1,575 research outputs found
Experimental research on evolving rules of segregation ice in artificial frozen soil
AbstractThe foundation of frost heave controlling is the research on evolving rules of segregation ice. The evolving rules of segregation ice have been researched systematically by one-dimension freezing experiments. The technique of dynamic photograph has been applied in research for the first time. The research on segregation ice indicated that three phases can be divided according to the change of temperature field: few segregation ices appeared in the first phases, several thin and discontinuous segregation ices appeared in the second phases, segregation ice evolvement was mainly the growth of final ice lens in the third phase when the freezing front tended to be stable
Measurement-device-independent quantum key distribution over untrustful metropolitan network
Quantum cryptography holds the promise to establish an
information-theoretically secure global network. All field tests of
metropolitan-scale quantum networks to date are based on trusted relays. The
security critically relies on the accountability of the trusted relays, which
will break down if the relay is dishonest or compromised. Here, we construct a
measurement-device-independent quantum key distribution (MDIQKD) network in a
star topology over a 200 square kilometers metropolitan area, which is secure
against untrustful relays and against all detection attacks. In the field test,
our system continuously runs through one week with a secure key rate ten times
larger than previous result. Our results demonstrate that the MDIQKD network,
combining the best of both worlds --- security and practicality, constitutes an
appealing solution to secure metropolitan communications.Comment: 17 pages, 4 figure
Volumes of hippocampal subfields suggest a continuum between schizophrenia, major depressive disorder and bipolar disorder
ObjectiveThere is considerable debate as to whether the continuum of major psychiatric disorders exists and to what extent the boundaries extend. Converging evidence suggests that alterations in hippocampal volume are a common sign in psychiatric disorders; however, there is still no consensus on the nature and extent of hippocampal atrophy in schizophrenia (SZ), major depressive disorder (MDD) and bipolar disorder (BD). The aim of this study was to verify the continuum of SZ – BD – MDD at the level of hippocampal subfield volume and to compare the volume differences in hippocampal subfields in the continuum.MethodsA total of 412 participants (204 SZ, 98 MDD, and 110 BD) underwent 3 T MRI scans, structured clinical interviews, and clinical scales. We segmented the hippocampal subfields with FreeSurfer 7.1.1 and compared subfields volumes across the three diagnostic groups by controlling for age, gender, education, and intracranial volumes.ResultsThe results showed a gradual increase in hippocampal subfield volumes from SZ to MDD to BD. Significant volume differences in the total hippocampus and 13 of 26 hippocampal subfields, including CA1, CA3, CA4, GC-ML-DG, molecular layer and the whole hippocampus, bilaterally, and parasubiculum in the right hemisphere, were observed among diagnostic groups. Medication treatment had the most effect on subfields of MDD compared to SZ and BD. Subfield volumes were negatively correlated with illness duration of MDD. Positive correlations were found between subfield volumes and drug dose in SZ and MDD. There was no significant difference in laterality between diagnostic groups.ConclusionThe pattern of hippocampal volume reduction in SZ, MDD and BD suggests that there may be a continuum of the three disorders at the hippocampal level. The hippocampus represents a phenotype that is distinct from traditional diagnostic strategies. Combined with illness duration and drug intervention, it may better reflect shared pathophysiology and mechanisms across psychiatric disorders
Using crop intercepted solar radiation and vegetation index to estimate dry matter yield of Choy Sum
An accurate assessment of vegetable yield is essential for agricultural production and management. One approach to estimate yield with remote sensing is via vegetation indices, which are selected in a statistical and empirical approach, rather than a mechanistic way. This study aimed to estimate the dry matter of Choy Sum by both a causality-guided intercepted radiation-based model and a spectral reflectance-based model and compare their performance. Moreover, the effect of nitrogen (N) rates on the radiation use efficiency (RUE) of Choy Sum was also evaluated. A 2-year field experiment was conducted with different N rate treatments (0 kg/ha, 25 kg/ha, 50 kg/ha, 100 kg/ha, 150 kg/ha, and 200 kg/ha). At different growth stages, canopy spectra, photosynthetic active radiation, and canopy coverage were measured by RapidScan CS-45, light quantum sensor, and camera, respectively. The results reveal that exponential models best match the connection between dry matter and vegetation indices, with coefficients of determination (R2) all below 0.80 for normalized difference red edge (NDRE), normalized difference vegetation index (NDVI), red edge ratio vegetation index (RERVI), and ratio vegetation index (RVI). In contrast, accumulated intercepted photosynthetic active radiation (Aipar) showed a significant linear correlation with the dry matter of Choy Sum, with root mean square error (RMSE) of 9.4 and R2 values of 0.82, implying that the Aipar-based estimation model performed better than that of spectral-based ones. Moreover, the RUE of Choy Sum was significantly affected by the N rate, with 100 kg N/ha, 150 kg N/ha, and 200 kg N/ha having the highest RUE values. The study demonstrated the potential of Aipar-based models for precisely estimating the dry matter yield of vegetable crops and understanding the effect of N application on dry matter accumulation of Choy Sum
Dealing With Heterogeneous 3D MR Knee Images: A Federated Few-Shot Learning Method With Dual Knowledge Distillation
Federated Learning has gained popularity among medical institutions since it
enables collaborative training between clients (e.g., hospitals) without
aggregating data. However, due to the high cost associated with creating
annotations, especially for large 3D image datasets, clinical institutions do
not have enough supervised data for training locally. Thus, the performance of
the collaborative model is subpar under limited supervision. On the other hand,
large institutions have the resources to compile data repositories with
high-resolution images and labels. Therefore, individual clients can utilize
the knowledge acquired in the public data repositories to mitigate the shortage
of private annotated images. In this paper, we propose a federated few-shot
learning method with dual knowledge distillation. This method allows joint
training with limited annotations across clients without jeopardizing privacy.
