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Sample records for contempt kangaroos persistently

  1. Explanations for Contempt Expressed Towards Old People.

    ERIC Educational Resources Information Center

    Maxwell, Eleanor Krassen; Maxwell, Robert J.

    The issue of contempt expressed towards the aged was examined from a cross-cultural perspective. Eight reasons for expressions of contempt emerged from a study of 95 societies drawn from the Standard Cross-Cultural Sample, and were treated as independent variables, with the overall level of contempt as the dependent variable, in a application of…

  2. 28 CFR 522.11 - Civil contempt commitments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Civil contempt commitments. 522.11..., CLASSIFICATION, AND TRANSFER ADMISSION TO INSTITUTION Civil Contempt of Court Commitments § 522.11 Civil contempt commitments. Inmates can come into Bureau custody for civil contempt commitments in two ways: (a) The...

  3. Kangaroos in the Classroom.

    ERIC Educational Resources Information Center

    Borst, Richard

    1989-01-01

    Describes a kangaroo simulation which can be adapted for use with radio tracking activities for other animals. Outlines procedures and information to help implement the activity. Provides a map of Australia, calculations, and sample kangaroo movement data. (RT)

  4. Kangaroo mother care.

    PubMed

    Bailey, Sarah

    2012-05-01

    Kangaroo mother care is a safe, simple method to care for low birth weight infants. This article looks at its origins, what is involved in kangaroo mother care and reviews the evidence for improved outcomes resulting from its implementation.

  5. 44 CFR 5.61 - Contempt for noncompliance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Contempt for noncompliance. 5.61 Section 5.61 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT... Contempt for noncompliance. In the event of noncompliance by FEMA with an order of a district...

  6. Dispositional Contempt: A First Look at the Contemptuous Person.

    PubMed

    Schriber, Roberta A; Chung, Joanne M; Sorensen, Katherine S; Robins, Richard W

    2016-06-09

    Contempt is a powerful emotion. Marriages fail (Gottman, 1994), coworkers are shamed (Melwani & Barsade, 2011), terrorism is tended toward (Tausch et al., 2011). Despite its importance, contempt has not been investigated at the level of personality. The present research examines how our contemptuous reactions can be conceptualized and measured as a stable individual-difference variable with a range of theoretically predicted correlates. First, we introduce a measure of dispositional contempt, the tendency to look down on, distance, and derogate others who violate our standards. We then unpack the dynamics of dispositional contempt. Across 6 studies using self-report and emotion elicitation in student and MTurk samples (Ns = 165 to 1,368), we examined its (a) nomological network, (b) personality and behavioral correlates, and (c) implications for relationship functioning. Dispositional contempt was distinguished from tendencies toward related emotions and was most associated with dispositional envy, anger, and hubristic pride. Somewhat paradoxically, dispositional contempt was related to being cold and "superior," with associations found with narcissism, other-oriented perfectionism, and various antisocial tendencies (e.g., Disagreeableness, Machiavellianism, racism), but it was also related to being self-deprecating and emotionally fragile, with associations found with low self-esteem, insecure attachment, and feeling that others impose perfectionistic standards on oneself. Dispositional contempt predicted contemptuous reactions to eliciting film clips, particularly when targets showed low competence/power. Finally, perceiving one's romantic partner as dispositionally contemptuous was associated with lower commitment and satisfaction. Taken together, results give a first look at the contemptuous person and provide a new organizing framework for understanding contempt. (PsycINFO Database Record

  7. Congress’s Contempt Power: Law, History, Practice, and Procedure

    DTIC Science & Technology

    2007-07-24

    that prosecution of Anne Gorsuch Burford, Administrator of the Environmental Protection Agency, was not required following implementation of an...House of Representatives against the Then-Administrator of the Environmental Protection Agency, Anne Gorsuch Burford, Hearing before the House Committee...not to present to the grand jury the contempt citation of Environmental Protection Agency Administration Anne Gorsuch Burford.157 CRS-27 157

  8. United Mine Workers V. Bagwell: New restrictions on severe civil contempt fines

    SciTech Connect

    1995-11-01

    In Bagwell II, the Supreme Court was asked to determine whether the trial court should have applied certain procedural protections, in effect limiting that court`s ability to impose millions of dollars in contempt sanctions. The Court found that the $52 million in fines levied against the United Mine Workers of America (UMWA) for violations of a Virginia Circuit Court`s order were {open_quotes}serious{close_quotes} enough to entitle the UMWA to the safeguards of a criminal jury trial. Bagwell Ii may be a step toward change. The Supreme Court acknowledged that its lack of guidance has resulted in an unrestrained use of the contempt power by lower courts. However, the Court refused to abandon the criminal/civil distinction created in Gompers, as some in favor of reform have suggested. Thus, the confusion over what constitutes a criminal contempt sanction as opposed to a civil contempt sanction continues. Bagwell II does appear to create a new catagory of indirect contempt. This catagory of contempt requires a level of procedural protection similar to those required in criminal contempt. The Court distinguishes these contempt from other civil contempt by considering the complexity of both the contemptuous conduct and the court order. As Justice Scalia noted in his concurring opinion, changes in use and form of court orders have made the traditional civil/criminal distinction an inadequate basis for attaching procedural rights.

  9. Bothriocroton concolor (Acari: Ixodidae) on the Kangaroo Island kangaroo: a new host-parasite relationship.

    PubMed

    Oorebeek, M; Rismiller, P

    2007-09-01

    In 2006, we examined Kangaroo Island kangaroos, Macropusfuliginosusfuliginosus, for ticks. We collected three tick species: Ixodes hirsti Hassall, Hemaphysalis bancrofti Nuttall & Warburton, and Bothriocroton concolor (Neumann). Surprisingly, the specimens included eight females and one nymph of B. concolor, which had previously been considered strictly host specific to the echidna (Tachyglossus sp.). This is the first record of B. concolor on the Kangaroo Island kangaroo.

  10. About Skin-to-Skin Care (Kangaroo Care)

    MedlinePlus

    ... Size Email Print Share About Skin-to-Skin Care Page Content Article Body You may be able ... care, also called kangaroo care. What is Kangaroo Care? Kangaroo care was developed in South America as ...

  11. Kangaroo Network. Annual Report, 1983.

    ERIC Educational Resources Information Center

    Seumahu, E. Steve

    This extensive report describes activities of the PEACESAT AUSTRALIA Project (the Kangaroo Network) which parallels, on the Australian continent, the endeavors of PEACESAT (Pacific Educational and Communication Experiment by SATellite), and other Pacific Basin ATS-1 networks. An executive summary reviews the development of the project and its…

  12. Peters anomaly in a red kangaroo (Macropus rufus).

    PubMed

    Suedmeyer, Wm Kirk; Pearce, Jacqueline; Persky, Meredith; Houck, Marlys L

    2014-09-01

    A 10-mo-old female red kangaroo (Macropus rufus) presented with a unilateral congenital corneal opacity OD. Complete ophthalmic examination revealed a shallow anterior chamber and a focal area of corneal edema with multiple persistent pupillary membranes extending from the iris colarette to the corneal endothelium adjacent to the edematous area of cornea. High-resolution B-scan ultrasound of the anterior segment showed an area consistent with thinning of Descemet's membrane in the area of corneal edema. Ophthalmic examination and ultrasound findings are consistent with a diagnosis of Peters anomaly, a form of anterior segment dysgenesis. An electroretinogram performed on the affected animal did not reveal any specific abnormalities. Karyotype analyses revealed a normal diploid number (2n = 20, -XX), with an abnormal pericentric inversion in the second largest chromosomal pair. The kangaroo exhibits mild compensated vision deficits in the affected eye. The maternal and paternal adult pairing has been discontinued in an effort to prevent future offspring anomalies.

  13. How Does a Hopping Kangaroo Breathe?

    ERIC Educational Resources Information Center

    Giuliodori, Mauricio J.; Lujan, Heidi L.; Janbaih, Hussein; DiCarlo, Stephen E.

    2010-01-01

    We developed a model to demonstrate how a hopping kangaroo breathes. Interestingly, a kangaroo uses less energy to breathe while hopping than while standing still. This occurs, in part, because rather than using muscle power to move air into and out of the lungs, air is pulled into (inspiration) and pushed out of (expiration) the lungs as the…

  14. How does a hopping kangaroo breathe?

    PubMed

    Giuliodori, Mauricio J; Lujan, Heidi L; Janbaih, Hussein; DiCarlo, Stephen E

    2010-12-01

    We developed a model to demonstrate how a hopping kangaroo breathes. Interestingly, a kangaroo uses less energy to breathe while hopping than while standing still. This occurs, in part, because rather than using muscle power to move air into and out of the lungs, air is pulled into (inspiration) and pushed out of (expiration) the lungs as the abdominal organs "flop" within the kangaroo's body. Specifically, as the kangaroo hops upward, the abdominal organs lag behind, and the insertion of the diaphragm is pulled toward its origin, flattening the dome and increasing the vertical dimension of the thoracic cavity (the thoracic cavity and lungs enlarge). Increasing the volume of the thoracic cavity reduces alveolar pressure below atmospheric pressure (barometric pressure), and air moves into the alveoli by bulk flow. In contrast, the impact of the organs against the diaphragm at each landing causes expiration. Specifically, upon landing, the abdominal organs flop into the diaphragm, causing it to return to its dome shape and decreasing the vertical dimension of the thoracic cavity. This compresses the alveolar gas volume and elevates alveolar pressure above barometric pressure, so air is expelled. To demonstrate this phenomenon, the plunger of a syringe model of the respiratory system was inserted through a compression spring. Holding the syringe and pressing the plunger firmly against a hard surface expels air from the lungs (the balloon within the syringe deflates) and compresses the spring. This models the kangaroo landing after a hop forward. Subsequently, the compression spring provides the energy for the "kangaroo" to "hop" forward upon the release of the syringe, and air enters the lungs (the balloon within the syringe inflates). The model accurately reflects how a hopping kangaroo breathes. A model was chosen to demonstrate this phenomenon because models engage and inspire students as well as significantly enhance student understanding.

  15. A Brief History of Kangaroos (and Lesser Mammals).

    ERIC Educational Resources Information Center

    Cooke, Bernard N.

    1999-01-01

    Describes a new hypothesis regarding the origin of bulungamayine kangaroos. Suggests that this group of Oglio-Miocene kangaroos independently evolved adaptations for herbivory and are likely to be ancestral to modern and recently extinct plant-eating kangaroos. (Contains 17 references.) (Author/WRM)

  16. Phylogeography of Eastern Grey Kangaroos, Macropus giganteus, Suggests a Mesic Refugium in Eastern Australia

    PubMed Central

    2015-01-01

    Phylogeographic studies around the world have identified refugia where fauna were able to persist during unsuitable climatic periods, particularly during times of glaciation. In Australia the effects of Pleistocene climate oscillations on rainforest taxa have been well studied but less is known about the effects on mesic-habitat fauna, such as the eastern grey kangaroo (Macropus giganteus). The eastern grey kangaroo is a large mammal that is common and widespread throughout eastern Australia, preferring dry mesic habitat, rather than rainforest. As pollen evidence suggests that the central-eastern part of Australia (southeast Queensland and northern New South Wales) experienced cycles of expansion in mesic habitat with contraction in rainforests, and vice versa during glacial and interglacial periods, respectively, we hypothesise that the distribution of the eastern grey kangaroo was affected by these climate oscillations and may have contracted to mesic habitat refugia. From 375 mitochondrial DNA control region sequences from across the distribution of eastern grey kangaroos we obtained 108 unique haplotypes. Phylogenetic analysis identified two clades in Queensland, one of which is newly identified and restricted to a small coastal region in southern Queensland north of Brisbane, known as the Sunshine Coast. The relatively limited geographic range of this genetically isolated clade suggests the possibility of a mesic habitat refugium forming during rainforest expansion during wetter climate cycles. Other potential, although less likely, reasons for the genetic isolation of the highly distinct clade include geographic barriers, separate northward expansions, and strong local adaptation. PMID:26024370

  17. Persistence

    NASA Astrophysics Data System (ADS)

    Moore, John W.

    1998-11-01

    Eudora Welty, the famous writer, was once asked what should be done by society or government to encourage young writers. Her response, which surprised the questioner, and me when I heard it, was "Nothing". Welty contended that a person who was really a writer would be persistent enough to overcome whatever obstacles were in the way, needing no interference or support from others.

  18. Kangaroo Mother Care--a review.

    PubMed

    Hall, D; Kirsten, G

    2008-04-01

    Kangaroo Mother Care is a simple and beneficial intervention for the care of low birth weight infants. Although initially conceived for use in developing countries with limited resources, its use has expanded worldwide as clinicians, administrators and parents become familiar with the psychological, physiological, clinical and cost benefits associated with the practice. A recently documented benefit has specific relevance to blood transfusion medicine.

  19. Effect of the kangaroo position on the electromyographic activity of preterm children: a follow-up study

    PubMed Central

    2013-01-01

    Background One of the components of the Kangaroo Method (KM) is the adoption of the Kangaroo Position. The skin-to-skin contact and the vertical position the child adopts when in this position may provide sensorial, vestibular and postural stimuli for the newborn. The Kangaroo Position may encourage vestibular stimuli and a flexed posture of the limbs, suggesting the hypothesis that the Kangaroo Position may have an impact on flexor muscle tone. The effect of these stimuli on the motor features of the newborn has not been the subject of much investigation. No study has yet been conducted to determine whether the Kangaroo Position may progressively increase electromyographic activity or whether this increase persists until term-equivalent age. The aim of this study was to evaluate the effect of the Kangaroo Position on the electromyographic activity of preterm children. Method A follow-up study was carried out between July and November 2011 at the Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Recife-Brazil, using a sample of 30 preterm children. Surface Eletromyography (SEMG) was used to investigate the muscle activity of biceps brachii. The electromyographic readings were taken immediately before (0 h) and after 24 h, 48 h, 72 h, 96 h of application of the Kangaroo Position as well as at the term equivalent age in each baby. Electromyographic activity was analyzed using the Root Mean Square (RMS) and the mean values of the times were analyzed by way of analysis of variance for repeated measures and the Tukey test. Results Electromyographic activity of the biceps brachii varied and increased over the whole 96h period (RMS:0 h = 36.5 and 96 h = 52.9) (F(5.174) = 27.56; p < 0.001) and remained constant thereafter (RMS: term-equivalent age = 54.2). The correlations between the corrected age and the values for electromyographic activity did not show any statistical significance. Conclusion The Kangaroo Position leads to a growing

  20. Intermittent kangaroo mother care: a NICU protocol.

    PubMed

    Davanzo, Riccardo; Brovedani, Pierpaolo; Travan, Laura; Kennedy, Jacqueline; Crocetta, Anna; Sanesi, Cecilia; Strajn, Tamara; De Cunto, Angela

    2013-08-01

    The practice of kangaroo mother care (KMC) is steadily increasing in high-tech settings due to its proven benefits for both infants and parents. In spite of that, clear guidelines about how to implement this method of care are lacking, and as a consequence, some restrictions are applied in many neonatal intensive care units (NICUs), preventing its practice. Based on recommendations from the Expert Group of the International Network on Kangaroo Mother Care, we developed a hospital protocol in the neonatal unit of the Institute for Maternal and Child Health in Trieste, Italy, a level 3 unit, aimed to facilitate and promote KMC implementation in high-tech settings. Our guideline is therefore proposed, based both on current scientific literature and on practical considerations and experience. Future adjustments and improvements would be considered based on increasing clinical KMC use and further knowledge.

  1. Kangaroo mother care: a systematic review of barriers and enablers

    PubMed Central

    Labar, Amy S; Wall, Stephen; Atun, Rifat

    2016-01-01

    Abstract Objective To investigate factors influencing the adoption of kangaroo mother care in different contexts. Methods We searched PubMed, Embase, Scopus, Web of Science and the World Health Organization’s regional databases, for studies on “kangaroo mother care” or “kangaroo care” or “skin-to-skin care” from 1 January 1960 to 19 August 2015, without language restrictions. We included programmatic reports and hand-searched references of published reviews and articles. Two independent reviewers screened articles and extracted data on carers, health system characteristics and contextual factors. We developed a conceptual model to analyse the integration of kangaroo mother care in health systems. Findings We screened 2875 studies and included 112 studies that contained qualitative data on implementation. Kangaroo mother care was applied in different ways in different contexts. The studies show that there are several barriers to implementing kangaroo mother care, including the need for time, social support, medical care and family acceptance. Barriers within health systems included organization, financing and service delivery. In the broad context, cultural norms influenced perceptions and the success of adoption. Conclusion Kangaroo mother care is a complex intervention that is behaviour driven and includes multiple elements. Success of implementation requires high user engagement and stakeholder involvement. Future research includes designing and testing models of specific interventions to improve uptake. PMID:26908962

  2. HYPOALDOSTERONISM IN A MATSCHIE'S TREE KANGAROO (DENDROLAGUS MATSCHIEI).

    PubMed

    Whoriskey, Sophie T; Bartlett, Susan L; Baitchman, Eric

    2016-06-01

    A 20-yr-old female Matschie's tree kangaroo (Dendrolagus matschiei) was diagnosed with hypoaldosteronism, a rare condition in which the body fails to produce normal amounts of the mineralocorticoid aldosterone. Aldosterone plays a key role in body salt homeostasis, increasing sodium reabsorption and promoting excretion of potassium. Hypoaldosteronism resulted in decreased appetite, lethargy, and weight loss in conjunction with hyponatremia, hyperkalemia, and hypercalcemia in this tree kangaroo. The animal was successfully managed with mineralocorticoid replacement using desoxycorticosterone pivalate. To the authors' knowledge this is the first report of hypoaldosteronism in a tree kangaroo and one of the few reports in the veterinary literature in any species.

  3. The motilin gene evolved a new function in kangaroo rats and kangaroo mice (Dipodomyinae).

    PubMed

    He, Jing; Zhou, Taicheng; Irwin, David M; Shen, Yongyi; Zhang, Yaping

    2012-10-01

    The motilin receptor gene was lost in the ancestral lineage of rodents. Subsequently, the gene encoding its ligand, motilin, has experienced different evolutionary fates. Previous genomic analyses had shown that the motilin gene (MLN) became a pseudogene independently in the lineages leading to the guinea pig and the common ancestor of the mouse and rat, yet an intact, and thus potentially functional, open reading frame for the MLN was preserved in the Dipodomys ordii genome. As only a single MLN haplotype from D. ordii was available, and this sequence is from a low coverage draft genome, it is possible that the intact MLN found in the draft kangaroo rat genome is an artifact, or represents an intermediate in the process of becoming a pseudogene. In order to establish whether an intact MLN is retained in kangaroo rats despite the loss of its specific receptor, and to investigate the evolutionary mechanisms underlying the retention of this gene sequence, we isolated MLN sequences from species that represent the diversity of the Dipodomyinae [the monophyletic Dipodomyinae subfamily consists of two genera: Dipodomys (kangaroo rats) and Microdipodops (kangaroo mice)]. The results demonstrate that the MLN sequence is well conserved in Dipodomyinae, and it codes for a predicted motilin peptide sequence possessing a conserved N-terminal pharmacophore and the potential to be processed and secreted as a hormone. The observations that the MLN evolved as a functional gene during the radiation of the Dipodomyinae, species that have lost their original motilin receptor, suggest that the MLN has undergone a lineage-specific physiological adaptation to a new function.

  4. Gastric trichobezoar in a banner-tailed kangaroo rat (Dipodomys spectabilis).

    PubMed

    Suckow, M A; Terril-Robb, L A; Grigdesby, C F

    1996-10-01

    A male, wild-caught kangaroo rat developed anorexia and wasting. The animal was euthanized and a gastric trichobezoar found at necropsy. The paucity of information regarding the clinical medicine of this species is a hindrance to those charged with the care of kangaroo rats. Gastric trichobezoar should be considered as a differential diagnosis in cases of anorexia in kangaroo rats.

  5. Masticatory muscles of the great-gray kangaroo (Macropus giganteus).

    PubMed

    Tomo, Soichiro; Tomo, Ikuko; Townsend, Grant C; Hirata, Kazuaki

    2007-04-01

    The great-gray kangaroo (Macropus giganteus) belongs to the Diprotodontia suborder (herbivorous marsupials of Australia) of the order of marsupials. We dissected the masticatory muscles in the great-gray kangaroo and classified them based on their innervation. Three (two male and one female) adult great-gray kangaroos (M. giganteus), fixed with 10% formalin, were examined. The masseter muscle of the great-gray kangaroo was classified into four layers (superficial layers 1, 2, 3, and a deep layer), all innervated by masseteric nerves. Layer 1 of the masseter muscle was well developed and the deep layer inserted into the masseteric canal. The zygomaticomandibular muscle, which belongs to both the masseter and temporalis muscles, was innervated by both the masseteric nerve and posterior deep temporal nerve, and the temporalis muscle was innervated by the anterior and posterior deep temporal nerves. The medial pterygoid muscle, which was innervated by the medial pterygoid nerve, was divided into superficial and deep portions. The lateral pterygoid muscle was divided into superior and inferior heads by the buccal nerve. We propose that the relationship of the masticatory muscles in the kangaroo has evolved by passive anterior invasion of the deep layer of the masseter by the medial pterygoid muscle via the masseteric canal, associated with the development of an anteroposterior mode of mastication.

  6. Morphology of the lingual papillae in the eastern grey kangaroo.

    PubMed

    Emura, Shoichi

    2016-01-01

    We examined the dorsal lingual surface of an adult eastern grey kangaroo (Macropus gigantues) by scanning electron microscopy. The filiform papillae on the lingual apex and anterior body consisted of a main papilla and secondary papillae. The connective tissue core of the filiform papillae on the lingual apex had several processes. The filiform papillae on the lingual posterior body were thread-like in shape. The connective tissue core of the filiform papillae on the lingual posterior body consisted of many slender processes. The fungiform papillae were round in shape. Three vallate papillae with the apex of the triangle directed posteriorly consisted of a groove and pad. Several conical papillae derived from the posterolateral margin of the tongue where foliate papillae have been shown to be distributed in many other animal species. The surface structure of the tongue in the eastern grey kangaroo resembles that of the red kangaroo.

  7. Barrier Crossing and Transport Activated by Kangaroo Fluctuations

    NASA Astrophysics Data System (ADS)

    Kostur, M.; Luczka, J.

    1999-01-01

    We study barrier crossing of Brownian particles in a bistable symmetric potential and transport of Brownian particles in spatially periodic structures, driven by both kangaroo fluctuations and thermal equilibrium noise of zero mean values. We consider exponentially and algebraically correlated kangaroo fluctuations. Starting with the full Newton--Langevin equation for the Brownian particle and by introducing scaling as well as dimensionless variables, we show that the equation is very well approximated by overdamped dynamics in which inertial effects can be neglected. We analyze properties of selected macroscopic characteristics of the system such as the mean first passage time (MFPT) of particles from one minimum of the bistable potential to the other and mean stationary velocity of particles moving in a spatially periodic potential. In dependence upon statistics of kangaroo fluctuations and temperature of the system, macroscopic characteristics exhibit distinctive non-monotonic behavior. Accordingly, there exist optimal statistics of fluctuations optimizing macroscopic characteristics.

  8. Spatial memory in the desert kangaroo rat (Dipodomys deserti).

    PubMed

    Langley, C M

    1994-03-01

    Desert kangaroo rats (Dipodomys deserti) forage for seed distributed in patches in the desert environment and may remember patch locations. In Experiment 1, 7 desert kangaroo rats that had discovered the location of a plastic token in 1 box accurately dug for a token hidden in the same location in a 2nd identical box. Results of Experiment 2 indicated that the rats primarily remembered the spatial location of the token within the box in relation to extramaze objects and the walls of the experimental box. Female rats also remembered the chip's location in relation to objects inside the box, but males did not. Experiment 3 demonstrated that the rats' ability to locate the buried token did not depend on detection of the odor of the token. In the discussion I propose that spatial memory in kangaroo rats may have evolved as a result of an overall change in the ontogeny of the species rather than as a specialized adaptation for foraging efficiency.

  9. The Story behind "Quest for the Tree Kangaroo"

    ERIC Educational Resources Information Center

    Young, Terrell A.; Ward, Barbara A.

    2007-01-01

    The National Council of Teachers of English awarded the coveted nonfiction prize to "Quest for the Tree Kangaroo: An Expedition to the Cloud Forest of New Guinea." Written by Sy Montgomery, with photographs by Nic Bishop, the book was further honored as a Robert F. Sibert Informational Book Medal Honor recipient by the Association for…

  10. [Kangaroo Mother Care and conventional care: a review of literature].

    PubMed

    Bulfone, Giampiera; Nazzi, Elisa; Tenore, Alfred

    2011-01-01

    Low birth weight is one of the major health problems throughout the world. All such neonates can benefit from an effective and efficient human care model - Kangaroo Mother Care. A review of the literature was performed to compare the short and long-term outcome of Kangaroo Mother Care to those of conventional care (incubator). Short-term outcome considered heart and breathing frequency, percutaneous oxygen saturation , transcutaneous oxygen pressure , body temperature, sleep-wake cycles, stress and pain. Long-term outcome considered mortality, somatic, psycho-motor and cognitive development, the incidence of infections and duration of hospitalization. Studies including pre-term neonates were also included. 19 of the 80 studies corresponded to the study criteria and demonstrated that Kangaroo Mother Care is important because it reduces pain and infections, shortens hospitalization, favors breast-feeding: in comparison to neonates treated conventionally, this method results in an earlier and better cognitive and motor development . Concerning body temperature, there were no differences with respect to traditional care. The literature shows that the Kangaroo Mother Care method can be a useful "adjunctive" strategy although further studies are necessary to clarify aspects such as heart and breathing rate and oxygen saturation that appear contradictory.

  11. Kangaroo vs. porcine aortic valves: calcification potential after glutaraldehyde fixation.

    PubMed

    Narine, K; Chéry, Cyrille C; Goetghebeur, Els; Forsyth, R; Claeys, E; Cornelissen, Maria; Moens, L; Van Nooten, G

    2005-01-01

    The aim of this study was to evaluate and compare the calcification potential of kangaroo and porcine aortic valves after glutaraldehyde fixation at both low (0.6%) and high (2.0%) concentrations of glutaraldehyde in the rat subcutaneous model. To our knowledge this is the first report comparing the time-related, progressive calcification of these two species in the rat subcutaneous model. Twenty-two Sprague-Dawley rats were each implanted with two aortic valve leaflets (porcine and kangaroo) after fixation in 0.6% glutaraldehyde and two aortic valve leaflets (porcine and kangaroo) after fixation in 2% glutaraldehyde respectively. Animals were sacrificed after 24 h and thereafter weekly for up to 10 weeks after implantation. Calcium content was determined using inductively coupled plasma-mass spectrometry and confirmed histologically. Mean calcium content per milligram of tissue (dry weight) treated with 0.6 and 2% glutaraldehyde was 116.2 and 110.4 microg/mg tissue for kangaroo and 95.0 and 106.8 microg/mg tissue for porcine valves. Calcium content increased significantly over time (8.8 microg/mg tissue per week) and was not significantly different between groups. Regression analysis of calcification over time showed no significant difference in calcification of valves treated with 0.6 or 2% glutaraldehyde within and between the two species. Using the subcutaneous model, we did not detect a difference in calcification potential between kangaroo and porcine aortic valves treated with either high or low concentrations of glutaraldehyde.

  12. Locomotion energetics and gait characteristics of a rat-kangaroo, Bettongia penicillata, have some kangaroo-like features.

    PubMed

    Webster, K N; Dawson, T J

    2003-09-01

    The locomotory characteristics of kangaroos and wallabies are unusual, with both energetic costs and gait parameters differing from those of quadrupedal running mammals. The kangaroos and wallabies have an evolutionary history of only around 5 million years; their closest relatives, the rat-kangaroos, have a fossil record of more than 26 million years. We examined the locomotory characteristics of a rat-kangaroo, Bettongia penicillata. Locomotory energetics and gait parameters were obtained from animals exercising on a motorised treadmill at speeds from 0.6 m s(-1) to 6.2 m s(-1). Aerobic metabolic costs increased as hopping speed increased, but were significantly different from the costs for a running quadruped; at the fastest speed, the cost of hopping was 50% of the cost of running. Therefore B. penicillata can travel much faster than quadrupedal runners at similar levels of aerobic output. The maximum aerobic output of B. penicillata was 17 times its basal metabolism. Increases in speed during hopping were achieved through increases in stride length, with stride frequency remaining constant. We suggest that these unusual locomotory characteristics are a conservative feature among the hopping marsupials, with an evolutionary history of 20-30 million years.

  13. Reproductive strategies of the kangaroo leech, Marsupiobdella africana (Glossiphoniidae)

    PubMed Central

    Kruger, Natasha; Du Preez, Louis

    2015-01-01

    The Kangaroo Leech, Marsupiobdella africana, is a hermaphroditic organism, with insemination taking place by the planting of a spermatophore on another leech. Spermatophores are mostly planted on the anterior of the recipient leech, but not always. Several spermatophores may be planted by different leeches on a single recipient. The spermatophore consists of two side by side lobes. Within minutes from planting of the spermatophore, the contents are squeezed out and into the body of the recipient. Sperm are believed to find the way to the ova by following chemical cues. Kangaroo Leeches display advanced parental care by transferring fertilized eggs from the reproductive opening to a brood pouch on the ventral side. Fully developed leeches may copulate after detaching from the amphibian host Xenopus laevis, or from the Cape River Crab Potamonautes perlatus with which it maintains a phoretic association. PMID:25830114

  14. Magnetic resonance imaging findings in a red kangaroo (Macropus rufus) with otitis.

    PubMed

    Okeson, Danelle M; Coke, Rob L; Kochunov, Peter; Davis, M Duff

    2008-12-01

    Magnetic resonance imaging (MRI) was performed on an adult, male Red kangaroo (Macropus rufus) with a history of nonspecific neurologic signs and acute discharge from the left ear. MRI revealed findings consistent with otitis and possible osteomyelitis of the temporal and mastoid bones. To the authors' knowledge, this is the first report of otitis and MRI findings in a kangaroo.

  15. Kangaroo rat bone compared to white rat bone after short-term disuse and exercise

    USGS Publications Warehouse

    Muths, E.; Reichman, O. J.

    1996-01-01

    Kangaroo rats (Dipodomys ordii) were used to study the effects of confinement on mechanical properties of bone with a long range objective of proposing an alternative to the white rat model for the study of disuse osteoporosis. Kangaroo rats exhibit bipedal locomotion, which subjects their limbs to substantial accelerative forces in addition to the normal stress of weight bearing. We subjected groups of kangaroo rats and white rats (Rattus norvegicus) to one of two confinement treatments or to an exercise regime; animals were exercised at a rate calculated to replicate their (respective) daily exercise patterns. White laboratory rats were used as the comparison because they are currently the accepted model used in the study of disuse osteoporosis. After 6 weeks of treatment, rats were killed and the long bones of their hind limbs were tested mechanically and examined for histomorphometric changes. We found that kangaroo rats held in confinement had less ash content in their hind limbs than exercised kangaroo rats. In general, treated kangaroo rats showed morphometric and mechanical bone deterioration compared to controls and exercised kangaroo rats appeared to have slightly “stronger” bones than confined animals. White rats exhibited no significant differences between treatments. These preliminary results suggest that kangaroo rats may be an effective model in the study of disuse osteoporosis.

  16. Kangaroo rat bone compared to white rat bone after short-term disuse and exercise.

    PubMed

    Muths, E; Reichman, O J

    1996-08-01

    Kangaroo rats (Dipodomys ordii) were used to study the effects of confinement on mechanical properties of bone with a long range objective of proposing an alternative to the white rat model for the study of disuse osteoporosis. Kangaroo rats exhibit bipedal locomotion, which subjects their limbs to substantial accelerative forces in addition to the normal stress of weight bearing. We subjected groups of kangaroo rats and white rats (Rattus norvegicus) to one of two confinement treatments or to an exercise regime; animals were exercised at a rate calculated to replicate their (respective) daily exercise patterns. White laboratory rats were used as the comparison because they are currently the accepted model used in the study of disuse osteoporosis. After 6 weeks of treatment, rats were killed and the long bones of their hind limbs were tested mechanically and examined for histomorphometric changes. We found that kangaroo rats held in confinement had less ash content in their hind limbs than exercised kangaroo rats. In general, treated kangaroo rats showed morphometric and mechanical bone deterioration compared to controls and exercised kangaroo rats appeared to have slightly "stronger" bones than confined animals. White rats exhibited no significant differences between treatments. These preliminary results suggest that kangaroo rats may be an effective model in the study of disuse osteoporosis.

  17. The Kangaroo Mother Care Method: from scientific evidence generated in Colombia to worldwide practice.

    PubMed

    Charpak, Nathalie; Ruiz, Juan Gabriel

    2016-10-17

    Kangaroo Mother Care (KMC) is a human-based care intervention devised to complement neonatal care for low birth weight and premature infants. Kangaroo position (skin-to-skin contact on the mother's chest) offers thermal regulation, physiological stability, appropriate stimulation, and enhances bonding and breastfeeding. Kangaroo nutrition is based on breastfeeding, and kangaroo discharge policy relies on family empowerment and early discharge in kangaroo position with close ambulatory follow-up. We describe how the evidence has been developed and how it has been put into practice by means of direct preterm infants care and dissemination of the method, including training of KMC excellence centers in many countries not only in Latin America but worldwide.

  18. What is kangaroo mother care? Systematic review of the literature

    PubMed Central

    Chan, Grace J; Valsangkar, Bina; Kajeepeta, Sandhya; Boundy, Ellen O; Wall, Stephen

    2016-01-01

    Background Kangaroo mother care (KMC), often defined as skin–to–skin contact between a mother and her newborn, frequent or exclusive breastfeeding, and early discharge from the hospital has been effective in reducing the risk of mortality among preterm and low birth weight infants. Research studies and program implementation of KMC have used various definitions. Objectives To describe the current definitions of KMC in various settings, analyze the presence or absence of KMC components in each definition, and present a core definition of KMC based on common components that are present in KMC literature. Methods We conducted a systematic review and searched PubMed, Embase, Scopus, Web of Science, and the World Health Organization Regional Databases for studies with key words “kangaroo mother care”, “kangaroo care” or “skin to skin care” from 1 January 1960 to 24 April 2014. Two independent reviewers screened articles and abstracted data. Findings We screened 1035 articles and reports; 299 contained data on KMC and neonatal outcomes or qualitative information on KMC implementation. Eighty–eight of the studies (29%) did not define KMC. Two hundred and eleven studies (71%) included skin–to–skin contact (SSC) in their KMC definition, 49 (16%) included exclusive or nearly exclusive breastfeeding, 22 (7%) included early discharge criteria, and 36 (12%) included follow–up after discharge. One hundred and sixty–seven studies (56%) described the duration of SSC. Conclusions There exists significant heterogeneity in the definition of KMC. A large number of studies did not report definitions of KMC. Skin–to–skin contact is the core component of KMC, whereas components such as breastfeeding, early discharge, and follow–up care are context specific. To implement KMC effectively development of a global standardized definition of KMC is needed. PMID:27231546

  19. Lens growth and protein changes in the eastern grey kangaroo

    PubMed Central

    2011-01-01

    Purpose Development in marsupials takes place predominantly ex utero while the young is attached to a nipple in the mother’s pouch, very different from that in other species. This study was undertaken to examine whether this affects lens growth and the production of lens proteins in kangaroos. Methods Fresh lenses were obtained at official culls from eastern gray kangaroos (Macropus giganteus). Wet weights were recorded for all and protein contents were determined for one lens from each animal. Dry weights, after fixation were obtained for 20 lenses. Ages were determined using both molar progression and total lens protein content. Lenses were divided into concentric layers by controlled dissolution using phosphate buffered saline. Samples were taken for determination of protein contents and dry weights, which were then used to determine the age of the layer removed. Soluble crystallin distributions were determined by fractionation of the centrifuged extracts using HPLC-GPC and the polypeptide contents of both soluble and insoluble proteins were assessed by SDS–PAGE. Results Lens growth is continuous from birth throughout adulthood and the increases in wet weight and fixed dry weight can be described with a single logistic growth functions for the whole life span. Three major crystallin classes, α-, β-, and γ-crystallins, were identified in the immature pouch-young animals aged around 60 days after birth. Adult lenses contain, in addition, the taxon-specific μ-crystallin. The proportions of these vary with the age of the lens tissue due to age related insolubilization as well as changes in the synthesis patterns. During early lactation (birth to 190 days), the α-, β-, and γ-crystallins represent 25, 53, and 20% of the total protein, respectively. After the pouch-young first releases the nipple (190 days), there is a rapid decrease in the production of γ-crystallins to around 5% of the total and a corresponding increase in μ-crystallin, from 0.5% to 15

  20. Overcoming the barriers to using kangaroo care in neonatal settings.

    PubMed

    Penn, Sarah

    2015-06-01

    Skin-to-skin contact, or kangaroo care (KC), has benefits for babies and parents, improving clinical outcomes, temperature control, breastfeeding rates and child-parent bonding; it reduces morbidity and mortality. Barriers to KC for neonates may include a lack of training for nurses, lack of time, maternal or child physical or mental ill health, and inappropriate settings. With education and helpful management, neonatal nurses can advocate for KC for all babies. Parents may need information and encouragement to begin with. Therefore, nurses can improve the experiences of their patients and, in the long run, free time to perform clinical procedures.

  1. Purification, amino acid sequence and characterisation of kangaroo IGF-I.

    PubMed

    Yandell, C A; Francis, G L; Wheldrake, J F; Upton, Z

    1998-01-01

    Insulin-like growth factor-I (IGF-I) and IGF-II have been purified to homogeneity from kangaroo (Macropus fuliginosus) serum, thus this represents the first report of the purification, sequencing and characterisation of marsupial IGFs. N-Terminal protein sequencing reveals that there are six amino acid differences between kangaroo and human IGF-I. Kangaroo IGF-II has been partially sequenced and no differences were found between human and kangaroo IGF-II in the 53 residues identified. Thus the IGFs appear to be remarkably structurally conserved during mammalian radiation. In addition, in vitro characterisation of kangaroo IGF-I demonstrated that the functional properties of human, kangaroo and chicken IGF-I are very similar. In an assay measuring the ability of the proteins to stimulate protein synthesis in rat L6 myoblasts, all IGF-I proteins were found to be equally potent. The ability of all three proteins to compete for binding with radiolabelled human IGF-I to type-1 IGF receptors in L6 myoblasts and in Sminthopsis crassicaudata transformed lung fibroblasts, a marsupial cell line, was comparable. Furthermore, kangaroo and human IGF-I react equally in a human IGF-I RIA using a human reference standard, radiolabelled human IGF-I and a polyclonal antibody raised against recombinant human IGF-I. This study indicates that not only is the primary structure of eutherian and metatherian IGF-I conserved, but also the proteins appear to be functionally similar.

  2. The phylogenetic position of the musky rat-kangaroo and the evolution of bipedal hopping in kangaroos (Macropodidae: Diprotodontia).

    PubMed

    Burk, A; Westerman, M; Springer, M

    1998-09-01

    Kangaroos and their relatives (family Macropodidae) are divided into the subfamilies Macropodinae (kangaroos, wallabies, pademelons) and Potoroinae (rat-kangaroos, potoroos, bettongs). The musky rat-kangaroo, Hypsiprymnodon moschatus, is traditionally allied with other potoroines, based primarily on the basis of osteological characters and aspects of the female reproductive system. Unlike other macropodids, however, which are capable of bipedal hopping, Hypsiprymnodon is a quadrupedal bounder and lacks several derived features of the pes and tarsus that are presumably adaptations for bipedal hopping. Other derived features, such as a complex stomach, loss of P2 with the eruption of P3, and reduction of litter size to one, are also lacking in Hypsiprymnodon but occur in all other macropodids. Thus, available evidence suggests that Hypsiprymnodon either is part of a monophyletic Potoroinae or is a sister taxon to other living macropodids. To test these hypotheses, we sequenced 1,170 bp base pairs of the mitochondrial genome for 16 macropodids. Maximum parsimony, minimum evolution, maximum likelihood, and quartet puzzling all support the hypothesis that macropodines and potoroines are united to the exclusion of Hypsiprymnodon. This hypothesis implies that characters such as bipedal hopping evolved only once in macropodid evolution. Aside from Hypsiprymnodon, the remaining macropodids separate into the traditional Macropodinae and Potoroinae. Macropodines further separate into two clades: one containing the New Guinean forest wallabies Dorcopsis and Dorcopsulus, and one consisting of the genera Macropus, Setonix, Thylogale, Onychogalea, Wallabia, Dendrolagus, Peradorcas, and Lagorchestes. Among potoroines, there is moderate support for the association of Bettongia and Aepyprymnus to the exclusion of Potorous. Divergence times were estimated by using 12S ribosomal RNA transversions. At the base of the macropodid radiation, Hypsiprymnodon diverged from other macropodids

  3. Inferring Kangaroo Phylogeny from Incongruent Nuclear and Mitochondrial Genes

    PubMed Central

    Phillips, Matthew J.; Haouchar, Dalal; Pratt, Renae C.; Gibb, Gillian C.; Bunce, Michael

    2013-01-01

    The marsupial genus Macropus includes three subgenera, the familiar large grazing kangaroos and wallaroos of M. (Macropus) and M. (Osphranter), as well as the smaller mixed grazing/browsing wallabies of M. (Notamacropus). A recent study of five concatenated nuclear genes recommended subsuming the predominantly browsing Wallabia bicolor (swamp wallaby) into Macropus. To further examine this proposal we sequenced partial mitochondrial genomes for kangaroos and wallabies. These sequences strongly favour the morphological placement of W. bicolor as sister to Macropus, although place M. irma (black-gloved wallaby) within M. (Osphranter) rather than as expected, with M. (Notamacropus). Species tree estimation from separately analysed mitochondrial and nuclear genes favours retaining Macropus and Wallabia as separate genera. A simulation study finds that incomplete lineage sorting among nuclear genes is a plausible explanation for incongruence with the mitochondrial placement of W. bicolor, while mitochondrial introgression from a wallaroo into M. irma is the deepest such event identified in marsupials. Similar such coalescent simulations for interpreting gene tree conflicts will increase in both relevance and statistical power as species-level phylogenetics enters the genomic age. Ecological considerations in turn, hint at a role for selection in accelerating the fixation of introgressed or incompletely sorted loci. More generally the inclusion of the mitochondrial sequences substantially enhanced phylogenetic resolution. However, we caution that the evolutionary dynamics that enhance mitochondria as speciation indicators in the presence of incomplete lineage sorting may also render them especially susceptible to introgression. PMID:23451266

  4. Selected diagnostic ophthalmic tests in the red kangaroo (Macropus rufus).

    PubMed

    Takle, Ginger L; Suedmeyer, W Kirk; Hunkeler, Amy

    2010-06-01

    The following tests were performed on a total of 20 eyes: Schirmer tear test, intraocular pressure (IOP), assessment of conjunctival flora, and pupillary diameter with application of topical tropicamide in 10 healthy captive red kangaroos (Macropus rufus) under manual restraint. The mean Schirmer tear test value was 22.6 +/- 6.07 mm/min. The mean intraocular pressure was 17.45 +/- 7.23 mm Hg. Values did not differ between eyes or gender for either test, but significant differences were identified for IOP values according to age. The most common bacteria isolated from the conjunctival fornix were Staphylococcus epidermidis (54.5%) and Corynebacterium sp. (18.2%). The mean onset of mydriasis after instillation of 1% tropicamide ophthalmic solution was 16.7 +/- 3.34 min and the mean duration of effect was 17.6 +/- 8.26 hr. The data obtained in this investigation will aid veterinary ophthalmologists and zoo veterinarians to diagnose ocular diseases in the red kangaroo accurately.

  5. Inferring kangaroo phylogeny from incongruent nuclear and mitochondrial genes.

    PubMed

    Phillips, Matthew J; Haouchar, Dalal; Pratt, Renae C; Gibb, Gillian C; Bunce, Michael

    2013-01-01

    The marsupial genus Macropus includes three subgenera, the familiar large grazing kangaroos and wallaroos of M. (Macropus) and M. (Osphranter), as well as the smaller mixed grazing/browsing wallabies of M. (Notamacropus). A recent study of five concatenated nuclear genes recommended subsuming the predominantly browsing Wallabia bicolor (swamp wallaby) into Macropus. To further examine this proposal we sequenced partial mitochondrial genomes for kangaroos and wallabies. These sequences strongly favour the morphological placement of W. bicolor as sister to Macropus, although place M. irma (black-gloved wallaby) within M. (Osphranter) rather than as expected, with M. (Notamacropus). Species tree estimation from separately analysed mitochondrial and nuclear genes favours retaining Macropus and Wallabia as separate genera. A simulation study finds that incomplete lineage sorting among nuclear genes is a plausible explanation for incongruence with the mitochondrial placement of W. bicolor, while mitochondrial introgression from a wallaroo into M. irma is the deepest such event identified in marsupials. Similar such coalescent simulations for interpreting gene tree conflicts will increase in both relevance and statistical power as species-level phylogenetics enters the genomic age. Ecological considerations in turn, hint at a role for selection in accelerating the fixation of introgressed or incompletely sorted loci. More generally the inclusion of the mitochondrial sequences substantially enhanced phylogenetic resolution. However, we caution that the evolutionary dynamics that enhance mitochondria as speciation indicators in the presence of incomplete lineage sorting may also render them especially susceptible to introgression.

  6. Adoption in eastern grey kangaroos: a consequence of misdirected care?

    PubMed

    King, Wendy J; Forsyth, David M; Coulson, Graeme; Festa-Bianchet, Marco

    2015-01-01

    Adoption is rare in animals and is usually attributed to kin selection. In a 6-year study of eastern grey kangaroos (Macropus giganteus), 11 of 326 juveniles were adopted. We detected eight adoptions by observing behavioural associations and nursing between marked mothers and young and three more by analysing the relatedness of mothers and young using microsatellite DNA. Four adoptions involved reciprocal switches and three were by mothers whose own pouch young were known to subsequently disappear. Adoptive mothers were not closely related to each other or to adoptees but adoptive mothers and young associated as closely as did biological pairs, as measured by half-weight indices. Switch mothers did not associate closely. Maternal age and body condition did not influence the likelihood of adoption but females were more likely to adopt in years with high densities of females with large pouch young. Adoption did not improve juvenile survival. We conclude that adoptions in this wild population were potentially costly and likely caused by misdirected care, suggesting that eastern grey kangaroos may have poorly developed mother-offspring recognition mechanisms.

  7. Adoption in Eastern Grey Kangaroos: A Consequence of Misdirected Care?

    PubMed Central

    King, Wendy J.; Forsyth, David M.; Coulson, Graeme; Festa-Bianchet, Marco

    2015-01-01

    Adoption is rare in animals and is usually attributed to kin selection. In a 6-year study of eastern grey kangaroos (Macropus giganteus), 11 of 326 juveniles were adopted. We detected eight adoptions by observing behavioural associations and nursing between marked mothers and young and three more by analysing the relatedness of mothers and young using microsatellite DNA. Four adoptions involved reciprocal switches and three were by mothers whose own pouch young were known to subsequently disappear. Adoptive mothers were not closely related to each other or to adoptees but adoptive mothers and young associated as closely as did biological pairs, as measured by half-weight indices. Switch mothers did not associate closely. Maternal age and body condition did not influence the likelihood of adoption but females were more likely to adopt in years with high densities of females with large pouch young. Adoption did not improve juvenile survival. We conclude that adoptions in this wild population were potentially costly and likely caused by misdirected care, suggesting that eastern grey kangaroos may have poorly developed mother-offspring recognition mechanisms. PMID:25970624

  8. Kangaroo rats change temperature when investigating rattlesnake predators.

    PubMed

    Schraft, Hannes A; Clark, Rulon W

    2017-02-08

    Predator presence causes acute stress in mammals. A prey animal's stress response increases its chance of survival during life-threatening situations through adaptive changes in behavior and physiology. Some components of the physiological stress response can lead to changes in body surface temperatures. Body temperature changes in prey could provide information about prey state to predators that sense heat, such as pit vipers. We determined whether wild rodents undergo a stress-induced change in body surface temperature upon detecting and investigating rattlesnake predators. We staged encounters between free-ranging Merriam's kangaroo rats (Dipodomys merriami) and tethered Mojave rattlesnakes (Crotalus scutulatus) at baited feeding stations, and recorded interactions with a thermal-imaging camera. Kangaroo rats showed a significant change in maximum head temperature, snout temperature, and hind leg temperature during interactions with rattlesnakes. This supports the hypothesis that presence of a predator induces body temperature changes in prey animals. If changes in prey heat signature are detectable by heat-sensitive rattlesnakes, rattlesnakes could use this information to evaluate prey vigilance or arousal before striking; however, more detailed information on the sensory ecology of the pit organ under field conditions is needed to evaluate this possibility.

  9. Seismic communication between the burrows of kangaroo rats, Dipodomys spectabilis.

    PubMed

    Randall, J A; Lewis, E R

    1997-11-01

    Banner-tailed kangaroo rats, Dipodomys spectabilis, footdrum to produce substrate-borne and airborne acoustic energy. Previous studies show that they communicate territorial ownership via airborne footdrumming signals. The research reported here used simulated footdrum patterns generated by an artificial 'thumper' to address the question of whether kangaroo rats communicate through seismic components of these acoustic signals. With microphones suspended in sealed burrows, we found that airborne sounds were attenuated by approximately 40 dB as they passed through the burrow wall into the burrow chamber. The substrate-borne vibrations from the thumper yielded sound approximately 40 dB greater in peak amplitude than the attenuated airborne sound. Thus, 99.9% of the peak power of the thumper was transmitted directly through the substrate into the burrow. The rats in sealed burrows timed their responses to playbacks of footdrums from the thumper and a loudspeaker so they did not initiate a drumming sequence during either the seismic or airborne signals. When these signals were masked by loud noise, the rats continued to drum to the seismic signal but drummed randomly during the airborne playback. These results suggest that the sealed burrow provides a quiet place in which D. spectabilis can listen for substrate-borne communications from conspecifics.

  10. Beaded-chain collars: A new method to radiotag kangaroo rats for short-term studies

    USGS Publications Warehouse

    Harker, M.B.; Rathbun, G.B.; Langtimm, C.A.

    1999-01-01

    To study burrow use by small mammals, we needed to develop a simple, non-invasive radiotag for the endangered giant kangaroo rat (Dipodomys ingens). We designed and tested a radiocollar made of beaded-chain on 4 captive Heermann's kangaroo rats (D. heermanii). Attachment of the collar required no anesthesia, the collar was easily fitted in 1-2 minutes, and it caused minimal stress to the animals. Once the collar design and attachment technique were perfected on the surrogate animals, we fitted radiocollars on 48 giant kangaroo rats for about 15 days. Upon recapture, 12 animals showed some minor fur or skin abrasion on the neck. Overall, the attachment performed as expected and proved to be a reliable method to radiotrack kangaroo rats during our short-term field study.

  11. Successful management of hypertrophic cardiomyopathy in a Matschie's tree kangaroo (Dendrolagus matschiei).

    PubMed

    Fredholm, Daniel V; Jones, Ashley E; Hall, Natalie H; Russell, Kathleen; Heard, Darryl J

    2015-03-01

    A 3-yr-old, intact male Matschie's tree kangaroo (Dendrolagus matschiei) was examined for a 1-wk history of intermittent lethargy and tachypnea. An echocardiogram revealed concentric hypertrophy of the left ventricular free wall and interventricular septum. These findings were compared to measurements from healthy Matschie's tree kangaroos, supporting a diagnosis of hypertrophic cardiomyopathy. At the time of publication, the patient has been managed for over 11.5 yr, using a combination of enalapril, furosemide, diltiazem, and diet modifications. Hypertrophic cardiomyopathy should be considered as a differential diagnosis in tree kangaroos exhibiting signs of cardiovascular or respiratory distress. This case represents the first report of antemortem diagnosis and successful management of hypertrophic cardiomyopathy in a Matschie's tree kangaroo.

  12. Locomotion in Extinct Giant Kangaroos: Were Sthenurines Hop-Less Monsters?

    PubMed Central

    Janis, Christine M.; Buttrill, Karalyn; Figueirido, Borja

    2014-01-01

    Sthenurine kangaroos (Marsupialia, Diprotodontia, Macropodoidea) were an extinct subfamily within the family Macropodidae (kangaroos and rat-kangaroos). These “short-faced browsers” first appeared in the middle Miocene, and radiated in the Plio-Pleistocene into a diversity of mostly large-bodied forms, more robust than extant forms in their build. The largest (Procoptodon goliah) had an estimated body mass of 240 kg, almost three times the size of the largest living kangaroos, and there is speculation whether a kangaroo of this size would be biomechanically capable of hopping locomotion. Previously described aspects of sthenurine anatomy (specialized forelimbs, rigid lumbar spine) would limit their ability to perform the characteristic kangaroo pentapedal walking (using the tail as a fifth limb), an essential gait at slower speeds as slow hopping is energetically unfeasible. Analysis of limb bone measurements of sthenurines in comparison with extant macropodoids shows a number of anatomical differences, especially in the large species. The scaling of long bone robusticity indicates that sthenurines are following the “normal” allometric trend for macropodoids, while the large extant kangaroos are relatively gracile. Other morphological differences are indicative of adaptations for a novel type of locomotor behavior in sthenurines: they lacked many specialized features for rapid hopping, and they also had anatomy indicative of supporting their body with an upright trunk (e.g., dorsally tipped ischiae), and of supporting their weight on one leg at a time (e.g., larger hips and knees, stabilized ankle joint). We propose that sthenurines adopted a bipedal striding gait (a gait occasionally observed in extant tree-kangaroos): in the smaller and earlier forms, this gait may have been employed as an alternative to pentapedal locomotion at slower speeds, while in the larger Pleistocene forms this gait may have enabled them to evolve to body sizes where hopping was

  13. Locomotion in extinct giant kangaroos: were sthenurines hop-less monsters?

    PubMed

    Janis, Christine M; Buttrill, Karalyn; Figueirido, Borja

    2014-01-01

    Sthenurine kangaroos (Marsupialia, Diprotodontia, Macropodoidea) were an extinct subfamily within the family Macropodidae (kangaroos and rat-kangaroos). These "short-faced browsers" first appeared in the middle Miocene, and radiated in the Plio-Pleistocene into a diversity of mostly large-bodied forms, more robust than extant forms in their build. The largest (Procoptodon goliah) had an estimated body mass of 240 kg, almost three times the size of the largest living kangaroos, and there is speculation whether a kangaroo of this size would be biomechanically capable of hopping locomotion. Previously described aspects of sthenurine anatomy (specialized forelimbs, rigid lumbar spine) would limit their ability to perform the characteristic kangaroo pentapedal walking (using the tail as a fifth limb), an essential gait at slower speeds as slow hopping is energetically unfeasible. Analysis of limb bone measurements of sthenurines in comparison with extant macropodoids shows a number of anatomical differences, especially in the large species. The scaling of long bone robusticity indicates that sthenurines are following the "normal" allometric trend for macropodoids, while the large extant kangaroos are relatively gracile. Other morphological differences are indicative of adaptations for a novel type of locomotor behavior in sthenurines: they lacked many specialized features for rapid hopping, and they also had anatomy indicative of supporting their body with an upright trunk (e.g., dorsally tipped ischiae), and of supporting their weight on one leg at a time (e.g., larger hips and knees, stabilized ankle joint). We propose that sthenurines adopted a bipedal striding gait (a gait occasionally observed in extant tree-kangaroos): in the smaller and earlier forms, this gait may have been employed as an alternative to pentapedal locomotion at slower speeds, while in the larger Pleistocene forms this gait may have enabled them to evolve to body sizes where hopping was no longer

  14. Nurses' adherence to the Kangaroo Care Method: support for nursing care management1

    PubMed Central

    da Silva, Laura Johanson; Leite, Josete Luzia; Scochi, Carmen Gracinda Silvan; da Silva, Leila Rangel; da Silva, Thiago Privado

    2015-01-01

    OBJECTIVE: construct an explanatory theoretical model about nurses' adherence to the Kangaroo Care Method at the Neonatal Intensive Care Unit, based on the meanings and interactions for care management. METHOD: qualitative research, based on the reference framework of the Grounded Theory. Eight nurses were interviewed at a Neonatal Intensive Care Unit in the city of Rio de Janeiro. The comparative analysis of the data comprised the phases of open, axial and selective coding. A theoretical conditional-causal model was constructed. RESULTS: four main categories emerged that composed the analytic paradigm: Giving one's best to the Kangaroo Method; Working with the complexity of the Kangaroo Method; Finding (de)motivation to apply the Kangaroo Method; and Facing the challenges for the adherence to and application of the Kangaroo Method. CONCLUSIONS: the central phenomenon revealed that each nurse and team professional has a role of multiplying values and practices that may or may not be constructive, potentially influencing the (dis)continuity of the Kangaroo Method at the Neonatal Intensive Care Unit. The findings can be used to outline management strategies that go beyond the courses and training and guarantee the strengthening of the care model. PMID:26155013

  15. Glutaraldehyde-fixed kangaroo aortic wall tissue: histology, crosslink stability and calcification potential.

    PubMed

    Neethling, W M L; Hodge, A J; Glancy, R

    2003-07-15

    Stentless aortic heart valve substitutes, manufactured from biological tissues, are fixed with glutaraldehyde to cross-link collagen, reduce antigenicity, and sterilize the tissue. Despite improved cross linking, reduced antigenicity, and various anticalcification measures, the aortic wall tissue present in these prostheses tends to calcify. The aim of this study was to assess the morphology, collagen cross-link stability, and calcification potential of glutaraldehyde-preserved kangaroo aortic wall tissue as opposed to porcine aortic wall tissue. Porcine and kangaroo aortic wall tissues were fixed in 0.625% buffered glutaraldehyde. Histology and cross-link stability were examined. Calcification potential was determined in the subcutaneous rat model. Kangaroo aortic wall tissue was significantly (p < 0.01) less calcified than porcine aortic wall tissue (26.67 +/- 6.53 versus 41.959 +/- 2.75 microg/mg tissue) at 8 weeks. In conclusion, the histological differences between kangaroo and porcine aortic wall tissue correlate well with the reduced calcification potential of kangaroo aortic wall tissue. The reduced calcification potential could result in improved long-term durability of stentless kangaroo heart valves as bioprostheses.

  16. Merriam's kangaroo rats (Dipodomys merriami) voluntarily select temperatures that conserve energy rather than water.

    PubMed

    Banta, Marilyn R

    2003-01-01

    Desert endotherms such as Merriam's kangaroo rat (Dipodomys merriami) use both behavioral and physiological means to conserve energy and water. The energy and water needs of kangaroo rats are affected by their thermal environment. Animals that choose temperatures within their thermoneutral zone (TNZ) minimize energy expenditure but may impair water balance because the ratio of water loss to water gain is high. At temperatures below the TNZ, water balance may be improved because animals generate more oxidative water and reduce evaporative water loss; however, they must also increase energy expenditure to maintain a normal body temperature. Hence, it is not possible for kangaroo rats to choose thermal environments that simultaneously minimize energy expenditure and increase water conservation. I used a thermal gradient to test whether water stress, energy stress, simultaneous water and energy stress, or no water/energy stress affected the thermal environment selected by D. merriami. During the night (i.e., active phase), animals in all four treatments chose temperatures near the bottom of their TNZ. During the day (i.e., inactive phase), animals in all four treatments settled at temperatures near the top of their TNZ. Thus, kangaroo rats chose thermal environments that minimized energy requirements, not water requirements. Because kangaroo rats have evolved high water use efficiency, energy conservation may be more important than water conservation to the fitness of extant kangaroo rats.

  17. The effect of kangaroo care on neurodevelopmental outcomes in preterm infants.

    PubMed

    Head, Lauren M

    2014-01-01

    Preterm birth is associated with long-term deficits in executive functioning and cognitive performance. As advances in neonatal care enable more preterm infants to survive, development of strategies to address high rates of neurodevelopmental disabilities and poor academic achievement in preterm infants are crucial. Evidence suggests that infants' brains are plastic in nature and, therefore, can be shaped by the environment. Kangaroo care has become popularized as a means of modifying the stress of the NICU environment. However, few studies have examined whether kangaroo care affects neurodevelopmental outcomes in preterm infants. This review examined available literature that investigated the effect of kangaroo care on cognition in preterm infants. Current evidence suggests that short-term benefits of kangaroo care are associated with improved neurodevelopment. However, few studies have examined the long-term impact of kangaroo care on cognitive outcomes in preterm infants. To address neurological disparities in children born preterm, research using kangaroo care as a strategy to improve neurodevelopment in preterm infants is warranted.

  18. [Humane care for low-weight newborns (kangaroo mother method): mother's perceptions].

    PubMed

    Neves, Priscila Nicoletti; Ravelli, Ana Paula Xavier; Lemos, Juliana Regina Dias

    2010-03-01

    Breastfeeding is one of the key practices which promote health, being associated with a reduction of diseases and mortality in childhood. Thus, from the course conclusive work, the present article was structured, which aimed to recognize the perceptions of mothers in the face of the use of the mother kangaroo method. With a qualitative, descriptive and field approach, it was held at the Philanthropic Hospital of Ponta Grossa, Paraná, Brazil, by the months of August to October 2006, in which six mothers were included in the kangaroo mother method during the admission of the baby. For the gathering, semi-structured interviews were made and data were analyzed by the content analysis. This article analyzed two categories, maternal experience with the mother kangaroo method, with the subcategories: mother kangaroo method and maternal breastfeeding and experiences at the kangaroo practice; and knowing the kangaroo method. As a conclusion, nursing plays an essential role in the insertion of the family to the method, from the provided cares.

  19. Boundary-layer turbulence as a kangaroo process

    NASA Astrophysics Data System (ADS)

    Dekker, H.; de Leeuw, G.; Maassen van den Brink, A.

    1995-09-01

    A nonlocal mixing-length theory of turbulence transport by finite size eddies is developed by means of a novel evaluation of the Reynolds stress. The analysis involves the contruct of a sample path space and a stochastic closure hypothesis. The simplifying property of exhange (strong eddies) is satisfied by an analytical sampling rate model. A nonlinear scaling relation maps the path space onto the semi-infinite boundary layer. The underlying near-wall behavior of fluctuating velocities perfectly agrees with recent direct numerical simulations. The resulting integro-differential equation for the mixing of scalar densities represents fully developed boundary-layer turbulence as a nondiffusive (Kubo-Anderson or kangaroo) type of stochastic process. The model involves a scaling exponent ɛ (with ɛ-->∞ in the diffusion limit). For the (partly analytical) solution for the mean velocity profile, excellent agreement with the experimental data yields ɛ~=0.58.

  20. Virtopsy in a red kangaroo with oral osteomyelitis.

    PubMed

    Lee, Ki-Ja; Sasaki, Motoki; Miyauchi, Aki; Kishimoto, Miori; Shimizu, Junichiro; Iwasaki, Toshiroh; Miyake, Yoh-Ichi; Yamada, Kazutaka

    2011-03-01

    This report describes the use of computed tomography (CT) in a nondomestic species. Postmortem CT was performed on a red kangaroo (Macropus rufus) and a diagnosis of oral osteomyelitis was made. CT examination revealed bony remodeling of the right mandible, an intraosseous lesion of the right temporal bone, muscle necrosis around the right mandible, and the absence of the right, first, upper molar tooth. Cardiac and intrahepatic gas and a distended intestine due to postmortem gas accumulation were also seen. All the lesions identified with CT were also identified by conventional necropsy, except the cardiac and intrahepatic gases. Virtopsy may be a useful procedure for the noninvasive identification of cause of death and as a guide for necropsy in animals.

  1. Calcium carbonate obstructive urolithiasis in a red kangaroo (Macropus rufus).

    PubMed

    Lindemann, Dana M; Gamble, Kathryn C; Corner, Sarah

    2013-03-01

    A 6-yr-old male red kangaroo (Macropus rufus) presented for a history of inappetance, abnormal behavior, and unconfirmed elimination for 6 hr prior to presentation. Based on abdominal ultrasound, abdominocentesis, and cystocentesis, a presumptive diagnosis of urinary tract obstruction with uroabdomen and hydronephrosis was reached. Abdominal radiographs did not assist in reaching an antemortem diagnosis. Postmortem examination confirmed a urinary bladder rupture secondary to urethral obstruction by a single urethrolith. Bilateral hydronephrosis and hydroureter were identified and determined to be a result of bilateral ureteroliths. Urolith analysis revealed a composition of 100% calcium carbonate. A dietary analysis was performed, implicating an increased Ca:P ratio from a food preparation miscommunication as a contributing factor. Appropriate husbandry changes were made, and mob surveillance procedures were performed, which resolved the urolithiasis risk for the remaining five animals.

  2. Kangaroo care for the preterm infant and family.

    PubMed

    Jefferies, Ann L

    2012-03-01

    Kangaroo care (KC) is the practice of skin-to-skin contact between infant and parent. In developing countries, KC for low-birthweight infants has been shown to reduce mortality, severe illness, infection and length of hospital stay. KC is also beneficial for preterm infants in high-income countries. Cardiorespiratory and temperature stability, sleep organization and duration of quiet sleep, neurodevelopmental outcomes, breastfeeding and modulation of pain responses appear to be improved for preterm infants who have received KC during their hospital stay. No detrimental effects on physiological stability have been demonstrated for infants as young as 26 weeks' gestational age, including those on assisted ventilation. Mothers show enhanced attachment behaviours and describe an increased sense of their role as a mother. The practice of KC should be encouraged in nurseries that care for preterm infants. Information is available to assist in developing guidelines and protocols.

  3. Spatial requirements of free-ranging Huon tree kangaroos, Dendrolagus matschiei (Macropodidae), in upper montane forest.

    PubMed

    Porolak, Gabriel; Dabek, Lisa; Krockenberger, Andrew K

    2014-01-01

    Tree kangaroos (Macropodidae, Dendrolagus) are some of Australasia's least known mammals. However, there is sufficient evidence of population decline and local extinctions that all New Guinea tree kangaroos are considered threatened. Understanding spatial requirements is important in conservation and management. Expectations from studies of Australian tree kangaroos and other rainforest macropodids suggest that tree kangaroos should have small discrete home ranges with the potential for high population densities, but there are no published estimates of spatial requirements of any New Guinea tree kangaroo species. Home ranges of 15 Huon tree kangaroos, Dendrolagus matschiei, were measured in upper montane forest on the Huon Peninsula, Papua New Guinea. The home range area was an average of 139.6±26.5 ha (100% MCP; n = 15) or 81.8±28.3 ha (90% harmonic mean; n = 15), and did not differ between males and females. Home ranges of D. matschiei were 40-100 times larger than those of Australian tree kangaroos or other rainforest macropods, possibly due to the impact of hunting reducing density, or low productivity of their high altitude habitat. Huon tree kangaroos had cores of activity within their range at 45% (20.9±4.1 ha) and 70% (36.6±7.5 ha) harmonic mean isopleths, with little overlap (4.8±2.9%; n = 15 pairs) between neighbouring females at the 45% isopleth, but, unlike the Australian species, extensive overlap between females (20.8±5.5%; n = 15 pairs) at the complete range (90% harmonic mean). Males overlapped each other and females to a greater extent than did pairs of females. From core areas and overlap, the density of female D. matschiei was one per 19.4 ha. Understanding the cause of this low density is crucial in gaining greater understanding of variations in density of tree kangaroos across the landscape. We consider the potential role of habitat fragmentation, productivity and hunting pressure in limiting tree kangaroo density in New

  4. Positive interactions between desert granivores: localized facilitation of harvester ants by kangaroo rats.

    PubMed

    Edelman, Andrew J

    2012-01-01

    Facilitation, when one species enhances the environment or performance of another species, can be highly localized in space. While facilitation in plant communities has been intensely studied, the role of facilitation in shaping animal communities is less well understood. In the Chihuahuan Desert, both kangaroo rats and harvester ants depend on the abundant seeds of annual plants. Kangaroo rats, however, are hypothesized to facilitate harvester ants through soil disturbance and selective seed predation rather than competing with them. I used a spatially explicit approach to examine whether a positive or negative interaction exists between banner-tailed kangaroo rat (Dipodomys spectabilis) mounds and rough harvester ant (Pogonomyrmex rugosus) colonies. The presence of a scale-dependent interaction between mounds and colonies was tested by comparing fitted spatial point process models with and without interspecific effects. Also, the effect of proximity to a mound on colony mortality and spatial patterns of surviving colonies was examined. The spatial pattern of kangaroo rat mounds and harvester ant colonies was consistent with a positive interspecific interaction at small scales (<10 m). Mortality risk of vulnerable, recently founded harvester ant colonies was lower when located close to a kangaroo rat mound and proximity to a mound partly predicted the spatial pattern of surviving colonies. My findings support localized facilitation of harvester ants by kangaroo rats, likely mediated through ecosystem engineering and foraging effects on plant cover and composition. The scale-dependent effect of kangaroo rats on abiotic and biotic factors appears to result in greater founding and survivorship of young colonies near mounds. These results suggest that soil disturbance and foraging by rodents can have subtle impacts on the distribution and demography of other species.

  5. Botfly (Diptera:Oestridae) parasitism of Ord's kangaroo rats (Dipodomys ordii) at Suffield National Wildlife Area, Alberta, Canada.

    PubMed

    Gummer, D L; Forbes, M R; Bender, D J; Barclay, R M

    1997-08-01

    During field study of Ord's kangaroo rat (Dipodomys ordii) at Suffield National Wildlife Area, Alberta, Canada, a high prevalence of parasitism by botfly (Diptera: Oestridae) larvae was observed. Botflies have not previously been documented as parasites of kangaroo rats. Botfly parasitism could have a significant impact on the growth, survival, and reproduction of Ord's kangaroo rat, which is considered a vulnerable species in Canada. Therefore, it is important to investigate how botfly parasitism varies with season and with gender or age of host. In 1995, 525 individual kangaroo rats were caught by nightlighting and live trapping for a total of 952 capture records. Upon capture, each kangaroo rat was ear-tagged and thoroughly examined for parasites and wounds. Third-instar botfly (Cuterebra polita) larvae were observed in kangaroo rats between 16 June and 23 August. Prevalence was 34% based on 454 kangaroo rats sampled during that time, whereas the mean intensity was 2.3 larvae per infested host (n = 156, range = 1-11). In contrast to some other studies of botfly parasitism of rodents, there were no gender or age biases in either prevalence or intensity of infestation. The index of dispersion was 2.8, indicating that the parasites were aggregated in hosts. Botfly parasitism could be an important factor affecting northern populations of kangaroo rats; future investigations into the potential effects of botfly larvae on host fitness are warranted.

