Four new species of Acoma Casey, with a key to species in the genus (Coleoptera: Scarabaeidae: Melolonthinae)

Acoma howdenorum, Acoma westcotti, Acoma quadrilaminata, and Acoma cimarron (Coleoptera: Scarabaeidae: Melolonthinae), all new species, are described from Yuma County, Arizona, USA, and Baja California Sur, Baja California (Norte), and Sonora, Mexico, respectively. Habitus of the four new species is illustrated, and an updated key to the described species in the genus is provided. Distribution and variation of Acoma glabrata Cazier are also discussed

Aggregate Price Effects of Institutional Trading: A Study of Mutual Fund Flow and Market Returns

We study the relation between market returns and aggregate flow into U.S. equity funds, using daily flow data. The concurrent daily relation is positive. Our tests show that this concurrent relation reflects flow and institutional trading affecting returns. This daily relation is similar in magnitude to the price impact reported for an individual institution's trades in a stock. Aggregate flow also follows market returns with a one-day lag. The lagged response of flow suggests either a common response of both returns and flow to new information, or positive feedback trading.

Disclination-mediated thermo-optical response in nematic glass sheets

Nematic solids respond strongly to changes in ambient heat or light, significantly differently parallel and perpendicular to the director. This phenomenon is well characterized for uniform director fields, but not for defect textures. We analyze the elastic ground states of a nematic glass in the membrane approximation as a function of temperature for some disclination defects with an eye towards reversibly inducing three-dimensional shapes from flat sheets of material, at the nano-scale all the way to macroscopic objects, including non-developable surfaces. The latter offers a new paradigm to actuation via switchable stretch in thin systems.Comment: Specific results for spiral defects now added. References to Witten, Mahadevan and Ben Amar now added

Four new Aphodius Illiger from pocket gopher burrows in Arizona, Utah, Kansas and Nebraska (Coleoptera: Scarabaeidae: Aphodiinae)

We describe four new species of winter-active Aphodius (sensu lato) from pocket gopher burrows in Arizona, Utah, Kansas, and Nebraska: A. cacabatus, A. paulseni, A. skillmani, and A. utopensis. Diagnostic characters of all four species are illustrated

A revision of the genus Gymnetina Casey, 1915 (Coleoptera: Scarabaeidae: Cetoniinae: Gymnetini)

The genus Gymnetina Casey (Coleoptera: Scarabaeidae: Cetoniinae: Gymnetini) is redescribed and revised. Three new species and one new subspecies are described: G. borealis Warner and Ratcliffe, G. grossepunctata Ratcliffe and Warner, G. howdeni Warner and Ratcliffe, and G. cretacea sundbergi Warner and Ratcliffe. Gymnetina salicis (Bates), new status, is removed from synonymy with G. cretacea (LeConte), and G. alboscripta (Janson) is transferred from Gymnetis MacLeay to Gymnetina becoming Gymnetina alboscripta (Janson), new combination. Redescriptions of previously known species, a key for identification, and illustrations of the six species are provided. A brief biogeographical analysis suggests that ancestral taxa dispersed northwards from Guatemala and Mexico to the southwestern United States

The environmental analysis of helicopter operations by Federal agencies: Current procedures and research needs

The technical, economic, and environmental problems restricting commercial helicopter passenger operations are reviewed. The key considerations for effective assessment procedures are outlined and a preliminary model for the environmental analysis of helicopters is developed. It is recommended that this model, or some similar approach, be used as a common base for the development of comprehensive environmental assessment methods for each of the federal agencies concerned with helicopters. A description of the critical environmental research issues applicable to helicopters is also presented

High Speed Photometry of SDSS J013701.06-091234.9

We present high speed photometry of the Sloan Digital Sky Survey cataclysmic variable SDSS J013701.06-091234.9 in quiescence and during its 2003 December superoutburst. The orbital modulation at 79.71\pm0.01 min is double humped; the superhump period is 81.702\pm0.007 min. Towards the end of the outburst late superhumps with a period of 81.29\pm0.01 min were observed. We argue that this is a system of very low mass transfer rate, and that it probably has a long outburst interval.Comment: 5 pages, 8 figures. Accepted for publication in MNRA