Assessment of Daytime and Nighttime Ground Level Ozone Pollution in Malaysian Urban Areas

@#Introduction: Ozone (O3 ) is a significant component of photochemical smog as a typical secondary which is formed via nitrogen oxide photochemical interactions with volatile organic compounds (VOCs). This research discerns the complex influence of meteorological parameters and air pollutants influencing O3 concentrations. Methods: Data were acquired from 1 January 2018 until 31 December 2020 that including ozone (O3 ), nitrogen oxide (NOx), nitric oxide (NO), sulphur dioxide (SO2 ), nitrogen dioxide (NO2 ), carbon monoxide (CO), particulate matter (PM10, PM2.5), wind speed, solar radiation, temperature, and relative humidity (RH). Data were analysed using descriptive statistics in terms of line graphs. Results: The results demonstrate that the O3 concentration peaked around 14:00 hours and dropped at night (20:00 hours) owing to the lack of sunshine and redox processes. Conclusion: In conclusion, ozone precursors played an important role in ozone formation and the findings of this research are valuable for policymakers and other interested parties

Cytotoxic Activity of Ethanolic Extract Aquilaria malaccensis Leaves Against MCF-7 Cells

@#Introduction: Aquilaria malaccensis, also known as “Pokok Karas” in Malaysia, is widely used in Southeast Asian countries for the treatment of joint pain, diarrhoea and inflammatory diseases, and has shown beneficial effects as an anticancer agent. The aim of this study was to investigate the effect of ethanol leaf extracts of A. malaccensis on MCF-7 cells. Methods: MTT-based cytotoxic and antiproliferative assay was used to determine the outcome of ethanolic extract toward MCF-7 cells. The mode of cell death was determined by the AO/PI double staining assay and the depolarisation of the mitochondria membrane potential. Results: IC50 value of the extract against MCF-7 cells treated for 72 hours was 4.1 ± 2.08 µg/mL, while the IC50 value for doxorubicin was 2.92 ± 0.12 µg/mL. The extract showed a lower cytotoxic effect against the NIH/3T3 cells and inhibited the growth of MCF-7 cells in a dose dependent manner. AO/PI double stain showed that the ethanolic extract of A. malaccensis leaves induced MCF-7 cells into apoptotic cell death. The present study showed that the ethanolic extract of A. malaccensis induced apoptosis through mitochondrial pathway as indicated by its ability to take up JC-1. Conclusion: The study found that ethanolic extract obtained from A. malaccensis leaves is cytotoxic on MCF-7 cells, resulting to apoptotic cell death of the cells.

Prevalence of Burnout and Its Associated Factors among Medical Students in a Public University in Selangor, Malaysia: a CrossSectional Study

@#Introduction: Burnout is a growing trend among medical students worldwide. The aim of this study was to determine the prevalence and factors associated with burnout among medical students at a public university in Malaysia. Methods: A cross-sectional study was conducted among 1st through 5th year medical students at a public university using a simple random sampling method in recruiting participants. In this study, The Maslach Burnout Inventory-General Survey for Student (MBI-SS) was used and burnout is defined as severely emotionally exhausted and severely depersonalised. Results: A total of 328 medical students were recruited with a with response rate of 88.6%. The burnout prevalence was 10.1%. Based on multivariate logistic regression, presence of smartphone addiction with adjusted (odds ratio (OR) 7.37, 95% confidence interval (CI) = 1.67, 32.49), course choice not based on personal interest or due to family pressure (OR 2.72, 95% CI = 1.08, 6.85) and the presence of family relationship problems (OR = 3.58, 95% CI = 1.27, 10.04) are more likely to be associated with burnout among the medical students. Conclusion: Our study has shown that every tenth medical students suffers from burnout. Medical students who are addicted to smartphone, have chosen medical course against individual interest or because of family pressure and have family relationship problems are at risk of getting burnout. Intervention is required to address this issue for the future well-being of medical students.

