Visual Detection Test Research Articles

Rapid and Sensitive On-site Nucleic Acid Detection of Three Main Fusarium Pathogens of Maize Stalk Rot Based on RPA-CRISPR/Cas12a.

Maize stalk rot is a soil-borne disease that poses a serious threat to maize production worldwide, with the most significant cause being fungal stalk rot. The development of a visual and rapid detection method for the maize stalk rot pathogen is significant for its prompt and accurate identification, enhancing agricultural production efficiency, and implementing timely preventive measures. These measures will help safeguard the maize yield and quality, ultimately reducing agricultural losses. In this study, we aimed to develop an efficient method to detect maize stalk rot pathogens. We focused on three pathogenic fungi commonly found in maize-producing regions worldwide: Fusarium verticillioides, Fusarium proliferatum, and Fusarium graminearum. Based on TEF-1α, we developed a rapid detection technique using RPA-CRISPR/Cas12a, combined with test strips to develop an on-site rapid visual detection test for these pathogens. The method showed detection sensitivity for F. verticillioides, F. proliferatum, and F. graminearum within 20 min at concentrations of 7.8 pg/μL, 0.11 ng/μL, and 0.13 ng/μL, respectively. The sensitivity increased with increasing reaction time. Testing of field disease samples indicated that the method is effective in detecting nucleic acids obtained through crude extraction methods. In conclusion, we developed a visually rapid detection technology that does not rely on complex instruments and equipment for the on-site early detection of F. verticillioides, F. proliferatum, and F. graminearum in the field to implement effective control measures, ensuring stable and high maize yields.

Research on the nighttime visibility of white pavement markings

At night, clear pavement markings are essential for driver safety. Currently, markings visibility evaluation relies on the retroreflectivity, but the impact of line width is unclear. To quantify the impact of line width on visibility and to refine visibility evaluation methods, a driver visual detection experiment was designed using both qualitative and quantitative approaches. Twenty-four drivers of small vehicles were randomly recruited to participate in visual detection tests of a total of 54 white pavement markings (comprising 6 widths and 9 retroreflectivity levels) under the illumination of high beams, following the principle of using the “emergence point” as the critical state for assessing pavement marking visibility. This study indicated that widening pavement markings significantly enhances their visibility, particularly for markings with low retroreflectivity. A visibility evaluation model was established to quantify the impact of width and retroreflectivity on the visual distance of markings. The model confirms that widening markings can improve visibility, thereby reducing the required level of retroreflectivity. The research methodology and findings provide technical support for managers to more accurately assess nighttime safety visibility during pavement marking operation and maintenance.

Widespread frontoparietal fMRI activity is greatly affected by changes in criterion placement, not discriminability, during recognition memory and visual detection tests

Widespread frontoparietal activity is consistently observed in recognition memory tests that compare studied (“target”) versus unstudied (“nontarget”) responses. However, there are conflicting accounts that ascribe various aspects of frontoparietal activity to mnemonic evidence versus decisional processes. According to Signal Detection Theory, recognition judgments require individuals to decide whether the memory strength of an item exceeds an evidence threshold—the decision criterion—for reporting previously studied items. Yet, most fMRI studies fail to manipulate both memory strength and decision criteria, making it difficult to appropriately identify frontoparietal activity associated with each process. In the current experiment, we manipulated both discriminability and decision criteria across recognition memory and visual detection tests during fMRI scanning to assess how frontoparietal activity is affected by each manipulation. Our findings revealed that maintaining a conservative versus liberal decision criterion drastically affects frontoparietal activity in target versus nontarget response contrasts for both recognition memory and visual detection tests. However, manipulations of discriminability showed virtually no differences in frontoparietal activity in target versus nontarget response or item contrasts. Comparing across task domains, we observed similar modulations of frontoparietal activity across criterion conditions, though the recognition memory task revealed larger activations in both magnitude and spatial extent in these contrasts. Nonetheless, there appears to be some domain specificity in frontoparietal activity associated with the maintenance of a conservative versus liberal criterion. We propose that widespread frontoparietal activity observed in target versus nontarget contrasts is largely attributable to response bias where increased activity may reflect inhibition of a prepotent response, which differs depending on whether a person maintains a conservative versus liberal decision criterion.

