LCS Tool : A Computational Platform for Lagrangian Coherent Structures

We give an algorithmic introduction to Lagrangian coherent structures (LCSs) using a newly developed computational engine, LCS Tool. LCSs are most repelling, attracting and shearing material lines that form the centerpieces of observed tracer patterns in two-dimensional unsteady dynamical systems. LCS Tool implements the latest geodesic theory of LCSs for two-dimensional flows, uncovering key transport barriers in unsteady flow velocity data as explicit solutions of differential equations. After a review of the underlying theory, we explain the steps and numerical methods used by LCS Tool, and illustrate its capabilities on three unsteady fluid flow examples

LAUNDERING LOVE: A MULTI-CASE ANALYSIS OF THE EVOLUTION OF ROMANCE SCAM VICTIMS INTO CO-OFFENDING MONEY MULES

This thesis addresses the problems of rapidly rising cyber-enabled fraud and concomitant money laundering by focusing on romance scam victims who evolve into willing partners in money laundering schemes, known as “witting money mules.” This thesis explores how and why individuals become money mules after victimization in online romance scams. The thesis employs a grounded theory approach and investigates data from over 134,000 historical text messages between three offenders and 22 victims, as well as three participant interviews with romance scam victims. The data resulted in a grounded theory that a romantically lonely victim who persistently engages online with an offender that strategically repeats scheme-relevant premises in the guise of a romantic partner can result in the victim acceding to the offender’s exploitative requests and the eventual decision to co-offend. This theory also explains how a person can simultaneously be a victim and offender and why they would intentionally choose to help the romance scammer launder money. The literature and data similarly support a suggested definition for “grooming” in the context of romance scams. As a whole, this thesis provides insight into romance scams and money mules as a strategic pivot point that, if disrupted, can simultaneously impact a criminal organization’s ability to profit from romance scams and launder the proceeds of cyber-enabled fraud.Outstanding ThesisCivilian, Minnesota Commerce Fraud BureauApproved for public release. Distribution is unlimited

Electrogenic transport and K(+) ion channel expression by the human endolymphatic sac epithelium.

The endolymphatic sac (ES) is a cystic organ that is a part of the inner ear and is connected to the cochlea and vestibule. The ES is thought to be involved in inner ear ion homeostasis and fluid volume regulation for the maintenance of hearing and balance function. Many ion channels, transporters, and exchangers have been identified in the ES luminal epithelium, mainly in animal studies, but there has been no functional study investigating ion transport using human ES tissue. We designed the first functional experiments on electrogenic transport in human ES and investigated the contribution of K(+) channels in the electrogenic transport, which has been rarely identified, even in animal studies, using electrophysiological/pharmacological and molecular biological methods. As a result, we identified functional and molecular evidence for the essential participation of K(+) channels in the electrogenic transport of human ES epithelium. The identified K(+) channels involved in the electrogenic transport were KCNN2, KCNJ14, KCNK2, and KCNK6, and the K(+) transports via those channels are thought to play an important role in the maintenance of the unique ionic milieu of the inner ear fluid

Expression and mutational analysis of Nm23-H1 in liver metastases of colorectal cancer.

It has been proposed that nm23-H1, a candidate suppressor gene for metastasis, plays an important role in metastasis formation of human tumours. In order to investigate its role in the progression of colorectal cancer, we analysed 22 liver metastases of this malignancy with respect to mutational changes, loss of heterozygosity and expression levels of nm23-H1. Although genetic alterations in nm23-H1 have recently been described in those colorectal adenocarcinomas which give rise to distant metastases, we were unable to detect any mutation in the coding sequence of nm23-H1 in the metastatic tissue itself. We further analysed the metastases with respect to allelic deletions at the chromosomal locus of nm23. However, no loss of heterozygosity could be detected in ten informative cases. Moreover, the mRNA expression levels of nm23-H1 in the metastatic tissues were not significantly different from those in normal colon mucosa. Thus, although nm23-H1 might be involved in metastasis suppression of certain tumour types, in colorectal tumour progression its role remains to be determined

Characterisation of weak layers, physical controls on their global distribution and their role in submarine landslide formation

Submarine landslides pose a hazard to coastal communities as they can generate powerful tsunamis, and threaten critical offshore infrastructure such as seafloor cable networks that underpin global communications. Such events can be orders of magnitude larger than their onshore equivalents. Despite the hazard they pose, many aspects of submarine landslides remain poorly understood, such as why they fail on low angle (<2°), seemingly stable slopes. Many studies have proposed that failure on low slope angles, and the large areal extent of submarine landslides, may be controlled by the presence of laterally-extensive weak layers embedded within the slope stratigraphy, which precondition slopes to failure. Little remains known, however, about the characteristics and processes that control and form weak layers. We conducted a comprehensive review of published submarine landslide studies that examine failure planes and apparent weak layers associated with historical and ancient submarine landslides. Based on a new global landslide catalogue that comprises 64 case studies, this review aims to investigate the types of sediment that form weak layers and to understand the controls on their global variability. Existing classification schemes are based on mechanical process(es), and do not readily enable a diagnosis of weak layers from unfailed sediments. Here, a new and complementary classification of weak layers based on lithology is introduced. This classification enables weak layer recognition from sediment cores (including those sampling unfailed sediments), and allows us to attribute failure mechanisms to different environmental settings where distinct types of weak layers are more likely. The results show that failure planes usually form in the vicinity of an interface between distinct lithologies that together comprise a weak layer. The weak layers of 22 of the 64 case studies were related to characteristic sediment sequences within the slope stratigraphy, of which 19 were classified based on direct measurements from sediment cores and in-situ measurements: 16 weak layers were classified as siliciclastic, four as volcaniclastic, and two as fossiliferous sediment sequences. Only three submarine landsides were related to clay-dominated weak layers. In addition, failure along lithological contrasts was inferred for six case studies. Based on global depositional models likely locations of these different types of weak layer can be inferred. These include oceanic gateways where long-term circulation can create distinct permeability interfaces within siliciclastic sequences, areas of high productivity where biogenic sediments may dominate, and regions that experience widespread ash fall from volcanic eruptions. We highlight that many submarine landslide studies have historically not collected sediment cores that characterise weak layers within intact sedimentary sequences and instead have focused on characterising the slope failure deposit. As weak layers can collapse or become heavily modified during failure, there is a widespread omission of key information required for geotechnical analysis to determine where and why certain slopes are predisposed to failure. We conclude by highlighting the need to combine detailed geotechnical measurements with sedimentological and geophysical analyses including grain-scale observations (e.g. micro-Computed Tomography 3D imagery), and emphasise the importance of a uniform workflow that will allow for a better comparison between individual studies

The Specific Heat of a Ferromagnetic Film.

We analyze the specific heat for the $O(N)$ vector model on a $d$-dimensional film geometry of thickness $L$ using ``environmentally friendly'' renormalization. We consider periodic, Dirichlet and antiperiodic boundary conditions, deriving expressions for the specific heat and an effective specific heat exponent, \alpha\ef. In the case of $d=3$, for $N=1$, by matching to the exact exponent of the two dimensional Ising model we capture the crossover for \xi_L\ra\infty between power law behaviour in the limit {L\over\xi_L}\ra\infty and logarithmic behaviour in the limit {L\over\xi_L}\ra0 for fixed $L$, where $\xi_L$ is the correlation length in the transverse dimensions.Comment: 21 pages of Plain TeX. Postscript figures available upon request from [email protected]