3,219 research outputs found
Distributional chaotic generalized shifts
Suppose is a finite discrete space with at least two elements,
is a nonempty countable set, and consider self--map .
We prove that the generalized shift with
(for ) is:
distributional chaotic (uniform, type 1, type 2) if and only if
has at least a non-quasi-periodic point,
dense distributional chaotic if and only if
does not have any periodic point,
transitive distributional chaotic if and only if
is one--to--one without any periodic point.
We complete the text by counterexamples.Comment: 13 page
Strings of group endomorphisms
Recently the strings and the string number of self-maps were used in the
computation of the algebraic entropy of special group endomorphisms. We
introduce two special kinds of strings, and their relative string numbers. We
show that a dichotomy holds for all these three string numbers; in fact, they
admit only zero and infinity as values on group endomorphisms.Comment: 17 page
Actinomycosis may be presented in unusual organs: A report of two cases
Actinomycosis is a chronic granulomatous suppurative disease characterized by direct extension to the contagious tissue with the formation of multiple drainage sinus tracts through which tiny colonies of organisms called sulfur granules are discharged. Here, we report 2 cases of actinomycosis from Iran. One of them had actinomycosis on the hand and the other on the foot. Samples of tissue biopsy showed sulfur granules associated with colonies of actinomyces, thus confirming the diagnosis in both cases. The response to curettage and penicillin therapy was satisfactory in our patients. The chronic and indolent course of actinomycosis resembles tuberculosis, fungal infection and malignancy. So, increasing awareness among the clinicians and clinical microbiologists will help in the early diagnosis of the disease and in the initiation of early and proper treatment
Modeling the collagen fibril network of biological tissues as a nonlinearly elastic material using a continuous volume fraction distribution function
Despite distinct mechanical functions, biological soft tissues have a common microstructure in which a ground matrix is reinforced by a collagen fibril network. The microstructural properties of the collagen network contribute to continuum mechanical tissue properties that are strongly anisotropic with tensile-compressive asymmetry. In this study, a novel approach based on a continuous distribution of collagen fibril volume fractions is developed to model fibril reinforced soft tissues as nonlinearly elastic and anisotropic material. Compared with other approaches that use a normalized number of fibrils for the definition of the distribution function, this representation is based on a distribution parameter (i.e. volume fraction) that is commonly measured experimentally while also incorporating pre-stress of the collagen fibril network in a tissue natural configuration. After motivating the form of the collagen strain energy function, examples are provided for two volume fraction distribution functions. Consequently, collagen second-Piola Kirchhoff stress and elasticity tensors are derived, first in general form and then specifically for a model that may be used for immature bovine articular cartilage. It is shown that the proposed strain energy is a convex function of the deformation gradient tensor and, thus, is suitable for the formation of a polyconvex tissue strain energy function
Family Presence During Resuscitation and/or Invasive Procedures in the Emergency Department: One Size Does Not Fit All
Family presence during resuscitation and/or invasive procedures is receiving more attention today as it speaks to the heart of patient and family-centered care. Family members are the most important support for their loved ones during vulnerable times such as a life-threatening event. Although family presence during resuscitation and/or invasive procedures is becoming a more accepted practice in hospital settings, only 5% of hospitals in the United States have unit policies guiding the practice of family presence in specialty settings.1-5 There is a need for family presence to be studied in non-academic hospitals and in other specialty settings such as emergency departments (ED) and adult intensive care units.2 These environments are unpredictable and professionals have varying opinions regarding benefits of family presence during resuscitation and/or invasive procedures in adults. Currently, there is no hospital policy to guide practice of family presence at our 381 bed non-academic hospital in the Northwest. Acknowledging presence as central to patient care inspired our Evidence-Based Practice (EBP) committee to craft a hospital policy providing guidance for the healthcare team to determine when it is appropriate to offer the option of family presence
Effects of Multiple Bouts of Long-duration Hindlimb Unloading and Recovery on Rat Plantaris Muscle
Exposure to microgravity results in a rapid reduction of muscle mass. However, few studies exist designed to examine the effects of multiple long-term exposures to microgravity with alternating recovery periods on skeletal muscle. To determine what happens to the recovery of skeletal muscle when faced with subsequent unloading and recovery periods. Male Sprague-Dawley (6 mo) were assigned to the following groups as shown in figure 1 below: 28d hindlimb unloading (1HU), 28d HU session followed by a 56d recovery bout of normal cage ambulation at 1g (1HU+REC), 2 cycles of 28d HU with a 56d recovery period between unloadings (2HU), 2 cycles of 28d HU as in the 2HU group, but followed by an additional 56d recovery at 1g (2HU+REC), and an age- and housing-matched control group (CON). On the final day of the experimental period, plantaris muscles were excised and weighed. The 1HU+REC (0.548 ± 0.012), 2HU+REC (0.562 ± 0.015), and CON (0.550 ± 0.013) showed no statistical difference (p\u3e0.05) between each other. The 1 HU (0.442 ± 0.020) and 2 HU (0.431 ± 0.011) groups were significantly less (p\u3c0.001) than recovery and aged control animals but were not significantly different from each other. The results show that the plantaris muscle presented reduction of muscle mass with initial and subsequent exposures to microgravity. However, with the recovery period, animals were able to regain lost muscle mass, similar to age-matched controls. These findings would be relevant for astronauts participating in multiple long-duration missions throughout their career
Effects of Voluntary Resistance Exercise Training During Recovery From Hindlimb Unloading on Rat Gastrocnemius Muscle
