Introduction to Library Trends 55 (3) Winter 2007: Libraries in Times of War, Revolution and Social Change

published or submitted for publicatio

Haploinsufficiency of the Myc regulator Mtbp extends survival and delays tumor development in aging mice.

Alterations of specific genes can modulate aging. Myc, a transcription factor that regulates the expression of many genes involved in critical cellular functions was shown to have a role in controlling longevity. Decreased expression of Myc inhibited many of the deleterious effects of aging and increased lifespan in mice. Without altering Myc expression, reduced levels of Mtbp, a recently identified regulator of Myc, limit Myc transcriptional activity and proliferation, while increased levels promote Myc-mediated effects. To determine the contribution of Mtbp to the effects of Myc on aging, we studied a large cohort of Mtbp heterozygous mice and littermate matched wild-type controls. Mtbp haploinsufficiency significantly increased longevity and maximal survival in mice. Reduced levels of Mtbp did not alter locomotor activity, litter size, or body size, but Mtbp heterozygous mice did exhibit elevated markers of metabolism, particularly in the liver. Mtbp(+/-) mice also had a significant delay in spontaneous cancer development, which was most prominent in the hematopoietic system, and an altered tumor spectrum compared to Mtbp(+/+) mice. Therefore, the data suggest Mtbp is a regulator of longevity in mice that mimics some, but not all, of the properties of Myc in aging

Conservatism in Laboratory Microsocieties: Unpredictable Payoffs Accentuate Group-Specific Traditions

Theoretical work predicts that individuals should strategically increase their reliance on social learning when individual learning would be costly or risky, or when the payoffs for individually-learned behaviors are uncertain. Using a method known to elicit cumulative cultural evolution in the laboratory, we investigated the degree of within-group similarity, and between-group variation, in design choices made by participants under conditions of varying uncertainty about the likely effectiveness of those designs. Participants were required to build a tower from spaghetti and modeling clay, their goal being to build the tower as high as possible. In one condition, towers were measured immediately on completion, and therefore participants were able to judge the success of their design during building. In the other condition, participants’ towers were measured five minutes after completion, following a deliberate attempt to test the tower’s stability, making it harder for participants to judge whether an innovative solution was liable to result in a good score on the final measurement. Cultural peculiarity (i.e. the extent to which a design could be identified as belonging to a particular chain) was stronger in the delayed measure condition, indicating that participants were placing greater reliance on social learning. Furthermore in this condition there was only very weak evidence of successive improvement in performance over learner generations, whereas in the immediate measure condition there was a clear effect of steadily increasing scores on the goal measurement. Increasing the risk associated with learning for oneself may favor the development of arbitrary traditions

Studying cumulative cultural evolution in the laboratory

Cumulative cultural evolution is the term given to a particular kind of social learning, which allows for the accumulation of modifications over time, involving a ratchet-like effect where successful modifications are maintained until they can be improved upon. There has been great interest in the topic of cumulative cultural evolution from researchers from a wide variety of disciplines, but until recently there were no experimental studies of this phenomenon. Here we describe our motivations for developing experimental methods for studying cumulative cultural evolution, and review results we have obtained using these techniques. The results that we describe have provided insights into understanding the outcomes of cultural processes at the population level. Our experiments show that cumulative cultural evolution can result in adaptive complexity in behaviour, and also can also produce convergence in behaviour. These findings lend support to ideas that some behaviours commonly attributed to natural selection and innate tendencies could in fact be shaped by cultural processes

Curriculum implementation exploratory studies: Final report

Throughout the history of schooling in New Zealand the national curriculum has been revised at fairly regular intervals. Consequently, schools are periodically faced with having to accommodate to new curriculum. In between major changes other specifically-focused changes may arise; for example, the increased recent emphasis upon numeracy and literacy

Media and Youth Development: An Overview of Issues, Theory, and Research

The homes of today’s youth are filled with a variety of media options, ranging from televisions (71%) and video game consoles (50%) in their bedrooms to portable handheld devices (e.g., iPods/mp3 players, 76%) and cell phones (71%) that can accompany youth wherever they go. Of course, youth also have access to centralized media found in homes, such as televisions (99% of homes) and computers with and without Internet access (93% and 84% of homes, respectively). Not surprisingly, youth consume media for about 7.5 hours per day, much of which involves using more than one media at the same time (i.e., multitasking), with adolescents consuming significantly more media than children (Lenhart, 2012; Rideout, Foehr, & Roberts, 2010)

Outcomes, experiences and palliative care in major stroke:a multicentre, mixed-method, longitudinal study

Background: Case fatality after total anterior circulation stroke is high. Our objective was to describe the experiences and needs of patients and caregivers, and to explore whether, and how, palliative care should be integrated into stroke care. Methods: From 3 stroke services in Scotland, we recruited a purposive sample of people with total anterior circulation stroke, and conducted serial, qualitative interviews with them and their informal and professional caregivers at 6 weeks, 6 months and 1 year. Interviews were transcribed for thematic and narrative analysis. The Palliative Care Outcome Scale, EuroQol-5D-5L and Caregiver Strain Index questionnaires were completed after interviews. We also conducted a data linkage study of all patients with anterior circulation stroke admitted to the 3 services over 6 months, which included case fatality, place of death and readmissions. Results: Data linkage (n = 219) showed that 57% of patients with total anterior circulation stroke died within 6 months. The questionnaires recorded that the patients experienced immediate and persistent emotional distress and poor quality of life. We conducted 99 interviews with 34 patients and their informal and professional careers. We identified several major themes. Patients and caregivers faced death or a life not worth living. Those who survived felt grief for a former life. Professionals focused on physical rehabilitation rather than preparation for death or limited recovery. Future planning was challenging. “Palliative care” had connotations of treatment withdrawal and imminent death. Interpretation: Major stroke brings likelihood of death but little preparation. Realistic planning with patients and informal caregivers should be offered, raising the possibility of death or survival with disability. Practising the principles of palliative care is needed, but the term “palliative care” should be avoided or reframed

Association of metabolic syndrome and change in Unified Parkinson\u27s Disease Rating Scale scores.

