Micromagnetic modelling of thin film media

The magnetic recording industry is continuously trying to increase the density of recording media. There is a continuous need, therefore, to fully understand the magnetic processes that occur in such media. To enable this understanding, theoretical studies are conducted in the form of micromagnetic modelling. This thesis is concerned with the micromagnetic modelling of thin film media. Experiments have shown that thin film media consists of closely packed, irregularly shaped grains with non-magnetic boundaries. To simulate a model of the physical structure, the Voronoi Construction Technique was implemented to give the required irregular structure. The grains were assumed to have uniaxial anisotropy and the magnetisation within the grain was assumed to vary throughout. To achieve non-uniformity, the grains were divided into triangles and the magnetisation within each triangle was assumed to vary linearly. The effect on the magnetisation within the grains due to the influences from an externally applied field, an anisotropy field, a magnetostatic field and an exchange field was observed. The motion of the magnetic moments under these influences was modelled by the Landau-Lifshitz equation. The most time consuming calculation in the modelling process is the magnetostatic field calculation. Therefore, continuous research into more efficient methods of calculating this field is carried out. The model initially uses a dipole approximation to calculate the total contribution from the magnetostatic field. A more accurate magnetostatic calculation, based on volume and surface charges of the triangles, was implemented to calculate the close range magnetostatic effects. The integrals were found to have singularities when the point of evaluation lay on one of the vertices of a triangle to be integrated. The Shift Method was introduced to overcome the problem which translated the problem vertex slightly away from the point of evaluation. Vast differences in the hysteresis loops when using the two methods of calculating the magnetostatic field were seen. The dipole approximation appeared to be too inaccurate in calculating the magnetostatic field. With the introduction of the more accurate method, the model compared well against previous findings

APPLICATION OF INQUIRY BASED LEARNING MODEL USING STEM APPROACH TO REDUCE STUDENTS' INTRINSIC COGNITIVE LOAD

This study is an experimental research using a quasi-experimental design with the type of non-equivalent control group pretest-posttest. This research aims to reduce Intrinsic Cognitive Load (ICL) through Inquiry Based Learning (IBL) model based STEM approach. This research was conducted at SMA Negeri 1 Seputih Banyak with the research subjects of class X IPA 1 students and X IPA 4. An data Intrinsic Cognitive Load obtained from essay the pretest-posttest (Task Complexity worksheet). Cognitive load test data analysis was performed using the data normality test, N-gain test and hypothesis test using the Paired Sample T-Test. The experimental class implements the Inquiry Based Learning model based audio and visual using STEM approach while the control class is nonaudio and visual. The results showed by the average value of N-Gain Intrinsic Cognitive Load (ICL) in the experimental class was 0.63 with the moderate category and the control class was 0.18 with the low category. Based on data analysis, can be concluded that there is a positive influence in the form of a decrease in the cognitive load Intrinsic Cognitive Load (ICL) in the experimental class using the Inquiry Based Learning model plus an audio and visual based  STEM approach

Effectiveness of various botanical traps against apple snail, Pomacea maculata (Gastropoda: Ampullariidae) in a rice field

The adverse effects of molluscicides applied for the control of the invasive apple snails, Pomacea spp., have led to the search for eco-based cultural, mechanical and biological control techniques. Therefore, a field study on the relative effectiveness of locally available and cost effective plant-based traps against Pomacea spp. was conducted. Results showed jackfruit skin (9.03 ± 0.60/m2 and 6.03 ± 0.60/m2) and damaged pomelo (9.00 ± 0.61/m2 and 5.78 ± 0.74/m2) were relatively more effective than tapioca leaves, water spinach leaves and old newspaper. Snails also displayed preference for fresh materials as compared to rotten materials. Thus, incorporating these findings in rice fields during early susceptible growth will ease the collection and destruction of snails

FACTORS AFFECTING METFORMIN AND CLOMIPHENE’S REPRODUCTIVE EFFICACY IN PCOS WOMEN

Polycystic Ovarian Syndrome (PCOS) is a heterogeneous multifactorial disorder in which the ovarian dysfunction is the main cause of an ovulatory infertility. Metformin and Clomiphene Citrate (CC) are two effective drugs to induce ovulation in these patients. The study aimed to ascertain the effect of obesity, serum insulin and free testosterone levels on fertility success with metformin and CC as first line approaches in PCOS. This clinical study was a retrospective multicenter cohort study conducted in nine gynecology and endocrinology clinics. It included (61) PCOS women, aged (18-32) years, having desire to conceive, and free from the study medications for more than six months. Patients were divided to metformin receiving and CC receiving groups. Main outcomes of measure were; pregnancy rate, and improvement in PCOS as detected by ultrasound on their second visit. Results showed that CC was more effective in non-obese users (P0.05). Overall improvement was affected by Serum Free Testosterone (SFT) in both study groups (P\u3e0.05). Metformin was effective regardless of patient’s SFT levels, while CC was effective in patients with high SFT levels. There was a significant association between obesity and pregnancy rate in metformin users (P0.05). However, CC was less effective than metformin in overall improvement (OR=0.53, P\u3e0.05,) suggesting metformin as the possible drug of choice regardless to obesity, serum insulin and SFT levels

Self-Expandable Metal Stenting of Refractory Upper Gut Corrosive Strictures: A New Role for Endoscopy?

