Deep Valleys Research Articles

As the World Struggles With the COVID-19 Pandemic, Another Emergency Threat Arrives on the Horizon, the Monkeypox: A Systematic Review.

The whole world got threatened by COVID-19, which made a significant loss in various sectors and pushed the world into a deep valley. Now a new threat, the emerging outbreak of monkeypox is rapidly spreading across the globe and is currently being observed in more than 110 countries with 79,473 confirmed cases and 50 deaths. Data were collected from PubMed, EMBASE, MEDLINE, Cochrane, Scopus database, African Journals OnLine, internet library sub-Saharan Africa, and Google Scholar. Most data were taken from the democratic Republic of Congo, the Central African Republic, Cameroon, the Republic of Congo, Liberia, Nigeria, the US, and the UK. Case reports, outbreak investigations, epidemiological studies, and surveillance studies were reviewed to find epidemiological details about the outbreak. A total of 50 peer-reviewed articles and 20 grey literature articles, including 9050 cases, were identified for data extraction. Our systematic review revealed that the group most affected is male (95.5%), with a median age of 33.8 years. A total of 55% of the transmission was sexually transmitted. The most commonly reported symptoms such as vesicular-pustular rashes (97.54%), fever (55.25%), inguinal lymphadenopathy (53.6%), exanthema (40.21%), fatigue, headache, asthenia (26.32%), myalgia (16.33%), vesicles and ulcers (30.61%) in the anogenital regions were some of the significant findings. The case fatality rate was observed to be up to 8.65%. The most affected country was the USA, which has the most fatalities in younger ages involved in homosexuality, suffering from HIV or sexually transmitted diseases (STDs).

A deep radius valley revealed by Kepler short cadence observations

ABSTRACT The characteristics of the radius valley, i.e. an observed lack of planets between 1.5 and 2 Earth radii at periods shorter than about 100 d, provide insights into the formation and evolution of close-in planets. We present a novel view of the radius valley by refitting the transits of 431 planets using Kepler 1-min short cadence observations, the vast majority of which have not been previously analysed in this way. In some cases, the updated planetary parameters differ significantly from previous studies, resulting in a deeper radius valley than previously observed. This suggests that planets are likely to have a more homogeneous core composition at formation. Furthermore, using support vector machines, we find that the radius valley location strongly depends on orbital period and stellar mass and weakly depends on stellar age, with $\partial \log {\left(R_{\rm p, \text{valley}} \right)}/ \partial \log {P} = -0.096_{-0.027}^{+0.023}$, $\partial \log {\left(R_{\rm p, \text{valley}} \right)}/ \partial \log {M_{\star }} = 0.231_{-0.064}^{+0.053}$, and $\partial \log {\left(R_{\rm p, \text{valley}} \right)}/ \partial \log {\left(\text{age} \right)} = 0.033_{-0.025}^{+0.017}$. These findings favour thermally driven mass-loss models such as photoevaporation and core-powered mass-loss, with a slight preference for the latter scenario. Finally, this work highlights the value of transit observations with a short photometric cadence to precisely determine planet radii, and we provide an updated list of precisely and homogeneously determined parameters for the planets in our sample.

Numerical and experimental investigation of a negative-curvature variable-shell flextensional transducer.

Type IV flextensional transducers do not have broadband characteristics due to the deep valley between their first- and second-order response curves arising from the sound pressure cancellation produced by the vibration in different areas of the shell. In this paper, the cause of the deep valley is examined by analyzing the equivalent radiated sound field of the transducer. Simplifying the three-dimensional vibration equation to a two-dimensional equation shows that the vibration state of the shell is related to the positive and negative curvature. Therefore, a variable-shell flextensional transducer with a negative curvature is proposed, which changes the second-order vibration of the transducer by introducing a negative curvature structure. The transducer avoids acoustic pressure cancellation, achieves broadband characteristics, and has continuous high efficiency in the frequency band. After optimization, a prototype of the transducer is fabricated and a pool test is completed. The test results show that the transducer realizes the coupling of the first three vibration mode, forming a broad band with an in-band fluctuation of less than 8 dB at 1200-5600 Hz, and the efficiencies of the first to third resonance peaks are 30.2 %, 16.6 %, and 9.4 %, respectively.

