Alternating Sign Matrices and Hypermatrices, and a Generalization of Latin Square

An alternating sign matrix, or ASM, is a $(0, \pm 1)$-matrix where the nonzero entries in each row and column alternate in sign. We generalize this notion to hypermatrices: an $n\times n\times n$ hypermatrix $A=[a_{ijk}]$ is an {\em alternating sign hypermatrix}, or ASHM, if each of its planes, obtained by fixing one of the three indices, is an ASM. Several results concerning ASHMs are shown, such as finding the maximum number of nonzeros of an $n\times n\times n$ ASHM, and properties related to Latin squares. Moreover, we investigate completion problems, in which one asks if a subhypermatrix can be completed (extended) into an ASHM. We show several theorems of this type.Comment: 39 page

Light Trap Records of \u3ci\u3ePhyllophaga\u3c/i\u3e (Coleoptera: Scarabaeidae) in Wisconsin, 1984-1987

Phyllophaga adults (June beetles) were surveyed from 1984 through 1987 at five locations in Wisconsin using black light traps. Data were collected at each location for three consecutive years. A total of 9,259 specimens representing 13 species were collected during the survey. Species captured, sex ratios, and flight periods for abundant species were recorded for each location. Species abundance differed from previous surveys of Phyllophaga in Wisconsin. Possible reasons for observed shifts in species abundance are discussed

Research on gravitational physiology

The topic of gravitational plant physiology was studied through aspects of plant development (in ARABIDOPSIS) and of behavior (in HELIANTHUS) as these were affected by altered g experience. The effect of increased g levels on stem polarity (in COLEUS) was also examined

OPEC as a Social Welfare Maximizer

We maximize OPEC's social welfare from their oil production including the domestic as well as the export market. For welfare maximization OPEC countries should set domestic oil price equal to the marginal revenues from the oil export market and, therefore, domestic oil price should be lower than the world price. Our base case price leader model yields a 1995 export price of $14.21/bbl (barel) and 27,042 MBPD (thousands of barrels per day) of OPEC exports with a domestic price and quantity of$5.22/bbl and 5,175 MBPD for the base case. However, with competition world oil price should fall dramatically to $6.40 per barrel with OPEC's world market share approaching 70%.

Hidden vortex lattices in a thermally paired superfluid

We study the evolution of rotational response of a hydrodynamic model of a two-component superfluid with a non-dissipative drag interaction, as the system undergoes a transition into a paired phase at finite temperature. The transition manifests itself in a change of (i) vortex lattice symmetry, and (ii) nature of vortex state. Instead of a vortex lattice, the system forms a highly disordered tangle which constantly undergoes merger and reconnecting processes involving different types of vortices, with a "hidden" breakdown of translational symmetry.Comment: 4 pages, 5 figs. Submitted to Physical Review. Online suppl. material available; Ref. 6. V2: Fig. 1 re-sent, URL in Ref. 6 correcte

THE U.S. FERTILIZER INDUSTRY: DEMAND TRENDS AND MARKET STRUCTURE

Agribusiness,

THE U.S. PESTICIDE INDUSTRY: USAGE TRENDS AND MARKET DEVELOPMENT

Agribusiness, Crop Production/Industries,

Effects of prolonged acceleration with or without clinostat rotation on seedlings of Arabidopsis thaliana (L.) Heynh

Three 21-day tests of the effects of chronic centrifugation were carried out on populations of Arabidopsis thaliana. In addition to 1 g the resultant g-forces tested were: 2,4,6,8,16, and 20 g. Observed end points included gross morphological characters such as size of plant organs and, at the other extreme, features of sub-cellular structure and ultrastructure. Plants were grown on banks of clinostats. The acceleration vector was directed either parallel with the plants' axes or transverse to the axes. Plant responses to chronic axial acceleration and to transverse acceleration with clinostated plants were determined. From the data obtained it was possible in some cases: (1) to determine the g-functions of specific plant developmental characters; (2) to extrapolate those functions to the hypothetical value at zero g in order to predict (tentatively) the morphology of a plant grown in space, (3) to describe morphological effects of clinostat rotation, (4) to determine which of those effects was influenced by the prevailing g-force, and (5) to put to direct test the assumption that clinostat rotation nullifies or compensates for the influence of gravity

We Provided Psychological First Aid After the Las Vegas Shooting – Here’s What We Learned.

What is “psychological first aid”? How do mental health experts like you work side by side with traditional first responders? The goal of psychological first aid is to sooth, assist and help people function and cope in a healthy way in the wake of a traumatic event. It’s employed in the hours and days following the event, when people’s immediate needs, including medical care, as well as basic needs like food, shelter and water, must be met, along with their psychological and physical safety needs