bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk factors for placenta accreta spectrum without prior cesarean section: A case–control study in China
Authors: You Huanyu , Wang Yan , Han Rui , Gu Jinyu , Zeng Lin , Zhao Yangyu
Published: April 2024

Objective

To identify the risk factors for placenta accreta spectrum (PAS) disorders in women without prior cesarean section (CS).

Methods

This retrospective case–control study investigated patients without prior CS who gave birth at Peking University Third Hospital between January 1, 2015 and December 31, 2021. Patients diagnosed with PAS according to the clinical diagnostic criteria of the 2019 International Federation of Gynecology and Obstetrics (FIGO) classification were included as the study group. Patients were matched as the control group according to delivery date and placenta previa, in a 1:2 allocation ratio. Maternal characteristics were compared between the two groups.

Results

The study included 348 patients in the study group and 696 in the control group. The multivariate analysis showed that the independent risk factors of PAS consisted of operative hysteroscopy (once: adjusted odds ratio [aOR] 2.38, 95% CI 1.28–4.24, P = 0.006; twice or more: aOR 5.43, 95% CI 1.04–28.32, P = 0.045), uterine curettage (once: aOR 2.54, 95% CI 1.80–3.58, P < 0.001; twice: aOR 3.01, 95% CI 1.81–5.02, P < 0.001; three or more times: aOR 9.18, 95% CI 4.64–18.18, P < 0.001), multifetal pregnancy (aOR 5.64, 95% CI 3.01–10.57, P < 0.001), adenomyosis (aOR 2.77, 95% CI 1.23–6.22, P = 0.014), in vitro fertilization (aOR 1.51, 95% CI 1.04–2.20, P = 0.030) and pre‐eclampsia (aOR 2.72, 95% CI 1.36–5.45, P = 0.005), and the independent protective factor was being multiparous (aOR 0.37, 95% CI 0.25–0.54, P < 0.001).

Conclusion

After controlling the effect of placenta previa, we found that patients with PAS without prior CS had unique maternal characteristics. Classification and quantification of the intrauterine surgeries they have undergone is essential for identifying high‐risk patients. Early identification of high‐risk groups by risk factors has the potential to improve the prognosis considerably.
Estimating fetal weight in gastroschisis: A 10 year audit of outcomes at the National Maternity Hospital
Authors: O’Keeffe Rachel , Mulligan Karen , McParland Peter , McAuliffe Fionnuala M. , Mahony Rhona , Corcoran Siobhan , O’Connor Clare , Carroll Stephen , Walsh Jennifer
Published: April 2024

Objective

To identify whether conventional methods of estimating fetal growth (Hadlock's formula), which relies heavily on abdominal circumference measurements, are accurate in fetuses with gastroschisis.

Methods

A retrospective cohort study was performed between the period January 1, 2011 and December 31, 2021 in a tertiary referral maternity hospital identifying all pregnancies with a diagnosis of gastroschisis. Projected fetal weight was obtained using the formula (EFW [Hadlock's formula] + 185 g × [X/7]) where X was the number of days to delivery.

Results

During the study period 41 cases were identified. The median maternal age was 25. The median BMI was 25 and 63% were primiparous women (n = 26). Median gestation at diagnosis was 21 weeks. Median gestation at delivery was 36 weeks. A total of 4.8% of mothers had a history of drug use (n = 2). The rate of maternal tobacco use was 21.9% (n = 9). A total of 4.8% of fetuses had additional congenital anomalies including amniotic band syndrome and myelomeningocele (n = 2).

Estimated fetal weight (EFW) and birth weight data were available for 34 cases. A Wilcoxon signed‐rank test showed projected EFW using Hadlock's formula did not result in a statistically significant different birth weight (Z = −1.3, P = 0.169). Median projected weight and actual birth weight were 2241.35 and 2415 g respectively. Median difference was 0.64 g (95% CI: −148 to −28.5).

Conclusion

Our data showed accuracy using standard formulae for EFW in fetuses with gastroschisis.
Insecure attachment and eating disorder symptoms: Intolerance of uncertainty and emotion regulation as mediators
Authors: Jin Ling , Zamudio Gabriel , Wang Chiachih DC , Lin Stacy
Published: April 2024

Objective

Literature on eating disorder (ED) symptoms of Black, Indigenous, and People of Color (BIPOC) group is extremely scarce. This study aimed to understand the mechanisms underlying the associations between insecure attachment and ED symptoms and examine whether these mechanisms differed between White and BIPOC groups.

Method

The study investigated direct and indirect relationship between attachment anxiety/avoidance and ED symptoms via intolerance of uncertainty (IU) and emotion regulation strategies of suppression and reappraisal. Further, we examined whether the proposed mechanisms equally represented White versus BIPOC using Multigroup Structural Equation Model (MG‐SEM). A total of 1227 college students (48.50% BIPOC and 51.50% White) completed research questionnaires.

Results

Results showed that IU and suppression mediated the relations between insecure attachment and ED symptoms for both White and BIPOC groups. Uniquely, reappraisal mediated the relations between insecure attachment and ED symptoms for the White group, but not for the BIPOC group.

