Bigger Difference Research Articles

Physical and Hardness Performance at Different Surfaces for Titanium Alloy (Ti6Al4V) Printed Using Selective Laser Melting Process (SLM)

elective laser melting (SLM) 3D product is capable of producing varied surfaces such as top, core and bottom surface depending on the product dimensions and building orientation. Each surface may have differences in physical and mechanical properties such as surface roughness, microhardness, and microstructure. Therefore, this study examined the effects of SLM processing parameters as well as volumetric energy density (VED) on surface roughness, microhardness and microstructure on different 3D product surfaces. In this study, a sample of titanium alloy cube (Ti6Al4V) with different surfaces of up skin 1 (US1), up skin 2 (US2), core skin (CS) and down skin (DS) are printed on a 30° building orientation printed through the SLM process. There are nine sets of parameters printed based on the Taguchi 𝐿9 experimental design method. All printed cube samples were heat treated to remove the residual stresses generated during the printing process. The effect of processing parameters on micro hardness as well as microstructure on each surface has been studied. This study found that SLM printed Ti6Al4V produced almost identical surface quality for different surfaces of the cubic samples. Surface roughness of US2 ranging between 15.38 µm and 26.22 µm, while DS is slightly rougher with surface roughness in the range of 16.05 µm and 27.64 µm. Microhardness in the nine processing sets however was found to have a bigger difference in values of 387 ± 10 HV (US2) and 362 ± 10 HV (DS). In general, US2 surfaces were found to have high microhardness compared to the DS surfaces due to the formation of long, straight needle-like martensitic microstructure.

D&C has the best concordance between preoperative and postoperative grades among morbidly obese endometrial cancer patients.

Endometrial cancer is diagnosed by obtaining uterine biopsies by pipelle, dilatation and curettage (D&C), or hysteroscopy. In 15%-25% of the cases, the preoperative and postoperative grades do not match. This discrepancy may carry significant clinical and prognostic consequences. We aimed to assess how body mass index (BMI) affects preoperative and postoperative grade mismatches and whether biopsy methods mitigate this effect. We conducted a retrospective review of patients with endometrial cancer who underwent surgery at our center between 2014 and 2022. We stratified patients into six classes of BMI based on the WHO classification. Preoperative and postoperative grades were compared for concordance with regards to patient BMI and sampling method. A total of 158 patients were included, diagnosed by pipelle (n = 99), hysteroscopy (n = 15), or D&C (n = 44). For all methods, every unit increase in BMI increased the odds of having a gap between histology grades by 5.2%. In the pipelle group, the odds of a larger gap between the histology grades was 62% higher than that of women in the other groups. Among the D&C group, the odds of having a bigger difference between histology grades were 91.8% lower compared to the other groups. Patients with BMI over 30 had nearly 50% discrepancy when diagnosed with pipelle or hysteroscopy, but less than 10% with D&C. Increasing BMI is associated with decreasing concordance between preoperative and postoperative grades in endometrial cancer, especially when it exceeds 30. This effect is much less pronounced, however, when the diagnostic method is D&C.

First-principle exploration for RE solid-solution influence on Ni mechanical properties

Rare earth element (abbreviated as RE) doped nickel alloy is very attracted for the neutron shielding application for excellent neutron absorption and good mechanical behavior. RE solid-solution influence on Ni alloy mechanical properties has been comprehensively investigated by first-principles calculations in this work. The elastic constant and generalized stacking fault energy analysis indicate that RE substitutional solution would decrease the mechanical strength (For example, bulk modulus: BNi = 198.9 GPa, BNi31RE = 174.7 ∼ 189.8 GPa, Young's modulus: ENi = 242 GPa, ENi31RE = 183.1 ∼ 226.1 GPa and shear modulus: GNi = 93.25 GPa, GNi31RE = 69.05 ∼ 86.88 GPa) while increase the plastic deformation (intrinsic stacking fault energy: γis,Ni52 = 137.1 mJ/m2, γis,Ni51RE = 57.69 ∼ 94.17 mJ/m2 and critical intrinsic stress: τcrit,Ni52 = 31.08, τcrit,Ni51RE = 13.89 ∼ 20.00). Furthermore, the influence has a correlation with atomic radii difference Δr/rNi (the bigger difference is, the greater influence is), which is due to that hybridization strength and bonding strength decreases as Δr/rNi increases. The work provide a theoretical guidance for RE doped nickel alloys plastic deformation promotion.

