bluuebunny/crossref_metadata_2025 huggingface dataset:
Peroxynitrite Electrochemical Quantification: Recent Advances and Challenges
Authors: Peteu Serban F. , Szunerits Sabine
Published: September 2013

Already established as a powerful nitrating, nitrosating and oxidative agent, peroxynitrite (product of nitric oxide reacting with superoxide radical, ONOO−; PON for short) was clinically ascertained as a potent cell‐death inducer in several devastating diseases. Herein, this clinical evidence is sketched purposely, to emphasize the vital need for PON in vivo detection, as are the strategies employed to develop ONOO− decomposition catalysts as potential therapies. A number of challenges are discussed next, on detecting PON ex vivo or in vivo. While ONOO− optical detection has been available for some time (e.g. oxidation of fluorescent probes, probe nitration, chemiluminescence), these methods tend to be indirect detection methods, elaborate, and rather difficult to apply for real‐time analyses. By contrast, electrochemical quantification of PON appears simpler, more convenient for direct, real‐time, label‐free measurements. Finally, several peroxynitrite‐sensitive interfaces and ways to confer selectivity are examined. However, one needs to be mindful of possible trade‐offs between specificity at a cost of slower response time, especially since ONOO− is a short‐lived species with a 1‐s lifetime. In particular, two recently published, interesting hybrid films are examined: the (hemin‐polythiophene) and the (reduced graphene oxide‐hemin) complex and the apparent significant augmentation in sensor response is further scrutinized.
Molecular interactions of Bcl-2 and Bcl-xL with mortalin: identification and functional characterization
Authors: Saxena Nishant , Katiyar Shashank P. , Liu Ye , Grover Abhinav , Gao Ran , Sundar Durai , Kaul Sunil C. , Wadhwa Renu
Published: September 2013

Bcl-2 family of proteins consists of both pro-apoptotic and anti-apoptotic members that control cellular apoptosis. They predominantly reside in the mitochondria and control the release of apoptotic factors from the mitochondria to the cytosol by regulating its membrane potential and opening the PT (permeability transition) pore. Here we report bioinformatics and biochemical evidence to demonstrate the interaction between Bcl-2 and Bcl-xL with a stress chaperone, mortalin. We demonstrate that such interaction results in the abrogation of mortalin-p53 interaction leading to nuclear translocation and transcriptional reactivation of p53 function that results in an induction of senescence in cancer cells.
Cation transport by the respiratory NADH:quinone oxidoreductase (complex I): facts and hypotheses
Authors: Steffen Wojtek , Steuber Julia
Published: September 2013

The respiratory complex I (electrogenic NADH:quinone oxidoreductase) has been considered to act exclusively as a H+ pump. This was questioned when the search for the NADH-driven respiratory Na+ pump in Klebsiella pneumoniae initiated by Peter Dimroth led to the discovery of a Na+-translocating complex in this enterobacterium. The 3D structures of complex I from different organisms support the idea that the mechanism of cation transport by complex I involves conformational changes of the membrane-bound NuoL, NuoM and NuoN subunits. In vitro methods to follow Na+ transport were compared with in vivo approaches to test whether complex I, or its individual NuoL, NuoM or NuoN subunits, extrude Na+ from the cytoplasm to the periplasm of bacterial host cells. The truncated NuoL subunit of the Escherichia coli complex I which comprises amino acids 1–369 exhibits Na+ transport activity in vitro. This observation, together with an analysis of putative cation channels in NuoL, suggests that there exists in NuoL at least one continuous pathway for cations lined by amino acid residues from transmembrane segments 3, 4, 5, 7 and 8. Finally, we discuss recent studies on Na+ transport by mitochondrial complex I with respect to its putative role in the cycling of Na+ ions across the inner mitochondrial membrane.
Role of cryo-ET in membrane bioenergetics research
Authors: Davies Karen M. , Daum Bertram
Published: September 2013

To truly understand bioenergetic processes such as ATP synthesis, membrane-bound substrate transport or flagellar rotation, systems need to be analysed in a cellular context. Cryo-ET (cryo-electron tomography) is an essential part of this process, as it is currently the only technique which can directly determine the spatial organization of proteins at the level of both the cell and the individual protein complexes. The need to assess bioenergetic processes at a cellular level is becoming more and more apparent with the increasing interest in mitochondrial diseases. In recent years, cryo-ET has contributed significantly to our understanding of the molecular organization of mitochondria and chloroplasts. The present mini-review first describes the technique of cryo-ET and then discusses its role in membrane bioenergetics specifically in chloroplasts and mitochondrial research.
Microbial hydrogen splitting in the presence of oxygen
Authors: Stein Matthias , Kaur-Ghumaan Sandeep
Published: September 2013

