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Sample records for evolutionof fundamental reproductive

  1. Fundamental roles of reactive oxygen species and protective mechanisms in the female reproductive system

    PubMed Central

    Fujii, Junichi; Iuchi, Yoshihito; Okada, Futoshi

    2005-01-01

    Controlled oxidation, such as disulfide bond formation in sperm nuclei and during ovulation, plays a fundamental role in mammalian reproduction. Excess oxidation, however, causes oxidative stress, resulting in the dysfunction of the reproductive process. Antioxidation reactions that reduce the levels of reactive oxygen species are of prime importance in reproductive systems in maintaining the quality of gametes and support reproduction. While anti-oxidative enzymes, such as superoxide dismutase and peroxidase, play a central role in eliminating oxidative stress, reduction-oxidation (redox) systems, comprised of mainly glutathione and thioredoxin, function to reduce the levels of oxidized molecules. Aldo-keto reductase, using NADPH as an electron donor, detoxifies carbonyl compounds resulting from the oxidation of lipids and proteins. Thus, many antioxidative and redox enzyme genes are expressed and aggressively protect gametes and embryos in reproductive systems. PMID:16137335

  2. Application of genomic and molecular methods to fundamental questions in canine and feline reproductive health.

    PubMed

    Meyers-Wallen, V N

    2012-12-01

    Molecular tools are becoming increasingly available to investigate the genetic basis of reproductive disorders in dogs and cats. These were first successful in identifying the molecular basis of diseases inherited as simple Mendelian traits, and these are now being applied to those that are inherited as complex traits. In order to promote similar studies of reproductive disorders, we need to understand how we can play a proactive role in accumulating sufficient case material. We also need to understand these mutation discovery tools and identify collaborators who have experience with their use. The candidate gene and genomic approaches to mutation discovery in dogs are presented, including new sequencing methods and those used to confirm that a mutation has a role in disease pathology. As the final goal is to use our study results to prevent inherited disorders, we need to consider how we can promote efficiency in obtaining DNA test results and providing genetic counselling.

  3. Survival, Growth and Reproduction of Non-Native Nile Tilapia II: Fundamental Niche Projections and Invasion Potential in the Northern Gulf of Mexico

    PubMed Central

    Lowe, Michael R.; Wu, Wei; Peterson, Mark S.; Brown-Peterson, Nancy J.; Slack, William T.; Schofield, Pamela J.

    2012-01-01

    Understanding the fundamental niche of invasive species facilitates our ability to predict both dispersal patterns and invasion success and therefore provides the basis for better-informed conservation and management policies. Here we focus on Nile tilapia (Oreochromis niloticus Linnaeus, 1758), one of the most widely cultured fish worldwide and a species that has escaped local aquaculture facilities to become established in a coastal-draining river in Mississippi (northern Gulf of Mexico). Using empirical physiological data, logistic regression models were developed to predict the probabilities of Nile tilapia survival, growth, and reproduction at different combinations of temperature (14 and 30°C) and salinity (0–60, by increments of 10). These predictive models were combined with kriged seasonal salinity data derived from multiple long-term data sets to project the species' fundamental niche in Mississippi coastal waters during normal salinity years (averaged across all years) and salinity patterns in extremely wet and dry years (which might emerge more frequently under scenarios of climate change). The derived fundamental niche projections showed that during the summer, Nile tilapia is capable of surviving throughout Mississippi's coastal waters but growth and reproduction were limited to river mouths (or upriver). Overwinter survival was also limited to river mouths. The areas where Nile tilapia could survive, grow, and reproduce increased during extremely wet years (2–368%) and decreased during extremely dry years (86–92%) in the summer with a similar pattern holding for overwinter survival. These results indicate that Nile tilapia is capable of 1) using saline waters to gain access to other watersheds throughout the region and 2) establishing populations in nearshore, low-salinity waters, particularly in the western portion of coastal Mississippi. PMID:22848533

  4. Survival, growth and reproduction of non-native Nile tilapia II: fundamental niche projections and invasion potential in the northern Gulf of Mexico

    USGS Publications Warehouse

    Lowe, Michael R.; Wu, Wei; Peterson, Mark S.; Brown-Peterson, Nancy J.; Slack, William T.; Schofield, Pamela J.

    2012-01-01

    Understanding the fundamental niche of invasive species facilitates our ability to predict both dispersal patterns and invasion success and therefore provides the basis for better-informed conservation and management policies. Here we focus on Nile tilapia (Oreochromis niloticus Linnaeus, 1758), one of the most widely cultured fish worldwide and a species that has escaped local aquaculture facilities to become established in a coastal-draining river in Mississippi (northern Gulf of Mexico). Using empirical physiological data, logistic regression models were developed to predict the probabilities of Nile tilapia survival, growth, and reproduction at different combinations of temperature (14 and 30°C) and salinity (0–60, by increments of 10). These predictive models were combined with kriged seasonal salinity data derived from multiple long-term data sets to project the species' fundamental niche in Mississippi coastal waters during normal salinity years (averaged across all years) and salinity patterns in extremely wet and dry years (which might emerge more frequently under scenarios of climate change). The derived fundamental niche projections showed that during the summer, Nile tilapia is capable of surviving throughout Mississippi's coastal waters but growth and reproduction were limited to river mouths (or upriver). Overwinter survival was also limited to river mouths. The areas where Nile tilapia could survive, grow, and reproduce increased during extremely wet years (2–368%) and decreased during extremely dry years (86–92%) in the summer with a similar pattern holding for overwinter survival. These results indicate that Nile tilapia is capable of 1) using saline waters to gain access to other watersheds throughout the region and 2) establishing populations in nearshore, low-salinity waters, particularly in the western portion of coastal Mississippi.

  5. Reproduction, physiology and biochemistry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter summarizes fundamental knowledge and recent discoveries about the reproduction, physiology and biochemistry of plant-parasitic nematodes. Various types of reproduction are reviewed, including sexual reproduction and mitotic and meiotic parthenogenesis. Although much is known about the p...

  6. Fundamental ecology is fundamental.

    PubMed

    Courchamp, Franck; Dunne, Jennifer A; Le Maho, Yvon; May, Robert M; Thébaud, Christophe; Hochberg, Michael E

    2015-01-01

    The primary reasons for conducting fundamental research are satisfying curiosity, acquiring knowledge, and achieving understanding. Here we develop why we believe it is essential to promote basic ecological research, despite increased impetus for ecologists to conduct and present their research in the light of potential applications. This includes the understanding of our environment, for intellectual, economical, social, and political reasons, and as a major source of innovation. We contend that we should focus less on short-term, objective-driven research and more on creativity and exploratory analyses, quantitatively estimate the benefits of fundamental research for society, and better explain the nature and importance of fundamental ecology to students, politicians, decision makers, and the general public. Our perspective and underlying arguments should also apply to evolutionary biology and to many of the other biological and physical sciences.

  7. Fundamentally updating fundamentals.

    PubMed

    Armstrong, Gail; Barton, Amy

    2013-01-01

    Recent educational research indicates that the six competencies of the Quality and Safety Education for Nurses initiative are best introduced in early prelicensure clinical courses. Content specific to quality and safety has traditionally been covered in senior level courses. This article illustrates an effective approach to using quality and safety as an organizing framework for any prelicensure fundamentals of nursing course. Providing prelicensure students a strong foundation in quality and safety in an introductory clinical course facilitates early adoption of quality and safety competencies as core practice values.

  8. Reproduction in the water buffalo.

    PubMed

    Presicce, G A

    2007-09-01

    In this paper, an account of various aspects related to buffalo reproduction are given. Fundamental concepts of the reproductive physiology as well as manipulation of the reproductive function will be presented. This will include an overview of the most recent developments of the oestrous cycle and the ovulation control, new strategies of reproductive management for the improvement of genetic gain and the application of newly developed reproductive technologies, such as in vitro embryo production, embryo and sperm sexing and cloning.

  9. Tether fundamentals

    NASA Technical Reports Server (NTRS)

    Carroll, J. A.

    1986-01-01

    Some fundamental aspects of tethers are presented and briefly discussed. The effects of gravity gradients, dumbbell libration in circular orbits, tether control strategies and impact hazards for tethers are among those fundamentals. Also considered are aerodynamic drag, constraints in momentum transfer applications and constraints with permanently deployed tethers. The theoretical feasibility of these concepts are reviewed.

  10. Marketing fundamentals.

    PubMed

    Redmond, W H

    2001-01-01

    This chapter outlines current marketing practice from a managerial perspective. The role of marketing within an organization is discussed in relation to efficiency and adaptation to changing environments. Fundamental terms and concepts are presented in an applied context. The implementation of marketing plans is organized around the four P's of marketing: product (or service), promotion (including advertising), place of delivery, and pricing. These are the tools with which marketers seek to better serve their clients and form the basis for competing with other organizations. Basic concepts of strategic relationship management are outlined. Lastly, alternate viewpoints on the role of advertising in healthcare markets are examined. PMID:11401791

  11. Healthcare fundamentals.

    PubMed

    Kauk, Justin; Hill, Austin D; Althausen, Peter L

    2014-07-01

    In order for a trauma surgeon to have an intelligent discussion with hospital administrators, healthcare plans, policymakers, or any other physicians, a basic understanding of the fundamentals of healthcare is paramount. It is truly shocking how many surgeons are unable to describe the difference between Medicare and Medicaid or describe how hospitals and physicians get paid. These topics may seem burdensome but they are vital to all business decision making in the healthcare field. The following chapter provides further insight about what we call "the basics" of providing medical care today. Most of the topics presented can be applied to all specialties of medicine. It is broken down into 5 sections. The first section is a brief overview of government programs, their influence on care delivery and reimbursement, and past and future legislation. Section 2 focuses on the compliance, care provision, and privacy statutes that regulate physicians who care for Medicare/Medicaid patient populations. With a better understanding of these obligations, section 3 discusses avenues by which physicians can stay informed of current and pending health policy and provides ways that they can become involved in shaping future legislation. The fourth section changes gears slightly by explaining how the concepts of trade restraint, libel, antitrust legislation, and indemnity relate to physician practice. The fifth, and final, section ties all of components together by describing how physician-hospital alignment can be mutually beneficial in providing patient care under current healthcare policy legislation.

  12. Reproductive Hazards

    MedlinePlus

    ... and female reproductive systems play a role in pregnancy. Problems with these systems can affect fertility and ... a reproductive hazard can cause different effects during pregnancy, depending on when she is exposed. During the ...

  13. Reproduction and advances in reproductive studies in carnivores.

    PubMed

    Jewgenow, Katarina; Songsasen, Nucharin

    2014-01-01

    Reproductive mechanisms are extraordinarily diverse among species, even within the same phylogenetic clade. Due to this, it has been difficult to directly apply reproductive technologies developed in human and livestock to genetically manage ex situ wildlife, including carnivores. To date, more common, closely related species, e.g., domestic cats, dogs and ferrets have served as valuable models for developing reproductive technologies for managing rare, endangered carnivores. Artificial insemination and sperm cryopreservation have already been successfully used to manage ex situ populations in some carnivore species, such as the black-footed ferret, cheetah and giant panda. However, technologies aiming at preserving genetics of valuable females have not been fully developed in carnivores, due to the lack of fundamental knowledge about reproductive anatomy and physiology, gamete development, embryogenesis and cryopreservation. The present chapter is divided into two parts. The first part focuses on current knowledge about carnivore reproduction, with emphasis on species diversity in reproductive mechanisms. The second part highlights the progress in reproductive science and related technologies made during the last decade. In addition, we provide examples of how reproductive technologies can contribute to carnivore management and conservation. Although carnivores are comprised of 19 families, we will only focus our attention on four taxonomic groups, including felids, canids, ursids and mustelids. PMID:25091912

  14. Reproduction and advances in reproductive studies in carnivores.

    PubMed

    Jewgenow, Katarina; Songsasen, Nucharin

    2014-01-01

    Reproductive mechanisms are extraordinarily diverse among species, even within the same phylogenetic clade. Due to this, it has been difficult to directly apply reproductive technologies developed in human and livestock to genetically manage ex situ wildlife, including carnivores. To date, more common, closely related species, e.g., domestic cats, dogs and ferrets have served as valuable models for developing reproductive technologies for managing rare, endangered carnivores. Artificial insemination and sperm cryopreservation have already been successfully used to manage ex situ populations in some carnivore species, such as the black-footed ferret, cheetah and giant panda. However, technologies aiming at preserving genetics of valuable females have not been fully developed in carnivores, due to the lack of fundamental knowledge about reproductive anatomy and physiology, gamete development, embryogenesis and cryopreservation. The present chapter is divided into two parts. The first part focuses on current knowledge about carnivore reproduction, with emphasis on species diversity in reproductive mechanisms. The second part highlights the progress in reproductive science and related technologies made during the last decade. In addition, we provide examples of how reproductive technologies can contribute to carnivore management and conservation. Although carnivores are comprised of 19 families, we will only focus our attention on four taxonomic groups, including felids, canids, ursids and mustelids.

  15. Reproductive health.

    PubMed

    1999-04-01

    This article explores the reproductive health status of China. Since 1990, China has stepped up its efforts in promoting reproductive health and maternal and child health. Several studies demonstrated a remarkable progress made in this area. By 1997, maternal and infant mortality rates have declined, while the penetration rate for the immunization program and inpatient delivery rate increased. Despite these achievements, however, much remains to be done such as the lack of client-centered approaches to meet the increasingly diverse needs of the population for family planning services. A survey conducted in 1995 showed that the country's family planning program was focused primarily on demographic issues while little attention was given to reproductive health objectives. The situation improved when the State Planning Commission implemented its pilot program called the Quality of Care in Family Planning in China. The program yielded encouraging results including a reoriented philosophy towards reproductive health services, enhanced service facilities, informed choices for family planning methods, and the development of an operational information system. Another strategy adopted to address fertility and reproductive health issues was the implementation of adolescent reproductive health education as a required course for senior middle schools. Lastly, this article provided a brief overview of China's HIV/AIDS situation.

  16. Combustion Fundamentals Research

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Increased emphasis is placed on fundamental and generic research at Lewis Research Center with less systems development efforts. This is especially true in combustion research, where the study of combustion fundamentals has grown significantly in order to better address the perceived long term technical needs of the aerospace industry. The main thrusts for this combustion fundamentals program area are as follows: analytical models of combustion processes, model verification experiments, fundamental combustion experiments, and advanced numeric techniques.

  17. Exchange Rates and Fundamentals.

    ERIC Educational Resources Information Center

    Engel, Charles; West, Kenneth D.

    2005-01-01

    We show analytically that in a rational expectations present-value model, an asset price manifests near-random walk behavior if fundamentals are I (1) and the factor for discounting future fundamentals is near one. We argue that this result helps explain the well-known puzzle that fundamental variables such as relative money supplies, outputs,…

  18. AIDS and the future of reproductive freedom.

    PubMed

    Bayer, Ronald

    1990-01-01

    The specter of pediatric AIDS fundamentally challenges elements of the liberal ideological basis of women's reproductive freedom. Many public health officials hold that preventing transmission of HIV from mother to fetus requires efforts to discourage pregnancy by infected women. For over two decades, however, genetic counselors, feminists, and medical ethicists have stressed the importance of nondirective counseling in the context of reproductive choice. The question now confronted by American society is whether it will be possible to frame an ideology of reproductive choice that recognizes the limits of liberal individualism, while preserving the basic features of reproductive freedom.

  19. Reproductive physiology

    USGS Publications Warehouse

    Gee, G.F.; Russman, S.E.; Ellis, David H.; Gee, George F.; Mirande, Claire M.

    1996-01-01

    Conclusions: Although the general pattern of avian physiology applies to cranes, we have identified many physiological mechanisms (e.g., effects of disturbance) that need further study. Studies with cranes are expensive compared to those done with domestic fowl because of the crane's larger size, low reproductive rate, and delayed sexual maturity. To summarize, the crane reproductive system is composed of physiological and anatomical elements whose function is controlled by an integrated neural-endocrine system. Males generally produce semen at a younger age than when females lay eggs. Eggs are laid in clutches of two (1 to 3), and females will lay additional clutches if the preceding clutches are removed. Both sexes build nests and incubate the eggs. Molt begins during incubation and body molt may be completed annually in breeding pairs. However, remiges are replaced sequentially over 2 to 3 years, or abruptly every 2 to 3 years in other species. Most immature birds replace their juvenal remiges over a 2 to 3 year period. Stress interferes with reproduction in cranes by reducing egg production or terminating the reproductive effort. In other birds, stress elevates corticosterone levels and decreases LHRH release. We know little about the physiological response of cranes to stress.

  20. Reproductive hacking

    PubMed Central

    Dustin Rubinstein, C; Wolfner, Mariana F

    2014-01-01

    Seminal proteins are critical for reproductive success in all animals that have been studied. Although seminal proteins have been identified in many taxa, and female reproductive responses to receipt of these proteins have been documented in several, little is understood about the mechanisms by which seminal proteins affect female reproductive physiology. To explore this topic, we investigated how a Drosophila seminal protein, ovulin, increases ovulation rate in mated females. Ovulation is a relatively simple physiological process, with known female regulators: previous studies have shown that ovulation rate is promoted by the neuromodulator octopamine (OA) in D. melanogaster and other insects. We found that ovulin stimulates ovulation by increasing OA signaling in the female. This finding supports a model in which a male seminal protein acts through “hacking” a well-conserved, regulatory system females use to adjust reproductive output, rather than acting downstream of female mechanisms of control or in parallel pathways altogether. We also discuss similarities between 2 forms of intersexual control of behavior through chemical communication: seminal proteins and pheromones. PMID:25483253

  1. Female Reproductive System

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? Female Reproductive System KidsHealth > For Teens > Female Reproductive System Print A ... and female reproductive systems. continue What Is the Female Reproductive System? Most species have two sexes: male and female. ...

  2. Fundamental Physical Constants

    National Institute of Standards and Technology Data Gateway

    SRD 121 CODATA Fundamental Physical Constants (Web, free access)   This site, developed in the Physics Laboratory at NIST, addresses three topics: fundamental physical constants, the International System of Units (SI), which is the modern metric system, and expressing the uncertainty of measurement results.

  3. Fundamentals of Physics

    NASA Astrophysics Data System (ADS)

    Halliday, David; Resnick, Robert; Walker, Jearl

    2003-01-01

    No other book on the market today can match the success of Halliday, Resnick and Walker's Fundamentals of Physics! In a breezy, easy-to-understand style the book offers a solid understanding of fundamental physics concepts, and helps readers apply this conceptual understanding to quantitative problem solving.

  4. Rethinking reproductive "tourism" as reproductive "exile".

    PubMed

    Inhorn, Marcia C; Patrizio, Pasquale

    2009-09-01

    Whereas reproductive "tourism" implies leisure travel, reproductive "exile" bespeaks the numerous difficulties and constraints faced by infertile patients who are "forced" to travel globally for assisted reproduction. Given this reality, it is time to rethink the language of "reproductive tourism," replacing it with more accurate and patient-centered terms. PMID:19249025

  5. Influence of individual body size on reproductive traits in Melanopline grasshoppers (Orthoptera: Acrididae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Body size is a fundamental trait of an organism, affecting most aspects of its performance, including reproduction. Numerous biotic and environmental factors can influence individual body size and reproduction in grasshoppers. Using data from four experiments, I examined intraspecific relationships ...

  6. REPRODUCTIVE PHYSIOLOGY OF YELLOW PERCH (PERCA FLAVESCENS): ENVIRONMENTAL AND ENDOCRINOLOGICAL CUES

    EPA Science Inventory

    An understanding of the mechanisms involved in the regulation of reproductive processes in yellow perch is fundamental for intensive culture of this commercially important, freshwater, perciform fish. This paper describes the annual reproductive cycle of female and male perch. It...

  7. Fundaments of plant cybernetics.

    PubMed

    Zucconi, F

    2001-01-01

    A systemic approach is proposed for analyzing plants' physiological organization and cybernesis. To this end, the plant is inspected as a system, starting from the integration of crown and root systems, and its impact on a number of basic epigenetic events. The approach proves to be axiomatic and facilitates the definition of the principles behind the plant's autonomous control of growth and reproduction.

  8. Male Reproductive System

    MedlinePlus

    ... gamete, the egg or ovum , meet in the female's reproductive system to create a new individual. Both the male and female reproductive systems are essential for reproduction. Humans, like other organisms, ...

  9. Male Reproductive System

    MedlinePlus

    ... gamete, the egg or ovum, meet in the female's reproductive system to create a baby. Both the male and female reproductive systems are essential for reproduction. Humans pass certain characteristics ...

  10. Normal Female Reproductive Anatomy

    MedlinePlus

    ... hyphen, e.g. -historical Searches are case-insensitive Reproductive System, Female, Anatomy Add to My Pictures View /Download : Small: ... Reproductive System, Female, Anatomy Description: Anatomy of the female reproductive system; drawing shows the uterus, myometrium (muscular outer layer ...

  11. Female Reproductive System

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Female Reproductive System KidsHealth > For Parents > Female Reproductive System Print A ... the egg or sperm. continue Components of the Female Reproductive System Unlike the male, the human female has a ...

  12. Variation of Fundamental Constants

    NASA Astrophysics Data System (ADS)

    Flambaum, V. V.

    2006-11-01

    Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. The spatial variation can explain a fine tuning of the fundamental constants which allows humans (and any life) to appear. We appeared in the area of the Universe where the values of the fundamental constants are consistent with our existence. We present a review of recent works devoted to the variation of the fine structure constant α, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra. Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feshbach resonance.

  13. Monte Carlo fundamentals

    SciTech Connect

    Brown, F.B.; Sutton, T.M.

    1996-02-01

    This report is composed of the lecture notes from the first half of a 32-hour graduate-level course on Monte Carlo methods offered at KAPL. These notes, prepared by two of the principle developers of KAPL`s RACER Monte Carlo code, cover the fundamental theory, concepts, and practices for Monte Carlo analysis. In particular, a thorough grounding in the basic fundamentals of Monte Carlo methods is presented, including random number generation, random sampling, the Monte Carlo approach to solving transport problems, computational geometry, collision physics, tallies, and eigenvalue calculations. Furthermore, modern computational algorithms for vector and parallel approaches to Monte Carlo calculations are covered in detail, including fundamental parallel and vector concepts, the event-based algorithm, master/slave schemes, parallel scaling laws, and portability issues.

  14. Arguing against fundamentality

    NASA Astrophysics Data System (ADS)

    McKenzie, Kerry

    This paper aims to open up discussion on the relationship between fundamentality and naturalism, and in particular on the question of whether fundamentality may be denied on naturalistic grounds. A historico-inductive argument for an anti-fundamentalist conclusion, prominent within the contemporary metaphysical literature, is examined; finding it wanting, an alternative 'internal' strategy is proposed. By means of an example from the history of modern physics - namely S-matrix theory - it is demonstrated that (1) this strategy can generate similar (though not identical) anti-fundamentalist conclusions on more defensible naturalistic grounds, and (2) that fundamentality questions can be empirical questions. Some implications and limitations of the proposed approach are discussed.

  15. Fundamentals of fluid lubrication

    NASA Technical Reports Server (NTRS)

    Hamrock, Bernard J.

    1991-01-01

    The aim is to coordinate the topics of design, engineering dynamics, and fluid dynamics in order to aid researchers in the area of fluid film lubrication. The lubrication principles that are covered can serve as a basis for the engineering design of machine elements. The fundamentals of fluid film lubrication are presented clearly so that students that use the book will have confidence in their ability to apply these principles to a wide range of lubrication situations. Some guidance on applying these fundamentals to the solution of engineering problems is also provided.

  16. Fundamentals of fluid sealing

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1976-01-01

    The fundamentals of fluid sealing, including seal operating regimes, are discussed and the general fluid-flow equations for fluid sealing are developed. Seal performance parameters such as leakage and power loss are presented. Included in the discussion are the effects of geometry, surface deformations, rotation, and both laminar and turbulent flows. The concept of pressure balancing is presented, as are differences between liquid and gas sealing. Mechanisms of seal surface separation, fundamental friction and wear concepts applicable to seals, seal materials, and pressure-velocity (PV) criteria are discussed.

  17. Reading Is Fundamental, 1977.

    ERIC Educational Resources Information Center

    Smithsonian Institution, Washington, DC. National Reading is Fun-damental Program.

    Reading Is Fundamental (RIF) is a national, nonprofit organization designed to motivate children to read by making a wide variety of inexpensive books available to them and allowing the children to choose and keep books that interest them. This annual report for 1977 contains the following information on the RIF project: an account of the…

  18. Fundamentals of Chemical Processes.

    ERIC Educational Resources Information Center

    Moser, William R.

    1985-01-01

    Describes a course that provides students with a fundamental understanding of the chemical, catalytic, and engineering sciences related to the chemical reactions taking place in a variety of reactors of different configurations. Also describes the eight major lecture topics, course examinations, and term papers. The course schedule is included.…

  19. Unification of Fundamental Forces

    NASA Astrophysics Data System (ADS)

    Salam, Abdus; Taylor, Foreword by John C.

    2005-10-01

    Foreword John C. Taylor; 1. Unification of fundamental forces Abdus Salam; 2. History unfolding: an introduction to the two 1968 lectures by W. Heisenberg and P. A. M. Dirac Abdus Salam; 3. Theory, criticism, and a philosophy Werner Heisenberg; 4. Methods in theoretical physics Paul Adrian Maurice Dirac.

  20. Fundamentals of Diesel Engines.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This student guide, one of a series of correspondence training courses designed to improve the job performance of members of the Marine Corps, deals with the fundamentals of diesel engine mechanics. Addressed in the three individual units of the course are the following topics: basic principles of diesel mechanics; principles, mechanics, and…

  1. Fundamentals of Library Instruction

    ERIC Educational Resources Information Center

    McAdoo, Monty L.

    2012-01-01

    Being a great teacher is part and parcel of being a great librarian. In this book, veteran instruction services librarian McAdoo lays out the fundamentals of the discipline in easily accessible language. Succinctly covering the topic from top to bottom, he: (1) Offers an overview of the historical context of library instruction, drawing on recent…

  2. Homeschooling and Religious Fundamentalism

    ERIC Educational Resources Information Center

    Kunzman, Robert

    2010-01-01

    This article considers the relationship between homeschooling and religious fundamentalism by focusing on their intersection in the philosophies and practices of conservative Christian homeschoolers in the United States. Homeschooling provides an ideal educational setting to support several core fundamentalist principles: resistance to…

  3. Food Service Fundamentals.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    Developed as part of the Marine Corps Institute (MCI) correspondence training program, this course on food service fundamentals is designed to provide a general background in the basic aspects of the food service program in the Marine Corps; it is adaptable for nonmilitary instruction. Introductory materials include specific information for MCI…

  4. Laser Fundamentals and Experiments.

    ERIC Educational Resources Information Center

    Van Pelt, W. F.; And Others

    As a result of work performed at the Southwestern Radiological Health Laboratory with respect to lasers, this manual was prepared in response to the increasing use of lasers in high schools and colleges. It is directed primarily toward the high school instructor who may use the text for a short course in laser fundamentals. The definition of the…

  5. Selfish goals serve more fundamental social and biological goals.

    PubMed

    Becker, D Vaughn; Kenrick, Douglas T

    2014-04-01

    Proximate selfish goals reflect the machinations of more fundamental goals such as self-protection and reproduction. Evolutionary life history theory allows us to make predictions about which goals are prioritized over others, which stimuli release which goals, and how the stages of cognitive processing are selectively influenced to better achieve the aims of those goals.

  6. Fundamentals of Polarized Light

    NASA Technical Reports Server (NTRS)

    Mishchenko, Michael

    2003-01-01

    The analytical and numerical basis for describing scattering properties of media composed of small discrete particles is formed by the classical electromagnetic theory. Although there are several excellent textbooks outlining the fundamentals of this theory, it is convenient for our purposes to begin with a summary of those concepts and equations that are central to the subject of this book and will be used extensively in the following chapters. We start by formulating Maxwell's equations and constitutive relations for time- harmonic macroscopic electromagnetic fields and derive the simplest plane-wave solution that underlies the basic optical idea of a monochromatic parallel beam of light. This solution naturally leads to the introduction of such fundamental quantities as the refractive index and the Stokes parameters. Finally, we define the concept of a quasi-monochromatic beam of light and discuss its implications.

  7. Fundamental studies in geodynamics

    NASA Technical Reports Server (NTRS)

    Anderson, D. L.; Hager, B. H.; Kanamori, H.

    1981-01-01

    Research in fundamental studies in geodynamics continued in a number of fields including seismic observations and analysis, synthesis of geochemical data, theoretical investigation of geoid anomalies, extensive numerical experiments in a number of geodynamical contexts, and a new field seismic volcanology. Summaries of work in progress or completed during this report period are given. Abstracts of publications submitted from work in progress during this report period are attached as an appendix.

  8. Value of Fundamental Science

    NASA Astrophysics Data System (ADS)

    Burov, Alexey

    Fundamental science is a hard, long-term human adventure that has required high devotion and social support, especially significant in our epoch of Mega-science. The measure of this devotion and this support expresses the real value of the fundamental science in public opinion. Why does fundamental science have value? What determines its strength and what endangers it? The dominant answer is that the value of science arises out of curiosity and is supported by the technological progress. Is this really a good, astute answer? When trying to attract public support, we talk about the ``mystery of the universe''. Why do these words sound so attractive? What is implied by and what is incompatible with them? More than two centuries ago, Immanuel Kant asserted an inseparable entanglement between ethics and metaphysics. Thus, we may ask: which metaphysics supports the value of scientific cognition, and which does not? Should we continue to neglect the dependence of value of pure science on metaphysics? If not, how can this issue be addressed in the public outreach? Is the public alienated by one or another message coming from the face of science? What does it mean to be politically correct in this sort of discussion?

  9. Fundamental "Uncertainty" in Science

    NASA Astrophysics Data System (ADS)

    Reichl, Linda E.

    The conference on "Uncertainty and Surprise" was concerned with our fundamental inability to predict future events. How can we restructure organizations to effectively function in an uncertain environment? One concern is that many large complex organizations are built on mechanical models, but mechanical models cannot always respond well to "surprises." An underlying assumption a bout mechanical models is that, if we give them enough information about the world, they will know the future accurately enough that there will be few or no surprises. The assumption is that the future is basically predictable and deterministic.

  10. Fundamental experiments in velocimetry

    SciTech Connect

    Briggs, Matthew Ellsworth; Hull, Larry; Shinas, Michael

    2009-01-01

    One can understand what velocimetry does and does not measure by understanding a few fundamental experiments. Photon Doppler Velocimetry (PDV) is an interferometer that will produce fringe shifts when the length of one of the legs changes, so we might expect the fringes to change whenever the distance from the probe to the target changes. However, by making PDV measurements of tilted moving surfaces, we have shown that fringe shifts from diffuse surfaces are actually measured only from the changes caused by the component of velocity along the beam. This is an important simplification in the interpretation of PDV results, arising because surface roughness randomizes the scattered phases.

  11. Towards a broader concept of reproductive rights.

    PubMed

    Gallardo, A A

    1994-01-01

    Although women have for centuries acted upon the belief that control over their bodies, fertility, and health should be in their hands, the formalization of this belief in the concept of reproductive rights is relatively recent. Founded in 1978, the Women's Global Network for Reproductive Rights defined reproductive rights as women's right to decide whether, when, and how to have children irrespective of nationality, class, ethnicity, race, age, religion, disability, sexuality, or marital status in the social, economic, and political conditions which make such decisions possible. The promotion of reproductive rights as fundamental to women's achievement of a just status in society had become a worldwide goal of women's rights activists by the time of the UN Decade of Women Conference in 1985. The specific issues and strategies contained within the concept, however, remain a matter of debate. What is meant by reproductive rights may differ according to the country of one's origin, the socioeconomic status of the women at issue, political factors, and the extent to which problems such as AIDS, drug addiction, and endemic poverty are a concern. The author considers reproductive rights as human rights, feminist arguments on the human rights approach, feminist principles of women's reproductive rights, the draft International Conference on Population and Development program of action, and population policy and women's health.

  12. Testing Our Fundamental Assumptions

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    Science is all about testing the things we take for granted including some of the most fundamental aspects of how we understand our universe. Is the speed of light in a vacuum the same for all photons regardless of their energy? Is the rest mass of a photon actually zero? A series of recent studies explore the possibility of using transient astrophysical sources for tests!Explaining Different Arrival TimesArtists illustration of a gamma-ray burst, another extragalactic transient, in a star-forming region. [NASA/Swift/Mary Pat Hrybyk-Keith and John Jones]Suppose you observe a distant transient astrophysical source like a gamma-ray burst, or a flare from an active nucleus and two photons of different energies arrive at your telescope at different times. This difference in arrival times could be due to several different factors, depending on how deeply you want to question some of our fundamental assumptions about physics:Intrinsic delayThe photons may simply have been emitted at two different times by the astrophysical source.Delay due to Lorentz invariance violationPerhaps the assumption that all massless particles (even two photons with different energies) move at the exact same velocity in a vacuum is incorrect.Special-relativistic delayMaybe there is a universal speed for massless particles, but the assumption that photons have zero rest mass is wrong. This, too, would cause photon velocities to be energy-dependent.Delay due to gravitational potentialPerhaps our understanding of the gravitational potential that the photons experience as they travel is incorrect, also causing different flight times for photons of different energies. This would mean that Einsteins equivalence principle, a fundamental tenet of general relativity (GR), is incorrect.If we now turn this problem around, then by measuring the arrival time delay between photons of different energies from various astrophysical sources the further away, the better we can provide constraints on these

  13. Fundamentals of electrokinetics

    NASA Astrophysics Data System (ADS)

    Kozak, M. W.

    The study of electrokinetics is a very mature field. Experimental studies date from the early 1800s, and acceptable theoretical analyses have existed since the early 1900s. The use of electrokinetics in practical field problems is more recent, but it is still quite mature. Most developments in the fundamental understanding of electrokinetics are in the colloid science literature. A significant and increasing divergence between the theoretical understanding of electrokinetics found in the colloid science literature and the theoretical analyses used in interpreting applied experimental studies in soil science and waste remediation has developed. The soil science literature has to date restricted itself to the use of very early theories, with their associated limitations. The purpose of this contribution is to review fundamental aspects of electrokinetic phenomena from a colloid science viewpoint. It is hoped that a bridge can be built between the two branches of the literature, from which both will benefit. Attention is paid to special topics such as the effects of overlapping double layers, applications in unsaturated soils, the influence of dispersivity, and the differences between electrokinetic theory and conductivity theory.

  14. [Sexual reproduction in animals].

    PubMed

    Jordana, R; Herrea, L

    1974-01-01

    Both asexual and sexual reproduction are described, with most attention given the latter, and all basic aspects of reproduction are discussed including gender, gametogenesis, genes and chromosomes, fecundation, and hormonal control. Female and male reproductive hormones and their modes of operation are given special attention. Innate reproductive and sexual behavior in various species is detailed and a discussion of the role of sexual attraction in human and animal reproduction is included. Contraception and abortion are described as human efforts to separate sexuality and reproduction unique in the biological world.

  15. Fundamentals of Geophysics

    NASA Astrophysics Data System (ADS)

    Lowrie, William

    1997-10-01

    This unique textbook presents a comprehensive overview of the fundamental principles of geophysics. Unlike most geophysics textbooks, it combines both the applied and theoretical aspects to the subject. The author explains complex geophysical concepts using abundant diagrams, a simplified mathematical treatment, and easy-to-follow equations. After placing the Earth in the context of the solar system, he describes each major branch of geophysics: gravitation, seismology, dating, thermal and electrical properties, geomagnetism, paleomagnetism and geodynamics. Each chapter begins with a summary of the basic physical principles, and a brief account of each topic's historical evolution. The book will satisfy the needs of intermediate-level earth science students from a variety of backgrounds, while at the same time preparing geophysics majors for continued study at a higher level.

  16. Wall of fundamental constants

    SciTech Connect

    Olive, Keith A.; Peloso, Marco; Uzan, Jean-Philippe

    2011-02-15

    We consider the signatures of a domain wall produced in the spontaneous symmetry breaking involving a dilatonlike scalar field coupled to electromagnetism. Domains on either side of the wall exhibit slight differences in their respective values of the fine-structure constant, {alpha}. If such a wall is present within our Hubble volume, absorption spectra at large redshifts may or may not provide a variation in {alpha} relative to the terrestrial value, depending on our relative position with respect to the wall. This wall could resolve the contradiction between claims of a variation of {alpha} based on Keck/Hires data and of the constancy of {alpha} based on Very Large Telescope data. We derive the properties of the wall and the parameters of the underlying microscopic model required to reproduce the possible spatial variation of {alpha}. We discuss the constraints on the existence of the low-energy domain wall and describe its observational implications concerning the variation of the fundamental constants.

  17. Fundamentals in Nuclear Physics

    NASA Astrophysics Data System (ADS)

    Basdevant, Jean-Louis, Rich, James, Spiro, Michael

    This course on nuclear physics leads the reader to the exploration of the field from nuclei to astrophysical issues. Much nuclear phenomenology can be understood from simple arguments such as those based on the Pauli principle and the Coulomb barrier. This book is concerned with extrapolating from such arguments and illustrating nuclear systematics with experimental data. Starting with the basic concepts in nuclear physics, nuclear models, and reactions, the book covers nuclear decays and the fundamental electro-weak interactions, radioactivity, and nuclear energy. After the discussions of fission and fusion leading into nuclear astrophysics, there is a presentation of the latest ideas about cosmology. As a primer this course will lay the foundations for more specialized subjects. This book emerged from a series of topical courses the authors delivered at the Ecole Polytechnique and will be useful for graduate students and for scientists in a variety of fields.

  18. Fundamentals of zoological scaling

    NASA Astrophysics Data System (ADS)

    Lin, Herbert

    1982-01-01

    Most introductory physics courses emphasize highly idealized problems with unique well-defined answers. Though many textbooks complement these problems with estimation problems, few books present anything more than an elementary discussion of scaling. This paper presents some fundamentals of scaling in the zoological domain—a domain complex by any standard, but one also well suited to illustrate the power of very simple physical ideas. We consider the following animal characteristics: skeletal weight, speed of running, height and range of jumping, food consumption, heart rate, lifetime, locomotive efficiency, frequency of wing flapping, and maximum sizes of animals that fly and hover. These relationships are compared to zoological data and everyday experience, and match reasonably well.

  19. Reproductive Information and Reproductive Decision-Making.

    PubMed

    Mehlman, Maxwell J

    2015-01-01

    Opponents of reproductive choice are attempting to limit reproductive decisions based on certain underlying reasons. This commentary explores the rationales for these limitations and the objections to them. It concludes that reasoned-based limitations are unsupportable and unenforceable. PMID:26242944

  20. Testing Our Fundamental Assumptions

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    Science is all about testing the things we take for granted including some of the most fundamental aspects of how we understand our universe. Is the speed of light in a vacuum the same for all photons regardless of their energy? Is the rest mass of a photon actually zero? A series of recent studies explore the possibility of using transient astrophysical sources for tests!Explaining Different Arrival TimesArtists illustration of a gamma-ray burst, another extragalactic transient, in a star-forming region. [NASA/Swift/Mary Pat Hrybyk-Keith and John Jones]Suppose you observe a distant transient astrophysical source like a gamma-ray burst, or a flare from an active nucleus and two photons of different energies arrive at your telescope at different times. This difference in arrival times could be due to several different factors, depending on how deeply you want to question some of our fundamental assumptions about physics:Intrinsic delayThe photons may simply have been emitted at two different times by the astrophysical source.Delay due to Lorentz invariance violationPerhaps the assumption that all massless particles (even two photons with different energies) move at the exact same velocity in a vacuum is incorrect.Special-relativistic delayMaybe there is a universal speed for massless particles, but the assumption that photons have zero rest mass is wrong. This, too, would cause photon velocities to be energy-dependent.Delay due to gravitational potentialPerhaps our understanding of the gravitational potential that the photons experience as they travel is incorrect, also causing different flight times for photons of different energies. This would mean that Einsteins equivalence principle, a fundamental tenet of general relativity (GR), is incorrect.If we now turn this problem around, then by measuring the arrival time delay between photons of different energies from various astrophysical sources the further away, the better we can provide constraints on these

  1. Reproductive tract microbiome in assisted reproductive technologies.

    PubMed

    Franasiak, Jason M; Scott, Richard T

    2015-12-01

    The human microbiome has gained much attention recently for its role in health and disease. This interest has come as we have begun to scratch the surface of the complexity of what has been deemed to be our "second genome" through initiatives such as the Human Microbiome Project. Microbes have been hypothesized to be involved in the physiology and pathophysiology of assisted reproduction since before the first success in IVF. Although the data supporting or refuting this hypothesis remain somewhat sparse, thanks to sequencing data from the 16S rRNA subunit, we have begun to characterize the microbiome in the male and female reproductive tracts and understand how this may play a role in reproductive competence. In this review, we discuss what is known about the microbiome of the reproductive tract as it pertains to assisted reproductive technologies.

  2. Male Reproductive System

    MedlinePlus

    ... Surveillance Modules » Anatomy & Physiology » Reproductive System » Male Reproductive System Cancer Registration & Surveillance Modules Anatomy & Physiology Intro to the Human Body Body Functions & Life Process Anatomical Terminology Review Quiz ...

  3. Men's Reproductive Health

    MedlinePlus

    ... NICHD Research Information Clinical Trials Resources and Publications Men's Reproductive Health: Overview Skip sharing on social media ... Content Reproductive health is an important component of men's overall health and well-being. Too often, males ...

  4. Factors affecting the reproductive success of dominant male meerkats.

    PubMed

    Spong, Göran F; Hodge, Sarah J; Young, Andrew J; Clutton-Brock, Tim H

    2008-05-01

    Identifying traits that affect the reproductive success of individuals is fundamental for our understanding of evolutionary processes. In cooperative breeders, a dominant male typically restricts mating access to the dominant female for extended periods, resulting in pronounced variation in reproductive success among males. This may result in strong selection for traits that increase the likelihood of dominance acquisition, dominance retention and reproductive rates while dominant. However, despite considerable research on reproductive skew, few studies have explored the factors that influence these three processes among males in cooperative species. Here we use genetic, behavioural and demographic data to investigate the factors affecting reproductive success in dominant male meerkats (Suricata suricatta). Our data show that dominant males sire the majority of all offspring surviving to 1 year. A male's likelihood of becoming dominant is strongly influenced by age, but not by weight. Tenure length and reproductive rate, both important components of dominant male reproductive success, are largely affected by group size and composition, rather than individual traits. Dominant males in large groups have longer tenures, but after this effect is controlled, male tenure length also correlates negatively to the number of adult females in the group. Male reproductive rate also declines as the number of intra- and extra-group competitors increases. As the time spent in the dominant position and reproductive rate while dominant explain > 80% of the total variance in reproductive success, group composition thus has major implications for male reproductive success.

  5. Factors affecting the reproductive success of dominant male meerkats.

    PubMed

    Spong, Göran F; Hodge, Sarah J; Young, Andrew J; Clutton-Brock, Tim H

    2008-05-01

    Identifying traits that affect the reproductive success of individuals is fundamental for our understanding of evolutionary processes. In cooperative breeders, a dominant male typically restricts mating access to the dominant female for extended periods, resulting in pronounced variation in reproductive success among males. This may result in strong selection for traits that increase the likelihood of dominance acquisition, dominance retention and reproductive rates while dominant. However, despite considerable research on reproductive skew, few studies have explored the factors that influence these three processes among males in cooperative species. Here we use genetic, behavioural and demographic data to investigate the factors affecting reproductive success in dominant male meerkats (Suricata suricatta). Our data show that dominant males sire the majority of all offspring surviving to 1 year. A male's likelihood of becoming dominant is strongly influenced by age, but not by weight. Tenure length and reproductive rate, both important components of dominant male reproductive success, are largely affected by group size and composition, rather than individual traits. Dominant males in large groups have longer tenures, but after this effect is controlled, male tenure length also correlates negatively to the number of adult females in the group. Male reproductive rate also declines as the number of intra- and extra-group competitors increases. As the time spent in the dominant position and reproductive rate while dominant explain > 80% of the total variance in reproductive success, group composition thus has major implications for male reproductive success. PMID:18410290

  6. IEC is fundamental.

    PubMed

    1994-02-01

    China's information, education, and communication [IEC] as part of the family planning program has been successful in Shaoxing County, Ningbo-Shaoxing Plain, Zhejiang Province: total 1992 population of 942.8 thousand, birth rate 14/1000, rate of natural increase 7/1000, and planned births 99%. Population education has been an important component of IEC and focuses on population theory, population policy, and population regulation through family planning. Organized workshops are available at the country level for training village leaders. There is inservice training of new administrators of family planning programs. Media has been used to promote the benefits of family planning for the state and families. Many couples have received only-child certificates, and many couples with permission to have a second child have willingly forfeited that opportunity. Recognition has been given to 300 units that have advanced and created better social environments. There has been an integration of ideological education and popular contraceptive knowledge. Reproductive and contraceptive knowledge has been enhanced through many lectures and training classes on producing healthy children, premarital planning, and pregnancy care. The country broadcasting station gives lectures on family planning. There is a family planning guidance station that provides counseling and publicity on commonly used methods. Social welfare projects are vigorously developed, such as old age homes in villages and kindergartens. Insurance plans have been initiated. Good contraceptive service provision and prenatal care are jointly part of the family planning programs. New methods such as the IUD have been successfully introduced and accepted by the population. IUD users since 1987 now number $6,581.

  7. Acupuncture for reproductive disorders.

    PubMed

    Lin, J H; Panzer, R

    1992-03-01

    The use of acupuncture to treat reproductive disorders can produce excellent results. Two proposed physiologic mechanisms for its effects on the reproductive system include an endorphin-mediated mechanism affecting the hypothalamic-pituitary-gonadal endocrine axis and a direct effect on gonadal paracrine and autocrine control of steroidogenesis. This chapter discusses reproductive disorders from both western and traditional Chinese perspectives, and details the use of acupuncture for the treatment of eight specific categories of reproductive dysfunction.

  8. Overlay accuracy fundamentals

    NASA Astrophysics Data System (ADS)

    Kandel, Daniel; Levinski, Vladimir; Sapiens, Noam; Cohen, Guy; Amit, Eran; Klein, Dana; Vakshtein, Irina

    2012-03-01

    Currently, the performance of overlay metrology is evaluated mainly based on random error contributions such as precision and TIS variability. With the expected shrinkage of the overlay metrology budget to < 0.5nm, it becomes crucial to include also systematic error contributions which affect the accuracy of the metrology. Here we discuss fundamental aspects of overlay accuracy and a methodology to improve accuracy significantly. We identify overlay mark imperfections and their interaction with the metrology technology, as the main source of overlay inaccuracy. The most important type of mark imperfection is mark asymmetry. Overlay mark asymmetry leads to a geometrical ambiguity in the definition of overlay, which can be ~1nm or less. It is shown theoretically and in simulations that the metrology may enhance the effect of overlay mark asymmetry significantly and lead to metrology inaccuracy ~10nm, much larger than the geometrical ambiguity. The analysis is carried out for two different overlay metrology technologies: Imaging overlay and DBO (1st order diffraction based overlay). It is demonstrated that the sensitivity of DBO to overlay mark asymmetry is larger than the sensitivity of imaging overlay. Finally, we show that a recently developed measurement quality metric serves as a valuable tool for improving overlay metrology accuracy. Simulation results demonstrate that the accuracy of imaging overlay can be improved significantly by recipe setup optimized using the quality metric. We conclude that imaging overlay metrology, complemented by appropriate use of measurement quality metric, results in optimal overlay accuracy.

  9. Fundamentals of Atmospheric Radiation

    NASA Astrophysics Data System (ADS)

    Bohren, Craig F.; Clothiaux, Eugene E.

    2006-02-01

    This textbook fills a gap in the literature for teaching material suitable for students of atmospheric science and courses on atmospheric radiation. It covers the fundamentals of emission, absorption, and scattering of electromagnetic radiation from ultraviolet to infrared and beyond. Much of the book applies to planetary atmosphere. The authors are physicists and teach at the largest meteorology department of the US at Penn State. Craig T. Bohren has taught the atmospheric radiation course there for the past 20 years with no book. Eugene Clothiaux has taken over and added to the course notes. Problems given in the text come from students, colleagues, and correspondents. The design of the figures especially for this book is meant to ease comprehension. Discussions have a graded approach with a thorough treatment of subjects, such as single scattering by particles, at different levels of complexity. The discussion of the multiple scattering theory begins with piles of plates. This simple theory introduces concepts in more advanced theories, i.e. optical thickness, single-scattering albedo, asymmetry parameter. The more complicated theory, the two-stream theory, then takes the reader beyond the pile-of-plates theory. Ideal for advanced undergraduate and graduate students of atmospheric science.

  10. Preconception care: promoting reproductive planning

    PubMed Central

    2014-01-01

    Introduction Preconception care recognizes that many adolescent girls and young women will be thrust into motherhood without the knowledge, skills or support they need. Sixty million adolescents give birth each year worldwide, even though pregnancy in adolescence has mortality rates at least twice as high as pregnancy in women aged 20-29 years. Reproductive planning and contraceptive use can prevent unintended pregnancies, unsafe abortions and sexually-transmitted infections in adolescent girls and women. Smaller families also mean better nutrition and development opportunities, yet 222 million couples continue to lack access to modern contraception. Method A systematic review and meta-analysis of the evidence was conducted to ascertain the possible impact of preconception care for adolescents, women and couples of reproductive age on MNCH outcomes. A comprehensive strategy was used to search electronic reference libraries, and both observational and clinical controlled trials were included. Cross-referencing and a separate search strategy for each preconception risk and intervention ensured wider study capture. Results Comprehensive interventions can prevent first pregnancy in adolescence by 15% and repeat adolescent pregnancy by 37%. Such interventions should address underlying social and community factors, include sexual and reproductive health services, contraceptive provision; personal development programs and emphasizes completion of education. Appropriate birth spacing (18-24 months from birth to next pregnancy compared to short intervals <6 months) can significantly lower maternal mortality, preterm births, stillbirths, low birth weight and early neonatal deaths. Conclusion Improving adolescent health and preventing adolescent pregnancy; and promotion of birth spacing through increasing correct and consistent use of effective contraception are fundamental to preconception care. Promoting reproductive planning on a wider scale is closely interlinked with the

  11. Reproduction (II): Human Control of Reproductive Processes

    ERIC Educational Resources Information Center

    Jost, Alfred

    1970-01-01

    Describes methods of intervening in reproduction of animals and humans (artificial insemination, contraception, ovular and blastodisc transplants, pre selection of sex, cloning) and discusses the social implications of their use with humans. (AL)

  12. Reproduction-related genes in the pearl oyster genome.

    PubMed

    Matsumoto, Toshie; Masaoka, Tetsuji; Fujiwara, Atsushi; Nakamura, Yoji; Satoh, Nori; Awaji, Masahiko

    2013-10-01

    Molluscan reproduction has been a target of biological research because of the various reproductive strategies that have evolved in this phylum. It has also been studied for the development of fisheries technologies, particularly aquaculture. Although fundamental processes of reproduction in other phyla, such as vertebrates and arthropods, have been well studied, information on the molecular mechanisms of molluscan reproduction remains limited. The recently released draft genome of the pearl oyster Pinctada fucata provides a novel and powerful platform for obtaining structural information on the genes and proteins involved in bivalve reproduction. In the present study, we analyzed the pearl oyster draft genome to screen reproduction-related genes. Analysis was mainly conducted for genes reported from other molluscs for encoding orthologs of reproduction-related proteins in other phyla. The gene search in the P. fucata gene models (version 1.1) and genome assembly (version 1.0) were performed using Genome Browser and BLAST software. The obtained gene models were then BLASTP searched against a public database to confirm the best-hit sequences. As a result, more than 40 gene models were identified with high accuracy to encode reproduction-related genes reported for P. fucata and other molluscs. These include vasa, nanos, doublesex- and mab-3-related transcription factor, 5-hydroxytryptamine (5-HT) receptors, vitellogenin, estrogen receptor, and others. The set of reproduction-related genes of P. fucata identified in the present study constitute a new tool for research on bivalve reproduction at the molecular level.

