Circular No. 6 - Measurement and Distribution of Irrigation Water

This circular has been prepared to meet the more urgent and immediate needs of the water user. The complications which usually arise in water measurement have been eliminated to such an extent that anyone who will follow the few simple instructions outlined in the following pages can learn to measure the flow of irrigation streams under ordinary conditions

Sublethal Behavioral and Physiological Effects of the Biomedical Bleeding Process on the American Horseshoe Crab, Limulus polyphemus

The hemolymph of the American horseshoe crab, Limulus polyphemus, is harvested from over 500,000 animals annually to produce Limulus amebocyte lysate (LAL), a medically important product used to detect pathogenic bacteria. Declining abundance of spawning Limulus females in heavily harvested regions suggests deleterious effects of this activity, and while mortality rates of the harvest process are known to be 10%–30%, sublethal behavioral and physiological effects are not known. In this study, we determined the impact of the harvest process on locomotion and hemocyanin levels of 28 female horseshoe crabs. While mortality rates after bleeding (18%) were similar to previous studies, we found significant decreases in the linear and angular velocity of freely moving animals, as well as changes in their activity levels and expression of circatidal behavioral rhythms. Further, we found reductions in hemocyanin levels, which may alter immune function and cuticle integrity. These previously unrecognized behavioral and physiological deficits suggest that the harvest of LAL may decrease female fitness, and thus may contribute to the current population decline

A Noninvasive Method For In situ Determination of Mating Success in Female American Lobsters (Homarus americanus)

Despite being one of the most productive fisheries in the Northwest Atlantic, much remains unknown about the natural reproductive dynamics of American lobsters. Recent work in exploited crustacean populations (crabs and lobsters) suggests that there are circumstances where mature females are unable to achieve their full reproductive potential due to sperm limitation. To examine this possibility in different regions of the American lobster fishery, a reliable and noninvasive method was developed for sampling large numbers of female lobsters at sea. This method involves inserting a blunt-tipped needle into the female\u27s seminal receptacle to determine the presence or absence of a sperm plug and to withdraw a sample that can be examined for the presence of sperm. A series of control studies were conducted at the dock and in the laboratory to test the reliability of this technique. These efforts entailed sampling 294 female lobsters to confirm that the presence of a sperm plug was a reliable indicator of sperm within the receptacle and thus, mating. This paper details the methodology and the results obtained from a subset of the total females sampled. Of the 230 female lobsters sampled from George\u27s Bank and Cape Ann, MA (size range = 71-145 mm in carapace length), 90.3% were positive for sperm. Potential explanations for the absence of sperm in some females include: immaturity (lack of physiological maturity), breakdown of the sperm plug after being used to fertilize a clutch of eggs, and lack of mating activity. The surveys indicate that this technique for examining the mating success of female lobsters is a reliable proxy that can be used in the field to document reproductive activity in natural populations

A Noninvasive Method For In situ Determination of Mating Success in Female American Lobsters (Homarus americanus)

Despite being one of the most productive fisheries in the Northwest Atlantic, much remains unknown about the natural reproductive dynamics of American lobsters. Recent work in exploited crustacean populations (crabs and lobsters) suggests that there are circumstances where mature females are unable to achieve their full reproductive potential due to sperm limitation. To examine this possibility in different regions of the American lobster fishery, a reliable and noninvasive method was developed for sampling large numbers of female lobsters at sea. This method involves inserting a blunt-tipped needle into the female\u27s seminal receptacle to determine the presence or absence of a sperm plug and to withdraw a sample that can be examined for the presence of sperm. A series of control studies were conducted at the dock and in the laboratory to test the reliability of this technique. These efforts entailed sampling 294 female lobsters to confirm that the presence of a sperm plug was a reliable indicator of sperm within the receptacle and thus, mating. This paper details the methodology and the results obtained from a subset of the total females sampled. Of the 230 female lobsters sampled from George\u27s Bank and Cape Ann, MA (size range = 71-145 mm in carapace length), 90.3% were positive for sperm. Potential explanations for the absence of sperm in some females include: immaturity (lack of physiological maturity), breakdown of the sperm plug after being used to fertilize a clutch of eggs, and lack of mating activity. The surveys indicate that this technique for examining the mating success of female lobsters is a reliable proxy that can be used in the field to document reproductive activity in natural populations

A noninvasive method for in situ determination of mating success in female American lobsters (Homarus americanus)

Despite being one of the most productive fisheries in the Northwest Atlantic, much remains unknown about the natural reproductive dynamics of American lobsters. Recent work in exploited crustacean populations (crabs and lobsters) suggests that there are circumstances where mature females are unable to achieve their full reproductive potential due to sperm limitation. To examine this possibility in different regions of the American lobster fishery, a reliable and noninvasive method was developed for sampling large numbers of female lobsters at sea. This method involves inserting a blunt-tipped needle into the female's seminal receptacle to determine the presence or absence of a sperm plug and to withdraw a sample that can be examined for the presence of sperm. A series of control studies were conducted at the dock and in the laboratory to test the reliability of this technique. These efforts entailed sampling 294 female lobsters to confirm that the presence of a sperm plug was a reliable indicator of sperm within the receptacle and thus, mating. This paper details the methodology and the results obtained from a subset of the total females sampled. Of the 230 female lobsters sampled from George's Bank and Cape Ann, MA (size range = 71-145 mm in carapace length), 90.3% were positive for sperm. Potential explanations for the absence of sperm in some females include: immaturity (lack of physiological maturity), breakdown of the sperm plug after being used to fertilize a clutch of eggs, and lack of mating activity. The surveys indicate that this technique for examining the mating success of female lobsters is a reliable proxy that can be used in the field to document reproductive activity in natural populations

