Aid Of Photographs Research Articles

Bioerosion of corals and the influence of damselfish territoriality: A preliminary study.

Samples of the staghorn coral Acropora were taken from within territories defende by damselfish (Pisces: Pomacentridae) and from undefended areas. The fish utilized in this experiment were Hemiglyphidodon plagiometopon Bleeker and Pomacentrus bankanensis Bleeker. The extent of bioerosion was determined by randomly selecting pieces of coral substrate from treatment and control areas, cutting transverse sections, and determining total eroded area with the aid of enlarged photographs. Boreholes within the photos were traced with a digitizing sensor and area was integrated with the aid of a computer.Corals inside territoties were significantly more bioeroded (p<0.001) than corals outside areas. Most of the destruction was caused by boring sponges (Cliona sp.) and sipunculids (Cleosiphon). It is suggested that bioerosion is accelerated within territories as a result of reduction in grazing by fish.

Colposcopic differential diagnosis of dysplasia, carcinoma in situ and microinvasive carcinoma of the cervix.

Two hundred and twenty-eight patients with cervical neoplasia, detected in routine uterine cancer screening at the Center for Adult Diseases, Osaka, from 1973 through 1977 were selected. The histological diagnosis was as follows: dysplasia, 69; carcinoma in situ, 102; and microinvasive carcinoma, 57. A retrospective study of this material was made with the aid of adequate colposcopic colour photographs, and features likely to be useful in differential diagnosis were determined. Atypical vessels were seen in 24 of 36 patients (67%) with Stage Ia1 lesions, but only in a few of those with Stage 02 lesions. Punctation, mosaic and white epithelium were less evident in stage Ia2 than in Stage 01 and Stage 02. Punctation, mosaic and white epithelium in patients with dysplasia were less formed, and their borders were less distinct than in patients with Stage 0 lesions. These characteristic changes are of value in accurate colposcopic diagnosis.

Duck Nesting in Retired Croplands at Horicon National Wildlife Refuge, Wisconsin

Duck Nesting in Retired Croplands at Horicon National Wildlife Refuge, Wisconsin

Morphology and land systems of a part of visakhapatnam district, Andhra Pradesh from air photo studies

Landforms in an area of 1667 sq.km in Visakhapatnam district of Andhra Pradesh along the east coast of India has been mapped with the aid of aerial photographs. Simultaneously the current land use has been noted and the data collected in the field of the nature of surficial deposits, drainage and erosion. An attempt is made to classify the area into land systems designated as (1) hill and hillocks, (2) rolling plains, (3) fluvial plain and (4) coastal zone and give details of their characteristic features. Recommendations are made for better landuse of some of the areas taking into consideration the knowledge of their total potential.

Explorations of the apparent Weissenberg effect in water

The puzzling phenomenon in which water is observed to suddenly climb partially up a vertical rotating shaft whose tip was initially just in contact with the free surface is explored. This phenomenon occurs when the rotational rate is increased above a certain threshold. In an attempt to make some progress on understanding the phenomenon, it is explored by detailed observations and by varying parameters of the problem. Observations are presented with the aid of photographs of the surface waves and of tracer particle path elements. The effect of varying the shaft diameter, immersion of depth of the shaft tip into the water, and the effect of varying some fluid properties are investigated. In addition, extraneous effects such as irregularities in the driving mechanism and shaft, external disturbances of the fluid, and vessel size are eliminated as possible causes of the phenomenon. Despite these explorations of characteristics of the phenomenon, we have not found a satisfactory explanation of it. Another interesting instability was also observed. The water near the fluid surface in the undisturbed state flows radially outward in a regulary laminar fashion. However, small disturbances of the fluid can cause shedding of vortices whose axes are in the tangential direction and which are swept outward.

