A New Analysis Method for Reconstructing the Arrival Direction of TeV Gamma-rays Using a Single Imaging Atmospheric Cherenkov Telescope

We present a method of atmospheric Cherenkov imaging which reconstructs the unique arrival direction of TeV gamma rays using a single telescope. The method is derived empirically and utilizes several features of gamma-ray induced air showers which determine, to a precision of 0.12 degrees, the arrival direction of photons, on an event-by-event basis. Data from the Whipple Observatory's 10 m gamma-ray telescope is utilized to test selection methods based on source location. The results compare these selection methods with traditional techniques and three different camera fields of view. The method will be discussed in the context of a search for a gamma-ray signal from a point source located anywhere within the field of view and from regions of extended emission.Comment: 24 pages, 16 figures, accepted for publication in Astroparticle Physics May 11, 200

Children's working understanding of the knowledge gained from seeing and feeling

In three Experiments, (N = 48 3- to 4-year olds; 100 3- to 5-year olds; 54 4-yearolds), children who could see or feel a target toy, recognized when they had sufficient information to answer “Which one is it?” and when they needed additional access. They were weaker at taking the informative modality of access when the choice was between seeing more of a partially visible toy and feeling it; at doing so when the target was completely hidden; and at reporting seeing or feeling as their source of knowledge of the target’s identity having experienced both. Working understanding of the knowledge gained from seeing and feeling (identifying the target efficiently) was not necessarily in advance of explicit understanding (reporting the informative source)

Taxonomic status of the melanistic forms of the Cordylus cordylus complex (Reptilia: Cordylidae) in the south-western Cape, South Africa

The taxonomic status of the two melanistic morphotypes belonging to the Cordylus cordylus complex in the south-western Cape, South Africa, is considered. It is proposed that the coastal melanistic form, previously described as subspecies of C. cordylus,be considered a separate species, while the previously unknown montane melanistic form is also described as a new species. Areas of uncertainty, which may affect the status of the two melanistic species in the future, are discussed

Cordylus Minor: A valid species of South african lizard (Reptilia: Cordylidae)

The taxonomic status of Cordylus cordylus minor FitzSimons 1943 is reconsidered. An analysis of variation in external morphological characters shows  minor and cordylus to be two non-overlapping sets of organisms. A phylogenetic study shows the minor-cordylus set to be non-monophyletic, leaving no option than to consider minor a separate species

Reproduction and sexual dimorphism in the montane viviparous lizard, Pseudocordylus capensis (Sauria: Cordylidae)

Pseudocordylus capensis, a melanistic lizard, is regarded as a basal species in the phylogeny of the family Cordylidae and is endemic to the Cape Fold Mountains. Data for this study were obtained from measurements and dissections of museum specimens (N = 68). Sexual maturity in both sexes is attained at around 80-90 mm snout-vent length (SVL). Body sizes (SVL) differed significantly between sexes, the mean SVL of adult males being 92.3 mm (range 78.4−104.2) and that of adult females 95.9 mm (range 83.1-108.5). Although the rate of increase in head measurements did not differ significantly between sexes, analysis of covariance (ancova) indicated that head dimensions are marginally, but significantly, larger in males than in females of equivalent SVL. The slight female-plus dimorphism in SVL and male-plus dimorphism in head dimensions is suggested to be related to life in the cold montane environment, and to differential growth to increase female reproductive fitness, rather than to be the result of sexual selection. Males exhibit testicular recrudescence during autumn, with full spermiogenesis during winter maintained through spring (October). The testicular cycle shows characteristics of both ‘post-nuptial’ and ‘pre-nuptial’ cycles previously described in Cordylidae lizards. Small testicular volume, associated with testicular regression, was recorded during summer (November/December). Spermatozoa were present in the epididymis from May through to October. In synchrony with the spermatogenic cycle, the onset of vitellogenesis in females starts in autumn, culminating in ovulation during spring (September-October). Females are gravid during summer and give birth to 2-3 young in late summer (December-January). The timing of events during the reproductive cycle of females corresponds to the autumn cycles reported for all other female Cordylidae lizards studied to date, therefore pointing to strong conservatism regarding the timing of female reproductive cycles in this lizard family. Fatbody size in individuals of both sexes is largest during late summer and autumn, and progressively declines during winter to reach smallest sizes during the summer months. The fact that this phylogenetically basal species exhibits well-synchronised male and female autumn gonadal cycles adds to the data that suggest these reproductive traits evolved during the early divergence from the Cordyliformes ancestor and that the evolution of viviparity may be linked to this event or followed soon after

Morphological variation in the girdled lizard Cordylus mclachlani Mouton 1986

The girdled lizard Cordylus mclachlani, previously known only from the type locality in the south-western Cape, South Africa, was found at several new localities as far north as Nieuwoudtville. The external morphology of the 32 additional specimens thus obtained was investigated to establish the nature of geographical variation. Specimens from the type locality, which lies on the southern periphery of the known distribution range, differ from the rest in the number of suboculars, the shape of the interparietal scale and in the presence of a post-interparietal scale. Because of some overlap in these characters, separate taxonomie status for the specimens outside the type locality is not considered. The diagnostic character set for the species is updated and additional ecological information is supplied

Sexual dimorphism in two girdled lizard species, Cordylus niger and Cordylus cordylus

The extent of sexual selection in two girdled lizard species was evaluated by measuring sexual dimorphism in those characters normally affected by sexual selection. Neither Cordylus niger, a cool-adapted species, nor C. cordylus, a warm-adapted species, displayed any notable sexual differences in asymptotic body sizes, but both species displayed slight dimorphism in head size measurements. The C. niger sample contained more large males than large females, which may be attributed to a lower growth rate in females. In the cool Saldanha area, females of both species lack generation glands. In the warmer Gansbaai area, these glands are present in females of C. cordylus, but in lower numbers than in males. Sex ratios favouring females, have been recorded for both species. The observed sexual dimorphism in the two species seems to be mainly the result of differential energy allocation by females, and not of sexual selection perse

TREND IN TUNA LANDINGS BY THE LONGLINE FISHERY OPERATING OUT ON BENOA, BALI

The number of longline vessels operabing out of Port of Benoa, Bali has increased steadily since 1986. However, this increase has been more rapid since 1994, and in 1996 there were 528 vessels registered in the port