Novi zakoni adaptivnog upravljanja referentnim modelom zasnovani na nekvadratnoj Ljapunovljevoj funkciji

In the design of model reference adaptive control (MRAC) schemes, adaptive laws have been developed based on Lyapunov stability theory. Over the past few decades, it has been a common practice to use Quadratic Lyapunov Functions (QLF). In contrast to such development, using a new Non-Quadratic Lyapunov Function (NQLF), this paper presents new adaptive laws for the MRAC. These new laws have the same advantage of assurance of stability of the overall system, as the earlier adaptive laws developed using the QLF. Over and above, they have an additional advantage of improved performance: in fact, the use of NQLF improved the system output error signal converging to zero. Finally, this paper also presents simulation results supporting the arguments.Za projektiranje sustava adaptivnog upravljanja referentnim modelom (MRAC) razvijeni su adaptivni zakoni koji se zasnivaju na Ljapunovljevoj teoriji stabilnosti. U zadnjih se nekoliko desetljeća uobičajeno koristi kvadratna Ljapunovljeva funkcija (QLF). Suprotno tome, u ovome se radu zakoni upravljanja referentnim modelom izvode na osnovi nove nekvadratne Ljapunovljeve funkcije (NQLF). Za izvedene je nove zakone upravljanja cjelokupni sustav stabilan, kao i kod prijašnjih zakona adaptivnog upravljanja kvadratnom Ljapunovljevom funkcijom. Povrh toga predloženim novim zakonima upravljanja NQLF funkcijom poboljšava se konvergencija izlaznog signala pogreške prema nuli. Na kraju su u radu predstavljeni rezultati simulacija koji podupiru navedene tvrdnje

Passive smoking in the etiology of non-syndromic orofacial clefts:a systematic review and meta-analysis

Background Studies have found a consistent positive association between maternal smoking and nonsyndromic orofacial clefts (NSOFC). However, no comprehensive assessment of the association between NSOFC and passive smoking has been undertaken. This systematic review and meta-analysis explores the relationship between maternal passive smoking and NSOFC, and compares the associations between passive and active smoking. Methods and Findings Search strategy, inclusion / exclusion criteria, and data extraction from studies reporting maternal passive smoking and NSOFC was implemented without language restrictions. Risks of bias in the identified studies were assessed and this information was used in sensitivity analyses to explain heterogeneity. Meta-analysis and meta-regression of the extracted data were performed. Egger's test was used to test for small study effects. Fourteen eligible articles were identified. Maternal passive smoking exposure was associated with a twofold increase in risk of NSOFC (odds ratio: 2.11, 95% confidence interval: 1.54-2.89); this was apparent for both cleft lip with and without palate (OR: 2.05, 95% CI: 1.27-3.3) and cleft palate (OR: 2.11, 95% CI: 1.23-3.62). There was substantial heterogeneity between studies. In the studies that provided data enabling crude and adjusted odd ratios to be compared, adjustment for potential confounders attenuated the magnitude of association to about a 1.5-fold increase in risk. Conclusion Overall, maternal passive smoking exposure results in a 1.5 fold increase in risk of NSOFC, similar to the magnitude of risk reported for active smoking, but there is marked heterogeneity between studies. This heterogeneity is not explained by differences in the distribution of cleft types, adjustment for covariates, broad geographic region, or study bias/quality. This thorough meta-analysis provides further evidence to minimize exposure to environmental tobacco smoke in policy making fora and in health promotion initiatives.</p

Oscillation of Second-Order Nonlinear Delay Dynamic Equations with Damping on Time Scales

We use the generalized Riccati transformation and the inequality technique to establish some new oscillation criteria for the second-order nonlinear delay dynamic equation with damping on a time scale T(r(t)g(x(t), xΔ(t)))Δ+p(t)g(x(t), xΔ(t))  + q(t)f(x(τ(t)))=0, where r(t), p(t), and q(t) are positive right dense continuous (rd-continuous) functions on T. Our results improve and extend some results established by Zhang et al., 2011. Also, our results unify the oscillation of the second-order nonlinear delay differential equation with damping and the second-order nonlinear delay difference equation with damping. Finally, we give some examples to illustrate our main results

Oscillation of Second-Order Nonlinear Delay Dynamic Equations on Time Scales

In this work, we use the generalized Riccati transformation and the inequality technique to establish some new oscillation criteria for the second-order nonlinear delay dynamic equation (p(t)(xΔ(t))γ)Δ+q(t)f(x(τ(t)))=0, on a time scale , where γ is the quotient of odd positive integers and p(t) and q(t) are positive right-dense continuous (rd-continuous) functions on &#x1D54B;. Our results improve and extend some results established by Sun et al. 2009. Also our results unify the oscillation of the second-order nonlinear delay differential equation and the second-order nonlinear delay difference equation. Finally, we give some examples to illustrate our main results

