1,492 research outputs found
Chemical Evolution of Atmospheric Organic Carbon over Multiple Generations of Oxidation
The evolution of atmospheric organic carbon (OC) as it undergoes oxidation has a controlling influence on concentrations of key atmospheric species, including particulate matter, ozone, and oxidants. However, the full characterization of OC over hours to days of atmospheric processing has been stymied by its extreme chemical complexity. Here we study the multigenerational oxidation of -pinene in the laboratory, characterizing products with several state-of-the-art analytical techniques. While quantification of some early-generation products remains elusive, full carbon closure is achieved (within uncertainty) by the end of the experiments. This enables new insights into the effects of oxidation on OC properties (volatility, oxidation state, and reactivity), and the atmospheric lifecycle of OC. Following an initial period characterized by functionalization reactions and particle growth, fragmentation reactions dominate, forming smaller species. After approximately one day of atmospheric aging, most carbon is sequestered in two long-lived reservoirs, volatile oxidized gases and low-volatility particulate matter
Competency-based Education Through Micro-credentials Offerings – A Pilot Study
This pilot study examined the implementation of Competency-Based Education (CBE) through micro-credentials at the Singapore Institute of Technology (SIT), focusing on the perspectives of learners, instructors, and employers. Despite a growing global interest in CBE, empirical research on its effectiveness remains limited. SIT’s Competency-Based Stackable Micro-credential (CSM) program offers modular, industry-relevant learning for working adults, with micro-credentials functioning as standalone qualifications or stackable units toward a full degree. Findings from learner surveys indicated that the content was highly relevant to real-world jobs, and the learning could be applied to work. Instructors recognized the relevance of CBE to industry needs, despite the increased demands associated with content development, delivery, and learner support. Employers observed improvements in employee competencies and workplace engagement. The findings underscore the potential of CBE micro-credentials to offer flexible, industry-focused education pathways when supported by robust frameworks and comprehensive learner support services.
NKG2A Down-Regulation by Dasatinib Enhances Natural Killer Cytotoxicity and Accelerates Effective Treatment Responses in Patients With Chronic Myeloid Leukemia
Chronic myeloid leukemia (CML) is a hematological malignancy characterized by the presence of t(9;22) chromosomal translocation that results in BCR-ABL fusion gene. ABL tyrosine kinase inhibitors (TKIs), such as imatinib, nilotinib, and dasatinib, are currently the front-line treatment options for CML. Recently, natural killer (NK) cell activation and expansion have been shown to be associated with optimal treatment responses for CML. To investigate the effects and mechanisms of these TKIs on NK cells, here we characterized activating and inhibitory NK receptors in CD3−CD16+CD56dim NK cells isolated from CML patients in chronic phase (CP). The expressions of activating NK receptors, such as NKG2D, natural cytotoxicity receptor (NCR) and DNAM-1, rebounded after successful TKI treatments for CML. In contrast, among the three surveyed inhibitory receptors (NKG2A, KIR2DL1, and KIR3DL1), only the expression of NKG2A was reverted and suppressed to a very low level by dasatinib, and not by imatinib or nilotinib. CML patients treated with dasatinib indeed expressed fewer NKG2A+ NK cells, which send negative signals for induction of NK cytotoxicity. For these dasatinib-treated patients, the duration to reach major molecular response (MMR) was shorter, and significantly correlated with individual's NKG2A+ NK cell number. This clinical relevance to NKG2A was not observed in treatments with imatinib or nilotinib. In line with dasatinib-specific down-regulation of NKG2A, NK cytotoxicity evaluated by the killing assay was also significantly higher in patients treated with dasatinib than in those treated with imatinib or nilotinib. The lower NK cytotoxicity from imatinib or nilotinib treatments could be reverted by NKG2A blockade using anti-NKG2A antibody. Further in vitro experiments revealed mechanistically that dasatinib could inactivate p38 mitogen-activated protein kinase (MAPK), and consequently affect nuclear import of GATA-3 and GATA-3 transcriptional activities for NKG2A. Our results highlight the dual effects of dasatinib in direct inhibition of ABL kinase and in immunomodulation through NKG2A down-regulation, contributing to accelerated molecular responses (MR) in CML
Measurements of the pp → ZZ production cross section and the Z → 4ℓ branching fraction, and constraints on anomalous triple gauge couplings at √s = 13 TeV
Four-lepton production in proton-proton collisions, pp -> (Z/gamma*)(Z/gamma*) -> 4l, where l = e or mu, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 35.9 fb(-1). The ZZ production cross section, sigma(pp -> ZZ) = 17.2 +/- 0.5 (stat) +/- 0.7 (syst) +/- 0.4 (theo) +/- 0.4 (lumi) pb, measured using events with two opposite-sign, same-flavor lepton pairs produced in the mass region 60 4l) = 4.83(-0.22)(+0.23) (stat)(-0.29)(+0.32) (syst) +/- 0.08 (theo) +/- 0.12(lumi) x 10(-6) for events with a four-lepton invariant mass in the range 80 4GeV for all opposite-sign, same-flavor lepton pairs. The results agree with standard model predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous ZZZ and ZZ. couplings at 95% confidence level: -0.0012 < f(4)(Z) < 0.0010, -0.0010 < f(5)(Z) < 0.0013, -0.0012 < f(4)(gamma) < 0.0013, -0.0012 < f(5)(gamma) < 0.0013
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Association between Quality of Life and Visual Acuity in a Randomized Clinical Trial of Patients with Uveitis Taking Antimetabolites.