OBJECTIVE: To explore the association between metabolic syndrome and the Unified Parkinson\u27s Disease Rating Scale (UPDRS) scores and, secondarily, the Symbol Digit Modalities Test (SDMT). METHODS: This is a secondary analysis of data from 1,022 of 1,741 participants of the National Institute of Neurological Disorders and Stroke Exploratory Clinical Trials in Parkinson Disease Long-Term Study 1, a randomized, placebo-controlled trial of creatine. Participants were categorized as having or not having metabolic syndrome on the basis of modified criteria from the National Cholesterol Education Program Adult Treatment Panel III. Those who had the same metabolic syndrome status at consecutive annual visits were included. The change in UPDRS and SDMT scores from randomization to 3 years was compared in participants with and without metabolic syndrome. RESULTS: Participants with metabolic syndrome (n = 396) compared to those without (n = 626) were older (mean [SD] 63.9 [8.1] vs 59.9 [9.4] years; p \u3c 0.0001), were more likely to be male (75.3% vs 57.0%; p \u3c 0.0001), and had a higher mean uric acid level (men 5.7 [1.3] vs 5.3 [1.1] mg/dL, women 4.9 [1.3] vs 3.9 [0.9] mg/dL, p \u3c 0.0001). Participants with metabolic syndrome experienced an additional 0.6- (0.2) unit annual increase in total UPDRS (p = 0.02) and 0.5- (0.2) unit increase in motor UPDRS (p = 0.01) scores compared with participants without metabolic syndrome. There was no difference in the change in SDMT scores. CONCLUSIONS: Persons with Parkinson disease meeting modified criteria for metabolic syndrome experienced a greater increase in total UPDRS scores over time, mainly as a result of increases in motor scores, compared to those who did not. Further studies are needed to confirm this finding. CLINICALTRIALSGOV IDENTIFIER: NCT00449865

Experimental models for testing hypotheses about cumulative cultural evolution

The rapid appearance (over evolutionary time) of the cognitive skills and complex inventions of modern humans has been attributed to “cumulative cultural evolution” (henceforth CCE), the accumulation of knowledge and skills over generations. To date, researchers have only been able to speculate about the reasons for the apparent absence of this phenomenon in nonhumans, and it has not been possible to test hypotheses regarding the mechanisms underlying it. Here we show that it is possible to demonstrate CCE under laboratory conditions, by simulating generational succession through the repeated removal and replacement of human participants within experimental groups. We created “microsocieties” in which participants were instructed to complete simple tasks using everyday materials. In one of our procedures, participants were instructed to build a paper aeroplane which flew as far as possible, and in the other, they were instructed to construct a tower of spaghetti which was as tall as possible. We show that, in both cases, information accumulates within the groups such that later generations produce designs which are more successful than earlier ones. These methods offer researchers a window to understanding CCE, allowing for experimental manipulation and hypothesis testing

Modelling the health impact of food taxes and subsidies with price elasticities: the case for additional scaling of food consumption using the total food expenditure elasticity

Background Food taxes and subsidies are one intervention to address poor diets. Price elasticity (PE) matrices are commonly used to model the change in food purchasing. Usually a PE matrix is generated in one setting then applied to another setting with differing starting consumption and prices of foods. This violates econometric assumptions resulting in likely misestimation of total food consumption. We illustrate rescaling all consumption after applying a PE matrix using a total food expenditure elasticity (TFEe, the expenditure elasticity for all food combined given the policy induced change in the total price of food). We use case studies of NZ$2 per 100g saturated fat (SAFA) tax, NZ$0.4 per 100g sugar tax, and a 20% fruit and vegetable (F&V) subsidy. Methods We estimated changes in food purchasing using a NZ PE matrix applied conventionally, then with TFEe adjustment. Impacts were quantified for total food expenditure and health adjusted life years (HALYs) for the total NZ population alive in 2011 over the rest of their lifetime using a multistate lifetable model. Results Two NZ studies gave TFEes of 0.68 and 0.83, with international estimates ranging from 0.46 to 0.90. Without TFEe adjustment, total food expenditure decreased with the tax policies and increased with the F&V subsidy, implausible directions of shift given economic theory. After TFEe adjustment, HALY gains reduced by a third to a half for the two taxes and reversed from an apparent health loss to a health gain for the F&V subsidy. With TFEe adjustment, HALY gains (in 1000s) were 1,805 (95% uncertainty interval 1,337 to 2,340) for the SAFA tax, 1,671 (1,220 to 2,269) for the sugar tax, and 953 (453 to 1,308) for the F&V subsidy. Conclusions If PE matrices are applied in settings beyond where they were derived, additional scaling is likely required. We suggest that the TFEe is a useful scalar