  6. Electromyographic activity of preterm newborns in the kangaroo position: a cohort study

    PubMed Central

    Miranda, Rafael Moura; Cabral Filho, José Eulálio; Diniz, Kaísa Trovão; Souza Lima, Geisy Maria; Vasconcelos, Danilo de Almeida

    2014-01-01

    Objective To compare the electromyographic activity of preterm newborns placed in the kangaroo position with the activity of newborns not placed in this position. Design A cohort study. Setting A Kangaroo Unit sector and a Nursery sector in a secondary and tertiary care at a mother-child hospital in Recife, Brazil. Participants Preterm infants of gestational age 27–34 weeks (n=38) and term infants (n=39). Primary and secondary outcome measures Surface electromyography was used to investigate muscle activity in the brachial biceps at rest. 3 groups were designed: (1) preterm newborns in the kangaroo position (PT-KAN), where the newborn remains in a vertical position, lying face down, with limbs flexed, dressed in light clothes, maintaining skin-to-skin contact with the adult's thorax. Her electromyographic activity was recorded at 0 h (immediately before starting this position), and then at 48 h after the beginning of the position (but newborns were kept in the kangaroo position for 8–12 h per day) and at term equivalent age (40±1 weeks); (2) preterm newborns not in the kangaroo position (PT-NKAN), in which measurements were made at 0 h and 48 h; and (3) term newborns (T), in which measurements were made at 24 h of chronological age. Results The Root Mean Square (RMS) values showed significant differences among groups (F(5,108)=56.69; p<0.001). The multiple comparisons showed that RMS was greater at 48 h compared to 0 h in the preterm group in the kangaroo position, but not in the group not submitted in the kangaroo position. The RMS in the term equivalent aged group in the kangaroo position was also greater when compared with those in the term group. Conclusions The kangaroo position increases electromyographic activity in the brachial biceps of preterm newborns and those who have reached the age equivalent to term. PMID:25351598

  7. Decreasing methane yield with increasing food intake keeps daily methane emissions constant in two foregut fermenting marsupials, the western grey kangaroo and red kangaroo.

    PubMed

    Vendl, Catharina; Clauss, Marcus; Stewart, Mathew; Leggett, Keith; Hummel, Jürgen; Kreuzer, Michael; Munn, Adam

    2015-11-01

    Fundamental differences in methane (CH4) production between macropods (kangaroos) and ruminants have been suggested and linked to differences in the composition of the forestomach microbiome. Using six western grey kangaroos (Macropus fuliginosus) and four red kangaroos (Macropus rufus), we measured daily absolute CH4 production in vivo as well as CH4 yield (CH4 per unit of intake of dry matter, gross energy or digestible fibre) by open-circuit respirometry. Two food intake levels were tested using a chopped lucerne hay (alfalfa) diet. Body mass-specific absolute CH4 production resembled values previously reported in wallabies and non-ruminant herbivores such as horses, and did not differ with food intake level, although there was no concomitant proportionate decrease in fibre digestibility with higher food intake. In contrast, CH4 yield decreased with increasing intake, and was intermediate between values reported for ruminants and non-ruminant herbivores. These results correspond to those in ruminants and other non-ruminant species where increased intake (and hence a shorter digesta retention in the gut) leads to a lower CH4 yield. We hypothesize that rather than harbouring a fundamentally different microbiome in their foregut, the microbiome of macropods is in a particular metabolic state more tuned towards growth (i.e. biomass production) rather than CH4 production. This is due to the short digesta retention time in macropods and the known distinct 'digesta washing' in the gut of macropods, where fluids move faster than particles and hence most likely wash out microbes from the forestomach. Although our data suggest that kangaroos only produce about 27% of the body mass-specific volume of CH4 of ruminants, it remains to be modelled with species-specific growth rates and production conditions whether or not significantly lower CH4 amounts are emitted per kg of meat in kangaroo than in beef or mutton production.

  8. Draft De Novo Transcriptome of the Rat Kangaroo Potorous tridactylus as a Tool for Cell Biology

    PubMed Central

    Udy, Dylan B.; Voorhies, Mark; Chan, Patricia P.; Lowe, Todd M.; Dumont, Sophie

    2015-01-01

    The rat kangaroo (long-nosed potoroo, Potorous tridactylus) is a marsupial native to Australia. Cultured rat kangaroo kidney epithelial cells (PtK) are commonly used to study cell biological processes. These mammalian cells are large, adherent, and flat, and contain large and few chromosomes—and are thus ideal for imaging intra-cellular dynamics such as those of mitosis. Despite this, neither the rat kangaroo genome nor transcriptome have been sequenced, creating a challenge for probing the molecular basis of these cellular dynamics. Here, we present the sequencing, assembly and annotation of the draft rat kangaroo de novo transcriptome. We sequenced 679 million reads that mapped to 347,323 Trinity transcripts and 20,079 Unigenes. We present statistics emerging from transcriptome-wide analyses, and analyses suggesting that the transcriptome covers full-length sequences of most genes, many with multiple isoforms. We also validate our findings with a proof-of-concept gene knockdown experiment. We expect that this high quality transcriptome will make rat kangaroo cells a more tractable system for linking molecular-scale function and cellular-scale dynamics. PMID:26252667

  9. Draft De Novo Transcriptome of the Rat Kangaroo Potorous tridactylus as a Tool for Cell Biology.

    PubMed

    Udy, Dylan B; Voorhies, Mark; Chan, Patricia P; Lowe, Todd M; Dumont, Sophie

    2015-01-01

    The rat kangaroo (long-nosed potoroo, Potorous tridactylus) is a marsupial native to Australia. Cultured rat kangaroo kidney epithelial cells (PtK) are commonly used to study cell biological processes. These mammalian cells are large, adherent, and flat, and contain large and few chromosomes-and are thus ideal for imaging intra-cellular dynamics such as those of mitosis. Despite this, neither the rat kangaroo genome nor transcriptome have been sequenced, creating a challenge for probing the molecular basis of these cellular dynamics. Here, we present the sequencing, assembly and annotation of the draft rat kangaroo de novo transcriptome. We sequenced 679 million reads that mapped to 347,323 Trinity transcripts and 20,079 Unigenes. We present statistics emerging from transcriptome-wide analyses, and analyses suggesting that the transcriptome covers full-length sequences of most genes, many with multiple isoforms. We also validate our findings with a proof-of-concept gene knockdown experiment. We expect that this high quality transcriptome will make rat kangaroo cells a more tractable system for linking molecular-scale function and cellular-scale dynamics.

  10. Natural space-use patterns and hippocampal size in kangaroo rats.

    PubMed

    Jacobs, L F; Spencer, W D

    1994-01-01

    The size of the hippocampus, a forebrain structure that processes spatial information, correlates with the need to relocate food caches by passerine birds and with sex-specific patterns of space use in microtine rodents. The influences on hippocampal anatomy of sexual selection within species, and natural selection between species, have not yet been studied in concert, however. Here we report that natural space-use patterns predict hippocampal size within and between two species of kangaroo rats (Dipodomys). Differences in foraging behavior suggest that Merriam's kangaroo rats (D. merriami) require better spatial abilities than bannertail kangaroo rats (D. spectabilis). Sex-specific differences in mating strategy suggest that males of both species require more spatial ability than females. As predicted, hippocampal size (relative to brain size) is larger in Merriam's than in bannertail kangaroo rats, and males have larger hippocampi than females in both species. Males of a third species (D. ordii) also have smaller hippocampi than Merriam's kangaroo rat males, despite being similar to Merriam's in brain and body size. These results suggest that both natural and sexual selection affect the relative size and perhaps function of mammalian hippocampi. They also reassert that measures of functional subunits of the brain reveal more about brain evolution than measures of total brain size.

  11. Gammaherpesvirus infection in a free-ranging eastern grey kangaroo (Macropus giganteus).

    PubMed

    Wilcox, R S; Vaz, P; Ficorilli, N P; Whiteley, P L; Wilks, C R; Devlin, J M

    2011-01-01

    A gammaherpesvirus was detected by polymerase chain reaction (PCR) in ocular, nasal and oropharyngeal swab samples collected from an adult free-ranging male eastern grey kangaroo (Macropus giganteus) with clinical signs of severe respiratory disease. This is the first time a gammaherpesvirus has been detected in a free-ranging macropod in Australia. The nucleotide sequence of a conserved region of the DNA polymerase gene of the detected virus showed a high degree of identity to a gammaherpesvirus recently detected in a zoological collection of eastern grey kangaroos in North America. The detection of this gammaherpesvirus in a free-ranging, native eastern grey kangaroo provides evidence that this species is a natural host.

  12. Physical mechanisms underlying the strain-rate-dependent mechanical behavior of kangaroo shoulder cartilage

    NASA Astrophysics Data System (ADS)

    Thibbotuwawa, Namal; Oloyede, Adekunle; Li, Tong; Singh, Sanjleena; Senadeera, Wijitha; Gu, YuanTong

    2015-09-01

    Due to anatomical and biomechanical similarities to human shoulder, kangaroo was chosen as a model to study shoulder cartilage. Comprehensive enzymatic degradation and indentation tests were applied on kangaroo shoulder cartilage to study mechanisms underlying its strain-rate-dependent mechanical behavior. We report that superficial collagen plays a more significant role than proteoglycans in facilitating strain-rate-dependent behavior of the kangaroo shoulder cartilage. By comparing the mechanical properties of degraded and normal cartilages, it was noted that proteoglycan and collagen degradation significantly compromised strain-rate-dependent mechanical behavior of the cartilage. Superficial collagen contributed equally to the tissue behavior at all strain-rates. This is different to the studies reported on knee cartilage and confirms the importance of superficial collagen on shoulder cartilage mechanical behavior. A porohyperelastic numerical model also indicated that collagen disruption would lead to faster damage of the shoulder cartilage than when proteoglycans are depleted.

  13. Cache decision making: the effects of competition on cache decisions in Merriam's kangaroo rat (Dipodomys merriami).

    PubMed

    Preston, Stephanie D; Jacobs, Lucia F

    2005-05-01

    Caching food is an economic, decision-making process that requires animals to take many factors into account, including the risk of pilferage. However, little is known about how food-storing animals determine the risk of pilferage. In this study, the authors examined the effect of a dominant competitor species on the caching and behavior of Merriam's kangaroo rat (Dipodomys merriami). The authors found that, as with conspecific competitors, kangaroo rats did not alter caching in response to the mere presence of a heterospecific competitor, but moved caches to an unpreferred area when the competitor's presence was paired with pilferage. These data suggest that Merriam's kangaroo rat assesses pilfer risk from actual pilferage by a competitor and adaptively alters cache strategy to minimize future risk.

  14. Chihuahuan Desert kangaroo rats: nonlinear effects of population dynamics, competition, and rainfall.

    PubMed

    Lima, Mauricio; Ernest, S K Morgan; Brown, James H; Belgrano, Andrea; Stenseth, Nils C

    2008-09-01

    Using long-term data on two kangaroo rats in the Chihuahuan Desert of North America, we fitted logistic models including the exogenous effects of seasonal rainfall patterns. Our aim was to test the effects of intraspecific interactions and seasonal rainfall in explaining and predicting the numerical fluctuations of these two kangaroo rats. We found that logistic models fit both data sets quite well; Dipodomys merriami showed lower maximum per capita growth rates than Dipodomys ordii, and in both cases logistic models were nonlinear. Summer rainfall appears to be the most important exogenous effect for both rodent populations; models including this variable were able to predict independent data better than models including winter rainfall. D. merriami was also negatively affected by another kangaroo rat (Dipodomys spectabilis), consistent with previous experimental evidence. We hypothesized that summer rainfall influences the carrying capacity of the environment by affecting seed availability and the intensity of intraspecific competition.

  15. Prevalence of cutaneous evaporation in Merriam's kangaroo rat and its adaptive variation at the subspecific level.

    PubMed

    Tracy, R L; Walsberg, G E

    2000-02-01

    Previous estimates suggested that ventilatory evaporation constitutes the major source of water loss in kangaroo rats (Dipodomys spp.). We quantified rates of water loss in Merriam's kangaroo rat (Dipodomys merriami) and demonstrate the degree to which acclimation to a particular thermal and hydric environment plays a role in the intraspecific variation in water loss evident in this species. We draw the following conclusions: (1) that water loss varies intraspecifically in Merriam's kangaroo rat, in association with habitats of contrasting aridity and temperature; (2) that animals from more xeric locations have lower water loss rates than those from more mesic sites; (3) that most water loss is cutaneous, with ventilatory evaporative water loss contributing, at most, only 44% to total evaporative water loss; and (4) that intraspecific differences in rates of water loss are not acclimatory, but fixed. After acclimating under the same conditions, xeric-site animals still show a 33% lower rate of evaporative water loss than mesic-site animals.

  16. Effects of Kangaroo Care on Neonatal Pain in South Korea.

    PubMed

    Seo, Young Sun; Lee, Joohyun; Ahn, Hye Young

    2016-06-01

    Blood sampling for a newborn screening test is necessary for all neonates in South Korea. During the heel stick, an appropriate intervention should be implemented to reduce neonatal pain. This study was conducted to identify the effectiveness of kangaroo care (KC), skin contact with the mother, on pain relief during the neonatal heel stick. Twenty-six neonates undergoing KC and 30 control neonates at a university hospital participated in this study. Physiological responses of neonates, including heart rate, oxygen saturation, duration of crying and Premature Infant Pain Profile (PIPP) scores were measured and compared before, during and 1 min and 2 min after heel sticks. The heart rate of KC neonates was lower at both 1 and 2 min after sampling than those of the control group. Also, PIPP scores of KC neonates were significantly lower both during and after sampling. The duration of crying for KC neonates was around 10% of the duration of the control group. In conclusion, KC might be an effective intervention in a full-term nursery for neonatal pain management.

  17. Bilateral lens luxation and intracapsular lens extractions in a Matshchie's tree kangaroo.

    PubMed

    McLean, Nancy Johnstone; Zimmerman, Ralph

    2015-01-01

    An adult, female, captive, Matshchie's tree kangaroo was diagnosed with an anterior lens luxation in the right eye and a lens subluxation in the left eye. Both eyes were treated surgically with intracapsular lens extractions. A 360° rhegmatogenous retinal detachment was diagnosed 6 months postoperatively in the left eye. Aphakic vision was maintained in the right eye 9 months postoperatively. Based on family history and the lack of antecedent ocular disease, the lens luxations were presumed to be inherited and veterinarians should be aware of this condition within the captive tree kangaroo population.

  18. Kangaroo mother care may help oral growth and development in premature infants.

    PubMed

    Zhang, Feng; Liu, Shoutao

    2012-08-01

    Premature infants have a shorter prenatal development period and are prone to many serious medical problems during neonatal period. This may impact the development of oral tissues, as manifested by enamel hypoplasia, palatal distortion, malocclusion, or delay in tooth eruption and maturation. Kangaroo mother care (KMC) is a standardized and protocol-based care system for premature infants, based on skin-to-skin contact between the infant and their mother. Kangaroo mother care has been demonstrated to greatly improve the nurturing of premature infants and comparatively reduce the risk factors of oral defects. We hypothesize that KMC also facilitates oral growth and development in premature infants.

  19. Investigation of the microbial metabolism of carbon dioxide and hydrogen in the kangaroo foregut by stable isotope probing.

    PubMed

    Godwin, Scott; Kang, Alicia; Gulino, Lisa-Maree; Manefield, Mike; Gutierrez-Zamora, Maria-Luisa; Kienzle, Marco; Ouwerkerk, Diane; Dawson, Kerri; Klieve, Athol V

    2014-09-01

    Kangaroos ferment forage material in an enlarged forestomach analogous to the rumen, but in contrast to ruminants, they produce little or no methane. The objective of this study was to identify the dominant organisms and pathways involved in hydrogenotrophy in the kangaroo forestomach, with the broader aim of understanding how these processes are able to predominate over methanogenesis. Stable isotope analysis of fermentation end products and RNA stable isotope probing (RNA-SIP) were used to investigate the organisms and biochemical pathways involved in the metabolism of hydrogen and carbon dioxide in the kangaroo forestomach. Our results clearly demonstrate that the activity of bacterial reductive acetogens is a key factor in the reduced methane output of kangaroos. In in vitro fermentations, the microbial community of the kangaroo foregut produced very little methane, but produced a significantly greater proportion of acetate derived from carbon dioxide than the microbial community of the bovine rumen. A bacterial operational taxonomic unit closely related to the known reductive acetogen Blautia coccoides was found to be associated with carbon dioxide and hydrogen metabolism in the kangaroo foregut. Other bacterial taxa including members of the genera Prevotella, Oscillibacter and Streptococcus that have not previously been reported as containing hydrogenotrophic organisms were also significantly associated with metabolism of hydrogen and carbon dioxide in the kangaroo forestomach.

  20. Investigation of the microbial metabolism of carbon dioxide and hydrogen in the kangaroo foregut by stable isotope probing

    PubMed Central

    Godwin, Scott; Kang, Alicia; Gulino, Lisa-Maree; Manefield, Mike; Gutierrez-Zamora, Maria-Luisa; Kienzle, Marco; Ouwerkerk, Diane; Dawson, Kerri; Klieve, Athol V

    2014-01-01

    Kangaroos ferment forage material in an enlarged forestomach analogous to the rumen, but in contrast to ruminants, they produce little or no methane. The objective of this study was to identify the dominant organisms and pathways involved in hydrogenotrophy in the kangaroo forestomach, with the broader aim of understanding how these processes are able to predominate over methanogenesis. Stable isotope analysis of fermentation end products and RNA stable isotope probing (RNA-SIP) were used to investigate the organisms and biochemical pathways involved in the metabolism of hydrogen and carbon dioxide in the kangaroo forestomach. Our results clearly demonstrate that the activity of bacterial reductive acetogens is a key factor in the reduced methane output of kangaroos. In in vitro fermentations, the microbial community of the kangaroo foregut produced very little methane, but produced a significantly greater proportion of acetate derived from carbon dioxide than the microbial community of the bovine rumen. A bacterial operational taxonomic unit closely related to the known reductive acetogen Blautia coccoides was found to be associated with carbon dioxide and hydrogen metabolism in the kangaroo foregut. Other bacterial taxa including members of the genera Prevotella, Oscillibacter and Streptococcus that have not previously been reported as containing hydrogenotrophic organisms were also significantly associated with metabolism of hydrogen and carbon dioxide in the kangaroo forestomach. PMID:24621520

  1. An investigation of the topography of the lymphatic system of the grey kangaroo (Macropus giganteus). 1. The superficial lymphatic system.

    PubMed Central

    Hopwood, P R

    1988-01-01

    The superficial lymphatic system of the grey kangaroo, Macropus giganteus is described. The description is based on dissections of 130 eastern grey kangaroos. The most significant difference found between the superficial lymphatic drainage pattern of kangaroos and that of the domestic species was the existence of large inguino-axillary lymphatic trunks in the kangaroo. Thus in the kangaroo, instead of lymph passing from the inguinal lymphocentre to the lumbar lymphatic trunks as is the situation in the domestic animals, lymph passes from the inguinal lymphocentre to the axillary lymphocentre. Apart from the lymph draining from the head and ventral neck (which passes to the superficial cervical lymphocentre) and lymph which may pass from the superficial lymphatic vessels to deeper lymphatic vessels, all the superficial lymphatic drainage of the kangaroo passes through the axillary lymphocentre. From the viewpoint of the meat inspection of the carcasses of kangaroos taken as game meat animals, pathology of the axillary lymphocentre may reflect disease in a much wider range of body regions than it would in a domestic animal. PMID:3198478

  2. Persistent Persister Misperceptions

    PubMed Central

    Kim, Jun-Seob; Wood, Thomas K.

    2016-01-01

    Persister cells survive antibiotic treatment due to their lack of metabolism, rather than through genetic change, as shown via four seminal experiments conducted by the discoverers of the phenotype (Hobby et al., 1942; Bigger, 1944). Unfortunately, over seven decades of persister cell research, the literature has been populated by misperceptions that do not withstand scrutiny. This opinion piece examines some of those misunderstandings in the literature with the hope that by shining some light on these inaccuracies, the field may be advanced and subsequent manuscripts may be reviewed more critically. PMID:28082974

  3. Modeling interpopulation dispersal by banner-tailed kangaroo rats

    USGS Publications Warehouse

    Skvarla, J.L.; Nichols, J.D.; Hines, J.E.; Waser, P.M.

    2004-01-01

    Many metapopulation models assume rules of population connectivity that are implicitly based on what we know about within-population dispersal, but especially for vertebrates, few data exist to assess whether interpopulation dispersal is just within-population dispersal "scaled up." We extended existing multi-stratum mark-release-recapture models to incorporate the robust design, allowing us to compare patterns of within- and between-population movement in the banner-tailed kangaroo rat (Dipodomys spectabilis). Movement was rare among eight populations separated by only a few hundred meters: seven years of twice-annual sampling captured >1200 individuals but only 26 interpopulation dispersers. We developed a program that implemented models with parameters for capture, survival, and interpopulation movement probability and that evaluated competing hypotheses in a model selection framework. We evaluated variants of the island, stepping-stone, and isolation-by-distance models of interpopulation movement, incorporating effects of age, season, and habitat (short or tall grass). For both sexes, QAICc values clearly favored isolation-by-distance models, or models combining the effects of isolation by distance and habitat. Models with probability of dispersal expressed as linear-logistic functions of distance and as negative exponentials of distance fit the data equally well. Interpopulation movement probabilities were similar among sexes (perhaps slightly biased toward females), greater for juveniles than adults (especially for females), and greater before than during the breeding season (especially for females). These patterns resemble those previously described for within-population dispersal in this species, which we interpret as indicating that the same processes initiate both within- and between-population dispersal.

  4. Diatexite Deformation and Magma Extraction on Kangaroo Island, South Australia

    NASA Astrophysics Data System (ADS)

    Hasalova, P.; Weinberg, R. F.; Ward, L.; Fanning, C. M.

    2012-12-01

    Migmatite terranes are structurally complex. We have investigated the relationships between deformation and magma extraction in migmatites formed during the Delamerian orogeny on Kangaroo Island. Several phases of deformation occurred in the presence of melt (D1-D4) and we describe how magma segregation, accumulation and extraction changes with deformation style. During an early upright folding event (D2), magma was channelled towards the hinge of antiforms. Funnel-shaped networks of leucosomes form a root that link towards a central axial planar channel, marking the main magma extraction paths. Extraction was associated with limb collapse, and antiformal hinge disruption. During a later deformation phase (D4), diatexites were sheared so that schollen were disaggregated into smaller blocks and schlieren, and deformed into asymmetric, sigmoidal shapes. Foliations in the magmatic matrix and schollen asymmetry indicate dextral shearing. During flow, magma accumulated in shear planes, indicating a dilational component during shearing (transtension) and on strain shadows of schollen. As deformation waned (post-D4), magma extraction from these diatexites gave rise to steeply dipping, funnel-shaped channels, similar to those developed during folding. The funnel-shape networks are interpreted as magma extraction networks and indicate magma flow direction. Structures developed during this phase are comparable with those developed during dewatering of soft sediments. The magmatic rocks from migmatites formed early, during folding, and formed late after deformation waned were dated. Both have two monazite (U-Pb, SHRIMP) age groups of ~490Ma and ~505-520Ma. The older sample has a well-defined peak at 505-510Ma and trails into the younger ages. The younger sample has the opposite, with few old spots and a well-defined young peak at ~490Ma. The age range indicates the duration of anatexis, and well-defined peaks are interpreted to mark the age of individual magma batch

  5. Kangaroo Mother Care and Neonatal Outcomes: A Meta-analysis

    PubMed Central

    Dastjerdi, Roya; Spiegelman, Donna; Fawzi, Wafaie W.; Missmer, Stacey A.; Lieberman, Ellice; Kajeepeta, Sandhya; Wall, Stephen; Chan, Grace J.

    2016-01-01

    CONTEXT: Kangaroo mother care (KMC) is an intervention aimed at improving outcomes among preterm and low birth weight newborns. OBJECTIVE: Conduct a systematic review and meta-analysis estimating the association between KMC and neonatal outcomes. DATA SOURCES: PubMed, Embase, Web of Science, Scopus, African Index Medicus (AIM), Latin American and Caribbean Health Sciences Information System (LILACS), Index Medicus for the Eastern Mediterranean Region (IMEMR), Index Medicus for the South-East Asian Region (IMSEAR), and Western Pacific Region Index Medicus (WPRIM). STUDY SELECTION: We included randomized trials and observational studies through April 2014 examining the relationship between KMC and neonatal outcomes among infants of any birth weight or gestational age. Studies with <10 participants, lack of a comparison group without KMC, and those not reporting a quantitative association were excluded. DATA EXTRACTION: Two reviewers extracted data on study design, risk of bias, KMC intervention, neonatal outcomes, relative risk (RR) or mean difference measures. RESULTS: 1035 studies were screened; 124 met inclusion criteria. Among LBW newborns, KMC compared to conventional care was associated with 36% lower mortality(RR 0.64; 95% [CI] 0.46, 0.89). KMC decreased risk of neonatal sepsis (RR 0.53, 95% CI 0.34, 0.83), hypothermia (RR 0.22; 95% CI 0.12, 0.41), hypoglycemia (RR 0.12; 95% CI 0.05, 0.32), and hospital readmission (RR 0.42; 95% CI 0.23, 0.76) and increased exclusive breastfeeding (RR 1.50; 95% CI 1.26, 1.78). Newborns receiving KMC had lower mean respiratory rate and pain measures, and higher oxygen saturation, temperature, and head circumference growth. LIMITATIONS: Lack of data on KMC limited the ability to assess dose-response. CONCLUSIONS: Interventions to scale up KMC implementation are warranted. PMID:26702029

  6. Microsatellite marker development and Mendelian analysis in the Matschie's tree kangaroo (Dendrolagus matschiei).

    PubMed

    McGreevy, Thomas J; Dabek, Lisa; Husband, Thomas P

    2010-01-01

    Matschie's tree kangaroo (Dendrolagus matschiei) is an endangered arboreal macropodid endemic to the Huon Peninsula, Papua New Guinea (PNG). We developed 5 microsatellite markers for D. matschiei, which are the first markers developed for Dendrolagus. We screened 17 additional markers that were developed for other marsupial taxa and identified 3 that were polymorphic in D. matschiei. We estimated allelic and genetic diversity with the set of 8 markers by analyzing 22 D. matschiei from Wasaunon on the Huon Peninsula, PNG. The number of alleles ranged from 2 to 9 and expected heterozygosity ranged from 0.440 to 0.794. We tested for null alleles and Mendelian inheritance by analyzing 19 pairs of D. matschiei parents and offspring from Association of Zoos and Aquariums institutions. Null alleles were not detected and Mendelian inheritance was followed for all 8 markers. We also evaluated the reliability of using the markers to amplify DNA extracted from D. matschiei fecal samples and the ability of the markers to amplify DNA samples from Goodfellow's tree kangaroo (Dendrolagus goodfellowi ssp.), Doria's tree kangaroo (Dendrolagus dorianus ssp.), and Grizzled tree kangaroo (Dendrolagus inustus ssp.). Microsatellite markers can be used to inform management decisions to conserve D. matschiei in captivity and the wild.

  7. To kill a kangaroo: understanding the decision to pursue high-risk/high-gain resources.

    PubMed

    Jones, James Holland; Bird, Rebecca Bliege; Bird, Douglas W

    2013-09-22

    In this paper, we attempt to understand hunter-gatherer foraging decisions about prey that vary in both the mean and variance of energy return using an expected utility framework. We show that for skewed distributions of energetic returns, the standard linear variance discounting (LVD) model for risk-sensitive foraging can produce quite misleading results. In addition to creating difficulties for the LVD model, the skewed distributions characteristic of hunting returns create challenges for estimating probability distribution functions required for expected utility. We present a solution using a two-component finite mixture model for foraging returns. We then use detailed foraging returns data based on focal follows of individual hunters in Western Australia hunting for high-risk/high-gain (hill kangaroo) and relatively low-risk/low-gain (sand monitor) prey. Using probability densities for the two resources estimated from the mixture models, combined with theoretically sensible utility curves characterized by diminishing marginal utility for the highest returns, we find that the expected utility of the sand monitors greatly exceeds that of kangaroos despite the fact that the mean energy return for kangaroos is nearly twice as large as that for sand monitors. We conclude that the decision to hunt hill kangaroos does not arise simply as part of an energetic utility-maximization strategy and that additional social, political or symbolic benefits must accrue to hunters of this highly variable prey.

  8. Molecular detection of hybridization between sympatric kangaroo species in south-eastern Australia.

    PubMed

    Neaves, L E; Zenger, K R; Cooper, D W; Eldridge, M D B

    2010-05-01

    Introgressive hybridization has traditionally been regarded as rare in many vertebrate groups, including mammals. Despite a propensity to hybridize in captivity, introgression has rarely been reported between wild sympatric macropodid marsupials. Here we investigate sympatric populations of western (Macropus fuliginosus) and eastern (Macropus giganteus) grey kangaroos through 12 autosomal microsatellite loci and 626 bp of the hypervariable mitochondrial DNA (mtDNA) control region. M. fuliginosus and M. giganteus within the region of sympatry corresponded, both genetically and morphologically, to their respective species elsewhere in their distributions. Of the 223 grey kangaroos examined, 7.6% displayed evidence of introgression, although no F1 hybrids were detected. In contrast to captive studies, there was no evidence for unidirectional hybridization in sympatric grey kangaroos. However, a higher portion of M. giganteus backcrosses existed within the sample compared with M. fuliginosus. Hybridization in grey kangaroos is reflective of occasional breakdowns in species boundaries, occurring throughout the region and potentially associated with variable conditions and dramatic reductions in densities. Such rare hybridization events allow populations to incorporate novel diversity while still retaining species integrity.

  9. Extended anaesthesia and nasotracheal intubation of a red kangaroo (Macropus rufus).

    PubMed

    Bauquier, S H; Golder, F J

    2010-11-01

    Anaesthesia requires maintenance of a patent airway. Nasotracheal intubation of a red kangaroo (Macropus rufus) was performed when the inability to open the animal’s mouth prevented orotracheal intubation. Nasotracheal intubation was easy to perform, secured the airway and permitted delivery of supplemental oxygen, isoflurane and intermittent positive pressure ventilation.

  10. Recent amplification of the kangaroo endogenous retrovirus, KERV, limited to the centromere.

    PubMed

    Ferreri, Gianni C; Brown, Judith D; Obergfell, Craig; Jue, Nathaniel; Finn, Caitlin E; O'Neill, Michael J; O'Neill, Rachel J

    2011-05-01

    Mammalian retrotransposons, transposable elements that are processed through an RNA intermediate, are categorized as short interspersed elements (SINEs), long interspersed elements (LINEs), and long terminal repeat (LTR) retroelements, which include endogenous retroviruses. The ability of transposable elements to autonomously amplify led to their initial characterization as selfish or junk DNA; however, it is now known that they may acquire specific cellular functions in a genome and are implicated in host defense mechanisms as well as in genome evolution. Interactions between classes of transposable elements may exert a markedly different and potentially more significant effect on a genome than interactions between members of a single class of transposable elements. We examined the genomic structure and evolution of the kangaroo endogenous retrovirus (KERV) in the marsupial genus Macropus. The complete proviral structure of the kangaroo endogenous retrovirus, phylogenetic relationship among relative retroviruses, and expression of this virus in both Macropus rufogriseus and M. eugenii are presented for the first time. In addition, we show the relative copy number and distribution of the kangaroo endogenous retrovirus in the Macropus genus. Our data indicate that amplification of the kangaroo endogenous retrovirus occurred in a lineage-specific fashion, is restricted to the centromeres, and is not correlated with LINE depletion. Finally, analysis of KERV long terminal repeat sequences using massively parallel sequencing indicates that the recent amplification in M. rufogriseus is likely due to duplications and concerted evolution rather than a high number of independent insertion events.

  11. Cryopreservation of kangaroo spermatozoa using alternative approaches that reduce cytotoxic exposure to glycerol.

    PubMed

    McClean, Rhett; Zee, Yeng Peng; Holt, William V; Johnston, Stephen D

    2008-12-01

    Alternative techniques for the cryopreservation of kangaroo spermatozoa that reduced or eliminated the need for glycerol were investigated including; (1) freezing spermatozoa with 20% glycerol in pre-packaged 0.25 mL Cassou straws to enable rapid dilution of the glycerol post-thaw, (2) investigating the efficacy of 20% (v/v) dimethyl sulphoxide (DMSO) and dimethylacetamide (DMA-10%, 15% and 20% v/v) as cryoprotectants and (3) vitrification of spermatozoa with or without cryoprotectant (20% v/v glycerol, 20% v/v DMSO and 20% v/v DMA). Immediate in-straw post-thaw dilution of 20% glycerol and cryopreservation of spermatozoa in 20% DMSO produced no significant improvement in post-thaw viability of kangaroo spermatozoa. Spermatozoa frozen in 20% DMA showed post-thaw motility and plasma membrane integrity of 12.7+/-1.9% and 22.7+/-5.4%, respectively, while kangaroo spermatozoa frozen by ultra-rapid freezing techniques showed no evidence of post-thaw viability. The use of 10-20% DMA represents a modest but significant improvement in the development of a sperm cryopreservation procedure for kangaroos.

  12. To kill a kangaroo: understanding the decision to pursue high-risk/high-gain resources

    PubMed Central

    Jones, James Holland; Bird, Rebecca Bliege; Bird, Douglas W.

    2013-01-01

    In this paper, we attempt to understand hunter–gatherer foraging decisions about prey that vary in both the mean and variance of energy return using an expected utility framework. We show that for skewed distributions of energetic returns, the standard linear variance discounting (LVD) model for risk-sensitive foraging can produce quite misleading results. In addition to creating difficulties for the LVD model, the skewed distributions characteristic of hunting returns create challenges for estimating probability distribution functions required for expected utility. We present a solution using a two-component finite mixture model for foraging returns. We then use detailed foraging returns data based on focal follows of individual hunters in Western Australia hunting for high-risk/high-gain (hill kangaroo) and relatively low-risk/low-gain (sand monitor) prey. Using probability densities for the two resources estimated from the mixture models, combined with theoretically sensible utility curves characterized by diminishing marginal utility for the highest returns, we find that the expected utility of the sand monitors greatly exceeds that of kangaroos despite the fact that the mean energy return for kangaroos is nearly twice as large as that for sand monitors. We conclude that the decision to hunt hill kangaroos does not arise simply as part of an energetic utility-maximization strategy and that additional social, political or symbolic benefits must accrue to hunters of this highly variable prey. PMID:23884091

  13. Species-specific footdrumming in kangaroo rats: Dipodomys ingens, D. deserti, D. spectabilis

    PubMed

    Randall

    1997-11-01

    Footdrumming was compared in three allopatric species of kangaroo rat, Dipodomysfrom three habitats. Analysis of footdrumming recordings revealed species-specific patterns of drumming ranging from single thumps to individual footdrumming signatures. The desert kangaroo rat, D. desertidrums single thumps spaced 0.25-0.30 s apart that are sometimes introduced with a short footroll. The giant kangaroo rat, D. ingensdrums long footrolls that can average over 100 drums at 18 drums/s. The banner-tailed kangaroo rat, D. spectabilisdrums three to 38 footdrums in a footroll combined into sequences of two to 12 footrolls at a rate of 17 drums/s. In playback tests, all three species stood in alert postures and entered the burrow in response to footdrumming of their own and the other species. The rats also responded in species-specific ways. Dipodomys spectabilisdrummed to its own species' footdrumming, but not to playbacks of the single drums of D. desertiInstead of footdrumming to playbacks of its own species, D. deserti approached the speaker more frequently than did either of the other two species. Dipodomys ingens footdrummed equally to all footdrumming playbacks. The species' differences reflect differences in social tolerance and spacing. Dipodomys deserti rarely engages in footdrumming exchanges and chases visitors from the burrow. Dipodomys spectabilis engages in frequent footdrumming exchanges and some chases, and D. ingens seems to tolerate close neighbours and footdrums periodically.Copyright 1997 The Association for the Study of Animal Behaviour1997The Association for the Study of Animal Behaviour

  14. Experimental manipulation reveals few subclinical impacts of a parasite community in juvenile kangaroos

    PubMed Central

    Cripps, Jemma; Beveridge, Ian; Ploeg, Richard; Coulson, Graeme

    2014-01-01

    Large mammalian herbivores are commonly infected with gastrointestinal helminths. In many host species, these helminths cause clinical disease and may trigger conspicuous mortality events. However, they may also have subclinical impacts, reducing fitness as well as causing complex changes to host growth patterns and body condition. Theoretically, juveniles should experience significantly greater costs from parasites, being immunologically naive and undergoing a significant growth phase. The aims of our study were to quantify the subclinical effects of helminths in juvenile eastern grey kangaroos (Macropus giganteus), which commonly harbour large burdens of gastrointestinal nematodes and are susceptible to associated mass mortality during cold, wet conditions. We conducted a field experiment on a population of free-ranging kangaroos, removing nematodes from one group of juveniles using an anthelmintic treatment. We then compared growth parameters (body condition and growth rates) and haematological parameters of this group with an age-matched, parasitised (untreated) control group. Treated juvenile kangaroos had significantly higher levels of plasma protein (albumin) but, contrary to our predictions, showed negligible changes in all the other parameters measured. Our results suggest that juvenile kangaroos are largely unaffected by their gastrointestinal helminth burdens, and may be able to compensate for the costs of parasites. PMID:25161906

  15. Hopping Down the Main Street: Eastern Grey Kangaroos at Home in an Urban Matrix

    PubMed Central

    Coulson, Graeme; Cripps, Jemma K.; Wilson, Michelle E.

    2014-01-01

    Simple Summary Eastern Grey Kangaroos (Macropus giganteus) occur throughout the seaside town of Anglesea in southern Victoria, Australia. We have tagged about half of these kangaroos in a longitudinal study of population dynamics and behavior. A golf course forms the nucleus of this population. Females live on and around the golf course, but males roam across the town in autumn and winter, living in bush reserves, empty blocks and back yards. Most females breed every year, but over half of their young disappear. Vehicles are the major cause of adult deaths, killing a much higher proportion of males than females. Abstract Most urban mammals are small. However, one of the largest marsupials, the Eastern Grey Kangaroo Macropus giganteus, occurs in some urban areas. In 2007, we embarked on a longitudinal study of this species in the seaside town of Anglesea in southern Victoria, Australia. We have captured and tagged 360 individuals to date, fitting each adult with a collar displaying its name. We have monitored survival, reproduction and movements by resighting, recapture and radio-tracking, augmented by citizen science reports of collared individuals. Kangaroos occurred throughout the town, but the golf course formed the nucleus of this urban population. The course supported a high density of kangaroos (2–5/ha), and approximately half of them were tagged. Total counts of kangaroos on the golf course were highest in summer, at the peak of the mating season, and lowest in winter, when many males but not females left the course. Almost all tagged adult females were sedentary, using only part of the golf course and adjacent native vegetation and residential blocks. In contrast, during the non-mating season (autumn and winter), many tagged adult males ranged widely across the town in a mix of native vegetation remnants, recreation reserves, vacant blocks, commercial properties and residential gardens. Annual fecundity of tagged females was generally high (≥70%), but

  16. Scaling of left ventricle cardiomyocyte ultrastructure across development in the kangaroo Macropus fuliginosus.

    PubMed

    Snelling, Edward P; Taggart, David A; Maloney, Shane K; Farrell, Anthony P; Leigh, Christopher M; Waterhouse, Lyn; Williams, Ruth; Seymour, Roger S

    2015-06-01

    The heart and left ventricle of the marsupial western grey kangaroo Macropus fuliginosus exhibit biphasic allometric growth, whereby a negative shift in the trajectory of cardiac growth occurs at pouch exit. In this study, we used transmission electron microscopy to examine the scaling of left ventricle cardiomyocyte ultrastructure across development in the western grey kangaroo over a 190-fold body mass range (0.355-67.5 kg). The volume-density (%) of myofibrils, mitochondria, sarcoplasmic reticuli and T-tubules increase significantly during in-pouch growth, such that the absolute volume (ml) of these organelles scales with body mass (Mb; kg) with steep hyperallometry: 1.41Mb (1.38), 0.64Mb (1.29), 0.066Mb (1.45) and 0.035Mb (1.87), respectively. Maturation of the left ventricle ultrastructure coincides with pouch vacation, as organelle volume-densities scale independent of body mass across post-pouch development, such that absolute organelle volumes scale in parallel and with relatively shallow hypoallometry: 4.65Mb (0.79), 1.75Mb (0.77), 0.21Mb (0.79) and 0.35Mb (0.79), respectively. The steep hyperallometry of organelle volumes and volume-densities across in-pouch growth is consistent with the improved contractile performance of isolated cardiac muscle during fetal development in placental mammals, and is probably critical in augmenting cardiac output to levels necessary for endothermy and independent locomotion in the young kangaroo as it prepares for pouch exit. The shallow hypoallometry of organelle volumes during post-pouch growth suggests a decrease in relative cardiac requirements as body mass increases in free-roaming kangaroos, which is possibly because the energy required for hopping is independent of speed, and the capacity for energy storage during hopping could increase as the kangaroo grows.

  17. Functional morphology of the forelimb of living and extinct tree-kangaroos (Marsupialia: Macropodidae).

    PubMed

    Warburton, Natalie M; Harvey, Kathryn J; Prideaux, Gavin J; O'Shea, James E

    2011-10-01

    Tree-kangaroos are a unique group of arboreal marsupials that evolved from terrestrial ancestors. The recent discovery of well-preserved specimens of extinct tree-kangaroo species (genus Bohra) within Pleistocene cave deposits of south-central Australia provides a unique opportunity to examine adaptive evolution of tree-kangaroos. Here, we provide the first detailed description of the functional anatomy of the forelimb, a central component of the locomotor complex, in the extant Dendrolagus lumholtzi, and compare its structure and function with representatives of other extant marsupial families. Several features were interpreted as adaptations for coping with a discontinuous, uneven and three-dimensional arboreal substrate through enhanced muscular strength and dexterity for propulsion, grasping, and gripping with the forelimbs. The forelimb musculoskeletal anatomy of Dendrolagus differed from terrestrial kangaroos in the following principal ways: a stronger emphasis on the development of muscles groups responsible for adduction, grasping, and gripping; the enlargement of muscles that retract the humerus; and modified shape of the scapula and bony articulations of the forelimb bones to allow improved mobility. Many of these attributes are convergent with other arboreal marsupials. Tree-kangaroos, however, still retain the characteristic bauplan of their terrestrial ancestors, particularly with regard to skeletal morphology, and the muscular anatomy of the forelimb highlights a basic conservatism within the group. In many instances, the skeletal remains of Bohra have similar features to Dendrolagus that suggest adaptations to an arboreal habit. Despite the irony of their retrieval from deposits of the Nullarbor "Treeless" Plain, forelimb morphology clearly shows that the species of Bohra were well adapted to an arboreal habitat.

  18. Architecture of kangaroo rat inner medulla: segmentation of descending thin limb of Henle's loop.

    PubMed

    Urity, Vinoo B; Issaian, Tadeh; Braun, Eldon J; Dantzler, William H; Pannabecker, Thomas L

    2012-03-15

    We hypothesize that the inner medulla of the kangaroo rat Dipodomys merriami, a desert rodent that concentrates its urine to more than 6,000 mosmol/kgH(2)O water, provides unique examples of architectural features necessary for production of highly concentrated urine. To investigate this architecture, inner medullary nephron segments in the initial 3,000 μm below the outer medulla were assessed with digital reconstructions from physical tissue sections. Descending thin limbs of Henle (DTLs), ascending thin limbs of Henle (ATLs), and collecting ducts (CDs) were identified by immunofluorescence using antibodies that label segment-specific proteins associated with transepithelial water flux (aquaporin 1 and 2, AQP1 and AQP2) and chloride flux (the chloride channel ClC-K1); all tubules and vessels were labeled with wheat germ agglutinin. In the outer 3,000 μm of the inner medulla, AQP1-positive DTLs lie at the periphery of groups of CDs. ATLs lie inside and outside the groups of CDs. Immunohistochemistry and reconstructions of loops that form their bends in the outer 3,000 μm of the inner medulla show that, relative to loop length, the AQP1-positive segment of the kangaroo rat is significantly longer than that of the Munich-Wistar rat. The length of ClC-K1 expression in the prebend region at the terminal end of the descending side of the loop in kangaroo rat is about 50% shorter than that of the Munich-Wistar rat. Tubular fluid of the kangaroo rat DTL may approach osmotic equilibrium with interstitial fluid by water reabsorption along a relatively longer tubule length, compared with Munich-Wistar rat. A relatively shorter-length prebend segment may promote a steeper reabsorptive driving force at the loop bend. These structural features predict functionality that is potentially significant in the production of a high urine osmolality in the kangaroo rat.

  19. A continent-wide analysis of the shade requirements of red and western grey kangaroos

    PubMed Central

    Roberts, J. A.; Coulson, G.; Munn, A. J.; Kearney, M. R.

    2016-01-01

    ABSTRACT Foraging time may be constrained by a suite of phenomena including weather, which can restrict a species' activity and energy intake. This is recognized as pivotal for many species whose distributions are known to correlate with climate, including kangaroos, although such impacts are rarely quantified. We explore how differences in shade seeking, a thermoregulatory behavior, of 2 closely-related kangaroo species, Macropus rufus (red kangaroos) and M. fuliginosus (western grey kangaroos), might reflect differences in their distributions across Australia. We observed foraging and shade-seeking behavior in the field and, together with local weather observations, calculated threshold radiant temperatures (based on solar and infrared radiant heat loads) over which the kangaroos retreated to shade. We apply these calculated tolerance thresholds to hourly microclimatic estimates derived from daily-gridded weather data to predict activity constraints across the Australian continent over a 10-year period. M. fuliginosus spent more time than M. rufus in the shade (7.6 ± 0.7 h versus 6.4 ± 0.9 h) and more time foraging (11.8 ± 0.5 h vs. 10.0 ± 0.6 h), although total time resting was equivalent (∼8.2 h). M. rufus tolerated 19°C higher radiant temperatures than M. fuliginosus (89°C versus 70°C radiant temperature). Across Australia, we predicted M. fuliginosus to be more restricted to shade than M. rufus, with higher absolute shade requirements farther north. These results corroborate previous findings that M. rufus is more adept at dealing with heat than M. fuliginosus and indicate that M. rufus is less dependent on shade on a continental scale. PMID:27857963

  20. A continent-wide analysis of the shade requirements of red and western grey kangaroos.

    PubMed

    Roberts, J A; Coulson, G; Munn, A J; Kearney, M R

    2016-01-01

    Foraging time may be constrained by a suite of phenomena including weather, which can restrict a species' activity and energy intake. This is recognized as pivotal for many species whose distributions are known to correlate with climate, including kangaroos, although such impacts are rarely quantified. We explore how differences in shade seeking, a thermoregulatory behavior, of 2 closely-related kangaroo species, Macropus rufus (red kangaroos) and M. fuliginosus (western grey kangaroos), might reflect differences in their distributions across Australia. We observed foraging and shade-seeking behavior in the field and, together with local weather observations, calculated threshold radiant temperatures (based on solar and infrared radiant heat loads) over which the kangaroos retreated to shade. We apply these calculated tolerance thresholds to hourly microclimatic estimates derived from daily-gridded weather data to predict activity constraints across the Australian continent over a 10-year period. M. fuliginosus spent more time than M. rufus in the shade (7.6 ± 0.7 h versus 6.4 ± 0.9 h) and more time foraging (11.8 ± 0.5 h vs. 10.0 ± 0.6 h), although total time resting was equivalent (∼8.2 h). M. rufus tolerated 19°C higher radiant temperatures than M. fuliginosus (89°C versus 70°C radiant temperature). Across Australia, we predicted M. fuliginosus to be more restricted to shade than M. rufus, with higher absolute shade requirements farther north. These results corroborate previous findings that M. rufus is more adept at dealing with heat than M. fuliginosus and indicate that M. rufus is less dependent on shade on a continental scale.

  1. Preterm newborns at Kangaroo Mother Care: a cohort follow-up from birth to six months

    PubMed Central

    Menezes, Maria Alexsandra da S.; Garcia, Daniela Cavalcante; de Melo, Enaldo Vieira; Cipolotti, Rosana

    2014-01-01

    OBJECTIVE: To evaluate clinical outcomes, growth and exclusive breastfeeding rates in premature infants assisted by Kangaroo Mother Care at birth, at discharge and at six months of life. METHODS: Prospective study of a premature infants cohort assisted by Kangaroo Mother Care in a tertiary public maternity in Northeast Brazil with birth weight ≤1750g and with clinical conditions for Kangaroo care. RESULTS: The sample was composed by 137 premature infants, being 62.8% female, with average birth weight of 1365±283g, average gestational age of 32±3 weeks and 26.2% were adequate for gestational age. They have been admitted in the Kangaroo Ward with a median of 13 days of life, weighing 1430±167g and, at this time, 57.7% were classified as small for corrected gestational age. They were discharged with 36.8±21.8 days of chronological age, weighing 1780±165g and 67.9% were small for corrected gestational age. At six months of life (n=76), they had an average weight of 5954±971g, and 68.4% presented corrected weight for gestational age between percentiles 15 and 85 of the World Health Organization (WHO) weight curve. Exclusive breastfeeding rate at discharge was 56.2% and, at six months of life, 14.4%. CONCLUSIONS: In the studied sample, almost two thirds of the children assisted by Kangaroo Mother Care were, at six months of life, between percentiles 15 and 85 of the WHO weight curves. The frequency of exclusive breastfeeding at six months was low. PMID:25119747

  2. Divergence in sink contributions to population persistence.

    PubMed

    Heinrichs, Julie A; Lawler, Joshua J; Schumaker, Nathan H; Wilsey, Chad B; Bender, Darren J

    2015-12-01

    Population sinks present unique conservation challenges. The loss of individuals in sinks can compromise persistence; but conversely, sinks can improve viability by improving connectivity and facilitating the recolonization of vacant sources. To assess the contribution of sinks to regional population persistence of declining populations, we simulated source-sink dynamics for 3 very different endangered species: Black-capped Vireos (Vireo atricapilla) at Fort Hood, Texas, Ord's kangaroo rats (Dipodomys ordii) in Alberta, and Northern Spotted Owls (Strix occidentalis caurina) in the northwestern United States. We used empirical data from these case studies to parameterize spatially explicit individual-based models. We then used the models to quantify population abundance and persistence with and without long-term sinks. The contributions of sink habitats varied widely. Sinks were detrimental, particularly when they functioned as strong sinks with few emigrants in declining populations (e.g., Alberta's Ord's kangaroo rat) and benign in robust populations (e.g., Black-capped Vireos) when Brown-headed Cowbird (Molothrus ater) parasitism was controlled. Sinks, including ecological traps, were also crucial in delaying declines when there were few sources (e.g., in Black-capped Vireo populations with no Cowbird control). Sink contributions were also nuanced. For example, sinks that supported large, variable populations were subject to greater extinction risk (e.g., Northern Spotted Owls). In each of our case studies, new context-dependent sinks emerged, underscoring the dynamic nature of sources and sinks and the need for frequent re-assessment. Our results imply that management actions based on assumptions that sink habitats are generally harmful or helpful risk undermining conservation efforts for declining populations.

  3. Diatexite Deformation and Magma Extraction on Kangaroo Island, South Australia

    NASA Astrophysics Data System (ADS)

    Hasalova, Pavlina; Weinberg, Roberto; Ward, Lindsay; Fanning, Mark

    2013-04-01

    Migmatite terranes are structurally complex because of strong rheological contrast between layers with different melt contents and because of magma migration leading to volume changes. Migmatite deformation is intimately linked with magma extraction and the origin of granitoids. We investigate here the relationships between an evolving deformation and magma extraction in migmatites formed during the ca. 500Ma Delamerian orogeny, exposed on Kangaroo Island, South Australia. Here, several phases of deformation occurred in the presence of melt. During an early upright, non-cylindrical folding event, magma was channeled towards the hinge zones of antiforms. Funnel-shaped networks of leucosomes form a root zone that link up towards a central axial planar channel, forming the main magma extraction paths during folding. Extraction was associated with fold limb collapse, and antiformal hinge disruption by magma accumulation and transfer. During a later deformation phase, melt-rich diatexites were deformed, and schollen were disaggregated into smaller blocks and schlieren, and deformed into asymmetric, sigmoidal shapes indicative of dextral shearing flow. During flow, magma accumulated preferentially along shear planes, indicating a dilatational component during shearing (transtension) and in strain shadows of schollen. As deformation waned, magma extraction from these diatexites gave rise to N-trending, steeply dipping, funnel-shaped channels not associated to any deformational feature. The funnel-shape of these structures indicates the direction of magma flow. Structures developed during this phase are comparable with those formed during dewatering of soft sediments. Despite a high degree of complexity, magma migration and extraction features record distinct responses to the evolving deformation which can be used to understand deformation, and nature and direction of melt extraction. The oldest and youngest magmatic rocks from migmatites were dated (U-Pb monazite, SHRIMP

  4. Trial of Repeated Analgesia with Kangaroo Mother Care (TRAKC Trial)

    PubMed Central

    2013-01-01

    Background Skin-to-skin contact (SSC) between mother and infant, commonly referred to as Kangaroo Mother Care (KMC), is recommended as an intervention for procedural pain. Evidence demonstrates its consistent efficacy in reducing pain for a single painful procedure. The purpose of this study is to examine the sustained efficacy of KMC, provided during all routine painful procedures for the duration of Neonatal Intensive Care Unit (NICU) hospitalization, in diminishing behavioral pain response in preterm neonates. The efficacy of KMC alone will be compared to standard care of 24% oral sucrose, as well as the combination of KMC and 24% oral sucrose. Methods/design Infants admitted to the NICU who are less than 36 6/7 weeks gestational age (according to early ultrasound), that are stable enough to be held in KMC, will be considered eligible (N = 258). Using a single-blinded randomized parallel group design, participants will be assigned to one of three possible interventions: 1) KMC, 2) combined KMC and sucrose, and 3) sucrose alone, when they undergo any routine painful procedure (heel lance, venipuncture, intravenous, oro/nasogastric insertion). The primary outcome is infant’s pain intensity, which will be assessed using the Premature Infant Pain Profile (PIPP). The secondary outcome will be maturity of neurobehavioral functioning, as measured by the Neurobehavioral Assessment of the Preterm Infant (NAPI). Gestational age, cumulative exposure to KMC provided during non-pain contexts, and maternal cortisol levels will be considered in the analysis. Clinical feasibility will be accounted for from nurse and maternal questionnaires. Discussion This will be the first study to examine the repeated use of KMC for managing procedural pain in preterm neonates. It is also the first to compare KMC to sucrose, or the interventions in combination, across time. Based on the theoretical framework of the brain opioid theory of attachment, it is expected that KMC will be a

  5. Implementing facility-based kangaroo mother care services: lessons from a multi-country study in Africa

    PubMed Central

    2014-01-01

    Background Some countries have undertaken programs that included scaling up kangaroo mother care. The aim of this study was to systematically evaluate the implementation status of facility-based kangaroo mother care services in four African countries: Malawi, Mali, Rwanda and Uganda. Methods A cross-sectional, mixed-method research design was used. Stakeholders provided background information at national meetings and in individual interviews. Facilities were assessed by means of a standardized tool previously applied in other settings, employing semi-structured key-informant interviews and observations in 39 health care facilities in the four countries. Each facility received a score out of a total of 30 according to six stages of implementation progress. Results Across the four countries 95 per cent of health facilities assessed demonstrated some evidence of kangaroo mother care practice. Institutions that fared better had a longer history of kangaroo mother care implementation or had been developed as centres of excellence or had strong leaders championing the implementation process. Variation existed in the quality of implementation between facilities and across countries. Important factors identified in implementation are: training and orientation; supportive supervision; integrating kangaroo mother care into quality improvement; continuity of care; high-level buy in and support for kangaroo mother care implementation; and client-oriented care. Conclusion The integration of kangaroo mother care into routine newborn care services should be part of all maternal and newborn care initiatives and packages. Engaging ministries of health and other implementing partners from the outset may promote buy in and assist with the mobilization of resources for scaling up kangaroo mother care services. Mechanisms for monitoring these services should be integrated into existing health management information systems. PMID:25001366

  6. Health assessment of free-ranging and captive Matschie's tree kangaroos (Dendrolagus matschiei) in Papua New Guinea.

    PubMed

    Travis, Erika K; Watson, Patricia; Dabek, Lisa

    2012-03-01

    Medical evaluations were performed on free-ranging and captive Matschie's tree kangaroos (Dendrolagus matschiei) in Papua New Guinea. The health assessment included physical examination, morphometrics, cloacal swab; and blood, hair, and feces collection. Radio-collars were placed on free-ranging tree kangaroos to determine home range and forest habitat use. The free-ranging tree kangaroos were lightly anesthetized with tiletamine/zolazepam for the data collection. A total of nine free-ranging and seven captive tree kangaroos were evaluated; medical samples were collected from six and five animals, respectively. Results of physical examination, anesthetic monitoring, serum vitamin, mineral, trace nutrient, and electrolytes, whole blood heavy metal analysis, mycobacterial screening, and fecal examinations are presented. Free-ranging tree kangaroos had significantly lower values for beta carotene, copper, selenium, molybdenum, lead, and arsenic and significantly higher values for vitamin E than captive individuals. Cloacal swabs were all negative for Mycobacterium avium via polymerase chain reaction. Some free-ranging and captive individuals had positive coprologic exams revealing Eimeria spp. oocysts and strongyle spp. type ova. These are the first medical and anesthetic data published on Matschie's tree kangaroos from Papua New Guinea.

  7. Water use and the thermoregulatory behaviour of kangaroos in arid regions: insights into the colonisation of arid rangelands in Australia by the Eastern Grey Kangaroo (Macropus giganteus).

    PubMed

    Dawson, Terence J; McTavish, Kirsten J; Munn, Adam J; Holloway, Joanne

    2006-01-01

    The Eastern Grey Kangaroo (Macropus giganteus) occurs mostly in the wetter regions of eastern Australia. However, in the past 30-40 years it has moved into more arid regions (rainfall < 250 mm), thus increasing its overlap zone with the xeric adapted Red Kangaroo (Macropus rufus). An increased access to water (supplied for domestic stock) may explain this range extension, but changes in the availability of preferred feed could also be involved. The water use, drinking patterns and thermoregulatory behaviour of these two species of kangaroo have been examined in a semi-free range study, during summer at an arid rangeland site. Foraging was largely nocturnal in both species and during the day they behaved to reduce heat loads. This was especially so for M. giganteus, which showed greater shade seeking. However, it still used more water (72 +/- 2.6 mL kg(-1) day(-1), mean +/- SE) than M. rufus (56 +/- 7.6 mL kg(-1) day(-1)) and drank twice as frequently. Although M. giganteus produced a less concentrated urine (1422 +/- 36 mosmol kg(-1)) than M. rufus (1843 +/- 28 mosmol kg(-1)), kidney physiology did not explain all of the differences in water metabolism between the species. Water from the feed and faecal water retention also appear to be involved. Broadly, a better access to reliable water and the utilisation of mesic microhabitats has enabled M. giganteus to make inroads into the changing rangelands of eastern Australia. However, changes in the vegetation, due to stock grazing, have also favoured M. giganteus, which is a grass eating specialist.

  8. The complete mitochondrial genome of the eastern grey kangaroo (Macropus giganteus).

    PubMed

    Dodt, William G; McComish, Bennet J; Nilsson, Maria A; Gibb, Gillian C; Penny, David; Phillips, Matthew J

    2016-01-01

    We present the complete mitochondrial genome (accession number: LK995454) of an iconic Australian species, the eastern grey kangaroo (Macropus giganteus). The mitogenomic organization is consistent with other marsupials, encoding 13 protein-coding genes, 22 tRNA genes, 2 ribosomal RNA genes, an origin of light strand replication and a control region or D-loop. No repetitive sequences were detected in the control region. The M. giganteus mitogenome exemplifies a combination of tRNA gene order and structural peculiarities that appear to be unique to marsupials. We present a maximum likelihood phylogeny based on complete mitochondrial protein and RNA coding sequences that confirms the phylogenetic position of the grey kangaroo among macropodids.

  9. Wheel running of kangaroo rats, Dipodomys merriami, as related to food deprivation and body composition.

    PubMed

    Dill, D B; Soholt, L F; Morris, J D

    1978-01-01

    Kangaroo rats deprived of food ran themselves to death in 48 h in wheel cages. Despite the loss of 14.5% of body weight the ratio of water to protein was the same after the run as it was in control rats. Metabolic measurements at rest and in the running wheel and weight loss in the 48-h run were used to estimate fuels used and water expended. Two-thirds of the initial amount of fat and 9% of the protein were metabolized. The terminal mean percentage of body fat was about twice that observed in rats trapped in the spring of 1967, when seed production was low: death in the 48-h run could not have been due to depletion of body fat alone. The powerful activity drive seen in hungary kangaroo rats presumably is intensified in dry years when food is scarce and may deplete their reserves enough to result in death from starvation.

  10. Somatic Expression and Autosomal Inheritance of Phosphoglycerate Kinase B in Kangaroos

    PubMed Central

    Vandeberg, J. L.; Cooper, D. W.; Sharman, G. B.; Poole, W. E.

    1980-01-01

    The PGK-B isozyme, currently known as PGK-2 in the mouse nomenclature, is the predominant PGK isozyme in mammalian sperm. In many species it is detectable only in sperm, in spermatogenic testes and in epididymides containing sperm. In this paper, we provide evidence that some kangaroo species express low PGK-B activity in somatic tissues, in addition to high activity in testes. Three kangaroo species, M. rufogriseus, M. robustus and M. giganteus, exhibit polymorphism of PGK-B. Breeding data support the hypothesis of autosomal co-dominant inheritance, as is the case in mice. Population data for the three polymorphisms are discussed. PGK-B is not detectable in somatic tissues or spermatogenic testis extracts of monotreme mammals, birds or lizards; it is probably restricted to therian mammals. PMID:7203002

  11. The complete mitochondrial genome of the Dipodomys ordii (Ord's kangaroo rat).

    PubMed

    Chen, Dayang; Zhang, Kai; Liu, Sheng; Chen, Fang

    2016-11-01

    Ord's kangaroo rat is a kangaroo rat native to western North America. In this study, we first reported the complete mitochondrial genome of Dipodomys ordii that the first has the complete mitochondrial genome in the genus of Heteromyidae. The mitogenome is a circular molecule of 16 257 bp in length, containing 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs and a putative displacement loop region. All protein-coding genes started with a traditional ATN codon and terminated with the mitochondria stop codon (TAA/TAG/AGA) or a single T base. The gene order and composition of mitogenome was similar to that of most other Sciurognathi species and its GC content was 36.73%. Thirteen protein-coding genes of D. ordii together with eight other closely species were used to construct the species phylogenetic tree for verification of the accuracy of new determined mitogenome sequences.

  12. The kangaroo cation-independent mannose 6-phosphate receptor binds insulin-like growth factor II with low affinity.

    PubMed

    Yandell, C A; Dunbar, A J; Wheldrake, J F; Upton, Z

    1999-09-17

    The mammalian cation-independent mannose 6-phosphate receptor (CI-MPR) binds mannose 6-phosphate-bearing glycoproteins and insulin-like growth factor (IGF)-II. However, the CI-MPR from the opossum has been reported to bind bovine IGF-II with low affinity (Dahms, N. M., Brzycki-Wessell, M. A., Ramanujam, K. S., and Seetharam, B. (1993) Endocrinology 133, 440-446). This may reflect the use of a heterologous ligand, or it may represent the intrinsic binding affinity of this receptor. To examine the binding of IGF-II to a marsupial CI-MPR in a homologous system, we have previously purified kangaroo IGF-II (Yandell, C. A., Francis, G. L., Wheldrake, J. F., and Upton, Z. (1998) J. Endocrinol. 156, 195-204), and we now report the purification and characterization of the CI-MPR from kangaroo liver. The interaction of the kangaroo CI-MPR with IGF-II has been examined by ligand blotting, radioreceptor assay, and real-time biomolecular interaction analysis. Using both a heterologous and homologous approach, we have demonstrated that the kangaroo CI-MPR has a lower binding affinity for IGF-II than its eutherian (placental mammal) counterparts. Furthermore, real-time biomolecular interaction analysis revealed that the kangaroo CI-MPR has a higher affinity for kangaroo IGF-II than for human IGF-II. The cDNA sequence of the kangaroo CI-MPR indicates that there is considerable divergence in the area corresponding to the IGF-II binding site of the eutherian receptor. Thus, the acquisition of a high-affinity binding site for regulating IGF-II appears to be a recent event specific to the eutherian lineage.

  13. Extinction implications of a chenopod browse diet for a giant Pleistocene kangaroo.

    PubMed

    Prideaux, Gavin J; Ayliffe, Linda K; DeSantis, Larisa R G; Schubert, Blaine W; Murray, Peter F; Gagan, Michael K; Cerling, Thure E

    2009-07-14

    Kangaroos are the world's most diverse group of herbivorous marsupials. Following late-Miocene intensification of aridity and seasonality, they radiated across Australia, becoming the continent's ecological equivalents of the artiodactyl ungulates elsewhere. Their diversity peaked during the Pleistocene, but by approximately 45,000 years ago, 90% of larger kangaroos were extinct, along with a range of other giant species. Resolving whether climate change or human arrival was the principal extinction cause remains highly contentious. Here we combine craniodental morphology, stable-isotopic, and dental microwear data to reveal that the largest-ever kangaroo, Procoptodon goliah, was a chenopod browse specialist, which may have had a preference for Atriplex (saltbushes), one of a few dicots using the C(4) photosynthetic pathway. Furthermore, oxygen isotope signatures of P. goliah tooth enamel show that it drank more in low-rainfall areas than its grazing contemporaries, similar to modern saltbush feeders. Saltbushes and chenopod shrublands in general are poorly flammable, so landscape burning by humans is unlikely to have caused a reduction in fodder driving the species to extinction. Aridity is discounted as a primary cause because P. goliah evolved in response to increased aridity and disappeared during an interval wetter than many it survived earlier. Hunting by humans, who were also bound to water, may have been a more decisive factor in the extinction of this giant marsupial.

  14. Anthelmintic Treatment Does Not Change Foraging Strategies of Female Eastern Grey Kangaroos, Macropus giganteus

    PubMed Central

    Cripps, Jemma K.; Martin, Jennifer K.; Coulson, Graeme

    2016-01-01

    Large mammalian herbivores are commonly infected with gastrointestinal helminths. Heavily parasitised hosts are likely to have increased nutritional requirements and would be predicted to increase their food intake to compensate for costs of being parasitised, but experimental tests of the impacts of these parasites on the foraging efficiency of hosts are lacking, particularly in free-ranging wildlife. We conducted a field experiment on a population of free-ranging eastern grey kangaroos (Macropus giganteus) to test this prediction, removing nematodes from one group of adult females using an anthelmintic treatment. We then carried out observations before and following treatment to assess the influence of parasites on foraging behaviour. Contrary to our predictions, the manipulation of parasite burdens did not result in changes in any of the key foraging variables we measured. Our results suggest that despite carrying large burdens of gastrointestinal parasites, the foraging strategy of female kangaroos is likely be driven by factors unrelated to parasitism, and that kangaroos in high nutritional environments may be able acquire sufficient nutrients to offset the costs of parasitism. We conclude that the drivers of forage intake likely differ between domesticated and free-ranging herbivores, and that free-ranging hosts are likely more resilient to parasitism. PMID:26784582

  15. Partitioning the effects of an ecosystem engineer: kangaroo rats control community structure via multiple pathways.

    PubMed

    Prugh, Laura R; Brashares, Justin S

    2012-05-01

    1. Ecosystem engineers impact communities by altering habitat conditions, but they can also have strong effects through consumptive, competitive and other non-engineering pathways. 2. Engineering effects can lead to fundamentally different community dynamics than non-engineering effects, but the relative strengths of these interactions are seldom quantified. 3. We combined structural equation modelling and exclosure experiments to partition the effects of a keystone engineer, the giant kangaroo rat (Dipodomys ingens), on plants, invertebrates and vertebrates in a semi-arid California grassland. 4. We separated the effects of burrow creation from kangaroo rat density and found that kangaroo rats increased the diversity and abundance of other species via both engineering and non-engineering pathways. 5. Engineering was the primary factor structuring plant and small mammal communities, whereas non-engineering effects structured invertebrate communities and increased lizard abundance. 6. These results highlight the importance of the non-engineering effects of ecosystem engineers and shed new light on the multiple pathways by which strong-interactors shape communities.

  16. Use of “Kangaroo Care” to Alleviate the Intensity of Vaccination Pain in Newborns

    PubMed Central

    Saeidi, Reza; Asnaashari, Zahra; Amirnejad, Mohtaram; Esmaeili, Habibollah; Robatsangi, Mahboobe Gholami

    2011-01-01

    Objective It has been demonstrated that newborns feel pain completely. Thus, they should be treated with this in mind. Recent research showed that non-pharmacological interventions such as “Kangaroo Care” may be useful for decreasing pain in newborns. We tried to determine the effect of kangaroo care on the pain intensity of vaccination in healthy newborns. Methods This study was a randomized case-control clinical trial. Subjects were 60 healthy full-term newborns delivered in a general Hospital, in Iran, from March to July 2006. They were randomly assigned to case and control groups. The case group received 30 minutes skin to skin contact, whereas infants in the control group were put, wrapped in a blanket, aside the mothers. Behavioral changes of newborns were evaluated and observed 2 minutes before, during, and 3 minutes after the intervention. All procedures were filmed. An assistant who was blinded to the study, scored behavior changes using Neonatal/Infant Pain Scale. Heart rate and oxygen saturation levels as displayed on the pulse monitor and duration of crying were recorded using a stopwatch. Findings Mean pain intensity during the intervention v was significantly lower in the case group (P<0.006). Mean pain intensity 3 minutes after intervention was also significantly lower in the case group (P<0.021). Mean duration of crying was significantly lower in case group as well (P<0.001). Conclusion Kangaroo care may be used to decrease pain intensity in newborns undergoing painful procedures. PMID:23056772

  17. Weight-Gain Velocity in Newborn Infants Managed with the Kangaroo Method and Associated Variables.

    PubMed

    Nobre, Raquel Guimarães; de Azevedo, Daniela Vasconcelos; de Almeida, Paulo César; de Almeida, Nádia Maria Girão Saraiva; Feitosa, Francisco Edson de Lucena

    2017-01-01

    Objectives The Kangaroo method helps promote maternal breastfeeding and adequate growth of low birthweight preterm infants. The objective of this study was to analyze the association between weight-gain velocity during use of the Kangaroo method and maternal and infant variables. Methods A nested cross-sectional study in a cohort of newborn infants managed using the Kangaroo method was carried out at a reference center for the method in Brazil. Data on low birthweight and preterm infants managed using the Kangaroo Method (n = 78) and on their respective mothers (n = 70) was collected between January and July 2014. Maternal and infant variables were associated and correlated with weight-gain velocity (g/kg/day) at each phase of the method (p < 0.05). Results Mean weight-gain velocity increased from 0.12 ± 11.11 g/kg/day in the first phase to 13.47 ± 4.84 g/kg/day in the third phase (p < 0.001), and percentage of adequate weight increased at phase 3 (p < 0.001). Birthweight was inversely correlated with weight-gain velocity at phases 1 and 2 of the Kangaroo method. Birthweight of under 1500 g was associated with a lower likelihood of inadequate weight-gain velocity of the newborn at phase 1 (OR = 0.1; 95 % CI 0.01-0.78; p = 0.012). In phase 3, maternal age was directly correlated with weight-gain velocity. Conclusions Weight-gain velocity was associated with maternal (age) and infant (gestational age at birth, birthweight, weight for gestational age at birth, length of hospital stay and five-minute Apgar score) variables. Knowledge of the factors influencing weight-gain velocity and its behavior at each phase of the method can help guide conduct toward potentializing factors that promote adequate weight-gain.

