Occurrence of Poecilochirus austroasiaticus (Acari: Parasitidae) in forensic autopsies and its application on postmortem interval estimation

Despite the fact that mites were used at the dawn of forensic entomology to elucidate the postmortem interval, their use in current cases remains quite low for procedural reasons such as inadequate taxonomic knowledge. A special interest is focused on the phoretic stages of some mite species, because the phoront-host specificity allows us to deduce in many occasions the presence of the carrier (usually Diptera or Coleoptera) although it has not been seen in the sampling performed in situ or in the autopsy room. In this article, we describe two cases where Poecilochirus austroasiaticus Vitzthum (Acari: Parasitidae) was sampled in the autopsy room. In the first case, we could sample the host, Thanatophilus ruficornis (Küster) (Coleoptera: Silphidae), which was still carrying phoretic stages of the mite on the body. That attachment allowed, by observing starvation/feeding periods as a function of the digestive tract filling, the establishment of chronological cycles of phoretic behavior, showing maximum peaks of phoronts during arrival and departure from the corpse and the lowest values in the phase of host feeding. From the sarcosaprophagous fauna, we were able to determine in this case a minimum postmortem interval of 10 days. In the second case, we found no Silphidae at the place where the corpse was found or at the autopsy, but a postmortem interval of 13 days could be established by the high specificity of this interspecific relationship and the departure from the corpse of this family of Coleoptera.     

On the origins,rapid expansion and genetic diversity of native Americans from hunting‐gatherers to agriculturalists

Given the importance of Y‐chromosome haplogroup Q to better understand the source populations of contemporary Native Americans, we studied 8 biallelic and 17 microsatellite polymorphisms on the background of 128 Q Y‐chromosomes from geographically targeted populations. The populations examined in this study include three from the Tuva Republic in Central Asia (Bai‐Tai, Kungurtug, and Toora‐Hem, n = 146), two from the northeastern tip of Siberia (New Chaplino and Chukchi, n = 32), and two from Mesoamerica (Mayans from Yucatan, Mexico n = 72, and Mayans from the Guatemalan Highlands, n = 43). We also see evidence of a dramatic Mesoamerican post‐migration population growth in the ubiquitous and diverse Y‐STR profiles of the Mayan and other Mesoamerican populations. In the case of the Mayans, this demographic growth was most likely fueled by the agricultural‐ and trade‐based subsistence adopted during the Pre‐Classic, Classic and Post‐Classic periods of their empire. The limited diversity levels observed in the Altaian and Tuvinian regions of Central Asia, the lowest of all populations examined, may be the consequence of bottleneck events fostered by the spatial isolation and low effective population size characteristic of a nomadic lifestyle. Furthermore, our data illustrate how a sociocultural characteristic such as mode of subsistence may be of impact on the genetic structure of populations. We analyzed our genetic data using Multidimensional Scaling Analysis of populations, Principal Component Analysis of individuals, Median‐joining networks of M242, M346, L54, and M3 individuals, age estimations based on microsatellite variation utilizing genealogical and evolutionary mutation rates/generation times and estimation of Y‐ STR average gene diversity indices. Am J Phys Anthropol, 2013. © 2013 Wiley Periodicals, Inc.     

The Himalayas: Barrier and conduit for gene flow

The Himalayan mountain range is strategically located at the crossroads of the major cultural centers in Asia, the Middle East and Europe. Although previous Y‐chromosome studies indicate that the Himalayas served as a natural barrier for gene flow from the south to the Tibetan plateau, this region is believed to have played an important role as a corridor for human migrations between East and West Eurasia along the ancient Silk Road. To evaluate the effects of the Himalayan mountain range in shaping the maternal lineages of populations residing on either side of the cordillera, we analyzed mitochondrial DNA variation in 344 samples from three Nepalese collections (Newar, Kathmandu and Tamang) and a general population of Tibet. Our results revealed a predominantly East Asian‐specific component in Tibet and Tamang, whereas Newar and Kathmandu are both characterized by a combination of East and South Central Asian lineages. Interestingly, Newar and Kathmandu harbor several deep‐rooted Indian lineages, including M2, R5, and U2, whose coalescent times from this study (U2, >40 kya) and previous reports (M2 and R5, >50 kya) suggest that Nepal was inhabited during the initial peopling of South Central Asia. Comparisons with our previous Y‐chromosome data indicate sex‐biased migrations in Tamang and a founder effect and/or genetic drift in Tamang and Newar. Altogether, our results confirm that while the Himalayas acted as a geographic barrier for human movement from the Indian subcontinent to the Tibetan highland, it also served as a conduit for gene flow between Central and East Asia. Am J Phys Anthropol 151:169–182, 2013. © 2013 Wiley Periodicals, Inc.     

