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JWST MIRI/MRS in-flight absolute flux calibration and tailored fringe correction for unresolved sources
No full textContext. The Medium Resolution Spectrometer (MRS) is one of the four observing modes of JWST/MIRI. Using JWST in-flight data of unresolved (point) sources, we can derive the MRS absolute spectral response function (ASRF) starting from raw data. Spectral fringing, caused by coherent reflections inside the detector arrays, plays a critical role in the derivation and interpretation of the MRS ASRF. The fringe corrections implemented in the current pipeline are not optimal for non-extended sources, and a high density of molecular features particularly inhibits an accurate correction.
Aims. In this paper, we present an alternative way to calibrate the MIRI/MRS data. Firstly, we derive a fringe correction that accounts for the dependence of the fringe properties on the MIRI/MRS pupil illumination and detector pixel sampling of the point spread function. Secondly, we derive the MRS ASRF using an absolute flux calibrator observed across the full 5–28 µm wavelength range of the MRS. Thirdly, we apply the new ASRF to the spectrum of a G dwarf and compare it with the output of the JWST/MIRI default data reduction pipeline. Finally, we examine the impact of the different fringe corrections on the detectability of molecular features in the G dwarf and K giant.
Methods. The absolute flux calibrator HD 163466 (A-star) was used to derive tailored point source fringe flats at each of the default dither locations of the MRS. The fringe-corrected point source integrated spectrum of HD 163466 was used to derive the MRS ASRF using a theoretical model for the stellar continuum. A cross-correlation was run to quantify the uncertainty on the detection of CO, SiO, and OH in the K giant and CO in the G dwarf for different fringe corrections.
Results. The point-source-tailored fringe correction and ASRF are found to perform at the same level as the current corrections, beating down the fringe contrast to the sub-percent level in the G dwarf in the longer wavelengths, whilst mitigating the alteration of real molecular features. The same tailored solutions can be applied to other MRS unresolved targets. Target acquisition is required to ensure the pointing is accurate enough to apply this method. A pointing repeatability issue in the MRS limits the effectiveness of the tailored fringe flats is at short wavelengths. Finally, resulting spectra require no scaling to make the sub-bands match, and a dichroic spectral leak at 12.2 µm is removed
Atmospheric oxidation of new “green” solvents – Part 2: methyl pivalate and pinacolone
No full textLab-based experimental and computational methods were used to study the atmospheric degradation
of two promising “green” solvents: pinacolone, (CH3)3CC(O)CH3, and methyl pivalate, (CH3)3CC(O)OCH3.
Pulsed laser photolysis coupled to pulsed laser-induced fluorescence was used to determine absolute rate coefficients (in 10−12 cm3 molec.−1
s
−1
) of k1(297 K) = (1.2 ± 0.2) for OH + (CH3)3CC(O)CH3 (Reaction R1) and
k2(297 K) = (1.3 ± 0.2) for OH + (CH3)3CC(O)OCH3 (Reaction R2), in good agreement with one previous experimental study. Rate coefficients for both reactions were found to increase at elevated temperature, with k1(T )
adequately described by k1(297–485 K) = 2.1 × 10−12 exp(−200/T ) cm3 molec.−1
s
−1
. k2(T ) exhibited more
complex behaviour, with a local minimum at around 300 K. In the course of this work, k3(295–450 K) was obtained for the well-characterised reaction OH + C2H5OH (ethanol; Reaction R3), in satisfactory agreement with
the evaluated literature.
UV–Vis spectroscopy experiments and computational calculations were used to explore cross-sections for
(CH3)3CC(O)CH3 photolysis (Reaction R4), while (CH3)3CC(O)OCH3 showed no sign of absorption over the
wavelengths of interest. Absorption cross-sections for (CH3)3CC(O)CH3, σ4(λ), in the actinic region were larger,
and the maximum was red-shifted compared to estimates (methyl ethyl ketone (MEK) values) used in current
state-of-science models. As a consequence, we note that photolysis (Reaction R4) is likely the dominant pathway
for removal of (CH3)3CC(O)CH3 from the troposphere. Nonetheless, large uncertainties remain as quantum
yields ϕ4(λ) remain unmeasured. Lifetime estimates based upon Reactions (R1) and (R4) span the range 2–9 d
and are consequently associated with a poorly constrained estimated photochemical ozone creation potential
(POCPE). In accord with previous studies, (CH3)3CC(O)OCH3 did not absorb in the actinic
The Roles of Poverty and Inequality as Factors in the Impact of Climate Change
No full textAs economies continue to grow in the face of global climate change, international
policy is focusing on the combined pursuit of social and environmental development, or
‘sustainable development goals.’ Whilst such goals are often framed from the perspective
of high-income countries, low-income countries struggle to balance their carbonintensive
growth strategies with poverty alleviation, and carbon emission reduction.
