Unimodal Distribution Research Articles

Nanopowder synthesis enabling 1350 ºC full densification of (Gd,La)2O2S:Pr3+ luminescent ceramics via pressureless sintering and the effect of La3+ doping

Pr3+ activated Gd2O2S (Gd2O2S:Pr3+) ceramics are important scintillators for X-ray computed tomography, whose fabrication generally requires harsh sintering conditions, such as 1650–1750 °C for pressureless sintering and ∼1300–1500 °C and tens to hundreds MPa for pressure assisted sintering. We synthesized in this work a series of [(Gd1-xLax)0.99Pr0.01]2O2S (GLOS:Pr3+; x=0, 0,15, 0.3, 0.5, 0.65, 0.8, 1.0) nanopowders of fine crystallite size (∼19–54 nm), high specific surface area (∼13.4–15.8 m2/g) and unimodal size distribution through two-step calcination of coprecipitated amorphous precursors. Dilatometry analysis confirmed that the nanopowders possess excellent sinterability, and fully dense GLOS:Pr3+ ceramics were successfully fabricated via pressureless sintering in an Ar/H2 gas mixture at a temperature as low as 1350 °C. La3+ doping was found to substantially enhance densification/grain growth and the 3P0-3H4 main emission (∼510 nm) of Pr3+, and tends to elongate the fluorescence lifetime of the Pr3+ emission (∼1.89–2.66 μs).

On probabilistic mean value theorem and covariance identities

In this paper, further results for a probabilistic analogue of the mean value theorem proposed by Di Crescenzo (1999) are studied, focused on Normal and Poisson distributions. By applying this theorem for two normally distributed random variables with the same variance, a new symmetric unimodal distribution is obtained, and statistical measures of it are provided. By introducing a family of real valued continuous distributions, covariance identities are also investigated. Covariance identities are also explored for a Poisson distributed random variable. Some illustrative examples are finally given.

Flow synthesis of silver nanoparticles using water in supercritical CO2 emulsion

Rapid and continuous synthesis of metal nanoparticles using green solvent system is still a serious challenge for both fundamental and practical research. In this work, we report a new flow process using water in supercritical CO2 (w/scCO2) emulsion and applied it to the synthesis of silver nanoparticles (AgNPs). To investigate the performance of our system, AgNPs were synthesized by batch, flow and w/scCO2 emulsion flow system at 40 ºC while using AgNO3, NaBH(OAc)3, trisodium citrate and Aerosol-OT as precursor, reducer, stabilizer and emulsifier. As a result, we demonstrated that water droplets in w/scCO2 emulsion significantly contribute to a rise in the size controllability and productivity (product yield). Additionally, w/scCO2 emulsion flow process allowed the control of mean size from 4.0 to 36.6 nm and yield from 25% to 65% by changing the CO2 pressure and Aerosol-OT concentration. Furthermore, synthesized AgNPs successfully gave citrate-modified surface with high zeta potential of –54 mV and the transparent water dispersion with unimodal size distribution, showing promising potential to allow various practical applications.

Statistical mechanics of phenotypic eco-evolution: From adaptive dynamics to complex diversification

The ecological and evolutionary dynamics of large populations can be addressed theoretically using concepts and methodologies from statistical mechanics. This approach has been extensively discussed in the literature, both within the realm of population genetics, which focuses on genes or “genotypes,” and in adaptive dynamics, which emphasizes traits or “phenotypes.” Following this tradition, here we construct a theoretical framework allowing us to derive “macroscopic” evolutionary equations from a general “microscopic” stochastic dynamics representing the fundamental processes of reproduction, mutation, and selection in a large community of individuals, each one characterized by its phenotypic features. Importantly, in our setup, ecological and evolutionary timescales are intertwined, which makes it particularly suitable to describe microbial communities, a timely topic of utmost relevance. The framework leads to a probabilistic description—even in the case of arbitrarily large populations—of the distribution of individuals in phenotypic space as encoded in what we call the “generalized Crow-Kimura equation” or “generalized replicator-mutator equation.” We discuss the limits in which such an equation reduces to the (deterministic) theory of “adaptive dynamics,” i.e., the standard approach to evolutionary dynamics in phenotypic space. Moreover, we emphasize the aspects of the theory that are beyond the reach of standard adaptive dynamics. In particular, by developing a simple model of a growing and competing population as an illustrative example, we demonstrate that the resulting probability distribution can undergo “dynamical phase transitions.” These transitions may involve shifts from a unimodal distribution to a bimodal distribution, generated by an evolutionary branching event, or to a multimodal distribution through a cascade of evolutionary branching events. Furthermore, our formalism allows us to rationalize these cascades using the parsimonious approach of Landau's theory of phase transitions. Finally, we extend the theory to account for finite populations and illustrate the possible consequences of the resulting stochastic or “demographic” effects. Altogether, the present framework extends and/or complements existing approaches to evolutionary and adaptive dynamics and paves the way to more systematic studies of microbial communities as well as to future developments including theoretical analyses of the evolutionary process from the general perspective of nonequilibrium statistical mechanics. Published by the American Physical Society 2024

