Biodiversity and parasites of wildlife: helminths of Australasian marsupials.

PubMed

Beveridge, Ian; Spratt, David M

2015-04-01

Despite current attempts to document the extent of biodiversity on Earth, significant problems exist in fully documenting the helminth parasites of wildlife. Using the Australasian marsupials as an example, we examine some of these difficulties, including challenges in collecting uncommon host species, the ongoing description of new species of marsupials, the presence of cryptic species, and the decline in taxonomic expertise in Australia. Although optimistic global predictions have been made concerning the rate of discovery and description of new species of animals, these predictions may not apply in the case of specific groups of animals such as the Australasian marsupials. Copyright © 2014 Elsevier Ltd. All rights reserved.

Targeted gene flow and rapid adaptation in an endangered marsupial.

PubMed

Kelly, Ella; Phillips, Ben L

2018-06-13

Targeted gene flow is an emerging conservation strategy. It involves translocating individuals with favorable genes to areas where they will have a conservation benefit. The applications for targeted gene flow are wide-ranging, but include pre-adapting natives to the arrival of invasive species. The endangered carnivorous marsupial, the northern quoll, has declined rapidly since the introduction of the cane toad, which fatally poisons quolls that attack them. There are, however, a few remaining toad-invaded quoll populations in which the quolls survive because they know not to eat cane toads. It is this "toad-smart" behavior that we hope to promote through targeted gene flow. For targeted gene flow to be feasible, however, toad-smarts must have a genetic basis. To assess this, we used a common garden experiment and found offspring from toad-exposed populations were substantially less likely to eat toads than those with toad-naïve parents. Hybrid offspring showed similar responses to quolls with two toad-exposed parents, indicating the trait may be dominant. Together, these results suggest a heritable trait and rapid adaptive response in small number of toad-impacted populations. Although questions remain about outbreeding depression, our results are encouraging for targeted gene flow: suggesting it should be possible to introduce toad-smart behavior into soon to be impacted quoll populations. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The functional and anatomical organization of marsupial neocortex: Evidence for parallel evolution across mammals

PubMed Central

Karlen, Sarah J.; Krubitzer, Leah

2007-01-01

Marsupials are a diverse group of mammals that occupy a large range of habitats and have evolved a wide array of unique adaptations. Although they are as diverse as placental mammals, our understanding of marsupial brain organization is more limited. Like placental mammals, marsupials have striking similarities in neocortical organization, such as a constellation of cortical fields including S1, S2, V1, V2, and A1, that are functionally, architectonically, and connectionally distinct. In this review, we describe the general lifestyle and morphological characteristics of all marsupials and the organization of somatosensory, motor, visual, and auditory cortex. For each sensory system, we compare the functional organization and the corticocortical and thalamocortical connections of the neocortex across species. Differences between placental and marsupial species are discussed and the theories on neocortical evolution that have been derived from studying marsupials, particularly the idea of a sensorimotor amalgam, are evaluated. Overall, marsupials inhabit a variety of niches and assume many different lifestyles. For example, marsupials occupy terrestrial, arboreal, burrowing, and aquatic environments; some animals are highly social while others are solitary; and different species are carnivorous, herbivorous, or omnivorous. For each of these adaptations, marsupials have evolved an array of morphological, behavioral, and cortical specializations that are strikingly similar to those observed in placental mammals occupying similar habitats, which indicate that there are constraints imposed on evolving nervous systems that result in recurrent solutions to similar environmental challenges. PMID:17507143

DNA hybridization evidence for the Australasian affinity of the American marsupial Dromiciops australis.

PubMed Central

Kirsch, J A; Dickerman, A W; Reig, O A; Springer, M S

1991-01-01

DNA hybridization was used to compare representatives of the major groups of marsupials and a eutherian outgroup. Because of the large genetic distances separating marsupial families, trees were calculated from normalized percentages of hybridization; thermal-melting statistics, however, gave identical topologies for the well-supported clades. The most notable results were the association of the only extant microbiotheriid, Dromiciops australis, an American marsupial, with the Australasian Diprotodontia, and of both together with the Dasyuridae. Estimates of the rate of divergence among marsupial genomes suggest that the Dromiciops-Diprotodontia split occurred approximately 50 million years ago, well after the establishment of the major clades of marsupials but before deep oceanic barriers prohibited dispersal among Australia, Antarctica, and South America. Because Dromiciops is nested within an Australasian group, it seems likely that dispersal from Australia accounts for its present distribution. Images PMID:1961710

Inducing sex reversal of the urogenital system of marsupials.

PubMed

Renfree, Marilyn B; Chew, Keng Yih; Shaw, Geoff

2014-01-01

Marsupials differ from eutherian mammals in their reproductive strategy of delivering a highly altricial young after a short gestation. The young, with its undeveloped organ systems completes its development post-natally, usually within a pouch. The young is dependent on milk with a composition that varies through lactation to support its growth and changing needs as it matures over a lengthy period. Gonadal differentiation occurs after birth, providing a unique opportunity to examine the effects of hormonal manipulations on its sexual differentiation of the highly accessible young. In marsupials a difference in the migration of the urinary ducts around the genital ducts from eutherian mammals results in the unique tammar reproductive tract which has three vaginae and two cervices, and two distinctly separate uteri. In the tammar wallaby, a small member of the kangaroo family, we showed that virilisation of the Wolffian duct, prostate and phallus depends on an alternate androgen pathway, which has now been shown to be important for virilisation in humans. Through hormonal manipulations over differing time periods we have achieved sex reversal of both ovaries and testes, germ cells, genital ducts, prostate and phallus. Whilst we understand many of the mechanisms behind sexual differentiation there are still many lessons to be learned from understanding how sex reversal is achieved by using a model such as the tammar wallaby. This will help guide investigations into the major questions of how and why sex determination is achieved in other species. This review discusses the control and development of the marsupial urogenital system, largely drawn from our studies in the tammar wallaby and our ability to manipulate this system to induce sex reversal. Copyright © 2013 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

Manipulation of the fertility of marsupials for conservation of endangered species and control of over-abundant populations.

PubMed

Mate, K E; Molinia, F C; Rodger, J C

1998-10-01

Marsupials present a dichotomy in population management; the numbers of many Australian marsupial species have declined due to loss of habitat, competition from introduced herbivores and predation by introduced carnivores, but other species have become locally overabundant in Australia or are introduced pests in New Zealand. The manipulation of reproduction offers the means to increase or decrease productivity; however, considerable fundamental research is required before reproductive technologies can be applied to marsupials. Marsupials differ from eutherian mammals in several aspects of their reproduction including sex differentiation, gamete function and endocrinology, as well as in the relative lengths of gestation and lactation. Although these differences present unique problems in the application of reproductive technologies to marsupials, they also present unique opportunities for marsupial-specific fertility control. This paper summarises the assisted breeding technologies currently being applied to marsupials including superovulation, artificial insemination, in vitro fertilization and gene banking; unique marsupial targets for contraceptive intervention including gamete production, sperm capacitation, gamete surface antigens and embryonic development; and some options for the delivery of contraceptive vaccines to marsupial populations.

Implant placement after marsupialization of a dentigerous cyst.

PubMed

Karamanis, S; Kitharas, T; Tsoukalas, D; Parissis, N

2006-01-01

This paper presents a case of a dentigerous cyst accompanied by a history of inflammation, resorption of the roots of the first molar and the lingual aspect of the distal root of the second molar, and devitalization of the 2 premolars. The treatment option chosen was marsupialization of the cyst, extraction of the involved teeth, endodontic treatment of both premolars, and implant insertion in the area of the first mandibular molar at a later stage. Twelve months postsurgery the area of interest was almost flattened and the radiographic examination revealed total disappearance of the radiolucency. An implant of 15 x 4 mm was inserted in the area of the first mandibular molar. Despite the excellent implant stability achieved, a thin central zone of the defect remained void of bone. After complete excision of soft tissue the defect was filled with an alloplastic bone substitute. Eight months later (20 months postsurgery), the implant was uncovered and the restorative procedure completed. The implant and the crown have been functioning sign and symptom free for 48 months. Marsupialization was preferred instead of enucleation due to (1) proximity of the cyst to the mandibular canal; (2) need for apicectomy of both premolars to gain good access for enucleation; (3) refusal of the patient to undergo a second surgery for bone harvesting; (4) lower probability for postoperative contamination; (5) need of small quantity of bone substitute; (6) easier extraction of the impacted second molar due to its coronal movement. The disadvantages of the treatment were the long healing period and the discomfort of the patient at the early stages of marsupialization. It was judged that the advantages outweighed the disadvantages in this case. We discuss the findings of other authors who support the conservative approach to jaw cysts in a young population, and the concerns that exist in the literature about the ability of osseoconductive graft materials to generate vital bone and achieve

Is Toxoplasma gondii a threat to the conservation of free-ranging Australian marsupial populations?

PubMed Central

Hillman, Alison E.; Lymbery, Alan J.; Thompson, R.C. Andrew

2015-01-01

It has often been asserted that Australian marsupial species are particularly susceptible to Toxoplasma gondii infection and to clinical toxoplasmosis following infection. This implicates T. gondii as a potential threat to marsupial population viability, and contrasts to what is known of T. gondii in populations of several other host species. We reviewed the literature, and found a lack of scientifically robust evidence addressing the occurrence of T. gondii infection in free-ranging populations of Australian marsupial species, and the impacts of the infection on population health. Key limitations included a lack of studies in free-ranging marsupial populations, study findings susceptible to substantial chance influences, and selection, misclassification and confounding biases. The lack of scientifically robust data available on this topic indicates that assertions that free-ranging populations of Australian marsupials are particularly susceptible to T. gondii infection and to toxoplasmosis are premature. The threat of T. gondii to the viability of free-ranging marsupial populations should therefore be regarded, at this stage, as a hypothesis. PMID:27141439

Inducing Sex Reversal in Marsupial Mammals.

PubMed

Chew, Keng Y; Renfree, Marilyn B

2016-01-01

Marsupials are born with undifferentiated gonads, and their reproductive organs differentiate consecutively, not simultaneously as in eutherian mammals. Thus, in the main marsupial model, the tammar wallaby, Macropus eugenii, the testis forms cords 2 days after birth, the ovary develops cortex and medulla about 8 days after birth, the Wolffian duct enlarges from day 10, the prostate begins to form prostatic buds about 25 days after birth, and the phallus does not become sexually dimorphic until after 50 days postpartum (pp). The brain responses also become sexually dimorphic relatively late in development, after day 25 pp. This relatively elongated period of differentiation has allowed experimental manipulation at each stage of development to induce often dramatic sex reversal of both internal and external genitalia. © 2016 S. Karger AG, Basel.

Implications of monotreme and marsupial chromosome evolution on sex determination and differentiation.

PubMed

Deakin, Janine E

2017-04-01

Studies of chromosomes from monotremes and marsupials endemic to Australasia have provided important insight into the evolution of their genomes as well as uncovering fundamental differences in their sex determination/differentiation pathways. Great advances have been made this century into solving the mystery of the complicated sex chromosome system in monotremes. Monotremes possess multiple different X and Y chromosomes and a candidate sex determining gene has been identified. Even greater advancements have been made for marsupials, with reconstruction of the ancestral karyotype enabling the evolutionary history of marsupial chromosomes to be determined. Furthermore, the study of sex chromosomes in intersex marsupials has afforded insight into differences in the sexual differentiation pathway between marsupials and eutherians, together with experiments showing the insensitivity of the mammary glands, pouch and scrotum to exogenous hormones, led to the hypothesis that there is a gene (or genes) on the X chromosome responsible for the development of either pouch or scrotum. This review highlights the major advancements made towards understanding chromosome evolution and how this has impacted on our understanding of sex determination and differentiation in these interesting mammals. Copyright © 2015 Elsevier Inc. All rights reserved.

The development of the olfactory organs in newly hatched monotremes and neonate marsupials

PubMed Central

Schneider, Nanette Yvette

2011-01-01

Olfactory cues are thought to play a crucial role in the detection of the milk source at birth in mammals. It has been shown that a marsupial, the tammar wallaby, can detect olfactory cues from its mother's pouch at birth. This study investigates whether the main olfactory and accessory olfactory system are similarly well developed in other marsupials and monotremes at birth/hatching as in the tammar. Sections of the head of various marsupial and two monotreme species were investigated by light microscopy. Both olfactory systems were less well developed in the kowari and Eastern quoll. No olfactory or vomeronasal or terminal nerves could be observed; the main olfactory bulb (MOB) had only two layers while no accessory olfactory bulb or ganglion terminale were visible. All other investigated marsupials and monotremes showed further developed olfactory systems with olfactory, vomeronasal and terminal nerves, a three-layered MOB, and in the marsupials a prominent ganglion terminale. The main olfactory system was further developed than the accessory olfactory system in all species investigated. The olfactory systems were the least developed in species in which the mother's birth position removed most of the difficulty in reaching the teat, placing the neonate directly in the pouch. In monotremes they were the furthest developed as Bowman glands were found underlying the main olfactory epithelium. This may reflect the need to locate the milk field each time they drink as they cannot permanently attach to it, unlike therian mammals. While it still needs to be determined how an odour signal could be further processed in the brain, this study suggests that marsupials and monotremes possess well enough developed olfactory systems to be able to detect an odour cue from the mammary area at birth/hatching. It is therefore likely that neonate marsupials and newly hatched monotremes find their way to the milk source using olfactory cues, as has been previously suggested for the

Behaviour of the Pleistocene marsupial lion deduced from claw marks in a southwestern Australian cave.

PubMed

Arman, Samuel D; Prideaux, Gavin J

2016-02-15

The marsupial lion, Thylacoleo carnifex, was the largest-ever marsupial carnivore, and is one of the most iconic extinct Australian vertebrates. With a highly-specialised dentition, powerful forelimbs and a robust build, its overall morphology is not approached by any other mammal. However, despite >150 years of attention, fundamental aspects of its biology remain unresolved. Here we analyse an assemblage of claw marks preserved on surfaces in a cave and deduce that they were generated by marsupial lions. The distribution and skewed size range of claw marks within the cave elucidate two key aspects of marsupial lion biology: they were excellent climbers and reared young in caves. Scrutiny of >10,000 co-located Pleistocene bones reveals few if any marsupial lion tooth marks, which dovetails with the morphology-based interpretation of the species as a flesh specialist.

Gradients in cytoarchitectural landscapes of the isocortex: Diprotodont marsupials in comparison to eutherian mammals.

PubMed

Charvet, Christine J; Stimpson, Cheryl D; Kim, Young Do; Raghanti, Mary Ann; Lewandowski, Albert H; Hof, Patrick R; Gómez-Robles, Aida; Krienen, Fenna M; Sherwood, Chet C

2017-06-01

Although it has been claimed that marsupials possess a lower density of isocortical neurons compared with other mammals, little is known about cross-cortical variation in neuron distributions in this diverse taxonomic group. We quantified upper-layer (layers II-IV) and lower-layer (layers V-VI) neuron numbers per unit of cortical surface area in three diprotodont marsupial species (two macropodiformes, the red kangaroo and the parma wallaby, and a vombatiform, the koala) and compared these results to eutherian mammals (e.g., xenarthrans, rodents, primates). In contrast to the notion that the marsupial isocortex contains a low density of neurons, we found that neuron numbers per unit of cortical surface area in several marsupial species overlap with those found in eutherian mammals. Furthermore, neuron numbers vary systematically across the isocortex of the marsupial mammals examined. Neuron numbers under a unit of cortical surface area are low toward the frontal cortex and high toward the caudo-medial (occipital) pole. Upper-layer neurons (i.e., layers II-IV) account for most of the variation in neuron numbers across the isocortex. The variation in neuron numbers across the rostral to the caudal pole resembles primates. These findings suggest that diprotodont marsupials and eutherian mammals share a similar cortical architecture despite their distant evolutionary divergence. © 2017 Wiley Periodicals, Inc.

Atlantic small-mammal: a dataset of communities of rodents and marsupials of the Atlantic forests of South America.

PubMed

Bovendorp, Ricardo S; Villar, Nacho; de Abreu-Junior, Edson F; Bello, Carolina; Regolin, André L; Percequillo, Alexandre R; Galetti, Mauro

2017-08-01

The contribution of small mammal ecology to the understanding of macroecological patterns of biodiversity, population dynamics, and community assembly has been hindered by the absence of large datasets of small mammal communities from tropical regions. Here we compile the largest dataset of inventories of small mammal communities for the Neotropical region. The dataset reviews small mammal communities from the Atlantic forest of South America, one of the regions with the highest diversity of small mammals and a global biodiversity hotspot, though currently covering less than 12% of its original area due to anthropogenic pressures. The dataset comprises 136 references from 300 locations covering seven vegetation types of tropical and subtropical Atlantic forests of South America, and presents data on species composition, richness, and relative abundance (captures/trap-nights). One paper was published more than 70 yr ago, but 80% of them were published after 2000. The dataset comprises 53,518 individuals of 124 species of small mammals, including 30 species of marsupials and 94 species of rodents. Species richness averaged 8.2 species (1-21) per site. Only two species occurred in more than 50% of the sites (the common opossum, Didelphis aurita and black-footed pigmy rice rat Oligoryzomys nigripes). Mean species abundance varied 430-fold, from 4.3 to 0.01 individuals/trap-night. The dataset also revealed a hyper-dominance of 22 species that comprised 78.29% of all individuals captured, with only seven species representing 44% of all captures. The information contained on this dataset can be applied in the study of macroecological patterns of biodiversity, communities, and populations, but also to evaluate the ecological consequences of fragmentation and defaunation, and predict disease outbreaks, trophic interactions and community dynamics in this biodiversity hotspot. © 2017 by the Ecological Society of America.

Genome-wide histone state profiling of fibroblasts from the opossum, Monodelphis domestica, identifies the first marsupial-specific imprinted gene

PubMed Central

2014-01-01

Background Imprinted genes have been extensively documented in eutherian mammals and found to exhibit significant interspecific variation in the suites of genes that are imprinted and in their regulation between tissues and developmental stages. Much less is known about imprinted loci in metatherian (marsupial) mammals, wherein studies have been limited to a small number of genes previously known to be imprinted in eutherians. We describe the first ab initio search for imprinted marsupial genes, in fibroblasts from the opossum, Monodelphis domestica, based on a genome-wide ChIP-seq strategy to identify promoters that are simultaneously marked by mutually exclusive, transcriptionally opposing histone modifications. Results We identified a novel imprinted gene (Meis1) and two additional monoallelically expressed genes, one of which (Cstb) showed allele-specific, but non-imprinted expression. Imprinted vs. allele-specific expression could not be resolved for the third monoallelically expressed gene (Rpl17). Transcriptionally opposing histone modifications H3K4me3, H3K9Ac, and H3K9me3 were found at the promoters of all three genes, but differential DNA methylation was not detected at CpG islands at any of these promoters. Conclusions In generating the first genome-wide histone modification profiles for a marsupial, we identified the first gene that is imprinted in a marsupial but not in eutherian mammals. This outcome demonstrates the practicality of an ab initio discovery strategy and implicates histone modification, but not differential DNA methylation, as a conserved mechanism for marking imprinted genes in all therian mammals. Our findings suggest that marsupials use multiple epigenetic mechanisms for imprinting and support the concept that lineage-specific selective forces can produce sets of imprinted genes that differ between metatherian and eutherian lines. PMID:24484454

Scaling of cerebral blood perfusion in primates and marsupials.

PubMed

Seymour, Roger S; Angove, Sophie E; Snelling, Edward P; Cassey, Phillip

2015-08-01

The evolution of primates involved increasing body size, brain size and presumably cognitive ability. Cognition is related to neural activity, metabolic rate and rate of blood flow to the cerebral cortex. These parameters are difficult to quantify in living animals. This study shows that it is possible to determine the rate of cortical brain perfusion from the size of the internal carotid artery foramina in skulls of certain mammals, including haplorrhine primates and diprotodont marsupials. We quantify combined blood flow rate in both internal carotid arteries as a proxy of brain metabolism in 34 species of haplorrhine primates (0.116-145 kg body mass) and compare it to the same analysis for 19 species of diprotodont marsupials (0.014-46 kg). Brain volume is related to body mass by essentially the same exponent of 0.70 in both groups. Flow rate increases with haplorrhine brain volume to the 0.95 power, which is significantly higher than the exponent (0.75) expected for most organs according to 'Kleiber's Law'. By comparison, the exponent is 0.73 in marsupials. Thus, the brain perfusion rate increases with body size and brain size much faster in primates than in marsupials. The trajectory of cerebral perfusion in primates is set by the phylogenetically older groups (New and Old World monkeys, lesser apes) and the phylogenetically younger groups (great apes, including humans) fall near the line, with the highest perfusion. This may be associated with disproportionate increases in cortical surface area and mental capacity in the highly social, larger primates. © 2015. Published by The Company of Biologists Ltd.

Treatment of mucus retention phenomena in children by the micro-marsupialization technique: case reports.

PubMed

Delbem, A C; Cunha, R F; Vieira, A E; Ribeiro, L L

2000-01-01

The purpose of the present study was to emphasize the technique of micro-marsupialization as an alternative for the treatment of mucus retention phenomena. Out of 41 patients, 14 were selected for treatment by the micro-marsupialization technique on the basis of clinical criteria. Patient age ranged from 5-9 years. The technique was performed as follows: the area was disinfected with 0.1% iodine; a topical anesthetic was applied to cover the entire lesion for approximately 3 min; a 4.0 silk suture was passed through the internal part of the lesion along its widest diameter; and a surgical knot was made. Of the original 14 patients treated by the micro-marsupialization technique, 12 presented full regression one week after treatment. Recurrence occurred in two cases. It was possible to conclude that the micro-marsupialization technique is an alternative to be considered, especially in pediatric dentistry.

The key to winter survival: daily torpor in a small arid-zone marsupial

NASA Astrophysics Data System (ADS)

Körtner, Gerhard; Geiser, Fritz

2009-04-01

Mammalian hibernation, which lasts on average for about 6 months, can reduce energy expenditure by >90% in comparison to active individuals. In contrast, the widely held view is that daily torpor reduces energy expenditure usually by about 30%, is employed for a few hours every few days, and often occurs only under acute energetic stress. This interpretation is largely based on laboratory studies, whereas knowledge on daily torpor in the field is scant. We used temperature telemetry to quantify thermal biology and activity patterns of a small arid-zone marsupial, the stripe-faced dunnart Sminthopsis macroura (16.9 g), in the wild and to test the hypothesis that daily torpor is a crucial survival strategy of this species in winter. All individuals entered torpor daily with the exception of a single male that remained normothermic for a single day (torpor on 212 of 213 observation days, 99.5%). Torpor was employed at air temperatures ( T a) ranging from approximately -1°C to 36°C. Dunnarts usually entered torpor during the night and aroused at midday with the daily increase of T a. Torpor was on average about twice as long (mean 11.0 ± 4.7 h, n = 8) than in captivity. Animals employed sun basking during rewarming, reduced foraging time significantly, and occasionally omitted activity for several days in sequence. Consequently, we estimate that daily torpor in this species can reduce daily energy expenditure by up to 90%. Our study shows that for wild stripe-faced dunnarts daily torpor is an essential mechanism for overcoming energetic challenges during winter and that torpor data obtained in the laboratory can substantially underestimate the ecological significance of daily torpor in the wild.

Do Developmental Constraints and High Integration Limit the Evolution of the Marsupial Oral Apparatus?

PubMed

Goswami, Anjali; Randau, Marcela; Polly, P David; Weisbecker, Vera; Bennett, C Verity; Hautier, Lionel; Sánchez-Villagra, Marcelo R

2016-09-01

Developmental constraints can have significant influence on the magnitude and direction of evolutionary change, and many studies have demonstrated that these effects are manifested on macroevolutionary scales. Phenotypic integration, or the strong interactions among traits, has been similarly invoked as a major influence on morphological variation, and many studies have demonstrated that trait integration changes through ontogeny, in many cases decreasing with age. Here, we unify these perspectives in a case study of the ontogeny of the mammalian cranium, focusing on a comparison between marsupials and placentals. Marsupials are born at an extremely altricial state, requiring, in most cases, the use of the forelimbs to climb to the pouch, and, in all cases, an extended period of continuous suckling, during which most of their development occurs. Previous work has shown that marsupials are less disparate in adult cranial form than are placentals, particularly in the oral apparatus, and in forelimb ontogeny and adult morphology, presumably due to functional selection pressures on these two systems during early postnatal development. Using phenotypic trajectory analysis to quantify prenatal and early postnatal cranial ontogeny in 10 species of therian mammals, we demonstrate that this pattern of limited variation is also apparent in the development of the oral apparatus of marsupials, relative to placentals, but not in the skull more generally. Combined with the observation that marsupials show extremely high integration of the oral apparatus in early postnatal ontogeny, while other cranial regions show similar levels of integration to that observed in placentals, we suggest that high integration may compound the effects of the functional constraints for continuous suckling to ultimately limit the ontogenetic and adult disparity of the marsupial oral apparatus throughout their evolutionary history. © The Author 2016. Published by Oxford University Press on behalf of

Functional-adaptive anatomy of the axial skeleton of some extant marsupials and the paleobiology of the paleocene marsupials Mayulestes ferox and Pucadelphys andinus.

PubMed

Argot, Christine

2003-03-01

In this study, the axial skeletons of two Early Paleocene marsupials, Mayulestes ferox and Pucadelphys andinus, were analyzed functionally and compared to that of six South American and three Australian species of extant marsupials. In the case of the South American opossums, myological data of the epaxial musculature were collected and analyzed and osteological-myological associations were related to locomotor behavior. Various features of the vertebral column that relate to diet or to locomotor or postural patterns were pointed out. These features include: the craniocaudal development of the neural process of the axis; the position of the anticlinal vertebra; the morphology of the neural processes of the thoracolumbar vertebrae (orientation, length, and craniocaudal width); the length, orientation, and curvature of the transverse processes of the lumbar vertebrae; and the length and robustness of the caudal vertebrae. In both fossil forms the vertebral column is mobile and allows a great range of flexion and extension of the spine, more so than in most of the living didelphids. It is emphasized here that the analysis of the axial skeleton complements and improves the conclusions provided by the forelimb and hindlimb analyses. It is proposed that Mayulestes and Pucadelphys represent an ancestral morphotype suggesting that the generalized type of locomotion of Paleocene marsupials was partly terrestrial with some climbing ability. Copyright 2003 Wiley-Liss, Inc.

Forelimb preferences in quadrupedal marsupials and their implications for laterality evolution in mammals

PubMed Central

2013-01-01

Background Acquisition of upright posture in evolution has been argued to facilitate manual laterality in primates. Owing to the high variety of postural habits marsupials can serve as a suitable model to test whether the species-typical body posture shapes forelimb preferences in non-primates or this phenomenon emerged only in the course of primate evolution. In the present study we aimed to explore manual laterality in marsupial quadrupeds and compare them with the results in the previously studied bipedal species. Forelimb preferences were assessed in captive grey short-tailed opossum (Monodelphis domestica) and sugar glider (Petaurus breviceps) in four different types of unimanual behaviour per species, which was not artificially evoked. We examined the possible effects of sex, age and task, because these factors have been reported to affect motor laterality in placental mammals. Results In both species the direction of forelimb preferences was strongly sex-related. Male grey short-tailed opossums showed right-forelimb preference in most of the observed unimanual behaviours, while male sugar gliders displayed only a slight, not significant rightward tendency. In contrast, females in both species exhibited consistent group-level preference of the left forelimb. We failed to reveal significant differences in manual preferences between tasks of potentially differing complexity: reaching a stable food item and catching live insects, as well as between the body support and food manipulation. No influence of subjects’ age on limb preferences was found. Conclusions The direction of sex-related differences in the manual preferences found in quadrupedal marsupials seems to be not typical for placental mammals. We suggest that the alternative way of interhemispheric connection in absence of corpus callosum may result in a fundamentally distinct mechanism of sex effect on limb preferences in marsupials compared to placentals. Our data confirm the idea that non

Forelimb preferences in quadrupedal marsupials and their implications for laterality evolution in mammals.

PubMed

Giljov, Andrey; Karenina, Karina; Malashichev, Yegor

2013-03-06

Acquisition of upright posture in evolution has been argued to facilitate manual laterality in primates. Owing to the high variety of postural habits marsupials can serve as a suitable model to test whether the species-typical body posture shapes forelimb preferences in non-primates or this phenomenon emerged only in the course of primate evolution. In the present study we aimed to explore manual laterality in marsupial quadrupeds and compare them with the results in the previously studied bipedal species. Forelimb preferences were assessed in captive grey short-tailed opossum (Monodelphis domestica) and sugar glider (Petaurus breviceps) in four different types of unimanual behaviour per species, which was not artificially evoked. We examined the possible effects of sex, age and task, because these factors have been reported to affect motor laterality in placental mammals. In both species the direction of forelimb preferences was strongly sex-related. Male grey short-tailed opossums showed right-forelimb preference in most of the observed unimanual behaviours, while male sugar gliders displayed only a slight, not significant rightward tendency. In contrast, females in both species exhibited consistent group-level preference of the left forelimb. We failed to reveal significant differences in manual preferences between tasks of potentially differing complexity: reaching a stable food item and catching live insects, as well as between the body support and food manipulation. No influence of subjects' age on limb preferences was found. The direction of sex-related differences in the manual preferences found in quadrupedal marsupials seems to be not typical for placental mammals. We suggest that the alternative way of interhemispheric connection in absence of corpus callosum may result in a fundamentally distinct mechanism of sex effect on limb preferences in marsupials compared to placentals. Our data confirm the idea that non-primate mammals differ from primates in

Diversity in parasitic helminths of Australasian marsupials and monotremes: a molecular perspective.

PubMed

Beveridge, Ian; Gasser, Robin B

2014-10-15

Marsupials and monotremes are a prominent part of the mammalian fauna in Australia, and harbour an extremely diverse and highly distinctive array of helminth parasites. Their study has been relatively neglected, likely because they have no direct, adverse socioeconomic impact. As the body plans of helminths generally are very simple and morphological characterisation likely underestimates true diversity, molecular tools have been employed to assess genetic diversity. Using biochemical and/or molecular methods, recent studies show extensive diversity in helminths of marsupials, with cryptic species being commonly encountered. The purpose of this article is to review current knowledge about the diversity of parasitic helminths of marsupials and monotremes, to raise questions as to whether current molecular data can be used to estimate diversity, what mechanisms lead to such diversity, to critically appraise the molecular tools that have been employed thus far to explore diversity and to discuss the directions which might be taken in the future employing improved techniques. Copyright © 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Promoter-Specific Expression and Imprint Status of Marsupial IGF2

PubMed Central

Stringer, Jessica M.; Suzuki, Shunsuke; Pask, Andrew J.; Shaw, Geoff; Renfree, Marilyn B.

2012-01-01

In mice and humans, IGF2 has multiple promoters to maintain its complex tissue- and developmental stage-specific imprinting and expression. IGF2 is also imprinted in marsupials, but little is known about its promoter region. In this study, three IGF2 transcripts were isolated from placental and liver samples of the tammar wallaby, Macropus eugenii. Each transcript contained a unique 5' untranslated region, orthologous to the non-coding exons derived from promoters P1–P3 in the human and mouse IGF2 locus. The expression of tammar IGF2 was predominantly from the P2 promoter, similar to humans. Expression of IGF2 was higher in pouch young than in the adult and imprinting was highly tissue and developmental-stage specific. Interestingly, while IGF2 was expressed throughout the placenta, imprinting seemed to be restricted to the vascular, trilaminar region. In addition, IGF2 was monoallelically expressed in the adult mammary gland while in the liver it switched from monoalleleic expression in the pouch young to biallelic in the adult. These data suggest a complex mode of IGF2 regulation in marsupials as seen in eutherian mammals. The conservation of the IGF2 promoters suggests they originated before the divergence of marsupials and eutherians, and have been selectively maintained for at least 160 million years. PMID:22848567

Uterine molecular changes for non-invasive embryonic attachment in the marsupials Macropus eugenii (Macropodidae) and Trichosurus vulpecula (Phalangeridae).

PubMed

Laird, Melanie K; Dargan, Jessica R; Paterson, Lillian; Murphy, Christopher R; McAllan, Bronwyn M; Shaw, Geoff; Renfree, Marilyn B; Thompson, Michael B

2017-10-01

Pregnancy in mammals requires remodeling of the uterus to become receptive to the implanting embryo. Remarkably similar morphological changes to the uterine epithelium occur in both eutherian and marsupial mammals, irrespective of placental type. Nevertheless, molecular differences in uterine remodeling indicate that the marsupial uterus employs maternal defences, including molecular reinforcement of the uterine epithelium, to regulate embryonic invasion. Non-invasive (epitheliochorial) embryonic attachment in marsupials likely evolved secondarily from invasive attachment, so uterine defences in these species may prevent embryonic invasion. We tested this hypothesis by identifying localization patterns of Talin, a key basal anchoring molecule, in the uterine epithelium during pregnancy in the tammar wallaby (Macropus eugenii; Macropodidae) and the brush tail possum (Trichosurus vulpecula; Phalangeridae). Embryonic attachment is non-invasive in both species, yet Talin undergoes a clear distributional change during pregnancy in M. eugenii, including recruitment to the base of the uterine epithelium just before attachment, that closely resembles that of invasive implantation in the marsupial species Sminthopsis crassicaudata. Basal localization occurs throughout pregnancy in T. vulpecula, although, as for M. eugenii, this pattern is most specific prior to attachment. Such molecular reinforcement of the uterine epithelium for non-invasive embryonic attachment in marsupials supports the hypothesis that less-invasive and non-invasive embryonic attachment in marsupials may have evolved via accrual of maternal defences. Recruitment of basal molecules, including Talin, to the uterine epithelium may have played a key role in this transition. © 2017 Wiley Periodicals, Inc.

Evolutionary Histories of Transposable Elements in the Genome of the Largest Living Marsupial Carnivore, the Tasmanian Devil

PubMed Central

Gallus, Susanne; Hallström, Björn M; Kumar, Vikas; Dodt, William G; Janke, Axel; Schumann, Gerald G; Nilsson, Maria A

2015-01-01

The largest living carnivorous marsupial, the Tasmanian devil (Sarcophilus harrisii), is the sole survivor of a lineage originating about 12 Ma. We set out to investigate the spectrum of transposable elements found in the Tasmanian devil genome, the first high-coverage genome of an Australian marsupial. Marsupial genomes have been shown to have the highest amount of transposable elements among vertebrates. We analyzed the horizontally transmitted DNA transposons OC1 and hAT-1_MEu in the Tasmanian devil genome. OC1 is present in all carnivorous marsupials, while having a very limited distribution among the remaining Australian marsupial orders. In contrast, hAT-1_MEu is present in all Australian marsupial orders, and has so far only been identified in a few placental mammals. We screened 158 introns for phylogenetically informative retrotransposons in the order Dasyuromorphia, and found that the youngest SINE (Short INterspersed Element), WSINE1, is no longer active in the subfamily Dasyuridae. The lack of detectable WSINE1 activity in this group may be due to a retrotransposon inactivation event approximately 30 Ma. We found that the Tasmanian devil genome contains a relatively low number of continuous full-length LINE-1 (Long INterspersed Element 1, L1) retrotransposons compared with the opossum genome. Furthermore, all L1 elements in the Tasmanian devil appeared to be nonfunctional. Hidden Markov Model approaches suggested that other potential sources of functional reverse transcriptase are absent from the genome. We discuss the issues associated with assembling long, highly similar L1 copies from short read Illumina data and describe how assembly artifacts can potentially lead to erroneous conclusions. PMID:25633377

Bandicoot fossils and DNA elucidate lineage antiquity amongst xeric-adapted Australasian marsupials

NASA Astrophysics Data System (ADS)

Kear, Benjamin P.; Aplin, Ken P.; Westerman, Michael

2016-11-01

Bandicoots (Peramelemorphia) are a unique order of Australasian marsupials whose sparse fossil record has been used as prima facie evidence for climate change coincident faunal turnover. In particular, the hypothesized replacement of ancient rainforest-dwelling extinct lineages by antecedents of xeric-tolerant extant taxa during the late Miocene (~10 Ma) has been advocated as a broader pattern evident amongst other marsupial clades. Problematically, however, this is in persistent conflict with DNA phylogenies. We therefore determine the pattern and timing of bandicoot evolution using the first combined morphological + DNA sequence dataset of Peramelemorphia. In addition, we document a remarkably archaic new fossil peramelemorphian taxon that inhabited a latest Quaternary mosaic savannah-riparian forest ecosystem on the Aru Islands of Eastern Indonesia. Our phylogenetic analyses reveal that unsuspected dental homoplasy and the detrimental effects of missing data collectively obscure stem bandicoot relationships. Nevertheless, recalibrated molecular clocks and multiple ancestral area optimizations unanimously infer an early diversification of modern xeric-adapted forms. These probably originated during the late Palaeogene (30-40 Ma) alongside progenitors of other desert marsupials, and thus occupied seasonally dry heterogenous habitats long before the onset of late Neogene aridity.

Bandicoot fossils and DNA elucidate lineage antiquity amongst xeric-adapted Australasian marsupials.

PubMed

Kear, Benjamin P; Aplin, Ken P; Westerman, Michael

2016-11-24

Bandicoots (Peramelemorphia) are a unique order of Australasian marsupials whose sparse fossil record has been used as prima facie evidence for climate change coincident faunal turnover. In particular, the hypothesized replacement of ancient rainforest-dwelling extinct lineages by antecedents of xeric-tolerant extant taxa during the late Miocene (~10 Ma) has been advocated as a broader pattern evident amongst other marsupial clades. Problematically, however, this is in persistent conflict with DNA phylogenies. We therefore determine the pattern and timing of bandicoot evolution using the first combined morphological + DNA sequence dataset of Peramelemorphia. In addition, we document a remarkably archaic new fossil peramelemorphian taxon that inhabited a latest Quaternary mosaic savannah-riparian forest ecosystem on the Aru Islands of Eastern Indonesia. Our phylogenetic analyses reveal that unsuspected dental homoplasy and the detrimental effects of missing data collectively obscure stem bandicoot relationships. Nevertheless, recalibrated molecular clocks and multiple ancestral area optimizations unanimously infer an early diversification of modern xeric-adapted forms. These probably originated during the late Palaeogene (30-40 Ma) alongside progenitors of other desert marsupials, and thus occupied seasonally dry heterogenous habitats long before the onset of late Neogene aridity.

Two-stage treatment protocol of keratocystic odontogenic tumour in young patients with Gorlin-Goltz syndrome: marsupialization and later enucleation with peripheral ostectomy. A 5-year-follow-up experience.

PubMed

Borgonovo, Andrea Enrico; Di Lascia, Stefano; Grossi, Giovanni; Maiorana, Carlo

2011-12-01

Keratocystic odontogenic tumour (KCOT) is a benign uni- or multicystic intraosseous odontogenic tumour with potential for local destruction and tendency for multiplicity, especially when associated with Gorlin-Goltz syndrome. We suggest a conservative surgical treatment based on marsupialization and later enucleation with peripheral ostectomy in order to preserve jaw's integrity in young patients. Three young patients affected of nevoid basal cell carcinoma syndrome (NBCCS or Gorlin-Goltz syndrome) presented large and multiple KCOTs, which have been treated following a two-stage surgical strategy. Initially marsupialization was performed and after a mean period of 10 months, contextually to evident reduction in radiological size image, enucleation with peripheral ostectomy was carried out. All the patients showed high collaboration in daily self-irrigation of the stomia with chlorhexidine 0.2% during the period of marsupialization. Definitive surgical intervention led to complete healing and no signs of recurrence have been observed during a 5-year-follow-up. The main advantage of this modality is the preservation of important anatomical structures involved in the lesion and jaw's continuity. Therefore in a selected group of cooperative patients, especially those affected of Gorlin-Goltz syndrome, the surgical protocol exposed allows for a less invasive approach with excellent results avoiding extensive disfiguring procedures. Copyright © 2011. Published by Elsevier Ireland Ltd.

Active vibrissal sensing in rodents and marsupials

PubMed Central

Mitchinson, Ben; Grant, Robyn A.; Arkley, Kendra; Rankov, Vladan; Perkon, Igor; Prescott, Tony J.

2011-01-01

In rats, the long facial whiskers (mystacial macrovibrissae) are repetitively and rapidly swept back and forth during exploration in a behaviour known as ‘whisking’. In this paper, we summarize previous evidence from rats, and present new data for rat, mouse and the marsupial grey short-tailed opossum (Monodelphis domestica) showing that whisking in all three species is actively controlled both with respect to movement of the animal's body and relative to environmental structure. Using automatic whisker tracking, and Fourier analysis, we first show that the whisking motion of the mystacial vibrissae, in the horizontal plane, can be approximated as a blend of two sinusoids at the fundamental frequency (mean 8.5, 11.3 and 7.3 Hz in rat, mouse and opossum, respectively) and its second harmonic. The oscillation at the second harmonic is particularly strong in mouse (around 22 Hz) consistent with previous reports of fast whisking in that species. In all three species, we found evidence of asymmetric whisking during head turning and following unilateral object contacts consistent with active control of whisker movement. We propose that the presence of active vibrissal touch in both rodents and marsupials suggests that this behavioural capacity emerged at an early stage in the evolution of therian mammals. PMID:21969685

Basking and torpor in a rock-dwelling desert marsupial: survival strategies in a resource-poor environment.

PubMed

Geiser, Fritz; Pavey, Chris R

2007-11-01

Australian deserts are characterized by unpredictability, low primary productivity, and high temperature fluctuations. Despite these adverse conditions the diversity of small insectivorous marsupials of the family Dasyuridae is surprisingly high. We quantified the thermal biology of the dasyurid Pseudantechinus madonnellensis (body mass approximately 30 g) in the wild to gain some understanding of whether the success of dasyurids in the arid zone may be related to some extent to their use of energy conservation strategies. In winter, most free-ranging Pseudantechinus frequently (58.3% of 131 animal days) entered daily torpor after midnight (mean 0157 hours) in rock crevices when outside ambient temperatures (T (a)) were low. Most animals remained torpid until the next morning when they moved while still torpid from rock crevices to sun-exposed basking sites. We visually observed basking during rewarming from torpor (mean commencement at 0943 hours) at body temperatures (T (b)) as low as 19.3 degrees C when radiant heat was high and T (a) was rising. Basking continued for the rest of the day. Torpor use was not strongly correlated with T (a), but the temporal organization of daily torpor and activity were apparently linked to the thermal characteristics of basking sites. Our study suggests that by frequently employing daily torpor and basking and by appropriately coordinating their thermal biology with that of specific locations in their environment, Pseudantechinus can reduce daily energy expenditure and thus can live and reproduce in a challenging environment. It is likely that the success of other small dasyurids and perhaps many other small mammals living in deserts is linked to employment of torpor and basking for energy conservation.

Rotavirus infection in wild marsupials (Didelphis marsupialis) of the Amazon region.

PubMed

Linhares, A C; Pereira, J D; Nakauth, C M; Gabbay, Y B

1986-01-01

Rotavirus was detected by enzyme-linked immunosorbent assay in faecal specimens collected from two (1.35%) of 148 marsupials trapped in the Amazon jungle environment. The positive samples were both from the "common opossum", Didelphis marsupialis. No infections were found in the stools of 198 animals belonging to other mammalian species: the latter included small rodents, chiropterans and primates. Electron microscopic examination of one (MA 5928) rotavirus-positive specimen showed a large number of empty particles. However, both rotavirus strains grew when inoculated in MA 104 cells (foetal Rhesus monkey kidney cells) producing clear cytopathogenic effect; indirect immunofluorescence technique of these cells showed a typical granular cytoplasmic fluorescence. The electrophoretic profile of strain MA 5928 showed a high grade of homology with that of SA 11, but also showed minor differences.

Prevalence and Clinical Significance of Herpesvirus Infection in Populations of Australian Marsupials.

PubMed

Stalder, Kathryn; Vaz, Paola K; Gilkerson, James R; Baker, Rupert; Whiteley, Pam; Ficorilli, Nino; Tatarczuch, Liliana; Portas, Timothy; Skogvold, Kim; Anderson, Garry A; Devlin, Joanne M

2015-01-01

Herpesviruses have been reported in several marsupial species, but molecular classification has been limited to four herpesviruses in macropodids, a gammaherpesvirus in two antechinus species (Antechinus flavipes and Antechinus agilis), a gammaherpesvirus in a potoroid, the eastern bettong (Bettongia gaimardi) and two gammaherpesviruses in koalas (Phascolarctos cinereus). In this study we examined a range of Australian marsupials for the presence of herpesviruses using molecular and serological techniques, and also assessed risk factors associated with herpesvirus infection. Our study population included 99 koalas (Phascolarctos cinereus), 96 eastern grey kangaroos (Macropus giganteus), 50 Tasmanian devils (Sarcophilus harrisii) and 33 common wombats (Vombatus ursinius). In total, six novel herpesviruses (one alphaherpesvirus and five gammaherpesviruses) were identified in various host species. The overall prevalence of detection of herpesvirus DNA in our study population was 27.2% (95% confidence interval (CI) of 22.6-32.2%), but this varied between species and reached as high as 45.4% (95% CI 28.1-63.7%) in common wombats. Serum antibodies to two closely related macropodid herpesviruses (macropodid herpesvirus 1 and 2) were detected in 44.3% (95% CI 33.1-55.9%) of animals tested. This also varied between species and was as high as 92% (95% CI 74.0-99.0%) in eastern grey kangaroos. A number of epidemiological variables were identified as positive predictors for the presence of herpesvirus DNA in the marsupial samples evaluated. The most striking association was observed in koalas, where the presence of Chlamydia pecorum DNA was strongly associated with the presence of herpesvirus DNA (Odds Ratio = 60, 95% CI 12.1-297.8). Our results demonstrate the common presence of herpesviruses in Australian marsupials and provide directions for future research.

Prevalence and Clinical Significance of Herpesvirus Infection in Populations of Australian Marsupials

PubMed Central

Stalder, Kathryn; Vaz, Paola K.; Gilkerson, James R.; Baker, Rupert; Whiteley, Pam; Ficorilli, Nino; Tatarczuch, Liliana; Portas, Timothy; Skogvold, Kim; Anderson, Garry A.; Devlin, Joanne M.

2015-01-01

Herpesviruses have been reported in several marsupial species, but molecular classification has been limited to four herpesviruses in macropodids, a gammaherpesvirus in two antechinus species (Antechinus flavipes and Antechinus agilis), a gammaherpesvirus in a potoroid, the eastern bettong (Bettongia gaimardi) and two gammaherpesviruses in koalas (Phascolarctos cinereus). In this study we examined a range of Australian marsupials for the presence of herpesviruses using molecular and serological techniques, and also assessed risk factors associated with herpesvirus infection. Our study population included 99 koalas (Phascolarctos cinereus), 96 eastern grey kangaroos (Macropus giganteus), 50 Tasmanian devils (Sarcophilus harrisii) and 33 common wombats (Vombatus ursinius). In total, six novel herpesviruses (one alphaherpesvirus and five gammaherpesviruses) were identified in various host species. The overall prevalence of detection of herpesvirus DNA in our study population was 27.2% (95% confidence interval (CI) of 22.6–32.2%), but this varied between species and reached as high as 45.4% (95% CI 28.1–63.7%) in common wombats. Serum antibodies to two closely related macropodid herpesviruses (macropodid herpesvirus 1 and 2) were detected in 44.3% (95% CI 33.1–55.9%) of animals tested. This also varied between species and was as high as 92% (95% CI 74.0–99.0%) in eastern grey kangaroos. A number of epidemiological variables were identified as positive predictors for the presence of herpesvirus DNA in the marsupial samples evaluated. The most striking association was observed in koalas, where the presence of Chlamydia pecorum DNA was strongly associated with the presence of herpesvirus DNA (Odds Ratio = 60, 95% CI 12.1–297.8). Our results demonstrate the common presence of herpesviruses in Australian marsupials and provide directions for future research. PMID:26222660

Germline viral "fossils" guide in silico reconstruction of a mid-Cenozoic era marsupial adeno-associated virus.

PubMed

Smith, Richard H; Hallwirth, Claus V; Westerman, Michael; Hetherington, Nicola A; Tseng, Yu-Shan; Cecchini, Sylvain; Virag, Tamas; Ziegler, Mona-Larissa; Rogozin, Igor B; Koonin, Eugene V; Agbandje-McKenna, Mavis; Kotin, Robert M; Alexander, Ian E

2016-07-05

Germline endogenous viral elements (EVEs) genetically preserve viral nucleotide sequences useful to the study of viral evolution, gene mutation, and the phylogenetic relationships among host organisms. Here, we describe a lineage-specific, adeno-associated virus (AAV)-derived endogenous viral element (mAAV-EVE1) found within the germline of numerous closely related marsupial species. Molecular screening of a marsupial DNA panel indicated that mAAV-EVE1 occurs specifically within the marsupial suborder Macropodiformes (present-day kangaroos, wallabies, and related macropodoids), to the exclusion of other Diprotodontian lineages. Orthologous mAAV-EVE1 locus sequences from sixteen macropodoid species, representing a speciation history spanning an estimated 30 million years, facilitated compilation of an inferred ancestral sequence that recapitulates the genome of an ancient marsupial AAV that circulated among Australian metatherian fauna sometime during the late Eocene to early Oligocene. In silico gene reconstruction and molecular modelling indicate remarkable conservation of viral structure over a geologic timescale. Characterisation of AAV-EVE loci among disparate species affords insight into AAV evolution and, in the case of macropodoid species, may offer an additional genetic basis for assignment of phylogenetic relationships among the Macropodoidea. From an applied perspective, the identified AAV "fossils" provide novel capsid sequences for use in translational research and clinical applications.

Females Choose Mates Based on Genetic Relatedness in a Small Dasyurid Marsupial, the Agile Antechinus (Antechinus agilis)

PubMed Central

Parrott, Marissa L.; Ward, Simon J.; Temple-Smith, Peter D.; Selwood, Lynne

2015-01-01

Females in a variety of taxa mate with more than one male during a single oestrus and exhibit mate preferences for genetically compatible males, but the influence of female mate choice on siring success is not clearly understood. Whether females choose to mate with more than one male or endure forced copulations is also often unknown. Here, we examined the effects of genetic relatedness on female mate choice and siring success in a small semelparous carnivorous marsupial, the agile antechinus (Antechinus agilis), during two consecutive breeding seasons. Experimental trials were conducted in captivity over periods of 72 hours using interconnected enclosures in which female antechinus could choose to access any of four separated males, but males were only able to access females that entered their quarters. Females had access to two genetically similar and two genetically dissimilar males simultaneously and all behavioural interactions were observed and scored from continuous video recordings. Genetic similarity between mates and paternity of young was determined by microsatellite analyses. Some females chose to enter and mate with more than one male during a single oestrus period. Although females investigated all males, they spent significantly more time visiting, and mated more times with, genetically dissimilar males. Males that were genetically dissimilar to the female sired 88% of subsequent offspring. Whilst males mated readily with most females, they rejected the advances of some receptive females, indicating a previously unexpected level of male mate choice. The results show that genetic relatedness between mates has a significant influence on mate choice, breeding and siring success in the agile antechinus. PMID:25923325

Females Choose Mates Based on Genetic Relatedness in a Small Dasyurid Marsupial, the Agile Antechinus (Antechinus agilis).

PubMed

Parrott, Marissa L; Ward, Simon J; Temple-Smith, Peter D; Selwood, Lynne

2015-01-01

Females in a variety of taxa mate with more than one male during a single oestrus and exhibit mate preferences for genetically compatible males, but the influence of female mate choice on siring success is not clearly understood. Whether females choose to mate with more than one male or endure forced copulations is also often unknown. Here, we examined the effects of genetic relatedness on female mate choice and siring success in a small semelparous carnivorous marsupial, the agile antechinus (Antechinus agilis), during two consecutive breeding seasons. Experimental trials were conducted in captivity over periods of 72 hours using interconnected enclosures in which female antechinus could choose to access any of four separated males, but males were only able to access females that entered their quarters. Females had access to two genetically similar and two genetically dissimilar males simultaneously and all behavioural interactions were observed and scored from continuous video recordings. Genetic similarity between mates and paternity of young was determined by microsatellite analyses. Some females chose to enter and mate with more than one male during a single oestrus period. Although females investigated all males, they spent significantly more time visiting, and mated more times with, genetically dissimilar males. Males that were genetically dissimilar to the female sired 88% of subsequent offspring. Whilst males mated readily with most females, they rejected the advances of some receptive females, indicating a previously unexpected level of male mate choice. The results show that genetic relatedness between mates has a significant influence on mate choice, breeding and siring success in the agile antechinus.

Transcriptomic Changes Associated with Pregnancy in a Marsupial, the Gray Short-Tailed Opossum Monodelphis domestica

PubMed Central

Hansen, Victoria Leigh; Schilkey, Faye Dorothy; Miller, Robert David

2016-01-01

Live birth has emerged as a reproductive strategy many times across vertebrate evolution; however, mammals account for the majority of viviparous vertebrates. Marsupials are a mammalian lineage that last shared a common ancestor with eutherians (placental mammals) over 148 million years ago. Marsupials are noted for giving birth to highly altricial young after a short gestation, and represent humans’ most distant viviparous mammalian relatives. Here we ask what insight can be gained into the evolution of viviparity in mammals specifically and vertebrates in general by analyzing the global uterine transcriptome in a marsupial. Transcriptome analyses were performed using NextGen sequencing of uterine RNA samples from the gray short-tailed opossum, Monodelphis domestica. Samples were collected from late stage pregnant, virgin, and non-pregnant experienced breeders. Three different algorithms were used to determine differential expression, and results were confirmed by quantitative PCR. Over 900 opossum gene transcripts were found to be significantly more abundant in the pregnant uterus than non-pregnant, and over 1400 less so. Most with increased abundance were genes related to metabolism, immune systems processes, and transport. This is the first study to characterize the transcriptomic differences between pregnant, non-pregnant breeders, and virgin marsupial uteruses and helps to establish a set of pregnancy-associated genes in the opossum. These observations allowed for comparative analyses of the differentially transcribed genes with other mammalian and non-mammalian viviparous species, revealing similarities in pregnancy related gene expression over 300 million years of amniote evolution. PMID:27598793

Desert hedgehog is a mammal-specific gene expressed during testicular and ovarian development in a marsupial.

PubMed

O'Hara, William A; Azar, Walid J; Behringer, Richard R; Renfree, Marilyn B; Pask, Andrew J

2011-12-01

Desert hedgehog (DHH) belongs to the hedgehog gene family that act as secreted intercellular signal transducers. DHH is an essential morphogen for normal testicular development and function in both mice and humans but is not present in the avian lineage. Like other hedgehog proteins, DHH signals through the patched (PTCH) receptors 1 and 2. Here we examine the expression and protein distribution of DHH, PTCH1 and PTCH2 in the developing testes of a marsupial mammal (the tammar wallaby) to determine whether DHH signalling is a conserved factor in gonadal development in all therian mammals. DHH, PTCH1 and PTCH2 were present in the marsupial genome and highly conserved with their eutherian orthologues. Phylogenetic analyses indicate that DHH has recently evolved and is a mammal-specific hedgehog orthologue. The marsupial PTCH2 receptor had an additional exon (exon 21a) not annotated in eutherian PTCH2 proteins. Interestingly we found evidence of this exon in humans and show that its translation would result in a truncated protein with functions similar to PTCH1. We also show that DHH expression was not restricted to the testes during gonadal development (as in mice), but was also expressed in the developing ovary. Expression of DHH, PTCH1 and PTCH2 in the adult tammar testis and ovary was consistent with findings in the adult mouse. These data suggest that there is a highly conserved role for DHH signalling in the differentiation and function of the mammalian testis and that DHH may be necessary for marsupial ovarian development. The receptors PTCH1 and PTCH2 are highly conserved mediators of hedgehog signalling in both the developing and adult marsupial gonads. Together these findings indicate DHH is an essential therian mammal-specific morphogen in gonadal development and gametogenesis.

Functional-adaptive analysis of the hindlimb anatomy of extant marsupials and the paleobiology of the Paleocene marsupials Mayulestes ferox and Pucadelphys andinus.

PubMed

Argot, Christine

2002-07-01

This article analyzes the adaptations of the hindlimb of two Early Paleocene marsupials, Mayulestes ferox and Pucadelphys andinus. This analysis is based on detailed comparisons with various extant marsupials, both South American and Australian. In the case of the South American opossums, original myological data were collected and osteological-myological associations were related to their locomotor behavior. The use of Australian genera helped to improve the appraisal of the locomotory habits of the fossil taxa. Several features are indicative of the ability of Mayulestes to climb or walk on uneven surfaces (e.g., very mobile hip joint, astragalocalcaneal joint pattern), and some other features emphasize a relative agility (e.g., strongly everted iliac blades, morphology of the distal epiphysis of the femur, medially stabilized cruroastragalar joint). Pucadelphys exhibits a hindlimb relatively similar morphologically to that of Mayulestes, but with features indicating slightly increased agility and a terrestrial component that is more emphasized than in Mayulestes. The Tiupampa fossils were therefore more agile than most living didelphids and resembled the condition observed in living dasyurids more. These conclusions complement a previous study performed on the forelimb of these fossils. Copyright 2002 Wiley-Liss, Inc.

Patterns in the bony skull development of marsupials: high variation in onset of ossification and conserved regions of bone contact

PubMed Central

Spiekman, Stephan N. F.; Werneburg, Ingmar

2017-01-01

Development in marsupials is specialized towards an extremely short gestation and highly altricial newborns. As a result, marsupial neonates display morphological adaptations at birth related to functional constraints. However, little is known about the variability of marsupial skull development and its relation to morphological diversity. We studied bony skull development in five marsupial species. The relative timing of the onset of ossification was compared to literature data and the ossification sequence of the marsupial ancestor was reconstructed using squared-change parsimony. The high range of variation in the onset of ossification meant that no patterns could be observed that differentiate species. This finding challenges traditional studies concentrating on the onset of ossification as a marker for phylogeny or as a functional proxy. Our study presents observations on the developmental timing of cranial bone-to-bone contacts and their evolutionary implications. Although certain bone contacts display high levels of variation, connections of early and late development are quite conserved and informative. Bones that surround the oral cavity are generally the first to connect and the bones of the occipital region are among the last. We conclude that bone contact is preferable over onset of ossification for studying cranial bone development. PMID:28233826

Isolation, X location and activity of the marsupial homologue of SLC16A2, an XIST-flanking gene in eutherian mammals

PubMed Central

Wakefield, Matthew J.; Walcher, Cristina; Disteche, Christine M.; Whitehead, Siobhan; Ross, Mark; Marshall Graves, Jennifer A.

2010-01-01

X chromosome inactivation (XCI) achieves dosage compensation between males and females for most X-linked genes in eutherian mammals. It is a whole-chromosome effect under the control of the XIST locus, although some genes escape inactivation. Marsupial XCI differs from the eutherian process, implying fundamental changes in the XCI mechanism during the evolution of the two lineages. There is no direct evidence for the existence of a marsupial XIST homologue. XCI has been studied for only a handful of genes in any marsupial, and none in the model kangaroo Macropus eugenii (the tammar wallaby). We have therefore studied the sequence, location and activity of a gene SLC16A2 (solute carrier, family 16, class A, member 2) that flanks XIST on the human and mouse X chromosomes. A BAC clone containing the marsupial SLC16A2 was mapped to the end of the long arm of the tammar X chromosome and used in RNA FISH experiments to determine whether one or both loci are transcribed in female cells. In male and female cells, only a single signal was found, indicating that the marsupial SLC16A2 gene is silenced on the inactivated X. PMID:16235118

Peripheral and central auditory specialization in a gliding marsupial, the feathertail glider, Acrobates pygmaeus.

PubMed

Aitkin, L M; Nelson, J E

1989-01-01

Two specialized features are described in the auditory system of Acrobates pygmaeus, a small gliding marsupial. Firstly, the ear canal includes a transverse disk of bone that partly occludes the canal near the eardrum. The resultant narrow-necked chamber above the eardrum appears to attenuate sound across a broad frequency range, except at 27-29 kHz at which a net gain of sound pressure occurs. Secondly, the lateral medulla is hypertrophied at the level of the cochlear nucleus, forming a massive lateral lobe comprised of multipolar cells and granule cells. This lobe has connections with the auditory nerve and the cerebellum. Speculations are advanced about the functions of these structures in gliding behaviour and predator avoidance.

Heterochrony in the regulation of the developing marsupial limb.

PubMed

Chew, Keng Yih; Shaw, Geoffrey; Yu, Hongshi; Pask, Andrew J; Renfree, Marilyn B

2014-02-01

At birth, marsupial neonates have precociously developed forelimbs. The development of the tammar wallaby (Macropus eugenii) hindlimbs lags significantly behind that of the forelimbs. This differs from the grey short-tailed opossum, Monodelphis domestica, which has relatively similar fore- and hindlimbs at birth. This study examines the expression of the key patterning genes TBX4, TBX5, PITX1, FGF8, and SHH in developing limb buds in the tammar wallaby. All genes examined were highly conserved with orthologues from opossum and mouse. TBX4 expression appeared earlier in development than in the mouse, but later than in the opossum. SHH expression is restricted to the zone of polarising activity, while TBX5 (forelimb) and PITX1 (hindlimb) showed diffuse mRNA expression. FGF8 is specifically localised to the apical ectodermal ridge, which is more prominent than in the opossum. The most marked divergence in limb size in marsupials occurs in the kangaroos and wallabies. The faster development of the fore limb compared to that of the hind limb correlates with the early timing of the expression of the key patterning genes in these limbs. Copyright © 2013 Wiley Periodicals, Inc.

Morphogenesis of the fibrous sheath in the marsupial spermatozoon

PubMed Central

Ricci, M; Breed, WG

2005-01-01

The spermatozoon fibrous sheath contains longitudinal columns and circumferential ribs. It surrounds the axoneme of the principal piece of the mammalian sperm tail, and may be important in sperm stability and motility. Here we describe its assembly during spermiogenesis in a marsupial, the brush-tail possum, and compare its structural organization with that of eutherian mammals, birds and reptiles. Transmission electron microscopy showed that possum fibrous sheath assembly is a multistep process extending in a distal-to-proximal direction along the axoneme from steps 4 to 14 of spermiogenesis. For the most part, assembly of the longitudinal columns occurs before that of the circumferential ribs. Immunohistochemical and immunogold labelling showed that fibrous sheath proteins are first present in the spermatid cytoplasm; at least some of the proteins of the sheath precursors differ from those in the mature fibrous sheath. That immunoreactivity develops after initiation of chromatin condensation suggests that fibrous sheath proteins, or their mRNAs, are stored within the spermatid cytoplasmic lobule prior to their assembly along the axoneme. These findings are similar to those in laboratory rats, and thus suggests that the mode of fibrous sheath assembly evolved in a common ancestor over 125 million years ago, prior to the divergence of marsupial and eutherian lineages. PMID:16050902

Frontal Mucocele Extended Orbita and Endoscopic Marsupialization Technique.

PubMed

Erdogan, Banu Atalay; Unlu, Nazmiye; Aydin, Sedat; Avci, Hakan

2018-06-01

Mucocele is benign, slow-growing, mucous-filled cystic lesions that arise in the paranasal sinuses. It causes progressive distension of the bony walls and induces compressive symptoms. Surgical treatment of paranasal sinus mucoceles includes endoscopic approach or external approach. The authors report a patient of frontal mucocele who presented with a history of progressive unilateral protrusion. Computed tomography scan revealed a large mucocele of the frontal sinus with orbital extension on the same side. He was successfully treated with endoscopic marsupialization without any serious complications.

The interphotoreceptor retinoid binding protein gene in therian mammals: implications for higher level relationships and evidence for loss of function in the marsupial mole.

PubMed

Springer, M S; Burk, A; Kavanagh, J R; Waddell, V G; Stanhope, M J

1997-12-09

The subclass Theria of Mammalia includes marsupials (infraclass Metatheria) and placentals (infraclass Eutheria). Within each group, interordinal relationships remain unclear. One limitation of many studies is incomplete ordinal representation. Here, we analyze DNA sequences for part of exon 1 of the interphotoreceptor retinoid binding protein gene, including 10 that are newly reported, for representatives of all therian orders. Among placentals, the most robust clades are Cetartiodactyla, Paenungulata, and an expanded African clade that includes paenungulates, tubulidentates, and macroscelideans. Anagalida, Archonta, Altungulata, Hyracoidea + Perissodactyla, Ungulata, and the "flying primate" hypothesis are rejected by statistical tests. Among marsupials, the most robust clade includes all orders except Didelphimorphia. The phylogenetic placement of the monito del monte and the marsupial mole remains unclear. However, the marsupial mole sequence contains three frameshift indels and numerous stop codons in all three reading frames. Given that the interphotoreceptor retinoid binding protein gene is a single-copy gene that functions in the visual cycle and that the marsupial mole is blind with degenerate eyes, this finding suggests that phenotypic degeneration of the eyes is accompanied by parallel changes at the molecular level as a result of relaxed selective constraints.

Niche conservatism and phylogenetic clustering in a tribe of arid-adapted marsupial mice, the Sminthopsini.

PubMed

García-Navas, Vicente; Westerman, Michael

2018-05-28

The progressive expansion of the Australian arid zone during the last 20 Ma appears to have spurred the diversification of several families of plants, vertebrates and invertebrates, yet such taxonomic groups appear to show limited niche radiation. Here, we test whether speciation is associated with niche conservatism (constraints on ecological divergence) or niche divergence in a tribe of marsupial mice (Sminthopsini; 23 taxa) that includes the most speciose genus of living dasyurids, the sminthopsins. To that end, we integrated phylogenetic data with ecological niche modelling, to enable us to reconstruct the evolution of climatic suitability within Sminthopsini. Niche overlap among species was low-moderate (but generally higher than expected given environmental background similarity), and the degree of phylogenetic clustering increased with aridity. Climatic niche reconstruction illustrates that there has been little apparent evolution of climatic tolerance within clades. Accordingly, climatic disparity tends to be accumulated among clades, suggesting considerable niche conservatism. Our results also indicate that evolution of climatic tolerances has been heterogeneous across different dimensions of climate (temperature vs. precipitation) and across phylogenetic clusters (Sminthopsis murina group vs. other groups). Although some results point to the existence of shifts in climatic niches during the speciation of sminthopsins, our study provides evidence for substantial phylogenetic niche conservatism in the group. We conclude that niche diversification had a low impact on the speciation of this tribe of small, but highly mobile marsupials. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

Marsupialization of a large dentigerous cyst in the mandible with orthodontic extrusion of three impacted teeth. A case report.

PubMed

Abu-Mostafa, Nedal; Abbasi, Arshad

2017-09-01

The dentigerous cyst (DC) is the most common type of developmental odontogenic cyst. It is usually asymptomatic and associated with the crown of an unerupted or impacted tooth. However, after a long duration, it is likely to cause significant bone resorption, cortical expansion, and tooth displacement. This report presents a large infected DC in the mandible of a 12-year-old female patient. The DC was located inferior to badly decayed primary molars and surrounded three impacted permanent teeth: canine, first premolar, which had a dilacerated root, and second premolar. The DC was treated successfully by marsupialization and extrusion of the impacted teeth. In conclusion, the combination of marsupialization with orthodontic extrusion is a conservative, efficient protocol that stimulates bone healing and promotes the eruption of cyst-associated teeth even if they are deeply impacted, crowded, or have a dilacerated root. Key words: Dentigerous cyst, marsupialization, impacted teeth, orthodontic extrusion, dilacerated root.

Right attitude, right decision and timely planning in surgical pedodontics -scoop out or expose it.

PubMed

Kethineni, Balaji; Peddi, Ravigna; Puppala, Ravindar; Banavath, Sunitha; Chowdary, Uday Kumar; Raj, Deepak

2013-04-01

Radicular cysts are the most common odontogenic cystic lesions of inflammatory origin and are usually asymptomatic and are left unnoticed, until detected by routine radiography. It is managed either by surgical enucleation or marsupialization. Conventional nonsurgical endodontic treatment has a high degree of clinical success, but in certain cases surgical intervention becomes necessary. This is the case report of a patient presenting with unilateral radicular cyst. The lesion is managed by marsupialization using a novel and safe method of separating the soft tissue mass of the periapical lesion which was in proximity to vital and vulnerable anatomical tissue, emphasizing the need of application of treatment in the best interest of patients. The treatment of choice is dependent on the size and localization of the lesion, the bone integrity of the lesions wall and its proximity to vital structure. This case report of radicular cysts emphasis on the advantages and disadvantages of the leading criteria that should be taken into consideration when assessing the treatment modalities for radicular cyst. Odontogenic cysts, Radicular cyst, Marsupialization, Enucleation. How to cite this article: Kethineni B, Peddi R, Puppala R, Sunitha B, Chowdary U K, Raj D. Right Attitude, Right Decision and Timely Planning in Surgical Pedodontics -Scoop Out or Expose It. J Int Oral Health 2013; 5(2):50-54.

Diet overlap and spatial segregation between two neotropical marsupials revealed by multiple analytical approaches

PubMed Central

Romero, Gustavo Quevedo; Linhares, Arício Xavier; Vizentin-Bugoni, Jeferson; Porto, Erica Aline Correa; Setz, Eleonore Zulnara Freire

2017-01-01

Species co-existence depends on how organisms utilize their environment and resources. When two sympatric species are similar in some ecological requirements, their coexistence may arise from differences in resource use over time and/or space. Interactions among coexisting marsupials remain poorly understood, especially in the Neotropics. Here we combine spatial niche measurements, individual-resource networks, and isotopic niche approaches, to investigate the ecological strategies used by the Neotropical marsupials Didelphis aurita and Metachirus nudicaudatus to co-occur in an area of Serra do Mar State Park (southeast of Brazil). Both individual-resource networks and isotopic niche approaches indicate similar patterns of omnivory for both species. Isotopic analysis showed the species’ trophic niche to be similar, with 52% of overlap, and no differences between proportional contributions of each resource to their diets. Moreover, individual-resource network analysis found no evidence of diet nestedness or segregation. The trophic niche overlap observed was associated with spatial segregation between species. Despite using the same area over the year, D. aurita and M. nudicaudatus exhibited spatial segregation among seasons. These results illustrate that the detection of spatial segregation is scale-dependent and must be carefully considered. In conclusion, our findings provide a new perspective on the ecology of these two Neotropical marsupials by illustrating how the association of distinct but complementary methods can be applied to reach a more complete understanding of resource partitioning and species coexistence. PMID:28704561

Imidacloprid treatment of marsupials for fleas (Pygiopsylla hoplia).

PubMed

Baker, R T; Beveridge, I

2001-09-01

Two eastern barred bandicoots (Perameles gunnii), two eastern quells (Dasyunrus viverrinus), four fat-tailed dunnarts (Sminthopsis crassicaudata), a Leadbeater's possum (Gymnobelideus leadbeateri), a yellow-bellied glider (Petaurus australis), and a ring-tailed possum (Pseudocheirus peregrinus) were treated with imidacloprid (10.7 +/- 0.6 mg/kg topically, minimum dose 0.5 mg) after observation of fleas (Pygiopsylla hoplia) on animals and in their nest boxes. No live fleas or adverse reactions to imidacloprid were observed for 27 days following treatment. The ease of application, absence of toxicity, and long residual effect makes imidacloprid a useful drug for treating flea infestations in these marsupials.

Effects of hypothyroidism on myosin heavy chain composition and fibre types of fast skeletal muscles in a small marsupial, Antechinus flavipes.

PubMed

Zhong, Wendy W H; Withers, Kerry W; Hoh, Joseph F Y

2010-04-01

Effects of drug-induced hypothyroidism on myosin heavy chain (MyHC) content and fibre types of fast skeletal muscles were studied in a small marsupial, Antechinus flavipes. SDS-PAGE of MyHCs from the tibialis anterior and gastrocnemius revealed four isoforms, 2B, 2X, 2A and slow, in that order of decreasing abundance. After 5 weeks treatment with methimazole, the functionally fastest 2B MyHC significantly decreased, while 2X, 2A and slow MyHCs increased. Immunohistochemistry using monospecific antibodies to each of the four MyHCs revealed decreased 2b and 2x fibres, and increased 2a and hybrid fibres co-expressing two or three MyHCs. In the normally homogeneously fast superficial regions of these muscles, evenly distributed slow-staining fibres appeared, resembling the distribution of slow primary myotubes in fast muscles during development. Hybrid fibres containing 2A and slow MyHCs were virtually absent. These results are more detailed but broadly similar to the earlier studies on eutherians. We hypothesize that hypothyroidism essentially reverses the effects of thyroid hormone on MyHC gene expression of muscle fibres during myogenesis, which differ according to the developmental origin of the fibre: it induces slow MyHC expression in 2b fibres derived from fast primary myotubes, and shifts fast MyHC expression in fibres of secondary origin towards 2A, but not slow, MyHC.

CERRADO SMALL MAMMALS: a dataset of abundance and distribution of marsupials, lagomorphs, and rodents in a neotropical savanna.

PubMed

Mendonça, André F; Percequillo, Alexandre R; de Camargo, Nicholas F; Ribeiro, Juliana F; Palma, Alexandre R T; Oliveira, Leonardo C; Câmara, Edeltrudes M V C; Vieira, Emerson M

2018-04-27

Patterns in distribution and local abundance of species within a biome are central concerns in ecology and allow the understanding of the effects of habitat loss on rates of species extinction; provide support for the creation and management of reserves; and contribute to the identification and quantification of the processes that allow niche partitioning by species. However, despite the importance in the conservation and management of the ecosystems, most systematized information on the abundance and distribution of small mammals is restricted to the northern hemisphere or forest ecosystems. For tropical biomes, an important part of this information remains dispersed and difficult to access in the form of theses, technical reports or unpublished datasets. Here we present a comprehensive dataset of abundance and richness of small mammals in the Cerrado, the largest Neotropical savanna. This dataset includes 2,599 records of 446 sites from 96 studies. Despite of more than 50% of references in this dataset are peer-reviewed journal articles, 45.78% of communities were compiled from theses. The dataset comprises 24,283 individuals of 55 genera and at least 118 species of small mammals including 29 marsupials, two lagomorphs (one exotic) and 87 rodents (three exotic). Local species richness ranged from one to 26 species (5.82 ±3.55, average species richness ±SD). We observed hyper-dominance of a few species; the 10 most abundant species in this dataset represented 60.19% of all recorded individuals. The hairy-tailed bolo mouse (Necromys lasiurus) represented over than 20% of all individuals and occurred at more than 50% of sites. Furthermore, we identified 18 environments, 16 native vegetation types, and two anthropic environments. Typical savanna and gallery forest were the most frequently sampled vegetation types (comprising 46.94% of all sampled sites) and the most speciose ones (57 species for typical savanna and 53 species for gallery forest). The information

When Genomics Is Not Enough: Experimental Evidence for a Decrease in LINE-1 Activity During the Evolution of Australian Marsupials

PubMed Central

Gallus, Susanne; Lammers, Fritjof

2016-01-01

The autonomous transposable element LINE-1 is a highly abundant element that makes up between 15% and 20% of therian mammal genomes. Since their origin before the divergence of marsupials and placental mammals, LINE-1 elements have contributed actively to the genome landscape. A previous in silico screen of the Tasmanian devil genome revealed a lack of functional coding LINE-1 sequences. In this study we present the results of an in vitro analysis from a partial LINE-1 reverse transcriptase coding sequence in five marsupial species. Our experimental screen supports the in silico findings of the genome-wide degradation of LINE-1 sequences in the Tasmanian devil, and identifies a high frequency of degraded LINE-1 sequences in other Australian marsupials. The comparison between the experimentally obtained LINE-1 sequences and reference genome assemblies suggests that conclusions from in silico analyses of retrotransposition activity can be influenced by incomplete genome assemblies from short reads. PMID:27389686

Philodryas chamissonis (Reptilia: Squamata: Colubridae) preys on the arboreal marsupial Dromiciops gliroides (Mammalia: Microbiotheria: Microbiotheriidae).

PubMed

Muñoz-Leal, S; Ardiles, K; Figueroa, R A; González-Acuña, D

2013-02-01

Philodryas chamissonis, the Chilean long-tailed snake, is a diurnal predator mainly of Liolaemus lizards, but also of amphibians, birds, rodents and juvenile rabbits. Dromiciops gliroides (Colocolo opossum) is an arboreal marsupial endemic of temperate rainforest of southern South America. Little information is available about this marsupial's biology and ecology. Here we report the predation of one Colocolo opossum by an adult female P. chamissonis in a mixed Nothofagus forest, composed mainly by N. dombeyi, N. glauca and N. alpina trees, in the "Huemules de Niblinto" National Reserve, Nevados de Chillán, Chile. Since these two species have different activity and habitat use patterns, we discuss how this encounter may have occurred. Although it could just have been an opportunistic event, this finding provides insights into the different components of food chains in forest ecosystems of Chile.

Skeletal fluorosis in marsupials: A comparison of bone lesions in six species from an Australian industrial site.

PubMed

Death, Clare; Coulson, Graeme; Kierdorf, Uwe; Kierdorf, Horst; Ploeg, Richard; Firestone, Simon M; Dohoo, Ian; Hufschmid, Jasmin

2017-04-15

In this study we explored the prevalence, type, location and severity of skeletal lesions in six species of Australian marsupial (Macropus giganteus, Notamacropus rufogriseus, Wallabia bicolor, Phascolarctos cinereus, Trichosurus vulpecula and Pseudocheirus peregrinus) from high and low-fluoride environments. Lesions occurred to varying extents in all species, and lesion distribution varied with biomechanical differences in gait and mastication. Bone fluoride levels increased with severity of periosteal hyperostosis. The mean bone fluoride concentration of individuals lacking hyperostosis (across all species, from both high and low-fluoride environments) was 1100±260μgF - /g dry bone, compared to 4300±1200μgF - /g and 6300±1200μgF - /g in those with mild and severe grade hyperostosis, respectively. Multivariable modelling showed that the probability of observing a lesion varied across species, anatomical location, age and bone fluoride concentration (in a non-linear manner). The pathological changes reported in the marsupials are consistent with the range of fluoride-related lesions described in other mammals, and biomechanical differences among the studied marsupial species offer some explanation for the degree of interspecific variability in prevalence, type, anatomical location, and severity of the lesions. Copyright © 2017 Elsevier B.V. All rights reserved.

Distribution of keratin and associated proteins in the epidermis of monotreme, marsupial, and placental mammals.

PubMed

Alibardi, Lorenzo; Maderson, Paul F A

2003-10-01

The expression of acidic and basic keratins, and of some keratinization marker proteins such as filaggrin, loricrin, involucrin, and trichohyalin, is known for the epidermis of only a few eutherian species. Using light and high-resolution immunocytochemistry, the presence of these proteins has been studied in two monotreme and five marsupial species and compared to that in eutherians. In both monotreme and marsupial epidermis lamellar bodies occur in the upper spinosus and granular layers. Development of the granular layer varies between species and regionally within species. There is great interspecific variation in the size (0.1-3.0 microm) of keratohyalin granules (KHGs) associated with production of orthokeratotic corneous tissues. Those skin regions lacking hairs (platypus web), or showing reduced pelage density (wombat) have, respectively, minute or indiscernible KHGs, associated with patchy, or total, parakeratosis. Ultrastructural analysis shows that monotreme and marsupial KHGs comprise irregular coarse filaments of 25-40 nm that contact keratin filaments. Except for parakeratotic tissues of platypus web, distribution of acidic and basic proteins in monotreme and marsupial epidermis as revealed by anti-keratin antibodies AE1, AE2, and AE3 resembles that of eutherian epidermis. Antibodies against human or rat filaggrins have little or no cross-reactivity with epidermal proteins of other mammals: only sparse areas of wombat and rabbit epidermis show a weak immunofluorescence in transitional cells and in the deepest corneous tissues. Of the available, eutherian-derived antibodies, that against involucrin shows no cross-reactivity with any monotreme and marsupial epidermal tissues and that against trichohyalin cross-reacts only with cells in the inner root sheath and medulla of hairs. These results suggest that if involucrin and trichohyalin are present throughout noneutherian epidermis, they may have species-specific molecular structures. By contrast

Coping with chaos: unpredictable food supplies intensify torpor use in an arid-zone marsupial, the fat-tailed dunnart ( Sminthopsis crassicaudata)

NASA Astrophysics Data System (ADS)

Munn, Adam J.; Kern, Pippa; McAllan, Bronwyn M.

