1,102 research outputs found
Is sea-basing a viable method of providing logistic support to the UK amphibious force?
Maritime power has traditionally been a central part of the UK’s defence planning and is well
suited to supporting a wide range of military operations. The littoral area has always created
problems for naval planners as most landings historically have had to endure a tactical
separation of the naval and land components, and hence an artificial seam between the Navy
and the Marines. With the end of the Cold War, amphibious operations are going to be more
difficult to conduct than in the past, and amphibious forces are going to have to adopt
manoeuvre warfare capabilities in order to successfully complete their missions. It is very
likely that amphibious forces will have to conduct operations against a numerically superior
enemy, who is on his own terrain, and be surrounded by a neutral, if not hostile populace. As
such, the concept of Operational Manoeuvre From The Sea (OMFTS) whereby the sea is used
as a manoeuvre space, and command and control is fast enough to cope with large amounts of
information, but at the same time allow subordinates maximum flexibility to use their
initiative, is increasingly attractive. It will be important not only for the combat elements to be
able to use this new concept, but the Combat Service Support (CSS) elements as well
Lung cancer in Hong Kong Chinese: mortality and histological types, 1960-1972.
Age-adjusted mortality from lung cancer rose rapidly in both males and females in Hong Kong from 1960-1972. The relative frequency of epidermoid carcinoma increased in male bronchial biopsies but not in lung biopsies, resections, or autopsies; there was a decline in small-cell anaplastic carcinoma. In both males and females the ratio of Kreyberg Group I (epidermoid and small-cell anaplastic) to Group II (adenocarcinoma and carcinoid) tumours did not increase, despite an 80% rise in mortality from lung cancer. Adenocarcinoma was the most common type in females, despite the high mortality from lung cancer. It is speculated that cigarette smoking might produce a different pattern of histological types among Hong Kong Chinese, or that additional aetiological factors may be operating there
Front propagation into unstable and metastable states in Smectic C* liquid crystals: linear and nonlinear marginal stability analysis
We discuss the front propagation in ferroelectric chiral smectics (SmC*)
subjected to electric and magnetic fields applied parallel to smectic layers.
The reversal of the electric field induces the motion of domain walls or fronts
that propagate into either an unstable or a metastable state. In both regimes,
the front velocity is calculated exactly. Depending on the field, the speed of
a front propagating into the unstable state is given either by the so-called
linear marginal stability velocity or by the nonlinear marginal stability
expression. The cross-over between these two regimes can be tuned by a magnetic
field. The influence of initial conditions on the velocity selection problem
can also be studied in such experiments. SmC therefore offers a unique
opportunity to study different aspects of front propagation in an experimental
system
Cancer of the oral cavity, pharynx/larynx and lung in North Thailand: case-control study and analysis of cigar smoke.
The unusually high relative frequency of cancer in the laryngeal region in males (18% of all histologically diagnosed cancers) and a sex ratio of unity for lung cancer in Northern Thailand were further explored in a hospital-based case-control study in Chiang Mai. This compared patients having cancers of the oral cavity (including oropharynx), larynx, hypopharynx and lung, with controls in relation to smoking and chewing habits. Statistical analysis indicated that chewing betel is strongly associated with the occurrence of oral cancer in both sexes, and with cancer of the laryngeal region in males. No factors were strongly linked to lung cancer in men, but, in women, urban residence and miang chewing were associated with lung cancer. Analysis of smoke from the two main types of cigars smoked in the region showed that both had high tar content, but there were marked differences in pH. Smoking cigars with alkaline smoke and high tar had an increased risk for laryngeal cancer in males, whereas other cigars with acid smoke and high tar together with manufactured cigarettes had increased risks for lung cancer. These increased risks were not, however, statistically significant
Structures and orientational transitions in thin films of tilted hexatic smectics
We present detailed systematic studies of structural transformations in thin
liquid crystal films with the smectic-C to hexatic phase transition. For the
first time all possible structures reported in the literature are observed for
one material (5 O.6) at the variation of temperature and thickness. In unusual
modulated structures the equilibrium period of stripes is twice with respect to
the domain size. We interpret these patterns in the frame work of
phenomenological Landau type theory, as equilibrium phenomena produced by a
natural geometric frustration in a system having spontaneous splay distortion.Comment: 7 pages, 6 figure
Solar Energetic Particle Spectral Breaks
