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1.
Arch Environ Contam Toxicol ; 86(1): 1-12, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37938326

RESUMEN

Microplastics (MPs) distributions have been increasingly reported in the terrestrial areas worldwide, but little information is available for ASEAN regions. In this study, 68 sediment samples of drainage channels, lakes, rivers and beaches from Myanmar were collected between 2014 and 2018, and analyzed to investigate the status of MPs concentration and prevalence. The high concentrations of MPs in sediments were found in urban cities called Yangon (13,855 pieces/kg dry weight), Mandalay (11,946 pieces/kg), and Pathein (12,583 pieces/kg), which were two orders of magnitude greater than the MPs concentrations in sediments collected in rural towns called Wundwin. These results suggested that the difference in high population densities and high municipal solid waste generation rates are related to the MPs contamination in sediments. Polyethylene, polypropylene and polyethylene terephthalate with fragments, lines/fibers and films/sheets were major polymers and shape in the sediment samples analyzed from Myanmar. To our knowledge, this is the first study to report the distribution of MPs in sediments from Myanmar.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Plásticos , Mianmar , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Sedimentos Geológicos
2.
BMC Oral Health ; 24(1): 31, 2024 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-38184546

RESUMEN

BACKGROUND: This study aimed to examine the impact of dental caries and other potential socio-demographic factors on the oral health-related quality of life (OHRQoL) of preschool children from Myanmar. This was done using the Scale of Oral Health Outcomes for 5-year-old children (SOHO-5) as reported by both the children and their parents. METHODS: A structured questionnaire was conducted to collect demographic information about the children and their caregivers, as well as socioeconomic data. The OHRQoL was assessed by interviewing the children and their parents using the Myanmar versions of SOHO-5c and SOHO-5p, respectively. Caries experience was assessed by two calibrated examiners and recorded using the dmft index. The Poisson regression model was adopted to investigate the association between OHRQoL and dental caries including socioeconomic factors. RESULTS: A total of 454 pairs participated in the study. Among them, 64% of children and 70% of parents reported a negative impact on OHRQoL (with SOHO-5c and SOHO-5p scores exceeding 0). The mean score (SD) of the child self-report and parental version of the SOHO-5 was 1.86 (2.27) and 2.65 (3.13), respectively. Difficulties in eating and sleeping were the most commonly reported by both children and parents. The overall prevalence of dental caries was 87% (mean dmft score:5.59, SD:4.65). The final multivariate-adjusted model revealed that children with higher caries experiences were more likely to have lower OHRQoL for both child self-report (RR 4.38, 95% CI 3.16-6.14, p < 0.001) and parental report (RR 6.07, 95% CI 4.38-8.41, p < 0.001), respectively. A lower family income had a negative impact on the children's OHRQoL in child self-report (RR 1.59, 95% CI 1.26-2.04, p < 0.001) and parental report (RR 1.46, 95% CI 1.19-1.78, p < 0.001). CONCLUSION: Two-thirds of the study children and their parents perceived the negative impact on children's OHRQoL. Higher caries experience and lower family income were associated with poorer OHRQoL of 5-year-old Myanmar children.


Asunto(s)
Caries Dental , Preescolar , Humanos , Autoinforme , Caries Dental/epidemiología , Susceptibilidad a Caries Dentarias , Mianmar/epidemiología , Calidad de Vida
3.
Psychol Med ; 52(7): 1306-1320, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-32914737

RESUMEN

BACKGROUND: Large variations in prevalence rates of common mental disorder (CMD) amongst refugees and forcibly displaced populations have raised questions about the accuracy and value of epidemiological surveys in these cross-cultural settings. We examined the associations of sociodemographic indices, premigration traumatic events (TEs), postmigration living difficulties (PMLDs), and psychosocial disruptions based on the Adaptive Stress Index (ASI) in relation to CMD prevalence amongst the Rohingya, Chin and Kachin refugees originating from Myanmar and relocated to Malaysia. METHODS: Parallel epidemiological studies were conducted in areas where the three groups were concentrated in and around Malaysia (response rates: 80-83%). RESULTS: TE exposure, PMLDs and ASI were significantly associated with CMD prevalence in each group but the Rohingya recorded the highest exposure to all three of these former indices relative to Chin and Kachin (TE: mean = 11.1 v. 8.2 v. 11; PMLD: mean = 13.5 v. 7.4 v. 8.7; ASI: mean = 128.9 v. 32.1 v. 35.5). Multiple logistic regression analyses based on the pooled sample (n = 2058) controlling for gender and age, found that ethnic group membership, premigration TEs (16 or more TEs: OR, 2.00; 95% CI, 1.39-2.88; p < 0.001), PMLDs (10-15 PMLDs: OR, 4.19; 95% CI, 3.17-5.54; 16 or more PMLDs: OR, 7.23; 95% CI, 5.24-9.98; p < 0.001) and ASI score (ASI score 100 or greater: OR, 2.19; 95% CI, 1.46-3.30; p < 0.001) contributed to CMD. CONCLUSIONS: Factors specific to each ethnic group and differences in the quantum of exposure to TEs, PMLDs and psychosocial disruptions appeared to account in large part for differences in prevalence rates of CMDs observed across these three groups.


