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Fulltext Where and how are roads endangering mammals in Southeast Asia's forests?

Clements GR, Lynam AJ, Gaveau D, Yap WL, Lhota S, Goosem M, et al.

PLoS One, 2014;9(12):e115376.
PMID: 25521297 DOI: 10.1371/journal.pone.0115376

Habitat destruction and overhunting are two major drivers of mammal population declines and extinctions in tropical forests. The construction of roads can be a catalyst for these two threats. In Southeast Asia, the impacts of roads on mammals have not been well-documented at a regional scale. Before evidence-based conservation strategies can be developed to minimize the threat of roads to endangered mammals within this region, we first need to locate where and how roads are contributing to the conversion of their habitats and illegal hunting in each country. We interviewed 36 experts involved in mammal research from seven Southeast Asian countries to identify roads that are contributing the most, in their opinion, to habitat conversion and illegal hunting. Our experts highlighted 16 existing and eight planned roads - these potentially threaten 21% of the 117 endangered terrestrial mammals in those countries. Apart from gathering qualitative evidence from the literature to assess their claims, we demonstrate how species-distribution models, satellite imagery and animal-sign surveys can be used to provide quantitative evidence of roads causing impacts by (1) cutting through habitats where endangered mammals are likely to occur, (2) intensifying forest conversion, and (3) contributing to illegal hunting and wildlife trade. To our knowledge, ours is the first study to identify specific roads threatening endangered mammals in Southeast Asia. Further through highlighting the impacts of roads, we propose 10 measures to limit road impacts in the region.

Matched MeSH terms: Motor Vehicles/statistics & numerical data*
Fulltext Weakest bus frequency identification of power system via TFDI

Athraa Iessa, Noor Izzri Abdul Wahab, Norman Mariun

Pertanika Journal of Science & Technology, 2017;25(102):97-104.
MyJurnal

One of the concerns in power system preventive control and security assessment is to find the point where the voltage and frequency collapse and when the system forces a severe disturbance. Identifying the weakest bus in a power system is an essential aspect of planning, optimising and post-event analysing procedures. This paper proposes an approach to identify the weakest bus from the frequency security viewpoint. The transient frequency deviation index for the individual buses is used as the weakest bus identification as well as a frequency security indicator. This approach will help to determine the bus with the worst deviation, which helps to analyse the system disturbance, takes proper control action to prevent frequency failure, and most importantly, observes consumer frequency. The approach is applied to the WSCC 9 bus test system to show the feasibility of the method.

Matched MeSH terms: Motor Vehicles
Vehicular traffic noise prediction and propagation modelling using neural networks and geospatial information system

Ahmed AA, Pradhan B

Environ Monit Assess, 2019 Feb 26;191(3):190.
PMID: 30809746 DOI: 10.1007/s10661-019-7333-3

This study proposes a neural network (NN) model to predict and simulate the propagation of vehicular traffic noise in a dense residential area at the New Klang Valley Expressway (NKVE) in Shah Alam, Malaysia. The proposed model comprises of two main simulation steps: that is, the prediction of vehicular traffic noise using NN and the simulation of the propagation of traffic noise emission using a mathematical model. First, the NN model was developed with the following selected noise predictors: the number of motorbikes, the sum of vehicles, car ratio, heavy vehicle ratio (e.g. truck, lorry and bus), highway density and a light detection and ranging (LiDAR)-derived digital surface model (DSM). Subsequently, NN and its hyperparameters were optimised by a systematic optimisation procedure based on a grid search approach. The noise propagation model was then developed in a geographic information system (GIS) using five variables, namely road geometry, barriers, distance, interaction of air particles and weather parameters. The noise measurement was conducted continuously at 15-min intervals and the data were analysed by taking the minimum, maximum and average values recorded during the day. The measurement was performed four times a day (i.e. morning, afternoon, evening, and midnight) over two days of the week (i.e. Sunday and Monday). An optimal radial basis function NN was used with 17 hidden layers. The learning rate and momentum values were 0.05 and 0.9, respectively. Finally, the accuracy of the proposed method achieved 78.4% with less than 4.02 dB (A) error in noise prediction. Overall, the proposed models were found to be promising tools for traffic noise assessment in dense urban areas.

