Contrasting Behavior Research Articles

Contrasting germination behavior of nodding broomrape towards soybean seeds- and sprouts-extract is associated with their corresponding phytohormones, sugars and isoflavones contents

Contrasting germination behavior of nodding broomrape towards soybean seeds- and sprouts-extract is associated with their corresponding phytohormones, sugars and isoflavones contents

Contrasting behavior of urea in strengthening and weakening confinement effects on polymer collapse.

Biomolecules inhabit a crowded living cell that is packed with high concentrations of cosolutes and macromolecules that result in restricted, confined volumes for biomolecular dynamics. To understand the impact of crowding on the biomolecular structure, the combined effects of the cosolutes (such as urea) and confinement need to be accounted for. This study involves examining these effects on the collapse equilibria of three model 32-mer polymers, which are simplified models of hydrophobic, charge-neutral, and uncharged hydrophilic polymers, using molecular dynamics simulations. The introduction of confinement promotes the collapse of all three polymers. Interestingly, addition of urea weakens the collapse of the confined hydrophobic polymer, leading to non-additive effects, whereas for the hydrophilic polymers, urea enhances the confinement effects by enhancing polymer collapse (or decreasing the polymer unfolding), thereby exhibiting an additive effect. The unfavorable dehydration energy opposes collapse in the confined hydrophobic and charge-neutral polymers under the influence of urea. However, the collapse is driven mainly by the favorable change in polymer-solvent entropy. The confined hydrophilic polymer, which tends to unfold in bulk water, is seen to have reduced unfolding in the presence of urea due to the stabilizing of the collapsed state by urea via cohesive bridging interactions. Therefore, there is a complex balance of competing factors, such as polymer chemistry and polymer-water and polymer-cosolute interactions, beyond volume exclusion effects, which determine the collapse equilibria under confinement. The results have implications to understand the altering of the free energy landscape of proteins in the confined living cell environment.

Geological inference of channel and polka-dot seismic anomalies in Yeongil bay, Pohang

The Engineering Ocean Seismic 3D system, which enables ultra-high-resolution seismic surveys on a smaller survey scale, was deployed in Yeongil Bay, Pohang, South Korea. The region is renowned for abundant shallow gas deposits and faults. Based on acoustic impedance contrast and abnormal behavior observations, two seismic anomalies termed channel and polka-dot anomalies have been identified in the seismic volume. Seismic attribute analysis based on the signal amplitude and structural characteristics reveals that these anomalies correspond to shallow biogenic gas deposits. Structural interpretation of the seismic volume revealed that the contractional deformation resulting from post-Miocene neotectonics has resulted in uplift and reverse faulting in the Pohang region, contributing to the formation of anomalies. The channel anomalies correspond to gas-saturated tidal channels that formed during eustatic sea-level changes in the post-Last Glacial Maximum period. The polka-dot anomalies are located in topographic lows and are overlain by neotectonic sediment. The different behaviors of these anomalies in a seismic volume can be attributed to the different thicknesses of overburden overlying each of the anomalies.

USING CCA-MRI TO PREDICT RESPONSE TO STEREOTACTIC RADIOSURGERY IN PATIENTS WITH BRAIN METASTASES

Abstract AIMS Brain metastases (BMs) from different primary cancers may have different radiosensitivity, for example melanoma and renal cell cancers are considered more radioresistant. Radiosensitivity is determined by the intrinsic radiobiological properties of tumours, which include vascularisation and oxygenation. Contrast Clearance Analysis (CCA)-MRI measures delayed contrast behaviour to offer a window into tumour vascularity. The CCA colour map shows areas of contrast accumulation (red), suggesting vascular damage, and rapid contrast clearance (blue), suggesting intact and increased vasculature. We aim to interrogate CCA-MRIs pre-stereotactic radiosurgery (SRS) for differences in contrast handling between BMs from different primaries. METHOD 10 patients, with 70 BMs, were included in the study. All had CCA-MRIs pre-SRS as part of their planning-MRIs. Radiotherapy-planning-CT scans were fused with the planning-post-contrast-T1-MRI, with consultant clinical oncologist-approved contoured targets, and the CCA-images. Threshold analysis was performed to obtain proportions of red and blue within the enhancing areas of each tumour. RESULTS There was a significant difference in the proportion of blue between BMs from different primaries (p=0.0294). In pairwise-comparisons, only the difference between lung and renal was significant (mean difference 37.65%, p=0.0390). The difference between the proportion of red was also significant overall (p=0.0084) (Figure 2). In pairwise comparisons, renal was significantly different from lung, breast and melanoma (mean difference 12.65%, p=0.0161; mean difference 12.97%, p=0.0154; and mean difference 11.29%, p=0.0169, respectively). CONCLUSION This study offers a novel insight into the vascularity of BMs from different primaries. Further research to explore if these findings can explain differential SRS outcomes is underway.

