1,964 research outputs found
Deep swarm: Nested particle swarm optimization
A new generation of particle swarm optimization (PSO) has been developed that automatically evolves optimal or near-optimal values for parameters of the PSO algorithm such as population size and neighborhood size, and, if used, parameters of associated neural network(s), such as number of hidden processing elements (PEs). Called Deep Swarm, it is a nested version of PSO, and comprises swarms within a swarm
Extracorporeal Shockwave Therapy compared to Standard Care for Diabetic Foot Ulcer Healing: An Updated Systematic Review
Emerging evidence suggests that extracorporeal shockwave therapy (ESWT) may improve time to DFU healing. The aim of this review was to appraise the evidence on role of ESWT in DFU healing and impact of different ESWT doses. Databases were searched for trials comparing ESWT plus standard care to standard care alone in participants with DFUs. Search results were reviewed by two independent reviewers. The Cochrane Risk of Bias 2 tool and GRADE approach was used to assess bias and certainty. The primary outcome was time to healing. The search identified 345 papers after duplicates removed. Six trials consisting of471 participants were included. There was unclear or high risk of bias across all domains. Time to ulcer healing was probably shorter in patients treated with ESWT compared with standard ulcer care alone (GRADE: low certainty). Patients treated with ESWT were more likely to heal at 20 weeks post-ESWT compared with those treated with standard ulcer care alone (GRADE: low certainty). There was significant heterogeneity. ESWT remains a promising new treatment but the translation into routine clinical practice is still limited by the low certainty of evidence surrounding its effectiveness, case selection and optimum dose
Environmental DNA for the enumeration and management of Pacific salmon
Pacific salmon are a keystone resource in Alaska, generating annual revenues of well over ~US$500 million/yr. Due to their anadromous life history, adult spawners distribute amongst thousands of streams, posing a huge management challenge. Currently, spawners are enumerated at just a few streams because of reliance on human counters and, rarely, sonar. The ability to detect organisms by shed tissue (environmental DNA, eDNA) promises a more efficient counting method. However, although eDNA correlates generally with local fish abundances, we do not know if eDNA can accurately enumerate salmon. Here we show that daily, and near‐daily, flow‐corrected eDNA rate closely tracks daily numbers of returning sockeye and coho spawners and outmigrating sockeye smolts. eDNA thus promises accurate and efficient enumeration, but to deliver the most robust numbers will need higher‐resolution stream‐flow data, at‐least‐daily sampling, and a focus on species with simple life histories, since shedding rate varies amongst jacks, juveniles, and adults
Using Empirical Phase Diagrams to Understand the Role of Intramolecular Dynamics in Immunoglobulin G Stability
Understanding the relationship between protein dynamics and stability is of paramount importance to the fields of biology and pharmaceutics. Clarifying this relationship is complicated by the large amount of experimental data that must be generated and analyzed if motions that exist over the wide range of timescales are to be included. To address this issue, we propose an approach that utilizes a multidimensional vector-based empirical phase diagram (EPD) to analyze a set of dynamic results acquired across a temperature-pH perturbation plane. This approach is applied to a humanized immunoglobulin G1 (IgG1), a protein of major biological and pharmaceutical importance whose dynamic nature is linked to its multiple biological roles. Static and dynamic measurements are used to characterize the IgG and to construct both static and dynamic empirical phase diagrams. Between pH 5 and 8, a single, pH-dependent transition is observed that corresponds to thermal unfolding of the IgG. Under more acidic conditions, evidence exists for the formation of a more compact, aggregation resistant state of the immunoglobulin, known as A-form. The dynamics-based EPD presents a considerably more detailed pattern of apparent phase transitions over the temperature-pH plane. The utility and potential applications of this approach are discussed
Vascular mitochondrial respiratory function: the impact of advancing age
Little is known about vascular mitochondrial respiratory function and the impact of age. Therefore, skeletal muscle feed arteries were harvested from young (33 ± 7 yr, n = 10), middle-aged (54 ± 5 yr, n = 10), and old (70 ± 7 yr, n = 10) subjects, and mitochondrial respiration as well as citrate synthase (CS) activity were assessed. Complex I (CI) and complex I + II (CI+II) state 3 respiration were greater in young (CI: 10.4 ± 0.8 pmol·s−1·mg−1 and CI+II: 12.4 ± 0.8 pmol·s−1·mg−1, P \u3c 0.05) than middle-aged (CI: 7 ± 0.6 pmol·s−1·mg−1 and CI+II: 8.3 ± 0.5 pmol·s−1·mg−1) and old (CI: 7.2 ± 0.4 pmol·s−1·mg−1 and CI+II: 7.6 ± 0.5 pmol·s−1·mg−1) subjects and, as in the case of complex II (CII) state 3 respiration, were inversely correlated with age [r = −0.56 (CI), r = −0.7 (CI+II), and r = 0.4 (CII), P \u3c 0.05]. In contrast, state 4 respiration and mitochondria-specific superoxide levels were not different across groups. The respiratory control ratio was greater in young (2.2 ± 0.2, P \u3c 0.05) than middle-aged and old (1.4 ± 0.1 and 1.1 ± 0.1, respectively) subjects and inversely correlated with age (r = −0.71, P \u3c 0.05). As CS activity was inversely correlated with age (r = −0.54, P \u3c 0.05), when normalized for mitochondrial content, the age-related differences and relationships with state 3 respiration were ablated. In contrast, mitochondrion-specific state 4 respiration was now lower in young (15 ± 1.4 pmol·s−1·mg−1·U CS−1, P \u3c 0.05) than middle-aged and old (23.4 ± 3.6 and 27.9 ± 3.4 pmol·s−1·mg−1·U CS−1, respectively) subjects and correlated with age (r = 0.46, P \u3c 0.05). Similarly, superoxide/CS levels were lower in young (0.07 ± 0.01) than old (0.19 ± 0.41) subjects and correlated with age (r = 0.44, P \u3c 0.05). Therefore, with aging, vascular mitochondrial respiratory function declines, predominantly as a consequence of falling mitochondrial content. However, per mitochondrion, aging likely results in greater mitochondrion-derived oxidative stress, which may contribute to age-related vascular dysfunction