Shear-wave splitting associated with fluid processes beneath Styra, South Euboea: First results

The intense and persistent seismic activity on the Island of Euboea (or Evia) was a unique opportunity to study anisotropy in a region without any notable prior seismicity. The study area is located in the central-western Aegean Sea and constitutes the endpoint where the North Aegean Trough and four parallel dextral strike-slip fault branches terminate against the Greek mainland, along with their sinistral counterparts. Even though seismicity has been recorded around the island, the affected area close to the town of Styra has no known reported earthquakes. In 2022, surprising activity was initiated by two moderate earthquakes (ML 4.8 and ML 5.0) that occurred on 29 November and were felt as far as Athens. The activity continued well into the second quarter of 2023, with over 1000 microearthquakes being recorded. A pre-planned nearby temporary installation of a broadband instrument (GR27), in the context of the AdriaArray project, offered recordings of the activity. Here, we investigated the occurrence and cause of shear-wave splitting beneath Styra. Based on focal mechanisms of local earthquakes we inferred the stress axes. A fully automated process was used to analyze data for shear-wave splitting and determine the polarization direction of the Sfast (φ), the time-delay (td) and the normalized time-delay (tn). A total of 272 acceptable results showcased a unimodal distribution of φ with an average of N68°E and a mean td of 80 ms. We observed temporal variations of splitting parameters, associated with outbursts of seismicity, not with individual events. The determination of the shear-wave velocity anisotropy, jointly with observations of other splitting parameters, led us to hypothesize that anisotropy is the result of along-fault fluid processes. However, this would require a convincing selection of the NE-SW nodal plane as the preferred fault orientation. Further enrichment of the catalogue and an increase in splitting results is required to draw more robust conclusions.

Paleodepositional environments, lithostratigraphic bounding surfaces and basin-fill model of Mundeck Formation in Yabassi, NE Douala sub-basin

Lithofacies, sedimentologic and x-ray analytical techniques were employed to reconstitute paleodepositional environments, bounding surfaces and basin-fill model of Mundeck Formation during Lower Cretaceous in Yabassi, NE Douala sub-basin. The basin-fill comprises fissile gravel, sand and mud (GSF) facies from which eighteen sub-facies were identified and grouped under five facies associations (FA1-FA5). These correspond to alluvial settings (FA1), braided channels (FA2), cross-bedded tidal channels (FA3), ephemeral fluvio-lacustrine lake with short-lived marine incursion (FA4), fluvial channels with deeply incised erosional surfaces (FA5). Four hierarchical lithostratigraphic bed bounding surfaces were defined; incipient or intraformational hardgrounds, erosional surfaces abutted by ripped-up mud clasts, an obvious transgressive surface marked by the occurrence of ammonitic in lamellibranch and gastropod-rich silty-mudstones and shales. Humid and warm climates during Lower Cretaceous could be inferred from secondary mineral suites: clays (kaolinite, chlorite, illite and smectite); oxides (hematite and hydralsite); and oxy-hydroxides (goethite). Hematite-rich incipient hardgrounds surfaces depict warm and dry climates, while paleosols suggest channel abandonment, subaerial exposure and pedogenetic processes. Sediment transport regimes have evolved from low velocity cohesive flow regime in braided channels and overbank to high velocity and cohesion-less flow regime in multi-storey cross-bedded sand bars. Granulometric results reveal angular to sub-rounded, coarse-grained to gravelly clast sizes with unimodal, bimodal- and trimodal distributions, whereby all analyzed samples are positively skewed towards fine-grained sands. Morphoscopic analysis reveals 65–90% of very angular to angular and shinning quartz (VAAS), compared to 10–35% sub-angular and sub-rounded (SASR) and 0% rounded (R) shapes which indicate short transport distance from source areas. Sorting index (So) and deviation quartile (dQ) values of analyzed sands vary from 1.52 to 2.89, and 0.38–0.88 respectively and are indicative of moderate to very poor sorting.