Contrasting conformational behaviors of molecules XXXI and XXXII in the seventh blind test of crystal structure prediction.

Accurate modeling of conformational energies is key to the crystal structure prediction of conformational polymorphs. Focusing on molecules XXXI and XXXII from the seventh blind test of crystal structure prediction, this study employs various electronic structure methods up to the level of domain-local pair natural orbital coupled cluster singles and doubles with perturbative triples [DLPNO-CCSD(T1)] to benchmark the conformational energies and to assess their impact on the crystal energy landscapes. Molecule XXXI proves to be a relatively straightforward case, with the conformational energies from generalized gradient approximation (GGA) functional B86bPBE-XDM changing only modestly when using more advanced density functionals such as PBE0-D4, ωB97M-V, and revDSD-PBEP86-D4, dispersion-corrected second-order Møller-Plesset perturbation theory (SCS-MP2D), or DLPNO-CCSD(T1). In contrast, the conformational energies of molecule XXXII prove difficult to determine reliably, and variations in the computed conformational energies appreciably impact the crystal energy landscape. Even high-level methods such as revDSD-PBEP86-D4 and SCS-MP2D exhibit significant disagreements with the DLPNO-CCSD(T1) benchmarks for molecule XXXII, highlighting the difficulty of predicting conformational energies for complex, drug-like molecules. The best-converged predicted crystal energy landscape obtained here for molecule XXXII disagrees significantly with what has been inferred about the solid-form landscape experimentally. The identified limitations of the calculations are probably insufficient to account for the discrepancies between theory and experiment on molecule XXXII, and further investigation of the experimental solid-form landscape would be valuable. Finally, assessment of several semi-empirical methods finds r2SCAN-3c to be the most promising, with conformational energy accuracy intermediate between the GGA and hybrid functionals and a low computational cost.

The effects of different strengthening treatments on wear performance of ZL109 aluminum alloy at high temperature

Enhancing strength or hardness is a widely employed strategy to improve wear resistance of ZL109 aluminum alloy at elevated temperatures. This study aimed to investigate the effects of various strengthening treatments on the wear performance of ZL109 aluminum alloy. Three strengthening methods, namely structural refinement, strain hardening, and precipitation strengthening, were employed to achieve a similar hardness level. Subsequently, the wear tests were conducted using a reciprocating ball-on-disk tribometer under different temperature conditions. The results showed that all the strengthening samples exhibited a similar wear rate (approximately 7.0 × 10−4 mm3/N·m) at room temperature. However, at 250 °C, the precipitation strengthening sample performed best with a wear rate of 1.32 × 10−3 mm3/N·m, followed by the strain hardening and structural refinement samples (approximately 1.7 × 10−3 mm3/N·m). This superior performance was attributed to the precipitation phase, which could effectively maintain material strength through dislocation pinning. By contrast, dynamic recovery and recrystallization behavior weakened the effectiveness of strain hardening, while crystal growth diminished the efficacy of structural refinement. In addition, the wear mechanisms transitioned from abrasion to adhesion and slight oxidative wear as the temperature increased.