  18. The effect of cryoprotectant on kangaroo sperm ultrastructure and mitochondrial function.

    PubMed

    McClean, Rhett; Holt, William V; Zee, Yeng Peng; Lisle, Allan; Johnston, Stephen D

    2008-12-01

    This study examined the effect of cryoprotectants (20% DMSO, a 10% DMSO/10% glycerol mixture, 20% glycerol and 1M sucrose solution) on kangaroo sperm structure and function, along with the effect of varying concentrations of glycerol on sperm mitochondrial function. Eastern grey kangaroo cauda epididymidal spermatozoa were incubated for 10 min at 35 degrees C in each cryoprotectant and the plasma membrane integrity (PMI) and motility assessed using light microscopy. The same samples were fixed for TEM and the ultrastructural integrity of the spermatozoa examined. To investigate the effect of glycerol on the kangaroo sperm mitochondrial function, epididymidal spermatozoa were incubated with JC-1 in Tris-citrate media at 35 degrees C for 20 min in a range of glycerol concentrations (0%, 5%, 10%, 15% and 20%) and the mitochondrial membrane potential (MMP) and plasma membrane integrity determined. As expected, incubation of spermatozoa in 20% glycerol for 10 min resulted in a significant reduction in motility, PMI and ultrastructural integrity. Interestingly, incubation in 20% DMSO resulted in no significant reduction in motility or PMI but a significant loss of structural integrity when compared to the control spermatozoa (0% cryoprotectant). However, 20% DMSO was overall less damaging to sperm ultrastructure than glycerol, a combination of 10% glycerol and 10% DMSO, and sucrose. While all glycerol concentrations had an adverse effect on mitochondrial function, the statistical models presented for the relationship between MMP and glycerol predicted that spermatozoa, when added to 20% glycerol, would lose half of their initial MMP immediately at 35 degrees C and MMP would halve after 19.4 min at 4 degrees C. Models for the relationship between PMI and glycerol predicted that spermatozoa would lose half of their initial PMI after 1.8 min at 35 degrees C and PMI would halve after 21.1 min at 4 degrees C. These results suggest that if glycerol is to be used as a

  19. A Reproductive Management Program for an Urban Population of Eastern Grey Kangaroos (Macropus giganteus)

    PubMed Central

    Tribe, Andrew; Hanger, Jon; McDonald, Ian J.; Loader, Jo; Nottidge, Ben J.; McKee, Jeff J.; Phillips, Clive J. C.

    2014-01-01

    Simple Summary We designed a programme to control free-ranging kangaroos on a Queensland golf course, using contraceptive implants in females and vasectomisation or testicle removal in males. This reduced the numbers of pouch young to about one half of pre-intervention levels and controlled the population over a 2–4 year period. However, the necessary darting caused a mortality rate of 5–10% of captured animals, mainly due to complications before and after anaesthesia. It is concluded that population control is possible but careful management of kangaroos around the time of anaesthesia induction and recovery is important in such programmes to minimise losses. Abstract Traditionally, culling has been the expedient, most common, and in many cases, the only tool used to control free-ranging kangaroo populations. We applied a reproductive control program to a population of eastern grey kangaroos confined to a golf course in South East Queensland. The program aimed to reduce fecundity sufficiently for the population to decrease over time so that overgrazing of the fairways and the frequency of human–animal conflict situations were minimised. In 2003, 92% of the female kangaroos above 5 kg bodyweight were implanted with the GnRH agonist deslorelin after darting with a dissociative anaesthetic. In 2007, 86% of the females above 5 kg were implanted with deslorelin and also 87% of the males above 5 kg were sterilised by either orchidectomy or vasectomy. In 2005, 2008 and 2009, the population was censused to assess the effect of each treatment. The 2003 deslorelin program resulted in effective zero population growth for approximately 2.5 years. The combined deslorelin–surgery program in 2007 reduced the birth rate from 0.3 to 0.06%/year for 16 months, resulting in a 27% population reduction by November 2009. The results were consistent with implants conferring contraception to 100% of implanted females for at least 12 months. The iatrogenic mortality rates for each

  20. Characterization of the estrous cycle and assessment of reproductive status in Matschie's tree kangaroo (Dendrolagus matschiei) with fecal progestin profiles.

    PubMed

    North, Lindsay A; Harder, John D

    2008-03-01

    The population of Matschie's tree kangaroos (Dendrolagus matschiei) held in North American zoos has declined to critically low numbers, and information on the reproductive biology of tree kangaroos is limited. The objectives of this study were to (1) characterize the temporal features of the estrous cycle through the measurement of fecal progesterone metabolite (i.e., progestin) concentrations and (2) determine the reproductive status of female tree kangaroos in the captive population of North America through the identification of estrous cyclicity. Fecal pellets and observations of estrous behaviors were collected from 16 captive female tree kangaroos. Fecal pellets were sampled and extracted with methanol, and progestin concentrations were quantified using a radioimmunoassay (RIA) for progesterone and its metabolites. A progestin profile was obtained for each female by plotting fecal progestin concentrations for every third day over a 120-day period. Profiles for 12 of 16 females showed evidence of estrous cyclicity (P<0.01). The mean length of the estrous cycle was estimated at 58.9+/-2.4 days (n=11). Progestin concentrations were low during the first 15-20 days of the luteal phase and remained elevated above baseline only during the last 30.2+/-3.2 days of the luteal phase, which averaged 46.6+/-2.5 days in duration. The progestin profile observed in the estrous cycle of Matschie's tree kangaroos in this study is very similar to that seen in the non-pregnant cycle of several other species in the family Macropodidae.

  1. Derivation of soil screening thresholds to protect chisel-toothed kangaroo rat from uranium mine waste in northern Arizona

    USGS Publications Warehouse

    Hinck, Jo E.; Linder, Greg L.; Otton, James K.; Finger, Susan E.; Little, Edward E.; Tillitt, Donald E.

    2013-01-01

    Chemical data from soil and weathered waste material samples collected from five uranium mines north of the Grand Canyon (three reclaimed, one mined but not reclaimed, and one never mined) were used in a screening-level risk analysis for the Arizona chisel-toothed kangaroo rat (Dipodomys microps leucotis); risks from radiation exposure were not evaluated. Dietary toxicity reference values were used to estimate soil-screening thresholds presenting risk to kangaroo rats. Sensitivity analyses indicated that body weight critically affected outcomes of exposed-dose calculations; juvenile kangaroo rats were more sensitive to the inorganic constituent toxicities than adult kangaroo rats. Species-specific soil-screening thresholds were derived for arsenic (137 mg/kg), cadmium (16 mg/kg), copper (1,461 mg/kg), lead (1,143 mg/kg), nickel (771 mg/kg), thallium (1.3 mg/kg), uranium (1,513 mg/kg), and zinc (731 mg/kg) using toxicity reference values that incorporate expected chronic field exposures. Inorganic contaminants in soils within and near the mine areas generally posed minimal risk to kangaroo rats. Most exceedances of soil thresholds were for arsenic and thallium and were associated with weathered mine wastes.

  2. The Kangaroo Program at a Brazilian maternity hospital: the preterm/low-weight babies' health-care under examination.

    PubMed

    Véras, Renata Meira; Traverso-Yépez, Martha

    2011-03-01

    The Kangaroo Program, originally developed in Colombia, was adopted as a public policy by the Brazilian Unified Health System (SUS) in 2000, in an effort to improve maternal and infant health in the country. This article aims to examine the Kangaroo Program as it is practiced and carried out at a maternity hospital in the northeastern Brazilian region. Through an institutional ethnographic approach, research demonstrates that the Kangaroo Program has been effective in saving lives and improving some of the infants' health outcomes. However, research also demonstrates that: (i) the socioeconomic profile of mothers in the Kangaroo Program, (ii) conflicting relationships between healthcare workers and users, and (iii) lack of socioeconomic and emotional support are impairing the adequate implementation of the program. Due to the low literacy level of most of these mothers, institutional power is used as a form of social control to keep mothers uninformed about the possibility of leaving the maternity wards. In a two-tier health system, this controlling behavior is part of existing social inequities, as the Kangaroo Program is a choice in the private health system but tends to be mandatory at SUS maternity hospitals across Brazil.

  3. Kangaroo IGF-II is structurally and functionally similar to the human [Ser29]-IGF-II variant.

    PubMed

    Yandell, C A; Francis, G L; Wheldrake, J F; Upton, Z

    1999-06-01

    Kangaroo IGF-II has been purified from western grey kangaroo (Macropus fuliginosus) serum and characterised in a number of in vitro assays. In addition, the complete cDNA sequence of mature IGF-II has been obtained by reverse-transcription polymerase chain reaction. Comparison of the kangaroo IGF-II cDNA sequence with known IGF-II sequences from other species revealed that it is very similar to the human variant, [Ser29]-hIGF-II. Both the variant and kangaroo IGF-II contain an insert of nine nucleotides that encode the amino acids Leu-Pro-Gly at the junction of the B and C domains of the mature protein. The deduced kangaroo IGF-II protein sequence also contains three other amino acid changes that are not observed in human IGF-II. These amino acid differences share similarities with the changes described in many of the IGF-IIs reported for non-mammalian species. Characterisation of human IGF-II, kangaroo IGF-II, chicken IGF-II and [Ser29]-hIGF-II in a number of in vitro assays revealed that all four proteins are functionally very similar. No significant differences were observed in the ability of the IGF-IIs to bind to the bovine IGF-II/cation-independent mannose 6-phosphate receptor or to stimulate protein synthesis in rat L6 myoblasts. However, differences were observed in their abilities to bind to IGF-binding proteins (IGFBPs) present in human serum. Kangaroo, chicken and [Ser29]-hIGF-II had lower apparent affinities for human IGFBPs than did human IGF-II. Thus, it appears that the major circulating form of IGF-II in the kangaroo and a minor form of IGF-II found in human serum are structurally and functionally very similar. This suggests that the splice site that generates both the variant and major form of human IGF-II must have evolved after the divergence of marsupials from placental mammals.

  4. Molecular phylogenetics of the Diprotodontia (kangaroos, wombats, koala, possums, and allies).

    PubMed

    Osborne, M J; Christidis, L; Norman, J A

    2002-11-01

    Mitochondrial ND2 sequences were used to investigate the phylogenetic relationships amongst 31 diprotodontid marsupials (kangaroos, wombats, koala, possums, and allies). ND2 sequences were analyzed separately and in conjunction with available 12S rDNA sequences for 22 diprotodontid taxa. Phylogenetic analyses consistently identified monophyly for the Burramyoidea, Phalangeroidea, Petauroidea, Tarsipedoidea, Macropodoidea, and the Vombatiformes. Like previous molecular and morphological studies, relationships between the super-families were less well resolved. Inconsistency between taxonomic rank and genetic distance was identified amongst the diprotodontids.

  5. The physics of articulated toys—a jumping and rotating kangaroo

    NASA Astrophysics Data System (ADS)

    Güémez, J.; Fiolhais, M.

    2014-07-01

    We describe the physics of an articulated toy with an internal source of energy provided by a spiral spring. The toy is a funny low cost kangaroo which jumps and rotates. The study consists of mechanical and thermodynamical analyses that make use of the Newton and centre of mass equations, the rotational equations and the first law of thermodynamics. This amazing toy provides a nice demonstrative example of how new physics insights can be brought about when links with thermodynamics are established in the study of mechanical systems.

  6. [Persistent diarrhea

    PubMed

    Andrade, J A; Moreira, C; Fagundes Neto, U

    2000-07-01

    INTRODUCTION: Persistent diarrhea has high impact on infantile morbidity and mortality rates in developing countries. Several studies have shown that 3 to 20% of acute diarrheal episodes in children under 5 years of age become persistent. DEFINITION: Persistent diarrhea is defined as an episode that lasts more than 14 days. ETIOLOGY: The most important agents isolated in persistent diarrhea are: Enteropathogenic E. coli (EPEC), Salmonella, Enteroaggregative E. coli (EAEC), Klebisiella and Cryptosporidium. CLINICAL ASPECTS: In general, the clinical characteristics of patients with persistent diarrhea do not change with the pathogenic agent. Persistent diarrhea seems to represent the final result of a several insults a infant suffers that predisposes to a more severe episode of diarrhea due to a combination of host factors and high rates of enviromental contamination. Therefore, efforts should be made to promptly treat all episodes of diarrhea with apropriate follow-up. THERAPY: The aim of the treatment is to restore hydroelectrolytic deficits and to replace losses until the diarrheal ceases. It is possible in the majority of the cases, using oral rehydration therapy and erly an appropriate type of diet. PREVENTION: It is imperative that management strategies also focus on preventive aspects. The most effective diarrheal prevention strategy in young infants worldwide is promotion of exclusive breast feeding.

  7. Circulating levels of prolactin and progesterone in a wild population of red kangaroos (Macropus rufus) Marsupialia: Macropodidae

    USGS Publications Warehouse

    Muths, E.; Hinds, L. A.

    1996-01-01

    Circulating progesterone and prolactin levels were measured in shot and live-caught wild red kangaroos using radioimmunoassays validated for the red kangaroo. The objective of the study was to correlate hormone profiles with reproductive status and determine if red kangaroos follow the general pattern elucidated for other macropodids. During Phase 2a lactation (<70 days) plasma progesterone concentrations were <189 pg/ml (n= 41). This value increased to >600 pg/ml (n= 32) during the transition to Phase 3 lactation (181 to 235 days) when the quiescent corpus luteum and embryo were reactivated. Progesterone concentrations then decreased to <300 pg/ml (n= 29) during dual lactation when females were suckling a neonate and a young at foot. Concentrations of prolactin during Phase 2a were <6 ng/ml (n= 17). Coincident with the period of reactivation of the diapausing blastocyst (181 to 235 days), plasma prolactin concentrations increased to 15 ng/ml (n= 32), then decreased and remained low through the subsequent stage of dual lactation. These results indicate that progesterone and prolactin profiles in wild red kangaroos follow patterns found previously in other macropodid species, the tammar and Bennett's wallabies.

  8. Brain thermal inertia, but no evidence for selective brain cooling, in free-ranging western grey kangaroos (Macropus fuliginosus).

    PubMed

    Maloney, Shane K; Fuller, Andrea; Meyer, Leith C R; Kamerman, Peter R; Mitchell, Graham; Mitchell, Duncan

    2009-04-01

    Marsupials reportedly can implement selective brain cooling despite lacking a carotid rete. We measured brain (hypothalamic) and carotid arterial blood temperatures every 5 min for 5, 17, and 63 days in spring in three free-living western grey kangaroos. Body temperature was highest during the night, and decreased rapidly early in the morning, reaching a nadir at 10:00. The highest body temperatures recorded occurred sporadically in the afternoon, presumably associated with exercise. Hypothalamic temperature consistently exceeded arterial blood temperature, by an average 0.3 degrees C, except during these afternoon events when hypothalamic temperature lagged behind, and was occasionally lower than, the simultaneous arterial blood temperature. The reversal in temperatures resulted from the thermal inertia of the brain; changes in the brain to arterial blood temperature difference were related to the rate of change of arterial blood temperature on both heating and cooling (P < 0.001 for all three kangaroos). We conclude that these data are not evidence for active selective brain cooling in kangaroos. The effect of thermal inertia on brain temperature is larger than might be expected in the grey kangaroo, a discrepancy that we speculate derives from the unique vascular anatomy of the marsupial brain.

  9. kangaroo, a mobile element from Volvox carteri, is a member of a newly recognized third class of retrotransposons.

    PubMed Central

    Duncan, Leonard; Bouckaert, Kristine; Yeh, Fay; Kirk, David L

    2002-01-01

    Retrotransposons play an important role in the evolution of genomic structure and function. Here we report on the characterization of a novel retrotransposon called kangaroo from the multicellular green alga, Volvox carteri. kangaroo elements are highly mobile and their expression is developmentally regulated. They probably integrate via double-stranded, closed-circle DNA intermediates through the action of an encoded recombinase related to the lambda-site-specific integrase. Phylogenetic analysis indicates that kangaroo elements are closely related to other unorthodox retrotransposons including PAT (from a nematode), DIRS-1 (from Dictyostelium), and DrDIRS1 (from zebrafish). PAT and kangaroo both contain split direct repeat (SDR) termini, and here we show that DIRS-1 and DrDIRS1 elements contain terminal features structurally related to SDRs. Thus, these mobile elements appear to define a third class of retrotransposons (the DIRS1 group) that are unified by common structural features, genes, and integration mechanisms, all of which differ from those of LTR and conventional non-LTR retrotransposons. PMID:12524337

  10. How does the ecological foraging behavior of desert kangaroo rats (Dipodomys deserti) relate to their behavior on radial mazes?

    PubMed

    Timberlake, William; Hoffman, Cynthia M

    2002-11-01

    Experiment 1 showed that laboratory-reared desert kangaroo rats, like domestic Norway rats, efficiently search for food on a radial arm maze (RAM) by avoiding revisiting arms within a trial. By placing an RAM on the floor so the animals could approach food from any direction, Experiment 2 tested whether efficient search by kangaroo rats was based on tactics of distance minimizing, central-place foraging, trail following, or meandering. In contrast to the dominant trail-following tactic of domestic Norway rats (Hoffman, Timberlake, Leffel, & Gont, 1999), kangaroo rats tended to distance minimize, whether maze arms were present or not. Experiment 3 indicated that kangaroo rats treated a floor configuration of eight food cups as two patches of four, based on beeline travel between patches and meandering within them. We conclude that similar performance in an elevated RAM by different species can be based on different tactics, and we suggest that a laboratory apparatus can be used to cast light on niche-related mechanisms.

  11. Purification of a marsupial insulin: amino-acid sequence of insulin from the eastern grey kangaroo Macropus giganteus.

    PubMed

    Treacy, G B; Shaw, D C; Griffiths, M E; Jeffrey, P D

    1989-03-24

    Insulin has been purified from kangaroo pancreas by acidic ethanol extraction, diethyl ether precipitation and gel filtration. The amino-acid sequence of this, the first marsupial insulin to be studied, is reported. It differs from human insulin by only four amino-acid substitutions, all in regions of the molecule previously known to be variable. However, it should be noted that one of these, asparagine for threonine at A8, has not been reported before. Computer comparisons of all 43 insulin sequences reported to date with kangaroo insulin show it to be most closely related to a group of mammalian insulins (dog, pig, cow, human) known to be of high biological potency. The measurement of blood glucose lowering in the rabbit by kangaroo insulin is consistent with this conclusion. Comparisons of amino-acid sequences of other proteins with their kangaroo counterparts show a greater difference, in line with the time of divergence of marsupials. The limited differences observed in insulin and cytochrome c suggest that their structures need to be closely conserved in order to maintain function.

  12. [Cost analysis of hospital care for newborns at risk: comparison of an Intermediate Neonatal Care Unit and a Kangaroo Unit].

    PubMed

    Entringer, Aline Piovezan; Gomes, Maria Auxiliadora de Sousa Mendes; Pinto, Márcia; Caetano, Rosângela; Magluta, Cynthia; Lamy, Zeni Carvalho

    2013-06-01

    The aim of this study was to compare the direct costs of implementation of the Kangaroo Method and an Intermediate Neonatal Care Unit, from the perspective of the Brazilian Unified National Health System (SUS) in Rio de Janeiro, Brazil. Newborns were eligible for inclusion if they were clinically stable and were able to receive care in those two modalities. A decision tree model was developed that incorporated baseline variables and costs into a hypothetical cohort of 1,000 newborns, according to the literature and expert opinions. Daily cost was BR$343.53 for the second stage of the Kangaroo Unit and BR$394.22 for the Intermediate Neonatal Care Unit. The total cost for the hypothetical cohort was BR$5,710,281.66 for the second and third stages of the Kangaroo Unit and R$7,119,865.61 for the Intermediate Neonatal Care Unit. The Intermediate Neonatal Care Unit cost 25% more than the Kangaroo Unit. The study can contribute to decision-making in health, in addition to providing support for studies related to economic evaluation in neonatal health.

  13. Seasonal variation in kangaroo tooth enamel oxygen and carbon isotopes in southern Australia

    NASA Astrophysics Data System (ADS)

    Brookman, Tom H.; Ambrose, Stanley H.

    2012-09-01

    Serial sampling of tooth enamel growth increments for carbon and oxygen isotopic analyses of Macropus (kangaroo) teeth was performed to assess the potential for reconstructing paleoseasonality. The carbon isotope composition of tooth enamel apatite carbonate reflects the proportional intake of C3 and C4 vegetation. The oxygen isotopic composition of enamel reflects that of ingested and metabolic water. Tooth enamel forms sequentially from the tip of the crown to the base, so dietary and environmental changes during the tooth's formation can be detected. δ13C and δ18O values were determined for a series of enamel samples drilled from the 3rd and 4th molars of kangaroos that were collected along a 900 km north-south transect in southern Australia. The serial sampling method did not yield pronounced seasonal isotopic variation patterns in Macropus enamel. The full extent of dietary isotopic variation may be obscured by attenuation of the isotopic signal during enamel mineralisation. Brachydont (low-crowned) Macropus teeth may be less sensitive to seasonal variation in isotopic composition due to time-averaging during mineralisation. However, geographic variations observed suggest that there may be potential for tracking latitudinal shifts in vegetation zones and seasonal environmental patterns in response to climate change.

  14. Studies on the in vitro cultivation of ciliate protozoa from the kangaroo forestomach.

    PubMed

    Dehority, Burk A; Wright, André-Denis G

    2014-08-01

    The methods used for culturing rumen protozoa were found to be unsatisfactory for growth of ciliate protozoa from the kangaroo forestomach. Based on published measurements of physical parameters in the marsupial forestomach, several modifications were incorporated into the procedure, i.e., an increase in % hydrogen in the gas phase, adjustment of initial pH of the medium to 6.9-7.0 range, feed only forage as a substrate and incubate at a lower temperature (33-36 °C). Only incubation at the lower temperature increased survival time of the kangaroo protozoa. Two species of Bitricha were still viable after 28 d in culture. Cultures had to be terminated at that time. One of the species differed considerably in size and shape from previously described species and based on 18S rRNA data, may represent a new species of Bitricha. The second species, present in low numbers was identified as Bitricha oblata. In a separate trial, Macropodinium yalanbense survived for 11 d, at which time these cultures also had to be terminated.

  15. Does Daily Kangaroo Care Provide Sustained Pain and Stress Relief in Preterm Infants?

    PubMed Central

    Mitchell, Anita J.; Yates, Charlotte C.; Williams, D. Keith; Chang, Jason Y.; Hall, Richard Whit

    2014-01-01

    Objectives 1. Determine whether stress in preterm infants, measured with salivary cortisol, decreases after five days of Kangaroo Care (KC) compared to five days of Standard Care (SC). 2. To determine whether kangaroo care provides sustainable pain relief beyond the period of skin-to-skin holding. Study Design Preterm infants (n=38) born at 27-30 weeks gestational age were randomized to either the KC or the SC group and received the allocated intervention starting on day of life (DOL) five and continuing for five days. Salivary cortisol was collected on DOL five and again on DOL ten. Differences were analyzed using repeated measures ANOVA and t tests. Pain during nasal suctioning over five days was assessed using the Premature Infant Pain Profile (PIPP). Result 1. Adequate saliva samples for salivary cortisol were collected for 13 KC infants and 11 SC infants. There was no main effect of group (p=0.49), but there was a significant main effect of age (DOL five versus DOL ten), with salivary cortisol levels decreasing in both groups (p=0.02). 2. Pain scores for both groups (n=38) indicted mild to moderate pain during suctioning, with no significant difference in pain scores between groups. Conclusion 1. KC did not affect salivary cortisol levels in preterm neonates, but levels in both the KC and SC groups decreased over time from DOL five to ten. Salivary cortisol may vary with age of infant. 2. Infants experience pain during routine suctioning and may require pain management. PMID:24246458

  16. Kangaroo (skin-to-skin) care with a preterm infant before, during, and after mechanical ventilation.

    PubMed

    Swinth, Joan Y; Anderson, Gene Cranston; Hadeed, Anthony J

    2003-01-01

    Using kangaroo care (KC) with unstable and/or ventilated infants remains controversial. In this article, potential advantages for ventilated infants and their mothers are discussed. The 33-week-gestation infant in this case study presented with mild respiratory distress at birth, requiring supplemental oxygen at hour 2. With no improvement by hour 18, KC was also begun, first for 1.25 hours and then, 2 hours later, for 3.5 hours. The infant was intubated at hour 45 for increasing respiratory distress, and KC resumed 24 hours later for 1 hour and 3 hours after that for an additional 3 hours. Extubation occurred at hour 90. Kangaroo care resumed 2 hours later for periods of 1.5, 1.5, and 1 hour over the next 8 hours, 2.5 hours more later that day (day 5, the last day of data collection). Thereafter, KC was done intermittently until discharge on day 9. Total KC times for pre-vent, vent, and immediate post-vent periods were 4.75, 4, and 6.5 hours, respectively. The data from this study suggest that KC may assist in, rather than retard, recovery from respiratory distress. KC may also foster maternal relaxation and minimize maternal stress.

  17. Dominance, body size and internal relatedness influence male reproductive success in eastern grey kangaroos (Macropus giganteus).

    PubMed

    Miller, Emily J; Eldridge, Mark D B; Cooper, Desmond W; Herbert, Catherine A

    2010-01-01

    Knowledge of the determinants of reproductive success is essential for understanding the adaptive significance of particular traits. The present study examined whether particular behavioural, morphological, physiological or genetic traits were correlated with male dominance and reproductive success using three semi-free-ranging captive populations (n = 98) of the eastern grey kangaroo (Macropus giganteus). The morphological traits measured included bodyweight, head, forearm, tail, pes and leg length, forearm and bicep circumference, and testis size. Blood samples were collected to determine serum testosterone concentrations. All individuals were typed for 10 microsatellite loci and paternity determined for each pouch young. To determine the influence of relatedness and genetic diversity on male reproductive success, internal relatedness, standardised heterozygosity and mean d(2) were calculated. Dominant males sired a significantly higher proportion of offspring than smaller, lower-ranked males and had higher testosterone concentrations. Males that sired offspring were significantly heavier and had larger body size. Sires were significantly more heterozygous and genetically dissimilar to breeding females than non-sires. Despite the wealth of knowledge on the social organisation of kangaroos, this is the first study to assign parentage and male reproductive success using molecular evidence.

  18. Kangaroo rats exhibit spongiform degeneration of the central auditory system similar to that found in gerbils.

    PubMed

    McGinn, M D; Faddis, B T

    1997-02-01

    Kangaroo rats develop spongiform degeneration of the central auditory system similar to that seen in the gerbil. Light microscopic and transmission electron microscopic study of the cochlear nucleus and auditory nerve root (ANR) of Dipodomys deserti and D. merriami show that spongiform lesions develop in dendrites and oligodendrocytes of the cochlear nucleus and in oligodendrocytes of the ANR that are morphologically indistinguishable from those extensively described in the Mongolian gerbil, Meriones unguiculatus. As in Mongolian gerbils, the spongiform degeneration in Dipodomys were much more numerous in animals continually exposed to modest levels of low-frequency noise (< 75 dB SPL). The kangaroo rats with extensive spongiform degeneration also show slightly, but significantly, elevated auditory brainstem evoked response (ABR) thresholds to low-frequency stimuli, a result also found in Mongolian gerbils. These results suggest that the elevated ABR thresholds may be the result of spongiform degeneration. Because low-frequency noise-induced spongiform degeneration has now been shown in the cochlear nucleus of animals from separate families of Rodentia (Heteromyidae and Muridae), the possibility should be investigated that similar noise-induced degenerative changes occur in the central auditory system of other mammals with good low-frequency hearing.

  19. [Effect of laminin on structural karyotype variability of kangaroo rat kidney cell lines].

    PubMed

    Polianskaia, G G; Goriachaia, T S; Pinaev, G P

    2003-01-01

    The structural karyotypic variability has been investigated in the "markerless" epithelial-like Rat kangaroo kidney cell lines NBL-3-17 and NBL-3-11 on cultivation on a laminin-2/4 coated surface. In cell line NBL-3-17, cultivated on the laminin-coated surface for 2, 4 and 12 days, and in cell line NBL-3-11, cultivated on the laminin-coated surface for 2 and 4 days, there is a significant increase in the frequency of chromosomal aberrations, both chromosomal breaks and dicentrics (telomeric associations). Different sensitivity of individual chromosomes to inducing chromosomal breaks was observed in addition to a preferential involvement of some chromosomes in dicentric formation. Structural instability of chromosomes at cultivation on laminin demonstrates nonspecific reaction of the "markerless" cell lines to unfavourable factors of the environment. We discuss possible reasons of differences in the character of karyotypic variability between a cell line of the Indian muntjac skin fibroblasts and epithelial-like Rat kangaroo kidney cell lines cultivated on laminin.

  20. Unilateral failure of development of mandibular premolars and molars in an Eastern Grey kangaroo (Macropus giganteus) and its effects on molar progression.

    PubMed

    Barber, D; Campbell, J; Davey, J; Luke, T; Agren, E; Beveridge, I

    2008-01-01

    An adult male Eastern Grey kangaroo from a wildlife reserve near Melbourne was submitted for necropsy examination and was discovered to have abnormal dentition. There was no evidence that any premolars or molars had ever been present on the right mandible, whilst the incisors were normal. The age of the kangaroo was estimated to be 1 year 9 months using the right maxillary molars and 2 years 4 months old using the contralateral side, presumably due to the asymmetry of the dental arcades. 'Lumpy jaw', a common periodontal disease of kangaroos, from which Bacteroides sp was cultured, was present on the base of the vertical ramus of the left mandible. Complete unilateral absence of premolar and molar teeth in the mandible of a kangaroo has not been described. This condition affected molar progression in both sets of maxillary molars.

  1. Energy, water and space use by free-living red kangaroos Macropus rufus and domestic sheep Ovis aries in an Australian rangeland.

    PubMed

    Munn, A J; Dawson, T J; McLeod, S R; Dennis, T; Maloney, S K

    2013-08-01

    We used doubly labelled water to measure field metabolic rates (FMR) and water turnover rates (WTR) in one of Australia's largest native herbivores, the red kangaroo (Macropus rufus) and one of Australia's dominant livestock species, the wool-breed Merino sheep, under free-living conditions in a typical Australian rangeland. Also, we used GPS technology to examine animal space use, along with the comparisons of urine concentration, diet, diet digestibility, and subsequent grazing pressures. We found smaller space-use patterns than previously reported for kangaroos, which were between 14 and 25 % those of sheep. The FMR of a 25-kg kangaroo was 30 % that of a 45-kg sheep, while WTR was 15 % and both were associated with smaller travel distances, lower salt intakes, and higher urine concentration in kangaroos than sheep. After accounting for differences in dry matter digestibility of food eaten by kangaroos (51 %) and sheep (58 %), the relative grazing pressure of a standard (mature, non-reproductive) 25-kg kangaroo was 35 % that of a 45-kg sheep. Even for animals of the same body mass (35 kg), the relative grazing pressure of the kangaroo was estimated to be only 44 % that of the sheep. After accounting for the energetic costs of wool growth by sheep, the FMRs of our sheep and kangaroos were 2-3 times their expected BMRs, which is typical for mammalian FMR:BMRs generally. Notably, data collected from our free-living animals were practically identical to those from animals confined to a semi-natural enclosure (collected in an earlier study under comparable environmental conditions), supporting the idea that FMRs are relatively constrained within species.

  2. Semibiotic Persistence

    NASA Astrophysics Data System (ADS)

    Prothmann, C.; Zauner, K.-P.

    From observation, we find four different strategies to successfully enable structures to persist over extended periods of time. If functionally relevant features are very large compared to the changes that can be effectuated by entropy, the functional structure itself has a high enough probability to erode only slowly over time. If the functionally relevant features are protected from environmental influence by sacrificial layers that absorb the impinging of the environment, deterioration can be avoided or slowed. Loss of functionality can be delayed, even for complex systems, by keeping alternate options for all required components available. Biological systems also apply information processing to actively counter the impact of entropy by mechanisms such as self-repair. The latter strategy increases the overall persistence of living systems and enables them to maintain a highly complex functional organisation during their lifetime and over generations. In contrast to the other strategies, information processing has only low material overhead. While at present engineered technology is far from achieving the self-repair of evolved systems, the semibiotic combination of biological components with conventionally engineered systems may open a path to long-term persistence of functional devices in harsh environments. We review nature's strategies for persistence, and consider early steps taken in the laboratory to import such capabilities into engineered architectures.

  3. Sources of carbon isotope variation in kangaroo bone collagen and tooth enamel

    NASA Astrophysics Data System (ADS)

    Murphy, Brett P.; Bowman, David M. J. S.; Gagan, Michael K.

    2007-08-01

    The stable carbon isotopic composition (expressed as δ 13C) of herbivore remains is commonly used to reconstruct past changes in the relative abundance of C 4 versus C 3 grass biomass (C 4 relative abundance). However, the strength of the relationship between herbivore δ 13C and C 4 relative abundance in extant ecosystems has not been thoroughly examined. We determined sources of variation in δ 13C of bone collagen and tooth enamel of kangaroos ( Macropus spp.) collected throughout Australia by measuring δ 13C of bone collagen (779 individuals) and tooth enamel (694 individuals). An index of seasonal water availability, i.e. the distribution of rainfall in the C 4 versus C 3 growing seasons, was used as a proxy for C 4 relative abundance, and this variable explained a large proportion of the variation in both collagen δ 13C (68%) and enamel δ 13C (68%). These figures increased to 78% and 77%, respectively, when differences between kangaroo species were accounted for. Vegetation characteristics, such as woodiness and the presence of an open forest canopy, had no effect on collagen or enamel δ 13C. While there was no relationship between collagen δ 13C and kangaroo age at death, tooth enamel produced later in life, following weaning, was enriched in 13C by 3.5‰ relative to enamel produced prior to weaning. From the observed relationships between seasonal water availability and collagen and enamel δ 13C, enrichment factors ( ɛ∗) for collagen-diet and enamel-diet (post-weaning) were estimated to be 5.2‰ ± 0.5 (95% CI) and 11.7‰ ± 0.6 (95% CI), respectively. The findings of this study confirm that at a continental scale, collagen and enamel δ 13C of a group of large herbivores closely reflect C 4 relative abundance. This validates a fundamental assumption underpinning the use of isotopic analysis of herbivore remains to reconstruct changes in C 4 relative abundance.

  4. Populations at risk: conservation genetics of kangaroo mice (Microdipodops) of the Great Basin Desert.

    PubMed

    Andersen, John J; Portnoy, David S; Hafner, John C; Light, Jessica E

    2013-08-01

    The Great Basin Desert of western North America has experienced frequent habitat alterations due to a complex biogeographic history and recent anthropogenic impacts, with the more recent alterations likely resulting in the decline of native fauna and flora. Dark (Microdipodops megacephalus) and pallid (M. pallidus) kangaroo mice are ecological specialists found within the Great Basin Desert and are potentially ideal organisms for assessing ecosystem health and inferring the biogeographic history of this vulnerable region. Herein, newly acquired nuclear-encoded microsatellite loci were utilized to assess patterns of variation within and among spatially discrete groups of kangaroo mice and to evaluate gene flow, demographic trends, and genetic integrity. Results confirm that there are at least three genetically distinct units within M. megacephalus and two such units within M. pallidus. The three units of M. megacephalus appear to have different demographic histories, with effectively no gene flow among them since their divergence. Similarly, the two units of M. pallidus also appear to have experienced different demographic histories, with effectively no gene exchange. Contemporary effective population sizes of all groups within Microdipodops appear to be low (<500), suggesting that each genetic lineage may have difficulty coping with changing environmental pressures and hence may be at risk of extirpation. Results of this study indicate that each Microdipodops group should be recognized, and therefore managed, as a separate unit in an effort to conserve these highly specialized taxa that contribute to the diversity of the Great Basin Desert ecosystem. The Great Basin Desert of western North America has experienced frequent habitat alterations due to a complex biogeographic history and recent anthropogenic impacts, with the more recent alterations likely resulting in the decline of native fauna and flora. Herein, newly acquired nuclear-encoded microsatellite

  5. Populations at risk: conservation genetics of kangaroo mice (Microdipodops) of the Great Basin Desert

    PubMed Central

    Andersen, John J; Portnoy, David S; Hafner, John C; Light, Jessica E

    2013-01-01

    Abstract The Great Basin Desert of western North America has experienced frequent habitat alterations due to a complex biogeographic history and recent anthropogenic impacts, with the more recent alterations likely resulting in the decline of native fauna and flora. Dark (Microdipodops megacephalus) and pallid (M. pallidus) kangaroo mice are ecological specialists found within the Great Basin Desert and are potentially ideal organisms for assessing ecosystem health and inferring the biogeographic history of this vulnerable region. Herein, newly acquired nuclear-encoded microsatellite loci were utilized to assess patterns of variation within and among spatially discrete groups of kangaroo mice and to evaluate gene flow, demographic trends, and genetic integrity. Results confirm that there are at least three genetically distinct units within M. megacephalus and two such units within M. pallidus. The three units of M. megacephalus appear to have different demographic histories, with effectively no gene flow among them since their divergence. Similarly, the two units of M. pallidus also appear to have experienced different demographic histories, with effectively no gene exchange. Contemporary effective population sizes of all groups within Microdipodops appear to be low (<500), suggesting that each genetic lineage may have difficulty coping with changing environmental pressures and hence may be at risk of extirpation. Results of this study indicate that each Microdipodops group should be recognized, and therefore managed, as a separate unit in an effort to conserve these highly specialized taxa that contribute to the diversity of the Great Basin Desert ecosystem. The Great Basin Desert of western North America has experienced frequent habitat alterations due to a complex biogeographic history and recent anthropogenic impacts, with the more recent alterations likely resulting in the decline of native fauna and flora. Herein, newly acquired nuclear

  6. Cryptosporidium fayeri n. sp. (Apicomplexa: Cryptosporidiidae) from the Red Kangaroo (Macropus rufus).

    PubMed

    Ryan, Una M; Power, Michelle; Xiao, Lihua

    2008-01-01

    The morphology and infectivity of the oocysts of a new species of Cryptosporidium from the faeces of the red kangaroo (Macropus rufus) are described. Oocysts are structurally indistinguishable from those of Cryptosporidium parvum. Oocysts of the new species are passed fully sporulated, lack sporocysts, and measure 4.5-5.1 microm (mean=4.9) x 3.8-5.0 microm (mean=4.3 microm) with a length to width ratio 1.02:1.18 (mean 1.14) (n=50). Oocysts were not infectious for neonate ARC Swiss mice. Multi-locus analysis of numerous unlinked loci demonstrated this species to be distinct (90.64%-97.88% similarity) from C. parvum. Based on biological and molecular data, this Cryptosporidium infecting marsupials is proposed to be a new species Cryptosporidium fayeri n. sp.

  7. [Social representations on breastfeeding according to preterm infants' mothers in Kangaroo Care].

    PubMed

    Javorski, Marly; Caetano, Laise Conceição; Vasconcelos, Maria Gorete Lucena de; Leite, Adriana Moraes; Scochi, Carmen Gracinda Silvan

    2004-01-01

    This study aimed to identify the social representations on premature infants' breastfeeding at a Kangaroo Care Unit, from the perspective of mothers who are breastfeeding and describe the conflicts and contradictions they experience in this context. A qualitative approach was adopted, using the first stage of enunciation analysis in the light of social representations theory to identify the meanings assigned to breastfeeding. We found the following representations: healthy babies are breastfed, mother's milk provides protection and preserves the premature child's life, breastfeeding is the complement of motherhood and breastfeeding a premature infant is a hard and exhausting experience. The conflicts resulted from the assimilation of technical contents and discourse, late sucking and representations on breastfeeding.

  8. Kangaroo care compared to incubators in maintaining body warmth in preterm infants.

    PubMed

    Ludington-Hoe, S M; Nguyen, N; Swinth, J Y; Satyshur, R D

    2000-07-01

    Many preterm infants cared for in incubators do not experience Kangaroo Care (KC), skin-to-skin contact with their mothers, due to fear of body heat loss when being held outside the incubator. A randomized clinical trial of 16 KC and 13 control infants using a pretest-test-posttest design of three consecutive interfeeding intervals of 2.5 to 3.0 h duration each was conducted over 1 day. Infant abdominal and toe temperatures were measured in and out of the incubator; maternal breast temperature was measured during KC. Repeated measures ANOVA showed no change in abdominal temperature across all periods and between groups. Toe temperatures were significantly higher during KC than incubator periods, and maternal breast temperature met each infant's neutral thermal zone requirements within 5 min of onset of KC. Preterm infants similar to those studied here will maintain body warmth with up to 3 h of KC.

  9. Morphology of the lingual papillae in the brush-tailed rat kangaroo.

    PubMed

    Emura, Shoichi; Okumura, Toshihiko; Chen, Huayue

    2014-01-01

    We examined the dorsal lingual surface of an adult brush-tailed rat kangaroo (Bettongia penicillata) by scanning electron microscopy. The filiform and fungiform papillae on the lingual apex and body consisted of a main papilla and secondary papillae. The connective tissue core of the filiform papillae on the lingual apex was cylindrical in shape with a crushed top. The connective tissue core of the filiform papillae on the lingual body had one large and several small processes. The fungiform papillae were round in shape. The connective tissue core of the fungiform papillae had several depressions on its top. The surface of the vallate papillae was rough and the papillae were surrounded by a groove and a pad. Several long conical papillae derived from the posterolateral margin of the tongue where foliate papillae have been shown to be distributed in many other animal species. The long conical papillae were very similar to those of the koala and opossum.

  10. Patterns of heterochromatin replication and condensation correlate in rat kangaroo PtK2 cells.

    PubMed

    Goitein, R; Hirschberg, J; Marcus, M; Sperling, K

    1984-01-01

    Chromosome replication in mammalian cells in an ordered phenomenon. This is true also for the condensation in G2 of the heterochromatic chromosomal regions in mouse cells. The generality of this phenomenon and its mechanism are not known, nor is it known whether the order of condensation of the heterochromatic chromosomal segments in G2 reflects the order of replication or is independent of it. We determined the order of replication during the S phase and of condensation in G2 of the short heterochromatic chromosomal regions in the rat kangaroo cell line PtK2. The kinetics of condensation of these regions in G2 was studied in cells treated with Hoechst 33258. Their order of replication was established with the use of a sensitive technique based on the treatment of living cells with 5-bromodeoxyuridine and Hoechst 33258. Our results show that these regions exhibit a similar pattern of replication in S and condensation in G2.

  11. Ultraviolet-induced cell death is independent of DNA replication in rat kangaroo cells.

    PubMed

    Miyaji, E N; Menck, C F

    1995-05-01

    Rat kangaroo (Potorous tridactylus) cells have an efficient repair system for photoreactivation of lethal lesions induced by 254 nm UV. However, this ability is lost with increasing time after UV, being completely ineffective after 24 h. Critical events leading to UV-induced cell death must occur within this period of time. DNA synthesis was inhibited by the DNA polymerase inhibitor aphidicolin and the loss of the capability to photorepair lethal lesions was maintained as for replicating cells. Similar data were obtained in synchronized cells UV irradiated immediately before S phase. Under the same conditions, the ability to remove cyclobutane pyrimidine dimers by photoreactivation in these cells remained unchanged 24 h after irradiation. These data indicate that the critical events responsible for UV-induced cell death occur in the absence of DNA replication.

  12. Taking kangaroo mother care forward in South Africa: The role of district clinical specialist teams.

    PubMed

    Feucht, Ute Dagmar; van Rooyen, Elise; Skhosana, Rinah; Bergh, Anne-Marie

    2015-11-20

    The global agenda for improved neonatal care includes the scale-up of kangaroo mother care (KMC) services. The establishment of district clinical specialist teams (DCSTs) in South Africa (SA) provides an excellent opportunity to enhance neonatal care at district level and ensure translation of policies, including the requirement for KMC implementation, into everyday clinical practice. Tshwane District in Gauteng Province, SA, has been experiencing an increasing strain on obstetric and neonatal services at central, tertiary and regional hospitals in recent years as a result of growing population numbers and rapid up-referral of patients, with limited down-referral of low-risk patients to district-level services. We describe a successful multidisciplinary quality improvement initiative under the leadership of the Tshwane DCST, in conjunction with experienced local KMC implementers, aimed at expanding the district's KMC services. The project subsequently served as a platform for improvement of other areas of neonatal care by means of a systematic approach.

  13. Parasitic nematode communities of the red kangaroo, Macropus rufus: richness and structuring in captive systems.

    PubMed

    Lott, M J; Hose, G C; Power, M L

    2015-08-01

    Captive management practices have the potential to drastically alter pre-existing host-parasite relationships. This can have profound implications for the health and productivity of threatened species in captivity, even in the absence of clinical symptoms of disease. Maximising the success of captive breeding programmes requires a detailed knowledge of anthropogenic influences on the structure of parasite assemblages in captive systems. In this study, we employed two high-throughput molecular techniques to characterise the parasitic nematode (suborder Strongylida) communities of the red kangaroo, Macropus rufus, across seven captive sites. The first was terminal restriction fragment length polymorphism (T-RFLP) analysis of a region of rDNA encompassing the internal transcribed spacers 1 (ITS1), the 5.8S rRNA gene and the internal transcribed spacer 2 (ITS2). The second was Illumina MiSeq next-generation sequencing of the ITS2 region. The prevalence, intensity of infection, taxonomic composition and comparative structure of strongylid nematode assemblages was assessed at each location. Prevalence (P = <0.001) and mean infection intensity (df = 6, F = 17.494, P = <0.001) differed significantly between the seven captive sites. Significant levels of parasite community structure were observed (ANOSIM, P = 0.01), with most of the variation being distributed within, rather than between, captive sites. The range of nematode taxa that occurred in captive red kangaroos appeared to differ from that of wild conspecifics, with representatives of the genus Cloacina, a dominant nematode parasite of the macropodid forestomach, being detected at only two of the seven study sites. This study also provides the first evidence for the presence of the genus Trichostrongylus in a macropodid marsupial. Our results demonstrate that contemporary species management practices may exert a profound influence on the structure of parasite communities in captive systems.

  14. Stochastic demography and population dynamics in the red kangaroo Macropus rufus.

    PubMed

    Jonzén, Niclas; Pople, Tony; Knape, Jonas; Sköld, Martin

    2010-01-01

    1. Many organisms inhabit strongly fluctuating environments but their demography and population dynamics are often analysed using deterministic models and elasticity analysis, where elasticity is defined as the proportional change in population growth rate caused by a proportional change in a vital rate. Deterministic analyses may not necessarily be informative because large variation in a vital rate with a small deterministic elasticity may affect the population growth rate more than a small change in a less variable vital rate having high deterministic elasticity. 2. We analyse a stochastic environment model of the red kangaroo (Macropus rufus), a species inhabiting an environment characterized by unpredictable and highly variable rainfall, and calculate the elasticity of the stochastic growth rate with respect to the mean and variability in vital rates. 3. Juvenile survival is the most variable vital rate but a proportional change in the mean adult survival rate has a much stronger effect on the stochastic growth rate. 4. Even if changes in average rainfall have a larger impact on population growth rate, increased variability in rainfall may still be important also in long-lived species. The elasticity with respect to the standard deviation of rainfall is comparable to the mean elasticities of all vital rates but the survival in age class 3 because increased variation in rainfall affects both the mean and variability of vital rates. 5. Red kangaroos are harvested and, under the current rainfall pattern, an annual harvest fraction of c. 20% would yield a stochastic growth rate about unity. However, if average rainfall drops by more than c. 10%, any level of harvesting may be unsustainable, emphasizing the need for integrating climate change predictions in population management and increase our understanding of how environmental stochasticity translates into population growth rate.

  15. Biphasic Allometry of Cardiac Growth in the Developing Kangaroo Macropus fuliginosus.

    PubMed

    Snelling, Edward P; Taggart, David A; Maloney, Shane K; Farrell, Anthony P; Seymour, Roger S

    2015-01-01

    Interspecific studies of adult mammals show that heart mass (M(h), g) increases in direct proportion to body mass (M(b), kg), such that M(h) ∝ M(b)(1.00). However, intraspecific studies on heart mass in mammals at different stages of development reveal considerable variation between species, M(h) ∝ M(b)(0.70-1.00). Part of this variation may arise as a result of the narrow body size range of growing placental mammals, from birth to adulthood. Marsupial mammals are born relatively small and offer an opportunity to examine the ontogeny of heart mass over a much broader body size range. Data from 29 western grey kangaroos Macropus fuliginosus spanning 800-fold in body mass (0.084-67.5 kg) reveal the exponent for heart mass decreases significantly when the joey leaves the pouch (ca. 5-6 kg body mass). In the pouch, the heart mass of joeys scales with hyperallometry, M(h(in-pouch)) = 6.39 M(b)(1.10 ± 0.05), whereas in free-roaming juveniles and adults, heart mass scales with hypoallometry, M(h(postpouch)) = 14.2 Mb(0.77 ± 0.08). Measurements of heart height, width, and depth support this finding. The relatively steep heart growth allometry during in-pouch development is consistent with the increase in relative cardiac demands as joeys develop endothermy and the capacity for hopping locomotion. Once out of the pouch, the exponent decreases sharply, possibly because the energy required for hopping is independent of speed, and the efficiency of energy storage during hopping increases as the kangaroo grows. The right:left ventricular mass ratios (0.30-0.35) do not change over the body mass range and are similar to those of other mammals, reflecting the principle of Laplace for the heart.

  16. Experimental manipulation of female reproduction demonstrates its fitness costs in kangaroos.

    PubMed

    Gélin, Uriel; Wilson, Michelle E; Coulson, Graeme; Festa-Bianchet, Marco

    2015-01-01

    When resources are scarce, female mammals should face a trade-off between lactation and other life-history traits such as growth, survival and subsequent reproduction. Kangaroos are ideal to test predictions about reproductive costs because they may simultaneously lactate and carry a young, and have indeterminate growth and a long breeding season. An earlier study in three of our five study populations prevented female eastern grey kangaroos (Macropus giganteus) from reproducing during one reproductive season by either inserting contraceptive implants or removing very small pouch young. We explored how individual and environmental variables affect the costs of reproduction over time, combining this experimental reduction of reproductive effort with multi-year monitoring of 270 marked females. Experimental manipulation should control for individual heterogeneity, revealing the costs of reproduction and their likely sources. We also examined the fitness consequences of reproductive effort and offspring sex among unmanipulated individuals to test whether sex allocation strategies affected trade-offs. Costs of reproduction included longer inter-birth intervals and lower probability of producing a young that survived to 7 months in the subsequent reproductive event. Weaning success, however, did not differ significantly between manipulated and control females. By reducing reproductive effort, manipulation appeared to increase individual condition and subsequent reproductive success. Effects of offspring sex upon subsequent reproductive success varied according to year and study population. Mothers of sons were generally more likely to have a young that survived to 7 months, compared to mothers of daughters. The fitness costs of reproduction arise from constraints in both acquisition and allocation of resources. To meet these costs, females delay subsequent parturition and may manipulate offspring sex. Reproductive tactics thus vary according to the amount of resource

  17. Fleas (Siphonaptera) infesting giant kangaroo rats (Dipodomys ingens) on the Elkhorn and Carrizo Plains, San Luis Obispo County, California.

    PubMed

    Tabor, S P; Williams, D F; Germano, D J; Thomas, R E

    1993-01-01

    The giant kangaroo rat, Dipodomys ingens (Merriam), has a limited distribution in the San Joaquin Valley, CA. Because of reductions in its geographic range, largely resulting from humans, the species was listed as an endangered species in 1980 by the California Fish and Game Commission. As part of a study of the community ecology of southern California endangered species, including D. ingens, we were able to make flea collections from the rats when they were trapped and marked for population studies. All but one of the fleas collected from the D. ingens in this study were Hoplopsyllus anomalus, a flea normally associated with ground squirrels (Sciuridae). It has been suggested that giant kangaroo rats fill the ground squirrel niche within their range. Our data indicate that this role includes a normal association with Hoplopsyllus anomalus.

  18. Mother–offspring distances reflect sex differences in fine-scale genetic structure of eastern grey kangaroos

    PubMed Central

    King, Wendy J; Garant, Dany; Festa-Bianchet, Marco

    2015-01-01

    Natal dispersal affects life history and population biology and causes gene flow. In mammals, dispersal is usually male-biased so that females tend to be philopatric and surrounded by matrilineal kin, which may lead to preferential associations among female kin. Here we combine genetic analyses and behavioral observations to investigate spatial genetic structure and sex-biased dispersal patterns in a high-density population of mammals showing fission–fusion group dynamics. We studied eastern grey kangaroos (Macropus giganteus) over 2 years at Wilsons Promontory National Park, Australia, and found weak fine-scale genetic structure among adult females in both years but no structure among adult males. Immature male kangaroos moved away from their mothers at 18–25 months of age, while immature females remained near their mothers until older. A higher proportion of male (34%) than female (6%) subadults and young adults were observed to disperse, although median distances of detected dispersals were similar for both sexes. Adult females had overlapping ranges that were far wider than the maximum extent of spatial genetic structure found. Female kangaroos, although weakly philopatric, mostly encounter nonrelatives in fission–fusion groups at high density, and therefore kinship is unlikely to strongly affect sociality. PMID:26045958

  19. Bringing compassion to the ethical dilemma in killing kangaroos for conservation: comment on "Conservation through sustainable use" by Rob Irvine.

    PubMed

    Ramp, Daniel

    2013-06-01

    Ethical debate on the killing of kangaroos has polarised conservation and animal welfare science, yet at the heart of these scientific disciplines is the unifying aim of reducing harm to non-human animals. This aim provides the foundation for common ground, culminating in the development of compassionate conservation principles that seek to provide mechanisms for achieving both conservation and welfare goals. However, environmental decision-making is not devoid of human interests, and conservation strategies are commonly employed that suit entrenched positions and commercial gain, rather than valuing the needs of the non-human animals in need of protection. The case study on the wild kangaroo harvest presents just such a dilemma, whereby a conservation strategy is put forward that can only be rationalised by ignoring difficulties in the potential for realising conservation benefits and the considerable welfare cost to kangaroos. Rather than an open debate on the ethics of killing game over livestock, in this response I argue that efforts to bring transparency and objectivity to the public debate have to date been obfuscated by those seeking to maintain entrenched interests. Only by putting aside these interests will debate about the exploitation of wildlife result in humane, compassionate, and substantive conservation benefits.

  20. A survey of the microbiological quality of kangaroo carcasses processed for human consumption in two processing plants in Queensland, Australia.

    PubMed

    Eglezos, Sofroni; Huang, Bixing; Stuttard, Ed

    2007-05-01

    An investigation of the microbiological quality of kangaroo carcasses at two Queensland processing plants was carried out. A total of 836 whole muscle samples were taken, 801 from plant A and 35 from plant B. Samples were analyzed for aerobic bacteria, Escherichia coli, and Salmonella. The mean adjusted aerobic plate count (APC) was 2.8 log CFU/g, and counts at the 90th, 95th, and 99th percentiles were 4.2, 4.9, and 6.4 log CFU/g, respectively. The maximum number of bacteria recovered was 6.5 log CFU/g. E. coli was detected in 13.9% of samples, for which the adjusted mean was 0.7 log CFU/g, and counts at the 90th, 95th, and 99th percentiles were 1.4, 2.0, and 3.0 log CFU/g, respectively. Salmonella was detected in 0.84% of samples. There was no significant relationship (P < 0.05) between season and APC or E. coli count. There was a significant relationship (P < 0.001) between Salmonella prevalence and summer. The microbiological quality of Queensland kangaroo carcasses is similar to that obtained during other excision-based studies of kangaroo, wild boar, and beef carcasses.

  1. Interspecies diversity of the occludin sequence: cDNA cloning of human, mouse, dog, and rat-kangaroo homologues.

    PubMed

    Ando-Akatsuka, Y; Saitou, M; Hirase, T; Kishi, M; Sakakibara, A; Itoh, M; Yonemura, S; Furuse, M; Tsukita, S

    1996-04-01

    Occludin has been identified from chick liver as a novel integral membrane protein localizing at tight junctions (Furuse, M., T. Hirase, M. Itoh, A. Nagafuchi, S. Yonemura, Sa. Tsukita, and Sh. Tsukita. 1993. J. Cell Biol. 123:1777-1788). To analyze and modulate the functions of tight junctions, it would be advantageous to know the mammalian homologues of occludin and their genes. Here we describe the nucleotide sequences of full length cDNAs encoding occludin of rat-kangaroo (potoroo), human, mouse, and dog. Rat-kangaroo occludin cDNA was prepared from RNA isolated from PtK2 cell culture, using a mAb against chicken occludin, whereas the others were amplified by polymerase chain reaction based on the sequence found around the human neuronal apoptosis inhibitory protein gene. The amino acid sequences of the three mammalian (human, murine, and canine) occludins were very closely related to each other (approximately 90% identity), whereas they diverged considerably from those of chicken and rat-kangaroo (approximately 50% identity). Implications of these data and novel experimental options in cell biological research are discussed.

  2. The effects of thyroxine on metabolism and water balance in a desert-dwelling rodent, Merriam's kangaroo rat (Dipodomys merriami).

    PubMed

    Banta, Marilyn R; Holcombe, Dale W

    2002-01-01

    Desert-dwelling mammals such as Merriam's kangaroo rat (Dipodomys merriani) need to conserve both energy and water to survive desert conditions characterized by aridity and low productivity. The thyroid hormone thyroxine increases both basal metabolic rate and urinary water loss in mammals. Increases in basal metabolism and urinary water loss are likely to be detrimental to D. merriami, therefore the regulation of this hormone may be important. To examine the effects of thyroxine in this species, we implanted adult kangaroo rats with pellets designed to release specific doses of thyroxine at a constant rate for 90 days or a placebo pellet. We measured plasma thyroxine concentration, basal metabolic rate, food consumption, urine concentration and water loss in all implanted animals. Thyroxine implants significantly increased both plasma thyroxine and basal metabolic rate in a relatively dose-dependent manner. In response to thyroxine. kangaroo rats increased food consumption only slightly, but this small increase was sufficient to compensate for their elevated metabolic rates. Neither urine concentration nor water loss varied among treatment groups. Thyroxine increased energy expenditure but not water loss in this species.

  3. Radionuclide transport from soil to air, native vegetation, kangaroo rats and grazing cattle on the Nevada test site.

    PubMed

    Gilbert, R O; Shinn, J H; Essington, E H; Tamura, T; Romney, E M; Moor, K S; O'Farrell, T P

    1988-12-01

    Between 1970 and 1986 the Nevada Applied Ecology Group (NAEG), U.S. Department of Energy, conducted environmental radionuclide studies at weapons-testing sites on or adjacent to the Nevada Test Site. In this paper, NAEG studies conducted at two nuclear (fission) sites (NS201, NS219) and two nonnuclear (nonfission) sites (Area 13 [Project 57] and Clean Slate 2) are reviewed, synthesized and compared regarding (1) soil particle-size distribution and physical-chemical characteristics of 239 + 240Pu-bearing radioactive particles, (2) 239 + 240Pu resuspension rates and (3) transuranic and fission-product radionuclide transfers from soil to native vegetation, kangaroo rats and grazing cattle. The data indicate that transuranic radionuclides were transferred more readily on the average from soil to air, the external surfaces of native vegetation and to tissues of kangaroo rats at Area 13 than at NS201 or NS219. The 239 + 240Pu resuspension factor for undisturbed soil at Area 13 was three to four orders-of-magnitude larger than at NS201 and NS219, the geometric mean (GM) vegetation-over-soil 239 + 240Pu concentration ratio was from ten to 100 times larger than at NS201, and the GM GI-over-soil, carcass-over-soil and pelt-over-soil 239 + 240Pu ratios for kangaroo rats were about ten times larger than at NS201. These results are consistent with the finding that Area 13, compared with NS201 or NS219, has a higher percentage of radioactivity associated with smaller soil particles and a larger percentage of resuspendable and respirable soil. However, the resuspension factor increased by a factor of 27 at NS201 when the surface soil was disturbed, and by a factor of 12 at NS219 following a wildfire. The average (GM) concentration of 239 + 240Pu for the GI (and contents) of Area 13 kangaroo rats and for the rumen contents of beef cattle that grazed Area 13 were very similar (400 vs. 440 Bq kg-1 dry wt, respectively) although the variability between individuals was very large. The

  4. Derivation of soil-screening thresholds to protect the chisel-toothed kangaroo rat from uranium mine waste in northern Arizona.

    PubMed

    Hinck, Jo Ellen; Linder, Greg; Otton, James K; Finger, Susan E; Little, Edward; Tillitt, Donald E

    2013-08-01

    Chemical data from soil and weathered waste material samples collected from five uranium mines north of the Grand Canyon (three reclaimed, one mined but not reclaimed, and one never mined) were used in a screening-level risk analysis for the Arizona chisel-toothed kangaroo rat (Dipodomys microps leucotis); risks from radiation exposure were not evaluated. Dietary toxicity reference values were used to estimate soil-screening thresholds presenting risk to kangaroo rats. Sensitivity analyses indicated that body weight critically affected outcomes of exposed-dose calculations; juvenile kangaroo rats were more sensitive to the inorganic constituent toxicities than adult kangaroo rats. Species-specific soil-screening thresholds were derived for arsenic (137 mg/kg), cadmium (16 mg/kg), copper (1,461 mg/kg), lead (1,143 mg/kg), nickel (771 mg/kg), thallium (1.3 mg/kg), uranium (1,513 mg/kg), and zinc (731 mg/kg) using toxicity reference values that incorporate expected chronic field exposures. Inorganic contaminants in soils within and near the mine areas generally posed minimal risk to kangaroo rats. Most exceedances of soil thresholds were for arsenic and thallium and were associated with weathered mine wastes.

  5. Serologic-based investigation of leptospirosis in a population of free-ranging eastern grey kangaroos (Macropus giganteus) indicating the presence of Leptospira weilii serovar Topaz.

    PubMed

    Roberts, Michael W; Smythe, Lee; Dohnt, Michael; Symonds, Meegan; Slack, Andrew

    2010-04-01

    Eastern grey kangaroos (Macropus giganteus) are one of the most abundant large macropodids sharing the landscape with humans. Despite this, little is known about the prevalence of Leptospira carriage within this species and the role that they may partake in the transmission of this disease in Australia. The sera of 87 free-ranging eastern grey kangaroos, captured in the Warragamba Catchment Area, Sydney, Australia, from June 2004 to November 2006, were screened against a reference panel of 22 Leptospira serovars using the microscopic agglutination test (MAT). Leptospiral antibodies were detected in 47% (41 of 87) of serum samples collected. Leptospira weilii Topaz, a newly emergent serovar in Australia, was detected in all seropositive kangaroos (41 of 41; 100%). The sex and tail-fat body condition index of kangaroos appeared to have no significant effect on the exposure to the disease. This serologic-based study is the first reported for L. weilii serovar Topaz in New South Wales, to our knowledge, having previously been isolated only in humans and two other animal species (bovine and long-nosed bandicoot [Perameles nasuta]) in Western Australia and Queensland. The potential role of eastern grey kangaroos in the maintenance and zoonotic spread of the disease to livestock and humans is discussed.

  6. Ord's kangaroo rats living in floodplain habitats: Factors contributing to habitat attraction

    USGS Publications Warehouse

    Miller, M.S.; Wilson, K.R.; Andersen, D.C.

    2003-01-01

    High densities of an aridland granivore, Ord's kangaroo rat (Dipodomys ordii), have been documented in floodplain habitats along the Yampa River in northwestern Colorado. Despite a high probability of inundation and attendant high mortality during the spring flood period, the habitat is consistently recolonized. To understand factors that potentially make riparian habitats attractive to D. ordii, we compared density and spatial pattern of seeds, density of a competitor (western harvester ant, Pogonomyrmex occidentalis), and digging energetics within floodplain habitats and between floodplain and adjacent upland habitats. Seed density within the floodplain was greatest in the topographically high (rarely flooded) floodplain and lowest immediately after a spring flood in the topographically low (frequently flooded) floodplain. Seed densities in adjacent upland habitat that never floods were higher than the lowest floodplain habitat. In the low floodplain prior to flooding, seeds had a clumped spatial pattern, which D. ordii is adept at exploiting; after spring flooding, a more random pattern resulted. Populations of the western harvester ant were low in the floodplain relative to the upland. Digging by D. ordii was energetically less expensive in floodplain areas than in upland areas. Despite the potential for mortality due to annual spring flooding, the combination of less competition from harvester ants and lower energetic costs of digging might promote the use of floodplain habitat by D. ordii.

  7. Short spell kangaroo mother care and its differential physiological influence in subgroups of preterm babies.

    PubMed

    Boju, Sangeetha Lakshmi; Gopi Krishna, Muddu; Uppala, Rajani; Chodavarapu, Praneeta; Chodavarapu, Ravikumar

    2012-06-01

    In routine practice, 4-6 h of kangaroo mother care (KMC) is adopted. Many mothers feel the duration impracticable. In 86 preterm babies, pre and post 1 h KMC changes in heart rate (HR), respiratory rate (RR), axillary temperature and SpO(2) are measured, in each baby. Postnatal age at the time of the study is 7.7 ± 5.2 days. Significant changes observed are decrease in mean HR by 3 bpm, RR by 3 min(-1) and increase in mean axillary temperature by 0.4 F and SpO(2) by 1.1%. In SGA babies, post KMC decrease in mean HR by 5 bpm, increase in mean axillary temperature by 0.6 F and SpO(2) by 2.1% are significant. In female babies, post KMC decrease in mean RR by 6 min(-1) and increase mean axillary temperature by 0.3 F and SpO(2) by 1.5% are significant. We conclude that preterm babies are benefited by 1 h KMC. SGA and female preterm babies showed different and greater response.

  8. The effect of kangaroo mother care on mental health of mothers with low birth weight infants

    PubMed Central

    Badiee, Zohreh; Faramarzi, Salar; MiriZadeh, Tahereh

    2014-01-01

    Background: The mothers of premature infants are at risk of psychological stress because of separation from their infants. One of the methods influencing the maternal mental health in the postpartum period is kangaroo mother care (KMC). This study was conducted to evaluate the effect of KMC of low birth weight infants on their maternal mental health. Materials and Methods: The study was conducted in the Department of Pediatrics of Isfahan University of Medical Sciences, Isfahan, Iran. Premature infants were randomly allocated into two groups. The control group received standard caring in the incubator. In the experimental group, caring with three sessions of 60 min KMC daily for 1 week was practiced. Mental health scores of the mothers were evaluated by using the 28-item General Health Questionnaire. Statistical analysis was performed by the analysis of covariance using SPSS. Results: The scores of 50 infant-mother pairs were analyzed totally (25 in KMC group and 25 in standard care group). Results of covariance analysis showed the positive effects of KMC on the rate of maternal mental health scores. There were statistically significant differences between the mean scores of the experimental group and control subjects in the posttest period (P < 0.001). Conclusion: KMC for low birth weight infants is a safe way to improve maternal mental health. Therefore, it is suggested as a useful method that can be recommended for improving the mental health of mothers. PMID:25371871

  9. Effects of Daily Kangaroo Care on Cardiorespiratory Parameters in Preterm Infants

    PubMed Central

    Mitchell, Anita J.; Yates, Charlotte; Williams, Keith; Hall, Richard W

    2014-01-01

    Background/aims Kangaroo care (KC) has possible benefits for promoting physiological stability and positive developmental outcomes in preterm infants. The purpose of this study was to compare bradycardia and desaturation events in preterm infants in standard incubator care (SC) versus KC. Methods Thirty-eight infants 27 to 30 weeks gestational age were randomly assigned to 2 hours of KC daily between days of life (DOL) 5 to 10 or to continuous SC. Infants were monitored for bradycardia (heart rate <80) or oxygen desaturation (<80%). Analysis of hourly events was based on three sets of data: SC group 24 hours daily, KC group during incubator time 22 hours daily, and KC group during holding time 2 hours daily. Results The KC group had fewer bradycardia events per hour while being held compared to time spent in an incubator (p=0.048). The KC group also had significantly fewer oxygen desaturation events while being held than while in the incubator (p=0.017) and significantly fewer desaturation events than infants in standard care (p=0.02). Conclusion KC reduces bradycardia and oxygen desaturation events in preterm infants, providing physiological stability and possible benefits for neurodevelopmental outcomes. PMID:24246597

  10. [Effect of very early kangaroo care on extrauterine temperature adaptation in newborn infants with hypothermia problems].

    PubMed

    Huang, Ya-Yi; Huang, Ching-Yi; Lin, Shiu-Mei; Wu, Shu-Chuan

    2006-08-01

    Increased morbidity and mortality has been associated with neonates admitted with body temperatures below 36 degrees C. We employed an experimental design in a randomized control trial to compare the effectiveness of using early kangaroo care (KC) for extrauterine temperature adaptation against that of using radiant warmers. Trial subjects included 78 consecutive cesarean newborn infants with hypothermia problems. The KC group received skin-to-skin contact with their mothers in the post-operative room, while infants in the control group received routine care under radiant warmers. The mean temperature of the KC group was slightly higher than that of the control group (36.29 degrees C vs. 36.22 degrees C, p = .044). After four hours, 97.43% of KC group infants had reached normal body temperatures, compared with 82.05% in the radiant warmer group. Results demonstrate the positive effects of KC for extrauterine temperature adaptation in hypothermia infants. In the course of evidence-based practice, KC could be incorporated into the standard care regimen in order to improve hypothermia care.

