bluuebunny/crossref_metadata_2025 huggingface dataset:
Premating isolation is determined by larval rearing substrates in cactophilic Drosophila mojavensis. IX. Host plant and population specific epicuticular hydrocarbon expression influences mate choice and sexual selection
Authors: Havens J. A. , Etges W. J.
Published: January 2013

Sexual signals in cactophilic Drosophila mojavensis include cuticular hydrocarbons (CHCs), contact pheromones that mediate female discrimination of males during courtship. CHCs, along with male courtship songs, cause premating isolation between diverged populations, and are influenced by genotype × environment interactions caused by different host cacti. CHC profiles of mated and unmated adult flies from a Baja California and a mainland Mexico population of D. mojavensis reared on two host cacti were assayed to test the hypothesis that male CHCs mediate within‐population female discrimination of males. In multiple choice courtship trials, mated and unmated males differed in CHC profiles, indicating that females prefer males with particular blends of CHCs. Mated and unmated females significantly differed in CHC profiles as well. Adults in the choice trials had CHC profiles that were significantly different from those in pair‐mated adults from no‐choice trials revealing an influence of sexual selection. Females preferred different male CHC blends in each population, but the influence of host cactus on CHC variation was significant only in the mainland population indicating population‐specific plasticity in CHCs. Different groups of CHCs mediated female choice‐based sexual selection in each population suggesting that geographical and ecological divergence has the potential to promote divergence in mate communication systems.
The octadecaneuropeptide ODN prevents 6‐hydroxydopamine‐induced apoptosis of cerebellar granule neurons through a PKC‐MAPK‐dependent pathway
Authors: Kaddour Hadhemi , Hamdi Yosra , Vaudry David , Basille Magalie , Desrues Laurence , Leprince Jérôme , Castel Hélène , Vaudry Hubert , Tonon Marie‐Christine , Amri Mohamed , Masmoudi‐Kouki Olfa
Published: January 2013

Oxidative stress, induced by various neurodegenerative diseases, initiates a cascade of events leading to apoptosis, and thus plays a critical role in neuronal injury. In this study, we have investigated the potential neuroprotective effect of the octadecaneuropeptide (ODN) on 6‐hydroxydopamine (6‐OHDA)‐induced oxidative stress and apoptosis in cerebellar granule neurons (CGN). ODN, which is produced by astrocytes, is an endogenous ligand for both central‐type benzodiazepine receptors (CBR) and a metabotropic receptor. Incubation of neurons with subnanomolar concentrations of ODN (10−18 to 10−12 M) inhibited 6‐OHDA‐evoked cell death in a concentration‐dependent manner. The effect of ODN on neuronal survival was abrogated by the metabotropic receptor antagonist, cyclo1–8[DLeu5]OP, but not by a CBR antagonist. ODN stimulated polyphosphoinositide turnover and ERK phosphorylation in CGN. The protective effect of ODN against 6‐OHDA toxicity involved the phospholipase C/ERK MAPK transduction cascade. 6‐OHDA treatment induced an accumulation of reactive oxygen species, an increase of the expression of the pro‐apoptotic gene Bax, a drop of the mitochondrial membrane potential and a stimulation of caspase‐3 activity. Exposure of 6‐OHDA‐treated cells to ODN blocked all the deleterious effects of the toxin. Taken together, these data demonstrate for the first time that ODN is a neuroprotective agent that prevents 6‐OHDA‐induced oxidative stress and apoptotic cell death.
Transporting newborns with transposition of the great arteries
Authors: Woods Patricia , Browning Carmo Kathryn , Wall Margaret , Berry Andrew
Published: January 2013

Aims

The aim of the study was to examine the prevalence and management of outborn babies with a post‐natally confirmed diagnosis of transposition of the great arteries (TGA) requiring transport by the Newborn and Paediatric Emergency Transport Service (NETS), New South Wales during the epoch 1991–2010.

Method

A retrospective audit of NETS database and case notes. The physiological status, interventions and any complications encountered from the point of referral to NETS (pre‐transport), stabilisation (transport) and subsequent admission to the receiving hospital (post‐transport) were evaluated.

Results

One hundred fifty‐seven infants with TGA were transported, with an average of eight per year (1:11 598 births). Seven (4%) had an antenatal diagnosis, and 72 (46%) had a post‐natal diagnosis prior to referral. Physiological and clinical parameters demonstrated overall clinical stability; however, 47% of the babies had a PaO2 <30 mmHg, and approximately one‐fifth had oxygen saturations <70%. Rates of mechanical ventilation and prostaglandin E1 administration were approximately 50%. A quarter of transported babies encountered a transport‐related event, including one death and two babies for which a decision was reached to forego life‐sustaining treatment at the referring hospital.

Conclusions

Most newborns with TGA remain stable or improve during transport. There is a rate of adverse events; however, this reinforces the need to facilitate delivery where there is ready access to interventional paediatric cardiology services.
Size‐symmetric competition in a shade‐tolerant invasive plant
Authors: PAN Xiao‐Yun , WEINER Jacob , LI Bo
Published: January 2013

Plant responses to crowding have been investigated extensively in stands of light‐demanding species, but shade‐tolerant species may react differently. In the present study, we investigated the effect of density on the mortality, size inequality, and biomass allocation of Alternanthera philoxeroides, a shade‐tolerant invasive species. Stem fragments of A. philoxeroides were grown at either low or high densities (6 vs. 24 plants per pot) under three light levels (10%, 34%, and 100% full sun). After 8 weeks, survival was 31% lower in pots with a higher initial density. Both high density and low light levels reduced plant size substantially. Mean plant biomass ranged from 0.23 g in high‐density and low‐light pots to 4.41 g in low‐density and high‐light pots. There were no strong or significant effects of density or light level on size inequality of survivors. Most of the variation in allocation and morphology in response to light level and crowding were due to plant size and allometric growth, with little evidence of true plasticity. There was a small but significant increase in shoot allocation, in the direction predicted by optimal allocation theory, at low light levels. Our results show that intense competition need not be size asymmetric, and suggest that tolerance to low light levels involves a reduction in phenotypic plasticity. Responses of the invasive A. philoxeroides to crowding may be an example of an invasive plant's success in establishing dense stands of closely related individuals that are shade tolerant, cooperative, and follow a relatively fixed allometric trajectory with low plasticity.
Management of HBV in immunocompromised patients
Authors: Pol Stanislas
Published: January 2013