Water-soluble organic carbon (WSOC) from vegetation fire and its differences from WSOC in natural media: Spectral comparison and self-organizing maps (SOM) classification

Vegetation fire frequently occurs globally and produces two types of water-soluble organic carbon (WSOC) including black carbon WSOC (BC-WSOC) and smoke-WSOC, they will eventually enter the surface environment (soil and water) and participate in the eco-environmental processes on the earth surface. Exploring the unique features of BC-WSOC and smoke-WSOC is critical and fundamental for understanding their eco-environmental effects. Presently, their differences from the natural WSOC of soil and water remain unknown. This study produced various BC-WSOC and smoke-WSOC by simulating vegetation fire and used UV–vis, fluorescent EEM-PARAFAC, and fluorescent EEM-SOM to analyze their different features from natural WSOC of soil and water. The results showed that the maximum yield of smoke-WSOC reached about 6600 folds that of BC-WSOC after a vegetation fire event. The increasing burning temperature decreased the yield, molecular weight, polarity, and protein-like matters abundance of BC-WSOC and increased the aromaticity of BC-WSOC, but presented a negligible effect on the features of smoke-WSOC. Furthermore, compared with natural WSOC, BC-WSOC had a greater aromaticity, smaller molecular weight, and more humic-like matters, while smoke-WSOC had a lower aromaticity, smaller molecular size, higher polarity, and more protein-like matters. EEM-SOM analysis indicated that the ratio between the fluorescence intensity at Ex/Em: 275 nm/320 nm and the sum fluorescence intensity at Ex/Em: 275 nm/412 nm and Ex/Em: 310 nm/420 nm could effectively differentiate WSOC of different sources, following the order of smoke-WSOC (0.64–11.38) > water-WSOC and soil-WSOC (0.06–0.76) > BC-WSOC (0.0016–0.04). Hence, BC-WSOC and smoke-WSOC possibly directly alter the quantity, properties, and organic compositions of WSOC in soil and water. Owing to smoke-WSOC having far greater yield and bigger difference from natural WSOC than BC-WSOC, the eco-environmental effect of smoke-WSOC deposition should be given more attention after a vegetation fire.

Theoretical predictions of the structural stability and property contrast for Sb-rich Ge3Sb6Te5 phase-change materials

Improving the structural stability and property contrast of phase-change materials is important to make phase-change random access memories work in prolonged service stably. Based on the density functional theory and ab initio molecular dynamics simulations, we analyze the structural, electronic, and optical properties of Sb-rich amorphous Ge3Sb6Te5, in comparison with the traditional amorphous Ge2Sb2Te5. The results show that excess Sb concentration can promote the formation of wrong bonds, tetrahedrons, and fivefold rings, which are beneficial for the structural stability of amorphous phases. In addition, Ge3Sb6Te5 has a bigger difference in the bandgap and dielectric function between the crystalline and amorphous phases, indicating that excess Sb concentration can improve the electrical and optical property contrast between the two phases. Our calculation will provide a theoretical basis for applying Sb-rich Ge3Sb6Te5 to retain data stably in prolonged service.

The evaluation of the nutritional quality of common wild edible fungi in Yunnan Province

There are huge resource reserves of wild edible fungi richer in their varieties in Yunnan Province which is located on plateau of low latitude and possesses unique various climate environments and bigger vegetative cover ratios. Moreover, nutrients and flavor substances in the same or various species of wild edible fungi differ greatly with the influence on different components from habitats and geographic areas. So, 5 common wild edible fungi were collected from different areas in Yunnan Province, and several findings were made from this research. Above all, through the evaluation of amino acids, these 5 fungi met the criteria for ideal protein by WHO/FAO, and the nutritional value of protein was ranked as matsutake>truffle>collybia albuminosa>bolete>chanterelle. Next, after the analysis of taste activity values, the ranking of taste was bolete>collybia albuminosa>truffle>matsutake>chanterelle. Subsequently, the ranking of characters was truffle>collybia albuminosa >bolete>matsutake>chanterelle through principal component analysis. Finally, truffle could be completely divided by Fisher discrimination analysis with a bigger difference from others, main in ash, protein, sugar, and polysaccharide, meanwhile, truffle and bolete could be completely divided by orthogonal projections to latent structures discrimination analysis, main in protein, crude fiber, fat, and amino acid. So, there was a more conspicuous difference in nutrients among fungi, through which nutrients combined with multivariate statistics analysis made possible the correct differentiation of small range categories in wild edible fungi, and the correct classification of small range of them could effectively be realized.