Matched MeSH terms: Off-Road Motor Vehicles; Motor Vehicles
Fulltext Using simulation model as a tool for analyzing bus service reliability and implementing improvement strategies

Moosavi SMH, Ismail A, Yuen CW

PLoS One, 2020;15(5):e0232799.
PMID: 32379848 DOI: 10.1371/journal.pone.0232799

Bus services naturally tend to be unstable and are not always capable of adhering to schedules without control strategies. Therefore, bus users and bus service providers face travel time variation and irregularity. After a comprehensive review of the literature, a significant gap was recognized in the field of public transportation reliability. According to literature, there is no consistency in reliability definition and indicators. Companies have their own definition of bus service reliability, and they mostly neglect the passengers' perspective of reliability. Therefore, four reliability indicators were selected in this study to fill the gap in the literature and cover both passengers' and operators' perceptions of reliability: waiting time and on-board crowding level from passengers' perspective, and headway regularity index at stops (HRIS) and bus bunching/big gap percentage from operators' perspective. The primary objective of this research is to improve the reliability of high frequency of bus service and simulation tools currently being used by the public transportation companies. Therefore, a simulation model of bus service was developed to study the strategies to alleviate it. Four different types of strategies were selected and implemented according to Route U32 (Kuala Lumpur) specifications. Model out-put showed that control strategies such as headway-based dispatching could significantly improve headway regularity by almost 62% and the waiting time by 51% on average. Both holding strategies at key stops (previous and Prefol holding) have shown an almost similar impact on reliability indicators. Waiting time was reduced by 44% and 43% after the previous and Prefol Headway strategies were adopted, respectively. However, the implementation of the component of headway-based strategies at the terminal and key stops showed the best impact on reliability, in terms of passenger waiting time. Waiting time and excess waiting time were both significantly reduced by 52.86% and 81.44%, respectively. Nevertheless, the strategies did not show any significant positive effect on the level of crowding during morning peak hours.

Matched MeSH terms: Motor Vehicles
Tyre-blast injuries

Murty OP

J Forensic Leg Med, 2009 May;16(4):224-7.
PMID: 19329081 DOI: 10.1016/j.jflm.2008.12.027

A teenager college student was fatally injured by burst tyre air pressure while waiting on a public bus stand to catch a bus to reach her college at Kuala Lumpur. She accidentally came near the wheel while boarding when tube and tyre got burst .The air pressure had blown the girl in the air and she subsequently fell on a rough surface. The iron-locking rim of the wheel acted as a missile and hit the girl. She died on her way to the hospital. A medico-legal autopsy was performed which showed extensive injuries in the cranial and chest cavity. Head had large scalp laceration with diffuse separation and gaping from in the vault region; skull bones were fractured. Chest cavity had extensive rib fractures, lacerated lungs and haemo-thorax while externally there was no obvious injury. It requires intensive care management and screening of the victims. Tyre-blast injuries are not so common. This case exposes the hazard due to burst tyre.

Matched MeSH terms: Motor Vehicles*
Fulltext Traumatic globe displacement into anterior cranial fossa

Patricia Ann John, Sylves Patrick, Mohtar Ibrahim, Adil Hussein

Malaysian Journal of Medicine and Health Sciences, 2020;16(3):325-327.
MyJurnal

A 64-year-old Malay gentleman alleged occupational injury when a malfunctioned metal hydraulic door hit on his face while unloading sand from his tipper-truck. Post-trauma, he complained of right eye (RE) pain and total loss of vision. On examination, noted RE visual acuity was unable to be assessed and left eye (LE) was 6/24 with pinhole 6/9. No eyeball could be seen in the right socket with superior orbital rim step deformity and left periorbital haema- toma. Computed tomography scan of the brain and orbit confirmed displaced right eye globe into the right anterior cranial fossa with right and left multiple orbital wall fractures. He then underwent successful right eye globe reposi- tioning. Traumatic orbital roof fracture is a rare condition. Repositioning of the eye globe was done to salvage the eye globe for a cosmetic reason and to avoid localised inflammatory reaction at the anterior cranial fossa.

