A5018548802- Astro and Planetary Science
- Planetary Science and Exploration
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Gamma-ray bursts and supernovae
- Geomagnetism and Paleomagnetism Studies
- Stellar, planetary, and galactic studies
- Geology and Paleoclimatology Research
- Spacecraft and Cryogenic Technologies
- Health disparities and outcomes
- Geophysics and Gravity Measurements
- Space Satellite Systems and Control
- Space Exploration and Technology
- Wildlife Ecology and Conservation
- Atmospheric Ozone and Climate
- Animal Behavior and Reproduction
- GNSS positioning and interference
- Evolutionary Psychology and Human Behavior
- Species Distribution and Climate Change
- Insurance, Mortality, Demography, Risk Management
- Astronomical Observations and Instrumentation
- Aging and Gerontology Research
- Migration, Aging, and Tourism Studies
- Religion, Spirituality, and Psychology
- Underwater Vehicles and Communication Systems
University of Hertfordshire
2024
University of Southern Denmark
2016-2021
University of Northampton
2017
Odense Municipality
2016-2017
Max Planck Institute for Demographic Research
2015-2016
University of Oxford
2015-2016
Western University
1998-2015
Max Planck Society
2012
University of Göttingen
2008
Royal College of Nursing
2000-2002
Women in almost all modern populations live longer than men. Research to date provides evidence for both biological and social factors influencing this gender gap. Conditions when men women experience extremely high levels of mortality risk are unexplored sources information. We investigate the survival sexes seven under extreme conditions from famines, epidemics, slavery. survived better men: In populations, they had lower across ages, and, with exception one slave population, lived on...
Significance Public interest in social and economic equality is burgeoning. We examine a related phenomenon, lifespan equality, using data from charismatic primate populations diverse human populations. Our study reveals three key findings. First, rises lockstep with life expectancy, across species separated by millions of years evolution over hundreds progress. Second, industrial humans differ more nonindustrial these measures than do other primates. Third, spite the astonishing progress...
The measurement of the directions radio meteors with an interferometric system is beset by two problems: (1) ambiguity in measured for antennas spaced more than λ/2 and (2) effects mutual impedance when are at less to avoid these ambiguities. In this paper we discuss between describe interferometer which both minimizes avoids ambiguities associated spacings larger λ/2. We have modeled a version design numerically show that under ideal conditions total span 4.5λ can yield accurate about 0.3°...
A quantitative model for the ablation of dustball meteors is presented. The assumes meteoric bodies are composed grains (approximately 10–6 g mass) held together by a lower boiling point ' glue '. Once reached detached. Light assumed to be produced only detached grains. For fainter than about |${+5}^\text{M}$|, above radiation ceiling, and heights such mass independent. brighter meteors, grain detachment occur simultaneously predicts approximately classical light curves.
Ambipolar diffusion coefficients in the meteor region have been measured using decay times determined with CLOVAR radar [ Hocking, 1997]. This parameter may then be used to infer information about atmospheric temperatures or pressures that region. In particular, we show annual variations . Our procedures, together underlying assumptions, are described, and our results compared CIRA (1986) empirical model as well other experimental data. These successful measurements possible because of use a...
The structure of the sporadic meteor complex is determined from data in 10 orbital surveys. In addition to previously known apex, helion, antihelion and northern toroidal sources, we find a southern source splitting apex source. size sources possible origin meteoroids each region are discussed
Understanding how the natural world will be impacted by environmental change over coming decades is one of most pressing challenges facing humanity. Addressing this challenge difficult because can generate both population-level plastic and evolutionary responses, with responses being either adaptive or nonadaptive. We develop an approach that links quantitative genetic theory data-driven structured models to allow prediction population via plasticity evolution. After introducing general new...
This paper describes a general approach for stochastic modeling of assets returns and liability cash-flows typical pensions insurer. On the asset side, we model investment on equities various classes fixed-income instruments including short- long-maturity fixed-rate bonds as well index-linked corporate bonds. risks are driven by future mortality developments price wage inflation. All risk factors modeled multivariate process that captures dynamics dependencies across different factors. The...
