Effect of age on the biomechanical and microcirculatory properties of the skin in healthy individuals and during venous ulceration.

BACKGROUND: With aging there is alteration of elastic properties of the skin and skin-blood flow. AIM: The purpose of this study was to compare age-related changes in selected biomechanical parameters of the skin (skin hardness, skin extensibility, relaxation time constant, τ) and subcutaneous microcirculatory quality (SMQ) in individuals with and without venous diseases. MATERIALS AND METHODS: TWO GROUPS WERE STUDIED: the first group was of asymptomatic healthy individuals and the second group included patients with chronic venous insufficiency (CVI) and venous ulceration, without edema. Both groups were subdivided to three age categories (21-40, 41-60 and 61-90 years old). Skin hardness was measured by durometer, extensibility and τ were measured using extensometer and SQM was assessed via postural vasoconstrictive response (LDF). RESULTS: Results showed that skin hardness, extensibility, and τ-values were increased, whereas LDF was decreased in the older groups as compared with younger groups. These changes are attributed to alterations in the skin structure and reduced capillaries density networks. Similar behavior was found in the biomechanical and microcirculatory changes in patients with venous ulceration and CVI, but these changes were more increased further in older patients with venous ulceration as compared with older patients with CVI and that can be attribute to more intense response against tissue injury. CONCLUSIONS: Since aging elevated skin hardness and extensibility, but lowered vasoconstrictive response in individuals, with and without, venous diseases, we conclude that aging process is likely to cause an accumulation of damaged skin tissues and that could induce an apparent antigen-driven response that altered skin structure and the subsequent biomechanical properties obtained in this stud

Wireless propagation channel modeling for optimized handoff algorithms in wireless LANs

We present, firstly, a simple time-series analysis techniques which cover the basic concepts and mechanisms driving the wireless propagation channel. We also use a generated series for simulation study of Handoff performance showing the impact of multipath phenomena. The extraction of the overage signal (slow variations) from the fast variations was done. This overall signal has been used to reduce significantly the number of unnecessary handoffs. To better minimize the power consumption, that the wireless propagation channel requires, our proposed approach was verified at the algorithmic level using Matlab 7.6 tool, described in Very-high-speed integrated circuit Hardware Description Language (VHDL) at the register transfer level (RTL) and it has been synthesized using ISE 10.1 of the field-programmable gate array (FPGA) environment xilinx virtex V that evaluates the circuit in terms of speed, area and power consumption. The wireless propagation channel modeling is based on the linear model concept of the received power from the access point (AP). This concept has a crucial role in modeling new decentralized handoff based on the ratio of expected and current signal slopes already provided by the linear model. Hence, a fuzzy-based solution is developed and a comparison with the analytical solution results is established

Weak solutions of quasilinear biharmonic problems with convex nonlin- earities

We study the existence of positive weak solutions to a fourth-order semi- linear elliptic equation with Navier boundary conditions and a positive, increasing and convex source term. We also prove the uniqueness of extremal solutions. In particular, we generalize results of Mironescu and R˘adulescu for the bi-Laplacian operator

Evaluation of Heavy Metal Pollution in the Arabian Gulf

The present study is an attempt to assess the heavy metal contamination in the marine environment of the Arabian Gulf of Saudi Arabia. The concentrations of heavy metals in water and the soft tissues of the bivalve species Meretrix meretrix Linnaeus, 1758, from different stations along the Arabian Gulf coastline, were determined during the summer season of 2008. Bioaccumulation of some heavy metals (Cd, Pb, Cu, and Zn) in fresh parts of the clam (M. meretrix) was measured by an atomic absorption spectrophotometer. The average concentrations of heavy metals in the clam tissues were 0.224–0.908, 0.294–2.496, 3.528–8.196, and 12.864–24.56 mg/kg wet weight for Cd, Pb, Cu, and Zn, respectively. In water, the mean concentration values of these metals were arranged in the following descending order: Pb > Cu > Zn > Cd. The heavy metal concentrations in tissues of M. meretrix were within the acceptable standards set by the US Environmental Protection Agency, the Commission Européenne, and the Food and Drug Administration of the USA. From the human public health point of view, these results seem to show no possibility of acute toxicities of Cd, Cu, Pb, and Zn if the edible clam is consumed. It is recommended that relevant authorities should carry out a continual assessment on the levels of these pollutants in the studied are

Effectiveness of metal-organic frameworks for removal of refractory organo-sulfur compound present in liquid fuels

Adsorption of organo-sulfur compounds present in liquid fuels on metal-organic framework (MOF) compounds is an efficient alternative to the conventional hydrodesulfurization process. It has been demonstrated that the extent of dibenzothiophene (DBT) adsorption at temperatures close to ambient (304 K) is much higher on MOFs systems than on the benchmarked Y-type zeolite. In addition, the DBT adsorption capacity depends strongly on the MOF type as illustrated by the much higher extent of adsorption observed on the copper- (C300) and Al-containing (A100) MOF systems than on the Fe-containing (F300) MOF counterpart. With the aim to investigate the operation in consecutive cycles, the MOFs used in adsorption experiments were regenerated. In addition, the remaining S-containing compounds were identified and quantified by photoelectron spectroscopy (XPS). Examination of S2p core-level spectrum of the adsorbed S-compounds of regenerated MOFs pointed out that a fraction of these molecules become oxidized into S(VI) species

EFL female faculty menders belief a bout CALL Use and Integration in EFL Instructor

