A review of the ichthyofauna of Malaysian peat swamp forest

A review of literature showed that numerous intensive surveys have been carried out on the ichthyofauna of the peat swamp forests (PSFs) of Malaysia. This review aims to provide a checklist of blackwater fish species in Malaysia from available published literature, and address their economical importance, conservation status and problems of PSFs. A total of 198 peat swamp fish species from 32 families have been recorded in Malaysia. From this number, a total of 114 species from 23 families, representing about 40% of the known fish fauna in Peninsular Malaysia, were recorded from north Selangor PSF. Meanwhile, a total of 49 species belonging to 18 families, 13 species from seven families, 58 species belonging to 19 families, and nine species from five families were recorded from the peat swamps of Perak, Johor, Pahang and East Peninsular Malaysia (parts of Pahang and Terengganu), respectively. Meanwhile, 31 species from 12 families and 40 species belonging to 13 families were recorded from Sabah and Sarawak, respectively. Family Cyprinidae has the highest recorded species, followed by Osphronemidae, Bagridae and Siluridae. The IUCN Red List revealed 12 threatened species facing risk of extinction. The importance of conserving PSFs was outlined and suggestions made in line with the objectives of conservation. Findings from literature revealed that Malaysia's PSFs are rich in fish diversity, contrary to previous belief, and should therefore be conserved and protected to ensure the richness of their fish diversity

Water quality, primary productivity and carbon capture potential of microalgae in two urban manmade lakes, Selangor, Malaysia

The impact of climate change and weather conditions in small urban manmade lake is less understood. Most studies are done bimonthly or monthly without reference to weather conditions. The contribution of these small manmade lakes to carbon sequestration was largely ignored. There is not much study about water quality and primary production in relation to weather conditions and weekly observations in tropical lakes. Therefore, this study investigates the potential of using microalgae in freshwater bodies to mitigate global warming through carbon dioxide fixation in urban small manmade lakes. A comparative study for water quality and primary productivity in two manmade lakes was done from September 2014 to July 2015. Weekly sampling in triplicate for 500 ml water samples were done for phytoplankton biomass analysis, alkalinity and nutrient analysis, from the surface of the lake at 0.5m depth. Three sets of 4 BOD bottles were used to measure biological oxygen demand and primary productivity. Physical parameters were measured from surface water by Yellow Spring Instrument multi parameter probe model (YSI-556 MPS ). Water transparency was measured by Secchi disk a nd rain rainfall using rain gauge. Daily recording of weather was done at three times a day, then the weather was classified into three weather conditions. Statistical analyses were done by one-way ANOVA, and principal component analysis (PCA). The average water qualit y parameters of the lake during all weather conditions were : water temperature (28.95 ̊C) & (29.43 ̊C), pH(7.14) & (7.11), electrical conductivity (0.15 mScmˉ¹) & (0.41 mScm ˉ¹), dissolved oxygen (5.5 mg Lˉ1) & (4.5 mg Lˉ1), alkalinity (43.8 mgCaCo3/L) & (148.2 mgCaCo3/L), rthophosphates (0.02mg L’/) & (0.42 mg Lˉ1), nitrate-itrogen (0.20 mg Lˉ1) & (0.07 mg Lˉ1), ammonium- nitrogen ( 0.06 mg Lˉ1) & (0.96 mg Lˉ1), trophic status index (20.6) & (37.5) in Engineering lake and Seri Serdang Lake respectively. High averages of chlorophyll -a concentration were (0.71± 0.10 μ g Lˉ¹) & (3.47 ± 0.96 μ g Lˉ¹) during dry weather conditions in Engineering lake and Seri Serdang Lake respectively. Temporal fluctuations of primary production occurred in Engineering lake and Seri Serdang Lake with average of (0.57± 0.09 mg C Lˉ¹ hˉ¹) & (2.86 ± 0.37 mg C L ˉ¹ hˉ¹) respectively. A principal component analysis extracted two components after Varimax rotation and they contributed (22.50 % &15.56 %) and (28.95% &18.14%) in Engineering lake and Seri Serdang lake respectively. The we ather conditions such cloud covers and rain fall that significantly influence light intensity and water quality which in turn influence primary productivity in both lakes. Water quality, primary productivity and carbon capture potential of microalgae in two urban manmade lakes, Selangor, Malaysia

Selected morphological changes in nauplii of brine shrimp (Artemia salina) after tributyltin chloride (TBTCl) exposure

Early life stage of organisms is a critical period because it is very sensitive to changes that occur in the surrounding. The present study aimed to determine the lethal concentration 50 (LC) and identify 50 morphological changes of brine shrimp (Artemia salina) nauplii exposed to tributyltin chloride (TBTCl) after 24hr exposure. Results showed the LC of TBTCl for A. salina nauplii was 469.08 ng.L. Significant differences 50 1 were discovered in the morphology of nauplii in control and those exposed. The nauplii underwent prominent abnormal growth in total length, head width, abdominal width and tail width. Other abnormalities included improper development of mandibles, underdeveloped endopod and endite, as well as swimming site in the second pair of antenna. These results indicated that TBTCl is an environmentally toxic substance with negative effects on non-target organism. Therefore, further in-depth investigation should be conducted to establish A. salina as a bioindicator for TBTCl contamination

The distribution and biological aspects of Indonesian short-fin eel, Anguilla bicolor bicolor and giant mottled eel, Anguilla marmorata in the northwest of Peninsular Malaysia

