Ar Values Research Articles

Numerical Modeling Reveals That Resistant Western Corn Rootworm Are Stronger Fliers than Their Susceptible Conspecifics

The hindwing geometry, aspect ratio, and numerical modeling of susceptible, Bt-Corn- and rotation-resistant western corn rootworm (WCR) wings was investigated. All variants had similar hindwing geometries and aspect ratio (AR: 6–7). These AR values correspond to wings suited to lower altitude flights of a shorter distance. These AR values are characteristic of wings that can carry heavier loads and are capable of precision flying. Numerical modeling using the finite element method (FEM) showed that the Bt-Corn-resistant and rotation-resistant WCR hindwings could potentially resist higher wind speeds with minimal deformations compared to conspecific susceptible WCR. Understanding the physiology and dispersal of resistant WCR enables a better understanding of how these variants spread their alleles across large scale agricultural landscapes. This may have important implications for integrated resistant management strategies for WCR.

Research of correlation between aspect ratio and descent rate-Based on paper-plane using experiment

The aspect ratio is important to airplane performance because it affects the aircrafts performance by changing the geometry of the aerofoil, which affects the lift the aerofoil can generate. An experiment of testing 5 planes with different wing aspect ratio has performed in order to figure out the relationship between aspect ratio and descent rate. The experiment is based on small scale model. Before the experiment, analysis based on physics computation show some advantage of small scale model. The wing of the model airplane is made of paper, and the fuselage is made from paperboard. The plane is released at a certain height by a rubber band which allow the plane to glide. Finally, the experiment shows that although the increase in aspect ratio can improve the performance of the plane, the performance will get worst as aspect ratio increases after a critical aspect ratio. Computation of the average descent rate and comparison in gliding distance of different wing aspect ratio obtained by the experiments show the optimal value of AR is 5.1.

The Comparative Study of Serum Estrogen and Lipid Profile in Pre- and Post-menopausal Women as Atherosclerosis Risk Factors in Pakistan.

Menopausesignifies the eternal termination of menstruation in women as a consequence of ovarian action loss, typically occurring around the age of 51 years. Cardiovascular disease is the leading cause of death among post-menopausal women, which may be due to lower levels of estrogen and lipid profile. The present study was undertaken to evaluate serum estrogen and lipid profile status to assess the risk of atherosclerosis in both pre- and post-menopausal women. The objective of this study is to explorethe relationship between estrogen and lipid levels of women in pre- and post-menopausal stages. A comparative cross-sectional study was conducted at Railway General Hospital Rawalpindi. A total of 100 participants were included of which 50 were pre-menopausal and 50 were post-menopausal women. Laboratory examination and questionnaires from the study population were used for data collection. Through the enzymatic method, serum cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein (HDL) were assessed. Serum very low-density lipoprotein (VLDL) levels were calculated via Friedwald's components VLDL=TG/5.0. An enzyme-linked immunosorbent assay kit was used for estrogen measurement. For statistical analysis, Student's t-test and the Pearson correlation test were used. Women after menopause have significantly high serum cholesterol, low-density lipoproteins, VLDLs, and triglycerides while HDL-c levels were significantly low (P<0.001). Levels of estrogen were low in post-menopausal females (P<0.001) as compared to menstruating women. Estrogen with HDL concentrations showed a positive correlation with an r value of 0.08556 while LDL levels showed a negative correlation with ar value of -0.26219. This comparative study explores the relationship between estrogen and lipid levels in pre- and post-menopausal women. Low estrogen with changed lipid variables was observed. Decreased cardiovascular protective HDL-c marks that menopause is a phase that acts as an independent risk factor for atherosclerosis.

