21,477 research outputs found
Implementing a resource list management system in an academic library
Purpose â The purpose of this paper is to review the key components of the introduction of a new resource list management system (RLMS) at Nottingham Trent University (NTU) using the Aspire application from Talis Education. It explains the key service goals; the implementation milestones; the main technical challenges which needed to be addressed; and the dynamic relationship between the rollout of the RLMS and existing selection, acquisition and resource delivery processes
Does "thin client" mean "energy efficient"?
The thick client âa personal computer with integral disk storage and local processing capability, which also has access to data and other resources via a network connection â is accepted as the model for providing computing resource in most office environments. The Further and Higher Education sector is no exception to that, and therefore most academic and administrative offices are equipped with desktop computers of this form to support users in their day to day tasks. This system structure has a number of advantages: there is a reduced reliance on network resources; users access a system appropriate to their needs, and may customise âtheirâ system to meet their own personal requirements and working patterns. However it also has disadvantages: some are outside the scope of this project, but of most relevance to the green IT agenda is the fact that relatively complex and expensive (in first cost and in running cost) desktop systems and servers are underutilised â especially in respect of processing power. While some savings are achieved through use of âsleepâ modes and similar power reducing mechanisms, in most configurations only a small portion of the overall total available processor resource is utilised. This realisation has led to the promotion of an alternative paradigm, the thin client. In a thin client system, the desktop is shorn of most of its local processing and data storage capability, and essentially acts as a terminal to the server, which now takes on responsibility for data storage and processing. The energy benefit is derived through resource sharing: the processor of the server does the work, and because that processor is shared by all users, a number of users are supported by a single system. Therefore â according to proponents of thin client â the total energy required to support a user group is reduced, since a shared physical resource is used more efficiently. These claims are widely reported: indeed there are a number of estimation tools which show these savings can be achieved; however there appears to be little or no actual measured data to confirm this. The community does not appear to have access to measured data comparing thin and thick client systems in operation in the same situation, allowing direct comparisons to be drawn. This is the main goal of this project. One specific question relates to the overall power use, while it would seem to be obvious that the thin client would require less electricity, what of the server? Two other variations are also considered: it is not uncommon for thin client deployments to continue to use their existing PCs as thin client workstations, with or without modification. Also, attempts by PC makers to reduce the power requirements of their products have given rise to a further variation: the incorporation of low power features in otherwise standard PC technology, working as thick clients. This project was devised to conduct actual measurements in use in a typical university environment. We identified a test area: a mixed administrative and academic office location which supported a range of users, and we made a direct replacement of the current thick client systems with thin client equivalents; in addition, we exchanged a number of PCs operating in thin and thick client mode with devices specifically branded as âlow powerâ PCs and measured their power requirements in both thin and thick modes. We measured the energy consumption at each desktop for the duration of our experiments, and also measured the energy draw of the server designated to supporting the thin client setup, giving us the opportunity to determine the power per user of each technology. Our results show a significant difference in power use between the various candidate technologies, and that a configuration of low power PC in thick client mode returned the lowest power use during our study. We were also aware of other factors surrounding a change such as this: we have addressed the technical issues of implementation and management, and the non-technical or human factors of acceptance and use: all are reported within this document. Finally, our project is necessarily limited to a set of experiments carried out in a particular situation, therefore we use estimation methods to draw wider conclusions and make general observations which should allow others to select appropriate thick or thin client solutions in their situation
Interaction Between The MEC1-Dependent DNA Synthesis Checkpoint And G1 Cyclin Function In Saccharomyces Cerevisiae
The completion of DNA synthesis in yeast is monitored by a checkpoint that requires MEC1 and RAD53. Here we show that deletion of the Saccharomyces cerevisiae G1 cyclins CLN1 and CLN2 suppressed the essential requirement for MEC1 function. Wild-type levels of CLN1 and CLN2, or overexpression of CLN1, CLN2, or CLB5, but not CLN3, killed mec1 strains. We identified RNR1, which encodes a subunit of ribonucleotide reductase, as a high-copy suppressor of the lethality of mec1 GAL1-CLN1. Northern analysis demonstrated that RNR1 expression is reduced by CLN1 or CLN2 overexpression. Because limiting RNR1 expression would be expected to decrease dNTP pools, CLN1 and CLN2 may cause lethality in mec1 strains by causing initiation of DNA replication with inadequate dNTPs. In contrast to mec1 mutants, MEC1 strains with low dNTPs would be able to delay S phase and thereby remain viable. We propose that the essential function for MEC1 may be the same as its checkpoint function during hydroxyurea treatment, namely, to slow S phase when nucleotides are limiting. In a cln1 cln2 background, a prolonged period of expression of genes turned on at the G1-S border, such as RNR1, has been observed. Thus deletion of CLN1 and CLN2 could function similarly to overexpression of RNR1 in suppressing mec1 lethality
Modeling a falling slinky
A slinky is an example of a tension spring: in an unstretched state a slinky
is collapsed, with turns touching, and a finite tension is required to separate
the turns from this state. If a slinky is suspended from its top and stretched
under gravity and then released, the bottom of the slinky does not begin to
fall until the top section of the slinky, which collapses turn by turn from the
top, collides with the bottom. The total collapse time t_c (typically ~0.3 s
for real slinkies) corresponds to the time required for a wave front to
propagate down the slinky to communicate the release of the top end. We present
a modification to an existing model for a falling tension spring (Calkin 1993)
and apply it to data from filmed drops of two real slinkies. The modification
of the model is the inclusion of a finite time for collapse of the turns of the
slinky behind the collapse front propagating down the slinky during the fall.
