9,628 research outputs found
EarthN: A new Earth System Nitrogen Model
The amount of nitrogen in the atmosphere, oceans, crust, and mantle have
important ramifications for Earth's biologic and geologic history. Despite this
importance, the history and cycling of nitrogen in the Earth system is poorly
constrained over time. For example, various models and proxies contrastingly
support atmospheric mass stasis, net outgassing, or net ingassing over time. In
addition, the amount available to and processing of nitrogen by organisms is
intricately linked with and provides feedbacks on oxygen and nutrient cycles.
To investigate the Earth system nitrogen cycle over geologic history, we have
constructed a new nitrogen cycle model: EarthN. This model is driven by mantle
cooling, links biologic nitrogen cycling to phosphate and oxygen, and
incorporates geologic and biologic fluxes. Model output is consistent with
large (2-4x) changes in atmospheric mass over time, typically indicating
atmospheric drawdown and nitrogen sequestration into the mantle and continental
crust. Critical controls on nitrogen distribution include mantle cooling
history, weathering, and the total Bulk Silicate Earth+atmosphere nitrogen
budget. Linking the nitrogen cycle to phosphorous and oxygen levels, instead of
carbon as has been previously done, provides new and more dynamic insight into
the history of nitrogen on the planet.Comment: 36 pages, 12 figure
Galaxy Peculiar Velocities and Infall onto Groups
We perform statistical analyses to study the infall of galaxies onto groups
and clusters in the nearby Universe. The study is based on the UZC and SSRS2
group catalogs and peculiar velocity samples. We find a clear signature of
infall of galaxies onto groups over a wide range of scales 5 h^{-1} Mpc<r<30
h^{-1} Mpc, with an infall amplitude on the order of a few hundred kilometers
per second. We obtain a significant increase in the infall amplitude with group
virial mass (M_{V}) and luminosity of group member galaxies (L_{g}). Groups
with M_{V}<10^{13} M_{\odot} show infall velocities V_{infall} \simeq 150 km
s^{-1} whereas for M_{V}>10^{13} M_{\odot} a larger infall is observed,
V_{infall} \simeq 200 km s^{-1}. Similarly, we find that galaxies surrounding
groups with L_{g}<10^{15} L_{\odot} have V_{infall} \simeq 100 km s^{-1},
whereas for L_{g}>10^{15} L_{\odot} groups, the amplitude of the galaxy infall
can be as large as V_{infall} \simeq 250 km s^{-1}. The observational results
are compared with the results obtained from mock group and galaxy samples
constructed from numerical simulations, which include galaxy formation through
semianalytical models. We obtain a general agreement between the results from
the mock catalogs and the observations. The infall of galaxies onto groups is
suitably reproduced in the simulations and, as in the observations, larger
virial mass and luminosity groups exhibit the largest galaxy infall amplitudes.
We derive estimates of the integrated mass overdensities associated with groups
by applying linear theory to the infall velocities after correcting for the
effects of distance uncertainties obtained using the mock catalogs. The
resulting overdensities are consistent with a power law with \delta \sim 1 at r
\sim 10 h^{-1}Mpc.Comment: 25 pages, 10 figure
What are children's trusts? Early findings from a national survey
<i>Background:</i> The Children Act 2004 and National Service Framework for Children, Young People and Maternity Services require fuller integration of health, education and social services for children and young people in England and Wales. The UK government supported the establishment of 35 experimental children's trust pathfinders (henceforth called children's trusts) in England.
<i>Methods:</i> A questionnaire was completed by managers in all 35 children's trusts a year after their start. Children's trust documents were examined. Census and performance indicators were compared between children's trust areas and the rest of England.
<i>Results</i> Children's trust areas had demographic and social characteristics typical of England. All children's trusts aimed to improve health, education and social services by greater managerial and service integration. All had boards representing the three sectors; other agencies’ representation varied. Two-thirds of children's trusts had moved towards pooling budgets in at least some service areas. At this stage in their development, some had prioritized joint procurement or provision of services, with formal managerial structures, while others favoured an informal strategic planning, co-ordination and information sharing approach. The commonest priorities for services development were for disabled children (16 children's trusts), followed by early intervention (11) and mental health services (8).
