125 research outputs found
Bringing power and progress to Africa in a financially and environmentally sustainable manner
EXECUTIVE SUMMARY:
The future of electricity supply and delivery on the continent of Africa represents one of the thorniest
challenges facing professionals in the global energy, economics, finance, environmental, and
philanthropic communities.
Roughly 600 million people in Africa lack any access to electricity. If this deficiency is not solved,
extreme poverty for many Africans is virtually assured for the foreseeable future, as it is widely
recognized that economic advancement cannot be achieved in the 21st Century without good electricity
supply. Yet, if Africa were to electrify in the same manner pursued in developed economies around the
world during the 20th Century, the planet’s global carbon budget would be vastly exceeded, greatly
exacerbating the worldwide damages from climate change.
Moreover, due to low purchasing power in most African economies and fiscal insolvency of most African
utilities, it is unclear exactly how the necessary infrastructure investments can be deployed to bring
ample quantities of power – especially zero-carbon power – to all Africans, both those who currently are
unconnected to any grid as well as those who are now served by expensive, high-emitting, limited and
unreliable electricity supply.
With the current population of 1.3 billion people expected to double by 2050, the above-noted
challenges associated with the African electricity sector may well get substantially worse than they
already are – unless new approaches to infrastructure planning, development, finance and operation
can be mobilized and propagated across the continent.
This paper presents a summary of the present state and possible futures for the African electricity
sector. A synthesis of an ever-growing body of research on electricity in Africa, this paper aims to
provide the reader a thorough and balanced context as well as general conclusions and
recommendations to better inform and guide decision-making and action. [TRUNCATED]This paper was developed as part of a broader initiative
undertaken by the Institute for Sustainable Energy (ISE) at
Boston University to explore the future of the global
electricity industry.
This ISE initiative – a collaboration with the Global Energy
Interconnection and Development Cooperation Organization
(GEIDCO) of China and the Center for Global Energy Policy
within the School of International and Public Affairs at
Columbia University – was generously enabled by a grant
from Bloomberg Philanthropies.
The authors gratefully acknowledge the support and
contributions of the above funders and partners in this
research
Empirical Study About the Motivations for Using Multifunctional Social Media: Based upon the Uses and Gratifications Theory
Social media is a kind of online platform which used by people to share contents and contact each other via virtual communities and networks. With the development of information technology, it becomes neoteric and multifunctional. In order to examine what factors affecting individuals\u27 usage intentions for the various functions of social media, we proposed a model based on the uses and gratifications theory, this theory indicates there are three types of motivations, named as social motivation, utilitarian motivation and hedonic motivation, then six factors derived from the three motivations are presented. We collected 404 samples from the QQ users from 77 cities in China, with statistical analysis, the result shows that four of them can significantly affect individuals\u27 usage intentions of QQ\u27 various functions beyond as an instant messenger. This study extends current understanding about the usage motivations of social media and it can be a reference for future research in this field
Constructing a Computer Model of the Human Eye Based on Tissue Slice Images
Computer simulation of the biomechanical and biological heat transfer in ophthalmology greatly relies on having a reliable computer model of the human eye. This paper proposes a novel method on the construction of a geometric model of the human eye based on tissue slice images. Slice images were obtained from an in vitro Chinese human eye through an embryo specimen processing methods. A level set algorithm was used to extract contour points of eye tissues while a principle component analysis was used to detect the central axis of the image. The two-dimensional contour was rotated around the central axis to obtain a three-dimensional model of the human eye. Refined geometric models of the cornea, sclera, iris, lens, vitreous, and other eye tissues were then constructed with their position and ratio relationships kept intact. A preliminary study of eye tissue deformation in eye virtual surgery was simulated by a mass-spring model based on the computer models developed
LiCamGait: Gait Recognition in the Wild by Using LiDAR and Camera Multi-modal Visual Sensors
LiDAR can capture accurate depth information in large-scale scenarios without
the effect of light conditions, and the captured point cloud contains
gait-related 3D geometric properties and dynamic motion characteristics. We
make the first attempt to leverage LiDAR to remedy the limitation of
view-dependent and light-sensitive camera for more robust and accurate gait
recognition. In this paper, we propose a LiDAR-camera-based gait recognition
method with an effective multi-modal feature fusion strategy, which fully
exploits advantages of both point clouds and images. In particular, we propose
a new in-the-wild gait dataset, LiCamGait, involving multi-modal visual data
and diverse 2D/3D representations. Our method achieves state-of-the-art
performance on the new dataset. Code and dataset will be released when this
paper is published
The Critical Role of Public Charging Infrastructure
Editors: Peter Fox-Penner, PhD, Z. Justin Ren, PhD, David O. JermainA decade after the launch of the contemporary global electric vehicle (EV) market, most cities face a major challenge preparing for rising EV demand. Some cities, and the leaders who shape them, are meeting and even leading demand for EV infrastructure. This book aggregates deep, groundbreaking research in the areas of urban EV deployment for city managers, private developers, urban planners, and utilities who want to understand and lead change
Bridging childhood to adulthood: the impact of early life stress on acute stress responses
