Synthetic aperture radar sensitivity to forest changes: A simulations-based study for the Romanian forests

Natural and anthropogenic disturbances pose a significant threat to forest condition. Continuous, reliable and accurate forest monitoring systems are needed to provide earlywarning of potential declines in forest condition. To address that need, state-of-the-art simulationsmodelswere used to evaluate the utility of C-, L- and P-band synthetic aperture radar (SAR) sensors within an integrated Earth-Observation monitoring system for beech, oak and coniferous forests in Romania. The electromagnetic simulations showed differentiated sensitivity to vegetation water content, leaf area index, and forest disturbance depending on SAR wavelength and forest structure. C-band data was largely influenced by foliage volume and therefore may be useful for monitoring defoliation. Changes in water content modulated the C-band signal by b1 dBwhichmay be insufficient for a meaningful retrieval of drought effects on forest. Cband sensitivity to significant clear-cuts was rather low (1.5 dB). More subtle effects such as selective logging or thinning may not be easily detected using C- or L-band data with the longer P-band needed for retrieving small intensity forest disturbances. Overall, the simulations emphasize that additional effort is needed to overcome current limitations arising from the use of a single frequency, acquisition time and geometry by tapping the advantages of dense time series, and by combining acquisitions from active and passive sensors. The simulation results may be applicable to forests outside of Romania since the forests types used in the study have similar morphological characteristics to forests elsewhere in Europe.Romanian National Agency for Scientific Research and Innovation Authorit

How and why patterns of sexual dimorphism in human faces vary across the world

Sexual selection, including mate choice and intrasexual competition, is responsible for the evolution of some of the most elaborated and sexually dimorphic traits in animals. Although there is sexual dimorphism in the shape of human faces, it is not clear whether this is similarly due to mate choice, or whether mate choice affects only part of the facial shape difference between men and women. Here we explore these questions by investigating patterns of both facial shape and facial preference across a diverse set of human populations. We find evidence that human populations vary substantially and unexpectedly in both the magnitude and direction of facial sexually dimorphic traits. In particular, European and South American populations display larger levels of facial sexual dimorphism than African populations. Neither cross-cultural differences in facial shape variation, sex differences in body height, nor differing preferences for facial femininity and masculinity across countries, explain the observed patterns of facial dimorphism. Altogether, the association between sexual shape dimorphism and attractiveness is moderate for women and weak (or absent) for men. Analysis that distinguishes between allometric and non-allometric components reveals that non-allometric facial dimorphism is preferred in women’s faces but not in faces of men. This might be due to different regimes of ongoing sexual selection acting on men, such as stronger intersexual selection for body height and more intense intrasexual physical competition, compared with women

Conformational changes and metastable states induced in proteins by green light

In this paper we report conformational changes recorded on a protein molecule (α-amylase) under green light irradiation. In order to explain the experimental results we advanced the hypothesis that green light induces electric dipoles in the protein, which interact with each other, generating conformational modifications toward a more compact design, with different physical properties. The experiments were carried out with un-polarized light (λ = 520 nm) from a light-emitting-diode (1000 lm, 20 W, 105 mW on the target). In view of the character of our hypothesis, and corroborated with all our experimental results, we suggest that this phenomenon may be more extended and general, specific for a larger class of proteins, occurring on the protein macromolecules under the green light. The effects of α-amylase protein irradiation were revealed by circular dichroism, fluorescence, Raman and FTIR-spectroscopies, zeta potential, cyclic voltammetry, electric impedance spectroscopy and atomic force microscopy. Tentatively, we term the novel conformations as P∗ (polarized) proteins

Optical manipulation of complex molecular systems by high density green photons: experimental and theoretical evidence

The recent revolution in modern optical techniques revealed that light interaction with matter generates a force, known as optical force, which produces material properties known in physics as optical matter. The basic technique of the domain uses forces exerted by a strongly focused beam of light to trap small objects and subsequently to manipulate their local structures. The purpose of this paper is to develop an alternative approach, using irradiations with high-density-green-photons, which induce electric dipoles by polarization effects. The materials used for the experiments were long carbon chains which represent the framework of biological macromolecules. The physical techniques used to reveal the locally induced molecular arrangements were: dynamic viscosity, zeta potential, chemiluminescence, liquid chromatography; mass spectrometry, and Raman and infrared spectroscopy. The principal result of our experiments was the detection of different molecular arrangements within the mixture of alkane chains, generated by our optical manipulations. This induced “optical matter” displayed two material properties: antioxidant effects and large molecular aggregation effects. In order to bring the experimental results in relation with theory, we developed a physical model and the interacting force between polarizable bodies was computed. By numerical calculations stable structures for N = 6 and N = 8 particles were obtained

