3,713 research outputs found
Observations of perpetual hyphal propagation in Neurospora crassa
Observations of perpetual hyphal propagation in Neurospora crass
High-temperature environments of human evolution in East Africa based on bond ordering in paleosol carbonates
Many important hominid-bearing fossil localities in East Africa are in regions that are extremely hot and dry. Although humans are well adapted to such conditions, it has been inferred that East African environments were cooler or more wooded during the Pliocene and Pleistocene when this region was a central stage of human evolution. Here we show that the Turkana Basin, Kenyaâtoday one of the hottest places on Earthâhas been continually hot during the past 4 million years. The distribution of ^(13)C-^(18)O bonds in paleosol carbonates indicates that soil temperatures during periods of carbonate formation were typically above 30 °C and often in excess of 35 °C. Similar soil temperatures are observed today in the Turkana Basin and reflect high air temperatures combined with solar heating of the soil surface. These results are specific to periods of soil carbonate formation, and we suggest that such periods composed a large fraction of integrated time in the Turkana Basin. If correct, this interpretation has implications for human thermophysiology and implies a long-standing human association with marginal environments
Semicrompressible Ocean Thermodynamics and Boussinesq Energy Conservation
Equations more accurate than the Boussinesq set that still filter out sound were recently introduced. While these equations were shown to have a consistent potential energy, their thermodynamical behavior and associated implications were not fully analyzed. These shortcomings are remedied in the present note that argues both sets are fully consistent from a thermodynamic perspective. It is further argued that both sets remain computationally competitive with the
Boussinesq set
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An historical perspective on the development of the thermodynamic equation of seawater - 2010
Oceanography is concerned with understanding the mechanisms controlling the movement of seawater and
its contents. A fundamental tool in this process is the characterization of the thermophysical properties of seawater as functions of measured temperature and electrical conductivity, the latter used as a proxy for the concentration of dissolved matter in seawater. For many years a collection of algorithms denoted the Equation of State 1980 (EOS-80) has been the internationally accepted standard for calculating
such properties. However, modern measurement technology
now allows routine observations of temperature and electrical conductivity to be made to at least one order of magnitude more accurately than the uncertainty in this standard. Recently, a new standard has been developed, the Thermodynamical Equation of Seawater 2010 (TEOS-10). This new standard is thermodynamically consistent, valid over a wider range of temperature and salinity, and includes a mechanism to account for composition variations in seawater. Here we review the scientiïŹc development of this standard, and describe the literature involved in its development, which includes many of the articles in this special issue
Boundary effect of a partition in a quantum well
The paper wishes to demonstrate that, in quantum systems with boundaries,
different boundary conditions can lead to remarkably different physical
behaviour. Our seemingly innocent setting is a one dimensional potential well
that is divided into two halves by a thin separating wall. The two half wells
are populated by the same type and number of particles and are kept at the same
temperature. The only difference is in the boundary condition imposed at the
two sides of the separating wall, which is the Dirichlet condition from the
left and the Neumann condition from the right. The resulting different energy
spectra cause a difference in the quantum statistically emerging pressure on
the two sides. The net force acting on the separating wall proves to be nonzero
at any temperature and, after a weak decrease in the low temperature domain, to
increase and diverge with a square-root-of-temperature asymptotics for high
temperatures. These observations hold for both bosonic and fermionic type
particles, but with quantitative differences. We work out several analytic
approximations to explain these differences and the various aspects of the
found unexpectedly complex picture.Comment: LaTeX (with iopart.cls, iopart10.clo and iopart12.clo), 28 pages, 17
figure
Patient choice at the point of GP referral: Department of Health
1 The Department of Health has a Public Service
Agreement target to ensure that by the end of 2005 every
hospital appointment in the National Health Service in
England (the NHS) will be booked for the convenience of
the patient, making it easier for patients and their General
Practitioners (GPs) to choose the hospital and consultant
that best meets their need. The Department aims to
provide patients with the opportunity to choose between
four to five healthcare providers for elective hospital
treatment by December 2005. In consultation with their
GP, patients should be able to choose, from a menu of
NHS and independent sector healthcare providers, their
preferred location for treatment. Patients should also be
able to book the time and date of their initial outpatient
appointment within 24 hours of the decision to refer the
patient for treatment. This target will apply to around
9.4 million patients referred for hospital treatment by their
GP each year, around four per cent of the total estimated
241 million GP consultations.
2 Choice at referral can contribute to a more patientfocused health service, bringing benefits to both patients
and the NHS. But providing such a choice will not happen
by accident. There are a number of dependencies and
interactions with other policies that need to be managed.
Information Technology (IT) systems need to be developed
and modified and significant cultural, organisational and
behavioural changes will need to be made by patients,
NHS organisations and staff.