Hepatitis B virus (HBV) infection is more frequent in immune deficient populations than in the general population with lower rates of spontaneous recovery in acute cases, thus explaining the high rate of chronic infection and the increased risk of cirrhosis and hepatocellular carcinoma, resulting in increased morbidity‐mortality in these patients. The negative impact of immune deficiency on chronic HBV infection is related to two non‐exclusive factors: (i) high viral load enhances the progression of fibrosis and may result in a rare severe liver disease called fibrosing cholestatic hepatitis, which reflects the direct toxicity of high levels of HBV proteins; (ii) The pathobiology of HBV infection is mainly immune‐mediated via HBV‐specific T lymphocytotoxicity. The reduction or discontinuation of immune deficiency may result in severe liver disease including fulminant hepatitis from immune restoration. Thus, immune deficiency enhances the hepatitis B viral load, which results in the progression of fibrosis and/or acute exacerbation of underlying liver disease (HBV reactivation) on one hand, whereas reduction in immune deficiency may also be harmful because of immune restoration on the other hand. This double‐edged sword explains why the diagnosis and evaluation of the impact of HBV infection on the liver must be especially rigorous in cases of immune deficiency whatever the cause: transplantation, oncology, haematology, internal medicine (rheumatology, gastroenterology …) or HIV infection, and why pre‐emptive therapy by HBV nucleos(t)ide analogues should be considered for all HBV‐infected patients.
Current management of delta hepatitis
Authors: Rizzetto Mario
Published: January 2013

Interferon is the only therapy for chronic hepatitis D. Nucleos(t)ides are not effective against the helper hepatitis B virus. The current therapeutic recommendation is a weekly dose of pegylated interferon (PEG‐IFN)‐α, for 12–18 months. Serum HDV‐RNA only becomes undetectable after 6 months of therapy in about a quarter of the patients. Hepatitis D virus (HDV) may relapse in patients if they remain HBsAg positive. Although the end‐point of therapy is the clearance of the HBsAg, this is seldom achieved. Current management of HDV patients is based on standard practices which should be pragmatic and individualized.
How to optimize HCV therapy in genotype 1 patients: management of side‐effects
Authors: Chopra Angeli , Klein Patricia L. , Drinnan Thia , Lee Samuel S.
Published: January 2013

Antiviral therapy for chronic hepatitis C has dramatically changed with the advent of triple therapy incorporating direct‐acting antivirals (DAAs) such as the protease inhibitors (PI) boceprevir and telaprevir. Such triple‐therapy is associated with a new spectrum of side‐effects which can hamper quality of life. These may lead to dosage reduction and sometimes discontinuation of therapy. This review presents practical tips to help manage adverse effects appropriately and efficiently. The main adverse effects causing discontinuation of therapy are varied. Although the most common adverse effects are the ‘flu’‐like symptoms of fatigue, myalgia, fever and lassitude, these are usually easily managed and do not lead to treatment discontinuation. Cytopaenia, particularly anaemia, has emerged as perhaps the most troublesome side‐effect. Cirrhotic patients are especially prone to moderate or severe anaemia with boceprevir and telaprevir triple‐therapy regimens. Aggressive ribavirin dosage reductions, erythropoietin and blood transfusions are effective for managing anaemia. Skin rash can be controlled with moisturization and corticosteroid ointment. Rarely, dermatology consultation is required for further management. Anal discomfort, with or without diarrhoea, sometimes responds to barrier creams and haemorrhoidal ointments. Dysgeusia is treated by sipping water frequently, oral ointments and mouth washes to maintain salivary flow and oral hygiene. Successful adherence to treatment can be enhanced by a strong support network for the patient, including specially‐trained hepatitis nurses and a multidisciplinary team incorporating pharmacists, counsellors and social workers.
Management of acute hepatitis B and reactivation of hepatitis B
Authors: Jindal Ankur , Kumar Manoj , Sarin Shiv K.
Published: January 2013

The natural course of hepatitis B virus infection and the resulting hepatic injury is determined by the degree of virus replication and the intensity of host immune response. Upon exposure to hepatitis B virus (HBV), individuals with a vigorous and broad immune response develop acute self‐limited infection, which may result in acute hepatitis. However, with stringent testing for HBV and universal precautions, acute HBV is rather rare. Reactivation of HBV most often presents as acute hepatitis B (AVH‐B) and clinically, it is difficult to differentiate AVH‐B from reactivation of chronic hepatitis B (CHB) and it requires a high index of suspicion. In the presence of high HBV DNA (>2 × 104 IU/ml) underlying liver disease should be investigated by liver biopsy, endoscopy and/or imaging. The degree of liver failure often depends on the severity of acute insult and the stage of underlying chronic liver disease. Mutations in the HBV genome, immunosuppressive therapy and viral or drug induced injury are common causes of reactivation. As most patients with AVH‐B resolve the infection spontaneously, antiviral therapy is not indicated in them. However, the use of a potent oral nucleoside(tide) analogue is necessary as soon as possible in patients with CHB reactivation. Liver transplantation should be considered in patients who develop liver failure secondary to severe acute exacerbation. If this is not feasible, supportive therapy with the addition of granulocyte colony stimulating factor (GCSF) therapy could be beneficial.
Hepatocellular carcinoma treated with sorafenib: early detection of treatment response and major adverse events by contrast‐enhanced US
Authors: Sugimoto Katsutoshi , Moriyasu Fuminori , Saito Kazuhiro , Rognin Nicolas , Kamiyama Naohisa , Furuichi Yoshihiro , Imai Yasuharu
Published: January 2013

Background & Aims

Early prediction of tumour response and major adverse events (AEs), especially liver failure, in patients with hepatocellular carcinoma (HCC) is essential for maximizing the clinical benefits of sorafenib. To evaluate the usefulness of dynamic contrast‐enhanced ultrasound (DCE‐US) for the early prediction of tumour response and major AEs in HCC patients.