Matched MeSH terms: Motor Vehicles
Fulltext Translation and validation of the Malay post traumatic stress disorder checklist for civilians

Rafidah Bahari, Muhammad N Mohamad Alwi, Muhammad R Ahmad, Ismail Mohd Saiboon

ASEAN Journal of Psychiatry, 2015;16(2):203-211.
MyJurnal

There are a number of validated questionnaires available for the screening of Post-Traumatic Stress Disorder (PTSD), and the PTSD Checklist for Civilians is one of them. However, none was translated into the Malay Language and validated for use in the Malaysian population. The aim of this study is to translate and validate the Malay PTSD Checklist for Civilians (MPCL-C). Methods: The PCL-C was translated into the Malay Language and back-translated. The reliability and validity of the MPCL-C were then determined by administering them to those who presented at the emergency department for motor vehicle accident at least one month before. Results: The MPCL-C has good face and content validity. In terms of reliability, it is also good, with Chronbach’s alpha values of 0.90, 0.77, 0.75 and 0.74 for the full scale, re-experiencing, avoidance and arousal domains respectively. Conclusions: The MPCL-C is a valid and reliable instrument to screen for PTSD in motor vehicle accident victims for the studied population.

Matched MeSH terms: Motor Vehicles
Fulltext The influence of agitation on oil substrate dispersion and oxygen transfer in Pseudomonas aeruginosa USM-AR2 fermentation producing rhamnolipid in a stirred tank bioreactor

Nur Asshifa MN, Zambry NS, Salwa MS, Yahya ARM

3 Biotech, 2017 Jul;7(3):189.
PMID: 28664380 DOI: 10.1007/s13205-017-0828-0

Water-immiscible substrate, diesel, was supplied as the main substrate in the fermentation of Pseudomonas aeruginosa USM-AR2 producing rhamnolipid biosurfactant, in a stirred tank bioreactor. In addition to the typical gas-aqueous system, this system includes gas-hydrocarbon-aqueous phases and the presence of surfactant (rhamnolipid) in the fermentation broth. The effect of diesel dispersion on volumetric oxygen transfer coefficient, k L a, and thus oxygen transfer, was evaluated at different agitations of 400, 500 and 600 rpm. The oxygen transfer in this oil-water-surfactant system was shown to be affected by different oil dispersion at those agitation rates. The highest diesel dispersion was obtained at 500 rpm or impeller tip speed of 1.31 m/s, compared to 400 and 600 rpm, which led to the highest k L a, growth and rhamnolipid production by P. aeruginosa USM-AR2. This showed the highest substrate mixing and homogenization at this agitation speed that led to the efficient substrate utilization by the cells. The oxygen uptake rate of P. aeruginosa USM-AR2 was 5.55 mmol/L/h, which showed that even the lowest k L a (48.21 h-1) and hence OTR (57.71 mmol/L/h) obtained at 400 rpm was sufficient to fulfill the oxygen demand of the cells. The effect of rhamnolipid concentration on k L a showed that k L a increased as rhamnolipid concentration increased to 0.6 g/L before reaching a plateau. This trend was similar for all agitation rates of 400, 500 and 600 rpm, which might be due to the increase in the resistance to oxygen transfer (k L decrease) and the increase in the specific interfacial area (a).

Matched MeSH terms: Motor Vehicles
The impact of heart rate-based drowsiness monitoring on adverse driving events in heavy vehicle drivers under naturalistic conditions

Wolkow AP, Rajaratnam SMW, Wilkinson V, Shee D, Baker A, Lillington T, et al.