How and why patterns of sexual dimorphism in human faces vary across the world

Sexual selection, including mate choice and intrasexual competition, is responsible for the evolution of some of the most elaborated and sexually dimorphic traits in animals. Although there is clear sexual dimorphism in the shape of human faces, it is not clear whether this is similarly due to mate choice, or whether mate choice affects only part of the facial shape difference between men and women. Here we explore these questions by investigating patterns of both facial shape and facial preference across a diverse set of human populations. We find evidence that human populations vary substantially and unexpectedly in both the range and pattern of facial sexually dimorphic traits. In particular, European and South American populations display larger levels of facial sexual dimorphism than African populations. Neither cross-cultural differences in facial shape variation, differences in body height between sexes, nor differing preferences for facial sex-typicality across countries, explain the observed patterns of facial dimorphism. Altogether, the association between morphological sex-typicality and attractiveness is moderate for women and weak (or absent) for men. Analysis that distinguishes between allometric and non-allometric components reveals that non-allometric sex-typicality is preferred in women’s faces but not in faces of men. This might be due to different regimes of ongoing sexual selection acting on men, such as stronger intersexual selection for body height and more intense intrasexual physical competition, compared with women

Photocatalytic and Antibacterial Properties of Doped TiO₂ Nanopowders Synthesized by Sol−Gel Method

For environmental applications, nanosized TiO2-based materials are known as the most important photocatalyst and are intensively studied for their advantages such as their higher activity, lower price, and chemical and photoresist properties. Zn or Cu doped TiO2 nanoparticles with anatase crystalline structure were synthesized by sol−gel process. Titanium (IV) butoxide was used as a TiO2 precursor, with parental alcohol as a solvent, and a hydrolysing agent (ammonia-containing water) was added to obtain a solution with pH 10. The gels were characterized by TG/DTA analysis, SEM, and XPS. Based on TG/DTA results, the temperature of 500 °C was chosen for processing the powders in air. The structure of the samples thermally treated at 500 °C was analysed by XRD and the patterns show crystallization in a single phase of TiO2 (anatase). The surface of the samples and the oxidation states was investigated by XPS, confirming the presence of Ti, O, Zn and Cu. The antibacterial activity of the nanoparticle powder samples was verified using the gram−positive bacterium Staphylococcus aureus. The photocatalytic efficiency of the doped TiO2 nanopowders for degradation of methyl orange (MO) is here examined in order to evaluate the potential applications of these materials for environmental remediation

Distinctiveness and femininity, rather than symmetry and masculinity, affect facial attractiveness across the world

Studies investigating facial attractiveness in humans have frequently been limited to studying the effect of individual morphological factors in isolation from other facial shape components in the same population. In this study, we go beyond this approach by focusing on multiple components and populations while combining geometric morphometrics of 72 standardized frontal facial landmarks and a Bayesian statistical framework. We investigate preferences in both sexes for three structural components of other sex facial beauty that are traditionally considered indicators of biological quality: symmetry, sexual dimorphism, and distinctiveness (i.e., the opposite of averageness). Based on a large sample of faces (n=1550) from 10 populations across the world (Brazil, Cameroon, Czechia, Colombia, India, Namibia, Romania, Turkey, UK, and Vietnam), we found that distinctiveness negatively affects the perception of attractiveness in both sexes and that this association is stable across all studied populations. We corroborated some previous results indicating both a positive effect of femininity on male assessment of female facial beauty and a null or weak effect of masculinity on female evaluation of male facial attractiveness. Facial symmetry had no effect on facial attractiveness. In concert with other recent studies, our results support the importance of facial prototypicality but cast doubt on the role of symmetry as one of the key constituents of attractiveness in the human face