Methods

Thirty‐seven HCC patients were started on a reduced dosage of sorafenib, subsequently increased to the standard dosage. Tumour response at 1 month was assessed by CT using the Response Evaluation Criteria in Solid Tumors (RECIST). Major AEs were defined as grade 3 or higher. DCE‐US was performed before treatment (day 0) and on days 7, 14 and 28. Changes in perfusion parameters in the tumour and liver parenchyma between day 0 and later time points were compared between treatment responders and nonresponders based on RECIST and between patients who experienced major AEs and those who did not. Tumour results were also compared with progression‐free survival (PFS) and overall survival (OS).

Results

Tumour perfusion parameters based on the area under the time‐intensity curve (AUC) were statistically significant, with AUC during washin on day 14, the most relevant for tumour response (P = 0.0016) and AUC during washin on day 7, the most relevant for both PFS (P = 0.009) and OS (P = 0.037). A decrease in total AUC between days 0 and 7 in the liver parenchyma was strongly correlated with major AEs (P = 0.0002).

Conclusion

DCE‐US may be useful for the early prediction of tumour response and major AEs in patients with HCC.
‘Big data’ from shrinking pathogen populations
Authors: Neafsey Daniel E.
Published: January 2013

Falling costs for genome sequencing and genotyping mean that population genomic data sets are becoming commonplace for a wide variety of species. Once these data are used for the initial tasks of investigating population structure and demographic history, however, is there reason to go back for more? In this issue of Molecular Ecology, Nkhoma et al. (2013) explore the applications of longitudinal genomic diversity data for detecting changes in the prevalence and transmission of the Plasmodium falciparum malaria parasite in South‐East Asia. While this study finds several genetic signatures indicative of reduced disease transmission, other measures, such as short‐term effective population size, geographical population structure and heterozygosity, were not informative. These results indicate the potential contribution of genomic data to the surveillance of small, dynamic populations, whether they are at risk of extinction or targeted for elimination. The interpretation of such data will require close consideration of biological context, however, at both the species and the population level.
Effects of oral administration of rotenone on gastrointestinal functions in mice
Authors: Tasselli M. , Chaumette T. , Paillusson S. , Monnet Y. , Lafoux A. , Huchet‐Cadiou C. , Aubert P. , Hunot S. , Derkinderen P. , Neunlist M.
Published: January 2013

Background  The systemic rotenone model of Parkinson’s disease (PD) accurately replicates many aspects of the pathology of human PD, especially neurodegeneration of the substantia nigra and lesions in the enteric nervous system (ENS). Nevertheless, the precise effects of oral rotenone on the ENS have not been addressed yet. This study was therefore designed to assess the effects of a chronic oral treatment by rotenone on enteric neurochemical phenotype, gastrointestinal (GI) motility, and intestinal epithelial barrier permeability.

Methods  Male C57BL6N mice received once daily oral rotenone administration for 28 days. GI functions were analyzed 4 weeks after rotenone treatment. Gastrointestinal motility was assessed by measuring gastric emptying, total transit time, fecal pellet output, and bead latency. Intestinal barrier permeability was evaluated both in vivo and ex vivo. The number of enteric neurons and the enteric neurochemical phenotype were analyzed by immunohistochemistry. Tyrosine hydroxylase (TH) immunostaining of dopaminergic neurons of the substantia nigra was performed in a subset of animals.

Key Results  Mice treated orally with rotenone had a decrease in fecal pellet output and in jejunal alpha‐synuclein expression as compared with control animals. This was associated with a significant decrease in TH‐immunoreactive neurons in the substantia nigra. No change in gastric emptying, total transit time, intestinal epithelial barrier permeability, and enteric neurochemical phenotype was observed.

Conclusions & Inferences  Chronic oral treatment with rotenone only induced minor changes in the ENS and did not recapitulate the GI abnormalities seen in PD, while it replicates neurodegeneration of the substantia nigra.
Pediatric kidney transplant practice patterns and outcome benchmarks, 1987–2010: A report of the North American Pediatric Renal Trials and Collaborative Studies
Authors: Smith Jodi M. , Martz Karen , Blydt‐Hansen Tom D.
Published: January 2013

The NAPRTCS transplant registry has collected clinical information on children undergoing kidney transplantation since 1987 and now includes information on 11 603 kidney transplants in 10 632 patients. Since the first data analysis in 1989, NAPRTCS reports have documented marked improvements in outcome after kidney transplantation in addition to identifying factors associated with both favorable and poor outcomes. Patient demographics have changed over the course of the registry with a decrease in the percentage of white recipients from a high of 72% in 1987 to less than 43% in 2007. The percentage of living donors decreased to its lowest point in 2007 at 37%. Acute rejection rates continue to decline with improvements in short‐ and long‐term graft survival. Recently, NAPRTCS data have been used as a source of benchmark data for pediatric kidney transplant centers.
Protein extract of ultraviolet‐irradiated human skin keratinocytes promote the expression of mitogen‐activated protein kinases, nuclear factor‐κB and interferon regulatory factor‐3 in Langerhans cells via Toll‐like receptor 2 and 4
Authors: Wang Xiao‐Yong , Tao Cheng‐Jun , Wu Qiao‐Yun , Yuan Cheng‐Da
Published: January 2013

Aim

In this study, we investigated whether the protein extract of ultraviolet‐irradiated human skin keratinocytes can activate Toll‐like receptor 2 and Toll‐like receptor 4 of Langerhans cells and induce the downstream gene expression of mitogen‐activated protein kinases, nuclear factor‐κB and interferon regulatory factor‐3.

