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The identity of the Sarawak freshwater crab Parathelphusa oxygona Nobili, 1901, with description of a new species, Parathelphusa nobilii, from Western Kalimantan, Indonesia, Borneo (Crustacea: Brachyura: Gecarcinucidae)

Ng PK

Zootaxa, 2014;3774:31-44.
PMID: 24871403 DOI: 10.11646/zootaxa.3774.1.2

The identity of the common lowland freshwater crab in western Sarawak, Borneo, East Malaysia, Parathelphusa oxygona Nobili, 1901 (family Gecarcinucidae), is clarified. The species is redescribed and figured, and its taxonomy discussed. Specimens from western Kalimantan, Borneo, Indonesia, which have been referred to P. oxygona are here referred to a new species, Parathelphusa nobilii. The new species can be differentiated from congeners by its relatively more swollen branchial regions of the carapace, wider and lower external orbital tooth, relatively more slender male abdomen and a straight male first gonopod.
A new species of Scandarma (Crustacea: Brachyura: Sesarmidae) from Sabah, Borneo, Malaysia

Ng PK

Zootaxa, 2013;3652:289-94.
PMID: 26269831

A new species of terrestrial sesarmid crab, Scandarma raymondi, is described from Sabah, Malaysia. This is the third species in the genus; others are from Taiwan, Japan and Sarawak, Borneo. The new species differs from congeners in the live coloration, proportions of the carapace and ambulatory legs and morphologies of the male abdomen, chela and male first gonopod.
A new species of troglobitic crab of the genus Stygothelphusa Ng, 1989, from Sarawak, Malaysia (Crustacea: Decapoda: Brachyura: Gecarcinucidae)

Ng PK, Grinang J

Zootaxa, 2014;3774:90-6.
PMID: 24871408 DOI: 10.11646/zootaxa.3774.1.7

A new species of cave crab, Stygothelphusa antu new species, is described from limestone formations in Temurang, Sarawak, Malaysia. The new species is the most highly adapted to a cavericolous lifestyle among the four known species of Stygothelphusa, having a pale body pigmentation, reduced eyes and elongated pereopods. In contrast, the other three species have normal eyes that almost completely fill the orbits. The new species also differs from its congeners by a number of carapace, pereopod and gonopod characters.
Notes on Hexapodidae (Crustacea, Brachyura) from Indonesia and Malaysia, with description of a new species of Mariaplax Rahayu & Ng, 2014, from Lombok, Indonesia

Ng PK, Rahayu DL

Zootaxa, 2015 Jul 02;3981(1):125-37.
PMID: 26249983 DOI: 10.11646/zootaxa.3981.1.7

The male of Hexapinus latipes (De Haan, 1835), so far known only from female specimens, is described based on the material reported by De Man (1888) as "Hexapus sexpes". Material referred to "Hexapus sexpes" by Tesch (1918) is shown instead to belong to Hexapinus simplex Rahayu & Ng, 2014, and Hexapinus latus Rahayu & Ng, 2014, while his "Hexaplax megalops Doflein, 1904" belongs to Hexaplax aurantium Rahayu & Ng, 2014. A new species, Mariaplax aspera n. sp., is described from a female collected in Lombok, Indonesia. This new species most closely resembles M. narusei Rahayu & Ng, 2014, described from Japan, but differs by its relatively narrower carapace, shorter ambulatory legs, tuberculated third maxillipeds, and shorter telson.
The identity of the semiterrestrial crab Terrathelphusa kuchingensis (Nobili, 1901) (Crustacea: Decapoda: Brachyura: Gecarcinucidae), with descriptions of four new species from southwestern Sarawak, Borneo, Malaysia

Grinang J, Ng PK

Zootaxa, 2015;3946(3):331-46.
PMID: 25947695 DOI: 10.11646/zootaxa.3946.3.2

Four new species of semiterrestrial gecarcinucid crabs are described from limestone and sandstone habitats in southwestern Sarawak, Malaysia: Terrathelphusa aglaia n. sp., T. cerina n. sp., T. kundong n. sp., and T. mas n. sp. The taxonomy of T. kuchingensis (Nobili, 1901) is discussed, its precise identity ascertained from fresh material, and its actual distribution determined. This increases the number of Terrathelphusa species in Borneo to eight.
Synthesisation of design features for multifunctional stretcher concepts

Lim SH, Ng PK

J Med Eng Technol, 2021 Feb;45(2):145-157.
PMID: 33539247 DOI: 10.1080/03091902.2021.1873442

