Epiplastral and geographic variation in Echmatemys, a geoemydid turtle from the Eocene of North America: A multi-tiered analysis of epiplastral shape complexity

Numerous geoemydid turtle fossils from the extinct genus Echmatemys have been recovered from the middle Eocene Uinta Formation, Uinta Basin, Utah over the past several decades. Here, we tested whether co-occurring Uintan species Echmatemys callopyge and E. uintensis can be reliably differentiated based on epiplastral morphology, and whether their geospatial distributions overlapped significantly. The geographic spatial and stratigraphic distributions of Uinta Basin E. callopyge and E. uintensis specimens were compared using ArcGIS and analysis of variance (ANOVA). The analysis revealed overlapping geographic distributions of these two species, and no significant differences in stratigraphic dispersal. This finding of extensive geospatial overlap between the two Uintan Echmatemys species highlights the need for accurate taxonomic identification, such as the gular scale morphology validated here. In addition, we sought to address a methodological question regarding the relative efficacy of data complexity in this context. Using epiplastra from three additional Eocene species of Echmatemys, we employed hierarchical analyses of increasing data complexity, from standard linear dimensions to 2D geometric morphometrics to 3D laser scans, to determine the degree to which data complexity contributes to taxonomic assessments within this genus. Uintan species E. callopyge and E. uintensis were found to differ significantly in epiplastral shape as captured by all three categories of data. These findings verify that these two co-occurring species can be differentiated consistently using the shape of the gular scale, and that the use of geometric morphometrics can improve identification of fragmentary specimens. Among the non-Uintan species, dorsal and ventral 2D landmark data reliably differentiated among species, but the linear dimensions were less useful

ERP value determination in South African companies

The theme of this research is to establish how South African companies evaluate the benefits of a capital investment, in terms of ERP implementations, to the organisation. The question of whether determinable value can be quantified and the methods used to calculate such value is explored. A search is conducted for critical success factors for successful ERP implementations, key metrics used for monitoring results, and the approach of South African companies to determining benefits. The research is designed to establish what post purchase analyses of completed projects are conducted and what percentage of completed implementations are considered successful in the South African environment, as well as the possible reasons for those successes and failures. The research consists of firstly a qualitative study of the goals of value creation of ERP decisions, which included a couple of interviews with IT and Process Engineering consultants to form a basis of knowledge for why companies implement ERP systems in the first place, followed by a quantitative descriptive study of the implementation success factors and post implementation analysis, by means of a survey of South African companies. The outcome of the research shows that ERP in South Africa has matured to a level where the majority of projects are judged by the key decision makers to be successful, in contrast to expectations created by the literature review performed. It also highlights that, in the capital budgeting decision making processes followed by companies of different sizes, qualitative factors play a slightly bigger role than quantitative factors in the motivation of an ERP implementation. In addition, this research concludes that companies who identify a clear business value goal with the proposed ERP implementation, ensures buy-in from top management, perform proper planning before embarking on the project, as well as follow some kind of rigorous measurement framework, experience higher levels of ERP success than those who do not. CopyrightDissertation (MBA)--University of Pretoria, 2010.Gordon Institute of Business Science (GIBS)unrestricte

Disclosure of deferred tax : a descriptive study into the appropriateness of different classification methods

The distinction between current and non-current assets and liabilities used in the presentation of financial statements has been challenged for well over the past two decades. Despite this, the distiction is still used today and appears to still have relevance. The purpose of this study is to evaluate and determine the most appropriate method of classification of deferred tax between current and non-current in the context of the objective of financial statements. This is important as information that meets the objective of financial statements is useful to users of financial statements, and might influence their economic decisions. Furthermore, the most appropriate method of classification will have a direct impact on working capital ratios as well as other ratios in financial reporting analyses. A literature review of technical issues together with insights collected from accounting lecturers and technical partners and/or directors by way of a descriptive survey have shown that the destinction of deferred tax assets and liabilities between current and non-current assets and liabilities meets the objective of financial statements. This is in terms of both the current IASB Framework as well as the proposed revised Conceptual Framework. Standard setters in the accounting arena should therefore consider the value such a distinction would add to users of financial statements. This distinction will have the biggest impact on preparers of financial statements, as information of sufficient detail would have to be readily available to enable them to provide users with more relevant information. CopyrightDissertation (MCom)--University of Pretoria, 2008.Taxationunrestricte

Powertrain sizing of electrically supercharged internal combustion engine vehicles

We assess the concept of electrically supercharged internal combustion engines, where the supercharger, consisting of a compressor and an electric motor, draws electric power from a buffer (a battery or a supercapacitor). In particular, we investigate the scenario of downsizing the engine, while delivering high power demands by supercharging. Simultaneously, we seek the optimum buffer size that provides sufficient electric power and energy to run the supercharger, such that the vehicle is able to deliver the performance required by a driving cycle representing the typical daily usage of the vehicle. We provide convex modeling steps that formulate the problem as a second order cone program that not only delivers the optimal engine and buffer size, but also provides the optimal control and state trajectories for a given gear selection strategy. Finally, we provide a case study of sizing the engine and the electric buffer for different compressor power ratings

