AbstractPassive air-jet blowing is an effective yet simple technique to control flow-induced noise due to vortex shedding of bluff bodies. The current study investigates the effect of the specific ...slot angles of passive jets in connection with the suppression capabilities of vortex shedding and the byproduct of vortex-induced noise in the wake region of a circular cylinder. Aeroacoustic tests for a baseline case and 10 different slotted cases with slot angles of 80°≤θ≤125° are performed for Reynolds numbers 6.6×103≤R≤3.3×104. This is supplemented by numerical computational fluid dynamics (CFD) analyses to identify the underlying aerodynamic mechanisms. The results obtained reveal that using the current passive control method results in a significant reduction of the vortex shedding tonal noise for slot angles of 90°≤θ≤125° and high Reynolds numbers. The numerical results showed good agreement with a remarkably reduced kinetic energy for slot-end angles of 115°≤θ≤125°. At low Reynolds numbers, however, the identified aeroacoustic benefits tend to cease.
Small molecules that increase the presynaptic function of aminergic cells may provide neuroprotection in Parkinson's disease (PD) as well as treatments for attention deficit hyperactivity disorder ...(ADHD) and depression. Model genetic organisms such as Drosophila melanogaster may enhance the detection of new drugs via modifier or 'enhancer/suppressor' screens, but this technique has not been applied to processes relevant to psychiatry. To identify new aminergic drugs in vivo, we used a mutation in the Drosophila vesicular monoamine transporter (dVMAT) as a sensitized genetic background and performed a suppressor screen. We fed dVMAT mutant larvae ∼ 1000 known drugs and quantitated rescue (suppression) of an amine-dependent locomotor deficit in the larva. To determine which drugs might specifically potentiate neurotransmitter release, we performed an additional secondary screen for drugs that require presynaptic amine storage to rescue larval locomotion. Using additional larval locomotion and adult fertility assays, we validated that at least one compound previously used clinically as an antineoplastic agent potentiates the presynaptic function of aminergic circuits. We suggest that structurally similar agents might be used to development treatments for PD, depression and ADHD, and that modifier screens in Drosophila provide a new strategy to screen for neuropsychiatric drugs. More generally, our findings demonstrate the power of physiologically based screens for identifying bioactive agents for select neurotransmitter systems.
•A novel framework for nondestructive evaluation with resonance is established.•Multiple damage mechanisms, including creep deformation and cracks, are evaluated.•FE models capture the dominant ...damage mechanisms affecting resonance.•Experiments on Ni-based superalloy samples validate FE models and NDE methods.
Finite element (FE) modeling has been coupled with resonant ultrasound spectroscopy (RUS) for nondestructive evaluation (NDE) of high temperature damage induced by mechanical loading. Forward FE models predict mode-specific changes in resonance frequencies (ΔfR), inform RUS measurements of mode-type, and identify diagnostic resonance modes sensitive to individual or multiple concurrent damage mechanisms. The magnitude of modeled ΔfR correlate very well with the magnitude of measured ΔfR from RUS, affording quantitative assessments of damage. This approach was employed to study creep damage in a polycrystalline Ni-based superalloy (Mar-M247) at 950°C. After iterative applications of creep strains up to 8.8%, RUS measurements recorded ΔfR that correspond to the accumulation of plastic deformation and cracks in the gauge section of a cylindrical dog-bone specimen. Of the first 50 resonance modes that occur, ranging from 3 to 220kHz, modes classified as longitudinal bending were most sensitive to creep damage while transverse bending modes were found to be largely unaffected. Measure to model comparisons of ΔfR show that the deformation experienced by the specimen during creep, specifically uniform elongation of the gauge section, is responsible for a majority of the measured ΔfR until at least 6.1% creep strain. After 8.8% strain considerable surface cracking along the gauge section of the dog-bone was observed, for which FE models indicate low-frequency longitudinal bending modes are significantly affected. Key differences between historical implementations of RUS for NDE and the FE model-based framework developed herein are discussed, with attention to general implementation of a FE model-based framework for NDE of damage.
Glucose, fructose, sucrose, free asparagine, and free glutamine were analyzed in 74 potato samples from 17 potato cultivars grown in 2002 at various locations in Switzerland and different farming ...systems. The potential of these potatoes for acrylamide formation was measured with a standardized heat treatment. These potentials correlated well with the product of the concentrations of reducing sugars and asparagine. Glucose and fructose were found to determine acrylamide formation. The cultivars showed large differences in their potential of acrylamide formation which was primarily related to their sugar contents. Agricultural practice neither influenced sugars and free asparagine nor the potential of acrylamide formation. It is concluded that acrylamide contents in potato products can be substantially reduced primarily by selecting cultivars with low concentrations of reducing sugars. Keywords: Potato cultivar; farming systems; potential of acrylamide formation; sugars; asparagine
Numerous studies have revealed genetic similarities between Tethyan
ophiolites and oceanic “proto-arc” sequences formed above nascent subduction
zones. The Semail ophiolite (Oman–U.A.E.) in ...particular can be viewed as an
analogue for this proto-arc crust. Though proto-arc magmatism and the
mechanisms of subduction initiation are of great interest, insight is
difficult to gain from drilling and limited surface outcrops in marine
settings. In contrast, the 3–5 km thick upper-crustal succession of the
Semail ophiolite, which is exposed in an oblique cross section, presents an
opportunity to assess the architecture and volumes of different volcanic
rocks that form during the proto-arc stage. To determine the distribution of
the volcanic rocks and to aid exploration for the volcanogenic massive
sulfide (VMS) deposits that they host, we have remapped the volcanic units
of the Semail ophiolite by integrating new field observations, geochemical
analyses, and geophysical interpretations with pre-existing geological maps.