Combined with the prospect of economic growth driving income inequality higher, the
potential for a vicious cycle to emerge in low-income countries in particular is
considerable. Whilst the negative association between economic growth and poverty is
well established, the effectiveness of growth-based programmes as a poverty reduction
strategy in the context of climate change and inequality is less certain. I explore the
prospects of balancing these development goals and their consequences using an
international dataset, and generalized method of moments estimators. I find that although
economic development reduces poverty, carbon emissions (from carbon-intensive
growth) coupled with inequality, exacerbates poverty. Secondly, I find that in terms of
poverty reduction, poor countries are negatively impacted by both carbon emissions and
income inequality, while rich countries are primarily impacted by income inequality.
Lastly, my analysis reveals that the impact of emissions on poverty is more pronounced
at higher poverty bands, particularly among individuals teetering on the edge of poverty.
This could be attributed to the heightened vulnerability of their assets to climate changeinduced
risks. Conversely, those at the bottom end of the poverty spectrum may have no
assets that could be affected by climate stressors. These findings suggest that international
policies aimed at achieving globally equitable emissions reduction should take into
account the potential for disproportionate negative impacts on the impoverished
population within a country
Pesticide use, arthropod fauna and fruit damage in apple orchards in a Nordic climate
No full textBACKGROUND: Integrated pest management (IPM) has a long history in fruit production and has become even more important
with the implementation of the EU directive 2009/128/EC making IPM mandatory. In this study, we surveyed 30 apple orchards
in Norway for 3 years (2016–2018) monitoring pest- and beneficial arthropods as well as evaluating fruit damage. We obtained
growers’ diaries of pest management and used these data to study positive and negative correlations of pesticides with the different arthropod groups and damage due to pests.
RESULTS: IPM level had no significant effects on damage of harvested apples by arthropod pests. Furthermore, damage by
arthropods was mainly caused by lepidopteran larvae, tortricids being especially important. The number of insecticide applications varied between 0 and 3 per year (mean 0.8), while acaricide applications varied between 0 and 1 per year (mean 0.06).
Applications were often based on forecasts of important pest species such as the apple fruit moth (Argyresthia conjugella).
Narrow-spectrum insecticides were commonly used against aphids and lepidopteran larvae, although broad-spectrum neonicotinoid (thiacloprid) insecticides were also applied. Anthocorid bugs and phytoseiid mites were the most abundant natural
enemies in the studied orchards. However, we found large differences in abundance of various “beneficials” (e.g., lacewings,
anthocorids, parasitic wasps) between eastern and western Norway. A low level of IPM negatively affected the abundance of spiders.
CONCLUSION: Lepidoptera was found to be the most important pest group in apple orchards. Insecticide use was overall low,
but number of spray applications and use of broad-spectrum insecticides varied between growers and regions. IPM level did
not predict the level of fruit damage by insects nor the abundance of important pests or most beneficial groups in an apple orchard
Optimal age-specific vaccination control for COVID-19: An Irish case study
No full textThe outbreak of a novel coronavirus causing severe acute respiratory syndrome in December 2019 has escalated into a worldwide pandemic. In this work, we propose a compartmental model to describe the dynamics of transmission of infection and use it to obtain the optimal vaccination control. The model accounts for the various stages of the vaccination, and the optimisation is focused on minimising the infections to protect the population and relieve the healthcare system. As a case study, we selected the Republic of Ireland. We use data provided by Ireland’s COVID-19 Data-Hub and simulate the evolution of the pandemic with and without the vaccination in place for two different scenarios, one representative of a national lockdown situation and the other indicating looser restrictions in place. One of the main findings of our work is that the optimal approach would involve a vaccination programme where the older population is vaccinated in larger numbers earlier while simultaneously part of the younger population also gets vaccinated to lower the risk of transmission between groups. We compare our simulated results with those of the vaccination policy taken by the Irish government to explore the advantages of our optimisation method. Our comparison suggests that a similar reduction in cases may have been possible even with a reduced set of vaccinations available for use
False Start? An Analysis of NFL Penalties With and Without Crowds
No full textThe lack of crowds at sports fixtures as a result of COVID-19 restrictions has
allowed researchers a unique opportunity to examine the widely accepted convention of home advantage. This work takes a slightly different approach, by examining
within game outcomes. Specifically using play-by-play data from the NFL, this paper
asks whether the lack of crowds aided a Quarterback’s ability to manipulate opposition defenses. Results suggest this was the case, though effects are not uniform by
home and away team
An improved linear time-varying reactive hydrodynamic control for a grid-connected wave energy conversion system
No full textGenerally, a grid-connected wave energy conversion system consists of various standard stages, such as wave absorption, power take-off, and power conditioning. Each stage has a specific control objective, which may not align with the control objectives of other stages, affecting overall wave-to-grid economic performance. This study assesses a controlled grid-connected wave energy conversion system with an improved reactive hydrodynamic WEC controller, i.e. LiTe-Con+. In particular, the LiTe-Con+ adapts its constraint handling mechanism in a time-varying manner, providing improved power absorption and use of the dynamic range. Lyapunov-based nonlinear controllers are also designed for the power converters in the powertrain. The proposed system is then simulated in the MATLAB/SIMULINK environment in order to demonstrate the effectiveness of the proposed control scheme. The results show the superior performance of LiTe-Con+ compared to LiTe-Con and passive damping controllers
