List Of Pairs Research Articles

Differential online and offline effects of theta-tACS on memory encoding and retrieval

Theta oscillations support memory formation, but their exact contribution to the communication between prefrontal cortex (PFC) and the hippocampus is unknown. We tested the functional relevance of theta oscillations as a communication link between both areas for memory formation using transcranial alternating current stimulation (tACS). Healthy, young participants learned two lists of Dutch-German word pairs and retrieved them immediately and with a 30-min delay. In the encoding group (N = 30), tACS was applied during the encoding of list 1. List 2 was used to test stimulation aftereffects. In the retrieval group (N = 23), we stimulated during the delayed recall. In both groups, we applied tACS bilaterally at prefrontal and tempo-parietal sites, using either individualized theta frequency or 15 Hz (as control), according to a within-subject design. Stimulation with theta-tACS did not alter overall learning performance. An exploratory analysis revealed that immediate recall improved when word-pairs were learned after theta-tACS (list 2). Applying theta-tACS during retrieval had detrimental effects on memory. No changes in the power of the respective frequency bands were observed. Our results do not support the notion that impacting the communication between PFC and the hippocampus during a task by bilateral tACS improves memory. However, we do find evidence that direct stimulation had a trend for negatively interfering effects during immediate and delayed recall. Hints for beneficial effects on memory only occurred with aftereffects of the stimulation. Future studies need to further examine the effects during and after stimulation on memory formation.

Choices of measures of association affect the visualisation and composition of the multimorbidity networks

BackgroundNetwork analysis, commonly used to describe the patterns of multimorbidity, uses the strength of association between conditions as weight to classify conditions into communities and calculate centrality statistics. Our aim was to examine the robustness of the results to the choice of weight.MethodsData used on 27 chronic conditions listed on Australian death certificates for women aged 85+. Five statistics were calculated to measure the association between 351 possible pairs: odds ratio (OR), lift, phi correlation, Salton cosine index (SCI), and normalised-joint frequency of pairs (NF). Network analysis was performed on the 10% of pairs with the highest weight according to each definition, the ‘top pairs’.ResultsOut of 56 ‘top pairs’ identified, 13 ones were consistent across all statistics. In networks of OR and lift, three of the conditions which did not join communities were among the top five most prevalent conditions. Networks based on phi and NF had one or two conditions not part of any community. For the SCI statistics, all three conditions which did not join communities had prevalence below 3%. Low prevalence conditions were more likely to have high degree in networks of OR and lift but not SCI.ConclusionUse of different statistics to estimate weights leads to different networks. For exploratory purposes, one may apply alternative weights to identify a large list of pairs for further assessment in independent studies. However, when the aim is to visualise the data in a robust and parsimonious network, only pairs which are selected by multiple statistics should be visualised.

Age-related differences in metacognitive reactivity in younger and older adults

When we monitor our learning, often measured via judgments of learning (JOLs), this metacognitive process can change what is remembered. For example, prior work has demonstrated that making JOLs enhances memory for related, but not unrelated, word pairs in younger adults. In the current study, we examined potential age-related differences in metacognitive reactivity. Younger and older adults studied lists of related and unrelated word pairs to remember for a later cued recall test where they would be presented with one of the words from the pair and be asked to recall its associate. Additionally, participants either made a JOL for each pair or had an inter-stimulus interval of equal duration as the JOL period. Results revealed that while making metacognitive judgments did not significantly affect memory in younger adults (i.e., no reactivity), this procedure impaired memory in older adults (i.e., negative reactivity), particularly for unrelated word pairs. Specifically, older adults demonstrated better cued recall when each word was followed by an inter-stimulus interval than when asked to predict the likelihood of remembering each word during the study phase. This may be a consequence of JOLs increasing task demands/cognitive load, which could reduce the elaborative encoding of associations between word pairs in older adults, but older adults’ preserved or even enhanced semantic memory may mask negative reactivity for related word pairs. Future work is needed to better understand the mechanisms contributing to the reactivity effects in younger and older adults for different types of to-be-remembered information.

