52 research outputs found
Nonlinear and delayed impacts of climate on dengue risk in Barbados: A modelling study
Background: Over the last 5 years (2013–2017), the Caribbean region has faced an unprecedented crisis of co-occurring epidemics of febrile illness due to arboviruses transmitted by the Aedes sp. mosquito (dengue, chikungunya, and Zika). Since 2013, the Caribbean island of Barbados has experienced 3 dengue outbreaks, 1 chikungunya outbreak, and 1 Zika fever outbreak. Prior studies have demonstrated that climate variability influences arbovirus transmission and vector population dynamics in the region, indicating the potential to develop public health interventions using climate information. The aim of this study is to quantify the nonlinear and delayed effects of climate indicators, such as drought and extreme rainfall, on dengue risk in Barbados from 1999 to 2016. Methods and findings: Distributed lag nonlinear models (DLNMs) coupled with a hierarchal mixed-model framework were used to understand the exposure–lag–response association between dengue relative risk and key climate indicators, including the standardised precipitation index (SPI) and minimum temperature (Tmin). The model parameters were estimated in a Bayesian framework to produce probabilistic predictions of exceeding an island-specific outbreak threshold. The ability of the model to successfully detect outbreaks was assessed and compared to a baseline model, representative of standard dengue surveillance practice. Drought conditions were found to positively influence dengue relative risk at long lead times of up to 5 months, while excess rainfall increased the risk at shorter lead times between 1 and 2 months. The SPI averaged over a 6-month period (SPI-6), designed to monitor drought and extreme rainfall, better explained variations in dengue risk than monthly precipitation data measured in millimetres. Tmin was found to be a better predictor than mean and maximum temperature. Furthermore, including bidimensional exposure–lag–response functions of these indicators—rather than linear effects for individual lags—more appropriately described the climate–disease associations than traditional modelling approaches. In prediction mode, the model was successfully able to distinguish outbreaks from nonoutbreaks for most years, with an overall proportion of correct predictions (hits and correct rejections) of 86% (81%:91%) compared with 64% (58%:71%) for the baseline model. The ability of the model to predict dengue outbreaks in recent years was complicated by the lack of data on the emergence of new arboviruses, including chikungunya and Zika. Conclusion: We present a modelling approach to infer the risk of dengue outbreaks given the cumulative effect of climate variations in the months leading up to an outbreak. By combining the dengue prediction model with climate indicators, which are routinely monitored and forecasted by the Regional Climate Centre (RCC) at the Caribbean Institute for Meteorology and Hydrology (CIMH), probabilistic dengue outlooks could be included in the Caribbean Health-Climatic Bulletin, issued on a quarterly basis to provide climate-smart decision-making guidance for Caribbean health practitioners. This flexible modelling approach could be extended to model the risk of dengue and other arboviruses in the Caribbean region
Salve Regina University Act on Climate: Strategic Plan for the University to Reach State Carbon Neutrality Goals
In order to become more sustainable and meet the mandate set by the 2021 Rhode Island Act on Climate law (RI General Law §42-6.2), Salve Regina University must work to reach net-zero greenhouse gas emissions by the year 2050. Action to meet these standards begins now and must be continually built upon to ensure that Salve Regina University, as leader in Rhode Island, is always working for a more sustainable future. Throughout the Spring 2022 semester, students of the BIO-140: Humans and Their Environment course instructed by Dr. Jameson Chace have researched ways in which Salve Regina can begin on the path to zero greenhouse gas emissions today. By focusing on change in the areas of energy, transportation, food, financial investments, and sequestration, Salve Regina can reduce the greenhouse gas emissions of today for a more sustainable tomorrow. Recommendations are broken into three time periods. Action for today to achieve by 2030 include improving energy efficiency, installing the first electric vehicle (EV) parking/charging stations, increasing carbon sequestration, reducing beef in the campus diet, and assessing the carbon impact of university financial holdings. Actions to be initiated soon and to be achieved by 2040 include shifting away from natural gas heating when system renewals take place, increasing EV parking to meet rising demand, during turnover replace current university vehicles with electric or hybrid, continuing with sequestration efforts on campus, begin phasing out high carbon diet items, and by 2040 the university investment portfolio should be carbon neutral. If carbon neutrality can be reached by 2050 the most challenging aspects of campus life that need to change will require planning now and thoughtful implementation. The class in 2022 envisions a campus in 2050 where solar lights illuminate campus and buildings