Process Dissociation Analyses of Memory Changes in Healthy Aging, Preclinical, and Very Mild Alzheimer Disease: Evidence for Isolated Recollection Deficits

Recollection and familiarity are independent processes that contribute to memory performance. Recollection is dependent on attentional control, which breaks down in early-stage Alzheimer disease (AD), whereas familiarity is independent of attention. The present study examines the sensitivity of recollection estimates based on Jacoby’s (1991) process dissociation procedure to AD-related biomarkers in a large sample of well-characterized cognitively normal older adults (N = 519) and the extent to which recollection discriminates these individuals from individuals with very mild symptomatic AD (N = 64). Participants studied word pairs, e.g., “knee bone,” then completed a primed, explicit, cued fragment-completion memory task, e.g., “knee b_n_.” Primes were either congruent with the correct response, e.g., “bone,” incongruent, e.g., “bend,” or neutral, e.g., “&&&.” This design allowed for the estimation of independent contributions of recollection and familiarity processes, using the process dissociation procedure. Recollection, but not familiarity, was impaired in healthy aging and in very mild AD. Recollection discriminated cognitively normal individuals from the earliest detectable stage of symptomatic AD above and beyond standard psychometric tests. In cognitively normal individuals, baseline CSF measures indicative of AD pathology were related to lower initial recollection and less improvement in recollection over time. Finally, presence of amyloid plaques, as imaged by PIB-PET, was related to less improvement in recollection over time. These findings suggest that attention-demanding memory processes, such as recollection, may be particularly sensitive to both symptomatic and preclinical AD pathology

Wakeful rest benefits recall, but not recognition, of incidentally encoded memory stimuli in younger and older adults

Older adults exhibit deficits in episodic memory tasks, which have often been attributed to encoding or retrieval deficits, with little attention to consolidation mechanisms. More recently, researchers have attempted to measure consolidation in the context of a behavioral experiment using the wakeful rest paradigm (i.e., a brief, quiet period of minimal stimulation, which facilitates memory performance, compared to a distractor task). Critically, older adults might not produce this effect, given established age differences in other episodic memory processes and mind-wandering. In three experiments, we directly compared younger and older adults in modified versions of the wakeful rest paradigm. Critically, we utilized incidental encoding procedures (all experiments) and abstract shape stimuli (in Experiment 3) to limit the possibility of retrieval practice or maintenance rehearsal as potential confounding mechanisms in producing the wakeful rest effect. Wakeful rest reliably and equally benefited recall of incidentally encoded words in both younger and older adults. In contrast, wakeful rest had no benefit for standard accuracy measures of recognition performance in verbal stimuli, although there was an effect in response latencies for non-verbal stimuli. Overall, these results suggest that the benefits of wakeful rest on episodic retrieval are preserved across age groups, and hence support age-independence in potential consolidation mechanisms as measured by wakeful rest. Further, these benefits do not appear to be dependent on the intentionality of encoding or variations in distractor task types. Finally, the lack of wakeful rest benefits on recognition performance might be driven by theoretical constraints on the effect or methodological limitations of recognition memory testing in the current paradigm

Evaluation of BacLite Rapid MRSA, a rapid culture based screening test for the detection of ciprofloxacin and methicillin resistant S. aureus (MRSA) from screening swabs

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide. The need for accurate and rapid screening methods to detect MRSA carriers has been clearly established. The performance of a novel assay, BacLite Rapid MRSA (Acolyte Biomedica, UK) for the rapid detection (5 h) and identification of hospital associated ciprofloxacin resistant strains of MRSA directly from nasal swab specimens was compared to that obtained by culture on Mannitol salt agar containing Oxacillin (MSAO) after 48 h incubation. RESULTS: A total of 1382 nasal screening swabs were tested by multiple operators. The BacLite Rapid MRSA test detected 142 out of the 157 confirmed MRSA that were detected on MSAO giving a diagnostic sensitivity of 90.4, diagnostic specificity of 95.7% and a negative predictive value of 98.7%. Of the 15 false negatives obtained by the BacLite Rapid MRSA test, seven grew small amounts (< 10 colonies of MRSA) on the MSAO culture plate and five isolates were ciprofloxacin sensitive. However there were 13 confirmed BacLite MRSA positive samples, which were negative by the direct culture method, probably due to overgrowth on the MSAO plate. There were 53 false positive results obtained by the BacLite Rapid MRSA test at 5 h and 115 cases where MRSA colonies were tentatively identified on the MSAO plate when read at 48 h, and which subsequently proved not to be MRSA. CONCLUSION: The Baclite MRSA test is easy to use and provides a similar level of sensitivity to conventional culture for the detection of nasal carriage of MRSA with the advantage that the results are obtained much more rapidly