Effects of Chemical Fertilizer Reduction Combined with Organic Fertilizer Application on Bacterial Community Structure in Rhizosphere/Non-Rhizosphere Soil of Lemon

The aim of this study was to examine the effects of different fertilization methods on the physicochemical properties and bacterial community structure of lemon rhizosphere/non-rhizosphere soil in order to provide theoretical basis for scientific and rational fertilization of orchards. A pot experiment was carried out, and six fertilization treatments were set up:control (CK), conventional fertilization (FM), organic fertilizer (P), fresh organic fertilizer (NP), 70% chemical fertilizer+30% organic fertilizer (70FP), and 50% chemical fertilizer+50% organic fertilizer (50FP). Chemical analysis, real-time fluorescence quantitative PCR, and terminal restriction fragment length polymorphism (T-RFLP) were used to study the effects of different fertilization treatments on the physicochemical properties of rhizosphere and non-rhizosphere soils, the abundance of the bacterial 16S rRNA gene, and bacterial community structure. Redundancy analysis (RDA) was used to explore the environmental factors affecting the bacterial community structure of lemon rhizosphere/non-rhizosphere soil. The results showed the following:① the pH and contents of organic matter, alkali-hydrolyzed nitrogen, available phosphorus, available potassium, and nitrate nitrogen in rhizosphere/non-rhizosphere soil were significantly increased by reducing the amount of chemical fertilizer and applying organic fertilizer (50FP and 70FP) (P<0.05). Compared with conventional fertilization (FM) and single application of organic fertilizer (P and NP), the soil available P content, available K content, and nitrate nitrogen content increased by 24.76%-97.98%, 6.87%-45.11%, and 18.42%-55.82%, respectively. ② Fertilizer reduction combined with organic fertilizer significantly increased the abundance of soil bacteria and soil respiration intensity (P<0.05), and the abundance of soil rhizosphere bacteria and soil respiration intensity under the 50FP treatment increased by 15.83%-232.98% and 8.0%-162.5% compared with that under conventional fertilization and organic fertilizer alone, respectively. The bacterial abundance of rhizosphere soil was positively correlated with the pH and contents of organic matter, total nitrogen, and total phosphorus. ③ The PCoA and RDA analysis results showed that the single organic fertilizer and organic fertilizer and chemical fertilizer de-weighting of rhizosphere bacterial community structure and not adding fertilizer had a bigger difference between processing, and the main environmental factors influencing the rhizosphere/non rhizosphere bacterial community structure were organic matter, total nitrogen, total phosphorus, total potassium, alkali solution nitrogen, nitrate nitrogen, and available potassium. Fertilizer reduction combined with organic fertilizer could significantly increase soil nutrient content, increase soil bacterial abundance, and change the bacterial community structure of rhizosphere soil, and the 50FP treatment yielded better results. Therefore, 50% Chemical fertilizer+50% organic fertilizer (50FP) was a better fertilization method to improve the physical and chemical properties of orchard soil, increase the abundance of soil bacteria, and improve the soil respiration intensity.

Bipartite Ranking Fairness Through a Model Agnostic Ordering Adjustment.

Recently, with the applications of algorithms in various risky scenarios, algorithmic fairness has been a serious concern and received lots of interest in machine learning community. In this article, we focus on the bipartite ranking scenario, where the instances come from either the positive or negative class and the goal is to learn a ranking function that ranks positive instances higher than negative ones. We are interested in whether the learned ranking function can cause systematic disparity across different protected groups defined by sensitive attributes. While there could be a trade-off between fairness and performance, we propose a model agnostic post-processing framework xOrder for achieving fairness in bipartite ranking and maintaining the algorithm classification performance. In particular, we optimize a weighted sum of the utility as identifying an optimal warping path across different protected groups and solve it through a dynamic programming process. xOrder is compatible with various classification models and ranking fairness metrics, including supervised and unsupervised fairness metrics. In addition to binary groups, xOrder can be applied to multiple protected groups. We evaluate our proposed algorithm on four benchmark data sets and two real-world patient electronic health record repositories. xOrder consistently achieves a better balance between the algorithm utility and ranking fairness on a variety of datasets with different metrics. From the visualization of the calibrated ranking scores, xOrder mitigates the score distribution shifts of different groups compared with baselines. Moreover, additional analytical results verify that xOrder achieves a robust performance when faced with fewer samples and a bigger difference between training and testing ranking score distributions.

