A commentary of the paper ‘Humanin variant P3S is associated with longevity in APOE4 carriers and resists APOE4‐induced brain pathology’ that appeared recently in Aging Cell. The possible association ...of a mitochondrial haplogroup with a disease is frequently discussed. The Humanin peptide encoded by the mtDNA has been shown to play an important regulatory role in cell metabolism. There are variants of Humanin caused by different mutations and it is known that the potent form of Humanin, termed S14G, is found naturally in the people of haplogroup U6a7a1a because they have the mutation m.A2672G; however it has not been shown that having this mutation is indeed beneficial. In their paper, the authors suggest that the mitochondrial DNA mutation, m.C2639T, may be beneficial in people who are in haplogroup N1b and also carry APOE4. The mutation changes the common form of Humanin to Humanin P3S. In the study, the researchers looked at a group of Ashkenazi women who were over the age of 95, and found that a higher proportion of them carried APOE4, suggesting that Humanin P3S protected them against the adverse effects of APOE4. A study in a mouse model supported this finding by showing treatment with Humanin P3S reduced APOE4‐induced brain pathology. In the world population, there are about 500,000 Ashkenazi in haplogroup N1b, predominantly in the subgroup N1b1b1; and there are about 9.5 million non‐Ashkenazi people with the mutation m.C2639T and are therefore also in haplogroup N1b and have Humanin P3S. However, the researchers have yet to show Humanin P3S is of benefit in non‐Ashkenazi people. This paper raises the possibility of a therapeutic use of Humanin P3S in the treatment of Alzheimer's disease.
A commentary on the recent paper which associated the Humanin variant P3S with longevity in aged Ashkenazi women who carried APOE4. There are about 10 million people in the world who have the Humanin variant P3S, of which only about 500,000 are Ashkenazi. So does everyone with Humanin variant P3S have a lowered risk of developing Alzheimer's disease.
There is an ongoing drive to replace the most common transparent conductor, indium tin oxide (ITO), with a material that gives comparable performance, but can be coated from solution at speeds orders ...of magnitude faster than the sputtering processes used to deposit ITO. Metal nanowires are currently the only alternative to ITO that meets these requirements. This Progress Report summarizes recent advances toward understanding the relationship between the structure of metal nanowires, the electrical and optical properties of metal nanowires, and the properties of a network of metal nanowires. Using the structure–property relationship of metal nanowire networks as a roadmap, this Progress Report describes different synthetic strategies to produce metal nanowires with the desired properties. Practical aspects of processing metal nanowires into high‐performance transparent conducting films are discussed, as well as the use of nanowire films in a variety of applications.
Metal nanowires are the first alternative to indium tin oxide (ITO) that can be coated from solution and achieve optoelectronic performance that exceeds that of ITO. This Progress Report gives a timely overview of how to synthesize and process nanowires to create films with a high transmittance and low sheet resistance, and how to use these films to make touch screens, organic light‐emitting diodes (OLEDs), and solar cells.
Metal nanowire (NW) networks have the highest performance of any solution-coatable alternative to ITO, but there is as yet no published process for producing NW films with optoelectronic performance ...that exceeds that of ITO. Here, we demonstrate a process for the synthesis and purification of Ag NWs that, when coated from an ink to create a transparent conducting film, exhibit properties that exceed that of ITO. The diameter, and thus optoelectronic performance, of Ag NWs produced by a polyol synthesis can be controlled by adjusting the concentration of bromide. Ag NWs with diameters of 20 nm and aspect ratios up to 2000 were obtained by adding 2.2 mM NaBr to a Ag NW synthesis, but these NWs were contaminated by nanoparticles. Selective precipitation was used to purify the NWs, resulting in a transmittance improvement as large as 4%. At 130.0 Ω sq–1, the transmittance of the purified Ag NW film was 99.1%.