  13. Fundamentals of Space Medicine

    NASA Astrophysics Data System (ADS)

    Clément, Gilles

    2005-03-01

    A total of more than 240 human space flights have been completed to date, involving about 450 astronauts from various countries, for a combined total presence in space of more than 70 years. The seventh long-duration expedition crew is currently in residence aboard the International Space Station, continuing a permanent presence in space that began in October 2000. During that time, investigations have been conducted on both humans and animal models to study the bone demineralization and muscle deconditioning, space motion sickness, the causes and possible treatment of postflight orthostatic intolerance, the changes in immune function, crew and crew-ground interactions, and the medical issues of living in a space environment, such as the effects of radiation or the risk of developing kidney stones. Some results of these investigations have led to fundamental discoveries about the adaptation of the human body to the space environment. Gilles Clément has been active in this research. This readable text presents the findings from the life science experiments conducted during and after space missions. Topics discussed in this book include: adaptation of sensory-motor, cardio-vascular, bone, and muscle systems to the microgravity of spaceflight; psychological and sociological issues of living in a confined, isolated, and stressful environment; operational space medicine, such as crew selection, training and in-flight health monitoring, countermeasures and support; results of space biology experiments on individual cells, plants, and animal models; and the impact of long-duration missions such as the human mission to Mars. The author also provides a detailed description of how to fly a space experiment, based on his own experience with research projects conducted onboard Salyut-7, Mir, Spacelab, and the Space Shuttle. Now is the time to look at the future of human spaceflight and what comes next. The future human exploration of Mars captures the imagination of both the

  14. Fundamentals of Space Medicine

    NASA Astrophysics Data System (ADS)

    Clément, G.

    2003-10-01

    As of today, a total of more than 240 human space flights have been completed, involving about 450 astronauts from various countries, for a combined total presence in space of more than 70 years. The seventh long-duration expedition crew is currently in residence aboard the International Space Station, continuing a permanent presence in space that began in October 2000. During that time, investigations have been conducted on both humans and animal models to study the bone demineralization and muscle deconditioning, space motion sickness, the causes and possible treatment of postflight orthostatic intolerance, the changes in immune function, crew and crew-ground interactions, and the medical issues of living in a space environment, such as the effects of radiation or the risk of developing kidney stones. Some results of these investigations have led to fundamental discoveries about the adaptation of the human body to the space environment. Gilles Clément has been active in this research. This book presents in a readable text the findings from the life science experiments conducted during and after space missions. Topics discussed in this book include: adaptation of sensory-motor, cardiovascular, bone and muscle systems to the microgravity of spaceflight; psychological and sociological issues of living in a confined, isolated and stressful environment; operational space medicine, such as crew selection, training and in-flight health monitoring, countermeasures and support; results of space biology experiments on individual cells, plants, and animal models; and the impact of long-duration missions such as the human mission to Mars. The author also provides a detailed description of how to fly a space experiment, based on his own experience with research projects conducted onboard Salyut-7, Mir, Spacelab, and the Space Shuttle. Now is the time to look at the future of human spaceflight and what comes next. The future human exploration of Mars captures the imagination

  15. Fundamentals of phosphate transfer.

    PubMed

    Kirby, Anthony J; Nome, Faruk

    2015-07-21

    Historically, the chemistry of phosphate transfer-a class of reactions fundamental to the chemistry of Life-has been discussed almost exclusively in terms of the nucleophile and the leaving group. Reactivity always depends significantly on both factors; but recent results for reactions of phosphate triesters have shown that it can also depend strongly on the nature of the nonleaving or "spectator" groups. The extreme stabilities of fully ionised mono- and dialkyl phosphate esters can be seen as extensions of the same effect, with one or two triester OR groups replaced by O(-). Our chosen lead reaction is hydrolysis-phosphate transfer to water: because water is the medium in which biological chemistry takes place; because the half-life of a system in water is an accepted basic index of stability; and because the typical mechanisms of hydrolysis, with solvent H2O providing specific molecules to act as nucleophiles and as general acids or bases, are models for reactions involving better nucleophiles and stronger general species catalysts. Not least those available in enzyme active sites. Alkyl monoester dianions compete with alkyl diester monoanions for the slowest estimated rates of spontaneous hydrolysis. High stability at physiological pH is a vital factor in the biological roles of organic phosphates, but a significant limitation for experimental investigations. Almost all kinetic measurements of phosphate transfer reactions involving mono- and diesters have been followed by UV-visible spectroscopy using activated systems, conveniently compounds with good leaving groups. (A "good leaving group" OR* is electron-withdrawing, and can be displaced to generate an anion R*O(-) in water near pH 7.) Reactivities at normal temperatures of P-O-alkyl derivatives-better models for typical biological substrates-have typically had to be estimated: by extended extrapolation from linear free energy relationships, or from rate measurements at high temperatures. Calculation is free

  16. Maximum Entropy Fundamentals

    NASA Astrophysics Data System (ADS)

    Harremoeës, P.; Topsøe, F.

    2001-09-01

    In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over the development of natural

  17. Bubaline versus bovine reproduction.

    PubMed

    Drost, M

    2007-08-01

    Fertility in water buffalo (Bubalus bubalis) is considerably lower than that in cattle (Bos taurus and Bos indicus). Poor breeding efficiency is attributed to late onset of puberty, seasonality, poor estrus expression, and long calving intervals. Accurate estrus detection is a prerequisite for efficient reproductive management. Established reproductive management techniques in cattle can be successfully applied to water buffalo because of the similarities in the anatomy, physiology, and endocrinology of reproduction between the two genera.

  18. Advances in reproductive biotechnologies.

    PubMed

    Choudhary, K K; Kavya, K M; Jerome, A; Sharma, R K

    2016-04-01

    In recent times, reproductive biotechnologies have emerged and started to replace the conventional techniques. It is noteworthy that for sustained livestock productivity, it is imperative to start using these techniques for facing the increasing challenges for productivity, reproduction and health with impending environment conditions. These recent biotechniques, both in male and female, have revolutionized and opened avenues for studying and manipulating the reproductive process both in vitro and in vivo in various livestock species for improving tis efficiency. This review attempts to highlight pros and cons, on the recent developments in reproductive biotechnologies, both in male and female in livestock species. PMID:27182135

  19. Advances in reproductive biotechnologies.

    PubMed

    Choudhary, K K; Kavya, K M; Jerome, A; Sharma, R K

    2016-04-01

    In recent times, reproductive biotechnologies have emerged and started to replace the conventional techniques. It is noteworthy that for sustained livestock productivity, it is imperative to start using these techniques for facing the increasing challenges for productivity, reproduction and health with impending environment conditions. These recent biotechniques, both in male and female, have revolutionized and opened avenues for studying and manipulating the reproductive process both in vitro and in vivo in various livestock species for improving tis efficiency. This review attempts to highlight pros and cons, on the recent developments in reproductive biotechnologies, both in male and female in livestock species.

  20. Advances in reproductive biotechnologies

    PubMed Central

    Choudhary, K. K.; Kavya, K. M.; Jerome, A.; Sharma, R. K.

    2016-01-01

    In recent times, reproductive biotechnologies have emerged and started to replace the conventional techniques. It is noteworthy that for sustained livestock productivity, it is imperative to start using these techniques for facing the increasing challenges for productivity, reproduction and health with impending environment conditions. These recent biotechniques, both in male and female, have revolutionized and opened avenues for studying and manipulating the reproductive process both in vitro and in vivo in various livestock species for improving tis efficiency. This review attempts to highlight pros and cons, on the recent developments in reproductive biotechnologies, both in male and female in livestock species. PMID:27182135

  1. The evolution and consequences of sex-specific reproductive variance.

    PubMed

    Mullon, Charles; Reuter, Max; Lehmann, Laurent

    2014-01-01

    Natural selection favors alleles that increase the number of offspring produced by their carriers. But in a world that is inherently uncertain within generations, selection also favors alleles that reduce the variance in the number of offspring produced. If previous studies have established this principle, they have largely ignored fundamental aspects of sexual reproduction and therefore how selection on sex-specific reproductive variance operates. To study the evolution and consequences of sex-specific reproductive variance, we present a population-genetic model of phenotypic evolution in a dioecious population that incorporates previously neglected components of reproductive variance. First, we derive the probability of fixation for mutations that affect male and/or female reproductive phenotypes under sex-specific selection. We find that even in the simplest scenarios, the direction of selection is altered when reproductive variance is taken into account. In particular, previously unaccounted for covariances between the reproductive outputs of different individuals are expected to play a significant role in determining the direction of selection. Then, the probability of fixation is used to develop a stochastic model of joint male and female phenotypic evolution. We find that sex-specific reproductive variance can be responsible for changes in the course of long-term evolution. Finally, the model is applied to an example of parental-care evolution. Overall, our model allows for the evolutionary analysis of social traits in finite and dioecious populations, where interactions can occur within and between sexes under a realistic scenario of reproduction.

  2. Sexual Reproduction and Breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the second edition of Plant Propagation Concepts and Laboratory Exercises, we have combined the first edition chapters 36: Sexual Reproduction in Angiosperms and 37: Breeding Horticultural Plants into the present single chapter Sexual Reproduction and Breeding. These topics are so closely relate...

  3. Reproductive Physiology of Marsupials

    ERIC Educational Resources Information Center

    Sharman, G. B.

    1970-01-01

    Describes some unique features of marsupial reproduction which include (1) chromosomal sex determination, (2) reproductive system, (3) birth, (4) location, and (5) embryonic diapause. These features suggest that viviparity evolved separately in eutherian and marsupial stocks after their derivation from a common oviparous ancestor. Bibliography.…

  4. Aerial photographic reproductions

    USGS Publications Warehouse

    U.S. Geological Survey

    1971-01-01

    Geological Survey vertical aerial photography is obtained primarily for topographic and geologic mapping. Reproductions from this photography are usually satisfactory for general use. Because reproductions are not stocked, but are custom processed for each order, they cannot be returned for credit or refund.

  5. The Reproduction of Intelligence

    ERIC Educational Resources Information Center

    Meisenberg, Gerhard

    2010-01-01

    Although a negative relationship between fertility and education has been described consistently in most countries of the world, less is known about the relationship between intelligence and reproductive outcomes. Also the paths through which intelligence influences reproductive outcomes are uncertain. The present study uses the NLSY79 to analyze…

  6. Work and Reproduction

    PubMed Central

    Prossin, Albert

    1986-01-01

    This article presents a short overview of the area of work effects on reproduction. Much speculation and confusion exist in this area of the relationship between the physical and social effects of work and the health of the elements of reproduction. Fulfilling the need for increased resources for research in this challenging and interesting area is most desirable. PMID:21267324

  7. Assessment of Male Reproductive Toxicity##

    EPA Science Inventory

    This review covers all aspects of male reproductive toxicology. It begins with an overview of male reproductive biology and then transitions to the considerations of conducting male reproductive toxicology studies. We discuss multigenerational study as proposed in EPAs harmoniz...

  8. Leptin in reproduction.

    PubMed

    Caprio, M; Fabbrini, E; Isidori, A M; Aversa, A; Fabbri, A

    2001-03-01

    In mammals, the function of the reproductive system is dependent on the availability of energy in the environment. It is well established that acute modifications of energy balance modulate the hypothalamic-pituitary-gonadal axis. In several species, fasting and caloric restriction have been shown to cause the suppression of pulsatile luteinizing hormone secretion, via an inhibition of the gonadotropin-releasing hormone pulse generator. Such a mechanism probably prevents energy being wasted for reproduction. By contrast, excessive energy storage and obesity interfere with the correct regulation of the reproductive axis. The identification of leptin and leptin receptors, along with studies performed in animal models of leptin deficiency and resistance, has focused attention on the role of this molecule in reproduction, and disclosed new aspects of the relationship between energy stores, adipose tissue and reproductive function. Here, we discuss the central and peripheral effects of leptin on reproductive tissues, and try to fit a complex reality into a simplified model. In particular, the roles of leptin in reproduction at different anatomical levels and in various clinical and experimental settings are discussed.

  9. Reproductive strategies in snakes.

    PubMed Central

    Shine, Richard

    2003-01-01

    Snakes of both sexes display remarkable flexibility and diversity in their reproductive tactics. Many features of reproduction in female snakes (such as reproductive mode and frequency, seasonality and multiple mating) allow flexible maternal control. For example, females can manipulate not only the genotypes of their offspring (through mate choice or enhanced sperm competition) but also the phenotypes of their offspring (through allocation 'decisions', behavioural and physiological thermoregulation, and nest-site selection). Reliance on stored energy ('capital') to fuel breeding results in low frequencies of female reproduction and, in extreme cases, semelparity. A sophisticated vomeronasal system not only allows male snakes to locate reproductive females by following scent trails, but also facilitates pheromonally mediated mate choice by males. Male-male rivalry takes diverse forms, including female mimicry and mate guarding; combat bouts impose strong selection for large body size in males of some species. Intraspecific (geographical) variation and phenotypic plasticity in a wide array of reproductive traits (offspring size and number; reproductive frequency; incidence of multiple mating; male tactics such as mate guarding and combat; mate choice criteria) provide exceptional opportunities for future studies. PMID:12803888

  10. Human reproduction: Jewish perspectives.

    PubMed

    Schenker, Joseph G

    2013-11-01

    Developments in science and technology and corresponding clinical applications raise new religious questions, often without clear answers. The role of theology in bioethics is integral to clarify perceived attitudes toward these developments for different religious communities. The Jewish attitude towards procreation is derived from the first commandment of God to Adam to 'Be fruitful and multiply'. Judaism allows the practice of all techniques of assisted reproduction when the oocyte and spermatozoon originate from the wife and husband respectively. This paper presents the attitude of Jewish Law -- Halacha to therapeutic procedures, such as IVF-embryo transfer, spermatozoa, oocytes, embryo donation, cryopreservation of genetic material, surrogacy, posthumous reproduction, gender preselection, reproductive and therapeutic cloning.

  11. Melanocortins and reproduction.

    PubMed

    Schiöth, Helgi B; Watanobe, Hajime

    2002-02-01

    Obesity, anorexia and general body weight fluctuations cause a variety of effects on the reproductive system. Our understanding of the neuro-biological mechanisms of the connections between body weight and the reproductive axis is not especially developed despite a number of interesting physiological observations. Several reports suggest that leptin could play a key role in connecting energy balance and reproduction. The melanocortin system, involving melanocyte stimulating hormone, adrenocorticotrophic hormone, agouti related peptide and the central melanocortin 3 and 4 receptors, plays a major role in the hypothalamic regulation of energy balance. The melanocortins have also been suggested to participate in possible downstream events of the adipose cell derived hormone, leptin. Leptin has importance for several aspects of reproduction including regulation of luteinizing hormone and prolactin release. This review discusses the interplay of hypothalamic regulation of food intake and the hormones involved in the hypothalamic-pituitary-gonadal axis with special emphasis on putative roles of the melanocortin system.

  12. Programming and reproductive functioning.

    PubMed

    Davies, Michael J; Norman, Robert J

    2002-11-01

    Here, we explore the influence of fetal programming and early life exposures on lifelong reproductive health through modification of the hypothalamic-pituitary-gonadal axis. A range of programming issues are considered with examples from the literature demonstrating that environmental or nutritive exposures have a crucial role in reproductive performance, fetal growth, postnatal development and reproduction-related disease risk. We pay particular attention to recent research on associations between indicators of fetal and postnatal growth and the etiology of polycystic ovary syndrome in women. We conclude that the concept of programming can be applied to reproductive development and related health outcomes, and that the complex potential for interactions between parameters controlling fetal development and postnatal exposures invokes a need to adopt a perspective across the life course of an individual.

  13. My Reproductive Life Plan

    MedlinePlus

    ... Information For... Media Policy Makers My Reproductive Life Plan Language: English Español (Spanish) Recommend on Facebook Tweet ... use with their patients. How to Make a Plan First, think about your goals for school, for ...

  14. Teaching Plant Reproduction.

    ERIC Educational Resources Information Center

    Tolman, Marvin N., Ed.; Hardy, Garry R., Ed.

    2000-01-01

    Recommends using Amaryllis hippeastrum to teach young children about plant reproduction. Provides tips for growing these plants, discusses the fast growing rate of the plant, and explains the anatomy. (YDS)

  15. Avian reproductive physiology

    USGS Publications Warehouse

    Gee, G.F.; Gibbons, Edward F.; Durrant, Barbara S.; Demarest, Jack

    1995-01-01

    Knowledge of the many physiological factors associated with egg production , fertility, incubation, and brooding in nondomestic birds is limited. Science knows even less about reproduction in most of the 238 endangered or threatened birds. This discussion uses studies of nondomestic and, when necessary, domestic birds to describe physiological control of reproduction. Studies of the few nondomestic avian species show large variation in physiological control of reproduction. Aviculturists, in order to successfully propagate an endangered bird, must understand the bird's reproductive peculiarities. First, investigators can do studies with carefully chosen surrogate species, but eventually they need to confirm the results in the target endangered bird. Studies of reproduction in nondomestic birds increased in the last decade. Still, scientists need to do more comparative studies to understand the mechanisms that control reproduction in birds. New technologies are making it possible to study reproductive physiology of nondomestic species in less limiting ways. These technologies include telemetry to collect information without inducing stress on captives (Howey et al., 1987; Klugman, 1987), new tests for most of the humoral factors associated with reproduction, and the skill to collect small samples and manipulate birds without disrupting the physiological mechanisms (Bercovitz et al., 1985). Managers are using knowledge from these studies to improve propagation in zoological parks, private and public propagation facilities, and research institutions. Researchers need to study the control of ovulation, egg formation, and oviposition in the species of nondomestic birds that lay very few eggs in a season, hold eggs in the oviduct for longer intervals, or differ in other ways from the more thoroughly studied domestic birds. Other techniques that would enhance propagation for nondomestlc birds include tissue culture of cloned embryonic cells, cryopreservation of embryos

  16. Asexual Reproduction in Holothurians

    PubMed Central

    Dolmatov, Igor Yu.

    2014-01-01

    Aspects of asexual reproduction in holothurians are discussed. Holothurians are significant as fishery and aquaculture items and have high commercial value. The last review on holothurian asexual reproduction was published 18 years ago and included only 8 species. An analysis of the available literature shows that asexual reproduction has now been confirmed in 16 holothurian species. Five additional species are also most likely capable of fission. The recent discovery of new fissiparous holothurian species indicates that this reproduction mode is more widespread in Holothuroidea than previously believed. New data about the history of the discovery of asexual reproduction in holothurians, features of fission, and regeneration of anterior and posterior fragments are described here. Asexual reproduction is obviously controlled by the integrated systems of the organism, primarily the nervous system. Special molecular mechanisms appear to determine the location where fission occurs along the anterior-posterior axis of the body. Alteration of the connective tissue strength of the body wall may play an important role during fission of holothurians. The basic mechanism of fission is the interaction of matrix metalloproteinases, their inhibitors, and enzymes forming cross-link complexes between fibrils of collagen. The population dynamics of fissiparous holothurians are discussed. PMID:25405228

  17. Asexual reproduction in holothurians.

    PubMed

    Dolmatov, Igor Yu

    2014-01-01

    Aspects of asexual reproduction in holothurians are discussed. Holothurians are significant as fishery and aquaculture items and have high commercial value. The last review on holothurian asexual reproduction was published 18 years ago and included only 8 species. An analysis of the available literature shows that asexual reproduction has now been confirmed in 16 holothurian species. Five additional species are also most likely capable of fission. The recent discovery of new fissiparous holothurian species indicates that this reproduction mode is more widespread in Holothuroidea than previously believed. New data about the history of the discovery of asexual reproduction in holothurians, features of fission, and regeneration of anterior and posterior fragments are described here. Asexual reproduction is obviously controlled by the integrated systems of the organism, primarily the nervous system. Special molecular mechanisms appear to determine the location where fission occurs along the anterior-posterior axis of the body. Alteration of the connective tissue strength of the body wall may play an important role during fission of holothurians. The basic mechanism of fission is the interaction of matrix metalloproteinases, their inhibitors, and enzymes forming cross-link complexes between fibrils of collagen. The population dynamics of fissiparous holothurians are discussed.

  18. Gauge unification of fundamental forces

    NASA Astrophysics Data System (ADS)

    Salam, Abdus

    The following sections are included: * I. Fundamental Particles, Fundamental Forces, and Gauge Unification * II. The Emergence of Spontaneously Broken SU(2)×U(1) Gauge Theory * III. The Present and Its Problems * IV. Direct Extrapolation from the Electroweak to the Electronuclear * A. The three ideas * B. Tests of electronuclear grand unification * V. Elementarity: Unification with Gravity and Nature of Charge * A. The quest for elementarity, prequarks (preons and pre-preons * B. Post-Planck physics, supergravity, and Einstein's dreams * C. Extended supergravity, SU(8) preons, and composite gauge fields * Appendix A: Examples of Grand Unifying Groups * Appendix B: Does the Grand Plateau really exist * References

  19. Glucocorticoid Regulation of Reproduction.

    PubMed

    Geraghty, Anna C; Kaufer, Daniela

    2015-01-01

    It is well accepted that stress, measured by increased glucocorticoid secretion, leads to profound reproductive dysfunction. In times of stress, glucocorticoids activate many parts of the fight or flight response, mobilizing energy and enhancing survival, while inhibiting metabolic processes that are not necessary for survival in the moment. This includes reproduction, an energetically costly procedure that is very finely regulated. In the short term, this is meant to be beneficial, so that the organism does not waste precious energy needed for survival. However, long-term inhibition can lead to persistent reproductive dysfunction, even if no longer stressed. This response is mediated by the increased levels of circulating glucocorticoids, which orchestrate complex inhibition of the entire reproductive axis. Stress and glucocorticoids exhibits both central and peripheral inhibition of the reproductive hormonal axis. While this has long been recognized as an issue, understanding the complex signaling mechanism behind this inhibition remains somewhat of a mystery. What makes this especially difficult is attempting to differentiate the many parts of both of these hormonal axes, and new neuropeptide discoveries in the last decade in the reproductive field have added even more complexity to an already complicated system. Glucocorticoids (GCs) and other hormones within the hypothalamic-pituitary-adrenal (HPA) axis (as well as contributors in the sympathetic system) can modulate the hypothalamic-pituitary-gonadal (HPG) axis at all levels-GCs can inhibit release of GnRH from the hypothalamus, inhibit gonadotropin synthesis and release in the pituitary, and inhibit testosterone synthesis and release from the gonads, while also influencing gametogenesis and sexual behavior. This chapter is not an exhaustive review of all the known literature, however is aimed at giving a brief look at both the central and peripheral effects of glucocorticoids on the reproductive function.

  20. New constitutionalism and the social reproduction of caring institutions.

    PubMed

    Gill, Stephen; Bakker, Isabella

    2006-01-01

    This essay analyzes neo-liberal economic agreements and legal and political frameworks or what has been called the "new constitutionalism," a governance framework that empowers market forces to reshape economic and social development worldwide. The article highlights some consequences of new constitutionalism for caring institutions specifically, and for what feminists call social reproduction more generally: the biological reproduction of the species; the reproduction of labor power; and the reproduction of social institutions and processes associated with the creation and maintenance of communities. New constitutional governance frameworks fundamentally reshape conditions under which the care of human beings takes place. Caring institutions once governed by enabling professions geared to universal care are now determined increasingly by market values and private forces, and driven directly by the profit motive. This is one of the reasons why neo-liberalism is increasingly contested in both the North and the global South. PMID:16532302

  1. New constitutionalism and the social reproduction of caring institutions.

    PubMed

    Gill, Stephen; Bakker, Isabella

    2006-01-01

    This essay analyzes neo-liberal economic agreements and legal and political frameworks or what has been called the "new constitutionalism," a governance framework that empowers market forces to reshape economic and social development worldwide. The article highlights some consequences of new constitutionalism for caring institutions specifically, and for what feminists call social reproduction more generally: the biological reproduction of the species; the reproduction of labor power; and the reproduction of social institutions and processes associated with the creation and maintenance of communities. New constitutional governance frameworks fundamentally reshape conditions under which the care of human beings takes place. Caring institutions once governed by enabling professions geared to universal care are now determined increasingly by market values and private forces, and driven directly by the profit motive. This is one of the reasons why neo-liberalism is increasingly contested in both the North and the global South.

  2. Status of Fundamental Physics Program

    NASA Technical Reports Server (NTRS)

    Lee, Mark C.

    2003-01-01

    Update of the Fundamental Physics Program. JEM/EF Slip. 2 years delay. Reduced budget. Community support and advocacy led by Professor Nick Bigelow. Reprogramming led by Fred O Callaghan/JPL team. LTMPF M1 mission (DYNAMX and SUMO). PARCS. Carrier re baselined on JEM/EF.

  3. Fundamental Practices of Curriculum Development.

    ERIC Educational Resources Information Center

    Usova, George M.; Gibson, Marcia

    Designed to give guidance to those involved in the curriculum development process within the Shipyard Training Modernization Program (STMP), this guide provides an understanding of the fundamental practices followed in the curriculum development process. It also demonstrates incorrect and correct approaches to the development of the curriculum…

  4. Light as a Fundamental Particle

    ERIC Educational Resources Information Center

    Weinberg, Steven

    1975-01-01

    Presents two arguments concerning the role of the photon. One states that the photon is just another particle distinguished by a particular value of charge, spin, mass, lifetime, and interaction properties. The second states that the photon plays a fundamental role with a deep relation to ultimate formulas of physics. (GS)

  5. Fundamentals of Microelectronics Processing (VLSI).

    ERIC Educational Resources Information Center

    Takoudis, Christos G.

    1987-01-01

    Describes a 15-week course in the fundamentals of microelectronics processing in chemical engineering, which emphasizes the use of very large scale integration (VLSI). Provides a listing of the topics covered in the course outline, along with a sample of some of the final projects done by students. (TW)

  6. Fundamentals of the Slide Library.

    ERIC Educational Resources Information Center

    Boerner, Susan Zee

    This paper is an introduction to the fundamentals of the art (including architecture) slide library, with some emphasis on basic procedures of the science slide library. Information in this paper is particularly relevant to the college, university, and museum slide library. Topics addressed include: (1) history of the slide library; (2) duties of…

  7. Chronometric cosmology and fundamental fermions

    PubMed Central

    Segal, I. E.

    1982-01-01

    It is proposed that the fundamental fermions of nature are modeled by fields on the chronometric cosmos that are not precisely spinors but become such only in the nonchronometric limit. The imbedding of the scale-extended Poincaré group in the linearizer of the Minkowskian conformal group defines such fields, by induction. PMID:16593266

  8. Museum Techniques in Fundamental Education.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    Some museum techniques and methods can be used in fundamental educational programs without elaborate buildings or equipment; exhibitions should be based on valid presumptions and should take into account the "common sense" beliefs of people for whom the exhibit is designed. They can be used profitably in the economic development of local cultural…

  9. Brake Fundamentals. Automotive Articulation Project.

    ERIC Educational Resources Information Center

    Cunningham, Larry; And Others

    Designed for secondary and postsecondary auto mechanics programs, this curriculum guide contains learning exercises in seven areas: (1) brake fundamentals; (2) brake lines, fluid, and hoses; (3) drum brakes; (4) disc brake system and service; (5) master cylinder, power boost, and control valves; (6) parking brakes; and (7) trouble shooting. Each…

  10. Fundamentals of Welding. Teacher Edition.

    ERIC Educational Resources Information Center

    Fortney, Clarence; And Others

    These instructional materials assist teachers in improving instruction on the fundamentals of welding. The following introductory information is included: use of this publication; competency profile; instructional/task analysis; related academic and workplace skills list; tools, materials, and equipment list; and 27 references. Seven units of…

  11. Environmental Law: Fundamentals for Schools.

    ERIC Educational Resources Information Center

    Day, David R.

    This booklet outlines the environmental problems most likely to arise in schools. An overview provides a fundamental analysis of environmental issues rather than comprehensive analysis and advice. The text examines the concerns that surround superfund cleanups, focusing on the legal framework, and furnishes some practical pointers, such as what to…

  12. Fundamentals of Environmental Education. Report.

    ERIC Educational Resources Information Center

    1976

    An outline of fundamental definitions, relationships, and human responsibilities related to environment provides a basis from which a variety of materials, programs, and activities can be developed. The outline can be used in elementary, secondary, higher education, or adult education programs. The framework is based on principles of the science…

  13. Franchising Reproductive Health Services

    PubMed Central

    Stephenson, Rob; Tsui, Amy Ong; Sulzbach, Sara; Bardsley, Phil; Bekele, Getachew; Giday, Tilahun; Ahmed, Rehana; Gopalkrishnan, Gopi; Feyesitan, Bamikale

    2004-01-01

    Objectives Networks of franchised health establishments, providing a standardized set of services, are being implemented in developing countries. This article examines associations between franchise membership and family planning and reproductive health outcomes for both the member provider and the client. Methods Regression models are fitted examining associations between franchise membership and family planning and reproductive health outcomes at the service provider and client levels in three settings. Results Franchising has a positive association with both general and family planning client volumes, and the number of family planning brands available. Similar associations with franchise membership are not found for reproductive health service outcomes. In some settings, client satisfaction is higher at franchised than other types of health establishments, although the association between franchise membership and client outcomes varies across the settings. Conclusions Franchise membership has apparent benefits for both the provider and the client, providing an opportunity to expand access to reproductive health services, although greater attention is needed to shift the focus from family planning to a broader reproductive health context. PMID:15544644

  14. Adipokines in human reproduction.

    PubMed

    Dupont, Joëlle; Pollet-Villard, Xavier; Reverchon, Maxime; Mellouk, Namya; Levy, Rachel

    2015-10-01

    Adipose tissue communicates with other central and peripheral organs by the synthesis and release of substances called adipokines. The most studied adipokine is leptin but others have been recently identified including resistin, adiponectin, chemerin, omentin and visfatin. These adipokines have a critical role in the development of obesity-related complications and inflammatory conditions. However, they are also involved in other functions in the organism including reproductive functions. Indeed, many groups have demonstrated that adipokine receptors, such as adiponectin and chemerin, but also adipokines themselves (adiponectin, chemerin, resistin, visfatin and omentin) are expressed in human peripheral reproductive tissues and that these adipokines are likely to exert direct effects on these tissues. After a brief description of these new adipokines, an overview of their actions in different human reproductive organs (hypothalamus, pituitary, ovary, testis, uterus and placenta) will be presented. Finally, comments will be made on the eventual alterations of these adipokines in reproductive disorders, with special attention to polycystic ovary syndrome, a disease characterized by dysfunction of gonadal axis and systemic nerve endocrine metabolic network with a prevalence of up to 10% in women of reproductive age.

  15. Melatonin and male reproduction.

    PubMed

    Li, Chunjin; Zhou, Xu

    2015-06-15

    Melatonin is a neurohormone secreted by the pineal gland whose concentrations in the body are regulated by both the dark-light and seasonal cycles. The reproductive function of seasonal breeding animals is clearly influenced by the circadian variation in melatonin levels. Moreover, a growing body of evidence indicates that melatonin has important effects in the reproduction of some non-seasonal breeding animals. In males, melatonin affects reproductive regulation in three main ways. First, it regulates the secretion of two key neurohormones, GnRH and LH. Second, it regulates testosterone synthesis and testicular maturation. Third, as a potent free radical scavenger that is both lipophilic and hydrophilic, it prevents testicular damage caused by environmental toxins or inflammation. This review summarizes the existing data on the possible biological roles of melatonin in male reproduction. Overall, the literature data indicate that melatonin affects the secretion of both gonadotropins and testosterone while also improving sperm quality. This implies that it has important effects on the regulation of testicular development and male reproduction.

  16. Speeding the reproductive revolution.

    PubMed

    Robey, B; Upadhyay, U

    1999-01-01

    In 1994, at the International Conference on Population and Development (ICPD) held in Cairo, the international community set the goal of ensuring universal access to reproductive health care by 2015 and agreed to finance its costs. Few governments and donor countries, however, have made good on commitments made at the ICPD. Reproductive health is not improving and may actually be getting worse. Specific goals to be reached by 2015 include meeting all unmet need for family planning, reducing maternal mortality by 75% compared with 1990 levels, and reducing infant mortality to lower than 35 deaths/1000 births. Reaching these and the related reproductive health goals of the ICPD was calculated to cost about US$17 billion/year until 2000, then to increase to $22 billion/year by 2015 (in constant 1993 US dollars). Developing countries agreed to pay 66% of the cost, while donor countries paid the remainder. Immediately after the ICPD, reproductive health funding increased substantially, then declined again, with most donor countries failing to meet their funding commitments. Failure to deliver on the promised financial support for the ICPD goals will result in higher levels of unintended pregnancies, induced abortions, cases of maternal mortality, and infant deaths. Governments need to be convinced that paying for reproductive health programs is an urgent priority and that developing countries, donor countries, and multilateral institutions all have much to gain from reaching the ICPD goals. PMID:12322000

  17. Biofluidmechanics of Reproduction

    NASA Astrophysics Data System (ADS)

    Fauci, Lisa J.; Dillon, Robert

    2006-01-01

    Mammalian fertilization requires the coordinated activity of motile spermatozoa, muscular contractions of the uterus and oviduct, as well as ciliary beating. These elastic structures generate forces that drive fluid motion, but their configurations are, in turn, determined by the fluid dynamics. We review the basic fluid mechanical aspects of reproduction, including flagellar/ciliary beating and peristalsis. We report on recent biological studies that have shed light on the relative importance of the mechanical ingredients of reproduction. In particular, we examine sperm motility in the reproductive tract, ovum pickup and transport in the oviduct, as well as sperm-egg interactions. We review recent advances in understanding the internal mechanics of cilia and flagella, flagellar surface interaction, sperm motility in complex fluids, and the role of fluid dynamics in embryo transfer. We outline promising computational fluid dynamics frameworks that may be used to investigate these complex, fluid-structure interactions.

  18. Biotechnology in reproductive medicine.

    PubMed

    Illmensee, Karl

    2002-01-01

    In this review I am summarizing the past and current progress in the field of pharmaceutical, diagnostic, therapeutic, and reproductive cloning in mammals. Several human gene products can be pharmaceutically explored in transgenic farm animals and employed for medical applications. Preimplantation genetic diagnosis (PGD) is utilizing modern molecular cloning techniques to detect genetic and chromosomal aberrations in early embryos originating from patients with inborn errors at risk for hereditary diseases or age-related risk for abnormal karyotype. Stem cell engineering from early human embryos is creating new and promising but also controversial applications for therapeutic and regenerative medicine. Potential risk factors for reproductive cloning are presented and discussed in the context of possible developmental malformations, frequently observed after embryo culture and cloning in farm animals. Future extension of biotechnology to human reproductive cloning is currently under worldwide dispute.

  19. Human reproduction: Jewish perspectives.

    PubMed

    Schenker, Joseph G

    2013-11-01

    Developments in science and technology and corresponding clinical applications raise new religious questions, often without clear answers. The role of theology in bioethics is integral to clarify perceived attitudes toward these developments for different religious communities. The Jewish attitude towards procreation is derived from the first commandment of God to Adam to 'Be fruitful and multiply'. Judaism allows the practice of all techniques of assisted reproduction when the oocyte and spermatozoon originate from the wife and husband respectively. This paper presents the attitude of Jewish Law -- Halacha to therapeutic procedures, such as IVF-embryo transfer, spermatozoa, oocytes, embryo donation, cryopreservation of genetic material, surrogacy, posthumous reproduction, gender preselection, reproductive and therapeutic cloning. PMID:24000935

  20. [Reproduction of beef cattle].

    PubMed

    de Kruif, A; Mijten, P; Van den Branden, J; Opsomer, G

    1992-03-01

    The literature on the reproduction of beef cattle is reviewed in the present paper. To begin with the differences between dairy and beef cattle are elucidated. Secondly, the most important reproductive problems of beef cows are discussed. Items discussed include: the arrival of puberty, the interval between parturition and the first service and infertility. In Belgium, where nearly all beef cows belong to the double muscled White and Blue breed and have to be delivered by caesarean sections, many fertility problems are due to adhesions between the uterus and the surrounding tissues. Besides the quality of the semen of many of the bulls used is rather poor. This is probably caused by the extreme selection for beef production. Finally, the criteria which should be used to determine the reproductive efficiency of beef cows are discussed. Such as the percentage of pregnant cows, the proportion of live and weaned calves and the calving interval. PMID:1542865

  1. Introduction: Communicating Reproduction.

    PubMed

    Hopwood, Nick; Jones, Peter Murray; Kassell, Lauren; Secord, Jim

    2015-01-01

    Communication should be central to histories of reproduction, because it has structured how people do and do not reproduce. Yet communication has been so pervasive, and so various, that it is often taken for granted and the historical specificities overlooked. Making communication a frame for histories of reproduction can draw a fragmented field together, including by putting the promotion of esoteric ideas on a par with other practical activities. Paying communication close attention can revitalize the history of reproduction over the long term by highlighting continuities as well as the complex connections between new technologies and new approaches. Themes such as the power of storytelling, the claiming and challenging of expertise, and relations between knowledge and ignorance, secrecy and propriety also invite further study. PMID:26521666

  2. Introduction: Communicating Reproduction.

    PubMed

    Hopwood, Nick; Jones, Peter Murray; Kassell, Lauren; Secord, Jim

    2015-01-01

    Communication should be central to histories of reproduction, because it has structured how people do and do not reproduce. Yet communication has been so pervasive, and so various, that it is often taken for granted and the historical specificities overlooked. Making communication a frame for histories of reproduction can draw a fragmented field together, including by putting the promotion of esoteric ideas on a par with other practical activities. Paying communication close attention can revitalize the history of reproduction over the long term by highlighting continuities as well as the complex connections between new technologies and new approaches. Themes such as the power of storytelling, the claiming and challenging of expertise, and relations between knowledge and ignorance, secrecy and propriety also invite further study.

  3. Dinosaur Reproduction and Parenting

    NASA Astrophysics Data System (ADS)

    Horner, John R.

    Non-avian dinosaur reproductive and parenting behaviors were mostly similar to those of extant archosaurs. Non-avian dinosaurs were probably sexually dimorphic and some may have engaged in hierarchical rituals. Non-avian coelurosaurs (e.g. Troodontidae, Oviraptorosauria) had two active oviducts, each of which produced single eggs on a daily or greater time scale. The eggs of non-coelurosaurian dinosaurs (e.g. Ornithischia, Sauropoda) were incubated in soils, whereas the eggs of non-avian coelurosaurs (e.g. Troodon, Oviraptor) were incubated with a combination of soil and direct parental contact. Parental attention to the young was variable, ranging from protection from predators to possible parental feeding of nest-bound hatchlings. Semi-altricial hadrosaur hatchlings exited their respective nests near the time of their first linear doubling. Some reproductive behaviors, once thought exclusive to Aves, arose first in non-avian dinosaurs. The success of the Dinosauria may be related to reproductive strategies.

  4. Tribbles role in reproduction.

    PubMed

    Basatvat, Shaghayegh; Carter, Deborah Angela Louise; Kiss-Toth, Endre; Fazeli, Alireza

    2015-10-01

    Tribbles (TRIB) proteins, a family of evolutionary conserved psuedokinase proteins, modulate various signalling pathways within the cell. The regulatory roles of TRIB make them an important part of a number of biological processes ranging from cell proliferation to metabolism, immunity, inflammation and carcinogenesis. Innate immune system plays a pivotal role during the regulation of reproductive processes that allows successful creation of an offspring. Its involvement initiates from fertilization of the oocyte by spermatozoon and lasts throughout early embryonic development, pregnancy and labour. Therefore, there is a close cooperation between the reproductive system and the innate immune system. Evidence from our lab has demonstrated that improper activation of the innate immune system can reduce embryo implantation, thus leading to infertility. Therefore, control mechanisms regulating the innate immune system function can be critical for successful reproductive events.

  5. Feminism and reproductive technologies.

    PubMed

    Callahan, Joan C

    1994-01-01

    ... Rowland is a social scientist and a radical feminist, and she has undertaken the task of making readers think twice about reproductive technologies. If a reader isn't thinking twice, it will not do to blame it on Rowland and the shortcomings of her book. She has a good deal to say that is extremely important and that needs to be considered by anyone who is interested in the moral issues, in general, and the issues for women and children, in particular, that are raised by the new and emerging reproductive technologies. Her book should be widely read. And it should generate the worries it is written to generate. PMID:11644539

  6. Fundamental neutron physics at LANSCE

    SciTech Connect

    Greene, G.

    1995-10-01

    Modern neutron sources and science share a common origin in mid-20th-century scientific investigations concerned with the study of the fundamental interactions between elementary particles. Since the time of that common origin, neutron science and the study of elementary particles have evolved into quite disparate disciplines. The neutron became recognized as a powerful tool for studying condensed matter with modern neutron sources being primarily used (and justified) as tools for neutron scattering and materials science research. The study of elementary particles has, of course, led to the development of rather different tools and is now dominated by activities performed at extremely high energies. Notwithstanding this trend, the study of fundamental interactions using neutrons has continued and remains a vigorous activity at many contemporary neutron sources. This research, like neutron scattering research, has benefited enormously by the development of modern high-flux neutron facilities. Future sources, particularly high-power spallation sources, offer exciting possibilities for continuing this research.

  7. DOE Fundamentals Handbook: Classical Physics

    SciTech Connect

    Not Available

    1992-06-01

    The Classical Physics Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of physical forces and their properties. The handbook includes information on the units used to measure physical properties; vectors, and how they are used to show the net effect of various forces; Newton's Laws of motion, and how to use these laws in force and motion applications; and the concepts of energy, work, and power, and how to measure and calculate the energy involved in various applications. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility systems and equipment.

  8. Variation of fundamental constants: theory

    NASA Astrophysics Data System (ADS)

    Flambaum, Victor

    2008-05-01

    Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. There are some hints for the variation of different fundamental constants in quasar absorption spectra and Big Bang nucleosynthesis data. A large number of publications (including atomic clocks) report limits on the variations. We want to study the variation of the main dimensionless parameters of the Standard Model: 1. Fine structure constant alpha (combination of speed of light, electron charge and Plank constant). 2. Ratio of the strong interaction scale (LambdaQCD) to a fundamental mass like electron mass or quark mass which are proportional to Higgs vacuum expectation value. The proton mass is propotional to LambdaQCD, therefore, the proton-to-electron mass ratio comes into this second category. We performed necessary atomic, nuclear and QCD calculations needed to study variation of the fundamental constants using the Big Bang Nucleosynthsis, quasar spectra, Oklo natural nuclear reactor and atomic clock data. The relative effects of the variation may be enhanced in transitions between narrow close levels in atoms, molecules and nuclei. If one will study an enhanced effect, the relative value of systematic effects (which are not enhanced) may be much smaller. Note also that the absolute magnitude of the variation effects in nuclei (e.g. in very narrow 7 eV transition in 229Th) may be 5 orders of magnitude larger than in atoms. A different possibility of enhancement comes from the inversion transitions in molecules where splitting between the levels is due to the quantum tunneling amplitude which has strong, exponential dependence on the electron to proton mass ratio. Our study of NH3 quasar spectra has already given the best limit on the variation of electron to proton mass ratio.

  9. Male Reproductive Toxicology: Environmental Exposures vs Reproductive Competence

    EPA Science Inventory

    Like the lecture this chapter begins with an overview of male reproductive biology and transitions into male reproductive toxicology. It ends with a brief discussion of the strengths and weaknesses in male reproductive toxicology and epidemiology today. This chapter is highly il...

  10. Reproduction in domestic buffalo.

    PubMed

    Perera, B M A O

    2008-07-01

    The domestic buffalo is an indispensable livestock resource to millions of smallholder farmers in developing countries, particularly in Asia. Although its reproductive biology is basically similar to that of cattle, there are important differences and unique characteristics that need to be considered in order to apply modern reproductive technologies to improve its productivity. Under most smallholder production systems, the reproductive efficiency of buffalo is compromised by factors related to climate, management, nutrition and diseases. However, when managed and fed properly, buffalo can have good fertility and provide milk, calves and draught power over a long productive life. The basic technical problems associated with artificial insemination in buffalo were largely overcome two decades ago, but the technology has not had the expected impact in some developing countries, because largely of infrastructural and logistic problems. Approaches involving the use of hormones for treating anoestrus and for synchronizing oestrus have had varying rates of success, depending on the protocols used and the incidence of underlying problems that cause infertility. Embryo technologies such as multiple ovulation embryo transfer, in vitro embryo production, cryopreservation and cloning are being intensively studied but have had far lower success rates than in cattle. Improving the productivity of buffalo requires an understanding of their potential and limitations under each farming system, development of simple intervention strategies to ameliorate deficiencies in management, nutrition and healthcare, followed by judicious application of reproductive technologies that are sustainable with the resources available to buffalo farmers.

  11. Female Reproductive System.

    ERIC Educational Resources Information Center

    Hodge, N. J.

    This autoinstructional lesson can be used with health education and/or biology classes in a high school curriculum. It deals with the study of human development with emphasis on the female reproductive organs and cycles. The behavioral objectives are given, and the materials and equipment needed to gain these objectives are itemized. Fifteen…

  12. Melatonin and female reproduction.

    PubMed

    Tamura, Hiroshi; Takasaki, Akihisa; Taketani, Toshiaki; Tanabe, Manabu; Lee, Lifa; Tamura, Isao; Maekawa, Ryo; Aasada, Hiromi; Yamagata, Yoshiaki; Sugino, Norihiro

    2014-01-01

    Melatonin (N-acetyl-5-methoxytryptamine) is secreted during the dark hours at night by the pineal gland. After entering the circulation, melatonin acts as an endocrine factor and a chemical messenger of light and darkness. It regulates a variety of important central and peripheral actions related to circadian rhythms and reproduction. It also affects the brain, immune, gastrointestinal, cardiovascular, renal, bone and endocrine functions and acts as an oncostatic and anti-aging molecule. Many of melatonin's actions are mediated through interactions with specific membrane-bound receptors expressed not only in the central nervous system, but also in peripheral tissues. Melatonin also acts through non-receptor-mediated mechanisms, for example serving as a scavenger for reactive oxygen species and reactive nitrogen species. At both physiological and pharmacological concentrations, melatonin attenuates and counteracts oxidative stress and regulates cellular metabolism. Growing scientific evidence of reproductive physiology supports the role of melatonin in human reproduction. This review was conducted to investigate the effects of melatonin on female reproduction and to summarize our findings in this field.

  13. Male Reproductive System.

    ERIC Educational Resources Information Center

    Turkington, B. A.

    This autoinstructional lesson deals with the study of the human body with emphasis on the life process of reproduction. It is a learning activity included in high school biology or health education classes. The behavioral objectives are listed and the equipment and materials needed to help the student gain these objectives are also included in the…

  14. Drug abuse and reproduction.

    PubMed

    Smith, C G; Asch, R H

    1987-09-01

    It is clear that a number of CNS agents, including drugs of abuse, can inhibit reproductive function. Figure 1 shows the chemical diversity of some of the drug groups that affect reproductive hormones. Their structural dissimilarity to the steroid hormones is also readily apparent in the figure. These chemically diverse drugs share an important pharmacologic property: they are highly potent neuroactive drugs, and they can disrupt hypothalamic-pituitary function. Although it is frequently difficult to distinguish between direct drug actions on the hypothalamic-pituitary axis and subsequent effects on gonadal hormones and sex accessory gland function, the distinction is an important one. Most neuroactive drugs produce only transient effects on the central nervous pathways necessary for normal gonadotropin secretion. The disruptive effects of these drugs are likely to be transient and completely reversible, and tolerance to the inhibitory drug effects may occur even with continued drug use. Under these circumstances, normal adults may experience only subtle changes in sexual function. However, individuals with compromised reproductive function may exhibit major problems. It is also likely that adolescents may be at substantial risk for reproductive damage from these neuroactive drugs since the endocrine events associated with puberty are dependent on the normal development of the hypothalamic-pituitary axis.

  15. Ethics of Reproductive Engineering

    ERIC Educational Resources Information Center

    Buuck, R. John

    1977-01-01

    Artificial insemination, in vitro fertilization, artificial placentas, and cloning are examined from a ethical viewpoint. The moral, social, and legal implications of reproductive engineering are considered important to biology as well as medicine. The author suggests that these ethical issues should be included in the biology curriculum and lists…

  16. Reproduction in domestic buffalo.

    PubMed

    Perera, B M A O

    2008-07-01

    The domestic buffalo is an indispensable livestock resource to millions of smallholder farmers in developing countries, particularly in Asia. Although its reproductive biology is basically similar to that of cattle, there are important differences and unique characteristics that need to be considered in order to apply modern reproductive technologies to improve its productivity. Under most smallholder production systems, the reproductive efficiency of buffalo is compromised by factors related to climate, management, nutrition and diseases. However, when managed and fed properly, buffalo can have good fertility and provide milk, calves and draught power over a long productive life. The basic technical problems associated with artificial insemination in buffalo were largely overcome two decades ago, but the technology has not had the expected impact in some developing countries, because largely of infrastructural and logistic problems. Approaches involving the use of hormones for treating anoestrus and for synchronizing oestrus have had varying rates of success, depending on the protocols used and the incidence of underlying problems that cause infertility. Embryo technologies such as multiple ovulation embryo transfer, in vitro embryo production, cryopreservation and cloning are being intensively studied but have had far lower success rates than in cattle. Improving the productivity of buffalo requires an understanding of their potential and limitations under each farming system, development of simple intervention strategies to ameliorate deficiencies in management, nutrition and healthcare, followed by judicious application of reproductive technologies that are sustainable with the resources available to buffalo farmers. PMID:18638124

  17. Preparing for Assisted Reproductive Technology

    MedlinePlus

    ... CDC Cancel Submit Search The CDC Assisted Reproductive Technology (ART) Note: Javascript is disabled or is not ... visit this page: About CDC.gov . Assisted Reproductive Technology (ART) What Is ART Patient Resources Preparing for ...

  18. Fundamental Limits to Cellular Sensing

    NASA Astrophysics Data System (ADS)

    ten Wolde, Pieter Rein; Becker, Nils B.; Ouldridge, Thomas E.; Mugler, Andrew

    2016-03-01

    In recent years experiments have demonstrated that living cells can measure low chemical concentrations with high precision, and much progress has been made in understanding what sets the fundamental limit to the precision of chemical sensing. Chemical concentration measurements start with the binding of ligand molecules to receptor proteins, which is an inherently noisy process, especially at low concentrations. The signaling networks that transmit the information on the ligand concentration from the receptors into the cell have to filter this receptor input noise as much as possible. These networks, however, are also intrinsically stochastic in nature, which means that they will also add noise to the transmitted signal. In this review, we will first discuss how the diffusive transport and binding of ligand to the receptor sets the receptor correlation time, which is the timescale over which fluctuations in the state of the receptor, arising from the stochastic receptor-ligand binding, decay. We then describe how downstream signaling pathways integrate these receptor-state fluctuations, and how the number of receptors, the receptor correlation time, and the effective integration time set by the downstream network, together impose a fundamental limit on the precision of sensing. We then discuss how cells can remove the receptor input noise while simultaneously suppressing the intrinsic noise in the signaling network. We describe why this mechanism of time integration requires three classes (groups) of resources—receptors and their integration time, readout molecules, energy—and how each resource class sets a fundamental sensing limit. We also briefly discuss the scheme of maximum-likelihood estimation, the role of receptor cooperativity, and how cellular copy protocols differ from canonical copy protocols typically considered in the computational literature, explaining why cellular sensing systems can never reach the Landauer limit on the optimal trade

  19. Frontiers of Fundamental Physics 14

    NASA Astrophysics Data System (ADS)

    The 14th annual international symposium "Frontiers of Fundamental Physics" (FFP14) was organized by the OCEVU Labex. It was held in Marseille, on the Saint-Charles Campus of Aix Marseille University (AMU) and had over 280 participants coming from all over the world. FFP Symposium began in India in 1997 and it became itinerant in 2004, through Europe, Canada and Australia. It covers topics in fundamental physics with the objective to enable scholars working in related areas to meet on a single platform and exchange ideas. In addition to highlighting the progress in these areas, the symposium invites the top researchers to reflect on the educational aspects of our discipline. Moreover, the scientific concepts are also discussed through philosophical and epistemological viewpoints. Several eminent scientists, such as the laureates of prestigious awards (Nobel Prize, Fields Medal,…), have already participated in these meetings. The FFP14 Symposium developed around seven main themes, namely: Astroparticle Physics, Cosmology, High Energy Physics, Quantum Gravity, Mathematical Physics, Physics Education, Epistemology and Philosophy. The morning was devoted to the plenary session, with talks for a broad audience of physicists in its first half (9:00-10:30), and more specialized in its second half (11:00-12:30); this part was held in three amphitheaters. The parallel session of the Symposium took place during the afternoon (14:30-18:30) with seven thematic conferences and an additional conference on open topics named "Frontiers of Fundamental Physics". These eight conferences were organized around the contributions of participants, in addition to the ones of invited speakers. Altogether, there were some 250 contributions to the symposium (talks and posters). The plenary talks were webcasted live and recorded. The slides of the talks and the videos of the plenary talks are available from the Symposium web site: http://ffp14.cpt.univ-mrs.fr/

  20. Solid Lubrication Fundamentals and Applications

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    2001-01-01

    Solid Lubrication Fundamentals and Applications description of the adhesion, friction, abrasion, and wear behavior of solid film lubricants and related tribological materials, including diamond and diamond-like solid films. The book details the properties of solid surfaces, clean surfaces, and contaminated surfaces as well as discussing the structures and mechanical properties of natural and synthetic diamonds; chemical-vapor-deposited diamond film; surface design and engineering toward wear-resistant, self-lubricating diamond films and coatings. The author provides selection and design criteria as well as applications for synthetic and natural coatings in the commercial, industrial and aerospace industries..

