Heat Assisted Magnetic Recording using Exchange Bias

In this work a study of a new paradigm for the recording layer in a heat assisted magnetic recording (HAMR) media based on the use of exchange bias is presented. Exchange bias occurs when an antiferromagnetic (AF) layer such as IrMn is grown in contact with a ferromagnetic (FM) layer, which in our case happens to be also the recording layer resulting in a hysteresis loop shifted along the field axis. The FM layer when magnetised, serves to align the AF layer in the direction required to store the information and then provides a readout signal indicating in which direction the AF layer is oriented. Hence in a complex way the “recording layer” is actually part of the read/write head. By achieving spin alignment of the IrMn such that the spins are aligned perpendicular to the plane of the film, the required perpendicular exchange bias can be induced for information storage in the AF layer. A series of 14 set ofsamples have been prepared and evaluated to determine the optimised structure. A segregated CoCrPt-SiO2 sample was used as the recording layer from a pressed powder target in a HiTUS deposition system. Several seed layers were tested such as Ru, Pt and Cu for their ability to favour perpendicular anisotropy in double or combined form of 8 nm and 12 nm thicknesses respectively. They were deposited using 3 mTorr and 30 mTorr process pressure. XRD and XRR techniques were used in order to evaluate the structural properties of the multilayers. Alternating gradient force magnetometry and vibrating sample magnetometry at room and low temperature measurements were also used to characterise their magnetic response. The key feature of this media is that the recorded information is impossible to be erased by a demagnetising field. In order to achieve this requirement, the hysteresis loop has to be completely shifted to a negative field. In the current study a small shift up to Hex=325 Oe was achieved at 100K without the need of a Co interlayer. A complementary attempt was made to induce the desired exchange bias by depositing an ultrathin (0.8 nm) Co interlayer above a Pt and a Ru seed layer resulting in an exchange field of Hex=40 Oe. In addition, mixed seed layers were deposited using Ru/Pt and Ru/Cu with the first case showing the most promising results of squareness around 70% and coercivities of 1800 Oe. Because of the fact that loop shifts were observed at 100K, further work is required to optimise those structures

THE CONTRIBUTION OF MATHEMATICS ONLINE GAMES TO QUALITIVE DIFFERENTIATION AND INTRINSIC MOTIVATION OF STUDENTS WITH MILD INTELLECTUAL DISABILITIES

The purpose of this research is to examine the influence of a special education program, incorporating online digital games, on the understanding of basic mathematical concepts by students with mild intellectual disabilities. The research involved four students (one girl and three boys) with mild intellectual disabilities divided into two groups, an experimental (combined intervention) and a control group (standard intervention). The students' performance was assessed before the intervention program, immediately after the end of the program and two weeks after the completion of the intervention. Based on the results, improved performance was observed in the experimental group’s students, in the areas of intervention, in relation to the students in the control group. The experimental group’s students continued to perform at high standards, contrary to those of the control group. The findings show that the teaching approach integrating online digital games has a positive impact on the understanding of basic mathematical concepts by students with mild intellectual disabilities.  Article visualizations

THE RELATIONSHIP BETWEEN MUSICAL AUDIATION AND MATHEMATICAL PERFORMANCE IN SECOND GRADE CHILDREN IN PRIMARY SCHOOL

This research attempts to determine the relationship between musical Audiation and mathematical performance in second grade children. 36 children (N = 36) participated in the survey, 15 of whom were boys (N = 15) and 21 were girls (N = 21). For the assessment of musical audiation, Gordon's “Elementary Musical Audiation Measures” (Stamou, Schmidt & Humphreys, 2006) and a mathematical performance appraisal tool for second grade students were used by the researchers. The results showed a strong relationship between the overall performance of the musical Audiation and the mathematical performance, while also being a significant predictive factor. According to the results, the gender factor does not seem to be of any importance in the students' performance.  Article visualizations

COGNITIVE SKILLS AND MATHEMATICAL PERFORMANCE, MEMORY (SHORT-TERM, LONG-TERM, WORKING), MENTAL PERFORMANCE AND THEIR RELATIONSHIP WITH THE MATHEMATICAL PERFORMANCE OF PRE-SCHOOL STUDENTS

The purpose of this research is to examine the effect of cognitive capabilities and flowing intelligence on mathematical proficiency of pre-school students, shortly before attending elementary school. Eighty kindergarten students participated in the survey. Student performance was assessed in terms of short term memory (auditory and verbal short-term memory, visual short-term, semantic and non-semantic memory), working auditory and visual memory, visual long-term memory, fluid intelligence and math performance. Based on the results, there was a strong positive correlation (,777) between verbal working memory and mathematical performance. Moderate positive correlation between mathematical performance and short-term memory, visual spatial working memory, visual long-term memory and fluid intelligence was also found.To identify which factors have predictive value for mathematical competence, regression analysis was used. It has been found that verbal working memory is an important factor in explaining mathematical competence. Combined with long-term visual spatial working memory, they can more accurately predict the level of mathematical performance. The results show that verbal working memory is the best predictor of mathematical performance. Visual long-term memory follows, and finally visual spatial working memory seems to have the lowest impact on a student’s mathematical performance.  Article visualizations

