Multi-period Project Portfolio Selection under Risk considerations and Stochastic Income

This paper deals with multi-period project portfolio selection problem. In this problem, the available budget is invested on the best portfolio of projects in each period such that the net profit is maximized. We also consider more realistic assumptions to cover wider range of applications than those reported in previous studies. A novel mathematical model is presented to solve the problem, considering risks, stochastic incomes, and possibility of investing extra budget in each time period. Due to the complexity of the problem, an effective meta-heuristic method hybridized with a local search procedure is presented to solve the problem. The algorithm is based on genetic algorithm (GA), which is a prominent method to solve this type of problems. The GA is enhanced by a new solution representation and well selected operators. It also is hybridized with a local search mechanism to gain better solution in shorter time. The performance of the proposed algorithm is then compared with well-known algorithms, like basic genetic algorithm (GA), particle swarm optimization (PSO), and electromagnetism-like algorithm (EM-like) by means of some prominent indicators. The computation results show the superiority of the proposed algorithm in terms of accuracy, robustness and computation time. At last, the proposed algorithm is wisely combined with PSO to improve the computing time considerably

High and Low Molecular Weight Hyaluronic Acid Differentially Regulate Human Fibrocyte Differentiation

Following tissue injury, monocytes can enter the tissue and differentiate into fibroblast-like cells called fibrocytes, but little is known about what regulates this differentiation. Extracellular matrix contains high molecular weight hyaluronic acid (HMWHA; ∼2×10(6) Da). During injury, HMWHA breaks down to low molecular weight hyaluronic acid (LMWHA; ∼0.8-8×10(5) Da).In this report, we show that HMWHA potentiates the differentiation of human monocytes into fibrocytes, while LMWHA inhibits fibrocyte differentiation. Digestion of HMWHA with hyaluronidase produces small hyaluronic acid fragments, and these fragments inhibit fibrocyte differentiation. Monocytes internalize HMWHA and LMWHA equally well, suggesting that the opposing effects on fibrocyte differentiation are not due to differential internalization of HMWHA or LMWHA. Adding HMWHA to PBMC does not appear to affect the levels of the hyaluronic acid receptor CD44, whereas adding LMWHA decreases CD44 levels. The addition of anti-CD44 antibodies potentiates fibrocyte differentiation, suggesting that CD44 mediates at least some of the effect of hyaluronic acid on fibrocyte differentiation. The fibrocyte differentiation-inhibiting factor serum amyloid P (SAP) inhibits HMWHA-induced fibrocyte differentiation and potentiates LMWHA-induced inhibition. Conversely, LMWHA inhibits the ability of HMWHA, interleukin-4 (IL-4), or interleukin-13 (IL-13) to promote fibrocyte differentiation.We hypothesize that hyaluronic acid signals at least in part through CD44 to regulate fibrocyte differentiation, with a dominance hierarchy of SAP>LMWHA≥HMWHA>IL-4 or IL-13

Apnea of prematurity: from cause to treatment

Apnea of prematurity (AOP) is a common problem affecting premature infants, likely secondary to a “physiologic” immaturity of respiratory control that may be exacerbated by neonatal disease. These include altered ventilatory responses to hypoxia, hypercapnia, and altered sleep states, while the roles of gastroesophageal reflux and anemia remain controversial. Standard clinical management of the obstructive subtype of AOP includes prone positioning and continuous positive or nasal intermittent positive pressure ventilation to prevent pharyngeal collapse and alveolar atelectasis, while methylxanthine therapy is a mainstay of treatment of central apnea by stimulating the central nervous system and respiratory muscle function. Other therapies, including kangaroo care, red blood cell transfusions, and CO2 inhalation, require further study. The physiology and pathophysiology behind AOP are discussed, including the laryngeal chemoreflex and sensitivity to inhibitory neurotransmitters, as are the mechanisms by which different therapies may work and the potential long-term neurodevelopmental consequences of AOP and its treatment

Identification of Markers that Distinguish Monocyte-Derived Fibrocytes from Monocytes, Macrophages, and Fibroblasts

