Verifications Of The Kalman Conjecture For Irrational Transfer Functions

The sufficient conditions for the Kalman conjecture to be satisfied given by Fannin and Rushing [1] are relaxed in such a way as to allow their approach to be applied to irrational transfer functions. Specific results for a class of systems containing transportation lag are presented. © 1975, IEEE. All rights reserved

Notes on the precipitation of gold from cyanide solution

This work was to determine the Potassium Cyanide and the Zinc consumed in the precipitation of Gold from cyanide solutions by zinc dust --page 1

Social structure and the maintenance of biodiversity

Traditional ecological models assume well-mixed populations, where all members are equally likely to interact with one another. These models have been used successfully to explain competitive interactions; however, positive interactions such as intraspecific cooperation and interspecific facilitation cannot readily be captured. Previous work has highlighted the importance of spatial structure in explaining these behaviors as well as its role in maintaining biodiversity. These spatial structures have frequently been modeled using lattices, where all organisms have an equal number of interactions. Although these models capture the spatiality of interactions, natural populations are unlikely to follow such rigid patterns. There has been little work investigating the dynamics of populations with levels of social interactions that occur between these two extremes. In this work, we investigate the dynamics of a 3-strategy nontransitive system in populations with different social structures. We first describe how extending the neighborhood of interactions in traditional lattice models diminishes a population’s ability to maintain diversity. Populations are then moved to graphs where interactions are limited to cells within a defined distance of each other in Cartesian space. This method allows for a more fine-grained examination of the effects that increasing interactions have on maintaining diversity. Finally, we examine small world topologies and find that the introduction of random edges into the graph quickly disrupts the maintenance of diversity

NASA Light-Emitting Diodes for the Prevention of Oral Mucositis in Pediatric Bone Marrow Transplant Patients

Objective: The purpose of this study was to determine the effects of prophylactic near-infrared light therapy from light-emitting diodes (LEDs) in pediatric bone marrow transplant (BMT) recipients. Background Data: Oral mucositis (OM) is a frequent side effect of chemotherapy that leads to increased morbidity. Near-infrared light has been shown to produce biostimulatory effects in tissues, and previous results using nearinfrared lasers have shown improvement in OM indices. However, LEDs may hold greater potential for clinical applications. Materials and Methods: We recruited 32 consecutive pediatric patients undergoing myeloablative therapy in preparation for BMT. Patients were examined by two of three pediatric dentists trained in assessing the Schubert oral mucositis index (OMI) for left and right buccal and lateral tongue mucosal surfaces, while the patients were asked to rate their current left and right mouth pain, left and right xerostomia, and throat pain. LED therapy consisted of daily treatment at a fluence of 4 J/cm2 using a 670-nm LED array held to the left extraoral epithelium starting on the day of transplant, with a concurrent sham treatment on the right. Patients were assessed before BMT and every 2–3 days through posttransplant day 14. Outcomes included the percentage of patients with ulcerative oral mucositis (UOM) compared to historical epidemiological controls, the comparison of left and right buccal pain to throat pain, and the comparison between sides of the buccal and lateral tongue OMI and buccal pain. Results: The incidence of UOM was 53%, compared to an expected rate of 70–90%. There was also a 48% and 39% reduction of treated left and right buccal pain, respectively, compared to untreated throat pain at about posttransplant day 7 (p \u3c 0.05). There were no significant differences between sides in OMI or pain. Conclusion: Although more studies are needed, LED therapy appears useful in the prevention of OM in pediatric BMT patients

Ultrasensitive detection of lipoarabinomannan with plasmonic grating biosensors in clinical samples of HIV negative patients with tuberculosis.

BACKGROUND:Timely diagnosis of tuberculosis disease is critical for positive patient outcomes, yet potentially millions go undiagnosed or unreported each year. Sputum is widely used as the testing input, but limited by its complexity, heterogeneity, and sourcing problems. Finding methods to interrogate noninvasive, non-sputum clinical specimens is indispensable to improving access to tuberculosis diagnosis and care. In this work, economical plasmonic gratings were used to analyze tuberculosis biomarker lipoarabinomannan (LAM) from clinical urine samples by single molecule fluorescence assay (FLISA) and compared with gold standard sputum GeneXpert MTB/ RIF, culture, and reference ELISA testing results. METHODS AND FINDINGS:In this study, twenty sputum and urine sample sets were selected retrospectively from a repository of HIV-negative patient samples collected before initiation of anti-tuberculosis therapy. GeneXpert MTB/RIF and culture testing of patient sputum confirmed the presence or absence of pulmonary tuberculosis while all patient urines were reference ELISA LAM-negative. Plasmonic gratings produced by low-cost soft lithography were bound with anti-LAM capture antibody, incubated with patient urine samples, and biotinylated detection antibody. Fluorescently labeled streptavidin revealed single molecule emission by epifluorescence microscope. Using a 1 fg/mL baseline for limit of detection, single molecule FLISA demonstrated good qualitative agreement with gold standard tests on 19 of 20 patients, including accurately predicting the gold-standard-negative patients, while one gold-standard-positive patient produced no observable LAM in urine. CONCLUSIONS:Single molecule FLISA by plasmonic grating demonstrated the ability to quantify tuberculosis LAM from complex urine samples of patients from a high endemic setting with negligible interference from the complex media itself. Moreover, agreement with patient diagnoses by gold standard testing suggests that single molecule FLISA could be used as a highly sensitive test to diagnose tuberculosis noninvasively

