Collapse and physical properties of native and pre-steamed Eucalyptus Camaldulensis Eucalyptus Saligna wood from Tunisa

Eucalyptus is the second major wood species used for Tunisian reforestation since 1957, and they are found around the country in several arboretums. Eucalyptus may be an interesting raw material to the Tunisian wood industry. The main obstacle to its industrial exploitation is its natural propensity to incur internal checking, collapse and a high transverse shrinkage during industrial drying process. This study focused on the physical and mechanical properties of reforested Eucalytus saligna and Eucalyptus camaldulensis from the north west of Tunisia. Moisture content, densities, shrinkages and mechanical properties were determined. Then, the impact of pre-steaming on the physical properties of modified wood was investigated. The results showed that both Eucalyptus possess low dimensional stability and mechanical properties compared to other Eucalyptusspecies from Tunisia, Morocco, Australia and Brazil. These wood characteristics were mainly due to their low density and sensitivity to collapse reactions, occurred during drying. Pre-steaming process reduced Eucalyptswood moisture content, changing the wood permeability and resulting in a residual collapse recovery and a decrease in wood shrinkage. Pre-steaming treated E. camaldulensis and E. saligna wood could be valuable as furniture and/or structural material without being submitted to moisture content variation

Which diameter and angle rule provides optimal flow patterns in a coronary bifurcation?

The branching angle and diameter ratio in epicardial coronary artery bifurcations are two important determinants of atherogenesis. Murray's cubed diameter law and bifurcation angle have been assumed to yield optimal flows through a bifurcation. In contrast, we have recently shown a 7/3 diameter law (HK diameter model), based on minimum energy hypothesis in an entire tree structure. Here, we derive a bifurcation angle rule corresponding to the HK diameter model and critically evaluate the streamline flow through HK and Murray-type bifurcations. The bifurcations from coronary casts were found to obey the HK diameter model and angle rule much more than Murray's model. A finite element model was used to investigate flow patterns for coronary artery bifurcations of various types. The inlet velocity and pressure boundary conditions were measured by ComboWire. Y-bifurcation of Murray type decreased wall shear stress-WSS (10%-40%) and created an increased oscillatory shear index-OSI in atherosclerosis-prone regions as compared with HK-type bifurcations. The HK-type bifurcations were found to have more optimal flow patterns (i.e., higher WSS and lower OSI) than Murray-type bifurcations which have been traditionally believed to be optimized. This study has implications for changes in bifurcation angles and diameters in percutaneous coronary intervention

Higher frequencies of BCRP+ cardiac resident cells in ischaemic human myocardium

Aims Several cardiac resident progenitor cell types have been reported for the adult mammalian heart. Here we characterize their frequencies and distribution pattern in non-ischaemic human myocardial tissue and after ischaemic events. Methods and results We obtained 55 biopsy samples from human atria and ventricles and used immunohistological analysis to investigate two cardiac cell types, characterized by the expression of breast cancer resistance protein (BCRP)/ABCG2 [for side population (SP) cells] or c-kit. Highest frequencies of BCRP+ cells were detected in the ischaemic right atria with a median of 5.40% (range: 2.48-11.1%) vs. 4.40% (1.79-7.75%) in the non-ischaemic right atria (P = 0.47). Significantly higher amounts were identified in ischaemic compared with non-ischaemic ventricles, viz. 5.44% (3.24-9.30%) vs. 0.74% (0-5.23%) (P = 0.016). Few numbers of BCRP+ cells co-expressed the cardiac markers titin, sarcomeric α-actinin, or Nkx2.5; no co-expression of BCRP and progenitor cell marker Sca-1 or pluripotency markers Oct-3/4, SSEA-3, and SSEA-4 was detected. C-kit+ cells displayed higher frequencies in ischaemic (ratio: 1:25 000 ± 2500 of cell counts) vs. non-ischaemic myocardium (1:105 000 ± 43 000). Breast cancer resistance protein+/c-kit+ cells were not identified. Following in vitro differentiation, BCRP+ cells isolated from human heart biopsy samples (n = 6) showed expression of cardiac troponin T and α-myosin heavy-chain, but no full differentiation into functional beating cardiomyocytes was observed. Conclusion We were able to demonstrate that BCRP+/CD31− cells are more abundant in the heart than their c-kit+ counterparts. In the non-ischaemic hearts, they are preferentially located in the atria. Following ischaemia, their numbers are elevated significantly. Our data might provide a valuable snapshot at potential progenitor cells after acute ischaemia in vivo, and mapping of these easily accessible cells may influence future cell therapeutic strategie