The processes that drive fibrotic diseases are complex and include an influx of peripheral blood monocytes that can differentiate into fibroblast-like cells called fibrocytes. Monocytes can also differentiate into other cell types, such as tissue macrophages. The ability to discriminate between monocytes, macrophages, fibrocytes, and fibroblasts in fibrotic lesions could be beneficial in identifying therapies that target either stromal fibroblasts or fibrocytes. and in sections from human lung. We found that markers such as CD34, CD68, and collagen do not effectively discriminate between the four cell types. In addition, IL-4, IL-12, IL-13, IFN-γ, and SAP differentially regulate the expression of CD32, CD163, CD172a, and CD206 on both macrophages and fibrocytes. Finally, CD49c (α3 integrin) expression identifies a subset of fibrocytes, and this subset increases with time in culture.These results suggest that discrimination of monocytes, macrophages, fibrocytes, and fibroblasts in fibrotic lesions is possible, and this may allow for an assessment of fibrocytes in fibrotic diseases

Damping Loss Factor for Damping Materials for Continuous Structures

The half power bandwidth method is used for measuring a damping loss factor. There are different damping materials available of different configuration in the market. This paper will help to select damping materials for different applications and to give a data bank for numerical analysis. Other objectives are to observe damping loss factor at various condition which are as follows: (1) To compare the effect of fusing with base material. (2) To compare the effect of material thickness. (3) To compare damping materials with constraint layer damping (4) To evaluate the damping loss factor using double layers of constraint layer damping. INTORDUCTION The damping loss factor is a very important parameter in vibration engineering and it is very difficult to evaluate analytically. The damping loss factor is a measure of energy dissipation and it must be evaluated experimentally. There are three types of damping namely, dry or coulomb, viscous damping, and structural or hysteresis damping. Dry damping is constant in magnitude and opposes the motion. Viscous damping is proportional to velocity of th

Study of the Prevalence and Antimicrobial Susceptibility Patterns of Staphylococcus Aureus in Garhwal Region, India

Staphylococcus aureus is a ubiquitous commensal bacterium on human skins and anterior nares, but frequently causes severe infections in humans. It is commonest cause of infection in hospitals and is most liable to infect newborn babies, surgical patients, old and malnourished persons and patients with diabetes and other chronic diseases .Aim of this paper is to study the prevalence and detection of antimicrobial susceptibility patterns of Staphylococcus aureus at the Garhwal Region, India. Samples are collected from Veer Chandra Singh Government medical science and research institute HNB Base Hospital Srinagar Garhwal. Data obtained about the study subjects included basic demographics, reasons for admission, medical history(underlying diseases) , medication history, site of infection, culture site, social history and isolate characterization (e. g. antimicrobial susceptibility pattern results). P-value less than 0.05 were considered as statistically significant.During the two years period, 300 patients with clinical presentation of septicemia admitted in different units, namely Medicine, Nursery, Pediatrics, ICU, Orthopedic, Dialysis and Surgery, 309 of them were positive for S. aureus. The overall prevalence of S. aureus was 15.3% and the prevalence in the type of samples cultured were: blood (0.3%), followed by body fluids (12.4%), ear swabs (0.8%), FNAC (4.2%), PEDIA (3.5%), pleural fluid (4%), pus (0.8), pus aspirate (0.8), semen (28), sputum (0.8), urine (45.2%), vag (0.8%) and wound (2%). The sensitivity rates of the various antibiotics are as follows: ampicillin (16%), amoxicillin (39%), amikacin (86.3%), chiloroamhenicol (78.6%), cotrimoxazole (49.6%), cephoxitin/oxac (18.3%), ciprofloxacin (52.6%), eryhromycin (55.3%), gentamicin (70.6%), penicillin (5.3%), clindamycin (56.3%), rifampicin (38.4%), linezolid (41%), teicoplanin (46.3%) and vancomycin (48.6%). A total of 146 samples showed multi-resistance to antimicrobial antibiotics. Staphylococcus aureus isolates in this study showed higher multi-drug resistance patterns to several antimicrobials and thus further studies should be conducted in the hospital.</jats:p