This book is the natural continuation of Computational Commutative Algebra 1 with some twists.
The main part of this book is a breathtaking passeggiata through the computational domains of graded ...rings and modules and their Hilbert functions. Besides Gröbner bases, we encounter Hilbert bases, border bases, SAGBI bases, and even SuperG bases.
The tutorials traverse areas ranging from algebraic geometry and combinatorics to photogrammetry, magic squares, coding theory, statistics, and automatic theorem proving. Whereas in the first volume gardening and chess playing were not treated, in this volume they are.
This is a book for learning, teaching, reading, and most of all, enjoying the topic at hand. The theories it describes can be applied to anything from children's toys to oil production. If you buy it, probably one spot on your desk will be lost forever!
Pathological tissue on the surface of the retina that can be of different etiology and pathogenesis can cause changes in the retina that have a direct consequence on vision. Tissues of different ...etiology and pathogenesis have different morphological structures and also different macromolecule compositions usually characteristic of specific diseases. In this study, we evaluated and compared biochemical differences among samples of three different types of epiretinal proliferations: idiopathic epiretinal membrane (ERMi), membranes in proliferative vitreoretinopathy (PVRm), and proliferative diabetic retinopathy (PDRm). The membranes were analyzed by using synchrotron radiation-based Fourier transform infrared micro-spectroscopy (SR-FTIR). We used the SR-FTIR micro-spectroscopy setup, where measurements were set to achieve a high resolution that was capable of showing clear biochemical spectra in biological tissue. We were able to identify differences between PVRm, PDRm, and ERMi in protein and lipid structure; collagen content and collagen maturity; differences in proteoglycan presence; protein phosphorylation; and DNA expression. Collagen showed the strongest expression in PDRm, lower expression in ERMi, and very low expression in PVRm. We also demonstrated the presence of silicone oil (SO) or polydimethylsiloxane in the structure of PVRm after SO endotamponade. This finding suggests that SO, in addition to its many benefits as an important tool in vitreoretinal surgery, could be involved in PVRm formation.
The transition from paediatric to adult-based health care is a challenging period bearing a high risk of medication nonadherence and transplant loss in adolescents and young adults after kidney ...transplantation. Successful transition asks for the cooperation of many, not least the adult physicians. Yet little is known about their thoughts and attitudes on the transition. We conducted a cross-sectional mixed-methods study, inviting all nephrologists registered with the German Society of Nephrology. A total of 119/1984 nephrologists answered an online survey, and 9 nephrologists participated in expert interviews on transition experiences and perceived barriers. Interviews were thematically analysed. Based on the results, 30 key statements were listed and returned to participants for a ranking of their relevance. The main themes extracted are (1) available resources, (2) patient-related factors, (3) qualification and (4) preparation of and cooperation with the paediatric setting. In conclusion, it became evident that successful transition faces multiple obstacles. At the least, it asks for time, staff, and money. Rigid structures in health care leave little room for addressing the specific needs of this small group of patients. Transition becomes a topic one wants to and is able to afford.
Ultraviolet (UV) irradiation is an important risk factor in cataractogenesis. Lens epithelial cells (LECs), which are a highly metabolically active part of the lens, play an important role in ...UV-induced cataractogenesis. The purpose of this study was to characterize cell compounds such as nucleic acids, proteins, and lipids in human UV C-irradiated anterior lens capsules (LCs) with LECs, as well as to compare them with the control, non-irradiated LCs of patients without cataract, by using synchrotron radiation-based Fourier transform infrared (SR-FTIR) micro-spectroscopy. In order to understand the effect of the UV C on the LC bio-macromolecules in a context of cataractogenesis, we used the SR-FTIR micro-spectroscopy setup installed on the beamline MIRAS at the Spanish synchrotron light source ALBA, where measurements were set to achieve a single-cell resolution with high spectral stability and high photon flux. UV C irradiation of LCs resulted in a significant effect on protein conformation with protein formation of intramolecular parallel β-sheet structure, lower phosphate and carboxyl bands in fatty acids and amino acids, and oxidative stress markers with significant increase of lipid peroxidation and diminishment of the asymmetric CH3 band.
A differential fault attack framework for the Enocoro family of stream ciphers is presented. We only require that the attacker can reset the internal state and inject a random byte-fault, in a random ...register, during a known time period. For a single fault injection, we develop a differential clocking algorithm that computes a set of linear equations in the in- and output differences of the non-linear parts of the cipher and relates them to the differential keystream. The usage of these equations is two-fold. Firstly, one can determine those differentials that can be computed from the faulty keystream, and secondly they help to pin down the actual location and timing of the fault injection. Combining these results, each fault injection gives us information on specific small parts of the internal state. By encoding the information we gain from several fault injections using the weighted Horn clauses, we construct a guessing path that can be used to quickly retrieve the internal state using a suitable heuristic. Finally, we evaluate our framework with the ISO-standardized and CRYPTREC candidate recommended cipher Enocoro-128v2. Simulations show that, on average, the secret key can be retrieved within 20 min on a standard workstation using less than five fault injections.
A fault injection framework for the decryption algorithm of the Niederreiter
public-key cryptosystem using binary irreducible Goppa codes and classical
decoding techniques is described. In ...particular, we obtain low-degree
polynomial equations in parts of the secret key. For the resulting system of
polynomial equations, we present an efficient solving strategy and show how to
extend certain solutions to alternative secret keys. We also provide estimates
for the expected number of required fault injections, apply the framework to
state-of-the-art security levels, and propose countermeasures against this type
of fault attack.