Asunto(s)
Trastornos Mentales , Refugiados , Trastornos por Estrés Postraumático , Mentón , Humanos , Trastornos Mentales/epidemiología , Mianmar/epidemiología , Prevalencia , Refugiados/psicología , Trastornos por Estrés Postraumático/epidemiología
4.
BMC Oral Health ; 21(1): 2, 2021 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-33388030

RESUMEN

BACKGROUND: Oral diseases are common and widespread around the world. The most common oral diseases are preventable, and early onset is reversible. Myanmar faces many challenges in rendering oral health services, because approximately 70% of the total population resides in rural areas. These relate to the availability and accessibility of oral health services. Therefore, oral health education is one key element to prevent oral diseases and to promote oral health. METHODS: A quasi-experimental study was carried out at Basic Education Middle Schools in rural areas of Magway Township to study the effectiveness of oral health education on the knowledge and behavior of 8- to 10-year-old school children. A total of 220 school children, 110 from intervention schools and 110 from control schools, participated in this study from 2015 to 2017. Data were collected before and after intervention in the two groups by using a self-administered questionnaire. Tooth brushing method data were collected by direct observation with a checklist. Oral health education was provided at eight weekly intervals for 1 year. At one and a half years, third-time data collection was done on the intervention group to assess retention. Chi-square test, two samples t-test and one-way repeated measure ANOVA were used for data analysis. The study was approved by the Institutional Review Board of the University of Public Health in Yangon, Myanmar. RESULTS: There were significant differences between the two groups in four out of five knowledge questions (p < 0.05) and all behavior questions (p < 0.001) after intervention. A positive effect of oral health education for a period of 45 min at eight weekly intervals for 1 year was found in the intervention group. The intervention had a significant effect on the sustainability of the correct knowledge and behavior of the intervention group although the education session was stopped for 6 months (p < 0.001). Their mean knowledge and behavioral scores at three different points in time were (2.45 ± 1.12 and1.56 ± 0.90) at baseline, (3.79 ± 1.12 and 3.60 ± 1.21) at 1 year after education and (4.07 ± 0.98 and 3.24 ± 1.31) at 6 months after cessation of education, respectively. CONCLUSIONS: Repeated oral health education was effective in promoting and sustaining oral health knowledge and behavior.


Asunto(s)
Educación en Salud Dental , Cepillado Dental , Niño , Conductas Relacionadas con la Salud , Conocimientos, Actitudes y Práctica en Salud , Humanos , Mianmar , Salud Bucal , Instituciones Académicas
5.
Proc Biol Sci ; 287(1938): 20202129, 2020 11 11.
Artículo en Inglés | MEDLINE | ID: mdl-33171091

RESUMEN

Since their discovery in 1927, the phylogenetic status of the Myanmar amphipithecines has been highly debated. These fossil primates are recognized either as anthropoids or as adapiform strepsirrhines. This uncertainty was largely the consequence of a limited fossil record consisting mostly of jaw fragments but lacking the critical cranial elements that might resolve this debate. We report here cranial remains associated with an ulna from a single individual pertaining to the amphipithecine Ganlea megacanina. In addition to anthropoid-like dentognathic characters, Ganlea displays several ulna and skull features that testify to its anthropoid affinities (e.g. short subvertically oriented lacrimal duct, lacrimal foramen and bone inside the orbit, maxillary contribution to the lower orbital rim, fused metopic suture). By contrast to crown anthropoids, however, Ganlea lacks postorbital closure, confirming that postorbital closure appeared later than many anthropoid dentognathic characters and evolved convergently in extant tarsiers and anthropoids. Thus, amphipithecines must now be recognized as stem anthropoids offering a unique window on the early evolution of cranial and skeletal features in anthropoids, and reinforcing the hypothesis of an origin and early diversification of anthropoids in Asia.


