The Effective Cone of Moduli Spaces of Sheaves on a Smooth Quadric Surface

Let $\xi$ be a stable Chern character on $\mathbb{P}^1 \times \mathbb{P}^1$, and let $M(\xi)$ be the moduli space of Gieseker semistable sheaves on $\mathbb{P}^1 \times \mathbb{P}^1$ with Chern character $\xi$. In this paper, we provide an approach to computing the effective cone of $M(\xi)$ after showing that it is a Mori dream space for all $\xi$. We find Brill-Noether divisors spanning extremal rays of the effective cone using resolutions of the general elements of $M(\xi)$ which are found using the machinery of exceptional bundles. We use this approach to provide many examples of extremal rays in these effective cones. In particular, we completely compute the effective cone of the first fifteen Hilbert schemes of points on $\mathbb{P}^1 \times \mathbb{P}^1$.Comment: 42 page

Visiting friends and relatives distinguishing between the two groups: The case of Hamilton, New Zealand

Within tourism the term visiting ‘friends and relatives' (VFR) is used with little distinction between the two components of ‘friends' and ‘relatives'. This paper examines the proposition that significant differences exist, and provides evidence of such differences derived from a survey of 763 respondents collected over a four month period. Although these differences are small, they indicate that those visiting friends are more likely to visit bars, night clubs and casinos than relatives; and relatives are more likely to visit gardens. Of particular importance is that specific patterns emerged as to attraction attendance and that age of visitor is perhaps more important than status as a ‘friend' or a ‘relative'. The data comprise both quantitative and qualitative forms. The former are analyzed by utilizing descriptive statistics, while the latter are analyzed using CATPAC software based on the principles of neural network analysis. A conceptual model is suggested to provide an insight into the phenomenon

Purpose (Chapter Two of My Best Advice: Proven Rules for Effective Leadership)

Think about how you spent the past day, week, or even month. Why did you spend it that way? Why did you invest your time the way you did? Did you go to work? Why do you go to work every day? Did you go to your daughter\u27s recital or your son\u27s play? Why? Did you get some exercise? Did you take your partner to lunch? Did you go to the neighborhood barbecue? Why? On the surface, our answers to these questions may be simple: I go to work to make money so I can pay my bills and support a certain lifestyle for my family. I go to my kids\u27 events to support them. I love my partner. I enjoy spending time with my neighbors. There may be deeper drivers for each of these decisions as well

An Occupational Hygiene and Safety Primer, Volume 1

Intended to teach the basic tenets of occupational hygiene and safety to a wide variety of undergraduate college students with quite diverse backgrounds, the information in these volumes is open-sourced from a variety of experts on the subject.https://ohioopen.library.ohio.edu/opentextbooks/1005/thumbnail.jp

An Occupational Hygiene and Safety Primer, Volume 2

Intended to teach the basic tenets of occupational hygiene and safety to a wide variety of undergraduate college students with quite diverse backgrounds, the information in these volumes is open-sourced from a variety of experts on the subject.https://ohioopen.library.ohio.edu/opentextbooks/1006/thumbnail.jp

Establishing an Anti- Icing Program

Establishing an Anti-Icing Program in the City of Mishawaka, Indiana—In this session we go through the City of Mishawaka’s process of establishing an effective anti-icing program over the course of 14 years

Tying Dark Matter to Baryons with Self-interactions

Self-interacting dark matter (SIDM) models have been proposed to solve the small-scale issues with the collisionless cold dark matter (CDM) paradigm. We derive equilibrium solutions in these SIDM models for the dark matter halo density profile including the gravitational potential of both baryons and dark matter. Self-interactions drive dark matter to be isothermal and this ties the core sizes and shapes of dark matter halos to the spatial distribution of the stars, a radical departure from previous expectations and from CDM predictions. Compared to predictions of SIDM-only simulations, the core sizes are smaller and the core densities are higher, with the largest effects in baryon-dominated galaxies. As an example, we find a core size around 0.5 kpc for dark matter in the Milky Way, more than an order of magnitude smaller than the core size from SIDM-only simulations, which has important implications for indirect searches of SIDM candidates.Comment: 5 pages, 2 figures. v2: sections II and III edited heavily for clarity of presentation, changes to figure 2 (halo shape), conclusions unchange