A video method for quantifying size distribution, density, and three-dimensional spatial structure of reef fish spawning aggregations

There is a clear need to develop fisheries independent methods to quantify individual sizes, density, and three dimensional characteristics of reef fish spawning aggregations for use in population assessments and to provide critical baseline data on reproductive life history of exploited populations. We designed, constructed, calibrated, and applied an underwater stereo-video system to estimate individual sizes and three dimensional (3D) positions of Nassau grouper (Epinephelus striatus) at a spawning aggregation site located on a reef promontory on the western edge of Little Cayman Island, Cayman Islands, BWI, on 23 January 2003. The system consists of two free-running camcorders mounted on a meter-long bar and supported by a SCUBA diver. Paired video “stills” were captured, and nose and tail of individual fish observed in the field of view of both cameras were digitized using image analysis software. Conversion of these two dimensional screen coordinates to 3D coordinates was achieved through a matrix inversion algorithm and calibration data. Our estimate of mean total length (58.5 cm, n = 29) was in close agreement with estimated lengths from a hydroacoustic survey and from direct measures of fish size using visual census techniques. We discovered a possible bias in length measures using the video method, most likely arising from some fish orientations that were not perpendicular with respect to the optical axis of the camera system. We observed 40 individuals occupying a volume of 33.3 m3, resulting in a concentration of 1.2 individuals m–3 with a mean (SD) nearest neighbor distance of 70.0 (29.7) cm. We promote the use of roving diver stereo-videography as a method to assess the size distribution, density, and 3D spatial structure of fish spawning aggregations

Nassau grouper (Epinephelus striatus) spawning aggregations: hydroacoustic surveys and geostatistical analysis

With the near extinction of many spawning aggregations of large grouper and snapper throughout the Caribbean, Gulf of Mexico, and tropical Atlantic, we need to provide baselines for their conservation. Thus, there is a critical need to develop techniques for rapidly assessing the remaining known (and unknown) aggregations. To this end we used mobile hydroacoustic surveys to estimate the density, spatial extent, and total abundance of a Nassau grouper spawning aggregation at Little Cayman Island, Cayman Islands, BWI. Hydroacoustic estimates of abundance, density, and spatial extent were similar on two sampling occasions. The location and approximate spatial extent of the Nassau grouper spawning aggregation near the shelf-break was corroborated by diver visual observations. Hydroacoustic density estimates were, overall, three-times higher than the average density observed by divers; however, we note that in some instances diver-estimated densities in localized areas were similar to hydroacoustic density estimates. The resolution of the hydroacoustic transects and geostatistical interpolation may have resulted in over-estimates in fish abundance, but still provided reasonable estimates of total spatial extent of the aggregation. Limitations in bottom time for scuba and visibility resulted in poor coverage of the entire Nassau grouper aggregation and low estimates of abundance when compared to hydroacoustic estimates. Although the majority of fish in the aggregation were well off bottom, fish that were sometimes in close proximity to the seafloor were not detected by the hydroacoustic survey. We conclude that diver observations of fish spawning aggregations are critical to interpretations of hydroacoustic surveys, and that hydroacoustic surveys provide a more accurate estimate of overall fish abundance and spatial extent than diver observations. Thus, hydroacoustics is an emerging technology that, when coupled with diver observations, provides a comprehensive survey method for monitoring spawning aggregations of fish

Electron paramagnetic resonance of rutile pigments

An Electron Paramagnetic Resonance study of rutile (TiO(_2)) pigments doped with either iron or chromium has been performed. The spectra of the Cr(^3+) ion has been observed and confirmed by computation. In iron doped pigments a signal with g = 4.28 was observed and has been attributed to the Fe(^3+) ion in a site of rhombic symmetry. The effect of irradiation by light on the Fe(^3*) ion in a substitutional site has been examined and seen to be different from that for single crystal samples ; only wavelengths longer than 700 nm affect it. A light-generated line was observed with 'g' values g(_11) = 2.010, g(_1) = 2.005. The response of this line is related to the concentration of iron. The data has been analysed and correlates reasonably well with accepted models for the positions of the defect centres within the band gap

Editorial

A recurring feature of Studies in Design Education and Craft is the lively, informed and articulate controversy that not only characterises design education but regularly revitalises it. The articles published in this issue are all concerned with one of the central issues in the controversy - the conflict between emphases on creativity and emphases on craft skills. In particular this issue may be seen in the provocative yet highly important contributions by Ashton, Grady and Pugh. Pugh, in a hard-hitting review of the Art College and Polytechnic scene directs himself to the great divide in art education. ";There are fundamental, underlying contradictions at work in art education. On the one hand we have the Art Department which is rigid in traditions such as the perpetuation of old ";skills";, techniques and crafts, with an ostrich headed attitude towards the real problem of visual education; and on the other we have an attempted up-dating of the syllabus by emulating the trendy art gallery scene, turning the students into confused mimetics; they will be searching with the wrong equipment for that elusive"; recognition";. Under this second category art, as such, is treated as being far too precious a subject to withstand any analysis; the artist (or embryo artist) is seduced into thinking that he never really has to justify what he does: the die is cast for another aspect of the mystique."