Asunto(s)
Evolución Biológica , Haplorrinos , Animales , Asia , Fósiles , Mianmar , Órbita , Filogenia , Primates , Cráneo
6.
Nature ; 513(7519): 501-6, 2014 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-25219854

RESUMEN

The strong present-day Asian monsoons are thought to have originated between 25 and 22 million years (Myr) ago, driven by Tibetan-Himalayan uplift. However, the existence of older Asian monsoons and their response to enhanced greenhouse conditions such as those in the Eocene period (55-34 Myr ago) are unknown because of the paucity of well-dated records. Here we show late Eocene climate records revealing marked monsoon-like patterns in rainfall and wind south and north of the Tibetan-Himalayan orogen. This is indicated by low oxygen isotope values with strong seasonality in gastropod shells and mammal teeth from Myanmar, and by aeolian dust deposition in northwest China. Our climate simulations support modern-like Eocene monsoonal rainfall and show that a reinforced hydrological cycle responding to enhanced greenhouse conditions counterbalanced the negative effect of lower Tibetan relief on precipitation. These strong monsoons later weakened with the global shift to icehouse conditions 34 Myr ago.


Asunto(s)
Clima , Efecto Invernadero/historia , Lluvia , Altitud , Exoesqueleto/química , Animales , China , Clima Desértico , Polvo/análisis , Fósiles , Gastrópodos/química , Historia Antigua , Mianmar , Isótopos de Oxígeno , Estaciones del Año , Temperatura , Tibet , Diente/química
7.
Eur J Cancer Care (Engl) ; 29(2): e13207, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31820851

RESUMEN

INTRODUCTION: Oral cancer is common cancer in many low- and middle-income countries (LMICs) with a low five-year survival rate. It is among the four most common types of cancer in South East Asia region. In South-Central Asia, lip and oral cavity cancer is the second most common cancer according to the specific cancer types. METHODS: This scoping review intended to investigate published studies on the current prevalence and incidence of oral cancer in LMICs. The review was conducted applying the search words "Oral Cancer" and "Mouth neoplasm" as the Medical Subject Heading (MeSH) major topic and "Epidemiology" and ("prevalence" OR "incidence") as the MeSH subheading; the search was supplemented by cross-references. Included studies met the following criteria: original studies, reporting of prevalence or incidence rates, population-based studies, studies in English language and studies involving humans. RESULTS: The sample sizes ranged from 486 to 101,761 with 213,572 persons included. Buccal mucosa is one of the most common sites of oral cancer, associated with the widespread exposure to chewing tobacco. The incidence is likely to rise in the region where gutkha, pan masala, pan-tobacco and various other forms of chewing tobacco are popular. CONCLUSION: This review contributes to useful information on prevalence and incidence estimates of oral cancer in LMICs.


Asunto(s)
Países en Desarrollo , Neoplasias de la Boca/epidemiología , Uso de Tabaco/epidemiología , Tabaco sin Humo , Consumo de Bebidas Alcohólicas/epidemiología , Areca , Cambodia/epidemiología , Neoplasias Gingivales/epidemiología , Humanos , Incidencia , India/epidemiología , Neoplasias de los Labios/epidemiología , Malasia/epidemiología , Mucosa Bucal , Mianmar/epidemiología , Neoplasias Palatinas/epidemiología , Prevalencia , Factores de Riesgo , Fumar/epidemiología , Sri Lanka/epidemiología , Neoplasias de la Lengua/epidemiología
8.
BMC Oral Health ; 20(1): 322, 2020 11 11.
Artículo en Inglés | MEDLINE | ID: mdl-33176779