Agroecosystems and conservation of migratory waterbirds: importance of coastal pastures and factors influencing their use by wintering shorebirds

Coastal pastures are common agroecosystems adjacent to estuarine areas that can provide valuable habitat for wildlife, particularly for migratory shorebirds. Disentangling the factors that influence coastal pasture use by wintering shorebirds will provide new insights into its role for buffering human disturbances and habitat loss in intertidal areas. We examined whether numbers of two shorebirds (Eurasian curlew and Black-tailed godwit) foraging actively on coastal pastures was affected by weather conditions, tidal stage (low/high tide) and number of harvesters at intertidal areas throughout winter. Both species frequently used coastal pastures and most individuals foraged actively there. The average percentage of the total wintering population of curlews and godwits foraging on coastal pastures was 27.4 and 7.8 %, respectively, and was significantly higher during high tide compared to low tide. The number of harvesters on mudflats also had a positive significant effect in explaining the presence of curlews, and to a lesser extent for godwits, on coastal pastures, and accumulated rainfall had a positive effect for both species too. These supratidal areas were consistently used as alternative foraging grounds during low tide by curlews, as well as supplementary foraging areas during high tide by wintering populations of both large shorebirds. By supplementary foraging, wintering curlews, and probably godwits, seemed to compensate for a negative effect of the presence of harvesters on their foraging activity. We recommend managing of those coastal agricultural fields adjacent to intertidal foraging grounds in order to increase the availability of supratidal foraging habitats for declining shorebird populations. These habitats may thus have a beneficial role in sustaining populations of wintering shorebirds, but further studies are needed to estimate if birds can compensate for any shortfall in daily energy budget by supplementary foraging on coastal pastures, thus providing insights into whether they are involved in large-scale population regulation of migratory birds.     

Rice bran enzymatic extract restores endothelial function and vascular contractility in obese rats by reducing vascular inflammation and oxidative stress

BackgroundRice bran enzymatic extract (RBEE) used in this study has shown beneficial activities against dyslipidemia, hyperinsulinemia and hypertension. Our aim was to investigate the effects of a diet supplemented with RBEE in vascular impairment developed in obese Zucker rats and to evaluate the main mechanisms mediating this action.Methods and resultsObese Zucker rats were fed a 1% and 5% RBEE-supplemented diet (O1% and O5%). Obese and their lean littermates fed a standard diet were used as controls (OC and LC, respectively). Vascular function was evaluated in aortic rings in organ baths. The role of nitric oxide (NO) was investigated by using NO synthase (NOS) inhibitors. Aortic expression of endothelial NOS (eNOS), inducible NOS (iNOS), tumor necrosis factor (TNF)-α and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits and superoxide production in arterial wall were determined. Endothelial dysfunction and vascular hyperreactivity to phenylephrine in obese rats were ameliorated by RBEE treatment, particularly with 1% RBEE. Up-regulation of eNOS protein expression in RBEE-treated aortas should contribute to this activity. RBEE attenuated vascular inflammation by reducing aortic iNOS and TNF-α expression. Aortas from RBEE-treated groups showed a significant decrease of superoxide production and down-regulation of NADPH oxidase subunits.ConclusionRBEE treatment restored endothelial function and vascular contractility in obese Zucker rats through a reduction of vascular inflammation and oxidative stress. These results show the nutraceutical potential of RBEE to prevent obesity-related vascular complications.     

