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A variety of paediatric tracheostomy tubes are available. This article reviews the tubes in current use at Great Ormond Street Hospital for Children and Evelina London Children's Hospital.
This paper outlines our current preferences, and the particular indications for different tracheostomy tubes, speaking valves and other attachments.
Our preferred types of tubes have undergone significant design changes. This paper also reports further experience with certain tubes that may be useful in particular circumstances. An updated sizing chart is included for reference purposes.
The choice of a paediatric tracheostomy tube remains largely determined by individual clinical requirements. Although we still favour a small range of tubes for use in the majority of our patients, there are circumstances in which other varieties are indicated.
Excitable temperament disrupts physiological events required for reproductive development in cattle, but no research has investigated the impacts of temperament on growth and puberty attainment in Bos indicus females. Hence, this experiment evaluated the effects of temperament on growth, plasma cortisol concentrations and puberty attainment in B. indicus heifers. A total of 170 Nelore heifers, weaned 4 months before the beginning of this experiment (days 0 to 91), were managed in two groups of 82 and 88 heifers each (mean ± SE; initial BW=238±2 kg, initial age=369±1 days across groups). Heifer temperament was evaluated via exit velocity on day 0. Individual exit score was calculated within each group by dividing exit velocity into quintiles and assigning heifers with a score from 1 to 5 (1=slowest; 5=fastest heifer). Heifers were classified according to exit score as adequate (ADQ, n=96; exit score⩽3) or excitable temperament (EXC, n=74; exit score>3). Heifer BW, body condition score (BCS) and blood samples were obtained on days 0, 31, 60 and 91. Heifer exit velocity and score were recorded again on days 31, 60 and 91. Ovarian transrectal ultrasonography was performed on days 0 and 10, 31 and 41, 60 and 70, 81 and 91 for puberty evaluation. Heifer was declared pubertal at the first 10-day interval in which a corpus luteum was detected. Exit velocity and exit score obtained on day 0 were correlated (r⩾0.64, P<0.01) with evaluations on days 31, 60 and 91. During the experiment, ADQ had greater (P<0.01) mean BCS and BW gain, and less (P<0.01) mean plasma cortisol concentration compared with EXC heifers. Temperament × time interactions were detected (P<0.01) for exit velocity and exit score, which were always greater (P<0.01) in EXC v. ADQ heifers. A temperament × time interaction was also detected (P=0.03) for puberty attainment, which was delayed in EXC v. ADQ heifers. At the end of the experiment, a greater (P<0.01) proportion of ADQ were pubertal compared with EXC heifers. In summary, B. indicus heifers classified as EXC had reduced growth, increased plasma cortisol concentrations and hindered puberty attainment compared to ADQ heifers. Moreover, exit velocity may serve as temperament selection criteria to optimize development of B. indicus replacement heifers.
Artificial rearing of young animals represents a challenge in modern ruminant production systems. This work aims to evaluate the short- and long-term effects of the type of rearing on the animal’s health, growth, feed utilization and carcass performance. A total of 24 pregnant ewes carrying triplets were used. Within each triplet set, lambs were randomly allocated to one experimental treatment: natural rearing on the ewe (NN); ewe colostrum for 24 h followed by artificial rearing with milk replacer (NA) and 50 g of colostrum alternative supplementation followed by artificial rearing (AA). Milk replacer, ryegrass hay and creep feed were offered ad libitum, and each experimental group was kept in independent pens until weaning at 45 days of age. After weaning all lambs were placed together on the same pasture for fattening for 4 months. Blood samples were taken at 24 h after birth, at weaning and at the end of the fattening period (23 weeks). Results showed that no failure in the passive immune transfer was detected across treatments. Although artificially reared lambs at weaning had lower plasma levels of β-hydroxy-butyrate (−62%), high-density lipoproteins (−13%) and amylase (−25%), and higher levels of low-density lipoproteins (+38%) and alkaline phosphatase (+30%), these differences disappeared during the fattening period. Only the greater levels of calcium and the lower levels of haemoglobin and white blood cells detected at weaning in artificially reared lambs (+7.2%, −2.8% and −17.8%) persisted by the end of the fattening period (+4.3%, −3.3% and −9.5%, respectively). Minor diarrheal events from weeks 2 to 5 were recorded with artificial rearing, leading to lower growth rates during the 1st month. However, these artificially reared lambs caught up towards the end of the milk feeding period and reached similar weaning weights to NN lambs. During the fattening period NN lambs had a greater growth rate (+16%) possibly as a result of their greater early rumen development, which allowed a higher feed digestibility during the fattening period in comparison to NA lambs (+5.9%). As a result, NN lambs had heavier final BWs (+7.0%), but tended to have lower dressing percentage (−5.7%) than artificially reared lambs, thus no differences were noted in either carcass weight or in carcass conformation across treatments. In conclusion, the use of a colostrum alternative and milk replacer facilitated the successful rearing of lambs, reaching similar productive parameters; however, special care must be taken to maximize the rumen development before weaning.
