History of the tether concept and tether missions: a review

This paper introduces history of space tethers, including tether concepts and tether missions, and attempts to provide a source of references for historical understanding of space tethers. Several concepts of space tethers since the original concept has been conceived are listed in the literature, as well as a summary of interesting applications, and a research of space tethers is given. With the aim of implementing scientific experiments in aerospace, several space tether missions which have been delivered for aerospace application are introduced in the literature.</jats:p

Pak2 regulates hematopoietic progenitor cell proliferation, survival and differentiation

p21-Activated kinase 2 (Pak2), a serine/threonine kinase, has been previously shown to be essential for hematopoietic stem cell (HSC) engraftment. However, Pak2 modulation of long-term hematopoiesis and lineage commitment remain unreported. Using a conditional Pak2 knockout mouse model, we found that disruption of Pak2 in HSCs induced profound leukopenia and a mild macrocytic anemia. Although loss of Pak2 in HSCs leads to less efficient short- and long-term competitive hematopoiesis than wild-type cells, it does not affect HSC self-renewal per se. Pak2 disruption decreased the survival and proliferation of multicytokine stimulated immature progenitors. Loss of Pak2 skewed lineage differentiation toward granulocytopoiesis and monocytopoiesis in mice as evidenced by (a) a three- to sixfold increase in the percentage of peripheral blood granulocytes and a significant increase in the percentage of granulocyte-monocyte progenitors in mice transplanted with Pak2-disrupted bone marrow (BM); (b)Pak2-disrupted BM and c-kit(+) cells yielded higher numbers of more mature subsets of granulocyte-monocyte colonies and polymorphonuclear neutrophils, respectively, when cultured in the presence of granulocyte-macrophage colony-stimulating factor. Pak2 disruption resulted, respectively, in decreased and increased gene expression of transcription factors JunB and c-Myc, which may suggest underlying mechanisms by which Pak2 regulates granulocyte-monocyte lineage commitment. Furthermore, Pak2 disruption led to (a) higher percentage of CD4(+) CD8(+) double positive T cells and lower percentages of CD4(+) CD8(-) or CD4(-) CD8(+) single positive T cells in thymus and (b) decreased numbers of mature B cells and increased numbers of Pre-Pro B cells in BM, suggesting defects in lymphopoiesis

Giant power output in lead-free ferroelectrics by shock-induced phase transition

The force-electric effect in ferroelectrics is characterized by the release of bound charge during pressure/shock-induced depolarization. In contrast to other electrical energy storage systems, the charge-storage/release by the force-electric effect of ferroelectrics is determined by polarization switching or polar-nonpolar phase transition. This offers a further set of options for materials design in the realm of energy conversion, especially for the high power density applications. Here, we report that a ferroelectric ceramic, N a 0.5 B i 0.5 Ti O 3 (NBT), can generate a high power output ( 3.04 × 10 8 W / kg ) under shock compression, which is one of the highest values achieved by the force-electric effect. The in situ synchrotron x-ray diffraction studies reveal that this power output mainly arises from a polar-nonpolar phase transition (rhombohedral-orthorhombic). First-principles calculations show that this is a first-order phase transition that undergoes two-step structure changes. These results extend the application of the force-electric effect and are a key step in understanding the phase transition behaviors of NBT under high pressure

Distributed continuous-time algorithms for nonsmooth extended monotropic optimization problems

This paper studies distributed algorithms for the nonsmooth extended monotropic optimization problem, which is a general convex optimization problem with a certain separable structure. The considered nonsmooth objective function is the sum of local objective functions assigned to agents in a multiagent network, with local set constraints and affine equality constraints. Each agent only knows its local objective function, local set constraint, and the information exchanged between neighbors. To solve the constrained convex optimization problem, we propose two novel distributed continuous-time subgradient-based algorithms, with projected output feedback and derivative feedback, respectively. Moreover, we prove the convergence of proposed algorithms to the optimal solutions under some mild conditions and analyze convergence rates, with the help of the techniques of variational inequalities, decomposition methods, and differential inclusions. Finally, we give an example to illustrate the efficacy of the proposed algorithms

Addressing unmeasured confounding in nonexperimental psychological research: A guide to computing and interpreting E-values

