Microtectonics Passchier, C. W; Trouw, R. A. J
1998, 1998.
eBook
Microtectonics is the interpretation of small-scale deformation structures in rocks. They are studied by optical microscope and contain abundant information on the history and type of deformation and ...metamorphism in a rock and are therefore used by most geologists to obtain data for large-scale geological interpretations. This advanced textbook contains a large number of photographs and explanatory drawings, special chapters on related techniques, a chapter on microgauges and a simple, non-mathematical treatment of continuum mechanics with practical examples. Special terms are explained in boxes. This textbook is suited for independent use during optical studies on microstructures as a reference manual and as a manual for short courses.
Microtectonics, the interpretation of small-scale deformation structures in rocks, is done with optical microscope and yields abundant information on the history and type of deformation and ...metamorphism in rocks. The results are used by geologists to obtain data for large-scale geological interpretations. This advanced textbook treats common microstructures such as foliations, porphyroblasts, veins, fringes and shear sense. It also provides information on experimental work and the techniques of microtectonic research. Many photographs and explanatory drawings clarify the text. The new edition, substantially revised throughout and extended, features two new chapters (primary structures and experimental microstructures), 90 new figures, 600 new references and a CD with color photos, images, and animations, exercises and questions as well as a glossary. Microtectonics has proven useful for self study of microstructures and as a manual for short- and one-semester courses.
Alzheimer’s disease (AD) is the most common progressive human neurodegenerative disorder affecting elderly population worldwide. Hence, prevention of AD has been a priority of AD research worldwide. ...Based on understanding of disease mechanism, different therapeutic strategies involving synthetic and herbal approaches are being used against AD. Among the herbal extract,
Ginkgo biloba
extract (GBE) is one of the most investigated herbal remedy for cognitive disorders and Alzheimer’s disease (AD). Standardized extract of
Ginkgo biloba
is a popular dietary supplement taken by the elderly population to improve memory and age-related loss of cognitive function. Nevertheless, its efficacy in the prevention and treatment of dementia remains controversial. Specifically, the added effects of GBE in subjects already receiving “conventional” anti-dementia treatments have been to date very scarcely investigated. This review summarizes recent advancements in our understanding of the potential use of
Ginkgo biloba
extract in the prevention of AD including its antioxidant property. A better understanding of the mechanisms of action of GBE against AD will be important for designing therapeutic strategies, for basic understanding of the underlying neurodegenerative processes, and for a better understanding of the effectiveness and complexity of this herbal medicine.
Generalised kinematics for double field theory Freidel, Laurent; Rudolph, Felix J.; Svoboda, David
The journal of high energy physics,
11/2017, Letnik:
2017, Številka:
11
Journal Article
Recenzirano
Odprti dostop
A
bstract
We formulate a kinematical extension of Double Field Theory on a 2
d
-dimensional para-Hermitian manifold
P
η
ω
where the
O
(
d, d
) metric
η
is supplemented by an almost symplectic ...two-form
ω
. Together
η
and
ω
define an almost bi-Lagrangian structure
K
which provides a splitting of the tangent bundle
T
P
=
L
⊕
L
˜
into two Lagrangian sub-spaces. In this paper a canonical connection and a corresponding generalised Lie derivative for the Leibniz algebroid on
T
P
are constructed. We find integrability conditions under which the symmetry algebra closes for general
η
and
ω
, even if they are not flat and constant. This formalism thus provides a generalisation of the kinematical structure of Double Field Theory. We also show that this formalism allows one to reconcile and unify Double Field Theory with Generalised Geometry which is thoroughly discussed.
Systematic review of possible long-term effects of sports-related concussion in retired athletes.
Ten electronic databases.
Original research; incidence, risk factors or causation related to ...long-term mental health or neurological problems; individuals who have suffered a concussion; retired athletes as the subjects and possible long-term sequelae defined as
10 years after the injury.
Study population, exposure/outcome measures, clinical data, neurological examination findings, cognitive assessment, neuroimaging findings and neuropathology results. Risk of bias and level of evidence were evaluated by two authors.
