clinical cancer treatment.
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•PBM effects on malignant melanoma were investigated by using four laser wavelengths.•The 808 nm PBM significantly promoted the growth of B16F10 tumor.•PBM induced tumorigenesis by stimulating cell signaling pathway and gene expression.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
We aimed to evaluate the current nationwide trend, efficacy, safety, and quality of life (QoL) profiles of hormone treatment in real-world practice settings for prostate cancer (PCa) patients in ...Korea. A total of 292 men with any biopsy-proven PCa (TanyNanyMany) from 12 institutions in Korea were included in this multi-institutional, observational study of prospectively collected data. All luteinizing hormone-releasing hormone (LHRH) agonists were allowed to be investigational drugs. Efficacy was defined as (1) the rate of castration (serum testosterone ≤50 ng dl
) at 4-week visit and (2) breakthrough (serum testosterone >50 ng dl
after castration). Safety assessments included routine examinations for potential adverse events, laboratory tests, blood pressure, body weight, and bone mineral density (BMD, at baseline and at the last follow-up visit). QoL was assessed using the Expanded Prostate Cancer Index Composite-26 (EPIC-26). The most common initial therapeutic regimen was LHRH agonist with anti-androgen (78.0%), and the most commonly used LHRH agonist for combination and monotherapy was leuprolide (64.0% for combination and 58.0% for monotherapy). The castration and breakthrough rates were 78.4% and 6.6%, respectively. The laboratory results related to dyslipidemia worsened after 4 weeks of hormone treatment. In addition, the mean BMD T-score was significantly lower at the last follow-up (mean: -1.950) compared to baseline (mean: -0.195). The mean total EPIC-26 score decreased from 84.8 (standard deviation s.d.: 12.2) to 78.3 (s.d.: 8.1), with significant deterioration only in the urinary domain (mean: 23.5 at baseline and 21.9 at the 4-week visit). These findings demonstrate the nationwide trend of current practice settings in hormone treatment for PCa in Korea.
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