333 research outputs found
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Global dynamics of a piece-wise epidemic model with switching vaccination strategy
A piece-wise epidemic model of a switching vaccination program, implemented once the number of people exposed to a disease-causing virus reaches a critical level, is proposed. In addition, variation or uncertainties in interventions are examined with a perturbed system version of the model. We also analyzed the global dynamic behaviors of both the original piece-wise system and the perturbed version theoretically, using generalized Jacobian theory, Lyapunov constants for a non-smooth vector field and a generalization of Dulac's criterion. The main results show that, as the critical value varies, there are three possibilities for stabilization of the piece-wise system: (i) at the disease-free equilibrium; (ii) at the endemic states for the two subsystems or (iii) at a generalized equilibrium which is a novel global attractor for non-smooth systems. The perturbed system exhibits new global attractors including a pseudo-focus of parabolic-parabolic (PP) type, a pseudo-equilibrium and a crossing cycle surrounding a sliding mode region. Our findings demonstrate that an infectious disease can be eradicated either by increasing the vaccination rate or by stabilizing the number of infected individuals at a previously given level, conditional upon a suitable critical level and the parameter values
Pengaruh Pemberian Kolkisin Terhadap Penampilan Fenotip Galur Inbrida Jagung Pakan (Zea Mays L.) Pada Fase Pertumbuhan Vegetatif
Potensi hasil pada tanaman di kendalikan oleh banyak gen (poligenik). Semakin banyak gen pada tanaman maka akan meningkatkan hasil produksi. Dosis gen dapat ditingkatkan atau diperbanyak dengan menggunakan kolkisin. Telah dilakukan penelitian tentang pengaruh pemberian kolkisin terhadap penampilan fenotip galur inbrida jagung pakan (Zea mays L.) pada fase pertumbuhan vegetatif. Penelitian ini dilaksanakan di Laboratorium Bioteknologi, Fakultas Pertanian, Universitas Brawijaya. Kedua galur jagung di tanam di desa Ampeldento, Karangploso, Malang. Penelitian menggunakan 2 galur (G1 dan G2) dan 3 taraf konsentrasi kolkisin (0 ppm, 400 ppm dan 600 ppm). Karakter kuantitatif yang diamati adalah jumlah tanaman yang tumbuh, tinggi tanaman, lingkar batang, jumlah daun, panjang daun, lebar daun, jumlah stomata, panjang stomata, lebar stomata, umur berbunga jantan dan umur berbunga betina. Sedangkan karakter kualitatif yang diamati adalah warna daun. Hasil penelitian menunjukan perlakuan kolkisin memberikan pengaruh yang nyata pada jumlah tanaman yang tumbuh, tinggi tanaman, lingkar batang, jumlah daun, jumlah stomata, panjang stomata, lebar stomata, umur berbunga jantan, umur berbunga betina dan warna daun. Hasil ini dapat dijadikan acuan awal bahwa perlakuan kolkisin diduga efektif mempengaruhi mutasi atau merubah ploidi jagung dan dilakukan pengamatan kromosom galur untuk memperjelas ploidi yang akan dilakukan pada penelitian selanjutnya
Change in bone mineral density in post menopausal women with rheumatoid arthritis
Introduction: Low bone mass is a serious complication of post menopausal women with rheumatoid arthritis. We determined the Change in Bone Mineral Density in postmenopausal women with rheumatoid arthritis. Methods: This retrospective cohort study was carried out on consecutive postmenopausal women with rheumatoid arthritis who were referred to the Azar 5th teaching hospital affiliated to Golestan University of Medical Sciences, North of Iran in 2009. The required data were gathered from the patients' medical records. The data were analyzed using SPSS software and statistical tests. Results: We studied 98 postmenopausal women with rheumatoid arthritis. Mean number of years since menopause and mean duration of disease were 9.39 and 5.13 respectively. T Score mean in femoral neck and lumbar spines was -1.45±1.26 and -2.45±1.44 respectively. The overall prevalence of osteoporosis at both the lumbar spine and femoral neck was 13.3. We have found a significant correlation between age, duration of disease, duration of menopause and bone mineral density (P-Value<0.01). Conlusion: Our results indicate a negative effect of age, number of years since menopause and duration of disease on bone mineral density. So, BMD should be measured in high risk women prior to the implementation of any treatment or prevention program
Rechargeable organicâair redox flow batteries
A rechargeable organicâair flow battery based on aqueous electrolytes is proposed and tests are conducted in a divided cell with a three-electrode configuration. Quinoxaline is used as the negative redox couple due to its low electrode potential of c.a. â0.9 V vs. Hg|HgO in aqueous electrolytes. High-surface-area nickel mesh and manganese-dioxide electrodes were employed for oxygen evolution and reduction, respectively, together with a low-cost hydroxide doped polybenzimidazole (m-PBI) separator (c.a. 20 ÎŒm). In typical alkaline electrolytes (2 M NaOH), the open-circuit voltage of the flow battery was c.a. 0.95 V, which is comparable to existing organic-based batteries. The average charge and discharge cell voltage ranges at 5â10 mA cmâ2 were 1.7â1.95 V and 0.4â0.7 V, respectively. Despite using low-cost materials, average coulombic and energy efficiencies of the batteries were c.a. 81 and 25%, respectively, at 7.5 mA cmâ2 over 20 cycles