Evaluating cognitive relationships with resting-state and task-driven blood oxygen level-dependent variability

Recent functional magnetic resonance imaging studies have reported that moment-to-moment variability in the blood oxygen level-dependent (BOLD) signal is positively associated with task performance and, thus, may reflect a behaviorally sensitive signal. However, it is not clear whether estimates of resting-state and task-driven BOLD variability are differentially related to cognition, as they may be driven by distinct sources of variance in the BOLD signal. Moreover, other studies have suggested that age differences in resting-state BOLD variability may be particularly sensitive to individual differences in cardiovascular, rather than neural, factors. In this study, we tested relationships between measures of behavioral task performance and BOLD variability during both resting-state and task-driven runs of a Stroop and an animacy judgment task in a large, well-characterized sample of cognitively normal middle-aged to older adults. Resting-state BOLD variability was related to composite measures of global cognition and attentional control, but these relationships were eliminated after correction for age or cardiovascular estimates. In contrast, task-driven BOLD variability was related to attentional control measured both inside and outside the scanner, and importantly, these relationships persisted after correction for age and cardiovascular measures. Overall, these results suggest that BOLD variability is a behaviorally sensitive signal. However, resting-state and task-driven estimates of BOLD variability may differ in the degree to which they are sensitive to age-related, cardiovascular, and neural mechanisms

Antimicrobial resistance to 14 antimicrobials in marine coastal waters around Northern Ireland: Use of the novel Relative Resistance Index as a marker of ecological status

Relatively little work has been published on the incidence of antibiotic resistance (ABR) in the marine microbiological environment, which is of importance to animal (fish, mammals, birds) health, zoonotic transmission, distribution of ABR bacteria with oceanic drift, and ultimately human health. A study was performed to determine the diversity of total ABR (intrinsic and acquired resistance) in marine bacteria in shallow coastal waters surrounding Northern Ireland through the use of a novel Relative Resistance Index (RRI) as a surrogate marker for ecological change, particularly in comparing marine water in commercial versus non-commercial sites. Total antibiotic resistance was observed to varying degrees in all marine water specimens and specific resistance levels were as follows, in order of diminishing antibacterial effectiveness: fluoroquinolones \u3e rifampicin \u3e polymyxin \u3e tetracycline \u3e sulphamethoxazole/trimethoprim \u3e third generation cephalosporin and streptomycin \u3e carbapenem \u3e macrolide \u3e clindamycin \u3e vancomycin \u3e fucidic acid \u3e penicillin. None of the sampling sites contained endogenous bacteria that were resistant to ciprofloxacin, while nearly all (19 of 20 sites; 95%) contained bacteria that were resistant to penicillin. Commercial sites had a higher mean RRI score of 6.57±3.58 than non-commercial sites (RRI = 4.08 ± 2.02), which was statistically significant (p = 0.037), indicating that bacteria isolated from seawater in commercial coastal harbors had a higher frequency of antibiotic resistance than non-commercial sources. This novel RRI marker may be useful in assessing ecological change in marine water environments. In conclusion, this study demonstrated that there can be a high level of total ABR (intrinsic and acquired) in bacterial populations in marine water environments, which are multi- and pan-resistant to up to 11 major classes of antibiotics simultaneously. Ecological studies are urgently needed to help define the fate of ABR marine bacteria in their natural environment and their ability to act as reservoirs and donors of ABR to pathogenic bacteria, many of which transiently inhabit the natural environment

