Identifying Unauthorized Transactions On Credit Cards By Using Machine Learning Methodologies

It is essential for organizations that issue credit cards to be able to recognize fraudulent credit card transactions. This will prevent consumers from being charged for products that they did not buy with their credit card. The purpose of this project is to demonstrate the modelling of a data set via use of machine learning for the detection of credit card fraud. The problem of detecting fraudulent use of credit cards requires modelling previously completed credit card transactions using the information from those that were determined to be fraudulent. After that, this model is put to use to determine whether or not a new transaction constitutes fraudulent activity. Our goal is to appropriately handle misclassified categories by reducing the number of false Negative cases. During this stage of the process, our primary focuses have been on the analysis and preprocessing of data sets, as well as the application of multiple anomaly detection algorithms these algorithms include the local outlier factor and the isolation forest algorithm. We have used IEEE_CIS Fraud dataset, provided by the kaggle .we applied feature extraction technique to reduce the dimensionality of large dataset by extracting only those principle components with highest variance. Given the class imbalance ratio, we measured the accuracy using the Area Under the Precision-Recall Curve (AUPRC) which gives better results than any other previously used models

Episodic excursions of low-mass protostars on the Hertzsprung-Russell diagram

Following our recent work devoted to the effect of accretion on the pre-main-sequence evolution of low-mass stars, we perform a detailed analysis of episodic excursions of low-mass protostars in the Hertzsprung-Russell (H-R) diagram triggered by strong mass accretion bursts typical of FU Orionis-type objects (FUors). These excursions reveal themselves as sharp increases in the stellar total luminosity and/or effective temperature of the protostar and can last from hundreds to a few thousands of years, depending on the burst strength and characteristics of the protostar. During the excursions, low-mass protostars occupy the same part of the H-R diagram as young intermediate-mass protostars in the quiescent phase of accretion. Moreover, the time spent by low-mass protostars in these regions is on average a factor of several longer than that spent by the intermediate-mass stars in quiescence. During the excursions, low-mass protostars pass close to the position of most known FUors in the H-R diagram, but owing to intrinsic ambiguity the model stellar evolutionary tracks are unreliable in determining the FUor properties. We find that the photospheric luminosity in the outburst state may dominate the accretion luminosity already after a few years after the onset of the outburst, meaning that the mass accretion rates of known FUors inferred from the bolometric luminosity may be systematically overestimated, especially in the fading phase.Comment: 15 pages, 12 figure

Matterwave Transport Without Transit

Classically it is impossible to have transport without transit, i.e., if the points one, two and three lie sequentially along a path then an object moving from one to three must, at some point in time, be located at two. However, for a quantum particle in a three-well system it is possible to transport the particle between wells one and three such that the probability of finding it at any time in the classically accessible state in well two is negligible. We consider theoretically the analogous scenario for a Bose-Einstein condensate confined within a three well system. In particular, we predict the adiabatic transportation of an interacting Bose-Einstein condensate of 2000 Li atoms from well one to well three without transiting the allowed intermediate region. To an observer of this macroscopic quantum effect it would appear that, over a timescale of the order of one second, the condensate had transported, but not transited, a macroscopic distance of 20 microns between wells one and three.Comment: 6 pages, 4 figure

High-resolution [OI] line spectral mapping of TW Hya consistent with X-ray driven photoevaporation

Theoretical models indicate that photoevaporative and magnetothermal winds play a crucial role in the evolution and dispersal of protoplanetary disks and affect the formation of planetary systems. However, it is still unclear what wind-driving mechanism is dominant or if both are at work, perhaps at different stages of disk evolution. Recent spatially resolved observations by Fang et al. (2023) of the [OI] 6300 Angstrom spectral line, a common disk wind tracer, in TW Hya revealed that about 80% of the emission is confined to the inner few au of the disk. In this work, we show that state-of-the-art X-ray driven photoevaporation models can reproduce the compact emission and the line profile of the [OI] 6300 Angstrom line. Furthermore, we show that the models also simultaneously reproduce the observed line luminosities and detailed spectral profiles of both the [OI] 6300 Angstrom and the [NeII] 12.8 micron lines. While MHD wind models can also reproduce the compact radial emission of the [OI] 6300 Angstrom line, they fail to match the observed spectral profile of the [OI] 6300 Angstrom line and underestimate the luminosity of the [NeII] 12.8 micron line by a factor of three. We conclude that, while we cannot exclude the presence of an MHD wind component, the bulk of the wind structure of TW Hya is predominantly shaped by a photoevaporative flow.Comment: 7 pages, 4 figures, accepted for publication in Astrophysical Journal Letter