Discussion

The implications of the findings for culturally informed practice are discussed, including targeting increasing tolerability of uncertainties and improving emotion regulation to mitigate ED symptoms for those with insecure attachment.
Persistence of IgG and neutralizing antibodies in Crimean−Congo hemorrhagic fever survivors
Authors: Vasmehjani Abbas Ahmadi , Pouriayevali Mohammad Hassan , Shahmahmoodi Shohreh , Salehi‐Vaziri Mostafa
Published: April 2024

The World Health Organization classified Crimean–Congo hemorrhagic fever (CCHF) as a high‐priority infectious disease and emphasized the performance of research studies and product development against it. Little information is available about the immune response due to natural CCHF virus (CCHFV) infection in humans. Here, we investigated the persistence of IgG and neutralizing antibodies in serum samples collected from 61 Iranian CCHF survivors with various time points after recovery (<12, 12−60, and >60 months after disease). The ELISA results showed IgG seropositivity in all samples while a pseudotyped based neutralization assay findings revealed the presence of neutralizing antibody in 29 samples (46.77%). For both IgG and neutralizing antibodies, a decreasing trend of titer was observed with the increase in the time after recovery. Not only the mean titer of IgG (772.80 U/mL) was higher than mean neutralizing antibody (25.64) but also the IgG persistence was longer. In conclusion, our findings provide valuable information about the long‐term persistence of humoral immune response in CCHF survivors indicating that IgG antibody can be detected at least 8 years after recovery and low titers of neutralizing antibody can be detected in CCHF survivors.
Fully automatic online geometric calibration for non‐circular cone‐beam CT orbits using fiducials with unknown placement
Authors: Ma Yiqun Q. , Reynolds Tess , Ehtiati Tina , Weiss Clifford , Hong Kelvin , Theodore Nicholas , Gang Grace J. , Stayman J. Webster
Published: April 2024

Background

Cone‐beam CT (CBCT) with non‐circular scanning orbits can improve image quality for 3D intraoperative image guidance. However, geometric calibration of such scans can be challenging. Existing methods typically require a prior image, specialized phantoms, presumed repeatable orbits, or long computation time.

Purpose

We propose a novel fully automatic online geometric calibration algorithm that does not require prior knowledge of fiducial configuration. The algorithm is fast, accurate, and can accommodate arbitrary scanning orbits and fiducial configurations.

Methods

The algorithm uses an automatic initialization process to eliminate human intervention in fiducial localization and an iterative refinement process to ensure robustness and accuracy. We provide a detailed explanation and implementation of the proposed algorithm. Physical experiments on a lab test bench and a clinical robotic C‐arm scanner were conducted to evaluate spatial resolution performance and robustness under realistic constraints.

Results

Qualitative and quantitative results from the physical experiments demonstrate high accuracy, efficiency, and robustness of the proposed method. The spatial resolution performance matched that of our existing benchmark method, which used a 3D‐2D registration‐based geometric calibration algorithm.

Conclusions

We have demonstrated an automatic online geometric calibration method that delivers high spatial resolution and robustness performance. This methodology enables arbitrary scan trajectories and should facilitate translation of such acquisition methods in a clinical setting.
Cumulative sum control charts for monitoring zero‐inflated COM‐Poisson processes
Authors: Tasias Konstantinos A. , Alevizakos Vasileios
Published: April 2024

The zero‐inflated Conway‐Maxwell Poisson (ZICMP) distribution models count data with many zero observations. ZICMP model has been developed assuming that zero observations exist with probability and the number of non‐conformities in a product unit follows the Conway‐Maxwell Poisson (COM‐Poisson) distribution with location parameter and dispersion parameter . This article presents four kinds of cumulative sum (CUSUM) charts for monitoring upward shifts in a ZICMP process. Three CUSUM schemes, namely ‐CUSUM, ‐CUSUM, and ‐CUSUM, have been designed to detect shift only in one parameter assuming that the other two are fixed and one CUSUM scheme, namely ‐CUSUM, has been designed to detect shifts in all the parameters. The performance of the proposed charts has been evaluated in terms of the average run‐length (ARL). Finally, a numerical example is given to demonstrate the application of the proposed charts.
Robust, Self‐Healing, and Multi‐Use Poly(Urethane‐Urea‐Imide) Elastomer as a Durable Adhesive for Thermal Interface Materials
Authors: Wu Zhiqiang , Dong Jie , Guo Han , Shang Rui , Qin Xiuzhi , Xia Yanfei , Li Xiuting , Zhao Xin , Ji Chengchang , Zhang Qinghua
Published: April 2024

Currently, research on thermal interface materials (TIMs) is primarily focused on enhancing thermal conductivity. However, strong adhesion and multifunctionality are also important characteristics for TIMs when pursing more stable interface heat conduction. Herein, a novel poly(urethane‐urea‐imide) (PUUI) elastomer containing abundant dynamic hydrogen bonds network and reversible disulfide linkages is successfully synthesized for application as a TIM matrix. The PUUI can self‐adapt to the metal substrate surface at moderate temperatures (80 °C) and demonstrates a high adhesion strength of up to 7.39 MPa on aluminum substrates attributed its noncovalent interactions and strong intrinsic cohesion. Additionally, the PUUI displays efficient self‐healing capability, which can restore 94% of its original mechanical properties after self‐healing for 6 h at room temperature. Furthermore, PUUI composited with aluminum nitride and liquid metal hybrid fillers demonstrates a high thermal conductivity of 3.87 W m−1 K−1 while maintaining remarkable self‐healing capability and adhesion. When used as an adhesive‐type TIM, it achieves a low thermal contact resistance of 22.1 mm2 K W−1 at zero pressure, only 16.7% of that of commercial thermal pads. This study is expected to break the current research paradigm of TIMs and offers new insights for the development of advanced, reliable, and sustainable TIMs.
Elastic membranes spanning deformable curves
Authors: Ballarin Francesco , Bevilacqua Giulia , Lussardi Luca , Marzocchi Alfredo
Published: April 2024

