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A study towards the total synthesis of TAN1251B

Asnuzilawati Asari, Hayes CJ

Sains Malaysiana, 2009;38.

A synthetic route towards the synthesis of TAN1251B was developed utilizing an alkylidene carbene insertion reaction as a key step to construct the quartenary centre. The α-hydroxylation of the 5,6-spirocyclic enone with iodosobenzene was successful to give a mixture of diastereomer compounds 20 and 21 in 1:1.2 ratios.
Editorial: Bridging the gap between animal and human studies of hearing

Hall DA, Plack CJ

Hear Res, 2019 10;382:107778.
PMID: 31470340 DOI: 10.1016/j.heares.2019.107778
Differential effects of activated protein C on synovial fibroblasts in response to hypoxia and normoxia

Park YG, Choi J, Song I, Park SY, Seol JW, Jackson CJ

Sains Malaysiana, 2017;46:1895-1902.

Rheumatoid arthritis (RA) is a chronic disease characterized by inflammation of the joints and their lining or synovium. Previous studies showed that the synovium in RA patients is more hypoxic than normal synovium. Activated protein C (APC) has anticoagulant and anti-inflammatory effects and is highly expressed in the joints of RA patients. We examined the effect of APC on RA and normal synovial fibroblasts under hypoxic conditions. Human synovial fibroblasts were isolated from the synovial tissues of RA patients and normal controls and cells were exposed to recombinant APC under normoxic (21% oxygen) or hypoxic (1% oxygen) conditions. Cell proliferation was measured using MTT assays. Cell lysates and conditioned media were collected and assayed for matrix metalloproteinase (MMP)-2, MMP-9 and p38 using zymography and western blots. Proliferation of both normal and RA synovial fibroblasts dose-dependently increased after APC treatment in normoxic conditions. Under hypoxia, APC enhanced RA cell proliferation but had no effect on normal fibroblasts. MMP-2 production and activation were significantly augmented by APC in both cell types under normoxia and hypoxia conditions. However, activated MMP-2 was more reduced in cells under hypoxia than normoxia. APC substantially reduced the phosphorylation of p38 in normal and RA synovial fibroblasts under hypoxia. No difference in p38 phosphorylation was observed under normoxia. The receptor for APC, endothelial protein C receptor (EPCR), was elevated in normal fibroblasts under hypoxic conditions whereas in RA cells, EPCR was highly expressed under both normoxic and hypoxic conditions. We found that hypoxia enhanced the effect of APC on RA synovial fibroblasts through activation of MMP2 and inhibition of p38 phosphorylation. Our results suggested that APC may suppress joint destruction and progression of inflammation in a hypoxic RA environment.
Individual factors and perceptions of organization safety level: evidence from a manufacturing organization in Malaysia

Shah Rollah Abdul Wahab, Durrishah Idrus, Christopher J. Rees, Ishak Mad Shah

Journal of Occupational Safety and Health, 2011;8(1):33-48.
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Individual factors have been considered to be a key issue to organizations’ performance and survival. Specifically, previous studies provide evidence that individual factors are closely associated with accidents in the workplace. Therefore, this study seeks to investigate the relationship between individual factors and workplace safety. 50 respondents have been randomly chosen from a manufacturing company in Johor Bahru, Malaysia. Data are collected using a survey and are analyzed using SPSS version 16.0. A descriptive statistic, cross tabulation, independent sample t-test and one-way between groups ANOVA are employed to interpret findings of the study. Findings show that employees’ perception on safety performance is at high level (Mean= 115, Standard Deviation= 17.73). Furthermore, the results of cross tabulation demonstrate that individual factors play a key role to determine the organization safety performance level. Another significant finding reveals that there is a significant difference of safety performance mean to two of individual factors namely gender and tenure of service. Individual factors namely gender, age, tenure of service and academic qualification give a significant impact to employees’ perception on safety performance.
Trends in Self-Harm in Kuala Lumpur, 2005-2011