<i>Conclusions:</i> The diverse strategies adopted by these 35 children's trusts during their first year is due to their own characteristics and to the way government strategy developed during this period. Whilst some prioritized organizational development, joint financing and commissioning, and information sharing, others laid more emphasis on mechanisms for bringing front-line professionals closer together. Their experiences are of value to others deciding how best to integrate children's services
Electrostatic considerations affecting the calculated HOMO-LUMO gap in protein molecules.
A detailed study of energy differences between the highest occupied and
lowest unoccupied molecular orbitals (HOMO-LUMO gaps) in protein systems and
water clusters is presented. Recent work questioning the applicability of
Kohn-Sham density-functional theory to proteins and large water clusters (E.
Rudberg, J. Phys.: Condens. Mat. 2012, 24, 072202) has demonstrated vanishing
HOMO-LUMO gaps for these systems, which is generally attributed to the
treatment of exchange in the functional used. The present work shows that the
vanishing gap is, in fact, an electrostatic artefact of the method used to
prepare the system. Practical solutions for ensuring the gap is maintained when
the system size is increased are demonstrated. This work has important
implications for the use of large-scale density-functional theory in
biomolecular systems, particularly in the simulation of photoemission, optical
absorption and electronic transport, all of which depend critically on
differences between energies of molecular orbitals.Comment: 13 pages, 4 figure
Reducing the Harm of Criminal Victimization: The Role of Restitution
Restitution is a court-ordered payment by offenders to their victims to cover the victims\u27 economic losses resulting from the crime. These losses can be substantial and can harm victims and victims\u27 families both directly and indirectly. But most victims do not receive reparation for their injuries, both because judges do not always impose restitution and because of problems with collecting restitution payments, even if there is a court order to do so. In this article, we review the literature on restitution and suggest that this compensatory mechanism is necessary to restore victims to where they were before the crime occurred. But monetary restitution alone is not sufficient. Making victims whole requires not only financial compensation from the offender but also procedural, informational, and interpersonal justice from the criminal justice system
A tale of five fricatives: Consonantal contrast in heritage speakers of Mandarin
This study investigated the production of five Mandarin and English sibilant fricatives by heritage speakers of Mandarin in comparison to native speakers and late learners. Almost all speakers were found to distinguish the Mandarin retroflex and alveolo-palatal, as well as the Mandarin alveolo-palatal and English palato-alveolar. However, fewer distinguished the Mandarin retroflex and English palato-alveolar or the Mandarin and English alveolars, with the majority of heritage speakers falling into this group of "distinguishers" in both cases. These results indicate that heritage speakers, in addition to most late learners, do not have much trouble with the Mandarin post-alveolar contrast, and furthermore, that while native speakers and late learners of Mandarin tend to merge similar Mandarin and English sounds, heritage speakers tend to keep them apart. Thus, of the three groups heritage speakers appear to be the best at maintaining contrast between categories both within and across languages
Structural relaxations in electronically excited poly(para-phenylene)
Structural relaxations in electronically excited poly(para-phenylene) are
studied using many-body perturbation theory and density-functional-theory
methods. A sophisticated description of the electron-hole interaction is
required to describe the energies of the excitonic states, but we show that the
structural relaxations associated with exciton formation can be obtained quite
accurately within a constrained density-functional-theory approach. We find
that the structural relaxations in the low-energy excitonic states extend over
about 8 monomers, leading to an energy reduction of 0.22 eV and a Stokes shift
of 0.40 eV.Comment: 4 pages, 3 figure
Production of phonetic and phonological contrast by heritage speakers of Mandarin
This study tested the hypothesis that heritage speakers of a minority language, due to their childhood experience with two languages, would outperform late learners in producing contrast: language-internal phonological contrast, as well as cross-linguistic phonetic contrast between similar, yet acoustically distinct, categories of different languages. To this end, production of Mandarin and English by heritage speakers of Mandarin was compared to that of native Mandarin speakers and native American English-speaking late learners of Mandarin in three experiments. In experiment 1, back vowels in Mandarin and English were produced distinctly by all groups, but the greatest separation between similar vowels was achieved by heritage speakers. In experiment 2, Mandarin aspirated and English voiceless plosives were produced distinctly by native Mandarin speakers and heritage speakers, who both put more distance between them than late learners. In experiment 3, the Mandarin retroflex and English palato-alveolar fricatives were distinguished by more heritage speakers and late learners than native Mandarin speakers. Thus, overall the hypothesis was supported: across experiments, heritage speakers were found to be the most successful at simultaneously maintaining language-internal and cross-linguistic contrasts, a result that may stem from a close approximation of phonetic norms that occurs during early exposure to both languages
Constraint-Induced aphasia therapy: Three single case studies.