Exploring the Potential Use of Supplementary E-learning Tools for Integrated Anatomy-Radiology Teaching

@#The evolution of anatomy education yields a variety of instructional strategies to enhance students’ comprehension of gross anatomy. Apart from these multi-modality approaches, various studies suggest that anatomy instruction is more effective when it is taught with radiological integration during the early phase of the medical curriculum. Studies have shown that the introduction of basic radiological knowledge in anatomy learning enhances visuospatial skills, which are important for safe clinical practice. Nevertheless, considerable variation in the radiological anatomy teaching exists in terms of delivery methods, radiological materials, and teaching time. One way to address these limitations is by using integrated radiology anatomy e-learning platforms. Recent advancements in technology have given rise to immense attention to e-learning platforms, which have been considered to be an effective modality in optimising the student learning process. Hence, this article explores the potential use of e-learning tools, namely integrated with radiological imaging, in teaching gross anatomy.

Relationships between Antiretroviral Therapy Adherence with Personality Traits and Presence of Psychological Distress among Adults with Human Immunodeficiency Virus in Northwest Peninsular Malaysia: A Cross-Sectional Study

@#Introduction: Treatment adherence with antiretroviral therapy (ART) and its related factors have hitherto been the subject of clinical concern. However, research focusing on the relationships between ART adherence and the presence of psychological distress and selected personality traits have yet to be concluded. Therefore, our study aimed to remedy this. Methods: A multicentre hospital-based cross-sectional study was conducted in northwest Peninsular Malaysia on HIV outpatients given ART from July 1st, 2018, till April 31st, 2020. Participants were recruited via purposive sampling. Data were collected through an interviewer-guided questionnaires: Hospital Anxiety and Depression Scale (HADS) and Zuckerman-Kuhlman personality test (ZKPQ-M-40-CC), and interviewer-guided Timeline Follow-back (TLFB) for the assessment of adherence to ART. Results: A total of 229 patients completed the study. Majority (n=220, 96.1%) were considered adherent to ART. Among those who were non-adherent, two (22.2%) had anxiety disorder and five (55.6%) had depressive disorder. There was no significant association between treatment adherence and the presence of anxiety nor depression. However, sociodemographic factors determined that age group (p=0.033) and marital status (p=0.044) were significantly associated with treatment adherence. Multivariate analysis determined that ‘Active’ personality trait increases the likelihood to better treatment adherence by 1.14 times (95% CI: 1.02, 1.28, p=0.018). Conclusion: We did not find any association between treatment adherence and the presence of anxiety or depression. However, higher scores in ‘Active’ personality trait increases the likelihood of better treatment adherence among adult HIV on ART.

The Trends of Endodontic and Prosthodontic Treatment by Postgraduate Students in University of Malaya

@#This study is aimed to provide an insight into the types of treatment carried out by postgraduate students in the past 10 years. A retrospective study was carried out between November 2019 and February 2020 by deriving data from postgraduate students’ clinical logbooks of three different cohorts of Master of Clinical Dentistry (Restorative Dentistry in Conservative Dentistry) in 2010, 2013 and 2016. This retrospective data was systematically extracted from the records and tabulated categorically using an Excel spreadsheet (Microsoft Office Excel 2019). A descriptive analysis was carried out to further evaluate the results. Overall, the types of treatment carried out in the field of endodontics and fixed prosthodontics has changed in the past 10 years. An increasing trend is seen in the placement of all ceramic crowns and primary root canal treatment procedures, while a decreasing pattern is evident for secondary root canal procedures and placement of dental bridges.

Comparison of Immediate Effects on Usage of Dual Polymer Artificial Tears on Changes in Tear Film Characteristics

@#Introduction: This study aimed to evaluate the short-term efficacy of two comparable formulation of dual-polymer artificial tears: Systane Hydration preservative (SH) and non-preservative (SHUD) in 60 minutes observation period compared to normal saline. Methods: Fifty participants involved in this prospective, double-masked randomised study. Viscosity and pH of artificial tears were evaluated using rheometer and digital pH-meter prior to tear film assessment. Tear break-up time (TBUT) and tear meniscus height (TMH) were measured at baseline, 5, 15 and 60 minutes after instillation. Tear ferning pattern (TFP) were compared between baseline and 60 minutes after instillation. One-way analysis of variance (ANOVA) and Independent T-test were used to evaluate the effects of SH and SHUD after instillation and comparison between each specific time-interval respectively. P-value of 0.05 was set as the level of significance. Results: The viscosity of SH and SHUD was 26.7cP and 32.73cP re-spectively with pH of 7.85 (SH) and 7.74 (SHUD). Both artificial tears showed significant increment in TBUT between baseline and 15 minutes (SH:5.82±1.063, p=0.01; SHUD:6.02±0.979, p<0.001), and 60 minutes (SH:6.22±0.616, p<0.001; SHUD:6.34±0.658, p<0.001). SHUD demonstrated significant increment in TMH at every measurement taken (0.1996±0.02449, p<0.001 at 5min, 0.2038±0.02276, p<0.001 at 15min and 0.2068±0.02094, p<0.001 at 60min). Likewise, in SH group, significant increment in TMH at 15 minutes (0.1994±0.02325, p<0.001) and 60 minutes (0.2012±0.02379, p<0.001) were noted. Both groups revealed improvement in TFP (both, p<0.001) at 60 minutes. No significant im-provement was noted in control group. Conclusion: Improvement in TMH was prominently faster in SHUD than SH, although both TBUT and TFP revealed comparable tears quality between both artificial tears.

