Concurrent π\pi-vector fields and energy beta-change

The present paper deals with an \emph{intrinsic} investigation of the notion of a concurrent $\pi$-vector field on the pullback bundle of a Finsler manifold $(M,L)$. The effect of the existence of a concurrent $\pi$-vector field on some important special Finsler spaces is studied. An intrinsic investigation of a particular $\beta$-change, namely the energy $\beta$-change ($\widetilde{L}^{2}(x,y)=L^{2}(x,y)+ B^{2}(x,y) with \ B:=g(\bar{\zeta},\bar{\eta})$;$\bar{\zeta} $being a concurrent$\pi$-vector field), is established. The relation between the two Barthel connections$\Gamma$and$\widetilde{\Gamma}$, corresponding to this change, is found. This relation, together with the fact that the Cartan and the Barthel connections have the same horizontal and vertical projectors, enable us to study the energy$\beta$-change of the fundamental linear connection in Finsler geometry: the Cartan connection, the Berwald connection, the Chern connection and the Hashiguchi connection. Moreover, the change of their curvature tensors is concluded. It should be pointed out that the present work is formulated in a prospective modern coordinate-free form.Comment: 27 pages, LaTex file, Some typographical errors corrected, Some formulas simpifie

Practical Provably Secure Multi-node Communication

We present a practical and provably-secure multimode communication scheme in the presence of a passive eavesdropper. The scheme is based on a random scheduling approach that hides the identity of the transmitter from the eavesdropper. This random scheduling leads to ambiguity at the eavesdropper with regard to the origin of the transmitted frame. We present the details of the technique and analyze it to quantify the secrecy-fairness-overhead trade-off. Implementation of the scheme over Crossbow Telosb motes, equipped with CC2420 radio chips, shows that the scheme can achieve significant secrecy gain with vanishing outage probability. In addition, it has significant overhead advantage over direct extensions to two-nodes schemes. The technique also has the advantage of allowing inactive nodes to leverage sleep mode to further save energy.Comment: Proceedings of the IEEE International Conference on Computing, Networking and Communications (ICNC 2014

The Dimensions of Critical Thinking and it’s Relation to Improving the Quality of Life among Female Students at the College of Education, Jouf University

The current study aimed to identify the relationship between the dimensions of critical thinking and quality of life in the light of some variables (academic level, specialization). The study sample consisted of (188) female students at the College of Education, Jouf University, majoring in early childhood and Islamic studies for the academic year 1443 AH / 2021 AD. The descriptive approach, critical thinking scale and quality of life scale have been used to achieve the objectives of the study. The results revealed an average level of critical thinking and quality of life among female students at the College of Education, where the percentages were (68.23%), (71.23%), respectively. There were no statistically significant differences between female students of different academic levels (from the second to the eighth level) on all dimensions of the critical thinking scale and its total score. While there were statistically significant differences between female students majoring in early childhood and Islamic studies in dimensions (interpretation, evaluation of arguments, deduction) and the total score of the critical thinking scale in the direction of early childhood students. However, no statistically significant differences were detected in the other two dimensions (recognition of assumptions, inference). Also, there were no statistically significant differences between students of different academic levels on the dimensions of the quality-of-life scale. There was a statistically significant positive relationship between the dimensions of the critical thinking scale and all dimensions of the quality-of-life scale and its total score. The study recommends conducting more scientific and psychological studies that shed light on the dimensions of critical thinking and the quality of life for university students in line with the Kingdom of Saudi Arabia’s vision of 2030

Posterior Reversible Encephalopathy Syndrome in a Child with Steroid Sensitive Nephrotic Syndrome

Introduction: Posterior reversible encephalopathy syndrome (PRES) was described in adults more than children. It was reported in cases of nephrotic syndrome which were mainly on immunosuppressant medicationsor had severe hypertension.Case report: We report the case of a 9-years old girl who presented with nephrotic syndrome and moderate hypertension. Nine days after the initiation of steroid therapy she developed disturbed level of consciousnessand generalized tonic clonic seizures. Her blood pressure was 145/90 mm Hg and she had normal serum creatinine and electrolytes levels. She was treated with furosemide and convulsions were controlled. After regainingconsciousness, the patient complained of loss of vision. Fundal  examination was normal. Magnetic resonant  imaging, axial FLAIR images and diffusion weighted imaging showed hyper-intensity signal in the parieto-occipital areas. Magnetic resonant arteriography and spectroscopy excluded ischemic insults and neoplastic process. She regained full consciousness and normal vision and was discharged from the ICU four days later. PRES was diagnosed based on the typical pattern of brainimaging and the reversibility of symptoms. .Conclusion: Nephrotic syndrome in children should be considered a risk factor for developing PRES even without the use of immunosuppressant agents or high doses of steroids

Health-related quality of life, symptoms experience and perceived social support among patients with liver cirrhosis: a cross-sectional study in Egypt

