Robust topology optimisation of lattice structures with spatially correlated uncertainties

The uncertainties in material and other properties of structures are usually spatially correlated. We introduce an efficient technique for representing and processing spatially correlated random fields in robust topology optimisation of lattice structures. Robust optimisation considers the statistics of the structural response to obtain a design whose performance is less sensitive to the specific realisation of the random field. We represent Gaussian random fields on lattices by leveraging the established link between random fields and stochastic partial differential equations (SPDEs). It is known that the precision matrix, i.e. the inverse of the covariance matrix, of a random field with Mat\'ern covariance is equal to the finite element stiffness matrix of a possibly fractional PDE with a second-order elliptic operator. We consider the discretisation of the PDE on the lattice to obtain a random field which, by design, considers its geometry and connectivity. The so-obtained random field can be interpreted as a physics-informed prior by the hypothesis that the elliptic SPDE models the physical processes occurring during manufacturing, like heat and mass diffusion. Although the proposed approach is general, we demonstrate its application to lattices modelled as pin-jointed trusses with uncertainties in member Young's moduli. We consider as a cost function the weighted sum of the expectation and standard deviation of the structural compliance. To compute the expectation and standard deviation and their gradients with respect to member cross-sections we use a first-order Taylor series approximation. The cost function and its gradient are computed using only sparse matrix operations. We demonstrate the efficiency of the proposed approach using several lattice examples with isotropic, anisotropic and non-stationary random fields and up to eighty thousand random and optimisation variables

Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study

: The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity > 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI

Investigation of the Effect of Amrap and Classic Crossfit Trainings in Wrestlers on Anerobic Power

WOS:000573283800010The aim of this study is to investigate anaerobic power changes of the wrestlers who are performing AMRAP (As many reps or rounds as possible) and Classic Crossfit trainings. The research has been conducted on thirty-two male wrestlers who are challenging in first league of Turkish Wrestling in the season of 2018-2019. The volunteer participants in test groups during eight weeks preseason in preparation stage; Test Group I (Classic Crossfit) and Test Group II (Crossfit AMRAP) have performed Crossfit models three times a week (Monday, Wednesday, Friday). They have participated in routine wrestling trainings in between times (Tuesday, Thursday, Saturday). The data form has been given to identify the demographic features of the participants. The support of specialist physician has been ensured during the implementation of the programs. By creating a measuring parkour and after recording respectively body weight, height and age, 6-30 sec anaerobic power test on wattbikepro has been implemented and it has been recorded on data form. The measurements recorded on data form have been arranged on MS Excel spreadsheet program. When identifying the differences between first and last measurements of anaerobic power values of the participants, two factor variance analysis (two-way ANOVA for repeated measures) has been used in repetitive measurements. As findings, when evaluating results obtained at the end of 8 -week training period, significant changes have been found in group X time interaction dimension in 6-30 sec anaerobic absolute average power (watt) and anaerobic relative average power (watt/kg) values in classic Crossfit training group (p<0,05). According to simple effect test results, it has been seen a change in classic Crossfit training group at the end of the process in 6 sec Anaerobic Absolute Average Power (watt), Anaerobic Relative Average Power (watt/kg) and Anaerobic Absolute Peak Power (watt) values. On the other hand, an interaction has been recorded in AMRAP Crossfit training group only in Anaerobic Absolute Peak Power (watt) values. Consequently, even though it has been ensured that there is a change in a positive way in anaerobic capacity in wrestlers in both Crossfit training models, it has been seen that the effect of classic Crossfit trainings on the performance is more

Hematological Factors for Predicting Methotrexate Efficacy in Tubal Ectopic Pregnancy: A Retrospective Study

Background: Methotrexate (MTX) has emerged as the primary treatment for ectopic pregnancies (EPs), replacing conventional surgical methods. Despite uncertainties regarding its exact mechanism, MTX is thought to induce resorption or tubal abortion of the conceptus. This study aims to identify hematological factors that may predict successful outcomes of MTX in the management of ectopic pregnancy (EP). Methods: In this retrospective cross-sectional study, records of 100 patients diagnosed with tubal EP and treated at the Department of Obstetrics and Gynecology, Health Sciences University Konya City Hospital, between February 2010 and November 2023, were analyzed. Inclusion criteria involved specific conditions for tubal EP diagnosis, along with the administration of a single-dose intramuscular (IM) MTX. Exclusions encompassed other types of EP additional medical conditions, and individuals with smoking habits. Hematological parameters and ratios, including neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), monocyte-lymphocyte ratio (MLR), eosinophil-monocyte ratio (EMR), systemic inflammation response index (SIRI), and systemic immune-inflammation index (SII), were calculated. Results: Descriptive information revealed significant differences between MTX-effective and MTX-ineffective groups in ectopic focus status, number of pregnancies, number of miscarriages, and β-human chorionic gonadotropin (β-hCG) levels on days 1, 4, and 7 after the IM MTX single-dose. However, hematological parameters did not significantly differ based on MTX effectiveness. NLR (p = 0.9611), PLR (p = 0.815), EMR (p = 0.8101), MLR (p = 0.361), and SIRI (p = 0.6811) values did not show a significant difference between MTX effectiveness and ineffectiveness. Conclusions: The study suggests that hematological markers such as NLR, PLR, EMR, MLR, SIRI, and SII may not effectively predictors of MTX efficacy in tubal EP. Limited by a retrospective design and a small sample size, larger-scale studies are crucial for obtaining comprehensive insights and developing reliable predictive tools in clinical contexts

The Effect of Eccentric Strength and Depth Jump Training on Strength, Vertical Jump, and Modified Y Balance on Male Basketball Players

Aim; The aim of this research is to examine the effect of eccentric strength and depth jump training on strength, vertical jump and dynamic balance levels of male basketball players

Management of Snake Bites

Snake bites can cause severe morbidity and mortality. Patient admissions to emergency services due to snake bites are observed to be increased in especially rural areas of our country and in summer months. In this compilation, the current knowledge about snake species living in our country, discrimination of poisonous snakes and non-venomous snakes, and approaches to snake bites has been reviewed

Identification and Properties of Isolated Field Elliptical Galaxies from CFHTLS-W1

We present a catalogue of isolated field elliptical (IfE) galaxies drawn from the W1 field of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). 228 IfEs were identified from a flux-limited (r<21.8) galaxy catalogue which corresponds to a density of 3 IfE/sq.deg. For comparison we consider a sample of elliptical galaxies living in dense environments, based on identification of the brightest cluster galaxies (BGCs) in the same survey. Using the same dataset for the comparison sample ensures a uniform selection, including in the redshift range as IfEs (i.e. 0.1 < z < 0.9). A comparison of elliptical galaxies in different environments reveals that IfEs and BCGs have similar behaviours in their colours, star formation activities, and scaling relations of mass-size and size-luminosity. IfEs and BCGs have similar slopes in the scaling relations with respect to cluster ellipticals within the $-24 \leq M_{r} \leq -22$ magnitude and $10.2< \textrm{log}( \textrm M_{*}/ \textrm M_\odot)\leq12.0$ mass ranges. Three IfEs identified in this study can be associated with fossil groups found in the same survey area which gives clues for future studies.Comment: 23 pages, 18 figures, 10 tables, accepted for publication in PAS