Morphological and size tuning of biogenic Ag and Au nanoparticles induced by laser irradiation

Since size and shape of the metal nanoparticles (NPs) determine its physical and chemical properties, such could be relevant for specific applications; it is critical to have adequate control over such features. In this work, a facile bottom-up, bio-inspired synthetic route for noble metal nanoparticles (NPs) preparation is presented. Specifically, Ag and Au monometallic nanoparticles were synthesized by bio-reduction with Citrus paradisi (Grapefruit) aqueous extract. Besides, conventional chemical reduction synthesis using NaBH4 and PVP as capping agent was also performed for comparison purposes. Characterization accomplished by UV–vis spectroscopy and electron microscopy over the synthesized nanoparticles shown that, although that unimodal (in the case of Ag NPs) or almost unimodal (Au NPs) size distributions were obtained, thanks to stabilizing effect of the ligand acting-biomolecules present in the extract; and the narrower size distribution in comparison with the conventional chemical synthesis route were observed, several morphologies were found for both metals. In order to modify such features, the obtained noble metal NPs were submitted to pulsed (30 ps, 10 mJ) Nd:YAG laser irradiation process; after that, the spherical shape seems to be the predominant morphology in both metal nanoparticles, whereas the population of particles smaller than 15 nm became increases considerably.

Concept and ventilation performance demonstration of graded ventilation

Advanced air distribution is essential for the energy-efficient provision of thermal comfort and indoor air quality. This study proposes a novel advanced air distribution, i.e., graded ventilation. The airflow pattern of graded ventilation is characterized by a bimodal distribution of vertical air velocity and a unimodal distribution of vertical air temperature. Graded ventilation possesses four mechanisms for high energy-efficient provision of thermal comfort and indoor air quality. First, graded ventilation has a high conditioned air supply efficiency into the occupied zone, particularly the head level, for both thermal comfort and indoor air quality, due to the push-down and pull-down forces of the internal airflow recycling. Second, graded ventilation decouples outdoor fresh air and return air, with high outdoor fresh air supply efficiency for indoor air quality. Third, graded ventilation utilizes higher-quality conditioned air for the zone, which is more critical to thermal comfort and indoor air quality. Fourth, graded ventilation only handles the cooling load of the outdoor fresh air without handling the cooling load of the return air. Case studies demonstrate that compared with mixing ventilation, Type-I stratum ventilation, Type-II stratum ventilation, and interactive cascade ventilation, graded ventilation improves energy efficiency by 49.7%–55.4%, 24.8%–29.1%, 16.3%–23.3%, and 8.4%–12.3% respectively for thermal comfort and indoor air quality. Therefore, this study advances air distribution for low-carbon, thermally comfortable, and healthy buildings.

Stock assessment and reproductive biology of bluespotted seabream Pagrus caeruleostictus (family: Sparidae)

AbstractBluespotted seabream Pagrus caeruleostictus, a member of the family Sparidae, is one of the high‐priced seabream species in Ghana. Although the fish has been exploited in the Gulf of Guinea for over hundreds of years, there is scanty information on the state of the fish stock. Hence, we sought to investigate the exploitation status and aspects of the reproductive biology of the species by collecting monthly length and weight data for 18 months (February 2016 to July 2017). These data were fitted to growth and mortality models. The sexual maturity, fecundity and spawning seasons were also determined within the same period. The growth model of the fish revealed that the asymptotic length (L∞) and growth coefficient (K) values determined were 52.7 cm (total length) and 0.52 year−1, respectively. The mortality models also showed that the fishing mortality (F) of the fish was 2.20 year−1, whereas its natural mortality (M) was 0.83 year−1, with F/M > 0.5 indicating that the fish is over‐exploited. The lengths at first sexual maturity (Lm) of the males and females were 36.2 and 28.0 cm, respectively. Pagrus caeruleostictus, which was found to be highly fecund, had two spawning periods in a year, occurring in September and March, both with unimodal ova diameter frequency distributions. Based on these findings, we recommend that catch limits and other appropriate management measures (e.g. temporal and spatial closures) should be prescribed for the seabream fishery in the Gulf of Guinea to ensure the sustainability of the fishery.

