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Sample records for model reproductive number

  1. Reproduction numbers of infectious disease models

    Directory of Open Access Journals (Sweden)

    Pauline van den Driessche

    2017-08-01

    Full Text Available This primer article focuses on the basic reproduction number, ℛ0, for infectious diseases, and other reproduction numbers related to ℛ0 that are useful in guiding control strategies. Beginning with a simple population model, the concept is developed for a threshold value of ℛ0 determining whether or not the disease dies out. The next generation matrix method of calculating ℛ0 in a compartmental model is described and illustrated. To address control strategies, type and target reproduction numbers are defined, as well as sensitivity and elasticity indices. These theoretical ideas are then applied to models that are formulated for West Nile virus in birds (a vector-borne disease, cholera in humans (a disease with two transmission pathways, anthrax in animals (a disease that can be spread by dead carcasses and spores, and Zika in humans (spread by mosquitoes and sexual contacts. Some parameter values from literature data are used to illustrate the results. Finally, references for other ways to calculate ℛ0 are given. These are useful for more complicated models that, for example, take account of variations in environmental fluctuation or stochasticity. Keywords: Basic reproduction number, Disease control, West Nile virus, Cholera, Anthrax, Zika virus

  2. On the Reproduction Number of a Gut Microbiota Model.

    Science.gov (United States)

    Barril, Carles; Calsina, Àngel; Ripoll, Jordi

    2017-11-01

    A spatially structured linear model of the growth of intestinal bacteria is analysed from two generational viewpoints. Firstly, the basic reproduction number associated with the bacterial population, i.e. the expected number of daughter cells per bacterium, is given explicitly in terms of biological parameters. Secondly, an alternative quantity is introduced based on the number of bacteria produced within the intestine by one bacterium originally in the external media. The latter depends on the parameters in a simpler way and provides more biological insight than the standard reproduction number, allowing the design of experimental procedures. Both quantities coincide and are equal to one at the extinction threshold, below which the bacterial population becomes extinct. Optimal values of both reproduction numbers are derived assuming parameter trade-offs.

  3. A model for estimating the minimum number of offspring to sample in studies of reproductive success.

    Science.gov (United States)

    Anderson, Joseph H; Ward, Eric J; Carlson, Stephanie M

    2011-01-01

    Molecular parentage permits studies of selection and evolution in fecund species with cryptic mating systems, such as fish, amphibians, and insects. However, there exists no method for estimating the number of offspring that must be assigned parentage to achieve robust estimates of reproductive success when only a fraction of offspring can be sampled. We constructed a 2-stage model that first estimated the mean (μ) and variance (v) in reproductive success from published studies on salmonid fishes and then sampled offspring from reproductive success distributions simulated from the μ and v estimates. Results provided strong support for modeling salmonid reproductive success via the negative binomial distribution and suggested that few offspring samples are needed to reject the null hypothesis of uniform offspring production. However, the sampled reproductive success distributions deviated significantly (χ(2) goodness-of-fit test p value reproductive success distribution at rates often >0.05 and as high as 0.24, even when hundreds of offspring were assigned parentage. In general, reproductive success patterns were less accurate when offspring were sampled from cohorts with larger numbers of parents and greater variance in reproductive success. Our model can be reparameterized with data from other species and will aid researchers in planning reproductive success studies by providing explicit sampling targets required to accurately assess reproductive success.

  4. Constrained minimization problems for the reproduction number in meta-population models.

    Science.gov (United States)

    Poghotanyan, Gayane; Feng, Zhilan; Glasser, John W; Hill, Andrew N

    2018-02-14

    The basic reproduction number ([Formula: see text]) can be considerably higher in an SIR model with heterogeneous mixing compared to that from a corresponding model with homogeneous mixing. For example, in the case of measles, mumps and rubella in San Diego, CA, Glasser et al. (Lancet Infect Dis 16(5):599-605, 2016. https://doi.org/10.1016/S1473-3099(16)00004-9 ), reported an increase of 70% in [Formula: see text] when heterogeneity was accounted for. Meta-population models with simple heterogeneous mixing functions, e.g., proportionate mixing, have been employed to identify optimal vaccination strategies using an approach based on the gradient of the effective reproduction number ([Formula: see text]), which consists of partial derivatives of [Formula: see text] with respect to the proportions immune [Formula: see text] in sub-groups i (Feng et al. in J Theor Biol 386:177-187, 2015.  https://doi.org/10.1016/j.jtbi.2015.09.006 ; Math Biosci 287:93-104, 2017.  https://doi.org/10.1016/j.mbs.2016.09.013 ). These papers consider cases in which an optimal vaccination strategy exists. However, in general, the optimal solution identified using the gradient may not be feasible for some parameter values (i.e., vaccination coverages outside the unit interval). In this paper, we derive the analytic conditions under which the optimal solution is feasible. Explicit expressions for the optimal solutions in the case of [Formula: see text] sub-populations are obtained, and the bounds for optimal solutions are derived for [Formula: see text] sub-populations. This is done for general mixing functions and examples of proportionate and preferential mixing are presented. Of special significance is the result that for general mixing schemes, both [Formula: see text] and [Formula: see text] are bounded below and above by their corresponding expressions when mixing is proportionate and isolated, respectively.

  5. Spatially explicit models, generalized reproduction numbers and the prediction of patterns of waterborne disease

    Science.gov (United States)

    Rinaldo, A.; Gatto, M.; Mari, L.; Casagrandi, R.; Righetto, L.; Bertuzzo, E.; Rodriguez-Iturbe, I.

    2012-12-01

    still lacking. Here, we show that the requirement that all the local reproduction numbers R0 be larger than unity is neither necessary nor sufficient for outbreaks to occur when local settlements are connected by networks of primary and secondary infection mechanisms. To determine onset conditions, we derive general analytical expressions for a reproduction matrix G0 explicitly accounting for spatial distributions of human settlements and pathogen transmission via hydrological and human mobility networks. At disease onset, a generalized reproduction number Λ0 (the dominant eigenvalue of G0) must be larger than unity. We also show that geographical outbreak patterns in complex environments are linked to the dominant eigenvector and to spectral properties of G0. Tests against data and computations for the 2010 Haiti and 2000 KwaZulu-Natal cholera outbreaks, as well as against computations for metapopulation networks, demonstrate that eigenvectors of G0 provide a synthetic and effective tool for predicting the disease course in space and time. Networked connectivity models, describing the interplay between hydrology, epidemiology and social behavior sustaining human mobility, thus prove to be key tools for emergency management of waterborne infections.

  6. Reproduction numbers for epidemic models with households and other social structures II: Comparisons and implications for vaccination.

    Science.gov (United States)

    Ball, Frank; Pellis, Lorenzo; Trapman, Pieter

    2016-04-01

    In this paper we consider epidemic models of directly transmissible SIR (susceptible → infective → recovered) and SEIR (with an additional latent class) infections in fully-susceptible populations with a social structure, consisting either of households or of households and workplaces. We review most reproduction numbers defined in the literature for these models, including the basic reproduction number R0 introduced in the companion paper of this, for which we provide a simpler, more elegant derivation. Extending previous work, we provide a complete overview of the inequalities among these reproduction numbers and resolve some open questions. Special focus is put on the exponential-growth-associated reproduction number Rr, which is loosely defined as the estimate of R0 based on the observed exponential growth of an emerging epidemic obtained when the social structure is ignored. We show that for the vast majority of the models considered in the literature Rr ≥ R0 when R0 ≥ 1 and Rr ≤ R0 when R0 ≤ 1. We show that, in contrast to models without social structure, vaccination of a fraction 1-1/R0 of the population, chosen uniformly at random, with a perfect vaccine is usually insufficient to prevent large epidemics. In addition, we provide significantly sharper bounds than the existing ones for bracketing the critical vaccination coverage between two analytically tractable quantities, which we illustrate by means of extensive numerical examples. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. THE DISCOUNTED REPRODUCTIVE NUMBER FOR EPIDEMIOLOGY

    OpenAIRE

    Reluga, Timothy C.; Medlock, Jan; Galvani, Alison

    2009-01-01

    The basic reproductive number, , and the effective reproductive number, , are commonly used in mathematical epidemiology as summary statistics for the size and controllability of epidemics. However, these commonly used reproductive numbers can be misleading when applied to predict pathogen evolution because they do not incorporate the impact of the timing of events in the life-history cycle of the pathogen. To study evolution problems where the host population size is changing, measur...

  8. Effects of Vaccine Efficacy on Basic Reproduction Number of a ...

    African Journals Online (AJOL)

    This paper addresses the effect of vaccine efficacy rate on a vaccination model of tuberculosis (TB) epidemic. Numerical simulations was performed on the model using Maple 15 computation software. Our results showed that as the levels of vaccine efficacy increase, the basic reproduction number, R0, decreases.

  9. Estimating reproduction numbers for adults and children from case data

    Science.gov (United States)

    Glass, K.; Mercer, G. N.; Nishiura, H.; McBryde, E. S.; Becker, N. G.

    2011-01-01

    We present a method for estimating reproduction numbers for adults and children from daily onset data, using pandemic influenza A(H1N1) data as a case study. We investigate the impact of different underlying transmission assumptions on our estimates, and identify that asymmetric reproduction matrices are often appropriate. Under-reporting of cases can bias estimates of the reproduction numbers if reporting rates are not equal across the two age groups. However, we demonstrate that the estimate of the higher reproduction number is robust to disproportionate data-thinning. Applying the method to 2009 pandemic influenza H1N1 data from Japan, we demonstrate that the reproduction number for children was considerably higher than that of adults, and that our estimates are insensitive to our choice of reproduction matrix. PMID:21345858

  10. Modelling the effect of temperature change on the extrinsic incubation period and reproductive number of Plasmodium falciparum in Malaysia.

    Science.gov (United States)

    Chua, T H

    2012-03-01

    According to the report of the Intergovernmental Panel on Climate Change (IPCC), Malaysia will experience an increase of 3-5°C in the future. As the development of the malaria parasite, Plasmodium falciparum, is sensitive to temperature, we investigated, using computer models, the effect of increase of 3º and 5ºC on the possible changes in the epidemiology of malaria transmission of P. falciparum in Malaysia. Four environmentally different locations were selected: Kuala Lumpur (KL), Cameron Highlands (CH), Kota Kinabalu (KK) and Kinabalu Park (KP). The extrinsic incubation period (EIP) was estimated using hourly temperatures and the mean daily temperatures. The EIP values estimated using the mean daily temperature were lower than those computed from hourly temperatures in warmer areas (KL, KK), but higher in the cooler areas (CH, KP). The computer simulations also indicated that the EIP will be decreased if the temperature was raised by 3º or 5ºC, with the effect more pronounced for the greater temperature increase, and for the cooler places. The vector cohort that is still alive at a time to transmit malaria (s(EIP)) also increased when the temperature was raised, with the increase more pronounced in the cooler areas. This study indicates an increase in temperature will have more significant effect in shortening the EIP in a cooler place (eg CH, KP), resulting in a greater s(EIP), and consequently increasing the transmission intensity and malaria risk. A temperature increase arising from the global climate change will likely affect the epidemiology of malaria in Malaysia, especially in the cooler areas.

  11. Cholera in Haiti: Reproductive numbers and vaccination coverage estimates

    Science.gov (United States)

    Mukandavire, Zindoga; Smith, David L.; Morris, J. Glenn, Jr.

    2013-01-01

    Cholera reappeared in Haiti in October, 2010 after decades of absence. Cases were first detected in Artibonite region and in the ensuing months the disease spread to every department in the country. The rate of increase in the number of cases at the start of epidemics provides valuable information about the basic reproductive number (). Quantitative analysis of such data gives useful information for planning and evaluating disease control interventions, including vaccination. Using a mathematical model, we fitted data on the cumulative number of reported hospitalized cholera cases in Haiti. varied by department, ranging from 1.06 to 2.63. At a national level, 46% vaccination coverage would result in an () cholera vaccines in endemic and non-endemic regions, our results suggest that moderate cholera vaccine coverage would be an important element of disease control in Haiti.

  12. REPRODUCTIVE NUMBERS, EPIDEMIC SPREAD AND CONTROL IN A COMMUNITY OF HOUSEHOLDS

    OpenAIRE

    Goldstein, E.; Paur, K.; Fraser, C.; Kenah, E.; Wallinga, J.; Lipsitch, M.

    2009-01-01

    Many of the studies on emerging epidemics (such as SARS and pandemic flu) use mass action models to estimate reproductive numbers and the needed control measures. In reality, transmission patterns are more complex due to the presence of various social networks. One level of complexity can be accommodated by considering a community of households. Our study of transmission dynamics in a community of households emphasizes five types of reproductive numbers for the epidemic spread: household-to-h...

  13. Reproductive effort and the egg number vs. size trade-off in Physalaemus frogs (Anura: Leiuperidae)

    Science.gov (United States)

    Camargo, Arley; Sarroca, Macarena; Maneyro, Raúl

    2008-09-01

    Patterns of reproductive allocation are expected to differ between species according to temporally and spatially variable costs of reproduction. Even when reproductive allocation patterns are the same, species can also differ in how the reproductive effort is allocated between offspring number and size. In this study, we compared the reproductive allocation patterns and the offspring number vs. size trade-off in two frog species, Physalaemus biligonigerus and P. gracilis, using bivariate (standardized major axis) and multiple linear regressions. Both species showed a common slope between body size and reproductive effort and thus a similar allocation pattern although P. biligonigerus has a larger body size (shift along common slope) and makes a lower reproductive effort (shift in intercept) than P. gracilis. We suggest that similar allocation patterns may be related to the shared phenologies of these frogs and that the differences in reproductive effort could represent either an adaptive shift (e.g., change in body space for the clutch) or a historical constraint. There was a negative correlation between fecundity and egg size in P. biligonigerus but not in P. gracilis as predicted by the acquisition-allocation model (Y-model). This study constitutes the first valid test of the Y-model based on recent predictions derived for the trade-off between offspring size vs. number. We conclude that future studies should compare reproductive allocation patterns between species using tests of allometric slopes with appropriate phylogenetic control to detect both adaptive shifts in allocation strategies and correlations with other life-history traits.

  14. Characterizing the reproduction number of epidemics with early subexponential growth dynamics

    DEFF Research Database (Denmark)

    Chowell, Gerardo; Viboud, Cécile; Simonsen, Lone

    2016-01-01

    mechanisms. Here, we introduce the generalized growth model to characterize the early growth profile of outbreaks and estimate the effective reproduction number, with no need for explicit assumptions about the shape of epidemic growth. We demonstrate this phenomenological approach using analytical results...... datasets (pandemic influenza, measles, smallpox, bubonic plague, cholera, foot-and-mouth disease, HIV/AIDS and Ebola) with model estimates supporting subexponential growth dynamics. The rapid decline in effective reproduction number predicted by analytical results and observed in real and synthetic......Early estimates of the transmission potential of emerging and re-emerging infections are increasingly used to inform public health authorities on the level of risk posed by outbreaks. Existing methods to estimate the reproduction number generally assume exponential growth in case incidence...

  15. Reproductive numbers, epidemic spread and control in a community of households

    NARCIS (Netherlands)

    Goldstein, E.; Paur, K.; Fraser, C.; Kenah, E.; Wallinga, J.; Lipsitch, M.

    Many of the studies on emerging epidemics (such as SARS and pandemic flu) use mass action models to estimate reproductive numbers and the needed control measures. In reality, transmission patterns are more complex due to the presence of various social networks. One level of complexity can be

  16. Characterizing the reproduction number of epidemics with early subexponential growth dynamics.

    Science.gov (United States)

    Chowell, Gerardo; Viboud, Cécile; Simonsen, Lone; Moghadas, Seyed M

    2016-10-01

    Early estimates of the transmission potential of emerging and re-emerging infections are increasingly used to inform public health authorities on the level of risk posed by outbreaks. Existing methods to estimate the reproduction number generally assume exponential growth in case incidence in the first few disease generations, before susceptible depletion sets in. In reality, outbreaks can display subexponential (i.e. polynomial) growth in the first few disease generations, owing to clustering in contact patterns, spatial effects, inhomogeneous mixing, reactive behaviour changes or other mechanisms. Here, we introduce the generalized growth model to characterize the early growth profile of outbreaks and estimate the effective reproduction number, with no need for explicit assumptions about the shape of epidemic growth. We demonstrate this phenomenological approach using analytical results and simulations from mechanistic models, and provide validation against a range of empirical disease datasets. Our results suggest that subexponential growth in the early phase of an epidemic is the rule rather the exception. Mechanistic simulations show that slight modifications to the classical susceptible-infectious-removed model result in subexponential growth, and in turn a rapid decline in the reproduction number within three to five disease generations. For empirical outbreaks, the generalized-growth model consistently outperforms the exponential model for a variety of directly and indirectly transmitted diseases datasets (pandemic influenza, measles, smallpox, bubonic plague, cholera, foot-and-mouth disease, HIV/AIDS and Ebola) with model estimates supporting subexponential growth dynamics. The rapid decline in effective reproduction number predicted by analytical results and observed in real and synthetic datasets within three to five disease generations contrasts with the expectation of invariant reproduction number in epidemics obeying exponential growth. The

  17. Characterizing the reproduction number of epidemics with early subexponential growth dynamics

    Science.gov (United States)

    Viboud, Cécile; Simonsen, Lone; Moghadas, Seyed M.

    2016-01-01

    Early estimates of the transmission potential of emerging and re-emerging infections are increasingly used to inform public health authorities on the level of risk posed by outbreaks. Existing methods to estimate the reproduction number generally assume exponential growth in case incidence in the first few disease generations, before susceptible depletion sets in. In reality, outbreaks can display subexponential (i.e. polynomial) growth in the first few disease generations, owing to clustering in contact patterns, spatial effects, inhomogeneous mixing, reactive behaviour changes or other mechanisms. Here, we introduce the generalized growth model to characterize the early growth profile of outbreaks and estimate the effective reproduction number, with no need for explicit assumptions about the shape of epidemic growth. We demonstrate this phenomenological approach using analytical results and simulations from mechanistic models, and provide validation against a range of empirical disease datasets. Our results suggest that subexponential growth in the early phase of an epidemic is the rule rather the exception. Mechanistic simulations show that slight modifications to the classical susceptible–infectious–removed model result in subexponential growth, and in turn a rapid decline in the reproduction number within three to five disease generations. For empirical outbreaks, the generalized-growth model consistently outperforms the exponential model for a variety of directly and indirectly transmitted diseases datasets (pandemic influenza, measles, smallpox, bubonic plague, cholera, foot-and-mouth disease, HIV/AIDS and Ebola) with model estimates supporting subexponential growth dynamics. The rapid decline in effective reproduction number predicted by analytical results and observed in real and synthetic datasets within three to five disease generations contrasts with the expectation of invariant reproduction number in epidemics obeying exponential growth. The

  18. Case and partnership reproduction numbers for a curable sexually transmitted infection.

    Science.gov (United States)

    Heijne, Janneke C M; Herzog, Sereina A; Althaus, Christian L; Low, Nicola; Kretzschmar, Mirjam

    2013-08-21

    Sexually transmitted infections (STIs) are, by definition, transmitted between sexual partners. For curable STIs an infected index case can potentially re-infect the same partner multiple times. Thus, R0, the average number of secondary infections one typical infected individual will produce during his or her infectious period is not necessarily the same as the average number of secondary cases (infected persons). Here we introduce the new concept of the case reproduction number (Rc). In addition, we define the partnership reproduction number (Rp) as the average number of secondary partnerships consisting of two infected individuals one typical infected individual will produce over his or her infectious lifetime. Rp takes into account clearance and re-infection within partnerships, which results in a prolongation of the duration of the infectious period. The two new reproduction numbers were derived for a deterministic pair model with serial monogamous partnerships using infection parameters for Chlamydia trachomatis, an example of a curable STI. We showed that re-infection within partnerships means that curable STIs can be sustained endemically even when the average number of secondary cases a person produces during his or her infectious period is below one. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Estimating the reproductive numbers for the 2008-2009 cholera outbreaks in Zimbabwe.

    Science.gov (United States)

    Mukandavire, Zindoga; Liao, Shu; Wang, Jin; Gaff, Holly; Smith, David L; Morris, J Glenn

    2011-05-24

    Cholera remains an important global cause of morbidity and mortality, capable of causing periodic epidemic disease. Beginning in August 2008, a major cholera epidemic occurred in Zimbabwe, with 98,585 reported cases and 4,287 deaths. The dynamics of such outbreaks, particularly in nonestuarine regions, are not well understood. We explored the utility of mathematical models in understanding transmission dynamics of cholera and in assessing the magnitude of interventions necessary to control epidemic disease. Weekly data on reported cholera cases were obtained from the Zimbabwe Ministry of Health and Child Welfare (MoHCW) for the period from November 13, 2008 to July 31, 2009. A mathematical model was formulated and fitted to cumulative cholera cases to estimate the basic reproductive numbers R(0) and the partial reproductive numbers from all 10 provinces for the 2008-2009 Zimbabwe cholera epidemic. Estimated basic reproductive numbers were highly heterogeneous, ranging from a low value of just above unity to 2.72. Partial reproductive numbers were also highly heterogeneous, suggesting that the transmission routes varied by province; human-to-human transmission accounted for 41-95% of all transmission. Our models suggest that the underlying patterns of cholera transmission varied widely from province to province, with a corresponding variation in the amenability of outbreaks in different provinces to control measures such as immunization. These data underscore the heterogeneity of cholera transmission dynamics, potentially linked to differences in environment, socio-economic conditions, and cultural practices. The lack of traditional estuarine reservoirs combined with these estimates of R(0) suggest that mass vaccination against cholera deployed strategically in Zimbabwe and surrounding regions could prevent future cholera epidemics and eventually eliminate cholera from the region.

  20. Fermion number in supersymmetric models

    International Nuclear Information System (INIS)

    Mainland, G.B.; Tanaka, K.

    1975-01-01

    The two known methods for introducing a conserved fermion number into supersymmetric models are discussed. While the introduction of a conserved fermion number often requires that the Lagrangian be massless or that bosons carry fermion number, a model is discussed in which masses can be introduced via spontaneous symmetry breaking and fermion number is conserved at all stages without assigning fermion number to bosons. (U.S.)

  1. Are reproductive skew models evolutionarily stable?

    OpenAIRE

    Kokko, Hanna

    2003-01-01

    Reproductive skew theory has become a popular way to phrase problems and test hypotheses of social evolution. The diversity of reproductive skew models probably stems from the ease of generating new variations. However, I show that the logical basis of skew models, that is, the way in which group formation is modelled, makes use of hidden assumptions that may be problematical as they are unlikely to be fulfilled in all social systems. I illustrate these problems by re-analysing the basic conc...

  2. The reproductive value in distributed optimal control models.

    Science.gov (United States)

    Wrzaczek, Stefan; Kuhn, Michael; Prskawetz, Alexia; Feichtinger, Gustav

    2010-05-01

    We show that in a large class of distributed optimal control models (DOCM), where population is described by a McKendrick type equation with an endogenous number of newborns, the reproductive value of Fisher shows up as part of the shadow price of the population. Depending on the objective function, the reproductive value may be negative. Moreover, we show results of the reproductive value for changing vital rates. To motivate and demonstrate the general framework, we provide examples in health economics, epidemiology, and population biology.

