380 research outputs found
International peace activist Supriya Vani talks about her book "Battling injustice"
No full textSupriya Vani, international peace activist and author of "Battling injustice: the stories of 16 women Nobel Peace Laureates," delivers a talk about her book. Vani describes each of the women's accomplishments that made them worthy of winning a Nobel Peace Prize and specifically how they each furthered gender equality and women's rights. Vani also discusses her experiences interviewing the living award recipients and the overall research that went into her book. Vani answers questions from the audience
Maximizing the health benefits of lycopene isomers
No full textLycopene is an acyclic C40 non polar carotenoid found in tomatoes. In nature, the predominant form is the all-trans isomeric form which represents 80-97% of lycopene in tomato and tomato related products. However on consumption of tomato products, >50% of the lycopene is found in the cis isomeric form in the body, thereby implying that the cis isomeric form is the more bioavailable /bioactive form in the human body.
The major objective of our study was to validate the bioactivity of lycopene isomers. Three approaches were used to achieve this goal. 1). An ab initio computational model to study the structure of isomers. 2). Develop a method to isolate isomers. 3). Study antioxidant activity and cellular proliferation activity of isomers in in- vitro condition.
Computational modeling studies showed that lycopene isomers differ in their electronic distribution on the molecules. Cellular Antioxidant Activity (CAA) method showed that cis isomers have higher CAA compared to all-trans isomers.
The cellular proliferation assay known as the MTT assay indicated larger decrease in proliferation of cis isomer treated prostate cancer cells. The anti-inflammatory assay (measures the amount of nitric oxide (NO) produced by mouse macrophages (RAW 264.7)) showed marginal difference in activity between control and isomer treated cells.
Non-thermal processing techniques like High Hydrostatic Pressure (HHP) processing and Pulse Electric Field (PEF) were used to increase the yield of beneficial cis lycopene isomer in the processed product. The results showed an qualitative increase in cis isomer after non-thermal processing.
This study helps us get deeper insights on the activity of cis and all-trans lycopene isomers at a basic molecular level, which correlates to the activity at a chemical and biological level. Non-thermal processing methods like High Hydrostatic Pressure processing and Pulse Electric Field processing methods can cause lycopene isomerization. These can be used as alternative means of processing to get tomato products that can yield health benefits to the consumers.Ph.D.Includes bibliographical referencesby Supriya Varm
Dawn of the dark: unified dark sectors and the EDGES Cosmic Dawn 21-cm signal
No full textWhile the origin and composition of dark matter and dark energy remains unknown, it is possible that they might represent two manifestations of a single entity, as occurring in unified dark sector models. On the other hand, advances in our understanding of the dark sector of the Universe might arise from Cosmic Dawn, the epoch when the first stars formed. In particular, the first detection of the global 21-cm absorption signal at Cosmic Dawn from the EDGES experiment opens up a new arena wherein to test models of dark matter and dark energy. Here, we consider generalized and modified Chaplygin gas models as candidate unified dark sector models. We first constrain these models against Cosmic Microwave Background data from the Planck satellite, before exploring how the inclusion of the global 21-cm signal measured by EDGES can improve limits on the model parameters, finding that the uncertainties on the parameters of the Chaplygin gas models can be reduced by a factor between 1.5 and 10. We also find that within the generalized Chaplygin gas model, the tension between the CMB and local determinations of the Hubble constant H0 is reduced from ≈ 4σ to ≈ 1.3σ. In conclusion, we find that the global 21-cm signal at Cosmic Dawn can provide an extraordinary window onto the physics of unified dark sectors
The Middle Ground: Spatial Planning Under Uncertainty
No full textConventional spatial planning deals with hazards by bouncing back to the pre-existing situation. Intensifying manifestations of climate risk lead to unforeseen cascading effects that often surpass the level of protection offered by this type of approach (e.g. Hurricane Katrina) . In this thesis. spatial planning approach is developed that embraces uncertainties, including potential cascading effects. It provides the potential to bounce forward in space to better cope with a disaster.Critical infrastructure networks (transport, water, energy lines) are interdependent and embedded in space. The proposal spatially understands recovery patterns offered by these networks during a crisis to inform long term growth trajectories of the urban system that can ‘grow with risk’. The principal objective is mainstreaming the role of spatial planning for risk reduction.The research and design draws from quantitative conclusions of engineering, transport and seismic studies in the context of resilience planning. A spatial disaster event chain