2010-06-01

The severity, duration and amplitude of extreme weather events are forecast to intensify with current climate trends, over both long (e.g. seasonal) and short (e.g. daily) time-scales. As such, the predictability of food supplies for many small endotherms is likely to become increasingly important. Numerous small mammals and birds combat food shortages using torpor, a controlled reduction in metabolic rate and body temperature that helps lower their daily energy requirements. As such, torpor often has been cited as a key feature allowing some small endotherms to survive highly unpredictable climates, such as tropics or dry deserts, but mensurative demonstrations of this are lacking. We have shown here that when a small desert marsupial, the fat-tailed dunnart ( Sminthopsis crassicaudata), is offered unpredictable levels of daily food, they increase frequency of daily torpor and length of bouts compared with animals offered ad libitum food, but this was not found for animals offered a 70% food-restricted diet. Our data suggest that simple food restriction may not be sufficient for evaluating the efficacy of torpor as a strategy for managing unpredictable climates.

Transcriptomic changes in the pre-implantation uterus highlight histotrophic nutrition of the developing marsupial embryo.

PubMed

Whittington, Camilla M; O'Meally, Denis; Laird, Melanie K; Belov, Katherine; Thompson, Michael B; McAllan, Bronwyn M

2018-02-05

Early pregnancy is a critical time for successful reproduction; up to half of human pregnancies fail before the development of the definitive chorioallantoic placenta. Unlike the situation in eutherian mammals, marsupial pregnancy is characterised by a long pre-implantation period prior to the development of the short-lived placenta, making them ideal models for study of the uterine environment promoting embryonic survival pre-implantation. Here we present a transcriptomic study of pre-implantation marsupial pregnancy, and identify differentially expressed genes in the Sminthopsis crassicaudata uterus involved in metabolism and biosynthesis, transport, immunity, tissue remodelling, and uterine receptivity. Interestingly, almost one quarter of the top 50 genes that are differentially upregulated in early pregnancy are putatively involved in histotrophy, highlighting the importance of nutrient transport to the conceptus prior to the development of the placenta. This work furthers our understanding of the mechanisms underlying survival of pre-implantation embryos in the earliest live bearing ancestors of mammals.

Early cell lineage specification in a marsupial: a case for diverse mechanisms among mammals.

PubMed

Frankenberg, Stephen; Shaw, Geoff; Freyer, Claudia; Pask, Andrew J; Renfree, Marilyn B

2013-03-01

Early cell lineage specification in eutherian mammals results in the formation of a pluripotent inner cell mass (ICM) and trophoblast. By contrast, marsupials have no ICM. Here, we present the first molecular analysis of mechanisms of early cell lineage specification in a marsupial, the tammar wallaby. There was no overt differential localisation of key lineage-specific transcription factors in cleavage and early unilaminar blastocyst stages. Pluriblast cells (equivalent to the ICM) became distinguishable from trophoblast cells by differential expression of POU5F1 and, to a greater extent, POU2, a paralogue of POU5F1. Unlike in the mouse, pluriblast-trophoblast differentiation coincided with a global nuclear-to-cytoplasmic transition of CDX2 localisation. Also unlike in the mouse, Hippo pathway factors YAP and WWTR1 showed mutually distinct localisation patterns that suggest non-redundant roles. NANOG and GATA6 were conserved as markers of epiblast and hypoblast, respectively, but some differences to the mouse were found in their mode of differentiation. Our results suggest that there is considerable evolutionary plasticity in the mechanisms regulating early lineage specification in mammals.

Evolution of coding and non-coding genes in HOX clusters of a marsupial.

PubMed

Yu, Hongshi; Lindsay, James; Feng, Zhi-Ping; Frankenberg, Stephen; Hu, Yanqiu; Carone, Dawn; Shaw, Geoff; Pask, Andrew J; O'Neill, Rachel; Papenfuss, Anthony T; Renfree, Marilyn B

2012-06-18

The HOX gene clusters are thought to be highly conserved amongst mammals and other vertebrates, but the long non-coding RNAs have only been studied in detail in human and mouse. The sequencing of the kangaroo genome provides an opportunity to use comparative analyses to compare the HOX clusters of a mammal with a distinct body plan to those of other mammals. Here we report a comparative analysis of HOX gene clusters between an Australian marsupial of the kangaroo family and the eutherians. There was a strikingly high level of conservation of HOX gene sequence and structure and non-protein coding genes including the microRNAs miR-196a, miR-196b, miR-10a and miR-10b and the long non-coding RNAs HOTAIR, HOTAIRM1 and HOXA11AS that play critical roles in regulating gene expression and controlling development. By microRNA deep sequencing and comparative genomic analyses, two conserved microRNAs (miR-10a and miR-10b) were identified and one new candidate microRNA with typical hairpin precursor structure that is expressed in both fibroblasts and testes was found. The prediction of microRNA target analysis showed that several known microRNA targets, such as miR-10, miR-414 and miR-464, were found in the tammar HOX clusters. In addition, several novel and putative miRNAs were identified that originated from elsewhere in the tammar genome and that target the tammar HOXB and HOXD clusters. This study confirms that the emergence of known long non-coding RNAs in the HOX clusters clearly predate the marsupial-eutherian divergence 160 Ma ago. It also identified a new potentially functional microRNA as well as conserved miRNAs. These non-coding RNAs may participate in the regulation of HOX genes to influence the body plan of this marsupial.

Evolution of coding and non-coding genes in HOX clusters of a marsupial

PubMed Central

2012-01-01

Background The HOX gene clusters are thought to be highly conserved amongst mammals and other vertebrates, but the long non-coding RNAs have only been studied in detail in human and mouse. The sequencing of the kangaroo genome provides an opportunity to use comparative analyses to compare the HOX clusters of a mammal with a distinct body plan to those of other mammals. Results Here we report a comparative analysis of HOX gene clusters between an Australian marsupial of the kangaroo family and the eutherians. There was a strikingly high level of conservation of HOX gene sequence and structure and non-protein coding genes including the microRNAs miR-196a, miR-196b, miR-10a and miR-10b and the long non-coding RNAs HOTAIR, HOTAIRM1 and HOXA11AS that play critical roles in regulating gene expression and controlling development. By microRNA deep sequencing and comparative genomic analyses, two conserved microRNAs (miR-10a and miR-10b) were identified and one new candidate microRNA with typical hairpin precursor structure that is expressed in both fibroblasts and testes was found. The prediction of microRNA target analysis showed that several known microRNA targets, such as miR-10, miR-414 and miR-464, were found in the tammar HOX clusters. In addition, several novel and putative miRNAs were identified that originated from elsewhere in the tammar genome and that target the tammar HOXB and HOXD clusters. Conclusions This study confirms that the emergence of known long non-coding RNAs in the HOX clusters clearly predate the marsupial-eutherian divergence 160 Ma ago. It also identified a new potentially functional microRNA as well as conserved miRNAs. These non-coding RNAs may participate in the regulation of HOX genes to influence the body plan of this marsupial. PMID:22708672

Maturation of the growth axis in marsupials occurs gradually during post-natal life and over an equivalent developmental stage relative to eutherian species.

PubMed

Menzies, Brandon R; Shaw, Geoffrey; Fletcher, Terry P; Pask, Andrew J; Renfree, Marilyn B

2012-02-26

The separation of a nutrition-responsive insulin-like growth factor (IGF) system and a growth hormone (GH) responsive IGF system to control pre- and post-natal growth of developing mammals may originate from the constraints imposed by intra-uterine development. In eutherian species that deliver relatively precocial young, maturation of the GH regulatory system is coincident with the time of birth. We measured the hepatic expression of the four key growth axis genes GH-receptor, IGF-1 and -2, and IGFBBP-3, and plasma protein concentrations of IGF-1 from late fetal life through to adult stages of a marsupial, the tammar wallaby. The data clearly show that maturation of GH-regulated growth in marsupials occurs gradually over the course of post-natal life at an equivalent developmental stage to that of precocial eutherian mammals. This suggests that the timing of GH-regulated growth in marsupials is not related to parturition but instead to the relative developmental stage. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Trypanosomes genetic diversity, polyparasitism and the population decline of the critically endangered Australian marsupial, the brush tailed bettong or woylie (Bettongia penicillata)

PubMed Central

Botero, Adriana; Thompson, Craig K.; Peacock, Christopher S.; Clode, Peta L.; Nicholls, Philip K.; Wayne, Adrian F.; Lymbery, Alan J.; Thompson, R.C. Andrew

2013-01-01

While much is known of the impact of trypanosomes on human and livestock health, trypanosomes in wildlife, although ubiquitous, have largely been considered to be non-pathogenic. We describe the genetic diversity, tissue tropism and potential pathogenicity of trypanosomes naturally infecting Western Australian marsupials. Blood samples collected from 554 live-animals and 250 tissue samples extracted from 50 carcasses of sick-euthanized or road-killed animals, belonging to 10 species of marsupials, were screened for the presence of trypanosomes using a PCR of the 18S rDNA gene. PCR results revealed a rate of infection of 67% in blood and 60% in tissues. Inferred phylogenetic trees using 18S rDNA and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) sequences showed the presence of eight genotypes that clustered into three clades: a clade including Trypanosoma copemani, a new clade closely related to Trypanosoma gilletti, and a clade including Trypanosoma H25 from an Australian kangaroo. Trypanosome infections were compared in a declining and in a stable population of the endangered Australian marsupial, the brush tailed bettong or woylie (Bettongia penicillata). This marsupial showed high rates of infection with Clade A genotypes (96%) in the declining population, whereas in the stable population, Clade B genotypes were predominant (89%). Mixed infections were common in woylies from the declining but not from the stable population. Histopathological findings associated with either mixed or single infections involving Clade A genotypes, showed a strong inflammatory process and tissue degeneration predominantly in heart, oesophagus and tongue. Trypanosomes were successfully grown in culture and for the first time we demonstrate that a genotype within Clade A has the capacity to not only colonize different tissues in the host but also to invade cells in vitro. These results provide evidence for the potential role of trypanosomes in the decline of a formerly

Evaporative water loss, relative water economy and evaporative partitioning of a heterothermic marsupial, the monito del monte (Dromiciops gliroides).

PubMed

Withers, Philip C; Cooper, Christine E; Nespolo, Roberto F

2012-08-15

We examine here evaporative water loss, economy and partitioning at ambient temperatures from 14 to 33°C for the monito del monte (Dromiciops gliroides), a microbiotheriid marsupial found only in temperate rainforests of Chile. The monito's standard evaporative water loss (2.58 mg g(-1) h(-1) at 30°C) was typical for a marsupial of its body mass and phylogenetic position. Evaporative water loss was independent of air temperature below thermoneutrality, but enhanced evaporative water loss and hyperthermia were the primary thermal responses above the thermoneutral zone. Non-invasive partitioning of total evaporative water loss indicated that respiratory loss accounted for 59-77% of the total, with no change in respiratory loss with ambient temperature, but a small change in cutaneous loss below thermoneutrality and an increase in cutaneous loss in and above thermoneutrality. Relative water economy (metabolic water production/evaporative water loss) increased at low ambient temperatures, with a point of relative water economy of 15.4°C. Thermolability had little effect on relative water economy, but conferred substantial energy savings at low ambient temperatures. Torpor reduced total evaporative water loss to as little as 21% of normothermic values, but relative water economy during torpor was poor even at low ambient temperatures because of the relatively greater reduction in metabolic water production than in evaporative water loss. The poor water economy of the monito during torpor suggests that negative water balance may explain why hibernators periodically arouse to normothermia, to obtain water by drinking or via an improved water economy.

Automated measurement of pulmonary emphysema and small airway remodeling in cigarette smoke-exposed mice.

PubMed

Laucho-Contreras, Maria E; Taylor, Katherine L; Mahadeva, Ravi; Boukedes, Steve S; Owen, Caroline A

2015-01-16

COPD is projected to be the third most common cause of mortality world-wide by 2020((1)). Animal models of COPD are used to identify molecules that contribute to the disease process and to test the efficacy of novel therapies for COPD. Researchers use a number of models of COPD employing different species including rodents, guinea-pigs, rabbits, and dogs((2)). However, the most widely-used model is that in which mice are exposed to cigarette smoke. Mice are an especially useful species in which to model COPD because their genome can readily be manipulated to generate animals that are either deficient in, or over-express individual proteins. Studies of gene-targeted mice that have been exposed to cigarette smoke have provided valuable information about the contributions of individual molecules to different lung pathologies in COPD((3-5)). Most studies have focused on pathways involved in emphysema development which contributes to the airflow obstruction that is characteristic of COPD. However, small airway fibrosis also contributes significantly to airflow obstruction in human COPD patients((6)), but much less is known about the pathogenesis of this lesion in smoke-exposed animals. To address this knowledge gap, this protocol quantifies both emphysema development and small airway fibrosis in smoke-exposed mice. This protocol exposes mice to CS using a whole-body exposure technique, then measures respiratory mechanics in the mice, inflates the lungs of mice to a standard pressure, and fixes the lungs in formalin. The researcher then stains the lung sections with either Gill's stain to measure the mean alveolar chord length (as a readout of emphysema severity) or Masson's trichrome stain to measure deposition of extracellular matrix (ECM) proteins around small airways (as a readout of small airway fibrosis). Studies of the effects of molecular pathways on both of these lung pathologies will lead to a better understanding of the pathogenesis of COPD.

Hammer-toothed ‘marsupial skinks' from the Australian Cenozoic

PubMed Central

Arena, Derrick A.; Archer, Michael; Godthelp, Henk; Hand, Suzanne J.; Hocknull, Scott

2011-01-01

Extinct species of Malleodectes gen. nov. from Middle to Late Miocene deposits of the Riversleigh World Heritage Area, northwestern Queensland, Australia are enigmatic, highly specialized, probably snail-eating marsupials. Dentally, they closely resemble a bizarre group of living heterodont, wet forest scincid lizards from Australia (Cyclodomorphus) that may well have outcompeted them as snail-eaters when the closed forests of central Australia began to decline. Although there are scincids known from the same Miocene deposits at Riversleigh, these are relatively plesiomorphic, generalized feeders. This appears to be the most striking example known of dental convergence and possible competition between a mammal and a lizard, which in the long run worked out better for the lizards. PMID:21508033

Marsupial tammar wallaby delivers milk bioactives to altricial pouch young to support lung development.

PubMed

Modepalli, Vengamanaidu; Hinds, Lyn A; Sharp, Julie A; Lefevre, Christophe; Nicholas, Kevin R

2016-11-01

Our research is exploiting the marsupial as a model to understand the signals required for lung development. Marsupials have a unique reproductive strategy, the mother gives birth to altricial neonate with an immature lung and the changes in milk composition during lactation in marsupials appears to provide bioactives that can regulate diverse aspects of lung development, including branching morphogenesis, cell proliferation and cell differentiation. These effects are seen with milk collected between 25 and 100days postpartum. To better understand the temporal effects of milk composition on postnatal lung development we used a cross-fostering technique to restrict the tammar pouch young to milk composition not extending beyond day 25 for 45days of its early postnatal life. These particular time points were selected as our previous study showed that milk protein collected prior to ~day 25 had no developmental effect on mouse embryonic lungs in culture. The comparative analysis of the foster group and control young at day 45 postpartum demonstrated that foster pouch young had significantly reduced lung size. The lungs in fostered young were comprised of large intermediate tissue, had a reduced size of airway lumen and a higher percentage of parenchymal tissue. In addition, expression of marker genes for lung development (BMP4, WNT11, AQP-4, HOPX and SPB) were significantly reduced in lungs from fostered young. Further, to identify the potential bioactive expressed by mammary gland that may have developmental effect on pouch young lungs, we performed proteomics analysis on tammar milk through mass-spectrometry and listed the potential bioactives (PDGF, IGFBP5, IGFBPL1 and EGFL6) secreted in milk that may be involved in regulating pouch young lung development. The data suggest that postnatal lung development in the tammar young is most likely regulated by maternal signalling factors supplied through milk. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd

Retroviral envelope gene captures and syncytin exaptation for placentation in marsupials

PubMed Central

Cornelis, Guillaume; Vernochet, Cécile; Carradec, Quentin; Souquere, Sylvie; Mulot, Baptiste; Catzeflis, François; Nilsson, Maria A.; Menzies, Brandon R.; Renfree, Marilyn B.; Pierron, Gérard; Zeller, Ulrich; Heidmann, Odile; Dupressoir, Anne; Heidmann, Thierry

2015-01-01

Syncytins are genes of retroviral origin captured by eutherian mammals, with a role in placentation. Here we show that some marsupials—which are the closest living relatives to eutherian mammals, although they diverged from the latter ∼190 Mya—also possess a syncytin gene. The gene identified in the South American marsupial opossum and dubbed syncytin-Opo1 has all of the characteristic features of a bona fide syncytin gene: It is fusogenic in an ex vivo cell–cell fusion assay; it is specifically expressed in the short-lived placenta at the level of the syncytial feto–maternal interface; and it is conserved in a functional state in a series of Monodelphis species. We further identify a nonfusogenic retroviral envelope gene that has been conserved for >80 My of evolution among all marsupials (including the opossum and the Australian tammar wallaby), with evidence for purifying selection and conservation of a canonical immunosuppressive domain, but with only limited expression in the placenta. This unusual captured gene, together with a third class of envelope genes from recently endogenized retroviruses—displaying strong expression in the uterine glands where retroviral particles can be detected—plausibly correspond to the different evolutionary statuses of a captured retroviral envelope gene, with only syncytin-Opo1 being the present-day bona fide syncytin active in the opossum and related species. This study would accordingly recapitulate the natural history of syncytin exaptation and evolution in a single species, and definitely extends the presence of such genes to all major placental mammalian clades. PMID:25605903

Common Distribution Patterns of Marsupials Related to Physiographical Diversity in Venezuela

PubMed Central

Ventura, Jacint; Bagaria, Guillem; Sans-Fuentes, Maria Assumpció; Pérez-Hernández, Roger

2014-01-01

The aim of this study is to identify significant biotic regions (groups of areas with similar biotas) and biotic elements (groups of taxa with similar distributions) for the marsupial fauna in a part of northern South America using physiographical areas as Operational Geographical Units (OGUs). We considered Venezuela a good model to elucidate this issue because of its high diversity in landscapes and the relatively vast amount of information available on the geographical distribution of marsupial species. Based on the presence-absence of 33 species in 15 physiographical sub-regions (OGUs) we identified Operational Biogeographical Units (OBUs) and chorotypes using a quantitative analysis that tested statistical significance of the resulting groups. Altitudinal and/or climatic trends in the OBUs and chorotypes were studied using a redundancy analysis. The classification method revealed four OBUs. Strong biotic boundaries separated: i) the xerophytic zone of the Continental coast (OBU I); ii) the sub-regions north of the Orinoco River (OBU III and IV); and those south to the river (OBU II). Eleven chorotypes were identified, four of which included a single species with a restricted geographic distribution. As for the other chorotypes, three main common distribution patterns have been inferred: i) species from the Llanos and/or distributed south of the Orinoco River; ii) species exclusively from the Andes; and iii) species that either occur exclusively north of the Orinoco River or that show a wide distribution throughout Venezuela. Mean altitude, evapotranspiration and precipitation of the driest month, and temperature range allowed us to characterize environmentally most of the OBUs and chorotypes obtained. PMID:24806452

Dealing with uncertainty in landscape genetic resistance models: a case of three co-occurring marsupials.

PubMed

Dudaniec, Rachael Y; Worthington Wilmer, Jessica; Hanson, Jeffrey O; Warren, Matthew; Bell, Sarah; Rhodes, Jonathan R

2016-01-01

Landscape genetics lacks explicit methods for dealing with the uncertainty in landscape resistance estimation, which is particularly problematic when sample sizes of individuals are small. Unless uncertainty can be quantified, valuable but small data sets may be rendered unusable for conservation purposes. We offer a method to quantify uncertainty in landscape resistance estimates using multimodel inference as an improvement over single model-based inference. We illustrate the approach empirically using co-occurring, woodland-preferring Australian marsupials within a common study area: two arboreal gliders (Petaurus breviceps, and Petaurus norfolcensis) and one ground-dwelling antechinus (Antechinus flavipes). First, we use maximum-likelihood and a bootstrap procedure to identify the best-supported isolation-by-resistance model out of 56 models defined by linear and non-linear resistance functions. We then quantify uncertainty in resistance estimates by examining parameter selection probabilities from the bootstrapped data. The selection probabilities provide estimates of uncertainty in the parameters that drive the relationships between landscape features and resistance. We then validate our method for quantifying uncertainty using simulated genetic and landscape data showing that for most parameter combinations it provides sensible estimates of uncertainty. We conclude that small data sets can be informative in landscape genetic analyses provided uncertainty can be explicitly quantified. Being explicit about uncertainty in landscape genetic models will make results more interpretable and useful for conservation decision-making, where dealing with uncertainty is critical. © 2015 John Wiley & Sons Ltd.

Functional-adaptive anatomy of the forelimb in the Didelphidae, and the paleobiology of the Paleocene marsupials Mayulestes ferox and Pucadelphys andinus.

PubMed

Argot, C

2001-01-01

An attempt to determine the locomotor activities of Mayulestes ferox (Borhyaenoidea) and Pucadelphys andinus (Didelphoidea) from the early Paleocene site of Tiupampa (Bolivia) is presented. The functional anatomy of the forelimbs of these South American marsupials is compared to that of some living didelphids: Caluromys philander, Micoureus demerarae, Marmosa murina, Didelphis marsupialis, Monodelphis brevicaudata and Metachirus nudicaudatus. Deductions from bone morphology to myology and locomotor behavior in the fossils are inferred from the comparisons with living forms. Some features of the postcranial skeleton, indicative of arboreal adaptations, are found in the extinct marsupials: anteriorly projected acromion, hemispherical head of the humerus, extended humeral lateral epicondylar ridge, medially protruding humeral entepicondyle, proximal ulnar posterior convexity, and deep flexor fossa on the medial side of the ulna. But other features are related to a more terrestrial pattern: the well-developed tubercles of the humeral head, the elongated olecranon process of the ulna, and the oval shape of the radial head. Mayulestes had clear arboreal abilities, but, as a predaceous mammal, probably hunted on the ground. Pucadelphys was less specialized, close to the living Monodelphis, a terrestrial insectivorous form with some skeletal features related to arboreal locomotion that are probably plesiomorphic for marsupials. Copyright 2001 Wiley-Liss, Inc.

Dissociation and preservation of preantral follicles and immature oocytes from female dasyurid marsupials.

PubMed

Czarny, N A; Harris, M S; Rodger, J C

2009-01-01

The mammalian ovary contains numerous immature preantral follicles that are not dependent on endocrine support, unlike the more mature hormone-dependent antral follicles. Preantral follicles can be enzymatically dissociated to yield immature oocytes that survive sub-zero preservation better as they lack a temperature-sensitive meiotic spindle. These techniques are highly applicable to gamete banking, which is an urgent requirement for Australian carnivorous marsupials as several species have rapidly declining populations and risk extinction. The present study developed protocols for the transport, dissociation, preservation and culture of granulosa cell-oocyte complexes (GOC) from the ovaries of dasyurid marsupials. High viability of GOC following enzymatic dissociation is reported and it was demonstrated that GOC are of significantly better quality following refrigerated storage for 24 h compared with storage at room temperature. Oocytes from primary follicles were not damaged by cold shock or the toxicity of vitrification media and following vitrification in liquid nitrogen 69.42+/-2.44% of oocytes were viable. However, the surrounding granulosa cells demonstrated significant damage post-thaw. These granulosa cells proliferated during a 48-h culture period resulting in significant improvements in GOC quality. The present study is a valuable step towards cryostorage of dasyurid gametes and represents fundamentally important methods by which we can contribute to the conservation of Australia's native predators.

Marsupials as models for understanding the role of chromosome rearrangements in evolution and disease.

PubMed

Deakin, Janine E; Kruger-Andrzejewska, Maya

2016-09-01

Chromosome rearrangements have been implicated in diseases, such as cancer, and speciation, but it remains unclear whether rearrangements are causal or merely a consequence of these processes. Two marsupial families with very different rates of karyotype evolution provide excellent models in which to study the role of chromosome rearrangements in a disease and evolutionary context. The speciose family Dasyuridae displays remarkable karyotypic conservation, with all species examined to date possessing nearly identical karyotypes. Despite the seemingly high degree of chromosome stability within this family, they appear prone to developing tumours, including transmissible devil facial tumours. In contrast, chromosome rearrangements have been frequent in the evolution of the species-rich family Macropodidae, which displays a high level of karyotypic diversity. In particular, the genus Petrogale (rock-wallabies) displays an extraordinary level of chromosome rearrangement among species. For six parapatric Petrogale species, it appears that speciation has essentially been caught in the act, providing an opportunity to determine whether chromosomal rearrangements are a cause or consequence of speciation in this system. This review highlights the reasons that these two marsupial families are excellent models for testing hypotheses for hotspots of chromosome rearrangement and deciphering the role of chromosome rearrangements in disease and speciation.

Marsupials and monotremes possess a novel family of MHC class I genes that is lost from the eutherian lineage.

PubMed

Papenfuss, Anthony T; Feng, Zhi-Ping; Krasnec, Katina; Deakin, Janine E; Baker, Michelle L; Miller, Robert D

2015-07-22

Major histocompatibility complex (MHC) class I genes are found in the genomes of all jawed vertebrates. The evolution of this gene family is closely tied to the evolution of the vertebrate genome. Family members are frequently found in four paralogous regions, which were formed in two rounds of genome duplication in the early vertebrates, but in some species class Is have been subject to additional duplication or translocation, creating additional clusters. The gene family is traditionally grouped into two subtypes: classical MHC class I genes that are usually MHC-linked, highly polymorphic, expressed in a broad range of tissues and present endogenously-derived peptides to cytotoxic T-cells; and non-classical MHC class I genes generally have lower polymorphism, may have tissue-specific expression and have evolved to perform immune-related or non-immune functions. As immune genes can evolve rapidly and are subject to different selection pressure, we hypothesised that there may be divergent, as yet unannotated or uncharacterised class I genes. Application of a novel method of sensitive genome searching of available vertebrate genome sequences revealed a new, extensive sub-family of divergent MHC class I genes, denoted as UT, which has not previously been characterized. These class I genes are found in both American and Australian marsupials, and in monotremes, at an evolutionary chromosomal breakpoint, but are not present in non-mammalian genomes and have been lost from the eutherian lineage. We show that UT family members are expressed in the thymus of the gray short-tailed opossum and in other immune tissues of several Australian marsupials. Structural homology modelling shows that the proteins encoded by this family are predicted to have an open, though short, antigen-binding groove. We have identified a novel sub-family of putatively non-classical MHC class I genes that are specific to marsupials and monotremes. This family was present in the ancestral mammal and

Characterization of a marsupial sperm protamine gene and its transcripts from the North American opossum (Didelphis marsupialis).

PubMed

Winkfein, R J; Nishikawa, S; Connor, W; Dixon, G H

1993-07-01

A synthetic oligonucleotide primer, designed from marsupial protamine protein-sequence data [Balhorn, R., Corzett, M., Matrimas, J. A., Cummins, J. & Faden, B. (1989) Analysis of protamines isolated from two marsupials, the ring-tailed wallaby and gray short-tailed opossum, J. Cell. Biol. 107] was used to amplify, via the polymerase chain reaction, protamine sequences from a North American opossum (Didelphis marsupialis) cDNA. Using the amplified sequences as probes, several protamine cDNA clones were isolated. The protein sequence, predicted from the cDNA sequences, consisted of 57 amino acids, contained a large number of arginine residues and exhibited the sequence ARYR at its amino terminus, which is conserved in avian and most eutherian mammal protamines. Like the true protamines of trout and chicken, the opossum protamine lacked cysteine residues, distinguishing it from placental mammalian protamine 1 (P1 or stable) protamines. Examination of the protamine gene, isolated by polymerase-chain-reaction amplification of genomic DNA, revealed the presence of an intron dividing the protamine-coding region, a common characteristic of all mammalian P1 genes. In addition, extensive sequence identity in the 5' and 3' flanking regions between mouse and opossum sequences classify the marsupial protamine as being closely related to placental mammal P1. Protamine transcripts, in both birds and mammals, are present in two size classes, differing by the length of their poly(A) tails (either short or long). Examination of opossum protamine transcripts by Northern hybridization revealed four distinct mRNA species in the total RNA fraction, two of which were enriched in the poly(A)-rich fraction. Northern-blot analysis, using an intron-specific probe, revealed the presence of intron sequences in two of the four protamine transcripts. If expressed, the corresponding protein from intron-containing transcripts would differ from spliced transcripts by length (49 versus 57 amino

Activity map of the tammar X chromosome shows that marsupial X inactivation is incomplete and escape is stochastic

PubMed Central

2010-01-01

Background X chromosome inactivation is a spectacular example of epigenetic silencing. In order to deduce how this complex system evolved, we examined X inactivation in a model marsupial, the tammar wallaby (Macropus eugenii). In marsupials, X inactivation is known to be paternal, incomplete and tissue-specific, and occurs in the absence of an XIST orthologue. Results We examined expression of X-borne genes using quantitative PCR, revealing a range of dosage compensation for different loci. To assess the frequency of 1X- or 2X-active fibroblasts, we investigated expression of 32 X-borne genes at the cellular level using RNA-FISH. In female fibroblasts, two-color RNA-FISH showed that genes were coordinately expressed from the same X (active X) in nuclei in which both loci were inactivated. However, loci on the other X escape inactivation independently, with each locus showing a characteristic frequency of 1X-active and 2X-active nuclei, equivalent to stochastic escape. We constructed an activity map of the tammar wallaby inactive X chromosome, which identified no relationship between gene location and extent of inactivation, nor any correlation with the presence or absence of a Y-borne paralog. Conclusions In the tammar wallaby, one X (presumed to be maternal) is expressed in all cells, but genes on the other (paternal) X escape inactivation independently and at characteristic frequencies. The paternal and incomplete X chromosome inactivation in marsupials, with stochastic escape, appears to be quite distinct from the X chromosome inactivation process in eutherians. We find no evidence for a polar spread of inactivation from an X inactivation center. PMID:21182760

Aerobic power, huddling and the efficiency of torpor in the South American marsupial, Dromiciops gliroides

PubMed Central

Franco, Marcela; Contreras, Carolina; Cortés, Pablo; Chappell, Mark A.; Soto-Gamboa, Mauricio; Nespolo, Roberto F.

2012-01-01

Summary During periods of cold, small endotherms depend on a continuous supply of food and energy to maintain euthermic body temperature (Tb), which can be challenging if food is limited. In these conditions, energy-saving strategies are critical to reduce the energetic requirements for survival. Mammals from temperate regions show a wide arrange of such strategies, including torpor and huddling. Here we provide a quantitative description of thermoregulatory capacities and energy-saving strategies in Dromiciops gliroides, a Microbiotherid marsupial inhabiting temperate rain forests. Unlike many mammals from temperate regions, preliminary studies have suggested that this species has low capacity for control and regulation of body temperature, but there is still an incomplete picture of its bioenergetics. In order to more fully understand the physiological capacities of this “living fossil”, we measured its scope of aerobic power and the interaction between huddling and torpor. Specifically, we evaluated: (1) the relation between basal (BMR) and maximum metabolic rate (MMR), and (2) the role of huddling on the characteristics of torpor at different temperatures. We found that BMR and MMR were above the expected values for marsupials and the factorial aerobic scope (from CO2) was 6.0±0.45 (using CO2) and 6.2±0.23 (using O2), an unusually low value for mammals. Also, repeatability of physiological variables was non-significant, as in previous studies, suggesting poor time-consistency of energy metabolism. Comparisons of energy expenditure and body temperature (using attached data-loggers) between grouped and isolated individuals showed that at 20°C both average resting metabolic rate and body temperature were higher in groups, essentially because animals remained non-torpid. At 10°C, however, all individuals became torpid and no differences were observed between grouped and isolated individuals. In summary, our study suggests that the main response of

Acid-base balance in the developing marsupial: from ectotherm to endotherm.

PubMed

Andrewartha, Sarah J; Cummings, Kevin J; Frappell, Peter B

2014-05-01

Marsupial joeys are born ectothermic and develop endothermy within their mother's thermally stable pouch. We hypothesized that Tammar wallaby joeys would switch from α-stat to pH-stat regulation during the transition from ectothermy to endothermy. To address this, we compared ventilation (Ve), metabolic rate (Vo2), and variables relevant to blood gas and acid-base regulation and oxygen transport including the ventilatory requirements (Ve/Vo2 and Ve/Vco2), partial pressures of oxygen (PaO2), carbon dioxide (PaCO2), pHa, and oxygen content (CaO2) during progressive hypothermia in ecto- and endothermic Tammar wallabies. We also measured the same variables in the well-studied endotherm, the Sprague-Dawley rat. Hypothermia was induced in unrestrained, unanesthetized joeys and rats by progressively dropping the ambient temperature (Ta). Rats were additionally exposed to helox (80% helium, 20% oxygen) to facilitate heat loss. Respiratory, metabolic, and blood-gas variables were measured over a large body temperature (Tb) range (∼15-16°C in both species). Ectothermic joeys displayed limited thermogenic ability during cooling: after an initial plateau, Vo2 decreased with the progressive drop in Tb. The Tb of endothermic joeys and rats fell despite Vo2 nearly doubling with the initiation of cold stress. In all three groups the changes in Vo2 were met by changes in Ve, resulting in constant Ve/Vo2 and Ve/Vco2, blood gases, and pHa. Thus, although thermogenic capability was nearly absent in ectothermic joeys, blood acid-base regulation was similar to endothermic joeys and rats. This suggests that unlike some reptiles, unanesthetized mammals protect arterial blood pH with changing Tb, irrespective of their thermogenic ability and/or stage of development.

Herds Overhead: Nimbadon lavarackorum (Diprotodontidae), Heavyweight Marsupial Herbivores in the Miocene Forests of Australia

PubMed Central

Black, Karen H.; Camens, Aaron B.; Archer, Michael; Hand, Suzanne J.

2012-01-01

The marsupial family Diprotodontidae (Diprotodontia, Vombatiformes) is a group of extinct large-bodied (60–2500 kg) wombat-like herbivores that were common and geographically widespread in Cenozoic fossil deposits of Australia and New Guinea. Typically they are regarded to be gregarious, terrestrial quadrupeds and have been likened in body form among placental groups to sheep, rhinoceros and hippopotami. Arguably, one of the best represented species is the zygomaturine diprotodontid Nimbadon lavarackorum which is known from exceptionally well-preserved cranial and postcranial material from the middle Miocene cave deposit AL90, in the Riversleigh World Heritage Area, northwestern Queensland. Here we describe and functionally analyse the appendicular skeleton of Nimbadon lavarackorum and reveal a far more unique lifestyle for this plesiomorphic and smallest of diprotodontids. Striking similarities are evident between the skeleton of Nimbadon and that of the extant arboreal koala Phascolarctos cinereus, including the powerfully built forelimbs, highly mobile shoulder and elbow joints, proportionately large manus and pes (both with a semi-opposable digit I) and exceedingly large, recurved and laterally compressed claws. Combined with the unique (among australidelphians) proportionately shortened hindlimbs of Nimbadon, these features suggest adept climbing ability, probable suspensory behaviour, and an arboreal lifestyle. At approximately 70 kg, Nimbadon is the largest herbivorous mammal to have occupied the forest canopies of Australia - an ecological niche that is no longer occupied in any Australian ecosystem and one that further expands the already significant niche diversity displayed by marsupials during the Cenozoic. PMID:23185250

New Trypanosoma species, Trypanosoma gennarii sp. nov., from South American marsupial in Brazilian Cerrado.

PubMed

Ferreira, Juliana I G S; da Costa, Andréa P; Nunes, Pablo Henrique; Ramirez, Diego; Fournier, Gislene F R; Saraiva, Danilo; Tonhosolo, Renata; Marcili, Arlei

2017-12-01

Hundreds of trypanosome species have been described in all mammalian orders, on every continent, including with mixed infections. Trypanosomes circulate in the form of sylvatic enzootic infections transmitted by blood-sucking insects that are associated with the host mammals. Small wild mammals were caught in a fragment of Cerrado terrain on an island in the hydroelectric reservoir of Três Marias, in the central region of the state of Minas Gerais, using pitfall and Sherman traps with different means of attraction. DNA samples from these mammals were subjected to the conventional polymerase chain reaction (PCR) for the full-length genes SSU rDNA and gGAPDH. A total of 232 animals of the orders Didelphimorphia, Rodentia, Chiroptera and Cingulata were caught (total of 17 species). There were also four species of marsupials: Monodelphis domestica, Didelphis albiventris, Gralicinanus agilis and Micoureus paraguaianus. Among these, there were eight positive individuals of Monodelphis domestica. However, nine cultures were established, because one of them was parasitized by two species of trypanosomes: Trypanosoma cruzi and a new trypanosome species. The new species have a large epimastigote forms, and with a well-developed undulating membrane in trypomastigote forms. The new species Trypanosoma gennarii was described in Monodelphis domestica. Copyright © 2017 Elsevier B.V. All rights reserved.

Bronchial circulation in the marsupial opossum, Didelphis marsupialis.

PubMed

Bernard, S L; Luchtel, D L; Glenny, R W; Lakshminarayan, S

1996-08-01

This study characterizes the existence of a bronchial circulation in a marsupial, an animal which does not undergo placental development and does not have a ductus arteriosus. Direct perfusion of the lung by the pulmonary vasculature during the fetal development of opossums may occur, potentially eliminating the need for a bronchial circulation. We used radio- and fluorescent-labeled microspheres in conjunction with postmortem intravascular casting to determine if opossums have a systemic (bronchial) blood supply to the lung (n = 9). Gross postmortem examination of the intravascular casts showed a well-developed common bronchial artery. The histological distribution pattern of fluorescent microspheres was primarily to the airways. A few fluorescent microspheres were observed in the alveolar capillaries, indicating that a precapillary bronchial-to-pulmonary anastomosis exists in the opossum. Using the reference flow technique, total bronchial blood flow to the left lung averaged 0.95 +/- 0.58 SE ml/min. The presence of a bronchial circulation in the opossum suggests that it is more than a vestigial structure from embryonic development, potentially supporting its functional importance for carrying nutrients to the airway.

THE USE OF THE LIGASURE™ DEVICE FOR SCROTAL ABLATION IN MARSUPIALS.

PubMed

Cusack, Lara; Cutler, Daniel; Mayer, Joerg

2017-03-01

Five sugar gliders ( Petaurus breviceps ), ranging in age from 3 mo to 3.5 yr of age, and one opossum ( Didelphis virginianus ), age 4.5 mo, presented for elective orchiectomy and scrotal ablation. The LigaSure™ device was safely used for orchiectomy and scrotal ablation in both species. Surgical time with the LigaSure was approximately 4 sec. No grooming of the incision site or self-mutilation was seen in the first 72 hr postoperatively. One sugar glider required postoperative wound care approximately 10 days postoperatively following incision-site grooming by a conspecific. The LigaSure provides a rapid, technologically simple and safe surgical technique for scrotal ablation and orchiectomy in the marsupial patient that minimizes surgical, anesthetic, and recovery times.

[Genotoxic damage among artisanal and small-scale mining workers exposed to mercury].

PubMed

Rosales-Rimache, Jaime A; Elizabeth Malca, Nancy; Alarcón, Jhonatan J; Chávez, Manuel; Gonzáles, Marco Antonio

2013-01-01

To determine the genotoxic damage among artisanal and small-scale mining workers exposed to mercury. Observational cross-sectional study which evaluated mercury-exposed workers (n=83), whose cells were collected by mouth swab for further staining, microscopic observance, micronuclei count, and other nuclear alterations. 24-hour urine was also collected for the determination of inorganic mercury. 68.7% of participants were male, the mean age being 43 ± 12,4 years (range: 16-76). The average time of occupational exposure to mercury was 12,1 ± 6,7 years, and the contact with mercury was 4,1 ± 3,6 kg per person per day. 93% of participants failed to wear personal protection gear while handling mercury. Results of biological monitoring showed that 17% of participants had concentrations of mercury in urine higher than 2,5 µg/L, this value being the detection limit of the measurement technique used. Results of the genotoxic evaluation evidenced that 15% of people with labor exposure to mercury presented micronuclei in mouth epithelial cells, and other indicators of nuclear alteration such as nucleoplasmic bridges, gemmation and binucleation were found, which are also considered genotoxic events associated to the exposure of physical or chemical risk agents. The finding of micronuclei in mouth epithelial cells reflects genotoxic damage associated to the labor exposure of mercury used in artisanal and small-scale mining activities.

Development of the ethmoid in Caluromys philander (Didelphidae, Marsupialia) with a discussion on the homology of the turbinal elements in marsupials.

PubMed

Macrini, Thomas E

2014-11-01

Homology of turbinals, or scroll bones, of the mammalian ethmoid bone is poorly known and complicated by a varied terminology. Positionally, there are two main types of ossified adult turbinals known as endoturbinals and ectoturbinals, and their cartilaginous precursors are called ethmoturbinals and frontoturbinals, respectively. Endoturbinals are considered to be serially homologous due to similarity in their developmental patterns. Consequently, endoturbinals from mammals with differing numbers of elements cannot be individually homogenized. In this study, the development of the ethmoid of Caluromys philander, the bare-tailed woolly opossum, is described based on serial sections of six pouchlings ranging in age from 20 to 84 days postnatal (PND-84), and computed tomography images of an adult skull. I found that four ethmoturbinals initially develop as seen in PND-20 and PND-30 individuals but by PND-64 an interturbinal (corresponding to endoturbinal III in adults) is present between ethmoturbinals II and III. This developmental pattern is identical to that of Monodelphis domestica, the gray short-tailed opossum, and is probably also present in the marsupials Didelphis marsupialis, and Thylacinus cynocephalus based on work of previous authors. These data suggest that endoturbinal III has a developmental pattern that differs from other endoturbinals, and the name interturbinal should be retained for the adult structure in recognition of this difference. These results may prove useful for homologizing this individual turbinal element across marsupials, the majority of which have five endoturbinals as adults. This might also explain the presumed placental ancestral condition of four endoturbinals if the marsupial interturbinal is lost. © 2014 Wiley Periodicals, Inc.

The oldest modern therian mammal from Europe and its bearing on stem marsupial paleobiogeography.

PubMed

Vullo, Romain; Gheerbrant, Emmanuel; de Muizon, Christian; Néraudeau, Didier

2009-11-24

We report the discovery of mammalian tribosphenic teeth from the basal Cenomanian of southwestern France that we refer to a new primitive marsupial-like form identified as a basal taxon of Marsupialiformes, a new clade recognized here to include the crown group Marsupialia and primitive stem lineages more closely related to Marsupialia than to Deltatheroida. Arcantiodelphys marchandi gen et sp nov. shares several significant marsupial-like features (s.l.) with marsupialiform taxa known from the North American Mid-Cretaceous. Among marsupialiforms, it shows a closer resemblance to Dakotadens. This resemblance, which is plesiomorphic within "tribotherians," makes Arcantiodelphys one of the most archaic known Marsupialiformes. Moreover, Arcantiodelphys is characterized by an original and precocious crushing specialization. Both the plesiomorphic and autapomorphic characteristics of Arcantiodelphys among Marsupialiformes might be explained by an Eastern origin from Asian stem metatherians, with some in situ European evolution. In addition, the presence of a mammal with North American affinities in western Europe during the early Late Cretaceous provides further evidence of a large Euramerican biogeographical province at this age or slightly before. Concerning the paleobiogeographical history of the first stem marsupialiforms during the Albian-Cenomanian interval, 2 possible dispersal routes from an Asian metatherian ancestry can be proposed: Asia to Europe via North America and Asia to North America via Europe. The main significance of the Archingeay-Les Nouillers mammal discovery is that it indicates that the beginning of the stem marsupialiforms history involved not only North America but also Europe, and that this early history in Europe remains virtually unknown.

The oldest modern therian mammal from Europe and its bearing on stem marsupial paleobiogeography

PubMed Central

Vullo, Romain; Gheerbrant, Emmanuel; de Muizon, Christian; Néraudeau, Didier

2009-01-01

We report the discovery of mammalian tribosphenic teeth from the basal Cenomanian of southwestern France that we refer to a new primitive marsupial-like form identified as a basal taxon of Marsupialiformes, a new clade recognized here to include the crown group Marsupialia and primitive stem lineages more closely related to Marsupialia than to Deltatheroida. Arcantiodelphys marchandi gen et sp nov. shares several significant marsupial-like features (s.l.) with marsupialiform taxa known from the North American Mid-Cretaceous. Among marsupialiforms, it shows a closer resemblance to Dakotadens. This resemblance, which is plesiomorphic within “tribotherians,” makes Arcantiodelphys one of the most archaic known Marsupialiformes. Moreover, Arcantiodelphys is characterized by an original and precocious crushing specialization. Both the plesiomorphic and autapomorphic characteristics of Arcantiodelphys among Marsupialiformes might be explained by an Eastern origin from Asian stem metatherians, with some in situ European evolution. In addition, the presence of a mammal with North American affinities in western Europe during the early Late Cretaceous provides further evidence of a large Euramerican biogeographical province at this age or slightly before. Concerning the paleobiogeographical history of the first stem marsupialiforms during the Albian–Cenomanian interval, 2 possible dispersal routes from an Asian metatherian ancestry can be proposed: Asia to Europe via North America and Asia to North America via Europe. The main significance of the Archingeay-Les Nouillers mammal discovery is that it indicates that the beginning of the stem marsupialiforms history involved not only North America but also Europe, and that this early history in Europe remains virtually unknown. PMID:19892730

Extreme Telomere Length Dimorphism in the Tasmanian Devil and Related Marsupials Suggests Parental Control of Telomere Length

PubMed Central

Bender, Hannah S.; Murchison, Elizabeth P.; Pickett, Hilda A.; Deakin, Janine E.; Strong, Margaret A.; Conlan, Carly; McMillan, Daniel A.; Neumann, Axel A.; Greider, Carol W.; Hannon, Gregory J.; Reddel, Roger R.; Graves, Jennifer A. Marshall.

2012-01-01

Telomeres, specialised structures that protect chromosome ends, play a critical role in preserving chromosome integrity. Telomere dynamics in the Tasmanian devil (Sarcophilus harrisii) are of particular interest in light of the emergence of devil facial tumour disease (DFTD), a transmissible malignancy that causes rapid mortality and threatens the species with extinction. We used fluorescent in situ hybridisation to investigate telomere length in DFTD cells, in healthy Tasmanian devils and in four closely related marsupial species. Here we report that animals in the Order Dasyuromorphia have chromosomes characterised by striking telomere length dimorphism between homologues. Findings in sex chromosomes suggest that telomere length dimorphism may be regulated by events in the parental germlines. Long telomeres on the Y chromosome imply that telomere lengthening occurs during spermatogenesis, whereas telomere diminution occurs during oogenesis. Although found in several somatic cell tissue types, telomere length dimorphism was not found in DFTD cancer cells, which are characterised by uniformly short telomeres. This is, to our knowledge, the first report of naturally occurring telomere length dimorphism in any species and suggests a novel strategy of telomere length control. Comparative studies in five distantly related marsupials and a monotreme indicate that telomere dimorphism evolved at least 50 million years ago. PMID:23049977

Serologic and Molecular Evidence of Vaccinia Virus Circulation among Small Mammals from Different Biomes, Brazil

PubMed Central

Miranda, Júlia B.; Borges, Iara A.; Campos, Samantha P.S.; Vieira, Flávia N.; de Ázara, Tatiana M.F.; Marques, Fernanda A.; Costa, Galileu B.; Luis, Ana Paula M.F.; de Oliveira, Jaqueline S.; Ferreira, Paulo César P.; Bonjardim, Cláudio Antônio; da Silva, Silvio L.M.; Eiras, Álvaro E.; Abrahão, Jônatas S.; Kroon, Erna G.; Drumond, Betânia P.; Paglia, Adriano P.

2017-01-01

Vaccinia virus (VACV) is a zoonotic agent that causes a disease called bovine vaccinia, which is detected mainly in milking cattle and humans in close contact with these animals. Even though many aspects of VACV infection have been described, much is still unknown about its circulation in the environment and its natural hosts/reservoirs. To investigate the presence of Orthopoxvirus antibodies or VACV DNA, we captured small rodents and marsupials in 3 areas of Minas Gerais state, Brazil, and tested their samples in a laboratory. A total of 336 animals were tested; positivity ranged from 18.1% to 25.5% in the 3 studied regions located in different biomes, including the Atlantic Forest and the Cerrado. Analysis of nucleotide sequences indicated co-circulation of VACV groups I and II. Our findings reinforce the possible role played by rodents and marsupials in VACV maintenance and its transmission chain. PMID:28518030

Development of thermoregulation and torpor in a marsupial: energetic and evolutionary implications.

PubMed

Geiser, Fritz; Westman, Wendy; McAllan, Bronwyn M; Brigham, R Mark

2006-02-01

Altricial mammals and birds become endothermic at about half the size of adults and presumably would benefit energetically from entering torpor at that time. Because little is known about torpor during development in endotherms, we investigated whether after the establishment of endothermic thermoregulation (i.e. the ability to maintain a high body temperature during cold exposure), Sminthopsis macroura, a small (approximately 25 g) insectivorous marsupial, is capable of entering torpor and whether torpor patterns change with growth. Endothermic thermoregulation was established when the nest young reached a body mass of approximately 10 g, and they were capable of entering torpor early during development at approximately 10-12 g, lending some support to the view that torpor is a phylogenetically old mammalian trait. Torpor bout length shortened significantly and the minimum metabolic rate during torpor increased as juveniles approached adult size, and consequently total daily energy expenditure increased steeply with age. Relationships between total daily energy expenditure and body mass during development of S. macroura (slope approximately 1.3) differed substantially from the relationship between basal metabolism and body mass in adult endotherms (slope approximately 0.75) suggesting that the energy expenditure-size relationship during the development differs substantially from that in adults under thermo-neutral conditions. Our study shows that while torpor can substantially reduce energy expenditure during development of endotherms and hence is likely important for survival during energy bottlenecks, it also may enhance somatic growth when food is limited. We therefore hypothesize that torpor during the development in endotherms is far more widespread than is currently appreciated.

Serologic evidence of the exposure of small mammals to spotted-fever Rickettsia and Rickettsia bellii in Minas Gerais, Brazil.

PubMed

Coelho, Marcella Gonçalves; Ramos, Vanessa do Nascimento; Limongi, Jean Ezequiel; de Lemos, Elba Regina Sampaio; Guterres, Alexandro; da Costa Neto, Sócrates Fraga; Rozental, Tatiana; Bonvicino, Cibele Rodrigues; D'Andrea, Paulo Sérgio; Moraes-Filho, Jonas; Labruna, Marcelo Bahia; Szabó, Matias Pablo Juan

2016-03-31

Sources of pathogenic Rickettsia in wildlife are largely unknown in Brazil. In this work, potential tick vectors and seroreactivity of small mammals against four spotted-fever group Rickettsia (R. rickettsii, R. parkeri, R. amblyommii and R. rhipicephali) and Rickettsia bellii from peri-urban areas of Uberlândia, a major town in Brazil, are described for the first time. Small mammals were captured and blood samples collected. Ticks were collected from the surface of the host and the environment and posteriorly identified. Reactivity of small mammal sera to Rickettsia was tested by indirect immunofluorescence assay (IFA) using crude antigens from five Brazilian Rickettsia isolates. Information was obtained from 416 small mammals (48 Marsupialia and 368 Rodentia). Forty-eight animals were parasitized and two tick species, Ixodes loricatus and Amblyomma dubitatum, were found on several host species, with a few tick-host relationships described for the first time. From the 416 tested sera, 70 reacted to at least one Rickettsia antigen (prevalence of 16.8%) and from these, 19 (27.1%) reacted to two or more antigens. Seroprevalence was higher for marsupials (39.6%) than for rodents (13.8%). Marsupial and Rhipidomys spp. sera reacted mainly (highest seroprevalence and titers) to R. bellii, and that of Necromys lasiurus mainly to R. rickettsii. Although the serologic assays poorly discriminate between closely related spotted-fever group Rickettsia, the observed small mammal seroreactivity suggests the circulation of Rickettsia in the peri-urban area of Uberlândia, albeit at low levels.

Orbit orientation in didelphid marsupials (Didelphimorphia: Didelphidae)

PubMed Central

Pilatti, Patricia

2017-01-01

Abstract Usually considered a morphologically conservative group, didelphid marsupials present considerable variation in ecology and body size, some of which were shown to relate to morphological structures. Thus, changes on orbit morphology are likely and could be related to that variation. We calculated orbit orientation in 873 specimens of 16 Didelphidae genera yielding estimates of orbits convergence (their position relative to midsagittal line) and verticality (their position relative to frontal plane). We then compared similarities in these variables across taxa to ecological, morphological and phylogenetic data to evaluate the influencing factors on orbit orientation in didelphids. We found an inverse relation between convergence and verticality. Didelphids orbits have low verticality but are highly convergent, yet orbit orientation differs significantly between taxa, and that variation is related to morphological aspects of the cranium. Rostral variables are the only morphological features correlated with orbit orientation: increasing snout length yields more convergent orbits, whereas increase on snout breadth imply in more vertical orbits. Size and encephalization quotients are uncorrelated with orbit orientation. Among ecological data, diet showed significant correlation whereas locomotion is the factor that less affects the position of orbits. Phylogeny is uncorrelated to any orbital parameters measured. Ecological factors seemingly play a more important role on orbit orientation than previously expected, and differentiation on orbit orientation seems to be more functional than inherited. Thus, despite the apparent homogeneity on didelphid morphology, there is subtle morphological variability that may be directly related to feeding behavior. PMID:29492000

The relationship between fetal growth restriction and small placenta in 6-mercaptopurine exposed rat.

PubMed

Furukawa, Satoshi; Hayashi, Seigo; Usuda, Koji; Abe, Masayoshi; Ogawa, Izumi

2011-01-01

In order to investigate the effect of placental size on fetal intrauterine growth retardation (IURG), we examined the morphology and alterations in the expression of glucose transporter in the placentas of rats exposed to 6-mercaptopurine (6-MP). 6-MP was administered orally at 0 and 60 mg/kg/day on gestation day (GD) 9, 11, 13 or 15, and the placentas were sampled on GDs 17 and 21. The main findings in the treated groups were small placenta caused by mitotic inhibition and apoptosis, fetal resorption and IUGR with or without some malformations. The most sensitive period to 6-MP-induced fetal mortality was found to be in the GD9-treated group, and the small placenta and fetal abnormalities in the GD11-treated group, respectively. However, the litters in a quarter of the dams with the treatment on GD 11 had no fetotoxicity despite 25% decline in the placental weight. Histopathologically, the expression of glucose transporter GLUT3 was increased in the trophoblastic septa in all treated groups, particularly remarkable with proliferation of trophoblasts in the above litters, where the fetal-placental weight ratio was increased. Thus, we consider that the normal fetal growth and development can be maintained caused by adaptive change, even if the placental weight decreased by approximately 25% in 6-MP exposed rats. Copyright © 2009 Elsevier GmbH. All rights reserved.

Mammals of South America, Volume 1, Marsupials, Xenarthrans, Shrews, and Bats

USGS Publications Warehouse

Gardner, A.L.

2007-01-01

The vast terrain between Panama and Tierra del Fuego contains some of the world?s richest mammalian fauna, but until now it has lacked a comprehensive systematic reference to the identification, distribution, and taxonomy of its mammals. The first such book of its kind and the inaugural volume in a three-part series, Mammals of South America both summarizes existing information and encourages further research of the mammals indigenous to the region. Containing identification keys and brief descriptions of each order, family, and genus, the first volume of Mammals of South America covers marsupials, shrews, armadillos, sloths, anteaters, and bats. Species accounts include taxonomic descriptions, synonymies, keys to identification, distributions with maps and a gazetteer of marginal localities, lists of recognized subspecies, brief summaries of natural history information, and discussions of issues related to taxonomic interpretations. Highly anticipated and much needed, this book will be a landmark contribution to mammalogy, zoology, tropical biology, and conservation biology.

Skeleton of an unusual, cat-sized marsupial relative (Metatheria: Marsupialiformes) from the middle Eocene (Lutetian: 44-43 million years ago) of Turkey

PubMed Central

Maga, A. Murat

2017-01-01

We describe a near-complete, three-dimensionally preserved skeleton of a metatherian (relative of modern marsupials) from the middle Eocene (Lutetian: 44–43 million years ago) Lülük member of the Uzunçarşıdere Formation, central Turkey. With an estimated body mass of 3–4 kg, about the size of a domestic cat (Felis catus) or spotted quoll (Dasyurus maculatus), it is an order of magnitude larger than the largest fossil metatherians previously known from the Cenozoic of the northern hemisphere. This new taxon is characterised by large, broad third premolars that probably represent adaptations for hard object feeding (durophagy), and its craniodental morphology suggests the capacity to generate high bite forces. Qualitative and quantitative functional analyses of its postcranial skeleton indicate that it was probably scansorial and relatively agile, perhaps broadly similar in locomotor mode to the spotted quoll, but with a greater capacity for climbing and grasping. Bayesian phylogenetic analysis of a total evidence dataset comprising 259 morphological characters and 9kb of DNA sequence data from five nuclear protein-coding genes, using both undated and “tip-and-node dating” approaches, place the new taxon outside the marsupial crown-clade, but within the clade Marsupialiformes. It demonstrates that at least one metatherian lineage evolved to occupy the small-medium, meso- or hypo-carnivore niche in the northern hemisphere during the early Cenozoic, at a time when there were numerous eutherians (placentals and their fossil relatives) filling similar niches. However, the known mammal fauna from Uzunçarşıdere Formation appears highly endemic, and geological evidence suggests that this region of Turkey was an island for at least part of the early Cenozoic, and so the new taxon may have evolved in isolation from potential eutherian competitors. Nevertheless, the new taxon reveals previously unsuspected ecomorphological disparity among northern hemisphere

Playing by the rules? Phenotypic adaptation to temperate environments in an American marsupial

PubMed Central

Harrigan, Ryan J.; Wayne, Robert K.

2018-01-01

Phenotypic variation along environmental gradients can provide evidence suggesting local adaptation has shaped observed morphological disparities. These differences, in traits such as body and extremity size, as well as skin and coat pigmentation, may affect the overall fitness of individuals in their environments. The Virginia opossum (Didelphis virginiana) is a marsupial that shows phenotypic variation across its range, one that has recently expanded into temperate environments. It is unknown, however, whether the variation observed in the species fits adaptive ecogeographic patterns, or if phenotypic change is associated with any environmental factors. Using phenotypic measurements of over 300 museum specimens of Virginia opossum, collected throughout its distribution range, we applied regression analysis to determine if phenotypes change along a latitudinal gradient. Then, using predictors from remote-sensing databases and a random forest algorithm, we tested environmental models to find the most important variables driving the phenotypic variation. We found that despite the recent expansion into temperate environments, the phenotypic variation in the Virginia opossum follows a latitudinal gradient fitting three adaptive ecogeographic patterns codified under Bergmann’s, Allen’s and Gloger’s rules. Temperature seasonality was an important predictor of body size variation, with larger opossums occurring at high latitudes with more seasonal environments. Annual mean temperature predicted important variation in extremity size, with smaller extremities found in northern populations. Finally, we found that precipitation and temperature seasonality as well as low temperatures were strong environmental predictors of skin and coat pigmentation variation; darker opossums are distributed at low latitudes in warmer environments with higher precipitation seasonality. These results indicate that the adaptive mechanisms underlying the variation in body size, extremity

Cytochrome P450 CYP3A in marsupials: cloning and identification of the first CYP3A subfamily member, isoform 3A70 from Eastern gray kangaroo (Macropus giganteus).

PubMed

El-Merhibi, Adaweyah; Ngo, Suong N T; Marchant, Ceilidh L; Height, Tamara A; Stupans, Ieva; McKinnon, Ross A

2012-09-15

Australian marsupials are unique fauna that have evolved and adapted to unique environments and thus it is likely that their detoxification systems differ considerably from those of well-studied eutherian mammals. Knowledge of these processes in marsupials is therefore vital to understanding the consequences of exposure to xenobiotics. Cytochromes P450 (CYPs) are critically important in the oxidative metabolism of a diverse array of both xenobiotics and endogenous substrates. In this study we have cloned and characterized CYP3A70, the first identified member of the CYP3A gene subfamily from Eastern gray kangaroo (Macropus giganteus). A 1665 base pair kangaroo hepatic CYP3A complete cDNA, designated CYP3A70, was cloned by reverse transcription-polymerase chain reaction approaches, which encodes a protein of 506 amino acids. The CYP3A70 cDNA shares approximately 71% nucleotide and 65% amino acid sequence homology to human CYP3A4 and displays high sequence similarity to other published mammalian CYP3As from human, monkey, cow, pig, dog, rat, rabbit, mouse, hamster, and guinea pig. Transfection of the CYP3A70 cDNAs into 293T cells resulted in stable cell lines expressing a CYP3A immuno-reactive protein that was recognized by a goat anti-human CYP3A4 polyclonal antibody. The anti-human CYP3A4 antibody also detected immunoreactive proteins in liver microsomes from all test marsupials, including the kangaroo, koala, wallaby, and wombat, with multiple CYP3A immunoreactive bands observed in kangaroo and wallaby tissues. Relatively, very low CYP catalytic activity was detected for the kangaroo CYP3A70 cDNA-expressed proteins (19.6 relative luminescent units/μg protein), which may be due to low protein expression levels. Collectively, this study provides primary molecular data regarding the Eastern kangaroo hepatic CYP3A70 gene and enables further functional analyses of CYP3A enzymes in marsupials. Copyright © 2012 Elsevier B.V. All rights reserved.

Increased concentration of Pseudomonas aeruginosa and Staphylococcus sp. in small animals exposed to aerospace environments

NASA Technical Reports Server (NTRS)

Guthrie, R. K.

1976-01-01

The effects of increased concentrations of PSEUDOMONAS AERUGINOSA AND STAPHYLOCOCCUS in the total bacterial flora of small animals exposed to simulated spacecraft environments were evaluated. Tests to detect changes in infectivity, effects of antibiotic treatments, immune responses to bacterial antigens, and effectiveness of immune responses in the experimental environment were conducted. The most significant results appear to be the differences in immune responses at simulated altitudes and the production of infection in the presence of a specific antibody.

The fur of mammals in exposed environments; do crypsis and thermal needs necessarily conflict? The polar bear and marsupial koala compared.

PubMed

Dawson, Terence J; Webster, Koa N; Maloney, Shane K

2014-02-01

The furs of mammals have varied and complex functions. Other than for thermoregulation, fur is involved in physical protection, sensory input, waterproofing and colouration, the latter being important for crypsis or camouflage. Some of these diverse functions potentially conflict. We have investigated how variation in cryptic colouration and thermal features may interact in the coats of mammals and influence potential heat inflows from solar radiation, much of which is outside the visible spectral range. The coats of the polar bear (Ursus maritimus) and the marsupial koala (Phascolarctus cinereus) have insulative similarities but, while they feature cryptic colouration, they are of contrasting colour, i.e. whitish and dark grey. The reflectance of solar radiation by coats was measured across the full solar spectrum using a spectroradiometer. The modulation of incident solar radiation and resultant heat flows in these coats were determined at a range of wind speeds by mounting them on a heat flux transducer/temperature-controlled plate apparatus in a wind tunnel. A lamp with a spectral distribution of radiation similar to the solar spectrum was used as a proxy for the sun. Crypsis by colour matching was apparent within the visible spectrum for the two species, U. maritimus being matched against snow and P. cinereus against Eucalyptus forest foliage. While reflectances across the full solar spectrum differed markedly, that of U. maritimus being 66 % as opposed to 10 % for P. cinereus, the heat influxes from solar radiation reaching the skin were similar. For both coats at low wind speed (1 m s(-1)), 19 % of incident solar radiation impacted as heat at the skin surface; at higher wind speed (10 m s(-1)) this decreased to approximately 10 %. Ursus maritimus and P. cinereus have high and comparable levels of fur insulation and although the patterns of reflectance and depths of penetrance of solar radiation differ for the coats, the considerable insulation limited the

The extraordinary biology and development of marsupial frogs (Hemiphractidae) in comparison with fish, mammals, birds, amphibians and other animals.

PubMed

Del Pino, Eugenia M

2018-01-03

The study of oogenesis and early development of frogs belonging to the family Hemiphractidae provide important comparison to the aquatic development of other frogs, such as Xenopus laevis, because reproduction on land characterizes the Hemiphractidae. In this review, the multinucleated oogenesis of the marsupial frog Flectonotus pygmaeus (Hemiphractidae) is analyzed and interpreted. In addition, the adaptations associated with the incubation of embryos in the pouch of the female marsupial frog Gastrotheca riobambae (Hemiphractidae) and the embryonic development of this frog are summarized. Moreover, G. riobambae gastrulation is compared with the gastrulation modes of Engystomops randi and Engystomops coloradorum (Leptodactylidae); Ceratophrys stolzmanni (Ceratophryidae); Hyalinobatrachium fleischmanni and Espadarana callistomma (Centrolenidae); Ameerega bilinguis, Dendrobates auratus, Epipedobates anthonyi, Epipedobates machalilla, Epipedobates tricolor, and Hyloxalus vertebralis (Dendrobatidae); Eleutherodactylus coqui (Terrarana: Eleutherodactylidae), and X. laevis (Pipidae). The comparison indicated two modes of frog gastrulation. In X. laevis and in frogs with aquatic reproduction, convergent extension begins during gastrulation. In contrast, convergent extension occurs in the post-gastrula of frogs with terrestrial reproduction. These two modes of gastrulation resemble the transitions toward meroblastic cleavage found in ray-finned fishes (Actinopterygii). In spite of this difference, the genes that guide early development seem to be highly conserved in frogs. I conclude that the shift of convergent extension to the post-gastrula accompanied the diversification of frog egg size and terrestrial reproductive modes. Copyright © 2018 Elsevier B.V. All rights reserved.

A new family of bizarre durophagous carnivorous marsupials from Miocene deposits in the Riversleigh World Heritage Area, northwestern Queensland.

PubMed

Archer, M; Hand, S J; Black, K H; Beck, R M D; Arena, D A; Wilson, L A B; Kealy, S; Hung, T-T

2016-05-27

A new specimen of the bizarrely specialised Malleodectes mirabilis from middle Miocene deposits in the Riversleigh World Heritage Area provides the first and only information about the molar dentition of this strange group of extinct marsupials. Apart from striking autapomorphies such as the enormous P3, other dental features such as stylar cusp D being larger than B suggest it belongs in the Order Dasyuromorphia. Phylogenetic analysis of 62 craniodental characters places Malleodectes within Dasyuromorphia albeit with weak support and without indication of specific relationships to any of the three established families (Dasyuridae, Myrmecobiidae and Thylacinidae). Accordingly we have allocated Malleodectes to the new family, Malleodectidae. Some features suggest potential links to previously named dasyuromorphians from Riversleigh (e.g., Ganbulanyi) but these are too poorly known to test this possibility. Although the original interpretation of a steeply declining molar row in Malleodectes can be rejected, it continues to seem likely that malleodectids specialised on snails but probably also consumed a wider range of prey items including small vertebrates. Whatever their actual diet, malleodectids appear to have filled a niche in Australia's rainforests that has not been occupied by any other mammal group anywhere in the world from the Miocene onwards.

A new family of bizarre durophagous carnivorous marsupials from Miocene deposits in the Riversleigh World Heritage Area, northwestern Queensland

NASA Astrophysics Data System (ADS)

Archer, M.; Hand, S. J.; Black, K. H.; Beck, R. M. D.; Arena, D. A.; Wilson, L. A. B.; Kealy, S.; Hung, T.-T.

2016-05-01

A new specimen of the bizarrely specialised Malleodectes mirabilis from middle Miocene deposits in the Riversleigh World Heritage Area provides the first and only information about the molar dentition of this strange group of extinct marsupials. Apart from striking autapomorphies such as the enormous P3, other dental features such as stylar cusp D being larger than B suggest it belongs in the Order Dasyuromorphia. Phylogenetic analysis of 62 craniodental characters places Malleodectes within Dasyuromorphia albeit with weak support and without indication of specific relationships to any of the three established families (Dasyuridae, Myrmecobiidae and Thylacinidae). Accordingly we have allocated Malleodectes to the new family, Malleodectidae. Some features suggest potential links to previously named dasyuromorphians from Riversleigh (e.g., Ganbulanyi) but these are too poorly known to test this possibility. Although the original interpretation of a steeply declining molar row in Malleodectes can be rejected, it continues to seem likely that malleodectids specialised on snails but probably also consumed a wider range of prey items including small vertebrates. Whatever their actual diet, malleodectids appear to have filled a niche in Australia’s rainforests that has not been occupied by any other mammal group anywhere in the world from the Miocene onwards.

Comparative Myology and Evolution of Marsupials and Other Vertebrates, With Notes on Complexity, Bauplan, and "Scala Naturae".

PubMed

Diogo, Rui; Bello-Hellegouarch, Gaelle; Kohlsdorf, Tiana; Esteve-Altava, Borja; Molnar, Julia L

2016-09-01

Opossums are frequent subjects of developmental studies because marsupials share developmental features not seen in placentals and because Didelphimorpha is the sister-group of other extant Marsupialia. But is the adult marsupial muscular system markedly different from that of placentals or is it, like the skeletal system, very similar? We provide, for the first time, a brief description of all head and limb muscles of Didelphis virginiana based on our dissections and using a unifying nomenclature by integrating the data gathered in our long-term project on the development, homologies, and evolution of the muscles of all major vertebrate taxa. Our data indicate that there were many more muscle synapomorphic changes from the last common ancestor (LCA) of amniotes to the mammalian LCA (63) and from this LCA to the LCA of extant therians (48) than from this latter LCA to the LCA of extant placentals (10 or 11). Importantly, Didelphis is anatomically more plesiomorphic (only 14 changes from LCA of extant therians) than are rats (37 changes) and humans (63 changes), but its musculature is more complex (193 muscles) than that of humans (only 180 muscles). Of the 194 muscles of Didelphis, 172 (89%) are present in rats, meaning that their adult muscle anatomy is indeed very similar. This similarity supports the existence of a common, easy recognizable therian Bauplan, but one that is caused by developmental constraints and by evolutionary change driven by the needs of the embryos/neonates, rather than by a "goal" toward a specific adult plan/"archetype," as the name Bauplan suggests. Anat Rec, 299:1224-1255, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Mitochondrial genome sequencing reveals potential origins of the scabies mite Sarcoptes scabiei infesting two iconic Australian marsupials.

PubMed

Fraser, Tamieka A; Shao, Renfu; Fountain-Jones, Nicholas M; Charleston, Michael; Martin, Alynn; Whiteley, Pam; Holme, Roz; Carver, Scott; Polkinghorne, Adam

2017-11-28

Debilitating skin infestations caused by the mite, Sarcoptes scabiei, have a profound impact on human and animal health globally. In Australia, this impact is evident across different segments of Australian society, with a growing recognition that it can contribute to rapid declines of native Australian marsupials. Cross-host transmission has been suggested to play a significant role in the epidemiology and origin of mite infestations in different species but a chronic lack of genetic resources has made further inferences difficult. To investigate the origins and molecular epidemiology of S. scabiei in Australian wildlife, we sequenced the mitochondrial genomes of S. scabiei from diseased wombats (Vombatus ursinus) and koalas (Phascolarctos cinereus) spanning New South Wales, Victoria and Tasmania, and compared them with the recently sequenced mitochondrial genome sequences of S. scabiei from humans. We found unique S. scabiei haplotypes among individual wombat and koala hosts with high sequence similarity (99.1% - 100%). Phylogenetic analysis of near full-length mitochondrial genomes revealed three clades of S. scabiei (one human and two marsupial), with no apparent geographic or host species pattern, suggestive of multiple introductions. The availability of additional mitochondrial gene sequences also enabled a re-evaluation of a range of putative molecular markers of S. scabiei, revealing that cox1 is the most informative gene for molecular epidemiological investigations. Utilising this gene target, we provide additional evidence to support cross-host transmission between different animal hosts. Our results suggest a history of parasite invasion through colonisation of Australia from hosts across the globe and the potential for cross-host transmission being a common feature of the epidemiology of this neglected pathogen. If this is the case, comparable patterns may exist elsewhere in the 'New World'. This work provides a basis for expanded molecular studies into

Seasonal changes in plasma androgens, glucocorticoids and glucocorticoid-binding proteins in the marsupial sugar glider Petaurus breviceps.

PubMed

Bradley, A J; Stoddart, D M

1992-01-01

An investigation spanning two breeding seasons was carried out to examine endocrine changes associated with reproduction in a wild population of the marsupial sugar glider Petaurus breviceps, a small arboreal gliding possum. Using techniques of equilibrium dialysis and polyacrylamide gel electrophoresis at steady-state conditions, a high-affinity, low-capacity glucocorticoid-binding protein was demonstrated in the plasma of Petaurus breviceps. Equilibrium dialysis at 36 degrees C using cortisol gave a high-affinity binding constant of 95 +/- 5.2 litres/mumol for a presumed corticosteroid-binding globulin (CBG) while the binding constant for the cortisol-albumin interaction was 3.5 +/- 0.4 litres/mmol. There was no difference between the sexes in the affinity of binding of cortisol to CBG; however, the cortisol-binding capacity underwent seasonal variation in both sexes. Progesterone was bound strongly to the presumed CBG while neither oestradiol nor aldosterone appeared to be bound with high affinity to P. breviceps plasma. In the males, peaks in the plasma concentration of testosterone coincided with the July-September breeding season in both years. A significant inverse relationship was shown to exist between the plasma testosterone concentration and the CBG-binding capacity. In both sexes an increase occurred in the plasma concentration of free cortisol during the first breeding season, a pattern which was not repeated in the subsequent breeding season, possibly due to a lower population density in that year.

Phenotypic plasticity of post-fire activity and thermal biology of a free-ranging small mammal.

PubMed

Stawski, Clare; Körtner, Gerhard; Nowack, Julia; Geiser, Fritz

2016-05-15

Ecosystems can change rapidly and sometimes irreversibly due to a number of anthropogenic and natural factors, such as deforestation and fire. How individual animals exposed to such changes respond behaviourally and physiologically is poorly understood. We quantified the phenotypic plasticity of activity patterns and torpor use - a highly efficient energy conservation mechanism - in brown antechinus (Antechinus stuartii), a small Australian marsupial mammal. We compared groups in densely vegetated forest areas (pre-fire and control) with a group in a burned, open habitat (post-fire). Activity and torpor patterns differed among groups and sexes. Females in the post-fire group spent significantly less time active than the other groups, both during the day and night. However, in males only daytime activity declined in the post-fire group, although overall activity was also reduced on cold days in males for all groups. The reduction in total or diurnal activity in the post-fire group was made energetically possible by a ~3.4-fold and ~2.2-fold increase in the proportion of time females and males, respectively, used torpor in comparison to that in the pre-fire and control groups. Overall, likely due to reproductive needs, torpor was more pronounced in females than in males, but low ambient temperatures increased torpor bout duration in both sexes. Importantly, for both male and female antechinus and likely other small mammals, predator avoidance and energy conservation - achieved by reduced activity and increased torpor use - appear to be vital for post-fire survival where ground cover and refuges have been obliterated. Copyright © 2016 Elsevier Inc. All rights reserved.

Unifying principles in terrestrial locomotion: do hopping Australian marsupials fit in?

PubMed

Bennett, M B

2000-01-01

Mammalian terrestrial locomotion has many unifying principles. However, the Macropodoidea are a particularly interesting group that exhibit a number of significant deviations from the principles that seem to apply to other mammals. While the properties of materials that comprise the musculoskeletal system of mammals are similar, evidence suggests that tendon properties in macropodoid marsupials may be size or function dependent, in contrast to the situation in placental mammals. Postural differences related to hopping versus running have a dramatic effect on the scaling of the pelvic limb musculoskeletal system. Ratios of muscle fibre to tendon cross-sectional areas for ankle extensors and digital flexors scale with positive allometry in all mammals, but exponents are significantly higher in macropods. Tendon safety factors decline with increasing body mass in mammals, with eutherians at risk of ankle extensor tendon rupture at a body mass of about 150 kg, whereas kangaroos encounter similar problems at a body mass of approximately 35 kg. Tendon strength appears to limit locomotor performance in these animals. Elastic strain energy storage in tendons is mass dependent in all mammals, but exponents are significantly larger in macropodid. Tibial stresses may scale with positive allometry in kangaroos, which result in lower bone safety factors in macropods compared to eutherian mammals.

Porphyromonas loveana sp. nov., isolated from the oral cavity of Australian marsupials.

PubMed

Bird, Philip S; Trott, Darren J; Mikkelsen, Deirdre; Milinovich, Gabriel J; Hillman, Kristine M; Burrell, Paul C; Blackall, Linda L

2016-10-01

An obligatory anaerobic, Gram-stain-negative coccobacillus with black-pigmented colonies was isolated from the oral cavity of selected Australian marsupial species. Phenotypic and molecular criteria showed that this bacterium was a distinct species within the genus Porphyromonas, and was closely related to Porphyromonas gingivalis and Porphyromonas gulae. This putative novel species and P. gulae could be differentiated from P. gingivalis by catalase activity. Further characterization by multi-locus enzyme electrophoresis of glutamate dehydrogenase and malate dehydrogenase enzyme mobility and matrix-assisted laser desorption ionization time-of-flight MS showed that this putative novel species could be differentiated phenotypically from P. gingivalis and P. gulae. Definitive identification by 16S rRNA gene sequencing showed that this bacterium belonged to a unique monophyletic lineage, phylogenetically distinct from P. gingivalis (94.9 % similarity) and P. gulae (95.5 %). This also was supported by 16S-23S rRNA intergenic spacer region and glutamate dehydrogenase gene sequencing. A new species epithet, Porphyromonas loveana sp. nov., is proposed for this bacterium, with DSM 28520T (=NCTC 13658T=UQD444T=MRK101T), isolated from a musky rat kangaroo, as the type strain.

Metabolic effects of cortisol, ACTH, adrenalin and insulin in the marsupial sugar glider, Petaurus breviceps.