Armitage CJ, Abdul Rahim W, Rowe R, O'Connor RC

Arch Suicide Res, 2016;20(1):22-8.
PMID: 26649775 DOI: 10.1080/13811118.2015.1004493

Acts of self-harm are not routinely tracked in Malaysia. The present study investigates the prevalence of self-harm in Kuala Lumpur, Malaysia, over a 7-year period. The aims were to: (a) assess the prevalence of self-harm; (b) examine any changes over a period of 7 years, and (c) identify correlates of methods of self-harm. Data were extracted from the hospital records of Kuala Lumpur Hospital to review trends in self-harm between 2005 and 2011. There were 918 episodes of self-harm across the 7-year period, with a significant peak in 2007-2009. The average rate of self-harm (7.7 per 100,000 population per year) was similar or lower than the rate of suicide (6-8 or 8-13 per 100,000) suggesting that genuine cases of self-harm are often attributed to other causes. Nevertheless, over-representation of young people, women and Indians suggest areas in which resources to prevent self-harm might usefully be targeted. Estimating rates of self-harm are fraught with problems and further research is needed to understand the economic and cultural barriers around seeking treatment for self-harm, reporting self-harm and classifying self-harm.
Fulltext Two Monthly Continuous Dynamic Model Based on Nash Bargaining Theory for Conflict Resolution in Reservoir System

Homayounfar M, Zomorodian M, Martinez CJ, Lai SH

PLoS One, 2015;10(12):e0143198.
PMID: 26641095 DOI: 10.1371/journal.pone.0143198

So far many optimization models based on Nash Bargaining Theory associated with reservoir operation have been developed. Most of them have aimed to provide practical and efficient solutions for water allocation in order to alleviate conflicts among water users. These models can be discussed from two viewpoints: (i) having a discrete nature; and (ii) working on an annual basis. Although discrete dynamic game models provide appropriate reservoir operator policies, their discretization of variables increases the run time and causes dimensionality problems. In this study, two monthly based non-discrete optimization models based on the Nash Bargaining Solution are developed for a reservoir system. In the first model, based on constrained state formulation, the first and second moments (mean and variance) of the state variable (water level in the reservoir) is calculated. Using moment equations as the constraint, the long-term utility of the reservoir manager and water users are optimized. The second model is a dynamic approach structured based on continuous state Markov decision models. The corresponding solution based on the collocation method is structured for a reservoir system. In this model, the reward function is defined based on the Nash Bargaining Solution. Indeed, it is used to yield equilibrium in every proper sub-game, thereby satisfying the Markov perfect equilibrium. Both approaches are applicable for water allocation in arid and semi-arid regions. A case study was carried out at the Zayandeh-Rud river basin located in central Iran to identify the effectiveness of the presented methods. The results are compared with the results of an annual form of dynamic game, a classical stochastic dynamic programming model (e.g. Bayesian Stochastic Dynamic Programming model, BSDP), and a discrete stochastic dynamic game model (PSDNG). By comparing the results of alternative methods, it is shown that both models are capable of tackling conflict issues in water allocation in situations of water scarcity properly. Also, comparing the annual dynamic game models, the presented models result in superior results in practice. Furthermore, unlike discrete dynamic game models, the presented models can significantly reduce the runtime thereby avoiding dimensionality problems.
What do hearing healthcare professionals do to promote hearing aid use and benefit among adults? A systematic review

Ismail AH, Munro KJ, Armitage CJ, Dawes PD

Int J Audiol, 2019 02;58(2):63-76.
PMID: 30646766 DOI: 10.1080/14992027.2018.1531154

