Rapid species identification of highly degraded agarwood products from Aquilaria using real-time PCR

Aquilaria species are well known for their expensive agarwood, which is utilized as it is, or used as ingredients in many consumer products. Species validation in agarwood products is important because agarwood price is source-species-dependent. The best approach to establish species identity depends on DNA, as conventional methods (i.e. through morphology) are unable to tell apart products from different Aquilaria sources. However, genomic DNA from processed agarwood is often under poor condition. To overcome this challenge, we adopted real-time PCR technology coupled with species-specific primers derived from single nucleotide polymorphisms (SNPs) in the chloroplast DNA matK and trnL-trnF sequences. We targeted three commercial Aquilaria species: Aquilaria crassna, Aquilaria malaccensis, and Aquilaria sinensis. Dissociation curves and melting points from real-time analysis were found to be distinct across the species tested. In this study, we demonstrate that the real-time PCR-based technique using species-specific primers is capable of differentiating the three major commercial species, i.e. A. crassna, A. malaccensis, and A. sinensis, even when using highly degraded agarwood products as starting material

Low Levels of p53 Protein and Chromatin Silencing of p53 Target Genes Repress Apoptosis in Drosophila Endocycling Cells

Apoptotic cell death is an important response to genotoxic stress that prevents oncogenesis. It is known that tissues can differ in their apoptotic response, but molecular mechanisms are little understood. Here, we show that Drosophila polyploid endocycling cells (G/S cycle) repress the apoptotic response to DNA damage through at least two mechanisms. First, the expression of all the Drosophila p53 protein isoforms is strongly repressed at a post-transcriptional step. Second, p53-regulated pro-apoptotic genes are epigenetically silenced in endocycling cells, preventing activation of a paused RNA Pol II by p53-dependent or p53-independent pathways. Over-expression of the p53A isoform did not activate this paused RNA Pol II complex in endocycling cells, but over-expression of the p53B isoform with a longer transactivation domain did, suggesting that dampened p53B protein levels are crucial for apoptotic repression. We also find that the p53A protein isoform is ubiquitinated and degraded by the proteasome in endocycling cells. In mitotic cycling cells, p53A was the only isoform expressed to detectable levels, and its mRNA and protein levels increased after irradiation, but there was no evidence for an increase in protein stability. However, our data suggest that p53A protein stability is regulated in unirradiated cells, which likely ensures that apoptosis does not occur in the absence of stress. Without irradiation, both p53A protein and a paused RNA pol II were pre-bound to the promoters of pro-apoptotic genes, preparing mitotic cycling cells for a rapid apoptotic response to genotoxic stress. Together, our results define molecular mechanisms by which different cells in development modulate their apoptotic response, with broader significance for the survival of normal and cancer polyploid cells in mammals

Morphometric sexing of little spiderhunter (Arachnothera longirostra) in Peninsular Malaysia

Sexual dimorphism is often directly linked to sexual selection, mating systems and resource partitioning, which are crucial in species conservation and management. Many avian species, including pollinator birds, are sexually dimorphic with respect to size and colour, yet, such differences may be subtle for some species. In this study, molecular sexing was performed in addition to determining morphological parameters that can aid in future sex determination of a common forest pollinator, the little spiderhunter (Arachnothera longirostra), in Peninsular Malaysia. Based on 23 captures made in four forests, two out of seven body measurements (i.e. wing and tail lengths) were useful in predicting the sexes of the bird with 100% accuracy. In addition, significant differences were found in the head, bill, and total body lengths. Such findings will facilitate more effective sex identification in future field studies, particularly in the case of juveniles

DNA barcoding of the endangered Aquilaria (Thymelaeaceae) and its application in species authentication of agarwood products traded in the market

