scholarly journals A Paradox in Digital Memory Assessment: Increased Sensitivity With Reduced Difficulty

2021 ◽  
Vol 3 ◽  
Author(s):  
Joshua P. White ◽  
Adrian Schembri ◽  
Chris J. Edgar ◽  
Yen Ying Lim ◽  
Colin L. Masters ◽  
...  

The One Card Learning Test (OCL80) from the Cogstate Brief Battery—a digital cognitive test used both in-person and remotely in clinical trials and in healthcare contexts to inform health decisions—has shown high sensitivity to changes in memory in early Alzheimer's disease (AD). However, recent studies suggest that OCL sensitivity to memory impairment in symptomatic AD is not as strong as that for other standardized assessments of memory. This study aimed to improve the sensitivity of the OCL80 to AD-related memory impairment by reducing the test difficultly (i.e., OCL48). Experiment 1 showed performance in healthy adults improved on the OCL48 while the pattern separation operations that constrain performance on the OCL80 were retained. Experiment 2 showed repeated administration of the OCL48 at short retest intervals did not induce ceiling or practice effects. Experiment 3 showed that the sensitivity of the OCL48 to AD-related memory impairment (Glass's Δ = 3.11) was much greater than the sensitivity of the OCL80 (Glass's Δ = 1.94). Experiment 4 used data from a large group of cognitively normal older adults to calibrate performance scores between the OCL80 and OCL48 using equipercentile equating. Together these results showed the OCL48 to be a valid and reliable test of learning with greater sensitivity to memory impairment in AD than the OCL80.

2021 ◽  
Author(s):  
Joshua Paul White ◽  
Adrian Schembri ◽  
Chris J. Edgar ◽  
Yen Ying Lim ◽  
Colin Masters ◽  
...  

The One Card Learning Test (OCL80) from the Cogstate Brief Battery has shown high sensitivity to changes in memory in early Alzheimer’s disease (AD), although recent studies suggest that OCL sensitivity to memory impairment in symptomatic AD is not as strong as that for other standardized assessments of memory. This study aimed to improve the sensitivity of the OCL80 to AD-related memory impairment by reducing the test difficultly (i.e., OCL48). Experiment 1 showed performance in healthy adults improved on the OCL48 while the pattern separation operations that constrain performance on the OCL80 were retained. Experiment 2 showed repeated administration of the OCL48 at short retest intervals did not induce ceiling or practice effects. Experiment 3 showed that the sensitivity of the OCL48 to AD-related memory impairment (Glass’s ∆ = 3.11) was much greater than the sensitivity of the OCL80 (Glass’s ∆ = 1.94). Experiment 4 used data from a large group of cognitively normal older adults to calibrate performance scores between the OCL80 and OCL48 using equipercentile equating. Together these results showed the OCL48 to be a valid and reliable test of learning with greater sensitivity to memory impairment in AD than the OCL80.


1987 ◽  
Vol 41 (1) ◽  
pp. 126-130 ◽  
Author(s):  
Scott D. Schwab ◽  
Richard L. McCreery

Fiber optics were used to interface a Raman spectrometer to a long (1 m) sample tube, with the objective being increased sensitivity. Internal reflection of the laser light and the Raman scatter within the sample tube permitted a long solution length to be sampled, increasing the Raman sensitivity by factors of 30–50 over conventional capillary tube sampling systems. In addition, the sample was subjected to much lower power densities than with systems employing a focused beam, thus minimizing radiation damage. Detection limits of 10−9 to 10−8 M were achieved for resonance Raman scatterers, and normal Raman scatterers could be detected at the 1 × 10−5 M level.


2002 ◽  
Vol 109 (3) ◽  
pp. 361-375 ◽  
Author(s):  
M. Hiramatsu ◽  
T. Yamatsu ◽  
T. Kameyama ◽  
T. Nabeshima

2013 ◽  
Vol 03 (08) ◽  
pp. 01-10
Author(s):  
Majid Delavari ◽  
Nadiya Gandali Ali khani ◽  
Esmaeil Naderi

Crude oil as one of the main sources of energy is also the main source of income for members of OPEC. So, the volatility of crude oil price is one of the main economic variables in the world and analysis of the effect of its changes on key economic factors has been always considered as significant. The reason might be the high sensitivity of oil price to political, economic and cultural issues worldwide and consequently its volatility on the one hand, and the high influence of the volatile prices on macroeconomic variables. On the other hand, for different reasons such as oil price volatilities and income from oil export, economic planners and policy makers in Iran have been mainly focused on the promotion of non-oil exports especially during the last few decades. Therefore, methanol as one of the most commonly used petrochemical products has a high potential for production and export of non-oil products in Iran. For this reason, in the present study there was an attempt to examine the relationship between the prices of Iran’s crude oil and methanol using FIGARCH model and based on the weekly time series data related to the research variables. The results of the study showed that the long memory parameter is equal to 0.32 which is meaning the shocks caused by volatility of methanol market and crude oil price to the methanol price were lasting and meaningful and were revealed in the long term.