An algorithm for decoy-free false discovery rate estimation in XL-MS/MS proteomics.

Cross-linking tandem mass spectrometry (XL-MS/MS) is an established analytical platform used to determine distance constraints between residues within a protein or from physically interacting proteins, thus improving our understanding of protein structure and function. To aid biological discovery with XL-MS/MS, it is essential that pairs of chemically linked peptides be accurately identified, a process that requires: (i) database search, that creates a ranked list of candidate peptide pairs for each experimental spectrum and (ii) false discovery rate (FDR) estimation, that determines the probability of a false match in a group of top-ranked peptide pairs with scores above a given threshold. Currently, the only available FDR estimation mechanism in XL-MS/MS is the target-decoy approach (TDA). However, despite its simplicity, TDA has both theoretical and practical limitations that impact the estimation accuracy and increase run time over potential decoy-free approaches (DFAs). We introduce a novel decoy-free framework for FDR estimation in XL-MS/MS. Our approach relies on multi-sample mixtures of skew normal distributions, where the latent components correspond to the scores of correct peptide pairs (both peptides identified correctly), partially incorrect peptide pairs (one peptide identified correctly, the other incorrectly), and incorrect peptide pairs (both peptides identified incorrectly). To learn these components, we exploit the score distributions of first- and second-ranked peptide-spectrum matches for each experimental spectrum and subsequently estimate FDR using a novel expectation-maximization algorithm with constraints. We evaluate the method on ten datasets and provide evidence that the proposed DFA is theoretically sound and a viable alternative to TDA owing to its good performance in terms of accuracy, variance of estimation, and run time. https://github.com/shawn-peng/xlms.

The Moduli Space of Cyclic Covers in Positive Characteristic

Abstract We study the $p$-rank stratification of the moduli space $\operatorname{\mathcal{A}\mathcal{S}\mathcal{W}}_{(d_{1},d_{2},\ldots ,d_{n})}$, which represents $\mathbb{Z}/p^{n}$-covers in characteristic $p>0$ whose $\mathbb{Z}/p^{i}$-subcovers have conductor $d_{i}$. In particular, we identify the irreducible components of the moduli space and determine their dimensions. To achieve this, we analyze the ramification data of the represented curves and use it to classify all the irreducible components of the space. In addition, we provide a comprehensive list of pairs $(p,(d_{1},d_{2},\ldots ,d_{n}))$ for which $\operatorname{\mathcal{A}\mathcal{S}\mathcal{W}}_{(d_{1},d_{2},\ldots ,d_{n})}$ in characteristic $p$ is irreducible. Finally, we investigate the geometry of $\operatorname{\mathcal{A}\mathcal{S}\mathcal{W}}_{(d_{1},d_{2},\ldots ,d_{n})}$ by studying the deformations of cyclic covers that vary the $p$-rank and the number of branch points.

Does testing potentiate new learning because it enables learners to use better strategies?

Testing can potentiate new learning, which is often called the forward testing effect. One potential explanation for this benefit is that testing might enable participants to use more effective learning strategies subsequently. We investigated this possibility by asking participants to report their encoding strategies in a multi-list foreign language learning paradigm with four preregistered experiments and one non-preregistered pilot experiment. In Experiments 1-3, participants learned three lists of Chinese-English pairs; one group took a test after every list (i.e., test condition) and the other group took a test only for the criterial List 3 (i.e., restudy condition). In addition, participants completed a transfer test and a study strategy survey. Although we found a forward testing effect in all experiments, participants in the test and restudy conditions did not report differences in strategies. In Experiments 4 and 5, we used a within-subject design so that we could correlate changes in strategy use with the magnitude of the forward testing effect on an individual level. Interestingly, individual differences in strategy change were moderately associated with the magnitude of the forward testing effect, but even here, strategy change did not mediate the effect of testing on performance. Overall, our data showed that, at least for foreign language learning of Chinese characters, interim testing did not enhance new learning by altering participants' subsequent encoding strategies. Moreover, our data showed that interim testing did not promote the transfer of Chinese language learning to novel characters. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Gene selection for genomic newborn screening: Moving toward consensus?

