38 research outputs found

    Aspects of habitat disturbance by Cape porcupines in a savanna ecosystem

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    Habitat disturbances by Cape porcupines (Hystrix africaeaustralis)in a savanna ecosystem were investigated at Nylsvley Nature Reserve by using transect line surveys for signs of porcupine foraging activities. The density of foraging diggings was significantly higher in Burkea savanna than in Acacia savanna. A significantly higher proportion of trees was debarked in Burkeaand rocky outcrop savanna than in Acacia savanna. The only two species which were preferentially debarked were dominant species in the former two habitat types. Significantly more trees had roots gnawed on by porcupines in Burkea savanna than elsewhere, and the species most affected (Burkea africana) was a dominant species in this habitat type. Concentrated feeding activities in Burkea and rocky outcrop savanna by porcupines may affect the structure of these plant communities

    Ventricular septal defect due to blunt chest trauma

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    Blunt chest trauma may cause cardiac trauma, this possibility often being overlooked. Various anatomical structures may be affected. A case of ventr'icular septal defect due to blunt chest trauma is described and the relevant literature is reviewed

    HPV-18 transformed cells fail to arrest in G1 in response to quercetin treatment

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    Previous work with primary human keratinocytes demonstrated that quercetin, a potent mutagen found in high levels in bracken fern (Pteridium aquilinum), arrested cells in G1 with concomitant elevation of the cyclin-dependent kinase inhibitor (cdki) p27Kip1. Expression of the human papillomavirus type 16 (HPV-16) E6 and E7 oncoproteins, under transcriptional control of a heterologous promoter, in transformed keratinocytes failed to abrogate this arrest [Beniston, R., Campo, M.S., 2003. Quercetin elevates p27(Kip1) and arrests both primary and HPV-16 E6/E7 transformed human keratinocytes in G1. Oncogene 22, 5504–5514]. Given the link between papillomavirus infection, bracken fern in the diet and cancer of the oesophagus in humans, we wished to investigate further whether cells transformed by the whole genome of HPV-16 or HPV-18, with E6 and E7 under the transcriptional control of their respective homologous promoters, would be similarly arrested in G1 by quercetin. In agreement with earlier work, quercetin arrested HPV-16 transformed cells in G1 with an increase in the cyclin-dependent kinase inhibitor p27Kip1. However, HPV-18 transformed cells did not arrest after quercetin treatment. The failure of HPV-18 transformed cells to arrest in G1 was linked to the up-regulation of the HPV-18 long control region (LCR) by quercetin, maintaining high expression of the viral transforming proteins. Transcriptional up-regulation of the HPV-18 LCR was mediated by a “quercetin responsive element” homologous to the one identified previously in the bovine papillomavirus type 4 (BPV-4) LCR

    Identification of canine papillomavirus type 1 (CPV1) DNA in dogs with cutaneous papillomatosis

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    Canine oral papillomavirus (COPV), also known as Canine Papillomavirus type 1 (CPV1), induces papillomas at the mucous membranes of the oral cavity and at the haired skin of dogs. The classification of Papillomavirus (PV) types is based on the L1 capsid protein and nucleotide sequence; so far, 14 CPV types have been described in several countries, but the molecular characterization of CPV in Brazil is lacking. This study investigated the presence of the PV in seven papillomas from four mixed breed dogs from Londrina/PR, Southern Brazil, by partial sequencing of the L1 gene. Seven exophytic cutaneous lesions were surgically removed and processed for histopathological and molecular characterization. Histopathology confirmed the lesions as viral papillomas due to typical histological features. Polymerase Chain Reaction (PCR) assay using the FAP59 and FAP64 primers targeted the L1 gene followed by sequence analysis of the amplicons identified CPV1 in all evaluated papilloma samples. This study represents the first description of CPV1 DNA associated with canine papillomatosis in Brazil