OBJECTIVE: To conduct a systematic review of the evidence in relation to what hearing healthcare professionals do during hearing aid consultations and identifying which behaviours promote hearing aid use and benefit among adult patients.
DESIGN: Searches were performed in electronic databases MEDLINE, EMBASE, CINAHL, PsycInfo, Web of Science, PubMed and Google Scholar. The Crowe Critical Appraisal Tool and Melnyk Levels of Evidence were used to assess quality and level of evidence of eligible studies. Behaviours of hearing healthcare professionals were summarised descriptively.
STUDY SAMPLE: 17 studies met the inclusion criteria.
RESULTS: Twelve studies described behaviours of audiologists and five studies were intervention studies. Audiologists were typically task- or technically-oriented and/or dominated the interaction during hearing aid consultations. Two intervention studies suggested that use of motivational interviewing techniques by audiologists may increase hearing aid use in patients.
CONCLUSIONS: Most studies of clinicians' behaviours were descriptive, with very little research linking clinician behaviour to patient outcomes. The present review sets the research agenda for better-controlled intervention studies to identify which clinician behaviours better promote patient hearing aid outcomes and develop an evidence base for best clinical practice.
A Systematic Review of the Psychometric Properties of Self-Report Measures of Attitudes to Aging

Faudzi FNM, Armitage CJ, Bryant C, Brown LJE

Res Aging, 2019 07;41(6):549-574.
PMID: 30700233 DOI: 10.1177/0164027518825117

The aim of this study was to describe and systematically evaluate the psychometric properties of attitudes to aging measures that have been validated in adults younger than 60 years. Studies were assessed for methodological quality using the COnsensus-based Standards for the selection of health Measurement INstruments. Best evidence synthesis was performed to summarize the levels of evidence. Systematic searching yielded 21 articles, relating to 10 different measures. Some instruments were validated only in middle-aged and older people, while others were validated in a wider age range. Measures differed in whether their items related to participants' own experiences of aging, their anticipated future aging, and/or aging in general. None of the measures had had all of its psychometric properties assessed. The Expectations Regarding Ageing-12 and the Anxiety About Ageing Scale received positive ratings for the greatest number of psychometric properties, but capture different constructs, and may be differentially suited to different age groups of younger adults.
Moderating effects of age on relationships between attitudes to aging and well-being outcomes

Faudzi FNM, Armitage CJ, Bryant C, Brown LJE

Aging Ment Health, 2020 10;24(10):1620-1626.
PMID: 31099260 DOI: 10.1080/13607863.2019.1619167

Objectives: More positive attitudes to aging are associated with better health and wellbeing outcomes. This study examined whether chronological age moderated relationships between attitudes to aging and wellbeing outcomes, and whether these relationships differ according to the specific attitudinal construct measured.Method: Participants were 911 adults aged 18-60 years (mean = 36.63 years). Attitudes to ageing were measured using the Malay Reactions to Ageing Questionnaire (M-RAQ), which focuses on respondents' anticipated reactions to being aged over 65 years, and the Malay Anxiety about Ageing Scale (M-AAS), which additionally captures respondents' fears and anxieties about current aging and older people. Wellbeing outcomes were measured using the Warwick- Edinburgh Mental Well-being Scale (WEMWBS) and the Satisfaction with Life Scale (SWLS).Results: More positive attitudes to ageing were associated with higher levels of wellbeing and life satisfaction after controlling for age, gender, education, and self-rated health. Age moderated the relationships between the M-AAS and wellbeing and life satisfaction, with stronger relationships in younger adults. No moderating effects of age were found for the M-RAQ.Conclusion: The difference in the moderating effects of age between measures suggests that the two attitudinal constructs captured by these two measures operate in different ways. In particular, the current emotional/anxiety components of attitudes to ageing may differentially affect wellbeing at different ages. This suggests that interventions aimed at the promotion of wellbeing through coping with aging-related anxieties might be particularly well-suited to younger adults, who may be less able to respond effectively to the anxieties they experience.
Fulltext Quantitative MS-Based Proteomics: Comparing the MCF-7 Cellular Response to Hypoxia and a 2-Oxoglutarate Analogue

Bush JT, Chan MC, Mohammed S, Schofield CJ

Chembiochem, 2020 06 02;21(11):1647-1655.
PMID: 31919953 DOI: 10.1002/cbic.201900719