RESUMEN

BACKGROUND: Utilization of oral health services has been low among rural populations in Thailand, especially for minority ethnicity populations living along the borders. The aim of this study was to increase understanding of the determinants of the underutilization of oral health services among these populations. METHODS: A qualitative study using in-depth interview and semi-structured interview was conducted among participants of Karen ethnicity living in Mae Tan Sub-district, Thasongyang District, Tak Province, Thailand. The interviews focused on exploring the participants' perceptions of oral health problems, oral health and hygiene, and oral health-seeking behaviors. The verbatim-transcribed interviews were analyzed using thematic analysis. RESULTS: A total of 101 participants (50 adults and 51 children) with a Karen ethnic background took part in the interviews. Most participants could not identify oral health problems and did not perceive dental disease as a problem unless there was severe pain that could not be relieved by painkillers. The Karen ethnic community worked as subsistence farmers, and their busy daily activities consisted of farming, going to the forest to hunt and gather, performing housework, and taking care of their children. Dental health was given a lower priority compared with general health. The perceived value of primary teeth was low, which was identified as an underlying factor resulting in delayed oral health care seeking among this population. The participants had relied on self-care throughout their lifetimes, using either traditional medicines or modern painkillers to relieve toothaches. Fear of dental procedures among children was also described as a barrier to seeking dental health care. CONCLUSIONS: This study found that the lifestyle and traditions of Karen people living in this area influence their oral health care and hygiene activities as well as their health-seeking behaviors. Further research should emphasize how to improve oral health promotion by providing necessary services and health education appropriately to Karen ethnic populations living along the Thai-Myanmar border.


Asunto(s)
Etnicidad , Salud Bucal , Adulto , Niño , Humanos , Mianmar , Percepción , Tailandia
9.
BMC Evol Biol ; 19(1): 193, 2019 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-31638893

RESUMEN

BACKGROUND: The existence of extended post-reproductive lifespan is an evolutionary puzzle, and its taxonomic prevalence is debated. One way of measuring post-reproductive life is with post-reproductive representation, the proportion of adult years lived by females after cessation of reproduction. Analyses of post-reproductive representation in mammals have claimed that only humans and some toothed whale species exhibit extended post-reproductive life, but there are suggestions of a post-reproductive stage for false killer whales and Asian elephants. Here, we investigate the presence of post-reproductive lifespan in Asian elephants using an extended demographic dataset collected from semi-captive timber elephants in Myanmar. Furthermore, we investigate the sensitivity of post-reproductive representation values to availability of long-term data over 50 years. RESULTS: We find support for the presence of an extended post-reproductive stage in Asian elephants, and that post-reproductive representation and its underlying demographic rates depend on the length of study period in a long-lived animal. CONCLUSIONS: The extended post-reproductive lifespan is unlikely due to physiological reproductive cessation, and may instead be driven by mating preferences or condition-dependent fertility. Our results also show that it is crucial to revisit such population measures in long-lived species as more data is collected, and if the typical lifespan of the species exceeds the initial study period.


Asunto(s)
Elefantes/fisiología , Longevidad/fisiología , Reproducción/fisiología , Animales , Femenino , Masculino , Mianmar , Factores de Tiempo
10.
BMC Public Health ; 19(1): 63, 2019 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-30642303

RESUMEN

BACKGROUND: In Myanmar, HIV is concentrated among key populations, yet less than half of the estimated 250,000 men who have sex with men (MSM) and transgender women (TW) report recent HIV testing. As many as 50% of MSM and TW may conceal their same-sex preferences and behaviors, yet little is known about the barriers faced by those who are locally regarded as 'hidden' - that is, MSM who do not disclose same-sex preferences and/or identify as gay. This study explored specific barriers to accessing HIV testing and other prevention services among 'hidden' MSM to inform appropriate models of service delivery. METHODS: In-depth interviews with MSM (n = 12) and TW (n = 13) and focus group discussions (FGD) with MSM and TW community members, leaders and key informants (n = 35) were undertaken in Yangon during June - September 2015. Participants were recruited by word-of-mouth by trained peer data collectors. Responses to questions from semi-structured guides were transcribed and coded using Atlas Ti. Codes were based on key domains in the guides and applied to transcripts to identify and analyze emerging themes. RESULTS: Fear of stigma and discrimination and the need to meet gender expectations were key reasons for non-disclosure of same-sex preferences and behaviors; this typically manifested as avoidance of other MSM and settings in which sexual identity might be implicated. These concerns influenced preference and interaction with HIV services, with many avoiding MSM-specific services or eschewing HIV testing services entirely. The difficulties of engaging hidden MSM in HIV prevention was strongly corroborated by service providers. CONCLUSION: Hidden MSM face multiple barriers to HIV testing and prevention. Strategies cognizant of concerns for anonymity and privacy, such as One-Stop Shop services and online-based health promotion, can discretely provide services appropriate for hidden MSM. Enhanced capacity of peer-service providers and mainstream health staff to identify and respond to the psychosocial challenges reported by hidden MSM in this study may further encourage service engagement. Overarching strategies to strengthen the enabling environment, such as legal reform and LGBTI community mobilisation, can lessen stigma and discrimination and increase hidden MSM's comfort and willingness to discuss same-sex behavior and access appropriate services.


