An Efficient Cache Organization for On-Chip Multiprocessor Networks

To meet the growing computation-intensive applications and the needs of low-power, high-performance systems, the number of computing resources in single-chip has enormously increased. By adding many computing resources to build a system in System-on-Chip, its interconnection between each other becomes another challenging issue. In most System-on-Chip applications, a shared bus interconnection which needs an arbitration logic to serialize several bus access requests, is adopted to communicate with each integrated processing unit because of its low-cost and simple control characteristics. This paper focuses on the interconnection design issues of area, power and performance of chip multi-processors with shared cache memory. It shows that having shared cache memory contributes to the performance improvement, however, typical interconnection between cores and the shared cache using crossbar occupies most of the chip area, consumes a lot of power and does not scale efficiently with increased number of cores. New interconnection mechanisms are needed to address these issues. This paper proposes an architectural paradigm in an attempt to gain the advantages of having shared cache with the avoidance of penalty imposed by the crossbar interconnect. The proposed architecture achieves smaller area occupation allowing more space to add additional cache memory. It also reduces power consumption compared to the existing crossbar architecture. Furthermore, the paper presents a modified cache coherence algorithm called Tuned-MESI. It is based on the typical MESI cache coherence algorithm however it is tuned and tailored for the suggested architecture. The achieved results of the conducted simulated experiments show that the developed architecture produces less broadcast operations compared to the typical algorithm

MANAGEMENT’S PERCEPTION OF STOCK DIVIDEND DISTRIBUTION IN AN EMERGING CAPITAL MARKET: THE CASE OF KUWAIT

The purpose of this study is to investigate perceptions of top managers of Kuwaiti companies regarding factors the affect their companies’ decision to distribute stock dividend ( SD ). A questionnaire listing 32 reasons that could explain companies’ decisions to declare SDs was distributed to a sample of 120 randomly selected top managers from 100 Kuwaiti companies and 73 responses were received (representing a 61% response rate ). Participants were classified according to: ( 1 )business sector ( investment, real estate, banking, service, and industrial ) and ( 2 ) size of SDs ( small ( less than 25% ) and large ( 25% or more )). Nonparametric statistical tests were employed to analyze the data.Stock Dividends, Importance Ratings, Trading Liquidity, Institutional Investors

Preparation and Analysis of Cement Bricks Based on Rice Straw

In Egypt, rice straw is burnt as an easy and the cheap method to get rid of it leads to making a giant black cloud covers Cairo and southern delta governorates. Main purpose of this research is to produce green brick of cement and in-expensive agriculture waste (rice straw) with law price and good characteristics of thermal insulation and acoustic resistance. Different samples of cement brick based on rice straw of many percentages were prepared. First, select best mixture of concrete brick before adding rice straw after preparing and leave for curing time. Then, rice straw is added with various percentage based on total mass of dry mixture to selected concert brick mixture. The selection of best mixture of green bricks criteria is first depending on achieving minimum compression strength according to Egyptian specification then maximizing the percentage of rice straw added. The two mixtures of cement bricks that have maximum compression strength are 1:2:2 and 1:4:5 of 6.2 and 3.1 MPa. The highest percentage of rice straw can be added to later cement mixture is 3% additional quantities based on total mass of mixture dry base of 2.9 MPa. The impact of 3% addition of rice straw on cement bricks enhances thermal by 21.05% by comparing with cement brick of ratio 1:2:2. It decreases sound pressure level inside room from 62 dB to 45 dB. Although, cement bricks reduce sound pressure level to 55 dB. Thousands of cement bricks with 3% rice straw cost are less 8.3% the cost of thousands of cement brick with market ratio 1:4:5. Cement brick of ratio 1:4:5 that used by OPAKI company in Egypt for cement brick manufacturing is used with adding 3% of rice straw. Whatever, it gives very low resistance against compression lower than Egyptian specifications. This mixture of 3% rice straw base is enhanced by nano-silicon addition percentage of sand portion of 2.1 MPa compression test, although cost of thousand bricks is almost equal to the cost of thousands of commercial market bricks. Eventually, life cycle assessment of rice straw is better than normal cement brick mixture materials that helps in reducing greenhouse emissions and energy consumed

Malaria Parasitemia during delivery

Objectives:  The aim of this study is to investigate the impact of plasmodium falciparum infection in parturient women in Central Sudan where malaria transmission is mesoendemic. The purpose of this paper is to find out the prevalenceof malaria parasitemia and the risk of anemia among parturient women and to suggest appropriate strategies to lower their prevalence rates. Methods:  This prospective study was conducted at Medani Teaching Hospital, Sudan a tertiary regional referral center, during the period January 1997 through to December 1997. All cases were admitted during labor to the delivery room and were clinically suspected to have malaria. History, examination and investigations were carried out on all patients. Results: The total number of patients enrolled in this study was 550, amounting to 14.9% of all women (N=3,687) who delivered during the study period. The prevalence of malaria parasitemia was 58.9% (N=550) while prevalence of anemia (defined as hemoglobulin   ….9.0 g/dl) was 24.1% the mean hemoglobuin levels in patients with positive and negative malaria parasitemia was 9.72+ 1.62 and 9.85+ 1.60 g/dl. Statistically the difference in the mean hemoglobulin level was not significant, t=0.879, A significant negative correlation between parasite count in maternal blood and hemoglobulin level of the mother, was observed, where r=0.121 (P=0.032). out of 17 (3.3%) patients who had used chloroquine tablets for prophylaxis, 11patients still had positive parasitemia. Although there was a higher parasite count in those 11 patients, statistically the difference was not significance where P< 0.0