Abstract PO4-05-14: Gene expression in metastatic breast cancer – patterns and prognostic potential

Abstract Introduction Metastatic breast cancer (mBC) is the leading cause of breast cancer mortality. However, mBC has a considerable variance in prognosis and course of disease, reflecting a substantial biological heterogeneity. Despite this, there is a lack of prognostic biomarkers validated for mBC. New prognostic markers and improved understanding of the molecular variants of mBC could aid in prognostication and personalizing treatments, and lead to the discovery of novel drug targets. The primary objective of this study was to explore the prognostic value of gene expression (GEX) in the distant metastasis (DM) of mBC. Secondly, we aimed to identify molecular subtypes of mBC, and describe their biological niches. Methods We used a cohort of mBC patients enrolled in a prospective trial (NCT01322893) that includes tissue from primary tumor (PT) and matched lymph node metastasis (LNM) and/or DM (1). The inclusion criteria were diagnosed mBC with a life expectancy of &amp;gt;2 months, ECOG score of 0-2, and an age of &amp;gt;18 years. RNA was extracted from formalin-fixed, paraffin-embedded tumor tissue. GEX data were acquired for n=123 PT, n=71 LNM, and n=74 DM using the NanoString Breast Cancer 360 assay, which comprises 758 genes and &amp;gt;30 GEX signatures. The relationships between GEX and the endpoints overall survival (OS) and progression-free survival (PFS) were assessed using cox proportional hazards regression with GEX as a continuous score. Multivariable cox regressions were adjusted for PAM50 of the DM, number of metastatic sites, visceral metastasis, ECOG, and age at mBC diagnosis. Visualization by heatmap and k-means clustering were used to identify GEX patterns. When clustering single genes, we included only the 100 genes with the highest standard deviation. Results In relation to PFS, we found prognostically unfavorable roles of DM GEX of the signatures for Treg cells (HR=1.3, p=0.02), cytotoxicity (HR=1.3, p=0.03), and p53 (HR=1.3, p=0.02). Further, our data indicate prognostically favorable value of DM GEX of ESR1 (HR=0.77, p=0.02), PGR (HR=0.65, p=0.002), FOXA1 (HR=0.76, p=0.02), and AR (HR=0.68, p=0.0006). The prognostic value of AR remained in multivariable analysis. In relation to OS the first 2 years after mBC prognosis, we found prognostically favorable value of DM GEX of B7H3 (HR=0.65, p=0.04), TGFB (HR=0.53, p=0.02) and the signatures for stroma (HR=0.7, p=0.05) and claudin-low (HR=0.61, p=0.02). Finally, our data suggests that the previously published PAM50MET panel performs well as a prognostic indicator, especially when considered on a continuous scale, for PFS (HR=1.3, p=0.0023) and OS (HR=1.3, p=0.003) (2). Based on the 100 most highly variable genes, we identified five stable tumor clusters with distinct GEX profiles, where some strongly associated with metastatic site. Using the same approach on the GEX signatures, we established four GEX profiles able to outperform PAM50 in identifying tumors with poor OS in this material. Conclusion In this study, we demonstrate prognostic value for GEX-based panels in DM samples. First, we find GEX signatures related to hormone responsiveness to be favorable, and genetic instability to be unfavorable for mBC prognosis. We also demonstrate AR to be an independent marker for better PFS. Further, we confirm the prognostic value of PAM50MET, a previously published panel with the advantage of including only PAM50 genes and clinical parameters. Finally, we identify new GEX profiles related to metastatic site and outcome. These results illuminate the biological differences between mBC in relation to outcome and metastatic site. Better understanding of the mBC GEX subtypes may open new venues for tailored treatment.

ACUTE EFFECT OF CONTINUOUS RUNNING ON WHITE BLOOD CELL (WBC) AMONG PHYSICALLY TRAINED BOYS

Introduction: In this research, the examination of the acute effect of continuous running on the white blood cell status of physically trained boys has been aimed. Methods: Ten (10) physical education male students with an average age of 23.16±1.85 years participated in this study voluntarily. The white blood cell status (WBC) of the students was analyzed before running (BR) and just after 35 minutes of continuous running (AR). To determine White blood cell status (WBC), blood samples with 5 ml EDTA were taken from the forearm ante-cubical area before and after resistance exercise, and analyzed in the laboratory using an auto-analyzer (Sysmex XP- 100). Result: Measurement results were presented as average and standard deviation. Student T-test for dependant samples was used to make a comparison between BR and AR values. P&lt;-0.01 value was considered to be significant. The result of the study revealed that, the increase in AR than BR values for White blood cell status (WBC) was significant. Conclusion: Conclusively White blood cell status (WBC) displayed significant incensement in relation to acute continuous running.