  3. QSAR Models for Reproductive Toxicity and Endocrine Disruption Activity

    Directory of Open Access Journals (Sweden)

    Marjan Vračko

    2010-03-01

    Full Text Available Reproductive toxicity is an important regulatory endpoint, which is required in registration procedures of chemicals used for different purposes (for example pesticides. The in vivo tests are expensive, time consuming and require large numbers of animals, which must be sacrificed. Therefore an effort is ongoing to develop alternative In vitro and in silico methods to evaluate reproductive toxicity. In this review we describe some modeling approaches. In the first example we describe the CAESAR model for prediction of reproductive toxicity; the second example shows a classification model for endocrine disruption potential based on counter propagation artificial neural networks; the third example shows a modeling of relative binding affinity to rat estrogen receptor, and the fourth one shows a receptor dependent modeling experiment.

  4. Are reproductive skew models evolutionarily stable?

    Science.gov (United States)

    Kokko, Hanna

    2003-02-07

    Reproductive skew theory has become a popular way to phrase problems and test hypotheses of social evolution. The diversity of reproductive skew models probably stems from the ease of generating new variations. However, I show that the logical basis of skew models, that is, the way in which group formation is modelled, makes use of hidden assumptions that may be problematical as they are unlikely to be fulfilled in all social systems. I illustrate these problems by re-analysing the basic concessive skew model with staying incentives. First, the model assumes that dispersal is an all-or-nothing response: all subordinates disperse as soon as concessions drop below a certain value. This leads to a discontinuous 'cliff-edge' shape of dominant fitness, and it is not clear that selection will balance a population at such an edge. Second, it is assumed that subordinates have perfect knowledge of their benefits if they stay in the group. I examine the effects of relaxing these two assumptions. Relaxing the first one strengthens reproductive skew theory, but relaxing the latter makes evolutionary stability disappear. In cases where subordinates cannot accurately measure benefits provided by the individual dominant with which they live, so that their behaviour instead evolves as a response to population-wide average benefits, the logic of reproductive skew models does not apply. This warns against too indiscriminate an application of reproductive skew theory to problems in social evolution: for example, transactional models of extra-pair paternity assume perfect knowledge of paternity, which is unlikely to hold true in nature. It is recommended that models specify the mechanisms by which individuals can adjust their behaviour to that of others, and pay attention to changes that occur in evolutionary versus behavioural time.

  5. The final size of an epidemic and its relation to the basic reproduction number

    DEFF Research Database (Denmark)

    Andreasen, Viggo

    2011-01-01

    reproduction number R00: There is a unique positive solution giving the size of the epidemic if and only if R00 exceeds unity. When mixing heterogeneities arise only from variation in contact rates and proportionate mixing, the final size of the epidemic in a heterogeneously mixing population is always smaller...... than that in a homogeneously mixing population with the same basic reproduction number R00. For other mixing patterns, the relation may be reversed....

  6. Estimating dengue type reproduction numbers for two provinces of Sri Lanka during the period 2013-14.

    Science.gov (United States)

    Sardar, Tridip; Sasmal, Sourav Kumar; Chattopadhyay, Joydev

    2016-01-01

    Dengue is an endemic disease in the southeast Asian country Sri Lanka. Two seasonal peaks of dengue incidence were observed every year since 2002 onwards. In this study, we formulate a 2-strain dengue model for analyzing the monthly seasonal dengue incidence data from 2 provinces of Sri Lanka during the period April 2013 to September 2014. The seasonality is incorporated in the model in terms of mosquito biting rate, which we assume to be time periodic. We estimated 2 primary reproduction numbers and the basic reproduction number in a periodic environment using dengue incidence data from the western and the central provinces of Sri Lanka. We also estimated different time-average type reproduction numbers from the model using the data from these 2 provinces. Using univariate sensitivity analysis, we measured the sensitivity of the time average reproduction number ([Formula: see text]) When we vary different parameters of the proposed dengue model, we find the transmission probability of human susceptibility to strain-I infection and the mosquito mortality rate parameters are the most sensitive parameters in dengue transmission in these 2 provinces.

  7. Basic Reproduction Number and Transmission Dynamics of Common Serogroups of Enterohemorrhagic Escherichia coli.

    Science.gov (United States)

    Chen, Shi; Sanderson, Michael W; Lee, Chihoon; Cernicchiaro, Natalia; Renter, David G; Lanzas, Cristina

    2016-09-15

    Understanding the transmission dynamics of pathogens is essential to determine the epidemiology, ecology, and ways of controlling enterohemorrhagic Escherichia coli (EHEC) in animals and their environments. Our objective was to estimate the epidemiological fitness of common EHEC strains in cattle populations. For that purpose, we developed a Markov chain model to characterize the dynamics of 7 serogroups of enterohemorrhagic Escherichia coli (O26, O45, O103, O111, O121, O145, and O157) in cattle production environments based on a set of cross-sectional data on infection prevalence in 2 years in two U.S. states. The basic reproduction number (R0) was estimated using a Bayesian framework for each serogroup based on two criteria (using serogroup alone [the O-group data] and using O serogroup, Shiga toxin gene[s], and intimin [eae] gene together [the EHEC data]). In addition, correlations between external covariates (e.g., location, ambient temperature, dietary, and probiotic usage) and prevalence/R0 were quantified. R0 estimates varied substantially among different EHEC serogroups, with EHEC O157 having an R0 of >1 (∼1.5) and all six other EHEC serogroups having an R0 of less than 1. Using the O-group data substantially increased R0 estimates for the O26, O45, and O103 serogroups (R0 > 1) but not for the others. Different covariates had distinct influences on different serogroups: the coefficients for each covariate were different among serogroups. Our modeling and analysis of this system can be readily expanded to other pathogen systems in order to estimate the pathogen and external factors that influence spread of infectious agents. In this paper we describe a Bayesian modeling framework to estimate basic reproduction numbers of multiple serotypes of Shiga toxin-producing Escherichia coli according to a cross-sectional study. We then coupled a compartmental model to reconstruct the infection dynamics of these serotypes and quantify their risk in the population. We

  8. A critical number of workers in a honeybee colony triggers investment in reproduction.

    Science.gov (United States)

    Smith, Michael L; Ostwald, Madeleine M; Loftus, J Carter; Seeley, Thomas D

    2014-10-01

    Social insect colonies, like individual organisms, must decide as they develop how to allocate optimally their resources among survival, growth, and reproduction. Only when colonies reach a certain state do they switch from investing purely in survival and growth to investing also in reproduction. But how do worker bees within a colony detect that their colony has reached the state where it is adaptive to begin investing in reproduction? Previous work has shown that larger honeybee colonies invest more in reproduction (i.e., the production of drones and queens), however, the term 'larger' encompasses multiple colony parameters including number of adult workers, size of the nest, amount of brood, and size of the honey stores. These colony parameters were independently increased in this study to test which one(s) would increase a colony's investment in reproduction via males. This was assayed by measuring the construction of drone comb, the special type of comb in which drones are reared. Only an increase in the number of workers stimulated construction of drone comb. Colonies with over 4,000 workers began building drone comb, independent of the other colony parameters. These results show that attaining a critical number of workers is the key parameter for honeybee colonies to start to shift resources towards reproduction. These findings are relevant to other social systems in which a group's members must adjust their behavior as a function of the group's size.

  9. Estimation of basic reproductive number of flu-like syndrome in a primary school in Iran

    Directory of Open Access Journals (Sweden)

    AliAkbar Haghdoost

    2012-01-01

    Full Text Available Introduction: Iran, similar to other countries, had faced H1N1 flu outbreak in 2009. In order to assess its transmission dynamic, we estimated its force of infection (β and basic reproductive number (R 0 . Methods: Within a middle size primary school in Iran, we actively followed students and detected flu-like syndrome among students and their families in the first three months of academic year; October through December 2009. We estimated the probability of disease transmission within families (β fitting random effects Poisson regression model. Moreover, R 0 within the school was computed based on the number of detected cases. Results: In 452 students, 204 influenza-like syndromes were detected. The estimated β within families was 0.10; increasing one infectious member within each family was associated with 30% increase in this number. The estimated R 0 for the first month was 1.21 (95% C.I.: 0.99, 1.47; corresponding numbers for the first two and first three months were 1.28 (95% C.I.: 1.05, 1.54 and 1.32 (95% C.I.: 1.11, 1.59, respectively. Conclusion: It seems that the dynamic transmission of H1N1 virus was more or less comparable with that in other seasonal species. Our findings showed that the virus mainly circulated among students within schools. In addition, it seems that the transmission rate within families was relatively high.

  10. Vector-borne diseases: the basic reproduction number R0 and risk maps

    NARCIS (Netherlands)

    Hartemink, N.A.

    2009-01-01

    This thesis deals with the derivation of the basic reproduction number (R0) for vector-borne diseases, in the context of studying the effect of climate change on the risk of emergence diseases. Vector-borne diseases are transmitted from an infected individual to another individual by vectors,

  11. Multiscale Systems Modeling of Male Reproductive Tract ...

    Science.gov (United States)

    The reproductive tract is a complex, integrated organ system with diverse embryology and unique sensitivity to prenatal environmental exposures that disrupt morphoregulatory processes and endocrine signaling. U.S. EPA’s in vitro high-throughput screening (HTS) database (ToxCastDB) was used to profile the bioactivity of 54 chemicals with male developmental consequences across ~800 molecular and cellular features [Leung et al., accepted manuscript]. The in vitro bioactivity on molecular targets could be condensed into 156 gene annotations in a bipartite network. These results highlighted the role of estrogen and androgen signaling pathways in male reproductive tract development, and importantly, broadened the list of molecular targets to include GPCRs, cytochrome-P450s, vascular remodeling proteins, and retinoic acid signaling. A multicellular agent-based model was used to simulate the complex interactions between morphoregulatory, endocrine, and environmental influences during genital tubercle (GT) development. Spatially dynamic signals (e.g., SHH, FGF10, and androgen) were implemented in the model to address differential adhesion, cell motility, proliferation, and apoptosis. Urethral tube closure was an emergent feature of the model that was linked to gender-specific rates of ventral mesenchymal proliferation and urethral plate endodermal apoptosis, both under control of androgen signaling [Leung et al., manuscript in preparation]. A systemic parameter sweep w

  12. A Dynamic Model of Cultural Reproduction

    DEFF Research Database (Denmark)

    Jæger, Mads Meier; Breen, Richard

    2016-01-01

    of study. Their model describes how parents transmit cultural capital to their children and how children convert cultural capital into educational success. It also provides a behavioral framework for interpreting parental investments in cultural capital. The authors review results from existing empirical......The authors draw on Pierre Bourdieu’s theory of cultural reproduction to develop a formal model of the pathways through which cultural capital acts to enhance children’s educational and socioeconomic success. The authors’ approach brings conceptual and empirical clarity to an important area...... research on the role of cultural capital in education to demonstrate the usefulness of their model for interpretative purposes, and they use National Longitudinal Survey of Youth 1979—Children and Young Adults survey data to test some of its implications....

  13. Modeling reproductive decisions with simple heuristics

    Directory of Open Access Journals (Sweden)

    Peter Todd

    2013-10-01

    Full Text Available BACKGROUND Many of the reproductive decisions that humans make happen without much planning or forethought, arising instead through the use of simple choice rules or heuristics that involve relatively little information and processing. Nonetheless, these heuristic-guided decisions are typically beneficial, owing to humans' ecological rationality - the evolved fit between our constrained decision mechanisms and the adaptive problems we face. OBJECTIVE This paper reviews research on the ecological rationality of human decision making in the domain of reproduction, showing how fertility-related decisions are commonly made using various simple heuristics matched to the structure of the environment in which they are applied, rather than being made with information-hungry mechanisms based on optimization or rational economic choice. METHODS First, heuristics for sequential mate search are covered; these heuristics determine when to stop the process of mate search by deciding that a good-enough mate who is also mutually interested has been found, using a process of aspiration-level setting and assessing. These models are tested via computer simulation and comparison to demographic age-at-first-marriage data. Next, a heuristic process of feature-based mate comparison and choice is discussed, in which mate choices are determined by a simple process of feature-matching with relaxing standards over time. Parental investment heuristics used to divide resources among offspring are summarized. Finally, methods for testing the use of such mate choice heuristics in a specific population over time are then described.

  14. From Concurrency Models to Numbers

    DEFF Research Database (Denmark)

    Hermanns, Holger; Zhang, Lijun

    2011-01-01

    Discrete-state Markov processes are very common models used for performance and dependability evaluation of, for example, distributed information and communication systems. Over the last fifteen years, compositional model construction and model checking algorithms have been studied for these proc...

  15. Are there optimal numbers of oocytes, spermatozoa and embryos in assisted reproduction?

    Science.gov (United States)

    Milachich, Tanya; Shterev, Atanas

    2016-08-01

    The aim of this overview is to discuss the current information about the search for the optimum yield of gametes in assisted reproduction, as one of the major pillars of IVF success. The first topic is focused on the number of male gametes and the possible impact of some genetic traits on these parameters. The number of spermatozoa did not seem to be crucial when there is no severe male factor of infertility. Genetic testing prior to using those sperm cells is very important. Different methods were applied in order to elect the "best" spermatozoa according to specific indications. The next problem discussed is the importance of the number of oocytes collected. Several studies have agreed that "15 oocytes is the perfect number," as the number of mature oocytes is more important. However, if elective single embryo transfer is performed, the optimal number of oocytes will enable a proper embryo selection. The third problem discussed concerns fertility preservation. Many educational programs promote and encourage procreation at maternal ages between 20-35 years, since assisted reproduction is unable to fully overcome the effects of female aging and fertility loss after that age. It is also strongly recommended to ensure a reasonable number of cryopreserved mature oocytes, preferably in younger ages (<35), for which an average of two stimulation cycles are likely required. For embryo cryopreservation, the "freeze all" strategy suggests the vitrification of good embryos, therefore quality is prior to number and patient recruitment for this strategy should be performed cautiously.

  16. Temperature modulates dengue virus epidemic growth rates through its effects on reproduction numbers and generation intervals.

    Science.gov (United States)

    Siraj, A. S.; Oidtman, R. J.; Huber, J. H.; Kraemer, M. U.; Brady, O. J.; Johansson, M. A.; Perkins, T. A.

    2017-12-01

    Epidemic growth rate, r, provides a more complete description of the potential for epidemics than the more commonly studied basic reproduction number, R0, yet the former has never been described as a function of temperature for dengue virus or other pathogens with temperature-sensitive transmission. The need to understand the drivers of epidemics of these pathogens is acute, with arthropod-borne virus epidemics becoming increasingly problematic. We addressed this need by developing temperature-dependent descriptions of the two components of r—R0 and the generation interval—to obtain a temperature-dependent description of r. Our results show that the generation interval is highly sensitive to temperature, decreasing twofold between 25 and 35 °C and suggesting that dengue virus epidemics may accelerate as temperatures increase, not only because of more infections per generation but also because of faster generations. Under the empirical temperature relationships that we considered, we found that r peaked at a temperature threshold that was robust to uncertainty in model parameters that do not depend on temperature. Although the precise value of this temperature threshold could be refined following future studies of empirical temperature relationships, the framework we present for identifying such temperature thresholds offers a new way to classify regions in which dengue virus epidemic intensity could either increase or decrease under future climate change.

  17. The basic reproduction number (R0) of measles: a systematic review.

    Science.gov (United States)

    Guerra, Fiona M; Bolotin, Shelly; Lim, Gillian; Heffernan, Jane; Deeks, Shelley L; Li, Ye; Crowcroft, Natasha S

    2017-12-01

    The basic reproduction number, R nought (R 0 ), is defined as the average number of secondary cases of an infectious disease arising from a typical case in a totally susceptible population, and can be estimated in populations if pre-existing immunity can be accounted for in the calculation. R 0 determines the herd immunity threshold and therefore the immunisation coverage required to achieve elimination of an infectious disease. As R 0 increases, higher immunisation coverage is required to achieve herd immunity. In July, 2010, a panel of experts convened by WHO concluded that measles can and should be eradicated. Despite the existence of an effective vaccine, regions have had varying success in measles control, in part because measles is one of the most contagious infections. For measles, R 0 is often cited to be 12-18, which means that each person with measles would, on average, infect 12-18 other people in a totally susceptible population. We did a systematic review to find studies reporting rigorous estimates and determinants of measles R 0 . Studies were included if they were a primary source of R 0 , addressed pre-existing immunity, and accounted for pre-existing immunity in their calculation of R 0 . A search of key databases was done in January, 2015, and repeated in November, 2016, and yielded 10 883 unique citations. After screening for relevancy and quality, 18 studies met inclusion criteria, providing 58 R 0 estimates. We calculated median measles R 0 values stratified by key covariates. We found that R 0 estimates vary more than the often cited range of 12-18. Our results highlight the importance of countries calculating R 0 using locally derived data or, if this is not possible, using parameter estimates from similar settings. Additional data and agreed review methods are needed to strengthen the evidence base for measles elimination modelling. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. The concentration of plasma metabolites varies throughout reproduction and affects offspring number in wild brown trout (Salmo trutta).

    Science.gov (United States)

    Gauthey, Zoé; Freychet, Marine; Manicki, Aurélie; Herman, Alexandre; Lepais, Olivier; Panserat, Stéphane; Elosegi, Arturo; Tentelier, Cédric; Labonne, Jacques

    2015-06-01

    In wild populations, measuring energy invested in the reproduction and disentangling investment in gametes versus investment in reproductive behavior (such as intrasexual competition or intersexual preference) remain challenging. In this study, we investigated the energy expenditure in brown trout reproductive behavior by using two proxies: variation in weight and variation of plasma metabolites involved in energy production, over the course of reproductive season in a semi natural experimental river. We estimated overall reproductive success using genetic assignment at the end of the reproductive season. Results show that triglycerides and free fatty acid concentrations vary negatively during reproduction, while amino-acids and glucose concentrations remain stable. Decrease in triglyceride and free fatty acid concentrations during reproduction is not related to initial concentration levels or to weight variation. Both metabolite concentration variations and weight variations are correlated to the number of offspring produced, which could indicate that gametic and behavioral reproductive investments substantially contribute to reproductive success in wild brown trout. This study opens a path to further investigate variations in reproductive investment in wild populations. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Habitat fragmentation and reproductive success: a structural equation modelling approach.

    Science.gov (United States)

    Le Tortorec, Eric; Helle, Samuli; Käyhkö, Niina; Suorsa, Petri; Huhta, Esa; Hakkarainen, Harri

    2013-09-01

    1. There is great interest on the effects of habitat fragmentation, whereby habitat is lost and the spatial configuration of remaining habitat patches is altered, on individual breeding performance. However, we still lack consensus of how this important process affects reproductive success, and whether its effects are mainly due to reduced fecundity or nestling survival. 2. The main reason for this may be the way that habitat fragmentation has been previously modelled. Studies have treated habitat loss and altered spatial configuration as two independent processes instead of as one hierarchical and interdependent process, and therefore have not been able to consider the relative direct and indirect effects of habitat loss and altered spatial configuration. 3. We investigated how habitat (i.e. old forest) fragmentation, caused by intense forest harvesting at the territory and landscape scales, is associated with the number of fledged offspring of an area-sensitive passerine, the Eurasian treecreeper (Certhia familiaris). We used structural equation modelling (SEM) to examine the complex hierarchical associations between habitat loss and altered spatial configuration on the number of fledged offspring, by controlling for individual condition and weather conditions during incubation. 4. Against generally held expectations, treecreeper reproductive success did not show a significant association with habitat fragmentation measured at the territory scale. Instead, our analyses suggested that an increasing amount of habitat at the landscape scale caused a significant increase in nest predation rates, leading to reduced reproductive success. This effect operated directly on nest predation rates, instead of acting indirectly through altered spatial configuration. 5. Because habitat amount and configuration are inherently strongly collinear, particularly when multiple scales are considered, our study demonstrates the usefulness of a SEM approach for hierarchical partitioning

  20. Estimation of basic reproduction number of the Middle East respiratory syndrome coronavirus (MERS-CoV) during the outbreak in South Korea, 2015.

    Science.gov (United States)

    Chang, Hyuk-Jun

    2017-06-13

    In South Korea, an outbreak of Middle East respiratory syndrome (MERS) occurred in 2015. It was the second largest MERS outbreak. As a result of the outbreak in South Korea, 186 infections were reported, and 36 patients died. At least 16,693 people were isolated with suspicious symptoms. This paper estimates the basic reproduction number of the MERS coronavirus (CoV), using data on the spread of MERS in South Korea. The basic reproduction number of an epidemic is defined as the average number of secondary cases that an infected subject produces over its infectious period in a susceptible and uninfected population. To estimate the basic reproduction number of the MERS-CoV, we employ data from the 2015 South Korea MERS outbreak and the susceptible-infected-removed (SIR) model, a mathematical model that uses a set of ordinary differential equations (ODEs). We fit the model to the epidemic data of the South Korea outbreak minimizing the sum of the squared errors to identify model parameters. Also we derive the basic reproductive number as the terms of the parameters of the SIR model. Then we determine the basic reproduction number of the MERS-CoV in South Korea in 2015 as 8.0977. It is worth comparing with the basic reproductive number of the 2014 Ebola outbreak in West Africa including Guinea, Sierra Leone, and Liberia, which had values of 1.5-2.5. There was no intervention to control the infection in the early phase of the outbreak, thus the data used here provide the best conditions to evaluate the epidemic characteristics of MERS, such as the basic reproduction number. An evaluation of basic reproduction number using epidemic data could be problematic if there are stochastic fluctuations in the early phase of the outbreak, or if the report is not accurate and there is bias in the data. Such problems are not relevant to this study because the data used here were precisely reported and verified by Korea Hospital Association.

  1. Zika in Rio de Janeiro: Assessment of basic reproduction number and comparison with dengue outbreaks.

    Science.gov (United States)

    Villela, D A M; Bastos, L S; DE Carvalho, L M; Cruz, O G; Gomes, M F C; Durovni, B; Lemos, M C; Saraceni, V; Coelho, F C; Codeço, C T

    2017-06-01

    Zika virus infection was declared a public health emergency of international concern in February 2016 in response to the outbreak in Brazil and its suspected link with congenital anomalies. In this study, we use notification data and disease natural history parameters to estimate the basic reproduction number (R 0) of Zika in Rio de Janeiro, Brazil. We also obtain estimates of R 0 of dengue from time series of dengue cases in the outbreaks registered in 2002 and 2012 in the city, when DENV-3 and DENV-4 serotypes, respectively, had just emerged. Our estimates of the basic reproduction number for Zika in Rio de Janeiro based on surveillance notifications (R 0 = 2·33, 95% CI: 1·97-2·97) were higher than those obtained for dengue in the city (year 2002: R 0 = 1·70 [1·50-2·02]; year 2012: R 0 = 1·25 [1·18-1·36]). Given the role of Aedes aegypti as vector of both the Zika and dengue viruses, we also derive R 0 of Zika as a function of both dengue reproduction number and entomological and epidemiological parameters for dengue and Zika. Using the dengue outbreaks from previous years allowed us to estimate the potential R 0 of Zika. Our estimates were closely in agreement with our first Zika's R 0 estimation from notification data. Hence, these results validate deriving the potential risk of Zika transmission in areas with recurring dengue outbreaks. Whether transmission routes other than vector-based can sustain a Zika epidemic still deserves attention, but our results suggest that the Zika outbreak in Rio de Janeiro emerged due to population susceptibility and ubiquitous presence of Ae. aegypti.