Interval Oscillation Criteria for Forced Second-Order Nonlinear Delay Dynamic Equations with Damping and Oscillatory Potential on Time Scales

We are concerned with the interval oscillation of general type of forced second-order nonlinear dynamic equation with oscillatory potential of the form rtg1xt,xΔtΔ+p(t)g2(x(t),xΔ(t))xΔ(t)+q(t)f(x(τ(t)))=e(t), on a time scale T. We will use a unified approach on time scales and employ the Riccati technique to establish some oscillation criteria for this type of equations. Our results are more general and extend the oscillation criteria of Erbe et al. (2010). Also our results unify the oscillation of the forced second-order nonlinear delay differential equation and the forced second-order nonlinear delay difference equation. Finally, we give some examples to illustrate our results

β-Sitosterol Glucoside-Loaded Nanosystem Ameliorates Insulin Resistance and Oxidative Stress in Streptozotocin-Induced Diabetic Rats

β-Sitosterol glucoside (SG), isolated from Senecio petasitis (Family Asteraceae), was loaded in self-nanoemulsifying drug delivery systems (SEDDS) in a trial to enhance its solubility and biological effect. Various co-surfactants were tested to prepare a successful SEDDS. The selected SG-loaded SEDDS had a droplet size of 134 ± 15.2 nm with a homogenous distribution (polydispersity index 0.296 ± 0.02). It also demonstrated a significant augmentation of SG in vitro release by 4-fold compared to the free drug suspension. The in vivo insulin sensitivity and antidiabetic effect of the prepared SG-loaded SEDDS were further assessed in streptozotocin-induced hyperglycemic rats. The hypoglycemic effect of SG-loaded nanosystem was evidenced by decreased serum glucose and insulin by 63.22% and 53.11%, respectively. Homeostasis model assessment-insulin resistance (HOMA-IR) index demonstrated a significant reduction by 5.4-fold in the diabetic group treated by SG-loaded nanosystem and exhibited reduced glucagon level by 40.85%. In addition, treatment with SG-loaded nanosystem significantly decreased serum MDA (malondialdehyde) and increased catalase levels by 38.31% and 64.45%, respectively. Histopathological investigations also supported the protective effect of SG-loaded nanosystem on the pancreas. The promising ability of SG-loaded nanosystem to ameliorate insulin resistance, protect against oxidative stress, and restore pancreatic β-cell secretory function warrants its inclusion in further studies during diabetes progression

Effects of short term feeding of some marine microalgae on the microbial profile associated with Dicentrarchus labrax post larvae

AbstractThis study investigates the microbial profile and antimicrobial activity of four marine microalgae species, Tetraselmis chuii, Nannochloropsis salina, Isochrysis galbana and Chlorella salina used in aquaculture of Dicentrarchus labrax in the post larval stage to estimate which was the best algal species that could be used as a green water technique and achieving the maximum rate of growth and survival of D. labrax post larvae. The results represented a significant increase in the length and width of D. labrax at p<0.05 recorded in the case of enrichment with I. galbana followed by N. salina, and the most weight was recorded in the case of N. salina as compared with the control. Significant increase in percentage of survival of D. labrax was recorded in the case of C. salina and T. chuii (70% and 60.1%, respectively) as compared with the control (22%). The antibacterial activity (AU) of the different microalgal ethanolic extracts against fish indicator pathogens was determined. The results indicated that the ethanolic extracts of C. salina and T. chuii have the most positive records against the fish indicator pathogens (Escherichia coli, Pseudomonas aeruginosa, Vibrio damsela, Vibrio fluvialis and Aeromonas hydrophila). The current study was extended to determine the GC–MS of ethanolic extract of C. salina and T. chuii. The main constituents detected in the ethanolic extract were organic acids like hexadecanoic acid, octadecanoic acid, and an acyclic diterpene alcohol like phytol

Trends and Decomposition Growth Analysis of the Most Important Cereal Crops in Egypt

This research aims to analyze the growth performance of the most important cereal crops of Egypt agriculture (wheat, rice, and maize) and the sources of the production growth of these crops during the period 1975-2017. This analysis is to implement appropriate policies that would enhance the production increase of these crops using component analysis. Based on the results of the Chow Breakpoint test, the study was divided into three periods: 1975-1986, 1987-2000 and 2001-2017, in addition to the full period 1975-2017.The results showed that the growth of wheat, rice and maize production during the study periods depends on changes in yield more than changes in area. So, the study emphasizes that the vertical expansion has a greater impact than the horizontal expansion. This is reflecting the effect of scientific research and development (R&D) on increasing cereal crops in Egypt