STUDY ON THE INFLUENCE OF 1 AND 15μm PITCH VALUES ON THE APPARENT NANOMECHANICAL PROPERTIES OF LASER POWDER BED FUSION-PRODUCED CuCrZr ALLOY

Material deformation due to nanoindentation is well known. However, the deformation of a material, indentation cavity, and piled-up region drastically increases and nanohardness significantly decreases if the nanoindentation is performed in such a way that the deformation of one nanoindentation affects the others. This situation arises in various materials when they are subjected to tribological application such as pantograph assembly in electric trains and contact between the electrical power supply plug and pins. This situation has been addressed in this study and the quantitative reduction in nanohardness has been evaluated in detail. In this work, the nanoindentation was performed on the laser powder bed fusion (LPBF) CuCrZr alloy specimen under a load condition of 4500[Formula: see text][Formula: see text]N. This test was conducted at 100 points with an array of [Formula: see text] at a 1[Formula: see text][Formula: see text]m pitch value. Two significant findings were identified in this work. First, the indentation impression was smaller and the corresponding nanohardness and contact stiffness values were higher in the first column of 10 nanoindentations and the first row of 10 nanoindentations. The remaining 80 nanoindentations displayed contrasting behavior compared to the initial 20 nanoindentations due to the prior deformation of nearer regions. Nanohardness value decreased parabolically from the low deformation to the high deformation region. This finding was validated by increasing the pitch to 15[Formula: see text][Formula: see text]m under the 4500[Formula: see text][Formula: see text]N load conditions. The piled-up region around the impression of indentation changed from a semi-circular shape at a 15[Formula: see text][Formula: see text]m pitch value to a cone shape at a 1[Formula: see text][Formula: see text]m pitch value. These findings will be beneficial for industries during the design of materials and will help reduce material failures resulting from tribological activities.

Seizure outcome in surgically treated pediatric gangliogliomas and dysembryoplastic neuroepitheliomas according to imaging and resection strategies

PurposeImaging and resection strategies for pediatric gangliogliomas (GG) and dysembryoplastic neuroepitheliomas (DNET) presenting with epilepsy were retrospectively analyzed in a consecutive institutional series of surgically treated patients. MethodsTwenty-two children (median 8 years, 3–18 years) presented with seizures for 30 months median (14–55.2 months) due to a histologically verified GG/DNET. ResultsThere were 20 GG and 2 DNT, 68 % located temporal, 32 % extra-temporal. Seizure history was significantly longer in temporal cases (38 versus 14 months median, p < 0.01). MRI contrast enhancement was present in 50 % and methionine (MET) positron emission tomography (PET) uptake in 70 % (standard uptake values (SUVs) 2.92 mean, from 1.6 to 6.4). 27 % had glucose PET hypometabolism. Primarily, in temporal GG, ECoG (electrocorticography) -guided lesionectomies were performed in 87 % and antero-mesial temporal lobe resections (AMTLR) in 13 %, whereas in extra-temporal GG/DNETs, lesionectomies were performed in 100 %. ILAE Class 1 seizure outcome was primarily achieved in 73 % of the temporal cases, and was increased to 93 % by performing six repeat surgeries using AMTLR. Extratemporal patients experienced ILAE Class 1 seizure outcomes in 86 % without additional surgeries, although harboring significantly more residual tumor (p < 0.005, mean follow-up 28 months). ConclusionIn children, MET PET imaging for suspected GG is proposed preoperatively showing a high diagnostic sensitivity and an option to delineate the lesions for navigated resection, whereas MRI contrast behavior was of no differential diagnostic use. As a surgical strategy we propose primarily lesionectomies for extratemporal but AMTLR for temporal GG respecting eloquent brain areas.

