5,156 research outputs found
Do body condition and plumage during fuelling predict northwards departure dates of Great Knots Calidris tenuirostris from north-west Australia?
It is often assumed that strong selection pressures give rise to trade-offs between body condition and time in long-distance migrating birds. Birds that are 'behind schedule' in fuel deposition or moult should delay departure, and this should result in a negative correlation between initial condition and departure date. We tested this hypothesis in the Great Knot Calidris tenuirostris migrating from north-west Australia to eastern Asia en route to Siberia. Great Knot gain mass and moult into breeding plumage before leaving northern Australia in late March and early April, and fly 5400-6000 km to eastern China and Korea. We radiotracked 27 individuals (17 males and ten females) to determine departure dates; 23 migrated and four remained in Australia. We characterized body condition at capture using body mass, predicted pectoral muscle mass (based on ultrasound estimates of the size of the pectoral muscles) and breeding plumage scores. Residual condition indices were uncorrelated, indicating that at the individual level, variation in one fuelling component was not strongly associated with variation in the other components. Birds that did not depart had lower residual body mass and breeding plumage indices than those that did migrate; these four birds may have been subadults. Neither sex, size nor the condition indices explained variation in departure date of migrants. Reasons for this are explored. Departure dates for northward migrating waders indicate that the migration window (span over which birds depart) decreases with proximity to the northern breeding grounds. We suggest that migration schedules become tighter as birds get nearer to the breeding grounds. Thus the lack of a relationship between condition and departure date in Great Knots may reflect the fact that the departure episode under study is the first one in sequence and is still 4-8 weeks before breeding
Searching for wheat resistance to aphids and wheat bulb fly in the historical Watkins and Gediflux wheat collections
Insect pests can reduce wheat yield by direct feeding and transmission of plant
viruses. Here we report results from laboratory and field phenotyping studies
on a wide range of wheat, including landraces from the Watkins collection
deriving from before the green revolution, more modern cultivars from the
Gediflux collection (north-western Europe) and modern UK Elite varieties,
for resistance to the bird cherry-oat aphid, Rhopalosiphum padi (Homoptera:
Aphididae) and the English grain aphid, Sitobion avenae (Homoptera: Aphididae).
A total of 338 lines were screened for R. padi and 340 lines for S. avenae.
Field trials were also conducted on 122 Watkins lines to identify wheat bulb
fly, Delia coarctata, preference on these landraces. Considerable variation was
shown in insect performance among and within different wheat collections,
with reduced susceptibility in a number of varieties, but phenotyping did not
identify strong resistance to aphids or wheat bulb fly. Field trials showed within
collection differences in aphid performance, with fewer aphids populating lines
from the Watkins collection. This differs from development data in laboratory
bioassays and suggests that there is a pre-alighting cue deterring aphid settlement
and demonstrates differences in aphid preference and performance on
older plants in the field compared with seedlings in the laboratory, highlighting
the need for phenotyping for aphid resistance at different plant growth stages.
No association was identified between performance of the different insect
species on individual varieties, potentially suggesting different nutritional
requirements or resistance mechanisms
Hypophosphataemia after intravenous iron therapy with ferric carboxymaltoseâReal world experience from a tertiary centre in the UK
Background:
Iron deficiency is the most common global cause of anaemia. Intravenous (IV) iron is used to correct iron deficiency anaemia (IDA) where oral iron cannot be used. Despite being effective, certain IV iron formulations cause significant hypophosphataemia. However, current knowledge on the clinical consequences of IV ironâinduced hypophosphataemia is broadly anecdotal or limited to isolated case reports.