곡저추출 방법의 비교분석을 통한 산지유역 곡저추출 방법 제안

The mountain catchments where deep valley networks develop continuously are the main places for agriculture and forestry activities. Understanding the geomorphological characteristics of the valley is primarily needed for managing the natural landscapes in mountain catchments. With respect to the characterization of valley geomorphology, delineating the valley bottom is the most fundamental step. However, previous studies on valley bottom extraction focused on wide and unconfined valleys; they excluded colluvial valleys in headwater catchments. Here, we evaluated the suitability of two methods widely used to extract valley bottoms, specifically applying to a mountainous catchment where colluvial valleys dominate. Our results demonstrated that the Valley Confinement Algorithm (VCA) that delineates valley bottoms by adjusting flood height was more suitable than the Geomorphons-based method that extracts valley bottoms according to the topographic patterns corresponding to valley bottom morphologies. It is mainly because the Geomoprhons-based method should be applied differently to each valley type. In contrast, the VCA applies consistently to the whole area of the study catchment. The extracted valley bottom width is proportional to the power of the drainage area in this study area. In particular, the valley bottom width of fluvial valley increase more rapidly than that of colluvial valley.

LOW ALTITUDE GLACIAL RELICTS IN THE ROMANIAN FLORA

Glacial relicts represent isolated populations of cold-adapted species, remnants of their past extensive distribution at southern latitudes that have survived in situ far from their current main areal since the Ice Age ended. We hereby aim to identify, based on a numerical evaluation that uses a scoring system applied for 14 ecological and biogeographic criteria, putative glacial relicts occurring in lowland wetlands from the Romanian part of the Carpathian Region. Our selection of (sub) species for evaluation includes mainly cold-adapted plants occurring in wetland areas of the intra-mountain depressions and peripheral lowland areas, while those occurring mostly in the high mountain areas of the Carpathians were excluded. As a result, of 171 evaluated taxa, 74 are considered to possess stronger lowland glacial relict features in the Romanian flora. Furthermore, based on the evaluation of their distribution in Romania, we highlight the hotspots of richness, rarity and range limit for these taxa. Both richness and rarity indices calculated for the 74 glacial relicts displayed the highest values in the Eastern Carpathians, probably linked to the wider development in this region of intra-mountain depressions harboring extensive wetlands. In addition, several potential refugia have been identified based on the distribution of very rare taxa in the north-eastern part of the Apuseni Mountains and the eastern part of the Southern Carpathians (Bucegi Mountains). The distribution of range limit populations of glacial relicts in Romania outlines two well-demarcated areas, one in the southern part of the Eastern Carpathians and the second in the western part of the Southern Carpathians, along deep intra-mountain valleys and depressions. Due to their limited, isolated distribution and the fragility of wetland habitats in which they occur, populations of glacial relicts are more prone to be affected by impacts generated by human activities and climate change. Therefore, our study can also serve as a useful tool for enhancing conservation efforts by highlighting the lowland wetland areas harboring a high number of cold-adapted relict populations that require careful monitoring and urgent protection measures.

Using Remote Sensing Coupled with Analytic Hierarchy Process Approach for Evaluating Water Harvesting in Baglia Site

This research involves the application of spectral indices and GIS techniques coupled with the Analytic Hierarchy Process, to assess Baglia site, eastern Missan, as a water harvesting potential site. The AHP and pairwise comparison have been used through select four criteria including TWI, TRI, MNDWI, and NDSI, which were deemed as impact factors for this study. All these criteria have been weighted according to their significance in the water harvesting system. The findings of the AHP analysis method explained that the WH potential zones in Baglia site were divided into three zones, namely, high, medium, and low suitability. The findings demonstrate that Bglia site, where the highly appropriate zone is located in the deep valley area, is the ideal location for setting up water harvesting operations. The low suitability zone, in contrast, is located in a higher terrain when there is a steep slope area.