363 Anatomic Study of Cervical Neural Foraminal Dimensions, Interpedicular Distance, and Disc Space Height From C2-T1 Using Computed Tomography of 1,000 Patients

INTRODUCTION: The normative relationships among cervical neuroforaminal dimensions (NFD), interpedicular distance (IPD), and disc space height (DSH) remain unknown. METHODS: We reviewed CT imaging of 1,000 patients between 18 and 35 years of age without spinal pathology to measure cervical NFD, defined as follows: foraminal height, sagittal anterior-to-posterior width, and area. Anterior, middle, and posterior DSH, and IPD were also measured. Interobserver reliability was assessed via the intraclass correlation coefficient (ICC) two-way mixed model on absolute agreement. RESULTS: Bilateral NFD followed bimodal distribution patterns moving caudally from C2-T1, whereas DSH measurements exhibited multimodal distribution patterns and IPD demonstrated a unimodal distribution clustered at the lower cervical spine. Significant differences were observed in NFD, DSH, and IPD measurements with respect to patient sex and race taking into consideration patient demographic and anthropometric characteristics. The African American cohort demonstrated the smallest NFD, DSH, and IPD measurements, followed by the Hispanic cohort, followed by the Caucasian cohort. Weak-to-moderate correlations were observed among NFD, DSH, and IPD measurements across all levels. CONCLUSIONS: This study describes 70,800 DSH, NFD, and IPD measurements from C2-T1 using CT imaging of young patients without spinal pathology. Findings from this study may provide normative guidelines necessary to establish the foundation for diagnosis of cervical neuroforaminal stenosis. Surprisingly, this study found no strong, or even moderate, correlations between normative NFD, DSH, and IPD measurements across all levels from C2-T1. Patient sex, ethnicity, and height are associated with NFD, DSH, and IPD, though patient weight is not.

170 Disc Space Height in Relation to Neural Foraminal Dimensions and Patient Characteristics: A Morphometric Analysis From L1-S1 Using Computed Tomography

INTRODUCTION: The normative relationship between lumbar intervertebral disc space height (DSH) and neuroforaminal dimensions (NFD) has yet to be defined. METHODS: Anterior, middle, and posterior DSH were measured on 350 female and 350 male patients between 18 and 35 years of age without spinal pathology. NFD were defined as sagittal anterior-to-posterior (AP) width, axial AP width, foraminal height, and area. Statistical analyses were performed to assess associations among DSH, NFD, and patient height, weight, body mass index, sex, and ethnicity. RESULTS: DSH measurements demonstrated increasing, linear trends moving caudally from L1-L2 to L5-S1, while NFD demonstrated a unimodal distribution pattern with largest NFD at L3-L4 and smallest NFD at L1-2 and L5-S1. Accounting for confounding due to height, weight, and ethnicity, male patients demonstrated larger DSH compared to female patients across all levels L1-S1 (p < .001). Asian patients demonstrated taller DSH compared to Caucasian, Hispanic, and African-American patients across all levels L1-S1 (p = .014). Zero moderate or strong correlations were observed between DSH and NFD measurements or patient characteristics for all levels L1-S1, though weight and foraminal height were weakly (r = .3) associated with increased DSH (p < .001). CONCLUSIONS: This study describes 38,500 CT-based L1-S1 disc space height and neuroforaminal measurements in young patients without spinal pathology. Among these patients, disc space height follows an increasing trend moving caudally from L1-S1, while foraminal dimensions demonstrate a unimodal distribution clustered at L3-L4. Neuroforaminal dimensions, including foraminal height, are not moderately or strongly associated with disc space height. Disc space height is influenced by sex and ethnicity but is not moderately or strongly influenced by patient height, weight, and BMI.

