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The material emitted from a target surface during laser ablation generates a net thrust (propulsion) in the opposite direction. The momentum generation efficiency of this laser-driven propulsion is given by the mechanical coupling coefficient (Cm). In this work, we considered nanosecond UV laser ablation of the aluminum 6061 alloy to study the Cm behavior with different irradiating conditions. This is done by systematically changing fluence, uniform/nonuniform intensity, and incident angle of the laser beam. In particular, we found that when dealing with nonuniform laser intensity, characterizing Cm exclusively in terms of fluence is not fully satisfactory because the energy distribution over the irradiated area plays a key role in the way material is removed-interplay between vaporization and phase explosion-and thrust is generated.
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The genus Apteromantis Werner, 1931 comprises two species of wingless mantids, the Iberian A. aptera (Fuente, 1894) and the North African A. bolivari (Werner, 1929). Although A. aptera and A. bolivari have been traditionally considered as separate and valid species, their external appearance is quite similar and no comprehensive taxonomic study has analyzed their morphological and genetic characteristics. This taxonomic uncertainty has important implications for conservation because A. aptera is considered an Iberian endemic and the only praying mantis protected by international laws. In this study, we apply a comprehensive approach, including quantitative morphological and molecular analyses, to shed new light on the taxonomic and conservation status of the genus Apteromantis and the putative species. We have found that the Iberian and North African specimens analyzed herein significantly differ in female head shape, male genitalia morphology and several other traits related to body size. Molecular data suggest the presence of two main lineages, with sequence divergence rates of approximately 4 %, which are within the range reported for other well defined insect species. Overall, this study supports that A. aptera and A. bolivari are valid species despite their ecological and morphological similarity and highlights the importance of comprehensive approaches to resolve old taxonomic and conservation problems.
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Conservación de los Recursos Naturales , Mantódeos/anatomía & histología , Mantódeos/clasificación , Animales , Femenino , Masculino , Mantódeos/genética , Mantódeos/fisiología , Filogenia , Especificidad de la EspecieRESUMEN
Background: Blepharopsis mendica (Fabricius, 1775) is a large mantid species found from the Canary Islands across North Africa, the Middle East, and Pakistan. Research on this species has been limited, especially in Iran, despite the country's potential significance for studying its biology and distribution. Adults of this species are easily recognizable by their marble-white pattern and rhomboidal leaf-like pronotum. They are sit-and-wait predators that inhabit various open environments. Methods: Field observations were conducted across various regions of the Egyptian Flower mantis (Blepharopsis mendica) global distribution, with a focus on Morocco, Tunisia, and Iran. Distribution data for B. mendicawere gathered from fieldwork, museum collections, online biodiversity databases, and publications, totaling 593 occurrence points. Ecological niche modeling was performed using environmental data, and various models were evaluated for suitability. Phylogeographic analyses involved DNA sequencing and construction of a haplotype network to examine genetic relationships between populations. Divergence time estimation and biogeographical range expansion models were applied to explore historical distribution shifts of the species across different regions. The study provided comprehensive insights into the biology, distribution, and genetic history of B. mendica. Results: We provide information on the life cycle, ootheca, defense behavior, habitat, and biogeography of the Egyptian Flower mantis Blepharopsis mendica. This mantid is an overwintering univoltine species with nymphs emerging in summer and becoming adults in spring. In the wild, females start oviposition in April and can lay their first ootheca within a week after mating. The species is distributed from the Canary Islands to Pakistan in the dry belt. Thus, its distribution is associated with xeric areas or desert and semi-desert habitats. Phylogeographic analyses revealed three major genetic lineages, (i) in the Maghreb, (ii) from Egypt via Arabia to Iran (with internal substructures), and (iii) likely in Pakistan; the estimated onset of differentiation into these lineages is of Pleistocene age. Defense behavior involves flying away or extending wings broadly and lifting forelegs. Performing laboratory breeding, we documented life cycle and color changes from first instar to adulthood. Due to overwintering, the last larval instar needs considerably longer than the others. At 25 °C (±2), average adult life span was 118 days (±6 SD) for females (range: 100-124) and 46 days (±5 SD) for males (range: 39-55), with a significant difference among sexes. On average, oothecae contained 32.3 eggs (±10.1 SD) and the mean incubation period was 36.8 days (±2.9 SD). We did not find evidence of parthenogenesis. In general, the biology of B. mendica shows a variety of adaptations to its often extreme and little predictable type of habitat.