As research continues to examine the deleterious impact of long-duration spaceflight on human muscle mass and function, there remain gaps in our knowledge of muscle physiology, especially in examining how muscle’s ability to recover or rehabilitate from unloading may alter the results of multiple exposures to microgravity followed by 1g recovery. The purpose of this study was to analyze the effects of resistance exercise training of gastrocnemius muscle mass and anabolism during the initial recovery period immediately following a bout of unloading, as well as to examine the role that exercise may have on a subsequent period of weightlessness. This was achieved in rodent models of simulated spaceflight (0g), recovery (1g), and resistance training (\u3e1g) using male Sprague-Dawley (6 mo) rats randomly assigned to the following groups: 28d hindlimb unloading (HU), 28d HU followed by a 56d recovery period of normal cage ambulation at 1g (1HU+REC), 2 cycles of 28d HU with a 56d recovery period between unloading (2HU), 2HU followed by an additional 56d recovery at 1g (2HU+REC), or an age- and housing-matched control group (CON). In addition, following the initial 28d HU period, two groups of animals were given 7d recovery at 1g followed by a 7wk (3 sessions/wk) moderate-intensity, moderate-volume voluntary resistance exercise program (EX) in which the animals were trained to perform a squat-like motion with full extension of the lower limb and resistance was applied incrementally by weighted pouches over the scapula to ~65% bodyweight. At the conclusion of the experiments, gastrocnemius muscles were carefully excised, weighed, and evaluated for cumulative (24h) rates of protein synthesis (FSR). Values of both muscle mass and FSR were lower than control during periods of unloading (p\u3c0.05), but with recovery, control values were reached for mass and surpassed for FSR. Interestingly, there was no significant difference between the mass of 2HU and 2HU+EX (p\u3e0.05), and both were diminished in comparison to control animals, suggesting that benefits of exercise during periods of ambulatory reloading after disuse/microgravity may not be additive. In conclusion, our data suggest that given adequate recovery, microgravity-induced losses of muscle mass can be fully restored to control values, and this adaptational response persists even with multiple exposures. These findings may have important implications not only for career astronauts, but also for individuals who have been subjected to casting of a limb or a period of bed rest following severe injury or illness
CSNL: A cost-sensitive non-linear decision tree algorithm
This article presents a new decision tree learning algorithm called CSNL that induces Cost-Sensitive Non-Linear decision trees. The algorithm is based on the hypothesis that nonlinear decision nodes provide a better basis than axis-parallel decision nodes and utilizes discriminant analysis to construct nonlinear decision trees that take account of costs of misclassification.
The performance of the algorithm is evaluated by applying it to seventeen datasets and the results are compared with those obtained by two well known cost-sensitive algorithms, ICET and MetaCost, which generate multiple trees to obtain some of the best results to date. The results show that CSNL performs at least as well, if not better than these algorithms, in more than twelve of the datasets and is considerably faster. The use of bagging with CSNL further enhances its performance showing the significant benefits of using nonlinear decision nodes.
The performance of the algorithm is evaluated by applying it to seventeen data sets and the results are
compared with those obtained by two well known cost-sensitive algorithms, ICET and MetaCost, which generate multiple trees to obtain some of the best results to date.
The results show that CSNL performs at least as well, if not better than these algorithms, in more than twelve of the data sets and is considerably faster.
The use of bagging with CSNL further enhances its performance showing the significant benefits of using non-linear decision nodes
Infections, atherosclerosis, and coronary heart disease.
Atherosclerosis is a chronic inflammatory disease. Pathophysiological similarities between chronic infections and atherosclerosis triggered interest in a clinical association between these conditions. Various infectious microbes have been linked to atherosclerotic vascular disease in epidemiological studies. However, this association failed to satisfy the Koch's postulates of causation with multiple clinical trials demonstrating inefficacy of anti-infective therapies in mitigating atherosclerotic cardiovascular events. Identification of underlying pathophysiological mechanisms and experience with vaccination against various infectious agents has ushered a new avenue of efforts in the development of an anti-atherosclerotic vaccine. Studies in animal models have identified various innate and adaptive immune pathways in atherosclerosis. In this review, we discuss the patho-biological link between chronic infections and atherosclerosis, evaluate existing evidence of animal and human trials on the association between infections and cardiovascular disease and introduce the concept of an anti-atherosclerotic vaccine
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An Antimicrobial Peptidomimetic Induces Mucorales Cell Death through Mitochondria-Mediated Apoptosis
The incidence of mucormycosis has dramatically increased in immunocompromised patients. Moreover, the array of cellular targets whose inhibition results in fungal cell death is rather limited. Mitochondria have been mechanistically identified as central regulators of detoxification and virulence in fungi. Our group has previously designed and developed a proteolytically-resistant peptidomimetic motif D(KLAKLAK)2 with pleiotropic action ranging from targeted (i.e., ligand-directed) activity against cancer and obesity to non-targeted activity against antibiotic resistant gram-negative rods. Here we evaluated whether this non-targeted peptidomimetic motif is active against Mucorales. We show that D(KLAKLAK)2 has marked fungicidal action, inhibits germination, and reduces hyphal viability. We have also observed cellular changes characteristic of apoptosis in D(KLAKLAK)2-treated Mucorales cells. Moreover, the fungicidal activity was directly correlated with vacuolar injury, mitochondrial swelling and mitochondrial membrane depolarization, intracellular reactive oxygen species accumulation (ROS), and increased caspase-like enzymatic activity. Finally, these apoptotic features were prevented by the addition of the ROS scavenger N-acetyl-cysteine indicating mechanistic pathway specificity. Together, these findings indicate that D(KLAKLAK)2 makes Mucorales exquisitely susceptible via mitochondrial injury-induced apoptosis. This prototype may serve as a candidate drug for the development of translational applications against mucormycosis and perhaps other fungal infections
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