A stretcher is a lightweight and portable apparatus used to facilitate the movement of patients who require medical care. While its design and functions have been known to man for over 600 years, there is still much room for improvement with regard to comfortability, mobility and ergonomics aspects. This study aims to synthesise design features from patents, journals and products for the conceptualisation of multifunctional stretchers. Based on the conceptual synthesis of this study, if a stretcher is redesigned to be foldable, then less storage space would be required, thus allowing the paramedic or medical person to store more stretchers and attend to multiple patients at a time. In comparison to a regular stretcher, a foldable stretcher would not only be smaller and more portable but would also help medical personnel reach the patient in a timelier manner. A reduction in response time for emergency medical services might increase the survival rate among patients who are in critical conditions. In the aspect of multifunctionality, the medical person may also be able to respond to different types of medical transportation needs. Multifunctional stretchers can increase the versatility of emergency medical service teams in adapting to different situations at a reduced cost.
Terrathelphusa secula, a new species of semiterrestrial freshwater crab (Crustacea: Brachyura: Gecarcinucidae) from Sabah, East Malaysia, Borneo

Ng PK, Tan LW

Zootaxa, 2015;4007(3):445-9.
PMID: 26623825 DOI: 10.11646/zootaxa.4007.3.13

A new species of semiterrestrial gecarcinucid freshwater crab, Terrathelphusa secula, is described from Danum Valley in Sabah, East Malaysia, eastern Borneo. In the form of its carapace, third maxilliped, and male second gonopod, it most closely resembles T. ovis Ng, 1997, and T. telur Ng, 1997, from eastern Sarawak and Brunei, respectively. It differs markedly from these and other congeners in its proportionately much wider carapace, and a male first gonopod that is strongly curved and sickle-shaped.
Fulltext Radiation of the red algal parasite Congracilaria babae onto a secondary host species, Hydropuntia sp. (Gracilariaceae, Rhodophyta)

Ng PK, Lim PE, Phang SM

PLoS One, 2014;9(5):e97450.
PMID: 24820330 DOI: 10.1371/journal.pone.0097450

Congracilaria babae was first reported as a red alga parasitic on the thallus of Gracilaria salicornia based on Japanese materials. It was circumscribed to have deep spermatangial cavities, coloration similar to its host and the absence of rhizoids. We observed a parasitic red alga with morphological and anatomical features suggestive of C. babae on a Hydropuntia species collected from Sabah, East Malaysia. We addressed the taxonomic affinities of the parasite growing on Hydropuntia sp. based on the DNA sequence of molecular markers from the nuclear, mitochondrial and plastid genomes (nuclear ITS region, mitochondrial cox1 gene and plastid rbcL gene). Phylogenetic analyses based on all genetic markers also implied the monophyly of the parasite from Hydropuntia sp. and C. babae, suggesting their conspecificity. The parasite from Hydropuntia sp. has a DNA signature characteristic to C. babae in having plastid rbcL gene sequence identical to G. salicornia. C. babae is likely to have evolved directly from G. salicornia and subsequently radiated onto a secondary host Hydropuntia sp. We also recommend the transfer of C. babae to the genus Gracilaria and propose a new combination, G. babae, based on the anatomical observations and molecular data.
The Brachyura described by Thomas Roscoe Rede Stebbing and a listing of Stebbing's South African Crustacea for the Marine Investigations in South Africa (Crustacea: Decapoda)

Low ME, Ng PK

Zootaxa, 2013;3599:371-6.
PMID: 24613958 DOI: 10.11646/zootaxa.3599.4.5
Parathelphusa pardus, a new species of lowland freshwater crab from swamps in central Sumatra, Indonesia (Crustacea: Brachyura: Gecarcinucidae)

Ng PK, Riady R, Windarti W

Zootaxa, 2016 Feb 29;4084(4):495-506.
PMID: 27394277 DOI: 10.11646/zootaxa.4084.4.2

A new species of gecarcinucid freshwater crab of the genus Parathelphusa H. Milne Edwards, 1853, is described from freshwater swamp habitats in Pekanbaru, Riau Province, in central-eastern Sumatra, Indonesia. Parathelphusa pardus sp. nov., has a very distinctive colour pattern, and in this respect, resembles P. maindroni (Rathbun, 1902) from Sumatra and Peninsular Malaysia; P. batamensis Ng, 1992, from Batam Island, Indonesia; P. reticulata Ng, 1990, from Singapore; and P. oxygona Nobili, 1901, from western Sarawak. It can be distinguished from these species and congeners by a suite of carapace, ambulatory leg, thoracic sternal and most importantly, male first gonopod characters.
Fulltext Confidence in COVID-19 vaccines moderates the association between vaccination status and mental distress

