Profiling of faecal water and urine metabolites among Papua New Guinea highlanders believed to be adapted to low protein intake

Introduction

Adequate amount of proteins from foods are normally needed to maintain muscle mass of the human body. Although protein intakes of Papua New Guinea (PNG) highlanders are less than biologically adequate, protein deficiency related disorders have rarely been reported. It has been postulated that gut microbiota play a role in such low-protein-adaptation.

Objective

To explore underlying biological mechanisms of low-protein adaptation among PNG highlanders by investigating metabolomic profiles of faecal water and urine.

Methods

We performed metabolome analysis using faecal water extracted from faecal samples of PNG highlanders, PNG non-highlanders and Japanese subjects. We paid special attention to amino acids and other metabolites produced by gut microbiota, as well as to metabolites involved in nitrogen recycling in the human gut.

Results

Our results indicated that amino acid levels were higher in faecal water from PNG highlanders than PNG non-highlanders, but amino acid levels did not differ between PNG highlanders and Japanese subjects. Among PNG highlander samples, amino acid levels tended to be higher in those who consumed less protein.

Conclusion

We speculated that a greater proportion of urea was excreted to the intestine among the PNG highlanders than other groups, and that the urea was used for nitrogen salvage. Intestinal bacteria are essential for producing ammonia from urea and also for producing amino acids from ammonia, which is a key process in low-protein adaptation. Profiling the gut microbiota of PNG highlanders is an important avenue for further research into the mechanisms of low-protein adaptation.

     

Immunogenetic studies of two recently contacted populations from Papua New Guinea

We have examined the HLA profiles of the Hagahai and the Haruai people, two linguistic groups in the remote western Schrader mountains who have only recently had administrative contact, and compared them with those of other populations in Papua New Guinea. None of the antigens detected in the two groups was found missing in other populations although significant differences in allele frequencies exist. Recent contact history does not appear to have played any significant role in shaping these differences. Similarly, no evidence of differential selection pressures contributing to HLA heterogeneity was found. The genetic profiles of the Hagahai and the Haruai appear to be a result of recent admixture between unrelated, genetically disparate groups.     

Notes on the Sociology of Wantoks in Papua New Guinea

In Melanesian pidgin languages, wantok means someone with a similar origin as oneself, and connotes a familiarity and mutual solidarity. Wantok has also become a watchword of politics and elite discourse on the Pacific Islands' political and social development, where it is a figure of corruption, clientelism, and the lingering influence of tribal identity. Even among grassroots people, wantok sociality is common, especially in urban places, but wantok talk tends to paint the wantok as a drain and burden. In this paper, I argue that when people perform wantok status they juxtapose village and town as inversions. They thereby create familiar relationships in uncertain situations, but also posit intimacy as inimical to the idea of modernity as embodied in towns. This suggests that the wantok idiom draws upon a particularly segmentary logic of relatedness in which solidarity is relative to difference of varying scales. In so doing, wantoks transform the nature of the kinship ties which inform them. As evidence, I examine debates over urbanisation in Papua New Guinea (PNG), and ethnographic observations of a rural-urban nexus of Normanby Island and Alotau in Milne Bay Province, PNG.     

Research partnerships with local communities: two case studies from Papua New Guinea and Australia

Partnerships between scientists and local communities can increase research capacity and data delivery while improving management effectiveness through enhanced community participation. To encourage such collaboration, this study demonstrates how these partnerships can be formed, drawing on two case studies in coral reef ecosystems in very different social settings (Papua New Guinea and Australia). In each case, steps towards successfully engaging communities in research were similar. These included: (1) early engagement by collaborating organizations to build trust, (2) ensuring scientific questions have direct relevance to the community, (3) providing appropriate incentives for participation, and (4) clear and open communication. Community participants engaged in a variety of research activities, including locating and capturing fishes, collecting and recording data (weight, length and sex), applying external tags, and removing otoliths (ear bones) for ageing and elemental analysis. Research partnerships with communities enhanced research capacity, reduced costs and, perhaps more importantly, improved the likelihood of long-term community support for marine protected areas (MPAs).     