How future work self salience shapes the effects of interacting with artificial intelligence

The rapid rise of artificial intelligence (AI) is transforming the world of work, leaving individuals wondering what AI means for the future of their career. The current research investigates the moderating role of future work self salience (FWSS) on the effect of interacting with AI on perceived control over one's future work self and proactive career behavior. In a first longitudinal experiment with full-time employees in the UK (N = 174), participants interacting with AI to solve a task (compared to a control group) experienced increased perceived control over their future work self when FWSS was high, in contrast to those with low FWSS. We replicated this pattern in a second longitudinal study with German business students (N = 208). Building on these findings, a third longitudinal experiment with German full-time employees (N = 155) extended the model by demonstrating a moderated mediation: for individuals with high FWSS, AI interaction increased perceived control over the future work self and thus promoted proactive career behavior. In contrast, perceived control and proactive career behavior decreased for those with low FWSS. This research demonstrates the potential impact of AI interactions on work-related outcomes, offering critical insights for both theory and practice.

The ant and the grasshopper: Contrasting responses and behaviors to water stress of riparian trees along a hydroclimatic gradient

Riparian trees are particularly vulnerable to drought because they are highly dependent on water availability for their survival. However, the response of riparian tree species to water stress varies depending on regional hydroclimatic conditions, making them unevenly vulnerable to changing drought patterns. Understanding this spatial variability in stress responses requires a comprehensive assessment of water stress across broader spatial and temporal scales. Yet, the precise ecophysiological mechanisms underlying these responses remain poorly linked to remotely sensed indices. To address this gap, the implementation of remote sensing methods coupled with in situ validation is essential to obtain consistent results across diverse spatial and temporal contexts. We conducted a multi-tool analysis combining multispectral and thermal remote sensing indices with in situ ecophysiological measurements at different temporal scales to analyze the responses of white poplar (Populus alba) to seasonal changes in drought along a hydroclimatic gradient.Using this approach, we demonstrate that white poplars along the Rhône River (France) exhibit contrasting responses and behaviors during drought depending on the latitudinal context. White poplars in a Mediterranean climate show rapid stomatal closure to reduce water loss and maintain high minimum water potential levels, although this results in a decrease in remotely sensed greenness. Conversely, white poplars located upstream in a temperate climate show high transpiration and stable greenness but lower minimum water potential and water content. A site in the middle of the gradient has intermediate responses. These results demonstrate that white poplars along a climate gradient can have a range of responses to drought along the iso/anisohydricity continuum.These results are important for future climatic conditions because they show that the same species can have different mechanisms of drought resilience, even in the same river valley. This raises questions regarding how these riparian tree populations will respond to future climatic and hydrological conditions.

3D printing hybrid-fiber reinforced engineered cementitious composites (3DP-HECC): Feasibility in long-open-time applications

Hybridization of multi-scale and multi-functional fibers to generate Hybrid-fiber Engineered Cementitious Composites (HECC) offers a promising approach for enhancing ECC in 3D printing (3DP), addressing limitations such as restricted build-up height and operation time. This study strategically combined polyethylene (PE) fiber (1.0 %), steel fiber (0.5 %) and cellulose filaments (CF) at various dosages (0–0.25 %) to investigate the evolution of rheological behavior over different time intervals (0–60 min with 15 min intervals) and optimize the printability of 3DP-HECC with long-open-time. Incorporating of CF or steel fiber enhanced static yield stress, dynamic yield stress and plastic viscosity, particularly benefiting buildability with steel fiber inclusion. Moreover, CF integration effectively moderated the growth rates of static yield stress and dynamic yield stress while maintaining thixotropic index, mitigating extrusion defects and extending operation time to 60 min for structure-level printing. Conversely, steel fiber exhibited contrasting behavior. By integrating the evolution of time-dependent rheological parameters and practical printing observations, an optimum CF dosage of 0.20 % was identified for high-quality 3DP with superior build-up layers. Finally, a fiber hybridization strategy was suggested to optimize the printability of 3DP-HECC, providing theoretical guidance for implementing high-quality applications with extended operation time.

Unveiling the Architectural Impact on the Salt-Tunable Adhesion Performance and Toughness of Polyzwitterions.