Influence of Neutron Irradiation on Microstructure and Mechanical Properties of Coarse- and Ultrafine-Grained Titanium Grade 2

The influence of neutron irradiation on the microstructure and related mechanical properties of Ti Grade 2 in coarse- and ultrafine-grained conditions was investigated. It was found that mechanical properties of the coarse-grained (CG) state were significantly affected by neutron irradiation. At room temperature (RT), the yield stress increased by more than 30%, whereas the ductility decreased by more than 50%. An even bigger difference in the mechanical properties between irradiated and non-irradiated states was observed at a temperature of 300 °C. Changes in the mechanical properties can be attributed to the high density of defect clusters/dislocation loops induced by neutron irradiation. On the other hand, the ultrafine-grained (UFG) state is more resistant to radiation damage. The mechanical properties at RT did not change upon neutron radiation, while at a temperature of 300 °C, the yield stress increased only by about 10%. Enhanced radiation resistance of the UFG state can be attributed to the presence of a high density of dislocations and dense network of high-angle grain boundaries, which act as traps for radiation-induced defects and, thus, prevent the accumulation of these defects in the microstructure.

Cluster spacing optimization of deep shale gas fracturing with non-uniform geostress

Cluster spacing optimization in non-uniform stress field, with the optimal stimulated reservoir volume (SRV) as target, which is critical for deep shale gas fracturing performance. A non-uniform stress field characterization model and a fracture network propagation model were constructed. The diagrams of the optimal cluster spacing were drawn based on the fault development in the Y1-01 well area. The results showed that the horizontal well should be deployed at a distance of between 2,000 and 4,000 m from the first-level fault, 1,500 and 2,500 m from the second-level fault, 700 and 1,200 m from the third-level fault, and an acceptable distance from the fourth-level fault. The shorter the distance to the fault for first-level faults, the bigger difference in horizontal stress, which was not conducive for fracture network propagation, and the smaller the optimal cluster spacing. For second-level, third-level, and fourth-level faults, when the fault strike was less than 50°, the closer to the fault, the bigger the difference in horizontal stress and the smaller the optimal cluster spacing. When the fault strike was greater than 50°, the farther away from the fault, the bigger the difference in horizontal stress, and the smaller the optimal cluster spacing.

Computing the Wide-Band Earth Return Impedance of Submarine Cable Considering Complex Paths

Because of the various earth return pathways in practical projects, calculating the wide-band earth return impedance of submarine cable is problematic. Using the dynamic Hertz magnetic potential, the formula for estimating the earth return impedance has been obtained based on the three-layer structure of air, sea water, and seafloor. Furthermore, in the frequency range of 50 [Formula: see text] 10 MHz, the enhanced complex image approach and numerical integration method have been developed to compute the earth return impedance. The suggested iterative complex image method outperforms the classic complex image method in terms of accuracy and computation speed, with a global fitting error of less than 10−6. Finally, the impact of various models on the real and imaginary parts of submarine cable wide-band earth return impedance has been investigated. The results demonstrate that the actual component has a more complicated variation, whereas the imaginary part is clearly affected by the skin effect, with a bigger difference in the high-frequency range. The method presented in this research can be utilized as a supplement to existing methods, as well as a reference methodology for analyzing the influence of over-voltage on submarine cable engineering.