Sleep Health, 2020 06;6(3):366-373.
PMID: 32340910 DOI: 10.1016/j.sleh.2020.03.005

OBJECTIVES: This study examined the influence of a wrist-worn heart rate drowsiness detection device on heavy vehicle driver safety and sleep and its ability to predict driving events under naturalistic conditions.
DESIGN: Prospective, non-randomized trial.
SETTING: Naturalistic driving in Malaysia.
PARTICIPANTS: Heavy vehicle drivers in Malaysia were assigned to the Device (n = 25) or Control condition (n = 34).
INTERVENTION: Both conditions were monitored for driving events at work over 4-weeks in Phase 1, and 12-weeks in Phase 2. In Phase 1, the Device condition wore the device operated in the silent mode (i.e., no drowsiness alerts) to examine the accuracy of the device in predicting driving events. In Phase 2, the Device condition wore the device in the active mode to examine if drowsiness alerts from the device influenced the rate of driving events (compared to Phase 1).
MEASUREMENTS: All participants were monitored for harsh braking and harsh acceleration driving events and self-reported sleep duration and sleepiness daily.
RESULTS: There was a significant decrease in the rate of harsh braking events (Rate ratio = 0.48, p

Matched MeSH terms: Motor Vehicles*
Fulltext The encapsulation of flavourzyme in nanoliposome by heating method

Jahadi M, Khosravi-Darani K, Ehsani MR, Mozafari MR, Saboury AA, Pourhosseini PS

J Food Sci Technol, 2015 Apr;52(4):2063-72.
PMID: 25829586 DOI: 10.1007/s13197-013-1243-0

The main objective of this study was to use heating method (HM) to prepare liposome without employing any chemical solvent or detergent. Plackett-Burman design (PBD) was applied for the screening of significant process variables including the lecithin proportion, the cholesterol/lecithin ratio, the pH of solution for liposome preparation, the enzyme/lecithin ratio, the stirring time, the process temperature, the speed of stirrer, the ratio of stirrer to the tank diameter, the application of homogenization, the method of adding enzyme and centrifugation conditions on the encapsulation efficiency (EE %) of liposome and the activity of liposomal Flavourzyme (LAPU(-1)) (P

Matched MeSH terms: Motor Vehicles
The effect of job and environmental factors on job satisfaction in automotive industries

Dawal SZ, Taha Z

Int J Occup Saf Ergon, 2006;12(3):267-80.
PMID: 16984786

A methodology was developed for diagnosing industrial work, which includes questionnaire, observation, measurements, data collection and statistical analysis. A survey was conducted to investigate the relationship between job satisfaction and factors that affect work design in 2 automotives manufacturing companies in Malaysia. A basic work design model was proposed. The aim of this model was to determine the factors that influence employees' perception towards their work. A set of multiple-choice questionnaires was developed and data was collected by interviewing employees at a production plant. The survey focused on job and environmental factors. The results supported the proposed model and showed that job and environmental factors were significantly related to job satisfaction. They highlighted the significant influence of age, work experience and marital status on job satisfaction. Further, environmental factors, especially the surroundings, context dependence and the building's function, also had a significant impact on job satisfaction.

Matched MeSH terms: Motor Vehicles*
Fulltext The application of factor analysis to identify sources in Klang Valley aerosol

Shamsiah A. Rahman, Mohd Suhaimi Hamzah, Abdul Khalik Wood, Md Suhaimi Elias, Nazaratul Ashifa Abdullah Salim, Ezwiza Sanuri