/
Aims:
To retrospectively examine the incidence and potential clinical consequences of hypophosphataemia postâIV ferric carboxymaltose (FCM) in hospitalised patients with IDA (mixed aetiology). /
Methods:
Data were collected for 162 patients, who received a total of 169 FCM courses during a 2âyear audit period. Outcomes included incidence of moderate/severe hypophosphataemia (serum phosphate <0.65 mmol/L) â€90 days postâFCM, changes in alkaline phosphatase, need for phosphate replacement, and length of hospital stay. /
Results:
The incidence of moderate/severe hypophosphataemia postâFCM was 33.7%; within this group the rate of severe hypophosphataemia (serum phosphate â€0.32 mmol/L) was 8.8%. Moderate/severe hypophosphataemia persisted, with 35% of patients having a serum phosphate of <0.65 mmol/L for â€90 days at the last measurement after IV FCM. Intervention with IV phosphateâan average of 4.4 infusions per personâwas required in 29.8% of cases with moderate/severe hypophosphataemia. FCMâinduced moderate/severe hypophosphataemia was associated with a significantly longer hospital stay (P < 0.0035). /
Conclusions:
Moderate/severe hypophosphataemia is a frequent adverse drug reaction with FCM. In our study, FCMâinduced moderate/severe hypophosphataemia was also persistent, often required treatment, and was associated with longer hospital stay
Enteral Nutrition in Adult Crohnâs Disease: Toward a Paradigm Shift
Medical and surgical treatments for Crohnâs disease are associated with toxic effects. Medical therapy aims for mucosal healing and is achievable with biologics, immunosuppressive therapy, and specialised enteral nutrition, but not with corticosteroids. Sustained remission remains a therapeutic challenge. Enteral nutrition, containing macro- and micro-nutrients, is nutritionally complete, and is provided in powder or liquid form. Enteral nutrition is a low-risk and minimally invasive therapy. It is well-established and recommended as first line induction therapy in paediatric Crohnâs disease with remission rates of up to 80%. Other than in Japan, enteral nutrition is not routinely used in the adult population among Western countries, mainly due to unpalatable formulations which lead to poor compliance. This study aims to offer a comprehensive review of available enteral nutrition formulations and the literature supporting the use and mechanisms of action of enteral nutrition in adult Crohnâs disease patients, in order to support clinicians in real world decision-making when offering/accepting treatment. The mechanisms of actions of enteral feed, including their impact on the gut microbiome, were explored. Barriers to the use of enteral nutrition, such as compliance and the route of administration, were considered. All available enteral preparations have been comprehensively described as a practical guide for clinical use. Likewise, guidelines are reported and discussed
High-Performance Flexible Magnetic Tunnel Junctions for Smart Miniaturized Instruments
Flexible electronics is an emerging field in many applications ranging from
in vivo biomedical devices to wearable smart systems. The capability of
conforming to curved surfaces opens the door to add electronic components to
miniaturized instruments, where size and weight are critical parameters. Given
their prevalence on the sensors market, flexible magnetic sensors play a major
role in this progress. For many high-performance applications, magnetic tunnel
junctions (MTJs) have become the first choice, due to their high sensitivity,
low power consumption etc. MTJs are also promising candidates for non-volatile
next-generation data storage media and, hence, could become central components
of wearable electronic devices. In this work, a generic low-cost regenerative
batch fabrication process is utilized to transform rigid MTJs on a 500 {\mu}m
silicon wafer substrate into 5 {\mu}m thin, mechanically flexible silicon
devices, and ensuring optimal utilization of the whole substrate. This method
maintains the outstanding magnetic properties, which are only obtained by
deposition of the MTJ on smooth high-quality silicon wafers. The flexible MTJs
are highly reliable and resistive to mechanical stress. Bending of the MTJ
stacks with a diameter as small as 500 {\mu}m is possible without compromising
their performance and an endurance of over 1000 cycles without fatigue has been
demonstrated. The flexible MTJs were mounted onto the tip of a cardiac catheter
with 2 mm in diameter without compromising their performance. This enables the
detection of magnetic fields and the angle which they are applied at with a
high sensitivity of 4.93 %/Oe and a low power consumption of 0.15 {\mu}W, while
adding only 8 {\mu}g and 15 {\mu}m to the weight and diameter of the catheter,
respectively.Comment: 20 pages, 6 figures, Intermag 201
Social networks and labour productivity in Europe: An empirical investigation
This paper uses firm-level data recorded in the AMADEUS database to
investigate the distribution of labour productivity in different European
countries. We find that the upper tail of the empirical productivity
distributions follows a decaying power-law, whose exponent is obtained
by a semi-parametric estimation technique recently developed by Clementi et al.
(2006). The emergence of "fat tails" in productivity distribution has already
been detected in Di Matteo et al. (2005) and explained by means of a model of
social network. Here we show that this model is tested on a broader sample of
countries having different patterns of social network structure. These
different social attitudes, measured using a social capital indicator, reflect
in the power-law exponent estimates, verifying in this way the existence of
linkages among firms' productivity performance and social network.Comment: LaTeX2e; 18 pages with 3 figures; Journal of Economic Interaction and
Coordination, in pres
Clinical and Nutritional Care Pathways of Patients with Malignant Bowel Obstruction: A Retrospective Analysis in a Tertiary UK Center