The first experience of parallel measurements of objective accommodation parameters in children with myopia using various instruments: in search of a common denominator

Purpose: to study the relationship between the parameters of reflex and tonic accommodation measured using various objective methods.Material and methods. A comprehensive parallel study of objective accommodation parameters of 57 children (114 eyes) with low and moderate myopia (average -2.6 ± 1.4 D) aged from 8 to 12 years (average 9.9 ± 1.6 years) was carried out on three devices: Grand Seiko WAM-5500K, Acomoref 2 K-model Righton; TONOREF III, Nidek.Results. Both coincidences and differences of the indicators obtained by different methods as well as their correlations were revealed: positive - between the values of AR in the open field and in the virtual space (r = 0.23, r = 0.2); between the virtual responses to Righton K-2 and Nidek (r = 0.38); direct correlations of the accommodation response with accommodation tones. A correlation of average strength (r = 0.44) was found between the HAT on the Grand Seiko WR-5100K and the CMF on the Righton K2, which allows us to consider them as synonymous indicators. A negative relationship of CMF with PRA and SE refraction was found. A positive correlation of CMF with the rate of progression of myopia and a negative one with PRA suggests that a high CMF is a bad prognostic sign. However, CMF positively correlates with the magnitude of the accommodative response on all three devices. In this case, it turns out that an increase in CMF accompanies an increase in the amplitude of accommodation and, therefore, is not always a troublesome factor. Perhaps we are dealing with the limits of the norm for this indicator, which still need to be studied.Conclusion. With the help of objective methods of studying qualitatively different characteristics of one process, it is possible to investigate the actual and prognostic parameters of accommodation, which will allow us to offer an individualized approach to the treatment of patients with myopia using optical and drug instruments.

Rainbow disjoint union of P4 and a matching in complete graphs

An edge-colored graph G is called rainbow if all the colors on its edges are distinct. Given graphs G and H, the anti-Ramsey number AR(G,H) is the maximum number k such that there exists an edge-coloring of G with exactly k colors containing no rainbow copy of H. Recently, the anti-Ramsey problem for disjoint union of graphs received much attention. In particular, several researchers focused on the problem for graphs consisting of small components. In this paper, we continue the work in this line. We refine the bound of n and determine the precise value of AR(Kn,P4∪tP2) for all n≥2t+4 in complete graphs.

A Whole W-Band Multi-Polarization Horn Antenna Based on Boifot-Type OMT.

A wideband multi-polarized square-horn antenna based on an orthogonal mode transducer (OMT) is developed for working in the whole W-band in this paper. The designed antenna is capable of radiating multiple polarization modes as horizontal polarization (HP) and vertical polarization (VP) when as single-port excitation and left-handed circular polarization (LHCP) and right-handed circular polarization (RHCP) when as dual-port excitation, owing to the characteristic of the OMT with the transmitting of orthogonally polarized waves. A CNC-layered fabrication approach is proposed, which means that the antenna prototype integrating with a Boifot-type OMT, turning waveguide, twisting waveguide and phase shifter is divided into three layers along the vertical direction to be fabricated based on computerized numerical control (CNC) technology. In the design, the turning waveguide and twisting waveguide are employed to achieve plane consistency of the antenna branch ports. Furthermore, a phase shifter is designed to compensate the orthogonally polarized waves, which can keep the phase of the orthogonally polarized waves consistent in a wideband frequency range from 75 GHz to 110 GHz. A prototype is fabricated and measured to verify the performance of the proposed multi-polarization antenna, and the measured results agree well with the simulation ones. In the whole W-band, the value of return loss is better than 10 dB of all polarization modes, and the value of AR of the LHCP and RHCP is below 3.5 dB. The maximum gain of the antenna reaches up to 18.8 dBi at 110 GHz. In addition, regarding the layered structure, the possible layered assembly error analysis is discussed, which verifies the feasibility of the layered machining for this antenna.