Methods

The protein expression of mitogen‐activated protein kinases, nuclear factor‐κB and interferon regulatory factor‐3 in Langerhans cells and the protein expression of HSP60, HSP70 and β‐defensin 2 in keratinocytes were examined using Western blot analysis. Langerhans cells were pretreated with or without Toll‐like receptor 2 and Toll‐like receptor 4 siRNA.

Results

We found that the protein extract of ultraviolet‐irradiated keratinocytes upregulated the expression of mitogen‐activated protein kinases, nuclear factor‐κB and interferon regulatory factor‐3 in Langerhans cells via Toll‐like receptor 2 and Toll‐like receptor 4. We also found that ultraviolet radiation upregulated the expression HSP60, HSP70 and β‐defensin 2 in keratinocytes.

Conclusions

Our previous study demonstrated that ultraviolet radiation upregulated Toll‐like receptor 2 and Toll‐like receptor 4 expression in Langerhans cells. Ultraviolet radiation also upregulated mitogen‐activated protein kinases and nuclear factor‐κB/p65 expression via Toll‐like receptor 2 and Toll‐like receptor 4, and upregulated interferon regulatory factor‐3 expression partially via Toll‐like receptor 4. So we conclude that ultraviolet radiation can directly or indirectly activate keratinocytes to induce endogenous ligands which stimulate Toll‐like receptor 2‐ or Toll‐like receptor 4‐dependent signaling cascade in Langerhans cells, sequentially influence innate and adaptive immune responses.
Evaluation of apoptosis regulatory proteins in response to PUVA therapy for psoriasis
Authors: El‐Domyati Moetaz , Moftah Noha H. , Nasif Ghada A. , Abdel‐Wahab Hossam M. , Barakat Manal T. , Abdel‐Aziz Rasha T.
Published: January 2013

Background

The histopathologic changes characteristic of psoriasis might be related to suppressed apoptosis. One of the actions of psoralen ultraviolet A (PUVA) in psoriasis could be exerted through induction of apoptosis of keratinocytes and lymphocytes; however, its exact molecular mechanism is still confusing.

Aim

In this study, we evaluated the expression of pro‐apoptotic (P53, Fas and Bax) and anti‐apoptotic (Bcl‐2) proteins correlating it with apoptotic index (AI) and epidermal thickness in psoriatic skin before and after PUVA therapy.

Methods

Lesional and non‐lesional skin biopsy specimens were obtained from 10 patients with generalized plaque psoriasis before and after 8 weeks of PUVA therapy. Histometric measurements of epidermal thickness as well as P53, Fas, Bax and Bcl‐2 expressions were evaluated using immunoperoxidase technique and apoptotic cells were detected by terminal deoxynucleotide transferase (TdT) mediated deoxyuridine triphosphate nick end labeling (TUNEL) method.

Results

After PUVA therapy, the epidermal thickness of psoriatic skin was significantly decreased (P < 0.001) and keratinocytes of psoriatic skin showed significant increased expression of P53 (P < 0.001), Fas (P < 0.001) and Bcl‐2 (P < 0.001) with no significant change in Bax expression (P > 0.05). Apart from significant decrease of Bcl‐2 expression (P = 0.01), no significant difference in all previous markers were encountered in lymphocytes (P53, Fas and Bax; P > 0.05) after PUVA therapy. The AI was significantly increased (P = 0.008) after PUVA therapy especially in lymphocytes (P = 0.002).

Conclusion

The present study suggests that one of the actions of PUVA therapy in psoriasis might be exerted through induction of apoptosis especially of lymphocytes by suppression of Bcl‐2 expression and of keratinocytes through P53 and Fas pathways leading to healing of psoriasis.
Severance Payment: Incentive or Lethargy Effect?
Authors: Gabuthy Yannick , Lambert Eve‐Angéline , Thomas Lionel
Published: January 2013

The aim of the paper is to determine the impact of severance payment on the motivation of the worker to make an effort, when there is a risk for him to be dismissed once his effort was made. We highlight through a two‐stage model the various factors which influence the dismissal decision by the firm and the worker's effort, such as the initial wage, the litigation costs and the relative bargaining powers of the parties when the relationship ends or goes on. In this context, we show that the impact of the severance payment paid ex post in case of dismissal on the level of effort chosen by the worker ex ante may depend on such characteristics.
Assigning Integration: A Framework for Intellectual, Personal, and Professional Development in Seminary Courses
Authors: Kanarek Jane , Lehman Marjorie
Published: January 2013

This article explores assignments as a core teaching practice essential to integrating the cognitive, personal, and professional identities of seminary students. These core practices emerge in seminary curricula where there is a strong focus on the teaching of canonical texts and a goal of achieving textual mastery. We propose that carefully chosen and constructive assignments achieve the kind of integration necessary for building content knowledge and the professional, spiritual, and religious identities of our students. While the difference between the educational goals of clergy‐training in a seminary and training graduate students in the academy can be sharp, we argue here for ways to make that contrast both productive and generative.
Using Bible Commentaries in the Classroom
Authors: Phillips Gary , Patte Daniel , Kittredge Cynthia , Yang Seung Ai , Ngwa Kenneth
Published: January 2013