Tan CM, Owuamalam C, Sarma VJ, Ng PK

Stress Health, 2023 Oct;39(4):744-752.
PMID: 36574671 DOI: 10.1002/smi.3216

Previous research has demonstrated that becoming vaccinated with the Coronavirus vaccine may lower mental distress. However, it remains uncertain whether this relationship holds amid concerns of vaccine side effects and doubts of the vaccine's protective capabilities. We presented three studies that showed how vaccine confidence negatively influences the relationship between vaccine uptake and mental distress. Using two-way fixed effects regression models, Study 1 analyzes longitudinal survey of respondents from Los Angeles County in the US, while Study 2 uses the same analytical strategy but generalises findings by analysing longitudinal data of participants across all 50 US states. Main results of both studies show that (i) vaccination uptake is linked with reduced mental distress among individuals with high vaccine confidence (ii) vaccine uptake has no effect on mental distress among individuals with low vaccine confidence. Lastly, Study 3 applies multilevel analysis to a large-scale pseudo-panel study of 15 developed countries. Results for the third study corroborate finding (i) but not (ii) in that the multinational study finds that vaccine uptake is actually associated with higher mental distress among individuals with low vaccine confidence. In sum, our paper shows that the palliative effect of vaccination on mental health only exists when vaccine confidence is high. Results are mixed on whether vaccination affects mental distress when individual vaccine confidence is low.
Fulltext A TRIZ-driven conceptualisation of finger grip enhancer designs for the elderly

Tan DWH, Ng PK, Noor EEM

F1000Res, 2021;10:392.
PMID: 34354817 DOI: 10.12688/f1000research.51705.1

Background: Elderly people with severe finger weakness may need assistive health technology interventions. Finger weakness impedes the elderly in executing activities of daily living such as unbuttoning shirts and opening clothes pegs. While studies have related finger weakness with ageing effects, there appears to be no research that uses an algorithmic problem-solving approach such as the theory of inventive problem-solving (TRIZ) to recommend finger grip assistive technologies that resolve the issue of finger weakness among the elderly. Using TRIZ, this study aims to conceptualise finger grip enhancer designs for elderly people. Methods: Several TRIZ tools such as the cause-and-effect chain (CEC) analysis, engineering contradiction, physical contradiction, and substance-field analysis are used to conceptualise solutions that assist elderly people in their day-to-day pinching activities. Results: Based on the segmentation principle, a finger assistant concept powered by a miniature linear actuator is recommended. Specific product development processes are used to further conceptualise the actuation system. The study concluded that the chosen concept should use a DC motor to actuate fingers through tendon cables triggered by a push start button. Conclusions: Finger pinch degradation worsens the quality of life of the elderly. A finger grip enhancer that assists in day-to-day activities may be an effective option for elderly people, not only for their physical but also their mental well-being in society.
Fulltext The Conceptual Development of a Multifunctional Stepladder for Older People and Caregivers

Gan KW, Ng PK, Liew KW, Ng YJ, Yeow JA

Int J Environ Res Public Health, 2022 Nov 03;19(21).
PMID: 36361278 DOI: 10.3390/ijerph192114399

Stepladders are compact, foldable ladders with flat steps and a platform. Despite all the research and design efforts, there are still limitations in terms of the multifunctionality, usability and simplicity of stepladders and related variants. By combining ideas, features and functions from patent literature, existing products and scientific journals, this study aims to conceptualise a multifunctional stepladder for improved usability. Five concepts are created, which are screened and evaluated against a set of criteria to select the best concept for improved usability, divided into three categories: simplicity, effectiveness and efficiency. The result is a versatile invention that functions as a stepladder, walker, wheelchair and Pilates chair, suitable for older people and caregivers in nursing homes. It allows medical records or supplies to be retrieved from high places without the need for inappropriate aids. The invention can replace wheelchairs and walkers and converts into a Pilates chair to provide a mobile exercise option for older people. The concept offers older people flexibility and independence in terms of mobility and healthcare, while saving space in the nursing home. Further design studies, prototyping and testing are needed before this idea can go into production.
Fulltext A TRIZ Approach for Designing a Smart Lighting and Control System for Classrooms Based on Counter Application with Dual PIR Sensors

Chong PL, Ismail D, Ng PK, Kong FY, Basir Khan MR, Thirugnanam S

Sensors (Basel), 2024 Feb 10;24(4).
PMID: 38400335 DOI: 10.3390/s24041177

Electrical energy is often wasted through human negligence when people do not switch off electrical appliances such as lighting after leaving a place. Such a scenario often happens in a classroom when the last person leaves the class and forgets to switch off the electrical appliances. Such wastage may not be able to be afforded by schools that are limited financially. Therefore, this research proposed a simple and cost-effective system that can analyze whether there is or is not a human presence in the classroom by applying a counter to count the total number of people entering and leaving the classroom based on the sensing signals of a set of dual PIR sensors only and then correlating this to automatically turn on or off the electrical appliances mentioned. The total number of people identified in the classroom is also displayed on an LCD screen. A TRIZ approach is used to support the ideation of the system. The system can switch on several electrical output loads simultaneously when the presence of people is detected and switch them off when there are no people in the classroom. The proposed system can be expanded to be used in homes, offices, and buildings to prevent the high cost of electricity consumption caused by the negligence of people. This enables smarter control of electricity consumption.
Fulltext Genetic and morphological analyses of Gracilaria firma and G. changii (Gracilariaceae, Rhodophyta), the commercially important agarophytes in western Pacific

Ng PK, Lin SM, Lim PE, Hurtado AQ, Phang SM, Yow YY, et al.