Spatiotemporal variability of streamflow in the Pearl River Basin: Controls of land surface processes and atmospheric impacts

AbstractTo advance understanding of the spatiotemporal variability of the streamflow in the Pearl River Basin (PRB), we used the Soil and Water Assessment Tool model to simulate the water fluxes from 2010 to 2020 and to identify the underlying controlling mechanisms. The streamflow in the PRB is highly variable and controlled by complex land surface processes and atmospheric impacts over the heterogeneous terrain. Two key factors primarily govern the streamflow: (1) the location of the active precipitation zone, which is determined by the interaction between the monsoon path and uplifting effect of the terrain, and (2) the redistributions resulting from land use and soil characteristics. We observe distinct patterns in the different water fluxes across the different regions. Specifically, surface flow exhibits the highest activity within the precipitation zone. Lateral flow and actual evapotranspiration (AET) have the greatest intensity in the forests and in agricultural regions, respectively, and the aquifer flow is more active in areas with coarse soil textures. The land surface processes of the AET and aquifer retention significantly govern the temporal variability of the streamflow, contributing to the precipitation and streamflow being out of phase in the PRB. Based on the underlying mechanisms driving streamflow variability, we classify the PRB into three substreams: a drought‐prone upstream, a hydrologically active midstream, and a typhoon‐affected downstream, and each substream exhibits distinct spatiotemporal characteristics of streamflow. We find that the time series and probability distributions of the streamflow at different tributaries within each substream are similar. Each probability distribution is multimodal and can be decomposed into three unimodal distributions representing dry, transitional, and wet conditions. Specifically, the PRB features a large and steep dry mode, a flat transitional mode, and a short wet mode.

Lake Surface Temperature Retrieval Study Based on Landsat 8 Satellite Imagery—A Case Study of Poyang Lake

Poyang Lake is the largest freshwater lake in China and forms an essential component of the hydrological, nutrient, and carbon cycles, providing various ecosystem services to the local environment. Since changes in Poyang Lake’s water temperature can significantly affect the surrounding environment and social development, continuous monitoring of lake temperature changes is required. Traditional water monitoring methods are resource intensive and cannot simultaneously conduct extensive water monitoring. Remote sensing of temperature inversion has the advantages of all-weather, efficient, and large-scale real-time monitoring. Six Landsat 8 images from August to October in 2020 and 2021 were utilized to extract lake surface temperature (LST), and the variations in LST over the two years were analyzed to determine the impact of global climate anomalies on inland lakes. The results indicate that the LST in August and October 2021 was significantly higher than that in the same periods of the previous year, and the temperature difference in October reached 8 °C. In contrast to the overall normal distribution pattern of the water temperature in 2020, 2021 exhibited a relatively concentrated, unimodal distribution pattern. A trend analysis of the driving factors suggests that the LST of Poyang Lake is influenced by the global climate, and the artificial heat sources around the lake clearly alter the distribution characteristics of the LST simultaneously.

Promotive effects of marine-derived dimethyl sulfoxide on the photodegradation of phenanthrene in the atmosphere

Dimethyl sulfoxide (DMSO), a versatile medium, is a particular component in the marine atmosphere that possibly causes polycyclic aromatic hydrocarbons (PAHs) to degrade differently than they do in the continental atmosphere. In this study, phenanthrene (Phe) was used as a model PAH in batch photochemical experiments to investigate the chemical actions of DMSO and the underlying mechanisms. The photodegradation of Phe in aqueous solutions with DMSO volume fractions from 0 % to 100 % was initiated by ultraviolet (UV) radiation and promoted by singlet oxygen, which was consistent with pseudo-first-order kinetics. Phe photodegraded faster in a mixture of DMSO and water than in water or DMSO alone, and the rate constant showed a unimodal distribution over the DMSO fraction range, peaking at 33 % DMSO (0.0333 ± 0.0009 min−1) and 40 % DMSO (0.0199 ± 0.0005 min−1) under 254 nm and 302 nm UV radiation, respectively. This interesting phenomenon was attributed to the competition of DMSO for UV radiation and singlet oxygen and changes in dissolved oxygen and free water contents caused by the interaction between DMSO and water molecules. In addition, 9,10-phenanthrenequinone (9,10-PhQ) with high cytotoxicity was the main photodegradation product of Phe under various conditions. The photodegradation rate of Phe in the mixtures of DMSO and water was comparable to its reaction rate with OH radicals, suggesting that 9,10-PhQ can be rapidly generated in the marine atmosphere, driven by a mechanism different from that in the continental or urban atmosphere. Under the presented experimental conditions, UV intensity and DMSO fraction were the primary factors that affected the photodegradation rate of Phe and 9,10-PhQ and altered their integrated toxicity. The findings of this study support the conclusion that the marine atmosphere is an essential field in the atmospheric transport of PAHs, in which DMSO is an important component that affects their photodegradation.

