High-temperature Complementary Metal Oxide Semiconductors (CMOS)

The results of an investigation into the possibility of using complementary metal oxide semiconductor (CMOS) technology for high temperature electronics are presented. A CMOS test chip was specifically developed as the test bed. This test chip incorporates CMOS transistors that have no gate protection diodes; these diodes are the major cause of leakage in commercial devices

Getting Up to Speed: Acceleration Strategies in the Florida Scrub Lizard, \u3cem\u3eSceloporus woodi\u3c/em\u3e

Small animals typically rely on quick bursts and intermittent pauses when moving in the wild. Hence, the study of acceleration capacity is important for understanding the ecology and evolution of locomotor performance. In this study, we investigate intraspecific variation in the acceleration capacity of a small lizard (Sceloporus woodi). To quantify animal acceleration performance, the momentum‐impulse theorem is applied to data collected from high‐speed video recordings of individuals accelerating from a standstill and over a subsequent distance of 0.4 m. Unlike earlier studies, the momentum‐impulse approach allows one to directly and precisely quantify the per step contribution to acceleration capacity. Like other small vertebrates, we show that S. woodi is capable of accelerating to near maximum speeds (∼2 m s−1) within ∼0.4 m and needs only a few steps (at least five) to achieve maximum speed. However, considerable intraspecific variation in acceleration capacity exists; individuals take different numbers of steps (two to five steps) over the first 0.4 m, and only some individuals (10 of 19) reach their maximum speed over the first 0.4 m. Only acceleration performance in steps 1 and 2 is predictive of running speed at 0.4 m; accelerations in steps 3, 4, and 5 are not related to individual differences in speed. Individual variation in acceleration strategy is considerable, with individuals using one of three strategies to reach maximum speed. Muscle mass‐specific power during acceleration approaches the maximum power output measured for lizard hindlimb musculature (∼900 W kg−1), suggesting that S. woodi accelerations approach the limit of their musculoskeletal system. This study highlights the utility of the momentum‐impulse approach to study acceleration performance and the importance of elucidating the per step contribution to acceleration capacity

Hormonal Signal Amplification Mediates Environmental Conditions during Development and Controls an Irreversible Commitment to Adulthood

Many animals can choose between different developmental fates to maximize fitness. Despite the complexity of environmental cues and life history, different developmental fates are executed in a robust fashion. The nematode Caenorhabditis elegans serves as a powerful model to examine this phenomenon because it can adopt one of two developmental fates (adulthood or diapause) depending on environmental conditions. The steroid hormone dafachronic acid (DA) directs development to adulthood by regulating the transcriptional activity of the nuclear hormone receptor DAF-12. The known role of DA suggests that it may be the molecular mediator of environmental condition effects on the developmental fate decision, although the mechanism is yet unknown. We used a combination of physiological and molecular biology techniques to demonstrate that commitment to reproductive adult development occurs when DA levels, produced in the neuroendocrine XXX cells, exceed a threshold. Furthermore, imaging and cell ablation experiments demonstrate that the XXX cells act as a source of DA, which, upon commitment to adult development, is amplified and propagated in the epidermis in a DAF-12 dependent manner. This positive feedback loop increases DA levels and drives adult programs in the gonad and epidermis, thus conferring the irreversibility of the decision. We show that the positive feedback loop canalizes development by ensuring that sufficient amounts of DA are dispersed throughout the body and serves as a robust fate-locking mechanism to enforce an organism-wide binary decision, despite noisy and complex environmental cues. These mechanisms are not only relevant to C. elegans but may be extended to other hormonal-based decision-making mechanisms in insects and mammals

Self-assembled monolayer of designed and synthesized triazinedithiolsilane molecule as interfacial adhesion enhancer for integrated circuit

Self-assembled monolayer (SAM) with tunable surface chemistry and smooth surface provides an approach to adhesion improvement and suppressing deleterious chemical interactions. Here, we demonstrate the SAM comprising of designed and synthesized 6-(3-triethoxysilylpropyl)amino-1,3,5-triazine-2,4-dithiol molecule, which can enhance interfacial adhesion to inhibit copper diffusion used in device metallization. The formation of the triazinedithiolsilane SAM is confirmed by X-ray photoelectron spectroscopy. The adhesion strength between SAM-coated substrate and electroless deposition copper film was up to 13.8 MPa. The design strategy of triazinedithiolsilane molecule is expected to open up the possibilities for replacing traditional organosilane to be applied in microelectronic industry

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum