157 research outputs found
Ecotourism, past, current and future perspectives : a bibliometric review between 2001 to 2018
Abstract: Ecotourism is natural based travel that conserves the environment, sustains the well-being of the local communities, and involves environmental interpretation and education. A number of literature reviews have been published focusing on specific aspects of the ecotourism market segmentation, ecological impacts of wildlife viewing, and community-based ecotourism, but there has been minimal attention to critical areas such as quality control, the industry, external environments or institutions. In order to further promote related studies, it is important to conduct a comprehensive review on ecotourism so that recent research progresses can be summarized and future research directions can be identified. Accordungly, this paper aims to conduct a bibliometric review on ecotourism to glean the past, current and future perspectives on ecotourism. Based on 1,889 articles published from 2001 to 2018 and searched from Web of Science, a systematic method combining bibliometric analysis and network analysis is applied to uncover the dynamic trends, academic collaboration and research hotspots. Results show that the overall publication quantity had been gradually improved. The key journals include Journal of Hospitality and Tourism Management, Annals of Tourism Research, Conservation Biology and Biological Conservation. Authors from USA have the most publications and international co-authorships, followed by Australia and England, while the most influential institution is the Chinese Academy of Science followed by Griffith University. Moreover, research keywords have been identified, including ecotourism, management, biodiversity, national park, sustainability and sustainable tourism. In order to further improve research in this field, it is crucial to combine different methods so that more innovative perspectives can be presented. Research findings from this study will provide limitations, and suggestions for future research
Direct imaging of a zero-field target skyrmion and its polarity switch in a chiral magnetic nanodisk
A target skyrmion is a flux-closed spin texture that has two-fold degeneracy
and is promising as a binary state in next generation universal memories.
Although its formation in nanopatterned chiral magnets has been predicted, its
observation has remained challenging. Here, we use off-axis electron holography
to record images of target skyrmions in a 160-nm-diameter nanodisk of the
chiral magnet FeGe. We compare experimental measurements with numerical
simulations, demonstrate switching between two stable degenerate target
skyrmion ground states that have opposite polarities and rotation senses and
discuss the observed switching mechanism.Comment: 18 pages, 4 figure
Retrieval-augmented GPT-3.5-based Text-to-SQL Framework with Sample-aware Prompting and Dynamic Revision Chain
Text-to-SQL aims at generating SQL queries for the given natural language
questions and thus helping users to query databases. Prompt learning with large
language models (LLMs) has emerged as a recent approach, which designs prompts
to lead LLMs to understand the input question and generate the corresponding
SQL. However, it faces challenges with strict SQL syntax requirements. Existing
work prompts the LLMs with a list of demonstration examples (i.e. question-SQL
pairs) to generate SQL, but the fixed prompts can hardly handle the scenario
where the semantic gap between the retrieved demonstration and the input
question is large. In this paper, we propose a retrieval-augmented prompting
method for a LLM-based Text-to-SQL framework, involving sample-aware prompting
and a dynamic revision chain. Our approach incorporates sample-aware
demonstrations, which include the composition of SQL operators and fine-grained
information related to the given question. To retrieve questions sharing
similar intents with input questions, we propose two strategies for assisting
retrieval. Firstly, we leverage LLMs to simplify the original questions,
unifying the syntax and thereby clarifying the users' intentions. To generate
executable and accurate SQLs without human intervention, we design a dynamic
revision chain which iteratively adapts fine-grained feedback from the
previously generated SQL. Experimental results on three Text-to-SQL benchmarks
demonstrate the superiority of our method over strong baseline models
DNA self-assembly nanoflower reverse P-glycoprotein mediated drug resistance in chronic myelogenous leukemia therapy
Introduction: Chronic myelogenous leukemia (CML) is a clonal myeloproliferative disorder caused by the BCR-ABL chimeric tyrosine kinase. Vincristine (VCR) is widely used in leukemia therapy but is hindered by multidrug resistance (MDR).Methods: We prepared DNA nanoflower via self-assembly for the delivery of VCR and P-glycoprotein small interfering RNA (P-gp siRNA).Results and Discussion: The as-prepared nanoflower had a floriform shape with high loading efficiency of VCR (80%). Furthermore, the nanoflower could deliver VCR and P-gp siRNA into MDR CML cells and induce potent cytotoxicity both in vitro and in vivo, thus overcoming MDR of CML. Overall, this nanoflower is a promising tool for resistant CML therapy
