ABSTRACT
In several exoplanet systems the stellar rotation axis is not aligned with the normal to the orbital plane. For the class of ‘hot Jupiters’, a significant fraction of total angular momentum ...resides in the orbit. Orbit precessional motion has been observed in several such systems. We expect the tides raised by the orbiting exoplanet to induce normal mode oscillations in the host star, with the possibility of normal mode-orbit resonance. Gravity modes possess frequencies in the range of typical orbital Keplerian frequencies and their overtones. These resonances, confined to very narrow ranges of frequency space, would be highly improbable unless ‘resonance locking’ occurs, driven, for example, by structural and spin rate changes of the host star, operating on nuclear evolutionary time-scales. Resonance locking amplifies the amplitude of tidally driven oscillations, possibly by orders of magnitude, compared to the equilibrium tide displacements. We address the problem of precession and nutation in a system with a single exoplanet, with non-aligned spin and orbit axes, coupling the gravitational perturbations of normal mode distortions with orbital motion. Resonant modes are expected to have large amplitudes, contributing significantly to the gravitational perturbation already present due to rotational distortion of the star that gives rise to uniform orbital precession. The relative magnitude of rotational distortion and normal-mode perturbations is estimated. For Kepler-13Ab, estimates of their influence on transit time variations are given, and suggest they may be discernible with modern space telescope missions.
This book sets forth a provocative agenda for the scientific study of human personality. Blending no-nonsense empiricism with the humanistic desire to understand the whole person, the book is as ...relevant today as it was to its many readers seventy years ago. The book sets forth a full theory of human personality, illustrated with a bevy of creative methods for personality assessment, and presenting the results of a landmark study of fifty Harvard men. The book is one of the great classics in 20th-century psychology.
•Sea lice are a major problem for wild salmonid fish.•modelled as processes operating at a range of space and time scales.•Small scale swimming behaviour of sea lice has big impacts on infestation ...rate.•Infestation rates peak for fish of moderate to low velocity.•Understanding of these drivers is important for planning sustainable aquaculture.
Sea lice are marine ectoparasitic crustacea which limit the potential for sustainable salmon aquaculture due to risks of impacts on iconic wild salmon and sea trout. Control of the parasite on farms costs an estimated 9% of farm revenue. Sea lice develop through planktonic nauplii to copepodid stages which attach to, and mature on, salmonid hosts until females become ovigerous (egg laying) Impacts of lice on wild fish depend on their exposure to planktonic larval lice transported from salmon farms, which consists of (A) production of larval lice from ovigerous female lice on salmon farms, (B) local concentrations of planktonic larval lice infectious copepodids in adjacent waters, (C) rates of infestation of wild fish given these concentrations, and (D) impact on fish given this level of interaction. A model of this local exposure around salmon farms was developed. Production rates for nauplii as a function of the numbers of adult lice on salmon farms and maturation to copepodids (A) is well studied, as are impacts of infestation (D), with >0.75 lice per gram of host fish considered to present a high risk of mortality. Using existing assessments of infectious copepodid production (A) we develop a model of copepodid concentration (B) based on a simple kernel of copepodid distribution around farms; within this kernel the copepodids are assumed either to disperse evenly or to be transported in a concentrated plume, allowing comparison of the range of different concentration distributions. These distributions combine with a model of infestation (C) based on small-scale movements of copepodids in the immediate vicinity of a swimming fish. Fish swimming at intermediate velocities are most susceptible to infestation, as slow fish exhaust lice in their immediate vicinity while fast fish move on before lice copepodids can approach. These models are combined to create an assessment of the risk that concentrations can result in infestation of fish at levels considered to cause mortalities (D). The results can be used in combination with empirical assessments as a tool to link potential impacts on wild salmonids to aquaculture biomass and on-farm lice management in different environments in support of strategic aquaculture planning. Our modelling demonstrates the, often neglected, importance of fine-scale processes in sea lice infestation of salmonids.
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Properties of spherical wire antennas are revisited using a circuit analysis approach. This methodology yields the exact quality factor and axial ratio (AR) of coupled-mode spherical radiators as ...analytical expressions. The new circuit-based equations are compared to field integration predictions for quality factor, and both are found to agree for a general multipole expansion of the electromagnetic fields. These two predictions of stored energy inside a spherical wire antenna are shown to be equivalent via direct analysis, while predictions of stored energy outside the spherical wire antenna are compared by way of mathematical induction. In addition, the circuit analysis reveals general relations between supplied current and radiated power of spherical wire antennas, resonance conditions of coupled-mode systems, and analytical quantification of the trade-off between the quality factor and AR for TM<inline-formula> <tex-math notation="LaTeX">_{\boldsymbol {1m}} </tex-math></inline-formula>-TE<inline-formula> <tex-math notation="LaTeX">_{\boldsymbol {1m}} </tex-math></inline-formula> radiators. New and simple expressions for the minimum quality factor of circular, near-circular, linear, and general elliptical polarizations are provided.
Background
Burn outcomes can be improved by reducing mortality and hospital admission duration. This increases patient quality of life and reduces hospital‐associated complications and costs. This ...study aimed to develop a model with which to predict burns inpatient mortality and admission duration.
Methods
Multiple logistic and linear regression were used to investigate mortality and admission duration by age, total body surface area, sex, delay to presentation, the use of surgery, discharge distance and period.
Results
One thousand four hundred and seventy nine patients (747 pre‐COVID and 732 during COVID) were admitted between the study dates. Using multiple logistic regression, age and total body surface area predicted mortality LR X2 (5), P < 0.001, pseudo R2 = 0.57. Using multiple linear regression, age, total body surface area and the use of surgery predicted admission duration F (7, 1455) = 161.42, P < 0.001, R2 = 0.44. Sex, delay to presentation, period and discharge distance did not predict mortality or admission duration.
