To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.
This chapter reviews the systematics of partial melting of mantle lithologies – like peridotite and eclogite – in the presence of carbon dioxide. It discusses the composition of mantle-derived magmas generated in the presence of carbon dioxide and whether magmas erupted on Earth’s surface resemble carbonated magmas from the mantle. It reviews how the production of carbon dioxide-rich magma in the mantle varies as a function of tectonic settings – beneath continents and oceans and in subduction zones – and time.
The Fontan procedure is the final stage of surgical palliation for a single-ventricle circulation. Significant complications are common including rhythm disturbance necessitating implantation of a permanent pacemaker. This has been widely considered a negative prognostic indicator.
This single-centre, retrospective case control study involved all patients who underwent the Fontan procedure at the Leeds Congenital Heart Unit between 1990 and 2015 and have had regular follow-up in Yorkshire and Humber, United Kingdom. 167 Fontan patients were identified of which 2 were excluded for having a pre-procedure pacemaker. Of the remainder, 23 patients required a pacemaker. Outcomes were survival, early and late complications, need for further intervention and oxygen saturation in long-term follow-up.
There was no difference in survival (30-day survival pacemaker 92.6%, sinus rhythm 90.5%, p = 0.66, 1-year pacemaker 11.1%, sinus rhythm 10.1%, p = 1). The pacemaker group was more likely to have cerebral or renal complications in the first-year post-procedure (acute kidney injury: sinus rhythm 0.8%, pacemaker 19.1%, p = 0.002). No difference was observed in longer term complications including protein losing enteropathy (sinus rhythm 3.5%, pacemaker 0% p = 1). There was no difference in saturations between the two groups at follow-up. Paced patients were more likely to have required further intervention, with a higher incidence of cardiopulmonary bypass procedures (sinus rhythm 6.3%, pacemaker 35%, p < 0.001).
Despite an increase in early complications and the need for further interventions, pacemaker requirement does not appear to affect long-term survival following the Fontan procedure.
The coaxial compound helicopter with lift-offset rotors has been proposed as a concept for future high-performance rotorcraft. This helicopter usually utilizes a variable-speed rotor system to improve the high-speed performance and the cruise efficiency. A flight dynamics model of this helicopter associated with rotor speed governor/engine model is used in this article to investigate the effect of the rotor speed change and to study the variable rotor speed strategy. Firstly, the power-required results at various rotor rotational speeds are calculated. This comparison indicates that choice of rotor speed can reduce the power consumption, and the rotor speed has to be reduced in high-speed flight due to the compressibility effects at the blade tip region. Furthermore, the rotor speed strategy in trim is obtained by optimizing the power required. It is demonstrated that the variable rotor speed successfully improves the performance across the flight range, but especially in the mid-speed range, where the rotor speed strategy can reduce the overall power consumption by around 15%. To investigate the impact of the rotor speed strategy on the flight dynamics properties, the trim characteristics, the bandwidth and phase delay, and eigenvalues are investigated. It is shown that the reduction of the rotor speed alters the flight dynamics characteristics as it affects the stability, damping, and control power provided by the coaxial rotor. However, the handling qualities requirements are still satisfied with different rotor speed strategies. Finally, a rotor speed strategy associated with the collective pitch is designed for maneuvering flight considering the normal load factor. Inverse simulation is used to investigate this strategy on maneuverability in the Push-up & Pull-over Mission-Task-Element (MTE). It is shown that the helicopter can achieve Level 1 ratings with this rotor speed strategy. In addition, the rotor speed strategy could further reduce the power consumption and pilot workload during the maneuver.
The structure of ThPd4 has been determined by X-ray powder methods. It has the simple cubic Cu3Au (LI2) structure a = 4.110 ± 0.002 Å at 80 at. % palladium. Interatomic distances and the range of stability of this compound and of ThPd3 are discussed briefly.
This study examined the effectiveness of a formal postdoctoral education program designed to teach skills in clinical and translational science, using scholar publication rates as a measure of research productivity.
Participants included 70 clinical fellows who were admitted to a master’s or certificate training program in clinical and translational science from 1999 to 2015 and 70 matched control peers. The primary outcomes were the number of publications 5 years post-fellowship matriculation and time to publishing 15 peer-reviewed manuscripts post-matriculation.
Clinical and translational science program graduates published significantly more peer-reviewed manuscripts at 5 years post-matriculation (median 8 vs 5, p=0.041) and had a faster time to publication of 15 peer-reviewed manuscripts (matched hazard ratio = 2.91, p=0.002). Additionally, program graduates’ publications yielded a significantly higher average H-index (11 vs. 7, p=0.013).
These findings support the effectiveness of formal training programs in clinical and translational science by increasing academic productivity.
Attempts to improve the productivity of farm animals in developing countries have often been thwarted by the inappropriateness of the technologies to the conditions in the recipient countries. The reasons for the successes and failures are numerous, among them the degree of participation of the client farmers testing technologies, government policy, the strengths of the extension service and the prices of inputs and outputs. A study was conducted between 1990 and 1995 in Iraq, Jordan and Syria that aimed to assess the potential for adoption of a number of technologies which were known to improve sheep productivity. The technologies were tested at the farm level under the supervision of researchers in the three national programs.