The identification of Aquilaria species from their resinous non-wood product, the agarwood, is challenging as conventional techniques alone are unable to ascertain the species origin. Aquilaria is a highly protected species due to the excessive exploitation of its precious agarwood. Here, we applied the DNA barcoding technique to generate barcode sequences for Aquilaria species and later applied the barcodes to identify the source species of agarwood found in the market. We developed a reference DNA barcode library using eight candidate barcode loci (matK, rbcL, rpoB, rpoC1, psbA-trnH, trnL-trnF, ITS, and ITS2) amplified from 24 leaf accessions of seven Aquilaria species obtained from living trees. Our results indicated that all single barcodes can be easily amplified and sequenced with the selected primers. The combination of trnL-trnF+ITS and trnL-trnF+ITS2 yielded the greatest species resolution using the least number of loci combination, while matK+trnL-trnF+ITS showed potential in detecting the geographical origins of Aquilaria species. We propose trnL-trnF+ITS2 as the best candidate barcode for Aquilaria as ITS2 has a shorter sequence length compared to ITS, which eases PCR amplification especially when using degraded DNA samples such as those extracted from processed agarwood products. A blind test conducted on eight agarwood samples in different forms using the proposed barcode combination proved successful in their identification up to the species level. Such potential of DNA barcoding in identifying the source species of agarwood will contribute to the international timber trade control, by providing an effective method for species identification and product authentication

Performance evaluation of wireless controller area network (WCAN) using token frame scheme

In this paper, a proposed new wireless protocol so-called wireless controller area network is introduced. WCAN is an adaptation of its wired cousin, controller area network protocol. The proposed WCAN uses token frame scheme in providing channel access to nodes in the system. This token frame method follows the example used in wireless token ring protocol which is a wireless network protocol that reduces the number of retransmissions as a result of collisions. This scheme based on CAN protocol allows nodes to share a common broadcast channel by taking turns in transmitting upon receiving the token frame that circulates around the network for a specified amount of time. The token frame allows nodes to access the network one at a time, giving ‘fair’ chance to all nodes instead of competing against one another. This method provides high throughput in a bounded latency environment. The proposed WCAN protocol has been developed and simulated by means of QualNet simulator. The performances of this proposed protocol are evaluated from the perspective of throughput, end-to-end delay and packet delivery ratio, and are compared against the IEEE 802.11 protocol. Simulation results show that the proposed WCAN outperforms IEEE 802.11 based protocol by 62.5 % in terms of throughput with increasing network size. Also, it shows an improvement of 6 % compared to IEEE 802.11 standard at a higher data interval rate

Home appliances management system using Controller Area Network (CAN)

Smart homes can be a potential application which provides unobtrusive support for the normal users, elderly or disabled that wants to promote independent living. Generally, smart home consists of various sensors, controllers and home network that are placed around the house. This paper presents a simple home networking system by using Controller Area Network (CAN) as the main communication protocol to manage multiple home appliances. The proposed management system consists of three main components: central controller subsystem (CCS), CAN module and relay module. CCS is a simple server where a simple graphical user interface (GUI) is built with multiple command buttons to obtain the user inputs. The CAN module is distinguished as either master CAN node or slave CAN node. The master CAN node is a CAN module that is attached to CCS. In contrast, the CAN module that attached to the home appliance is known as slave CAN node. The user input signal that contains a CAN data frame broadcasts from master CAN node to all slave CAN nodes via CAN bus. Each data frame consists of an identifier that is compared by each slave CAN node. If the identifier is not matched, the signal will be discarded by the slave CAN node. Otherwise, the slave CAN node will decode the data frame and execute the given command. The relay module of this slave CAN node will either switch `ON' or `OFF' the corresponding home appliances. The proposed management system using CAN has the advantages of being simple in its design which contributes to the overall low cost. Moreover, the CAN network system is immune from the electrical interferences. Finally, the experimental results have shown that the proposed system is operating accurately and efficiently

Cross‑amplifcation of microsatellite markers across agarwood‑producing species of the Aquilarieae tribe (Thymelaeaceae)

