447 research outputs found
Statistical Learning for Individualized Asset Allocation
We establish a high-dimensional statistical learning framework for
individualized asset allocation. Our proposed methodology addresses
continuous-action decision-making with a large number of characteristics. We
develop a discretization approach to model the effect of continuous actions and
allow the discretization frequency to be large and diverge with the number of
observations. The value function of continuous-action is estimated using
penalized regression with our proposed generalized penalties that are imposed
on linear transformations of the model coefficients. We show that our proposed
Discretization and Regression with generalized fOlded concaVe penalty on Effect
discontinuity (DROVE) approach enjoys desirable theoretical properties and
allows for statistical inference of the optimal value associated with optimal
decision-making. Empirically, the proposed framework is exercised with the
Health and Retirement Study data in finding individualized optimal asset
allocation. The results show that our individualized optimal strategy improves
the population financial well-being
Antibody responses to lytic and latent human herpesvirus 8 antigens among HIV-infected patients in central China
Human herpesvirus 8 (HHV8) is an important opportunistic infection of HIV/AIDS. However, very little is known about antibody seropositivities to HHV8 lytic and latent antigens among HIVinfected patients in China. Therefore, a cross-sectional study was conducted to explore HHV8 serostatus among 316 HIV-infected patients in a rural area of central China. The antibody seropositivity to HHV8 ORF65 (lytic) and LANA (latent) antigens was 12.7% and 10.4%, respectively. Patients who were naïve to antiretroviral therapy (ART) were more likely to be seropositive for antibodies to ORF65 (OR: 3.79; 95% CI: 1.71–8.42) and LANA (OR: 3.77; 95% CI: 1.55–9.14) than patients receiving ART. Patients having CD4+ cell counts less than 200 cells/mm3 were more likely to be seropositive for LANA antibody (OR: 3.53; 95% CI: 1.44–8.64) and to have lower LANA antibody titer (p = 0.007). They were also more likely to be seropositive for ORF65 antibody (OR: 2.12; 95% CI: 0.94–4.78) and to have a lower ORF65 antibody titer (p = 0.065), though the difference was marginally significant. No associations between other viral coinfections studied and antibody seropositivity to either latent or lytic HHV8 antigens were identified. Study findings suggest that antibody responses to both lytic and latent HHV8 antigens among HIV patients in China were fairly high and were associated with immunodeficiency status and ART
Template-assisted Preparation of Self-standing 2D-MOF Membranes for Application in Cascade Reactions
ANALYSIS OF MULTI-CHANNEL TWO-DIMENSIONAL PROBABILITY CSMA AD HOC NETWORK PROTOCOL BASED THREE-WAY HANDSHAKE MECHANISM
In wireless Ad Hoc networks, large number and flexible mobility of terminals lead to the rarity of wireless channel resources. Also the hidden and exposed terminal problem exists in the Ad Hoc network which is the major factors restricting its development and applying. Considering these factors, this paper proposes a new CSMA protocol: multi-channel two-dimensional probability CSMA for wireless Ad Hoc network protocol based on three-way handshake mechanism, and analyzes the system throughput, delay of information packet, energy consumption and other properties under the control of the proposed protocol. By using the cycle analysis method, computer simulation results not only verify the theoretical analysis, but also show that the protocol has the optimum performance. The proposed protocol can not only reduce the collision probability of information packets to some extent, improving the channel utilization, reducing the waste of channel resources, but also achieve the balancing of load in a variety of wireless Ad Hoc network services, meeting the needs by different priorities with different QoS, and ensuring the systematic efficiency and fairness
Improving retrieval accuracy for aerosol optical depth by fusion of MODIS and CALIOP data