is proposed based on theories of complex networks and cascading effects. Risks are projected in space to simulate evacuation behavior on road networks using ArcGIS Network Analyst. With spatial reconfiguration as a central aim, ‘urban design’ iterations form a principal research component for an aggregate understanding of risks in space. The test case utilized in the San Francisco Bay which is at risk of a sea level rise by 2100 and is a hotbed of seismic activity.Understanding recovery patterns due to incremental risk on infrastructure helps derive the gradient of spatial vulnerability. This informs the ‘critical web’ of the urban region to reconfigure land management and density distribution. A coherent spatial assessment framework is established to identify the ‘middle ground’ that absorbs intensive growth and vulnerable sites that must transition for better adaptivity.The research highlights lack of cohesion in planning practice to pursue long term implementation strategies such as resilience in land use management, looking beyond building back’ and investing in incremental gain models that grow with risk .It aims to address this vital knowledge gap between engineering simulations and planning in the real world and how we can build a framework to sync them for long range risk reduction.In conclusion, the project acknowledges risk in space and finds ways to sustain life in the light of urgencies.San Francisco Bay-Resilience By Desig
After socialism and dirigisme : which way?
No full textThe author identifies fundamental economic changes in the last 20 years that have influenced the emergence of a new paradigm on economic reform. The new orthodoxy on economic reform emphasizes smaller government, trade liberalization, business deregulation and privatization, macroeconomic austerity, and the role of free markets for resource allocation and growth. After describing diverse country experiences in economic reform, the author summarizes his findings on key aspects of the design of economic reform programs. Shock treatment (as opposed to the gradual approach) requires a strong government with broad social support, as the costs of the policies are paid upfront and the benefits may take time to accrue. If the program involves protracted social hardship, political support will begin to evaporate and pressure will build for a reversal of reform. Important choices must be made about the sequence of macroeconomic adjustment and consolidation and structural reform. Implementing tax reform and converting quotas to tariffs improve the fiscal budget, so they contribute to macroeconomic stabilization. But premature financial liberalization, before the budget is balanced and real interest rates are at a reasonable level, may lead to financial crisis, as happened in Chile in 1982-83. Massive privatization of large-scale firms can have both stabilizing and destabilizing macroeconomic effects, for example. If it means getting rid of loss-making public enterprises, it could save scarce government resources. But if the resulting output and unemployment costs are socially unsustainable, pressure may mount for the government to come to the enterprises'rescue. The shift from an economy with controlled prices to one in which most prices are market-determined generally involves a big hike in price levels. Chile and Mexico illustrate the stubbornness of the inflation that may follow. China, Korea, and Chile represent countries that carried out economic reform under authoritarian governments that postponed political reform to gain political legitimacy from the fruits of consolidated economic reform. In countries where economic and political reform are pursued simultaneously (as in Eastern Europe and Russia), fragile democracies with a fragmented party system and weak social institutions and governments do not provide the most favorable political environment for implementing and consolidating complex and painful economic reforms. Under these conditions, governments are bound to face the dilemma of either postponing economic reform to avert a political crisis or to backslide in democratization to apply painful economic policies - both unsavory choices.Environmental Economics&Policies,Economic Theory&Research,Banks&Banking Reform,Inequality,Achieving Shared Growth
Exact solutions, finite time singularities and non-singular universe models from a variety of Λ(t) cosmologies
No full text Cosmological models with time-dependent [Formula: see text] (read as [Formula: see text]) have been investigated widely in the literature. Models that solve background dynamics analytically are of special interest. Additionally, the allowance of past or future singularities at finite cosmic time in a specific model signals for a generic test on its viabilities with the current observations. Following these, in this work we consider a variety of [Formula: see text] models focusing on their evolutions and singular behavior. We found that a series of models in this class can be exactly solved when the background universe is described by a spatially flat Friedmann–Lemaître–Robertson–Walker (FLRW) line element. The solutions in terms of the scale factor of the FLRW universe offer different universe models, such as power-law expansion, oscillating, and the singularity free universe. However, we also noticed that a large number of the models in this series permit past or future cosmological singularities at finite cosmic time. At last we close the work with a note that the avoidance of future singularities is possible for certain models under some specific restrictions. </jats:p