PurposeGene selection for genomic newborn screening (gNBS) underpins the validity, acceptability, and ethical application of this technology. Existing gNBS gene lists are highly variable despite being based on shared principles of gene-disease validity, treatability, and age of onset. This study aimed to curate a gNBS gene list that builds upon existing efforts and provide a core consensus list of gene-disease pairs assessed by multiple expert groups worldwide. MethodsOur multidisciplinary expert team curated a gene list using an open platform and multiple existing curated resources. We included severe treatable disorders with age of disease onset <5 years with established gene-disease associations and reliable variant detection. We compared the final list with published lists from 5 other gNBS projects to determine consensus genes and to identify areas of discrepancy. ResultsWe reviewed 1279 genes and 604 met our inclusion criteria. Metabolic conditions comprised the largest group (25%), followed by immunodeficiencies (21%) and endocrine disorders (15%). We identified 55 consensus genes included by all 6 gNBS research projects. Common reasons for discrepancy included variable definitions of treatability and strength of gene-disease association. ConclusionWe have identified a consensus gene list for gNBS that can be used as a basis for systematic harmonization efforts internationally.

Efficient enumeration and visualization of helix-coil ensembles

Helix-coil models are routinely used to interpret circular dichroism data of helical peptides or predict the helicity of naturally-occurring and designed polypeptides. However, a helix-coil model contains significantly more information than mean helicity alone, as it defines the entire ensemble—the equilibrium population of every possible helix-coil configuration—for a given sequence. Many desirable quantities of this ensemble are either not obtained as ensemble averages or are not available using standard helicity-averaging calculations. Enumeration of the entire ensemble can allow calculation of a wider set of ensemble properties, but the exponential size of the configuration space typically renders this intractable. We present an algorithm that efficiently approximates the helix-coil ensemble to arbitrary accuracy by sequentially generating a list of the M highest populated configurations in descending order of population. Truncating this list of (configuration, population) pairs at a desired accuracy provides an approximating sub-ensemble. We demonstrate several uses of this approach for providing insight into helix-coil ensembles and folding mechanisms, including landscape visualization.

Contrastive Alveolar/Retroflex Phonemes in Singapore Mandarin Bilinguals: Comprehension Rates for Articulations in Different Accents, and Acoustic Analysis of Productions.

The standard Beijing variety of Mandarin has a clear alveolar-retroflex contrast for phonemes featuring voiceless sibilant frication (i.e., /s/, /ʂ/, /ʈs/, /ʈʂ/, /ʈsʰ/, /ʈʂʰ/). However, some studies show that varieties in the 'outer circle', such in Taiwan, have a reduced contrast for these speech sounds via a process known as 'deretroflexion'. The variety of Mandarin spoken in Singapore is also considered as 'outer circle', as it exhibits influences from Min Nan varieties. We investigated how bilinguals of Singapore Mandarin and English perceive and produce speech tokens in minimal pairs differing only in the alveolar/retroflex place of articulation. In all, 50 participants took part in two tasks. In Task 1, participants performed a lexical identification task for minimal pairs differing only the alveolar/retroflex place of articulation, as spoken by native speakers of two varieties: Beijing Mandarin and Singapore Mandarin. No difference in comprehension of the words was observed between the two varieties indicating that both varieties contain sufficient acoustic information for discrimination. In Task 2, participants read aloud from the list of minimal pairs while their voices were recorded. Acoustic analysis revealed that the phonemes do indeed differ acoustically in terms of center of gravity of the frication and in an alternative measure: long-term averaged spectra. The magnitude of this difference appears to be smaller than previously reported differences for the Beijing variety. These findings show that although some deretroflexion is evident in the speech of bilinguals of the Singaporean variety of Mandarin, it does not translate to ambiguity in the speech signal.

Testing can enhance episodic memory updating in younger and older adults.