The Outcomes of Team-based Learning on Test Performance, Cognitive Engagement and Motivation in Preclinical Anatomy Practical Classes

@#Introduction: Designing an engaging teaching strategy that enhances the clinical application of anatomy knowledge is important for effective learning. Hence, this study was carried out to evaluate the outcomes of team-based learning (TBL) approach on students’ learning during gross anatomy practical classes. Method: A randomised-controlled trial was conducted on 215 pre-clinical year medical students, who were divided into TBL and control groups. Both groups attended the same anatomy lecture before the practical session. The TBL group underwent three phases of activities, which were pre-practical assignment (Phase-1), individual and team readiness assurance tests followed by a debriefing session (Phase-2), and group application task (Phase-3). Concurrently, the control group received a reading material as their pre-practical assignment and attended a practical session in the form of an anatomy model demonstration. Pre- and post-practical assessments were measured 30 minutes before and after the practical sessions. The students’ cognitive engagement and motivation were also measured after the practical sessions. Results: The TBL group among the Year-1 students outperformed the control group in all the test performance measures. The TBL group of the Year-1 students was also found to have greater improvement of test scores compared to their control counterparts. The TBL group was found to have significantly higher cognitive engagement scores only among the Year-2 students. However, the internal motivation scores were not significant in both cohorts. Conclusion: These results indicate that the TBL session contributes positive outcomes to students’ learning in anatomy context.

In silico prediction and in vitro analysis of bacteriocin and probiotic properties of Weissella cibaria NM1 isolated from Asian sea bass

Aims@#This study aims to predict the presence of bacteriocin- and probiotic-associated genes in the genome of Weissella cibaria NM1 isolated from Asian sea bass using a machine learning-based NeuBI prediction approach, followed by the investigation of the crude bacteriocin antimicrobial and probiotic properties via in vitro analysis.@*Methodology and results@#This study utilized the machine learning-based NeuBI prediction approach with a homology search of highly conserved bacteriocin-associated genes present in the genome of W. cibaria NM1. This approach discovered a putative bacteriocin gene (WC_2064) and bacteriocin operon with complete immunity, transporter, regulator and modifier genes. Furthermore, the genome of W. cibaria NM1 was found to harboured specific probiotic*associated genes that would contribute to acid and bile tolerance, adhesion on thehost cell and exhibited cholesterolreducing ability. On top of that, the genome also shows the absence of virulence and antibiotic resistance genes, which signifies the safety of W. cibaria NM1 as a potential probiotic candidate. In vitro study has confirmed the antipseudomonal activity of crude bacteriocin NM1 with MIC of 62.5 mg/mL. Weissella cibaria NM1 can tolerate 0.3% (v/v) of bile salt condition and the transit through the simulated gastric (pH 3 and 4) and small intestinal (pH 8) tract.@*Conclusion, significance and impact of study@#Current findings suggested in silico approach can speed up the search for putative bacteriocin and probiotic-associated genes from the genome of W. cibaria NM1. Nevertheless, further verification through experimental works will be deemed essential.