Environmental public preferences as obtained by the method of photointerpretation in the Ljubljana region

Our knowledge in the field of environmental public preferences is based largely on public opinion, obtained by the use of interviews or questionnaires without pictorial presentation of the real situations in the cities or countryside. This shortcoming can be overcome largely by the method of interviewing with the aid of panoramic photographs. In this research, which because of its sample size has only an indicatory value, a pilot sample of the citizens of Ljubljana was interviewed using photographs of the city and its surroundings. Each person marked on the photographs those sites which corresponded best or worst to the questions. Thus the locational preferences regarding new housing, recreation, landscape preservation, urban renewal, etc., were examined. The answers did not differ very widely, showing very active public participation in this research. People expressed interest in the individual housing locations in the green neighbourhoods, in landscape protection, in the visual improvement of the city, in the concentration of the development within certain sites, etc. A large gap between the wishes of the individual and the public good has been demonstrated clearly: people would like to build their houses on the same sites they would, on the other hand, protect for public recreation. The research has an indicatory and methodological value showing the possibilities of photo-interpretation in urban planning and social sciences; the results of the research have to be confirmed by a representative sample both of photodocumentation and of the population interviewed.

Classification of aneurysms of the internal carotid system.

Microsurgery has improved the treatment of cerebral aneurysms techically and by more detailed knowledge of the topographic relations, the variations, and the anomalies of the involved arteries. A personal study of 450 aneurysms formed the basis of a modified and more detailed classification of aneurysms of the carotid system. It was confirmed that aneurysms originate at the junctions of arteries, and generally project according to the course of the vessel involved. The origins and projections aneurysms and their different sites were analyzed with the aid of angiography, angiotomography, magnification angiography, operative drawings, photographs, and films, which permitted the establishment of a special classification for every particular form. Preoperative knowledge of the types of aneurysms facilitates the surgical procedures and results in lowered morbidity.

Factors affecting the detection of slope instability with air photographs in an area near Sevenoaks, Kent

Summary Twenty-six sets of air photographs were used to test the best photographic conditions for detecting landslips, mainly old periglacial solifluction movement, along a ten mile stretch of sloping ground. A total of 141 old landslip features were detected and many varied in clarity on the different photographs, some being hard or impossible to detect on foot without the aid of air photographs. The repeated images of the same landslips on different sets of photographs produced a total of 2 715 photo-features for statistical studies. Analysis of the results showed that the best technical photographic conditions for detecting such features are the use of infra red colour film, stereoscopic photography with a short focal length lens, a nominal photographic scale of about 1:5 000, and a sun angle that casts local but not very extensive shadows. It is considered that automatic dodging can both enhance and suppress vital information on images, and that the best seasons for photography are likely to be spring and late summer to early autumn.

Plant communities on permanent plots of the serengeti plains

During 1972 the vegetation mosaic within five plots located representatively within the Serengeti Plains (Serengeti National Park, Tanzania) was described by the Z:urich-Montpellier method and mapped with the aid of aerial photographs. Two plots, in the northwestern Serengeti Plains, belong to thePennisetum mezianum-grassland type. The vegetation mosaic of these plots (comprising four and five vegetation units respectively) is marked by rapid changes over short distances in species composition, height and degree of cover of the herb layer. Two plots in the central Serengeti Plains are dominated by a low dense cover ofAndropogon greenwayi-grassland. These plots show heterogeneity in soil conditions and a marked vegetation mosaic comprising three and four vegetation units respectively on the basis of varying responses of the leading species. One plot in the southeastern Serengeti Plains, which is dominated bySporobolus verdcourtii-grassland, is relatively homogenous. Only two vegetation units were distinguished here. Chemical analysis shows that soil factors influence the occurrence of vegetation zones over large areas as well as the pattern of the vegetation mosaic within the relatively small study plots. The Serengeti Plains are characterized by a northwest-southwest gradient of environmental factors which control soil conditions. High rainfall and thin deposits of volcanic tuffs influence soil characteristics which supportPennisetum mezianum-grassland. The soil ofSporobolus verdcourtii-grassland, however, is influenced by low rainfall and thick deposits of volcanic tuffs which have high levels of salinity and alkalinity. These broadly defined site conditions show correspondingly different levels of carbon and nitrogen. The influence of these two chemical factors is also reflected in the nature of vegetation mosaic within each study plot. It is possible to ecologically classify the plant species into six groups based on nutrient requirement levels. These groups can be used as indicators for nutrient supply as well as for general chemical conditions of the soils of the plant communities which were studied.

