Relay selection for multiple access relay channel with decode-forward and analog network coding

This paper presents a relay selection for decode-and-forward based on network coding (DF-NC) and analog-NC protocols in general scheme of cellular network system. In the propose scheme the two source node simultaneously transmit their own information to all the relays as well as the destination node, and then, a single relay i.e. best with a minimum symbol error rate (SER) will be selected to forward the new version of the received signal. Simulation results show that, the DF-NC scheme with considerable performance has exactness over analog-NC scheme. To improve the system performance, optimal power allocation between the two sources and the best relay is determined based on the asymptotic SER. By increasing the number of relays node, the optimum power allocation achieve better performance than asymptotic SER.Comment: 11 pages, 5 figures; International Journal of Distributed and Parallel Systems (IJDPS) Vol.3, No.2, March 201

First principles investigation of ferroelectricity in epitaxially strained Pb2_2TiO4_4

The structure and polarization of the as-yet hypothetical Ruddlesden-Popper compound Pb$_2$TiO$_4$ are investigated within density-functional theory. Zone enter phonons of the high-symmetry K$_2$NiF$_4$-type reference structure, space group $I4/mmm$, were calculated. At the theoretical ground-state lattice constants, there is one unstable infrared-active phonon. This phonon freezes in to give the $I2mm$ ferroelectric state. As a function of epitaxial strain, two additional ferroelectric phases are found, with space groups $I4mm$ and $F2mm$ at compressive and tensile strains, respectively.Comment: 4 pages, 4 figure

Analysis of CD38 and ZAP70 mRNA expression among cytogenetic subgroups of Iranian chronic-lymphocytic-leukemia patients

Chromosomal abnormalities and ZAP70 expression profile are two major independent prognostic markers in B-cell chronic lymphocytic leukemia. We investigated a possible correlation between these two markers. ZAP70 expression using real-time RT-PCR was examined in 20 B-cell chronic lymphocytic leukemia patients with del13q14, 13 patients with del11q22, 15 patients with trisomy 12, and 16 patients with no detected chromosomal abnormalities. Molecular analysis revealed that ZAP70 expression in the del13q subgroup was the same as in the control group, while it increased 2.78-fold in the del11q subgroup and 2.95-fold in the trisomy 12 subgroup, compared to the 15 cases in the control group. Comparison of the mean and standard deviation of the ZAP70 expression profile within the subgroups showed it to be highly variable among the individuals of the del11q and trisomy 12 subgroups, versus tight clustering for the del13q subgroup. Therefore, there is a correlation between del13q aberration, which has good prognosis with normal levels of ZAP70 expression. Due to a high degree of variation, no conformity is seen for del11q and trisomy 12 subgroups, making this grouping poor for prognostic discrimination. As a result, neither of these markers can serve as sole discriminators to determine the course of the disease; the use of both markers improves prognostic assessment

Hemodynamics optimization during off-pump coronary artery bypass: the ‘no compression' technique

Objective: Heart manipulation during OPCAB may cause hemodynamical instability in particular for access to the posterior and lateral walls. The ‘no compression' technique involves enucleation of the heart without any compression on the cavities, and stabilization of the target area with a suction device. The impact of this technique on hemodynamics is assessed. Methods: In order to analyze a homogeneous group, 26 consecutive patients with triple grafts, one to each side of the heart in the same sequential order (posterior, lateral and anterior wall successively) were selected. Heart rate (HR), mean pulmonary arterial pressure (PAP, mmHg), pulmonary capillary wedge pressure (PCWP, mmHg), mean arterial pressure (MAP, mmHg), cardiac output index (COI, l/min per m2), and central venous saturation (SvO2,%) were monitored. A coronary shunt was used for all the anastomoses. Results: HR was stable with baseline value of 60±10 and the highest value for the anterior wall, 63.6±8 (P=0.23). PAP and PCWP exhibited their highest increase, when compared with baseline, for the lateral wall, 23.9±4.7 vs. 20.7±6.2 (P=0.06), and 17.2±4.7 vs. 14.9±5.6 (P=0.16), respectively. MAP, COI and SvO2, exhibited their largest drop, when compared with baseline, for the lateral wall too, 73.1±9.1 vs. 77.1±7.5 (P=0.12), 1.99±0.47 vs. 2.26±0.55 (P=0.09), and 70.5±8.4 vs. 74.8±9.3 (P=0.12), respectively. Conclusions: None of the hemodynamical parameter differed significantly from baseline value for all three territories. While hemodynamics was perfectly maintained during the posterior and anterior walls revascularization, exposure of the lateral wall led to marginal changes onl