We perform a variational analysis of an elastic membrane spanning a closed curve which may sustain bending and torsion. First, we deal with parametrized curves and linear elastic membranes proving the existence of equilibria and finding first‐order necessary conditions for minimizers computing the first variation. Second, we study a more general case, both for the boundary curve and for the membrane, using the framed curve approach. The infinite dimensional version of the Lagrange multipliers' method is applied to get the first‐order necessary conditions. Finally, a numerical approach is presented and employed in several numerical test cases.
Ackermannian Completion of Separators
Authors: Leroux Jérôme
Published: April 2024

Vector addition systems (VAS for short), or equivalently vector addition systems with states, or Petri nets are a long established model of concurrency with extensive applications in modeling and analysis of hardware, software and database systems, as well as chemical, biological and business processes. The central algorithmic problem is reachability: whether from a given initial configuration there exists a sequence of valid execution steps that reaches a given final configuration. The complexity of the problem has remained unsettled since the 1960 s, and was recently proved to be Ackermannian-complete.

In 2009, we proved that the reachability problem can be decided with a simple algorithm by observing that negative instances of the reachability problem can be witnessed by partitioning the set configurations into semilinear sets called complete separators. Since we can decide in elementary time if a pair of semilinear sets denotes a complete separator, the size of such a witness is Ackermannian in the worst case.

In this paper, we show how recent results about the reachability problem can be combined to derive a matching upper-bound, i.e. for every negative instance of the reachability problem, we can effectively compute in Ackermannian time a complete separator witnessing that property.
Fair $$\omega $$-Regular Games
Authors: Hausmann Daniel , Piterman Nir , Sağlam Irmak , Schmuck Anne-Kathrin
Published: April 2024

We consider two-player games over finite graphs in which both players are restricted by fairness constraints on their moves. Given a two player game graph $$G=(V,E)$$

G
=
(
V
,
E
)

and a set of fair moves $$E_f\subseteq E$$

E
f

⊆
E

a player is said to play fair in G if they choose an edge $$e\in E_f$$

e
∈

E
f

infinitely often whenever the source node of e is visited infinitely often. Otherwise, they play unfair. We equip such games with two $$\omega $$
ω
-regular winning conditions $$\alpha $$
α
and $$\beta $$
β
deciding the winner of mutually fair and mutually unfair plays, respectively. Whenever one player plays fair and the other plays unfair, the fairly playing player wins the game. The resulting games are called fair$$\alpha /\beta $$

α
/
β

games.

We formalize fair $$\alpha /\beta $$

α
/
β

games and show that they are determined. For fair parity/parity games, i.e., fair $$\alpha /\beta $$

α
/
β

games where $$\alpha $$
α
and $$\beta $$
β
are given each by a parity condition over G, we provide a polynomial reduction to (normal) parity games via a gadget construction inspired by the reduction of stochastic parity games to parity games. We further give a direct symbolic fixpoint algorithm to solve fair parity/parity games. On a conceptual level, we illustrate the translation between the gadget-based reduction and the direct symbolic algorithm which uncovers the underlying similarities of solution algorithms for fair and stochastic parity games, as well as for the recently considered class of fair games in which only one player is restricted by fair moves.
On-The-Fly Algorithm for Reachability in Parametric Timed Games
Authors: Dahlsen-Jensen Mikael Bisgaard , Fievet Baptiste , Petrucci Laure , de Pol Jaco van
Published: April 2024

Parametric Timed Games (PTG) are an extension of the model of Timed Automata. They allow for the verification and synthesis of real-time systems, reactive to their environment and depending on adjustable parameters. Given a PTG and a reachability objective, we synthesize the values of the parameters such that the game is winning for the controller. We adapt and implement the On-The-Fly algorithm for parameter synthesis for PTG. Several pruning heuristics are introduced, to improve termination and speed of the algorithm. We evaluate the feasibility of parameter synthesis for PTG on two large case studies. Finally, we investigate the correctness guarantee of the algorithm: though the problem is undecidable, our semi-algorithm produces all correct parameter valuations “in the limit”.
Decidable Verification under Localized Release-Acquire Concurrency
Authors: Singh Abhishek Kr , Lahav Ori
Published: April 2024