New methodology of dynamical material response of dissimilar FSWed Al alloy joint under high strain rate laser shock loading

This paper presents an innovative methodology of material characterization under high strain rate (order of 107s-1) laser shock loading coupled with microstructural and mechanical material features. To that scope, experimental and simulation analyses have been conducted for Al alloys (AA7075-T6 and AA2017-T4) and dissimilar Friction Stir Welded (FSWed) AA7075-AA2017 joint, under shock pressure of 4.5 GPa (laser power density of 3.5 GW/cm2). In order to perform proper in-depth material model simulation of these alloys and dissimilar pairs, Johnson–Cook (J-C) material model has been coupled with Grüneisen equation of state using the non-linear explicit code LS-DYNA. For the first time, we provided a way to differentiate between material behaviour in the cross-section and the in-plane rolling and welding direction. What is more, we have provided the link between microstructural features and mechanical properties such as microhardness, residual stresses and the identified material parameters. By achieving this goal, the bigger difference between studied planes was confirmed for strain hardening modulus, strain hardening exponent and strain rate sensitivity parameters. Obtained results and proposed methodology indicate high potential to predict material properties and behaviour of dynamically stressed parts and at the same time can be used for optimization of LSP process.

Cultural Difference or Similarity, Selection of Targets and Post- Acquisition Performance

This paper examines how difference as well as similarity in Individualism-Collectiveness cultural background between the acquirer and target affects the acquirer’s post-acquisition performance during internationalization. Besides examining how distance in individualism will affect acquirer’s post-acquisition performance, two groups will be compared to find out whether the heterogenous types of similarity in Individualism-Collectiveness will affect the post-acquisition performance differently. The first study of the analysis of 681 cross- border deals reveals that a bigger difference in individualism is indeed negatively associated with post-acquisition performance; and this negative association will be tampered if there is a national status difference between the acquirer and the target. The second study of the analysis of 867 cross-border deals tests how similarity in Individualism-Collectiveness influences acquirer's post-acquisition performance. This test further reveals that when the acquirer and the target both come from collectivistic cultures, the post-acquisition performance will be better compared to the situation where both firms come from individualistic nations. These findings enrich the current literature that has focused on the difference of cultural background of acquisition by revealing effects of different types of cultural similarity on acquisition performance, meanwhile offer interesting implications for corporate managers when search for potential acquisition targets.

Interaction between serum vitamin C levels and smoking on the periodontal condition in older adults.

Several epidemiological studies have reported that smokers have a higher prevalence and severity of periodontal disease than do nonsmokers, and that smoking negatively affects nutritional status and is associated with a reduced intake of antioxidants, particularly vitamin C. The present investigation aimed to examine the relationship between serum vitamin C levels and smoking and its influence on the periodontal condition in older adults. A total of 353 respondents met the inclusion criteria and were enrolled in the present study. The periodontal status of the study participants was determined through examinations of one or more residual teeth, which included a measurement of the probing pocket depth (PPD) and clinical attachment level (CAL) at six regions of each tooth. Blood samples were collected during the dental examinations and then sent to a laboratory to evaluate serum vitamin C and cotinine levels. A serum cotinine concentration of 100ng/ml was considered a relevant threshold for active smoking. After dividing the participants into two groups according to serum cotinine levels, Poisson regression analysis was carried out to compare vitamin C levels with the prevalence rate ratio (PRR) for periodontal condition markers for each group based on serum cotinine levels. We evaluated differences in the PRR of serum vitamin C tertiles between participants with high (≥100ng/ml) or low (<100ng/ml) serum cotinine levels after adjusting for sex, the use of interdental brushes or dental floss, and the number of teeth. A negative tendency between the PRR of vitamin C tertiles for the PPD or CAL was seen for both groups. Especially, a bigger difference was observed in the group with high serum cotinine levels. The PRR of the first tertiles in the high serum cotinine group was 5.03, compared with 2.69 in the low serum cotinine group (relative risk: 1.9). The results of this study suggest a potential association between vitamin C levels and the periodontal condition, which may be influenced by smoking status.

