950 research outputs found
Memory, plasticity, and sleep – a role for calcium permeable AMPA receptors?
No full textExperience shapes and molds the brain throughout life.These changes in neuronal circuits are produced by a myriad of molecular and cellular processes. Simplistically, circuits are modified through changes in neurotransmitter release or through neurotransmitter detection at synapses. The predominant neurotransmitter receptor in excitatory transmission, the AMPA-type glutamate receptor (AMPAR), is exquisitely sensitive to changes in experience and synaptic activity. These ion channels are usually impermeable to calcium, a property conferred by the GluA2 subunit. However, GluA2-lacking AMPARs are permeable to calcium and have recently been shown to play a unique role in synaptic function. In this review, I will describe new findings on the role of calcium permeable AMPARs (CP-AMPARs) in experience-dependent and synaptic plasticity.These studies suggest that CP-AMPARs play a prominent role in maintaining circuits in a labile state where further plasticity can occur, thus promoting metaplasticity. Moreover, the abnormal expression of CP-AMPARs has been implicated in drug addiction and memory disorders and thus may be a novel therapeutic target.National Institutes of Health (U.S.) (1-K99-NS076364-01
Ethnic identity, political identity and ethnic conflict: simulating the effect of congruence between the two identities on ethnic violence and conflict
No full textThis thesis outlines and presents an alternative hypothetical process to the emergence of ethnic conflict. Ethnic conflicts, rather than being dependent upon pre-existing 'ancient hatreds', are instead the result of a congruence between ethnic and political identity which grants individuals the ability to use ethnicity to identify and eliminate political threats. This hypothesis is formed by the examination of three case studies of ethnic conflict: Lebanon, Northern Ireland and Croatia. This hypothesis is then formalised and tested using an agent based simulation in which agent interactions are dependent upon ethnic and political identity and the congruence between the two. As predicted there was a strong positive correlation between how accurately ethnic identity reflected political identity and the level of ethnically motivated violence in the simulation, although the relationship was not linear. Furthermore the effect of a shift in congruence was found to be roughly comparable to the effect of initialising agents with a moderate level of pre-existing ethnic antagonism
MBA Admission Criteria and an Entrepreneurial Mind-Set: Evidence from "Western" Style MBAs in India and Thailand
No full textIn this volume, Dean Shepherd focuses on the varying topics of entrepreneurship unified through conjoint analysis. Although the topic of entrepreneurial decision making is broad, in doing so, he reveals the mechanisms that come into play during the entrepreneurial decision-making process. Scholars of entrepreneurship and organizational behavior will find this collection an essential resource for understanding how decision making is achieved in entrepreneurial settings. [Book Synopsis
IT'S P. D. Q. BACH!!! with special guest The Grasshopper Friday, November 15, 1991 8:00 p.m. Stude Concert Hall
No full textPresented by the Shepherd School Student CouncilRecording ends on Side B before performance finishes.Program: Fanfare for the common cold, S. 98.7, P. D. Q. Bach (1742-1807) -- Liebeslieder polkas, S. 2/4, P. D. Q. Bach (1742-1807) -- Sonata inamorata, S. 1+1, P. D. Q. Bach (1742-1807) -- Octoot, S. 8, P. D. Q. Bach (1742-1807) -- Erotica variations for banned instruments and piano, P. D. Q. Bach (1742-1807) -- Dutch suite in G major, S.8, P. D. Q. Bach (1742-1807) -- The grasshopper: a tragic tale, Innes Randolph (1837-1887) and Joseph W. Clokey (1890-1960)
Zechariah 9-14 as the substructure of 1 Peter’s eschatological program
No full textThe principal aim of this study is to discern what has shaped the author of 1 Peter to regard Christian suffering as a necessary (1.6) and to-be-expected (4.12) component of faithful allegiance to Jesus Christ. Most research regarding suffering in 1 Peter has limited the scope of inquiry to two particular aspects—its cause and nature, and the strategies that the author of 1 Peter employs in order to enable his addressees to respond in faithfulness. There remains, however, the need for a comprehensive explanation for the source that has generated 1 Peter’s theology of Christian suffering. If Jesus truly is the Christ, God’s chosen redemptive agent who has come to restore God’s people, then how can it be that Christian suffering is a necessary part of discipleship after his coming, death and resurrection? What led the author of 1 Peter to such a startling conclusion, which seems to runs against the grain of the eschatological hopes and expectations of Jewish restoration ideology?
This thesis analyzes the appropriation of shepherd and fiery trials imagery,
and argues that the author of 1 Peter is dependent upon Zechariah 9-14 for his
theology of Christian suffering. Said in another way, the eschatological program of
Zechariah 9-14, read through the lens of the Gospel, functions as the substructure
for 1 Peter’s eschatology and thus its theology of Christian suffering.