State reachability for finite state concurrent programs running under Release-Acquire (RA) semantics is known to be undecidable, while under a weaker variant, called Weak-Release-Acquire (WRA), the problem is decidable. However, WRA allows many counterintuitive behaviors not allowed under RA, in which threads locally oscillate between observed values. We propose a strengthening of WRA in the form of a new memory model, which we call Localized Release-Acquire (LRA), that prunes these oscillatory behaviors. We provide semantics for LRA and show that verification under LRA is decidable by extending the potential-based technique used to prove decidability under WRA. The LRA model is still weaker than RA, and thus our results can be used to soundly verify programs under RA.
Witch 3: Validation of Violation Witnesses in the Witness Format 2.0
Authors: Ayaziová Paulína , Strejček Jan
Published: April 2024

Witch 3 is a new validator of violation witnesses in the witness format 2.0. Note that our previous tool,Symbiotic-Witch 2, can validate only violation witnesses in the old GraphML format.Witch 3 validates witnesses of reachability of an error function, overflows, and invalid dereferences and deallocations. Similarly toSymbiotic-Witch 2, the tool is based on symbolic execution and uses parts of theSymbioticframework. Support of the witness format 2.0 inWitch 3 includes features not supported bySymbiotic-Witch 2, such as constraints on the program variables and function return values, specifying statements by column, and providing the concrete statement in which the violation occurs. These additional features can further restrict the explored state space, and, more importantly, allow for much more precise validation.
CPAchecker 2.3 with Strategy Selection
Authors: Baier Daniel , Beyer Dirk , Chien Po-Chun , Jankola Marek , Kettl Matthias , Lee Nian-Ze , Lemberger Thomas , Lingsch-Rosenfeld Marian , Spiessl Martin , Wachowitz Henrik , Wendler Philipp
Published: April 2024

CPAcheckeris a versatile framework for software verification, rooted in the established concept ofconfigurable program analysis. Compared to the last publishedsystem descriptionat SV-COMP 2015, theCPAcheckersubmission to SV-COMP 2024 incorporates new analyses for reachability safety, memory safety, termination, overflows, and data races. To combine forces of the available analyses inCPAcheckerand cover the full spectrum of the diverse program characteristics and specifications in the competition, we usestrategy selectionto predict a sequential portfolio of analyses that is suitable for a given verification task. The prediction is guided by a set of carefully picked program features. The sequential portfolios are composed based on expert knowledge and consist of bit-precise analyses usingk-induction, data-flow analysis, SMT solving, Craig interpolation, lazy abstraction, and block-abstraction memoization. The synergy of various algorithms inCPAcheckerenables support for all properties and categories of C programs in SV-COMP 2024 and contributes to its success in many categories.CPAcheckeralso generates verification witnesses in the new YAML format.
Goblint: Abstract Interpretation for Memory Safety and Termination
Authors: Saan Simmo , Erhard Julian , Schwarz Michael , Bozhilov Stanimir , Holter Karoliine , Tilscher Sarah , Vojdani Vesal , Seidl Helmut
Published: April 2024

Goblintis an abstract interpreter of C programs, focusing on the analysis of multi-threaded code. It is equipped with a variety of abstract domains, as well as analyses which allow it to reason about an array of program properties in a highly configurable manner.Goblinthas been extended with support for the detection of memory safety bugs and non-termination.
Symbiotic 10: Lazy Memory Initialization and Compact Symbolic Execution
Authors: Jonáš Martin , Kumor Kristián , Novák Jakub , Sedláček Jindřich , Trtík Marek , Zaoral Lukáš , Ayaziová Paulína , Strejček Jan
Published: April 2024

Symbiotic 10 brings four substantial improvements. First, we extended our clone ofKleecalledJetKleewithlazy memory initialization. With this extension,JetKleecan symbolically execute a function without knowing its context. In SV-COMP, we use it to handle variables. Second, we have implemented the technique calledcompact symbolic executiontoSlowbeast. Third, we have implemented a non-trivialmay-happen-in-parallelanalysis, which improves slicing of parallel programs. Finally, we have implemented support for violation witnesses in the newwitness format 2.0.
Efficient Matching with Memoization for Regexes with Look-around and Atomic Grouping
Authors: Fujinami Hiroya , Hasuo Ichiro
Published: April 2024

Regular expression (regex) matching is fundamental in many applications, especially in web services. However, matching by backtracking—preferred by most real-world implementations for its practical performance and backward compatibility—can suffer from so-called catastrophic backtracking, which makes the number of backtracking super-linear and leads to the well-known ReDoS vulnerability. Inspired by a recent algorithm by Davis et al. that runs in linear time for (non-extended) regexes, we study efficient backtracking matching for regexes with two common extensions, namely look-around and atomic grouping. We present linear-time backtracking matching algorithms for these extended regexes. Their efficiency relies on memoization, much like the one by Davis et al.; we also strive for smaller memoization tables by carefully trimming their range. Our experiments—we used some real-world regexes with the aforementioned extensions—confirm the performance advantage of our algorithms.
Intel PMDK Transactions: Specification, Validation and Concurrency
Authors: Raad Azalea , Lahav Ori , Wickerson John , Balcer Piotr , Dongol Brijesh
Published: April 2024