Conclusions
In our institution, mortality was increased by 8.6% for each additional year of age and by 11.3% for each additional percentage total body surface area. Likewise, admission duration was prolonged by 1 day for every 7 years of increased age, by 1 day for each additional percentage total body surface area or by 7 days if surgery was required. These models have been incorporated into a set of prediction tables for mortality and admission duration for use in our institute that can guide patient and family discussions.
Background
Surgical management of refractory focal epilepsy requires preoperative localisation of the epileptogenic zone (EZ). To augment noninvasive studies, stereoelectroencephalography (SEEG) is ...being increasingly adopted as a form of intracranial monitoring.
Aims
This study aimed to determine the rate of complications for patients undergoing SEEG and to report the success of SEEG with regard to EZ detection and seizure outcome following definitive surgery.
Methods
A retrospective cohort design investigated all cases of SEEG at our institution. Surgical, anaesthetic and medical complications with subsequent epilepsy surgery and seizure outcome data were extracted from medical records. Multivariate logistic regression was used to investigate the relationship between both the number of electrodes per patient and the duration of SEEG recording with the rate of complications.
Results
Sixty‐four patients with 66 implantations were included. Headache was the most common complication (n = 54, 82%). There were no major surgical or medical complications. Two anaesthetic complications occurred. EZ localisation was successful in 63 cases (95%). Curative intent surgery was performed in 39 patients (59%) and 23 patients achieved an Engel class I outcome (59% of those undergoing surgery). The number of electrodes and duration of recording were not associated with complications.
Conclusions
No patients in our series experienced major surgical or medical complications and we have highlighted the challenges associated with neuroanaesthesia in SEEG. Our complication rates and seizure outcomes are equivalent to published literature indicating that this technique can be successfully established in newer centres using careful case selection. Standardised reporting of SEEG complications should be adopted.
Economic theory and history show that labour productivity growth is the main driver of rising living standards, so changes in the trend rate of productivity growth have profound implications for a ...society's future prosperity. The average annual rate of business sector labour productivity growth in the United States declined by 1.9 percentage points between the 1995-2004 period and the 2004-2015 period, from 3.2 per cent to 1.3 per cent. This article summarizes the state of knowledge on the causes of the post-2004 slowdown in U.S. productivity growth. Official growth accounting estimates indicate that 60-65 per cent of the labour productivity decline is accounted for by a decline in total factor productivity growth, while 30-35 per cent is accounted for by a decline in the rate of capital deepening. Three industries account for over 80 per cent of the aggregate labour productivity decline: manufacturing, wholesale trade, and retail trade. The aggregate productivity slowdown is traceable to a decline in the productivity contributions arising from industries that produce or intensively use information and communication technology (ICT) products.
Sea lice control is a very important issue for sustainable salmon aquaculture, and cleaner fish (largely wrasse and lumpfish) are increasingly used as a key tool for this control. Such fish can carry ...pathogens, which they can potentially spread to the salmon. A modelling approach is used to help guide practice on cleaner fish use. The model simulates transmission of pathogens within and between cleaner fish and salmon populations. A function modifying the coefficient of infection allows simulation of pathogens input with cleaner fish to adaptation to salmon with passage. Adaption may require different numbers of passage events and may face obstacles that make adaption easier or more difficult, allowing the exploration of a range of potential emergent pathogens with different properties. The model includes the production cycle of salmon, whereby all salmon are periodically removed and replaced with naïve fish, but a proportion of the cleaner fish may be reused in the next production cycle. An assessment of the likely consequence of emergent diseases relative to consequence of sea lice infection is made using an analysis of literature. The modelling concludes that any emergent disease is unlikely to be of as serious consequence as sea lice already are, and therefore the risk from emergent disease is low relative to benefit of controlling lice. This risk can be further reduced by practices that limit input of infection and by restricting reused of cleaner fish in subsequent production cycle. The risk from reusing small numbers is generally substantially lower than reusing larger numbers, but avoiding reuse is more effective, especially if there is limited input of pathogens with new cleaner fish. More data as cleaner fish are increasingly used will allow more accurate assessment of risk, but the model provides a flexible framework for assessing risk of emergence of potential new pathogens and advising on good practice while information is limited and a precautionary approach is inappropriate owing to the clear benefits of effective lice control.
•Sustainable salmon aquaculture needs lice control.•Cleaner fish (C) increasingly important but can carry pathogens.•Model developed of accumulation of pathogens in C and spread to salmon (S).•Risk from emerging diseases likely to be much lower than that from failure to control lice.•Sources and options for mitigation of potential risk can be identified using modelling even under great uncertainties.
Totipotency is the ability of a single cell to give rise to all of the differentiated cell types that build the conceptus, yet how to capture this property in vitro remains incompletely understood. ...Defining totipotency relies on a variety of assays of variable stringency. Here, we describe criteria to define totipotency. We explain how distinct criteria of increasing stringency can be used to judge totipotency by evaluating candidate totipotent cell types in mice, including early blastomeres and expanded or extended pluripotent stem cells. Our data challenge the notion that expanded or extended pluripotent states harbour increased totipotent potential relative to conventional embryonic stem cells under in vitro and in vivo conditions.
A partial productivity measure relates output to a single input. Total factor productivity (or TFP) relates an index of output to a composite index of all inputs. This article reviews the strengths ...and weaknesses of each type of productivity measure from theoretical and methodological perspectives. Different productivity measures may be useful for different analytical purposes, and no single measure provides a complete picture of an industry's productivity performance. We argue for a balanced, context-appropriate approach to productivity analysis that incorporates both productivity measures.
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