Tree species in the Aquilarieae tribe of the Thymelaeaceae family produce agarwood, a natural product highly valued for its fragrance, but the species are under threat due to indiscriminate harvesting. For conservation of these species, molecular techniques such as DNA profiling have been used. In this study, we assessed cross-amplification of microsatellite markers, initially developed for three Aquilaria species (A. crassna, A. malaccensis, and A. sinensis), on ten other agarwood-producing species, including members of Aquilaria (A. beccariana, A. hirta, A. microcarpa, A. rostrata, A. rugosa, A. subintegra, and A. yunnanensis) and Gyrinops (G. caudata, G. versteegii, and G. walla), both from the Aquilarieae tribe. Primers for 18 out of the 30 microsatellite markers successfully amplified bands of expected sizes in 1 sample each of at least 10 species. These were further used to genotype 74 individuals representing all the 13 studied species, yielding 13 cross-amplifiable markers, of which only 1 being polymorphic across all species. At each locus, the number of alleles ranged from 7 to 23, indicating a rather high variability. Four markers had relatively high species discrimination power. Our results demonstrated that genetic fingerprinting can be an effective tool in helping to manage agarwood genetic resources by potentially supporting the chain-of-custody of agarwood and its products in the market

Home appliances controller using wireless controller area network (WCAN) system

This paper presents a wireless remote controller in which providing a wireless sensing solution for home users to operate essential household appliances, ranging from simple lightings to sophisticated electronic devices. A wireless protocol based on wireless token ring protocol (WTRP) has been modified, yielding wireless controller area network (WCAN) data centric communications, which is then proposed to be applied in managing concurrency control of home appliances. WCAN is an adaptation of its wired cousin, controller area network (CAN) protocol which has not being properly defined. The wireless controller communicates with the standalone server which in turn communicates with the rest of sensing nodes through WCAN system. Each node will be receiving command from the standalone server and based on the message identifier, either executing the command or discarding it. WCAN has been chosen to become the backbone network of the system as it offers an alternative solution when industrial mobile stations under certain constraints should continue to use CAN protocol as frame exchange protocol

Assessment of the genetic variation of Malaysian durian varieties using inter-simple sequence repeat markers and chloroplast DNA sequences

To date, 124 durian varieties have been registered with the Malaysian Department of Agriculture based on phenotypic characteristics. However, the levels and patterns of genetic variation among the varieties are still unknown. In this study, the leaves of 27 durian varieties were sampled from four durian orchards in Universiti Putra Malaysia, namely Bukit Ekspo, Putra Mart, Ladang Puchong and Ladang 5. Twenty five inter-simple sequence repeat (ISSR) primers were tested for PCR amplification on DNA samples. Twelve ISSR primers amplified 133 clear and reproducible DNA fragments and 122 (91.73%) were polymorphic, indicating a high level of genetic variation among these durian varieties. Primers flanking four chloroplast DNA (cpDNA) regions (trnL-trnF, atpB-rbcL and trnH-psbA intergenic spacers as well as the partial matK gene) were tested for PCR amplification. Two cpDNA regions (trnL-trnF and matK) were successfully amplified, but showed no variation in their DNA sequences, even when additional samples from Vietnam were included. The findings in this preliminary study lay a foundation for more comprehensive future studies on the genetic variation among durian varieties

GPS based child care system using RSSI technique

In today's society, missing child cases increases rapidly. Child care is a critical issue in solving this epidemic. Various systems and methods have been implemented in solving this crisis. In this paper, the global position system (GPS) based child care system is proposed to solve this problem. This system consists of two nodes; child and parent nodes, each carried by the child and parent respectively. The child node consists of a simple circuit that has a Bluetooth module and a GPS receiver. The parent node is a mobile device that has Bluetooth connection. The GPS technology helps to determine the exact position of the child. The parent node receives the location of the child and displays the information on a designed map using a GUI program that is embedded into the mobile device. Besides the location, the distance between parent and child can also be determined using Bluetooth connection. A data from received signal strength indicator (RSSI) is extracted out from the Bluetooth connection and is used as vital information in determining the distance between parent and child. An alert is triggered when the distance between the parent and child is far apart for a certain range. The proposed system proves to be useful as a locator that could locate missing and wandering child for the parents