This discussion of the goals and methods of teaching biblical literature is an edited transcription of a panel recorded at the 2010 Society for Biblical Literature conference. The panelists were asked to reflect on William Placher's recently published theological commentary on Mark as an example or test case of how one might use a biblical commentary as a classroom resource. Karl Barth wrote that insofar as their usefulness to pastors goes, most modern commentaries are “no commentary at all, but merely the first step toward a commentary.” What value might commentaries have for our students, whether future pastors or undergraduates in the liberal arts? While the panel consisted of teachers of undergraduates as well as theological students, the emphasis of the presentations and subsequent discussion focused mostly on theological formation.
Actinomyces endogenous endophthalmitis in a cat following multiple dental extractions
Authors: Westermeyer Hans D. , Ward Daniel A. , Whittemore Jacqueline C. , Lyons Jeremiah A.
Published: January 2013

An 8‐year‐old, brachycephalic, mixed breed cat underwent full mouth tooth extractions for the treatment of tooth root abscessation. Subsequently, the cat developed anterior uveitis refractory to topical therapy that eventually necessitated enucleation. Actinomyces species were isolated from both the tooth root abscesses and the anterior chamber after enucleation. Histopathology of the enucleated eye revealed panophthalmitis with abundant intralesional bacteria morphologically consistent with Actinomyces. Between the time of tooth root extraction and enucleation (20 weeks), the cat was diagnosed with hyperthyroidism and treated with oral steroids for inflammatory bowel syndrome. We believe this report represents a rare case of endogenous endophthalmitis secondary to dental disease, possibly precipitated by concurrent immunosuppression.
Kajian Awal Terhadap Kesesuaian Plastik Abs Dalam Penghasilan Radas Makmal Yang Berbentuk Unik Dan Rumit Melalui Proses Pencontoh Sulungan Pantas
Authors: Mohamad Ibrahim M. N. , Abdul Ghani M. , Abdullah J.
Published: January 2013

Kajian ini dijalankan untuk mengkaji kesesuaian penghasilan radas makmal yang berbentuk unik lagi rumit melalui proses Pencontoh Sulungan Pantas (PSP) dengan menggunakan Model Pengendapan Terlakur (MPT). Dalam teknologi ini, bahan termoplastik seperti plastik ABS, ABSi, elastomer, polikarbonat, poliester atau polifenilsulfon digunakan sebagai bahan mentah utamanya untuk penghasilan objek tiga-dimensi tanpa menggunakan acuan. Penyelidikan ini dijalankan untuk mendapatkan maklumat awal terhadap sifat-sifat fizik produk ABS yang dihasilkan dengan kaedah MPT. Antara ujian yang dijalankan ialah analisia Termogravimetri (TGA) dan Kalorimeter Pengimbasan Perbezaan (DSC), kadar resapan terhadap air dan juga analisis penembusan. Dari analisis TGA didapati, sampel ABS hanya mengalami satu tahap penguraian iaitu pada suhu antara 240-500Â°C. Manakala suhu peralihan kaca bagi sampel tersebut yang diperoleh dari analisis DSC ialah 102.5Â°C. Sampel ABS juga didapati menyerap air sebanyak lima peratus setelah direndam pada suhu bilik selama 10 jam. Manakala ujian penembusan menunjukkan bahawa sampel ABS mesti mempunyai ketebalan yang agak tinggi (lebih daripada 4 mm) agar ia dapat menampung larutan atau cecair. Melalui keputusan daripada ujian-ujian ini, beberapa kelemahan plastik ABS dikenalpasti di samping beberapa cadangan untuk mengatasi kelemahan-kelemahan ini dibentangkan.

Kata kunci: Plastik ABS; Pencontoh Sulungan Pantas; radas makmal; bentuk unik

This research is carried out in order to find out the suitability of producing apparatus having unique shape and complex geometry through Rapid Prototyping (RP) process using Fused Deposition Modeling (FDM). In this technology, thermoplastics materials such as ABS, ABSi, elastomer, polycarbonate, polyester or polyfenilsulfone is used as a main raw material in producing three-dimensional object without molding. This study was performed in order to obtain prelimenary information of the physical properties of ABS product that was undergone FDM process. Several tests included Thermogravimetric Analyzer (TGA) and Differential Scanning Calorimetry (DSC), water absorbtion rate and penetration test were performed. From TGA result, the ABS sample undergone only one level of degredation which was at the range of 240-500Â°C. Whereas the glass transformation stage obtained from DSC result was 102.5Â°C. The ABS sample can absorb five percent of water when it was immersed at room temperature for 10 hours. While in penetration experiment, the ABS sample must have relatively high thickness (more than 4 mm) so that it can properly contained the solution or liquid. Several weaknesses of ABS plastic were identified from this preliminary study and suggestions to overcome these weaknesses were also presented.

Key words: ABS plastic; Rapid Prototyping; laboratory apparatus; unique shape
Kemalangan Jalan Raya: Analisis Data Membabitkan Pengguna Motosikal
Authors: Jaafar Talib Ria , Mustafa Mohd. Faizar , Kemin Sutiman , Kasiran Ramlan
Published: January 2013