The origin of the tolerance of a subclass of [NiFe]-hydrogenases to the presence of oxygen was unclear for a long time. Recent spectroscopic studies showed a conserved active site between oxygen-sensitive and oxygen-tolerant hydrogenases, and modifications in the vicinity of the active site in the large subunit could be excluded as the origin of catalytic activity even in the presence of molecular oxygen. A combination of bioinformatics and protein structural modelling revealed an unusual co-ordination motif in the vicinity of the proximal Fe–S cluster in the small subunit. Mutational experiments confirmed the relevance of two additional cysteine residues for the oxygen-tolerance. This new binding motif can be used to classify sequences from [NiFe]-hydrogenases according to their potential oxygen-tolerance. The X-ray structural analysis of the reduced form of the enzyme displayed a new type of [4Fe–3S] cluster co-ordinated by six surrounding cysteine residues in a distorted cubanoid geometry. The unusual electronic structure of the proximal Fe–S cluster can be analysed using the broken-symmetry approach and gave results in agreement with experimental Mößbauer studies. An electronic effect of the proximal Fe–S cluster on the remote active site can be detected and quantified. In the oxygen-tolerant hydrogenases, the hydride occupies an asymmetric binding position in the Ni-C state. This may rationalize the more facile activation and catalytic turnover in this subclass of enzymes.
Improvement of mitochondrial function and dynamics by the metabolic enhancer piracetam
Authors: Stockburger Carola , Kurz Christopher , Koch Konrad A. , Eckert Schamim H. , Leuner Kristina , Müller Walter E.
Published: September 2013

The metabolic enhancer piracetam is used in many countries to treat cognitive impairment in aging, brain injuries, as well as dementia such as AD (Alzheimer's disease). As a specific feature of piracetam, beneficial effects are usually associated with mitochondrial dysfunction. In previous studies we were able to show that piracetam enhanced ATP production, mitochondrial membrane potential as well as neurite outgrowth in cell and animal models for aging and AD. To investigate further the effects of piracetam on mitochondrial function, especially mitochondrial fission and fusion events, we decided to assess mitochondrial morphology. Human neuroblastoma cells were treated with the drug under normal conditions and under conditions imitating aging and the occurrence of ROS (reactive oxygen species) as well as in stably transfected cells with the human wild-type APP (amyloid precursor protein) gene. This AD model is characterized by expressing only 2-fold more human Aβ (amyloid β-peptide) compared with control cells and therefore representing very early stages of AD when Aβ levels gradually increase over decades. Interestingly, these cells exhibit an impaired mitochondrial function and morphology under baseline conditions. Piracetam is able to restore this impairment and shifts mitochondrial morphology back to elongated forms, whereas there is no effect in control cells. After addition of a complex I inhibitor, mitochondrial morphology is distinctly shifted to punctate forms in both cell lines. Under these conditions piracetam is able to ameliorate morphology in cells suffering from the mild Aβ load, as well as mitochondrial dynamics in control cells.
IR signatures of the metal centres of bovine cytochrome c oxidase: assignments and redox-linkage
Authors: Dodia Raksha , Maréchal Amandine , Bettini Simona , Iwaki Masayo , Rich Peter R.
Published: September 2013

Assignments of IR bands of reduced minus oxidized IR difference spectra of bovine and related cytochrome c oxidases are reviewed and their linkages to specific metal centres are assessed. To aid this, redox-poised difference spectra in the presence of cyanide or carbon monoxide are presented. These ligands fix the redox states of either haem a3 alone or haem a3 and CuB respectively, while allowing redox cycling of the remaining centres.
Genetically encoding phenyl azide chemistry: new uses and ideas for classical biochemistry
Authors: Reddington Samuel , Watson Peter , Rizkallah Pierre , Tippmann Eric , Jones D. Dafydd
Published: September 2013

Introducing new physicochemical properties into proteins through genetically encoded Uaa (unnatural amino acid) incorporation can lead to the generation of proteins with novel properties not normally accessible with the 20 natural amino acids. Phenyl azide chemistry represents one such useful addition to the protein repertoire. Classically used in biochemistry as a non-specific photochemical protein cross-linker, genetically encoding phenyl azide chemistry at selected residues provides more powerful routes to post-translationally modify protein function in situ. The two main routes are modulation by light (optogenetics) and site-specific bio-orthogonal modification (bioconjugation) via Click chemistry. In the present article, we discuss both approaches and their influence on protein function.
Opportunities for bioprocess monitoring using FRET biosensors
Authors: Constantinou Antony , Polizzi Karen M.
Published: September 2013

Bioprocess monitoring is used to track the progress of a cell culture and ensure that the product quality is maintained. Current schemes for monitoring metabolism rely on offline measurements of samples of the extracellular medium. However, in the era of synthetic biology, it is now possible to design and implement biosensors that consist of biological macromolecules and are able to report on the intracellular environment of cells. The use of fluorescent reporter signals allows non-invasive, non-destructive and online monitoring of the culture, which reduces the delay between measurement and any necessary intervention. The present mini-review focuses on protein-based biosensors that utilize FRET as the signal transduction mechanism. The mechanism of FRET, which utilizes the ratio of emission intensity at two wavelengths, has an inherent advantage of being ratiometric, meaning that small differences in the experimental set-up or biosensor expression level can be normalized away. This allows for more reliable quantitative estimation of the concentration of the target molecule. Existing FRET biosensors that are of potential interest to bioprocess monitoring include those developed for primary metabolites, redox potential, pH and product formation. For target molecules where a biosensor has not yet been developed, some candidate binding domains can be identified from the existing biological databases. However, the remaining challenge is to make the process of developing a FRET biosensor faster and more efficient.
The superfamily of mitochondrial Complex1_LYR motif-containing (LYRM) proteins
Authors: Angerer Heike
Published: September 2013