The biochemical toxin arsenal from ant venoms
© 2016 by the authors; licensee MDPI, Basel, Switzerland. Ants (Formicidae) represent a taxonomically diverse group of hymenopterans with over 13,000 extant species, the majority of which inject or spray secretions from a venom gland. The evolutionary success of ants is mostly due to their unique eusociality that has permitted them to develop complex collaborative strategies, partly involving their venom secretions, to defend their nest against predators, microbial pathogens, ant competitors, and to hunt prey. Activities of ant venom include paralytic, cytolytic, haemolytic, allergenic, pro-inflammatory, insecticidal, antimicrobial, and pain-producing pharmacologic activities, while non-toxic functions include roles in chemical communication involving trail and sex pheromones, deterrents, and aggregators. While these diverse activities in ant venoms have until now been largely understudied due to the small venom yield from ants, modern analytical and venomic techniques are beginning to reveal the diversity of toxin structure and function. As such, ant venoms are distinct from other venomous animals, not only rich in linear, dimeric and disulfide-bonded peptides and bioactive proteins, but also other volatile and non-volatile compounds such as alkaloids and hydrocarbons. The present review details the unique structures and pharmacologies of known ant venom proteinaceous and alkaloidal toxins and their potential as a source of novel bioinsecticides and therapeutic agents
Managersâ perceptions of protected area outcomes in Madagascar highlight the need for species monitoring and knowledge transfer
NB! https://doi.org/10.1111/csp2.6 (right) Wrong doi reported in PDFConsiderable effort has gone into assessing the effectiveness of protected areas (PAs) in preventing biodiversity loss, and PA impacts on local communities. However, little is known about how pressures are being perceived and dealt with by local PA managers and what perceptions managers have of biodiversity trends and humanâinduced pressures in the PAs they manage. We surveyed and convened a workshop with PA managers in Madagascar asking about the impacts of PA establishment. The managers reported that PAs have been successful in reducing threats. However, managers lacked specific knowledge of trends in species abundance, reporting the need for more species monitoring and knowledge transfer from scientific researchers. We argue that greater collaboration and exchange of knowledge between researchers, managers, and local communities is necessary to ensure that PA effectiveness research is of practical value and contributes to improved PA outcomes.Considerable effort has gone into assessing the effectiveness of protected areas (PAs) in preventing biodiversity loss, and PA impacts on local communities. However, little is known about how pressures are being perceived and dealt with by local PA managers and what perceptions managers have of biodiversity trends and humanâinduced pressures in the PAs they manage. We surveyed and convened a workshop with PA managers in Madagascar asking about the impacts of PA establishment. The managers reported that PAs have been successful in reducing threats. However, managers lacked specific knowledge of trends in species abundance, reporting the need for more species monitoring and knowledge transfer from scientific researchers. We argue that greater collaboration and exchange of knowledge between researchers, managers, and local communities is necessary to ensure that PA effectiveness research is of practical value and contributes to improved PA outcomes.Considerable effort has gone into assessing the effectiveness of protected areas (PAs) in preventing biodiversity loss, and PA impacts on local communities. However, little is known about how pressures are being perceived and dealt with by local PA managers and what perceptions managers have of biodiversity trends and humanâinduced pressures in the PAs they manage. We surveyed and convened a workshop with PA managers in Madagascar asking about the impacts of PA establishment. The managers reported that PAs have been successful in reducing threats. However, managers lacked specific knowledge of trends in species abundance, reporting the need for more species monitoring and knowledge transfer from scientific researchers. We argue that greater collaboration and exchange of knowledge between researchers, managers, and local communities is necessary to ensure that PA effectiveness research is of practical value and contributes to improved PA outcomes.Peer reviewe
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3D printed ventricular septal defect patch: a primer for the 2015 Radiological Society of North America (RSNA) hands-on course in 3D printing.