A Comparative Evaluation of Gait between Children with Autism and Typically Developing Matched Controls

Anecdotal reports suggest children with autism spectrum disorder (ASD) ambulate differently than peers with typical development (TD). Little empirical evidence supports these reports. Children with ASD exhibit delayed motor skills, and it is important to determine whether or not motor movement deficits exist during walking. The purpose of the study was to perform a comprehensive lower-extremity gait analysis between children (aged 5–12 years) with ASD and age- and gender-matched-samples with TD. Gait parameters were normalized to 101 data points and the gait cycle was divided into seven sub-phases. The Model Statistic procedure was used to test for statistical significance between matched-pairs throughout the entire gait cycle for each parameter. When collapsed across all participants, children with ASD exhibited large numbers of significant differences (p \u3c 0.05) throughout the gait cycle in hip, knee, and ankle joint positions as well as vertical and anterior/posterior ground reaction forces. Children with ASD exhibited unique differences throughout the gait cycle, which supports current literature on the heterogeneity of the disorder. The present work supports recent findings that motor movement differences may be a core symptom of ASD. Thus, individuals may benefit from therapeutic movement interventions that follow precision medicine guidelines by accounting for individual characteristics, given the unique movement differences observed

Religiosity and Sexual Risk Behaviors Among Latina Adolescents: Trends from 1995 to 2008

Purpose: The purpose of this study was to determine trends in the influence of religiosity on sexual activity of Latina adolescents in the United States from 1995 to 2008 and to determine if differences existed between the Mexican American and other Latina groups. Methods: The sample comprised the subset of unmarried, 15–21-year-old (mean 17 years) Latina female respondents in the 1995 (n=267), 2002 (n=306), and 2006–2008 (n=400) National Survey of Family Growth (NSFG) datasets. Associations between religiosity (importance of religion and service attendance) and history of ever having sex, number of sex partners, and age of sexual debut were investigated. Results: Less than one half of Latinas in 1995 (44%) and in 2006–2008 (44%) reported that religion was very important to them, whereas in 2002, 50% reported it was important. Only in 1995 did Latinas who viewed religion as very important have a significantly lower level of sexual initiation. In 1995 and in 2006–2008, Latinas who held religion as very important had significantly fewer partners. In all three cohorts, the higher religious importance group had higher virgin survival rates. Across cohorts, approximately one third of respondents reported frequent religious attendance. In all cohorts, frequent attenders were less likely to have had sex, had fewer partners, and had older age at sexual debut. The survival rate as virgins for Mexican origin Latinas was higher in 1995 and 2002 compared to non-Mexican Latinas but was almost the same in 2006–2008. Conclusions: Religiosity had a protective association with sexual activity among Latina adolescents. The association of importance of religion with sexual activity has diminished from 1995 to 2008, however, whereas the importance of service attendance has remained stable. The influence of religion was more apparent among the Latinas of Mexican origin, but this greater influence also diminished by 2006–2008

Dihydropyran Ring Conformations. I. Structures of 2-Methoxy- and 2-Hydroxy-2, 4-dimethyl-3, 4-dihydro-2\u3ci\u3eH\u3c/i\u3e, 5\u3ci\u3eH\u3c/i\u3e-Pyrano[3,2-\u3ci\u3ec\u3c/i\u3e][1]benzopyran-5-ones

Conformations of embedded 3,4-dihydro-2H-pyrans (DHP\u27s) are studied in a closely related series of nine molecular structures, including the cis and trans isomers of both racemic and resolved homologs of 2,4-dimethyl-3,4-dihydro-2H,5H-pyrano[3,2-c][l]-benzopyran-5-one. DHP rings in these structures display a range of conformations near the half-chair form but distorted variously toward each of the two inequivalent d,e- and e,f-diplanar forms. Factor analysis reveals the coordination of torsional motions associated with a principal ring-bending mode based on the various ring conformations. Two methyl ketals and an hemiketal structure are reported. (I): (2S,4S)-cis-2-methoxy, C15H16O4, Mr = 260·30, trigonal, P3221, a = 9·579 (5), c = 24·938 (15) Å (hexagonal axes), V = 1981·7 (33) Å, Z = 6, Dx = 1·309 g cm-3, λ(Mo Kᾱ)= 0·71073 Å, μ = 0·884 cm- 1, F(000) = 828, T = 295 K, R = 0·040 for 1470 observations. (II): (2R,4S)-trans-2-methoxy, C15H16O4, Mr = 260·30, monoclinic, P21, a = 9·254 (4), b = 11·970 (5), c = 12·736 (5) Å, β = 105·64 (4)°, V = 1358·5 (22) Å3, Z = 4 (two molecules per asymmetric unit), Dx = 1·274 g cm-3, λ(Mo Kᾱ) = 0·71073 Å, μ = 0·860 cm-1, F(000) = 552, T = 295 K, R = 0·043 for 2923 observations. (III): (2S,4S)-cis-2-hydroxy, C14H14O4, Mr = 246·27, orthorhombic, P212121, a = 6·816 (3), b = 12·826 (7), c = 13·949 (6) Å, V = 1219·4 (17) Å3 , Z = 4, Dx = 1·340 g cm-3, λ(Mo Kᾱ) = 0·71073 Å, μ= 0·919 cm-1, F(000) = 520, T = 293 K, R = 0·046 for 1291 observations

Structure of (Phenyl)bis( 4-hydroxybenzo-2\u3ci\u3eH\u3c/i\u3e-pyran-2-one-3-yl)methane*

A derivative of dicoumarol, C25H16O6, Mr, = 412·41, orthorhombic, P212121, a = 7·959(2), b = 12·865 (3), c = 18·606 (6) Å, V = 1905·3 (22) Å3, Z = 4, Dx = 1.44 g cm-3, λ(Mo Kα) = 0·71073 Å , μ = 0·965 cm-1, F(000) = 856, T = 293 K, final R = 0·042 for 2031 observations. The 4-hydroxycoumarins are intramolecularly hydrogen bonded between hydroxyls and carbonyls, O···O separations are 2·624 (3) and 2·718 (3)Å, a scheme which imparts a dis-symmetry to the otherwise achiral molecule and underlies packing in a polar space group