The hypoxia-inducible factors (HIFs) are key transcription factors in determining cellular responses involving alterations in protein levels in response to limited oxygen availability in animal cells. 2-Oxoglutarate-dependent oxygenases play key roles in regulating levels of HIF and its transcriptional activity. We describe MS-based proteomics studies in which we compared the results of subjecting human breast cancer MCF-7 cells to hypoxia or treating them with a cell-penetrating derivative (dimethyl N-oxalylglycine; DMOG) of the stable 2OG analogue N-oxalylglycine. The proteomic results are consistent with reported transcriptomic analyses and support the proposed key roles of 2OG-dependent HIF prolyl- and asparaginyl-hydroxylases in the hypoxic response. Differences between the data sets for hypoxia and DMOG might reflect context-dependent effects or HIF-independent effects of DMOG.
Cultural Adaptations to the Measurement of Attitudes to Ageing: Psychometric Assessment of the Malay Reactions to Ageing Questionnaire

Faudzi FNM, Armitage CJ, Bryant C, Brown LJE

Assessment, 2020 09;27(6):1272-1284.
PMID: 29649886 DOI: 10.1177/1073191118766400

The aims of this study were to culturally adapt the Reactions to Ageing Questionnaire (RAQ) for a non-Western (Malay) population, and explore attitudes to ageing in relation to age, gender, and education. Eight new culturally relevant items were generated by asking Malay-speaking participants about their reactions to ageing. A Malay version of the extended 35-item RAQ was then administered to 911 Malaysian participants aged 18 to 60 years. Exploratory factor analysis revealed four factors. Three of the factors were similar to those identified in the original RAQ, while "Family and Religion" emerged as a new factor. More negative attitudes to ageing were observed in younger and female respondents. There were no effects of education. This culturally adapted RAQ exhibits robust psychometric properties, and could be used to assess attitudes to ageing in Malaysia and other Southeast Asian countries. Moreover, we have identified a "core set" of RAQ items that could be applicable worldwide.
Fulltext Molecular Mechanisms of Adipogenesis: The Anti-adipogenic Role of AMP-Activated Protein Kinase

Ahmad B, Serpell CJ, Fong IL, Wong EH

Front Mol Biosci, 2020;7:76.
PMID: 32457917 DOI: 10.3389/fmolb.2020.00076

Obesity is now a widespread disorder, and its prevalence has become a critical concern worldwide, due to its association with common co-morbidities like cancer, cardiovascular diseases and diabetes. Adipose tissue is an endocrine organ and therefore plays a critical role in the survival of an individual, but its dysfunction or excess is directly linked to obesity. The journey from multipotent mesenchymal stem cells to the formation of mature adipocytes is a well-orchestrated program which requires the expression of several genes, their transcriptional factors, and signaling intermediates from numerous pathways. Understanding all the intricacies of adipogenesis is vital if we are to counter the current epidemic of obesity because the limited understanding of these intricacies is the main barrier to the development of potent therapeutic strategies against obesity. In particular, AMP-Activated Protein Kinase (AMPK) plays a crucial role in regulating adipogenesis - it is arguably the central cellular energy regulation protein of the body. Since AMPK promotes the development of brown adipose tissue over that of white adipose tissue, special attention has been given to its role in adipose tissue development in recent years. In this review, we describe the molecular mechanisms involved in adipogenesis, the role of signaling pathways and the substantial role of activated AMPK in the inhibition of adiposity, concluding with observations which will support the development of novel chemotherapies against obesity epidemics.
Comparison of continuous sampling with active noise cancelation and sparse sampling for cortical and subcortical auditory functional MRI