Optimum Conditions for Contact Lens Patient Instruction*

Teaching patients the correct methods of lens usage is one of the cornerstones of successful contact lens practice, and for a practitioner to be confident that a patient will carry out instruction faithfully, the instruction needs to be as thorough and complete as possible. This facet of practice involves a heavy bias toward art, rather than science, and each practitioner has an individual approach, and a variety of different techniques and innovations have been conceived and used by individual practitioners. However, little attention has been given to a critical examination of the task in this special area of instruction, so, in this paper, a detailed analysis of the task is undertaken. The results highlight many special problems that are involved in this particular teaching situation. A theoretical design of the optimum conditions for the instruction of contact lens patients has been developed, and its practical aspects considered, in particular, the use of printed material, various forms of photographic and other visual aids, special consulting room facilities and optometric assistants.

Remote Sensing for Identification and Classification of Wetland Vegetation

Multispectral photography and ground truth were obtained on an area 12 miles (19.3 km) east of Bemidji, Minnesota, to identify and map wetlands less than 2 acres (0.8 hectare) in size, to map emergent vegetation in lakes, and to explore the feasibility of classifying vegetation from aerial photographs. Wetlands less than 2 acres in size were identified on photography taken in May 1971, and emergent vegetation was recorded on purposely overexposed infrared black and white photography from a flight in September 1971. Several vegetation types and species groups were recognizable with the aid of color, color infrared, and black and white infrared photography. Proper timing of flights, use of multispectral photography, and knowledge of the ecology of the area are considered essential for wetland mapping by remote sensing. J. WILDL. MANAGE. 38(2):308-314 Investigations of the ecology of birds and other wildlife usually require data on the area of and types of habitat available to the animals. Measurements of habitat made from ground surveys are often time-consuming and, therefore, must be restricted to relatively small areas. Remote sensing is a relatively new tool, which, when used in conjunction with ground surveys, enables the ecologist to rapidly survey large areas of land and water, and discover details that are not readily apparent from ground surveys (Colwell 1967). For years, foresters have made extensive use of remote sensing for timber management and inventory (Avery 1968), but work on aquatic habitats has been more restricted. Studies by Kelly and Conrod (1969), Lukens (1968), Cameron (1950), Zohari et al. (1955), Mathisen (1966), Olson (1964), Nelson et al. (1970), and Work and Gilmer (1973) have demonstrated that remote sensing has great promise for wetland mapping and inventory. Recently many investigators have had considerable success in recognizing wetland plant communities and even plant species with the aid of color and color infrared films (Anderson 1968, Anderson 1969, Thompson 1972, Russell and Wobber 1972, Reimold et al. 1973, Seher and Tueller 1973). We required detailed habitat maps for a long-term investigation of waterfowl ecology in Minnesota (Gilmer et al. 1973). Preliminary maps were prepared from ground surveys and from 1:15,840 infrared summer photography obtained from the U.S. Forest Service, but difficulty was experienced in distinguishing small wetlands under the canopy of a hardwood forest. Vegetation in lakes was difficult to map either from a boat or with the aid of aerial photographs. This report considers the use of multispectral photography: (1) to find and map wetlands less than 2 acres in size (minimum size mapped by Mathisen [1966]) under a forest canopy, (2) to accurately map stands of emergent vegetation in lakes, and (3) to explore the feasibility of using multispectral photography to classify wetlands.

CONSTRUCTION OF RIO COLORADO BRIDGE

Describes the construction of a 480-ft long precast, post-tensioned concrete, inverted suspension bridge which was recently constructed near San Jose, Costa Rica. This functional and economically built bridge shows how, with some ingenuity, the principles of suspension, arch, and cantilever theory can be applied with relatively simple construction techniques to span a deeply inclined canyon in remote and very rugged terrain. Initially, the piers of the bridge were built vertically. They were then rotated 30 deg so that they could provide beneficial arch and cantilever action and also to insure a safe foundation. Precast concrete segments form the soffit along the suspended cables. In turn, the soffit was used as a working platform on which precast bents and roadway beams were erected. This article describes the construction sequence of the bridge erection with the aid of diagrams and photographs.

