2,252 research outputs found
Boden als Lebensraum fĂĽr Bodenorganismen : bodenbiologische Standortklassifikation ; Literaturstudie
Im Auftrag des Landes Baden-Württemberg, vertreten durch die Landesanstalt für Umweltschutz Baden-Württemberg (LfU Karlsruhe), wurde eine Literaturrecherche zum Thema Bodenfauna und Umwelt durchgeführt. Das Ziel dieser Studie ist, Informationen darüber zusammenzutragen, ob und auf welche Weise das Vorkommen und die Aktivität der Bodenorganismen (Mikroflora und Invertebraten) von pedologischen und biologischen Standortfaktoren abhängt. Dazu wurden insgesamt ca. 7000 wissenschaftliche Veröffentlichungen in eine Literaturdatei aufgenommen und mit Hilfe eines festgelegten Katalogs von Begriffen (Tiergruppen, Meßparameter, Standortfaktoren) verschlagwortet. Aufbauend auf dieser Literaturauswertung wird die Rolle und Bedeutung der Bodenorganismen für terrestrische Ökosysteme Zusammenfassend dargestellt (Kap. 3). Insbesondere wird der Aufbau (= Struktur) und die naturhaushaltliche Leistung (= Funktion) von Bodenbiozönosen - speziell Mitteleuropas - beschrieben. Zunächst wird dazu eine kurze Übersicht über die Mikroflora (Bakterien und Pilze) gegeben, da die Interaktion zwischen Mikroflora und Bodenfauna eines der wichtigsten Elemente im bodenbiologischen Geschehen darstellt. Aus der großen Zahl bodenlebender Organismen werden dann einige Tiergruppen genauer vorgestellt, die aufgrund ihrer hohen Wertigkeit für das gesamte Ökosystem (z.B. Regenwürmer) sowie als Repräsentanten verschiedener trophischer Ebenen (saprophag: Enchytraeen, Lumbriciden, Isopoden, Oribatiden, Diplopoden; zoophag: Gamasinen, Chilopoden, Carabiden; polyphag: Formiciden) und raum-zeitlicher Skalen ausgewählt werden
Cavity Assisted Nondestructive Laser Cooling of Atomic Qubits
We analyze two configurations for laser cooling of neutral atoms whose
internal states store qubits. The atoms are trapped in an optical lattice which
is placed inside a cavity. We show that the coupling of the atoms to the damped
cavity mode can provide a mechanism which leads to cooling of the motion
without destroying the quantum information.Comment: 12 page
Linear atomic quantum coupler
In this paper, we develop the notion of the linear atomic quantum coupler.
This device consists of two modes propagating into two waveguides, each of them
includes a localized and/or a trapped atom. These waveguides are placed close
enough to allow exchanging energy between them via evanescent waves. Each mode
interacts with the atom in the same waveguide in the standard way, i.e. as the
Jaynes-Cummings model (JCM), and with the atom-mode in the second waveguide via
evanescent wave. We present the Hamiltonian for the system and deduce the exact
form for the wavefunction. We investigate the atomic inversions and the
second-order correlation function. In contrast to the conventional linear
coupler, the atomic quantum coupler is able to generate nonclassical effects.
The atomic inversions can exhibit long revival-collapse phenomenon as well as
subsidiary revivals based on the competition among the switching mechanisms in
the system. Finally, under certain conditions, the system can yield the results
of the two-mode JCM.Comment: 14 pages, 3 figures; comments are most welcom
Consensus Paper: Neurophysiological Assessments of Ataxias in Daily Practice
The purpose of this consensus paper is to review electrophysiological abnormalities and to provide a guideline of neurophysiological assessments in cerebellar ataxias. All authors agree that standard electrophysiological methods should be systematically applied in all cases of ataxia to reveal accompanying peripheral neuropathy, the involvement of the dorsal columns, pyramidal tracts and the brainstem. Electroencephalography should also be considered, although findings are frequently non-specific. Electrophysiology helps define the neuronal systems affected by the disease in an individual patient and to understand the phenotypes of the different types of ataxia on a more general level. As yet, there is no established electrophysiological measure which is sensitive and specific of cerebellar dysfunction in ataxias. The authors agree that cerebellar brain inhibition (CBI), which is based on a paired-pulse transcranial magnetic stimulation (TMS) paradigm assessing cerebellar-cortical connectivity, is likely a useful measure of cerebellar function. Although its role in the investigation and diagnoses of different types of ataxias is unclear, it will be of interest to study its utility in this type of conditions. The authors agree that detailed clinical examination reveals core features of ataxia (i.e., dysarthria, truncal, gait and limb ataxia, oculomotor dysfunction) and is sufficient for formulating a differential diagnosis. Clinical assessment of oculomotor function, especially saccades and the vestibulo-ocular reflex (VOR) which are most easily examined both at the bedside and with quantitative testing techniques, is of particular help for differential diagnosis in many cases. Pure clinical measures, however, are not sensitive enough to reveal minute fluctuations or early treatment response as most relevant for pre-clinical stages of disease which might be amenable to study in future intervention trials. The authors agree that quantitative measures of ataxia are desirable as biomarkers. Methods are discussed that allow quantification of ataxia in laboratory as well as in clinical and real-life settings, for instance at the patients' home. Future studies are needed to demonstrate their usefulness as biomarkers in pharmaceutical or rehabilitation trials