Dewey RS, Hall DA, Plack CJ, Francis ST

Magn Reson Med, 2021 11;86(5):2577-2588.
PMID: 34196020 DOI: 10.1002/mrm.28902

PURPOSE: Detecting sound-related activity using functional MRI requires the auditory stimulus to be more salient than the intense background scanner acoustic noise. Various strategies can reduce the impact of scanner acoustic noise, including "sparse" temporal sampling with single/clustered acquisitions providing intervals without any background scanner acoustic noise, or active noise cancelation (ANC) during "continuous" temporal sampling, which generates an acoustic signal that adds destructively to the scanner acoustic noise, substantially reducing the acoustic energy at the participant's eardrum. Furthermore, multiband functional MRI allows multiple slices to be collected simultaneously, thereby reducing scanner acoustic noise in a given sampling period.
METHODS: Isotropic multiband functional MRI (1.5 mm) with sparse sampling (effective TR = 9000 ms, acquisition duration = 1962 ms) and continuous sampling (TR = 2000 ms) with ANC were compared in 15 normally hearing participants. A sustained broadband noise stimulus was presented to drive activation of both sustained and transient auditory responses within subcortical and cortical auditory regions.
RESULTS: Robust broadband noise-related activity was detected throughout the auditory pathways. Continuous sampling with ANC was found to give a statistically significant advantage over sparse sampling for the detection of the transient (onset) stimulus responses, particularly in the auditory cortex (P < .001) and inferior colliculus (P < .001), whereas gains provided by sparse over continuous ANC for detecting offset and sustained responses were marginal (p ~ 0.05 in superior olivary complex, inferior colliculus, medial geniculate body, and auditory cortex).
CONCLUSIONS: Sparse and continuous ANC multiband functional MRI protocols provide differing advantages for observing the transient (onset and offset) and sustained stimulus responses.
AgRP/NPY and POMC neurons in the arcuate nucleus and their potential role in treatment of obesity

Vohra MS, Benchoula K, Serpell CJ, Hwa WE

Eur J Pharmacol, 2022 Jan 15;915:174611.
PMID: 34798121 DOI: 10.1016/j.ejphar.2021.174611

Obesity is a major health crisis affecting over a third of the global population. This multifactorial disease is regulated via interoceptive neural circuits in the brain, whose alteration results in excessive body weight. Certain central neuronal populations in the brain are recognised as crucial nodes in energy homeostasis; in particular, the hypothalamic arcuate nucleus (ARC) region contains two peptide microcircuits that control energy balance with antagonistic functions: agouti-related peptide/neuropeptide-Y (AgRP/NPY) signals hunger and stimulates food intake; and pro-opiomelanocortin (POMC) signals satiety and reduces food intake. These neuronal peptides levels react to energy status and integrate signals from peripheral ghrelin, leptin, and insulin to regulate feeding and energy expenditure. To manage obesity comprehensively, it is crucial to understand cellular and molecular mechanisms of information processing in ARC neurons, since these regulate energy homeostasis. Importantly, a specific strategy focusing on ARC circuits needs to be devised to assist in treating obese patients and maintaining weight loss with minimal or no side effects. The aim of this review is to elucidate the recent developments in the study of AgRP-, NPY- and POMC-producing neurons, specific to their role in controlling metabolism. The impact of ghrelin, leptin, and insulin signalling via action of these neurons is also surveyed, since they also impact energy balance through this route. Lastly, we present key proteins, targeted genes, compounds, drugs, and therapies that actively work via these neurons and could potentially be used as therapeutic targets for treating obesity conditions.
Zoothamnium duplicatum infestation of cultured horseshoe crabs (Limulus polyphemus)

Shinn AP, Mühlhölzl AP, Coates CJ, Metochis C, Freeman MA

J Invertebr Pathol, 2015 Feb;125:81-6.
PMID: 25499897 DOI: 10.1016/j.jip.2014.12.002