Mitochondrial LYRM (leucine/tyrosine/arginine motif) proteins are members of the Complex1_LYR-like superfamily. Individual LYRM proteins have been identified as accessory subunits or assembly factors of mitochondrial OXPHOS (oxidative phosphorylation) complexes I, II, III and V respectively, and they play particular roles in the essential Fe–S cluster biogenesis and in acetate metabolism. LYRM proteins have been implicated in mitochondrial dysfunction, e.g. in the context of insulin resistance. However, the functional significance of the common LYRM is still unknown. Analysis of protein–protein interaction screens suggests that LYRM proteins form protein complexes with phylogenetically ancient proteins of bacterial origin. Interestingly, the mitochondrial FAS (fatty acid synthesis) type II acyl-carrier protein ACPM associates with some of the LYRM protein-containing complexes. Eukaryotic LYRM proteins interfere with mitochondrial homoeostasis and might function as adaptor-like ‘accessory factors’.
Electrode assemblies composed of redox cascades from microbial respiratory electron transfer chains
Authors: Gates Andrew J. , Marritt Sophie J. , Bradley Justin M. , Shi Liang , McMillan Duncan G.G. , Jeuken Lars J.C. , Richardson David J. , Butt Julea N.
Published: September 2013

Respiratory and photosynthetic electron transfer chains are dependent on vectorial electron transfer through a series of redox proteins. Examples include electron transfer from NapC to NapAB nitrate reductase in Paracoccus denitrificans and from CymA to Fcc3 (flavocytochrome c3) fumarate reductase in Shewanella oneidensis MR-1. In the present article, we demonstrate that graphite electrodes can serve as surfaces for the stepwise adsorption of NapC and NapAB, and the stepwise adsorption of CymA and Fcc3. Aspects of the catalytic properties of these assemblies are different from those of NapAB and Fcc3 adsorbed in isolation. We propose that this is due to the formation of NapC–NapAB and of CymA–Fcc3 complexes that are capable of supporting vectorial electron transfer.
Methods to analyse composition and dynamics of macromolecular complexes
Authors: Heide Heinrich , Wittig Ilka
Published: September 2013

Macromolecular complexes are involved in a broad spectrum of cellular processes including protein biosynthesis, protein secretion and degradation, metabolism, DNA replication and repair, and signal transduction along with other important biological processes. The analysis of protein complexes in health and disease is important to gain insights into cellular physiology and pathophysiology. In the last few decades, research has focused on the identification and the dynamics of macromolecular complexes. Several techniques have been developed to isolate native protein complexes from cells and tissues to allow further characterization by microscopic and proteomic analysis. In the present paper, we provide a brief overview of proteomic methods that can be used to identify protein–protein interactions, focusing on recent developments to study the entire complexome of a biological sample.
Effects of retailer pressure on the efficiency of agricultural industries
Authors: Lean Ian J.
Published: September 2013

Considerable progress has been made in reducing starvation during the past century. This was achieved through increased use of arable land and adoption of new technologies. Future increases in food production will depend to a greater extent than in the past on the adoption of new technologies and must be even more rapidly achieved than in the past to meet the increase in demand for food. Intensive industries such as the poultry industry are under pressure from those engaged with a naturalistic fallacy. Technologies such as antibiotics for chickens or hormonal growth promotants (HGPs) for beef cattle that are safe for people, reduce environmental impacts of production, increase profits for producers, and improve animal well-being will be needed to achieve these increases in food production. The precedent set in the EU in banning HGPs can be understood as a response to the illegal abuse of diethylstilboestrol in the EU and as a non-tariff trade barrier to reduce the importation of beef from more efficient producers. The banning of antibiotics in the EU reflects the unwise application of a ‘precautionary principle’ through which risks were not soundly assessed. However, the unilateral ban established by Coles Supermarkets Pty Ltd on HGPs in Australia represents a more dangerous development, in which marketing ploys have been accorded a higher value than the care of animals, the environment, or the profit made by producers. Decisions such as these have reduced the viability of animal production in the UK and pose a threat to sustainable agricultural production in Australia.
Playback Theatre and Narrative Therapy: Introducing a New Model
Authors: Barak Adi
Published: September 2013

This article explores a new synthesis between Playback Theatre and Michael White's narrative therapy. Through an exploration of the two methods the article elaborates how such integration can be achieved and how it can contribute to the process of narrative re-authoring. The discussion also includes the limitations and possible drawbacks of such integration, for both playback theatre and narrative therapy. Finally, a structured therapeutic model integrating White's approach to narrative change with Playback Theatre techniques is detailed.
Role Playing a Squiggle: An Adaption of Winnicott's Squiggle Game for Dramatherapy
Authors: Evans Deborah
Published: September 2013

Children are often the vehicle for psychological material that does not belong to them, ghost traumas or ways of being that are not theirs, but are projected into their lives by parents and past generations. This ‘research in action’ summarises some work on a case of a 10-year-old girl where the creativity and playful aspect of the therapist were essential tools for finding the true potential of the patient in treatment.

In this particular case Winnicott's squiggle game was used and the concept furthered with various techniques of enactments, story building, and poetry. The aim was to open up the potential self of the patient by regressing to an earlier stage of play.