  2. Lifetime number of mates interacts with female age to determine reproductive success in female guppies.

    Directory of Open Access Journals (Sweden)

    Jonathan P Evans

    Full Text Available In many species, mating with multiple males confers benefits to females, but these benefits may be offset by the direct and indirect costs associated with elevated mating frequency. Although mating frequency (number of mating events is often positively associated with the degree of multiple mating (actual number of males mated, most studies have experimentally separated these effects when exploring their implications for female fitness. In this paper I describe an alternative approach using the guppy Poecilia reticulata, a livebearing freshwater fish in which females benefit directly and indirectly from mating with multiple males via consensual matings but incur direct and indirect costs of mating as a consequence of male sexual harassment. In the present study, females were experimentally assigned different numbers of mates throughout their lives in order to explore how elevated mating frequency and multiple mating combine to influence lifetime reproductive success (LRS and survival (i.e. direct components of female fitness. Under this mating design, survival and LRS were not significantly affected by mating treatment, but there was a significant interaction between brood size and reproductive cycle (a correlate of female age because females assigned to the high mating treatment produced significantly fewer offspring later in life compared to their low-mating counterparts. This negative effect of mating treatment later in life may be important in these relatively long-lived fishes, and this effect may be further exacerbated by the known cross-generational fitness costs of sexual harassment in guppies.

  3. Lifetime number of mates interacts with female age to determine reproductive success in female guppies.

    Science.gov (United States)

    Evans, Jonathan P

    2012-01-01

    In many species, mating with multiple males confers benefits to females, but these benefits may be offset by the direct and indirect costs associated with elevated mating frequency. Although mating frequency (number of mating events) is often positively associated with the degree of multiple mating (actual number of males mated), most studies have experimentally separated these effects when exploring their implications for female fitness. In this paper I describe an alternative approach using the guppy Poecilia reticulata, a livebearing freshwater fish in which females benefit directly and indirectly from mating with multiple males via consensual matings but incur direct and indirect costs of mating as a consequence of male sexual harassment. In the present study, females were experimentally assigned different numbers of mates throughout their lives in order to explore how elevated mating frequency and multiple mating combine to influence lifetime reproductive success (LRS) and survival (i.e. direct components of female fitness). Under this mating design, survival and LRS were not significantly affected by mating treatment, but there was a significant interaction between brood size and reproductive cycle (a correlate of female age) because females assigned to the high mating treatment produced significantly fewer offspring later in life compared to their low-mating counterparts. This negative effect of mating treatment later in life may be important in these relatively long-lived fishes, and this effect may be further exacerbated by the known cross-generational fitness costs of sexual harassment in guppies.

  4. Lifetime Number of Mates Interacts with Female Age to Determine Reproductive Success in Female Guppies

    Science.gov (United States)

    Evans, Jonathan P.

    2012-01-01

    In many species, mating with multiple males confers benefits to females, but these benefits may be offset by the direct and indirect costs associated with elevated mating frequency. Although mating frequency (number of mating events) is often positively associated with the degree of multiple mating (actual number of males mated), most studies have experimentally separated these effects when exploring their implications for female fitness. In this paper I describe an alternative approach using the guppy Poecilia reticulata, a livebearing freshwater fish in which females benefit directly and indirectly from mating with multiple males via consensual matings but incur direct and indirect costs of mating as a consequence of male sexual harassment. In the present study, females were experimentally assigned different numbers of mates throughout their lives in order to explore how elevated mating frequency and multiple mating combine to influence lifetime reproductive success (LRS) and survival (i.e. direct components of female fitness). Under this mating design, survival and LRS were not significantly affected by mating treatment, but there was a significant interaction between brood size and reproductive cycle (a correlate of female age) because females assigned to the high mating treatment produced significantly fewer offspring later in life compared to their low-mating counterparts. This negative effect of mating treatment later in life may be important in these relatively long-lived fishes, and this effect may be further exacerbated by the known cross-generational fitness costs of sexual harassment in guppies. PMID:23071816

  5. Reproductive Behavior and Personality Traits of the Five Factor Model

    NARCIS (Netherlands)

    Jokela, Markus; Alvergne, Alexandra; Pollet, Thomas V.; Lummaa, Virpi

    2011-01-01

    We examined associations between Five Factor Model personality traits and various outcomes of reproductive behavior in a sample of 15 729 women and men from the Wisconsin Longitudinal Study (WLS) and Midlife Development in the United States (MIDUS) survey. Personality and reproductive history was

  6. Introduction to Animal Reproduction. Instructor Guide [and] Student Reference. Volume 28, Number 5 [and] Volume 28, Number 6.

    Science.gov (United States)

    Peiter, Andrea; And Others

    This instructor guide and the corresponding student reference contain seven lessons about animal reproduction for inclusion in Vocational Instructional Management System (VIMS) agricultural education courses. The lessons cover the following topics: the male and female reproductive systems, puberty and the estrous cycle, conception and gestation,…

  7. Reproduction Number and Asymptotic Stability for the Dynamics of a Honey Bee Colony with Continuous Age Structure.

    Science.gov (United States)

    Betti, M I; Wahl, L M; Zamir, M

    2017-07-01

    A system of partial differential equations is derived as a model for the dynamics of a honey bee colony with a continuous age distribution, and the system is then extended to include the effects of a simplified infectious disease. In the disease-free case, we analytically derive the equilibrium age distribution within the colony and propose a novel approach for determining the global asymptotic stability of a reduced model. Furthermore, we present a method for determining the basic reproduction number [Formula: see text] of the infection; the method can be applied to other age-structured disease models with interacting susceptible classes. The results of asymptotic stability indicate that a honey bee colony suffering losses will recover naturally so long as the cause of the losses is removed before the colony collapses. Our expression for [Formula: see text] has potential uses in the tracking and control of an infectious disease within a bee colony.

  8. Models to study gravitational biology of Mammalian reproduction

    Science.gov (United States)

    Tou, Janet; Ronca, April; Grindeland, Richard; Wade, Charles

    2002-01-01

    Mammalian reproduction evolved within Earth's 1-g gravitational field. As we move closer to the reality of space habitation, there is growing scientific interest in how different gravitational states influence reproduction in mammals. Habitation of space and extended spaceflight missions require prolonged exposure to decreased gravity (hypogravity, i.e., weightlessness). Lift-off and re-entry of the spacecraft are associated with exposure to increased gravity (hypergravity). Existing data suggest that spaceflight is associated with a constellation of changes in reproductive physiology and function. However, limited spaceflight opportunities and confounding effects of various nongravitational factors associated with spaceflight (i.e., radiation, stress) have led to the development of ground-based models for studying the effects of altered gravity on biological systems. Human bed rest and rodent hindlimb unloading paradigms are used to study exposure to hypogravity. Centrifugation is used to study hypergravity. Here, we review the results of spaceflight and ground-based models of altered gravity on reproductive physiology. Studies utilizing ground-based models that simulate hyper- and hypogravity have produced reproductive results similar to those obtained from spaceflight and are contributing new information on biological responses across the gravity continuum, thereby confirming the appropriateness of these models for studying reproductive responses to altered gravity and the underlying mechanisms of these responses. Together, these unique tools are yielding new insights into the gravitational biology of reproduction in mammals.

  9. Cancer susceptibility and reproductive trade-offs: a model of the evolution of cancer defences.

    Science.gov (United States)

    Boddy, Amy M; Kokko, Hanna; Breden, Felix; Wilkinson, Gerald S; Aktipis, C Athena

    2015-07-19

    The factors influencing cancer susceptibility and why it varies across species are major open questions in the field of cancer biology. One underexplored source of variation in cancer susceptibility may arise from trade-offs between reproductive competitiveness (e.g. sexually selected traits, earlier reproduction and higher fertility) and cancer defence. We build a model that contrasts the probabilistic onset of cancer with other, extrinsic causes of mortality and use it to predict that intense reproductive competition will lower cancer defences and increase cancer incidence. We explore the trade-off between cancer defences and intraspecific competition across different extrinsic mortality conditions and different levels of trade-off intensity, and find the largest effect of competition on cancer in species where low extrinsic mortality combines with strong trade-offs. In such species, selection to delay cancer and selection to outcompete conspecifics are both strong, and the latter conflicts with the former. We discuss evidence for the assumed trade-off between reproductive competitiveness and cancer susceptibility. Sexually selected traits such as ornaments or large body size require high levels of cell proliferation and appear to be associated with greater cancer susceptibility. Similar associations exist for female traits such as continuous egg-laying in domestic hens and earlier reproductive maturity. Trade-offs between reproduction and cancer defences may be instantiated by a variety of mechanisms, including higher levels of growth factors and hormones, less efficient cell-cycle control and less DNA repair, or simply a larger number of cell divisions (relevant when reproductive success requires large body size or rapid reproductive cycles). These mechanisms can affect intra- and interspecific variation in cancer susceptibility arising from rapid cell proliferation during reproductive maturation, intrasexual competition and reproduction. © 2015 The Author

  10. Cancer susceptibility and reproductive trade-offs: a model of the evolution of cancer defences

    Science.gov (United States)

    Boddy, Amy M.; Kokko, Hanna; Breden, Felix; Wilkinson, Gerald S.; Aktipis, C. Athena

    2015-01-01

    The factors influencing cancer susceptibility and why it varies across species are major open questions in the field of cancer biology. One underexplored source of variation in cancer susceptibility may arise from trade-offs between reproductive competitiveness (e.g. sexually selected traits, earlier reproduction and higher fertility) and cancer defence. We build a model that contrasts the probabilistic onset of cancer with other, extrinsic causes of mortality and use it to predict that intense reproductive competition will lower cancer defences and increase cancer incidence. We explore the trade-off between cancer defences and intraspecific competition across different extrinsic mortality conditions and different levels of trade-off intensity, and find the largest effect of competition on cancer in species where low extrinsic mortality combines with strong trade-offs. In such species, selection to delay cancer and selection to outcompete conspecifics are both strong, and the latter conflicts with the former. We discuss evidence for the assumed trade-off between reproductive competitiveness and cancer susceptibility. Sexually selected traits such as ornaments or large body size require high levels of cell proliferation and appear to be associated with greater cancer susceptibility. Similar associations exist for female traits such as continuous egg-laying in domestic hens and earlier reproductive maturity. Trade-offs between reproduction and cancer defences may be instantiated by a variety of mechanisms, including higher levels of growth factors and hormones, less efficient cell-cycle control and less DNA repair, or simply a larger number of cell divisions (relevant when reproductive success requires large body size or rapid reproductive cycles). These mechanisms can affect intra- and interspecific variation in cancer susceptibility arising from rapid cell proliferation during reproductive maturation, intrasexual competition and reproduction. PMID:26056364

  11. reproduction

    African Journals Online (AJOL)

    and research, such as human reproductive cloning.“ However, despite advances in ART the proportion of ... religions such as Islam completely forbid them, and in many countries there is strict regulation of treatment. Although sperm cryopreservation in humans was introduced in 1953,13 sperm donation commenced using.

  12. The "vanishing follicle" in women with low number of developing follicles during assisted reproduction.

    Science.gov (United States)

    Younis, Johnny S; Yakovi, Shiran; Izhaki, Ido; Haddad, Sami; Ben-Ami, Moshe

    2018-01-01

    To investigate the occurrence of the "vanishing follicle" phenomenon in women with low number of developing follicles in assisted reproduction. Women with ≤ 6 follicles on the day of hCG administration with ≥ 14mm diameter were prospectively studied. Primary outcome measures were disappearance of ≥14mm and all-diameter follicles on the day of oocyte pick-up compared to the day of hCG administration. Among the 120 women recruited, 95 were found eligible and completed the study. The "vanishing follicle" phenomenon occurred in 3.1% (95% confidence level: 0.7%-9.0%) and 18.9% (95% confidence level: 11.6%-28.3%) of cases affecting ≥14mm and all-diameter follicles, respectively. In all cases, mid-late follicular serum LH and P levels remained within normal follicular phase range and trans-vaginal scan did not show signs of ovulation. Markedly, the main significant difference between the study and control groups in the ≥14mm follicle group was serum E 2 level on the day of hCG administration; median (Interquartile range), corresponding to 395 (382.0-405.5) versus 823.0 (544.5-1291.0) pg/mL, respectively (P=0.04). The same trend was encountered in all-diameter vanishing follicles group but it did not reach significance. Interestingly, in all-diameter vanishing group, chronic smoking and the P/E 2 ratio on the hCG day were significantly higher than controls. Post hoc multiple logistic regression analysis of data in accordance with the Bologna criteria reveled that antral follicle count was found to significantly affect the development of the "vanishing follicle" phenomenon. The "vanishing follicle" phenomenon occasionally occurs in women with low number of developing follicles during assisted reproduction with no signs of ovulation. Our preliminary findings suggest that this phenomenon may be related to exhausted ovarian reserve however, an early-unrecognized LH elevation could not be ruled out. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Sexual-Reproductive Health Belief Model of college students

    Directory of Open Access Journals (Sweden)

    Masoomeh Simbar

    2004-09-01

    Full Text Available Sexual- reproductive health of youth is one of the most unknown aspects of our community, while the world, including our country is faced with the risk of AIDS spreading. The aim of this study was to describe Health Belief Model (HBM of the students about sexual-reproductive health behaviors and evaluate the ability of the model in predicting related behaviors. By using quota sampling, 1117 male and female students of Qazvin Medical Science and International universities were included in the study in 1991. A self-completed questionnaire was prepared containing close questions based on HBM components including perceived threats (susceptibility and severity of related diseases, perceived reproductive benefits and barriers and self efficacy of youth about reproductive health. A total of 645 of participants were female and 457 were male (Mean age 21.4±2.4 and 22.7±3.5, respectively. The Health Belief Model of the students showed that they perceived a moderate threat for AIDS and venereal diseases and their health outcomes. Most of them perceived the benefits of reproductive health behaviors. They believed that the ability of youth in considering reproductive health is low or moderate. However, they noted to some barriers for spreading of reproductive health in youth including inadequacy of services. Boys felt a higher level of threat for acquiring the AIDS and venereal diseases in compare to girls, but girls had a higher knowledge about these diseases and their complications. The Health Belief Model of the students with premarital intercourse behavior was not significantly different with the students without this behavior (Mann-Withney, P<0.05. Female students and the students without the history of premarital intercourse had significantly more positive attitude towards abstinence, comparing to male students and students with the history of premarital intercourse, respectively (Mann-Withney, P<0.05. Seventy five percent of students believed in

  14. Estimation of reproduction number and non stationary spectral analysis of dengue epidemic.

    Science.gov (United States)

    Enduri, Murali Krishna; Jolad, Shivakumar

    2017-06-01

    In this work we analyze the post monsoon Dengue outbreaks by analyzing the transient and long term dynamics of Dengue incidences and its environmental correlates in Ahmedabad city in western India from 2005 to 2012. We calculate the reproduction number R p using the growth rate of post monsoon Dengue outbreaks and biological parameters like host and vector incubation periods and vector mortality rate, and its uncertainties are estimated through Monte-Carlo simulations by sampling parameters from their respective probability distributions. Reduction in Female Aedes mosquito density required for an effective prevention of Dengue outbreaks is also calculated. The non stationary pattern of Dengue incidences and its climatic correlates like rainfall temperature is analyzed through Wavelet based methods. We find that the mean time lag between peak of monsoon and Dengue is 9 weeks. Monsoon and Dengue cases are phase locked from 2008 to 2012 in the 16 to maintain consistency make it "16 to 32" 32 weeks band. The duration of post monsoon outbreak has been increasing every year, especially post 2008, even though the intensity and duration of monsoon has been decreasing. Temperature and Dengue incidences show correlations in the same band, but phase lock is not stationary. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Estimation of Time-Dependent Reproduction Numbers for Porcine Reproductive and Respiratory Syndrome across Different Regions and Production Systems of the US.

    Science.gov (United States)

    Arruda, Andréia G; Alkhamis, Moh A; VanderWaal, Kimberly; Morrison, Robert B; Perez, Andres M

    2017-01-01

    Porcine reproductive and respiratory syndrome (PRRS) is, arguably, the most impactful disease for the North American swine industry, due to its known considerable economic losses. The Swine Health Monitoring Project (SHMP) monitors and reports weekly new PRRS cases in 766 sow herds across the US. The time-dependent reproduction number (TD-R) is a measure of a pathogen's transmissibility. It may serve to capture and report PRRS virus (PRRSV) spread at the regional and system levels. The primary objective of the study here was to estimate the TD-R values for PRRSV using regional and system-level PRRS data, and to contrast it with commonly used metrics of disease, such as incidence estimates and space-time clusters. The second objective was to test whether the estimated TD-Rs were homogenous across four US regions. Retrospective monthly incidence data (2009-2016) were available from the SHMP. The dataset was divided into four regions based on location of participants, and demographic and environmental features, namely, South East (North Carolina), Upper Midwest East (UME, Minnesota/Iowa), Upper Midwest West (Nebraska/South Dakota), and South (Oklahoma panhandle). Generation time distributions were fit to incidence data for each region, and used to calculate the TD-Rs. The Kruskal-Wallis test was used to determine whether the median TD-Rs differed across the four areas. Furthermore, we used a space-time permutation model to assess spatial-temporal patterns for the four regions. Results showed TD-Rs were right skewed with median values close to "1" across all regions, confirming that PRRS has an overall endemic nature. Variation in the TD-R patterns was noted across regions and production systems. Statistically significant periods of PRRSV spread (TD-R > 1) were identified for all regions except UME. A minimum of three space-time clusters were detected for all regions considering the time period examined herein; and their overlap with "spreader events" identified by

  16. Recent female mouse models displaying advanced reproductive aging.

    Science.gov (United States)

    Danilovich, Natalia; Ram Sairam, M

    2006-02-01

    Reproductive senescence occurs in all female mammals with resultant changes in numerous body functional systems and several important features may be species-specific. Those features that appear to parallel human menopause and aging include general similarity of hormone profiles across the menopausal transition, progression to cycle termination through irregular cycles, declining fertility with age, disturbances in thermogenesis, age-related gains in body weight, fat distribution and disposition towards metabolic syndrome. Structural and hormonal changes in the brain and ovary play a critical role in determining the onset of reproductive senescence. The short life span of rodents such as mice (compared to humans) and the ability to generate specific and timed gene deletions, provide powerful experimental paradigms to understand the molecular and functional changes that precede and follow the loss of reproductive capacity. In theory, any manipulation that compromises ovarian function either partly or totally would impact reproductive events at various levels followed by other dysfunctions. In this article, we provide an overview of three mouse models for the study of female reproductive aging. They are derived from different strategies and their age related phenotypes have been characterized to varying degrees. The follitropin receptor knockout (FORKO) mouse, in its null and haploinsufficient state as well as the dioxin/aryl hydrocarbon receptor (AhR) knockout mouse, serve as two examples of single gene deletions. A third model, using administration of a chemical toxicant such as 4-vinylcyclohexene diepoxide (VCD) in the adult state, produces ovarian deficiencies accompanied by aging changes. These will serve as useful alternatives to previously used radical ovariectomy in young adults. It is anticipated that these new models and more that will be forthcoming will extend opportunities to understand reproductive aging and resolve controversies that abound on issues

  17. Estimating the reproductive number, total outbreak size, and reporting rates for Zika epidemics in South and Central America

    Directory of Open Access Journals (Sweden)

    Deborah P. Shutt

    2017-12-01

    Full Text Available As South and Central American countries prepare for increased birth defects from Zika virus outbreaks and plan for mitigation strategies to minimize ongoing and future outbreaks, understanding important characteristics of Zika outbreaks and how they vary across regions is a challenging and important problem. We developed a mathematical model for the 2015/2016 Zika virus outbreak dynamics in Colombia, El Salvador, and Suriname. We fit the model to publicly available data provided by the Pan American Health Organization, using Approximate Bayesian Computation to estimate parameter distributions and provide uncertainty quantification. The model indicated that a country-level analysis was not appropriate for Colombia. We then estimated the basic reproduction number to range between 4 and 6 for El Salvador and Suriname with a median of 4.3 and 5.3, respectively. We estimated the reporting rate to be around 16% in El Salvador and 18% in Suriname with estimated total outbreak sizes of 73,395 and 21,647 people, respectively. The uncertainty in parameter estimates highlights a need for research and data collection that will better constrain parameter ranges.

  18. A three-stage discrete-time population model: continuous versus seasonal reproduction.

    Science.gov (United States)

    Ackleh, Azmy S; Dib, Youssef M; Jang, Sophia R-J

    2007-10-01

    We consider a three-stage discrete-time population model with density-dependent survivorship and time-dependent reproduction. We provide stability analysis for two types of birth mechanisms: continuous and seasonal. We show that when birth is continuous there exists a unique globally stable interior equilibrium provided that the inherent net reproductive number is greater than unity. If it is less than unity, then extinction is the population's fate. We then analyze the case when birth is a function of period two and show that the unique two-cycle is globally attracting when the inherent net reproductive number is greater than unity, while if it is less than unity the population goes to extinction. The two birth types are then compared. It is shown that for low birth rates the adult average number over a one-year period is always higher when reproduction is continuous. Numerical simulations suggest that this remains true for high birth rates. Thus periodic birth rates of period two are deleterious for the three-stage population model. This is different from the results obtained for a two-stage model discussed by Ackleh and Jang (J. Diff. Equ. Appl., 13, 261-274, 2007), where it was shown that for low birth rates seasonal breeding results in higher adult averages.

  19. Stochastic modeling of sunshine number data

    Energy Technology Data Exchange (ETDEWEB)

    Brabec, Marek, E-mail: mbrabec@cs.cas.cz [Department of Nonlinear Modeling, Institute of Computer Science, Academy of Sciences of the Czech Republic, Pod Vodarenskou vezi 2, 182 07 Prague 8 (Czech Republic); Paulescu, Marius [Physics Department, West University of Timisoara, V. Parvan 4, 300223 Timisoara (Romania); Badescu, Viorel [Candida Oancea Institute, Polytechnic University of Bucharest, Spl. Independentei 313, 060042 Bucharest (Romania)

    2013-11-13

    In this paper, we will present a unified statistical modeling framework for estimation and forecasting sunshine number (SSN) data. Sunshine number has been proposed earlier to describe sunshine time series in qualitative terms (Theor Appl Climatol 72 (2002) 127-136) and since then, it was shown to be useful not only for theoretical purposes but also for practical considerations, e.g. those related to the development of photovoltaic energy production. Statistical modeling and prediction of SSN as a binary time series has been challenging problem, however. Our statistical model for SSN time series is based on an underlying stochastic process formulation of Markov chain type. We will show how its transition probabilities can be efficiently estimated within logistic regression framework. In fact, our logistic Markovian model can be relatively easily fitted via maximum likelihood approach. This is optimal in many respects and it also enables us to use formalized statistical inference theory to obtain not only the point estimates of transition probabilities and their functions of interest, but also related uncertainties, as well as to test of various hypotheses of practical interest, etc. It is straightforward to deal with non-homogeneous transition probabilities in this framework. Very importantly from both physical and practical points of view, logistic Markov model class allows us to test hypotheses about how SSN dependents on various external covariates (e.g. elevation angle, solar time, etc.) and about details of the dynamic model (order and functional shape of the Markov kernel, etc.). Therefore, using generalized additive model approach (GAM), we can fit and compare models of various complexity which insist on keeping physical interpretation of the statistical model and its parts. After introducing the Markovian model and general approach for identification of its parameters, we will illustrate its use and performance on high resolution SSN data from the Solar

  20. Stochastic modeling of sunshine number data

    International Nuclear Information System (INIS)

    Brabec, Marek; Paulescu, Marius; Badescu, Viorel

    2013-01-01

    In this paper, we will present a unified statistical modeling framework for estimation and forecasting sunshine number (SSN) data. Sunshine number has been proposed earlier to describe sunshine time series in qualitative terms (Theor Appl Climatol 72 (2002) 127-136) and since then, it was shown to be useful not only for theoretical purposes but also for practical considerations, e.g. those related to the development of photovoltaic energy production. Statistical modeling and prediction of SSN as a binary time series has been challenging problem, however. Our statistical model for SSN time series is based on an underlying stochastic process formulation of Markov chain type. We will show how its transition probabilities can be efficiently estimated within logistic regression framework. In fact, our logistic Markovian model can be relatively easily fitted via maximum likelihood approach. This is optimal in many respects and it also enables us to use formalized statistical inference theory to obtain not only the point estimates of transition probabilities and their functions of interest, but also related uncertainties, as well as to test of various hypotheses of practical interest, etc. It is straightforward to deal with non-homogeneous transition probabilities in this framework. Very importantly from both physical and practical points of view, logistic Markov model class allows us to test hypotheses about how SSN dependents on various external covariates (e.g. elevation angle, solar time, etc.) and about details of the dynamic model (order and functional shape of the Markov kernel, etc.). Therefore, using generalized additive model approach (GAM), we can fit and compare models of various complexity which insist on keeping physical interpretation of the statistical model and its parts. After introducing the Markovian model and general approach for identification of its parameters, we will illustrate its use and performance on high resolution SSN data from the Solar

  1. Nowcasting sunshine number using logistic modeling

    Czech Academy of Sciences Publication Activity Database

    Brabec, Marek; Badescu, V.; Paulescu, M.