An outbreak of the sessile peritrich Zoothamnium duplicatum in a pilot, commercial-scale Limulus polyphemus hatchery resulted in the loss of ∼96% (40,000) second/third instar larvae over a 61day period. peritrich growth was heavy, leading to mechanical obstruction of the gills and physical damage. The peritrichs were controlled without resultant loss of juvenile crabs by administering 10ppm chlorine in freshwater for 1h and the addition of aquarium grade sand; a medium into which the crabs could burrow and facilitate cleaning of the carapace. Peritrich identity was confirmed from a partial SSU rDNA contiguous sequence of 1343bp (99.7% similarity to Z. duplicatum).
Fulltext Completed suicides and self-harm in Malaysia: a systematic review

Armitage CJ, Panagioti M, Abdul Rahim W, Rowe R, O'Connor RC

Gen Hosp Psychiatry, 2015 Mar-Apr;37(2):153-65.
PMID: 25636361 DOI: 10.1016/j.genhosppsych.2014.12.002

Most of the research into suicide and self-harm has been conducted in the United States and Europe, yet the volume of research does not reflect the distribution of suicide globally, with Asia accounting for up to 60% of all suicides. The present study systematically reviews the literature to assess the prevalence and correlates of suicidal acts in Malaysia in Southeast Asia.
Transient isotachophoresis-capillary zone electrophoresis with contactless conductivity and ultraviolet detection for the analysis of paralytic shellfish toxins in mussel samples

Abdul Keyon AS, Guijt RM, Bolch CJ, Breadmore MC

J Chromatogr A, 2014 Oct 17;1364:295-302.
PMID: 25223612 DOI: 10.1016/j.chroma.2014.08.074

The accumulation of paralytic shellfish toxins (PSTs) in contaminated shellfish is a serious health risk making early detection important to improve shellfish safety and biotoxin management. Capillary electrophoresis (CE) has been proven as a high resolution separation technique compatible with miniaturization, making it an attractive choice in the development of portable instrumentation for early, on-site detection of PSTs. In this work, capillary zone electrophoresis (CZE) with capacitively coupled contactless conductivity detector (C(4)D) and UV detection were examined with counter-flow transient isotachophoresis (tITP) to improve the sensitivity and deal with the high conductivity sample matrix. The high sodium concentration in the sample was used as the leading ion while l-alanine was used as the terminating electrolyte (TE) and background electrolyte (BGE) in which the toxins were separated. Careful optimization of the injected sample volume and duration of the counter-flow resulted in limit of detections (LODs) ranging from 74.2 to 1020 ng/mL for tITP-CZE-C(4)D and 141 to 461 ng/mL for tITP-CZE-UV, an 8-97 fold reduction compared to conventional CZE. The LODs were adequate for the analysis of PSTs in shellfish samples close to the regulatory limit. Intra-day and inter-day repeatability values (percentage relative standard deviation, n=3) of tITP-CZE-C(4)D and tITP-CZE-UV methods for both migration time and peak height were in the range of 0.82-11% and 0.76-10%, respectively. The developed method was applied to the analysis of a contaminated mussel sample and validated against an Association of Official Analytical Chemists (AOAC)-approved method for PSTs analysis by high performance liquid chromatography (HPLC) with fluorescence detection (FLD) after pre-column oxidation of the sample. The method presented has potential for incorporation in to field-deployable devices for the early detection of PSTs on-site.
Capillary electrophoresis for the analysis of paralytic shellfish poisoning toxins in shellfish: comparison of detection methods

Keyon AS, Guijt RM, Gaspar A, Kazarian AA, Nesterenko PN, Bolch CJ, et al.

Electrophoresis, 2014 May;35(10):1496-503.
PMID: 24591173 DOI: 10.1002/elps.201300353