Geophysical assessment for deep structuring mapping and water resources perspectivity in semi-arid land region (northeastern Tunisia, Mediterranean Basin)

In Mediterranean semi-arid regions, shallow aquifers are generally over-exploited. However, several deeper groundwater boreholes exhibit serious problems of low hydraulic yield and dry wells. The existence of reliable information about the regional geological structure can enhance the success of deep well programmes. Geophysics has proved very useful as a fast and efficient tool to understand the structuring of deep hydrogeology aquifers. Indeed, the identification and characterization of the deep structures of the Bir Drassen–Sidi Toumi region (Cap-Bon, northeastern Tunisia) contribute to a better quantification of the groundwater potential, allowing more sustainable management. This province can be considered as the SW extension of the NE–SW Jebel Abderrahman Atlasic anticline, one of the most prominent geological structures in northeastern Tunisia. To identify the Miocene and Oligocene reservoirs, a geophysical study was carried out using advanced gravity analysis, supported by boreholes, and seismic and geoelectrical calibration. Different gravity filters were applied to reveal the sub-basin architecture and faulting network in the region. By calculating the maxima of the total horizontal gravity derivative and the distribution solutions for Euler's equations, a set of deep faults of different directions was divulged. Time-domain electromagnetic mapping illustrated the influence of these fault zones on the regional arrangement of sub-basin aquifers and their recharge processes. Finally, a 3D residual gravity inversion was carried out to better image the tectonically controlled depocentres associated with prolific thick fluvial–deltaic reservoirs. These ‘deep aquifer valley’ can be suggested as strategic targets for deep hydrogeological exploration planning.

Effect of quartic anharmonicity on the carrier transport of cubic halide perovskites CsSnI3 and CsPbI3

Recent years have witnessed the rising of halide perovskites for potential applications in photovoltaic and optoelectric devices. Due to the tilting motions of the octahedrons and rattling of the filling atoms, cubic halide perovskites show strong anharmonicity and imaginary frequencies in the phonon dispersion, which brings a great challenge to the prediction of carrier transports based on many-body theory. We have investigated the effect of quartic lattice anharmonicity on the carrier transports of cubic ${\mathrm{CsSnI}}_{3}$ and ${\mathrm{CsPbI}}_{3}$ in a comparative perspective by first-principles calculations. The hybrid functional of HSE06 was employed to get accurate band gaps and the self-consistent phonon method was used to renormalize interatomic force constants. Based on the electron-phonon Wannier interpolation and Boltzmann transport equation, the carrier mobilities and mode-resolved scattering rates were calculated and the dominant scattering channels were analyzed. Our results reveal that the mobility takes 595.9 and 84.5 ${\mathrm{cm}}^{2}/\mathrm{Vs}$ at room temperature for cubic ${\mathrm{CsSnI}}_{3}$ and ${\mathrm{CsPbI}}_{3}$, respectively, in good agreement with the experiment results. The longitudinal stretching mode of the Sn(Pb)-I bond with frequency of 120 ${\mathrm{cm}}^{\ensuremath{-}1}$ plays a dominant role in carrier scattering. In comparison, the acoustic modes and the rattling modes have a negligible effect on carrier scattering. Calculations of the band scattering rates show that deep valleys emerge at the band edges for both the highest valence band and the lowest conduction band, which is responsible for the slow relaxation of hot carriers. The strength of intraband electron-phonon coupling (EPC) between the band edge and the Sn(Pb)-I bond stretching mode is far larger than those of other modes, which leads to the dominant scattering in carrier transport. Compared with the harmonic approximation of atom interactions, the inclusion of quartic anharmonicity leads to the enhancement of atom interactions, which decreases the EPC strength and consequently increases the carrier mobilities.