    2013-01-01

    Roč. 120, č. 1-2 (2013), s. 61-71 ISSN 0177-7971 R&D Projects: GA MŠk LD12009 Grant - others:European Cooperation in Science and Technology(XE) COST ES1002 Institutional research plan: CEZ:AV0Z1030915 Keywords : logistic regression * Markov model * sunshine number Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 1.245, year: 2013

  2. The US 2009 A(H1N1) influenza epidemic: quantifying the impact of school openings on the reproductive number.

    Science.gov (United States)

    Huang, Karen E; Lipsitch, Marc; Shaman, Jeffrey; Goldstein, Edward

    2014-03-01

    There is limited information on differences in the dynamics of influenza transmission during time periods when schools are open compared with periods when they are closed. Data on school openings, influenza surveillance, and absolute humidity were incorporated into a regression model to estimate the increase in the reproductive number for the 2009 A(H1N1) influenza pandemic associated with the opening of school in 10 US states. The estimate for the average increase in the reproductive number for the 2009 A(H1N1) influenza pandemic associated with the beginning of the school year was 19.5% (95% credible interval = 10%-29%). Whether schools are open or closed can have a major impact on community transmission dynamics of influenza.

  3. Bariatric surgery influences the number and quality of oocytes in patients submitted to assisted reproduction techniques.

    Science.gov (United States)

    Christofolini, Juliana; Bianco, Bianca; Santos, Gustavo; Adami, Fernando; Christofolini, Denise; Barbosa, Caio Parente

    2014-03-01

    To determine differences in follicle stimulation, oocyte retrieval, maturation, and fertilization among patients who underwent bariatric surgery, obese patients, and patients with 18 assisted reproduction techniques and check that these patients may have some impairment in ovarian response. The study comprised three groups: GI: 29 patients who had undergone restrictive and/or malabsorptive bariatric surgery; GII: 57 obese patients (BMI > 30 kg/m²); and GIII: 94 patients (18 reproductive process can be impaired. Bariatric surgery appears to have an important impact on the formation of follicles and oocytes. © 2013 The Obesity Society.

  4. Effects of sex and reproductive experience on the number of orexin A-immunoreactive cells in the prairie vole brain.

    Science.gov (United States)

    Donlin, Michael; Cavanaugh, Breyanna L; Spagnuolo, Olivia S; Yan, Lily; Lonstein, Joseph S

    2014-07-01

    Large populations of cells synthesizing the neuropeptide orexin (OX) exist in the caudal hypothalamus of all species examined and are implicated in physiological and behavioral processes including arousal, stress, anxiety and depression, reproduction, and goal-directed behaviors. Hypothalamic OX expression is sexually dimorphic in different directions in laboratory rats (F>M) and mice (M>F), suggesting different roles in male and female physiology and behavior that are species-specific. We here examined if the number of hypothalamic cells immunoreactive for orexin A (OXA) differs between male and female prairie voles (Microtus ochrogaster), a socially monogamous species that pairbonds after mating and in which both sexes care for offspring, and if reproductive experience influences their number of OXA-immunoreactive (OXA-ir) cells. It was found that the total number of OXA-ir cells did not differ between the sexes, but females had more OXA-ir cells than males in anterior levels of the caudal hypothalamus, while males had more OXA-ir cells posteriorly. Sexually experienced females sacrificed 12 days after the birth of their first litter, or one day after birth of a second litter, had more OXA-ir cells in anterior levels but not posterior levels of the caudal hypothalamus compared to females housed with a brother (incest avoidance prevents sibling mating). Male prairie voles showed no effect of reproductive experience but showed an unexpected effect of cohabitation duration regardless of mating. The sex difference in the distribution of OXA-ir cells, and their increased number in anterior levels of the caudal hypothalamus of reproductively experienced female prairie voles, may reflect a sex-specific mechanism involved in pairbonding, parenting, or lactation in this species. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Use of learning models and media regarding reproductive health attitudes and reproductive system learning outcomes in senior high schools

    Directory of Open Access Journals (Sweden)

    Isoh Sukaesah, Rusdi

    2017-12-01

    Full Text Available Model and learning media is an important component that may affect the achievement of learning objectives. Model selection and appropriate learning media can improve student learning outcomes both in the cognitive and affective domains. This study was aimed to examine the effect of the learning model Think Pair Share (TPS, Student Team Achievement Division (STAD and Conventional learning model and the interaction model and learning media attitude towards reproductive health and student learning outcomes in the material reproductive system. The study was conducted at XI MIA grade students in four Senior High Schools in North Jakarta the academic year 2014/2015. Data were collected through the test instrument scale reproductive health attitudes and learning outcomes instruments reproductive system. Data were analyzed by Two-Way ANOVA and Tukey Test. The results showed that the use of models and instructional media and the interaction between the model and learning media significantly influence the attitude of reproductive health and learning outcomes of the reproductive system of high school students with a significance value (p<  = 0.01.

  6. A size-structured model of bacterial growth and reproduction.

    Science.gov (United States)

    Ellermeyer, S F; Pilyugin, S S

    2012-01-01

    We consider a size-structured bacterial population model in which the rate of cell growth is both size- and time-dependent and the average per capita reproduction rate is specified as a model parameter. It is shown that the model admits classical solutions. The population-level and distribution-level behaviours of these solutions are then determined in terms of the model parameters. The distribution-level behaviour is found to be different from that found in similar models of bacterial population dynamics. Rather than convergence to a stable size distribution, we find that size distributions repeat in cycles. This phenomenon is observed in similar models only under special assumptions on the functional form of the size-dependent growth rate factor. Our main results are illustrated with examples, and we also provide an introductory study of the bacterial growth in a chemostat within the framework of our model.

  7. The A Theory Of Magnitude (ATOM) model in temporal perception and reproduction tasks.

    Science.gov (United States)

    Fabbri, Marco; Cancellieri, Jennifer; Natale, Vincenzo

    2012-01-01

    According to the A Theory of Magnitude (ATOM) model, time, numbers and space are processed by a common analog magnitude system. The model proposes that time, numbers and space are influenced by each other. Indeed, spatial-temporal (STEARC effect), spatial-numerical (SNARC effect) and temporal-numerical (TiNARC effect) interactions have been observed. However, the processing of time, numbers and space has not yet been studied within the same experimental procedure. The goal of this study is to test the ATOM model using a procedure in which time, numbers and space are all present. The participants were asked to perform temporal estimation (Experiment 1) and reproduction (Experiment 2) tasks in two different conditions, with either numbers or letters as stimuli. In Experiment 1, significant STEARC, SNARC and TiNARC effects were found in general and when numbers were presented. Moreover, a significant triple interaction between space, time and magnitude was observed, indicating associations between the left key, short duration and small magnitudes, as well as between the right key, long duration and large magnitudes. These results were similar in reaction times and accuracy. In Experiment 2, the results of reproduction times mirrored the previous data but the triple interaction was not found on reproduction times. Considering the temporal accuracy, the STEARC, SNARC and TiNARC effects as well as triple interaction were found. The results seem to partially confirm the ATOM model, even if differences between temporal tasks should be posited. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Number of conspecifics and reproduction in the invasive plant Eschscholzia californica (Papaveraceae): is there a pollinator-mediated Allee effect?

    Science.gov (United States)

    Anic, V; Henríquez, C A; Abades, S R; Bustamante, R O

    2015-05-01

    The component Allee effect has been defined as 'a positive relationship between any measure of individual fitness and the number or density of conspecifics'. Larger plant populations or large patches have shown a higher pollinator visitation rate, which may give rise to an Allee effect in reproduction of the plants. We experimentally tested the effect of number of conspecifics on reproduction and pollinator visitation in Eschscholzia californica Cham., an invasive plant in Chile. We then built patches with two, eight and 16 flowering individuals of E. californica (11 replicates per treatment) in an area characterised by dominance of the study species. We found that E. californica exhibits a component Allee effect, as the number of individuals of this species has a positive effect on individual seed set. However, individual fruit production was not affected by the number of plants examined. Pollinator visitation rate was also independent of the number of plants, so this factor would not explain the Allee effect. This rate was positively correlated with the total number of flowers in the patches. We also found that the number of plants did not affect the seed mass or proportion of germinated seeds in the patches. Higher pollen availability in patches with 16 plants and pollination by wind could explain the Allee effect. The component Allee effect identified could lead to a weak demographic Allee effect that might reduce the rate of spread of E. californica. Knowledge of this would be useful for management of this invasive plant in Chile. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  9. Leydig cell number and sperm production decrease induced by chronic ametryn exposure: a negative impact on animal reproductive health.

    Science.gov (United States)

    Dantas, T A; Cancian, G; Neodini, D N R; Mano, D R S; Capucho, C; Predes, F S; Pulz, R Barbieri; Pigoso, A A; Dolder, H; Severi-Aguiar, G D C

    2015-06-01

    Ametryn is an herbicide used to control broadleaf and grass weeds and its acute and chronic toxicity is expected to be low. Since toxicological data on ametryn is scarce, the aim of this study was to evaluate rat reproductive toxicity. Thirty-six adult male Wistar rats (90 days) were divided into three groups: Co (control) and T1 and T2 exposed to 15 and 30 mg/kg/day of ametryn, respectively, for 56 days. Testicular analysis demonstrated that ametryn decreased sperm number per testis, daily sperm production, and Leydig cell number in both treated groups, although little perceptible morphological change has been observed in seminiferous tubule structure. Lipid peroxidation was higher in group T2, catalase activity decreased in T1 group, superoxide dismutase activity diminished, and a smaller number of sulphydryl groups of total proteins were verified in both exposed groups, suggesting oxidative stress. These results showed negative ametryn influence on the testes and can compromise animal reproductive performance and survival.

  10. An individual reproduction model sensitive to milk yield and body condition in Holstein dairy cows.

    Science.gov (United States)

    Brun-Lafleur, L; Cutullic, E; Faverdin, P; Delaby, L; Disenhaus, C

    2013-08-01

    To simulate the consequences of management in dairy herds, the use of individual-based herd models is very useful and has become common. Reproduction is a key driver of milk production and herd dynamics, whose influence has been magnified by the decrease in reproductive performance over the last decades. Moreover, feeding management influences milk yield (MY) and body reserves, which in turn influence reproductive performance. Therefore, our objective was to build an up-to-date animal reproduction model sensitive to both MY and body condition score (BCS). A dynamic and stochastic individual reproduction model was built mainly from data of a single recent long-term experiment. This model covers the whole reproductive process and is composed of a succession of discrete stochastic events, mainly calving, ovulations, conception and embryonic loss. Each reproductive step is sensitive to MY or BCS levels or changes. The model takes into account recent evolutions of reproductive performance, particularly concerning calving-to-first ovulation interval, cyclicity (normal cycle length, prevalence of prolonged luteal phase), oestrus expression and pregnancy (conception, early and late embryonic loss). A sensitivity analysis of the model to MY and BCS at calving was performed. The simulated performance was compared with observed data from the database used to build the model and from the bibliography to validate the model. Despite comprising a whole series of reproductive steps, the model made it possible to simulate realistic global reproduction outputs. It was able to well simulate the overall reproductive performance observed in farms in terms of both success rate (recalving rate) and reproduction delays (calving interval). This model has the purpose to be integrated in herd simulation models to usefully test the impact of management strategies on herd reproductive performance, and thus on calving patterns and culling rates.

  11. Modeling reproductive trajectories of roe deer females: fixed or dynamic heterogeneity?

    Science.gov (United States)

    Plard, F; Bonenfant, C; Delormeb, D; Gaillard, J M

    2012-12-01

    The relative role of dynamic and fixed heterogeneity in shaping the individual heterogeneity observed in most life-history traits remains difficult to quantify. In a recent work, Tuljapurkar et al. (2009) suggested modeling individual heterogeneity in lifetime reproductive success by a null model building reproductive trajectories from a first-order Markov chain. According to this model, among-individual differences in reproductive trajectories would be generated by the stochastic transitions among reproductive states (such as breeder and non-breeder) due to dynamic heterogeneity. In this work, we analyze the individual variation in three reproductive metrics (reproductive status, fecundity, and reproductive success) in two populations of roe deer intensively monitored using Tuljapurkar et al. (2009)’s dynamic model. Moreover, we challenge the Tuljapurkar model previously used as a biological null model to test whether the observed distribution of reproductive success over the lifetime was generated by a stochastic process by modifying two steps of the previous model to build a full stochastic model. We show that a distribution generated by the full dynamic model proposed by Tuljapurkar et al. (2009) can be consistently interpreted as only generated from a stochastic biological process provided that the probabilities of transition among reproductive states used are independent of the current reproductive state and that the positive covariation that usually occurs between survival and reproduction among individuals is removed. Only the reproductive status of roe deer females could be restricted to a stochastic process described by the full stochastic model, probably because most females (>90%) were breeders in a given year. The fecundity of roe deer females could not be adequately described by the full dynamic and full stochastic model, and the observed distribution of female reproductive success differed from the one generated by a full dynamic model in which

  12. Estimation of the number of women of reproductive age in need of preventive chemotherapy for soil-transmitted helminth infections.

    Science.gov (United States)

    Mupfasoni, Denise; Mikhailov, Alexei; Mbabazi, Pamela; King, Jonathan; Gyorkos, Theresa W; Montresor, Antonio

    2018-02-01

    Soil-transmitted helminth infections are among the most common infections in developing countries. Globally, as many as 2 billion people are considered to be at risk for soil-transmitted-helminth (STH) infections. Preschool children (PSAC), school-age children (SAC) and women of reproductive age (WRA) are at high risk of STH-attributable morbidity and preventive chemotherapy (PC) for STH is recommended by the World health Organization (WHO). Over the last five years, PC coverage in PSAC and SAC has gradually increased, while coverage in WRA has lagged. Estimating the numbers of WRA in each endemic country would inform scale-up in this group. A two-step process was used: 1) total numbers of girls and women between 15 and 49 years of age were obtained from the United Nations World Population Prospects 2015 database; and 2) the proportion in need of PC was obtained primarily from extrapolation from the WHO PC Databank. WRA were divided into four sub-groups reflecting different reproductive life stages, each having a potentially different interface with the health care system and, consequently, presenting different opportunities for intervention strategies. Worldwide, we estimated that 688 million WRA in 102 countries were in need of PC for STH in 2015. The South-East Asia (49%) and Africa regions (26%) had the highest numbers. Adolescent girls accounted for 16%, while pregnant and lactating women each represented 10%. Over 25 million pregnant women alone were estimated living in areas where the prevalence of hookworm and T. trichiura infection was ≥ 20%. Approximately 20% of at-risk WRA had received deworming with albendazole through the Global Programme to Eliminate Filariasis. To close current gaps in coverage, numbers of WRA in need of PC for STH are essential for operational strategies to control STH infection.

  13. New Resources on Youth Reproductive Health and HIV Prevention, 2002-2004. YouthLens on Reproductive Health and HIV/AIDS. Number 14

    Science.gov (United States)

    Finger, William, Comp.; Tipton, Margaret, Comp.

    2005-01-01

    As a sequel to YouthLens No. 1, New Resources Available on Youth Reproductive Health and HIV Prevention (July 2002), this YouthLens summarizes major reports and resources that have appeared since July 2002. The resources are organized by overview reports, reproductive health resources, and HIV/AIDS resources. [YouthLens is an activity of YouthNet,…

  14. Reproductive capacity of Chrysoperla externa (Hagen) (Neuroptera, Chrysopidae) in function of the number of individuals per unit of rearing

    International Nuclear Information System (INIS)

    Pessoa, Luis Gustavo Amorim; Freitas, Sergio de

    2008-01-01

    Reproductive capacity of Chrysoperla externa (Hagen) (Neuroptera, Chrysopidae) in function of the number of individuals per unit of rearing. This work was carried out to investigate the reproductive potential of Chrysoperla externa subjected to different densities per rearing unit. Adults of the F 4 offspring were kept at 25 ± 1 deg C, RH 70 ± 10% and 12 h photo phase. It was used the following densities per rearing unit (10 cm of diameter by 23 cm of height, and volume of 1650 cm 3 ): 1 male: 3 female, 2 males: 6 females, 3 males: 9 females and 4 males: 12 females. It was evaluated the pre-oviposition period, the daily and total oviposition per female and per rearing unit, the percentage of viable and infertile eggs percentage and the exploitation index per female and per rearing unit. The density 4 males: 12 females presented better exploitation when compared to the other densities thus equalizing the low values obtained for the mean and total egg laying per female. (author)

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

    Science.gov (United States)

    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. © 2014 Society for Reproduction and Fertility.

  16. Optimizing the number of cleavage stage embryos to transfer on day 3 in women 38 years of age and older: a Society for Assisted Reproductive Technology database study.

    Science.gov (United States)

    Stern, Judy E; Goldman, Marlene B; Hatasaka, Harry; MacKenzie, Todd A; Surrey, Eric S; Racowsky, Catherine

    2009-03-01

    To determine the optimal number of day 3 embryos to transfer in women >or=38 years by conducting an evidence-based evaluation. Retrospective analysis of 2000-2004 national SART data. National writing group. A total of 36,103 day 3 embryo transfers in women >or=38 years undergoing their first assisted reproductive technology cycle. None. Logistic regression was used to model the probability of pregnancy, delivery, and multiple births (twin or high order) based on age- and cycle-specific parameters. Pregnancy rates, delivery rates, and multiple rates increased up to transfer of three embryos in 38-year-olds and four in 39-year-olds; beyond this number, only multiple rates increased. In women >or=40 years, delivery rates and multiple rates climbed steadily with increasing numbers transferred. Multivariate analysis confirmed the statistically significant effect of age, number of oocytes retrieved, and embryo cryopreservation on delivery and multiple rates. Maximum FSH level was not an independent predictor by multivariate analysis. Use of intracytoplasmic sperm injection was associated with lowered delivery rate. No more than three or four embryos should be transferred in 38- and 39-year-olds, respectively, whereas up to five embryos could be transferred in >or=40-year-olds. Numbers of embryos to transfer should be adjusted according to number of oocytes retrieved and availability of excess embryos for cryopreservation.

  17. Evaluation of possible toxic effects of spearmint (Mentha spicata) on the reproductive system, fertility and number of offspring in adult male rats.

    Science.gov (United States)

    Nozhat, Fatemeh; Alaee, Sanaz; Behzadi, Khodabakhsh; Azadi Chegini, Najmeh

    2014-11-01

    In this study we investigated the effects of spearmint (Mentha spicata Labiatae) on the reproductive system, fertility and number of offspring in adult male rats. Adult Wistar male rats in one control (C) and three experimental groups (I, II and III) received 0, 10, 20 and 40 mg/kg spearmint extract orally for 45 days, respectively. Following this treatment, the animals' weights, and the standard weight of reproductive tissues, sperm count, sperm motility and serum testosterone concentration were measured, and reproductive tissues were examined histopathologically. To evaluate the effects of spearmint on fertility of male rats and growth of their offspring, male rats of the control and experimental groups mated with untreated female rats. RESULTS showed that spearmint did not affect the rats' body and reproductive tissue weights. The sperm count, fast and slow progressive motility of sperm and serum testosterone concentration decreased while number of non-progressive sperm and immotile sperm increased in the experimental groups compared to the control group, but none of these changes were statistically significant. Histopathological studies showed no severe changes in reproductive tissues between control and experimental groups. Number and growth of offspring born from mating of male rats with untreated female rats showed no difference. We concluded that spearmint has no significant toxic effect on the reproductive system, fertility and number of offspring in adult male rats at the above mentioned dose levels. However high levels of this extract may have adverse effects on male fertility.

  18. A review of Red Queen models for the persistence of obligate sexual reproduction.

    Science.gov (United States)

    Lively, Curtis M

    2010-01-01

    I present a historical review of coevolutionary models for the evolutionary persistence of sexual reproduction. The focus is on the fate of obligately sexual populations facing competition with one or more obligately asexual clones. An early simulation model by Hamilton (Hamilton WD. 1980. Sex versus non-sex versus parasite. Oikos. 35:282-290.) suggested that parasites could be an important force in selecting against asexual clones, leading to the persistence of sex. This result was consistent with a number of independent verbal models generated from 1975-1983. Conversely, the models by May and Anderson (May RM, Anderson RM. 1983. Epidemiology and genetics in the coevolution of parasites and hosts. Proc R Soc Lond B Biol Sci. 219:281-313.), which included more epidemiological detail, suggested that parasites were an unlikely source of selection to favor sexual over asexual reproduction. Thus began an oscillation of opinion regarding the role of parasites in selection for sex. It would seem at present that some of the differences of opinion over time stemmed from the different ways that models were constructed, including whether the sexual population was in competition with a genetically diverse asexual population or a single clonal genotype. On theoretical grounds, parasite-mediated selection for sex seems more likely if the sexual population has options in genotypic space that are not available to the clones. Models that incorporate more ecological realism also seem more favorable to the parasite theory of sex.

  19. Maternal testosterone and reproductive outcome in a rat model of obesity.

    Science.gov (United States)

    Arnon, Liat; Hazut, Noa; Tabachnik, Tzlil; Weller, Aron; Koren, Lee

    2016-09-01

    Global sex differences in obesity rates are persistent, suggesting the involvement of sex steroids. In addition, adipose tissue is a metabolic site for steroidogenesis. Here, we compared female reproductive parameters in a rat model of obesity, with the same parameters in its lean control strain, and tested for an association with integrated measures of corticosterone and testosterone. Steroids were extracted and quantified from 17 Otsuka Long Evans Tokushima Fatty (OLETF; an animal model for obesity) and 13 Long Evans Tokushima Otsuka (LETO; the lean control strain) hair samples that were collected after weaning offspring. The obese OLETF mothers had higher hair testosterone levels than the control LETO strain. Overall, testosterone, but not corticosterone, predicted litter sex ratios. Younger mothers with large litters and older mothers with small litters tended to have the highest sex ratios (i.e., male-biased litters). In the lean LETO strain, but not in the obese OLETF, maternal testosterone was positively associated with litter size and number of male pups. Corticosterone did not differ between the two strains and was not associated with testosterone or with reproductive parameters. This study suggests that long-term circulating testosterone is associated with female reproduction in multiple ways. The possible trade-off between litter size and sex ratio may be mediated by testosterone and influenced by body fat and composition, which influence the individual's well-being. Exploring the multiple roles of testosterone in females may also help explain the complex relationship between obesity and reproduction. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Modelling the effects of environmental and individual variability when measuring the costs of first reproduction

    Directory of Open Access Journals (Sweden)

    Barbraud, C.

