Resonances and Lander Modes Observed by InSight on Mars (1–9 Hz)

ABSTRACT The National Aeronautics and Space Administration’s (NASAs) Interior exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) lander successfully touched down on Mars in November 2018, and, for the first time, a seismometer was deployed on the surface of the planet. The seismic recordings reveal diurnal and seasonal changes of the broadband noise level that are consistent with variations of the local atmospheric conditions. The seismic data include a variety of spectral peaks, which are interpreted as wind-excited, mechanical resonances of the lander, resonances of the subsurface, or artifacts produced in the measurement system. Understanding the origin of these signals is critical for the detection and characterization of marsquakes as well as for studies investigating the ambient noise. We identify the major spectral peaks up to 9 Hz, corresponding to the frequency range the most relevant to observed marsquakes. We track the variations in frequency, amplitude, and polarization of these peaks over the duration of the mission so far. The majority of these peaks can readily be classified as measurement artifacts or lander resonances (lander modes), of which the latter have a temperature-dependent peak frequency and a wind-sensitive amplitude. Of particular interest is a prominent resonance at 2.4 Hz, which is used to discriminate between seismic events and local noise and is possibly produced by a subsurface structure. In contrast to the lander modes, the 2.4 Hz resonance has distinctly different features: (1) a broad and stable spectral shape, slightly shifted on each component; (2) predominantly vertical energy; (3) temperature-independent peak frequency; (4) comparatively weak amplification by local winds, though there is a slow change in the diurnal and seasonal amplitude; and (5) excitation during all seismic events that excite this frequency band. Based on these observations, we suggest that the 2.4 Hz resonance is the only mode below 9 Hz that could be related to a local ground structure.

Why we dehumanize illegal immigrants: A US mixed-methods study

Dehumanization is a topic of significant interest for academia and society at large. Empirical studies often have people rate the evolved nature of outgroups and prior work suggests immigrants are common victims of less-than-human treatment. Despite existing work that suggests who dehumanizes particular outgroups and who is often dehumanized, the extant literature knows less about why people dehumanize outgroups such as immigrants. The current work takes up this opportunity by examining why people dehumanize immigrants said to be illegal and how measurement format affects dehumanization ratings. Participants (N = 672) dehumanized such immigrants more if their ratings were made on a slider versus clicking images of hominids, an effect most pronounced for Republicans. Dehumanization was negatively associated with warmth toward illegal immigrants and the perceived unhappiness felt by illegal immigrants from U.S. immigration policies. Finally, most dehumanization is not entirely blatant but instead, captured by virtuous violence and affect as well, suggesting the many ways that dehumanization can manifest as predicted by theory. This work offers a mechanistic account for why people dehumanize immigrants and addresses how survey measurement artifacts (e.g., clicking on images of hominids vs. using a slider) affect dehumanization rates. We discuss how these data extend dehumanization theory and inform empirical research.

Mesophyll conductance response to short-term changes in pCO2 is related to leaf anatomy and biochemistry in diverse C4 grasses

Mesophyll CO2 conductance (gm) in C3 species responds to short-term (minutes) changes in environment potentially due to changes in some leaf anatomical and biochemical properties and due to measurement artifacts. Compared to C3 species, there is less information about gm responses to short-term changes in environmental conditions like pCO2 across diverse C4 species and the potential determinants of these responses. Using 16 diverse C4-grasses we investigated the response of gm to short-term changes in pCO2 and how this response related to the leaf anatomical and biochemical traits. For all the measured C4-grasses gm increased as CO2 decreased; however, the percent change in gm varied (+13% to +250%) and significantly related to percent changes in leaf transpiration efficiency (TEi). The percent increase in gm was highest in grasses with thinner mesophyll cell walls and greater leaf nitrogen, activities of phosphoenolpyruvate carboxylase (PEPC), Rubisco, and carbonic anhydrase, and a higher affinity of PEPC for bicarbonate substrate. Our study demonstrates that CO2 response of gm varies greatly across diverse C4-grasses and identifies the key leaf anatomical and biochemical traits related to this variation. These findings have implications for improving C4 photosynthetic models, and in attempts to improve TEi through manipulation of gm.

Dyadic Invariance of the Positive Sexuality Scale in Chilean Heterosexual Couples

Gender differences in sexuality-related dimensions have long been investigated in close relationship research. An important assumption when comparing values across gender in dyadic research is that both partners conceptualize the construct under investigation in the same way. Thus, issues of measurement invariance should be considered when working with dyadic data. The aim of the present study was to test the dyadic invariance of the Positive Sexuality Scale (PSS) to assess an individual’s sense of happiness and fulfillment with his/her sexual expression. The PSS was completed by 166 Chilean heterosexual couples, and measurement invariance was tested using confirmatory factor analysis within a dyadic framework. Configural, metric, scalar, and partial strict measurement invariance were supported for the PSS original one-factor model. No between-partner difference was found in the PSS latent factor mean. The functioning of the PSS and the meaning attributed to positive sexuality were the same for both partners. Hence, variations in the PSS levels between both partners in heterosexual couples can be interpreted as true mean differences rather than measurement artifacts.