Evaluation of Three Primary Teachers’ Approaches to Teaching Scientific Concepts in Persuasive Ways

The research set out in this paper seeks to develop pedagogical knowledge regarding how persuasive teaching approaches can be developed in primary science classrooms. To achieve this, the paper examines three case studies in which the teachers have been charged to develop and implement teaching strategies designed to persuade their children of the usefulness and validity of target scientific concepts. The analysis probes the teachers’ choice of contexts and patterns of discourse using criteria drawn from the sociocultural literature. Outcomes of the study exemplify how the teachers’ choices of learning contexts fail to emphasise the functionality of the target concepts and as a consequence scant rewards are provided for the children to participate actively in conceptually rich discourse. The final part of the paper explores how the development of what the author calls theme-specific plots, could be used to help teachers to stage teaching and learning performances which emphasise the functionality of specific explanatory models

HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES1 Is Required for Circadian Periodicity through the Promotion of Nucleo-Cytoplasmic mRNA Export in Arabidopsis.

notes: PMCID: PMC3875725This is an open access article that is freely available in ORE or from the publisher's web site. Please cite the published version. © 2013 American Society of Plant Biologists. All rights reserved.Cold acclimation has been shown to be attenuated by the degradation of the INDUCER OF CBF EXPRESSION1 protein by the E3 ubiquitin ligase HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES1 (HOS1). However, recent work has suggested that HOS1 may have a wider range of roles in plants than previously appreciated. Here, we show that hos1 mutants are affected in circadian clock function, exhibiting a long-period phenotype in a wide range of temperature and light environments. We demonstrate that hos1 mutants accumulate polyadenylated mRNA in the nucleus and that the circadian defect in hos1 is shared by multiple mutants with aberrant mRNA export, but not in a mutant attenuated in nucleo-cytoplasmic transport of microRNAs. As revealed by RNA sequencing, hos1 exhibits gross changes to the transcriptome with genes in multiple functional categories being affected. In addition, we show that hos1 and other previously described mutants with altered mRNA export affect cold signaling in a similar manner. Our data support a model in which altered mRNA export is important for the manifestation of hos1 circadian clock defects and suggest that HOS1 may indirectly affect cold signaling through disruption of the circadian clock.Biotechnology and Biological Science Research Counci

A Prospective Study of the Association of Metacognitive Beliefs and Processes with Persistent Emotional Distress After Diagnosis of Cancer

Two hundred and six patients, diagnosed with primary breast or prostate cancer completed self-report questionnaires on two occasions: before treatment (T1) and 12 months later (T2). The questionnaires included: the Hospital Anxiety and Depression Scale; Impact of Events Scale; the Metacognitions Questionnaire-30 (MCQ-30) and the Illness Perceptions Questionnaire-revised. A series of regression analyses indicated that metacognitive beliefs at T1 predicted between 14 and 19 % of the variance in symptoms of anxiety, depression and trauma at T2 after controlling for age and gender. For all three outcomes, the MCQ-30 subscale ‘negative beliefs about worry’ made the largest individual contribution with ‘cognitive confidence’ also contributing in each case. For anxiety, a third metacognitive variable, ‘positive beliefs about worry’ also predicted variance in T2 symptoms. In addition, hierarchical analyses indicated that metacognitive beliefs explained a small but significant amount of variance in T2 anxiety (2 %) and T2 depression (4 %) over and above that explained by demographic variables, T1 symptoms and T1 illness perceptions. The findings suggest that modifying metacognitive beliefs and processes has the potential to alleviate distress associated with cancer

The Workshop Tutorial project book launch during the 2003 UniServe Science Conference

The Workshop Tutorial project has grown in answer to the perceived need to provide students with an opportunity to use and discuss principles of physics and their applications in a learning environment that encourages interaction with peers and supervising staff. In this manner the Workshops compliment the large traditional lectures that students are expected to attend. The style of the questions and activities are chosen to provide a mixture of quantitative and qualitative conceptbased questions and concrete hands-on activities. Reference to research in physics education on student misconceptions has been made in formulating questions (Sharma, Millar and Seth 1999)