Older adults sometimes show impaired memory for recent episodes, especially those that are similar but not identical to existing memories. Two experiments examined if interpolated testing between episodes improves recent memories for older and younger adults (N = 60 per group and experiment). Participants studied two lists of cue-response word pairs. Some pairs included the same cue in both lists with changed responses. Between lists, List 1 pairs were tested (Experiments 1 and 2), tested with corrective feedback (Experiment 1 only), or restudied (Experiment 2 only). On a final cued recall test, participants attempted to recall the List 2 response, indicated if responses had changed between lists, and if so, attempted to recall the List 1 response. List 2 recalls for changed pairs operationalized episodic memory updating. Older adults showed poorer List 2 recall than younger adults. But both age groups showed improved List 2 recall following interpolated testing with or without feedback compared to no-test and restudy contrast conditions. This so-called forward testing effect was accompanied by improved memory for responses having changed across lists. These results contrast with the inhibitory deficit proposal that older adults should be more interference prone than younger adults when competing responses are more accessible during encoding. These findings are more compatible with the view that retrieval practice of competing responses can support the encoding of cross-episode associations and potentially mitigate interference, thus improving age-related associative memory deficits. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Teaching older adults to use retrieval practice improves their self-regulated learning

ABSTRACT Retrieval practice can reduce associative memory deficits for older adults but they underutilize this potent learning tool during self-regulated learning. The current experiment investigated whether teaching older adults to use retrieval practice more can improve their self-regulated learning. Younger and older adults made decisions about when to study, how often to engage in retrieval practice, and when to stop learning a list of medication-side effect pairs. Some younger and older adults received instructions before learning that emphasized the mnemonic benefits of retrieval practice over restudying material and described how to schedule retrieval practice to learn to a goal criterion level. This minimal intervention was effective for improving both younger and older adults’ associative memory. These data indicate that a simple strategy for improving older adults self-regulated learning is to provide them with instructions that teach them how to use criterion learning to schedule their retrieval practice for to-be learned material.

Using graph-colouring to organise multi-version assessments

We describe and evaluate a method to mitigate unwanted student collaborations in assessments, which we recently implemented in a second-year undergraduate mathematics module. The method requires a list of specific pairs of students to be prevented from collaborating, which we constructed based on the results of previous assessments. We converted the list into an undirected graph – in which vertices represent students and adjacent vertices represent pairs of students to be prevented from collaborating – and determined a proper colouring of this graph. Subsequently, we designed multi-version assessments, the number and the distribution of the versions being as prescribed by the proper colouring. To assess this method's effectiveness, we conducted an anonymous survey collecting the students' opinions. The results showed that the method indeed reduced collaborations, and that it did so more significantly in the case of quizzes than take-home assignments.

Detecting compromised email accounts via login behavior characterization

The illegal use of compromised email accounts by adversaries can have severe consequences for enterprises and society. Detecting compromised email accounts is more challenging than in the social network field, where email accounts have only a few interaction events (sending and receiving). To address the issue of insufficient features, we propose a novel approach to detecting compromised accounts by combining time zone differences and alternate logins to identify abnormal behavior. Based on this approach, we propose a compromised email account detection framework that relies on widely available and less sensitive login logs and does not require labels. Our framework characterizes login behaviors to identify logins that do not belong to the account owner and outputs a list of account-subnet pairs ranked by their likelihood of having abnormal login relationships. This approach reduces the number of account-subnet pairs that need to be investigated and provides a reference for investigation priority. Our evaluation demonstrates that our method can detect most email accounts that have been accessed by disclosed malicious IP addresses and outperforms similar research. Additionally, our framework has the capability to uncover undisclosed malicious IP addresses.

Interpolated retrieval retroactively increases recall and promotes cross-episode memory interdependence.