  1. Reconstruction of fundamental SUSY parameters

    SciTech Connect

    P. M. Zerwas et al.

    2003-09-25

    We summarize methods and expected accuracies in determining the basic low-energy SUSY parameters from experiments at future e{sup +}e{sup -} linear colliders in the TeV energy range, combined with results from LHC. In a second step we demonstrate how, based on this set of parameters, the fundamental supersymmetric theory can be reconstructed at high scales near the grand unification or Planck scale. These analyses have been carried out for minimal supergravity [confronted with GMSB for comparison], and for a string effective theory.

  2. Reproductive conflict and the separation of reproductive generations in humans

    PubMed Central

    Cant, Michael A.; Johnstone, Rufus A.

    2008-01-01

    An enduring puzzle of human life history is why women cease reproduction midway through life. Selection can favor postreproductive survival because older females can help their offspring to reproduce. But the kin-selected fitness gains of helping appear insufficient to outweigh the potential benefits of continued reproduction. Why then do women cease reproduction in the first place? Here, we suggest that early reproductive cessation in humans is the outcome of reproductive competition between generations, and we present a simple candidate model of how this competition will be resolved. We show that among primates exhibiting a postreproductive life span, humans exhibit an extraordinarily low degree of reproductive overlap between generations. The rapid senescence of the human female reproductive system coincides with the age at which, in natural fertility populations, women are expected to encounter reproductive competition from breeding females of the next generation. Several lines of evidence suggest that in ancestral hominids, this younger generation typically comprised immigrant females. In these circumstances, relatedness asymmetries within families are predicted to give younger females a decisive advantage in reproductive conflict with older females. A model incorporating both the costs of reproductive competition and the benefits of grandmothering can account for the timing of reproductive cessation in humans and so offers an improved understanding of the evolution of menopause. PMID:18378891

  3. Reproductive rights approach to reproductive health in developing countries

    PubMed Central

    Pillai, Vijayan K.; Gupta, Rashmi

    2011-01-01

    Background Research on reproductive health in developing countries focuses mostly on the role of economic development on various components of reproductive health. Cross-sectional and empirical research studies in particular on the effects of non-economic factors such as reproductive rights remain few and far between. Objective This study investigates the influence of two components of an empowerment strategy, gender equality, and reproductive rights on women's reproductive health in developing countries. The empowerment strategy for improving reproductive health is theoretically situated on a number of background factors such as economic and social development. Design Cross-national socioeconomic and demographic data from a number of international organizations on 142 developing countries are used to test a model of reproductive rights and reproductive health. Results The findings suggest that both economic and democratic development have significant positive effects on levels of gender equality. The level of social development plays a prominent role in promoting reproductive rights. It is found that reproductive rights channel the influences of social structural factors and gender equality on reproductive health. PMID:22184501

  4. Triennial Reproduction Symposium: 2012 Casida Award recipient: philosophy for graduate education in reproductive physiology and endocrinology.

    PubMed

    Randel, R D

    2013-07-01

    The purpose of graduate education in reproductive physiology and endocrinology is to develop scientists and educators who will create new knowledge and impart this knowledge to appropriate end users in animal agriculture. Technology changes over time but the scientific method remains constant. Society needs scientists and educators who are grounded in the fundamentals of biology as well as in animal agriculture. Students in reproductive physiology and endocrinology require a blending of fundamental sciences with application to agricultural species in their training. My philosophy has been to treat each student as a unique individual needing a program designed to eliminate weaknesses and to magnify strengths. Each student must have a background in statistics and biochemistry. These 2 fundamental areas of science are of such importance that they must be included early in the educational process to assure competence in research or teaching. Students must be involved in their own research as early as possible. Collaborative and interdisciplinary research has been a key factor in developing successful scientists and educators in my graduate education program. Success of students after graduation has been a rewarding aspect of training graduate students.

  5. Reproductive ageing in women.

    PubMed

    Djahanbakhch, O; Ezzati, M; Zosmer, A

    2007-01-01

    The traditional view in respect to female reproduction is that the number of oocytes at birth is fixed and continuously declines towards the point when no more oocytes are available after menopause. In this review we briefly discuss the embryonic development of female germ cells and ovarian follicles. The ontogeny of the hypothalamic-pituitary-gonadal axis is then discussed, with a focus on pubertal transition and normal ovulatory menstrual cycles during female adult life. Biochemical markers of menopausal transition are briefly examined. We also examine the effects of age on female fertility, the contribution of chromosomal abnormalities of the oocyte to the observed decline in female fertility with age and the possible biological basis for the occurrence of such abnormalities. Finally, we consider the effects of maternal age on obstetric complications and perinatal outcome. New data that have the potential to revolutionize our understanding of mammalian oogenesis and follicular formation, and of the female reproductive ageing process, are also briefly considered.

  6. Ghrelin and reproductive disorders.

    PubMed

    Repaci, Andrea; Gambineri, Alessandra; Pagotto, Uberto; Pasquali, Renato

    2011-06-20

    Ghrelin is an important factor involved in most of the metabolic and hormonal signals which adapt the reproductive functions in conditions of altered energy balance. Moreover, the coordinated role of leptin and ghrelin appears in fact to have a specific role in the regulation of puberty. Systemic action of ghrelin on the reproductive axis involves the control of the hypothalamic-pituitary-gondal axis. In addition, it has been shown that ghrelin may directly act at a gonadal level in both females and males. Available data also demonstrate that sex steroid hormones and gonadotropins may in turn regulate the gonadal effect of ghrelin, as documented by studies performed in females with the polycystic ovary syndrome and in hypogonadal men. Notably, recent studies also confirm a potentially important role for ghrelin in fetal and neonatal energy balance, and specifically in allowing fetal adaptation to an adverse intrauterine environment.

  7. Whither Artificial Reproduction?

    PubMed Central

    Percival-Smith, Robin

    1985-01-01

    Artificial reproduction now offers sub fertile couples a number of options which raise scientific and ethical questions. This article discusses the Canadian and British experiences in formulating regulations and legislation in this important field. Current work on mammalian embryo research foretells the direction which human research will take. This article stresses the need for family physicians' participation in the ethical decisions that accompany these new developments. PMID:21274181

  8. Interventions in reproduction.

    PubMed

    Sheriff, D S; Sheriff, S Omer

    2006-01-01

    Assisted reproductive technology has helped many childless couples. It has also raised questions about how appropriate the technology might be in different situations. How we understand parenthood is crucial in taking a stand on such scientific intervention. It is suggested that physicians should decide on offering artificial insemination, surrogacy and in-vitro fertilisation only after considering if the child will have good parents and if there will be legal complications from the use of the technology. PMID:17223683

  9. Mitochondria and mammalian reproduction.

    PubMed

    Ramalho-Santos, João; Amaral, Sandra

    2013-10-15

    Mitochondria are cellular organelles with crucial roles in ATP synthesis, metabolic integration, reactive oxygen species (ROS) synthesis and management, the regulation of apoptosis (namely via the intrinsic pathway), among many others. Additionally, mitochondria in different organs or cell types may have distinct properties that can decisively influence functional analysis. In terms of the importance of mitochondria in mammalian reproduction, and although there are species-specific differences, these aspects involve both energetic considerations for gametogenesis and fertilization, control of apoptosis to ensure the proper production of viable gametes, and ROS signaling, as well as other emerging aspects. Crucially, mitochondria are the starting point for steroid hormone biosynthesis, given that the conversion of cholesterol to pregnenolone (a common precursor for all steroid hormones) takes place via the activity of the cytochrome P450 side-chain cleavage enzyme (P450scc) on the inner mitochondrial membrane. Furthermore, mitochondrial activity in reproduction has to be considered in accordance with the very distinct strategies for gamete production in the male and female. These include distinct gonad morpho-physiologies, different types of steroids that are more prevalent (testosterone, estrogens, progesterone), and, importantly, the very particular timings of gametogenesis. While spermatogenesis is complete and continuous since puberty, producing a seemingly inexhaustible pool of gametes in a fixed environment; oogenesis involves the episodic production of very few gametes in an environment that changes cyclically. These aspects have always to be taken into account when considering the roles of any common element in mammalian reproduction.

  10. Clonal reproduction in fungi.

    PubMed

    Taylor, John W; Hann-Soden, Christopher; Branco, Sara; Sylvain, Iman; Ellison, Christopher E

    2015-07-21

    Research over the past two decades shows that both recombination and clonality are likely to contribute to the reproduction of all fungi. This view of fungi is different from the historical and still commonly held view that a large fraction of fungi are exclusively clonal and that some fungi have been exclusively clonal for hundreds of millions of years. Here, we first will consider how these two historical views have changed. Then we will examine the impact on fungal research of the concept of restrained recombination [Tibayrenc M, Ayala FJ (2012) Proc Natl Acad Sci USA 109 (48):E3305-E3313]. Using animal and human pathogenic fungi, we examine extrinsic restraints on recombination associated with bottlenecks in genetic variation caused by geographic dispersal and extrinsic restraints caused by shifts in reproductive mode associated with either disease transmission or hybridization. Using species of the model yeast Saccharomyces and the model filamentous fungus Neurospora, we examine intrinsic restraints on recombination associated with mating systems that range from strictly clonal at one extreme to fully outbreeding at the other and those that lie between, including selfing and inbreeding. We also consider the effect of nomenclature on perception of reproductive mode and a means of comparing the relative impact of clonality and recombination on fungal populations. Last, we consider a recent hypothesis suggesting that fungi thought to have the most severe intrinsic constraints on recombination actually may have the fewest.

  11. Clonal reproduction in fungi

    PubMed Central

    Taylor, John W.; Hann-Soden, Christopher; Branco, Sara; Sylvain, Iman; Ellison, Christopher E.

    2015-01-01

    Research over the past two decades shows that both recombination and clonality are likely to contribute to the reproduction of all fungi. This view of fungi is different from the historical and still commonly held view that a large fraction of fungi are exclusively clonal and that some fungi have been exclusively clonal for hundreds of millions of years. Here, we first will consider how these two historical views have changed. Then we will examine the impact on fungal research of the concept of restrained recombination [Tibayrenc M, Ayala FJ (2012) Proc Natl Acad Sci USA 109 (48):E3305–E3313]. Using animal and human pathogenic fungi, we examine extrinsic restraints on recombination associated with bottlenecks in genetic variation caused by geographic dispersal and extrinsic restraints caused by shifts in reproductive mode associated with either disease transmission or hybridization. Using species of the model yeast Saccharomyces and the model filamentous fungus Neurospora, we examine intrinsic restraints on recombination associated with mating systems that range from strictly clonal at one extreme to fully outbreeding at the other and those that lie between, including selfing and inbreeding. We also consider the effect of nomenclature on perception of reproductive mode and a means of comparing the relative impact of clonality and recombination on fungal populations. Last, we consider a recent hypothesis suggesting that fungi thought to have the most severe intrinsic constraints on recombination actually may have the fewest. PMID:26195774

  12. Fundamental Travel Demand Model Example

    NASA Technical Reports Server (NTRS)

    Hanssen, Joel

    2010-01-01

    Instances of transportation models are abundant and detailed "how to" instruction is available in the form of transportation software help documentation. The purpose of this paper is to look at the fundamental inputs required to build a transportation model by developing an example passenger travel demand model. The example model reduces the scale to a manageable size for the purpose of illustrating the data collection and analysis required before the first step of the model begins. This aspect of the model development would not reasonably be discussed in software help documentation (it is assumed the model developer comes prepared). Recommendations are derived from the example passenger travel demand model to suggest future work regarding the data collection and analysis required for a freight travel demand model.

  13. Fundamental base closure environmental principles

    SciTech Connect

    Yim, R.A.

    1994-12-31

    Military base closures present a paradox. The rate, scale and timing of military base closures is historically unique. However, each base itself typically does not present unique problems. Thus, the challenge is to design innovative solutions to base redevelopment and remediation issues, while simultaneously adopting common, streamlined or pre-approved strategies to shared problems. The author presents six environmental principles that are fundamental to base closure. They are: remediation not clean up; remediation will impact reuse; reuse will impact remediation; remediation and reuse must be coordinated; environmental contamination must be evaluated as any other initial physical constraint on development, not as an overlay after plans are created; and remediation will impact development, financing and marketability.

  14. Fundamental reaction pathways during coprocessing

    SciTech Connect

    Stock, L.M.; Gatsis, J.G.

    1992-12-01

    The objective of this research was to investigate the fundamental reaction pathways in coal petroleum residuum coprocessing. Once the reaction pathways are defined, further efforts can be directed at improving those aspects of the chemistry of coprocessing that are responsible for the desired results such as high oil yields, low dihydrogen consumption, and mild reaction conditions. We decided to carry out this investigation by looking at four basic aspects of coprocessing: (1) the effect of fossil fuel materials on promoting reactions essential to coprocessing such as hydrogen atom transfer, carbon-carbon bond scission, and hydrodemethylation; (2) the effect of varied mild conditions on the coprocessing reactions; (3) determination of dihydrogen uptake and utilization under severe conditions as a function of the coal or petroleum residuum employed; and (4) the effect of varied dihydrogen pressure, temperature, and residence time on the uptake and utilization of dihydrogen and on the distribution of the coprocessed products. Accomplishments are described.

  15. Astronomical reach of fundamental physics.

    PubMed

    Burrows, Adam S; Ostriker, Jeremiah P

    2014-02-18

    Using basic physical arguments, we derive by dimensional and physical analysis the characteristic masses and sizes of important objects in the universe in terms of just a few fundamental constants. This exercise illustrates the unifying power of physics and the profound connections between the small and the large in the cosmos we inhabit. We focus on the minimum and maximum masses of normal stars, the corresponding quantities for neutron stars, the maximum mass of a rocky planet, the maximum mass of a white dwarf, and the mass of a typical galaxy. To zeroth order, we show that all these masses can be expressed in terms of either the Planck mass or the Chandrasekar mass, in combination with various dimensionless quantities. With these examples, we expose the deep interrelationships imposed by nature between disparate realms of the universe and the amazing consequences of the unifying character of physical law. PMID:24477692

  16. Holographic viscosity of fundamental matter.

    PubMed

    Mateos, David; Myers, Robert C; Thomson, Rowan M

    2007-03-01

    A holographic dual of a finite-temperature SU(Nc) gauge theory with a small number of flavors Nf or =1/4pi. Given the known results for the entropy density, the contribution of the fundamental matter eta fund is therefore enhanced at strong 't Hooft coupling lambda; for example, eta fund approximately lambda NcNfT3 in four dimensions. Other transport coefficients are analogously enhanced. These results hold with or without a baryon number chemical potential. PMID:17358523

  17. [INFORMATION, A FUNDAMENTAL PATIENT RIGHT?].

    PubMed

    Mémeteau, Gérard

    2015-03-01

    Although expressed before the "Lambert" case, which has led us to think about refusal and assent in the context of internal rights, conventional rights--and in the context of the patient's bed!--these simple remarks present the patient's right to medical information as a so-called fundamental right. But it can only be understood with a view to a treatment or other medical act; otherwise it has no reason to be and is only an academic exercise, however exciting, but not much use by itself. What if we reversed the terms of the problem: the right of the doctor to information? (The beautiful thesis of Ph. Gaston, Paris 8, 2 December 2014).

  18. Fundamental studies of polymer filtration

    SciTech Connect

    Smith, B.F.; Lu, M.T.; Robison, T.W.; Rogers, Y.C.; Wilson, K.V.

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The objectives of this project were (1) to develop an enhanced fundamental understanding of the coordination chemistry of hazardous-metal-ion complexation with water-soluble metal-binding polymers, and (2) to exploit this knowledge to develop improved separations for analytical methods, metals processing, and waste treatment. We investigated features of water-soluble metal-binding polymers that affect their binding constants and selectivity for selected transition metal ions. We evaluated backbone polymers using light scattering and ultrafiltration techniques to determine the effect of pH and ionic strength on the molecular volume of the polymers. The backbone polymers were incrementally functionalized with a metal-binding ligand. A procedure and analytical method to determine the absolute level of functionalization was developed and the results correlated with the elemental analysis, viscosity, and molecular size.

  19. Astronomical reach of fundamental physics.

    PubMed

    Burrows, Adam S; Ostriker, Jeremiah P

    2014-02-18

    Using basic physical arguments, we derive by dimensional and physical analysis the characteristic masses and sizes of important objects in the universe in terms of just a few fundamental constants. This exercise illustrates the unifying power of physics and the profound connections between the small and the large in the cosmos we inhabit. We focus on the minimum and maximum masses of normal stars, the corresponding quantities for neutron stars, the maximum mass of a rocky planet, the maximum mass of a white dwarf, and the mass of a typical galaxy. To zeroth order, we show that all these masses can be expressed in terms of either the Planck mass or the Chandrasekar mass, in combination with various dimensionless quantities. With these examples, we expose the deep interrelationships imposed by nature between disparate realms of the universe and the amazing consequences of the unifying character of physical law.

  20. Astronomical reach of fundamental physics

    PubMed Central

    Burrows, Adam S.; Ostriker, Jeremiah P.

    2014-01-01

    Using basic physical arguments, we derive by dimensional and physical analysis the characteristic masses and sizes of important objects in the universe in terms of just a few fundamental constants. This exercise illustrates the unifying power of physics and the profound connections between the small and the large in the cosmos we inhabit. We focus on the minimum and maximum masses of normal stars, the corresponding quantities for neutron stars, the maximum mass of a rocky planet, the maximum mass of a white dwarf, and the mass of a typical galaxy. To zeroth order, we show that all these masses can be expressed in terms of either the Planck mass or the Chandrasekar mass, in combination with various dimensionless quantities. With these examples, we expose the deep interrelationships imposed by nature between disparate realms of the universe and the amazing consequences of the unifying character of physical law. PMID:24477692

  1. Cognition is … Fundamentally Cultural

    PubMed Central

    Bender, Andrea; Beller, Sieghard

    2013-01-01

    A prevailing concept of cognition in psychology is inspired by the computer metaphor. Its focus on mental states that are generated and altered by information input, processing, storage and transmission invites a disregard for the cultural dimension of cognition, based on three (implicit) assumptions: cognition is internal, processing can be distinguished from content, and processing is independent of cultural background. Arguing against each of these assumptions, we point out how culture may affect cognitive processes in various ways, drawing on instances from numerical cognition, ethnobiological reasoning, and theory of mind. Given the pervasive cultural modulation of cognition—on all of Marr’s levels of description—we conclude that cognition is indeed fundamentally cultural, and that consideration of its cultural dimension is essential for a comprehensive understanding. PMID:25379225

  2. Fundamental issues in questionnaire design.

    PubMed

    Murray, P

    1999-07-01

    The questionnaire is probably the most common form of data collection tool used in nursing research. There is a misconception that anyone with a clear grasp of English and a modicum of common sense can design an effective questionnaire. Contrary to such common belief, this article will demonstrate that questionnaire design is a complex and time consuming process, but a necessary labour to ensure valid and reliable data is collected. In addition, meticulous construction is more likely to yield data that can be utilized in the pursuit of objective, quantitative and generalizable truths, upon which practice and policy decisions can be formulated. This article examines a myriad of fundamental issues surrounding questionnaire design, which encompass question wording, question order, presentation, administration and data collection, amongst other issues.

  3. Fundamentals of air quality systems

    SciTech Connect

    Noll, K.E.

    1999-08-01

    The book uses numerous examples to demonstrate how basic design concepts can be applied to the control of air emissions from industrial sources. It focuses on the design of air pollution control devices for the removal of gases and particles from industrial sources, and provides detailed, specific design methods for each major air pollution control system. Individual chapters provide design methods that include both theory and practice with emphasis on the practical aspect by providing numerous examples that demonstrate how air pollution control devices are designed. Contents include air pollution laws, air pollution control devices; physical properties of air, gas laws, energy concepts, pressure; motion of airborne particles, filter and water drop collection efficiency; fundamentals of particulate emission control; cyclones; fabric filters; wet scrubbers; electrostatic precipitators; control of volatile organic compounds; adsorption; incineration; absorption; control of gaseous emissions from motor vehicles; practice problems (with solutions) for the P.E. examination in environmental engineering. Design applications are featured throughout.

  4. Rare Isotopes and Fundamental Symmetries

    NASA Astrophysics Data System (ADS)

    Brown, B. Alex; Engel, Jonathan; Haxton, Wick; Ramsey-Musolf, Michael; Romalis, Michael; Savard, Guy

    2009-01-01

    Experiments searching for new interactions in nuclear beta decay / Klaus P. Jungmann -- The beta-neutrino correlation in sodium-21 and other nuclei / P. A. Vetter ... [et al.] -- Nuclear structure and fundamental symmetries/ B. Alex Brown -- Schiff moments and nuclear structure / J. Engel -- Superallowed nuclear beta decay: recent results and their impact on V[symbol] / J. C. Hardy and I. S. Towner -- New calculation of the isospin-symmetry breaking correlation to superallowed Fermi beta decay / I. S. Towner and J. C. Hardy -- Precise measurement of the [symbol]H to [symbol]He mass difference / D. E. Pinegar ... [et al.] -- Limits on scalar currents from the 0+ to 0+ decay of [symbol]Ar and isospin breaking in [symbol]Cl and [symbol]Cl / A. Garcia -- Nuclear constraints on the weak nucleon-nucleon interaction / W. C. Haxton -- Atomic PNC theory: current status and future prospects / M. S. Safronova -- Parity-violating nucleon-nucleon interactions: what can we learn from nuclear anapole moments? / B. Desplanques -- Proposed experiment for the measurement of the anapole moment in francium / A. Perez Galvan ... [et al.] -- The Radon-EDM experiment / Tim Chupp for the Radon-EDM collaboration -- The lead radius Eexperiment (PREX) and parity violating measurements of neutron densities / C. J. Horowitz -- Nuclear structure aspects of Schiff moment and search for collective enhancements / Naftali Auerbach and Vladimir Zelevinsky -- The interpretation of atomic electric dipole moments: Schiff theorem and its corrections / C. -P. Liu -- T-violation and the search for a permanent electric dipole moment of the mercury atom / M. D. Swallows ... [et al.] -- The new concept for FRIB and its potential for fundamental interactions studies / Guy Savard -- Collinear laser spectroscopy and polarized exotic nuclei at NSCL / K. Minamisono -- Environmental dependence of masses and coupling constants / M. Pospelov.

  5. Fundamental enabling issues in nanotechnology :

    SciTech Connect

    Floro, Jerrold Anthony; Foiles, Stephen Martin; Hearne, Sean Joseph; Hoyt, Jeffrey John; Seel, Steven Craig; Webb, Edmund Blackburn,; Morales, Alfredo Martin; Zimmerman, Jonathan A.

    2007-10-01

    To effectively integrate nanotechnology into functional devices, fundamental aspects of material behavior at the nanometer scale must be understood. Stresses generated during thin film growth strongly influence component lifetime and performance; stress has also been proposed as a mechanism for stabilizing supported nanoscale structures. Yet the intrinsic connections between the evolving morphology of supported nanostructures and stress generation are still a matter of debate. This report presents results from a combined experiment and modeling approach to study stress evolution during thin film growth. Fully atomistic simulations are presented predicting stress generation mechanisms and magnitudes during all growth stages, from island nucleation to coalescence and film thickening. Simulations are validated by electrodeposition growth experiments, which establish the dependence of microstructure and growth stresses on process conditions and deposition geometry. Sandia is one of the few facilities with the resources to combine experiments and modeling/theory in this close a fashion. Experiments predicted an ongoing coalescence process that generates signficant tensile stress. Data from deposition experiments also supports the existence of a kinetically limited compressive stress generation mechanism. Atomistic simulations explored island coalescence and deposition onto surfaces intersected by grain boundary structures to permit investigation of stress evolution during later growth stages, e.g. continual island coalescence and adatom incorporation into grain boundaries. The predictive capabilities of simulation permit direct determination of fundamental processes active in stress generation at the nanometer scale while connecting those processes, via new theory, to continuum models for much larger island and film structures. Our combined experiment and simulation results reveal the necessary materials science to tailor stress, and therefore performance, in

  6. Reproductive governance in Latin America.

    PubMed

    Morgan, Lynn M; Roberts, Elizabeth F S

    2012-01-01

    This paper develops the concept of reproductive governance as an analytic tool for tracing the shifting political rationalities of population and reproduction. As advanced here, the concept of reproductive governance refers to the mechanisms through which different historical configurations of actors - such as state, religious, and international financial institutions, NGOs, and social movements - use legislative controls, economic inducements, moral injunctions, direct coercion, and ethical incitements to produce, monitor, and control reproductive behaviours and population practices. Examples are drawn from Latin America, where reproductive governance is undergoing a dramatic transformation as public policy conversations are coalescing around new moral regimes and rights-based actors through debates about abortion, emergency contraception, sterilisation, migration, and assisted reproductive technologies. Reproductive discourses are increasingly framed through morality and contestations over 'rights', where rights-bearing citizens are pitted against each other in claiming reproductive, sexual, indigenous, and natural rights, as well as the 'right to life' of the unborn. The concept of reproductive governance can be applied to other settings in order to understand shifting political rationalities within the domain of reproduction. PMID:22889430

  7. The role of autophagy in reproduction from gametogenesis to parturition.

    PubMed

    Kanninen, Tomi T; de Andrade Ramos, Bruna Ribeiro; Witkin, Steven S

    2013-11-01

    Autophagy is an intracellular process responsible for maintaining cellular homeostasis by the removal of cytoplasmic organelles, intracellular bacteria and viruses, and is a critical component of both the innate and acquired immune systems. A failure in physiological activation, assembly and function of the autophagic pathway has been implicated in a broad range of diseases including neurogenerative diseases, cardiopathy, infectious diseases, autoimmunity and cancer. Its involvement in reproduction, however, has not been extensively studied. Its activity is fundamental to many processes across the reproduction spectrum from development of the primordial follicle and spermatozoa to embryogenesis, placental development and maintaining uterine quiescence during pregnancy. Malfunctions in autophagy are associated with deleterious repercussions throughout reproduction. In this review we examine what is known about the involvement of autophagy in gamete formation, early post-fertilization embryogenesis, placental development and parturition, and propose promising areas for future research.

  8. Fundamentals and Techniques of Nonimaging

    SciTech Connect

    O'Gallagher, J. J.; Winston, R.

    2003-07-10

    This is the final report describing a long term basic research program in nonimaging optics that has led to major advances in important areas, including solar energy, fiber optics, illumination techniques, light detectors, and a great many other applications. The term ''nonimaging optics'' refers to the optics of extended sources in systems for which image forming is not important, but effective and efficient collection, concentration, transport, and distribution of light energy is. Although some of the most widely known developments of the early concepts have been in the field of solar energy, a broad variety of other uses have emerged. Most important, under the auspices of this program in fundamental research in nonimaging optics established at the University of Chicago with support from the Office of Basic Energy Sciences at the Department of Energy, the field has become very dynamic, with new ideas and concepts continuing to develop, while applications of the early concepts continue to be pursued. While the subject began as part of classical geometrical optics, it has been extended subsequently to the wave optics domain. Particularly relevant to potential new research directions are recent developments in the formalism of statistical and wave optics, which may be important in understanding energy transport on the nanoscale. Nonimaging optics permits the design of optical systems that achieve the maximum possible concentration allowed by physical conservation laws. The earliest designs were constructed by optimizing the collection of the extreme rays from a source to the desired target: the so-called ''edge-ray'' principle. Later, new concentrator types were generated by placing reflectors along the flow lines of the ''vector flux'' emanating from lambertian emitters in various geometries. A few years ago, a new development occurred with the discovery that making the design edge-ray a functional of some other system parameter permits the construction of whole

  9. VARIATIONS IN REPRODUCTIVE TOXICANT IDENTIFICATION

    SciTech Connect

    Simmons, F

    2008-05-13

    Reproductive toxicants are a very important class of compounds. They present unique hazards to those of child bearing ages, perform their 'dirty work' using a wide variety of mechanisms on a number of different organs, and are regulatorily important. Because of all of this, properly identifying reproductive toxicants is important, but fraught with difficulty. In this paper we will describe types or reproductive toxicants, their importance, and both mistakes and good practices that people who are not experts in reproductive toxicology may use in their attempts to identify them. Additionally, this paper will focus on chemical reproductive toxicants and will not address biological agents that could affect reproductive toxicity although many principles outlined here could be applied to that endeavor.

  10. Do goldfish miss the fundamental?

    NASA Astrophysics Data System (ADS)

    Fay, Richard R.

    2003-10-01

    The perception of harmonic complexes was studied in goldfish using classical respiratory conditioning and a stimulus generalization paradigm. Groups of animals were initially conditioned to several harmonic complexes with a fundamental frequency (f0) of 100 Hz. ln some cases the f0 component was present, and in other cases, the f0 component was absent. After conditioning, animals were tested for generalization to novel harmonic complexes having different f0's, some with f0 present and some with f0 absent. Generalization gradients always peaked at 100 Hz, indicating that the pitch value of the conditioning complexes was consistent with the f0, whether or not f0 was present in the conditioning or test complexes. Thus, goldfish do not miss the fundmental with respect to a pitch-like perceptual dimension. However, generalization gradients tended to have different skirt slopes for the f0-present and f0-absent conditioning and test stimuli. This suggests that goldfish distinguish between f0 present/absent stimuli, probably on the basis of a timbre-like perceptual dimension. These and other results demonstrate that goldfish respond to complex sounds as if they possessed perceptual dimensions similar to pitch and timbre as defined for human and other vertebrate listeners. [Work supported by NIH/NIDCD.

  11. Levitated Optomechanics for Fundamental Physics

    NASA Astrophysics Data System (ADS)

    Rashid, Muddassar; Bateman, James; Vovrosh, Jamie; Hempston, David; Ulbricht, Hendrik

    2015-05-01

    Optomechanics with levitated nano- and microparticles is believed to form a platform for testing fundamental principles of quantum physics, as well as find applications in sensing. We will report on a new scheme to trap nanoparticles, which is based on a parabolic mirror with a numerical aperture of 1. Combined with achromatic focussing, the setup is a cheap and readily straightforward solution to trapping nanoparticles for further study. Here, we report on the latest progress made in experimentation with levitated nanoparticles; these include the trapping of 100 nm nanodiamonds (with NV-centres) down to 1 mbar as well as the trapping of 50 nm Silica spheres down to 10?4 mbar without any form of feedback cooling. We will also report on the progress to implement feedback stabilisation of the centre of mass motion of the trapped particle using digital electronics. Finally, we argue that such a stabilised particle trap can be the particle source for a nanoparticle matterwave interferometer. We will present our Talbot interferometer scheme, which holds promise to test the quantum superposition principle in the new mass range of 106 amu. EPSRC, John Templeton Foundation.

  12. Fluorescence lifetimes: fundamentals and interpretations.

    PubMed

    Noomnarm, Ulai; Clegg, Robert M

    2009-01-01

    Fluorescence measurements have been an established mainstay of photosynthesis experiments for many decades. Because in the photosynthesis literature the basics of excited states and their fates are not usually described, we have presented here an easily understandable text for biology students in the style of a chapter in a text book. In this review we give an educational overview of fundamental physical principles of fluorescence, with emphasis on the temporal response of emission. Escape from the excited state of a molecule is a dynamic event, and the fluorescence emission is in direct kinetic competition with several other pathways of de-excitation. It is essentially through a kinetic competition between all the pathways of de-excitation that we gain information about the fluorescent sample on the molecular scale. A simple probability allegory is presented that illustrates the basic ideas that are important for understanding and interpreting most fluorescence experiments. We also briefly point out challenges that confront the experimenter when interpreting time-resolved fluorescence responses.

  13. Fundamental studies of fusion plasmas

    SciTech Connect

    Aamodt, R.E.; Catto, P.J.; D'Ippolito, D.A.; Myra, J.R.; Russell, D.A.

    1992-05-26

    The major portion of this program is devoted to critical ICH phenomena. The topics include edge physics, fast wave propagation, ICH induced high frequency instabilities, and a preliminary antenna design for Ignitor. This research was strongly coordinated with the world's experimental and design teams at JET, Culham, ORNL, and Ignitor. The results have been widely publicized at both general scientific meetings and topical workshops including the speciality workshop on ICRF design and physics sponsored by Lodestar in April 1992. The combination of theory, empirical modeling, and engineering design in this program makes this research particularly important for the design of future devices and for the understanding and performance projections of present tokamak devices. Additionally, the development of a diagnostic of runaway electrons on TEXT has proven particularly useful for the fundamental understanding of energetic electron confinement. This work has led to a better quantitative basis for quasilinear theory and the role of magnetic vs. electrostatic field fluctuations on electron transport. An APS invited talk was given on this subject and collaboration with PPPL personnel was also initiated. Ongoing research on these topics will continue for the remainder fo the contract period and the strong collaborations are expected to continue, enhancing both the relevance of the work and its immediate impact on areas needing critical understanding.

  14. Reproductive function in epilepsy.

    PubMed

    Cramer, J A; Jones, E E

    1991-01-01

    The hypothalamic-pituitary-gonadal axis is a complex system within which both positive and negative feedback occur among its elements and higher brain systems. The occurrence of seizures and changes in the secretion of pituitary hormones can affect the feedback loop. Both seizures and antiepileptic drugs can affect the hypothalamic-pituitary-gonadal axis of males and females and cause changes in hormones and sexuality. Reproductive dysfunction has a social impact because of reduced fertility. Once conception occurs, live birth rates are not diminished. Prospective studies of men and women with epilepsy are needed.

  15. Human reproductive issues in space

    NASA Technical Reports Server (NTRS)

    Santy, Patricia A.; Jennings, Richard T.

    1992-01-01

    A review of reproductive functioning in animal species studied during space flight demonstrated that most species were affected significantly by the absence of gravity and/or the presence of radiation. These two factors induced alterations in normal reproductive functioning independently of, as well as in combination with, each other. Based on animal models, several potential problem areas regarding human reproductive physiology and functioning in the space environment were identified. While there are no current space flight investigations, the animal studies suggest priorities for future research in human reproduction. Such studies will be critical for the successful colonization of the space frontier.

  16. Selective advantage for sexual reproduction

    NASA Astrophysics Data System (ADS)

    Tannenbaum, Emmanuel

    2006-06-01

    This paper develops a simplified model for sexual reproduction within the quasispecies formalism. The model assumes a diploid genome consisting of two chromosomes, where the fitness is determined by the number of chromosomes that are identical to a given master sequence. We also assume that there is a cost to sexual reproduction, given by a characteristic time τseek during which haploid cells seek out a mate with which to recombine. If the mating strategy is such that only viable haploids can mate, then when τseek=0 , it is possible to show that sexual reproduction will always out compete asexual reproduction. However, as τseek increases, sexual reproduction only becomes advantageous at progressively higher mutation rates. Once the time cost for sex reaches a critical threshold, the selective advantage for sexual reproduction disappears entirely. The results of this paper suggest that sexual reproduction is not advantageous in small populations per se, but rather in populations with low replication rates. In this regime, the cost for sex is sufficiently low that the selective advantage obtained through recombination leads to the dominance of the strategy. In fact, at a given replication rate and for a fixed environment volume, sexual reproduction is selected for in high populations because of the reduced time spent finding a reproductive partner.

  17. Fundamental mechanisms of micromachine reliability

    SciTech Connect

    DE BOER,MAARTEN P.; SNIEGOWSKI,JEFFRY J.; KNAPP,JAMES A.; REDMOND,JAMES M.; MICHALSKE,TERRY A.; MAYER,THOMAS K.

    2000-01-01

    Due to extreme surface to volume ratios, adhesion and friction are critical properties for reliability of Microelectromechanical Systems (MEMS), but are not well understood. In this LDRD the authors established test structures, metrology and numerical modeling to conduct studies on adhesion and friction in MEMS. They then concentrated on measuring the effect of environment on MEMS adhesion. Polycrystalline silicon (polysilicon) is the primary material of interest in MEMS because of its integrated circuit process compatibility, low stress, high strength and conformal deposition nature. A plethora of useful micromachined device concepts have been demonstrated using Sandia National Laboratories' sophisticated in-house capabilities. One drawback to polysilicon is that in air the surface oxidizes, is high energy and is hydrophilic (i.e., it wets easily). This can lead to catastrophic failure because surface forces can cause MEMS parts that are brought into contact to adhere rather than perform their intended function. A fundamental concern is how environmental constituents such as water will affect adhesion energies in MEMS. The authors first demonstrated an accurate method to measure adhesion as reported in Chapter 1. In Chapter 2 through 5, they then studied the effect of water on adhesion depending on the surface condition (hydrophilic or hydrophobic). As described in Chapter 2, they find that adhesion energy of hydrophilic MEMS surfaces is high and increases exponentially with relative humidity (RH). Surface roughness is the controlling mechanism for this relationship. Adhesion can be reduced by several orders of magnitude by silane coupling agents applied via solution processing. They decrease the surface energy and render the surface hydrophobic (i.e. does not wet easily). However, only a molecular monolayer coats the surface. In Chapters 3-5 the authors map out the extent to which the monolayer reduces adhesion versus RH. They find that adhesion is independent of

  18. Fundamental Mechanisms of Interface Roughness

    SciTech Connect

    Randall L. Headrick

    2009-01-06

    Publication quality results were obtained for several experiments and materials systems including: (i) Patterning and smoothening of sapphire surfaces by energetic Ar+ ions. Grazing Incidence Small Angle X-ray Scattering (GISAXS) experiments were performed in the system at the National Synchrotron Light Source (NSLS) X21 beamline. Ar+ ions in the energy range from 300 eV to 1000 eV were used to produce ripples on the surfaces of single-crystal sapphire. It was found that the ripple wavelength varies strongly with the angle of incidence of the ions, which increase significantly as the angle from normal is varied from 55° to 35°. A smooth region was found for ion incidence less than 35° away from normal incidence. In this region a strong smoothening mechanism with strength proportional to the second derivative of the height of the surface was found to be responsible for the effect. The discovery of this phase transition between stable and unstable regimes as the angle of incidence is varied has also stimulated new work by other groups in the field. (ii) Growth of Ge quantum dots on Si(100) and (111). We discovered the formation of quantum wires on 4° misoriented Si(111) using real-time GISAXS during the deposition of Ge. The results represent the first time-resolved GISAXS study of Ge quantum dot formation. (iii) Sputter deposition of amorphous thin films and multilayers composed of WSi2 and Si. Our in-situ GISAXS experiments reveal fundamental roughening and smoothing phenomena on surfaces during film deposition. The main results of this work is that the WSi2 layers actually become smoother during deposition due to the smoothening effect of energetic particles in the sputter deposition process.

  19. Obesity and reproduction.

    PubMed

    Bray, G A

    1997-10-01

    Obesity produces a variety of alterations in the reproductive system and, similarly, manipulations of the hypothalamic-pituitary-gonadal axis produce changes in food intake, body weight and fat distribution. In men, the primary effects of obesity are a weight related reduction in testosterone and, with massive overweight, a reduction in free testosterone. In females, the weight-related development of menarche leads to earlier menarche in obese girls than in normal weight girls. One explanation for the relationship of fatness to menarche may be the ob protein (leptin) which is defective in the obese (ob/ob) mouse. Leptin is secreted by adipose tissue in proportion to the quantity of fat and may serve as a signal to the hypothalamus that fat stores are adequate to nourish a conceptus to term. In women, parity affects obesity and obesity in turn affects the regularity of the menstrual cycle. In many experimental animals with obesity, particularly the genetic forms of obesity, there is complete infertility in the females and marked impairment of reproductive function in the males. In animals with hypothalamic lesions, there is a gender effect on the magnitude of weight gain associated with the sexually dimorphic regions in the medial preoptic area. Castration with removal of oestrogen is followed by obesity in female animals and this can be prevented, as can most forms of obesity, by adrenalectomy. The inhibitory effects of oestrogen on food intake may result from suppression of neuropeptide-Y or galanin peptidergic systems in the arcuate nucleus or medial preoptic area.

  20. Stem cells and reproduction

    PubMed Central

    Du, Hongling; Taylor, Hugh S.

    2011-01-01

    Purpose of review To review the latest developments in reproductive tract stem cell biology. Recent findings In 2004, two studies indicated that ovaries contain stem cells which form oocytes in adults and that can be cultured in vitro into mature oocytes. A live birth after orthotopic transplantation of cyropreserved ovarian tissue in a woman whose ovaries were damaged by chemotherapy demonstrates the clinical potential of these cells. In the same year, another study provided novel evidence of endometrial regeneration by stem cells in women who received bone marrow transplants. This finding has potential for the use in treatment of uterine disorders. It also supports a new theory for the cause of endometriosis, which may have its origin in ectopic transdifferentiation of stem cells. Several recent studies have demonstrated that fetal cells enter the maternal circulation and generate microchimerism in the mother. The uterus is a dynamic organ permeable to fetal stem cells, capable of transdifferentiation and an end organ in which bone marrow stem cells may differentiate. Finally stem cell transformation can be an underlying cause of ovarian cancer. Summary Whereas we are just beginning to understand stem cells, the potential implications of stem cells to reproductive biology and medicine are apparent. PMID:20305558

  1. Inequalities cause reproductive deaths.

    PubMed

    Dillner, L

    1995-07-15

    A US organization, Population Action International, is reported in this article to have released findings on the health risks for women in 118 countries. Countries are ranked on 10 indicators, including such indicators as the number of births to women aged under 19 years, the availability of legal abortion, maternal mortality, and level of prenatal care. Italy, Denmark, Norway, and Sweden are identified as countries with low reproductive risk for women. The worst ranked countries are identified as Zaire, Angola, and Somalia. 21 countries were placed in the high risk group, of which only two, Haiti and Afghanistan, are not located in Africa. Editorial comment in the report is described in this article as reflecting the position that countries fail in investing in women's health, with devastating consequences. Some poor countries, such as Cuba, Tunisia, and Costa Rica, are cited for their investments in health care and family planning. The report is described as asserting that low status also prevents women from maintaining good health. Both access to reproductive health services and changing social norms supporting traditional roles in early and frequent childbearing are important to women's improved health status. It is also important for women to have educational and economic opportunities. Population Action International is seeking greater foreign aid contributions for family planning services in developing countries, emergency care in childbirth, health education, AIDS education, and access to safe abortion services.

  2. Sound field reproduction as an equivalent acoustical scattering problem.

    PubMed

    Fazi, Filippo Maria; Nelson, Philip A

    2013-11-01

    Given a continuous distribution of acoustic sources, the determination of the source strength that ensures the synthesis of a desired sound field is shown to be identical to the solution of an equivalent acoustic scattering problem. The paper begins with the presentation of the general theory that underpins sound field reproduction with secondary sources continuously arranged on the boundary of the reproduction region. The process of reproduction by a continuous source distribution is modeled by means of an integral operator (the single layer potential). It is then shown how the solution of the sound reproduction problem corresponds to that of an equivalent scattering problem. Analytical solutions are computed for two specific instances of this problem, involving, respectively, the use of a secondary source distribution in spherical and planar geometries. The results are shown to be the same as those obtained with analyses based on High Order Ambisonics and Wave Field Synthesis, respectively, thus bringing to light a fundamental analogy between these two methods of sound reproduction. Finally, it is shown how the physical optics (Kirchhoff) approximation enables the derivation of a high-frequency simplification for the problem under consideration, this in turn being related to the secondary source selection criterion reported in the literature on Wave Field Synthesis.

  3. Reproduction-longevity trade-offs reflect diet, not adaptation.

    PubMed

    Attisano, A; Moore, A J; Moore, P J

    2012-05-01

    A tenet of life history evolution is that allocation of limited resources results in trade-offs, such as that between reproduction and lifespan. Reproduction and lifespan are also influenced proximately by differences in the availability of specific nutrients. What is unknown is how the evolution of the ability to use a nutritionally novel diet is reflected in this fundamental trade-off. Does the evolution of the ability to use a nutritionally novel food maintain the trade-off in reproduction and longevity, or do the proximate effects of nutrition alter the adapted trade-off? We tested this by measuring trade-offs in male milkweed bugs, Oncopeltus fasciatus, fed either an adapted diet of sunflower or the ancestral diet of milkweed. Sunflower-fed males lived longer but invested less in reproduction, both in mating and fertility. Milkweed-fed males invested in both mating and fertility at the expense of survival. The evolution of an expanded diet was not constrained by the existing trade-off, but instead was accompanied by a different trade-off between reproduction and longevity. We suggest that this occurs because diets differ in promoting germ line development or longevity. PMID:22356585

  4. Comparative analysis reveals the underlying mechanism of vertebrate seasonal reproduction.

    PubMed

    Ikegami, Keisuke; Yoshimura, Takashi

    2016-02-01

    Animals utilize photoperiodic changes as a calendar to regulate seasonal reproduction. Birds have highly sophisticated photoperiodic mechanisms and functional genomics analysis in quail uncovered the signal transduction pathway regulating avian seasonal reproduction. Birds detect light with deep brain photoreceptors. Long day (LD) stimulus induces secretion of thyroid-stimulating hormone (TSH) from the pars tuberalis (PT) of the pituitary gland. PT-derived TSH locally activates thyroid hormone (TH) in the hypothalamus, which induces gonadotropin-releasing hormone (GnRH) and hence gonadotropin secretion. However, during winter, low temperatures increase serum TH for adaptive thermogenesis, which accelerates germ cell apoptosis by activating the genes involved in metamorphosis. Therefore, TH has a dual role in the regulation of seasonal reproduction. Studies using TSH receptor knockout mice confirmed the involvement of PT-derived TSH in mammalian seasonal reproduction. In addition, studies in mice revealed that the tissue-specific glycosylation of TSH diversifies its function in the circulation to avoid crosstalk. In contrast to birds and mammals, one of the molecular machineries necessary for the seasonal reproduction of fish are localized in the saccus vasculosus from the photoreceptor to the neuroendocrine output. Thus, comparative analysis is a powerful tool to uncover the universality and diversity of fundamental properties in various organisms.

  5. Mouse models of altered gonadotrophin action: insight into male reproductive disorders.

    PubMed

    Jonas, Kim C; Oduwole, Olayiwola O; Peltoketo, Hellevi; Rulli, Susana B; Huhtaniemi, Ilpo T

    2014-10-01

    The advent of technologies to genetically manipulate the mouse genome has revolutionised research approaches, providing a unique platform to study the causality of reproductive disorders in vivo. With the relative ease of generating genetically modified (GM) mouse models, the last two decades have yielded multiple loss-of-function and gain-of-function mutation mouse models to explore the role of gonadotrophins and their receptors in reproductive pathologies. This work has provided key insights into the molecular mechanisms underlying reproductive disorders with altered gonadotrophin action, revealing the fundamental roles of these pituitary hormones and their receptors in the hypothalamic-pituitary-gonadal axis. This review will describe GM mouse models of gonadotrophins and their receptors with enhanced or diminished actions, specifically focusing on the male. We will discuss the mechanistic insights gained from these models into male reproductive disorders, and the relationship and understanding provided into male human reproductive disorders originating from altered gonadotrophin action.

  6. Astronomia Motivadora no Ensino Fundamental

    NASA Astrophysics Data System (ADS)

    Melo, J.; Voelzke, M. R.

    2008-09-01

    O objetivo principal deste trabalho é procurar desenvolver o interesse dos alunos pelas ciências através da Astronomia. Uma pesquisa com perguntas sobre Astronomia foi realizada junto a 161 alunos do Ensino Fundamental, com o intuito de descobrir conhecimentos prévios dos alunos sobre o assunto. Constatou-se, por exemplo, que 29,3% da 6ª série responderam corretamente o que é eclipse, 30,0% da 8ª série acertaram o que a Astronomia estuda, enquanto 42,3% dos alunos da 5ª série souberam definir o Sol. Pretende-se ampliar as turmas participantes e trabalhar, principalmente de forma prática com: dimensões e escalas no Sistema Solar, construção de luneta, questões como dia e noite, estações do ano e eclipses. Busca-se abordar, também, outros conteúdos de Física tais como a óptica na construção da luneta, e a mecânica no trabalho com escalas e medidas, e ao utilizar uma luminária para representar o Sol na questão do eclipse, e de outras disciplinas como a Matemática na transformação de unidades, regras de três; Artes na modelagem ou desenho dos planetas; a própria História com relação à busca pela origem do universo, e a Informática que possibilita a busca mais rápida por informações, além de permitir simulações e visualizações de imagens importantes. Acredita-se que a Astronomia é importante no processo ensino aprendizagem, pois permite a discussão de temas curiosos como, por exemplo, a origem do universo, viagens espaciais a existência ou não de vida em outros planetas, além de temas atuais como as novas tecnologias.

  7. [Ethical problems in genetics and reproduction medicine].

    PubMed

    Gruber, Ch J; Huber, J C

    2002-01-01

    Novel knowledge in the fields of molecular biology, genetics and reproductive medicine will revolutionize medicine in the near future. Among many new therapeutical aspects arise a number ethical questions that include preimplantation diagnostics, embryonic stem cell research and gene therapy. Believing in scientific progress is often criticized but today it is primarily ignorance as well as fundamentalism that block sensible discussions. In the future it shall be of importance to differentiate between "to be alive" and "to have a life", hence yielding a new definition of the term "life". Also important is to keep in mind the difference between individual moral claims and general ethics. Without doubt, the current developments in medicine will bring about interesting consequences but the inherent dangers are recognizable as well. However, only a positive attitude will result in beneficial developments. More flexibility on all sides will be needed in the concurrent discussion process.

  8. Assisted reproductive practice: religious perspectives.

    PubMed

    Schenker, Joscph G

    2005-03-01

    It is important to those who practise reproductive techniques to learn about different religious perspectives related to reproductive health problems. Religious groups are active in influencing the public regarding bioethical positions, and this is particularly evident with issues concerning procreation, abortion and infertility therapy. The Jewish attitude towards procreation is derived from the first commandment of God to Adam to 'Be fruitful and multiply'. Judaism allows the practice of all techniques of assisted reproduction when the oocyte and spermatozoon originate from the wife and husband respectively. The attitude toward reproductive practice varies among Christian groups. While assisted reproduction is not accepted by the Vatican, it may be practised by Protestant, Anglican and other denominations. According to traditional Christian views, beginning at conception, the embryo has moral status as a human being, and thus most assisted reproductive technologies are forbidden. According to Islam, the procedures of IVF and embryo transfer are acceptable, although they can be performed only for husband and wife. Developments in science and technology and corresponding clinical applications raise new religious questions, often without clear answers. The role of theology in bioethics is integral to clarify perceived attitudes toward these developments for different religious communities. This paper presents the attitude of monotheistic religions to therapeutic procedures, such as IVF-embryo transfer, spermatozoa, oocytes, embryo donation, cryopreservation of genetic material, surrogacy, posthumous reproduction, gender preselection, reproductive and therapeutic cloning.

  9. Phthalates as developmental reproductive toxicants

    EPA Science Inventory

    PE are a large family ofcompounds used in a wide array ofconsumer, industrial and medical products. Studies have shown that in utero treatment with PE such as diethyl hexyl phthalate (DEHP) during the critical period offetal reproductive development produced male reproductive mal...