Antiproliferative and apoptosis effect of hyptolide from Hyptis pectinata (L.) Poit on human breast cancer cells

Hyptolide was isolated from the leaves of Hyptis pectinata (L.) Poit and was studied in order to discover and develop ananticancer drug. Hyptolide was obtained as a crystal of 87°C–88°C melting point. Spectroscopic identification resultsshow a wave number at 1,735 cm−1 indicating the presence of α,β-unsaturated δ-lactone. Gas chromatography-massspectrometry (GC-MS) analysis provides a single peak in the retention time of 11.701 by m/z value at 239, whichindicates explicitly hyptolide. The objective of this research was to evaluate the hyptolide’s mechanism of cytotoxicon MCF-7 human breast cancer cells in positive estrogen receptor. The assay test to 3-(4,5-dimethylthiazol-2-yl)-2,5-dphenyl tetrazolium bromide (MTT) showed that hyptolide exhibited cytotoxic effects on MCF-7 and T47D breastcancer cells with an IC50 value of 76.76 and 181.55 µg/ml, respectively. Interestingly, the treatment of hyptolide for 24,48, and 72 hours decreased cell viability on MCF-7 with dose- and time-dependent manner compared to untreated cells.Results of acridine orange-ethidium bromide multiple staining assay revealed that hyptolide induced apoptosis in a dosedependent manner. It can be concluded that hyptolide possesses antiproliferative effects through apoptosis induction

Effects of shading on the growth, development and yield of winged bean (Psophocarpus tetragonolobus) / Efeitos do sombreamento no crescimento, desenvolvimento e produtividade do feijão alado (Psophocarpus tetragonolobus)

ABSTRACT: An experiment was conducted to investigate the effects of different shading regimes [i.e., 60% (heavy), 30% (moderate), and 0% (control)] on 25 traits associated with the morphological features, photosynthetic gas exchange and agronomic characteristics of winged bean (Psophocarpus tetragonolobus), an underutilized protein-rich legume from the tropics. Collectively, 80% of the studied variables displayed significant differences (P<0.05) between at least two shade treatments. Shading generally showed most pronounced effect on the physiological traits of the legume, whereby the stomatal conductance, photosynthetic and transpiration rate differed significantly among plants for all treatments. The non-shaded plants were observed to have superior growth and physiological responses than the shaded plants. Interestingly, the moderately shaded plants exhibited the highest yield per plant, which significantly differed from the non-shaded and heavily shaded plants. This indicated that winged bean can adapt to partial canopy cover, making it a potential nitrogen-fixing cash crop which can be planted together with fruit or oil trees in commercial plantations.

RESUMO: Foi conduzido um experimento para investigar os efeitos de diferentes regimes de sombreamento [60% (pesado), 30% (moderado) e 0% (controle)] em 25 características associadas às características morfológicas, trocas gasosas fotossintéticas e características agronômicas de feijão alado (Psophocarpus tetragonolobus), leguminosa subutilizada rica em proteínas dos trópicos. Coletivamente, 80% das variáveis ​​estudadas apresentaram diferenças significativas (P<0,05) entre pelo menos dois tratamentos à sombra. O sombreamento mostrou efeito mais pronunciado nas características fisiológicas da leguminosa, pelo que a condutância estomática, a taxa fotossintética e a transpiração diferiram significativamente entre as plantas em todos os tratamentos. Observou-se que as plantas não sombreadas apresentaram crescimento e respostas fisiológicas superiores às plantas sombreadas. Curiosamente, as plantas moderadamente sombreadas exibiram o maior rendimento por planta, que diferiu significativamente das plantas não sombreadas e fortemente das sombreadas. Isso indica que o feijão alado pode se adaptar a cobertura parcial do dossel, tornando-o uma cultura potencial de fixação de nitrogênio que pode ser plantada em conjunto com árvores frutíferas ou oleaginosas em plantações comerciais.

Intraocular Pressure: the Effect of Short-term Fasting and Its Association With Fluid and Fat Status