Determination of the Raman polarizability tensor in the optically anisotropic crystal potassium dihydrogen phosphate and its deuterated analog

The Raman tensor of the dominant A1 modes of the nonlinear optical crystalline material potassium dihydrogen phosphate and its 70% deuterated analog have been ascertained. Challenges in determining the A1 mode tensor element values based on previous reports have been resolved using a specially designed experimental setup that makes use of spherical crystal samples. This novel experimental design enabled the determination of measurement artifacts, including polarization rotation of the pump and/or scattered light propagating through the sample and the contribution of additional overlapping phonon modes, which have hindered previous efforts. Results confirmed that the polarization tensor is diagonal, and matrix elements were determined with high accuracy.

Plasma Treatment of Polypropylene-Based Wood–Plastic Composites (WPC): Influences of Working Gas

In this study, a polypropylene (PP)-based wood–plastic composite with maleic anhydride-grafted polypropylene (MAPP) as a coupling agent and a wood content of 60% was extruded and specimens were injection molded. The samples were plasma treated utilizing a dielectric barrier discharge (DBD) setup with three different working gases: Ar/O2 (90%/10%), Ar/N2 (90%/10%), and synthetic air. This process aims to improve the coating and gluing properties of the otherwise challenging apolar surface of PP based wood–plastic composites (WPC). Chemical analysis with X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) showed the formation of oxygen-based functional groups on the surface, independently from the working gas used for the treatment. Laser scanning microscopy (LSM) examined the surface roughness and revealed that the two argon-containing working gases roughened the surface more than synthetic air. However, the contact angle for water was reduced significantly after treatment, revealing measurement artifacts for water and diiodomethane due to the severe changes in surface morphology. The adhesion of acrylic dispersion coating was significantly increased, resulting in a pull-off strength of approximately 4 N/mm2, and cross-cut tests assigned the best adhesion class (0), on a scale from 0 to 5, after plasma treatment with any working gas.

Apparent Flexoelectricity Due to Heterogeneous Piezoelectricity

Recent work has highlighted how the phenomenon of flexoelectricity can masquerade as piezoelectricity. This notion can not only be exploited to create artificial piezoelectric-like materials without using piezoelectric materials but may also explain measurement artifacts in dielectrics. In this article, we show that the reverse is also possible and potentially advantageous in certain situations (such as energy harvesting). By constructing a computational homogenization approach predicated on the finite element method, we argue that composites made of piezoelectric phases can conspire to endow the material with a distinct overall flexoelectric-like response even though the native flexoelectricity of the constituent materials is negligible. Full finite element procedures for numerical evaluation of the different effective tensors, including the flexoelectric tensor, are provided. Numerical investigations are conducted, showing variation of the effective flexoelectric properties with respect to local geometry and properties of the composite in piezoelectric–piezoelectric and polymer–piezoelectric composites. We find that the flexoelectric response can be tuned to nearly five times higher than the constituents.

School’s Out: The Role of Summers in Understanding Achievement Disparities

Summer learning loss (SLL) is a familiar and much-studied phenomenon, yet new concerns that measurement artifacts may have distorted canonical SLL findings create a need to revisit basic research on SLL. Though race/ethnicity and socioeconomic status only account for about 4% of the variance in SLL, nearly all prior work focuses on these factors. We zoom out to the full spread of differential SLL and its contribution to students’ positions in the eighth-grade achievement distribution. Using a large, longitudinal NWEA data set, we document dramatic variability in SLL. While some students actually maintain their school-year learning rate, others lose nearly all their school-year progress. Moreover, decrements are not randomly distributed—52% of students lose ground in all 5 consecutive years (English language arts).

The Development of Materialism in Emerging Adulthood: Stability, Change, and Antecedents

The present study investigated stability and change in materialism in emerging adulthood as well as the predictive roles of socioeconomic status (SES) and gender on the development of materialistic values. Indicator-specific latent state-trait growth models were applied to four-wave longitudinal data from a sample of 738 Chinese college students. The results showed that materialism was stable: 67% to 86% of the variance in the reliable interindividual differences in materialism was due to trait factors. In addition, materialism showed an increasing trajectory over the college years, and this developmental trend could not be attributed to measurement artifacts or confounding influences. Moreover, low family SES magnified the increase in materialism, whereas being female predicted lower initial levels of materialism. Collectively, these findings illustrate the nature and antecedents of the development of materialism in emerging adulthood.

genuMet: distinguish genuine untargeted metabolic features without quality control samples

MotivationLarge-scale untargeted metabolomics experiments lead to detection of thousands of novel metabolic features as well as false positive artifacts. With the incorporation of pooled QC samples and corresponding bioinformatics algorithms, those measurement artifacts can be well quality controlled. However, it is impracticable for all the studies to apply such experimental design.ResultsWe introduce a post-alignment quality control method called genuMet, which is solely based on injection order of biological samples to identify potential false metabolic features. In terms of the missing pattern of metabolic signals, genuMet can reach over 95% true negative rate and 85% true positive rate with suitable parameters, compared with the algorithm utilizing pooled QC samples. genu-Met makes it possible for studies without pooled QC samples to reduce false metabolic signals and perform robust statistical analysis.Availability and implementationgenuMet is implemented in a R package and available on https://github.com/liucaomics/genuMet under GPL-v2 license.ContactLiming Liang: [email protected] informationSupplementary data are available at ….