A Scintillation Arc Survey of 22 Pulsars with Low to Moderate Dispersion Measures

Context. By providing information about the location of scattering material along the line of sight (LoS) to pulsars, scintillation arcs are a powerful tool for exploring the distribution of ionized material in the interstellar medium (ISM). Here, we present observations that probe the ionized ISM on scales of ∼0.001–30 au. Aims. We have surveyed pulsars for scintillation arcs in a relatively unbiased sample with DM < 100 pc cm−3. We present multifrequency observations of 22 low to moderate DM pulsars. Many of the 54 observations were also observed at another frequency within a few days. Methods. For all observations, we present dynamic spectra, autocorrelation functions, and secondary spectra. We analyze these data products to obtain scintillation bandwidths, pulse broadening times, and arc curvatures. Results. We detect definite or probable scintillation arcs in 19 of the 22 pulsars and 34 of the 54 observations, showing that scintillation arcs are a prevalent phenomenon. The arcs are better defined in low DM pulsars. We show that well-defined arcs do not directly imply anisotropy of scattering. Only the presence of reverse arclets and a deep valley along the delay axis, which occurs in about 20% of the pulsars in the sample, indicates substantial anisotropy of scattering. Conclusions. The survey demonstrates substantial patchiness of the ionized ISM on both astronomical-unit-size scales transverse to the LoS and on ∼100 pc scales along it. We see little evidence for distributed scattering along most lines of sight in the survey.

Insights Into Episodic Exhumation of the Western Tibetan Plateau Since the Late Cretaceous From Low‐Temperature Thermochronology

AbstractThe western Tibetan Plateau (TP) is characterized by low relief with high elevation separated by deep river valleys. When and how this characteristic topography developed remains ambiguous. Here, we present apatite (U‐Th)/He and fission‐track ages from three groups of samples with different geomorphic and geological settings. Thermal histories and exhumation rates were extracted from the thermochronological data. An early stage of exhumation (ca. 0.1 km/Ma) during 70–40 Ma was recorded by all samples, followed by slow exhumation (0.03–0.06 km/Ma) since the Eocene for the sample farthest away from faults and incised valley. The second stage of faster exhumation (ca. 0.13–0.15 km/Ma) during 30–23 Ma was revealed by samples from the hanging wall of thrust faults, whereas the third stage of exhumation during 15–12 Ma (ca. 0.1 km/Ma) was identified from samples in the Dingzi Zangbo valley. Combined with the regional geological setting, we propose that (a) the Late Cretaceous‐Early Eocene exhumation in the western TP was related to regional thrust‐induced crustal thickening and led to the formation of the proto‐TP; (b) the proto‐TP was modified by local structures and river incision. The Oligocene exhumation might be caused by local thrust activity, whereas the Miocene exhumation might be related to the transition from internal to external drainage. The continuous activity of the Karakoram fault resulted in another reorganization of drainage which led to the slow exhumation since 9 Ma. Our results highlight that tectonic and drainage network reorganization play an important role in shaping the geomorphology of the western TP.

Land Suitability Evaluation of Sorghum Planting in Luquan County of Jinsha River Dry and Hot Valley Based on the Perspective of Sustainable Development of Characteristic Poverty Alleviation Industry

