8,818 research outputs found
Effects of municipal smoke-free ordinances on secondhand smoke exposure in the Republic of Korea
ObjectiveTo reduce premature deaths due to secondhand smoke (SHS) exposure among non-smokers, the Republic of Korea (ROK) adopted changes to the National Health Promotion Act, which allowed local governments to enact municipal ordinances to strengthen their authority to designate smoke-free areas and levy penalty fines. In this study, we examined national trends in SHS exposure after the introduction of these municipal ordinances at the city level in 2010.MethodsWe used interrupted time series analysis to assess whether the trends of SHS exposure in the workplace and at home, and the primary cigarette smoking rate changed following the policy adjustment in the national legislation in ROK. Population-standardized data for selected variables were retrieved from a nationally representative survey dataset and used to study the policy action’s effectiveness.ResultsFollowing the change in the legislation, SHS exposure in the workplace reversed course from an increasing (18% per year) trend prior to the introduction of these smoke-free ordinances to a decreasing (−10% per year) trend after adoption and enforcement of these laws (β2 = 0.18, p-value = 0.07; β3 = −0.10, p-value = 0.02). SHS exposure at home (β2 = 0.10, p-value = 0.09; β3 = −0.03, p-value = 0.14) and the primary cigarette smoking rate (β2 = 0.03, p-value = 0.10; β3 = 0.008, p-value = 0.15) showed no significant changes in the sampled period. Although analyses stratified by sex showed that the allowance of municipal ordinances resulted in reduced SHS exposure in the workplace for both males and females, they did not affect the primary cigarette smoking rate as much, especially among females.ConclusionStrengthening the role of local governments by giving them the authority to enact and enforce penalties on SHS exposure violation helped ROK to reduce SHS exposure in the workplace. However, smoking behaviors and related activities seemed to shift to less restrictive areas such as on the streets and in apartment hallways, negating some of the effects due to these ordinances. Future studies should investigate how smoke-free policies beyond public places can further reduce the SHS exposure in ROK
A note on energy minimization in dimension 2
Proving the universal optimality of the hexagonal lattice is one of the big
open challenges of nowadays mathematics. We show that the hexagonal lattice
outperforms certain "natural" classes of periodic configurations. Also, we rule
out the option that the canonical non-lattice rival -- the honeycomb -- has
lower energy than the hexagonal lattice at any scale.Comment: 13 pages, 3 figures, 21 reference
Improving the predictive capability of the soil erosion modeling tool EROSION-3D: From observation data to validation
Ziel dieser Arbeit ist die Verbesserung der Vorhersagekraft des Bodenerosionsmodelierungs-werkzeugs EROSION-3D, welche oftmals durch die Identifizierung der werkzeugspezifischen Parameter Skinfaktor und Erosionswiderstand limitiert ist.
Als drei Betrachtungsebenen der Arbeit werden 1. Beobachtungsdaten, 2. die Fähigkeit von EROSION-3D zur Beschreibung der Beobachtungsdaten und 3. die Vorhersagekraft des Werkzeugs untersucht. Aufzeichnungen verschiedener Beregnungsversuche wurden maschinenlesbar zusammengefasst. Daran wurde EROSION-3D mit den bisher üblichen sowie Monte-Carlo Methoden kalibriert. Anhand beschreibender Daten der Beregnungsversuche wurden Vorhersagemethoden zur Schätzung der modellspezifischen Parameter entwickelt und hinsichtlich der Parameterwerte und damit modellierter Abfluss-/Abtragswerte validiert.
Die Ergebnisse zeigen, dass verbesserte Vorhersagen mit den neuen Schätzmethoden möglich sind, aber auch Möglichkeiten zur Verbesserung der Modellstruktur bestehen
Historical Burdens on Physics
When learning physics, one follows a track very similar to the historical path of the evolution of this science: one takes detours, overcomes superfluous obstacles and repeats mistakes, one learns inappropriate concepts and uses outdated methods. In the book, more than 200 articles present and analyze such obsolete concepts methods. All articles have the same structure: 1. subject, 2. deficiencies, 3. origin, 4. disposal. The articles had originally appeared as columns in various magazines. Accordingly, we had tried to write them in an easily understandable way
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Data-physics Driven Reduced Order Homogenization
A hybrid data-physics driven reduced-order homogenization (dpROH) approach aimed at improving the accuracy of the physics-based reduced order homogenization (pROH), but retain its unique characteristics, such as interpretability and extrapolation, has been developed. The salient feature of the dpROH is that the data generated by a high-fidelity model based on the direct numerical simulations with periodic boundary conditions improve markedly the accuracy of the physic-based model reduction. The dpROH consist of the offline and online stages. In the offline stage, dpROH utilized surrogate-based Bayesian Inference to extract crucial information at the representative volume element (RVE) level. With the inferred data, online predictions are performed using a data-enhanced reduced order homogenization. The proposed method combines the benefits of physics-based reduced order homogenization and data-driven surrogate modeling, striking a balance between accuracy, computational efficiency, and physical interpretability.
