892 resultados para MOVING MIRRORS
Resumo:
Active head turns to the left and right have recently been shown to influence numerical cognition by shifting attention along the mental number line. In the present study, we found that passive whole-body motion influences numerical cognition. In a random-number generation task (Experiment 1), leftward and downward displacement of participants facilitated small number generation, whereas rightward and upward displacement facilitated the generation of large numbers. Influences of leftward and rightward motion were also found for the processing of auditorily presented numbers in a magnitude-judgment task (Experiment 2). Additionally, we investigated the reverse effect of the number-space association (Experiment 3). Participants were displaced leftward or rightward and asked to detect motion direction as fast as possible while small or large numbers were auditorily presented. When motion detection was difficult, leftward motion was detected faster when hearing small number and rightward motion when hearing large number. We provide new evidence that bottom-up vestibular activation is sufficient to interact with the higher-order spatial representation underlying numerical cognition. The results show that action planning or motor activity is not necessary to influence spatial attention. Moreover, our results suggest that self-motion perception and numerical cognition can mutually influence each other.
Resumo:
In order to improve the ability to link chemical exposure to toxicological and ecological effects, aquatic toxicology will have to move from observing what chemical concentrations induce adverse effects to more explanatory approaches, that are concepts which build on knowledge of biological processes and pathways leading from exposure to adverse effects, as well as on knowledge on stressor vulnerability as given by the genetic, physiological and ecological (e.g., life history) traits of biota. Developing aquatic toxicology in this direction faces a number of challenges, including (i) taking into account species differences in toxicant responses on the basis of the evolutionarily developed diversity of phenotypic vulnerability to environmental stressors, (ii) utilizing diversified biological response profiles to serve as biological read across for prioritizing chemicals, categorizing them according to modes of action, and for guiding targeted toxicity evaluation; (iii) prediction of ecological consequences of toxic exposure from knowledge of how biological processes and phenotypic traits lead to effect propagation across the levels of biological hierarchy; and (iv) the search for concepts to assess the cumulative impact of multiple stressors. An underlying theme in these challenges is that, in addition to the question of what the chemical does to the biological receptor, we should give increasing emphasis to the question how the biological receptor handles the chemicals, i.e., through which pathways the initial chemical-biological interaction extends to the adverse effects, how this extension is modulated by adaptive or compensatory processes as well as by phenotypic traits of the biological receptor.
Resumo:
In writing “Not in the Legends”, one of the images and concepts which constantly returned was that of pilgrimage. I began to write these poems while studying abroad in London, after having passed the previous semester in France and travelling around Europe. There was something in the repetition of sightseeing— walking six miles in Luxembourg to see the grave of General Patton, taking photographs of the apartment where Sylvia Plath ended her life, bowing before the bones of saints, searching through Père Lachaise for the grave of Théodore Gericault— which struck me as numinous and morbid. At the same time, I came to love living abroad and I grew discontent with both remaining and returning. I wanted the opportunity to live everywhere all the time and not have to choose between home and away. Returning from abroad, I turned my attention to the landscape of my native country. I found in the New England pilgrims a narrative of people who had left their home in search of growth and freedom. In these journeys I began to appreciate the significance of place and tried to understand what it meant to move from one place to another, how one chose a home, and why people searched for meaning in specific locations. The processes of moving from student to worker and from childhood to adulthood have weighed on me. I began to see these transitions towards maturity as travels to a different land. Memory and nostalgia are their own types of pilgrimage in their attempts to return to lost places, as is the reading of literature. These pilgrimages, real and metaphorical, form the thematic core of the collection. I read the work of many poets who came before me, returning to the places where the Canon was forged. Those poets have a large presence in the work I produced. I wondered how I, as a young poet, could earn my own place in the tradition and sought models in much the same way a painter studies the brushstrokes of a master. In the process, I have tried to uncover what it means to be a poet. Is it something like being a saint? Is it something like being a colonist? Or is to be the one who goes in search of saints and colonists? In trying to measure my own life and work based on the precedent, I have questioned what role era and generation have on the formation of identity. I focused my reading heavily on the early years of English poetry, trying to find the essence of the time when the language first achieved the transcendence of verse. In following the development of English poetry through Coleridge, John Berryman, and Allison Titus, I have explored the progression of those basic virtues in changing contexts. Those bearings, applied to my modern context, helped to shape the poetry I produced. Many of the poems in “Not in the Legends” are based on my own