Examining the Risk Factors for Hospital Ransomware Attacks: A Qualitative Study

Ransomware attacks have started to affect the hospital industry and cause major disruptions in operations. There are at least five successful ransomware attacks that have affected hospitals. The only way they were able to regain access to their systems were to submit payment via bitcoin to the entity that conveyed the ransom or recover their systems from backups. In this study, we identified risk factors from published reports for hospital ransomware attacks. This study employed a qualitative review of published news articles and reports that discussed the events of the ransomware attacks. This exploratory method is appropriate for new and emerging topics and used to compare written text to established guidelines or models. We used the NIST Cyber Security Framework to code content and analyze information from journal articles, memos, blogs, research studies and white papers that contained information reported by the hospitals. Hospitals and media reports were not transparent in reporting detailed information surrounding the events of ransomware attacks. Overall, study results demonstrate that there are risk factors for hospitals to become targets for ransomware attacks

Optimal Uncertainty Quantification

We propose a rigorous framework for Uncertainty Quantification (UQ) in which the UQ objectives and the assumptions/information set are brought to the forefront. This framework, which we call \emph{Optimal Uncertainty Quantification} (OUQ), is based on the observation that, given a set of assumptions and information about the problem, there exist optimal bounds on uncertainties: these are obtained as values of well-defined optimization problems corresponding to extremizing probabilities of failure, or of deviations, subject to the constraints imposed by the scenarios compatible with the assumptions and information. In particular, this framework does not implicitly impose inappropriate assumptions, nor does it repudiate relevant information. Although OUQ optimization problems are extremely large, we show that under general conditions they have finite-dimensional reductions. As an application, we develop \emph{Optimal Concentration Inequalities} (OCI) of Hoeffding and McDiarmid type. Surprisingly, these results show that uncertainties in input parameters, which propagate to output uncertainties in the classical sensitivity analysis paradigm, may fail to do so if the transfer functions (or probability distributions) are imperfectly known. We show how, for hierarchical structures, this phenomenon may lead to the non-propagation of uncertainties or information across scales. In addition, a general algorithmic framework is developed for OUQ and is tested on the Caltech surrogate model for hypervelocity impact and on the seismic safety assessment of truss structures, suggesting the feasibility of the framework for important complex systems. The introduction of this paper provides both an overview of the paper and a self-contained mini-tutorial about basic concepts and issues of UQ.Comment: 90 pages. Accepted for publication in SIAM Review (Expository Research Papers). See SIAM Review for higher quality figure

Understanding the structural disorganization of starch in water-ionic liquid solutions

Using synchrotron X-ray scattering analyses and Fourier transform infrared spectroscopy, this work provides insights into the solvent effects of water : [C2mim][OAc] solutions on the disorganization of a starch semi-crystalline structure. When a certain ratio (10.2 : 1 mol/mol) of water : [C2mim][OAc] solution is used, the preferential hydrogen bonding between starch hydroxyls and [OAc]− anions results in the breakage of the hydrogen bonding network of starch and thus the disruption of starch lamellae. This greatly facilitates the disorganization of starch, which occurs much easier than in pure water. In contrast, when 90.8 : 1 (mol/mol) water : [C2mim][OAc] solution is used, the interactions between [OAc]− anions and water suppress the solvent effects on starch, thereby making the disorganization of starch less easy than in pure water. All these differences can be shown by changes in the lamellar and fractal structures: firstly, a preferable increase in the thickness of the crystalline lamellae rather than that of the amorphous lamellae causes an overall increase in the thickness of the semi-crystalline lamellae; then, the amorphous lamellae start to decrease probably due to the out-phasing of starch molecules from them; this forms a fractal gel on a larger scale (than the lamellae) which gradually decreases to a stable value as the temperature increases further. It is noteworthy that these changes occur at temperatures far below the transition temperature that is thermally detectable as is normally described. This hints to our future work that using certain aqueous ionic liquids for destructuration of the starch semi-crystalline structure is the key to realize green processes to obtain homogeneous amorphous materials

Characteristics of starch-based films with different amylose contents plasticised by 1-ethyl-3-methylimidazolium acetate

Starch-based films plasticised by an ionic liquid, 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]), were prepared by a simple compression moulding process, facilitated by the strong plasticisation effect of [Emim][OAc]. The effects of amylose content of starch (regular vs. high-amylose maize) and relative humidity (RH) during ageing of the samples on a range of structural and material characteristics were investigated. Surprisingly, plasticisation by [Emim][OAc] made the effect of amylose content insignificant, contrary to most previous studies when other plasticisers were used. In other words, [Emim][OAc] changed the underlying mechanism responsible for mechanical properties from the entanglement of starch macromolecules (mainly amylose), which has been reported as a main responsible factor previously. The crystallinity of the plasticised starch samples was low and thus was unlikely to have a major contribution to the material characteristics, although the amylose content impacted on the crystalline structure and the mobility of amorphous parts in the samples to some extent. Therefore, RH conditioning and thus the sample water content was the major factor influencing the mechanical properties, glass transition temperature, and electrical conductivity of the starch films. This suggests the potential application of ionic liquid-plasticised starch materials in areas where the control of properties by environmental RH is desired