Simultaneous degradation of chlorpyrifos and profenofos in soils at sublethal concentrations in presence of Eisenia foetida and a native bacterial consortium

The use of organophosphates (OPPs) in agriculture is an environmental problem due to their persistence in the environment, affecting non-target species, including human beings. For this reason, this study evaluated the degradation of chlorpyrifos (CPF) and profenofos (PFF) simultaneously in soils at sublethal concentrations in the presence of Eisenia foetida (EF) and a native bacterial consortium (NBC). For this, we first studied the avoidance behavior of EF to soils contaminated with CPF and PFF by calculating the percentage avoidance response (AR%), finding that EF presents an avoidance behavior to soils contaminated with CPF (6.45 to 65.5 mg/kg) and PFF (2.26 to 112.95 mg/kg) and their mixture, giving values of AR% (+). EF did not show avoidance behavior with AR% (-) values when melon rinds were added as substrate making it feasible to study the degradation of CPF and PFF at concentrations of 65.5 mg/kg and 112.95 mg/kg. EF and NBC showed synergism in degradation, reducing the half-life time from 70 days (CPF) and 50 days (PFF) to 15 days in both cases, with degradation percentages at 28 days of 73.75% for CPF and 71.73% for PFF, with pH being the determining factor in degradation, favoring degradation at pH higher than 7. The study was scaled to real agricultural soils with concentrations of 0.801 and 0.592 mg/kg CPF and PFF, respectively. These concentrations represented an ecological risk with risk quotient values of RQ>1. After the application of EF and NBC, both OPPs were eliminated to non-detectable concentrations. It has been demonstrated that the application of EF and NBC is an effective alternative to be applied in agricultural soils contaminated with OPPs, which would reduce the negative impacts of these toxics on the environment and human beings.

FINITE ELEMENT ANALYSIS OF REINFORCED AND UNREINFORCED DEEP SOIL MIXING COLUMNS INSTALLED IN COHESIVE AND NON-COHESIVE SOILS

A parametric study employing three-dimensional finite element analysis is used in this paper to examine the improvement of soft clay and silty loose sand under a road embankment using deep soil mixing (DSM) columns. Both soils are designed with three variables namely DSM column diameter (D), DSM column length (L) and centre-to-centre distance of the DSM columns (s). The settlement values under the road embankment constructed with and without DSM columns were obtained by numerical analysis. The analyses were also repeated for the DSM columns which were stiffened by adding I-profiles. The results showed that the improvement effect of the DSM columns on settlement is higher in soft clay. For constant improvement area ratio (ar), the maximum improvement is achieved for D = 80 cm (2.62 ft.) and increasing D did not affect the degree of improvement. In both soil types, settlement decreased with increasing L within the weak soil zone. Increasing L into the comparatively stronger soil did not significantly affect the settlement value. Although the settlement decreased with increasing ar in silty loose sand, it reached at maximum in soft clay at ar of thirty-five percent and was not affected thereafter with increasing ar values.

Experimental investigation and statistical evaluation of the effects of steel fiber aspect ratio and fiber rate on static and dynamic mechanical properties of concrete

Static and dynamic mechanical properties of steel fiber concretes were determined by experiments conducted on concretes produced using fibers of different volume ratios and aspect ratios, and variance analysis was applied to the experimental results and evaluated statistically. Flexural toughness, static and dynamic elasticity modules and Poisson ratios of steel fiber reinforced concrete (SFRC) were determined experimentally. Load-deflection curves under flexural loading and stress-strain curves under compressive loading were obtained and compared with each other. The most influential variable was aspect ratio of fibers affecting each feature. As the aspect ratio increased, the static elasticity modulus of concrete increased by 29.66 %, the dynamic elasticity modulus increased by 21.58 % and the Poisson ratio increased by 27.46 % compared to the control sample. The Poisson ratio of SFRC varies between 0.1825 and 0.246. A relation was obtained between static and dynamic modulus of elasticity. Mechanical properties were improved by using steel fibers with low amounts but high AR values. To achieve high flexural toughness, static and dynamic elasticity modules and Poisson ratio, aspect ratio of fiber should be increased.

