27 research outputs found
Long Short-Term Memory Spatial Transformer Network
Spatial transformer network has been used in a layered form in conjunction
with a convolutional network to enable the model to transform data spatially.
In this paper, we propose a combined spatial transformer network (STN) and a
Long Short-Term Memory network (LSTM) to classify digits in sequences formed by
MINST elements. This LSTM-STN model has a top-down attention mechanism profit
from LSTM layer, so that the STN layer can perform short-term independent
elements for the statement in the process of spatial transformation, thus
avoiding the distortion that may be caused when the entire sequence is
spatially transformed. It also avoids the influence of this distortion on the
subsequent classification process using convolutional neural networks and
achieves a single digit error of 1.6\% compared with 2.2\% of Convolutional
Neural Network with STN layer
ATP-responsive DNA-graphene hybrid nanoaggregates for anticancer drug delivery
Stimuli-triggered drug delivery systems are primarily focused on the applications of the tumor microenvironmental or cellular physiological cues to enhance the release of drugs at the target site. In this study, we applied adenosine-5′-triphosphate (ATP), the primary “energy molecule”, as a trigger for enhanced release of preloaded drugs responding to the intracellular ATP concentration that is significantly higher than the extracellular level. A new ATP-responsive anticancer drug delivery strategy utilizing DNA-graphene crosslinked hybrid nanoaggregates as carriers was developed for controlled release of doxorubicin (DOX), which consists of graphene oxide (GO), two single-stranded DNA (ssDNA, denoted as DNA1 and DNA2) and ATP aptamer. The single-stranded DNA1 and DNA2 together with the ATP aptamer serve as the linkers upon hybridization for controlled assembly of the DNA-GO nanoaggregates, which effectively inhibited the release of DOX from the GO nanosheets. In the presence of ATP, the responsive formation of the ATP/ATP aptamer complex causes the dissociation of the aggregates, which promoted the release of DOX in the environment with a high ATP concentration such as cytosol compared with that in the ATP-deficient extracellular fluid. This supports the development of a novel ATP-responsive platform for targeted on-demand delivery of anticancer drugs inside specific cells
Cocoon-Like Self-Degradable DNA Nanoclew for Anticancer Drug Delivery
A bioinspired cocoon-like anticancer drug delivery system consisting of a deoxyribonuclease (DNase)-degradable DNA nanoclew (NCl) embedded with an acid-responsive DNase I nanocapsule (NCa) was developed for targeted cancer treatment. The NCl was assembled from a long-chain single-stranded DNA synthesized by rolling-circle amplification (RCA). Multiple GC-pair sequences were integrated into the NCl for enhanced loading capacity of the anticancer drug doxorubicin (DOX). Meanwhile, negatively charged DNase I was encapsulated in a positively charged acid-degradable polymeric nanogel to facilitate decoration of DNase I into the NCl by electrostatic interactions. In an acidic environment, the activity of DNase I was activated through the acid-triggered shedding of the polymeric shell of the NCa, resulting in the cocoon-like self-degradation of the NCl and promoting the release of DOX for enhanced therapeutic efficacy
A Comprehensive Framework for Comparing Textbooks: Insights from the Literature and Experts
Textbooks are essential components in the learning process. They assist in achieving educational learning outcomes and developing social and cultural values. However, limited studies provide comprehensive frameworks for comparing textbooks. Most have focused on a specific textbook perspective within a particular discipline. Therefore, this study used a triangulation method to develop a comprehensive framework for textbook comparison. Through a systematic literature review and a two-round Fuzzy Delphi method with 155 textbook experts, a textbook comparison framework with four indicators (structure, content, expectations, and language) was developed. Additionally, some of the developed framework indicators and sub-indicators could be relevant for comparing textbooks in a particular discipline. For example, the page count sub-indicator was proven to be useful for comparing humanities and social science textbooks but not natural science textbooks. The findings of this study could facilitate the process of comparing textbooks, hence promoting the understanding of knowledge design and acquisition in different contexts, such as when comparing textbooks from different countries
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed
Analysis of sex and age differences in performance of young Canadian freestyle swimmers
This study is intended to determine sex and age differences in young Canadian freestyle swimmers aged from ≤10 to 18, for all 6 distances from 50m to 1500m in both short and long course indoor pools. The data set used in the studies is publicly available and categorized into sex/age/course/distance groups during seasons from 2008 to 2019. The sex differences in swimming speed were determined using independent Z-tests (two-sided, unequal SD). The age differences in swimming speed over all ages were analysed using classic one-way ANOVA with subsequent pairwise Tukey-HSD post-hoc tests and Welch’s ANOVA followed by pairwise Games-Howell post-hoc tests. They were then determined using paired two-sample t-tests (two-sided). Young male swimmers outperformed young female swimmers in most groups. Groups with similar performances or no significant differences were in younger age groups (10-year and 11-year). Sex differences increased as age increased, ranging from −0.96% to 13.54%. Sex differences in shorter distances and short course were smaller than in longer distances and long course for ≤12 years and became greater than in longer distances at ≥13 years. Age speed differences decreased as age increased until 17–18-years old, ranging from 12.79% to −0.37%. The performance of female swimmers became stable earlier than that of male swimmers. The age-to-age speed differences of male swimmers were greater than those of female swimmers. These gaps increased from 10–11-year to 13–14-year groups and decreased after that. Age differences in shorter distances and short course were greater than in longer distances and long course. Further studies are required to confirm and extend this research to swimmers at other age groups, in other strokes, and from other countries