First results from the north polar auroral radar

This paper reports a preliminary result from the operation of the polar auroral radar (a HF sweep frequency sounder with an antenna having a rotation period of 6 min) located at Resolute Bay. North West Territories, Canada. With the aid of all-sky photographs and statistical auroral data it is shown that such a radar can locate the instantaneous position of the auroral oval. (auth)

36—THE ASSESSMENT OF THE APPEARANCE RETENTION OF CARPETS

Experiments are reported in which changes in the appearance of carpet samples after treatment ranging from 2 × 104 to 20 × 104 revolutions in a Tetrapod Walker were assessed with the aid of photographs of the new and treated samples. It was found that photographs, taken under controlled conditions, can be used as a record and basis for the assessment of changes in appearance resulting mainly from changes in texture, without much disturbing effect from colour and pattern. The ranking of carpets, based on changes in their appearance, did not alter significantly after 5 × 104 revolutions in the Tetrapod Walker. Results from the Tetrapod Walker are compared with those from a floor trial, where the effects of soiling caused further interference with the assessment.

A Regional Study of Landsliding Near Ottawa

The stability of natural slopes near Ottawa has been examined from a regional approach. With the aid of aerial photographs, the density and distribution of past landslides have been ascertained, and the development of more recent slides has been traced. This information, combined with details of the present day topography, groundwater conditions, and soil characteristics, leads to a conclusion that factors influencing slope stability vary markedly throughout the region, and certain areas are much more prone to sliding than others.The strength of soils in the region is discussed, including the development of a logical shear strength relationship which incorporates the effects both of cementation strength and fissuring. The influence of sample size on the extrapolation of laboratory triaxial test results to the field situation is introduced. Details of the method of landslide analysis used are given.Considerable evidence is presented to support the presence of separate marine and freshwater clay layers in the Ottawa area, and to suggest that flow slides are confined to the upper freshwater deposit. These two clay soils are most graphically distinguished by differences in fissure spacing and pore water chemistry.

The influence of tectonics on the geotechnical properties of Calabrian rocks and the mapping of slope instability using aerial photographs

Summary The Calabrian peninsula is undergoing rapid degradation at the present time by erosion and landsliding. These phenomena are aggravated by the reduced strength of many of the rock formations forming the peninsula, resulting from Alpine tectonic movements. Maps showing landslides and related features were prepared, with the aid of aerial photographs, in conjunction with the geological re-mapping of the peninsula at a scale of 1 : 25 000.

The epitaxial growth of cadmium sulphide on gallium arsenide substrates

Single crystal layers of CdS have been grown on the three low index planes of GaAs. The growth rate decreased in the order (1 IIB), (110), (111 A), (100) substrate orientation and the orientations of CdS obtained were (0001) S-face, (10 1¯ 3), (0001) Cd-face and (30 3¯ 4), respectively. The CdS orientations obtained are correlated with the atomic arrangements on the substrate and deposit planes with the aid of Laue photographs.

SOME REMARKS ON AFRICAN DISTURBANCES AND THEIR PROGRESS OVER THE TROPICAL ATLANTIC

Abstract A daily analysis of the 2,000- and 10,000-ft streamlines over West Africa was made for a 3½-mo period beginning in July 1968. With the aid of satellite photographs and auxiliary sea-level pressure data, a total of 33 synoptic scale wave perturbations were observed to move across West Africa and the tropical Atlantic Ocean during this period. Some general features of these disturbances are summarized, including facts on their origin, speed, intensity, distribution of sea-level pressure, appearance on the satellite photographs, and movement over the Atlantic Ocean. The effects of the large-scale circulation and the influence of sea-surface temperatures on the movement and intensity of disturbances are also discussed.

A Simple Photographic Aid to the Illustration of Insects and other Small Organisms

A Simple Photographic Aid to the Illustration of Insects and other Small Organisms

A photographic aid to the measurement of objects in sections

A photographic aid to the measurement of objects in sections