PubMed

Bradley, A J; Stoddart, D M

1990-11-01

The effects of cortisol, ACTH, adrenalin and insulin on indices of carbohydrate, fat and protein metabolism were investigated in the conscious marsupial sugar glider Petaurus breviceps. Short-term i.v. infusion of cortisol at dose rates of 0.02, 0.2 and 1.0 mg/kg per h caused the plasma glucose concentration to rise sharply from the normal range of 3.3-4.4 to 8.1-8.7 mmol/l at the end of the infusion period without significant alteration in plasma free fatty acid (FFA), amino acid or urea concentrations. Infusions of ACTH at dose rates of 0.02, 0.06 and 0.45 IU/kg per h caused a similar rise in plasma glucose concentration; however, this was now accompanied by an elevation in plasma FFA concentration, but again without significant changes in either plasma amino acid or urea concentrations. Infusion of adrenalin at 10 micrograms/kg per h caused an increase in the plasma concentrations of both glucose and FFA. Intravenous injections of 0.15 IU insulin/kg caused a rapid and marked decrease in the plasma glucose concentration within 30 min and an increase in the plasma free cortisol concentration. Associated with this change was a marked rise in the plasma concentration of both FFA and free cortisol. The rise in free cortisol was, however, significantly reduced by infusion of glucose. Pretreatment with five daily i.m. injections of 1 mg cortisol acetate/kg, which produced an increase in plasma free cortisol concentration to near the maximum of the physiological range, caused a marked reduction in insulin sensitivity. Cortisol pretreatment caused an increase in the plasma FFA and amino acid concentrations. Petaurus breviceps is highly sensitive to the metabolic effects of glucocorticoids and is similar in this respect to the brush-tailed possum Trichosurus vulpecula. The interactive effects between insulin and glucocorticoids on carbohydrate, fat and protein metabolism in Petaurus breviceps are similar to those shown by Trichosurus vulpecula and some eutherian mammals

Comparative water metabolism of Barrow Island macropodid marsupials: hormonal versus behavioural-dependent mechanisms of body water conservation.

PubMed

King, J M; Bradshaw, S D

2008-01-15

Seasonal variations in rates of water turnover were measured over a 7-year period in four species of macropodid marsupials (Lagorchestes conspicillatus, Bettongia lesueur, Petrogale lateralis and Macropus robustus isabellinus), on Barrow Island off the arid Pilbara coast of Western Australia. These ranged from over 100 mL kg(-0.82) d(-1) in wet seasons to as low as 28.2 mL kg(-0.82) d(-1) in dry seasons in the Spectacled hare wallaby, L. conspicillatus. Plasma osmolality increased significantly in both Barrow Island euros (M. robustus isabellinus) and Spectacled hare wallabies in November 1994, in the driest year yet recorded on the island. In contrast, there was no change in plasma osmolality of the other two species (Black-footed rock wallaby, P. lateralis and Lesueur's burrowing bettong, B. lesueur) that exploit cool and humid thermal refugia such as caves and underground warrens to avoid diurnal temperature extremes. Plasma levels of the marsupial antidiuretic hormone (ADH), lysine vasopressin (LVP), were for the most part below the detectable limit of the assay of 0.41 pg mL(-1) in rock wallabies and bettongs, but reached high levels of 16.7+/-4.6 pg mL(-1) and 20.25+/-5.1 pg mL(-1) in euros and hare wallabies, respectively, in dry seasons. LVP levels were positively correlated with plasma osmolality in both euros and hare wallabies, and negatively correlated with total body water content in euros, supporting its rôle as an antidiuretic hormone in these two species. The study highlights the importance of environmental features, such as caves and underground warrens, which are critical for the long-term survival of endangered species such as the Black-footed rock wallaby and the Lesueur's bettong. These species appear to lack ADH-controlled renal systems for the conservation of body water and are thus dependent on behavioural strategies for the maintenance of fluid homeostasis in arid environments.

Dietary partitioning of Australia's two marsupial hypercarnivores, the Tasmanian devil and the spotted-tailed quoll, across their shared distributional range

PubMed Central

Johnson, Christopher N.; Barmuta, Leon A.; Jones, Menna E.

2017-01-01

Australia’s native marsupial fauna has just two primarily flesh-eating ‘hypercarnivores’, the Tasmanian devil (Sarcophilus harrisii) and the spotted-tailed quoll (Dasyurus maculatus) which coexist only on the island of Tasmania. Devil populations are currently declining due to a fatal transmissible cancer. Our aim was to analyse the diet of both species across their range in Tasmania, as a basis for understanding how devil decline might affect the abundance and distribution of quolls through release from competition. We used faecal analysis to describe diets of one or both species at 13 sites across Tasmania. We compared diet composition and breadth between the two species, and tested for geographic patterns in diets related to rainfall and devil population decline. Dietary items were classified into 6 broad categories: large mammals (≥ 7.0kg), medium-sized mammals (0.5–6.9kg), small mammals (< 0.5kg), birds, reptiles and invertebrates. Diet overlap based on prey-size category was high. Quoll diets were broader than devils at all but one site. Devils consumed more large and medium-sized mammals and quolls more small mammals, reptiles and invertebrates. Medium-sized mammals (mainly Tasmanian pademelon Thylogale billardierii), followed by large mammals (mainly Bennett’s wallaby Macropus rufogriseus) and birds, were the most important prey groups for both species. Diet composition varied across sites, suggesting that both species are flexible and opportunistic foragers, but was not related to rainfall for devils. Quolls included more large mammals but fewer small mammals and invertebrates in their diet in the eastern drier parts of Tasmania where devils have declined. This suggests that a competitive release of quolls may have occurred and the substantial decline of devils has provided more food in the large-mammal category for quolls, perhaps as increased scavenging opportunities. The high diet overlap suggests that if resources become limited in areas of

Strategies of biochemical adaptation for hibernation in a South American marsupial, Dromiciops gliroides: 3. Activation of pro-survival response pathways.

PubMed

Luu, Bryan E; Wijenayake, Sanoji; Zhang, Jing; Tessier, Shannon N; Quintero-Galvis, Julian F; Gaitán-Espitia, Juan Diego; Nespolo, Roberto F; Storey, Kenneth B

2017-12-15

The South American marsupial, monito del monte (Dromiciops gliroides) uses both daily torpor and multi-day hibernation to survive in its southern Chile native environment. The present study leverages multiplex technology to assess the contributions of key stress-inducible cell cycle regulators and heat shock proteins to hibernation in liver, heart, and brain of monito del monte in a comparison of control versus 4day hibernating conditions. The data indicate that MDM2, a stress-responsive ubiquitin ligase, plays a crucial role in marsupial hibernation since all three tissues showed statistically significant increases in MDM2 levels during torpor (1.6-1.8 fold). MDM2 may have a cytoprotective action to deal with ischemia/reperfusion stress and is also involved in a nutrient sensing pathway where it could help regulate the metabolic switch to fatty acid oxidation during torpor. Elevated levels of stress-sensitive cell cycle regulators including ATR (2.32-3.91 fold), and the phosphorylated forms of p-Chk1 (Ser345) (1.92 fold), p-Chk2 (Thr68) (2.20 fold) and p21 (1.64 fold) were observed in heart and liver during hibernation suggesting that the cell cycle is likely suppressed to conserve energy while animals are in torpor. Upregulation of heat shock proteins also occurred as a cytoprotective strategy with increased levels of hsp27 (2.00 fold) and hsp60 (1.72-2.76 fold) during hibernation. The results suggest that cell cycle control and selective chaperone action are significant components of hibernation in D. gliroides and reveal common molecular responses to those seen in eutherian hibernators. Copyright © 2017 Elsevier Inc. All rights reserved.

Similar Associations of Tooth Microwear and Morphology Indicate Similar Diet across Marsupial and Placental Mammals

PubMed Central

Christensen, Hilary B.

2014-01-01

Low-magnification microwear techniques have been used effectively to infer diets within many unrelated mammalian orders, but the extent to which patterns are comparable among such different groups, including long extinct mammal lineages, is unknown. Microwear patterns between ecologically equivalent placental and marsupial mammals are found to be statistically indistinguishable, indicating that microwear can be used to infer diet across the mammals. Microwear data were compared to body size and molar shearing crest length in order to develop a system to distinguish the diet of mammals. Insectivores and carnivores were difficult to distinguish from herbivores using microwear alone, but combining microwear data with body size estimates and tooth morphology provides robust dietary inferences. This approach is a powerful tool for dietary assessment of fossils from extinct lineages and from museum specimens of living species where field study would be difficult owing to the animal’s behavior, habitat, or conservation status. PMID:25099537

Architectonic subdivisions of the amygdalar complex of a primitive marsupial (Didelphis aurita).

PubMed

Rocha-Rego, V; Canteras, N S; Anomal, R F; Volchan, E; Franca, J G

2008-05-15

The architecture of the amygdaloid complex of a marsupial, the opossum Didelphis aurita, was analyzed using classical stains like Nissl staining and myelin (Gallyas) staining, and enzyme histochemistry for acetylcholinesterase and NADPH-diaphorase. Most of the subdivisions of the amygdaloid complex described in eutherian mammals were identified in the opossum brain. NADPH-diaphorase revealed reactivity in the neuropil of nearly all amygdaloid subdivisions with different intensities, allowing the identification of the medial and lateral subdivisions of the cortical posterior nucleus and the lateral subdivision of the lateral nucleus. The lateral, central, basolateral and basomedial nuclei exhibited acetylcholinesterase positivity, which provided a useful chemoarchitectural criterion for the identification of the anterior basolateral nucleus. Myelin stain allowed the identification of the medial subdivision of the lateral nucleus, and resulted in intense staining of the medial subdivisions of the central nucleus. The medial, posterior, and cortical nuclei, as well as the amygdalopiriform area did not exhibit positivity for myelin staining. On the basis of cyto- and chemoarchitectural criteria, the present study highlights that the opossum amygdaloid complex shares similarities with that of other species, thus supporting the idea that the organization of the amygdala is part of a basic plan conserved through mammalian evolution.

Non-invasive evaluation of physiological stress in an iconic Australian marsupial: the Koala (Phascolarctos cinereus).

PubMed

Narayan, Edward J; Webster, Koa; Nicolson, Vere; Mucci, Al; Hero, Jean-Marc

2013-06-15

Koalas (Phascolarctos cinereus) are the only extant representatives of Australia's unique marsupial family Phascolarctidae and were listed as nationally Vulnerable in 2012. Causes of mortality are diverse, although the disease chlamydiosis, dog attacks, collisions with cars, and loss of habitat represent the principal reasons for the continued species decline. Koala breeding facilities in Queensland and New South Wales, Australia have been established for conservation and tourism. Non-invasive monitoring of physiological stress is important for determining the sub-lethal effects of environmental stressors on the well-being, reproduction and survival of Koalas in Zoos and also in the wild. In this study, we developed a faecal cortisol metabolite (FCM) enzyme-immunoassay (EIA) for monitoring physiological stress in Koalas from two established Zoos in Australia and also within a free-living sub-population from Queensland. Biological validation of the FCM EIA was done using an adrenocorticotropic hormone (ACTH) challenge. We discovered excretory lag-times of FCM of 24 h in females (n=2) and 48 h in male (n=2) Koalas in response to the ACTH challenge. FCM levels showed an episodic and delayed peak response lasting up to 9 days post ACTH challenge. This finding should be taken into consideration when designing future experiments to study the impacts of short-term (acute) and chronic stressors on the Koalas. Laboratory validations were done using parallelism and recovery checks (extraction efficiency) of the cortisol standard against pooled Koala faecal extracts. Greater than 99% recovery of the cortisol standard was obtained as well as a parallel displacement curve against Koala faecal extracts. FCM levels of the captive Koalas (n=10 males and 13 females) significantly differed by sex, reproductive condition (lactating versus non-lactating Koalas) and the handling groups. Handled male Koalas had 200% higher FCM levels than their non-handled counterparts, while females

Small mammals from the Chelemhá Cloud Forest Reserve, Alta Verapaz, Guatemala

USGS Publications Warehouse

Matson, Jason O.; Ordóñez-Garza, Nicté; Woodman, Neal; Bulmer, Walter; Eckerlin, Ralph P.; Hanson, J. Delton

2014-01-01

We surveyed the small mammals of remnant mixed hardwood-coniferous cloud forest at elevations ranging from 2,100–2,300 m in the Chelemhá Cloud Forest Reserve, Alta Verapaz, Guatemala. Removal-trapping using a combination of live traps, snap traps, and pitfall traps for 6 days in January 2007 resulted in 175 captures of 15 species of marsupials, shrews, and rodents. This diversity of small mammals is the highest that we have recorded from a single locality of the 10 visited during eight field seasons in the highlands of Guatemala. Based on captures, the most abundant species in the community of small mammals is Peromyscus grandis (n = 50), followed by Handleyomys rhabdops (n = 27), Heteromys desmarestianus(n = 18), Reithrodontomys mexicanus (n = 17), Handleyomys saturatior (n = 16), Sorex veraepacis (n = 15), and Scotinomys teguina (n = 13). The remaining eight species were represented by one to five individuals.

Effects of topographic features on postfire exposed mineral soil in small watersheds

Treesearch

Mariana Dobre; Joan Q. Wu; William J. Elliot; Ina S. Miller; Theresa B. Jain

2014-01-01

Exposed mineral soil is an immediate result of forest fires with direct relevance on surface runoff and soil erosion. The goal of this study was to determine which topographic features influence the distribution of exposed mineral soil following wildfire in forested watersheds. In a field investigation 2 months after a simulated wildfire, ground cover was measured and...

Novel Babesia and Hepatozoon agents infecting non-volant small mammals in the Brazilian Pantanal, with the first record of the tick Ornithodoros guaporensis in Brazil.

PubMed

Wolf, Rafael William; Aragona, Mônica; Muñoz-Leal, Sebastián; Pinto, Leticia Borges; Melo, Andréia Lima Tomé; Braga, Isis Assis; Costa, Jackeliny dos Santos; Martins, Thiago Fernandes; Marcili, Arlei; Pacheco, Richard de Campos; Labruna, Marcelo B; Aguiar, Daniel Moura

2016-04-01

Taking into account the diversity of small terrestrial mammals of the Pantanal, the present study aimed to verify the occurrence of infection by Ehrlichia spp., Anaplasma spp., Rickettsia spp., Hepatozoon spp., Babesia spp. and parasitism by ticks in non-volant small mammals collected in the Brazilian Pantanal. Samples of blood, liver and spleen were collected from 64 captured animals, 22 marsupials and 42 rodents. Pathogen detection was performed by the use of genus-specific Polymerase Chain Reaction (PCR) assays. Ticks collected from the animals consisted of Amblyomma sculptum and Amblyomma triste nymphs, and Ornithodoros guaporensis larvae. None of the vertebrate samples (blood, liver, or spleen) yielded detectable DNA of Rickettsia spp. or Ehrlichia spp. The blood of the rodent Hylaeamys megacephalus yielded an Anaplasma sp. genotype (partial 16S rRNA gene) 99% similar to multiple Anaplasma spp. genotypes around the world. The blood of three rodents of the species Calomys callosus were positive for a novel Hepatozoon sp. agent, phylogenetically related (18S rDNA gene) to distinct Hepatozoon genotypes that have been detected in rodents from different parts of the world. One marsupial (Monodelphis domestica) and three rodents (Thrichomys pachyurus) were positive to novel piroplasmid genotypes, phylogenetically (18S rDNA gene) related to Theileria bicornis, Cytauxzoon manul, and Cytauxzoon felis. The present study provides the first molecular detection of Hepatozoon sp. and piroplasmids in small mammals in Brazil. Additionally, we expanded the distribution of O. guaporensis to Brazil, since this tick species was previously known to occur only in Bolivia. Copyright © 2016 Elsevier GmbH. All rights reserved.

HOXA13 and HOXD13 expression during development of the syndactylous digits in the marsupial Macropus eugenii

PubMed Central

2012-01-01

Background Kangaroos and wallabies have specialised limbs that allow for their hopping mode of locomotion. The hindlimbs differentiate much later in development but become much larger than the forelimbs. The hindlimb autopod has only four digits, the fourth of which is greatly elongated, while digits two and three are syndactylous. We investigated the expression of two genes, HOXA13 and HOXD13, that are crucial for digit patterning in mice during formation of the limbs of the tammar wallaby. Results We describe the development of the tammar limbs at key stages before birth. There was marked heterochrony and the hindlimb developed more slowly than the forelimb. Both tammar HOXA13 and HOXD13 have two exons as in humans, mice and chickens. HOXA13 had an early and distal mRNA distribution in the tammar limb bud as in the mouse, but forelimb expression preceded that in the hindlimb. HOXD13 mRNA was expressed earlier in the forelimb than the hindlimb and was predominantly detected in the interdigital tissues of the forelimb. In contrast, the hindlimb had a more restricted expression pattern that appeared to be expressed at discrete points at both posterior and anterior margins of the limb bud, and was unlike expression seen in the mouse and the chicken. Conclusions This is the first examination of HOXA and HOXD gene expression in a marsupial. The gene structure and predicted proteins were highly conserved with their eutherian orthologues. Interestingly, despite the morphological differences in hindlimb patterning, there were no modifications to the polyalanine tract of either HOXA13 or HOXD13 when compared to those of the mouse and bat but there was a marked difference between the tammar and the other mammals in the region of the first polyserine tract of HOXD13. There were also altered expression domains for both genes in the developing tammar limbs compared to the chicken and mouse. Together these findings suggest that the timing of HOX gene expression may contribute

Molecular evolution of a novel marsupial S100 protein (S100A19) which is expressed at specific stages of mammary gland and gut development.

PubMed

Kwek, Joly H L; Wynne, Alicia; Lefèvre, Christophe; Familari, Mary; Nicholas, Kevin R; Sharp, Julie A

2013-10-01

S100 proteins are calcium-binding proteins involved in controlling diverse intracellular and extracellular processes such as cell growth, differentiation, and antimicrobial function. We recently identified a S100-like cDNA from the tammar wallaby (Macropus eugenii) stomach. Phylogentic analysis shows wallaby S100A19 forms a new clade with other marsupial and monotreme S100A19, while this group shows similarity to eutherian S100A7 and S100A15 genes. This is also supported by amino acid and domain comparisons. We show S100A19 is developmentally-regulated in the tammar wallaby gut by demonstrating the gene is expressed in the forestomach of young animals at a time when the diet consists of only milk, but is absent in older animals when the diet is supplemented with herbage. During this transition the forestomach phenotype changes from a gastric stomach into a fermentation sac and intestinal flora changes with diet. We also show that S100A19 is expressed in the mammary gland of the tammar wallaby only during specific stages of lactation; the gene is up-regulated during pregnancy and involution and not expressed during the milk production phase of lactation. Comparison of the tammar wallaby S100A19 protein sequence with S100 protein sequences from eutherian, monotreme and other marsupial species suggest the marsupial S100A19 has two functional EF hand domains, and an extended His tail. An evolutionary analysis of S100 family proteins was carried out to gain a better understanding of the relationship between the S100 family member functions. We propose that S100A19 gene/protein is the ancestor of the eutherian S100A7 gene/protein, which has subsequently modified its original function in eutherians. This modified function may have arisen due to differentiation of evolutionary pressures placed on gut and mammary gland developmental during mammal evolution. The highly regulated differential expression patterns of S100A19 in the tammar wallaby suggests that S100A19 may play

Investigation into potential transmission sources of Giardia duodenalis in a threatened marsupial (Petrogale penicillata).

PubMed

Vermeulen, Elke T; Ashworth, Deborah L; Eldridge, Mark D B; Power, Michelle L

2015-07-01

Assemblages of the protozoan parasite Giardia duodenalis common in humans and domestic species are increasingly identified in wildlife species, raising concern about the spill-over of pathogens from humans and domestic animals into wildlife. Here, the identity and prevalence of G. duodenalis in populations of a threatened marsupial, the brush-tailed rock-wallaby (Petrogale penicillata), was investigated. Identification of G. duodenalis isolates, across three loci (18S rRNA, β-giardin and gdh), from rock-wallaby fecal samples (n = 318) identified an overall detection rate of 6.3%. No significant difference in G. duodenalis detection was found among captive, wild and supplemented populations. Isolates were assigned to the zoonotic assemblages A and B at 18S rRNA, with sub-assemblages AI and BIV identified at the β-giardin and gdh loci, respectively. Assemblages AI and BIV have previously been identified in human clinical cases, but also in domestic animals and wildlife. The identification of these assemblages in brush-tailed rock-wallabies suggests there are transmission routes of G. duodenalis from humans or other animals to Australian wildlife, both in captivity and in the wild. Copyright © 2015 Elsevier B.V. All rights reserved.

Mitochondrial DNA deletion percentage in sun exposed and non sun exposed skin.

PubMed

Powers, Julia M; Murphy, Gillian; Ralph, Nikki; O'Gorman, Susan M; Murphy, James E J

2016-12-01

The percentages of mitochondrial genomes carrying the mtDNA 3895 and the mtDNA 4977 (common) deletion were quantified in sun exposed and non sun exposed skin biopsies, for five cohorts of patients varying either in sun exposure profile, age or skin cancer status. Non-melanoma skin cancer diagnoses are rising in Ireland and worldwide [12] but most risk prediction is based on subjective visual estimations of sun exposure history. A quantitative objective test for pre-neoplastic markers may result in better adherence to sun protective behaviours. Mitochondrial DNA (mtDNA) is known to be subject to the loss of a significant proportion of specific sections of genetic code due to exposure to ultraviolet light in sunlight. Although one such deletion has been deemed more sensitive, another, called the mtDNA 4977 or common deletion, has proved to be a more useful indicator of possible risk in this study. Quantitative molecular analysis was carried out to determine the percentage of genomes carrying the deletion using non sun exposed and sun exposed skin biopsies in cohorts of patients with high or low sun exposure profiles and two high exposure groups undergoing treatment for NMSC. Results indicate that mtDNA deletions correlate to sun exposure; in groups with high sun exposure habits a significant increase in deletion number in exposed over non sun exposed skin occurred. An increase in deletion percentage was also seen in older cohorts compared to the younger group. The mtDNA 3895 deletion was detected in small amounts in exposed skin of many patients, the mtDNA 4977 common deletion, although present to some extent in non sun exposed skin, is suggested to be the more reliable and easily detected marker. In all cohorts except the younger group with relatively lower sun exposure, the mtDNA 4977 deletion was more frequent in sun exposed skin samples compared to non-sun exposed skin. Copyright © 2016 Elsevier B.V. All rights reserved.

Seasonal changes in the thermoenergetics of the marsupial sugar glider, Petaurus breviceps.

PubMed

Holloway, J C; Geiser, F

2001-11-01

Little information is available on seasonal changes in thermal physiology and energy expenditure in marsupials. To provide new information on the subject, we quantified how body mass, body composition, metabolic rate, maximum heat production, body temperature and thermal conductance change with season in sugar gliders (Petaurus breviceps) held in outdoor aviaries. Sugar gliders increased body mass in autumn to a peak in May/June, which was caused to a large extent by an increase in body fat content. Body mass then declined to minimum values in August/September. Resting metabolic rate both below and above the thermoneutral zone (TNZ) was higher in summer than in winter and the lower critical temperature of the TNZ occurred at a higher ambient temperature (Ta) in summer. The basal metabolic rate was as much as 45% below that predicted from allometric equations for placental mammals and was about 15% lower in winter than in summer. In contrast, maximum heat production was raised significantly by about 20% in winter. This, together with an approximately 20% decrease in thermal conductance, resulted in a 13 degrees C reduction of the minimum effective Ta gliders were able to withstand. Our study provides the first evidence that, despite the apparent lack of functional brown adipose tissue, sugar gliders are able to significantly increase heat production in winter. Moreover, the lower thermoregulatory heat production at most TaS in winter, when food in the wild is scarce, should allow them to reduce energy expenditure.

Ancient expansion of the ribonuclease A superfamily revealed by genomic analysis of placental and marsupial mammals.

PubMed

Cho, Soochin; Zhang, Jianzhi

2006-05-24

Members of the ribonuclease (RNase) A superfamily participate in a diverse array of biological processes, including digestion, angiogenesis, innate immunity, and possibly male reproduction. The superfamily is vertebrate-specific, with 13-20 highly divergent members in primates and rodents, but only a few members in chicken and fish. This has led to the proposal that the superfamily started off from a progenitor with structural similarities to angiogenin and that the superfamily underwent a dramatic expansion during mammalian evolution. To date this evolutionary expansion and understand the functional diversification of the superfamily, we here determine its entire repertoire in the sequenced genomes of dog, cow, and opossum. We identified 7, 20, and 21 putatively functional RNase genes from these three species, respectively. Many of the identified genes are highly divergent from all previously known RNase genes, thus representing new lineages within the superfamily. Phylogenetic analysis indicates that the superfamily expansion predated the separation of placental and marsupial mammals and that differential gene loss and duplication occurred in different species, generating a great variation in gene number and content among extant mammals.

Window contamination on Expose-R

NASA Astrophysics Data System (ADS)

Demets, R.; Bertrand, M.; Bolkhovitinov, A.; Bryson, K.; Colas, C.; Cottin, H.; Dettmann, J.; Ehrenfreund, P.; Elsaesser, A.; Jaramillo, E.; Lebert, M.; van Papendrecht, G.; Pereira, C.; Rohr, T.; Saiagh, K.

2015-01-01

Expose is a multi-user instrument for astrobiological and astrochemical experiments in space. Installed at the outer surface of the International Space Station, it enables investigators to study the impact of the open space environment on biological and biochemical test samples. Two Expose missions have been completed so far, designated as Expose-E (Rabbow et al. 2012) and Expose-R (Rabbow et al. this issue). One of the space-unique environmental factors offered by Expose is full-spectrum, ultraviolet (UV)-rich electromagnetic radiation from the Sun. This paper describes and analyses how on Expose-R, access of the test samples to Solar radiation degraded during space exposure in an unpredicted way. Several windows in front of the Sun-exposed test samples acquired a brown shade, resulting in a reduced transparency in visible light, UV and vacuum UV (VUV). Post-flight investigations revealed the discolouration to be caused by a homogenous film of cross-linked organic polymers at the inside of the windows. The chemical signature varied per sample carrier. No such films were found on windows from sealed, pressurized compartments, or on windows that had been kept out of the Sun. This suggests that volatile compounds originating from the interior of the Expose facility were cross-linked and photo-fixed by Solar irradiation at the rear side of the windows. The origin of the volatiles was not fully identified; most probably there was a variety of sources involved including the biological test samples, adhesives, plastics and printed circuit boards. The outer surface of the windows (pointing into space) was chemically impacted as well, with a probable effect on the transparency in VUV. The reported analysis of the window contamination on Expose-R is expected to help the interpretation of the scientific results and offers possibilities to mitigate this problem on future missions - in particular Expose-R2, the direct successor of Expose-R.

The Role of Subtropical Intrusion in the Development of Typhoon Usagi (5W) 2007

DTIC Science & Technology

2008-03-01

THE MARSUPIAL PARADIGM Summarizing the DMW08 theory, the relevant theoretical paradigm is the formation of a closed proto-vortex or “ embryo ...and begins control its own destiny . By correlating the marsupial analogy for TC formation in this study, we can verify in theory that the remnants...The hurricane embryo . Talk presented at short program workshop entitled Small scale and extreme events: The Hurricane, NSF Institute for Pure and

Auditory laterality in a nocturnal, fossorial marsupial (Lasiorhinus latifrons) in response to bilateral stimuli.

PubMed

Descovich, K A; Reints Bok, T E; Lisle, A T; Phillips, C J C

2013-01-01

Behavioural lateralisation is evident across most animal taxa, although few marsupial and no fossorial species have been studied. Twelve wombats (Lasiorhinus latifrons) were bilaterally presented with eight sounds from different contexts (threat, neutral, food) to test for auditory laterality. Head turns were recorded prior to and immediately following sound presentation. Behaviour was recorded for 150 seconds after presentation. Although sound differentiation was evident by the amount of exploration, vigilance, and grooming performed after different sound types, this did not result in different patterns of head turn direction. Similarly, left-right proportions of head turns, walking events, and food approaches in the post-sound period were comparable across sound types. A comparison of head turns performed before and after sound showed a significant change in turn direction (χ(2) (1)=10.65, p=.001) from a left preference during the pre-sound period (mean 58% left head turns, CI 49-66%) to a right preference in the post-sound (mean 43% left head turns, CI 40-45%). This provides evidence of a right auditory bias in response to the presentation of the sound. This study therefore demonstrates that laterality is evident in southern hairy-nosed wombats in response to a sound stimulus, although side biases were not altered by sounds of varying context.

Strategies of biochemical adaptation for hibernation in a South American marsupial Dromiciops gliroides: 1. Mitogen-activated protein kinases and the cell stress response.

PubMed

Wijenayake, Sanoji; Luu, Bryan E; Zhang, Jing; Tessier, Shannon N; Quintero-Galvis, Julian F; Gaitán-Espitia, Juan Diego; Nespolo, Roberto F; Storey, Kenneth B

2017-12-14

Hibernation is a period of torpor and heterothermy that is typically associated with a strong reduction in metabolic rate, global suppression of transcription and translation, and upregulation of various genes/proteins that are central to the cellular stress response such as protein kinases, antioxidants, and heat shock proteins. The current study examined cell signaling cascades in hibernating monito del monte, Dromiciops gliroides, a South American marsupial of the Order Microbiotheria. Responses to hibernation by members of the mitogen-activated protein kinase (MAPK) pathways, and their roles in coordinating hibernator metabolism were examined in liver, kidney, heart and brain of control and versus hibernating (4days continuous torpor) D. gliroides. The targets evaluated included key protein kinases in their activated phosphorylated forms (p-ERK/MAPK 1/2, p-MEK1, p-MSK1, p-p38, p-JNK) and related target proteins (p-CREB 2, p-ATF2, p-c-Jun and p-p53). Liver exhibited a strong coordinated response by MAPK members to hibernation with significant increases in protein phosphorylation levels of p-MEK1, p-ERK/MAPK1/2, p-MSK1, p-JNK and target proteins c-Jun, and p-ATF2, all combining to signify a strong activation of MAPK signaling during hibernation. Kidney also showed activation of MAPK cascades with significant increases in p-MEK1, p-ERK/MAPK1/2, p-p38, and p-c-Jun levels in hibernating animals. By contrast, responses by heart and brain indicated reduced MAPK pathway function during torpor with reduced phosphorylation of targets including p-ERK/MAPK 1/2 in both tissues as well as lower p-p38 and p-JNK content in heart. Overall, the data indicate a vital role for MAPK signaling in regulating the cell stress response during marsupial hibernation. Copyright © 2017 Elsevier Inc. All rights reserved.

Systematics, biostratigraphy, and dental evolution of the Palaeothentidae, later Oligocene to early-middle Miocene (Deseadan- Santacrucian) caenolestoid marsupials of South America

USGS Publications Warehouse

Bown, T.M.; Fleagle, J.G.

1993-01-01

Fifty-two gnathic and dental characteristics were used to identify the taxonomy and to reconstruct the phylogeny of the Palaeothentidae. Analysis of sequencing of appearances of derived characters documents rampant convergencies at all taxonomic levels and considerable phenotypic plasticity in the organization of the palaeothentid dentition. Certain highly generalized character states survive for the duration of the family in some lineages, whereas others are phenotypically lost for a time and then reappear as a minor percentage of character variability. In general, replacement faunas of palaeothentids were morphologically more generalized than their antecendent forms. Dental character regression indicates that palaeothentids arose prior to the Deseadan from a relatively large-bodied marsupial having generalized tribosphenic molars with more or less bunodont cusps; probably an unknown member of the Didelphidae. -from Authors

Comparative cytogenetics of some marsupial species (Didelphimorphia, Didelphidae) from the Amazon basin

PubMed Central

Silva, Carlos Eduardo Faresin e; de Andrade, Rodrigo Amaral; de Souza, Érica Martinha Silva; Eler, Eduardo Schmidt; da Silva, Maria Nazareth Ferreira; Feldberg, Eliana

2017-01-01

Abstract We investigated the karyotype of 18 didelphid species captured at 13 localities in the Brazilian Amazon, after conventional staining, C-banding, Ag-NOR and fluorescent in situ hybridization (FISH) using the 18S rDNA probe. Variations were found in the X chromosome, heterochromatin distribution and the 18S rDNA sequence. The main variation observed was in the position of the centromere in the X chromosome of Caluromys philander Linnaeus, 1758 and Marmosa murina Linnaeus, 1758. For both species, the X chromosome showed a geographical segregation in the pattern of variation between eastern and western Brazil, with a possible contact area in the central Amazon. C-banding on the X chromosome revealed two patterns for the species of Marmosops Matschie, 1916, apparently without geographic or specific relationships. The nucleolus organizer region (NOR) of all species was confirmed with the 18S rDNA probe, except on the Y chromosome of Monodelphis touan Shaw, 1800. The distribution of this marker varied only in the genus Marmosa Gray, 1821 [M. murina Thomas, 1905 and M. demerarae Thomas, 1905]. Considering that simple NORs are seen as a plesiomorphic character, we conclude that the species Marmosa spp. and Didelphis marsupialis Linnaeus, 1758 evolved independently to the multiple condition. By increasing the sample, using chromosomal banding, and FISH, we verified that marsupials present intra- and interspecific chromosomal variations, which suggests the occurrence of frequent chromosomal rearrangements in the evolution of this group. This observation contrasts with the chromosomal conservatism expected for didelphids. PMID:29114362

Three dimensional digital reconstruction of the jaw adductor musculature of the extinct marsupial giant Diprotodon optatum

PubMed Central

2014-01-01

The morphology and arrangement of the jaw adductor muscles in vertebrates reflects masticatory style and feeding processes, diet and ecology. However, gross muscle anatomy is rarely preserved in fossils and is, therefore, heavily dependent on reconstructions. An undeformed skull of the extinct marsupial, Diprotodon optatum, recovered from Pleistocene sediments at Bacchus Marsh in Victoria, represents the most complete and best preserved specimen of the species offering a unique opportunity to investigate functional anatomy. Computed tomography (CT) scans and digital reconstructions make it possible to visualise internal cranial anatomy and predict location and morphology of soft tissues, including muscles. This study resulted in a 3D digital reconstruction of the jaw adductor musculature of Diprotodon, revealing that the arrangement of muscles is similar to that of kangaroos and that the muscle actions were predominantly vertical. 3D digital muscle reconstructions provide considerable advantages over 2D reconstructions for the visualisation of the spatial arrangement of the individual muscles and the measurement of muscle properties (length, force vectors and volume). Such digital models can further be used to estimate muscle loads and attachment sites for biomechanical analyses. PMID:25165628

Microhabitat of small mammals at ground and understorey levels in a deciduous, southern Atlantic forest.

PubMed

Melo, Geruza L; Miotto, Barbara; Peres, Brisa; Cáceres, Nilton C

2013-01-01

Each animal species selects specific microhabitats for protection, foraging, or micro-climate. To understand the distribution patterns of small mammals on the ground and in the understorey, we investigated the use of microhabitats by small mammals in a deciduous forest of southern Brazil. Ten trap stations with seven capture points were used to sample the following microhabitats: liana, fallen log, ground litter, terrestrial ferns, simple-trunk tree, forked tree, and Piper sp. shrubs. Seven field phases were conducted, each for eight consecutive days, from September 2006 through January 2008. Four species of rodents (Akodon montensis, Sooretamys angouya, Oligoryzomys nigripes and Mus musculus) and two species of marsupials (Didelphis albiventris and Gracilinanus microtarsus) were captured. Captured species presented significant differences on their microhabitat use (ANOVA, p = 0.003), particularly between ground and understorey sites. Akodon montensis selected positively terrestrial ferns and trunks, S. angouya selected lianas, D. albiventris selected fallen trunks and Piper sp., and G. microtarsus choose tree trunks and lianas. We demonstrated that the local small-mammal assemblage does select microhabitats, with different types of associations between species and habitats. Besides, there is a strong evidence of habitat selection in order to diminish predation.

Developmental and Post-Eruptive Defects in Molar Enamel of Free-Ranging Eastern Grey Kangaroos (Macropus giganteus) Exposed to High Environmental Levels of Fluoride

PubMed Central

Kierdorf, Uwe; Death, Clare; Hufschmid, Jasmin; Witzel, Carsten; Kierdorf, Horst

2016-01-01

Dental fluorosis has recently been diagnosed in wild marsupials inhabiting a high-fluoride area in Victoria, Australia. Information on the histopathology of fluorotic marsupial enamel has thus far not been available. This study analyzed the developmental and post-eruptive defects in fluorotic molar enamel of eastern grey kangaroos (Macropus giganteus) from the same high-fluoride area using light microscopy and backscattered electron imaging in the scanning electron microscope. The fluorotic enamel exhibited a brownish to blackish discolouration due to post-eruptive infiltration of stains from the oral cavity and was less resistant to wear than normally mineralized enamel of kangaroos from low-fluoride areas. Developmental defects of enamel included enamel hypoplasia and a pronounced hypomineralization of the outer (sub-surface) enamel underneath a thin rim of well-mineralized surface enamel. While the hypoplastic defects denote a disturbance of ameloblast function during the secretory stage of amelogenesis, the hypomineralization is attributed to an impairment of enamel maturation. In addition to hypoplastic defects, the fluorotic molars also exhibited numerous post-eruptive enamel defects due to the flaking-off of portions of the outer, hypomineralized enamel layer during mastication. The macroscopic and histopathological lesions in fluorotic enamel of M. giganteus match those previously described for placental mammals. It is therefore concluded that there exist no principal differences in the pathogenic mechanisms of dental fluorosis between marsupial and placental mammals. The regular occurrence of hypomineralized, opaque outer enamel in the teeth of M. giganteus and other macropodids must be considered in the differential diagnosis of dental fluorosis in these species. PMID:26895178

Mammary cell-activating factor regulates the hormone-independent transcription of the early lactation protein (ELP) gene in a marsupial.

PubMed

Pharo, Elizabeth A; Renfree, Marilyn B; Cane, Kylie N

2016-11-15

The regulation of the tammar wallaby (Macropus eugenii) early lactation protein (ELP) gene is complex. ELP is responsive to the lactogenic hormones; insulin (I), hydrocortisone (HC) and prolactin (PRL) in mammary gland explants but could not be induced with lactogenic hormones in tammar primary mammary gland cells, nor in KIM-2 conditionally immortalised murine mammary epithelial cells. Similarly, ELP promoter constructs transiently-transfected into human embryonic kidney (HEK293T) cells constitutively expressing the prolactin receptor (PRLR) and Signal Transducer and Activator of Transcription (STAT)5A were unresponsive to prolactin, unlike the rat and mouse β-casein (CSN2) promoter constructs. Identification of the minimal promoter required for the hormone-independent transcription of tammar ELP in HEK293Ts and comparative analysis of the proximal promoters of marsupial ELP and the orthologous eutherian colostrum trypsin inhibitor (CTI) gene suggests that mammary cell-activating factor (MAF), an E26 transformation-specific (ETS) factor, may bind to an AGGAAG motif and activate tammar ELP. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

3 EXPOSE Missions - overview and lessons learned

NASA Astrophysics Data System (ADS)

Rabbow, E.; Willnekcer, R.; Reitz, G.; Aman, A.; Bman, B.; Cman, C.

2011-10-01

The International Space Station ISS provides a variety of external research platforms for experiments aiming at the utilization of space parameters like vacuum, temperature oscillation and in particular extraterrestrial short wavelength UV and ionizing radiation which cannot be simulated accurately in the laboratory. Three Missions, two past and one upcoming, will be presented. A family of astrobiological experimental ESA facilities called "EXPOSE" were and will be accommodated on these outside exposure platforms: on one of the external balconies of the European Columbus Module (EXPOSE-E) and on the URM-D platform on the Russian Zvezda Module (EXPOSE-R and EXPOSE-R2). Exobiological and radiation experiments, exposing chemical, biological and dosimetric samples to the harsh space environment are - and will be - accommodated on these facilities to increase our knowledge on the origin, evolution and distribution of life, on Earth and possibly beyond. The biological experiments investigate resistance and adaptation of organisms like bacteria, Achaea, fungi, lichens, plant seeds and small animals like mosquito larvae to extreme environmental conditions and underlying mechanisms like DNA repair. The organic chemical experiments analyse chemical reactions triggered by the extraterrestrial environment, especially short wavelength UV radiation, to better understand prebiotic chemistry. The facility is optimized to allow exposure of biological specimen and material samples under a variety of conditions, using optical filter systems. Environmental parameters like temperature and radiation are regularly recorded and down linked by telemetry. Two long term missions named according to their facility - EXPOSE-E and EXPOSE-R - are completed and a third mission is planned and currently prepared. Operations of all three missions including sample accommodation are performed by DLR. An overview of the two completed missions will be given including lessons learned as well as an outlook

EXPOSE-R on Mission on the ISS

NASA Astrophysics Data System (ADS)

Panitz, Corinna; Rabbow, Elke; Rettberg, Petra; Barczyk, Simon; Kloss, Maria; Reitz, Guenther

Currently EXPOSE-R is on mission! This astrobiological exposure facility was accommodated at the universal workplace URM-D Zenith payload site, located outside the Russian Svezda Module of the International Space Station (ISS) by extravehicular activity (EVA) on March 10th 2009. It contains 3 trays accommodating 12 sample compartments with sample carriers in three levels either open to space vacuum or kept in a defined gas environment. In its 8 experiments of biological and chemical content, more than 1200 individual samples are exposed to solar ultraviolet (UV) radiations, vacuum, cosmic rays or extreme temperature variations. In their different experiments the involved scientists are studying the question of life's origin on Earth and the results of their experiments are contributing to different aspects of the evolution and distribution of life in the Universe. Additionally integrated into the EXPOSE-R facility are several dosimeters monitoring the ionising and the solar UV-radiation during the mission to deliver useful information to complement the sample analysis. In close cooperation with the DLR and the Technical University Munich (TUM), the Rheinisch -Westfülische Technischen Hochschule Aachen (RWTH Aachen) operates the experiment "Spores". a This is one of the 6 astrobiological experiments of the ROSE-Consortium" (Response of Or-ganisms to Space Environment) of the EXPOSE-R mission. In these experiments spores of bacteria, fungi and ferns are being over layered or mixed with meteorite material. The analysis of the effect of the space parameters on different biological endpoints of the spores of the mi-croorganism Bacillus subtilis will be performed after the retrieval of the experiment scheduled for the end of 2010. Parallel to the space mission an identical set of samples was accommodated into EXPOSE-R trays identical in construction to perform the Mission Ground Reference (MGR) Test. Currently this MGR Test is carried out in the Planetary and Space

ARX/Arx is expressed in germ cells during spermatogenesis in both marsupial and mouse.

PubMed

Yu, Hongshi; Pask, Andrew J; Hu, Yanqiu; Shaw, Geoff; Renfree, Marilyn B

2014-03-01

The X-linked aristaless gene, ARX, is essential for the development of the gonads, forebrain, olfactory bulb, pancreas, and skeletal muscle in mice and humans. Mutations cause neurological diseases, often accompanied by ambiguous genitalia. There are a disproportionately high number of testis and brain genes on the human and mouse X chromosomes. It is still unknown whether the X chromosome accrued these genes during its evolution or whether genes that find themselves on the X chromosome evolve such roles. ARX was originally autosomal in mammals and remains so in marsupials, whereas in eutherian mammals it translocated to the X chromosome. In this study, we examined autosomal ARX in tammars and compared it with the X-linked Arx in mice. We detected ARX mRNA in the neural cells of the forebrain, midbrain and hindbrain, and olfactory bulbs in developing tammars, consistent with the expression in mice. ARX was detected by RT-PCR and mRNA in situ hybridization in the developing tammar wallaby gonads of both sexes, suggestive of a role in sexual development as in mice. We also detected ARX/Arx mRNA in the adult testis in both tammars and mice, suggesting a potential novel role for ARX/Arx in spermiogenesis. ARX transcripts were predominantly observed in round spermatids. Arx mRNA localization distributions in the mouse adult testis suggest that it escaped meiotic sex chromosome inactivation during spermatogenesis. Our findings suggest that ARX in the therian mammal ancestor already played a role in male reproduction before it was recruited to the X chromosome in eutherians.

Embryo-endometrial interactions during early development after embryonic diapause in the marsupial tammar wallaby.

PubMed

Renfree, Marilyn B; Shaw, Geoff

2014-01-01

The marsupial tammar wallaby has the longest period of embryonic diapause of any mammal. Reproduction in the tammar is seasonal, regulated by photoperiod and also lactation. Reactivation is triggered by falling daylength after the austral summer solstice in December. Young are born late January and commence a 9-10-month lactation. Females mate immediately after birth. The resulting conceptus develops over 6- 7 days to form a unilaminar blastocyst of 80-100 cells and enters lactationally, and later seasonally, controlled diapause. The proximate endocrine signal for reactivation is an increase in progesterone which alters uterine secretions. Since the diapausing blastocyst is surrounded by the zona and 2 other acellular coats, the mucoid layer and shell coat, the uterine signals that maintain or terminate diapause must involve soluble factors in the secretions rather than any direct cellular interaction between uterus and embryo. Our studies suggest involvement of a number of cytokines in the regulation of diapause in tammars. The endometrium secretes platelet activating factor (PAF) and leukaemia inhibitory factor, which increase after reactivation. Receptors for PAF are low on the blastocyst during diapause but are upregulated at reactivation. Conversely, there is endometrial expression of the muscle segment homeobox gene MSX2 throughout diapause, but it is rapidly downregulated at reactivation. These patterns are consistent with those observed in diapausing mice and mink after reactivation, despite the very different patterns of endocrine control of diapause in these 3 divergent species. These common patterns suggest a similar underlying mechanism for diapause, perhaps common to all mammals, but which is activated in only a few.

Thermoregulatory value of cracking-clay soil shelters for small vertebrates during extreme desert conditions.

PubMed

Waudby, Helen P; Petit, Sophie

2017-05-01

Deserts exhibit extreme climatic conditions. Small desert-dwelling vertebrates have physiological and behavioral adaptations to cope with these conditions, including the ability to seek shelter. We investigated the temperature (T) and relative humidity (RH) regulating properties of the soil cracks that characterize the extensive cracking-clay landscapes of arid Australia, and the extent of their use by 2 small marsupial species: fat-tailed and stripe-faced dunnarts (Sminthopsis crassicaudata and Sminthopsis macroura). We measured hourly (over 24-h periods) the T and RH of randomly-selected soil cracks compared to outside conditions, during 2 summers and 2 winters. We tracked 17 dunnarts (8 Sminthopsis crassicaudata and 9 Sminthopsis macroura) to quantify their use of cracks. Cracks consistently moderated microclimate, providing more stable conditions than available from non-crack points, which often displayed comparatively dramatic fluctuations in T and RH. Both dunnart species used crack shelters extensively. Cracks constitute important shelter for small animals during extreme conditions by providing a stable microclimate, which is typically cooler than outside conditions in summer and warmer in winter. Cracks likely play a fundamental sheltering role by sustaining the physiological needs of small mammal populations. Globally, cracking-clay areas are dominated by agricultural land uses, including livestock grazing. Management of these systems should focus not only on vegetation condition, but also on soil integrity, to maintain shelter resources for ground-dwelling fauna. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

The X chromosome of monotremes shares a highly conserved region with the eutherian and marsupial X chromosomes despite the absence of X chromosome inactivation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, J.M.; Spencer, J.A.; Graves, J.A.M.

1990-09-01

Eight genes, located on the long arm of the human X chromosome and present on the marsupial X chromosome, were mapped by in situ hybridization to the chromosomes of the platypus Ornithorhynchus anatinus, one of the three species of monotreme mammals. All were located on the X chromosome. The authors conclude that the long arm of the human X chromosome represents a highly conserved region that formed part of the X chromosome in a mammalian ancestor at least 150 million years ago. Since three of these genes are located on the long arm of the platypus X chromosome, which ismore » G-band homologous to the Y chromosome and apparently exempt from X chromosome inactivation, the conservation of this region has evidently not depended on isolation by X-Y chromosome differentiation and X chromosome inactivation.« less

Geographic Variation in Daily Temporal Activity Patterns of a Neotropical Marsupial (Gracilinanus agilis)

PubMed Central

Vieira, Emerson M.; de Camargo, Nícholas F.; Colas, Paul F.; Ribeiro, Juliana F.; Cruz-Neto, Ariovaldo P.

2017-01-01

The temporal activity of animals is an outcome of both biotic and abiotic factors, which may vary along the geographic range of the species. Therefore, studies conducted with a species in different localities with distinct features could elucidate how animals deal with such factors. In this study, we used live traps equipped with timing devices to investigate the temporal activity patterns of the didelphid Gracilinanus agilis in two dry-woodland areas of the Brazilian savanna (Cerrado). These areas were located about 660 km apart, one in Central Brazil and the other in Southeastern Brazil. We compared such patterns considering both reproductive and non-reproductive periods, and how it varies as a function of temperature on a seasonal basis. In Central Brazil, we found a constant, and temperature-independent activity during the night in both reproductive and non-reproductive periods. On the other hand, in Southeastern Brazil, we detected a constant activity during the reproductive period, but in the non-reproductive period G. agilis presented a peak of activity between two and four hours after sunset. Moreover, in this latter we found a relation between temporal activity and temperature during the autumn and spring. These differences in temporal activity between areas, observed during the non-reproductive period, might be associated with the higher seasonal variability in temperature, and lower mean temperatures in the Southeastern site in comparison to the Central one. In Southeastern Brazil, the decrease in temperature during the non-reproductive season possibly forced G. agilis to be active only at certain hours of the night. However, likely due to the reproductive activities (intensive foraging and searching for mates) this marsupial showed constant, temperature-independent activity during the night in the reproductive period at both sites. PMID:28052077

Extensive genetic differentiation detected within a model marsupial, the tammar wallaby (Notamacropus eugenii)

PubMed Central

Miller, Emily J.; Neaves, Linda E.; Zenger, Kyall R.; Herbert, Catherine A.

2017-01-01

The tammar wallaby (Notamacropus eugenii) is one of the most intensively studied of all macropodids and was the first Australasian marsupial to have its genome sequenced. However, comparatively little is known about genetic diversity and differentiation amongst the morphologically distinct allopatric populations of tammar wallabies found in Western (WA) and South Australia (SA). Here we compare autosomal and Y-linked microsatellite genotypes, as well as sequence data (~600 bp) from the mitochondrial DNA (mtDNA) control region (CR) in tammar wallabies from across its distribution. Levels of diversity at autosomal microsatellite loci were typically high in the WA mainland and Kangaroo Island (SA) populations (A = 8.9–10.6; He = 0.77–0.78) but significantly reduced in other endemic island populations (A = 3.8–4.1; He = 0.41–0.48). Autosomal and Y-linked microsatellite loci revealed a pattern of significant differentiation amongst populations, especially between SA and WA. The Kangaroo Island and introduced New Zealand population showed limited differentiation. Multiple divergent mtDNA CR haplotypes were identified within both SA and WA populations. The CR haplotypes of tammar wallabies from SA and WA show reciprocal monophyly and are highly divergent (14.5%), with levels of sequence divergence more typical of different species. Within WA tammar wallabies, island populations each have unique clusters of highly related CR haplotypes and each is most closely related to different WA mainland haplotypes. Y-linked microsatellite haplotypes show a similar pattern of divergence although levels of diversity are lower. In light of these differences, we suggest that two subspecies of tammar wallaby be recognized; Notamacropus eugenii eugenii in SA and N. eugenii derbianus in WA. The extensive neutral genetic diversity and inter-population differentiation identified within tammar wallabies should further increase the species value and usefulness as a model organism. PMID

Gene expression changes in human small airway epithelial cells exposed to Delta9-tetrahydrocannabinol.

PubMed

Sarafian, Theodore; Habib, Nancy; Mao, Jenny T; Tsu, I-Hsien; Yamamoto, Mitsuko L; Hsu, Erin; Tashkin, Donald P; Roth, Michael D

2005-08-14

Marijuana smoking is associated with inflammation, cellular atypia, and molecular dysregulation of the tracheobronchial epithelium. While marijuana smoke shares many components in common with tobacco, it also contains a high concentration of Delta9-tetrahydrocannabinol (THC). The potential contribution of THC to airway injury was assessed by exposing primary cultures of human small airway epithelial (SAE) cells to THC (0.1-10.0 microg/ml) for either 1 day or 7 days. THC induced a time- and concentration-dependent decrease in cell viability, ATP level, and mitochondrial membrane potential. Using a targeted gene expression array, we observed acute changes (24 h) in the expression of mRNA for caspase-8, catalase, Bax, early growth response-1, cytochrome P4501A1 (CYP1A1), metallothionein 1A, PLAB, and heat shock factor 1 (HSF1). After 7 days of exposure, decrease in expression of mRNA for heat shock proteins (HSPs) and the pro-apoptotic protein Bax was observed, while expression of GADD45A, IL-1A, CYP1A1, and PTGS-2 increased significantly. These findings suggest a contribution of THC to DNA damage, inflammation, and alterations in apoptosis. Treatment with selected prototypical toxicants, 2,3,7,8-tetrachlorodibenznzo-p-dioxin (TCDD) and carbonyl cyanide-p-(trifluoramethoxy)-phenyl hydrazone (FCCP), produced partially overlapping gene expression profiles suggesting some similarity in mechanism of action with THC. THC, delivered as a component of marijuana smoke, may induce a profile of gene expression that contributes to the pulmonary pathology associated with marijuana use.

Pliocene Paleoenvironments of Southeastern Queensland, Australia Inferred from Stable Isotopes of Marsupial Tooth Enamel

PubMed Central

Montanari, Shaena; Louys, Julien; Price, Gilbert J.

2013-01-01

The Chinchilla Local Fauna is a diverse assemblage of both terrestrial and aquatic Pliocene vertebrates from the fluviatile Chinchilla Sand deposits of southeastern Queensland, Australia. It represents one of Australia's few but exceptionally rich Pliocene vertebrate localities, and as such is an important source of paleoecological data concerning Pliocene environmental changes and its effects on ecosystems. Prior inferences about the paleoenvironment of this locality made on the basis of qualitative observations have ranged from grassland to open woodland to wetland. Examination of the carbon and oxygen isotopes in the tooth enamel of marsupials from this site represents a quantitative method for inferring the paleoenvironments and paleoecology of the fossil fauna. Results from Chinchilla show that Protemnodon sp. indet. consumed both C3 and C4 photosynthesis plant types (mean δ13C = −14.5±2.0‰), and therefore probably occupied a mixed vegetation environment. Macropus sp. indet. from Chinchilla also consumed a mixed diet of both C3 and C4 plants, with more of a tendency for C4 plant consumption (mean δ13C = −10.3±2.3‰). Interestingly, their isotopic dietary signature is more consistent with tropical and temperate kangaroo communities than the sub-tropical communities found around Chinchilla today. Other genera sampled in this study include the extinct kangaroo Troposodon sp. indet. and the fossil diprotodontid Euryzygoma dunense each of which appear to have occupied distinct dietary niches. This study suggests that southeastern Queensland hosted a mosaic of tropical forests, wetlands and grasslands during the Pliocene and was much less arid than previously thought. PMID:23776636

Commissurotomy for improving access to the oral cavity of the wombat.

PubMed

Wilson, G J; Gillett, A

2010-07-01

Wombats are a grazing marsupial with a diet rich in silicates, which is highly abrasive and results in a higher rate of tooth attrition than in other grazing marsupials such as kangaroos. Any interference in the natural wear process, such as malocclusion or loss of teeth, causes overgrowth of teeth. The small mouth opening of the wombat makes access to the caudal mouth difficult and overgrowth of cheek teeth can be difficult to treat effectively. This case report describes a technique that greatly improves access to allow dental treatment of all overgrown teeth with minimal complications.

Signs and symptoms of mercury-exposed gold miners.

PubMed

Bose-O'Reilly, Stephan; Bernaudat, Ludovic; Siebert, Uwe; Roider, Gabriele; Nowak, Dennis; Drasch, Gustav

2017-03-30

Gold miners use mercury to extract gold from ore adding liquid mercury to the milled gold-containing ore. This results in a mercury-gold compound, called amalgam. Miners smelt this amalgam to obtain gold, vaporizing it and finally inhaling the toxic mercury fumes. The objective was to merge and analyze data from different projects, to identify typical signs and symptoms of chronic inorganic mercury exposure. Miners and community members from various artisanal small-scale gold mining areas had been examined (Philippines, Mongolia, Tanzania, Zimbabwe, Indonesia). Data of several health assessments were pooled. Urine, blood and hair samples were analyzed for mercury (N = 1252). Questionnaires, standardized medical examinations and neuropsychological tests were used. Participants were grouped into: Controls (N = 209), living in an exposed area (N = 408), working with mercury as panners (N = 181), working with mercury as amalgam burners (N = 454). Chi² test, linear trend test, Mann-Whitney test, Kruskal-Wallis test, correlation coefficient, Spearman's rho, and analysis of variance tests were used. An algorithm was used to define participants with chronic mercury intoxication. Mean mercury concentrations in all exposed subgroups were elevated and above threshold limits, with amalgam burners showing highest levels. Typical symptoms of chronic metallic mercury intoxication were tremor, ataxia, coordination problems, excessive salivation and metallic taste. Participants from the exposed groups showed poorer results in different neuropsychological tests in comparison to the control group. Fifty-four percent of the high-exposed group (amalgam burners) were diagnosed as being mercury-intoxicated, compared to 0% within the control group (Chi² p < 0.001). Chronic mercury intoxication, with tremor, ataxia and other neurological symptoms together with a raised body burden of mercury was clinically diagnosed in exposed people in artisanal small-scale mining

Teleoperated Marsupial Mobile Sensor Platform Pair for Telepresence Insertion Into Challenging Structures

NASA Technical Reports Server (NTRS)

Krasowski, Michael J.; Prokop, Norman F.; Greer, Lawrence C.

2011-01-01

A platform has been developed for two or more vehicles with one or more residing within the other (a marsupial pair). This configuration consists of a large, versatile robot that is carrying a smaller, more specialized autonomous operating robot(s) and/or mobile repeaters for extended transmission. The larger vehicle, which is equipped with a ramp and/or a robotic arm, is used to operate over a more challenging topography than the smaller one(s) that may have a more limited inspection area to traverse. The intended use of this concept is to facilitate the insertion of a small video camera and sensor platform into a difficult entry area. In a terrestrial application, this may be a bus or a subway car with narrow aisles or steep stairs. The first field-tested configuration is a tracked vehicle bearing a rigid ramp of fixed length and width. A smaller six-wheeled vehicle approximately 10 in. (25 cm) wide by 12 in. (30 cm) long resides at the end of the ramp within the larger vehicle. The ramp extends from the larger vehicle and is tipped up into the air. Using video feedback from a camera atop the larger robot, the operator at a remote location can steer the larger vehicle to the bus door. Once positioned at the door, the operator can switch video feedback to a camera at the end of the ramp to facilitate the mating of the end of the ramp to the top landing at the upper terminus of the steps. The ramp can be lowered by remote control until its end is in contact with the top landing. At the same time, the end of the ramp bearing the smaller vehicle is raised to minimize the angle of the slope the smaller vehicle has to climb, and further gives the operator a better view of the entry to the bus from the smaller vehicle. Control is passed over to the smaller vehicle and, using video feedback from the camera, it is driven up the ramp, turned oblique into the bus, and then sent down the aisle for surveillance. The demonstrated vehicle was used to scale the steps leading to

Post-fire recovery of torpor and activity patterns of a small mammal.

PubMed

Stawski, Clare; Hume, Taylor; Körtner, Gerhard; Currie, Shannon E; Nowack, Julia; Geiser, Fritz

2017-05-01

To cope with the post-fire challenges of decreased availability of food and shelter, brown antechinus ( Antechinus stuartii ), a small marsupial mammal, increase the use of energy-conserving torpor and reduce activity. However, it is not known how long it takes for animals to resume pre-fire torpor and activity patterns during the recovery of burnt habitat. Therefore, we tested the hypothesis that antechinus will adjust torpor use and activity after a fire depending on vegetation recovery. We simultaneously quantified torpor and activity patterns for female antechinus from three adjacent areas: (i) the area of a management burn 1 year post-fire, (ii) an area that was burned 2 years prior, and (iii) a control area. In comparison to shortly after the management burn, antechinus in all three groups displayed less frequent and less pronounced torpor while being more active. We provide the first evidence that only 1 year post-fire antechinus resume pre-fire torpor and activity patterns, probably in response to the return of herbaceous ground cover and foraging opportunities. © 2017 The Author(s).

The value of eutherian-marsupial comparisons for understanding the function of glucocorticoids in female mammal reproduction.

PubMed

Fanson, Kerry V; Parrott, Marissa L

2015-11-01

This article is part of a Special Issue "SBN 2014". Chronic stress is known to inhibit female reproductive function. Consequently, it is often assumed that glucocorticoid (GC) concentrations should be negatively correlated with reproductive success because of the role they play in stress physiology. In contrast, a growing body of evidence indicates that GCs play an active role in promoting reproductive function. It is precisely because GCs are so integral to the entire process that disruptions to adrenal activity have negative consequences for reproduction. The goal of this paper is to draw attention to the increasing evidence showing that increases in adrenal activity are important for healthy female reproduction. Furthermore, we outline several hypotheses about the functional role(s) that GCs may play in mediating reproduction and argue that comparative studies between eutherian and marsupial mammals, which exhibit some pronounced differences in reproductive physiology, may be particularly useful for testing different hypotheses about the functional role of GCs in reproduction. Much of our current thinking about GCs and reproduction comes from research involving stress-induced levels of GCs and has led to broad assumptions about the effects of GCs on reproduction. Unfortunately, this has left a gaping hole in our knowledge about basal GC levels and how they may influence reproductive function, thereby preventing a broader understanding of adrenal physiology and obscuring potential solutions for reproductive dysfunction. Copyright © 2015 Elsevier Inc. All rights reserved.

Differential pattern of deposition of nanoparticles in the airways of exposed workers

NASA Astrophysics Data System (ADS)

Fireman, Elizabeth; Edelheit, Rinat; Stark, Moshe; Shai, Amir Bar

2017-02-01

Ultrafine particles (UFP) have been postulated to significantly contribute to the adverse health effects associated with exposure to particulate matter (PM). Due to their extremely small size (aerodynamic diameter <100 nm), UFP are able to deposit deep within the lung after inhalation and evade many mechanisms responsible for the clearance of larger particles. There is a lack of biologically relevant personal exposure metrics for exposure to occupational- and environmental-related micro- and nano-sized PM. The aim of the present study is to assess UFP in induced sputum (IS) and exhaled breath condensate (EBC) as possible biomarkers for assessing lung function impairment. Sputum induction and EBC testing were performed by conventional methods. UFP particles were assessed with the NanoSight LM20 (NanoSight Ltd, London, UK). The subjects included 35 exposed and 25 non-exposed workers. There were no group differences in pulmonary function test results and differential cell counts, but 63.6% of the exposed subjects had a higher percentage of neutrophils (OR3.28 p = 0.03) compared to the non-exposed subjects. The exposed subjects had higher percentages of UFP between 10 and 50 nm (69.45 ± 18.70 vs 60.11 ± 17.52 for the non-exposed group, p = 0.004). No differences were found in the IS samples. Years of exposure correlated positively to UFP content ( r = 0.342 p = 0.01) and macrophage content ( r = -0.327 p = 0.03). The percentage of small fraction of UFP in EBC, but not IS, is higher in exposed workers, and EBC may be a sensitive biomarker to assess exposure to nanoparticles.

Small mammals taphonomy and environmental evolution during Late Pleistocene-Holocene in Monte Desert: The evidence of Gruta del Indio (central west Argentina)

NASA Astrophysics Data System (ADS)

Fernández, Fernando J.; Pardiñas, Ulyses F. J.

2018-07-01

Very few excavated sequences in southern South America provide an approximation to the environmental evolution covering the segment Late Pleistocene-Holocene. Here we present the taphonomic analysis and paleoenvironmental reconstruction based on the small mammal remains retrieved from the archaeological and paleontological site Gruta del Indio (Mendoza Province, Argentina). Radiocarbon dates situate the small mammal deposits studied within the Late Pleistocene and Holocene. Thus, these assemblages provide a record for inferring environmental evolution in the middle basin of Atuel River during the last ∼31 ky BP. Taphonomic analysis revealed that most of small mammal remains were incorporated by a little destructive nocturnal owl. Recorded species include mainly cricetid and caviomorph rodents and a single marsupial. While Pleistocene assemblages have not exclusive species, the specific richness increases towards the Holocene probably linked with the climatic variability related to ENSO. In overall, the recorded small mammals suggest environmental stability during the Late Pleistocene-Holocene, mostly associated with Monte Desert conditions. Conversely, the pollen sequence studied from Gruta del Indio was interpreted as indicator of a deep environmental change during the Pleistocene-Holocene transition, when the Patagonian steppe was replaced by Monte Desert. Potential biases linked with these kinds of proxies are discussed.

Surface friction alters the agility of a small Australian marsupial.

PubMed

Wheatley, Rebecca; Clemente, Christofer J; Niehaus, Amanda C; Fisher, Diana O; Wilson, Robbie S

2018-04-23

Movement speed can underpin an animal's probability of success in ecological tasks. Prey often use agility to outmanoeuvre predators; however, faster speeds increase inertia and reduce agility. Agility is also constrained by grip, as the foot must have sufficient friction with the ground to apply the forces required for turning. Consequently, ground surface should affect optimum turning speed. We tested the speed-agility trade-off in buff-footed antechinus ( Antechinus mysticus ) on two different surfaces. Antechinus used slower turning speeds over smaller turning radii on both surfaces, as predicted by the speed-agility trade-off. Slipping was 64% more likely on the low-friction surface, and had a higher probability of occurring the faster the antechinus were running before the turn. However, antechinus compensated for differences in surface friction by using slower pre-turn speeds as their amount of experience on the low-friction surface increased, which consequently reduced their probability of slipping. Conversely, on the high-friction surface, antechinus used faster pre-turn speeds in later trials, which had no effect on their probability of slipping. Overall, antechinus used larger turning radii (0.733±0.062 versus 0.576±0.051 m) and slower pre-turn (1.595±0.058 versus 2.174±0.050 m s -1 ) and turning speeds (1.649±0.061 versus 2.01±0.054 m s -1 ) on the low-friction surface. Our results demonstrate the interactive effect of surface friction and the speed-agility trade-off on speed choice. To predict wild animals' movement speeds, future studies should examine the interactions between biomechanical trade-offs and terrain, and quantify the costs of motor mistakes in different ecological activities. © 2018. Published by The Company of Biologists Ltd.

Coccidial dispersion across New World marsupials: Klossiella tejerai Scorza, Torrealba & Dagert, 1957 (Apicomplexa: Adeleorina) from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) (Mammalia: Didelphimorphia).

PubMed

Dos Santos, Caroline Spitz; Berto, Bruno Pereira; do Bomfim Lopes, Bruno; Cordeiro, Matheus Dias; da Fonseca, Adivaldo Henrique; Filho, Walter Leira Teixeira; Lopes, Carlos Wilson Gomes

2014-09-01

Klossiella tejerai Scorza, Torrealba & Dagert, 1957 is a primitive coccidian parasite reported from the New World marsupials Didelphis marsupialis (Linnaeus) and Marmosa demerarae (Thomas). The current work describes K. tejerai from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) in Southeastern Brazil, evidencing the coccidial dispersion across opossums of the same family. The sporocysts recovered from urine samples were ellipsoidal, 20.4 × 12.7 µm, with sporocyst residuum composed of scattered spherules and c.13 sporozoites per sporocyst, with refractile bodies and nucleus. Macrogametes, microgametes, sporonts, sporoblasts/sporocysts were identified within parasitophorous vacuoles of epithelial cells located near the renal corticomedullary junction. Didelphis marsupialis should not have transmitted K. tejerai to D. aurita because they are not sympatric; however M. demerarae is sympatric with D. marsupialis and D. aurita. Therefore, D. aurita becomes the third host species for K. tejerai in South America.

A small scale survey of Leptospira in mammals from eastern Poland.

PubMed

Wójcik-Fatla, Angelina; Zając, Violetta; Sroka, Jacek; Piskorski, Michał; Cisak, Ewa; Sawczyn, Anna; Dutkiewicz, Jacek

2013-01-01

Samples of 30 dead small mammals each were collected on area 'A' located in eastern Poland and exposed to floods by the Vistula river, and on area 'B', also located in eastern Poland, but not exposed to floods. Kidneys and livers of the mammals were examined by the PCR and nested PCR methods for the presence of Leptospira DNA. From 7 species of small mammals examined, the presence of Leptospira DNA was detected in 2 of them. The prevalence of positive results was greatest in Apodemus agrarius which was the mostly numerous mammal species (14 out of total 39 specimens, 35.9%). The presence of Leptospira DNA was also found in Microtus arvalis (1 out of 1 specimen, 100%), whereas the remaining 5 species (Apodemus flavicollis , Apodemus sylvaticus, Microtus agrestis, Myodes glareolus, Sorex araneus) were negative. No significant difference in the prevalence of positive findings was found between the small mammals from areas 'A' exposed to flooding, compared to those from area 'B' not exposed to flooding (20.0% vs. 30.0%, p=0.3748). The overall positivity of the examined small mammals population from areas 'A' and 'B' was 25.0%. The prevalence of dual positivity (leptospiral DNA found both in kidney and liver) was greater in the mammals from areas exposed to flooding compared to those from areas not exposed to flooding (16.7% vs. 6.7%), but this dependence was also not significant (p=0.2382).

Rate of evolutionary change in cranial morphology of the marsupial genus Monodelphis is constrained by the availability of additive genetic variation

PubMed Central

Porto, Arthur; Sebastião, Harley; Pavan, Silvia Eliza; VandeBerg, John L.; Marroig, Gabriel; Cheverud, James M.

2015-01-01

We tested the hypothesis that the rate of marsupial cranial evolution is dependent on the distribution of genetic variation in multivariate space. To do so, we carried out a genetic analysis of cranial morphological variation in laboratory strains of Monodelphis domestica and used estimates of genetic covariation to analyze the morphological diversification of the Monodelphis brevicaudata species group. We found that within-species genetic variation is concentrated in only a few axes of the morphospace and that this strong genetic covariation influenced the rate of morphological diversification of the brevicaudata group, with between-species divergence occurring fastest when occurring along the genetic line of least resistance. Accounting for the geometric distribution of genetic variation also increased our ability to detect the selective regimen underlying species diversification, with several instances of selection only being detected when genetic covariances were taken into account. Therefore, this work directly links patterns of genetic covariation among traits to macroevolutionary patterns of morphological divergence. Our findings also suggest that the limited distribution of Monodelphis species in morphospace is the result of a complex interplay between the limited dimensionality of available genetic variation and strong stabilizing selection along two major axes of genetic variation. PMID:25818173

An Architectonic Study of the Neocortex of the Short-Tailed Opossum (Monodelphis domestica)

PubMed Central

Wong, Peiyan; Kaas, Jon H.

2013-01-01

Short-tailed opossums (Monodelphis domestica) belong to the branch of marsupial mammals that diverged from eutherian mammals approximately 180 million years ago. They are small in size, lack a marsupial pouch, and may have retained more morphological characteristics of early marsupial neocortex than most other marsupials. In the present study, we used several different histochemical and immunochemical procedures to reveal the architectonic characteristics of cortical areas in short-tailed opossums. Subdivisions of cortex were identified in brain sections cut in the coronal, sagittal, horizontal or tangential planes and processed for a calcium-binding protein, parvalbumin (PV), neurofilament protein epitopes recognized by SMI-32, the vesicle glutamate transporter 2 (VGluT2), myelin, cytochrome oxidase (CO), and Nissl substance. These different procedures revealed similar boundaries among areas, suggesting that functionally relevant borders were detected. The results allowed a fuller description and more precise demarcation of previously identified sensory areas, and the delineation of additional subdivisions of cortex. Area 17 (V1) was especially prominent, with a densely populated layer 4, high myelination levels, and dark staining of PV and VGluT2 immunopositive terminations. These architectonic features were present, albeit less pronounced, in somatosensory and auditory cortex. The major findings support the conclusion that short-tailed opossums have fewer cortical areas and their neocortex is less distinctly laminated than most other mammals. PMID:19546531

Prescribing prophylaxis to patients who have been exposed to HIV.

PubMed

Bagley, Sue

2012-03-01

Emergency nurse practitioners should be prepared to prescribe post-exposure prophylaxis for sexual exposure (PEPSE) to people who may have been exposed to HIV, even where the number of such presentations is small. As this article makes clear, nurse prescribers require a sound knowledge of the drugs recommended in PEPSE protocols, and of their side effects, to relieve patients' anxiety and inform them about safe sexual practice. The article offers a case study and reflection to show that patients, particularly those who may have been exposed to HIV, who have been given the information they want are more likely to complete their courses of treatment.

Small Airway Dysfunction and Abnormal Exercise Responses

PubMed Central

Petsonk, Edward L.; Stansbury, Robert C.; Beeckman-Wagner, Lu-Ann; Long, Joshua L.; Wang, Mei Lin

2016-01-01

Rationale Coal mine dust exposure can cause symptoms and loss of lung function from multiple mechanisms, but the roles of each disease process are not fully understood. Objectives We investigated the implications of small airway dysfunction for exercise physiology among a group of workers exposed to coal mine dust. Methods Twenty coal miners performed spirometry, first breathing air and then helium-oxygen, single-breath diffusing capacity, and computerized chest tomography, and then completed cardiopulmonary exercise testing. Measurements and Main Results Six participants meeting criteria for small airway dysfunction were compared with 14 coal miners who did not. At submaximal workload, miners with small airway dysfunction used a higher proportion of their maximum voluntary ventilation and had higher ventilatory equivalents for both O2 and CO2. Regression modeling indicated that inefficient ventilation was significantly related to small airway dysfunction but not to FEV1 or diffusing capacity. At the end of exercise, miners with small airway dysfunction had 27% lower O2 consumption. Conclusions Small airway abnormalities may be associated with important inefficiency of exercise ventilation. In dust-exposed individuals with only mild abnormalities on resting lung function tests or chest radiographs, cardiopulmonary exercise testing may be important in defining causes of exercise intolerance. PMID:27073987

Posture does not matter! Paw usage and grasping paw preference in a small-bodied rooting quadrupedal mammal.

PubMed

Joly, Marine; Scheumann, Marina; Zimmermann, Elke

2012-01-01

Recent results in birds, marsupials, rodents and nonhuman primates suggest that phylogeny and ecological factors such as body size, diet and postural habit of a species influence limb usage and the direction and strength of limb laterality. To examine to which extent these findings can be generalised to small-bodied rooting quadrupedal mammals, we studied trees shrews (Tupaia belangeri). We established a behavioural test battery for examining paw usage comparable to small-bodied primates and tested 36 Tupaia belangeri. We studied paw usage in a natural foraging situation (simple food grasping task) and measured the influence of varying postural demands (triped, biped, cling, sit) on paw preferences by applying a forced-food grasping task similar to other small-bodied primates. Our findings suggest that rooting tree shrews prefer mouth over paw usage to catch food in a natural foraging situation. Moreover, we demonstrated that despite differences in postural demand, tree shrews show a strong and consistent individual paw preference for grasping across different tasks, but no paw preference at a population level. Tree shrews showed less paw usage than small-bodied quadrupedal and arboreal primates, but the same paw preference. Our results confirm that individual paw preferences remain constant irrespective of postural demand in some small-bodied quadrupedal non primate and primate mammals which do not require fine motoric control for manipulating food items. Our findings suggest that the lack of paw/hand preference for grasping food at a population level is a universal pattern among those species and that the influence of postural demand on manual lateralisation in quadrupeds may have evolved in large-bodied species specialised in fine manipulations of food items.

Potential contribution of exposed resin to ecosystem emissions of monoterpenes

NASA Astrophysics Data System (ADS)

Eller, Allyson S. D.; Harley, Peter; Monson, Russell K.

2013-10-01

Conifers, especially pines, produce and store under pressure monoterpene-laden resin in canals located throughout the plant. When the plants are damaged and resin canals punctured, the resin is exuded and the monoterpenes are released into the atmosphere, a process that has been shown to influence ecosystem-level monoterpene emissions. Less attention has been paid to the small amounts of resin that are exuded from branches, expanding needles, developing pollen cones, and terminal buds in the absence of any damage. The goal of this study was to provide the first estimate of the potential of this naturally-exposed resin to influence emissions of monoterpenes from ponderosa pine (Pinus ponderosa) ecosystems. When resin is first exuded as small spherical beads from undamaged tissues it emits monoterpenes to the atmosphere at a rate that is four orders of magnitude greater than needle tissue with an equivalent exposed surface area and the emissions from exuded beads decline exponentially as the resin dries. We made measurements of resin beads on the branches of ponderosa pine trees in the middle of the growing season and found, on average, 0.15 cm2 of exposed resin bead surface area and 1250 cm2 of total needle surface area per branch tip. If the resin emerged over the course of 10 days, resin emissions would make up 10% of the ecosystem emissions each day. Since we only accounted for exposed resin at a single point in time, this is probably an underestimate of how much total resin is exuded from undamaged pine tissues over the course of a growing season. Our observations, however, reveal the importance of this previously unrecognized source of monoterpenes emitted from pine forests and its potential to influence regional atmospheric chemistry dynamics.

The astrobiological mission EXPOSE-R on board of the International Space Station

NASA Astrophysics Data System (ADS)

Rabbow, Elke; Rettberg, Petra; Barczyk, Simon; Bohmeier, Maria; Parpart, Andre; Panitz, Corinna; Horneck, Gerda; Burfeindt, Jürgen; Molter, Ferdinand; Jaramillo, Esther; Pereira, Carlos; Weiß, Peter; Willnecker, Rainer; Demets, René; Dettmann, Jan

2015-01-01

EXPOSE-R flew as the second of the European Space Agency (ESA) EXPOSE multi-user facilities on the International Space Station. During the mission on the external URM-D platform of the Zvezda service module, samples of eight international astrobiology experiments selected by ESA and one Russian guest experiment were exposed to low Earth orbit space parameters from March 10th, 2009 to January 21st, 2011. EXPOSE-R accommodated a total of 1220 samples for exposure to selected space conditions and combinations, including space vacuum, temperature cycles through 273 K, cosmic radiation, solar electromagnetic radiation at >110, >170 or >200 nm at various fluences up to GJ m-2. Samples ranged from chemical compounds via unicellular organisms and multicellular mosquito larvae and seeds to passive radiation dosimeters. Additionally, one active radiation measurement instrument was accommodated on EXPOSE-R and commanded from ground in accordance with the facility itself. Data on ultraviolet radiation, cosmic radiation and temperature were measured every 10 s and downlinked by telemetry and data carrier every few months. The EXPOSE-R trays and samples returned to Earth on March 9th, 2011 with Shuttle flight, Space Transportation System (STS)-133/ULF 5, Discovery, after successful total mission duration of 27 months in space. The samples were analysed in the individual investigators laboratories. A parallel Mission Ground Reference experiment was performed on ground with a parallel set of hardware and samples under simulated space conditions following to the data transmitted from the flight mission.

Russian Extravehicular Activity (EVA) 21A EXPOSE-R

NASA Image and Video Library

2009-03-10

ISS018-E-039227 (10 March 2009) --- One of two Expedition 18 spacewalkers on March 10 provided this close-up image of the Expose-R experiment, reinstalled a short while earlier on the outside of the Russian segment of the International Space Station. The European experiment is equipped with three trays which contain a variety of biological samples.

Russian Extravehicular Activity (EVA) 21A EXPOSE-R

NASA Image and Video Library

2009-03-10

ISS018-E-039228 (10 March 2009) --- One of two Expedition 18 spacewalkers on March 10 provided this close-up image of the Expose-R experiment, reinstalled a short while earlier on the outside of the Russian segment of the International Space Station. The European experiment is equipped with three trays which contain a variety of biological samples.