Paralytic shellfish toxins (PSTs) are produced by marine and freshwater microalgae and accumulate in shellfish including mussels, oysters, and scallops, causing possible fatalities when inadvertently consumed. Monitoring of PST content of shellfish is therefore important for food safety, with currently approved methods based on HPLC, using pre- or postcolumn oxidation for fluorescence detection (HPLC-FLD). CE is an attractive alternative for screening and detection of PSTs as it is compatible with miniaturization and could be implemented in portable instrumentation for on-site monitoring. In this study, CE methods were developed for C(4) D, FLD, UV absorption detection, and MS-making this first report of C(4) D and FLD for PSTs detection. Because most oxidized toxins are neutral, MEKC was used in combination with FLD. The developed CZE-UV and CZE-C(4) D methods provide better resolution, selectivity, and separation efficiency compared to CZE-MS and MEKC-FLD. The sensitivity of the CZE-C(4) D and MEKC-FLD methods was superior to UV and MS, with LOD values ranging from 140 to 715 ng/mL for CZE-C(4) D and 60.9 to 104 ng/mL for MEKC-FLD. With the regulatory limit for shellfish samples of 800 ng/mL, the CZE-C(4) D and MEKC-FLD methods were evaluated for the screening and detection of PSTs in shellfish samples. While the CZE-C(4) D method suffered from significant interferences from the shellfish matrix, MEKC-FLD was successfully used for PST screening of a periodate-oxidized mussel sample, with results confirmed by HPLC-FLD. This confirms the potential of MEKC-FLD for screening of PSTs in shellfish samples.
Biosynthesis and characterization of polyhydroxyalkanoate containing high 3-hydroxyhexanoate monomer fraction from crude palm kernel oil by recombinant Cupriavidus necator

Wong YM, Brigham CJ, Rha C, Sinskey AJ, Sudesh K

Bioresour Technol, 2012 Oct;121:320-7.
PMID: 22858502 DOI: 10.1016/j.biortech.2012.07.015

The potential of plant oils as sole carbon sources for production of P(3HB-co-3HHx) copolymer containing a high 3HHx monomer fraction using the recombinant Cupriavidus necator strain Re2160/pCB113 has been investigated. Various types and concentrations of plant oils were evaluated for efficient conversion of P(3HB-co-3HHx) copolymer. Crude palm kernel oil (CPKO) at a concentration of 2.5 g/L was found to be most suitable for production of copolymer with a 3HHx content of approximately 70 mol%. The time profile of these cells was also examined in order to study the trend of 3HHx monomer incorporation, PHA production and PHA synthase activity. (1)H NMR and (13)C NMR analyses confirmed the presence of P(3HB-co-3HHx) copolymer containing a high 3HHx monomer fraction, in which monomers were not randomly distributed. The results of various characterization analyses revealed that the copolymers containing a high 3HHx monomer fraction demonstrated soft and flexible mechanical properties.
Comparative population structure of Cynopterus fruit bats in peninsular Malaysia and southern Thailand

Campbell P, Schneider CJ, Adnan AM, Zubaid A, Kunz TH

Mol Ecol, 2006 Jan;15(1):29-47.
PMID: 16367828

The extent to which response to environmental change is mediated by species-specific ecology is an important aspect of the population histories of tropical taxa. During the Pleistocene glacial cycles and associated sea level fluctuations, the Sunda region in Southeast Asia experienced concurrent changes in landmass area and the ratio of forest to open habitat, providing an ideal setting to test the expectation that habitat associations played an important role in determining species' response to the opportunity for geographic expansion. We used mitochondrial control region sequences and six microsatellite loci to compare the phylogeographic structure and demographic histories of four broadly sympatric species of Old World fruit bats in the genus, Cynopterus. Two forest-associated species and two open-habitat generalists were sampled along a latitudinal transect in Singapore, peninsular Malaysia, and southern Thailand. Contrary to expectations based on habitat associations, the geographic scale of population structure was not concordant across ecologically similar species. We found evidence for long and relatively stable demographic history in one forest and one open-habitat species, and inferred non-coincident demographic expansions in the second forest and open-habitat species. Thus, while these results indicate that Pleistocene climate change did not have a single effect on population structure across species, a correlation between habitat association and response to environmental change was supported in only two of four species. We conclude that interactions between multiple factors, including historical and contemporary environmental change, species-specific ecology and interspecific interactions, have shaped the recent evolutionary histories of Cynopterus fruit bats in Southeast Asia.

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