Four simplified gradient elasticity models for the simulation of dispersive wave propagation

Gradient elasticity theories can be used to simulate dispersive wave propagation as it occurs in heterogeneous materials. Compared to the second-order partial differential equations of classical elasticity, in its most general format gradient elasticity also contains fourth-order spatial, temporal as well as mixed spatial temporal derivatives. The inclusion of the various higher-order terms has been motivated through arguments of causality and asymptotic accuracy, but for numerical implementations it is also important that standard discretization tools can be used for the interpolation in space and the integration in time. In this paper, we will formulate four different simplifications of the general gradient elasticity theory. We will study the dispersive properties of the models, their causality according to Einstein and their behavior in simple initial/boundary value problems

Forensic applications of microbiomics: a review

The rise of microbiomics and metagenomics has been driven by advances in genomic sequencing technology, improved microbial sampling methods, and fast-evolving approaches in bioinformatics. Humans are a host to diverse microbial communities in and on their bodies, which continuously interact with and alter the surrounding environments. Since information relating to these interactions can be extracted by analyzing human and environmental microbial profiles, they have the potential to be relevant to forensics. In this review, we analyzed over 100 papers describing forensic microbiome applications with emphasis on geolocation, personal identification, trace evidence, manner and cause of death, and inference of the postmortem interval (PMI). We found that although the field is in its infancy, utilizing microbiome and metagenome signatures has the potential to enhance the forensic toolkit. However, many of the studies suffer from limited sample sizes and model accuracies, and unrealistic environmental settings, leaving the full potential of microbiomics to forensics unexplored. It is unlikely that the information that can currently be elucidated from microbiomics can be used by law enforcement. Nonetheless, the research to overcome these challenges is ongoing, and it is foreseeable that microbiome-based evidence could contribute to forensic investigations in the future

A holomorphic representation of the Jacobi algebra

A representation of the Jacobi algebra $\mathfrak{h}_1\rtimes \mathfrak{su}(1,1)$ by first order differential operators with polynomial coefficients on the manifold $\mathbb{C}\times \mathcal{D}_1$ is presented. The Hilbert space of holomorphic functions on which the holomorphic first order differential operators with polynomials coefficients act is constructed.Comment: 34 pages, corrected typos in accord with the printed version and the Errata in Rev. Math. Phys. Vol. 24, No. 10 (2012) 1292001 (2 pages) DOI: 10.1142/S0129055X12920018, references update

Комплексна діагностика ушкодження хрящової тканини при захворюваннях скронево-нижньощелепного суглоба травматичного характеру

