Counting Bitangents with Stable Maps

This paper is an elementary introduction to the theory of moduli spaces of curves and maps. As an application to enumerative geometry, we show how to count the number of bitangent lines to a projective plane curve of degree $d$ by doing intersection theory on moduli spaces.Comment: expository- soft introduction to working with moduli. Many pictures. To appear on Expositiones Mathematica

Intellectual property rights, private investment in research, and productivity growth in Indian agriculture: A review of evidence and options

With the growth of private investment in developing-country agriculture, new advances in the biological sciences, and rapid integration of developing countries into the global trading system, intellectual property rights (IPRs) have become an important concern for policymakers, corporate decisionmakers, and many other players in the agricultural sector. But there are still unanswered questions about whether emerging and evolving IPR regimes in developing countries will contribute to increasing agricultural productivity and improving food security. This paper attempts to answer some of these questions by tracing the effects of IPRs on private investment in crop genetic improvement and, in turn, on agricultural productivity. The paper focuses specifically on the case of India, the regional leader in implementing IPRs in agriculture. Findings indicate that maize and pearl millet yields grew significantly during the last two decades due to the combination of (1) public policies that encouraged private investment in India's seed industry during the 1980s, (2) public investment in hybrid breeding programs that generated new materials offering substantial yield gains, and (3) biological IPRs conferred by hybridization that conveniently married the private sector's need for appropriability with the nation's need for productivity growth. Although past lessons are not an indication of future success, this convergence of policy solutions and technology opportunities can be replicated for other crops that are vital to India's food security.Agricultural productivity, agricultural research and development, food security, Intellectual property rights,

The seed and agricultural biotechnology industries in India: An analysis of industry structure, competition, and policy options

Since the late 1980s, technological advances and policy reforms have opened up new opportunities for growth in India's seed and agricultural biotechnology industries. The impacts of such changes have been significant in India's cotton sector, but less so for the country's main cereal crops, where both yield and output growth rates have been relatively stagnant. Some public policymakers and corporate decisionmakers are confident that the private sector will help reverse these trends, arguing that the right combination of new technological solutions and progressive policy reforms will unleash a significant increase in private investment in productivity-enhancing products and services. The structure of India's seed and agbiotech industries, as well as the policies designed to support their growth, will be a significant determinant of this expected impact. This paper examines the structure of India's cereal seed and agbiotech industries, its potential effects on innovation and social welfare, and the policies that may improve both industry performance and the delivery of new technologies to resource-poor, small-scale farmers in India's cereal production systems. We focus our analysis on indicators and scenarios within India's agricultural innovation market for improved seed and agricultural biotechnology products. This market includes firms engaged in the development, commercialization, and marketing of new seed-based technologies; it is characterized by a high level of knowledge intensity, relatively high levels of R&D investment, significant barriers to entry, significant levels of regulation, and relatively few products in the market. And it is within this market that factors such as strategic corporate behavior and public policy can affect the balance between a socially desirable rate of innovation, on the one hand, and a socially desirable distribution of the gains from innovation among consumers, farmers, and innovators, on the other hand.Seed markets, Agricultural biotechnology, industrial organization, Cereal crops,

Smart logistics and the logistics operator 4.0

The advent of the Fourth Industrial Revolution is expected to deeply change several aspects of the manufacturing industry. Among them, the logistics and supply chain activities will be affected by these changes both at operational and managerial level to face the market drivers of flexibility and mass-customisation. In this context, the work of operators in internal and external logistics will be affected by these changes and increase the interaction between humans and machines. The evolution of the roles of humans in Logistics 4.0 will give birth to "The Logistics Operator 4.0"paradigm. The aim of this paper is to investigate the impacts of Industry 4.0 technologies on the different roles of logistics operators that work in the main logistics domains and areas

Experimental study of turbulent-jet wave packets and their acoustic efficiency

This paper details the statistical and time-resolved analysis of the relationship between the near-field pressure fluctuations of unforced, subsonic free jets (0.4 ≤ M ≤ 0.6) and their far-field sound emissions. Near-field and far-field microphone measurements were taken on a conical array close to the jets and an azimuthal ring at 20∘ to the jet axis, respectively. Recent velocity and pressure measurements indicate the presence of linear wave packets in the near field by closely matching predictions from the linear homogenous parabolized stability equations, but the agreement breaks down both beyond the end of the potential core and when considering higher order statistical moments, such as the two-point coherence. Proper orthogonal decomposition (POD), interpreted in terms of inhomogeneous linear models using the resolvent framework allows us to understand these discrepancies. A new technique is developed for projecting time-domain pressure measurements onto a statistically obtained POD basis, yielding the time-resolved activity of each POD mode and its correlation with the far field. A single POD mode, interpreted as an optimal high-gain structure that arises due to turbulent forcing, captures the salient near-field–far-field correlation signature; further, the signatures of the next two modes, understood as suboptimally forced structures, suggest that these POD modes represent higher order, acoustically important near-field behavior. An existing Green's-function-based technique is used to make far-field predictions, and results are interpreted in terms of POD/resolvent modes, indicating the acoustic importance of this higher order behavior. The technique is extended to provide time-domain far-field predictions

The Impact of COVID-19 Lockdown Announcements on Mental Health: Quasi-Natural Experiment in Lombardy, Italy