Sensory Deprivation Alters Aggrecan and Perineuronal Net Expression in the Mouse Barrel Cortex
An important role for the neural extracellular matrix in modulating cortical activity-dependent synaptic plasticity has been established by a number of recent studies. However, identification of the critical molecular components of the neural matrix that mediate these processes is far from complete. Of particular interest is the perineuronal net (PN), an extracellular matrix component found surrounding the cell body and proximal neurites of a subset of neurons. Because of the apposition of thePNto synapses and expression of this structure coincident with the close of the critical period, it has been hypothesized that nets could play uniquely important roles in synapse stabilization and maturation. Interestingly, previous work has also shown that expression of PNs is dependent on appropriate sensory stimulation in the visual system. Here, we investigated whether PNs in the mouse barrel cortex are expressed in an activity-dependent manner by manipulating sensory input through whisker trimming. Importantly, this manipulation did not lead to a global loss of PNs but instead led to a specific decrease in PNs, detected with the antibody Cat-315, in layer IV of the barrel cortex. In addition, we identified a key activity-regulated component of PNs is the proteoglycan aggrecan. We also demonstrate that these Cat-315-positive neurons virtually all also express parvalbumin. Together, these data are in support of an important role for aggrecan in the activity-dependent formation of PNs on parvalbumin-expressing cells and suggest a role for expression of these nets in regulating the close of the critical period
Soluble Antigen Arrays for Selective Desensitization of Insulin-Reactive B Cells
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Molecular Pharmaceutics, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.molpharmaceut.8b01250.Autoimmune diseases are believed to be highly dependent on loss of immune tolerance to self-antigens. Currently, no treatments have been successful clinically in inducing autoantigen-specific tolerance, including efforts to utilize antigen-specific immunotherapy (ASIT) to selectively correct the aberrant autoimmunity. Soluble antigen arrays (SAgAs) represent a novel autoantigen delivery system composed of a linear polymer, hyaluronic acid (HA), displaying multiple copies of conjugated autoantigen. We have previously reported that Soluble Antigen Arrays proteolipid protein (SAgAPLP) induced tolerance to a specific multiple sclerosis (MS) autoantigen, proteolipid peptide (PLP). Utilizing SAgA technology, we have developed a new ASIT as a possible type 1 diabetes (T1D) therapeutic by conjugating human insulin to HA, known as Soluble Antigen Array Insulin (SAgAIns). Three types were synthesized: low valency lvSAgAIns (2 insulins per HA), medium valency mvSAgAIns (4 insulins per HA) and, high valency hvSAgAIns (9 insulins per HA) to determine if valency differentially modulates the ex vivo activity of insulin-binding B cells (IBCs). Extensive biophysical characterization was performed for the SAgA molecules. SAgAIns molecules were successfully used to affect the biologic activity of IBCs by inducing desensitization of the B cell antigen receptors (BCR). SAgAIns bound specifically to insulin-reactive B cells without blocking epitopes recognized by antibodies against the Fc regions of membrane immunoglobulin or CD79 transducer components of the BCR. Pre-incubation of IBCs (125Tg) with SAgAIns, but not HA alone, rendered the IBCs refractory to re-stimulation. SAgAIns induced a decrease in BCR expression and IP3R-mediated intracellular calcium release. Surprisingly, SAgAIns binding to BCR on the surface of IBCs induced the observed effects at both high and low SAgAIns valency. Future studies aim to test the effects of SAgAIns on disease progression in the VH125.NOD mouse model of T1D.NIH T32 GM00854
Vasodilatory and vascular mitochondrial respiratory function with advancing age: evidence of a free radically mediated link in the human vasculature
Recognizing the age-related decline in skeletal muscle feed artery (SMFA) vasodilatory function, this study examined the link between vasodilatory and mitochondrial respiratory function in the human vasculature. Twenty-four SMFAs were harvested from young (35 ± 6 yr, n = 9) and old (71 ± 9 yr, n = 15) subjects. Vasodilation in SMFAs was assessed, by pressure myography, in response to flow-induced shear stress, acetylcholine (ACh), and sodium nitroprusside (SNP) while mitochondrial respiration was measured, by respirometry, in permeabilized SMFAs. Endothelium-dependent vasodilation was significantly attenuated in the old, induced by both flow (young: 92 ± 3, old: 45 ± 4%) and ACh (young: 92 ± 3, old: 54 ± 5%), with no significant difference in endothelium-independent vasodilation. Complex I and I + II state 3 respiration was significantly lower in the old (CI young: 10.1 ± 0.8, old: 7.0 ± 0.4 pmol·s−1·mg−1; CI + II young: 12.3 ± 0.6, old: 7.6 ± 0.4 pmol·s−1·mg−1). The respiratory control ratio (RCR) was also significantly attenuated in the old (young: 2.2 ± 0.1, old: 1.1 ± 0.1). Furthermore, state 3 (CI + II) and 4 respiration, as well as RCR, were significantly correlated (r = 0.49–0.86) with endothelium-dependent, but not endothelium-independent, function. Finally, the direct intervention with mitochondrial-targeted antioxidant (MitoQ) significantly improved endothelium-dependent vasodilation in the old but not in the young. Thus, the age-related decline in vasodilatory function is linked to attenuated vascular mitochondrial respiratory function, likely by augmented free radicals
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