Skimmers: Their Development and Use in Coastal Louisiana

The origin, development, and utilization of the skimmer net is reviewed along with other historical shrimp gears used in coastal Louisiana. The skimmer was developed to catch white shrimp, Penaeus setiferus, observed jumping over the cork line (headrope) of trawls being worked in shallow waters. A description of the gear is presented including basic components and various frame designs used by fishermen during its development. The advantages of skimmers over bottom trawls include: multiple use as both trawl and butterfly net (wing net), ease of deployment, increased maneuverability, reduction and greater survivability of bycatch, and ability to cover more area due to increased speed and continuous fishing capability. Disadvantages may include compromising vessel stability when stored upright on the deck, possible damage to water bottoms when improperly rigged, and limitation to a 12-foot (3.6 m) maximum depth due to size restrictions. The growing popularity of the skimmer net is evident by its introduction into North Carolina and inquiries from other southeastern Atlantic and Gulf coast states

Spatial scales of cirrus cloud properties

Research in studying the spatial scales of the cirrus, used data collected during the flight legs of the NCAR Sabreliner aircraft on four days during the FIRE Cirrus IFO to study the spatial scales of the cirrus, and will concentrate on the scales of horizontal wind. The spatial scales of the cloud features can be described by power spectra (or spectral density graphs) and cumulative variance graphs. The cumulative variance graphs were created by first using a Fast Fourier Transform (FFT) to create variance spectra. The variances were then summed in a cumulative fashion from the largest scalelengths (wavelengths) to the smallest. No detrending was done to the original data, and no smoothing or averaging was done to the spectral points. All the spectral points were included. This means that the values of the first five to ten spectral points of the large scalelengths should only be considered to be qualitatively correct. The cumulative variance at smaller scalelengths should be correct because a more accurate representation of the variance at the larger scalelengths should only redistribute the energy amongst the larger scalelengths

Radiative properties of Cirrus clouds: FIRE IFO case October 28, 1986

A description of the radiative properties of two cirrus clouds sampled on 10/28/88 in the FIRE cirrus IFO is presented. The clouds are characterized in terms of the broadband infrared effective emittance, cloud fractional absorptance, shortwave heating rate, cloud albedo and vertical velocity. The broadband fluxes used in these calculations were obtained from measurements made by pyranometers and pyrgeometers. The shortwave irradiances were corrected to a horizontal plane and normalized to the same time by taking into account Sabreliner flight information (i.e., pitch, roll, heading and angle of attack), as well as sun-earth geometry considerations. Since only one aircraft was used, broadband fluxes at different levels in the cloud were not measured simultaneously. As a result, sampling errors may occur due to the nonsteady state of the cloud field or due to the possibility that the flight legs were not flown directly above or below each other. To minimize these errors and to simplify the analysis, the necessary variables were averaged and the averages used in the calculations. The downwelling shortwave and longwave irradiances were used as selection criteria to remove cloud free data encountered along the data sampling leg

Xantusia Vigilis (Desert Night Lizard) and Sceloporus Magister (Desert Spiny Lizard). Predation and Diet.

Here, we report evidence of predation on Xantusia vigilis by Sceloporus magister. We collected a yearling female S. magister (71 mm SVL, mass = 13.6 g) on 24 July 1996, 5 km SE of Llano, Los Angeles County, California, USA (34°29\u27N, 117°46\u27W, elevation 1120 m). In the laboratory, on 29 July, the S. magister deposited a fecal pellet that contained part of a Xantusia vigilis body, including sections of dorsal and ventral integument and both hind limbs

Impact of \u3ci\u3eWheat streak mosaic virus\u3c/i\u3e and \u3ci\u3eTriticum mosaic virus\u3c/i\u3e Coinfection of Wheat on Transmission Rates by Wheat Curl Mites

Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) are transmitted by the wheat curl mite (WCM, Aceria tosichella), and coinfections of wheat by these viruses are common in the field. Previous work has shown that mite genotypes vary in their ability to transmit TriMV. However, the degree to which coinfection of wheat modifies WCM vector competence has not been studied. The objective was to determine whether mite genotypes differed in virus transmission ability when feeding on wheat coinfected by WSMV and TriMV. First, WCM genotype type 2 was used to determine virus transmission rates from mock-, WSMV-, TriMV-, and coinfected wheat plants. Transmission rates were determined by using single-mite transfers from replicated source plants. Coinfection reduced WSMV transmission by type 2 WCM from 50 to 35.6%; however, coinfection increased TriMV transmission from 43.3 to 56.8%. Mite survival on single-mite transfer test plants indicates that the reduction in WSMV transmission may result from poor mite survival when TriMV is present. In a second study, two separate colonies of WCM genotype type 1 were tested to assess the impact of coinfection on transmission. Type 1 mites did not transmit TriMV from coinfected plants but the two colonies varied in transmission rates for WSMV (20.9 to 36.5%). Even though these changes in mite transmission rates are moderate, they help explain the high relative incidence of TriMV-positive plants that are coinfected with WSMV in field observations. These findings begin to demonstrate the complicated interactions found in this mite–virus complex