What doesn't kill you makes you stranger: Dipeptidyl peptidase-4 (CD26) proteolysis differentially modulates the activity of many peptide hormones and cytokines generating novel cryptic bioactive ligands

Dipeptidyl peptidase 4 (DPP4) is an exopeptidase found either on cell surfaces where it is highly regulated in terms of its expression and surface availability (CD26) or in a free/circulating soluble constitutively available and intrinsically active form. It is responsible for proteolytic cleavage of many peptide substrates. In this review we discuss the idea that DPP4-cleaved peptides are not necessarily inactivated, but rather can possess either a modified receptor selectivity, modified bioactivity, new antagonistic activity, or even a novel activity relative to the intact parent ligand. We examine in detail five different major DPP4 substrates: glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), peptide tyrosine-tyrosine (PYY), and neuropeptide Y (NPY), and stromal derived factor 1 (SDF-1 aka CXCL12). We note that discussion of the cleaved forms of these five peptides are underrepresented in the research literature, and are both poorly investigated and poorly understood, representing a serious research literature gap. We believe they are understudied and misinterpreted as inactive due to several factors. This includes lack of accurate and specific quantification methods, sample collection techniques that are inherently inaccurate and inappropriate, and a general perception that DPP4 cleavage inactivates its ligand substrates. Increasing evidence points towards many DPP4-cleaved ligands having their own bioactivity. For example, GLP-1 can work through a different receptor than GLP-1R, DPP4-cleaved GIP can function as a GIP receptor antagonist at high doses, and DPP4-cleaved PYY, NPY, and CXCL12 can have different receptor selectivity, or can bind novel, previously unrecognized receptors to their intact ligands, resulting in altered signaling and functionality. We believe that more rigorous research in this area could lead to a better understanding of DPP4’s role and the biological importance of the generation of novel cryptic ligands. This will also significantly impact our understanding of the clinical effects and side effects of DPP4-inhibitors as a class of anti-diabetic drugs that potentially have an expanding clinical relevance. This will be specifically relevant in targeting DPP4 substrate ligands involved in a variety of other major clinical acute and chronic injury/disease areas including inflammation, immunology, cardiology, stroke, musculoskeletal disease and injury, as well as cancer biology and tissue maintenance in aging

Infestation of the Longhorned Beetles Species (Cerambycidae) on Acacia mellifera (Vahl) Benth in the Gum Arabic Belt of Sudan

The Acacia mellifera (Vahl) Benth, (family Mimosaceae); namely kitr in Arabic, is a multipurpose tree in Sudan. The economic damage is often difficult to judge due to no enough research attention, moreover, the ecological knowledge is still scarce. Due to lack of forest entomology information of some Acacia species in Sudan, including the mellifera, the current objectives of this study are to characterize the infestation of Acacia mellifera by the insect's pest under study severely infesting other Acacia. Thus, a field study that was conducted in May-July 2007 in Kordofan region (Sudan) to assess infestation characteristics depending on the methods of sampling insects from trees and the insect damage and sign categories described by some investigators and tree measurements triggering infestation (e.g. crown size, and diameter, tree age, and height, and diameter at breast height). The results indicate the presence of holes of infestation in all directions of the tree trunk, with the exception of the north direction. Infestation rates ranged from zero to 26.68% on the study sites (n =2). It could be recommended that longhorned beetles need more ecological research

Ecological Investigation on Acacia senegal, Sudan

Farmers in Northern Kordofan State rely on the Acacia senegal tree, which yields gum Arabic, for a significant portion of their income. As a result, the study attempted to identify and characterise a globally important pest insect group: longhorned beetles, as well as other elements that affect tree health. This research was conducted in three study sites, and was held during the 2007-2008 season. The data was analyzed using logistic regression. Tree age was verified as a predictor variable by 91.1%; this study findings recommended for tree management and sustainability

Perceptions of the effectiveness of Kuwait’s strategic education planning policy and processes