Abstract A 6‐year‐old, male, neutered domestic ferret ( Mustela putorius furo ) presented for mucopurulent discharge from the left ear with visible intraluminal soft tissue mass in vertical portion of canal on endoscopic exam. computed tomographic exam confirmed a confined to lumen canal. total ablation and lateral bulla osteotomy was performed. Initial histopathology diagnosed as ceruminous gland adenoma, lived excellent quality life 6 months. After months, swelling around site noted by...
The initial velocities of dust particles ejected from comets can often play a crucial role in the subsequent development resultant meteoroid stream. We seek to remedy some shortcomings Whipple's theory by including effects cooling sublimation ice and adiabatic expansion escaping gases. find that inclusion these does not yield results much different original model. pay particular attention with radii greater than 2 μm follow trajectories are substantially flow lines gas. also investigate...
Summary The global population size of African lions is plummeting, and many small fragmented populations face local extinction. Extinction risks are amplified through the common practice trophy hunting for males, which makes setting sustainable quotas a vital task. Various demographic models evaluate consequences on lion growth. However, none use unbiased estimates male age‐specific mortality because such do not exist. Until now, estimating from resighting records marked males has been...
We describe a method for producing high-resolution maps of the radiant distribution meteor activity over celestial sphere using single-station radio-meteor observations. The uses convolution technique and we show how suitable function can be chosen to enhance apparent shower radiants. apply this data produced by Canadian Meteor Orbit Radar system near London, Ontario that daily motion measured within fraction degree per day. has detected number weak showers have not been previously...
Violence in psychiatric inpatient units is a major and growing problem. Research interest has primarily focussed on patient characteristics. The role of staff factors the antecedents violent incidents been neglected, despite fact that behaviour may be more readily amenable to change than HOVIS study sought obtain views sample mental health nurses current clinical practice about staff-related factors, which they perceive contribute to, or protect against, occurrence incidents. A total 108...
Abstract. The radar system described here (CMOR) comprises a basic 5-element receiving system, co-located with pulsed transmitter, specifically designed to observe meteor echoes and determine their position in space an angular resolution of ~1° radial ~3 km. Two secondary sites, few km distant arranged form approximately right angle the base station, allow determination velocity (speed direction) that, together time occurrence, lead estimate orbit original meteoroid. Some equipment details...
In some primate species, pelage colorations at birth contrast with adult colorations. The intensity of natal coats and their phylogenetic distribution is highly variable within primates. Natal coat coloration seems to change in most species when infants become independent from mothers, but an accepted functional explanation for not available. Here we describe sexually dichromatic redfronted lemurs (Eulemur fulvus rufus) Kirindy Forest, propose a new hypothesis this phenomenon. are born male...
Abstract— Two‐station electro‐optical observations of the 1998 Leonid shower are presented. Precise heights and light curves were obtained for 79 meteors that ranged in brightness (at maximum luminosity) from +0.3 to +6.1 astronomical magnitude. The mean photometric mass data sample was 1.4 × 10 −6 kg. dependence magnitude at peak luminosity on zenith angle consistent with earlier studies faint sporadic meteors. For example, a meteoroid ∼1.0 10‐ 7 kg corresponds meteor about +4.5 magnitudes....
The initial radius of meteor ionization has significant effects on measured height distributions, velocity distributions and flux measurements underdense echoes determined from radar observations. Multifrequency observations are used to examine the train radius. A model been constructed explain observed distribution, tested 2001 Geminids. It is shown that fragmentation accounts for most part attenuation due finite size.
The ribbon-like model proposed by McIntosh & Hajduk for the structure of Halley meteor stream explained many features Eta Aquarid and Orionid showers. This is here verified quantitatively numerically integrating orbital motion up to 500 test particles over several millennia. Perturbations major planets, effect radiation pressure Poynting–Robertson drag, are all taken into account. cross-section becomes highly elongated in only a few thousand years. Concentrations particle distribution...