The fluidization behavior of particles in supercritical water fluidized bed: A region-dependent analysis

The distribution and fluctuation of particle concentration in a supercritical water fluidized bed (SCWFB) are studied using a specially-designed capacitance probe measurement system. The measurement error of capacitance probe system is 2.48%. Results show that the particle concentration at the axial line fluctuates largely with time and the fluctuation is weakened when increasing the distance from axial line or decreasing particle diameter. At Uf/Umb=1.5, the largest difference between particle concentrations is 0.026, 0.04, 0.082 when the particles with a diameter of 0.124 mm, 0.198 mm, 0.235 mm are used, indicating a larger non-uniformity of larger particles. The probability density of local particle concentration mainly follows a unimodal distribution with the peak at right side. The main frequency of SCWFB ranges from 1.39 Hz to 2.73 Hz in this experiment and the main frequency decreases when larger particles are used.

Mannose-Decorated Solid-Lipid Nanoparticles for Alveolar Macrophage Targeted Delivery of Rifampicin.

Alveolar macrophages play a vital role in a variety of lung diseases, including tuberculosis. Thus, alveolar macrophage targeted anti-tubercular drug delivery through nanocarriers could improve its therapeutic response against tuberculosis. The current study aimed at exploring the efficacy of glyceryl monostearate (GMS)-based solid-lipid nanoparticles (SLNs) and their mannose functionalized forms on the alveolar macrophage targeting ability of an anti-tubercular model drug, rifampicin (Rif). Rif-loaded SLNs were accomplished by the solvent diffusion method. These carriers with unimodal particle size distribution (~170 nm) were further surface-modified with mannose via Schiff-base reaction, leading to slight enhancement of particle diameter and a decline of drug loading capacity. The encapsulated Rif, which was molecularly dispersed within the matrices as indicated by their XRD patterns, was eluted in a sustained manner with an initial burst release effect. The uptake efficiency of mannose-modified SLNs was remarkably higher than that of corresponding native forms on murine macrophage Raw 264.7 cells and human lung adenocarcinoma A549 cells. Eventually, the mannose-modified SLNs showed a greater cytotoxicity on Raw 264.7 and A549 cells relative to their unmodified forms. Overall, our study demonstrated that mannose modification of SLNs had an influence on their uptake by alveolar macrophages, which could provide guidance for the future development of alveolar macrophage targeted nanoformulations.

Oil-in-water nanoemulsions loaded with lycopene extracts encapsulated by spray drying: Formulation, characterization and optimization

Lycopene is very susceptible to degradation once released from the protective chromoplast environment. In this study the oil-in-water (O/W) nanoemulsions coupled with spray drying technology was applied for the encapsulation and stabilization of lycopene extracted from tomato waste. Tomato extract was obtained by ultrasound-assisted extraction. Nanoemulsions were prepared by high-speed rotor stator using isopropyl myristate as oil phase and Pluronic F-127 as emulsifier for the aqueous external phase. The effect of emulsification process parameters was investigated. Spray drying of produced emulsions was attempted to obtain a stabilized dry powder after the addition of a coating agent. The effect of different coating agents (maltodextrin, inulin, gum arabic, pectin, whey and polyvinylpyrrolidone), drying temperature (120–170 °C) and feed flow rate (3–9 ml·min–1) on obtained particles was evaluated.Results revealed that the emulsion formulation of 20/80 (O/W) with 1.5% (mass fraction) of Pluronic F-127 as stabilizer in the aqueous phase resulted in stable nanoemulsion with droplets size in the range (259–276 nm) with unimodal and sharp size distribution. Extract in the nanoemulsion was well protected at room temperature with a degradation rate of lycopene of about 50% during a month of storage time. The most stable emulsions were then processed by spray drying to obtain a dry powder. The spray drying was in particular successful when using maltodextrin as coating agent, obtaining dried spherical particles with mean diameters of 4.87±0.17 μm with a smooth surface. The possibility of dissolving the spray dried powder in order to repristinate. The original emulsion was also successfully verified.