Clinical evaluation of augmented reality-based 3D navigation system for brachial plexus tumor surgery

BackgroundAugmented reality (AR), a form of 3D imaging technology, has been preliminarily applied in tumor surgery of the head and spine, both are rigid bodies. However, there is a lack of research evaluating the clinical value of AR in tumor surgery of the brachial plexus, a non-rigid body, where the anatomical position varies with patient posture.MethodsPrior to surgery in 8 patients diagnosed with brachial plexus tumors, conventional MRI scans were performed to obtain conventional 2D MRI images. The MRI data were then differentiated automatically and converted into AR-based 3D models. After point-to-point relocation and registration, the 3D models were projected onto the patient’s body using a head-mounted display for navigation. To evaluate the clinical value of AR-based 3D models compared to the conventional 2D MRI images, 2 senior hand surgeons completed questionnaires on the evaluation of anatomical structures (tumor, arteries, veins, nerves, bones, and muscles), ranging from 1 (strongly disagree) to 5 (strongly agree).ResultsSurgeons rated AR-based 3D models as superior to conventional MRI images for all anatomical structures, including tumors. Furthermore, AR-based 3D models were preferred for preoperative planning and intraoperative navigation, demonstrating their added value. The mean positional error between the 3D models and intraoperative findings was approximately 1 cm.ConclusionsThis study evaluated, for the first time, the clinical value of an AR-based 3D navigation system in preoperative planning and intraoperative navigation for brachial plexus tumor surgery. By providing more direct spatial visualization, compared with conventional 2D MRI images, this 3D navigation system significantly improved the clinical accuracy and safety of tumor surgery in non-rigid bodies.

Increasing Long-Term Memory as an Early Warning Signal for a Critical Transition

Abstract In recent years, various early warning signals of critical transition have been presented, such as autocorrelation at lag 1 [AR(1)], variance, the propagator based on detrended fluctuation analysis (DFA-propagator), and so on. Many studies have shown that the climate system has the characteristics of long-term memory (LTM). Will the LTM characteristics of the climate system change as it approaches possible critical transition points? In view of this, the present paper first studies whether the LTM of several folding (folded bifurcation) models changes consistently as they approach their critical points slowly by the rescaled range (R/S) analysis. The results of numerical experiments show that when the control parameters of the folding model are close to its critical threshold, the Hurst exponent H exhibits an almost monotonic increase (significance level α = 0.05). We compare the performance of R/S with the existing indicators, including AR(1), variance, and DFA-propagator, and find that R/S is a perfectly valid alternative. When there is no extra false noise, AR(1) and variance have good early warning effects. After the addition of extra Gaussian white noise of different intensities, the values of AR(1) and variance change significantly. As a result, the DFA-propagator based on AR(1) calibration also changed significantly. Compared with the other three indicators, the early warning effect of H has stronger ability to resist the interference of external false signals. To further verify the validity of increasing H, paleoclimate reconstruction of Cariaco Basin sediment core grayscale record with long trends filtered out is studied by R/S analysis. The other three early warning signals are calculated in the same way. The data contain a well-known abrupt climate change: the transition between the Younger Dryas (YD) and the Holocene. We find that approximately 300 years before this abrupt climate change occurred, before 11.7 kyr BP, the LTM exponents for Cariaco Basin deglacial grayscale data present an obvious increasing trend at a significant level of α = 0.05. Meanwhile, the variation trend of H and DFA-propagator is basically similar. This shows that increasing H by R/S analysis is an effective early warning signal, which indicates that a dynamic system is approaching its possible critical transition points; H is a completely valid alternative signal for AR(1) and DFA-propagator. The main conclusion of this paper is based on numerical experiments. The precise relationship between H and the stability of the underlying state approaching the transition needs to be further studied. Significance Statement Dynamic systems have critical transition points, and these systems will suddenly change from a stable state to another alternative one beyond these points. Using several simple theoretical models and paleoclimate data, we study whether the characteristics of long-term memory, which are ubiquitous in complex systems in nature and society, change as a system approaches its critical transition point. The results show that the long-term memory of a dynamic system increases significantly with the approach of the critical point, whether in theoretical models or in paleoclimate data.