Although some hesitate to use their own associations for fear of trampling on the image enactments and stories of the patient, the spontaneity and playful self of the therapist is, nevertheless, often the key to unlocking the true potential. This way of working may be helpful for children or adults that appear cut off from a deeper connection with life.
Baseline Measure of Alcohol-Based Skin Preparation Agents before 2011 National Quality Forum Recommendation in a General Surgery Population
Authors: Talsma AkkeNeel , Galecki Andrzej , Chenoweth Carol E. , Geun HyoGeun , Campbell Darrell A.
Published: September 2013

The National Quality Forum (2011) recommends the use of alcohol-based skin preparation agents before surgery to help prevent infections. This multihospital study (n = 3,794) evaluates its use in a general surgery patient population before the National Quality Forum recommendation. Forty-seven percent of cases received an alcohol-based skin preparation agent.
A computable figure of merit for quasi-Monte Carlo point sets
Authors: Matsumoto Makoto , Saito Mutsuo , Matoba Kyle
Published: September 2013

Let

P

⊂
[
0
,
1

)
S

\mathcal {P} \subset [0,1)^S

be a finite point set of cardinality

N
N

in an

S
S

-dimensional cube, and let

f
:
[
0
,
1

)
S

→

R

f:[0,1)^S \to \mathbb {R}

be an integrable function. A QMC integral of

f
f

by

P

\mathcal {P}

is the average of values of

f
f

at each point in

P

\mathcal {P}

, which approximates the integral of

f
f

over the cube. Assume that

P

\mathcal {P}

is constructed from an

F

2

\mathbb {F}_2

-vector space

P
⊂
(

F

2
n

)
S

P\subset (\mathbb {F}_2^n)^S

by means of a digital net with

n
n

-digit precision. As an

n
n

-digit discretized version of Josef Dick’s method, we introduce the Walsh figure of merit (WAFOM)

W
A
F
O
M

(
P
)

{\mathrm {WAFOM}}(P)

of

P
P

, which satisfies a Koksma-Hlawka type inequality, namely, QMC integration error is bounded by
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper C Subscript upper S comma n Baseline StartAbsoluteValue EndAbsoluteValue f StartAbsoluteValue EndAbsoluteValue Subscript n Baseline normal upper W normal upper A normal upper F normal upper O normal upper M left-parenthesis upper P right-parenthesis">

C

S
,
n

|

|

f

|

|

n

W
A
F
O
M

(
P
)

C_{S,n}||f||_n {\mathrm {WAFOM}}(P)

under

n
n

-smoothness of

f
f

, where

C

S
,
n

C_{S,n}

is a constant depending only on

S
,
n

S,n

.

We show a Fourier inversion formula for

W
A
F
O
M

(
P
)

{\mathrm {WAFOM}}(P)

which is computable in

O
(
n
S
N
)

O(n SN)

steps. This effectiveness enables us to do a random search for

P
P

with small value of

W
A
F
O
M

(
P
)

{\mathrm {WAFOM}}(P)

, which would be difficult for other figures of merit such as discrepancy. From an analogy to coding theory, we expect that a random search may find better point sets than mathematical constructions. In fact, a naïve search finds point sets

P
P

with small

W
A
F
O
M

(
P
)

{\mathrm {WAFOM}}(P)

. In experiments, we show better performance of these point sets in QMC integration than widely used QMC rules. We show some experimental evidence on the effectiveness of our point sets to even nonsmooth integrands appearing in finance.
Antimicrobial Activity of Actinomycetes Isolated from Paya Maga, Sarawak
Authors: Han Ng Yik Han , Yi Ting Jen , Chia Yeo Tiong
Published: September 2013

A study was carried out to evaluate the antimicrobial activity of 51 actinomycetes strains isolated from environmental samples collected during an expedition at Paya Maga, located in Ulu Trusan, Lawas, Sarawak. These actinomycetes strains were isolated from 20 soil and 15 plant samples. Their ability to inhibit the growth of Gram positive bacteria (Staphylococcus aureus, Micrococcus luteus), Gram negative bacteria (Escherichia coli) and yeast (Saccharomyces cerevisiae) were tested by using co-culture method. Twenty five percent of the isolates (13 out of 51) were active against at least one bacteria or one yeast standard strain while 18 (35%) were active against at least two standard strains, indicating broad spectrum activities. The results also showed that 23% (7 strains) of the positive isolates with single or broad spectrum activities were able to show better result in comparison to 100 mg/L of Chloramphenicol and Nystatin used (by forming inhibition zone more than 20 mm in diameter). The 31 inhibitory strains were sequenced and partial 16S rDNA sequences were derived for taxonomic identification. The majority of these strains (27 out of 31) belong to the family of Streptomycetaceae, followed by 2 strains from Streptosporangiaceae and 1 strain each from Nocardiaceae and Pseudonocardiaceae. Sixteen of the isolates can only be classified up to the genus level so they are potentially novel species which are targets for further study to isolate antimicrobial agents.
Pretreatment of Oil Palm Fronds for Improving Hemicelluloses Content for Higher Recovery of Xylose
Authors: M. S. Siti Sabrina, , A. R. Roshanida, , N. Norzita,
Published: September 2013

