4,734 research outputs found
Effects of temperature on the biology of the northern shrimp, Pandalus borealis, in the Gulf of Maine
Length-frequency data collected from inshore and offshore locations in the Gulf of Maine in 1966-1968 indicated that ovigerous female northern shrimp (Pandalus borealis) first appeared offshore in August and September and migrated
inshore in the fall and winter. Once eggs hatched, surviving females returned offshore. Juveniles and males migrated offshore during their first two years of life. Sex transition occurred in both inshore and oll'shore waters, but most males changed sex offshore during their third and fourth years. Most shrimp changed sex and matured as females for the first time in their fourth year. Smaller females and females exposed to colder bottom temperatures spawned first. The incidence of egg parasitism peaked in January and was higher for shrimp exposed to warmer bottom temperatures. Accelerated growth at higher temperatures appeared to result in earlier or more rapid sex transition. Males and non-ovigerous females were observed to make diurnal vertical migrations, but were not found in near-
surface waters where the temperature exceeded 6°C. Ovigerous females fed more heavily on benthic molluscs in inshore waters in the winter, presumably because the egg masses they were carrying prevented them from migrating vertically at night.
Northern shrimp were more abundant in the southwestern region of the Gulf of Maine where bottom temperatures remain low throughout the year. Bottom trawl catch rates were highest in Jeffreys Basin where bottom temperatures were lower than at any other sampling location. Catch rates throughout the study area were inversely related to bottom temperature and reached a maximum at 3°C.
An increase of 40% in fecundity between 1973 and 1979 was associated with a decline of 2-3°C in April-July offshore bottom temperatures. Furthermore, a decrease in mean fecundity per 25 mm female between 1965 and 1970 was linearly related to reduced landings between 1969 and 1974. It is hypothesized that temperature-induced changes in fecundity and, possibly, in the extent of egg mortality
due to parasitism, may provide a mechanism which could partially account for changes in the size of the Gulf of Maine northern shrimp population during the last thirty years. (PDF file contains 28 pages.
Investigation using data from ERTS-1 to develop and implement utilization of living marine resources
The author has identified the following significant results. This 15-month ERTS-1 investigation produced correlations between satellite, aircraft, menhaden fisheries, and environmental sea truth data from the Mississippi Sound. Selected oceanographic, meteorological, and biological parameters were used as indirect indicators of the menhaden resource. Synoptic and near real time sea truth, fishery, satellite imagery, aircraft acquired multispectral, photo and thermal IR information were acquired as data inputs. Computer programs were developed to manipulate these data according to user requirements. Preliminary results indicate a correlation between backscattered light with chlorophyll concentration and water transparency in turbid waters. Eight empirical menhaden distribution models were constructed from combinations of four fisheries-significant oceanographic parameters: water depth, transparency, color, and surface salinity. The models demonstrated their potential for management utilization in areas of resource assessment, prediction, and monitoring
Burgess v. State, 313 So. 2d 479 (Fla. 2d Dist. Ct. App. 1975), cert. denied, 326 So. 2d 441 (Fla. 1976)
Criminal Law- ARREST- COURT UPHOLDS THE RIGHT TO RESIST AN UNLAWFUL ARREST, BUT ISSUE SHOULD BE REVISITED UNDER NEW STATUTE
Wrestling with Destiny: The Cultural Socialization of Anger and Healing in African American Males
Society’s negative images of Black males have devastating consequences for their emotional and spiritual health. The PLAAY project (Preventing Long-term Anger and Aggression in Youth) is a multi-component program that seeks to reduce the anger and aggression of Black urban youth with a history of interpersonal conflict. The program components include in-vivo assessment and intervention during athletic movement (basketball play and escapist martial arts), cultural socialization therapy, and parent empowerment groups. In the martial arts and basketball intervention components, the role of movement is essential to understanding how the boys express their confidence and frustration. This article begins with a reflection on the author’s own emotional and cultural anger towards the limits of Western scholarship and collegiality, examines the theological implications of imaging on Black male mental health, and finally describes the development and procedures of PLAAY. Theological and psychological implications of culturally relevant interventions will be discussed
A Study of the Lalande, New Mexico, Yonо̄zu, Japan, and Glorieta Mountain, New Mexico Meteorites
This thesis presents details relating to the discovery of three meteorites, as well as information concerning their acquisition, description, and mineralogy. These three meteorites are the Lalande, New Mexico chondrite (E.C.N. = 1047,343), the Yonо̄zu, Japan chondrite (E.C.N. = 1394,380), and the Glorieta Mountain, New Mexico siderite (E.C.N. = 1058,356).
The Lalande, New Mexico meteorite is composed of olivine and enstatite (var. hypersthene), with small percentages of enstatite-clinoenstatite intergrowths, secondary hematite, and dispersed metallic grains. Alteration to iron oxide has produced a strong stain over most of the component grains. The meteorite is classified as a hypersthene-olivine chondrite (Chy).
The Yonо̄zu, Japan meteorite is composed of olivine and enstatite (var. hypersthene), with small percentages of enstatite-clinoenstatite intergrowths, secondary hematite, possible diopside and anorthite, and metallic grains. A very strong coating of iron oxide has been produced on many of the non-metallic grains by alteration of the olivine and hypersthene. The meteorite is classified as a hypersthene-olivine chondrite (Chy).
The Glorieta Mountain meteorite is a siderite composed of kamacite, taenite, and plessite, with a small percentage of schreibersite scattered throughout the kamacite. This specimen shows none of the pallasitic areas which have been reported in some other members of this fall. The meteorite is classified a medium octahedrite (Om)
Fixed-base simulation evaluation of various low-visibility landing systems for helicopters
Fixed base simulation evaluation of one fully automatic and six manual low visibility landing systems for helicopter
Aircraft control system
An aircraft control system is described which is particularly suited to rotary wing aircraft. Longitudinal acceleration and course rate commands are derived from a manual control stick to control translational velocity of the aircraft along a flight path. In the collective channel the manual controls provide vertical velocity commands. In the yaw channel the manual controls provide sideslip or heading rate commands at high or low airspeeds, respectively. The control system permits pilots to fly along prescribed flight paths in a precise manner with relatively low work load
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