    2004-06-01

    Full Text Available How do animals balance their investment in young against their own chances to survive and reproduce in the future? This life–history trade–off, referred to as the cost of reproduction (Williams, 1966, holds a central place in life–history theory (Roff, 1992; Stearns, 1992; McNamara & Houston, 1996. Because individuals can only acquire a limited amount of energy, reproduction and survival as well as current and future reproduction are considered as functions competing for the same resources. In this framework, individuals may optimise life–history decisions. If the reproductive effort in one year leads to a loss in future reproductive output through decreased adult survival or reduced fecundity, then the optimal effort in the current season is less than the effort that would maximize the number of offspring produced in that season (Charnov & Krebs, 1974. There are at least two kinds of factors likely to confound the measurement of the costs of reproduction in the wild. First, there could be differences in the amount of energy individuals acquire and allocate to various functions. This phenotypic heterogeneity can mask or exacerbate individual allocation patterns when trends are averaged across a population (Vaupel & Yashin, 1985; McDonald et al., 1996; Cam & Monnat, 2000. Second, there could be variations in resource availability affecting energy acquisition and allocation. Theoretical models examining the optimal phenotypic balance between reproduction and survival under variable breeding conditions have investigated the influence of environmental stochasticity on the cost of reproduction in birds (Erikstad et al., 1998; Orzack & Tuljapurkar, 2001. However, there is little empirical evidence supporting these theoretical models. Here, we present analysis of the influence of experience, but also of the differential effects of environmental and individual variation on survival and future breeding probability. We address the question of the

  1. Complexities and contingencies conceptualised: towards a model of reproductive navigation

    NARCIS (Netherlands)

    van der Sijpt, E.

    2014-01-01

    Current international attention to reproductive health behaviour is inspired by a western celebration of individual rights, autonomous action and rational choice. A predominant idea is that individuals should be free to act in accordance with their reproductive intentions and that, in doing so, they

  2. Parity-specific and two-sex utility models of reproductive intentions.

    Science.gov (United States)

    Fried, E S; Hofferth, S L; Udry, J R

    1980-02-01

    This paper uses married couples' anticipated consequences of having a (another) child to predict their reproductive intentions. Parity-specific models identify different variables as predictors of reproductive behavior at different parities but do not yield interpretable patterns of difference by parity. Parity-specific models are not significantly stronger predictors of reproductive behavior. Generally, wife-only models are distinctly superior to husband-only models. Two-sex models are usually better predictors than one-sex models but not enough better to justify the additional cost.

  3. Complexities and contingencies conceptualised: towards a model of reproductive navigation.

    Science.gov (United States)

    van der Sijpt, Erica

    2014-02-01

    Current international attention to reproductive health behaviour is inspired by a western celebration of individual rights, autonomous action and rational choice. A predominant idea is that individuals should be free to act in accordance with their reproductive intentions and that, in doing so, they will attain their desired (and quantifiable) fertility outcomes. Yet such a framework leads to a misrepresentation of the reproductive dynamics on the ground, because individual fertility intentions are often not a priori defined, decisions are often not the result of rational calculation and reproductive happenings do not exist in a social vacuum. This article provides sociocultural evidence for a different conceptualisation of reproductive health behaviour. On the basis of long-term anthropological fieldwork in the East Province of Cameroon, I will analyse the complexities of fertility-related decision-making. Two case studies from the field will show that reproductive happenings are often characterised by indeterminacy and contingency. In order to understand the complex ways in which women give direction to these uncertainties, I propose an encompassing framework of reproductive navigation that explicitly acknowledges the influence of sociality and corporeality on fertility aspirations and actions. © 2013 The Author. Sociology of Health & Illness © 2013 Foundation for the Sociology of Health & Illness/John Wiley & Sons Ltd.

  4. Assisted Reproductive Technologies (ART) with Baboons Generate Live Offspring: A Nonhuman Primate Model for ART and Reproductive Sciences

    Science.gov (United States)

    Simerly, Calvin R.; Castro, Carlos A.; Jacoby, Ethan; Grund, Kevin; Turpin, Janet; McFarland, Dave; Champagne, Jamie; Jimenez, Joe B.; Frost, Pat; Bauer, Cassandra; Hewitson, Laura; Schatten, Gerald

    2012-01-01

    Human reproduction has benefited significantly by investigating non-human primate (NHP) models, especially rhesus macaques. To expand the Old World monkey species available for human reproductive studies, we present protocols in baboons, our closest Old World primate relatives, for Assisted Reproductive Technologies (ART) leading to live-born offspring. Baboons complement rhesus by confirming or modifying observations generated in humans often obtained by the study of clinically-discarded specimens donated by anonymous infertility patient-couples. Here, baboon ART protocols, including oocyte collection, in vitro fertilization, intracytoplasmic sperm injection (ICSI), preimplantation development to blastocyst stage and embryo transfer techniques are described. With baboon ART methodologies in place, motility during baboon fertilization was investigated by time-lapse video microscopy. The first ART baboons produced by ICSI, a pair of male twins, were delivered naturally at 165 days post-gestation. Genetic testing of these twins confirmed their ART parental origins and demonstrated that they are unrelated fraternal twins, not identicals. These results have implications for ART outcomes, embryonic stem cell derivation, and reproductive sciences. PMID:20631291

  5. Estimation of additive and dominance variance for reproductive traits from different models in Duroc purebred

    Directory of Open Access Journals (Sweden)

    Talerngsak Angkuraseranee

    2010-05-01

    Full Text Available The additive and dominance genetic variances of 5,801 Duroc reproductive and growth records were estimated usingBULPF90 PC-PACK. Estimates were obtained for number born alive (NBA, birth weight (BW, number weaned (NW, andweaning weight (WW. Data were analyzed using two mixed model equations. The first model included fixed effects andrandom effects identifying inbreeding depression, additive gene effect and permanent environments effects. The secondmodel was similar to the first model, but included the dominance genotypic effect. Heritability estimates of NBA, BW, NWand WW from the two models were 0.1558/0.1716, 0.1616/0.1737, 0.0372/0.0874 and 0.1584/0.1516 respectively. Proportionsof dominance effect to total phenotypic variance from the dominance model were 0.1024, 0.1625, 0.0470, and 0.1536 for NBA,BW, NW and WW respectively. Dominance effects were found to have sizable influence on the litter size traits analyzed.Therefore, genetic evaluation with the dominance model (Model 2 is found more appropriate than the animal model (Model 1.

  6. Modeling number of claims and prediction of total claim amount

    Science.gov (United States)

    Acar, Aslıhan Şentürk; Karabey, Uǧur

    2017-07-01

    In this study we focus on annual number of claims of a private health insurance data set which belongs to a local insurance company in Turkey. In addition to Poisson model and negative binomial model, zero-inflated Poisson model and zero-inflated negative binomial model are used to model the number of claims in order to take into account excess zeros. To investigate the impact of different distributional assumptions for the number of claims on the prediction of total claim amount, predictive performances of candidate models are compared by using root mean square error (RMSE) and mean absolute error (MAE) criteria.

  7. Changing reproductive effort within a semelparous reproductive episode.

    Science.gov (United States)

    Hughes, P William; Simons, Andrew M

    2014-08-01

    • Life-history theory predicts a trade-off between current and future reproduction for iteroparous organisms-as individuals age, the expected value of future reproduction declines, and thus reproductive effort is expected to be higher in later clutches than in earlier. In contrast, models explaining the evolution of semelparity treat semelparous reproduction as instantaneous, with no scope for intraindividual variation. However, semelparous reproduction is also extended, but over shorter time scales; whether there are similar age- or stage-specific changes in reproductive effort within a semelparous episode is unclear. In this study, we assessed whether semelparous individuals increase reproductive effort as residual reproductive value declines by comparing the reproductive phenotype of flowers at five different floral positions along a main inflorescence.• Using the herbaceous monocarp Lobelia inflata, we conducted a longitudinal study of 409 individuals including both laboratory and field populations over three seasons. We recorded six reproductive traits-including the length of three phenological intervals as well as fruit size, seed size, and seed number-for all plants across floral positions produced throughout the reproductive episode.• We found that while the rate of flower initiation did not change, flowers at distal (late) floral positions developed more quickly and contained larger seed than flowers at basal (early) floral positions did.• Our results were consistent with the hypothesis that, like iteroparous organisms, L. inflata increases reproductive effort in response to low residual reproductive value. © 2014 Botanical Society of America, Inc.

  8. Modeling and mapping oak advance reproduction density using soil and site variables

    Science.gov (United States)

    John M. Kabrick; Jason L. Villwock; Daniel C. Dey; Tara L. Keyser; David R. Larsen

    2014-01-01

    Regenerating oaks (Quercus spp.) has remained a widespread and persistent problem throughout their natural range. Research shows that abundant oak advance reproduction is crucial for success. Although it is recognized that oak advance reproduction accumulation is inversely related to site quality, there has been little effort to model oak advance...

  9. QSAR models for reproductive toxicity and endocrine disruption in regulatory use – a preliminary investigation

    DEFF Research Database (Denmark)

    Jensen, Gunde Egeskov; Niemelä, Jay Russell; Wedebye, Eva Bay

    2008-01-01

    the new legislation. This article focuses on a screening exercise by use of our own and commercial QSAR models for identification of possible reproductive toxicants. Three QSAR models were used for reproductive toxicity for the endpoints teratogenic risk to humans (based on animal tests, clinical data...... for humans owing to possible developmental toxic effects: Xn (Harmful) and R63 (Possible risk of harm to the unborn child). The chemicals were also screened in three models for endocrine disruption....

  10. Evaluation of possible toxic effects of spearmint (Mentha spicata on the reproductive system, fertility and number of offspring in adult male rats

    Directory of Open Access Journals (Sweden)

    Fatemeh Nozhat

    2014-11-01

    Full Text Available Objective: In this study we investigated the effects of spearmint (Mentha spicata Labiatae on the reproductive system, fertility and number of offspring in adult male rats. Materials and Methods: Adult Wistar male rats in one control (C and three experimental groups (I, II and III received 0, 10, 20 and 40 mg/kg spearmint extract orally for 45 days, respectively.  Following this treatment, the animals’ weights, and the standard weight of reproductive tissues, sperm count, sperm motility and serum testosterone concentration were measured, and reproductive tissues were examined histopathologically. To evaluate the effects of spearmint on fertility of male rats and growth of their offspring, male rats of the control and experimental groups mated with untreated female rats. Results: Results showed that spearmint did not affect the rats’ body and reproductive tissue weights. The sperm count, fast and slow progressive motility of sperm and serum testosterone concentration decreased while number of non-progressive sperm and immotile sperm increased in the experimental groups compared to the control group, but none of these changes were statistically significant. Histopathological studies showed no severe changes in reproductive tissues between control and experimental groups. Number and growth of offspring born from mating of male rats with untreated female rats showed no difference. Conclusion: We concluded that spearmint has no significant toxic effect on the reproductive system, fertility and number of offspring in adult male rats at the above  mentioned dose levels. However high levels of this extract may have adverse effects on male fertility.

  11. Prediction of cloud droplet number in a general circulation model

    Energy Technology Data Exchange (ETDEWEB)

    Ghan, S.J.; Leung, L.R. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-04-01

    We have applied the Colorado State University Regional Atmospheric Modeling System (RAMS) bulk cloud microphysics parameterization to the treatment of stratiform clouds in the National Center for Atmospheric Research Community Climate Model (CCM2). The RAMS predicts mass concentrations of cloud water, cloud ice, rain and snow, and number concnetration of ice. We have introduced the droplet number conservation equation to predict droplet number and it`s dependence on aerosols.

  12. Dual Numbers Approach in Multiaxis Machines Error Modeling

    Directory of Open Access Journals (Sweden)

    Jaroslav Hrdina

    2014-01-01

    Full Text Available Multiaxis machines error modeling is set in the context of modern differential geometry and linear algebra. We apply special classes of matrices over dual numbers and propose a generalization of such concept by means of general Weil algebras. We show that the classification of the geometric errors follows directly from the algebraic properties of the matrices over dual numbers and thus the calculus over the dual numbers is the proper tool for the methodology of multiaxis machines error modeling.

  13. A general model framework for multisymbol number comparison.

    Science.gov (United States)

    Huber, Stefan; Nuerk, Hans-Christoph; Willmes, Klaus; Moeller, Korbinian

    2016-11-01

    Different models have been proposed for the processing of multisymbol numbers like two- and three-digit numbers but also for negative numbers and decimals. However, these multisymbol numbers are assembled from the same set of Arabic digits and comply with the place-value structure of the Arabic number system. Considering these shared properties, we suggest that the processing of multisymbol numbers can be described in one general model framework. Accordingly, we first developed a computational model framework realizing componential representations of multisymbol numbers and evaluated its validity by simulating standard empirical effects of number magnitude comparison. We observed that the model framework successfully accounted for most of these effects. Moreover, our simulations provided first evidence supporting the notion of a fully componential processing of multisymbol numbers for the specific case of comparing two negative numbers. Thus, our general model framework indicates that the processing of different kinds of multisymbol integer and decimal numbers shares common characteristics (e.g., componential representation). The relevance and applicability of our model goes beyond the case of basic number processing. In particular, we also successfully simulated effects from applied marketing and consumer research by accounting for the left-digit effect found in processing of prices. Finally, we provide evidence that our model framework can be integrated into the more general context of multiattribute decision making. In sum, this indicates that our model framework captures a general scheme of separate processing of different attributes weighted by their saliency for the task at hand. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  14. Using social parasitism to test reproductive skew models in a primitively eusocial wasp.

    Science.gov (United States)

    Green, Jonathan P; Cant, Michael A; Field, Jeremy

    2014-08-22

    Remarkable variation exists in the distribution of reproduction (skew) among members of cooperatively breeding groups, both within and between species. Reproductive skew theory has provided an important framework for understanding this variation. In the primitively eusocial Hymenoptera, two models have been routinely tested: concessions models, which assume complete control of reproduction by a dominant individual, and tug-of-war models, which assume on-going competition among group members over reproduction. Current data provide little support for either model, but uncertainty about the ability of individuals to detect genetic relatedness and difficulties in identifying traits conferring competitive ability mean that the relative importance of concessions versus tug-of-war remains unresolved. Here, we suggest that the use of social parasitism to generate meaningful variation in key social variables represents a valuable opportunity to explore the mechanisms underpinning reproductive skew within the social Hymenoptera. We present a direct test of concessions and tug-of-war models in the paper wasp Polistes dominulus by exploiting pronounced changes in relatedness and power structures that occur following replacement of the dominant by a congeneric social parasite. Comparisons of skew in parasitized and unparasitized colonies are consistent with a tug-of-war over reproduction within P. dominulus groups, but provide no evidence for reproductive concessions.

  15. Pros and cons of estimating the reproduction number from early epidemic growth rate of influenza A (H1N1 2009

    Directory of Open Access Journals (Sweden)

    Chowell Gerardo

    2010-01-01

    Full Text Available Abstract Background In many parts of the world, the exponential growth rate of infections during the initial epidemic phase has been used to make statistical inferences on the reproduction number, R, a summary measure of the transmission potential for the novel influenza A (H1N1 2009. The growth rate at the initial stage of the epidemic in Japan led to estimates for R in the range 2.0 to 2.6, capturing the intensity of the initial outbreak among school-age children in May 2009. Methods An updated estimate of R that takes into account the epidemic data from 29 May to 14 July is provided. An age-structured renewal process is employed to capture the age-dependent transmission dynamics, jointly estimating the reproduction number, the age-dependent susceptibility and the relative contribution of imported cases to secondary transmission. Pitfalls in estimating epidemic growth rates are identified and used for scrutinizing and re-assessing the results of our earlier estimate of R. Results Maximum likelihood estimates of R using the data from 29 May to 14 July ranged from 1.21 to 1.35. The next-generation matrix, based on our age-structured model, predicts that only 17.5% of the population will experience infection by the end of the first pandemic wave. Our earlier estimate of R did not fully capture the population-wide epidemic in quantifying the next-generation matrix from the estimated growth rate during the initial stage of the pandemic in Japan. Conclusions In order to quantify R from the growth rate of cases, it is essential that the selected model captures the underlying transmission dynamics embedded in the data. Exploring additional epidemiological information will be useful for assessing the temporal dynamics. Although the simple concept of R is more easily grasped by the general public than that of the next-generation matrix, the matrix incorporating detailed information (e.g., age-specificity is essential for reducing the levels of

  16. Simulating the Reproductive Behavior of a Region’s Population with an Agent-Based Model

    Directory of Open Access Journals (Sweden)

    Valeriy Leonidovich Makarov

    2015-09-01

    Full Text Available The research analyses the impact of the inequality of demographic transition on socio-demographic characteristics of the regional population and on the dynamics of these characteristics. The study was conducted with the help of computer-based experiments (simulations, which was run on the original agent-based model. The model is an artificial society, and personal characteristics of its members are set so that they could represent age-demographic structure of a simulate region. The agents are divided into two subgroups, which differ in their reproductive strategy. The first group has traditional strategy with high birth rate. The second group has considerably lower birth rate, observed in the modern developed societies. The model uses stochastic approaches to imitate the principle processes of population growth: mortality and morbidity. Mortality is set according to age-sex specific mortality coefficients, which do not differ across the population as a whole. New agents (child births appear as a choice of agents – women of reproductive age, and the choice depends on the subgroup. The overall age and social structure of the region is aggregated across individual agents. A number of experiments has been carried out with the model utilization. This allowed forecasting the size and structure of the population of a given region. The results of the experiments have revealed that despite its simplicity, the developed agent-based model well predicts the initial conditions in the region (e.g. age-demographic and social structure. The model shows good fit in terms of estimating the dynamics of major characteristics of the population.

  17. ON MODELING METHODS OF REPRODUCTION OF FIXED ASSETS IN DYNAMIC INPUT - OUTPUT MODELS

    Directory of Open Access Journals (Sweden)

    Baranov A. O.

    2014-12-01

    Full Text Available The article presents a comparative study of methods for modeling reproduction of fixed assets in various types of dynamic input-output models, which have been developed at the Novosibirsk State University and at the Institute of Economics and Industrial Engineering of the Siberian Division of Russian Academy of Sciences. The study compares the technique of information providing for the investment blocks of the models. Considered in detail mathematical description of the block of fixed assets reproduction in the Dynamic Input - Output Model included in the KAMIN system and the optimization interregional input - output model. Analyzes the peculiarities of information support of investment and fixed assets blocks of the Dynamic Input - Output Model included in the KAMIN system and the optimization interregional input - output model. In conclusion of the article provides suggestions for joint use of the analyzed models for Russian economy development forecasting. Provided the use of the KAMIN system’s models for short-term and middle-term forecasting and the optimization interregional input - output model to develop long-term forecasts based on the spatial structure of the economy.

  18. Species distribution models as a tool to estimate reproductive parameters: a case study with a passerine bird species.

    Science.gov (United States)

    Brambilla, Mattia; Ficetola, Gentile F

    2012-07-01

    1. Correlative species distribution models (SDMs) assess relationships between species distribution data and environmental features, to evaluate the environmental suitability (ES) of a given area for a species, by providing a measure of the probability of presence. If the output of SDMs represents the relationships between habitat features and species performance well, SDM results can be related also to other key parameters of populations, including reproductive parameters. To test this hypothesis, we evaluated whether SDM results can be used as a proxy of reproductive parameters (breeding output, territory size) in red-backed shrikes (Lanius collurio). 2. The distribution of 726 shrike territories in Northern Italy was obtained through multiple focused surveys; for a subset of pairs, we also measured territory area and number of fledged juveniles. We used Maximum Entropy modelling to build a SDM on the basis of territory distribution. We used generalized least squares and spatial generalized mixed models to relate territory size and number of fledged juveniles to SDM suitability, while controlling for spatial autocorrelation. 3. Species distribution models predicted shrike distribution very well. Territory size was negatively related to suitability estimated through SDM, while the number of fledglings significantly increased with the suitability of the territory. This was true also when SDM was built using only spatially and temporally independent data. 4. Results show a clear relationship between ES estimated through presence-only SDMs and two key parameters related to species' reproduction, suggesting that suitability estimated by SDM, and habitat quality determining reproduction parameters in our model system, are correlated. Our study shows the potential use of SDMs to infer important fitness parameters; this information can have great importance in management and conservation. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological

  19. Reproductive rights approach to reproductive health in developing countries.

    Science.gov (United States)

    Pillai, Vijayan K; Gupta, Rashmi

    2011-01-01

    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. 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. 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. 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.

  20. Complexities and contingencies conceptualized: towards a model of reproductive navigation

    NARCIS (Netherlands)

    van der Sijpt, E.; Cohn, S.

    2014-01-01

    This chapter provides sociocultural evidence for a different conceptualization of reproductive health behaviour. On the basis of long-term anthropological fieldwork in the East Province of Cameroon the author analyses of the social complexities and contingencies of local fertility-related decisions

  1. Lepton number violation in theories with a large number of standard model copies

    International Nuclear Information System (INIS)

    Kovalenko, Sergey; Schmidt, Ivan; Paes, Heinrich

    2011-01-01

    We examine lepton number violation (LNV) in theories with a saturated black hole bound on a large number of species. Such theories have been advocated recently as a possible solution to the hierarchy problem and an explanation of the smallness of neutrino masses. On the other hand, the violation of the lepton number can be a potential phenomenological problem of this N-copy extension of the standard model as due to the low quantum gravity scale black holes may induce TeV scale LNV operators generating unacceptably large rates of LNV processes. We show, however, that this issue can be avoided by introducing a spontaneously broken U 1(B-L) . Then, due to the existence of a specific compensation mechanism between contributions of different Majorana neutrino states, LNV processes in the standard model copy become extremely suppressed with rates far beyond experimental reach.

  2. A stochastic model for the simulation of management decisions in dairy herds, with special reference to production, reproduction, culling and income

    NARCIS (Netherlands)

    Dijkhuizen, A.A.; Stelwagen, J.; Renkema, J.A.

    1986-01-01

    A stochastic simulation model was developed to study management decisions in dairy herds. The primary purpose of this model is to quantify the economic effects of different culling policies with respect to productive and reproductive failure. Each stimulated herd consists of a fixed number of up

  3. The Influence of Investor Number on a Microscopic Market Model

    Science.gov (United States)

    Hellthaler, T.

    The stock market model of Levy, Persky, Solomon is simulated for much larger numbers of investors. While small markets can lead to realistically looking prices, the resulting prices of large markets oscillate smoothly in a semi-regular fashion.

  4. Using the basic reproduction number to assess the effects of climate change in the risk of Chagas disease transmission in Colombia.

    Science.gov (United States)

    Cordovez, Juan M; Rendon, Lina Maria; Gonzalez, Camila; Guhl, Felipe

    2014-01-01

    The dynamics of vector-borne diseases has often been linked to climate change. However the commonly complex dynamics of vector-borne diseases make it very difficult to predict risk based on vector or host distributions. The basic reproduction number (R0) integrates all factors that determine whether a pathogen can establish or not. To obtain R0 for complex vector-borne diseases one can use the next-generation matrix (NGM) approach. We used the NGM to compute R0 for Chagas disease in Colombia incorporating the effect of temperature in some of the transmission routes of Trypanosoma cruzi. We used R0 to generate a risk map of present conditions and a forecast risk map at 20 years from now based on mean annual temperature (data obtained from Worldclim). In addition we used the model to compute elasticity and sensitivity indexes on all model parameters and routes of transmission. We present this work as an approach to indicate which transmission pathways are more critical for disease transmission but acknowledge the fact that results and projections strongly depend on better knowledge of entomological parameters and transmission routes. We concluded that the highest contribution to R0 comes from transmission of the parasites from humans to vectors, which is a surprising result. In addition,parameters related to contacts between human and vectors and the efficiency of parasite transmission between them also show a prominent effect on R0.