  10. Mechanical Signaling in Reproductive Tissues

    PubMed Central

    Jorge, Soledad; Chang, Sydney; Barzilai, Joshua J.; Leppert, Phyllis

    2014-01-01

    The organs of the female reproductive system are among the most dynamic tissues in the human body, undergoing repeated cycles of growth and involution from puberty through menopause. To achieve such impressive plasticity, reproductive tissues must respond not only to soluble signals (hormones, growth factors, and cytokines) but also to physical cues (mechanical forces and osmotic stress) as well. Here, we review the mechanisms underlying the process of mechanotransduction—how signals are conveyed from the extracellular matrix that surrounds the cells of reproductive tissues to the downstream molecules and signaling pathways that coordinate the cellular adaptive response to external forces. Our objective was to examine how mechanical forces contribute significantly to physiological functions and pathogenesis in reproductive tissues. We highlight how widespread diseases of the reproductive tract, from preterm labor to tumors of the uterus and breast, result from an impairment in mechanical signaling. PMID:25001021

  11. Monotreme and marsupial reproduction.

    PubMed

    Renfree, M B

    1995-01-01

    Marsupials were regarded as curiosities by their early European discoverers, animals to be wondered at. Monotremes were even more surprising; the platypus was such an amalgam of characters that it was thought to be a hoax. They were recognized very early as mammals that could make a major contribution to our understanding of reproductive processes, and work on marsupials at the turn of the century was much in evidence. It is, however, only in the past two decades, and especially in the past few years that marsupial research has regained this position. There is no doubt that future research will strengthen this contribution, but we are faced with serious conservation questions that must be solved if we are to maintain these wonderful animals as a resource for future generations. PMID:8848565

  12. The Reproductive System.

    PubMed

    Pask, Andrew

    2016-01-01

    Correct sexual development is arguably the most important trait in an organism's life history since it is directly related to its genetic fitness. The developing gonad houses the germ cells, the only legacy we pass on to subsequent generations. Given the pivotal importance of correct reproductive function, it is confounding that disorders of sex development (DSDs) are among the most common congenital abnormalities in humans (Lee et al. J Pediatr Urol 8(6):611-615, 2012). Urogenital development is a highly complex process involving coordinated interactions between molecular and hormonal pathways in a tightly regulated order. The controls that regulate some of the key events in this process are beginning to be unraveled. This chapter provides an overview of our understanding of urogenital development from the gonads to the urogenital ducts and external genitalia. PMID:26659484

  13. Reproductive health in adolescence.

    PubMed

    Friedman, H L

    1994-01-01

    The health and well-being of adolescents is closely intertwined with their physical, psychological and social development, but this is put at risk by sexual and reproductive health hazards which are increasing in much of the world. Changes in population growth and distribution, the rise of telecommunications, the increase in travel and a decline in the family, as well as a generally earlier start of menarche and later age of marriage are contributing to an increase in unprotected sexual relations before marriage. This, combined with risks from early marriage, result in too early or unwanted pregnancy and childbirth, induced abortion in hazardous circumstances and sexually transmitted diseases, including HIV infection leading to AIDS. With more than half the world's population below the age of 25, and 4 out of 5 young people living in developing countries with inadequate access to prevention and care, there is an urgent need for action. Young women are particularly vulnerable. Mortality and morbidity from early pregnancy whether ending in childbirth or abortion, is much higher for the younger adolescent. Young women, especially those who have less formal education, are more vulnerable to pressures for marriage, or sexual relations before marriage, often with older men. Young people generally lack adequate knowledge about their own development and information on how to get help. Those who could help are rarely trained for working with adolescents, and services which are generally designed for adults or children often deter young people from getting help when they most need it. Policy and legislation relating to sexual and reproductive health issues are often contradictory, and unclear or unenforced.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Reproductive Rights or Reproductive Justice? Lessons from Argentina.

    PubMed

    Morgan, Lynn

    2015-06-11

    Argentine sexual and reproductive rights activists insist on using the language and framework of "human rights," even when many reproductive rights activists in the US and elsewhere now prefer the framework of "reproductive justice." Reflecting on conversations with Argentine feminist anthropologists, social scientists, and reproductive rights activists, this paper analyzes why the Argentine movement to legalize abortion relies on the contested concept of human rights. Its conclusion that "women's rights are human rights" is a powerful claim in post-dictatorship politics where abortion is not yet legal and the full scope of women's rights has yet to be included in the government's human rights agenda. Argentine feminist human rights activists have long been attentive to the ways that social class, gender, migration, and racism intersect with reproduction. Because their government respects and responds to a human rights framework, however, they have not felt it necessary--as U.S. feminists have--to invent a new notion of reproductive justice in order to be heard. Given the increasing popularity of reproductive justice in health and human rights, the Argentine case shows that rights-based claims can still be politically useful when a State values the concept of human rights.

  15. Reproductive Rights or Reproductive Justice? Lessons from Argentina.

    PubMed

    Morgan, Lynn

    2015-01-01

    Argentine sexual and reproductive rights activists insist on using the language and framework of "human rights," even when many reproductive rights activists in the US and elsewhere now prefer the framework of "reproductive justice." Reflecting on conversations with Argentine feminist anthropologists, social scientists, and reproductive rights activists, this paper analyzes why the Argentine movement to legalize abortion relies on the contested concept of human rights. Its conclusion that "women's rights are human rights" is a powerful claim in post-dictatorship politics where abortion is not yet legal and the full scope of women's rights has yet to be included in the government's human rights agenda. Argentine feminist human rights activists have long been attentive to the ways that social class, gender, migration, and racism intersect with reproduction. Because their government respects and responds to a human rights framework, however, they have not felt it necessary--as U.S. feminists have--to invent a new notion of reproductive justice in order to be heard. Given the increasing popularity of reproductive justice in health and human rights, the Argentine case shows that rights-based claims can still be politically useful when a State values the concept of human rights. PMID:26204578

  16. Unisexual reproduction reverses Muller's ratchet.

    PubMed

    Roach, Kevin C; Heitman, Joseph

    2014-11-01

    Cryptococcus neoformans is a pathogenic basidiomycetous fungus that engages in outcrossing, inbreeding, and selfing forms of unisexual reproduction as well as canonical sexual reproduction between opposite mating types. Long thought to be clonal, >99% of sampled environmental and clinical isolates of C. neoformans are MATα, limiting the frequency of opposite mating-type sexual reproduction. Sexual reproduction allows eukaryotic organisms to exchange genetic information and shuffle their genomes to avoid the irreversible accumulation of deleterious changes that occur in asexual populations, known as Muller's ratchet. We tested whether unisexual reproduction, which dispenses with the requirement for an opposite mating-type partner, is able to purge the genome of deleterious mutations. We report that the unisexual cycle can restore mutant strains of C. neoformans to wild-type genotype and phenotype, including prototrophy and growth rate. Furthermore, the unisexual cycle allows attenuated strains to purge deleterious mutations and produce progeny that are returned to wild-type virulence. Our results show that unisexual populations of C. neoformans are able to avoid Muller's ratchet and loss of fitness through a unisexual reproduction cycle involving α-α cell fusion, nuclear fusion, and meiosis. Similar types of unisexual reproduction may operate in other pathogenic and saprobic eukaryotic taxa.

  17. Comparative reproductive biology of elephants.

    PubMed

    Brown, Janine L

    2014-01-01

    The ability to serially collect blood samples and conduct ultrasound examinations in Asian and African elephants has provided unique opportunities to study the biology of these endangered species. As a result, many unique aspects of elephant reproduction have been identified. For females, there are interesting differences in luteal steroidogenic activity, follicular maturation, pituitary gonadotropin secretion, fetal development and reproductive tract anatomy, while males exhibit the unique phenomenon of musth and an unusual reproductive anatomy (internal testes, ampullary semen storage). However, problems associated with uterine and ovarian pathologies hamper captive propagation efforts. Older, nulliparous cows are particularly susceptible, leading to speculation that continuous ovarian cyclicity of non-bred females in zoos is having a negative and cumulative effect on reproductive health. There are notable species differences in reproductive mechanisms as well (e.g., ovarian acyclicity, prolactin secretion, sperm cryosensitivity), implying that species-specific approaches to management and application of assisted reproductive techniques are needed for maximal reproductive efficiency and enhancement of genetic management.

  18. Pleiotropic effects of juvenile hormone in ant queens and the escape from the reproduction-immunocompetence trade-off.

    PubMed

    Pamminger, Tobias; Treanor, David; Hughes, William O H

    2016-01-13

    The ubiquitous trade-off between survival and costly reproduction is one of the most fundamental constraints governing life-history evolution. In numerous animals, gonadotropic hormones antagonistically suppressing immunocompetence cause this trade-off. The queens of many social insects defy the reproduction-survival trade-off, achieving both an extraordinarily long life and high reproductive output, but how they achieve this is unknown. Here we show experimentally, by integrating quantification of gene expression, physiology and behaviour, that the long-lived queens of the ant Lasius niger have escaped the reproduction-immunocompetence trade-off by decoupling the effects of a key endocrine regulator of fertility and immunocompetence in solitary insects, juvenile hormone (JH). This modification of the regulatory architecture enables queens to sustain a high reproductive output without elevated JH titres and suppressed immunocompetence, providing an escape from the reproduction-immunocompetence trade-off that may contribute to the extraordinary lifespan of many social insect queens.

  19. Legal forms and reproductive norms.

    PubMed

    Fletcher, Ruth

    2003-06-01

    This article draws on Pashukanis's concept of legal form and on O'Brien's concept of synthetic value to argue that legal form plays a role in reproductive relations by constructing legal subjects as the bearers of reproductive responsibilities. Pashukanis conceived of legal form as playing a particular role in capitalist exchange relations by interpellating subjects as the bearers of property rights. O'Brien argued that reproduction's specific value is synthetic value, which represents the value of integrating nature and reason in species continuity. Synthetic value is distinct from exchange value or emotional value which may also attach to reproductive process. By working through Pashukanis's method of extracting legal form from specific social relations and by adapting it to reproductive relations, an example is provided of how legal form analysis can be extended beyond the particular context of capitalist exchange relations. Just as legal form constitutes owners and non-owners as legal subjects, so it constitutes reproducers and non-reproducers. By tracing the way in which law attributes reproductive responsibility, legal form analysis shows us how law draws a line between wanting to attribute responsibility and not to attribute it, and this contradiction is a hook which social forces such as sexuality, gender, race, class and disability can latch on to in pushing legal form to shape reproductive responsibilities in a particular way. Each legal form is also externally contradicted by other legal forms. When law negotiates a balance between the reproductive norms of responsibilities and rights, it demonstrates how particular legal forms manage the interaction of different sets of social relations, such as reproduction and exchange. PMID:15871155

  20. The Mahabharata and reproductive endocrinology.

    PubMed

    Kalra, Bharti; Baruah, Manash P; Kalra, Sanjay

    2016-01-01

    This communication approaches the Mahabharata through the prism of reproductive endocrinology. Descriptions of episodes related to reproduction are listed here, to provide fodder for the endocrinologically minded brain. The cases described here are perhaps, the first documented observations of fetal orgasm, pseudocyesis and assisted reproductive technology, including assisted insemination by donor, induction of ovulation, and in vitro fertilization as well as precocious growth and intersex. We do not presume to offer a definite explanation for these interesting episodes from the Mahabharata. We do, however, hope to stimulate interest in ancient Indian literature, and encourage a literary "forensic endocrine" analysis of events relevant to our specialty. PMID:27186562

  1. The Mahabharata and reproductive endocrinology

    PubMed Central

    Kalra, Bharti; Baruah, Manash P.; Kalra, Sanjay

    2016-01-01

    This communication approaches the Mahabharata through the prism of reproductive endocrinology. Descriptions of episodes related to reproduction are listed here, to provide fodder for the endocrinologically minded brain. The cases described here are perhaps, the first documented observations of fetal orgasm, pseudocyesis and assisted reproductive technology, including assisted insemination by donor, induction of ovulation, and in vitro fertilization as well as precocious growth and intersex. We do not presume to offer a definite explanation for these interesting episodes from the Mahabharata. We do, however, hope to stimulate interest in ancient Indian literature, and encourage a literary “forensic endocrine” analysis of events relevant to our specialty. PMID:27186562

  2. Investigating the Fundamental Theorem of Calculus

    ERIC Educational Resources Information Center

    Johnson, Heather L.

    2010-01-01

    The fundamental theorem of calculus, in its simplified complexity, connects differential and integral calculus. The power of the theorem comes not merely from recognizing it as a mathematical fact but from using it as a systematic tool. As a high school calculus teacher, the author developed and taught lessons on this fundamental theorem that were…

  3. Fundamentals of fossil simulator instructor training

    SciTech Connect

    Not Available

    1984-01-01

    This single-volume, looseleaf text introduces the beginning instructor to fundamental instructor training principles, and then shows how to apply those principles to fossil simulator training. Topics include the fundamentals of classroom instruction, the learning process, course development, and the specifics of simulator training program development.

  4. Individual differences in fundamental social motives.

    PubMed

    Neel, Rebecca; Kenrick, Douglas T; White, Andrew Edward; Neuberg, Steven L

    2016-06-01

    Motivation has long been recognized as an important component of how people both differ from, and are similar to, each other. The current research applies the biologically grounded fundamental social motives framework, which assumes that human motivational systems are functionally shaped to manage the major costs and benefits of social life, to understand individual differences in social motives. Using the Fundamental Social Motives Inventory, we explore the relations among the different fundamental social motives of Self-Protection, Disease Avoidance, Affiliation, Status, Mate Seeking, Mate Retention, and Kin Care; the relationships of the fundamental social motives to other individual difference and personality measures including the Big Five personality traits; the extent to which fundamental social motives are linked to recent life experiences; and the extent to which life history variables (e.g., age, sex, childhood environment) predict individual differences in the fundamental social motives. Results suggest that the fundamental social motives are a powerful lens through which to examine individual differences: They are grounded in theory, have explanatory value beyond that of the Big Five personality traits, and vary meaningfully with a number of life history variables. A fundamental social motives approach provides a generative framework for considering the meaning and implications of individual differences in social motivation. (PsycINFO Database Record

  5. Fundamentals of Physics, Problem Supplement No. 1

    NASA Astrophysics Data System (ADS)

    Halliday, David; Resnick, Robert; Walker, Jearl

    2000-05-01

    No other book on the market today can match the success of Halliday, Resnick and Walker's Fundamentals of Physics! In a breezy, easy-to-understand style the book offers a solid understanding of fundamental physics concepts, and helps readers apply this conceptual understanding to quantitative problem solving.

  6. Fundamentals of Physics, 7th Edition

    NASA Astrophysics Data System (ADS)

    Halliday, David; Resnick, Robert; Walker, Jearl

    2004-05-01

    No other book on the market today can match the 30-year success of Halliday, Resnick and Walker's Fundamentals of Physics! In a breezy, easy-to-understand style the book offers a solid understanding of fundamental physics concepts, and helps readers apply this conceptual understanding to quantitative problem solving. This book offers a unique combination of authoritative content and stimulating applications.

  7. Fundamentals of Physics, Student's Solutions Manual

    NASA Astrophysics Data System (ADS)

    Halliday, David; Resnick, Robert; Walker, Jearl

    2000-07-01

    No other book on the market today can match the success of Halliday, Resnick and Walker's Fundamentals of Physics! In a breezy, easy-to-understand style the book offers a solid understanding of fundamental physics concepts, and helps readers apply this conceptual understanding to quantitative problem solving.

  8. Amphibian declines in the twenty-first century: why we need assisted reproductive technologies.

    PubMed

    Clulow, John; Trudeau, Vance L; Kouba, Andrew J

    2014-01-01

    Each amphibian species is evolutionarily distinct, having developed highly specialized and diverse reproductive strategies in both terrestrial and aquatic environments. These unique reproductive patterns and mechanisms, key to species propagation, have only been explored in a limited number of laboratory models. Although the development of applied reproductive technologies for amphibians has proven useful for a few threatened species, the real benefit of this technology has been new insights into the reproductive adaptations, behavior, endocrinology, and physiological mechanisms that have evolved over millions of years. As the basic fundamental database on amphibian reproductive physiology has grown, so has the applied benefit for species conservation. In particular, technologies such as non-invasive fecal and urinary hormone assays, hormone treatments for induced breeding or gamete collection, in vitro fertilization, and the ability to establish genome resource banks have all played important roles in monitoring or managing small populations of captive species. Amphibians have the ability to produce a large excess of germplasm (up to 10,000 ovulated eggs in a single reproductive event) that if not collected and preserved, would represent a wasted valuable resource. We discuss the current state of knowledge in assisted reproductive technologies for amphibians and why their extinction crisis means these available tools can no longer be implemented as small-scale, last-ditch efforts. The reproductive technologies must be established early as a key component of large-scale species recovery.

  9. Genetics and genomics of reproductive performance in dairy and beef cattle.

    PubMed

    Berry, D P; Wall, E; Pryce, J E

    2014-05-01

    Excellent reproductive performance in both males and females is fundamental to profitable dairy and beef production systems. In this review we undertook a meta-analysis of genetic parameters for female reproductive performance across 55 dairy studies or populations and 12 beef studies or populations as well as across 28 different studies or populations for male reproductive performance. A plethora of reproductive phenotypes exist in dairy and beef cattle and a meta-analysis of the literature suggests that most of the female reproductive traits in dairy and beef cattle tend to be lowly heritable (0.02 to 0.04). Reproductive-related phenotypes in male animals (e.g. semen quality) tend to be more heritable than female reproductive phenotypes with mean heritability estimates of between 0.05 and 0.22 for semen-related traits with the exception of scrotal circumference (0.42) and field non-return rate (0.001). The low heritability of reproductive traits, in females in particular, does not however imply that genetic selection cannot alter phenotypic performance as evidenced by the decline until recently in dairy cow reproductive performance attributable in part to aggressive selection for increased milk production. Moreover, the antagonistic genetic correlations among reproductive traits and both milk (dairy cattle) and meat (beef cattle) yield is not unity thereby implying that simultaneous genetic selection for both increased (milk and meat) yield and reproductive performance is indeed possible. The required emphasis on reproductive traits within a breeding goal to halt deterioration will vary based on the underlying assumptions and is discussed using examples for Ireland, the United Kingdom and Australia as well as quantifying the impact on genetic gain for milk production. Advancements in genomic technologies can aid in increasing the accuracy of selection for especially reproductive traits and thus genetic gain. Elucidation of the underlying genomic mechanisms for

  10. Reproductive ethics and the family.

    PubMed

    Nelson, J L

    2000-06-01

    The phrase 'reproductive ethics', as used by bioethicists, typically refers to concerns over morally appropriate employment of assisted reproductive technologies and, perhaps somewhat less commonly, to issues arising from technologies that block conception or end pregnancies. I here recommend to the attention of the field a more commodious use of 'reproductive ethics', one that takes seriously how humans are brought into the world as moral and social beings, and not simply as biological individuals. As a focus for this expanded agenda, I examine prevalent disagreements over the patterns and sources of the responsibilities and prerogatives that help define family structures, both as these are reflected in assisted reproductive practices involving the purchase of gametes, and in U.S. legal controversies about whether parents, or family courts, should determine who has the right to a relationship with children. PMID:15586970

  11. Reproductive ethics and the family.

    PubMed

    Nelson, J L

    2000-06-01

    The phrase 'reproductive ethics', as used by bioethicists, typically refers to concerns over morally appropriate employment of assisted reproductive technologies and, perhaps somewhat less commonly, to issues arising from technologies that block conception or end pregnancies. I here recommend to the attention of the field a more commodious use of 'reproductive ethics', one that takes seriously how humans are brought into the world as moral and social beings, and not simply as biological individuals. As a focus for this expanded agenda, I examine prevalent disagreements over the patterns and sources of the responsibilities and prerogatives that help define family structures, both as these are reflected in assisted reproductive practices involving the purchase of gametes, and in U.S. legal controversies about whether parents, or family courts, should determine who has the right to a relationship with children.

  12. Developing a reproductive life plan.

    PubMed

    Files, Julia A; Frey, Keith A; David, Paru S; Hunt, Katherine S; Noble, Brie N; Mayer, Anita P

    2011-01-01

    The purpose of this article is 2-fold: to emphasize the importance of a reproductive life plan and to define its key elements. We review the 2006 recommendations from the Centers for Disease Control and Prevention (CDC) regarding ways to improve the delivery of preconception health care to women in the United States, with particular focus on encouraging individual reproductive responsibility throughout the life span and on encouraging every woman to develop a reproductive life plan. We propose recommendations for the content of a reproductive life plan and explore ways to incorporate the guidelines from the CDC into clinical practice. By encouraging women to consider their plans for childbearing before they become pregnant, clinicians have the opportunity to influence behavior before pregnancy, which may decrease the incidence of unintended pregnancies and adverse pregnancy outcomes.

  13. BOOK REVIEWS: Quantum Mechanics: Fundamentals

    NASA Astrophysics Data System (ADS)

    Whitaker, A.

    2004-02-01

    mechanics, which is assumed, but to examine whether it gives a consistent account of measurement. The conclusion is that after a measurement, interference terms are ‘effectively’ absent; the set of ‘one-to-one correlations between states of the apparatus and the object’ has the same form as that of everyday statistics and is thus a probability distribution. This probability distribution refers to potentialities, only one of which is actually realized in any one trial. Opinions may differ on whether their treatment is any less vulnerable to criticisms such as those of Bell. To sum up, Gottfried and Yan’s book contains a vast amount of knowledge and understanding. As well as explaining the way in which quantum theory works, it attempts to illuminate fundamental aspects of the theory. A typical example is the ‘fable’ elaborated in Gottfried’s article in Nature cited above, that if Newton were shown Maxwell’s equations and the Lorentz force law, he could deduce the meaning of E and B, but if Maxwell were shown Schrödinger’s equation, he could not deduce the meaning of Psi. For use with a well-constructed course (and, of course, this is the avowed purpose of the book; a useful range of problems is provided for each chapter), or for the relative expert getting to grips with particular aspects of the subject or aiming for a deeper understanding, the book is certainly ideal. It might be suggested, though, that, even compared to the first edition, the isolated learner might find the wide range of topics, and the very large number of mathematical and conceptual techniques, introduced in necessarily limited space, somewhat overwhelming. The second book under consideration, that of Schwabl, contains ‘Advanced’ elements of quantum theory; it is designed for a course following on from one for which Gottfried and Yan, or Schwabl’s own `Quantum Mechanics' might be recommended. It is the second edition in English, and is a translation of the third German edition

  14. Voice and Handgrip Strength Predict Reproductive Success in a Group of Indigenous African Females

    PubMed Central

    Sorokowska, Agnieszka; Sorokowski, Piotr; Mberira, Mara; Bartels, Astrid; Gallup, Gordon G.

    2012-01-01

    Evolutionary accounts of human traits are often based on proxies for genetic fitness (e.g., number of sex partners, facial attractiveness). Instead of using proxies, actual differences in reproductive success is a more direct measure of Darwinian fitness. Certain voice acoustics such as fundamental frequency and measures of health such as handgrip strength correlate with proxies of fitness, yet there are few studies showing the relation of these traits to reproduction. Here, we explore whether the fundamental frequency of the voice and handgrip strength account for differences in actual reproduction among a population of natural fertility humans. Our results show that both fundamental frequency and handgrip strength predict several measures of reproductive success among a group of indigenous Namibian females, particularly amongst the elderly, with weight also predicting reproductive outcomes among males. These findings demonstrate that both hormonally regulated and phenotypic quality markers can be used as measures of Darwinian fitness among humans living under conditions that resemble the evolutionary environment of Homo sapiens. We also argue that these findings provide support for the Grandmother Hypothesis. PMID:22870251

  15. Reproduction Symposium: developmental programming of reproductive and metabolic health.

    PubMed

    Padmanabhan, V; Veiga-Lopez, A

    2014-08-01

    Inappropriate programming of the reproductive system by developmental exposure to excess steroid hormones is of concern. Sheep are well suited for investigating developmental origin of reproductive and metabolic disorders. The developmental time line of female sheep (approximately 5 mo gestation and approximately 7 mo to puberty) is ideal for conducting sequential studies of the progression of metabolic and/or reproductive disruption from the developmental insult to manifestation of adult consequences. Major benefits of using sheep include knowledge of established critical periods to target adult defects, a rich understanding of reproductive neuroendocrine regulation, availability of noninvasive approaches to monitor follicular dynamics, established surgical approaches to obtain hypophyseal portal blood for measurement of hypothalamic hormones, and the ability to perform studies in natural setting thereby keeping behavioral interactions intact. Of importance is the ability to chronically instrument fetus and mother for determining early endocrine perturbations. Prenatal exposure of the female to excess testosterone (T) leads to an array of adult reproductive disorders that include LH excess, functional hyperandrogenism, neuroendocrine defects, multifollicular ovarian morphology, and corpus luteum dysfunction culminating in early reproductive failure. At the neuroendocrine level, all 3 feedback systems are compromised. At the pituitary level, gonadotrope (LH secretion) sensitivity to GnRH is increased. Multifollicular ovarian morphology stems from persistence of follicles as well as enhanced follicular recruitment. These defects culminate in progressive loss of cyclicity and reduced fecundity. Prenatal T excess also leads to fetal growth retardation, an early marker of adult reproductive and metabolic diseases, insulin resistance, hypertension, and behavioral deficits. Collectively, the reproductive and metabolic deficits of prenatal T-treated sheep provide proof of

  16. Hormonal regulation of female reproduction.

    PubMed

    Christensen, A; Bentley, G E; Cabrera, R; Ortega, H H; Perfito, N; Wu, T J; Micevych, P

    2012-07-01

    Reproduction is an event that requires the coordination of peripheral organs with the nervous system to ensure that the internal and external environments are optimal for successful procreation of the species. This is accomplished by the hypothalamic-pituitary-gonadal axis that coordinates reproductive behavior with ovulation. The primary signal from the central nervous system is gonadotropin-releasing hormone (GnRH), which modulates the activity of anterior pituitary gonadotropes regulating follicle stimulating hormone (FSH) and luteinizing hormone (LH) release. As ovarian follicles develop they release estradiol, which negatively regulates further release of GnRH and FSH. As estradiol concentrations peak they trigger the surge release of GnRH, which leads to LH release inducing ovulation. Release of GnRH within the central nervous system helps modulate reproductive behaviors providing a node at which control of reproduction is regulated. To address these issues, this review focuses on several critical questions. How is the HPG axis regulated in species with different reproductive strategies? What internal and external conditions modulate the synthesis and release of GnRH? How does GnRH modulate reproductive behavior within the hypothalamus? How does disease shift the activity of the HPG axis?

  17. Reproductive toxicity of phthalate esters.

    PubMed

    Martino-Andrade, Anderson Joel; Chahoud, Ibrahim

    2010-01-01

    Phthalate esters are ubiquitous environmental contaminants that in general display low-toxicity. Overall, the reproductive effects of these compounds are well characterized in adult's animals, with gonadal injury observed after high dose exposure. However, results of recent transgeneration studies indicate that the reproductive system of developing animals is particularly vulnerable to certain phthalates. The phenotypic alterations observed in male offspring rats exposed during the perinatal period have remarkable similarities with common human reproductive disorders, including cryptorchidism, hypospadias and low-sperm counts. Recent results also indicate that high phthalate doses can adversely affect adult and developing female rats. However, the main question involving phthalates is whether the current level of human exposure is sufficient to adversely affect male and/or female reproductive health. Here, we review the reproductive toxicity data of phthalates in adult and developing animals as well as possible modes of action. In addition, we briefly discuss the relevance of animal studies to humans in light of recent epidemiological data and experimental research with low (human relevant) doses. Finally, we point out some critical issues that should be addressed in order to clarify the implications of phthalates for human reproduction. PMID:19760678

  18. Plant reproduction in spaceflight environments

    NASA Technical Reports Server (NTRS)

    Musgrave, M. E.; Kuang, A.; Porterfield, D. M.

    1997-01-01

    Because plant reproduction is a complex developmental process there are many possible sites of perturbation by the unusual environments of orbital spacecraft. Previous long-duration experiments on Soviet platforms shared features of slowed development through the vegetative stage of plant growth and aborted reproductive function. Our goal has been to understand how special features of the spaceflight environment impact physiological function and reproductive development. In a series of short-duration experiments in the Shuttle mid-deck we studied early reproductive development in Arabidopsis thaliana. Pollen and ovule development aborted at an early stage in the first experiment on STS-54 which utilized closed plant growth chambers. Post-flight analysis suggested that the plants may have been carbon dioxide limited. Subsequent experiments utilized carbon dioxide enrichment (on STS-51) and cabin air flow-through with an air exchange system (on STS-68). Both modifications allowed pollen and ovule development to occur normally on orbit, and full reproductive development up to the stage of an immature seed occurred on STS-68. However, analysis of plant roots from these experiments demonstrated a limitation in rootzone aeration in the spaceflight material that was not mitigated by these procedures. In the future, additional resources (crew time, upgraded flight hardware, and special platforms) will invite more elaborate, long-duration experimentation. On the ISS, a variable speed centrifuge and upgraded plant habitats will permit detailed experiments on the role of gravity in shaping the plant micro-environment, and what influence this plays during reproduction.

  19. From Bacteria to Artificial Cells, the Problem of Self-reproduction

    NASA Astrophysics Data System (ADS)

    Libchaber, Albert

    Self-reproduction, the production of an offspring identical with the parent, is a fundamental conceptual problem. We first present the historical evolution of the concept "What are structures which produce further identical structures." We then describe the state and development of an artificial cell project, and its feasibility to self-reproduce...

  20. [HIV and reproductive choices].

    PubMed

    Boer, K; de Vries, J W; de Beaufort, I E

    1995-05-13

    It is estimated that there are about 120-150 hemophilic men infected with HIV in the Netherlands as well as 1000 men infected via intravenous drug use. The majority of them are in reproductive age with relationships with seronegative women. In the event they want to have a child, artificial insemination with donor sperm (KID) is an option. In 1994 there were 147 instances of insemination of 66 women with the processed semen of HIV-positive men and no infection resulted. The annual risk of HIV infection was 7.2% of a woman engaging in unprotected intercourse, according to a prospective Italian study. The risk of HIV infection per contact was estimated at 0.1-5.6%. However, it is not yet proven that processed sperm of an HIV-seropositive man can produce a pregnancy without the risk of infecting the woman. The risk of transmission of HIV to the fetus is higher in artificial insemination of a seropositive woman with the sperm of her partner. In vitro fertilization is not a sure method either for the prevention of HIV infection of the mother because of the possibility of an egg cell being infected before fertilization. HIV-infected pregnant women face the problems of caring for HIV-infected offspring. For HIV discordant couples the advice is to use both condoms for the prevention of infection and oral contraceptives for the prevention of pregnancy. In the case of a lesbian relationship, if the partners want to have a child, HIV infection is still a factor because of previous heterosexual contacts.

  1. Rotor-Liquid-Fundament System's Oscillation

    NASA Astrophysics Data System (ADS)

    Kydyrbekuly, A.

    The work is devoted to research of oscillation and sustainability of stationary twirl of vertical flexible static dynamically out-of-balance rotor with cavity partly filled with liquid and set on relative frame fundament. The accounting of such factors like oscillation of fundament, liquid oscillation, influence of asymmetry of installation of a rotor on a shaft, anisotropism of shaft support and fundament, static and dynamic out-of-balance of a rotor, an external friction, an internal friction of a shaft, allows to settle an invoice more precisely kinematic and dynamic characteristics of system.

  2. Reproductive cycles of buffalo.

    PubMed

    Perera, B M A O

    2011-04-01

    The domestic water buffalo (Bubalus bubalis) has an important role in the agricultural economy of many developing countries in Asia, providing milk, meat and draught power. It is also used in some Mediterranean and Latin American countries as a source of milk and meat for specialized markets. Although the buffalo can adapt to harsh environments and live on poor quality forage, reproductive efficiency is often compromised by such conditions, resulting in late sexual maturity, long postpartum anoestrus, poor expression of oestrus, poor conception rates and long calving intervals. The age at puberty is influenced by genotype, nutrition, management and climate, and under favourable conditions occurs at 15-18 months in river buffalo and 21-24 months in swamp buffalo. The ovaries are smaller than in cattle and contain fewer primordial follicles. Buffalo are capable of breeding throughout the year, but in many countries a seasonal pattern of ovarian activity occurs. This is attributed in tropical regions to changes in rainfall resulting in feed availability or to temperature stress resulting in elevated prolactin secretion, and in temperate regions to changes in photoperiod and melatonin secretion. The mean length of the oestrous cycle is 21 days, with greater variation than observed in cattle. The signs of oestrus in buffalo are less overt than in cattle and homosexual behaviour between females is rare. The duration of oestrus is 5-27 h, with ovulation occurring 24-48 h (mean 34 h) after the onset of oestrus. The hormonal changes occurring in peripheral circulation are similar to those observed in cattle, but the peak concentrations of progesterone and oestradiol-17β are less. The number of follicular waves during an oestrous cycle varies from one to three and influences the length of the luteal phase as well as the inter-ovulatory interval. Under optimal conditions, dairy types managed with limited or no suckling resume oestrus cyclicity by 30-60 days after calving

  3. Reproductive cycles of buffalo.

    PubMed

    Perera, B M A O

    2011-04-01

    The domestic water buffalo (Bubalus bubalis) has an important role in the agricultural economy of many developing countries in Asia, providing milk, meat and draught power. It is also used in some Mediterranean and Latin American countries as a source of milk and meat for specialized markets. Although the buffalo can adapt to harsh environments and live on poor quality forage, reproductive efficiency is often compromised by such conditions, resulting in late sexual maturity, long postpartum anoestrus, poor expression of oestrus, poor conception rates and long calving intervals. The age at puberty is influenced by genotype, nutrition, management and climate, and under favourable conditions occurs at 15-18 months in river buffalo and 21-24 months in swamp buffalo. The ovaries are smaller than in cattle and contain fewer primordial follicles. Buffalo are capable of breeding throughout the year, but in many countries a seasonal pattern of ovarian activity occurs. This is attributed in tropical regions to changes in rainfall resulting in feed availability or to temperature stress resulting in elevated prolactin secretion, and in temperate regions to changes in photoperiod and melatonin secretion. The mean length of the oestrous cycle is 21 days, with greater variation than observed in cattle. The signs of oestrus in buffalo are less overt than in cattle and homosexual behaviour between females is rare. The duration of oestrus is 5-27 h, with ovulation occurring 24-48 h (mean 34 h) after the onset of oestrus. The hormonal changes occurring in peripheral circulation are similar to those observed in cattle, but the peak concentrations of progesterone and oestradiol-17β are less. The number of follicular waves during an oestrous cycle varies from one to three and influences the length of the luteal phase as well as the inter-ovulatory interval. Under optimal conditions, dairy types managed with limited or no suckling resume oestrus cyclicity by 30-60 days after calving

  4. Striking a balance: conscientious objection and reproductive health care from the Colombian perspective.

    PubMed

    Cabal, Luisa; Olaya, Monica Arango; Robledo, Valentina Montoya

    2014-12-11

    Conscientious Objection or conscientious refusal (CO) in access to reproductive health care is at the center of current legal debates worldwide. In countries such as the US and the UK, constitutional dilemmas surrounding CO in the context of reproductive health services reveal inadequate policy frameworks for balancing CO rights with women's rights to access contraception and abortion. The Colombian Constitutional Court's holistic jurisprudence regarding CO standards has applied international human rights norms so as to not only protect women's reproductive rights as fundamental rights, but to also introduce clear limits for the exercise of CO in health care settings. This paper reviews Latin American lines of regulation in Argentina, Uruguay, and Mexico City to argue that the Colombian Court's jurisprudence offers a strong guidance for future comprehensive policy approaches that aim to effectively balance tensions between CO and women's reproductive rights.

  5. Reproduction in the space environment: Part I. Animal reproductive studies

    NASA Technical Reports Server (NTRS)

    Santy, P. A.; Jennings, R. T.; Craigie, D.

    1990-01-01

    Mankind's exploration and colonization of the frontier of space will ultimately depend on men's and women's ability to live, work, and reproduce in the space environment. This paper reviews animal studies, from microorganisms to mammals, done in space or under space-simulated conditions, which identify some of the key areas which might interfere with human reproductive physiology and/or embryonic development. Those space environmental factors which impacted almost all species included: microgravity, artificial gravity, radiation, and closed life support systems. These factors may act independently and in combination to produce their effects. To date, there have been no studies which have looked at the entire process of reproduction in any animal species. This type of investigation will be critical in understanding and preventing the problems which will affect human reproduction. Part II will discuss these problems directly as they relate to human physiology.

  6. Free radicals and male reproduction.

    PubMed

    Agarwal, Ashok; Allamaneni, Shyam S R

    2011-03-01

    Male factor accounts for almost 50% cases of infertility. The exact mechanism of sperm dysfunction is not known in many cases. Extensive research in the last decade has led to the identification of free radicals (reactive oxygen species) as mediators of sperm dysfunction in both specific diagnoses and idiopathic cases of male infertility. Elevated levels of reactive oxygen species are seen in up to 30-80% of men with male infertility. The role of free radicals has been studied extensively in the process of human reproduction. We know now that a certain level of free radicals is necessary for normal sperm function, whereas an excessive level of free radicals can cause detrimental effect on sperm function and subsequent fertilisation and offspring health. Oxidative stress develops when there is an imbalance between generation of free radicals and scavenging capacity of anti-oxidants in reproductive tract. Oxidative stress has been shown to affect both standard semen parameters and fertilising capacity. In addition, high levels of free radicals have been associated with lack of or poor fertility outcome after natural conception or assisted reproduction. Diagnostic techniques to quantify free radicals in infertile patients can assist physicians treating patients with infertility to plan for proper treatment strategies. In vivo anti-oxidants can be used against oxidative stress in male reproductive tract. Supplementation of in vitro anti-oxidants can help prevent the oxidative stress during sperm preparation techniques in assisted reproduction.

  7. [Public health ethics and reproduction].

    PubMed

    Alexandrova-Yankulovska, S; Bozhinov, P; Bojinova, S

    2014-01-01

    Medical progress has enabled achievements that were not even thinkable earlier but at the same time society and public health have had to face new challenges. What are we ready to accept in the area of human reproduction? This paper aims at ethical analysis of Bulgarian laws on reproduction. The abortion debate nowadays has got new dimiension focusing not that much on its moral acceptability but rather on the acceptable indications for its performance. Is it ethical to perform abortion in case of undesired gender of the embryo or genetic malformations? Lots of moral issues mark the area of assisted reproduction which is due to the separation of the reproductive functions (ova, sperm and embryo donation, surrogacy), fragmentation of motherhood and fatherhood, differentiation of biological and social parenthood. Defining limits of acceptable interference or non-interference in human reproduction will never be easy, but dynamics of moral judgment shouldn't bother us. The rigidity of moral norms is what should be alarming because it threatens procreative autonomy. PMID:24919342

  8. Male participation in reproductive health.

    PubMed

    Robey, B; Drennan, M

    1998-01-01

    Family planning programs (FPPs) have traditionally viewed women as their main clients because it is women who become pregnant, most contraceptive methods are designed for women, and reproductive health services can be conveniently offered as part of maternal and child health services. Some FPPs have avoided serving men because they believe that women need privacy and autonomy in reproductive health matters. However, this assumption that men are not interested in taking responsibility for family planning has become a self-fulfilling prophecy. FPPs have made little effort to consider men's reproductive health needs or to reach out to men. As such, men have few contacts with the reproductive health care system. Recent survey and study findings instead suggest that many men are highly interested in family planning and other reproductive health issues, and would participate in family planning if given the chance. While some family planning programs have been interested in involving men for more than a decade, men's participation has only recently become the focus of considerable attention. One reason for this newly directed focus is growing concern over the rapid spread of HIV and the targeting of HIV prevention programs upon both men and women to an almost equal extent.

  9. [Public health ethics and reproduction].

    PubMed

    Alexandrova-Yankulovska, S; Bozhinov, P; Bojinova, S

    2014-01-01

    Medical progress has enabled achievements that were not even thinkable earlier but at the same time society and public health have had to face new challenges. What are we ready to accept in the area of human reproduction? This paper aims at ethical analysis of Bulgarian laws on reproduction. The abortion debate nowadays has got new dimiension focusing not that much on its moral acceptability but rather on the acceptable indications for its performance. Is it ethical to perform abortion in case of undesired gender of the embryo or genetic malformations? Lots of moral issues mark the area of assisted reproduction which is due to the separation of the reproductive functions (ova, sperm and embryo donation, surrogacy), fragmentation of motherhood and fatherhood, differentiation of biological and social parenthood. Defining limits of acceptable interference or non-interference in human reproduction will never be easy, but dynamics of moral judgment shouldn't bother us. The rigidity of moral norms is what should be alarming because it threatens procreative autonomy.

  10. Chemosignals, hormones, and amphibian reproduction.

    PubMed

    Woodley, Sarah

    2015-02-01

    This article is part of a Special Issue "Chemosignals and Reproduction". Amphibians are often thought of as relatively simple animals especially when compared to mammals. Yet the chemosignaling systems used by amphibians are varied and complex. Amphibian chemosignals are particularly important in reproduction, in both aquatic and terrestrial environments. Chemosignaling is most evident in salamanders and newts, but increasing evidence indicates that chemical communication facilitates reproduction in frogs and toads as well. Reproductive hormones shape the production, dissemination, detection, and responsiveness to chemosignals. A large variety of chemosignals have been identified, ranging from simple, invariant chemosignals to complex, variable blends of chemosignals. Although some chemosignals elicit straightforward responses, others have relatively subtle effects. Review of amphibian chemosignaling reveals a number of issues to be resolved, including: 1) the significance of the complex, individually variable blends of courtship chemosignals found in some salamanders, 2) the behavioral and/or physiological functions of chemosignals found in anuran "breeding glands", 3) the ligands for amphibian V2Rs, especially V2Rs expressed in the main olfactory epithelium, and 4) the mechanism whereby transdermal delivery of chemosignals influences behavior. To date, only a handful of the more than 7000 species of amphibians has been examined. Further study of amphibians should provide additional insight to the role of chemosignals in reproduction.

  11. Unisexual reproduction in Huntiella moniliformis.

    PubMed

    Wilson, A M; Godlonton, T; van der Nest, M A; Wilken, P M; Wingfield, M J; Wingfield, B D

    2015-07-01

    Sexual reproduction in fungi is controlled by genes present at the mating type (MAT) locus, which typically harbors transcription factors that influence the expression of many sex-related genes. The MAT locus exists as two alternative idiomorphs in ascomycetous fungi and sexual reproduction is initiated when genes from both idiomorphs are expressed. Thus, the gene content of this locus determines whether a fungus is heterothallic (self-sterile) or homothallic (self-fertile). Recently, a unique sub-class of homothallism has been described in fungi, where individuals possessing a single MAT idiomorph can reproduce sexually in the absence of a partner. Using various mycological, molecular and bioinformatic techniques, we investigated the sexual strategies and characterized the MAT loci in two tree wound-infecting fungi, Huntiella moniliformis and Huntiella omanensis. H. omanensis was shown to exhibit a typically heterothallic sexual reproductive cycle, with isolates possessing either the MAT1-1 or MAT1-2 idiomorph. This was in contrast to the homothallism via unisexual reproduction that was shown in H. moniliformis, where only the MAT1-2-1 gene was present in sexually reproducing cultures. While the evolutionary benefit and mechanisms underpinning a unisexual mating strategy remain unknown, it could have evolved to minimize the costs, while retaining the benefits, of normal sexual reproduction.

  12. Histopathology of the male reproductive system II: interpretation.

    PubMed

    Creasy, Dianne M

    2002-11-01

    Histopathology is acknowledged as the most sensitive endpoint for detecting testicular toxicity. However, identification and interpretation of chemically induced changes in the testis require fundamental knowledge of spermatogenesis, its dynamics and regulation. Changes in the rest of the reproductive tract are also frequently inter-related, being the result of or cause of disturbance in testicular spermatogenesis. This unit provides practical guidelines on how to evaluate testicular histopathology and how to utilize staging in a qualitative evaluation. It also provides an overview of the most common chemically induced lesions and their potential significance with respect to etiology and functional consequences.

  13. Practice and evaluation of ethical governance in assisted reproductive technologies.

    PubMed

    Tu, Ling; He, Jing; Lu, Guang-xiu

    2008-12-01

    The rapid development of assisted reproductive technologies (ART) raises complex ethical and social problems. This article explores how to perform ethical governance in ART and evaluates the social consequences. In order to urge doctors and patients to abide by medical ethics and moral norms and to ensure the successful development of ART, we argue that ethics committees must be robust and that their guidelines must be followed. Specifically, it is necessary to improve awareness of the fundamentals of ART and related ethical principles among doctors and patients. This includes the need to intensify mechanisms to fully monitor the implementation and enforcement of medical ethical principles and doctrines, such as informed consent. PMID:19492723

  14. Macroevolutionary speciation rates are decoupled from the evolution of intrinsic reproductive isolation in Drosophila and birds.

    PubMed

    Rabosky, Daniel L; Matute, Daniel R

    2013-09-17

    The rate at which speciation occurs varies greatly among different kinds of organisms and is frequently assumed to result from species- or clade-specific factors that influence the rate at which populations acquire reproductive isolation. This premise leads to a fundamental prediction that has never been tested: Organisms that quickly evolve prezygotic or postzygotic reproductive isolation should have faster rates of speciation than organisms that slowly acquire reproductive isolation. We combined phylogenetic estimates of speciation rates from Drosophila and birds with a method for analyzing interspecific hybridization data to test whether the rate at which individual lineages evolve reproductive isolation predicts their macroevolutionary rate of species formation. We find that some lineages evolve reproductive isolation much more quickly than others, but this variation is decoupled from rates of speciation as measured on phylogenetic trees. For the clades examined here, reproductive isolation--especially intrinsic, postzygotic isolation--does not seem to be the rate-limiting control on macroevolutionary diversification dynamics. These results suggest that factors associated with intrinsic reproductive isolation may have less to do with the tremendous variation in species diversity across the evolutionary tree of life than is generally assumed.

  15. Impacts of early life exposure to estrogen on subsequent breeding behavior and reproductive success in zebrafish.

    PubMed

    Coe, Tobias S; Söffker, Marta K; Filby, Amy L; Hodgson, David; Tyler, Charles R

    2010-08-15

    Impacts of exposure to environmental estrogens on reproductive development are well documented, but recently wider concern has been raised due to evidence that such exposures can disrupt normal patterns of reproductive behavior, dominance, and parentage, with potential population level implications. It is fundamental therefore to understand any such effects for effective risk assessment. This study investigated the impact of a transient exposure to ethinylestradiol (EE(2)) during early life (from 20-60 days post fertilization), including at a dosing level within the environmental range, on the subsequent reproductive behavior and success in both male and female zebrafish (Danio rerio) in competitive breeding scenarios. There were no obvious effects of the early life EE(2) exposures on the subsequent gonadal phenotypes in either mature males or females. In fact, reproductive success in males exposed to 2.76 ng EE(2)/L was increased in competitive spawning scenarios. In contrast, exposure of females to EE(2) (9.86 ng/L) during early life reduced their subsequent reproductive success in competitive spawning scenarios. Mate choice experiments suggested this was a consequence of the females' diminished courting behavior toward males, rather than any male preference for unexposed females. Reproductive capability of females is generally considered a key determinant in population demographics and dynamics, and therefore the effect of exposure to EE(2) on female reproductive success may have significant implications for exposed fish populations.

  16. Bioenergetic components of reproductive effort in viviparous snakes: costs of vitellogenesis exceed costs of pregnancy.

    PubMed

    Van Dyke, James U; Beaupre, Steven J

    2011-12-01

    Reproductive effort has been defined as the proportion of an organism's energy budget that is allocated to reproduction over a biologically meaningful time period. Historically, studies of reproductive bioenergetics considered energy content of gametes, but not costs of gamete production. Although metabolic costs of vitellogenesis (MCV) fundamentally reflect the primary bioenergetic cost of reproductive allocation in female reptiles, the few investigations that have considered costs of reproductive allocation have focused on metabolic costs of pregnancy (MCP) in viviparous species. We define MCP as energetic costs incurred by pregnant females, including all costs of maintaining gestation conditions necessary for embryogenesis. MCP by our definition do not include fetal costs of embryogenesis. We measured metabolic rates in five species of viviparous snakes (Agkistrodon contortrix, Boa constrictor, Eryx colubrinus, Nerodia sipedon, and Thamnophis sirtalis) during vitellogenesis and pregnancy in order to estimate MCV and MCP. Across all species, MCV were responsible for 30% increases in maternal metabolism. Phylogenetically-independent contrasts showed that MCV were significantly greater in B. constrictor than in other species, likely because B. constrictor yolk energy content was greater than that of other species. Estimates of MCP were not significantly different from zero in any species. In viviparous snakes, MCV appear to represent significant bioenergetic expenditures, while MCP do not. We suggest that MCV, together with yolk energy content, represent the most significant component of reptilian reproductive effort, and therefore deserve greater attention than MCP in studies of reptilian reproductive bioenergetics.

  17. Maternal characteristics and environment affect the costs of reproduction in female mountain goats.

    PubMed

    Hamel, Sandra; Côté, Steeve D; Festa-Bianchet, Marco

    2010-07-01

    Reproduction should reduce resources available for somatic investment and result in fundamental trade-offs among life-history traits. Using 18 years of longitudinal data from marked mountain goats (Oreamnos americanus), we assessed whether reproductive status affected female survival and future reproduction when accounting for parity, age, individual quality, population density, and environmental conditions. Reproduction reduced the probability of parturition and offspring survival in the following year. Female survival, however, was independent of previous reproduction, suggesting that females favored their own survival over that of their offspring. The lower probability of parturition in females that had a kid the previous year was only detected at high population density and among young and prime-aged females, suggesting that fitness costs of reproduction can be masked by variations in resource availability and individual characteristics. Primiparous females were less likely than multiparous females to reproduce in the subsequent year. Offspring survival was reduced at high density and after severe winters. Environmental conditions mainly influenced offspring survival, whereas female survival and fecundity were principally modulated by female characteristics. Our study highlights how different intrinsic and environmental factors can affect the probability of future reproduction and also underlines the value of long-term monitoring of known individuals. PMID:20715626

  18. Nutritional effects on reproductive performance of captive adult female coyotes (Canis latrans).

    PubMed

    Gese, Eric M; Roberts, Beth M; Knowlton, Frederick F

    2016-02-01

    Interactions between animals and their environment are fundamental to ecological research. Field studies of coyote (Canis latrans) reproductive performance suggest mean litter size changes in response to prey abundance. However, this relationship has been assessed primarily by using carcasses collected from trappers. The objective of this study was to assess whether nutritional manipulation prior to mating affected reproduction in adult female coyotes. We examined the effects of caloric restriction during the 7 months prior to estrus on the reproductive rates of 11 captive female coyotes and the subsequent initial survival of pups through two reproductive cycles. This was a 2-year study with a cross-over design so each female was monitored for reproductive performance on each of the two diet treatments. We assessed the number of implantation scars, number of pups born, sex ratios of pups, average pup weight at birth and 2- and 6-weeks of age, and the survival rates between implantation and 2-weeks of age for two diet treatments. We found the mean number of implantation sites and pups whelped during a reproductive cycle was influenced by food-intake prior to conception. Additionally, we found evidence suggesting the effects of nutritional stress may persist for additional breeding cycles. We also provided evidence suggesting well-fed females tended to have more male pups. Understanding how environmental factors influence reproductive output may improve model predictions of coyote population dynamics.

  19. Macroevolutionary speciation rates are decoupled from the evolution of intrinsic reproductive isolation in Drosophila and birds

    PubMed Central

    Rabosky, Daniel L.; Matute, Daniel R.

    2013-01-01

    The rate at which speciation occurs varies greatly among different kinds of organisms and is frequently assumed to result from species- or clade-specific factors that influence the rate at which populations acquire reproductive isolation. This premise leads to a fundamental prediction that has never been tested: Organisms that quickly evolve prezygotic or postzygotic reproductive isolation should have faster rates of speciation than organisms that slowly acquire reproductive isolation. We combined phylogenetic estimates of speciation rates from Drosophila and birds with a method for analyzing interspecific hybridization data to test whether the rate at which individual lineages evolve reproductive isolation predicts their macroevolutionary rate of species formation. We find that some lineages evolve reproductive isolation much more quickly than others, but this variation is decoupled from rates of speciation as measured on phylogenetic trees. For the clades examined here, reproductive isolation—especially intrinsic, postzygotic isolation—does not seem to be the rate-limiting control on macroevolutionary diversification dynamics. These results suggest that factors associated with intrinsic reproductive isolation may have less to do with the tremendous variation in species diversity across the evolutionary tree of life than is generally assumed. PMID:24003144

  20. Maternal characteristics and environment affect the costs of reproduction in female mountain goats.

    PubMed

    Hamel, Sandra; Côté, Steeve D; Festa-Bianchet, Marco

    2010-07-01

    Reproduction should reduce resources available for somatic investment and result in fundamental trade-offs among life-history traits. Using 18 years of longitudinal data from marked mountain goats (Oreamnos americanus), we assessed whether reproductive status affected female survival and future reproduction when accounting for parity, age, individual quality, population density, and environmental conditions. Reproduction reduced the probability of parturition and offspring survival in the following year. Female survival, however, was independent of previous reproduction, suggesting that females favored their own survival over that of their offspring. The lower probability of parturition in females that had a kid the previous year was only detected at high population density and among young and prime-aged females, suggesting that fitness costs of reproduction can be masked by variations in resource availability and individual characteristics. Primiparous females were less likely than multiparous females to reproduce in the subsequent year. Offspring survival was reduced at high density and after severe winters. Environmental conditions mainly influenced offspring survival, whereas female survival and fecundity were principally modulated by female characteristics. Our study highlights how different intrinsic and environmental factors can affect the probability of future reproduction and also underlines the value of long-term monitoring of known individuals.