يناقش البحث توجهات الهيئة التدريسية النسائية بأربع جامعات سعودية نحو استخدام الحاسب الآلي في تعليم اللغة وتوصلت الدراسة إلى أنه لا يوجد فروق ذات دلالة إحصائية فيها يتعلق بالعمر أو الرتبة العلمية أو الخبرة التدريسية أو مهارة استخدام الحاسب عليه أن تكون قد أثرت على استخدامها للحاسب في تعليم اللغة

Tumour infiltrating CD25+ FoxP3+ regulatory T cells (Tregs) relate to tumour grade and stromal inflammation in oral squamous cell carcinoma

This research is aimed to quantitate and characterize the subtypes of tumour infiltrating lymphocytes (TILs), in particular the presence of FoxP3+ Tregs in different grades of oral squamous cell carcinoma using monospecific antibody staining of formalin-fixed, paraffin-embedded tissue sections. The correlation between tumour grade and the intensity of tumour infiltrating lymphocytes was tried to be tested, to assume a putative linkage between them. Thirty-four cases of histologically proven primary oral squamous cell carcinoma (OSCC) of different grades of differentiation were assorted to groups 1–3. Three-micron sections of tissue were cut and captured on electrically charged slides (Vision BioSystem, Mount Waverley, Australia) and stained using monospecific antibody against FoxP3+ Treg phenotype (dilution 1:40, Mouse monoclone No: 236A/E7, Ab 20034, IgG1; Abcam, Cambridge, UK). Automated protocols were employed for staining and scoring of staining intensity using Bond™ system (Vision BioSystem). Significant difference in staining intensities (Tregs) was noted among the histologic grades of tumour, where well-differentiated OSCC had significantly low expression of FoxP3+ Tregs in comparison with moderately and poorly differentiated tumours. A significant linear correlation was established between tumour grade and the intensity of TILs, where high grade tumours (poor differentiation) were more markedly infiltrated. There was also a significant positive correlation between FoxP3+ Tregs and TILs in cases studied. The correlation of these three variables noted in the study (FoxP3+ Tregs, tumour grade and TILs) and their significance in a meta-analysis may prove useful in targeting patients with high-risk neoplasms for more aggressive treatment protocols and management strategies.King Saud Universit

Integrated Control Channel Mechanism for Efficient Channel Utilization in TDMA for WLAN Networks

In this paper we introduced a custom TDMA MAC Layer Protocol. The main idea which actuated the research was to simulate a complex MAC Protocol in a wireless environment and espy its behavior under different physical, traffic, and network configurations. The TDMA protocol itself is completely custom and not based on any one particular industry specification. Our approach is ideal for exchanging data and control information in Mobile Ad hoc Networks (MANET) and wireless mesh networks so that resource needs (in terms of slot availability) of participating nodes can be rapidly accommodated for Quality of Service (QoS) guarantees. The approach described in this paper allow an efficient resource allocation strategy such that each participating node can converge to a consistent TDMA control slot usage that is optimum for the topology and resource demand of a dynamic wireless network environment and then we further proceeded with capacity planning for such networks based on the optimum control slot usage

Soft Vector Quantization with Inverse Power-Function Distributions for Machine Learning Applications

This paper discusses the positive impact of soft vector quantization on the performance of machine-learning systems that include one or more vector quantization modules. The most impactful gains here are avoiding over-fitting and boosting the robustness of such systems in the presence of considerable parasitic variance; e.g. noise, in the runtime inputs. The paper then introduces a soft vector quantization scheme with inverse power-function distributions, and analytically derives an upper bound of its relative quantization noise energy to that of typical (hard-deciding) vector quantization. This relative noise is expressed as a closed-form function of the power in order to allow the selection of its optimal values of that compromise both a soft enough vector quantization with a stable performance via small enough relative quantization noise. Finally, we present empirical evidence obtained via experimenting with two versions of the best reported OCR system for cursive scripts - that happened to deploy discrete HMMs - one version with hard vector quantization and the other with our herein presented soft quantization. Test samples of real-life scanned Arabic text pages are used to challenge both versions; hence the recognition error margins are compared

الوقف والإعلام

أولاً: تمهيد: أولاً: معنى الوقف لغة واصطلاحاً: معنى الوقف في اللغة: الحبس، مصدر: وقف يقف. يقال: وقفت الدار للمساكين وقفاً، ووقفت الدابة، أي حبستها. ولا يقال: أوقفت فهي لغة رديئة. قال الجوهري: وليس في الكلام أوقفت إلا حرف واحد: أوقفت عن الأمر الذي كنت فيه، أي أقلعت. وقال ابن فارس: ولا يقال في شيء: أوقفت إلا أنهم يقولون للذي يكون في شيء ثم ينزع عنه: قد أوقف. أ. هـ. وأما في الاصطلاح: فقد اختلفت عبارات الفقهاء في تعريف الوقف، تبعاً لاختلافهم في المذاهب من حيث الشروط والأركان، وإليك بعض التعريفات على المذهب الأربعة: المذهب الحنفي: عرفه المرغيناني بأنه: حبس العين على حكم ملك الله سبحانه وتعالى والتصدق بالمنفعة. المذهب المالكي: جاء في أقرب المسالك أنه جعل منفعة مملوك ولو بأجرة، أو غلته لمستحقه بصيغة، مدة ما يراه المحبس. أ. هـ. المذهب الشافعي: عرفه الرملي بأنه حبس مال يمكن الانتفاع به مع بقاء عينه بقطع التصرف في رقبته على مصرف مباح موجود. أ. هـ . المذهب الحنبلي: عرفه ابن قدامة بأنه: تحبيس الأصل، وتسبيل الثمرة، وهذا التعريف مأخوذ من قول المصطفى صلى الله عليه وسلم لعمر رضي الله عنه حبس الأصل وسبل الثمرة