Antibodies at gastrointestinal mucosal membranes play a vital role in immunological protection against a range of pathogens, including helminths. Gastrointestinal health is central to efficient livestock production, and such infections cause significant losses. Fecal samples were taken from 114 cattle, across three beef farms, with matched blood samples taken from 22 of those animals. To achieve fecal antibody detection, a novel fecal supernatant was extracted. Fecal supernatant and serum samples were then analysed, using adapted enzyme-linked immunosorbent assay protocols, for levels of total immunoglobulin (Ig)A, IgG, IgM, and Teladorsagia circumcincta-specific IgA, IgG, IgM and IgE (in the absence of reagents for cattle-specific nematode species). Fecal nematode egg counts were conducted on all fecal samples. Assays performed successfully and showed that IgA was the predominant antibody in fecal samples, whereas IgG was predominant in serum. Total IgA in feces and serum correlated within individuals (0.581, P = 0.005), but other Ig types did not. Results support the hypothesis that the tested protocols are an effective method for the non-invasive assessment of cattle immunology. The method could be used as part of animal health assessments, although further work is required to interpret the relationship between results and levels of infection and immunity.
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.
In this paper, first results comparing modified Longin and ninhydrin collagen extraction methodologies are presented. The goal of this study is to investigate the bones of several species with different ages, preservation conditions, and collagen contents to determine the most suitable preparation method. Different types of samples are used such as VIRI samples, previously dated bones, and background samples. Each bone has undergone elemental analysis, infrared analysis, and 14C measurement. The results are presented and the advantages and disadvantages of each preparation method are discussed. In general, results obtained by the two methods are in accordance with the consensus value for 2σ uncertainty. For VIRI I and a mammoth bone, the ninhydrin preparation gives, respectively, 8450±70 BP and 14,870±60 BP whereas the modified Longin process gives 8365±45 BP and 14,750±100 BP in agreement with the expected values. From the experimental point of view, the modified Longin process is easier to implement than the ninhydrin protocol. From this approach, we can conclude that the modified Longin process could be preferred in most cases and particularly when the amount of bone is small and the sample is not too contaminated.
Sheep can use spatial memory to locate preferred food items in a background of less preferred items and forage more efficiently if the preferred patches are aggregated (Edwards et al. 1994). However, if a constant proportion of available patches contain food, foraging efficiency is not affected by the total number of patches (Edwards et al. 1996). The objective of this study was to test the hypothesis that spatial memory will be used to a lesser extent as the proportion of patches containing food increases. Not only is the animal faced with a potentially more complex task as the proportion of food patches increases but the cost:benefit ratio of using spatial memory is less. If 10 of 100 potential foraging sites contain food, an animal with perfect spatial memory could locate 5 of these patches in only 5 visits, whereas random searching requires 50 visits. If 50 patches contain food, 5 visits are required with perfect spatial memory but only 10 visits using random searching. Thus the benefit of using spatial memory over random search is reduced from 5:1 to 2:1.