Asunto(s)
Miedo , Infecciones por VIH/prevención & control , Accesibilidad a los Servicios de Salud , Homosexualidad Masculina , Aceptación de la Atención de Salud , Conducta Sexual , Minorías Sexuales y de Género , Adolescente , Adulto , Recolección de Datos , Revelación , Femenino , Grupos Focales , VIH , Infecciones por VIH/diagnóstico , Homosexualidad Masculina/psicología , Humanos , Masculino , Mianmar , Privacidad , Minorías Sexuales y de Género/psicología , Discriminación Social , Estigma Social , Personas Transgénero , Adulto Joven
11.
Malar J ; 16(1): 92, 2017 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-28241830

RESUMEN

BACKGROUND: Insecticide-treated clothing (ITC) has long been used for military and outdoor recreational purposes and there is substantial evidence to show that it can protect against arthropod biting. As a complementary vector control measure, ITC could be used to address outdoor transmission of malaria, particularly among mobile and migrant populations and night-time workers such as rubber tappers, who may be beyond the reach of core interventions. However, more information is required on acceptability and preferences of target groups towards ITC to understand whether it could be a viable strategy in Myanmar. METHODS: A cluster-randomized, double-blind, non-inferiority crossover trial was performed to determine acceptability of ITC versus identical, untreated clothing (NTC) among migrant rubber tappers. The study took place between January and May 2015 with 234 participants in 16 clusters in Thanbyuzayat Township, Mon State, Myanmar. Participants were randomly assigned to the order of clothing distribution and followed up at 2, 4 and 6 week intervals. Acceptability was assessed through structured questionnaires, focus group discussions and in-depth interviews. A cluster-level non-inferiority analysis was conducted using STATA, while qualitative data were digitally recorded, transcribed and content-analysed to identify patterns and themes, and managed thematically in Excel 2010®. RESULTS: Acceptability of both types of clothing was high. ITC was deduced to be non-inferior to NTC for seven out of eight indicators regarding perceptions (looks nice, is durable, is pleasant to wear for nighttime work, reduces mosquito bites, would recommend the clothing, would buy the clothing, like the clothing overall). A high proportion of respondents reported that the clothing reduced mosquito bites (ITC-98%; NTC-94%). Clothing was worn regularly (about 11 times in the previous two weeks). The most common reasons for not wearing the clothing every night were that it was being washed or dried, or the participant did not go to work. CONCLUSIONS: The high level of acceptability suggests that ITC could be an appropriate strategy for personal protection amongst migrant rubber tappers in outdoor transmission settings in Myanmar. However, more research is needed into the feasibility and protective efficacy of ITC before it can be considered for wider roll-out. Trial registration Clinical trials ACTRN12615000432516.


Asunto(s)
Vestuario/psicología , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Insecticidas , Malaria/prevención & control , Control de Mosquitos , Enfermedades Profesionales/prevención & control , Migrantes/estadística & datos numéricos , Adulto , Análisis por Conglomerados , Estudios Cruzados , Método Doble Ciego , Industria Procesadora y de Extracción , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mianmar , Ropa de Protección/estadística & datos numéricos , Goma , Adulto Joven
12.
Reprod Health Matters ; 25(51): 58-68, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29210341

RESUMEN

For displaced and migrant women in northern Thailand, access to health care is often limited, unwanted pregnancy is common, and unsafe abortion is a major contributor to maternal death and disability. Based on a pilot project and situational analysis research, in 2015 a multinational team introduced the Safe Abortion Referral Programme (SARP) in Chiang Mai, Thailand, to reduce the socio-linguistic, economic, documentation, and transportation barriers women from Burma face in accessing safe and legal abortion care in Thailand. Our qualitative study documented the experiences of women with unwanted pregnancies who accessed the SARP in order to inform programme improvement and expansion. We conducted 22 in-depth, in-person interviews and analysed them for content and themes using deductive and inductive techniques. Women were overwhelmingly positive about their experiences using the SARP. They reported lack of costs, friendly programme staff, accompaniment to and interpretation at the providing facility, and safety of services as key features. Financial and legal circumstances shaped access to the programme and women learned about the SARP through word-of-mouth and community workshops. After accessing the SARP and receiving support, women became community advocates for reproductive health. Efforts to expand the programme and raise awareness in migrant communities appear warranted. Our findings suggest that referral programmes for safe and legal abortion can be successful in settings with large displaced and migrant populations. Identifying ways to work within legal constraints to expand access to safe services has the potential to reduce harm from unsafe abortion even in humanitarian settings.


