Cusp catastrophe models for cognitive workload and fatigue: a comparison of seven task types.

The study introduces a nonlinear paradigm that addresses several unresolved problems concerning cognitive workload and fatigue: (a) how to separate the effects of workload versus fatigue, (b) whether the upper boundaries of cognitive channel capacity are fixed or variable, and how multitasking produces a bottleneck phenomenon, (c) that prolonged time on task can produce performance decrements but also produce improvements in task performance associated with practice and automaticity, and that (d) task switching can alleviate fatigue but could be mentally costly. This study describes two cusp catastrophe models that have become useful for separating the workload and fatigue performance phenomena and explores the role of task switching and multitasking in both performance phenomena. In the experiment, 105 undergraduates completed seven computer-based tasks seven times under one of four experimental conditions: tasks fully alternated, tasks aggregated with the multitask module performed first, aggregated with the multitask module performed last, and where the participants chose the task order themselves. Results supported both the cusp models such that fatigue effects were stronger for tasks with higher memory or attentional demand, and were often counteracted by practice effects; spelling ability acted as a compensation variable in most cases, and the intervening amount of work done acted as the bifurcation variable. For cognitive workload, catastrophic shifts in performance were noted between the single tasks and the multitask, with relative difficulty of the single task acting as the load (asymmetry) variable and the flexible task ordering condition as the bifurcation variable.

The minimum entropy principle and task performance.

According to the minimum entropy principle, efficient cognitive performance is produced with a neurocognitive strategy that involves a minimum of degrees of freedom. Although high performance is often regarded as consistent performance as well, some variability in performance still remains which allows the person to adapt to changing goal conditions or fatigue. The present study investigated the connection between performance, entropy in performance, and four task-switching strategies. Fifty-one undergraduates performed 7 different computer-based cognitive tasks producing sets of 49 responses under instructional conditions requiring task quotas or no quotas. The temporal patterns of performance were analyzed using orbital decomposition to extract pattern types and lengths, which were then compared with regard to Shannon entropy, topological entropy, and overall performance. Task switching strategies from a previous study were available for the same participants as well. Results indicated that both topological entropy and Shannon entropy were negatively correlated with performance. Some task-switching strategies produced lower entropy in performance than others. Stepwise regression showed that the top three predictors of performance were Shannon entropy and arithmetic and spatial abilities. Additional implications for the prediction of work performance with cognitive ability measurements and the applicability of the minimum entropy principle to multidimensional performance criteria and team work are discussed.

HIV Viral Load Scale-up Among Children and Adolescents: Trends in Viral Load Suppression, Sample Type and Processing in 7 PEPFAR Countries, 2015-2018.

HIV-positive children and adolescents face gaps in viral load (VL) testing. To understand trends in pediatric/adolescent VL testing, 7 countries collected data from Laboratory Information Management Systems. Results showed increasing proportion of VL tests done through dried blood spot (DBS) and decreased sample rejection rates for DBS compared with plasma, supporting use of DBS VL when skilled phlebotomy is unavailable.

New paradigm for task switching strategies while performing multiple tasks: entropy and symbolic dynamics analysis of voluntary patterns.

It has become well established in laboratory experiments that switching tasks, perhaps due to interruptions at work, incur costs in response time to complete the next task. Conditions are also known that exaggerate or lessen the switching costs. Although switching costs can contribute to fatigue, task switching can also be an adaptive response to fatigue. The present study introduces a new research paradigm for studying the emergence of voluntary task switching regimes, self-organizing processes therein, and the possibly conflicting roles of switching costs and minimum entropy. Fifty-four undergraduates performed 7 different computer-based cognitive tasks producing sets of 49 responses under instructional conditions requiring task quotas or no quotas. The sequences of task choices were analyzed using orbital decomposition to extract pattern types and lengths, which were then classified and compared with regard to Shannon entropy, topological entropy, number of task switches involved, and overall performance. Results indicated that similar but different patterns were generated under the two instructional conditions, and better performance was associated with lower topological entropy. Both entropy metrics were associated with the amount of voluntary task switching. Future research should explore conditions affecting the trade-off between switching costs and entropy, levels of automaticity between task elements, and the role of voluntary switching regimes on fatigue.

Resilience Training Programs in Organizational Contexts: A Scoping Review.

The importance of resilience for employees' well-being and performance at work has grown steadily in recent years. This development has become even more pronounced through the recent COVID-19 pandemic and its consequences, including major changes in occupational settings. Although there is increasing interest in resilience in general and a growing number of publications focusing on the development of resilience in particular, many questions remain about resilience training, especially in organizational contexts. The purpose of this scoping review is to uncover what is known about resilience training in organizational contexts. A systematic search of four databases for articles published through 2021 was conducted. A total of 48 studies focusing on resilience training programs in organizational contexts were included in this review. The review provides relevant insights into resilience training programs by focusing on program characteristics, target group, study design, and outcomes. Based on the results, the main aspects that concern the development of resilience training programs for organizational settings and requirements for the study design for empirical investigation were summarized. The results of the review highlight possible directions for future research and offer useful insights for resilience-enhancing training programs in organizations.

A Primary Care Provider's Guide to Depression After Spinal Cord Injury: Is It Normal? Do We Treat It?