Hand-held three dimensional models of the human anatomy and pathology, tailored-made protheses, and custom-designed implants can be derived from imaging modalities, most commonly Computed Tomography (CT). However, standard DICOM format images cannot be 3D printed; instead, additional image post-processing is required to transform the anatomy of interest into Standard Tessellation Language (STL) format is needed. This conversion, and the subsequent 3D printing of the STL file, requires a series of steps. Initial post-processing involves the segmentation-demarcation of the desired for 3D printing parts and creating of an initial STL file. Then, Computer Aided Design (CAD) software is used, particularly for wrapping, smoothing and trimming. Devices and implants that can also be 3D printed, can be designed using this software environment. The purpose of this article is to provide a tutorial on 3D Printing with the test case of complex congenital heart disease (CHD). While the infant was born with double outlet right ventricle (DORV), this hands-on guide to be featured at the 2015 annual meeting of the Radiological Society of North America Hands-on Course in 3D Printing focused on the additional finding of a ventricular septal defect (VSD). The process of segmenting the heart chambers and the great vessels will be followed by optimization of the model using CAD software. A virtual patch that accurately matches the patient's VSD will be designed and both models will be prepared for 3D printing
POSITION TRACKING CONTROL OF DC MOTOR FOR FRONT WHEEL SYSTEMS VIA HILS SIMULATION METHOD
This paper present about position tracking control of DC motor to be used as the actuator controller for the front wheel test rig system. The controller strategy that was developed is based on Proportional-Integral-Derivative (PID) controller. It consists of one single closed control loops namely position tracking control loop. To evaluate the effectiveness of the proposed controller, simulation and experimental studies were performed by using various input demand such as saw tooth, sine and step functions in 5°, 10°, 15° and 20° with the present of steering ratio at 360:20. The results, it is found that the trend between simulation and experimental data are similar with the command position with acceptable level of error which less than 10% for application at hand
Comparisons of Protein and Peptide Complexity in Poneroid and Formicoid Ant Venoms
© 2016 American Chemical Society. Animal venom peptides are currently being developed as novel drugs and bioinsecticides. Because ants use venoms for defense and predation, venomous ants represent an untapped source of potential bioactive toxins. This study compared the protein and peptide components of the poneroid ants Neoponera commutata, Neoponera apicalis, and Odontomachus hastatus and the formicoid ants Ectatomma tuberculatum, Ectatomma brunneum, and Myrmecia gulosa. 1D and 2D PAGE revealed venom proteins in the mass range 250 kDa. NanoLC-ESI-QTOF MS/MS analysis of tryptic peptides revealed the presence of common venom proteins and also many undescribed proteins. RP-HPLC separation followed by MALDI-TOF MS of the venom peptides also revealed considerable heterogeneity. It was found that the venoms contained between 144 and 1032 peptides with 5-95% of peptides in the ranges 1-4 and 1-8 kDa for poneroid and formicoid ants, respectively. By employing the reducing MALDI matrix 1,5-diaminonapthalene, up to 28 disulfide-bonded peptides were also identified in each of the venoms. In particular, the mass range of peptides from poneroid ants is lower than peptides from other venoms, indicating possible novel structures and pharmacologies. These results indicate that ant venoms represent an enormous, untapped source of novel therapeutic and bioinsecticide leads
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Plasma sTNFR1 and IL8 for prognostic enrichment in sepsis trials: a prospective cohort study.
BackgroundEnrichment strategies improve therapeutic targeting and trial efficiency, but enrichment factors for sepsis trials are lacking. We determined whether concentrations of soluble tumor necrosis factor receptor-1 (sTNFR1), interleukin-8 (IL8), and angiopoietin-2 (Ang2) could identify sepsis patients at higher mortality risk and serve as prognostic enrichment factors.MethodsIn a multicenter prospective cohort study of 400 critically ill septic patients, we derived and validated thresholds for each marker and expressed prognostic enrichment using risk differences (RD) of 30-day mortality as predictive values. We then used decision curve analysis to simulate the prognostic enrichment of each marker and compare different prognostic enrichment strategies.Measurements and main resultsAn admission sTNFR1 concentrationâ>â8861âpg/ml identified patients with increased mortality in both the derivation (RD 21.6%) and validation (RD 17.8%) populations. Among immunocompetent patients, an IL8 concentrationâ>â94âpg/ml identified patients with increased mortality in both the derivation (RD 17.7%) and validation (RD 27.0%) populations. An Ang2 levelâ>â9761âpg/ml identified patients at 21.3% and 12.3% increased risk of mortality in the derivation and validation populations, respectively. Using sTNFR1 or IL8 to select high-risk patients improved clinical trial power and efficiency compared to selecting patients with septic shock. Ang2 did not outperform septic shock as an enrichment factor.ConclusionsThresholds for sTNFR1 and IL8 consistently identified sepsis patients with higher mortality risk and may have utility for prognostic enrichment in sepsis trials
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