Different characteristic effects of ageing on starch-based films plasticised by 1-ethyl-3-methylimidazolium acetate and by glycerol

The focus of this study was on the effects of plasticisers (the ionic liquid 1-ethyl-3-methylimidazolium acetate, or [Emim][OAc]; and glycerol) on the changes of starch structure on multiple length scales, and the variation in properties of plasticised starch-based films, during ageing. The films were prepared by a simple melt compression moulding process, followed by storage at different relative humidity (RH) environments. Compared with glycerol, [Emim][OAc] could result in greater homogeneity in [Emim][OAc]-plasticised starch-based films (no gel-like aggregates and less molecular order (crystallites) on the nano-scale). Besides, much weaker starch-starch interactions but stronger starch-[Emim][OAc] interactions at the molecular level led to reduced strength and stiffness but increased flexibility of the films. More importantly, [Emim][OAc] (especially at high content) was revealed to more effectively maintain the plasticised state during ageing than glycerol: the densification (especially in the amorphous regions) was suppressed; and the structural characteristics especially on the nano-scale were stabilised (especially at a high RH), presumably due to the suppressed starch molecular interactions by [Emim][OAc] as confirmed by Raman spectroscopy. Such behaviour contributed to stabilised mechanical properties. Nonetheless, the crystallinity and thermal stability of starch-based films with both plasticisers were much less affected by ageing and moisture uptake during storage (42 days), but mostly depended on the plasticiser type and content. As starch is a typical semi-crystalline bio-polymer containing abundant hydroxyl groups and strong hydrogen bonding, the findings here could also be significant in creating materials from other similar biopolymers with tailored sensitivity and properties to the environment

Facile preparation of starch-based electroconductive films with ionic liquid

Here, we discovered that starch could be straightforwardly processed into optically-transparent electroconductive films, by compression molding at a relatively mild temperature (55 °C or 65 °C), much lower than those commonly used in biopolymer melt processing (typically over 150 °C). Such significantly-reduced processing temperature was achieved with the use of an ionic liquid plasticizer, 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]). A higher [C2mim][OAc] content, lower processing temperature (55 °C), and/or higher relative humidity (RH) (75%) during the sample post-processing conditioning, suppressed the crystallinity of the processed material. The original A-type crystalline structure of starch was eliminated, although small amounts of B-type and V-type crystals were formed subsequently. The starch crystallinity could be linked to the mechanical properties of the films. Moreover, the processing destroyed the original lamellar structure of starch, and the amorphous starch processed with [C2mim][OAc]/water could aggregate on the nanoscale. The films displayed excellent electrical conductivity (> 10−3 S/cm), which was higher with a lower processing temperature (55 °C) and a higher conditioning RH (75%). The incorporation of [C2mim][OAc] reduced the thermal decomposition temperature of starch by 30 °K, while the formulation and processing conditions did not affect the film thermal stability

The challenges in lifetime prediction of oxodegradable polyolefin and biodegradable polymer films

The service lifetime of polymer films is controlled by the chemical reactions leading to chain scission and the mediating environmental factors. For application as agricultural cropping film, controlled accelerated degradation is required. For a photo-sensitive linear low density polyethylene (LLDPE) + 1% nano-titania (as the anatase/rutile mixed phase P25), the environmental factors are not only UV dose and temperature but also soil parameters such as moisture and organic material content. This provides a challenge in predicting the useful lifetime from laboratory accelerated ageing studies. To enhance degradation when the (LLDPE + 1% P25) is buried, UV-C pre-irradiation has been shown to accelerate strength loss but the rate of embrittlement is not sufficient for the application as crop propagation film. Biodegradable poly(butylene adipate-co-terephthalate) or PBAT has a higher rate of degradation when buried outdoors in soil than when buried under laboratory conditions: The elongation at break fell from 900% to 70% in one month in the field while similar changes required 6 months in the laboratory. The small changes in M¯ for embrittlement in the field suggests that the loss of mechanical properties was not linked to bulk property changes but rather to surface morphology (cracks and holes) as seen by SEM. This suggests that even in thin films, enzyme-mediated hydrolysis of PBAT is surface controlled. DNA analysis of the soil around the buried films after 35 days ageing outdoors showed fungi play a more dominant role in PBAT biodegradation compared to bacteria. UV degradation of PBAT film is controlled by the photochemistry of the terephthalate moiety in the polymer and the development of fluorescence is a useful indicator of the extent of photo-degradation

Human Resources and the Resource Based View of the Firm

The resource-based view (RBV) of the firm has influenced the field of strategic human resource management (SHRM) in a number of ways. This paper explores the impact of the RBV on the theoretical and empirical development of SHRM. It explores how the fields of strategy and SHRM are beginning to converge around a number of issues, and proposes a number of implications of this convergence