Extra-pair paternity (EPP) is extremely variable among species of birds,
both in its frequency and in the behavioral events that produce it. A flood of
field studies and comparative analyses has ...stimulated an array of novel ideas,
but the results are limited in several ways. The prevailing view is that EPP is
largely the product of a female strategy. We evaluate what is known about the
behavioral events leading to EPP and find the justification for this view to be
weak. Conflict theory (derived from selection theory) predicts that adaptations
in all the players involved will influence the outcome of mating interactions,
producing complex and often highly variable patterns of behavior and levels of
EPP. Data support some of these predictions, but alternative hypotheses abound.
Tests of predictions from conflict theory will require better information on
how males and females encounter one another, behave once they have met, and
influence fertilization once insemination has occurred.
The relatively high temperatures (>200 °C) required to sinter silver nanoparticle inks have limited the development of printed electronic devices on low-cost, heat-sensitive paper and plastic ...substrates. This article explores the change in morphology and resistivity that occurs upon heating thick films of silver nanowires (of two different lengths; Ag NWs), nanoparticles (Ag NPs), and microflakes (Ag MFs) at temperatures between 70 and 400 °C. After heating at 70 °C, films of long Ag NWs exhibited a resistivity of 1.8 × 10–5 Ω cm, 4000 times more conductive than films made from Ag NPs. This result indicates the resistivity of thick films of silver nanostructures is dominated by the contact resistance between particles before sintering. After sintering at 300 °C, the resistivity of short Ag NWs, long Ag NWs, and Ag NPs converge to a value of (2–3) × 10–5 Ω cm, while films of Ag MFs remain ∼10× less conductive (4.06 × 10–4 Ω cm). Thus, films of long Ag NW films heated at 70 °C are more conductive than Ag NP films sintered at 300 °C. Adding 10 wt % nanowires to a film of nanoparticles results in a 400-fold improvement in resistivity.
Transparent conducting films of solution-synthesized copper nanowires are an attractive alternative to indium tin oxide due to the relative abundance of Cu and the low cost of solution-phase nanowire ...coating processes. However, there has to date been no way to protect Cu nanowires with a solution-phase process that does not adversely affect the optoelectric performance of Cu nanowire films. This article reports that the electrodeposition of zinc, tin, or indium shells onto Cu nanowires, followed by oxidation of these shells, enables the protection of Cu nanowire films against oxidation without decreasing film performance.
•This review investigates frameworks of thinking skills and educational objectives situated in empirical research.•This review develops an integrated framework of learning outcomes based on extant ...thinking skills research.•The integrated framework identifies memory and comprehension as foundational processes necessary for the application of CT.•The framework integrates reflective judgement and self-regulatory functions of metacognition with past CT conceptualisations.
Critical thinking is a metacognitive process that, through purposeful, reflective judgement, increases the chances of producing a logical conclusion to an argument or solution to a problem. Instruction in critical thinking is becoming exceedingly important because it allows individuals to gain a more complex understanding of information they encounter and promotes good decision-making and problem-solving in real-world applications (Butler et al., 2012; Halpern, 2003; Ku, 2009). Due to what can be considered an exponential increase in the creation of new information every year (Darling-Hammond, 2008; Jukes & McCain, 2002), critical thinking skills are needed more than ever in order to aid individuals in becoming more adaptable, flexible and better able to cope with this rapidly evolving information. This review investigates existing theoretical frameworks of thinking skills and educational objectives, as well as cognitive models situated in empirical research; and aims to develop an integrated framework of learning outcomes based on the integration of these extant frameworks with recent conceptualisations of critical thinking.
This article describes a room-temperature solution-phase process for the synthesis of copper–silver (Cu–Ag), copper–gold (Cu–Au), and copper–platinum (Cu–Pt) core–shell nanowires (NWs) in which ...ascorbic acid removes the passivating copper oxide coating from the Cu NWs and reduces noble metal ions onto the Cu NWs while preventing galvanic replacement. Cu–Ag NWs are conductive as printed, and the resulting NW films exhibit optoelectronic properties equivalent to films of Ag NWs with a similar aspect ratio. Unlike Cu NWs, Cu–Ag NWs were resistant to oxidation in dry air at 160 °C and under humid conditions (85% RH) at 85 °C for 24 h.
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