Equity impacts of the built environment in urban rail transit station areas from a transit-oriented development perspective: a systematic review
Over the past three decades, Transit-Oriented Development (TOD), with transit as its central tenet, has emerged as a pivotal urban policy driving sustainable and intelligent urban growth, drawing significant attention from researchers and practitioners worldwide. TOD involves creating high-density, mixed-use, pedestrian-friendly urban areas around transit stations to enhance transit accessibility, promote social cohesion, and improve housing conditions. However, the global implementation of TOD has encountered challenges across various domains including transportation, housing, and employment, thereby exacerbating inequities within the built environment. This study adopts a TOD perspective to comprehensively review the equity impacts of urban rail transit (URT) station areas on the built environment, with a particular focus on social, travel, perception, health, and spatial dimensions, and their impacts on promoting or hindering equitable outcomes among diverse societal groups. Utilizing a scoping review methodology, the study encapsulates the progress and themes in the field, employing a systematic approach to meticulously analyze the outcomes of each research theme. The findings reveal that URT station areas have positive impacts on economic growth and property values. However, they can also contribute to gentrification, exacerbating disparities between different societal groups in station and non-station areas, along with an unequal distribution of resources and opportunities. Additionally, while these station areas encourage pedestrian activity and public transportation usage, they also carry the potential for environmental pollution, raising concerns about spatial accessibility and facility convenience, thereby impacting environmental equity. This study employs comprehensive and critical theoretical analyses, utilizing intricate methods and detailed indicators, to elucidate disparities in equity outcomes of URT station areas across different societal groups. The crucial challenge in future research lies in integrating the concept of equity into TOD planning strategies. This study aims to provide standardized and harmonized criteria for guiding equitable TOD planning policies, thereby enhancing the scientific basis and effectiveness of planning strategies. Ultimately, it seeks to offer theoretical insights towards the creation of a more equitable and inclusive urban built environment in the future
Exploring Group Movement Pattern through Cellular Data: A Case Study of Tourists in Hainan
Identifying group movement patterns of crowds and understanding group behaviors are valuable for urban planners, especially when the groups are special such as tourist groups. In this paper, we present a framework to discover tourist groups and investigate the tourist behaviors using mobile phone call detail records (CDRs). Unlike GPS data, CDRs are relatively poor in spatial resolution with low sampling rates, which makes it a big challenge to identify group members from thousands of tourists. Moreover, since touristic trips are not on a regular basis, no historical data of the specific group can be used to reduce the uncertainty of trajectories. To address such challenges, we propose a method called group movement pattern mining based on similarity (GMPMS) to discover tourist groups. To avoid large amounts of trajectory similarity measurements, snapshots of the trajectories are firstly generated to extract candidate groups containing co-occurring tourists. Then, considering that different groups may follow the same itineraries, additional traveling behavioral features are defined to identify the group members. Finally, with Hainan province as an example, we provide a number of interesting insights of travel behaviors of group tours as well as individual tours, which will be helpful for tourism planning and management
Morphing Wing Based on Trigonal Bipyramidal Tensegrity Structure and Parallel Mechanism
The development of morphing wings is in the pursuit of lighter weight, higher stiffness and strength, and better flexible morphing ability. A structure that can be used as both the bearing structure and the morphing mechanism is the optimal choice for the morphing wing. A morphing wing composed of a tensegrity structure and a non-overconstrained parallel mechanism was designed. The self-balancing trigonal bipyramidal tensegrity structure was designed based on the shape-finding method and force-equilibrium equation of nodes. The 4SPS-RS parallel mechanism that can complete wing morphing was designed based on the configuration synthesis method. The degree of freedom and inverse solution of the parallel mechanism was obtained based on the screw theory, and the Jacobian matrix of the parallel mechanism was established. The stiffness model of the tensegrity structure and the 4SPS-RS parallel mechanism was established. The relationship between the deformation of the 4SPS-RS parallel mechanism and sweep angle, torsion angle, spanwise bending, and span was obtained. Through the modular assembly and distributed drive, the morphing wing could perform smooth and continuous morphing locally and globally. In the static state, it has the advantages of high stiffness and large bearing capacity. In the process of morphing, it can complete morphing motion with four degrees of freedom in changing sweep, twist, spanwise bending, and span of the wing