  11. Single-strand conformation polymorphism analysis of genetic variation in Labiostrongylus longispicularis from kangaroos.

    PubMed

    Huby-Chilton, F; Beveridge, I; Gasser, R B; Chilton, N B

    2001-06-01

    Single-strand conformation polymorphism (SSCP) analysis was employed to screen for sequence heterogeneity in the second internal transcribed spacer (ITS-2) of ribosomal (r) DNA of Labiostrongylus longispicularis, a parasitic strongylid nematode occuring in some species of kangaroo in different geographical regions of Australia. The results showed that most of the nematodes screened had different SSCP profiles, which were subsequently shown to correspond to polymorphisms and/or an indel in the ITS-2 sequence. These variable sites related mainly to unpaired regions of the predicted secondary structure of the precursor rRNA molecule. SSCP profiles could be used to distinguish L. longispicularis in Macropus robustus robustus (New South Wales) from L. longispicularis in Macropus robustus erubescens and Macropus rufus (South Australia). This difference corresponded to a transversional change in the ITS-2 sequence at alignment position 82. The study demonstrated clearly the effectiveness of SSCP analysis for future large-scale population genetic studies of L. longispicularis in order to test the hypothesis that L. longispicularis from different geographical regions represents multiple sibling species.

  12. Family-level relationships among the Australasian marsupial "herbivores" (Diprotodontia: Koala, wombats, kangaroos and possums).

    PubMed

    Phillips, Matthew J; Pratt, Renae C

    2008-02-01

    The marsupial order Diprotodontia includes 10 extant families, which occupy all terrestrial habitats across Australia and New Guinea and have evolved remarkable dietary and locomotory diversity. Despite considerable attention, the interrelations of these families have for the most part remained elusive. In this study, we separately model mitochondrial RNA and protein-coding sequences in addition to nuclear protein-coding sequences to provide near-complete resolution of diprotodontian family-level phylogeny. We show that alternative topologies inferred in some previous studies are likely to be artifactual, resulting from branch-length and compositional biases. Subordinal groupings resolved herein include Vombatiformes (wombats and koala) and Phalangerida, which in turn comprises Petauroidea (petaurid gliders and striped, feathertail, ringtail and honey possums) and a clade whose plesiomorphic members possess blade-like premolars (phalangerid possums, kangaroos and their allies and most likely, pygmy possums). The topology resolved reveals ecological niche structuring among diprotodontians that has likely been maintained for more than 40 million years.

  13. [Characteristics of quantitative karyotypic variability in cell line of kidney from rat kangaroo (Potorous tridactylis)].

    PubMed

    Polianskaia, G G; Samokish, V A

    1999-01-01

    The numerical regulations of karyotypic variability in cell line of rat kangaroo kidney, NBL-3-11, has been investigated. These regulations are similar with ones found for cell lines of the Indian muntjac skin fibroblasts (M, MT, M2). In particular the balanced karyotypic structure of cell population in vitro is determined by correlations of the structural variants of the karyotype (SVK). These correlations depend on the following regulations 1) nonrandom character of cell distribution according to the number of chromosomal deviations from MSVK; 2) specific character of deviations of each chromosome from MSVK; 3) presence of significant connections between separate chromosomes with simultaneous numeral deviations some differences in the character of significant connections between the individual chromosomes. These connections have either single directed character, mainly (+) direction, or differently directed one by deviations of each chromosome mainly in one direction in cell line NBL-3-11. At the same time single directed character of simultaneous deviations is observed in cell lines of the Indian muntjac skin fibroblasts (M, MT, M2) either in (+) or (-) direction. Represented results confirm and extend considerably the known ideas of the regulations of karyotypic variability in cell populations in vitro.

  14. Behavioural syndromes in Merriam's kangaroo rats (Dipodomys merriami): a test of competing hypotheses.

    PubMed

    Dochtermann, Ned A; Jenkins, Stephen H

    2007-09-22

    Behavioural syndromes, correlations of behaviours conceptually analogous to personalities, have been a topic of recent attention due to their potential to explain trade-offs in behavioural responses, apparently maladaptive behaviour and limits to plasticity. Using Merriam's kangaroo rats (Dipodomys merriami), we assessed the explanatory power and generality of hypothesized syndrome structures derived from the literature and the natural history of the species. Several aspects of functionally distinct behavioural responses of D. merriami were quantified. Syndrome structures were compared using structural equation modelling and model selection procedures. A domain-general behavioural syndrome incorporating cross-functional relationships between measures of boldness, agonistic behaviour, flexibility and food hoarding best explained the data. This pattern suggests that D. merriami behaviours should not be viewed as discrete elements but as components of a multivariate landscape. Our results support arguments that a lack of independence between behaviours may be a general aspect of behavioural phenotypes and suggest that the ability of D. merriami's behaviour to respond to selection may be constrained by underlying connections.

  15. Vasoconstrictors alter oxygen, lactate, and glycerol metabolism in the perfused hindlimb of a rat kangaroo.

    PubMed

    Ye, J M; Edwards, S J; Rose, R W; Rattigan, S; Clark, M G; Colquhoun, E Q

    1995-05-01

    The Tasmanian bettong (Bettongia gaimardi) is a small marsupial rat kangaroo without detectable brown adipose tissue (BAT). The hindlimb was perfused with constant flow at 25 degrees C after cannulation under anesthesia of the femoral artery and vein to one hindlimb. Norepinephrine (NE, 25 nM-2.5 microM) and vasopressin (VP, 10 nM-0.1 microM) each increased perfusion pressure, oxygen consumption (VO2), and lactate and glycerol efflux of the perfused hindlimb. NE-mediated increases in VO2 and the efflux of lactate and glycerol were unaffected by propranolol (10 microM) but were completely blocked by the further addition of phentolamine (10 microM). In contrast, serotonin (5-HT; 0.1-2.5 microM) inhibited VO2 and inhibited lactate efflux. The changes induced by NE, VP, and 5-HT were all rapidly reversed by nitroprusside. These results suggest that resting thermogenesis in bettong hindlimb can be differentially controlled by the vasculature, which may also contribute to the induced VO2. This vascular control of skeletal muscle VO2 appears widespread in homeotherm evolution.

  16. A flow cytometric study of chromosomes from rat kangaroo and Chinese hamster cells.

    PubMed

    Stöhr, M; Hutter, K J; Frank, M; Futterman, G; Goerttler, K

    1980-01-01

    Chromosomes from rat kangaroo (PTK) and chinese hamster (CHV 79) cells have been prepared for quantitative flow-cytometric analysis. The preparation time was otimized down to 30 (PTK) and 40 min (CHV 79). DAPI was used as a AT-sensitive fluorescent dye to stain for monoparameter DNA measurements. Simultaneous two-parameter DNA-protein analysis was carried out with DAPI and SR 101 (as a general protein fluorochrome) in combination. The karyotype of the PTK cells with 13 (14) chromosomes was separated into 10DNA peaks. The X-chromosome bearing the nucleolus organizer region generates a distinct peak. The karyotype of the CHV 79 cells with 22 chromosomes was separated inot 15 peaks. The DNA profile obtained indicates a geometric grading of the chromosomal amount of AT components in teh karyotype of this particular cell line. The simultaneous DNA-protein analysis performed show enough sensitivity of the instrument utilizing hihg power UV excitation illumination to discriminate the two color emission consisting of blue (DAPI) and red (SR 101) fluorescence. Color overlapping could be completely avoided. Additionally, the quality (number, location, and resolution of peaks) of the DNA distribution was not influences by the simultaneous application of a second fluorescent stain. Fluorescence activated electronic sorting applied on chromosomal fluorescence distributions providing purified fractions of chromosomes for subsequent biochemical and biological determinations is discussed.

  17. Speed cameras, section control, and kangaroo jumps-a meta-analysis.

    PubMed

    Høye, Alena

    2014-12-01

    A meta-analysis was conducted of the effects of speed cameras and section control (point-to-point speed cameras) on crashes. 63 effect estimates from 15 speed camera studies and five effect estimates from four section control studies were included in the analysis. Speed cameras were found to reduce total crash numbers by about 20%. The effect declines with increasing distance from the camera location. Fatal crashes were found to be reduced by 51%, this result may however be affected by regression to the mean (RTM). Section control was found to have a greater crash reducing effect than speed cameras (-30% for total crash numbers and -56% for KSI crashes). There is no indication that these results (except the one for the effect of speed cameras on fatal crashes) are affected by regression to the mean, publication bias or outlier bias. The results indicate that kangaroo driving (braking and accelerating) occurs, but no adverse effects on speed or crashes were found. Crash migration, i.e., an increase of crash numbers on other roads due to rerouting of traffic, may occur in some cases at speed cameras, but the results do not indicate that such effects are common. Both speed cameras and section control were found to achieve considerable speed reductions and the crash effects that were found in meta-analysis are of a similar size or greater than one might expect based on the effects on speed.

  18. Biological assessment of the effects of petroleum production activities, Naval Petroleum Reserves in California, on the endangered giant kangaroo rat, Dipodomys ingens

    SciTech Connect

    O'Farrell, T.P.; Kato, T.T.

    1987-09-01

    This Biological Assessment evaluates the potential adverse effects that production activities conducted on the Naval Petroleum Reserveys in California may have on the endangered giant kangaroo rat (Dipodomys ingens). DOE concluded that the direct, indirect, and cumulative effects of the proposed activities will not jeopardize the continued existence of the species because results of surveys indicated that giant kangaroo rat burrow systems and habitat was initiated; a habitat restoration program was developed and implemented; and administrative policies to reduce vehicle speeds, contain oil and waste water spills, restrict off-road vehicle travel, and to regulate public access, livestock grazing, and agricultural activities were maintained. 33 refs., 3 figs.

  19. Successful transfer of a Goodfellow's tree kangaroo (Dendrolagus goodfellowi) pouch young to a yellow-footed rock wallaby (Petrogale xanthopus) surrogate.

    PubMed

    McLelland, David J; Fielder, Kate; Males, Gayl; Langley, Nathan; Schultz, David

    2015-01-01

    A 47-day-old orphaned Goodfellow's tree kangaroo (Dendrolagus goodfellowi) joey was successfully cross-fostered onto a yellow-footed rock wallaby (Petrogale xanthopus). The joey was subsequently taken for hand-rearing at age 5 months. This is the first report of the cross-fostering technique, well-established in other macropods, being applied to a Dendrolagus sp. This technique can be considered as a viable option to raise young orphaned tree kangaroos, and as a tool to accelerate breeding in captive breeding programs of Dendrolagus spp.

  20. Kangaroo tooth enamel oxygen and carbon isotope variation on a latitudinal transect in southern Australia: implications for palaeoenvironmental reconstruction.

    PubMed

    Brookman, Tom H; Ambrose, Stanley H

    2013-02-01

    Tooth enamel apatite carbonate carbon and oxygen isotope ratios of modern kangaroos (Macropus spp.) collected on a 900-km latitudinal transect spanning a C(3)-C(4) transition zone were analysed to create a reference set for palaeoenvironmental reconstruction in southern Australia. The carbon isotope composition of enamel carbonate reflects the proportional intake of C(3) and C(4) vegetation, and its oxygen isotope composition reflects that of ingested water. Tooth enamel forms incrementally, recording dietary and environmental changes during mineralisation. Analyses show only weak correlations between climate records and latitudinal changes in δ(13)C and δ(18)O. No species achieved the δ(13)C values (~-1.0 ‰) expected for 100 % C(4) grazing diets; kangaroos at low latitudes that are classified as feeding primarily on C(4) grasses (grazers) have δ(13)C of up to -3.5 ‰. In these areas, δ(13)C below -12 ‰ suggests a 100 % C(3) grass and/or leafy plant (browse) diet while animals from higher latitude have lower δ(13)C. Animals from semi-arid areas have δ(18)O of 34-40 ‰, while grazers from temperate areas have lower values (~28-30 ‰). Three patterns with implications for palaeoenvironmental reconstruction emerge: (1) all species in semi-arid areas regularly browse to supplement limited grass resources; (2) all species within an environmental zone have similar carbon and oxygen isotope compositions, meaning data from different kangaroo species can be pooled for palaeoenvironmental investigations; (3) relatively small regional environmental differences can be distinguished when δ(13)C and δ(18)O data are used together. These data demonstrate that diet-isotope and climate-isotope relationships should be evaluated in modern ecosystems before application to the regional fossil record.

  1. Radionuclide transport from soil to air, native vegetation, kangaroo rats and grazing cattle on the Nevada test site

    SciTech Connect

    Gilbert, R.O.; Shinn, J.H.; Essington, E.H.; Tamura, T.; Romney, E.M.; Moor, K.S.; O'Farrell, T.P.

    1988-12-01

    Between 1970 and 1986 the Nevada Applied Ecology Group (NAEG), U.S. Department of Energy, conducted environmental radionuclide studies at weapons-testing sites on or adjacent to the Nevada Test Site. In this paper, NAEG studies conducted at two nuclear (fission) sites (NS201, NS219) and two nonnuclear (nonfission) sites (Area 13 (Project 57) and Clean Slate 2) are reviewed, synthesized and compared regarding (1) soil particle-size distribution and physical-chemical characteristics of 239 + 240Pu-bearing radioactive particles, (2) 239 + 240Pu resuspension rates and (3) transuranic and fission-product radionuclide transfers from soil to native vegetation, kangaroo rats and grazing cattle. The data indicate that transuranic radionuclides were transferred more readily on the average from soil to air, the external surfaces of native vegetation and to tissues of kangaroo rats at Area 13 than at NS201 or NS219. The 239 + 240Pu resuspension factor for undisturbed soil at Area 13 was three to four orders-of-magnitude larger than at NS201 and NS219, the geometric mean (GM) vegetation-over-soil 239 + 240Pu concentration ratio was from ten to 100 times larger than at NS201, and the GM GI-over-soil, carcass-over-soil and pelt-over-soil 239 + 240Pu ratios for kangaroo rats were about ten times larger than at NS201. These results are consistent with the finding that Area 13, compared with NS201 or NS219, has a higher percentage of radioactivity associated with smaller soil particles and a larger percentage of resuspendable and respirable soil. However, the resuspension factor increased by a factor of 27 at NS201 when the surface soil was disturbed, and by a factor of 12 at NS219 following a wildfire.

  2. Polycyclic hydrocarbon biomarkers confirm selective incorporation of petroleum in kangaroo rat liver samples near oil well blowout site

    SciTech Connect

    Kaplan, I.; Lu, Shan-tan; Lee, Ru-po; Warrick, G.

    1996-12-31

    In June 1994, a well blowout occurred at an oil field in the western, part of the San Joaquin Valley, resulting in deposition of crude oil south of the well. Some light oil spray was found up to 13.6 km from the well, but the most heavily affected area was within 0.8 km of the site. Because the location contains habitats for several threatened and endangered species, an evaluation of damages to natural resources was initiated soon after the well was capped. As part of the assessment of damages to wildlife, an investigation was conducted to determine whether kangaroo rats had ingested crude oil hydrocarbons from the spill.

  3. Phylogeography of the dark kangaroo mouse, Microdipodops megacephalus: cryptic lineages and dispersal routes in North America's Great Basin

    PubMed Central

    Hafner, John C; Upham, Nathan S

    2011-01-01

    Aim The rodent genus Microdipodops (kangaroo mice) includes two sand-obligate endemics of the Great Basin Desert: M. megacephalus and M. pallidus. The dark kangaroo mouse, M. megacephalus, is distributed throughout the Great Basin and our principal aims were to formulate phylogenetic hypotheses for this taxon and make phylogeographical comparisons with its congener. Location The Great Basin Desert of western North America. Methods DNA sequence data from three mitochondrial genes were examined from 186 individuals of M. megacephalus, representing 47 general localities. Phylogenetic inference was used to analyse the sequence data. Directional analysis of phylogeographical patterns was used to examine haplotype sharing patterns and recover routes of gene exchange. Haplotype–area curves were constructed to evaluate the relationship between genetic variation and distributional island size for M. megacephalus and M. pallidus. Results Microdipodops megacephalus is a rare desert rodent (trapping success was 2.67%). Temporal comparison of trapping data shows that kangaroo mice are becoming less abundant in the study area. The distribution has changed slightly since the 1930s but many northern populations now appear to be small, fragmented, or locally extinct. Four principal phylogroups (the Idaho isolate and the western, central and eastern clades) are evident; mean sequence divergence between phylogroups for cytochrome b is c. 8%. Data from haplotype sharing show two trends: a north–south trend and a web-shaped trend. Analyses of haplotype–area curves reveal significant positive relationships. Main conclusions The four phylogroups of M. megacephalus appear to represent morphologically cryptic species; in comparison, a companion study revealed two cryptic lineages in M. pallidus. Estimated divergence times of the principal clades of M. megacephalus (c. 2–4 Ma) indicate that these kangaroo mice were Pleistocene invaders into the Great Basin coincident with the

  4. Phylogeography of the dark kangaroo mouse, Microdipodops megacephalus: cryptic lineages and dispersal routes in North America's Great Basin.

    PubMed

    Hafner, John C; Upham, Nathan S

    2011-06-01

    AIM: The rodent genus Microdipodops (kangaroo mice) includes two sand-obligate endemics of the Great Basin Desert: M. megacephalus and M. pallidus. The dark kangaroo mouse, M. megacephalus, is distributed throughout the Great Basin and our principal aims were to formulate phylogenetic hypotheses for this taxon and make phylogeographical comparisons with its congener. LOCATION: The Great Basin Desert of western North America. METHODS: DNA sequence data from three mitochondrial genes were examined from 186 individuals of M. megacephalus, representing 47 general localities. Phylogenetic inference was used to analyse the sequence data. Directional analysis of phylogeographical patterns was used to examine haplotype sharing patterns and recover routes of gene exchange. Haplotype-area curves were constructed to evaluate the relationship between genetic variation and distributional island size for M. megacephalus and M. pallidus. RESULTS: Microdipodops megacephalus is a rare desert rodent (trapping success was 2.67%). Temporal comparison of trapping data shows that kangaroo mice are becoming less abundant in the study area. The distribution has changed slightly since the 1930s but many northern populations now appear to be small, fragmented, or locally extinct. Four principal phylogroups (the Idaho isolate and the western, central and eastern clades) are evident; mean sequence divergence between phylogroups for cytochrome b is c. 8%. Data from haplotype sharing show two trends: a north-south trend and a web-shaped trend. Analyses of haplotype-area curves reveal significant positive relationships. MAIN CONCLUSIONS: The four phylogroups of M. megacephalus appear to represent morphologically cryptic species; in comparison, a companion study revealed two cryptic lineages in M. pallidus. Estimated divergence times of the principal clades of M. megacephalus (c. 2-4 Ma) indicate that these kangaroo mice were Pleistocene invaders into the Great Basin coincident with the formation

  5. Design of a breathing mattress based on the respiratory movement of kangaroo mother care for the development of neonates.

    PubMed

    Schets, M W M; Chen, W; Bambang Oetomo, S

    2015-01-01

    Kangaroo mother care (KMC) benefits the development of neonates. This paper focuses on the design and implementing the extension of KMC for infants at Neonatal Intensive Care Units (NICU). A breathing mattress is proposed to comfort infants and stimulate them to breathe regularly by mimicking the movement of the parent's chest during KMC. The incubator mattress simulates the breathing of the parent's chest with embedded electronics and pneumatic technology for mattress motion actuating systems. The stakeholders, including the child, parents and NICU staff, were directly involved during the concept development, prototyping and evaluation.

  6. A survey to detect the presence of Mycobacterium avium subspecies paratuberculosis in Kangaroo Island macropods.

    PubMed

    Cleland, P C; Lehmann, D R; Phillips, P H; Cousins, D V; Reddacliff, L A; Whittington, R J

    2010-10-26

    The aim of this study was to determine whether Mycobacterium avium subspecies paratuberculosis (M. a. paratuberculosis) infection was present in macropods grazing with infected sheep on Kangaroo Island in 2001-2002, and to assess the likely role of such infection in the epidemiology of ovine paratuberculosis. Ileum and associated lymphatics from 482 macropods were examined using radiometric culture followed by PCR for IS900 and restriction endonuclease analysis (REA) for species identification, and isolates were strain typed using PCR for IS1311 and REA. Ileum and mesenteric lymph nodes from animals with positive tissue cultures or gross lesions suggestive of paratuberculosis were examined histologically. Faeces from a total of 840 animals were cultured in pools of 20, and individual faecal cultures were done from tissue culture positive animals, from those with microscopic lesions, and from selected animals with gross lesions. Eight animals (1.7%) yielded positive tissue cultures, and all isolates were the sheep (S) strain. Two animals that were tissue culture positive also had histopathological evidence of paratuberculosis. Twelve culture negative animals had microscopic lesions consistent with mycobacterial infection, and M. genavense was identified by PCR from a paraffin block from one of these animals. All faecal cultures were negative. These results indicate that a small proportion of macropods can become infected with M. a. paratuberculosis when grazing with infected sheep. However, excretion of large numbers of viable organisms is rare in macropods, and it is unlikely that macropods provide a wildlife reservoir of infection that would seriously compromise control efforts for paratuberculosis in sheep.

  7. Randomized controlled trial of music during kangaroo care on maternal state anxiety and preterm infants' responses.

    PubMed

    Lai, Hui-Ling; Chen, Chia-Jung; Peng, Tai-Chu; Chang, Fwu-Mei; Hsieh, Mei-Lin; Huang, Hsiao-Yen; Chang, Shu-Chuan

    2006-02-01

    The purpose of this randomized controlled trial was to investigate the influences of music during kangaroo care (KC) on maternal anxiety and preterm infants' responses. There are no experimental studies that explore the influences of combination of music and KC on psychophysiological responses in mother-infant dyads. Purposive sampling was used to recruit 30 hospitalized preterm infants body weight 1500 gm and over, gestational age 37 weeks and lower from two NICUs. Mother-infant dyads were randomly assigned to the treatment and the control group using permuted block randomization stratified on gender. There were 15 mother-infant dyads in each group. Subjects in the treatment dyads listened to their choice of a lullaby music during KC for 60 min/section/day for three consecutive days. Control dyads received routine incubator care. Using a repeated measures design with a pretest and three posttests, the responses of treatment dyads including maternal anxiety and infants' physiologic responses (heart rate, respiratory rate, and O2 saturation) as well as behavioural state were measured. The results revealed that there were no significant differences between the two groups on infants' physiologic responses and the values were all in the normal range. However, infants in the treatment group had more occurrence of quiet sleep states and less crying (p<0.05-0.01). Music during KC also resulted in significantly lower maternal anxiety in the treatment group (p<0.01). Maternal state anxiety improved daily, indicating a cumulative dose effect. The findings provide evidence for the use of music during KC as an empirically-based intervention for bahavioural state stability and maternal anxiety in mother-infant dyads.

  8. Evaluation of retinopathy of prematurity screening in reverse Kangaroo Mother Care: a pilot study

    PubMed Central

    Padhi, T R; Sareen, D; Pradhan, L; Jalali, S; Sutar, S; Das, T; Modi, R R; Behera, U C

    2015-01-01

    Purpose To evaluate retinopathy of prematurity (ROP) screening practice in reverse Kangaroo Mother Care (R-KMC) with respect to stress and pain to the infant. Methods In a pilot study we evaluated ROP screening practice in R-KMC in 20 babies at risk of ROP. The R-KMC differed from the conventional KMC with respect to the baby position where the baby lay supine on mother's chest. With the mother lying supine and the baby in R-KMC position, screening examinations were done with indirect ophthalmoscope. The outcome measures included stress (quantified by pulse, respiration, and oxygen saturation) and pain to the baby by observing facial expression (eye squeezing, crying, and brow bulge). The heart rate, respiratory rate, and SpO2 (%) were compared before and immediately after the procedure using paired t-test. Result Mean (±SD) gestational age and birth weight were 30.8±2.3 weeks and 1362.5±253.9 g, respectively. During examination in R- KMC position 8 babies (40%) were completely relaxed (no eye squeezing and crying), 10 (50%) were partially relaxed (no brow bulge) and 2 babies (10%) were not relaxed. A change in heart and respiration rate both by 10 per minute was recorded in 12 (60%) and 10 (50%) babies, respectively. Five babies (25%) had reduction in blood oxygen concentration below 92%. The majority of the mothers (19 of 20) were relaxed. Conclusion ROP screening in R-KMC can be a baby friendly screening practice with respect to stress and pain to the infant and needs further evaluation in a larger cohort. PMID:25613847

  9. Effect of Kangaroo Mother Care on Vital Physiological Parameters of The Low Birth Weight Newborn

    PubMed Central

    Bera, Alpanamayi; Ghosh, Jagabandhu; Singh, Arun Kumarendu; Hazra, Avijit; Som, Tapas; Munian, Dinesh

    2014-01-01

    Objectives: Low birth weight (LBW; <2500 g), which is often associated with preterm birth, is a common problem in India. Both are recognized risk factors for neonatal mortality. Kangaroo mother care (KMC) is a non-conventional, low-cost method for newborn care based upon intimate skin-to-skin contact between mother and baby. Our objective was to assess physiological state of LBW babies before and after KMC in a teaching hospital setting. Materials and Methods: Study cohort comprised in-born LBW babies and their mothers - 300 mother-baby pairs were selected through purposive sampling. Initially, KMC was started for 1 hour duration (at a stretch) on first day and then increased by 1 hour each day for next 2 days. Axillary temperature, respiration rate (RR/ min), heart rate (HR/ min), and oxygen saturation (SpO2) were assessed for 3 consecutive days, immediately before and after KMC. Results: Data from 265 mother-baby pairs were analyzed. Improvements occurred in all 4 recorded physiological parameters during the KMC sessions. Mean temperature rose by about 0.4°C, RR by 3 per minute, HR by 5 bpm, and SpO2 by 5% following KMC sessions. Although modest, these changes were statistically significant on all 3 days. Individual abnormalities (e.g. hypothermia, bradycardia, tachycardia, low SpO2) were often corrected during the KMC sessions. Conclusions: Babies receiving KMC showed modest but statistically significant improvement in vital physiological parameters on all 3 days. Thus, without using special equipment, the KMC strategy can offer improved care to LBW babies. These findings support wider implementation of this strategy. PMID:25364150

  10. Investigating Differences in Vigilance Tactic Use within and between the Sexes in Eastern Grey Kangaroos

    PubMed Central

    Rieucau, Guillaume; Blanchard, Pierrick; Martin, Julien G. A.; Favreau, François-René; Goldizen, Anne W.; Pays, Olivier

    2012-01-01

    Aggregation is thought to enhance an animal’s security through effective predator detection and the dilution of risk. A decline in individual vigilance as group size increases is commonly reported in the literature and called the group size effect. However, to date, most of the research has only been directed toward examining whether this effect occurs at the population level. Few studies have explored the specific contributions of predator detection and risk dilution and the basis of individual differences in the use of vigilance tactics. We tested whether male and female (non-reproductive or with young) eastern grey kangaroos (Macropus giganteus) adopted different vigilance tactics when in mixed-sex groups and varied in their reliance on predator detection and/or risk dilution as group size changed. This species exhibits pronounced sexual dimorphism with females being much smaller than males, making them differentially vulnerable toward predators. We combined field observations with vigilance models describing the effects of detection and dilution on scanning rates as group size increased. We found that females with and without juveniles relied on predator detection and risk dilution, but the latter adjusted their vigilance to the proportion of females with juveniles within their group. Two models appeared to equally support the data for males suggesting that males, similarly to females, relied on predator detection and risk dilution but may also have adjusted their vigilance according to the proportion of mothers within their group. Differential vulnerability may cause sex differences in vigilance tactic use in this species. The presence of males within a group that do not, or only partially, contribute to predator detection and are less at risk may cause additional security costs to females. Our results call for reexamination of the classical view of the safety advantages of grouping to provide a more detailed functional interpretation of gregariousness. PMID

  11. Interactions among social monitoring, anti-predator vigilance and group size in eastern grey kangaroos

    PubMed Central

    Favreau, François-René; Goldizen, Anne W.; Pays, Olivier

    2010-01-01

    Group size is known to affect both the amount of time that prey animals spend in vigilance and the degree to which the vigilance of group members is synchronized. However, the variation in group-size effects reported in the literature is not yet understood. Prey animals exhibit vigilance both to protect themselves against predators and to monitor other group members, and both forms of vigilance presumably influence group-size effects on vigilance. However, our understanding of the patterns of individual investment underlying the time sharing between anti-predator and social vigilance is still limited. We studied patterns of variation in individual vigilance and the synchronization of vigilance with group size in a wild population of eastern grey kangaroos (Macropus giganteus) subject to predation, in particular focusing on peripheral females because we expected that they would exhibit both social and anti-predator vigilance. There was no global effect of group size on individual vigilance. The lack of group-size effect was the result of two compensating effects. The proportion of time individuals spent looking at other group members increased, whereas the proportion of time they spent scanning the environment decreased with group size; as a result, overall vigilance levels did not change with group size. Moreover, a degree of synchrony of vigilance occurred within groups and that degree increased with the proportion of vigilance time peripheral females spent in anti-predator vigilance. Our results highlight the crucial roles of both social and anti-predator components of vigilance in the understanding of the relationship between group size and vigilance, as well as in the synchronization of vigilance among group members. PMID:20219737

  12. The mood variation in mothers of preterm infants in Kangaroo mother care and conventional incubator care.

    PubMed

    de Macedo, Elizeu Coutinho; Cruvinel, Fernando; Lukasova, Katerina; D'Antino, Maria Eloisa Famá

    2007-10-01

    Preterm babies are more prone to develop disorders and so require immediate intensive care. In the conventional neonatal intensive care, the baby is kept in the incubator, separated from the mother. Some actions have been taken in order to make this mother-child separation less traumatic. One of these actions is the Kangaroo mother care (KMC) characterized by skin-to-skin contact between a mother and her newborn. The objective of this study was to compare the mood variation of mothers enrolled in the KMC program to those in the conventional incubator care. In one general hospital in Sao Paulo, Brazil, 90 mothers were evaluated before and after contact with the baby in the Neonatal Intensive Care Unit. The participants were divided into three groups: 30 mothers of term newborns (TG), 30 mothers of preterm infants included in KMC program (PGK) and 30 preterms with incubator placement (PGI). The Brazilian version of the Visual Analogue Mood Scale (VAMS) was used for the assessment before and after the infant's visit. Results showed that TG mothers reported fewer occurrences of depressive states than PGK and PGI mothers. A significant mood variation was observed for PGK and PGI after the infant's visit. PGK mothers reported feeling calmer, stronger, well-coordinated, energetic, contented, tranquil, quick-witted, relaxed, proficient, happy, friendly and clear-headed. The only variation showed by PGI mothers was an increase in feeling clumsy. This study shows a positive effect of the KMC on the mood variation of preterm mothers and points to the need of a more humane experience during the incubator care.

  13. Barriers and enablers of kangaroo mother care practice: a systematic review.

    PubMed

    Seidman, Gabriel; Unnikrishnan, Shalini; Kenny, Emma; Myslinski, Scott; Cairns-Smith, Sarah; Mulligan, Brian; Engmann, Cyril

    2015-01-01

    Kangaroo mother care (KMC) is an evidence-based approach to reducing mortality and morbidity in preterm infants. Although KMC is a key intervention package in newborn health initiatives, there is limited systematic information available on the barriers to KMC practice that mothers and other stakeholders face while practicing KMC. This systematic review sought to identify the most frequently reported barriers to KMC practice for mothers, fathers, and health practitioners, as well as the most frequently reported enablers to practice for mothers. We searched nine electronic databases and relevant reference lists for publications reporting barriers or enablers to KMC practice. We identified 1,264 unique publications, of which 103 were included based on pre-specified criteria. Publications were scanned for all barriers / enablers. Each publication was also categorized based on its approach to identification of barriers / enablers, and more weight was assigned to publications which had systematically sought to understand factors influencing KMC practice. Four of the top five ranked barriers to KMC practice for mothers were resource-related: "Issues with the facility environment / resources," "negative impressions of staff attitudes or interactions with staff," "lack of help with KMC practice or other obligations," and "low awareness of KMC / infant health." Considering only publications from low- and middle-income countries, "pain / fatigue" was ranked higher than when considering all publications. Top enablers to practice were included "mother-infant attachment" and "support from family, friends, and other mentors." Our findings suggest that mother can understand and enjoy KMC, and it has benefits for mothers, infants, and families. However, continuous KMC may be physically and emotionally difficult, and often requires support from family members, health practitioners, or other mothers. These findings can serve as a starting point for researchers and program

  14. A nested PCR for the ssrRNA gene detects Trypanosoma binneyi in the platypus and Trypanosoma sp. in wombats and kangaroos in Australia.

    PubMed

    Noyes, H A; Stevens, J R; Teixeira, M; Phelan, J; Holz, P

    1999-02-01

    Trypanosome infections in their natural hosts are frequently difficult to detect by microscopy, and culture methods are unreliable and not suitable for all species of Trypanosoma. A nested PCR strategy for detecting and identifying Trypanosoma species, suitable for detecting both known and unknown trypanosomes, is presented. Thirty-two blood samples from 23 species of Australian birds and mammals were screened by a nested PCR for the presence of Trypanosoma sp. ssrRNA. Three infections were detected, one in an eastern grey kangaroo (Macropus giganteus), one in a common wombat (Vombatus ursinus) and one in a platypus (Ornithorhynchus anatinus). The kangaroo and wombat are new host records for Trypanosoma sp.; the platypus parasite was Trypanosoma hinneyi. The three parasites could be distinguished by restriction fragment length polymorphisms of the amplified fragment of the ssrRNA gene. The kangaroo and wombat parasites were also isolated in a semi-solid blood agar medium. The culture forms of the kangaroo trypanosome had an expanded flagellar sheath in which structures similar to hemidesmosomes were detected by EM. The nested PCR was at least as sensitive as culture, and analysis of the PCR products gave parasite-specific fingerprints. Therefore this method could be suitable for rapidly screening host animals for the presence of trypanosomes and identifying the infecting strain.

  15. Isolation and characterization of a novel herpesvirus from a free-ranging eastern grey kangaroo (Macropus giganteus).

    PubMed

    Vaz, Paola Karinna; Motha, Julian; McCowan, Christina; Ficorilli, Nino; Whiteley, Pam Lizette; Wilks, Colin Reginald; Hartley, Carol Anne; Gilkerson, James Rudkin; Browning, Glenn Francis; Devlin, Joanne Maree

    2013-01-01

    We isolated a macropodid herpesvirus from a free-ranging eastern grey kangaroo (Macropus giganteous) displaying clinical signs of respiratory disease and possibly neurologic disease. Sequence analysis of the herpesvirus glycoprotein G (gG) and glycoprotein B (gB) genes revealed that the virus was an alphaherpesvirus most closely related to macropodid herpesvirus 2 (MaHV-2) with 82.7% gG and 94.6% gB amino acid sequence identity. Serologic analyses showed similar cross-neutralization patterns to those of MaHV-2. The two viruses had different growth characteristics in cell culture. Most notably, this virus formed significantly larger plaques and extensive syncytia when compared with MaHV-2. No syncytia were observed for MaHV-2. Restriction endonuclease analysis of whole viral genomes demonstrated distinct restriction endonuclease cleavage patterns for all three macropodid herpesviruses. These studies suggest that a distinct macropodid alphaherpesvirus may be capable of infecting and causing disease in eastern grey kangaroos.

  16. Changing patterns of meat consumption and greenhouse gas emissions in Australia: Will kangaroo meat make a difference?

    PubMed

    Ratnasiri, Shyama; Bandara, Jayatilleke

    2017-01-01

    The Australian per capita consumption of ruminant meat such as beef and lamb has declined over the last two decades. Over the same period, however, per capita consumption of non-ruminant meat such as chicken and pork has continued to increase. Furthermore, it is now observed that the human consumption of kangaroo meat is on the rise. This study investigates the implications of these changes in meat consumption patterns on Green House Gases (GHGs) emission mitigation in Australia using a Vector Auto Regression (VAR) forecasting approach. Our results suggest that the increase will continue in non-ruminant meat consumption and this will not only offset the decline in ruminant meat consumption, but will also raise the overall per capita meat consumption by approximately 1% annually. The per capita GHGs emissions will likely decrease by approximately 2.3% per annum, due to the inclusion of non-ruminant meat in Australian diets. The GHGs emissions can further be reduced if the average Australian consumer partially replaces ruminant meat with kangaroo meat.

  17. Changing patterns of meat consumption and greenhouse gas emissions in Australia: Will kangaroo meat make a difference?

    PubMed Central

    Ratnasiri, Shyama; Bandara, Jayatilleke

    2017-01-01

    The Australian per capita consumption of ruminant meat such as beef and lamb has declined over the last two decades. Over the same period, however, per capita consumption of non-ruminant meat such as chicken and pork has continued to increase. Furthermore, it is now observed that the human consumption of kangaroo meat is on the rise. This study investigates the implications of these changes in meat consumption patterns on Green House Gases (GHGs) emission mitigation in Australia using a Vector Auto Regression (VAR) forecasting approach. Our results suggest that the increase will continue in non-ruminant meat consumption and this will not only offset the decline in ruminant meat consumption, but will also raise the overall per capita meat consumption by approximately 1% annually. The per capita GHGs emissions will likely decrease by approximately 2.3% per annum, due to the inclusion of non-ruminant meat in Australian diets. The GHGs emissions can further be reduced if the average Australian consumer partially replaces ruminant meat with kangaroo meat. PMID:28196141

  18. Low-frequency distortion product otoacoustic emissions in two species of kangaroo rats: implications for auditory sensitivity.

    PubMed

    Shaffer, L A; Long, G R

    2004-01-01

    Low-frequency distortion-product otoacoustic emissions were measured in two species of kangaroo rats to test the prediction that a large footdrumming species (e.g., Dipodomys spectabilis) would have greater distortion-product otoacoustic emission amplitude than a small non-footdrumming species (e.g., Dipodomys merriami), indicating better hearing sensitivity at low frequencies. Equal-level (65 dB SPL) stimulus tones ( f(1), f(2)), presented over a ( f(1)) range of 200-1000 Hz, were used to evoke the 2 f(1)- f(2) distortion-product otoacoustic emission. Mean 2 f(1)- f(2) levels for D. merriami showed good correspondence to previously published audiograms for that species. Mean 2 f(1)- f(2) levels and 95% confidence intervals indicated species differences below 400 Hz, supporting the theory that low-frequency hearing sensitivity is better in large kangaroo rat species. These results suggest that the size-related divergence in footdrumming behavior may be related to differential auditory sensitivity.

  19. Aerobic characteristics of red kangaroo skeletal muscles: is a high aerobic capacity matched by muscle mitochondrial and capillary morphology as in placental mammals?

    PubMed

    Dawson, Terence J; Mifsud, Brock; Raad, Matthew C; Webster, Koa N

    2004-07-01

    Marsupials and placentals together comprise the Theria, the advanced mammals, but they have had long independent evolutionary histories, with the last common ancestor occurring more than 125 million years ago. Although in the past the marsupials were considered to be metabolically 'primitive', the red kangaroo Macropus rufus has been reported to have an aerobic capacity (VO2max) comparable to that of the most 'athletic' of placentals such as dogs. However, kangaroos travel at moderate speeds with lower relative cost than quadrupedal placentals. Given the long independent evolution of the two therian groups, and their unusual locomotor energetics, do kangaroos achieve their high aerobic capacity using the same structural and functional mechanisms used by (athletic) placentals? Red kangaroo skeletal muscle morphometry matched closely the general aerobic characteristics of placental mammals. The relationship between total mitochondrial volume in skeletal muscle and VO2max during exercise was identical to that in quadrupedal placentals, and differed from that in bipedal humans. As for placentals generally, red kangaroo mitochondrial oxygen consumption at VO2max was 4.7 ml O2 min(-1) ml(-1) of mitochondria. Also, the inner mitochondrial membrane densities were 35.8 +/- 0.7 m2 ml(-1) of mitochondria, which is the same as for placental mammals, and the same pattern of similarity was seen for capillary densities and volumes. The overall data for kangaroos was equivalent to that seen in athletic placentals such as dogs and pronghorns. Total skeletal muscle mass was high, being around 50% of body mass, and was concentrated around the pelvis and lower back. The majority of the muscles sampled had relatively high mitochondrial volume densities, in the range 8.8-10.6% in the major locomotor muscles. Again, capillary densities and capillary blood volumes followed the pattern seen for mitochondria. Our results indicate that the red kangaroo, despite its locomotion and extreme

  20. A micro case study of the legal and administrative arrangements for river health in the Kangaroo River (NSW).

    PubMed

    Mooney, C; Farrier, D

    2002-01-01

    Kangaroo Valley is a drinking water supply catchment for Kangaroo Valley village, parts of the Southern Highlands and Sydney. It is also a popular recreation area both for swimming and canoeing. Land use has traditionally been dominated by dairy farming but there has been significant and continuing development of land for hobby farms and rural residential subdivision. Dairy industry restructuring has affected the viability of some farms in the Valley and created additional pressure for subdivision. River health is a function of flows, water quality, riparian vegetation, geomorphology and aquatic habitat and riverine biota. River flows in the Kangaroo River are affected by water extraction and storage for urban water supply and extraction by commercial irrigators and riparian land holders which have a significant impact at low flows. Current water quality often does not meet ANZECC Guidelines for primary contact and recreation and the river is a poor source of raw drinking water. Key sources of contaminants are wastewater runoff from agriculture, and poorly performing on-site sewage management systems. Riparian vegetation, which is critical to the maintenance of in-stream ecosystems suffers from uncontrolled stock access and weed infestation. The management of land use and resulting diffuse pollution sources is critical to the long term health of the river. The Healthy Rivers Commission of New South Wales Independent Inquiry into the Shoalhaven River System Final Report July, 1999 found that the longer term protection of the health of the Kangaroo River is contingent upon achievement of patterns of land use that have regard to land capability and also to the capability of the river to withstand the impacts of inappropriate or poorly managed land uses. This micro case study of Kangaroo Valley examines the complex legal and administrative arrangements with particular reference to the management of diffuse pollution for river health. In the past, diffuse pollution has

  1. Effect of Kangaroo Mother Care on physical growth, breastfeeding and its acceptability.

    PubMed

    Gathwala, Geeta; Singh, Bir; Singh, Jagjit

    2010-10-01

    The aim of this study was to determine whether the implementation of Kangaroo Mother Care (KMC) to low birth weight infants would improve physical growth, breastfeeding and its acceptability. A randomized controlled trial was performed over 16 months in which 110 neonates were randomized into a KMC group and a control group using a random number table. The KMC group was subjected to KMC for at least 6 h per day. The babies also received KMC after moving from the neonatal intensive care unit and at home. The control group received standard care (incubator or open care system). Weight, length and occipitofrontal circumference (OFC) were measured weekly for three months. The acceptability of KMC by mothers and nursing staff was assessed on day 7 after the start of KMC using a questionnaire incorporating the Likert scale. Breastfeeding rates were calculated based on history at end of three months. The mean gestational age was 35.48 ± 1.20 weeks in the KMC group and 35.04 ± 1.09 weeks in the control group (P > 0.05). KMC was initiated at a mean age of 1.72 ± 0.45 days and the duration of KMC was 9.74 ± 1.48 h/day. The mean birth weight was 1.69 ± 0.11 kg in the KMC group compared to 1.69 ± 0.12 kg in the control group (P > 0.05). The mean weight gain in gm/day in the KMC group was 21.92 ± 1.44 compared to 18.61 ± 1.28 in the control group (P < 0.05). The mean length gain in cm/week was 1.03 ± 0.5 in the KMC group compared to 0.74 ± 0.05 in the control group (P < 0.05). The mean OFC gain in cm/week was 0.59 ± 0.04 in the KMC group compared to 0.47 ± 0.03 in the control group (P < 0.05). The exclusive breast-feeding rate at end of three months was 88% in the KMC group compared to 72% in the control group (P < 0.05). KMC improved physical growth, breastfeeding rates and was well accepted by both mothers and nursing staff.

  2. Long Term Outcomes of Kangaroo Mother Care in Very Low Birth Weight Infants

    PubMed Central

    Eklare, Deepak; Mohammad, Haseeb

    2016-01-01

    Introduction Kangaroo Mother Care (KMC) has been gaining acceptance as an effective alternative to incubator based Conventional Medical Care (CMC) in preterm or Low Birth Weight (LBW) infants especially in resource scarce developing countries. Aim To report and analyse the long-term effects of KMC for relatively stable Very Low Birth Weight (VLBW) infants on nutritional indicators and feeding conditions at 6–12 months of corrected age. Materials and Methods This randomized controlled trial was done at a Level III Neonatal Intensive Care Unit (NICU) of a teaching institution in southern India. One hundred and forty neonates with birth weight <1500gm were enrolled. Inborn singleton, VLBW (birth weight <1500gm) infants, tolerating spoon feeds of 150mL/kg/day and haemodynamically stable (not on oxygen or respiratory support, no apnea for 72 hours, not on any intravenous fluids) were eligible. Infants with major malformation were excluded. Babies were randomized to KMC group or CMC group. At 6 to 12 months corrected age, the assessment included the measurement of growth parameters in terms of malnutrition, wasting, stunting and having small head. Feeding information was collected in relation to duration of exclusive or partial breastfeeding (months of chronological age and of corrected age), the age (chronological age and corrected age) at which weaning diet was started and the type of weaning diet. Comparisons between study groups for primary outcomes and secondary outcomes were performed with Odds Ratio (OR) calculator using Medcalc online statistical software. Results A total of 91 infants were followed at 6–12 months of corrected age. There was no difference between two groups in the incidence of malnutrition, wasting, stunting and having small head (47.7% vs 31.9%, p-0.13), (34.1% vs. 31.9%, p-0.83), (22.7% vs 12.8%, p-0.22) and (18.2% vs.31.9%, p-0.14). Although KMC group babies had better head growth and lesser weight and length compared to the CMC group, it

  3. Kangaroo mother care: a multi-country analysis of health system bottlenecks and potential solutions

    PubMed Central

    2015-01-01

    Background Preterm birth is now the leading cause of under-five child deaths worldwide with one million direct deaths plus approximately another million where preterm is a risk factor for neonatal deaths due to other causes. There is strong evidence that kangaroo mother care (KMC) reduces mortality among babies with birth weight <2000 g (mostly preterm). KMC involves continuous skin-to-skin contact, breastfeeding support, and promotion of early hospital discharge with follow-up. The World Health Organization has endorsed KMC for stabilised newborns in health facilities in both high-income and low-resource settings. The objectives of this paper are to: (1) use a 12-country analysis to explore health system bottlenecks affecting the scale-up of KMC; (2) propose solutions to the most significant bottlenecks; and (3) outline priority actions for scale-up. Methods The bottleneck analysis tool was applied in 12 countries in Africa and Asia as part of the Every Newborn Action Plan process. Country workshops involved technical experts to complete the survey tool, which is designed to synthesise and grade health system "bottlenecks", factors that hinder the scale-up, of maternal-newborn intervention packages. We used quantitative and qualitative methods to analyse the bottleneck data, combined with literature review, to present priority bottlenecks and actions relevant to different health system building blocks for KMC. Results Marked differences were found in the perceived severity of health system bottlenecks between Asian and African countries, with the former reporting more significant or very major bottlenecks for KMC with respect to all the health system building blocks. Community ownership and health financing bottlenecks were significant or very major bottlenecks for KMC in both low and high mortality contexts, particularly in South Asia. Significant bottlenecks were also reported for leadership and governance and health workforce building blocks. Conclusions There

  4. Kangaroo mother care diminishes pain from heel lance in very preterm neonates: A crossover trial

    PubMed Central

    Johnston, C Celeste; Filion, Francoise; Campbell-Yeo, Marsha; Goulet, Celine; Bell, Linda; McNaughton, Kathryn; Byron, Jasmine; Aita, Marilyn; Finley, G Allen; Walker, Claire-Dominique

    2008-01-01

    Background Skin-to-skin contact, or kangaroo mother care (KMC) has been shown to be efficacious in diminishing pain response to heel lance in full term and moderately preterm neonates. The purpose of this study was to determine if KMC would also be efficacious in very preterm neonates. Methods Preterm neonates (n = 61) between 28 0/7 and 31 6/7 weeks gestational age in three Level III NICU's in Canada comprised the sample. A single-blind randomized crossover design was employed. In the experimental condition, the infant was held in KMC for 15 minutes prior to and throughout heel lance procedure. In the control condition, the infant was in prone position swaddled in a blanket in the incubator. The primary outcome was the Premature Infant Pain Profile (PIPP), which is comprised of three facial actions, maximum heart rate, minimum oxygen saturation levels from baseline in 30-second blocks from heel lance. The secondary outcome was time to recover, defined as heart rate return to baseline. Continuous video, heart rate and oxygen saturation monitoring were recorded with event markers during the procedure and were subsequently analyzed. Repeated measures analysis-of-variance was employed to generate results. Results PIPP scores at 90 seconds post lance were significantly lower in the KMC condition (8.871 (95%CI 7.852–9.889) versus 10.677 (95%CI 9.563–11.792) p < .001) and non-significant mean differences ranging from 1.2 to1.8. favoring KMC condition at 30, 60 and 120 seconds. Time to recovery was significantly shorter, by a minute(123 seconds (95%CI 103–142) versus 193 seconds (95%CI 158–227). Facial actions were highly significantly lower across all points in time reaching a two-fold difference by 120 seconds post-lance and heart rate was significantly lower across the first 90 seconds in the KMC condition. Conclusion Very preterm neonates appear to have endogenous mechanisms elicited through skin-to-skin maternal contact that decrease pain response, but not as

  5. [The influence of immobilized fibronectin on karyotypic variability of two rat kangaroo kidney cell lines].

    PubMed

    Polianskaia, G G; Goriachaia, T S; Pinaev, G P

    2007-01-01

    The numerical and structural karyotypic variability has been investigated in "markerless" Rat kangaroo kidney cell lines NBL-3-17 and NBL-3-11 when cultivating on a fibronectin-coated surface. In cell line NBL-3-17, cultivated on the fibronectin-coated surface for 1, 2, 4 and 8 days, the character of cell distribution for the chromosome number has changed. These changes involve a significant decrease in frequency of cells with modal number of chromosomes, and an increase in frequency of cells with lower chromosomal number. Many new additional structural variants of the karyotype (SVK) appear. The observed alterations seem to be due preference adhesion of cells with lower chromosome number, disturbances of mitotic apparatus and selection of SVK, which are more adopted to changes in culture conditions. Detachment of cells from the fibronectin-coated surface, followed by 5 days cultivation on a hydrophilic surface restored control distribution. In cell line NBL-3-11, cultivated on the fibronectin-coated surface for 1, 2, 4 and 8 days, the character of numerical karyotypic variability did not change compared to control variants. In cell line NBL-3-17 the frequency of chromosomal aberrations under cultivation on the fibronectin-coated surface for 1, 2, 4 and 8 days did not change relative to control variants. In cell line NBL-3-11 the frequency of chromosomal aberrations under the same conditions significantly increases, mainly at the expence of chromosomal, chromatid breaks and dicentrics (telomeric association) relative to control variants. We discuss possible reasons of differences in the character of numerical and structural karyotypic variability between cell lines NBL-3-17 (hypotriploid) and NBL-3-11 (hypodiploid) under cultivation on fibronectin. The reasons of the observed interline karyotypic differences possibly consist in peculiarity of karyotypic structure of cell line NBL-3-11 and in the change of gene expression, namely in a dose of certain functioning

  6. [Effect of laminin on numerical karyotype variability of kangaroo rat kidney cell lines].

    PubMed

    Polianskaia, G G; Goriachaia, T S; Mikhaĭlova, N A; Pinaev, G P

    2003-01-01

    The numerical karyotypic variability has been investigated in "markerless" epithelial-like Rat kangaroo kidney cell lines NBL-3-11 and NBL-3-17 on cultivation on a laminin-2/4 coated surface. In cell line NBL-3-17, cultivated on the laminin-coated surface for 2, 4 and 12 days, the character of numerical karyotypic variability has changed. In 2 days the general character of cell distribution for the chromosome number did not change, but the frequency of cells with modal number of chromosomes decreases significantly, while that of cells with lower chromosome number show a tendency to increase. At a prolongation of cultivation time to 4 and 12 days, the numerical karyotypic heterogeneity in cell population increases due to a significant change in the general character of cell distribution for the chromosome number, which is caused by a significant decrease in the frequency of cells with the modal number of chromosomes, and by an increase in the frequency of cells with lower chromosome number. The analysis of distribution of individual chromosomes showed that the number of types of additional structural variants of the karyotype (SVK) increases significantly on cultivation on laminin for 2-12 days. In cell line NBL-3-11, cultivated on the laminin-coated surface for 2 and 4 days, the character of numerical karyotypic variability did not change compared to control variants. Possible reasons of the observed changes of numerical karyotypic variability in cell line NBL-3-17 is discussed. The reason of differences in the character of numerical karyotypic variability between cell lines NBL-3-11 and NBL-3-17 possibly consists in the change of gene expression, namely in a dose of certain functioning genes. The polymerase chain reaction with arbitrary primers revealed no differences between DNA patterns of cell lines NBL-3-17 and NBL-3-11. This can reflect a similarity in the primary DNA structure of both cell lines. Hence, these lines differ only in the number of homologous

  7. Marsupial and monotreme serum immunoglobulin binding by proteins A, G and L and anti-kangaroo antibody.

    PubMed

    Vaz, Paola K; Hartley, Carol A; Browning, Glenn F; Devlin, Joanne M

    2015-12-01

    Serological studies are often conducted to examine exposure to infectious agents in wildlife populations. However, specific immunological reagents for wildlife species are seldom available and can limit the study of infectious diseases in these animals. This study examined the ability of four commercially available immunoglobulin-binding reagents to bind serum immunoglobulins from 17 species within the Marsupialia and Monotremata. Serum samples were assessed for binding, using immunoblots and ELISAs (Enzyme-linked immunosorbent assays), to three microbially-derived proteins - staphylococcal protein A, streptococcal protein G and peptostreptococcal protein L. Additionally, an anti-kangaroo antibody was included for comparison. The inter- and intra-familial binding patterns of the reagents to serum immunoglobulins varied and evolutionary distance between animal species was not an accurate predictor of the ability of reagents to bind immunoglobulins. Results from this study can be used to inform the selection of appropriate immunological reagents in future serological studies in these clades.

  8. Kangaroo care on premature infant growth and maternal attachment and post-partum depression in South Korea.

    PubMed

    Ahn, Hye Young; Lee, Joohyun; Shin, Hwa-Jin

    2010-10-01

    After births, premature infants need a high level of medical treatments for their survivals in the neonatal intensive care unit (NICU). This separation deprives mothers of the chance to initiate an attachment process. Kangaroo care (KC) can be one of the ways to reunite mothers and their infants in the NICU and improve health outcomes. This study was conducted to investigate the effects of KC on both premature infants and their mothers. Ten sessions of 60-min KC for 3 weeks were practiced at a level III NICU at E university hospital. Infants' body weight, height and head circumference (HC), maternal attachment and depression were measured. As a result, premature infants in KC showed higher in their height and bigger in their HC than infants in control. Maternal attachment scores were higher among the KC mothers. The results supported the beneficial effects of KC on Korean premature infants and their mothers.

  9. Distribution of the endangered giant kangaroo rat, Dipodomys ingens, on the Naval Petroleum Reserves, Kern County, California

    SciTech Connect

    O'Farrell, T.P.; Mathews, N.E.; Kato, T.T.; McCue, P.M.; McManus, J.S.; Sauls, M.L.

    1987-07-01

    Field surveys were conducted to determine the distribution and relative abundance of burrow systems of the endangered giant kangaroo rat, Dipodomys ingens, on the US Department of Energy's Naval Petroleum Reserves (NPR-1, NPR-2) in Kern County, California. A total of 1080 burrow systems were observed on 30 sections of NPR-1, 22 sections of NPR-2, and six adjoining sections. Most burrow systems were found in clusters on deep sandy loams in Buena Vista Valley, but isolated burrows were found in similar soils on the upper slopes or crests of ridges in 30 other sections of the reserves. Burrow systems had an average of 3.3 horizontal entrances measuring 2.7 in. high and 3.4 in. wide, and an average of 1.4 vertical entrances 2.0 in. in diameter. In the valleys burrows occurred in a density of 28.2 per acre; had an average slope angle of 4.3/sup 0/; were within 3.3 yd of a perennial shrub, usually a cheese-bush, Hymenoclea salsola; had a predominantly southern aspect; and were grazed by sheep, but were remote from petroleum production activities. In the uplands burrows occurred in a density of 0.1 per acre; had an average slope angle of 6.4/sup 0/; were within 5.1 yd of a perennial shrub, usually a desert saltbush, Atriplex polycarpa; had no particular aspect; and were not grazed by sheep, but were close to petroleum production activities. Since 1980, preconstruction surveys have helped conserve giant kangaroo rat burrows that may have been inadvertently threatened by construction projects on the reserves.

  10. Characterization of expressed class II MHC sequences in the banner-tailed kangaroo rat (Dipodomys spectabilis) reveals multiple DRB loci.

    PubMed

    Busch, Joseph D; Waser, Peter M; DeWoody, J Andrew

    2008-11-01

    Genes of the major histocompatibility complex (MHC) are exceptionally polymorphic due to the combined effects of natural and sexual selection. Most research in wild populations has focused on the second exon of a single class II locus (DRB), but complete gene sequences can provide an illuminating backdrop for studies of intragenic selection, recombination, and organization. To this end, we characterized class II loci in the banner-tailed kangaroo rat (Dipodomys spectabilis). Seven DRB-like sequences (provisionally named MhcDisp-DRB*01 through *07) were isolated from spleen cDNA and most likely comprise > or =5 loci; this multiformity is quite unlike the situation in muroid rodents such as Mus, Rattus, and Peromyscus. In silico translation revealed the presence of important structural residues for glycosylation sites, salt bonds, and CD4+ T-cell recognition. Amino-acid distances varied widely among the seven sequences (2-34%). Nuclear DNA sequences from the Disp-DRB*07 locus (approximately 10 kb) revealed a conventional exon/intron structure as well as a number of microsatellites and short interspersed nuclear elements (B4, Alu, and IDL-Geo subfamilies). Rates of nucleotide substitution at Disp-DRB*07 are similar in both exons and introns (pi = 0.015 and 0.012, respectively), which suggests relaxed selection and may indicate that this locus is an expressed pseudogene. Finally, we performed BLASTn searches against Dipodomys ordii genomic sequences (unassembled reads) and find 90-97% nucleotide similarity between the two kangaroo rat species. Collectively, these data suggest that class II diversity in heteromyid rodents is based on polylocism and departs from the muroid architecture.

  11. Recent demographic bottlenecks are not accompanied by a genetic signature in banner-tailed kangaroo rats (Dipodomys spectabilis).

    PubMed

    Busch, Joseph D; Waser, Peter M; Dewoody, J Andrew

    2007-06-01

    Single-sample methods of bottleneck detection are now routine analyses in studies of wild populations and conservation genetics. Three common approaches to bottleneck detection are the heterozygosity excess, mode-shift, and M-ratio tests. Empirical groundtruthing of these methods is difficult, but their performances are critical for the accurate reconstruction of population demography. We use two banner-tailed kangaroo rat (Dipodomys spectabilis) populations from southeastern Arizona (USA) that are known to have experienced recent demographic reductions to search for genetic bottleneck signals with eight microsatellite loci. Over eight total sample-years, neither population showed a genetic bottleneck signature. M-ratios in both populations were large, stable, and never fell below a critical significance value (Mc). The mode shift test did not detect any distortion of allele frequencies, and tests of heterozygosity excess were not significant in postbottleneck samples when we used standard microsatellite mutation models. The genetic effects of bottlenecks like those experienced by our study populations should be strongly influenced by rates of mutation and migration. We used genetic parentage data to estimate a relatively high mutation rate in D. spectabilis (0.0081 mutants/generation/locus), but mutation alone is unlikely to explain the temporal distribution of rare alleles that we observed. Migration (gene flow) is a more likely explanation, despite prior mark-recapture analysis that estimated very low rates of interpopulation dispersal. We interpret our kangaroo rat data in light of the broader literature and conclude that in natural populations connected by dispersal, demographic bottlenecks may prove difficult to detect using molecular genetic data.

  12. Chemical characterization of acidic oligosaccharides in milk of the red kangaroo (Macropus rufus).

    PubMed

    Anraku, Tatsuro; Fukuda, Kenji; Saito, Tadao; Messer, Michael; Urashima, Tadasu

    2012-04-01

    In the milk of marsupials, oligosaccharides usually predominate over lactose during early to mid lactation. Studies have shown that tammar wallaby milk contains a major series of neutral galactosyllactose oligosaccharides ranging in size from tri- to at least octasaccharides, as well as β(1-6) linked N-acetylglucosamine-containing oligosaccharides as a minor series. In this study, acidic oligosaccharides were purified from red kangaroo milk and characterized by (1)H-nuclear magnetic resonance spectrometry and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, to be as follows: Neu5Ac(α2-3)Gal(β1-4)Glc (3'-SL), Neu5Ac(α2-3)Gal(β1-3)Gal(β1-4)Glc (sialyl 3'-galactosyllactose), Neu5Ac(α2-3)Gal(β1-3)Gal(β1-3)Gal(β1-4)Glc, Neu5Ac(α2-3)Gal(β1-3)Gal(β1-3)Gal(β1-3)Gal(β1-4)Glc, Neu5Ac(α2-3)Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (sialyl lacto-N-novopentaose a), Gal(β1-3)[Neu5Ac(α2-6)Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (sialyl lacto-N-novopentaose b), Neu5Ac(α2-3)Gal(β1-3)Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc, Gal(β1-3)(-3-O-sulfate)Gal(β1-3)Gal(β1-4)Glc, Gal(β1-3)(-3-O-sulfate)Gal(β1-3)Gal(β1-3)Gal(β1-4)Glc, Gal(β1-3)(-3-O-sulfate)Gal(β1-3)Gal(β1-3)Gal(β1-3)Gal(β1-4)Glc, Gal(β1-3)(-3-O-sulfate)Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc, Gal(β1-3)(-3-O-sulfate)Gal(β1-3)Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc. These acidic oligosaccharides were shown to be sialylated or sulfated in the non-reducing ends to the major linear and the minor branched series of neutral oligosaccharides of tammar wallaby milk.

  13. Microstructural and compositional features of the fibrous and hyaline cartilage on the medial tibial plateau imply a unique role for the hopping locomotion of kangaroo.

    PubMed

    He, Bo; Wu, Jian Ping; Xu, Jiake; Day, Robert E; Kirk, Thomas Brett

    2013-01-01

    Hopping provides efficient and energy saving locomotion for kangaroos, but it results in great forces in the knee joints. A previous study has suggested that a unique fibrous cartilage in the central region of the tibial cartilage could serve to decrease the peak stresses generated within kangaroo tibiofemoral joints. However, the influences of the microstructure, composition and mechanical properties of the central fibrous and peripheral hyaline cartilage on the function of the knee joints are still to be defined. The present study showed that the fibrous cartilage was thicker and had a lower chondrocyte density than the hyaline cartilage. Despite having a higher PG content in the middle and deep zones, the fibrous cartilage had an inferior compressive strength compared to the peripheral hyaline cartilage. The fibrous cartilage had a complex three dimensional collagen meshwork with collagen bundles parallel to the surface in the superficial zone, and with collagen bundles both parallel and perpendicular to the surface in the middle and deep zones. The collagen in the hyaline cartilage displayed a typical Benninghoff structure, with collagen fibres parallel to the surface in the superficial zone and collagen fibres perpendicular to the surface in the deep zone. Elastin fibres were found throughout the entire tissue depth of the fibrous cartilage and displayed a similar alignment to the adjacent collagen bundles. In comparison, the elastin fibres in the hyaline cartilage were confined within the superficial zone. This study examined for the first time the fibrillary structure, PG content and compressive properties of the central fibrous cartilage pad and peripheral hyaline cartilage within the kangaroo medial tibial plateau. It provided insights into the microstructure and composition of the fibrous and peripheral hyaline cartilage in relation to the unique mechanical properties of the tissues to provide for the normal activities of kangaroos.

  14. Genetic microsurgery by laser: establishment of a clonal population of rat kangaroo cells (PTK2) with a directed deficiency in a chromosomal nucleolar organizer.

    PubMed

    Berns, M W; Chong, L K; Hammer-Wilson, M; Miller, K; Siemens, A

    1979-06-21

    An ultraviolet laser beam was focused to a submicron spot on one of the nucleolar organizer regions of mitotic chromosomes of rat kangaroo cells in tissue culture. The daughter cells were isolated and cloned into a viable population that maintained the directed nucleolar deficiency. It is concluded that the laser can be used to delete preselected genetic regions and the genetic deletion is maintained as a heritable deficiency in subsequent daughter cells.

  15. Minimum daily core body temperature in western grey kangaroos decreases as summer advances: a seasonal pattern, or a direct response to water, heat or energy supply?

    PubMed

    Maloney, Shane K; Fuller, Andrea; Meyer, Leith C R; Kamerman, Peter R; Mitchell, Graham; Mitchell, Duncan

    2011-06-01

    Using implanted temperature loggers, we measured core body temperature in nine western grey kangaroos every 5 min for 24 to 98 days in spring and summer. Body temperature was highest at night and decreased rapidly early in the morning, reaching a nadir at 10:00 h, after ambient temperature and solar radiation had begun to increase. On hotter days, the minimum morning body temperature was lower than on cooler days, decreasing from a mean of 36.2°C in the spring to 34.0°C in the summer. This effect correlated better with the time of the year than with proximate thermal stressors, suggesting that either season itself or some factor correlated with season, such as food availability, caused the change. Water saving has been proposed as a selective advantage of heterothermy in other large mammals, but in kangaroos the water savings would have been small and not required in a reserve with permanent standing water. We calculate that the lower core temperature could provide energy savings of nearly 7%. It is likely that the heterothermy that we observed on hot days results either from decreased energy intake during the dry season or from a seasonal pattern entrained in the kangaroos that presumably has been selected for because of decreased energy availability during the dry season.

  16. Phylogeography of the pallid kangaroo mouse, Microdipodops pallidus: a sand-obligate endemic of the Great Basin, western North America

    PubMed Central

    Hafner, John C; Upham, Nathan S; Reddington, Emily; Torres, Candice W

    2008-01-01

    Aim Kangaroo mice, genus Microdipodops Merriam, are endemic to the Great Basin and include two species: M. pallidus Merriam and M. megacephalus Merriam. The pallid kangaroo mouse, M. pallidus, is a sand-obligate desert rodent. Our principal intent is to identify its current geographical distribution and to formulate a phylogeographical hypothesis for this taxon. In addition, we test for orientation patterns in haplotype sharing for evidence of past episodes of movement and gene flow. Location The Great Basin Desert region of western North America, especially the sandy habitats of the Lahontan Trough and those in south-central Nevada. Methods Mitochondrial DNA sequence data from portions of three genes (16S ribosomal RNA, cytochrome b, and transfer RNA for glutamic acid) were obtained from 98 individuals of M. pallidus representing 27 general localities sampled throughout its geographical range. Molecular sequence data were analysed using neighbour-joining, maximum-parsimony, maximum-likelihood and Bayesian methods of phylogenetic inference. Directional analysis of phylogeographical patterns, a novel method, was used to examine angular measurements of haplotype sharing between pairs of localities to detect and quantify historical events pertaining to movement patterns and gene flow. Results Collecting activities showed that M. pallidus is a rather rare rodent (mean trapping success was 2.88%), and its distribution has changed little from that determined three-quarters of a century ago. Two principal phylogroups, distributed as eastern and western moieties, are evident from the phylogenetic analyses (mean sequence divergence for cytochrome b is c. 8%). The western clade shows little phylogenetic structure and seems to represent a large polytomy. In the eastern clade, however, three subgroups are recognized. Nine of the 42 unique composite haplotypes are present at two or more localities and are used for the orientation analyses. Axial data from haplotype sharing

  17. Boundary-layer turbulence modeling and vorticity dynamics: I. A kangaroo-process mixing model of boundary-layer turbulence

    NASA Astrophysics Data System (ADS)

    Dekker, H.; de Leeuw, G.; van den Brink, A. Maassen

    A nonlocal turbulence transport theory is presented by means of a novel analysis of the Reynolds stress, inter alia involving the construct of a sample path space and a stochastic hypothesis. An analytical sampling rate model (satisfying exchange) and a nonlinear scaling relation (mapping the path space onto the boundary layer) lead to an integro-differential equation for the mixing of scalar densities, which represents fully-developed boundary-layer turbulence as a nondiffusive (Kubo-Anderson or kangaroo) type stochastic process. The underlying near-wall behavior (i.e. for y +→0) of fluctuating velocities fully agrees with recent direct numerical simulations. The model involves a scaling exponent ɛ, with ɛ→∞ in the diffusion limit. For the (partly analytical) solution for the mean velocity profile, excellent agreement with the experimental data yields ɛ≈0.58. The significance of ɛ as a turbulence Cantor set dimension (in the logarithmic profile region, i.e. for y +→∞) is discussed.

  18. A new species of the basal "kangaroo" Balbaroo and a re-evaluation of stem macropodiform interrelationships.

    PubMed

    Black, Karen H; Travouillon, Kenny J; Den Boer, Wendy; Kear, Benjamin P; Cooke, Bernard N; Archer, Michael

    2014-01-01

    Exceptionally well-preserved skulls and postcranial elements of a new species of the plesiomorphic stem macropodiform Balbaroo have been recovered from middle Miocene freshwater limestone deposits in the Riversleigh World Heritage Area of northwestern Queensland, Australia. This constitutes the richest intraspecific sample for any currently known basal "kangaroo", and, along with additional material referred to Balbaroo fangaroo, provides new insights into structural variability within the most prolific archaic macropodiform clade--Balbaridae. Qualitative and metric evaluations of taxonomic boundaries demonstrate that the previously distinct species Nambaroo bullockensis is a junior synonym of B. camfieldensis. Furthermore, coupled Maximum Parsimony and Bayesian phylogenetic analyses reveal that our new Balbaroo remains represent the most derived member of the Balbaroo lineage, and are closely related to the middle Miocene B. camfieldensis, which like most named balbarid species is identifiable only from isolated jaws. The postcranial elements of Balbaroo concur with earlier finds of the stratigraphically oldest balbarid skeleton, Nambaroo gillespieae, and suggest that quadrupedal progression was a primary gait mode as opposed to bipedal saltation. All Balbaroo spp. have low-crowned bilophodont molars, which are typical for browsing herbivores inhabiting the densely forested environments envisaged for middle Miocene northeastern Australia.