Randomized experiments remain the gold standard for establishing causality, yet ethical and practical constraints in certain fields often require researchers to rely on observational data. Although psychologists recognize that correlations do not imply causality, the conventional cautionary statements regarding correlation typically found at the end of articles have not sufficiently advanced psychological science, particularly in subfields such as developmental and personality psychology that predominantly rely on observational data. Sensitivity analyses commonly used in biostatistics and epidemiology offer powerful tools to address unmeasured confounding in observational data analysis. This tutorial explores the frequently overlooked but critical issue of unmeasured confounding in psychological research and introduces psychologists to the E-value, a novel and straightforward method for assessing the robustness of treatment outcome associations to unmeasured confounding. We demonstrate the application of E-value in common psychological research scenarios using R. The strengths and limitations of E-value are discussed, along with recommended best practices for its implementation in psychological research. By more explicitly discussing unmeasured confounding and incorporating sensitivity analysis techniques like the E-value into their analytical toolkits, psychologists can more accurately assess and transparently report research findings, particularly in subfields that primarily rely on observational data

Psychometric testing of the training needs for advance care planning scale for clinicians and nurses

Abstract Background Studies have shown that Chinese Clinicians and nurses have positive attitudes toward ACP, but no local tools exist to assess their need for ACP knowledge and skills training. resulting in their inability to initiate ACP conversations as well as poor end-of-life care for patients. Therefore, this study aims to assess the needs of Chinese Clinicians and nurses for ACP knowledge and skills training and assess the validity and reliability of a questionnaire on the Training Needs for Advance Care Planning (TNACP) scale. Methods From October to November 2021, 170 clinicians and nurses were pre-surveyed using a preliminary draft of the questionnaire. The responses were screened using item analysis, Cronbach’s alpha coefficient, and the intraclass correlation coefficient (ICC) to describe the internal consistency and stability of the questionnaire. The Content validity index (CVI), Exploratory factor analysis (EFA) and Confirmatory factor analysis (CFA) were used to test the validity of the questionnaire. Results After independent samples t-test analysis, Except for the entry “A2”, the critical ratio between the two groups of the remaining 23 items was statistically significant (p  0.40). The results of confirmatory factor analysis showed that the Training Needs for Advance Care Planning (TNACP) scale model fit well(X2/df = 2.504, RMSEA = 0.092, GFI = 0.809, AGFI = 0.745, CFI = 0.931, IFI = 0.932, TLI = 0.916); the Cronbach’s α = 0.888 for the total questionnaire, and the three dimensions of Cronbach’s α were 0.729 to 0.959; and the ICC for the overall scores between the test-retest evaluations was 0.884 (p < 0.001). Conclusions The TNACP scale has good reliability and validity and can be used to assess Chinese Clinicians and nurses’ training needs for implementing ACP

Pak2 regulates hematopoietic progenitor cell proliferation, survival and differentiation

p21-Activated kinase 2 (Pak2), a serine/threonine kinase, has been previously shown to be essential for hematopoietic stem cell (HSC) engraftment. However, Pak2 modulation of long-term hematopoiesis and lineage commitment remain unreported. Using a conditional Pak2 knockout mouse model, we found that disruption of Pak2 in HSCs induced profound leukopenia and a mild macrocytic anemia. Although loss of Pak2 in HSCs leads to less efficient short- and long-term competitive hematopoiesis than wild-type cells, it does not affect HSC self-renewal per se. Pak2 disruption decreased the survival and proliferation of multicytokine stimulated immature progenitors. Loss of Pak2 skewed lineage differentiation toward granulocytopoiesis and monocytopoiesis in mice as evidenced by (a) a three- to sixfold increase in the percentage of peripheral blood granulocytes and a significant increase in the percentage of granulocyte-monocyte progenitors in mice transplanted with Pak2-disrupted bone marrow (BM); (b)Pak2-disrupted BM and c-kit(+) cells yielded higher numbers of more mature subsets of granulocyte-monocyte colonies and polymorphonuclear neutrophils, respectively, when cultured in the presence of granulocyte-macrophage colony-stimulating factor. Pak2 disruption resulted, respectively, in decreased and increased gene expression of transcription factors JunB and c-Myc, which may suggest underlying mechanisms by which Pak2 regulates granulocyte-monocyte lineage commitment. Furthermore, Pak2 disruption led to (a) higher percentage of CD4(+) CD8(+) double positive T cells and lower percentages of CD4(+) CD8(-) or CD4(-) CD8(+) single positive T cells in thymus and (b) decreased numbers of mature B cells and increased numbers of Pre-Pro B cells in BM, suggesting defects in lymphopoiesis