The new finite-collapse time model achieves a good qualitative fit to the
observed positions of the top of the real slinkies during the measured drops.
The spring constant k for each slinky is taken to be a free parameter in the
model. The best-fit model values for k for each slinky are approximately
consistent with values obtained from measured periods of oscillation of the
slinkies.Comment: 30 pages, 11 figure
Providing Basic Needs and Encouragement as Strategies in Managing Aggression in Dementia Clients
Purpose: The experiences of caregivers in managing dementia clients with aggressive behaviour have been an issue in nursing homes. This study utilized the fact that there is no significant strategy for managing aggression effectively. The aim of the study is to explore the experiences of caregivers in managing dementia clients with aggressive behaviour in nursing home in Jakarta, Indonesia.Method: This study employed a hermeneutic phenomenological approach so that caregivers were able to explore the phenomenon of aggression by dementia residents in the nursing home. Six experienced caregivers were interviewed in this study to uncover caregivers\u27 strategies they use in managing aggression in dementia residents.Result: The findings in this study were several strategies that have been used by caregivers to manage aggressive behaviour among dementia residents in the nursing home: providing basic needs and encouragement.Conclusion: The findings suggested caregivers to implement the strategies for managing aggression in dementia residents. Due to a limited number of related studies in Indonesia, this study recommended for further research to other nursing homes in Indonesia to determine if other strategies to manage aggression exist
Dynamics of Coupled Maps with a Conservation Law
A particularly simple model belonging to a wide class of coupled maps which
obey a local conservation law is studied. The phase structure of the system and
the types of the phase transitions are determined. It is argued that the
structure of the phase diagram is robust with respect to mild violations of the
conservation law. Critical exponents possibly determining a new universality
class are calculated for a set of independent order parameters. Numerical
evidence is produced suggesting that the singularity in the density of Lyapunov
exponents at is a reflection of the singularity in the density of
Fourier modes (a ``Van Hove'' singularity) and disappears if the conservation
law is broken. Applicability of the Lyapunov dimension to the description of
spatiotemporal chaos in a system with a conservation law is discussed.Comment: To be published in CHAOS #7 (31 page, 16 figures
Mutations In RAD27 Define A Potential Link Between Gâ Cyclins And DNA Replication
The yeast Saccharomyces cerevisiae has three G1 cyclin (CLN) genes with overlapping functions. To analyze the functions of the various CLN genes, we examined mutations that result in lethality in conjunction with loss of cln1 and cln2. We have isolated alleles of RAD27/ERC11/YKL510, the yeast homolog of the gene encoding flap endonuclease 1, FEN-1.cln1 cln2 rad27/erc11 cells arrest in S phase; this cell cycle arrest is suppressed by the expression of CLN1 or CLN2 but not by that of CLN3 or the hyperactive CLN3-2. rad27/erc11 mutants are also defective in DNA damage repair, as determined by their increased sensitivity to a DNA-damaging agent, increased mitotic recombination rates, and increased spontaneous mutation rates. Unlike the block in cell cycle progression, these phenotypes are not suppressed by CLN1 or CLN2. CLN1 and CLN2 may activate an RAD27/ERC11-independent pathway specific for DNA synthesis that CLN3 is incapable of activating. Alternatively, CLN1 and CLN2 may be capable of overriding a checkpoint response which otherwise causes cln1 cln2 rad27/erc11 cells to arrest. These results imply that CLN1 and CLN2 have a role in the regulation of DNA replication. Consistent with this, GAL-CLN1 expression in checkpoint-deficient, mec1-1 mutant cells results in both cell death and increased chromosome loss among survivors, suggesting that CLN1 overexpression either activates defective DNA replication or leads to insensitivity to DNA damage
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