Asunto(s)
Aborto Inducido/psicología , Accesibilidad a los Servicios de Salud/organización & administración , Embarazo no Deseado/psicología , Servicios de Salud Reproductiva/organización & administración , Migrantes , Aborto Inducido/economía , Adolescente , Adulto , Femenino , Accesibilidad a los Servicios de Salud/economía , Humanos , Agencias Internacionales , Entrevistas como Asunto , Mianmar , Proyectos Piloto , Política , Embarazo , Investigación Cualitativa , Derivación y Consulta/organización & administración , Sistemas de Socorro/organización & administración , Servicios de Salud Reproductiva/economía , Servicios de Salud Reproductiva/provisión & distribución , Factores Socioeconómicos , Tailandia , Salud de la Mujer , Adulto Joven
13.
Naturwissenschaften ; 103(1-2): 11, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26820298

RESUMEN

A unique specimen of the fossil harvestman Halitherses grimaldii Giribet and Dunlop, 2005 (Arachnida: Opiliones) from the Cretaceous (ca. 99 Ma) Burmese amber of Myanmar reveals a fully extended penis. This is the first record of a male copulatory organ of this nature preserved in amber and is of special importance due to the age of the deposit. The penis has a slender, distally flattened truncus, a spatulate heart-shaped glans and a short distal stylus, twisted at the tip. In living harvestmen, the penis yields crucial characters for their systematics. Male genital morphology in H. grimaldii appears to be unique among the wider Dyspnoi clade to which this fossil belongs. The large eyes in the fossil differ markedly from other members of the subfamily Ortholasmatinae to which H. grimaldii was originally referred. Based on recent data, it has been argued that large eyes may be plesiomorphic for Palpatores (i.e. the suborders Eupnoi and Dyspnoi), potentially rendering this character plesiomorphic for the fossil too. Thus, the unique structure of the penis seen here, and the probable lack of diaphanous teeth, present in all other extant non-acropsopilionid Dyspnoi, suggest that H. grimaldii represents a new, extinct family of large-eyed dyspnoid harvestmen, Halithersidae fam. nov.; a higher taxon in amber diagnosed here on both somatic and genital characters.


Asunto(s)
Arácnidos/anatomía & histología , Arácnidos/clasificación , Fósiles , Ámbar , Animales , Masculino , Mianmar , Pene/anatomía & histología , Especificidad de la Especie
14.
J Hum Evol ; 84: 1-15, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25978976

RESUMEN

Here we report two kinds of colobine fossils discovered from the latest Miocene/Early Pliocene Irrawaddy sediments of the Chaingzauk area, central Myanmar. A left mandibular corpus fragment preserving M1-3 is named as a new genus and species, Myanmarcolobus yawensis. Isolated upper (M(1)?) and lower (M2) molars are tentatively identified as Colobinae gen. et sp. indet. Although both forms are medium-sized colobines, they are quite different from each other in M2 morphology. The isolated teeth of the latter show typical colobine-type features, so it is difficult to identify their taxonomic position, whereas lower molars of Myanmarcolobus have unique features, such as a trapezoid-shaped long median lingual notch, a deeply concave median buccal cleft, a strongly developed mesiobuccal notch, and rather obliquely running transverse lophids. Compared with fossil and living Eurasian colobine genera, Myanmarcolobus is most similar in lower molar morphology to the Pliocene Dolichopithecus of Europe rather than to any Asian forms. In Dolichopithecus, however, the tooth size is much larger and the median lingual notch is mesiodistally much shorter than that of Myanmarcolobus. The discovery of Myanmarcolobus in central Myanmar is the oldest fossil record in Southeast Asia not only of colobine but also of cercopithecid monkeys and raises many questions regarding the evolutionary history of Asian colobine monkeys.