  1. Nutritional effects on reproductive performance of captive adult female coyotes (Canis latrans).

    PubMed

    Gese, Eric M; Roberts, Beth M; Knowlton, Frederick F

    2016-02-01

    Interactions between animals and their environment are fundamental to ecological research. Field studies of coyote (Canis latrans) reproductive performance suggest mean litter size changes in response to prey abundance. However, this relationship has been assessed primarily by using carcasses collected from trappers. The objective of this study was to assess whether nutritional manipulation prior to mating affected reproduction in adult female coyotes. We examined the effects of caloric restriction during the 7 months prior to estrus on the reproductive rates of 11 captive female coyotes and the subsequent initial survival of pups through two reproductive cycles. This was a 2-year study with a cross-over design so each female was monitored for reproductive performance on each of the two diet treatments. We assessed the number of implantation scars, number of pups born, sex ratios of pups, average pup weight at birth and 2- and 6-weeks of age, and the survival rates between implantation and 2-weeks of age for two diet treatments. We found the mean number of implantation sites and pups whelped during a reproductive cycle was influenced by food-intake prior to conception. Additionally, we found evidence suggesting the effects of nutritional stress may persist for additional breeding cycles. We also provided evidence suggesting well-fed females tended to have more male pups. Understanding how environmental factors influence reproductive output may improve model predictions of coyote population dynamics. PMID:26763531

  2. Size-dependent reproductive pattern and short-term reproductive cost in Rumex obtusifolius L

    NASA Astrophysics Data System (ADS)

    Pino, Joan; Sans, F. Xavier; Masalles, Ramon M.

    2002-10-01

    This paper analyses the size-dependent reproductive pattern of Rumex obtusifolius L. growing in lucerne crops ( Medicago sativa L.), and its importance in determining the existence of a short-term reproductive cost. Size effects on reproductive pattern were evaluated by determining the role of plant size at the time of first reproduction, and the size-dependency of flowering probability (estimated as the proportion of flowering plants), plant fecundity, and reproductive effort (estimated as the ratio between reproductive and vegetative biomass). These parameters were recorded over the reproductive episodes determined by crop harvesting during the reproductive period. The results showed that size was much more important than age in determining time of first reproduction. Seed output decreased progressively over the reproductive period, probably in relation to an increasing short-term reproductive cost caused by a gradual depletion of plant resources. Probability of flowering over the successive reproductive episodes increased with plant size. The allometric relationship of vegetative versus reproductive biomass indicated that reproductive biomass increased less sharply than vegetative biomass and, consequently, reproductive effort decreased as plant size increased. Assuming a direct relationship between reproductive effort and reproductive cost, the size-dependent flowering probability could reflect, in turn, the existence of a size-dependent reproductive cost that would decrease as plant size increased. Ecological implications of these results are discussed.

  3. The ageing male reproductive tract.

    PubMed

    Sampson, N; Untergasser, G; Plas, E; Berger, P

    2007-01-01

    Ageing of the male reproductive system is characterized by changes in the endocrine system, hypogonadism, erectile dysfunction and proliferative disorders of the prostate gland. Stochastic damage accumulating within ageing leads to progressive dysregulation at each level of the hypothalamic-pituitary-gonadal (HPG) axis and in local auto/paracrine interactions, thereby inducing morphological changes in reproductive target organs, such as the prostate, testis and penis. Despite age-related changes in the HPG axis, endocrine functions are generally sufficient to maintain fertility in elderly men. Ageing of the male reproductive system can give rise to clinically relevant manifestations, such as benign prostatic hyperplasia (BPH), prostate cancer (PCa) and erectile dysfunction (ED). In this review, we discuss morphological/histological changes occurring in these organs and current views and concepts of the underlying pathology. Moreover, we emphasize the molecular/cellular pathways leading to reduced testicular/penile function and proliferative disorders of the prostate gland.

  4. Reproductive cycles of marine mammals.

    PubMed

    Pomeroy, P

    2011-04-01

    Marine mammals conform to the general mammalian reproductive system centered on the hypothalamic-pituitary-gonadal axis. Most marine mammals are long-lived and of large body size with lesser reproductive rates than many other animals, a consequence of their interaction with the marine environment where the demands of acquiring resources from the ocean must be balanced with the need for bearing offspring in a suitable place for survival. The degree of spatial and temporal separation of these life history phases in many species is a key feature of their ecology. The reproductive physiology of pinnipeds, cetaceans, sirenians, sea otters and polar bears has been more thoroughly characterized for the more accessible species.

  5. Therapeutic cloning and reproductive liberty.

    PubMed

    Sparrow, Robert

    2009-04-01

    Concern for "reproductive liberty" suggests that decisions about embryos should normally be made by the persons who would be the genetic parents of the child that would be brought into existence if the embryo were brought to term. Therapeutic cloning would involve creating and destroying an embryo, which, if brought to term, would be the offspring of the genetic parents of the person undergoing therapy. I argue that central arguments in debates about parenthood and genetics therefore suggest that therapeutic cloning would be prima facie unethical unless it occurred with the consent of the parents of the person being cloned. Alternatively, if therapeutic cloning is thought to be legitimate, this undermines the case for some uses of reproductive cloning by implying that the genetic relation it establishes between clones and DNA donors does not carry the same moral weight as it does in cases of normal reproduction.

  6. Reproduction is not costly in terms of oxidative stress.

    PubMed

    Ołdakowski, Łukasz; Wasiluk, Aleksandra; Sadowska, Edyta T; Koteja, Paweł; Taylor, Jan R E

    2015-12-01

    One of the core assumptions of life-history theory is the negative trade-off between current and future reproduction. Investment in current reproduction is expected to decrease future reproductive success or survival, but the physiological mechanisms underlying these costs are still obscure. To test for a role of oxidative stress, we measured oxidative damage to lipids and proteins in liver, heart, kidneys and muscles, as well as the level of antioxidants (total glutathione and catalase), in breeding and non-breeding bank voles. We used females from lines selected for high aerobic metabolism and non-selected control lines and manipulated their reproductive investment by decreasing or increasing litter size. Unlike in most previous studies, the females reared four consecutive litters (the maximum possible during a breeding season). Contrary to predictions, oxidative damage in reproducing females was decreased or not changed, and did not differ between the selected and control lines. Oxidative damage to lipids and proteins in the liver was lower in females that weaned enlarged litters than in non-breeding ones, and was intermediate in those with reduced litters. Oxidative damage to proteins in the heart also tended to be lower in breeding females than in non-breeding ones. A negative relationship between the level of oxidative damage and activity of catalase in kidneys indicated a protective action of antioxidants. In conclusion, our study falsified the hypothesis that oxidative stress is a part of the proximate physiological mechanism underlying the fundamental life-history trade-off between current and future reproduction. PMID:26519508

  7. Coral reproduction in Western Australia.

    PubMed

    Gilmour, James; Speed, Conrad W; Babcock, Russ

    2016-01-01

    Larval production and recruitment underpin the maintenance of coral populations, but these early life history stages are vulnerable to extreme variation in physical conditions. Environmental managers aim to minimise human impacts during significant periods of larval production and recruitment on reefs, but doing so requires knowledge of the modes and timing of coral reproduction. Most corals are hermaphroditic or gonochoric, with a brooding or broadcast spawning mode of reproduction. Brooding corals are a significant component of some reefs and produce larvae over consecutive months. Broadcast spawning corals are more common and display considerable variation in their patterns of spawning among reefs. Highly synchronous spawning can occur on reefs around Australia, particularly on the Great Barrier Reef. On Australia's remote north-west coast there have been fewer studies of coral reproduction. The recent industrial expansion into these regions has facilitated research, but the associated data are often contained within confidential reports. Here we combine information in this grey-literature with that available publicly to update our knowledge of coral reproduction in WA, for tens of thousands of corals and hundreds of species from over a dozen reefs spanning 20° of latitude. We identified broad patterns in coral reproduction, but more detailed insights were hindered by biased sampling; most studies focused on species of Acropora sampled over a few months at several reefs. Within the existing data, there was a latitudinal gradient in spawning activity among seasons, with mass spawning during autumn occurring on all reefs (but the temperate south-west). Participation in a smaller, multi-specific spawning during spring decreased from approximately one quarter of corals on the Kimberley Oceanic reefs to little participation at Ningaloo. Within these seasons, spawning was concentrated in March and/or April, and October and/or November, depending on the timing of the

  8. Coral reproduction in Western Australia.

    PubMed

    Gilmour, James; Speed, Conrad W; Babcock, Russ

    2016-01-01

    Larval production and recruitment underpin the maintenance of coral populations, but these early life history stages are vulnerable to extreme variation in physical conditions. Environmental managers aim to minimise human impacts during significant periods of larval production and recruitment on reefs, but doing so requires knowledge of the modes and timing of coral reproduction. Most corals are hermaphroditic or gonochoric, with a brooding or broadcast spawning mode of reproduction. Brooding corals are a significant component of some reefs and produce larvae over consecutive months. Broadcast spawning corals are more common and display considerable variation in their patterns of spawning among reefs. Highly synchronous spawning can occur on reefs around Australia, particularly on the Great Barrier Reef. On Australia's remote north-west coast there have been fewer studies of coral reproduction. The recent industrial expansion into these regions has facilitated research, but the associated data are often contained within confidential reports. Here we combine information in this grey-literature with that available publicly to update our knowledge of coral reproduction in WA, for tens of thousands of corals and hundreds of species from over a dozen reefs spanning 20° of latitude. We identified broad patterns in coral reproduction, but more detailed insights were hindered by biased sampling; most studies focused on species of Acropora sampled over a few months at several reefs. Within the existing data, there was a latitudinal gradient in spawning activity among seasons, with mass spawning during autumn occurring on all reefs (but the temperate south-west). Participation in a smaller, multi-specific spawning during spring decreased from approximately one quarter of corals on the Kimberley Oceanic reefs to little participation at Ningaloo. Within these seasons, spawning was concentrated in March and/or April, and October and/or November, depending on the timing of the

  9. Ionizing radiation promotes protozoan reproduction

    SciTech Connect

    Luckey, T.D.

    1986-11-01

    This experiment was performed to determine whether ionizing radiation is essential for maximum growth rate in a ciliated protozoan. When extraneous ionizing radiation was reduced to 0.15 mrad/day, the reproduction rate of Tetrahymena pyriformis was significantly less (P less than 0.01) than it was at near ambient levels, 0.5 or 1.8 mrad/day. Significantly higher growth rates (P less than 0.01) were obtained when chronic radiation was increased. The data suggest that ionizing radiation is essential for optimum reproduction rate in this organism.

  10. Coral reproduction in Western Australia

    PubMed Central

    Speed, Conrad W.; Babcock, Russ

    2016-01-01

    Larval production and recruitment underpin the maintenance of coral populations, but these early life history stages are vulnerable to extreme variation in physical conditions. Environmental managers aim to minimise human impacts during significant periods of larval production and recruitment on reefs, but doing so requires knowledge of the modes and timing of coral reproduction. Most corals are hermaphroditic or gonochoric, with a brooding or broadcast spawning mode of reproduction. Brooding corals are a significant component of some reefs and produce larvae over consecutive months. Broadcast spawning corals are more common and display considerable variation in their patterns of spawning among reefs. Highly synchronous spawning can occur on reefs around Australia, particularly on the Great Barrier Reef. On Australia’s remote north-west coast there have been fewer studies of coral reproduction. The recent industrial expansion into these regions has facilitated research, but the associated data are often contained within confidential reports. Here we combine information in this grey-literature with that available publicly to update our knowledge of coral reproduction in WA, for tens of thousands of corals and hundreds of species from over a dozen reefs spanning 20° of latitude. We identified broad patterns in coral reproduction, but more detailed insights were hindered by biased sampling; most studies focused on species of Acropora sampled over a few months at several reefs. Within the existing data, there was a latitudinal gradient in spawning activity among seasons, with mass spawning during autumn occurring on all reefs (but the temperate south-west). Participation in a smaller, multi-specific spawning during spring decreased from approximately one quarter of corals on the Kimberley Oceanic reefs to little participation at Ningaloo. Within these seasons, spawning was concentrated in March and/or April, and October and/or November, depending on the timing of

  11. Reproductive technologies in developing countries.

    PubMed

    Macklin, Ruth B

    1995-07-01

    Are there any ethical concerns about reproductive technologies that are specific or unique to developing countries? Three ethical concerns often mentioned specifically in regard to developing countries are (1), the "overpopulation argument"; (2) the limited resources argument; and (3) the ethical problem of poorly trained practitioners offering their services to unsuspecting and uninformed infertile individuals or couples. Each argument is explored in some detail, with the conclusion that ethical problems do, in fact, exist but are not unique to developing countries. Nevertheless, the difficulties relating to reproductive technologies are likely to be greater in developing countries than in developed ones because of limited resources and a larger number of poor people residing there.

  12. Reproductive Technology in the Context of Reproductive Teleology

    ERIC Educational Resources Information Center

    Cooper, Neil J.; Hampton, Simon Jonathan

    2007-01-01

    This article argues that in the ordinary course of events, most parents routinely practice "reproductive teleology" in that they attempt to manipulate the physical and psychological characteristics of children, and they do so as part of the process of good parenting. Furthermore, such attempts are socially approved of and encouraged. With these…

  13. Fundamental Interventions: How Clinicians Can Address the Fundamental Causes of Disease.

    PubMed

    Reich, Adam D; Hansen, Helena B; Link, Bruce G

    2016-06-01

    In order to enhance the "structural competency" of medicine-the capability of clinicians to address social and institutional determinants of their patients' health-physicians need a theoretical lens to see how social conditions influence health and how they might address them. We consider one such theoretical lens, fundamental cause theory, and propose how it might contribute to a more structurally competent medical profession. We first describe fundamental cause theory and how it makes the social causes of disease and health visible. We then outline the sorts of "fundamental interventions" that physicians might make in order to address the fundamental causes. PMID:27022923

  14. Fundamental Vocabulary Selection Based on Word Familiarity

    NASA Astrophysics Data System (ADS)

    Sato, Hiroshi; Kasahara, Kaname; Kanasugi, Tomoko; Amano, Shigeaki

    This paper proposes a new method for selecting fundamental vocabulary. We are presently constructing the Fundamental Vocabulary Knowledge-base of Japanese that contains integrated information on syntax, semantics and pragmatics, for the purposes of advanced natural language processing. This database mainly consists of a lexicon and a treebank: Lexeed (a Japanese Semantic Lexicon) and the Hinoki Treebank. Fundamental vocabulary selection is the first step in the construction of Lexeed. The vocabulary should include sufficient words to describe general concepts for self-expandability, and should not be prohibitively large to construct and maintain. There are two conventional methods for selecting fundamental vocabulary. The first is intuition-based selection by experts. This is the traditional method for making dictionaries. A weak point of this method is that the selection strongly depends on personal intuition. The second is corpus-based selection. This method is superior in objectivity to intuition-based selection, however, it is difficult to compile a sufficiently balanced corpora. We propose a psychologically-motivated selection method that adopts word familiarity as the selection criterion. Word familiarity is a rating that represents the familiarity of a word as a real number ranging from 1 (least familiar) to 7 (most familiar). We determined the word familiarity ratings statistically based on psychological experiments over 32 subjects. We selected about 30,000 words as the fundamental vocabulary, based on a minimum word familiarity threshold of 5. We also evaluated the vocabulary by comparing its word coverage with conventional intuition-based and corpus-based selection over dictionary definition sentences and novels, and demonstrated the superior coverage of our lexicon. Based on this, we conclude that the proposed method is superior to conventional methods for fundamental vocabulary selection.

  15. DOE Fundamentals Handbook: Electrical Science, Volume 4

    SciTech Connect

    Not Available

    1992-06-01

    The Electrical Science Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of electrical theory, terminology, and application. The handbook includes information on alternating current (AC) and direct current (DC) theory, circuits, motors, and generators; AC power and reactive transformers; and electrical test components; batteries; AC and DC voltage regulators; instruments and measuring devices. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility electrical equipment.

  16. Nucleosynthesis and the variation of fundamental couplings

    SciTech Connect

    Mueller, Christian M.; Schaefer, Gregor; Wetterich, Christof

    2004-10-15

    We determine the influence of a variation of the fundamental 'constants' on the predicted helium abundance in Big Bang Nucleosynthesis. The analytic estimate is performed in two parts: the first step determines the dependence of the helium abundance on the nuclear physics parameters, while the second step relates those parameters to the fundamental couplings of particle physics. This procedure can incorporate in a flexible way the time variation of several couplings within a grand unified theory while keeping the nuclear physics computation separate from any GUT model dependence.

  17. DOE Fundamentals Handbook: Electrical Science, Volume 1

    SciTech Connect

    Not Available

    1992-06-01

    The Electrical Science Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of electrical theory, terminology, and application. The handbook includes information on alternating current (AC) and direct current (DC) theory, circuits, motors, and generators; AC power and reactive components; batteries; AC and DC voltage regulators; transformers; and electrical test instruments and measuring devices. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility electrical equipment.

  18. Fundamental ethical principles in health care.

    PubMed

    Thompson, I E

    1987-12-01

    In an attempt to clarify which requirements of morality are logically primary to the ethics of health care, two questions are examined: is there sufficient common ground among the medical, nursing, paramedical, chaplaincy, and social work professions to justify looking for ethical principles common to health care? Do sufficient logical grounds or consensus among health workers and the public exist to speak of "fundamental ethical principles in health care"? While respect for persons, justice, and beneficence are fundamental principles in a formal sense, how we view these principles in practice will depend on our particular culture and experience and the kinds of metaethical criteria we use for applying these principles.

  19. Fundamentals of Pharmacogenetics in Personalized, Precision Medicine.

    PubMed

    Valdes, Roland; Yin, DeLu Tyler

    2016-09-01

    This article introduces fundamental principles of pharmacogenetics as applied to personalized and precision medicine. Pharmacogenetics establishes relationships between pharmacology and genetics by connecting phenotypes and genotypes in predicting the response of therapeutics in individual patients. We describe differences between precision and personalized medicine and relate principles of pharmacokinetics and pharmacodynamics to applications in laboratory medicine. We also review basic principles of pharmacogenetics, including its evolution, how it enables the practice of personalized therapeutics, and the role of the clinical laboratory. These fundamentals are a segue for understanding specific clinical applications of pharmacogenetics described in subsequent articles in this issue.

  20. DOE Fundamentals Handbook: Electrical Science, Volume 2

    SciTech Connect

    Not Available

    1992-06-01

    The Electrical Science Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding terminology, and application. The handbook includes information on alternating current (AC) and direct current (DC) theory, circuits, motors, and generators; AC power and reactive components; batteries; AC and DC voltage regulators; transformers; and electrical test instruments and measuring devices. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility electrical equipment.

  1. Dark Energy: A Crisis for Fundamental Physics

    SciTech Connect

    Stubbs, Christopher

    2010-04-12

    Astrophysical observations provide robust evidence that our current picture of fundamental physics is incomplete. The discovery in 1998 that the expansion of the Universe is accelerating (apparently due to gravitational repulsion between regions of empty space!) presents us with a profound challenge, at the interface between gravity and quantum mechanics. This "Dark Energy" problem is arguably the most pressing open question in modern fundamental physics. The first talk will describe why the Dark Energy problem constitutes a crisis, with wide-reaching ramifications. One consequence is that we should probe our understanding of gravity at all accessible scales, and the second talk will present experiments and observations that are exploring this issue.

  2. DOE Fundamentals Handbook: Mathematics, Volume 2

    SciTech Connect

    Not Available

    1992-06-01

    The Mathematics Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of mathematics and its application to facility operation. The handbook includes a review of introductory mathematics and the concepts and functional use of algebra, geometry, trigonometry, and calculus. Word problems, equations, calculations, and practical exercises that require the use of each of the mathematical concepts are also presented. This information will provide personnel with a foundation for understanding and performing basic mathematical calculations that are associated with various DOE nuclear facility operations.

  3. Fundamentals of Pharmacogenetics in Personalized, Precision Medicine.

    PubMed

    Valdes, Roland; Yin, DeLu Tyler

    2016-09-01

    This article introduces fundamental principles of pharmacogenetics as applied to personalized and precision medicine. Pharmacogenetics establishes relationships between pharmacology and genetics by connecting phenotypes and genotypes in predicting the response of therapeutics in individual patients. We describe differences between precision and personalized medicine and relate principles of pharmacokinetics and pharmacodynamics to applications in laboratory medicine. We also review basic principles of pharmacogenetics, including its evolution, how it enables the practice of personalized therapeutics, and the role of the clinical laboratory. These fundamentals are a segue for understanding specific clinical applications of pharmacogenetics described in subsequent articles in this issue. PMID:27514461

  4. Dark Energy: A Crisis for Fundamental Physics

    ScienceCinema

    Stubbs, Christopher [Harvard University, Cambridge, Massachusetts, USA

    2016-07-12

    Astrophysical observations provide robust evidence that our current picture of fundamental physics is incomplete. The discovery in 1998 that the expansion of the Universe is accelerating (apparently due to gravitational repulsion between regions of empty space!) presents us with a profound challenge, at the interface between gravity and quantum mechanics. This "Dark Energy" problem is arguably the most pressing open question in modern fundamental physics. The first talk will describe why the Dark Energy problem constitutes a crisis, with wide-reaching ramifications. One consequence is that we should probe our understanding of gravity at all accessible scales, and the second talk will present experiments and observations that are exploring this issue.

  5. Assisted reproduction and distributive justice.

    PubMed

    Panitch, Vida

    2015-02-01

    The Canadian province of Quebec recently amended its Health Insurance Act to cover the costs of In Vitro Fertilization (IVF). The province of Ontario recently de-insured IVF. Both provinces cited cost-effectiveness as their grounds, but the question as to whether a public health insurance system ought to cover IVF raises the deeper question of how we should understand reproduction at the social level, and whether its costs should be a matter of individual or collective responsibility. In this article I examine three strategies for justifying collective provisions in a liberal society and assess whether public reproductive assistance can be defended on any of these accounts. I begin by considering, and rejecting, rights-based and needs-based approaches. I go on to argue that instead we ought to address assisted reproduction from the perspective of the contractarian insurance-based model for public health coverage, according to which we select items for inclusion based on their unpredictability in nature and cost. I argue that infertility qualifies as an unpredictable incident against which rational agents would choose to insure under ideal conditions and that assisted reproduction is thereby a matter of collective responsibility, but only in cases of medical necessity or inability to pay. The policy I endorse by appeal to this approach is a means-tested system of coverage resembling neither Ontario nor Quebec's, and I conclude that it constitutes a promising alternative worthy of serious consideration by bioethicists, political philosophers, and policy-makers alike. PMID:24602147

  6. [Male sexual and reproductive rights].

    PubMed

    Diaz, A M

    1998-06-01

    In late 1997, PROFAMILIA began a study of the role of male sexual and reproductive rights as part of the construction of new masculine identities. The work was approached from the disciplines of law and sociology. Patriarchy, as a system of domination, permeated most cultures, giving men a position of power in relation to women and leading to a series of violent and self-destructive male behaviors. The patriarchal system imposed aggressive, promiscuous, risky, and irresponsible behaviors on men, which created a climate for sexual abuse, unwanted pregnancy, propagation of sexually transmitted diseases, and violence against women. Changes in female roles have created the need for changes in male roles. The most visible sexual and reproductive needs of men were studied through literature reviews and semistructured questionnaires with PROFAMILIA clients. Among the needs identified were a new type of male participation in family and domestic life, a new content for male sexual freedom, greater participation of men in reproductive decisions and in raising their children, and new ways of relating to others and sharing feelings and emotions. The need to avoid behaviors that put health at risk was also identified. A review of the evolution of existing sexual and reproductive rights and of the documents that constitute their ethical and juridical framework led to the conclusion that the construction of new rights specifically for men is not necessary, or juridically possible, in the current historical context. PMID:12348800

  7. Wildlife conservation and reproductive cloning.

    PubMed

    Holt, William V; Pickard, Amanda R; Prather, Randall S

    2004-03-01

    Reproductive cloning, or the production of offspring by nuclear transfer, is often regarded as having potential for conserving endangered species of wildlife. Currently, however, low success rates for reproductive cloning limit the practical application of this technique to experimental use and proof of principle investigations. In this review, we consider how cloning may contribute to wildlife conservation strategies. The cloning of endangered mammals presents practical problems, many of which stem from the paucity of knowledge about their basic reproductive biology. However, situations may arise where resources could be targeted at recovering lost or under-represented genetic lines; these could then contribute to the future fitness of the population. Approaches of this type would be preferable to the indiscriminate generation of large numbers of identical individuals. Applying cloning technology to non-mammalian vertebrates may be more practical than attempting to use conventional reproductive technologies. As the scientific background to cloning technology was pioneered using amphibians, it may be possible to breed imminently threatened amphibians, or even restore extinct amphibian species, by the use of cloning. In this respect species with external embryonic development may have an advantage over mammals as developmental abnormalities associated with inappropriate embryonic reprogramming would not be relevant.

  8. REPRODUCTIVE TOXICITY OF PHTHALATE ESTERS

    EPA Science Inventory

    Phthalate esters display several modes of toxicity in mammalian species. In the rat, in utero exposure at relatively low dosage levels disrupts development of the reproductive system of the male rat by altering fetal testis hormone production. This presentation is a review of t...

  9. The aging male reproductive system.

    PubMed

    Tsitouras, P D; Bulat, T

    1995-06-01

    The frequency of sexual activity declines dramatically with age, but this cannot be attributed, with any degree of certainty, to the rather modest hormonal and spermatogenic changes observed with advancing age. Despite the development of intrinsic age-related defects at all levels of the hypothalamic-pituitary-testicular axis, reproductive capacity is maintained in most healthy elderly men.

  10. Reproductive toxicology of nickel - review.

    PubMed

    Forgacs, Zsolt; Massányi, Peter; Lukac, Norbert; Somosy, Zoltan

    2012-01-01

    The goal of this minireview is to summarize our current knowledge on the reproductive toxicity of soluble nickel salts. We made an attempt to present the most relevant data obtained from in vivo and in vitro experiments performed on mammals, mammalian primary cell cultures and cell lines. Nickel has been demonstrated to disturb the mammalian reproductive functions at several levels of regulation. The results of previous investigations indicate that the hormonal effects may play an important role in the reproductive toxicology of nickel both at the neuroendocrine and gonadal levels in the hypothalamic-pituitary-gonadal (HPG) axis. At the molecular level, it may be important that nickel may substitute certain other metals in metal dependent enzymes, leading to an altered protein function. It readily crosses the cell membrane via calcium channels and competes with calcium for specific receptors. Nickel can cross-link aminoacids to DNA, lead to formation of reactive oxygen species (ROS), moreover mimic hypoxia. These changes may lead to the activation of some signaling pathways, subsequent transcription factors and eventually to alterations in gene expression and cellular metabolism. These events are likely to be involved in the reproductive toxicity of nickel.

  11. Interpretive Reproduction in Children's Play

    ERIC Educational Resources Information Center

    Corsaro, William A.

    2012-01-01

    The author looks at children's play from the perspective of interpretive reproduction, emphasizing the way children create their own unique peer cultures, which he defines as a set of routines, artifacts, values, and concerns that children engage in with their playmates. The article focuses on two types of routines in the peer culture of preschool…

  12. Chapter 22: Female Reproductive Toxicology

    EPA Science Inventory

    The female reproductive system provides multiple targets for environmental toxicants with the hypothalamic-pituitary-ovarian axis. Moreover, the functional impact of a chemical can differ, depending on the species involved and the parameters of exposure. While cross-species compa...

  13. Reproductive genetic testing and eugenics.

    PubMed

    Braga, Suzanne

    1993-04-01

    The situation concerning reproductive genetic testing in Switzerland is briefly described. Growing awareness of eugenic implications especially by women is reported. This is also true for all the other German-speaking countries in Europe to a higher extent than in the other European countries. Better professional education and public information are required.

  14. Society for Reproductive Endocrinology and Infertility

    MedlinePlus

    The Society for Reproductive Endocrinology and Infertility SREI Members-only Forum Home About Us About SREI Vision and Mission ... Fact Sheets and Booklets SREI is an affiliated society to the American Society for Reproductive Medicine . Below ...

  15. Cold-seeking behaviour mitigates reproductive losses from fungal infection in Drosophila.

    PubMed

    Hunt, Vicky L; Zhong, Weihao; McClure, Colin D; Mlynski, David T; Duxbury, Elizabeth M L; Keith Charnley, A; Priest, Nicholas K

    2016-01-01

    Animals must tailor their life-history strategies to suit the prevailing conditions and respond to hazards in the environment. Animals with lethal infections are faced with a difficult choice: to allocate more resources to reproduction and suffer higher mortality or to reduce reproduction with the expectation of enhanced immunity and late-age reproduction. However, the strategies employed to mediate shifts in life-history traits are largely unknown. Here, we investigate the temperature preference of the fruit fly, Drosophila melanogaster, during infection with the fungal pathogen, Metarhizium robertsii, and the consequence of temperature preference on life-history traits. We have measured the temperature preference of fruit flies under different pathogen conditions. We conducted multiple fitness assays of the host and the pathogen under different thermal conditions. From these data, we estimated standard measures of fitness and used age-specific methodologies to test for the fitness trade-offs that are thought to underlie differences in life-history strategy. We found that fungus-infected fruit flies seek out cooler temperatures, which facilitates an adaptive shift in their life-history strategy. The colder temperatures preferred by infected animals were detrimental to the pathogen because it increased resistance to infection. But, it did not provide net benefits that were specific to infected animals, as cooler temperatures increased lifetime reproductive success and survival whether or not the animals were infected. Instead, we find that cold-seeking benefits infected animals by increasing their late-age reproductive output, at a cost to their early-age reproductive output. In contrast, naive control flies prefer warmer temperatures that optimize early-age reproductive, at a cost to reproductive output at late ages. These findings show that infected animals exhibit fundamentally different reproductive strategies than their healthy counterparts. Temperature

  16. Cold-seeking behaviour mitigates reproductive losses from fungal infection in Drosophila.

    PubMed

    Hunt, Vicky L; Zhong, Weihao; McClure, Colin D; Mlynski, David T; Duxbury, Elizabeth M L; Keith Charnley, A; Priest, Nicholas K

    2016-01-01

    Animals must tailor their life-history strategies to suit the prevailing conditions and respond to hazards in the environment. Animals with lethal infections are faced with a difficult choice: to allocate more resources to reproduction and suffer higher mortality or to reduce reproduction with the expectation of enhanced immunity and late-age reproduction. However, the strategies employed to mediate shifts in life-history traits are largely unknown. Here, we investigate the temperature preference of the fruit fly, Drosophila melanogaster, during infection with the fungal pathogen, Metarhizium robertsii, and the consequence of temperature preference on life-history traits. We have measured the temperature preference of fruit flies under different pathogen conditions. We conducted multiple fitness assays of the host and the pathogen under different thermal conditions. From these data, we estimated standard measures of fitness and used age-specific methodologies to test for the fitness trade-offs that are thought to underlie differences in life-history strategy. We found that fungus-infected fruit flies seek out cooler temperatures, which facilitates an adaptive shift in their life-history strategy. The colder temperatures preferred by infected animals were detrimental to the pathogen because it increased resistance to infection. But, it did not provide net benefits that were specific to infected animals, as cooler temperatures increased lifetime reproductive success and survival whether or not the animals were infected. Instead, we find that cold-seeking benefits infected animals by increasing their late-age reproductive output, at a cost to their early-age reproductive output. In contrast, naive control flies prefer warmer temperatures that optimize early-age reproductive, at a cost to reproductive output at late ages. These findings show that infected animals exhibit fundamentally different reproductive strategies than their healthy counterparts. Temperature

  17. Monte Carlo simulations of sexual reproduction

    NASA Astrophysics Data System (ADS)

    Stauffer, D.; de Oliveira, P. M. C.; de Oliveira, S. Moss; dos Santos, R. M. Zorzenon

    1996-02-01

    Modifying the Redfield model of sexual reproduction and the Penna model of biological aging, we compare reproduction with and without recombination in age-structured populations. In constrast to Redfield and in agreement with Bernardes we find sexual reproduction to be preferred to asexual one. In particular, the presence of old but still reproducing males helps the survival of younger females beyond their reproductive age.

  18. Pulsed electric field increases reproduction.

    PubMed

    Panagopoulos, Dimitris J

    2016-01-01

    Purpose To study the effect of pulsed electric field - applied in corona discharge photography - on Drosophila melanogaster reproduction, possible induction of DNA fragmentation, and morphological alterations in the gonads. Materials and methods Animals were exposed to different field intensities (100, 200, 300, and 400 kV/m) during the first 2-5 days of their adult lives, and the effect on reproductive capacity was assessed. DNA fragmentation during early- and mid-oogenesis was investigated by application of the TUNEL (Terminal deoxynucleotide transferase dUTP Nick End Labeling) assay. Sections of follicles after fixation and embedding in resins were observed for possible morphological/developmental abnormalities. Results The field increased reproduction by up to 30% by increasing reproductive capacity in both sexes. The effect increased with increasing field intensities. The rate of increase diminished at the strongest intensities. Slight induction of DNA fragmentation was observed exclusively in the nurse (predominantly) and follicle cells, and exclusively at the two most sensitive developmental stages, i.e., germarium and predominantly stage 7-8. Sections of follicles from exposed females at stages of early and mid-oogennesis other than germarium and stages 7-8 did not reveal abnormalities. Conclusions (1) The specific type of electric field may represent a mild stress factor, inducing DNA fragmentation and cell death in a small percentage of gametes, triggering the reaction of the animal's reproductive system to increase the rate of gametogenesis in order to compensate the loss of a small number of gametes. (2) The nurse cells are the most sensitive from all three types of egg chamber cells. (3) The mid-oogenesis checkpoint (stage 7-8) is more sensitive to this field than the early oogenesis one (germarium) in contrast to microwave exposure. (4) Possible therapeutic applications, or applications in increasing fertility, should be investigated.

  19. Pulsed electric field increases reproduction.

    PubMed

    Panagopoulos, Dimitris J

    2016-01-01

    Purpose To study the effect of pulsed electric field - applied in corona discharge photography - on Drosophila melanogaster reproduction, possible induction of DNA fragmentation, and morphological alterations in the gonads. Materials and methods Animals were exposed to different field intensities (100, 200, 300, and 400 kV/m) during the first 2-5 days of their adult lives, and the effect on reproductive capacity was assessed. DNA fragmentation during early- and mid-oogenesis was investigated by application of the TUNEL (Terminal deoxynucleotide transferase dUTP Nick End Labeling) assay. Sections of follicles after fixation and embedding in resins were observed for possible morphological/developmental abnormalities. Results The field increased reproduction by up to 30% by increasing reproductive capacity in both sexes. The effect increased with increasing field intensities. The rate of increase diminished at the strongest intensities. Slight induction of DNA fragmentation was observed exclusively in the nurse (predominantly) and follicle cells, and exclusively at the two most sensitive developmental stages, i.e., germarium and predominantly stage 7-8. Sections of follicles from exposed females at stages of early and mid-oogennesis other than germarium and stages 7-8 did not reveal abnormalities. Conclusions (1) The specific type of electric field may represent a mild stress factor, inducing DNA fragmentation and cell death in a small percentage of gametes, triggering the reaction of the animal's reproductive system to increase the rate of gametogenesis in order to compensate the loss of a small number of gametes. (2) The nurse cells are the most sensitive from all three types of egg chamber cells. (3) The mid-oogenesis checkpoint (stage 7-8) is more sensitive to this field than the early oogenesis one (germarium) in contrast to microwave exposure. (4) Possible therapeutic applications, or applications in increasing fertility, should be investigated. PMID:26651869

  20. Course Objectives: Electronic Fundamentals, EL16.

    ERIC Educational Resources Information Center

    Wilson, David H.

    The general objective, recommended text, and specific objectives of a course titled "Electronic Fundamentals," as offered at St. Lawrence College of Applied Arts and Technology, are provided. The general objective of the course is "to acquire an understanding of diodes, transistors, and tubes, and so be able to analyze the operation of single…

  1. Getting a Better Grasp on Flu Fundamentals

    MedlinePlus

    ... a Better Grasp on Flu Fundamentals Inside Life Science View All Articles | Inside Life Science Home Page Getting a Better Grasp on Flu ... Seasonal Flu Patterns? Forecasting Flu This Inside Life Science article also appears on LiveScience . Learn about related ...

  2. Uncovering Racial Bias in Nursing Fundamentals Textbooks.

    ERIC Educational Resources Information Center

    Byrne, Michelle M.

    2001-01-01

    The portrayal of African Americans in nursing fundamentals textbooks was analyzed, resulting in 11 themes in the areas of history, culture, and physical assessment. Few African American leaders were included, and racial bias and stereotyping were apparent. Differences were often discussed using Eurocentric norms, and language tended to minimize…

  3. Fundamental Theorems of Algebra for the Perplexes

    ERIC Educational Resources Information Center

    Poodiak, Robert; LeClair, Kevin

    2009-01-01

    The fundamental theorem of algebra for the complex numbers states that a polynomial of degree n has n roots, counting multiplicity. This paper explores the "perplex number system" (also called the "hyperbolic number system" and the "spacetime number system") In this system (which has extra roots of +1 besides the usual [plus or minus]1 of the…

  4. Solar Energy: Solar System Design Fundamentals.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on solar system design fundamentals is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy…

  5. Fundamental Concepts Bridging Education and the Brain

    ERIC Educational Resources Information Center

    Masson, Steve; Foisy, Lorie-Marlène Brault

    2014-01-01

    Although a number of papers have already discussed the relevance of brain research for education, the fundamental concepts and discoveries connecting education and the brain have not been systematically reviewed yet. In this paper, four of these concepts are presented and evidence concerning each one is reviewed. First, the concept of…

  6. The Case for Fundamentals of Oral Communication

    ERIC Educational Resources Information Center

    Emanuel, Richard

    2005-01-01

    Dozens of studies support the fact that communication skills are essential for success in a number of areas. After citing a sampling of these studies, a survey of the communication course offerings in Alabama's 2-year-college system reveals that most students are required to take only one communication course-either Fundamentals of Oral…

  7. Measurement and Fundamental Processes in Quantum Mechanics

    NASA Astrophysics Data System (ADS)

    Jaeger, Gregg

    2015-07-01

    In the standard mathematical formulation of quantum mechanics, measurement is an additional, exceptional fundamental process rather than an often complex, but ordinary process which happens also to serve a particular epistemic function: during a measurement of one of its properties which is not already determined by a preceding measurement, a measured system, even if closed, is taken to change its state discontinuously rather than continuously as is usual. Many, including Bell, have been concerned about the fundamental role thus given to measurement in the foundation of the theory. Others, including the early Bohr and Schwinger, have suggested that quantum mechanics naturally incorporates the unavoidable uncontrollable disturbance of physical state that accompanies any local measurement without the need for an exceptional fundamental process or a special measurement theory. Disturbance is unanalyzable for Bohr, but for Schwinger it is due to physical interactions' being borne by fundamental particles having discrete properties and behavior which is beyond physical control. Here, Schwinger's approach is distinguished from more well known treatments of measurement, with the conclusion that, unlike most, it does not suffer under Bell's critique of quantum measurement. Finally, Schwinger's critique of measurement theory is explicated as a call for a deeper investigation of measurement processes that requires the use of a theory of quantum fields.

  8. Drafting Fundamentals. Drafting Module 1. Instructor's Guide.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Instructional Materials Lab.

    This Missouri Vocational Instruction Management System instructor's drafting guide has been keyed to the drafting competency profile developed by state industry and education professionals. The guide contains a cross-reference table of instructional materials. Ten units cover drafting fundamentals: (1) introduction to drafting; (2) general safety;…

  9. Fundamentals of Athletic Training. Second Edition.

    ERIC Educational Resources Information Center

    Behling, Fred L.; And Others

    This book provides an authoritative reference on the fundamentals of athletic training for people with varied backgrounds but a common interest in the health and education of the high school athlete. The book is designed especially for the novice athletic trainer. Section 1 of the book concerns the organization and administration of athletic…

  10. Mathematical Literacy--It's Become Fundamental

    ERIC Educational Resources Information Center

    McCrone, Sharon Soucy; Dossey, John A.

    2007-01-01

    The rising tide of numbers and statistics in daily life signals a need for a fundamental broadening of the concept of literacy: mathematical literacy assuming a coequal role in the curriculum alongside language-based literacy. Mathematical literacy is not about studying higher levels of formal mathematics, but about making math relevant and…

  11. A Fundamental Breakdown. Part II: Manipulative Skills

    ERIC Educational Resources Information Center

    Townsend, J. Scott; Mohr, Derek J.

    2005-01-01

    In the May, 2005, issue of "TEPE," the "Research to Practice" section initiated a two-part series focused on assessing fundamental locomotor and manipulative skills. The series was generated in response to research by Pappa, Evanggelinou, & Karabourniotis (2005), recommending that curricular programming in physical education at the elementary…

  12. A Fundamental Theorem on Particle Acceleration

    SciTech Connect

    Xie, Ming

    2003-05-01

    A fundamental theorem on particle acceleration is derived from the reciprocity principle of electromagnetism and a rigorous proof of the theorem is presented. The theorem establishes a relation between acceleration and radiation, which is particularly useful for insightful understanding of and practical calculation about the first order acceleration in which energy gain of the accelerated particle is linearly proportional to the accelerating field.

  13. Man's Size in Terms of Fundamental Constants.

    ERIC Educational Resources Information Center

    Press, William H.

    1980-01-01

    Reviews calculations that derive an order of magnitude expression for the size of man in terms of fundamental constants, assuming that man satifies these three properties: he is made of complicated molecules; he requires an atmosphere which is not hydrogen and helium; he is as large as possible. (CS)

  14. Euler and the Fundamental Theorem of Algebra.

    ERIC Educational Resources Information Center

    Duham, William

    1991-01-01

    The complexity of the proof of the Fundamental Theorem of Algebra makes it inaccessible to lower level students. Described are more understandable attempts of proving the theorem and a historical account of Euler's efforts that relates the progression of the mathematical process used and indicates some of the pitfalls encountered. (MDH)

  15. The equivalent fundamental-mode source

    SciTech Connect

    Spriggs, G.D.; Busch, R.D.; Sakurai, Takeshi; Okajima, Shigeaki

    1997-02-01

    In 1960, Hansen analyzed the problem of assembling fissionable material in the presence of a weak neutron source. Using point kinetics, he defined the weak source condition and analyzed the consequences of delayed initiation during ramp reactivity additions. Although not clearly stated in Hansen`s work, the neutron source strength that appears in the weak source condition corresponds to the equivalent fundamental-mode source. In this work, we describe the concept of an equivalent fundamental-mode source and we derive a deterministic expression for a factor, g*, that converts any arbitrary source distribution to an equivalent fundamental-mode source. We also demonstrate a simplified method for calculating g* in subcritical systems. And finally, we present a new experimental method that can be employed to measure the equivalent fundamental-mode source strength in a multiplying assembly. We demonstrate the method on the zero-power, XIX-1 assembly at the Fast Critical Assembly (FCA) Facility, Japan Atomic Energy Research Institute (JAERI).

  16. Fundamental studies on passivity and passivity breakdown

    SciTech Connect

    Macdonald, D.D.; Urquidi-Macdonald, M.

    1993-06-01

    Using photoelectrochemical impedance and admittance spectroscopies, a fundamental and quantitative understanding of the mechanisms for the growth and breakdown of passive films on metal and alloy surfaces in contact with aqueous environments is being developed. A point defect model has been extended to explain the breakdown of passive films, leading to pitting and crack growth and thus development of damage due to localized corrosion.

  17. Retention of Electronic Fundamentals: Differences Among Topics.

    ERIC Educational Resources Information Center

    Johnson, Kirk A.

    Criterion-referenced tests were used to measure the learning and retention of a sample of material taught by means of programed instruction in the Avionics Fundamentals Course, Class A. It was found that the students knew about 30 percent of the material before reading the programs, that mastery rose to a very high level on the immediate posttest,…

  18. Why quarks cannot be fundamental particles

    NASA Astrophysics Data System (ADS)

    Kalman, C. S.

    2005-05-01

    Many reasons why quarks should be considered composite particles are found in the book Preons by D'Souza and Kalman. One reason not found in the book is that all the quarks except for the u quark decay. The electron and the electron neutrino do not decay. A model of fundamental particles based upon the weak charge is presented.

  19. Fundamental and Gradient Differences in Language Development

    ERIC Educational Resources Information Center

    Herschensohn, Julia

    2009-01-01

    This article reexamines Bley-Vroman's original (1990) and evolved fundamental difference hypothesis that argues that differences in path and endstate of first language acquisition and adult foreign language learning result from differences in the acquisition procedure (i.e., language faculty and cognitive strategies, respectively). The evolved…

  20. Fundamental Movement Skills and Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Staples, Kerri L.; Reid, Greg

    2010-01-01

    Delays and deficits may both contribute to atypical development of movement skills by children with ASD. Fundamental movement skills of 25 children with autism spectrum disorders (ASD) (ages 9-12 years) were compared to three typically developing groups using the "Test of Gross Motor Development" ("TGMD-2"). The group matched on chronological age…

  1. On some fundamental concepts of galactic dynamics

    NASA Astrophysics Data System (ADS)

    Ossipkov, L. P.

    2013-10-01

    We discuss the following fundamental concepts of galactic dynamics: (a) regular (smoothed) and irregular (random) forces, (b) truncation of the impact parameter, (c) the invariance of the Maxwellian velocity distribution, and (d) the Jeans theorem. Dedicated to Felix Alexandrovich Tsitsin (1931-2005)

  2. Reversing: A Fundamental Idea in Computer Science

    ERIC Educational Resources Information Center

    Armoni, Michal; Ginat, David

    2008-01-01

    Reversing is the notion of thinking or working in reverse. Computer science textbooks and tutors recognize it primarily in the form of recursion. However, recursion is only one form of reversing. Reversing appears in the computer science curriculum in many other forms, at various intellectual levels, in a variety of fundamental courses. As such,…

  3. Radio and Television Repairer Fundamentals. Student's Manual.

    ERIC Educational Resources Information Center

    Maul, Chuck

    This self-contained student manual on fundamentals of radio and television repair is designed to help trade and industrial students relate work experience on the job to information studied at school. Designed for individualized instruction under the supervision of a coordinator or instructor, the manual has 9 sections, each containing 2 to 10…

  4. The ecology and evolutionary endocrinology of reproduction in the human female.

    PubMed

    Vitzthum, Virginia J

    2009-01-01

    Human reproductive ecology (HRE) is the study of the mechanisms that link variation in reproductive traits with variation in local habitats. Empirical and theoretical contributions from biological anthropology, physiology, and demography have established the foundation necessary for developing a comprehensive understanding, grounded in life history theory (LHT), of temporal, individual, and populational variation in women's reproductive functioning. LHT posits that natural selection leads to the evolution of mechanisms that tend to allocate resources to the competing demands of growth, reproduction, and survival such that fitness is locally maximized. (That is, among alternative allocation patterns exhibited in a population, those having the highest inclusive fitness will become more common over generational time.) Hence, strategic modulation of reproductive effort is potentially adaptive because investment in a new conception may risk one's own survival, future reproductive opportunities, and/or current offspring survival. The hypothalamic-pituitary-ovarian (HPO) axis is the principal neuroendocrine pathway by which the human female modulates reproductive functioning according to the changing conditions in her habitat. Adjustments of reproductive investment in a potential conception are manifested in temporal and individual variation in ovarian cycle length, ovulation, hormone levels, and the probability of conception. Understanding the extent and causes of adaptive and non-adaptive variation in ovarian functioning is fundamental to ascertaining the proximate and remote determinants of human reproductive patterns. In this review I consider what is known and what still needs to be learned of the ecology of women's reproductive biology, beginning with a discussion of the principal explanatory frameworks in HRE and the biometry of ovarian functioning. Turning next to empirical studies, it is evident that marked variation between cycles, women, and populations is the

  5. Asexual Plant Reproduction. Agricultural Lesson Plans.

    ERIC Educational Resources Information Center

    Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

    These lesson plans are intended for use in conducting classes on asexual plant reproduction. Presented first are an attention step/problem statement and a series of questions and answers designed to convey general information about asexual plant reproduction/propagation. The following topics are among those discussed: plant reproduction methods,…

  6. 76 FR 62632 - NARA Records Reproduction Fees

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-11

    ... published a proposed rule in the Federal Register (76 FR 43960) for a 60-day public comment period. This... RECORDS ADMINISTRATION 36 CFR Part 1258 RIN 3095-AB71 NARA Records Reproduction Fees AGENCY: National... reproduction fees, to remove records reproduction fees found in its regulations, and to provide a...

  7. Approved Practices in Dairy Reproduction. Slide Script.

    ERIC Educational Resources Information Center

    Roediger, Roger D.; Barr, Harry L.

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with approved practices in dairy reproduction. Included in the guide are narrations for use with 200 slides dealing with the following topics: the importance of good reproduction, the male and female roles in reproduction, selection of…

  8. [Role of estrogen in male reproduction].

    PubMed

    Pan, Yi-Qing; Xu, Chen

    2005-11-01

    Estrogen plays an essential role in male reproduction. In human and other mammalians, a number of tissues express aromatase and hence synthesize estrogen. ERs and aromatase are present at all developmental stages of the male reproductive organs in many mammalian species. Estrogen is important in different aspects in male reproductive physiology, including its effects on germ cells, Sertoli cells, Leydig cells and epididymal functions.

  9. 32 CFR 2700.43 - Reproduction controls.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Reproduction controls. 2700.43 Section 2700.43... SECURITY INFORMATION REGULATIONS Safeguarding § 2700.43 Reproduction controls. OMSN and SLNO shall maintain records to show the number and distribution of all OMSN originated classified documents. Reproduction...

  10. 32 CFR 2700.43 - Reproduction controls.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Reproduction controls. 2700.43 Section 2700.43... SECURITY INFORMATION REGULATIONS Safeguarding § 2700.43 Reproduction controls. OMSN and SLNO shall maintain records to show the number and distribution of all OMSN originated classified documents. Reproduction...

  11. 44 CFR 6.85 - Reproduction fees.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Reproduction fees. 6.85... HOMELAND SECURITY GENERAL IMPLEMENTATION OF THE PRIVACY ACT OF 1974 Fees § 6.85 Reproduction fees. (a... over 81/2 x 14 inches or whose physical characteristics do not permit reproduction by...

  12. 42 CFR 9.7 - Reproduction.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Reproduction. 9.7 Section 9.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS STANDARDS OF CARE FOR CHIMPANZEES HELD IN THE FEDERALLY SUPPORTED SANCTUARY SYSTEM § 9.7 Reproduction. Chimpanzee reproduction...

  13. 36 CFR 705.4 - Reproduction.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Reproduction. 705.4 Section 705.4 Parks, Forests, and Public Property LIBRARY OF CONGRESS REPRODUCTION, COMPILATION, AND....4 Reproduction. (a) Library of Congress staff acting under the general authority of the Librarian...

  14. 31 CFR 402.1 - Reproductions authorized.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 2 2013-07-01 2013-07-01 false Reproductions authorized. 402.1... SERVICE, DEPARTMENT OF THE TREASURY REPRODUCTION OF CANCELED UNITED STATES INTERNAL REVENUE STAMPS § 402.1 Reproductions authorized. Authority is hereby given to make, hold, and dispose of black and white...

  15. 32 CFR 2700.43 - Reproduction controls.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Reproduction controls. 2700.43 Section 2700.43... SECURITY INFORMATION REGULATIONS Safeguarding § 2700.43 Reproduction controls. OMSN and SLNO shall maintain records to show the number and distribution of all OMSN originated classified documents. Reproduction...

  16. 32 CFR 2103.41 - Reproduction controls.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Reproduction controls. 2103.41 Section 2103.41... Safeguarding § 2103.41 Reproduction controls. The Staff Secretary shall maintain records to show the number and... dissemination or reproduction limitations....

  17. 42 CFR 9.7 - Reproduction.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Reproduction. 9.7 Section 9.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS STANDARDS OF CARE FOR CHIMPANZEES HELD IN THE FEDERALLY SUPPORTED SANCTUARY SYSTEM § 9.7 Reproduction. Chimpanzee reproduction...

