Anti-resonance, inhibited coupling and mode transition in depressed core fibers

The depressed core fiber (DCF), consisting of a low-index solid core, a high-index cladding and air surrounding, is in effect a bridge between the conventional step-index fiber and the tube-type hollow-core fiber from the point of view of the index profile. In this paper the dispersion diagram of a DCF is obtained by solving the full-vector eigenvalue equations and analyzed using the theory of anti-resonant and the inhibited coupling mechanisms. While light propagation in tube-type hollow-core fibers is commonly described by the symmetric planar waveguide model, here we propose an asymmetric planar waveguide for the DCFs in an anti-resonant reflecting optical waveguide (ARROW) model. It is found that the anti-resonant core modes in the DCFs have real effective indices, compared to the anti-resonant core modes with complex effective indices in the tube-type hollow-core fibers. The anti-resonant core modes in the DCFs exhibit similar qualitative and quantitative behavior as the core modes in the conventional step-index fibers. The full-vector analytical results for the simple-structure DCFs can contribute to a better understanding of the anti-resonant and inhibited coupling guidance mechanisms in other complex inversed index fibers

Molecular estimation of alteration in intestinal microbial composition in Hashimoto's thyroiditis patients

The gut microbiota has a crucial effect on human health and physiology. Hypothyroid Hashimoto’s thyroiditis (HT) is an autoimmune disorder manifested with environmental and genetic factors. However, it is hypothesized that intestinal microbes might play a vital role in the pathogenesis of HT. The aim of current was to investigate and characterize the gut microbial composition of HT patients both quantitatively and qualitatively. The fecal samples from 29 HT patients and 12 healthy individuals were collected. The PCR-DGGE targeted V3 site of 16S rRNA gene and real time PCR for Bifidobacterium Lactobacillus, Bacteroides vulgatus and Clostridium leptum were performed. Pyrosequencing of 16S rRNA gene with V4 location was performed on 20 randomly selected samples. The comparative analysis of diversity and richness indices revealed diversification of gut microbiota in HT as compared to control. The statistical data elucidate the alterations in phyla of HT patients which was also affirmed at the family level. We observed the declined abundance of Prevotella_9 and Dialister, while elevated genera of the diseased group included Escherichia-Shigella and Parasutterella. The alteration in gut microbial configuration was also monitored at the species level, which showed an increased abundance of E. coli in HT. Therefore, the current study is in agreement with the hypothesis that HT patients have intestinal microbial dysbiosis. The taxa statistics at species-level along with each gut microbial community were modified in HT. Thus, the current study may offer the new insights into the treatment of HT patients, disease pathway, and mechanism

Direct and Relative Effects of the Import Tariff: Estimation Using the Chinese Industrial Level Data

The importing country usually imposes heterogeneous import tariff rates based on the national origins of the products. Reducing the tariff rates on the products from one origin country not only increases the imports from this country, but also decreases the imports from the other trade partners of the importing country. (Direct and relative effects of the import tariff) This paper constructs a variation of the conventional gravity model to analyze the direct and relative effects of the import tariff on international trade flows at the industrial level. Based on our theoretical framework, we compute a new indicator to measure the relative effect and estimate both effects using the Chinese industrial level data. Our empirical findings are consistent with our theoretical predictions: (i) if the tariff rates are reduced towards one origin country, the importing country will import more from this country but reduce the imports from the other origins; (ii) the relative effect is more effective at the industry or country where the importing penetration ratio is relatively high; and (iii) omission of the import penetration ratio will lead to the underestimation of the effects of the multilateral resistance terms on trade performances. Our research contributes to the existing literature by introducing a manipulable method to compute the direct and relative effects of the trade cost at the industrial level, which takes the heterogeneity among industries and countries into accoun

Key lifting : Multi-key Fully Homomorphic Encryption in plain model without noise flooding

Multi-key Fully Homomorphic Encryption (\MK), based on the Learning With Error assumption (\LWE), usually lifts ciphertexts of different users to new ciphertexts under a common public key to enable homomorphic evaluation. The efficiency of the current Multi-key Fully Homomorphic Encryption (\MK) scheme is mainly restricted by two aspects: Expensive ciphertext expansion operation: In a boolean circuit with input length $N$, multiplication depth $L$, security parameter $\lambda$, the number of additional encryptions introduced to achieve ciphertext expansion is $O(N\lambda^6L^4)$. Noise flooding technology resulting in a large modulus $q$ : In order to prove the security of the scheme, the noise flooding technology introduced in the encryption and distributed decryption stages will lead to a huge modulus $q = 2^{O(\lambda L)}B_\chi$, which corrodes the whole scheme and leads to sub-exponential approximation factors $\gamma = \tilde{O}(n\cdot 2^{\sqrt{nL}})$. This paper solves the first problem by presenting a framework called Key-Lifting Multi-key Fully Homomorphic Encryption (\KL). With this \emph{key lifting} procedure, the number of encryptions for a local user is reduced to $O(N)$, similar to single-key fully homomorphic encryption (\FHE). For the second problem, based on R\\u27{e}nyi divergence, we propose an optimized proof method that removes the noise flooding technology in the encryption phase. Additionally, in the distributed decryption phase, we prove that the asymmetric nature of the DGSW ciphertext ensures that the noise after decryption does not leak the noise in the initial ciphertext, as long as the depth of the circuit is sufficient. Thus, our initial ciphertext remains semantically secure even without noise flooding, provided the encryption scheme is leakage-resilient. This approach significantly reduces the size of the modulus $q$ (with $\log q = O(L)$) and the computational overhead of the entire scheme

Direct and Relative Effects of the Import Tariff: Method and Application Using the Industrial Level Data

The importing country usually imposes heterogeneous import tariff rates based on the national origins of the products. Reducing the tariff rates on the products from one origin country not only increases the import flows from this country, but also decreases the import flows from the other trade partners of the importing country. (Direct and relative effects of the import tariff) This paper constructs a variation of the conventional gravity model to analyze the direct and relative effects of the import tariff on international trade flows at the industrial level. Based on our theoretical framework, we compute a new indicator to measure the relative effect and estimate both effects using the Chinese industrial level data. Our empirical findings are consistent with our theoretical predictions: (i) if the tariff rates are reduced towards one origin country, the importing country will import more from this country but reduce the imports from the other origins; (ii) the relative effect is more effective at the industry or country where the importing penetration ratio is relatively high; and (iii) omission of the import penetration ratio will lead to the underestimation of the effects of the multilateral resistance terms on trade performances. Our research contributes to the existing literature by introducing a manipulable method to compute the direct and relative effects of the trade cost at the industrial level, which takes the heterogeneity among industries and countries into account