Caustic strictures of the gastrointestinal tract are often difficult to treat, since relapses are frequent after medical or endoscopic treatment. Thus, novel approaches are needed. We report here our experience with self-expandable metallic stents (SEMS) as a new endoscopic approach in three patients with corrosive strictures of the upper gastrointestinal tract

Population fluctuation and dispersion patterns of apple snails, Pomacea spp. (Gastropoda: Ampullariidae) in a rice ecosystem

A field study was conducted for two consecutive rice-growing seasons from August, 2013 to May, 2014 to understand the population dynamics of exotic apple snails, Pomacea spp. (Ampullariidae), as affected by ambient weather and aquatic weeds. A one-acre rice field was divided into four blocks and eight samples per block were taken using a 0.5x0.5m quadrat. Collected snails were recorded as numbers of egg clutches, juveniles, adult females and males. Average rainfall, relative humidity, temperature and water pH, along with number of aquatic weeds and seedlings, were also recorded. Results confirmed the presence of only Pomacea maculata. The numbers of egg clutches, juveniles and adults were relatively high during the off-season as compared to the main-season. Meanwhile, relative humidity had a significant effect on the number of egg clutches, and rainfall affected the densities of juveniles and adults. Among the weeds, Limnocharis flava (Alismataceae) had significant effect on the densities of different snail stages. Different stages showed uniform dispersion pattern during both seasons due presumably to continuous availability of water and abundant food. Thus, results obtained could be helpful in understanding the population dynamics of P. maculata and devising appropriate management strategy

Effect of Alcohol and Nicotine on Fertility of Male Albino Mice

Abuse of recreational drugs such as alcohol and nicotine may be genotoxic and may have detrimental effect on the male fertility which was aimed to be investigated through this present study using mice model systems. A total of 60 mice were divided into three groups, viz.; control group (n=20), and two groups of alcohol treated (n=20) and nicotine treated mice groups (n=20), administered in recommended dose amount for 90 days. Representative numbers of mice were sacrificed on 10th, 30th and 90th day from each group and the testes were collected. DNA and RNA was extracted from the collected tissue following standard protocol; followed by RAPD-PCR and Real time PCR based analysis of extracted DNA and cDNA, prepared from isolated RNA, for Rbmy1 gene expression analysis, respectively. ?-actin was used as internal normalization control for Real time PCR analysis. Remarkable changes were observed in the RAPD profiles, based on difference in band pattern profile as observed in alcohol treated and nicotine induced cases compared to controls; thereby clearly indicating the effect of recreational drug on the genome of the host in comparison to untreated controls. The differential expression profile of Rbmy1 mRNA in the nicotine model, showed significant down regulation compared to control (p=0.045), and non-significant when compared to alcoholic model cohorts (p=0.307).The observation also showed differences of Rbmy1 mRNA expression in alcoholic cases compared to controls (p=0.782). The present study indicates that consumption of recreation drugs such as nicotine may play an important role in disturbing the genome integrity and expression of key gene associated with male fertility, thereby disposing to male infertility

Interleukin-18 induces angiogenic factors in rheumatoid arthritis synovial tissue fibroblasts via distinct signaling pathways