Software Transactional Memory (STM) is an extensively studied paradigm that provides an easy-to-use mechanism for thread safety and concurrency control. With the recent advent of byte-addressable persistent memory, a natural question to ask is whether STM systems can be adapted to support failure atomicity. In this paper, we answer this question by showing how STM can be easily integrated with Intel’s Persistent Memory Development Kit (PMDK) transactional library (which we refer to as txPMDK) to obtain STM systems that are both concurrent and persistent. We demonstrate this approach using known STM systems, TML and NOrec, which when combined with txPMDK result in persistent STM systems, referred to as PMDK-TML and PMDK-NORec, respectively. However, it turns out that existing correctness criteria are insufficient for specifying the behaviour of txPMDK and our concurrent extensions. We therefore develop a new correctness criterion, dynamic durable opacity, that extends the previously defined notion of durable opacity with dynamic memory allocation. We provide a model of txPMDK, then show that this model satisfies dynamic durable opacity. Moreover, dynamic durable opacity supports concurrent transactions, thus we also use it to show correctness of both PMDK-TML and PMDK-NORec.
Matrix Representation of Magnetic Pseudo-Differential Operators via Tight Gabor Frames
Authors: Cornean Horia D. , Helffer Bernard , Purice Radu
Published: April 2024

In this paper we use some ideas from [12, 13] and consider the description of Hörmander type pseudo-differential operators on $$\mathbb {R}^d$$

R

d

($$d\ge 1$$

d
≥
1

), including the case of the magnetic pseudo-differential operators introduced in [15, 16], with respect to a tight Gabor frame. We show that all these operators can be identified with some infinitely dimensional matrices whose elements are strongly localized near the diagonal. Using this matrix representation, one can give short and elegant proofs to classical results like the Calderón-Vaillancourt theorem and Beals’ commutator criterion, and also establish local trace-class criteria.
Network effects on information acquisition by DeGroot updaters
Authors: Risco Miguel
Published: April 2024

In today’s world, social networks have a significant impact on information processes, shaping individuals’ beliefs and influencing their decisions. This paper proposes a model to understand how boundedly rational (DeGroot) individuals behave when seeking information to make decisions in situations where both social communication and private learning take place. The model assumes that information is a local public good, and individuals must decide how much effort to invest in costly information sources to improve their knowledge of the state of the world. Depending on the network structure and agents’ positions, some individuals will invest in private learning, while others will free-ride on the social supply of information. The model shows that multiple equilibria can arise, and uniqueness is controlled by the lowest eigenvalue of a matrix determined by the network. The lowest eigenvalue roughly captures how two-sided a network is. Two-sided networks feature multiple equilibria. Under a utilitarian perspective, agents would be more informed than they are in equilibrium. Social welfare would be improved if influential agents increased their information acquisition levels.
Determination of tomato leafminer: Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) damage on tomato using deep learning instance segmentation method
Authors: Uygun Tahsin , Ozguven Mehmet Metin
Published: April 2024

Pests significantly negatively affect product yield and quality in agricultural production. Agricultural producers may not accurately identify pests and signs of pest damage. Thus, incorrect or excessive insecticides may be used. Excessive use of insecticides not only causes human health and environmental pollution, but also increases input costs. Therefore, early detection and diagnosis of pests is extremely important. In this study, the effectiveness of the instance segmentation method, a deep learning-based method, was investigated for the early detection of the damage caused by the T. absoluta pest in the leaf part of the tomato plant under greenhouse conditions. An original dataset was created by acquiring 800 healthy and damaged images under greenhouse conditions. The acquired images were labelled as bounding box and automatically converted to a mask label with the Segment Anything Model (SAM) model. The created dataset was trained with YOLOv8(n/s/m/l/x)-Seg models. As a result of the training, the box performance of the proposed YOLOv8l-Seg model was measured as 0.924 in the mAP0.5 metric. The YOLOv8l-Seg model mask values are, respectively: mAP0.5, mAP0.5–0.95, Precision, Recall showed the best performance with values of 0.935, 0.806, 0.956 and 0.859. Then, the YOLOv8l-Seg model, trained with different data input sizes, showed the best performance at 640 × 640 size and the lowest performance with a value of 0.699 in the  mAP0.5 metric in the 80 × 80 size. The same dataset was trained with YOLOv7, YOLOv5l, YOLACT and Mask R-CNN instance segmentation models and performance comparisons were made with the YOLOv8l-Seg model. As a result, it was determined that the model that best detected T. absoluta damage in tomato plants was the YOLOv8l-Seg model. The Mask R-CNN model showed the lowest performance with a metric of 0.806 mAP0.5. The results obtained from this study revealed that the proposed model and method can be used effectively in detecting the damage caused by the T. absoluta pest.
Extremes of summer Arctic sea ice reduction investigated with a rare event algorithm
Authors: Sauer Jerome , Demaeyer Jonathan , Zappa Giuseppe , Massonnet François , Ragone Francesco
Published: April 2024