Clinical progress and pharmacology of small molecule bromodomain inhibitors

Bromodomains have emerged as an exciting target class for drug discovery over the past decade. Research has primarily focused on the bromodomain and extra terminal (BET) family of bromodomains, which has led to the development of multiple small molecule inhibitors and an increasing number of clinical assets. The excitement centred on the clinical potential of BET inhibition has stimulated intense interest in the broader family and the growing number of non-BET bromodomain chemical probes has facilitated phenotypic investigations, implicating these targets in a variety of disease pathways including cancer, inflammation, embryonic development and neurological disorders

Advancements in the development of non-BET bromodomain chemical probes

The bromodomain and extra terminal (BET) family of bromodomain‐containing proteins (BCPs) have been the subject of extensive research over the past decade, resulting in a plethora of high‐quality chemical probes for their tandem bromodomains. In turn, these chemical probes have helped reveal the profound biological role of the BET bromodomains and their role in disease, ultimately leading to a number of molecules in active clinical development. However, the BET subfamily represents just 8/61 of the known human bromodomains, and attention has now expanded to the biological role of the remaining 53 non‐BET bromodomains. Rapid growth of this research area has been accompanied by a greater understanding of the requirements for an effective bromodomain chemical probe and has led to a number of new non‐BET bromodomain chemical probes being developed. Advances since December 2015 are discussed, highlighting the strengths/caveats of each molecule, and the value they add toward validating the non‐BET bromodomains as tractable therapeutic targets

Pregnant Women\u27s perceptions of exposure to brominated flame retardants

Background: Recent media reports on human studies associating brominated flame retardants (BFRs) in household products in pregnancy with urogenital anomalies in boys and endocrine disruption in both sexes. We sought to explore the perceptions of pregnant women of brominated flame retardant (BFR) exposure, in light of recent media reports on the adverse health effects of BFR exposure prenatally. Methods: Pregnant women were recruited for interviews through posters and pamphlets in prenatal clinics, prenatal fairs and community centres. Interviews were audiotaped and transcribed verbatim for Charmaz-based qualitative analysis supported by NVIVO 10™. Results: Theoretical sufficiency was reached after analyzing the interviews of 23 pregnant women. Themes co-constructed were: I-Lack of Awareness of BFRs; II-Factors Influencing BFR Exposure; III-Responsibility; IV-Informed Choice. Almost all participants felt it was difficult to make informed choices to avoid BFRs, and wanted communication from clinicians and regulation from governments regarding decreasing BFR exposure. Conclusion: Pregnant women in Canada may be unaware of the potential risks of exposure to BFRs. Professional organizations and governments should further study risk associated with BFR exposure in pregnancy and provide educational materials for pregnant women and clinicians regarding BFR exposure

Self-consistent modelling of the dust component in protoplanetary and circumplanetary disks: the case of PDS 70

Direct observations of young stellar objects are important to test established theories of planet formation. PDS 70 is one of the few cases where robust evidence favours the presence of two planetary mass companions inside the gap of the transition disk. Those planets are believed to be going through the last stages of accretion from the protoplanetary disk, a process likely mediated by a circumplanetary disk (CPD). We aim to develop a three dimensional radiative transfer model for the dust component of the PDS 70 system which reproduces the system's global features observed at two different wavelengths: 855 $\mu\, \mathrm{m}$ with ALMA and 1.25 $\mu\, \mathrm{m}$ with VLT/SPHERE. We use this model to investigate the physical properties of the planetary companion PDS 70 c and its potential circumplanetary disk. We select initial values for the physical properties of the planet and CPD through appropriate assumptions about the nature and evolutionary stage of the object. We modify iteratively the properties of the protoplanetary disk until the predictions retrieved from the model are consistent with both data sets. We provide a model that jointly explains the global features of the PDS 70 system seen in submillimeter and polarised-scattered light. Our model suggests that spatial segregation of dust grains is present in the protoplanetary disk. The submillimeter modelling of the PDS 70 c source favours the presence of an optically thick CPD and places an upper limit to its dust mass of 0.7 $M_\oplus$. Furthermore, analysis of the thermal structure of the CPD demonstrates that the planet luminosity is the dominant heating mechanism of dust grains inside 0.6 au from the planet while heating by stellar photons dominates at larger planetocentric distances.Comment: accepted for publication in A&