  18. 44 CFR 6.85 - Reproduction fees.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 44 Emergency Management and Assistance 1 2014-10-01 2014-10-01 false Reproduction fees. 6.85... HOMELAND SECURITY GENERAL IMPLEMENTATION OF THE PRIVACY ACT OF 1974 Fees § 6.85 Reproduction fees. (a... 81/2×14 inches or whose physical characteristics do not permit reproduction by routine...

  19. 31 CFR 402.1 - Reproductions authorized.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 2 2014-07-01 2014-07-01 false Reproductions authorized. 402.1... SERVICE, DEPARTMENT OF THE TREASURY REPRODUCTION OF CANCELED UNITED STATES INTERNAL REVENUE STAMPS § 402.1 Reproductions authorized. Authority is hereby given to make, hold, and dispose of black and white...

  20. 42 CFR 9.7 - Reproduction.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Reproduction. 9.7 Section 9.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS STANDARDS OF CARE FOR CHIMPANZEES HELD IN THE FEDERALLY SUPPORTED SANCTUARY SYSTEM § 9.7 Reproduction. Chimpanzee reproduction...

  1. 36 CFR 705.4 - Reproduction.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Reproduction. 705.4 Section 705.4 Parks, Forests, and Public Property LIBRARY OF CONGRESS REPRODUCTION, COMPILATION, AND....4 Reproduction. (a) Library of Congress staff acting under the general authority of the Librarian...

  2. 31 CFR 402.1 - Reproductions authorized.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Reproductions authorized. 402.1... SERVICE, DEPARTMENT OF THE TREASURY REPRODUCTION OF CANCELED UNITED STATES INTERNAL REVENUE STAMPS § 402.1 Reproductions authorized. Authority is hereby given to make, hold, and dispose of black and white...

  3. 31 CFR 402.1 - Reproductions authorized.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 2 2012-07-01 2012-07-01 false Reproductions authorized. 402.1... SERVICE, DEPARTMENT OF THE TREASURY REPRODUCTION OF CANCELED UNITED STATES INTERNAL REVENUE STAMPS § 402.1 Reproductions authorized. Authority is hereby given to make, hold, and dispose of black and white...

  4. 44 CFR 6.85 - Reproduction fees.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false Reproduction fees. 6.85... HOMELAND SECURITY GENERAL IMPLEMENTATION OF THE PRIVACY ACT OF 1974 Fees § 6.85 Reproduction fees. (a... over 81/2 x 14 inches or whose physical characteristics do not permit reproduction by...

  5. 32 CFR 2700.43 - Reproduction controls.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Reproduction controls. 2700.43 Section 2700.43... SECURITY INFORMATION REGULATIONS Safeguarding § 2700.43 Reproduction controls. OMSN and SLNO shall maintain records to show the number and distribution of all OMSN originated classified documents. Reproduction...

  6. 32 CFR 2103.41 - Reproduction controls.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Reproduction controls. 2103.41 Section 2103.41... Safeguarding § 2103.41 Reproduction controls. The Staff Secretary shall maintain records to show the number and... dissemination or reproduction limitations....

  7. 32 CFR 2103.41 - Reproduction controls.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Reproduction controls. 2103.41 Section 2103.41... Safeguarding § 2103.41 Reproduction controls. The Staff Secretary shall maintain records to show the number and... dissemination or reproduction limitations....

  8. 42 CFR 9.7 - Reproduction.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Reproduction. 9.7 Section 9.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS STANDARDS OF CARE FOR CHIMPANZEES HELD IN THE FEDERALLY SUPPORTED SANCTUARY SYSTEM § 9.7 Reproduction. Chimpanzee reproduction...

  9. 36 CFR 705.4 - Reproduction.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Reproduction. 705.4 Section 705.4 Parks, Forests, and Public Property LIBRARY OF CONGRESS REPRODUCTION, COMPILATION, AND....4 Reproduction. (a) Library of Congress staff acting under the general authority of the Librarian...

  10. 32 CFR 2103.41 - Reproduction controls.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Reproduction controls. 2103.41 Section 2103.41... Safeguarding § 2103.41 Reproduction controls. The Staff Secretary shall maintain records to show the number and... dissemination or reproduction limitations....

  11. 36 CFR 705.4 - Reproduction.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Reproduction. 705.4 Section 705.4 Parks, Forests, and Public Property LIBRARY OF CONGRESS REPRODUCTION, COMPILATION, AND....4 Reproduction. (a) Library of Congress staff acting under the general authority of the Librarian...

  12. 42 CFR 9.7 - Reproduction.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Reproduction. 9.7 Section 9.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS STANDARDS OF CARE FOR CHIMPANZEES HELD IN THE FEDERALLY SUPPORTED SANCTUARY SYSTEM § 9.7 Reproduction. Chimpanzee reproduction...

  13. 32 CFR 2700.43 - Reproduction controls.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Reproduction controls. 2700.43 Section 2700.43... SECURITY INFORMATION REGULATIONS Safeguarding § 2700.43 Reproduction controls. OMSN and SLNO shall maintain records to show the number and distribution of all OMSN originated classified documents. Reproduction...

  14. 36 CFR 705.4 - Reproduction.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Reproduction. 705.4 Section 705.4 Parks, Forests, and Public Property LIBRARY OF CONGRESS REPRODUCTION, COMPILATION, AND....4 Reproduction. (a) Library of Congress staff acting under the general authority of the Librarian...

  15. 44 CFR 6.85 - Reproduction fees.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Reproduction fees. 6.85... HOMELAND SECURITY GENERAL IMPLEMENTATION OF THE PRIVACY ACT OF 1974 Fees § 6.85 Reproduction fees. (a... over 81/2 x 14 inches or whose physical characteristics do not permit reproduction by...

  16. 44 CFR 6.85 - Reproduction fees.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 44 Emergency Management and Assistance 1 2013-10-01 2013-10-01 false Reproduction fees. 6.85... HOMELAND SECURITY GENERAL IMPLEMENTATION OF THE PRIVACY ACT OF 1974 Fees § 6.85 Reproduction fees. (a... 81/2×14 inches or whose physical characteristics do not permit reproduction by routine...

  17. 31 CFR 402.1 - Reproductions authorized.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 2 2011-07-01 2011-07-01 false Reproductions authorized. 402.1... SERVICE, DEPARTMENT OF THE TREASURY REPRODUCTION OF CANCELED UNITED STATES INTERNAL REVENUE STAMPS § 402.1 Reproductions authorized. Authority is hereby given to make, hold, and dispose of black and white...

  18. 32 CFR 2103.41 - Reproduction controls.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Reproduction controls. 2103.41 Section 2103.41... Safeguarding § 2103.41 Reproduction controls. The Staff Secretary shall maintain records to show the number and... dissemination or reproduction limitations....

  19. Therapeutic and reproductive cloning--implications and recommendations.

    PubMed

    Ng, S C; Ng, Y; Liow, S L; Chen, N

    2003-03-01

    The announcement of Dolly's birth took the world by storm, mainly because what was thought impossible has become possible. Optimism that new approaches in agriculture and medicine abound, as much as fear and imagination leading to Frankenstein-like scenarios. Scientifically, cloning refers to replicating an animal with the same nuclear genetic material; whilst it may refer to embryos as the source material, the current storm refers to differentiated ("somatic") cells. Cloning technology is useful in the following areas: agriculture, to produce animals of superior or specific qualities; endangered animals, to increase genetic diversity through widening the gene pool; understanding fundamental questions in developmental embryology, through the use of laboratory animals; and in human therapy, to produce cells and possibly tissues for repair and regeneration. In the first 2 instances, it is reproductive cloning. In the last instance, it is therapeutic cloning, as no individuals are "produced". Human reproductive cloning is not allowed by all governments that have deliberated on it, and therapeutic cloning is allowed by some under certain circumstances. As therapeutic cloning has great potential in cures of many diseases, it should be allowed but with safeguards to prevent abuse and reproductive cloning in the human.

  20. Dynamic Reciprocity Between Cells and Their Microenvironment in Reproduction1

    PubMed Central

    Thorne, Jeffrey T.; Segal, Thalia R.; Chang, Sydney; Jorge, Soledad; Segars, James H.; Leppert, Phyllis C.

    2014-01-01

    ABSTRACT Dynamic reciprocity (DR) refers to the ongoing, bidirectional interaction between cells and their microenvironment, specifically the extracellular matrix (ECM). The continuous remodeling of the ECM exerts mechanical force on cells and modifies biochemical mediators near the cell membrane, thereby initiating cell-signaling cascades that produce changes in gene expression and cell behavior. Cellular changes, in turn, affect the composition and organization of ECM components. These continuous interactions are the fundamental principle behind DR, and its critical role throughout development and adult tissue homeostasis has been extensively investigated. While DR in the mammary gland has been well described, we provide direct evidence that similar dynamic interactions occur in other areas of reproductive biology as well. In order to establish the importance of DR in the adaptive functioning of the female reproductive tract, we present our most current understanding of DR in reproductive tissues, exploring the mammary gland, ovary, and uterus. In addition to explaining normal physiological function, investigating DR may shed new light into pathologic processes that occur in these tissues and provide an exciting opportunity for novel therapeutic intervention. PMID:25411389

  1. Synchronisation of ovulation for management of reproduction in dairy cows.

    PubMed

    Bisinotto, R S; Ribeiro, E S; Santos, J E P

    2014-05-01

    Important developments have occurred in the last two decades, since the advent of the Ovsynch protocol, on the understanding and use of synchronisation programmes for management of reproduction in dairy herds. This better understanding of oestrus cycle control associated with suboptimal reproductive performance in dairy herds has led dairy producers to quickly adopt timed artificial insemination (AI) protocols. Recent surveys have documented that fixed-time AI has become an important component of management of reproduction in high-producing herds. Furthermore, timed AI protocols have also demonstrated benefits in pasture-based milk production systems because of the ability to increase insemination rate. In general, successful use of the Ovsynch protocol requires some fundamental physiological principles to be respected, including: induction of ovulation to synchronise follicle growth in the first 2 days of the programme such that a young antral follicle is recruited; maintenance of high concentrations of progesterone during the development of the ovulatory follicle, but also effectively lyse the corpus luteum to result in very low concentration of progesterone at AI; and having a healthy pre-ovulatory follicle of moderate diameter that is highly oestrogenic and responsive to gonadotropins to synchronously ovulate 12 to 18 h after insemination. Current methods oestrous and ovulation synchronisation are still not optimal and future improvements will likely require new technologies for hormone formulation and delivery such that additional interventions are minimised to maintain acceptance by producers. PMID:24709227

  2. Synchronisation of ovulation for management of reproduction in dairy cows.

    PubMed

    Bisinotto, R S; Ribeiro, E S; Santos, J E P

    2014-05-01

    Important developments have occurred in the last two decades, since the advent of the Ovsynch protocol, on the understanding and use of synchronisation programmes for management of reproduction in dairy herds. This better understanding of oestrus cycle control associated with suboptimal reproductive performance in dairy herds has led dairy producers to quickly adopt timed artificial insemination (AI) protocols. Recent surveys have documented that fixed-time AI has become an important component of management of reproduction in high-producing herds. Furthermore, timed AI protocols have also demonstrated benefits in pasture-based milk production systems because of the ability to increase insemination rate. In general, successful use of the Ovsynch protocol requires some fundamental physiological principles to be respected, including: induction of ovulation to synchronise follicle growth in the first 2 days of the programme such that a young antral follicle is recruited; maintenance of high concentrations of progesterone during the development of the ovulatory follicle, but also effectively lyse the corpus luteum to result in very low concentration of progesterone at AI; and having a healthy pre-ovulatory follicle of moderate diameter that is highly oestrogenic and responsive to gonadotropins to synchronously ovulate 12 to 18 h after insemination. Current methods oestrous and ovulation synchronisation are still not optimal and future improvements will likely require new technologies for hormone formulation and delivery such that additional interventions are minimised to maintain acceptance by producers.

  3. Synchronized reproduction promotes species coexistence through reproductive facilitation.

    PubMed

    Chen, Yu-Yun; Hsu, Sze-Bi

    2011-04-01

    Theories for species coexistence often emphasize niche differentiation and temporal segregation of recruitment to avoid competition. Recent work on mutualism suggested that plant species sharing pollinators provide mutual facilitation when exhibit synchronized reproduction. The facilitation on reproduction may enhance species persistence and coexistence. Theoretical ecologists paid little attention to such indirect mutualistic systems by far. We propose a new model for a two-species system using difference equations. The model focuses on adult plants and assumes no resource competition between these well-established individuals. Our formulas include demographic parameters, such as mortality and recruitment rates, and functions of reproductive facilitation. Both recruitment and facilitation effects reach saturation levels when flower production is at high levels. We conduct mathematical analyses to assess conditions of coexistence. We establish demographical conditions permitting species coexistence. Our analyses suggest a "rescue" effect from a "superior" species to a "weaker" species under strong recruitment enhancement effect when the later is not self-sustainable. The facilitation on rare species may help to overcome Allee effect.

  4. Assisted reproductive technologies in the reproductive management of small ruminants.

    PubMed

    Amiridis, G S; Cseh, S

    2012-02-01

    In modern agriculture, assisted reproductive technologies are being used for out of season oestrus induction, enhancement of reproductive performance and genetic improvement. In addition, they can have substantial contribution in preservation of endangered species or breeds, as well as in eradication programs of various diseases. While their applications are widespread in cattle, in small ruminants it is almost restricted to artificial insemination. The main limitations of a wider application in small ruminants are the naturally occurring anoestrus period, the variability of response to superovulatory treatments, the fertilisation failure and the need of surgery for collection and transfer of gametes and embryos. Nonetheless, during the last 30 years, considerable progress has been made in sheep and goat embryo technologies, especially in the fields of oestrus synchronisation, superovulation and in vitro embryo production. This paper reviews the status of assisted reproductive technologies in sheep, analysing the prospects offered by recent advances in in vivo and in vitro embryo production from mature and juvenile lambs. PMID:22381207

  5. Queen succession through asexual reproduction in termites.

    PubMed

    Matsuura, Kenji; Vargo, Edward L; Kawatsu, Kazutaka; Labadie, Paul E; Nakano, Hiroko; Yashiro, Toshihisa; Tsuji, Kazuki

    2009-03-27

    The evolution and maintenance of sexual reproduction may involve important tradeoffs because asexual reproduction can double an individual's contribution to the gene pool but reduces diversity. Moreover, in social insects the maintenance of genetic diversity among workers may be important for colony growth and survival. We identified a previously unknown termite breeding system in which both parthenogenesis and sexual reproduction are conditionally used. Queens produce their replacements asexually but use normal sexual reproduction to produce other colony members. These findings show how eusociality can lead to extraordinary reproductive systems and provide important insights into the advantages and disadvantages of sex.

  6. No intra-locus sexual conflict over reproductive fitness or ageing in field crickets.

    PubMed

    Zajitschek, Felix; Hunt, John; Zajitschek, Susanne R K; Jennions, Michael D; Brooks, Robert

    2007-01-01

    Differences in the ways in which males and females maximize evolutionary fitness can lead to intra-locus sexual conflict in which genes delivering fitness benefits to one sex are costly when expressed in the other. Trade-offs between current reproductive effort and future reproduction and survival are fundamental to the evolutionary biology of ageing. This leads to the prediction that sex differences in the optimization of age-dependent reproductive effort may generate intra-locus sexual conflict over ageing rates. Here we test for intra-locus sexual conflict over age-dependent reproductive effort and longevity in the black field cricket, Teleogryllus commodus. Using a half-sib breeding design, we show that the most important components of male and female reproductive effort (male calling effort and the number of eggs laid by females) were positively genetically correlated, especially in early adulthood. However, the genetic relationships between longevity and reproductive effort were different for males and females, leading to low genetic covariation between male and female longevity. The apparent absence of intra-locus sexual conflict over ageing suggests that male and female longevity can evolve largely independently of one another.

  7. The koala (Phascolarctos cinereus): a case study in the development of reproductive technology in a marsupial.

    PubMed

    Johnston, Stephen D; Holt, William V

    2014-01-01

    The successful development and application of an assisted breeding program in any animal relies primarily on a thorough understanding of the fundamental reproductive biology (anatomy, physiology and behaviour) of the species in question. Surely, the ultimate goal and greatest hallmark of such a program is the efficacious establishment of a series of reliable techniques that facilitate the reproductive and genetic management of fragmented populations, both in captivity and in the wild. Such an achievement is all the more challenging when the reproductive biology of that species is essentially rudimentary and without adequate reproductive models to compare to. Using the koala (Phascolarctos cinereus) as a case study, this chapter provides some personal insights into the evolution of a concept that began as a small undergraduate student project but that subsequently evolved into the first-ever successful artificial insemination of a marsupial. Apart from this historical perspective, we also provide a brief review of the current reproductive biology of the koala, discuss technical elements of current assisted breeding technology of this species, its potential application to the wombat, and the future role it might play in helping to conserve wild koala populations. There is little doubt that the unique reproductive biology and tractability of the koala has in this case been a benefit rather than a hindrance to the success of artificial breeding in this species.

  8. The koala (Phascolarctos cinereus): a case study in the development of reproductive technology in a marsupial.

    PubMed

    Johnston, Stephen D; Holt, William V

    2014-01-01

    The successful development and application of an assisted breeding program in any animal relies primarily on a thorough understanding of the fundamental reproductive biology (anatomy, physiology and behaviour) of the species in question. Surely, the ultimate goal and greatest hallmark of such a program is the efficacious establishment of a series of reliable techniques that facilitate the reproductive and genetic management of fragmented populations, both in captivity and in the wild. Such an achievement is all the more challenging when the reproductive biology of that species is essentially rudimentary and without adequate reproductive models to compare to. Using the koala (Phascolarctos cinereus) as a case study, this chapter provides some personal insights into the evolution of a concept that began as a small undergraduate student project but that subsequently evolved into the first-ever successful artificial insemination of a marsupial. Apart from this historical perspective, we also provide a brief review of the current reproductive biology of the koala, discuss technical elements of current assisted breeding technology of this species, its potential application to the wombat, and the future role it might play in helping to conserve wild koala populations. There is little doubt that the unique reproductive biology and tractability of the koala has in this case been a benefit rather than a hindrance to the success of artificial breeding in this species. PMID:25091911

  9. Reproductive Isolation during Domestication[W

    PubMed Central

    Dempewolf, Hannes; Hodgins, Kathryn A.; Rummell, Sonja E.; Ellstrand, Norman C.; Rieseberg, Loren H.

    2012-01-01

    It has been hypothesized that reproductive isolation should facilitate evolution under domestication. However, a systematic comparison of reproductive barrier strength between crops and their progenitors has not been conducted to test this hypothesis. Here, we present a systematic survey of reproductive barriers between 32 economically important crop species and their progenitors to better understand the role of reproductive isolation during the domestication process. We took a conservative approach, avoiding those types of reproductive isolation that are poorly known for these taxa (e.g., differences in flowering time). We show that the majority of crops surveyed are isolated from their progenitors by one or more reproductive barriers, despite the fact that the most important reproductive barrier in natural systems, geographical isolation, was absent, at least in the initial stages of domestication for most species. Thus, barriers to reproduction between crops and wild relatives are closely associated with domestication and may facilitate it, thereby raising the question whether reproductive isolation could be viewed as a long-overlooked “domestication trait.” Some of the reproductive barriers observed (e.g., polyploidy and uniparental reproduction), however, may have been favored for reasons other than, or in addition to, their effects on gene flow. PMID:22773750

  10. Fundamental Physics for Probing and Imaging

    NASA Astrophysics Data System (ADS)

    Allison, Wade

    2006-12-01

    This book addresses the question 'What is physics for?' Physics has provided many answers for mankind by extending his ability to see. Modern technology has enabled the power of physics to see into objects to be used in archaeology, medicine including therapy, geophysics, forensics and other spheres important to the good of society. The book looks at the fundamental physics of the various methods and how they are used by technology. These methods are magnetic resonance, ionising radiation and sound. By taking a broad view over the whole field it encourages comparisons, but also addresses questions of risk and benefit to society from a fundamental viewpoint. This textbook has developed from a course given to third year students at Oxford and is written so that it can be used coherently as a basis for shortened courses by omitting a number of chapters.

  11. Microbes Central to Human Reproduction

    PubMed Central

    Reid, Gregor; Brigidi, Patrizia; Burton, Jeremy P; Contractor, Nikhat; Duncan, Sylvia; Fargier, Emilie; Hill, Colin; Lebeer, Sarah; Martín, Rocio; McBain, Andrew J; Mor, Gil; O'Neill, Catherine; Rodríguez, Juan Miguel; Swann, Jonathan; van Hemert, Saskia; Ansell, Juliett

    2015-01-01

    As studies uncover the breadth of microbes associated with human life, opportunities will emerge to manipulate and augment their functions in ways that improve health and longevity. From involvement in the complexities of reproduction and fetal/infant development, to delaying the onset of disease, and indeed countering many maladies, microbes offer hope for human well-being. Evidence is emerging to suggest that microbes may play a beneficial role in body sites traditionally viewed as being sterile. Although further evidence is required, we propose that much of medical dogma is about to change significantly through recognition and understanding of these hitherto unrecognized microbe–host interactions. A meeting of the International Scientific Association for Probiotics and Prebiotics held in Aberdeen, Scotland (June 2014), presented new views and challenged established concepts on the role of microbes in reproduction and health of the mother and infant. This article summarizes some of the main aspects of these discussions. PMID:25250861

  12. Ginseng and male reproductive function

    PubMed Central

    Leung, Kar Wah; Wong, Alice ST

    2013-01-01

    Ginseng is often referred to as the King of all herbs, and is found to be a promising agent to improve general well-being. Ginseng has also been reputed as an aphrodisiac, and is used to treat sexual dysfunction as well as to enhance sexual behavior in traditional Chinese medical practices. Data from animal studies have shown a positive correlation among ginseng, libido, and copulatory performances, and these effects have been confirmed in case-control studies in human. In addition, ginseng is found to improve the sperm quality and count of healthy individuals as well as patients with treatment-related infertility. These actions are mostly attributed to ginsenosides, the major pharmacological active components of ginseng. This review compiles the current knowledge about the multifaceted effects of ginseng on male reproductive function, and also focuses on its mechanisms of action that may represent novel therapeutic strategies for the treatment of male reproductive diseases or disorders. PMID:24381805

  13. Men's reproductive and sexual health.

    PubMed

    Forrest, K A

    2001-05-01

    A broad definition of men's reproductive and sexual health (MRSH) includes medical (pathophysiological) matters such as sexually transmitted infections (STIs), developmental anomalies, malignancy, trauma, and infertility. It also includes psychosocial concerns: sexuality, contraception, disease prophylaxis, developmental and lifecycle issues, tobacco and drug use, sexual identity and orientation, and partnership issues. College men, of whom a large majority are sexually active, have a range of MRSH needs, including some that are particular to their age and social environment. To reach men effectively requires approaches that are somewhat different from those used with women. Clinicians in college health services are in an excellent position to help young men recognize the importance of reproductive health and sexual responsibility. College health services therefore should offer men screening; clinical diagnosis and treatment for MRSH conditions; and information, education, and counseling services, in a manner designed to meet their unique needs. PMID:11413943

  14. Parthenogenesis and Human Assisted Reproduction

    PubMed Central

    Bos-Mikich, Adriana; Bressan, Fabiana F.; Ruggeri, Rafael R.; Watanabe, Yeda; Meirelles, Flávio V.

    2016-01-01

    Parthenogenetic activation of human oocytes obtained from infertility treatments has gained new interest in recent years as an alternative approach to create embryos with no reproductive purpose for research in areas such as assisted reproduction technologies itself, somatic cell, and nuclear transfer experiments and for derivation of clinical grade pluripotent embryonic stem cells for regenerative medicine. Different activating methods have been tested on human and nonhuman oocytes, with varying degrees of success in terms of parthenote generation rates, embryo development stem cell derivation rates. Success in achieving a standardized artificial activation methodology for human oocytes and the subsequent potential therapeutic gain obtained from these embryos depends mainly on the availability of gametes donated from infertility treatments. This review will focus on the creation of parthenotes from clinically unusable oocytes for derivation and establishment of human parthenogenetic stem cell lines and their potential applications in regenerative medicine. PMID:26635881

  15. Microbes central to human reproduction.

    PubMed

    Reid, Gregor; Brigidi, Patrizia; Burton, Jeremy P; Contractor, Nikhat; Duncan, Sylvia; Fargier, Emilie; Hill, Colin; Lebeer, Sarah; Martín, Rocio; McBain, Andrew J; Mor, Gil; O'Neill, Catherine; Rodríguez, Juan Miguel; Swann, Jonathan; van Hemert, Saskia; Ansell, Juliett

    2015-01-01

    As studies uncover the breadth of microbes associated with human life, opportunities will emerge to manipulate and augment their functions in ways that improve health and longevity. From involvement in the complexities of reproduction and fetal/infant development, to delaying the onset of disease, and indeed countering many maladies, microbes offer hope for human well-being. Evidence is emerging to suggest that microbes may play a beneficial role in body sites traditionally viewed as being sterile. Although further evidence is required, we propose that much of medical dogma is about to change significantly through recognition and understanding of these hitherto unrecognized microbe-host interactions. A meeting of the International Scientific Association for Probiotics and Prebiotics held in Aberdeen, Scotland (June 2014), presented new views and challenged established concepts on the role of microbes in reproduction and health of the mother and infant. This article summarizes some of the main aspects of these discussions.

  16. Autoimmune diseases and reproductive aging

    PubMed Central

    Bove, Riley

    2013-01-01

    As the population ages, more individuals with autoimmune diseases are experiencing reproductive senescence. Understanding the impact of menopause and age-related androgen decline on disease onset and course, as well as the potential for hormonal interventions, is critically important. In men, lupus erythematosis (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS) are associated with lower androgen levels. However, the impact of age-related declines in testosterone, as well as of testosterone replacement, on disease course remains underexplored. In women, the course of all three diseases with onset after the age of menopause differs from that with onset before menopause. Early age at menopause is associated with increased disease risk, and after menopause, disease course changes in SLE and RA. Less is known about MS. This article summarizes what is known about the relationship between reproductive aging and autoimmune diseases in men and women, and highlights areas for further investigation. PMID:23522436

  17. Parthenogenesis and Human Assisted Reproduction.

    PubMed

    Bos-Mikich, Adriana; Bressan, Fabiana F; Ruggeri, Rafael R; Watanabe, Yeda; Meirelles, Flávio V

    2016-01-01

    Parthenogenetic activation of human oocytes obtained from infertility treatments has gained new interest in recent years as an alternative approach to create embryos with no reproductive purpose for research in areas such as assisted reproduction technologies itself, somatic cell, and nuclear transfer experiments and for derivation of clinical grade pluripotent embryonic stem cells for regenerative medicine. Different activating methods have been tested on human and nonhuman oocytes, with varying degrees of success in terms of parthenote generation rates, embryo development stem cell derivation rates. Success in achieving a standardized artificial activation methodology for human oocytes and the subsequent potential therapeutic gain obtained from these embryos depends mainly on the availability of gametes donated from infertility treatments. This review will focus on the creation of parthenotes from clinically unusable oocytes for derivation and establishment of human parthenogenetic stem cell lines and their potential applications in regenerative medicine. PMID:26635881

  18. [Medical genetics in reproductive medicine].

    PubMed

    Macek, M; Vilímová, S; Potuzníková, P; Yurov, Y; Vorsanova, S; Diblík, J; Krebsová, A; Machatková, M; Koudová, M; Alánová, R; Matĕjcková, M; Hladíková, E; Broucková, M; Hüttelová, R; Vincenciová, R; Paulasová, P; Brandjeská, M; Uhrová, E; Kratĕnová, A; Smetanová, I; Novotná, D; Chudoba, D; Kulovaný, E; Krutílková, V; Hromadníková, I; Mardesic, T; Macek, M

    2002-01-01

    Reproductive genetics (RG) is another new field of medical genetics, integrated with reproductive medicine, assisted reproduction and developmental genetic. RG is closely linked to the perioconceptional prevention, perinatology, ultrasound and biochemical screening in the end of the first and beginning of the second trimesters. RG is based on the system of specialized genetic counseling, clinical cytogenetics, molecular cytogenetics and molecular genetics to provide prefertilization, preimplantation and classical prenatal diagnosis in the Ist to IIIrd trimesters. Thus, RG is part of the fetal medicine and therapy. The six years experience with RG is summarized. A system of the specialized health care, organized, if possible in one integrated center of RG and reproductive medicine (RM) is presented. Reproductive medicine provides all necessary clinical gynecological and andrological surveillance, with assisted reproduction and further obstetrical ultrasound examinations, including nuchal translucency measurements and 2D, 3D ultrasound, echocardiography examinations, if indicated, as well as the invasive method of prenatal diagnosis and perinatology care. Specialized genetic counseling and cytogenetic analysis, if indicated, should be offered to all partners with reproductive disorders as well as to oocyte donors. Chromosome anomalies are disclosed in 6% of men with abnormal sperm analysis as well as in women with severe reproductive disorders. In males with severe oligo, azoospermia, the sperm aneuploidy analysis by molecular cytogenetic methods is recommended. Advised is also the molecular genetic detection of Y chromosome microdeletions, which is detected in 9% of our azoospermic men with deletions in AZFb region. CFTR gene mutations and intron 8 and 10 polymorphism examination is provided not only in men with obstructive azoospermia (CBAVD), but also if severe oligospermy with less than 1 x 10(6) sperm/ml is detected. Molecular genetic analysis of thrombophilic

  19. Young women's reproductive health survey.

    PubMed

    Lewis, H

    1987-08-12

    A survey of reproductive health issues was conducted on 15 year old Hutt Valley secondary school girls by means of a self-administered anonymous questionnaire. The prevalence of sexual intercourse in the sample was 29%. Sixteen percent of the sexually active respondents used no method of contraception. Knowledge of reproductive health facts and contraception was poor both amongst sexually experienced and inexperienced respondents. Twenty-six percent relied on peers for this information, with mothers, teachers and books being other important sources cited. Respondents requested more information on sexually transmitted diseases, contraception and sexual relationships. Most would like this information more readily accessible. Preferred sources of information mentioned were: parents, books, films/videos, family planning clinics and friends.

  20. Should Reproductive Medicine Be Harmonized within Europe?

    PubMed

    Flatscher-Thöni, Magdalena; Voithofer, Caroline

    2015-03-01

    The medical as well as societal developments in reproductive medicine and respectively artificial reproductive technologies have challenged lawmakers, courts, politicians, medical experts and society itself over the last decades. Challenges can be seen in cross-border reproductive care, equal access to reproductive care, social freezing, disposal of embryos, multiple implantation, homosexual parenthood or surrogacy. Since different regulatory regimes have been enacted throughout Europe (e.g. liberal system in Spain, restrictive system in Austria) to accommodate, limit and regulate reproductive issues, we are analysing the question, if reproductive medicine should be harmonized within Europe. Therefore we are not only discussing already existing approaches e.g. self-regulation, or minimal standards of safety and quality, but we are also scrutinizing the role of high courts, such as the European Court of Human Rights (EC HR) and international declarations and conventions. Concluding we are briefly sketching aspects of a proposal for a potential harmonisation of reproductive medicine in Europe. PMID:26387260

  1. DOE fundamentals handbook: Material science. Volume 1

    SciTech Connect

    Not Available

    1993-01-01

    The Mechanical Science Handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of mechanical components and mechanical science. The handbook includes information on diesel engines, heat exchangers, pumps, valves, and miscellaneous mechanical components. This information will provide personnel with a foundation for understanding the construction and operation of mechanical components that are associated with various DOE nuclear facility operations and maintenance.

  2. [Reduction of biology to fundamental physics].

    PubMed

    Okhonin, V A

    2001-01-01

    It was shown that, while interpreting life as a physical phenomenon, fundamental physics allows for the following alternatives: relativity of animate and inanimate upon canonical transformations; the impossibility of the change from animate to inanimate state of isolated systems; the abandonment of attempts to reduce biology to the physics of isolated systems. The possibility of reducing biology to phenomenological physics was considered. A number of equations for the general phenomenological dynamics of density matrix was proposed.

  3. Baryogenesis and its implications to fundamental physics

    SciTech Connect

    Yoshimura, M.

    2008-08-08

    In this talk I shall explain some basic concepts of baryogenesis and leptogenesis theory, and a new idea of experimental method of verification of fundamental ingredients of leptogenesis theory; the Majorana nature and the absolute magnitude of neutrino masses. Both of these are important to the quest of physics beyond the standard theory, and have far reaching implications irrespective of any particular medel of leptogenesis. If this new method works ideally, there is even a further possibility of detecting relic neutrinos.

  4. Fundamental plasma emission involving ion sound waves

    NASA Technical Reports Server (NTRS)

    Cairns, Iver H.

    1987-01-01

    The theory for fundamental plasma emission by the three-wave processes L + or - S to T (where L, S and T denote Langmuir, ion sound and transverse waves, respectively) is developed. Kinematic constraints on the characteristics and growth lengths of waves participating in the wave processes are identified. In addition the rates, path-integrated wave temperatures, and limits on the brightness temperature of the radiation are derived.

  5. DOE fundamentals handbook: Material science. Volume 1

    SciTech Connect

    Not Available

    1993-01-01

    This handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the structure and properties of metals. This volume contains the two modules: structure of metals (bonding, common lattic types, grain structure/boundary, polymorphis, alloys, imperfections in metals) and properties of metals (stress, strain, Young modulus, stress-strain relation, physical properties, working of metals, corrosion, hydrogen embrittlement, tritium/material compatibility).

  6. DOE fundamentals handbook: Mechanical science. Volume 2

    SciTech Connect

    Not Available

    1993-01-01

    The Mechanical Science Handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of mechanical components and mechanical science. The handbook includes information diesel engines, heat exchangers, pumps, valves, and miscellaneous mechanical components. This information will provide personnel with a foundation for understanding the construction and operation of mechanical components that are associated with various DOE nuclear facility operations and maintenance.

  7. Reproductive seasonality in the mare: neuroendocrine basis and pharmacologic control.

    PubMed

    Williams, G L; Thorson, J F; Prezotto, L D; Velez, I C; Cardoso, R C; Amstalden, M

    2012-08-01

    Reproductive seasonality in the mare is characterized by a marked decline in adenohypophyseal synthesis and secretion of LH beginning near the autumnal equinox. Thus, ovarian cycles have ceased in most mares by the time of the winter solstice. Endogenous reproductive rhythms in seasonal species are entrained or synchronized as a result of periodic environmental cues. In the horse, this cue is primarily day length. Hence, supplemental lighting schemes have been used managerially for decades to modify the annual timing of reproduction in the mare. Although a full characterization of the cellular and molecular bases of seasonal rhythms has not been realized in any species, many of their synaptic and humoral signaling pathways have been defined. In the mare, neuroendocrine-related studies have focused primarily on the roles of GnRH and interneuronal signaling pathways that subserve the GnRH system in the regulatory cascade. Recent studies have considered the role of a newly discovered neuropeptide, RF-related peptide 3 that could function to inhibit GnRH secretion or gonadotrope responsiveness. Although results that used native peptide sequences have been negative in the mare and mixed in all mammalian females, new studies that used an RFRP3 antagonist (RF9) in sheep are encouraging. Importantly, despite continuing deficits in some fundamental areas, the knowledge required to control seasonal anovulation pharmacologically has been available for >20 yr. Specifically, the continuous infusion of native GnRH is both reliable and efficient for accelerating reproductive transition and is uniquely applicable to the horse. However, its practical exploitation continues to await the development of a commercially acceptable delivery vehicle. PMID:22579068

  8. Optimising reproductive performance of beef cows and replacement heifers.

    PubMed

    Diskin, M G; Kenny, D A

    2014-05-01

    A reproductively efficient beef cow herd is fundamental to meeting the protein and specifically, red meat demand of an ever increasing global population. However, attaining a high level of reproductive efficiency is underpinned by producers being cognisant of and achieving many key targets throughout the production cycle and requires significant technical competency. The lifetime productivity of the beef bred female commences from the onset of puberty and will be dictated by subsequent critical events including age at first calving, duration of the postpartum interval for each successive calving, conception and pregnancy rate and ultimately manifested as length of intercalving intervals and number of calves weaned over her lifetime. Puberty in heifers is a consequence of the interactive effects of genetics and both pre- and post-weaning nutrition. Early onset of puberty is essential to achieving the first main reproductive target for beef cow herds; first calving at 2 years of age. In calved heifers and mature cows, the onset of ovarian activity, postpartum is a key event dictating the calving interval. Again, this will be the product mainly of prepartum nutrition, manifested through body condition and the strength of the maternal bond between cow and calf, though there is increasing evidence of a modest genetic influence on this trait. Following the initiation of postpartum ovarian cyclicity, conception and subsequent pregnancy rate is generally a function of bull fertility in natural service herds and heat detection and timing of insemination in herds bred through artificial insemination. Cows and heifers should be maintained on a steady plane of nutrition during the breeding season, but the contribution of significant excesses or deficiencies of nutrients including protein and trace elements is likely to be minor where adequate pasture is available. While, increased efforts are being made internationally to genetically identify and select for more reproductively

  9. Optimising reproductive performance of beef cows and replacement heifers.

    PubMed

    Diskin, M G; Kenny, D A

    2014-05-01

    A reproductively efficient beef cow herd is fundamental to meeting the protein and specifically, red meat demand of an ever increasing global population. However, attaining a high level of reproductive efficiency is underpinned by producers being cognisant of and achieving many key targets throughout the production cycle and requires significant technical competency. The lifetime productivity of the beef bred female commences from the onset of puberty and will be dictated by subsequent critical events including age at first calving, duration of the postpartum interval for each successive calving, conception and pregnancy rate and ultimately manifested as length of intercalving intervals and number of calves weaned over her lifetime. Puberty in heifers is a consequence of the interactive effects of genetics and both pre- and post-weaning nutrition. Early onset of puberty is essential to achieving the first main reproductive target for beef cow herds; first calving at 2 years of age. In calved heifers and mature cows, the onset of ovarian activity, postpartum is a key event dictating the calving interval. Again, this will be the product mainly of prepartum nutrition, manifested through body condition and the strength of the maternal bond between cow and calf, though there is increasing evidence of a modest genetic influence on this trait. Following the initiation of postpartum ovarian cyclicity, conception and subsequent pregnancy rate is generally a function of bull fertility in natural service herds and heat detection and timing of insemination in herds bred through artificial insemination. Cows and heifers should be maintained on a steady plane of nutrition during the breeding season, but the contribution of significant excesses or deficiencies of nutrients including protein and trace elements is likely to be minor where adequate pasture is available. While, increased efforts are being made internationally to genetically identify and select for more reproductively

  10. Chemosignals, Hormones and Mammalian Reproduction

    PubMed Central

    Petrulis, Aras

    2013-01-01

    Many mammalian species use chemosignals to coordinate reproduction by altering the physiology and behavior of both sexes. Chemosignals prime reproductive physiology so that individuals become sexually mature and active at times when mating is most probable and suppress it when it is not. Once in reproductive condition, odors produced and deposited by both males and females are used to find and select individuals for mating. The production, dissemination and appropriate responses to these cues are modulated heavily by organizational and activational effects of gonadal sex steroids and thereby intrinsically link chemical communication to the broader reproductive context. Many compounds have been identified as “pheromones” but very few have met the expectations of that term: a unitary, species-typical substance that is both necessary and sufficient for an experience-independent behavioral or physiological response. In contrast, most responses to chemosignals are dependent or heavily modulated by experience, either in adulthood or during development. Mechanistically, chemosignals are perceived by both main and accessory (vomeronasal) olfactory systems with the importance of each system tied strongly to the nature of the stimulus rather than to the response. In the central nervous system, the vast majority of responses to chemosignals are mediated by cortical and medial amygdala connections with hypothalamic and other forebrain structures. Despite the importance of chemosignals in mammals, many details of chemical communication differ even among closely related species and defy clear categorization. Although generating much research and public interest, strong evidence for the existence of a robust chemical communication among humans is lacking. PMID:23545474

  11. Ethics and the reproductive process.

    PubMed

    Petrick, T J

    1990-01-01

    Changes in reproductive technology and contraceptive availability have resulted in ethical reconsiderations in many countries. The United States has been no exception. A discussion of the applicable ethical principles for contraceptive research and family planning programs is presented. Each country must decide its own individual response to a given ethical problem. The paper does not propose solutions but is designed to raise the necessary questions.

  12. Origins of Eukaryotic Sexual Reproduction

    PubMed Central

    2014-01-01

    Sexual reproduction is a nearly universal feature of eukaryotic organisms. Given its ubiquity and shared core features, sex is thought to have arisen once in the last common ancestor to all eukaryotes. Using the perspectives of molecular genetics and cell biology, we consider documented and hypothetical scenarios for the instantiation and evolution of meiosis, fertilization, sex determination, uniparental inheritance of organelle genomes, and speciation. PMID:24591519

  13. Fundamental Processes in Plasmas. Final report

    SciTech Connect

    O'Neil, Thomas M.; Driscoll, C. Fred

    2009-11-30

    This research focuses on fundamental processes in plasmas, and emphasizes problems for which precise experimental tests of theory can be obtained. Experiments are performed on non-neutral plasmas, utilizing three electron traps and one ion trap with a broad range of operating regimes and diagnostics. Theory is focused on fundamental plasma and fluid processes underlying collisional transport and fluid turbulence, using both analytic techniques and medium-scale numerical simulations. The simplicity of these systems allows a depth of understanding and a precision of comparison between theory and experiment which is rarely possible for neutral plasmas in complex geometry. The recent work has focused on three areas in basic plasma physics. First, experiments and theory have probed fundamental characteristics of plasma waves: from the low-amplitude thermal regime, to inviscid damping and fluid echoes, to cold fluid waves in cryogenic ion plasmas. Second, the wide-ranging effects of dissipative separatrices have been studied experimentally and theoretically, finding novel wave damping and coupling effects and important plasma transport effects. Finally, correlated systems have been investigated experimentally and theoretically: UCSD experients have now measured the Salpeter correlation enhancement, and theory work has characterized the 'guiding center atoms of antihydrogen created at CERN.

  14. Fundamentals of Physics, Extended 7th Edition

    NASA Astrophysics Data System (ADS)

    Halliday, David; Resnick, Robert; Walker, Jearl

    2004-05-01

    No other book on the market today can match the 30-year success of Halliday, Resnick and Walker's Fundamentals of Physics! Fundamentals of Physics, 7th Edition and the Extended Version, 7th Edition offer a solid understanding of fundamental physics concepts, helping readers apply this conceptual understanding to quantitative problem solving, in a breezy, easy-to-understand style. A unique combination of authoritative content and stimulating applications. * Numerous improvements in the text, based on feedback from the many users of the sixth edition (both instructors and students) * Several thousand end-of-chapter problems have been rewritten to streamline both the presentations and answers * 'Chapter Puzzlers' open each chapter with an intriguing application or question that is explained or answered in the chapter * Problem-solving tactics are provided to help beginning Physics students solve problems and avoid common error * The first section in every chapter introduces the subject of the chapter by asking and answering, "What is Physics?" as the question pertains to the chapter * Numerous supplements available to aid teachers and students The extended edition provides coverage of developments in Physics in the last 100 years, including: Einstein and Relativity, Bohr and others and Quantum Theory, and the more recent theoretical developments like String Theory.

  15. The roles of the immune system in women's reproduction: evolutionary constraints and life history trade-offs.

    PubMed

    Abrams, Elizabeth T; Miller, Elizabeth M

    2011-01-01

    Life history theory posits that, as long as survival is assured, finite resources are available for reproduction, maintenance, and growth/storage. To maximize lifetime reproductive success, resources are subject to trade-offs both within individuals and between current and future investment. For women, reproducing is costly and time-consuming; the bulk of available resources must be allocated to reproduction at the expense of more flexible systems like immune function. When reproducing women contract infectious diseases, the resources required for immune activation can fundamentally shift the patterns of resource allocation. Adding to the complexity of the reproductive-immune trade-offs in women are the pleiotropic effects of many immune factors, which were modified to serve key roles in mammalian reproduction. In this review, we explore the complex intersections between immune function and female reproduction to situate proximate immunological processes within a life history framework. After a brief overview of the immune system, we discuss some important physiological roles of immune factors in women's reproduction and the conflicts that may arise when these factors must play dual roles. We then discuss the influence of reproductive-immune trade-offs on the patterning of lifetime reproductive success: (1) the effect of immune activation/infectious disease on the timing of life history events; (2) the role of the immune system, immune activation, and infectious disease on resource allocation within individual reproductive events, particularly pregnancy; and (3) the role of the immune system in shaping the offspring's patterns of future life history trade-offs. We close with a discussion of future directions in reproductive immunology for anthropologists.

  16. Effective use of assisted reproduction.

    PubMed

    Bhattacharya, Siladitya

    2003-05-01

    Subfertility affects one in seven couples in the western world. Although the availability of assisted reproduction has changed the outlook for many childless couples, the procedures themselves have far-reaching implications in terms of invasiveness, acceptability and cost. There is now greater awareness that effective care involves using treatments that combine efficacy, appropriateness and efficiency with safety. Randomized trials addressing assisted reproduction are few and generally tend to suffer from a number of methodological inadequacies. Although IVF continues to be the treatment of choice for couples with persistent infertility, there is currently insufficient evidence from trial data to indicate that IVF is more effective than the other treatment options available for unexplained infertility. Intracytoplasmic sperm injection is beneficial in severe male factor infertility but is not warranted in other situations. There is an urgent need to focus on developing strategies to improve success rates of assisted reproduction and minimize the side-effects such as ovarian hyperstimulation and multiple pregnancy. Multiple pregnancy is the most common major complication of IVF and has a profound effect on maternal and neonatal morbidity as well as health service costs. PMID:12869781

  17. Seasonal Time Measurement During Reproduction

    PubMed Central

    IKEGAMI, Keisuke; YOSHIMURA, Takashi

    2013-01-01

    Abstract Most species living outside the tropical zone undergo physiological adaptations to seasonal environmental changes and changing day length (photoperiod); this phenomenon is called photoperiodism. It is well known that the circadian clock is involved in the regulation of photoperiodism such as seasonal reproduction, but the mechanism underlying circadian clock regulation of photoperiodism remains unclear. Recent molecular analysis have revealed that, in mammals and birds, the pars tuberalis (PT) of the pituitary gland acts as the relay point from light receptors, which receive information about the photoperiod, to the endocrine responses. Long-day (LD)-induced thyroid-stimulating hormone (TSH) in the PT acts as a master regulator of seasonal reproduction in the ependymal cells (ECs) within the mediobasal hypothalamus (MBH) and activates thyroid hormone (TH) by inducing the expression of type 2 deiodinase in both LD and short-day (SD) breeding animals. Furthermore, the circadian clock has been found to be localized in the PT and ECs as well as in the circadian pacemaker(s). This review purposes to summarize the current knowledge concerning the involvement of the neuroendocrine system and circadian clock in seasonal reproduction. PMID:23965600

  18. Possibilities with today's reproductive technologies.

    PubMed

    Johnson, S K

    2005-08-01

    Reproductive efficiency is critical to economic viability for cow/calf producers; however, very few producers take advantage of available reproductive technologies that can increase profitability. Today, more opportunities are available for producers who want to capture value from known genetics. Through the use of artificial insemination (AI), the average producer has access to a wide range of high-accuracy sires that can be selected to match production goals. Systems to synchronize estrus and ovulation can now produce pregnancy rates to a single fixed-timed AI that are 10-15% greater than those of the previous generation. Increased age and weight of calves at weaning is sufficient in some situations to pay for the cost of synchronization and AI. As a result of synchronization, more cows calve early the next year and in subsequent years of synchronization. The breeding season can be shortened without reducing end-of-season pregnancy rates, since synchronized cows have one more chance to conceive than unsynchronized cows in a 22-25 day interval. Cow nutrition can be more economically and precisely managed with a shorter breeding period. Producers that establish AI programs now will be prepared to take advantage of newly identified superior genetics or other technologies, e.g. sexed semen, when they become available. Trends towards more value-based marketing and improvements in pregnancy rates from synchronization systems, make this a key time to be aware of the possibilities using reproductive technologies. PMID:16002131

  19. Reproductive effects of alternative disinfectants

    SciTech Connect

    Carlton, B.D.; Barlett, P.; Basaran, A.; Colling, K.; Osis, I.; Smith, M.K.

    1986-11-01

    Organohalides formed through the reaction of chlorine and organic compounds in natural and waste waters pose potential health hazards. For this reason, alternative water disinfectants that do not form organohalides are being investigated with great interest. In this laboratory, the authors have examined the reproductive effects of chloramine and chlorine administered by gavage in Long-Evans rats. Animals were treated for a total of 66 to 76 days. Males were treated for 56 days and females for 14 days prior to breeding and throughout the 10-day breeding period. Females were treated throughout gestation and lactation. Following breeding, the males were necropsied and evaluated for sperm parameters and reproductive tract histopathology. Adult females and some pups were necropsied at weaning on postnatal day 21. Other pups were treated postweaning until 28 or 40 days of age. These pups were evaluated for the day of vaginal patency and thyroid hormone levels. No differences were observed between control rats and those rats exposed to up to 5 mg/kg/day chlorine or 10 mg/kg/day chloramine when fertility, viability, litter size, day of eye opening, or day of vaginal patency were evaluated. No alterations in sperm count, sperm direct progressive movement percent motility, or sperm morphology were observed among adult male rats. In addition, male and female reproductive organ weights were comparable to their respective control groups, and no significant histopathologic changes were observed among chlorine- or chloramine-treated male and female rats.

  20. Vitamin D and male reproduction.

    PubMed

    Blomberg Jensen, Martin

    2014-03-01

    Vitamin D is a versatile signalling molecule with a well-established role in the regulation of calcium homeostasis and bone health. The spectrum of vitamin D target organs has expanded and the reproductive role of vitamin D is highlighted by expression of the vitamin D receptor (VDR) and enzymes that metabolize vitamin D in testis, male reproductive tract and human spermatozoa. The expression levels of VDR and CYP24A1 in human spermatozoa serve as positive predictive markers of semen quality, and VDR mediates a nongenomic increase in intracellular calcium concentration that induces sperm motility. Interestingly, functional animal models show that vitamin D is important for estrogen signalling and sperm motility, while cross-sectional studies support the positive association between serum 25-hydroxyvitamin D level and sperm motility in both fertile and infertile men. Expression of VDR and enzymes that metabolize vitamin D in fetal testis indicates a yet unknown role during development, which may be extrapolated from invasive testicular germ cell tumours where 1α,25-dihydroxyvitamin D induces a mesodermal differentiation of the pluripotent testicular cancer cells. Taken together, vitamin D signalling has a positive effect on semen quality, increases estrogen responsiveness and differentiates germ cell tumours. Future studies are needed to determine when 1α,25-dihydroxyvitamin D acts in a paracrine manner and whether systemic changes, which are subject to pharmacological modulation, could influence male reproductive function.

  1. Introduction: Microbiome in human reproduction.

    PubMed

    Franasiak, Jason M; Scott, Richard T

    2015-12-01

    The human microbiome has been termed the "second human genome" and data that has come about of late certainly makes it appear every bit as complex. The human body contains 10-fold more microbial cells than the human cells and accounts for 1%-3% of our total body mass. As we learn more about this symbiotic relationship, it appears this complex interaction occurs in nearly every part of the body, even those areas at one time considered to be sterile. Indeed, the microbiome in human reproduction has been investigated in terms of both the lower and upper reproductive tract and includes interactions even at the point of gametogenesis. What is all the more fascinating is that we have known about the importance of microbes for over 150 years, even before they existed in name. And now, with the assistance of an exciting technologic revolution which has pushed forward our understanding of the microbiome, we appear to stand on the precipice of a higher level of understanding of microbes, the biofilms they create, and their impact of health and disease in human reproduction.

  2. Spatial processing in color reproduction

    NASA Astrophysics Data System (ADS)

    Liu, Li; Yang, Yongyi; Stark, Henry

    2005-08-01

    We consider the reproduction of color subject to material and neighborhood constraints. By 'material constraints,' we mean any constraints that are applied to the amount of ink, lights, voltages, and currents that are used in the generation of color. In the first instance we consider the problem of reproducing a target color constrained by maximum additive color signals, such as in the phosphorescence process in a cathode ray tube. In the second instance we consider the more difficult problem of reproducing color subject to constraints on the maximum primary color variations in a (spatial) neighborhood. We introduce the idea of adjacent color variance (ACV) and then attempt to reproduce colors subject to an upper bound on the ACV. An algorithm that is suitable for this task is the method of vector space projections (VSP). In order to use VSP for constrained color reproduction, we use a novel approach to linearize nonlinear CIE-Lab space constraints. Experimental results are furnished that demonstrate that using the ACV as a bound helps to reduce reproduction artifacts in a color image.