Land suitability evaluation is the basis for optimizing and adjusting regional land use structure and layout, making scientific decisions, and planning, according to local conditions. It is also the basis for developing local characteristic poverty alleviation industries, and achieving sustainable development according to local conditions. However, existing research on the evaluation of land suitability rarely results in scientifically selecting the land resource area of a single crop, based on the principle of “suitable planting in the right place” and “suitable growth in the right place”; additionally, it does not conduct the land suitability evaluation of a single crop from the perspective of the sustainable development of the characteristic poverty alleviation industry. As the evaluation scope, this paper takes the dry and hot valley area of the Jinsha River, in Luquan County, Yunnan Province, as an example, selects eight evaluation factors, and organically combines the “limit condition method” and the “suitability index method”, determining 27,877.59 hectares of irrigated land, dry land, and other grasslands, below 1800 m above sea level in Luquan County in the Jinsha River basin. According to the principles of “suitable planting in the right place” and “suitable growth in the right place”, the suitability of sorghum planting land was evaluated. The evaluation results show that: the land area suitable for planting sorghum is 24,227.61 hectares, accounting for 86.91%. The area of land unsuitable for planting is 3649.98 hectares, and the area with a gradient over 25°, and obvious water and soil loss, accounts for 51.68% of the area of land being unsuitable for planting. The area of land unsuitable for planting is 48.32%, due to the restriction of soil thickness, soil texture, and bare rock, etc. The land that is not suitable for planting sorghum needs to be included in the scope of ecological protection. Compared with the 1200 hectares that have been developed and planted at present, there are still sufficient land resources suitable for planting sorghum. However, the area and proportion of land suitable for planting sorghum in different townships are quite different, so it is necessary to make a reasonable layout of the land suitable for planting sorghum according to local conditions. Among the land suitable for sorghum planting in the county, the proportion of the first, second, and third grade land suitable for sorghum planting is about 14:35:51. This shows that the area of first-class land suitable for planting is relatively small. This is because the terrain of the Jinsha River basin is characterized by: high mountains, steep slopes, deep valleys, little flat land, mainly mountains, shallow soil layers on slopes, and has poor texture. Therefore, there are many third-class suitable lands for planting with poor quality, and many reconstruction measures need to be taken to improve the quality of land suitable for planting.

Effects of Valley Topography on Acoustic Communication in Birds: Why Do Birds Avoid Deep Valleys in Daqinggou Nature Reserve?

To investigate the effects of valley topography on the acoustic transmission of avian vocalisations, we carried out playback experiments in Daqinggou valley, Inner Mongolia, China. During the experiments, we recorded the vocalisations of five avian species, the large-billed crow (Corvus macrorhynchos Wagler, 1827), common cuckoo (Cuculus canorus Linnaeus, 1758), Eurasian magpie (Pica pica Linnaeus, 1758), Eurasian tree sparrow (Passer montanus Linnaeus, 1758), and meadow bunting (Emberiza cioides Brand, 1843), at transmission distances of 30 m and 50 m in the upper and lower parts of the valley and analysed the intensity, the fundamental frequency (F0), and the first three formant frequencies (F1/F2/F3) of the sounds. We also investigated bird species diversity in the upper and lower valley. We found that: (1) at the distance of 30 m, there were significant differences in F0/F1/F2/F3 in Eurasian magpies, significant differences in F1/F2/F3 in the meadow bunting and Eurasian tree sparrow, and partially significant differences in sound frequency between the upper and lower valley in the other two species; (2) at the distance of 50 m, there were significant differences in F0/F1/F2/F3 in two avian species (large-billed crow and common cuckoo) between the upper and lower valley and partially significant differences in sound frequency between the upper and lower valley in the other three species; (2) there were significant differences in the acoustic intensities of crow, cuckoo, magpie, and bunting calls between the upper and lower valley. (3) Species number and richness were significantly higher in the upper valley than in the lower valley. We suggested that the structure of valley habitats may lead to the breakdown of acoustic signals and communication in birds to varying degrees. The effect of valley topography on acoustic communication could be one reason for animal species avoiding deep valleys.

Combined SBAS-InSAR and PSO-RF Algorithm for Evaluating the Susceptibility Prediction of Landslide in Complex Mountainous Area: A Case Study of Ludian County, China.