  19. Kangaroo care and behavioral and physiologic pain responses in very-low-birth-weight twins: a case study.

    PubMed

    Cong, Xiaomei; Cusson, Regina M; Hussain, Naveed; Zhang, Di; Kelly, Sharon P

    2012-09-01

    The purpose of this case study was to describe pain responses in three study conditions: longer (30 minutes) kangaroo care (KC) before and throughout heel stick (KC30), shorter (15 minutes) KC before and throughout heel stick (KC15), and incubator care throughout heel stick (IC) in 28-week gestational age twins. Pain responses were measured by crying time, Preterm Infant Pain Profile (PIPP), and heart rate variability indexes, including low-frequency power (LF, representing sympathetic activity), high-frequency power (HF, parasympathetic activity), and LF/HF ratio (sympathetic-parasympathetic balance). Both twins cried more and had higher PIPP pain scores and tachycardia during heel stick in the IC condition. Infant B had an incident of apnea and tachycardia by the end of the heel stick and a bradycardia episode during recovery in the IC condition. The twins had lower LF/HF ratios (better autonomic nervous system balance) during recovery in both longer and shorter KC conditions compared with the IC condition. Infant B had difficulty returning to LF/HF ratio baseline level after the painful procedure in the IC condition. These data suggest that both longer and shorter KC before and throughout painful procedures can be helpful in reducing behavioral and physiologic pain responses in preterm infants.

  20. The Effects of Kangaroo Mother Care and Swaddling on Venipuncture Pain in Premature Neonates: A Randomized Clinical Trial

    PubMed Central

    Dezhdar, Shahin; Jahanpour, Faezeh; Firouz Bakht, Saeedeh; Ostovar, Afshin

    2016-01-01

    Background Hospitalized premature babies often undergo various painful procedures. Kangaroo mother care (KMC) and swaddling are two pain reduction methods. Objectives This study was undertaken to compare the effects of swaddling and KMC on pain during venous sampling in premature neonates. Patients and Methods This study was performed as a randomized clinical trial on 90 premature neonates. The neonates were divided into three groups using a random allocation block. The three groups were group A (swaddling), group B (KMC), and group C (control). In all three groups, the heart rate and arterial oxygen saturation were measured and recorded in time intervals of 30 seconds before, during, and 30, 60, 90, and 120 seconds after blood sampling. The neonate’s face was video recorded and assessed using the premature infant pain profile (PIPP) at time intervals of 30 seconds. The data was analyzed using the t-test, chi-square test, Repeated Measure analysis of variance (ANOVA), Kruskal-Wallis, Post-hoc, and Bonferroni test. Results The findings revealed that pain was reduced to a great extent in the swaddling and KMC methods compared to the control group. However, there was no significant difference between KMC and swaddling (P ≥ 0.05). Conclusions The results of this study indicate that there is no meaningful difference between swaddling and KMC on physiological indexes and pain in neonates. Therefore, the swaddling method may be a good substitute for KMC. PMID:27274399

  1. The Newborn Individualized Developmental Care and Assessment Program (NIDCAP) with Kangaroo Mother Care (KMC): Comprehensive Care for Preterm Infants

    PubMed Central

    Als, Heidelise; McAnulty, Gloria B.

    2014-01-01

    State-of-the-art Newborn Intensive Care Units (NICUs), instrumental in the survival of high-risk and ever-earlier-born preterm infants, often have costly human repercussions. The developmental sequelae of newborn intensive care are largely misunderstood. Developed countries eager to export their technologies must also transfer the knowledge-base that encompasses all high-risk and preterm infants’ personhood as well as the neuro-essential importance of their parents. Without such understanding, the best medical care, while assuring survival jeopardizes infants’ long-term potential and deprives parents of their critical role. Exchanging the womb for the NICU environment at a time of rapid brain growth compromises preterm infants’ early development, which results in long-term physical and mental health problems and developmental disabilities. The Newborn Individualized Developmental Care and Assessment Program (NIDCAP) aims to prevent the iatrogenic sequelae of intensive care and to maintain the intimate connection between parent and infant, one expression of which is Kangaroo Mother Care. NIDCAP embeds the infant in the natural parent niche, avoids over-stimulation, stress, pain, and isolation while it supports self-regulation, competence, and goal orientation. Research demonstrates that NIDCAP improves brain development, functional competence, health, and life quality. It is cost effective, humane, and ethical, and promises to become the standard for all NICU care. PMID:25473384

  2. The intermediate-sized filaments in rat kangaroo PtK2 cells. II. Structure and composition of isolated filaments.

    PubMed

    Franke, W W; Schmid, E; Osborn, M; Weber, K

    1978-08-01

    When cultured cells of the rat kangaroo cell line PtK2 grown on plastic or glass surfaces are lysed and extracted with combinations of low and high salt buffers and the non-ionic detergent Triton X-100 cytoskeletal preparations are obtained that show an enrichment of 6 to 11 nm thick filaments. The arrays of these filaments have been examined by various light and electron microscopic techniques, including ultrathin sectioning, whole mount transmission electron microscopy, negative staining, and indirect immunofluorescence microscopy. In addition, 6 to 11 nm filaments isolated from these cells with similar extraction procedures and with centrifugation techniques have been examined by electron microscopy. The arrays of these isolated intermediate-sized filaments, their ultrastructure and their specific decoration by certain antibodies present in normal rabbit sera as well as by guinea pig antibodies against purified bovine prekeratin is demonstrated. When preparations enriched in these intermediate-sized filaments are examined by SDS-polyacrylamide gel electrophoresis a corresponding enrichment of three polypeptide bands with apparent molecular weights of about 45 000, 52 000 and 58 000 (the latter component sometimes appears split into two bands) is observed, besides some residual actin and a few high molecular weight bands. The morphology of the isolated filaments, their immunological reaction with antibodies decorating prekeratin-containing structures, and the sizes of their constitutive polypeptides suggest that these filaments are closely related to prekeratin-containing filaments observed in a variety of epithelial cells.

  3. Maternal presence and rearing condition affect responses to a live predator in kangaroo rats (Dipodomys heermanni arenae).

    PubMed

    Yoerg, S I; Shier, D M

    1997-12-01

    Experiment 1 compared the responses of wild-caught adult and captive-born adult and juvenile kangaroo rats (Dipodomys heermanni arenae) to a live snake. Wild-caught adult rats were less active and monitored the snake more than during a control condition; captive-born juvenile rats did not behave differently during snake and control tests. Snake-naive adult rats behaved more like the wild-caught adult rats, but not on all measures. In Experiment 2, pups were tested at 25 and 50 days of age in 4 conditions: no-snake control, alone with the snake, with a sibling and the snake, and with the mother and the snake. Pups did not behave differently during control and snake tests, but during tests with the mother, pups faced the snake less and followed the mother. Younger pups were more often near the mother than a sibling and followed the mother more when the snake was present. Development of defensive behavior may depend on both predator experience and maternal influence.

  4. Unique features of spermiogenesis in the Musky Rat-kangaroo: reflection of a basal lineage or a distinct fertilization process?

    PubMed

    Lloyd, Shan; Carrick, Frank; Hall, Les

    2008-03-01

    Previous research has found the mature spermatozoon of the Musky Rat-kangaroo to share many characteristics with other macopodoids, some phalangeroids and even the dasyurids. While there have been several studies published on the ultrastructure of the mature marsupial spermatozoon, there are only a few detailed studies on marsupial spermatogenesis. Furthermore, there have been no studies undertaken which combine the staging of the epithelial cell cycle with transmission electron microscopy to describe the ultrastructural changes in the developing spermatozoon during these stages. Such studies have the potential to be used in determining the required time taken for certain components of the spermatozoa to develop. During this study, eight stages of the seminiferous epithelium were observed and the ultrastructure of spermatogenesis was divided into nine phases. Maturational processes in the epididymides are also described. Among the features reported are: the formation of a unique acrosomal granule different from those reported in any other marsupial, the absence of contraction of the nuclear ring, a conspicuous acrosomal compaction process despite the almost 100% coverage of the dorsal nuclear surface and the retention of late spermatids within the seminiferous tubules until the early spermatids have developed to the nuclear protrusion phase.

  5. Hosts of the exotic ornate kangaroo tick, Amblyomma triguttatum triguttatum Koch, on southern Yorke Peninsula, South Australia.

    PubMed

    Waudby, Helen P; Petit, Sophie; Dixon, Bruce; Andrews, Ross H

    2007-10-01

    Amblyomma triguttatum triguttatum is assumed to be endemic to south-western Western Australia (including Barrow Island), Queensland (excluding Cape York Peninsula), and New South Wales, south to Dubbo and Barham. The species has been recorded on a range of mammalian hosts including macropods and domestic animals. In Queensland, A. triguttatum triguttatum is implicated in the epidemiology of Q fever. In 2000, the species was detected on southern Yorke Peninsula in South Australia. We aimed to identify A. triguttatum triguttatum's hosts through trapping, sampling of carcasses, and opportunistic capture of vertebrates on Yorke Peninsula. A. triguttatum triguttatum was removed from black rats (Rattus rattus), wild rabbits (Oryctolagus cuniculus), western grey kangaroos (Macropus fuliginosus), Tammar wallabies (M. eugenii eugenii), domesticated cats and dogs, and humans. Before this study, A. triguttatum triguttatum had not been found on black rats or rabbits in the wild. This research has implications for the management of wildlife, livestock, and visitors on Yorke Peninsula. The potential for A. triguttatum triguttatum to spread to other areas of Yorke Peninsula and South Australia is considerable, as visitors (tourists) to southern Yorke Peninsula report the presence of ticks both on themselves and among camping equipment on arriving home.

  6. Infection with Toxoplasma gondii in a red kangaroo (Macropus rufus) and a Patagonian mara (Dolichotis patagonum) in captivity.

    PubMed

    Díaz-Ayala, Nataly; Hidalgo-Hermoso, Ezequiel; Cabello-Araya, Constanza; Carvallo-Chaigneau, Francisco

    2016-01-01

    Toxoplasmosis is an infectious, zoonotic and parasitic disease, caused by Toxoplasma gondii. In this manucript, two cases of infection with T. gondii in captive animals from a zoological park in the central region of Chile are described. One case was a red kangaroo (Macropus rufus), which is highly susceptible to the infection, and the other was a Patagonian mara (Dolichotis patagonum), a rodent in which there is no previous report of the infection. Both animals had myocarditis, with the presence of intralesional tachizoites and cysts suggestive of infection with T. gondii. This infection was confirmed by immunohistochemistry in both animals. The origin of the infection is unknown, but it is likely that free ranging domestic felines were associated with the dissemination of the parasites. This highlights the importance of controlling the domestic animal populations in zoological parks. To the best of our knowledge, this is the first time that T. gondii infection is described in a Patagonian mara, adding a new host for this infectious agent.

  7. Secretion of whey acidic protein and cystatin is down regulated at mid-lactation in the red kangaroo (Macropus rufus)

    USGS Publications Warehouse

    Nicholas, K.R.; Fisher, J.A.; Muths, E.; Trott, J.; Janssens, P.A.; Reich, C.; Shaw, D.C.

    2001-01-01

    Milk collected from the red kangaroo (Macropus rufus) between day 100 and 260 of lactation showed major changes in milk composition at around day 200 of lactation, the time at which the pouch young begins to temporarily exit the pouch and eat herbage. The carbohydrate content of milk declined abruptly at this time and although there was only a small increase in total protein content, SDS PAGE analysis of milk revealed asynchrony in the secretory pattern of individual proteins. The levels of ??-lactalbumin, ??-lactoglobulin, serum albumin and transferrin remain unchanged during lactation. In contrast, the protease inhibitor cystatin, and the putative protease inhibitor whey acidic protein (WAP) first appeared in milk at elevated concentrations after approximately 150 days of lactation and then ceased to be secreted at approximately 200 days. In addition, a major whey protein, late lactation protein, was first detected in milk around the time whey acidic protein and cystatin cease to be secreted and was present at least until day 260 of lactation. The co-ordinated, but asynchronous secretion of putative protease inhibitors in milk may have several roles during lactation including tissue remodelling in the mammary gland and protecting specific proteins in milk required for physiological development of the dependent young. ?? 2001 Elsevier Science Inc.

  8. Glyphosate persistence in seawater.

    PubMed

    Mercurio, Philip; Flores, Florita; Mueller, Jochen F; Carter, Steve; Negri, Andrew P

    2014-08-30

    Glyphosate is one of the most widely applied herbicides globally but its persistence in seawater has not been reported. Here we quantify the biodegradation of glyphosate using standard "simulation" flask tests with native bacterial populations and coastal seawater from the Great Barrier Reef. The half-life for glyphosate at 25 °C in low-light was 47 days, extending to 267 days in the dark at 25 °C and 315 days in the dark at 31 °C, which is the longest persistence reported for this herbicide. AMPA, the microbial transformation product of glyphosate, was detected under all conditions, confirming that degradation was mediated by the native microbial community. This study demonstrates glyphosate is moderately persistent in the marine water under low light conditions and is highly persistent in the dark. Little degradation would be expected during flood plumes in the tropics, which could potentially deliver dissolved and sediment-bound glyphosate far from shore.

  9. Persistent heap Management library

    SciTech Connect

    2012-01-17

    PERM is a C library for persistent heap management and is intended for use with a dynamic-memory allocator (e.g. malloc, free). The PERM memory allocator replaces the standard C dynamic memory allocation functions with compatible versions that provide persistent memory to application programs. Memory allocated with the PERM allocatory will persist between program invocations after a call to a checkpoint function. This function essentially saves the state of the heap and registered global variables to a file which may reside in flash memory or other node local storage. A few other functions are also provided by the library to manage checkpoint files. Global variables in an application can be marked persistent and be included in a checkpoint by using a compiler attribute defined as PERM. The PERM checkpoint methof is not dependent on the programming model ans works with distributed memory or shared memory programs.

  10. Persistent depressive disorder

    MedlinePlus

    ... But, symptoms are not as severe as with major depression . Persistent depressive disorder used to be called dysthymia. ... with PDD will also have an episode of major depression at some point in their lives. Older people ...

  11. The high aerobic capacity of a small, marsupial rat-kangaroo (Bettongia penicillata) is matched by the mitochondrial and capillary morphology of its skeletal muscles.

    PubMed

    Webster, Koa N; Dawson, Terence J

    2012-09-15

    We examined the structure-function relationships that underlie the aerobic capacities of marsupial mammals that hop. Marsupials have relatively low basal metabolic rates (BMR) and historically were seen as 'low energy' mammals. However, the red kangaroo, Macropus rufus (family Macropodidae), has aerobic capacities equivalent to athletic placentals. It has an extreme aerobic scope (fAS) and its large locomotor muscles feature high mitochondrial and capillary volumes. M. rufus belongs to a modern group of kangaroos and its high fAS is not general for marsupials. However, other hopping marsupials may have elevated aerobic capacities. Bettongia penicillata, a rat-kangaroo (family Potoroidae), is a small (1 kg), active hopper whose fAS is somewhat elevated. We examined the oxygen delivery system in its muscles to ascertain links with hopping. An elevated fAS of 23 provided a relatively high maximal aerobic oxygen consumption ( ) in B. penicillata; associated with this is a skeletal muscle mass of 44% of body mass. Ten muscles were sampled to estimate the total mitochondrial and capillary volume of the locomotor muscles. Values in B. penicillata were similar to those in M. rufus and in athletic placentals. This small hopper had high muscle mitochondrial volume densities (7.1-11.9%) and both a large total capillary volume (6 ml kg(-1) body mass) and total capillary erythrocyte volume (3.2 ml kg(-1)). Apparently, a considerable aerobic capacity is required to achieve the benefits of the extended stride in fast hopping. Of note, the ratio of to total muscle mitochondrial volume in B. penicillata was 4.9 ml O(2) min(-1) ml(-1). Similar values occur in M. rufus and also placental mammals generally, not only athletic species. If such relationships occur in other marsupials, a fundamental structure-function relationship for oxygen delivery to muscles likely originated with or before the earliest mammals.

  12. 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

  13. Elevated surface temperature depresses survival of banner-tailed kangaroo rats: will climate change cook a desert icon?

    PubMed

    Moses, Martin R; Frey, Jennifer K; Roemer, Gary W

    2012-01-01

    Modest increases in global temperature have been implicated in causing population extirpations and range shifts in taxa inhabiting colder environs and in ectotherms whose thermoregulation is more closely tied to environmental conditions. Many arid-adapted endotherms already experience conditions at their physiological limits, so it is conceivable that they could be similarly affected by warming temperatures. We explored how climatic variables might influence the apparent survival of the banner-tailed kangaroo rat (Dipodomys spectabilis), a rodent endemic to the Chihuahuan Desert of North America and renowned for its behavioral and physiological adaptations to arid environments. Relative variable weight, strength of variable relationships, and other criteria indicated that summer, diurnal land surface temperature (SD_LST) was the primary environmental driver of apparent survival in these arid-adapted rodents. Higher temperatures had a negative effect on apparent survival, which ranged from 0.15 (SE = 0.04) for subadults to 0.50 (SE = 0.07) for adults. Elevated SD_LST may negatively influence survival through multiple pathways, including increased water loss and energy expenditure that could lead to chronic stress and/or hyperthermia that could cause direct mortality. Land surface temperatures are predicted to increase by as much 6.5°C by 2099, reducing apparent survival of adults to ~0.15 in some regions of the species' range, possibly causing a shift in their distribution. The relationship between SD_LST and survival suggests a mechanism whereby physiological tolerances are exceeded resulting in a reduction to individual fitness that may ultimately cause a shift in the species' range over time.

  14. A sedge plant as the source of Kangaroo Island propolis rich in prenylated p-coumarate ester and stilbenes.

    PubMed

    Duke, Colin C; Tran, Van H; Duke, Rujee K; Abu-Mellal, Abdallah; Plunkett, George T; King, Douglas I; Hamid, Kaiser; Wilson, Karen L; Barrett, Russell L; Bruhl, Jeremy J

    2017-02-01

    Propolis samples from Kangaroo Island, South Australia, were investigated for chemical constituents using high-field nuclear magnetic resonance spectral profiling. A type of propolis was found containing a high proportion of prenylated hydroxystilbenes. Subsequently, the botanical origin of this type of propolis was identified using a beehive propolis depletion method and analysis of flora. Ligurian honey bees, Apis mellifera ligustica Spinola, were found to produce propolis from resin exuded by the Australian native sedge plant Lepidosperma sp. Montebello (Cyperaceae). The plants, commonly known as sword sedge, were found to have resin that matched with the propolis samples identified as the most abundant propolis type on the island containing C- and O-prenylated tetrahydroxystilbenes (pTHOS) in addition to a small amount of prenylated p-coumarate. The isolation of five pTHOS not previously characterized are reported: (E)-4-(3-methyl-2-buten-1-yl)-3,4',5-trihydroxy-3'-methoxystilbene, (E)-2,4-bis(3-methyl-2-buten-1-yl)-3,3',4',5-tetrahydroxystilbene, (E)-2-(3-methyl-2-buten-1-yl)-3-(3-methyl-2-butenyloxy)-3',4',5-trihydroxystilbene, (E)-2,6-bis(3-methyl-2-buten-1-yl)-3,3',5,5'-tetrahydroxystilbene and (E)-2,6-bis(3-methyl-2-buten-1-yl)-3,4',5-trihydroxy-3'-methoxystilbene. A National Cancer Institute 60 human cell line anticancer screen of three of these compounds showed growth inhibitory activity. The large Australasian genus Lepidosperma is identified as a valuable resource for the isolation of substances with medicinal potential.

  15. The intermediate-sized filaments in rat kangaroo PtK2 cells. I. Morphology in situ.

    PubMed

    Franke, W W; Grund, C; Osborn, M; Weber, K

    1978-08-01

    The system of the intermediate-sized filaments (IF) of rat kangaroo PtK2 cells which can be specifically demonstrated by immunofluorescence microscopy using certain rabbit autoantibodies and guinea pig antibodies against bovine hoof prekeratin has been studied by electron microscopy. The characteristic ornamental, curved arrays of this system are shown after fixation in situ in both thin sections and whole-cell-preparations to represent bundles of 6 to 11 nm thick filaments extending through the whole cytoplasm, although in some cells they appear to be enriched in the perinuclear region. While many individual IF are recognized in the cytoplasm the tendency of such filaments to aggregate laterally into bundles is one of their prominent features. Among such bundle formations one form that consists of tightly packed IF cemented together in a dense osmiophilic matrix is especially conspicious. The appearance and mode of arrangement of the IF is not significantly altered in cells treated with colcemid and/or cytochalasin B. Spatial relationships of IF with microfilament-containing cables and microtubules as well as with membranous structures are also described. IF are heterogeneous in width and reveal an unstained, apparently hollow core, indicative of a tubular organization. Many IF show small, sometimes periodically arranged lateral projections which seem to be involved in IF cross-linking. Associations with polyribosomes are common. The changes in the IF system during mitosis have also been examined. The structural details of the IF as well as their possible role as cytoskeletal elements involved in the control of cell shape and cytoplasmic architecture are discussed in relation to data on various intermediate-sized filaments from other cell types. The close similarity of the IF of PtK2 cells to aggregates of prekeratin filaments is emphasized. It is suggested that PtK2 cells represent an epithelial cell line growing in a state of balanced semi-keratinization.

  16. Newborn care practices in rural Bangladesh: Implications for the adaptation of kangaroo mother care for community-based interventions.

    PubMed

    Hunter, Erin C; Callaghan-Koru, Jennifer A; Al Mahmud, Abdullah; Shah, Rashed; Farzin, Azadeh; Cristofalo, Elizabeth A; Akhter, Sadika; Baqui, Abdullah H

    2014-12-01

    Bangladesh has one of the world's highest rates of low birth weight along with prevalent traditional care practices that leave newborns highly vulnerable to hypothermia, infection, and early death. We conducted formative research to explore existing newborn care practices in rural Bangladesh with an emphasis on thermal protection, and to identify potential facilitators, barriers, and recommendations for the community level delivery of kangaroo mother care (CKMC). Forty in-depth interviews and 14 focus group discussions were conducted between September and December 2012. Participants included pregnant women and mothers, husbands, maternal and paternal grandmothers, traditional birth attendants, village doctors, traditional healers, pharmacy men, religious leaders, community leaders, and formal healthcare providers. Audio recordings were transcribed and translated into English, and the textual data were analyzed using the Framework Approach. We find that harmful newborn care practices, such as delayed wrapping and early initiation of bathing, are changing as more biomedical advice from formal healthcare providers is reaching the community through word-of-mouth and television campaigns. While the goal of CKMC was relatively easily understood and accepted by many of the participants, logistical and to a lesser extent ideological barriers exist that may keep the practice from being adopted easily. Women feel a sense of inevitable responsibility for household duties despite the desire to provide the best care for their new babies. Our findings showed that participants appreciated CKMC as an appropriate treatment method for ill babies, but were less accepting of it as a protective method of caring for seemingly healthy newborns during the first few days of life. Participants highlighted the necessity of receiving help from family members and witnessing other women performing CKMC with positive outcomes if they are to adopt the behavior themselves. Focusing intervention

  17. Visual persistence and cinema?

    PubMed

    Galifret, Yves

    2006-01-01

    In Faraday and Plateau's days, both apparent motion and the fusion of intermittent lights, two phenomena that are hardly connected, were explained by retinal persistence. The works of Exner and of the 'Gestalt' psychologists, as well as the modern works on 'sampled' motion and smooth motion, disregarded retinal persistence. One tried, originally, to measure this persistence using intermittent stimulation, but under the pressure of practical concern, what was established in 1902 was the logarithmic relation between fusion frequency and the intensity of the stimulation. One had to wait until the 1950s for the use of harmonic analysis to finally allow a renewal in which many problems that, for decades, had only given rise to discussions that led nowhere and to groundless assertions, were correctly stated and easily solved.

  18. A priori and a posteriori approaches for finding genes of evolutionary interest in non-model species: osmoregulatory genes in the kidney transcriptome of the desert rodent Dipodomys spectabilis (banner-tailed kangaroo rat).

    PubMed

    Marra, Nicholas J; Eo, Soo Hyung; Hale, Matthew C; Waser, Peter M; DeWoody, J Andrew

    2012-12-01

    One common goal in evolutionary biology is the identification of genes underlying adaptive traits of evolutionary interest. Recently next-generation sequencing techniques have greatly facilitated such evolutionary studies in species otherwise depauperate of genomic resources. Kangaroo rats (Dipodomys sp.) serve as exemplars of adaptation in that they inhabit extremely arid environments, yet require no drinking water because of ultra-efficient kidney function and osmoregulation. As a basis for identifying water conservation genes in kangaroo rats, we conducted a priori bioinformatics searches in model rodents (Mus musculus and Rattus norvegicus) to identify candidate genes with known or suspected osmoregulatory function. We then obtained 446,758 reads via 454 pyrosequencing to characterize genes expressed in the kidney of banner-tailed kangaroo rats (Dipodomys spectabilis). We also determined candidates a posteriori by identifying genes that were overexpressed in the kidney. The kangaroo rat sequences revealed nine different a priori candidate genes predicted from our Mus and Rattus searches, as well as 32 a posteriori candidate genes that were overexpressed in kidney. Mutations in two of these genes, Slc12a1 and Slc12a3, cause human renal diseases that result in the inability to concentrate urine. These genes are likely key determinants of physiological water conservation in desert rodents.

  19. Reconstructing temporal variation of fluoride uptake in eastern grey kangaroos (Macropus giganteus) from a high-fluoride area by analysis of fluoride distribution in dentine.

    PubMed

    Kierdorf, Horst; Rhede, Dieter; Death, Clare; Hufschmid, Jasmin; Kierdorf, Uwe

    2016-04-01

    Trace element profiling in the incrementally formed dentine of mammalian teeth can be applied to reconstruct temporal variation of incorporation of these elements into the tissue. Using an electron microprobe, this study analysed fluoride distribution in dentine of first and third mandibular molars of free-ranging eastern grey kangaroos inhabiting a high-fluoride area, to assess temporal variation in fluoride uptake of the animals. Fluoride content in the early-formed dentine of first molars was significantly lower than in the late-formed dentine of these teeth, and was also lower than in both, the early and the late-formed dentine of third molars. As early dentine formation in M1 takes place prior to weaning, this finding indicates a lower dentinal fluoride uptake during the pre-weaning compared to the post-weaning period. This is hypothetically attributed to the action of a partial barrier to fluoride transfer from blood to milk in lactating females and a low bioavailability of fluoride ingested together with milk. Another factor contributing to lower plasma fluoride levels in juveniles compared to adults is the rapid clearance of fluoride from blood plasma in the former due to their intense skeletal growth. The combined action of these mechanisms is considered to explain why in kangaroos from high-fluoride areas, the (early-formed) first molars are not affected by dental fluorosis while the (later-formed) third and fourth molars regularly exhibit marked to severe fluorotic lesions.

  20. A retrospective study of Babesia macropus associated with morbidity and mortality in eastern grey kangaroos (Macropus giganteus) and agile wallabies (Macropus agilis)

    PubMed Central

    Donahoe, Shannon L.; Peacock, Christopher S.; Choo, Ace Y.L.; Cook, Roger W.; O'Donoghue, Peter; Crameri, Sandra; Vogelnest, Larry; Gordon, Anita N.; Scott, Jenni L.; Rose, Karrie

    2015-01-01

    This is a retrospective study of 38 cases of infection by Babesia macropus, associated with a syndrome of anaemia and debility in hand-reared or free-ranging juvenile eastern grey kangaroos (Macropus giganteus) from coastal New South Wales and south-eastern Queensland between 1995 and 2013. Infection with B. macropus is recorded for the first time in agile wallabies (Macropus agilis) from far north Queensland. Animals in which B. macropus infection was considered to be the primary cause of morbidity had marked anaemia, lethargy and neurological signs, and often died. In these cases, parasitised erythrocytes were few or undetectable in peripheral blood samples but were sequestered in large numbers within small vessels of visceral organs, particularly in the kidney and brain, associated with distinctive clusters of extraerythrocytic organisms. Initial identification of this piroplasm in peripheral blood smears and in tissue impression smears and histological sections was confirmed using transmission electron microscopy and molecular analysis. Samples of kidney, brain or blood were tested using PCR and DNA sequencing of the 18S ribosomal RNA and heat shock protein 70 gene using primers specific for piroplasms. The piroplasm detected in these samples had 100% sequence identity in the 18S rRNA region with the recently described Babesia macropus in two eastern grey kangaroos from New South Wales and Queensland, and a high degree of similarity to an unnamed Babesia sp. recently detected in three woylies (Bettongia penicillata ogilbyi) in Western Australia. PMID:26106576

  1. Thorough assessment of DNA preservation from fossil bone and sediments excavated from a late Pleistocene-Holocene cave deposit on Kangaroo Island, South Australia

    NASA Astrophysics Data System (ADS)

    Haouchar, Dalal; Haile, James; McDowell, Matthew C.; Murray, Dáithí C.; White, Nicole E.; Allcock, Richard J. N.; Phillips, Matthew J.; Prideaux, Gavin J.; Bunce, Michael

    2014-01-01

    Fossils and sediments preserved in caves are an excellent source of information for investigating impacts of past environmental changes on biodiversity. Until recently studies have relied on morphology-based palaeontological approaches, but recent advances in molecular analytical methods offer excellent potential for extracting a greater array of biological information from these sites. This study presents a thorough assessment of DNA preservation from late Pleistocene-Holocene vertebrate fossils and sediments from Kelly Hill Cave Kangaroo Island, South Australia. Using a combination of extraction techniques and sequencing technologies, ancient DNA was characterised from over 70 bones and 20 sediment samples from 15 stratigraphic layers ranging in age from >20 ka to ˜6.8 ka. A combination of primers targeting marsupial and placental mammals, reptiles and two universal plant primers were used to reveal genetic biodiversity for comparison with the mainland and with the morphological fossil record for Kelly Hill Cave. We demonstrate that Kelly Hill Cave has excellent long-term DNA preservation, back to at least 20 ka. This contrasts with the majority of Australian cave sites thus far explored for ancient DNA preservation, and highlights the great promise Kangaroo Island caves hold for yielding the hitherto-elusive DNA of extinct Australian Pleistocene species.

  2. The Persistence of PCBs.

    ERIC Educational Resources Information Center

    Boyle, Robert H.; Highland, Joseph H.

    1979-01-01

    PCB's are one of the most persistent chemicals ever introduced into the environment by man. From very early in their history of manufacture PCB's were suspected of being hazardous to health, but public awareness of the hazard was slow in coming. (RE)

  3. A Very Persistent Mistake

    ERIC Educational Resources Information Center

    McClelland, J. A. G.

    2011-01-01

    Articulated bodies with an internal energy source require to be coupled to an external mass in order to accelerate themselves but the typical text book assertion that the net force is provided by the external mass is not correct. Arguments are presented demonstrating that the assertion is incorrect and reasons are suggested for the persistence of…

  4. Persistence to Graduate Education.

    ERIC Educational Resources Information Center

    Ethington, Corinna A.; Smart, John C.

    1986-01-01

    A study is reported of the relationship of family education and income, high school grades, academic and social self-confidence, undergraduate institutional selectivity and size, academic and social integration, overall college satisfaction, bachelor's degree attainment, and financial aid on students' persistence to graduate school. (MSE)

  5. Thermal implications of interactions between insulation, solar reflectance, and fur structure in the summer coats of diverse species of kangaroo.

    PubMed

    Dawson, Terence J; Maloney, Shane K

    2017-04-01

    Not all of the solar radiation that impinges on a mammalian coat is absorbed and converted into thermal energy at the coat surface. Some is reflected back to the environment, while another portion is reflected further into the coat where it is absorbed and manifested as heat at differing levels. Substantial insulation in a coat limits the thermal impact at the skin of solar radiation, irrespective where in the coat it is absorbed. In coats with low insulation, the zone where solar radiation is absorbed may govern the consequent heat load on the skin (HL-SR). Thin summer furs of four species of kangaroo from differing climatic zones were used to determine how variation in insulation and in coat spectral and structural characteristics influence the HL-SR. Coat depth, structure, and solar reflectance varied between body regions, as well as between species. The modulation of solar radiation and resultant heat flows in these coats were measured at low (1 m s(-1)) and high (6 m s(-1)) wind speeds by mounting them on a heat flux transducer/temperature-controlled plate apparatus in a wind tunnel. A lamp with a spectrum similar to solar radiation was used as a proxy for the sun. We established that coat insulation was largely determined by coat depth at natural fur lie, despite large variations in fibre density, fibre diameter, and fur mass. Higher wind speed decreased coat insulation, but depth still determined the overall level. A multiple regression analysis that included coat depth (insulation), fibre diameter, fibre density, and solar reflectance was used to determine the best predictors of HL-SR. Only depth and reflectance had significant impacts and both factors had negative weights, so, as either insulation or reflectance increased, HL-SR declined, the larger impact coming from coat reflectance. This reverses the pattern observed in deep coats where insulation dominates over effects of reflectance. Across all coats, as insulation declined, reflectance increased

  6. Geographic patterns of genetic differentiation within the restricted range of the endangered Stephens' kangaroo rat Dipodomys stephensi.

    PubMed

    Metcalf, A E; Nunney, L; Hyman, B C

    2001-06-01

    Using mtDNA variation in the kangaroo rat Dipodomys stephensi, we found no support for the hypothesis that a species with an historically restricted range will exhibit low levels of genetic polymorphism and little genetic structure. Dipodomys stephensi has long been restricted to a few interior coastal valleys in southern California encompassing an area of approximately 70 x 40 km; however, we found high levels of genetic variation over much of its range and significant genetic structure both within and between regions. We also found evidence for a recent range expansion. Dipodomys stephensi is a federally endangered species that is separated from D. panamintinus, its presumed sister taxon, by a mountain range to the north. We assessed genetic variation by sequencing 645 bases of the mitochondrial d-loop from 61 individuals sampled from 16 locations across the species range and rooted their relationship using two D. panamintinus individuals. Despite its limited geographic range, the level of mtDNA variation in D. stephensi is comparable to that of other rodents, including that of the more widely distributed D. panamintinus. This variation revealed significant regional differentiation. The northern, central, and southern regions of the range differ in both the level and the distribution of genetic variation. Phylogenetic analysis revealed that the center of the range contains the most diversity of lineages, including the most basal. In this region and in the north, most haplotypes were found at only a single location (25/29), or at a pair of nearby locations (3/29). In addition, related haplotypes clustered geographically. These results are consistent with long-term demographic stability characterized by limited dispersal and high local effective population size. Further support for this conclusion is the finding of unique diversity in two northern peripheral populations, Norco and Potrero Creek (PC). However, in sharp contrast, one haplotype (CC) was found at five

  7. Persistent interface fluid syndrome.

    PubMed

    Hoffman, Richard S; Fine, I Howard; Packer, Mark

    2008-08-01

    We present an unusual case of persistent interface fluid that would not resolve despite normal intraocular pressure and corneal endothelial replacement with Descemet-stripping endothelial keratoplasty. Dissection, elevation, and repositioning of the laser in situ keratomileusis flap were required to resolve the interface fluid. Circumferential corneal graft-host margin scar formation acting as a mechanical strut may have been the cause of the intractable interface fluid.

  8. Optimization and Persistence

    DTIC Science & Technology

    1997-09-01

    and production costs are amplified by first-time applica- tion of high technology , security, and lim- ited production quantities. Alternate can...stred spendmg levels, average fleet age, average " technological advantage" of the fleet, and so forth. (The persistent features we discuss have all...a precise concept when dealing with nonmonetary units, such as technological advantage, but all elastic penalties are usually adjusted by the same

  9. 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.

  10. Investigation of the mechanical behavior of kangaroo humeral head cartilage tissue by a porohyperelastic model based on the strain-rate-dependent permeability.

    PubMed

    Thibbotuwawa, Namal; Oloyede, Adekunle; Senadeera, Wijitha; Li, Tong; Gu, YuanTong

    2015-11-01

    Solid-interstitial fluid interaction, which depends on tissue permeability, is significant to the strain-rate-dependent mechanical behavior of humeral head (shoulder) cartilage. Due to anatomical and biomechanical similarities to that of the human shoulder, kangaroos present a suitable animal model. Therefore, indentation experiments were conducted on kangaroo shoulder cartilage tissues from low (10(-4)/s) to moderately high (10(-2)/s) strain-rates. A porohyperelastic model was developed based on the experimental characterization; and a permeability function that takes into account the effect of strain-rate on permeability (strain-rate-dependent permeability) was introduced into the model to investigate the effect of rate-dependent fluid flow on tissue response. The prediction of the model with the strain-rate-dependent permeability was compared with those of the models using constant permeability and strain-dependent permeability. Compared to the model with constant permeability, the models with strain-dependent and strain-rate-dependent permeability were able to better capture the experimental variation at all strain-rates (p < 0.05). Significant differences were not identified between models with strain-dependent and strain-rate-dependent permeability at strain-rate of 5 × 10(-3)/s (p = 0.179). However, at strain-rate of 10(-2)/s, the model with strain-rate-dependent permeability was significantly better at capturing the experimental results (p < 0.005). The findings thus revealed the significance of rate-dependent fluid flow on tissue behavior at large strain-rates, which provides insights into the mechanical deformation mechanisms of cartilage tissues.

  11. Passage marker excretion in red kangaroo (Macropus rufus), collared peccary (Pecari tajacu) and colobine monkeys (Colobus angolensis, C. polykomos, Trachypithecus johnii).

    PubMed

    Schwarm, Angela; Ortmann, Sylvia; Wolf, Christian; Streich, W Jürgen; Clauss, Marcus

    2009-11-01

    Ruminants are characterized by an efficient particle-sorting mechanism in the forestomach (FRST) followed by selective rechewing of large food particles. For the nonruminating foregut fermenter pygmy hippo it was demonstrated that large particles are excreted as fast as, or faster than, the small particles. The same has been suggested for other nonruminating foregut fermenters. We determined the mean retention time of fluids and different-sized particles in six red kangaroos (Macropus rufus), seven collared peccaries (Pecari tajacu) and three colobine monkeys (Colobus angolensis, C. polykomos, Trachypithecus johnii). We fed Co-EDTA as fluid and mordanted fiber as particle markers (Cr, Ce). Mean (+ or - SD) total tract retention time for fluids, small and large particles was 14 + or - 2, 29 + or - 10 and 30 + or - 9 hr in red kangaroos, 26 + or - 2, 34 + or - 5 and 32 + or - 3 hr in collared peccaries and 57 + or - 17, 55 + or - 19 and 54 + or - 19 hr in colobine monkeys, respectively. Large and small particles were excreted simultaneously in all species. There was no difference in the excretion of fluids and particles in the colobine monkeys, in contrast to the other foregut fermenters. In the nonprimate, nonruminant foregut fermenters, the difference in the excretion of fluids and small particles decreases with increasing food intake. On the contrary, ruminants keep this differential excretion constant at different intake levels. This may be a prerequisite for the sorting of particles in their FRST and enable them to achieve higher food intake rates. The functional significance of differential excretion of fluids and particles from the FRST requires further investigations.

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

    PubMed

    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.

  13. 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

  14. Polycyclic hydrocarbon biomarkers confirm selective incorporation of petroleum in soil and kangaroo rat liver samples near an oil well blowout site in the western San Joaquin Valley, California

    SciTech Connect

    Kaplan, I.; Lu, S.T.; Lee, R.P.; Warrick, G.

    1996-05-01

    Following an accidental oil well blow out at an oil field in the western part of the San Joaquin Valley, soil samples and specimens of Heermann`s kangaroo rats (Dipodomys heermanni) were collected from two oil-impacted areas and one control area. Fingerprinting by GC-MS and quantitative evaluation of metabolized petroleum hydrocarbons was performed on oil, soil extracts, and rat livers. A liver from a domestically raised rabbit was used as an experimental control. The results show that there is no significant incorporation of PAHs or low molecular weight n-alkanes (C{sub 13}--C{sub 25}) into the liver tissues. The C{sub 25}--C{sub 35} n-alkane range for all soil samples, kangaroo rat livers, and rabbit liver, is dominated by a high abundance of C{sub 27}, C{sub 29}, C{sub 31}, and C{sub 33} hydrocarbons typical of epicuticular plant waxes. In all liver tissue samples, squalene, the cholesterol precursor, is the dominant hydrocarbon. Although evidence is lacking for metabolism of PAHs and paraffinic petroleum hydrocarbons, very strong evidence is available for incorporation of a set of polycyclic hydrocarbons (biomarkers) belonging to the terpane, sterane, and monoaromatic and triaromatic sterane families, identified by ion monitoring at 191, 217, 253, and 231 m/z, respectively. Because these hydrocarbons are not known to exist in the biosphere, but are only synthesized during oil- and coal-forming processes, their presence in the liver samples constitutes proof for crude oil incorporation into tissues. This conclusion is further substantiated by the selective incorporation of only the 20S enantiomer of C{sub 28} and C{sub 29} steranes and aromatic steranes into the livers, with the exclusion of the 20R enantiomer. The results from the study conclusively demonstrate that polycyclic hydrocarbon biomarkers provide excellent indices for proof of petroleum exposure and metabolism in some terrestrial herbivores.

  15. Persistent Temporal Streams

    NASA Astrophysics Data System (ADS)

    Hilley, David; Ramachandran, Umakishore

    Distributed continuous live stream analysis applications are increasingly common. Video-based surveillance, emergency response, disaster recovery, and critical infrastructure protection are all examples of such applications. They are characterized by a variety of high- and low-bandwidth streams as well as a need for analyzing both live and archived streams. We present a system called Persistent Temporal Streams (PTS) that supports a higher-level, domain-targeted programming abstraction for such applications. PTS provides a simple but expressive stream abstraction encompassing transport, manipulation and storage of streaming data. In this paper, we present a system architecture for implementing PTS. We provide an experimental evaluation which shows the system-level primitives can be implemented in a lightweight and high-performance manner, and an application-based evaluation designed to show that a representative high-bandwidth stream analysis application can be implemented relatively simply and with good performance.

  16. Persistent Genital Arousal Disorder

    PubMed Central

    Aswath, Manju; Pandit, Lakshmi V.; Kashyap, Karthik; Ramnath, Raguram

    2016-01-01

    Persistent genital arousal disorder (PGAD) is a phenomenon, in which afflicted women experience spontaneous genital arousal, unresolved by orgasms and triggered by sexual or nonsexual stimuli, eliciting stress. The current case is a 40-year-old female who experienced such orgasms for about a month. Physical examination, investigations, and psychological testing were noncontributory. Carbamazepine (600 mg) was discontinued due to a lack of response. She improved significantly with supportive therapy. Various neuropsychological conditions, pelvic pathology, medications, etc., have been associated with this disorder. Pharmacologic strategies have included the use of antidepressants, antipsychotics, mood stabilizers, and analgesics. Validation, psycho-education, identifying triggers, distraction techniques, and pelvic massage have been tried. Living with PGAD is very demanding. There is a lack of understanding of the problem, shame, and hesitation to seek help. The syndrome has been recently described, and understanding is still evolving. PMID:27570347

  17. Persistent Genital Arousal Disorder.

    PubMed

    Aswath, Manju; Pandit, Lakshmi V; Kashyap, Karthik; Ramnath, Raguram

    2016-01-01

    Persistent genital arousal disorder (PGAD) is a phenomenon, in which afflicted women experience spontaneous genital arousal, unresolved by orgasms and triggered by sexual or nonsexual stimuli, eliciting stress. The current case is a 40-year-old female who experienced such orgasms for about a month. Physical examination, investigations, and psychological testing were noncontributory. Carbamazepine (600 mg) was discontinued due to a lack of response. She improved significantly with supportive therapy. Various neuropsychological conditions, pelvic pathology, medications, etc., have been associated with this disorder. Pharmacologic strategies have included the use of antidepressants, antipsychotics, mood stabilizers, and analgesics. Validation, psycho-education, identifying triggers, distraction techniques, and pelvic massage have been tried. Living with PGAD is very demanding. There is a lack of understanding of the problem, shame, and hesitation to seek help. The syndrome has been recently described, and understanding is still evolving.

  18. New daily persistent headache.

    PubMed

    Tyagi, Alok

    2012-08-01

    New daily persistent headache (NDPH) is a chronic headache developing in a person who does not have a past history of headaches. The headache begins acutely and reaches its peak within 3 days. It is important to exclude secondary causes, particularly headaches due to alterations in cerebrospinal fluid (CSF) pressure and volume. A significant proportion of NDPH sufferers may have intractable headaches that are refractory to treatment. The condition is best viewed as a syndrome rather than a diagnosis. The headache can mimic chronic migraine and chronic tension-type headache, and it is also important to exclude secondary causes, particularly headaches due to alterations in CSF pressure and volume. A large proportion of NDPH sufferers have migrainous features to their headache and should be managed with treatments used for treating migraine. A small group of NDPH sufferers may have intractable headaches that are refractory to treatment.

  19. Epigenetic regulation of persistent pain

    PubMed Central

    Bai, Guang; Ren, Ke; Dubner, Ronald

    2014-01-01

    Persistent or chronic pain is tightly associated with various environmental changes and linked to abnormal gene expression within cells processing nociceptive signaling. Epigenetic regulation governs gene expression in response to environmental cues. Recent animal model and clinical studies indicate that epigenetic regulation plays an important role in the development/maintenance of persistent pain and, possibly the transition of acute pain to chronic pain, thus shedding light in a direction for development of new therapeutics for persistent pain. PMID:24948399

  20. Isolated persistent hypermethioninemia.

    PubMed Central

    Mudd, S H; Levy, H L; Tangerman, A; Boujet, C; Buist, N; Davidson-Mundt, A; Hudgins, L; Oyanagi, K; Nagao, M; Wilson, W G

    1995-01-01

    New information has been obtained on 30 patients with isolated persistent hypermethioninemia, most of them previously unreported. Biopsies to confirm the presumptive diagnosis of partially deficient activity of ATP: L-methionine S-adenosyltransferase (MAT; E.C.2.5.1.6) in liver were not performed on most of these patients. However, none showed the clinical findings or the extreme elevations of serum folate previously described in other patients with isolated hypermethioninemia considered not to have hepatic MAT deficiency. Patients ascertained on biochemical grounds had no neurological abnormalities, and 27/30 had IQs or Bayley development-index scores within normal limits or were judged to have normal mental development. Methionine transamination metabolites accumulated abnormally only when plasma methionine concentrations exceeded 300-350 microM and did so more markedly after 0.9 years of age. Data were obtained on urinary organic acids as well as plasma creatinine concentrations. Patterns of inheritance of isolated hypermethioninemia were variable. Considerations as to the optimal management of this group of patients are discussed. PMID:7573050

  1. Persistence. Snapshot Report, Fall 2011

    ERIC Educational Resources Information Center

    National Student Clearinghouse, 2011

    2011-01-01

    Today's college student is not your '60s drop-out. In 2010, college students tended to stay enrolled (i.e., persist), even if it was in a different school, according to the National Student Clearinghouse Research Center. For a student enrolled in the fall, persistence is defined as either continued enrollment during the next term after the fall or…

  2. Metabolic aspects of bacterial persisters

    PubMed Central

    Prax, Marcel; Bertram, Ralph

    2014-01-01

    Persister cells form a multi-drug tolerant subpopulation within an isogenic culture of bacteria that are genetically susceptible to antibiotics. Studies with different Gram negative and Gram positive bacteria have identified a large number of genes associated with the persister state. In contrast, the revelation of persister metabolism has only been addressed recently. We here summarize metabolic aspects of persisters, which includes an overview about the bifunctional role of selected carbohydrates as both triggers for the exit from the drug tolerant state and metabolites which persisters feed on. Also alarmones as indicators for starvation have been shown to influence persister levels via different signaling cascades involving the activation of toxin-antitoxin systems and other regulatory factors. Finally, recent data obtained by 13C-isotopolog profiling demonstrated an active amino acid anabolism in Staphylococcus aureus cultures challenged with high drug concentrations. Understanding the metabolism of persister cells poses challenges but also paves the way for the development of anti-persister compounds. PMID:25374846

  3. Multidimensional persistence in biomolecular data

    PubMed Central

    Xia, Kelin; Wei, Guo-Wei

    2015-01-01

    Persistent homology has emerged as a popular technique for the topological simplification of big data, including biomolecular data. Multidimensional persistence bears considerable promise to bridge the gap between geometry and topology. However, its practical and robust construction has been a challenge. We introduce two families of multidimensional persistence, namely pseudo-multidimensional persistence and multiscale multidimensional persistence. The former is generated via the repeated applications of persistent homology filtration to high dimensional data, such as results from molecular dynamics or partial differential equations. The latter is constructed via isotropic and anisotropic scales that create new simiplicial complexes and associated topological spaces. The utility, robustness and efficiency of the proposed topological methods are demonstrated via protein folding, protein flexibility analysis, the topological denoising of cryo-electron microscopy data, and the scale dependence of nano particles. Topological transition between partial folded and unfolded proteins has been observed in multidimensional persistence. The separation between noise topological signatures and molecular topological fingerprints is achieved by the Laplace-Beltrami flow. The multiscale multidimensional persistent homology reveals relative local features in Betti-0 invariants and the relatively global characteristics of Betti-1 and Betti-2 invariants. PMID:26032339

  4. Persistent Criminality and Career Length

    ERIC Educational Resources Information Center

    Haapanen, Rudy; Britton, Lee; Croisdale, Tim

    2007-01-01

    This study is an examination of persistent offending and its implications for the understanding and investigation of desistance and career length. Persistence, especially as it is operationalized using official measures, is characterized as fundamentally a measure of resistance to formal social control: continued crime in the face of increasingly…

  5. Persistence, resistance, resonance

    NASA Astrophysics Data System (ADS)

    Tsadka, Maayan

    form of musical consumption and experience. The three pieces draw lines connecting different aspects of persistence, resistance, and resonance.

  6. Energy landscapes and persistent minima

    SciTech Connect

    Carr, Joanne M.; Wales, David J.; Mazauric, Dorian; Cazals, Frédéric

    2016-02-07

    We consider a coarse-graining of high-dimensional potential energy landscapes based upon persistences, which correspond to lowest barrier heights to lower-energy minima. Persistences can be calculated efficiently for local minima in kinetic transition networks that are based on stationary points of the prevailing energy landscape. The networks studied here represent peptides, proteins, nucleic acids, an atomic cluster, and a glassy system. Minima with high persistence values are likely to represent some form of alternative structural morphology, which, if appreciably populated at the prevailing temperature, could compete with the global minimum (defined as infinitely persistent). Threshold values on persistences (and in some cases equilibrium occupation probabilities) have therefore been used in this work to select subsets of minima, which were then analysed to see how well they can represent features of the full network. Simplified disconnectivity graphs showing only the selected minima can convey the funnelling (including any multiple-funnel) characteristics of the corresponding full graphs. The effect of the choice of persistence threshold on the reduced disconnectivity graphs was considered for a system with a hierarchical, glassy landscape. Sets of persistent minima were also found to be useful in comparing networks for the same system sampled under different conditions, using minimum oriented spanning forests.

  7. [MOLECULAR ASPECTS OF BRUCELLA PERSISTENCE].

    PubMed

    Kulakov Yu K

    2016-01-01

    Brucellosis is a dangerous zoonotic disease of animals and humans caused by bacteria of the genus Brucella, which are able to survive, multiply, and persist in host cells. The review is devoted to the Brucella species persistence connected to the molecular mechanisms of escape from innate and adaptive immunity of the host and active interaction of effector proteins of the type IV secretion system with the host's signaling pathways. Understanding of the molecular mechanisms used by Brucella for the intracellular persistence in the host organism can allow us to develop new and effective means for the prevention and treatment of chronic brucellosis infection.

  8. Genetic diversity in captive and wild Matschie's tree kangaroo (Dendrolagus matschiei) from Huon Peninsula, Papua New Guinea, based on mtDNA control region sequences.

    PubMed

    McGreevy, Thomas J; Dabek, Lisa; Gomez-Chiarri, Marta; Husband, Thomas P

    2009-05-01

    The Association of Zoos and Aquariums (AZA) Matschie's tree kangaroo (Dendrolagus matschiei) population is at a critical point for assessing long-term viability. This population, established from 19 genetically uncharacterized D. matschiei, has endured a founder effect because only four individuals contributed the majority of offspring. The highly variable mitochondrial DNA (mtDNA) control region was sequenced for five of the female-founders by examining extant representatives of their maternal lineage and compared with wild (n = 13) and captive (n = 18) D. matschiei from Papua New Guinea (PNG). AZA female-founder D. matschiei control region haplotype diversity was low, compared with captive D. matschiei held in PNG. AZA D. matschiei have only two control region haplotypes because four out of five AZA female-founder D. matschiei had an identical sequence. Both AZA haplotypes were identified among the 17 wild and captive D. matschiei haplotypes from PNG. Genomic DNA extracted from wild D. matschiei fecal samples was a reliable source of mtDNA that could be used for a larger scale study. We recommend a nuclear DNA genetic analysis to more fully characterize AZA D. matschiei genetic diversity and to assist their Species Survival Plan((R)). An improved understanding of D. matschiei genetics will contribute substantially to the conservation of these unique animals both in captivity and the wild.

  9. Rattlesnakes are extremely fast and variable when striking at kangaroo rats in nature: Three-dimensional high-speed kinematics at night

    PubMed Central

    Higham, Timothy E.; Clark, Rulon W.; Collins, Clint E.; Whitford, Malachi D.; Freymiller, Grace A.

    2017-01-01

    Predation plays a central role in the lives of most organisms. Predators must find and subdue prey to survive and reproduce, whereas prey must avoid predators to do the same. The resultant antagonistic coevolution often leads to extreme adaptations in both parties. Few examples capture the imagination like a rapid strike from a venomous snake. However, almost nothing is known about strike performance of viperid snakes under natural conditions. We obtained high-speed (500 fps) three-dimensional video in the field (at night using infrared lights) of Mohave rattlesnakes (Crotalus scutulatus) attempting to capture Merriam’s kangaroo rats (Dipodomys merriami). Strikes occurred from a range of distances (4.6 to 20.6 cm), and rattlesnake performance was highly variable. Missed capture attempts resulted from both rapid escape maneuvers and poor strike accuracy. Maximum velocity and acceleration of some rattlesnake strikes fell within the range of reported laboratory values, but some far exceeded most observations. Thus, quantifying rapid predator-prey interactions in the wild will propel our understanding of animal performance. PMID:28084400

  10. Rattlesnakes are extremely fast and variable when striking at kangaroo rats in nature: Three-dimensional high-speed kinematics at night.

    PubMed

    Higham, Timothy E; Clark, Rulon W; Collins, Clint E; Whitford, Malachi D; Freymiller, Grace A

    2017-01-13

    Predation plays a central role in the lives of most organisms. Predators must find and subdue prey to survive and reproduce, whereas prey must avoid predators to do the same. The resultant antagonistic coevolution often leads to extreme adaptations in both parties. Few examples capture the imagination like a rapid strike from a venomous snake. However, almost nothing is known about strike performance of viperid snakes under natural conditions. We obtained high-speed (500 fps) three-dimensional video in the field (at night using infrared lights) of Mohave rattlesnakes (Crotalus scutulatus) attempting to capture Merriam's kangaroo rats (Dipodomys merriami). Strikes occurred from a range of distances (4.6 to 20.6 cm), and rattlesnake performance was highly variable. Missed capture attempts resulted from both rapid escape maneuvers and poor strike accuracy. Maximum velocity and acceleration of some rattlesnake strikes fell within the range of reported laboratory values, but some far exceeded most observations. Thus, quantifying rapid predator-prey interactions in the wild will propel our understanding of animal performance.

  11. Integration of genotoxicity and population genetic analyses in kangaroo rats (Dipodomys merriami) exposed to radionuclide contamination at the Nevada Test Site, USA.

    PubMed

    Theodorakis, C W; Bickham, J W; Lamb, T; Medica, P A; Lyne, T B

    2001-02-01

    We examined effects of radionuclide exposure at two atomic blast sites on kangaroo rats (Dipodomys merriami) at the Nevada Test Site, Nevada, USA, using genotoxicity and population genetic analyses. We assessed chromosome damage by micronucleus and flow cytometric assays and genetic variation by randomly amplified polymorphic DNA (RAPD) and mitochondrial DNA (mtDNA) analyses. The RAPD analysis showed no population structure, but mtDNA exhibited differentiation among and within populations. Genotoxicity effects were not observed when all individuals were analyzed. However, individuals with mtDNA haplotypes unique to the contaminated sites had greater chromosomal damage than contaminated-site individuals with haplotypes shared with reference sites. When interpopulation comparisons used individuals with unique haplotypes, one contaminated site had greater levels of chromosome damage than one or both of the reference sites. We hypothesize that shared-haplotype individuals are potential migrants and that unique-haplotye individuals are potential long-term residents. A parsimony approach was used to estimate the minimum number of migration events necessary to explain the haplotype distributions on a phylogenetic tree. The observed predominance of migration events into the contaminated sites supported our migration hypothesis. We conclude the atomic blast sites are ecological sinks and that immigration masks the genotoxic effects of radiation on the resident populations.

  12. Integration of genotoxicity and population genetic analyses in kangaroo rats (Dipodomys merriami) exposed to radionuclide contamination at the Nevada Test Site, USA

    USGS Publications Warehouse

    Theodorakis, Christopher W.; Bickham, John W.; Lamb, Trip; Medica, Philip A.; Lyne, T. Barrett

    2001-01-01

    We examined effects of radionuclide exposure at two atomic blast sites on kangaroo rats (Dipodomys merriami) at the Nevada Test Site, Nevada, USA, using genotoxicity and population genetic analyses. We assessed chromosome damage by micronucleus and flow cytometric assays and genetic variation by randomly amplified polymorphic DNA (RAPD) and mitochondrial DNA (mtDNA) analyses. The RAPD analysis showed no population structure, but mtDNA exhibited differentiation among and within populations. Genotoxicity effects were not observed when all individuals were analyzed. However, individuals with mtDNA haplotypes unique to the contaminated sites had greater chromosomal damage than contaminated-site individuals with haplotypes shared with reference sites. When interpopulation comparisons used individuals with unique haplotypes, one contaminated site had greater levels of chromosome damage than one or both of the reference sites. We hypothesize that shared-haplotype individuals are potential migrants and that unique-haplotype individuals are potential long-term residents. A parsimony approach was used to estimate the minimum number of migration events necessary to explain the haplotype distributions on a phylogenetic tree. The observed predominance of migration events into the contaminated sites supported our migration hypothesis. We conclude the atomic blast sites are ecological sinks and that immigration masks the genotoxic effects of radiation on the resident populations.

  13. Immunomodulation by Persistent Organic Pollutants

    EPA Science Inventory

    Persistent organic pollutants (POPs) are widely distnbuted in the environment, are resistant to degradation, and increase in concentration (biomagnify) in the food chain. Concentrations in apical predators may be tens to hundreds of times greater than concentrations in their pref...

  14. Prenatal diagnosis of persistent cloaca.

    PubMed

    Suzumori, Nobuhiro; Obayashi, Shintaro; Hattori, Yukio; Kaneko, Saori; Suzuki, Yoshikatsu; Sugiura-Ogasawara, Mayumi

    2009-09-01

    We report four cases of persistent cloaca diagnosed at 32-33 weeks of gestation. In cases of persistent cloaca, serial prenatal ultrasonography shows transient fetal ascites, enlarged cystic structures arising from the fetal pelvis. Our four cases of persistent cloaca were diagnosed prenatally. Persistent cloaca should be considered in any female fetus presenting with hydronephrosis and a large cystic lesion arising from the pelvis as assessed by ultrasound and magnetic resonance imaging. Neither pulmonary hypoplasia nor severe oligohydramnios were found in any of our four cases, and they each had a good prognosis. Prenatal diagnosis allows time for parental counseling and delivery planning at a tertiary care center for neonatal intensive care and pediatric surgery.

  15. Object-oriented Persistent Homology

    PubMed Central

    Wang, Bao; Wei, Guo-Wei

    2015-01-01

    Persistent homology provides a new approach for the topological simplification of big data via measuring the life time of intrinsic topological features in a filtration process and has found its success in scientific and engineering applications. However, such a success is essentially limited to qualitative data classification and analysis. Indeed, persistent homology has rarely been employed for quantitative modeling and prediction. Additionally, the present persistent homology is a passive tool, rather than a proactive technique, for classification and analysis. In this work, we outline a general protocol to construct object-oriented persistent homology methods. By means of differential geometry theory of surfaces, we construct an objective functional, namely, a surface free energy defined on the data of interest. The minimization of the objective functional leads to a Laplace-Beltrami operator which generates a multiscale representation of the initial data and offers an objective oriented filtration process. The resulting differential geometry based object-oriented persistent homology is able to preserve desirable geometric features in the evolutionary filtration and enhances the corresponding topological persistence. The cubical complex based homology algorithm is employed in the present work to be compatible with the Cartesian representation of the Laplace-Beltrami flow. The proposed Laplace-Beltrami flow based persistent homology method is extensively validated. The consistence between Laplace-Beltrami flow based filtration and Euclidean distance based filtration is confirmed on the Vietoris-Rips complex for a large amount of numerical tests. The convergence and reliability of the present Laplace-Beltrami flow based cubical complex filtration approach are analyzed over various spatial and temporal mesh sizes. The Laplace-Beltrami flow based persistent homology approach is utilized to study the intrinsic topology of proteins and fullerene molecules. Based on a

  16. Object-oriented Persistent Homology.

    PubMed

    Wang, Bao; Wei, Guo-Wei

    2016-01-15

    Persistent homology provides a new approach for the topological simplification of big data via measuring the life time of intrinsic topological features in a filtration process and has found its success in scientific and engineering applications. However, such a success is essentially limited to qualitative data classification and analysis. Indeed, persistent homology has rarely been employed for quantitative modeling and prediction. Additionally, the present persistent homology is a passive tool, rather than a proactive technique, for classification and analysis. In this work, we outline a general protocol to construct object-oriented persistent homology methods. By means of differential geometry theory of surfaces, we construct an objective functional, namely, a surface free energy defined on the data of interest. The minimization of the objective functional leads to a Laplace-Beltrami operator which generates a multiscale representation of the initial data and offers an objective oriented filtration process. The resulting differential geometry based object-oriented persistent homology is able to preserve desirable geometric features in the evolutionary filtration and enhances the corresponding topological persistence. The cubical complex based homology algorithm is employed in the present work to be compatible with the Cartesian representation of the Laplace-Beltrami flow. The proposed Laplace-Beltrami flow based persistent homology method is extensively validated. The consistence between Laplace-Beltrami flow based filtration and Euclidean distance based filtration is confirmed on the Vietoris-Rips complex for a large amount of numerical tests. The convergence and reliability of the present Laplace-Beltrami flow based cubical complex filtration approach are analyzed over various spatial and temporal mesh sizes. The Laplace-Beltrami flow based persistent homology approach is utilized to study the intrinsic topology of proteins and fullerene molecules. Based on a

  17. Object-oriented persistent homology

    NASA Astrophysics Data System (ADS)

    Wang, Bao; Wei, Guo-Wei

    2016-01-01

    Persistent homology provides a new approach for the topological simplification of big data via measuring the life time of intrinsic topological features in a filtration process and has found its success in scientific and engineering applications. However, such a success is essentially limited to qualitative data classification and analysis. Indeed, persistent homology has rarely been employed for quantitative modeling and prediction. Additionally, the present persistent homology is a passive tool, rather than a proactive technique, for classification and analysis. In this work, we outline a general protocol to construct object-oriented persistent homology methods. By means of differential geometry theory of surfaces, we construct an objective functional, namely, a surface free energy defined on the data of interest. The minimization of the objective functional leads to a Laplace-Beltrami operator which generates a multiscale representation of the initial data and offers an objective oriented filtration process. The resulting differential geometry based object-oriented persistent homology is able to preserve desirable geometric features in the evolutionary filtration and enhances the corresponding topological persistence. The cubical complex based homology algorithm is employed in the present work to be compatible with the Cartesian representation of the Laplace-Beltrami flow. The proposed Laplace-Beltrami flow based persistent homology method is extensively validated. The consistence between Laplace-Beltrami flow based filtration and Euclidean distance based filtration is confirmed on the Vietoris-Rips complex for a large amount of numerical tests. The convergence and reliability of the present Laplace-Beltrami flow based cubical complex filtration approach are analyzed over various spatial and temporal mesh sizes. The Laplace-Beltrami flow based persistent homology approach is utilized to study the intrinsic topology of proteins and fullerene molecules. Based on a

  18. Risk factors for persistent diarrhoea.

    PubMed

    Shahid, N S; Sack, D A; Rahman, M; Alam, A N; Rahman, N

    1988-10-22

    With a systematically sampled population of children aged under 5 attending this centre for diarrhoeal disease research during 1983-5 a retrospective analysis of persistent diarrhoea (defined as greater than 14 days' duration) was performed to identify the possible risk factors for this syndrome. Of the 4155 children included in the analysis, 410 (10%) gave a history of persistent diarrhoea. A comparison with children with acute diarrhoea matched for age showed that 11 factors were correlated with persistent diarrhoea, and strongly associated factors were stools with blood or mucus, or both, lower respiratory tract infection, malnutrition, vitamin A deficiency, and antibiotic use before presentation. The peak age was 2 years, and there was no sex difference. Deaths occurred more often in the group with persistent diarrhoea. Although Shigella spp, Campylobacter jejuni, and Giardia lamblia were frequently identified, their rates of isolation were not significantly higher among patients with persistent diarrhoea. No seasonal variation was observed in the rates of persistent diarrhoea. Although the introduction of family food to the diet was associated with higher rates, this factor was difficult to separate from the age dependent risks.

  19. Risk factors for persistent diarrhoea.

    PubMed Central

    Shahid, N. S.; Sack, D. A.; Rahman, M.; Alam, A. N.; Rahman, N.

    1988-01-01

    With a systematically sampled population of children aged under 5 attending this centre for diarrhoeal disease research during 1983-5 a retrospective analysis of persistent diarrhoea (defined as greater than 14 days' duration) was performed to identify the possible risk factors for this syndrome. Of the 4155 children included in the analysis, 410 (10%) gave a history of persistent diarrhoea. A comparison with children with acute diarrhoea matched for age showed that 11 factors were correlated with persistent diarrhoea, and strongly associated factors were stools with blood or mucus, or both, lower respiratory tract infection, malnutrition, vitamin A deficiency, and antibiotic use before presentation. The peak age was 2 years, and there was no sex difference. Deaths occurred more often in the group with persistent diarrhoea. Although Shigella spp, Campylobacter jejuni, and Giardia lamblia were frequently identified, their rates of isolation were not significantly higher among patients with persistent diarrhoea. No seasonal variation was observed in the rates of persistent diarrhoea. Although the introduction of family food to the diet was associated with higher rates, this factor was difficult to separate from the age dependent risks. PMID:3142603

  20. Energy Savings Lifetimes and Persistence

    SciTech Connect

    Hoffman, Ian M.; Schiller, Steven R.; Todd, Annika; Billingsley, Megan A.; Goldman, Charles A.; Schwartz, Lisa C.

    2016-02-01

    This technical brief explains the concepts of energy savings lifetimes and savings persistence and discusses how program administrators use these factors to calculate savings for efficiency measures, programs and portfolios. Savings lifetime is the length of time that one or more energy efficiency measures or activities save energy, and savings persistence is the change in savings throughout the functional life of a given efficiency measure or activity. Savings lifetimes are essential for assessing the lifecycle benefits and cost effectiveness of efficiency activities and for forecasting loads in resource planning. The brief also provides estimates of savings lifetimes derived from a national collection of costs and savings for electric efficiency programs and portfolios.

  1. Non-Persisting Student Follow-Up.

    ERIC Educational Resources Information Center

    Willett, Lynn H.

    A survey was conducted to determine the characteristics and opinions of the non-persisting students at Moraine Valley Community College. A random sample of 500 non-persisting students was selected, with equal numbers of full-time and part-time ex-students. Separate questionnaires were used for non-persisting full-time and non-persisting part-time…

  2. Kangaroo mother method: randomised controlled trial of an alternative method of care for stabilised low-birthweight infants. Maternidad Isidro Ayora Study Team.

    PubMed

    Sloan, N L; Camacho, L W; Rojas, E P; Stern, C

    1994-09-17

    Because resources for care of low-birthweight (LBW) infants in developing countries are scarce, the Kangaroo mother method (KMM) was developed. The infant is kept upright in skin-to-skin contact with the mother's breast. Previous studies reported several benefits with the KMM but interpretation of their findings is limited by small size and design weaknesses. We have done a longitudinal, randomised, controlled trial at the Isidro Ayora Maternity Hospital in Quito, Ecuador. Infants with LBW (< 2000 g) who satisfied out-of-risk criteria of tolerance of food and weight stabilisation were randomly assigned to KMM and control (standard incubator care) groups (n = 128 and 147, respectively). During 6 months of follow-up the KMM group had a significantly lower rate than the control group of serious illness (lower-respiratory-tract disorders, apnoea, aspiration, pneumonia, septicaemia, general infections; 7 [5%] vs 27 [18%], p < 0.002), although differences between the groups in less severe morbidity were not significant. There was no significant difference in growth or in the proportion of women breastfeeding, perhaps because the proportion breastfeeding was high in both groups owing to strong promotion. Mortality was the same in both groups; most deaths occurred during the stabilisation period before randomisation. KMM mothers made more unscheduled clinic visits than control mothers but their infants had fewer re-admissions and so the cost of care was lower with the KMM. Since the eligibility criteria excluded nearly 50% of LBW infants from the study, the KMM is not universally applicable to these infants. The benefits might be greater in populations where breastfeeding is not so common.

  3. Rhinophototherapy in persistent allergic rhinitis.

    PubMed

    Bella, Zsolt; Kiricsi, Ágnes; Viharosné, Éva Dósa-Rácz; Dallos, Attila; Perényi, Ádám; Kiss, Mária; Koreck, Andrea; Kemény, Lajos; Jóri, József; Rovó, László; Kadocsa, Edit

    2017-03-01

    Previous published results have revealed that Rhinolight(®) intranasal phototherapy is safe and effective in intermittent allergic rhinitis. The present objective was to assess whether phototherapy is also safe and effective in persistent allergic rhinitis. Thirty-four patients with persistent allergic rhinitis were randomized into two groups; twenty-five subjects completed the study. The Rhinolight(®) group was treated with a combination of UV-B, UV-A, and high-intensity visible light, while the placebo group received low-intensity visible white light intranasal phototherapy on a total of 13 occasions in 6 weeks. The assessment was based on the diary of symptoms, nasal inspiratory peak flow, quantitative smell threshold, mucociliary transport function, and ICAM-1 expression of the epithelial cells. All nasal symptom scores and nasal inspiratory peak flow measurements improved significantly in the Rhinolight(®) group relative to the placebo group and this finding persisted after 4 weeks of follow-up. The smell and mucociliary functions did not change significantly in either group. The number of ICAM-1 positive cells decreased non-significantly in the Rhinolight(®) group. No severe side-effects were reported during the treatment period. These results suggest that Rhinolight(®) treatment is safe and effective in persistent allergic rhinitis.