Construction and validation of a new media marketing influence assessment model

Abstract In the digital era, the proliferation of new media, facilitated by digital platforms, has positioned new media marketing as a predominant marketing strategy. This study introduces a novel node ranking algorithm, leveraging the principles of PageRank, and proposes the UIEM-CMR influence assessment model derived from it. Utilizing data extracted from microblogging platforms and Facebook, this model evaluates the influence of various new media marketing nodes. Subsequently, the ten most influential nodes within the microblogging dataset were analyzed to examine the correlation between node influence in new media marketing and both the thematic distribution of new media marketing and the community distribution of followers. The findings reveal that the MR value of node influence, as calculated by the model, is impacted by the combined effects of AR and BR values, with these values alone identified as pivotal. The influence ranking, when solely based on AR and BR values, tends to diverge significantly from real-world scenarios. Nodes ranked highly under popular new media marketing topics exhibit a substantially greater probability of distribution compared to lower-ranked or randomly chosen nodes. Conversely, the distribution probabilities among influential nodes under less popular (cold) new media marketing topics show no significant disparity. Nodes with high influence ratings tend to attract followers from at least two distinct communities. The UIEM-CMR model, as developed in this study, proves to be an effective tool for assessing the influence of new media marketing strategies.

Effectiveness of USG-guided corticosteroid injection administered into the glenohumeral joint and oral prednisone treatment in patients with adhesive capsulitis

Objective: This study aims to compare the efficacy of ultrasonography-guided corticosteroid injection to the glenohumeral joint and oral steroid therapy on clinical response and inferior axillary pouch (AR) thickness measured by ultrasonography (USG) in patients with adhesive capsulitis (AC). Methods: Our prospective randomized study included 48 patients (18-65 years) with a diagnosis of AC. The first group (n=24) underwent USG-guided corticosteroid injection to glenohumeral joint. In the second group (n=24), oral prednisone was started at 0.5 mg/kg dose with the dosing schedule determined by decreasing and continued for 6 weeks. Both groups were also included in a standard physical therapy program (electrotherapy + exercises). The questionnaire, active and passive shoulder joint ROM measurements, Shoulder Pain and Disability Index, evaluation of the joint with USG, and AR thickness measurements were performed. Results: There was a statistically significant increase in passive-active ROM values in all directions before and after the treatment (p&lt;0.05) and decrease in AR values after the treatment (p&lt;0.001) in both groups. However, there was no significant difference between the two groups. In addition, the decrease in inferior pouch thickness and the decrease in SPADI scores were positively correlated. Conclusion: Steroid injection into the glenohumeral joint and oral steroid use significantly reduced shoulder pain and disability and increased range of motion in AC patients. Moreover, both oral steroid and steroid injection treatments improved radiologic findings (by reducing AR), consistent with clinical response. Although both treatments were effective, they were not superior to each other.