Right-Handed New Physics Remains Strangely Beautiful

Current data on CP violation in B_d -> eta' K_S and B_d -> phi K_S, taken literally, suggest new physics contributions in b -> s transitions. Despite a claim to the contrary, we point out that right-handed operators with a single weak phase can account for both deviations thanks to the two-fold ambiguity in the extraction of the weak phase from the corresponding CP-asymmetry. This observation is welcome since large mixing in the right-handed sector is favored by many GUT models and frameworks which address the flavor puzzle. There are also interesting correlations with the B_s system which provide a way to test this scenario in the near future.Comment: 7 pages, 9 figures; published version: added 1 reference and 1 clarificatio

Прямые и косвенные директивные речевые акты в речи учащихся

СТУДЕНТЫШКОЛЬНИКИРЕЧЬречевые акты директивныепрагмалингвистик

Pregnancy after living kidney donation, a systematic review of the available evidence, and a review of the current guidance

Understanding and communicating the risk of pregnancy complications post-living kidney donation is imperative as the majority of living kidney donors (LKD) are women of childbearing age. We aimed to identify all original research articles examining complications in post-donation pregnancies and compared the quality and consistency of related guidelines. We searched Embase, MEDLINE, PubMed, society webpages, and guideline registries for English-language publications published up until December 18, 2020. Ninety-three articles were screened from which 16 studies were identified, with a total of 1399 post-donation pregnancies. The outcome of interest, post-donation pregnancy complications, was not calculable, and only a narrative synthesis of the evidence was possible. The absolute risk of pre-eclampsia increased from ~1%–3% pre-donation (lower than the general population) to ~4%–10% post-donation (comparable to the general population). The risks of adverse fetal and neonatal outcomes were no different between post-donation and pre-donation pregnancies. Guidelines and consensus statements were consistent in stating the need to inform LKDs of their post-donation pregnancy risk, however, the depth and scope of this guidance were variable. While the absolute risk of pregnancy complications remains low post-donation, a concerted effort is required to better identify and individualize risk in these women, such that consent to donation is truly informed

Potential of the next generation VHE instruments to probe the EBL (I): the low- and mid-VHE

The diffuse meta-galactic radiation field at ultraviolet to infrared wavelengths - commonly labeled extragalactic background light (EBL) - contains the integrated emission history of the universe. Difficult to access via direct observations indirect constraints on its density can be derived through observations of very-high energy (VHE; E>100 GeV) gamma-rays from distant sources: the VHE photons are attenuated via pair-production with the low energy photons from the EBL, leaving a distinct imprint in the VHE spectra measured on earth. Discoveries made with current generation VHE observatories like H.E.S.S. and MAGIC enabled strong constraints on the density of the EBL especially in the near-infrared. In this article the prospect of future VHE observatories to derive new constraints on the EBL density are discussed. To this end, results from current generation instruments will be extrapolated to the future experiment's sensitivity and investigated for their power to enable new methods and improved constraints on the EBL density.Comment: Accepted for publication in Astroparticle Physics; v2: extended discussion following referees comments, conclusions unchange

Versatile and Sustainable Timed-Release Encryption and Sequential Time-Lock Puzzles

Timed-release encryption (TRE) makes it possible to send information ``into the future\u27\u27 such that a pre-determined amount of time needs to pass before the information can be decrypted, which has found numerous applications. The most prominent construction is based on sequential squaring in RSA groups, proposed by Rivest et al. in 1996. Malavolta and Thyagarajan (CRYPTO\u2719) recently proposed an interesting variant of TRE called homomorphic time-lock puzzles (HTLPs). Here one considers multiple puzzles which can be independently generated by different entities. One can homomorphically evaluate a circuit over these puzzles to obtain a new puzzle. Solving this new puzzle yields the output of a circuit evaluated on all solutions of the original puzzles. While this is an interesting concept and enables various new applications, for constructions under standard assumptions one has to rely on sequential squaring. We observe that viewing HTLPs as homomorphic TRE gives rise to a simple generic construction that avoids the homomorphic evaluation on the puzzles and thus the restriction of relying on sequential squaring. It can be instantiated based on any TLP, such as those based on one-way functions and the LWE assumption (via randomized encodings), while providing essentially the same functionality for applications. Moreover, it overcomes the limitation of the approach of Malavolta and Thyagarajan that, despite the homomorphism, one puzzle needs to be solved per decrypted ciphertext. Hence, we obtain a ``solve one, get many for free\u27\u27 property for an arbitrary amount of encrypted data, as we only need to solve a single puzzle independent of the number of ciphertexts. In addition, we introduce the notion of incremental TLPs as a particularly useful generalization of TLPs, which yields particularly practical (homomorphic) TRE schemes. Finally, we demonstrate various applications by firstly showcasing their cryptographic application to construct dual variants of timed-release functional encryption and also show that we can instantiate previous applications of HTLPs in a simpler and more efficient way