834 research outputs found
Circular 12
Ih Alaska—
Oats-and-peas make better silage than hay /
Silage and silos pay /
Field-choppers cut labor costs /
Smooth bromegrass is an excellent forage /
Alsike clover and Hubam sweetclover /
make good annuals /
Better forage means bigger profitsIn cooperation with the United States Department of Agriculture, Agricultural Research Administratio
Circular 20
Since fanning in Alaska first began and especially
since dairy farming became the primary agricultural
industry, there has existed a need for
hardy legumes which would survive Alaska winters
and produce satisfactory yields of high quality
forage. To meet this need hundreds of legume
species and strains have been introduced during
the past 40 or more years. Almost all have lacked
the necessary hardiness or have not been satisfactory
agronomically. The release of Alaskland
red clover in the spring of 1953 is the first time
a hardy legume has been made available to
growers in Alaska.Cooperating with the United States Department of Agriculture, Agricultural Research Administratio
Using Participatory Housing Construction Methods to Develop Small Sites in Public Ownership
The research into self-build housing in this thesis was undertaken in the context of a perceived housing crisis in Britain. The shortage of decent, affordable new dwellings is widespread but particularly extreme in inner London. Hoxton, a diverse neighbourhood in the London Borough of Hackney, was thus selected as a suitable location for the examination of its urban topography and to develop designs for self-build housing. This was in part due to the author being a resident and former member of the local council, and also because of the completion in 2012 of my own self-built house/office in the locality. Four headings – Land, Delivery, Finance and Design – were used to govern the initial design approach and to provide the structure for the thesis. The initial hypothesis was that there were numerous small under-used sites within the study area which could be developed by self-builders. These sites in Hoxton were initially identified through a series of walking tours, recording potential sites in photographs. The sites were subsequently tested to explore their potential for housing designs by using simple, volumetric, three-dimensional digital models. Results confirmed the initial hypothesis, with space for around 280 potential dwellings being identified across almost 50 sites, most owned by the local council. Some sites were vacant while others held infrequently occupied garages, community halls and such like. There is an imperative in any potential construction project to involve local residents, and so – after studying useful British case-studies – a series of public engagement exercises and local exhibitions were undertaken to find potential self-builders and understand potential objections. Ultimately a number of the sites were explored to propose detailed architectural designs, leading to various planning applications, and engaging the Mayor of Hackney and local councillors in the goal of creating a local pilot project for self-build housing
Naturalism in the latter half of the nineteenth century
Thesis (Ph.D.)--Boston Universit
Poincare duality and Periodicity
We construct periodic families of Poincare complexes, partially solving a
question of Hodgson that was posed in the proceedings of the 1982 Northwestern
homotopy theory conference. We also construct infinite families of Poincare
complexes whose top cell falls off after one suspension but which fail to embed
in a sphere of codimension one. We give a homotopy theoretic description of the
four-fold periodicity in knot cobordism.Comment: A significant revision. In this version we produce infinite families
of examples of Poincare complexes whose top cell falls off after one
suspension, but which do not embed in codimension one. We also rewrote the
knot periodicity section in terms of Seifert surfaces rather than knot
complement
Quadrilateral-octagon coordinates for almost normal surfaces
Normal and almost normal surfaces are essential tools for algorithmic
3-manifold topology, but to use them requires exponentially slow enumeration
algorithms in a high-dimensional vector space. The quadrilateral coordinates of
Tollefson alleviate this problem considerably for normal surfaces, by reducing
the dimension of this vector space from 7n to 3n (where n is the complexity of
the underlying triangulation). Here we develop an analogous theory for
octagonal almost normal surfaces, using quadrilateral and octagon coordinates
to reduce this dimension from 10n to 6n. As an application, we show that
quadrilateral-octagon coordinates can be used exclusively in the streamlined
3-sphere recognition algorithm of Jaco, Rubinstein and Thompson, reducing
experimental running times by factors of thousands. We also introduce joint
coordinates, a system with only 3n dimensions for octagonal almost normal
surfaces that has appealing geometric properties.Comment: 34 pages, 20 figures; v2: Simplified the proof of Theorem 4.5 using
cohomology, plus other minor changes; v3: Minor housekeepin
Effects of temperature and salinity on the standard metabolic rate (SMR) of the caridean shrimp Palaemon peringueyi
The standard metabolic rate (SMR) of the caridean shrimp Palaemon peringueyi to changes in temperature (15–30 °C), salinity (0–45‰) and a combination thereof was investigated. The rate of oxygen consumption of the shrimp was determined using a YSI oxygen meter. At a constant salinity of 35‰ the respiration rate of P. peringueyi increased with an increase in temperature and ranged between 0.260 and 0.982 μl O[subscript 2] mg wwt[superscript −1] h[superscript −1]. The Q[subscript 10] value over the temperature range 15–25 °C was estimated at 3.13. At a constant temperature of 15 °C the respiration rate of P. peringueyi also increased with an increase in salinity and ranged between 0.231 and 0.860 μl O[subscript 2] mg wwt[superscript −1] h[superscript −1]. For combination experiments the absence of any significant difference in the respiration rate of P. peringueyi at the four temperatures over the salinity range 15–35‰ suggests that the shrimp is well adapted to inhabiting environments characterised by variations in salinity and temperature such as those encountered within the middle and lower reaches of permanently open estuaries with substantial freshwater inflow. On the other hand, the total mortality of the shrimp recorded at salinities 35‰ suggests that the shrimp may experience osmotic stress in freshwater deprived permanently open and intermittently open estuaries where hypersaline conditions may develop