3 This report examines whether the Department is on
track to deliver choice at the point of referral successfully
by the target date of December 2005. Our work has
found that:
a Progress has been made towards delivering choice
at referral through establishing the required
organisational infrastructure, commissioning new
IT systems and modifications to existing ones, and
providing support for the NHS organisations that will
deliver it.
b The engagement of GPs is currently low and is a key
risk which the Department must address to deliver
choice successfully. The Department plans to
address this risk through a campaign to inform and
engage GPs during 2005 and it will need to monitor
carefully the progress of this campaign.
c Choice at referral will be delivered most efficiently
and effectively through electronic booking (e-booking,
also known as Choose and Book), in which the
Electronic Booking Service, commissioned by the
Departmentâs National Programme for IT (NPfIT),
is linked to upgraded or new computer systems in
hospitals and GPsâ surgeries. However, e-booking
will not be universally available by December 2005.
Until e-booking is fully adopted choice will have to be
provided in other, less efficient, ways.
d Parts of the NHS still have much to do if they
are to deliver choice. A significant minority of
Primary Care Trusts do not yet have adequate plans
in place to manage the introduction of choice and
some may struggle to manage the required new
commissioning arrangements.
4 Our more detailed findings are as follows.
Progress has been made towards
delivering choice at referral
5 The Department believes that choice is affordable.
Additional annual infrastructure and transaction costs
are estimated to be ÂŁ122 million â or 1.4 per cent of the
current total expenditure on elective care. The main aim
of introducing choice is to improve services for patients,
but it should lead to increased efficiencies in primary and
secondary care services worth an estimated ÂŁ71 million,
off-setting some of these costs.
6 It is essential that choice is supported by other
elements of system reform including e-booking, payment
by results, commissioning and appropriate capacity.
Modelling exercises have shown that the system reforms
should work in harmony with one another. Payment by
results should enable the transfer of funding to follow the
patient and there should be sufficient capacity across the
system to enable choice to be effective.
7 Much of the organisational infrastructure that
is required for choice is in place and there is clear
accountability for the delivery of the programme. To
strengthen detailed national programme management
arrangements the Department created, on 22 December
2004, a new post of National Implementation Director
for Choose and Book, with effect from 10 January 2005.
The new Director will be responsible for overseeing the
implementation of choice within the NHS whilst the
National Programme for IT Group Programme Director for
Choose and Book will continue to be responsible for Choose
and Book technology development and deployment, patient
access and Choose and Book contract management.
8 The Department has provided different types of
support to the NHS â for example, ten pilot schemes
have been run to test the policy in practice. It has set up a
system for periodically measuring progress and used this to
establish the position at the end of October 2004, creating
a baseline against which to monitor future progress.
9 Research has identified what information patients
will want to base their choices on, and the Department
is seeking to provide this. While it is unlikely that full
information will be available for December 2005, the
majority of those aspects identified by patients as being
the most important, such as waiting times and basic
access information, will be in place. The Department
plans to increase the information available over time.
The key risk to the delivery of choice
is the engagement of GPs
10 Choice cannot be delivered without support from
GPs but our survey of GPs found that around half of
GPs know very little about it and 61 per cent feel either
very negative or a little negative. GPsâ concerns include
practice capacity, workload, consultation length and fears
that existing health inequalities will be exacerbated. The
Department has deliberately held back its main effort to
inform and engage GPs about choice until it has had a
working e-booking system to show GPs, but it intends to
mount a campaign to inform and engage GPs during 2005.
Until e-booking is fully adopted
choice will be supported by
other mechanisms
11 The Department has commissioned Atos Origin to
develop a national system for e-booking, which will be
linked to upgraded or new Patient Administration Systems
in hospitals and IT systems in GPsâ surgeries to provide
an overall service known as e-booking. The National
Programme for IT has planned the roll out of e-booking on
an incremental basis to minimise risk, and to link it by the
end of 2005 to some 60 to 70 per cent of hospital systems
and GP practices.
12 E-booking is the most effective and efficient way
of delivering the Departmentâs plans for choice, and
alternative booking mechanisms offer poorer value for
money. Atos Origin has delivered a functioning system
and the first booking using e-booking was made in
July 2004. However the roll-out of e-booking has been
slower than planned and at the end of December 2004
only 63 bookings had been made. Problems have
included the reluctance of users to work with an
unreliable end-to-end system, limited progress in linking
to GP and hospital systems, and the limited number of
GPs willing to use the system.
13 The Department believes that new releases of
software have addressed the reliability of the whole
end-to-end system and that having a fully operational
system will encourage GPs to engage with e-booking. The
roll-out of changes to hospital systems to allow them to
link to e-booking is gathering pace and four types of GP
systems can now link to e-booking, although the largest
supplier has not yet agreed an implementation plan. A
combined team of Departmental and NHS personnel
are working with the three main existing GP system
suppliers to agree a national deployment schedule. This
work should be completed by February 2005, along with
a nationally negotiated commercial arrangement. The
Department is also developing and trialling contingency
plans against further delays, as well as alternatives to the
fully integrated Choose and Book solution.