Mosquito host-feeding patterns and implications for Japanese encephalitis virus transmission in northern Australia and Papua New Guinea

Japanese encephalitis (JE) virus spread to northern Australia during the 1990s, transmitted by Culex annulirostris Skuse and other mosquitoes (Diptera: Culicidae). To determine the relative importance of various hosts for potential vectors of JE virus, we investigated the host-feeding patterns of mosquitoes in northern Australia and Western Province of Papua New Guinea, with particular attention to pigs, Sus scrofa L. - the main amplifying host of JE virus in South-east Asia. Mosquitoes were collected by CDC light traps baited with dry ice and 1-octen-3-ol, run 16.00-08.00 hours, mostly set away from human habitations, if possible in places frequented by feral pigs. Bloodmeals of 2569 mosquitoes, representing 15 species, were identified by gel diffusion assay. All species had fed mostly on mammals: only <10% of bloodmeals were from birds. The predominant species was Cx. annulirostris (88%), with relatively few (4.4%) bloodmeals obtained from humans. From all 12 locations sampled, the mean proportion of Cx. annulirostris fed on pigs (9.1%) was considerably lower than fed on other animals (90.9%). Highest rates of pig-fed mosquitoes (>30%) were trapped where domestic pigs were kept close to human habitation. From seven of eight locations on the Australian mainland, the majority of Cx. annulirostris had obtained their bloodmeals from marsupials, probably the Agile wallaby Macropus agilis (Gould). Overall proportions of mosquito bloodmeals identified as marsupial were 60% from the Gulf Plains region of Australia, 78% from the Cape York Peninsula and 64% from the Daru area of Papua New Guinea. Thus, despite the abundance of feral pigs in northern Australia, our findings suggest that marsupials divert host-seeking Cx. annulirostris away from pigs. As marsupials are poor JE virus hosts, the prevalence of marsupials may impede the establishment of JE virus in Australia.     

Litter production and seasonality of mangroves in Papua New Guinea

Productivity, as measured by litter trapping, of a mangrove dominated by Rhizophora stylosa Griff. at Motupore Island (lat. 9° 31′34′?S; long. 147° 17$\text{\$}\text{?}$02‘ E) was 1430 g dry weight m^?2 year^?1. This is a high figure when compared with other studied mangrove sites. Phenological data were obtained for R. stylosa, R. apiculata Blume and Sonneratia alba Smith. All species have a major leaf fall in the wet season. Flowering in both Rhizophora species is greatest during the wet season, but S. alba peaks during the dry season. Leaf emergence data were only available for R. stylosa and these appeared to be trimodal. Correlations were calculated for each component with rainfall, wind run, maximum temperature and minimum temperature. Some significant correlations were obtained with rainfall and maximum temperature. These correlations are discussed and it is suggested that the seasonality of mangrove phenologies needs to be considered in terms of whole tree physiology rather than isolated environmental factors.     

Population variables and life-history characteristics of the alligator pipefish Syngnathoides biaculeatus, in Papua New Guinea

Population structure and life-history variables of the widely distributed alligator pipefish Syngnathoides biaculeatus were characterized in Bootless Bay, Papua New Guinea over the course of 11 months. There was little evidence of seasonality with four focal populations showing no significant change in abundance. Similarly, the sex ratio remained 1:1 for all but 1 month. Reproductive males carrying eggs (148–278 mm in total length, L _T) were found in all months. Brood size was significantly, positively related to male L _T for newly laid broods only. Maximum observed brood size was 351 and mean ± s . d . brood size was 238 ± 57 for newly laid broods. Juveniles and males showed no change in mean L _T over the year while slightly smaller females were captured in November 2006 and September 2007. Males were significantly longer than females so von Bertalanffy growth coefficients were estimated separately for each sex: males L _∞= 285 mm, K = 0·82 year⁻¹ and females L _∞= 261 mm, K = 1·10 year⁻¹. These estimates suggest that this species grows rapidly and has a short-life span. In the context of growing concern about overexploitation of syngnathids, a rapid growth rate combined with year round reproductive activity suggests that the tropical S. biaculeatus may be relatively resilient with regard to fishing pressure.     