The tendency towards equalization of the 234U/238U isotopic activity ratios in fractions of U(IV) and U(VI) during thermal annealing of metamict polycrase

The fate of the immobilized actinides of the spent nuclear fuel in mineral-like matrices can be predicted by studying the behavior of uranium isotopes as representatives of the actinides in natural analogues. This work deals with the thermochemical behavior of uranium isotopes, which is accompanied by a redox process within the 25–800 °C temperature range in the metamict natural analogue of polycrase. The pattern of the changes in the relative contents of the U(IV) and U(VI) fractions at various temperatures was determined by a radiochemical analysis. The accuracy of the U(IV) and U(VI) values using the method of the chemical shift of the energy on the Lα1 X-ray emission line was verified. The changes in the 234U/238U activity ratios of U(IV) and U(VI) fractions from room temperature to 800 °C revealed that 234U and 238U chose distinct thermochemical behaviors. It was discovered that 234U within the range from room temperature to 600 °C participated in redox processes to a greater proportion than 238U, and in the 700–800 °C temperature range, 238U participated in redox processes to a greater proportion than 234U. In the original polycrase, AR 234U(IV)/238U(IV) = 1.003 ± 0.010 and AR 234U(VI)/238U(VI) = 0.944 ± 0.005 were obtained. After heating the polycrase at 400 °C, AR 234U(IV)/238U(IV) value increased to 1.022 ± 0.010; AR 234U(VI)/238U(VI) value decreased to 0.928 ± 0.007. Currently, we do not understand where the different chemical behavior of the two isotopes of an element comes from. It is hardly surprising that at 800 °C, the values of AR (234U/238U) in both valence forms of U(IV) and U(VI) equalize and acquire the total initial value AR (Σ) = 0.963 ± 0.004. It is remains unclear to us at the moment what unknown laws and mechanisms these isotopes follow. The above uncertainties were not addressed in this work; it is hoped that mysteries of nature will be more explained in future research.

Flow-induced vibration of an elliptic cylinder with a splitter-plate attachment at low-Reynolds number: Self-limited oscillations

Flow-induced vibrations (FIV) of a rigid, elastically-mounted elliptical cylinder-plate assembly which is free to move in the cross-flow (transverse) direction is studied using numerical simulations. These simulations were conducted for a laminar flow at a Reynolds number of Re=100 over a reduced velocity range of Ur= 2–30, with a low mass ratio (m∗=10) and zero structural damping, for various values of the aspect ratio AR of the elliptical cylinder; namely, AR= 0.5, 0.67, 0.75, 1, 1.5 and 2. It is shown that the characteristics of the FIV response of an elliptical cylinder-plate assembly that occurs over a limited velocity range (viz., self-limited FIV) such as the vibration amplitude, the reduced-velocity range with vibrations, the nature of the branching behaviour (e.g., synchronization and non-synchronization branches in the amplitude response), and the vortex-shedding (wake) modes are strongly dependent on the aspect ratio. The self-limited FIV response of the assembly is enhanced for AR increasing from 0.75 to 1.5. However, it is found that for AR=2, the reduced-velocity range over which the FIV response occurs is significantly shortened owing to the absence of a non-synchronization branch in the amplitude response for this case. There is a critical value (AR)cri of the aspect ratio below which oscillations in an elliptical cylinder-plate assembly cannot be induced. This critical value occurs in the range 0.67<(AR)cri<0.75 for an assembly in a laminar flow at Re=100 for a fixed splitter-plate length LSP/D=0.5 (D is the equivalent diameter of the ellipsoidal cylinder). A careful analysis shows that there is close relationship between the presence of structural oscillations in the assembly and the location of flow separation points on the windward surface of the elliptical cylinder.

Aspect ratio influence on the vortex induced vibrations of a pivoted finite height cylinder at low Reynolds number

The effect of the aspect ratio on the vortex induced vibrations (VIV) of a pivoted finite length circular cylinder is investigated. A fixed value of the Reynolds number Re = 100 with four values of the aspect ratio AR=2, 3, 5, 7 is considered. Different values of the reduced velocity ur* in the range 2≤ur*≤11 were used for each AR value with a fixed value of the reduced mass mr*=5. Results on the oscillatory response of the cylinder, hydrodynamic forces, and wake structures are reported. In order to compare the VIV of the different length cylinders, the displacement of the center of mass (which coincides on each case) was analyzed. It is found that the maximum oscillation amplitudes, the extent of the synchronization region, and the wake structures are influenced by the aspect ratio. Also, a steady symmetrical flow is obtained for the small AR=2, 3 cases with relatively low values of ur*, which is found to be unstable when increasing ur*.