Russian Extravehicular Activity (EVA) 21A EXPOSE-R

NASA Image and Video Library

2009-03-10

ISS018-E-039226 (10 March 2009) --- One of two Expedition 18 spacewalkers on March 10 provided this close-up image of the Expose-R experiment, reinstalled a short while earlier on the outside of the Russian segment of the International Space Station. The European experiment is equipped with three trays which contain a variety of biological samples.

Cool running: locomotor performance at low body temperature in mammals.

PubMed

Rojas, A Daniella; Körtner, Gerhard; Geiser, Fritz

2012-10-23

Mammalian torpor saves enormous amounts of energy, but a widely assumed cost of torpor is immobility and therefore vulnerability to predators. Contrary to this assumption, some small marsupial mammals in the wild move while torpid at low body temperatures to basking sites, thereby minimizing energy expenditure during arousal. Hence, we quantified how mammalian locomotor performance is affected by body temperature. The three small marsupial species tested, known to use torpor and basking in the wild, could move while torpid at body temperatures as low as 14.8-17.9°C. Speed was a sigmoid function of body temperature, but body temperature effects on running speed were greater than those in an ectothermic lizard used for comparison. We provide the first quantitative data of movement at low body temperature in mammals, which have survival implications for wild heterothermic mammals, as directional movement at low body temperature permits both basking and predator avoidance.

The Expose-R2 mission: astrobiology and astrochemistry in low Earth orbit

NASA Astrophysics Data System (ADS)

Demets, René

EXPOSE is an exposure platform developed by ESA which permits scientists to install test samples for 1 to 2 years at the outer surface of the ISS. In that way, the impact of the open space environment on biological and biochemical sample materials can be explored. This environment, featuring full-spectrum solar light, near-vacuum, cosmic radiation, wide temperature variations and near-weightlessness, is impossible to reproduce in its entirety in the lab. As such, EXPOSE offers astrochemists and astrobiologists a chance to acquire novel scientific data. Astrochemists are interested in Low Earth Orbit conditions due to the fact that photochemistry in space is quite different from photochemistry on Earth, where the high-energy UV compounds of the solar spectrum are filtered away by our atmosphere. As for the astro biologists, EXPOSE offers an attractive opportunity to expand earlier results obtained during short-duration LEO flights, which have shown that particular microbes and, amazingly, even some multi-cellular macroscopic organisms were able to cope with a two-week exposure to space. The open space environment, often described as harsh and hostile, can apparently be tolerated by some robust inhabitants of our Earth - unprotected, in the absence of a space suit! The first mission of EXPOSE, as an external payload on the European Columbus module, happened during 2008-2009 with the test samples provided by five separate research teams. Three additional teams were involved in the monitoring of space environment. The results were published collectively in 2012 in a special issue of the monthly journal Astrobiology. Several organisms survived, having spent 1.5 years in space. The second mission was called EXPOSE-R, the R referring to ‘Russian segment’, the location where the EXPOSE instrument was installed this time. The EXPOSE-R mission took place in 2009-2011, ten science teams were involved. The publication of the results, again as a collection, is currently in

Five years follow-up of a keratocyst odontogenic tumor treated by marsupialization and enucleation: A case report and literature review

PubMed Central

de Molon, Rafael Scaf; Verzola, Mario H.; Pires, Luana C.; Mascarenhas, Vinicius I.; da Silva, Rodrigo B.; Cirelli, Joni A.; Barbeiro, Roberto H.

2015-01-01

Odontogenic cysts are considered as nonneoplasic benign lesions. Among the cysts, keratocyst odontogenic tumor (KCOT) is an intra-osseous tumor characterized by parakeratinized stratified squamous epithelium and a potential for aggressive, infiltrative behavior, and for the possibility to develop carcinomas in the lesion wall. Thus, the aim of this study was to describe a clinical case of KCOT in a young patient and discuss the treatment alternatives to solve this case. A 15-year-old male was referred for treatment of a giant lesion in his left side of the mandible. After the biopsy, a diagnostic of KCOT was made, and the following procedures were planned for KCOT treatment. Marsupialization was performed for lesion decompression and consequent lesion size reduction. Afterward, enucleation for complete KCOT removal was performed followed by third mandibular molar extraction. After 5 years, no signs of recurrence were observed. The treatment proposed was efficient in removing the KCOT with minimal surgical morbidity and optimal healing process, and the first and second mandibular molars were preserved with pulp vitality. In conclusion, this treatment protocol was an effective and conservative approach for the management of the KCOT, enabling the reduction of the initial lesion, the preservation of anatomical structures and teeth, allowing quicker return to function. No signs of recurrence after 5 years were observed. PMID:25821360

Serologic evidence of canine parvovirus in domestic dogs, wild carnivores, and marsupials in the Argentinean Chaco.

PubMed

Orozco, María Marcela; Miccio, Luciano; Enriquez, Gustavo Fabián; Iribarren, Fabián Eduardo; Gürtler, Ricardo Esteban

2014-09-01

The transmission of pathogens between domestic dogs and generalist wildlife species may be modified by environmental degradation, biodiversity losses, host densities, and increased contact rates in remnant forest patches. A serologic survey of canine parvovirus (CPV) in rural domestic dogs and wild mammals was conducted in two neighboring rural areas (disturbed and protected) from Pampa del Indio, northeastern Argentina, between 2008 and 2011. A total of 174 domestic dogs and 26 wild mammals-4 crab-eating foxes (Cerdocyon thous), 3 crab-eating raccoons (Procyon cancrivorus), 17 white-eared opossums (Didelphis albiventris), and 2 gray four-eyed opossums (Philander opossum)-were examined for antibodies to CPV using a hemagglutination inhibition assay. Domestic dogs were numerous and their movements unrestricted. The main function of dogs differed significantly between areas, with more dogs used for herding or hunting around the protected area. The seroprevalence of antibodies to CPV in dogs from both areas was very high (93.9-94.6%) and increased steeply with age. Nearly all carnivores and marsupials showed high exposure to CPV. Although a higher exposure to CPV was expected in wild mammals from disturbed areas as a result of enhanced contact between dogs and wildlife, no significant differences were found between areas. To the authors' knowledge, this study is the first to document exposure to CPV of free-ranging Pr. cancrivorus, D. albiventris, and Ph. opossum, and include a detailed demographic study of the domestic dog populations living in the area. This study highlights that dogs and wildlife have potential opportunities for contact and shows that the edges of the protected area may be as suitable as other fragmented areas for the transmission of CPV. Rural domestic dogs may pose serious threats to the health and conservation of wild carnivores in both disturbed and protected areas, especially in the Gran Chaco, where habitat fragmentation is severely

High-risk occupations for women exposed to cadmium.

PubMed

Freeman, C S

1994-08-01

Occupational exposures to cadmium are associated with increased risk of lung cancer and renal disease. The Occupational Safety and Health Administration (OSHA) published two standards for cadmium on September 14, 1992 that reduced the permissible occupational exposure limit. In the cadmium industry, women were less likely to be exposed to high levels of cadmium and more likely to hold job titles containing the word "hand" than were men. Only small numbers of female workers were exposed to any level of cadmium. OSHA's risk assessment relied, in part, on morbidity and mortality data from male workers and in part on rodent (animal) data from both sexes. OSHA did not evaluate illness rates specific to female workers. Several factors may alter the risk of these illnesses and their sequelae among workers, including differences in smoking, route of exposures, ability to wear personal protective equipment, and lifestyle.

Adaptive responses and disruptive effects: how major wildfire influences kinship-based social interactions in a forest marsupial.

PubMed

Banks, Sam C; Blyton, Michaela D J; Blair, David; McBurney, Lachlan; Lindenmayer, David B

2012-02-01

Environmental disturbance is predicted to play a key role in the evolution of animal social behaviour. This is because disturbance affects key factors underlying social systems, such as demography, resource availability and genetic structure. However, because natural disturbances are unpredictable there is little information on their effects on social behaviour in wild populations. Here, we investigated how a major wildfire affected cooperation (sharing of hollow trees) by a hollow-dependent marsupial. We based two alternative social predictions on the impacts of fire on population density, genetic structure and resources. We predicted an adaptive social response from previous work showing that kin selection in den-sharing develops as competition for den resources increases. Thus, kin selection should occur in burnt areas because the fire caused loss of the majority of hollow-bearing trees, but no detectable mortality. Alternatively, fire may have a disruptive social effect, whereby postfire home range-shifts 'neutralize' fine-scale genetic structure, thereby removing opportunities for kin selection between neighbours. Both predictions occurred: the disruptive social effect in burnt habitat and the adaptive social response in adjacent unburnt habitat. The latter followed a massive demographic influx to unburnt 'refuge' habitat that increased competition for dens, leading to a density-related kin selection response. Our results show remarkable short-term plasticity of animal social behaviour and demonstrate how the social effects of disturbance extend into undisturbed habitat owing to landscape-scale demographic shifts. We predicted long-term changes in kinship-based cooperative behaviour resulting from the genetic and resource impacts of forecast changes to fire regimes in these forests. © 2011 Blackwell Publishing Ltd.

Fibrosis biomarkers in workers exposed to MWCNTs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fatkhutdinova, Liliya M., E-mail: liliya.fatkhutdi

Multi-walled carbon nanotubes (MWCNT) with their unique physico-chemical properties offer numerous technological advantages and are projected to drive the next generation of manufacturing growth. As MWCNT have already found utility in different industries including construction, engineering, energy production, space exploration and biomedicine, large quantities of MWCNT may reach the environment and inadvertently lead to human exposure. This necessitates the urgent assessment of their potential health effects in humans. The current study was carried out at NanotechCenter Ltd. Enterprise (Tambov, Russia) where large-scale manufacturing of MWCNT along with relatively high occupational exposure levels was reported. The goal of this small cross-sectionalmore » study was to evaluate potential biomarkers during occupational exposure to MWCNT. All air samples were collected at the workplaces from both specific areas and personal breathing zones using filter-based devices to quantitate elemental carbon and perform particle analysis by TEM. Biological fluids of nasal lavage, induced sputum and blood serum were obtained from MWCNT-exposed and non-exposed workers for assessment of inflammatory and fibrotic markers. It was found that exposure to MWCNTs caused significant increase in IL-1β, IL6, TNF-α, inflammatory cytokines and KL-6, a serological biomarker for interstitial lung disease in collected sputum samples. Moreover, the level of TGF-β1 was increased in serum obtained from young exposed workers. Overall, the results from this study revealed accumulation of inflammatory and fibrotic biomarkers in biofluids of workers manufacturing MWCNTs. Therefore, the biomarkers analyzed should be considered for the assessment of health effects of occupational exposure to MWCNT in cross-sectional epidemiological studies. - Highlights: • The effects of MWCNT exposure in humans remain unclear. • We found increased KL-6/TGF-β levels in the biofluids of MWCNT-exposed workers. �

Small Expanded Craters in the Northern Lowlands

NASA Image and Video Library

2016-08-24

This image shows many small craters over a larger degraded one in the northern lowlands. These small craters are smoother and shallower than their counterparts closer to the equator. Scientists believe this difference is a result of impact into a region with subsurface ice, which sublimates when exposed to the Martian atmosphere. This causes the crater to gradually expand and flatten after impact. http://photojournal.jpl.nasa.gov/catalog/PIA21021

Effects of habitat fragmentation on wild mammal infection by Trypanosoma cruzi.

PubMed

Vaz, V C; D'Andrea, P S; Jansen, A M

2007-11-01

Expansion of human activities frequently results in habitat fragmentation, a phenomenon that has been widely recognized in the last decades as one of the major threats to world's biodiversity. The transformation of a continuous forest into a fragmented area results in a hyper-dynamic landscape with unpredictable consequences to overall ecosystem health. The effect of the fragmentation process on Trypanosoma cruzi infection among small wild mammals was studied in an Atlantic Rain Forest landscape. Comparing continous forest to fragmented habitat, marsupials were less abundant than rodents in the continuous landscape. An overall decrease in small wild mammal richness was observed in the smaller fragments. An anti-T. cruzi seroprevalence of 18% (82/440) was deteced by immunofluorescence assay. Moreover, this seroprevalence was higher in the fragmented habitat than in the continuous forest. According to the collected data, 3 main factors seem to modulate infection by T. cruzi in small wild mammals: (i) habitat fragmentation; (ii) biodiversity loss; (iii) increase of marsupial abundance in mammal communities. Furthermore, an extremely mild controlled infection by T. cruzi was detected since no patent parasitaemia could be detected in fresh blood samples, and no parasites were isolated by haemoculture.

[Epidemiological study of cytopenia among benzene-exposed workers and its influential factors].

PubMed

Peng, Juan-juan; Liu, Mei-xia; Yang, Feng; Guo, Wei-wei; Zhuang, Ran; Jia, Xian-dong

2013-03-01

To evaluate the benzene exposure level and cytopenia among the benzene exposed workers in Shanghai, China and to analyze the influential factors for the health of benzene-exposed workers. A total of 3314 benzene-exposed workers, who were from 85 benzene-related enterprises selected by stratified random sampling based on enterprise sizes and industries, were included in the study. The time-weighted average (TWA) concentration of benzene in each workshop was measured by individual sampling and fixed point sampling, and the benzene exposure level in workshop was evaluated accordingly. The occupational health examination results and health status of benzene-exposed workers were collected. The median of TW A concentrations of benzene was 0.3 mg/m3. The TWA concentrations measured at 7 ( 1.4%) of the 504 sampling points were above the safety limit. Of the 7 points, 3 were from large enterprises, 2 from medium enterprises, and 2 from small enterprises; 3 were from shipbuilding industry, 1 from chemical industry, and 3 from light industry. Of the 3314 benzene-exposed workers, 451 ( 13.6%) had cytopenia, including 339 males ( 339/2548, 13.3%) and 112 females ( 112/766, 14.6% ). There were significant differences in the incidence rates of leukopenia and neutropenia among the benzene-exposed workers of different sexes and ages (P<0.05); there were significant differences in the incidence rate of cytopenia among the benzene-exposed workers of different ages and working years ( P<0.05 ); there were significant differences in the incidence of neutropenia among the benzene exposed workers of different working years ( P<0.05). Monitoring and intervention measures should be enhanced to protect the benzene-exposed workers in the large enterprises in shipbuilding industry and medium and private enterprises in chemical industry from occupational hazards.

Fracture behaviour of the 14Cr ODS steel exposed to helium and liquid lead

NASA Astrophysics Data System (ADS)

Hojna, Anna; Di Gabriele, Fosca; Hadraba, Hynek; Husak, Roman; Kubena, Ivo; Rozumova, Lucia; Bublikova, Petra; Kalivodova, Jana; Matejicek, Jiri

2017-07-01

This work describes the fracture behaviour of the 14Cr ODS steel produced by mechanical alloying process, after high temperature exposures. Small specimens were exposed to helium gas in a furnace at 720 °C for 500 h. Another set of specimens was exposed to flowing liquid lead in the COLONRI II loop at 650 °C for 1000 h. All specimens were tested for the impact and tensile behaviour. The impact test results are compared to other sets of specimens in the as received state and after isothermal annealing at 650 °C for 1000 h. The impact curves of the exposed materials showed positive shifts on the transition temperature. While the upper shelf value did not change in the Pb exposed ODS steel, it significantly increased in the He exposed one. The differences are discussed in terms of surface and subsurface microscopy observation. The embrittlement can be explained as the effect of a slight change in the grain boundary and size distribution combined with the depletion of sub-surface region from alloying elements forming oxide scale on the surface.

Quantifying short-term foraging movements in a marsupial pest to improve targeted lethal control and disease surveillance.

PubMed

Yockney, Ivor J; Latham, M Cecilia; Rouco, Carlos; Cross, Martin L; Nugent, Graham

2015-01-01

In New Zealand, the introduced marsupial brushtail possum (Trichosurus vulpecula) is a pest species subject to control measures, primarily to limit its ability to transmit bovine tuberculosis (TB) to livestock and for conservation protection. To better define parameters for targeted possum control and TB surveillance, we here applied a novel approach to analyzing GPS data obtained from 44 possums fitted with radio-tracking collars, producing estimates of the animals' short-term nocturnal foraging patterns based on 1-, 3- or 5-nights' contiguous data. Studies were conducted within two semi-arid montane regions of New Zealand's South Island High Country: these regions support low-density possum populations (<2 possums/ha) in which the animals' home ranges are on average larger than in high-density populations in forested habitat. Possum foraging range width (FRW) estimates increased with increasing monitoring periods, from 150-200 m based on a single night's movement data to 300-400 m based on 5 nights' data. The largest average FRW estimates were recorded in winter and spring, and the smallest in summer. The results suggest that traps or poison-bait stations (for lethal control) or monitoring devices (for TB surveillance), set for > 3 consecutive nights at 150 m interval spacings, would likely place >95% of the possums in this type of habitat at risk of encountering these devices, year-round. Modelling control efficacy against operational expenditure, based on these estimations, identified the relative cost-effectiveness of various strategies that could be applied to a typical aerial poisoning operation, to reduce the ongoing TB vectorial risk that possums pose in the High Country regions. These habitat-specific findings are likely to be more relevant than the conventional pest control and monitoring methodologies developed for possums in their more typical forested habitat.

Genome sequence of an Australian kangaroo, Macropus eugenii, provides insight into the evolution of mammalian reproduction and development

PubMed Central

2011-01-01

Background We present the genome sequence of the tammar wallaby, Macropus eugenii, which is a member of the kangaroo family and the first representative of the iconic hopping mammals that symbolize Australia to be sequenced. The tammar has many unusual biological characteristics, including the longest period of embryonic diapause of any mammal, extremely synchronized seasonal breeding and prolonged and sophisticated lactation within a well-defined pouch. Like other marsupials, it gives birth to highly altricial young, and has a small number of very large chromosomes, making it a valuable model for genomics, reproduction and development. Results The genome has been sequenced to 2 × coverage using Sanger sequencing, enhanced with additional next generation sequencing and the integration of extensive physical and linkage maps to build the genome assembly. We also sequenced the tammar transcriptome across many tissues and developmental time points. Our analyses of these data shed light on mammalian reproduction, development and genome evolution: there is innovation in reproductive and lactational genes, rapid evolution of germ cell genes, and incomplete, locus-specific X inactivation. We also observe novel retrotransposons and a highly rearranged major histocompatibility complex, with many class I genes located outside the complex. Novel microRNAs in the tammar HOX clusters uncover new potential mammalian HOX regulatory elements. Conclusions Analyses of these resources enhance our understanding of marsupial gene evolution, identify marsupial-specific conserved non-coding elements and critical genes across a range of biological systems, including reproduction, development and immunity, and provide new insight into marsupial and mammalian biology and genome evolution. PMID:21854559

Genome sequence of an Australian kangaroo, Macropus eugenii, provides insight into the evolution of mammalian reproduction and development.

PubMed

Renfree, Marilyn B; Papenfuss, Anthony T; Deakin, Janine E; Lindsay, James; Heider, Thomas; Belov, Katherine; Rens, Willem; Waters, Paul D; Pharo, Elizabeth A; Shaw, Geoff; Wong, Emily S W; Lefèvre, Christophe M; Nicholas, Kevin R; Kuroki, Yoko; Wakefield, Matthew J; Zenger, Kyall R; Wang, Chenwei; Ferguson-Smith, Malcolm; Nicholas, Frank W; Hickford, Danielle; Yu, Hongshi; Short, Kirsty R; Siddle, Hannah V; Frankenberg, Stephen R; Chew, Keng Yih; Menzies, Brandon R; Stringer, Jessica M; Suzuki, Shunsuke; Hore, Timothy A; Delbridge, Margaret L; Patel, Hardip R; Mohammadi, Amir; Schneider, Nanette Y; Hu, Yanqiu; O'Hara, William; Al Nadaf, Shafagh; Wu, Chen; Feng, Zhi-Ping; Cocks, Benjamin G; Wang, Jianghui; Flicek, Paul; Searle, Stephen M J; Fairley, Susan; Beal, Kathryn; Herrero, Javier; Carone, Dawn M; Suzuki, Yutaka; Sugano, Sumio; Toyoda, Atsushi; Sakaki, Yoshiyuki; Kondo, Shinji; Nishida, Yuichiro; Tatsumoto, Shoji; Mandiou, Ion; Hsu, Arthur; McColl, Kaighin A; Lansdell, Benjamin; Weinstock, George; Kuczek, Elizabeth; McGrath, Annette; Wilson, Peter; Men, Artem; Hazar-Rethinam, Mehlika; Hall, Allison; Davis, John; Wood, David; Williams, Sarah; Sundaravadanam, Yogi; Muzny, Donna M; Jhangiani, Shalini N; Lewis, Lora R; Morgan, Margaret B; Okwuonu, Geoffrey O; Ruiz, San Juana; Santibanez, Jireh; Nazareth, Lynne; Cree, Andrew; Fowler, Gerald; Kovar, Christie L; Dinh, Huyen H; Joshi, Vandita; Jing, Chyn; Lara, Fremiet; Thornton, Rebecca; Chen, Lei; Deng, Jixin; Liu, Yue; Shen, Joshua Y; Song, Xing-Zhi; Edson, Janette; Troon, Carmen; Thomas, Daniel; Stephens, Amber; Yapa, Lankesha; Levchenko, Tanya; Gibbs, Richard A; Cooper, Desmond W; Speed, Terence P; Fujiyama, Asao; Graves, Jennifer A M; O'Neill, Rachel J; Pask, Andrew J; Forrest, Susan M; Worley, Kim C

2011-08-29

We present the genome sequence of the tammar wallaby, Macropus eugenii, which is a member of the kangaroo family and the first representative of the iconic hopping mammals that symbolize Australia to be sequenced. The tammar has many unusual biological characteristics, including the longest period of embryonic diapause of any mammal, extremely synchronized seasonal breeding and prolonged and sophisticated lactation within a well-defined pouch. Like other marsupials, it gives birth to highly altricial young, and has a small number of very large chromosomes, making it a valuable model for genomics, reproduction and development. The genome has been sequenced to 2 × coverage using Sanger sequencing, enhanced with additional next generation sequencing and the integration of extensive physical and linkage maps to build the genome assembly. We also sequenced the tammar transcriptome across many tissues and developmental time points. Our analyses of these data shed light on mammalian reproduction, development and genome evolution: there is innovation in reproductive and lactational genes, rapid evolution of germ cell genes, and incomplete, locus-specific X inactivation. We also observe novel retrotransposons and a highly rearranged major histocompatibility complex, with many class I genes located outside the complex. Novel microRNAs in the tammar HOX clusters uncover new potential mammalian HOX regulatory elements. Analyses of these resources enhance our understanding of marsupial gene evolution, identify marsupial-specific conserved non-coding elements and critical genes across a range of biological systems, including reproduction, development and immunity, and provide new insight into marsupial and mammalian biology and genome evolution.

The growth of small corrosion fatigue cracks in alloy 2024

NASA Technical Reports Server (NTRS)

Piascik, Robert S.; Willard, Scott A.

1993-01-01

The corrosion fatigue crack growth characteristics of small surface and corner cracks in aluminum alloy 2024 is established. The damaging effect of salt water on the early stages of small crack growth is characterized by crack initiation at constituent particle pits, intergranular microcracking for a less than 100 micrometers, and transgranular small crack growth for a micrometer. In aqueous 1 percent NaCl and at a constant anodic potential of -700 mV(sub SCE), small cracks exhibit a factor of three increase in fatigue crack growth rates compared to laboratory air. Small cracks exhibit accelerated corrosion fatigue crack growth rates at low levels of delta-K (less than 1 MPa square root of m) below long crack delta-K (sub th). When exposed to Paris regime levels of crack tip stress intensity, small corrosion fatigue cracks exhibit growth rates similar to that observed for long cracks. Results suggest that crack closure effects influence the corrosion fatigue crack growth rates of small cracks (a less than or equal to 100 micrometers). This is evidenced by similar small and long crack growth behavior at various levels of R. Contrary to the corrosion fatigue characteristics of small cracks in high strength steels, no pronounced chemical crack length effect is observed for Al by 2024 exposed to salt water.

Dose reconstruction for individuals exposed to ionizing radiation using chromosome painting

NASA Technical Reports Server (NTRS)

Lucas, J. N.; Cox, A. B. (Principal Investigator)

1997-01-01

To be most useful, a biomarker for dose reconstruction should employ an end point that is highly quantitative, stable with time and easily measured. Reciprocal translocations have been shown to be a promising biomarker that is linked to both prior exposure and risk, and they can be measured easily and quantitatively using fluorescence in situ hybridization. In contrast to other biomarkers that are available, the frequency of reciprocal translocations in individuals exposed to whole-body radiation is stable with time after exposure, has rather small interindividual variability and can be measured accurately at low levels of exposure. Results from recent studies demonstrate that measurements of reciprocal translocation frequencies, facilitated by chromosome painting, can be used to reconstruct radiation dose for individuals exposed in the distant past.

Dose reconstruction for individuals exposed to ionizing radiation using chromosome painting.

PubMed

Lucas, J N

1997-11-01

To be most useful, a biomarker for dose reconstruction should employ an end point that is highly quantitative, stable with time and easily measured. Reciprocal translocations have been shown to be a promising biomarker that is linked to both prior exposure and risk, and they can be measured easily and quantitatively using fluorescence in situ hybridization. In contrast to other biomarkers that are available, the frequency of reciprocal translocations in individuals exposed to whole-body radiation is stable with time after exposure, has rather small interindividual variability and can be measured accurately at low levels of exposure. Results from recent studies demonstrate that measurements of reciprocal translocation frequencies, facilitated by chromosome painting, can be used to reconstruct radiation dose for individuals exposed in the distant past.

NEONATAL VISUAL INFORMATION PROCESSING IN COCAINE-EXPOSED AND NON-EXPOSED INFANTS

PubMed Central

Singer, Lynn T.; Arendt, Robert; Fagan, Joseph; Minnes, Sonia; Salvator, Ann; Bolek, Tina; Becker, Michael

2014-01-01

This study investigated early neonatal visual preferences in 267 poly drug exposed neonates (131 cocaine-exposed and 136 non-cocaine exposed) whose drug exposure was documented through interviews and urine and meconium drug screens. Infants were given four visual recognition memory tasks comparing looking time to familiarized stimuli of lattices and rectangular shapes to novel stimuli of a schematic face and curved hourglass and bull’s eye forms. Cocaine-exposed infants performed more poorly, after consideration of confounding factors, with a relationship of severity of cocaine exposure to lower novelty score found for both self-report and biologic measures of exposure, Findings support theories which link prenatal cocaine exposure to deficits in information processing entailing attentional and arousal organizational systems. Neonatal visual discrimination and attention tasks should be further explored as potentially sensitive behavioral indicators of teratologic effects. PMID:25717215

Work ability score of solvent-exposed workers.

PubMed

Furu, Heidi; Sainio, Markku; Hyvärinen, Hanna-Kaisa; Kaukiainen, Ari

2018-03-28

Occupational chronic solvent encephalopathy (CSE), characterized by neurocognitive dysfunction, often leads to early retirement. However, only the more severe cases are diagnosed with CSE, and little is known about the work ability of solvent-exposed workers in general. The aim was to study memory and concentration symptoms, work ability and the effect of both solvent-related and non-occupational factors on work ability, in an actively working solvent-exposed population. A questionnaire on exposure and health was sent to 3640 workers in four solvent-exposed fields, i.e. painters and floor-layers, boat builders, printers, and metal workers. The total number of responses was 1730. We determined the work ability score (WAS), a single question item of the Work Ability Index, and studied solvent exposure, demographic factors, Euroquest memory and concentration symptoms, chronic diseases, and employment status using univariate and multivariate analyses. The findings were compared to those of a corresponding national blue-collar reference population (n = 221), and a small cohort of workers with CSE (n = 18). The proportion of workers with memory and concentration symptoms was significantly associated with solvent exposure. The WAS of solvent-exposed workers was lower than that of the national blue-collar reference group, and the difference was significant in the oldest age group (those aged over 60). Solvent-exposed worker's WAS were higher than those of workers diagnosed with CSE. The WAS were lowest among painters and floor-layers, followed by metal workers and printers, and highest among boat builders. The strongest explanatory factors for poor work ability were the number of chronic diseases, age and employment status. Solvent exposure was a weak independent risk factor for reduced WAS, comparable to a level of high alcohol consumption. Even if memory and concentration symptoms were associated with higher solvent exposure, the effect of solvents on self

Language outcomes at 12 years for children exposed prenatally to cocaine.

PubMed

Lewis, Barbara A; Minnes, Sonia; Short, Elizabeth J; Min, Meeyoung O; Wu, Miaoping; Lang, Adelaide; Weishampel, Paul; Singer, Lynn T

2013-10-01

In this study, the authors aimed to examine the long-term effects of prenatal cocaine exposure (PCE) on the language development of 12-year-old children using a prospective design, controlling for confounding prenatal drug exposure and environmental factors. Children who were exposed to cocaine in utero (PCE; n = 183) and children who were not exposed to cocaine (i.e., no cocaine exposure [NCE]; n = 181) were followed prospectively from birth to 12 years of age and were compared on language subtests of the Test of Language Development-Intermediate, Third Edition ( Hammill & Newcomer, 1997b), and phonological processing as measured by the Comprehensive Test of Phonological Processing ( Wagner & Torgesen, 1999). The authors evaluated the relationship of PCE to language development through a multivariate analysis of covariance and regression analyses while controlling for confounders. Results show that PCE has small effects on specific aspects of language, including syntax and phonological processing. The caregiver variables of lower maternal vocabulary, more psychological symptoms, and a poorer home environment also had consistent effects on language and phonological processing scores. These findings suggest that PCE continues to have small, subtle effects on specific aspects of language at age 12 years. Phonological processing skills were significantly related to the reading outcomes of letter-word identification, reading fluency, and reading comprehension, indicating that PCE also has small but lasting effects on the language skills that are related to later literacy skills.

Language Outcomes at 12 Years for Children Exposed Prenatally to Cocaine

PubMed Central

Lewis, Barbara A.; Minnes, Sonia; Short, Elizabeth J.; Min, Meeyoung O.; Wu, Miaoping; Lang, Adelaide; Weishampel, Paul; Singer, Lynn T.

2014-01-01

Purpose In this study, the authors aimed to examine the long-term effects of prenatal cocaine exposure (PCE) on the language development of 12-year-old children using a prospective design, controlling for confounding prenatal drug exposure and environmental factors. Method Children who were exposed to cocaine in utero (PCE; n = 183) and children who were not exposed to cocaine (i.e., no cocaine exposure [NCE]; n = 181) were followed prospectively from birth to 12 years of age and were compared on language subtests of the Test of Language Development—Intermediate, Third Edition (Hammill & Newcomer, 1997b), and phonological processing as measured by the Comprehensive Test of Phonological Processing (Wagner & Torgesen, 1999). The authors evaluated the relationship of PCE to language development through a multivariate analysis of covariance and regression analyses while controlling for confounders. Results Results show that PCE has small effects on specific aspects of language, including syntax and phonological processing. The caregiver variables of lower maternal vocabulary, more psychological symptoms, and a poorer home environment also had consistent effects on language and phonological processing scores. Conclusions These findings suggest that PCE continues to have small, subtle effects on specific aspects of language at age 12 years. Phonological processing skills were significantly related to the reading outcomes of letter–word identification, reading fluency, and reading comprehension, indicating that PCE also has small but lasting effects on the language skills that are related to later literacy skills. PMID:24149136

Thermal biology, torpor use and activity patterns of a small diurnal marsupial from a tropical desert: sexual differences.

PubMed

Körtner, Gerhard; Rojas, A Daniella; Geiser, Fritz

2010-08-01

Many small desert dasyurids employ torpor almost daily during winter, because cold nights and low food availability impose high energetic costs. However, in Western Australia the arid zone extends into tropical, coastal regions, where winter temperature conditions are far less severe. We studied the thermal biology and activity patterns of free-ranging kaluta (approximately 27 g), a dasyurid restricted to these tropical spinifex deserts, during the Austral winter (June-July) and in addition quantified activity patterns in captivity. Unlike most dasyurids, wild and captive kalutas were almost exclusively diurnal and retreated into underground burrows during the night. Despite being active during the warmer part of the day, kalutas entered torpor daily. However, torpor patterns differed remarkably between males and females. While females spent most of the night torpid at body temperatures (T (b)) as low as 21 degrees C, close to soil temperature, males entered multiple short and shallow bouts (T (b) > 25 degrees C) during the night. Males also maintained higher T (b)s during the early morning when active, occupied larger home ranges and covered greater distances while foraging than females. Hence, males appear to expend more energy than the similar-sized females both while foraging and during the rest phase. We propose that physiological as well as behavioural preparations for the September mating season that culminate in a complete male die-off might already impose energetic costs on males during winter.

Measurement of DNA repair deficiency in workers exposed to benzene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hallberg, L.M.; Au, W.W.; El Zein, R.

1996-05-01

We hypothesize that chronic exposure to environmental toxicants can induce genetic damage causing DNA repair deficiencies and leading to the postulated mutator phenotype of carcinogenesis. To test our hypothesis, a host cell reactivation (HCR) assay was used in which pCMVcat plasmids were damaged with UV light (175, 350 J/m{sup 2} UV light), inactivating the chloramphenicol acetyltransferase reporter gene, and then transfected into lymphocytes. Transfected lymphocytes were therefore challenged to repair the damaged plasmids, reactivating the reporter gene. Xeroderma pigmentosum (XP) and Gaucher cell lines were used as positive and negative controls for the HCR assay. The Gaucher cell line repairedmore » normally but XP cell lines demonstrated lower repair activity. Additionally, the repair activity of the XP heterozygous cell line showed intermediate repair compared to the homozygous XP and Gaucher cells. We used HCR to measure the effects of benzene exposure on 12 exposed and 8 nonexposed workers from a local benzene plant. Plasmids 175 J/m{sup 2} and 350 J/m{sup 2} were repaired with a mean frequency of 66% and 58%, respectively, in control workers compared to 71% and 62% in exposed workers. Conversely, more of the exposed workers were grouped into the reduced repair category than controls. These differences in repair capacity between exposed and control workers were, however, not statistically significant. The lack of significant differences between the exposed and control groups may be due to extremely low exposure to benzene (<0.3 ppm), small population size, or a lack of benzene genotoxicity at these concentrations. These results are consistent with a parallel hprt gene mutation assay. 26 refs., 4 figs., 2 tabs.« less

Eryptosis in lead-exposed workers.

PubMed

Aguilar-Dorado, Itzel-Citlalli; Hernández, Gerardo; Quintanar-Escorza, Martha-Angelica; Maldonado-Vega, María; Rosas-Flores, Margarita; Calderón-Salinas, José-Víctor

2014-12-01

Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8μg/dl) and non-exposed workers (4.2μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca(2+)]i and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (<0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca(2+)], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. Copyright © 2014 Elsevier Inc. All rights reserved.

Eryptosis in lead-exposed workers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aguilar-Dorado, Itzel-Citlalli; Hernández, Gerardo; Quintanar-Escorza, Martha-Angelica

Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8 μg/dl) and non-exposed workers (4.2 μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterizedmore » by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca{sup 2+}]{sub i} and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (< 0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca{sup 2+}], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. - Graphical abstract: Fig. 1. (A) Blood lead concentration (PbB) and (B) phosphatidylserine externalization on erythrocyte membranes of non-lead exposed (□) and lead exposed workers (■). Values are mean ± SD. *Significantly different (P < 0.001). - Highlights: • Erythrocytes of lead exposed

Regional Extinctions and Quaternary Shifts in the Geographic Range of Lestodelphys halli, the Southernmost Living Marsupial: Clues for Its Conservation

PubMed Central

Formoso, Anahí E.; Martin, Gabriel M.; Teta, Pablo; Carbajo, Aníbal E.; Sauthier, Daniel E. Udrizar; Pardiñas, Ulyses F. J.

2015-01-01

The Patagonian opossum (Lestodelphys halli), the southernmost living marsupial, inhabits dry and open environments, mainly in the Patagonian steppe (between ~32°S and ~49°S). Its rich fossil record shows its occurrence further north in Central Argentina during the Quaternary. The paleoenvironmental meaning of the past distribution of L. halli has been mostly addressed in a subjective framework without an explicit connection with the climatic “space” currently occupied by this animal. Here, we assessed the potential distribution of this species and the changes occurred in its geographic range during late Pleistocene-Holocene times and linked the results obtained with conservation issues. To this end, we generated three potential distribution models with fossil records and three with current ones, using MaxEnt software. These models showed a decrease in the suitable habitat conditions for the species, highlighting a range shift from Central-Eastern to South-Western Argentina. Our results support that the presence of L. halli in the Pampean region during the Pleistocene-Holocene can be related to precipitation and temperature variables and that its current presence in Patagonia is more related to temperature and dominant soils. The models obtained suggest that the species has been experiencing a reduction in its geographic range since the middle Holocene, a process that is in accordance with a general increase in moisture and temperature in Central Argentina. Considering the findings of our work and the future scenario of global warming projected for Patagonia, we might expect a harsh impact on the distribution range of this opossum in the near future. PMID:26203650

Regional Extinctions and Quaternary Shifts in the Geographic Range of Lestodelphys halli, the Southernmost Living Marsupial: Clues for Its Conservation.

PubMed

Formoso, Anahí E; Martin, Gabriel M; Teta, Pablo; Carbajo, Aníbal E; Sauthier, Daniel E Udrizar; Pardiñas, Ulyses F J

2015-01-01

The Patagonian opossum (Lestodelphys halli), the southernmost living marsupial, inhabits dry and open environments, mainly in the Patagonian steppe (between ~32 °S and ~49 °S). Its rich fossil record shows its occurrence further north in Central Argentina during the Quaternary. The paleoenvironmental meaning of the past distribution of L. halli has been mostly addressed in a subjective framework without an explicit connection with the climatic "space" currently occupied by this animal. Here, we assessed the potential distribution of this species and the changes occurred in its geographic range during late Pleistocene-Holocene times and linked the results obtained with conservation issues. To this end, we generated three potential distribution models with fossil records and three with current ones, using MaxEnt software. These models showed a decrease in the suitable habitat conditions for the species, highlighting a range shift from Central-Eastern to South-Western Argentina. Our results support that the presence of L. halli in the Pampean region during the Pleistocene-Holocene can be related to precipitation and temperature variables and that its current presence in Patagonia is more related to temperature and dominant soils. The models obtained suggest that the species has been experiencing a reduction in its geographic range since the middle Holocene, a process that is in accordance with a general increase in moisture and temperature in Central Argentina. Considering the findings of our work and the future scenario of global warming projected for Patagonia, we might expect a harsh impact on the distribution range of this opossum in the near future.

Pulmonary responses of healthy young adults exposed to 0.06 and 0.08 ppm ozone

EPA Science Inventory

Background. Previous studies have shown small but significant decreases in spirometric lung function in healthy young adults exposed to 0.08 ppm ozone. It is unclear, however, if such effects may are seen at concentrations below 0.08 ppm. Methods. A group of 30 healthy young adul...

Two pests overlap: Drosophila suzukii (Diptera: Drosophilidae) use of fruit exposed to Halyomorpha halys (Hemiptera: Pentatomidae)

USDA-ARS?s Scientific Manuscript database

Spotted wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), and brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) are global economic pests. Both pests may co-occur on small fruits, and we investigated whether fruit recently exposed to H. halys woul...

Radiographic abnormalities among construction workers exposed to quartz containing dust

PubMed Central

Tjoe, N; Burdorf, A; Parker, J; Attfield, M; van Duivenbooden, C; Heederik, D

2003-01-01

Background: Construction workers are exposed to quartz containing respirable dust, at levels that may cause fibrosis in the lungs. Studies so far have not established a dose-response relation for radiographic abnormalities for this occupational group. Aims: To measure the extent of radiographic abnormalities among construction workers primarily exposed to quartz containing respirable dust. Methods: A cross sectional study on radiographic abnormalities indicative of pneumoconiosis was conducted among 1339 construction workers mainly involved in grinding, (jack)-hammering, drilling, cutting, sawing, and polishing. Radiological abnormalities were determined by median results of the 1980 International Labour Organisation system of three certified "B" readers. Questionnaires were used for assessment of occupational history, presence of respiratory diseases, and symptoms and smoking habits. Results: An abnormality of ILO profusion category 1/0 and greater was observed on 10.2% of the chest radiographs, and profusion category of 1/1 or greater on 2.9% of the radiographs. The average duration of exposure of this group was 19 years and the average age was 42. The predominant type of small opacities (irregularly shaped) is presumably indicative of mixed dust pneumoconiosis. The prevalence of early signs of nodular silicosis (small rounded opacities of category 1/0 or greater) was low (0.8%). Conclusions: The study suggests an elevated risk of radiographic abnormalities among these workers with expected high exposure. An association between radiographic abnormalities and cumulative exposure to quartz containing dust from construction sites was observed, after correction for potentially confounding variables. PMID:12771392

The effects of poly-unsaturated fatty acids on the physiology of hibernation in a South American marsupial, Dromiciops gliroides.

PubMed

Contreras, Carolina; Franco, Marcela; Place, Ned J; Nespolo, Roberto F

2014-11-01

Many mammals hibernate, which is a profound lethargic state of several weeks or months during winter, that represents a transitory episode of hetherothermy. As with other cases of dormancy, the main benefit of hibernation seems to be energy saving. However, the depth and duration of torpor can be experimentally modified by the composition of food, especially by fattyacid composition. In eutherians, diets rich in unsaturated fatty acids (i.e., fatty acids with at least one double bond) lengthen torpor, reduce metabolism and permit hibernation at lower temperatures. Here we studied whether diets varying in fatty acid composition have an effect on the physiology of hibernation in a South American marsupial, Dromiciops gliroides. We designed a factorial experiment where thermal acclimation (two levels: natural versus constant temperature) was combined with diet acclimation: saturated (i.e., diets with high concentration of saturated fatty acids) versus unsaturated (i.e., diets with high concentration of unsaturated fatty acids). We measured energy metabolism in active and torpid individuals, as well as torpor duration, and a suite of 12 blood biochemical parameters. After a cafeteria test, we found that D. gliroides did not show any preference for a given diet. Also, we did not find effects of diet on body temperature during torpor, or its duration. However, saturated diets, combined with high temperatures provoked a disproportionate increase in fat utilization, leading to body mass reduction. Those animals were more active, and metabolized more fats than those fed with a high proportion of unsaturated fatty acids (="unsaturated diets"). These results contrast with previous studies, which showed a significant effect of fatty acid composition of diets on food preferences and torpor patterns in mammals. Copyright © 2014 Elsevier Inc. All rights reserved.

Exposed Ice in the Northern Mid-Latitudes of Mars

NASA Technical Reports Server (NTRS)

Allen, Carlton C.

2007-01-01

Ice-Rich Layer: Polygonal features with dimensions of approximately 100 meters, bounded by cracks, are commonly observed on the martian northern plains. These features are generally attributed to thermal cracking of ice-rich sediments, in direct analogy to polygons in terrestrial polar regions. We mapped polygons in the northern mid-latitudes (30 to 65 N) using MOC and HiRISE images. Polygons are scattered across the northern plains, with a particular concentration in western Utopia Planitia. This region largely overlaps the Late Amazonian Astapus Colles unit, characterized by polygonal terrain and nested pits consistent with periglacial and thermokarst origins. Bright and Dark Polygonal Cracks: An examination of all MOC images (1997 through 2003) covering the study area demonstrated that, at latitudes of 55 to 65 N, most of the imaged polygons show bright bounding cracks. We interpret these bright cracks as exposed ice. Between 40 and 55 N, most of the imaged polygons show dark bounding cracks. These are interpreted as polygons from which the exposed ice has been removed by sublimation. The long-term stability limit for exposed ice, even in deep cracks, apparently lies near 55 N. Bright and Dark Spots: Many HiRISE and MOC frames showing polygons in the northern plains also show small numbers of bright and dark spots, particularly in western Utopia Planitia. Many of the spots are closely associated with collapse features suggestive of thermokarst. The spots range from tens to approximately 100 meters in diameter. The bright spots are interpreted as exposed ice, due to their prevalence on terrain mapped as ice rich. The dark spots are interpreted as former bright spots, which have darkened as the exposed ice is lost by sublimation. The bright spots may be the martian equivalents of pingos, ice-cored mounds found in periglacial regions on Earth. Terrestrial pingos from which the ice core has melted often collapse to form depressions similar to the martian dark spots

Chemical characterization of milk oligosaccharides of the tiger quoll (Dasyurus maculatus), a marsupial.

PubMed

Urashima, Tadasu; Yamamoto, Tomoko; Hirayama, Kentaro; Fukuda, Kenji; Nakamura, Tadashi; Saito, Tadao; Newgrain, Keith; Merchant, Jim; Green, Brian; Messer, Michael

2016-10-01

Milk oligosaccharides were separated from the carbohydrate fraction of milk of the tiger quoll a species of marsupial that is closely related to the eastern quoll, Dasyurus viverrinus. They were characterized by (1)H - nuclear magnetic resonance spectroscopy and matrix - assisted laser desorption/ionization time-of-flight mass spectrometry. The following oligosaccharides were identified; Gal(β1-3)Gal(β1-4)Glc, Gal(β1-3)Gal(β1-3)Gal(β1-4)Glc, Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc, Gal(β1-3)Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc, Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)Gal(β1-4)Glc, Gal(β1-3)[Gal(β1-3)Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc, Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc, Neu5Ac(α2-3) Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc, Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc with an α(2-3)Neu5Ac linked to β(1-4)Gal residue of either branch of Gal(β1-4)GlcNAc(β1-6) units, and Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc with a β(1-3) linked Gal and an α(2-3) linked Neu5Ac. In addition, larger oligosaccharides were characterized as follows; Gal(β1-3){Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)GlcNAc(β1-6)}Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc and Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-3){Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)GlcNAc(β1-6)}Gal(β1-4)Glc and their α(2-3) linked Neu5Ac derivatives.

Stimulus fear relevance and the speed, magnitude, and robustness of vicariously learned fear.

PubMed

Dunne, Güler; Reynolds, Gemma; Askew, Chris

2017-08-01

Superior learning for fear-relevant stimuli is typically indicated in the laboratory by faster acquisition of fear responses, greater learned fear, and enhanced resistance to extinction. Three experiments investigated the speed, magnitude, and robustness of UK children's (6-10 years; N = 290; 122 boys, 168 girls) vicariously learned fear responses for three types of stimuli. In two experiments, children were presented with pictures of novel animals (Australian marsupials) and flowers (fear-irrelevant stimuli) alone (control) or together with faces expressing fear or happiness. To determine learning speed the number of stimulus-face pairings seen by children was varied (1, 10, or 30 trials). Robustness of learning was examined via repeated extinction procedures over 3 weeks. A third experiment compared the magnitude and robustness of vicarious fear learning for snakes and marsupials. Significant increases in fear responses were found for snakes, marsupials and flowers. There was no indication that vicarious learning for marsupials was faster than for flowers. Moreover, vicariously learned fear was neither greater nor more robust for snakes compared to marsupials, or for marsupials compared to flowers. These findings suggest that for this age group stimulus fear relevance may have little influence on vicarious fear learning. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relating Demographic Characteristics of a Small Mammal to Remotely Sensed Forest-Stand Condition

PubMed Central

Lada, Hania; Thomson, James R.; Cunningham, Shaun C.; Mac Nally, Ralph

2014-01-01

Many ecological systems around the world are changing rapidly in response to direct (land-use change) and indirect (climate change) human actions. We need tools to assess dynamically, and over appropriate management scales, condition of ecosystems and their responses to potential mitigation of pressures. Using a validated model, we determined whether stand condition of floodplain forests is related to densities of a small mammal (a carnivorous marsupial, Antechinus flavipes) in 60 000 ha of extant river red gum (Eucalyptus camaldulensis) forests in south-eastern Australia in 2004, 2005 and 2011. Stand condition was assessed remotely using models built from ground assessments of stand condition and satellite-derived reflectance. Other covariates, such as volumes of fallen timber, distances to floods, rainfall and life stages were included in the model. Trapping of animals was conducted at 272 plots (0.25 ha) across the region. Densities of second-year females (i.e. females that had survived to a second breeding year) and of second-year females with suckled teats (i.e. inferred to have been successful mothers) were higher in stands with the highest condition. There was no evidence of a relationship with stand condition for males or all females. These outcomes show that remotely-sensed estimates of stand condition (here floodplain forests) are relatable to some demographic characteristics of a small mammal species, and may provide useful information about the capacity of ecosystems to support animal populations. Over-regulation of large, lowland rivers has led to declines in many facets of floodplain function. If management of water resources continues as it has in recent decades, then our results suggest that there will be further deterioration in stand condition and a decreased capacity for female yellow-footed antechinuses to breed multiple times. PMID:24621967

A transcriptome resource for the koala (Phascolarctos cinereus): insights into koala retrovirus transcription and sequence diversity.

PubMed

Hobbs, Matthew; Pavasovic, Ana; King, Andrew G; Prentis, Peter J; Eldridge, Mark D B; Chen, Zhiliang; Colgan, Donald J; Polkinghorne, Adam; Wilkins, Marc R; Flanagan, Cheyne; Gillett, Amber; Hanger, Jon; Johnson, Rebecca N; Timms, Peter

2014-09-11

The koala, Phascolarctos cinereus, is a biologically unique and evolutionarily distinct Australian arboreal marsupial. The goal of this study was to sequence the transcriptome from several tissues of two geographically separate koalas, and to create the first comprehensive catalog of annotated transcripts for this species, enabling detailed analysis of the unique attributes of this threatened native marsupial, including infection by the koala retrovirus. RNA-Seq data was generated from a range of tissues from one male and one female koala and assembled de novo into transcripts using Velvet-Oases. Transcript abundance in each tissue was estimated. Transcripts were searched for likely protein-coding regions and a non-redundant set of 117,563 putative protein sequences was produced. In similarity searches there were 84,907 (72%) sequences that aligned to at least one sequence in the NCBI nr protein database. The best alignments were to sequences from other marsupials. After applying a reciprocal best hit requirement of koala sequences to those from tammar wallaby, Tasmanian devil and the gray short-tailed opossum, we estimate that our transcriptome dataset represents approximately 15,000 koala genes. The marsupial alignment information was used to look for potential gene duplications and we report evidence for copy number expansion of the alpha amylase gene, and of an aldehyde reductase gene.Koala retrovirus (KoRV) transcripts were detected in the transcriptomes. These were analysed in detail and the structure of the spliced envelope gene transcript was determined. There was appreciable sequence diversity within KoRV, with 233 sites in the KoRV genome showing small insertions/deletions or single nucleotide polymorphisms. Both koalas had sequences from the KoRV-A subtype, but the male koala transcriptome has, in addition, sequences more closely related to the KoRV-B subtype. This is the first report of a KoRV-B-like sequence in a wild population. This transcriptomic

EXPOSE-R2: The Astrobiological ESA Mission on Board of the International Space Station.

PubMed

Rabbow, Elke; Rettberg, Petra; Parpart, Andre; Panitz, Corinna; Schulte, Wolfgang; Molter, Ferdinand; Jaramillo, Esther; Demets, René; Weiß, Peter; Willnecker, Rainer

2017-01-01

On July 23, 2014, the Progress cargo spacecraft 56P was launched from Baikonur to the International Space Station (ISS), carrying EXPOSE-R2, the third ESA (European Space Agency) EXPOSE facility, the second EXPOSE on the outside platform of the Russian Zvezda module, with four international astrobiological experiments into space. More than 600 biological samples of archaea, bacteria (as biofilms and in planktonic form), lichens, fungi, plant seeds, triops eggs, mosses and 150 samples of organic compounds were exposed to the harsh space environment and to parameters similar to those on the Mars surface. Radiation dosimeters distributed over the whole facility complemented the scientific payload. Three extravehicular activities later the chemical samples were returned to Earth on March 2, 2016, with Soyuz 44S, having spent 588 days in space. The biological samples arrived back later, on June 18, 2016, with 45S, after a total duration in space of 531 days. The exposure of the samples to Low Earth Orbit vacuum lasted for 531 days and was divided in two parts: protected against solar irradiation during the first 62 days, followed by exposure to solar radiation during the subsequent 469 days. In parallel to the space mission, a Mission Ground Reference (MGR) experiment with a flight identical Hardware and a complete flight identical set of samples was performed at the premises of DLR (German Aerospace Center) in Cologne by MUSC (Microgravity User Support Center), according to the mission data either downloaded from the ISS (temperature data, facility status, inner pressure status) or provided by RedShift Design and Engineering BVBA, Belgium (calculated ultra violet radiation fluence data). In this paper, the EXPOSE-R2 facility, the experimental samples, mission parameters, environmental parameters, and the overall mission and MGR sequences are described, building the background for the research papers of the individual experiments, their analysis and results.

EXPOSE-R2: The Astrobiological ESA Mission on Board of the International Space Station

PubMed Central

Rabbow, Elke; Rettberg, Petra; Parpart, Andre; Panitz, Corinna; Schulte, Wolfgang; Molter, Ferdinand; Jaramillo, Esther; Demets, René; Weiß, Peter; Willnecker, Rainer

2017-01-01

On July 23, 2014, the Progress cargo spacecraft 56P was launched from Baikonur to the International Space Station (ISS), carrying EXPOSE-R2, the third ESA (European Space Agency) EXPOSE facility, the second EXPOSE on the outside platform of the Russian Zvezda module, with four international astrobiological experiments into space. More than 600 biological samples of archaea, bacteria (as biofilms and in planktonic form), lichens, fungi, plant seeds, triops eggs, mosses and 150 samples of organic compounds were exposed to the harsh space environment and to parameters similar to those on the Mars surface. Radiation dosimeters distributed over the whole facility complemented the scientific payload. Three extravehicular activities later the chemical samples were returned to Earth on March 2, 2016, with Soyuz 44S, having spent 588 days in space. The biological samples arrived back later, on June 18, 2016, with 45S, after a total duration in space of 531 days. The exposure of the samples to Low Earth Orbit vacuum lasted for 531 days and was divided in two parts: protected against solar irradiation during the first 62 days, followed by exposure to solar radiation during the subsequent 469 days. In parallel to the space mission, a Mission Ground Reference (MGR) experiment with a flight identical Hardware and a complete flight identical set of samples was performed at the premises of DLR (German Aerospace Center) in Cologne by MUSC (Microgravity User Support Center), according to the mission data either downloaded from the ISS (temperature data, facility status, inner pressure status) or provided by RedShift Design and Engineering BVBA, Belgium (calculated ultra violet radiation fluence data). In this paper, the EXPOSE-R2 facility, the experimental samples, mission parameters, environmental parameters, and the overall mission and MGR sequences are described, building the background for the research papers of the individual experiments, their analysis and results. PMID

Marine exposure of preservative-treated small wood panels

Treesearch

B. R. Johnson; D. I. Gutzmer

1984-01-01

Small wood panels treated with many different chemicals have been exposed to limnorian and teredine marine borers in the sea at Key West, Florida. These preservatives and treatments include creosotes with and without modification, waterborne salts, salt-creosote dual treatments, chemical modifications of wood, and modified polymers. In spite of the accelerated nature...

The Skull of Epidolops ameghinoi from the Early Eocene Itaboraí Fauna, Southeastern Brazil, and the Affinities of the Extinct Marsupialiform Order Polydolopimorphia.

PubMed

Beck, Robin M D

2017-01-01

The skull of the polydolopimorphian marsupialiform Epidolops ameghinoi is described in detail for the first time, based on a single well-preserved cranium and associated left and right dentaries plus additional craniodental fragments, all from the early Eocene (53-50 million year old) Itaboraí fauna in southeastern Brazil. Notable craniodental features of E. ameghinoi include absence of a masseteric process, very small maxillopalatine fenestrae, a prominent pterygoid fossa enclosed laterally by a prominent ectopterygoid crest, an absent or tiny transverse canal foramen, a simple, planar glenoid fossa, and a postglenoid foramen that is immediately posterior to the postglenoid process. Most strikingly, the floor of the hypotympanic sinus was apparently unossified, a feature found in several stem marsupials but absent in all known crown marsupials. "Type II" marsupialiform petrosals previously described from Itaboraí plausibly belong to E. ameghinoi ; in published phylogenetic analyses, these petrosals fell outside (crown-clade) Marsupialia. "IMG VII" tarsals previously referred to E. ameghinoi do not share obvious synapomorphies with any crown marsupial clade, nor do they resemble those of the only other putative polydolopimorphians represented by tarsal remains, namely the argyrolagids. Most studies have placed Polydolopimorphia within Marsupialia, related to either Paucituberculata, or to Microbiotheria and Diprotodontia. However, diprotodonty almost certainly evolved independently in polydolopimorphians, paucituberculatans and diprotodontians, and Epidolops does not share obvious synapomorphies with any marsupial order. Epidolops is dentally specialized, but several morphological features appear to be more plesiomorphic than any crown marsupial. It seems likely Epidolops that falls outside Marsupialia, as do morphologically similar forms such as Bonapartherium and polydolopids. Argyrolagids differ markedly in their known morphology from Epidolops but share some

Postnatal weight loss in substitute methadone-exposed infants: implications for the management of breast feeding.

PubMed

Dryden, Carol; Young, David; Campbell, Nicole; Mactier, Helen

2012-05-01

It is widely accepted that maternal drug-exposed infants demonstrate excessive early weight loss, but this has not previously been quantified. Among 354 term, substitute methadone-exposed infants, median maximal weight losses were 10.2% and 8.5% for breast- and formula-fed infants, respectively (p=0.003). Weight loss was less in small for gestational age compared to appropriately grown infants (p<0.001). There was no association between maximal weight loss and plasma sodium concentration (p=0.807). Relative to non-drug exposed infants, weight loss was more marked in formula-fed infants, 48% of whom demonstrated weight loss in excess of the 95th centile (compared to 23% of exclusively breastfed infants; p<0.001). Median weight loss nadir was on day 5, excepting those infants exclusively breastfed (day 4). These data suggest that excessive neonatal weight loss among breastfed infants of drug-misusing mothers does not necessarily reflect poorly established lactation and may help to guide management of breast feeding in this population.

[Oxidative Stress Level of Vanadium-exposed Workers].

PubMed

Wei, Teng-da; Li, Shun-pin; Liu, Yun-xing; Tan, Chun-ping; Li, Juan; Zhang, Zu-hui; Lan, Ya-jia; Zhang, Qin

2015-11-01

To determine the oxidative stress level in peripheral blood of vanadium-exposed workers, as an indication of population health effect of vanadium on human neurobehavioral system. 86 vanadium-exposed workers and 65 non-exposed workers were recruited by cluster sampling. A questionnaire was administered to collect demographic and occupational exposure information. Serum activity of superoxide dismutase (SOD), inducible nitric oxide synthase (iNOS) and malonaldehyde (MDA) contents were detected by kit assay. The differences in oxidative stress level between vanadium-exposed and non-exposed workers were compared. Vanadium-exposed workers had higher levels of MDA contents than the controls. The total superoxide dismutase(T-SOD) activity in vanadium-exposed workers was significantly lower than that in the controls, which was associated with lowered levels of manganese superoxide dismutase (Mn-SOD) activity. No changes in serum levels of cupro-zinc superoxide dismutase (CuZn-SOD) was found in vanadium-exposed workers. No difference in iNOS activity was found between vanadium-exposed workers and controls. Vanadium exposure increases free radical production in serum and reduces antioxidant capacity. But the relationship between vanadium exposure and iNOS damage remains uncertain.

[Drug Exposed Infants and Their Families.

ERIC Educational Resources Information Center

Fenichel, Emily, Ed.

1992-01-01

This bulletin issue addresses the theme of drug-exposed infants and the services required by these infants and their families. "Cocaine-Exposed Infants: Myths and Misunderstandings" (Barbara J. Myers and others) comments on the negative accounts of drug-exposed babies presented by mass media and reviews the mix of positive and negative…

Nutritional Status among the Children of Age Group 5-14 Years in Selected Arsenic Exposed and Non-Exposed Areas of Bangladesh.

PubMed

Rezaul Karim, Mohammad; Ahmad, Sk Akhtar

2014-12-01

To assess and compare the nutritional status of children aged 5-14 years in arsenic exposed and non- exposed areas. It was a cross sectional study conducted on 600 children of age 5-14 years from arsenic exposed and non-exposed areas in Bangladesh. Designed questionnaire and check list were used for collection of data. To estimate BMI necessary anthropometric measurements of the studied children were done. Dietary intakes of the study children were assessed using 24-hours recall method. The difference of socio-economic conditions between the children of exposed area and non-exposed area was not significant. On an average the body mass index was found to be significantly (p < 0.01) lower among the children of arsenic exposed area (49%) in comparison to that of children in non-exposed area (38%). Stunting (p < 0.01), wasting (p < 0.05) and underweight (p < 0.05) were significantly higher in exposed group in comparison to non-exposed group. No significant difference of nutrition intake was found between exposed and non-exposed children as well as thin and normal children. In this study children exposed to arsenic contaminated water were found to be suffered from lower nutritional status.

Fire resistance of exposed wood members

Treesearch

Robert H. White

2004-01-01

Fire resistance data on exposed wood beams and columns are plentiful, but few studies have been done on exposed wood members in tension and in decks. To provide data to verify the application of a new calculation procedure, a limited series of fire resistance tests were conducted on wood members loaded in tension and on exposed wood decks.

Electron-stimulated desorption study of hydrogen-exposed aluminum films

NASA Technical Reports Server (NTRS)

Park, CH.; Bujor, M.; Poppa, H.

1984-01-01

H2 adsorption of evaporated clean and H2-exposed aluminum films is investigated by using the electron-stimulated desorption (ESD) method. A strong H(+)ESD signal is observed on a freshly evaporated aluminum surface which is clean according to previously proposed cleanlines criteria. An increased H(+) yield on H2 exposure is also observed. However, the increasing rate of H(+) emission could be directly correlated with small increases in H2O partial pressure during H2 exposure. It is proposed that the oxidation of aluminum by water vapor and subsequent adsorption of H2 or water is the primary process of the enhanced high H(+) yield during H2 exposure.

Rhodamine-Injected Eggs to Photographically Identify Small Nest-Predators

Treesearch

Thomas J. Maier; Richard M. DeGraaf

2000-01-01

Photographs that clearly disclose avian-nest predators are difficult to obtain, particularly when predators are small and exhibit subtle depredatory behavior. We exposed House Sparrow (Passer domesticus) eggs injected with Rhodamine B dye in camera-monitored ground nests for 12-d periods at 76 sites within mixed-hardwood forest stands in central...

Smoking imputation and lung cancer in railroad workers exposed to diesel exhaust.

PubMed

Garshick, Eric; Laden, Francine; Hart, Jaime E; Smith, Thomas J; Rosner, Bernard

2006-09-01

An association between diesel exhaust exposure and lung cancer mortality in a large retrospective cohort study of US railroad workers has previously been reported. However, specific information regarding cigarette smoking was unavailable. Birth cohort, age, job, and cause of death specific smoking histories from a companion case-control study were used to impute smoking behavior for 39,388 railroad workers who died 1959-1996. Mortality analyses incorporated the effect of smoking on lung cancer risk. The smoking adjusted relative risk of lung cancer in railroad workers exposed to diesel exhaust compared to unexposed workers was 1.22 (95% CI = 1.12-1.32), and unadjusted for smoking the relative risk was 1.35 (95% CI = 1.24-1.46). These analyses illustrate the use of imputation in record-based occupational health studies to assess potential confounding due to smoking. In this cohort, small differences in smoking behavior between diesel exposed and unexposed workers did not explain the elevated lung cancer risk.

The PUR Experiment on the EXPOSE-R facility: biological dosimetry of solar extraterrestrial UV radiation

NASA Astrophysics Data System (ADS)

Bérces, A.; Egyeki, M.; Fekete, A.; Horneck, G.; Kovács, G.; Panitz, C.

2015-01-01

The aim of our experiment Phage and Uracil Response was to extend the use of bacteriophage T7 and uracil biological dosimeters for measuring the biologically effective ultraviolet (UV) dose in the harsh extraterrestrial radiation conditions. The biological detectors were exposed in vacuum-tightly cases in the European Space Agency (ESA) astrobiological exposure facility attached to the external platform of Zvezda (EXPOSE-R). EXPOSE-R took off to the International Space Station (ISS) in November 2008 and was installed on the External platform of the Russian module Zvezda of the ISS in March 2009. Our goal was to determine the dose-effect relation for the formation of photoproducts (i.e. damage to phage DNA and uracil, respectively). The extraterrestrial solar UV radiation ranges over the whole spectrum from vacuum-UV (λ<200 nm) to UVA (315 nm<λ<400 nm), which causes photolesions (photoproducts) in the nucleic acids/their components either by photoionization or excitation. However, these wavelengths cause not only photolesions but in a wavelength-dependent efficiency the reversion of some photolesions, too. Our biological detectors measured in situ conditions the resultant of both reactions induced by the extraterrestrial UV radiation. From this aspect the role of the photoreversion in the extension of the biological UV dosimetry are discussed.

CD14 and TLR4 are expressed early in tammar (Macropus eugenii) neonate development.

PubMed

Daly, Kerry A; Lefévre, Christophe; Nicholas, Kevin; Deane, Elizabeth; Williamson, Peter

2008-04-01

Marsupials are born in a relatively underdeveloped state and develop during a period of intensive maturation in the postnatal period. During this period, the young marsupial lacks a competent immune system, but manages to survive despite the potential of exposure to environmental pathogens. Passive immune transfer via the milk is one well-recognised strategy to compensate the neonate, but there also may be innate immune mechanisms in place. In this study, CD14 and Toll-like receptor 4 (TLR4), integral molecular components of pathogen recognition, were identified and characterised for the first time in a marsupial, the tammar wallaby (Macropus eugenii). Functional motifs of tammar CD14 and the toll/interleukin receptor (TIR) domain of TLR4 were highly conserved. The lipopolysaccharide (LPS) binding residues and the TLR4 interaction site of CD14 were conserved in all marsupials. The TIR signalling domain had 84% identity within marsupials and 77% with eutherians. Stimulation of adult tammar leukocytes resulted in the induction of a biphasic pattern of CD14 and TLR4 expression, and coincided with increased production of the pro-inflammatory cytokine TNF-alpha. Differential patterns of expression of CD14 and TLR4 were observed in tammar pouch young early in development, suggesting that early maturation of the innate immune system in these animals may have developed as an immune survival strategy to protect the marsupial neonate from exposure to microbial pathogens.

The interphotoreceptor retinoid binding protein gene in therian mammals: Implications for higher level relationships and evidence for loss of function in the marsupial mole

PubMed Central

Springer, Mark S.; Burk, Angela; Kavanagh, John R.; Waddell, Victor G.; Stanhope, Michael J.

1997-01-01

The subclass Theria of Mammalia includes marsupials (infraclass Metatheria) and placentals (infraclass Eutheria). Within each group, interordinal relationships remain unclear. One limitation of many studies is incomplete ordinal representation. Here, we analyze DNA sequences for part of exon 1 of the interphotoreceptor retinoid binding protein gene, including 10 that are newly reported, for representatives of all therian orders. Among placentals, the most robust clades are Cetartiodactyla, Paenungulata, and an expanded African clade that includes paenungulates, tubulidentates, and macroscelideans. Anagalida, Archonta, Altungulata, Hyracoidea + Perissodactyla, Ungulata, and the “flying primate” hypothesis are rejected by statistical tests. Among marsupials, the most robust clade includes all orders except Didelphimorphia. The phylogenetic placement of the monito del monte and the marsupial mole remains unclear. However, the marsupial mole sequence contains three frameshift indels and numerous stop codons in all three reading frames. Given that the interphotoreceptor retinoid binding protein gene is a single-copy gene that functions in the visual cycle and that the marsupial mole is blind with degenerate eyes, this finding suggests that phenotypic degeneration of the eyes is accompanied by parallel changes at the molecular level as a result of relaxed selective constraints. PMID:9391099

Blood and small intestine cell kinetics under radiation exposures: Mathematical modeling

NASA Astrophysics Data System (ADS)

Smirnova, O. A.

2009-12-01

Mathematical models which describe the dynamics of two vital body systems (hematopoiesis and small intestinal epithelium) in mammals exposed to acute and chronic radiation are developed. These models, based on conventional biological theories, are implemented as systems of nonlinear differential equations. Their variables and constant parameters have clear biological meaning, that provides successful identification and verification of the models in hand. It is shown that the predictions of the models qualitatively and quantitatively agree with the respective experimental data for small laboratory animals (mice, rats) exposed to acute/chronic irradiation in wide ranges of doses and dose rates. The explanation of a number of radiobiological effects, including those of the low-level long-term exposures, is proposed proceeding from the modeling results. All this bears witness to the validity of employment of the developed models, after a proper identification, in investigation and prediction of radiation effects on the hematopoietic and small intestinal epithelium systems in various mammalian species, including humans. In particular, the models can be used for estimating effects of irradiation on astronauts in the long-term space missions, such as Lunar colonies and Mars voyages.

Strength of small-diameter round and tapered bending members

Treesearch

Ron Wolfe; Joe Murphy

2005-01-01

An early focus on structural use of processed rather than round timber resulted in an underestimation of the structural advantages of retaining the natural form of small-diameter round timber. In the round and tapered form, timbers are not susceptible to the strength-reducing effects of diving grain and exposed juvenile wood. Fiber continuity around knots on the...

Effect of microstructure on the corrosion of CVD-SiC exposed to supercritical water

NASA Astrophysics Data System (ADS)

Tan, L.; Allen, T. R.; Barringer, E.

2009-10-01

Silicon carbide (SiC) is an important engineering material being studied for potential use in multiple nuclear energy systems including high-temperature gas-cooled reactors and water-cooled reactors. The corrosion behavior of SiC exposed to supercritical water (SCW) is critical for examining its applications in nuclear reactors. Although the hydrothermal corrosion of SiC has been the subject of many investigations, the study on the microstructural effects on the corrosion is limited. This paper presents the effect of residual strain, grain size, grain boundary types, and surface orientations on the corrosion of chemical vapor deposited (CVD) β-SiC exposed to SCW at 500 °C and 25 MPa. Weight loss occurred on all the samples due to localized corrosion. Residual strains associated with small grains showed the most significant effect on the corrosion compared to the other factors.

Atrial and ventricular septal changes in ethanol vapour exposed chick embryos.

PubMed

Kamran, Kiran; Khan, Muhammad Yunus; Minhas, Liaqat Ali

2015-03-01

To study the effects of ethanol vapour exposure on development of atrial and ventricular septa of chick embryo. The experimental study was conducted at the College of Physicians and Surgeons, Islamabad, from 2006 to 2007. The experimental and control groups were further divided into three subgroups based on the day of sacrifice. The experimental group was exposed to ethanol vapours produced in a specially-designed vapour chamber and then compared with age-matched controls. There were 90 eggs in each of the two groups. The development of inter-ventricular septum completed at day 7 of development in chick embryo. Ethanol vapour exposure produced a small discontinuity at day 10 of development in a chick embryo which may be labelled as ventricular septal defect since ventricular development is completed by day 7. Interatrial septum formed till day 7 with small perforations which persisted till hatching. Ethanol vapour exposure may lead to ventricular septal defect.

9 CFR 78.32 - Brucellosis exposed swine.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Brucellosis exposed swine. 78.32... Restrictions on Interstate Movement of Swine Because of Brucellosis § 78.32 Brucellosis exposed swine. (a) Brucellosis exposed swine may be moved interstate only if accompanied by a permit and only for immediate...

9 CFR 78.32 - Brucellosis exposed swine.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Brucellosis exposed swine. 78.32... Restrictions on Interstate Movement of Swine Because of Brucellosis § 78.32 Brucellosis exposed swine. (a) Brucellosis exposed swine may be moved interstate only if accompanied by a permit and only for immediate...

9 CFR 78.32 - Brucellosis exposed swine.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Brucellosis exposed swine. 78.32... Restrictions on Interstate Movement of Swine Because of Brucellosis § 78.32 Brucellosis exposed swine. (a) Brucellosis exposed swine may be moved interstate only if accompanied by a permit and only for immediate...

9 CFR 78.32 - Brucellosis exposed swine.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Brucellosis exposed swine. 78.32... Restrictions on Interstate Movement of Swine Because of Brucellosis § 78.32 Brucellosis exposed swine. (a) Brucellosis exposed swine may be moved interstate only if accompanied by a permit and only for immediate...

9 CFR 78.32 - Brucellosis exposed swine.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Brucellosis exposed swine. 78.32... Restrictions on Interstate Movement of Swine Because of Brucellosis § 78.32 Brucellosis exposed swine. (a) Brucellosis exposed swine may be moved interstate only if accompanied by a permit and only for immediate...

Lung cancer incidence and survival in chromium exposed individuals with respect to expression of anti-apoptotic protein survivin and tumor suppressor P53 protein

PubMed Central

2010-01-01

Objective Workers chronically exposed to hexavalent chromium have elevated risk of lung cancer. Our study investigates the incidence of lung cancer types, age at onset of the disease, and survival time among chromium exposed workers with respect to the expression of anti-apoptotic p53 and pro-apoptotic survivin proteins. Materials and methods 67 chromium exposed workers and 104 male controls diagnosed with lung cancer were analyzed. The mean exposure time among workers was 16.7 ± 10.0(SD) years (range 1- 41 years). To investigate the possible regulation of survivin by p53 we examined the expression of both proteins using immohistochemical visualization. Results Chromium exposure significantly decreases the age of onset of the disease by 3.5 years (62.2 ± 9.1 in the exposed group vs. 65.7 ± 10.5 years in controls; P = 0.018). Small cell lung carcinoma (SCLC) amounted for 25.4% of all cases in chromium exposed workers and for 16.3% in non-exposed individuals. The mean survival time in the exposed group was 9.0 ± 12.7 vs. 12.1 ± 21.9 months in controls, but this difference was not significant. Survivin was predominantly expressed in both cell nucleus and cytoplasm, whereas p53 was expressed in the nucleus. There was a negative correlation between survivin and p53 expression. A decreased intensity of expression and fewer cells positive for survivin was detected in SCLC compared with other types of lung cancer. P53 was expressed in 94.1% and survivin in 79.6% of the samples analyzed. Conclusion The study calls attention to decreased expression of survivin, as opposed to p53, in small cell lung carcinoma. PMID:21147621

Normal Modes Expose Active Sites in Enzymes.

PubMed

Glantz-Gashai, Yitav; Meirson, Tomer; Samson, Abraham O

2016-12-01

Accurate prediction of active sites is an important tool in bioinformatics. Here we present an improved structure based technique to expose active sites that is based on large changes of solvent accessibility accompanying normal mode dynamics. The technique which detects EXPOsure of active SITes through normal modEs is named EXPOSITE. The technique is trained using a small 133 enzyme dataset and tested using a large 845 enzyme dataset, both with known active site residues. EXPOSITE is also tested in a benchmark protein ligand dataset (PLD) comprising 48 proteins with and without bound ligands. EXPOSITE is shown to successfully locate the active site in most instances, and is found to be more accurate than other structure-based techniques. Interestingly, in several instances, the active site does not correspond to the largest pocket. EXPOSITE is advantageous due to its high precision and paves the way for structure based prediction of active site in enzymes.

Normal Modes Expose Active Sites in Enzymes

PubMed Central

Glantz-Gashai, Yitav; Samson, Abraham O.

2016-01-01

Accurate prediction of active sites is an important tool in bioinformatics. Here we present an improved structure based technique to expose active sites that is based on large changes of solvent accessibility accompanying normal mode dynamics. The technique which detects EXPOsure of active SITes through normal modEs is named EXPOSITE. The technique is trained using a small 133 enzyme dataset and tested using a large 845 enzyme dataset, both with known active site residues. EXPOSITE is also tested in a benchmark protein ligand dataset (PLD) comprising 48 proteins with and without bound ligands. EXPOSITE is shown to successfully locate the active site in most instances, and is found to be more accurate than other structure-based techniques. Interestingly, in several instances, the active site does not correspond to the largest pocket. EXPOSITE is advantageous due to its high precision and paves the way for structure based prediction of active site in enzymes. PMID:28002427

Volumetric cerebral characteristics of children exposed to opiates and other substances in utero

PubMed Central

Walhovd, K. B.; Moe, V.; Slinning, K.; Due-Tønnessen, P.; Bjørnerud, A.; Dale, A. M.; van der Kouwe, A.; Quinn, B. T.; Kosofsky, B.; Greve, D.; Fischl, B.

2007-01-01

Morphometric cerebral characteristics were studied in children with prenatal poly-substance exposure (n =14) compared to controls (n = 14) without such exposure. Ten of the substance exposed children were born to mothers who used opiates (heroin) throughout the pregnancy. Groups were compared across 16 brain measures: cortical gray matter, cerebral white matter, hippocampus, amygdala, thalamus, accumbens area, caudate, putamen, pallidum, brainstem, cerebellar cortex, cerebellar white matter, lateral ventricles, inferior lateral ventricles, and the 3rd and 4th ventricles. In addition, continuous measurement of thickness across the entire cortical mantle was performed. Volumetric characteristics were correlated with ability and questionnaire assessments 2 years prior to scan. Compared to controls, the substance-exposed children had smaller intracranial and brain volumes, including smaller cerebral cortex, amygdala, accumbens area, putamen, pallidum, brainstem, cerebellar cortex, cerebellar white matter, and inferior lateral ventricles, and thinner cortex of the right anterior cingulate and lateral orbitofrontal cortex. Pallidum and putamen appeared especially reduced in the subgroup exposed to opiates. Only volumes of the right anterior cingulate, the right lateral orbitofrontal cortex and the accumbens area, showed some association with ability and questionnaire measures. The sample studied is rare, and hence small, so conclusions cannot be drawn with certainty. Morphometric group differences were observed, but associations with previous behavioral assessment were generally weak. Some of the volumetric differences, particularly thinner cortex in part of the right lateral orbitofrontal cortex, may be moderately involved in cognitive and behavioral difficulties more frequently experienced by opiate and poly-substance exposed children. PMID:17513131

Isolation and amino acid sequences of opossum vasoactive intestinal polypeptide and cholecystokinin octapeptide.

PubMed Central

Eng, J; Yu, J; Rattan, S; Yalow, R S

1992-01-01

Evolutionary history suggests that the marsupials entered South America from North America about 75 million years ago and subsequently dispersed into Australia before the separation between South America and Antarctica-Australia. A question of interest is whether marsupial peptides resemble the corresponding peptides of Old or New World mammals. Previous studies had shown that "little" gastrin of the North American marsupial, the opossum, is identical in length to that of the New World mammals, the guinea pig and chinchilla. In this report, we demonstrate that opossum cholecystokinin octapeptide, like that of the Australian marsupials, the Eastern quoll and the Tamar wallaby, is identical to the cholecystokinin octapeptide of Old World mammals and differs from that of the guinea pig and chinchilla. However, opossum vasoactive intestinal polypeptide differs from the usual Old World mammalian vasoactive intestinal polypeptide in five sites: [sequence; see text]. PMID:1542675

Corticobulbar fibres in the North American opossum (Didelphis marsupialis virginiana) with notes on the Tasmanian brust-tailed possum (Trichosurus vulpecula) and other marsupials.