Journal of Nuclear and Related Technologies, 2009;2009(1):288-296.
MyJurnal

Chemical composition of fine (PM2.5) aerosol samples collected for the 5 years period (2001- 2005) using Gent Stacked filter unit sampler at Klang Valley (3 o 10 ’ 30 ’’ N, 101 o 43 ’ 24 ’’ E) were analysed using Neutron Activation Analysis (NAA) and Proton Induced X-ray Emission (PIXE). Results of the study show that the major component of the fine aerosol was black carbon and sulfur with the mass concentration ranged from 4.4 - 6.7µg m -3 and 1.2 - 1.9µg m -3 , respectively. The total fine aerosol mass concentration were in the ranged of 25 - 31µg m -3 with the reconstructed mass was about 50% as relative to the gravimetric mass. Statistical method, factor analysis with varimax approach has been applied to the aerosol composition data for the fingerprint identification. The analysis produces five identified fingerprint represent soil, industry, motor vehicles/biomass burning and Pb and Zn sources. There is also an unidentified source that could be related to unknown industrial activities.

Matched MeSH terms: Motor Vehicles
Fulltext The Physical And Psychological Morbidity In Maxillofacial Trauma Patients

Au Yong, S.W. L., Ummu Aiman, Y., Rahman, Z.A.A.

Ann Dent, 1999;6(1):-.
MyJurnal

The aim of this research is to study how the physical changes in the maxillofacial trauma patients affect them psychologically in patients of different ages, sexes, races, socioeconomic backgrounds, types and severity of injury. The study was conducted by doing a questionnaire survey, which was divided into physical and psychological components. In the physical component, the questions were mainly related to the physical injuries to the patient, which could be visualized clinically and functionally. The psychological component consisted of analyzing the impact of the maxillofacial trauma to the psychological profile. Twenty patients of both sexes and ages, ranged from 15 to 62 years old were interviewed. The main cause of trauma was from motor vehicle accidents. This study appears to show that maxillofacial trauma may have a psychological impact on patients.

Matched MeSH terms: Motor Vehicles
Fulltext The Malay posttraumatic stress disorder checklist for DSM-5 (MPCLC-5) as screening tool for ptsd: determination of cut-off point against clinician administered PTSD scale for DSM-5 (CAPS-5)

Muhammad Najib Mohamad Alwi, Rafidah Bahari

Malaysian Journal of Medicine and Health Sciences, 2020;16(107):13-17.
MyJurnal

Introduction: Posttraumatic stress disorder (PTSD) is a mental health condition which develops following exposure to life-threatening events. This cross-sectional study was conducted among adult patients from all walks of life who had injuries related to motor vehicle accidents to determine the cut-off point of the Malay Posttraumatic Stress Disorder Checklist For DSM-5 (MPCLC-5) for its use as a screening tool for PTSD in the Malaysian population. Methods: Using convenient sampling method, 204 subjects who fulfilled the inclusion criteria were recruited and they were given the 17 item self-rated MPCLC-5 to fill up. Subsequently, trained personnel administered the gold standard Clinician Administered PTSD Scale for DSM 5 (CAPS-5). ROC curve analysis was done to determine appropriate cut-off point for the MPCLC-5. Results: Cut off point of 42/43 would yield the most preferable sensitivity and specificity for MPCLC-5 when compared to CAPS-5 (Sensitivity: 67.56% (95%CI 55.68% to 78.00%); Specificity : 80% (95% CI 72.08% to 86.50%) ). Conclusion: The easy to administer MPCLC-5 is suitable for screening of PTSD among local patients with a proposed cut off point of 42/43.

Matched MeSH terms: Motor Vehicles
The Association between risk factors and low back pain among commercial vehicle drivers in peninsular Malaysia: a preliminary result

Tamrin SB, Yokoyama K, Jalaludin J, Aziz NA, Jemoin N, Nordin R, et al.