Adverse perinatal outcomes attributable to HIV in sub-Saharan Africa from 1990 to 2020: Systematic review and meta-analyses

BackgroundMaternal HIV infection and antiretroviral drugs (ARVs) are associated with increased risks of adverse perinatal outcomes. The vast majority of pregnant women living with HIV (WLHIV) reside in sub-Saharan Africa. We aimed to determine the burden of adverse perinatal outcomes attributable to HIV and ARVs in sub-Saharan Africa between 1990 and 2020.MethodsWe conduct a systematic review of studies on the association of pregnant WLHIV with adverse perinatal outcomes in sub-Saharan Africa. We perform random-effects meta-analyses to determine the risk difference (attributable risk, AR) of perinatal outcomes among WLHIV receiving no ARVs, monotherapy, or combination antiretroviral therapy (cART) initiated antenatally or preconception, compared to HIV-negative women. We estimate numbers of perinatal outcomes attributable to HIV and ARVs by combining the AR values with numbers of WLHIV receiving different ARV regimens in each country in sub-Saharan Africa annually between 1990 and 2020.ResultsWe find that WLHIV receiving no ARVs or cART initiated antenatally or preconception, but not monotherapy, have an increased risk of preterm birth (PTB), low birthweight (LBW) and small for gestational age (SGA), compared to HIV-negative women. Between 1990 and 2020, 1,921,563 PTBs, 2,119,320 LBWs, and 2,049,434 SGAs are estimated to be attributable to HIV and ARVs in sub-Saharan Africa, mainly among WLHIV receiving no ARVs, while monotherapy and preconception and antenatal cART averted many adverse outcomes. In 2020, 64,585 PTBs, 58,608 LBWs, and 61,112 SGAs were estimated to be attributable to HIV and ARVs, the majority among WLHIV receiving preconception cART.ConclusionsAs the proportion of WLHIV receiving preconception cART increases, the burden of adverse perinatal outcomes among WLHIV in sub-Saharan Africa is likely to remain high.Systematic review registration numberCRD42021248987

Molecular features of androgen-receptor low, estrogen receptor-negative breast cancers in the Carolina breast cancer study

PurposeAndrogen receptor (AR) expression is absent in 40–90% of estrogen receptor (ER)-negative breast cancers. The prognostic value of AR in ER-negative patients and therapeutic targets for patients absent in AR remains poorly explored.MethodsWe used an RNA-based multigene classifier to identify AR-low and AR-high ER-negative participants in the Carolina Breast Cancer Study (CBCS; N = 669) and The Cancer Genome Atlas (TCGA; N = 237). We compared AR-defined subgroups by demographics, tumor characteristics, and established molecular signatures [PAM50 risk of recurrence (ROR), homologous recombination deficiency (HRD), and immune response].ResultsAR-low tumors were more prevalent among younger (RFD = + 10%, 95% CI = 4% to 16%) participants in CBCS and were associated with HER2 negativity (RFD = − 35%, 95% CI = − 44% to − 26%), higher grade (RFD = + 17%, 95% CI = 8% to 26%), and higher risk of recurrence scores (RFD = + 22%, 95% CI = 16.1% to 28%), with similar results in TCGA. The AR-low subgroup was strongly associated with HRD in CBCS (RFD = + 33.3%, 95% CI = 23.8% to 43.2%) and TCGA (RFD = + 41.5%, 95% CI = 34.0% to 48.6%). In CBCS, AR-low tumors had high adaptive immune marker expression.ConclusionMultigene, RNA-based low AR expression is associated with aggressive disease characteristics as well as DNA repair defects and immune phenotypes, suggesting plausible precision therapies for AR-low, ER-negative patients.