Developing tough adhesives with superior strength and ductility is challenging yet highly sought-after. In this work, we address a strategic approach to achieving diverse toughness and performance by meticulously harnessing weak electrostatic interactions. Two polyzwitterions (PZIs), derived from sulfobetaine methacrylate (SBMA), of different topologies: bottlebrush (BB-PSBMA) and linear (L-PSBMA), were designed. BB-PSBMA was synthesized using a rational "grafting-from" strategy, while L-PSBMA was prepared via atom transfer radical polymerization. Despite their architectural disparities, both PZIs demonstrated a comparable substantial lap-shear adhesion strength of ∼0.4 MPa. Intriguingly, the introduction of NaCl during adhesive preparation revealed contrasting adhesion behaviors. BB-PSBMA transitioned from a strong-brittle to strong-ductile adhesive upon the addition of 70 mM NaCl, evidenced by a 77.4% increase in the work of debonding, i.e., toughness. Further increases in NaCl concentration continued to impart the ductile properties to BB-PSBMA. Conversely, L-PSBMA adhesive predominantly transformed from strong-brittle to ductile regardless of the salt content. We propose a synergistic mechanism involving viscosity-governed optimal adhesion-cohesion balance and mechanical energy dissipation through sacrificial electrostatic association to elucidate the strong and ductile nature of the BB-PSBMA adhesive at 70 mM NaCl. Our findings emphasize the significance of precise control over architecture and salt concentration is necessary in constructing adhesives with enhanced toughness and performance.

Rational Design of Organic Emitters with Inverted Singlet-Triplet Gaps for Enhanced Exciton Management.

In organic light-emitting diodes (OLEDs), the pursuit of efficient molecular emitters has led to the development of thermally activated delayed fluorescence (TADF) molecules. While TADF compounds have promising properties, they face challenges such as energy gap constraints and uphill exciton transfer. Inverted emitters (INVEST) offer a novel solution with an inverted singlet-triplet energy (ΔEST) gap, enabling efficient utilization of excitons. This study examines the design and computational analysis of an array of molecules, including 23 INVEST emitters and remaining with positive energy gaps. Within the STEOM-DLPNO-CCSD framework, we explore the role of various molecular fragments in determining ΔEST. We also assess the importance of dynamic spin-polarization (DSP) obtained via the Pariser-Parr-Pople (PPP) scheme in energy gap determination. Exciting trends emerged from our results, with pentalene-containing compounds consistently manifesting negative ΔEST values while their naphthalene counterparts exhibited contrasting behavior. Moreover, we observed a negative DSP correlates with inverted singlet-triplet gaps. Overall, this research advances OLED materials through molecular design and computational analysis, offering avenues for optimizing exciton management and enhancing device performance.

Integration of transcriptional responses in cold contrasting sorghum genotypes under low temperatures

AbstractSorghum is a crop that is susceptible to low temperatures. However, due to the extreme global temperatures, new genotypes have been bred to adapt better to cold climates. Therefore, to better understand the metabolic and molecular differences that may contribute to the improved cold tolerance of these genotypes, it is essential to investigate whether specific molecules play a key role in determining the degree of sorghum tolerance. Furthermore, identifying genes associated with cold tolerance may assist in the development of more robust and productive sorghum cultivars. Here, we analysed the changes in selected elements of the antioxidant metabolism, genes, and miRNAs in two sorghum varieties with different degrees of tolerance to cold stress at different times of exposure to cold stress. The high expression of SbCBF6 in response to cold treatment in early time in the tolerant variety suggests its involvement in the cold response, thereby facilitating a better adaptation of the plant to cold conditions. MiR398 and miR394 showed contrasting behaviour in both varieties in low temperatures, resulting in interesting miRNAs in the degree of sorghum tolerance. MiR319, a marker for the selection of cold‐tolerant cultivars, presents a decrease, suggesting that the better capacity to repress the expression of several members of TCP family of transcription factor genes might be involved in better tolerance to cold stress. This study shows the changes of molecules of interest in response to cold stress in sorghum, marking the difference between cold‐susceptible and cold‐tolerant sorghum plants, which can contribute to selecting tolerant genotypes, allowing new strategies to enhance crop productivity and food security, in regions where low temperatures significantly constrain crop growth and yield.