The supervised learning of the proposed method extracts features from limited
labeled data in each client, while the unsupervised data is used to distill
both feature and response-based knowledge from a national data repository to
further improve the accuracy of the collaborative model and reduce the
communication cost. Extensive evaluations are conducted on 3D magnetic
resonance knee images from a private clinical dataset. Our proposed method
shows superior performance and less training time than other semi-supervised
federated learning methods. Codes and additional visualization results are
available at https://github.com/hexiaoxiao-cs/fedml-knee
Structured Light Modal Interface via Liquid-Crystal Planar Optics
Recent advances in planar optics with geometric-phase superstructures have
brought a new paradigm in the control of structured light and, in particular,
has substantially enhanced the capabilities of generating and detecting orbital
angular momentum (OAM) states of light and associated spatial modes. However,
the structured modal interface that can reciprocally link OAM states via
adiabatic control and access-associated higher-order geometric phase remains
absent in planar optics. In this work, we propose and experimentally
demonstrate a planar optical astigmatic retarder fabricated with liquid-crystal
(LC) geometric phase. The LC superstructure was designed with the principle of
fractional Fourier transformation and is capable of reciprocal conversion
between all possible OAM states on the same modal sphere. Such a planar device
paves the way towards an easily deployed modal interface of paraxial OAM
states, unlocks the resource of higher-order geometric phase, and has promising
applications in high-dimensional classical/quantum information
Effect of compounds on the purification and antibody preparation of the extracellular domain fragment of the receptor CD163
<p>Abstract</p> <p>Background</p> <p>Porcine reproductive and respiratory syndrome virus (PRRSV) has been acknowledged as one of the most important agents affecting swine. The scavenger receptor CD163 is one of the important entry mediators for PRRSV.</p> <p>Results</p> <p>The tD4 and tD5 CD163 genes were amplified, and the PCR products were cloned into pET-28a(+) (designated pET-28a-tD4 and pET-28a-tD5, respectively). The plasmids pET-28a-tD4 and pET-28a-tD5 were then transformed into the <it>E. coli </it>BL21 (DE3) strain and expressed by adding 1 mmol/L of isopropyl-beta-D-thiogalactopyranoside. The proteins were highly expressed in the supernatant from the tD4- and tD5-producing cells that were incubated with a binding buffer containing the following compounds: β-mercaptoethanol, urea, Tween 20, glycerol, and SDS, while they were rarely expressed in the supernatant from the tD4- and tD5-producing cells that were incubated with binding buffer without the compounds. The tD4 and tD5 proteins were purified, and BALB/c mice were immunized with the purified proteins. Western blotting analysis showed that the tD4 and tD5 proteins were capable of reacting with tD5 antibodies; the titer of both the tD4 and tD5 antiserums was 1:160 against the tD5 protein, as shown by ELISA.</p> <p>Conclusions</p> <p>These studies provide a new way for the purification of proteins expressed in inclusion bodies and the preparation of the corresponding antibodies.</p
The role of 245 phase in alkaline iron selenide superconductors revealed by high pressure studies
Here we show that a pressure of about 8 GPa suppresses both the vacancy order
and the insulating phase, and a further increase of the pressure to about 18
GPa induces a second transition or crossover. No superconductivity has been
found in compressed insulating 245 phase. The metallic phase in the
intermediate pressure range has a distinct behavior in the transport property,
which is also observed in the superconducting sample. We interpret this
intermediate metal as an orbital selective Mott phase (OSMP). Our results
suggest that the OSMP provides the physical pathway connecting the insulating
and superconducting phases of these iron selenide materials.Comment: 32 pages, 4 figure
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