The dpROH method, as suggested, has the versatility to be utilized across different RVE geometries (including fibrous and woven structures) and various constitutive models, including elasto-plasticity and continuum damage models. Through numerical examples that involve comparisons between different variants of dpROH, pROH, and the reference solution, the method showcases enhanced accuracy and efficiency, validating its effectiveness for a wide range of applications. A novel pseudo-nonlocal eight-node fully integrated linear hexahedral element, PN3D8, has been developed to accelerate the computational efficiency of multiscale modeling for complex material systems.
This element is specifically designed to facilitate finite element analysis of computationally demanding material models, enabling faster and more efficient simulations within the scope of multiscale modeling. The salient feature of the PN3D8 is that it employs reduced integration for stress updates but full integration for element matrices (residual and its consistent tangent stiffness). This is accomplished by defining pseudo-nonlocal and local stress measures. Only the pseudo-nonlocal stress is updated for a given value of mean strain or mean deformation measure for large deformation problems. The local stress is then post-processed at full integration points for evaluation of the internal force and consistent tangent stiffness matrices. The resulting tangent stiffness matrix has a symmetric canonical structure with an identical instantaneous constitutive matrix at all quadrature points of an element. For linear elasticity problems, the formulation of the PN3D8 finite element coincides with the classical eight-node fully integrated linear hexahedral element. The procedure is illustrated for small and large deformation two-scale quasistatic problems
Ovarian hormones shape brain structure, function, and chemistry: A neuropsychiatric framework for female brain health
There are robust sex differences in brain anatomy, function, as well as neuropsychiatric and neurodegenerative disease risk (1-6), with women approximately twice as likely to suffer from a depressive illness as well as Alzheimer’s Disease. Disruptions in ovarian hormones likely play a role in such disproportionate disease prevalence, given that ovarian hormones serve as key regulators of brain functional and structural plasticity and undergo major fluctuations across the female lifespan (7-9). From a clinical perspective, there is a wellreported increase in depression susceptibility and initial evidence for cognitive impairment or decline during hormonal transition states, such as the postpartum period and perimenopause (9-14). What remains unknown, however, is the underlying mechanism of how fluctuations in ovarian hormones interact with other biological factors to influence brain structure, function, and chemistry. While this line of research has translational relevance for over half the population, neuroscience is notably guilty of female participant exclusion in research studies, with the male brain implicitly treated as the default model and only a minority of basic and clinical neuroscience studies including a female sample (15-18). Female underrepresentation in neuroscience directly limits opportunities for basic scientific discovery; and without basic knowledge of the biological underpinnings of sex differences, we cannot address critical sexdriven differences in pathology. Thus, my doctoral thesis aims to deliberately investigate the influence of sex and ovarian hormones on brain states in health as well as in vulnerability to depression and cognitive impairment:Table of Contents
List of Abbreviations ..................................................................................................................... i
List of Figures .............................................................................................................................. ii
Acknowledgements .....................................................................................................................iii
1 INTRODUCTION .....................................................................................................................1
1.1 Lifespan approach: Sex, hormones, and metabolic risk factors for cognitive health .......3
1.2 Reproductive years: Healthy models of ovarian hormones, serotonin, and the brain ......4
1.2.1 Ovarian hormones and brain structure across the menstrual cycle ........................4
1.2.2 Serotonergic modulation and brain function in oral contraceptive users .................6
1.3 Neuropsychiatric risk models: Reproductive subtypes of depression ...............................8
1.3.1 Hormonal transition states and brain chemistry measured by PET imaging ...........8
1.3.2 Serotonin transporter binding across the menstrual cycle in PMDD patients .......10
2 PUBLICATIONS ....................................................................................................................12
2.1 Publication 1: Association of estradiol and visceral fat with structural brain networks
and memory performance in adults .................................................................................13
2.2 Publication 2: Longitudinal 7T MRI reveals volumetric changes in subregions of
human medial temporal lobe to sex hormone fluctuations ..............................................28
2.3 Publication 3: One-week escitalopram intake alters the excitation-inhibition balance
in the healthy female brain ...............................................................................................51
2.4 Publication 4: Using positron emission tomography to investigate hormone-mediated
neurochemical changes across the female lifespan: implications for depression ..........65
2.5 Publication 5: Increase in serotonin transporter binding across the menstrual cycle in
patients with premenstrual dysphoric disorder: a case-control longitudinal neuro-
receptor ligand PET imaging study ..................................................................................82