Experimental assessment of the behavior of expanded glass lightweight reinforced concrete walls

Structural lightweight concrete (LWC) can significantly reduce the dead loads of reinforced concrete (RC) structures and therefore the associated seismic forces. A new LWC was made using expanded glass as lightweight aggregate (LWA), which is comparatively much lighter than conventional LWAs, and might lead to different performance in lightweight RC elements. An experimental study was conducted to evaluate the structural behavior of expanded glass LWC RC walls. Two types of RC walls were built and tested under cyclic displacement protocol: slender confined and squat unconfined walls. For each type of wall, four specimens were considered: two with LWCs with fc′ of 30 and 40 MPa (i.e., L30 and L40) and densities of 1200 and 1700 kg/m3, respectively; and two with normal weight concretes (NWC) with the same specified strengths acting as control specimens (i.e., N30 and N40) and a density of about 2400 kg/m3. These walls were analyzed in terms of yield drifts and strengths, maximum drifts and strengths, ductility and energy dissipation. Results show that slender confined walls made with L30 mixture showed reductions in ductility and energy dissipation of about 56 and 34%, respectively when compared to N30 specimens. Meanwhile, L40 specimens showed the same tendency, but with smaller reductions compared to N40 of about 36% of ductility and 10% of energy dissipation. In squat unconfined walls, a significant reduction of strength was observed for both types of LWCs, although a bigger difference was observed in L30 concrete. Overall, expanded glass LWC showed promising structural behavior, especially L40 mixture, which presented relatively small differences compared to its NWC counterpart and had only 70% of its unit weight.

Carbon fiber versus glass fiber reinforcements: A novel, true comparison in thermoplastics

AbstractCarbon fiber and glass fiber are two dominating reinforcements for polymer composites. Fiber‐reinforced thermoplastics are widely used in many applications. It has a higher growth rate than thermoset composites due to ease in processing and recyclability. Glass fiber has been on the market for 80 years and carbon fiber over 50 years. There are hundreds, if not thousands, of research paper to compare the performance of the two fibers and hybrid. All the studies are from commercially available products. In all those cases, these two fibers are non‐comparable. They have different fiber diameter, size and sizing content, chop length and chopping process. Taiwan Glass Industries, Corp. has cordially provided two experimental chopped strands that match the characteristics of chopped carbon fibers. The first one is for nylon reinforcement and the second one is for polypropylene. Now the glass fiber and carbon fiber have the same fiber diameter (7 microns), same size and sizing content (1%), and same chop length (6 mm). Most importantly, they are produced in identical way (off‐line chop). The only difference between two fibers is silane on glass surface. This is the first of this kind of study. It gives a true comparison of two fibers with identical characteristics. As expected, fiber diameter has the biggest influence in mechanical properties among all fiber characteristics. For nylon, the difference between 7 micron and 10 micron glass fiber is small in tensile and flexural strength. It has bigger difference in impact strength. For polypropylene reinforcement, the fiber diameter of standard polypropylene dispersion (PP) glass fiber is 13 microns; almost double that of carbon fiber. Seven‐micron PP glass actually outperforms PP carbon fiber in composite strengths.

Distributed vacuum membrane distillation driven by direct-solar heating at ultra-low temperature

Membrane distillation (MD) process is capable of utilizing ultra-low temperature heat (<50 °C), and its compact configuration permits a small module size. Thus a distributed MD device driven by low-grade solar energy for household desalination becomes viable. In this paper, direct solar-heating schemes for vacuum MD (VMD) by photothermal membrane (VMD-PM) and by solar absorber-plate (VMD-FPC) are comparatively analyzed under identical operating conditions. Such a comparison allows for a better understanding of the performance improvement brought by the new structure (VMD-PM) as well as its mechanism. A comprehensive model considering geographical location, date & time, solar absorption, pore diffusion, and dynamic variation etc. was built for performance evaluation. Results revealed that VMD-PM system could achieve a distillate production of 7.14 L m−2, 4.1% higher than VMD-FPC in a 10-h operation with 22.8 MJ m−2 of solar energy. Considering heat recovery for both systems, an even bigger difference in production, up to 11.7% could be observed. Such performance elevation is attributed to the localized heating at membrane surface and more efficient conversion of solar energy to evaporation heat. Results also indicated that utilizing photothermal membranes can indeed relieve the issue of temperature polarization. However, such phenomenon cannot be entirely eliminated.

Absence of a bilingual cognitive flexibility advantage: A replication study in preschoolers.