  3. Transgenerational neuroendocrine disruption of reproduction

    PubMed Central

    Walker, Deena M.; Gore, Andrea C.

    2014-01-01

    Exposure to endocrine disrupting chemicals (EDCs) is associated with dysfunctions of metabolism, energy balance, thyroid function and reproduction, and an increased risk of endocrine cancers. These multifactorial disorders can be ‘programmed’ through molecular epigenetic changes induced by exposure to EDCs early in life, the expression of which may not manifest until adulthood. In some cases, EDCs have detrimental effects on subsequent generations, which indicates that traits for disease predisposition may be passed to future generations by nongenomic inheritance. This Review discusses current understanding of the epigenetic mechanisms that underlie sexual differentiation of reproductive neuroendocrine systems in mammals and summarizes the literature on transgenerational epigenetic effects of representative EDCs: vinclozolin, diethylstilbesterol, bisphenol A and polychlorinated biphenyls. The article differentiates between context-dependent epigenetic transgenerational changes—namely, those that require environmental exposure, either via the EDC itself or through behavioral or physiological differences in parents—and germline-dependent epigenetic mechanisms. These processes, albeit discrete, are not mutually exclusive and can involve similar molecular mechanisms including DNA methylation and histone modifications and may predispose exposed individuals to transgenerational disruption of reproductive processes. New insights stress the crucial need to develop a clear understanding of how EDCs may program the epigenome of exposed individuals and their descendants. PMID:21263448

  4. Fundamental Physics Explored with High Intensity Laser

    NASA Astrophysics Data System (ADS)

    Tajima, T.; Homma, K.

    2012-10-01

    Over the last century the method of particle acceleration to high energies has become the prime approach to explore the fundamental nature of matter in laboratory. It appears that the latest search of the contemporary accelerator based on the colliders shows a sign of saturation (or at least a slow-down) in increasing its energy and other necessary parameters to extend this frontier. We suggest two pronged approach enabled by the recent progress in high intensity lasers. First we envision the laser-driven plasma accelerator may be able to extend the reach of the collider. For this approach to bear fruit, we need to develop the technology of high averaged power laser in addition to the high intensity. For this we mention that the latest research effort of ICAN is an encouraging sign. In addition to this, we now introduce the concept of the noncollider paradigm in exploring fundamental physics with high intensity (and large energy) lasers. One of the examples we mention is the laser wakefield acceleration (LWFA) far beyond TeV without large luminosity. If we relax or do not require the large luminosity necessary for colliders, but solely in ultrahigh energy frontier, we are still capable of exploring such a fundamental issue. Given such a high energetic particle source and high-intensity laser fields simultaneously, we expect to be able to access new aspects on the matter and the vacuum structure from fundamental physical point of views. LWFA naturally exploits the nonlinear optical effects in the plasma when it becomes of relativistic intensity. Normally nonlinear optical effects are discussed based upon polarization susceptibility of matter to external fields. We suggest application of this concept even to the vacuum structure as a new kind of order parameter to discuss vacuum-originating phenomena at semimacroscopic scales. This viewpoint unifies the following observables with the unprecedented experimental environment we envision; the dispersion relation of

  5. Reproductive Steroid Regulation of Mood and Behavior.

    PubMed

    Schiller, Crystal Edler; Johnson, Sarah L; Abate, Anna C; Rubinow, David R; Schmidt, Peter J

    2016-01-01

    In this article, we examine evidence supporting the role of reproductive steroids in the regulation of mood and behavior in women and the nature of that role. In the first half of the article, we review evidence for the following: (i) the reproductive system is designed to regulate behavior; (ii) from the subcellular to cellular to circuit to behavior, reproductive steroids are powerful neuroregulators; (iii) affective disorders are disorders of behavioral state; and (iv) reproductive steroids affect virtually every system implicated in the pathophysiology of depression. In the second half of the article, we discuss the diagnosis of the three reproductive endocrine-related mood disorders (premenstrual dysphoric disorder, postpartum depression, and perimenopausal depression) and present evidence supporting the relevance of reproductive steroids to these conditions. Existing evidence suggests that changes in reproductive steroid levels during specific reproductive states (i.e., the premenstrual phase of the menstrual cycle, pregnancy, parturition, and the menopause transition) trigger affective dysregulation in susceptible women, thus suggesting the etiopathogenic relevance of these hormonal changes in reproductive mood disorders. Understanding the source of individual susceptibility is critical to both preventing the onset of illness and developing novel, individualized treatments for reproductive-related affective dysregulation. © 2016 American Physiological Society. Compr Physiol 6:1135-1160, 2016e. PMID:27347888

  6. Times of danger: embryos, sperm and precarious reproduction ca. 1870s-1910s.

    PubMed

    Kampf, Antje

    2015-03-01

    This paper discusses the rise and fall of the theory of paternal transmission, drawing attention to the hitherto underresearched debates about the importance and impact of male-mediated harm to the embryo in reproduction that peaked around the turn of the twentieth century. The focus is on the implications of the twin "great social evils," syphilis and alcohol, which converged at the time of a general transformation of medicine into experimental science and a concomitant rise in new concepts of heredity. Looking at the way in which the issue of time added to profound changes which were linked to particular visions of society and changes in the politics of gender at the turn of the century, I examine the asymmetrical relationship of sociopolitical and epistemological dimensions of time and reproduction. The paper shows how these debates were positioned within the wider context of eugenics and in relation to concepts of male reproduction that involved fundamental political, social and moral dimensions.

  7. Times of danger: embryos, sperm and precarious reproduction ca. 1870s-1910s.

    PubMed

    Kampf, Antje

    2015-03-01

    This paper discusses the rise and fall of the theory of paternal transmission, drawing attention to the hitherto underresearched debates about the importance and impact of male-mediated harm to the embryo in reproduction that peaked around the turn of the twentieth century. The focus is on the implications of the twin "great social evils," syphilis and alcohol, which converged at the time of a general transformation of medicine into experimental science and a concomitant rise in new concepts of heredity. Looking at the way in which the issue of time added to profound changes which were linked to particular visions of society and changes in the politics of gender at the turn of the century, I examine the asymmetrical relationship of sociopolitical and epistemological dimensions of time and reproduction. The paper shows how these debates were positioned within the wider context of eugenics and in relation to concepts of male reproduction that involved fundamental political, social and moral dimensions. PMID:26013436

  8. 32 CFR 2001.16 - Fundamental classification guidance review.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Fundamental classification guidance review. 2001... INFORMATION Classification § 2001.16 Fundamental classification guidance review. (a) Performance of fundamental classification guidance reviews. An initial fundamental classification guidance review shall...

  9. Model for a fundamental theory with supersymmetry

    NASA Astrophysics Data System (ADS)

    Yokoo, Seiichiro

    Physics in the year 2006 is tightly constrained by experiment, observation, and mathematical consistency. The Standard Model provides a remarkably precise description of particle physics, and general relativity is quite successful in describing gravitational phenomena. At the same time, it is clear that a more fundamental theory is needed for several distinct reasons. Here we consider a new approach, which begins with the unusually ambitious point of view that a truly fundamental theory should aspire to explaining the origins of Lorentz invariance, gravity, gauge fields and their symmetry, supersymmetry, fermionic fields, bosonic fields, quantum mechanics and spacetime. The present dissertation is organized so that it starts with the most conventional ideas for extending the Standard Model and ends with a microscopic statistical picture, which is actually the logical starting point of the theory, but which is also the most remote excursion from conventional physics. One motivation for the present work is the fact that a Euclidean path integral in quantum physics is equivalent to a partition function in statistical physics. This suggests that the most fundamental description of nature may be statistical. This dissertation may be regarded as an attempt to see how far one can go with this premise in explaining the observed phenomena, starting with the simplest statistical picture imaginable. It may be that nature is richer than the model assumed here, but the present results are quite suggestive, because, with a set of assumptions that are not unreasonable, one recovers the phenomena listed above. At the end, the present theory leads back to conventional physics, except that Lorentz invariance and supersymmetry are violated at extremely high energy. To be more specific, one obtains local Lorentz invariance (at low energy compared to the Planck scale), an SO( N) unified gauge theory (with N = 10 as the simplest possibility), supersymmetry of Standard Model fermions and

  10. [Relation between fundamental and realized ecological niche].

    PubMed

    Severtsov, A S

    2012-01-01

    Since species are formed in course of evolutionary process, their ecological niches are formed in the evolutionary process, too. Species exist in a state of evolutionary stasis diring hundreds of thousands and millions years. Stasis in sustained mainly by counterbalance of vectors of directional selection. Niche can be viewed as a multidimensional structure. Multitude of environmental factors acts upon every population, which cause elimination and, by that, selection for adaptation to each eliminating factor. Different directions of these vectors of selection lead to their counteractions; selection in one direction is interfered by selection in an opposite direction. The counterbalance of vectors of selection interferes with progressive evolution thus supporting stasis. During species existence in a stasis condition it endures a whole set of various deterioration of environment. Such deteriorations lead to imbalance of selective processes. Unbalanced vectors of selection form adaptations to extreme conditions of existence. Such adaptations are superfluous as for usual conditions; but they define fitness borders and, by that, borders of a fundamental niche. Realized niche, as well as fundamental one, is a multidimensional structure. Each population occupies a subniche of the specific realized niche. Thus, it occupies habitats where conditions are as close to an ecological optimum as can be admitted by the conditions in the given part of the areal. The sum of all subniches of populations--the specific realized niche--coincides with a part of fundamental niche because only the part of adaptive possibilities of a species sufficient for existence in the given environment is used. Interspecific competition, even when it is capable to restrict consumption of limiting resources, is not the reason of the realized niche limitation. Restriction of one or two of niche parameters does not influece all others parameters of its multidimensional space.

  11. 146 Kepler-Lamost targets fundamental parameters

    NASA Astrophysics Data System (ADS)

    Wu, Yaqian

    2015-08-01

    Accurate stellar fundamental parameters with high precision are important for distinguishing stellar populationand star study.Turn-off stars are in the relatively vital stellar evolution state. Studying turn-off stars can help us to have a more comprehensive understand of the stellar physics.With the help of observation provided by Lamost project, we obtain atmospheric parameters of 146 turn-off stars from LSP3 pipeline. Combined with stellar pulsation data from Kepler, we can get asteroseismic characteristic of stars,such as Δν and νmax.In this paper,we constructed a grid of evolutionary models, with the mass range from 0.8 to 2.5 M⊙ and metallicities Zini = 0.0085, 0.0105, 0.0130, 0.0165, 0.0200, 0.0250, 0.0300, 0.0400 (i.e.[Fe/H] from -0.3 to 0.4dex).All evolutionary tracks were started in the pre-main sequence birth line and ended at the base of Red Giant Branch.Based on the stellar model grid we constructed,as well as Kepler-Lamost observations, we obtained fundamental parameters of 146 around turn-off stars, and found that 112 targets lied in turn-off state or in the Main Sequence,15 targets are subgiant stars and 7 targets have evolved to the red giants stage.Then we use pulsation code(JIG) of Guenther to extract theorical individual frequencies and calculate theorical Δν.Meanwhile we obtained more precise fundamental parameters of these stars.

  12. Fundamentals of air pollution. Third edition

    SciTech Connect

    Boubel, R.W.; Fox, D.L.; Turner, D.B.; Stern, A.C.

    1994-12-31

    This book presents an overview of air pollution. In Part I, the history of air pollution and the basic concepts involved with air pollution such as sources, scales, definitions are covered. Part II describes how airborne pollutants damage materials, vegetation, animals, and humans. Six fundamental aspects of air pollution are included in the text: The Elements of Air Pollution; The Effects of Air Pollution; Measurement and Monitoring of Air Pollution; Meterology of Air Pollution; regulatory Control of Air Pollution; and Engineering Control of Air Pollution.

  13. Fundamental investigation of duct/ESP phenomena

    SciTech Connect

    Brown, C.A. ); Durham, M.D. ); Sowa, W.A. . Combustion Lab.); Himes, R.M. ); Mahaffey, W.A. )

    1991-10-21

    Radian Corporation was contracted to investigate duct injection and ESP phenomena in a 1.7 MW pilot plant constructed for this test program. This study was an attempt to resolve problems found in previous studies and answer remaining questions for the technology using an approach which concentrates on the fundamental mechanisms of the process. The goal of the study was to obtain a better understanding of the basic physical and chemical phenomena that control: (1) the desulfurization of flue gas by calcium-based reagent, and (2) the coupling of an existing ESP particulate collection device to the duct injection process. Process economics are being studied by others. (VC)

  14. Development of Fundamental Technologies for Micro Bioreactors

    NASA Astrophysics Data System (ADS)

    Sato, Kiichi; Kitamori, Takehiko

    This chapter reviews the development of fundamental technologies required for microchip-based bioreactors utilizing living mammalian cells and pressure driven flow. The most important factor in the bioreactor is the cell culture. For proper cell culturing, continuous medium supply from a microfluidic channel and appropriate modification of the channel surface to accommodate cell attachment is required. Moreover, the medium flow rate should be chosen carefully, because shear stress affects cell activity. The techniques presented here could be applied to the development of micro bioreactors such as microlivers, pigment production by plant cells, and artificial insemination.

  15. Fundamental studies of passivity and passivity breakdown

    SciTech Connect

    Macdonald, D.D.; Urquidi-Macdonald, M.; Song, H.; Biaggio-Rocha, S.; Searson, P.

    1991-11-01

    This report summarizes the findings of our fundamental research program on passivity and passivity breakdown. During the past three and one half years in this program (including the three year incrementally-funded grant prior to the present grant), we developed and experimentally tested various physical models for the growth and breakdown of passive films on metal surfaces. These models belong to a general class termed point defects models'' (PDMs), in which the growth and breakdown of passive films are described in terms of the movement of anion and cation vacancies.

  16. Fundamental science of nanometer-size clusters

    SciTech Connect

    Wilcoxon, J.P.; Newcomer, P.P.; Samara, G.A.; Venturini, E.L.; Williamson, R.L.

    1995-10-01

    This research has produced a variety of monodisperse, nanometer-size clusters (nanoclusters for short), characterized their size and crystal structure and developed a scientific understanding of the size dependence of their physical properties. Of specific interest were the influence of quantum electronic confinement on the optical properties, magnetic properties, and dielectric properties. These properties were chosen both for their potential practical impact on various applications identified in the National Critical Technologies list (e.g., catalysis, information storage, sensors, environmental remediation, ...) as well as for their importance to the fundamental science of clusters. An Executive Summary provides a description of the major highlights.

  17. Antennas in matter: Fundamentals, theory, and applications

    NASA Technical Reports Server (NTRS)

    King, R. W. P.; Smith, G. S.; Owens, M.; Wu, T. T.

    1981-01-01

    The volume provides an introduction to antennas and probes embedded within or near material bodies such as the earth, the ocean, or a living organism. After a fundamental analysis of insulated and bare antennas, an advanced treatment of antennas in various media is presented, including a detailed study of the electromagnetic equations in homogeneous isotropic media, the complete theory of the bare dipole in a general medium, and a rigorous analysis of the insulated antenna as well as bare and insulated loop antennas. Finally, experimental models and measuring techniques related to antennas and probes in a general dissipative or dielectric medium are examined.

  18. Fundamental Limits of Spatial Resolution in PET

    PubMed Central

    Moses, William W.

    2010-01-01

    The fundamental limits of spatial resolution in positron emission tomography (PET) have been understood for many years. The physical size of the detector element usually plays the dominant role in determining resolution, but the combined contributions from acollinearity, positron range, penetration into the detector ring, and decoding errors in the detector modules often combine to be of similar size. In addition, the sampling geometry and statistical noise further degrade the effective resolution. This paper describes quantitatively describes these effects, discusses potential methods for reducing the magnitude of these effects, and computes the ultimately achievable spatial resolution for clinical and pre-clinical PET cameras. PMID:21804677

  19. Fundamental Structure of Matter and Strong Interaction

    SciTech Connect

    Jian-Ping Chen

    2011-11-01

    More than 99% of the visible matter in the universe are the protons and neutrons. Their internal structure is mostly governed by the strong interaction. Understanding their internal structure in terms of fundamental degrees-of-freedom is one of the most important subjects in modern physics. Worldwide efforts in the last few decades have lead to numerous surprises and discoveries, but major challenges still remain. An overview of the progress will be presented with a focus on the recent studies of the proton and neutron's electromagnetic and spin structure. Future perspectives will be discussed.

  20. Fundamental bioprocessing research for coal applications

    SciTech Connect

    Kaufman, E.N.

    1996-06-01

    The purpose of this program is to gain a fundamental understanding and sound scientific technical basis for evaluating the potential roles of innovative bioprocessing concepts for the utilization and conversion of coal. The aim is to explore the numerous ways in which advanced biological processes and techniques can open new opportunities for coal utilization or can replace more conventional techniques by use of milder conditions with less energy consumption or loss. There are several roles where biotechnology is likely to be important in coal utilization and conversion. These include potential bioprocessing systems such.

  1. Fundamental constraints on two-time physics

    NASA Astrophysics Data System (ADS)

    Piceno, E.; Rosado, A.; Sadurní, E.

    2016-10-01

    We show that generalizations of classical and quantum dynamics with two times lead to a fundamentally constrained evolution. At the level of classical physics, Newton's second law is extended and exactly integrated in a (1 + 2) -dimensional space, leading to effective single-time evolution for any initial condition. The cases 2 + 2 and 3 + 2 are also analyzed. In the domain of quantum mechanics, we follow strictly the hypothesis of probability conservation by extending the Heisenberg picture to unitary evolution with two times. As a result, the observability of two temporal axes is constrained by a generalized uncertainty relation involving level spacings, total duration of the effect and Planck's constant.

  2. A "fundamental theorem" of biomedical informatics.

    PubMed

    Friedman, Charles P

    2009-01-01

    This paper proposes, in words and pictures, a "fundamental theorem" to help clarify what informatics is and what it is not. In words, the theorem stipulates that a person working in partnership with an information resource is "better" than that same person unassisted. The theorem is applicable to health care, research, education, and administrative activities. Three corollaries to the theorem illustrate that informatics is more about people than technology; that in order for the theorem to hold, resources must be informative in addition to being correct; and that the theorem can fail to hold for reasons explained by understanding the interaction between the person and the resource.

  3. Role of serotonin in fish reproduction

    PubMed Central

    Prasad, Parvathy; Ogawa, Satoshi; Parhar, Ishwar S.

    2015-01-01

    The neuroendocrine mechanism regulates reproduction through the hypothalamo-pituitary-gonadal (HPG) axis which is evolutionarily conserved in vertebrates. The HPG axis is regulated by a variety of internal as well as external factors. Serotonin, a monoamine neurotransmitter, is involved in a wide range of reproductive functions. In mammals, serotonin regulates sexual behaviors, gonadotropin release and gonadotropin-release hormone (GnRH) secretion. However, the serotonin system in teleost may also play unique role in the control of reproduction as the mechanism of reproductive control in teleosts is not always the same as in the mammalian models. In fish, the serotonin system is also regulated by natural environmental factors as well as chemical substances. In particular, selective serotonin reuptake inhibitors (SSRIs) are commonly detected as pharmaceutical contaminants in the natural environment. Those factors may influence fish reproductive functions via the serotonin system. This review summarizes the functional significance of serotonin in the teleosts reproduction. PMID:26097446

  4. Fundamental Limits to Nonlinear Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Haji Hosseinloo, Ashkan; Turitsyn, Konstantin

    2015-12-01

    Linear and nonlinear vibration energy harvesting has been the focus of considerable research in recent years. However, fundamental limits on the harvestable energy of a harvester subjected to an arbitrary excitation force and different constraints is not yet fully understood. Understanding these limits is not only essential for an assessment of the technology potential, but it also provides a broader perspective on the current harvesting mechanisms and guidance in their improvement. Here, we derive the fundamental limits on the output power of an ideal energy harvester for arbitrary excitation waveforms and build on the current analysis framework for the simple computation of this limit for more sophisticated setups. We show that the optimal harvester maximizes the harvested energy through a mechanical analog of a buy-low-sell-high strategy. We also propose a nonresonant passive latch-assisted harvester to realize this strategy for an effective harvesting. It is shown that the proposed harvester harvests energy more effectively than its linear and bistable counterparts over a wider range of excitation frequencies and amplitudes. The buy-low-sell-high strategy also reveals why the conventional bistable harvester works well at low-frequency excitation.

  5. Microbial Cellulose Utilization: Fundamentals and Biotechnology

    PubMed Central

    Lynd, Lee R.; Weimer, Paul J.; van Zyl, Willem H.; Pretorius, Isak S.

    2002-01-01

    Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial cellulose utilization, kinetics of microbial cellulose utilization, and contrasting features compared to soluble substrate kinetics. A biological perspective on processing cellulosic biomass is presented, including features of pretreated substrates and alternative process configurations. Organism development is considered for “consolidated bioprocessing” (CBP), in which the production of cellulolytic enzymes, hydrolysis of biomass, and fermentation of resulting sugars to desired products occur in one step. Two organism development strategies for CBP are examined: (i) improve product yield and tolerance in microorganisms able to utilize cellulose, or (ii) express a heterologous system for cellulose hydrolysis and utilization in microorganisms that exhibit high product yield and tolerance. A concluding discussion identifies unresolved issues pertaining to microbial cellulose utilization, suggests approaches by which such issues might be resolved, and contrasts a microbially oriented cellulose hydrolysis paradigm to the more conventional enzymatically oriented paradigm in both fundamental and applied contexts. PMID:12209002

  6. Microbial cellulose utilization: fundamentals and biotechnology.

    PubMed

    Lynd, Lee R; Weimer, Paul J; van Zyl, Willem H; Pretorius, Isak S

    2002-09-01

    Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial cellulose utilization, kinetics of microbial cellulose utilization, and contrasting features compared to soluble substrate kinetics. A biological perspective on processing cellulosic biomass is presented, including features of pretreated substrates and alternative process configurations. Organism development is considered for "consolidated bioprocessing" (CBP), in which the production of cellulolytic enzymes, hydrolysis of biomass, and fermentation of resulting sugars to desired products occur in one step. Two organism development strategies for CBP are examined: (i) improve product yield and tolerance in microorganisms able to utilize cellulose, or (ii) express a heterologous system for cellulose hydrolysis and utilization in microorganisms that exhibit high product yield and tolerance. A concluding discussion identifies unresolved issues pertaining to microbial cellulose utilization, suggests approaches by which such issues might be resolved, and contrasts a microbially oriented cellulose hydrolysis paradigm to the more conventional enzymatically oriented paradigm in both fundamental and applied contexts.

  7. Congenital uterine anomalies affecting reproduction.

    PubMed

    Reichman, David E; Laufer, Marc R

    2010-04-01

    The following review seeks to summarise the current data regarding reproductive outcomes associated with congenital uterine anomalies. Such malformations originate from adverse embryologic events ranging from agenesis to lateral and vertical fusion defects. Associated renal anomalies are common both for the symmetric and asymmetric malformations. While fertility is minimally impacted upon by müllerian anomalies in most cases, such malformations have historically been associated with poor obstetric outcomes such as recurrent miscarriage, second trimester loss, preterm delivery, malpresentation and intrauterine foetal demise (IUFD). The following review delineates the existing literature regarding such outcomes and indicates therapies, where applicable, to optimise the care of such patients.

  8. Procreative tourism and reproductive freedom.

    PubMed

    Cohen, Jean

    2006-07-01

    In many societies, the use of assisted reproduction technology has produced a desire to control and regulate this form of treatment. Politicians have taken most decisions. These regulations hold important implications for patients, and there are no two countries with the same regulations. These important differences have led to a traffic of infertile couples across legislative borders to seek a solution to their problem. Would harmonization of laws have positive effects? It seems that it would lead to a minimal common legislation. Procreative tourism is actually a 'safety valve' for many European couples.

  9. Human reproduction: dominion and limits.

    PubMed

    McCormick, Richard A

    1996-12-01

    The general struggle throughout Christian history has been to seek the proper balance between dominion and limits, intervention and nonintervention, givenness, and creativity. This struggle has worked itself out in six areas that touch human life. In this essay, I will revisit the Catholic tradition's treatment of these in terms of dominion and limits to see whether we can discern developmental patterns that might suggest an approach to issues pertaining to the sources of life (reproductive ethics) as we move into the next century.

  10. Reproductive management of captive parrots.

    PubMed

    Millam, J R

    1999-01-01

    Studies of the behavior of Amazon parrots throughout a reproductive trial indicate that activities such as food gathering, which may occupy large fractions of the activity budget of wild parrots, occupy little time in captivity. This may be one factor contributing to the large percentage of time during which Amazon parrots are generally inactive in typical captive conditions. The extent of inactivity in captive Amazons creates an open time niche wherein enrichment devices might play a role in improving their well being. Studies of the reproductive endocrinology and the behavior of parrots suggest that hand rearing may impair adult fertility and nest box use. Hand rearing may also cause adult Cockatiels to lay eggs on cage floors rather than in nest boxes. However, the use of nest boxes with oversized nest entrances can be very effective in alleviating chronic floor laying in Cockatiels. Another egg-laying problem in Cockatiels, unwanted egg laying, can be prevented by the use of long-acting formulations of the superactive GnRH agonist, leuprolide acetate, which presumably [figure: see text] acts in birds, as in mammals, by down-regulating pituitary GnRH receptors. Manipulations to limit the increases in prolactin normally seen during incubation in poultry can significantly increase egg production. As clutch size in Cockatiels may also be limited by rising prolactin levels, such manipulations may be effective in stimulating egg production in parrots. An alternative approach for increasing flock egg production is to place foster eggs in nests of Cockatiel pairs that are slow to lay. This technique stimulates males to increase their nest-oriented behavior and, subsequently, may stimulate egg laying in some females that might not otherwise have laid eggs. The parental phases of reproduction in Amazon parrots are often a time of heightened aggressiveness towards humans, but low levels of serum testosterone in males during that time suggest that this particular

  11. Sensivity of Adult Reproduction and Reproductive Development in Japanese Medaka Exposed to 4-Tert-octylphenol

    EPA Science Inventory

    In response to legislation, the USEPA is developing assessment tools for identifying chemicals likely to cause sublethal effects on reproduction and reproductive development with ultimate adverse impacts on fish populations. While fecundity and fertility data from short-term adul...

  12. Reproductive physiology in Zebu cattle. Unique reproductive aspects that affect their performance.

    PubMed

    Galina, C S; Orihuela, A; Duchateau, A

    1987-11-01

    This article describes the reproductive physiology of Zebu cattle and specific strategies that, when used in concert with an understanding of the physiologic differences between Zebu and other cattle, can improve reproductive performance. PMID:3319088

  13. Biological markers of male reproductive toxicology

    SciTech Connect

    Ewing, L.L.; Mattison, D.R.

    1987-10-01

    Reproduction is a complex, stepwise series of processes that begins with gametogenesis, continues through gamete interaction, implantation, embryonic development, growth, parturition, and postnatal adaptation, and is completed with the development and sexual maturation of the newly formed organism. These reproductive processes do not take place in a chemically pristine environment, but rather in an environment increasingly contaminated with the products and by-products of the chemical age in which we live. Some environmental pollutants are known to be carcinogenic, mutagenic, or toxic to the reproductive system, but most have not been adequately tested for reproductive toxicity. Just as reproduction is complex, biological mechanisms underlying toxicology are similarly complex and involve absorption, distribution, metabolism (toxification and/or detoxification), excretion, and repair. The synthesis of these sciences into the relatively nascent science of reproductive toxicology includes teratology, pharmacology, epidemiology, and occupational and environmental health. Female reproductive function (especially pregnancy outcome) has historically been the focus of attention, but there is increasing interest in the effects of chemical exposure on male reproductive function. Several reports have documented the physiology, biochemistry, and toxicology of male mammalian reproduction, and evaluated susceptibility of the male to the effects of exogenous chemicals.

  14. Effects of cigarette smoking on reproduction.

    PubMed

    Dechanet, C; Anahory, T; Mathieu Daude, J C; Quantin, X; Reyftmann, L; Hamamah, S; Hedon, B; Dechaud, H

    2011-01-01

    BACKGROUND Cigarette smoking is associated with lower fecundity rates, adverse reproductive outcomes and a higher risk of IVF failures. Over the last few decades, prevalence of smoking among women of reproductive age has increased. This review focuses on current knowledge of the potential effects of smoke toxicants on all reproductive stages and the consequences of smoke exposure on reproductive functions. METHODS We conducted a systematic review of the scientific literature on the impact of cigarette smoking and smoke constituents on the different stages of reproductive function, including epidemiological, clinical and experimental studies. We attempted to create hypotheses and find explanations for the deleterious effects of cigarette smoke observed in experimental studies. RESULTS Cigarette smoke contains several thousand components (e.g. nicotine, polycyclic aromatic hydrocarbons and cadmium) with diverse effects. Each stage of reproductive function, folliculogenesis, steroidogenesis, embryo transport, endometrial receptivity, endometrial angiogenesis, uterine blood flow and uterine myometrium is a target for cigarette smoke components. The effects of cigarette smoke are dose-dependent and are influenced by the presence of other toxic substances and hormonal status. Individual sensitivity, dose, time and type of exposure also play a role in the impact of smoke constituents on human fertility. CONCLUSIONS All stages of reproductive functions are targets of cigarette smoke toxicants. Further studies are necessary to better understand the deleterious effects of cigarette smoke compounds on the reproductive system in order to improve health care, help to reduce cigarette smoking and provide a better knowledge of the molecular mechanisms involved in reproductive toxicology.

  15. Global warming and sexual plant reproduction.

    PubMed

    Hedhly, Afif; Hormaza, José I; Herrero, María

    2009-01-01

    The sexual reproductive phase in plants might be particularly vulnerable to the effects of global warming. The direct effect of temperature changes on the reproductive process has been documented previously, and recent data from other physiological processes that are affected by rising temperatures seem to reinforce the susceptibility of the reproductive process to a changing climate. But the reproductive phase also provides the plant with an opportunity to adapt to environmental changes. Understanding phenotypic plasticity and gametophyte selection for prevailing temperatures, along with possible epigenetic changes during this process, could provide new insights into plant evolution under a global-warming scenario.

  16. Progress in evidence based reproductive surgery

    PubMed Central

    Bosteels, J.; Weyers, S.; Siristatidis, C.; Bhattacharya, S.; D’Hooghe, T.

    2011-01-01

    The Consolidated Standards of Reporting Trials (CONSORT) was introduced in 1996 to improve the methodological quality of published reports of randomised controlled trials. By doing a systematic review of randomised controlled trials on reproductive surgery, our group can demonstrate that the overall quality of the published reports of randomised studies on reproductive surgical interventions has improved after CONSORT. Nevertheless, some problems still remain. By discussing the benefits and pitfalls of randomised trials in reproductive surgery, our opinion paper aims to stimulate the reader’s further interest in evidence-based practice in reproductive surgery. PMID:24753872

  17. Crude oil prices: Speculation versus fundamentals

    NASA Astrophysics Data System (ADS)

    Kolodziej, Marek Krzysztof

    Beginning in 2004, the price of crude oil fluctuates rapidly over a wide range. Large and rapid price increases have recessionary consequences and dampen long-term infrastructural investment. I investigate whether price changes are driven by market fundamentals or speculation. With regard to market fundamentals, I revisit econometric evidence for the importance of demand shocks, as proxied by dry maritime cargo rates, on oil prices. When I eliminate transportation costs from both sides of the equation, disaggregate OPEC and non-OPEC production, and allow for more than one cointegrating relation, I find that previous specifications are inconsistent with arguments that demand shocks play an important role. Instead, results confirm the importance of OPEC supply shocks. I investigate two channels by which speculation may affect oil prices; the direct effect of trader behavior and changes in oil from a commodity to a financial asset. With regard to trader behavior, I find evidence that trader positions are required to explain the spread between spot and futures prices of crude oil on the New York Mercantile Exchange. The inclusion of trader positions clarifies the process of equilibrium error correction, such that there is bidirectional causality between prices and trader positions. This creates the possibility of speculative bubbles. With regard to oil as a commodity and/or financial asset, I use a Kalman Filter model to estimate the time-varying partial correlation between returns to investments in equity and oil markets. This correlation changes from negative to positive at the onset of the 2008 financial crisis. The low interest rates used to rescue the economy depress convenience yields, which reduces the benefits of holding oil as a commodity. Instead, oil becomes a financial asset (on net) as the oil market changed from contango to backwardation. Contradicting simple political narratives, my research suggests that both market fundamentals and speculation drive

  18. Epigenetics and assisted reproductive technologies.

    PubMed

    Pinborg, Anja; Loft, Anne; Romundstad, Liv B; Wennerholm, Ulla-Britt; Söderström-Anttila, Viveca; Bergh, Christina; Aittomäki, Kristiina

    2016-01-01

    Epigenetic modification controls gene activity without changes in the DNA sequence. The genome undergoes several phases of epigenetic programming during gametogenesis and early embryo development, coinciding with assisted reproductive technologies (ART) treatments. Imprinting disorders have been associated with ART techniques, but disentangling the influence of the ART procedures per se from the effect of the reproductive disease of the parents is a challenge. Epidemiological human studies have shown altered birthweight profiles in ART compared with spontaneously conceived singletons. Conception with cryopreserved/thawed embryos results in a higher risk of large-for-gestational-age babies, which may be due to epigenetic modification. Further animal studies have shown altered gene expression profiles in offspring conceived by ART related to altered glucose metabolism. It is controversial whether human adolescents conceived by ART have altered lipid and glucose profiles and thereby a higher long-term risk of cardiovascular disease and diabetes. This commentary describes the basic concepts of epigenetics and gives a short overview of the existing literature on the association between imprinting disorders, epigenetic modification and ART.

  19. Atypical centrioles during sexual reproduction

    PubMed Central

    Avidor-Reiss, Tomer; Khire, Atul; Fishman, Emily L.; Jo, Kyoung H.

    2015-01-01

    Centrioles are conserved, self-replicating, microtubule-based, 9-fold symmetric subcellular organelles that are essential for proper cell division and function. Most cells have two centrioles and maintaining this number of centrioles is important for animal development and physiology. However, how animals gain their first two centrioles during reproduction is only partially understood. It is well established that in most animals, the centrioles are contributed to the zygote by the sperm. However, in humans and many animals, the sperm centrioles are modified in their structure and protein composition, or they appear to be missing altogether. In these animals, the origin of the first centrioles is not clear. Here, we review various hypotheses on how centrioles are gained during reproduction and describe specialized functions of the zygotic centrioles. In particular, we discuss a new and atypical centriole found in sperm and zygote, called the proximal centriole-like structure (PCL). We also discuss another type of atypical centriole, the “zombie” centriole, which is degenerated but functional. Together, the presence of centrioles, PCL, and zombie centrioles suggests a universal mechanism of centriole inheritance among animals and new causes of infertility. Since the atypical centrioles of sperm and zygote share similar functions with typical centrioles in somatic cells, they can provide unmatched insight into centriole biology. PMID:25883936

  20. Role of leptin in reproduction.

    PubMed

    Mantzoros, C S

    2000-01-01

    Leptin is a 16-kDa adipocyte-secreted protein the serum levels of which reflect mainly the amount of energy stores but are also influenced by short-term energy imbalance as well as several cytokines and hormones. Leptin, by binding to specific receptors, alters the expression of several hypothalamic neuropeptides that regulate neuroendocrine function as well as energy intake and expenditure. More specifically, accumulating evidence suggests that this hormone may serve to signal to the brain information on the critical amount of fat stores that are necessary for LHRH secretion and activation of the hypothalamic-pituitary-gonadal axis. Rising leptin levels have been associated with initiation of puberty in animals and humans and normal leptin levels are needed for maintenance of menstrual cycles and normal reproductive function. Moreover, circadian and ultradian variations of leptin levels are associated with minute to minute variations of LH and estradiol in normal women. Falling leptin levels in response to starvation result in decreased estradiol levels and amenorrhea in subjects with anorexia nervosa or strenuously exercising athletes. In addition, leptin has a potentially important role during pregnancy and in the physiology of the neonate. Finally, recent evidence suggests that leptin may influence ovarian steroidogenesis directly, but the exact role of intraovarian leptin action in the physiology and pathophysiology of the human reproductive system needs to be further elucidated.

  1. Global warming and reproductive health.

    PubMed

    Potts, Malcolm; Henderson, Courtney E

    2012-10-01

    The largest absolute numbers of maternal deaths occur among the 40-50 million women who deliver annually without a skilled birth attendant. Most of these deaths occur in countries with a total fertility rate of greater than 4. The combination of global warming and rapid population growth in the Sahel and parts of the Middle East poses a serious threat to reproductive health and to food security. Poverty, lack of resources, and rapid population growth make it unlikely that most women in these countries will have access to skilled birth attendants or emergency obstetric care in the foreseeable future. Three strategies can be implemented to improve women's health and reproductive rights in high-fertility, low-resource settings: (1) make family planning accessible and remove non-evidenced-based barriers to contraception; (2) scale up community distribution of misoprostol for prevention of postpartum hemorrhage and, where it is legal, for medical abortion; and (3) eliminate child marriage and invest in girls and young women, thereby reducing early childbearing.

  2. Polyamines on the reproductive landscape.

    PubMed

    Lefèvre, Pavine L C; Palin, Marie-France; Murphy, Bruce D

    2011-10-01

    The polyamines are ubiquitous polycationic compounds. Over the past 40 yr, investigation has shown that some of these, namely spermine, spermidine, and putrescine, are essential to male and female reproductive processes and to embryo/fetal development. Indeed, their absence is characterized by infertility and arrest in embryogenesis. Mammals synthesize polyamines de novo from amino acids or import these compounds from the diet. Information collected recently has shown that polyamines are essential regulators of cell growth and gene expression, and they have been implicated in both mitosis and meiosis. In male reproduction, polyamine expression correlates with stages of spermatogenesis, and polyamines appear to function in promoting sperm motility. There is evidence for polyamine involvement in ovarian follicle development and ovulation in female mammals, and polyamine synthesis is required for steroidogenesis in the ovary. Studies of the embryo indicate a polyamine requirement that can be met from maternal sources before implantation, whereas elimination of polyamine synthesis abrogates embryo development at gastrulation. Polyamines play roles in embryo implantation, in decidualization, and in placental formation and function, and polyamine privation during gestation results in intrauterine growth retardation. Emerging information implicates dietary arginine and dietary polyamines as nutritional regulators of fertility. The mechanisms by which polyamines regulate these multiple and diverse processes are not yet well explored; thus, there is fertile ground for further productive investigation. PMID:21791568

  3. Atypical centrioles during sexual reproduction.

    PubMed

    Avidor-Reiss, Tomer; Khire, Atul; Fishman, Emily L; Jo, Kyoung H

    2015-01-01

    Centrioles are conserved, self-replicating, microtubule-based, 9-fold symmetric subcellular organelles that are essential for proper cell division and function. Most cells have two centrioles and maintaining this number of centrioles is important for animal development and physiology. However, how animals gain their first two centrioles during reproduction is only partially understood. It is well established that in most animals, the centrioles are contributed to the zygote by the sperm. However, in humans and many animals, the sperm centrioles are modified in their structure and protein composition, or they appear to be missing altogether. In these animals, the origin of the first centrioles is not clear. Here, we review various hypotheses on how centrioles are gained during reproduction and describe specialized functions of the zygotic centrioles. In particular, we discuss a new and atypical centriole found in sperm and zygote, called the proximal centriole-like structure (PCL). We also discuss another type of atypical centriole, the "zombie" centriole, which is degenerated but functional. Together, the presence of centrioles, PCL, and zombie centrioles suggests a universal mechanism of centriole inheritance among animals and new causes of infertility. Since the atypical centrioles of sperm and zygote share similar functions with typical centrioles in somatic cells, they can provide unmatched insight into centriole biology.

  4. Reproductive 'surrogacy' and parental licensing.

    PubMed

    Overall, Christine

    2015-06-01

    A serious moral weakness of reproductive 'surrogacy' is that it can be harmful to the children who are created. This article presents a proposal for mitigating this weakness. Currently, the practice of commercial 'surrogacy' operates only in the interests of the adults involved (the gestator and the commissioning individuals who employ her), not in the interests of the child who is created. Whether 'surrogacy' is seen as the purchase of a baby, the purchase of parental rights, or the purchase of reproductive labor, all three views share the same significant flaws. They endorse the transfer, for a fee, of the infant from the woman who gestated it to those who commissioned it, but without justifying such a transfer; they fail to demonstrate that the commissioners have any entitlement to the infant, or, for that matter, suitability to be the infant's parents; and they fail to take any notice of the infant's needs, interests, and wellbeing. A mere genetic connection is not enough to establish that the commissioners are entitled to receive the baby or that they are competent to raise it. Their good intentions, however caring, are not enough. Therefore, just as in the practice of adoption, there should be a formal institutionalized system for screening and licensing the prospective social parents, which would make the infant's needs, interests, and wellbeing paramount. I reply to several potential objections to this proposal, including the objection that genetic parents who raise their own child are not screened and licensed.

  5. Female Reproductive System and Bone

    PubMed Central

    Clarke, Bart L.; Khosla, Sundeep

    2010-01-01

    The female reproductive system plays a major role in regulating the acquisition and loss of bone by the skeleton from menarche through senescence. Onset of gonadal sex steroid secretion at puberty is the major factor responsible for skeletal longitudinal and radial growth, as well as significant gain in bone density, until peak bone density is achieved in third decade of life. Gonadal sex steroids then help maintain peak bone density until menopause, including during the transient changes in skeletal mineral content associated with pregnancy and lactation. At menopause, decreased gonadal sex steroid production normally leads to rapid bone loss. The most rapid bone loss associated with decreased estrogen levels occurs in the first 8–10 years after menopause, with slower age-related bone loss occurring during later life. Age-related bone loss in women after the early menopausal phase of bone loss is caused by ongoing gonadal sex steroid deficiency, vitamin D deficiency, and secondary hyperparathyroidism. Other factors also contribute to age-related bone loss, including intrinsic defects in osteoblast function, impairment of the GH/IGF axis, reduced peak bone mass, age-associated sarcopenia, and various sporadic secondary causes. Further understanding of the relative contributions of the female reproductive system and each of the other factors to development and maintenance of the female skeleton, bone loss, and fracture risk will lead to improved approaches for prevention and treatment of osteoporosis. PMID:20637179

  6. Atypical centrioles during sexual reproduction.

    PubMed

    Avidor-Reiss, Tomer; Khire, Atul; Fishman, Emily L; Jo, Kyoung H

    2015-01-01

    Centrioles are conserved, self-replicating, microtubule-based, 9-fold symmetric subcellular organelles that are essential for proper cell division and function. Most cells have two centrioles and maintaining this number of centrioles is important for animal development and physiology. However, how animals gain their first two centrioles during reproduction is only partially understood. It is well established that in most animals, the centrioles are contributed to the zygote by the sperm. However, in humans and many animals, the sperm centrioles are modified in their structure and protein composition, or they appear to be missing altogether. In these animals, the origin of the first centrioles is not clear. Here, we review various hypotheses on how centrioles are gained during reproduction and describe specialized functions of the zygotic centrioles. In particular, we discuss a new and atypical centriole found in sperm and zygote, called the proximal centriole-like structure (PCL). We also discuss another type of atypical centriole, the "zombie" centriole, which is degenerated but functional. Together, the presence of centrioles, PCL, and zombie centrioles suggests a universal mechanism of centriole inheritance among animals and new causes of infertility. Since the atypical centrioles of sperm and zygote share similar functions with typical centrioles in somatic cells, they can provide unmatched insight into centriole biology. PMID:25883936

  7. Reproductive 'surrogacy' and parental licensing.

    PubMed

    Overall, Christine

    2015-06-01

    A serious moral weakness of reproductive 'surrogacy' is that it can be harmful to the children who are created. This article presents a proposal for mitigating this weakness. Currently, the practice of commercial 'surrogacy' operates only in the interests of the adults involved (the gestator and the commissioning individuals who employ her), not in the interests of the child who is created. Whether 'surrogacy' is seen as the purchase of a baby, the purchase of parental rights, or the purchase of reproductive labor, all three views share the same significant flaws. They endorse the transfer, for a fee, of the infant from the woman who gestated it to those who commissioned it, but without justifying such a transfer; they fail to demonstrate that the commissioners have any entitlement to the infant, or, for that matter, suitability to be the infant's parents; and they fail to take any notice of the infant's needs, interests, and wellbeing. A mere genetic connection is not enough to establish that the commissioners are entitled to receive the baby or that they are competent to raise it. Their good intentions, however caring, are not enough. Therefore, just as in the practice of adoption, there should be a formal institutionalized system for screening and licensing the prospective social parents, which would make the infant's needs, interests, and wellbeing paramount. I reply to several potential objections to this proposal, including the objection that genetic parents who raise their own child are not screened and licensed. PMID:25082172

  8. Loudness predicts prominence: Fundamental frequency lends little

    NASA Astrophysics Data System (ADS)

    Kochanski, G.; Grabe, E.; Coleman, J.; Rosner, B.

    2005-08-01

    We explored a database covering seven dialects of British and Irish English and three different styles of speech to find acoustic correlates of prominence. We built classifiers, trained the classifiers on human prominence/nonprominence judgments, and then evaluated how well they behaved. The classifiers operate on 452 ms windows centered on syllables, using different acoustic measures. By comparing the performance of classifiers based on different measures, we can learn how prominence is expressed in speech. Contrary to textbooks and common assumption, fundamental frequency (f0) played a minor role in distinguishing prominent syllables from the rest of the utterance. Instead, speakers primarily marked prominence with patterns of loudness and duration. Two other acoustic measures that we examined also played a minor role, comparable to f0. All dialects and speaking styles studied here share a common definition of prominence. The result is robust to differences in labeling practice and the dialect of the labeler.

  9. Fundamental Considerations Of Gas Core Reactor Systems

    NASA Astrophysics Data System (ADS)

    Bussard, Robert W.

    1988-04-01

    Fundamental physics and engineering limitations on gas core reactors (GCR) have been found from coupled effects of reactor neutronics with oscillatory core fuel gas flows and with overall gas dynamics. These show allowable regimes for system operation as natural re-sults of the basiciphysics of the system. Cylindrical BeO-moderated systems, such as the acoustic GCR (AGCR ), are found to be well-suited for pressure wave oscillation at 100-Hz frequencies. These result in stable oscillations of core gas electrical conductivity which may be used for direct alternating current electric power production in magnetohydrodynamic (MHD) convertors. In contrast, single-cavity axial-flow spherical GCR (SGCR2) systems are inherently limited by core flow and fission energy-generation fluctuation phenomena (to continuous wave operation with mixed flows that cannot sustain high internal core gas tempera-ture gradients. Resulting low mixed-mean temperatures place upper limits on system MHD electrical performance.

  10. [Fundamental ophthalmology: the role of electrophysiological studies].

    PubMed

    Zueva, M V

    2014-01-01

    Studying of functional aspects of eye disease pathogenesis by electrophysiological methods is widely demanded in fundamental ophthalmology. Introduction of modern methods of functional assessment into experimental and clinical projects significantly broadens knowledge of normal and pathological functioning of the visual system and is the basis for further development of new strategies of pathogenetic treatment, diagnostics and expert evaluation. Some problems of ophthalmology, including those that concern age-related macular degeneration, glaucoma, diabetic retinopathy, and other diseases, are considered in the context of how much electrophysiology contributes to their solution. The role of functional examinations of the retina in studying pathophysiology of neurodegenerative brain diseases, such as Alzheimer's and Parkinson's, is also discussed. PMID:25715550

  11. Fundamental Constants and Tests with Simple Atoms

    NASA Astrophysics Data System (ADS)

    Tan, Joseph

    2015-05-01

    Precise measurements with simple atoms provide stringent tests of physical laws, improving the accuracy of fundamental constants--a set of which will be selected to fully define the proposed New International System of Units. This talk focuses on the atomic constants (namely, the Rydberg constant, the fine-structure constant, and the proton charge radius), discussing the impact of the proton radius obtained from the Lamb-shift measurements in muonic hydrogen. Significant discrepancies persist despite years of careful examination: the slightly smaller proton radius obtained from muonic hydrogen requires the Rydberg constant and the fine-structure constant to have values that disagree significantly with the CODATA recommendations. After giving a general overview, I will discuss our effort to produce one-electron ions in Rydberg states, to enable a different test of theory and measurement of the Rydberg constant.

  12. The fundamental non-critical string

    NASA Astrophysics Data System (ADS)

    Lugo, Adrián R.; Sturla, Mauricio B.

    2006-06-01

    We obtain the (super) gravity solution in arbitrary space-time dimension less than ten, that gives a low energy description of a fundamental string embedded in a non-critical vacuum, product of d-dimensional Minkowski space-time and a cigar-like geometry with scale r0. This solution, one of the few known examples of objects doubly localized, both at the origin of the transverse space as well as at the tip of the cigar, is determined by its charge Q under the Kalb-Ramond gauge field B, and presumably preserves, for even d, 2 d/2 supercharges. Moreover, we show that the solution is reliable at least in a region far away from both origins, as it is the case with the well known branes of critical string theory.

  13. Fundamental physics of infrared detector materials

    NASA Astrophysics Data System (ADS)

    Kinch, Michael A.

    2001-06-01

    The fundamental parameters of IR photon detection are discussed relevant to the meaningful comparison of a wide range of proposed IR detecting materials systems. The thermal generation rate of the IR material is seen to be the key parameter that enables this comparison. The simple materials physics of (1) intrinsic direct bandgap semiconductors, (2) extrinsic semiconductors, (3) quantum well devices, including types I, II, and III superlattices, (4) Si Schottky barriers, are examined with regard to the potential performance of these materials as IR detectors, utilizing the thermal generation rate as a differentiator. The possibility of room temperature photon detection over the whole IR spectral range is discussed, and comparison made with uncooled thermal detection.

  14. Fundamental physics of infrared detector materials

    NASA Astrophysics Data System (ADS)

    Kinch, Michael A.

    2000-06-01

    The fundamental parameters of IR photon detection are discussed relevant to the meaningful comparison of a wide range of proposed IR detecting materials systems. The thermal generation rate of the IR material is seen to be the key parameter that enables this comparison. The simple materials physics of 1) intrinsic direct bandgap semiconductors; 2) extrinsic semiconductors; 3) quantum well devices, including types I, II, and III superlattices; 4) Si Schottky barriers; and 5) high temperature superconductors, will be examined with regard to the potential performance of these materials as IR detectors, utilizing the thermal generation rate as a differentiator. The possibility of room temperature photon detection over the whole IR spectral range is discussed, and comparisons made with uncooled thermal detection.

  15. Future fundamental combustion research for aeropropulsion systems

    NASA Technical Reports Server (NTRS)

    Mularz, E. J.

    1985-01-01

    Physical fluid mechanics, heat transfer, and chemical kinetic processes which occur in the combustion chamber of aeropropulsion systems were investigated. With the component requirements becoming more severe for future engines, the current design methodology needs the new tools to obtain the optimum configuration in a reasonable design and development cycle. Research efforts in the last few years were encouraging but to achieve these benefits research is required into the fundamental aerothermodynamic processes of combustion. It is recommended that research continues in the areas of flame stabilization, combustor aerodynamics, heat transfer, multiphase flow and atomization, turbulent reacting flows, and chemical kinetics. Associated with each of these engineering sciences is the need for research into computational methods to accurately describe and predict these complex physical processes. Research needs in each of these areas are highlighted.

  16. Fundamental Fluidization Research Project. Environmental Assessment

    SciTech Connect

    Not Available

    1994-01-01

    Morgantown Energy Technology Center proposes to conduct fundamental research on fluidization technology by designing, constructing, and operating a 2-foot diameter, 50-foot high, pressurized fluidized-bed unit. The anticipated result of the proposed project would be a better, understanding of fluidization phenomena under pressurized and high velocity conditions. This improved understanding would, provide a sound basis for design and scale-up of pressurized circulating fluidized-bed combustion (PCFBC) processes for fossil energy applications. Based on the analysis in the EA, DOE has determined that the proposed action is not a major, Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement is not required and the Department is issuing this FONSI.