NeuroImage ◽  
2001 ◽  
Vol 13 (6) ◽  
pp. 650
Author(s):  
Richard J. Clarke ◽  
Audra J. Parker ◽  
Elizabeth A. Kensinger ◽  
John H. Growdon ◽  
Suzanne Corkin

NANO ◽  
2019 ◽  
Vol 14 (07) ◽  
pp. 1950084 ◽  
Author(s):  
Jilong Wang ◽  
Siheng Su ◽  
Jingjing Qiu ◽  
Shiren Wang

In this paper, a novel and facile method to achieve fluorescent nanosized-diamond based nanowire (NW) is reported. One-dimensional (1D) organic NW has received tremendous attention due to its superior chemical functionality and size-, shape-, and material-dependent properties. In addition, nanosized-diamond is comprehensively studied and investigated due to superior tunable fluorescent properties, cost-effectiveness, facile manufacturing and high biocompatibility. Through thermal treatment, sulfur-modified nanosized-diamond was fabricated by mixing oxidized nanosized-diamond and dibenzyl disulfide at 900∘C. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and zeta potential were employed to characterize sulfur-modified nanosized-diamond. After that, porous anodic aluminum oxide template-assisted cathodic electrophoretic deposition method was used to achieve sulfur-modified nanosized-diamond NW. Scanning electron microscopy and transmission electron microscopy were applied to present the one-dimensional structure of the NWs. The optical properties of sulfur nanosized-diamond NW were characterized via ultraviolet-visible spectroscopy and photoluminescence spectroscopy. Finally, the as-synthesized sulfur-modified nanosized-diamond NW-based optical sensor was fabricated to detect vitamin B[Formula: see text] with high sensitivity and selectivity.


2009 ◽  
Vol 27 (31) ◽  
pp. 5144-5152 ◽  
Author(s):  
Claudine Legault ◽  
Pauline M. Maki ◽  
Susan M. Resnick ◽  
Laura Coker ◽  
Patricia Hogan ◽  
...  

Purpose To compare the effects of two selective estrogen receptor modulators, tamoxifen and raloxifene, on global and domain-specific cognitive function. Patients and Methods The National Surgical Adjuvant Breast and Bowel Project's Study of Tamoxifen and Raloxifene (STAR) study was a randomized clinical trial of tamoxifen 20 mg/d or raloxifene 60 mg/d in healthy postmenopausal women at increased risk of breast cancer. The 1,498 women who were randomly assigned in STAR were age 65 years and older, were not diagnosed with dementia, and were enrolled onto the Cognition in the Study of Tamoxifen and Raloxifene (Co-STAR) trial, beginning 18 months after STAR enrollment started. A cognitive test battery modeled after the one used in the Women's Health Initiative Study of Cognitive Aging (WHISCA) was administered. Technicians were centrally trained to administer the battery and recertified every 6 months. Analyses were conducted on all participants and on 273 women who completed the first cognitive battery before they started taking their medications. Results Overall, there were no significant differences in adjusted mean cognitive scores between the two treatment groups across visits. There were significant time effects across the three visits for some of the cognitive measures. Similar results were obtained for the subset of women with true baseline measures. Conclusion Tamoxifen and raloxifene are associated with similar patterns of cognitive function in postmenopausal women at increased risk of breast cancer. Future comparisons between these findings and patterns of cognitive function in hormone therapy and placebo groups in WHISCA should provide additional insights into the effects of tamoxifen and raloxifene on cognitive function in older women.


Author(s):  
Reinhard Bauer ◽  
Klaus Himpsl-Gutermann ◽  
Martin Sankofi ◽  
Petra Szucsich ◽  
Ruth Petz

Due to the rapid development of digital media, the work of researchers in all scientific disciplines has dramatically changed. The objective of this chapter is to give a brief overview of digital tools that can be used for action or practice research in the context of seamless learning. It is the intention of the authors to, on the one hand, provide some initial orientation and deeper insight into the complex subject matter of digital science. On the other hand, researchers shall be equipped with a user guide that encourages them to try out various digital tools for searching, collecting, annotating, analyzing, visualizing, interpreting as well as publishing information. Owing to the dynamic nature of the issue under review this chapter will undoubtedly only offer a snapshot.


Sensors ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 188 ◽  
Author(s):  
Debo Wei ◽  
Jianyu Fu ◽  
Ruiwen Liu ◽  
Ying Hou ◽  
Chao Liu ◽  
...  

Micro-Pirani vacuum sensors usually operate at hundreds of microwatts, which limits their application in battery-powered sensor systems. This paper reports a diode-based, low power consumption micro-Pirani vacuum sensor that has high sensitivity. Optimizations to the micro-Pirani vacuum sensor were made regarding two aspects. On the one hand, a greater temperature coefficient was obtained without increasing power consumption by taking advantage of series diodes; on the other hand, the sensor structure and geometries were redesigned to enlarge temperature variation. After that, the sensor was fabricated and tested. Test results indicated that the dynamic vacuum pressure range of the sensor was from 10−1 to 104 Pa when the forward bias current was as low as 10 μA with a power consumption of 50 μW. Average sensitivity was up to 90 μV/Pa and the sensitivity of unit power consumption increased to 1.8 V/W/Pa. In addition, the sensor could also work at a greater forward bias current for better sensor performance.


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