Femoral vectoring for hip dysplasia in neonates

The biomechanical factors influencing the reduction of dislocated hips with the Pavlik harness in patients of developmental hip dysplasia (DDH) were studied and simulated using a three-dimensional Finite Element Method (FEM) computer model. We identified five hip adductor muscles as key mediators in the prognosis of reduction for DDH, and determined the non-dimensional force contribution of each muscle in the direction necessary to achieve hip reduction for subluxated and fully dislocated hip joints. Results indicate that the effects of the muscles studied are functions of the severity of DDH. For an abducted and flexed subluxated hip, the Pectineus, Adductor Brevis, proximal Adductor Magnus, and Adductor Longus muscles aid reduction, while the portions of the Adductor Magnus muscle with middle and distal femoral insertion contribute negatively. For a fully dislocated hip all muscles contribute detrimentally. Consequently, our study points at the adductor muscles as the mediators of reductions of subluxated hips, and suggests the need for external traction to bring fully dislocated hips over the posterior acetabulum and labrum. Additionally, the reduction process of dysplastic hips was found to occur in two phases: (1) Release phase and (2) Reduction phase, and the muscles studied act distinctively in each phase. Moreover, we performed a cadaveric dissection to study the 3-dimensional orientation of the iliopsoas tendon in different hip configurations, and found that in hip abduction and flexion this tendon is likely not an obstruction to DDH reductions. We also report on the development of an improved three-dimensional anatomical computer model of the hip and femora of a 10-week old female infant for further study of hip dysplasia and other conditions of the hip using dynamic simulations and the Finite Element Method. This model was generated by combining CT-scans from four human subjects, as well as muscle positional data. It was segmented to encompass the distinct cartilaginous regions of infant anatomy, as well as the different regions of cortical and cancellous bone; these properties were retrieved from the literature. This engineering computer model of an infant anatomy is being employed f or ( 1) t he development of an anatomy-based finite element and dynamics computer model for simulations of hip dysplasia reductions using novel treatment approaches, (2) the determination of a path of least resistance in reductions of hip dysplasia based on a minimum potential energy approach, (3) the study of the mechanics of hyperflexion of the hip as alternative treatment for late-presenting cases of hip dysplasia, and (4) a comprehensive investigation of the effects of femoral anteversion angle (AV) variations in reductions of hip dysplasia. This study thus reports on an interdisciplinary effort between orthopedic surgeons and mechanical engineers to apply engineering fundamentals to solve medical problems. The results of this research are clinically relevant in pediatric orthopaedics

Interpreting molecular hydrogen and atomic oxygen line emission of T Tauri disks with photoevaporative disk-wind models

Context. Winds in protoplanetary disks play an important role in their evolution and dispersal. However, the physical process that is actually driving the winds is still unclear (i.e. magnetically versus thermally driven), and can only be understood by directly confronting theoretical models with observational data. Aims. We aim to interpret observational data for molecular hydrogen and atomic oxygen lines that show kinematic disk-wind signatures in order to investigate whether or not purely thermally driven winds are consistent with the data. Methods. We use hydrodynamic photoevaporative disk-wind models and post-process them with a thermochemical model to produce synthetic observables for the spectral lines o-H2 1-0 S(1) at 2.12 μm and [OI] 1D2-3P2 at 0.63 μm and directly compare the results to a sample of observations. Results. We find that our photoevaporative disk-wind model is consistent with the observed signatures of the blueshifted narrow low-velocity component (NLVC) -which is usually associated with slow disk winds -for both tracers. Only for one out of seven targets that show blueshifted NLVCs does the photoevaporative model fail to explain the observed line kinematics. Our results also indicate that interpreting spectral line profiles using simple methods, such as the thin-disk approximation, to determine the line emitting region is not appropriate for the majority of cases and can yield misleading conclusions. This is due to the complexity of the line excitation, wind dynamics, and the impact of the actual physical location of the line-emitting regions on the line profiles. Conclusions. The photoevaporative disk-wind models are largely consistent with the studied observational data set, but it is not possible to clearly discriminate between different wind-driving mechanisms. Further improvements to the models are necessary, such as consistent modelling of the dynamics and chemistry, and detailed modelling of individual targets (i.e. disk structure) would be beneficial. Furthermore, a direct comparison of magnetically driven disk-wind models to the observational data set is necessary in order to determine whether or not spatially unresolved observations of multiple wind tracers are sufficient to discriminate between theoretical models