  17. Sperm preservation: Fundamental cryobiology and practical implications

    SciTech Connect

    Watson, P.F. ); Critser, J.K. ); Mazur, P. )

    1992-01-01

    Human spermatozoa were first frozen successfully almost 40 years ago. While developments in packaging and storing have occurred in the intervening period, there is still little known specifically about how spermatozoa are adversely affected by freezing and thawing. This is largely due to the fact that sufficient cells survive the challenge to give a reasonable expectation of fertilization, but the shift to the exclusive use of cryopreserved semen for donor insemination, occasioned by the awareness of the risks particularly of AIDS transmission, has resulted in a renewed critical interest in the process of cryopreservation. This review will cover the more significant contributions over the past few years, and develop an argument for a sustained fundamental approach to sperm cryobiology.

  18. Sperm preservation: Fundamental cryobiology and practical implications

    SciTech Connect

    Watson, P.F.; Critser, J.K.; Mazur, P.

    1992-07-01

    Human spermatozoa were first frozen successfully almost 40 years ago. While developments in packaging and storing have occurred in the intervening period, there is still little known specifically about how spermatozoa are adversely affected by freezing and thawing. This is largely due to the fact that sufficient cells survive the challenge to give a reasonable expectation of fertilization, but the shift to the exclusive use of cryopreserved semen for donor insemination, occasioned by the awareness of the risks particularly of AIDS transmission, has resulted in a renewed critical interest in the process of cryopreservation. This review will cover the more significant contributions over the past few years, and develop an argument for a sustained fundamental approach to sperm cryobiology.

  19. Fundamental aspects of quantum Brownian motion

    SciTech Connect

    Haenggi, Peter; Ingold, Gert-Ludwig

    2005-06-01

    With this work we elaborate on the physics of quantum noise in thermal equilibrium and in stationary nonequilibrium. Starting out from the celebrated quantum fluctuation-dissipation theorem we discuss some important consequences that must hold for open, dissipative quantum systems in thermal equilibrium. The issue of quantum dissipation is exemplified with the fundamental problem of a damped harmonic quantum oscillator. The role of quantum fluctuations is discussed in the context of both, the nonlinear generalized quantum Langevin equation and the path integral approach. We discuss the consequences of the time-reversal symmetry for an open dissipative quantum dynamics and, furthermore, point to a series of subtleties and possible pitfalls. The path integral methodology is applied to the decay of metastable states assisted by quantum Brownian noise.

  20. Two Fundamental Principles of Nature's Interactions

    NASA Astrophysics Data System (ADS)

    Ma, Tian; Wang, Shouhong

    2014-03-01

    In this talk, we present two fundamental principles of nature's interactions, the principle of interaction dynamics (PID) and the principle of representation invariance (PRI). Intuitively, PID takes the variation of the action functional under energy-momentum conservation constraint. PID offers a completely different and natural way of introducing Higgs fields. PRI requires that physical laws be independent of representations of the gauge groups. These two principles give rise to a unified field model for four interactions, which can be naturally decoupled to study individual interactions. With these two principles, we are able to derive 1) a unified theory for dark matter and dark energy, 2) layered strong and weak interaction potentials, and 3) the energy levels of subatomic particles. Supported in part by NSF, ONR and Chinese NSF.

  1. Graphene oxide: from fundamentals to applications

    NASA Astrophysics Data System (ADS)

    Perrozzi, F.; Prezioso, S.; Ottaviano, L.

    2015-01-01

    In this review, we discuss the fundamental characterization of graphene oxide (GO) and its future application perspectives. Morphology is discussed through optical microscopy, fluorescence microscopy, scanning electron microscopy, and atomic force microscopy studies. Chemical, structural, and vibrational properties are discussed through x-ray photoemission spectroscopy and Raman spectroscopy studies. Two easy characterization strategies, based on the correlation between x-ray photoemission spectroscopy and contact angle/optical contrast measurements are reported. Sensing and nano-biotechnology applications are discussed with focus on practical gas sensing and optical sensing, on the one hand, and on the toxicity issue of GO, on the other hand. Synthesis and post-synthesis treatments are also discussed, these latter with emphasis on lithography.

  2. Constraining fundamental physics with future CMB experiments

    SciTech Connect

    Galli, Silvia; Martinelli, Matteo; Melchiorri, Alessandro; Pagano, Luca; Sherwin, Blake D.; Spergel, David N.

    2010-12-15

    The Planck experiment will soon provide a very accurate measurement of cosmic microwave background anisotropies. This will let cosmologists determine most of the cosmological parameters with unprecedented accuracy. Future experiments will improve and complement the Planck data with better angular resolution and better polarization sensitivity. This unexplored region of the CMB power spectrum contains information on many parameters of interest, including neutrino mass, the number of relativistic particles at recombination, the primordial helium abundance, and the injection of additional ionizing photons by dark matter self-annihilation. We review the imprint of each parameter on the CMB and forecast the constraints achievable by future experiments by performing a Monte Carlo analysis on synthetic realizations of simulated data. We find that next generation satellite missions such as CMBPol could provide valuable constraints with a precision close to that expected in current and near future laboratory experiments. Finally, we discuss the implications of this intersection between cosmology and fundamental physics.

  3. k-strings as fundamental strings

    NASA Astrophysics Data System (ADS)

    Giataganas, Dimitrios

    2015-05-01

    It has been noticed that the k-string observables can be expressed in terms of the fundamental string ones. We identify a sufficient condition for a generic gravity dual background which when satisfied the mapping can be done. The condition is naturally related to a preserved quantity under the T-dualities acting on the Dp-brane describing the high representation Wilson loops. We also find the explicit relation between the observables of the heavy k-quark and the single quark states. As an application to our generic study and motivated by the fact that the anisotropic theories satisfy our condition, we compute the width of the k-string in these theories to find that the logarithmic broadening is still present, but the total result is affected by the anisotropy of the space.

  4. Fundamentals of natural computing: an overview

    NASA Astrophysics Data System (ADS)

    de Castro, Leandro Nunes

    2007-03-01

    Natural computing is a terminology introduced to encompass three classes of methods: (1) those that take inspiration from nature for the development of novel problem-solving techniques; (2) those that are based on the use of computers to synthesize natural phenomena; and (3) those that employ natural materials (e.g., molecules) to compute. The main fields of research that compose these three branches are the artificial neural networks, evolutionary algorithms, swarm intelligence, artificial immune systems, fractal geometry, artificial life, DNA computing, and quantum computing, among others. This paper provides an overview of the fundamentals of natural computing, particularly the fields listed above, emphasizing the biological motivation, some design principles, their scope of applications, current research trends and open problems. The presentation is concluded with a discussion about natural computing, and when it should be used.

  5. Fundamentals of tribology at the atomic level

    NASA Technical Reports Server (NTRS)

    Ferrante, John; Pepper, Stephen V.

    1989-01-01

    Tribology, the science and engineering of solid surfaces in moving contact, is a field that encompasses many disciplines: solid state physics, chemistry, materials science, and mechanical engineering. In spite of the practical importance and maturity of the field, the fundamental understanding of basic phenomena has only recently been attacked. An attempt to define some of these problems and indicate some profitable directions for future research is presented. There are three broad classifications: (1) fluid properties (compression, rheology, additives and particulates); (2) material properties of the solids (deformation, defect formation and energy loss mechanisms); and (3) interfacial properties (adhesion, friction chemical reactions, and boundary films). Research in the categories has traditionally been approached by considering macroscopic material properties. Recent activity has shown that some issues can be approached at the atomic level: the atoms in the materials can be manipulated both experimentally and theoretically, and can produce results related to macroscopic phenomena.

  6. Photoacoustic tomography: fundamentals, advances and prospects

    PubMed Central

    Yao, Junjie; Wang, Lihong V.

    2011-01-01

    Optical microscopy has been contributing to the development of life science for more than three centuries. However, due to strong optical scattering in tissue, its in vivo imaging ability has been restricted to studies at superficial depths. Advances in photoacoustic tomography (PAT) now allow multiscale imaging at depths from sub-millimeter to several centimeters, with spatial resolutions from sub-micrometer to sub-millimeter. Because of this high scalability and its unique optical absorption contrast, PAT is capable of performing anatomical, functional, molecular and fluid-dynamic imaging at various system levels, and is playing an increasingly important role in fundamental biological research and clinical practice. This Review discusses recent technical progress in PAT and presents corresponding applications. It ends with a discussion of several prospects and their technical challenges. PMID:22025335

  7. Fundamentals and applications of gas hydrates.

    PubMed

    Koh, Carolyn A; Sloan, E Dendy; Sum, Amadeu K; Wu, David T

    2011-01-01

    Fundamental understanding of gas hydrate formation and decomposition processes is critical in many energy and environmental areas and has special importance in flow assurance for the oil and gas industry. These areas represent the core of gas hydrate applications, which, albeit widely studied, are still developing as growing fields of research. Discovering the molecular pathways and chemical and physical concepts underlying gas hydrate formation potentially can lead us beyond flowline blockage prevention strategies toward advancing new technological solutions for fuel storage and transportation, safely producing a new energy resource from natural deposits of gas hydrates in oceanic and arctic sediments, and potentially facilitating effective desalination of seawater. The state of the art in gas hydrate research is leading us to new understanding of formation and dissociation phenomena that focuses on measurement and modeling of time-dependent properties of gas hydrates on the basis of their well-established thermodynamic properties.

  8. Magnetic skyrmions: from fundamental to applications

    NASA Astrophysics Data System (ADS)

    Finocchio, Giovanni; Büttner, Felix; Tomasello, Riccardo; Carpentieri, Mario; Kläui, Mathias

    2016-10-01

    In this topical review, we will discuss recent advances in the field of skyrmionics (fundamental and applied aspects) mainly focusing on skyrmions that can be realized in thin film structures where an ultrathin ferromagnetic layer (<1 nm) is coupled to materials with large spin-orbit coupling. We review the basic topological nature of the skyrmion spin structure that can entail a stabilization due to the chiral exchange interaction present in many multilayer systems with structural inversion asymmetry. The static spin structures and the dynamics of the skyrmions are also discussed. In particular, we show that skyrmions can be displaced with high reliability and efficiency as needed for the use in devices. We discuss major possible applications, such as memory, microwave oscillators and logic, and combinations of these, making skyrmions very promising candidates for future low power IT devices.

  9. Fundamentals of Digital Engineering: Designing for Reliability

    NASA Technical Reports Server (NTRS)

    Katz, R.; Day, John H. (Technical Monitor)

    2001-01-01

    The concept of designing for reliability will be introduced along with a brief overview of reliability, redundancy and traditional methods of fault tolerance is presented, as applied to current logic devices. The fundamentals of advanced circuit design and analysis techniques will be the primary focus. The introduction will cover the definitions of key device parameters and how analysis is used to prove circuit correctness. Basic design techniques such as synchronous vs asynchronous design, metastable state resolution time/arbiter design, and finite state machine structure/implementation will be reviewed. Advanced topics will be explored such as skew-tolerant circuit design, the use of triple-modular redundancy and circuit hazards, device transients and preventative circuit design, lock-up states in finite state machines generated by logic synthesizers, device transient characteristics, radiation mitigation techniques. worst-case analysis, the use of timing analyzer and simulators, and others. Case studies and lessons learned from spaceflight designs will be given as examples

  10. Fundamentals of ergonomics in theory and practice.

    PubMed

    Wilson, J R

    2000-12-01

    In this paper ergonomics is defined as a discipline in its own right, as the theoretical and fundamental understanding of human behaviour and performance in purposeful interacting socio-technical systems, and the application of that understanding to design of interactions in the context of real settings. This definition is justified in the financial, technicat, legal, organisational, social, political and professional contexts in which ergonomists work. On the basis of the history of ergonomics and contemporary contributions, it is proposed that it is one of the modern sciences, drawing as much from the field as from the laboratory, and including elements of an art and a craft as well. Justification for the new definition is provided by examining the interacting systems which are prevalent in the modern world and which are the domain best understood through the holistic approach of ergonomics. Finally a number of challenges for ergonomics are identified. PMID:11132041

  11. Fundamentals and applications of gas hydrates.

    PubMed

    Koh, Carolyn A; Sloan, E Dendy; Sum, Amadeu K; Wu, David T

    2011-01-01

    Fundamental understanding of gas hydrate formation and decomposition processes is critical in many energy and environmental areas and has special importance in flow assurance for the oil and gas industry. These areas represent the core of gas hydrate applications, which, albeit widely studied, are still developing as growing fields of research. Discovering the molecular pathways and chemical and physical concepts underlying gas hydrate formation potentially can lead us beyond flowline blockage prevention strategies toward advancing new technological solutions for fuel storage and transportation, safely producing a new energy resource from natural deposits of gas hydrates in oceanic and arctic sediments, and potentially facilitating effective desalination of seawater. The state of the art in gas hydrate research is leading us to new understanding of formation and dissociation phenomena that focuses on measurement and modeling of time-dependent properties of gas hydrates on the basis of their well-established thermodynamic properties. PMID:22432618

  12. Fundamentals of bipolar high-frequency surgery.

    PubMed

    Reidenbach, H D

    1993-04-01

    In endoscopic surgery a very precise surgical dissection technique and an efficient hemostasis are of decisive importance. The bipolar technique may be regarded as a method which satisfies both requirements, especially regarding a high safety standard in application. In this context the biophysical and technical fundamentals of this method, which have been known in principle for a long time, are described with regard to the special demands of a newly developed field of modern surgery. After classification of this method into a general and a quasi-bipolar mode, various technological solutions of specific bipolar probes, in a strict and in a generalized sense, are characterized in terms of indication. Experimental results obtained with different bipolar instruments and probes are given. The application of modern microprocessor-controlled high-frequency surgery equipment and, wherever necessary, the integration of additional ancillary technology into the specialized bipolar instruments may result in most useful and efficient tools of a key technology in endoscopic surgery.

  13. Bat reproduction declines when conditions mimic climate change projections for western North America.

    PubMed

    Adams, Rick A

    2010-08-01

    Climate change models predict that much of western North America is becoming significantly warmer and drier, resulting in overall reductions in availability of water for ecosystems. Herein, I demonstrate that significant declines in the reproductive success of female insectivorous bats occur in years when annual environmental conditions mimic the long-term predictions of regional climate change models. Using a data set gathered on bat populations from 1996 through 2008 along the Front Range of Colorado, I compare trends in population numbers and reproductive outcomes of six species of vespertilionid bats with data on mean annual high temperature, precipitation, snow pack, and stream discharge rates. I show that levels of precipitation and flow rates of small streams near maternity colonies is fundamentally tied to successful reproduction in female bats, particularly during the lactation phase. Across years that experienced greater than average mean temperatures with less than average precipitation and stream flow, bat populations responded by slight to profound reductions in reproductive output depending on the severity of drought conditions. In particular, reproductive outputs showed profound declines (32-51%) when discharge rates of the largest stream in the field area dropped below 7 m3/s, indicating a threshold response. Such sensitivity to environmental change portends severe impacts to regional bat populations if current scenarios for climate change in western North America are accurate. In addition, bats act as early-warning indicators of large-scale ecological effects resulting from further regional warming and drying trends currently at play in western North America.

  14. Beyond Cairo: sexual and reproductive rights of young people in the new development agenda.

    PubMed

    Barroso, Carmen

    2014-01-01

    At the 1994 United Nations International Conference on Population and Development (ICPD), women's rights advocates fundamentally shifted the way the global development community views poverty, gender equality and reproductive rights. While the ICPD's call to action led to a marked improvement in reproductive health, more remains to be done to secure the sexual and reproductive rights and health of all, particularly for young people. As we approach the 20-year anniversary of Cairo, several global processes are happening concurrently that have implications for the future of the sexual and reproductive health and rights agenda, including the 20-year review of progress towards achieving the Cairo Programme of Action, the review of the Millennium Development Goals, and the open group discussions about the sustainable development goals and the new development agenda post-2015. There are five key areas of action where significant investment is needed moving forward to ensure young people's access and safeguard their rights: repeal outdated laws and create new policies that safeguard young people's health and rights; provide youth-friendly sexual and reproductive health services; guarantee young people's access to information and education; end gender discrimination and ensure government accountability.

  15. Negative correlation does not imply a tradeoff between growth and reproduction in California oaks

    PubMed Central

    Knops, Johannes M. H.; Koenig, Walter D.; Carmen, William J.

    2007-01-01

    A tradeoff between growth and reproduction, often inferred from an inverse correlation between these two variables, is a fundamental paradigm of life-history evolution. Oak species provide a unique test of this relationship because different species mature acorns either in the year of pollination or in the year after pollination. This difference allows for an interspecific comparison testing whether the apparent tradeoff is causal or the result of confounding factors influencing growth and reproduction independently. Based on 13 years of data on five California oak species, we found significant negative correlations between radial growth and seed production in the three species that produce acorns the same year in which pollination occurs, but not in two species that mature acorns the year after pollination. Rainfall, which correlates positively with radial growth and correlates negatively with acorn production (based on the year of pollination), appears to be driving this pattern. We conclude that the observed negative correlations are not causal, but rather a consequence of growth and reproduction being dependent, in opposite ways, on environmental conditions. Thus, contrary to the current consensus, growth and reproduction in these species are apparently largely independent of each other. In contrast, tradeoffs between current and future reproduction appear to be much more important in the life-history evolution of these long-lived plants. We also conclude that a negative correlation does not necessarily imply a causal mechanism and should not be used as the only evidence supporting a tradeoff. PMID:17940035

  16. The importance of social science research in protecting adolescents' sexual and reproductive choice.

    PubMed

    Jejeebhoy, S J

    1999-01-01

    This paper reviews the ways in which social science research findings can influence action in the areas of reproductive health and rights. Essentially, social science research: (a) establishes the levels and patterns of behaviours, attitudes or perceptions; (b) explores factors underlying these behaviours, attitudes and perceptions; (c) explains programme and organisational impediments constraining, in practice, the exercise of informed choices or the acquisition of preventive and curative services; (d) monitors the extent to which interventions have been successful in modifying behaviours, attitudes or perceptions, and (e) facilitates an understanding of the policy, social and legal arenas that impinge on the determinants and consequences of reproductive choice. Findings highlight possible courses for legal, policy or programmatic interventions. Such research has enormous relevance for our understanding of reproductive and sexual health, and the health-seeking choices that women and men--from adolescent to adult--make in various settings, the constraints they face in making these choices, and the kinds of interventions that might enhance choices given the prevailing sociocultural context. Focusing on adolescent sexual and reproductive health and choice, the paper concludes that social science research findings are fundamental for informing efforts to protect reproductive rights. PMID:10536390

  17. Fundamental Space Biology 2010-2020

    NASA Astrophysics Data System (ADS)

    Tomko, David; Souza, Kenneth; Quincy, Charles; Sun, Sidney

    The goal of NASA's Fundamental Space Biology (FSB) is to strive for U.S. excellence in the whole range of Space Biology -Cell and Molecular, Microbiology, Plant and Animal Biology, Developmental Biology. NASA plans to solicit and conduct research that will contribute to our basic knowledge of the effect of space on living systems. NASA will issue recurring FSB NASA Research Announcements (NRAs) to more fully engage the space biology community. In doing so, FSB research will optimize ISS utilization, develop and demonstrate technology and hard-ware that will enable new science, and contribute to the base of knowledge that will facilitate human countermeasure development. New research capabilities for whole animal and plant bi-ology will be added, and will be optimized by providing state-of-the-art automated technology and analytic techniques wherever possible to maximize scientific return and optimize animal use. Ground-based research to develop and test hypotheses for flight experiments, including hy-pergravity and hypogravity simulations will be an integral FSB activity. Flight experiments will use the most appropriate platform to achieve science results -e.g., ISS, free flyers, sub-orbital flights, and NASA will work with its international partners and other U.S. agencies to achieve these objectives. FSB's highest priority for the near future is the development of mammalian fundamental research capabilities. Another high priority is the development of hardware for studying multiple generations of large plants. Current research in cell and molecular biology will be expanded to include new analytical capabilities. By taking these steps, NASA hopes to energize the Space Biology user community and advance our knowledge of the effect of gravity on living systems.

  18. Gender and social reproduction: historical perspectives.

    PubMed

    Laslett, B; Brenner, J

    1989-01-01

    It is argued that gender relations and social reproduction were both shaped by macrohistorical processes and shaped the processes. Social reproduction is defined within feminist theory as more than production in the Marxist sense. Societal reproduction is a combination of the organization of production, the organization of social reproduction, the perpetuation of gender, and the continuation of class relations. Social reproduction includes the care and socialization of children and care of the elderly or infirm. Social reproduction includes the organization of sexuality, biological reproduction, and how food, clothing, and shelter are made available. Most social reproduction occurs within the family unit. It is pointed out that variations in the distribution of the work of social reproduction are affected by the family, market, community, and state. The ways in which women construct their own worlds of activity is a central concern. The feminist concept of social reproduction differs from modernization theory, which is concerned with the institutional location of the tasks of social reproduction and the structural effects on the family and gender relations. This literature review focuses only on the history of family strategies and separate gender-related activities. The authors describe the changes in family organization that define men as income producers and women as caretakers, who base child rearing on love and feminine virtue rather than patriarchal authority and religious doctrine. The discussion focuses on the differences in marital relationships, motherhood, and sexuality between upper and middle class and working class women in the 19th century. Among working class women, a good wife was an efficient manager, a skilled domestic worker, and an income earner. The turn of the century was a period of social change marked by smaller average family size, the decline of household production, the rise in real wages, and increased consumption. It is argued that

  19. Widespread presence of human BOULE homologs among animals and conservation of their ancient reproductive function.

    PubMed

    Shah, Chirag; Vangompel, Michael J W; Naeem, Villian; Chen, Yanmei; Lee, Terrance; Angeloni, Nicholas; Wang, Yin; Xu, Eugene Yujun

    2010-07-15

    Sex-specific traits that lead to the production of dimorphic gametes, sperm in males and eggs in females, are fundamental for sexual reproduction and accordingly widespread among animals. Yet the sex-biased genes that underlie these sex-specific traits are under strong selective pressure, and as a result of adaptive evolution they often become divergent. Indeed out of hundreds of male or female fertility genes identified in diverse organisms, only a very small number of them are implicated specifically in reproduction in more than one lineage. Few genes have exhibited a sex-biased, reproductive-specific requirement beyond a given phylum, raising the question of whether any sex-specific gametogenesis factors could be conserved and whether gametogenesis might have evolved multiple times. Here we describe a metazoan origin of a conserved human reproductive protein, BOULE, and its prevalence from primitive basal metazoans to chordates. We found that BOULE homologs are present in the genomes of representative species of each of the major lineages of metazoans and exhibit reproductive-specific expression in all species examined, with a preponderance of male-biased expression. Examination of Boule evolution within insect and mammalian lineages revealed little evidence for accelerated evolution, unlike most reproductive genes. Instead, purifying selection was the major force behind Boule evolution. Furthermore, loss of function of mammalian Boule resulted in male-specific infertility and a global arrest of sperm development remarkably similar to the phenotype in an insect boule mutation. This work demonstrates the conservation of a reproductive protein throughout eumetazoa, its predominant testis-biased expression in diverse bilaterian species, and conservation of a male gametogenic requirement in mice. This shows an ancient gametogenesis requirement for Boule among Bilateria and supports a model of a common origin of spermatogenesis.

  20. Survivability Is More Fundamental Than Evolvability

    PubMed Central

    Palmer, Michael E.; Feldman, Marcus W.

    2012-01-01

    For a lineage to survive over long time periods, it must sometimes change. This has given rise to the term evolvability, meaning the tendency to produce adaptive variation. One lineage may be superior to another in terms of its current standing variation, or it may tend to produce more adaptive variation. However, evolutionary outcomes depend on more than standing variation and produced adaptive variation: deleterious variation also matters. Evolvability, as most commonly interpreted, is not predictive of evolutionary outcomes. Here, we define a predictive measure of the evolutionary success of a lineage that we call the k-survivability, defined as the probability that the lineage avoids extinction for k generations. We estimate the k-survivability using multiple experimental replicates. Because we measure evolutionary outcomes, the initial standing variation, the full spectrum of generated variation, and the heritability of that variation are all incorporated. Survivability also accounts for the decreased joint likelihood of extinction of sub-lineages when they 1) disperse in space, or 2) diversify in lifestyle. We illustrate measurement of survivability with in silico models, and suggest that it may also be measured in vivo using multiple longitudinal replicates. The k-survivability is a metric that enables the quantitative study of, for example, the evolution of 1) mutation rates, 2) dispersal mechanisms, 3) the genotype-phenotype map, and 4) sexual reproduction, in temporally and spatially fluctuating environments. Although these disparate phenomena evolve by well-understood microevolutionary rules, they are also subject to the macroevolutionary constraint of long-term survivability. PMID:22723844

  1. Stress and the reproductive axis.

    PubMed

    Toufexis, D; Rivarola, M A; Lara, H; Viau, V

    2014-09-01

    There exists a reciprocal relationship between the hypothalamic-pituitary-adrenal (HPA) and the hypothalamic-pituitary-gonadal (HPG) axes, wherein the activation of one affects the function of the other and vice versa. For example, both testosterone and oestrogen modulate the response of the HPA axis, whereas activation of the stress axis, especially activation that is repeating or chronic, has an inhibitory effect upon oestrogen and testosterone secretion. Alterations in maternal care can produce significant effects on both HPG and HPA physiology, as well as behaviour in the offspring at adulthood. For example, changes in reproductive behaviour induced by altered maternal care may alter the expression of sex hormone receptors such as oestrogen receptor (ER)α that govern sexual behaviour, and may be particularly important in determining the sexual strategies utilised by females. Stress in adulthood continues to mediate HPG activity in females through activation of a sympathetic neural pathway originating in the hypothalamus and releasing norepinephrine into the ovary, which produces a noncyclic anovulatory ovary that develops cysts. In the opposite direction, sex differences and sex steroid hormones regulate the HPA axis. For example, although serotonin (5-HT) has a stimulatory effect on the HPA axis in humans and rodents that is mediated by the 5-HT1A receptor, only male rodents respond to 5-HT1A antagonism to show increased corticosterone responses to stress. Furthermore, oestrogen appears to decrease 5-HT1A receptor function at presynaptic sites, yet increases 5-HT1A receptor expression at postsynaptic sites. These mechanisms could explain the heightened stress HPA axis responses in females compared to males. Studies on female rhesus macaques show that chronic stress in socially subordinate female monkeys produces a distinct behavioural phenotype that is largely unaffected by oestrogen, a hyporesponsive HPA axis that is hypersensitive to the modulating effects

  2. Stress and the Reproductive Axis

    PubMed Central

    Toufexis, Donna; Rivarola, Maria Angelica; Lara, Hernan; Viau, Victor

    2014-01-01

    There exists a reciprocal relationship between the hypothalamic-pituitary-adrenal (HPA) and the hypothalamic-pituitary-gonadal (HPG) axes wherein the activation of one affects the function of the other and vice versa. For instance, both testosterone and oestrogen modulate the response of the HPA axis, while activation of the stress axis, especially activation that is repeating or chronic, has an inhibitory effect upon oestrogen and testosterone secretion. Alterations in maternal care can produce significant effects on both HPG and HPA physiology and behaviour in the offspring at adulthood. For example, changes in reproductive behaviour induced by altered maternal care may alter the expression of sex hormone receptors like ERα that govern sexual behaviour, and may be particularly important in determining the sexual strategies utilized by females. Stress in adulthood continues to mediate HPG activity in females through activation of a sympathetic neural pathway originating in the hypothalamus and releasing norepinephrine (NE) into the ovary, which produces a non-cyclic anovulatory ovary that develops cysts. In the opposite direction, sex differences and sex steroid hormones regulate the HPA axis. For example, although serotonin (5-HT) has a stimulatory effect on the HPA axis in humans and rodents that is mediated by the 5-HT1A receptor, only male rodents respond to 5-HT1A antagonism to show increased corticosterone responses to stress. Furthermore, oestrogen appears to decrease 5-HT1A receptor function at presynaptic sites, yet increase 5-HT1A receptor expression at postsynaptic sites. These mechanisms could explain heightened stress HPA axis responses in females compared to males. Studies on female rhesus macaques show that chronic stress in socially subordinate female monkeys produces a distinct behavioral phenotype that is largely unaffected by oestrogen, a hypo-responsive HPA axis that is hypersensitive to the modulating effects of oestrogen, and changes in 5-HT

  3. Sexual Plant Reproduction. Agricultural Lesson Plans.

    ERIC Educational Resources Information Center

    Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

    These lesson plans are intended for use in conducting classes on sexual plant reproduction. Presented first are an attention step/problem statement and a series of questions and answers designed to convey general information about sexual plant reproduction/propagation. The following topics are among those discussed: sexual and asexual plant…

  4. [Mechanisms of electromagnetic radiation damaging male reproduction].

    PubMed

    Xue, Lei; Chen, Hao-Yu; Wang, Shui-Ming

    2012-08-01

    More and more evidence from over 50 years of researches on the effects of electromagnetic radiation on male reproduction show that a certain dose of electromagnetic radiation obviously damages male reproduction, particularly the structure and function of spermatogenic cells. The mechanisms of the injury may be associated with energy dysmetabolism, lipid peroxidation, abnormal expressions of apoptosis-related genes and proteins, and DNA damage.

  5. Immune Cells in the Female Reproductive Tract

    PubMed Central

    Kim, Chul Jung; Kim, Dong-Jae; Kang, Jee-hyun

    2015-01-01

    The female reproductive tract has two main functions: protection against microbial challenge and maintenance of pregnancy to term. The upper reproductive tract comprises the fallopian tubes and the uterus, including the endocervix, and the lower tract consists of the ectocervix and the vagina. Immune cells residing in the reproductive tract play contradictory roles: they maintain immunity against vaginal pathogens in the lower tract and establish immune tolerance for sperm and an embryo/fetus in the upper tract. The immune system is significantly influenced by sex steroid hormones, although leukocytes in the reproductive tract lack receptors for estrogen and progesterone. The leukocytes in the reproductive tract are distributed in either an aggregated or a dispersed form in the epithelial layer, lamina propria, and stroma. Even though immune cells are differentially distributed in each organ of the reproductive tract, the predominant immune cells are T cells, macrophages/dendritic cells, natural killer (NK) cells, neutrophils, and mast cells. B cells are rare in the female reproductive tract. NK cells in the endometrium significantly expand in the late secretory phase and further increase their number during early pregnancy. It is evident that NK cells and regulatory T (Treg) cells are extremely important in decidual angiogenesis, trophoblast migration, and immune tolerance during pregnancy. Dysregulation of endometrial/decidual immune cells is strongly related to infertility, miscarriage, and other obstetric complications. Understanding the immune system of the female reproductive tract will significantly contribute to women's health and to success in pregnancy. PMID:25713505

  6. 10 CFR 1017.25 - Reproduction.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Reproduction. 1017.25 Section 1017.25 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) IDENTIFICATION AND PROTECTION OF UNCLASSIFIED CONTROLLED NUCLEAR INFORMATION Physical Protection Requirements § 1017.25 Reproduction. A document marked as containing UCNI may...

  7. 32 CFR 310.20 - Reproduction fees.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... portions of the fee schedule in 32 CFR part 286. ... 32 National Defense 2 2014-07-01 2014-07-01 false Reproduction fees. 310.20 Section 310.20... PROGRAM DOD PRIVACY PROGRAM Access by Individuals § 310.20 Reproduction fees. (a) Assessing fees....

  8. 10 CFR 1017.25 - Reproduction.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Reproduction. 1017.25 Section 1017.25 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) IDENTIFICATION AND PROTECTION OF UNCLASSIFIED CONTROLLED NUCLEAR INFORMATION Physical Protection Requirements § 1017.25 Reproduction. A document marked as containing UCNI may...

  9. 32 CFR 310.20 - Reproduction fees.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... portions of the fee schedule in 32 CFR part 286. ... 32 National Defense 2 2010-07-01 2010-07-01 false Reproduction fees. 310.20 Section 310.20... PROGRAM DOD PRIVACY PROGRAM Access by Individuals § 310.20 Reproduction fees. (a) Assessing fees....

  10. 32 CFR 310.20 - Reproduction fees.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... portions of the fee schedule in 32 CFR part 286. ... 32 National Defense 2 2013-07-01 2013-07-01 false Reproduction fees. 310.20 Section 310.20... PROGRAM DOD PRIVACY PROGRAM Access by Individuals § 310.20 Reproduction fees. (a) Assessing fees....

  11. 10 CFR 1017.25 - Reproduction.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Reproduction. 1017.25 Section 1017.25 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) IDENTIFICATION AND PROTECTION OF UNCLASSIFIED CONTROLLED NUCLEAR INFORMATION Physical Protection Requirements § 1017.25 Reproduction. A document marked as containing UCNI may...

  12. 32 CFR 310.20 - Reproduction fees.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... portions of the fee schedule in 32 CFR part 286. ... 32 National Defense 2 2012-07-01 2012-07-01 false Reproduction fees. 310.20 Section 310.20... PROGRAM DOD PRIVACY PROGRAM Access by Individuals § 310.20 Reproduction fees. (a) Assessing fees....

  13. 10 CFR 1017.25 - Reproduction.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Reproduction. 1017.25 Section 1017.25 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) IDENTIFICATION AND PROTECTION OF UNCLASSIFIED CONTROLLED NUCLEAR INFORMATION Physical Protection Requirements § 1017.25 Reproduction. A document marked as containing UCNI may...

  14. 32 CFR 310.20 - Reproduction fees.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... portions of the fee schedule in 32 CFR part 286. ... 32 National Defense 2 2011-07-01 2011-07-01 false Reproduction fees. 310.20 Section 310.20... PROGRAM DOD PRIVACY PROGRAM Access by Individuals § 310.20 Reproduction fees. (a) Assessing fees....

  15. 10 CFR 1017.25 - Reproduction.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Reproduction. 1017.25 Section 1017.25 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) IDENTIFICATION AND PROTECTION OF UNCLASSIFIED CONTROLLED NUCLEAR INFORMATION Physical Protection Requirements § 1017.25 Reproduction. A document marked as containing UCNI may...

  16. Photosynthesis in reproductive structures: costs and benefits.

    PubMed

    Raven, John A; Griffiths, Howard

    2015-04-01

    The role of photosynthesis by reproductive structures during grain-filling has important implications for cereal breeding, but the methods for assessing the contribution by reproductive structures to grain-filling are invasive and prone to compensatory changes elsewhere in the plant. A technique analysing the natural abundance of stable carbon isotopes in soluble carbohydrates has significant promise. However, it depends crucially on there being no more than two sources of organic carbon (leaf and ear/awn), with significantly different (13)C:(12)C ratios and no secondary fractionation during grain-filling. The role of additional peduncle carbohydrate reserves represents a potential means for N remobilization, as well as for hydraulic continuity during grain-filling. The natural abundance of the stable isotopes of carbon and oxygen are also useful for exploring the influence of reproduction on whole plant carbon and water relations and have been used to examine the resource costs of reproduction in females and males of dioecious plants. Photosynthesis in reproductive structures is widespread among oxygenic photosynthetic organisms, including many clades of algae and embryophytes of different levels of complexity. The possible evolutionary benefits of photosynthesis in reproductive structures include decreasing the carbon cost of reproduction and 'use' of transpiratory loss of water to deliver phloem-immobile calcium Ca(2+) and silicon [Si(OH)4] via the xylem. The possible costs of photosynthesis in reproductive structures are increasing damage to DNA from photosynthetically active, and hence UV-B, radiation and the production of reactive oxygen species.

  17. A DATABASE FOR TRACKING REPRODUCTIVE TOXICOGENOMIC DATA

    EPA Science Inventory

    A Database for Tracking Reproductive Toxicogenomic Data
    Wenjun Bao, Judy Schmid, Amber Goetz, Hongzu Ren and David Dix
    Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Pr...

  18. NEUROENDOCRINE AND REPRODUCTIVE EFFECTS OF PESTICIDES

    EPA Science Inventory

    Neuroendocrine and Reproductive Effects of Pesticides

    1Stoker, TE, Goldman 2, JM and Cooper 2, RL.

    1Gamete and Early Embryogenesis Biology Branch and 2 Endocrinology Branch, Reproductive Toxicology Division, National Health and Environmental Effects Research Laborat...

  19. Astronomers Gain Clues About Fundamental Physics

    NASA Astrophysics Data System (ADS)

    2005-12-01

    An international team of astronomers has looked at something very big -- a distant galaxy -- to study the behavior of things very small -- atoms and molecules -- to gain vital clues about the fundamental nature of our entire Universe. The team used the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT) to test whether the laws of nature have changed over vast spans of cosmic time. The Green Bank Telescope The Robert C. Byrd Green Bank Telescope CREDIT: NRAO/AUI/NSF (Click on image for GBT gallery) "The fundamental constants of physics are expected to remain fixed across space and time; that's why they're called constants! Now, however, new theoretical models for the basic structure of matter indicate that they may change. We're testing these predictions." said Nissim Kanekar, an astronomer at the National Radio Astronomy Observatory (NRAO), in Socorro, New Mexico. So far, the scientists' measurements show no change in the constants. "We've put the most stringent limits yet on some changes in these constants, but that's not the end of the story," said Christopher Carilli, another NRAO astronomer. "This is the exciting frontier where astronomy meets particle physics," Carilli explained. The research can help answer fundamental questions about whether the basic components of matter are tiny particles or tiny vibrating strings, how many dimensions the Universe has, and the nature of "dark energy." The astronomers were looking for changes in two quantities: the ratio of the masses of the electron and the proton, and a number physicists call the fine structure constant, a combination of the electron charge, the speed of light and the Planck constant. These values, considered fundamental physical constants, once were "taken as time independent, with values given once and forever" said German particle physicist Christof Wetterich. However, Wetterich explained, "the viewpoint of modern particle theory has changed in recent years," with ideas such as

  20. Reproductive experiential regulation of cognitive and emotional resilience.

    PubMed

    Kinsley, Craig H; Bales, Karen L; Bardi, Massimo; Stolzenberg, Danielle S

    2015-11-01

    Adaptation virtually defines survival. For mammals, arguably, no other developmental milestone is exemplified by--nor more reliant on--the sudden and dramatic behavioral alterations observed in the maternal female, which rapidly must undergo change in order to express a large suite of proper and effective maternal behaviors. As pregnancy progresses, as well as during lactation, when pup cues are rich and rampant, the female is literally transformed from an organism that actively avoided offspring-related signals, to one highly motivated by those same cues to build nests, be attracted to pups and to retrieve, group, groom, crouch-over, care for, and protect, the young. Ancillary responses such as reference memory, spatial learning, foraging (including predation), and boldness improve in mothers compared to virgins. Such modifications arise early and are persistent, with neural benefits that last well into senescence. Evolutionarily, such enhancements have likely reduced the maternal burdens associated with sheltering and feeding the vulnerable young; collectively, this strengthens the mother's/parent's reproductive fitness and that of the pups in which all this effort is invested. Of the many behaviors that change as a function of pending or concurrent maternity, therefore, what is the role of modifications to resilience, the ability to withstand the numerous, unpredictable, and threatening environmental events that the mother/parent must daily, indeed, multiply daily, face and thwart in order to bring the offspring from pups to fully functioning adults. We explore these questions, and their connections, here in a multi-disciplinary manner focused on the constellation of change that summates to fundamentally alter the female for the rest of her life. Behavior, brain, neurochemistry and genes are fundamentally changed as the substrate for reproduction unfolds and expresses its inherent plasticity.

  1. Reconstructing the reproductive mode of an Ediacaran macro-organism.

    PubMed

    Mitchell, Emily G; Kenchington, Charlotte G; Liu, Alexander G; Matthews, Jack J; Butterfield, Nicholas J

    2015-08-20

    Enigmatic macrofossils of late Ediacaran age (580-541 million years ago) provide the oldest known record of diverse complex organisms on Earth, lying between the microbially dominated ecosystems of the Proterozoic and the Cambrian emergence of the modern biosphere. Among the oldest and most enigmatic of these macrofossils are the Rangeomorpha, a group characterized by modular, self-similar branching and a sessile benthic habit. Localized occurrences of large in situ fossilized rangeomorph populations allow fundamental aspects of their biology to be resolved using spatial point process techniques. Here we use such techniques to identify recurrent clustering patterns in the rangeomorph Fractofusus, revealing a complex life history of multigenerational, stolon-like asexual reproduction, interspersed with dispersal by waterborne propagules. Ecologically, such a habit would have allowed both for the rapid colonization of a localized area and for transport to new, previously uncolonized areas. The capacity of Fractofusus to derive adult morphology by two distinct reproductive modes documents the sophistication of its underlying developmental biology. PMID:26237408

  2. Plant reproduction in the Central Amazonian floodplains: challenges and adaptations

    PubMed Central

    Ferreira, Cristiane Silva; Piedade, Maria Teresa Fernandez; de Oliveira Wittmann, Astrid; Franco, Augusto César

    2010-01-01

    Background The Central Amazonian floodplain forests are subjected to extended periods of flooding and to flooding amplitudes of 10 m or more. The predictability, the length of the flood pulse, the abrupt transition in the environmental conditions along topographic gradients on the banks of major rivers in Central Amazonia, and the powerful water and sediment dynamics impose a strong selective pressure on plant reproduction systems. Scope In this review, we examine how the hydrological cycle influences the strategies of sexual and asexual reproduction in herbaceous and woody plants. These are of fundamental importance for the completion of the life cycle. Possible constraints to seed germination, seedling establishment and formation of seed banks are also covered. Likewise, we also discuss the importance of river connectivity for species propagation and persistence in floodplains. Conclusions The propagation and establishment strategies employed by the highly diversified assortment of different plant life forms result in contrasting successional stages and a zonation of plant assemblages along the flood-level gradient, whose species composition and successional status are continuously changing not only temporally but also spatially along the river channel. PMID:22476067

  3. Reconstructing the reproductive mode of an Ediacaran macro-organism.

    PubMed

    Mitchell, Emily G; Kenchington, Charlotte G; Liu, Alexander G; Matthews, Jack J; Butterfield, Nicholas J

    2015-08-20

    Enigmatic macrofossils of late Ediacaran age (580-541 million years ago) provide the oldest known record of diverse complex organisms on Earth, lying between the microbially dominated ecosystems of the Proterozoic and the Cambrian emergence of the modern biosphere. Among the oldest and most enigmatic of these macrofossils are the Rangeomorpha, a group characterized by modular, self-similar branching and a sessile benthic habit. Localized occurrences of large in situ fossilized rangeomorph populations allow fundamental aspects of their biology to be resolved using spatial point process techniques. Here we use such techniques to identify recurrent clustering patterns in the rangeomorph Fractofusus, revealing a complex life history of multigenerational, stolon-like asexual reproduction, interspersed with dispersal by waterborne propagules. Ecologically, such a habit would have allowed both for the rapid colonization of a localized area and for transport to new, previously uncolonized areas. The capacity of Fractofusus to derive adult morphology by two distinct reproductive modes documents the sophistication of its underlying developmental biology.

  4. Reproductive science in the global village.

    PubMed

    Chenoweth, P J

    2012-08-01

    Livestock production contributes not only to national economies, but also to sustainability and profitability of agriculture, as well as to the fabric of local societies. Efficient and viable animal production systems are dependent upon the effective management of animal reproduction. Similar arguments can be made in support of the importance of reproduction for companion and performance animals, whereas its key role in preserving endangered species is indisputable. Despite such considerations, the widespread dissemination of current and credible information regarding animal reproduction faces challenges, not only in the developing world, but also in developed countries, where animal reproduction education is apparently in decline. This review will examine these issues, as well as various ways in which animal reproduction education and knowledge transfer is currently being pursued throughout the world. It will conclude with suggested avenues and opportunities for improvement.

  5. Gender, sexual health and reproductive health promotion.

    PubMed

    Moeti, M R

    1995-01-01

    The underlying factors of poverty, migration, marginalization, lack of information and skills, disempowerment, and poor access to services which affect HIV/STD risk are also closely related to those which affect sexual and reproductive health. Reproductive health problems include unplanned and unwanted pregnancies, unsafe abortions, pregnancy-related illness and death, and STDs including HIV/AIDS. This interrelationship between factors is leading increasingly to the integration of HIV/STD education and prevention within the broader framework of sexual and reproductive health promotion. Such intervention allows the possible reinforcement of the impact of interventions upon important underlying factors and behaviors linked to individual, family, and community vulnerability to HIV/STDs as well as other reproductive health problems. Integration will also optimize the use of increasingly scarce resources and increase the likelihood of responses, interventions, and programs being sustainable. Sexual and reproductive health, placing HIV/STD prevention into context, and focus upon men are discussed.

  6. Fundamental Characterization Studies of Advanced Photocatalytic Materials

    NASA Astrophysics Data System (ADS)

    Phivilay, Somphonh Peter

    Solar powered photocatalytic water splitting has been proposed as a method for the production of sustainable, non-carbon hydrogen fuel. Although much technological progress has been achieved in recent years in the discovery of advanced photocatalytic materials, the progress in the fundamental scientific understanding of such novel, complex mixed oxide and oxynitride photocatalysts has significantly lagged. One of the major reasons for this slow scientific progress is the limited number of reported surface characterization studies of the complex bulk mixed oxide and oxynitride photocatalyst systems. Although photocatalytic splitting of water by bulk mixed oxide and oxynitride materials involves both bulk (generation of excited electrons and holes) and surface phenomena (reaction of H2O with excited electrons and holes at the surface), the photocatalysis community has almost completely ignored the surface characteristics of such complex bulk photocatalysts and correlates the photocatalytic properties with bulk properties. Some of the most promising photocatalyst systems (NaTaO3, GaN, (Ga1-xZnx)(N1-xOx) and TaON) were investigated to establish fundamental bulk/surface structure photoactivity relationships. The bulk molecular and electronic structures of the photocatalysts were determined with Raman and UV-vis spectroscopy. Photoluminescence (PL) and transient PL spectroscopy were provided insight into how recombination of photogenerated electrons is related to the photocatalysis activity. The chemical states and atomic compositions of the surface region of the photocatalysts were determined with high resolution X-ray photoelectron spectroscopy (˜1-3 nm) and high sensitivity-low energy ion scattering spectroscopy (˜0.3 nm). The new insights obtained from surface characterization clarified the role of La and Ni promoters species for the NaTaO3 photocatalyst system. The La2O3 additive was found to be a structural promoter that stabilizes small NaTaO3 nanoparticles (NPs

  7. Inherited thrombophilia and reproductive disorders

    PubMed Central

    Liatsikos, Spyros A.; Tsikouras, Panagiotis; Manav, Bachar; Csorba, Roland; von Tempelhoff, Georg Friedrich; Galazios, Georgios

    2016-01-01

    Apart from its established role in the pathogenesis of venous thromboembolism (VTE), inherited thrombophilia has been proposed as a possible cause of pregnancy loss and vascular gestational complications. There is a lot of controversy in the literature on the relationship between inherited prothrombotic defects and these obstetric complications. This is a review of the literature on inherited thrombophilia and reproductive disorders. Factor V Leiden, prothrombin G20210A mutation, and protein S deficiency seem to be associated with late and recurrent early pregnancy loss, while their impact on other pregnancy complications is conflicting. No definite association has been established between protein C and antithrombin deficiency and adverse pregnancy outcome, primarily due to their low prevalence. Screening is suggested only for women with early recurrent loss or late pregnancy loss. Anticoagulant treatment during pregnancy should be considered for women with complications who were tested positive for thrombophilia. PMID:27026779

  8. Crane reproductive physiology and conservation

    USGS Publications Warehouse

    Gee, G.F.

    1983-01-01

    Some unique features of crane reproduction, management, and conservation are described. Because cranes are sexually monomorphic, sexing is difficult and must be accomplished using behavior, laparoscopy, cloacal examination, genetic techniques, or fecal steroid analysis. Although husbandry techniques for cranes are similar to those used with other nondomestic birds, a number of basic characteristics, such as extreme aggressiveness, imprinting by the crane chick on man, a delayed molt in the immature crane, delayed sexual maturity, and infertility, pose special problems for the propagator. Artificial insemination is a practical solution to crane infertility. Vigorous captive management and propagation efforts must become increasingly important if several endangered crane species are to survive the continuing decline in wild populations. The ultimate goal is the restoration of suitable habitat and sustainable native populations.

  9. [Smoking and female reproductive health].

    PubMed

    Sajdak, Stefan; Witczak, Kamila; Sroka, Lukasz; Samulak, Dariusz

    2005-01-01

    Epidemiological data shows that 9 millions of Poles are in smokers group, 43% of them are women. Smoking has significant negative impact on different fields of female sexual and reproductive life, like menstrual cycle, fertility, gynecological cancers and early menopause. Smoking during pregnancy is an important cause of ill health for both mother and foetus-it increases risk of placental complications, pregnancy induced hypertension, reduced fetal growth and perinatal death. Many of adverse effects of smoking is at least partially reversible after stopping smoking, so large public information campaigns can be useful for increasing women awareness of smoking hazards. Gynecologist, as a first contact specialist, has a responsibility to provide accurate information on the risks smoking poses both to the health of the smoker and to give clear, firm advice to stop smoking and offer suitable support.

  10. Ultrasound in assisted reproductive technology.

    PubMed

    Porter, Misty Blanchette

    2008-05-01

    Transvaginal ultrasound-guided oocyte retrieval is the gold standard for in vitro fertilization (IVF) treatment. Despite its relative safety, oocyte retrieval is associated with risk to the adjacent pelvic organs, bleeding, and pelvic infection. The embryo transfer (ET) procedure is considered a crucial step in an IVF cycle. The success of the ET is dependent upon multiple factors including embryo quality, proper endometrial receptivity, and the technique by which the embryos are transferred. Optimizing the technique of ET would therefore provide the best chance for pregnancy. No standard evidence-based protocol exists, but ET with ultrasound guidance has been shown to significantly increase the chance of embryo implantation, an ongoing pregnancy, and a live birth and to improve the ease of transfer. Identifying appropriate ultrasound-guided simulation training techniques in ET would ensure adequate fellowship training without affecting the outcome of assisted reproductive technology cycles. PMID:18504701

  11. Legal developments in assisted reproduction.

    PubMed

    Dickens, Bernard M

    2008-05-01

    Courts have been quite consistent in allowing ex-partners in marriages or similar relationships, usually men, to veto the other partner's reproductive use of jointly-created IVF embryos. This supports the principle of voluntary parenthood. In contrast, child custody disputes following surrogate motherhood may favor the commissioning couple or the surrogate. Decisive are the best interests of the child, which a court may find favorable to the former or the latter, or custody shared between them. Preimplantation genetic diagnosis (PGD) may be restricted by governmental licensing regulations, and raises concerns about diagnosis showing noninheritance of a feared disorder, but not other conditions harming a subsequently born child. Travel abroad raises concerns of legality. Some countries explicitly allow nationals to go to other countries for services legally barred in their own, but others would bind nationals by their prohibitive laws if they were to receive, or counsel, services abroad that are lawful where delivered. PMID:18289543

  12. 21 CFR 884.6150 - Assisted reproduction micromanipulators and microinjectors.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Assisted reproduction micromanipulators and... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6150 Assisted reproduction micromanipulators and microinjectors. (a)...

  13. 21 CFR 884.6140 - Assisted reproduction micropipette fabrication instruments.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Assisted reproduction micropipette fabrication... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6140 Assisted reproduction micropipette fabrication instruments. (a)...

  14. 21 CFR 884.6140 - Assisted reproduction micropipette fabrication instruments.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Assisted reproduction micropipette fabrication... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6140 Assisted reproduction micropipette fabrication instruments. (a)...

  15. 21 CFR 884.6150 - Assisted reproduction micromanipulators and microinjectors.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Assisted reproduction micromanipulators and... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6150 Assisted reproduction micromanipulators and microinjectors. (a)...

  16. 21 CFR 884.6140 - Assisted reproduction micropipette fabrication instruments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction micropipette fabrication... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6140 Assisted reproduction micropipette fabrication instruments. (a)...

  17. 21 CFR 884.6140 - Assisted reproduction micropipette fabrication instruments.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Assisted reproduction micropipette fabrication... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6140 Assisted reproduction micropipette fabrication instruments. (a)...

  18. 21 CFR 884.6150 - Assisted reproduction micromanipulators and microinjectors.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Assisted reproduction micromanipulators and... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6150 Assisted reproduction micromanipulators and microinjectors. (a)...

  19. 21 CFR 884.6150 - Assisted reproduction micromanipulators and microinjectors.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Assisted reproduction micromanipulators and... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6150 Assisted reproduction micromanipulators and microinjectors. (a)...

  20. 21 CFR 884.6140 - Assisted reproduction micropipette fabrication instruments.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Assisted reproduction micropipette fabrication... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6140 Assisted reproduction micropipette fabrication instruments. (a)...