A nyquist criterion for time-varying periodic systems, with application to a hydraulic test bench

In this paper, stability results dedicated to sampled periodic systems are applied to a mechanical system whose stiffness exhibits quick variations: a hydraulic test bench used to achieve mechanical test on complex structures. To carry out this application, time-varying w transformation representation of sampled periodic systems are first introduced. An extension of the Nyquist Criterion to sampled periodic systems is then given. Finally, this theorem is applied to evaluate the stability degree of the hydraulic test bench controlled using CRONE control methodology

"Traversing the Globe - the L'Estrange photographic legacy" - media

Media re the "Traversing the Globe - the L'Estrange photographic legacy

Host response mechanisms in periodontal diseases

Periodontal diseases usually refer to common inflammatory disorders known as gingivitis and periodontitis, which are caused by a pathogenic microbiota in the subgingival biofilm, including Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola that trigger innate, inflammatory, and adaptive immune responses. These processes result in the destruction of the tissues surrounding and supporting the teeth, and eventually in tissue, bone and finally, tooth loss. The innate immune response constitutes a homeostatic system, which is the first line of defense, and is able to recognize invading microorganisms as non-self, triggering immune responses to eliminate them. In addition to the innate immunity, adaptive immunity cells and characteristic cytokines have been described as important players in the periodontal disease pathogenesis scenario, with a special attention to CD4+ T-cells (T-helper cells). Interestingly, the T cell-mediated adaptive immunity development is highly dependent on innate immunity-associated antigen presenting cells, which after antigen capture undergo into a maturation process and migrate towards the lymph nodes, where they produce distinct patterns of cytokines that will contribute to the subsequent polarization and activation of specific T CD4+ lymphocytes. Skeletal homeostasis depends on a dynamic balance between the activities of the bone-forming osteoblasts (OBLs) and bone-resorbing osteoclasts (OCLs). This balance is tightly controlled by various regulatory systems, such as the endocrine system, and is influenced by the immune system, an osteoimmunological regulation depending on lymphocyte- and macrophage-derived cytokines. All these cytokines and inflammatory mediators are capable of acting alone or in concert, to stimulate periodontal breakdown and collagen destruction via tissue-derived matrix metalloproteinases, a characterization of the progression of periodontitis as a stage that presents a significantly host immune and inflammatory response to the microbial challenge that determine of susceptibility to develop the destructive/progressive periodontitis under the influence of multiple behavioral, environmental and genetic factors

Liderazgo y compromiso institucional en enfermeras de la Red de Salud Chupaca 2021

La investigación tuvo como objetivo, determinar la relación entre el liderazgo y el compromiso institucional en enfermeras de la red de salud Chupaca en el 2021, se ajustó al método científico, al método inductivo y el método estadístico inferencial, la investigación fue relacional de corte transversal, se consideró una población de 128 enfermeras que laboraban en los puestos de salud y los centros de salud pertenecientes a la Red de Salud Chupaca en el año 2021, de donde se extrajo una muestra de 98 enfermeras, se empleó el “Inventario de liderazgo en enfermería” y la “Escala de Compromiso Institucional en Enfermería”; entre los resultados se destaca que: el 37.8 % de las enfermeras(os) tienen bajo o muy bajo liderazgo y el 42.5 % de las enfermeras(os) tienen bajo o muy bajo compromiso institucional; asimismo, el incremento del liderazgo; mejora el compromiso institucional en las enfermeras(os); (coeficiente de correlación de Pearson moderado positivo; 0,514**)

Formative E-Assessment of Schema Acquisition in the Human Lexicon as a Tool in Adaptive Online Instruction

This chapter presents a comprehensive method of implementing e-assessment in adaptive e-instruction systems. Specifically, a neural net classifier capable of discerning whether a student has integrated new schema-related concepts from course content into her/his lexicon is used by an expert system with a database containing natural mental representations from course content obtained from students and teachers for adapting e-instruction. Mental representation modeling is used to improve student modeling. Implications for adaptive hypermedia systems and hypertext-based instructions are discussed. Furthermore, it is argued that the current research constitutes a new cognitive science empirical direction to evaluate knowledge acquisition based on meaning information

Microbiological and clinical effects of probiotics and antibiotics on nonsurgical treatment of chronic periodontitis: a randomized placebo- controlled trial with 9-month follow-up

ABSTRACT Objective: The aim of this double-blind, placebo-controlled and parallel- arm randomized clinical trial was to evaluate the effects of Lactobacillus rhamnosus SP1-containing probiotic sachet and azithromycin tablets as an adjunct to nonsurgical therapy in clinical parameters and in presence and levels of Tannerella forsythia, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Material and Methods: Forty-seven systemically healthy volunteers with chronic periodontitis were recruited and monitored clinically and microbiologically at baseline for 3, 6 and 9 months after therapy. Subgingival plaque samples were collected from four periodontal sites with clinical attachment level ≥1 mm, probing pocket depth ≥4 mm and bleeding on probing, one site in each quadrant. Samples were cultivated and processed using the PCR technique. Patients received nonsurgical therapy including scaling and root planing (SRP) and were randomly assigned to a probiotic (n=16), antibiotic (n = 16) or placebo (n = 15) group. L. rhamnosus SP1 was taken once a day for 3 months. Azithromycin 500mg was taken once a day for 5 days. Results: All groups showed improvements in clinical and microbiological parameters at all time points evaluated. Probiotic and antibiotic groups showed greater reductions in cultivable microbiota compared with baseline. The placebo group showed greater reduction in number of subjects with P. gingivalis compared with baseline. However, there were no significant differences between groups. Conclusions: The adjunctive use of L. rhamnosus SP1 sachets and azithromycin during initial therapy resulted in similar clinical and microbiological improvements compared with the placebo group

Dual mechanisms by which MiR-125b represses IRF4 to induce myeloid and B cell leukemias

The oncomir microRNA-125b (miR-125b) is up-regulated in a variety of human neoplastic blood disorders and constitutive up-regulation of miR-125b in mice can promote myeloid and B cell leukemia. We found that miR-125b promotes myeloid and B cell neoplasm by inducing tumorigenesis in hematopoietic progenitor cells. Our study demonstrates that miR-125b induces myeloid leukemia by enhancing myeloid progenitor output from stem cells as well as inducing immortality, self-renewal, and tumorigenesis in myeloid progenitors. Through functional and genetic analyses, we demonstrated that miR-125b induces myeloid and B cell leukemia by inhibiting IRF4 but through distinct mechanisms; it induces myeloid leukemia through repressing IRF4 at the mRNA level without altering the genomic DNA and induces B cell leukemia via genetic deletion of the gene encoding IRF4