Proteome wide evaluation of the separation ability of hydrophobic interaction chromatography by fluorescent dye binding analysis

Hydrophobic interaction chromatography (HIC) is an important tool in the industrial purification of proteins from various sources. The HIC separation behavior of individual (or model) proteins has been widely researched by others. On the contrary, this study focused on the fractionation ability of HIC when it is challenged with whole proteomes. The impact of the nature of three different proteomes, that is, yeast, soybean, and Chinese hamster ovary cells, on HIC separation was investigated. In doing so, chromatography fractions obtained under standardized conditions were evaluated in terms of their overall hydrophobicity—as measured by fluorescence dye binding. This technique allowed for the calculation of an average protein surface hydrophobicity (S₀) for each fraction; a unique correlation between S₀ and the observed chromatographic behavior was established in each case. Following a similar strategy, the effect of three different ligands (polypropylene glycol, phenyl, and butyl) and two adsorbent particle sizes (65 and 100 µm) on the chromatographic behavior of the yeast proteome was evaluated. As expected, the superficial hydrophobicity of the proteins eluted is correlated with the salt concentration of its corresponding elution step. The findings reveled how—and in which extent—the type of ligand and the size of the beads actually influenced the fractionation of the complex biological mixture. Summarizing, the approach presented here can be instrumental to the study of the performance of chromatography adsorbents under conditions close to industrial practice and to the development of downstream processing strategies. Copyright © 2013 John Wiley & Sons, Ltd.     

Functional heterogeneity in a plant–frugivore assemblage enhances seed dispersal resilience to habitat loss

The ability of ecosystems to maintain their functions after disturbance (ecological resilience) depends on heterogeneity in the functional capabilities among species within assemblages. Functional heterogeneity may affect resilience by determining multiplicity between species in the provision of functions (redundancy) and complementarity between species in their ability to respond to disturbances (response diversity), but also by promoting the maintenance of biological information that enables ecosystems to reorganize themselves (ecological memory). Here, we assess the role of the components of the functional heterogeneity of a plant–frugivore assemblage on the resilience of seed dispersal to habitat loss. For three years, we quantified the distributions of fruits, frugivorous thrushes (Turdus spp.) and dispersed seeds, as well as frugivore diet and movement, along a gradient of forest cover in N Spain. The abundances and the spatial distributions of fruits and birds varied between years. The different thrushes showed similar diets but differed in spatial behavior and response to habitat loss, suggesting the occurrence of both functional redundancy and response diversity. Forest cover and fruit availability affected the spatial distribution of the whole frugivore assemblage. Fruit tracking was stronger in years when fruits were scarcer but more widespread across the whole fragmented landscape, entailing larger proportions of seeds dispersed to areas of low forest cover and open microhabitats. Rather than depending on redundancy and/or response diversity, seed dispersal resilience mostly emerged from the ecological memory conferred by the inter‐annual variability in fruit production and the ability of thrushes to track fruit resources across the fragmented landscape. Ecological memory also derived from the interaction of plants and frugivores as source organisms (trees in undisturbed forest), mobile links (birds able to disperse seeds into the disturbed habitat), and biological legacies (remnant trees and small forest patches offering scattered fruit resources across the landscape).     

Developmental Basis of Phallus Reduction during Bird Evolution

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Quantification of Anti‐Addictive Alkaloids Ibogaine and Voacangine in In Vivo‐ and In Vitro‐Grown Plants of Two Mexican Tabernaemontana Species

Tabernaemontana alba and Tabernaemontana arborea are Apocynaceae species used in Mexican traditional medicine for which little phytochemical information exists. In this study, preliminary gas chromatography/mass spectrometry analyses of different organs obtained from wild plants of both species identified a total of 10 monoterpenoid indole alkaloids (MIAs) and one simple indole alkaloid, nine of which were reported for the first time in these species. Furthermore, callus cultures were established from T. alba leaf explants and regeneration of whole plants was accomplished via somatic embryogenesis. The anti‐addictive MIAs ibogaine and voacangine were then quantified by gas chromatography with flame ionization detection in wild plants of both species, as well as greenhouse‐grown plants, in vitro‐grown plantlets and embryogenic callus of T. alba. Ibogaine and voacangine were present in most samples taken from the whole plants of both species, with stem and root barks showing the highest concentrations. No alkaloids were detected in callus samples. It was concluded that T. alba and T. arborea are potentially viable sources of ibogaine and voacangine, and that these MIAs can be produced through somatic embryogenesis and whole plant regeneration of T. alba. Approaches to increase MIA yields in whole plants and to achieve alkaloid production directly in cell cultures are discussed.