Physical and thermal properties of microwave-dried wood lumber impregnated with phenol formaldehyde resin

In this study, microwave-dried oil palm trunk core lumber was impregnated with phenol formaldehyde resin using high pressure vacuum chamber. The impregnation of oil palm trunk core lumber was performed under 3 bar pressure and cured in an oven at 150°C for 2 h. The impregnation of oil palm trunk core lumber was carried out at different time intervals (15, 30, 60, 90, 120 min) to obtain different density lumber and compared with microwave-dried oil palm trunk core lumber and rubberwood. The physical and thermal properties of microwave-dried oil palm trunk core lumber, impregnated oil palm trunk core lumber and rubberwood were studied. In general, the impregnated oil palm trunk core lumber obtained better physical properties than microwave dried oil palm trunk core lumber but slightly lower than rubberwood. The thermal stability of oil palm trunk core lumber was analyzed by using thermogravimetric analysis and it shows that rubberwood exhibited better thermal stability than impregnated oil palm trunk core lumber

Factors Influencing the Effectiveness of Human Resource Training Programmes in Hotel Sector

Most hotels invest in implementing effective training programmes to maximize the inherent value of their existing human capital. However, it should be noted that the effectiveness of the programmes depends on whether trainees apply what they learned. This is a major concern among hotel operators. The main objective of this study is to explore the relationships between three influential factors which are work environment, individuals, and training process and the effectiveness of training programmes using Kirkpatrick evaluation model (1977). It is a correlation research using a mixed design of quantitative and qualitative methods. In the former method, a survey instrument was distributed to 297 participants who had attended and completed training programmes in five and four star hotels in ASEZA. The findings reveal that factors such as work environment, social support, the opportunity to perform and reward system, with the exception of organizational culture, influence and contribute to training effectiveness. Furthermore, ability and motivation of individual influence and contribute to training effectiveness with the exclusion of attitude. In addition. statistical analysis indicates that needs and design influence training effectiveness. All the factors demonstrate a positive correlation with training effectiveness and show a positive and significant relationship between them and training effectiveness. The qualitative method is used in the study in the form of a one-to-one interview using nine open-ended questions with human resource managers and training coordinators in the hotels. The findings support the outputs of the quantitative survey and consistent with previous studies except the organizational culture and the attitude. This study has contributed in bridging the gap concerning the influence by environment. individual and training process factors on the effectiveness of human resource training programmes. It also extends the literature of using the Kirkpatrick evaluation model (1977) to evaluate the effectiveness of training programmes particularly in Jordan. Finally, the study provides researchers with guidelines on conducting effective training programmes in the service sector

Causality and the semantics of provenance

Provenance, or information about the sources, derivation, custody or history of data, has been studied recently in a number of contexts, including databases, scientific workflows and the Semantic Web. Many provenance mechanisms have been developed, motivated by informal notions such as influence, dependence, explanation and causality. However, there has been little study of whether these mechanisms formally satisfy appropriate policies or even how to formalize relevant motivating concepts such as causality. We contend that mathematical models of these concepts are needed to justify and compare provenance techniques. In this paper we review a theory of causality based on structural models that has been developed in artificial intelligence, and describe work in progress on a causal semantics for provenance graphs.Comment: Workshop submissio

A Multi-Objective Bayesian Networks Approach for Joint Prediction of Tumor Local Control and Radiation Pneumonitis in Non-Small-Cell Lung Cancer (NSCLC) for Response-Adapted Radiotherapy