Various studies identified possible drivers of extremes of Arctic sea ice reduction, such as observed in the summers of 2007 and 2012, including preconditioning, local feedback mechanisms, oceanic heat transport and the synoptic- and large-scale atmospheric circulations. However, a robust quantitative statistical analysis of extremes of sea ice reduction is hindered by the small number of events that can be sampled in observations and numerical simulations with computationally expensive climate models. Recent studies tackled the problem of sampling climate extremes by using rare event algorithms, i.e., computational techniques developed in statistical physics to reduce the computational cost required to sample rare events in numerical simulations. Here we apply a rare event algorithm to ensemble simulations with the intermediate complexity coupled climate model PlaSim-LSG to investigate extreme negative summer pan-Arctic sea ice area anomalies under pre-industrial greenhouse gas conditions. Owing to the algorithm, we estimate return times of extremes orders of magnitude larger than feasible with direct sampling, and we compute statistically significant composite maps of dynamical quantities conditional on the occurrence of these extremes. We find that extremely low sea ice summers in PlaSim-LSG are associated with preconditioning through the winter sea ice-ocean state, with enhanced downward longwave radiation due to an anomalously moist and warm spring Arctic atmosphere and with enhanced downward sensible heat fluxes during the spring-summer transition. As a consequence of these three processes, the sea ice-albedo feedback becomes active in spring and leads to an amplification of pre-existing sea ice area anomalies during summer.
Elastic medium and torsional spring effects on the nonlocal dynamic of functionally graded porous nanotubes
Authors: Uzun Büşra , Yaylı Mustafa Özgür , Civalek Ömer
Published: April 2024

In this study, Eringen’s nonlocal elasticity theory that applies the small size effects in functionally graded porous nanotubes embedded in an elastic matrix is discussed. The material properties of functionally graded porous nanotubes are taken into account to vary over the radius direction with a rule of mixture. The free torsional vibration relation according to nonlocal elasticity theory, via Hamilton’s principle, is obtained and an eigenvalue solution is constructed for the free torsional vibration response of the presented work. The presented analytical model is validated by comparing the calculated mathematical results for
homogeneous nanotubes with rigid and non-rigid boundary conditions. Special attention is given to deformable boundary conditions, porosity coefficient, material grading coefficient and also to the influence of elastic medium on the free torsional vibration frequencies. In this paper, it has been proven that the influence of length, elastic medium, elastic torsional spring rigidities, material grading and porosity coefficients on the vary in the torsional vibration frequency of the functionally graded nanotube is not small.
A hyperelastic extended Kirchhoff–Love shell model with out-of-plane normal stress: II. An isogeometric discretization method for incompressible materials
Authors: Taniguchi Yasutoshi , Takizawa Kenji , Otoguro Yuto , Tezduyar Tayfun E.
Published: April 2024

This is Part II of a multipart article on a hyperelastic extended Kirchhoff–Love shell model with out-of-plane normal stress. We introduce an isogeometric discretization method for incompressible materials and present test computations. Accounting for the out-of-plane normal stress distribution in the out-of-plane direction affects the accuracy in calculating the deformed-configuration out-of-plane position, and consequently the nonlinear response of the shell. The return is more than what we get from accounting for the out-of-plane deformation mapping. The traction acting on the shell can be specified on the upper and lower surfaces separately. With that, the model is now free from the “midsurface’ location in terms of specifying the traction. In dealing with incompressible materials, we start with an augmented formulation that includes the pressure as a Lagrange multiplier and then eliminate it by using the geometrical representation of the incompressibility constraint. The resulting model is an extended one, in the Kirchhoff–Love category in the degree-of-freedom count, and encompassing all other extensions in the isogeometric subcategory. We include ordered details as a recipe for making the implementation practical. The implementation has two components that will not be obvious but might be critical in boundary integration. The first one is related to the edge-surface moment created by the Kirchhoff–Love assumption. The second one is related to the pressure/traction integrations over all the surfaces of the finite-thickness geometry. The test computations are for dome-shaped inflation of a flat circular shell, rolling of a rectangular plate, pinching of a cylindrical shell, and uniform hydrostatic pressurization of the pinched cylindrical shell. We compute with neo-Hookean and Mooney–Rivlin material models. To understand the effect of the terms added in the extended model, we compare with models that exclude some of those terms.
Geometric linearisation for optimal transport with strongly p-convex cost
Authors: Koch Lukas
Published: April 2024

We prove a geometric linearisation result for minimisers of optimal transport problems where the cost-function is strongly p-convex and of p-growth. Initial and target measures are allowed to be rough, but are assumed to be close to Lebesgue measure.
The concept of privacy in the digital world according to teenagers
Authors: Vespoli Giovanni , Taddei Benedetta , Imbimbo Enrico , De Luca Lisa , Nocentini Annalaura
Published: April 2024

Aim

This study aims first to explore how adolescents define the idea of online privacy and how well they understand all the implications of using their data online, using emergent themes modeling. A co-occurrence analysis comparing narratives was performed to better understand how the concept of online privacy differed according to participants’ age.

Subject and methods

Five hundred eighty-eight adolescents (64.8% female) completed a narrative task about their definition of online privacy. “Reflection of self-online,” “digital safe,” “human right,” and “ability to surf the web and emotional consequences” are the four emergent themes closely related to the adolescents’ definition and meaning of online privacy.

Results

The results did not show differences between the two age groups in the interpretation of the construct, except for the concept of safety. Adolescents older than 15 years used more emotional content.