Some studies have found a bilingual advantage in children’s executive function and some failed to find a bilingual advantage. For example, the results of a previous study by Bialystok & Martin (2004) indicated that Chinese-English bilingual preschool children outperformed English monolingual children in solving the dimensional change card sort (DCCS). The goal of our study was to replicate this study using the same dimensional change card sort task. We also tested our participants on vocabulary and digit span. Our participants were 40 English monolingual and 40 Mandarin-English bilingual children and were within the same age range as the children in Bialystok & Martin’s (2004) study. Our results showed no difference between bilinguals and monolinguals. Both groups of children in the present study performed better than those in Bialystok and Martin (2004), but the bigger difference was between the two groups of monolinguals. These results suggest that it could be important to attend to monolingual children’s performance, in addition to bilinguals’, when testing for a bilingual advantage. Our replication study is important because it helps with clarifying the validity of studies finding a bilingual advantage and to help future researchers know whether to build on their findings or not.

Risk assessment of shoulder dystocia via the difference between transverse abdominal and biparietal diameters: A retrospective observational cohort study.

Shoulder dystocia is defined as vaginal cephalic delivery that requires additional obstetric maneuvers to deliver the fetus after the head has been delivered and gentle traction has failed. A bigger difference between the transverse abdominal diameter (TAD) (abdominal circumference [AC]/π) and biparietal diameter (BPD) (TAD-BPD) has been reported as a risk factor for shoulder dystocia in different countries; however, it remains unclear if this relationship is relevant in Japan. This study aimed to clarify the association between TAD-BPD and shoulder dystocia after adjusting for potential confounding factors in a Japanese cohort. We retrospectively examined 1,866 Japanese women who delivered vaginally between 37+0 and 41+6 weeks of gestation at the University of Yamanashi Hospital between June 2012 and November 2018. The cutoff value of TAD-BPD associated with shoulder dystocia and the association between TAD-BPD and shoulder dystocia were evaluated. The mean maternal age was 32.5±5.3 years; the patients included 1,053 nulliparous women (57.5%), 915 male infants (49.0%), 154 women with gestational diabetes mellitus (GDM) (8.3%), and 5 infants with macrosomia (0.3%). The mean TAD-BPD was 9.03±4.7 mm. The overall incidence of shoulder dystocia was 2.4% (44/1866). The cutoff value to predict shoulder dystocia was 12.0 mm (sensitivity, 61.4%; specificity, 73.8%; likelihood ratio, 2.34; positive predictive value, 5.4%; negative predictive value, 98.8%). We then used a multivariable logistic regression analysis to examine the association between TAD-BPD and shoulder dystocia while controlling for the potential confounding factors. In multivariate analyses, TAD-BPD ≥12.0 mm (adjusted odds ratio [OR], 4.39; 95% confidence interval [CI], 2.35–8.18) and GDM (adjusted OR, 3.59; 95% CI, 1.71–7.52) were associated with shoulder dystocia. Although TAD-BPD appears to be a relevant risk factor for shoulder dystocia, sonographic fetal anthropometric measures do not appear to be useful in screening for shoulder dystocia due to a low positive predictive value.

Predicting climate effects on aquatic true bugs in a tropical biodiversity hotspot

Climate change is a matter of worldwide concern with severe predicted impacts on biodiversity. Here, we analysed the potential impacts of current and future climates on aquatic true bugs (Heteroptera) in relation to their distribution patterns and ecological preferences (based on a database generated from existing literature references and field collections). We considered the traits as ‘species thermal range’ and ‘emergence period’ to evaluate the future climate change impacts on the distributions of aquatic true bugs in the riverine regions of a tropical biodiversity hotspot, the Western Ghats of India. We used Species Distribution Models (SDMs) to evaluate the potential impacts of climate change on the distributions of aquatic true bugs. We modelled the distributions of twenty-six species of aquatic true bugs using different modelling tools through a carefully examined set of occurrence records to generate potential present distributions and to project these distributions into future scenarios of climate change. We observed increasing/decreasing range sizes of the species in the current and future scenarios. We found losses and increases of species' ranges in some regions, but not much variation in species richness. Similarly, no significant effect was observed in the distribution ranges for species with different duration of emergence period and thermal range in current and future climatic scenarios. Losses and gains in species richness would be concentrated in the mountainous area of the Western Ghats, whereas loss of species and the bigger difference between current and future richness will occur in the adjacent lowlands and towards central regions, including the network of protected areas of the Western Ghats. These areas are critical to buffer regional species loss in the future.Implications for insect conservationGiven the importance of aquatic true bugs as bioindicators and biological control agents, monitoring their range shifts should be routinely addressed in the conservation contexts of the Western Ghats.