Over the past decades, the diagnostic spectrum of affected articular cartilage has provided many options for recognition, visualization, quantification and analysis related to the progression from focal cartilage damage to the development of a common disease. Accurate diagnosis of the temporomandibular joints damage, especially cartilage tissue, is a prerequisite for successful treatment and helps to improve the prognosis in patients with joint diseases of various etiologies. The aim of the study – to offer updates and proper understanding of the articular cartilage diagnosis for clinical and research purposes from early focal matrix damage and degeneration to a generalized intraarticular process, focusing on reliability, clinical value, current condition and possible use. Materials and Methods. A retrospective analysis of the medical literature was carried out by comparing all possible methods for examination of the temporomandibular joints, including clinical signs and symptoms, x-ray studies, arthroscopy and magnetic resonance imaging (MRI), ultrasound, biochemical parameters, and etc. Results and Discussion. A comparative analysis of instrumental and laboratory parameters proved the feasibility of the latest methods usage for the diagnosis of articular cartilage degradation, such as delayed gadolinium MRI of cartilage, optical coherence tomography and genetic profiling, relating to various aspects of cartilage morphology and functioning. The ability to identify markers of the cartilage damage and their correlation with other indicators makes it possible to diagnose all temporomandibular disorders with reasonable confidence and plan for adequate treatment. Conclusions. The variety of the temporomandibular joint diagnostic methods is based on visualization, biochemical and biomechanical characteristics of the articular cartilage. It is expected that technical improvement and expansion of knowledge about the onset and dynamics of the disease will positively influence on current trends in the diagnosis of the technique and will become a reliable basis for the development of new tretment methods.В течение последних десятилетий спектр диагностики пораженных суставных хрящей предо­ставляет множество вариантов распознавания, визуализации, количественной оценки и анализа, связанных с прогрессированием от очагового повреждения хряща к развитию общего заболевания. Точная диагностика повреждения височно-нижнечелюстных суставов, особенно их хрящевой ткани, является необходимым условием для успешного лечения и способствует улучшению прогноза у пациентов с заболеваниями суставов различной этиологии. Цель исследования – предложить обновление и понимание диагностики суставных хрящей для клинических и исследовательских целей, от раннего поражения матрикса и дегенерации до генерализованного внутрисуставного процесса, акцентируя внимание на надежности, клинической ценности, текущем состоянии и возможным применением. Материалы и методы. Проведен ретроспективный анализ медицинской литературы по сравнением всех возможных способов исследования височно-нижнечелюстных суставов, в т.ч. клинические признаки и симптомы, рентгенографические исследования, артроскопию и магнитно-резонансную томографию (МРТ), ультразвуковое исследование, биохимические показатели и тому подобное. Результаты исследований и их обсуждение. Сравнительный анализ инструментальных и лабораторных показателей доказал целесообразность применения новейших методов диагностики деструкции суставной хрящевой ткани, такие, как замедленная гадолиниева МРТ хряща, оптическая когерентная томография и генетическое профилирование, касающихся различных аспектов морфологии и функционирования хряща. А возможность определения маркеров повреждения хрящевой ткани и их корреляция с другими показателями позволяет с аргументированной уверенностью диагностировать все височно-нижнечелюстные расстройства и планировать адекватное лечение. Выводы. Различные методы диагностики заболеваний височно-нижнечелюстного сустава основаны на визуализации, биохимических и биомеханических характеристиках суставного хряща. Ожидается, что техническое совершенствование и расширение знаний о начале и динамике заболевания положительно влиять на современные тенденции в диагностике методики и станут надежной основой для разработки новых лечебных методик.Протягом останніх десятиліть спектр діагностики уражених суглобових хрящів надає безліч варіантів розпізнавання, візуалізації, кількісної оцінки та аналізу, пов’язаних із прогресуванням від осередкового ушкодження хряща до розвитку загального захворювання. Точна діагностика ушкодження скронево-нижньощелепних суглобів, особливо їх хрящової тканини, є необхідною умовою для успішного лікування та сприяє покращенню прогнозу в пацієнтів із захворюваннями суглобів різної етіології. Мета дослідження – запропонувати оновлення та розуміння діагностики суглобових хрящів для клінічних та дослідних цілей, від раннього ураження матриксу та дегенерації до генералізованого внутрішньосуглобового процесу, акцентуючи увагу на надійності, клінічній цінності, поточному стані та можливим застосуванням. Матеріали і методи. Проведено ретроспективний аналіз медичної літератури з  порівнянням усіх можливих способів дослідження скронево-нижньощелепних суглобів, у т. ч. клінічні ознаки та симптоми, рентгенографічні дослідження, артроскопію та магнітно-резонансну томографію (МРТ), ультразвукове дослідження, біохімічні показники тощо. Результати досліджень та їх обговорення. Порівняльний аналіз інструментальних та лабораторних показників довів доцільність застосування найновіший методів діагностики деструкції суглобової хрящової тканини, такі, як уповільнена гадолінієва МРТ хряща, оптична когерентна томографія та генетичне профілювання, що стосуються різних аспектів морфології та функціонування хряща. А можливість визначення маркерів ушкодження хрящової тканини та їх кореляція з іншими показниками дозволяє з аргументованою впевненістю діагностувати усі скронево-нижньощелепні розлади та планувати адекватне лікування. Висновки. Різноманітні методи діагностики захворювань скронево-нижньощелепного суглоба засновані на візуалізації, біохімічних та біомеханічних характеристиках суглобового хряща. Очікується, що технічне удосконалення та розширення знань про початок та динаміку захворювання позитивно впливатимуть на сучасні тенденції у діагностиці методики та стануть надійною основою для розробки нових лікувальних методик

Theoretical and experimental evidence of a site-selective Mott transition in Fe2O3 under pressure

We provide experimental and theoretical evidence for a novel type of pressure-induced insulator-metal transition characterized by site-selective delocalization of the electrons. M\"ossbauer spectroscopy, X-ray diffraction and electrical transport measurements on Fe$_2$O$_3$ to 100 GPa, along with dynamical mean-field theory (DFT+DMFT) calculations, reveal this site-selective Mott transition between 50 and 68 GPa, such that the metallization can be described by (^\rm{VI}Fe$^{3+\rm{HS}}$)$_2$O$_3$ [$R\bar{3}c$ structure] $\overrightarrow{\tiny\rm{50~GPa}}$ (^\rm{VIII}Fe$^{3+\rm{HS~VI}}$Fe^\rm{M})O$_3$ [$P2_1/n$ structure] $\overrightarrow{\tiny\rm{68~GPa}}$ (^\rm{VI}Fe^\rm{M})$_2$O$_3$ [$Aba2$ structure]. Within the $P2_1/n$ crystal structure, characterized by two distinct coordination sites (VI and VIII), we observe equal abundances of ferric ions (Fe$^{3+}$) and ions having delocalized electrons (Fe^\rm{M}), and only at higher pressures is a fully metallic $Aba2$ structure obtained, all at room temperature. The transition is characterized by delocalization/metallization of the $3d$ electrons on half the Fe sites, with a site-dependent collapse of local moments. Above $\sim$50 GPa, Fe$_2$O$_3$ is a strongly correlated metal with reduced electron mobility (large band renormalizations) of m*/m$\sim$4 and 6 near the Fermi level. Upon decompression, we observe a site-selective (metallic) to conventional Mott insulator phase transition (^\rm{VIII}Fe$^{3+\rm{HS~VI}}$Fe^\rm{M})O$_3$ $\overrightarrow{\tiny\rm{50~GPa}}$ (^\rm{VIII}Fe$^{3+\rm{HS~VI}}$Fe$^{3+ \rm{HS}}$)O$_3$ within the same $P2_1/n$ structure, indicating a decoupling of the electronic and lattice degrees of freedom, characteristic of a true Mott transition. Our results show that the interplay of electronic correlations and lattice may result in rather complex behavior of the electronic structure and magnetic state.Comment: 18 pages, 5 figure