In support of this hypothesis, this study highlights the fact that Zechariah 9-
14 was available and appropriated in early Christianity, in particular in the Passion
Narrative tradition; that the shepherd imagery of 1 Pet 2.25 is best understood
within the milieu of the Passion Narrative tradition, and that it alludes to the
eschatological program of Zechariah 9-14; that the fiery trials imagery found in 1
Peter 1.6-7 and 1 Pet 4.12 is distinct from that which we find in Greco-Roman and OT
wisdom sources, and that it shares exclusive parallels with some unique features of
the eschatological program of Zechariah 9-14; that Zechariah 9-14 offers a more
satisfying explanation for the modification of Isa 11.2 in 1 Pet 4.14, the transition
from 4.12-19 to 5.1-4, why Peter has oriented his letter with the term διασπορά,
and why he has described his addresses as οἶκος τοῦ θεοῦ; and finally that 1 Peter
contains an implicit foundational narrative that shares distinct parallels with the
eschatological program of Zechariah 9-14.
We can conclude that 1 Peter offers a unique vista into the way in which at
least one early Christian witness came to understand and to communicate the fact
that Christian suffering was a necessary feature of faithful allegiance to Jesus Christ
The impact of a child's death; An Interpretative Phenomenological Analysis undertaken with five head teachers
No full textAbstract
This research explores with five head teachers their views and experiences of a period when a child was terminally ill and subsequently died when in their school community.
The participants were selected purposively from Derbyshire head teachers who had experienced the death of a pupil in their school community. After interviewing the participants using a semi-structured interview schedule the transcribed interviews provided the data for the research.
The interviews were analysed, using the methodology of Interpretative Phenomenological Analysis, to explore the experiences of each of the participants. Three superordinate themes were identified which were;
Emotions and their management
Interactions with the bereaved family
Interaction with the school community
Additionally, an overarching theme of Elevation was identified.
Each theme is presented and illustrated with abstracts taken from the original data. This is accompanied by interpretation which is also discussed and compared with knowledge from the existing literature.
The research has illustrated the complications that exist for head teachers in managing their emotions and the possibility of these emotions intruding on their personal and family life. It has illustrated the way in which the relationship between the head teacher and the bereaved family changes and how it changes their interactions within the school community.
This research led to the consideration of the influence of the cultural expectation enshrined in the saying, 'De mortuis nil nisi bonum dicendum est' (Of the dead, nothing unless good). Also considered is the behavioural derivative of this saying and how it shapes the responses that head teachers make when managing a school community when a child has died. It also led to the consideration of the implications of the research findings for any support professionals who help schools
SHEPHERD SCHOOL CHAMBER ORCHESTRA Sunday, December 6, 1998 8:00 p.m. Stude Concert Hall
No full textRecording of performance is incomplete. Audio quality of the recording gradually increases.Program: Concerto, Op. 24 / Anton Webern -- Cello Concerto in C Major, Hob. VIIb:I / Franz Joseph Haydn -- String Quartet in D minor, D. 810 "Death and the Maiden / Franz Schubert, arr. Gustav Mahler, ed. Donald Mitchell and David Matthew
JASON ROBERTS Organist SENIOR RECITAL Monday, March 11, and Wednesday, March 13, 2002 7:30 p.m. Edythe Bates Old Recital Hall and Grand Organ
No full textPROGRAM: Fantasy in F Minor, K.608 / Wolfgang Amadeus Mozart -- Trio Sonata No.3 in D minor, BWV527 / Johann Sebastian Bach -- Sonata in A major, Op.65 No.3 / Felix Mendelssohn -- Chorale Prelude: "Drop, Drop Slow Tears," Op.104 / Vincent Persichetti -- Prelude and Fugue on the name "Alain," Op.7 / Maurice DurufleThis recital is given in partial fulfillment of the requirements for the degree Bachelor of Music
Adefovir dipivoxil and pegylated interferon alpha for the treatment of chronic hepatitis B: an updated systematic review and economic evaluation
No full textObjective:To update and extend a 2006 report on the clinical effectiveness and cost-effectiveness of adefovir dipivoxil (ADV) and pegylated interferon alpha (PEG-?) for the treatment of chronic hepatitis B (CHB).Data sources:Thirteen bibliographic databases were searched including MEDLINE, EMBASE and the Cochrane Library. Searches were run from the beginning of 2005 to September 2007.Review methods:For the clinical effectiveness review, randomised controlled trials (RCTs) comparing ADV, PEG-?-2a and PEG-?-2b with currently licensed treatments for CHB, including non-pegylated interferon alpha (IFN-?) and lamivudine (LAM), were included. Outcomes included biochemical, histological and virological response to treatment, drug resistance and adverse effects. A systematic review of economic evaluations of antiviral treatments for CHB was conducted. The economic Markov model used in the 2006 report was updated in terms of utility values, discount rates and costs.Results:Of the 82 papers retrieved for detailed screening, eight RCTs were included. Three evaluated ADV, four evaluated PEG-?-2b and one (from the original literature search) compared PEG-?-2b plus LAM with PEG-?-2b monotherapy. No RCTs of PEG-?-2a were identified. One ADV trial showed a statistically significant difference between ADV and placebo in terms of ALT response and HBV DNA levels, favouring ADV. Following withdrawal of ADV, levels were similar to those in placebo patients. In the ADV versus ADV plus LAM trial, there was a statistically significant difference in favour of the combination treatment. In the PEG-? trials, there were statistically significant differences favouring PEG-?-2b plus LAM compared with either one of the drugs given as monotherapy. For the comparison between PEG-?