PubMed Central

Martin, G F; Bresnahan, J C; Henkel, C K; Megirian, D

1975-01-01

Corticobulbar projections have been studied in the American opossum by both degeneration and autoradiographic methods and, for the most part, the results confirm our earlier observations (Martin & West, 1967; Martin, 1968). However, we have obtained evidence for certain connexions not previously described and have delineated the origin(s) of several connexions more precisely by paying particular attention to the degeneration present at thalamic levels in all cases and by the use of autoradiography. When our results are collated and correlated with new somatosensory cortical maps arrived at by microelectrode techniques (Pubols et al. 1975), it is obvious that corticolbulbar connexions in the North American opossum are remarkably similar to those in the monkey and differ mainly in quantity, relative origins and distribution and in the fact that some of them arise from spatially co-extensive motor-sensory areas (Lende, 1963a, b). In the light of our findings on the American opossum we have examined a large collection of brush-tailed possum material (as well as some from the potoroo and Tasmanian native cat) and have been able to extend our previous findings (Martin et al. 1971; Martin & Megirian, 1972) to a more precise evaluation of the origin of projections from the limb, face motor-sensory cortex. Differences between these representatives of the marsupial radiation, as well as features which are common to all, are described. Images Fig. 1 Fig. 2 Fig. 23 Fig. 24 Fig. 25 Fig. 26 Fig. 27 Fig. 28 Fig. 29 Fig. 30 Fig. 31 Fig. 32 Fig. 33 Fig. 34 Fig. 35 Fig. 36 Fig. 37 Fig. 38 PMID:1213949

Histopathological changes in Wistar albino rats exposed to aqueous extract of unripe Carica papaya.

PubMed

Oduola, Taofeeq; Bello, Ibrahim; Idowu, Thomas; Avwioro, Godwin; Adeosun, Ganiyu; Olatubosun, Luqman

2010-05-01

Exposure of animals to xenobiotics may or may not trigger adverse response at cellular levels. Aqueous extract of unripe Carica papaya is consumed by sickle cell patients as antisickling agent in Western Nigeria. This study was undertaken to investigate the effects of Carica papaya on certain organs in Wister albino rats exposed to aqueous extract of unripe Carica papaya. Different doses of aqueous extract of unripe Carica papaya were administered orally daily for 42 days to six groups of rats. At the end of exposure, the animals were sacrificed and tissue sections were prepared from livers, kidneys, hearts and small intestines using standard techniques. Histopathological results showed that no pathological changes were observed in tissue sections of experimental animals when compared with tissue sections of the same organs in control animals. No pathological changes were elicited in the organs of rats exposed to aqueous extract of unripe Carica papaya.

Letting the ‘cat’ out of the bag: pouch young development of the extinct Tasmanian tiger revealed by X-ray computed tomography

PubMed Central

Spoutil, Frantisek; Prochazka, Jan; Black, Jay R.; Medlock, Kathryn; Paddle, Robert N.; Knitlova, Marketa; Hipsley, Christy A.

2018-01-01

The Tasmanian tiger or thylacine (Thylacinus cynocephalus) was an iconic Australian marsupial predator that was hunted to extinction in the early 1900s. Despite sharing striking similarities with canids, they failed to evolve many of the specialized anatomical features that characterize carnivorous placental mammals. These evolutionary limitations are thought to arise from functional constraints associated with the marsupial mode of reproduction, in which otherwise highly altricial young use their well-developed forelimbs to climb to the pouch and mouth to suckle. Here we present the first three-dimensional digital developmental series of the thylacine throughout its pouch life using X-ray computed tomography on all known ethanol-preserved specimens. Based on detailed skeletal measurements, we refine the species growth curve to improve age estimates for the individuals. Comparison of allometric growth trends in the appendicular skeleton (fore- and hindlimbs) with that of other placental and marsupial mammals revealed that despite their unique adult morphologies, thylacines retained a generalized early marsupial ontogeny. Our approach also revealed mislabelled specimens that possessed large epipubic bones (vestigial in thylacine) and differing vertebral numbers. All of our generated CT models are publicly available, preserving their developmental morphology and providing a novel digital resource for future studies of this unique marsupial. PMID:29515893

Characterisation of the immune compounds in koala milk using a combined transcriptomic and proteomic approach

PubMed Central

Morris, Katrina M.; O’Meally, Denis; Zaw, Thiri; Song, Xiaomin; Gillett, Amber; Molloy, Mark P.; Polkinghorne, Adam; Belov, Katherine

2016-01-01

Production of milk is a key characteristic of mammals, but the features of lactation vary greatly between monotreme, marsupial and eutherian mammals. Marsupials have a short gestation followed by a long lactation period, and milk constituents vary greatly across lactation. Marsupials are born immunologically naïve and rely on their mother’s milk for immunological protection. Koalas (Phascolarctos cinereus) are an iconic Australian species that are increasingly threatened by disease. Here we use a mammary transcriptome, two milk proteomes and the koala genome to comprehensively characterise the protein components of koala milk across lactation, with a focus on immune constituents. The most abundant proteins were well-characterised milk proteins, including β-lactoglobulin and lactotransferrin. In the mammary transcriptome, 851 immune transcripts were expressed, including immunoglobulins and complement components. We identified many abundant antimicrobial peptides, as well as novel proteins with potential antimicrobial roles. We discovered that marsupial VELP is an ortholog of eutherian Glycam1, and likely has an antimicrobial function in milk. We also identified highly-abundant koala endogenous-retrovirus sequences, identifying a potential transmission route from mother to young. Characterising the immune components of milk is key to understanding protection of marsupial young, and the novel immune compounds identified may have applications in clinical research. PMID:27713568

Reduced sensitivity to MDMA-induced facilitation of social behaviour in MDMA pre-exposed rats.

PubMed

Thompson, Murray R; Callaghan, Paul D; Hunt, Glenn E; McGregor, Iain S

2008-05-15

The acute effects of the party drug 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy") in humans include feelings of love, closeness towards other people and an increased acceptance of others views and feelings. Some evidence suggests that regular MDMA users develop a subsensitivity to the positive effects of the drug and escalate their intake of the drug over time as a result. The current study investigated whether brief exposure to relatively high doses of MDMA in rats produces a subsequent attenuation in the ability of MDMA to enhance social interaction. Male Wistar rats were exposed to either MDMA (4 x 5 mg/kg over 4 h) or vehicle on two consecutive days. Twelve weeks later, MDMA pre-exposed rats displayed a significantly shorter period of time spent in social interaction than controls when tested in the drug-free state. MDMA pre-exposed rats also showed a blunted prosocial response to MDMA (2.5 mg/kg) relative to controls. This difference was overcome by increasing the MDMA dose to 5 mg/kg. The 5-HT(1A) agonist 8-OH-DPAT (250 microg/kg but not 125 microg/kg) increased social interaction and this effect did not differ in MDMA and vehicle pre-exposed rats. HPLC analysis showed a small but significant depletion of prefrontal 5-HT and 5-HIAA in MDMA pre-exposed rats. Prefrontal 5-HIAA concentrations were also reduced in the subset of vehicle and MDMA pre-exposed rats that received additional testing with MDMA. These results indicate that treatment with MDMA not only causes lasting reductions in social interaction in rats but causes an attenuation of the prosocial effects of subsequent MDMA administration. The lack of a differential response to 8-OH-DPAT agrees with other findings that the 5-HT(1A) receptor system remains functionally intact following MDMA pre-exposure and suggests that other neuroadaptations may underlie the lasting social deficits caused by MDMA.

Hormonal Perturbations in Occupationally Exposed Nickel Workers

PubMed Central

Beshir, Safia; Ibrahim, Khadiga Salah; Shaheen, Weam; Shahy, Eman M.

2016-01-01

BACKGROUND: Nickel exposure is recognized as an endocrine disruptor because of its adverse effects on reproduction. AIM: This study was designed to investigate the possible testiculo-hormonal perturbations on workers occupationally exposed to nickel and to assess its effects on human male sexual function. METHODS: Cross-sectional comparative study, comprising 105 electroplating male non-smoker, non-alcoholic workers exposed to soluble nickel and 60 controls was done. Serum luteinizing hormone, follicle stimulating hormone, testosterone levels and urinary nickel concentrations were determined for the studied groups. RESULTS: Serum luteinizing hormone, follicle stimulating hormone, urinary nickel and the simultaneous incidence of more than one sexual disorder were significantly higher in the exposed workers compared to controls. The occurrence of various types of sexual disorders (decreased libido, impotence and premature ejaculation) in the exposed workers was 9.5, 5.1 and 4.4 folds respectively than the controls. CONCLUSIONS: Exposure to nickel produces possible testiculo-hormonal perturbations in those exposed workers. PMID:27335607

Virtual Reconstruction and Prey Size Preference in the Mid Cenozoic Thylacinid, Nimbacinus dicksoni (Thylacinidae, Marsupialia)

PubMed Central

Attard, Marie R. G.; Parr, William C. H.; Wilson, Laura A. B.; Archer, Michael; Hand, Suzanne J.; Rogers, Tracey L.; Wroe, Stephen

2014-01-01

Thylacinidae is an extinct family of Australian and New Guinean marsupial carnivores, comprizing 12 known species, the oldest of which are late Oligocene (∼24 Ma) in age. Except for the recently extinct thylacine (Thylacinus cynocephalus), most are known from fragmentary craniodental material only, limiting the scope of biomechanical and ecological studies. However, a particularly well-preserved skull of the fossil species Nimbacinus dicksoni, has been recovered from middle Miocene (∼16-11.6 Ma) deposits in the Riversleigh World Heritage Area, northwestern Queensland. Here, we ask whether N. dicksoni was more similar to its recently extinct relative or to several large living marsupials in a key aspect of feeding ecology, i.e., was N. dicksoni a relatively small or large prey specialist. To address this question we have digitally reconstructed its skull and applied three-dimensional Finite Element Analysis to compare its mechanical performance with that of three extant marsupial carnivores and T. cynocephalus. Under loadings adjusted for differences in size that simulated forces generated by both jaw closing musculature and struggling prey, we found that stress distributions and magnitudes in the skull of N. dicksoni were more similar to those of the living spotted-tailed quoll (Dasyurus maculatus) than to its recently extinct relative. Considering the Finite Element Analysis results and dental morphology, we predict that N. dicksoni likely occupied a broadly similar ecological niche to that of D. maculatus, and was likely capable of hunting vertebrate prey that may have exceeded its own body mass. PMID:24718109

[Psychological and neurobehavioral effects of aluminum on exposed workers].

PubMed

Guo, G; Ma, H; Wang, X

1998-09-01

To explore neurotoxicity and the changes in psychological and neurobehavioral functions in workers exposed to aluminum. Psychological status and neurobehavioral functions of 103 exposed workers and 64 controls were examined with Neurobehavioral Core Test Battery recommended by World Health Organization (WHO), and meanwhile, air concentrations of aluminum in the workplaces and urine levels of aluminum in the exposed workers were determined. Urine levels of aluminum in the exposed workers were markedly higher than those in non-exposed controls, with a statistical significance. Scores for tension, depression, anger, fatigue and confusion in the workers exposed to aluminum for more than ten years were significantly more than those in non-exposed controls. Scores of the performance of Santa Ana, digit symbol and pursuit aiming in the former were significantly lower, and no other changes in psychological and behavioral functions was found in workers exposed for less than ten years, except for their scores of pursuit aiming. Obvious changes in psychological status, neuromotor speed and their accuracy were observed in workers exposed to aluminum for a long term.

THE GOOD, THE BAD, AND THE TOXIC: APPROACHING HORMESIS IN DAPHNIA MAGNA EXPOSED TO AN ENERGETIC COMPOUND

PubMed Central

Stanley, Jacob K.; Perkins, Edward J.; Habib, Tanwir; Sims, Jerre G.; Chappell, Pornsawan; Escalon, B. Lynn; Wilbanks, Mitchell; Garcia-Reyero, Natàlia

2014-01-01

A hormetic response is characterized by an opposite effect in small and large doses of chemical exposure, often resulting in seemingly beneficial effects at low doses. Here, we examined the potential mechanisms underlying the hormetic response of Daphnia magna to the energetic trinitrotoluene (TNT). Daphnia magna were exposed to TNT for 21 days and a significant increase in adult length and number of neonates was identified at low concentrations (0.002 – 0.22 mg/L TNT) while toxic effects were identified at high concentrations (0.97 mg/L TNT and above). Microarray analysis of D. magna exposed to 0.004, 0.12, and 1.85 mg/L TNT identified effects on lipid metabolism as a potential mechanism underlying hormetic effects. Lipidomic analysis of exposed D. magna supported the hypothesis that TNT exposure affected lipid and fatty acid metabolism, showing that hormetic effects could be related to changes in polyunsaturated fatty acids known to be involved in Daphnia growth and reproduction. Our results show that Daphnia exposed to low levels of TNT presented hormetic growth and reproduction enhancement while higher TNT concentrations had an opposite effect. Our results also show how a systems approach can help elucidate potential mechanisms of action and adverse outcomes. PMID:23898970

Field Testing of a Small Water Purification System for Non-PRASA Rural Communities

EPA Science Inventory

Small, rural communities typically do not have adequate water purification systems to sustain their life quality and residents are exposed to pathogens present in drinking water. In Puerto Rico (PR), approximately 4% of the population does not have access to drinking water provi...

A Review of Events That Expose Children to Elemental Mercury in the United States

PubMed Central

Lee, Robin; Middleton, Dan; Caldwell, Kathleen; Dearwent, Steve; Jones, Steven; Lewis, Brian; Monteilh, Carolyn; Mortensen, Mary Ellen; Nickle, Richard; Orloff, Kenneth; Reger, Meghan; Risher, John; Rogers, Helen Schurz; Watters, Michelle

2009-01-01

Objective Concern for children exposed to elemental mercury prompted the Agency for Toxic Substances and Disease Registry and the Centers for Disease Control and Prevention to review the sources of elemental mercury exposures in children, describe the location and proportion of children affected, and make recommendations on how to prevent these exposures. In this review, we excluded mercury exposures from coal-burning facilities, dental amalgams, fish consumption, medical waste incinerators, or thimerosal-containing vaccines. Data sources We reviewed federal, state, and regional programs with information on mercury releases along with published reports of children exposed to elemental mercury in the United States. We selected all mercury-related events that were documented to expose (or potentially expose) children. We then explored event characteristics (i.e., the exposure source, location). Data synthesis Primary exposure locations were at home, at school, and at other locations such as industrial property not adequately remediated or medical facilities. Exposure to small spills from broken thermometers was the most common scenario; however, reports of such exposures are declining. Discussion and conclusions Childhood exposures to elemental mercury often result from inappropriate handling or cleanup of spilled mercury. The information reviewed suggests that most releases do not lead to demonstrable harm if the exposure period is short and the mercury is properly cleaned up. Recommendations Primary prevention should include health education and policy initiatives. For larger spills, better coordination among existing surveillance systems would assist in understanding the risk factors and in developing effective prevention efforts. PMID:19590676

Toxicological responses of red-backed salamander (Plethodon cinereus) exposed to aged and amended soils containing lead.

PubMed

Bazar, Matthew A; Quinn, Michael J; Mozzachio, Kristie; Bleiler, John A; Archer, Christine R; Phillips, Carlton T; Johnson, Mark S

2010-05-01

The use of lead in military and civilian small arms projectiles is widely acknowledged to have resulted in high soil lead concentrations at many small arms ranges. These ranges are often adjacent to wildlife habitat or have become habitat when no longer used. To assess the potential toxicity of lead to terrestrial amphibians in contaminated areas, we exposed 100 red-backed salamanders (Plethodon cinereus) to either a control soil or one of four soil treatments amended with lead acetate for 28 days. Analytical mean soil concentrations were 14 (control), 553, 1700, 4700, and 9167 mg Pb/kg soil dry weight. An additional 60 salamanders were also exposed for 28 days to one of six field-collected soil samples from a small arms range and a skeet range. The field soil concentrations ranged from 11 (background) to 16,967 mg Pb/kg soil dry weight. Food consisted of uncontaminated flightless Drosophila melanogaster. Salamander survival was reduced in amended soil treatments of 4700 and 9167 mg/kg by 15% and 80%, respectively. Inappetence was observed at 4700 and 9167 mg/kg and growth decreased in the 9167 mg/kg treatment. Total white blood cells decreased 32% at 4700 mg/kg compared to controls and were 22% lower in the 9167 mg/kg treatment. In contrast, survival was 100% for all field-collected soils with no hematological effects. At 16,967 mg/kg there was evidence of soil avoidance and decreased growth. These data suggest marked differences in toxicity and bioavailability of the lead-amended soil in contrast to the field-collected soil containing lead.

Animal cruelty by children exposed to domestic violence.

PubMed

Currie, Cheryl L

2006-04-01

The first objective of this study was to determine if children exposed to domestic violence were significantly more likely to be cruel to animals than children not exposed to violence. The second was to determine if there were significant age and gender differences between children who were and were not cruel to animals. A community sample of 47 mothers with two children and a history of domestic violence were compared to a matched sample of 45 mothers with two children who did not have such a history. Children exposed to domestic violence were significantly more likely to have been cruel to animals than children not exposed to violence. The age and gender of children who were cruel to animals did not differ from children who were not cruel to animals. However, exposed children cruel to animals were significantly older than non-exposed children cruel to animals. Animal cruelty by children is correlated with exposure to domestic violence.

Long-term clearance from small airways in subjects with ciliary dysfunction.

PubMed

Lindström, Maria; Falk, Rolf; Hjelte, Lena; Philipson, Klas; Svartengren, Magnus

2006-05-20

The objective of this study was to investigate if long-term clearance from small airways is dependent on normal ciliary function. Six young adults with primary ciliary dyskinesia (PCD) inhaled 111 Indium labelled Teflon particles of 4.2 microm geometric and 6.2 microm aerodynamic diameter with an extremely slow inhalation flow, 0.05 L/s. The inhalation method deposits particles mainly in the small conducting airways. Lung retention was measured immediately after inhalation and at four occasions up to 21 days after inhalation. Results were compared with data from ten healthy controls. For additional comparison three of the PCD subjects also inhaled the test particles with normal inhalation flow, 0.5 L/s, providing a more central deposition. The lung retention at 24 h in % of lung deposition (Ret24) was higher (p < 0.001) in the PCD subjects, 79 % (95% Confidence Interval, 67.6;90.6), compared to 49% (42.3;55.5) in the healthy controls. There was a significant clearance after 24 h both in the PCD subjects and in the healthy controls with equivalent clearance. The mean Ret24 with slow inhalation flow was 73.9 +/- 1.9% compared to 68.9 +/- 7.5% with normal inhalation flow in the three PCD subjects exposed twice. During day 7-21 the three PCD subjects exposed twice cleared 9% with normal flow, probably representing predominantly alveolar clearance, compared to 19% with slow inhalation flow, probably representing mainly small airway clearance. This study shows that despite ciliary dysfunction, clearance continues in the small airways beyond 24 h. There are apparently additional clearance mechanisms present in the small airways.

Eye Lens Opacities Among Physicians Occupationally Exposed to Ionizing Radiation.

PubMed

Auvinen, Anssi; Kivelä, Tero; Heinävaara, Sirpa; Mrena, Samy

2015-08-01

We compared the frequency of lens opacities among physicians with and without occupational exposure to ionizing radiation, and estimated dose-response between cumulative dose and opacities. We conducted ophthalmologic examinations of 21 physicians with occupational exposure to radiation and 16 unexposed physicians. Information on cumulative radiation doses (mean 111 mSv) was based on dosimeter readings recorded in a national database on occupational exposures. Lens changes were evaluated using the Lens Opacities Classification System II, with an emphasis on posterior subcapsular (PSC) and cortical changes. Among the exposed physicians, the prevalences of cortical and PSC changes were both 11% (3/21), and the corresponding frequencies in the unexposed group were 44% (n = 7) and 6% (n = 1). For dose-response analysis, the data were pooled with 29 exposed physicians from our previous study. No association of either type of lens changes with cumulative recorded dose was observed. Our findings do not indicate an increased frequency of lens opacities in physicians with occupational exposure to ionizing radiation. However, the subjects in this study have received relatively low doses and therefore the results do not exclude small increases in lens opacities or contradict the studies reporting increases among interventional cardiologists with materially higher cumulative doses. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Small-Scale Smart Grid Construction and Analysis

NASA Astrophysics Data System (ADS)

Surface, Nicholas James

The smart grid (SG) is a commonly used catch-phrase in the energy industry yet there is no universally accepted definition. The objectives and most useful concepts have been investigated extensively in economic, environmental and engineering research by applying statistical knowledge and established theories to develop simulations without constructing physical models. In this study, a small-scale version (SSSG) is constructed to physically represent these ideas so they can be evaluated. Results of construction show data acquisition three times more expensive than the grid itself although mainly due to the incapability to downsize 70% of data acquisition costs to small-scale. Experimentation on the fully assembled grid exposes the limitations of low cost modified sine wave power, significant enough to recommend pure sine wave investment in future SSSG iterations. Findings can be projected to full-size SG at a ratio of 1:10, based on the appliance representing average US household peak daily load. However this exposes disproportionalities in the SSSG compared with previous SG investigations and recommended changes for future iterations are established to remedy this issue. Also discussed are other ideas investigated in the literature and their suitability for SSSG incorporation. It is highly recommended to develop a user-friendly bidirectional charger to more accurately represent vehicle-to-grid (V2G) infrastructure. Smart homes, BEV swap stations and pumped hydroelectric storage can also be researched on future iterations of the SSSG.

Survival of Spores of Trichoderma longibrachiatum in Space: data from the Space Experiment SPORES on EXPOSE-R

NASA Astrophysics Data System (ADS)

Neuberger, Katja; Lux-Endrich, Astrid; Panitz, Corinna

2015-01-01

In the space experiment `Spores in artificial meteorites' (SPORES), spores of the fungus Trichoderma longibrachiatum were exposed to low-Earth orbit for nearly 2 years on board the EXPOSE-R facility outside of the International Space Station. The environmental conditions tested in space were: space vacuum at 10-7-10-4 Pa or argon atmosphere at 105 Pa as inert gas atmosphere, solar extraterrestrial ultraviolet (UV) radiation at λ > 110 nm or λ > 200 nm with fluences up to 5.8 × 108 J m-2, cosmic radiation of a total dose range from 225 to 320 mGy, and temperature fluctuations from -25 to +50°C, applied isolated or in combination. Comparable control experiments were performed on ground. After retrieval, viability of spores was analysed by two methods: (i) ethidium bromide staining and (ii) test of germination capability. About 30% of the spores in vacuum survived the space travel, if shielded against insolation. However, in most cases no significant decrease was observed for spores exposed in addition to the full spectrum of solar UV irradiation. As the spores were exposed in clusters, the outer layers of spores may have shielded the inner part. The results give some information about the likelihood of lithopanspermia, the natural transfer of micro-organisms between planets. In addition to the parameters of outer space, sojourn time in space seems to be one of the limiting parameters.

Expansion of CORE-SINEs in the genome of the Tasmanian devil

PubMed Central

2012-01-01

Background The genome of the carnivorous marsupial, the Tasmanian devil (Sarcophilus harrisii, Order: Dasyuromorphia), was sequenced in the hopes of finding a cure for or gaining a better understanding of the contagious devil facial tumor disease that is threatening the species’ survival. To better understand the Tasmanian devil genome, we screened it for transposable elements and investigated the dynamics of short interspersed element (SINE) retroposons. Results The temporal history of Tasmanian devil SINEs, elucidated using a transposition in transposition analysis, indicates that WSINE1, a CORE-SINE present in around 200,000 copies, is the most recently active element. Moreover, we discovered a new subtype of WSINE1 (WSINE1b) that comprises at least 90% of all Tasmanian devil WSINE1s. The frequencies of WSINE1 subtypes differ in the genomes of two of the other Australian marsupial orders. A co-segregation analysis indicated that at least 66 subfamilies of WSINE1 evolved during the evolution of Dasyuromorphia. Using a substitution rate derived from WSINE1 insertions, the ages of the subfamilies were estimated and correlated with a newly established phylogeny of Dasyuromorphia. Phylogenetic analyses and divergence time estimates of mitochondrial genome data indicate a rapid radiation of the Tasmanian devil and the closest relative the quolls (Dasyurus) around 14 million years ago. Conclusions The radiation and abundance of CORE-SINEs in marsupial genomes indicates that they may be a major player in the evolution of marsupials. It is evident that the early phases of evolution of the carnivorous marsupial order Dasyuromorphia was characterized by a burst of SINE activity. A correlation between a speciation event and a major burst of retroposon activity is for the first time shown in a marsupial genome. PMID:22559330

Expansion of CORE-SINEs in the genome of the Tasmanian devil.

PubMed

Nilsson, Maria A; Janke, Axel; Murchison, Elizabeth P; Ning, Zemin; Hallström, Björn M

2012-05-06

The genome of the carnivorous marsupial, the Tasmanian devil (Sarcophilus harrisii, Order: Dasyuromorphia), was sequenced in the hopes of finding a cure for or gaining a better understanding of the contagious devil facial tumor disease that is threatening the species' survival. To better understand the Tasmanian devil genome, we screened it for transposable elements and investigated the dynamics of short interspersed element (SINE) retroposons. The temporal history of Tasmanian devil SINEs, elucidated using a transposition in transposition analysis, indicates that WSINE1, a CORE-SINE present in around 200,000 copies, is the most recently active element. Moreover, we discovered a new subtype of WSINE1 (WSINE1b) that comprises at least 90% of all Tasmanian devil WSINE1s. The frequencies of WSINE1 subtypes differ in the genomes of two of the other Australian marsupial orders. A co-segregation analysis indicated that at least 66 subfamilies of WSINE1 evolved during the evolution of Dasyuromorphia. Using a substitution rate derived from WSINE1 insertions, the ages of the subfamilies were estimated and correlated with a newly established phylogeny of Dasyuromorphia. Phylogenetic analyses and divergence time estimates of mitochondrial genome data indicate a rapid radiation of the Tasmanian devil and the closest relative the quolls (Dasyurus) around 14 million years ago. The radiation and abundance of CORE-SINEs in marsupial genomes indicates that they may be a major player in the evolution of marsupials. It is evident that the early phases of evolution of the carnivorous marsupial order Dasyuromorphia was characterized by a burst of SINE activity. A correlation between a speciation event and a major burst of retroposon activity is for the first time shown in a marsupial genome.

An empirical assessment and comparison of species-based and habitat-based surrogates: a case study of forest vertebrates and large old trees.

PubMed

Lindenmayer, David B; Barton, Philip S; Lane, Peter W; Westgate, Martin J; McBurney, Lachlan; Blair, David; Gibbons, Philip; Likens, Gene E

2014-01-01

A holy grail of conservation is to find simple but reliable measures of environmental change to guide management. For example, particular species or particular habitat attributes are often used as proxies for the abundance or diversity of a subset of other taxa. However, the efficacy of such kinds of species-based surrogates and habitat-based surrogates is rarely assessed, nor are different kinds of surrogates compared in terms of their relative effectiveness. We use 30-year datasets on arboreal marsupials and vegetation structure to quantify the effectiveness of: (1) the abundance of a particular species of arboreal marsupial as a species-based surrogate for other arboreal marsupial taxa, (2) hollow-bearing tree abundance as a habitat-based surrogate for arboreal marsupial abundance, and (3) a combination of species- and habitat-based surrogates. We also quantify the robustness of species-based and habitat-based surrogates over time. We then use the same approach to model overall species richness of arboreal marsupials. We show that a species-based surrogate can appear to be a valid surrogate until a habitat-based surrogate is co-examined, after which the effectiveness of the former is lost. The addition of a species-based surrogate to a habitat-based surrogate made little difference in explaining arboreal marsupial abundance, but altered the co-occurrence relationship between species. Hence, there was limited value in simultaneously using a combination of kinds of surrogates. The habitat-based surrogate also generally performed significantly better and was easier and less costly to gather than the species-based surrogate. We found that over 30 years of study, the relationships which underpinned the habitat-based surrogate generally remained positive but variable over time. Our work highlights why it is important to compare the effectiveness of different broad classes of surrogates and identify situations when either species- or habitat-based surrogates are likely

The Value of Countryside Elements in the Conservation of a Threatened Arboreal Marsupial Petaurus norfolcensis in Agricultural Landscapes of South-Eastern Australia—The Disproportional Value of Scattered Trees

PubMed Central

Crane, Mason J.; Lindenmayer, David B.; Cunningham, Ross B.

2014-01-01

Human activities, particularly agriculture, have transformed much of the world's terrestrial environment. Within these anthropogenic landscapes, a variety of relictual and semi-natural habitats exist, which we term countryside elements. The habitat value of countryside elements (hereafter termed ‘elements’) is increasingly recognised. We quantify the relative value of four kinds of such ‘elements’ (linear roadside remnants, native vegetation patches, scattered trees and tree plantings) used by a threatened Australian arboreal marsupial, the squirrel glider (Petaurus norfolcensis). We examined relationships between home range size and the availability of each ‘element’ and whether the usage was relative to predicted levels of use. The use of ‘elements’ by gliders was largely explained by their availability, but there was a preference for native vegetation patches and scattered trees. We found home range size was significantly smaller with increasing area of scattered trees and a contrasting effect with increasing area of linear roadside remnants or native vegetation patches. Our work showed that each ‘element’ was used and as such had a role in the conservation of the squirrel glider, but their relative value varied. We illustrate the need to assess the conservation value of countryside elements so they can be incorporated into the holistic management of agricultural landscapes. This work demonstrates the disproportional value of scattered trees, underscoring the need to specifically incorporate and/or enhance the protection and recruitment of scattered trees in biodiversity conservation policy and management. PMID:25216045

The value of countryside elements in the conservation of a threatened arboreal marsupial Petaurus norfolcensis in agricultural landscapes of south-eastern Australia--the disproportional value of scattered trees.

PubMed

Crane, Mason J; Lindenmayer, David B; Cunningham, Ross B

2014-01-01

Human activities, particularly agriculture, have transformed much of the world's terrestrial environment. Within these anthropogenic landscapes, a variety of relictual and semi-natural habitats exist, which we term countryside elements. The habitat value of countryside elements (hereafter termed 'elements') is increasingly recognised. We quantify the relative value of four kinds of such 'elements' (linear roadside remnants, native vegetation patches, scattered trees and tree plantings) used by a threatened Australian arboreal marsupial, the squirrel glider (Petaurus norfolcensis). We examined relationships between home range size and the availability of each 'element' and whether the usage was relative to predicted levels of use. The use of 'elements' by gliders was largely explained by their availability, but there was a preference for native vegetation patches and scattered trees. We found home range size was significantly smaller with increasing area of scattered trees and a contrasting effect with increasing area of linear roadside remnants or native vegetation patches. Our work showed that each 'element' was used and as such had a role in the conservation of the squirrel glider, but their relative value varied. We illustrate the need to assess the conservation value of countryside elements so they can be incorporated into the holistic management of agricultural landscapes. This work demonstrates the disproportional value of scattered trees, underscoring the need to specifically incorporate and/or enhance the protection and recruitment of scattered trees in biodiversity conservation policy and management.

Safety of Tenofovir Use During Pregnancy: Early Growth Outcomes in HIV-Exposed Uninfected Infants

PubMed Central

SIBERRY, George K.; WILLIAMS, Paige L.; MENDEZ, Hermann; SEAGE, George R.; JACOBSON, Denise L.; HAZRA, Rohan; RICH, Kenneth C.; GRINER, Raymond; TASSIOPOULOS, Katherine; KACANEK, Deborah; MOFENSON, Lynne M.; MILLER, Tracie; DiMEGLIO, Linda A.; WATTS, D. Heather

2012-01-01

Objective To evaluate the association of tenofovir disoproxil fumarate (TDF) use during pregnancy with early growth parameters in HIV-exposed, uninfected (HEU) infants. Design US-based prospective cohort study of HEU children to examine potential adverse effects of prenatal TDF exposure. Methods We evaluated the association of maternal TDF use during pregnancy with small for gestational age (SGA); low birth weight (LBW, <2.5kg); weight-for-age z-scores (WAZ), length-forage z-scores (LAZ) and head circumference-for-age (HCAZ) z-scores at newborn visit; and LAZ, HCAZ, and WAZ at age one year. Logistic regression models for LBW and SGA were fit, adjusting for maternal and sociodemographic factors. Adjusted linear regression models were used to evaluate LAZ, WAZ and HCAZ by TDF exposure. Results Of 2029 enrolled children with maternal antiretroviral information, TDF was used by 449 (21%) HIV-infected mothers, increasing from 14% in 2003 to 43% in 2010. There was no difference between those exposed to combination regimens with versus without TDF for SGA, LBW, and newborn LAZ and HCAZ. However, at age one year, infants exposed to combination regimens with TDF had significantly lower adjusted mean LAZ and HCAZ than those without TDF (LAZ: −0.17 vs. −0.03, p=0.04; HCAZ: 0.17 vs. 0.42, p=0.02). Conclusions TDF use during pregnancy was not associated with increased risk for LBW or SGA. The slightly lower mean LAZ and HCAZ observed at age one year in TDF-exposed infants are of uncertain significance but underscore the need for additional studies of growth outcomes after TDF use during pregnancy. PMID:22382151

Ototoxicity in rats exposed to ethylbenzene and to two technical xylene vapours for 13 weeks.

PubMed

Gagnaire, François; Langlais, Cristina; Grossmann, Stéphane; Wild, Pascal

2007-02-01

Male Sprague-Dawley rats were exposed to ethylbenzene (200, 400, 600 and 800 ppm) and to two mixed xylenes (250, 500, 1,000 and 2,000 ppm total compounds) by inhalation, 6 h/day, 6 days/week for 13 weeks and sacrificed for morphological investigation 8 weeks after the end of exposure. Brainstem auditory-evoked responses were used to determine auditory thresholds at different frequencies. Ethylbenzene produced moderate to severe ototoxicity in rats exposed to the four concentrations studied. Increased thresholds were observed at 2, 4, 8 and 16 kHz in rats exposed to 400, 600 and 800 ppm ethylbenzene. Moderate to severe losses of outer hair cells of the organ of Corti occurred in animals exposed to the four concentrations studied. Exposure to both mixed xylenes produced ototoxicity characterized by increased auditory thresholds and losses of outer hair cells. Ototoxicity potentiation caused by ethylbenzene was observed. Depending on the mixed xylene studied and the area of the concentration-response curves taken into account, the concentrations of ethylbenzene in mixed xylenes necessary to cause a given ototoxicity were 1.7-2.8 times less than those of pure ethylbenzene. Given the high ototoxicity of ethylbenzene, the safety margin of less or equal to two (LOAEL/TWA) might be too small to protect workers from the potential risk of ototoxicity. Moreover, the enhanced ototoxicity of ethylbenzene and para-xylene observed in mixed xylenes should encourage the production of mixed xylenes with the lowest possible concentrations of ethylbenzene and para-xylene.

Leaf photosynthetic and water-relations responses for 'Valencia' orange trees exposed to oxidant air pollution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszyk, D.M.; Takemoto, B.K.; Poe, M.

1991-01-01

Leaf responses were measured to test a hypothesis that reduced photosynthetic capacity and/or altered water relations were associated with reductions in yield for 'Valencia' orange trees (Citrus sinensis (L.), Osbeck) exposed to ambient oxidant air pollution. Exposures were continuous for 4 years to three levels of oxidants (in charcoal-filtered, half-filtered, and non-filtered air). Oxidants had no effect on net leaf photosynthetic rates or on photosynthetic pigment concentrations. A single set of measurements indicated that oxidants increased leaf starch concentrations (24%) prior to flowering, suggesting a change in photosynthate allocation. Leaves exposed to oxidants had small, but consistent, changes in watermore » relations over the summer growing season, compared to trees growing in filtered air. Other changes included decreased stomatal conductance (12%) and transpiration (9%) rates, and increased water pressure potentials (5%). While all responses were subtle, their cumulative impact over 4 years indicated that 'Valencia' orange trees were subject to increased ambient oxidant stress.« less

I. Microwave Apparatus for Exposing Tissue and the Effect of the Radiation on Skin Respiration

PubMed Central

Lawrence, J. C.

1968-01-01

An apparatus was designed which enabled small pieces of skin to be exposed to a uniform field of microwaves at χ-band (8,730 MHz). This was used to investigate the effect of these microwaves at selected energy levels on the metabolism of skin. It was shown that skin cultured in vitro exhibited a graded response to microwave energy, and a doseresponse curve was constructed from this data. The ED50 of this curve was 4,740 mW./sq. cm. applied for 1 second. Microscopical examination of three-day cultures of skin showed that histological abnormalities occurred if the specimens were exposed to intensities of microwaves causing more than 30% respiratory damage. The energy level at the ED30 was 2,880 mW./sq. cm. applied for 1 second. Results were consistent with the hypothesis that tissue damage caused by irradiation with microwaves was due to the energy absorbed by the specimen being converted to heat. PMID:5663427

Small lakes show muted climate change signal in deepwater temperatures

USGS Publications Warehouse

Winslow, Luke A.; Read, Jordan S.; Hansen, Gretchen J. A.; Hanson, Paul C.

2015-01-01

Water temperature observations were collected from 142 lakes across Wisconsin, USA, to examine variation in temperature of lakes exposed to similar regional climate. Whole lake water temperatures increased across the state from 1990 to 2012, with an average trend of 0.042°C yr−1 ± 0.01°C yr−1. In large (>0.5 km2) lakes, the positive temperature trend was similar across all depths. In small lakes (<0.5 km2), the warming trend was restricted to shallow waters, with no significant temperature trend observed in water >0.5 times the maximum lake depth. The differing response of small versus large lakes is potentially a result of wind-sheltering reducing turbulent mixing magnitude in small lakes. These results demonstrate that small lakes respond differently to climate change than large lakes, suggesting that current predictions of impacts to lakes from climate change may require modification.

Cancer mortality among atomic bomb survivors exposed as children.

PubMed

Goto, Hitomi; Watanabe, Tomoyuki; Miyao, Masaru; Fukuda, Hiromi; Sato, Yuzo; Oshida, Yoshiharu

2012-05-01

To compare cancer mortality among A-bomb survivors exposed as children with cancer mortality among an unexposed control group (the entire population of Japan, JPCG). The subjects were the Hiroshima and Nagasaki A-bomb survivor groups (0-14 years of age in 1945) reported in life span study report 12 (follow-up years were from 1950 to 1990), and a control group consisting of the JPCG. We estimated the expected number of deaths due to all causes and cancers of various causes among the exposed survivors who died in the follow-up interval, if they had died with the same mortality as the JPCG (0-14 years of age in 1945). We calculated the standardized mortality ratio (SMR) of A-bomb survivors in comparison with the JPCG. SMRs were significantly higher in exposed boys overall for all deaths, all cancers, leukemia, and liver cancer, and for exposed girls overall for all cancers, solid cancers, liver cancer, and breast cancer. In boys, SMRs were significantly higher for all deaths and liver cancer even in those exposed to very low doses, and for all cancers, solid cancers, and liver cancer in those exposed to low doses. In girls, SMRs were significantly higher for liver cancer and uterine cancer in those exposed to low doses, and for leukemia, solid cancers, stomach cancer, and breast cancer in those exposed to high doses. We calculated the SMRs for the A-bomb survivors versus JPCG in childhood and compared them with a true non-exposed group. A notable result was that SMRs in boys exposed to low doses were significantly higher for solid cancer.

Contaminations of inner surface of magnesium fluoride windows in the `Expose-R' experiment on the International Space Station

NASA Astrophysics Data System (ADS)

Skurat, V. E.

2017-10-01

A series of experiments was carried out previously on board of the International Space Station in `EXPOSE-R', a multi-user expose facility, provided by European Space Agency attached to the external surface of the Russian Segment. In one experiment, spores of microorganisms and species of higher plant seeds, in heat-sealed polymer bags were irradiated by solar radiation passed through MgF2 windows in a high space vacuum. After sample exposure, it was found that in many cases the inner surfaces of windows were contaminated. Analysis of the contamination revealed the presence of chemical groups CH2, CH3, NH, OH, C═O, Si-CH3 (Demets et al. in 2015). Their presence in deposits was explained by photofixation of gaseous precursors - some of the vapours of glues and additives in polymeric materials in the core facility of `Expose-R'. Carbon-, oxygen- and silicon-containing groups may be deposited from outer intrinsic atmosphere. This atmosphere is connected with sample compartments and core facility. However, the presence of NH groups on inner surfaces of windows was not expected. This paper shows that the process responsible for carbon-, nitrogen- and oxygen-containing group formation can be a photopolymerization of caprolactam, which is released from the outer Nylon 6 layer of polymer bags under Solar vacuum ultraviolet radiation.

Small-Group Standardized Patient Encounter Improves Athletic Training Students' Psychosocial Intervention and Referral Skills

ERIC Educational Resources Information Center

Walker, Stacy E.; Weidner, Thomas G.; Thrasher, Ashley B.

2016-01-01

Context: Athletic trainers provide psychological support, counseling, intervention, and referral to patients during clinical practice. However, students are rarely exposed to real-life opportunities to develop these skills. Objective: To determine if a small-group standardized patient (SP) encounter improved athletic training students'…

Mortality of aircraft maintenance workers exposed to trichloroethylene and other hydrocarbons and chemicals: extended follow up

PubMed Central

Radican, Larry; Blair, Aaron; Stewart, Patricia; Wartenberg, Daniel

2009-01-01

Objective To extend follow-up of 14,455 workers from 1990 to 2000, and evaluate mortality risk from exposure to trichloroethylene (TCE) and other chemicals. Methods Multivariable Cox models were used to estimate relative risk for exposed vs. unexposed workers based on previously developed exposure surrogates. Results Among TCE exposed workers, there was no statistically significant increased risk of all-cause mortality (RR=1.04) or death from all cancers (RR=1.03). Exposure-response gradients for TCE were relatively flat and did not materially change since 1990. Statistically significant excesses were found for several chemical exposure subgroups and causes, and were generally consistent with the previous follow up. Conclusions Patterns of mortality have not changed substantially since 1990. While positive associations with several cancers were observed, and are consistent with the published literature, interpretation is limited due to the small numbers of events for specific exposures. PMID:19001957

9 CFR 78.23 - Brucellosis exposed bison.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Brucellosis exposed bison. 78.23... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.23 Brucellosis exposed bison...

9 CFR 78.23 - Brucellosis exposed bison.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Brucellosis exposed bison. 78.23... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.23 Brucellosis exposed bison...

9 CFR 78.8 - Brucellosis exposed cattle.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Brucellosis exposed cattle. 78.8... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.8 Brucellosis exposed cattle...

9 CFR 78.23 - Brucellosis exposed bison.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Brucellosis exposed bison. 78.23... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.23 Brucellosis exposed bison...

9 CFR 78.8 - Brucellosis exposed cattle.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Brucellosis exposed cattle. 78.8... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.8 Brucellosis exposed cattle...

9 CFR 78.8 - Brucellosis exposed cattle.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Brucellosis exposed cattle. 78.8... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.8 Brucellosis exposed cattle...

9 CFR 78.23 - Brucellosis exposed bison.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Brucellosis exposed bison. 78.23... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.23 Brucellosis exposed bison...

Measuring helium bubble diameter distributions in tungsten with grazing incidence small angle x-ray scattering (GISAXS)

NASA Astrophysics Data System (ADS)

Thompson, M.; Kluth, P.; Doerner, R. P.; Kirby, N.; Riley, D.; Corr, C. S.

2016-02-01

Grazing incidence small angle x-ray scattering was performed on tungsten samples exposed to helium plasma in the MAGPIE and Pisces-A linear plasma devices to measure the size distributions of resulting helium nano-bubbles. Nano-bubbles were fitted assuming spheroidal particles and an exponential diameter distribution. These particles had mean diameters between 0.36 and 0.62 nm. Pisces-A exposed samples showed more complex patterns, which may suggest the formation of faceted nano-bubbles or nano-scale surface structures.

A Taxonomic Update of Small Mammal Plague Reservoirs in South America.

PubMed

Bonvicino, Cibele R; Oliveira, João A; Cordeiro-Estrela, Pedro; D'andrea, Paulo S; Almeida, Alzira M P

2015-10-01

Plague is a disease of epidemic potential that may emerge with discontinuous outbreaks. In South America, 50 wild rodent species have been identified as plague reservoirs, in addition to one lagomorph and two marsupials. To review the nomenclature of plague reservoirs, we examined specimens collected in plague foci, carried out new surveys in Brazilian plague regions, and re-evaluated the nomenclature of South American reservoirs on the basis of the current literature. Five of the 15 species involved with plague in Argentina, three of 10 species involved with plague in Bolivia, three of the seven species involved with plague in Peru, five of the nine species involved with plague in Ecuador, and six of the nine species involved with plague in Brazil have undergone taxonomic changes. In the last 20 years, plague cases were recorded in Bolivia, Brazil, Ecuador, and Peru. These four countries have a high rodent species richness in plague foci, a fact that may be decisive for the maintenance of plague in the wild.

[Biochemical evaluation on rural workers exposed to pesticides].

PubMed

Simoniello, María Fernanda; Kleinsorge, Elisa C; Carballo, Marta A

2010-01-01

Pesticides are used in agriculture to protect crops but may represent a potential risk to farmers and the environment. The aim of this work was to evaluate horticultural workers exposed to pesticide, categorized by: direct exposure (n = 45), indirect exposure (n = 50) and controls (n = 50) using exposure and effect biomarkers: cholinesterase (ChE), acetylcholinesterase (AChE), catalase (CAT), lipid peroxidation (TBARS), Damage Index Comet Assay (IDEC) and Damage Index Repair Assay (IDER). Our results show: a) an AChE inhibition in directly and indirectly exposed population (p < 0.001), b) significant increase in the levels of TBARS in direct exposure (p < 0.001), c) the CAT reduction was significant (p < 0.01), d) a significant increase in IDEC and IDER in both exposed groups (p < 0.001). Our results evidence variations in oxidative balance and DNA damage in exposed workers. These findings represent a contribution to the sub-clinical evaluation of subjects exposed to agrochemicals in our country.

The Effects of Wildfire on Mortality and Resources for an Arboreal Marsupial: Resilience to Fire Events but Susceptibility to Fire Regime Change

PubMed Central

Banks, Sam C.; Knight, Emma J.; McBurney, Lachlan; Blair, David; Lindenmayer, David B.

2011-01-01

Background Big environmental disturbances have big ecological effects, yet these are not always what we might expect. Understanding the proximate effects of major disturbances, such as severe wildfires, on individuals, populations and habitats will be essential for understanding how predicted future increases in the frequency of such disturbances will affect ecosystems. However, researchers rarely have access to data from immediately before and after such events. Here we report on the effects of a severe and extensive forest wildfire on mortality, reproductive output and availability of key shelter resources for an arboreal marsupial. We also investigated the behavioural response of individuals to changed shelter resource availability in the post-fire environment. Methodology/Principal Findings We fitted proximity-logging radiotransmitters to mountain brushtail possums (Trichosurus cunninghami) before, during and after the 2009 wildfires in Victoria, Australia. Surprisingly, we detected no mortality associated with the fire, and despite a significant post-fire decrease in the proportion of females carrying pouch young in the burnt area, there was no short-term post-fire population decline. The major consequence of this fire for mountain brushtail possums was the loss of over 80% of hollow-bearing trees. The types of trees preferred as shelter sites (highly decayed dead standing trees) were those most likely to collapse after fire. Individuals adapted to resource decline by being more flexible in resource selection after the fire, but not by increased resource sharing. Conclusions/Significance Despite short-term demographic resilience and behavioural adaptation following this fire, the major loss of decayed hollow trees suggests the increased frequency of stand-replacing wildfires predicted under climate change will pose major challenges for shelter resource availability for hollow-dependent fauna. Hollow-bearing trees are typically biological legacies of previous

Modified natural clinoptilolite detoxifies small mammal's organism loaded with lead II: genetic, cell, and physiological effects.

PubMed

Topashka-Ancheva, Margarita; Beltcheva, Michaela; Metcheva, Roumiana; Rojas, J Antonio Heredia; Rodriguez-De la Fuente, Abraham O; Gerasimova, Tsvetelina; Rodríguez-Flores, Laura E; Teodorova, Svetla E

2012-06-01

The detoxification capacity of the clinoptilolite modification KLS-10-MA used as food additive in small mammals, chronically lead-exposed, was proven for the first time. The modified clinoptilolite was prepared based on natural Bulgarian clinoptilolite deposits. As a powder, it was mechanically mixed at 12.5% concentration with the conventional forage for small rodents. Lead in the form of aqueous solution of Pb(NO(3))(2) was diluted in the drinking water. In the ecotoxicological experiment covering 90 days, imprinting control region laboratory mice were used. They were allocated into four groups: group 1, (control): animals fed with conventional food for small rodents and water; group 2: animals fed with conventional food + clinosorbent KLS-10-MA and water; group 3: animals fed with conventional food and water + Pb(NO(3))(2); and group 4: animals fed with conventional food + KLS-10-MA and water + Pb(NO(3))(2). A group of non-exposed healthy animals was fed with conventional forage mixed with KLS-10-MA to prove eventual toxicity of the sorbent and influence on growth performance. The changes in the chromosome structure, mitotic index, erythrocyte form, erythropoiesis, and body weight gain were recorded. On day 90, the following relations were established: Pb-exposed and clinoptilolite-supplemented mice exhibited 2.3-fold lower chromosome aberrations frequency, 2.5-fold higher mitotic index, and 1.5-fold higher percentage normal erythrocytes 1.3-fold higher body weight compared to Pb-exposed and unsupplemented animals. The obtained data showed that the sorbent is practically non-toxic. The results of the present study encourage a further elaboration of a reliable drug based on the tested substance in the cases of chronic lead intoxication.

How much more exposed are the poor to natural disasters? Global and regional measurement.

PubMed

Kim, Namsuk

2012-04-01

This paper proposes a simple indicator to measure the exposure to natural disasters for the poor and non-poor population, in order to assess the global and regional trend of natural hazard and poverty. Globally, poor people are two times more exposed to natural disasters than the non-poor in the twenty-first century. The time trend varies across regions, with poor people in East Asia and Pacific being most exposed to natural disasters, followed by those in South Asia and Sub-Saharan Africa. The change of exposure measure over time is decomposed into two factors: a pure exposure change, which could be fuelled by climate change; and a concentration component. The result shows that the total net increase of exposure between the 1970s and the 2000s is driven significantly by the increased concentration of the poor (26 per cent) in disaster-prone areas, whereas the contribution of that factor remains very small for the non-poor (six per cent). © 2012 The Author(s). Disasters © Overseas Development Institute, 2012.

Prolactin levels in manganese-exposed male welders.

PubMed

Tutkun, Engin; Abuşoğlu, Sedat; Yılmaz, Hinç; Gündüzöz, Meşide; Gıynas, Nilgün; Bal, Ceylan Demir; Ünlü, Ali

2014-12-01

Early studies on manganese (Mn) exposure have demonstrated that this transition metal affects dopamine neurotransmission. Dopamine serves as a tonic inhibitor of prolactin release in the anterior hypophysis. Our aim was to determine the relation between serum prolactin levels and manganese-exposure. Whole blood was collected from 95 non-exposed control subjects and 179 manganese-exposed male welders. Whole blood manganese was analyzed by Inductively Coupled Plasma--Mass Spectrometer on Agilent 7700 (Agilent Technologies, USA). Serum prolactin levels (PRL), aspartate transaminase (AST), alanine transaminase (ALT), urea, creatinine, soduim (Na), potassium (K) were analyzed by immunological and spectrophotometric methods on Roche E170 Modular System (Roche Diagnostics, Mannheim, Germany). The mean ages for control and manganese-exposed group were 40.5 ± 7.8 and 39.5 ± 8.7, respectively (p = 0.258). The mean working period (years) for control and manganese-exposed group were 17.4 ± 9.8 and 18.2 ± 7.7 years, respectively (p = 0.581). Serum AST and potassium levels were significantly higher in control group than manganese-exposed group (p = 0.002 and p = 0.048, respectively) and body-mass index (BMI) was significantly lower in control group than manganese-exposed group (p = 0.033). There was a significantly positive correlation between whole blood manganese levels and serum prolactin (r = 0.860, p < 0.001). Serum ALT levels were positively correlated with serum AST, urea and sodium (r = 0.315, p < 0.001; r = 0.121, p = 0.046; r = 0.130, p = 0.031). Serum prolactin level is a diagnostic marker for determining the effect of manganese-exposure.

Surface contamination on LDEF exposed materials

NASA Technical Reports Server (NTRS)

Hemminger, Carol S.

1992-01-01

X-ray photoelectron spectroscopy (XPS) has been used to study the surface composition and chemistry of Long Duration Exposure Facility (LDEF) exposed materials including silvered Teflon (Ag/FEP), Kapton, S13GLO paint, quartz crystal monitors (QCM's), carbon fiber/organic matrix composites, and carbon fiber/Al Alloy composites. In each set of samples, silicones were the major contributors to the molecular film accumulated on the LDEF exposed surfaces. All surfaces analyzed have been contaminated with Si, O, and C; most have low levels (less than 1 atom percent) of N, S, and F. Occasionally observed contaminants included Cl, Na, K, P, and various metals. Orange/brown discoloration observed near vent slots in some Ag/FEP blankets were higher in carbon, sulfur, and nitrogen relative to other contamination types. The source of contamination has not been identified, but amine/amide functionalities were detected. It is probable that this same source of contamination account for the low levels of sulfur and nitrogen observed on most LDEF exposed surfaces. XPS, which probes 50 to 100 A in depth, detected the major sample components underneath the contaminant film in every analysis. This probably indicates that the contaminant overlayer is patchy, with significant areas covered by less that 100 A of molecular film. Energy dispersive x-ray spectroscopy (EDS) of LDEF exposed surfaces during secondary electron microscopy (SEM) of the samples confirmed contamination of the surfaces with Si and O. In general, particulates were not observed to develop from the contaminant overlayer on the exposed LDEF material surfaces. However, many SiO2 submicron particles were seen on a masked edge of an Ag/FEP blanket. In some cases such as the carbon fiber/organic matrix composites, interpretation of the contamination data was hindered by the lack of good laboratory controls. Examination of laboratory controls for the carbon fiber/Al alloy composites showed that preflight contamination was

Vitamin D production after UVB exposure - a comparison of exposed skin regions.

PubMed

Osmancevic, Amra; Sandström, Katarina; Gillstedt, Martin; Landin-Wilhelmsen, Kerstin; Larkö, Olle; Wennberg Larkö, Ann-Marie; F Holick, Michael; Krogstad, Anne-Lene

2015-02-01

Cholecalciferol is an essential steroid produced in the skin by solar ultraviolet B radiation (UVB 290-315nm). Skin production of cholecalciferol depends on factors affecting UVB flux, age and exposed skin area. Serum cholecalciferol and 25-hydroxyvitamin D3 [25(OH)D3] concentrations were measured after UVB irradiation of 3 different skin areas to compare the skin capacity to produce vitamin D in different anatomic sites in the same individuals. Ten voluntary Caucasians (skin photo type II & III, aged 48±12years (±SD)) were exposed to broadband UVB (280-320nm) between February and April. Hands and face, upper body and whole body were exposed to a suberythemic dose of UVB (median 101mJ/cm(2) (min 66, max 143)) (for 3 subsequent days 24h apart with a wash out period of about 3weeks (median 18days (min 11, max 25)) between the exposures of respective area. Serum concentrations of cholecalciferol and 25(OH)D3, were measured immediately before the first and 24h after the last dose of radiation. There was a significantly higher increase in serum cholecalciferol after UVB exposure of the two larger skin areas compared to face and hands, but no difference in increase was found between upper body and whole body exposures. Exposure of a larger skin area was superior to small areas and gave greater increase in both serum cholecalciferol and serum 25(OH)D3 concentrations. However, exposure of face and hands, i.e. only 5% of the body surface area, was capable of increasing serum concentrations of 25(OH)D3. Copyright © 2015 Elsevier B.V. All rights reserved.

[A survey of occupational health among polyether-exposed workers].

PubMed

Fu, Xu-ying; Yu, Bin; Zhang, Chun-ping; Zheng, Guan-hua; Bai, Lan; Zhang, Pan-pan

2013-06-01

To investigate the occupational health of the workers simultaneously exposed to acrylonitrile, epoxyethane, epoxypropane, and styrene. A questionnaire survey was conducted in 70 front-line workers simultaneously exposed to acrylonitrile, epoxyethane, epoxypropane, and styrene (exposure group) and 50 managers (control group) in a polyether manufacturer; in addition, air monitoring at workplace and occupational health examination were also performed. The obtained data were analyzed. The female workers in exposure group and the spouses of male workers in exposure group had significantly higher spontaneous abortion rates than their counterparts in control group (P < 0.01). The exposure group had a significantly higher abnormal rate of blood urea nitrogen than the control group (P < 0.01). The workers with different polyether-exposed working years had significantly higher mean levels of DNA damage than the control group (P < 0.01); the workers with not less than 5 and less than 20 polyether-exposed working years and those with not less than 20 polyether-exposed working years had significantly higher mean micronucleus rates than the control group (P < 0.01); there were no significant differences in overall chromosome aberration rate and mean level of DNA damage between each two groups of workers with different polyether-exposed working years (P > 0.05); the workers with not less than 5 and less than 20 polyether-exposed working years and workers with not less than 20 polyether-exposed working years had significantly higher mean micronucleus rates than those with less than 5 polyether-exposed working years (P < 0.01). Simultaneous exposure to acrylonitrile, epoxyethane, epoxypropane, and styrene causes occupational hazards among the workers in polyether manufacturer.

Demonstration of global supply chains with intermodal transportation and decision support for small and medium business.

DOT National Transportation Integrated Search

2009-08-14

The globalization has exposed all companies, large or small, to global competition : and cooperation. The US furniture industry is not an exception in this process. Table 1 : provides an overall picture of the evolvement of the US residential furnitu...

Neurobehavioral Syndromes in Cocaine-Exposed Newborn Infants.

ERIC Educational Resources Information Center

Lester, Barry M.; And Others

1991-01-01

The effects of fetal cocaine exposure on newborn cry characteristics were studied in 80 cocaine-exposed and 80 control infants. Findings were consistent with the notion that two neurobehavioral syndromes, excitable and depressed, can be described in cocaine-exposed infants and that these two syndromes are a result of direct neurotoxic effects and…

Silent Victims: Children Exposed to Family Violence

ERIC Educational Resources Information Center

Kolar, Kathryn R.; Davey, Debrynda

2007-01-01

Annually an estimated 3 million or more children are exposed to acts of domestic violence between adults in their homes. These children are at risk for abuse themselves as well as other immediate and long-term problems, especially if they have been exposed to repeated episodes of domestic violence. Multiple behavioral manifestations, including…

Genetic damage in human cells exposed to non-ionizing radiofrequency fields: a meta-analysis of the data from 88 publications (1990-2011).

PubMed

Vijayalaxmi; Prihoda, Thomas J

2012-12-12

Based on the 'limited' evidence suggesting an association between exposure to radiofrequency fields (RF) emitted from mobile phones and two types of brain cancer, glioma and acoustic neuroma, the International Agency for Research on Cancer has classified RF as 'possibly carcinogenic to humans' in group 2B. In view of this classification and the positive correlation between increased genetic damage and carcinogenesis, a meta-analysis was conducted to determine whether a significant increase in genetic damage in human cells exposed to RF provides a potential mechanism for its carcinogenic potential. The extent of genetic damage in human cells, assessed from various end-points, viz., single-/double-strand breaks in the DNA, incidence of chromosomal aberrations, micronuclei and sister chromatid exchanges, reported in a total of 88 peer-reviewed scientific publications during 1990-2011 was considered in the meta-analysis. Among the several variables in the experimental protocols used, the influence of five specific variables related to RF exposure characteristics was investigated: (i) frequency, (ii) specific absorption rate, (iii) exposure as continuous wave, pulsed wave and occupationally exposed/mobile phone users, (iv) duration of exposure, and (v) different cell types. The data indicated the following. (1) The magnitude of difference between RF-exposed and sham-/un-exposed controls was small with some exceptions. (2) In certain RF exposure conditions there was a statistically significant increase in genotoxicity assessed from some end-points: the effect was observed in studies with small sample size and was largely influenced by publication bias. Studies conducted within the generally recommended RF exposure guidelines showed a smaller effect. (3) The multiple regression analyses and heterogeneity goodness of fit data indicated that factors other than the above five variables as well as the quality of publications have contributed to the overall results. (4) More

Hyperventilation and blood acid-base balance in hypercapnia exposed red drum (Sciaenops ocellatus).

PubMed

Ern, Rasmus; Esbaugh, Andrew J

2016-05-01

Hyperventilation is a common response in fish exposed to elevated water CO2. It is believed to lessen the respiratory acidosis associated with hypercapnia by lowering arterial PCO2, but the contribution of hyperventilation to blood acid-base compensation has yet to be quantified. Hyperventilation may also increase the flux of irons across the gill epithelium and the cost of osmoregulation, owing to the osmo-respiratory compromise. Therefore, hypercapnia exposed fish may increase standard metabolic rate (SMR) leaving less energy for physiological functions such as foraging, migration, growth and reproduction. Here we show that gill ventilation, blood PCO2 and total blood [CO2] increased in red drum (Sciaenops ocellatus) exposed to 1000 and 5000 µatm water CO2, and that blood PCO2 and total blood [CO2] decrease in fish during hypoxia induced hyperventilation. Based on these results we estimate the ventilatory contributions to total acid-base compensation in 1000 and 5000 µatm water CO2. We find that S. ocellatus only utilize a portion of its ventilatory capacity to reduce the acid-base disturbance in 1000 µatm water CO2. SMR was unaffected by both salinity and hypercapnia exposure indicating that the cost of osmoregulation is small relative to SMR, and that the lack of increased ventilation in 1000 µatm water CO2 despite the capacity to do so is not due to an energetic tradeoff between acid-base balance and osmoregulation. Therefore, while ocean acidification may impact ventilatory parameters, there will be little impact on the overall energy budget of S. ocellatus.

Cardiovascular changes in workers exposed to fine particulate dust.

PubMed

Bortkiewicz, Alicja; Gadzicka, Elżbieta; Stroszejn-Mrowca, Grażyna; Szyjkowska, Agata; Szymczak, Wiesław; Koszada-Włodarczyk, Wiesława; Szadkowska-Stańczyk, Irena

2014-01-01

Epidemiological studies provide evidence that airborne particulate matter may contribute to the increased incidence and mortality rates due to pulmonary and cardiovascular diseases. Only some of them address the problem of occupational exposure to particulate air pollution. The aim of our study was to assess cardiovascular reaction and autonomic regulation in workers exposed to fine particles. All workers had medical examination, resting ECG with heart rate variability analysis (HRV), 24-h ECG, and ambulatory blood pressure monitoring (ABPM) performed. The subjects were 20 male workers (mean age: 32.14.0 year) of a ceramic ware factory exposed to the dust and 20 workers who were not exposed (mean age: 39.4±7.8 year). The period of employment under exposure amounted to 5.6±2.1 year. Dust exposure was measured using individual dosimeters. The geometric mean total dust concentration was 44±1.5 mg/m(3) and the FPD (fine particulate dust) concentration amounted to 11.5±1.6 mg/m(3). No abnormalities were noted in the resting ECG in both groups, in 24-h ECG 2 subjects, both from exposed and control groups, had ventricular heart rhythm and repolarization disturbances. Blood pressure in ABPM, both systolic as well as diastolic, was normal and did not differ between the groups. Resting heart rate in the exposed group was significantly lower (p = 0.038) than in the control group. In the exposed group STD R-R from short-term records was significantly higher (p = 0.01). Fast Fourier Transform (FFT) analysis showed that the low frequency power spectrum (LF) did not differ in the exposed and the control group, while high frequency (HF) was significantly higher in the exposed group. LF/HF ratio was significantly lower in the exposed in comparison with the control group. Although we did not reveal significant abnormalities in ECG as well as in ABPM in the exposed group, it seems that neurovegetative disturbances (parasympathetic predominance) may serve as an early indicator of

Neurocognitive Changes among Elderly Exposed to PCBs/PCDFs in Taiwan

PubMed Central

Lin, Kao-Chang; Guo, Nai-Wen; Tsai, Pei-Chien; Yang, Chiu-Yueh; Guo, YueLiang Leon

2008-01-01

Background In 1979 approximately 2,000 people were exposed to polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs) due to ingestion of contaminated cooking oil in Taiwan. Although a previous study has shown delayed developmental milestones and poorer neurocognitive functioning in children born to exposed mothers, it is unclear whether neurocognitive functioning was impaired in people who were directly exposed to the PCBs and PDCFs. Objective The objective of this study was to compare neurocognitive functioning in people exposed to PCBs and PCDFs with that of unexposed sex- and age-matched neighbors. Methods We conducted a retrospective cohort study among exposed and unexposed subjects ≥60 years of age using prospective outcome measurements. We evaluated neurocognitive tests including cognition, memory modalities, learning, motor and sensory function, mood, and daily activity. Results In total, 162 (59%) exposed and 151 (55%) reference subjects completed this study. In exposed men, all test results were similar to the reference group; however, exposed women had reduced functioning in attention and digit span (ADS), visual memory span (VMS), and verbal memory recalls (VMR), especially learning ability. We also found a borderline reduction in the Mini-Mental State Examination. The digit symbol, motor, sensory, depression (determined by the Geriatric Depression Scale-Short Form), and activity of daily life were not different between the exposed and reference groups. A significant dose–response relationship was found for VMR, ADS, and VMS. Conclusion Our study showed dose-dependent neurocognitive deficits in certain aspects of attention, visual memory, and learning ability in women previously exposed to PCBs and PCDFs, but not in exposed men. PMID:18288316

Modern mammal origins: evolutionary grades in the Early Cretaceous of North America.

PubMed

Jacobs, L L; Winkler, D A; Murry, P A

1989-07-01

Major groups of modern mammals have their origins in the Mesozoic Era, yet the mammalian fossil record is generally poor for that time interval. Fundamental morphological changes that led to modern mammals are often represented by small samples of isolated teeth. Fortunately, functional wear facets on teeth allow prediction of the morphology of occluding teeth that may be unrepresented by fossils. A major step in mammalian evolution occurred in the Early Cretaceous with the evolution of tribosphenic molars, which characterize marsupials and placentals, the two most abundant and diverse extant groups of mammals. A tooth from the Early Cretaceous (110 million years before present) of Texas tests previous predictions (based on lower molars) of the morphology of upper molars in early tribosphenic dentitions. The lingual cusp (protocone) is primitively without shear facets, as expected, but the cheek side of the tooth is derived (advanced) in having distinctive cusps along the margin. The tooth, although distressingly inadequate to define many features of the organism, demonstrates unexpected morphological diversity at a strategic stage of mammalian evolution and falsifies previous claims of the earliest occurrence of true marsupials.

Modern mammal origins: evolutionary grades in the Early Cretaceous of North America.

PubMed Central

Jacobs, L L; Winkler, D A; Murry, P A

1989-01-01

Major groups of modern mammals have their origins in the Mesozoic Era, yet the mammalian fossil record is generally poor for that time interval. Fundamental morphological changes that led to modern mammals are often represented by small samples of isolated teeth. Fortunately, functional wear facets on teeth allow prediction of the morphology of occluding teeth that may be unrepresented by fossils. A major step in mammalian evolution occurred in the Early Cretaceous with the evolution of tribosphenic molars, which characterize marsupials and placentals, the two most abundant and diverse extant groups of mammals. A tooth from the Early Cretaceous (110 million years before present) of Texas tests previous predictions (based on lower molars) of the morphology of upper molars in early tribosphenic dentitions. The lingual cusp (protocone) is primitively without shear facets, as expected, but the cheek side of the tooth is derived (advanced) in having distinctive cusps along the margin. The tooth, although distressingly inadequate to define many features of the organism, demonstrates unexpected morphological diversity at a strategic stage of mammalian evolution and falsifies previous claims of the earliest occurrence of true marsupials. Images PMID:2740336

Depressive and trauma symptoms in expectant, risk-exposed, mothers and fathers: Is mindfulness a buffer?

PubMed

Hicks, Laurel M; Dayton, Carolyn J; Victor, Bryan G

2018-05-31

Perinatal depression is reported in 15-20% of women (Marcus, 2009), 8-16% of men (Paulson and Bazemore, 2010) and low-SES, diverse populations are particularly at risk (Sareen, 2011). Trauma symptoms are commonly comorbid with depression, especially when individuals are exposed to risk factors such as community violence and poverty (Kastello et al., 2015; WenzGross et al., 2016). Parental mental illness places infants at risk for negative outcomes (Junge et al., 2016). Evidence supports that dispositional mindfulness is linked to mental health in many populations, however, a gap lies in the understanding of the relationship between mindfulness, trauma and depression in risk-exposed, pregnant populations, especially with fathers. We hypothesize that dispositional mindfulness is negatively associated with lower depression and trauma symptoms in pregnancy, in mothers and fathers. Dispositional mindfulness, depressive and trauma symptoms were examined in women and men, exposed to adversity who were expecting a baby (N = 102). Independent t-tests, and bivariate correlations examined the relationships between these variables. Hierarchical regression was utilized to understand how mindfulness and trauma symptoms may contribute to antenatal depression symptoms. Significant differences were observed with mindfulness and depressive symptoms, with no differences reported across gender. Mindfulness, depressive and trauma symptoms were associated in the expected directions. Total mindfulness, specifically being non-reactive to one's own thoughts and trauma symptoms predicted depressive symptoms. Limitations include small sample size, cross-sectional data and self-report measures. Mindfulness and trauma symptoms were found to be significant predictors of depressive symptoms in parents-to-be. Those with lower mindfulness exhibited higher levels of depression. These findings may be helpful in disseminated mindfulness-based interventions aimed at treating antenatal

Neurodevelopmental outcomes in HIV-exposed-uninfected children versus those not exposed to HIV.

PubMed

Kerr, Stephen J; Puthanakit, Thanyawee; Vibol, Ung; Aurpibul, Linda; Vonthanak, Sophan; Kosalaraksa, Pope; Kanjanavanit, Suparat; Hansudewechakul, Rawiwan; Wongsawat, Jurai; Luesomboon, Wicharn; Ratanadilok, Kattiya; Prasitsuebsai, Wasana; Pruksakaew, Kanchana; van der Lugt, Jasper; Paul, Robert; Ananworanich, Jintanat; Valcour, Victor

2014-01-01

Human immunodeficiency virus (HIV)-negative children born to HIV-infected mothers may exhibit differences in neurodevelopment (ND) compared to age- and gender-matched controls whose lives have not been affected by HIV. This could occur due to exposure to HIV and antiretroviral agents in utero and perinatally, or differences in the environment in which they grow up. This study assessed neurodevelopmental outcomes in HIV-exposed uninfected (HEU) and HIV-unexposed uninfected (HUU) children enrolled as controls in a multicenter ND study from Thailand and Cambodia. One hundred sixty HEU and 167 HUU children completed a neurodevelopmental assessment using the Beery Visual Motor Integration (VMI) test, Color Trails, Perdue Pegboard, and Child Behavior Checklist (CBCL). Thai children (n = 202) also completed the Wechsler Intelligence Scale (IQ) and Stanford-Binet II memory tests. In analyses adjusted for caregiver education, parent as caregiver, household income, age, and ethnicity, statistically significant lower scores were seen on verbal IQ (VIQ), full-scale IQ (FSIQ), and Binet Bead Memory among HEU compared to HUU. The mean (95% CI) differences were -6.13 (-10.3 to -1.96), p = 0.004; -4.57 (-8.80 to -0.35), p = 0.03; and -3.72 (-6.57 to -0.88), p = 0.01 for VIQ, FSIQ, and Binet Bead Memory, respectively. We observed no significant differences in performance IQ, other Binet memory domains, Color Trail, Perdue Pegboard, Beery VMI, or CBCL test scores. We conclude that HEU children evidence reductions in some neurodevelopmental outcomes compared to HUU; however, these differences are small and it remains unclear to what extent they have immediate and long-term clinical significance.

Measured Noise from Small Unmanned Aerial Vehicles

NASA Technical Reports Server (NTRS)

Cabell, Randolph; McSwain, Robert; Grosveld, Ferdinand

2016-01-01

Proposed uses of small unmanned aerial vehicles (UAVs), including home package delivery, have the potential to expose large portions of communities to a new noise source. This paper discusses results of flyover noise measurements of four small UAVs, including an internal combustion-powered model airplane and three battery-powered multicopters. Basic noise characteristics of these vehicles are discussed, including spectral properties and sound level metrics such as sound pressure level, effective perceived noise level, and sound exposure level. The size and aerodynamic characteristics of the multicopters in particular make their flight path susceptible to atmospheric disturbances such as wind gusts. These gusts, coupled with a flight control system that varies rotor speed to maintain vehicle stability, create an unsteady acoustic signature. The spectral variations resulting from this unsteadiness are explored, in both hover and flyover conditions for the multicopters. The time varying noise, which differs from the relatively steady noise generated by large transport aircraft, may complicate the prediction of human annoyance using conventional sound level metrics.

Small molecule inhibitors of anthrax edema factor.

PubMed

Jiao, Guan-Sheng; Kim, Seongjin; Moayeri, Mahtab; Thai, April; Cregar-Hernandez, Lynne; McKasson, Linda; O'Malley, Sean; Leppla, Stephen H; Johnson, Alan T

2018-01-15

Anthrax is a highly lethal disease caused by the Gram-(+) bacteria Bacillus anthracis. Edema toxin (ET) is a major contributor to the pathogenesis of disease in humans exposed to B. anthracis. ET is a bipartite toxin composed of two proteins secreted by the vegetative bacteria, edema factor (EF) and protective antigen (PA). Our work towards identifying a small molecule inhibitor of anthrax edema factor is the subject of this letter. First we demonstrate that the small molecule probe 5'-Fluorosulfonylbenzoyl 5'-adenosine (FSBA) reacts irreversibly with EF and blocks enzymatic activity. We then show that the adenosine portion of FSBA can be replaced to provide more drug-like molecules which are up to 1000-fold more potent against EF relative to FSBA, display low cross reactivity when tested against a panel of kinases, and are nanomolar inhibitors of EF in a cell-based assay of cAMP production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Survey on Urinary Levels of Aflatoxins in Professionally Exposed Workers

PubMed Central

Ferri, Fulvio; Brera, Carlo; De Santis, Barbara; Fedrizzi, Giorgio; Bacci, Tiziana; Bedogni, Lorena; Capanni, Sauro; Collini, Giorgia; Crespi, Enrica; Debegnach, Francesca; Ferdenzi, Patrizia; Gargano, Angelo; Gattei, Daniela; Luberto, Ferdinando; Magnani, Ines; Magnani, Massimo Giuseppe; Mancuso, Pamela; Menotta, Simonetta; Mozzanica, Stefania; Olmi, Milva; Ombrini, Giuseppe; Sala, Orietta; Soricelli, Sabina; Vicentini, Massimo; Giorgi Rossi, Paolo

2017-01-01

Feed mill workers may handle or process maize contaminated with aflatoxins (AFs). This condition may lead to an unacceptable intake of toxins deriving from occupational exposure. This study assessed the serological and urinary levels of AFs in workers exposed to potentially contaminated dusts in two mills. From March to April 2014, blood and urine samples were collected, on Monday and Friday morning of the same working week from 29 exposed workers and 30 non-exposed controls. AFs (M1, G2, G1, B1, B2) and aflatoxicol (AFOH) A were analyzed. Each subject filled in a questionnaire to evaluate potential food-borne exposures to mycotoxins. AFs contamination in environmental dust was measured in both plants. No serum sample was found to be positive. Seventy four percent of urine samples (73.7%) revealed AFM1 presence. AFM1 mean concentration was 0.035 and 0.027 ng/mL in exposed and non-exposed workers, respectively (p = 0.432); the concentration was slightly higher in Friday’s than in Monday’s samples, in exposed workers, 0.040 versus (vs.) 0.031 and non-exposed controls (0.030 vs. 0.024, p = 0.437). Environmental AFs contamination ranged from 7.2 to 125.4 µg/kg. The findings of this study reveal the presence of higher AFs concentration in exposed workers than in non-exposed controls, although these differences are to be considered consistent with random fluctuations. PMID:28338636

Pulmonary function and oxidative stress in workers exposed to styrene in plastic factory: occupational hazards in styrene-exposed plastic factory workers.

PubMed

Sati, Prakash Chandra; Khaliq, Farah; Vaney, Neelam; Ahmed, Tanzeel; Tripathi, Ashok K; Banerjee, Basu Dev

2011-11-01

Styrene is a volatile organic compound used in factories for synthesis of plastic products. The pneumotoxicity of styrene in experimental animals is known. The aim of the present study was to study the effect of styrene on lung function and oxidative stress in occupationally exposed workers in plastic factory. Thirty-four male workers, between 18 and 40 years of age, exposed to styrene for atleast 8 hours a day for more than a year were studied, while 30 age- and sex-matched healthy subjects not exposed to styrene served as controls. Assessment of lung functions showed a statistically significant reduction (p < 0.05) in most of the lung volumes, capacities (FVC, FEV(1), VC, ERV, IRV, and IC) and flow rates (PEFR, MEF(75%), and MVV) in the study group (workers) as compared to controls. Malondialdehyde (MDA) was observed to be significantly high (p < 0.05) while ferric-reducing ability of plasma (FRAP) was significantly low (p < 0.05) in styrene-exposed subjects. Reduced glutathione (GSH) level was significantly depleted in exposed subjects as compared to control group. The mean value of serum cytochrome c in styrene-exposed subjects was found to be 1.1 ng/ml (0.89-1.89) while in control its levels were under detection limit (0.05 ng/ml). It shows that styrene inhalation by workers leads to increased level of oxidative stress, which is supposed to be the cause of lung damage.

Ticks infesting amphibians and reptiles in Pernambuco, Northeastern Brazil.

PubMed

Dantas-Torres, Filipe; Oliveira-Filho, Edmilson F; Soares, Fábio Angelo M; Souza, Bruno O F; Valença, Raul Baltazar P; Sá, Fabrício B

2008-01-01

Ticks infesting amphibians and reptiles in the State of Pernambuco are reviewed, based on the current literature and new collections recently carried out by the authors. To date, three tick species have been found on amphibians and reptiles in Pernambuco. Amblyomma fuscum appears to be exclusively associated with Boa constrictor, its type host. Amblyomma rotundatum has a relatively low host-specificity, being found on toads, snakes, and iguana. Amblyomma dissimile has been found on a lizard and also small mammals (i.e., rodents and marsupials). New tick-host associations and locality records are given.

An Empirical Assessment and Comparison of Species-Based and Habitat-Based Surrogates: A Case Study of Forest Vertebrates and Large Old Trees

PubMed Central

Lindenmayer, David B.; Barton, Philip S.; Lane, Peter W.; Westgate, Martin J.; McBurney, Lachlan; Blair, David; Gibbons, Philip; Likens, Gene E.