Lignocelluloses material is known as a potential biomass for conversion into value-added product. Utilization of biomass for beneficial products particularly food and health-related, has gained increasing attention among researchers worldwide and the potential usage of the lignocelluloses biomass is much sought after nowadays. An oil palm frond (OPF) has a great potential to be used as a precursor for production of xylose. In order to increase the yield of xylose, pretreatment of lignocelluloses biomass is important as it will for example, enhance the accessibility of enzyme to convert hemicelluloses xylan into xylose. Therefore in this study, OPF was pre-treated using dilute acid hydrolysis (H2SO4), alkali (NaOH), and autohydrolysis methods. The result showed that autohydrolysis gave higher hemicelluloses content which was 27.80±0.35% as compared to alkali and dilute acid pretreatment with 17.51±0.61% and 27.37±1.89%, respectively.  The autohydrolysis pretreated samples were then used for further enzymatic hydrolysis for xylan breakdown into xylose. Recovery of xylose was found to be higher at higher xylanase activity which was16 U.  Reaction time of 48 h with 1% substrate was able to produce up to 0.795 g/L xylose.
Phylogenetic Abnalysis of Malaysian Pineapples Cultivars Based on the DNA Sequence of the Internal Transcribed Spacer Region
Authors: Hidayat Topik , Chandrika K. , Farah Izana A. , Azman S. A. , Alina W.
Published: September 2013

The phylogenetic study was conducted to determine the phylogenetic status and evolutionary relationships among the nine commercial pineapple cultivars using sequences of the internal transcribed spacer (ITS) region. Genomic DNA was extracted, and the ITS region was amplified and sequenced. Parsimony analysis revealed that Malaysian cultivars could be classified into two major groups based on the ITS region. The first group comprised of the cultivars Sarawak Green Local, Gandul, and N36 whereas the second group consisted of the cultivars Josapine, Yankee, Morris Bentanggur, Morris Gajah, MD2 and MD2/T. Several combinations of synapomorphic characters (leaf and fruit) support this classification system, suggesting the ITS region has the ability to determine the phylogenetic status and relationships of pineapple cultivars. Since each group has its own similar genetic pattern and presumably certain specific biochemical properties, the relationships of pineapple cultivars revealed in the phylogenetic tree can be used as a basis for successful hybridizations to generate new pineapple cultivars.
The Exterior Squares of Some Crystallographic Groups
Authors: Mat Hassim Hazzirah Izzati , Sarmin Nor Haniza , Mohd Ali Nor Muhainiah , Masri Rohaidah Masri , Mohd Idrus Nor’ashiqin Mohd Idrus
Published: September 2013

A crystallographic group is a discrete subgroup G of the set of isometries of Euclidean space En, where the quotient space En/G is compact. A specific type of crystallographic groups is called Bieberbach groups. A Bieberbach group is defined to be a torsion free crystallographic group. In this paper, the exterior squares of some Bieberbach groups with abelian point groups are computed. The exterior square of a group is the factor group of the nonabelian tensor square with the central subgroup of the group.
Thermoluminescence Performance of Carbon–doped Aluminium Oxide for Dose Measurement by Various Preparation Methods
Authors: Yong Leong Chuey , Wagiran Husin , Ismail Abd Khamim
Published: September 2013

Thermoluminescent dosimeter (TLD) of carbon–doped aluminium oxide (α–Al2O3:C) produced in the form of single crystals show high sensitivity to ionizing radiation (about 40–60 times higher than TLD–100 (LiF:Mg,Ti)). The present article offers a review of the materials preparation and corresponding thermoluminescence (TL) properties of α–Al2O3:C subjected to various types of ionizing radiations. Different methods of α–Al2O3:C preparation in form of single crystal and thin films are reviewed. The development of methods of preparation is based on the approaches that involve the evaluation of the luminescence light yield in TL process. Most of the methods used were suitable, but each of these methods has their advantages and disadvantages depending on the required form of materials. Considering the results presented by various authors, possible better method of material preparation is proposed. The potential alternative fabrication technique of α–Al2O3:C thin film by using radio–frequency magnetron sputtering is briefly discussed.
Software Quality Model for Telecommunication Industry in Malaysia
Authors: Abdul Hamid Nor Fazlina Iryani , Hasan Mohamad Khatim
Published: September 2013

Software metric and quality models play a pivotal role in measurement of software quality. A number of well-known quality models and software metrics are used to build quality software in industry. Most developers and majority of software users require some form of measure for the software system they are concerned with. Software quality measurement needs a quality model that is usable throughout the software lifecycle and that it embraces all the perspectives of quality. Software quality factors and attributes that form the quality model is derived from literature review and survey. Using those quality factors and attributes, software quality model for telecommunication industry is constructed by considering three distinctive but connected areas of interest, which are economic dimension, social dimension and technical dimension.
An Experimental Investigation on Thermal Conductivity of Lightweight Foamcrete for Thermal Insulation
Authors: Othuman Mydin Md Azree
Published: September 2013