Development of Hemagglutinin-Neuraminidase Homologous Peptides as Novel Promising Therapeutic Agents Against Peste des Petits Ruminants Virus.

The lack of specific antiviral therapy and complications associated with the existing peste des petits ruminants (PPR) vaccines accentuates the search of novel antiviral blocking agents in order to curtail the PPR infection at initial level. The synthetic hemagglutinin-neuraminidase (HN) homologous peptides may compete with the natural HN protein of PPR virus for binding to signaling lymphocytic activation molecule (SLAM) receptor, consequently, may disrupt peste des petits ruminants virus (PPRV) at entry level. Therefore, insilico analysis, synthesis, purification and subsequent characterization of HN homologous peptides were conducted in this study. The HN homologous peptides were synthesized by means of solid phase chemistry and were purified by reversed-phase-high performance liquid chromatography. The mass as well as sequence of HN homologous peptides were assessed by mass spectroscopy while its secondary structure was elucidated by circular dichroism spectroscopy. The binding (interaction) efficacy of HN homologous peptides with PPRV antibodies was assessed via indirect enzyme linked immunosorbent assay, visual detection test (red wine to purple), bathochromic shift under UV-Vis spectrophotometry and lateral flow immunochromatographic strip test. The antiviral properties and cytotoxicity of these peptides were also assessed in B95a cell line with changes in cytopathic effect and titer of PPRV (Sungri/96). The presence of green fluorescein isothiocyanate over the B95a cell surface pointed towards the binding of HN homologous peptides with surface SLAM receptor. Moreover, the intact beta sheet configuration in water and lower cytotoxicity [cytotoxic concentration 50 (CC50) > 1000µg/ml] of these peptides signifies its in vivo use. Among HN homologous peptides, the binding efficacy and antiviral properties of pep A was relatively high in comparison to pep B and Pep ppr peptides. The prerequisite concentration of HN homologous peptides (pep A = 12.5µg/ml; pep B = 25µg/ml; pep ppr = 25µg/ml) to exemplify its antiviral effect was much lower than its CC50 level. Hence, this study signifies the therapeutic potential of synthetic HN homologous peptides.

Who gives a criterion shift? A uniquely individualistic cognitive trait.

Individuals should strategically shift decision criteria when there are disproportionate likelihoods or consequences for falsely identifying versus missing target items. Despite being explicitly aware of the advantages for criterion shifting, people on average do not shift extremely, leading many theories to conclude that people are generally suboptimal at placing decision criteria. However, assessments of individual differences reveal that some people actually do criterion shift quite well while others fail to shift entirely. These individual differences may carry meaningful information about the nature and consistency of a person's decision-making strategies, but no studies have systematically assessed the stability of strategic criterion shifting within individuals over time. We assessed criterion shifting stability by administering test-retest recognition memory and visual detection tests where we induced decision biases through instruction, payoff, and base rate manipulations. Criterion shifting tendencies proved to be stable within and across decision domains regardless of the inducement. Individual differences in criterion shifting could not be explained by personality characteristics, metacognitive sensitivity, motivation, or performance on other cognitive tasks. Reports of confidence ratings, which are used to assess various criterion placements, showed no relationship to the extent of criterion shifting unless participants received instructions to make certain response types with high confidence only. Participants who inadequately shifted criteria still tended to set extreme criteria for reporting high confidence, suggesting that these individuals are capable of shifting to greater extents, but appear unwilling to do so. These findings demonstrate that strategic criterion shifting tendencies are a stable and uniquely individualistic cognitive trait. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Optimization of color design for military camouflage in CIELAB color space

AbstractThe assessment of military camouflage is a key consideration in the modern military field. Traditionally, the assessment relies on traditional human visual detection tests because a large scale multi‐level and multi‐factor experiments are time‐ and resource‐consuming. One aspect of camouflage assessment, to which this current study pertains, entails improving upon or “enhancing” an existing or “selected” design. The current study presents a new and practical approach for enhancing the selected military camouflage by utilizing response surface methodology (RSM) of %L*, %a*, and %b* in CIELAB color space. Ten participants were recruited to evaluate 35 variations of %L*, %a*, and %b* on camouflage similarity index (CSI) and reaction time (RT). Based on RSM, the optimum combination occurs at L*: 61.4966, a*: −5.6505, and b*: 10.5114. In addition, a predictive algorithm to calculate the optimum shift of %L*, %a*, and %b* from the original camouflage to the improved camouflage derived from RSM is also proposed. The optimum shift occurs at −25%L*, −55%a*, and + 80%b*. In the end, a new design guideline is proposed for the enhancement of selected military camouflage, which adopts the present study's research findings.