In complex mountainous areas where earthquakes are frequent, landslide hazards pose a significant threat to human life and property due to their high degree of concealment, complex development mechanism, and abrupt nature. In view of the problems of the existing landslide hazard susceptibility evaluation model, such as poor effectiveness and inaccuracy of landslide hazard data and the need for experts to participate in the calculation of a large number of evaluation factor weight classification statistics. In this paper, a combined SBAS-InSAR (Small Baseline Subsets-Interferometric Synthetic Aperture Radar) and PSO-RF (Particle Swarm Optimization-Random Forest) algorithm was proposed to evaluate the susceptibility of landslide hazards in complex mountainous regions characterized by frequent earthquakes, deep river valleys, and large terrain height differences. First, the SBAS-InSAR technique was used to invert the surface deformation rates of the study area and identified potential landslide hazards. Second, the study area was divided into 412,585 grid cells, and the 16 selected environmental factors were analyzed comprehensively to identify the most effective evaluation factors. Last, 2722 landslide (1361 grid cells) and non-landslide (1361 grid cells) grid cells in the study area were randomly divided into a training dataset (70%) and a test dataset (30%). By analyzing real landslide and non-landslide data, the performances of the PSO-RF algorithm and three other machine learning algorithms, BP (back propagation), SVM (support vector machines), and RF (random forest) algorithms were compared. The results showed that 329 potential landslide hazards were updated using the surface deformation rates and existing landslide cataloguing data. Furthermore, the area under the curve (AUC) value and the accuracy (ACC) of the PSO-RF algorithm were 0.9567 and 0.8874, which were higher than those of the BP (0.8823 and 0.8274), SVM (0.8910 and 0.8311), and RF (0.9293 and 0.8531), respectively. In conclusion, the method put forth in this paper can be effectively updated landslide data sources and implemented a susceptibility prediction assessment of landslide disasters in intricate mountainous areas. The findings can serve as a strong reference for the prevention of landslide hazards and decision-making mitigation by government departments.

How tectonic, volcanic and climatic processes in Andean ‘sky islands’ shaped the diversification of endemic ground beetles

AbstractAimThe Andean superpáramo ecosystem, above c. 4200 m a.s.l., currently forms an archipelago of isolated ‘sky islands’ which provides a unique setting to study biogeography. However, there is still a poor understanding of how past geological events, together with past climatic changes, have shaped the distribution of life in this ecosystem. Our aim was to investigate the importance of biogeographical barriers in local diversifications and to analyse how populations have become isolated on current ‘sky islands’.LocationNeotropics, Andes, Páramo, Ecuador.TaxonColeoptera, Carabidae, Platynini, Dyscolus.MethodsWe first used distributional data of 45 superpáramo specialist species to define areas of endemism in northern Ecuador. We then selected 34 currently isolated populations of 12 species to perform a high‐throughput genome skimming approach encompassing the complete mitogenome and the complete nuclear ribosomal cluster. We also generated a time‐calibrated estimation for the diversification of the group, and compared it to geochronological data.ResultsA high proportion (60%) of the sampled species are microendemic, being restricted to a single mountain summit. Three mutually exclusive areas of endemism are limited by deep transverse valleys across the Andes, and Pliocene speciation events are related to these orogenic barriers. The phylogeny obtained from the genome‐skimming approach provides a robust base to analyse the diversification of superpáramo endemic species and populations throughout the Plio‐Pleistocene.Main conclusionsThe opening of the Interandean Valley did not play a significant role in the diversification of the group prior to the Pleistocene. More recently, multiple populations have become isolated on the superpáramo of various volcanoes by independently colonizing this habitat during repeated cycles of glacial–interglacial periods. Our results highlight the joint contribution of orogeny and climatic fluctuations for explaining the current patterns of distribution. Each species had a different colonization history, with its populations reaching the different volcanoes at different glacial–interglacial cycles. Our approach also can provide a powerful tool to constrain the geological processes responsible for the topographic changes along and across the Cordillera.