Conclusion

The findings are discussed in terms of how understanding young people’s online privacy can help to design a safer Internet.
Sludge from sea-based Atlantic salmon (Salmo salar L.) production: quantification, composition, and potential application in integrated multi-trophic aquaculture
Authors: Anglade Inka , Krogli Trygve M. , Reitan Kjell Inge
Published: April 2024

Future growth of Atlantic salmon (Salmo salar L.) in Norway is tied to finding solutions for major ecological challenges connected to salmon lice, escapees, and nutrient emissions from sea cages. At the same time, nutrient-rich sludge from salmon production comprises a valuable resource for the cultivation of lower trophic species using an integrated multi-trophic aquaculture (IMTA) approach. This study aimed to quantify the sedimentation of aquaculture sludge under sea cages of an Atlantic salmon aquaculture site and to qualify the composition of this sludge. Additionally, the study evaluated the hypothetical use of sludge from sea-based aquaculture as a feed source for polychaetes Hediste diversicolor. Using sediment traps, sludge samples were collected under two different Atlantic salmon sea cages, at two different depths, and three different sampling dates. Subsequently, they were quantified, and their composition was assessed with regards to carbon (C), nitrogen (N), phosphorus (P), lipid, fatty acid (FA), protein, amino acid (AA), and ash content as well as elemental ratios and composition of FAs and AAs. The quantity of collected sludge was significantly different between sea cages, with a strong positive correlation between feed input and collected sludge (R2 = 0.98, p < 0.05). Sampling depth did not affect the quantity of collected sludge in the sediment traps (2215 ± 480 mg DW day−1), and no significant difference in sedimented sludge as a proportion of theoretically produced sludge (12.94 ± 2.16%) was found when comparing the different cages and sampling depths. Furthermore, the composition of collected sludge was similar at all sampling points. The overall nutritional value was lower compared to sludge from land-based aquaculture; regardless, sludge from sea-based salmon production can in theory be considered a potential feed resource to be used for the production of polychaetes H. diversicolor.
Depression symptoms modelling from social media text: an LLM driven semi-supervised learning approach
Authors: Farruque Nawshad , Goebel Randy , Sivapalan Sudhakar , Zaïane Osmar R.
Published: April 2024

A fundamental component of user-level social media language based clinical depression modelling is depression symptoms detection (DSD). Unfortunately, there does not exist any DSD dataset that reflects both the clinical insights and the distribution of depression symptoms from the samples of self-disclosed depressed population. In our work, we describe a semi-supervised learning (SSL) framework which uses an initial supervised learning model that leverages (1) a state-of-the-art large mental health forum text pre-trained language model further fine-tuned on a clinician annotated DSD dataset, (2) a Zero-Shot learning model for DSD, and couples them together to harvest depression symptoms related samples from our large self-curated depressive tweets repository (DTR). Our clinician annotated dataset is the largest of its kind. Furthermore, DTR is created from the samples of tweets in self-disclosed depressed users Twitter timeline from two datasets, including one of the largest benchmark datasets for user-level depression detection from Twitter. This further helps preserve the depression symptoms distribution of self-disclosed tweets. Subsequently, we iteratively retrain our initial DSD model with the harvested data. We discuss the stopping criteria and limitations of this SSL process, and elaborate the underlying constructs which play a vital role in the overall SSL process. We show that we can produce a final dataset which is the largest of its kind. Furthermore, a DSD and a Depression Post Detection model trained on it achieves significantly better accuracy than their initial version.
IoT-based eHealth using blockchain technology: a survey
Authors: Allam Aya H. , Gomaa Ibrahim , Zayed Hala H. , Taha Mohamed
Published: April 2024

The eHealth sector has witnessed significant growth due to technological advancements, facilitating care delivery in patients' homes and moving away from traditional hospital settings. Blockchain and the Internet of Things (IoT) play pivotal roles in enhancing healthcare services, offering features such as remote patient monitoring, streamlined electronic medical record (EMR) management, drug traceability, and effective disease control, particularly during events like the COVID-19 pandemic. The growing utilization of IoT devices brings about security challenges, including concerns related to data integrity and device authentication. This paper proposes the integration of blockchain technology as a robust solution. Leveraging its decentralized and tamper-resistant features, blockchain establishes trust among diverse IoT devices, ensuring the integrity of IoT data. Additionally, smart contracts enhance device authentication, fortifying overall security by addressing vulnerabilities associated with centralization. Regarding the management of eHealth, this survey begins with an overview of the industry, highlighting IoT-related challenges in healthcare. It explores various IoT applications in eHealth and discusses how blockchain can effectively address obstacles in healthcare management through IoT. Notably, the paper provides insights into examining consensus algorithm parameters within blockchain systems, clarifying the methodology used to assess and optimize these critical components. The survey extends to a thorough review of existing research on integrating blockchain-based IoT in eHealth. Finally, it presents an overview of challenges and potential solutions for implementing blockchain-based IoT in the eHealth sector. This comprehensive survey aims to empower stakeholders by providing insights to enhance patient care in this dynamic and evolving field.
How using a response system in blended synchronous seminars encourages online and onsite student participation
Authors: Diaz Patricia , Hrastinski Stefan , Norström Per
Published: April 2024