Following review of 3819 studies, 47 met inclusion criteria. Some former athletes have depression and cognitive deficits later in life, and there is an association between these deficits and multiple prior concussions. Former athletes are not at increased risk for death by suicide (two studies). Former high school American football players do not appear to be at increased risk for later life neurodegenerative diseases (two studies). Some retired professional American football players may be at increased risk for diminishment in cognitive functioning or mild cognitive impairment (several studies), and neurodegenerative diseases (one study). Neuroimaging studies show modest evidence of macrostructural, microstructural, functional and neurochemical changes in some athletes.
Multiple concussions appear to be a risk factor for cognitive impairment and mental health problems in some individuals. More research is needed to better understand the prevalence of chronic traumatic encephalopathy and other neurological conditions and diseases, and the extent to which they are related to concussions and/or repetitive neurotrauma sustained in sports.
A
bstract
The doubled target space of the fundamental closed string is identified with its phase space and described by an almost para-Hermitian geometry. We explore this setup in the context of ...group manifolds which admit a maximally isotropic subgroup. This leads to a formulation of the Poisson-Lie
σ
-model and Poisson-Lie T-duality in terms of para-Hermitian geometry. The emphasis is put on so called half-integrable setups where only one of the Lagrangian subspaces of the doubled space has to be integrable. Using the dressing coset construction in Poisson-Lie T-duality, we extend our construction to more general coset spaces. This allows to explicitly obtain a huge class of para-Hermitian geometries. Each of them is automatically equipped which a generalized frame field, required for consistent generalized Scherk-Schwarz reductions. As examples we present integrable
λ
- and
η
-deformations on the three- and two-sphere.
Highly charged iron (Fe(16+), here referred to as Fe XVII) produces some of the brightest X-ray emission lines from hot astrophysical objects, including galaxy clusters and stellar coronae, and it ...dominates the emission of the Sun at wavelengths near 15 ångströms. The Fe XVII spectrum is, however, poorly fitted by even the best astrophysical models. A particular problem has been that the intensity of the strongest Fe XVII line is generally weaker than predicted. This has affected the interpretation of observations by the Chandra and XMM-Newton orbiting X-ray missions, fuelling a continuing controversy over whether this discrepancy is caused by incomplete modelling of the plasma environment in these objects or by shortcomings in the treatment of the underlying atomic physics. Here we report the results of an experiment in which a target of iron ions was induced to fluoresce by subjecting it to femtosecond X-ray pulses from a free-electron laser; our aim was to isolate a key aspect of the quantum mechanical description of the line emission. Surprisingly, we find a relative oscillator strength that is unexpectedly low, differing by 3.6σ from the best quantum mechanical calculations. Our measurements suggest that the poor agreement is rooted in the quality of the underlying atomic wavefunctions rather than in insufficient modelling of collisional processes.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Purpose
Severe postoperative pain following spine surgery is a significant cause of morbidity, extended length of facility stay, and marked opioid usage. The erector spinae plane (ESP) block ...anesthetizes the dorsal rami of spinal nerves that innervate the paraspinal muscles and bony vertebra. We describe the use of low thoracic ESP blocks as part of multimodal analgesia in lumbosacral spine surgery.
Clinical features
We performed bilateral ESP blocks at the T10 or T12 level in six cases of lumbosacral spine surgery: three lumbar decompressions, two sacral laminoplasties, and one coccygectomy. Following induction of general anesthesia, single-injection ESP blocks were performed in three patients while bilateral continuous ESP block catheters were placed in the remaining three. All six patients had minimal postoperative pain and very low postoperative opioid requirements. There was no discernible motor or sensory block in any of the cases and no interference with intraoperative somatosensory evoked potential monitoring used in two of the cases.
Conclusions
The ESP block can contribute significantly to a perioperative multimodal opioid-sparing analgesic regimen and enhance recovery after lumbosacral spine surgery.
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