Sinus rhythm endocardial mapping for channels identification in ischemic ventricular tachycardia using a modified electrophysiological triad

Abstract Background In a previous study it was demonstrated that an electrophysiological triad was able to identify critical isthmus in atrial flutter (AFL) patients. This triad is based in the Carto® electroanatomical mapping (EAM) version 7, which displays a histogram of the local activation times (LAT) of the tachycardia cycle length (TCL), in addition to the activation and voltage maps. Purpose This study aimed to prospectively assess the ability of a modified electrophysiological triad to identify and localize the ventricular tachycardia's (VT) channels and entrance zones during sinus rhythm mapping. Methods Prospective analysis of a unicentric registry of individuals who underwent ischemic VT ablation with Carto® EAM, all in sinus rhythm. All patients with non-ischemic etiology, lack of high-density EAM or lack of mapping in any of the left ventricle walls or structures were excluded. Areas of late potentials and possible channels of re-entry were compared to a modified electrophysiological triad constituted by: areas of low-voltage (&amp;lt;0.5mV), a site of deep histogram valley (LAT-Valley) with less than 20% density points relative to the highest density zone and a prolonged LAT-Valley duration that included 10% or more of the total activation time mapped. We also assessed the relationship between the pre-valley bar (the LAT histogram bar immediately before the prolonged LAT-Valley) and the channel entrances. Results A total of 14 patients (14 men, median age 70 IQR 64–78 years) were included. All patients presented with ischemic VT and 86% had a previous inferior myocardial infarction. The median number of collected points were 1733 (IQR 1363–2729). All sinus rhythm maps presented with at least 1 LAT-Valley in the analysed histograms. All arrhythmias were effectively treated after undergoing radiofrequency in the LAT-Valley location, either by blocking the channel entrances or scar homogenization ablation strategy. Also, the pre-valley bar in the histogram marked all the channel entrances in the scar borders. No patient had relapse after a clinical follow up of over 6 months. Conclusion In a prospective analysis, a modified electrophysiological triad was able to identify the scar channels in sinus rhythm in all patients. The pre-valley bar in the histogram disclosed the channel entrances. Further studies are needed to assess the usefulness of this algorithm to simplify catheter ablation and improve clinical outcomes. Funding Acknowledgement Type of funding sources: None.

Recognition of 3D Chiral Microenvironments for Myoblast Differentiation.

Cell chirality plays a critical role in the linkage between molecular chirality and the asymmetrical biological functions of body organs. However, enantioselective interactions between cell chirality and the extracellular environment are not yet fully understood. In this study, we investigated the effects of structurally chiral extracellular microenvironments on cellular alignments and differentiations. Twisted wrinkle-shaped chiral micropatterns were prepared using biaxial and asymmetric buckling methods, wherein structural handedness was determined from the orientation of the tilt angle between the first and second microwrinkles. Myoblasts were separately cultured on two enantiomeric chiral micropatterns in a mirror-reflected shape. Cells cultured on the left-handed chiral micropatterns preferred alignments along the direction of the second microwrinkle, with a relatively deeper valley than that of the first microwrinkle. The aligned cells on the left-handed pattern showed higher differentiation rates, as assessed by fusion indices and marker protein expression levels, than those cultured on right-handed chiral micropatterns. These results suggest that myoblasts exhibit enantioselective recognition of structurally chiral microenvironments, which can promote cellular alignments and differentiation.