2014-01-01

A holy grail of conservation is to find simple but reliable measures of environmental change to guide management. For example, particular species or particular habitat attributes are often used as proxies for the abundance or diversity of a subset of other taxa. However, the efficacy of such kinds of species-based surrogates and habitat-based surrogates is rarely assessed, nor are different kinds of surrogates compared in terms of their relative effectiveness. We use 30-year datasets on arboreal marsupials and vegetation structure to quantify the effectiveness of: (1) the abundance of a particular species of arboreal marsupial as a species-based surrogate for other arboreal marsupial taxa, (2) hollow-bearing tree abundance as a habitat-based surrogate for arboreal marsupial abundance, and (3) a combination of species- and habitat-based surrogates. We also quantify the robustness of species-based and habitat-based surrogates over time. We then use the same approach to model overall species richness of arboreal marsupials. We show that a species-based surrogate can appear to be a valid surrogate until a habitat-based surrogate is co-examined, after which the effectiveness of the former is lost. The addition of a species-based surrogate to a habitat-based surrogate made little difference in explaining arboreal marsupial abundance, but altered the co-occurrence relationship between species. Hence, there was limited value in simultaneously using a combination of kinds of surrogates. The habitat-based surrogate also generally performed significantly better and was easier and less costly to gather than the species-based surrogate. We found that over 30 years of study, the relationships which underpinned the habitat-based surrogate generally remained positive but variable over time. Our work highlights why it is important to compare the effectiveness of different broad classes of surrogates and identify situations when either species- or habitat-based surrogates are likely

Mortality of Munitions Workers Exposed to Dinitrotuluene

DTIC Science & Technology

1986-01-01

ACCESSION NO . 3. RECIPIENT’S CATALOG NUMBER 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED L MORTALITY OF MUNITIONS WORKERS EXPOSED...AD__ _ _ _ _ _ o MORTALITY OF MUNITIONS WORKERS tO EXPOSED TO DINITROTOLUENE Um FINAL REPORT Richard J. Levine, Dragana A. Andjelkovich, Sharon...Kersteter, Earl W. Arp, Jr., Sandor A. Balogh, Patricia B. Blunden, and Jonathan M. Stanley Chemical Industry Institute of Toxicology Research Triangle

Cells exposed to nanosecond electrical pulses exhibit biomarkers of mechanical stress

NASA Astrophysics Data System (ADS)

Roth, Caleb C.; Barnes, Ronald A.; Ibey, Bennett L.; Beier, Hope T.; Moen, Erick K.; Glickman, Randolph D.

2015-03-01

Exposure of cells to very short (<1 μs) electric pulses in the megavolt/meter range have been shown to cause disruption of the plasma membrane. This disruption is often characterized by the formation of numerous small pores (<2 nm in diameter) in the plasma membrane that last for several minutes, allowing the flow of ions into the cell. These small pores are called nanopores and the resulting damage to the plasma membrane is referred to as nanoporation. Nanosecond electrical pulse (nsEP) exposure can impart many different stressors on a cell, including electrical, electro-chemical, and mechanical stress. Thus, nsEP exposure is not a "clean" insult, making determination of the mechanism of nanoporation quite difficult. We hypothesize that nsEP exposure creates acoustic shock waves capable of causing nanoporation. Microarray analysis of primary adult human dermal fibroblasts (HDFa) exposed to nsEP, indicated several genes associated with mechanical stress were selectively upregulated 4 h post exposure. The idea that nanoporation is caused by external mechanical force from acoustic shock waves has, to our knowledge, not been investigated. This work will critically challenge the existing paradigm that nanoporation is caused solely by an electric-field driven event and could provide the basis for a plausible explanation for electroporation.

The Affect of the Space Environment on the Survival of Halorubrum Chaoviator and Synechococcus (Nageli): Data from the Space Experiment OSMO on EXPOSE-R

NASA Technical Reports Server (NTRS)

Mancinelli, R. L.

2014-01-01

We have shown using ESA's Biopan facility flown in Earth orbit that when exposed to the space environment for 2 weeks the survival rate of Synechococcus (Nageli), a halophilic cyanobacterium isolated from the evaporitic gypsum-halite crusts that form along the marine intertidal, and Halorubrum chaoviator a member of the Halobacteriaceae isolated from an evaporitic NaCl crystal obtained from a salt evaporation pond, were higher than all other test organisms except Bacillus spores. These results led to the EXPOSE-R mission to extend and refine these experiments as part of the experimental package for the external platform space exposure facility on the ISS. The experiment was flown in February 2009 and the organisms were exposed to low-Earth orbit for nearly 2 years. Samples were either exposed to solar ultraviolet (UV)-radiation (lambda is greater than 110 nm or lambda is greater than 200 nm, cosmic radiation (dosage range 225-320 mGy), or kept in darkness shielded from solar UV-radiation. Half of each of the UV-radiation exposed samples and dark samples were exposed to space vacuum and half kept at 105 pascals in argon. Duplicate samples were kept in the laboratory to serve as unexposed controls. Ground simulation control experiments were also performed. After retrieval, organism viability was tested using Molecular Probes Live-Dead Bac-Lite stain and by their reproduction capability. Samples kept in the dark, but exposed to space vacuum had a 90 +/- 5% survival rate compared to the ground controls. Samples exposed to full UV-radiation for over a year were bleached and although results from Molecular Probes Live-Dead stain suggested approximately 10% survival, the data indicate that no survival was detected using cell growth and division using the most probable number method. Those samples exposed to attenuated UV-radiation exhibited limited survival. Results from of this study are relevant to understanding adaptation and evolution of life, the future of life

Methane exchange at the peatland forest floor - automatic chamber system exposes the dynamics of small fluxes

NASA Astrophysics Data System (ADS)

Korkiakoski, Mika; Tuovinen, Juha-Pekka; Aurela, Mika; Koskinen, Markku; Minkkinen, Kari; Ojanen, Paavo; Penttilä, Timo; Rainne, Juuso; Laurila, Tuomas; Lohila, Annalea

2017-04-01

We measured methane (CH4) exchange rates with automatic chambers at the forest floor of a nutrient-rich drained peatland in 2011-2013. The fen, located in southern Finland, was drained for forestry in 1969 and the tree stand is now a mixture of Scots pine, Norway spruce, and pubescent birch. Our measurement system consisted of six transparent chambers and stainless steel frames, positioned on a number of different field and moss layer compositions. Gas concentrations were measured with an online cavity ring-down spectroscopy gas analyzer. Fluxes were calculated with both linear and exponential regression. The use of linear regression resulted in systematically smaller CH4 fluxes by 10-45 % as compared to exponential regression. However, the use of exponential regression with small fluxes ( < 2.5 µg CH4 m-2 h-1) typically resulted in anomalously large absolute fluxes and high hour-to-hour deviations. Therefore, we recommend that fluxes are initially calculated with linear regression to determine the threshold for low fluxes and that higher fluxes are then recalculated using exponential regression. The exponential flux was clearly affected by the length of the fitting period when this period was < 190 s, but stabilized with longer periods. Thus, we also recommend the use of a fitting period of several minutes to stabilize the results and decrease the flux detection limit. There were clear seasonal dynamics in the CH4 flux: the forest floor acted as a CH4 sink particularly from early summer until the end of the year, while in late winter the flux was very small and fluctuated around zero. However, the magnitude of fluxes was relatively small throughout the year, ranging mainly from -130 to +100 µg CH4 m-2 h-1. CH4 emission peaks were observed occasionally, mostly in summer during heavy rainfall events. Diurnal variation, showing a lower CH4 uptake rate during the daytime, was observed in all of the chambers, mainly in the summer and late spring, particularly

The Psychobiology of Children Exposed to Marital Violence

ERIC Educational Resources Information Center

Saltzman, Kasey M.; Holden, George W.; Holahan, Charles J.

2005-01-01

We examined the psychological and physiological functioning of a community sample of children exposed to marital violence, comparing them to a clinical comparison group without marital violence exposure. Results replicated past findings of elevated levels of trauma symptomatology in this population. Further, children exposed to marital violence…

Work ability in vibration-exposed workers.

PubMed

Gerhardsson, L; Hagberg, M

2014-12-01

Hand-arm vibration exposure may cause hand-arm vibration syndrome (HAVS) including sensorineural disturbances. To investigate which factors had the strongest impact on work ability in vibration-exposed workers. A cross-sectional study in which vibration-exposed workers referred to a department of occupational and environmental medicine were compared with a randomized sample of unexposed subjects from the general population of the city of Gothenburg. All participants underwent a structured interview, answered several questionnaires and had a physical examination including measurements of hand and finger muscle strength and vibrotactile and thermal perception thresholds. The vibration-exposed group (47 subjects) showed significantly reduced sensitivity to cold and warmth in digit 2 bilaterally (P < 0.01) and in digit 5 in the left hand (P < 0.05) and to warmth in digit 5 in the right hand (P < 0.01), compared with the 18 referents. Similarly, tactilometry showed significantly raised vibration perception thresholds among the workers (P < 0.05). A strong relationship was found for the following multiple regression model: estimated work ability = 11.4 - 0.1 × age - 2.3 × current stress level - 2.5 × current pain in hands/arms (multiple r = 0.68; P < 0.001). Vibration-exposed workers showed raised vibrotactile and thermal perception thresholds, compared with unexposed referents. Multiple regression analysis indicated that stress disorders and muscle pain in hands/arms must also be considered when evaluating work ability among subjects with HAVS. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine.

Morbidity in New Zealand pesticide producers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

PubMed

't Mannetje, Andrea; Eng, Amanda; Walls, Chris; Dryson, Evan; Douwes, Jeroen; Bertazzi, Pier; Ryder-Lewis, Simon; Scott, David; Brooks, Collin; McLean, Dave; Cheng, Soo; Pearce, Neil

2018-01-01

To conduct a cross-sectional morbidity survey among 245 former employees of a pesticide production plant exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in New Zealand. Demographic factors and health information were collected in face-to-face interviews. TCDD, lipids, thyroid hormones, glucose and immunoglobulin G (IgG) were determined in non-fasting blood. For 111 participants, a neurological examination was conducted. Associations between health outcomes and working in a TCDD exposed job (prevalence 49%) and serum TCDD concentration≥10pg/g lipid (18%) were assessed using logistic regression whilst controlling for age, gender, smoking, body mass index and ethnicity. Diabetes was more common in those who had worked in TCDD exposed jobs (OR 4.0, 95%CI 1.0-15.4) and in those with serum TCDD ≥10pg/g (OR 3.1, 95%CI 0.9-10.7). Non-fasting glucose levels >6.6mmol/l were more common in those with TCDD exposed jobs (OR 3.6, 95%CI 1.0-12.9), as were serum free thyroxine 4<12.8pmol/l (OR 4.5, 95%CI 1.4-14.4), triglycerides >1.7mmol/l (OR 2.5, 95%CI 1.1-5.7) and high density lipoprotein cholesterol (HDL) <1mmol/l (OR 4.0, 95%CI 1.2-13.2). IgG was negatively associated with TCDD (linear regression p=0.05). The neurological examination revealed a higher frequency of abnormal reflexes in those with serum TCDD ≥10pg/g (OR 4.8, 95%CI 1.1-21.0). In this occupationally exposed population, TCDD was associated with an increased risk of diabetes and a range of subclinical responses in multiple systems (peripheral nervous system, immune system, thyroid hormones and lipid metabolism), several decades after last exposure. These results need to be interpreted with caution due to the small study size and the cross-sectional nature of the study. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neurodevelopmental outcomes in HIV-exposed-uninfected children versus those not exposed to HIV

PubMed Central

Kerr, Stephen J.; Puthanakit, Thanyawee; Vibol, Ung; Aurpibul, Linda; Vonthanak, Sophan; Kosalaraksa, Pope; Kanjanavanit, Suparat; Hansudewechakul, Rawiwan; Wongsawat, Jurai; Luesomboon, Wicharn; Ratanadilok, Kattiya; Prasitsuebsai, Wasana; Pruksakaew, Kanchana; van der Lugt, Jasper; Paul, Robert; Ananworanich, Jintanat; Valcour, Victor

2014-01-01

Human immunodeficiency virus (HIV)-negative children born to HIV-infected mothers may exhibit differences in neurodevelopment (ND) compared to age- and gender-matched controls whose lives have not been affected by HIV. This could occur due to exposure to HIV and antiretroviral agents in utero and perinatally, or differences in the environment in which they grow up. This study assessed neurodevelopmental outcomes in HIV-exposed uninfected (HEU) and HIV-unexposed uninfected (HUU) children enrolled as controls in a multicenter ND study from Thailand and Cambodia. One hundred sixty HEU and 167 HUU children completed a neurodevelopmental assessment using the Beery Visual Motor Integration (VMI) test, Color Trails, Perdue Pegboard, and Child Behavior Checklist (CBCL). Thai children (n = 202) also completed the Wechsler Intelligence Scale (IQ) and Stanford-Binet II memory tests. In analyses adjusted for caregiver education, parent as caregiver, household income, age, and ethnicity, statistically significant lower scores were seen on verbal IQ (VIQ), full-scale IQ (FSIQ), and Binet Bead Memory among HEU compared to HUU. The mean (95% CI) differences were −6.13 (−10.3 to −1.96), p = 0.004; −4.57 (−8.80 to −0.35), p = 0.03; and −3.72 (−6.57 to −0.88), p = 0.01 for VIQ, FSIQ, and Binet Bead Memory, respectively. We observed no significant differences in performance IQ, other Binet memory domains, Color Trail, Perdue Pegboard, Beery VMI, or CBCL test scores. We conclude that HEU children evidence reductions in some neurodevelopmental outcomes compared to HUU; however, these differences are small and it remains unclear to what extent they have immediate and long-term clinical significance. PMID:24878112

9 CFR 73.8 - Cattle infected or exposed during transit.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cattle infected or exposed during... SCABIES IN CATTLE § 73.8 Cattle infected or exposed during transit. (a) Healthy cattle from unquarantined State exposed en route. Should healthy cattle in transit from a State not quarantined by the Secretary...

Letter-Sound Knowledge: Exploring Gender Differences in Children When They Start School Regarding Knowledge of Large Letters, Small Letters, Sound Large Letters, and Sound Small Letters

PubMed Central

Sigmundsson, Hermundur; Eriksen, Adrian D.; Ofteland, Greta Storm; Haga, Monika

2017-01-01

This study explored whether there is a gender difference in letter-sound knowledge when children start at school. 485 children aged 5–6 years completed assessment of letter-sound knowledge, i.e., large letters; sound of large letters; small letters; sound of small letters. The findings indicate a significant difference between girls and boys in all four factors tested in this study in favor of the girls. There are still no clear explanations to the basis of a presumed gender difference in letter-sound knowledge. That the findings have origin in neuro-biological factors cannot be excluded, however, the fact that girls probably have been exposed to more language experience/stimulation compared to boys, lends support to explanations derived from environmental aspects. PMID:28951726

Growth and certain chemical constituents of tobacco plants exposed to air ions

NASA Astrophysics Data System (ADS)

Barthakur, N. N.; Arnold, N. P.

1988-06-01

Controlled experiments were performed in Faraday cages on the effects of positive and negative air ions on flue-cured tobacco plants. Continuous exposures for 15 days to air ions showed no significant differences in any plant growth characteristic between the treated and control plants. Standard errors in the measurement of the growth parameters for ion exposed plants were, however, consistently higher than those of control plants. Spatial variation in concentration gradients of air ions produced by corona discharge might have contributed to masking of the relatively small effects of air ions on biological organisms observed in previous experiments in this laboratory. No significant difference was observed between the experimental and control plants in nicotine, total alkaloid, and reducing sugar contents. Total nitrogen content was slightly higher for treated than control plants.

Analysis of Helium Segregation on Surfaces of Plasma-Exposed Tungsten

NASA Astrophysics Data System (ADS)

Maroudas, Dimitrios; Hu, Lin; Hammond, Karl; Wirth, Brian

2015-11-01

We report a systematic theoretical and atomic-scale computational study of implanted helium segregation on surfaces of tungsten, which is considered as a plasma facing component in nuclear fusion reactors. We employ a hierarchy of atomic-scale simulations, including molecular statics to understand the origin of helium surface segregation, targeted molecular-dynamics (MD) simulations of near-surface cluster reactions, and large-scale MD simulations of implanted helium evolution in plasma-exposed tungsten. We find that small, mobile helium clusters (of 1-7 He atoms) in the near-surface region are attracted to the surface due to an elastic interaction force. This thermodynamic driving force induces drift fluxes of these mobile clusters toward the surface, facilitating helium segregation. Moreover, the clusters' drift toward the surface enables cluster reactions, most importantly trap mutation, at rates much higher than in the bulk material. This cluster dynamics has significant effects on the surface morphology, near-surface defect structures, and the amount of helium retained in the material upon plasma exposure.

Assessment of coarse and fine hand motor performance in asymptomatic subjects exposed to hand-arm vibration.

PubMed

Popević, Martin B; Janković, Srđan M; Borjanović, Srđan S; Jovičić, Slavica R; Tenjović, Lazar R; Milovanović, Aleksandar P S; Bulat, Petar

2014-03-01

A frequently encountered exposure profile for hand-arm vibration in contemporary occupational setting comprises workers with a long history of intermittent exposure but without detectable signs of hand-arm vibration syndrome (HAVS). Yet, most of the published studies deal with developed HAVS cases, rarely discussing the biological processes that may be involved in degradation of manual dexterity and grip strength when it can be most beneficial - during the asymptomatic stage. In the present paper, a group of 31 male asymptomatic vibration-exposed workers (according to the Stockholm Workshop Scale) were compared against 30 male controls. They were tested using dynamometry and dexterimetry (modelling coarse and fine manual performance respectively) and cold provocation was done to detect possible differences in manual performance drop on these tests. The results showed reduced manual dexterity but no significant degradation in hand grip strength in the exposed subjects. This suggests that intermittent exposure profile and small cumulative vibration dose could only lead to a measurable deficit in manual dexterity but not hand grip strength even at non-negligible A(8) levels and long term exposures.

The affect of the space environment on the survival of Halorubrum chaoviator and Synechococcus (Nägeli): data from the Space Experiment OSMO on EXPOSE-R

NASA Astrophysics Data System (ADS)

Mancinelli, R. L.

2015-01-01

We have shown using ESA's Biopan facility flown in Earth orbit that when exposed to the space environment for 2 weeks the survival rate of Synechococcus (Nägeli), a halophilic cyanobacterium isolated from the evaporitic gypsum-halite crusts that form along the marine intertidal, and Halorubrum chaoviator a member of the Halobacteriaceae isolated from an evaporitic NaCl crystal obtained from a salt evaporation pond, were higher than all other test organisms except Bacillus spores. These results led to the EXPOSE-R mission to extend and refine these experiments as part of the experimental package for the external platform space exposure facility on the ISS. The experiment was flown in February 2009 and the organisms were exposed to low-Earth orbit for nearly 2 years. Samples were either exposed to solar ultraviolet (UV)-radiation (λ > 110 nm or λ > 200 nm, cosmic radiation (dosage range 225-320 mGy), or kept in darkness shielded from solar UV-radiation. Half of each of the UV-radiation exposed samples and dark samples were exposed to space vacuum and half kept at 105 pascals in argon. Duplicate samples were kept in the laboratory to serve as unexposed controls. Ground simulation control experiments were also performed. After retrieval, organism viability was tested using Molecular Probes Live-Dead Bac-Lite stain and by their reproduction capability. Samples kept in the dark, but exposed to space vacuum had a 90 +/- 5% survival rate compared to the ground controls. Samples exposed to full UV-radiation for over a year were bleached and although results from Molecular Probes Live-Dead stain suggested ~10% survival, the data indicate that no survival was detected using cell growth and division using the most probable number method. Those samples exposed to attenuated UV-radiation exhibited limited survival. Results from of this study are relevant to understanding adaptation and evolution of life, the future of life beyond earth, the potential for interplanetary

Molecular-dynamics analysis of mobile helium cluster reactions near surfaces of plasma-exposed tungsten

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Lin; Maroudas, Dimitrios, E-mail: maroudas@ecs.umass.edu; Hammond, Karl D.

We report the results of a systematic atomic-scale analysis of the reactions of small mobile helium clusters (He{sub n}, 4 ≤ n ≤ 7) near low-Miller-index tungsten (W) surfaces, aiming at a fundamental understanding of the near-surface dynamics of helium-carrying species in plasma-exposed tungsten. These small mobile helium clusters are attracted to the surface and migrate to the surface by Fickian diffusion and drift due to the thermodynamic driving force for surface segregation. As the clusters migrate toward the surface, trap mutation (TM) and cluster dissociation reactions are activated at rates higher than in the bulk. TM produces W adatoms and immobile complexes ofmore » helium clusters surrounding W vacancies located within the lattice planes at a short distance from the surface. These reactions are identified and characterized in detail based on the analysis of a large number of molecular-dynamics trajectories for each such mobile cluster near W(100), W(110), and W(111) surfaces. TM is found to be the dominant cluster reaction for all cluster and surface combinations, except for the He{sub 4} and He{sub 5} clusters near W(100) where cluster partial dissociation following TM dominates. We find that there exists a critical cluster size, n = 4 near W(100) and W(111) and n = 5 near W(110), beyond which the formation of multiple W adatoms and vacancies in the TM reactions is observed. The identified cluster reactions are responsible for important structural, morphological, and compositional features in the plasma-exposed tungsten, including surface adatom populations, near-surface immobile helium-vacancy complexes, and retained helium content, which are expected to influence the amount of hydrogen re-cycling and tritium retention in fusion tokamaks.« less

Neurodevelopmental outcomes in infants exposed in utero to antipsychotics: a systematic review of published data.

PubMed

Gentile, Salvatore; Fusco, Maria Luigia

2017-06-01

The proportion of pregnancies exposed to either second-generation antipsychotics (SGAs) or first-generation antipsychotics (FGAs) varies between 0.3%-2% of all pregnancies, but, until now, little is known about the potential neurobehavioral teratogenicity of antipsychotics. Assessing this safety facet is the aim of this article. PubMed, Scopus, and Google Scholar were searched for eligible articles. PubMed (1954 to May 2016) was searched using several medical subject headings, variously combined. PubMed search results were also limited using the search filter for human studies published in English. Scopus and Google Scholar searches were filtered for article title (antipsychotics/neuroleptics, pregnancy). After excluding duplicates, 9,250 articles were identified and 29 met the following inclusion criteria: only articles that provided original/primary data on neurodevelopmental outcome in human offspring older than 4 months of age, independently of the study design, were selected for review. Indeed, some relevant neurodevelopmental milestones are achieved at this time. Length of study and neurodevelopmental assessment methodology did not influence the study selection. Unfortunately, published data on neurodevelopmental teratogenicity of SGAs mainly derive from case reports and small case-series studies. Even findings emerging from case-control and prospective/retrospective studies are of limited clinical relevance because of their small sample sizes. Limited data are also available on FGAs. Hence, we have to conclude that the long-term neurodevelopmental outcomes for children exposed in utero remain unclear. Low to very low quality evidence of retrieved data makes impossible to confirm or exclude potential long-lasting untoward effects on infant neurocognitive development associate with antenatal exposure to either SGAs or FGAs.

Noninvasive treatment choice for an aged down syndrome patient presenting a residual periapical cyst.

PubMed

Sperandio, Felipe Fornias; Carli, Marina Lara de; Guimaräes, Eduardo Pereira; Pereira, Alessandro Antônio Costa; Hanemann, Joäo Adolfo Costa

2014-03-01

This is the first report to illustrate the marsupialization as an effective treatment for a Down Syndrome (DS) patient presenting a residual periapical cyst. These cysts occur within the alveolar ridge, usually at the local site of a previously extracted tooth that did not received proper curettage; usually the surgical excision of a cyst and also the vigorous curettage of a socket is very simple, if not for the fact that mentally disabled patients require rapid and non-stressful procedures. The 54-year-old DS patient represented herein received a minimally invasive marsupialization under local anesthesia. Due to the large extent of the lesion, the acrylic resin drain was maintained for 30 days. Through the following period, a daily irrigation of the cystic cavity with saline solution was carried out to prevent a secondary infection within the cystic cavity. A follow-up of 16 months showed no signs of recurrence. Marsupialization of residual periapical cyst is completely effective and safe, even for a DS patient that is considered to be at an advanced age. Marsupialization poses as a minimally invasive choice for mentally disabled patients, even when presenting advanced ages; treatment success was stated by the easy clinical conduct, uneventful postoperative situation and the lack of recurrence along 16 months of follow-up.

The effects of inhaled corticosteroids on intrinsic responsiveness and histology of airways from infant monkeys exposed to house dust mite allergen and ozone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joad, Jesse P.; Kott, Kayleen S.; Bric, John M.

2008-01-15

Inhaled corticosteroids (ICS) are recommended to treat infants with asthma, some with intermittent asthma. We previously showed that exposing infant monkeys to allergen/ozone resulted in asthma-like characteristics of their airways. We evaluated the effects of ICS on histology and intrinsic responsiveness of allergen/ozone-exposed and normal infant primate airways. Infant monkeys were exposed by inhalation to (1) filtered air and saline, (2) house dust mite allergen (HDMA) + ozone and saline, (3) filtered air and ICS (budesonide) or (4) HDMA + ozone and ICS. Allergen/ozone exposures started at 1 month and ICS at 3 months of age. At 6 months ofmore » age, methacholine-induced changes in luminal area of airways in proximal and distal lung slices were determined using videomicrometry, followed by histology of the same slices. Proximal airway responsiveness was increased by allergen/ozone and by ICS. Eosinophil profiles were increased by allergen/ozone in both proximal and distal airways, an effect that was decreased by ICS in distal airways. In both allergen/ozone- and air-exposed monkeys, ICS increased the number of alveolar attachments in distal airways, decreased mucin in proximal airways and decreased epithelial volume in both airways. ICS increased smooth muscle in air-exposed animals while decreasing it in allergen/ozone-exposed animals in both airways. In proximal airways, there was a small but significant positive correlation between smooth muscle and airway responsiveness, as well as between alveolar attachments and responsiveness. ICS change morphology and function in normal airways as well as allergen/ozone-exposed airways, suggesting that they should be reserved for infants with active symptoms.« less

Pulmonary function and symptoms in workers exposed to wood dust.

PubMed Central

Shamssain, M H

1992-01-01

BACKGROUND: Exposure to wood dust can cause a variety of lung problems, including chronic airflow obstruction. METHODS: Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory ratio (FEV1/FVC x 100), forced expiratory flow (FEF), forced mid expiratory flow (FMF), peak expiratory flow (PEF), and respiratory symptoms (cough, phlegm, breathlessness, wheezing, and nasal symptoms) were recorded in 145 non-smoking workers (77 male, 68 female) exposed to wood dust in a furniture factory in Umtata, Republic of Transkei, and 152 non-smoking control subjects (77 male, 75 female) from a bottling factory with a clean environment. RESULTS: After adjustment for age and standing height the forced expiratory indices were significantly lower in the exposed male workers than in the control subjects. FEF and PEF in the exposed men were 81.3% and 89.4% of predicted values and were lower than other indices. FVC in exposed men showed a significant inverse correlation with exposure (expressed in number of years of employment). The FVC was reduced by 26 ml per year of employment. The proportion of men with an FEV1/FVC below 70 was higher in exposed workers than in control subjects and higher in the exposed workers with more years of employment. The exposed workers had more respiratory symptoms than the control subjects, the prevalence, especially of cough and nasal symptoms, increasing with the increase in the number of years of employment. CONCLUSION: Workers exposed to pine and fibre dust have more respiratory symptoms and a greater risk of airflow obstruction. PMID:1549828

Underground Martian Ice Deposit Exposed at Scarp

NASA Image and Video Library

2018-01-11

Click on the image for larger version A cross-section of a thick sheet of underground ice is exposed at the steep slope (or scarp) that appears bright blue in this enhanced-color view from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. The view covers an area about 550 yards (500 meters) wide. Figure 1 includes a 100-meter (109-yard) scale bar. North is toward the top. The upper third of the image shows level ground that is about 140 yards (130 meters) higher in elevation than the ground in the bottom third. In between, the scarp descends sharply, exposing about 260 vertical feet (80 vertical meters) of water ice. Color is exaggerated to make differences in surface materials easier to see. The presence of exposed water ice at this site was confirmed by observation with the same orbiter's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). In January 2018, in the journal Science, researchers reported finding and studying eight such ice-exposing scarps in the middle latitudes of Mars. The presence of vast underground ice deposits in Mars' middle latitudes was known previously. The report of unusual sites where they are exposed provides new information about their depth and layering. It also identifies potential water resources for future Mars missions and possibilities for studying Martian climate history by examining the ice layers holding a record of past climate cycles. The ice may have been deposited as snow when the tilt of Mars' rotation axis was greater than it is now. HiRISE observation ESP_022389_1230 was made on May 7, 2011, at 56.6 degrees south latitude, 114.1 degrees east longitude. https://photojournal.jpl.nasa.gov/catalog/PIA22077

Deuterium retention and surface modification of tungsten macrobrush samples exposed in FTU Tokamak

NASA Astrophysics Data System (ADS)

Maddaluno, G.; Giacomi, G.; Rufoloni, A.; Verdini, L.

2007-06-01

The effect of discrete structures such as macrobrush or castellated surfaces on power handling and deuterium retention of plasma facing components is to be assessed since such geometrical configurations are needed for increasing the lifetime of the armour to heat-sink joint. Four small macrobrush W and W + 1%La2O3 samples have been exposed in the Frascati Tokamak Upgrade (FTU) scrape-off layer up to the last closed flux surface by means of the Sample Introduction System. FTU is an all metal machine with no carbon source inside vacuum vessel; it exhibits ITER relevant energy and particle fluxes on the plasma facing components. Here, results on morphological surface changes (SEM), chemical composition (EDX) and deuterium retention (TDS) are reported.

Platypus TCRμ provides insight into the origins and evolution of a uniquely mammalian TCR locus1

PubMed Central

Wang, Xinxin; Parra, Zuly E.; Miller, Robert D.

2011-01-01

TCRμ is an unconventional TCR that was first discovered in marsupials and appears to be absent from placental mammals and non-mammals. Here we show that TCRμ is also present in the duckbill platypus, an egg-laying monotreme, consistent with TCRμ being ancient and present in the last common ancestor of all extant mammals. As in marsupials, platypus TCRμ is expressed in a form containing double V domains. These V domains more closely resemble antibody V than that of conventional TCR. Platypus TCRμ differs from its marsupial homologue by requiring two rounds of somatic DNA recombination to assemble both V exons and has a genomic organization resembling the likely ancestral form of the receptor genes. These results demonstrate that the ancestors of placental mammals would have had TCRμ but it has been lost from this lineage. PMID:21976776

Platypus TCRμ provides insight into the origins and evolution of a uniquely mammalian TCR locus.

PubMed

Wang, Xinxin; Parra, Zuly E; Miller, Robert D

2011-11-15

TCRμ is an unconventional TCR that was first discovered in marsupials and appears to be absent from placental mammals and nonmammals. In this study, we show that TCRμ is also present in the duckbill platypus, an egg-laying monotreme, consistent with TCRμ being ancient and present in the last common ancestor of all extant mammals. As in marsupials, platypus TCRμ is expressed in a form containing double V domains. These V domains more closely resemble Ab V than that of conventional TCR. Platypus TCRμ differs from its marsupial homolog by requiring two rounds of somatic DNA recombination to assemble both V exons and has a genomic organization resembling the likely ancestral form of the receptor genes. These results demonstrate that the ancestors of placental mammals would have had TCRμ but it has been lost from this lineage.

Animal Cruelty by Children Exposed to Domestic Violence

ERIC Educational Resources Information Center

Currie, Cheryl L.

2006-01-01

Objective: The first objective of this study was to determine if children exposed to domestic violence were significantly more likely to be cruel to animals than children not exposed to violence. The second was to determine if there were significant age and gender differences between children who were and were not cruel to animals. Method: A…

Immunological studies in cattle exposed to polybrominated biphenyls

PubMed Central

Kateley, John R.; Bazzell, S. J.

1978-01-01

The intactness of the immune system in cattle exposed to polybrominated biphenyls (PBBs) has been investigated by using several immunoassays. Eighty-seven animals have been studied, 35 control animals (not exposed to PBBs) and 52 animals exposed to PBBs (0.02–30 ppm/g fat equivalent). The immunoassays included a complete blood count, identification of peripheral blood T and B lymphocyte subpopulations, serum immunoglobulin levels (IgG, IgM, and IgA), the in vitro response to lymphocytes to phytolectins (PHA, Con A, PWM), the antibody response to Keyhole limpet hemocyanin (KLH), the cell-mediated response to PPD, and determination of autoantibodies and/or immunosuppressive serum factors. For control and PBB-exposed cattle, there was no statistical difference between the number of circulating erythrocytes or leukocytes, the hematocrit, or hemoglobin content; the percentage or number of T and B lymphocytes; the isotope incorporation index (DNA synthesis) of lymphocytes in response to mitogens; the concentrations of serum immunoglobulins IgG, IgM, or IgA; the mean peak titer to KLH; or in vivo or in vitro immune response to PPD. Additional evaluation of cattle with tissue levels of PBB greater than 3 ppm/g tissue for hematological and immunological parameters revealed no statistical difference from control animals. Other experiments were performed to evaluate serum from cattle exposed to PBBs for autoantibodies to smooth muscle, mitochondrial or nuclear antigens. No evidence for autoantibodies was observed. Further studies were done to examine the cytotoxic and/or immunosuppressive activity of sera from PBB-exposed animals. In these studies, the blastogenic response of lymphocytes from control cattle and humans were evaluated in the presence and absence of serum from animals exposed to PBBs (> 3 ppm/g tissue). No evidence for either a cytotoxic or an immunosuppressive influence of such sera was demonstrable. Our studies indicate that PBB, at the levels studied, does

Short-term social memory deficits in adult female mice exposed to tannery effluent and possible mechanism of action.

PubMed

Estrela, Fernanda Neves; Rabelo, Letícia Martins; Vaz, Boniek Gontijo; de Oliveira Costa, Denys Ribeiro; Pereira, Igor; de Lima Rodrigues, Aline Sueli; Malafaia, Guilherme

2017-10-01

The accumulated organic residues in tannery-plant courtyards are an eating attraction to small rodents; however, the contact of these animals with these residues may change their social behavior. Thus, the aim of the present study is to investigate whether the exposure to tannery effluent (TE) can damage the social recognition memory of female Swiss mice, as well as to assess whether vitamin C supplementation could provide information about how TE constituents can damage these animals' memory. We have observed that resident females exposed to TE (without vitamin supplementation) did not explore the anogenital region, their body or chased intruding females for shorter time or with lower frequency during the retest session of the social recognition test, fact that indicates social recognition memory deficit in these animals. Such finding is reinforced by the confirmation that there was no change in the animals' olfactory function during the buried food test, or locomotor changes in females exposed to the pollutant. Since no behavioral change was observed in the females exposed to TE and treated with vitamin C (before or after the exposure), it is possible saying that these social cognitive impairments seem to be directly related to the imbalance between the cellular production of reactive oxygen species and the counteracting antioxidant mechanisms (oxidative stress) in female mice exposed to the pollutant (without vitamin supplementation). Therefore, the present study evidences that the direct contact with tannery effluent, even for a short period-of-time, may cause short-term social memory deficits in adult female Swiss mice. Copyright © 2017 Elsevier Ltd. All rights reserved.

XPS study of the effect of hydrocarbon contamination on polytetrafluoroethylene (teflon) exposed to atomic oxygen

NASA Technical Reports Server (NTRS)

Golub, Morton A.; Wydeven, Theodore; Cormia, Robert D.

1991-01-01

The presence of hydrocarbon contamination on the surface of polytetrafluoroethylene (PTFE) markedly affects the oxygen uptake, and hence the wettability, of this polymer when exposed to an oxygen plasma. As revealed by X-ray photoelectron spectroscopy (XPS) analysis, the oxygen-to-carbon ratio (O/C) for such a polymer can increase sharply, and correspondingly the fluorine-to-carbon ratio (F/C) can decrease sharply, at very short exposure times; at longer times, however, such changes in the O/C and F/C ratios reverse direction, and these ratios then assume values similar to those of the unexposed PTFE. The greater the extent of hydrocarbon contamination in the PTFE, the larger are the amplitudes of the 'spikes' in the O/C- and F/C-exposure time plots. In contrast, a pristine PTFE experiences a very small, monotonic increase of surface oxidation or O/C ratio with time of exposure to oxygen atoms, while the F/C ratio is virtually unchanged from that of the unexposed polymer (2.0). Unless the presence of adventitious hydrocarbon is taken into account, anomalous surface properties relating to polymer adhesion may be improperly ascribed to PTFE exposed to an oxygen plasma.

Spectral Modeling of Ground Ices Exposed by Trenching at the Phoenix Mars Landing Site

NASA Astrophysics Data System (ADS)

Cull, S.; Arvidson, R. E.; Blaney, D.; Morris, R. V.

2008-12-01

The Phoenix Lander, which landed on the northern plains of Mars on 25 May 2008, used its Robotic Arm (RA) to dig six trenches during its nominal 90-sol mission: Dodo-Goldilocks, Snow White, Cupboard, Neverland, Burn Alive, and Stone Soup. During excavation of the first five of these, the RA encountered hard material interpreted to be the ice table, and the Stereo Surface Imager (SSI) imaged the exposed materials using 15 filters spanning a wavelength range from 445 to 1001 nm. Materials exposed in the Dodo- Goldilocks and Snow White trenches are spectroscopically dissimilar: Dodo-Goldilocks hard material is brighter relative to the surrounding soil, and has a distinct downturn around 800 nm resulting from a dusty ice with low soil-to-ice ratio. Snow White hard stuff varies in brightness and spectral shape depending on the phase angle, with low-phase angle images showing dark material and higher phase angles showing more soil-like material. The Snow White material does not have the strong 800-nm downturn seen in Dodo- Goldilocks, because the soil-to-ice ratio is high as inferred by the rapid development of a sublimation lag; however, the albedo variation with phase angle could be due to strong forward-scattering at low phase angles, consistent with icy material. A modified Hapke model is used to estimate the relative abundances of water ice and dust in the Dodo- Goldilocks and Snow White materials, with dehydrated palagonite as an analogue for dust . The ice exposed at Dodo-Goldilocks must be relatively dust-free, since only a small amount of dust is needed to obscure water ice absorptions. In our modeling, we find that as little as 5 wt% 20-um dust is enough to completely mask the 1001 nm absorption in 1-mm grain size water ice. Dodo-Goldilocks spectra can have up to a 20% drop in reflectance from 800 nm to 1001 nm, which is best-matched in our Hapke model by water ice with path lengths on the order of 2-3 mm. The Snow White dark materials typically have a small

Epidemiological study of respiratory disease in workers exposed to polyvinylchloride dust.

PubMed Central

Soutar, C A; Copland, L H; Thornley, P E; Hurley, J F; Ottery, J; Adams, W G; Bennett, B

1980-01-01

The respiratory health of workers exposed to polyvinylchloride (PVC) dust has been investigated in 818 men sampled from the work force of a factory manufacturing PVC. In a cross-sectional survey, the lung function and prevalences of respiratory symptoms and chest radiographic abnormalities were compared with estimates of individual PVC dust exposures based on detailed occupational histories and current measurements of respirable PVC dust. Complaints of slight exertional dyspnoea were associated with PVC dust exposure, though age and smoking effects were much stronger. The forced expired volume in one second (FEV1) and forced vital capacity (FVC) were inversely related to dust exposure after age, height, and smoking effects had been taken into account. This effect was seen principally in cigarette smokers, and there was suggestive evidence that PVC dust exposure and cigarette smoking interacted in the reduction of FEV1 and FVC. Gas transfer factor was not related to dust exposure. The chest radiographs were read according to the ILO U/C classification by three experienced readers. One reader recorded a low prevalence of small rounded opacities, and these were not related to age or dust exposure. Another reader recorded a higher prevalence of small rounded opacities category 0/1 or more, and these were related to age but not to dust exposure. The third reader recorded the highest prevalence of small rounded opacities (though none greater than category 1/1), and these were independently related both to age and to PVC dust exposure, indicating an effect of PVC dust on the appearance of the chest radiography. These appearances were so slight that only the higher sensitivity of this reader in the interpretation of profusion of small rounded opacities on the ILO U/C scale enabled detection of this effect of PVC dust. In conclusion, exposure to PVC dust is associated with some deterioration of lung function, slight abnormalities of the chest radiograph, and complaints of

LIFE experiment: isolation of cryptoendolithic organisms from Antarctic colonized sandstone exposed to space and simulated Mars conditions on the international space station.

PubMed

Scalzi, Giuliano; Selbmann, Laura; Zucconi, Laura; Rabbow, Elke; Horneck, Gerda; Albertano, Patrizia; Onofri, Silvano

2012-06-01

Desiccated Antarctic rocks colonized by cryptoendolithic communities were exposed on the International Space Station (ISS) to space and simulated Mars conditions (LiFE-Lichens and Fungi Experiment). After 1.5 years in space samples were retrieved, rehydrated and spread on different culture media. Colonies of a green alga and a pink-coloured fungus developed on Malt-Agar medium; they were isolated from a sample exposed to simulated Mars conditions beneath a 0.1 % T Suprasil neutral density filter and from a sample exposed to space vacuum without solar radiation exposure, respectively. None of the other flight samples showed any growth after incubation. The two organisms able to grow were identified at genus level by Small SubUnit (SSU) and Internal Transcribed Spacer (ITS) rDNA sequencing as Stichococcus sp. (green alga) and Acarospora sp. (lichenized fungal genus) respectively. The data in the present study provide experimental information on the possibility of eukaryotic life transfer from one planet to another by means of rocks and of survival in Mars environment.

LIFE Experiment: Isolation of Cryptoendolithic Organisms from Antarctic Colonized Sandstone Exposed to Space and Simulated Mars Conditions on the International Space Station

NASA Astrophysics Data System (ADS)

Scalzi, Giuliano; Selbmann, Laura; Zucconi, Laura; Rabbow, Elke; Horneck, Gerda; Albertano, Patrizia; Onofri, Silvano

2012-06-01

Desiccated Antarctic rocks colonized by cryptoendolithic communities were exposed on the International Space Station (ISS) to space and simulated Mars conditions (LiFE— Lichens and Fungi Experiment). After 1.5 years in space samples were retrieved, rehydrated and spread on different culture media. Colonies of a green alga and a pink-coloured fungus developed on Malt-Agar medium; they were isolated from a sample exposed to simulated Mars conditions beneath a 0.1 % T Suprasil neutral density filter and from a sample exposed to space vacuum without solar radiation exposure, respectively. None of the other flight samples showed any growth after incubation. The two organisms able to grow were identified at genus level by Small SubUnit (SSU) and Internal Transcribed Spacer (ITS) rDNA sequencing as Stichococcus sp. (green alga) and Acarospora sp. (lichenized fungal genus) respectively. The data in the present study provide experimental information on the possibility of eukaryotic life transfer from one planet to another by means of rocks and of survival in Mars environment.

Expose-R experiment on effects of open space condition on survivorship in dormant stages of aquatic invertebrates

NASA Astrophysics Data System (ADS)

Alekseev, Victor; Novikova, Nataliya; Levinskikh, Margarita; Sychev, Vladimir; Yusoff, Fatimah; Azuraidi, Osman

2012-07-01

Dormancy protects animals and plants in harsh environmental conditions from months up to hundred years. This phenomenon is perspective for space researches especially for interplanetary missions. Direct experiments in open space BYORYSK supported in principle the fact of survivorship of bacteria, fungi spores, seed of plants and crustacean dormant cysts. Even though the rate of survivorship in long-term treatments was low but good enough to conclude that biological invasion even to Mars is a real danger. As soon as the BYORYSK lunch was made of metal the possibility for resting stages to survive under UV treatment in vacuum without some protection was not clear. To test it an ESA and RSA equipment titled EXPOSE-R was applied. The EXPOSE-R facility was an external facility attached to the outside of the Zvezda Service Module in ISS in the end of November 2008. It had glace windows transparent for UV-radiation and possibility to measure temperature, space- and UV-radiation. Among a number of experiments requiring exposure to the open space environment it had a biological launch containing resting stages of terrestrial and aquatic organisms. These stages included dried ephippia of cladoceran Daphnia magna differentiated on size, dormant eggs of ostracode Eucypris ornate, cysts of fair-shrimp Streptocephalus torvicornis ( all from hemi desert Caspian area) and Artemis salina from salt lake Crimean populations. All dormant stages were kept in transparent to UV plastic bags placed in three layers. After about two years of exposing in open space dormant stages of 3 species A. salina, D. magna, S. torvicornis successfully survived at different scales but in second and third layers only . The highest level of survivorship was found in A. salina cysts. In preliminary land experiments that imitated land EXPOSE imitation of outside space station UV and vacuum conditions survivorship in resting eggs of D .magna, S. torvicornis and E. ornate was tested also. The total UV dose of

Maternal low intensity physical exercise prevents obesity in offspring rats exposed to early overnutrition.

PubMed

Ribeiro, Tatiane Aparecida; Tófolo, Laize Peron; Martins, Isabela Peixoto; Pavanello, Audrei; de Oliveira, Júlio Cezar; Prates, Kelly Valério; Miranda, Rosiane Aparecida; da Silva Franco, Claudinéia Conationi; Gomes, Rodrigo Mello; Francisco, Flávio Andrade; Alves, Vander Silva; de Almeida, Douglas Lopes; Moreira, Veridiana Mota; Palma-Rigo, Kesia; Vieira, Elaine; Fabricio, Gabriel Sergio; da Silva Rodrigues, Marcos Ricardo; Rinaldi, Wilson; Malta, Ananda; de Freitas Mathias, Paulo Cezar

2017-08-09

Low intensity exercise during pregnancy and lactation may create a protective effect against the development of obesity in offspring exposed to overnutrition in early life. To test these hypotheses, pregnant rats were randomly assigned into 2 groups: Sedentary and Exercised, low intensity, on a rodent treadmill at 30% VO 2Max /30-minute/session/3x/week throughout pregnancy and the lactation. Male offspring were raised in small litters (SL, 3 pups/dam) and normal litters (NL, 9 pups/dam) as models of early overnutrition and normal feed, respectively. Exercised mothers showed low mesenteric fat pad stores and fasting glucose and improved glucose-insulin tolerance, VO 2max during lactation and sympathetic activity. Moreover, the breast milk contained elevated levels of insulin. In addition, SL of sedentary mothers presented metabolic dysfunction and glucose and insulin intolerance and were hyperglycemic and hyperinsulinemic in adulthood. SL of exercised mothers showed lower fat tissue accretion and improvements in glucose tolerance, insulin sensitivity, insulinemia and glycemia. The results suggest that maternal exercise during the perinatal period can have a possible reprogramming effect to prevent metabolic dysfunction in adult rat offspring exposed to early overnutrition, which may be associated with the improvement in maternal health caused by exercise.

Hemoglobin adducts as biomarkers of 1,3-butadiene in occupationally low exposed Italian workers and a few diesel-exposed miners.

PubMed

Begemann, P; Upton, P B; Ranasinghe, A; Swenberg, J A; Soleo, L; Vimercati, L; Gelormini, A; Fustinoni, S; Zwirner-Baier, I; Neumann, H G

2001-06-01

Hemoglobin adducts were determined as biomarkers of 1,3-butadiene (BD) in 30 workers and 10 controls from an Italian BD plant and in 14 diesel-exposed miners. N-(2,3,4-trihydroxybutyl)valine (THBVal), an N-terminal valine globin adduct of reactive butadiene metabolites, was analyzed by gas chromatography/high resolution mass spectrometry after a modified Edman degradation and further acetylation. The BD exposure for the plant workers was 31 microg/m(3) (personal sampling). Whereas there was no detectable difference in hemoglobin adduct levels (range 17.7-61.4 pmol/g globin) between the total group of exposed and controls, slight but significant differences could be found between two subgroups of workers from different production units as well as one subgroup and controls (P<0.05), between smoking (n=13) and non-smoking exposed workers (n=17; P=0.066) as well as between smoking exposed workers and controls (P=0.055). Adduct levels of the miners (all non-smokers) were in the same range as those of the Italian BD-workers and controls. The internal exposure and strain measured by THBVal levels resulting from a very low occupational BD exposure was in the range of the contribution of moderate smoking.

Equilibrium disorders in workers exposed to mixed solvents.

PubMed

Giorgianni, Concetto; Tanzariello, Mariagiuseppina; De Pasquale, Domenico; Brecciaroli, Renato; Spatari, Giovanna

2018-02-06

Organic solvents cause diseases of the vestibular system. However, little is known regarding the correlation between vestibular damage and exposure to organic solvents below threshold limit values. The best measure by which to evaluate vestibular disorders is static and dynamic posturography. The aim of this study was to evaluate equilibrium disorders via static and dynamic posturography in workers without clear symptoms and exposed to low doses of mixed solvents. 200 subjects were selected. Using an Otometrics device (Madsen, Denmark), all subjects endured static and dynamic posturography testing with both eyes-open and eyes-closed conditions. Results were compared with a control group of unexposed individuals. Based on the obtained data, the following results can be drawn: (a) subjects exposed to mixtures of solvents show highly significant differences regarding all static and dynamic posturography parameters in comparison to the control group; (b) posturography testing has proven to be a valid means by which to detect subliminal equilibrium disorders in subjects exposed to solvents. We can confirm that refinery workers exposed to mixtures of solvents can present subliminal equilibrium disorders. Early diagnosis of the latter is made possible by static and dynamic posturography.

Endoscopically assisted enucleation of a large mandibular periapical cyst.

PubMed

Nestal Zibo, Heleia; Miller, Ene

2011-01-01

Enucleation of large cysts in the jaws is an invasive method that might be associated with complications. Marsupialization is a less invasive alternative method but it involves a prolonged and uncomfortable healing period. This study addresses a contemporaneous and less invasive surgical technique for treating larger mandibular cysts. MATERIALS AND METHODS. A 48-year-old woman presented with a large mandibular apical cyst involving the left parasymphysis, body, ramus and condylar neck, with involvement of the alveolar inferior nerve. The cystic lesion was enucleated using a 30° 4.0 mm endoscopic scope and endoscopic instruments through two small accesses: the ostectomy site of previously performed marsupialization and the alveolus of the involved third molar extracted of the time of the enucleation of the cyst. RESULTS. The endoscopic scope provided good visualization of the whole cystic cavity allowing the removal of any residual pathologic tissue and preservation of the integrity of the involved inferior alveolar nerve. The morbidity of the surgical procedure was extremely reduced. At a 6-month follow-up the patient did not present any symptom of inflammation and a panoramic X-ray showed good bone repair and remodelation. CONCLUSIONS. Endoscopically assisted enucleation proved to be effective method of treating a large mandibular cyst, providing total enucleation with a minimal invasive technique.

[Hepatotoxicity in healthy infants exposed to nevirapine during pregnancy].

PubMed

Iveli, Pablo; Noguera-Julian, Antoni; Soler-Palacín, Pere; Martín-Nalda, Andrea; Rovira-Girabal, Núria; Fortuny-Guasch, Clàudia; Figueras-Nadal, Concepció

2016-01-01

The use of nevirapine in HIV-infected pregnant women is discouraged due to its potential to cause hepatotoxicity. There is limited information available on the toxicity in non-HIV infected newborn exposed to this drug during pregnancy. The aim of the study is to determine the extent of hepatotoxicity in the newborn exposed to nevirapine and HIV during pregnancy. A cross-sectional, observational, multicenter study was conducted on a cohort of healthy infants born to HIV-infected mothers, in whom the first determination of alanine aminotransferase (ALT), before 6weeks of age, was collected. Patients were allocated to 2groups according to exposure to nevirapine during pregnancy. Hepatotoxicity was rated according to the AIDS Table for Grading the Severity of Adult and Pediatric Adverse Events (DAIDS). This study included 160newborns from 159pregnancies (88exposed to nevirapine-based regimens and 71 exposed to protease inhibitors-based therapies). No cases of hepatotoxicity were observed according to the DAIDS Table for Grading. Two cases of ALT above normal values (2.8%; 95%CI: 0.3-9.8%) were observed in patients not exposed to nevirapine, and one case (1.1%; 95%CI: 0.0-6.1%) in the group exposed to nevirapine (P=.585). The lack of differences between groups suggests that highly active antiretroviral treatment regimens including nevirapine administered during pregnancy do not involve a higher risk of liver disease compared to other treatment combinations. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

A small RNA activates CFA synthase by isoform-specific mRNA stabilization

PubMed Central

Fröhlich, Kathrin Sophie; Papenfort, Kai; Fekete, Agnes; Vogel, Jörg

2013-01-01

Small RNAs use a diversity of well-characterized mechanisms to repress mRNAs, but how they activate gene expression at the mRNA level remains not well understood. The predominant activation mechanism of Hfq-associated small RNAs has been translational control whereby base pairing with the target prevents the formation of an intrinsic inhibitory structure in the mRNA and promotes translation initiation. Here, we report a translation-independent mechanism whereby the small RNA RydC selectively activates the longer of two isoforms of cfa mRNA (encoding cyclopropane fatty acid synthase) in Salmonella enterica. Target activation is achieved through seed pairing of the pseudoknot-exposed, conserved 5′ end of RydC to an upstream region of the cfa mRNA. The seed pairing stabilizes the messenger, likely by interfering directly with RNase E-mediated decay in the 5′ untranslated region. Intriguingly, this mechanism is generic such that the activation is equally achieved by seed pairing of unrelated small RNAs, suggesting that this mechanism may be utilized in the design of RNA-controlled synthetic circuits. Physiologically, RydC is the first small RNA known to regulate membrane stability. PMID:24141880

A small RNA activates CFA synthase by isoform-specific mRNA stabilization.

PubMed

Fröhlich, Kathrin Sophie; Papenfort, Kai; Fekete, Agnes; Vogel, Jörg

2013-11-13

Small RNAs use a diversity of well-characterized mechanisms to repress mRNAs, but how they activate gene expression at the mRNA level remains not well understood. The predominant activation mechanism of Hfq-associated small RNAs has been translational control whereby base pairing with the target prevents the formation of an intrinsic inhibitory structure in the mRNA and promotes translation initiation. Here, we report a translation-independent mechanism whereby the small RNA RydC selectively activates the longer of two isoforms of cfa mRNA (encoding cyclopropane fatty acid synthase) in Salmonella enterica. Target activation is achieved through seed pairing of the pseudoknot-exposed, conserved 5' end of RydC to an upstream region of the cfa mRNA. The seed pairing stabilizes the messenger, likely by interfering directly with RNase E-mediated decay in the 5' untranslated region. Intriguingly, this mechanism is generic such that the activation is equally achieved by seed pairing of unrelated small RNAs, suggesting that this mechanism may be utilized in the design of RNA-controlled synthetic circuits. Physiologically, RydC is the first small RNA known to regulate membrane stability.

Difficulties of attribution of effect in workers exposed to fiberglass and asbestos.

PubMed

Kilburn, K H; Warshaw, R H

1991-01-01

Man-made mineral fibers have many properties of asbestos that raise concern about their safety. We studied 175 fiberglass production workers, using chest radiographs, measurement of total lung capacity, chest examinations, and occupational and medical histories. Pulmonary volumes and flows were calculated as percent of predicted, adjusted for height, age, ethnicity, and cigarette smoking. Thirty-one men with radiographically evident small irregular opacities of profusion of 1/0 or greater and/or pleural abnormalities were observed. Eight of 38 men with such changes said they had been exposed only to fiberglass; the other 23 with radiologically detectable pleural and/or pulmonary changes were among the 137 whose histories indicated that they had been exposed to asbestos and to fiberglass. Pulmonary function measurements as group means were reduced in the 175: FVC was 94.8% predicted, FEV1 was 91.3% predicted, FEF25-75 was 80.7% predicted, FEF75-85 was 73.1% predicted and FEV1/FVC was 0.73. Total lung capacity (TLC) was elevated to 114.2% predicted (mean) and RV/TLC (mean 0.46) was also elevated. Although only 78% of fiberglass production workers gave histories of asbestos exposure, all had shared the air in a manufacturing plant where ovens insulated with asbestos were continuously cleaned, repaired, dismantled, and rebuilt. It appears that attribution of the effects of their exposure to fiberglass could not be estimated independently of the effects of asbestos exposure.

Formation of the hindgut cuticular lining during embryonic development of Porcellio scaber (Crustacea, Isopoda)

PubMed Central

Mrak, Polona; Bogataj, Urban; Štrus, Jasna; Žnidaršič, Nada

2015-01-01

Abstract The hindgut and foregut in terrestrial isopod crustaceans are ectodermal parts of the digestive system and are lined by cuticle, an apical extracellular matrix secreted by epithelial cells. Morphogenesis of the digestive system was reported in previous studies, but differentiation of the gut cuticle was not followed in detail. This study is focused on ultrastructural analyses of hindgut apical matrices and cuticle in selected intramarsupial developmental stages of the terrestrial isopod Porcellio scaber in comparison to adult animals to obtain data on the hindgut cuticular lining differentiation. Our results show that in late embryos of stages 16 and 18 the apical matrix in the hindgut consists of loose material overlaid by a thin intensely ruffled electron dense lamina facing the lumen. The ultrastructural resemblance to the embryonic epidermal matrices described in several arthropods suggests a common principle in chitinous matrix differentiation. The hindgut matrix in the prehatching embryo of stage 19 shows characteristics of the hindgut cuticle, specifically alignment to the apical epithelial surface and a prominent electron dense layer of epicuticle. In the preceding embryonic stage – stage 18 – an electron dense lamina, closely apposed to the apical cell membrane, is evident and is considered as the first epicuticle formation. In marsupial mancae the advanced features of the hindgut cuticle and epithelium are evident: a more prominent epicuticular layer, formation of cuticular spines and an extensive apical labyrinth. In comparison to the hindgut cuticle of adults, the hindgut cuticle of marsupial manca and in particular the electron dense epicuticular layer are much thinner and the difference between cuticle architecture in the anterior chamber and in the papillate region is not yet distinguishable. Differences from the hindgut cuticle in adults imply not fully developed structure and function of the hindgut cuticle in marsupial manca, possibly

High Expression of Antiviral and Vitamin D Pathway Genes Are a Natural Characteristic of a Small Cohort of HIV-1-Exposed Seronegative Individuals.

PubMed

Aguilar-Jimenez, Wbeimar; Saulle, Irma; Trabattoni, Daria; Vichi, Francesca; Lo Caputo, Sergio; Mazzotta, Francesco; Rugeles, Maria T; Clerici, Mario; Biasin, Mara

2017-01-01

Natural resistance to HIV-1 infection is influenced by genetics, viral-exposure, and endogenous immunomodulators such as vitamin D (VitD), being a multifactorial phenomenon that characterizes HIV-1-exposed seronegative individuals (HESNs). We compared mRNA expression of 10 antivirals, 5 immunoregulators, and 3 VitD pathway genes by qRT-PCR in cells of a small cohort of 11 HESNs, 16 healthy-controls (HCs), and 11 seropositives (SPs) at baseline, in response to calcidiol (VitD precursor) and/or aldithriol-2-(AT2)-inactivated HIV-1. In addition, the expression of TIM-3 on T and NK cells of six HCs after calcidiol and calcitriol (active VitD) treatments was evaluated by flow cytometry. Calcidiol increased the mRNA expression of HAVCR2 (TIM-3; Th1-cells inhibitor) in HCs and HESNs. AT2-HIV-1 increased the mRNA expression of the activating VitD enzyme CYP27B1 , of the endogenous antiviral proteins MX2, TRIM22, APOBEC3G , and of immunoregulators ERAP2 and HAVCR2 , but reduced the mRNA expression of VitD receptor ( VDR ) and antiviral peptides PI3 and CAMP in all groups. Remarkably, higher mRNA levels of VDR, CYP27B1, PI3, CAMP, SLPI , and of ERAP2 were found in HESNs compared to HCs either at baseline or after stimuli. Furthermore, calcitriol increases the percentage of CD4+ T cells expressing TIM-3 protein compared to EtOH controls. These results suggest that high mRNA expression of antiviral and VitD pathway genes could be genetically determined in HESNs more than viral-induced at least in peripheral blood mononuclear cells. Moreover, the virus could potentiate bio-activation and use of VitD, maintaining the homeostasis of the immune system. Interestingly, VitD-induced TIM-3 on T cells, a T cell inhibitory and anti-HIV-1 molecule, requires further studies to analyze the functional outcomes during HIV-1 infection.

Mammalian diversity: gametes, embryos and reproduction.

PubMed

Behringer, Richard R; Eakin, Guy S; Renfree, Marilyn B

2006-01-01

The class Mammalia is composed of approximately 4800 extant species. These mammalian species are divided into three subclasses that include the monotremes, marsupials and eutherians. Monotremes are remarkable because these mammals are born from eggs laid outside of the mother's body. Marsupial mammals have relatively short gestation periods and give birth to highly altricial young that continue a significant amount of 'fetal' development after birth, supported by a highly sophisticated lactation. Less than 10% of mammalian species are monotremes or marsupials, so the great majority of mammals are grouped into the subclass Eutheria, including mouse and human. Mammals exhibit great variety in morphology, physiology and reproduction. In the present article, we highlight some of this remarkable diversity relative to the mouse, one of the most widely used mammalian model organisms, and human. This diversity creates challenges and opportunities for gamete and embryo collection, culture and transfer technologies.

Children exposed to war/terrorism.

PubMed

Shaw, Jon A

2003-12-01

This paper reviews the prevalence of psychological morbidities in children who have been exposed to war-related traumas or terrorism as well as the diversity of war-related casualties and their associated psychological responses. The psychological responses to war-related stressors are categorized as (1) little or no reaction, (2) acute emotional and behavioral effects, and (3) long-term effects. Specific categories of war-related casualties discussed include refugee status, traumatic bereavement, effects of parental absence, and child soldiers. Psychological responses associated with terrorism and bioterrorism are presented. Lastly, mediators of the psychological response to war-related stressors are discussed, to include exposure effects, gender effects, parental, family and social factors, and child-specific factors. Children exposed to war-related stressors experience a spectrum of psychological morbidities including posttraumatic stress symptomatology, mood disorders, externalizing and disruptive behaviors, and somatic symptoms determined by exposure dose effect. Specific questions for future research are identified.

[Color vision impairment in workers exposed to mercury vapor].

PubMed

Jedrejko, Marta; Skoczyńska, Anna

2011-01-01

Acquired reversible dyschromatopsia has been associated with occupational exposure to mercury vapor. Early-detected impairments in color discrimination precede adverse permanent effects of mercury, so they may help to monitor the health of the exposed workers. The aim of this study was to evaluate the color discrimination ability in this group of workers, using Lanthony D-15d test. Employed in a chloralkali plant, 27 male workers exposed to mercury vapor and 27 healthy white-collar workers (control group) were qualified for the study. To assess color discrimination, the Lanthony 15-Hue desaturated test (Lanthony D-15) was used. In order to investigate quantitative and qualitative results, the Lanthony D-15d scoring software was performed. Urinary mercury was determined using flameless atomic absorption spectrometry. In the workers exposed to mercury vapor, urine mercury concentration was 117.4 +/- 62.6 microg/g creatinine on average compared with 0.279 +/- 0.224 mg/g creatinine in the control group (p < 0.0001). In 18 exposed persons (66.7%), the results of the Lanthony D-15d test showed qualitative changes, which are borderline corresponding to the early stage of developing dyschromatopsia type III. The quantitative analysis of the test findings indicated a significantly higher value of the Color Confusion Index (CCI) in the right eye in the exposed group compared to the control group (p = 0.01), with no significant difference in the CCI in the left eye. In the exposed group, the CCI in the right eye was significantly higher than the CCI in the left eye (p = 0.0005). There was neither correlation between CCI and the level of urinary mercury, nor between CCI and duration of exposure. The results showed that the Lanthony D-15d test is useful in the detection of early toxic effects in the eyesight of the workers exposed to mercury vapor. The observed color vision impairments are borderline corresponding to the early stage of developing dyschromatopsia type III.

Obstetric Outcomes of Mothers Previously Exposed to Sexual Violence.

PubMed

Gisladottir, Agnes; Luque-Fernandez, Miguel Angel; Harlow, Bernard L; Gudmundsdottir, Berglind; Jonsdottir, Eyrun; Bjarnadottir, Ragnheidur I; Hauksdottir, Arna; Aspelund, Thor; Cnattingius, Sven; Valdimarsdottir, Unnur A

2016-01-01

There is a scarcity of data on the association of sexual violence and women's subsequent obstetric outcomes. Our aim was to investigate whether women exposed to sexual violence as teenagers (12-19 years of age) or adults present with different obstetric outcomes than women with no record of such violence. We linked detailed prospectively collected information on women attending a Rape Trauma Service (RTS) to the Icelandic Medical Birth Registry (IBR). Women who attended the RTS in 1993-2010 and delivered (on average 5.8 years later) at least one singleton infant in Iceland through 2012 formed our exposed cohort (n = 1068). For each exposed woman's delivery, nine deliveries by women with no RTS attendance were randomly selected from the IBR (n = 9126) matched on age, parity, and year and season of delivery. Information on smoking and Body mass index (BMI) was available for a sub-sample (n = 792 exposed and n = 1416 non-exposed women). Poisson regression models were used to estimate Relative Risks (RR) with 95% confidence intervals (CI). Compared with non-exposed women, exposed women presented with increased risks of maternal distress during labor and delivery (RR 1.68, 95% CI 1.01-2.79), prolonged first stage of labor (RR 1.40, 95% CI 1.03-1.88), antepartum bleeding (RR 1.95, 95% CI 1.22-3.07) and emergency instrumental delivery (RR 1.16, 95% CI 1.00-1.34). Slightly higher risks were seen for women assaulted as teenagers. Overall, we did not observe differences between the groups regarding the risk of elective cesarean section (RR 0.86, 95% CI 0.61-1.21), except for a reduced risk among those assaulted as teenagers (RR 0.56, 95% CI 0.34-0.93). Adjusting for maternal smoking and BMI in a sub-sample did not substantially affect point estimates. Our prospective data suggest that women with a history of sexual assault, particularly as teenagers, are at increased risks of some adverse obstetric outcomes.

α-Crystallins Are Small Heat Shock Proteins: Functional and Structural Properties.

PubMed

Tikhomirova, T S; Selivanova, O M; Galzitskaya, O V

2017-02-01

During its life cycle, a cell can be subjected to various external negative effects. Many proteins provide cell protection, including small heat shock proteins (sHsp) that have chaperone-like activity. These proteins have several important functions involving prevention of apoptosis and retention of cytoskeletal integrity; also, sHsp take part in the recovery of enzyme activity. The action mechanism of sHsp is based on the binding of hydrophobic regions exposed to the surface of a molten globule. α-Crystallins presented in chordate cells as two αA- and αB-isoforms are the most studied small heat shock proteins. In this review, we describe the main functions of α-crystallins, features of their secondary and tertiary structures, and examples of their partners in protein-protein interactions.

The AMINO experiment: exposure of amino acids in the EXPOSE-R experiment on the International Space Station and in laboratory

NASA Astrophysics Data System (ADS)

Bertrand, Marylène; Chabin, Annie; Colas, Cyril; Cadène, Martine; Chaput, Didier; Brack, Andre; Cottin, Herve

2015-01-01

In order to confirm the results of previous experiments concerning the chemical behaviour of organic molecules in the space environment, organic molecules (amino acids and a dipeptide) in pure form and embedded in meteorite powder were exposed in the AMINO experiment in the EXPOSE-R facility onboard the International Space Station. After exposure to space conditions for 24 months (2843 h of irradiation), the samples were returned to the Earth and analysed in the laboratory for reactions caused by solar ultraviolet (UV) and other electromagnetic radiation. Laboratory UV exposure was carried out in parallel in the Cologne DLR Center (Deutsches Zentrum für Luft und Raumfahrt). The molecules were extracted from the sample holder and then (1) derivatized by silylation and analysed by gas chromatography coupled to a mass spectrometer (GC-MS) in order to quantify the rate of degradation of the compounds and (2) analysed by high-resolution mass spectrometry (HRMS) in order to understand the chemical reactions that occurred. The GC-MS results confirm that resistance to irradiation is a function of the chemical nature of the exposed molecules and of the wavelengths of the UV light. They also confirm the protective effect of a coating of meteorite powder. The most altered compounds were the dipeptides and aspartic acid while the most robust were compounds with a hydrocarbon chain. The MS analyses document the products of reactions, such as decarboxylation and decarbonylation of aspartic acid, taking place after UV exposure. Given the universality of chemistry in space, our results have a broader implication for the fate of organic molecules that seeded the planets as soon as they became habitable as well as for the effects of UV radiation on exposed molecules at the surface of Mars, for example.

Electron microscope observations of impact crater debris amongst contaminating particulates on materials surfaces exposed in space in low-Earth orbit

NASA Technical Reports Server (NTRS)

Murr, L. E.; Rivas, J. M.; Quinones, S.; Niou, C.-S.; Advani, A. H.; Marquez, B.

1993-01-01

Debris particles extracted from a small sampling region on the leading edge of the Long Duration Exposure Facility (LDEF) spacecraft have been examined by analytical transmission electron microscopy and the elemental frequency observed by energy-dispersive X-ray spectrometry and compared with upper atmosphere (Earth) particle elemental frequency and the average elemental compositions of interplanetary dust particles. A much broader elemental distribution was observed for the exposed spacecraft surface debris milieu. Numerous metal microfragment analyses, particularly aluminum and stainless steel, were compared with scanning electron microscope observations-of impact crater features, and the corresponding elemental spectra on selected LDEF aluminium tray clamps and stainless steel bolts. The compositions and melt features for these impact craters and ejecta have been shown to be consistent with microcrystalline debris fragments in the case of aluminum, and these observations suggest an ever changing debris milieu on exposed surfaces for space craft and space system materials.

Parasitism by Ixodes didelphidis and I. loricatus (Acari: Ixodidae) on small wild mammals from an Atlatic Forest in the State of Sao Paulo, Brazil.

PubMed

Barros-Battesti, D M; Yoshinari, N H; Bonoldi, V L; De Castro Gomes, A

2000-11-01

From January 1995 to June 1996, ticks were studied in a fragment of Atlantic Forest in a residential area in the city of Itapevi, State of Sao Paulo, Brazil. Cases of human Lyme disease-like illness were registered in this area during the spring of 1992. The monthly relative density of ticks was determined and the influence of seasonal climatic conditions was evaluated as well as the relationship between ticks and hosts. Ticks (n = 88) were collected from small mammals captured (n = 134) in monthly trappings where the traps were operated for five consecutive days. Immature ticks (n = 42, 47.7%) were identified as Ixodes spp. The adult ticks (n = 46, 52.3%) were identified as Ixodes didelphidis Fonseca and Aragão (n = 19, 21.6%), I. loricatus Neumann (n = 26, 29.5%) and Amblyomma cajennense (F.) (n = 1, 1.1%). The monthly correlations between tick numbers and meteorological data were not significant. The correlation between the different stages of ticks and the two seasons (cold-dry and warm-rainy) indicated that both immature and adult ticks showed a seasonal pattern of abundance. The highest numbers of immature ticks were observed on rodents, during the cold-dry season (from April to September) with a peak in August 1995. Adults ticks were predominant during the warm-rainy season (from October to March) with a peak in January 1995. Adult ticks were only collected on marsupials.

Reactivity and Regulation in Children Prenatally Exposed to Cocaine

ERIC Educational Resources Information Center

Dennis, Tracy; Bendersky, Margaret; Ramsay, Douglas; Lewis, Michael

2006-01-01

Children prenatally exposed to cocaine may be at elevated risk for adjustment problems in early development because of greater reactivity and reduced regulation during challenging tasks. Few studies have examined whether cocaine-exposed children show such difficulties during the preschool years, a period marked by increased social and cognitive…

Influence of a propagative plant virus on the fitness and wing dimorphism of infected and exposed insect vectors.

PubMed

Higashi, Clesson H V; Bressan, Alberto

2013-07-01

To maximize fitness, plant pathogenic viruses may manipulate their arthropod vectors through direct and indirect (via the host plant) interactions. For many virus-vector-plant associations, insect feeding does not always lead to virus acquisition. In fact, many plant viruses, especially those that propagate into their vectors, are acquired at low rates. Although the majority of insects colonizing an infected plant escape from viral infection, they are still exposed to the indirect effects (i.e. the effect of plant metabolism modification following virus infection). Little information has been reported on the effects of plant viruses on insects that become infected versus those that do not (here referred to as "exposed"). The effect that the Maize mosaic virus (MMV) (Rhabdoviridae) exerts on the fitness and wing dimorphism of the planthopper vector, Peregrinus maidis (Hemiptera, Delphacidae), that developed on leaves from either young or old corn plants was examined. MMV exerted non-consistent to minimal direct effects on developmental time, longevity, nymphal mortality and fecundity. In addition, some small yet significant fitness costs were encountered by exposed planthoppers to escape MMV infection. Furthermore, a significantly higher proportion of macropters over brachypters were produced on MMV-infected old leaves compared with healthy leaves of a similar age. We conclude that the virus influences the dispersal of the vector, promoting a larger production of macropters at the costs of brachypters at a late stage of the plant infection. Because MMV infection in planthoppers did not segregate by wing morphotype, our results indicate that the dispersal of both infected and exposed planthoppers was a likely consequence of the indirect effects of MMV.

Probiotics Reduce Necrotizing Enterocolitis Severity in HIV-exposed Premature Infants.

PubMed

Van Niekerk, Evette; Nel, Daniel G; Blaauw, Reneé; Kirsten, Gert F

2015-06-01

To assess the effect of probiotics on the incidence of necrotizing enterocolitis (NEC) in premature infants born to human immunodeficiency virus (HIV)-positive and HIV-negative women. HIV-exposed and HIV-unexposed premature infants were randomized to either the probiotic or the placebo group. The probiotic consisted of 1 × 10(9) colony-forming units, Lactobacillus rhamnosus GG and Bifidobacterium infantis per day. In total, 74 HIV-exposed and 110 HIV-unexposed infants were enrolled and randomized. The incidence of death [4 (5.4%) vs. 7 (6%); p = 0.79] and NEC [4 (5%) vs. 5 (5%); p = 0.76] did not differ significantly between the HIV-exposed and HIV-unexposed groups. A significant difference was found for total NEC incidence between the study and control groups [3 (3%) vs. 6 (6%); p = 0.029]. The incidence of NEC in the HIV-exposed group differed significantly [Bells I 2 (5%) vs. Bells III 2 (5%); p = 0.045). Probiotic supplementation reduced the incidence of NEC in the premature very low birth weight infants; however, results failed to show a lower incidence of NEC in HIV-exposed premature infants. A reduction in the severity of disease was found in the HIV-exposed study group. © The Author [2015]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The Strata-1 experiment on small body regolith segregation

NASA Astrophysics Data System (ADS)

Fries, Marc; Abell, Paul; Brisset, Julie; Britt, Daniel; Colwell, Joshua; Dove, Adrienne; Durda, Dan; Graham, Lee; Hartzell, Christine; Hrovat, Kenneth; John, Kristen; Karrer, Dakotah; Leonard, Matthew; Love, Stanley; Morgan, Joseph; Poppin, Jayme; Rodriguez, Vincent; Sánchez-Lana, Paul; Scheeres, Dan; Whizin, Akbar

2018-01-01

The Strata-1 experiment studies the mixing and segregation dynamics of regolith on small bodies by exposing a suite of regolith simulants to the microgravity environment aboard the International Space Station (ISS) for one year. This will improve our understanding of regolith dynamics and properties on small asteroids, and may assist in interpreting analyses of samples from missions to small bodies such as OSIRIS-REx, Hayabusa-1 and -2, and future missions to small bodies. The Strata-1 experiment consists of four evacuated tubes partially filled with regolith simulants. The simulants are chosen to represent models of regolith covering a range of complexity and tailored to inform and improve computational studies. The four tubes are regularly imaged while moving in response to the ambient vibrational environment using dedicated cameras. The imagery is then downlinked to the Strata-1 science team about every two months. Analyses performed on the imagery includes evaluating the extent of the segregation of Strata-1 samples and comparing the observations to computational models. After Strata-1's return to Earth, x-ray tomography and optical microscopy will be used to study the post-flight simulant distribution. Strata-1 is also a pathfinder for the new "1E" ISS payload class, which is intended to simplify and accelerate emplacement of experiments on board ISS.

Time profile of cosmic radiation exposure during the EXPOSE-E mission: the R3DE instrument.

PubMed

Dachev, Tsvetan; Horneck, Gerda; Häder, Donat-Peter; Schuster, Martin; Richter, Peter; Lebert, Michael; Demets, Rene

2012-05-01

The aim of this paper is to present the time profile of cosmic radiation exposure obtained by the Radiation Risk Radiometer-Dosimeter during the EXPOSE-E mission in the European Technology Exposure Facility on the International Space Station's Columbus module. Another aim is to make the obtained results available to other EXPOSE-E teams for use in their data analysis. Radiation Risk Radiometer-Dosimeter is a low-mass and small-dimension automatic device that measures solar radiation in four channels and cosmic ionizing radiation as well. The main results of the present study include the following: (1) three different radiation sources were detected and quantified-galactic cosmic rays (GCR), energetic protons from the South Atlantic Anomaly (SAA) region of the inner radiation belt, and energetic electrons from the outer radiation belt (ORB); (2) the highest daily averaged absorbed dose rate of 426 μGy d(-1) came from SAA protons; (3) GCR delivered a much smaller daily absorbed dose rate of 91.1 μGy d(-1), and the ORB source delivered only 8.6 μGy d(-1). The analysis of the UV and temperature data is a subject of another article (Schuster et al., 2012 ).

Non-exposed endoscopic wall-inversion surgery for gastrointestinal stromal tumor

PubMed Central

Mitsui, Takashi; Aikou, Susumu; Niimi, Keiko; Fujishiro, Mitsuhiro; Seto, Yasuyuki

2018-01-01

Laparoscopic and endoscopic cooperative surgery (LECS) is an accepted method of laparoscopic wedge resection, which is minimally invasive, for gastrointestinal stromal tumors (GISTs). We established a type of LECS achieving a full-thickness resection, non-exposed endoscopic wall-inversion surgery (NEWS), in an effort to prevent exposure of the peritoneal cavity to gastric intraluminal contents. We employed this surgical technique in 28 gastric GIST patients. We failed to complete NEWS in the initial two patients and in one patient with a large tumor (40 mm × 35 mm), but otherwise carried out the procedure successfully. Although a learning effect is speculated to occur, based on a decreasing trend in the operation time, the median operation time was 184 minutes showing that NEWS is still a time-consuming method. No significant differences were recognized in tumor size or location, except near the esophagogastric junction (EGJ), nor in the cross-sectional circumference. NEWS is feasible and appears to be a good option, especially for small GISTs with mucosal ulceration rendering full-thickness enucleation by opening of the gastric wall unfeasible. PMID:29682624

Arsenic in Mexican children exposed to contaminated well water.

PubMed

Monroy-Torres, Rebeca; Macías, Alejandro E; Gallaga-Solorzano, Juan Carlos; Santiago-García, Enrique Javier; Hernández, Isabel

2009-01-01

This cross-sectional study measures the arsenic level in school children exposed to contaminated well water in a rural area in México. Arsenic was measured in hair by hydride generation atomic absorption spectrophotometry. Overall, 110 children were included (average 10 years-old). Among 55 exposed children, mean arsenic level on hair was 1.3 mg/kg (range <0.006-5.9). All unexposed children had undetectable arsenic levels. The high level of arsenic in water was associated to the level in hair. However, exposed children drank less well water at school or at home than unexposed children, suggesting that the use of contaminated water to cook beans, broths or soups may be the source of arsenic exposure.

Exposed subsurface ice sheets in the Martian mid-latitudes

NASA Astrophysics Data System (ADS)

Dundas, Colin M.; Bramson, Ali M.; Ojha, Lujendra; Wray, James J.; Mellon, Michael T.; Byrne, Shane; McEwen, Alfred S.; Putzig, Nathaniel E.; Viola, Donna; Sutton, Sarah; Clark, Erin; Holt, John W.