@#Introduction: Short-term fasting may influence intraocular pressure (IOP) due to alteration of fluid (total body water; TBW, and water intake) and fat (total body fat; TBF). This study aimed: i) to compare IOP values within and between, fasting and non-fasting periods; and ii) to assess the association between IOP and, TBW and TBF. Methods: Thirty healthy participants aged 21.8±1.1 years were assessed on two different periods (fasting vs. non-fasting). During each period, the IOP, TBW and TBF values were assessed for four times (morning, afternoon, evening, late-evening). The IOP was measured using AccuPen® tonopen, while TBW and TBF were assessed by using a Tanita body composition analyser. Results: During fasting, the IOP value in the afternoon (14.53±2.33 mmHg) was significantly higher than in the evening (12.43±2.73 mmHg, p=0.009) and late-evening (12.60±2.44 mmHg, p=0.003). No significant difference in IOP was observed during non-fasting period. The mean of IOP in the evening was significantly lower during fasting compared to non-fasting (12.43±2.73 mmHg vs 13.75±2.53 mmHg, p=0.044). The IOP and TBW were negatively correlated (r=-0.268; p=0.011) during non-fasting and showed no association during fasting period. There was no significant correlation between IOP and TBF during both fasting and non-fasting periods. Conclusion: IOP reduction during short-term fasting, together with the no association with TBF and TBW suggested that IOP is an independent factor that reduces during fasting in healthy population.

Characteristics Of Cognitive Status Of Epilepsy Patients Treated With Monotherapy Of First-Generation Antiepileptic Drugs

@#Epilepsy is one of the main health problems in neurology that can lead to cognitive decline. Generally, the epilepsy-associated cognitive decline is influenced by demographic, clinical, and treatment characteristics. This study aimed to determine the characteristics of cognitive status of epilepsy patients who received monotherapy using first-generation antiepileptic drugs (AEDs), namely phenytoin, carbamazepine, and valproic acid. It involved 93 epilepsy patients of Mutiara Sukma Mental Hospital (n=38) and Mataram General Hospital (n=55). Besides, 93 healthy patients were assigned as healthy control group (HC) subjects (n=93). Demographic characteristics collected from epilepsy and HC groups were age, gender, and years of education. Clinical characteristics taken from both groups were MoCA-Ina score. Clinical characteristics taken from epilepsy group were age at epilepsy onset, type of seizure (partial vs generalized), etiology (idiopathic vs structural), first-generation AED used, years of treatment, and cognitive status. The result of the study revealed that there were no significant different between the two groups in the means of age and years of education as well as the frequency of male gender (p>0.05). The mean of MoCA-Ina score of epilepsy group was significantly lower compared with HC group (p<0.05). The frequency of cognitive decline among epilepsy patients was 75.3%. The cognitive functions of epilepsy patients using monotherapy with carbamazepine, phenytoin, or valproic acid was significantly lower compared with healthy subjects. We conclude that there was high prevalence of epilepsy-associated cognitive impairment which was associated with male gender.

Lip Print Analysis in Malaysian Chinese Population (Klang Valley): Lipstick-Cellophane Tape Technique (Analisis Cap Bibir Populasi Cina Malaysia di Lembah Klang: Teknik Gincu-Pita Selofan) / Jurnal Sains Kesihatan Malaysia

@#Cheiloscopy is recognized as a tool for personal identification due to its strength in criminalistics. In this study, the lip print of Malaysian Chinese population in Klang Valley was used for gender determination using lipstick-cellophane technique. 412 subjects (203 males and 209 females) were selected conveniently. Lipstick was first applied on the lips and the lip print was lifted using cellophane tape prior to pasting them onto a plain A4 paper and analysis using magnifying glass. Six topography areas of lip prints were classified using Suzuki and Tsuchihashi’s classification, including upper left, upper middle, upper right, lower right, lower middle and lower left. Chi-square test showed that all lip sections were significantly different from each other (p < 0.05). Type II was the dominant pattern in four lip sections for both genders: upper left (male 81.3%, female 57.4%), upper right (male 71.9%, female 42.9%), lower left (male 98.0%, female 90.0%) and lower right (male 96.1%, female 86.1%). Type IV was the dominant pattern for both middle part of the lips; upper middle (male 56.2%, female 50.7%) and lower middle (male 62.6%, female 50.2%). The results showed that gender can be differentiated based on lip print patterns. This finding suggested that cheiloscopy could be used in aiding personal identification for forensic investigation.