Asunto(s)
Colobinae/anatomía & histología , Colobinae/clasificación , Fósiles/anatomía & histología , Animales , Evolución Biológica , Mandíbula/anatomía & histología , Maxilar/anatomía & histología , Diente Molar/anatomía & histología , Mianmar
15.
Proc Natl Acad Sci U S A ; 109(26): 10293-7, 2012 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-22665790

RESUMEN

Reconstructing the origin and early evolutionary history of anthropoid primates (monkeys, apes, and humans) is a current focus of paleoprimatology. Although earlier hypotheses frequently supported an African origin for anthropoids, recent discoveries of older and phylogenetically more basal fossils in China and Myanmar indicate that the group originated in Asia. Given the Oligocene-Recent history of African anthropoids, the colonization of Africa by early anthropoids hailing from Asia was a decisive event in primate evolution. However, the fossil record has so far failed to constrain the nature and timing of this pivotal event. Here we describe a fossil primate from the late middle Eocene Pondaung Formation of Myanmar, Afrasia djijidae gen. et sp. nov., that is remarkably similar to, yet dentally more primitive than, the roughly contemporaneous North African anthropoid Afrotarsius. Phylogenetic analysis suggests that Afrasia and Afrotarsius are sister taxa within a basal anthropoid clade designated as the infraorder Eosimiiformes. Current knowledge of eosimiiform relationships and their distribution through space and time suggests that members of this clade dispersed from Asia to Africa sometime during the middle Eocene, shortly before their first appearance in the African fossil record. Crown anthropoids and their nearest fossil relatives do not appear to be specially related to Afrotarsius, suggesting one or more additional episodes of dispersal from Asia to Africa. Hystricognathous rodents, anthracotheres, and possibly other Asian mammal groups seem to have colonized Africa at roughly the same time or shortly after anthropoids gained their first toehold there.


Asunto(s)
Hominidae , Primates , África , Animales , Hominidae/clasificación , Mianmar , Filogenia , Primates/clasificación
16.
Zootaxa ; 3786: 85-90, 2014 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-24869526

RESUMEN

Foveocrotaphus gen. nov. and new species F. burmanicus from Myanmar is described. The new genus is similar to Physocrotaphus Parry, with respect to shape and structure of ligula and paraglossae. The two genera can be diagnosed easily by median tooth of mentum, bifid in Physocrotaphus, i.e. Foveocrotaphus gen. n. has simple, narrow and pointed. Is distinguishable from all other known Physocrotaphini genera by narrower pronotum, very stout ligula combined with long and simple median tooth of mentum and by male sternites 2 and 3 with one big shared median depression.


Asunto(s)
Escarabajos/clasificación , Estructuras Animales/anatomía & histología , Animales , Escarabajos/anatomía & histología , Masculino , Mianmar
17.
Proc Biol Sci ; 280(1763): 20130665, 2013 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-23740779

RESUMEN

Mammals dominate modern terrestrial herbivore ecosystems, whereas extant herbivorous reptiles are limited in diversity and body size. The evolution of reptile herbivory and its relationship to mammalian diversification is poorly understood with respect to climate and the roles of predation pressure and competition for food resources. Here, we describe a giant fossil acrodontan lizard recovered with a diverse mammal assemblage from the late middle Eocene Pondaung Formation of Myanmar, which provides a historical test of factors controlling body size in herbivorous squamates. We infer a predominately herbivorous feeding ecology for the new acrodontan based on dental anatomy, phylogenetic relationships and body size. Ranking body masses for Pondaung Formation vertebrates indicates that the lizard occupied a size niche among the larger herbivores and was larger than most carnivorous mammals. Paleotemperature estimates of Pondaung Formation environments based on the body size of the new lizard are approximately 2-5°C higher than modern. These results indicate that competitive exclusion and predation by mammals did not restrict body size evolution in these herbivorous squamates, and elevated temperatures relative to modern climates during the Paleogene greenhouse may have resulted in the evolution of gigantism through elevated poikilothermic metabolic rates and in response to increases in floral productivity.