Objective Interleukin-18 (IL-18) is a proinflammatory cytokine implicated in the pathogenesis of rheumatoid arthritis (RA). This study was undertaken to examine the role of IL-18 in up-regulating secretion of the angiogenic factors stromal cell–derived factor 1Α (SDF-1Α)/CXCL12, monocyte chemoattractant protein 1 (MCP-1)/CCL2, and vascular endothelial growth factor (VEGF) in RA synovial tissue (ST) fibroblasts, and the underlying signaling mechanisms involved. Methods We used enzyme-linked immunosorbent assays, Western blotting, and chemical inhibitors/antisense oligodeoxynucleotides to signaling intermediates to assess the role of IL-18. Results IL-18 significantly enhanced the production of SDF-1Α/CXCL12, MCP-1/CCL2, and VEGF in RA ST fibroblasts, in a time- and concentration-dependent manner. IL-18–induced SDF-1Α/CXCL12 up-regulation was dependent on JNK, p38 MAPK, phosphatidylinositol 3-kinase (PI3K), and NFΚB. While IL-18–induced production of SDF-1Α/CXCL12 was also dependent on protein kinase CΔ (PKCΔ), production of MCP-1/CCL2 was dependent on PKCΑ, not PKCΔ. Additionally, RA ST fibroblast IL-18–induced MCP-1/CCL2 production was mediated by JNK, PI3K, and NFΚB. In contrast, IL-18 did not induce secretion of RA ST fibroblast MCP-1/CCL2 or VEGF via p38 MAPK. IL-18–induced RA ST fibroblast production of VEGF was mediated mainly by JNK-2, PKCΑ, and NFΚB. IL-18 induced phosphorylation of JNK, PKCΔ, p38 MAPK, and activating transcription factor 2 (ATF-2) in RA ST fibroblasts in a time-dependent manner, with JNK-2 being upstream of PKCΔ, ATF-2, and NFΚB. Conclusion These data support the notion that IL-18 has a unique role in inducing the secretion of angiogenic SDF-1Α/CXCL12, MCP-1/CCL2, and VEGF in RA ST fibroblasts, via distinct signaling intermediates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56041/1/22705_ftp.pd

Enteric infection coupled with chronic Notch pathway inhibition alters colonic mucus composition leading to dysbiosis, barrier disruption and colitis

Intestinal mucus layer disruption and gut microflora modification in conjunction with tight junction (TJ) changes can increase colonic permeability that allows bacterial dissemination and intestinal and systemic disease. We showed previously that Citrobacter rodentium (CR)-induced colonic crypt hyperplasia and/or colitis is regulated by a functional cross-talk between the Notch and Wnt/β-catenin pathways. In the current study, mucus analysis in the colons of CR-infected (108 CFUs) and Notch blocker Dibenzazepine (DBZ, i.p.; 10μmol/Kg b.w.)-treated mice revealed significant alterations in the composition of trace O-glycans and complex type and hybrid N-glycans, compared to CR-infected mice alone that preceded/ accompanied alterations in 16S rDNA microbial community structure and elevated EUB338 staining. While mucin-degrading bacterium, Akkermansia muciniphila (A. muciniphila) along with Enterobacteriaceae belonging to Proteobacteria phyla increased in the feces, antimicrobial peptides Angiogenin-4, Intelectin-1 and Intelectin-2, and ISC marker Dclk1, exhibited dramatic decreases in the colons of CR-infected/DBZ-treated mice. Also evident was a loss of TJ and adherens junction protein immuno-staining within the colonic crypts that negatively impacted paracellular barrier. These changes coincided with the loss of Notch signaling and exacerbation of mucosal injury. In response to a cocktail of antibiotics (Metronidazole/ ciprofloxacin) for 10 days, there was increased survival that coincided with: i) decreased levels of Proteobacteria, ii) elevated Dclk1 levels in the crypt and, iii) reduced paracellular permeability. Thus, enteric infections that interfere with Notch activity may promote mucosal dysbiosis that is preceded by changes in mucus composition. Controlled use of antibiotics seems to alleviate gut dysbiosis but may be insufficient to promote colonic crypt regeneration.R01-CA18532

Proteomic diversification of spermatostyles among six species of whirligig beetles

Seminal fluid protein composition is complex and commonly assumed to be rapidly divergent due to functional interactions with both sperm and the female reproductive tract (FRT), both of which evolve rapidly. In addition to sperm, seminal fluid may contain structures, such as mating plugs and spermatophores. Here, we investigate the evolutionary diversification of a lesser-known ejaculate structure: the spermatostyle, which has independently arisen in several families of beetles and true bugs. We characterized the spermatostyle proteome, in addition to spermatostyle and FRT morphology, in six species of whirligig beetles (family Gyrinidae). Spermatostyles were enriched for proteolytic enzymes, and assays confirmed they possess proteolytic activity. Sperm-leucylaminopeptidases (S-LAPs) were particularly abundant, and their localization to spermatostyles was confirmed by immunohistochemistry. Although there was evidence for functional conservation of spermatostyle proteomes across species, phylogenetic regressions suggest evolutionary covariation between protein composition and the morphology of both spermatostyles and FRTs. We postulate that S-LAPs (and other proteases) have evolved a novel structural role in spermatostyles and discuss spermatostyles as adaptations for delivering male-derived materials to females.Whirligig beetle sperm travel cooperatively through the female reproductive tract attached to a spermatostyle, a poorly studied rod-like structure. Proteome characterization revealed that spermatostyles are comprised of a restricted set of proteases and possess catalytic activity. Spermatostyle composition was also found to codiversify with spermatostyle length and female tract morphology. imag