By linking the major-element compositions of the volcanic units to rock
magnetic properties, we were able to use aeromagnetic data to infer the
extension of each outcropping unit below sedimentary cover, resulting in
a new map showing 2100 km2 of upper-crustal bedrock. Whereas earlier maps distinguished two main volcanostratigraphic units, we
have distinguished four, recording the progression from early spreading-axis
basalts (Geotimes), through axial to off-axial depleted basalts (Lasail), to
post-axial tholeiites (Tholeiitic Alley), and finally boninites (Boninitic
Alley). Geotimes (“Phase 1”) axial dykes and lavas make up ∼55 vol % of the Semail upper crust, whereas post-axial (“Phase 2”) lavas
constitute the remaining ∼45 vol % and ubiquitously cover
the underlying axial crust. Highly depleted boninitic members of the Lasail
unit locally occur within and directly atop the axial sequence, marking an
earlier onset of boninitic magmatism than previously known for the
ophiolite. The vast majority of the Semail boninites, however, belong to the
Boninitic Alley unit and occur as discontinuous accumulations up to 2 km
thick at the top of the ophiolite sequence and constitute ∼15 vol % of the upper crust. The new map provides a basis for targeted
exploration of the gold-bearing VMS deposits hosted by these boninites. The
thickest boninite accumulations occur in the Fizh block, where magma ascent
occurred along crustal-scale faults that are connected to shear zones in the
underlying mantle rocks, which in turn are associated with economic
chromitite deposits. Locating major boninite feeder zones may thus be an
indirect means to explore for chromitites in the underlying mantle.
Ternary complexes between the macrocyclic host cucurbit8uril, dicationic dyes, and chiral aromatic analytes afford strong induced circular dichroism (ICD) signals in the near‐UV and visible regions. ...This allows for chirality sensing and peptide‐sequence recognition in water at low micromolar analyte concentrations. The reversible and noncovalent mode of binding ensures an immediate response to concentration changes, which allows the real‐time monitoring of chemical reactions. The introduced supramolecular method is likely to find applications in bioanalytical chemistry, especially enzyme assays, for drug‐related analytical applications, and for continuous monitoring of enantioselective reactions, particularly asymmetric catalysis.
Strong and diagnostic induced circular dichroism signals in the near‐UV or visible region are obtained when chiral, optically transparent analytes bind to an achiral chemosensing ensemble composed of a macrocyclic host and dye. This affords a novel, supramolecular detection method for chiral aromatic analytes in water.
Currently no treat-to-target framework to guide systemic treatment in adults with moderate-to-severe atopic dermatitis exists. We sought to reach international consensus through an eDelphi process on ...a core set of recommendations for such an approach. Recommendations were developed by an international Steering Committee, spanning 3 areas (Guiding Principles, Decision Making, and Outcome Thresholds) and 2 specific time-points; an initial acceptable target at 3 months and an optimal target at 6 months, each based on improvements in patient global assessment plus at least one specific outcome domain. These treat-to-target- orientated recommendations were evaluated by an extended international panel of physicians, nurses and patients. Proposed recommendations were rated using a 9-point Likert scale; for each recommendation, consensus agreement was reached if ≥ 75% of all respondents rated agreement as ≥ 7. Consensus on 16 core recommendations was reached over 2 eDelphi rounds. These provide a framework for shared decision-making on systemic treatment continuation, modification, or discontinuation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
We present ultra high speed optical coherence tomography (OCT) with multi-megahertz line rates and investigate the achievable image quality. The presented system is a swept source OCT setup using a ...Fourier domain mode locked (FDML) laser. Three different FDML-based swept laser sources with sweep rates of 1, 2.6 and 5.2MHz are compared. Imaging with 4 spots in parallel quadruples the effective speed, enabling depth scan rates as high as 20.8 million lines per second. Each setup provides at least 98dB sensitivity and approximately 10microm resolution in tissue. High quality 2D and 3D imaging of biological samples is demonstrated at full scan speed. A discussion about how to best specify OCT imaging speed is included. The connection between voxel rate, line rate, frame rate and hardware performance of the OCT setup such as sample rate, analog bandwidth, coherence length, acquisition dead-time and scanner duty cycle is provided. Finally, suitable averaging protocols to further increase image quality are discussed.
We provide an overview of both traditional and innovative control tools for management of three
Xylosandrus
ambrosia beetles (Coleoptera: Curculionidae: Scolytinae), invasive species with a history ...of damage in forests, nurseries, orchards and urban areas.
Xylosandrus compactus
,
X. crassiusculus
and
X. germanus
are native to Asia, and currently established in several countries around the globe. Adult females bore galleries into the plant xylem inoculating mutualistic ambrosia fungi that serve as food source for the developing progeny. Tunneling activity results in chewed wood extrusion from entry holes, sap outflow, foliage wilting followed by canopy dieback, and branch and trunk necrosis. Maintaining plant health by reducing physiological stress is the first recommendation for long-term control. Baited traps, ethanol-treated bolts, trap logs and trap trees of selected species can be used to monitor
Xylosandrus
species. Conventional pest control methods are mostly ineffective against
Xylosandrus
beetles because of the pests’ broad host range and rapid spread. Due to challenges with conventional control, more innovative control approaches are being tested, such as the optimization of the push–pull strategy based on specific attractant and repellent combinations, or the use of insecticide-treated netting. Biological control based on the release of entomopathogenic and mycoparasitic fungi, as well as the use of antagonistic bacteria, has yielded promising results. However, these technologies still require validation in real field conditions. Overall, we suggest that management efforts should primarily focus on reducing plant stress and potentially be combined with a multi-faceted approach for controlling
Xylosandrus
damage.
PDF