Retrieving existing memories before new learning can lead to retroactive facilitation. Three experiments examined whether interpolated retrieval is associated with retroactive facilitation and memory interdependence that reflects integrative encoding. Participants studied two lists of cue-response word pairs that repeated across lists (A-B, A-B), appeared in list 1 (A-B, -), or included the same cues with changed responses in each list (A-B, A-C). For A-B, A-C pairs, the tasks interpolated between lists required recall of list 1 (B) responses (with or without feedback) or restudy of complete list 1 (A-B) pairs. In list 2, participants only studied pairs (experiment 1) or studied pairs, attempted to detect changed (C) responses, and attempted to recall list 1 responses for detected changes (experiments 2 and 3). On a final cued recall test, participants attempted to recall list 1 responses, indicated whether responses changed between lists, and if so, attempted to recall list 2 responses. Interpolated retrieval was associated with subsequent retroactive facilitation and greater memory interdependence for B and C responses. These correlational findings are compatible with the view that retrieval retroactively facilitates memories, promotes coactivation of existing memories and new learning, and enables integrative encoding that veridically binds information across episodes.

False Memory Facilitation Through Semantic Overlap.

This study investigated the effects of semantic overlap from multiple sources on false memories. Participants were presented with paired study lists comprising items highly associated with one nonstudied critical item. There were three types of list pairs: (1) the sharing condition, in which the words in both lists were classified into different semantic groups that converged on the same critical word (semantic overlap), (2) the repetition condition, in which the two lists comprised identical words, and (3) the single condition, in which the paired lists were attributed to different semantic groups that did not share a critical item. In Experiment 1, participants were presented with the paired study lists and responded to free recall tests and a recognition test including remember-know judgments. In Experiment 2, the participants responded to a recognition test, and the participants in Experiment 3 recalled the studied items. The results indicated that the false recall and false recognition rates in the sharing condition were higher than those in the repetition and single conditions. These results suggest that activation from multiple independent sources may have an accumulative additive effect. The findings are discussed in relation to the Activation-Monitoring theory.

Linguistic Analysis of Generic-Generic Drug Name Pairs Prone to Wrong-Drug Errors for which Tall-Man Lettering is Recommended

ObjectiveThe Institute for Safe Medication Practices (ISMP) and the United States Food and Drug Administration (FDA) disseminated widely used lists of drug name pairs involved in wrong-drug errors, for which they recommended tall-man lettering (TML). Linguistic similarity is believed responsible for confusion of these drugs. This study aims to quantify linguistic similarity and other linguistic properties of these generic-generic name pairs.MethodsThe FDA’s Phonetic and Orthographic Computer Analysis (POCA) software was used to generate numerical similarity scores for the generic-generic name pairs on these lists and to identify conflicts between these names and the names of other marketed products. Within each pair, differences in name length and the number of identical prefix (initial) letters and suffix (final) letters were determined.ResultsThe selected pairs shared a mean of 2.5 (± 1.8) identical prefix letters and 3.2 (± 2.9) identical suffix letters. The mean POCA score 69.5 (± 9.7), indicated moderate-to-high similarity. POCA scores for individual pairs ranged from 90 (most similar) to 46 (least similar). Individual names averaged 11.2 (± 9.1) high-similarity conflicts with names of other marketed drugs.ConclusionsPOCA analysis could be a valuable tool in determining whether linguistic similarity contributes to specific wrong-drug errors. The finding of 11.2 (± 9.1) high-similarity conflicts with names of other marketed drugs is more than for candidate names USAN accepts and suggests the names on the FDA and ISMP lists are linguistically problematic.

Symbolic forms and cognition

Two shapes - a cire le and a square - are used to study the effects of form symbolism in cognitive tasks. The first experiment examines the degree of consensus between subjects matching a list of pairs of words with the pair of shapes. The second experiment examines the correlation between the degree of consensus and the reaction times required in the matching task. The third experiment examines the effect of the consensus on performance on a recall task. The findings indicate there is significant consensus between subjects in tasks assessing form symbolism, the amount of consensus predicts reaction time on the matching task and the amount of consensus also predicts performance on the memory task.

Digenic Analysis Finds Highly Interactive Genetic Variants Underlying Polygenic Traits.