Modeling the evolutionary dynamics of plasmids in spatial populations

One of the processes by which microorganisms are able to rapidly adapt to changing conditions is horizontal gene trans-fer, whereby an organism incorporates additional genetic material from sources other than its parent. These genetic elements may encode a wide variety of beneficial traits. Un-der certain conditions, many computational models capture the evolutionary dynamics of adaptive behaviors such as toxin production, quorum sensing, and biofilm formation, and have even provided new insights into otherwise unknown or misunderstood phenomena. However, such models rarely incorporate horizontal gene transfer, so they may be inca-pable of fully representing the vast repertoire of behaviors exhibited by natural populations. Although models of hori-zontal gene transfer exist, they rarely account for the spatial structure of populations, which is often critical to adaptive behaviors. In this work we develop a spatial model to examine how conjugation, one mechanism of horizontal gene transfer, can be maintained in populations. We investigate how both the costs of transfer and the benefits conferred affect evolution-ary outcomes. Further, we examine how rates of transmis-sion evolve, allowing this system to adapt to different en-vironments. Through spatial models such as these, we can gain a greater understanding of the conditions under which horizontally-acquired behaviors are evolved and are main-tained

Selenium, Folate, and Colon Cancer

Selenium is an essential trace element which has been implicated in cancer risk; however, study results have been inconsistent with regard to colon cancer. Our objectives were to 1) investigate the association between selenium and colon cancer 2) evaluate possible effect measure modifiers and 3) evaluate potential biases associated with the use of post-diagnostic serum selenium measure

12-Month outcomes of transcatheter tricuspid valve repair with the PASCAL system for severe tricuspid regurgitation

Objectives We investigated the durability of tricuspid regurgitation (TR) reduction and the clinical outcomes through 12 months after transcatheter tricuspid valve repair (TTVr) with the PASCAL Transcatheter Valve Repair System. Background TTVr has rapidly developed and demonstrated favorable acute outcomes, but longer follow-up data are needed. Methods Overall, 30 patients (age 77 ± 6 years; 57% female) received PASCAL implantation from September 2017 to May 2019 and completed a clinical follow-up at 12 months. Results The TR etiology was functional in 25 patients (83%), degenerative in three (10%), and mixed in two (7%). All patients had TR severe or greater (massive or torrential in 80%) and heart failure symptoms (90% in NYHA III or IV) under optimal medical treatment. Single-leaflet device attachment occurred in two patients. Moderate or less TR was achieved in 23/28 patients (82%) at 30 days, which was sustained at 12 months (86%). Two patients underwent repeat TTVr due to residual torrential TR (day 173) and recurrence of severe TR (day 280), respectively. One-year survival rate was 93%; 6 patients required rehospitalization due to acute heart failure. NYHA functional class I or II was achieved in 90% and 6-minute walk distance improved from 275 ± 122 m at baseline to 347 ± 112 m at 12-month (+72 ± 82 m, p < .01). There was no stroke, endocarditis, or device embolization during the follow-up. Conclusions Twelve-month outcomes from this multicenter compassionate use experience with the PASCAL System demonstrated high procedural success, acceptable safety, and significant clinical improvement

Compositional Features of HDL Particles Interact with Albuminuria to Modulate Cardiovascular Disease Risk

Lipoproteins containing apolipoprotein B modify associations of elevated urinary albumin excretion (UAE) with cardiovascular disease (CVD). Additionally, it is known that elevated UAE alters high-density lipoprotein functionality. Accordingly, we examined whether HDL features might also modify UAE-associated CVD. Multivariable Cox proportional-hazards modeling was performed on participants of the PREVEND (Prevention of Renal and Vascular Endstage Disease) study at the baseline screening with standard lipid/lipoprotein analyses and, three-to-four years later (second screen), with nuclear magnetic resonance lipoprotein analyses focusing on HDL parameters including HDL particle (HDL-P) and apolipoprotein A-I concentrations. These were used with UAE and derived measures of HDL apoA-I content (apoA-I/HDL-C and apoA-I/HDL-P) in risk models adjusted for gender, age, apoB, diabetes, past CVD history, CRP and GFR. Interaction analysis was also performed. Baseline screening revealed significant associations inverse for HDL-C and apoA-I and direct for apoA-I/HDL-C. The second screening demonstrated associations inverse for HDL-P, large HDL-P, medium HDL-P, HDL size, and apoA-I/HDL-P. Significant interactions with UAE included apoA-I/HDL-C at the baseline screening, and apoA-I/HDL-P and medium HDL-P but not apoA-I/HDL-C at the second screening. We conclude that features of HDL particles including apoA-I/HDL-P, indicative of HDL apoA-I content, and medium HDL-P modify associations of elevated UAE with CVD risk