Are Minerals Costing More?

This is a working paper in a continuing project "Mineral Scarcity and Economic Change", partially supported at IIASA by the U.S. National Academy of Sciences. In the present paper evidence is given on trends in relative cost to obtain minerals, for selected regions and countries. On this basis the question of increasing economic scarcity of minerals is addressed, and attention is given to the underlying forces that affect mineral cost trends. The data that are used are from an IIASA data base that covers about 50 mineral price series and economic variables on 45 countries. However, in this paper we focus primarily on Western European countries for the period 1950-1979. Since the data effort finished in summer 1980, the second oil price boom is not fully reflected

Adolescent Sleep Behavioral Interventions and Opportunities to Improve Cognitive Functioning: A Call for Action

Sleep is related to cognitive functioning, learning, and brain development in the adolescent population. Recent research indicates a rise in the presence of chronic sleep disorders such as insomnia in adolescents, particularly following the COVID-19 pandemic. Therefore, research on the effectiveness of sleep interventions for adolescents is necessary to guide treatment in adolescents. The authors conducted a systematic review of literature examining research on outcomes of treatment interventions for insomnia on sleep quality and cognitive functioning in adolescents. Results indicate a dearth of research examining effectiveness of treatment in adolescents, particularly in relation to the impact of such treatment on cognitive functioning in adolescents. The following paper provides a brief overview of existing research on treatment of insomnia or related problems including initiating, maintaining and awaking for adolescent populations with a focus on improvement of cognitive functioning within this population. The authors discuss existing barriers to research, emphasize the need to expand sleep research to include cognitive functioning outcomes, and inform best practices for treatment in adolescents following COVID-19. Lastly, the authors propose a call to action encouraging more widespread recognition of the need for research in this area

Spin-Flip Noise in a Multi-Terminal Spin-Valve

We study shot noise and cross correlations in a four terminal spin-valve geometry using a Boltzmann-Langevin approach. The Fano factor (shot noise to current ratio) depends on the magnetic configuration of the leads and the spin-flip processes in the normal metal. In a four-terminal geometry, spin-flip processes are particular prominent in the cross correlations between terminals with opposite magnetization.Comment: 4 pages, 3 figure

Breast Cancer-Derived Microparticles Reduce Cancer Cell Adhesion, an Effect Augmented by Chemotherapy

Tumor cell heterogeneity is primarily dictated by mutational changes, sometimes leading to clones that undergo a metastatic switch. However, little is known about tumor heterogeneity following chemotherapy perturbation. Here we studied the possible involvement of tumor-derived extracellular vesicles, often referred to as tumor-derived microparticles (TMPs), as mediators of the metastatic switch in the tumor microenvironment by hindering cell adhesion properties. Specifically, we show that highly metastatic or chemotherapy-treated breast cancer cells shed an increased number of TMPs compared to their respective controls. We found that these TMPs substantially reduce cell adhesion and disrupt actin filament structure, therefore increasing their biomechanical force pace, further implicating tumor cell dissemination as part of the metastatic cascade. Our results demonstrate that these pro-metastatic effects are mediated in part by CD44 which is highly expressed in TMPs obtained from highly metastatic cells or cells exposed to chemotherapy when compared to cells with low metastatic potential. Consequently, when we inhibited CD44 expression on TMPs by a pharmacological or a genetic approach, increased tumor cell adhesion and re-organized actin filament structure were observed. We also demonstrated that breast cancer patients treated with paclitaxel chemotherapy exhibited increased CD44-expressing TMPs. Overall, our study provides further insights into the role of TMPs in promoting metastasis, an effect which is augmented when tumor cells are exposed to chemotherapy

Insights from Eye Blinks into the Cognitive Processes Involved in Visual Word Recognition

Behavioral differences in speed and accuracy between reading familiar and unfamiliar words are well-established in the empirical literature. However, these standard measures of skill proficiency are limited in their ability to capture the moment-to-moment processing involved in visual word recognition. In the present study, the effect of word familiarity was initially investigated using an eye blink rate among adults and children. The probability of eye blinking was higher for familiar (real) words than for unfamiliar (pseudo)words. This counterintuitive pattern of results suggests that the processing of unfamiliar (pseudo)words is more demanding and perhaps less rewarding than the processing of familiar (real) words, as previously observed in both behavioral and pupillometry data. Our findings suggest that the measurement of eye blinks might shed new light on the cognitive processes involved in visual word recognition and other domains of human cognition

Replication factory activation can be decoupled from the replication timing program by modulating Cdk levels

In the metazoan replication timing program, clusters of replication origins located in different subchromosomal domains fire at different times during S phase. We have used Xenopus laevis egg extracts to drive an accelerated replication timing program in mammalian nuclei. Although replicative stress caused checkpoint-induced slowing of the timing program, inhibition of checkpoint kinases in an unperturbed S phase did not accelerate it. Lowering cyclin-dependent kinase (Cdk) activity slowed both replication rate and progression through the timing program, whereas raising Cdk activity increased them. Surprisingly, modest alteration of Cdk activity changed the amount of DNA synthesized during different stages of the timing program. This was associated with a change in the number of active replication factories, whereas the distribution of origins within active factories remained relatively normal. The ability of Cdks to differentially effect replication initiation, factory activation, and progression through the timing program provides new insights into the way that chromosomal DNA replication is organized during S phase

Statin Efficacy and Safety for Lipid Modification in Apparently Healthy Male Military Aircrew

Introduction: Military aircrew men represent an elite group of relatively young, fit, and healthy people. The effectiveness of statin treatment in reducing low-density lipoprotein cholesterol (LDL-C) according to the current National Cholesterol Education Program (NCEP) guidelines, its safety, and compliance in this group of people has not yet been determined. Methods: We prospectively evaluated 84 military aircrew men (mean age 43 Ϯ 7 yr) with LDL-C above the current NCEP guidelines. The patients were divided into two groups according to their coronary risk factors: Group 1, LDL-C goal Ͻ 160 mg ⅐ dL Ϫ1 ; Group 2, LDL-C goal Ͻ 130 mg ⅐ dL Ϫ1 . All patients received statins in addition to therapeutic lifestyle changes and were followed for a mean of 3 Ϯ 1 yr according to a simple flow chart. Lipoprotein levels, liver function tests, creatinine phosphokinase, and subjective adverse reactions were checked periodically. Results: LDL-C significantly declined by 32% (p Ͻ 0.0001) within the first month of treatment and 99% of subjects achieved their LDL-C goal within 114 Ϯ 35 d from statin therapy initiation. The Framingham estimated 10-yr coronary risk showed a reduction at an average of 12 mo after statin therapy initiation from a baseline value of 6.54% to 3.95% (p ϭ 0.003). No subjects were grounded or disqualified from duty, there were no cardiovascular events during follow-up, and compliance to therapy was high [82/84 (98%)]. Discussion: Statin treatment in this highly select, relatively young group of aircrew men significantly and safely lowered LDL-C cholesterol levels