Presently, the construction industry has shown considerable consciousness in utilizing lightweight foamcrete as a building material. The demand of lightweight foamcrete is becoming higher now where this material has increased many folds in recent years due to its intrinsic economies and advantages over conventional concrete in a range of structural and semi-structural applications. The major specialties of lightweight foamcrete are its excellent thermal conductivity, low self-weight, high impact resistance and good freeze thaw resistance. The aim of this experimental study is to investigate the thermal conductivity property of lightweight foamcrete with various densities. The main parameters that will be considered are density of lightweight foamcrete, the void size and porosity. The lightweight foamcrete samples are made with constant water-cement ratio of 0.5 and cement-sand ratio of 2:1. According to experimental results, lower densities lightweight foamcrete transforms to lower thermal conductivity values. Meanwhile, the density of lightweight foamcrete is controlled by the porosity where lower densities indicate larger porosity values. For this reason, thermal conductivity of lightweight foamcrete changes significantly with the porosity because air is the poorest conductor in comparison to solid and liquid owing its molecular constitution. The measured values of thermal conductivity should provide a useful database for evaluating the thermal performance of lightweight foamcrete structures.
Removal of Mercury (II) from Aqueous Solution by using Rice Residues
Authors: Song S. T. , Saman N. , Johari K. , Mat H. B.
Published: September 2013

Sorption potential of rice residues for Hg(II) removal from aqueous solution was investigated. Rice husk (RH) and rice straw (RS) were selected and treated with sodium hydroxide (NaOH). The raw and modified adsorbents were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and BET surface area measurements. The effects of pH, initial ion concentration, and agitation time on the removal process were studied in batch adsorption experiments. Two simple kinetic models, which are pseudo-first-order and pseudo-second-order, were tested to investigate the adsorption mechanisms. The kinetic data fits to pseudo second order model with correlation coefficients greater than 0.99 for all adsorbents. The equilibrium data fitted well with the Langmuir compared to Freundlich isotherm models. Alkali-treated adsorbent obtained larger surface area and RH-NaOH showed highest adsorption capacity followed by RS-Pure > RH-Pure > RS-NaOH. The maximum removal efficiency obtained by RH-NaOH and RS-Pure was 42 mg/l (80%) at pH 6.5 and with 2 days contact time (for 50 mg/l initial concentration and 25 mg adsorbents).
Pembentukan Karektor Pelajar Kreatif Mengikut Teori Sternberg: Suatu Analisis Kandungan dan Pembangunan Kerangka Konseptual
Authors: Rasul Mohamad Sattar , Ramli Nur Farhana Waheeda , Abd Rauf Rose Amnah
Published: September 2013

Kreativiti adalah merupakan satu kebolehan untuk melihat sesuatu dari pandangan yang baru serta keupayaan untuk melihat dan menyelesaikan sesuatu masalah dengan cara yang berbeza, yang belum pernah dicuba sebelum ini dan luar biasa. Ia menghubungkan pengalaman mental dan fizikal yang asli, unik dan berbeza. Seiring dengan era globalisasi yang semakin mencabar dan perkembangan teknologi yang semakin pesat membangun, pelajar yang mempunyai sifat kreativiti sangat diperlukan dalam masyarakat kita pada zaman ini. Kajian ulasan sistematik hasil daripada jurnal-jurnal terdahulu ini bertujuan untuk membangunkan satu kerangka konseptual mengenai pembentukan karektor pelajar yang kreatif. Faktor-faktor yang telah dikenalpasti ialah kepintaran, pengetahuan, gaya berfikir, personaliti, motivasi dan juga persekitaran. Faktor-faktor ini berdasarkan teori kreativiti Sternberg dan komponen kreativiti Amabile. Adalah penting bagi ibu bapa, guru dan pihak sekolah untuk mengetahui faktor yang menyumbang kepada karektor kreativiti pelajar.
Optimization of Injection Molding Parameters for WC-Co Feedstocks
Authors: M. Amin Sri Yulis , Muhamad Norhamidi , Jamaludin Khairur Rijal
Published: September 2013

This study investigates the effect of injection molding parameters on the density of green body of cemented carbide (WC-Co) – based powder injection molding (PIM) feedstock. Experiments were conducted with ball-milled WC-Co powder mixed with a palm stearin and polyethylene binder system. To minimize the test run while maintaining the quality standard of data measurement, design of experiment approach, particularly Taguchi Method with L18 orthogonal array was used in the present study. Several parameters were considered, namely, powder loading, injection temperature, holding pressure and injection rate, while density of the green body as the response factor. The results show the optimum combination of injection factor that produces the best green density value, which eventually will leads to higher density for sintered parts.
Perbezaan Upah Mengikut Jantina dan Diskriminasi Majikan dalam Sektor Teknologi Maklumat dan Komunikasi
Authors: Ismail Rahmah , Osman Zulkifly , A. Malek Syazwani
Published: September 2013

Artikel ini menganalisis perbezaan upah antara jantina dalam sektor swasta termoden di Malaysia, iaitu sektor teknologi maklumat dan komunikasi (ICT). Sektor ini dipilih kerana dalam sektor yang dianggap moden, canggih dan mempunyai maklumat lengkap, tindak tanduk majikan terhadap penggajian pekerja, terutama sekali dari segi penetapan upah, dijangka lebih rasional dan objektif. Analisis melibatkan dua peringkat. Pertama, menganggar model upah lelaki dan wanita berdasarkan model persekolahan Mincer (1974) bagi mengenal pasti faktor yang menentukan upah. Kedua, menghurai perbezaan upah jantina berasaskan kaedah penghuraian Blinder (1973). Analisis menggunakan data yang dikutip pada 2007/2008, mengandungi 347 pekerja peringkat profesional dan eksekutif dalam sektor ICT di Selangor dan Wilayah Persekutuan Kuala Lumpur. Hasil penganggaran mendapati pendidikan, latihan, tempat belajar dan kaum adalah signifikan dalam mempengaruhi upah lelaki dan upah wanita. Namun, penghuraian perbezaan upah menunjukkan perbezaan upah antara jantina yang disumbangkan oleh prasangka buruk majikan terhadap wanita atau disebut sebagai faktor diskriminasi agak tinggi, iaitu hampir mencecah 80 peratus. Implikasinya, tingkat kecanggihan sektor dan kesempurnaan maklumat tidak menjanjikan sikap atau prasangka majikan yang baik.
Effect of Zero Measurements in Rainfall Data
Authors: Suhaila Jamaludin , Ching-Yee Kong , Yusof Fadhilah , Hui-Mean Foo
Published: September 2013