Political models of macroeconomic policy and fiscal reform
No full textThe author explains how recent developments in political economics improve our understanding of macroeconomic policy - especially the timing, design, and likelihood of stabilization's success through monetary and fiscal reform. The author reviews the literature on political business cycles and emphasizes several issues involving the relationship between the timing of elections and the timing of macroeconomic policies and outcomes. He also addresses how models can be useful in studying non-democratic systems. Two forces are crucial factors in both democratic and dictatorial systems, although they may manifest themselves differently: (1) the policymakers'incentive to retain power; and (2) society's polarization and the degree of social conflict. The author then analyzes why economic stabilization is delayed, even when it is obvious that sooner or later a stabilization program will have to be adopted. Some points made in the paper follow. Certain institutional characteristics make quick and successful stabilization more or less likely. The more unequal the distribution of stabilization's costs, the more likely that stabilization will be delayed. An increase in the cost of postponing stabilization reduces the delay. Political institutions that make it easier for small interest groups to veto legislation make delay more likely. If political and economic resources are unequally distributed, and it is obvious which group is stronger and has resources to wait longer, a war of attrition ends immediately, as there is no uncertainty about who will win it. Delay is more likely when information about who will bear the cost of delays is uncertain or unevenly distributed. Delay is also more likely when there is agreement about the need for fiscal change but a political stalemate about distribution - about how the burden of higher taxes or spending cuts should be allocated. Stabilization usually occurs when there is political consolidation. The burden of stabilization is sometimes unequal, with the politically weaker group (often the lower classes) bearing a larger burden (often regressive measures). If it is in the interest of the current government to do nothing for fear of failure because of government incompetence, the public may have no incentive to vote for the opposition because the opposition may also do nothing; the crucial factor here is how aware the government is of its own incompetence and thus its reasons for not attempting reform. Successful stabilization usually comes after several failed attempts, and the successful program is often very much like one that failed.Environmental Economics&Policies,Economic Theory&Research,National Governance,ICT Policy and Strategies,Health Economics&Finance
Reheating Constraints and the H0 Tension in Quintessential Inflation
No full textIn this work, we focus on two important aspects of modern cosmology: reheating and Hubble constant tension within the framework of a unified cosmic theory, namely the quintessential inflation connecting the early inflationary era and late-time cosmic acceleration. In the context of reheating, we use instant preheating and gravitational reheating, two viable reheating mechanisms when the evolution of the universe is not affected by an oscillating regime. After obtaining the reheating temperature, we analyze the number of e-folds and establish its relationship with the reheating temperature. This allows us to connect, for different quintessential inflation models (in particular for models coming from super-symmetric theories such as α-attractors), the reheating temperature with the spectral index of scalar perturbations, thereby enabling us to constrain its values. In the second part of this article, we explore various alternatives to address the H0 tension. From our perspective, this tension suggests that the simple Λ-Cold Dark Matter model, used as the baseline by the Planck team, needs to be refined in order to reconcile its results with the late-time measurements of the Hubble constant. Initially, we establish that quintessential inflation alone cannot mitigate the Hubble tension by solely deviating from the concordance model at low redshifts. The introduction of a phantom fluid, capable of increasing the Hubble rate at the present time, becomes a crucial element in alleviating the Hubble tension, resulting in a deviation from the Λ-Cold Dark Matter model only at low redshifts. On a different note, by utilizing quintessential inflation as a source of early dark energy, thereby diminishing the physical size of the sound horizon close to the baryon–photon decoupling redshift, we observe a reduction in the Hubble tension. This alternative avenue, which has the same effect of a cosmological constant changing its scale close to the recombination, sheds light on the nuanced interplay between the quintessential inflation and the Hubble tension, offering a distinct perspective on addressing this cosmological challenge
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