Ind Health, 2007 Apr;45(2):268-78.
PMID: 17485871

To determine the risk factors associated with complain of low back pain. A cross sectional study was done from June 2004 until August 2005. Seven hundred and sixty commercial vehicle drivers from 11 bus companies in central, northern and eastern regions in Malaysia participated in this study. Modified Nordic questionnaire was used to determine the prevalence of low back pain; Maestro human vibration meter was used to measure the personal R.M.S values of lateral, anterior-posterior and vertical axes. Modified Owas was used to assess the awkward posture of the driver torso namely, bending forward movement, leaning, sitting straight and twisting. Profile of Mood States (POMS) was used to evaluate the mood states of bus drivers with complain of low back pain. A high prevalence of low back pain (60.4%) among Malaysian commercial vehicle drivers was found. Logistic regression analysis controlling for age, income, education level and non occupational activities revealed that the following factors were related to low back pain: Tension-anxiety [1.080, 95% CI 1.041-1.121], depression dejection [1.047, 95% CI 1.023-1.072], anger-hostility [1.053, 95% CI 1.027-1.081], fatigue [1.132, 95% CI 1.089-1.177] and confusion [1.114, 95% CI 1.061-1.169] of POMS, length of employment [1.001, 95% CI 1.0-1.003], steering wheel adjustment [1.521, 95% CI 1.101-2.101], perception of exposing to vibration [1.943, 95% CI 1.389-2.719]. In conclusion, combinations of risks lead to high increase of low back pain complain among Malaysian bus drivers.

Matched MeSH terms: Motor Vehicles*
Systemic Solutions for Addressing Non-Communicable Diseases in Low- and Middle-Income Countries

Ganju A, Goulart AC, Ray A, Majumdar A, Jeffers BW, Llamosa G, et al.

J Multidiscip Healthc, 2020;13:693-707.
PMID: 32801732 DOI: 10.2147/JMDH.S252300

Non-communicable diseases (NCDs) have been on the rise in low- and middle-income countries (LMICs) over the last few decades and represent a significant healthcare concern. Over 85% of "premature" deaths worldwide due to NCDs occur in the LMICs. NCDs are an economic burden on these countries, increasing their healthcare expenditure. However, targeting NCDs in LMICs is challenging due to evolving health systems and an emphasis on acute illness. The major issues include limitations with universal health coverage, regulations, funding, distribution and availability of the healthcare workforce, and availability of health data. Experts from across the health sector in LMICs formed a Think Tank to understand and examine the issues, and to offer potential opportunities that may address the rising burden of NCDs in these countries. This review presents the evidence and posits pragmatic solutions to combat NCDs.

Matched MeSH terms: Motor Vehicles
Fulltext Survey on health status of heavy vehicle drivers in Klang valley

Krishnan P, Hashim N, Rani U, Lung JK

Med J Malaysia, 1998 Dec;53(4):449-51.
PMID: 10971995

A survey was carried out using a medical examination format that was prepared by the Malaysian Medical Association. The findings of the survey show that of the 266 cases surveyed, 64 drivers (24% of cases surveyed) are either totally unfit to drive or temporarily unfit to drive heavy goods and passenger vehicles. This is clear indication that the current format that is being used by the Road Transport Department is inadequate and needs to be reviewed. It must also be stressed that all the above 64 drivers have been certified fit using the existing Road Transport Department format and are currently driving in our highways and roads. Heavy vehicle goods and passenger vehicle drivers if not properly examined and medically certified are not only be endangering their own lives but also that of others. It is therefore recommended that based on the data available from this survey, the Road Transport Department should seriously consider adopting the medical examination format that was formalised by the Malaysian Medical Association and used in this survey.

Matched MeSH terms: Motor Vehicles*
Fulltext Successful ankle replantation in two cases with different presentations

Wen APY, Jusoh MH, Saad AZM, Halim AS, Faisham NWIW, Azman WSW

Arch Plast Surg, 2020 Mar;47(2):182-186.
PMID: 31462030 DOI: 10.5999/aps.2018.00514

We report our experience of treating two patients with ankle amputation with different presentations. The first case was a clean-cut sharp amputation. The second case was an avulsion injury following a motor vehicle accident in a patient who arrived 8 hours after the injury. Replantation was successful in both cases. In avulsion injuries, a secondary operation for wound coverage is required at a later stage. With good strategy and a support team, encouraging limb survival outcomes are possible post-replantation.