Experimental observation of magnetic bobbers for a new concept of magnetic solid-state memory
The use of chiral skyrmions, which are nanoscale vortex-like spin textures,
as movable data bit carriers forms the basis of a recently proposed concept for
magnetic solid-state memory. In this concept, skyrmions are considered to be
unique localized spin textures, which are used to encode data through the
quantization of different distances between identical skyrmions on a guiding
nanostripe. However, the conservation of distances between highly mobile and
interacting skyrmions is difficult to implement in practice. Here, we report
the direct observation of another type of theoretically-predicted localized
magnetic state, which is referred to as a chiral bobber (ChB), using
quantitative off-axis electron holography. We show that ChBs can coexist
together with skyrmions. Our results suggest a novel approach for data
encoding, whereby a stream of binary data representing a sequence of ones and
zeros can be encoded via a sequence of skyrmions and bobbers. The need to
maintain defined distances between data bit carriers is then not required. The
proposed concept of data encoding promises to expedite the realization of a new
generation of magnetic solid-state memory
Effects of the stem extracts of Schisandra glaucescens Diels on collagen-induced arthritis in Balb/c mice
Ethnopharmacological relevance
Schisandra glaucescens Diels (SGD) is used in a subclass of traditional Chinese medicine known as “Tujia drugs”. It has been long used for the treatment of rheumatoid arthritis (RA), cough with dyspnea, spontaneous sweating, night sweating, chronic diarrhea, and neurasthenia. As a woody liana growing in mountain jungles at the altitudes of 750–1800 m, it is mainly distributed in Sichuan and Hubei Provinces of China.
Aim of the study
To evaluate the antiarthritic activity of acetate (EA) and n-butanol (Bu) fractions of SGD extract on a collagen-induced arthritis mice model.
Materials and methods
Acute toxicity of EA and Bu fractions of SGD extract was evaluated by gavage on normal mice. Pharmacological investigations were conducted on arthritis male Balb/c mice. The animal model was induced by immunization with type II bovine collagen (CII) on the 1st and the 14th day of the experimental schedule. EA fraction (104, 312, 936 mg/kg), Bu fraction (156, 469, 1407 mg/kg) of SGD extract was orally administered every two days since the 15th day for 3 weeks. Progression of edema in the paws was measured using a vernier caliper every 3 days since the 10th day. At the end of the experiment, the spleen index and histological changes of the hind knee joints were investigated. Additionally, to explore the possible antirheumatic mechanisms of the EA and Bu fractions, ELISA was carried out to analyze TNF-α, IL-10, IL-6 and IL-1β in the serum.
Results
The half lethal doses of both EA and Bu fractions were much higher than the dose administered in the pharmacological investigations. Oral administration of EA fraction and Bu fraction of SGD extract significantly and does-dependently inhibited type ІІ collagen induced arthritis (CIA) in mice, as indicated by the effects on paws swelling and spleen index. Histopathological examinations demonstrated that SGD effectively protected the bones and cartilages of knee joints from erosion, lesion and deformation. Besides, the serum concentrations of cytokines TNF-α, IL-1β and IL-6 were significantly lower than the ones from the vehicle control group. Respectively, while cytokine IL-10 was remarkably higher compare with the vehicle control group.
Conclusions
SGD might be a safe and effective candidate for the treatment of RA, and deserves further investigation on the chemical components in both EA and Bu fractions of SGD extract
GraphFind: enhancing graph searching by low support data mining techniques
<p>Abstract</p> <p>Background</p> <p>Biomedical and chemical databases are large and rapidly growing in size. Graphs naturally model such kinds of data. To fully exploit the wealth of information in these graph databases, a key role is played by systems that search for all exact or approximate occurrences of a query graph. To deal efficiently with graph searching, advanced methods for indexing, representation and matching of graphs have been proposed.</p> <p>Results</p> <p>This paper presents GraphFind. The system implements efficient graph searching algorithms together with advanced filtering techniques that allow approximate search. It allows users to select candidate subgraphs rather than entire graphs. It implements an effective data storage based also on low-support data mining.</p> <p>Conclusions</p> <p>GraphFind is compared with Frowns, GraphGrep and gIndex. Experiments show that GraphFind outperforms the compared systems on a very large collection of small graphs. The proposed low-support mining technique which applies to any searching system also allows a significant index space reduction.</p
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