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Mantódeos , Animales , Femenino , Masculino , Ecología , Ecosistema , Insectos , Mantódeos/química , TúnezRESUMEN
The upper portions of the Earth's atmospheric layer, e.g., the ionospheric plasma layer, can be significantly affected by perturbations generated in the lower layers. In fact, all perturbations formed within the troposphere can easily propagate, not only horizontally within the layer but also vertically reaching the highest regions of the atmosphere far from the Earth's surface, as depicted by the Wentzel-Kramers-Brillouin (WKB) approximation of atmospheric waves. Because all perturbations generated in the atmospheric boundary layer must take into account the effects of the medium's nonlinearity and thus the effects of atmospheric turbulence, in this work the impact of a strong seismic event and the disturbances generated in the flow are analyzed by means of a fully nonlinear model which incorporates a simple parametrization of the seismic event and is based on the classical shallow water. A strict dependence was observed between the model control parameters and the vertical nonvanishing modes from the WKB approximation, and only few specific bands of excited modes are nonvanishing and can eventually propagate to the ionosphere. Moreover, the flow disturbance, generated by a seismic event, presents a multiscale nature characterized by two fixed wavelengths, and the excited modes are harmonics of such distinctive scales.
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BACKGROUND: Pressure/volume (P/V) loops provide useful information on left ventricular performance and prognosis in patients with heart failure (HF) but do not lend themselves to routine clinical practice. The authors developed a noninvasive method to compute individualized P/V loops to predict adverse clinical outcomes in patients with stable HF, which the authors believe can be used clinically. METHODS: A derivation cohort (n = 443 patients) was used to develop an echocardiography P/V loop model, using brachial arterial pressure and trans-thoracic two-dimensional Doppler echocardiographic data. Each patient's P/V loop was depicted as an irregular pentagon, and a centroid was derived for each loop. The centroid distance (CD) from a reference centroid (derived from 101 healthy control subjects) was computed. This model was prospectively applied to 435 patients who constituted the validation cohort. The study end point was a composite of cardiac death or hospitalization for HF among study patients. RESULTS: In the derivation cohort, CD was threefold greater among patients who experienced adverse events than those who did not. During a follow-up period of 30 months (15-45 months), event rates were 35% (72 of 206 patients) and 12% (29 of 237 patients P < .001), respectively, among patients with CD > 33 mL/mm Hg and those with CD ≤33 mL/mm Hg (prognostic cutoff derived by receiver operating characteristic analysis). Multivariate Cox analysis identified CD as an independent predictor of adverse outcome (hazard ratio, 1.61; 95% CI, 1.03-2.50) independently of left ventricular end-diastolic volume, pulmonary capillary wedge pressure, and left ventricular ejection fraction. These conclusions were confirmed in the validation cohort. CONCLUSIONS: The authors propose a method to create a noninvasive P/V loop and its centroid. These data provide useful pathophysiologic and prognostic information in patients with HF.