Early Miocene sand wedge deposits in Southwestern Tarim Basin and Implications for the Uplift of the Northern Tibetan Plateau

The uplift of the Tibet Plateau and its climatic effects have long been a hot topic in academic research. However, there is still significant controversy regarding the uplift history and related climate changes along the northern margin of the plateau. In this paper, we present sand wedge deposits from the base of the Wuqia Group (∼20 Ma) on the southwestern Tarim Basin, representing the oldest reported sand wedges in the Tibetan Plateau. A comprehensive study was conducted on lithostratigraphy, sedimentary environment, and macroscopic–microscopic features of the sand wedge deposits. The results indicate that the lithostratigraphic succession preserving the sand wedge deposits consists mainly of lenticular conglomerates and cross-bedded gravelly sandstone interbedded with medium–thin-bedded mudstone, consistent with the braided fluvial environment. The sand wedge deposits commonly exhibit a V-shape geometry and are filled with gravelly sandstone, with the gravels arranged parallel to the walls of the wedge. The clasts of the wedge-filled sandstone are well-rounded and show a unimodal grain size distribution. The quartz surfaces commonly display dish-shaped and crescent-shaped impact features, indicating an eolian origin and an arid climate. Based on the relationship between the formation temperature of modern sand wedges, the atmospheric temperature gradient, and altitude, the reconstructed paleo-elevation of the sand wedge deposits at the base of the Wuqia Group in the southwestern Tarim Basin is approximately ∼ 1000 m. These results indicate that the northern margin of the Tibet Plateau had already reached an elevation of ∼ 1000 m during the Early Miocene, forming a seasonal arid and cold climate.

The Flexible Gumbel Distribution: A New Model for Inference about the Mode

A new unimodal distribution family indexed via the mode and three other parameters is derived from a mixture of a Gumbel distribution for the maximum and a Gumbel distribution for the minimum. Properties of the proposed distribution are explored, including model identifiability and flexibility in capturing heavy-tailed data that exhibit different directions of skewness over a wide range. Both frequentist and Bayesian methods are developed to infer parameters in the new distribution. Simulation studies are conducted to demonstrate satisfactory performance of both methods. By fitting the proposed model to simulated data and data from an application in hydrology, it is shown that the proposed flexible distribution is especially suitable for data containing extreme values in either direction, with the mode being a location parameter of interest. Using the proposed unimodal distribution, one can easily formulate a regression model concerning the mode of a response given covariates. We apply this model to data from an application in criminology to reveal interesting data features that are obscured by outliers.

Does the temperature–size rule apply to idiobiont parasitoids?

AbstractIn most ectotherms, several life‐history traits, including body size, respond to environmental conditions through the temperature–size rule (TSR). The mechanisms underlying the TSR are still being debated, but studying idiobiont insect parasitoids, which develop with a fixed amount of resources, may shed light on this relationship. In this study, we conducted experiments to determine how the developmental temperature affects various characteristics of male and female Trichogramma euproctidis (Girault) (Hymenoptera: Trichogrammatidae), an idiobiont egg parasitoid of Lepidoptera. The study tested various hypotheses, including the cellular or oxygen diffusion hypotheses and the resource acquisition hypothesis, to understand whether T. euproctidis follows the TSR. The developmental time of both male and female T. euproctidis decreased with increasing temperature. Both males and females displayed a unimodal distribution for size, dry mass, and lipid content, with individuals at lower and higher temperatures being smaller, weighing less, and containing fewer lipids. Female lifetime fecundity increased from 13 to 24 °C and then decreased at 31 °C. Additionally, the number and size of gametes in male and female T. euproctidis displayed a unimodal distribution with increasing temperature. Trichogramma euproctidis deviates from the TSR as it follows a non‐linear reaction norm with an optimal developmental temperature. This result supports the hypothesis that for species following TSR and having unlimited access to food resources, the resource acquisition hypothesis is a significant mechanism explaining the TSR. With climate change affecting temperature, understanding the TSR is crucial, and research on insect parasitoids may help reveal how the interplay between environmental temperature and resource allocation affects the TSR in natural populations.