Flood is a commonly occurring hazard in Malaysia. The climate change in combination with the sea level rise will affected the frequency of flood events especially in a tropical country like Malaysia. Many researches focused on modeling rainfall data have been carried out in Malaysia. However, most of the rainfall studies did not include the zero values. The importance of these zero measurements should be examined in order to increase the quality of the research. The main purpose of this paper is to study the effect of zero measurement in rainfall analysis by applying a mixed bivariate lognormal distribution. The inter-station correlation coefficient was calculated in three cases of datasets. The first case considered only the positive values at both stations, and the second case included the positive values at either one of the stations, while the third case considered all values including zeroes at both rainfall stations. It was found that only the cases considering the positive measurements are useful and valid for the characterization of rainfall fields in our analysis.
Non-Homogeneous Hidden Markov Model for Daily Rainfall Amount in Peninsular Malaysia
Authors: Tan Wei Lun , Yusof Fadhilah , Yusop Zulkifli
Published: September 2013

The non-homogeneous hidden Markov model (NHMM) generates the rainfall observation depends on few weather states which serve as a link between the large scale atmospheric measures. The daily rainfall at 20 stations from Peninsular Malaysia for 33 years sequences is analyzed using NHMM during the northeast monsoon season. A NHMM with six hidden states are identified. The atmospheric variable was obtained from NCEP Reanalysis Data as predictor. The gridded atmospheric fields are summarized through the principle component analysis (PCA) technique. PCA is applied to sea level pressure (SLP) to identify their principal spatial patterns co-varying with rainfall. The NHMM can accurately simulate the observed daily mean rainfall, correlations between stations for daily rainfall amounts and the quantile-quantile plots. It can be concluded that the NHMM is a useful method to simulate the daily rainfall amounts that may be used to prepare strategies and planning for the unpredicted disaster such as flood and drought.
Mediating Effect of Organisational Culture between Leadership Values on Innovation: A Partial Least Squares (PLS) Path-Modeling
Authors: Abdullah Mokhtar , Ab Hamid Mohd Rashid , Mustafa Zainol , Idris Fazli , Mohd Suradi Nur Riza
Published: September 2013

This exploratory study examined how leadership values affect innovation through organizational culture in organisations. A model of these relationships was created based on earlier research on value-based leadership and culture and a sample of 390 managers and personnel of Government-link companies in Malaysia. The model was assessed using Partial Least Squares (PLS) based Structural Equation Modeling (SEM). Analyses with the PLS technique confirmed all the hypotheses concerned. The results generally support significant relationships between leadership values, organisational culture and innovation. The study also confirmed the mediating role of organizational culture for the relationship between leadership values and innovation in organisations. The role of organizational culture is important for understanding how leadership values and innovation are related. The results of the study also suggest several aspects that may help organisations create conducive working environment supportive of innovation.
Indoor Overhead Video Camera for Efficient People Counting
Authors: Serrano-Cuerda Juan , Castillo José Carlos , Fernández-Caballero Antonio
Published: September 2013

This article introduces a system for real-time people counting. People counting systems are challenging in the surveillance domain. The proposed system is built from INT3-Horus, a multi-agent based framework for intelligent monitoring and activity interpretation. The system uses an indoor overhead video camera that detects people moving freely in a hall or room. The people counting system is flexible in detecting individuals as well as groups. Counting is independent of the trajectories and possible occlusions of the humans present in the scene. The initial results offered by the system are very promising in terms of specificity, sensitivity and F-score.
Including Gamification Techniques in the Design of TANGO: H Platform
Authors: González-Gonzáleza Carina S. , Toledo-Delgado Pedro , Padrón Miguel , Santos Elena , Cairos Mariana
Published: September 2013

This paper presents the design approach of TANGO:H (Tangible Goals: Health): a platform for the creation of physical and cognitive rehabilitation exercises. This platform is adaptable to the characteristics of the population it is intended: children hospitalized and in home care. Also, it is highly configurable and customizable, thanks to exercises editor: TANGO:H Designer. This feature allows health professionals and educators to create game-like exercises, adapted to the specific needs of end users and to the context in which the intervention will take place. Note that TANGO:H was designed for the recreational, educational and rehabilitation use for children at hospital. So, in order to improve the users’ experience with the platform and their engagement, several Gamification techniques has been included. This paper focused on the technical and gamification requirements of the design of TANGO:H.
Pro-Environmental Concern Among Primary School Students
Authors: Karpudewan Mageswary , Chee Keong Chin
Published: September 2013

