18 resultados para Landmark
Resumo:
In previous experiments suggesting that previewing visual landscapes speeds homing from familiar release sites, restricted access to olfactory cues may have artefactually encouraged homing pigeons, Calumba livia, to resort to visual landmark orientation. Since evidence for the role of visual landmarks in wide-ranging avian orientation is still equivocal, Braithwaite & Guilford's (1991, Proc. R. Sec. Lond. Ser. B, 245, 183-186) 'previewing' experiments were replicated: birds were allowed or denied visual access to a familiar site prior to release, but allowed ample access to olfactory cues. In experiment 1, allowing birds to preview familiar sites for 5 min prior to release enhanced homing speeds by about 12%. In experiment 2, modified to reduce between-day effects on variation, previewing enhanced homing speeds by about 16%. These experiments support the conclusion that visual landmarks remote from sight of the loft are an important component of the familiar area map, although the nature of the landmarks and how they are encoded remain to be determined. (C) 1997 The Association for the Study of Animal Behaviour.
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This book explores the development of basic principles of property law in leading cases. Each paper considers a case on land, personal property or intangibles, discussing what that case contributes to the dominant themes of property jurisprudence - how are property rights acquired? What is the content of property rights? What are the limits or boundaries of property? How are property rights extinguished? Individually and collectively, the papers identify a number of important themes for the doctrinal development of property institutions and their broader justification. These themes include: the obscure and incremental development of seemingly foundational principles, the role of instrumentalism in property reasoning, the influence of the law of tort on the scope of property doctrines, and the impact of Roman legal reasoning on the common law of property. One or more of these themes (and others) is revealed through careful case analysis in each paper and they are collected and critically explored in the editors' introduction. This makes for a coherent and provocative collection.
Resumo:
Platyhelminthes occupy a unique position in nerve-muscle evolution, being the most primitive of metazoan phyla. Essentially, their nervous system consists of an archaic brain and associated pairs of longitudinal nerve cords cross-linked as an orthogon by transverse commissures. Confocal imaging reveals that these central nervous system elements are in continuity with an array of peripheral nerve plexuses which innervate a well-differentiated grid work of somatic muscle as well as a complexity of myofibres associated with organs of attachment, feeding, and reproduction. Electrophysiological studies of flatworm muscles have exposed a diversity of voltage-activated ion channels that influence muscle contractile events. Neuronal cell types are mainly multi- and bi-polar and highly secretory in nature, producing a heterogeneity of vesicular inclusions whose contents have been identified cytochemically to include all three major types of cholinergic, aminergic, and peptidergic messenger molecules. A landmark discovery in flatworm neurobiology was the biochemical isolation and amino acid sequencing of two groups of native neuropeptides: neuropeptide F and FMRFamide-related peptides (FaRPs). Both families of neuropeptide are abundant and broadly distributed in platyhelminths, occurring in neuronal vesicles in representatives of all major flatworm taxa. Dual localization studies have revealed that peptidergic and cholinergic substances occupy neuronal sets separate from those of serotoninergic components. The physiological actions of neuronal messengers in flatworms are beginning to be established, and where examined, FaRPs and 5-HT are myoexcitatory, while cholinomimetic substances are generally inhibitory. There is immunocytochemical evidence that FaRPs and 5-HT have a regulatory role in the mechanism of egg assembly. Use of muscle strips and (or) muscle fibres from free-living and parasitic flatworms has provided baseline information to indicate that muscle responses to FaRPs are mediated by a G-protein-coupled receptor, and that the signal transduction pathway for contraction involves the second messengers cAMP and protein kinase C.
Resumo:
Attention-deficit hyperactivity disorder (ADHD) is a heritable childhood onset disorder that is marked by variability at multiple levels including clinical presentation, cognitive profile, and response to stimulant medications. It has been suggested that this variability may reflect etiological differences, particularly, at the level of underlying genetics. This study examined whether an attentional phenotype-spatial attentional bias could serve as a marker of symptom severity, genetic risk, and stimulant response in ADHD. A total of 96 children and adolescents with ADHD were assessed on the Landmark Task, which is a sensitive measure of spatial attentional bias. All children were genotyped for polymorphisms (30 untranslated (UTR) and intron 8 variable number of tandem repeats (VNTRs)) of the dopamine transporter gene (DAT1). Spatial attentional bias correlated with ADHD symptom levels and varied according to DAT1 genotype. Children who were homozygous for the 10-repeat allele of the DAT1 30-UTR VNTR displayed a rightward attentional bias and had higher symptom levels compared to those with the low-risk genotype. A total of 26 of these children who were medication naive performed the Landmark Task at baseline and then again after 6 weeks of stimulant medication. Left-sided inattention (rightward bias) at baseline was associated with an enhanced response to stimulants at 6 weeks. Moreover, changes in spatial bias with stimulant medications, varied as a function of DAT1 genotype. This study suggests an attentional phenotype that relates to symptom severity and genetic risk for ADHD, and may have utility in predicting stimulant response in ADHD.
The evolution of the UK charity Statement of Recommended Practice: The influence of key stakeholders
Resumo:
In the early 1980s, a landmark study identified significant poor reporting practice in UK charities. As a consequence, a journey was commenced with the aim of improving accounting and reporting as a basis for enhancing accountability by charities. Much of this change has been effected through the publication of evolving Statements of Recommended Practice (SORPs) on accounting and reporting by charities. This paper analyses the evolution of the SORP through time using insights from stakeholder theory, and argues that the key stakeholders influencing the evolving SORP have been government and the accounting profession.