personal experience. In my recollections I have tried to interrogate nostalgia rather than falling into mere reminiscence. Rather than allowing myself poems of love and longing, I have tried to find the meaning of those emotions. A dominant conflict exists between adventure and comfort which mirrors the central engagement with the nature of being “here” or “there”. It is found in scenes of domesticity and wilderness as I attempt to understand my own simultaneous desire for both. For example, in “Canned Mangoes…” the intrusion of nature, even in a context as innocuous as a poem by Sir Walter Raleigh, unravels ordinary comforts of the domestic sphere. The character of “The Boy” from Samuel Beckett’s Waiting for Godot proved such an interesting subject for me because he is one who can transcend the normal boundaries of time and place. The title suggests connections to both place and time. “Legends” features the dual meaning of both myths and the keys to maps. To propose something “Not in the Legends” is to find something which has no precedent in our histories and our geographies, something beyond our field of knowledge and wholly new. One possible interpretation I devised was that each new generation lives a novel existence, the future being the true locus of that which is beyond our understanding. The title comes from Keats’ “Hyperion, a Fragment”, and details the aftermath of the Titanomachy. The Titans, having fallen to the Olympians, are a representation of the passing of one generation for the next. Their dejection is expressed by Saturn, who laments: Not in my own sad breast, Which is its own great judge and searcher out, Can I find reason why ye should be thus: Not in the legends of the first of days… (129-132) The emotions of the conquered Titans are unique and without antecedent. They are experiencing feelings which surpass all others in history. In this, they are the equivalent of the poet who feels that his or her own sufferings are special. In contrast are Whitman’s lines from “Song of Myself” which serve as an epigraph to this collection. He contends for a sense of continuity across time, a realization that youth, age, pleasure, and suffering have always existed and will always exist. Whitman finds consolation in this unity, accepting that kinship with past generations is more important that his own individuality. These opposing views offer two methods of presenting the self in history. The instinct of poetry suggests election. The poet writes because he feels his experiences are special, or because he believes he can serve as a synecdoche for everyone. I have fought this instinct by trying to contextualize myself in history. These poems serve as an attempt at prosopography with my own narrative a piece of the whole. Because the earth abides forever, our new stories get printed over the locations of the old and every place becomes a palimpsest of lives and acts. In this collection I have tried to untangle some of those layers, especially my own, to better understand the sprawling legend of history.
Resumo:
The United States¿ Federal and State laws differentiate between acceptable (or, legal) and unacceptable (illegal) behavior by prescribing restrictive punishment to citizens and/or groups that violate these established rules. These regulations are written to treat every person equally and to fairly serve justice; furthermore, the sanctions placed on offenders seek to reform illegal behavior through limitations on freedoms and rehabilitative programs. Despite the effort to treat all offenders fairly regardless of social identity categories (e.g., sex, race, ethnicity, socioeconomic status, age, ability, and gender and sexual orientation) and to humanely eliminate illegal behavior, the American penal system perpetuates de facto discrimination against a multitude of peoples. Furthermore, soaring recidivism rates caused by unsuccessful re-entry of incarcerated offenders puts economic stress on Federal and State budgets. For these reasons, offenders, policy-makers, and law-abiding citizens should all have a vested interest in reforming the prison system. This thesis focuses on the failure of the United States corrections system to adequately address the gender-specific needs of non-violent female offenders. Several factors contribute to the gender-specific discrimination that women experience in the criminal justice system: 1) Trends in female criminality that skew women¿s crime towards drug-related crimes, prostitution, and property offenses; 2) Mandatory minimum sentences for drug crimes that are disproportionate to the crime committed; 3) So-called ¿gender-neutral¿ educational, vocational, substance abuse, and mental health programming that intends to equally rehabilitate men and women, but in fact favors men; and 4) The isolating nature of prison structures that inhibits smooth re-entry into society. I argue that a shift in the placement and treatment of non-violent female offenders is necessary for effective rehabilitation and for reducing recidivism rates. The first component of this shift is the design and implementation of gender- responsive treatment (GRT) rather than gender-neutral approaches in rehabilitative programming. The second shift is the utilization of alternatives to incarceration, which provide both more humane treatment of offenders and smoother reintegration to society. Drawing on recent scholarship, information from prison advocacy organizations, and research with men in an alternative program, I provide a critical analysis of current policies and alternative programs, and suggest several proposals for future gender- responsive programs in prisons and in place of incarceration. I argue that the expansion of gender-responsive programming and alternatives to incarceration respond to the marginalization of female offenders, address concerns about the financial sustainability of the United States criminal justice system, and tackle high recidivism rates.