Background: Liver cirrhosis is a global health problem and a national health problem in Egypt. There is a lack of literature on Health-Related Quality of Life (HRQOL) and symptoms experience of liver disease and cirrhotic patients in Middle East, particularly in Egypt. Aims: This PhD had three major aims: First aim: To describe HRQOL of Egyptian liver cirrhotic patients and to identify and evaluate the factors associated with (HRQOL) physical and mental health domains. Second aim: To explore and describe experienced symptoms (prevalence, severity and hindrance) in Egyptian cirrhotic patients and to identify and evaluate factors associated with symptoms severity and symptoms hindrance (distress). Third aim: To explore and describe how cirrhotic patients in Egypt perceive social support from spouse, family and friends and to identify and evaluate factors associated with general perceived social support. Method: A cross-sectional study with a convenience sample of 401 patients from three hospitals in Cairo, Egypt, was conducted between June and August 2011. Patients were interviewed to complete a background data sheet, Short Form-36v2 (SF-36), the Liver Disease Symptom Index (LDSI)-2.0 and the Multidimensional Scale of Perceived Social Support (MSPSS). Results: Findings for first aim: The findings showed that all domains and component summary scores [Physical component summary score (PCS) and mental component summary score (MCS)] of the generic SF-36 were below the norm (cut-off score 50), suggesting that patients with liver cirrhosis in Egypt have poor HRQOL. About 87.2% of the patients rated their general health as poor or fair, which means the majority of these patients have low perceived general health. Many socio-demographic and medial factors were shown to be significantly associated with perceived HRQOL. Women, illiterate and unemployed people, and patients with frequent hospitalisation had poor PCS and MCS, while patients with advanced disease stage, increasing number of comorbidities and complications and those admitted to inpatients had significantly poorer PCS only. Perceived social support from a spouse had a statistically significant positive association with PCS and MCS, while perceived social support from family and friends had a statistically significant positive association with MCS only. Also, severity and hindrance of symptoms significantly correlated with PCS and MCS. Using stepwise multiple linear regression analysis, two models were developed to identify factors associated with PCS (Model 1) and MCS (Model 2) health. Model 1 could significantly explain 19% of the variation in PCS (R2 = 0.190, R2adj = 0.180, p = 0.0005), and four factors (symptoms severity, disease stage, comorbidities and employment status) were significantly (p ≤ 0.02) associated with PCS. Model 2 could significantly explain 31.7% of the variation in MCS (R2 = 0.317, R2adj = 0.308, p = 0.0005), and four factors (symptoms severity, employment status, perceived spouse support and perceived family support) were associated (p ≤ 0.04) with MCS. The key findings of this study were that severity of symptoms and social support from spouse and family were associated with HRQOL. Where patients with high symptoms severity were likely to report poor PCS and MCS; and patients with low perceived social support were likely to report poor MCS. Symptoms severity contributed significantly in explaining 28.7% of the variation in PCS and 43.6% of the variation in MCS. Findings for second aim: This study found that the majority of patients had one or more of a wide range of symptoms and social problems. Two-thirds of patients reported joint pain (78.3%), decreased appetite (75.6%) and memory problems (77.3%). Joint pain and depression were reported to have the biggest impact on daily life. Symptoms severity and distress were significantly higher among patients who were: female, illiterate, unemployed, and who had advanced cirrhosis with more complications and comorbidities (p ≤ 0.006). Symptoms severity (r=-0.206) and symptoms distress (r=-0.205) were negatively associated with perceived social support (p=0.005). Stepwise regression analysis showed that the regression model could significantly explain 19.6% of the variation in symptoms severity (R2 = 0.196, R2adj = 0.180, p = 0.0005), and 14% of the variation in hindrance of symptoms (R2 = 0.140, R2adj = 0.132, p = 0.0005). Being female, having an increasing number of liver disease complications, and having low perceived support from spouse were significantly associated with high-perceived symptoms severity and hindrance (p≤0.01). Findings for third aim: This study found that social support score was relatively high among patients with cirrhosis in Egypt (total score mean of MSPSS was 2.02± standard deviation (0.537), while perceived support from spouse was the highest source of support. 67.5% of the patients felt their spouse is around when they need him/her and 71.7% of them share their joys and sorrows with their spouse. Likewise, 64.9% of married people feel their spouse cares about their feelings. In relation to the perception of adequacy of family support, it was observed that 52.6% felt that their families do not really try to help them. At the same time, 52.1% reported that they got the emotional help and support that they needed from their families. Regarding perceived support from friends, more than half of the patients reported that their friends do not really try to help them (57.9%), they cannot count on their friends when things go wrong (65.6%) and they cannot talk about their problems with their friends (56.4%). There was a significantly positive association between the perception of social support and general health perception (GHP), suggesting that when social support decreases GHP also decreases or and vice versa (r= 0.208, p = 0.0005). Stepwise regression analysis showed that the regression model could significantly explain 10.9% of the variation in perceived social support (R2 = 0.109, R2adj = 0.100, p = 0.0005). Marital status, gender, age and employment status were significantly associated with general perceived social support (p ≤ 0.01), while unmarried, females, unemployed and elderly cirrhotic patients were vulnerable groups that were likely to perceive low social support. Overall discussion and conclusion: This is the first study to investigate HRQOL, symptoms experience and perceived social support in patients with liver cirrhosis in Egypt. All aspects of HRQOL of Egyptian cirrhotic patients were poor, and they were experiencing various symptoms that can affect their daily life. However, social support was found to be related to perceived symptoms severity and perceived poor mental health. Hence, social support may alleviate suffering for certain cirrhotic patients. Nurses have a responsibility to assess and treat symptoms that cirrhotic patients experience, particularly such treatable symptoms as depression, pain and decreased appetite. Also, nurses should involve the patient’s family in any plan of care. Future intervention studies that aim to develop programs to relieve treatable symptoms and enhance social support are also recommended