A Multi-Purpose Modular Electronics Integration Node for Exploration Extravehicular Activity
As NASA works to develop an effective integrated portable life support system design for exploration Extravehicular activity (EVA), alternatives to the current system s electrical power and control architecture are needed to support new requirements for flexibility, maintainability, reliability, and reduced mass and volume. Experience with the current Extravehicular Mobility Unit (EMU) has demonstrated that the current architecture, based in a central power supply, monitoring and control unit, with dedicated analog wiring harness connections to active components in the system has a significant impact on system packaging and seriously constrains design flexibility in adapting to component obsolescence and changing system needs over time. An alternative architecture based in the use of a digital data bus offers possible wiring harness and system power savings, but risks significant penalties in component complexity and cost. A hybrid architecture that relies on a set of electronic and power interface nodes serving functional models within the Portable Life Support System (PLSS) is proposed to minimize both packaging and component level penalties. A common interface node hardware design can further reduce penalties by reducing the nonrecurring development costs, making miniaturization more practical, maximizing opportunities for maturation and reliability growth, providing enhanced fault tolerance, and providing stable design interfaces for system components and a central control. Adaptation to varying specific module requirements can be achieved with modest changes in firmware code within the module. A preliminary design effort has developed a common set of hardware interface requirements and functional capabilities for such a node based on anticipated modules comprising an exploration PLSS, and a prototype node has been designed assembled, programmed, and tested. One instance of such a node has been adapted to support testing the swingbed carbon dioxide and humidity control element in NASA s advanced PLSS 2.0 test article. This paper will describe the common interface node design concept, results of the prototype development and test effort, and plans for use in NASA PLSS 2.0 integrated tests
Advanced Prototype Fan Operating Experience, Post Test Evaluation, and Refurbishment for PLSS 2.0 Test Use
NASA s plans for Extravehicular Activity (EVA) portable life support systems for future exploration missions result in different design requirements than those which led to the combined fan / pump / separator in the current ISS Extravehicular Mobility Unit (EMU). To meet these new requirements, NASA contracted with Hamilton Sundstrand to provide two new prototype fans designed to meet anticipated future system requirements. Based on design trade studies, a high speed fan with mechanical bearing support of the rotating elements and a novel non-metallic barrier canned motor design was developed and implemented in the deliverable prototypes. The prototypes, which used two different bearing lubricants, have been extensively tested in both stand-alone and integrated system tests in NASA laboratories and proven to meet the anticipated performance requirements. Subsequently, they have been subjected to post test inspection and analysis in Hamilton Sundstrand laboratories to assess the effects of integrated operation and resultant exposure to vent loop contaminants. Results have confirmed expectations that one of the lubricants would be superior in this application and the prototype fans have been reassembled with new bearings with the superior lubricant. They have now been returned to the Johnson Space Center for further testing and maturation as part of NASA s PLSS 2.0 integrated test effort. This paper will discuss the test history of these units, resulting test data, the results of post test evaluation, and plans for further testing in the near future
Concerns of Female Adolescents About Menarche and First Sexual Intercourse: Mixed Methods Analysis of Social Media Questions
Background: Adolescents use social media for information on medical and social aspects of maturation.
Objective: The aim of this study was to investigate the concerns and information needs of adolescents regarding menarche and first sexual intercourse.
Methods: Questions about menarche or first sexual intercourse were obtained from Yahoo Answers, a community-based social media question-and-answer website. A total of 1226 questions were analyzed. We focused on 123 question pairs made by users who asked questions on both topics and reported their ages at each. Quantitative and qualitative analyses were performed on these question pairs.
Results: Qualitative analysis identified uncertainty as a significant theme for both menarche and first intercourse. Quantitative analysis showed that uncertainty was expressed in 26% (13/50) of menarche questions and 14% (7/50) of intercourse questions. Lack of communication was expressed in 4% (2/50) of menarche questions, compared with 8% (4/50) of intercourse questions. Ages at menarche and at first sexual intercourse were correlated, with women reporting menarche at the age of 13 years or younger being 2.6 times more likely to experience first sexual intercourse before the age of 16 years (PP=.002).
Conclusions: The questions of adolescents on the topics of menarche and first sexual intercourse express anxiety and uncertainty and are associated with a lack of information and deficient communication with parents. The more normative and expected a behavior, the less these factors appear. Therefore, parents and educators should, to the extent possible, improve communication around these topics, especially when they occur at less typical ages
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