  4. Retrospection and Persistent School Absenteeism.

    ERIC Educational Resources Information Center

    Reid, Ken

    1983-01-01

    This paper presents and discusses data based on the perceptions of 128 persistent school absentees on their initial and continued reasons for missing school. The findings suggest that a greater proportion of the students were inclined to blame their institutions, rather than social or psychological factors, for their behavior. (SSH)

  5. Persistent Identifiers Implementation in EOSDIS

    NASA Technical Reports Server (NTRS)

    Ramapriyan, H. K. " Rama"

    2016-01-01

    This presentation provides the motivation for and status of implementation of persistent identifiers in NASA's Earth Observation System Data and Information System (EOSDIS). The motivation is provided from the point of view of long-term preservation of datasets such that a number of questions raised by current and future users can be answered easily and precisely. A number of artifacts need to be preserved along with datasets to make this possible, especially when the authors of datasets are no longer available to address users questions. The artifacts and datasets need to be uniquely and persistently identified and linked with each other for full traceability, understandability and scientific reproducibility. Current work in the Earth Science Data and Information System (ESDIS) Project and the Distributed Active Archive Centers (DAACs) in assigning Digital Object Identifiers (DOI) is discussed as well as challenges that remain to be addressed in the future.

  6. Persistent Monitoring Platforms Final Report

    SciTech Connect

    Bennett, C L

    2007-02-22

    This project was inspired and motivated by the need to provide better platforms for persistent surveillance. In the years since the inception of this work, the need for persistence of surveillance platforms has become even more widely appreciated, both within the defense community and the intelligence community. One of the most demanding technical requirements for such a platform involves the power plant and energy storage system, and this project concentrated almost exclusively on the technology associated with this system for a solar powered, high altitude, unmanned aircraft. An important realization for the feasibility of such solar powered aircraft, made at the outset of this project, was that thermal energy may be stored with higher specific energy density than for any other known practical form of rechargeable energy storage. This approach has proved to be extraordinarily fruitful, and a large number of spin-off applications of this technology were developed in the course of this project.

  7. Search along persistent random walks

    NASA Astrophysics Data System (ADS)

    Friedrich, Benjamin M.

    2008-06-01

    Optimal search strategies and their implementations in biological systems are a subject of active research. Here we study a search problem which is motivated by the hunt of sperm cells for the egg. We ask for the probability for an active swimmer to find a target under the condition that the swimmer starts at a certain distance from the target. We find that success probability is maximal for a certain level of fluctuations characterized by the persistence length of the swimming path of the swimmer. We derive a scaling law for the optimal persistence length as a function of the initial target distance and search time by mapping the search on a polymer physics problem.

  8. MOOCs and Persistence: Definitions and Predictors

    ERIC Educational Resources Information Center

    Evans, Brent J.; Baker, Rachel B.

    2016-01-01

    The chapter argues for redefining the term "persistence" as it relates to MOOCs and considers how different measures produce different results in the research; it closes with a review of research on persistence in MOOCs.

  9. PERSISTENT CONTAMINANTS: NEW PRIORITIES, NEW CONCERNS

    EPA Science Inventory


    The Stockholm Convention on persistent organic pollutants (POPs) was adopted in 2001 to protect human health and the environment from chemicals that are highly toxic, persistent, bioaccumulative, and undergo long range transport. These POPs include 9 pesticides, polychlorin...

  10. Divergence in sink contributions to population persistence

    EPA Science Inventory

    Population sinks present unique conservation challenges. The loss of animals in sinks can compromise persistence. Conversely, sinks can bolster population sizes, improving viability. To assess the contribution of sinks to regional persistence, we simulated the removal of sink hab...

  11. The Extraction of Information From Visual Persistence

    ERIC Educational Resources Information Center

    Erwin, Donald E.

    1976-01-01

    This research sought to distinguish among three concepts of visual persistence by substituting the physical presence of the target stimulus while simultaneously inhibiting the formation of a persisting representation. Reportability of information about the stimuli was compared to a condition in which visual persistence was allowed to fully develop…

  12. A Grounded Theory of Adult Student Persistence

    ERIC Educational Resources Information Center

    Capps, Rosemary

    2010-01-01

    This grounded theory study investigates adult student persistence at a community college. Student persistence in college is a prerequisite for degree achievement, which correlates with higher earnings and overall better quality of life. Persistence rates remain low for adult students, who combine their college endeavors with responsibilities to…

  13. Intent to Persist at Religiously Affiliated Universities

    ERIC Educational Resources Information Center

    Sansom, J. Mel

    2012-01-01

    The purpose of the secondary data analysis was to examine the attributes of students who intend to persist at the same religiously affiliated institution. The review of literature indicated that persistence has been studied extensively, but there has been only limited investigation of persistence focused on religiously affiliated institutions. The…

  14. Persistence-Retention. Snapshot™ Report, Spring 2015

    ERIC Educational Resources Information Center

    National Student Clearinghouse, 2015

    2015-01-01

    This Snapshot Report offers information on student persistence and retention rates for 2009-2013. It offers data on the following: (1) First-Year Persistence and Retention Rates for Students Who Start College at Four-Year Private Nonprofit Institutions; (2) First-Year Persistence and Retention Rates for Students Who Start College at Four-Year…

  15. Persistence-Retention. Snapshot™ Report, Spring 2014

    ERIC Educational Resources Information Center

    National Student Clearinghouse, 2014

    2014-01-01

    This snapshot report provides information on student persistence and retention rates for Spring 2014. Data is presented in tabular format on the following: (1) First-Year Persistence and Retention Rates by Starting Enrollment Intensity (all institutional sectors); (2) First-Year Persistence and Retention Rates by Age at College Entry (all…

  16. Comparative NMR studies of diffusional water permeability of red blood cells from different species: XV. Agile wallaby (Macropus agilis), red-necked wallaby (Macropus rufogriseus) and Goodfellow's tree kangaroo (Dendrolagus goodfellowi).

    PubMed

    Benga, Gheorghe; Chapman, Bogdan E; Kuchel, Philip W

    2009-09-01

    The water diffusional permeability (P(d)) of red blood cells (RBC) from agile wallaby (Macropus agilis), red-necked wallaby (Macropus rufogriseus) and Goodfellow's tree kangaroo (Dendrolagus goodfellowi) was monitored using an Mn(2+)-doping (1)H nuclear magnetic resonance (NMR) technique at 400 MHz. The P(d) (cm s(-1)) values of agile wallaby RBCs were 7.5 x 10(-3) at 25 degrees C, 9 x 10(-3) at 30 degrees C, 11 x 10(-3) at 37 degrees C, and 13 x 10(-3) at 42 degrees C. The inhibitory effect of a mercury-containing sulfhydryl (SH)-modifying reagent p-chloromercuribenzoate (PCMB) on agile wallaby RBCs was investigated. The maximal inhibition was reached in 90 min at 37 degrees C with 2 mmol L(-1) PCMB. The value of maximal inhibition was approximately 63% when measured at 25 degrees C, approximately 52% at 37 degrees C and approximately 45% at 42 degrees C. The lowest value of P(d) (corresponding to the basal permeability to water) was approximately 3 x 10(-3) cm s(-1) at 25 degrees C. For the RBCs from red-necked wallaby (M. rufogriseus) the values of P(d) (cm s(-1)) were 7 x 10(-3) at 25 degrees C, 8 x 10(-3) at 30 degrees C, 10 x 10(-3) at 37 degrees C, and 12 x 10(-3) at 42 degrees C. Higher values of P(d) (cm s(-1)) were found for the RBCs from Goodfellow's tree kangaroo (D. goodfellowi): 8.5 x 10(-3) at 25 degrees C, 10 x 10(-3) at 30 degrees C, 13 x 10(-3) at 37 degrees C, and 15 x 10(-3) at 42 degrees C. The mean values of the activation energy of water diffusion (E(a,d)) were approximately 25 kJ mol(-1) for RBCs from the agile wallaby and tree kangaroo, respectively, and approximately 23 kJ mol(-1) for RBCs from red-necked wallaby. The values of E(a,d) increased after exposure of agile wallaby RBCs to PCMB, reaching a value of approximately 43-46 kJ mol(-1) when the maximal inhibition of P(d) was achieved.

  17. Cold urticaria with persistent weals.

    PubMed

    Juhlin, L

    1981-06-01

    A patient with cold urticaria is described in whom weals appeared immediately after an ice cube test for 3 min and persisted for a week as a red, tender swelling. The duration of the oedema was dependent on the intensity of the immediate reaction. If the immediate wealing was blocked by treatment with an oral antihistamine 3 h before the ice cube test, no delayed reaction was seen. Antihistamines given after the immediate wealing had occurred did not influence the delayed reaction. Reactions to intradermally injected histamine, prostaglandin E, kallikrein, serotonin and serum appeared normal.

  18. Persistence of random walk records

    NASA Astrophysics Data System (ADS)

    Ben-Naim, E.; Krapivsky, P. L.

    2014-06-01

    We study records generated by Brownian particles in one dimension. Specifically, we investigate an ordinary random walk and define the record as the maximal position of the walk. We compare the record of an individual random walk with the mean record, obtained as an average over infinitely many realizations. We term the walk ‘superior’ if the record is always above average, and conversely, the walk is said to be ‘inferior’ if the record is always below average. We find that the fraction of superior walks, S, decays algebraically with time, S ˜ t-β, in the limit t → ∞, and that the persistence exponent is nontrivial, β = 0.382 258…. The fraction of inferior walks, I, also decays as a power law, I ˜ t-α, but the persistence exponent is smaller, α = 0.241 608…. Both exponents are roots of transcendental equations involving the parabolic cylinder function. To obtain these theoretical results, we analyze the joint density of superior walks with a given record and position, while for inferior walks it suffices to study the density as a function of position.

  19. Persistent ENSO in different climates?

    NASA Astrophysics Data System (ADS)

    Fedorov, A. V.; Manucharyan, G. E.

    2013-12-01

    Growing evidence suggests that, despite profound changes in tropical climate, ENSO has been active over a vast geological epoch stretching millions of years from the Late Cretaceous through the Holocene. In particular, ENSO persisted during the Pliocene when there occurred a dramatic reduction in the mean east-west temperature gradient in the equatorial Pacific - a key element of tropical dynamics. Here we use a comprehensive climate model to explore the dependence of ENSO on this temperature gradient. We find that in a broad range of climates ENSO remains surprisingly robust. When the east-west temperature gradient is reduced from 6oC to 1oC, the amplitude of ENSO decreases only by 30-40%, its dominant period remains close to 3-4 years, and the spectral peak stays above red noise. To explain these results we assess the magnitude of ocean-atmosphere feedbacks that control the stability of the natural mode of ENSO (the Bjerknes Index). We find that due to reorganization of the atmospheric Walker circulation in response to changes in the mean temperature gradient, the growth/decay rates of the ENSO mode stay nearly constant throughout different climates. This factor explains the persistence of the Southern Oscillation in past geological epochs and reconciles the seemingly contradictory findings of ENSO occurrence and the small east-west temperature gradient during the Pliocene. Finally, our results explain why ENSO in many climate models seems to be controlled by a weakly-damped mode just below neutral stability.

  20. Continuation of point clouds via persistence diagrams

    NASA Astrophysics Data System (ADS)

    Gameiro, Marcio; Hiraoka, Yasuaki; Obayashi, Ippei

    2016-11-01

    In this paper, we present a mathematical and algorithmic framework for the continuation of point clouds by persistence diagrams. A key property used in the method is that the persistence map, which assigns a persistence diagram to a point cloud, is differentiable. This allows us to apply the Newton-Raphson continuation method in this setting. Given an original point cloud P, its persistence diagram D, and a target persistence diagram D‧, we gradually move from D to D‧, by successively computing intermediate point clouds until we finally find a point cloud P‧ having D‧ as its persistence diagram. Our method can be applied to a wide variety of situations in topological data analysis where it is necessary to solve an inverse problem, from persistence diagrams to point cloud data.

  1. Persistent Pneumonia in an Infant

    PubMed Central

    Padilla, Kristen; Logan, Latania; Codispoti, Christopher; Jones, Carolyn

    2015-01-01

    A 4-month-old boy with past medical history of eczema presented with fever and cough; a chest radiograph showed lung consolidation, and he was initially treated with amoxicillin for presumed community-acquired pneumonia. After several days, his fever persisted. He was also profoundly anemic. Antibiotic coverage was broadened because of the concern for resistant organisms; he began to improve and was discharged from the hospital. However, at 5 months of age, his fever returned, and he continued to demonstrate lung consolidation on chest radiograph. Additionally, he had lost weight and continued to be anemic. Splenic cysts were noted on abdominal ultrasound. He was diagnosed with an unusual etiology for his pneumonia and improved with the appropriate therapy. An underlying immunodeficiency was suspected, but initial testing was nondiagnostic. At 12 months of age, he presented with another infection, and the final diagnosis was made. PMID:26122810

  2. Long-persistence blue phosphors

    NASA Technical Reports Server (NTRS)

    Yen, William M. (Inventor); Jia, Weiyi (Inventor); Lu, Lizhu (Inventor); Yuan, Huabiao (Inventor)

    2000-01-01

    This invention relates to phosphors including long-persistence blue phosphors. Phosphors of the invention are represented by the general formula: MO . mAl.sub.2 O.sub.3 :Eu.sup.2+,R.sup.3+ wherein m is a number ranging from about 1.6 to about 2.2, M is Sr or a combination of Sr with Ca and Ba or both, R.sup.3+ is a trivalent metal ion or trivalent Bi or a mixture of these trivalent ions, Eu.sup.2+ is present at a level up to about 5 mol % of M, and R.sup.3+ is present at a level up to about 5 mol % of M. Phosphors of this invention include powders, ceramics, single crystals and single crystal fibers. A method of manufacturing improved phosphors and a method of manufacturing single crystal phosphors are also provided.

  3. Persistent nicorandil induced oral ulceration

    PubMed Central

    Healy, C M; Smyth, Y; Flint, S R

    2004-01-01

    Four patients with nicorandil induced ulceration are described, and the literature on the subject is reviewed. Nicorandil induced ulcers are very painful and distressing for patients. Clinically they appear as large, deep, persistent ulcers that have punched out edges. They are poorly responsive to topical steroids and usually require alteration of nicorandil treatment. The ulceration tends to occur at high doses of nicorandil and all four cases reported here were on doses of 40 mg per day or greater. In these situations reduction of nicorandil dose may be sufficient to promote ulcer healing and prevent further recurrence. However, nicorandil induced ulcers have been reported at doses as low as 10 mg daily and complete cessation of nicorandil may be required. PMID:15201264

  4. Persistent Pneumonia in an Infant.

    PubMed

    Padilla, Kristen; Logan, Latania; Codispoti, Christopher; Jones, Carolyn; Van Opstal, Elizabeth

    2015-07-01

    A 4-month-old boy with past medical history of eczema presented with fever and cough; a chest radiograph showed lung consolidation, and he was initially treated with amoxicillin for presumed community-acquired pneumonia. After several days, his fever persisted. He was also profoundly anemic. Antibiotic coverage was broadened because of the concern for resistant organisms; he began to improve and was discharged from the hospital. However, at 5 months of age, his fever returned, and he continued to demonstrate lung consolidation on chest radiograph. Additionally, he had lost weight and continued to be anemic. Splenic cysts were noted on abdominal ultrasound. He was diagnosed with an unusual etiology for his pneumonia and improved with the appropriate therapy. An underlying immunodeficiency was suspected, but initial testing was nondiagnostic. At 12 months of age, he presented with another infection, and the final diagnosis was made.

  5. Dematerialization: Variety, caution, and persistence.

    PubMed

    Ausubel, Jesse H; Waggoner, Paul E

    2008-09-02

    Dematerialization, represented by declining consumption per GDP of energy or of goods, offers some hope for rising environmental quality with development. The declining proportion of income spent on staples as affluence grows, which income elasticity <1.0 measures, makes dematerialization widespread. Further, as learning improves efficiency of resource use, the intensity of environmental impact per production of staples often declines. We observe that combinations of low income elasticity for staples and of learning by producers cause a variety of dematerializations and declining intensities of impact, from energy use and carbon emission to food consumption and fertilizer use, globally and in countries ranging from the United States and France to China, India, Brazil, and Indonesia. Because dematerialization and intensity of impact are ratios of parameters that may be variously defined and are sometimes difficult to estimate, their fluctuations must be interpreted cautiously. Nevertheless, substantial declining intensity of impact, and especially, dematerialization persisted between 1980 and 2006.

  6. Persistent pulmonary hypertension of the neonate (persistent fetal circulation syndrome).

    PubMed

    Drummond, W H

    1983-01-01

    This 15-year-old disease has been clearly described anatomically. Some understanding of possible in utero predisposing conditions has emerged from clinical and animal studies. However, we have very little understanding of the cellular processes that trigger and/or prolong the abnormal medial smooth muscle hypertrophy underlying the condition. Empiric observation has resulted in the development of hyperventilation as a fairly successful treatment modality, although the underlying mechanism of this salubrious effect is unknown. Drugs, a major focus of clinical and laboratory investigations, sometimes are marginally successful (and sometimes are utter failures). Translated into the neonatal intensive care unit, the disease is more frequently accurately diagnosed than in the past, but it remains frustratingly difficult to manage, and thus far is impossible to prevent. The research foundations laid in the past decade provide impetus for accelerated search into the fundamental cellular and biochemical derangements that cause persistent pulmonary hypertension. It is to be hoped that the next decade will yield major advances in both mechanistic understanding and in treatment.

  7. Persistent homology analysis of craze formation

    NASA Astrophysics Data System (ADS)

    Ichinomiya, Takashi; Obayashi, Ippei; Hiraoka, Yasuaki

    2017-01-01

    We apply a persistent homology analysis to investigate the behavior of nanovoids during the crazing process of glassy polymers. We carry out a coarse-grained molecular dynamics simulation of the uniaxial deformation of an amorphous polymer and analyze the results with persistent homology. Persistent homology reveals the void coalescence during craze formation, and the results suggest that the yielding process is regarded as the percolation of nanovoids created by deformation.

  8. Dualities in Persistent (Co)Homology

    SciTech Connect

    de Silva, Vin; Morozov, Dmitriy; Vejdemo-Johansson, Mikael

    2011-09-16

    We consider sequences of absolute and relative homology and cohomology groups that arise naturally for a filtered cell complex. We establishalgebraic relationships between their persistence modules, and show that they contain equivalent information. We explain how one can use the existingalgorithm for persistent homology to process any of the four modules, and relate it to a recently introduced persistent cohomology algorithm. Wepresent experimental evidence for the practical efficiency of the latter algorithm.

  9. Persistence Measures for 2d Soap Froth

    NASA Astrophysics Data System (ADS)

    Feng, Y.; Ruskin, H. J.; Zhu, B.

    Soap froths as typical disordered cellular structures, exhibiting spatial and temporal evolution, have been studied through their distributions and topological properties. Recently, persistence measures, which permit representation of the froth as a two-phase system, have been introduced to study froth dynamics at different length scales. Several aspects of the dynamics may be considered and cluster persistence has been observed through froth experiment. Using a direct simulation method, we have investigated persistent properties in 2D froth both by monitoring the persistence of survivor cells, a topologically independent measure, and in terms of cluster persistence. It appears that the area fraction behavior for both survivor and cluster persistence is similar for Voronoi froth and uniform froth (with defects). Survivor and cluster persistent fractions are also similar for a uniform froth, particularly when geometries are constrained, but differences observed for the Voronoi case appear to be attributable to the strong topological dependency inherent in cluster persistence. Survivor persistence, on the other hand, depends on the number rather than size and position of remaining bubbles and does not exhibit the characteristic decay to zero.

  10. Persistant photoconductivity of strontium titanate

    NASA Astrophysics Data System (ADS)

    Poole, Violet Mary

    Strontium titanate (SrTiO3) is a transparent conducting oxide with a range of interesting properties, including a large, temperature-dependent dielectric constant and superconductivity at low temperatures. It has a wide indirect band gap of 3.2 eV at room temperature. Annealing in a reducing atmosphere with additional strontium oxide (SrO) powder at 1200°C results in the creation of native defects. These annealed samples show persistent photoconductivity (PPC) at room temperature, when exposed to light of energy 2.9 eV or greater. The three or more order of magnitude change in resistance persists long after the light is turned off. This effect is attributed to an electron being excited from an acceptor defect, with a large barrier for recapture, to the conduction band. This work investigates many of the changes that occur and factors that affect PPC. The right amount of SrO powder is crucial to the formation of PPC. The presence of some oxygen vacancies is also necessary for PPC; however, too many will mute the dramatic change in resistivity. Peaks at 430 nm and 520 nm appear in the visible region of the spectrum. The peak at 430 nm is due to iron, while the peak at 520 nm has not been identified. The infrared region of the spectrum also shows changes. First, the intensity of the transmitted signal drops significantly after light exposure, due to free carrier absorption. Additionally, a hydrogen line at 3500 cm-1 and satellites are often observed in as-received samples. The satellites disappear during annealing and return during PPC. The hydrogen lines have the same thermal kinetics as the 520 nm peak. Hydrogen lines at 3355 and 3384 cm-1, if present, will prevent PPC. An exposed chip can be erased (i.e. returned to its pre-light exposed state) by using a heat treatment. Erasing and polishing an annealed chip prior to light exposure can result in weakly p-type behavior with high mobility holes ( > 100 cm2/Vs). This is an order of magnitude higher than those

  11. A PILOT STUDY OF CHILDREN'S TOTAL EXPOSURE TO PERSISTENT PESTICIDES AND OTHER PERSISTENT ORGANIC POLLUTANTS (CTEPP)

    EPA Science Inventory

    The Pilot Study of Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) investigated the aggregate exposures of 257 preschool children and their primary adult caregivers to pollutants commonly detected in their everyday environments. ...

  12. Graduate Student Persistence: Evidence from Three Decades

    ERIC Educational Resources Information Center

    Gururaj, Suchitra; Heilig, Julian Vasquez; Somers, Patricia

    2010-01-01

    This article conducts a meta-analysis of results of studies by Andrieu (1991), DeAngelis (1998), and Liseo (2005) to assess changes over time in the effects of financial aid and other factors on graduate student persistence. A descriptive review of the studies finds that combination aid packages encouraged persistence in 1987 (Andrieu, 1991),…

  13. Correlated neural variability in persistent state networks.

    PubMed

    Polk, Amber; Litwin-Kumar, Ashok; Doiron, Brent

    2012-04-17

    Neural activity that persists long after stimulus presentation is a biological correlate of short-term memory. Variability in spiking activity causes persistent states to drift over time, ultimately degrading memory. Models of short-term memory often assume that the input fluctuations to neural populations are independent across cells, a feature that attenuates population-level variability and stabilizes persistent activity. However, this assumption is at odds with experimental recordings from pairs of cortical neurons showing that both the input currents and output spike trains are correlated. It remains unclear how correlated variability affects the stability of persistent activity and the performance of cognitive tasks that it supports. We consider the stochastic long-timescale attractor dynamics of pairs of mutually inhibitory populations of spiking neurons. In these networks, persistent activity was less variable when correlated variability was globally distributed across both populations compared with the case when correlations were locally distributed only within each population. Using a reduced firing rate model with a continuum of persistent states, we show that, when input fluctuations are correlated across both populations, they drive firing rate fluctuations orthogonal to the persistent state attractor, thereby causing minimal stochastic drift. Using these insights, we establish that distributing correlated fluctuations globally as opposed to locally improves network's performance on a two-interval, delayed response discrimination task. Our work shows that the correlation structure of input fluctuations to a network is an important factor when determining long-timescale, persistent population spiking activity.

  14. Long Persistent Light Emitting Diode Indicators

    ERIC Educational Resources Information Center

    Jia, Dongdong; Ma, Yiwei; Hunter, D. N.

    2007-01-01

    An undergraduate laboratory was designed for undergraduate students to make long persistent light emitting diode (LED) indicators using phosphors. Blue LEDs, which emit at 465 nm, were characterized and used as an excitation source. Long persistent phosphors, SrAl[subscript 2]O[subscript 4]:Eu[superscript 2+],Dy[superscript 3+] (green) and…

  15. Persistence of Undergraduate Women in STEM Fields

    ERIC Educational Resources Information Center

    Pedone, Maggie Helene

    2016-01-01

    The underrepresentation of women in science, technology, engineering, and mathematics (STEM) is a complex problem that continues to persist at the postsecondary level, particularly in computer science and engineering fields. This dissertation explored the pre-college and college level factors that influenced undergraduate women's persistence in…

  16. STEM Field Persistence: The Impact of Engagement on Postsecondary STEM Persistence for Underrepresented Minority Students

    ERIC Educational Resources Information Center

    Flynn, Daniel T.

    2016-01-01

    Persistence studies in science, technology, engineering, and math (STEM) fields indicate that the pipeline to degree attainment is "leaky" and underrepresented minorities are not persisting in the STEM fields. Those students who do not persist in the STEM fields either migrate to other fields of study or drop out of higher education…

  17. Pretreatment task persistence predicts smoking cessation outcome.

    PubMed

    Brandon, Thomas H; Herzog, Thaddeus A; Juliano, Laura M; Irvin, Jennifer E; Lazev, Amy B; Simmons, Vani Nath

    2003-08-01

    R. Eisenberger's (1992) learned industriousness theory states that individuals display differing degrees of persistence depending on their history of reinforcement for effortful behavior. These differences may influence the development, maintenance, and cessation of addictive behaviors. In cross-sectional studies, E. P. Quinn, T. H. Brandon, and A. L. Copeland (1996) found that cigarette smokers were less persistent than nonsmokers, and R. A. Brown, C. W. Lejuez, C. W. Kahler, and D. R. Strong (2002) found that smokers who had previously abstained for 3 months were more persistent than those who had never quit. The present study extended these findings by using a prospective design. A pretreatment measure of task persistence (mirror tracing) completed by 144 smokers predicted sustained abstinence throughout 12 months of follow-up. Moreover, persistence predicted outcome independent of other significant predictors: gender, nicotine dependence, negative affect, and self-efficacy.

  18. Atypical persistence of tunica vasculosa lentis.

    PubMed

    Kumar, Ashima V; Chhabra, Manpreet S; Mets, Marilyn B

    2008-01-01

    The authors report an unusual case of persistent tunica vasculosa lentis in a patient with minimal retinopathy of prematurity (ROP). A 3-month-old male infant who had been born at 31 weeks' gestation presented with a significant amount of persistent tunica vasculosa lentis and arteriolar tortuosity with minimal ROP and no plus disease. After weekly observation and no surgical intervention, the arteriolar tortuosity lessened but the tunica vasculosa lentis persisted. Persistent tunica vasculosa lentis can be mistaken for iris vascular engorgement, suggesting plus disease and high-risk prethreshold ROP. Differentiation between tunica vasculosa lentis and iris vascular engorgement, as well as correct diagnosis of plus disease, is critical when considering laser treatment for high-risk prethreshold ROP.

  19. The persistent stereotype: children's images of scientists

    NASA Astrophysics Data System (ADS)

    Emens McAdam, Janice

    1990-03-01

    Through their reading children learn to regard scientists as eccentrics. It is shown that this stereotype has persisted for over thirty years and affects many adult attitudes. Some methods of breaking the author-reader cycle are suggested.

  20. Stimuli, Reinforcers, and the Persistence of Behavior

    ERIC Educational Resources Information Center

    Nevin, John A.

    2009-01-01

    This article reviews evidence from basic and translational research with pigeons and humans suggesting that the persistence of operant behavior depends on the contingency between stimuli and reinforcers, and considers some implications for clinical interventions. (Contains 4 figures.)

  1. [Persistent dento-alveolar pain disorder (PDAP)].

    PubMed

    Warnsinck, C J; Koutris, M; Shemesh, H; Lobbezoo, F

    2015-02-01

    Dento-alveolar pain is common in the orofacial area. Persistent dento-alveolar pain could be experienced without an identifiable etiology with poor response to existing treatments. Confusion about the diagnosis and classification of persistent dento-alveolar pain (PDAP) disorders could explain the difficulties in treatment and unfavorable prognosis. Recently, initial steps were made to improve the taxonomy and diagnostic criteria for PDAP in order to improve clinical research and care.

  2. Wolf population persistence in real life

    USGS Publications Warehouse

    Mech, L.D.; Liberg, O.

    2005-01-01

    Wolf (Canis lupus) populations tend to be resilient and to persist for long periods, and several characteristics contribute to their resilience and persistence: (1) age of first reproduction (2-3 years), (2) high annual litter size (mean = 6), (3) low dispersal age (1-3 years), and (4) long potential dispersal distance (< 880 km). The only documented factor leading to extinction of well established wolf populations with sufficient food is deliberate poisoning, although conceivably disease could have such an effect.

  3. Persistent homology analysis of phase transitions.

    PubMed

    Donato, Irene; Gori, Matteo; Pettini, Marco; Petri, Giovanni; De Nigris, Sarah; Franzosi, Roberto; Vaccarino, Francesco

    2016-05-01

    Persistent homology analysis, a recently developed computational method in algebraic topology, is applied to the study of the phase transitions undergone by the so-called mean-field XY model and by the ϕ^{4} lattice model, respectively. For both models the relationship between phase transitions and the topological properties of certain submanifolds of configuration space are exactly known. It turns out that these a priori known facts are clearly retrieved by persistent homology analysis of dynamically sampled submanifolds of configuration space.

  4. Persistence of the Lower Stratospheric Polar Vortices

    NASA Technical Reports Server (NTRS)

    Waugh, Darryn W.; Randel, William J.; Pawson, Steven; Newman, Paul A.; Nash, Eric R.

    1999-01-01

    The persistence of the Arctic and Antarctic lower stratospheric vortices is examined over the period 1958 to 1998. Three different vortex-following diagnostics (two using potential vorticity and one based solely on the zonal winds) are compared, and shown to give very similar results for the break up date. The variability in the timing of the breakup of each vortex is qualitatively the same: there are large interannual variations together with smaller decadal-scale variations and there is a significant increase in the persistence since the mid-1980s (all variations are larger for the Arctic vortex). Also, in both hemispheres there is a high correlation between the persistence and the strength and coldness of the spring vortex, with all quantities having the same interannual and decadal variability. However, there is no such correlation between the persistence and the characteristics of the mid-winter vortex. In the northern hemisphere there is also a high correlation between the vortex persistence and the upper tropospheric/lower stratospheric eddy heat flux averaged over the two months prior to the breakup. This indicates that the variability in the wave activity entering the stratosphere over late-winter to early-spring plays a key role in the variability of the vortex persistence (and spring polar temperatures) on both interannual and decadal time scales. However, the decadal variation in the Arctic vortex coldness and persistence for the 1990's falls outside the range of natural variability, while this is not the case for the eddy heat flux. This suggests that the recent increase in vortex persistence is not due solely to changes in the wave activity entering the stratosphere.

  5. [Therapeutic approach in persistent diabetic macular edema].

    PubMed

    Brănişteanu, Daniel; Moraru, Andreea

    2014-01-01

    Terminology of persistent diabetic macular edema has been initially reserved to cases unresponsive to conventional laser photocoagulation according to ETDRS criteria. While knowledge about pathophysiology of macular edema evolved and new drugs became available, the terminology of persistent diabetic macular edema expanded to include resistance to most current therapies. The purpose of this paper is to review medical and surgical options in the treatment of such difficult cases according to literature data and personal experience.

  6. Persistent homology in graph power filtrations

    PubMed Central

    Marchette, David J.

    2016-01-01

    The persistence of homological features in simplicial complex representations of big datasets in Rn resulting from Vietoris–Rips or Čech filtrations is commonly used to probe the topological structure of such datasets. In this paper, the notion of homological persistence in simplicial complexes obtained from power filtrations of graphs is introduced. Specifically, the rth complex, r ≥ 1, in such a power filtration is the clique complex of the rth power Gr of a simple graph G. Because the graph distance in G is the relevant proximity parameter, unlike a Euclidean filtration of a dataset where regional scale differences can be an issue, persistence in power filtrations provides a scale-free insight into the topology of G. It is shown that for a power filtration of G, the girth of G defines an r range over which the homology of the complexes in the filtration are guaranteed to persist in all dimensions. The role of chordal graphs as trivial homology delimiters in power filtrations is also discussed and the related notions of ‘persistent triviality’, ‘transient noise’ and ‘persistent periodicity’ in power filtrations are introduced. PMID:27853540

  7. Damage and repair in mammalian cells after exposure to non-ionizing radiations. II. Photoreactivation and killing of rat kangaroo cells (Potorous tridactylus) and Herpes simplex virus-1 by exposure to fluorescent "white" light or sunlight.

    PubMed

    Harm, H

    1980-01-01

    Photoreactivation (PR) of ultraviolet (254 nm)-inactivated cornea cells of the potoroo (or rat kangaroo; Potorous tridacylus) has been studied at wavelengths greater than 375 nm from either fluorescent "white" light or sunlight. In both cases the PR kinetics curves pass through maxima, which most likely result from the superposition of concomitant inactivation by the photoreactivating light. The inactivating effect of light was directly demonstrated for non-UV-irradiated cells, permitting correction of the PR curves. Wavelengths greater than 475 nm, and even greater than 560 nm, which do not noticeably damage cells, still photoreactivate, though less effectively than shorter wavelengths. Light treatment of UV-inactivated Herpes simplex Virus-1 (HSV-1) after infection leads to PR effects resembling those observed for cells, while light treatment of unirradiated virus after infection likewise causes inactivation. The "fluence-reduction factor" of PR, which is greater than 3 for the virus, exceeds that for the cells, where it decreases with increasing UV fluence. In vitro tests have indicated that sunlight greater than 375 nm causes photorepairable DNA lesions which are virtually fully repaired by the same light. Thus cell inactivation resulting from these solar wavelengths must be due to non-photorepairable damage.

  8. Herbicide Persistence in Seawater Simulation Experiments.

    PubMed

    Mercurio, Philip; Mueller, Jochen F; Eaglesham, Geoff; Flores, Florita; Negri, Andrew P

    2015-01-01

    Herbicides are detected year-round in marine waters, including those of the World Heritage listed Great Barrier Reef (GBR). The few previous studies that have investigated herbicide persistence in seawater generally reported half-lives in the order of months, and several studies were too short to detect significant degradation. Here we investigated the persistence of eight herbicides commonly detected in the GBR or its catchments in standard OECD simulation flask experiments, but with the aim to mimic natural conditions similar to those found on the GBR (i.e., relatively low herbicide concentrations, typical temperatures, light and microbial communities). Very little degradation was recorded over the standard 60 d period (Experiment 1) so a second experiment was extended to 365 d. Half-lives of PSII herbicides ametryn, atrazine, diuron, hexazinone and tebuthiuron were consistently greater than a year, indicating high persistence. The detection of atrazine and diuron metabolites and longer persistence in mercuric chloride-treated seawater confirmed that biodegradation contributed to the breakdown of herbicides. The shortest half-life recorded was 88 d for growth-regulating herbicide 2,4-D at 31°C in the dark, while the fatty acid-inhibitor metolachlor exhibited a minimum half-life of 281 d. The presence of moderate light and elevated temperatures affected the persistence of most of the herbicides; however, the scale and direction of the differences were not predictable and were likely due to changes in microbial community composition. The persistence estimates here represent some of the first appropriate data for application in risk assessments for herbicide exposure in tropical marine systems. The long persistence of herbicides identified in the present study helps explain detection of herbicides in nearshore waters of the GBR year round. Little degradation of these herbicides would be expected during the wet season with runoff and associated flood plumes

  9. Sequence-Dependent Persistence Lengths of DNA.

    PubMed

    Mitchell, Jonathan S; Glowacki, Jaroslaw; Grandchamp, Alexandre E; Manning, Robert S; Maddocks, John H

    2017-03-24

    A Monte Carlo code applied to the cgDNA coarse-grain rigid-base model of B-form double-stranded DNA is used to predict a sequence-averaged persistence length of lF = 53.5 nm in the sense of Flory, and of lp = 160 bp or 53.5 nm in the sense of apparent tangent-tangent correlation decay. These estimates are slightly higher than the consensus experimental values of 150 bp or 50 nm, but we believe the agreement to be good given that the cgDNA model is itself parametrized from molecular dynamics simulations of short fragments of length 10-20 bp, with no explicit fit to persistence length. Our Monte Carlo simulations further predict that there can be substantial dependence of persistence lengths on the specific sequence [Formula: see text] of a fragment. We propose, and confirm the numerical accuracy of, a simple factorization that separates the part of the apparent tangent-tangent correlation decay [Formula: see text] attributable to intrinsic shape, from a part [Formula: see text] attributable purely to stiffness, i.e., a sequence-dependent version of what has been called sequence-averaged dynamic persistence length l̅d (=58.8 nm within the cgDNA model). For ensembles of both random and λ-phage fragments, the apparent persistence length [Formula: see text] has a standard deviation of 4 nm over sequence, whereas our dynamic persistence length [Formula: see text] has a standard deviation of only 1 nm. However, there are notable dynamic persistence length outliers, including poly(A) (exceptionally straight and stiff), poly(TA) (tightly coiled and exceptionally soft), and phased A-tract sequence motifs (exceptionally bent and stiff). The results of our numerical simulations agree reasonably well with both molecular dynamics simulation and diverse experimental data including minicircle cyclization rates and stereo cryo-electron microscopy images.

  10. Emergence of Persistent Infection due to Heterogeneity

    NASA Astrophysics Data System (ADS)

    Agrawal, Vidit; Moitra, Promit; Sinha, Sudeshna

    2017-02-01

    We explore the emergence of persistent infection in a closed region where the disease progression of the individuals is given by the SIRS model, with an individual becoming infected on contact with another infected individual. We investigate the persistence of contagion qualitatively and quantitatively, under increasing heterogeneity in the partitioning of the population into different disease compartments, as well as increasing heterogeneity in the phases of the disease among individuals within a compartment. We observe that when the initial population is uniform, consisting of individuals at the same stage of disease progression, infection arising from a contagious seed does not persist. However when the initial population consists of randomly distributed refractory and susceptible individuals, a single source of infection can lead to sustained infection in the population, as heterogeneity facilitates the de-synchronization of the phases in the disease cycle of the individuals. We also show how the average size of the window of persistence of infection depends on the degree of heterogeneity in the initial composition of the population. In particular, we show that the infection eventually dies out when the entire initial population is susceptible, while even a few susceptibles among an heterogeneous refractory population gives rise to a large persistent infected set.

  11. Persistent agents in Axelrod's social dynamics model

    NASA Astrophysics Data System (ADS)

    Reia, Sandro M.; Neves, Ubiraci P. C.

    2016-01-01

    Axelrod's model of social dynamics has been studied under the effect of external media. Here we study the formation of cultural domains in the model by introducing persistent agents. These are agents whose cultural traits are not allowed to change but may be spread through local neighborhood. In the absence of persistent agents, the system is known to present a transition from a monocultural to a multicultural regime at some critical Q (number of traits). Our results reveal a dependence of critical Q on the occupation probability p of persistent agents and we obtain the phase diagram of the model in the (p,Q) -plane. The critical locus is explained by the competition of two opposite forces named here barrier and bonding effects. Such forces are verified to be caused by non-persistent agents which adhere (adherent agents) to the set of traits of persistent ones. The adherence (concentration of adherent agents) as a function of p is found to decay for constant Q. Furthermore, adherence as a function of Q is found to decay as a power law with constant p.

  12. Emergence of Persistent Infection due to Heterogeneity

    PubMed Central

    Agrawal, Vidit; Moitra, Promit; Sinha, Sudeshna

    2017-01-01

    We explore the emergence of persistent infection in a closed region where the disease progression of the individuals is given by the SIRS model, with an individual becoming infected on contact with another infected individual. We investigate the persistence of contagion qualitatively and quantitatively, under increasing heterogeneity in the partitioning of the population into different disease compartments, as well as increasing heterogeneity in the phases of the disease among individuals within a compartment. We observe that when the initial population is uniform, consisting of individuals at the same stage of disease progression, infection arising from a contagious seed does not persist. However when the initial population consists of randomly distributed refractory and susceptible individuals, a single source of infection can lead to sustained infection in the population, as heterogeneity facilitates the de-synchronization of the phases in the disease cycle of the individuals. We also show how the average size of the window of persistence of infection depends on the degree of heterogeneity in the initial composition of the population. In particular, we show that the infection eventually dies out when the entire initial population is susceptible, while even a few susceptibles among an heterogeneous refractory population gives rise to a large persistent infected set. PMID:28145522

  13. Persistent Structures in the Turbulent Boundary Layer

    NASA Technical Reports Server (NTRS)

    Palumbo, Dan; Chabalko, Chris

    2005-01-01

    Persistent structures in the turbulent boundary layer are located and analyzed. The data are taken from flight experiments on large commercial aircraft. An interval correlation technique is introduced which is able to locate the structures. The Morlet continuous wavelet is shown to not only locates persistent structures but has the added benefit that the pressure data are decomposed in time and frequency. To better understand how power is apportioned among these structures, a discrete Coiflet wavelet is used to decompose the pressure data into orthogonal frequency bands. Results indicate that some structures persist a great deal longer in the TBL than would be expected. These structure contain significant power and may be a primary source of vibration energy in the airframe.

  14. Improving Underrepresented Minority Student Persistence in STEM.

    PubMed

    Estrada, Mica; Burnett, Myra; Campbell, Andrew G; Campbell, Patricia B; Denetclaw, Wilfred F; Gutiérrez, Carlos G; Hurtado, Sylvia; John, Gilbert H; Matsui, John; McGee, Richard; Okpodu, Camellia Moses; Robinson, T Joan; Summers, Michael F; Werner-Washburne, Maggie; Zavala, MariaElena

    2016-01-01

    Members of the Joint Working Group on Improving Underrepresented Minorities (URMs) Persistence in Science, Technology, Engineering, and Mathematics (STEM)-convened by the National Institute of General Medical Sciences and the Howard Hughes Medical Institute-review current data and propose deliberation about why the academic "pathways" leak more for URM than white or Asian STEM students. They suggest expanding to include a stronger focus on the institutional barriers that need to be removed and the types of interventions that "lift" students' interests, commitment, and ability to persist in STEM fields. Using Kurt Lewin's planned approach to change, the committee describes five recommendations to increase URM persistence in STEM at the undergraduate level. These recommendations capitalize on known successes, recognize the need for accountability, and are framed to facilitate greater progress in the future. The impact of these recommendations rests upon enacting the first recommendation: to track successes and failures at the institutional level and collect data that help explain the existing trends.

  15. Persistent toxic substances: sources, fates and effects.

    PubMed

    Wong, Ming H; Armour, Margaret-Ann; Naidu, Ravi; Man, Ming

    2012-01-01

    Persistent toxic substances (PTS) include the Stockholm persistent organic pollutants, like dichlorodiphenyltrichloroethane, polychlorinated biphenyls, dioxin/furan, etc., and organometallic compounds, like organomercury, organotin, and organolead, which all share the same characteristics of being persistent, toxic, bioaccumulative, and able to travel long distances through different media. The adverse health effects of some of the emerging chemicals like pentabromodiphenyl ether, bisphenol A, and di(2-ethylhexyl)phthalate, which are widely used in daily appliances (e.g., TVs, computers, mobile phones, plastic baby bottles), have become a public health concern due to more evidence now available showing their adverse effects like disturbance of the endocrine system and cancer. This article is an attempt to review the current status of PTS in our environment, citing case studies in China and North America, and whether our existing drinking water treatment and wastewater treatment processes are adequate in removing them from water. Some management issues of these emerging chemicals of concern are also discussed.

  16. Persistent currents in mesoscopic Fibonacci rings

    SciTech Connect

    Jin, G.J.; Wang, Z.D.; Hu, A.; Jiang, S.S.

    1997-04-01

    In the framework of a tight-binding model, we study energy spectra and persistent currents in mesoscopic Fibonacci rings threaded by a magnetic flux. It is found that the flux-dependent electron eigenenergies E({Phi}) in mesoscopic Fibonacci rings still form ``bands`` with respect to the flux {Phi}, but there is a scaling relation between the total ``bandwidth`` and the Fibonacci number. When the strength of the one-dimensional quasiperiodic potential increases, the persistent current decreases rapidly. Interestingly, for a generalized mixing model of mesoscopic Fibonacci rings, free-electron-like persistent current may appear if the number of electrons of the system takes a specific value. {copyright} {ital 1997} {ital The American Physical Society}

  17. The origins of lactase persistence in Europe.

    PubMed

    Itan, Yuval; Powell, Adam; Beaumont, Mark A; Burger, Joachim; Thomas, Mark G

    2009-08-01

    Lactase persistence (LP) is common among people of European ancestry, but with the exception of some African, Middle Eastern and southern Asian groups, is rare or absent elsewhere in the world. Lactase gene haplotype conservation around a polymorphism strongly associated with LP in Europeans (-13,910 C/T) indicates that the derived allele is recent in origin and has been subject to strong positive selection. Furthermore, ancient DNA work has shown that the--13,910*T (derived) allele was very rare or absent in early Neolithic central Europeans. It is unlikely that LP would provide a selective advantage without a supply of fresh milk, and this has lead to a gene-culture coevolutionary model where lactase persistence is only favoured in cultures practicing dairying, and dairying is more favoured in lactase persistent populations. We have developed a flexible demic computer simulation model to explore the spread of lactase persistence, dairying, other subsistence practices and unlinked genetic markers in Europe and western Asia's geographic space. Using data on--13,910*T allele frequency and farming arrival dates across Europe, and approximate Bayesian computation to estimate parameters of interest, we infer that the--13,910*T allele first underwent selection among dairying farmers around 7,500 years ago in a region between the central Balkans and central Europe, possibly in association with the dissemination of the Neolithic Linearbandkeramik culture over Central Europe. Furthermore, our results suggest that natural selection favouring a lactase persistence allele was not higher in northern latitudes through an increased requirement for dietary vitamin D. Our results provide a coherent and spatially explicit picture of the coevolution of lactase persistence and dairying in Europe.

  18. Amnestically Induced Persistence in Random Walks

    NASA Astrophysics Data System (ADS)

    Cressoni, J. C.; da Silva, Marco Antonio Alves; Viswanathan, G. M.

    2007-02-01

    We study how the Hurst exponent α depends on the fraction f of the total time t remembered by non-Markovian random walkers that recall only the distant past. We find that otherwise nonpersistent random walkers switch to persistent behavior when inflicted with significant memory loss. Such memory losses induce the probability density function of the walker’s position to undergo a transition from Gaussian to non-Gaussian. We interpret these findings of persistence in terms of a breakdown of self-regulation mechanisms and discuss their possible relevance to some of the burdensome behavioral and psychological symptoms of Alzheimer’s disease and other dementias.

  19. Platforms for Persistent Communications, Surveillance and Reconnaissance

    DTIC Science & Technology

    2008-09-01

    GPS Geosynchronous Orbit (GEO) – e.g.,DSCS/ UFO / INMARSAT Grading Factors (1–4 shown as colors) Sensitivity Analysis Observations Notes: 10Persistent...SWaP/Manpack Not Voice Capable Voice Capable Image Capable Video Capable Acquisition Cost > $50M $10M – $50M $1M – $10M < $1M Flying Hr Cost > $20K $5K...GPS Geosynchronous Orbit (GEO) – e.g.,DSCS/ UFO / INMARSAT Grading Factors (1–4 shown as colors) Sensitivity Analysis Observations Notes: 12Persistent

  20. Chronic Bacterial Pathogens: Mechanisms of Persistence

    PubMed Central

    Byndloss, Mariana X.; Tsolis, Renee M

    2015-01-01

    Summary Many bacterial pathogens can cause acute infections that are cleared with onset of adaptive immunity, however a subset of these pathogens can establish persistent, and sometimes lifelong infections. While bacteria causing chronic infections are phylogenetically diverse, they share common features in their interactions with the host that enable a protracted period of colonization. This chapter will compare the persistence strategies of two chronic pathogens from the Proteobacteria, Brucella abortus, and Salmonella enterica serovar Typhi (S. Typhi) to consider how these two pathogens, which are very different at the genomic level, can utilize common strategies to evade immune clearance to cause chronic intracellular infections of the mononuclear phagocyte system. PMID:27227304

  1. Screening chemicals for persistence in the environment

    SciTech Connect

    Gouin, T.; MacKay, D.; Webster, E.; Wania, F.

    2000-03-01

    A method is suggested for rapid screening of chemicals for persistence in the environment. Physical-chemical equilibrium partitioning information between air, water, and octanol are used as a first screen to identify the media for which degradation half-lives are required and those for which half-lives may be unnecessary. An overall persistence under equilibrium conditions is then estimated using half-lives in air, water, soil, and sediment using a steady-state mass balance model. A graphical technique to identify the key half-lives is demonstrated using 233 chemicals. For chemicals of more extreme partitioning properties, some half-lives may not be needed.

  2. Long persistence effects of geomagnetic activity

    NASA Astrophysics Data System (ADS)

    Wrenn, Gordon L.

    1990-03-01

    The identification of the physical processes which perturb the dynamic equilibrium of the charged particle populations in the terrestrial magnetosphere is investigated. A planetary index was used and it was proved that the introduction of a persistence factor for a derived index, a time weighted accumulation of recent values, gives a better correlation with an estimation of characteristic persistence times in order to establish the temporal response of observed effects in relation to available measures of geomagnetic activity. The analysis procedure was illustrated by results pertaining to ionospheric foF2, cold plasma concentration at geosynchronous orbit and ring current strength.

  3. Persistent and refractory thrush with unknown cause.

    PubMed

    Wang, Lili; Liu, Dongjuan; Zhao, Xin; Wu, Lanyan; Zhou, Yu; Chen, Qianming; Zeng, Xin; Jin, Xin

    2015-03-01

    Oral thrush is considered as the opportunistic infection, which is caused by fungus Candida albicans. Various kinds of immunodeficiency diseases, such as HIV infection, immunosuppressive therapy, use of broad-spectrum antibiotics, and invasive surgical procedures such as solid organ or bone marrow transplantation, lead to increased susceptibility to fungal infections, but persistent and refractory thrush, with typical clinical signs of oral fungal infection and without any other sign of immunodeficiencies, has not been reported so far. We describe a case of persistent and refractory thrush with Klinefelter syndrome (47, XXY) as the unusual cause.

  4. Amnestically induced persistence in random walks.

    PubMed

    Cressoni, J C; da Silva, Marco Antonio Alves; Viswanathan, G M

    2007-02-16

    We study how the Hurst exponent alpha depends on the fraction f of the total time t remembered by non-Markovian random walkers that recall only the distant past. We find that otherwise nonpersistent random walkers switch to persistent behavior when inflicted with significant memory loss. Such memory losses induce the probability density function of the walker's position to undergo a transition from Gaussian to non-Gaussian. We interpret these findings of persistence in terms of a breakdown of self-regulation mechanisms and discuss their possible relevance to some of the burdensome behavioral and psychological symptoms of Alzheimer's disease and other dementias.

  5. Persistent ion beam induced conductivity in zinc oxide nanowires

    SciTech Connect

    Johannes, Andreas; Niepelt, Raphael; Gnauck, Martin; Ronning, Carsten

    2011-12-19

    We report persistently increased conduction in ZnO nanowires irradiated by ion beam with various ion energies and species. This effect is shown to be related to the already known persistent photo conduction in ZnO and dubbed persistent ion beam induced conduction. Both effects show similar excitation efficiency, decay rates, and chemical sensitivity. Persistent ion beam induced conduction will potentially allow countable (i.e., single dopant) implantation in ZnO nanostructures and other materials showing persistent photo conduction.

  6. Persistent ion beam induced conductivity in zinc oxide nanowires

    NASA Astrophysics Data System (ADS)

    Johannes, Andreas; Niepelt, Raphael; Gnauck, Martin; Ronning, Carsten

    2011-12-01

    We report persistently increased conduction in ZnO nanowires irradiated by ion beam with various ion energies and species. This effect is shown to be related to the already known persistent photo conduction in ZnO and dubbed persistent ion beam induced conduction. Both effects show similar excitation efficiency, decay rates, and chemical sensitivity. Persistent ion beam induced conduction will potentially allow countable (i.e., single dopant) implantation in ZnO nanostructures and other materials showing persistent photo conduction.

  7. Persistence of Value-Driven Attentional Capture

    ERIC Educational Resources Information Center

    Anderson, Brian A.; Yantis, Steven

    2013-01-01

    Stimuli that have previously been associated with the delivery of reward involuntarily capture attention when presented as unrewarded and task-irrelevant distractors in a subsequent visual search task. It is unknown how long such effects of reward learning on attention persist. One possibility is that value-driven attentional biases are plastic…

  8. Persistence in eye movement during visual search

    NASA Astrophysics Data System (ADS)

    Amor, Tatiana A.; Reis, Saulo D. S.; Campos, Daniel; Herrmann, Hans J.; Andrade, José S.

    2016-02-01

    As any cognitive task, visual search involves a number of underlying processes that cannot be directly observed and measured. In this way, the movement of the eyes certainly represents the most explicit and closest connection we can get to the inner mechanisms governing this cognitive activity. Here we show that the process of eye movement during visual search, consisting of sequences of fixations intercalated by saccades, exhibits distinctive persistent behaviors. Initially, by focusing on saccadic directions and intersaccadic angles, we disclose that the probability distributions of these measures show a clear preference of participants towards a reading-like mechanism (geometrical persistence), whose features and potential advantages for searching/foraging are discussed. We then perform a Multifractal Detrended Fluctuation Analysis (MF-DFA) over the time series of jump magnitudes in the eye trajectory and find that it exhibits a typical multifractal behavior arising from the sequential combination of saccades and fixations. By inspecting the time series composed of only fixational movements, our results reveal instead a monofractal behavior with a Hurst exponent , which indicates the presence of long-range power-law positive correlations (statistical persistence). We expect that our methodological approach can be adopted as a way to understand persistence and strategy-planning during visual search.

  9. Inchworm, Inchworm: Persistent Problems in Reading Education.

    ERIC Educational Resources Information Center

    McCullough, Constance M., Ed.

    The papers in this volume represent thoughts about the state of the art of teaching reading (with an emphasis on persistent problems) of many recognized authorities in the field of reading education. Eight of the articles were originally presented at a joint Reading Hall of Fame and International Reading Association (IRA) symposium at the IRA…

  10. Registered Nurse Persistence in Baccalaureate Education

    ERIC Educational Resources Information Center

    Krov, Kathleen Nadler

    2010-01-01

    There is a need to increase the number of baccalaureate prepared registered nurses to safely meet the complex healthcare needs of citizens of the United States. Since there is no research on the characteristics of registered nurse students persisting in baccalaureate education, this quantitative descriptive case study was designed to identify the…

  11. High School Economic Composition and College Persistence.

    PubMed

    Niu, Sunny X; Tienda, Marta

    2013-02-01

    Using a longitudinal sample of Texas high school seniors of 2002 who enrolled in college within the calendar year of high school graduation, we examine variation in college persistence according to the economic composition of their high schools, which serves as a proxy for unmeasured high school attributes that are conductive to postsecondary success. Students who graduated from affluent high schools have the highest persistence rates and those who attended poor high schools have the lowest rates. Multivariate analyses indicate that the advantages in persistence and on-time graduation from four-year colleges enjoyed by graduates of affluent high schools cannot be fully explained by high school college orientation and academic rigor, family background, pre-college academic preparedness or the institutional characteristics. High school college orientation, family background and pre-college academic preparation largely explain why graduates from affluent high schools who first enroll in two-year colleges have higher transfer rates to four-year institutions; however these factors and college characteristics do not explain the lower transfer rates for students from poor high schools. The conclusion discusses the implications of the empirical findings in light of several recent studies that call attention to the policy importance of high schools as a lever to improve persistence and completion rates via better institutional matches.

  12. High School Economic Composition and College Persistence

    PubMed Central

    Tienda, Marta

    2013-01-01

    Using a longitudinal sample of Texas high school seniors of 2002 who enrolled in college within the calendar year of high school graduation, we examine variation in college persistence according to the economic composition of their high schools, which serves as a proxy for unmeasured high school attributes that are conductive to postsecondary success. Students who graduated from affluent high schools have the highest persistence rates and those who attended poor high schools have the lowest rates. Multivariate analyses indicate that the advantages in persistence and on-time graduation from four-year colleges enjoyed by graduates of affluent high schools cannot be fully explained by high school college orientation and academic rigor, family background, pre-college academic preparedness or the institutional characteristics. High school college orientation, family background and pre-college academic preparation largely explain why graduates from affluent high schools who first enroll in two-year colleges have higher transfer rates to four-year institutions; however these factors and college characteristics do not explain the lower transfer rates for students from poor high schools. The conclusion discusses the implications of the empirical findings in light of several recent studies that call attention to the policy importance of high schools as a lever to improve persistence and completion rates via better institutional matches. PMID:23459198

  13. RISK CHARACTERIZATION OF PERSISTENT NEUROTOXIC CONTAMINANTS

    EPA Science Inventory

    Neurotoxicity is an adverse change in structure or function of the central and/or peripheral nervous system following exposure to a chemical, physical, or biological agent. Thousands of chemicals have been estimated to have neurotoxic potential. Many persistent and bioaccumulat...

  14. PERSISTENT, BIOACCUMULATIVE, AND TOXIC POLLUTANTS (PBTS)

    EPA Science Inventory

    Article describes the class of compounds known as persistent, bioaccumulative, and toxic pollutants (known as PBTs), including the mechanisms responsible for ability to build up the food chain and for causing adverse health effects and ecosystem damage. Exposure to numerous PBTs ...

  15. Persistence of Adult Learners in Distance Education.

    ERIC Educational Resources Information Center

    Kemp, Wendy C.

    2002-01-01

    Describes a study conducted at Athabasca University (Edmonton, Alberta, Canada) that investigated the relationship between persistence, life events, external commitments, and resiliency in undergraduate distance education. Used scores from the Resiliency Attitudes Scale (RAS), the Life Events Inventory, and a questionnaire relating to external…

  16. Undergraduate Women's Persistence in the Sciences

    ERIC Educational Resources Information Center

    George-Jackson, Casey E.

    2014-01-01

    This study uses longitudinal data of undergraduate students from five public land-grant universities to better understand undergraduate students' persistence in and switching of majors, with particular attention given to women's participation in science, technology, engineering, and mathematics (STEM) fields. Specifically, the study examines…

  17. Anger Expression and Persistence in Young Children

    ERIC Educational Resources Information Center

    He, Jie; Xu, Qinmei; Degnan, Kathryn Amey

    2012-01-01

    This study investigated anger expression during toy removal (TR) in 92 young Chinese children, two to five years of age, and its relations to their persistence in responding to obstacles during two challenging tasks with highly desirable goals [TR and locked box (LB)] and one challenging task with a less desirable goal [impossible perfect circles…

  18. The Persistence of Teacher-Induced Learning

    ERIC Educational Resources Information Center

    Jacob, Brian A.; Lefgren, Lars; Sims, David P.

    2010-01-01

    This paper constructs a statistical model of learning that suggests a systematic way of measuring the persistence of treatment effects in education. This method is straightforward to implement, allows for comparisons across educational treatments, and can be related to intuitive benchmarks. We demonstrate the methodology using student-teacher…

  19. Persistence of Salmonella typhimurium on Fabrics

    PubMed Central

    Wilkoff, Lee J.; Westbrook, Louise; Dixon, Glen J.

    1969-01-01

    The persistence of Salmonella typhimurium (V-31) on wool blanket, wool gabardine, cotton sheeting, cotton knit jersey, cotton terry cloth, and cotton wash-and-wear fabrics was studied. Three methods of exposure were employed to contaminate the fabrics: direct contact, aerosol, and a lyophilized mixture of bacteria and dust having a high content of textile fibers. After contamination, the fabrics were held in 35 or 78% relative humidity at 25 C. The persistence time of S. typhimurium on fabrics held in 35% relative humidity was substantially longer when the fabrics were contaminated by direct contact or by exposure to dust containing bacteria than when contaminated by exposure to aerosolized cultures. Viable bacterial populations persisted for 24 weeks at relatively high population densities on swatches of wool gabardine, cotton sheeting, cotton knit jersey, and cotton terry cloth exposed by direct contact and held in a humidity of 35%. In 78% humidity, bacterial populations persisted on the fabrics for relatively shorter periods of time regardless of the mode of contamination or fabric type. This organism retained its virulence for Swiss mice after being recovered from wool gabardine swatches held 8 weeks in humidities of 35 or 78% and from cotton terry cloth swatches held 6 weeks in the same humidities. Images PMID:4896883

  20. The persistence of bovine viral diarrhea virus.

    PubMed

    Brock, Kenny V

    2003-06-01

    Bovine viral diarrhoea virus (BVDV) has a unique capacity to cause persistent infections of foetuses exposed within the first 150 days of gestation. Preventing foetal BVDV infection will aid in improved control. This unique ability gives BVDV a selective advantage allowing continual mutation and antigenic variation within cattle populations. Therefore, BVDV has become widespread and causes economic losses due to respiratory, reproductive and enteric disease. Vaccination (modified-live or killed) can provide some protection from acute disease and the development of persistently infected foetuses. However, vaccination programmes alone cannot control or eliminate BVDV. In naturally exposed and vaccinated herds, BVDV infections are not self-limiting and may persistent over time. This underscores the ability of the BVDV genome to remain fluid and adapt under selective pressures. Factors influencing persistence of BVDV infections in cattle populations include: non-lytic infections; evasion of host immune responses; foetal infections; acute infections; management practices; contaminated biologics; secondary hosts; defective replicated intermediates; antigenic variation; and replication in privileged anatomical sites.

  1. Environmental persistence of vaccinia virus on materials.

    PubMed

    Wood, J P; Choi, Y W; Wendling, M Q; Rogers, J V; Chappie, D J

    2013-11-01

    Smallpox is caused by the variola virus, and ranks as one of the most serious diseases that could originate from a biological weapon. However, limited data exist on the persistence of variola and related viruses on materials (that may act as fomites), under controlled environmental conditions. To fill these data gaps, we determined the persistence of the vaccinia virus (an established surrogate for the variola virus) as a function of temperature, relative humidity and material. Experiments were conducted with vaccinia virus in a freeze-dried form, using four materials under four sets of environmental conditions. After elapsed times ranging from 1 to 56 days, the virus was extracted from small coupons and quantified via plaque-forming units (PFU). The vaccinia virus was most persistent at low temperature and low relative humidity, with greater than 10(4) PFU recovered from glass, galvanized steel and painted cinder block at 56 days (equivalent to only a c. 2 log reduction). Thus, vaccinia virus may persist from weeks to months, depending on the material and environmental conditions. This study may aid those responsible for infection control to make informed decisions regarding the need for environmental decontamination following the release of an agent such as variola.

  2. Characterizing persistence in JWST NIRCam flight detectors

    NASA Astrophysics Data System (ADS)

    Leisenring, Jarron M.; Rieke, Marcia; Misselt, Karl; Robberto, Massimo

    2016-08-01

    Near-IR detectors are commonly reported to display latent images persisting between integration ramps. After array reset, pixels previously subjected to illumination show an anomalous charge accumulation rate that is initially high but decreases to dark-current levels after several hundred seconds. Depending on the flux intensity and observation time, the resulting persistence can dramatically affect science observations if not properly understood. We characterize the persistent behavior of JWST/NIRCam's flight detectors with respect to source intensity, pixel dwell time, and well fill level in order to better understand the underlying physical processes contributing to this phenomenon. Results show that the coefficients of functional fits to the latent signal directly correlate with the stimulating flux as well as the pixel dwell time, enabling predictions of the latent emission. Such relationships provide the potential to model and remove the majority of the persistent flux in NIRCam detectors. Because NIRCam lacks internal calibration lamps, we discuss other alternatives to characterize per- sistence during flight operations.

  3. Persistence in eye movement during visual search.

    PubMed

    Amor, Tatiana A; Reis, Saulo D S; Campos, Daniel; Herrmann, Hans J; Andrade, José S

    2016-02-11

    As any cognitive task, visual search involves a number of underlying processes that cannot be directly observed and measured. In this way, the movement of the eyes certainly represents the most explicit and closest connection we can get to the inner mechanisms governing this cognitive activity. Here we show that the process of eye movement during visual search, consisting of sequences of fixations intercalated by saccades, exhibits distinctive persistent behaviors. Initially, by focusing on saccadic directions and intersaccadic angles, we disclose that the probability distributions of these measures show a clear preference of participants towards a reading-like mechanism (geometrical persistence), whose features and potential advantages for searching/foraging are discussed. We then perform a Multifractal Detrended Fluctuation Analysis (MF-DFA) over the time series of jump magnitudes in the eye trajectory and find that it exhibits a typical multifractal behavior arising from the sequential combination of saccades and fixations. By inspecting the time series composed of only fixational movements, our results reveal instead a monofractal behavior with a Hurst exponent , which indicates the presence of long-range power-law positive correlations (statistical persistence). We expect that our methodological approach can be adopted as a way to understand persistence and strategy-planning during visual search.

  4. Persistent Marriage Regimes in Changing Times

    ERIC Educational Resources Information Center

    Fussell, Elizabeth; Palloni, Alberto

    2004-01-01

    Marriage among women in Latin America occurs early in life and is nearly universal in spite of the social and economic changes and instability in the region. We use demographic measures to illustrate the precociousness, persistence, and universality of marriage during the past 50 years. We argue that marriage is central to social life because…

  5. Improving Underrepresented Minority Student Persistence in STEM

    ERIC Educational Resources Information Center

    Estrada, Mica; Burnett, Myra; Campbell, Andrew G.; Campbell, Patricia B.; Denetclaw, Wilfred F.; Gutiérrez, Carlos G.; Hurtado, Sylvia; John, Gilbert H.; Matsui, John; McGee, Richard; Okpodu, Camellia Moses; Robinson, T. Joan; Summers, Michael F.; Werner-Washburne, Maggie; Zavala, MariaElena

    2016-01-01

    Members of the Joint Working Group on Improving Underrepresented Minorities (URMs) Persistence in Science, Technology, Engineering, and Mathematics (STEM)--convened by the National Institute of General Medical Sciences and the Howard Hughes Medical Institute--review current data and propose deliberation about why the academic "pathways"…

  6. Persistent PlatformsThe DDG 51 Case

    DTIC Science & Technology

    2015-09-30

    and open systems characteristic of a “persistent platform” that continues in production and service for a greater period of time than would have...originally been contemplated. Keywords: DDG 51 Destroyer, Open Systems, Growth Margin Acquisition Research Program Graduate School of Business...1 The Open Systems Approach

  7. Paradoxical Understandings Regarding Adult Undergraduate Persistence

    ERIC Educational Resources Information Center

    Kasworm, Carol E.

    2014-01-01

    Historically, characteristics of student persistence and graduation completion were most often linked to strategies which honored the full-time residential younger undergraduate. Adult students have been viewed as high-risk and typically problematic students for continuous enrollment and degree completion. This article explores the key paradoxical…

  8. Spreading of persistent infections in heterogeneous populations

    NASA Astrophysics Data System (ADS)

    Sanz, J.; Floría, L. M.; Moreno, Y.

    2010-05-01

    Up to now, the effects of having heterogeneous networks of contacts have been studied mostly for diseases which are not persistent in time, i.e., for diseases where the infectious period can be considered very small compared to the lifetime of an individual. Moreover, all these previous results have been obtained for closed populations, where the number of individuals does not change during the whole duration of the epidemics. Here, we go one step further and analyze, both analytically and numerically, a radically different kind of diseases: those that are persistent and can last for an individual’s lifetime. To be more specific, we particularize to the case of tuberculosis’ (TB) infection dynamics, where the infection remains latent for a period of time before showing up and spreading to other individuals. We introduce an epidemiological model for TB-like persistent infections taking into account the heterogeneity inherent to the population structure. This sort of dynamics introduces new analytical and numerical challenges that we are able to sort out. Our results show that also for persistent diseases the epidemic threshold depends on the ratio of the first two moments of the degree distribution so that it goes to zero in a class of scale-free networks when the system approaches the thermodynamic limit.

  9. High School Economic Composition and College Persistence

    ERIC Educational Resources Information Center

    Niu, Sunny X.; Tienda, Marta

    2013-01-01

    Using a longitudinal sample of Texas high school seniors of 2002 who enrolled in college within the calendar year of high school graduation, we examine variation in college persistence according to the economic composition of their high schools, which serves as a proxy for unmeasured high school attributes that are conductive to postsecondary…

  10. Characteristics of Learning Disabilities Persisting into Adolescence.

    ERIC Educational Resources Information Center

    Whyte, Lillian A.

    1984-01-01

    Describes characteristics of learning disabled teenagers. Describes results of a study of 331 secondary students who completed a self-report inventory showing that childhood learning disability characteristics persist into adolescence, most seriously in the areas of visual perception, fine motor skills, and the ability to write and make spatial…

  11. Persistence in eye movement during visual search

    PubMed Central

    Amor, Tatiana A.; Reis, Saulo D. S.; Campos, Daniel; Herrmann, Hans J.; Andrade, José S.

    2016-01-01

    As any cognitive task, visual search involves a number of underlying processes that cannot be directly observed and measured. In this way, the movement of the eyes certainly represents the most explicit and closest connection we can get to the inner mechanisms governing this cognitive activity. Here we show that the process of eye movement during visual search, consisting of sequences of fixations intercalated by saccades, exhibits distinctive persistent behaviors. Initially, by focusing on saccadic directions and intersaccadic angles, we disclose that the probability distributions of these measures show a clear preference of participants towards a reading-like mechanism (geometrical persistence), whose features and potential advantages for searching/foraging are discussed. We then perform a Multifractal Detrended Fluctuation Analysis (MF-DFA) over the time series of jump magnitudes in the eye trajectory and find that it exhibits a typical multifractal behavior arising from the sequential combination of saccades and fixations. By inspecting the time series composed of only fixational movements, our results reveal instead a monofractal behavior with a Hurst exponent , which indicates the presence of long-range power-law positive correlations (statistical persistence). We expect that our methodological approach can be adopted as a way to understand persistence and strategy-planning during visual search. PMID:26864680

  12. The Contribution of Student Satisfaction to Persistence

    ERIC Educational Resources Information Center

    Schreiner, Laurie A.; Nelson, Denise D.