Although most people with spinal cord injury (SCI) are emotionally resilient, as a group they are at increased risk of major depressive disorder. Depression tends to be undertreated in people with SCI, perhaps because depression is mistakenly viewed as an expected reaction to severe disability or is confused with grief. Depression and grief are distinguishable, and the Patient Health Questionnaire-9 is a reliable and valid screen for major depression in this population. Major depression can be treated with antidepressants, especially venlafaxine XR, and with psychotherapy, especially cognitive behavioral therapy, focused on helping the person resume activities that were previously enjoyable or meaningful. Structured exercise also may help relieve depressed mood.

Cyclin D1 overexpression in proliferation centres of small lymphocytic lymphoma/chronic lymphocytic leukaemia.

The recent publication reviewing the updated WHO classification commented on the presence of cyclin D1-positive cells in the proliferation centres (PC) of small lymphocytic lymphoma/chronic lymphocytic leukaemia (SLL/CLL). The figure quoted was 30%, which appeared higher than our experience. To assess cyclin D1 expression in PC of SLL/CLL cases, we performed a review of SLL/CLL cases diagnosed at the Royal Marsden Hospital between 1996 and 2009. Of 105 SLL/CLL cases, 16.2% showed expression of cyclin D1 in PC with none carrying the translocation t(11;14)(q13;q32). Our study and a review of the published literature suggest that this phenomenon occurs with a significantly lower prevalence than that described in the recent review of the updated WHO classification. We confirm that cyclin D1 expression is confined to PC with the typical small lymphocytes being negative. This finding is apparently unrelated to the translocation involving CCND1 and IGH genes.

Communicating with Patients' Families and Physicians About Prognosis and Goals of Care.

BACKGROUND: Integrating palliative care into intensive care requires active involvement of bedside nurses in discussions of patients' prognosis and goals of care. OBJECTIVE: To improve critical care nurses' skills and confidence to engage in discussions with patients' families and physicians about prognosis and goals of care by using a focused educational intervention. METHODS: An 8-hour-long workshop was developed for critical care nurses. Key roles and skills of nurses in communication about prognosis and goals of care were defined. Participants practiced skills during facilitated role-plays. A reflection session addressed burnout, distress, and self-care. Participants completed surveys before, immediately after, and 3 months after their workshop, rating their confidence and skill in performing key tasks. Use of a participant focus group and open-response items in the surveys further elucidated the impact of the workshop. RESULTS: Between March 2011 and April 2013, a total of 82 critical care nurses completed a workshop. Compared with before the workshop, after the workshop, nurses reported greater skill and confidence for 14 survey items (P < .001), including assessing families' understanding of prognosis and goals of care, addressing families' emotional needs, and contributing to family meetings. Increases were sustained 3 months after the workshop. CONCLUSION: Defining roles and providing opportunities for skills practice and reflection can enhance nurses' confidence to engage in discussions about prognosis and goals of care.

Cusp catastrophe models for cognitive workload and fatigue in a verbally cued pictorial memory task.

OBJECTIVE: The aim of this study was to evaluate two cusp catastrophe models for cognitive workload and fatigue. They share similar cubic polynomial structures but derive from different underlying processes and contain variables that contribute to flexibility with respect to load and the ability to compensate for fatigue. BACKGROUND: Cognitive workload and fatigue both have a negative impact on performance and have been difficult to separate. Extended time on task can produce fatigue, but it can also produce a positive effect from learning or automaticity. METHOD: In this two-part experiment, 129 undergraduates performed tasks involving spelling, arithmetic, memory, and visual search. RESULTS: The fatigue cusp for the central memory task was supported with the quantity of work performed and performance on an episodic memory task acting as the control parameters. There was a strong linear effect, however. The load manipulations for the central task were competition with another participant for rewards, incentive conditions, and time pressure. Results supported the workload cusp in which trait anxiety and the incentive manipulation acted as the control parameters. CONCLUSION: The cusps are generally better than linear models for analyzing workload and fatigue phenomena; practice effects can override fatigue. Future research should investigate multitasking and task sequencing issues, physical-cognitive task combinations, and a broader range of variables that contribute to flexibility with respect to load or compensate for fatigue. APPLICATIONS: The new experimental medium and analytic strategy can be generalized to virtually any real-world cognitively demanding tasks. The particular results are generalizable to tasks involving visual search.

Exenatide twice daily versus premixed insulin aspart 70/30 in metformin-treated patients with type 2 diabetes: a randomized 26-week study on glycemic control and hypoglycemia.

OBJECTIVE: Hypoglycemia causes recurrent morbidity in patients with type 2 diabetes. This study evaluated if exenatide twice daily (BID) was noninferior to premixed insulin aspart 70/30 BID (PIA) for glycemic control and associated with less hypoglycemia. RESEARCH DESIGN AND METHODS: In this open-label study, metformin-treated adults with type 2 diabetes were randomized to 26-week treatment with exenatide BID (4 weeks 5 µg, then 10 µg) or PIA. RESULTS: Exenatide BID (n = 181) was noninferior to PIA (n = 173) for A1C control (least squares [LS] mean change -1.0 vs. -1.14%; difference [95% CI] 0.14 [-0.003 to 0.291]) and associated with a lower risk for hypoglycemia (8.0 vs. 20.5%, P < 0.05). LS mean weight decreased by 4.1 kg and increased by 1.0 kg with PIA (P < 0.001). A total of 39.2 vs. 20.8% of patients reached the composite end point of A1C <7.0%, no weight gain, and no hypoglycemia (P < 0.001; post hoc analysis). CONCLUSIONS: In metformin-treated patients, exenatide BID was noninferior to PIA for glycemic control but superior for hypoglycemia and weight control.