3 SUMMARY ...........................................................................................................................100
References ..............................................................................................................................107
Supplementary Publications ...................................................................................................114
Author Contributions to Publication 1 .....................................................................................184
Author Contributions to Publication 2 .....................................................................................186
Author Contributions to Publication 3 .....................................................................................188
Author Contributions to Publication 4 .....................................................................................190
Author Contributions to Publication 5 .....................................................................................191
Declaration of Authenticity ......................................................................................................193
Curriculum Vitae ......................................................................................................................194
List of Publications ................................................................................................................195
List of Talks and Posters ......................................................................................................19
Numerical modeling for groundwater protection in the Venetian plain between the Brenta and Piave Rivers
The Ph.D. project tackled the scientific challenges that a water utility company in the northeast of Italy, Alto Trevigiano Servizi, must face in the elaboration of the Water Safety Plan (WSP), which is the most effective preventive tool to ensure good quality water and consumers health protection. The WSPs guidelines were defined by the World Health Organization and were subsequently implemented in a European Directive and Italian law.
The thesis, after an introduction on the scientifical issues, started with the description of the work done to reproduce in CATHY the model that the PhD student Tommaso Trentin built using the software FeFlow.
The study area has an extension of around 900 km2 and is delimited to the north-east by the Piave river, to the west side by a flow line parallel to the Brenta river, while the southern boundary is closed by the Risorgive area, and the North boundary by the Montello and colli Asolani.
The north part is characterized by an undifferentiated aquifer, while the southern part hosts a multilayer system with 8 confined aquifers.
Some modifications, e.g., the mesh refining, the sensitivity analysis, were implemented in the model to try to improve its performance. Also, the soil conductivity of the shallowest soil layer (1 m) was changed following the indications of Carta della permeabilità dei suoli from ARPAV site and the boundary conditions of the norther part of the domain were better defined.
Before the calibration step, the initial mesh that hosts the multilayers systems of 8 aquitards and 8 aquifers was cut at the bottom of the first unconfined aquifer. This allowed to speed up the calibration and focus on the aquifer directly influenced by the atmospheric boundary conditions and subject to recharge variability. The calibration was performed alternating FePESt and CATHY. FePEST, having already implemented the PEST algorithm, allowed to easily implement the pilot points method that in CATHY would have require too much time. Both the bottom of the unconfined aquifer and the hydraulic conductivity field were calibrated. The improvement in terms of RMSE was relevant, the errors being reduced to 1/3. Once the calibrated model was obtained, also a validation step was performed. The resulting model allowed us to investigate an irrigation variation scenario, planned in compliance with the European directive indication, to save water: currently a large area of the domain is interested by flood irrigation considered no more sustainable, since it requires a large amount of water. The scenario considered a switch to sprinkler irrigation only. The results show a slight groundwater head decrease in the wells located in the area affected by the irrigation technique conversion. This result was confirmed by the difference of the total cumulative recharge over the domain in case of sprinkler and flood irrigation and sprinkler irrigation only. The model seems to be not particularly affected by the irrigation modification but more sensitive to the hydraulic conductivity values: a map of the mean distribution of the recharge shows that the larger fraction of the recharge occurs where hydraulic conductivity is larger.
Parallelly to the continuation of this project, also a study on the analysis of numerical dispersion affecting CATHY model was carry out. This study will be useful for future simulations on vulnerability to contaminations that require an accurate solute transport modeling.
Due to lack of time it was not possible to investigate the contaminants transport phenomenon in the area of study to accurately define the wells’ head protection areas, important part of the WSPs, but the preliminary results obtained from the model we built can be considered a good starting point for future transport studies.The Ph.D. project tackled the scientific challenges that a water utility company in the northeast of Italy, Alto Trevigiano Servizi, must face in the elaboration of the Water Safety Plan (WSP), which is the most effective preventive tool to ensure good quality water and consumers health protection. The WSPs guidelines were defined by the World Health Organization and were subsequently implemented in a European Directive and Italian law.
The thesis, after an introduction on the scientifical issues, started with the description of the work done to reproduce in CATHY the model that the PhD student Tommaso Trentin built using the software FeFlow.