Background: Evidence showed that mental health problems have risen markedly during COVID-19. It is unclear if part of the mental sufferings relates to the climate of uncertainty and confusion originated by rough communication by health officials and politicians. Here we test the impact of unanticipated policy announcements of lockdown policies on mental health of the older population. Methods: We used a representative telephone-based survey of 4,400 people aged 65\u2009years or older in Italy's Lombardy region to compare information on self-reported symptoms of anxiety, depression, and poor-quality sleep of subjects interviewed on the days of policy announcement with that of subjects interviewed on other days. We used regression models adjusting for potential socio-demographic confounders as well study design with inverse probability weighting. Results: On days when policy makers announced to extend the lockdown, mental health deteriorated on average by 5.5 percentage points [95% CI: 1.1 to 9.8] for self-reported anxiety symptoms and 5.1 percentage points [95% CI: 2.7 to 7.4] for self-reported depressive symptoms. The effect of announcement to shorten the lockdown is more moderate but statistically significant. These associations were short term in duration; after just one day, self-reported mental health and sleep quality return to levels better than pre-announcement until a new policy change. Conclusions: Our research shows that lockdown policy announcements are associated with short term worsening in mental distress, highlighting the importance of appropriate communication strategies and political determinations in crisis times

Older Adults' Access to Care during the COVID-19 Pandemic: Results from the LOckdown and LifeSTyles (LOST) in Lombardia Project

: The COVID-19 pandemic disproportionally affected older people in terms of clinical outcomes and care provision. We aimed to investigate older adults' changes in access to care during the pandemic and their determinants. We used data from a cross-sectional study (LOST in Lombardia) conducted in autumn 2020 on a representative sample of 4400 older adults from the most populated region in Italy. Lifestyles, mental health, and access to healthcare services before and during the pandemic were collected. To identify factors associated with care delays, reduction in emergency department (ED) access, and hospitalisations, we estimated prevalence ratios (PR) and 95% confidence intervals (CI) using multivariable log-binomial regression models. During the pandemic, compared to the year before, 21.5% of the study population increased telephone contacts with the general practitioner (GP) and 9.6% increased self-pay visits, while 22.4% decreased GP visits, 12.3% decreased outpatient visits, 9.1% decreased diagnostic exams, 7.5% decreased ED access, and 6% decreased hospitalisations. The prevalence of care delays due to patient's decision (overall 23.8%) was higher among men (PR 1.16, 95% CI 1.05-1.29), subjects aged 75 years or more (PR 1.12, 95% CI 1.00-1.25), and those with a higher economic status (p for trend < 0.001). Participants with comorbidities more frequently cancelled visits and reduced ED access or hospitalisations, while individuals with worsened mental health status reported a higher prevalence of care delays and ED access reductions. Access to care decreased in selected sub-groups of older adults during the pandemic with likely negative impacts on mortality and morbidity in the short and long run

Laboratory experiments on the interaction of a buoyant coastal current with a canyon : application to the East Greenland Current

Author Posting. © American Meteorological Society, 2009. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 39 (2009): 1258-1271, doi:10.1175/2008JPO4028.1.This paper presents a set of laboratory experiments focused on how a buoyant coastal current flowing over a sloping bottom interacts with a canyon and what controls the separation, if any, of the current from the upstream canyon bend. The results show that the separation of a buoyant coastal current depends on the current width W relative to the radius of curvature of the bathymetry ρc. The flow moved across the mouth of the canyon (i.e., separated) for W/ρc > 1, in agreement with previous results. The present study extends previous work by examining both slope-controlled and surface-trapped currents, and using a geometry specific to investigating buoyant current–canyon interaction. The authors find that, although bottom friction is important in setting the position of the buoyant front, the separation process driven by the inertia of the flow could overcome even the strongest bathymetric influence. Application of the laboratory results to the East Greenland Current (EGC), an Arctic-origin buoyant current that is observed to flow in two branches south of Denmark Strait, suggests that the path of the EGC is influenced by the large canyons cutting across the shelf, as the range of W/ρc in the ocean spans those observed in the laboratory. What causes the formation of a two-branched EGC structure downstream of the Kangerdlugssuaq Canyon (68°N, 32°W) is still unclear, but potential mechanisms are discussed.This work was partially funded by NSF Grant OCE-0450658. DS also received support from the Academic Programs Office of the Woods Hole Oceanographic Institution, while CC had partial support from NSF OCE-0350891

Final Design and On-Sky Testing of the iLocater SX Acquisition Camera: Broadband Single-Mode Fiber Coupling

Enabling efficient injection of light into single-mode fibers (SMFs) is a key requirement in realizing diffraction-limited astronomical spectroscopy on ground-based telescopes. SMF-fed spectrographs, facilitated by the use of adaptive optics (AO), offer distinct advantages over comparable seeing-limited designs, including higher spectral resolution within a compact and stable instrument volume, and a telescope independent spectrograph design. iLocater is an extremely precise radial velocity (EPRV) spectrograph being built for the Large Binocular Telescope (LBT). We have designed and built the front-end fiber injection system, or acquisition camera, for the SX (left) primary mirror of the LBT. The instrument was installed in 2019 and underwent on-sky commissioning and performance assessment. In this paper, we present the instrument requirements, acquisition camera design, as well as results from first-light measurements. Broadband single-mode fiber coupling in excess of 35% (absolute) in the near-infrared (0.97-1.31{\mu}m) was achieved across a range of target magnitudes, spectral types, and observing conditions. Successful demonstration of on-sky performance represents both a major milestone in the development of iLocater and in making efficient ground-based SMF-fed astronomical instruments a reality.Comment: 18 pages, 17 figures. Accepted for publication in MNRA