Purpose Individualization of therapeutic outcomes in NSCLC radiotherapy is likely to be compromised by the lack of proper balance of biophysical factors affecting both tumor local control (LC) and side effects such as radiation pneumonitis (RP), which are likely to be intertwined. Here, we compare the performance of separate and joint outcomes predictions for response‐adapted personalized treatment planning. Methods A total of 118 NSCLC patients treated on prospective protocols with 32 cases of local progression and 20 cases of RP grade 2 or higher (RP2) were studied. Sixty‐eight patients with 297 features before and during radiotherapy were used for discovery and 50 patients were reserved for independent testing. A multiobjective Bayesian network (MO‐BN) approach was developed to identify important features for joint LC/RP2 prediction using extended Markov blankets as inputs to develop a BN predictive structure. Cross‐validation (CV) was used to guide the MO‐BN structure learning. Area under the free‐response receiver operating characteristic (AU‐FROC) curve was used to evaluate joint prediction performance. Results Important features including single nucleotide polymorphisms (SNPs), micro RNAs, pretreatment cytokines, pretreatment PET radiomics together with lung and tumor gEUDs were selected and their biophysical inter‐relationships with radiation outcomes (LC and RP2) were identified in a pretreatment MO‐BN. The joint LC/RP2 prediction yielded an AU‐FROC of 0.80 (95% CI: 0.70–0.86) upon internal CV. This improved to 0.85 (0.75–0.91) with additional two SNPs, changes in one cytokine and two radiomics PET image features through the course of radiotherapy in a during‐treatment MO‐BN. This MO‐BN model outperformed combined single‐objective Bayesian networks (SO‐BNs) during‐treatment [0.78 (0.67–0.84)]. AU‐FROC values in the evaluation of the MO‐BN and individual SO‐BNs on the testing dataset were 0.77 and 0.68 for pretreatment, and 0.79 and 0.71 for during‐treatment, respectively. Conclusions MO‐BNs can reveal possible biophysical cross‐talks between competing radiotherapy clinical endpoints. The prediction is improved by providing additional during‐treatment information. The developed MO‐BNs can be an important component of decision support systems for personalized response‐adapted radiotherapy

Local Jordanian Materials to Produce a Bakelite-base Construction Composite Material

In this investigation, a combined experimental approach of micro-structural observation and compressive load capacity testing were followed to determine the behavior of bakelite matrix material reinforced with Jordanian silica sand. It was found that the reinforced samples gave a higher maximum load capacity than the pure matrix, because the homogeneous structure helped in distributing the applied load between the matrix and the reinforcement. Moreover, the higher the volume fraction of the reinforcement, the higher the maximum load capacity of the composite. The maximum load capacity of the samples with 75% content of Jordanian silica sand was less than that of pure bakelite. On the other hand, the higher the particle size of the reinforcement, the higher the maximum load capacity of the composite. Composites of bakelite matrix gave a higher maximum load capacity than that of polystyrene matrix. In addition, a longitudinal brittle fracture was observed for the composites

Flow injection analysis for the photometric determination of promethazine-HCl in pure and pharmaceutical preparation via oxidation by persulphate using Ayah 3SX3-3D solar micro photometer

The first flow injection spectrophotometric method is characterized by its speed and sensitivity which have been developed for the determination of promethazine-HCl in pure and pharmaceutical preparation. It is based on the in situ detection of colored cationic radicals formed via oxidation of the drug with sodium persulphate to pinkish-red species and the same species was determined by using homemade Ayah 3SX3-3D solar flow injection photometer. Optimum conditions were obtained by using the high intensive green light emitted diode as a source. Linear dynamic range for the absorbance versus promethazine-HCl concentration was 0-7 mmol.L-1, with the correlation coefficient (r) was 0.9904 while the percentage linearity (r2%) was 98.09%. the L.O.Q was 3.97 µg/sample, while L.O.D (S/N=3) = 0.2407µg/sample (5 µmol.L-1) from the stepwise dilution for the minimum concentration of lowest concentration in the linear dynamic range of the calibration graph. The R.S.D% at 2 mmol.L-1 promethazine-HCl is less than 1% (eight replicates) using 150 µL sample volume. Throughput 30 sample.hr-1. The method was applied successfully for the determination of promethazine-HCl in pharmaceutical preparation. By using paired t-test it was shown that there was no significant difference between the proposed method and official method and on that basis the new method can be accepted as an alternative analytical method

A Software Evolution Process Model: Analysis of Software Failure Causes

This paper presents a study on the degree of impact of several components on the evolvability of software systems. In particular, it focuses on failure rates, testing, and other factors which force the evolution of a software system. Also, it studies the evolution of software systems in the presence of various failure scenarios. Unlike previous studies based on the system dynamic (SD) model, this study is modeled on the basis of actor-network theory (ANT) of software evolution, using the system dynamic environment. The main index used in this study is the destabilization period after the recovery from any failure scenario. The results show that more testing and quick recovery after failure are keys to a fast system return to stability