298 research outputs found
Seasonal Initial Concentrations and In-Field Decay Rates of \u3ci\u3eEscherichia coli\u3c/i\u3e and Bovine \u3ci\u3eBacteroidetes\u3c/i\u3e in Beef Cattle Manure
Eight naturally deposited beef cow manure patties were sampled during summer (July 19 to August 9, 2010), fall (October 26 to November 19, 2010), winter (January 14 to February 18, 2011), and spring (May 5-27, 2011) to determine whether hypothesized seasonal differences existed in the initial concentrations and decay rates of Escherichia coli (E. coli) and bovine Bacteroidetes (BoBac). E. coli concentrations were estimated as culturable colony forming units (CFU) and with a quantitative polymerase chain reaction (qPCR) assay targeting the 23S ribosomal gene. BoBac was quantified with a qPCR assay targeting a 16S ribosomal gene sequence associated with cattle manure.
Initial concentrations for culturable E. coli varied several orders of magnitude during each season, but were significantly lower when the animals grazed fresh forage (3.6 and 4.3 log10CFU/g-dry-manure in fall and spring, respectively) versus receiving hay and grain because of dormant pastures (6.4 log10CFU/g-dry-manure in winter). Average initial E. coli 23S gene abundance was also highly variable but lower in the spring and fall (7.1 and 8.5 log10copies/g-dry-manure) than in the winter (9.4 log10copies/g-dry-manure). Average initial BoBac 16S gene abundance was much less variable but again lower during grazing (9.9 log10copies/g-dry-manure in both spring and fall) versus during supplemental feeding (11.0 and 11.2 log10copies/g-dry-manure in summer and winter, respectively).
Linear regressions of aggregated log transformed concentration data were used to calculate seasonal decay rate coefficients. The decay rate for culturable E. coli was highest in the winter (-0.094 log10CFU/g-dry-manure/day) and significantly lower in the fall and spring (-0.028 and +0.018 log10CFU/g-dry-manure/day, respectively). The same was true for E. coli 23S gene abundance (-0.086, -0.026, and +0.023 log10copies/g-dry-manure/day in winter, fall, and spring, respectively). The decay rates were far higher for BoBac 16S gene abundance which had an opposite seasonal trend, being much higher in the summer (-0.33 log10copies/g-dry-manure/day) than in the winter (-0.10 log10copies/g-dry-manure/day).
The fact that initial bacterial concentrations and decay rates vary seasonally should be considered when modeling the fate and transport of the regulatory fecal pollution indicator E. coli and the fecal pollution source tracking BoBac gene sequence
A BIBLIOMETRIC ANALYSIS OF HEALTH DIPLOMACY RESEARCH BASED ON VOSVIEWER AND CITESPACE
Research on health diplomacy not only deepens global health governance but also enhances the sharing of information and resources in the field of public health. A bibliometric study was conducted on health diplomacy works published between 1993 and 2023 with “health diplomacy”, “medicine diplomacy”, “health and foreign policy”, or “vaccine diplomacy” as the keywords. VOSviewer and CiteSpace were used to perform the bibliometric analysis. A total of 2,216 articles from the Web of Science database were analyzed. Results found that the United States held a prominent and influential position in health diplomacy studies, followed by China, the United Kingdom, and Australia. The London School of Hygiene & Tropical Medicine, the University of Toronto, and Harvard University were the top three research institutes for health diplomacy. The article from Feldbaum et al. (2010) served as the representative and symbolic reference. These findings showed that topics including power, Covid-19, security, soft power, WHO, vaccine diplomacy, and governance, though with shorter spans, were the focal points in recent years. In addition, health diplomacy research exhibited interdisciplinary, cross-cutting, and temporal characteristics closely related to factors such as politics, economics, environment, and public goods
Verification of arbitrary entangled states with homogeneous local measurements
Quantum state verification (QSV) is the task of using local measurements only
to verify that a given quantum device does produce the desired target state. Up
to now, certain types of entangled states can be verified efficiently or even
optimally by QSV. However, given an arbitrary entangled state, how to design
its verification protocol remains an open problem. In this work, we present a
systematic strategy to tackle this problem by considering the locality of what
we initiate as the choice-independent measurement protocols, whose operators
can be directly achieved when they are homogeneous. Taking several typical
entangled states as examples, we demonstrate the explicit procedures of the
protocol design using standard Pauli projections. Moreover, our framework can
be naturally extended to other tasks such as the construction of entanglement
witness, and even parameter estimation.Comment: 6+7 pages, 1 figure; Comments are welcome
Structural and electronic properties of the metal-metal intramolecular junctions of single-walled carbon nanotubes
Several intramolecular junctions (IMJs) connecting two metallic (11, 8) and
(9, 6) carbon nanotubes along their common axis have been realized by using a
layer-divided technique to the nanotubes and introducing the topological
defects. Atomic structure of each IMJ configuration is optimized with a
combination of density-functional theory (DFT) and the universal force field
(UFF) method, based upon which a four-orbital tight-binding calculation is made
on its electronic properties. Different topological defect structures and their
distributions on the IMJ interfaces have been found, showing decisive effects
on the localized density of states, while the sigma-pi coupling effect is
negligible near Fermi energy (EF). Finally, a new IMJ model has been proposed,
which probably reflects a real atomic structure of the M-M IMJ observed in the
experiment [Science 291, 97 (2001)].Comment: 11 pages and 3 figure
A tunable plasmonic refractive index sensor with nanoring-strip graphene arrays
In this paper, a tunable plasmonic refractive index sensor with
nanoring-strip graphene arrays is numerically investigated by the finite
difference time domain (FDTD) method. The simulation results exhibit that by
changing the sensing medium refractive index nmed of the structure, the sensing
range of the system is large. By changing the doping level ng, we noticed that
the transmission characteristics can be adjusted flexibly. The resonance
wavelength remains entirely the same and the transmission dip enhancement over
a big range of incidence angles [0,45] for both TM and TE polarizations, which
indicates that the resonance of the graphene nanoring-strip arrays is
insensitive to angle polarization. The above results are undoubtedly a new way
to realize various tunable plasmon devices, and may have a great application
prospect in biosensing, detection and imaging
Aligning Linguistic Words and Visual Semantic Units for Image Captioning
Image captioning attempts to generate a sentence composed of several
linguistic words, which are used to describe objects, attributes, and
interactions in an image, denoted as visual semantic units in this paper. Based
on this view, we propose to explicitly model the object interactions in
semantics and geometry based on Graph Convolutional Networks (GCNs), and fully
exploit the alignment between linguistic words and visual semantic units for
image captioning. Particularly, we construct a semantic graph and a geometry
graph, where each node corresponds to a visual semantic unit, i.e., an object,
an attribute, or a semantic (geometrical) interaction between two objects.
Accordingly, the semantic (geometrical) context-aware embeddings for each unit
are obtained through the corresponding GCN learning processers. At each time
step, a context gated attention module takes as inputs the embeddings of the
visual semantic units and hierarchically align the current word with these
units by first deciding which type of visual semantic unit (object, attribute,
or interaction) the current word is about, and then finding the most correlated
visual semantic units under this type. Extensive experiments are conducted on
the challenging MS-COCO image captioning dataset, and superior results are
reported when comparing to state-of-the-art approaches.Comment: 8 pages, 5 figures. Accepted by ACM MM 201
- …