Left Main Disease: Percutaneous Coronary Intervention (PCI) or Coronary Artery Bypass Grafting (CABG)? That is the Question

Left main (LM) coronary artery disease, arbitrarily defined as >50% diameter stenosis of the LM coronary artery, has long been a topic of intense diagnostic and therapeutic investigation, due to its poor prognosis. As the majority of the left ventricular myocardium is supplied by the LM stem, any ischemic insult may lead to hemodynamic compromise, significant ventricular arrhythmias or death

Nutrition and hydration for older adults living with dementia in care

Undernutrition and dehydration in older adults is of concern for healthcare professionals as well as the individuals and their families. The consequences of undernutrition, which are serious in all ages, however they are especially prominent in the older population. Being generally more vulnerable as well as not being able to recover promptly, older people are at higher risk of falls, more frequent and longer hospital stays, increased infections as well as increased risk of dying. Reduced appetite and thirst along with physical and cognitive impairments can make it difficult for older people to consume sufficient amount of food and fluids. The subsequent adverse events such as falls or infections can further influence nutritional status, creating a vicious cycle of undernutrition and disease. Once established, the cycle is almost impossible to escape. This is a major public concern, not only because quality of life is compromised for those affected but also due to the economic impact that these events have on society. Due to numerous functional and physiological alterations associated with age, older people frequently do not consume sufficient amounts of food and fluid and the diet is usually of poor quality. As a result, the prevalence of macro- and micronutrient undernutrition is high in both free-living and institutionalised older adults. It is estimated that prevalence of protein energy malnutrition may be as high as 15% in community dwelling older people, 25-65% in care home residents and 35-65% in older hospital patients. Early detection of undernutrition may be difficult because it cannot rely solely on anthropometric measurements and needs consideration of other factors. BMI for instance, is an established marker for nutritional status in younger populations but is not useful when assessing nutritional status in older persons. Sarcopenic obesity, which is a common problem within clinical setting and is especially prevalent in older patients, gives the impression that the person is over-nourished due to increased amount of fat mass but is in fact a type of undernutrition arising from an extensive muscle wastage caused by protein deficiency. This type of undernutrition usually occurs as a result of an acute decrease in food intake e.g., due to a sudden illness or food withdrawal. Recovering the muscle mass in older people is difficult, if not impossible in some circumstances. Chronic undernutrition on the other hand depletes all energy stores, leaving a person with little fat and muscle reserves. At this stage, micronutrient deficiencies are also common. People with dementia are particularly vulnerable to chronic undernutrition because they may forget to eat or they may lose the skills necessary for feeding, e.g. how to use the eating utensils

Stem Cells and Cardiac Repair

Contrary to the initial belief that the heart is a terminally differentiated organ that cannot replace its own cell damage, there is now proof that the circulating blood provides the injured tissue with adult stem and progenitor cells, which have the potential to differentiate into cardiomyocytes and ultimately improve cardiac function. Thus, transplantation of stem cells into the myocardium in patients with severe myocardial dysfunction post-myocardial infarction is being currently investigated for experimental as well as for clinical purposes. Many issues regarding the mode of action remain to be elucidated. The BOOST trial was the first completed, randomized study that showed safety, feasibility and efficacy of the method. However, a more recent doubleblind, placebo-controlled study failed to reveal an increase in global left ventricular nejection fraction and cast doubt on the efficacy of the method. Thus, further randomized studies are needed to evaluate this novel approach in the treatment of ischemic heart failure and determine its role, safety and efficacy

Restitution of the Infarcted Myocardium- the Role of Stem Cells

Even after optimal reperfusion strategies implementing percutaneous coronary intervention (PCI) with stent implantation and modern medical regimen for patients with acute myocardial infarction, myocardial salvage is often incomplete and adverse ventricular remodeling with subsequent heart failure develops. The transplantation of autologous bone marrow stem cells (BM-SCs) via the intracoronary delivery route after PCI of the infarct related artery (IRA) has been investigated in several observational studies which proved the safety and feasibility of the method. The results of the randomized studies were rather controversial. The BOOST study (Bone Marrow transfer to enhance ST-elevation infarction regeneration) was the first randomized study with patients receiving either bone-marrow derived mononuclear cells or placebo 5 days after primary PCI. The improvement of the ejection fraction reported in the cell infusion group at 6 months was attenuated during a follow-up study of 18 months. Of note, a similar restenosis rate (13%) was reported between the 2 groups