Resumo:
We report the selection and spectroscopic confirmation of 129 new late-type (SpT = K3-M6) members of the Tucana-Horologium moving group, a nearby (d similar to 40 pc), young (tau similar to 40 Myr) population of comoving stars. We also report observations for 13 of the 17 known Tuc-Hor members in this spectral type range, and that 62 additional candidates are likely to be unassociated field stars; the confirmation frequency for new candidates is therefore 129/191 = 67%. We have used radial velocities, Ha emission, and Li-6708 absorption to distinguish between contaminants and bona fide members. Our expanded census of Tuc-Hor increases the known population by a factor of similar to 3 in total and by a factor of similar to 8 for members with SpT >= K3, but even so, the K-M dwarf population of Tuc-Hor is still markedly incomplete. Our expanded census allows for a much more detailed study of Tuc-Hor than was previously feasible. The spatial distribution of members appears to trace a two-dimensional sheet, with a broad distribution in X and Y, but a very narrow distribution (+/- 5 pc) in Z. The corresponding velocity distribution is very small, with a scatter of +/- 1.1 km s(-1) about the mean UVW velocity for stars spanning the entire 50 pc extent of Tuc-Hor. We also show that the isochronal age (tau similar to 20-30 Myr) and the lithium depletion boundary age (tau similar to 40 Myr) disagree, following the trend in other pre-main-sequence populations for isochrones to yield systematically younger ages. The H alpha emission line strength follows a trend of increasing equivalent width with later spectral type, as is seen for young clusters. We find that moving group members have been depleted of measurable lithium for spectral types of K7.0-M4.5. None of our targets have significant infrared excesses in the WISE W3 band, yielding an upper limit on warm debris disks of F < 0.7%. Finally, our purely kinematic and color-magnitude selection procedure allows us to test the efficiency and completeness for activity-based selection of young stars. We find that 60% of K-M dwarfs in Tuc-Hor do not have ROSAT counterparts and would have been omitted in X-ray-selected samples. In contrast, GALEX UV-selected samples using a previously suggested criterion for youth achieve completeness of 77% and purity of 78%, and we suggest new SpT-dependent selection criteria that will yield > 95% completeness for tau similar to 40 Myr populations with GALEX data available.
Resumo:
This study investigates four decades of socio-economic and environmental change in a shifting cultivation landscape in the northern uplands of Laos. Historical changes in land cover and land use were analyzed using a chronological series of remote sensing data. Impacts of landscape change on local livelihoods were investigated in seven villages through interviews with various stakeholders. The study reveals that the complex mosaics of agriculture and forest patches observed in the study area have long constituted key assets for the resilience of local livelihood systems in the face of environmental and socio-economic risks. However, over the past 20 years, a process of segregating agricultural and forest spaces has increased the vulnerability of local land users. This process is a direct outcome of policies aimed at increasing national forest cover, eradicating shifting cultivation and fostering the emergence of more intensive and commercial agricultural practices. We argue that agriculture-forest segregation should be buffered in such a way that a diversity of livelihood opportunities and economic development pathways can be maintained.
Resumo:
Calcium influx into the dendritic tufts of layer 5 neocortical pyramidal neurons modifies a number of important cellular mechanisms. It can trigger local synaptic plasticity and switch the firing properties from regular to burst firing. Due to methodological limitations, our knowledge about Ca2+ spikes in the dendritic tuft stems mostly from in vitro experiments. However, it has been speculated that regenerative Ca2+ events in the distal dendrites correlate with distinct behavioral states. Therefore it would be most desirable to be able to record these Ca2+ events in vivo, preferably in the behaving animal. Here, we present a novel approach for recording Ca2+ signals in the dendrites of populations of layer 5 pyramidal neurons in vivo, which ensures that all recorded fluorescence changes are due to intracellular Ca2+ signals in the apical dendrites. The method has two main features: 1) bolus loading of layer 5 with a membrane-permeant Ca2+ dye resulting in specific loading of pyramidal cell dendrites in the upper layers and 2) a fiberoptic cable attached to a gradient index lens and a prism reflecting light horizontally at 90 degrees to the angle of the apical dendrites. We demonstrate that the in vivo signal-to-noise ratio recorded with this relatively inexpensive and easy-to-implement fiberoptic-based device is comparable to conventional camera-based imaging systems used in vitro. In addition, the device is flexible and lightweight and can be used for recording Ca2+ signals in the distal dendritic tuft of freely behaving animals.
Resumo:
The aim of this work is to investigate to what extent it is possible to use the secondary collimator jaws to reduce the transmitted radiation through the multileaf collimator (MLC) during an intensity modulated radiation therapy (IMRT). A method is developed and introduced where the jaws follow the open window of the MLC dynamically (dJAW method). With the aid of three academic cases (Closed MLC, Sliding-gap, and Chair) and two clinical cases (prostate and head and neck) the feasibility of the dJAW method and the influence of this method on the applied dose distributions are investigated. For this purpose the treatment planning system Eclipse and the Research-Toolbox were used as well as measurements within a solid water phantom were performed. The transmitted radiation through the closed MLC leads to an inhomogeneous dose distribution. In this case, the measured dose within a plane perpendicular to the central axis differs up to 40% (referring to the maximum dose within this plane) for 6 and 15 MV. The calculated dose with Eclipse is clearly more homogeneous. For the Sliding-gap case this difference is still up to 9%. Among other things, these differences depend on the depth of the measurement within the solid water phantom and on the application method. In the Chair case, the dose in regions where no dose is desired is locally reduced by up to 50% using the dJAW method instead of the conventional method. The dose inside the chair-shaped region decreased up to 4% if the same number of monitor units (MU) as for the conventional method was applied. The undesired dose in the volume body minus the planning target volume in the clinical cases prostate and head and neck decreased up to 1.8% and 1.5%, while the number of the applied MU increased up to 3.1% and 2.8%, respectively. The new dJAW method has the potential to enhance the optimization of the conventional IMRT to a further step.