Matched MeSH terms: Motor Vehicles
Fulltext Staged Surgery for Severe Soft Tissue and Bone Loss of the Knee

Chan, C.K., Goh, J.H., Ng, W.M., Kwan, M.K., Merican, A.M., Soong, K.L.

Malays Orthop J, 2010;4(2):40-43.
MyJurnal

A 20- year-old female student was involved in a motor vehicle accident. She sustained a severe friction injury to the left knee that resulted in considerable soft tissue and bone loss. There was also damage to the knee extensor mechanism, tibialis anterior muscle, femoral trochlea, the anterior half of the tibial plateau extending distally to the proximal tibia and skin. However, there was no crushing of the limb or resultant neurovascular deficit but cancellous bone and the remainder of the joint were exposed. Repeated surgical debridement was performed and was followed by covering of the soft tissue using a latissimus dorsi free flap and skin grafts. The bony defect was reconstituted with antibiotic bone cement to prevent flap adherence and shrinkage, enhance stability and prevent fracture. The cement was later removed at the time of arthrodesis at which time an ipsilateral double barrel vascularised fibular graft supplemented with autogenously cancellous bone and a ring fixator was used. Computer tomography confirmed union at three months post procedure. The fixator was then removed and a tibialis posterior transfer was performed.

Matched MeSH terms: Motor Vehicles
Fulltext Sound signatures and production mechanisms of three species of pipefishes (Family: Syngnathidae)

Lim AC, Chong VC, Wong CS, Muniandy SV

PeerJ, 2015;3:e1471.
PMID: 26734507 DOI: 10.7717/peerj.1471

Background. Syngnathid fishes produce three kinds of sounds, named click, growl and purr. These sounds are generated by different mechanisms to give a consistent signal pattern or signature which is believed to play a role in intraspecific and interspecific communication. Commonly known sounds are produced when the fish feeds (click, purr) or is under duress (growl). While there are more acoustic studies on seahorses, pipefishes have not received much attention. Here we document the differences in feeding click signals between three species of pipefishes and relate them to cranial morphology and kinesis, or the sound-producing mechanism. Methods. The feeding clicks of two species of freshwater pipefishes, Doryichthys martensii and Doryichthys deokhathoides and one species of estuarine pipefish, Syngnathoides biaculeatus, were recorded by a hydrophone in acoustic dampened tanks. The acoustic signals were analysed using time-scale distribution (or scalogram) based on wavelet transform. A detailed time-varying analysis of the spectral contents of the localized acoustic signal was obtained by jointly interpreting the oscillogram, scalogram and power spectrum. The heads of both Doryichthys species were prepared for microtomographical scans which were analysed using a 3D imaging software. Additionally, the cranial bones of all three species were examined using a clearing and double-staining method for histological studies. Results. The sound characteristics of the feeding click of the pipefish is species-specific, appearing to be dependent on three bones: the supraoccipital, 1st postcranial plate and 2nd postcranial plate. The sounds are generated when the head of the Dorichthyes pipefishes flexes backward during the feeding strike, as the supraoccipital slides backwards, striking and pushing the 1st postcranial plate against (and striking) the 2nd postcranial plate. In the Syngnathoides pipefish, in the absence of the 1st postcranial plate, the supraoccipital rubs against the 2nd postcranial plate twice as it is pulled backward and released on the return. Cranial morphology and kinesis produce acoustic signals consistent with the bone strikes that produce sharp energy spikes (discrete or merged), or stridulations between bones that produce repeated or multimodal sinusoidal waveforms. Discussion. The variable structure of the sound-producing mechanism explains the unique acoustic signatures of the three species of pipefish. The differences in cranial bone morphology, cranial kinesis and acoustic signatures among pipefishes (and seahorses) could be attributed to independent evolution within the Syngnathidae, which warrants further investigation.

Matched MeSH terms: Motor Vehicles

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