MODIS i CALIOP su dva neovisna promatračka instrumenta u konstelaciji A-train satelita. Obadva daju podatke za optičku dubinu aerosola –AOD (aerosol optical depth) i skeniraju iste točke na površini zemlje unutar intervala od dvije minute. Različitih principa dizajna, MODIS i CALIOP instrumenti daju različite točnosti podataka AOD pod različitim uvjetima. U ovom radu predlažemo pristup dvostepene fuzije, uključujući stadij analize i stadij integracije, kako bi se poboljšala točnost pronalaženja AOD podataka. U stadiju analize sistematski analiziramo uvjete pod kojima se MODIS-om podaci dobro pronalaze dok CALIOP-om ne i obrnuto. U stadiju integracije, kombiniramo AOD podatke obadva instrumenta zajedno koristeći prednosti jednoga da bi se nadomjestili nedostaci drugoga. Ispitujemo pristup fuzije na podacima skupljanim dvije godine uz MODIS, CALIOP i AERONET. Taj rezultat fuzije je znatno točniji od AOD prikupljenih podataka s bilo kojeg pojedinačnog instrumenta za promatranje.MODIS and CALIOP are two independent observation instruments in the A-train satellite constellation. They both provide aerosol optical depth (AOD) retrievals and scan the same points on the Earth’s surface within a two-minute interval. With different design principles, MODIS and CALIOP instruments obtain varying AOD retrieval accuracies under different conditions. In this paper, we propose a two-stage fusion approach, including an analysis stage and an integration stage, to improve AOD retrieval accuracy. In the analysis stage, we systematically analyse conditions where MODIS retrieves well while CALIOP does not, and vice-versa. In the integration stage, we combine AOD retrievals from both instruments together by drawing on the other\u27s strong points to make up one\u27s weak points. We test the fusion approach on the two-year collocated data from MODIS, CALIOP and AERONET. The fusion result is significantly more accurate than AOD retrievals from any single observation facility
Greater chemical signaling in root exudates enhances soil mutualistic associations in invasive plants compared to natives
Invasive plants can change soil properties resulting in improved growth. Although invaders are known to alter soil chemistry, it remains unclear if chemicals secreted by roots facilitate invasive plant–soil mutualisms. With up to 19 confamilial pairs of invasive and native plants, and most of which were congeners, we explored the root exudate-induced changes in plant–arbuscular mycorrhizal (AM) fungal mutualisms. We found that, relative to natives, invaders had greater AM colonization, greater biomass and their root exudates contained higher concentrations of two common chemical signals – quercetin and strigolactones – which are known to stimulate AM fungal growth and root colonization. An exudate exchange experiment showed that root exudates from invaders increased AM colonization more than exudates from natives. However, application of activated carbon led to greater reduction in AM colonization and plant biomass for invaders than natives, suggesting stronger effects of chemical signals in root exudates from invaders. We show that nonnative plants promote interactions with soil mutualists via enhancing root exudate chemicals, which could have important implications for invasion success
The P-persistent CSMA Protocol with Monitoring Function in WSN and the Analysis of the Protocol
This paper presents a new p-persistent CSMA wireless sensor network MAC protocol with monitoring function based on random multiple access system, and gets the mathematical expressions of system throughput, system average operating power and the life cycle of terminal nodes of p-persistent CSMA wireless sensor network MAC protocol with monitoring function through complicated mathematical modeling, rigorous mathematical derivation and using average period analysis. The computer simulation results not only confirm the correctness of the theoretical analysis but also show that the p-persistent CSMA with monitoring for WSNs MAC protocol due to join the monitoring signals, resulting in the decrease of systemic throughput, but reduce the collision probability. Meanwhile, the p-persistent CSMA wireless sensor network MAC protocol with monitoring function this paper presents can effectively reduce energy consumption
A novel PHKA2 variant in a Chinese boy with glycogen storage diseases type IXa
BackgroundGlycogen storage diseases (GSDs) are a group of heterogeneous inherited metabolic disorders with an incidence of 4%–5%. There are 19 types of GSDs, making diagnosis one of the greatest challenges.MethodsThe proband and his parents were referred to our hospital for genetic diagnosis. Ultrasound screening suggested hepatomegaly. A novel insertion variant NM_000292 c.1155_1156insT (p. 386N>*) in PHKA2 gene was identified using trio whole exome sequencing (Trio-WES), which resulted in the codon of amino acid 386 from asparagine to termination (p. 386N>*). The 3D mutant protein structure was predicted using AlphaFold, and the results showed that the truncated PHKA2 protein contained 385 of the 1,235 amino acids of the mature protein.ConclusionWe describe a previously unreported case of a GSDs IXa type Chinese boy caused by a novel PHKA2 variant. This clinical case contributes to the understanding of the characteristics of GSDs type IXa and expands the variants spectrum of genes related to GSDs type IXa. Our findings demonstrated the significance of genetic testing in the diagnosis of GSDs
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