BackgroundChildhood trauma exerts enduring impacts on the physical and psychological well-being of individuals in adulthood, influencing their daily functioning. This study aims to investigate the impact of childhood trauma on stress recovery in adults, concentrating on heart rate variations during acute stress exposure.MethodsA cohort of 126 participants completed the Childhood Trauma Questionnaire (CTQ) and underwent the Trier Social Stress Test (TSST) to elicit acute stress, with continuous heart rate (HR) monitoring for stress recovery assessment.ResultsThe results revealed a negative correlation between childhood trauma and stress recovery, prominently observed in instances of emotional neglect and abuse. Individuals with heightened childhood trauma exhibited protracted stress recovery following acute stress exposure.ConclusionChildhood traumatic experiences were associated with the recovery from acute stress, as indicated by heart rate indices. These findings contribute to the foundational framework for psychological interventions tailored to individuals with a history of childhood trauma
Accurate Determination of Aldehydes, Ketones and Furans in Non-grape Wines by Headspace-Solid-Phase Microextraction Combined with High-Resolution Gas Chromatography-Orbitrap Mass Spectrometry
In this study, headspace-solid-phase microextraction extraction combined with gas chromatography-orbitrap-mass spectrometry (HS-SPME-GC-Orbitrap-MS) was used to establish a method for the simultaneous determination of five aldehydes and ketones and four furans in fruit wines. The method was validated on model wine, goji berry wine, blueberry wine and hawthorn wine. The limits of detection (LODs) for all target compounds ranged from 0.004 to 6.300 μg/L, and the limits of quantification (LOQs) were between 0.01 and 21.00 μg/L. The recoveries of all analytes in spiked wine samples were between 81% and 120% and the relative standard deviations (RSDs) for precision were equal to or less than 19.08%. This method is accurate and can meet the requirements for the quantification of aldehydes, ketones and furans in fruit wines
Analysis of Major Aroma Compounds in Fermented and Prepared Hawthorn Wine
In this study, liquid-liquid extraction-solvent assisted flavor evaporation (LLE-SAFE), headspace solid phase microextraction extraction (HS-SPME), gas chromatography-quadrupole-mass spectrometry (GC-Quadrupole-MS), gas chromatography-orbitrap-mass spectrometry (GC-Orbitrap-MS) and gas chromatography-olfactometry (GC-O) were used in combination to identify the volatile components in a fermented hawthorn wine (SBL-J) and a prepared hawthorn wine (FS), and the results of sensory analysis, modified frequency (MF) and odor activity value (OAV) were used to determine the key aroma compounds. Totally 89 aroma compounds were identified by LLE-SAFE/GC-O-MS. In addition, 29 and 38 aroma compounds with MF values of more than 20% were found in SBL-J and FS, respectively. A total of 123 volatile components were detected by HS-SPME/GC-Quadrupole-MS and HS-SPME/GC-Orbitrap-MS and there were 29 and 33 aroma compounds with OAV of greater than 1 (0.1 for esters) identified in SBL-J and FS, respectively. 2-Methybutyl acetate, ethyl hexanoate, ethyl octanoate and phenylethyl alcohol were the key aroma compounds in the two samples. To our knowledge, 2-methybutyl acetate, ethyl isovalerate, (E,E)-2,4-hexadienoic acid ethyl ester and ethyl butyrate, were identified for the first time as the key aroma components of hawthorn wine
p63: a crucial player in epithelial stemness regulation
epithelial tissue homeostasis is closely associated with the self-renewal and differentiation behaviors of epithelial stem cells (ESCs). p63, a well-known marker of ESCs, is an indispensable factor for their biological activities during epithelial development. the diversity of p63 isoforms expressed in distinct tissues allows this transcription factor to have a wide array of effects. p63 coordinates the transcription of genes involved in cell survival, stem cell self-renewal, migration, differentiation, and epithelial-to-mesenchymal transition. through the regulation of these biological processes, p63 contributes to, not only normal epithelial development, but also epithelium-derived cancer pathogenesis. In this review, we provide an overview of the role of p63 in epithelial stemness regulation, including self-renewal, differentiation, proliferation, and senescence. we describe the differential expression of TAp63 and ΔNp63 isoforms and their distinct functional activities in normal epithelial tissues and in epithelium-derived tumors. furthermore, we summarize the signaling cascades modulating the TAp63 and ΔNp63 isoforms as well as their downstream pathways in stemness regulation
Comparative genomic analyses of Cutibacterium granulosum provide insights into genomic diversity
Cutibacterium granulosum, a commensal bacterium found on human skin, formerly known as Propionibacterium granulosum, rarely causes infections and is generally considered non-pathogenic. Recent research has revealed the transferability of the multidrug-resistant plasmid pTZC1 between C. granulosum and Cutibacterium acnes, the latter being an opportunistic pathogen in surgical site infections. However, there is a noticeable lack of research on the genome of C. granulosum, and the genetic landscape of this species remains largely uncharted. We investigated the genomic features and evolutionary structure of C. granulosum by analyzing a total of 30 Metagenome-Assembled Genomes (MAGs) and isolate genomes retrieved from public databases, as well as those generated in this study. A pan-genome of 6,077 genes was identified for C. granulosum. Remarkably, the ‘cloud genes’ constituted 62.38% of the pan-genome. Genes associated with mobilome: prophages, transposons [X], defense mechanisms [V] and replication, recombination and repair [L] were enriched in the cloud genome. Phylogenomic analysis revealed two distinct mono-clades, highlighting the genomic diversity of C. granulosum. The genomic diversity was further confirmed by the distribution of Average Nucleotide Identity (ANI) values. The functional profiles analysis of C. granulosum unveiled a wide range of potential Antibiotic Resistance Genes (ARGs) and virulence factors, suggesting its potential tolerance to various environmental challenges. Subtype I-E of the CRISPR-Cas system was the most abundant in these genomes, a feature also detected in C. acnes genomes. Given the widespread distribution of C. granulosum strains within skin microbiome, our findings make a substantial contribution to our broader understanding of the genetic diversity, which may open new avenues for investigating the mechanisms and treatment of conditions such as acne vulgaris
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