Dynamics of glassy state in MAPbBr3-xClx mixed lead halide perovskites

Mixed lead halide perovskites have shown remarkable performance in photovoltaic and optoelectronic applications. Pure hybrid halide perovskites undergo clear phase transitions, however, the phase transitions in mixed perovskites are less studied. We present a contrasting behavior of the phase transition dynamics of MAPbBr3-xClx (MA = CH3NH3+) mixed halide perovskites compared to the pure MAPbX3 (X = Cl, Br) counterparts, which typically exhibit order-disorder phase transitions through a series of distinct structural phases. We have employed several spectroscopic techniques including temperature-dependent PXRD, Raman, dielectric and Brillouin spectroscopy. The results demonstrate that the mixed halide perovskite MAPbBr1.5Cl1.5 does not undergo any structural phase transition typically observed in pure halide perovskites. We observed signatures of glassy behavior in mixed compositions of this system. In addition, we also explored the effects of replacing A-site cation on the phase transition behaviors. The results contribute to the understanding of phase transition mechanisms in perovskites and have implications for their stability and optoelectronic properties.

Rajput Vocabulary of Violence

The aim of this article is to reflect on certain keywords of the Rajput world shaped by the “predominantly masculine martial culture” (Kasturi 2002: 12). Those keywords are crucial to understanding the phenomenon of violence in the Rajput milieu, violence that is perpetrated irrespective of kshatriyahood and outside the battlefield. Keeping in mind that violence cannot be identified with a particular community, but certain types of aggressive acts can be associated with certain social classes or groups (Kasturi 2002: 20), this article seeks to demonstrate that terms such as vair, bāroṭiyā, dacoity, and bhomiyāvat, reveal the mechanisms of collective violence in the socio-political practice of the Rajputs. This will be useful in understanding the cultural background of specific regional patterns of violent behaviour in contrast to the colonial stereotype of a Rajput as primitive, violent, but brave.

Exploring the underlying mechanism of interaction of Sulindac with Human hemoglobin and Lysozyme: Multi-spectroscopic, molecular docking, DFT and MD simulation approaches

Contrasting behavior of Nonsteroidal anti-inflammatory drug Sulindac (SDC) towards two different proteins Human hemoglobin (HHb) and Lysozyme (LYS) has been explored by multispectroscopy, molecular docking, DFT and MD Simulation approaches. The fluorescence quenching experiments showed that SDC strongly binds with both proteins in a static manner. Alteration in the secondary structure of HHb and LYS in presence of SDC was further investigated by CD and UV–visible spectroscopy. It is observed that on addition of SDC, the % α-helix of native HHb decreases whereas it increases for LYS-SDC system substantiated the fact SDC stabilized the secondary structure of LYS and destabilized the HHb structure thus, showing the contrasting traits. Experimental results further validated by computational techniques. Molecular docking and DFT were conducted to study the binding sites, nature of interactions and HOMO-LUMO energy gap in both the systems which revealed that the binding of SDC with both proteins resulted in the considerable change in the molecular structure of the former. Additionally, we performed MD simulations to study the structural stability of Lysozyme and Hemoglobin, both unbound and bound to the Sulindac molecule. Sulindac binding showed distinct impacts on protein stability in both proteins, supported by global and essential dynamics.This study not only provides important insights into the binding of SDC with HHb and LYS but also it provides a useful direction in the pharmacology and clinical medicine fields.

Cholesterol vs Ergosterol: Influence on the Dynamic and Structural Properties of the Cobalt-Based Metallosomal Bilayer Membrane.