TAOS II is a next-generation occultation survey with the goal of measuring the size distribution of the small end of the Kuiper Belt (objects with diameters 0.5–30 km). Such objects have magnitudes r > 30, and are thus undetectable by direct imaging. The project will operate three telescopes at San Pedro Mártir Observatory in Baja California, México. Each telescope will be equipped with a custom-built camera comprised of a focal-plane array of CMOS imagers. The cameras will be capable of reading out image data from 10,000 stars at a cadence of 20 Hz. The telescopes will monitor the same set of stars simultaneously to search for coincident occultation detections, thus minimising the false-positive rate. This talk described the project, and reported on the progress of the development of the survey infrastructure.
We explore the properties of sound and human sound recognition as a means to enhance and accelerate visual-only data analysis methods. The aim of this work is to enable and improve the analysis of large data sets, data requiring rapid analysis, multi-dimensional data, and signal detection in data with low signal-to-noise ratio. We present a prototype tool, StarSound, to sonify data such as astronomical transient light curves, spectra, and power spectra. Stereophonic sound is used to ‘visualise’ and localise the data under examination, and 3-D sound is discussed in conjunction with virtual reality technology, as a means to enhance analysis efficiency and efficacy, including rapid data assessment and training machine learning software. In addition, we explore the use of higher-order harmonics as a means to examine simultaneously multi-dimensional data sets. Such an approach can allow the data to be interpreted in a holistic manner and facilitates the discovery of previously unseen connections and relationships. Furthermore, we exploit the capability of the human brain for selective or focused hearing that enables the identification of desired signals in noisy data, or amidst similar or more significant signals. Finally, we provide research examples that benefit directly from data sonification. The work presented here aims to help tackle the challenges of the upcoming era of Big Data and help optimise, speed up and expand aspects of data analysis requiring human interaction.
The Deeper Wider Faster programme (DWF) is a project that coordinates more than 30 multi-wavelength and multi-messenger facilities worldwide and in space, in order to detect and study fast transients (durations of milliseconds to hours). DWF has four main components: (1) simultaneous observations, where ∼10 major facilities, from radio to gamma-ray, are coordinated to perform short-cadence, deep, wide-field observations of the same field at the same time. Radio telescopes search for fast radio bursts, while optical imagers and high-energy instruments search for transient events whose time-scales are seconds to hours, (2) supercomputer data processing and candidate identification in real time (seconds to minutes), along with human inspection of candidates, also in real time (minutes), using sophisticated visualisation technology, (3) rapid-response (minutes) follow-up spectroscopy and imaging, and conventional ToO observations, and (4) long-term follow up by a global network of 1-m to 4-m telescopes. The principal goals of DWF are to discover and study counterparts to fast radio bursts and gravitational-wave events, as well as transients at all wavelengths that have durations of milliseconds to hours.
Microbially mediated carbon fluxes on the surface of the Greenland ice sheet (GrIS) were recently quantified by Hodson and others (2010) using measurements of the surface coverage of debris (cryoconite) and rates of biological production associated with debris near the ice-sheet margin. We present updated models that do not assume the same spatial uniformity in key parameters employed by Hodson and others (2010) because they make use of biomass distribution and biological production data from a 79 km transect of the GrIS. Further, the models presented here also include for the first time biomass associated with both cryoconite holes and surficial algae. The predicted annual carbon flux for a small (1600 km2) section of ice surrounding the field transect is about four times that estimated using spatially uniform biomass and production in this area. When surficial algae are included, the model predicts about 11 times more carbon fixation via photosynthesis per year than the cryoconite-only models. We therefore suggest that supraglacial carbon fluxes from the GrIS have previously been underestimated by more than an order of magnitude and that the hitherto overlooked surficial algal ecosystem can be the most crucial contributor. The GrIS is shown to be in a relatively stable state of net autotrophy according to our model and so a strong link between bare-ice area and total carbon fluxes is evident. The implication is a biomass feedback to surface albedo and enhanced ablation as a result. Climate predictions for the year 2100 show that greater carbon fixation could also result from climate warming.