PLoS One, 2017;12(7):e0182176.
PMID: 28759629 DOI: 10.1371/journal.pone.0182176

Many studies classifying Gracilaria species for the exploitation of agarophytes and the development of the agar industry were conducted before the prevalence of molecular tools, resulting in the description of many species based solely on their morphology. Gracilaria firma and G. changii are among the commercially important agarophytes from the western Pacific; both feature branches with basal constrictions that taper toward acute apices. In this study, we contrasted the morpho-anatomical circumscriptions of the two traditionally described species with molecular data from samples that included representatives of G. changii collected from its type locality. Concerted molecular analyses using the rbcL and cox1 gene sequences, coupled with morphological observations of the collections from the western Pacific, revealed no inherent differences to support the treatment of the two entities as distinct taxa. We propose merging G. changii (a later synonym) into G. firma and recognize G. firma based on thallus branches with abrupt basal constrictions that gradually taper toward acute (or sometimes broken) apices, cystocarps consisting of small gonimoblast cells and inconspicuous multinucleate tubular nutritive cells issuing from gonimoblasts extending into the inner pericarp at the cystocarp floor, as well as deep spermatangial conceptacles of the verrucosa-type. The validation of specimens under different names as a single genetic species is useful to allow communication and knowledge transfer among groups from different fields. This study also revealed considerably low number of haplotypes and nucleotide diversity with apparent phylogeographic patterns for G. firma in the region. Populations from the Philippines and Taiwan were divergent from each other as well as from the populations from Malaysia, Thailand, Singapore and Vietnam. Establishment of baseline data on the genetic diversity of this commercially important agarophyte is relevant in the context of cultivation, as limited genetic diversity may jeopardize the potential for its genetic improvement over time.
Fulltext Complete chloroplast genome of Gracilaria firma (Gracilariaceae, Rhodophyta), with discussion on the use of chloroplast phylogenomics in the subclass Rhodymeniophycidae

Ng PK, Lin SM, Lim PE, Liu LC, Chen CM, Pai TW

BMC Genomics, 2017 Jan 06;18(1):40.
PMID: 28061748 DOI: 10.1186/s12864-016-3453-0

BACKGROUND: The chloroplast genome of Gracilaria firma was sequenced in view of its role as an economically important marine crop with wide industrial applications. To date, there are only 15 chloroplast genomes published for the Florideophyceae. Apart from presenting the complete chloroplast genome of G. firma, this study also assessed the utility of genome-scale data to address the phylogenetic relationships within the subclass Rhodymeniophycidae. The synteny and genome structure of the chloroplast genomes across the taxa of Eurhodophytina was also examined.
RESULTS: The chloroplast genome of Gracilaria firma maps as a circular molecule of 187,001 bp and contains 252 genes, which are distributed on both strands and consist of 35 RNA genes (3 rRNAs, 30 tRNAs, tmRNA and a ribonuclease P RNA component) and 217 protein-coding genes, including the unidentified open reading frames. The chloroplast genome of G. firma is by far the largest reported for Gracilariaceae, featuring a unique intergenic region of about 7000 bp with discontinuous vestiges of red algal plasmid DNA sequences interspersed between the nblA and cpeB genes. This chloroplast genome shows similar gene content and order to other Florideophycean taxa. Phylogenomic analyses based on the concatenated amino acid sequences of 146 protein-coding genes confirmed the monophyly of the classes Bangiophyceae and Florideophyceae with full nodal support. Relationships within the subclass Rhodymeniophycidae in Florideophyceae received moderate to strong nodal support, and the monotypic family of Gracilariales were resolved with maximum support.
CONCLUSIONS: Chloroplast genomes hold substantial information that can be tapped for resolving the phylogenetic relationships of difficult regions in the Rhodymeniophycidae, which are perceived to have experienced rapid radiation and thus received low nodal support, as exemplified in this study. The present study shows that chloroplast genome of G. firma could serve as a key link to the full resolution of Gracilaria sensu lato complex and recognition of Hydropuntia as a genus distinct from Gracilaria sensu stricto.

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