TITLE OF POSTER: CONSTRAINT INDUCED APHASIA THERAPY - THREE SINGLE CASE STUDIES
INTRODUCTION
This research project was inspired by the Specific Interest Group in Aphasia study day given by Professor Pulvermuller in January 2011. Constraint Induced Aphasia Therapy (CIAT) is sometimes referred to as Intensive Language Action Therapy (ILAT). This technique has an impressive research base to support its use for people with aphasia (PWA) and the evidence base includes both single case and randomised control trial evidence (Pulvermuller, Neininger, Elbert, Mohr, Rockstroh, Koebbl & Taub, 2001).
Pulvermuller et al (2001) describe CIAT as a game of pairs. The game is normally played by four players: a therapist and three PWA. A 32 pack of cards consisting of 16 pairs is shuffled and divided equally between the four players. No one can see anyone else’s cards. The aim of the game is to win the most pairs of cards. Clients can win a pair by asking each of the other players in turn, for a matching card. All requests and responses should be verbal but participants may describe the target word or use a gesture in order to achieve saying the word. An essential part of the game is that each player should see and hear the name of the card in play.
RESEARCH METHOD
Three PWA were prioritised from a typical general hospital SLT caseload. All three clients were one to two years post onset of their aphasia and had already been provided with impairment focussed, functional and psychosocial SLT input. They had moderate to severe aphasia, had difficulties at several levels of single word processing and frequently failed to convey their message despite having a degree of linguistic competence and an ability to use alternative communication strategies. Accessible formal assessment measures (Kaplan, Goodglass & Weintraub 1983, Goodglass, Kaplan & Barresi 2000 & Swinburn, Porter & Howard 2004) were used to evaluate the success of therapy in a four step repeated measures research design: Baseline 1, 30 hours CIAT therapy, Baseline 2, Baseline 3.
SUMMARY OF RESULTS
For 2/3 clients, assessment results suggested that participation in the CIAT programme resulted in a positive measurable change in language behaviour. This positive change was not apparent in assessments of understanding. Selective improvement of language ability suggests that the therapy directed at language output had resulted in improved word and sentence level skills for 2/3 of our clients. There were also positive changes that were not captured by the assessment data: reduced use of written and therapist cues, improved repetition skills, improved self-monitoring and a reduced tendency to produce jargon type utterances. Relatives corroborated therapist perceptions.
CONCLUSIONS
In 2006 Beeson & Robey (2006, p162) proposed that rehabilitation outcome research should be conducted in five phases. Our study is one of the first to provide evidence to support the use of intensive CIAT therapy in the community (phase 4 – an effectiveness study). Other studies have assessed the usefulness of the therapeutic effect of ILAT (phase 1), optimised the ILAT procedure (phase 2) and tested its usefulness under ideal conditions (phase 3). The final phase outlined by Beeson & Robey (2006) is the cost-benefit analysis (phase 5) and we would welcome debate within the profession on improving this type of input and the role of Speech and Language Therapists in intensive aphasia therapy provision.
REFERENCES
Pulvermuller, F., Neininger, B., Elbert, T., Mohr, B., Rockstroh, B., Koebbl,P. & Taub, E. (2001) Constraint induced therapy for chronic aphasia after stroke. Stroke, 1621-1626.
Beeson, P. M. & Robey, R.R. (2006) Evaluating single-subject treatment research: Lessons learnt from the aphasia literature. Neuropsychological Review, 16, 161-169.
KAPLAN, E., GOODGLASS, H. and WEINTRAUB, S. (1983) The Boston Naming Test. Philadelphia: Lea and Febiger.
Goodglass, H., Kaplan, E. & Barresi, B. (2000) Boston Diagnostic Aphasia Examination. 3rd Edition. San Antonio: Pearson.
Swinburn, K., Porter, G., & Howard, D. (2004). The Comprehensive Aphasia Test. Hove: Psychology Press
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