Sterol derivatives are a crucial part of liposomes, as their concentration and nature can induce significant alternations in their characteristic features. For natural liposomal-based (phospholipid-based) studies, the bulk literature is already present depicting the role of the concentration or nature of different sterol derivatives in modulation of membrane properties. However, the studies aiming at evaluating the effect of sterol derivatives on synthetic liposomal assemblies are limited to cholesterol (Chl), and a comparative effect with other sterol derivatives, such as ergosterol (Erg), has never been studied. To fill this research gap, through this work, we intend to provide insights into the concentration-dependent effect of two sterol derivatives (Chl and Erg) on a synthetic liposomal assembly (i.e., metallosomes) prepared via thin film hydration route using a double-tailed metallosurfactant fabricated by modifying cetylpyridinium chloride with cobalt (Co) (i.e., Co:CPC II). The morphological evaluations with cryogenic-transmission electron microscopy (cryo-TEM), atomic force microscopy (AFM), and field emission-scanning electron microscopy (FE-SEM) indicated that metallosomes retained their spherical morphology irrespective of the nature and concentration of sterol derivatives. However, the size, ζ-potential, and lamellar width values were significantly modified with the incorporation of sterol derivatives in a concentration-dependent manner. In-depth studies affirmed that the extent of modulation of the bilayer in terms of hydrophobicity, fluidity, and rigidity was more severe with Chl than Erg. Such differences in the membrane properties lead to their contrasting behavior in the delivery of the broad-spectrum active compound "curcumin". From entrapment to in vitro behavior, the metallosomes demonstrated dissimilar behavior as even though Erg-modified metallosomes (at higher concentrations of Erg) exhibited low entrapment efficiency, they still could easily release >80% of the entrapped drug. In vitro studies conducted with Staphylococcus aureus bacterial cultures further revealed an interesting pattern of activity as the incorporation of Chl reduced the toxicity of the self-assembly, whereas their Erg-modified counterparts yielded slightly augmented toxicity toward these bacterial cells. Furthermore, Chl- and Erg-modified assemblies also exhibited contrasting behavior in their interaction studies with bacterial DNA.

Contrasting nidification behaviors facilitate diversification and colonization of the Music frogs under a changing paleoclimate

In order to cope with the complexity and variability of the terrestrial environment, amphibians have developed a wide range of reproductive and parental behaviors. Nest building occurs in some anuran species as parental care. Species of the Music frog genus Nidirana are known for their unique courtship behavior and mud nesting in several congeners. However, the evolution of these frogs and their nidification behavior has yet to be studied. With phylogenomic and phylogeographic analyses based on a wide sampling of the genus, we find that Nidirana originated from central-southwestern China and the nidification behavior initially evolved at ca 19.3 Ma but subsequently lost in several descendants. Further population genomic analyses suggest that the nidification species have an older diversification and colonization history, while N. adenopleura complex congeners that do not exhibit nidification behavior have experienced a recent rapid radiation. The presence and loss of the nidification behavior in the Music frogs may be associated with paleoclimatic factors such as temperature and precipitation. This study highlights the nidification behavior as a key evolutionary innovation that has contributed to the diversification of an amphibian group under past climate changes.

Contrasting irradiation behavior of dual phases in Ti-6Al-4V alloy at low-temperature due to ω-phase precursors in β-phase matrix

Aiming to simulate the radiation damage effect on a dual α+β phase Ti-6Al-4V alloy utilized as high-intensity accelerator beam window material, a series of irradiation experiments were conducted with a 2.8 MeV-Fe2+ ion beam in several dpa regions at room temperature. The nano-indentation hardness increased steeply at 1 dpa and unchanged up to 10 dpa, due to the saturation of defect clusters and tangled dislocations in the dominant α-phase matrix with a size of 2–3 nm and a density of about 1×1023 m−3. In contrast in the intergranular β-phase, larger loops of 20–30 nm diameter were observed with much less density of about 5×1020 m−3. The diffraction pattern showed rectilinear diffuse streaks between the β-phase reflections, corresponding to the ω-phase precursor, without dose dependency in its intensity. FFT/I-FFT analysis of the HREM revealed a sub-nanometer-sized lattice disorder with local fluctuations, not discrete but continuous, and homogeneously distributed within the matrix β-phase stably against the irradiation. The significantly low dislocation density and the absence of phase transformation in the β-phase matrix could be attributed either to the strong sink effect expected for this distinctive sub-nanometer-sized homogeneous lattice disorder or to the anomalous point defect recombination induced by the high mobility of vacancies, both of which are originated from the metastable ω-phase precursors specifically formed in the β(BCC) phase of group-4 transition metals.