Analisis data kecelakaan jalan raya dijalankan adalah untuk tempoh empat belas tahun bermula dari tahun 1985 hingga tahun 1998 yang diperolehi dari Laporan Perangkaan Kecelakaan Jalan Raya. Bilangan kemalangan bagi setiap 1,000,000 km motosikal berdaftar meningkat dari 0.45 pada tahun 1990 kepada 0.82 pada tahun 1998 dengan peningkatan sebanyak 82.2%. Walau bagaimanapun, bilangan kematian bagi setiap 1,000 motosikal terbabit dengan kemalangan menurun dari 56.9 pada tahun 1990 kepada 41.2 pada tahun 1998. Data di atas menunjukkan langkah yang diambil untuk mengurangkan kematian pengguna motosikal telah mencapai matlamatnya, tetapi langkah-langkah yang diambil untuk mengurangkan bilangan kemalangan perlu dikaji semula. Analisis data dari Laporan Perangkaan Kecelakaan Jalan Raya menunjukkan punca kemalangan adalah disebabkan oleh faktor manusia berdasarkan kepada fakta lebih 59% kemalangan berlaku di jalan lurus, lebih 59% berlaku di kawasan luar bandar dan lebih 62% yang terbabit adalah berumur di antara 10â€“30 tahun. Ini menunjukkan kebanyakan kemalangan berlaku adalah disebabkan oleh kecuaian, ketidakmahiran dan tidak berhemah semasa mengendali motosikal. Adalah dijangkakan kaedah cara penguatkuasaan dan pendidikan mengenai keselamatan jalan raya di peringkat sekolah rendah dapat mengurangkan kemalangan jalan raya. Analisis data juga menunjukkan pengguna motosikal mempunyai kebarangkalian yang paling rendah untuk mengalami kemalangan bagi setiap 1,000,000 km kenderaan berdaftar berdaftar jika dibandingkan dengan pengguna kenderaan yang lain.

Kata kunci: kemalangan jalan raya; motosikal; topi keledar; penguatkuasaan

Data on road crash were analyzed for a period of 14 years starting from 1985 to 1998 which was gathered from Statistical Report Road Crash. The number of accident for every 1,000,000,000 km registered motorcycle increased from 0.45 in year 1990 to 0.82 to in year 1998 with an increase of 82.2%. However, the number of death for every 1,000 motorcycle involved in accident reduced form 56.9 in year 1990 to 41.2 in year 1998. This data showed that the move taken to reduce the death of motorcycle user had achieved the target, but the moves taken to reduce the number accident need to be revised. Data analysis from Statistical Report Road Crash showed that the causes of accident were due to human factor based on the fact that more than 59% accident occurred on straight road, more than 59% occurred at rural areas and 67.2% involved in accident was between 11â€“30 years of age. This fact showed that most of accidents were occurred due to careless, not familiar, and not disciplines while maneuvering the motorcycle. It was taught that enforcement and education on road safety at primary school could reduce the road crash. This data analysis also showed that the motorcycle user was having a lower probability to involve in accident for every 1,000,000 km registered vehicles compared with other vehicle users.

Key words: road accident; motocycle; helmet; enforcement
Measurement of 3–D Shape of Multi–Surface Object in a Homogeneoues Background Using Phase–Shift Fringe Projection
Authors: Ratnam Mani Maran
Published: January 2013

Kertas kerja ini membentangkan keputusan mengaplikasi kaedah unjuran pinggir anjakan fasa untuk mengukur bentuk 3–D bagi objek berbilang muka di dalam latarbelakang berhomogen. Pinggir–pinggir anjakan fasa dianalisis untuk mendapatkan peta fasa bagi bentuk objek tersebut. Suatu kaedah untuk mengesan pinggir–pinggir bagi objek di dalam latar belakang berhomogen yang dibangunkan dalam kerja dahulu digunakan untuk mengesan sempadan objek. Algoritma yang digunakan untuk menyari data 3–D daripada peta fasa dibangunkan dengan menggunakan imej–imej simulasi dan kemudian dilaksanakan ke atas imej sebenar. Bandingan keputusan pengukuran dengan tinggi sebenar menunjukkan ralat maksimum sebanyak 0.3 mm.

Kata kunci: Unjuran pinggir; pengukuran 3-D; pelbagai muka

This paper presents the results of application of the phase–shift fringe projection method to the measurement of 3–D shape of a multi–surface object in a homogeneous background. The phase–shift fringes were analyzed to obtain a phase map of the object shape. An effective technique of detecting edges of the object in the homogeneous background developed in previous work was used to detect the object edges. The algorithm used to extract the 3–D data from the phase–map was developed using simulated images and later applied to a real image. Comparison of measurement results with the actual height of the object along two sections considered showed a maximum error of 0.3 mm.

Key words: Fringe projection; 3-D measurement; multi-surface
Harmonic Analysis of a Five Level Cascaded Inverter Under a New Modulation Scheme
Authors: Aziz J. , Salam Z.
Published: January 2013

Kertas kerja ini mengusulkan satu kaedah analitikal untuk meramalkan magnitud dan kedudukan harmonik voltan keluaran penyongsang lima tahap. Penyongsang tersebut telah digunakan untuk melaksanakan satu skim pemodulatan baru yang menggunakan beberapa isyarat memodulat berserta isyarat pembawa tunggal. Seterusnya daripada skim pemodulatan tersebut, persamaan matematik yang dapat menentukan pensuisan PWM diterbitkan. Untuk memastikan kelebihan skim pemodulatan tersebut, analisis harmonik untuk mendapatkan pekali Fourier diterbitkan dan dikira menggunakan MATLAB. Harmonik voltan keluaran yang diukur dan dikira seterusnya dibandingkan dan dibincangkan.

Kata kunci: Analisis harmonik; penyongsang bertahap

This paper proposes an analytical method to predict the incidence and magnitude of harmonics of the output voltage of a five–level cascaded inverter. The cascaded inverter is subjected to a new modulation scheme, which uses multiple modulating signals with a single carrier. From the modulation scheme, mathematical equations that define the PWM switching instants are derived. In order to justify the merits of the proposed modulation scheme, harmonic analysis for the Fourier coefficients is outlined and calculated using MATLAB. An experimental five–level cascaded inverter test–rig is built and the new modulation scheme is implemented. The calculated and measured harmonics of the output voltage are compared and discussed.

