3,633 research outputs found
Organic Food and Agriculture - Ethics
Organic food is produced without the use of synthetic fertilizers and pesticides. Four further exclusions in organic production are: genetically modified organisms (GMOs), irradiation, prophylactic antibiotics, and engineered nanoparticles. These six exclusions differentiate organic agriculture from chemical agriculture. Agriculture and food harvesting and production date back millennia, and until about a century ago that history is de facto organic. The Industrial Revolution ushered in an era of novel production strategies. Agriculture was not immune to new views of industrialization and reductionism. Advances in chemistry enabled some implementation of such views. Early in the diffusion of chemical farming practices, the Austrian mystic Rudolf Steiner (1865–1924) called for a differentiated agriculture free of these new synthetic chemical inputs. The terminology, theory, and practices of biodynamic agriculture evolved (in the 1920s and 1930s) from Steiner’s Agriculture Course of 1924. It was a guided evolution, coordinated by Ehrenfried Pfeiffer (1899–1961) in Switzerland. The UK agriculturist, Lord Northbourne (1896–1982), invited Pfeiffer to lead a conference on biodynamics at his farm in Kent (in 1939). The following year Northbourne published his manifesto of organic farming, “Look to the Land.” In that book, he coined the term “organic farming” and wrote of a contest of “organic versus chemical farming”.The ideas and ideals of organic farming quickly proliferated internationally off the back of Northbourne’s 1940 book. Organic farming is now practiced in at least 179 countries, accounts for 50.9 million agricultural hectares, and a market value of US$ 81.6 billion (€75 billion)
Detection of bearing damage by statistic vibration analysis
The condition of bearings, which are essential components in mechanisms, is crucial to safety. The analysis of the bearing vibration signal, which is always contaminated by certain types of noise, is a very important standard for mechanical condition diagnosis of the bearing and mechanical failure phenomenon. In this paper the method of rolling bearing fault detection by statistical analysis of vibration is proposed to filter out Gaussian noise contained in a raw vibration signal. The results of experiments show that the vibration signal can be significantly enhanced by application of the proposed method. Besides, the proposed method is used to analyse real acoustic signals of a bearing with inner race and outer race faults, respectively. The values of attributes are determined according to the degree of the fault. The results confirm that the periods between the transients, which represent bearing fault characteristics, can be successfully detected
XCAT-GAN for Synthesizing 3D Consistent Labeled Cardiac MR Images on Anatomically Variable XCAT Phantoms
Generative adversarial networks (GANs) have provided promising data
enrichment solutions by synthesizing high-fidelity images. However, generating
large sets of labeled images with new anatomical variations remains unexplored.
We propose a novel method for synthesizing cardiac magnetic resonance (CMR)
images on a population of virtual subjects with a large anatomical variation,
introduced using the 4D eXtended Cardiac and Torso (XCAT) computerized human
phantom. We investigate two conditional image synthesis approaches grounded on
a semantically-consistent mask-guided image generation technique: 4-class and
8-class XCAT-GANs. The 4-class technique relies on only the annotations of the
heart; while the 8-class technique employs a predicted multi-tissue label map
of the heart-surrounding organs and provides better guidance for our
conditional image synthesis. For both techniques, we train our conditional
XCAT-GAN with real images paired with corresponding labels and subsequently at
the inference time, we substitute the labels with the XCAT derived ones.
Therefore, the trained network accurately transfers the tissue-specific
textures to the new label maps. By creating 33 virtual subjects of synthetic
CMR images at the end-diastolic and end-systolic phases, we evaluate the
usefulness of such data in the downstream cardiac cavity segmentation task
under different augmentation strategies. Results demonstrate that even with
only 20% of real images (40 volumes) seen during training, segmentation
performance is retained with the addition of synthetic CMR images. Moreover,
the improvement in utilizing synthetic images for augmenting the real data is
evident through the reduction of Hausdorff distance up to 28% and an increase
in the Dice score up to 5%, indicating a higher similarity to the ground truth
in all dimensions.Comment: Accepted for MICCAI 202
One-stage laparoscopic-assisted resection of gastrojejunocolic fistula after gastrojejunostomy for duodenal ulcer: a case report
<p>Abstract</p> <p>Introduction</p> <p>Gastrojejunocolic fistula is a rare condition after gastrojejunostomy. It was thought to be a late complication related to stomal ulcers as a result of inadequate gastrectomy or incomplete vagotomy. We report a case of gastrojejunocolic fistula after gastrojejunostomy for peptic ulcer treated with one-stage laparoscopic resection.</p> <p>Case presentation</p> <p>A 41-year-old Japanese man complained of diarrhea for 10 months, as well as severe weight loss and weakness. After admission, we immediately started intravenous hyperalimentation. On performing colonoscopy and barium swallow, gastrojejunocolic fistula was observed close to the gastrojejunostomy site leading to the transverse colon. After our patient's nutritional status had improved, one-stage surgical intervention was performed laparoscopically. After the operation, our patient recovered uneventfully and his body weight increased by 5 kg within three months.</p> <p>Conclusions</p> <p>Modern management of gastrojejunocolic fistula is a one-stage resection because of the possibility of early recovery from malnutrition using parenteral nutritional methods. Today, laparoscopic one-stage en bloc resection may be feasible for patients with gastrojejunocolic fistula due to the development of laparoscopic instruments and procedures. We describe the first case of gastrojejunocolic fistula treated laparoscopically by one-stage resection and review the literature.</p
Correlating the nanostructure and electronic properties of InAs nanowires
The electronic properties and nanostructure of InAs nanowires are correlated
by creating multiple field effect transistors (FETs) on nanowires grown to have
low and high defect density segments. 4.2 K carrier mobilities are ~4X larger
in the nominally defect-free segments of the wire. We also find that dark field
optical intensity is correlated with the mobility, suggesting a simple route
for selecting wires with a low defect density. At low temperatures, FETs
fabricated on high defect density segments of InAs nanowires showed transport
properties consistent with single electron charging, even on devices with low
resistance ohmic contacts. The charging energies obtained suggest quantum dot
formation at defects in the wires. These results reinforce the importance of
controlling the defect density in order to produce high quality electrical and
optical devices using InAs nanowires.Comment: Related papers at http://pettagroup.princeton.ed
Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV
The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8 TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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