Education planning is considered a vital factor in the success of any education system. For educational organisations such as the Ministry of Education (MoE) in Kuwait, strategic planning is very crucial for the achievement of the educational goals that reflect the aspirations of Kuwait’s community, such as preparing graduates to help develop their countries. However, there is a need to build a strategic education plan that integrates the goals and objectives from the educational field, as well as from society. The main purpose of this research is to explore the current strategic education plan in Kuwait in terms of the issues that may arise from the policies that control the strategic education plan’s formulation and implementation. This research adopted a mixed methods approach for data collection, which was conducted in three phases. The first phase depended on exploratory interviews to investigate the nature of the current policy that controls the education system in Kuwait. In addition, the exploratory study aimed to identify issues (if any) result from policies that control strategic education plan’s formulation and implementation. The second phase employed a questionnaire that explored research participants’ perceptions regarding the issues that were identified by the exploratory study. The third phase depended on in-depth interviews to investigate the characteristics of the centralisation policy in the education system. This phase aimed to further investigate the interviewees’ perceptions regarding the issues that had been identified in the first phase. The third phase also sought to investigate how the MoE’s policies might underlie these issues, and they may act strengths or weaknesses in the strategic education plan. The research sample of the three phases consisted of leaders from the three managerial tiers of the Kuwaiti education system (MoE officials, district leaders, and school leaders). The MoE leaders are those who chair different departments within the ministry. The district leaders are those who chair different departments within six education districts in Kuwait. The school leaders consist of head teachers, deputy heads, and department heads. The first phase involved 12 interviewees, the second phase involved 188 participants, and the third phase involved 22 interviewees. The research findings identified the current policy that controls the education system in Kuwait. The findings indicated that the centralisation in education system is extreme, and that the MoE is the ultimate decision maker. The MoE adopts the tenets of centralisation in order to control resource allocation, curriculum planning, in-service programmes for teachers and staff, pupils’ assessments, and educational planning. My research identified seven issues associated with strategic education planning in Kuwait, which are all affected by the centralisation policy, as follows: 1. Efficiency and effectiveness of the strategic plan 2. Comprehensiveness of the strategic plan 3. Implementability 4. Collaborativeness and participativeness 5. Communicative capacity 6. Bureaucratisation 7. Work environment These seven issues are seen as the problems that have resulted from the centralised nature of the strategic plan that affected the education system’s outcome. For each issue, the research results identified a number of reasons as to why these issues can be viewed as weaknesses of the centralised strategic plan. Thus, the research found that the centralisation policy, which is embedded in both the formulation and the implementation of the strategic plan, is an obstacle to the strategic plan’s effectiveness. Additionally, the research identified a relationship between the weaknesses of the strategic plan itself, and the MoE officials’ practices as the ultimate decision makers. Finally, the research concluded that the implementers of the strategic plan tend to participate in decision-making; however, they should exercise a certain degree of autonomy within their workplace in order to identify the best ways through which to achieve the goals of the strategic plan

A novel, highly sensitive and specific biomarker for Niemann-Pick type C1 disease

Background Lysosomal storage disorders (LSDs), are a heterogeneous group of rare disorders caused by defects in genes encoding for proteins involved in the lysosomal degradation of macromolecules. They occur at a frequency of about 1 in 5,000 live births, though recent neonatal screening suggests a higher incidence. New treatment options for LSDs demand a rapid, early diagnosis of LSDs if maximal clinical benefit is to be achieved. Methods Here, we describe a novel, highly specific and sensitive biomarker for Niemann-Pick Type C disease type 1 (NPC1), lyso-sphingomyelin-509. We cross-validate this biomarker with cholestane-3β,5α,6β-triol and relative lysosomal volume. The primary cohort for establishment of the biomarker contained 135 NPC1 patients, 66 NPC1 carriers, 241 patients with other LSDs and 46 healthy controls. Results With a sensitivity of 100.0% and specificity of 91.0% a cut-off of 1.4 ng/ml was established. Comparison with cholestane-3β,5α,6β-triol and relative acidic compartment volume measurements were carried out with a subset of 125 subjects. Both cholestane-3β,5α,6β-triol and lyso-Sphingomyelin-509 were sufficient in establishing the diagnosis of NPC1 and correlated with disease severity. Conclusion In summary, we have established a new biomarker for the diagnosis of NPC1, and further studies will be conducted to assess correlation to disease progress and monitoring treatment

Review of Gum Arabic Production Stability and Fluctuation, Sudan

The current paper reviewed the history of gum production in Sudan. Gum Arabic is an Acacia senegal exudate as defined by the FAO/WHO Joint Expert Committee for Food Additives. Sudan is the world's largest producer and exporter, contributing 80 to 90% of the world’s supply of this commodity. During the past 30 years production in Sudan shows alarming signs of overall decrease and also a substantial year-to-year variation in addition during the 1990’s world exports have started to pick momentum again, however, exports from Sudan almost remained the same, due to stagnating production in Sudan as well as the growing competition of other exporters