We describe a retrospective cohort study of patients with malignant bowel obstruction to examine their nutritional care pathways between 1.1.16 and 31.12.16 with readmissions until 31.12.17. Data were analyzed by comparing patients who were referred (R) and not referred (NR) for PN. We identified 72 patients with 117 MBO admissions (meanâ±âSD age:63.1â±â13.1yrs, 79% female). 24/72 patients were in R group. Predominant primary malignancies were gynaecological and lower-gastrointestinal cancers (76%). 83% patients had metastases (61% sub-diaphragmatically). All patients were at high-risk of malnutrition and baseline mean weight loss was 7%. Discussion of PN at multidisciplinary team meeting (MDT) (22% vs.5%, Pâ=â0.02) and dietetic contact (94% vs. 41%, Pâ<â0.0001) were more likely to occur in the R group. In 13/69 MBO admissions in NR group, reasons for non-referral were unclear. Median baseline and follow-up weight was similar (55â55.8âkg). Overall survival was 4.7 (1.4â15.2)months, with no differences by referral groups. We compared a sub-sample of patients who âmay haveâ required PN (nâ=â10) vs. those discharged on home PN (nâ=â10) and found greater survival in the HPN group (323vs.91âday, Pâ<â0.01). Our findings highlight disparity in care pathways suggesting that nutritional care should be integrated into clinical management discussion(s) at MDT to ensure equal access to nutritional services
On the Nature of Small Planets around the Coolest Kepler Stars
We constrain the densities of Earth- to Neptune-size planets around very cool
(Te =3660-4660K) Kepler stars by comparing 1202 Keck/HIRES radial velocity
measurements of 150 nearby stars to a model based on Kepler candidate planet
radii and a power-law mass-radius relation. Our analysis is based on the
presumption that the planet populations around the two sets of stars are the
same. The model can reproduce the observed distribution of radial velocity
variation over a range of parameter values, but, for the expected level of
Doppler systematic error, the highest Kolmogorov-Smirnov probabilities occur
for a power-law index alpha ~ 4, indicating that rocky-metal planets dominate
the planet population in this size range. A single population of gas-rich,
low-density planets with alpha = 2 is ruled out unless our Doppler errors are
>= 5m/s, i.e., much larger than expected based on observations and stellar
chromospheric emission. If small planets are a mix of gamma rocky planets
(alpha = 3.85) and 1-gamma gas-rich planets (alpha = 2), then gamma > 0.5
unless Doppler errors are >=4 m/s. Our comparison also suggests that Kepler's
detection efficiency relative to ideal calculations is less than unity. One
possible source of incompleteness is target stars that are misclassified
subgiants or giants, for which the transits of small planets would be
impossible to detect. Our results are robust to systematic effects, and
plausible errors in the estimated radii of Kepler stars have only moderate
impact.Comment: Accepted to the Astrophysical Journa
Fermionic counting of RSOS-states and Virasoro character formulas for the unitary minimal series M(\nu,\nu+1). Exact results
The Hilbert space of an RSOS-model, introduced by Andrews, Baxter, and
Forrester, can be viewed as a space of sequences (paths) {a_0,a_1,...,a_L},
with a_j-integers restricted by 1<=a_j<=\nu, |a_j-a_{j+1}|=1, a_0=s, a_L=r. In
this paper we introduce different basis which, as shown here, has the same
dimension as that of an RSOS-model. Following McCoy et al, we call this basis
-- fermionic (FB). Our first theorem Dim(FB)=Dim(RSOS-basis) can be succinctly
expressed in terms of some identities for binomial coefficients. Remarkably,
these binomial identities can be q-deformed. Here, we give a simple proof of
these q-binomial identities in the spirit of Schur's proof of the
Rogers-Ramanujan identities. Notably, the proof involves only the elementary
recurrences for the q-binomial coefficients and a few creative observations.
Finally, taking the limit L --> \infty in these q-identities, we derive an
expression for the character formulas of the unitary minimal series
M(\nu,\nu+1) "Bosonic Sum = Fermionic Sum". Here, Bosonic Sum denotes
Rocha-Caridi representation (\chi_{r,s=1}^{\nu,\nu+1}(q)) and Fermionic Sum
stands for the companion representation recently conjectured by the Stony Brook
group.Comment: 33pp, LaTex, BONN-HE-94-04, spelling errors and typos corrected,
references added, to appear in Nucl. Phys. B431 (1994
Foreground Contamination in Interferometric Measurements of the Redshifted 21 cm Power Spectrum
Subtraction of astrophysical foreground contamination from "dirty" sky maps
produced by simulated measurements of the Murchison Widefield Array (MWA) has
been performed by fitting a 3rd-order polynomial along the spectral dimension
of each pixel in the data cubes. The simulations are the first to include the
unavoidable instrumental effects of the frequency-dependent primary antenna
beams and synthesized array beams. They recover the one-dimensional
spherically-binned input redshifted 21 cm power spectrum to within
approximately 1% over the scales probed most sensitively by the MWA (0.01 < k <
1 Mpc^-1) and demonstrate that realistic instrumental effects will not mask the
EoR signal. We find that the weighting function used to produce the dirty sky
maps from the gridded visibility measurements is important to the success of
the technique. Uniform weighting of the visibility measurements produces the
best results, whereas natural weighting significantly worsens the foreground
subtraction by coupling structure in the density of the visibility measurements
to spectral structure in the dirty sky map data cube. The extremely dense
uv-coverage of the MWA was found to be advantageous for this technique and
produced very good results on scales corresponding to |u| < 500 wavelengths in
the uv-plane without any selective editing of the uv-coverage.Comment: Replaced with version accepted by ApJ. 19 pages, including 3 figure
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