2018-01-01

Thick deposits cover broad regions of the Martian mid-latitudes with a smooth mantle; erosion in these regions creates scarps that expose the internal structure of the mantle. We investigated eight of these locations and found that they expose deposits of water ice that can be >100 meters thick, extending downward from depths as shallow as 1 to 2 meters below the surface. The scarps are actively retreating because of sublimation of the exposed water ice. The ice deposits likely originated as snowfall during Mars’ high-obliquity periods and have now compacted into massive, fractured, and layered ice. We expect the vertical structure of Martian ice-rich deposits to preserve a record of ice deposition and past climate.

[Effect of lead-exposed astrocytes on neuronal synaptic formation].

PubMed

Cui, Yan; Li, Tingting; Yu, Haiyang; Liao, Yingjun; Jin, Yaping

2014-09-01

To investigate the effect of lead-exposed astrocyte conditioned medium (ACM) on the synaptic formation of neurons and to provide reference for the mechanism of lead neurotoxicity. Astrocytes were cultured in the medium containing 50, 100, 200, 400, and 800 µmol/L lead acetate for 72 h. Alamar Blue was used to assess the cell viability of astrocytes, and then ACM was collected. Primarily cultured neurons were divided into six groups: pure culture group, non-glutamic acid (Glu)-induced ACM treatment group, Glu-induced lead-free ACM treatment group, and Glu-induced 50, 100, and 200 µmol/L lead acetate-exposed ACM treatment groups. Neurons were collected after being cultured in ACM for 24, 48, or 72 h. The content of synaptophysin (SYP) in neurons was determined by Western blot. The SYP expression in neurons was measured by immunofluorescence after being cultured in ACMfor 72 h. In all lead-exposed groups, the cell viability of astrocytes declined with increasing concentration of lead (P < 0.05). The Western blot showed that compared with the pure culture group, the non-Glu-induced ACM treatment group and Glu-induced lead- free ACM treatment group had significantly increased content of SYP in neurons (P < 0.01); compared with the non-Glu-induced ACM treatment group, the Glu-induced ACM treatment groups had significantly reduced SYP expression in neurons (P < 0.05); compared with the Glu-induced lead-free ACM treatment group, all lead-exposed ACM treatment groups had the content of SYP in neurons significantly reduced with increasing concentration of lead after 72-h culture (P < 0.01), the 200 µmol/L lead-exposed ACM treatment group had significantly reduced content of SYP in neurons after 48-h culture (P < 0.01), and all lead-exposed ACM treatment groups showed no significant changes in the content of SYP in neurons after 24-h culture. Double-labeling immunofluorescence of SYP showed that all lead-exposed ACM treatment groups had a significant decrease in the number

Obstetric Outcomes of Mothers Previously Exposed to Sexual Violence

PubMed Central

Gisladottir, Agnes; Luque-Fernandez, Miguel Angel; Harlow, Bernard L.; Gudmundsdottir, Berglind; Jonsdottir, Eyrun; Bjarnadottir, Ragnheidur I.; Hauksdottir, Arna; Aspelund, Thor; Cnattingius, Sven; Valdimarsdottir, Unnur A.

2016-01-01

Background There is a scarcity of data on the association of sexual violence and women's subsequent obstetric outcomes. Our aim was to investigate whether women exposed to sexual violence as teenagers (12–19 years of age) or adults present with different obstetric outcomes than women with no record of such violence. Methods We linked detailed prospectively collected information on women attending a Rape Trauma Service (RTS) to the Icelandic Medical Birth Registry (IBR). Women who attended the RTS in 1993–2010 and delivered (on average 5.8 years later) at least one singleton infant in Iceland through 2012 formed our exposed cohort (n = 1068). For each exposed woman's delivery, nine deliveries by women with no RTS attendance were randomly selected from the IBR (n = 9126) matched on age, parity, and year and season of delivery. Information on smoking and Body mass index (BMI) was available for a sub-sample (n = 792 exposed and n = 1416 non-exposed women). Poisson regression models were used to estimate Relative Risks (RR) with 95% confidence intervals (CI). Results Compared with non-exposed women, exposed women presented with increased risks of maternal distress during labor and delivery (RR 1.68, 95% CI 1.01–2.79), prolonged first stage of labor (RR 1.40, 95% CI 1.03–1.88), antepartum bleeding (RR 1.95, 95% CI 1.22–3.07) and emergency instrumental delivery (RR 1.16, 95% CI 1.00–1.34). Slightly higher risks were seen for women assaulted as teenagers. Overall, we did not observe differences between the groups regarding the risk of elective cesarean section (RR 0.86, 95% CI 0.61–1.21), except for a reduced risk among those assaulted as teenagers (RR 0.56, 95% CI 0.34–0.93). Adjusting for maternal smoking and BMI in a sub-sample did not substantially affect point estimates. Conclusion Our prospective data suggest that women with a history of sexual assault, particularly as teenagers, are at increased risks of some adverse obstetric outcomes. PMID:27007230

Cancer in patients with rheumatic diseases exposed to TNF antagonists.

PubMed

Carmona, Loreto; Abasolo, Lydia; Descalzo, Miguel A; Pérez-Zafrilla, Beatriz; Sellas, Agustí; de Abajo, Francisco; Gomez-Reino, Juan J

2011-08-01

To describe the risk of cancer in patients exposed to tumor necrosis factor (TNF) antagonists. The following 2 clinical cohorts were studied: (1) BIOBADASER 2.0: a registry of patients suffering from rheumatic diseases exposed to TNF antagonists (2531 rheumatoid arthritis (RA), 1488 spondyloarthropathies, and 675 other rheumatic conditions); and (2) EMECAR: a cohort of 789 RA patients not exposed to TNF antagonists. Cancer incidence rates (IR) per 1000 patient-years and incidence rate ratios (IRR) were calculated for BIOBADASER 2.0 and EMECAR patients. The IR over time in BIOBADASER 2.0 patients was analyzed by joinpoint regression. The IRR was estimated to compare cancer rates in exposed versus nonexposed RA patients. Standardized incidence and mortality ratios (SIR, SMR) were also estimated. Risk factors for cancer in patients exposed to TNF antagonists were investigated by generalized linear models. The SMR for cancer in BIODASER 2.0 was 0.67 (95% CI: 0.51-0.86), and the SIR was 0.1 (95% CI 0.03-0.23). The IR in RA patients exposed to TNF antagonists was 5.8 (95% CI: 4.4-7.6), and the adjusted IRR was 0.48 (95% CI: 0.09-2.45). The IR in patients with previous cancer was 26.4 (95% CI: 4.1-171.5). Age, chronic obstructive pulmonary disease, and steroids were associated with a higher risk of developing cancer. The IR decreased after the first 4 months of exposure, without statistical significance. Overall cancer and mortality rates in patients with rheumatic diseases exposed to TNF antagonists are no higher than in the background Spanish population. However special attention should be paid to elderly patients, those with previous cancers, and patients treated with steroids. Copyright © 2011 Elsevier Inc. All rights reserved.

EXPOSE-E: an ESA astrobiology mission 1.5 years in space.

PubMed

Rabbow, Elke; Rettberg, Petra; Barczyk, Simon; Bohmeier, Maria; Parpart, André; Panitz, Corinna; Horneck, Gerda; von Heise-Rotenburg, Ralf; Hoppenbrouwers, Tom; Willnecker, Rainer; Baglioni, Pietro; Demets, René; Dettmann, Jan; Reitz, Guenther

2012-05-01

The multi-user facility EXPOSE-E was designed by the European Space Agency to enable astrobiology research in space (low-Earth orbit). On 7 February 2008, EXPOSE-E was carried to the International Space Station (ISS) on the European Technology Exposure Facility (EuTEF) platform in the cargo bay of Space Shuttle STS-122 Atlantis. The facility was installed at the starboard cone of the Columbus module by extravehicular activity, where it remained in space for 1.5 years. EXPOSE-E was returned to Earth with STS-128 Discovery on 12 September 2009 for subsequent sample analysis. EXPOSE-E provided accommodation in three exposure trays for a variety of astrobiological test samples that were exposed to selected space conditions: either to space vacuum, solar electromagnetic radiation at >110 nm and cosmic radiation (trays 1 and 3) or to simulated martian surface conditions (tray 2). Data on UV radiation, cosmic radiation, and temperature were measured every 10 s and downlinked by telemetry. A parallel mission ground reference (MGR) experiment was performed on ground with a parallel set of hardware and samples under simulated space conditions. EXPOSE-E performed a successful 1.5-year mission in space.

Mortality among Canadian military personnel exposed to low-dose radiation.

PubMed

Raman, S; Dulberg, C S; Spasoff, R A; Scott, T

1987-05-15

We carried out a cohort study of mortality among 954 Canadian military personnel exposed to low-dose ionizing radiation during nuclear reactor clean-up operations at Chalk River Nuclear Laboratories, Chalk River, Ont., and during observation of atomic test blasts in the United States and Australia in the 1950s. Two controls matched for age, service, rank and trade were selected for each exposed subject. Mortality among the exposed and control groups was ascertained by means of record linkage with the Canadian Mortality Data Base. Survival analysis with life-table techniques did not reveal any difference in overall mortality between the exposed and control groups. Analysis of cause-specific mortality showed similar mortality patterns in the two groups; there was no elevation in the exposed group in the frequency of death from leukemia or thyroid cancer, the causes of death most often associated with radiation exposure. Analysis of survival by recorded gamma radiation dose also did not show any effect of radiation dose on mortality. The findings are in agreement with the current scientific literature on the risk of death from exposure to low-dose radiation.

Evaluation of Dynamic Disulphide/Thiol Homeostasis in Silica Exposed Workers

PubMed Central

Gündüzöz, Meşide; Bal, Ceylan; Büyükşekerci, Murat; Neşelioğlu, Salim; Nadir Öziş, Türkan; İritaş, Servet; Kara, Halil; Erel, Özcan

2017-01-01

Background: Oxidative stress is implicated as one of the main molecular mechanism underlying silicosis. Aims: In this study, our aim was to asses the redox status in occupationally silica-exposed workers, by evaluating the dynamic thiol-disulphide homeostasis. Study Design: Case-control study. Methods: Thirty-six male workers occupationally exposed to silica particles and 30 healthy volunteers, working as office workers were included to the study. Posteroanterior chest radiographs and pulmonary function tests of both groups were evaluated. Also serum thiol disulphide levels were measured using the spectrophotometric method described by Erel and Neşelioğlu. Results: Among the 36 workers that underwent pulmonary function tests 6 (17%) had obstructive, 7 (19%) had restrictive, 6 (17%) had obstructive and restrictive signs whereas 17 (47%) had no signs. The mean PFTs results of silica-exposed workers were significantly lower than control subjects. The serum disulphide levels of silica-exposed workers were significantly higher than control subjects (23.84±5.89 μmol/L and 21.18±3.44 μmol/L, respectively p=0.02). Conclusion: The serum disulphide levels, a biomarker of oxidative stress, are found to be higher in silica-exposed workers. PMID:28418335

Integrated chemiresistor array for small sensor platforms

DOE Office of Scientific and Technical Information (OSTI.GOV)

HUGHES,ROBERT C.; CASALNUOVO,STEPHEN A.; WESSENDORF,KURT O.

2000-04-13

Chemiresistors are fabricated from materials that change their electrical resistance when exposed to certain chemical species. Composites of soluble polymers with metallic particles have shown remarkable sensitivity to many volatile organic chemicals, depending on the ability of the analyte molecules to swell the polymer matrix. These sensors can be made extremely small (< 100 square microns), operate at ambient temperatures, and require almost no power to read-out. However, the chemiresistor itself is only a part of a more complex sensor system that delivers chemical information to a user who can act on the information. The authors present the design, fabricationmore » and performance of a chemiresistor array chip with four different chemiresistor materials, heaters and a temperature sensor. They also show the design and fabrication of an integrated chemiresistor array, where the electronics to read-out the chemiresistors is on the same chip with the electrodes for the chemiresistors. The circuit was designed to perform several functions to make the sensor data more useful. This low-power, integrated chemiresistor array is small enough to be deployed on a Sandia-developed microrobot platform.« less

Semen quality of workers occupationally exposed to hydrocarbons.

PubMed

De Celis, R; Feria-Velasco, A; González-Unzaga, M; Torres-Calleja, J; Pedrón-Nuevo, N

2000-02-01

To determine whether occupational exposure of men to hydrocarbons has adverse effects on the quality of their semen. Comparative study. The rubber industry in Mexico City. Forty-eight workers who were exposed to hydrocarbons for 2-24 years and 42 unexposed workers. None. Environmental hydrocarbon concentrations were determined by continuous air monitoring in all areas of the factory. Analyses of semen samples were performed in accordance with World Health Organization criteria. Hydrocarbon concentrations were as follows: ethylbenzene, 220.7-234 mg/m3; benzene, 31.9-47.8 mg/m3; toluene, 189.7-212.5 mg/m3; and xylene, 47-56.4 mg/m3. The number of subjects with ejaculates that had normal characteristics was greater in the unexposed group (76%) than in the exposed group (17%). More abnormal characteristics were found in the semen of exposed workers than unexposed workers, including alterations in viscosity, liquefaction capacity, sperm count, sperm motility, and the proportion of sperm with normal morphology. Some abnormal characteristics correlated with the number of years of exposure to the hydrocarbons. Damage to the spermatogenic process resulting from hydrocarbon exposure was demonstrated by an increased rate of abnormalities in the semen of exposed workers compared with unexposed workers. This information may be useful for conducting future analyses of reproductive risks related to exposure to high concentrations of hydrocarbons.

Mediators and Treatment Factors in Intervention for Children Exposed to Interparental Violence.

PubMed

Overbeek, Mathilde M; De Schipper, J Clasien; Willemen, Agnes M; Lamers-Winkelman, Francien; Schuengel, Carlo

2017-01-01

Changes in children's emotion differentiation, coping skills, parenting stress, parental psychopathology, and parent-child interaction were explored as mediators of treatment factors in two selective preventive group interventions for children exposed to interparental violence (IPV) and their parents. One hundred thirty-four IPV-exposed children (ages 6-12 years, 52% boys) and their parents were randomized to an IPV-focused or common factors community-based group intervention and completed baseline, posttest, and follow-up assessments for posttraumatic stress (PTS). A multilevel model tested mediators that included children's ability to differentiate emotions and coping skills, parenting stress, parental psychopathology, and parent-child interactions. In both conditions, exposure to nonspecific factors, specific factors unrelated to IPV and trauma-specific intervention factors was coded from videotaped child and parent sessions. Improved parental mental health mediated the link between greater exposure to nonspecific treatment factors and decreases in PTS symptoms. In addition, an increase in emotion differentiation and a decrease in parenting stress were associated with a decrease in PTS symptoms. Greater exposure to trauma-specific factors in child sessions was associated with a small decrease in emotion differentiation, an increase in coping skills, and a decrease in PTS symptoms over time. Greater exposure to nonspecific treatment factors in child and parent sessions was associated with more positive parent-child interaction. Parental mental health appears to be an important mechanism of change that can be promoted through exposure to nonspecific factors in parent intervention. For children, the effect of greater exposure to trauma-specific factors in intervention is less clear and may not have clear benefits.

Evolution of organic molecules under Mars-like UV radiation with EXPOSE-R2, a photochemistry experiment outside the International Space Station

NASA Astrophysics Data System (ADS)

Rouquette, Laura; Stalport, Fabien; Cottin, Hervé; Coll, Patrice; Szopa, Cyril; Saiagh, Kafila; Poch, Olivier; Khalaf, Diana; Chaput, Didier; Grira, Katia; Chaouche, Naila; Dequaire, Tristan

2016-10-01

The detection and identification of organic molecules on Mars are of prime importance, as some of these molecules are life precursors and components. While in situ planetary missions are searching for them, it is essential to understand how organic molecules evolve and are preserved at the surface of Mars. Indeed the harsh conditions of the environment of Mars such as ultraviolet (UV) radiation or oxidative processes could explain the low abundance and diversity of organic molecules detected by now.The EXPOSE R2 facility has been placed in low Earth orbit (LEO) under solar radiation, outside the International Space Station (ISS) in 2014. One of the EXPOSE R2 experiment, called PSS (Photochemistry on the Space Station), is dedicated to astrobiology- and astrochemistry-related studies. Part of PSS samples have been dedicated to the study of the evolution of organic molecules under Mars-like surface radiation conditions. Indeed, UV radiation above 200 nm reaches the surface of Mars and could degrade organic matter. Organic samples have been exposed directly to the Sun under KBr filters (>200 nm) from November 2014 to February 2016, mimicking the UV radiation conditions of the surface of Mars. Four types of samples were exposed as thin layers of solid molecules: adenine, adenine with nontronite (a kind of clay mineral detected on Mars), chrysene and glycine with nontronite.To characterize the evolution of our samples under irradiation, infrared (IR) transmission analyses were performed, before the launch of EXPOSE R2 to the ISS in 2014, and after the exposure in space and the return on Earth, this year. These analyses allowed determining whether each molecule is preserved or photodegraded, and if so, its photolysis rate. The effect of nontronite on organic molecules preservation has been investigated as well. We also compared these results from LEO with laboratory data, obtained by irradiating organic samples under a UV lamp.

Exposure to celebrity-endorsed small cigar promotions and susceptibility to use among young adult cigarette smokers.

PubMed

Sterling, Kymberle L; Moore, Roland S; Pitts, Nicole; Duong, Melissa; Ford, Kentya H; Eriksen, Michael P

2013-01-01

Small cigar smoking among young adult cigarette smokers may be attributed to their exposure to its advertisements and promotions. We examined the association between exposure to a celebrity music artist's endorsement of a specific brand of small cigars and young adult cigarette smokers' susceptibility to smoking that brand. Venue-based sampling procedures were used to select and survey a random sample of 121 young adult cigarette smokers, aged 18-35. Fourteen percent reported exposure to the artist's endorsement of the small cigar and 45.4% reported an intention to smoke the product in the future. The odds of small cigar smoking susceptibility increased threefold for those who reported exposure to the endorsement compared to those not exposed (OR = 3.64, 95% CI 1.06 to 12.54). Past 30-day small cigar use (OR = 3.30, 95% CI 1.24 to 8.74) and past 30-day cigar use (OR = 5.08, 95% CI 1.23, 21.08) were also associated with susceptibility to smoke a small cigar. An association between young adult cigarette smokers' exposure to the music artist's small cigar endorsement and their susceptibility to smoke small cigars was found. This association underscores the importance of monitoring small cigar promotions geared toward young people and their impact on small cigar product smoking.

TREATMENT OF LEAD EXPOSED CHILDREN TRIAL

EPA Science Inventory

The Treatment of Lead-exposed Children (TLC) clinical trial compared the effect of lead chelation with succimer to placebo therapy. Outcomes included IQ, neuropsychological function, behavior, physical growth and blood pressure three years after initiation of treatment. Residenti...

Effects of monochromatic light on mucosal mechanical and immunological barriers in the small intestine of broilers.

PubMed

Xie, D; Li, J; Wang, Z X; Cao, J; Li, T T; Chen, J L; Chen, Y X

2011-12-01

Our previous studies demonstrated that green and blue monochromatic lights were effective to stimulate immune response of the spleen in broilers. This study was designed to investigate the effects of monochromatic light on both gut mucosal mechanical and immunological barriers. A total of 120 Arbor Acre male broilers on post-hatching day (P) 0 were exposed to red light, green light (GL), blue light (BL), and white light (WL) for 49 d, respectively. As compared with broilers exposed to WL, the broilers exposed to GL showed that the villus height of small intestine was increased by 19.5% (P = 0.0205) and 38.8% (P = 0.0149), the crypt depth of small intestine was decreased by 15.1% (P = 0.0049) and 10.1% (P = 0.0005), and the ratios of villus height to crypt depth were increased by 39.3% (P < 0.0001) and 52.5% (P < 0.0001) at P7 and P21, respectively. Until P49, an increased villus height (33.6%, P = 0.0076), a decreased crypt depth (15.4%, P = 0.0201), and an increased villus height-to-crypt depth ratio (58.5%, P < 0.0001) were observed in the BL group as compared with the WL group. On the other hand, the numbers of intestinal intraepithelial lymphocytes (27.9%, P < 0.0001 and 37.0%, P < 0.0001), goblet cells (GC, 22.1%, P < 0.0001 and 18.1%, P < 0.0001), and IgA(+) cells (14.8%, P = 0.0543 and 47.9%, P = 0.0377) in the small intestine were significantly increased in the GL group as compared with the WL group at P7 and P21, respectively. The numbers of intestinal intraepithelial lymphocytes (36.2%, P < 0.0001), GC (26.5%, P < 0.0001), and IgA(+) cells (68.0%, P = 0.0177) in the BL group were also higher than those in the WL group at P49. These results suggest that both mucosal mechanical and immunological barriers of the small intestine may be improved by rearing broilers under GL at an early age and under BL at an older age.

Cryogenic Thermal Absorptance Measurements on Small-Diameter Stainless Steel Tubing

NASA Technical Reports Server (NTRS)

Tuttle, James; Jahromi, Amir; Canavan, Edgar; DiPirro, Michael

2015-01-01

The Mid Infrared Instrument (MIRI) on the James Webb Space Telescope includes a mechanical cryocooler which cools its detectors to their 6 Kelvin operating temperature. The coolant gas flows through several meters of small-diameter stainless steel tubing, which is exposed to thermal radiation from its environment. Over much of its length this tubing is gold-plated to minimize the absorption of this radiant heat. In order to confirm that the cryocooler will meet MIRI's requirements, the thermal absorptance of this tubing was measured as a function of its environment temperature. We describe the measurement technique and present the results.

Menstrual function among women exposed to polybrominated biphenyls: A follow-up prevalence study

PubMed Central

Davis, Stephanie I; Blanck, Heidi Michels; Hertzberg, Vicki S; Tolbert, Paige E; Rubin, Carol; Cameron, Lorraine L; Henderson, Alden K; Marcus, Michele

2005-01-01

Background Alteration in menstrual cycle function is suggested among rhesus monkeys and humans exposed to polybrominated biphenyls (PBBs) and structurally similar polychlorinated biphenyls (PCBs). The feedback system for menstrual cycle function potentially allows multiple pathways for disruption directly through the hypothalamic-pituitary-ovarian axis and indirectly through alternative neuroendocrine axes. Methods The Michigan Female Health Study was conducted during 1997–1998 among women in a cohort exposed to PBBs in 1973. This study included 337 women with self-reported menstrual cycles of 20–35 days (age range: 24–56 years). Current PBB levels were estimated by exponential decay modeling of serum PBB levels collected from 1976–1987 during enrollment in the Michigan PBB cohort. Linear regression models for menstrual cycle length and the logarithm of bleed length used estimated current PBB exposure or enrollment PBB exposure categorized in tertiles, and for the upper decile. All models were adjusted for serum PCB levels, age, body mass index, history of at least 10% weight loss in the past year, physical activity, smoking, education, and household income. Results Higher levels of physical activity were associated with shorter bleed length, and increasing age was associated with shorter cycle length. Although no overall association was found between PBB exposure and menstrual cycle characteristics, a significant interaction between PBB exposures with past year weight loss was found. Longer bleed length and shorter cycle length were associated with higher PBB exposure among women with past year weight loss. Conclusion This study suggests that PBB exposure may impact ovarian function as indicated by menstrual cycle length and bleed length. However, these associations were found among the small number of women with recent weight loss suggesting either a chance finding or that mobilization of PBBs from lipid stores may be important. These results should be

Shape Mode Analysis Exposes Movement Patterns in Biology: Flagella and Flatworms as Case Studies

PubMed Central

Werner, Steffen; Rink, Jochen C.; Riedel-Kruse, Ingmar H.; Friedrich, Benjamin M.

2014-01-01

We illustrate shape mode analysis as a simple, yet powerful technique to concisely describe complex biological shapes and their dynamics. We characterize undulatory bending waves of beating flagella and reconstruct a limit cycle of flagellar oscillations, paying particular attention to the periodicity of angular data. As a second example, we analyze non-convex boundary outlines of gliding flatworms, which allows us to expose stereotypic body postures that can be related to two different locomotion mechanisms. Further, shape mode analysis based on principal component analysis allows to discriminate different flatworm species, despite large motion-associated shape variability. Thus, complex shape dynamics is characterized by a small number of shape scores that change in time. We present this method using descriptive examples, explaining abstract mathematics in a graphic way. PMID:25426857

Biomonitoring of Toxic Effects of Pesticides in Occupationally Exposed Individuals.

PubMed

Arshad, Muhammad; Siddiqa, Maryam; Rashid, Saddaf; Hashmi, Imran; Awan, Muhammad Ali; Ali, Muhammad Arif

2016-06-01

Workers in pesticide manufacturing industries are constantly exposed to pesticides. Genetic biomonitoring provides an early identification of potential cancer and genetic diseases in exposed populations. The objectives of this biomonitoring study were to assess DNA damage through comet assay in blood samples collected from industry workers and compare these results with those of classical analytical techniques used for complete blood count analysis. Samples from controls (n = 20) and exposed workers (n = 38) from an industrial area in Multan, Pakistan, were subjected to various tests. Malathion residues in blood samples were measured by gas chromatography. The exposed workers who were employed in the pesticide manufacturing industry for a longer period (i.e., 13-25 years) had significantly higher DNA tail length (7.04 μm) than the controls (0.94 μm). Workers in the exposed group also had higher white blood cell and red blood cell counts, and lower levels of mean corpuscular hemoglobin (MCH), MCH concentration, and mean corpuscular volume in comparison with normal levels for these parameters. Malathion was not detected in the control group. However, in the exposed group, 72% of whole blood samples had malathion with a mean value of 0.14 mg/L (range 0.01-0.31 mg/L). We found a strong correlation (R (2) = 0.91) between DNA damage in terms of tail length and malathion concentration in blood. Intensive efforts and trainings are thus required to build awareness about safety practices and to change industrial workers' attitude to prevent harmful environmental and anthropogenic effects.

Nature Drilling Exposes Deeply Buried Minerals

NASA Image and Video Library

2011-03-08

This image from NASA Mars Global Surveyor and Mars Odyssey spacecraft shows the context for orbital observations of exposed rocks that had been buried on Mars. The area is dominated by the Huygens crater, which is about the size of Wisconsin.

A multicenter study on the audiometric findings of styrene-exposed workers.

PubMed

Morata, Thais C; Sliwinska-Kowalska, Mariola; Johnson, Ann-Christin; Starck, Jukka; Pawlas, Krystyna; Zamyslowska-Szmytke, Ewa; Nylen, Per; Toppila, Esko; Krieg, Edward; Pawlas, Natalia; Prasher, Deepak

2011-10-01

The objective of this study was to evaluate hearing loss among workers exposed to styrene, alone or with noise. This cross-sectional study was conducted as part of NoiseChem, a European Commission 5th Framework Programme research project, by occupational health institutes in Finland, Sweden, and Poland. Participants' ages ranged from 18-72 years (n = 1620 workers). Participants exposed to styrene, alone or with noise, were from reinforced fiberglass products manufacturing plants (n = 862). Comparison groups were comprised of workers noise-exposed (n = 400) or controls (n = 358). Current styrene exposures ranged from 0 to 309 mg/m(3), while mean current noise levels ranged from 70-84 dB(A). Hearing thresholds of styrene-exposed participants were compared with Annexes A and B from ANSI S3.44, 1996. The audiometric thresholds of styrene exposed workers were significantly poorer than those in published standards. Age, gender, and styrene exposure met the significance level criterion in the multiple logistic regression for the binary outcome 'hearing loss' (P = 0.0000). Exposure to noise (<85 dBA p = 0.0001; ≥85 dB(A) p = 0.0192) interacted significantly with styrene exposure. Occupational exposure to styrene is a risk factor for hearing loss, and styrene-exposed workers should be included in hearing loss prevention programs.

Semen study of papaya workers exposed to ethylene dibromide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ratcliffe, J.M.; Schrader, S.M.; Steenland, K.

1984-01-01

A cross sectional semen and cytogenetic study was performed on male workers exposed to ethylene-dibromide (EDB) in the papaya fumigation industry in Hawaii. Semen analyses were conducted on 46 men in six fumigation facilities with an average length of employment of 5 years and airborne exposures to EDB ranging from 16 to 213 parts per billion. Statistically significant decreases in sperm count per ejaculate and the percentage of viable and motile sperm and increases in the proportion of specific morphological abnormalities were observed among exposed men when compared with controls. Semen volume and sperm concentration were also lower in themore » exposed group. No effect of exposure to EDB on sperm velocity, the overall proportion of sperm with normal morphology or YFF bodies was noted. The authors conclude that based on the decreases in sperm count, viability and motility and increases in certain types of morphological abnormalities among workers exposed to EDB, EDB may increase the risk of reproductive impairment in workers at exposure levels near the NIOSH recommended limit of 45 parts per billion and far below the current OSHA standard of 20 parts per million.« less

Increased levels of the acetaldehyde-derived DNA adduct N 2-ethyldeoxyguanosine in oral mucosa DNA from Rhesus monkeys exposed to alcohol

PubMed Central

Balbo, Silvia; Juanes, Rita Cervera; Khariwala, Samir; Baker, Erich J.; Daunais, James B.; Grant, Kathleen A.

2016-01-01

Alcohol is a human carcinogen. A causal link has been established between alcohol drinking and cancers of the upper aerodigestive tract, colon, liver and breast. Despite this established association, the underlying mechanisms of alcohol-induced carcinogenesis remain unclear. Various mechanisms may come into play depending on the type of cancer; however, convincing evidence supports the concept that ethanol’s major metabolite acetaldehyde may play a major role. Acetaldehyde can react with DNA forming adducts which can serve as biomarkers of carcinogen exposure and potentially of cancer risk. The major DNA adduct formed from this reaction is N 2-ethylidenedeoxyguanosine, which can be quantified as its reduced form N 2-ethyl-dG by LC-ESI-MS/MS. To investigate the potential use of N 2-ethyl-dG as a biomarker of alcohol-induced DNA damage, we quantified this adduct in DNA from the oral, oesophageal and mammary gland tissues from rhesus monkeys exposed to alcohol drinking over their lifetimes and compared it to controls. N 2-Ethyl-dG levels were significantly higher in the oral mucosa DNA of the exposed animals. Levels of the DNA adduct measured in the oesophageal mucosa of exposed animals were not significantly different from controls. A correlation between the levels measured in the oral and oesophageal DNA, however, was observed, suggesting a common source of formation of the DNA adducts. N 2-Ethyl-dG was measured in mammary gland DNA from a small cohort of female animals, but no difference was observed between exposed animals and controls. These results support the hypothesis that acetaldehyde induces DNA damage in the oral mucosa of alcohol-exposed animals and that it may play role in the alcohol-induced carcinogenic process. The decrease of N 2-ethyl-dG levels in exposed tissues further removed from the mouth also suggests a role of alcohol metabolism in the oral cavity, which may be considered separately from ethanol liver metabolism in the investigation of

Behavioral Treatment of Drug Exposed Infants: Analyzing and Treating Aggression.

ERIC Educational Resources Information Center

Burch, Mary R.

1992-01-01

Some children who are exposed to cocaine prenatally or in infancy exhibit neurological and behavioral difficulties or developmental delays in preschool. The causes and treatment of aggression in one child in a preschool program who had been prenatally exposed to cocaine is described. (SM)

SYSTEMS FOR EXPOSING MICE TO 2,450-MHZ ELECTROMAGNETIC FIELDS

EPA Science Inventory

Two systems for exposing mice to 2,450-MHz electromagnetic fields are described. In a waveguide system, four mice were placed in a Styrofoam cage and exposed dorsally to circularly polarized electromagnetic fields. The temperature and humidity in the mouse holder were kept consta...

Group protocol to mitigate disaster stress and enhance social support in adolescents exposed to Hurricane Hugo.

PubMed

Stewart, J B; Hardin, S B; Weinrich, S; McGeorge, S; Lopez, J; Pesut, D

1992-01-01

Literature reports that cognitive understanding and social support can mitigate stress in both adults and adolescents. As a subcomponent of the Carolina Adolescent Health Project (CAHP), this research evaluated the efficacy of a Cognitive Social Support (CSS) group protocol designed to mitigate the disaster stress of adolescents who had been exposed seriously to Hurricane Hugo. A purposive sample of 259 students participated in and evaluated the CSS. This article reports the specific structure, content, process, rationale, and cost of the CSS. Evaluations indicated that 82% of the students evaluated the small-group component of the CSS as "very good" or "excellent," while 70% rated the large-group component as "very good" or "excellent."

Time-dependent dielectric breakdown of plasma-exposed porous organosilicate glass

NASA Astrophysics Data System (ADS)

Nichols, M. T.; Sinha, H.; Wiltbank, C. A.; Antonelli, G. A.; Nishi, Y.; Shohet, J. L.

2012-03-01

Time-dependent dielectric breakdown (TDDB) is a major concern for low-k organosilicate dielectrics. To examine the effect of plasma exposure on TDDB degradation, time-to-breakdown measurements were made on porous SiCOH before and after exposure to plasma. A capillary-array window was used to separate charged particle and vacuum ultraviolet (VUV) photon bombardment. Samples exposed to VUV photons, and a combination of VUV photons and ion bombardment exhibited significant degradation in breakdown time. The samples exposed to VUV photons and ion bombardment showed more degradation in breakdown time in comparison to samples exposed to VUV photons alone.

Cancer risk in men exposed in utero to diethylstilbestrol.

PubMed

Strohsnitter, W C; Noller, K L; Hoover, R N; Robboy, S J; Palmer, J R; Titus-Ernstoff, L; Kaufman, R H; Adam, E; Herbst, A L; Hatch, E E

2001-04-04

An association between prenatal diethylstilbestrol (DES) exposure and cancer in men, especially testicular cancer, has been suspected, but findings from case-control studies have been inconsistent. This study was conducted to investigate the association between prenatal DES exposure and cancer risk in men via prospective follow-up. A total of 3613 men whose prenatal DES exposure status was known were followed from 1978 through 1994. The overall and site-specific cancer incidence rates among the DES-exposed men were compared with those of the unexposed men in the study and with population-based rates. The relative rate (RR) was used to assess the strength of the association between prenatal DES exposure and cancer development. All statistical tests were two-sided. Overall cancer rates among DES-exposed men were similar to those among unexposed men (RR = 1.07; 95% confidence interval [CI] = 0.58 to 1.96) and to national rates (RR = 0.99; 95% CI = 0.65 to 1.44). Testicular cancer may be elevated among DES-exposed men, since the RRs for testicular cancer were 3.05 (95% CI = 0.65 to 22.0) times those of unexposed men in the study and 2.04 (95% CI = 0.82 to 4.20) times those of males in the population-based rates. The higher rate of testicular cancer in the DES-exposed men is, however, also compatible with a chance observation. To date, men exposed to DES in utero do not appear to have an increased risk of most cancers. It remains uncertain, however, whether prenatal DES exposure is associated with testicular cancer.

Safety of in utero and neonatal antiretroviral exposure: cognitive and academic outcomes in HIV-exposed, uninfected children 5-13 years of age.

PubMed

Nozyce, Molly L; Huo, Yanling; Williams, Paige L; Kapetanovic, Suad; Hazra, Rohan; Nichols, Sharon; Hunter, Scott; Smith, Renee; Seage, George R; Sirois, Patricia A

2014-11-01

Long-term effects of in utero and neonatal antiretroviral (ARV) exposure on cognitive and academic development in HIV-exposed, uninfected school-age children are unknown. HIV-exposed, uninfected children, ages 5-13 years, in Pediatric HIV/AIDS Cohort Study Surveillance Monitoring for Antiretroviral Treatment Toxicities, a US-based multisite cohort study, completed age-appropriate Wechsler intelligence and academic scales (WPPSI-III, WASI, WIAT-II-A). Associations between cognitive and academic outcomes and in utero ARV exposure by regimen, class and individual ARVs were evaluated, adjusting for potential confounders. Children completing WPPSI-IIIs (n = 350) were 49% male, 74% Black, 25% Hispanic; WASI (n = 337) and WIAT-II-A (n = 415) cohorts were similar. The percentage exposed to combination ARV (cARV) was 84% (WPPSI-III), 64% (WASI) and 67% (WIAT-II-A). Among ARV-exposed children, there were no significant associations between any ARV regimen or class and any cognitive or academic outcome. In addition, in both unadjusted models and after adjustment for caregiver IQ, sociodemographic factors and maternal health and substance use during pregnancy, no individual ARV drug was associated with significantly lower cognitive or academic scores. Factors typically associated with lower cognitive and academic scores in the general population, such as prematurity, small for gestational age, maternal alcohol use and lower maternal cognitive status, were also associated with lower scores in this study. Overall, the safety of prenatal and neonatal ARV use was supported.

Modeling of erosion and deposition patterns on C-W and W-Ta twin limiters exposed to the TEXTOR edge plasmas

NASA Astrophysics Data System (ADS)

Ohya, K.; Tanabe, T.; Rubel, M.; Wada, M.; Ohgo, T.; Hirai, T.; Philipps, V.; Kirschner, A.; Pospieszczyk, A.; Huber, A.; Sergienko, G.; Brezinsek, S.; Noda, N.

2004-08-01

The erosion and deposition patterns on tungsten and tantalum test limiters exposed to the TEXTOR deuterium plasma containing a small amount of C impurity are simulated with the modified EDDY code. At the very top of the W and Ta limiters, there occurs neither erosion nor deposition, but the erosion proceeds slowly along the surface. When approaching the edge, the surface is covered by a thick C layer, which shows a very sharp boundary similar to the observation in surface measurements. In the erosion zone, the re-deposited carbon forms a W (Ta)-C mixed layer with small C concentration. Assumptions for chemical erosion yields of ˜0.01 for W and <0.005 for Ta fit the calculated widths of the deposition zone to the experimentally determined values. Possible reasons for the difference between W and Ta are discussed.

Pathological effects of obstructive apneas during the sleep cycle in an animal model of cerebral small vessel disease.

PubMed

Lloyd, Eric E; Durgan, David J; Martini, Sharyl R; Bryan, Robert M

2015-10-01

We tested the hypothesis that apneas during the sleep cycle exacerbate hypertension and accelerate changes that occur with cerebral small vessel disease. Obstructive sleep apnea was modeled by intermittent inflations of a chronically implanted tracheal balloon to occlude the airway during the sleep cycle (termed OSA) in spontaneously hypertensive stroke-prone (SHRSP) rats, a model of cerebral small vessel disease. SHRSP rats and their parent strain, Wistar Kyoto (WKY) rats, were exposed to OSA for 2 weeks (from 9 to 11 or from 18 to 20 weeks). At 9 weeks, hypertension was developing in the SHRSP rats and was firmly established by 18 weeks. OSA exposure increased systolic blood pressure in SHRSP rats by ≈30 mm Hg in both age groups compared with shams that were surgically prepared but not exposed to OSA (P<0.05). OSA exposure also increased systolic blood pressure in WKY rats by 20 and 37 mm Hg at 11 and 20 weeks, respectively (P<0.05). OSA exposure in SHRSP rats compromised blood-brain barrier integrity in white matter at both 11 and 20 weeks of age when compared with SHRSP sham rats (P<0.05). Microglia were activated in SHRSP rats exposed to OSA but not in sham rats at 11 weeks (P<0.05). At 20 weeks, microglia were activated in sham SHRSP rats (P<0.05) compared with WKY sham rats and were not further activated by OSA. Neither was blood-brain barrier integrity altered nor microglia activated in any of the WKY groups. We conclude that OSA accelerates the onset of the cerebral pathologies associated with cerebral small vessel disease in SHRSP, but not WKY, rats. © 2015 American Heart Association, Inc.

[Oxidative damage and immunotoxicity effect of people who exposed to electronic waste].

PubMed

Zhang, Ronghua; Xu, Caiju; Shen, Haitao; Tang, Yun; Meng, Jia; Lu, Wei; Wang, Xiaofeng; Lou, Xiaoming; Song, Yanhua; Han, Guangen; Cai, Delei; Ding, Gangqiang

2012-03-01

To investigate the relationship between risk factors and the effects of antioxidation and immune function in adults who exposed to electronic waste( e-waste). The exposed group was chosen from the people who lived in the e-waste disposing areas of Zhejiang province. The control group was chosen from people who lived in unpolluted area. Anticoagulation and coagulation peripheral venous blood samples were collected from 40 exposed persons (22 employees, 18 non-employees) and 36 exposed persons respectively. The oxidative, immune, Cd, Pb, Cr, Hg, and PCB indexes were detected. The contents of Cd, total PCB, MDA statistically increased in exposed group comparing with the control group (P < 0.05). The activity of SOD, GSH-Px, the percentage of helper/inducer T lymphocytes (CD4+) and the content of Cr in exposed group were less than those in the controlgroup (P < 0.05). Oxidative damage and immunotoxicity were observed in the group that lived in e-waste disposing areas. These effects were mainly related to the increase of Cd content or Cd and Pb contents in peripheral venous blood.

Is diagnosing exposed dentine a suitable tool for grading erosive loss?

PubMed Central

Ganss, Carolina

2008-01-01

Quantifying tooth wear in general and erosion in particular mostly is made by distinguishing between lesions restricted to enamel and lesions reaching the underlying dentine. Various scores for grading have been used, but in all systems, higher scores are given in cases of exposed dentine, thus, indicating a more severe stage of the condition. Clinical diagnosis of exposed dentine is made by assessing changes in colour or optical properties of the hard tissues. This paper aims to review the literature and discuss critically problems arising form this approach. It appears that classifying the severity of erosion by the area or depth of exposed dentine is difficult and poorly reproducible, and taking into account the variation of enamel thickness, the amount of tissue lost often is not related simply to the area of exposed dentine. There has still been very little longitudinal investigation of the significance of exposed dentine as a prognostic indicator. Further work and discussion is needed to reevaluate the explanative power of current grading procedures. PMID:18228063

Pacui virus, phlebotomine flies, and small mammals in Brazil: an epidemiological study.

PubMed

Aitken, T H; Woodall, J P; De Andrade, A H; Bensabath, G; Shope, R E

1975-03-01

Pacui virus, originally obtained from forest rodents, was isolated 100 times from 61,437 specimens (658 pools) of the phlebotomine fly Lutzomyia flaviscutellata, collected from rodent-baited traps in the forests of Belem, Para, Brazil in the period October 1968 through September 1970. Isolations were made from engorged and unengorged females and from males (3 strains), and occurred in all 24 months. Pacui virus also was isolated from the blood of two wild rodents (Oryzomys), but not from 424 L. infraspinosa, 12,000 mosquitoes, or sentinel mice. Pacui virus neutralizing antibodies were detected in serum of six bait animals after exposure to biting flies in the forest, in 30% of wild rodents surveyed (including two from Amapa Territory), and in 10% of marsupials, but were absent in human survey sera and in bats. Low-passage Pacui virus produced viremia in and was lethal to infant mice by the subcutaneous route. L. flaviscutellata was most abundant in the dry season, in which period Pacui virus isolations increased. This fly is strongly attracted to rodents close to the ground. L. flaviscutellata also yielded single strains of Guama, Icoaraci, and BeAr 177325 viruses.

Update of a cohort mortality study of workers exposed to methylene chloride employed at a plant producing cellulose triacetate film base.

PubMed

Tomenson, John A

2011-12-01

To update the mortality experience of employees of a factory that produced cellulose triacetate film base at Brantham in the United Kingdom and generate information on the effects of exposure to methylene chloride, in particular, mortality from cardiovascular disease and cancers of the lung, liver and biliary tract, pancreas and brain. All 1,785 male employees with a record of employment at the film factory in 1946-1988 were followed through 2006, including 1,473 subjects exposed to methylene chloride on average for 9 years at a concentration of 19 ppm (8 h time-weighted average). A total of 559 deaths occurred during the follow-up period. In the subcohort of workers exposed to methylene chloride, substantially reduced mortalities compared with national and local rates were found for all causes, all cancers, and all the principal cancer sites of interest except for brain cancer. There was a small excess of brain cancer deaths (8 observed and 4.4 expected), but no evidence of an association with exposure to methylene chloride. Lung cancer mortality was significantly reduced in exposed workers, even compared to the low mortality rate in the local population (SMR 55). In contrast, mortality from ischaemic heart disease in exposed workers was slightly increased compared with local rates (SMR 102), but was lower in active employees (SMR 94; local rates), where a direct effect of exposure to methylene chloride should be concentrated. The study provided no indication that employment at the plant, or exposure to methylene chloride, had adversely affected the mortalities of workers.

Time Profile of Cosmic Radiation Exposure During the EXPOSE-E Mission: The R3DE Instrument

PubMed Central

Horneck, Gerda; Häder, Donat-Peter; Schuster, Martin; Richter, Peter; Lebert, Michael; Demets, Rene

2012-01-01

Abstract The aim of this paper is to present the time profile of cosmic radiation exposure obtained by the Radiation Risk Radiometer-Dosimeter during the EXPOSE-E mission in the European Technology Exposure Facility on the International Space Station's Columbus module. Another aim is to make the obtained results available to other EXPOSE-E teams for use in their data analysis. Radiation Risk Radiometer-Dosimeter is a low-mass and small-dimension automatic device that measures solar radiation in four channels and cosmic ionizing radiation as well. The main results of the present study include the following: (1) three different radiation sources were detected and quantified—galactic cosmic rays (GCR), energetic protons from the South Atlantic Anomaly (SAA) region of the inner radiation belt, and energetic electrons from the outer radiation belt (ORB); (2) the highest daily averaged absorbed dose rate of 426 μGy d−1 came from SAA protons; (3) GCR delivered a much smaller daily absorbed dose rate of 91.1 μGy d−1, and the ORB source delivered only 8.6 μGy d−1. The analysis of the UV and temperature data is a subject of another article (Schuster et al., 2012). Key Words: Ionizing radiation—R3D—ISS. Astrobiology 12, 403–411. PMID:22680687

Epidemics in small world networks

NASA Astrophysics Data System (ADS)

Telo da Gama, M. M.; Nunes, A.

2006-03-01

For many infectious diseases, a small-world network on an underlying regular lattice is a suitable simplified model for the contact structure of the host population. It is well known that the contact network, described in this setting by a single parameter, the small-world parameter p, plays an important role both in the short term and in the long term dynamics of epidemic spread. We have studied the effect of the network structure on models of immune for life diseases and found that in addition to the reduction of the effective transmission rate, through the screening of infectives, spatial correlations may strongly enhance the stochastic fluctuations. As a consequence, time series of unforced Susceptible-Exposed-Infected-Recovered (SEIR) models provide patterns of recurrent epidemics with realistic amplitudes, suggesting that these models together with complex networks of contacts are the key ingredients to describe the prevaccination dynamical patterns of diseases such as measles and pertussis. We have also studied the role of the host contact strucuture in pathogen antigenic variation, through its effect on the final outcome of an invasion by a viral strain of a population where a very similar virus is endemic. Similar viral strains are modelled by the same infection and reinfection parameters, and by a given degree of cross immunity that represents the antigenic distance between the competing strains. We have found, somewhat surprisingly, that clustering on the network decreases the potential to sustain pathogen diversity.

Attention bias in earthquake-exposed survivors: an event-related potential study.

PubMed

Zhang, Yan; Kong, Fanchang; Han, Li; Najam Ul Hasan, Abbasi; Chen, Hong

2014-12-01

The Chinese Wenchuan earthquake, which happened on the 28th of May in 2008, may leave deep invisible scars in individuals. China has a large number of children and adolescents, who tend to be most vulnerable because they are in an early stage of human development and possible post-traumatic psychological distress may have a life-long consequence. Trauma survivors without post-traumatic stress disorder (PTSD) have received little attention in previous studies, especially in event-related potential (ERP) studies. We compared the attention bias to threat stimuli between the earthquake-exposed group and the control group in a masked version of the dot probe task. The target probe presented at the same space location consistent with earthquake-related words was the congruent trial, while in the space location of neutral words was the incongruent trial. Thirteen earthquake-exposed middle school students without PTSD and 13 matched controls were included in this investigation. The earthquake-exposed group showed significantly faster RTs to congruent trials than to incongruent trials. The earthquake-exposed group produced significantly shorter C1 and P1 latencies and larger C1, P1 and P2 amplitudes than the control group. In particular, enhanced P1 amplitude to threat stimuli was observed in the earthquake-exposed group. These findings are in agreement with the prediction that earthquake-exposed survivors have an attention bias to threat stimuli. The traumatic event had a much greater effect on earthquake-exposed survivors even if they showed no PTSD symptoms than individuals in the controls. These results will provide neurobiological evidences for effective intervention and prevention to post-traumatic mental problems. Copyright © 2014 Elsevier B.V. All rights reserved.

9 CFR 73.8 - Cattle infected or exposed during transit.

Code of Federal Regulations, 2013 CFR

2013-01-01

... SCABIES IN CATTLE § 73.8 Cattle infected or exposed during transit. (a) Healthy cattle from unquarantined... of Agriculture for scabies in cattle be unloaded en route and placed in infectious premises, they... with scabies or to have been exposed thereto, shall thereafter be handled in the same manner as...

9 CFR 73.8 - Cattle infected or exposed during transit.

Code of Federal Regulations, 2011 CFR

2011-01-01

... SCABIES IN CATTLE § 73.8 Cattle infected or exposed during transit. (a) Healthy cattle from unquarantined... of Agriculture for scabies in cattle be unloaded en route and placed in infectious premises, they... with scabies or to have been exposed thereto, shall thereafter be handled in the same manner as...

9 CFR 73.8 - Cattle infected or exposed during transit.

Code of Federal Regulations, 2014 CFR

2014-01-01

... SCABIES IN CATTLE § 73.8 Cattle infected or exposed during transit. (a) Healthy cattle from unquarantined... of Agriculture for scabies in cattle be unloaded en route and placed in infectious premises, they... with scabies or to have been exposed thereto, shall thereafter be handled in the same manner as...

9 CFR 73.8 - Cattle infected or exposed during transit.

Code of Federal Regulations, 2012 CFR

2012-01-01

... SCABIES IN CATTLE § 73.8 Cattle infected or exposed during transit. (a) Healthy cattle from unquarantined... of Agriculture for scabies in cattle be unloaded en route and placed in infectious premises, they... with scabies or to have been exposed thereto, shall thereafter be handled in the same manner as...

Color vision impairments among shipyard workers exposed to mixed organic solvents, especially xylene.

PubMed

Lee, Eun-Hee; Paek, Domyung; Kho, Young Lim; Choi, Kyungho; Chae, Hong Jae

2013-01-01

We evaluated color vision impairment in workers exposed to organic solvents, especially xylene. Three groups of subjects, comprising 63 workers occupationally exposed to organic solvents, 122 non-exposed workers in the same industry, and 185 subjects from the general population as controls, were evaluated for color vision. Exposure to solvents was indirectly evaluated by measuring the concentration of a urinary metabolite. Color vision was assessed using the Lanthony Desaturated 15-hue (Lanthony D-15) panel. Color confusion index (CCI) values in the exposed group were significantly higher than in the non-exposed workers or the general population, after adjustment for age and education, and significantly correlated with the concentration of methylhippuric acid. Color vision impairments were detected more frequently among the exposed group, and the most common types were type III and complex impairments. The rate of type III impairments was 9.52% in the exposed group, 1.64% in the non-exposed group, and 1.62% in the general population. Our results support the hypothesis that acquired color vision impairments could be induced by exposure to xylene. Testing for color vision impairment is a relatively simple, non-invasive and sensitive diagnostic method for relatively low-level exposures to xylene. Copyright © 2013 Elsevier Inc. All rights reserved.

[Mesenteric cyst in the Instituto Nacional de Salud del Niño, Lima, Peru: a case report].

PubMed

Cucho, Janetliz; Ormeño, Alexis; Valdivieso Falcon, Lidia; Pereyra, Sonia; Ramos Rodríguez, Karen

2013-01-01

Mesenteric cysts are rare abdominal tumors. About 60% of these cysts occurs before 5 years of age and can be located anywhere in the gastrointestinal tract, but are most often found in the small bowel mesentery. The clinical presentation depends on the location and size of the cyst and many cases are asymptomatic and are diagnosed incidentally. The most common symptoms are abdominal pain, bloating, abdominal mass, nausea, vomiting, constipation, diarrhea, weight loss, fever and peritonitis. Complications include torsion, infarction, volvulus formation, perforation, infection, anemia, intracystic hemorrhage, intestinal obstruction and obstructive uropathy. They are typically treated by simple excision, marsupialization or segmental bowel resection and have excellent long-term prognosis.

Could high salinity be used to control bullfrogs in small ponds?

USGS Publications Warehouse

Ward, David L.; Finch, Colton; Blasius, Heidi

2015-01-01

We examined survival of bullfrog (Rana catesbeiana) eggs and tadpoles at 3 ppt and 6 ppt salinity in the laboratory to determine if low-level salinity could be used to eradicate bullfrogs from small ponds that contain native fishes. Bullfrog eggs and tadpoles <10 days old experienced 100% mortality when held at 6 ppt salinity for 10 days. Bullfrog tadpoles 10–15 days old experienced significantly reduced survival when exposed to salinity of 6 ppt for 10 days. Older bullfrog tadpoles (>9 months old) appeared unaffected by 14 days of 6 ppt salinity. Salinity of 3 ppt did not impact survival of bullfrog tadpole eggs or tadpoles at any of the life stages we tested. Adding salt to ponds in the early spring to increase salinity to 6 ppt may be a cost effective way to eradicate bullfrogs from small ponds without harming native fishes.

Technical Nuances of Exposing Rat Common Carotid Arteries for Practicing Microsurgical Anastomosis.

PubMed

Tayebi Meybodi, Ali; Aklinski, Joseph; Gandhi, Sirin; Lawton, Michael T; Preul, Mark C

2018-04-17

Animal models are commonly used in training protocols for microsurgical vascular anastomosis. Rat common carotid arteries (CCAs) are frequently used for this purpose. Much attention has been paid to the technical details of various anastomosis configurations using these arteries. However, technical nuances of exposing rat CCAs have been understudied. The purpose of this study is to describe nuances of technique for safely and efficiently exposing rat CCAs in preparation for a vascular anastomosis. Bilateral CCAs were exposed and prepared for anastomosis in 10 anesthetized Sprague-Dawley rats through a midline cervical incision. The exposed length of the CCA was measured. Additionally, technical nuances of exposure and surgically relevant anatomic details were recorded. The CCAs were exposed from the sternoclavicular joint to their bifurcation (average length, 19.1 ± 2.8 mm). Tenets important for a safe and efficient exposure of the CCAs included 1) generous subcutaneous dissection to expose the external jugular veins (EJVs), 2) avoiding injury to or compression of the EJVs, 3) superior mobilization of the salivary glands, 4) division of internal jugular veins, 5) opening the carotid sheath at its midlevel and from medial to lateral, and 6) avoiding injury to the vagus nerve or sympathetic trunk. Using the principles introduced in this study, trainees may safely and efficiently expose rat CCAs in preparation for a bypass. Copyright © 2018 Elsevier Inc. All rights reserved.

Artificial light pollution: Shifting spectral wavelengths to mitigate physiological and health consequences in a nocturnal marsupial mammal.

PubMed

Dimovski, Alicia M; Robert, Kylie A

2018-05-02

The focus of sustainable lighting tends to be on reduced CO 2 emissions and cost savings, but not on the wider environmental effects. Ironically, the introduction of energy-efficient lighting, such as light emitting diodes (LEDs), may be having a great impact on the health of wildlife. These white LEDs are generated with a high content of short-wavelength 'blue' light. While light of any kind can suppress melatonin and the physiological processes it regulates, these short wavelengths are potent suppressors of melatonin. Here, we manipulated the spectral composition of LED lights and tested their capacity to mitigate the physiological and health consequences associated with their use. We experimentally investigated the impact of white LEDs (peak wavelength 448 nm; mean irradiance 2.87 W/m 2 ), long-wavelength shifted amber LEDs (peak wavelength 605 nm; mean irradiance 2.00 W/m 2 ), and no lighting (irradiance from sky glow < 0.37 × 10 -3 W/m 2 ), on melatonin production, lipid peroxidation, and circulating antioxidant capacity in the tammar wallaby (Macropus eugenii). Night-time melatonin and oxidative status were determined at baseline and again following 10 weeks exposure to light treatments. White LED exposed wallabies had significantly suppressed nocturnal melatonin compared to no light and amber LED exposed wallabies, while there was no difference in lipid peroxidation. Antioxidant capacity declined from baseline to week 10 under all treatments. These results provide further evidence that short-wavelength light at night is a potent suppressor of nocturnal melatonin. Importantly, we also illustrate that shifting the spectral output to longer wavelengths could mitigate these negative physiological impacts. © 2018 Wiley Periodicals, Inc.

RIBE at an inter-organismic level: A study on genotoxic effects in Daphnia magna exposed to waterborne uranium and a uranium mine effluent.

PubMed

Reis, P; Lourenço, J; Carvalho, F P; Oliveira, J; Malta, M; Mendo, S; Pereira, R

2018-05-01

The induction of RIBE (Radiation Induced Bystander Effect) is a non-target effect of low radiation doses that has already been verified at an inter-organismic level in fish and small mammals. Although the theoretical impact in the field of environmental risk assessment (ERA) is possible, there is a gap of knowledge regarding this phenomenon in invertebrate groups and following environmentally relevant exposures. To understand if RIBE should be considered for ERA of radionuclide-rich wastewaters, we exposed Daphnia magna (<24 h and 5d old) to a 2% diluted uranium mine effluent for 48 h, and to a matching dose of waterborne uranium (55.3 μg L -1 ). Then the exposed organisms were placed (24 and 48 h) in a clean medium together with non-exposed neonates. The DNA damage observed for the non-exposed organisms was statistically significant after the 24 h cohabitation for both uranium (neonates p = 0.002; 5 d-old daphnids p = <0.001) and uranium mine effluent exposure (only for neonates p = 0.042). After 48 h cohabitation significant results were obtained only for uranium exposure (neonates p = 0.017; 5 d-old daphnids p = 0.013). Although there may be some variability associated to age and exposure duration, the significant DNA damage detected in non-exposed organisms clearly reveals the occurrence of RIBE in D. magna. The data obtained and here presented are a valuable contribution for the discussion about the relevance of RIBE for environmental risk assessment. Copyright © 2018 Elsevier B.V. All rights reserved.

Systemic complications of trinitrotoluene (TNT) in exposed workers.

PubMed

Naderi, Mostafa; Ghanei, Mostafa; Shohrati, Majid; Saburi, Amin; Babaei, Mahmoud; Najafian, Bita

2013-03-01

2,4,6-trinitrotoluene (TNT) has been widely used as an explosive. TNT can induce some well-recognized toxic impacts comprising toxic hepatitis, aplastic anemia and cataract. The aim of study was evaluation of TNT exposed workers for systemic complication. In a cross-sectional study, we carried out Liver Function Test (LFT), complete blood count (CBC) and slit lamp biomicroscopy to compare the prevalence and severity of these 3 complications between 47 male TNT exposed workers (with at least one year continuous experience of TNT exposure) and 43 unexposed male hospital worker who hadn't had any previous contacts with TNT. We also performed Pulmonary Function Test (PFT) to assess the probable obstructive/restrictive abnormalities, caused by TNT. Mean alkaline phosphatase (ALP) level of TNT exposed group was significantly higher than the unexposed group (p = 0.023) Forced Expiratory Volume in one second to Forced Vital Capacity (FEV1/FVC) ratios of both groups were in the range of restrictive pattern (82.03% and 81.42% for the exposed and unexposed group, respectively) with no meaningful difference. We didn't find out any specific TNT induced cataract and general cortical cataract (CC) and nuclear sclerotic cataract (NSC) prevalence was not significantly different. we haven't found TNT as a chemical, causing toxic hepatitis or aplastic anemia; neither did we find it as a compound, responsible for a meaningful increase in cataract prevalence. However, due to the increased ALP serum levels and FEV1/FVC ratios among TNT workers, safety precautions are advised.

Nine-year mortality experience in proton-exposed Macaca mulatta

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krupp, J.H.

1976-08-01

Macaca mulatta exposed at 2 yr of age to proton irradiation have been observed for mortality and latent effects since 1964. This report of progress covering the first 9 yr postexposure shows an interesting occurrence of neoplasia in the 55 MeV proton-exposed animals and an increased incidence of endometriosis in whole-body penetrating proton exposures. For doses of 400 rad and less, no significant deviation from control mortality is apparent, 9 yr postexposure.

Artificial light at night desynchronizes strictly seasonal reproduction in a wild mammal.

PubMed

Robert, Kylie A; Lesku, John A; Partecke, Jesko; Chambers, Brian

2015-10-07

Change in day length is an important cue for reproductive activation in seasonally breeding animals to ensure that the timing of greatest maternal investment (e.g. lactation in mammals) coincides with favourable environmental conditions (e.g. peak productivity). However, artificial light at night has the potential to interfere with the perception of such natural cues. Following a 5-year study on two populations of wild marsupial mammals exposed to different night-time levels of anthropogenic light, we show that light pollution in urban environments masks seasonal changes in ambient light cues, suppressing melatonin levels and delaying births in the tammar wallaby. These results highlight a previously unappreciated relationship linking artificial light at night with induced changes in mammalian reproductive physiology, and the potential for larger-scale impacts at the population level. © 2015 The Author(s).

Exposure to Celebrity-Endorsed Small Cigar Promotions and Susceptibility to Use among Young Adult Cigarette Smokers

PubMed Central

Sterling, Kymberle L.; Moore, Roland S.; Pitts, Nicole; Duong, Melissa; Ford, Kentya H.; Eriksen, Michael P.

2013-01-01

Small cigar smoking among young adult cigarette smokers may be attributed to their exposure to its advertisements and promotions. We examined the association between exposure to a celebrity music artist's endorsement of a specific brand of small cigars and young adult cigarette smokers' susceptibility to smoking that brand. Venue-based sampling procedures were used to select and survey a random sample of 121 young adult cigarette smokers, aged 18–35. Fourteen percent reported exposure to the artist's endorsement of the small cigar and 45.4% reported an intention to smoke the product in the future. The odds of small cigar smoking susceptibility increased threefold for those who reported exposure to the endorsement compared to those not exposed (OR = 3.64, 95% CI 1.06 to 12.54). Past 30-day small cigar use (OR = 3.30, 95% CI 1.24 to 8.74) and past 30-day cigar use (OR = 5.08, 95% CI 1.23, 21.08) were also associated with susceptibility to smoke a small cigar. An association between young adult cigarette smokers' exposure to the music artist's small cigar endorsement and their susceptibility to smoke small cigars was found. This association underscores the importance of monitoring small cigar promotions geared toward young people and their impact on small cigar product smoking. PMID:24371444

Prevalence and determinants of airflow limitation in urban and rural children exposed to cooking fuels in South-East Nigeria.

PubMed

Oguonu, Tagbo; Obumneme-Anyim, Ijeoma N; Eze, Joy N; Ayuk, Adaeze C; Okoli, Chinyere V; Ndu, Ikenna K

2018-05-01

Background Biofuels and other cooking fuels are used in households in low- and middle-income countries. Aim To investigate the impact of cooking fuels on lung function in children in urban and rural households in South-East Nigeria. Methods The multi-stage sampling method was used to enroll children exposed to cooking fuel in the communities. Lung function values FEV1, FVC and the FEV1/FVC ratio, were measured with ndd EasyOne R spirometer. Airflow limitation was determined with FEV1/FVC Z-score values at -1.64 as the lower limit of normal (LLN5). The Global Lung Function Initiative 2012 software was used to calculate the lung function indices. Results The median age (range) of the 912 children enrolled was 10.6 years (6-18). Altogether, 468 (51.6%) children lived in rural areas. Seven hundred and thirty-seven (80.7%) were directly exposed to cooking fuels (418/737, 56.5% in rural areas). Wood and kerosene were the dominant fuels in rural and urban households. The respective mean Z-scores of the exposed children in rural and urban were zFEV1 -0.62, FVC -0.21, FEV1/FVC -0.83 and zFEV1 -0.57, zFVC -0.14, FEV1/FVC -0.75. Few (5.2%, 38/737) of the children had airflow limitation. Most of them (60.5%, 25/38) lived in the rural community; the lowest FEV1/FVC Z-scores were those of exposed to a combination of fuels. Conclusion Exposure to cooking fuels affects lung function in children with airway limitation in a small proportion, Control measures are advocated to reduce the morbidity related to cooking fuels exposure.

Interviews with Children Exposed to Violence

ERIC Educational Resources Information Center

Eriksson, Maria; Nasman, Elisabet

2012-01-01

The aim of this article is to show how research practices may simultaneously follow principles of children's citizenship rights to participation and principles of protection and support when children exposed to violence are informants. The article focuses upon organisation of interview processes and interactions between adult researchers and child…

Effects of Circadian Disruption on Methamphetamine Consumption in Methamphetamine-Exposed Rats

PubMed Central

Doyle, Susan E.; Feng, Hanting; Garber, Garrett; Menaker, Michael; Lynch, Wendy J.

2015-01-01

Rationale A substantial number of clinical studies indicate associations between sleep abnormalities and drug abuse; however, the role played by the circadian system in the development of addiction is largely unknown. Objective The aim of this study was to examine the effects of experimentally induced chronic jet lag on methamphetamine consumption in a rat model of methamphetamine drinking. Methods Male Sprague-Dawley rats (n=32) were housed in running wheel cages in a 12:12 light:dark cycle. One group of rats (n=16) was given two weeks of forced methamphetamine consumption (0.01% in drinking water; meth pre-exposed) while a second group (n=16, not pre-exposed) received water only. This was followed by a two week abstinence period during which half of the animals from each group were exposed to 4 consecutive 6-hr advancing phase shifts of the light:dark cycle, while the other half remained on the original light:dark cycle. Methamphetamine consumption was assessed in all rats following the deprivation period using a two-bottle choice paradigm. Results Methamphetamine consumption was initially lower in methamphetamine pre-exposed vs. not pre-exposed rats. However, during the second week following abstinence, consumption was significantly higher in phase shifted rats of the methamphetamine pre-exposed group compared to all other groups. Conclusions These data reveal an effect of circadian rhythm disturbance on methamphetamine consumption, and suggest that dysregulation of the circadian system be considered in the etiology of relapse and addiction. PMID:25543849

Effects of circadian disruption on methamphetamine consumption in methamphetamine-exposed rats.

PubMed

Doyle, Susan E; Feng, Hanting; Garber, Garrett; Menaker, Michael; Lynch, Wendy J

2015-06-01

A substantial number of clinical studies indicate associations between sleep abnormalities and drug abuse; however, the role played by the circadian system in the development of addiction is largely unknown. The aim of this study was to examine the effects of experimentally induced chronic jet lag on methamphetamine consumption in a rat model of methamphetamine drinking. Male Sprague-Dawley rats (n = 32) were housed in running wheel cages in a 12:12 h light:dark cycle. One group of rats (n = 16) was given 2 weeks of forced methamphetamine consumption (0.01 % in drinking water; meth pre-exposed) while a second group (n = 16, not pre-exposed) received water only. This was followed by a 2-week abstinence period during which half of the animals from each group were exposed to four consecutive 6-h advancing phase shifts of the light:dark cycle, while the other half remained on the original light:dark cycle. Methamphetamine consumption was assessed in all rats following the deprivation period using a two-bottle choice paradigm. Methamphetamine consumption was initially lower in methamphetamine pre-exposed versus not pre-exposed rats. However, during the second week following abstinence, consumption was significantly higher in phase-shifted rats of the methamphetamine pre-exposed group compared to all other groups. These data reveal an effect of circadian rhythm disturbance on methamphetamine consumption and suggest that dysregulation of the circadian system be considered in the etiology of relapse and addiction.

Exposure to particles, elemental carbon and nitrogen dioxide in workers exposed to motor exhaust.

PubMed

Lewné, Marie; Plato, Nils; Gustavsson, Per

2007-11-01

The main aim of this study was to investigate the personal exposure to diesel and petrol exhaust fumes in occupations when exposure is prevalent and/or high. We also investigated the correlation between the five particle fractions [particles with an aerodynamic diameter <1 microm (PM(1)), particles with an aerodynamic diameter <2.5 microm (PM(2.5)), particles in size 0.1-10 microm, elemental carbon (EC) and total carbon (TC)] and nitrogen dioxide (NO(2)), in the various occupational environments. Seventy-one workers were included in the study. They were subdivided into seven groups depending on working area, working indoors, out of doors or in vehicles and type of exposure (diesel or petrol exhaust). Personal measurements were performed during 3 days per worker. We used five indicators of the particle fraction: PM(1), PM(2.5), particle measured with a real-time monitoring instrument for particles in sizes 0.1 and 10 microm (DataRAM), EC and TC. We used NO(2) as an indicator of the gas phase. Tunnel construction workers showed the highest levels of exposure for all indicators, followed by diesel-exposed garage workers. For the other five groups, the levels were statistically significantly lower, and the differences between the groups were small. The full-shift geometric average of PM(1) varied between 119 microg m(-3) (tunnel construction workers) and 11 microg m(-3) (taxi drivers). For PM(2.5), the levels varied between 231 microg m(-3) (tunnel construction workers) and 16 microg m(-3) (bus and lorry drivers). For the measurements with the real-time monitoring instrument DataRAM, the levels varied between 398 microg m(-3) (tunnel construction workers) and 14 microg m(-3) (taxi drivers). For EC, the levels varied between 87 microg m(-3) (tunnel construction workers) and 4 microg m(-3) (other outdoor workers exposed to diesel exhaust), and for TC, the levels varied between 191 microg m(-3) (tunnel construction workers) and 10 microg m(-3) (taxi drivers). Finally, for

Semen quality of Indian welders occupationally exposed to nickel and chromium.

PubMed

Danadevi, K; Rozati, Roya; Reddy, P P; Grover, Paramjit

2003-01-01

The semen quality of 57 workers from a welding plant in South India and 57 controls was monitored. Blood nickel and chromium concentrations were determined by ICP-MS. Analysis of semen samples was performed in accordance with World Health Organization criteria. The blood level of nickel and chromium for the 28 exposed workers was 123.3 +/- 35.2 and 131.0 +/- 52.6 microg/l, resepctively, which was significantly higher than the 16.7 +/- 5.8 and 17.4 +/- 8.9 microg/l for the control group (n=27). Sperm concentrations of exposed workers were 14.5 +/- 24.0 millions/ml and those of the control group were 62.8 +/- 43.7 millions/ml. Rapid linear sperm motility was decreased in exposed workers compared to controls. There was a significant positive correlation between the percentage of tail defects and blood nickel concentration in exposed workers. The sperm concentration showed a negative correlation with blood chromium content in workers. More abnormal characteristics were found in the semen of exposed workers. Semen abnormalities correlated with the number of years of exposure to welding fumes containing nickel and chromium.

Children Exposed in Utero to Illegal Drugs: Education's Newest Crisis.

ERIC Educational Resources Information Center

Liaison Bulletin, 1992

1992-01-01

This bulletin highlights topics addressed at a National Association of State Directors of Special Education (NASDSE) Action Seminar on Infants Exposed to Illicit Drugs and Alcohol in Utero. The incidence of babies being born exposed to cocaine and other illicit drugs is outlined, and it is concluded that numbers appear to be on the rise. The…

Analysis of emotionality and locomotion in radio-frequency electromagnetic radiation exposed rats.

PubMed

Narayanan, Sareesh Naduvil; Kumar, Raju Suresh; Paval, Jaijesh; Kedage, Vivekananda; Bhat, M Shankaranarayana; Nayak, Satheesha; Bhat, P Gopalakrishna

2013-07-01

In the current study the modulatory role of mobile phone radio-frequency electromagnetic radiation (RF-EMR) on emotionality and locomotion was evaluated in adolescent rats. Male albino Wistar rats (6-8 weeks old) were randomly assigned into the following groups having 12 animals in each group. Group I (Control): they remained in the home cage throughout the experimental period. Group II (Sham exposed): they were exposed to mobile phone in switch-off mode for 28 days, and Group III (RF-EMR exposed): they were exposed to RF-EMR (900 MHz) from an active GSM (Global system for mobile communications) mobile phone with a peak power density of 146.60 μW/cm(2) for 28 days. On 29th day, the animals were tested for emotionality and locomotion. Elevated plus maze (EPM) test revealed that, percentage of entries into the open arm, percentage of time spent on the open arm and distance travelled on the open arm were significantly reduced in the RF-EMR exposed rats. Rearing frequency and grooming frequency were also decreased in the RF-EMR exposed rats. Defecation boli count during the EPM test was more with the RF-EMR group. No statistically significant difference was found in total distance travelled, total arm entries, percentage of closed arm entries and parallelism index in the RF-EMR exposed rats compared to controls. Results indicate that mobile phone radiation could affect the emotionality of rats without affecting the general locomotion.

Assessment of central auditory processing in a group of workers exposed to solvents.

PubMed

Fuente, Adrian; McPherson, Bradley; Muñoz, Verónica; Pablo Espina, Juan

2006-12-01

Despite having normal hearing thresholds and speech recognition thresholds, results for central auditory tests were abnormal in a group of workers exposed to solvents. Workers exposed to solvents may have difficulties in everyday listening situations that are not related to a decrement in hearing thresholds. A central auditory processing disorder may underlie these difficulties. To study central auditory processing abilities in a group of workers occupationally exposed to a mix of organic solvents. Ten workers exposed to a mix of organic solvents and 10 matched non-exposed workers were studied. The test battery comprised pure-tone audiometry, tympanometry, acoustic reflex measurement, acoustic reflex decay, dichotic digit, pitch pattern sequence, masking level difference, filtered speech, random gap detection and hearing-in-noise tests. All the workers presented normal hearing thresholds and no signs of middle ear abnormalities. Workers exposed to solvents had lower results in comparison with the control group and previously reported normative data, in the majority of the tests.

Whole DNA methylome profiling in mice exposed to secondhand smoke.

PubMed

Tommasi, Stella; Zheng, Albert; Yoon, Jae-In; Li, Arthur Xuejun; Wu, Xiwei; Besaratinia, Ahmad

2012-11-01

Aberration of DNA methylation is a prime epigenetic mechanism of carcinogenesis. Aberrant DNA methylation occurs frequently in lung cancer, with exposure to secondhand smoke (SHS) being an established risk factor. The causal role of SHS in the genesis of lung cancer, however, remains elusive. To investigate whether SHS can cause aberrant DNA methylation in vivo, we have constructed the whole DNA methylome in mice exposed to SHS for a duration of 4 mo, both after the termination of exposure and at ensuing intervals post-exposure (up to 10 mo). Our genome-wide and gene-specific profiling of DNA methylation in the lung of SHS-exposed mice revealed that all groups of SHS-exposed mice and controls share a similar pattern of DNA methylation. Furthermore, the methylation status of major repetitive DNA elements, including long-interspersed nuclear elements (LINE L1), intracisternal A particle long-terminal repeat retrotransposons (IAP-LTR), and short-interspersed nuclear elements (SINE B1), in the lung of all groups of SHS-exposed mice and controls remains comparable. The absence of locus-specific gain of DNA methylation and global loss of DNA methylation in the lung of SHS-exposed mice within a timeframe that precedes neoplastic-lesion formation underscore the challenges of lung cancer biomarker development. Identifying the initiating events that cause aberrant DNA methylation in lung carcinogenesis may help improve future strategies for prevention, early detection and treatment of this highly lethal disease.

Whole DNA methylome profiling in mice exposed to secondhand smoke

PubMed Central

Tommasi, Stella; Zheng, Albert; Yoon, Jae-In; Li, Arthur Xuejun; Wu, Xiwei; Besaratinia, Ahmad

2012-01-01

Aberration of DNA methylation is a prime epigenetic mechanism of carcinogenesis. Aberrant DNA methylation occurs frequently in lung cancer, with exposure to secondhand smoke (SHS) being an established risk factor. The causal role of SHS in the genesis of lung cancer, however, remains elusive. To investigate whether SHS can cause aberrant DNA methylation in vivo, we have constructed the whole DNA methylome in mice exposed to SHS for a duration of 4 mo, both after the termination of exposure and at ensuing intervals post-exposure (up to 10 mo). Our genome-wide and gene-specific profiling of DNA methylation in the lung of SHS-exposed mice revealed that all groups of SHS-exposed mice and controls share a similar pattern of DNA methylation. Furthermore, the methylation status of major repetitive DNA elements, including long-interspersed nuclear elements (LINE L1), intracisternal A particle long-terminal repeat retrotransposons (IAP-LTR), and short-interspersed nuclear elements (SINE B1), in the lung of all groups of SHS-exposed mice and controls remains comparable. The absence of locus-specific gain of DNA methylation and global loss of DNA methylation in the lung of SHS-exposed mice within a timeframe that precedes neoplastic-lesion formation underscore the challenges of lung cancer biomarker development. Identifying the initiating events that cause aberrant DNA methylation in lung carcinogenesis may help improve future strategies for prevention, early detection and treatment of this highly lethal disease. PMID:23051858

Subchronic mild noise stress increases HRP permeability in rat small intestine in vitro.

PubMed

Bijlsma, P B; van Raaij, M T; Dobbe, C J; Timmerman, A; Kiliaan, A J; Taminiau, J A; Groot, J A

2001-05-01

Recently we reported an increased trans- and paracellular protein permeability in rat small intestine after acute cold restraint stress. In the present study, we applied randomized 95- or 105-dB white noise pulses during 45 min/h, 12 h/day, duration 8 days, as a milder, but more chronic stressor to male rats. At 8 days before the noise experiments, 50% of the animals were cannulated in the vena cava for blood sampling during the experimental period. The other 50% of the animals were sacrificed at Day 9, segments of ileum were mounted in Ussing chambers and perfused at 37 degrees C. Horseradish peroxidase (HRP) was added mucosally, serosal appearance was detected enzymatically and tissues were fixed for electron microscopy. In the animals exposed to 95-dB noise, plasma corticosterone levels were enhanced twofold compared to controls, and ileal HRP flux was enhanced twofold. Electron micrographs of tissue from stressed or control animals showed no detectable paracellular staining of HRP. Quantification of HRP-containing endosomes in enterocytes revealed a twofold increase in endosome number in the animals exposed to 95-db noise indicating that the increased HRP permeability was primarily due to increased endocytosis. In contrast to the animals exposed to 95-dB noise, rats exposed to 105-dB noise showed no increase in corticosterone levels and ileal HRP fluxes were not significantly different from controls. We conclude that mild subchronic noise stress may cause a decrease in intestinal barrier function by increased transcytosis of luminal antigens.