    The parent?infant dyad and the construction of the subjective self

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    Developmental psychology and psychopathology has in the past been more concerned with the quality of self-representation than with the development of the subjective agency which underpins our experience of feeling, thought and action, a key function of mentalisation. This review begins by contrasting a Cartesian view of pre-wired introspective subjectivity with a constructionist model based on the assumption of an innate contingency detector which orients the infant towards aspects of the social world that react congruently and in a specifically cued informative manner that expresses and facilitates the assimilation of cultural knowledge. Research on the neural mechanisms associated with mentalisation and social influences on its development are reviewed. It is suggested that the infant focuses on the attachment figure as a source of reliable information about the world. The construction of the sense of a subjective self is then an aspect of acquiring knowledge about the world through the caregiver's pedagogical communicative displays which in this context focuses on the child's thoughts and feelings. We argue that a number of possible mechanisms, including complementary activation of attachment and mentalisation, the disruptive effect of maltreatment on parent-child communication, the biobehavioural overlap of cues for learning and cues for attachment, may have a role in ensuring that the quality of relationship with the caregiver influences the development of the child's experience of thoughts and feelings

    Palaeoenvironments during a terminal Oligocene or early Miocene transgression in a fluvial system at the southwestern tip of Africa

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    The SARAO MeerKAT 1.3 GHz Galactic Plane Survey

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    We present the SARAO MeerKAT Galactic Plane Survey (SMGPS), a 1.3 GHz continuum survey of almost half of the Galactic Plane (251○ ≀l ≀ 358○ and 2○ ≀l ≀ 61○ at |b| ≀ 1 5). SMGPS is the largest, most sensitive and highest angular resolution 1 GHz survey of the Plane yet carried out, with an angular resolution of 8″ and a broadband RMS sensitivity of ∌10–20 ÎŒJy beam−1. Here we describe the first publicly available data release from SMGPS which comprises data cubes of frequency-resolved images over 908–1656 MHz, power law fits to the images, and broadband zeroth moment integrated intensity images. A thorough assessment of the data quality and guidance for future usage of the data products are given. Finally, we discuss the tremendous potential of SMGPS by showcasing highlights of the Galactic and extragalactic science that it permits. These highlights include the discovery of a new population of non-thermal radio filaments; identification of new candidate supernova remnants, pulsar wind nebulae and planetary nebulae; improved radio/mid-IR classification of rare Luminous Blue Variables and discovery of associated extended radio nebulae; new radio stars identified by Bayesian cross-matching techniques; the realisation that many of the largest radio-quiet WISE H II region candidates are not true H II regions; and a large sample of previously undiscovered background H I galaxies in the Zone of Avoidance

    First record of a vagrant Commerson’s dolphin, Cephalorhynchus commersonii, at the southern African continental shelf

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    Commerson’s Dolphins Cephalorhynchus commersonii are distributed in two disjunct populations, one around southern South America and the other around the sub-Antarctic Kerguelen Islands. These populations have been shown to be morphologically and genetically distinct and movement between the two populations is unlikely. We report on the sighting of a single specimen over the South African continental shelf on 13 November 2004. To our knowledge this is the first record of this species in South African waters and such a vast distance (over 4000 km) from the known distribution limits.Keywords: Cephalorhynchus commersonii, vagrant, distribution, South Afric

    Disease outbreaks among penguins at sub-Antarctic Marion Island: a conservation concern

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    In 1992 and 1993, unknown diseases killed 250–300 King Penguins Aptenodytes patagonicus and an estimated 5–10 thousand Macaroni Penguins Eudyptes chrysolophus at sub-Antarctic Marion Island. At the same island, an outbreak of avian cholera Pasteurella multocida during November 2004 killed approximately 2000 Macaroni Penguins at Kildalkey Bay. Other breeding colonies of Macaroni Penguins and other species of seabirds at the island were not affected at the time. Procedures for reporting and dealing with such outbreaks are now being developed.Centre of Excellence for Invasion Biolog
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