through the night, all university vehicles and most faculty and staff vehicles are electric and are found charging during the day at solar powered charging stations, dining services in Miley supports community agriculture and includes incentives for meatless and low carbon meal plans, the university has become a leader in low carbon/green market investing demonstrating how careful planning can reap high returns, and carbon sequestration on campus grounds has maximized such that off campus carbon offsets are established with local land trusts to complete the carbon neutrality goals. In doing so no only will the university be recognized as a state-wide leader in climate action, but will also be a global leader in working towards a world that is more harmonious, just, and merciful.https://digitalcommons.salve.edu/bio140_arboretum/1033/thumbnail.jp
SN 2022joj: A Peculiar Type Ia Supernova Possibly Driven by an Asymmetric Helium-shell Double Detonation
We present observations of SN 2022joj, a peculiar Type Ia supernova (SN Ia)
discovered by the Zwicky Transient Facility (ZTF). SN 2022joj exhibits an
unusually red color at early times and a rapid
blueward evolution afterwards. Around maximum brightness, SN 2022joj shows a
high luminosity ( mag), a blue
broadband color ( mag), and shallow Si
II absorption lines, consistent with those of overluminous, SN 1991T-like
events. The maximum-light spectrum also shows prominent absorption around 4200
\r{A}, which resembles the Ti II features in subluminous, SN 1991bg-like
events. Despite the blue optical-band colors, SN 2022joj exhibits extremely red
ultraviolet optical colors at maximum luminosity ( mag and
mag), suggesting a suppression of flux between
2500--4000 \r{A}. Strong C II lines are also detected at peak. We show
that these unusual spectroscopic properties are broadly consistent with the
helium-shell double detonation of a sub-Chandrasekhar mass
() carbon/oxygen (C/O) white dwarf (WD) from a
relatively massive helium shell (--), if
observed along a line of sight roughly opposite to where the shell initially
detonates. None of the existing models could quantitatively explain all the
peculiarities observed in SN 2022joj. The low flux ratio of [Ni II]
7378 to [Fe II] 7155 emission in the late-time nebular
spectra indicates a low yield of stable Ni isotopes, favoring a
sub-Chandrasekhar mass progenitor. The significant blueshift measured in the
[Fe II] 7155 line is also consistent with an asymmetric chemical
distribution in the ejecta, as is predicted in double-detonation models.Comment: 24 pages, 11 figures, 6 tables. Submitted to Ap
Co-developing climate services for public health: Stakeholder needs and perceptions for the prevention and control of Aedes-transmitted diseases in the Caribbean.
BACKGROUND: Small island developing states (SIDS) in the Caribbean region are challenged with managing the health outcomes of a changing climate. Health and climate sectors have partnered to co-develop climate services to improve the management of emerging arboviral diseases such as dengue fever, for example, through the development of climate-driven early warning systems. The objective of this study was to identify health and climate stakeholder perceptions and needs in the Caribbean, with respect to the development of climate services for arboviruses. METHODS: Stakeholders included public decision makers and practitioners from the climate and health sectors at the regional (Caribbean) level and from the countries of Dominica and Barbados. From April to June 2017, we conducted interviews (n = 41), surveys (n = 32), and national workshops with stakeholders. Survey responses were tabulated, and audio recordings were transcribed and analyzed using qualitative coding to identify responses by research topic, country/region, and sector. RESULTS: Health practitioners indicated that their jurisdiction is currently experiencing an increased risk of arboviral diseases associated with climate variability, and most anticipated that this risk will increase in the future. National health sectors reported financial limitations and a lack of technical expertise in geographic information systems (GIS), statistics, and modeling, which constrained their ability to implement climate services for arboviruses. National climate sectors were constrained by a lack of personnel. Stakeholders highlighted the need to strengthen partnerships with the private sector, academia, and civil society. They identified a gap in local research on climate-arbovirus linkages, which constrained the ability of the health sector to make informed decisions. Strategies to strengthen the climate-health partnership included a top-down approach by engaging senior leadership, multi-lateral collaboration agreements, national committees on climate and health, and shared spaces of dialogue. Mechanisms for mainstreaming climate services for health operations to control arboviruses included climatic-health bulletins and an online GIS platform that would allow for regional data sharing and the generation of spatiotemporal epidemic forecasts. Stakeholders identified a 3-month forecast of arboviral illness as the optimal time frame for an epidemic forecast. CONCLUSIONS: These findings support the creation of interdisciplinary and intersectoral 'communities of practice' and the co-design of climate services for the Caribbean public health sector. By fostering the effective use of climate information within health policy, research and practice, nations will have greater capacity to adapt to a changing climate