We briefly review our recently published approach to mining digenic genotype patterns, which consist of two genotypes each originating in a different DNA variant. We do this for a genetic case-control study by evaluating all possible pairs of genotypes, distributing the workload over numerous CPUs (threads) in a high-performance computing environment and apply our methods to two known datasets, age-related macular degeneration (AMD) and Parkinson Disease (PD). Based on a list of (e.g., 100,000) genotype pairs with largest genotype pair frequency differences between cases and controls, we determine the number of unique variants occurring in this list. For each unique variant, we find the number of genotype pairs it participates in, which identifies a set of variants "connected" with the given unique variant. Among the total of variants "connected" with all unique variants, only a subset of variants is unique. The ratio of all connected variants divided by that subset of variants is a measure for the overall density or connectedness of variants interacting with each other. We find that variants for the AMD data are much more interconnected than those for PD, at least based on the 100,000 genotype pairs with largest chi-square we investigated. Further, for each of the unique variants, we use the number of variants connected with it as a test statistic, weighted by the inverse of the rank at which the unique variant first occurred in the original list of genotype patterns. This weighing scheme ties the number of connections to the genetics of the trait and allows us to obtain, for each of the unique variants, an empirical significance level by permuting ranks. We find 12 and 8 significant, highly connected variants for AMD and PD, respectively, some of which have previously been identified by other machine learning methods, thus providing credence to our approach. Among the 100,000 genotype pairs investigated for each of AMD and PD, significant variants showed connections with up to 7,093 and 3,777 other variants, respectively. Our approach has been implemented in a freely available piece of software, the Digenic Network Test. Thus, our statistical genetics method can provide important information on the genetic architecture of polygenic traits.

Collision detection for N-body Kepler systems

Context. In a Keplerian system, a large number of bodies orbit a central mass. Accretion disks, protoplanetary disks, asteroid belts, and planetary rings are examples. Simulations of these systems require algorithms that are computationally efficient. The inclusion of collisions in the simulations is challenging but important. Aims. We intend to calculate the time of collision of two astronomical bodies in intersecting Kepler orbits as a function of the orbital elements. The aim is to use the solution in an analytic propagator (N-body simulation) that jumps from one collision event to the next. Methods. We outline an algorithm that maintains a list of possible collision pairs ordered chronologically. At each step (the soonest event on the list), only the particles created in the collision can cause new collision possibilities. We estimate the collision rate, the length of the list, and the average change in this length at an event, and study the efficiency of the method used. Results. We find that the collision-time problem is equivalent to finding the grid point between two parallel lines that is closest to the origin. The solution is based on the continued fraction of the ratio of orbital periods. Conclusions. Due to the large jumps in time, the algorithm can beat tree codes (octree and k-d tree codes can efficiently detect collisions) for specific systems such as the Solar System with N &lt; 108. However, the gravitational interactions between particles can only be treated as gravitational scattering or as a secular perturbation, at the cost of reducing the time-step or at the cost of accuracy. While simulations of this size with high-fidelity propagators can already span vast timescales, the high efficiency of the collision detection allows many runs from one initial state or a large sample set, so that one can study statistics.

ВОЗМОЖНОСТИ И ПЕРСПЕКТИВЫ СОЗДАНИЯ ПЭТ-ЦЕНТРОВ В РОССИИ НА ОСНОВЕ ГЕНЕРАТОРНЫХ РАДИОНУКЛИДОВ

An assessment of the capabilities of generator radionuclides and a list of generator pairs of radionuclides whose daughter isotope has the potential to be used in medicine for PET research is given. A list of typical 68Ga-based PET radiopharmaceuticals for oncology studied in preclinical and clinical studies is provided. Data on the use of the 82Sr/82Rb generator in clinical diagnostics are presented. The assessment of the existing situation with PET centers in Russia is given. A strategy for the development of a network of clinical PET centers and an overview of the state of generator technologies in Russia are proposed. This article concludes that the use of generators makes it possible to significantly expand the range of clinical institutions capable of providing PET diagnostics and conducting PET studies, having only 1 or several PET scanners in the clinic. It is concluded that due to a serious reduction in capital investments (by 1.5 times) and a noticeable reduction in the cost of operation (by 1.5‒2 times), the use of generator systems will significantly reduce the cost of many PET diagnostic procedures in oncology and cardiology, make this method more accessible to a wide range of the country’s population.