PURPOSE: To evaluate how changes in visual acuity are associated with changes in quality of life (QoL) among patients with non-infectious uveitis taking antimetabolites. METHODS: This secondary analysis of the multicenter First-line Antimetabolites as Steroid-sparing Treatment (FAST) Uveitis Trial involves 216 participants randomized to methotrexate or mycophenolate mofetil. Vision-related (NEI-VFQ and IND-VFQ) and health-related (PCS and MCS SF-36v2) QoL and visual acuity were measured at baseline and 6-month primary endpoint. RESULTS: Visual acuity was significantly associated and correlated with all QoL measures (Spearman correlation coefficients = 0.5, 0.5, 0.3, and 0.4 for NEI-VFQ, IND-VFQ, SF-36v2 MCS and PCS, respectively). All observed changes in QoL met or exceeded the minimal clinically important difference definition on each scale. Treatment group was not significantly associated with any QoL measure. CONCLUSION: By adding insight beyond visual acuity, QoL provides a more comprehensive picture of the patient experience during uveitis treatment.Abbreviations and Acronyms: QoL = quality of life; VR-QoL = vision-related quality of life; HR-QoL = health-related quality of life; FAST = First-line Antimetabolites as Corticosteroid Sparing Treatment; NEI-VFQ = National Eye Institute Visual Functioning Questionnaire; IND-VFQ = Indian Visual Functioning Questionnaire; SF-36v2 = Medical Outcomes Study 36-Item Short Form Survey; PCS = physical component score; MCS = mental component score; 95% CI = 95% confidence interval; MCID = minimal clinically important difference
Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017 : a systematic analysis for the Global Burden of Disease Study 2017
Background: The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk outcome pairs, and new data on risk exposure levels and risk outcome associations.
Methods: We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017.
Findings: In 2017,34.1 million (95% uncertainty interval [UI] 33.3-35.0) deaths and 121 billion (144-1.28) DALYs were attributable to GBD risk factors. Globally, 61.0% (59.6-62.4) of deaths and 48.3% (46.3-50.2) of DALYs were attributed to the GBD 2017 risk factors. When ranked by risk-attributable DALYs, high systolic blood pressure (SBP) was the leading risk factor, accounting for 10.4 million (9.39-11.5) deaths and 218 million (198-237) DALYs, followed by smoking (7.10 million [6.83-7.37] deaths and 182 million [173-193] DALYs), high fasting plasma glucose (6.53 million [5.23-8.23] deaths and 171 million [144-201] DALYs), high body-mass index (BMI; 4.72 million [2.99-6.70] deaths and 148 million [98.6-202] DALYs), and short gestation for birthweight (1.43 million [1.36-1.51] deaths and 139 million [131-147] DALYs). In total, risk-attributable DALYs declined by 4.9% (3.3-6.5) between 2007 and 2017. In the absence of demographic changes (ie, population growth and ageing), changes in risk exposure and risk-deleted DALYs would have led to a 23.5% decline in DALYs during that period. Conversely, in the absence of changes in risk exposure and risk-deleted DALYs, demographic changes would have led to an 18.6% increase in DALYs during that period. The ratios of observed risk exposure levels to exposure levels expected based on SDI (O/E ratios) increased globally for unsafe drinking water and household air pollution between 1990 and 2017. This result suggests that development is occurring more rapidly than are changes in the underlying risk structure in a population. Conversely, nearly universal declines in O/E ratios for smoking and alcohol use indicate that, for a given SDI, exposure to these risks is declining. In 2017, the leading Level 4 risk factor for age-standardised DALY rates was high SBP in four super-regions: central Europe, eastern Europe, and central Asia; north Africa and Middle East; south Asia; and southeast Asia, east Asia, and Oceania. The leading risk factor in the high-income super-region was smoking, in Latin America and Caribbean was high BMI, and in sub-Saharan Africa was unsafe sex. O/E ratios for unsafe sex in sub-Saharan Africa were notably high, and those for alcohol use in north Africa and the Middle East were notably low.
Interpretation: By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning
Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences
The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported
by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on
18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based
researchers who signed it in the short time span from 20 September to 6 October 2016
Efficacy of Wolbachia-mediated sterility to suppress dengue: a synthetic control study
In a study conducted in Singapore, a country prone to dengue outbreaks due to
its climate and urban population, researchers examined the effectiveness of
releasing male Aedes aegypti mosquitoes infected with Wolbachia (wAlbB strain)
to reduce dengue transmission. These infected males, when mating with wild-type
females, produced non-viable eggs, leading to vector suppression. Extensive
field trials involving over 600,000 residents in four townships were conducted
from 2018 to 2022. The results showed a 57% decline in total dengue incidence
and a 64% decline in clustered dengue incidence. This approach offers promise
for large-scale dengue control in regions facing rising dengue cases, providing
a critical solution in combating the disease
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