Parts of the NHS still have much to do
14 Programme management arrangements in the NHS
are incomplete. While most Primary Care Trusts expect to
be able to deliver the choice target, there is variability in
their overall performance. As many as a quarter of Primary
Care Trusts currently forecast that they will not deliver the
choice targets. In addition, some Primary Care Trusts may
struggle to manage the new commissioning arrangements
and two-thirds have yet to commission the required number
of providers. The department is developing a framework of
support to assist trusts to overcome these obstacles.
15 The Department needs urgently to address the low
level of GP support for their plans for implementing
choice at referral, and should:
I Press on urgently with its plans for informing GPs
about the implementation of choice at referral and
its impact on GPs and patients.
II Monitor the views of GPs, for example by a regular
survey, repeating key questions from our own survey,
to assess the rate of progress being achieved towards
the level of support needed to meet its target of full
implementation by December 2005.
III Consider whether further action is needed to secure
the required level of GP support, once GPs are fully
informed on what choice at referral involves.
16 The Department should also:
IV Complete its planned benefits realisation plan for
choice at referral by the summer of 2005, along with
a monitoring mechanism and quantified targets.
V Keep under regular and close review the progress
of its planned implementation of choice through
implementing e-booking and consider the scope
for accelerating the roll-out of e-booking to make it
available everywhere by December 2005.
VI If it becomes clear that it is not possible to deliver
e-booking everywhere by December 2005, the
Department should:
a monitor closely the development of the interim
solutions to ensure that they meet their delivery
dates; and
b ensure that the implementation of interim
solutions does not detract from the priority of
bringing in fully integrated e-booking systems
as soon as possible.
VII Establish an evaluation framework for Primary
Care Trust commissioning to assist Strategic Health
Authorities in assessing the capacity and skills
of Primary Care Trusts in this area and securing
improvements in capacity and skills where necessary
The life and work of Nick Fofonoff
Author Posting. © Sears Foundation for Marine Research, 2005. This article is posted here by permission of Sears Foundation for Marine Research for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 63 (2005): 1-7, doi:10.1357/0022240053693824
A global algorithm for estimating Absolute Salinity
The International Thermodynamic Equation of Seawater â 2010 has defined the thermodynamic properties of seawater in terms of a new salinity variable, Absolute Salinity, which takes into account the spatial variation of the composition of seawater. Absolute Salinity more accurately reflects the effects of the dissolved material in seawater on the thermodynamic properties (particularly density) than does Practical Salinity. <br><br> When a seawater sample has standard composition (i.e. the ratios of the constituents of sea salt are the same as those of surface water of the North Atlantic), Practical Salinity can be used to accurately evaluate the thermodynamic properties of seawater. When seawater is not of standard composition, Practical Salinity alone is not sufficient and the Absolute Salinity Anomaly needs to be estimated; this anomaly is as large as 0.025 g kg<sup>â1</sup> in the northernmost North Pacific. Here we provide an algorithm for estimating Absolute Salinity Anomaly for any location (<i>x, y, p</i>) in the world ocean. <br><br> To develop this algorithm, we used the Absolute Salinity Anomaly that is found by comparing the density calculated from Practical Salinity to the density measured in the laboratory. These estimates of Absolute Salinity Anomaly however are limited to the number of available observations (namely 811). In order to provide a practical method that can be used at any location in the world ocean, we take advantage of approximate relationships between Absolute Salinity Anomaly and silicate concentrations (which are available globally)
Benzothiadiazole induces the accumulation of phenolics and improves resistance to powdery mildew in strawberries
Benzothiadiazole (BTH) enhanced the accumulation of soluble and cell-wall-bound phenolics in strawberry leaves and also improved the resistance to powdery mildew infection under greenhouse conditions. The most pronounced change was seen in the levels of ellagitannins, which increased up to 2- to 6-fold 4 days after the BTH application, but persisted only in the inoculated plants. The induction of phenolic metabolism by BTH was also reflected in the fruits, several compounds being increased in inoculated, BTH-treated plants. Basal salicylic acid (SA) content was high in strawberry leaves, but increased in a similar fashion to other phenolics after the treatments. Several phenolic compounds were identified in strawberries for the first time. For example, ellagic acid deoxyhexose, three agrimoniin-like ellagitannins, sanguiin H-10- and lambertianin C-like ellagitannins in the leaves, ellagic acid, p-coumaric acid, gallic acid, and kaempferol hexose in the cell-wall-bound fraction of the leaves, and kaempferol malonylglucoside in the fruits. The findings show that BTH can enhance the accumulation of phenolics in strawberry plants which may then be involved in the BTH-induced resistance to powdery mildew
Many-body Effects in Angle-resolved Photoemission: Quasiparticle Energy and Lifetime of a Mo(110) Surface State
In a high-resolution photoemission study of a Mo(110) surface state various
contributions to the measured width and energy of the quasiparticle peak are
investigated. Electron-phonon coupling, electron-electron interactions and
scattering from defects are all identified mechanisms responsible for the
finite lifetime of a valence photo-hole. The electron-phonon induced mass
enhancement and rapid change of the photo-hole lifetime near the Fermi level
are observed for the first time.Comment: RevTEX, 4 pages, 4 figures, to be published in PR
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