The study area has an extension of around 900 km2 and is delimited to the north-east by the Piave river, to the west side by a flow line parallel to the Brenta river, while the southern boundary is closed by the Risorgive area, and the North boundary by the Montello and colli Asolani.
The north part is characterized by an undifferentiated aquifer, while the southern part hosts a multilayer system with 8 confined aquifers.
Some modifications, e.g., the mesh refining, the sensitivity analysis, were implemented in the model to try to improve its performance. Also, the soil conductivity of the shallowest soil layer (1 m) was changed following the indications of Carta della permeabilità dei suoli from ARPAV site and the boundary conditions of the norther part of the domain were better defined.
Before the calibration step, the initial mesh that hosts the multilayers systems of 8 aquitards and 8 aquifers was cut at the bottom of the first unconfined aquifer. This allowed to speed up the calibration and focus on the aquifer directly influenced by the atmospheric boundary conditions and subject to recharge variability. The calibration was performed alternating FePESt and CATHY. FePEST, having already implemented the PEST algorithm, allowed to easily implement the pilot points method that in CATHY would have require too much time. Both the bottom of the unconfined aquifer and the hydraulic conductivity field were calibrated. The improvement in terms of RMSE was relevant, the errors being reduced to 1/3. Once the calibrated model was obtained, also a validation step was performed. The resulting model allowed us to investigate an irrigation variation scenario, planned in compliance with the European directive indication, to save water: currently a large area of the domain is interested by flood irrigation considered no more sustainable, since it requires a large amount of water. The scenario considered a switch to sprinkler irrigation only. The results show a slight groundwater head decrease in the wells located in the area affected by the irrigation technique conversion. This result was confirmed by the difference of the total cumulative recharge over the domain in case of sprinkler and flood irrigation and sprinkler irrigation only. The model seems to be not particularly affected by the irrigation modification but more sensitive to the hydraulic conductivity values: a map of the mean distribution of the recharge shows that the larger fraction of the recharge occurs where hydraulic conductivity is larger.
Parallelly to the continuation of this project, also a study on the analysis of numerical dispersion affecting CATHY model was carry out. This study will be useful for future simulations on vulnerability to contaminations that require an accurate solute transport modeling.
Due to lack of time it was not possible to investigate the contaminants transport phenomenon in the area of study to accurately define the wells’ head protection areas, important part of the WSPs, but the preliminary results obtained from the model we built can be considered a good starting point for future transport studies
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Incorporating Biodiversity-Ecosystem Function Relationships into Models and Conservation Planning
Unsustainable use of nature and climate change are leading to unprecedented biodiversity declines. These declines have cascading impacts on ecosystem function and ecosystem services, and ultimately on human well-being. International agreements have been adopted that aim to address both crises. The Paris Agreement, adopted in 2015, set global emission reductions targets. In 2022, most countries agreed to the Kunming-Montreal Global Biodiversity Framework (GBF). The GBF sets 23 ambitious targets for 2030 ranging from reducing threats to biodiversity, meeting people’s needs through sustainable use and benefit sharing, and solutions for implementation.
Although adopting global goals and targets is an important first step, additional work is required for on-the-ground implementation. Important knowledge gaps include understanding how biodiversity, ecosystem functions, and ecosystem services are linked, modeling how policy scenarios could lead to different outcomes for biodiversity and ecosystem services, and guidance for where and how to prioritize conservation actions. This dissertation aims to fill some of these gaps. Chapters 1 and 2 explore how biodiversity conservation can affect important ecosystem functions and services. Chapter 3 moves from improving our baseline knowledge to thinking about how we can achieve our conservation goals through prioritizing restoration actions.
In chapter 1, I focus on the importance of biodiversity-ecosystem function relationships for urban systems. The proportion of people living in urban areas is growing globally. Thus, understanding how to manage urban biodiversity, ecosystem functions, and ecosystem services is important. Biodiversity can increase ecosystem functioning in natural systems. However, few studies have assessed the relationship between biodiversity and ecosystem functioning in urban areas, which differ in abiotic factors, species compositions, food webs, and turnover rates. I systematically reviewed documented evidence of biodiversity-ecosystem function relationships in urban environments and assessed factors that influenced the direction of the relationships.
I show that increasing biodiversity, even in small areas, can increase local ecosystem functioning in urban areas. Therefore, local management that increases biodiversity can have positive benefits for ecosystems and people. I also identify research gaps and opportunities to improve biodiversity-ecosystem function research in the urban realm moving forward and discuss how to improve urban green space management.