Adaptive P300-Based Brain-Computer Interface for Attention Training: Protocol for a Randomized Controlled Trial
No full textBackground: The number of people with cognitive deficits and diseases, such as stroke, dementia, or attention-deficit/hyperactivity disorder, is rising due to an aging, or in the case of attention-deficit/hyperactivity disorder, a growing population. Neurofeedback training using brain-computer interfaces is emerging as a means of easy-to-use and noninvasive cognitive training and rehabilitation. A novel application of neurofeedback training using a P300-based brain-computer interface has previously shown potential to improve attention in healthy adults. Objective: This study aims to accelerate attention training using iterative learning control to optimize the task difficulty in an adaptive P300 speller task. Furthermore, we hope to replicate the results of a previous study using a P300 speller for attention training, as a benchmark comparison. In addition, the effectiveness of personalizing the task difficulty during training will be compared to a nonpersonalized task difficulty adaptation. Methods: In this single-blind, parallel, 3-arm randomized controlled trial, 45 healthy adults will be recruited and randomly assigned to the experimental group or 1 of 2 control groups. This study involves a single training session, where participants receive neurofeedback training through a P300 speller task. During this training, the task's difficulty is progressively increased, which makes it more difficult for the participants to maintain their performance. This encourages the participants to improve their focus. Task difficulty is either adapted based on the participants' performance (in the experimental group and control group 1) or chosen randomly (in control group 2). Changes in brain patterns before and after training will be analyzed to study the effectiveness of the different approaches. Participants will complete a random dot motion task before and after the training so that any transfer effects of the training to other cognitive tasks can be evaluated. Questionnaires will be used to estimate the participants' fatigue and compare the perceived workload of the training between groups. Results: This study has been approved by the Maynooth University Ethics Committee (BSRESC-2022-2474456) and is registered on ClinicalTrials.gov (NCT05576649). Participant recruitment and data collection began in October 2022, and we expect to publish the results in 2023. Conclusions: This study aims to accelerate attention training using iterative learning control in an adaptive P300 speller task, making it a more attractive training option for individuals with cognitive deficits due to its ease of use and speed. The successful replication of the results from the previous study, which used a P300 speller for attention training, would provide further evidence to support the effectiveness of this training tool. Trial registration: ClinicalTrials.gov NCT05576649; https://clinicaltrials.gov/ct2/show/NCT05576649. International registered report identifier (irrid): DERR1-10.2196/46135
Can Views and Contact with Nature at Home Help Combat Anxiety and Depression during the Pandemic? Results of the GreenCOVID study
No full textBackground: The COVID-19 pandemic and the lockdown measures have had important consequences on the mental health of the population, although little is known
about the role played by nature and its benefits.
Objectives: The present study aims to evaluate the risk of anxiety and depression
during the first wave of the COVID-19 pandemic in Spain and to identify the factors
most strongly associated with anxiety and depression, including sociodemographic,
household characteristics, and access to or contact with natural environment.
Methods: GreenCOVID is an online cross-sectional study promoted by the Health &
Territory Research (HTR) of the University of Seville in Spain, Maynooth University in
Ireland, and the University of Winchester in the United Kingdom. This study includes
only data from Spain which were collected between April 8, 2020 and April 27, 2020.
Binary logistic regression was conducted to identify the factors associated with anxiety
and depression through the HADS scale.
Results: Of the total of 2,464 adults who participated in GreenCOVID Spain, mean
age was 38.1 years, 72.6% were female, 58.1% were at risk of anxiety, and 32.3% of
depression. In the multivariable logistic regression, the factors associated with risk of
anxiety were female: gender, being a student and problems at home. Regarding the risk
of depression, the factors most associated were being a student, female gender, problems at home, worse evaluation of views from home and less help from outside views
to cope with lockdown.
Conclusions: Our findings show that during COVID-19 pandemic, in addition to
sociodemographic factors female gender and being a student, problems at home, lack
of natural elements in the home, and worse appreciation of views from home were
associated with mental health problems. Thus, housing conditions and access to the
natural environment were important for mental health during COVID-19 lockdown
Psychological consequences of war in Ukraine: assessing changes in mental health among Ukrainian parents
No full textRussia's ongoing war on Ukraine has profoundly changed the lives of millions of people (United Nations, 2023), and the mental health community has warned of potential long-term negative mental health consequences (Morganstein, Bromet, & Shigemura, Reference Morganstein, Bromet and Shigemura2022). The adverse mental health effects of war are well-established (Jain et al., Reference Jain, Prasad, Czárth, Chodnekar, Mohan, Savchenko, Panag and Reinis2022), and there is evidence that Russia's 2014 invasion of the south and east of Ukraine (Shevlin et al., Reference Shevlin, Hyland, Vallières, Bisson, Makhashvili, Javakhishvili and Roberts2018) and the full-scale invasion in 2022 (Karatzias et al., Reference Karatzias, Shevlin, Ben-Ezra, McElroy, Redican, Vang and Hyland2023) has led to serious psychological harm among the population. In this study, we report on changes in anxiety, depression, loneliness, and hazardous drinking following the 24 February 2022 invasion, and the correlates of changes in these mental health problems