Genetic characterization of Gainj- and Kalam-speaking peoples of Papua New Guinea

The research presented focuses on genetic variation in the Gainj- and Kalam-speaking peoples of highland Papua New Guinea. The primary data are typings at 51 genetic loci observed on 600 individuals who reside in 21 census units, called parishes. These data are augmented by cultural and demographic information that has also been collected. Parish sizes are small, ranging from 20 to about 200 individuals. Direct Western contact with these people has been occurring only for the past three decades. Although Westernization is currently increasing, we find that much of the traditional settlement pattern and mate exchange system is preserved. There are segregating variants at 27 loci. Four rare variants are initially described: NP 4-Kalam, ADA 6-Kalam, PEPA 3-Kalam, and FUM 2-Kalam. We find evidence for a new Gm haplotype, a;-, that is recessive to all other Gm haplotypes. It occurs at a high enough frequency, f(a;-) = 0.119, to be considered a "private polymorphism." Average per locus heterozygosity is estimated to be 0.053. This value is not statistically different from levels observed on two modern urban populations. Thus, there is no evidence for a reduced level of genetic variation in these people, despite small parish sizes and a relatively unacculturated social structure.     

Keratinolytic and keratinophilic fungi in the soils of Papua New Guinea

A study was made of soil samples collected during an expedition to the Highlands of Papua New Guinea. Fungi were isolated from the samples by the method of hair baiting (To-Ka-Va). Of the 33 species isolated, about half showed keratinolytic activity. Such activity is previously unreported for Mucor hiemalis f. hiemalis, Myrothecium roridum, Paecilomyces carneus, P. marquandii, Penicillium brevicompactum, Rhinocladiella mansonii and Verticillium lecanii. The species most active keratinolytically were Chrysosporium an. Arthroderma cuniculi, C. an. A. curreyi, C. indicum, Myceliophthora vellerea and Trichophyton ajelloi. The spectrum of fungi with keratinolytic activity isolated from the different sites differed considerably according to the frequency of use by man, heaviest use being correlated with greatest activity. The pH of the soil (varying from 5.8–7.5) had little influence on the type of such fungi isolated.     

Effect of forest fragmentation on bird species richness in Papua New Guinea

Tropical forests worldwide are being fragmented at a rapid rate, causing a tremendous loss of biodiversity. Determining the impacts of forest disturbance and fragmentation on tropical biotas is therefore a central goal of conservation biology. We focused on bird communities in the interior (>100 m from forest edge) of forest fragments (300, 600, and 1200 ha) in the lowlands of Papua New Guinea and compared them with those in continuous forest. We surveyed bird communities using point counts, mist‐netting, and random walks, and measured habitat and microclimate characteristics at each site. We also surveyed leaf‐dwelling arthropods, butterflies, and ants, and obtained diet samples from birds to examine food availability and food preferences. We recorded significantly fewer bird species per point in the 300‐ha forest fragment than in other study sites. Overall, we recorded 80, 84, and 88 species, respectively, in forest fragments, and 102 in continuous forest. Frugivores (especially large frugivores) and insectivores had lower species richness in forest fragments than continuous forest. Our results did not support the food scarcity hypothesis, that is, the decline of insectivorous birds in forest fragments is caused by an impoverished invertebrate prey base. We also found no significant differences among forest fragments and continuous forest in microclimates of forest interiors. Rather, we found that microhabitats preferred by sensitive birds (i.e., 30% of species with the strongest preferences for continuous forest) were less common in forest fragments (19%–31% of points) than in continuous forest (86% of points). Our results suggest that changes in microhabitats may make forest fragments unsuitable for sensitive species. However, limited dispersal capabilities could also make some species of birds less likely to disperse and occupy fragments. In addition, impoverished food resources, size of the forest fragment, or hunting pressure could contribute to the absence of large frugivorous birds in forest fragments. The forest fragments in our study, preserved as village‐based protected areas, were not large enough to sustain the bird communities found in continuous forest. However, because these fragments still contained numerous bird species, preservation of such areas can be an important component of management strategies to conserve rainforests and birds in Papua New Guinea.     