  5. Uncertainty and sensitivity analysis of the basic reproduction number of diphtheria: a case study of a Rohingya refugee camp in Bangladesh, November–December 2017

    Directory of Open Access Journals (Sweden)

    Ryota Matsuyama

    2018-04-01

    Full Text Available Background A Rohingya refugee camp in Cox’s Bazar, Bangladesh experienced a large-scale diphtheria epidemic in 2017. The background information of previously immune fraction among refugees cannot be explicitly estimated, and thus we conducted an uncertainty analysis of the basic reproduction number, R0. Methods A renewal process model was devised to estimate the R0 and ascertainment rate of cases, and loss of susceptible individuals was modeled as one minus the sum of initially immune fraction and the fraction naturally infected during the epidemic. To account for the uncertainty of initially immune fraction, we employed a Latin Hypercube sampling (LHS method. Results R0 ranged from 4.7 to 14.8 with the median estimate at 7.2. R0 was positively correlated with ascertainment rates. Sensitivity analysis indicated that R0 would become smaller with greater variance of the generation time. Discussion Estimated R0 was broadly consistent with published estimate from endemic data, indicating that the vaccination coverage of 86% has to be satisfied to prevent the epidemic by means of mass vaccination. LHS was particularly useful in the setting of a refugee camp in which the background health status is poorly quantified.

  6. Modelling the dispersion of particle numbers in five European cities

    NARCIS (Netherlands)

    Kukkonen, J.; Karl, M.; Keuken, M.P.; Denier van der Gon, H.A.C.; Denby, B.R.; Singh, V.; Douros, J.; Manders, A.M.M.; Samaras, Z.; Moussiopoulos, N.; Jonkers, S.; Aarnio, M.; Karppinen, A.; Kangas, L.; Lutzenkirchen, S.; Petaja, T.; Vouitsis, I.; Sokhi, R.S.

    2016-01-01

    We present an overview of the modelling of particle number concentrations (PNCs) in five major European cities, namely Helsinki, Oslo, London, Rotterdam and Athens in 2008. Novel emission inventories of particle numbers have been compiled both on urban and European scales. We used atmospheric

  7. Mayer–Jensen Shell Model and Magic Numbers

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 12. Mayer-Jensen Shell Model and Magic Numbers - An Independent Nucleon Model with Spin-Orbit Coupling. R Velusamy. General Article Volume 12 Issue 12 December 2007 pp 12-24 ...

  8. Optimal Number of States in Hidden Markov Models and its ...

    African Journals Online (AJOL)

    In this paper, Hidden Markov Model is applied to model human movements as to facilitate an automatic detection of the same. A number of activities were simulated with the help of two persons. The four movements considered are walking, sitting down-getting up, fall while walking and fall while standing. The data is ...

  9. On the vacuum baryon number in the chiral bag model

    International Nuclear Information System (INIS)

    Jaroszewicz, T.

    1984-01-01

    We give a rederivation, generalization and interpretation of the result of Goldstone and Jaffe on the vacuum baryon number in the chiral bag model. Our results are based on considering the bag model as a theory of free quarks, massless inside and infinitely massive outside the bag. (orig.)

  10. The number of antral follicles in normal women with proven fertility is the best reflection of reproductive age.

    NARCIS (Netherlands)

    Scheffer, G.J.; Broekmans, F.J.; Looman, C.W.; Blankenstein, M.A.; Fauser, B.C.J.M.; Jong, F.H. de; Velde, E.R. te

    2003-01-01

    BACKGROUND: The purpose of this study was to compare the predictive capacity of several markers of reproductive age in normal women. METHODS: Healthy female volunteers (n = 162) aged 25-46 years with proven, normal fertility and regular menstrual cycles were recruited. In this selected group,

  11. Cost of reproduction in the Queensland fruit fly: Y-model versus lethal protein hypothesis

    OpenAIRE

    Fanson, Benjamin G.; Fanson, Kerry V.; Taylor, Phillip W.

    2012-01-01

    The trade-off between lifespan and reproduction is commonly explained by differential allocation of limited resources. Recent research has shown that the ratio of protein to carbohydrate (P : C) of a fly's diet mediates the lifespan–reproduction trade-off, with higher P : C diets increasing egg production but decreasing lifespan. To test whether this P : C effect is because of changing allocation strategies (Y-model hypothesis) or detrimental effects of protein ingestion on lifespan (lethal p...

  12. Early Estimation of the Reproduction Number in the Presence of Imported Cases: Pandemic Influenza H1N1-2009 in New Zealand

    Science.gov (United States)

    Roberts, Michael George; Nishiura, Hiroshi

    2011-01-01

    We analyse data from the early epidemic of H1N1-2009 in New Zealand, and estimate the reproduction number . We employ a renewal process which accounts for imported cases, illustrate some technical pitfalls, and propose a novel estimation method to address these pitfalls. Explicitly accounting for the infection-age distribution of imported cases and for the delay in transmission dynamics due to international travel, was estimated to be (95% confidence interval: ). Hence we show that a previous study, which did not account for these factors, overestimated . Our approach also permitted us to examine the infection-age at which secondary transmission occurs as a function of calendar time, demonstrating the downward bias during the beginning of the epidemic. These technical issues may compromise the usefulness of a well-known estimator of - the inverse of the moment-generating function of the generation time given the intrinsic growth rate. Explicit modelling of the infection-age distribution among imported cases and the examination of the time dependency of the generation time play key roles in avoiding a biased estimate of , especially when one only has data covering a short time interval during the early growth phase of the epidemic. PMID:21637342

  13. Conserved number fluctuations in a hadron resonance gas model

    International Nuclear Information System (INIS)

    Garg, P.; Mishra, D.K.; Netrakanti, P.K.; Mohanty, B.; Mohanty, A.K.; Singh, B.K.; Xu, N.

    2013-01-01

    Net-baryon, net-charge and net-strangeness number fluctuations in high energy heavy-ion collisions are discussed within the framework of a hadron resonance gas (HRG) model. Ratios of the conserved number susceptibilities calculated in HRG are being compared to the corresponding experimental measurements to extract information about the freeze-out condition and the phase structure of systems with strong interactions. We emphasize the importance of considering the actual experimental acceptances in terms of kinematics (pseudorapidity (η) and transverse momentum (p T )), the detected charge state, effect of collective motion of particles in the system and the resonance decay contributions before comparisons are made to the theoretical calculations. In this work, based on HRG model, we report that the net-baryon number fluctuations are least affected by experimental acceptances compared to the net-charge and net-strangeness number fluctuations

  14. Electroweak phase transition in a model with gauged lepton number

    International Nuclear Information System (INIS)

    Aranda, Alfredo; Jiménez, Enrique; Vaquera-Araujo, Carlos A.

    2015-01-01

    In this work we study the electroweak phase transition in a model with gauged lepton number. Here, a family of vector-like leptons is required in order to cancel the gauge anomalies. Furthermore, these leptons can play an important role in the transition process. We find that this framework is able to provide a strong transition, but only for a very limited number of cases.

  15. Nervous control of reproduction in Octopus vulgaris: a new model.

    Science.gov (United States)

    Di Cristo, Carlo

    2013-06-01

    The classic study of Wells and Wells on the control of reproduction in Octopus demonstrated that the activity of the subpedunculate lobe of the brain and environmental illumination both inhibit the release of an unknown gonadotropin from the optic gland. This inhibitory control may be exerted by the neuropeptide Phe-Met-Arg-Phe-NH₂ (FMRFamide). It was later demonstrated that the olfactory lobe is also likely to be involved in the control of optic gland activity. The presence of gonadotropin-releasing hormone in the olfactory lobe suggested that it might exert an excitatory action on optic gland activity. Other neuropeptides have now been localised in the olfactory lobe: neuropeptide Y, galanin, corticotropin-releasing factor, Ala-Pro-Gly-Trp-NH₂ (APGWamide), as well as steroidogenic enzymes and an oestrogen receptor orthologue. This supports the hypothesis that this lobe may also play a part in the control of reproduction in Octopus. The olfactory lobe receives distant chemical stimuli and also appears to be an integrative centre containing a variety of neuropeptides involved in controlling the onset of sexual maturation of Octopus, via the optic gland hormone. This review attempts to summarise current knowledge about the role of the olfactory lobe and optic gland in the control of sexual maturation in Octopus, in the light of new findings and in the context of molluscan comparative physiology.

  16. Modeling the number of car theft using Poisson regression

    Science.gov (United States)

    Zulkifli, Malina; Ling, Agnes Beh Yen; Kasim, Maznah Mat; Ismail, Noriszura

    2016-10-01

    Regression analysis is the most popular statistical methods used to express the relationship between the variables of response with the covariates. The aim of this paper is to evaluate the factors that influence the number of car theft using Poisson regression model. This paper will focus on the number of car thefts that occurred in districts in Peninsular Malaysia. There are two groups of factor that have been considered, namely district descriptive factors and socio and demographic factors. The result of the study showed that Bumiputera composition, Chinese composition, Other ethnic composition, foreign migration, number of residence with the age between 25 to 64, number of employed person and number of unemployed person are the most influence factors that affect the car theft cases. These information are very useful for the law enforcement department, insurance company and car owners in order to reduce and limiting the car theft cases in Peninsular Malaysia.

  17. Overfitting Bayesian Mixture Models with an Unknown Number of Components.

    Directory of Open Access Journals (Sweden)

    Zoé van Havre

    Full Text Available This paper proposes solutions to three issues pertaining to the estimation of finite mixture models with an unknown number of components: the non-identifiability induced by overfitting the number of components, the mixing limitations of standard Markov Chain Monte Carlo (MCMC sampling techniques, and the related label switching problem. An overfitting approach is used to estimate the number of components in a finite mixture model via a Zmix algorithm. Zmix provides a bridge between multidimensional samplers and test based estimation methods, whereby priors are chosen to encourage extra groups to have weights approaching zero. MCMC sampling is made possible by the implementation of prior parallel tempering, an extension of parallel tempering. Zmix can accurately estimate the number of components, posterior parameter estimates and allocation probabilities given a sufficiently large sample size. The results will reflect uncertainty in the final model and will report the range of possible candidate models and their respective estimated probabilities from a single run. Label switching is resolved with a computationally light-weight method, Zswitch, developed for overfitted mixtures by exploiting the intuitiveness of allocation-based relabelling algorithms and the precision of label-invariant loss functions. Four simulation studies are included to illustrate Zmix and Zswitch, as well as three case studies from the literature. All methods are available as part of the R package Zmix, which can currently be applied to univariate Gaussian mixture models.

  18. Overfitting Bayesian Mixture Models with an Unknown Number of Components.

    Science.gov (United States)

    van Havre, Zoé; White, Nicole; Rousseau, Judith; Mengersen, Kerrie

    2015-01-01

    This paper proposes solutions to three issues pertaining to the estimation of finite mixture models with an unknown number of components: the non-identifiability induced by overfitting the number of components, the mixing limitations of standard Markov Chain Monte Carlo (MCMC) sampling techniques, and the related label switching problem. An overfitting approach is used to estimate the number of components in a finite mixture model via a Zmix algorithm. Zmix provides a bridge between multidimensional samplers and test based estimation methods, whereby priors are chosen to encourage extra groups to have weights approaching zero. MCMC sampling is made possible by the implementation of prior parallel tempering, an extension of parallel tempering. Zmix can accurately estimate the number of components, posterior parameter estimates and allocation probabilities given a sufficiently large sample size. The results will reflect uncertainty in the final model and will report the range of possible candidate models and their respective estimated probabilities from a single run. Label switching is resolved with a computationally light-weight method, Zswitch, developed for overfitted mixtures by exploiting the intuitiveness of allocation-based relabelling algorithms and the precision of label-invariant loss functions. Four simulation studies are included to illustrate Zmix and Zswitch, as well as three case studies from the literature. All methods are available as part of the R package Zmix, which can currently be applied to univariate Gaussian mixture models.

  19. Reproduction of an animal model of landmine blast injuries

    Directory of Open Access Journals (Sweden)

    Sen ZHANG

    2014-03-01

    Full Text Available Objective To reproduce an animal model of landmine blast injuries for studying its mechanism and characteristics. Methods Fifteen healthy New Zealand white rabbits (body weight 1.9-2.4 kg were prepared as experimental animals. Punctiform burster was used to simulate the landmine, and it was electrically detonated far away to produce landmine blast injuries on unilateral hind limb of rabbits in upright state. The vital signs before and 5min, 15min, 30min, 45min, 1h, 2h, 3h, 6h, 9h and 12h after injuries were recorded. Autopsy of dead animals was performed immediately and the survivors were sacrificed for pathological examination 6h and 12h after the injury. Macroscopic and microscopic changes in the injured limb and distant organs were observed. Fifteen random adult body weights were generated by random number table, and the explosive energy of M14 landmine (about 29g TNT explosive energy was simulated, to compare the ratio of explosive force equivalent to weight calculated between experimental animals and randomly selected adults. Results No significant change in blood pressure was observed at different time points before and after injuries. A broom-like change was found in the injured limb by the general observation. The subareas and pathological changes of injured limb coincided with the typical limb injuries produced by landmine explosion. Damage in different degrees was found in distant organs, and the wound characteristics and injury of major organs were in accordance with the reports of relevant literature. The ratio of explosive equivalent to weight of experimental animals (0.50±0.04g TNT/kg was similar to that of randomly selected adults (0.51±0.05g TNT/kg. Conclusion The present animal model could simulate the landmine explosive injuries, and may be used in research of landmine explosive injuries. DOI: 10.11855/j.issn.0577-7402.2014.01.14

  20. Sons conceived by assisted reproduction techniques inherit deletions in the azoospermia factor (AZF) region of the Y chromosome and the DAZ gene copy number

    DEFF Research Database (Denmark)

    Mau Kai, C; Juul, A; McElreavey, K

    2008-01-01

    number, supplemented with haplogroup typing in deleted patients, were performed, in combination with clinical assessments in 264 fathers and their sons conceived by assisted reproduction techniques (ART), and in 168 fertile men with normal sperm concentration. RESULTS: In the ART fathers group...... symptoms in early childhood. In the fathers, there was no significant correlation between the DAZ copy number and the severity of spermatogenic failure. CONCLUSIONS: AZFc rearrangements/polymorphisms are transmitted to sons and may represent a risk factor for decreased testis function and male subfertility...

  1. Peer group as a model for the development learning reproductive health in the traditional boarding school

    Directory of Open Access Journals (Sweden)

    awatiful azza

    2016-04-01

    Full Text Available Introduction: Teen problems are conditions that need to be considered in national development in Indonesia. Teenagers problems occur, because they are not prepared regarding knowledge of aspects related to the problem of transition from childhood to adulthood. One of the problems faced by teenagers today is about the health of adolescents, especially related to reproductive health. Methods: This study uses a quantitative approach pre experiment with pre - post test design, the purpose of research, construction of models of healthy reproductive learning through peer groups in traditional schools and analyze the application of learning through peer group against knowledge female students  about reproductive health. The sample was female students in Boarding school Miftahul Hasan Gunung Sepikul amounted to 50 female students, with purposive sampling technique. Results of analysis using Spearman's rho test ,P value of 0.00 obtained value where the value is < less than 0.05 so it can be concluded that there is a learning effect of reproductive health through peer groups for knowledge  female students . Discuss: Boarding schools need to provide curriculum on reproductive health in order to improve the understanding of female students in healthy living behavior associated with reproductive organs.

  2. Beyond R 0: Demographic Models for Variability of Lifetime Reproductive Output

    Science.gov (United States)

    Caswell, Hal

    2011-01-01

    The net reproductive rate measures the expected lifetime reproductive output of an individual, and plays an important role in demography, ecology, evolution, and epidemiology. Well-established methods exist to calculate it from age- or stage-classified demographic data. As an expectation, provides no information on variability; empirical measurements of lifetime reproduction universally show high levels of variability, and often positive skewness among individuals. This is often interpreted as evidence of heterogeneity, and thus of an opportunity for natural selection. However, variability provides evidence of heterogeneity only if it exceeds the level of variability to be expected in a cohort of identical individuals all experiencing the same vital rates. Such comparisons require a way to calculate the statistics of lifetime reproduction from demographic data. Here, a new approach is presented, using the theory of Markov chains with rewards, obtaining all the moments of the distribution of lifetime reproduction. The approach applies to age- or stage-classified models, to constant, periodic, or stochastic environments, and to any kind of reproductive schedule. As examples, I analyze data from six empirical studies, of a variety of animal and plant taxa (nematodes, polychaetes, humans, and several species of perennial plants). PMID:21738586

  3. Application of Z-Number Based Modeling in Psychological Research

    Directory of Open Access Journals (Sweden)

    Rafik Aliev

    2015-01-01

    Full Text Available Pilates exercises have been shown beneficial impact on physical, physiological, and mental characteristics of human beings. In this paper, Z-number based fuzzy approach is applied for modeling the effect of Pilates exercises on motivation, attention, anxiety, and educational achievement. The measuring of psychological parameters is performed using internationally recognized instruments: Academic Motivation Scale (AMS, Test of Attention (D2 Test, and Spielberger’s Anxiety Test completed by students. The GPA of students was used as the measure of educational achievement. Application of Z-information modeling allows us to increase precision and reliability of data processing results in the presence of uncertainty of input data created from completed questionnaires. The basic steps of Z-number based modeling with numerical solutions are presented.

  4. Application of Z-Number Based Modeling in Psychological Research.

    Science.gov (United States)

    Aliev, Rafik; Memmedova, Konul

    2015-01-01

    Pilates exercises have been shown beneficial impact on physical, physiological, and mental characteristics of human beings. In this paper, Z-number based fuzzy approach is applied for modeling the effect of Pilates exercises on motivation, attention, anxiety, and educational achievement. The measuring of psychological parameters is performed using internationally recognized instruments: Academic Motivation Scale (AMS), Test of Attention (D2 Test), and Spielberger's Anxiety Test completed by students. The GPA of students was used as the measure of educational achievement. Application of Z-information modeling allows us to increase precision and reliability of data processing results in the presence of uncertainty of input data created from completed questionnaires. The basic steps of Z-number based modeling with numerical solutions are presented.

  5. Cost of reproduction in the Queensland fruit fly: Y-model versus lethal protein hypothesis.

    Science.gov (United States)

    Fanson, Benjamin G; Fanson, Kerry V; Taylor, Phillip W

    2012-12-22

    The trade-off between lifespan and reproduction is commonly explained by differential allocation of limited resources. Recent research has shown that the ratio of protein to carbohydrate (P : C) of a fly's diet mediates the lifespan-reproduction trade-off, with higher P : C diets increasing egg production but decreasing lifespan. To test whether this P : C effect is because of changing allocation strategies (Y-model hypothesis) or detrimental effects of protein ingestion on lifespan (lethal protein hypothesis), we measured lifespan and egg production in Queensland fruit flies varying in reproductive status (mated, virgin and sterilized females, virgin males) that were fed one of 18 diets varying in protein and carbohydrate amounts. The Y-model predicts that for sterilized females and for males, which require little protein for reproduction, there will be no effect of P : C ratio on lifespan; the lethal protein hypothesis predicts that the effect of P : C ratio should be similar in all groups. In support of the lethal protein hypothesis, and counter to the Y-model, the P : C ratio of the ingested diets had similar effects for all groups. We conclude that the trade-off between lifespan and reproduction is mediated by the detrimental side-effects of protein ingestion on lifespan.

  6. Effective number of breeders provides a link between interannual variation in stream flow and individual reproductive contribution in a stream salmonid.

    Science.gov (United States)

    Whiteley, Andrew R; Coombs, Jason A; Cembrola, Matthew; O'Donnell, Matthew J; Hudy, Mark; Nislow, Keith H; Letcher, Benjamin H

    2015-07-01

    The effective number of breeders that give rise to a cohort (N(b)) is a promising metric for genetic monitoring of species with overlapping generations; however, more work is needed to understand factors that contribute to variation in this measure in natural populations. We tested hypotheses related to interannual variation in N(b) in two long-term studies of brook trout populations. We found no supporting evidence for our initial hypothesis that N^(b) reflects N^(c) (defined as the number of adults in a population at the time of reproduction). N^(b) was stable relative to N^(C) and did not follow trends in abundance (one stream negative, the other positive). We used stream flow estimates to test the alternative hypothesis that environmental factors constrain N(b). We observed an intermediate optimum autumn stream flow for both N^(b) (R(2) = 0.73, P = 0.02) and full-sibling family evenness (R(2) = 0.77, P = 0.01) in one population and a negative correlation between autumn stream flow and full-sib family evenness in the other population (r = -0.95, P = 0.02). Evidence for greater reproductive skew at the lowest and highest autumn flow was consistent with suboptimal conditions at flow extremes. A series of additional tests provided no supporting evidence for a related hypothesis that density-dependent reproductive success was responsible for the lack of relationship between N(b) and N(C) (so-called genetic compensation). This work provides evidence that N(b) is a useful metric of population-specific individual reproductive contribution for genetic monitoring across populations and the link we provide between stream flow and N(b) could be used to help predict population resilience to environmental change. © 2015 John Wiley & Sons Ltd.

  7. Factors contributing to the accumulation of reproductive isolation: A mixed model approach.

    Science.gov (United States)

    Castillo, Dean M

    2017-08-01

    The analysis of large datasets describing reproductive isolation between species has been extremely influential in the study of speciation. However, the statistical methods currently used for these data limit the ability to make direct inferences about the factors predicting the evolution of reproductive isolation. As a result, our understanding of iconic patterns and rules of speciation rely on indirect analyses that have clear statistical limitations. Phylogenetic mixed models are commonly used in ecology and evolution, but have not been applied to studies of reproductive isolation. Here I describe a flexible framework using phylogenetic mixed models to analyze data collected at different evolutionary scales, to test both categorical and continuous predictor variables, and to test the effect of multiple predictors on rates and patterns of reproductive isolation simultaneously. I demonstrate the utility of this framework by re-analyzing four classic datasets, from both animals and plants, and evaluating several hypotheses that could not be tested in the original studies: In the Drosophila and Bufonidae datasets, I found support for more rapid accumulation of reproductive isolation in sympatric species pairs compared to allopatric species pairs. Using Silene and Nolana , I found no evidence supporting the hypothesis that floral differentiation elevates postzygotic reproductive isolation. The faster accumulation of postzygotic isolation in sympatry is likely the result of species coexistence determined by the level of postzygotic isolation between species. In addition, floral trait divergence does not appear to translate into pleiotropic effects on postzygotic reproductive isolation. Overall, these methods can allow researchers to test new hypotheses using a single statistical method, while remedying the statistical limitations of several previous methods.

  8. Mean photon number dependent variational method to the Rabi model

    International Nuclear Information System (INIS)

    Liu, Maoxin; Ying, Zu-Jian; Luo, Hong-Gang; An, Jun-Hong

    2015-01-01

    We present a mean photon number dependent variational method, which works well in the whole coupling regime if the photon energy is dominant over the spin-flipping, to evaluate the properties of the Rabi model for both the ground state and excited states. For the ground state, it is shown that the previous approximate methods, the generalized rotating-wave approximation (only working well in the strong coupling limit) and the generalized variational method (only working well in the weak coupling limit), can be recovered in the corresponding coupling limits. The key point of our method is to tailor the merits of these two existing methods by introducing a mean photon number dependent variational parameter. For the excited states, our method yields considerable improvements over the generalized rotating-wave approximation. The variational method proposed could be readily applied to more complex models, for which it is difficult to formulate an analytic formula. (paper)

  9. Characterizing and modelling persistence in the number of lottery winners

    Science.gov (United States)

    Antonio, Fernando J.; Mendes, Renio S.; Itami, Andreia S.; Picoli, Sergio

    2015-06-01

    Lottery is the most famous branch among all the games of chance. By analysing data from Mega-Sena, the major lottery in Brazil, we investigated the presence of persistent behaviour in the time series of the number of winners. We found that the demand for tickets grew collectively as an exponential driven by the size of the accumulated jackpot. Finally, we identified that a stochastic model grounded on the rolling-over feature of lotteries can generate correlations qualitatively similar to those observed empirically. The model is consistent with the idea that the growth in the number of bets, motivated by the size of the expected jackpot, is a mechanism generator of correlations in an apparently random scenario.