The relationship between associative learning, transfer generalization, and homocysteine levels in mild cognitive impairment

Previous studies have shown that high total homocysteine levels are associated with Alzheimer's disease (AD) and mild cognitive impairment (MCI). In this study, we test the relationship between cognitive function and total homocysteine levels in healthy subjects (Global Dementia Rating, CDR = 0) and individuals with MCI (CDR = 0.5). We have used a cognitive task that tests learning and generalization of rules, processes that have been previously shown to rely on the integrity of the striatal and hippocampal regions, respectively. We found that total homocysteine levels are higher in MCI individuals than in healthy controls. Unlike what we expected, we found no difference between MCI subjects and healthy controls in learning and generalization. We conducted further analysis after diving MCI subjects in two groups, depending on their Global Deterioration Scale (GDS) scores: individuals with very mild cognitive decline (vMCD, GDS = 2) and mild cognitive decline (MCD, GDS = 3). There was no difference among the two MCI and healthy control groups in learning performance. However, we found that individuals with MCD make more generalization errors than healthy controls and individuals with vMCD. We found no difference in the number of generalization errors between healthy controls and MCI individuals with vMCD. In addition, interestingly, we found that total homocysteine levels correlate positively with generalization errors, but not with learning errors. Our results are in agreement with prior results showing a link between hippocampal function, generalization performance, and total homocysteine levels. Importantly, our study is perhaps among the first to test the relationship between learning (and generalization) of rules and homocysteine levels in healthy controls and individuals with MCI

Hydrogels and Dentin-Pulp Complex Regeneration: From the Benchtop to Clinical Translation

Dentin-pulp complex is a term which refers to the dental pulp (DP) surrounded by dentin along its peripheries. Dentin and dental pulp are highly specialized tissues, which can be affected by various insults, primarily by dental caries. Regeneration of the dentin-pulp complex is of paramount importance to regain tooth vitality. The regenerative endodontic procedure (REP) is a relatively current approach, which aims to regenerate the dentin-pulp complex through stimulating the differentiation of resident or transplanted stem/progenitor cells. Hydrogel-based scaffolds are a unique category of three dimensional polymeric networks with high water content. They are hydrophilic, biocompatible, with tunable degradation patterns and mechanical properties, in addition to the ability to be loaded with various bioactive molecules. Furthermore, hydrogels have a considerable degree of flexibility and elasticity, mimicking the cell extracellular matrix (ECM), particularly that of the DP. The current review presents how for dentin-pulp complex regeneration, the application of injectable hydrogels combined with stem/progenitor cells could represent a promising approach. According to the source of the polymeric chain forming the hydrogel, they can be classified into natural, synthetic or hybrid hydrogels, combining natural and synthetic ones. Natural polymers are bioactive, highly biocompatible, and biodegradable by naturally occurring enzymes or via hydrolysis. On the other hand, synthetic polymers offer tunable mechanical properties, thermostability and durability as compared to natural hydrogels. Hybrid hydrogels combine the benefits of synthetic and natural polymers. Hydrogels can be biofunctionalized with cell-binding sequences as arginine-glycine-aspartic acid (RGD), can be used for local delivery of bioactive molecules and cellularized with stem cells for dentin-pulp regeneration. Formulating a hydrogel scaffold material fulfilling the required criteria in regenerative endodontics is still an area of active research, which shows promising potential for replacing conventional endodontic treatments in the near future

Pituitary apoplexy can mimic acute meningoencephalitis or subarachnoid haemorrhage

Pituitary apoplexy is an uncommon but life-threatening condition that is often overlooked and underdiagnosed. We report a 45-year-old man who presented to our emergency department with a sudden onset headache, acute confusion, signs of meningeal irritation and ophthalmoplegia. An initial diagnosis of acute meningoencephalitis was made, which was amended to pituitary apoplexy following thorough investigation within the emergency department

Spontaneous upper limb monoplegia secondary to probable cerebral amyloid angiopathy

Cerebral amyloid angiopathy is a clinicopathological disorder characterised by vascular amyloid deposition initially in leptomeningeal and neocortical vessels, and later affecting cortical and subcortical regions. The presence of amyloid within the walls of these vessels leads to a propensity for primary intracerebral haemorrhage. We report the unusual case of a 77-year-old female who presented to our emergency department with sudden onset isolated hypoaesthesia and right upper limb monoplegia. A CT scan demonstrated a peripheral acute haematoma involving the left perirolandic cortices. Subsequent magnetic resonance imaging demonstrated previous superficial haemorrhagic events. One week following discharge the patient re-attended with multiple short-lived episodes of aphasia and jerking of the right upper limb. Further imaging demonstrated oedematous changes around the previous haemorrhagic insult. Cerebral amyloid angiopathy is an overlooked cause of intracerebral haemorrhage; the isolated nature of the neurological deficit in this case illustrates the many guises in which it can present

Influence of reaction time and synthesis temperature on the physical properties of ZnO nanoparticles synthesized by the hydrothermal method

Influence of synthesis temperature and reaction time on the structural and optical properties of ZnO nanoparticles synthesized by the hydrothermal method was investigated using X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray, Fourier transform infra-red spectroscopy, and UV–visible and fluorescence spectroscopy. The XRD pattern and HR-TEM images confirmed the presence of crystalline hexagonal wurtzite ZnO nanoparticles with average crystallite size in the range 30–40 nm. Their energy gap determined by fluorescence was found to depend on the synthesis temperature and reaction time with values in the range 2.90–3.78 eV. Thermal analysis, thermogravimetric and the differential scanning calorimetry were used to study the thermal reactions and weight loss with heat of the prepared ZnO nanoparticles