BIOMEX on EXPOSE-R2: First results on the preservation of Raman biosignatures after space exposure

NASA Astrophysics Data System (ADS)

Baqué, Mickael; Böttger, Ute; Leya, Thomas; de Vera, Jean-Pierre Paul

2017-04-01

After a 15-month exposure on-board the EXPOSE-R2 space platform, situated on the outside of the International Space Station, four astrobiology experiments successfully came back to Earth in March and June 2016. Among them, the BIOMEX (BIOlogy and Mars EXperiment) experiment aims at investigating the endurance of extremophiles and stability of biomolecules under space and Mars-like conditions in the presence of Martian mineral analogues (de Vera et al., 2012). The preservation and evolution of Raman biosignatures under such conditions is of particular interest for guiding future search-for-life missions to Mars (and other planetary objects) carrying Raman spectrometers (such as the Raman Laser Spectrometer instrument on board the future ExoMars rover). The photoprotective carotenoid pigments (present either in photosynthetic organisms such as plants, algae, cyanobacteria and in some bacteria and archaea) have been classified as high priority targets for biomolecule detection on Mars and therefore used as biosignature models due to their stability and easy identification by Raman spectroscopy (Böttger et al., 2012). We report here on the first results from the analysis of two carotenoids containing organisms: the cyanobacterium Nostoc sp. (strain CCCryo 231-06; = UTEX EE21 and CCMEE 391) isolated from Antarctica and the green alga cf. Sphaerocystis sp. (strain CCCryo 101-99) isolated from Spitsbergen. Desiccated cells of these organisms were exposed to space and simulated Mars-like conditions in space in the presence of two Martian mineral analogues (phyllosilicatic and sulfatic Mars regolith simulants) and a Lunar regolith analogue and analyzed with a 532nm Raman microscope at 1mW laser power. Carotenoids in both organisms were surprisingly still detectable at relatively high levels after being exposed for 15 months in Low Earth Orbit to UV, cosmic rays, vacuum (or Mars-like atmosphere) and temperatures stresses regardless of the mineral matrix used. Further

Increased leukemia-associated gene expression in benzene-exposed workers

PubMed Central

Li, Keqiu; Jing, Yaqing; Yang, Caihong; Liu, Shasha; Zhao, Yuxia; He, Xiaobo; Li, Fei; Han, Jiayi; Li, Guang

2014-01-01

Long-term exposure to benzene causes several adverse health effects, including an increased risk of acute myeloid leukemia. This study was to identify genetic alternations involved in pathogenesis of leukemia in benzene-exposed workers without clinical symptoms of leukemia. This study included 33 shoe-factory workers exposed to benzene at levels from 1 ppm to 10 ppm. These workers were divided into 3 groups based on the benzene exposure time, 1- < 7, 7- < 12, and 12- < 24 years. 17 individuals without benzene exposure history were recruited as controls. Cytogenetic analysis using Affymetrix Cytogenetics Array found copy-number variations (CNVs) in several chromosomes of benzene-exposed workers. Expression of targeted genes in these altered chromosomes, NOTCH1 and BSG, which play roles in leukemia pathogenesis, was further examined using real-time PCR. The NOTCH1 mRNA level was significantly increased in all 3 groups of workers, and the NOTCH1 mRNA level in the 12- < 24 years group was significantly higher than that in 1- < 7 and 7- < 12 years groups. Compared to the controls, the BSG mRNA level was significantly increased in 7- < 12 and 12- < 24 years groups, but not in the 1- < 7 years group. These results suggest that CNVs and leukemia-related gene expression might play roles in leukemia development in benzene-exposed workers. PMID:24993241

Redescription of Spirura guianensis (Nematoda: Spiruridae) from a rare South American Gracile Opossum.

PubMed

Torres, E J Lopes; Maldonado, A; Anjos, D H da Silva; de Souza, W; Miranda, K

2015-10-01

Spirura genus Blanchard, 1849 comprise of nematode parasites that infect primate and marsupial species. Although several taxonomical studies have shown that the infection by this species occurs primarily in the esophagus of primates, evidence for the occurrence of these parasites in other hosts (marsupials, rodents and bats) has become the subject of investigation by several groups. In this work, we describe the presence of Spirura guianensis Ortlepp, 1924 in the marsupial Gracilinanus agilis (Marsupialia: Didelphidae) found in the Pantanal of Mato Grosso do Sul state of Brazil. Structural characteristics of this nematode were identified using light microscopy (bright field and fluorescence stereomicroscopy) and scanning electron microscopy (SEM) approaches. Details of the surface topography such as cephalic projections, ventral boss, details of the caudal papillae and cuticular ornamentations were shown, providing taxonomic characteristics that may help in the establishment of diagnostic protocols. In addition, the presence of this species in a new host and new geographical area of Brazil provide grounds for a revision on the distribution of S. guianensis in South America. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparative mapping identifies the fusion point of an ancient mammalian X-autosomal rearrangement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilcox, S.A.; Watson, J.M.; Spencer, J.A.

1996-07-01

Previous comparisons of gene location in the three major groups of mammals (eutherians, marsupials, and monotremes) have suggested that the long arm of the human X represents the ancestral mammalian X chromosome, whereas the short arm represents an autosomal region(s) recently added to the eutherian X chromosome. To identify the fusion point of this ancient X-autosome rearrangement, we have mapped four genes, three of which map near the centromere of the human Xp, in marsupials and in a monotreme. We found that ARAF1, and GATA1 are located on the X chromosome in marsupials, and ALA2 and GATA1 are also locatedmore » on the X in the platypus. This implies that the proximal short arm of the human X chromosome, including the centromere, was part of the ancestral mammalian X chromosome. The fusion point between the conserved region and the recently added regions therefore maps to human Xp11.23, although gene order on the human X indicates that there has been some rearrangement of this region. 26 refs., 3 figs., 1 tab.« less

[Reliability and validity of a generic job exposure matrix applied on a small-business].

PubMed

Haro-García, Luis; Celis-Quintal, Germán; López-Rojas, Pablo; Sánchez-Román, Francisco Raúl; Juárez-Pérez, Cuauhtémoc Arturo

2007-01-01

to evaluate the reliability and validity of a generic job exposure matrix (JEM) applied in a small business. procedures to evaluate a JEM integrated by six sections: the number of exposed workers per area, frequency of exposure, time of exposure time, level of exposure, safety controls, and proximity to source of exposure, was evaluated. The JEM also obtains information about possible health effects from exposure to occupational/environment agents. Two observers estimated the risk of exposure to epoxy resins on 31 workers of an epoxy resin facility in Mexico City. The rater agreements between the two observers were assessed through percent agreement (PA), weighted kappa (kappa(w)) and the intraclass correlation coefficient (ICC). disagreements were greater for the number of exposed workers (PA = 61.3, kappa(w) = 0.24, ICC = 0.33), level of exposure (PA= 66.7, kappa(w) = 0.25, ICC= 0.56), and safety controls (PA = 54.8, kappa(w) = 0.23, ICC = 0.69) sections. Percent agreement and kappa(w) were 64% and 0.58, respectively. In accordance with Landis and Koch, Altman, Fleiss, and Byrt classifications for the interpretation of kappa value, the weighted kappa (0.58) ranged from moderate to a fair good level. despite the discordance in some sections, the JEM proved to be useful to identify the risk of exposure in this type of small business.

Magnetic Remanence and Anisotropy of Magnetic Susceptibility of Dikes From Super-Fast Spread Crust Exposed At Pito Deep Rift

NASA Astrophysics Data System (ADS)

Horst, A.; Varga, R. J.; Gee, J. S.; Karson, J. A.

2006-12-01

The tectonic window at the Pito Deep Rift exposes super-fast spread (>140mm/yr) oceanic crust created at the East Pacific Rise (EPR). Observations and investigations of well-exposed cross sections into modern ocean crust, such as Pito Deep, provide essential insights into ridge crest dynamics. Paleomagnetic analysis provides a quantitative means for assessing both magnitude and style of structural rotations of oceanic crust. The Pito Cruise 2005 collected 69 fully oriented samples [67 dikes, 2 gabbros] during several ALVIN and JASON II dives. These samples were all oriented in situ using the Geocompass. Along the escarpment of Pito Deep, dike orientations have consistant NE strikes and SE dips. These dikes are all formed roughly 3 million years ago at the EPR located to the west of their present position. We determined magnetic remanence for a subset of 34 oriented blocks. A majority of dikes in this subset have normal polarity and many are clockwise rotated from expected orientations. To assess possible orientation errors during collection, we sampled multiple dikes from relatively small areas. On ALVIN dive 4081, for example, we collected 14 samples from a well-exposed, subparallel series of dikes. These dikes provide stable and consistently oriented remanence directions suggesting that errors in the collection process are small. Remanence data collected to date verify tectonic models that suggest clockwise rotation of the Easter microplate, consistent with current models. In addition to magnetic remanence, we determined the anisotropy of magnetic susceptibility (AMS) of the 34 dike samples. AMS studies have proven their utility in a wide range of geological studies and have been shown to determine flow direction within dikes in a variety of settings. In most Pito Deep samples, two of three AMS eigenvectors lie close to dike plane orientations. Kmin generally lies perpendicular to dike planes while, in most samples, Kmax is shallow indicating dominantly

Quantitating Organoleptic Volatile Phenols in Smoke-Exposed Vitis vinifera Berries.

PubMed

Noestheden, Matthew; Thiessen, Katelyn; Dennis, Eric G; Tiet, Ben; Zandberg, Wesley F

2017-09-27

Accurate methods for quantitating volatile phenols (i.e., guaiacol, syringol, 4-ethylphenol, etc.) in smoke-exposed Vitis vinifera berries prior to fermentation are needed to predict the likelihood of perceptible smoke taint following vinification. Reported here is a complete, cross-validated analytical workflow to accurately quantitate free and glycosidically bound volatile phenols in smoke-exposed berries using liquid-liquid extraction, acid-mediated hydrolysis, and gas chromatography-tandem mass spectrometry. The reported workflow addresses critical gaps in existing methods for volatile phenols that impact quantitative accuracy, most notably the effect of injection port temperature and the variability in acid-mediated hydrolytic procedures currently used. Addressing these deficiencies will help the wine industry make accurate, informed decisions when producing wines from smoke-exposed berries.

Electrophoresis pattern of serum from mice exposed to different concentrations of sulfur dioxide

NASA Technical Reports Server (NTRS)

Singh, J.

1977-01-01

Three day old mice were continuously exposed to sulphur dioxide concentrations at 0ppm, 0.05ppm, 0.15ppm and 1ppm for eight weeks. At the end of the experiment, blood samples were collected and centrifuged for electrophoresis studies of the serum in 5 percent acrylamide gel. The length of bands of different serum proteins from the SO2 exposed mice was at a variance as compared with the length of bands from the control exposed mice and alpha-1 band seems to be missing from the serum of SO2 exposed mice.

Increased oxidative stress in preschool children exposed to passive smoking.

PubMed

Yıldırım, Faruk; Sermetow, Kabil; Aycicek, Ali; Kocyigit, Abdurrahim; Erel, Ozcan

2011-01-01

To study the effect of passive cigarette smoking on plasma oxidative and antioxidative status in passive smoking preschool children and to compare them with controls. Thirty-four passive smoking (five to 50 cigarettes per day) preschool children (study group) and 32 controls who had never been exposed to cigarette smoke were randomly chosen from children aged from 4 to 6 years. Urinary cotinine and plasma indicators of oxidative and antioxidative status, i.e., total oxidant status (TOS), total antioxidant capacity (TAC), and oxidative stress index (OSI), were determined. Mean environmental cigarette consumption was 22±13 cigarettes per day in passive smoking children. Mean urinary cotinine levels were 77.6±41.4 ng/mL and 11.9±2.3 ng/mL in the study and control groups, respectively (p < 0.001). Mean plasma TAC levels were 0.95±0.13 mmol Trolox equivalent/L and 1.01±0.09 mmol Trolox equivalent/L, respectively (p = 0.039). Mean plasma TOS levels were 28.6±7.9 µmol H2O2 equivalent/L and 18.5±6.3 µmol H2O2 equivalent/L, respectively (p < 0.001). Mean OSI levels were 3.08±0.98 arbitrary units and 1.84±0.64 arbitrary units, respectively (p < 0.001). A small amount of cigarette smoke (five to 10 cigarettes per day) causes considerable oxidative stress. There were significant correlations between number of cigarettes consumed and oxidant status and OSI levels. Passive smoke is a potent oxidant in preschool children. Its deleterious effects are not limited just to heavy passive smoking, but also occur with exposure to small amounts of smoke.

Blood and small intestine cell kinetics under radiation exposures: Mathematical modeling

NASA Astrophysics Data System (ADS)

Smirnova, Olga

Biophysical models, which describe the dynamics of vital body systems (namely, hematopoiesis and small intestinal epithelium) in mammals exposed to acute and chronic radiation, are developed. These models, based on conventional biological theories, are realized as the systems of nonlinear differential equations. Their variables and constant parameters have real biological meaning, that provides successful identification and verification of the models in hand. The explanation of a number of radiobiological effects, including those of the low-level long-term exposures, is proposed proceeding from the modeling results. It is proved that the predictions the models agree with the respective experimental data at both qualitative and quantitative levels. All this testifies to the efficiency of employment of the developed models in investigation and prediction of radiation effects on the hematopoietic and small intestinal epithelium systems, that can be used for the radiation risk assessment in the long-term space missions such as lunar colony and Mars voyage.

Psychosomatic symptoms among Palestinian nurses exposed to workplace aggression.

PubMed

Jaradat, Yousef; Nielsen, Morten Birkeland; Bast-Pettersen, Rita

2018-06-01

The study examined associations between workplace aggression (WPA) and psychosomatic symptoms in Palestinian nurses. The 341 nurses, (62% females and 38% males), answered a WHO questionnaire and a psychosomatic symptoms checklist. A total of 27.3% of the nurses reported exposure to WPA of any kind within the last 12 months. After adjusting for covariates, female nurses exposed to WPA of any kind and those exposed to verbal aggression reported a higher symptom score: (1.5; 95% confidence interval [CI]: 0.3, 2.7), and (1.4; 95%CI 0.2, 2.6), respectively, than unexposed females. Male nurses exposed to bullying reported a higher symptom score: (3.2; 95%CI 1.0, 5.5) than unexposed males. Exposure to WPA was associated with higher occurrences of psychosomatic symptoms for both sexes. The female nurses reacted most strongly to verbal aggression or to WPA of any type, while bullying was associated with the male nurses' symptoms. © 2018 Wiley Periodicals, Inc.

Increased gluconeogenesis in rats exposed to hyper-G stress

NASA Technical Reports Server (NTRS)

Daligcon, B. C.; Oyama, J.; Hannak, K.

1985-01-01

The effect of glucogenesis on the plasma glucose and liver glycogen of rats exposed to hyper-G stress is investigated. Twelve male Sprague-Dawley rats are injected with C-14 lactate, alanine, of glycerol, and six of the rats are exposed to 3.1 G for 0.25, 0.50, and 1.0 hr. The plasma glucose and liver glycogen of the centrifuged and noncentrifuged rats are analyzed. A significant increase in the C-14 incorporation of the substrate into the plasma glucose and liver glycogen is observed in the centrifuged rats. The injection of 5-methoxyindole-2-carboxylic acid, a gluconeogenesis inhibitor, results in a blocked increase in plasma glucose and liver glycogen. The role of epinephrine on the hyperglycemic and liver glycogen responses of centrifuged rats is studied. It is concluded that the initial increase in plasma glucose and liver glycogen in rats exposed to hyper-G stress is the result of an increased rate of gluconeogenesis.

Cytogenetic investigation of subjects professionally exposed to radiofrequency radiation.

PubMed

Maes, Annemarie; Van Gorp, Urbain; Verschaeve, Luc

2006-03-01

Nowadays, virtually everybody is exposed to radiofrequency radiation (RFR) from mobile phone base station antennas or other sources. At least according to some scientists, this exposure can have detrimental health effects. We investigated cytogenetic effects in peripheral blood lymphocytes from subjects who were professionally exposed to mobile phone electromagnetic fields in an attempt to demonstrate possible RFR-induced genetic effects. These subjects can be considered well suited for this purpose as their RFR exposure is 'normal' though rather high, and definitely higher than that of the 'general population'. The alkaline comet assay, sister chromatid exchange (SCE) and chromosome aberration tests revealed no evidence of RFR-induced genetic effects. Blood cells were also exposed to the well known chemical mutagen mitomycin C in order to investigate possible combined effects of RFR and the chemical. No cooperative action was found between the electromagnetic field exposure and the mutagen using either the comet assay or SCE test.

Assessing the photoaging process at sun exposed and non-exposed skin using fluorescence lifetime spectroscopy

NASA Astrophysics Data System (ADS)

Saito Nogueira, Marcelo; Kurachi, Cristina

2016-03-01

Photoaging is the skin premature aging due to exposure to ultraviolet light, which damage the collagen, elastin and can induce alterations on the skin cells DNA, and, then, it may evolve to precancerous lesions, which are widely investigated by fluorescence spectroscopy and lifetime. The fluorescence spectra and fluorescence lifetime analysis has been presented as a technique of great potential for biological tissue characterization at optical diagnostics. The main targeted fluorophores are NADH (nicotinamide adenine dinucleotide) and FAD (flavin adenine dinucleotide), which have free and bound states, each one with different average lifetimes. The average lifetimes for free and bound NADH and FAD change according to tissue metabolic alterations and may contribute to a non-invasive clinical investigation of injuries such as skin lesions. These lesions and the possible areas where they may develop can be interrogated using fluorescence lifetime spectroscopy taking into account the variability of skin phototypes and the changes related to melanin, collagen and elastin, endogenous fluorophores which have emissions that spectrally overlap to the NADH and FAD emission. The objective of this study is to assess the variation on fluorescence lifetimes of normal skin at sun exposed and non-exposed areas and associate this variation to the photoaging process.

Transcriptomic responses of germinating Bacillus subtilis spores exposed to 1.5 years of space and simulated martian conditions on the EXPOSE-E experiment PROTECT.

PubMed

Nicholson, Wayne L; Moeller, Ralf; Horneck, Gerda

2012-05-01

Because of their ubiquity and resistance to spacecraft decontamination, bacterial spores are considered likely potential forward contaminants on robotic missions to Mars. Thus, it is important to understand their global responses to long-term exposure to space or martian environments. As part of the PROTECT experiment, spores of B. subtilis 168 were exposed to real space conditions and to simulated martian conditions for 559 days in low-Earth orbit mounted on the EXPOSE-E exposure platform outside the European Columbus module on the International Space Station. Upon return, spores were germinated, total RNA extracted, fluorescently labeled, and used to probe a custom Bacillus subtilis microarray to identify genes preferentially activated or repressed relative to ground control spores. Increased transcript levels were detected for a number of stress-related regulons responding to DNA damage (SOS response, SPβ prophage induction), protein damage (CtsR/Clp system), oxidative stress (PerR regulon), and cell envelope stress (SigV regulon). Spores exposed to space demonstrated a much broader and more severe stress response than spores exposed to simulated martian conditions. The results are discussed in the context of planetary protection for a hypothetical journey of potential forward contaminant spores from Earth to Mars and their subsequent residence on Mars.

Occurrence and molecular characterization of hemoplasmas in domestic dogs and wild mammals in a Brazilian wetland.

PubMed

de Sousa, Keyla Carstens Marques; Herrera, Heitor Miraglia; Secato, Caroline Tostes; Oliveira, André do Vale; Santos, Filipe Martins; Rocha, Fabiana Lopes; Barreto, Wanessa Teixeira Gomes; Macedo, Gabriel Carvalho; de Andrade Pinto, Pedro Cordeiro Estrela; Machado, Rosangela Zacarias; Costa, Mirela Tinucci; André, Marcos Rogério

2017-07-01

Hemotropic mycoplasmas are known to cause anemia in several mammalian species. The present work aimed to investigate the occurrence of Mycoplasma spp. in wild mammals, domestic dogs and their respective ectoparasites, in southern Pantanal region, central-western Brazil. Between August 2013 and March 2015, 31 Nasua nasua, 78 Cerdocyon thous, seven Leopardus pardalis, 42 dogs, 110 wild rodents, and 30 marsupials were trapped and ectoparasites (ticks and fleas) found parasitizing the animals were collected. Mammals and ectoparasites DNA samples were submitted to conventional PCR assays for Mycoplasma spp. targeting 16S rRNA and RnaseP genes. Twenty-four N. nasua, three C. thous, two domestic dogs, one L. pardalis and one wild rodent were positive for 16S rRNA PCR protocols. Fourteen N. nasua samples were also positive in RnaseP PCR. No marsupial or arthropod showed positivity for Mycoplasma spp. The phylogenetic analyses based on 16S rRNA gene showed that all sequences obtained from dogs, two sequences obtained from C. thous and ten sequences obtained from N. nasua showed to be closely related to Mycoplasma haemocanis/Mycoplasma haemofelis species. Genotypes closely related to 'Candidatus Mycoplasma haemominutum' and Mycoplasma haemomuris were detected in the L. pardalis and in the wild rodent, respectively. Probably a novel Mycoplasma genotype, closely related to a sequence obtained from a Brazilian capybara was detected in 14 N. nasua, based on a concatenated phylogenetic analysis of 16S rRNA and RnaseP genes. The present study revealed that wild animals in southern Pantanal region, Brazil, are exposed to different species of hemoplasmas. Copyright © 2017 Elsevier B.V. All rights reserved.

Increased lung function decline in blue-collar workers exposed to welding fumes.

PubMed

Thaon, Isabelle; Demange, Valérie; Herin, Fabrice; Touranchet, Annie; Paris, Christophe

2012-07-01

There is no consensus at the present time about the effect of welding on lung function decline. This study compared lung function decline between blue-collar workers exposed and not exposed to welding fumes in a French longitudinal cohort of 21,238 subjects aged 37 to 52 years at inclusion. Medical data, occupation, sector of activity, and spirometry were recorded twice by occupational physicians in 1990 and 1995. A job-exposure matrix was used to identify 503 male blue-collar workers exposed to welding fumes and 709 control subjects and to define the weekly duration of exposure to welding fumes. Baseline lung function parameters were higher in workers exposed to welding fumes than in control subjects. After a 5-year follow-up, welding-fume exposure was associated with a nonsignificant decline in FVC (P = .06) and FEV(1) (P = .07) after adjustment for age, pack-years, BMI, and baseline value of the parameter. A significant accelerated decline in FEV(1) (P = .046) was also observed in never smokers exposed to welding fumes. An “exposure-response” relationship was observed between FEV(1) decline and weekly duration of exposure to welding fumes in nonsmokers but not in smokers. Blue-collar workers exposed to welding fumes showed accelerated decline in lung function, which, in nonsmokers, was related to weekly duration of exposure.

Small Molecules Affect Human Dental Pulp Stem Cell Properties Via Multiple Signaling Pathways

PubMed Central

Al-Habib, Mey; Yu, Zongdong

2013-01-01

One fundamental issue regarding stem cells for regenerative medicine is the maintenance of stem cell stemness. The purpose of the study was to test whether small molecules can enhance stem cell properties of mesenchymal stem cells (MSCs) derived from human dental pulp (hDPSCs), which have potential for multiple clinical applications. We identified the effects of small molecules (Pluripotin (SC1), 6-bromoindirubin-3-oxime and rapamycin) on the maintenance of hDPSC properties in vitro and the mechanisms involved in exerting the effects. Primary cultures of hDPSCs were exposed to optimal concentrations of these small molecules. Treated hDPSCs were analyzed for their proliferation, the expression levels of pluripotent and MSC markers, differentiation capacities, and intracellular signaling activations. We found that small molecule treatments decreased cell proliferation and increased the expression of STRO-1, NANOG, OCT4, and SOX2, while diminishing cell differentiation into odonto/osteogenic, adipogenic, and neurogenic lineages in vitro. These effects involved Ras-GAP-, ERK1/2-, and mTOR-signaling pathways, which may preserve the cell self-renewal capacity, while suppressing differentiation. We conclude that small molecules appear to enhance the immature state of hDPSCs in culture, which may be used as a strategy for adult stem cell maintenance and extend their capacity for regenerative applications. PMID:23573877

Radiographic abnormalities and the risk of lung cancer among workers exposed to silica dust in Ontario.

PubMed Central

Finkelstein, M M

1995-01-01

OBJECTIVE: To determine whether workers in Ontario who had been exposed to silica dust and who have radiographic abnormalities are at increased risk of lung cancer. DESIGN: Cohort and case-control studies of rates of death from lung cancer and cancer incidence rates; data were obtained from the Ontario Silicosis Surveillance Registry. Follow-up was through linkage to the Ontario mortality and cancer registries. SETTING: Ontario. PARTICIPANTS: A total of 523 workers with radiographic abnormalities and 1568 control subjects with normal radiographic findings who had been exposed to silica dust. Matching criteria were year of birth and the requirement that the control subject have a normal radiographic finding either later than or in the same year that the radiographic abnormality was identified in the silicosis subject. OUTCOME MEASURES: Standardized mortality ratios (SMRs), standardized incidence ratios (SIRs) and odds ratios for lung cancer. RESULTS: In the cohort analysis, with the Ontario population rates as reference, the all-cause SMR was 0.96 among the workers with radiographic abnormalities and 0.51 among the control subjects. The corresponding SIRs for lung cancer were 2.49 and 0.87 (p < 0.001). In the case-control analysis the workers with silicosis were more likely than the control subjects to have been smokers, but this difference likely accounted for only a small part of the difference in the incidence of lung cancer. The relative risk of lung cancer was elevated among the workers with silicosis from the foundry, mining and nonmetallic-minerals industries; however, the number of subjects was too small for a significant difference to be detected. Among the miners exposure to radon daughters did not affect the risk of lung cancer attributable to radiographic abnormalities. CONCLUSIONS: Radiographic abnormalities suggestive of exposure to silica dust are markers for increased risk of lung cancer. Physicians might thus wish to warn their patients with silica

Thermal Degradation of Small Molecules: A Global Metabolomic Investigation.

PubMed

Fang, Mingliang; Ivanisevic, Julijana; Benton, H Paul; Johnson, Caroline H; Patti, Gary J; Hoang, Linh T; Uritboonthai, Winnie; Kurczy, Michael E; Siuzdak, Gary

2015-11-03

Thermal processes are widely used in small molecule chemical analysis and metabolomics for derivatization, vaporization, chromatography, and ionization, especially in gas chromatography mass spectrometry (GC/MS). In this study the effect of heating was examined on a set of 64 small molecule standards and, separately, on human plasma metabolite extracts. The samples, either derivatized or underivatized, were heated at three different temperatures (60, 100, and 250 °C) at different exposure times (30 s, 60 s, and 300 s). All the samples were analyzed by liquid chromatography coupled to electrospray ionization mass spectrometry (LC/MS) and the data processed by XCMS Online ( xcmsonline.scripps.edu ). The results showed that heating at an elevated temperature of 100 °C had an appreciable effect on both the underivatized and derivatized molecules, and heating at 250 °C created substantial changes in the profile. For example, over 40% of the molecular peaks were altered in the plasma metabolite analysis after heating (250 °C, 300s) with a significant formation of degradation and transformation products. The analysis of 64 small molecule standards validated the temperature-induced changes observed on the plasma metabolites, where most of the small molecules degraded at elevated temperatures even after minimal exposure times (30 s). For example, tri- and diorganophosphates (e.g., adenosine triphosphate and adenosine diphosphate) were readily degraded into a mono-organophosphate (e.g., adenosine monophosphate) during heating. Nucleosides and nucleotides (e.g., inosine and inosine monophosphate) were also found to be transformed into purine derivatives (e.g., hypoxanthine). A newly formed transformation product, oleoyl ethyl amide, was identified in both the underivatized and derivatized forms of the plasma extracts and small molecule standard mixture, and was likely generated from oleic acid. Overall these analyses show that small molecules and metabolites undergo

Color discrimination impairment in workers exposed to mercury vapor.

PubMed

Urban, Pavel; Gobba, Fabriziomaria; Nerudová, Jana; Lukás, Edgar; Cábelková, Zdena; Cikrt, Miroslav

2003-08-01

To study color discrimination impairment in workers exposed to elemental mercury (Hg) vapor. Twenty-four male workers from a chloralkali plant exposed to Hg vapor, aged 42+/-9.8 years, duration of exposure 14.7+/-9.7 years, were examined. The 8h TWA air-borne Hg concentration in workplace was 59 microg/m(3); mean Hg urinary excretion (HgU) was 20.5+/-19.3 microg/g creatinine; mean Hg urinary excretion after the administration of a chelating agent, sodium 2,3-dimercapto-1-propane-sulfonate (DMPS), was 751.9+/-648 microg/48h. Twenty-four age- and gender-matched control subjects were compared. Visual acuity, alcohol intake, smoking habits, and history of diseases or drugs potentially influencing color vision were registered. The Lanthony 15-Hue desaturated test (L-D15-d) was used to assess color vision. The results were expressed quantitatively as Bowman's Color Confusion Index (CCI), and qualitatively according to Verriest's classification of acquired dyschromatopsias. The CCI was significantly higher in the exposed group than in the control (mean CCI 1.15 versus 1.04; P=0.04). The proportion of subjects with errorless performance on the Lanthony test was significantly lower in the Hg exposed group compared to referents (52% versus 73%; P=0.035). The exposed group showed higher frequency of type III dyschromatopsias (blue-yellow confusion axis) in comparison with the control group (12.5% versus 8.3%), however, the difference did not reach statistical significance. Multiple regression did not show any significant relationship between the CCI, and age, alcohol consumption, or measures of exposure. In agreement with previous studies by Cavalleri et al. [Toxicol. Lett. 77 (1995) 351; Environ. Res. Sec. A 77 (1998) 173], the results of this study support the hypothesis that exposure to mercury vapor can induce sub-clinical color vision impairment. This effect was observed at an exposure level below the current biological limit for occupational exposure to mercury. This

Extracellular vesicles from Paracoccidioides pathogenic species transport polysaccharide and expose ligands for DC-SIGN receptors

DOE PAGES

da Silva, Roberta Peres; Heiss, Christian; Black, Ian; ...

2015-09-21

Extracellular vesicles (EVs) mediate non-conventional transport of molecules across the fungal cell wall. We aimed at describing the carbohydrate composition and surface carbohydrate epitopes of EVs isolated from the pathogenic fungi Paracoccidioides brasiliensis and P. lutzii using standard procedures. Total EV carbohydrates were ethanol-precipitated from preparations depleted of lipids and proteins, then analyzed by chemical degradation, gas chromatography-mass spectrometry, nuclear magnetic resonance and size-exclusion chromatography. EV glycosyl residues of Glc, Man, and Gal comprised most probably two major components: a high molecular mass 4,6-α-glucan and a galactofuranosylmannan, possibly an oligomer, bearing a 2-α-Manp main chain linked to β-Galf (1,3) andmore » α-Manp (1,6) end units. The results also suggested the presence of small amounts of a (1→6)- Manp polymer, (1→3)-glucan and (1→6)-glucan. Glycan microarrays allowed identification of EV surface lectin(s), while plant lectin microarray profiling revealed terminal Man and GlcNAc residues exposed at the EVs surface. Mammalian lectin microarray profiling showed that DC-SIGN receptors recognized surface carbohydrate in Paracoccidioides EVs. Our results suggest that oligosaccharides, cytoplasmic storage, and cell wall polysaccharides can be exported in fungal EVs, which also expose surface PAMPs and lectins. As a result, the role of these newly identified components in the interaction with the host remains to be unraveled.« less

Extracellular vesicles from Paracoccidioides pathogenic species transport polysaccharide and expose ligands for DC-SIGN receptors

DOE Office of Scientific and Technical Information (OSTI.GOV)

da Silva, Roberta Peres; Heiss, Christian; Black, Ian

Extracellular vesicles (EVs) mediate non-conventional transport of molecules across the fungal cell wall. We aimed at describing the carbohydrate composition and surface carbohydrate epitopes of EVs isolated from the pathogenic fungi Paracoccidioides brasiliensis and P. lutzii using standard procedures. Total EV carbohydrates were ethanol-precipitated from preparations depleted of lipids and proteins, then analyzed by chemical degradation, gas chromatography-mass spectrometry, nuclear magnetic resonance and size-exclusion chromatography. EV glycosyl residues of Glc, Man, and Gal comprised most probably two major components: a high molecular mass 4,6-α-glucan and a galactofuranosylmannan, possibly an oligomer, bearing a 2-α-Manp main chain linked to β-Galf (1,3) andmore » α-Manp (1,6) end units. The results also suggested the presence of small amounts of a (1→6)- Manp polymer, (1→3)-glucan and (1→6)-glucan. Glycan microarrays allowed identification of EV surface lectin(s), while plant lectin microarray profiling revealed terminal Man and GlcNAc residues exposed at the EVs surface. Mammalian lectin microarray profiling showed that DC-SIGN receptors recognized surface carbohydrate in Paracoccidioides EVs. Our results suggest that oligosaccharides, cytoplasmic storage, and cell wall polysaccharides can be exported in fungal EVs, which also expose surface PAMPs and lectins. As a result, the role of these newly identified components in the interaction with the host remains to be unraveled.« less

Preliminary Results from Small-Pixel CdZnTe and CdTe Arrays

NASA Technical Reports Server (NTRS)

Ramsey, B. D.; Sharma, D. P.; Meisner, J.; Austin, R. A.

1999-01-01

We have evaluated 2 small-pixel (0.75 mm) Cadmium-Zinc-Telluride arrays, and one Cadmium-Telluride array, all fabricated for MSFC by Metorex (Finland) and Baltic Science Institute (Riga, Latvia). Each array was optimized for operating temperature and collection bias. It was then exposed to Cadmium-109 and Iron-55 laboratory isotopes, to measure the energy resolution for each pixel and was then scanned with a finely-collimated x-ray beam, of width 50 micron, to examine pixel to pixel and inter-pixel charge collections efficiency. Preliminary results from these array tests will be presented.

Case Report Reconstruction of Exposed Ilium With Reverse Turnover Latissimus Dorsi Muscle Flap

PubMed Central

Hayashida, Kenji; Endo, Yoshie; Kamebuchi, Katsuhiko

2011-01-01

Objective: It is difficult to cover a large skin and soft tissue defect with exposure of the ilium. We therefore performed a new reconstruction technique, using a reverse latissimus dorsi muscle flap fed by perforating branches of only the 10th intercostal artery. Methods: A 45-year-old man had a large traumatic defect located on the hip with exposure of the iliac crest. After confirming and preserving perforating branches of the 10th intercostal artery, the latissimus dorsi muscle flap was turned over just proximal to the perforating branch, and a split-thickness skin graft was performed over the flap. Results: The skin graft took place well and there were no circulation problems. Conclusions: This flap covered a larger area on the hip than the musculocutaneous flap. Furthermore, this is easier to perform and is less invasive than a vascularized free flap. Skin and soft tissue defects that expose bones of the lumbar or hip region can be reconstructed with a local flap; however, the deficit is small for this coverage and usually there is little skin and soft tissue to cover the wound defect in the surrounding area. Thus, it is often difficult to deal with large defects. We performed a reconstruction, using a reverse latissimus dorsi flap fed by perforating branches of the 10th intercostal artery for a large skin and soft tissue defect of the hip with exposure of the iliac crest, resulting in a good outcome. This technique is thought to be useful for reconstruction when the ilium is exposed, and we report the case and surgical procedure. PMID:21559059

[Cognitive impairments in persons exposed to radiation during the period of prenatal development].

PubMed

Burtovaya, E Yu; Kantina, T E; Belova, M V; Akleyev, A V

2015-01-01

To assess the cognitive status in persons exposed to ionizing radiation in prenatal period. The study included in-utero exposed people (n = 77), and the comparison group (n = 73), which consisted of people who lived in the territories of the Chelyabinsk Oblast that were not radioactive. The following methods were used: clinical, clinical-psychological (Mini-Mental State Examination (MMSE), the WAIS test, the proverb interpretation task, neurophysiological (EEG) methods, laboratory-based methods (cholesterol, high and low-density lipoproteins, triglycerides, cortisol, melatonin), and methods of statistical data processing. The number of people with non-psychotic mental disorders with the prevalence of organic mental disorders (cognitive and asthenic) was significantly higher among in-utero exposed subjects. A neurophysiological study revealed more severe changes in the bioelectric brain activity with the presence of pathological and theta-rhythms in exposed persons. The clinical-psychological study revealed a significant decrease in the analytic/synthetic ability in exposed people and significantly lower level of the general and verbal IQ. These changes were accompanied by higher levels of cortisol and melatonin which led to the activation and tension of the adaptation mechanisms in in-utero exposed subjects.

Interaction of Al with O2 exposed Mo2BC

NASA Astrophysics Data System (ADS)

Bolvardi, Hamid; Music, Denis; Schneider, Jochen M.

2015-03-01

A Mo2BC(0 4 0) surface was exposed to O2. The gas interaction was investigated using ab initio molecular dynamics and X-ray photoelectron spectroscopy (XPS) of air exposed surfaces. The calculations suggest that the most dominating physical mechanism is dissociative O2 adsorption whereby Mosbnd O, Osbnd Mosbnd O and Mo2sbnd Csbnd O bond formation is observed. To validate these results, Mo2BC thin films were synthesized utilizing high power pulsed magnetron sputtering and air exposed surfaces were probed by XPS. MoO2 and MoO3 bond formation is observed and is consistent with here obtained ab initio data. Additionally, the interfacial interactions of O2 exposed Mo2BC(0 4 0) surface with an Al nonamer is studied with ab initio molecular dynamics to describe on the atomic scale the interaction between this surface and Al to mimic the interface present during cold forming processes of Al based alloys. The Al nonamer was disrupted and Al forms chemical bonds with oxygen contained in the O2 exposed Mo2BC(0 4 0) surface. Based on the comparison of here calculated adsorption energy with literature data, Alsbnd Al bonds are shown to be significantly weaker than the Alsbnd O bonds formed across the interface. Hence, Alsbnd Al bond rupture is expected for a mechanically loaded interface. Therefore the adhesion of a residual Al on the native oxide layer is predicted. This is consistent with experimental observations. The data presented here may also be relevant for other oxygen containing surfaces in a contact with Al or Al based alloys for example during forming operations.

Mental Health in School-Aged Children Prenatally Exposed to Alcohol and Other Substances

PubMed Central

Sandtorv, Lisbeth Beate; Hysing, Mari; Rognlid, Malin; Nilsen, Sondre Aasen; Elgen, Irene Bircow

2017-01-01

Prenatal exposure to substances can possibly influence a child’s neurodevelopment and may impact on subsequent mental health. We investigated the mental health status of school-aged children referred to a pediatric hospital with a history of prenatal exposure to alcohol or other substances. Mental health was assessed using the Strengths and Difficulties Questionnaire and compared with a reference group. A total of 105 of 128 (82%) eligible children prenatally exposed to substances participated in the study, with 48 children exposed to alcohol and 57 to other substances. Strengths and Difficulties Questionnaire subscale mean scores, total difficulties scores, and total impact scores were statistically significantly higher in the group of exposed children, compared with the reference group. In this hospital-based population of school-aged children prenatally exposed to alcohol or other substances, the exposed group had an increased risk of mental health problems, compared with the reference group. PMID:29581703

Profiles of Reactivity in Cocaine-Exposed Children

PubMed Central

Schuetze, Pamela; Molnar, Danielle S.; Eiden, Rina D.

2012-01-01

This study explored the possibility that specific, theoretically consistent profiles of reactivity could be identified in a sample of cocaine-exposed infants and whether these profiles were associated with a range of infant and/or maternal characteristics. Cluster analysis was used to identify distinct groups of infants based on physiological, behavioral and maternal reported measures of reactivity. Five replicable clusters were identified which corresponded to 1) Dysregulated/High Maternal Report Reactors, 2) Low Behavioral Reactors, 3) High Reactors, 4) Optimal Reactors and 5) Dysregulated/Low Maternal Report Reactors. These clusters were associated with differences in prenatal cocaine exposure status, birthweight, maternal depressive symptoms, and maternal negative affect during mother-infant interactions. These results support the presence of distinct reactivity profiles among high risk infants recruited on the basis of prenatal cocaine exposure and demographically similar control group infants not exposed to cocaine. PMID:23204615

Hearing parameters in noise exposed industrial workers.

PubMed

Celik, O; Yalçin, S; Oztürk, A

1998-12-01

This paper presents the results of a study carried out in a group of noise-exposed workers in a hydro-electric power plant. Thus, the main focus of the study is on 130 industrial workers who were exposed to high level of noise. The control group was consisted of 33 subjects with normal hearing. Hearing and acoustic reflex thresholds were obtained from all subjects and the results from age-matched subgroups were compared. The sensorineural hearing loss which were detected in 71 workers were bilateral, symmetrical and affected mainly frequencies of 4-6 kHz. In essence, the hearing losses were developed within the first 10 years of noise exposure and associated with slight progress in the following years. When acoustic reflex thresholds derived from the study and control groups were compared, statistically significant difference was determined only for the thresholds obtained at 4 kHz (p < 0.0005).

MORTALITY IN SMALL ANIMALS EXPOSED IN A SHOCK TUBE TO "SHARP"-RISING OVERPRESSURES OF 3-4 MSEC DURATION. Technical Progress Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richmond, D.R.; Goldizen, V.C.; Clare, V.R.

1961-06-15

A total of 661 animals was exposed to sharp''-rising overpressures of 3 to 4 msec duration using a shock tube of novel design which produced a pressure pulse similar to that obtained with high explosives. The reflected shock overpressures associated with 50% lethality were 29.0, rabbit, respectively. Other observations included the time of death in mortally wounded animals and gross pathological lesions likely to contribute to mortality. Selected data from the literature bearing upon the influence of overpressure and pulse duration on lethality were reviewed. These included pulse durations ranging from less than 1 msec to 8 sec. The criticalmore » pulse duration, that duration shorter than which the overpressures required for mortality increases sharply, was noted to depend upon animal size and to be of the order of many hundreds of microseconds to very few milliseconds for smaller'' animals and a few to many tens of milliseconds for larger'' animals. (auth)« less

Liver function in workers exposed of the cosmetics industry.

PubMed

Casale, T; Caciari, T; Rosati, M V; Biagi, M; De Sio, S; Andreozzi, G; Schifano, M P; Capozzella, A; Pimpinella, B; Tomei, G; Tomei, F

2013-01-01

The purpose of this study is to assess whether occupational exposure to substances used in the cosmetic factories may cause effects on the liver and blood counts in exposed workers. The study included 48 exposed workers and 86 unexposed controls. All workers included in the study underwent blood count, white blood count, total, direct and indirect bilirubin, transaminases, alkaline phosphatase and cholinesterase. The differences between the means and frequencies were compared using the Student's t-test and chi-square test with Yates correction and were considered significant when the p value was <0.05. The analysis of the results shows that 35.4% of workers in the cosmetics industry had liver test values above the range. We noted a statistically significant higher prevalence of GPT (p <0.05) and total bilirubin (p <0.05) in the workers of the cosmetics industry compared with the control group. The results obtained suggest that occupational exposure to low doses of substances used in the cosmetic industry is able to influence some liver parameters in occupationally exposed workers.

Environmental Health and Safety Hazards of Indigenous Small-Scale Gold Mining Using Cyanidation in the Philippines

PubMed Central

Leung, Ana Marie R.; Lu, Jinky Leilanie DP.

2016-01-01

OBJECTIVES This cross-sectional study aimed at the environmental health hazards at work and cyanide exposure of small-scale gold miners engaged in gold extraction from ores in a mining area in the Philippines. METHODS Methods consisted of structured questionnaire-guided interviews, work process observation tools, physical health assessment by medical doctors, and laboratory examination and blood cyanide determination in the blood samples of 34 indigenous small-scale gold miners from Benguet, Philippines. RESULTS The small-scale gold miners worked for a mean of 10.3 years, had a mean age of 36 years, with mean lifetime mining work hours of 18,564. All were involved in tunneling work (100%) while a considerable number were involved in mixing cyanide with the ore (44%). A considerable number were injured (35%) during the mining activity, and an alarming number (35%) had elevated blood cyanide level. The most prevalent hazard was exposure to chemicals, particularly to cyanide and nitric acid, which were usually handled with bare hands. CONCLUSION The small-scale gold miners were exposed to occupational and environmental hazards at work. PMID:27547035

Environmental Health and Safety Hazards of Indigenous Small-Scale Gold Mining Using Cyanidation in the Philippines.

PubMed

Leung, Ana Marie R; Lu, Jinky Leilanie Dp

2016-01-01

This cross-sectional study aimed at the environmental health hazards at work and cyanide exposure of small-scale gold miners engaged in gold extraction from ores in a mining area in the Philippines. Methods consisted of structured questionnaire-guided interviews, work process observation tools, physical health assessment by medical doctors, and laboratory examination and blood cyanide determination in the blood samples of 34 indigenous small-scale gold miners from Benguet, Philippines. The small-scale gold miners worked for a mean of 10.3 years, had a mean age of 36 years, with mean lifetime mining work hours of 18,564. All were involved in tunneling work (100%) while a considerable number were involved in mixing cyanide with the ore (44%). A considerable number were injured (35%) during the mining activity, and an alarming number (35%) had elevated blood cyanide level. The most prevalent hazard was exposure to chemicals, particularly to cyanide and nitric acid, which were usually handled with bare hands. The small-scale gold miners were exposed to occupational and environmental hazards at work.

30 CFR 75.521 - Lightning arresters; ungrounded and exposed power conductors and telephone wires.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Lightning arresters; ungrounded and exposed power conductors and telephone wires. 75.521 Section 75.521 Mineral Resources MINE SAFETY AND HEALTH... telephone wires. Each ungrounded, exposed power conductor and each ungrounded, exposed telephone wire that...

30 CFR 75.521 - Lightning arresters; ungrounded and exposed power conductors and telephone wires.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Lightning arresters; ungrounded and exposed power conductors and telephone wires. 75.521 Section 75.521 Mineral Resources MINE SAFETY AND HEALTH... telephone wires. Each ungrounded, exposed power conductor and each ungrounded, exposed telephone wire that...

Induction of adaptive response in human blood lymphocytes exposed to radiofrequency radiation.

PubMed

Sannino, Anna; Sarti, Maurizio; Reddy, Siddharth B; Prihoda, Thomas J; Vijayalaxmi; Scarfì, Maria Rosaria

2009-06-01

The incidence of micronuclei was evaluated to assess the induction of an adaptive response to non-ionizing radiofrequency (RF) radiation in peripheral blood lymphocytes collected from five different human volunteers. After stimulation with phytohemagglutinin for 24 h, the cells were exposed to an adaptive dose of 900 MHz RF radiation used for mobile communications (at a peak specific absorption rate of 10 W/kg) for 20 h and then challenged with a single genotoxic dose of mitomycin C (100 ng/ml) at 48 h. Lymphocytes were collected at 72 h to examine the frequency of micronuclei in cytokinesis-blocked binucleated cells. Cells collected from four donors exhibited the induction of adaptive response (i.e., responders). Lymphocytes that were pre-exposed to 900 MHz RF radiation had a significantly decreased incidence of micronuclei induced by the challenge dose of mitomycin C compared to those that were not pre-exposed to 900 MHz RF radiation. These preliminary results suggested that the adaptive response can be induced in cells exposed to non-ionizing radiation. A similar phenomenon has been reported in cells as well as in animals exposed to ionizing radiation in several earlier studies. However, induction of adaptive response was not observed in the remaining donor (i.e., non-responder). The incidence of micronuclei induced by the challenge dose of mitomycin C was not significantly different between the cells that were pre-exposed and unexposed to 900 MHz RF radiation. Thus the overall data indicated the existence of heterogeneity in the induction of an adaptive response between individuals exposed to RF radiation and showed that the less time-consuming micronucleus assay can be used to determine whether an individual is a responder or non-responder.

Cosmic Radiation Exposure of Biological Test Systems During the EXPOSE-E Mission

PubMed Central

Hajek, Michael; Bilski, Pawel; Körner, Christine; Vanhavere, Filip; Reitz, Günther

2012-01-01

Abstract In the frame of the EXPOSE-E mission on the Columbus external payload facility EuTEF on board the International Space Station, passive thermoluminescence dosimeters were applied to measure the radiation exposure of biological samples. The detectors were located either as stacks next to biological specimens to determine the depth dose distribution or beneath the sample carriers to determine the dose levels for maximum shielding. The maximum mission dose measured in the upper layer of the depth dose part of the experiment amounted to 238±10 mGy, which relates to an average dose rate of 408±16 μGy/d. In these stacks of about 8 mm height, the dose decreased by 5–12% with depth. The maximum dose measured beneath the sample carriers was 215±16 mGy, which amounts to an average dose rate of 368±27 μGy/d. These values are close to those assessed for the interior of the Columbus module and demonstrate the high shielding of the biological experiments within the EXPOSE-E facility. Besides the shielding by the EXPOSE-E hardware itself, additional shielding was experienced by the external structures adjacent to EXPOSE-E, such as EuTEF and Columbus. This led to a dose gradient over the entire exposure area, from 215±16 mGy for the lowest to 121±6 mGy for maximum shielding. Hence, the doses perceived by the biological samples inside EXPOSE-E varied by 70% (from lowest to highest dose). As a consequence of the high shielding, the biological samples were predominantly exposed to galactic cosmic heavy ions, while electrons and a significant fraction of protons of the radiation belts and solar wind did not reach the samples. Key Words: Space radiation—Dosimetry—Passive radiation detectors—Thermoluminescence—EXPOSE-E. Astrobiology 12, 387–392. PMID:22680685

A neurological evaluation of workers exposed to mixtures of organic solvents.

PubMed Central

Maizlish, N A; Fine, L J; Albers, J W; Whitehead, L; Langolf, G D

1987-01-01

Workers with long term exposure to mixtures of organic solvents below regulatory limits have been reported to experience mild, but clinically detectable, sensory or sensorimotor polyneuropathies. In conjuction with a cross sectional study of behavioural performance a clinical neurological evaluation was conducted among printers and spray painters to examine dose response relations. All 240 subjects completed an occupational history and symptom questionnaire and underwent a clinical neurological examination. On average, subjects had been employed on their current job for six years. Classification of solvent exposure for each subject was based on exposed versus non-exposed job titles and observations during an industrial hygiene walk-through or on the measured concentration of solvents in full shift personal air samples. The average full shift solvent concentration was 302 ppm for printing plant workers and 6-13 ppm for workers at other plants. Isopropanol and hexane were the major constituents. Neurological abnormalities consistent with mild polyneuropathy were found in 16% of subjects; none was clinically significant. Exposed/non-exposed comparisons showed slightly higher frequency of symptoms in the exposed subjects which was not related to solvent level. Subjects categorised as exposed during the walk- through survey also had poorer vibratory sensation measured at the foot and diminished ankle reflexes. In multiple linear regression models, however, controlling for age, sex, alcohol intake, and examiner, no significant (p less than 0.05) relation was found between solvent concentration and poor neurological function except for two point discrimination measured at the foot. This investigation has not provided evidence for dose related adverse neurological effects from exposure to moderately low levels of solvent mixtures for a relatively short duration, although this may be due to the shortness of exposure duration, the type of solvent exposure, or to selection

Attachment Status in Children Prenatally Exposed to Cocaine and Other Substances

ERIC Educational Resources Information Center

Seifer, Ronald; LaGasse, Linda L.; Lester, Barry; Bauer, Charles R.; Shankaran, Seetha; Bada, Henrietta S.; Wright, Linda L.; Smeriglio, Vincent L.; Liu, Jing

2004-01-01

Attachment status of children exposed in utero to cocaine, opiates, and other substances was examined at 18 months (n=860) and 36 months (n=732) corrected age. Children exposed to cocaine and opiates had slightly lower rates of attachment security (but not disorganization), and their insecurity was skewed toward ambivalent, rather than avoidant,…

48 CFR 970.1907 - Subcontracting with Small Business, Small Disadvantaged Business and Woman-Owned Small Business...

Code of Federal Regulations, 2010 CFR

2010-10-01

... Business, Small Disadvantaged Business and Woman-Owned Small Business Concerns. 970.1907 Section 970.1907... MANAGEMENT AND OPERATING CONTRACTS Small, Small Disadvantaged and Women-Owned Small Business Concerns 970.1907 Subcontracting with Small Business, Small Disadvantaged Business and Woman-Owned Small Business...

9 CFR 78.8 - Brucellosis exposed cattle.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Brucellosis exposed cattle. 78.8 Section 78.8 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS...

9 CFR 78.8 - Brucellosis exposed cattle.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Brucellosis exposed cattle. 78.8 Section 78.8 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS...

The persistent microbicidal effect in water exposed to the corona discharge.

PubMed

Julák, Jaroslav; Scholtz, Vladimír; Kotúčová, Soňa; Janoušková, Olga

2012-07-01

This article describes and particularly explains a new phenomenon of persistent microbicidal effect of water previously exposed to the low-temperature plasma, which cannot be attributed to the acidification only. The direct microbicidal action of plasma is well documented, being mediated by number of reactive particles with a short lifetime. However, we observed the microbicidal effect also in exposed water stored for a month, where it must be mediated by stable particles. In water and in phosphate-buffered saline, the formation of NO(x) and corresponding acids, H(2)O(2) and O(3) was confirmed after exposition to the low-temperature plasma generated in air by DC negative glow corona and positive streamer discharge. The time course of acidification, H(2)O(2) and O(3) formation were deremined. Except uncertain traces of HCN, SIFT-MS analysis of exposed liquids reveals no additional reactive compounds. The microbicidal effect persists almost unchanged during 4 weeks of storage, although O(3) completely and H(2)O(2) almost disappears. Staphylococcus epidermidis and Escherichia coli were inactivated within 10 min of incubation in exposed liquids, Candida albicans needs at least 1 h. The solutions prepared by artificial mixing of reactive compounds mimic the action of exposed water, but in lesser extent. The acid milieu is the main cause of the microbicidal effect, but the possibility of still unidentified additional compound remains open. Copyright © 2011 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

CYTOGENETIC ANALYSES OF MICE EXPOSED TO DICHLOROMETHANE

EPA Science Inventory

Chromosome damage was studied in female B6C3F1 mice exposed to dichloromethane (DCM) by subcutaneous or inhalation treatments. o increase in either the frequencies of sister chromatid exchanges (SCEs) or chromosome aberrations (CAs) in bone marrow cells was observed after a singl...

Mutagenicity of urine from individuals exposed to LPG combustion products.

PubMed

Yin, X J; Liu, J Z; Kong, X H; Chu, J H; Wang, H; Xiao, Z X

1998-09-01

The mutagenicity of urine from individuals exposed to the combustion products of liquefied petroleum gas (LPG) was detected with Salmonella typhimurium TA98 and its newly developed derivatives YG1021 (nitroreductase overproducing) and YG1024 (O-acetyltransferase overproducing). The detection showed significantly increased mutagenicity for the two YG strains and increased positive rates for all three strains in the presence of both rat liver S9 and beta-glucuronidase. Further analysis demonstrated that urine samples taken from smoking and non-smoking exposed individuals exhibited significantly higher mutagenic potency (revertants/10 microliters urine concentrate) than their corresponding controls. These results indicate that the increased urine mutagenicity is caused by the exposure to LPG combustion products or smoking. The mutagenic potency of urine samples of all exposed individuals tested with YG1024 was found to be about 7 times higher than with TA98. The difference in mutagenic potency was smaller for the same samples when comparison was made between YG1021 and TA98. This suggests that the mutagenic compounds present in the urine samples contain mainly aromatic compounds as glucuronide conjugates. Our results demonstrate that YG1024 is more sensitive than TA98 in detecting the mutagenicity of these samples. In addition, no significant difference in the mutagenic potency between the 'pure' exposed (non-smokers') and the 'pure' smokers' (unexposed) samples was found in all three tester strains. This might mean that the exposure extent of mutagens/carcinogens in LPG combustion products for exposed individuals roughly corresponds to the smoking level of smokers who smoke 20-40 cigarettes per day. Furthermore, the results also suggest that synergism might exist in the mutagenic effects of exposure to LPG combustion products and cigarette smoking.

Laser-induced fluorescence of space-exposed polyurethane

NASA Technical Reports Server (NTRS)

Hill, Ralph H., Jr.

1993-01-01

The object of this work was to utilize laser-induced fluorescence technique to characterize several samples of space-exposed polyurethane. These samples were flown on the Long Duration Exposure Facility (LDEF), which was in a shuttle-like orbit for nearly 6 years. Because of our present work to develop laser-induced-fluorescence inspection techniques for polymers, space-exposed samples and controls were lent to us for evaluation. These samples had been attached to the outer surface of LDEF; therefore, they were subjected to thermal cycling, solar ultraviolet radiation, vacuum, and atomic oxygen. It is well documented that atomic oxygen and ultraviolet exposure have detrimental effects on many polymers. This was a unique opportunity to make measurements on material that had been naturally degraded by an unusual environment. During our past work, data have come from artificially degraded samples and generally have demonstrated a correlation between laser-induced fluorescence and tensile strength or elasticity.

Bronchial dysplasia induced by radiation in miners exposed to 222Rn progeny.

PubMed Central

Michaylov, M A; Pressyanov, D S; Kalinov, K B

1995-01-01

OBJECTIVES--To investigate whether sputum cytology can be used to monitor epithelial cell changes in groups at high risk of lung cancer from exposure to radiation. METHODS--Dysplasia of bronchial cells was investigated by means of sputum cytology in a group of 434 underground miners. 100 of them were not exposed, and 334 were exposed to 222Rn progeny at cumulative exposures < 450 working level months. RESULTS--The frequency of dysplasia in the exposed group was significantly higher than that in the not exposed group (P < 0.0001), and an exposure-response relation was found. This relation was different for smokers and non-smokers. CONCLUSIONS--Possibly the frequencies of dysplasia could be used to assess past exposures of groups of miners. This approach could be applied to cases where data on radiation monitoring are not available or are very scarce. Images p82-a PMID:7757171

Application of MOSFET detectors for dosimetry in small animal radiography using short exposure times.

PubMed

De Lin, Ming; Toncheva, Greta; Nguyen, Giao; Kim, Sangroh; Anderson-Evans, Colin; Johnson, G Allan; Yoshizumi, Terry T

2008-08-01

Digital subtraction angiography (DSA) X-ray imaging for small animals can be used for functional phenotyping given its ability to capture rapid physiological changes at high spatial and temporal resolution. The higher temporal and spatial requirements for small-animal imaging drive the need for short, high-flux X-ray pulses. However, high doses of ionizing radiation can affect the physiology. The purpose of this study was to verify and apply metal oxide semiconductor field effect transistor (MOSFET) technology to dosimetry for small-animal diagnostic imaging. A tungsten anode X-ray source was used to expose a tissue-equivalent mouse phantom. Dose measurements were made on the phantom surface and interior. The MOSFETs were verified with thermoluminescence dosimeters (TLDs). Bland-Altman analysis showed that the MOSFET results agreed with the TLD results (bias, 0.0625). Using typical small animal DSA scan parameters, the dose ranged from 0.7 to 2.2 cGy. Application of the MOSFETs in the small animal environment provided two main benefits: (1) the availability of results in near real-time instead of the hours needed for TLD processes and (2) the ability to support multiple exposures with different X-ray techniques (various of kVp, mA and ms) using the same MOSFET. This MOSFET technology has proven to be a fast, reliable small animal dosimetry method for DSA imaging and is a good system for dose monitoring for serial and gene expression studies.

Application of MOSFET Detectors for Dosimetry in Small Animal Radiography Using Short Exposure Times

PubMed Central

De Lin, Ming; Toncheva, Greta; Nguyen, Giao; Kim, Sangroh; Anderson-Evans, Colin; Johnson, G. Allan; Yoshizumi, Terry T.

2008-01-01

Digital subtraction angiography (DSA) X-ray imaging for small animals can be used for functional phenotyping given its ability to capture rapid physiological changes at high spatial and temporal resolution. The higher temporal and spatial requirements for small-animal imaging drive the need for short, high-flux X-ray pulses. However, high doses of ionizing radiation can affect the physiology. The purpose of this study was to verify and apply metal oxide semiconductor field effect transistor (MOSFET) technology to dosimetry for small-animal diagnostic imaging. A tungsten anode X-ray source was used to expose a tissue-equivalent mouse phantom. Dose measurements were made on the phantom surface and interior. The MOSFETs were verified with thermoluminescence dosimeters (TLDs). Bland-Altman analysis showed that the MOSFET results agreed with the TLD results (bias, 0.0625). Using typical small animal DSA scan parameters, the dose ranged from 0.7 to 2.2 cGy. Application of the MOSFETs in the small animal environment provided two main benefits: (1) the availability of results in near real-time instead of the hours needed for TLD processes and (2) the ability to support multiple exposures with different X-ray techniques (various of kVp, mA and ms) using the same MOSFET. This MOSFET technology has proven to be a fast, reliable small animal dosimetry method for DSA imaging and is a good system for dose monitoring for serial and gene expression studies. PMID:18666818

Differential cardiac effects in rats exposed to atmospheric ...

EPA Pesticide Factsheets

The results of this study demonstrate that atmospheric smog generated from both isoprene and toluene cause cardiac effects in rats. In addition, it appears that smog from toluene is more toxic in terms of cardiac arrhythmogenicity. Smog, which is a complex mixture of particulate matter and gaseous irritants (ozone, sulfur dioxide, reactive aldehydes), as well as components which react with sunlight to form secondary pollutants, has recently been linked to increased risk of adverse cardiac responses. The components, and therefore health effects, of atmospheric smog are determined by the fuel used to generate them. In this study we examined the difference between isoprene- and toluene-generated smog in causing cardiac effects in rats and hypothesized that both atmospheres would cause cardiac electrical and functional changes in rats. Male Wistar-Kyoto rats were exposed to either atmospheric smog generated by the USEPA’s mobile reaction chamber using either isoprene or toluene, or filtered air for four hours. One day later, rats were anesthetized and left ventricular functional responses to dobutamine were measured using a Millar probe and arrhythmia sensitivity to aconitine. Baseline left ventricular pressure (LVP) was lower in toluene-exposed animals but not isoprene when compared to air. Increases in LVP with increasing doses of dobutamine were impaired only in toluene-exposed rats. Both isoprene and toluene impaired the rate of ventri

Electromagnetic immunity of implantable pacemakers exposed to wi-fi devices.

PubMed

Mattei, Eugenio; Censi, Federica; Triventi, Michele; Calcagnini, Giovanni

2014-10-01

The purpose of this study is to evaluate the potential for electromagnetic interference (EMI) and to assess the immunity level of implantable pacemakers (PM) when exposed to the radiofrequency (RF) field generated by Wi-Fi devices. Ten PM from five manufacturers, representative of what today is implanted in patients, have been tested in vitro and exposed to the signal generated by a Wi-Fi transmitter. An exposure setup that reproduces the actual IEEE 802.11b/g protocol has been designed and used during the tests. The system is able to amplify the Wi-Fi signal and transmits at power levels higher than those allowed by current international regulation. Such approach allows one to obtain, in case of no EMI, a safety margin for PM exposed to Wi-Fi signals, which otherwise cannot be derived if using commercial Wi-Fi equipment. The results of this study mitigate concerns about using Wi-Fi devices close to PM: none of the PM tested exhibit any degradation of their performance, even when exposed to RF field levels five times higher than those allowed by current international regulation (20 W EIRP). In conclusion, Wi-Fi devices do not pose risks of EMI to implantable PM. The immunity level of modern PM is much higher than the transmitting power of RF devices operating at 2.4 GHz.

Genetic Predisposition for Dermal Problems in Hexavalent Chromium Exposed Population

PubMed Central

Sharma, Priti; Bihari, Vipin; Agarwal, Sudhir K.; Goel, Sudhir K.

2012-01-01

We studied the effect of genetic susceptibility on hexavalent chromium induced dermal adversities. The health status of population was examined from the areas of Kanpur (India) having the elevated hexavalent chromium levels in groundwater. Blood samples were collected for DNA isolation to conduct polymorphic determination of genes, namely: NQO1 (C609T), hOGG1 (C1245G), GSTT1, and GSTM1 (deletion). Symptomatic exposed subjects (n = 38) were compared with asymptomatic exposed subjects (n = 108) along with asymptomatic controls (n = 148) from a non contaminated reference community. Exposed symptomatic group consisted of 36.8% subjects who were GSTM1 null genotyped as compared to asymptomatic where only 19.4% subjects were null. The exposed subjects with GSTM1 null genotype were more susceptible to dermal adversities in comparison with wild genotyped subjects (OR = 2.42; 95% CI = 1.071–5.451). Age, smoking, gender or duration of residence were not found to have any confounding effect towards this association. Association with other genes was not statistically significant, nonetheless, possible contribution by these genes cannot be ruled out. In conclusion, variation in the polymorphic status of GSTM1 gene may influence dermal outcomes among residents from Cr(VI) contaminated areas. Further studies are therefore, needed to examine these observations among different population groups. PMID:22919465

Current Mercury Exposure from Artisanal and Small-Scale Gold Mining in Bombana, Southeast Sulawesi, Indonesia-Future Significant Health Risks.

PubMed

Sakakibara, Masayuki; Sera, Koichiro

2017-02-08

The rapid expansion of the artisanal and small-scale gold mining (ASGM) industry in developing countries has marginalized the local communities in poverty, and resulted in occupational exposure to mercury via the gold extraction process. We investigated the mercury exposure of the mining workers lived inside and outside the mining area. Based on the occupations of the contributors, the hair samples were divided into three subgroups: directly exposed, indirectly exposed, and a control. A total of 81 hair samples were analyzed by particle-induced X-ray emission spectrometry. The median mercury concentration was highest in the hair from the directly exposed group (12.82 μg/g hair) (control group median: 4.8 μg/g hair, p < 0.05), and the concentrations in hair from 45 respondents exceeded the Human Biomonitoring I (HBM I) threshold limit. Mercury concentrations were also elevated in the hair from the indirectly exposed group (median 7.64 μg/g hair, p < 0.05), and concentrations in hair from 24 respondents exceeded the HBM I threshold limits. Exposure to mercury during ASGM presents health risks and is harmful for the miners; mercury is also at hazardous levels for people who live in the mining area but who are not engaged in mercury-based gold extraction.

Intratracheal Administration of Small Interfering RNA Targeting Fas Reduces Lung Ischemia-Reperfusion Injury.

PubMed

Del Sorbo, Lorenzo; Costamagna, Andrea; Muraca, Giuseppe; Rotondo, Giuseppe; Civiletti, Federica; Vizio, Barbara; Bosco, Ornella; Martin Conte, Erica L; Frati, Giacomo; Delsedime, Luisa; Lupia, Enrico; Fanelli, Vito; Ranieri, V Marco

2016-08-01

Lung ischemia-reperfusion injury is the main cause of primary graft dysfunction after lung transplantation and results in increased morbidity and mortality. Fas-mediated apoptosis is one of the pathologic mechanisms involved in the development of ischemia-reperfusion injury. We hypothesized that the inhibition of Fas gene expression in lungs by intratracheal administration of small interfering RNA could reduce lung ischemia-reperfusion injury in an ex vivo model reproducing the procedural sequence of lung transplantation. Prospective, randomized, controlled experimental study. University research laboratory. C57/BL6 mice weighing 28-30 g. Ischemia-reperfusion injury was induced in lungs isolated from mice, 48 hours after treatment with intratracheal small interfering RNA targeting Fas, control small interfering RNA, or vehicle. Isolated lungs were exposed to 6 hours of cold ischemia (4°C), followed by 2 hours of warm (37°C) reperfusion with a solution containing 10% of fresh whole blood and mechanical ventilation with constant low driving pressure. Fas gene expression was significantly silenced at the level of messenger RNA and protein after ischemia-reperfusion in lungs treated with small interfering RNA targeting Fas compared with lungs treated with control small interfering RNA or vehicle. Silencing of Fas gene expression resulted in reduced edema formation (bronchoalveolar lavage protein concentration and lung histology) and improvement in lung compliance. These effects were associated with a significant reduction of pulmonary cell apoptosis of lungs treated with small interfering RNA targeting Fas, which did not affect cytokine release and neutrophil infiltration. Fas expression silencing in the lung by small interfering RNA is effective against ischemia-reperfusion injury. This approach represents a potential innovative strategy of organ preservation before lung transplantation.

Management of Bartholin's cyst and abscess using the Word catheter: implementation, recurrence rates and costs.

PubMed

Reif, Philipp; Ulrich, Daniela; Bjelic-Radisic, Vesna; Häusler, Martin; Schnedl-Lamprecht, Elke; Tamussino, Karl

2015-07-01

Bartholin's cysts and abscesses occur in about 2% of women. None of the surgical or conservative treatment approaches have been proven to be superior. The Word catheter is an outpatient treatment option, but little is known about aspects of implementing this therapy in an office setting. The present study's focus is on recurrence rates and organizational requirements of implementing outpatient treatment of Bartholin's cyst and abscess and compares costs of Word catheter treatment and marsupialization. Between March 2013 and May 2014 30 women were included in the study. We measured time consumed for treatment and follow-up and analyzed costs using the Word catheter and marsupialization under general anesthesia. We also assessed the ease of use of the Word catheter for application and removal using a standardized visual analog scale (VAS 1-10). Word catheter treatment was successful in 26/30 cases (87%). Balloon loss before the end of the 4-week treatment period occurred in 11/26 cases with a mean residence time of 19.1 (±10.0) days. None of the patients with early catheter loss developed recurrent cyst or abscess. Recurrence occurred in 1/26 cases (3.8%). Difficulty-score of application was 2 [1-10] and of removal 1 [1], respectively. Costs were € 216 for the treatment in the clinic as compared with € 1584/€ 1282 for surgical marsupialization with a one-night stay or daycare clinic, respectively. The present study indicates that the Word catheter is an easy to handle, low cost outpatient procedure with acceptable short-term recurrence rates. Treatment costs are seven times lower than for marsupialization. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Disturbances of rod threshold forced by briefly exposed luminous lines, edges, disks and annuli

PubMed Central

Hallett, P. E.

1971-01-01

1. When the dark-adapted eye is exposed to a brief duration (2 msec) luminous line the resulting threshold disturbance is much sharper (decay constant of ca. 10 min arc) than would be expected in a system which is known to integrate the effects of light quanta over a distance of 1 deg or so. 2. When the forcing input is a pair of brief duration parallel luminous lines the threshold disturbance falls off sharply at the outsides of the pattern but on the inside a considerable spread of threshold-raising effects may occur unless the lines are sufficiently far apart. 3. The threshold disturbance due to a briefly exposed edge shows an overshoot reminiscent of `lateral inhibition'. 4. If the threshold is measured at the centre of a black disk presented in a briefly lit surround then (a) the dependence of threshold on time interval between test and surround suggests that the threshold elevation is due to a non-optical effect which is not `metacontrast'; (b) the dependence of threshold on black disk diameter is consistent with the notion that the spatial threshold disturbance is progressively sharpened as the separation of luminous edges increases. 5. If the threshold is measured at the centre of briefly exposed luminous disks of various diameters one obtains the same evidence for an `antagonistic centre-surround' system as that produced by other workers (e.g. Westheimer, 1965) for the steadily light-adapted eye. 6. The previous paper (Hallett, 1971) showed that brief illumination of the otherwise dark-adapted eye can rapidly and substantially change the extent of spatial integration. The present paper shows that brief illumination leads to substantial `inhibitory' effects. 7. Earlier approaches are reviewed: (a) the linear system signal/noise theory of the time course of threshold disturbances (Hallett, 1969b) is illustrated by the case of a small subtense flash superimposed on a large oscillatory background; (b) the spatial weighting functions of some other authors are

[Respiratory symptoms and obstructive ventilatory disorder in Tunisian woman exposed to biomass].

PubMed

Kwas, H; Rahmouni, N; Zendah, I; Ghedira, H

2017-04-01

In some Tunisian cities, especially semi-urbanized, the exposure to the smoke produced during combustion of the biomass, main source of pollution of indoor air, remains prevalent among non-smoking women. To assess the relationship between exposure to biomass smoke and the presence of obstructive ventilatory disorder in the non-smoking women in semi-urban areas of Tunisia. Cross etiological study, using a questionnaire, including 140 non-smoking women responsible for cooking and/or exposed during heating by traditional means with objective measurement of their respiratory functions. We found 81 women exposed to biomass for a period of≥20 hours-years and 59 unexposed women. Exposed women reported more respiratory symptoms namely exertional dyspnea and/or chronic cough than unexposed. Of the 140 women, 14 women have an FEV/FEV6<70% of which 13 are exposed to biomass. We found a correlation between respiratory symptoms and obstructive ventilatory disorder in exposed women. The air pollution inside the home during the traditional activities of cooking and/or heating is a respiratory risk factor for non-smoking women over the age of 30 years. Exposure to biomass smoke can cause chronic respiratory symptoms and persistent obstructive ventilatory disorder that can consistent with COPD. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Ethylene thiourea: thyroid function in two groups of exposed workers.

PubMed Central

Smith, D M

1984-01-01

Ethylene thiourea is manufactured at one factory in the United Kingdom and is mixed into masterbatch rubber at another. Clinical examinations and thyroid function tests were carried out over a period of three years on eight process workers and five mixers and on matched controls. The results show that the exposed mixers, but not exposed process workers, have significantly lower levels of total thyroxine (T4) than the controls. One mixer had an appreciably raised level of thyroid stimulation hormone (TSH). PMID:6743584

Ethylene thiourea: thyroid function in two groups of exposed workers.

PubMed

Smith, D M

1984-08-01

Ethylene thiourea is manufactured at one factory in the United Kingdom and is mixed into masterbatch rubber at another. Clinical examinations and thyroid function tests were carried out over a period of three years on eight process workers and five mixers and on matched controls. The results show that the exposed mixers, but not exposed process workers, have significantly lower levels of total thyroxine (T4) than the controls. One mixer had an appreciably raised level of thyroid stimulation hormone (TSH).

DNA damage in children exposed to secondhand cigarette smoke and its association with oxidative stress.

PubMed

Shermatov, Kabil; Zeyrek, Dost; Yildirim, Faruk; Kilic, Mehmet; Cebi, Nazime; Kocyigit, Abdurrahim

2012-12-01

To compare oxidative status, total antioxidant capacity and values of DNA damage in peripheral blood lymphocytes in children exposed to secondhand cigarette smoke with healthy controls. Analytical, Observational. 54 children without any chronic diseases, attending the healthy child monitoring polyclinic. These comprised 27 children who had been exposed to passive cigarette smoke and 27 children who had not been exposed to cigarette smoke. Urine cotinine levels by the chemiluminescent technique; DNA damage by alkaline comet assay; and total oxidant status (TOS) using a novel automated measurement method. The mean urine cotinine, TOS, Oxidative Stress Index (OSI) and DNA damage values of the group exposed to cigarette smoke were determined to be at significantly higher level compared to the group not exposed to cigarette smoke (P<0.001). No statistically significant difference was determined in the TAS level between the two groups (P=0.1) The results showed that TOS levels, OSI index and DNA damage in peripheral blood lymphocytes were significantly higher in children exposed to secondhand cigarette smoke than in those not exposed to secondhand cigarette smoke.

Population structure and life history of Hemimysis lamornae mediterranea (Malacostraca: Mysida) in the Ebro Delta (NW Mediterranean)

NASA Astrophysics Data System (ADS)

Delgado, L.; Guerao, G.; Vicente, C. San; Ribera, C.

2013-10-01

Hemimysis lamornae mediterraneaBacescu, 1936 has been recently reported in the Ebro Delta (Spain, NW Mediterranean). Little is known about the biology and ecology of this mysid and we provide the first information about its population biology. H. l. mediterranea were collected from Sant Carles de la Ràpita harbor from June 2010 to March 2012 at night. The H. l. mediterranea population was composed of two main individual size categories: larger-sized winter/spring individuals and smaller-sized spring/summer individuals. The overall sex ratio is highly skewed; mature females are 2.5 times more abundant than mature males. Reproductive activity was higher during late winter and spring but was almost continuous throughout the year. The intra-marsupial development and growth of juveniles has been studied in the laboratory. The mean duration of incubation period (intra-marsupial stages) in laboratory conditions was 11 days (20 °C) and the age at first maturity ranged from14 to 20 days. The growth rate was faster in early juveniles and declined with age, showing a maximum of 0.152 mm d- 1. The laboratory results and demographic data suggest that H. l. mediterranea will produce several generations per year in the Ebro Delta. H. l. mediterranea was characterized by a combination of early maturation of individuals (short juvenile period), rapid growth, small adult size, a continuous reproduction all year round, iteroparous females, a relatively high fecundity and a high number of generations per year.

Toxicity of lunar dust assessed in inhalation-exposed rats

PubMed Central

Lam, Chiu-wing; Scully, Robert R.; Zhang, Ye; Renne, Roger A.; Hunter, Robert L.; McCluskey, Richard A.; Chen, Bean T.; Castranova, Vincent; Driscoll, Kevin E.; Gardner, Donald E.; McClellan, Roger O.; Cooper, Bonnie L.; McKay, David S.; Marshall, Linda; James, John T.

2015-01-01

Humans will again set foot on the moon. The moon is covered by a layer of fine dust, which can pose a respiratory hazard. We investigated the pulmonary toxicity of lunar dust in rats exposed to 0, 2.1, 6.8, 20.8 and 60.6 mg/m3 of respirable-size lunar dust for 4 weeks (6 h/day, 5 days/week); the aerosols in the nose-only exposure chambers were generated from a jet-mill ground preparation of a lunar soil collected during the Apollo 14 mission. After 4 weeks of exposure to air or lunar dust, groups of five rats were euthanized 1 day, 1 week, 4 weeks or 13 weeks after the last exposure for assessment of pulmonary toxicity. Biomarkers of toxicity assessed in bronchoalveolar fluids showed concentration-dependent changes; biomarkers that showed treatment effects were total cell and neutrophil counts, total protein concentrations and cellular enzymes (lactate dehydrogenase, glutamyl transferase and aspartate transaminase). No statistically significant differences in these biomarkers were detected between rats exposed to air and those exposed to the two low concentrations of lunar dust. Dose-dependent histopathology, including inflammation, septal thickening, fibrosis and granulomas, in the lung was observed at the two higher exposure concentrations. No lesions were detected in rats exposed to ≤6.8 mg/m3. This 4-week exposure study in rats showed that 6.8 mg/m3 was the highest no-observable-adverse-effect level (NOAEL). These results will be useful for assessing the health risk to humans of exposure to lunar dust, establishing human exposure limits and guiding the design of dust mitigation systems in lunar landers or habitats. PMID:24102467

Early development of infants exposed to drugs prenatally.

PubMed

Eyler, F D; Behnke, M

1999-03-01

This article includes a summary and critique of methodological limitations of the peer-reviewed studies of developmental outcome during the first 2 years in children prenatally exposed to the most commonly used drugs of abuse: tobacco, alcohol, marijuana, heroin/methadone, and cocaine. Reported effects vary by specific drug or drug combinations and amount and timing of exposure; however, few thresholds have been established. Drug effects also appear to be exacerbated in children with multiple risks, including poverty, and nonoptimal caregiving environments. Although prenatal exposure to any one drug cannot reliably predict the outcome of an individual child, it may be a marker for an array of variables that can impact development. Appropriate intervention strategies require future research that determines which factors place exposed children at risk and which are protective for optimal development.

Increased oxidative stress in infants exposed to passive smoking.

PubMed

Aycicek, Ali; Erel, Ozcan; Kocyigit, Abdurrahim

2005-12-01

The purpose of this study was to assess the effect of passive cigarette smoking on the oxidative and anti-oxidative status of plasma in infants. Eighty-four infants aged 6-28 weeks were divided into two groups: the study group included infants who had been exposed to passive smoking via at least five cigarettes per day for at least the past 6 weeks at home, while the control group included infants who had never been exposed to passive smoking. The antioxidative status of plasma was assessed by the measurement of individual antioxidant components: vitamin C, albumin, bilirubin, uric acid, thiol contents and total antioxidant capacity (TAC 1 and TAC 2). Oxidative status was assessed by the determination of total peroxide levels and the oxidative stress index (OSI 1 and OSI 2). Plasma vitamin C, thiol concentration and TAC 1 and TAC 2 levels were significantly lower, whereas plasma total peroxide levels and OSI 1 and OSI 2 were significantly higher, in passive smoking infants than in the controls (P<0.01). We conclude that passive smoking has a negative impact on numerous parts of the antioxidant defence system in infants, and exposes them to potent oxidative stress.