Dynamical Coupling between a Bose-Einstein Condensate and a Cavity Optical Lattice
A Bose-Einstein condensate is dispersively coupled to a single mode of an
ultra-high finesse optical cavity. The system is governed by strong
interactions between the atomic motion and the light field even at the level of
single quanta. While coherently pumping the cavity mode the condensate is
subject to the cavity optical lattice potential whose depth depends nonlinearly
on the atomic density distribution. We observe bistability already below the
single photon level and strong back-action dynamics which tunes the system
periodically out of resonance.Comment: 5 pages, 4 figure
Grass is not always greener: rodenticide exposure of a threatened species near marijuana growing operations
Marijuana (Cannabis spp.) growing operations (MGO) in California have increased substantially since the mid-1990s. One environmental side-effect of MGOs is the extensive use of anticoagulant rodenticides (AR) to prevent damage to marijuana plants caused by wild rodents. In association with a long-term demographic study, we report on an observation of brodifacoum AR exposure in a threatened species, the northern spotted owl (Strix occidentalis caurina), found freshly dead within 669–1347 m of at least seven active MGOs
Fast cavity-enhanced atom detection with low noise and high fidelity
Cavity quantum electrodynamics describes the fundamental interactions between
light and matter, and how they can be controlled by shaping the local
environment. For example, optical microcavities allow high-efficiency detection
and manipulation of single atoms. In this regime fluctuations of atom number
are on the order of the mean number, which can lead to signal fluctuations in
excess of the noise on the incident probe field. Conversely, we demonstrate
that nonlinearities and multi-atom statistics can together serve to suppress
the effects of atomic fluctuations when making local density measurements on
clouds of cold atoms. We measure atom densities below 1 per cavity mode volume
near the photon shot-noise limit. This is in direct contrast to previous
experiments where fluctuations in atom number contribute significantly to the
noise. Atom detection is shown to be fast and efficient, reaching fidelities in
excess of 97% after 10 us and 99.9% after 30 us.Comment: 7 pages, 4 figures, 1 table; extensive changes to format and
discussion according to referee comments; published in Nature Communications
with open acces
Recommendations for a core outcome set for measuring standing balance in adult populations: a consensus-based approach
Standing balance is imperative for mobility and avoiding falls. Use of an excessive number of standing balance measures has limited the synthesis of balance intervention data and hampered consistent clinical practice.To develop recommendations for a core outcome set (COS) of standing balance measures for research and practice among adults.A combination of scoping reviews, literature appraisal, anonymous voting and face-to-face meetings with fourteen invited experts from a range of disciplines with international recognition in balance measurement and falls prevention. Consensus was sought over three rounds using pre-established criteria.The scoping review identified 56 existing standing balance measures validated in adult populations with evidence of use in the past five years, and these were considered for inclusion in the COS.Fifteen measures were excluded after the first round of scoring and a further 36 after round two. Five measures were considered in round three. Two measures reached consensus for recommendation, and the expert panel recommended that at a minimum, either the Berg Balance Scale or Mini Balance Evaluation Systems Test be used when measuring standing balance in adult populations.Inclusion of two measures in the COS may increase the feasibility of potential uptake, but poses challenges for data synthesis. Adoption of the standing balance COS does not constitute a comprehensive balance assessment for any population, and users should include additional validated measures as appropriate.The absence of a gold standard for measuring standing balance has contributed to the proliferation of outcome measures. These recommendations represent an important first step towards greater standardization in the assessment and measurement of this critical skill and will inform clinical research and practice internationally
Rotational master equation for cold laser-driven molecules
The equations of motion for the molecular rotation are derived for
vibrationally cold dimers that are polarized by off-resonant laser light. It is
shown that, by eliminating electronic and vibrational degrees of freedom, a
quantum master equation for the reduced rotational density operator can be
obtained. The coherent rotational dynamics is caused by stimulated Raman
transitions, whereas spontaneous Raman transitions lead to decoherence in the
motion of the quantized angular momentum. As an example the molecular dynamics
for the optical Kerr effect is chosen, revealing decoherence and heating of the
molecular rotation.Comment: 11 pages, 5 figures, to appear in Phys. Rev.
- …