SN Zwicky: uncovering a population of gravitational lens galaxies with magnified "standard candles"
We report the discovery of a very rare phenomenon, a multiply-imaged
gravitationally lensed Type Ia supernova (SNe Ia), "SN Zwicky", a.k.a. SN
2022qmx, magnified nearly twenty-five times by a foreground galaxy. The system
was identified as intrinsically bright thanks to the "standard candle" nature
of SNe Ia. Observations with high-spatial resolution instruments resolved a
system with four nearly simultaneous images, with an Einstein radius of only
, corresponding to a lens mass of solar masses
within a physical size below kiloparsecs. A smooth lens model fails to
reproduce the image flux ratios, suggesting significant additional
magnification from compact objects. Given the small image splitting and a
relatively faint deflecting galaxy, the lensing system would not have been
found through the angular separation technique generally used in large imaging
surveys
Probing pre-supernova mass loss in double-peaked Type Ibc supernovae from the Zwicky Transient Facility
Eruptive mass loss of massive stars prior to supernova (SN) explosion is key
to understanding their evolution and end fate. An observational signature of
pre-SN mass loss is the detection of an early, short-lived peak prior to the
radioactive-powered peak in the lightcurve of the SN. This is usually
attributed to the SN shock passing through an extended envelope or
circumstellar medium (CSM). Such an early peak is common for double-peaked Type
IIb SNe with an extended Hydrogen envelope but is uncommon for normal Type Ibc
SNe with very compact progenitors. In this paper, we systematically study a
sample of 14 double-peaked Type Ibc SNe out of 475 Type Ibc SNe detected by the
Zwicky Transient Facility. The rate of these events is ~ 3-9 % of Type Ibc SNe.
A strong correlation is seen between the peak brightness of the first and the
second peak. We perform a holistic analysis of this sample's photometric and
spectroscopic properties. We find that six SNe have ejecta mass less than 1.5
Msun. Based on the nebular spectra and lightcurve properties, we estimate that
the progenitor masses for these are less than ~ 12 Msun. The rest have an
ejecta mass > 2.4 Msun and a higher progenitor mass. This sample suggests that
the SNe with low progenitor masses undergo late-time binary mass transfer.
Meanwhile, the SNe with higher progenitor masses are consistent with
wave-driven mass loss or pulsation-pair instability-driven mass loss
simulations.Comment: Submitted to ApJ. Comments are welcome. arXiv admin note: text
overlap with arXiv:2210.0572
Comparative Developmental Expression Profiling of Two C. elegans Isolates
Gene expression is known to change during development and to vary among genetically diverse strains. Previous studies of temporal patterns of gene expression during C. elegans development were incomplete, and little is known about how these patterns change as a function of genetic background. We used microarrays that comprehensively cover known and predicted worm genes to compare the landscape of genetic variation over developmental time between two isolates of C. elegans. We show that most genes vary in expression during development from egg to young adult, many genes vary in expression between the two isolates, and a subset of these genes exhibit isolate-specific changes during some developmental stages. This subset is strongly enriched for genes with roles in innate immunity. We identify several novel motifs that appear to play a role in regulating gene expression during development, and we propose functional annotations for many previously unannotated genes. These results improve our understanding of gene expression and function during worm development and lay the foundation for linkage studies of the genetic basis of developmental variation in gene expression in this important model organism
Knowledge Exchange Processes in Multicultural Teams: Linking Organizational Diversity Climates to Teams’ Effectiveness
We developed an evidence-based model illuminating team knowledge exchange processes as a key link between organizational diversity climate and the effectiveness of multicultural teams (MCTs). Our analysis is based on 143 in-depth interviews and extensive observations of team interactions that occurred in 48 teams from 11 companies. Our findings revealed that teams that oscillated between assertive and cooperative knowledge exchange processes were more effective. We also found such dual processes were more prevalent in organizations that had an engagement-focused diversity climate characterized by utilization of diversity to inform and enhance work processes based on the assumption that cultural differences give rise to different knowledge, insights, and alternative views. Based on our findings we developed specific propositions about optimizing MCT knowledge-exchange processes to guide future research and practice
Factorial structure of a scale: Strategies used by people to promote health - Chinese version
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