Key words: Harmonic analysis; cascaded inverter
ONO and Tunnel Oxide Characterization and Optimization for High Speed EEPROM Device
Authors: Hashim Uda , Mat Ayub Ramzan
Published: January 2013

Non-volatile memory processes, in particular the EEPROM process, is one of the hardest processes to be developed and the performance of the NVM products is normally judged from the programming speed and the density of the memory. The programming speed of the EEPROM cell depends critically on Tunnel Oxide Thickness (Xtun), Programming Voltage (Vp), ONO Thickness (Xpp) and Poly to Poly overlap Area (App). However, in this experiment only ONO and tunnel oxide layer are optimized and characterized. Three experiments were setup to improve the programming speed. The first experiment was to scale down the ONO layer thickness and followed by measurement of the threshold voltage and breakdown voltage of the new ONO thickness. The second and third experiments were setup to check the integrity of ONO and tunnel oxide layers respectively. The EEPROM cell was fabricated to observe the cross sectional of ONO and tunnel oxide layer. The characterization work on ONO and tunnel oxide layer to increase the programming speed of the memory cells of a 16k EEPROM device has been carried out. After scaling down the nitride of ONO layer from 160_ to 130_, the Vt program windows are further improved from 4.3V to 4.5V and from 0.7V to 0.9V for program high and program low operations, respectively. In this experiment, 130_ was found to be the best thickness for nitride of ONO layer. The breakdown voltage for ONO at 130_ of nitride thickness is 16.3V. The experiment revealed that the yields of ONO and tunnel oxide layer of the actual size on silicon were achieved at 98.7% and 99.92%, respectively.

Key words: ONO; tunnel oxide; EEPROM; threshold voltage; programming speed; polysilicon; control gate; floating gate; select gate
The Growth of Mixing Zone in Heterogeneous Porous Media
Authors: Othman M. R. , Badlishah Ahmad R. , May Z.
Published: January 2013

Dengan menggunakan penyelesaian analitikal yang merangkumi fraktal eksponen, pembesaran jarak pencampuran telah dapat ditentukan bagi model satu dimensi. Size zon pencampuran didapati meningkat apabila media berliang menjadi semakin heterogen. Dalam media berliang yang heterogen, saiz zon pencampuran meningkat apabila pemalar penyerakan meningkat terutama sekali pada aliran jangkamasa singkat relatif. Terdapat tiga faktor penting mempengaruhi saiz zon pencampuran penyerakan, ΔxD. Perkara terpenting dalam kajian ini ialah keheterogenan takungan, yang dipersembahkan oleh fraktal eksponen, β. Hasil kajian mendapati bahawa apabila β menjadi kecil (media berliang menjadi semakin heterogen), saiz zon pencampuran meningkat. Satu lagi faktor mempengaruhi ΔxD ialah pemalar penyerakan bersandar masa, Κ(tD). Di dalam takungan heterogen, zon pencampuran meningkat dengan peningkatan nilai pemalar penyerakan pada aliran jangkamasa singkat relatif. Bagi aliran jangkamasa panjang relatif, bagaimanapun, ΔxD terus meningkat walaupun Κ(tD) menjadi tetap. Faktor ketiga ialah purata kelajuan bendalir, ν. Zon pencampuran mempunyai perkaitan songsang dengan kelajuan bendalir dengan cara ΔxD meningkat apabila ν berkurangan.

Kata kunci: Kehomogenan; keheterogenan; pekali penyerakan; eksponen fraktal; zon pencampuran; media berliang

Utilizing currently available analytical solutions that incorporate fractal exponent, the growth of mixing length of injected solvent was determined for a one-dimensional model. Mixing zone size was found to increase as porous medium becomes increasingly heterogeneous. In a heterogeneous porous media, mixing zone size increases as dispersion coefficient increases particularly at relatively short duration of flow. There are three important factors influencing the size of the dispersive mixing zone, ΔxD. Of particular importance in this study is reservoir heterogeneity, which is represented by a fractal exponent, β. It was discovered that as β becomes smaller (porous medium becomes increasingly heterogeneous), the size of the mixing zone increases. Another factor affecting ΔxD is time dependent dispersion coefficient, Κ(tD). In a heterogeneous reservoir, mixing zone increases with increasing value of dispersion coefficient at relatively short duration of flow. For relatively long period of flow, however? ΔxD continues to increase even though Κ(tD) remains constant. The third factor is average fluid velocity, ν. Mixing zones have inverse relationship with fluid velocity in that ΔxD increases as ν decreases.

Key words: Homogeneity; heterogeneity; dispersion coefficient; fractal exponent; mixing zone; dimensionless concentration; porous media
Melamine–Urea–Formaldehyde (MUF) Resin: The Effect of the Number of Reaction Stages and Mole Ratio on Resin Properties
Authors: Bono Awang , Yeo Kiam Beng , Siambun Nancy Julius
Published: January 2013

Resin MUF yang boleh larut dalam air digunakan dengan meluas sebagai bahan pelekat dalam industri kayu, teknologi salutan, industri kertas dan merupakan bahan utama dalam penghasilan barangan dapur plastik. Sifat resin yang berbeza diperlukan dalam aplikasi yang berlainan. Sifat–sifat resin ini dipengaruhi oleh beberapa faktor iaitu nisbah mol antara formaldehid dengan melamina/urea pada setiap peringkat tindak balas dan bilangan peringkat tindak balas di mana sebatian amino ditindak balaskan. Sifat–sifat resin yang penting ialah kestabilan resin, kelarutan dalam air yang tinggi dan tempoh pengerasan yang pendek. Kajian lepas telah menghasilkan resin MUF dengan sifat–sifat ini, walau bagaimanapun ia tidak mempunyai kandungan melamina dan urea yang mencukupi, untuk menyeimbangi kos dan prestasi. Selain itu haba juga diperlukan untuk membantu memendekkan tempoh pengerasan resin. Dalam kajian ini, kesan perubahan formula ke atas sifat–sifat resin seperti kestabilan resin, kelarutan dalam dan tempoh pengerasan pada suhu bilik dikaji. Keputusan menunjukkan bahawa kestabilan resin meningkat apabila bilangan peringkat tindak balas dan kandungan melamina meningkat. Walau bagaimanapun tempoh pengerasan turut dipanjangkan. Formula ini mempunyai kandungan melamina dan urea yang mencukupi, di mana ia berkos rendah berbanding resin melamina-formaldehid (MF), tapi dengan prestasi yang baik.