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Insuficiencia Cardíaca , Función Ventricular Izquierda , Humanos , Volumen Sistólico/fisiología , Función Ventricular Izquierda/fisiología , Pronóstico , Ecocardiografía/métodos , Insuficiencia Cardíaca/diagnóstico por imagenRESUMEN
Earth's atmosphere, whose ionization stability plays a fundamental role for the evolution and endurance of life, is exposed to the effect of cosmic explosions producing high energy Gamma-ray-bursts. Being able to abruptly increase the atmospheric ionization, they might deplete stratospheric ozone on a global scale. During the last decades, an average of more than one Gamma-ray-burst per day were recorded. Nevertheless, measurable effects on the ionosphere were rarely observed, in any case on its bottom-side (from about 60 km up to about 350 km of altitude). Here, we report evidence of an intense top-side (about 500 km) ionospheric perturbation induced by significant sudden ionospheric disturbance, and a large variation of the ionospheric electric field at 500 km, which are both correlated with the October 9, 2022 Gamma-ray-burst (GRB221009A).
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Significant evidence of ionosphere disturbance in connection to intense seismic events have been detected since two decades. It is generally believed that the energy transfer can be due to Acoustic Gravity Waves (AGW) excited at ground level by the earthquakes. In spite of the statistical evidence of the detected perturbations, the coupling between lithosphere and atmosphere has not been so far properly explained by an accurate enough model. In this paper, for the first time, we show the result of an analytical-quantitative model that describes how the pressure and density disturbance is generated in the lower atmosphere by the ground motion associated to earthquakes. The direct comparison between observed and modelled vertical profiles of the atmospheric temperature shows the capability of the model to accurately reproduce, with an high statistical significance, the observed temperature fluctuations induced by strong earthquakes.
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Earthquakes have become one of the leading causes of death from natural hazards in the last fifty years. Continuous efforts have been made to understand the physical characteristics of earthquakes and the interaction between the physical hazards and the environments so that appropriate warnings may be generated before earthquakes strike. However, earthquake forecasting is not trivial at all. Reliable forecastings should include the analysis and the signals indicating the coming of a significant quake. Unfortunately, these signals are rarely evident before earthquakes occur, and therefore it is challenging to detect such precursors in seismic analysis. Among the available technologies for earthquake research, remote sensing has been commonly used due to its unique features such as fast imaging and wide image-acquisition range. Nevertheless, early studies on pre-earthquake and remote-sensing anomalies are mostly oriented towards anomaly identification and analysis of a single physical parameter. Many analyses are based on singular events, which provide a lack of understanding of this complex natural phenomenon because usually, the earthquake signals are hidden in the environmental noise. The universality of such analysis still is not being demonstrated on a worldwide scale. In this paper, we investigate physical and dynamic changes of seismic data and thereby develop a novel machine learning method, namely Inverse Boosting Pruning Trees (IBPT), to issue short-term forecast based on the satellite data of 1371 earthquakes of magnitude six or above due to their impact on the environment. We have analyzed and compared our proposed framework against several states of the art machine learning methods using ten different infrared and hyperspectral measurements collected between 2006 and 2013. Our proposed method outperforms all the six selected baselines and shows a strong capability in improving the likelihood of earthquake forecasting across different earthquake databases.
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The presence of the Indochina mantis Hierodula patellifera (Mantidae, Mantinae) as a new alien species in Italy is reported, with the description of the first stable macro-population in Europe. This macro-population shows a wide distribution, comprising several fragmented and reproducing sub-populations in Northern Italy and one in Southern France. Specimens and individuals were collected or observed on trees and ornamentals in urban ecosystems with the help of citizen science. A spatial analysis (Average Nearest Neighbour) was undertaken to characterise the present distribution pattern, evidencing the hot spots of arrival and the local spreading process. The random pattern of presence in the local urban textures and the resistance of this species to the challenging North Italian climate, are here discussed in the perspective of a future expansion to central and Northern Europe, using probably the main railways to arrive at depots and cities, travelling with Asian goods. Identification characters are also presented to separate this alien species from the other species of the subfamily Mantinae, native or introduced, present in Europe.