The five large solar particle events during October–November 2003 presented an opportunity to test shock acceleration models with in-situ observations. We use solar particle spectra of H to Fe ions, measured by instruments on ACE, SAMPEX, and GOES-11, to investigate the Q/M-dependence of spectral breaks in the 28 October 2003 event. We find that the break energies scale as (Q/M)^b with b ≈ 1.56 to 1.75, somewhat less than predicted. We also conclude that SEP spectra >100 MeV/nucleon are best fit by a double power-law shape. ©2005 American Institute of Physic
Evidence for Remnant Flare Suprathermals In The Source Population of Solar Energetic Particles In The 2000 Bastille Day Event
The energy spectra of Fe in the very large solar energetic particle (SEP) event of 2000 July 14 are strikingly
different from those of lighter species. We show that this difference can be explained by shock acceleration from
a two-component source population, comprising solar wind suprathermals and a small (∼5%) admixture of remnant
flare particles, as previously proposed to explain enhanced ^3He/^4He in some gradual SEP events. Flare remnants
can also account for several previously unexplained features of high-energy solar heavy ions as well as important aspects of SEP event-to-event variability. These results offer a new perspective on the enduring controversy over the relative roles of flares and coronal mass ejections (CMEs) in producing SEPs. Flare activity clearly makes a unique and critical contribution to the source population. But the predominate accelerator in large gradual SEP events is the CME-driven shock, and many spectral, compositional, and charge state characteristics of highenergy heavy ions can be understood without invoking other acceleration mechanisms
Drivers of spatial change in urban housing submarkets
Spatial urban housing submarkets are now widely used constructs. Recent housing market modelling strategies have emphasised the need for flexibility in modelling approaches in order to best accommodate submarkets which account for spatial variations in hedonic prices. But this raises important unanswered questions concerning the stability of submarket structures over time, and the role of housing market dynamics in breaking down or shifting submarket boundaries. The influence of new supply, in particular, may have a stabilising or destabilising effect on differences in hedonic prices, depending on the wider housing market context. In this paper we examine the temporal influence of new supply, intra‐urban migration and socio‐economic change as a means of understanding the impact of key drivers of submarket boundary change. Using the Greater Perth region of Western Australia as a case study, we estimate income elasticities of demand for housing services that vary spatially within the urban area. We find evidence that higher income elasticities, new development, socio‐economic change and intra‐urban migration are associated with changes in the spatial structure of housing prices within the metropolitan housing market
Changes in serogroup and genotype prevalence among carried meningococci in the United Kingdom during vaccine implementation.
BACKGROUND: Herd immunity is important in the effectiveness of conjugate polysaccharide vaccines against encapsulated bacteria. A large multicenter study investigated the effect of meningococcal serogroup C conjugate vaccine introduction on the meningococcal population. METHODS: Carried meningococci in individuals aged 15-19 years attending education establishments were investigated before and for 2 years after vaccine introduction. Isolates were characterized by multilocus sequence typing, serogroup, and capsular region genotype and changes in phenotypes and genotypes assessed. RESULTS: A total of 8462 meningococci were isolated from 47 765 participants (17.7%). Serogroup prevalence was similar over the 3 years, except for decreases of 80% for serogroup C and 40% for serogroup 29E. Clonal complexes were associated with particular serogroups and their relative proportions fluctuated, with 12 statistically significant changes (6 up, 6 down). The reduction of ST-11 complex serogroup C meningococci was probably due to vaccine introduction. Reasons for a decrease in serogroup 29E ST-254 meningococci (from 1.8% to 0.7%) and an increase in serogroup B ST-213 complex meningococci (from 6.7% to 10.6%) were less clear. CONCLUSIONS: Natural fluctuations in carried meningococcal genotypes and phenotypes a can be affected by the use of conjugate vaccines, and not all of these changes are anticipatable in advance of vaccine introduction
Modeling Life as Cognitive Info-Computation
This article presents a naturalist approach to cognition understood as a
network of info-computational, autopoietic processes in living systems. It
provides a conceptual framework for the unified view of cognition as evolved
from the simplest to the most complex organisms, based on new empirical and
theoretical results. It addresses three fundamental questions: what cognition
is, how cognition works and what cognition does at different levels of
complexity of living organisms. By explicating the info-computational character
of cognition, its evolution, agent-dependency and generative mechanisms we can
better understand its life-sustaining and life-propagating role. The
info-computational approach contributes to rethinking cognition as a process of
natural computation in living beings that can be applied for cognitive
computation in artificial systems.Comment: Manuscript submitted to Computability in Europe CiE 201
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