Study on dispersion and attenuation of laser-induced surface acoustic wave by grinding surface roughness

The dispersion and attenuation of surface acoustic wave (SAW) are important indicators for evaluating the damage of machined surface layer. However, the dispersion and attenuation of SAW is also affected by surface roughness. The finite element method can simulate the rough surface without surface damage. Based on the measured surface profiles of roughness profiler, a series of grinding surfaces of C45E steel with different surface roughness Ra are simulated by finite element method, and the dispersion and attenuation of laser-induced SAW are studied. It is found that with the increase of roughness Ra, the increase of dispersion is relatively uniform, while the increase of attenuation not. The possible reason is that the dispersion is mainly affected by the average amplitude of roughness, while the occasional deep valley profile has a great influence on the attenuation. Compared with the experimental data, it is found that the velocity variation of 10–40 MHz SAW caused by Ra 0.12–0.75 μm surface roughness accounts for 8%–19% of the total velocity variation, and the proportion increases with the increase of roughness. The attenuation of 15 MHz SAW caused by surface roughness accounts for 8%–13% of the total attenuation. For a rough surface, dispersion is approximately linear with the frequency of SAW, while the attenuation coefficient increases sharply with the increase of frequency. Therefore, it is necessary to first evaluate the influence of surface roughness, especially the influence on attenuation, when the dispersion and attenuation of SAW are used to evaluate the machined surface damage. The results of this paper can be used to evaluate the influence of roughness on the dispersion and attenuation of SAW, and reduce the deviation in the evaluation of machined surface damage.

Landslide Susceptibility Mapping in Bitlis Province using GIS-based AHP method

This study presents the landslide susceptibility assessment of the region by considering the landslide-susceptible hazard factors such as slope, precipitation, soil, lithology, distance to the river, land use, elevation, aspect, and distance to active faults as well as historical landslide events and population throughout the province of Bitlis. For this purpose, a GIS-based Analytical Hierarchy Process (AHP) was used as an effective method in multiple decision-making methods. The results showed that approximately 25% of the study area has moderate to high landslide susceptibility. Accordingly, the landslide susceptibility of the study area is high, especially in the southwest and southeast parts of the study area which have mountainous and deep river valleys, and the partially mountainous regions in the north. Compared with previous landslide records and similar susceptibility maps in the literature, the results were found to be quite successful in determining landslide susceptibility of the study area. However, risk assessment wasn’t made within the scope of the study.

An innovation gain-adaptive Kalman filter for unmanned vibratory roller positioning

The precise positioning of an unmanned vibratory roller is the key to the compaction quality. Currently, many earth-rockfill dams are constructed in deep narrow valleys. Ultra-wide band (UWB) is widely used to overcome the partially denied problem of the global navigation satellite system. However, due to the complex noisy interference on construction sites, the accuracy of UWB is insufficient. To ensure the precise positioning of the unmanned vibratory roller, we propose an innovation gain-adaptive Kalman filter (IG-AKF) algorithm. The IG-AKF can adjust the noise covariance based on the relationship between the historical state statistics and positioning deviation. In addition, an attention decay mechanism that associates more attention to recent states is employed. Moreover, a diversity Harris hawks optimisation is proposed to optimise hyper-parameters in the IG-AKF. The proposed method was applied in Lianghekou project. Compared with UWB and the standard KF, the positioning accuracy of the IG-AKF was significantly improved.

From high peaks to deep valleys: Using a situation- and person-oriented approach to assess within- and between-student variation in momentary engagement and disengagement

The present study investigated the qualitatively different moments of engagement and disengagement experienced by students at upper-secondary school in academic situations. Further, we examined between-student differences in the occurrence of these moments and their associations with both momentary task performance and overall academic achievement. By means of multilevel latent profile analysis (MLPA) we examined 1392 momentary experiences of 130 students, collected via experience sampling method (ESM). We identified six types of (dis)engagement moments varying within students from moment to moment: high engagement, moderate engagement, indifferent engagement, anxious engagement, anxious disengagement and bored disengagement. In addition, we identified four student profiles: highly engaged, moderately engaged, indifferently engaged and anxious. Whereas the engagement moments were related to momentary task performance, there were no differences between the student profiles in academic achievement. These results shed light on the nuanced nature of engagement and disengagement, and how they vary across individuals and situations.