Cultural Shift from Interdependence to Independence

Asian Indian Immigrant Parents (AIIP) of adolescents are encountering high levels of acculturation and enculturation experiences that are adding complexity to their parenting styles while raising teenagers. Having a different background embedded within collectivistic cultures versus the enculturating experiences of their teenagers being raised in the United States with individualistic cultures is forming a barrier. The purpose of this research was to explore those challenges with cultural barriers of AIIP who struggle to raise their adolescents in the United States. This qualitative research utilized a phenomenological design to explore the in-depth lived experiences of five AIIP from a large Mid-southern city in the US who are navigating acculturation, enculturation, and parenting with their adolescent children. The AIIP participated in 60-90 minutes, semi-structured interviews virtually, using Zoom due to the global pandemic. The interview transcripts were thematically analyzed through phenomenology using four levels of analysis and interrater reliability with two raters which provided a process that allowed for identifying complexities in their experiences. The preliminary finding shows that the AIIP struggled with anxiety, frustration, and fear during their navigation of parenting in an entirely different culture from the culture they were raised in. Keywords: Asian-Indian-Immigrant-Parents; Acculturation; Enculturation; Parenting-Challenges; Phenomenological-Inquiry.Los Padres Inmigrantes Indios Asiáticos (AIIP, por sus siglas en inglés) de adolescentes se encuentran con altos niveles de aculturación y experiencias de enculturación que agregan complejidad a sus estilos de crianza mientras crían a los adolescentes. Tener un trasfondo diferente incrustado en culturas colectivistas versus las experiencias de enculturación de sus adolescentes criados en los Estados Unidos con culturas individualistas está formando una barrera. El propósito de esta investigación fue explorar esos desafíos con barreras culturales de los AIIP que luchan por criar a sus adolescentes en los Estados Unidos. Esta investigación cualitativa utilizó un diseño fenomenológico para explorar las experiencias vividas en profundidad de cinco AIIP de una gran ciudad del medio sur de los Estados Unidos que están navegando por la aculturación, la enculturación y la crianza de sus hijos adolescentes. Los AIIP participaron en entrevistas semiestructuradas de 60-90 minutos de forma virtual, utilizando Zoom debido a la pandemia mundial. Las transcripciones de las entrevistas se analizaron temáticamente a través de la fenomenología utilizando cuatro niveles de análisis y confiabilidad entre evaluadores con dos evaluadores que proporcionaron un proceso que permitió identificar complejidades en sus experiencias. El hallazgo preliminar muestra que los AIIP lucharon contra la ansiedad, la frustración y el miedo durante su crianza en una cultura completamente diferente de la cultura en la que se criaron. Palabras clave: Padres-inmigrantes-indios-asiáticos; aculturación; enculturación; Retos de la crianza de los hijos; Fenomenológico-Indagación

Investigation of a pulsed electrothermal thruster system

The performance of an ablative wall Pulsed Electrothermal (PET) thruster is accurately characterized on a calibrated thrust stand, using polyethylene propellant. The thruster is tested for four configurations of capillary length and pulse length. The exhaust velocity is determined with twin time-of-flight photodiode stagnation probes, and the ablated mass is measured from the loss over ten shots. Based on the measured thrust impulse and the ablated mass, the specific impulse varies from 1000 to 1750 seconds. The thrust to power varies from .05 N/kW (quasi-steady mode) to .10 N/kW (unsteady mode). The thruster efficiency varies from .56 at 1000 seconds to .42 at 1750 seconds. A conceptual design is presented for a 40 kW PET propulsion system. The point design system performance is .62 system efficiency at 1000 seconds specific impulse. The system's reliability is enhanced by incorporating 20, 20 kW thruster modules which are fired in pairs. The thruster design is non-ablative, and uses water propellant, from a central storage tank, injected through the cathode

A statistical study of variation in the catch of plankton nets

Staternent of the Problern.----In a previous communication, Winsor and Walford (1936) analyzed the results of repeated vertical hauls of different types of plankton nets, making use of data available in the literature. They concluded that the observed results could be accounted for reasonably well on the assumptions that (a) the organisms were randomly distributed in the medium and (b) that the volume of medium effectively sampled varied from haul to haul. From this result it follows that as the total catch is increased (as by increasing the net size) the reliability of a population estimate is ultimately limited by variation in volume sampled; and that where such conditions hold, it is useless to attempt greater accuracy by increasing either the total catch or the fraction counted much beyond the point where 100 organisms of the kind in question are counted

National Preferences in Business and Communication Education: A Survey Update

This article discusses the results of a survey in the U.S. regarding national preferences in business and communication education. From the results of this and the previous study, it appears that the skills most valued in the contemporary job-entry market are communication skills. The skills of listening, oral communication (both interpersonal and public), written communication and the trait of enthusiasm are indicated to be the most important. Again, it would appear to follow that university officials wishing to be of the greatest help to their graduates in finding employment would make sure that basic competencies in oral and written communication are developed. Courses in listening, interpersonal, and public communication would form the basis of meeting the oral communication competencies. One way to meet the written communication expectation would be to include courses in rhetorical and business writing. Further, training in interviewing skills would be in order to help university graduates maximize their appearance and personality projection as well as gather information necessary for appropriate decision making