Historical records are valuable for assessing glacier change in the Canadian High Arctic. Ommanney’s (1969) detailed inventory of Axel Heiberg Island glaciers, based on photography from 1958–59, has been revisited, converted into digital format and compared to glacier extents mapped from 1999–2000 satellite imagery. Our results show that the island-wide ice coverage decreased by 15.92 km2 in the 42 year period, a loss of <1%. However, two trends are apparent: one of advance or minor retreat from basins hosting outlet glaciers from Müller and Steacie Ice Caps, and one of significant retreat, on the order of 50–80%, for independent ice masses, which include valley glaciers, mountain glaciers, glacierets, and ice caps smaller than 25 km2. If the contributions to ice advance of only three surging glaciers are removed, then the island-wide ice loss approaches 60 km2. Furthermore, it is notable that 90% of ice masses smaller than 0.2 km2 disappeared entirely during the 42 year study period, an observation confirmed by field studies. Successful predictions from the original inventory are highlighted and the likely mechanisms driving the observed advances and retreats are discussed.
We present broad band photometry (B and R) of the classic shell galaxy NGC 474. Preliminary results indicate that the shells have a similar colour to and follow the same trend of colour with radius as the underlying galaxy.
We here present a short report about the application of a simple time delay estimator to the extensive data set compiled and partly observed by R. Schild, containing 707 A and B observations with corresponding error estimates from JD 244194 to JD 249169.
We question Newton’s inverse square law of universal gravitation in the light of recent, alternative formulations. In addition, we present numerical simulations of galaxy interactions which were used in an attempt to distinguish between an inverse square law and an inverse linear law. We conclude that an inverse linear relation is as compatible with the observational data on interacting galaxy systems as the inverse square law.
We discuss new evidence which supports the existence of thick disks in elliptical/S0 galaxies. Numerical simulations of weak interactions with thick disk systems produce shell structures very similar in appearance to those observed in many shell galaxies. We think this model presents a more plausible explanation for the formation of shell structures in elliptical/S0 galaxies than does the merger model and, if correct, supports the existence of thick disks in elliptical/S0 galaxies.
Pollack et al. [Icarus 19, 372 (1973)] have reported the optical constants for obsidian, basalt, andesite and basaltic glass over the wavelength range 0.2 to 50 μm, and Lamy [Icarus 34, 68 (1978)] reported the optical constants from 0.10 to 0.44 μ for obsidian, basalt, and basaltic glass. We have revised the former measurements for basaltic glass and extended them into the extreme UV to 0.0173 μ.
Almost twenty years ago, one of our distinguished scientific colleagues, the late Jacob Bronowski, orchestrated a litany of remarks by other mathematicians and physicists to the effect that no system of theoretical constructs dealing with the universe, or indeed any conceivable set of prescriptive algorithms, could ever define their subject in its totality. In this century we have become uncomfortably aware of the extent to which the act of observation, the fact of our singling out some particular phenomenon for study and interpretation, itself affects the outcome of those observations. Even in striving to objectify ourselves, and in the very process of objectification, we still subjectivize the external world by touching it with the fingers of inquiry.
Despite documented associations between stunting and cognitive development, few population-level studies have measured both indicators in individual children or assessed stunting’s associations with other developmental domains.
Meta-analysis using publicly available data from fifteen Multiple Indicator Cluster Surveys (MICS-4) to assess the association between stunting and development, controlling for maternal education, family wealth, books in the home, developmentally supportive parenting and sex of the child, stratified by country prevalence of breast-feeding (‘low BF’<90 %, ‘high BF’ ≥90 %). Ten-item Early Childhood Development Index (ECDI) scores assessed physical, learning, literacy/numeracy and socio-emotional developmental domains. Children on track in three or four domains were considered ‘on-track’ overall.
Fifteen low- and middle-income countries.
Publically available data from 58 513 children aged 36–59 months.
Severe stunting (height-for-age Z-score <−3) was negatively associated with on-track development (OR=0·75; 95 % CI 0·67, 0·83). Any stunting (Z-score <−2) was negatively associated with on-track development in countries with high BF prevalence (OR=0·82; 95 % CI 0·75, 0·89). Severe and any stunting were negatively associated with physical development (OR=0·77; 95 % CI 0·66, 0·89 and OR=0·82; 95 % CI 0·74, 0·91, respectively) and literacy/numeracy development in high BF countries (OR=0·45; 95 % CI 0·38, 0·53 and OR=0·59, 95 % CI 0·51, 0·68, respectively), but not low BF countries (OR=0·93; 95 % CI 0·70, 1·23 and OR=0·95, 95 % CI 0·79, 1·12, respectively). Any stunting was negatively associated with learning (OR=0·79; 95 % CI 0·72, 0·88). There was no clear association between stunting and socio-emotional development.
Stunting is associated with many but not all developmental domains across a diversity of countries and cultures. However, associations varied by country breast-feeding prevalence and developmental domain.
The temperature, surface gravity, and abundances derived for this halo B star by Danziger and Jura (1970, Ap.J., 161, 997) show that it is a field suprahorizontal branch star very similar to B29 in M13. The only difference is that HD137569 has a higher (solar) C abundance. We find that HD137569 is a spectroscopic binary with P=529.8(2) days, Vo=45.0(2) km/s, K=16.2(3) km/s, e=0.12(2), ω=233°(10), and T=JD2441922(14). The parenthesized quantities are the uncertainties (probable errors) of the last digits of the elements.
Nearly eighty years ago W. M. Lindsay began his valuable little Introduction to Latin Textual Emendation with the observation that ‘There is no Latin author the study of whose text has at once such interest and such value for students of textual emendation as Plautus. For the text of Plautus is on the one hand not nearly so certain as the text of Virgil …, nor on the other so hopelessly uncertain as the text of Propertius … It is still full of difficulties, in spite of the labours of a large number of scholars for a large number of years, though each month … sees a difficulty removed … We may hope to attain before long to a completely satisfactory text’. These were optimistic words, and Lindsay himself, in his subsequent editions, first of the Captivi and then of the complete plays, did much to advance Plautine textual studies along the hopeful lines he prophesied.