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

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

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

Simplified method for predicting deformations of RC frames during fire exposure

Structural engineers are in need of analytical methods to assess the performance of Reinforced Concrete (RC) frames during fire events. Existing numerical methods require extensive knowledge of heat transfer calculations and the finite element method. This paper proposes a practical approach to track the fire performance of indeterminate RC frames during ASTM-E119 and ISO 834 standard fires exposure. The proposed method utilizes a finite difference method to predict the temperature distribution within the section of the RC frame. The predicted elevated temperatures are then used to conduct a sectional analysis. The effective flexural and axial stiffnesses are evaluated and used to predict the overall behavior of the structure during fire. The proposed approach is validated by comparing its predictions with analytical results by others

A Survey on Retrieval of Mathematical Knowledge

We present a short survey of the literature on indexing and retrieval of mathematical knowledge, with pointers to 72 papers and tentative taxonomies of both retrieval problems and recurring techniques.Comment: CICM 2015, 20 page

A Comparison of Time-Memory Trade-Off Attacks on Stream Ciphers

Contains fulltext : 117176.pdf (preprint version ) (Open Access

Mechanisms of disruption of meristematic competence by microgravity in Arabidopsis seedlings

16 p.-2 fig.Experiments performed in actively proliferating plant cells both in space and simulated microgravity have evidenced a common effect: cell proliferation appears enhanced whereas cell growth is depleted. Coordination of cell growth and proliferation, called meristematic competence, is a major feature of meristematic cells and its disruption may lead to important alterations in the developmental pattern of the plant. Auxin is known to be a mediator of the transduction of the gravitropic signal and a regulator of the rates of growth and proliferation in meristematic cells, as well as of their further differentiation. Therefore, gravity sensing, gravitropism, auxin levels and meristematic competence are mutually interrelated. However, our experiments in simulated microgravity, using both mechanical and magnetic levitation technologies, have revealed that this interdependence is neither strict nor univocal and may include additional factors and mechanisms. Available data indicate that altered gravity may affect cell growth and proliferation by mechanisms alternative to the transduction of the gravitropic signal perceived by columella cells in the root tip. These mechanisms would include gravity sensing independent from statolith displacement and transduction mediators other than polar auxin transport.Work performed in the authors’ laboratory was supported by grants of the Spanish National Plan for Research and Development, Ref. Nos. AYA2010-11834-E, and AYA2012-33982 and by ESA Access to GBFs contract numbers 4200022650 & 4000105761. MAV was supported by the Spanish FPI Program (Ref. BES-2010-035741) and KY by the Spanish CSIC JAE-PreDoc Program (Ref. JAEPre_2010_01894).Peer reviewe

Detection and identification of Apple stem pitting virus and Apple stem grooving virus affecting apple and pear trees in Egypt

Apple stem pitting virus (ASPV) and Apple stem grooving virus (ASGV) are economically important and infect either individually or in mixed infection commercial apple and pear cultivars causing yield loses. Young green bud and/or base of petiole were collected from naturally infected apple and pear trees from different locations in Egypt. Both viruses were detected frequently in apple and pear samples. A total of 420 trees from 9 different orchards were tested using one-step RT-PCR; 13% and 17% of these samples were infected with ASPV and ASGV, respectively. Mixed infection with both viruses occurred in 4% of the tested trees. ELISA was reliable for detection of ASGV but not ASPV. Total RNA for one-step RT-PCR was isolated from 100 mg fresh affected apple and pear leaf tissue using Qiagen RNeasy plant mini-kit (Qiagen, Crawley, UK), according to the manufacturer’s instructions. The one step-RTPCR method was performed using ASPV and ASGV-specific primers for each virus. A 316 bp fragment for ASPV and 524bp fragment for ASGV were amplified and detected by gel electrophoresis analysis which indicated the presence of ASPV and ASGV in affected apple and pear cultivars. Southern blot hybridization of the amplified products to digoxigenin (DIG)-labeled cDNA probe for ASPV or ASGV confirmed the results obtained by electrophoresis analysis. No product was detected in amplified extracts of uninfected apple and pear samples. The detection of ASPV and ASGV by one step-RT-PCR assay was successful and appears useful for testing pome fruit germplasm in quarantine and budwood in certification programs.Keywords: Apple and pear, ASPV, ASGV, virus detection, One step RT-PCR, Southern blot hybridizatio

Magnetostrictive hysteresis of TbCo/CoFe multilayers and magnetic domains

Magnetic and magnetostrictive hysteresis loops of TbCo/CoFe multilayers under field applied along the hard magnetization axis are studied using vectorial magnetization measurements, optical deflectometry and magneto optical Kerr microscopy. Even a very small angle misalignment between hard axis and magnetic field direction is shown to drastically change the shape of magnetization and magnetostrictive torsion hysteresis loops. Two kinds of magnetic domains are revealed during the magnetization: big regions with opposite rotation of spontaneous magnetization vector and spontaneous magnetic domains which appear in a narrow field interval and provide an inversion of this rotation. We show that the details of the hysteresis loops of our exchange-coupled films can be described using the classical model of homogeneous magnetization rotation of single uniaxial films and the configuration of observed domains. The understanding of these features is crucial for applications (for MEMS or microactuators) which benefit from the greatly enhanced sensitivity near the point of magnetic saturation at the transverse applied field.Comment: 10 pages, 11 figure