Kata kunci: Melamina-urea-formaldehid (MUF); urea; melamina; formaldehid

MUF resin is widely used as an adhesive in wood industries, coating technology, paper industries and a main material in kitchenware production. In different application, various MUF resin properties are required. The MUF resin properties are affected by several factors, for example mole ratio of formaldehyde to melamine/urea at each reaction stage and number of reaction stages where the amino compounds are reacted. Previous researches have developed MUF resin with these properties, however the formulation lack sufficient amount of melamine or urea to balance the cost and performance. Furthermore, shorter curing period could only be obtained with the help of external heat. In this research, effects of formula variation on resin properties such as resin storage stability, solubility in water and curing period at room temperature are investigated. The results showed that in 3-reaction stage of MUF resin process, the ratio of formaldehyde to urea/melamine in each reaction stage has caused significant increases in MUF resin curing period, solubility in water and resin storage stability. These formulations contains sufficient amount of melamine and urea, which lowered the cost and yet maintaining good performance as compared to melamine–formaldehyde (MF) resin.

Key words: Melamine-urea-formaldehyde (MUF); urea; melamine; formaldehyde
Simbolisme Sains Dalam Wahyu Keserasian Antara Ayat Maqru´ah dengan Ayat Manzurah
Authors: Awang Ramli
Published: January 2013

Makro kosmos atau alam semesta merupakan Kitab Allah [wahyu Allah] yang bersifat kawni. Dalam lain perkataan ia dikenali sebagai ayat-ayat al-kawniyah [ayatullah al-kawniyyah]. Mikro kosmos pula ialah ayat-ayat Allah yang bersifat qur’ani [yang dibaca] dan ia merupakan pasangan kepada makro kosmos. Ayat-ayat yang bersifat qur’ani adalah sebagai panduan untuk manusia meneroka ayat-ayat al-kawniyyah. Kedua-dua ayat ini sama sekali tiada pertentangan bahkan saling membenarkan dan berkaitan. Ayat-ayat quran ditafsirkan oleh ayat quran yang lain, begitu juga dengan ayat al-kawni, ia juga saling ditafsirkan oleh ayat kawni yang lain. Selain daripada itu ayat kawni juga menjadi pentafsir kepada ayat qur’ani. Tegasnya kedua-dua ayat Allah tersebut saling mentafsirkan antara sesamanya. Kedua-duanya ada sifat simbolis yang unik lagi tersendiri; masing-masing saling memperkukuhkan antara sesamanya dalam ruang dan peranan yang berbeza. Kertas ini bertujuan mendedahkan keserasian ciptaan Allah yang terdapat pada ayat-ayatNya dalam rangla memperlihatkan sifat keesaan dan keagunganNya supaya hamba-hambaNya benar-benar mengabdikan diri kepadaNya; serta meninjau khitab Quran yang ditujukan kepada mereka yang berakal untuk memahami kaitan ayat manzurah dan maqru’ah secara simbolis.
Cure Characteristics and Mechanical Properties of Natural Rubber/Organoclay Nanocomposites
Authors: Teh P. L. , Mohd Ishak Z. A. , Ishiaku U. S. , Kargerâ€“Kocsis J.
Published: January 2013

Pengisi organoclay telah ditambahkan ke dalam getah asli dan dimatangkan dengan menggunakan sistem pemvulkanan konvensional. Kandungan pengisi yang ditambah adalah antara 0â€“10 phr. Penyebatian telah dicirikan mengikuti sifat pematangan dan sifat mekanikal. Sifat pematangan iaitu masa pematangan dan tork penyebatian getah telah dijalankan dengan menggunakan reometer Monsanto MDR 2000. Sifat mekanikal telah dikaji. Kekuatan tegangan, pemutusan pada takat putus dan sifat cabikan telah mencapai kemajuan pada takat 2 phr organoclay. Penambahan dalam kandungan organoclay yang seterusnya telah mengurangkan sifatâ€“sifat tersebut. Modulus pada 100% pemanjangan (M100) dan modulus pada 300% pemanjangan (M300) telah bertambah secara berterusan dengan kandungan pengisi dari 0â€“10 phr. Mikroskopi Imbasan Elektron telah digunakan untuk mengkaji mikrostruktur pada permukaan sampel.

Kata kunci: Komposit nano; organoclay; getah asli; sifat pematangan dan sifat mekanikal

Organoclay filler was added to natural rubber and cured by conventional vulcanization system. The filler loading was varied from 0â€“10 phr. The compounds were characterized in respect of their curing characteristics and mechanical properties. The cure characteristics: cure time and torque of the rubber compounds were studied by using the Monsanto MDR 2000 rheometer. The mechanical properties were investigated. The tensile strength, elongation at break and tear properties were improved at 2 phr organoclay. Further increase in organoclay loading decreases these properties. Modulus at 100% (M100) and modulus at 300% (M300) increased continuously with filler loading from 0â€“10 phr. Scanning electron microscopy was used to study the microstructure of the fracture surfaces.

Key words: Nanocomposites; organoclay; natural rubber; cure characteristics; mechanical properties