The interest in blended synchronous learning environments has increased dramatically since the COVID-19 pandemic. However, a key challenge is how to simultaneously encourage online and onsite student participation. Response systems have been found to stimulate student participation in classroom and online education settings. This study investigates how online and onsite students participate in blended synchronous seminars where a response system is being used. The data comprises observations of blended synchronous seminars, students’ written reflections, and student interviews, all of which were thematically analyzed. It was found that using a response system encouraged online and onsite students to participate in various ways. Although online students mostly remained quiet, they perceived to engage through listening and thinking, participating in the seminars by absorbing information, and interacting with the content displayed via the response system. The onsite students participated vocally and more spontaneously. All students participated in written, anonymous, and game-based modes, suggesting that there were different and complementary ways for students to participate when using a response system, which extended beyond merely talking or chatting. Notably, most students perceived the response system crucial to their participation in the blended synchronous seminars. The findings underscore the importance of encouraging student participation in blended synchronous learning environments, highlighting response systems as effective tools to encourage onsite and, particularly, online student participation.
On the relevance of query definition in the performance of 3D ligand-based virtual screening
Authors: Vázquez Javier , García Ricardo , Llinares Paula , Luque F. Javier , Herrero Enric
Published: April 2024

Ligand-based virtual screening (LBVS) methods are widely used to explore the vast chemical space in the search of novel compounds resorting to a variety of properties encoded in 1D, 2D or 3D descriptors. The success of 3D-LBVS is affected by the overlay of molecular pairs, thus making selection of the template compound, search of accessible conformational space and choice of the query conformation to be potential factors that modulate the successful retrieval of actives. This study examines the impact of adopting different choices for the query conformation of the template, paying also attention to the influence exerted by the structural similarity between templates and actives. The analysis is performed using PharmScreen, a 3D LBVS tool that relies on similarity measurements of the hydrophobic/philic pattern of molecules, and Phase Shape, which is based on the alignment of atom triplets followed by refinement of the volume overlap. The study is performed for the original DUD-E+ database and a Morgan Fingerprint filtered version (denoted DUD-E+-Diverse; available in https://github.com/Pharmacelera/Query-models-to-3DLBVS), which was prepared to minimize the 2D resemblance between template and actives. Although in most cases the query conformation exhibits a mild influence on the overall performance, a critical analysis is made to disclose factors, such as the content of structural features between template and actives and the induction of conformational strain in the template, that underlie the drastic impact of the query definition in the recovery of actives for certain targets. The findings of this research also provide valuable guidance for assisting the selection of the query definition in 3D LBVS campaigns.

Graphical Abstract
The impact of ultrasound-guided vascular access for catheter ablation of left atrial arrhythmias in a high-volume centre
Authors: Krimphoff Amelie , Urbanek Lukas , Bordignon Stefano , Schaack David , Tohoku Shota , Chen Shaojie , Chun K. R. Julian , Schmidt Boris
Published: April 2024

Background

Vascular complications are a common occurrence during atrial fibrillation ablation. Observational studies indicate that the utilization of ultrasound (US)-guided puncture may decrease the incidence of vascular complications; however, its routine use is not established in many centres.

Methods

Patients undergoing catheter ablation for atrial fibrillation were included sequentially. All patients receiving US-guided punctures were prospectively enrolled (US group), while patients who underwent the procedure with standard puncture technique served as control group (No-US group). Periprocedural vascular complications requiring intervention within 30 days of the procedure were defined as the primary endpoint.

Results

A total of 599 patients (average age: 69 ± 11 years, 62.9% male) were analysed. The incidence of vascular complications was lower with the US-guided puncture than with the anatomic landmark-guided puncture (14/299 [4.7%] vs. 27/300 [9%], p = 0.036). The US-guided vascular access significantly reduced the rate of false aneurysms (3/299 [1%] vs. 12/300 [4%], p = 0.019). In addition, the occurrence of arteriovenous fistula (2/299 [0.7%] vs. 4/300 [1.3%], p = 0.686) and haematoma requiring treatment (9/299 [3%] vs. 11/300 [3.7%], p = 0.655) were also lower in the US group. US-guided puncture did not prolong the procedure time (mean procedure time: 57.48 ± 24.47 min vs. 56.09 ± 23.36 min, p = 0.478). Multivariate regression analysis identified female gender (OR 2.079, CI 95% 1.096–3.945, p = 0.025) and conventional vascular access (OR 2.079, CI 95% 1.025–3.908, p = 0.042) as predictors of vascular complications.

Conclusions

The implementation of US-guided vascular access for left atrial catheter ablation resulted in a significant decrease of the overall vascular complication rate.
Uranium (VI) sorption from aqueous solution using commercial anion exchange resins; kinetics, isotherm, and thermodynamic investigations
Authors: Youssef Walid M. , Masoud Ahmed M. , Elmaadawy Mahmoud M. , Khawassek Yasser M.
Published: April 2024

Commercial strong anion exchange resins provided by Purolite, namely MTA4801PF, and MTA4601PFSO4, were utilized for extracting uranium from sulfate leach liquor. The study focused on investigating the kinetics, isotherms, and thermodynamics of the sorption process. Both resins demonstrated similar kinetics and isotherm performance, with sorption capacities of approximately 66 and 71 mg g−1respectively. The sorption process was proven to be endothermic, feasible, and spontaneous, and U(VI) desorption of around 95% was achieved using 0.5 M sulfuric acid. Commercial resins showed excellent sorption performance when applied to sulfate leach liquor of Egyptian ores despite the complexity of the solution.