Public awareness on environmental issues is the prerequisite of the behavioural changes towards environmental-friendly activities. People who are concern about preserving the environment for present and future generations are more prone to engage in pro-environment lifestyles. In this study, the modified New Ecological Paradigm (NEP) scale was used to gauge 348 students’ pro-environmental concern. Based on 1 to 5 Likert scale response, students’ pro-environmental values was found to be high (mean=3.66, SD=0.59). Data analysis showed no difference in students’ belief system across gender and between students in Penang and Perak states. However, there was variation in pro-environmental concern between schools. It was also revealed that students’ science achievement in school is a moderate-effect predictor of their pro-environmental concern.
Mathematical Thinking in Differential Equations Among Pre-Service Teachers
Authors: Zeynivandnezhad Fereshteh , Ismail Zaleha , Mohammad Yosuf Yudariah
Published: September 2013

Pre-service teachers should be equipped with mathematical thinking. Mathematical thinking is one of the most critical aims of the mathematics education has an extremely crucial role for enhancing then conceptual learning. Mathematical thinking is a process that enables students to expand the for the complexities of their ideas. This article describes mathematical thinking in differential equations among pre-service teachers. The study was carried out in the Faculty of Education, Universiti Teknologi Malaysia. A set of items was designed to test mathematical thinking level. The instrument was developed based on Mason's framework of mathematical thinking. Test items measure mathematical thinking namely, specializing, generalizing, conjecturing, and convincing. Descriptive statistics was applied for data analysis. The result indicated that students' mathematical thinking is in the low level mostly specializing. The implications of this research will lead to some recommendations and approaches to enhance mathematical thinking.
Learning Functions of Two Variables Based on Mathematical Thinking Approach
Authors: Kashefi Hamidreza , Ismail Zaleha , Mohammad Yusof Yudariah
Published: September 2013

Multivariable function is one of the most important concepts in the learning of advanced mathematics. We had implemented a teaching approach to support students in the learning of two-variable functions by promoting mathematical thinking in face-to-face Multivariable Calculus classroom. This study investigates the obstacles and difficulties faced by students in the learning of two-variable functions based on the mathematical thinking approach. The findings indicated that students displayed various difficulties in finding the range and sketching the graph of two-variable functions. The students’ difficulties and obstacles such as poor mastery of algebraic manipulation, poor grasp of prior knowledge or lack of it, idiosyncrasy attributed from previous mathematical experience, and restricted mental images of two-variable functions could be classified as difficulties with techniques, concepts, and studying mathematics. Based on students’ responses, the difficulties were considered mainly conceptual in nature and few were related to techniques and studying mathematics.
Goals of Science Education in the Tertiary Level: Assessment of the College of Science Faculty, University of Eastern Philippines
Authors: Rubenecia Marliza E.
Published: September 2013

The study determined the knowledge of the College of Science faculty on the goals of science education, the importance of each goal as perceived by the faculty, how often each goal is used and operationalized for teaching/learning purposes. The results revealed that teachers’ level of knowledge on the science goals and objectives was minimal. The faculty perceived scientific knowledge and methods very important and used it frequently in teaching. They used lecture for students to acquire scientific knowledge and laboratory activities to develop scientific methods. They did not know how to operationalize societal issues, personal needs, and career awareness when teaching their subject matter. The problems that prevent them from pursuing the goals were lack of instructional materials, lack of interest and negative attitude of students, lack of facilities, and knowledge in handling laboratory apparatus. Teachers do not utilize strategies that can facilitate the students’ construction of meaning and ideas.
Prediction of Financial Distress Companies in the Consumer Products Sector in Malaysia
Authors: Alifiah Mohd Norfian , Salamudin Norhana , Ahmad Ismail
Published: September 2013

This study attempts to predict financial distress companies in the consumer products sector in Malaysia using financial distress companies as the dependent variable and financial ratios as the independent variables. Logit Analysis was used as the analysis procedure because financial ratios do not have to be normal if it is used. It is also suitable when the dependent variable is binary in nature. Furthermore, it can also provide the probability of a company being financially distress. In addition, it can also provide us with the sign of the independent variable(s). This study found that the independent variables that can be used to predict financial distress companies in the consumer products sector in Malaysia were debt ratio, total assets turnover ratio and working capital ratio. The findings from the internal validation showed that the prediction model provided a more than 50% chance that the model is accurate for five years before distress. Furthermore, the findings from the external validation showed that the model might be able to be used outside the estimation time period because the overall percentage accuracy were higher than 50% for five years before distress.
Total Factor Productivity Growth Based on Resource and Non Resource Based Industries of the Manufacturing Sector, 2000-2005
Authors: Sulaiman Noorasiah , Fadzil Norfadila
Published: September 2013

This paper examines total factor productivity (TFP) growth in resource and non resource based industries of the Malaysian manufacturing sector. The growth in TFP is examined between 2000 and 2005. Unlike previous studies that use one source of data from Industrial Manufacturing Survey (IMS), this research combines two sources of data–Malaysian Input-Output Tables and IMS. The motivation for this study was brought about due to the need to present a different method for estimating TFP growth using the input-output methodology. The result from this study for resource and non resource based industries reveals that the TFP growth is relatively low for both industries. In addition, the major source of change in TFP of the both industries is contributed by intermediate inputs, while the contribution of labour and capital is substantially low.