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Since the early 1970s, the American electronic media artist Paul DeMarinis (b. 1948, Cleveland, Ohio, USA) has created works that re-imagine modes of communication and reinvent the technologies that enable communication. His works (see Table 1) have taken shape as recordings, performances, electronic inventions, and site-specific and interactive installations; many are considered landmarks in the histories of electronic music and media art. Paul DeMarinis pioneered live performance with computers, collaborated on landmark works with artists like David Tudor and Robert Ashley, undertook several tours with the Merce Cunningham Dance Company, and brought to life obscure technologies such as the flame loudspeaker (featured in his 2004 sculpture Firebirds). His interactive installation The Music Room (1982), commissioned by Frank Oppenheimer for the Exploratorium in San Francisco, was the first automatic music work to reach a significant audience. His album Music As A Second Language (1991) marks one of the most extensive explorations of the synthesized voice and speech melodies to date. Installations like The Edison Effect (1989-1993), in which lasers scan ancient recordings to produce music, and The Messenger (1998/2005), in which electronic mail messages are displayed on alphabetic telegraph receivers, illustrate a creative process that Douglas Kahn (1994) has called "reinventing invention." [etc]
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Recent landmark experiments have demonstrated how quantum mechanical impurities can be created within strongly correlated quantum gases and used to probe the coherence properties of these systems. Here we present a theoretical model to simulate such an output coupler for a Tonks- Girardeau gas that shows excellent agreement with the experimental results for atom transport and output coupling. The solid theoretical basis our model provides allows us to explore non-equilibrium transport phenomena in ultra-cold quantum gases and leads us to predict a regime of atom blockade, where the impurity component becomes localised in the parent cloud despite the presence of gravity. We show that this provides a stable mixed-species quantum gas in the strongly correlated limit.
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The megachiropteran fruit bat Rousettus aegyptiacus is able to orient and navigate using both vision and echolocation. These two sensory systems have different environmental constraints however, echolocation being relatively short range when compared with vision. Despite this difference, an experiment testing their memory of a perch location demonstrates that once the location of a perch is learned R. aegyptiacus is not influenced by the movement of local landmark cues in the vicinity of the perch under either light or dark conditions. Thus despite the differing constraints of vision and echolocation, this suggests a place is remembered as a location in space and not by associations with landmarks in the vicinity. A decrease in initial performance when the task was repeated in the dark suggested the possibility that a memory of a location learned using vision does not generalize to echolocation.
Resumo:
On 21 July 2011 the Inter-American Commission on Human Rights issued its much awaited decision in the case of Jessica Lenahan (Gonzales) v United States. In a landmark decision the Commission found the United States of America to be in violation of the American Declaration of the Rights and Duties of Man 1948 due to the failure of the state to protect a victim of domestic violence and her children. This paper analyses the Lenahan decision and its significance for the United States. In particular, the substantial influence of the case law of the European Court of Human Rights on the Commission’s reasoning is examined.
Resumo:
In 2004 nineteen scientists from fourteen institutions in seven countries
collaborated in the landmark study described in chapter 2 (Thomas et al., 2004a). This chapter provides an overview of results of studies published subsequently and assesses how much, and why, new results differ from those of Thomas et al.
Some species distribution modeling (SDM) studies are directly comparable to the Thomas et al. estimates. Others using somewhat different methods nonetheless illuminate whether the original estimates were of the right order of magnitude. Climate similarity models (Williams et al., 2007; Williams and Jackson, 2007), biome, and vegetation dynamic models (Perry and Enright, 2006) have also been
applied in the context of climate change, providing interesting opportunities
for comparison and cross-validation with results from SDMs.
This chapter concludes with an assessment of whether the range of extinction risk estimates presented in 2004 can be narrowed, and whether the mean estimate should be revised upward or downward. To set the stage for these analyses, the chapter begins with brief reviews of advances in climate modeling and species modeling since 2004.
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The adequacy of provisions for young people leaving care and in aftercare in the Republic of Ireland have been the subject of recent policy attention. A landmark report, the Ryan Report (2009), into historic abuse in state institutions recommended strengthening provisions in this area. However, the legislative basis for aftercare remains relatively weak and services for young people leaving care remain ad hoc and regionally variable. This article outlines the current context of leaving and aftercare provision in the Republic of Ireland and traces some of the recent policy debates and recommendations in this area. A genealogical analysis of leaving care and aftercare provision highlights that this issue has historically only emerged as a concern in the context in which young people leaving the care system are perceived as a ‘threat’ to social order. It is argued that the failure to adequately reform leaving and aftercare provision is reflective of wider social inequality and of a context in which young people in care are largely invisible from view.
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The sinking of the RMS Titanic in 1912 represents one of the most infamous maritime disasters in the history of shipping. Yet despite it entering the public imagination in the decades after its sinking, until recently it has all but been erased from the collective memory of the people of Belfast, the city in which it was built. In a post-conflict context, however, Belfast has begun to re-imagine the role of the ship in the city’s history, most particularly in the re-development of the docklands area and its designation as the Titanic Quarter, and through its landmark project the Titanic Belfast museum. This paper will trace the economic, social and political context from which the Titanic was built, and the role that this played in silencing any very public commemoration of its sinking until after the signing of the Belfast Agreement. The ‘story’ told in the new museum will be analysed from this perspective and will illustrate how the wounds of the Troubles continue to inform the interpretation of the city’s divided past.