Asunto(s)
Ecosistema , Fósiles , Lagartos , Animales , Evolución Biológica , Tamaño Corporal/genética , Efecto Invernadero , Herbivoria , Lagartos/genética , Lagartos/fisiología , Mamíferos/genética , Mamíferos/fisiología , Mianmar , Filogenia
18.
J Hum Evol ; 65(2): 143-55, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23823753

RESUMEN

The extinct Southeast Asian primate family Amphipithecidae is regularly cited in discussions of anthropoid origins, but its phylogenetic position remains controversial. In part, the lack of consensus regarding amphipithecid relationships can be attributed to uncertainty regarding the homology of upper molar structures in this group. Here, we describe a virtually pristine upper molar of Pondaungia cotteri from the late middle Eocene Pondaung Formation of Myanmar, which is the first example of a relatively unworn and well-preserved amphipithecid upper molar ever recovered. The distolingual upper molar cusp in this new specimen of Pondaungia appears to be a lingually displaced and enlarged metaconule, rather than a hypocone or pseudohypocone as previous workers have thought. Reassessment of the upper molar morphology of other amphipithecids and putative amphipithecids reveals a very similar pattern in Siamopithecus, Myanmarpithecus and Ganlea, all of which are interpreted as having upper molars showing many of the same derived features apparent in Pondaungia. In contrast, the upper molar morphology of Bugtipithecus diverges radically from that of undoubted amphipithecids, and the latter taxon is excluded from Amphipithecidae on this basis. Phylogenetic analyses of several character-taxon matrices culled from the recent literature and updated to reflect the new information on amphipithecid upper molar morphology yield similar results. Consensus tree topologies derived from these analyses support amphipithecid monophyly and stable relationships within Amphipithecidae. Amphipithecids appear to be stem members of the anthropoid clade.


Asunto(s)
Evolución Biológica , Fósiles , Haplorrinos/anatomía & histología , Haplorrinos/clasificación , Diente Molar/anatomía & histología , Animales , Mianmar , Filogenia
19.
Southeast Asian J Trop Med Public Health ; 44(6): 1108-14, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24450249

RESUMEN

We conducted a cross sectional study among children aged 12-13 years in Yongon, Myanmar to assess the oral health status and oral hygiene habits. The studied 220 students were from two high schools, one urban and the other rural. We conducted an oral health examination following WHO criteria and used a self-administrated questionnaire. The prevalence rate of dental caries among the study population was 53.2%. The mean number of decayed, missing and filled teeth (DMFT) was 1.7 +/- 2.1 teeth per person (decayed, 1.5 +/- 1.9); missing 0.0 +/- 0.2; filled, 0.1 +/- 0.4). Multivariate analysis revealed significant risk factors for dental caries were: the geographical location of the school (adjusted OR=2.24; 95% CI: 1.01-4.94), occupational status of the father (adjusted OR=2.83; 95% CI: 1.05-7.62) and the child's attitude about dental caries (adjusted OR=2.35; 95% CI: 1.18-4.67). Knowledge and oral hygiene habits were not associated with dental caries. The results of this study suggest the need to change from restoration orientated dentistry to dental public health care services, to reduce of the high level of dental caries in this age group.


Asunto(s)
Salud Bucal/estadística & datos numéricos , Higiene Bucal/estadística & datos numéricos , Adolescente , Niño , Estudios Transversales , Caries Dental/epidemiología , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Mianmar/epidemiología , Prevalencia , Factores de Riesgo , Factores Socioeconómicos
20.
Zootaxa ; 3681: 405-12, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-25232618

RESUMEN

A new genus of ants, Zigrasimecia Barden and Grimaldi, is described for a new and uniquely specialized species, Z. tonsora Barden and Grimaldi n.sp., preserved in Cretaceous amber from Myanmar. The amber is radiometrically dated at 99 myo. Zigrasimecia is closely related to another basal genus of ants known only in Burmese and French Cretaceous amber, Sphecomyrmodes Engel and Grimaldi, based in part on the shared possession of a comb of pegs on the clypeal margin, as well as mandible structure. Highly specialized features of Zigrasimecia include extensive development of the clypeal comb, a thick brush of setae on the oral surface of the mandibles and on the labrum, and a head that is broad, flattened, and which bears a crown of blackened, rugose cuticle. Mouthparts are hypothesized to have functioned in a unique manner, showing no clear signs of dentition representative of "chewing" or otherwise processing solid food. Although all ants in Burmese amber are basal, stem-group taxa, there is an unexpected diversity of mouthpart morphologies and probable feeding modes.


Asunto(s)
Ámbar/química , Hormigas/clasificación , Estructuras Animales/anatomía & histología , Animales , Hormigas/anatomía & histología , Femenino , Fósiles , Mianmar
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