  10. Reproductive traits and number of matings in males and females of Cerambyx welensii (Coleoptera: Cerambycidae) an emergent pest of oaks.

    Science.gov (United States)

    Torres-Vila, L M; Mendiola-Diaz, F J; Conejo-Rodríguez, Y; Sánchez-González, Á

    2016-06-01

    The longhorn beetle Cerambyx welensii is an emerging pest involved in oak decline episodes, whose damage is increasingly reported in dehesa open woodlands. Knowledge of the reproductive biology of C. welensii is a crucial goal due to its new pest status. In this study, we assess the reproductive traits of both sexes in the laboratory (25°C and 60% relative humidity ). In females, body length was 44.9 ± 0.9 mm (mean ± SE), fecundity 132 ± 12 eggs, fertility 70 ± 1 %, longevity 70 ± 3 days, preoviposition period 2 ± 0.2 days, oviposition period 44 ± 3 days and postoviposition period 19 ± 3 days. Fecundity was positively correlated with female size, longevity and oviposition period. Daily fecundity was 3.0 ± 0.2 eggs/day and showed a fluctuating synovigenic pattern with a slight decreasing trend over time. Egg length was 4.24 ± 0.01 mm and egg volume 8.14 ± 0.04 mm3. Egg size was correlated with female size but the relative size of eggs was larger in smaller females. Incubation time was 13.9 ± 0.1 days and hatching did not depend on egg size. Neonate size was positively correlated with egg length. Females were polyandrous (more than 20 lifetime matings) but multiple mating did not increase fecundity, fertility or longevity. In males, body length was 43.7 ± 0.6 mm and longevity 52 ± 3 days. Unlike with females, longevity was positively correlated with male size. Males were polygynous (up to 30 lifetime matings) but mating history did not affect male longevity. Rather to the contrary, long-lived males mated more times because they had more mating chances. Lastly, C. welensii reproductive traits were compared with those other Cerambycidae species and discussed from an adaptive perspective. Our data will be useful to improve management of C. welensii in order to prevent or mitigate its impact in dehesa woodlands and other oak forests.

  11. Quantifying type-specific reproduction numbers for nosocomial pathogens: evidence for heightened transmission of an Asian sequence type 239 MRSA clone.

    Directory of Open Access Journals (Sweden)

    Ben S Cooper

    Full Text Available An important determinant of a pathogen's success is the rate at which it is transmitted from infected to susceptible hosts. Although there are anecdotal reports that methicillin-resistant Staphylococcus aureus (MRSA clones vary in their transmissibility in hospital settings, attempts to quantify such variation are lacking for common subtypes, as are methods for addressing this question using routinely-collected MRSA screening data in endemic settings. Here we present a method to quantify the time-varying transmissibility of different subtypes of common bacterial nosocomial pathogens using routine surveillance data. The method adapts approaches for estimating reproduction numbers based on the probabilistic reconstruction of epidemic trees, but uses relative hazards rather than serial intervals to assign probabilities to different sources for observed transmission events. The method is applied to data collected as part of a retrospective observational study of a concurrent MRSA outbreak in the United Kingdom with dominant endemic MRSA clones (ST22 and ST36 and an Asian ST239 MRSA strain (ST239-TW in two linked adult intensive care units, and compared with an approach based on a fully parametric transmission model. The results provide support for the hypothesis that the clones responded differently to an infection control measure based on the use of topical antiseptics, which was more effective at reducing transmission of endemic clones. They also suggest that in one of the two ICUs patients colonized or infected with the ST239-TW MRSA clone had consistently higher risks of transmitting MRSA to patients free of MRSA. These findings represent some of the first quantitative evidence of enhanced transmissibility of a pandemic MRSA lineage, and highlight the potential value of tailoring hospital infection control measures to specific pathogen subtypes.

  12. Modelling reproduction of Plutella xylostella L. (Lepidoptera: Plutellidae): climate change may modify pest incidence levels.

    Science.gov (United States)

    Marchioro, C A; Foerster, L A

    2012-08-01

    Temperature is considered to be an important abiotic factor influencing insect reproduction. Despite the importance of Plutella xylostella L. (Lepidoptera: Plutellidae) as a pest of brassicaceous crops worldwide, the effects of temperature on its reproduction are not well understood. We evaluated the effect of constant temperatures ranging from 10 to 32.5°C on the reproduction of P. xylostella and developed an oviposition model for the species. The model combined temperature-dependent parameters of total fecundity, age-specific oviposition rate and age-specific survival. Additionally, we modelled population growth as a function of temperature. The estimated parameters allowed us to discuss the possible consequences of global warming on P. xylostella distribution. Temperature affected the length of pre-oviposition after adult emergence, oviposition period, longevity, total fecundity and egg viability. The model predicted that both daily egg production and length of oviposition period decreased at temperatures below 15°C and above 25°C. Population growth increased linearly with temperature in a range from 10°C to 25°C; however, the model predicted a reduction in population growth at temperatures above 28.6°C. Data suggested that temperature plays a critical role in P. xylostella reproduction, and subtle differences in average temperature could have an impact on its population growth. This is especially important in the context of global climate change, which in turn could alter the distribution and abundance of the pest in some regions of the world.

  13. Effects of temperature on development, survival and reproduction of insects: Experimental design, data analysis and modeling

    Science.gov (United States)

    Jacques Regniere; James Powell; Barbara Bentz; Vincent Nealis

    2012-01-01

    The developmental response of insects to temperature is important in understanding the ecology of insect life histories. Temperature-dependent phenology models permit examination of the impacts of temperature on the geographical distributions, population dynamics and management of insects. The measurement of insect developmental, survival and reproductive responses to...

  14. Number of generations in free fermionic string models

    CERN Document Server

    Giannakis, I; Yuan, K; Giannakis, Ioannis; Nanopoulos, D V; Yuan, Kajia

    1995-01-01

    In string theory there seems to be an intimate connection between spacetime and world-sheet physics. Following this line of thought we investigate the family problem in a particular class of string solutions, namely the free fermionic string models. We find that the number of generations N_g is related to the index of the supersymmetry generator of the underlying N=2 internal superconformal field theory which is always present in any N=1 spacetime supersymmetric string vacuum. We also derive a formula for the index and thus for the number of generations which is sensitive to the boundary condition assignments of the internal fermions and to certain coefficients which determine the weight with which each spin-structure of the model contributes to the one-loop partition function. Finally we apply our formula to several realistic string models in order to derive N_g and we verify our results by constructing explicitly the massless spectrum of these string models.

  15. QSAR models for reproductive toxicity and endocrine disruption in regulatory use - a preliminary investigation

    DEFF Research Database (Denmark)

    Jensen, Gunde Egeskov; Niemela, J.R.; Wedebye, Eva Bay

    2008-01-01

    and epidemiological human studies), dominant lethal effect in rodents (in vivo) and Drosophila melanogaster sex-linked recessive lethal effect. A structure set of 57,014 European Inventory of Existing Chemical Substances (EINECS) chemicals was screened. A total of 5240 EINECS chemicals, corresponding to 9.2%, were...... predicted as reproductive toxicants by one or more of the models. The chemicals predicted positive for reproductive toxicity will be submitted to the Danish Environmental Protection Agency as scientific input for a future updated advisory classification list with advisory classifications for concern...

  16. Toxicity of Nanoparticles on the Reproductive System in Animal Models: A Review

    Directory of Open Access Journals (Sweden)

    Rahim Dad Brohi

    2017-09-01

    Full Text Available In the last two decades, nanotechnologies demonstrated various applications in different fields, including detection, sensing, catalysis, electronics, and biomedical sciences. However, public concerns regarding the well-being of human may hinder the wide utilization of this promising innovation. Although, humans are exposed to airborne nanosized particles from an early age, exposure to such particles has risen dramatically within the last century due to anthropogenic sources of nanoparticles. The wide application of nanomaterials in industry, consumer products, and medicine has raised concerns regarding the potential toxicity of nanoparticles in humans. In this review, the effects of nanomaterials on the reproductive system in animal models are discussed. Females are particularly more vulnerable to nanoparticle toxicity, and toxicity in this population may affect reproductivity and fetal development. Moreover, various types of nanoparticles have negative impacts on male germ cells, fetal development, and the female reproductive system. These impacts are associated with nanoparticle modification, composition, concentration, route of administration, and the species of the animal. Therefore, understanding the impacts of nanoparticles on animal growth and reproduction is essential. Many studies have examined the effects of nanoparticles on primary and secondary target organs, with a concentration on the in vivo and in vitro effects of nanoparticles on the male and female reproductive systems at the clinical, cellular, and molecular levels. This review provides important information regarding organism safety and the potential hazards of nanoparticle use and supports the application of nanotechnologies by minimizing the adverse effects of nanoparticles in vulnerable populations.

  17. Toxicity of Nanoparticles on the Reproductive System in Animal Models: A Review

    Science.gov (United States)

    Brohi, Rahim Dad; Wang, Li; Talpur, Hira Sajjad; Wu, Di; Khan, Farhan Anwar; Bhattarai, Dinesh; Rehman, Zia-Ur; Farmanullah, F.; Huo, Li-Jun

    2017-01-01

    In the last two decades, nanotechnologies demonstrated various applications in different fields, including detection, sensing, catalysis, electronics, and biomedical sciences. However, public concerns regarding the well-being of human may hinder the wide utilization of this promising innovation. Although, humans are exposed to airborne nanosized particles from an early age, exposure to such particles has risen dramatically within the last century due to anthropogenic sources of nanoparticles. The wide application of nanomaterials in industry, consumer products, and medicine has raised concerns regarding the potential toxicity of nanoparticles in humans. In this review, the effects of nanomaterials on the reproductive system in animal models are discussed. Females are particularly more vulnerable to nanoparticle toxicity, and toxicity in this population may affect reproductivity and fetal development. Moreover, various types of nanoparticles have negative impacts on male germ cells, fetal development, and the female reproductive system. These impacts are associated with nanoparticle modification, composition, concentration, route of administration, and the species of the animal. Therefore, understanding the impacts of nanoparticles on animal growth and reproduction is essential. Many studies have examined the effects of nanoparticles on primary and secondary target organs, with a concentration on the in vivo and in vitro effects of nanoparticles on the male and female reproductive systems at the clinical, cellular, and molecular levels. This review provides important information regarding organism safety and the potential hazards of nanoparticle use and supports the application of nanotechnologies by minimizing the adverse effects of nanoparticles in vulnerable populations. PMID:28928662

  18. Age at menarche and natural menopause and number of reproductive years in association with mortality: results from a median follow-up of 11.2 years among 31,955 naturally menopausal Chinese women.

    Directory of Open Access Journals (Sweden)

    Xiaoyan Wu

    Full Text Available Studies conducted in Western countries suggest that early age at menarche and early age at menopause are both associated with increased total mortality, but limited data are available for Asian populations. We examined associations of age at menarche and natural menopause and duration of the reproductive span with mortality in a population-based cohort study of Chinese women.We evaluated the effects of age at menarche, age at natural menopause, and number of reproductive years on total and cause-specific mortality among 31,955 naturally menopausal Chinese women who participated in the Shanghai Women's Health Study, a population-based, prospective cohort study.A total of 3,158 deaths occurred during a median follow-up of 11.2 years. Results from Cox proportional hazards models showed that younger age at menopause (<46.64 years was associated with higher risk of total mortality (Ptrend= 0.02. Younger age at menarche (<14 years was associated with higher risk of mortality from stroke (Ptrend= 0.03 and diabetes (Ptrend = 0.02 but lower risk of mortality from respiratory system cancer (Ptrend = 0.01. Women with a shorter reproductive span had lower risk of mortality from gynecological cancers (Ptrend = 0.03.Our study found that menstrual characteristics are important predictors of mortality, suggesting an important role of sex hormones in biological aging.

  19. Reproductive/developmental toxicity and immunotoxicity assessment in the nonhuman primate model

    International Nuclear Information System (INIS)

    Buse, Eberhard; Habermann, Gunnar; Osterburg, Ingrid; Korte, Rainhart; Weinbauer, Gerhard F.

    2003-01-01

    Nonhuman primates are being used increasingly as a non-rodent animal model during preclinical toxicology and safety assessment on the basis of proven similarity and comparability between nonhuman primates and humans. The validity of the nonhuman primate models applies to many aspects of toxicological testing and holds particularly true for the evaluation of reproductive toxicology and developmental toxicology. More recently, the advent of humanized antibodies and vaccines imposed further demand on nonhuman primate models since many immunotherapeutics do not interact with rodent receptors but frequently only cross-react with primate tissue. In this paper we discuss the suitability of primate models for reproductive, developmental and immunotoxicology testing, and present our initial data on the development of lymphatic organs and immune system in a nonhuman primate model

  20. Genetic architecture and postzygotic reproductive isolation: evolution of Bateson-Dobzhansky-Muller incompatibilities in a polygenic model.

    Science.gov (United States)

    Fierst, Janna L; Hansen, Thomas F

    2010-03-01

    The Bateson-Dobzhansky-Muller model predicts that postzygotic isolation evolves due to the accumulation of incompatible epistatic interactions, but few studies have quantified the relationship between genetic architecture and patterns of reproductive divergence. We examined how the direction and magnitude of epistatic interactions in a polygenic trait under stabilizing selection influenced the evolution of hybrid incompatibilities. We found that populations evolving independently under stabilizing selection experienced suites of compensatory allelic changes that resulted in genetic divergence between populations despite the maintenance of a stable, high-fitness phenotype. A small number of loci were then incompatible with multiple alleles in the genetic background of the hybrid and the identity of these incompatibility loci changed over the evolution of the populations. For F(1) hybrids, reduced fitness evolved in a window of intermediate strengths of epistatic interactions, but F(2) and backcross hybrids evolved reduced fitness across weak and moderate strengths of epistasis due to segregation variance. Strong epistatic interactions constrained the allelic divergence of parental populations and prevented the development of reproductive isolation. Because many traits with varying genetic architectures must be under stabilizing selection, our results indicate that polygenetic drift is a plausible hypothesis for the evolution of postzygotic reproductive isolation.

  1. A tale of two morphs: modeling pollen transfer, magic traits, and reproductive isolation in parapatry.

    Science.gov (United States)

    Haller, Benjamin C; de Vos, Jurriaan M; Keller, Barbara; Hendry, Andrew P; Conti, Elena

    2014-01-01

    The evolution of the flower is commonly thought to have spurred angiosperm diversification. Similarly, particular floral traits might have promoted diversification within specific angiosperm clades. We hypothesize that traits promoting the precise positional transfer of pollen between flowers might promote diversification. In particular, precise pollen transfer might produce partial reproductive isolation that facilitates adaptive divergence between parapatric populations differing in their reproductive-organ positions. We investigate this hypothesis with an individual-based model of pollen transfer dynamics associated with heterostyly, a floral syndrome that depends on precise pollen transfer. Our model shows that precise pollen transfer can cause sexual selection leading to divergence in reproductive-organ positions between populations served by different pollinators, pleiotropically causing an increase in reproductive isolation through a "magic trait" mechanism. Furthermore, this increased reproductive isolation facilitates adaptive divergence between the populations in an unlinked, ecologically selected trait. In a different pollination scenario, however, precise pollen transfer causes a decrease in adaptive divergence by promoting asymmetric gene flow. Our results highlight the idea that magic traits are not "magic" in isolation; in particular, the effect size of magic traits in speciation depends on the external environment, and also on other traits that modify the strength of the magic trait's influence on non-random mating. Overall, we show that the evolutionary consequences of pollen transfer dynamics can depend strongly on the available pollinator fauna and on the morphological fit between flowers and pollinators. Furthermore, our results illustrate the potential importance of even weak reproductive isolating barriers in facilitating adaptive divergence.

  2. Numbers, systems, people: how interactions influence integration. Insights from case studies of HIV and reproductive health services delivery in Kenya.

    Science.gov (United States)

    Mayhew, Susannah H; Sweeney, Sedona; Warren, Charlotte E; Collumbien, Martine; Ndwiga, Charity; Mutemwa, Richard; Lut, Irina; Colombini, Manuela; Vassall, Anna

    2017-11-01

    Drawing on rich data from the Integra evaluation of integrated HIV and reproductive-health services, we explored the interaction of systems hardware and software factors to explain why some facilities were able to implement and sustain integrated service delivery while others were not. This article draws on detailed mixed-methods data for four case-study facilities offering reproductive-health and HIV services between 2009 and 2013 in Kenya: (i) time-series client flow, tracking service uptake for 8841 clients; (ii) structured questionnaires with 24 providers; (iii) in-depth interviews with 17 providers; (iv) workload and facility data using a periodic activity review and cost-instruments; and (v) contextual data on external activities related to integration in study sites. Overall, our findings suggested that although structural factors like stock-outs, distribution of staffing and workload, rotation of staff can affect how integrated care is provided, all these factors can be influenced by staff themselves: both frontline and management. Facilities where staff displayed agency of decision making, worked as a team to share workload and had management that supported this, showed better integration delivery and staff were able to overcome some structural deficiencies to enable integrated care. Poor-performing facilities had good structural integration, but staff were unable to utilize this because they were poorly organized, unsupported or teams were dysfunctional. Conscientious objection and moralistic attitudes were also barriers.Integra has demonstrated that structural integration is not sufficient for integrated service delivery. Rather, our case studies show that in some cases excellent leadership and peer-teamwork enabled facilities to perform well despite resource shortages. The ability to provide support for staff to work flexibly to deliver integrated services and build resilient health systems to meet changing needs is particularly relevant as health

  3. Modeling users' activity on Twitter networks: validation of Dunbar's number

    Science.gov (United States)

    Goncalves, Bruno; Perra, Nicola; Vespignani, Alessandro

    2012-02-01

    Microblogging and mobile devices appear to augment human social capabilities, which raises the question whether they remove cognitive or biological constraints on human communication. In this paper we analyze a dataset of Twitter conversations collected across six months involving 1.7 million individuals and test the theoretical cognitive limit on the number of stable social relationships known as Dunbar's number. We find that the data are in agreement with Dunbar's result; users can entertain a maximum of 100-200 stable relationships. Thus, the ``economy of attention'' is limited in the online world by cognitive and biological constraints as predicted by Dunbar's theory. We propose a simple model for users' behavior that includes finite priority queuing and time resources that reproduces the observed social behavior.

  4. Modeling users' activity on twitter networks: validation of Dunbar's number.

    Directory of Open Access Journals (Sweden)

    Bruno Gonçalves

    Full Text Available Microblogging and mobile devices appear to augment human social capabilities, which raises the question whether they remove cognitive or biological constraints on human communication. In this paper we analyze a dataset of Twitter conversations collected across six months involving 1.7 million individuals and test the theoretical cognitive limit on the number of stable social relationships known as Dunbar's number. We find that the data are in agreement with Dunbar's result; users can entertain a maximum of 100-200 stable relationships. Thus, the 'economy of attention' is limited in the online world by cognitive and biological constraints as predicted by Dunbar's theory. We propose a simple model for users' behavior that includes finite priority queuing and time resources that reproduces the observed social behavior.

  5. Fuzzy model for predicting the number of deformed wheels

    Directory of Open Access Journals (Sweden)

    Ž. Đorđević

    2015-10-01

    Full Text Available Deformation of the wheels damage cars and rails and affect on vehicle stability and safety. Repair and replacement cause high costs and lack of wagons. Planning of maintenance of wagons can not be done without estimates of the number of wheels that will be replaced due to wear and deformation in a given period of time. There are many influencing factors, the most important are: weather conditions, quality of materials, operating conditions, and distance between the two replacements. The fuzzy logic model uses the collected data as input variables to predict the output variable - number of deformed wheels for a certain type of vehicle in the defined period at a particular section of the railway.

  6. Modelling protocells the emergent synchronization of reproduction and molecular replication

    CERN Document Server

    Serra, Roberto

    2017-01-01

    The monograph discusses models of synthetic protocells, which are cell-like structures obtained from non-living matter endowed with some rudimentary kind of metabolism and genetics, but much simpler than biological cells. They should grow and proliferate, generating offsprings that resemble in some way the parent protocells with some variation, so that selection may take place. Sustainable protocell populations have not yet been obtained experimentally and mathematical models are therefore extremely important to address key questions concerning their synthesis and behavior. Different protocell “architectures” have been proposed and high-level abstract models like those that are presented in this book are particularly relevant to gain a better understanding of the different properites. These models are able to treat all the major dynamical phenomena in a unified framework, so they can be seen as “virtual laboratories” for protocell research. Particular attention is paid to the problem of synchronizatio...

  7. Too Many PhD Graduates or Too Few Academic Job Openings: The Basic Reproductive Number R0 in Academia.

    Science.gov (United States)

    Larson, Richard C; Ghaffarzadegan, Navid; Xue, Yi

    2014-01-01

    The academic job market has become increasingly competitive for PhD graduates. In this note, we ask the basic question of 'Are we producing more PhDs than needed?' We take a systems approach and offer a 'birth rate' perspective: professors graduate PhDs who later become professors themselves, an analogue to how a population grows. We show that the reproduction rate in academia is very high. For example, in engineering, a professor in the US graduates 7.8 new PhDs during his/her whole career on average, and only one of these graduates can replace the professor's position. This implies that in a steady state, only 12.8% of PhD graduates can attain academic positions in the USA. The key insight is that the system in many places is saturated, far beyond capacity to absorb new PhDs in academia at the rates that they are being produced. Based on the analysis, we discuss policy implications.

  8. Baryon number dissipation at finite temperature in the standard model

    International Nuclear Information System (INIS)

    Mottola, E.; Raby, S.; Starkman, G.

    1990-01-01

    We analyze the phenomenon of baryon number violation at finite temperature in the standard model, and derive the relaxation rate for the baryon density in the high temperature electroweak plasma. The relaxation rate, γ is given in terms of real time correlation functions of the operator E·B, and is directly proportional to the sphaleron transition rate, Γ: γ preceq n f Γ/T 3 . Hence it is not instanton suppressed, as claimed by Cohen, Dugan and Manohar (CDM). We show explicitly how this result is consistent with the methods of CDM, once it is recognized that a new anomalous commutator is required in their approach. 19 refs., 2 figs

  9. Integrative rodent models for assessing male reproductive toxicity of environmental endocrine active substances

    Directory of Open Access Journals (Sweden)

    Jacques Auger

    2014-02-01

    Full Text Available In the present review, we first summarize the main benefits, limitations and pitfalls of conventional in vivo approaches to assessing male reproductive structures and functions in rodents in cases of endocrine active substance (EAS exposure from the postulate that they may provide data that can be extrapolated to humans. Then, we briefly present some integrated approaches in rodents we have recently developed at the organism level. We particularly focus on the possible effects and modes of action (MOA of these substances at low doses and in mixtures, real-life conditions and at the organ level, deciphering the precise effects and MOA on the fetal testis. It can be considered that the in vivo experimental EAS exposure of rodents remains the first choice for studies and is a necessary tool (together with the epidemiological approach for understanding the reproductive effects and MOA of EASs, provided the pitfalls and limitations of the rodent models are known and considered. We also provide some evidence that classical rodent models may be refined for studying the multiple consequences of EAS exposure, not only on the reproductive axis but also on various hormonally regulated organs and tissues, among which several are implicated in the complex process of mammalian reproduction. Such models constitute an interesting way of approaching human exposure conditions. Finally, we show that organotypic culture models are powerful complementary tools, especially when focusing on the MOA. All these approaches have contributed in a combinatorial manner to a better understanding of the impact of EAS exposure on human reproduction.