Magnetic properties of exchange biased and of unbiased oxide/permalloy thin layers: a ferromagnetic resonance and Brillouin scattering study

Microstrip ferromagnetic resonance and Brillouin scattering are used to provide a comparative determination of the magnetic parameters of thin permalloy layers interfaced with a non-magnetic (Al2O3) or with an antiferromagnetic oxide (NiO). It is shown that the perpendicular anisotropy is monitored by an interfacial surface energy term which is practically independent of the nature of the interface. In the investigated interval of thicknesses (5-25 nm) the saturation magnetisation does not significantly differ from the reported one in bulk permalloy. In-plane uniaxial anisotropy and exchange-bias anisotropy are also derived from this study of the dynamic magnetic excitations and compared to our independent evaluations using conventional magnetometryComment: 7 pages, 6 figures, submited to Journal of Physics: Condensed Matte

Performance of Preload on Cohesionless Soils

Common occurrence of loose normally consolidated fine sands and silts extending to considerable depths necessitates the utilization of ground improvement techniques along the coasts of Arabian Peninsula. In the case considered, the soil profile consisted of twenty meter thick compressible sands, and preloading technique was suggested to stabilize the foundation soil. The paper presents the performance of the preloading and the level of soil improvement achieved. The observed settlements and settlement-time behaviour are compared with the values estimated from various methods. The soil parameters back calculated from measured field behaviour are reported

Magnetic resonance studies of the fundamental spin-wave modes in individual submicron Cu/NiFe/Cu perpendicularly magnetized disks

Spin wave spectra of perpendicularly magnetized disks with trilayers consisting of a 100 nm permalloy (Py) layer sandwiched by two Cu layers of 30 nm, are measured individually with a Magnetic Resonance Force Microscope (MRFM). It is demonstrated by 3D micromagnetic simulations that in disks having sub-micron size diameters, the lowest energy spin wave mode of the saturated state is not spatially uniform but rather is localized at the center of the Py/Cu interface in the region of a minimum demagnetizing field

The method of meshless fundamental solutions with sources at infinity

The method of external source collocation is used to solve a discretised boundary value problem, ∇2U = 0, where U is the potential in a two-dimensional simply-connected region D, subject to a mixture of Neumann and Dirichlet boundary conditions. Numerical analysis has, to date, been hindered by an accumulation of round-off error, which has made it impossible to investigate accuracy of the Meshless Fundamental Solutions method unless sources are near the boundary. Symbolic analysis allows a full investigation of ill-conditioned systems in which sources can be placed "at infinity". This analysis provides an indication of how many sources must be used and where they should be placed

Thyroid hormone dysfunctions affect the structure of rat thoracic aorta: a histological and morphometric study

Background: There are limited data about the influence of hypothyroidism and hyperthyroidism on the connective tissue component and smooth muscle cells of the thoracic aorta. The aim was to study the histological changes of the wall of the thoracic aorta in the hypothyroid and hyperthyroid rats. Morphometric measurements were also done.Materials and methods: Thirty adult rats were used. They were divided into control, hyperthyroid, and hypothyroid groups. Each group consisted of 10 rats. The animals were sacrificed at the end of 8 weeks and the descending aorta was excised. Sections were stained with haematoxylin and eosin, orcein and Masson’s trichrome stains. Themorphometric measurement included: number of smooth muscle cell nuclei, number of the elastic lamellae, thickness of the tunica media, elastic fibre optic density, and relative collagen area.Results: Atheromatous plagues had been observed in the hyperthyroid group. Thinning and rupture of the elastic lamellae had been observed in the hypothyroid group; these were accompanied with intimal ulceration and aortic dissection. The average number of smooth muscle cell nuclei in the hyperthyroid group had doubled and tripled compared to their fellows in the control and hypothyroid groups, respectively. The thickness of the tunica media increased in the hyperthyroid and hypothyroid groups by 75% and 35%. In addition, the relative collagen area increased in the previously mentioned groups by 142% and 120%, respectively. On the other hand, the mean elastic fibre optic density decreased in both groups by 30%.Conclusions: Structure wall affections of the intima and media of the descending aorta were associated with the thyroid hormone dysfunctions. These changes were more severe in the hypothyroid group.