    2013-01-01

    This study of nearly 30,000 undergraduates at 61 four-year public and private institutions examines the influence of satisfaction on students' persistence in college. Data were collected using the Student Satisfaction Inventory (Schreiner & Juillerat, 1994) and were analyzed by class level. The hierarchical multiple regression analyses…

  13. Persistence of Change: Fume Hood Campaign Lessons

    ERIC Educational Resources Information Center

    Feder, Elah; Robinson, Jennifer; Wakefield, Sarah

    2012-01-01

    Purpose: Sustainability initiatives typically operate for a limited time period, but it is often unclear whether they have lasting effects. The purpose of this paper is to examine a laboratory fume hood campaign, in order to identify factors that might contribute or detract from long-term change persistence. Design/methodology/approach: The…

  14. The Enigmatic Persistence of Anorexia Nervosa

    PubMed Central

    Walsh, B. Timothy

    2014-01-01

    Objective In this review, based on recent advances in cognitive neuroscience, the author presents a formulation in which the marked persistence of anorexia nervosa can be usefully understood as a well-ingrained maladaptive habit. Method The author reviewed the relevant literature on the development and course of anorexia nervosa and interpreted critical features in light of developments in cognitive neuroscience. Results Anorexia nervosa is a well characterized disorder with remarkable persistence both across history and among affected individuals. Food restriction, the salient behavioral feature of the disorder, often begins innocently but gradually takes on a life of its own. Over time, it becomes highly entrenched and resistant to change through either psychological or pharmacological treatment. Cognitive neuroscience has described two related but distinct processes that underlie the acquisition of new patterns of behavior, namely, action-outcome and stimulus-response learning. It is likely that both processes are engaged in the development of anorexia nervosa and that stimulus-response learning (that is, habit formation) is critical to the persistence of the dieting behavior. Conclusions The formulation of the dieting behavior characteristic of anorexia nervosa as a well-entrenched habit provides a basis for understanding the striking persistence of this disorder. This model helps explain the resistance of anorexia nervosa to interventions that have established efficacy in related disorders and implies that addressing the dieting behavior is critical, especially early in the course of the illness, before it has become ingrained. PMID:23429750

  15. Persistence of acanthamoeba antigen following acanthamoeba keratitis

    PubMed Central

    Yang, Y; Matheson, M; Dart, J; Cree, I

    2001-01-01

    AIM—To investigate the hypothesis that persistent corneal and scleral inflammation following acanthamoeba keratitis is not always caused by active amoebic infection but can be due to persisting acanthamoebic antigens
METHODS—24 lamellar corneal biopsy and penetrating keratoplasty specimens were obtained from 14 consecutive patients at various stages of their disease and divided for microscopy and culture. Histological sections were immunostained and screened for the presence of Acanthamoeba cysts by light microscopy. Cultures were carried out using partly homogenised tissues on non-nutrient agar seeded with E coli. Clinical data were obtained retrospectively from the case notes of these patients.
RESULTS—Of the 24 specimens, 20 were obtained from eyes that were clinically inflamed at the time of surgery. Acanthamoeba cysts were present in 16 (80%) of these 20 specimens, while only five (25%) were culture positive. Acanthamoeba cysts were found to persist for up to 31 months after antiamoebic treatment.
CONCLUSION—These findings support the hypothesis that Acanthamoeba cysts can remain in corneal tissue for an extended period of time following acanthamoeba keratitis and may cause persistent corneal and scleral inflammation in the absence of active amoebic infection. In view of these findings, prolonged intensive antiamoebic therapy may be inappropriate when the inflammation is due to retained antigen rather than to viable organisms

 PMID:11222330

  16. The Persistence of Wives' Income Advantage

    ERIC Educational Resources Information Center

    Winslow-Bowe, Sarah

    2006-01-01

    Recent reports using cross-sectional data indicate an increase in the percentage of wives who outearn their husbands, yet we know little about the persistence of wives' income advantage. The present analyses utilize the 1990-1994 waves of the National Longitudinal Survey of Youth 1979 (N = 3,481) to examine wives' long-term earnings advantage.…

  17. The Persistence of African American College Men

    ERIC Educational Resources Information Center

    Beale, Tyson J.

    2010-01-01

    This study explored the family dynamics of persistent African American college men. These students were typical Black males, not those pre-categorized as high-achieving or unprepared for college. The stories of participants revealed their strength, ambition, and intentions to successfully gain a baccalaureate degree. In general Black males are…

  18. Persistence of Ebola Virus in Sterilized Wastewater

    PubMed Central

    2015-01-01

    In the wake of the ongoing 2014/2015 Ebola virus outbreak, significant questions regarding the appropriate handling of Ebola virus-contaminated liquid waste remain, including the persistence of Ebola virus in wastewater. To address these uncertainties, we evaluated the persistence of Ebola virus spiked in sterilized domestic sewage. The viral titer decreased approximately 99% within the first test day from an initial viral titer of 106 TCID50 mL–1; however, it could not be determined if this initial rapid decrease was due to aggregation or inactivation of the viral particles. The subsequent viral titer decrease was less rapid, and infectious Ebola virus particles persisted for all 8 days of the test. The inactivation constant (k) was determined to be −1.08 (2.1 days for a 90% viral titer decrease). Due to experimental conditions, we believe these results to be an upper bound for Ebola virus persistence in wastewater. Wastewater composition is inherently heterogeneous; subsequently, we caution that interpretation of these results should be made within a holistic assessment, including the effects of wastewater composition, dilution, and potential exposure routes within wastewater infrastructure. While it remains unknown if Ebola virus may be transmitted via wastewater, these data demonstrate a potential exposure route to infectious Ebola virus via wastewater and emphasize the value of a precautionary approach to wastewater handling in an epidemic response. PMID:26523283

  19. Persistence of undergraduate women in STEM fields

    NASA Astrophysics Data System (ADS)

    Pedone, Maggie Helene

    The underrepresentation of women in science, technology, engineering, and mathematics (STEM) is a complex problem that continues to persist at the postsecondary level, particularly in computer science and engineering fields. This dissertation explored the pre-college and college level factors that influenced undergraduate women's persistence in STEM. This study also examined and compared the characteristics of undergraduate women who entered STEM fields and non-STEM fields in 2003-2004. The nationally representative Beginning Postsecondary Students Longitudinal Study (BPS:04/09) data set was used for analysis. BPS:04/09 study respondents were surveyed three times (NPSAS:04, BPS:04/06, BPS:04/09) over a six-year period, which enabled me to explore factors related to long-term persistence. Astin's Input-Environment-Output (I-E-O) model was used as the framework to examine student inputs and college environmental factors that predict female student persistence (output) in STEM. Chi-square tests revealed significant differences between undergraduate women who entered STEM and non-STEM fields in 2003-2004. Differences in student demographics, prior academic achievement, high school course-taking patterns, and student involvement in college such as participation in study groups and school clubs were found. Notably, inferential statistics showed that a significantly higher proportion of female minority students entered STEM fields than non-STEM fields. These findings challenge the myth that underrepresented female minorities are less inclined to enter STEM fields. Logistic regression analyses revealed thirteen significant predictors of persistence for undergraduate women in STEM. Findings showed that undergraduate women who were younger, more academically prepared, and academically and socially involved in college (e.g., lived on campus, interacted with faculty, participated in study groups, fine arts activities, and school sports) were more likely to persist in STEM

  20. Rotenone persistence model for montane streams

    USGS Publications Warehouse

    Brown, Peter J.; Zale, Alexander V.

    2012-01-01

    The efficient and effective use of rotenone is hindered by its unknown persistence in streams. Environmental conditions degrade rotenone, but current label instructions suggest fortifying the chemical along a stream based on linear distance or travel time rather than environmental conditions. Our objective was to develop models that use measurements of environmental conditions to predict rotenone persistence in streams. Detailed measurements of ultraviolet radiation, water temperature, dissolved oxygen, total dissolved solids (TDS), conductivity, pH, oxidation–reduction potential (ORP), substrate composition, amount of organic matter, channel slope, and travel time were made along stream segments located between rotenone treatment stations and cages containing bioassay fish in six streams. The amount of fine organic matter, biofilm, sand, gravel, cobble, rubble, small boulders, slope, pH, TDS, ORP, light reaching the stream, energy dissipated, discharge, and cumulative travel time were each significantly correlated with fish death. By using logistic regression, measurements of environmental conditions were paired with the responses of bioassay fish to develop a model that predicted the persistence of rotenone toxicity in streams. This model was validated with data from two additional stream treatment reaches. Rotenone persistence was predicted by a model that used travel time, rubble, and ORP. When this model predicts a probability of less than 0.95, those who apply rotenone can expect incomplete eradication and should plan on fortifying rotenone concentrations. The significance of travel time has been previously identified and is currently used to predict rotenone persistence. However, rubble substrate, which may be associated with the degradation of rotenone by adsorption and volatilization in turbulent environments, was not previously considered.

  1. Kaposi’s Sarcoma Herpesvirus Genome Persistence

    PubMed Central

    Juillard, Franceline; Tan, Min; Li, Shijun; Kaye, Kenneth M.

    2016-01-01

    Kaposi’s sarcoma-associated herpesvirus (KSHV) has an etiologic role in Kaposi’s sarcoma, primary effusion lymphoma, and multicentric Castleman’s disease. These diseases are most common in immunocompromised individuals, especially those with AIDS. Similar to all herpesviruses, KSHV infection is lifelong. KSHV infection in tumor cells is primarily latent, with only a small subset of cells undergoing lytic infection. During latency, the KSHV genome persists as a multiple copy, extrachromosomal episome in the nucleus. In order to persist in proliferating tumor cells, the viral genome replicates once per cell cycle and then segregates to daughter cell nuclei. KSHV only expresses several genes during latent infection. Prominent among these genes, is the latency-associated nuclear antigen (LANA). LANA is responsible for KSHV genome persistence and also exerts transcriptional regulatory effects. LANA mediates KSHV DNA replication and in addition, is responsible for segregation of replicated genomes to daughter nuclei. LANA serves as a molecular tether, bridging the viral genome to mitotic chromosomes to ensure that KSHV DNA reaches progeny nuclei. N-terminal LANA attaches to mitotic chromosomes by binding histones H2A/H2B at the surface of the nucleosome. C-terminal LANA binds specific KSHV DNA sequence and also has a role in chromosome attachment. In addition to the essential roles of N- and C-terminal LANA in genome persistence, internal LANA sequence is also critical for efficient episome maintenance. LANA’s role as an essential mediator of virus persistence makes it an attractive target for inhibition in order to prevent or treat KSHV infection and disease. PMID:27570517

  2. Long persistent luminescence in the ultraviolet in Pb(2+)-doped Sr2MgGe2O7 persistent phosphor.

    PubMed

    Liang, Yanjie; Liu, Feng; Chen, Yafei; Sun, Kangning; Pan, Zhengwei

    2016-01-28

    We extend the persistent luminescence into the ultraviolet spectral region by developing a new ultraviolet persistent phosphor Sr2MgGe2O7:Pb(2+). The Sr2MgGe2O7:Pb(2+) phosphor exhibits strong persistent luminescence peaking at 370 nm and a long persistence time of >12 h after excitation. The phosphor also exhibits a photo-stimulated persistent luminescence capability.

  3. Early palaeozoic palaeomagnetism in Australia I. Cambrian results from the Flinders Ranges, South Australia II. Late Early Cambrian results from Kangaroo Island, South Australia III. Middle to early-Late Cambrian results from the Amadeus Basin, Northern Territory

    NASA Astrophysics Data System (ADS)

    Klootwijk, C. T.

    1980-04-01

    I. Cambrian results from the Flinders Ranges, South Australia A total of 460 samples from six sequences spanning the Cambrian succession of the Flinders Ranges (Adelaide "Geosyncline", South Australia) has been analyzed through thermal demagnetization studies. All samples showed a recent field component, generally constituting more than 50% of the initial intensity, which in most cases was removed by 200-400°C. Two characteristic magnetic components have been identified: (A) A secondary magnetic component of Cambro-Ordovician age (S-pole at 75.3°E 26.0°N, α95 = 7.4°, N = 5 localities) interpreted as having been induced by thermochemical activity during a period of enhanced heat flux prior to the Late Cambrian-Early Ordovician diastrophistic phases of the Delamarian Orogeny. (B) A primary magnetic component, which indicates rapid polar motion during the Early Cambrian and a much reduced polar motion during the Middle Cambrian. Representative palaeomagnetic pole positions for the primary component are: (1) Basal Hawker Group (earliest Cambrian): S-pole at 2.3°E 26.7°S, d p = 8.1°, d m = 14.3°, N = 10 (sites). (2) Billy Creek Formation— Wirrealpa Limestone— Aroona Creek Limestone (late Early Cambrian to early Middle Cambrian): S-pole at 20.1°E 37.4°S, d p = 7.2°, dm = 14.4°, N = 11(sites). (3) Basal Lake Frame Group (Middle Cambrian): S-pole at 26.1°E 29.3°S, d p = 6.6°, d m = 13.1°, N =10 (sites). (4) Pantapinna Formation (late Middle Cambrian?): S-pole at 29.2°E 36.4°S, d p = 8.4°, dm = 16.7°, N = 4 (sites). Available data suggest that deposition of the Lake Frome Group beds probably did not continue into the Late Cambrian. II. Late Early Cambrian results from Kangaroo Island, South Australia A total of 108 block samples from a late Early Cambrian red-bed sequence on Kangaroo Island (Adelaide "Geosyncline", South Australia) has been analysed through thermal demagnetization studies. All samples contained a recent field component of

  4. Lactase haplotype frequencies in Caucasians: association with the lactase persistence/non-persistence polymorphism.

    PubMed

    Harvey, C B; Hollox, E J; Poulter, M; Wang, Y; Rossi, M; Auricchio, S; Iqbal, T H; Cooper, B T; Barton, R; Sarner, M; Korpela, R; Swallow, D M

    1998-05-01

    A genetic polymorphism is responsible for determining that some humans express lactase at high levels throughout their lives and are thus lactose tolerant, while others lose lactase expression during childhood and are lactose intolerant. We have previously shown that this polymorphism is controlled by an element or elements which act in cis to the lactase gene. We have also reported that 7 polymorphisms in the lactase gene are highly associated and lead to only 3 common haplotypes (A, B and C) in individuals of European extraction. Here we report the frequencies of these polymorphisms in Caucasians from north and south Europe and also from the Indian sub-continent, and show that the alleles differ in frequency, the B and C haplotypes being much more common in southern Europe and India. Allelic association studies with lactase persistence and non-persistence phenotypes show suggestive evidence of association of lactase persistence with certain alleles. This association was rather more clear in the analysis of small families, where haplotypes could be determined. Furthermore haplotype and RNA transcript analysis of 11 unrelated lactase persistent individuals shows that the persistence (highly expressed) allele is almost always on the A haplotype background. Non-persistence is found on a variety of haplotypes including A. Thus it appears that lactase persistence arose more recently than the DNA marker polymorphisms used here to define the main Caucasian haplotypes, possibly as a single mutation on the A haplotype background. The high frequency of the A haplotype in northern Europeans is consistent with the high frequency of lactase persistence.

  5. Persistent Primitive Trigeminal Artery That Mimics Persistent Primitive Otic Artery on Cerebral Angiography

    PubMed Central

    Lee, Kwangho; Park, Insung; Han, Jongwoo

    2016-01-01

    Persistent primitive trigeminal artery (PPTA) is the most common carotid-basilar anastomosis; on the other hand, persistent primitive otic artery (PPOA) is extremely rare. PPTA is often misdiagnosed as PPOA on cerebral angiography. We present a case of PPTA that mimicked PPOA on cerebral angiography. We further describe the utility of brain computed tomography angiography for differential diagnosis of PPTA from PPOA, together with a review of previous literature. PMID:27790403

  6. Persistence of interest in science, technology, engineering and mathematics: An analysis of persisting and non-persisting students

    NASA Astrophysics Data System (ADS)

    White, Jeffry L.

    While there has been an increase in enrollment, interest in science, technology, engineering, and mathematics (STEM) has been declining on college campuses since 1967. Higher enrollment does not transfer to an increase in the number of minorities in the STEM fields. The majority-minority enrollment ratio is nearly 2:1 but the gap widens to 4:1 when it comes to graduation. In fact, underrepresented minorities (URM) earned only 12% of the STEM degrees awarded in 1998. When the higher attrition and lower graduation rates of URM are scrutinized, upwards of 60% changed majors or dropped out of STEM. Further investigation reveals the most frequently cited reasons for departure were loss of initial interest, developed a greater interest in another field, or were turned off by the STEM disciplines. A primarily exploratory study was conducted into the conditions necessary for academic interest in the STEM fields to persist. A model based on student engagement (Astin, 1977) and interest operations (Prenzel, 1988a) theories was used with a random sample of URM at universities participating in the Ohio Science and Engineering Alliance. Survey research was employed to investigate interest development and the effect of student retention programs and activities on such interest. The latter part of the study could not be fully examined when 95% reported not utilizing retention services. For the section on interest, an online survey using a 5-point Likert scale was validated using principal components analysis. A binominal logistic regression was used to predict membership in one of two possible groups: persisters and students at-risk for not persisting. The major conclusions are: (1) While 3 variables (feelings, learning and difficulty) were statistically significant only one, feelings was substantively significant. (2) Persistence increased 80.9% for each 1-unit increase in feelings and 9.9% for learning. (3) Persistence decreased 19.8% for each one-unit increase in difficulty

  7. Persistent Identifiers for Dutch cultural heritage institutions

    NASA Astrophysics Data System (ADS)

    Ras, Marcel; Kruithof, Gijsbert

    2016-04-01

    Over the past years, more and more collections belonging to archives, libraries, media, museums, and knowledge institutes are being digitised and made available online. These are exciting times for ALM institutions. They are realising that, in the information society, their collections are goldmines. Unfortunately most heritage institutions in the Netherlands do not yet meet the basic preconditions for long-term availability of their collections. The digital objects often have no long lasting fixed reference yet. URL's and web addresses change. Some digital objects that were referenced in Europeana and other portals can no longer be found. References in scientific articles have a very short life span, which is damaging for scholarly research. In 2015, the Dutch Digital Heritage Network (NDE) has started a two-year work program to co-ordinate existing initiatives in order to improve the (long-term) accessibility of the Dutch digital heritage for a wide range of users, anytime, anyplace. The Digital Heritage Network is a partnership established on the initiative of the Ministry of Education, Culture and Science. The members of the NDE are large, national institutions that strive to professionally preserve and manage digital data, e.g. the National Library, The Netherlands Institute for Sound and Vision, the Netherlands Cultural Heritage Agency, the Royal Netherlands Academy of Arts and Sciences, the National Archive of the Netherlands and the DEN Foundation, and a growing number of associations and individuals both within and outside the heritage sector. By means of three work programmes the goals of the Network should be accomplished and improve the visibility, the usability and the sustainability of digital heritage. Each programme contains of a set of projects. Within the sustainability program a project on creating a model for persistent identifiers is taking place. The main goals of the project are (1) raise awareness among cultural heritage institutions on the

  8. [Persistent coughs in children and adolescents].

    PubMed

    Benoist, G; Bidat, E

    2015-04-01

    A persistent cough lasting more than 4-8weeks should lead to a diagnostic workup. A detailed history and a full clinical examination, with a chest X-ray, are essential for initial assessment. Most reported causes of chronic cough in children are post-nasal drip syndrome, cough variant asthma (a spirometry with test of bronchodilator responsiveness should be attempted in children old enough to perform the manoeuvres). GERD is often suspected but a causal relationship is difficult to establish. Protracted bacterial bronchitis, post-infectious cough (B. pertussis, Mycoplasma) and somatoform respiratory disorders (including hyperventilation syndrome) are also common. Signs which are pointers suggesting an underlying respiratory or systemic disease require further investigation: inhaled foreign bodies, cystic fibrosis and chronic lung diseases with bronchiectasis, airway abnormalities, interstitial lung diseases need to be considered. Recent reports of refractory coughs have identified features of a sensory neuropathy disorder, and might explain persistent cough triggers.

  9. The Persistence of American Indian Health Disparities

    PubMed Central

    Jones, David S.

    2006-01-01

    Disparities in health status between American Indians and other groups in the United States have persisted throughout the 500 years since Europeans arrived in the Americas. Colonists, traders, missionaries, soldiers, physicians, and government officials have struggled to explain these disparities, invoking a wide range of possible causes. American Indians joined these debates, often suggesting different explanations. Europeans and Americans also struggled to respond to the disparities, sometimes working to relieve them, sometimes taking advantage of the ill health of American Indians. Economic and political interests have always affected both explanations of health disparities and responses to them, influencing which explanations were emphasized and which interventions were pursued. Tensions also appear in ongoing debates about the contributions of genetic and socioeconomic forces to the pervasive health disparities. Understanding how these economic and political forces have operated historically can explain both the persistence of the health disparities and the controversies that surround them. PMID:17077399

  10. UAV Cooperation Architectures for Persistent Sensing

    SciTech Connect

    Roberts, R S; Kent, C A; Jones, E D

    2003-03-20

    With the number of small, inexpensive Unmanned Air Vehicles (UAVs) increasing, it is feasible to build multi-UAV sensing networks. In particular, by using UAVs in conjunction with unattended ground sensors, a degree of persistent sensing can be achieved. With proper UAV cooperation algorithms, sensing is maintained even though exceptional events, e.g., the loss of a UAV, have occurred. In this paper a cooperation technique that allows multiple UAVs to perform coordinated, persistent sensing with unattended ground sensors over a wide area is described. The technique automatically adapts the UAV paths so that on the average, the amount of time that any sensor has to wait for a UAV revisit is minimized. We also describe the Simulation, Tactical Operations and Mission Planning (STOMP) software architecture. This architecture is designed to help simulate and operate distributed sensor networks where multiple UAVs are used to collect data.

  11. Persistent Hypoglycemia in Patient with Hodgkin's Disease

    PubMed Central

    Lim, Harold Cinco; Munshi, Lubna Bashir; Sharon, David

    2015-01-01

    Hypoglycemia is a rare complication of Hodgkin's disease. Several explanations have been postulated but the exact pathophysiology is not well understood. We are presenting a case of newly diagnosed Stage IV Hodgkin's disease that developed persistent and recurrent hypoglycemia despite giving glucagon, repeated 50% dextrose, and D5 and D10 continuous infusion. Hypoglycemia workup showed the C-peptide level to be low. Patient was suspected of having hypoglycemia related to lymphoma and was given a trial of prednisone which resolved the hypoglycemic episodes and made the patient euglycemic for the rest of his hospital stay. The presence of a substance that mimicked the effects of insulin was highly suspected. Several case reports strengthen the hypothesis of an insulin-like growth factor or antibodies secreted by the cancer cells causing hypoglycemia in Hodgkin's disease but none of them have been confirmed. Further investigation is warranted to more clearly define the pathophysiology of persistent hypoglycemia in patients with Hodgkin's disease. PMID:26839722

  12. Mechanisms of Toxoplasma gondii persistence and latency

    PubMed Central

    Sullivan, William J.; Jeffers, Victoria

    2011-01-01

    Toxoplasma gondii is an obligate intracellular protozoan parasite that causes opportunistic disease, particularly in immunocompromised individuals. Central to its transmission and pathogenesis is the ability of the proliferative stage (tachyzoite) to convert into latent tissue cysts (bradyzoites). Encystment allows Toxoplasma to persist in the host, and affords the parasite a unique opportunity to spread to new hosts without proceeding through its sexual stage, which is restricted to felids. Bradyzoite tissue cysts can cause reactivated toxoplasmosis if host immunity becomes impaired. A greater understanding of the molecular mechanisms orchestrating bradyzoite development is needed to better manage the disease. Here we will review key studies that have contributed to our knowledge about this persistent form of the parasite and how to study it, with a focus on how cellular stress can signal for the reprogramming of gene expression needed during bradyzoite development. PMID:22091606

  13. Emotional persistence in online chatting communities

    NASA Astrophysics Data System (ADS)

    Garas, Antonios; Garcia, David; Skowron, Marcin; Schweitzer, Frank

    2012-05-01

    How do users behave in online chatrooms, where they instantaneously read and write posts? We analyzed about 2.5 million posts covering various topics in Internet relay channels, and found that user activity patterns follow known power-law and stretched exponential distributions, indicating that online chat activity is not different from other forms of communication. Analysing the emotional expressions (positive, negative, neutral) of users, we revealed a remarkable persistence both for individual users and channels. I.e. despite their anonymity, users tend to follow social norms in repeated interactions in online chats, which results in a specific emotional ``tone'' of the channels. We provide an agent-based model of emotional interaction, which recovers qualitatively both the activity patterns in chatrooms and the emotional persistence of users and channels. While our assumptions about agent's emotional expressions are rooted in psychology, the model allows to test different hypothesis regarding their emotional impact in online communication.

  14. Climate change and decreasing herbicide persistence.

    PubMed

    Bailey, Steven W

    2004-02-01

    A herbicide degradation model, using real weather data for the period 1980-2001, has been used to estimate the change in persistence of autumn-applied isoproturon over this period. The results suggest that soil residues fell to the minimum for weed control on average approximately 30 days earlier over the last 5 years of this period than in the first 5 years, equivalent to a reduction of approximately 25% in the duration of weed control. This decline in persistence is attributed to increasing soil temperature. The results are discussed in relation to recent observations and predictions on climate change. The relevance of the findings to other pesticides and future weed control is considered.

  15. Endometritis: Managing Persistent Post-Breeding Endometritis.

    PubMed

    Canisso, Igor F; Stewart, Jamie; Coutinho da Silva, Marco A

    2016-12-01

    Endometritis was rated as the third most common medical problem encountered in adult horses in North America. It is the leading cause of subfertility in broodmares and is a major contributor to economic loss in the horse breeding industry, with pregnancy rates reported to be as low as 21% in mares with severe endometritis. Endometritis may be categorized as: endometrosis (chronic degenerative endometritis), acute, chronic, active, dormant, subclinical, clinical, and persistent post-breeding. These classifications are not mutually exclusive, and mares may change categories within breeding seasons or estrous cycles or may fit in multiple classifications. This chapter will focus on discussing etiology and management strategies for mares affected by persistent post-breeding endometritis. Overall, these mares are considered subfertile but acceptable pregnancy and foaling rates can be achieved with appropriate breeding management.

  16. [Persistent hyperinsulinemic hypoglycemia of the neonate].

    PubMed

    Maglajlić, Svjetlana; Jesić, Milos; Necić, Svetislav; Lukac, Marija; Sindjić, Sanja; Jesić, Maja; Vujović, Dragana

    2004-10-01

    Persistent hyperinsulinemic hypoglicemia of the neonate is a rare heterogenous disease (clinically, histologically, metabolically and genetically), which is characterized by inadequatly high insuline rates in the presence of severe hypoglicemia. Hyperinsulinism, rather a syndrome than a disease, of which the main metabolic feature is hypoglicemia and decreased concentration of free fatty acids and ketones in serum (insulin inhibits lypolisis and synthesizes ketonic bodies), presents a major diagnostic and therapeutic chalenge. The disease is often followed by brain atrophy contributed by the attacks of hypoglicemia. It is inherited as an autosomally recessive and autosomally dominant disease. The genetic defects is located on the short arm of the chromosome 11. The authors report a successfully applied conservative treatment in a neonate with persistent hyperinsulinemic hypoglicemia.

  17. Imaging approach to persistent neonatal jaundice

    SciTech Connect

    Kirks, D.; Coleman, R.E.; Filston, H.C.; Rosenberg, E.R.; Merten, D.F.

    1984-03-01

    Fifteen patients with persistent neonatal jaundice were evaluated by sonography and radionuclide scintigraphy. The sonographic features of both neonatal hepatitis and biliary atresia are nonspecific. Hepatobiliary scintigraphy after phenobarbital pretreatment in patients with neonatal hepatitis demonstrates normal hepatic extraction and delayed tracer excretion into the gastrointestinal tract. If there is neonatal hepatitis with severe hepatocellular damage, the hepatic extraction of tracer activity is decreased and excretion may be delayed or absent. Patients under 3 months of age with biliary atresia have normal hepatic extraction of tracer with no excretion into the gastrointestinal tract. Sonography in patients with a choledochal cyst shows a cystic mass in the porta hepatis with associated bile-duct dilatation. Hepatobiliary scintigraphy confirms that the choledochal cyst communicates with the biliary system. Initial sonography demonstrates hepatobiliary anatomy; subsequent phenobarbital-enhanced radionuclide scintigraphy determines hepatobiliary function. An expedient diagnostic approach is recommended for the evaluation of persistent neonatal jaundice.

  18. PHACE Syndrome: Persistent Fetal Vascular Anomalies

    PubMed Central

    Prochazka, V.; Hrbac, T.; Chmelova, J.; Skoloudik, D.; Prochazka, M.

    2005-01-01

    Summary PHACE(S) syndrome is an acronym for neurocutaneous disease encompassing the expression of (P) posterior cranial fossa malformations, (H) facial haemangiomas, (A) arterial anomalies, (C) aortic coarctaion and other cardiac defects, (E) eye abnormalities and (S) for sternal malformation or stenotic arterial diseases. We report on a case of PHACE syndrome complete expression with persistent fetal vascular anomalies unusually in a 55-year-old women with large bilateral facial and neck haemangioma and posterior fossa circulation insufficiency. PMID:20584448

  19. Persistent müllerian duct syndrome.

    PubMed

    Köksal, S; Tokmak, H; Tibet, H B; Olgun, E

    1995-01-01

    Persistent müllerian duct syndrome is a rare form of male pseudohermaphroditism. It is usually diagnosed in the early years of life. A case is reported of normal male appearance with bilateral undescended testicles and a right inguinal hernia. On exploration a uterus, two fallopian tubes and a testis were found in the hernial sac. As these patients have an increased risk of gonadal tumours they should be kept under long-term review.

  20. Persistent Confusion and Controversy Surrounding Gene Patents

    PubMed Central

    Guerrini, Christi J.; Majumder, Mary A.; McGuire, Amy L.

    2016-01-01

    There is persistent confusion and controversy surrounding basic issues of patent law relevant to the genomics industry. Uncertainty and conflict can lead to the adoption of inefficient practices and exposure to liability. The development of patent-specific educational resources for industry members, as well as the prompt resolution of patentability rules unsettled by recent U.S. Supreme Court decisions, are therefore urgently needed. PMID:26849516

  1. Typology of State Types: Persistence and Transition

    DTIC Science & Technology

    2015-04-28

    developed in this paper, a more tailored policy to each type of state might be applied. Such nuances cannot be captured by broader categorizations such as...DRDC-RDDC-2014-P105 1 Typology of State Types : Persistence and Transition Peter Tikuisis Defence Research and Development Canada David...Additionally, changes in legitimacy most often led state transitions into or out of fragility. Implications of intervention policy for transitioning

  2. [Medically unexplained persistent pain syndrome: psychoanalytic approach].

    PubMed

    Davoine, Georges-André; Godinat, Gilles; Petite, Dominique; Saurer, Andreas

    2013-06-26

    Chronic persistant pain is very challenging as the patient and his/her therapist are confronted with a lack of explanation about the origin of pain. The relationship has also to face many obstacles such as psychological strain or psychosocial tensions such as disagreements about the patients working capacity. Nevertheless continuing attention from a solid and secure therapist may progressively lead to changes in pain experience, the emergence of emotions and improved therapist patient interactions.

  3. Persistence of antigen in nonarthritic joints.

    PubMed Central

    Fox, A; Glynn, L E

    1975-01-01

    The presence of antigen, IgG and C3 was shown by radioautography and immunofluorescence in the collagenous tissues of the joints of animals injected intra-articularly with antigen after having been previously immunized with that antigen in Freund's incomplete adjuvant. Since these joints were shown to be virtually free of inflammatory reactions, we suggest that the persistence of immune complexes activating complement cannot fully explain the chronicity of experimental allergic arthritis. Images PMID:769709

  4. Persistent HIV-1 replication during antiretroviral therapy

    PubMed Central

    Martinez-Picado, Javier; Deeks, Steven G.

    2016-01-01

    Purpose of review The present review will highlight some of the recent findings regarding the capacity of HIV-1 to replicate during antiretroviral therapy (ART). Recent findings Although ART is highly effective at inhibiting HIV replication, it is not curative. Several mechanisms contribute to HIV persistence during ART, including HIV latency, immune dysfunction, and perhaps persistent low-level spread of the virus to uninfected cells (replication). The success in curing HIV will depend on efficiently targeting these three aspects. The degree to which HIV replicates during ART remains controversial. Most studies have failed to find any evidence of HIV evolution in blood, even with samples collected over many years, although a recent very intensive study of three individuals suggested that the virus population does shift, at least during the first few months of therapy. Stronger but still not definitive evidence for replication comes from a series of studies in which standard regimens were intensified with an integration inhibitor, resulting in changes in episomal DNA (blood) and cell-associated RNA (tissue). Limited drug penetration within tissues and the presence of immune sanctuaries have been argued as potential mechanisms allowing HIV to spread during ART. Mathematical models suggest that HIV replication and evolution is possible even without the selection of fully drug-resistant variants. As persistent HIV replication could have clinical consequences and might limit the efficacy of curative interventions, determining if HIV replicates during ART and why, should remain a key focus of the HIV research community. Summary Residual viral replication likely persists in lymphoid tissues, at least in a subset of individuals. Abnormal levels of immune activation might contribute to sustain virus replication. PMID:27078619

  5. Persistent genital arousal disorder: a clinical challenge

    PubMed Central

    Gadit, Amin

    2013-01-01

    A 54-year-old woman presented to a community-based psychiatric clinic with unique problem of persistent genital arousal disorder. All relevant investigations were normal. Treatment with psychotropic medication and psychotherapy did not help. The patient though reported improvement in mood. The patient has been followed up since 2011 and visits the clinic every 3 months without much improvement in the disorder. Hence, this case has become a clinical challenge in terms of treatment. PMID:23697448

  6. API Development for Persistent Data Sessions Support

    DTIC Science & Technology

    2005-03-01

    for persistent sessions. This testing is conducted on a wired environment to reconnect the FTP, RTSP or Telnet respectively. If time permits, the...example of a low level interface used by application programmers is the Berkeley Sockets interface which UNIX systems support [5]. 19 Many...types of protocols involved for the session. Real Time Streaming Protocol ( RTSP ) and Real Time Protocol (RTP) . RTSP is used for video control

  7. Pregnancy persistently affects memory T cell populations.

    PubMed

    Kieffer, Tom E C; Faas, Marijke M; Scherjon, Sicco A; Prins, Jelmer R

    2017-02-01

    Pregnancy is an immune challenge to the maternal immune system. The effects of pregnancy on maternal immunity and particularly on memory T cells during and after pregnancy are not fully known. This observational study aims to show the short term and the long term effects of pregnancy on the constitution, size and activation status of peripheral human memory T-lymphocyte populations. Effector memory (EM) and central memory (CM) T-lymphocytes were analyzed using flow cytometry of peripheral blood from 14 nulligravid, 12 primigravid and 15 parous women that were on average 18 months postpartum. The short term effects were shown by the significantly higher CD4+ EM cell and activated CD4+ memory cell proportions in primigravid women compared to nulligravid women. The persistent effects found in this study were the significantly higher proportions of CD4+ EM, CD4+ CM and activated memory T cells in parous women compared to nulligravid women. In contrast to CD4+ cells, activation status of CD8+ memory cells did not differ between the groups. This study shows that pregnancy persistently affects the pre-pregnancy CD4+ memory cell pool in human peripheral blood. During pregnancy, CD4+ T-lymphocytes might differentiate into EM cells followed by persistent higher proportions of CD4+ CM and EM cells postpartum. The persistent effects of pregnancy on memory T cells found in this study support the hypothesis that memory T cells are generated during pregnancy and that these cells could be involved in the lower complication risks in multiparous pregnancies in humans.

  8. Improving Underrepresented Minority Student Persistence in STEM

    PubMed Central

    Estrada, Mica; Burnett, Myra; Campbell, Andrew G.; Campbell, Patricia B.; Denetclaw, Wilfred F.; Gutiérrez, Carlos G.; Hurtado, Sylvia; John, Gilbert H.; Matsui, John; McGee, Richard; Okpodu, Camellia Moses; Robinson, T. Joan; Summers, Michael F.; Werner-Washburne, Maggie; Zavala, MariaElena

    2016-01-01

    Members of the Joint Working Group on Improving Underrepresented Minorities (URMs) Persistence in Science, Technology, Engineering, and Mathematics (STEM)—convened by the National Institute of General Medical Sciences and the Howard Hughes Medical Institute—review current data and propose deliberation about why the academic “pathways” leak more for URM than white or Asian STEM students. They suggest expanding to include a stronger focus on the institutional barriers that need to be removed and the types of interventions that “lift” students’ interests, commitment, and ability to persist in STEM fields. Using Kurt Lewin’s planned approach to change, the committee describes five recommendations to increase URM persistence in STEM at the undergraduate level. These recommendations capitalize on known successes, recognize the need for accountability, and are framed to facilitate greater progress in the future. The impact of these recommendations rests upon enacting the first recommendation: to track successes and failures at the institutional level and collect data that help explain the existing trends. PMID:27543633

  9. An evaluation of chemical persistence screening approaches.

    PubMed

    Pennington, D W

    2001-09-01

    A chemical's ability to persist in the environment is an important criterion in determining whether concern is warranted. Screening is commonly conducted based on the maximum degradation half-life of the chemical in any given medium (air, water, soil and sediment), or in terms of model-based estimates of the chemical's overall persistence (half-life or residence time) in the environment. In practice, however, both approaches are hindered by the limited availability of degradation data. Straightforward guidelines are therefore proposed in this paper to help predetermine which half-lives are likely to be pertinent, irrespective of the screening approach adopted. The guidelines are based on partitioning coefficients (Henry's Law constant and the octanol-water partitioning coefficient). The values selected for use in the guidelines result in a quantifiable trade-off between data acquisition requirements and uncertainty. Initial screening can be performed with whatever data is readily available. Overall persistence predictions will be conservative. False-negatives are not generated. The guideline values can then be adjusted iteratively to facilitate step-wise or tiered screening. Using this iterative approach in national and international screening initiatives will result in significant time and money savings.

  10. Persistence of antibiotic resistance in bacterial populations.

    PubMed

    Andersson, Dan I; Hughes, Diarmaid

    2011-09-01

    Unfortunately for mankind, it is very likely that the antibiotic resistance problem we have generated during the last 60 years due to the extensive use and misuse of antibiotics is here to stay for the foreseeable future. This view is based on theoretical arguments, mathematical modeling, experiments and clinical interventions, suggesting that even if we could reduce antibiotic use, resistant clones would remain persistent and only slowly (if at all) be outcompeted by their susceptible relatives. In this review, we discuss the multitude of mechanisms and processes that are involved in causing the persistence of chromosomal and plasmid-borne resistance determinants and how we might use them to our advantage to increase the likelihood of reversing the problem. Of particular interest is the recent demonstration that a very low antibiotic concentration can be enriching for resistant bacteria and the implication that antibiotic release into the environment could contribute to the selection for resistance. Several mechanisms are contributing to the stability of antibiotic resistance in bacterial populations and even if antibiotic use is reduced it is likely that most resistance mechanisms will persist for considerable times.

  11. Topological microstructure analysis using persistence landscapes

    NASA Astrophysics Data System (ADS)

    Dłotko, Paweł; Wanner, Thomas

    2016-11-01

    Phase separation mechanisms can produce a variety of complicated and intricate microstructures, which often can be difficult to characterize in a quantitative way. In recent years, a number of novel topological metrics for microstructures have been proposed, which measure essential connectivity information and are based on techniques from algebraic topology. Such metrics are inherently computable using computational homology, provided the microstructures are discretized using a thresholding process. However, while in many cases the thresholding is straightforward, noise and measurement errors can lead to misleading metric values. In such situations, persistence landscapes have been proposed as a natural topology metric. Common to all of these approaches is the enormous data reduction, which passes from complicated patterns to discrete information. It is therefore natural to wonder what type of information is actually retained by the topology. In the present paper, we demonstrate that averaged persistence landscapes can be used to recover central system information in the Cahn-Hilliard theory of phase separation. More precisely, we show that topological information of evolving microstructures alone suffices to accurately detect both concentration information and the actual decomposition stage of a data snapshot. Considering that persistent homology only measures discrete connectivity information, regardless of the size of the topological features, these results indicate that the system parameters in a phase separation process affect the topology considerably more than anticipated. We believe that the methods discussed in this paper could provide a valuable tool for relating experimental data to model simulations.

  12. Trustworthy persistent identifier systems of the future

    NASA Astrophysics Data System (ADS)

    Golodoniuc, Pavel; Klump, Jens; Car, Nicholas

    2016-04-01

    Over the last two decades, persistent identifier (PID) systems have seen some significant changes in their governance policies, system capabilities, and technology. The development of most systems was driven by two main application areas, namely archives and libraries. Guidelines and criteria for trustworthy PID systems have been clearly devised (Bütikofer, 2009) and many PID system implementations for the identification of static digital objects have been built (e.g., PURL). However systems delivering persistent identifiers for dynamic datasets are not yet mature. There has been a rapid proliferation of different PID systems caused by the specific technical or organisational requirements of various communities that could not be met by existing systems such as DOI, ISBN, and EAN. Many of these different systems were limited by their inability to provide native means of persistent identifier resolution. This has prompted a decoupling of PID-associated data from the resolution service and this is where the Handle system has played a significant role. The Handle allowed to build a distributed system of independently managed resolver services. A trustworthy PID system must be designed to outlive the objects it provides persistent identifiers for, which may cease to exist or otherwise be deprecated, and the technology used to implement it, which will certainly need to change with time. We propose that such a system should rest on four pillars of agreements - (i) definitions, (ii) policies, (iii) services, and (iv) data services, to ensure longevity. While we believe all four pillars are equally important, we intentionally leave regulating aspects of issuing of identifiers and their registration out of the scope of this paper and focus on the agreements that have to be established between PID resolver services and the data sources indicated by the persistent identifiers. We propose an approach to development of PID systems that combines the use of (a) the Handle system

  13. Persistent Structural Priming from Language Comprehension to Language Production

    ERIC Educational Resources Information Center

    Bock, Kathryn; Dell, Gary S.; Chang, Franklin; Onishi, Kristine H.

    2007-01-01

    To examine the relationship between syntactic processes in language comprehension and language production, we compared structural persistence from sentence primes that speakers heard to persistence from primes that speakers produced. [Bock, J. K., & Griffin, Z. M. (2000). The persistence of structural priming: transient activation or implicit…

  14. Mitigation of H2RG persistence with image illumination

    NASA Astrophysics Data System (ADS)

    McLeod, Brian A.; Smith, Roger

    2016-08-01

    Residual charge generation, or image persistence, in infrared detectors is a problem that affects many low-light astronomical instruments. The HAWAII-2RG in the MMT and Magellan Infrared Spectrograph shows significant persistence when first powered up. We describe here how we reduce the persistence sensitivity of this detector by exposure to light.

  15. CTEPP OVERVIEW: A PILOT STUDY OF CHILDREN'S TOTAL EXPOSURE TO PERSISTENT PESTICIDES AND OTHER PERSISTENT ORGANIC POLLUTANTS

    EPA Science Inventory

    The research study, "Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants," (CTEPP) is a pilot-scale project involving about 260 children in their everyday surroundings. The objectives of CTEPP are twofold: (1) To measure the agg...

  16. Environmental persistence of amphibian and reptilian ranaviruses.

    PubMed

    Nazir, J; Spengler, M; Marschang, R E

    2012-04-26

    Ranaviruses infect fish, amphibians, and reptiles. The present study was conducted to compare the persistence of amphibian and reptilian ranaviruses in a pond habitat. The 4 viruses used in this study included 2 amphibian ranaviruses, Frog virus 3 (FV3, the type species of the genus Ranavirus) and an isolate from a frog, and 2 ranaviruses of reptilian origin (from a tortoise and from a gecko). A sandwich germ-carrier technique was used to study the persistence of these viruses in sterile and unsterile pond water (PW) and soil obtained from the bank of a pond. For each virus, virus-loaded carriers were placed in each of the 3 substrates, incubated at 4 and 20°C, and titrated at regular intervals. Serial data were analyzed using a linear regression model to calculate T-90 values (time required for 90% reduction in the virus titer). Resistance of the viruses to drying was also studied. All 4 viruses were resistant to drying. At 20°C, T-90 values of the viruses were 22 to 31 d in sterile PW and 22 to 34 d in unsterile PW. Inactivation of all 4 viruses in soil at this temperature appeared to be non-linear. T-90 values at 4°C were 102 to 182 d in sterile PW, 58 to 72 d in unsterile PW, and 30 to 48 d in soil. Viral persistence was highest in the sterile PW, followed by the unsterile PW, and was lowest in soil. There were no significant differences in the survival times between the amphibian and reptilian viruses. The results of the present study suggest that ranaviruses can survive for long periods of time in pond habitats at low temperatures.

  17. Unsuspected pseudophysiologic emphysema in chronic persistent asthma.

    PubMed

    Gelb, A F; Zamel, N

    2000-11-01

    The current literature emphasizes the role of airway remodeling in chronic persistent asthma and its putative effect on causing fixed expiratory airflow limitation. We studied 18 adults with chronic persistent asthma; 12 men, six women, age 59 +/- 15 yr (mean +/- SD) with fixed expiratory airflow obstruction. We measured lung elastic recoil and examined the mechanism of expiratory airflow limitation. Diaphragmatic strength was also measured in six asthmatics, using both sniff and partially occluded airway technique. All 18 asthmatics had markedly abnormal maximal expiratory flow-volume curves at both high and low lung volumes. Hyperinflation was present at residual volume (RV), FRC, and TLC in all subjects. Diffusing capacity was normal or elevated and lung computed tomography (CT) was normal in all 18 asthmatic subjects. There was a significant loss of lung elastic recoil in three of four asthmatics age 30 to 49, all five age 51 to 60 yr, and seven of nine age 61 to 82 yr. Maximal expiratory airflow limitation in only four elderly asthmatics and only at low lung volumes was due completely to loss of lung elastic recoil. In the others, we estimate the reduction in lung elastic recoil was responsible for 35% reduction in maximal expiratory airflow at 80% of TLC, and 55% at 70% of TLC. Despite hyperinflation, transdiaphragmatic pressures and strength were normal. The mechanisms responsible for loss of lung elastic recoil remain elusive. The high incidence of loss of lung elastic recoil in chronic persistent asthma was unexpected, and its contribution to abnormal lung function needs to be emphasized.

  18. Sequential Hybrid Procedure for Persistent Atrial Fibrillation

    PubMed Central

    Bulava, Alan; Mokracek, Ales; Hanis, Jiri; Kurfirst, Vojtech; Eisenberger, Martin; Pesl, Ladislav

    2015-01-01

    Background Catheter ablation of persistent atrial fibrillation yields an unsatisfactorily high number of failures. The hybrid approach has recently emerged as a technique that overcomes the limitations of both surgical and catheter procedures alone. Methods and Results We investigated the sequential (staged) hybrid method, which consists of a surgical thoracoscopic radiofrequency ablation procedure followed by radiofrequency catheter ablation 6 to 8 weeks later using the CARTO 3 mapping system. Fifty consecutive patients (mean age 62±7 years, 32 males) with long‐standing persistent atrial fibrillation (41±34 months) and a dilated left atrium (>45 mm) were included and prospectively followed in an unblinded registry. During the electrophysiological part of the study, all 4 pulmonary veins were found to be isolated in 36 (72%) patients and a complete box‐lesion was confirmed in 14 (28%) patients. All gaps were successfully re‐ablated. Twelve months after the completed hybrid ablation, 47 patients (94%) were in normal sinus rhythm (4 patients with paroxysmal atrial fibrillation required propafenone and 1 patient underwent a redo catheter procedure). The majority of arrhythmias recurred during the first 3 months. Beyond 12 months, there were no arrhythmia recurrences detected. The surgical part of the procedure was complicated by 7 (13.7%) major complications, while no serious adverse events were recorded during the radiofrequency catheter part of the procedure. Conclusions The staged hybrid epicardial–endocardial treatment of long‐standing persistent atrial fibrillation seems to be extremely effective in maintenance of normal sinus rhythm compared to radiofrequency catheter or surgical ablation alone. Epicardial ablation alone cannot guarantee durable transmural lesions. Clinical Trial Registration URL: www.ablace.cz Unique identifier: cz‐060520121617 PMID:25809548

  19. Bacterial persistence and expression of disease.

    PubMed Central

    Domingue, G J; Woody, H B

    1997-01-01

    A considerable body of experimental and clinical evidence supports the concept that difficult-to-culture and dormant bacteria are involved in latency of infection and that these persistent bacteria may be pathogenic. This review includes details on the diverse forms and functions of individual bacteria and attempts to make this information relevant to the care of patients. A series of experimental studies involving host-bacterium interactions illustrates the probability that most bacteria exposed to a deleterious host environment can assume a form quite different from that of a free-living bacterium. A hypothesis is offered for a kind of reproductive cycle of morphologically aberrant bacteria as a means to relate their diverse tissue forms to each other. Data on the basic biology of persistent bacteria are correlated with expression of disease and particularly the mechanisms of both latency and chronicity that typify certain infections. For example, in certain streptococcal and nocardial infections, it has been clearly established that wall-defective forms can be induced in a suitable host. These organisms can survive and persist in a latent state within the host, and they can cause pathologic responses compatible with disease. A series of cases illustrating idiopathic conditions in which cryptic bacteria have been implicated in the expression of disease is presented. These conditions include nephritis, rheumatic fever, aphthous stomatitis, idiopathic hematuria, Crohn's disease, and mycobacterial infections. By utilizing PCR, previously nonculturable bacilli have been identified in patients with Whipple's disease and bacillary angiomatosis. Koch's postulates may have to be redefined in terms of molecular data when dormant and nonculturable bacteria are implicated as causative agents of mysterious diseases. PMID:9105757

  20. A Shape-Persistent Polyphenylene Spoked Wheel.

    PubMed

    Liu, Yi; Narita, Akimitsu; Teyssandier, Joan; Wagner, Manfred; De Feyter, Steven; Feng, Xinliang; Müllen, Klaus

    2016-12-07

    A shape-persistent polyphenylene with a "spoked wheel" structure was synthesized as a subunit of an unprecedented two-dimensional polyphenylene that we name graphenylene. The synthesis was carried out through a sixfold intramolecular Yamamoto coupling of a dodecabromo-substituted dendritic polyphenylene precursor, which had a central hexaphenylbenzene unit as a template. Characterizations by NMR spectroscopy and matrix-assisted laser ionization time-of-flight mass spectrometry provided an unambiguous structural proof for the wheel-like molecule with a molar mass of 3815.4 g/mol. Remarkably, scanning tunneling microscopy visualization clearly revealed the defined spoked wheel structure of the molecule with six internal pores.

  1. Colloquium: Persistent spin textures in semiconductor nanostructures

    NASA Astrophysics Data System (ADS)

    Schliemann, John

    2017-01-01

    Device concepts in semiconductor spintronics make long spin lifetimes desirable, and the requirements put on spin control by proposals for quantum information processing are even more demanding. Unfortunately, due to spin-orbit coupling electron spins in semiconductors are generically subject to rather fast decoherence. In two-dimensional quantum wells made of zinc-blende semiconductors, however, the spin-orbit interaction can be engineered to produce persistent spin structures with extraordinarily long spin lifetimes even in the presence of disorder and imperfections. Experimental and theoretical developments on this subject for both n -doped and p -doped structures are reviewed and possible device applications are discussed.

  2. Existence of a persistent background of turbulence

    NASA Technical Reports Server (NTRS)

    Vanzandt, T. E.

    1983-01-01

    A plausible scenario for the existence of a persistent back-ground of turbulence in the free atmosphere is described. The MST radar technique is the only existing technique that can be used to describe the morphology of occurrence of turbulence as a function of altitude, wind speed, shear, weather conditions, geographical location, etc. This technique was used also to assess the degree of universality of shape and amplitude of the buoyancy wave spectrum and the relation between the buoyancy wave spectrum and turbulence.

  3. Monitoring Coastal Marshes for Persistent Saltwater Intrusion

    NASA Technical Reports Server (NTRS)

    Kalcic, Maria; Hall, Callie; Fletcher, Rose; Russell, Jeff

    2009-01-01

    Primary goal: Provide resource managers with remote sensing products that support ecosystem forecasting models requiring salinity and inundation data. Work supports the habitat-switching modules in the Coastal Louisiana Ecosystem Assessment and Restoration (CLEAR) model, which provides scientific evaluation for restoration management (Visser et al., 2008). Ongoing work to validate flooding with radar (NWRC/USGS) and enhance persistence estimates through "fusion" of MODIS and Landsat time series (ROSES A.28 Gulf of Mexico). Additional work will also investigate relationship between saltwater dielectric constant and radar returns (Radarsat) (ROSES A.28 Gulf of Mexico).

  4. Cricket: A Mapped, Persistent Object Store

    NASA Technical Reports Server (NTRS)

    Shekita, Eugene; Zwilling, Michael

    1996-01-01

    This paper describes Cricket, a new database storage system that is intended to be used as a platform for design environments and persistent programming languages. Cricket uses the memory management primitives of the Mach operating system to provide the abstraction of a shared, transactional single-level store that can be directly accessed by user applications. In this paper, we present the design and motivation for Cricket. We also present some initial performance results which show that, for its intended applications, Cricket can provide better performance than a general-purpose database storage system.

  5. Chemically engineered persistent luminescence nanoprobes for bioimaging

    PubMed Central

    Lécuyer, Thomas; Teston, Eliott; Ramirez-Garcia, Gonzalo; Maldiney, Thomas; Viana, Bruno; Seguin, Johanne; Mignet, Nathalie; Scherman, Daniel; Richard, Cyrille

    2016-01-01

    Imaging nanoprobes are a group of nanosized agents developed for providing improved contrast for bioimaging. Among various imaging probes, optical sensors capable of following biological events or progresses at the cellular and molecular levels are actually actively developed for early detection, accurate diagnosis, and monitoring of the treatment of diseases. The optical activities of nanoprobes can be tuned on demand by chemists by engineering their composition, size and surface nature. This review will focus on researches devoted to the conception of nanoprobes with particular optical properties, called persistent luminescence, and their use as new powerful bioimaging agents in preclinical assays. PMID:27877248

  6. Parsing apart the persisters: Etiological mechanisms and criminal offense patterns of moderate- and high-level persistent offenders.

    PubMed

    Amemiya, Jamie; Vanderhei, Susan; Monahan, Kathryn C

    2016-07-15

    Longitudinal investigations that have applied Moffitt's dual taxonomic framework to criminal offending have provided support for the existence of adolescent-limited and life-course persistent antisocial individuals, but have also identified additional trajectories. For instance, rather than a single persistent trajectory, studies have found both high-level and moderate-level persistent offenders. To inform theory and progress our understanding of chronic antisocial behavior, the present study used a sample of serious adolescent offenders (N =1,088) followed from middle adolescence to early adulthood (14-25 years), and examined how moderate-level persistent offenders differed from low-rate, desisting, and high-level persistent offenders. Results indicated that moderate-level persisters' etiology and criminal offense patterns were most similar to high-level persisters, but there were notable differences. Specifically, increasing levels of contextual adversity characterized both moderate-level and high-level persisting trajectories, but moderate-level persisters reported consistently lower levels of environmental risk. While both high- and moderate-level persisters committed more drug-related offenses in early adulthood compared to adolescence, moderate-level persisters engaged in lower levels of antisocial behavior across all types of criminal offenses. Taken cumulatively, the findings of this study suggest that sociocontextual interventions may be powerful in reducing both moderate- and high-level persistence in crime.

  7. Cosmic radiation exposure and persistent cognitive dysfunction

    PubMed Central

    Parihar, Vipan K.; Allen, Barrett D.; Caressi, Chongshan; Kwok, Stephanie; Chu, Esther; Tran, Katherine K.; Chmielewski, Nicole N.; Giedzinski, Erich; Acharya, Munjal M.; Britten, Richard A.; Baulch, Janet E.; Limoli, Charles L.

    2016-01-01

    The Mars mission will result in an inevitable exposure to cosmic radiation that has been shown to cause cognitive impairments in rodent models, and possibly in astronauts engaged in deep space travel. Of particular concern is the potential for cosmic radiation exposure to compromise critical decision making during normal operations or under emergency conditions in deep space. Rodents exposed to cosmic radiation exhibit persistent hippocampal and cortical based performance decrements using six independent behavioral tasks administered between separate cohorts 12 and 24 weeks after irradiation. Radiation-induced impairments in spatial, episodic and recognition memory were temporally coincident with deficits in executive function and reduced rates of fear extinction and elevated anxiety. Irradiation caused significant reductions in dendritic complexity, spine density and altered spine morphology along medial prefrontal cortical neurons known to mediate neurotransmission interrogated by our behavioral tasks. Cosmic radiation also disrupted synaptic integrity and increased neuroinflammation that persisted more than 6 months after exposure. Behavioral deficits for individual animals correlated significantly with reduced spine density and increased synaptic puncta, providing quantitative measures of risk for developing cognitive impairment. Our data provide additional evidence that deep space travel poses a real and unique threat to the integrity of neural circuits in the brain. PMID:27721383

  8. Persistent optical gating of a topological insulator

    PubMed Central

    Yeats, Andrew L.; Pan, Yu; Richardella, Anthony; Mintun, Peter J.; Samarth, Nitin; Awschalom, David D.

    2015-01-01

    The spin-polarized surface states of topological insulators (TIs) are attractive for applications in spintronics and quantum computing. A central challenge with these materials is to reliably tune the chemical potential of their electrons with respect to the Dirac point and the bulk bands. We demonstrate persistent, bidirectional optical control of the chemical potential of (Bi,Sb)2Te3 thin films grown on SrTiO3. By optically modulating a space-charge layer in the SrTiO3 substrates, we induce a persistent field effect in the TI films comparable to electrostatic gating techniques but without additional materials or processing. This enables us to optically pattern arbitrarily shaped p- and n-type regions in a TI, which we subsequently image with scanning photocurrent microscopy. The ability to optically write and erase mesoscopic electronic structures in a TI may aid in the investigation of the unique properties of the topological insulating phase. The gating effect also generalizes to other thin-film materials, suggesting that these phenomena could provide optical control of chemical potential in a wide range of ultrathin electronic systems. PMID:26601300

  9. DNA Persistence in a Sink Drain Environment

    DOE PAGES

    Winder, Eric M.; Bonheyo, George T.

    2015-07-31

    Biofilms are organized structures composed mainly of cells and extracellular polymeric substances produced by the constituent microorganisms. Ubiquitous in nature, biofilms have an innate ability to capture and retain passing material and may therefore act as natural collectors of contaminants or signatures of upstream activities. To determine the persistence and detectability of DNA passing through a sink drain environment, Bacillus anthracis strain Ames35 was cultured (6.35 x 107 CFU/mL), sterilized, and disposed of by addition to a sink drain apparatus with an established biofilm. The sink drain apparatus was sampled before and for several days after the addition of themore » sterilized B. anthracis culture to detect the presence of B. anthracis DNA. Multiple PCR primer pairs were used to screen for chromosomal and plasmid DNA with primers targeting shorter sequences showing greater amplification efficiency and success. PCR amplification and detection of target sequences indicate persistence of chromosomal DNA and plasmid DNA in the biofilm for 5 or more and 14 or more days, respectively.« less

  10. DNA Persistence in a Sink Drain Environment

    SciTech Connect

    Winder, Eric M.; Bonheyo, George T.

    2015-07-31

    Biofilms are organized structures composed mainly of cells and extracellular polymeric substances produced by the constituent microorganisms. Ubiquitous in nature, biofilms have an innate ability to capture and retain passing material and may therefore act as natural collectors of contaminants or signatures of upstream activities. To determine the persistence and detectability of DNA passing through a sink drain environment, Bacillus anthracis strain Ames35 was cultured (6.35 x 107 CFU/mL), sterilized, and disposed of by addition to a sink drain apparatus with an established biofilm. The sink drain apparatus was sampled before and for several days after the addition of the sterilized B. anthracis culture to detect the presence of B. anthracis DNA. Multiple PCR primer pairs were used to screen for chromosomal and plasmid DNA with primers targeting shorter sequences showing greater amplification efficiency and success. PCR amplification and detection of target sequences indicate persistence of chromosomal DNA and plasmid DNA in the biofilm for 5 or more and 14 or more days, respectively.

  11. Cosmic radiation exposure and persistent cognitive dysfunction.

    PubMed

    Parihar, Vipan K; Allen, Barrett D; Caressi, Chongshan; Kwok, Stephanie; Chu, Esther; Tran, Katherine K; Chmielewski, Nicole N; Giedzinski, Erich; Acharya, Munjal M; Britten, Richard A; Baulch, Janet E; Limoli, Charles L

    2016-10-10

    The Mars mission will result in an inevitable exposure to cosmic radiation that has been shown to cause cognitive impairments in rodent models, and possibly in astronauts engaged in deep space travel. Of particular concern is the potential for cosmic radiation exposure to compromise critical decision making during normal operations or under emergency conditions in deep space. Rodents exposed to cosmic radiation exhibit persistent hippocampal and cortical based performance decrements using six independent behavioral tasks administered between separate cohorts 12 and 24 weeks after irradiation. Radiation-induced impairments in spatial, episodic and recognition memory were temporally coincident with deficits in executive function and reduced rates of fear extinction and elevated anxiety. Irradiation caused significant reductions in dendritic complexity, spine density and altered spine morphology along medial prefrontal cortical neurons known to mediate neurotransmission interrogated by our behavioral tasks. Cosmic radiation also disrupted synaptic integrity and increased neuroinflammation that persisted more than 6 months after exposure. Behavioral deficits for individual animals correlated significantly with reduced spine density and increased synaptic puncta, providing quantitative measures of risk for developing cognitive impairment. Our data provide additional evidence that deep space travel poses a real and unique threat to the integrity of neural circuits in the brain.

  12. Persistent direction-changing geotropic positional nystagmus.

    PubMed

    Ichijo, Hiroaki

    2012-03-01

    The aims of the study were to clarify whether persistent direction-changing geotropic positional nystagmus contains vertical and torsional components, and to quantify the asymmetry. We analyzed nystagmus in four positions (healthy-ear-down, affected-ear-down, supine, nose-down) using three-dimensional video-oculography. Subjects were 18 patients with persistent direction-changing geotropic positional nystagmus, 16 females and 2 males, with a mean age of 55 years. Nystagmus was recorded using an infrared camera and the findings were converted to digital data. Using ImageJ, we performed three-dimensional video-oculography and measured maximum slow-phase velocity (MSV) of three components. Positional nystagmus was not purely horizontal. Eight (44%) patients revealed a vertical component (upward) and 15 (83%) patients had a torsional component in the healthy-ear-down position. Seven (39%) patients revealed a vertical component (downward) and 10 (56%) patients showed a torsional component in the nose-down position. The mean value of MSV of the horizontal component in the supine position was 9.3°/s and that in the nose-down position was 15.7°/s. The latter was significantly greater than the former (p < 0.05). Eye movements in the supine position and the nose-down position were not mirror images. These results suggest that vertical and torsional components occur from the horizontal semicircular canal, and that horizontal canal ocular reflex is influenced by input from the otolithic organs.

  13. Persistent ISR: the social network analysis connection

    NASA Astrophysics Data System (ADS)

    Bowman, Elizabeth K.

    2012-06-01

    Persistent surveillance provides decision makers with unprecedented access to multisource data collected from humans and sensor assets around the globe, yet these data exist in the physical world and provide few overt clues to meaning behind actions. In this paper we explore the recent growth in online social networking and ask the questions: 1) can these sites provide value-added information to compliment physical sensing and 2) what are the mechanisms by which these data could inform situational awareness and decision making? In seeking these answers we consider the range of options provided by Social Network Analysis (SNA), and focus especially on the dynamic nature of these networks. In our discussion we focus on the wave of reform experienced by the North African nations in early 2011 known as the Arab Spring. Demonstrators made widespread use of social networking applications to coordinate, document, and publish material to aid their cause. Unlike members of covert social networks who hide their activity and associations, these demonstrators openly posted multimedia information to coordinate activity and stimulate global support. In this paper we provide a review of SNA approaches and consider how one might track network adaptations by capturing temporal and conceptual trends. We identify opportunities and challenges for merging SNA with physical sensor output, and conclude by addressing future challenges in the persistent ISR domain with respect to SNA.

  14. Persistence of Eimeria bovis in soil.

    PubMed

    Lassen, Brian; Lepik, Triin; Bangoura, Berit

    2013-07-01

    Eimeriosis is a disease that occurs globally and often affects cattle grazing on pastures contaminated with oocysts of the pathogenic species Eimeria bovis, Eimeria zuernii or Eimeria alabamensis, respectively. Nonetheless, little is understood regarding oocyst persistence on the pasture. The study was performed in the temperate climate zone. Soil samples were spiked with 100,000 E. bovis oocysts in July 2010 or with 50,000 oocysts in October 2010, respectively, both either with our without addition of cattle faeces. The soil samples were exposed to natural environmental conditions until April 2011. A subset of the samples was analysed immediately after spiking as positive control. The oocysts were recovered by a flotation method and counted in a reading chamber. On average, 23 % of the oocysts could be recovered from the positive control. The recovery of oocysts dropped to 0.30 % of the original level in the samples prepared in July independent of the addition of faeces, whereas the oocyst count was higher in the samples prepared in October, both without (2.05 %) and with (2.64 %) faecal material. No differences were observed between presence of oocysts or oocyst counts recovered in the presence or absence of faeces. Presence of faeces had a positive influence on oocyst integrity. During the winter season, the number of oocysts in the soil was lowered under the detection limit in most samples. On the other hand, the comparatively short 3-month summer period had a significant influence on the number of persisting oocysts too.

  15. Evaluation of the Association between Persistent Organic ...

    EPA Pesticide Factsheets

    Background: Diabetes is a major threat to public health in the United States and worldwide. Understanding the role of environmental chemicals in the development or progression of diabetes is an emerging issue in environmental health.Objective: We assessed the epidemiologic literature for evidence of associations between persistent organic pollutants (POPs) and type 2 diabetes.Methods: Using a PubMed search and reference lists from relevant studies or review articles, we identified 72 epidemiological studies that investigated associations of persistent organic pollutants (POPs) with diabetes. We evaluated these studies for consistency, strengths and weaknesses of study design (including power and statistical methods), clinical diagnosis, exposure assessment, study population characteristics, and identification of data gaps and areas for future research.Conclusions: Heterogeneity of the studies precluded conducting a meta-analysis, but the overall evidence is sufficient for a positive association of some organochlorine POPs with type 2 diabetes. Collectively, these data are not sufficient to establish causality. Initial data mining revealed that the strongest positive correlation of diabetes with POPs occurred with organochlorine compounds, such as trans-nonachlor, dichlorodiphenyldichloroethylene (DDE), polychlorinated biphenyls (PCBs), and dioxins and dioxin-like chemicals. There is less indication of an association between other nonorganochlorine POPs, such as

  16. Microbial Biofilms: Persisters, Tolerance and Dosing

    NASA Astrophysics Data System (ADS)

    Cogan, N. G.

    2005-03-01

    Almost all moist surfaces are colonized by microbial biofilms. Biofilms are implicated in cross-contamination of food products, biofouling, medical implants and various human infections such as dental cavities, ulcerative colitis and chronic respiratory infections. Much of current research is focused on the recalcitrance of biofilms to typical antibiotic and antimicrobial treatments. Although the polymer component of biofilms impedes the penetration of antimicrobials through reaction-diffusion limitation, this does not explain the observed tolerance, it merely delays the action of the agent. Heterogeneities in growth-rate also slow the eradication of the bacteria since most antimicrobials are far less effective for non-growing, or slowly growing bacteria. This also does not fully describe biofilm tolerance, since heterogeneities arr primairly a result of nutrient consumption. In this investigation, we describe the formation of `persister' cells which neither grow nor die in the presence of antibiotics. We propose that the cells are of a different phenotype than typical bacterial cells and the expression of the phenotype is regulated by the growth rate and the antibiotic concentration. We describe several experiments which describe the dynamics of persister cells and which motivate a dosing protocol that calls for periodic dosing of the population. We then introduce a mathematical model, which describes the effect of such a dosing regiment and indicates that the relative dose/withdrawal times are important in determining the effectiveness of such a treatment. A reduced model is introduced and the similar behavior is demonstrated analytically.

  17. Deposition and persistence of beachcast seabird carcasses

    USGS Publications Warehouse

    van Pelt, Thomas I.; Piatt, John F.

    1995-01-01

    Following a massive wreck of guillemots (Uria aalge) in late winter and spring of 1993, we monitored the deposition and subsequent disappearance of 398 beachcast guillemot carcasses on two beaches in Resurrection Bay, Alaska, during a 100 day period. Deposition of carcasses declined logarithmically with time after the original event. Since fresh carcasses were more likely to be removed between counts than older carcasses, persistence rates increased logarithmically over time. Scavenging appeared to be the primary cause of carcass removal, followed by burial in beach debris and sand. Along-shore transport was negligible. We present an equation which estimates the number of carcasses deposited at time zero from beach surveys conducted some time later, using non-linear persistence rates that are a function of time. We use deposition rates to model the accumulation of beached carcasses, accounting for further deposition subsequent to the original event. Finally, we present a general method for extrapolating from a single count the number of carcasses cumulatively deposited on surveyed beaches, and discuss how our results can be used to assess the magnitude of mass seabird mortality events from beach surveys.

  18. Measuring persistence: A literature review focusing on methodological issues

    SciTech Connect

    Wolfe, A.K.; Brown, M.A.; Trumble, D.

    1995-03-01

    This literature review was conducted as part of a larger project to produce a handbook on the measurement of persistence. The past decade has marked the development of the concept of persistence and a growing recognition that the long-term impacts of demand-side management (DSM) programs warrant careful assessment. Although Increasing attention has been paid to the topic of persistence, no clear consensus has emerged either about its definition or about the methods most appropriate for its measurement and analysis. This project strives to fill that gap by reviewing the goals, terminology, and methods of past persistence studies. It was conducted from the perspective of a utility that seeks to acquire demand-side resources and is interested in their long-term durability; it was not conducted from the perspective of the individual consumer. Over 30 persistence studies, articles, and protocols were examined for this report. The review begins by discussing the underpinnings of persistence studies: namely, the definitions of persistence and the purposes of persistence studies. Then. it describes issues relevant to both the collection and analysis of data on the persistence of energy and demand savings. Findings from persistence studies also are summarized. Throughout the review, four studies are used repeatedly to illustrate different methodological and analytical approaches to persistence so that readers can track the data collection. data analysis, and findings of a set of comprehensive studies that represent alternative approaches.