This study describes the distribution and biology of Indonesian short-fin eel, Anguilla bicolor bicolor and giant mottled eel, Anguilla marmorata collected in the northwest of Peninsular Malaysia. A total of 33 specimens of A. b. bicolor were collected from Sungai Batu Pahat, Kuala Perlis and downstream of Sungai Pinang, while five specimens of A. marmorata were collected from the upper stream of Sungai Pinang. The range of body mass and total length of A. b. bicolor and A. marmorata were 85.2-2012.1 g and 275.0-905.0 mm; and 240.1- 830.1g and498.0-756.0 mm, respectively. The individual gonadosomatic index (IG) value for A. b. bicolor collected from Perlis and Pulau Pinang indicated that 90.0% and 39.1% of the samples were in mature stages, respectively, while for A. marmorata,the individual IG value indicates that all of the samples were still immature. The occurrence and distribution of A. b. bicolor was firstly reported in Perlis, Malaysia

ARL3 mutations cause Joubert syndrome by disrupting ciliary protein composition

Joubert syndrome (JBTS) is a genetically heterogeneous autosomal recessive neurodevelopmental ciliopathy. We investigated further the underlying genetic etiology of Joubert syndrome by studying two unrelated families in whom JBTS was not associated with pathogenic variants in known JBTSrelated genes. Combined autozygosity mapping of both families highlighted a candidate locus on chromosome 10 (chr10: 101569997-109106128 (hg 19)), and exome sequencing revealed two missense variants in ARL3 within the candidate locus. The encoded protein, ADP Ribosylation Factor-Like GTPase 3, ARL3, is a small GTP-binding protein that is involved in directing lipid-modified proteins into the cilium in a GTP-dependent manner. Both missense variants replace the highly conserved Arg149 residue, which we show to be necessary for the interaction with its guanine nucleotide exchange factor ARL13B, such that the mutant protein is associated with reduced INPP5E and NPHP3 localisation in cilia. We propose that ARL3 provides a potential hub in the network of encoded ciliopathy genes, whereby perturbation of ARL3 results in the mislocalisation of multiple ciliary proteins due to abnormal displacement of lipidated protein cargo

User Selective Encryption Method for Securing MANETs

Security issue is getting important day by day. At present, there are a variety of methodologies to provide protection for data confidentiality. MANETs have lots of security challenges than traditional networks like infrastructureless and self-organizing requirements. As the MANETs are dynamic networks that’s make every transmission in such networks vulnerable to many attacks and improving security level becomes a main issue. This paper introduces a user selective encryption method by operating Data Encryption Standard (DES), Triple DES (3DES), Advanced Encryption Standard (AES) and the Diffie-Hellman Key Exchange (DHKE) protocol for key management in order to improve MANET security. Through the Network Simulator-2 (NS-2), the we investigate the performance of the proposed method in terms of data transfer time and network throughput for different data sizes and different sender-to-receiver number of hops. The results show the superiority of AES over other encryption algorithms. Furthermore, the effectiveness of our proposed method is verified through comparing our results with those obtained from previous studies

Decentralized H∞ Control of Interconnected Systems with Time-varying Delays

This paper focuses on the problem of delay dependent stability/stabilization of interconnected systems with time-varying delays. The approach is based on a new Lyapunov-Krasovskii functional. A decentralized delay-dependent stability analysis is performed to characterize linear matrix inequalities (LMIs) based on the conditions under which every local subsystem of the linear interconnected delay system is asymptotically stable. Then we design a decentralized state-feedback stabilization scheme such that the family of closedloop feedback subsystems enjoys the delay-dependent asymptotic stability for each subsystem. The decentralized feedback gains are determined by convex optimization over LMIs. All the developed results are tested on a representative example and compared with some recent previous ones

Investigation of Microstructure and Creep Properties of Sn-xSb Solder Alloys up to Peritectic Composition

Particle strengthening was studied in Sn-xSb (x=0.5–3.0 wt. %). Tensile deformation behavior of Sn-2.5 wt.% Sb is investigated at temperature ranging (298 - 343K) and under different constant loads ranging (5.1 - 14.0 MPa). The microstructure characteristics of the tested alloys have been obtained using x-ray diffraction. Morphological studies using optical microscope have been investigated to obtain correlation between the microstructure and mechanical behavior of the alloys. The improved strength is attributed to the uniform distribution of the SnSb intermetallic compound (IMC) inside b-Sn matrix. Based on the obtained stress exponent (n) and activation energy (Q), it is proposed that the dominant deformation mechanism is dislocation climb over the whole temperature range used

Peningkatan Kemampuan Keaksaraan Awal Menggunakan Jepitan Huruf Pada Anak Di Taman Kanak-Kanak Negeri Isompa Cabenge

Pada kegiatan pembelajaran di Kelompok B Taman Kanak-Kanak Negeri Isompa Cabenge ditemukan adanya masalah kurangnya kemampuan anak dalam mengenal keaksaraan awal. Penelitian ini bertujuan untuk meningkatkan kemampuan keaksaraan awal anak menggunakan media jepitan huruf. Penelitian ini menggunakan jenis Penelitian Tindakan Kelas. Data yang dikumpulkan dianalisis secara kualitatif. Dari hasil perbaikan pembelajaran dapat dilihat peningkatan kemampuan keaksaraan awal anak meningkat. Hasil penelitian menunjukkan bahwa melalui penggunaan jepitan huruf dapat meningkatkan kemampuan keaksaraan awal anak.Kata Kunci : Keaksaraan Awal. Jepitan Huruf