Knowledge, Attitude and Practice Regarding Pertussis among a Public University Students in Malaysia

Abstract Objective: To study the knowledge, attitude, and practice (KAP) regarding pertussis among students in a public university in Malaysia. Material and Methods: This study was a cross-sectional study using convenience sampling to recruit 171 respondents. The data was collected using a self-administered questionnaire comprised of four different parts: the socio-demographic data, the knowledge, the attitude and the practice towards the prevention of pertussis. The data were analyzed using correlation, independent t-test, and ANOVA according to the different study objectives and types of data. Results: More than half of the respondents (67.8%) indicated that they had heard about pertussis. The school or university (59.6%) was the most common source of information, followed by Internet (46.2%). The most of the respondents (43.9%) possessed moderate knowledge regarding pertussis and knew that Bordetella pertussis is the causative agent of pertussis (76.0%). A significant positive correlation between knowledge regarding pertussis with age (p=0.023) was observed, however, there was no association between age with attitude and practice (p=0.272 and 0.131, respectively). Gender and marital status did not influence the KAP regarding pertussis; nevertheless, significantly different between different faculties. Conclusion: Students from the Faculty of Medicine had the highest knowledge scores, while the students from the Faculty of Nursing had the most top attitude and practice scores compared to students from another faculty. The students from the public university generally had a good level of KAP regarding pertussis.

A comparison of antibacterial inhibitory effect on Streptococcus mutans and tensile strength between chitosan-based bonding adhesives and commercial products

Background: Adhesive bonding is the material used to attach a bracket to the enamel surface of the tooth. Streptococcus mutans contributes to enamel demineralization during orthodontic treatment. Objectives: To analyze the antimicrobial inhibitory effect of Streptococcus mutans bacteria and tensile strength of chitosan and CaCO3-based adhesive bonding material. Materials and Methods: The investigation constituted laboratory experimental research featuring analytical observation and a random sampling method. The antibacterial inhibitory effect of chitosan and CaCO3-based adhesive bonding against Streptococcus mutans involved six groups: two control groups using commercial light cure and self-cure adhesive bonding products and four groups using adhesive bonding consisting of 75% CaCO3 + 17.6% Bis-GMA + 22.4% MMA with various percentages of chitosan composition (A1: 25%, A2: 50%, A3: 75%, and A4: 100%) each group consisting of two samples (n = 12). A diametric test was conducted consisting of three samples (n = 15) to measure the tensile strength of each group. Data were analyzed by a combination of one-way analysis of variance and least significant difference tests. Result: The antibacterial inhibitory effect showed significant differences between groups (A1: 2.9467 ± 0.4163, A2: 3.6500 ± 0.6245, A3: 5.1267 ± 0.2517, A4: 4.7267 ± 0.9238; P = 0.0000; P < 0.05). A diametric tensile strength test confirmed significant differences between groups (A1: 7.2733 ± 5.0046, A2: 6.7667 ± 4.4346, A3: 6.4533 ± 2.9994, A4: 1.0058 ± 1.0058, K1: 15.6167 ± 3.1250; P = 0.009; P < 0.05). Conclusion: Chitosan-based adhesive bonding with good tensile strength has an antibacterial inhibitory effect against Streptococcus mutans.

Aspergillus species from groundnuts (Arachis hypogaea) and mycotoxin production by toxigenic species

Aims@#Groundnut is an important food crop and is susceptible to contamination by Aspergillus. The present study was conducted to identify Aspergillus spp. from groundnuts as well as to detect mycotoxin production by toxigenic species. @*Methodology and results@#Molecular identification using ITS region, β-tubulin and calmodulin genes identified six species, A. niger, A. tubingensis, A. flavus, A. aculeatus, A. sydowii and A. fumigatus. Phylogenetic tree of combined sequences showed the isolates from the same species were grouped with reference strains in the same clade, thus the species identity was confirmed. Detection of mycotoxin biosynthesis genes can give an indication of mycotoxin production. Two ochratoxin A genes, PKS15KS and PKS15C-MeT were detected in seven A. niger isolates but none of the isolates produced ochratoxin A when quantification was conducted using Ultra-High Performance Liquid Chromatography. Two aflatoxin B1 biosynthesis genes, Nor-1 (norsolorinic acid) and Ver-1 (Versicolorin) genes were detected in A. flavus but only KDH7 and KL27b isolates produced aflatoxin B1 with concentrations of 1.0 μg/g and 1.1 μg/g, respectively. @*Conclusion, significance and impact of study@#Various species of Aspergillus found on groundnuts may lead to potential mycotoxin contamination as toxigenic species were also recovered. The occurrence of Aspergillus spp. can reduce the quality of the legumes as well as reducing their shelf life.