-2b and IFN-? and the comparison between different staggered regimens of the commencement of PEG-?-2b and LAM, there were no statistically significant differences between groups. Four full economic evaluations were identified, in addition to one identified in the original report. Two assessed PEG-?-2a; the remainder assessed ADV. PEG-?-2a was associated with increased treatment costs and gains in quality-adjusted life expectancy. In a UK study, the incremental cost-effectiveness ratio (ICER) for PEG-?-2a was £10,444 per QALY gained compared with LAM. Evaluations of ADV found that LAM monotherapy was dominated; the ICER for ADV monotherapy compared with 'doing nothing' was $19,731. The results of the updated analysis were generally robust to changes in deterministic sensitivity analysis. In a probabilistic sensitivity analysis, the same sequence of treatments was identified as optimal. In a probabilistic sensitivity analysis, PEG-?-2b had a probability of being cost-effective of 79% at a willingness-to-pay threshold of £20,000 per QALY, and 86% at a willingness-to-pay threshold of £30,000 per QALY.Conclusions:Both ADV and PEG-? are beneficial for patients with CHB in terms of suppressing viral load, reducing liver damage-associated biochemical activity, inducing HBeAg seroconversion, and reducing liver fibrosis and necroinflammation. The effects of long-term treatment with ADV are generally durable, with relatively low rates of resistance. In most cases, cost-effectiveness estimates were within acceptable ranges. Further research should assess the clinical effectiveness and cost-effectiveness of newer antiviral agents in relation to existing drugs, including the role of initiating treatment with combination therapy.<br/
Modelling the IEEE 802.11 wireless MAC layer under heterogeneous VoIP traffic to evaluate and dimension QoE
No full textPhDAs computers become more popular in the home and workplace, sharing resources and
Internet access locally is a necessity. The simplest method of choice is by deploying a
Wireless Local Area Network; they are inexpensive, easy to configure and require
minimal infrastructure. The wireless local area network of choice is the IEEE 802.11
standard; IEEE 802.11, however, is now being implemented on larger scales outside of
the original scope of usage. The realistic usage spans from small scale home solutions to
commercial ‘hot spots,’ providing access within medium size areas such as cafés, and
more recently blanket coverage in metropolitan. Due to increasing Internet availability
and faster network access, in both wireless and wired, the concept of using such
networks for real-time services such as internet telephony is also becoming popular.
IEEE 802.11 wireless access is shared with many clients on a single channel and there are
three non-overlapping channels available. As more stations communicate on a single
channel there is increased contention resulting in longer delays due to the backoff
overhead of the IEEE 802.11 protocol and hence loss and delay variation; not desirable
for time critical traffic.
Simulation of such networks demands super-computing resource, particularly where
there are over a dozen clients on a given. Fortunately, the author has access to the UK’s
super computers and therefore a clear motivation to develop a state of the art analytical
model with the required resources to validate. The goal was to develop an analytical
model to deal with realistic IEEE 802.11 deployments and derive results without the
need for super computers.
A network analytical model is derived to model the characteristics of the IEEE 802.11
protocol from a given scenario, including the number of clients and the traffic load of
each. The model is augmented from an existing published saturated case, where each
client is assumed to always have traffic to transmit. The nature of the analytical model is
to allow stations to have a variable load, which is achieved by modifying the existing
models and then to allow stations to operate with different traffic profiles. The different
traffic profiles, for each station, is achieved by using the augmented model state machine
per station and distributing the probabilities to each station’s state machine accordingly.
To address the gap between the analytical models medium access delay and standard
network metrics which include the effects of buffering traffic, a queueing model is
identified and augmented which transforms the medium access delay into standard
network metrics; delay, loss and jitter. A Quality of Experience framework, for both
computational and analytical results, is investigated to allow the results to be represented
as user perception scores and the acceptable voice call carrying capacity found. To find
the acceptable call carrying capacity, the ITU-T G.107 E-Model is employed which can
be used to give each client a perception rating in terms of user satisfaction.
PAGE 4 OF 162
QUEEN MARY, UNIVERSITY OF LONDON OLIVER SHEPHERD
With the use of a novel framework, benchmarking results show that there is potential to
maximise the number of calls carried by the network with an acceptable user perception
rating. Dimensioning of the network is undertaken, again compared with simulation
from the super computers, to highlight the usefulness of the analytical model and
framework and provides recommendations for network configurations, particularly for
the latest Wireless Multimedia extensions available in IEEE 802.11.
Dimensioning shows an overall increase of acceptable capacity of 43%; from 7 to 10 bidirectional
calls per Access Point by using a tuned transmission opportunity to allow
each station to send 4 packets per transmission. It is found that, although the accuracy
of the results from the analytical model is not precise, the model achieves a 1 in 13,000
speed up compared to simulation. Results show that the point of maximum calls comes
close to simulation with the analytical model and framework and can be used as a guide
to configure the network. Alternatively, for specific capacity figures, the model can be
used to home-in on the optimal region for further experiments and therefore achievable
with standard computational resource, i.e. desktop machines
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