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A high performance apparatus has been designed and built by the H8-RD22 collaboration for the study of channeling and volume reflection phenomena in the interaction of 400 GeV/c protons with bent silicon crystals, during the 2006 data taking in the external beamline H8 of the CERN SPS. High-quality silicon short crystals were bent by either anticlastic or quasimosaic effects. Alignment with the highly parallel (8 murad divergence) proton beam was guaranteed through a submicroradian goniometric system equipped with both rotational and translational stages. Particle tracking was possible by a series of silicon microstrip detectors with high-resolution and a parallel plate gas chamber, triggered by various scintillating detectors located along the beamline. Experimental observation of volume reflection with 400 GeV/c protons proved true with a deflection angle of (10.4+/-0.5) murad with respect to the unperturbed beam, with a silicon crystal whose (111) planes were parallel to the beam.
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Species in the genus Ameles Burmeister and Pseudoyersinia Kirby (Amelini) are traditionally defined as small-sized, ground-dwelling mantids whose males are distinct for being, respectively, macropterous and brachypterous. However, comparative morphological studies across Amelini confirmed the existence of short-winged males in Ameles, suggesting that this traditional diagnostic concept does not apply to all species. Our analyses of several species from West Mediterranean localities (Canary Islands, Spain, Italy, and Morocco) resulted in the relocation of Pseudoyersinia andreae Galvagni, 1976 to Ameles as Ameles andreae (Galvagni, 1976) (n. comb.) with Ameles insularis Agabiti, Ippolito Lombardo, 2010 as its new synonym (n. syn.), the clarification of the taxonomic identity of A. gracilis (Brullé, 1838) and A. maroccana Uvarov, 1931, including diagnoses of their males, and the description of Ameles spallanzania obscura (n. ssp.) (from Spain). We also take the opportunity to describe Pseudoyersinia maroccana (n. sp.) (from Morocco) based on museum specimens separating it from Ameles maroccana Uvarov, 1931. We also found that wing length is positively correlated to ocelli size. We discuss this trend from an ecological, evolutionary, and biogeographic perspectives to both facilitate species circumscription and justify the taxonomic modifications herein introduced.
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Mantódeos , Animales , Insectos , Italia , Masculino , Marruecos , EspañaRESUMEN
A manned mission to Mars would present an important long-term health risk to the crew members due to the prolonged exposure to the ionizing radiation of galactic cosmic-rays. The radiation levels would largely exceed those encountered in the Apollo missions. An increase in the passive shielding provided by the spacecraft implies a significant increase of the mass. The advent of superconducting magnets in the early 1960s was considered an attractive alternative. The technology allows to generate magnetic fields capable to deflect the cosmic-rays in a manner analogous to the reduction of the particle fluxes in the upper atmosphere due to the Earth's dipole magnetic field. A series of the three studies have been conducted over the last 5 years, funded successively by European Space Agency (ESA), the NASA Innovative Advanced Concepts (NIAC) program, and the Union European's Seventh Framework Programme (FP7). The shielding configurations studied are based on high-temperature superconductors, which eliminate the need to operate with liquid helium. The mass estimates of the coils and supporting structure of the engineering designs are based on the current and expected near-future performance of the superconducting materials. In each case, the shield performance, in terms of dose reduction, is provided by a 3-dimensional Monte Carlo simulation, which treats in detail the electromagnetic and hadronic interactions of the galactic-cosmic rays, and the secondary particles they produce in the materials of the shield and spacecraft. A summary of the results of the studies, representing one of the most detailed and comprehensive efforts made in the field, is presented.
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The volume reflection phenomenon was detected while investigating 400 GeV proton interactions with bent silicon crystals in the external beam H8 of the CERN Super Proton Synchrotron. Such a process was observed for a wide interval of crystal orientations relative to the beam axis, and its efficiency exceeds 95%, thereby surpassing any previously observed value. These observations suggest new perspectives for the manipulation of high-energy beams, e.g., for collimation and extraction in new-generation hadron colliders, such as the CERN Large Hadron Collider.