In chapter 2, I explored how biodiversity-ecosystem functioning relationships can be incorporated into modeling. Models of how changes in drivers, including land use change and climate change, lead to changes in biodiversity and ecosystem services are useful tools for policymakers as they consider how to sustainably manage natural resources. Despite known interactions between biodiversity, ecosystem functioning, and ecosystem services, models projecting changes in these domains typically operate independently and do not account for interactions or feedbacks, which may lead to inaccurate estimates in ecosystem functioning and ecosystem service projections. In this chapter, I focused on how plant species diversity affects biomass production and carbon storage. I used the Biogeographic Infrastructure for Large‐scaled Biodiversity Indicators (BILBI) model, a macroecological community-level model, to estimate plant species persistence under different climate and land use change scenarios in 2050. I linked this with empirical data on biodiversity-biomass production relationships to assess how biodiversity loss will affect carbon storage globally.
I found that biodiversity has the potential to cause as much carbon loss as emissions from other sources (i.e., they are within the range of uncertainty from biodiversity-mediated carbon loss), so achieving Sustainable Development Goal 15 (Life on Land) is essential to achieving Goal 13 (Climate Action). Because the Paris Agreement does not account for emissions from biodiversity loss, science on its carbon impacts, and action as a result, could be underestimated. This analysis points to the important role that maintaining and/or enhancing the diversity of plant species within areas of natural vegetation, rather than simply maximizing the extent of these areas, can play in addressing the climate change crisis. Alongside increasing the global extent of protected areas to prevent rapid carbon loss from ecosystem degradation, increasing plant species diversity in degraded ecosystems can increase carbon storage potential. However, existing international initiatives like the Bonn Challenge and the Paris Agreement focus on forest extent rather than forest quality for protection, afforestation, and reforestation, and thus are missing a key opportunity for action.
In chapter 3, I looked at how we can achieve proposed biodiversity conservation goals. Reversing trends in biodiversity loss and achieving the Convention on Biological Diversity (CBD) 2050 vision of “Living in harmony with nature” will require not only conserving remaining biodiversity, but also restoring degraded areas. Recent legislative and executive actions in the U.S. have recognized the importance of restoration. Given limited budgets, deciding where to restore habitat will be an important need in the coming decade. In this chapter, I developed a modeling approach to maximize conservation benefit/restoration cost ratios that can be used to map restoration priorities. I illustrated this approach using a case study for highly threatened grassland ecosystems in the Great Plains region of Kansas.
I found that for the indicator species that we chose, shortgrass and mixed-grass prairies had the highest conservation benefit to cost ratio. Setting a minimum restoration threshold for each habitat type allowed me to identify high priority tallgrass prairie sites. The modeling approach is flexible and can be updated for different ecosystems, species, and conservation priorities. I outlined potential alterations that can be made in future analyses, depending on desired restoration goals.
Biodiversity conservation can increase ecosystem functioning and services. In this dissertation, I show that conserving biodiversity is important for urban ecosystem functioning and global carbon sequestration. Restoring biodiversity will have positive outcomes for ecosystem functions, ecosystem services, and people. My restoration prioritization model can therefore be used to implement conservation actions to achieve global and national biodiversity conservation goals and targets
Quadratic Fields Admitting Elliptic Curves with Rational -Invariant and Good Reduction Everywhere
Clemm and Trebat-Leder (2014) proved that the number of quadratic number
fields with absolute discriminant bounded by over which there exist
elliptic curves with good reduction everywhere and rational -invariant is
. In this paper, we assume the -conjecture to show
the sharp asymptotic for this number, obtaining
formulae for in both the real and imaginary cases. Our method has three
ingredients:
(1) We make progress towards a conjecture of Granville: Given a fixed
elliptic curve with short Weierstrass equation for
reducible , we show that the number of integers , , for which the quadratic twist has an integral
non--torsion point is at most , assuming the -conjecture.
(2) We apply the Selberg--Delange method to obtain a Tauberian theorem which
allows us to count integers satisfying certain congruences while also being
divisible only by certain primes.
(3) We show that for a polynomially sparse subset of the natural numbers, the
number of pairs of elements with least common multiple at most is
for some . We also exhibit a matching lower
bound.
If instead of the -conjecture we assume a particular tail bound, we can
prove all the aforementioned results and that the coefficient above is
greater in the real quadratic case than in the imaginary quadratic case, in
agreement with an experimentally observed bias.Comment: 35 pages, 1 figur
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