Morphology, Leaf Gas Exchange and Quality of Pegaga (Centella asiatica) under Different Nitrogen Fertilization Rates

Aims: To investigate the physiological, leaf gas exchange and quality of Centella asiatica (pegaga) under different nitrogen fertilization rates. Study Design: Centella asiatica were exposed to four different nitrogen fertilization rates (0, 50, 100, 150 kg/ha) using urea (46% N) as nitrogen sources. The experiment was conducted in a randomized complete block (RCBD) design with three replications. Each treatment consisted of eight plants making the total of plants used in this study is 96 plants. Place and Duration of Study: Department of Biology, Faculty of Science, Universiti Putra Malaysia From May 2016-June 2016. Methodology: The growth parameters measured include total leaves numbers, leaf area, total chlorophyll content and total plant biomass. The carbon assimilation parameters were measured using LICOR 6400 XT Portable Photosynthesis System i.e net photosynthesis (A), Transpiration rate (E) and water use efficiency (WUE). Total phenolic and flavonoids contents from the leaves extracts were measured using Folin-Ciocalteu reagents. Results: The growth parameters such as leaves number, chlorophyll content, leaf area and total biomass were significantly influenced by nitrogen fertilization (P≤ 0.05), However, there were no significant difference observed between 50, 100 and 150 kg N/ha suggesting that 50 kg N/ha was the efficient rates to apply to enhance the growth of this plant. Meanwhile, the net photosynthesis (A) and water use efficiency (WUE) were enhanced with the increasing rate of nitrogen from 0>150 kgN/ha. The production of total phenolics and flavonoids was found to be highest under 100 kg/ha. The harvest index of total phenolics also showed the applications of 100 kg/ha gave the highest harvest index compared to the other nitrogen treatments. Conclusion: This study indicated growth and carbon assimilation parameters were enhanced under higher nitrogen fertilization and production of secondary metabolites was decreased with high rates of nitrogen. The recommended nitrogen fertilization for C. asiatica was at 100 kg N /ha, where it obtained the highest harvest index.

Impacts of Elevated CO2 on Growth, Carbohydrate Assimilation and Nutrient Uptake of Elaeis guineesis Jacq Seedlings

Aims: This study was conducted to characterize the growth patterns of tenera oil palm seedlings performance (Deli AVROS) under elevated CO2, that is expected to increase in the future due to climate change. Study Design: The palms were exposed to three carbon enrichment treatments: (1) ambient CO2 (400 ppm); (2) twice ambient CO2 (800 ppm), and (3) thrice ambient CO2 (1200 ppm). Randomized complete block design (RCBD) with three replications was used during the experiment using Deli AVROS seedlings. Place and Duration of Study: Department of Biology, Faculty of Science Universiti Putra Malaysia from March 2017 to December 2017. Methodology: Carbon dioxide enrichment treatments started when seedlings reached three months old by exposing them to three levels of CO2, i.e., ambient CO2 (400 ppm), twice ambient CO2 (800 ppm) and thrice ambient CO2 (1,200 ppm). Growth, carbohydrate and macronutrients properties were measured at the end of the treatment period of 3 months. Results: It was found that CO2 had the greatest influence on the growth over the three months’ period of experiment. As the level of CO2 increased, from 400>800>1200 ppm, the plant height, number of frond per plant, basal diameter, leaf area per seedling, root biomass, total dry matter, net assimilation rate (NAR) and relative growth rate (RGR) was significant increased between the CO2 levels. The enhanced plant growth under elevated CO2 might be contributed by increased in production of total non-structural carbohydrate (TNC) of the palm under elevated CO2. The increased in TNC exposed to elevated CO2 was supported by increase in sucrose and starch content under these conditions. More sucrose was available than starch indicate that no feedback inhibition was occurred and the palm have enough sink strength to cope with elevated CO2. The macronutrients contents (N, P, K, Ca, Mg) also was found to be reduced under elevated CO2 treatments, indicated that growth enhancement under elevated have dilute the nutrient content in the palms. Conclusion: In conclusion, the growth of oil palm seedlings was enhanced with elevated CO2 at double and triple concentration than the ambient. It was found that the increase might be due to increase in production of total non-structural carbohydrate. The enhanced growth also increased the macronutrient demands under the elevated levels of CO2. This show in future the palm needs more fertilizers with enhanced levels of elevated CO2.