Comparison of Papanicolaou Test With Visual Detection Tests in Screening for Cervical Cancer and Developing the Optimal Strategy for Low Resource Settings

To compare the sensitivity, specificity, positive and negative predictive values, and accuracy of Papanicolaou test with visual inspection with acetic acid (VIA)/VIA using magnification devices (VIAM) and develop the best strategy for screening in low resource settings. This is a prospective cross-sectional study on 408 symptomatic multiparous women in the reproductive age group, sequentially using the Papanicolaou test, the VIA, and the VIAM for screening. Women with a positive screening test underwent guided biopsy and endocervical curettage. The site of biopsy was recorded. Histopathological findings were taken as the "gold" standard in comparing the methods. The mean (SD) age was 32.3 (6.8) years (range, 15-49 years), whereas the mean (SD) parity was 2.9 (1.2) (range, 1-9). Abnormal cytological findings were detected in 2.9% patients, whereas the remaining smears were negative for any intraepithelial lesion or malignancy. A total of 113 cases were screened positive by one/all methods. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the Papanicolaou test, the VIA, and the VIAM were 24, 98, 42, 96, and 94%; 95, 78, 19, 99, and 79%; and 95, 78, 19, 99, and 79%, respectively, for high-grade lesions. The Papanicolaou test had low sensitivity but high specificity, whereas visual detection methods had a high sensitivity in addition to being cheaper. Alternative methods of screening such as VIA/VIAM can be a valuable alternative to the Papanicolaou test for cervical cancer screening in low resource settings. Visual inspection using magnification devices may be of benefit over VIA in doubtful cases.

Effect of K-shell absorption edge filters on image quality in digital intraoral radiography.

The purpose of this study was to investigate the effects of K-shell absorption edge filters on the image quality of a charge-coupled device-based digital intraoral radiographic system. NIOBI-X, Dental X-ray Beam Filter Kit, and KEY filter were added to a 1-mm thick aluminum filter. The half-value layer and the corresponding effective energy were measured. Digital x-ray images were obtained by using a Computed Dental Radiography (CDR). The sensitivity and the image contrast were compared for each filter. Visual detection tests were conducted to evaluate the depiction ability by using 2 kinds of phantoms. The highest effective energy was produced with the KEY filter, and this high effective energy tended to increase the sensitivity of the CDR. The KEY filter also produced the greatest contrast and had the best depiction ability. The appropriate combination of a charge-coupled device-based digital intraoral radiographic system and an additional filter can reduce the patient dosage and increase the diagnostic information.

Newly designed phantom for visual detection tests of intra-oral x-ray imaging systems

A new phantom set, which consists of ten acrylic plate phantoms with several kinds of holes, was designed for visual detection tests of intra-oral x-ray imagin systems. Detection tests of two kinds of dental x-ray films were performed using three kinds of phantoms, an aluminum test object, Burger's phantom and the new phantom set. Detection-ability curves generated against optical density were compared. Moreover, correlation between the SNR (signal-to-noise ratio) factor and detection ability was analyzed. False positive rates were also compared. To reduce the number of phantom plate that had to be tested in the new phantom set, the number of detected signals for each phantom plate was cumulatively added and statistically compared to the total number of detected signals.

Circadian rhythm of luminance detectability in the rat

Rats lived in a visual detection test environment which allowed for around-the-clock measurement of the detectability of a 500 nm stimulus of low luminance. Daily trends in visual sensitivity were compared with a behavioral activity measure, the rate of trial initiations in the self-paced testing procedure. Both variables showed circadian rhythms with periods exceeding 24 hr in the absence of day-night cues. However, the two oscillations were phase-displaced, such that maximal visual sensitivity occurred earlier than did maximal behavioral activity, each day. The temporal organization of visual sensitivity may underlie well-known photic influences on circadian rhythms and photoperiodic behavior.