The contribution to sea level to 2200 from the grounded, mainland Antarctic Peninsula ice sheet (APIS) was calculated using an ice-sheet model initialized with a new technique computing ice fluxes based on observed surface velocities, altimetry and surface mass balance, and computing volume response using a linearized method. Volume change estimates of the APIS resulting from surface mass-balance anomalies calculated by the regional model RACMO2, forced by A1B and E1 scenarios of the global models ECHAM5 and HadCM3, predicted net negative sea-level contributions between −0.5 and −12 mm sea-level equivalent (SLE) by 2200. Increased glacier flow due to ice thickening returned ∼15% of the increased accumulation to the sea by 2100 and ∼30% by 2200. The likely change in volume of the APIS by 2200 in response to imposed 10 and 20 km retreats of the grounding line at individual large outlet glaciers in Palmer Land, southern Antarctic Peninsula, ranged between 0.5 and 3.5 mm SLE per drainage basin. Ensemble calculations of APIS volume change resulting from imposed grounding-line retreat due to ice-shelf break-up scenarios applied to all 20 of the largest drainage basins in Palmer Land (covering ∼40% of the total area of APIS) resulted in net sea-level contributions of 7–16 mm SLE by 2100, and 10–25 mm SLE by 2200. Inclusion of basins in the northern peninsula and realistic simulation of grounding-line movement for AP outlet glaciers will improve future projections.
Terrestrial gastropods are problematical for radiocarbon (14C) measurement because they tend to incorporate carbon from ancient sources as a result of their dietary behavior. The 14C ecology of the pulmonate land snail, Helix melanostoma in Cyrenaica, northeastern Libya, was investigated as part of a wider study on the potential of using terrestrial mollusk shell for 14C dating of archaeological deposits. H. melanostoma was selected out of the species available in the region as it has the most predictable 14C ecology and also had a ubiquitous presence within the local archaeology. The ecological observations indicate that H. melanostoma has a very homogenous 14C ecology with consistent variations in F14C across sample sites controlled by availability of dietary vegetation. The majority of dated specimens from non-urbanized sample locations have only a small old-carbon effect, weighted mean of 476±48 14C yr, with between ~1% and 9% of dietary F14C from non-organic carbonate sources. Observed instabilities in the 14C ecology can all be attributed to the results of intense human activity not present before the Roman Period. Therefore, H. melanostoma and species with similar ecological behavior are suitable for 14C dating of archaeological and geological deposits with the use of a suitable offset.
Dementia is a neurodegenerative syndrome that interferes with multiple aspects of life, including cognition, daily functioning, and behavior. Despite the large heterogeneity in symptom development, these three domains are seldom studied simultaneously. This study investigates how trajectories of these domains are interrelated within individuals over time, and how they in turn are related to dementia severity and quality of life (QoL).
We used data from a longitudinal clinical cohort study, including 331 dementia patients. Cognitive status was measured using the Mini-Mental State Examination, daily functioning was measured with the disability assessment for dementia and neuropsychiatric symptoms (NPS) were scored using the neuropsychiatric inventory. We investigated the relationships in the time course of the various dementia domains using random effects multilevel models and parallel-process growth models.
Changes in cognition and daily functioning were highly correlated over time (r = 0.85, p < 0.01), as were changes in NPS and functioning (r = −0.60, p < 0.01), while changes in cognition and NPS were not (r = −0.20, p = 0.06). All three domains were strongly associated with dementia severity over time (p < 0.01). Decreased functioning and increased NPS were both associated with decreased QoL (β = 2.97, p < 0.01 and β = −2.41, p < 0.01, respectively), while cognition was not (β = 0.01, p = 0.93).
This study demonstrates the heterogeneity of dementia progression between individuals and between different dementia domains within individuals. To improve our understanding of dementia progression, future research should embrace a broader perspective encompassing multiple outcome measures along with the patient's profile, including neurological factors as well as physical, social, and psychiatric health.