Linking organisms or groups of organisms to specific functions within natural environments is a fundamental challenge in microbial ecology. Advances in technology for manipulating and analyzing ...nucleic acids have made it possible to characterize the members of microbial communities without the intervention of laboratory culturing. Results from such studies have shown that the vast majority of soil organisms have never been cultured, highlighting the risks of culture-based approaches in community analysis. The development of culture-independent techniques for following the flow of substrates through microbial communities therefore represents an important advance. These techniques, collectively known as stable isotope probing (SIP), involve introducing a stable isotope-labeled substrate into a microbial community and following the fate of the substrate by extracting diagnostic molecular species such as fatty acids and nucleic acids from the community and determining which specific molecules have incorporated the isotope. The molecules in which the isotope label appears provide identifying information about the organism that incorporated the substrate. Stable isotope probing allows direct observations of substrate assimilation in minimally disturbed communities, and thus represents an exciting new tool for linking microbial identity and function. The use of lipids or nucleic acids as the diagnostic molecule brings different strengths and weaknesses to the experimental approach, and necessitates the use of significantly different instrumentation and analytical techniques. This short review provides an overview of the lipid and nucleic acid approaches, discusses their strengths and weaknesses, gives examples of applications in various settings, and looks at prospects for the future of SIP technology.
The thermal imaging of surfaces with microscale spatial resolution over micro-sized areas remains a challenging and time-consuming task. Surface thermal imaging is a very important characterization ...tool in mechanical engineering, microelectronics, chemical process engineering, optics, microfluidics, and biochemistry processing, among others. Within the realm of electronic circuits, this technique has significant potential for investigating hot spots, power densities, and monitoring heat distributions in complementary metal-oxide-semiconductor (CMOS) platforms. We present a new technique for remote non-invasive, contactless thermal field mapping using synchrotron radiation-based Fourier-transform infrared microspectroscopy. We demonstrate a spatial resolution better than 10 um over areas on the order of 12,000 um
measured in a polymeric thin film on top of CaF
substrates. Thermal images were obtained from infrared spectra of poly(methyl methacrylate) thin films heated with a wire. The temperature dependence of the collected infrared spectra was analyzed via linear regression and machine learning algorithms, namely random forest and k-nearest neighbor algorithms. This approach speeds up signal analysis and allows for the generation of hyperspectral temperature maps. The results here highlight the potential of infrared absorbance to serve as a remote method for the quantitative determination of heat distribution, thermal properties, and the existence of hot spots, with implications in CMOS technologies and other electronic devices.
It is generally believed that water transport across biological membranes is essentially a near-instantaneous process, with water molecules diffusing directly across the membrane as well as through ...pores such as aquaporins. As a result of these processes by which water can equilibrate across a membrane, a common assumption is that intracellular water is isotopically indistinguishable from extracellular water. To test this assumption directly, we measured the hydrogen isotope ratio of intracellular water in Escherichia coli cells. Our results demonstrate that more than 50% of the intracellular water hydrogen atoms in log-phase E. coli cells are isotopically distinct from the growth medium water and that these isotopically distinct hydrogen atoms are derived from metabolic processes. As expected, the 2H/1H isotope ratio of intracellular water from log-phase cells showed an appreciably larger contribution from metabolic water than did intracellular water from stationary-phase cells (53 ± 12 and 23 ± 5%, respectively). The 2H/1H isotope ratio of intracellular water was also monitored indirectly by measuring the isotope ratio of fatty acids, metabolites that are known to incorporate hydrogen atoms from water during biosynthesis. Significantly, the difference in the isotopic composition of intracellular water from log- to stationary-phase E. coli cells was reflected in the hydrogen isotope ratio of individual fatty acids harvested at the two different times, indicating that the isotope ratio of metabolites can be used as an indirect probe of metabolic activity. Together, these results demonstrate that contrary to the common assumption that intracellular water is isotopically identical to extracellular water, these two pools of water can actually be quite distinct.
Nanofibrillated cellulose is a key material for paving the path toward oil-free renewable materials. In this work, we give new insights on fundamental optical, vibrational and mechanical aspects of ...this form of cellulose, demonstrating its optical bandgap and improved surface stability in cyclically interchanging environmental conditions.
Nanofibrillated cellulose, a polymer that can be obtained from one of the most abundant biopolymers in nature, is being increasingly explored due to its outstanding properties for packaging and device applications. Still, open challenges in engineering its intrinsic properties remain to address. To elucidate the optical and mechanical stability of nanofibrillated cellulose as a standalone platform, herein we report on three main findings: (i) for the first time an experimental determination of the optical bandgap of nanofibrillated cellulose, important for future modeling purposes, based on the onset of the optical bandgap of the nanofibrillated cellulose film at Eg≈275nm (4.5eV), obtained using absorption and cathodoluminescence measurements. In addition, comparing this result with ab-initio calculations of the electronic structure the exciton binding energy is estimated to be Eex≈800meV; (ii) hydrostatic pressure experiments revealed that nanofibrillated cellulose is structurally stable at least up to 1.2GPa; and (iii) surface elastic properties with repeatability better than 5% were observed under moisture cycles with changes of the Young modulus as large as 65%. The results obtained show the precise determination of significant properties as elastic properties and interactions that are compared with similar works and, moreover, demonstrate that nanofibrillated cellulose properties can be reversibly controlled, supporting the extended potential of nanofibrillated cellulose as a robust platform for green-technology applications.
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