Spectral variation of scattering and absorption by cirrus

The impact of cirrus clouds on the radiative budget of the earth depends on the microphysics and scattering properties of the clouds. Cirrus clouds have been especially difficult to observe because of their high altitude and complex tenuous structure. Observations by Abakumova et. al. (1991) show that the near infrared wavelengths are more sensitive to the cirrus cloud properties than the shorter ultraviolet wavelengths. Anikin (1991) was able to show that collimated spectral measurements can be used to determine an effective particle size of the cirrus clouds. Anikin (1991) also showed that the effect of scattering through cloud causes the apparent optical depth of a 10 degrees field of view pyrheliometer to be roughly half the actual optical depth. Stackhouse and Stephens (1991) have shown that the existence of small ice crystals do dramatically affect the radiative properties of the cirrus, though observations taken during the 1986 FIRE were not totally explained by their presence

S.V. Petersen se poësie van verwantskap

Die artikel ondersoek met verwysing na enkele protesgedigte ‘n durende spanning in die poësie-oeuvre van S.V. Petersen, naamlik sy verhouding met sy “landgenoot met die ligte vel […] oor wie (hy) wroeg”. Ten aanvang word die ondersoek gerig op aspekte van taalverwantskap, daarna volg vrae oor die vormlike aspekte van sy poësie en laastens kom die verwantskapstema in sy oeuvre aan bod. Die basiese teoretiese aanname berus op Bakhtinaanse insigte en word aangevul met tersaaklike herkonstruktiewe kommentaar op die sosiale omgewing waarin die gedigte ontstaan het. Die vanselfsprekendheid van Petersen se Afrikaanse digterskap word in heroënskou geneem veral omdat die sosiale en politieke omstandighede in die 1940’s daarvoor ongunstig was. Vervolgens word taalregister as ‘n simboliese handeling bespreek waarna in enkele gedigte die ontwikkeling van die verwantskapidee oor die loop van veertig jaar agterhaal word. Dit blyk dat die aanmoediging van dosente en ouer medeskrywers, ‘n simpatieke uitgewery, sy Afrikaanse jeug en bes moontlik Petersen se behoudende politieke ingesteldheid beslag aan sy taalkeuse gegee het, terwyl sy poëtiese beskouing van verwantskap ontwikkel het vanaf vervreemding, gebrokenheid en verwyt tot ontnugtering en by die ouer, ryper digter tot optimisme.nf201

‘To be human again’ : identity, injustice, guilt and restitution in the RSG narrative series Almal het ’n storie

A history of internal division marks the Afrikaans speech community. In the past the Afrikaans language was often claimed as ‘the white man language’, a presupposition that led to the common assertion that it was ‘the language of apartheid’. Much of the politics underlying these historical perceptions involve the expression of Afrikaner nationalism during the 20th century. Since the early 1990s the South African society has undergone fundamental political and social changes, also regarding the Afrikaans language. This article explores an Afrikaans radio series Almal het ’n storie (“Everyone has a story”) that illustrates some of these changes regarding current identity formation and social restitution processes. The article will provide an overview of Almal het ’n storie, followed by brief summaries of the story lines of two selected storytelling performances and a closer analysis of its underlying expressions of identity. A more generalised discussion of identity formation and restitution in the radio series will conclude the paper. To put these matters in overall perspective the identity politics of the Afrikaans language, a background history of the radio station and the series sponsor, an Afrikaans cultural association, and their recent strategic changes will introduce the paper along with an abbreviated overview of restitution as formulated in Elazar Barkan’s The Guilt of Nations: Resititution and Negotiating Historical Injustices (2000).http://www.letterkunde.up.ac.za/am201

Autobiography and memory as resistance in Adam Small's The Orange Earth

The Orange Earth is discussed here as a fictionalised autobiographical account in which the Afrikaans poet and playwright, Adam Small, reflects on the impact of apartheid, creating a counternarrative of a marginalised life during that political system. In the play, presented essentially as a play of ideas, the Coloured main character Johnny Adams, the fictionalised alter ego of the author, plants a bomb that kills a white child and much of the action involves his rationalization of his deed of terror. The play references the cultural and linguistic relationship between Coloured and white Afrikaans-speaking people, and the former's humiliation and exclusion under the apartheid policy. It is argued inter alia that Small's choice of English as a language of literary expression could be interpreted as part of a counterdiscourse on cultural disaffection and political disillusion just as his option of urban violence as a solution to apartheid, his "cry for citizenship", amounts to a desperate act rather than one of revolutionary violence. The article concludes with a discussion on the multiple meanings associated with the title that serves as a metaphor for the countermemory of Small's narrative.http://www.letterkunde.up.ac.za/nf201