Species richness of insect herbivore communities on Ficus in Papua New Guinea

Insect herbivores were sampled from the foliage of 15 species of Ficus (Moraceae) in rainforest and coastal habitats in the Madang area, Papua New Guinea. The collection included 13 193 individuals representing 349 species of leaf-chewing insects and 44 900 individuals representing 430 species of sap-sucking insects. Despite a high sampling intensity, the species accumulation curve did not reach an asymptote. This pattern was attributed to the highly aggregated distribution of insects on individual host trees. The number of insect species collected on a particular Ficus species ranged from 34 to 129 for leaf-chewing and from 51 to 219 for sap-sucking insects. Two Ficus species growing on the seashore sustained less speciose insect communities than their counterparts growing in forest. For the forest figs, significant predictors of insect species richness included leaf palatability and leaf production for leaf-chewing insects (40% of the variance explained), and tree density and leaf expansion for sap-sucking insects (75%). The high faunal overlap among Ficus communities and the importance of local resources for insect herbivores suggest that highly specialized interactions between insect herbivores and Ficus in Papua New Guinea have not been conserved in evolutionary time. This is at variance with the dogma of old, extremely specialized and conservative interactions between insect herbivores and their hosts, providing numerous ecological niches in the floristically rich tropics.     

Predation on artificial and natural nests in the lowland rainforest of Papua New Guinea

Capsule: Although survival of nests was similar between forest fragments and continuous forest, the range of predators differed. Artificial nests provide an under-estimate of nest predation by snakes.

Aims: To estimate the natural nest predation rate in continuous primary forest, compare it with predation rates in forest fragments. To assess the reliability of nest survival rates determined by the use of artificial nests with clay eggs and identify the main nest predators.

Methods: We observed survival of natural nests during the incubation period in continuous primary forest in Papua New Guinea. Some nests were monitored with infrared cameras. We also used artificial nests deployed with clay eggs to identify predators.

Results: There was a predation rate of 50% for natural nests and snakes were major predators of nest contents. Clutch daily survival rates (DSRs) differed among nest types. The DSR of artificial nests (0.977) was not significantly different to that of natural cup nests (0.969). Survival rates of artificial nests were similar in forest fragments and continuous forest. Forest fragments had, however, a higher proportion of avian predators than continuous forest.

Conclusion: Although, we observed similar survival rates in artificial and natural nests, the composition of nest predators was different between natural and artificial nests. Artificial nests were not suitable for estimating the real predation caused by reptiles. Nevertheless, we find that participation of avian nest predators can be estimated correctly with the use of artificial nests.     

Multivariate analysis of periphytic and benthic diatom assemblages from Papua New Guinea

The benthic and periphytic diatom flora is studied in 136 fresh waters in Papua New Guinea. DCA ordination and TWINSPAN are used to describe 20 diatom assemblages. Conductivity, water temperature and altitude are the main sources for the variation in the data. Laing Island Biological Station publication n° 214 Laing Island Biological Station publication n° 214     

Mobility,Violence and the Gendering of HIV in Papua New Guinea

The links between gender, sexuality and violence hold serious implications for HIV transmission and its social and economic effects. In Papua New Guinea, enduring and pervasive patterns of male sexual behaviour involving coercion, violence and gang rape are highly conducive to the transmission of HIV and other sexually transmitted infections and have a critical bearing on women's sexual autonomy and health. The realities of violence are intensified by the widespread view that women are responsible for the spread of the virus. This paper engages the theme of mobility to consider the fluid and dynamic character of gender relations and sexuality in contemporary Papua New Guinea, and to gain perspective on constructions of modern masculinity and the discursive representations of gender violence in the context of the escalating HIV epidemic.     

Ecological succession in new and old swiddens of montane Papua New Guinea

Fieldwork conducted in new and old swiddens in the Maring territory of the Bismarck Mountains of Papua New Guinea indicated a successional sequence of crop composition, diversity, and biomass regulated by human and ecological processes. With increasing swidden age, the number of cultivated species, individuals, varieties, and net productivity decreased. In contrast to new swiddens, old swiddens were characterized by a simplified crop composition and a distinct vertical stratification. While a 3-month-old garden contained 10 cultivar species, 43.5 plantings of taro, a cultivar biomass content of 2.54 kg/25 m², and a net productivity of 1.13 gm/m²/day, a 2-year-old garden contained six cultivar species, no taro plantings, a cultivar biomass content of 13.80 kg/25 m², and a net productivity of 0.77 gm/m²/day. Differences in the life histories of cultivars help determine cultivar succession. This study quantitatively defines these changing characteristics of old and new swiddens. It concludes that the Kauwatyi system of subsistence, which emphasizes diversity and conservation practices, such as the planting and protection of certain forest regrowth species, ensures the regeneration of forest.