Ankyrin-mediated self-protection during cell invasion by the bacterial predator Bdellovibrio bacteriovorus

Predatory Bdellovibrio bacteriovorus are natural antimicrobial organisms, killing other bacteria by whole-cell invasion. Self-protection against prey-metabolizing enzymes is important for the evolution of predation. Initial prey entry involves the predator’s peptidoglycan DD-endopeptidases, which decrosslink cell walls and prevent wasteful entry by a second predator. Here we identify and characterize a self-protection protein from B. bacteriovorus, Bd3460, which displays an ankyrin-based fold common to intracellular pathogens of eukaryotes. Co-crystal structures reveal Bd3460 complexation of dual targets, binding a conserved epitope of each of the Bd3459 and Bd0816 endopeptidases. Complexation inhibits endopeptidase activity and cell wall decrosslinking in vitro. Self-protection is vital — DBd3460 Bdellovibrio deleteriously decrosslink self-peptidoglycan upon invasion, adopt a round morpholog, and lose predatory capacity and cellular integrity. Our analysis provides the first mechanistic examination of self-protection in Bdellovibrio, documents protection-multiplicity for products of two different genomic loci, and reveals an important evolutionary adaptation to an invasive predatory bacterial lifestyle

New ecological options for the management of horticultural crop pests in Sudano-Sahelian agroecosystems of west Africa

The agroecological approach to agroecosystem management relies on two pillars: vegetational diversification and soil biological activity enhancement. Although crop pests and their natural enemies may be diversely affected by measures derived from these principles, those generally result in increased agroecosystem resilience visà- vis both aerial and soil pests. Earlier studies by ICRISAT and CIRAD and their partners in West Africa showed the potential of the implementation of these principles for the management of some major pests of both staple food and horticultural crops, and their limitations for others, notably in the water-saving and income-generating systems mixing cereals, legumes, and high-value crops currently promoted in the Sudano-Sahelian zones, such as the drip irrigation-based African Market Garden (AMG) and the water harvesting-based Bio-Reclamation of Degraded Lands (BDL) systems. Pigeon-pea showed potential for trap-cropping tomato fruit worm (TFW) on okra, while Andropogon grass was dismissed for such management of stem-borer on pearl millet, and mixed results were obtained with castor bean and other potential trap crops for panicle-feeding bug management on sorghum. The results presented highlight the potential for mobilizing either aerial or soil-bound biological processes for managing fruit flies (FF), the main pest of grafted jujube tree, and leaf worm, the main pest of the Moringa tree, for sustainable production of these two major crops (in BDL and AMG systems, respectively), without having to rely on synthetic pesticide sprays. Studies on the social acceptability of the proposed management options (e.g., pigeon-pea in okra-based BDL) are also underway. The potential of the Jatropha shrub grown as a live-fence around these systems, either for its top-down effects or via the use of its extracts in an assisted push-pull strategy, is discussed. These studies on targeted pathosystems serve the dual purpose of finding solutions to local problems and contribute more globally to the design of pest resilient agrosystems

New ecological options for the management of horticultural crop pests in Sudano-Sahelian agroecosystems of west Africa

The agroecological approach to agroecosystem management relies on two pillars: vegetational diversification and soil biological activity enhancement. Although crop pests and their natural enemies may be diversely affected by measures derived from these principles, those generally result in increased agroecosystem resilience visà- vis both aerial and soil pests. Earlier studies by ICRISAT and CIRAD and their partners in West Africa showed the potential of the implementation of these principles for the management of some major pests of both staple food and horticultural crops, and their limitations for others, notably in the water-saving and income-generating systems mixing cereals, legumes, and high-value crops currently promoted in the Sudano-Sahelian zones, such as the drip irrigation-based African Market Garden (AMG) and the water harvesting-based Bio-Reclamation of Degraded Lands (BDL) systems. Pigeon-pea showed potential for trap-cropping tomato fruit worm (TFW) on okra, while Andropogon grass was dismissed for such management of stem-borer on pearl millet, and mixed results were obtained with castor bean and other potential trap crops for panicle-feeding bug management on sorghum. The results presented highlight the potential for mobilizing either aerial or soil-bound biological processes for managing fruit flies (FF), the main pest of grafted jujube tree, and leaf worm, the main pest of the Moringa tree, for sustainable production of these two major crops (in BDL and AMG systems, respectively), without having to rely on synthetic pesticide sprays. Studies on the social acceptability of the proposed management options (e.g., pigeon-pea in okra-based BDL) are also underway. The potential of the Jatropha shrub grown as a live-fence around these systems, either for its top-down effects or via the use of its extracts in an assisted push-pull strategy, is discussed. These studies on targeted pathosystems serve the dual purpose of finding solutions to local problems and contribute more globally to the design of pest resilient agrosystems