  19. A study of the predictors of persistence in stalking situations.

    PubMed

    McEwan, Troy E; Mullen, Paul E; MacKenzie, Rachel

    2009-04-01

    Stalkers engaging in persistent campaigns of harassment have the potential to cause immense harm to their victims and themselves. Being able to estimate which stalkers are likely to persist longest is important to clinicians dealing with both perpetrators and victims. This study of 200 stalkers investigated characteristics of the stalkers and their behaviour that were associated with increased persistence. Logistic regression models were developed to predict low, moderate, and highly persistent stalking. The results supported previous research indicating that the type of prior relationship between stalker and victim is strongly associated with persistence, with prior acquaintances the most persistent, and strangers least. Being aged over 30, sending the victim unsolicited materials, and having an intimacy seeking or resentful motivation was also associated with greater persistence, as was the presence of psychosis.

  20. Role of adult hippocampal neurogenesis in persistent pain.

    PubMed

    Apkarian, A Vania; Mutso, Amelia A; Centeno, Maria V; Kan, Lixin; Wu, Melody; Levinstein, Marjorie; Banisadr, Ghazal; Gobeske, Kevin T; Miller, Richard J; Radulovic, Jelena; Hen, René; Kessler, John A

    2016-02-01

    The full role of adult hippocampal neurogenesis (AHN) remains to be determined, yet it is implicated in learning and emotional functions, and is disrupted in negative mood disorders. Recent evidence indicates that AHN is decreased in persistent pain consistent with the idea that chronic pain is a major stressor, associated with negative moods and abnormal memories. Yet, the role of AHN in development of persistent pain has remained unexplored. In this study, we test the influence of AHN in postinjury inflammatory and neuropathic persistent pain-like behaviors by manipulating neurogenesis: pharmacologically through intracerebroventricular infusion of the antimitotic AraC; ablation of AHN by x-irradiation; and using transgenic mice with increased or decreased AHN. Downregulating neurogenesis reversibly diminished or blocked persistent pain; oppositely, upregulating neurogenesis led to prolonged persistent pain. Moreover, we could dissociate negative mood from persistent pain. These results suggest that AHN-mediated hippocampal learning mechanisms are involved in the emergence of persistent pain.

  1. Role of adult hippocampal neurogenesis in persistent pain

    PubMed Central

    Apkarian, A. Vania; Mutso, Amelia A.; Centeno, Maria V.; Kan, Lixin; Wu, Melody; Levinstein, Marjorie; Banisadr, Ghazal; Gobeske, Kevin T.; Miller, Richard J.; Radulovic, Jelena; Hen, René; Kessler, John A.

    2016-01-01

    The full role of adult hippocampal neurogenesis (AHN) remains to be determined, yet it is implicated in learning and emotional functions, and is disrupted in negative mood disorders. Recent evidence indicates that AHN is decreased in persistent pain consistent with the idea that chronic pain is a major stressor, associated with negative moods and abnormal memories. Yet, the role of AHN in development of persistent pain has remained unexplored. In this study, we test the influence of AHN in postinjury inflammatory and neuropathic persistent pain-like behaviors by manipulating neurogenesis: pharmacologically through intracerebroventricular infusion of the antimitotic AraC; ablation of AHN by x-irradiation; and using transgenic mice with increased or decreased AHN. Downregulating neurogenesis reversibly diminished or blocked persistent pain; oppositely, upregulating neurogenesis led to prolonged persistent pain. Moreover, we could dissociate negative mood from persistent pain. These results suggest that AHN-mediated hippocampal learning mechanisms are involved in the emergence of persistent pain. PMID:26313405

  2. Perceptions of Persistence: Why Underprepared Community College Students Are Not Persisting

    ERIC Educational Resources Information Center

    Maue, Lea C.

    2012-01-01

    The purpose of this study was to illuminate the barriers to persistence underprepared students at the community college experience after the initial successful completion of one semester. A qualitative interview study, grounded in phenomenology, was implemented. Participants were identified through a process of purposeful selection, which included…

  3. Persistent Identifiers, Discoverability and Open Science (Communication)

    NASA Astrophysics Data System (ADS)

    Murphy, Fiona; Lehnert, Kerstin; Hanson, Brooks

    2016-04-01

    Early in 2016, the American Geophysical Union announced it was incorporating ORCIDs into its submission workflows. This was accompanied by a strong statement supporting the use of other persistent identifiers - such as IGSNs, and the CrossRef open registry 'funding data'. This was partly in response to funders' desire to track and manage their outputs. However the more compelling argument, and the reason why the AGU has also signed up to the Center for Open Science's Transparency and Openness Promotion (TOP) Guidelines (http://cos.io/top), is that ultimately science and scientists will be the richer for these initiatives due to increased opportunities for interoperability, reproduceability and accreditation. The AGU has appealed to the wider community to engage with these initiatives, recognising that - unlike the introduction of Digital Object Identifiers (DOIs) for articles by CrossRef - full, enriched use of persistent identifiers throughout the scientific process requires buy-in from a range of scholarly communications stakeholders. At the same time, across the general research landscape, initiatives such as Project CRediT (contributor roles taxonomy), Publons (reviewer acknowledgements) and the forthcoming CrossRef DOI Event Tracker are contributing to our understanding and accreditation of contributions and impact. More specifically for earth science and scientists, the cross-functional Coalition for Publishing Data in the Earth and Space Sciences (COPDESS) was formed in October 2014 and is working to 'provide an organizational framework for Earth and space science publishers and data facilities to jointly implement and promote common policies and procedures for the publication and citation of data across Earth Science journals'. Clearly, the judicious integration of standards, registries and persistent identifiers such as ORCIDs and International Geo Sample Numbers (IGSNs) to the research and research output processes is key to the success of this venture

  4. ATP-Dependent Persister Formation in Escherichia coli

    PubMed Central

    Shan, Yue; Brown Gandt, Autumn; Rowe, Sarah E.; Deisinger, Julia P.; Conlon, Brian P.

    2017-01-01

    ABSTRACT Persisters are dormant variants that form a subpopulation of cells tolerant to antibiotics. Persisters are largely responsible for the recalcitrance of chronic infections to therapy. In Escherichia coli, one widely accepted model of persister formation holds that stochastic accumulation of ppGpp causes activation of the Lon protease that degrades antitoxins; active toxins then inhibit translation, resulting in dormant, drug-tolerant persisters. We found that various stresses induce toxin-antitoxin (TA) expression but that induction of TAs does not necessarily increase persisters. The 16S rRNA promoter rrnB P1 was proposed to be a persister reporter and an indicator of toxin activation regulated by ppGpp. Using fluorescence-activated cell sorting (FACS), we confirmed the enrichment for persisters in the fraction of rrnB P1-gfp dim cells; however, this is independent of toxin-antitoxins. rrnB P1 is coregulated by ppGpp and ATP. We show that rrnB P1 can report persisters in a relA/spoT deletion background, suggesting that rrnB P1 is a persister marker responding to ATP. Consistent with this finding, decreasing the level of ATP by arsenate treatment causes drug tolerance. Lowering ATP slows translation and prevents the formation of DNA double-strand breaks upon fluoroquinolone treatment. We conclude that variation in ATP levels leads to persister formation by decreasing the activity of antibiotic targets. PMID:28174313

  5. Dormancy Is Not Necessary or Sufficient for Bacterial Persistence

    PubMed Central

    Orman, Mehmet A.

    2013-01-01

    The antibiotic tolerances of bacterial persisters have been attributed to transient dormancy. While persisters have been observed to be growth inhibited prior to antibiotic exposure, we sought to determine whether such a trait was essential to the phenotype. Furthermore, we sought to provide direct experimental evidence of the persister metabolic state so as to determine whether the common assumption of metabolic inactivity was valid. Using fluorescence-activated cell sorting (FACS), a fluorescent indicator of cell division, a fluorescent measure of metabolic activity, and persistence assays, we found that bacteria that are rapidly growing prior to antibiotic exposure can give rise to persisters and that a lack of replication or low metabolic activity prior to antibiotic treatment simply increases the likelihood that a cell is a persister. Interestingly, a lack of significant growth or metabolic activity does not guarantee persistence, as the majority of even “dormant” subpopulations (>99%) were not persisters. These data suggest that persistence is far more complex than dormancy and point to additional characteristics needed to define the persister phenotype. PMID:23629720

  6. In Vivo Persistence of Human Rhinoviruses in Immunosuppressed Patients

    PubMed Central

    Engelmann, Ilka; Dewilde, Anny; Lazrek, Mouna; Batteux, Mathilde; Hamissi, Aminati; Yakoub-Agha, Ibrahim; Hober, Didier

    2017-01-01

    Several species of the genus Enterovirus cause persistent infections in humans. Human rhinovirus (HRV) infections are generally self-limiting but occasionally persistent infections have been described. This study aimed to identify persistent HRV infections and investigate the clinical and virologic characteristics of patients with persistent infections. From January 2012 to March 2015, 3714 respiratory specimens from 2608 patients were tested for respiratory viruses by using a multiplex reverse transcription–polymerase chain reaction. A retrospective study was performed. Patients with at least two specimens positive for HRV/enterovirus taken 45 days or longer apart were identified and the HRV/enteroviruses were typed. Patients with persistent infection were compared to patients with reinfection and patients with cleared infection. Phylogenetic analysis of the viral protein(VP)4/VP2 region was performed. 18 patients with persistent HRV/enterovirus infection were identified. Minimum median duration of persistence was 92 days (range 50–455 days). All but one patients with persistence were immunosuppressed. Immunosuppression and hematologic disorders were more frequent in patients with persistence (n = 18) than in patients with reinfection (n = 33) and with cleared infection (n = 25) (p = 0.003 and p = 0.001, respectively). In conclusion, this retrospective study identified HRV persistence in vivo which occurred mainly in immunosuppressed patients. PMID:28151988

  7. Learning rules and persistence of dendritic spines.

    PubMed

    Kasai, Haruo; Hayama, Tatsuya; Ishikawa, Motoko; Watanabe, Satoshi; Yagishita, Sho; Noguchi, Jun

    2010-07-01

    Structural plasticity of dendritic spines underlies learning, memory and cognition in the cerebral cortex. We here summarize fifteen rules of spine structural plasticity, or 'spine learning rules.' Together, they suggest how the spontaneous generation, selection and strengthening (SGSS) of spines represents the physical basis for learning and memory. This SGSS mechanism is consistent with Hebb's learning rule but suggests new relations between synaptic plasticity and memory. We describe the cellular and molecular bases of the spine learning rules, such as the persistence of spine structures and the fundamental role of actin, which polymerizes to form a 'memory gel' required for the selection and strengthening of spine synapses. We also discuss the possible link between transcriptional and translational regulation of structural plasticity. The SGSS mechanism and spine learning rules elucidate the integral nature of synaptic plasticity in neuronal network operations within the actual brain tissue.

  8. Phosphors with long-persistent green phosphorescence

    NASA Technical Reports Server (NTRS)

    Yen, William M (Inventor); Jia, Weiyi (Inventor); Lu, Lizhu (Inventor); Yuan, Huabiao (Inventor)

    2001-01-01

    This invention relates to phosphors including long-persistence green phosphors. Phosphors of the invention are represented by the general formula: M.sub.k Al.sub.2 O.sub.4 :2xEu.sup.2+,2yR.sup.3+ wherein k-1-2x-2y, x is a number ranging from about 0.0001 to about 0.05, y is a number ranging from about x to about 3x, M is an alkaline earth metal, and R.sup.3+ is one or more trivalent metal ions. Phosphors of this invention include powders, ceramics, single crystals and single crystal fibers. A method of manufacturing improved phosphors and a method of manufacturing single crystal phosphors are also provided.

  9. Chatter detection in turning using persistent homology

    NASA Astrophysics Data System (ADS)

    Khasawneh, Firas A.; Munch, Elizabeth

    2016-03-01

    This paper describes a new approach for ascertaining the stability of stochastic dynamical systems in their parameter space by examining their time series using topological data analysis (TDA). We illustrate the approach using a nonlinear delayed model that describes the tool oscillations due to self-excited vibrations in turning. Each time series is generated using the Euler-Maruyama method and a corresponding point cloud is obtained using the Takens embedding. The point cloud can then be analyzed using a tool from TDA known as persistent homology. The results of this study show that the described approach can be used for analyzing datasets of delay dynamical systems generated both from numerical simulation and experimental data. The contributions of this paper include presenting for the first time a topological approach for investigating the stability of a class of nonlinear stochastic delay equations, and introducing a new application of TDA to machining processes.

  10. PERSISTENT WRIST PAIN IN A MATURE GOLFER

    PubMed Central

    Hazle, Charles

    2012-01-01

    Clients presenting with ulnar-sided wrist pain can provide diagnostic and management challenges for physical therapists. Symptoms in this region may originate from multiple structures. Integration of clinical examination and diagnostic imaging results is often required for optimal decision-making and patient management. To obtain the most informative imaging results, practitioners need an understanding of injury patterns and their detection by various imaging modalities. This case describes a mature golfer who presented with persistent ulnar-sided wrist pain and was eventually determined to have a fracture of the hook of the hamate accompanied by neighboring soft tissue involvement also contributing to his symptom complex. His history and the diagnostic process are detailed along with a brief discussion of his subsequent management post-operatively. Level of Evidence: 5 (Single Case Report) PMID:22893862

  11. Persistence of orographic mixed-phase clouds

    NASA Astrophysics Data System (ADS)

    Lohmann, U.; Henneberger, J.; Henneberg, O.; Fugal, J. P.; Bühl, J.; Kanji, Z. A.

    2016-10-01

    Mixed-phase clouds (MPCs) consist of ice crystals and supercooled water droplets at temperatures between 0 and approximately -38°C. They are thermodynamically unstable because the saturation vapor pressure over ice is lower than that over supercooled liquid water. Nevertheless, long-lived MPCs are ubiquitous in the Arctic. Here we show that persistent MPCs are also frequently found in orographic terrain, especially in the Swiss Alps, when the updraft velocities are high enough to exceed saturation with respect to liquid water allowing simultaneous growth of supercooled liquid droplets and ice crystals. Their existence is characterized by holographic measurements of cloud particles obtained at the high-altitude research station Jungfraujoch during spring 2012 and winter 2013 and simulations with the regional climate model COSMO (Consortium of Small-Scale Modeling).

  12. Low latency and persistent data storage

    DOEpatents

    Fitch, Blake G; Franceschini, Michele M; Jagmohan, Ashish; Takken, Todd

    2014-11-04

    Persistent data storage is provided by a computer program product that includes computer program code configured for receiving a low latency store command that includes write data. The write data is written to a first memory device that is implemented by a nonvolatile solid-state memory technology characterized by a first access speed. It is acknowledged that the write data has been successfully written to the first memory device. The write data is written to a second memory device that is implemented by a volatile memory technology. At least a portion of the data in the first memory device is written to a third memory device when a predetermined amount of data has been accumulated in the first memory device. The third memory device is implemented by a nonvolatile solid-state memory technology characterized by a second access speed that is slower than the first access speed.

  13. Low latency and persistent data storage

    DOEpatents

    Fitch, Blake G; Franceschini, Michele M; Jagmohan, Ashish; Takken, Todd E

    2014-02-18

    Persistent data storage is provided by a method that includes receiving a low latency store command that includes write data. The write data is written to a first memory device that is implemented by a nonvolatile solid-state memory technology characterized by a first access speed. It is acknowledged that the write data has been successfully written to the first memory device. The write data is written to a second memory device that is implemented by a volatile memory technology. At least a portion of the data in the first memory device is written to a third memory device when a predetermined amount of data has been accumulated in the first memory device. The third memory device is implemented by a nonvolatile solid-state memory technology characterized by a second access speed that is slower than the first access speed.

  14. Toxic contaminants in the environment: Persistent organochlorines

    SciTech Connect

    1998-12-31

    Indicators in this bulletin are part of a national set of environmental indicators designed to provide a profile of the state of Canada`s environment and measure progress towards sustainable development. Some toxic substances associated with industry are of particular concern because of adverse effects on wildlife and humans. One of these groups is persistent organochlorines and this bulletin focuses on levels of these in biota. Organochlorines are a family of chemicals that have been used as insecticides, such as DDT, or as industrial chemicals, such as PCBs. Polychlorinated dioxins and furans are by-products of certain industrial processes. This document looks at these organochlorines and the use of wildlife indicators. It then provides more specific information on contaminant levels in double-crested cormorant eggs -- DDE and PCBs, or dioxins and furans.

  15. The persistent impact of incidental experience.

    PubMed

    Wilder, Matthew H; Jones, Matt; Ahmed, Alaa A; Curran, Tim; Mozer, Michael C

    2013-12-01

    As we perform daily activities--driving to work, unlocking the office door, or grabbing a coffee cup--our actions seem automatic and preprogrammed. Nonetheless, routine, well-practiced behavior is continually modulated by incidental experience: In repetitive experimental tasks, recent (~4) trials reliably influence performance and action choice. Psychological theories downplay the significance of sequential effects, explaining them as rapidly decaying perturbations of behavior, with no long-term consequences. We challenged this traditional perspective in two experiments designed to probe the impact of more distant experience, finding evidence for effects spanning up to a thousand intermediate trials. We present a normative theory in which these persistent effects reflect optimal adaptation to a dynamic environment exhibiting varying rates of change. The theory predicts a heavy-tailed decaying influence of past experience, consistent with our data, and suggests that individual incidental experiences are catalogued in a temporally extended memory utilized in order to optimize subsequent behavior.

  16. [Pyometra and persistent hymen in an alpaca].

    PubMed

    Egloff, C; Gerspach, C; Rütten, M; Dettwiler, M; Reichler, I; Bleul, U

    2013-01-01

    A 3-year-old female alpaca was referred to the hospital because of tenesmus. Clinical examination revealed a habitual vaginal prolapse with tenesmus during urination and defecation. On vaginoscopic examination a persistent hymen was detected. Ultrasonography of the caudal abdomen showed an echogenic fluid-filled uterus. A diagnostic laparotomy led to diagnosis of pyometra. Following ovariohysterectomy, the recovery was uneventful. One and a half years later the alpaca was again admitted to the hospital because of colic. Based on the findings, a tentative prognosis was provided and the alpaca was euthanized at the request of the owner. At necropsy, a haemorrhagic infarction of a jejunal loop was found due to incarceration in a fibrous adhesion between the vaginal stump and small intestine.

  17. Introduction and persistence of tularemia in Bulgaria

    PubMed Central

    Myrtennäs, Kerstin; Marinov, Krustyu; Johansson, Anders; Niemcewicz, Marcin; Karlsson, Edvin; Byström, Mona; Forsman, Mats

    2016-01-01

    Introduction Outbreaks of the zoonotic disease tularemia occurred in north-east Bulgaria in the 1960s. Then came 30 years of epidemiological silence until new outbreaks occurred in west Bulgaria in the 1990s. To investigate how bacterial strains of Francisella tularensis causing tularemia in wildlife and humans in the 1960s and the 1990s were related, we explored their genetic diversity. Material and methods Ten F. tularensis genomes from the 1960s (n=3) and the 1990s (n=7) were sequenced, assigned to canonical single-nucleotide polymorphism (canSNP) clades, and compared to reference genomes. We developed four new canSNP polymerase chain reaction (PCR) assays based on the genome sequence information. Results and discussion The genetic analysis showed that the outbreaks in the 1960s as well as in the 1990s involved multiple clones and new genetic diversity. The smallest genetic difference found between any of the Bulgarian strains was five SNPs between the strains L2 and 81 isolated 43 years apart, indicating that F. tularensis may persist locally over long time periods without causing outbreaks. The existence of genetically highly similar strain-pairs isolated the same year in the same area from different hosts supports a hypothesis of local expansion of clones during outbreaks. Close relationship (two SNPs) was found between one strain isolated 1961 in northeast Bulgaria and one strain isolated 5 years before in USSR. Historical data coinciding with the actual time point describe the introduction of water rats from USSR into the Bulgarian outbreak area, which may explain the close genetic relationship and the origin of the outbreak. Conclusion Genome analysis of strains from two outbreaks in the 1960s and the 1990s provided valuable information on the genetic diversity and persistence of F. tularensis in Bulgaria. PMID:27790972

  18. Problems in data registration for persistent sensing

    NASA Astrophysics Data System (ADS)

    Jwa, Sangil; Özgüner, Ümit

    2008-04-01

    Persistent sensing by Unmanned Airborne Vehicles (UAVs) has brought up challenging issues including multi-scale analysis, multi-modal sensor fusion, and scene localization. As for the first issue, the multi-scale and multi-resolution issues occur when a mobile sensor changes altitudes or two different sensors with the same camera provide any redundant images from different altitudes. To overcome these issues, we first focus on collecting invariant feature data from the multi-resolution representation of a high resolution image. Recently, an information-theoretic matching criterion has been developed for robust data registration without any knowledge of feature correspondence. This criterion is used as an intelligent computing algorithm of choosing a good scale-representation that helps to find an unknown scaling factor between two different and redundant measurements. As for the second issue of multi-modal sensor fusion, we observe that Electro-optical (EO) and Infrared (IR) images in the DARPA VIVID database have an inherent scaling-difference, even though the different modalities come from the two fixed EO and IR sensors attached on the same mobile sensor. Here we provide a new experimental result of multi-modal data fusion that successfully combines complementary information via the process of data refinement. The recovered transformation reveals one of the fundamental characteristics of the two different modalities. The last issue of scene localization is required for identifying the scene visited before. In this paper, we demonstrate the trajectory of the mobile sensor based only on the extracted transformations (not relying on any telemetric data of the mobile sensor which is not available persistently) by projecting the center locations of image measurements onto the two dimensional reference coordinate.

  19. Development of Persister-FACSeq: a method to massively parallelize quantification of persister physiology and its heterogeneity

    PubMed Central

    Henry, Theresa C.; Brynildsen, Mark P.

    2016-01-01

    Bacterial persisters are thought to underlie the relapse of chronic infections. Knowledge of persister physiology would illuminate avenues for therapeutic intervention; however, such knowledge has remained elusive because persisters have yet to be segregated from other cell types to sufficient purity. This technical hurdle has stymied progress toward understanding persistence. Here we developed Persister-FACSeq, which is a method that uses fluorescence-activated cell sorting, antibiotic tolerance assays, and next generation sequencing to interrogate persister physiology and its heterogeneity. As a proof-of-concept, we used Persister-FACSeq on a library of reporters to study gene expression distributions in non-growing Escherichia coli, and found that persistence to ofloxacin is inversely correlated with the capacity of non-growing cells to synthesize protein. Since Persister-FACSeq can be applied to study persistence to any antibiotic in any environment for any bacteria that can harbor a fluorescent reporter, we anticipate that it will yield unprecedented knowledge of this detrimental phenotype. PMID:27142337

  20. People underestimate the value of persistence for creative performance.

    PubMed

    Lucas, Brian J; Nordgren, Loran F

    2015-08-01

    Across 7 studies, we investigated the prediction that people underestimate the value of persistence for creative performance. Across a range of creative tasks, people consistently underestimated how productive they would be while persisting (Studies 1-3). Study 3 found that the subjectively experienced difficulty, or disfluency, of creative thought accounted for persistence undervaluation. Alternative explanations based on idea quality (Studies 1-2B) and goal setting (Study 4) were considered and ruled out and domain knowledge was explored as a boundary condition (Study 5). In Study 6, the disfluency of creative thought reduced people's willingness to invest in an opportunity to persist, resulting in lower financial performance. This research demonstrates that persistence is a critical determinant of creative performance and that people may undervalue and underutilize persistence in everyday creative problem solving.

  1. Bacterial persistence induced by salicylate via reactive oxygen species

    PubMed Central

    Wang, Tiebin; El Meouche, Imane; Dunlop, Mary J.

    2017-01-01

    Persisters are phenotypic variants of regular cells that exist in a dormant state with low metabolic activity, allowing them to exhibit high tolerance to antibiotics. Despite increasing recognition of their role in chronic and recalcitrant infections, the mechanisms that induce persister formation are not fully understood. In this study, we find that salicylate can induce persister formation in Escherichia coli via generation of reactive oxygen species (ROS). Salicylate-induced ROS cause a decrease in the membrane potential, reduce metabolism and lead to an increase in persistence. These effects can be recovered by culturing cells in the presence of a ROS quencher or in an anaerobic environment. Our findings reveal that salicylate-induced oxidative stress can lead to persistence, suggesting that ROS, and their subsequent impact on membrane potential and metabolism, may play a broad role in persister formation. PMID:28281556

  2. Measuring persistence in time series of temperature anomalies

    NASA Astrophysics Data System (ADS)

    Triacca, Umberto; Pasini, Antonello; Attanasio, Alessandro

    2014-11-01

    Studies on persistence are important for the clarification of statistical properties of the analyzed time series and for understanding the dynamics of the systems which create these series. In climatology, the analysis of the autocorrelation function has been the main tool to investigate the persistence of a time series. In this paper, we propose to use a more sophisticated econometric instrument. Using this tool, we obtain an estimate of the persistence in global land and ocean and hemispheric temperature time series.

  3. Unilateral persistent hyperplastic tunica vasculosa lentis and persistent hyperplastic primary vitreous in a rabbit.

    PubMed

    Boillot, Thomas; Graille, Mélanie; Williams, David; Rosolen, Serge G

    2015-11-01

    A 3-month wild rabbit was presented for examination of ocular opacities in the left eye. A complete bilateral ocular examination including slit-lamp examination, indirect ophthalmoscopy, tonometry, and ultrasound biomicroscopy was performed. Biomicroscopy of the lens of the left eye showed a retrolental fibrovascular membrane causing leukocoria. The opacity prevented biomicroscopy of the vitreous and funduscopy OS. No other disorder was present in either eye. Ultrasound examination did not show any difference between the right and left eye. Histopathological examination showed a 50-μm thick, preretinal, retrolental, nonpigmented, fibrovascular tissue. Posterior synechiae were present, but no other lesion of the posterior segment was found in this eye. These ocular abnormalities are consistent with a persistent hyperplastic tunica vasculosa lentis and persistent hyperplastic primary vitreous (PHTVL/PHPV), similar to those described in other species.

  4. Persistent RNA virus infections: do PAMPS drive chronic disease?

    PubMed

    McCarthy, Mary K; Morrison, Thomas E

    2017-02-16

    Chronic disease associated with persistent RNA virus infections represents a key public health concern. While human immunodeficiency virus-1 and hepatitis C virus are perhaps the most well-known examples of persistent RNA viruses that cause chronic disease, evidence suggests that many other RNA viruses, including re-emerging viruses such as chikungunya virus, Ebola virus and Zika virus, establish persistent infections. The mechanisms by which RNA viruses drive chronic disease are poorly understood. Here, we discuss how the persistence of viral RNA may drive chronic disease manifestations via the activation of RNA sensing pathways.

  5. Food web persistence is enhanced by non-trophic interactions.

    PubMed

    Hammill, Edd; Kratina, Pavel; Vos, Matthijs; Petchey, Owen L; Anholt, Bradley R

    2015-06-01

    The strength of interspecific interactions is often proposed to affect food web stability, with weaker interactions increasing the persistence of species, and food webs as a whole. However, the mechanisms that modify interaction strengths, and their effects on food web persistence are not fully understood. Using food webs containing different combinations of predator, prey, and nonprey species, we investigated how predation risk of susceptible prey is affected by the presence of species not directly trophically linked to either predators or prey. We predicted that indirect alterations to the strength of trophic interactions translate to changes in persistence time of extinction-prone species. We assembled interaction webs of protist consumers and turbellarian predators with eight different combinations of prey, predators and nonprey species, and recorded abundances for over 130 prey generations. Persistence of predation-susceptible species was increased by the presence of nonprey. Furthermore, multiple nonprey species acted synergistically to increase prey persistence, such that persistence was greater than would be predicted from the dynamics of simpler food webs. We also found evidence suggesting increased food web complexity may weaken interspecific competition, increasing persistence of poorer competitors. Our results demonstrate that persistence times in complex food webs cannot be predicted from the dynamics of simplified systems, and that species not directly involved in consumptive interactions likely play key roles in maintaining persistence. Global species diversity is currently declining at an unprecedented rate and our findings reveal that concurrent loss of species that modify trophic interactions may have unpredictable consequences for food web stability.

  6. Versatile persistence pathways for pathogens of animals and plants.

    PubMed

    Vereecke, Danny; Cornelis, Karen; Temmerman, Wim; Holsters, Marcelle; Goethals, Koen

    2002-11-01

    The glyoxylate cycle and the glycine cleavage system are part of conserved metabolic pathways involved in the chronic persistence of microorganisms in animal hosts. In the chromosome of the plant pathogen Rhodococcus fascians, the vic locus has been identified as a region containing genes essential for persistence inside induced leafy galls. Sequence analysis showed that this 18-kb locus is syntenic with chromosomal regions of Mycobacterium species that encompass the 'persistence' loci of these mammalian pathogens. Hence, the ability to switch diet inside the host appears to be governed by 'persistence' enzymes that are conserved between pathogens of animals and plants.

  7. Analyzing persister physiology with fluorescence activated cell sorting

    PubMed Central

    Orman, Mehmet A.; Henry, Theresa C.; DeCoste, Christina J.; Brynildsen, Mark P.

    2016-01-01

    Bacterial persisters are phenotypic variants that exhibit an impressive ability to tolerate antibiotics. Persisters are hypothesized to cause relapse infections, and therefore, understanding their physiology may lead to novel therapeutics to treat recalcitrant infections. However, persisters have yet to be isolated due to their low abundance, transient nature, and similarity to the more highly abundant viable but non-culturable cells (VBNCs), resulting in limited knowledge of their phenotypic state. This technical hurdle has been addressed through the use of fluorescence activated cell sorting (FACS) and quantification of persister levels in the resulting sorted fractions. These assays provide persister phenotype distributions, which can be compared to the phenotype distributions of the entire population, and can also be used to examine persister heterogeneity. Here we describe two detailed protocols for analysis of persister physiology with FACS. One protocol assays the metabolic state of persisters using a fluorescent metabolic stain, whereas the other assays the growth state of persisters with use of a fluorescent protein. PMID:26468102

  8. Diffuse persistent interstitial pulmonary emphysema treated by lobectomy.

    PubMed

    Matta, Reva; Matta, Judy; Hage, Pierre; Nassif, Yolla; Mansour, Nabil; Diab, Nabil

    2011-10-01

    Persistent interstitial pulmonary emphysema is a rare condition that occurs in preterm infants on mechanical ventilation, characterized by abnormal accumulation of air in the pulmonary interstitium, due to disruption of the basement membrane. Diffuse persistent interstitial pulmonary emphysema is observed when small cysts are noted in all lobes of the lung. The management of infants suffering from diffuse persistent interstitial pulmonary emphysema varies according to severity and stability of the patient, being either conservative treatment or aggressive surgical treatment by pneumonectomy. We report a case of an unstable patient with diffuse persistent interstitial pulmonary emphysema successfully treated by lobectomy as a form of conservative surgical approach.

  9. Diagnosing Intermittent and Persistent Faults using Static Bayesian Networks

    NASA Technical Reports Server (NTRS)

    Megshoel, Ole Jakob

    2010-01-01

    Both intermittent and persistent faults may occur in a wide range of systems. We present in this paper the introduction of intermittent fault handling techniques into ProDiagnose, an algorithm that previously only handled persistent faults. We discuss novel algorithmic techniques as well as how our static Bayesian networks help diagnose, in an integrated manner, a range of intermittent and persistent faults. Through experiments with data from the ADAPT electrical power system test bed, generated as part of the Second International Diagnostic Competition (DXC-10), we show that this novel variant of ProDiagnose diagnoses intermittent faults accurately and quickly, while maintaining strong performance on persistent faults.

  10. Peritraumatic versus persistent dissociation in acute stress disorder.

    PubMed

    Panasetis, Paula; Bryant, Richard A

    2003-12-01

    The DSM-IV definition of acute stress disorder (ASD) regards dissociation that occurs during a trauma (peritraumatic dissociation) comparably to persistent dissociation. This study investigated the relative contributions of peritraumatic dissociation and persistent dissociation to acute posttraumatic stress reactions. Civilian trauma (N = 53) survivors with either acute stress disorder (ASD), subclinical ASD, or no ASD were administered modified versions of the Peritraumatic Dissociative Experiences Questionnaire that indexed both dissociation during the trauma and dissociation at the time of assessment. Persistent dissociation was more strongly associated with ASD severity and intrusive symptoms than peritraumatic dissociation. These results are consistent with the proposition that persistent, rather than peritraumatic, dissociation is associated with posttraumatic psychopathology.

  11. Measles virus induces persistent infection by autoregulation of viral replication

    PubMed Central

    Doi, Tomomitsu; Kwon, Hyun-Jeong; Honda, Tomoyuki; Sato, Hiroki; Yoneda, Misako; Kai, Chieko

    2016-01-01

    Natural infection with measles virus (MV) establishes lifelong immunity. Persistent infection with MV is likely involved in this phenomenon, as non-replicating protein antigens never induce such long-term immunity. Although MV establishes stable persistent infection in vitro and possibly in vivo, the mechanism by which this occurs is largely unknown. Here, we demonstrate that MV changes the infection mode from lytic to non-lytic and evades the innate immune response to establish persistent infection without viral genome mutation. We found that, in the persistent phase, the viral RNA level declined with the termination of interferon production and cell death. Our analysis of viral protein dynamics shows that during the establishment of persistent infection, the nucleoprotein level was sustained while the phosphoprotein and large protein levels declined. The ectopic expression of nucleoprotein suppressed viral replication, indicating that viral replication is self-regulated by nucleoprotein accumulation during persistent infection. The persistently infected cells were able to produce interferon in response to poly I:C stimulation, suggesting that MV does not interfere with host interferon responses in persistent infection. Our results may provide mechanistic insight into the persistent infection of this cytopathic RNA virus that induces lifelong immunity. PMID:27883010

  12. Persistence and resistance as complementary bacterial adaptations to antibiotics.

    PubMed

    Vogwill, T; Comfort, A C; Furió, V; MacLean, R C

    2016-06-01

    Bacterial persistence represents a simple of phenotypic heterogeneity, whereby a proportion of cells in an isogenic bacterial population can survive exposure to lethal stresses such as antibiotics. In contrast, genetically based antibiotic resistance allows for continued growth in the presence of antibiotics. It is unclear, however, whether resistance and persistence are complementary or alternative evolutionary adaptations to antibiotics. Here, we investigate the co-evolution of resistance and persistence across the genus Pseudomonas using comparative methods that correct for phylogenetic nonindependence. We find that strains of Pseudomonas vary extensively in both their intrinsic resistance to antibiotics (ciprofloxacin and rifampicin) and persistence following exposure to these antibiotics. Crucially, we find that persistence correlates positively to antibiotic resistance across strains. However, we find that different genes control resistance and persistence implying that they are independent traits. Specifically, we find that the number of type II toxin-antitoxin systems (TAs) in the genome of a strain is correlated to persistence, but not resistance. Our study shows that persistence and antibiotic resistance are complementary, but independent, evolutionary adaptations to stress and it highlights the key role played by TAs in the evolution of persistence.

  13. Degassing Processes at Persistently Active Explosive Volcanoes

    NASA Astrophysics Data System (ADS)

    Smekens, Jean-Francois

    Among volcanic gases, sulfur dioxide (SO2) is by far the most commonly measured. More than a monitoring proxy for volcanic degassing, SO 2 has the potential to alter climate patterns. Persistently active explosive volcanoes are characterized by short explosive bursts, which often occur at periodic intervals numerous times per day, spanning years to decades. SO 2 emissions at those volcanoes are poorly constrained, in large part because the current satellite monitoring techniques are unable to detect or quantify plumes of low concentration in the troposphere. Eruption plumes also often show high concentrations of ash and/or aerosols, which further inhibit the detection methods. In this work I focus on quantifying volcanic gas emissions at persistently active explosive volcanoes and their variations over short timescales (minutes to hours), in order to document their contribution to natural SO2 flux as well as investigate the physical processes that control their behavior. In order to make these measurements, I first develop and assemble a UV ground-based instrument, and validate it against an independently measured source of SO2 at a coal-burning power plant in Arizona. I establish a measurement protocol and demonstrate that the instrument measures SO 2 fluxes with < 20 % error. Using the same protocol, I establish a record of the degassing patterns at Semeru volcano (Indonesia), a volcano that has been producing cycles of repeated explosions with periods of minutes to hours for the past several decades. Semeru produces an average of 21-71 tons of SO2 per day, amounting to a yearly output of 8-26 Mt. Using the Semeru data, along with a 1-D transient numerical model of magma ascent, I test the validity of a model in which a viscous plug at the top of the conduit produces cycles of eruption and gas release. I find that it can be a valid hypothesis to explain the observed patterns of degassing at Semeru. Periodic behavior in such a system occurs for a very narrow range

  14. Radiofrequency Ablation of Persistent Atrial Fibrillation

    PubMed Central

    Hussein, Ayman A.; Saliba, Walid I.; Barakat, Amr; Bassiouny, Mohammed; Chamsi-Pasha, Mohammed; Al-Bawardy, Rasha; Hakim, Ali; Tarakji, Khaldoun; Baranowski, Bryan; Cantillon, Daniel; Dresing, Thomas; Tchou, Patrick; Martin, David O.; Varma, Niraj; Bhargava, Mandeep; Callahan, Thomas; Niebauer, Mark; Kanj, Mohamed; Chung, Mina; Natale, Andrea; Lindsay, Bruce D.; Wazni, Oussama M.

    2017-01-01

    Background Various ablation strategies of persistent atrial fibrillation (PersAF) have had disappointing outcomes, despite concerted clinical and research efforts, which could reflect progressive atrial fibrillation–related atrial remodeling. Methods and Results Two-year outcomes were assessed in 1241 consecutive patients undergoing first-time ablation of PersAF (2005–2012). The time intervals between the first diagnosis of PersAF and the ablation procedures were determined. Patients had echocardiograms and measures of B-type natriuretic peptide and C-reactive protein before the procedures. The median diagnosis-to-ablation time was 3 years (25th–75th percentiles 1–6.5). With longer diagnosis-to-ablation time (based on quartiles), there was a significant increase in recurrence rates in addition to an increase in B-type natriuretic peptide levels (P=0.01), C-reactive protein levels (P<0.0001), and left atrial size (P=0.03). The arrhythmia recurrence rates over 2 years were 33.6%, 52.6%, 57.1%, and 54.6% in the first, second, third, and fourth quartiles, respectively (Pcategorical<0.0001). In Cox Proportional Hazard analyses, B-type natriuretic peptide levels, C-reactive protein levels, and left atrial size were associated with arrhythmia recurrence. The diagnosis-to-ablation time had the strongest association with the ablation outcomes which persisted in multivariable Cox analyzes (hazard ratio for recurrence per +1Log diagnosis-to-ablation time 1.27, 95% confidence interval 1.14–1.43; P<0.0001; hazard ratio fourth versus first quartile 2.44, 95% confidence interval 1.68–3.65; Pcategorical<0.0001). Conclusions In patients with PersAF undergoing ablation, the time interval between the first diagnosis of PersAF and the catheter ablation procedure had a strong association with the ablation outcomes, such as shorter diagnosis-to-ablation times were associated with better outcomes and in direct association with markers of atrial remodeling. PMID:26763227

  15. China's water pollution by persistent organic pollutants.

    PubMed

    Bao, Lian-Jun; Maruya, Keith A; Snyder, Shane A; Zeng, Eddy Y

    2012-04-01

    Available data were reviewed to assess the status of contamination by persistent organic pollutants (POPs), including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), in drinking water sources and coastal waters of China. The levels of POPs in China's waters were generally at the high end of the global range. A comparison of China's regulatory limits indicated that PCBs in rivers and coastal water may pose potential human health risk. Occurrence of DDTs in some rivers of China may also pose health risk to humans using the regulatory limits of DDTs recommended by the European Union. Future monitoring of POPs in China's waters should be directed towards analytes of concern (e.g. PCBs and PCDD/Fs) and to fill data gaps for analytes (e.g. PBDEs, PCDD/Fs, and chlordane) and in watersheds/regions (e.g. West China) where data are scarce.

  16. Persistency in monthly mean temperatures in Europe

    NASA Astrophysics Data System (ADS)

    Rasol, Dubravka; Ólafsson, Haraldur

    2016-04-01

    Time series from a number of weather stations in Europe have been studied in order to assess the persistency of montly mean temperatures. In most regions, the correlation between the mean temperatures of two months next to each other in time has maxima in the summer and in the winter, while there are minima in the sping and the autumn. An exception from this is in the oceanic warm climate in the southwest, where the spring minimum is missing. A plausible explanation for the positive correlation in the winter may be related to snow on the ground. The snow is associated with cold spells and increases the albedo, contributing to extension of the low temperatures. The summertime correlation may be related to the water content of the soil. A cold and rainy period results in wet soil and subsequently, relatively large part of the energy of the incoming solar radiation is consumed by evaporation, rather than sensible heating. In the spring, there is generally no snow on the ground and in the autumn, the air temperature is not as sensitive to the water content of the soil as in the summer. This may explain the low correlation in spring and autumn.

  17. Laparoscopic management of persistent mullerian duct syndrome.

    PubMed

    Parelkar, Sandesh V; Gupta, Rahul Kumar; Oak, Sanjay; Sanghvi, Beejal; Kaltari, Deepak; Patil, Raj Shekhar; Prakash, Advait; Shimoga, Pradeep

    2009-09-01

    Persistent mullerian duct syndrome (PMDS), characterized by the presence of mullerian structures in a virilized male, frequently presents as undescended testis, either intraabdominal or within a hernial sac. We describe a 10-month-old infant with PMDS successfully managed by the laparoscopic approach. At the age of 1.5 months, the patient presented with a left inguinal hernia and bilateral nonpalpable gonads in another center and underwent left inguinal exploration. The uterus and a gonadlike structure along with the hernia sac were found in the inguinal canal. Left inguinal herniotomy was performed after reduction of the uterus and gonadlike structure. No gonadal biopsy was obtained. The patient was further investigated in the same center. His karyotype was 46,XY. Magnetic resonance imaging of the abdomen and pelvis revealed a uterinelike structure posterior to the urinary bladder, but neither testis nor ovaries were visualized. At 10 months of age, he was referred to our department for further management. A laparoscopic single-stage orchiopexy was performed. Both testes were identified and brought to the scrotum by splitting the uterus in the midline and then bringing the testes with the vas and attached uterine tissue into the scrotum. The aim of placement of well-vascularized testes in the scrotum was achieved as confirmed on follow-up color Doppler ultrasound study 6 months postoperatively, which showed normal vascularity. Laparoscopic surgical techniques for this condition are also discussed.

  18. On the persistence of adiabatic shear bands

    NASA Astrophysics Data System (ADS)

    Boakye-Yiadom, S.; Bassim, M. N.; Al-Ameeri, S.

    2012-08-01

    It is generally agreed that the initiation and development of adiabatic shear bands (ASBs) are manifestations of damage in metallic materials subjected to high strain rates and large strains as those due to impact in a Hopkinson Bar system. Models for evolution of these bands have been described in the literature. One question that has not received attention is how persistent these bands are and whether their presence and effect can be reversed or eliminated by using a process of thermal (heat treatment) or thermo-mechanical treatment that would relieve the material from the high strain associated with ASBs and their role as precursors to crack initiation and subsequent failure. Since ASBs are more prevalent and more defined in BCC metals including steels, a study was conducted to investigate the best conditions of generating ASBs in a heat treatable steel, followed by determining the best conditions for heat treatment of specimens already damaged by the presence of ASBs in order to relieve the strains due to ASBs and restore the material to an apparent microstructure without the "scars" due to the previous presence of ASBs. It was found that heat treatment achieves the curing from ASBs. This presentation documents the process undertaken to achieve this objective.

  19. Selected persistent organochlorine pollutants in Romania.

    PubMed

    Covaci, A; Hura, C; Schepens, P

    2001-12-03

    Selected persistent organochlorine pollutants, including PCBs, DDT and its metabolites (DDTs) and hexachlorocyclohexane isomers (HCHs) were determined in soil, animal fat and human serum samples from Romania. All methods were rigorously tested and adequate quality control was ensured. Soil samples from lassy County showed a lower contamination with organochlorines than samples from other Romanian regions. While DDTs concentrations in soil were significantly higher at rural sites, only few samples (three out of 47) exceeded the official Romanian norms for DDTs. PCBs concentrations were low in rural sites (< 8 ng/g soil), but rather high (up to 134 ng/g soil) in urban soils collected mostly from parks (Bucharest, Arad, Baia Mare, Pitesti and Ploicsti). Animal fat samples from lassy showed high concentrations of organochlorine pesticides (HCHs concentrations up to 12370 ng/g fat), but similar PCB concentrations when compared with Arad samples. Two samples (from 24) exceeded the EU norms (1000 ng/g fat) for HCHs and DDTs in animal fat. Organochlorines were found in higher concentrations in some samples of human serum from Timisoara due to a broader age range. Samples of human serum from lassy mothers showed higher HCHs and DDTs concentrations than samples from a similar group from Antwerp, Belgium. HCB and PCBs were higher in Antwerp cohort. Romanian samples showed a higher ratio DDT/sigmaDDTs, but similar ratios PCB 153/sigmaPCBs.

  20. Masking, persistence, and transfer in rotating arcs.

    PubMed

    Geremek, Adam; Stürzel, Frank; da Pos, Osvaldo; Spillmann, Lothar

    2002-10-01

    We demonstrate that the apparent length of a thin white arc on a black disk, rotating concentrically at 2.5 rps, varies with angular length and exposure duration. While short arcs (9-18 degrees ) gradually expand, long arcs (36-72 degrees ) first undergo a brief contraction, before they also expand. On average, perceived elongation asymptotes after 15 s equivalent to visual persistencies ranging from 68 to 170 ms. Using bi- and tri-colored arcs, we find that the apparent increase in length derives from the rear end of the rotating stimulus, while the initial shrinkage derives from contraction of the middle. After 15 s of adaptation, perceived length of the arc decays to actual stimulus length within an average of 6 s and, upon re-exposure of the arc, reaches its former value after only 5 s (priming). When the rotating arc is presented first to one eye and then to the other, apparent elongation transfers partially (46%), suggesting a contribution by the binocular cells in the visual cortex. A partial transfer (26%) also occurs from clockwise to counterclockwise rotation. When tested interocularly, the directional transfer is more pronounced (47%) and equals the interocular transfer under equidirectional conditions, suggesting that the directional transfer (cw versus ccw) might derive from non-directional cortical units. Whereas the initial contraction may be attributable to backward masking, the observed elongation likely reflects a cumulative build-up of after-discharge in cortical neurons over time.

  1. Persistent ion pairing in aqueous hydrochloric acid.

    PubMed

    Baer, Marcel D; Fulton, John L; Balasubramanian, Mahalingam; Schenter, Gregory K; Mundy, Christopher J

    2014-07-03

    For strong acids, like hydrochloric acid, the complete dissociation into an excess proton and conjugated base as well as the formation of independent solvated charged fragments is assumed. The existence of chloride-hydronium (Cl(-)···H3O(+)) contact ion pairs even in moderate concentration hydrochloric acid (2.5 m) demonstrates that the counterions do not behave merely as spectators. Through comparison of recent extended X-ray absorption fine structure (EXAFS) measurements to state-of-the-art density functional theory (DFT) simulations, we are able to obtain a unique view into the molecular structure of medium-to-high concentrated electrolytes. Here we report that the Cl(-)···H3O(+) contact ion pair structure persists throughout the entire concentration range studied and that these structures differ significantly from moieties studied in microsolvated hydrochloric acid gas phase clusters. Characterizing distinct populations of these ion pairs gives rise to a novel molecular level description of how to view the reaction network for acid dissociation and how it relates to our picture of acid-base equilibria.

  2. Persistence of explosives under real world conditions

    NASA Astrophysics Data System (ADS)

    Papantonakis, Michael R.; Furstenberg, Robert; Nguyen, Viet; Fischer, Thomas; Howard, Andrew; Adams, Katy; Kendziora, Christopher A.; McGill, R. Andrew

    2016-05-01

    Those that handle explosives materials invariably become contaminated with particulates of materials, which become entrapped in the grooves of the fingers and are then transferred by contact to other surfaces. These particles provide an evidentiary trail which is useful for security applications, a fact which is enhanced by the fact that many explosives materials of interest have low vapor pressures, augmenting their longevity. The persistence or stability of explosives particles on a substrate is a function of several environmental parameters or particle properties, including vapor pressure, particle size and geometry, airflow, particle field size, substrate topography, humidity, reactivity, adlayers, admixtures, particle areal density, and temperature. In this work we deposited particles of 2,4-dinitrotoluene on standard microscope glass slides by particle sieving and studied their sublimation as a function of temperature and relative humidity. A custom airflow cell allowed us to monitor the particles with in situ photomicroscopy while keeping the airflow over the particles, substrate type, and areal field size constant for each experiment. We define the size-independent radial sublimation velocity for the equivalent sphere of a particle as the parameter to characterize the sublimation rate. The dependence of the sublimation rate for an ensemble of particles on temperature was quantified according the radial sublimation velocity, while the sublimation of 2,4-dinintrotoluene was found to independent of relative humidity between 25-90%.

  3. The onset of lactase persistence in Europe.

    PubMed

    Gerbault, Pascale

    2013-01-01

    The genomic region containing the lactase (LCT) gene shows one of the strongest signals of positive selection in Europeans, detectable using a range of approaches including haplotype length, linked microsatellite variation and population-differentiation-based tests. Lactase is the enzyme that carries out the digestion of the milk sugar lactose. Its expression decreases at some point after the weaning period is over in most mammals and in around 68% of all living adult humans. However, in some humans, particularly those from populations with a history of dairying, lactase is expressed throughout adulthood. This trait is called lactase persistence (LP), and in people of European ancestry, it is associated with a single mutation (-13910*T). Evidence from the detection of dairy fat residues in potsherds, and allele frequencies in ancient DNA samples suggest that LP arose after dairying practices had developed. However, the reasons why LP may have been advantageous are still debated, and the respective contribution of demography and natural selection remains to be disentangled. This paper discusses various studies, from archaeology to population genetics, that have shed some light on the subject by investigating the evolution of LP in Europe.

  4. Endangered plants persist under phosphorus limitation.

    PubMed

    Wassen, Martin J; Venterink, Harry Olde; Lapshina, Elena D; Tanneberger, Franziska

    2005-09-22

    Nitrogen enrichment is widely thought to be responsible for the loss of plant species from temperate terrestrial ecosystems. This view is based on field surveys and controlled experiments showing that species richness correlates negatively with high productivity and nitrogen enrichment. However, as the type of nutrient limitation has never been examined on a large geographical scale the causality of these relationships is uncertain. We investigated species richness in herbaceous terrestrial ecosystems, sampled along a transect through temperate Eurasia that represented a gradient of declining levels of atmospheric nitrogen deposition--from approximately 50 kg ha(-1) yr(-1) in western Europe to natural background values of less than 5 kg ha(-1) yr(-1) in Siberia. Here we show that many more endangered plant species persist under phosphorus-limited than under nitrogen-limited conditions, and we conclude that enhanced phosphorus is more likely to be the cause of species loss than nitrogen enrichment. Our results highlight the need for a better understanding of the mechanisms of phosphorus enrichment, and for a stronger focus on conservation management to reduce phosphorus availability.

  5. Persistent Ion Pairing in Aqueous Hydrochloric Acid

    SciTech Connect

    Baer, Marcel D.; Fulton, John L.; Balasubramanian, Mahalingam; Schenter, Gregory K.; Mundy, Christopher J.

    2014-07-03

    For strong acids, like hydrochloric acid, the complete dissociation into an excess proton and conjugated base as well as the formation of independent solvated charged fragments is assumed. The existence of a chloride-Hyronium (Cl-H3O+) contact ion pairs even in moderate concentration hydrochloric acid (2.5 m) demonstrates that the counter ions do not behave merely as spectators. Through the use of modern extended X-ray absorption fine structure (EXAFS) measurements in conjunction with state-of-the-art density functional theory (DFT) simulations, we are able to obtain an unprecedented view into the molecular structure of medium to high concentrated electrolytes. Here we report that the Cl-H3O+ contact ion pair structure persists throughout the entire concentration range studied and that these structures differ significantly from moieties studied in micro-solvated hydrochloric acid clusters. Characterizing distinct populations of these ion pairs gives rise to a novel molecular level description of how to think about the activity of the proton that impacts our picture of the pH scale. Funding for CJM, GKS, and JLF was provided by DOE Office of Science, Office of Basic Energy Science, Division of Chemical Sciences, Geosciences, and Biosciences. Funding for MDB was provided throught the Laboratory Directed Research and Development program at Pacific Northwest National Laboratory. MB was funded through Argonne National Laboratory.

  6. Earliest Archaeological Evidence of Persistent Hominin Carnivory

    PubMed Central

    Ferraro, Joseph V.; Plummer, Thomas W.; Pobiner, Briana L.; Oliver, James S.; Bishop, Laura C.; Braun, David R.; Ditchfield, Peter W.; Seaman, John W.; Binetti, Katie M.; Seaman, John W.; Hertel, Fritz; Potts, Richard

    2013-01-01

    The emergence of lithic technology by ∼2.6 million years ago (Ma) is often interpreted as a correlate of increasingly recurrent hominin acquisition and consumption of animal remains. Associated faunal evidence, however, is poorly preserved prior to ∼1.8 Ma, limiting our understanding of early archaeological (Oldowan) hominin carnivory. Here, we detail three large well-preserved zooarchaeological assemblages from Kanjera South, Kenya. The assemblages date to ∼2.0 Ma, pre-dating all previously published archaeofaunas of appreciable size. At Kanjera, there is clear evidence that Oldowan hominins acquired and processed numerous, relatively complete, small ungulate carcasses. Moreover, they had at least occasional access to the fleshed remains of larger, wildebeest-sized animals. The overall record of hominin activities is consistent through the stratified sequence – spanning hundreds to thousands of years – and provides the earliest archaeological evidence of sustained hominin involvement with fleshed animal remains (i.e., persistent carnivory), a foraging adaptation central to many models of hominin evolution. PMID:23637995

  7. Persistent neural activity in head direction cells

    NASA Technical Reports Server (NTRS)

    Taube, Jeffrey S.; Bassett, Joshua P.; Oman, C. M. (Principal Investigator)

    2003-01-01

    Many neurons throughout the rat limbic system discharge in relation to the animal's directional heading with respect to its environment. These so-called head direction (HD) cells exhibit characteristics of persistent neural activity. This article summarizes where HD cells are found, their major properties, and some of the important experiments that have been conducted to elucidate how this signal is generated. The number of HD and angular head velocity cells was estimated for several brain areas involved in the generation of the HD signal, including the postsubiculum, anterior dorsal thalamus, lateral mammillary nuclei and dorsal tegmental nucleus. The HD cell signal has many features in common with what is known about how neural integration is accomplished in the oculomotor system. The nature of the HD cell signal makes it an attractive candidate for using neural network models to elucidate the signal's underlying mechanisms. The conditions that any network model must satisfy in order to accurately represent how the nervous system generates this signal are highlighted and areas where key information is missing are discussed.

  8. Dichlorodiphenyltrichloroethane (DDT): ubiquity, persistence, and risks.

    PubMed Central

    Turusov, Vladimir; Rakitsky, Valery; Tomatis, Lorenzo

    2002-01-01

    Due to uncontrolled use for several decades, dichlorodiphenyltrichloroethane (DDT), probably the best known and most useful insecticide in the world, has damaged wildlife and might have negative effects on human health. This review gives a brief history of the use of DDT in various countries and presents the results of epidemiologic and experimental studies of carcinogenesis. Even though its use has been prohibited in most countries for ecologic considerations, mainly because of its negative impact on wildlife, it is still used in some developing countries for essential public health purposes, and it is still produced for export in at least three countries. Due to its stability and its capacity to accumulate in adipose tissue, it is found in human tissues, and there is now not a single living organism on the planet that does not contain DDT. The possible contribution of DDT to increasing the risks for cancers at various sites and its possible role as an endocrine disruptor deserve further investigation. Although there is convincing experimental evidence for the carcinogenicity of DDT and of its main metabolites DDE and DDD, epidemiologic studies have provided contrasting or inconclusive, although prevailingly negative, results. The presence and persistence of DDT and its metabolites worldwide are still problems of great relevance to public health. Efficient pesticides that do not have the negative properties of DDT, together with the development of alternative methods to fight malaria, should be sought with the goal of completely banning DDT. PMID:11836138

  9. Blunt pancreatic trauma: A persistent diagnostic conundrum?

    PubMed Central

    Kumar, Atin; Panda, Ananya; Gamanagatti, Shivanand

    2016-01-01

    Blunt pancreatic trauma is an uncommon injury but has high morbidity and mortality. In modern era of trauma care, pancreatic trauma remains a persistent challenge to radiologists and surgeons alike. Early detection of pancreatic trauma is essential to prevent subsequent complications. However early pancreatic injury is often subtle on computed tomography (CT) and can be missed unless specifically looked for. Signs of pancreatic injury on CT include laceration, transection, bulky pancreas, heterogeneous enhancement, peripancreatic fluid and signs of pancreatitis. Pan-creatic ductal injury is a vital decision-making parameter as ductal injury is an indication for laparotomy. While lacerations involving more than half of pancreatic parenchyma are suggestive of ductal injury on CT, ductal injuries can be directly assessed on magnetic resonance imaging (MRI) or encoscopic retrograde cholangio-pancreatography. Pancreatic trauma also shows temporal evolution with increase in extent of injury with time. Hence early CT scans may underestimate the extent of injures and sequential imaging with CT or MRI is important in pancreatic trauma. Sequential imaging is also needed for successful non-operative management of pancreatic injury. Accurate early detection on initial CT and adopting a multimodality and sequential imaging strategy can improve outcome in pancreatic trauma. PMID:26981225

  10. Long-term persistence of solar activity

    NASA Technical Reports Server (NTRS)

    Ruzmaikin, Alexander; Feynman, Joan; Robinson, Paul

    1994-01-01

    We examine the question of whether or not the non-periodic variations in solar activity are caused by a white-noise, random process. The Hurst exponent, which characterizes the persistence of a time series, is evaluated for the series of C-14 data for the time interval from about 6000 BC to 1950 AD. We find a constant Hurst exponent, suggesting that solar activity in the frequency range from 100 to 3000 years includes an important continuum component in addition to the well-known periodic variations. The value we calculate, H approximately 0.8, is significantly larger than the value of 0.5 that would correspond to variations produced by a white-noise process. This value is in good agreement with the results for the monthly sunspot data reported elsewhere, indicating that the physics that produces the continuum is a correlated random process and that it is the same type of process over a wide range of time interval lengths.

  11. PERSISTENT PUPILLARY MEMBRANE OR ACCESSORY IRIS MEMBRANE?.

    PubMed

    Gavriş, Monica; Horge, Ioan; Avram, Elena; Belicioiu, Roxana; Olteanu, Ioana Alexandra; Kedves, Hanga

    2015-01-01

    Frequently, in literature and curent practice, accessory iris membrane (AIM) and persistant pupillary membrane (PPM) are confused. Both AIM and PPM are congenital iris anomalies in which fine or thick iris strands arrise form the collarette and obscure the pupil. AIM, which is also called iris duplication, closely resembles the normal iris tissue in color and thickness and presents a virtual second pseudopupil aperture in the centre while PPM even in its extreme forms presents as a translucent or opaque membranous structure that extends across the pupil and has no pseudopupil. Mydriatiscs, laser treatment or surgery is used to clear the visual axis and optimize visual development. Surgical intervention is reserved for large, dense AIMs and PPMs. Our patient, a 29 year old male, has come with bilateral dense AIM, bilateral compound hyperopic astigmatism, BCVA OD = 0.6, BCVA OS = 0.4, IOP OU = 17 mmHg. To improve the visual acuity of the patient we decided to do a bilateral membranectomy, restoring in this way transparency of the visual axis. After surgery, the visual acuity improved to BCVA OD= 0.8, BCVA OS=0.8.

  12. Persistent Pulmonary Hypertension of the Newborn

    PubMed Central

    Lakshminrusimha, Satyan; Keszler, Martin

    2015-01-01

    Persistent pulmonary hypertension of the newborn (PPHN) is often secondary to parenchymal lung disease (such as meconium aspiration syndrome) or lung hypoplasia (with congenital diaphragmatic hernia) but can also be idiopathic. PPHN is characterized by elevated pulmonary vascular resistance, resulting in right-to-left shunting of blood and hypoxemia. The diagnosis of PPHN is based on clinical evidence of labile hypoxemia often associated with differential cyanosis and confirmed by echocardiography. Lung volume recruitment with optimal use of positive end-expiratory pressure or mean airway pressure and/or surfactant is very important in secondary PPHN due to parenchymal lung disease. Other management strategies include optimal oxygenation, avoiding respiratory and metabolic acidosis, blood pressure stabilization, sedation, and pulmonary vasodilator therapy. Failure of these measures leads to consideration of extracorporeal membrane oxygenation, although this rescue therapy is needed less frequently with advances in medical management. Randomized clinical trials with long-term follow-up are required to evaluate various therapeutic strategies in PPHN. PMID:26783388

  13. Persistent pulmonary hypertension of the newborn.

    PubMed

    Sharma, Vinay; Berkelhamer, Sara; Lakshminrusimha, Satyan

    2015-01-01

    Persistent pulmonary hypertension of the newborn (PPHN) is characterized by elevated pulmonary vascular resistance resulting in right-to-left shunting of blood and hypoxemia. PPHN is often secondary to parenchymal lung disease (such as meconium aspiration syndrome, pneumonia or respiratory distress syndrome) or lung hypoplasia (with congenital diaphragmatic hernia or oligohydramnios) but can also be idiopathic. The diagnosis of PPHN is based on clinical evidence of labile hypoxemia often associated with differential cyanosis. The diagnosis is confirmed by the echocardiographic demonstration of - (a) right-to-left or bidirectional shunt at the ductus or foramen ovale and/or, (b) flattening or leftward deviation of the interventricular septum and/or, (c) tricuspid regurgitation, and finally (d) absence of structural heart disease. Management strategies include optimal oxygenation, avoiding respiratory and metabolic acidosis, blood pressure stabilization, sedation and pulmonary vasodilator therapy. Failure of these measures would lead to consideration of extracorporeal membrane oxygenation (ECMO); however decreased need for this rescue therapy has been documented with advances in medical management. While trends also note improved survival, long-term neurodevelopmental disabilities such as deafness and learning disabilities remain a concern in many infants with severe PPHN. Funded by: 1R01HD072929-0 (SL).

  14. Making web annotations persistent over time

    SciTech Connect

    Sanderson, Robert; Van De Sompel, Herbert

    2010-01-01

    As Digital Libraries (DL) become more aligned with the web architecture, their functional components need to be fundamentally rethought in terms of URIs and HTTP. Annotation, a core scholarly activity enabled by many DL solutions, exhibits a clearly unacceptable characteristic when existing models are applied to the web: due to the representations of web resources changing over time, an annotation made about a web resource today may no longer be relevant to the representation that is served from that same resource tomorrow. We assume the existence of archived versions of resources, and combine the temporal features of the emerging Open Annotation data model with the capability offered by the Memento framework that allows seamless navigation from the URI of a resource to archived versions of that resource, and arrive at a solution that provides guarantees regarding the persistence of web annotations over time. More specifically, we provide theoretical solutions and proof-of-concept experimental evaluations for two problems: reconstructing an existing annotation so that the correct archived version is displayed for all resources involved in the annotation, and retrieving all annotations that involve a given archived version of a web resource.

  15. Persistence and metabolism of imidacloprid in rice.

    PubMed

    Akoijam, Romila; Singh, Balwinder

    2014-05-01

    Imidacloprid is a systemic insecticide which gives effective control of plant and leaf hoppers in rice. The persistence and metabolism of imidacloprid in paddy leaves, rice grains, bran, straw and husk were studied following two applications of imidacloprid (Confidor 17.8 SL) @ 20 and 80 g a.i. ha(-1) at an interval of 10 days. Samples of paddy leaves were collected at various time intervals. The samples of rice grains, bran, straw and husk were collected at the time of harvest. The limit of quantification of imidacloprid and its metabolites was worked out to be 0.01 mg kg(-1). The maximum residues of imidacloprid and its metabolites in paddy leaves after 0 day (1 h after last spray) of its application @ 20 and 80 g a.i. ha(-1) were found to be 4.57 and 13.94 mg kg(-1), respectively. These residues could not be detected after 60 and 90 days following last application of imidacloprid at lower and higher dosages, respectively. In rice, olefin metabolite was found to be the main constituent, followed by nitroguanidine, urea, 5-hydroxy, chloronicotinic acid and nitrosimine. The samples of rice grains, bran, straw and husk did not reveal the presence of imidacloprid or its metabolites following its application at both the dosages at harvest.

  16. Persistence of social signatures in human communication.

    PubMed

    Saramäki, Jari; Leicht, E A; López, Eduardo; Roberts, Sam G B; Reed-Tsochas, Felix; Dunbar, Robin I M

    2014-01-21

    The social network maintained by a focal individual, or ego, is intrinsically dynamic and typically exhibits some turnover in membership over time as personal circumstances change. However, the consequences of such changes on the distribution of an ego's network ties are not well understood. Here we use a unique 18-mo dataset that combines mobile phone calls and survey data to track changes in the ego networks and communication patterns of students making the transition from school to university or work. Our analysis reveals that individuals display a distinctive and robust social signature, captured by how interactions are distributed across different alters. Notably, for a given ego, these social signatures tend to persist over time, despite considerable turnover in the identity of alters in the ego network. Thus, as new network members are added, some old network members either are replaced or receive fewer calls, preserving the overall distribution of calls across network members. This is likely to reflect the consequences of finite resources such as the time available for communication, the cognitive and emotional effort required to sustain close relationships, and the ability to make emotional investments.

  17. [Endogenous persistent hypoglicemia of adult: case report].

    PubMed

    Costa, Raquel R; Maia, Frederico F R; Araújo, Levimar R

    2007-02-01

    Persistent Hyperinsulinemic Endogenous hypoglycemia in adults is, in most cases, due to Insulinoma. Nesidioblastosis, a peculiar functional hyperinsulinemia from hypertrophic beta cells, has been described mainly in newborns. This article describes a 34-year-old patient who presented hyperinsulinemic endogenous hypoglycemia clinical and laboratorial situation (Fasting glycemia: 54 mg/dl / Reference Interval (RI): 60-99 mg/dl; Serum insulin: 70.9 mcU/ml / RI: < 29.1 mcU/ml; e C peptide: 7.1 ng/ml / RI: 1.1-5.0 ng/ml). It was suspected Insulinoma. Because of the lack of typical images in radiologic exams (ultrasonography and computerized tomography) it had been decided to do laparotomy, but it was not found any macroscopic pancreatic tumor. Histological and histochemistry examination of a distal pancreatic segment showed alteration suitable to nesidioblastosis. The patient presented clinical stability during the next two months, however, after that, there was a recurrence of a hypoglycemia crisis, refractory to Octreotide administration. It was done "octreoscan", which showed expanded nesidioblastosis, being done extensive partial pancreatectomy. Octreotide was used again, with a good control of the hypoglycemia crisis. As it is an uncommon diagnosis in an adult, the objective of this article is to describe the diagnostic and therapeutic aspects in cases of hyperinsulinemic endogenous hypoglicemia.

  18. Persistence of social signatures in human communication

    PubMed Central

    Saramäki, Jari; Leicht, E. A.; López, Eduardo; Roberts, Sam G. B.; Reed-Tsochas, Felix; Dunbar, Robin I. M.

    2014-01-01

    The social network maintained by a focal individual, or ego, is intrinsically dynamic and typically exhibits some turnover in membership over time as personal circumstances change. However, the consequences of such changes on the distribution of an ego’s network ties are not well understood. Here we use a unique 18-mo dataset that combines mobile phone calls and survey data to track changes in the ego networks and communication patterns of students making the transition from school to university or work. Our analysis reveals that individuals display a distinctive and robust social signature, captured by how interactions are distributed across different alters. Notably, for a given ego, these social signatures tend to persist over time, despite considerable turnover in the identity of alters in the ego network. Thus, as new network members are added, some old network members either are replaced or receive fewer calls, preserving the overall distribution of calls across network members. This is likely to reflect the consequences of finite resources such as the time available for communication, the cognitive and emotional effort required to sustain close relationships, and the ability to make emotional investments. PMID:24395777

  19. Persistent telomere cohesion triggers a prolonged anaphase.

    PubMed

    Kim, Mi Kyung; Smith, Susan

    2014-01-01

    Telomeres use distinct mechanisms (not used by arms or centromeres) to mediate cohesion between sister chromatids. However, the motivation for a specialized mechanism at telomeres is not well understood. Here we show, using fluorescence in situ hybridization and live-cell imaging, that persistent sister chromatid cohesion at telomeres triggers a prolonged anaphase in normal human cells and cancer cells. Excess cohesion at telomeres can be induced by inhibition of tankyrase 1, a poly(ADP-ribose) polymerase that is required for resolution of telomere cohesion, or by overexpression of proteins required to establish telomere cohesion, the shelterin subunit TIN2 and the cohesin subunit SA1. Regardless of the method of induction, excess cohesion at telomeres in mitosis prevents a robust and efficient anaphase. SA1- or TIN2-induced excess cohesion and anaphase delay can be rescued by overexpression of tankyrase 1. Moreover, we show that primary fibroblasts, which accumulate excess telomere cohesion at mitosis naturally during replicative aging, undergo a similar delay in anaphase progression that can also be rescued by overexpression of tankyrase 1. Our study demonstrates that there are opposing forces that regulate telomere cohesion. The observation that cells respond to unresolved telomere cohesion by delaying (but not completely disrupting) anaphase progression suggests a mechanism for tolerating excess cohesion and maintaining telomere integrity. This attempt to deal with telomere damage may be ultimately futile for aging fibroblasts but useful for cancer cells.

  20. A Case Study of Second Year Student Persistence.

    ERIC Educational Resources Information Center

    Gohn, Lyle; Swartz, James; Donnelly, Sharon

    2001-01-01

    Eleven second-year college students, representing various characteristics of the student population, were interviewed on issues related to school persistence. Major factors relating to attrition or persistence for second-year students included: (1) adjustment to stress; (2) grade satisfaction; (3) time management; (4) financial management; and (5)…