‘Punch-card equipment is becoming more and more a convenient and useful tool of the actuary. For this reason, the study of, this equipment and its flexibility should and will occupy a larger place in the training of actuarial students in the future.’
R. J. WALKER, F.A.S.
The actuary employed in life office work is very closely concerned with the methods by which the valuation and other records of a life office are built up. It is surprising, therefore, that there are very few references in the pages of the Journal of the Institute to the use of punched-card equipment for life office work. The use of the equipment for calculations of interest to the actuary, such as the construction of tables, has also been largely ignored. Actuaries employed in work outside life oflices so often rely on punched-card equipment for their statistical data that the authors feel that no apology is needed to either class of actuary for presenting a paper on the subject. Punchedcard equipment has received much more attention in the Transactions of the Actuarial Society of America, most recent volumes containing a paper or note on its application.
The paper is compares the chronology of the monuments of the Scythian epoch located in the east and west of the Eurasian steppe zone on the basis of both archaeological and radiocarbon data. The lists of 14C dates for the monuments located in different parts of Eurasia are presented according to the periods of their existence. Generally, the 14C dates are confirmed the archaeological point of view and allow us to compare the chronological position of the European and Asian Scythian monuments on the united 14C time scale.
For more than 15 years, the radiocarbon community has participated in a series of laboratory intercomparisons in response to the issue of comparability of measurements as perceived within the wider user communities (Scott et al. 1990; Rozanski et al. 1992; Gulliksen and Scott 1995; Scott et al. 1997). In this report, we provide an update on the current 14C laboratory intercomparison and reflect on future issues linked to the laboratory intercomparison program, not least those resulting from a significant growth in the number of accelerator mass spectrometry (AMS) facilities providing routine dating of small samples (milligram size).
This paper focuses on the chronological study of 2 Scythian period monuments that are the key to the chronology of the entire Eurasian Scythian culture. These are the unique monuments of Arzhan-1 and Arzhan-2 in Central Asia (Tuva Republic). The dating of both these monuments began immediately after their discovery, but discussion about their chronological position is still current. Both monuments contained considerable wooden material from their construction suitable for dendrochronology and radiocarbon dating. The first results for the Arzhan-1 barrow were obtained by wiggle-matching in 2004–2005, while the Arzhan-2 barrow was first dated in 2003. It is now possible to compare the chronological position of these barrows using the same methods. As postulated earlier, Arzhan-1 is the oldest Scythian period monument and is dated to the boundary of the 8–9th centuries BC. The position of the Arzhan-2 monument stretches to the middle of the 7th century BC. δ13C values for annual tree rings in logs from both barrows were also determined to gain a better understanding of the climatic conditions at the time of barrow construction.
Lake Mývatn is an interior highland lake in northern Iceland that forms a unique ecosystem of international scientific importance and is surrounded by a landscape rich in archaeological and paleoenvironmental sites. A significant freshwater reservoir effect (FRE) has been identified in carbon from the lake at some Viking (about AD 870–1000) archaeological sites in the wider region (Mývatnssveit). Previous accelerator mass spectrometry (AMS) measurements indicated this FRE was about 1500–1900 14C yr. Here, we present the results of a study using stable isotope and 14C measurements to quantify the Mývatn FRE for both the Viking and modern periods. This work has identified a temporally variable FRE that is greatly in excess of previous assessments. New, paired samples of contemporaneous bone from terrestrial herbivores and omnivores (including humans) from Viking sites demonstrate at least some omnivore diets incorporated sufficient freshwater resources to result in a herbivore-omnivore age offset of up to 400 14C yr. Modern samples of benthic detritus, aquatic plants, zooplankton, invertebrates, and freshwater fish indicate an FRE in excess of 5000 14C yr in some species. Likely geothermal mechanisms for this large FRE are discussed, along with implications for both chronological reconstruction and integrated investigation of stable and radioactive isotopes.