  10. Towards greater realism in inclusive fitness models: the case of worker reproduction in insect societies.

    Science.gov (United States)

    Wenseleers, Tom; Helanterä, Heikki; Alves, Denise A; Dueñez-Guzmán, Edgar; Pamilo, Pekka

    2013-01-01

    The conflicts over sex allocation and male production in insect societies have long served as an important test bed for Hamilton's theory of inclusive fitness, but have for the most part been considered separately. Here, we develop new coevolutionary models to examine the interaction between these two conflicts and demonstrate that sex ratio and colony productivity costs of worker reproduction can lead to vastly different outcomes even in species that show no variation in their relatedness structure. Empirical data on worker-produced males in eight species of Melipona bees support the predictions from a model that takes into account the demographic details of colony growth and reproduction. Overall, these models contribute significantly to explaining behavioural variation that previous theories could not account for.

  11. Conceptual Model of Business Situation of Attraction and Reproduction of Temporary Personnel of the Event Service

    Directory of Open Access Journals (Sweden)

    Donets Oleksiy S.

    2014-01-01

    Full Text Available The article considers importance of formation of the acting system of personnel management, since personnel determines the competitive potential and competitive advantages of an organisation. It develops a cognitive model of a business situation, which helps to present the process of attraction and reproduction of temporary personnel at enterprises, which deal with organisation of large-scale events, and influence of the factors upon each other. It builds a conceptual model of a business situation of attraction and reproduction of temporary personnel of the event service and, on its basis, offers a model of decision making with the use of elements of fuzzy logic on selection of a specialist for a specific position. It allocates main characteristics of employees, which are taken into account when forming decisions regarding taking on a candidate.

  12. Reproductive number and serial interval of the first wave of influenza A(H1N1pdm09 virus in South Africa.

    Directory of Open Access Journals (Sweden)

    Brett N Archer

    Full Text Available Describing transmissibility parameters of past pandemics from diverse geographic sites remains critical to planning responses to future outbreaks. We characterize the transmissibility of influenza A(H1N1pdm09 (hereafter pH1N1 in South Africa during 2009 by estimating the serial interval (SI, the initial effective reproductive number (initial R(t and the temporal variation of R(t.We make use of data from a central registry of all pH1N1 laboratory-confirmed cases detected throughout South Africa. Whenever date of symptom onset is missing, we estimate it from the date of specimen collection using a multiple imputation approach repeated 100 times for each missing value. We apply a likelihood-based method (method 1 for simultaneous estimation of initial R(t and the SI; estimate initial R(t from SI distributions established from prior field studies (method 2; and the Wallinga and Teunis method (method 3 to model the temporal variation of R(t.12,360 confirmed pH1N1 cases were reported in the central registry. During the period of exponential growth of the epidemic (June 21 to August 3, 2009, we simultaneously estimate a mean R(t of 1.47 (95% CI: 1.30-1.72 and mean SI of 2.78 days (95% CI: 1.80-3.75 (method 1. Field studies found a mean SI of 2.3 days between primary cases and laboratory-confirmed secondary cases, and 2.7 days when considering both suspected and confirmed secondary cases. Incorporating the SI estimate from field studies using laboratory-confirmed cases, we found an initial R(t of 1.43 (95% CI: 1.38-1.49 (method 2. The mean R(t peaked at 2.91 (95% CI: 0.85-2.91 on June 21, as the epidemic commenced, and R(t>1 was sustained until August 22 (method 3.Transmissibility characteristics of pH1N1 in South Africa are similar to estimates reported by countries outside of Africa. Estimations using the likelihood-based method are in agreement with field findings.

  13. Modeling of dynamically loaded hydrodynamic bearings at low Sommerfeld numbers

    DEFF Research Database (Denmark)

    Thomsen, Kim

    and failure risk of rolling element bearings do, however, grow exponentially with the size. Therefore hydrodynamic bearings can prove to be a competitive alternative to the current practice of rolling element bearings and ultimately help reducing the cost and carbon footprint of renewable energy generation....... The challenging main bearing operation conditions in a wind turbine pose a demanding development task for the design of a hydrodynamic bearing. In general these conditions include operation at low Reynolds numbers with frequent start and stop at high loads as well as difficult operating conditions dictated...... by environment and other wind turbine components. In this work a numerical multiphysics bearing model is developed in order to allow for accurate performance prediction of hydrodynamic bearings subjected to the challenging conditions that exist in modern wind turbines. This requires the coupling of several...

  14. Modelling the number of olive groves in Spanish municipalities

    Energy Technology Data Exchange (ETDEWEB)

    Huete, M.D.; Marmolejo, J.A.

    2016-11-01

    The univariate generalized Waring distribution (UGWD) is presented as a new model to describe the goodness of fit, applicable in the context of agriculture. In this paper, it was used to model the number of olive groves recorded in Spain in the 8,091 municipalities recorded in the 2009 Agricultural Census, according to which the production of oil olives accounted for 94% of total output, while that of table olives represented 6% (with an average of 44.84 and 4.06 holdings per Spanish municipality, respectively). UGWD is suitable for fitting this type of discrete data, with strong left-sided asymmetry. This novel use of UGWD can provide the foundation for future research in agriculture, with the advantage over other discrete distributions that enables the analyst to split the variance. After defining the distribution, we analysed various methods for fitting the parameters associated with it, namely estimation by maximum likelihood, estimation by the method of moments and a variant of the latter, estimation by the method of frequencies and moments. For oil olives, the chi-square goodness of fit test gives p-values of 0.9992, 0.9967 and 0.9977, respectively. However, a poor fit was obtained for the table olive distribution. Finally, the variance was split, following Irwin, into three components related to random factors, external factors and internal differences. For the distribution of the number of olive grove holdings, this splitting showed that random and external factors only account about 0.22% and 0.05%. Therefore, internal differences within municipalities play an important role in determining total variability. (Author)

  15. Modelling the number of olive groves in Spanish municipalities

    Directory of Open Access Journals (Sweden)

    María-Dolores Huete

    2016-03-01

    Full Text Available The univariate generalized Waring distribution (UGWD is presented as a new model to describe the goodness of fit, applicable in the context of agriculture. In this paper, it was used to model the number of olive groves recorded in Spain in the 8,091 municipalities recorded in the 2009 Agricultural Census, according to which the production of oil olives accounted for 94% of total output, while that of table olives represented 6% (with an average of 44.84 and 4.06 holdings per Spanish municipality, respectively. UGWD is suitable for fitting this type of discrete data, with strong left-sided asymmetry. This novel use of UGWD can provide the foundation for future research in agriculture, with the advantage over other discrete distributions that enables the analyst to split the variance. After defining the distribution, we analysed various methods for fitting the parameters associated with it, namely estimation by maximum likelihood, estimation by the method of moments and a variant of the latter, estimation by the method of frequencies and moments. For oil olives, the chi-square goodness of fit test gives p-values of 0.9992, 0.9967 and 0.9977, respectively. However, a poor fit was obtained for the table olive distribution. Finally, the variance was split, following Irwin, into three components related to random factors, external factors and internal differences. For the distribution of the number of olive grove holdings, this splitting showed that random and external factors only account about 0.22% and 0.05%. Therefore, internal differences within municipalities play an important role in determining total variability.

  16. Assessing reproductive toxicity of two environmental toxicants with a novel in vitro human spermatogenic model

    Directory of Open Access Journals (Sweden)

    Charles A. Easley, IV

    2015-05-01

    Full Text Available Environmental influences and insults by reproductive toxicant exposure can lead to impaired spermatogenesis or infertility. Understanding how toxicants disrupt spermatogenesis is critical for determining how environmental factors contribute to impaired fertility. While current animal models are available, understanding of the reproductive toxic effects on human fertility requires a more robust model system. We recently demonstrated that human pluripotent stem cells can differentiate into spermatogonial stem cells/spermatogonia, primary and secondary spermatocytes, and haploid spermatids; a model that mimics many aspects of human spermatogenesis. Here, using this model system, we examine the effects of 2-bromopropane (2-BP and 1,2,dibromo-3-chloropropane (DBCP on in vitro human spermatogenesis. 2-BP and DBCP are non-endocrine disrupting toxicants that are known to impact male fertility. We show that acute treatment with either 2-BP or DBCP induces a reduction in germ cell viability through apoptosis. 2-BP and DBCP affect viability of different cell populations as 2-BP primarily reduces spermatocyte viability, whereas DBCP exerts a much greater effect on spermatogonia. Acute treatment with 2-BP or DBCP also reduces the percentage of haploid spermatids. Both 2-BP and DBCP induce reactive oxygen species (ROS formation leading to an oxidized cellular environment. Taken together, these results suggest that acute exposure with 2-BP or DBCP causes human germ cell death in vitro by inducing ROS formation. This system represents a unique platform for assessing human reproductive toxicity potential of various environmental toxicants in a rapid, efficient, and unbiased format.

  17. Rapid evolution and copy number variation of primate RHOXF2, an X-linked homeobox gene involved in male reproduction and possibly brain function

    Directory of Open Access Journals (Sweden)

    Zhang Rui

    2011-10-01

    Full Text Available Abstract Background Homeobox genes are the key regulators during development, and they are in general highly conserved with only a few reported cases of rapid evolution. RHOXF2 is an X-linked homeobox gene in primates. It is highly expressed in the testicle and may play an important role in spermatogenesis. As male reproductive system is often the target of natural and/or sexual selection during evolution, in this study, we aim to dissect the pattern of molecular evolution of RHOXF2 in primates and its potential functional consequence. Results We studied sequences and copy number variation of RHOXF2 in humans and 16 nonhuman primate species as well as the expression patterns in human, chimpanzee, white-browed gibbon and rhesus macaque. The gene copy number analysis showed that there had been parallel gene duplications/losses in multiple primate lineages. Our evidence suggests that 11 nonhuman primate species have one RHOXF2 copy, and two copies are present in humans and four Old World monkey species, and at least 6 copies in chimpanzees. Further analysis indicated that the gene duplications in primates had likely been mediated by endogenous retrovirus (ERV sequences flanking the gene regions. In striking contrast to non-human primates, humans appear to have homogenized their two RHOXF2 copies by the ERV-mediated non-allelic recombination mechanism. Coding sequence and phylogenetic analysis suggested multi-lineage strong positive selection on RHOXF2 during primate evolution, especially during the origins of humans and chimpanzees. All the 8 coding region polymorphic sites in human populations are non-synonymous, implying on-going selection. Gene expression analysis demonstrated that besides the preferential expression in the reproductive system, RHOXF2 is also expressed in the brain. The quantitative data suggests expression pattern divergence among primate species. Conclusions RHOXF2 is a fast-evolving homeobox gene in primates. The rapid

  18. Effects of nanotoxicity on female reproductivity and fetal development in animal models.

    Science.gov (United States)

    Sun, Jianling; Zhang, Qiu; Wang, Zhiping; Yan, Bing

    2013-04-29

    The extensive application of nanomaterials in industry, medicine and consumer products has raised concerns about their potential toxicity. The female population is particularly vulnerable and deserves special attention because toxicity in this group may impact both female reproductivity and fetal development. Mouse and zebrafish models each have their own unique features and studies using these models to examine the potential toxicity of various nanoparticles are compared and summarized in this review. Several nanoparticles exhibit detrimental effects on female reproductivity as well as fetal development, and these adverse effects are related to nanoparticle composition, surface modification, dose, exposure route and animal species. Limited studies on the mechanisms of nanotoxicity are also documented and reviewed herein.

  19. Effects of Nanotoxicity on Female Reproductivity and Fetal Development in Animal Models

    Directory of Open Access Journals (Sweden)

    Jianling Sun

    2013-04-01

    Full Text Available The extensive application of nanomaterials in industry, medicine and consumer products has raised concerns about their potential toxicity. The female population is particularly vulnerable and deserves special attention because toxicity in this group may impact both female reproductivity and fetal development. Mouse and zebrafish models each have their own unique features and studies using these models to examine the potential toxicity of various nanoparticles are compared and summarized in this review. Several nanoparticles exhibit detrimental effects on female reproductivity as well as fetal development, and these adverse effects are related to nanoparticle composition, surface modification, dose, exposure route and animal species. Limited studies on the mechanisms of nanotoxicity are also documented and reviewed herein.

  20. Penerapan Strategi Numbered Head Together dalam Setting Model Pembelajaran STAD

    Directory of Open Access Journals (Sweden)

    Muhammad Mifta Fausan

    2016-07-01

    Full Text Available This study aims to determine the increase of motivation and biology student learning outcomes through the implementation of Numbered Head Together (NHT strategies in setting Student Teams Achievement Division (STAD learning model based Lesson Study (LS. Subjects in this study were students of class X IS 1 MAN 3 Malang. Implementation this study consisted of two cycles and each cycle consisted of three meetings. The data obtained were analyzed using descriptive statistical analysis of qualitative and quantitative descriptive statistics. The research instrument used is the observation sheet, test, monitoring LS sheets and questionnaires. The results of this study indicate that through the implementation of NHT strategy in setting STAD learning model based LS can improve motivation and learning outcomes biology students. Students' motivation in the first cycle of 69% and increased in the second cycle of 86%. While the cognitive learning, classical completeness in the first cycle of 74% and increased in the second cycle to 93%. Affective learning outcomes of students in the first cycle by 93% and increased in the second cycle to 100%. Furthermore, psychomotor learning outcomes of students also increased from 74% in the first cycle to 93% in the second cycle.

  1. A Reproductive Threat-Based Model of Evolved Sex Differences in Jealousy

    OpenAIRE

    Brad J. Sagarin; D. Vaughn Becker; Rosanna E. Guadagno; Wayne W. Wilkinson; Lionel D. Nicastle

    2012-01-01

    Although heterosexual women and men consistently demonstrate sex differences in jealousy, these differences disappear among lesbians and gay men as well as among heterosexual women and men contemplating same-sex infidelities (infidelities in which the partner and rival are the same sex). Synthesizing these past findings, the present paper offers a reproductive threat-based model of evolved sex differences in jealousy that predicts that the sexes will differ only when the jealous perceivers' r...

  2. A lifelong model for the female reproductive cycle with an antimüllerian hormone treatment to delay menopause.

    Science.gov (United States)

    Margolskee, Alison; Selgrade, James F

    2013-06-07

    A system of 16 non-linear, delay differential equations with 66 parameters is developed to model hormonal regulation of the menstrual cycle of a woman from age 20 to 51. This mechanistic model predicts changes in follicle numbers and reproductive hormones that naturally occur over that time span. In particular, the model illustrates the decline in the pool of primordial follicles from age 20 to menopause as reported in the biological literature. Also, model simulations exhibit a decrease in antimüllerian hormone (AMH) and inhibin B and an increase in FSH with age corresponding to the experimental data. Model simulations using the administration of exogenous AMH show that the transfer of non-growing primordial follicles to the active state can be slowed enough to provide more follicles for development later in life and to cause a delay in the onset of menopause as measured by the number of primordial follicles remaining in the ovaries. Other effects of AMH agonists and antagonists are investigated in the setting of this model. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Sons conceived by assisted reproduction techniques inherit deletions in the azoospermia factor (AZF) region of the Y chromosome and the DAZ gene copy number

    DEFF Research Database (Denmark)

    Mau Kai, C; Juul, A; McElreavey, K

    2008-01-01

    BACKGROUND: Deletions in the azoospermia factor (AZF) region of the Y chromosome are frequent in infertile men. The clinical consequences and the mode of inheritance of these deletions are not yet clear. METHODS: Y chromosome deletion mapping and quantitative PCR analysis of the DAZ-gene copy...... number, supplemented with haplogroup typing in deleted patients, were performed, in combination with clinical assessments in 264 fathers and their sons conceived by assisted reproduction techniques (ART), and in 168 fertile men with normal sperm concentration. RESULTS: In the ART fathers group......, which needs confirmation in further studies in larger cohorts. However, deletions of two DAZ gene copies are compatible with normal spermatogenesis and fertility Udgivelsesdato: 2008/7...

  4. Sexual differentiation of the brain: a model for drug-induced alterations of the reproductive system

    International Nuclear Information System (INIS)

    Gorski, R.A.

    1986-01-01

    The process of the sexual differentiation of the brain represents a valuable model system for the study of the chemical modification of the mammalian brain. Although there are numerous functional and structural sex differences in the adult brain, these are imposed on an essentially feminine or bipotential brain by testicular hormones during a critical phase of perinatal development in the rat. It is suggested that a relatively marked structural sex difference in the rat brain, the sexually dimorphic nucleus of the preoptic area (SDN-POA), is a morphological signature of the permanent or organizational action of estradiol derived from the aromatization of testicular testosterone. The SDN-POA of the male rat is severalfold larger in volume and is composed of more neurons than that of the female. The observation that the mitotic formation of the neurons of the SDN-POA is specifically prolonged has enabled us to identify the time course and pathway of neuronal migration into the nucleus. Study of the development of the SDN-POA suggests that estradiol in the male increases the number of neurons which survive a phase of neuronal death by exerting a neurite growth promoting action and/or a direct neuronotrophic action. Finally, although it is clear that gonadal hormones have dramatic permanent effects on the brain during perinatal development, even after puberty and in adulthood gonadal steroids can alter neuronal structure and, perhaps as a corollary to this, have permanent effects on reproductive function. Although the brain may be most sensitive to gonadal hormones or exogenous chemical factors during perinatal development, such as sensitivity does not appear limited to this period

  5. Natural and sexual selection giveth and taketh away reproductive barriers: models of population divergence in guppies.

    Science.gov (United States)

    Labonne, Jacques; Hendry, Andrew P

    2010-07-01

    The standard predictions of ecological speciation might be nuanced by the interaction between natural and sexual selection. We investigated this hypothesis with an individual-based model tailored to the biology of guppies (Poecilia reticulata). We specifically modeled the situation where a high-predation population below a waterfall colonizes a low-predation population above a waterfall. Focusing on the evolution of male color, we confirm that divergent selection causes the appreciable evolution of male color within 20 generations. The rate and magnitude of this divergence were reduced when dispersal rates were high and when female choice did not differ between environments. Adaptive divergence was always coupled to the evolution of two reproductive barriers: viability selection against immigrants and hybrids. Different types of sexual selection, however, led to contrasting results for another potential reproductive barrier: mating success of immigrants. In some cases, the effects of natural and sexual selection offset each other, leading to no overall reproductive isolation despite strong adaptive divergence. Sexual selection acting through female choice can thus strongly modify the effects of divergent natural selection and thereby alter the standard predictions of ecological speciation. We also found that under no circumstances did divergent selection cause appreciable divergence in neutral genetic markers.

  6. Estimating the basic reproduction rate of HFMD using the time series SIR model in Guangdong, China.

    Directory of Open Access Journals (Sweden)

    Zhicheng Du

    Full Text Available Hand, foot, and mouth disease (HFMD has caused a substantial burden of disease in China, especially in Guangdong Province. Based on notifiable cases, we use the time series Susceptible-Infected-Recovered model to estimate the basic reproduction rate (R0 and the herd immunity threshold, understanding the transmission and persistence of HFMD more completely for efficient intervention in this province. The standardized difference between the reported and fitted time series of HFMD was 0.009 (<0.2. The median basic reproduction rate of total, enterovirus 71, and coxsackievirus 16 cases in Guangdong were 4.621 (IQR: 3.907-5.823, 3.023 (IQR: 2.289-4.292 and 7.767 (IQR: 6.903-10.353, respectively. The heatmap of R0 showed semiannual peaks of activity, including a major peak in spring and early summer (about the 12th week followed by a smaller peak in autumn (about the 36th week. The county-level model showed that Longchuan (R0 = 33, Gaozhou (R0 = 24, Huazhou (R0 = 23 and Qingxin (R0 = 19 counties have higher basic reproduction rate than other counties in the province. The epidemic of HFMD in Guangdong Province is still grim, and strategies like the World Health Organization's expanded program on immunization need to be implemented. An elimination of HFMD in Guangdong might need a Herd Immunity Threshold of 78%.

  7. AVERT2 (a very early rehabilitation trial, a very effective reproductive trigger): retrospective observational analysis of the number of babies born to trial staff.

    Science.gov (United States)

    Bernhardt, Julie; Lindley, Richard I; Lalor, Erin; Ellery, Fiona; Chamberlain, Jan; Van Holsteyn, John; Collier, Janice M; Dewey, Helen M; Parsons, Brooke; Moodie, Marjory; Lennon, Sheila; Donnan, Geoffrey A; Thrift, Amanda G; Churilov, Leonid; Langhorne, Peter

    2015-12-11

    To report the number of participants needed to recruit per baby born to trial staff during AVERT, a large international trial on acute stroke, and to describe trial management consequences. Retrospective observational analysis. 56 acute stroke hospitals in eight countries. 1074 trial physiotherapists, nurses, and other clinicians. Number of babies born during trial recruitment per trial participant recruited. With 198 site recruitment years and 2104 patients recruited during AVERT, 120 babies were born to trial staff. Births led to an estimated 10% loss in time to achieve recruitment. Parental leave was linked to six trial site closures. The number of participants needed to recruit per baby born was 17.5 (95% confidence interval 14.7 to 21.0); additional trial costs associated with each birth were estimated at 5736 Australian dollars on average. The staff absences registered in AVERT owing to parental leave led to delayed trial recruitment and increased costs, and should be considered by trial investigators when planning research and estimating budgets. However, the celebration of new life became a highlight of the annual AVERT collaborators' meetings and helped maintain a cohesive collaborative group. Australian New Zealand Clinical Trials Registry no 12606000185561. Participation in a rehabilitation trial does not guarantee successful reproductive activity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  8. A daily herd Markov-chain model to study the reproductive and economic impact of reproductive programs combining timed artificial insemination and estrus detection.

    Science.gov (United States)

    Giordano, J O; Kalantari, A S; Fricke, P M; Wiltbank, M C; Cabrera, V E

    2012-09-01

    Our objective was to compare the economic and reproductive performance of programs combining timed artificial insemination (TAI) and different levels of AI after estrus detection (ED) using a daily Markov-chain model. A dairy herd was modeled with every cow following daily probabilistic events of aging, replacement, mortality, pregnancy, pregnancy loss, and calving. The probability of pregnancy depended on the combination of probability of insemination and conception rate (CR). All nonpregnant cows had a probability of pregnancy between the end of the voluntary waiting period and days in milk cutoff for AI. After the cutoff, cows were labeled as do not breed and replaced when milk production was below a minimum milk threshold. A similar model was created to represent a replacement heifer herd to simulate and adjust the supply and demand of replacements. The net value (NV) of a program was the sum of milk income over feed cost, replacement and mortality cost, income from newborns, and reproductive costs. The model was used to compare the NV of 19 programs. One program used 100% TAI (42% CR for first TAI and 30% for second-and-later services), whereas the other programs combined TAI with ED. The proportion of cows receiving AI after ED for the combined programs ranged from 30 to 80%, with levels of CR of 25, 30, and 35%. As the proportion of cows receiving AI after ED increased, the CR of cows receiving TAI decreased. The combined programs with CR of 35% for cows receiving AI after ED had the greatest NV and reproductive performance at all levels of ED. The program using 100% TAI had greater NV and better reproductive performance than all programs with 25% CR after ED inseminations, whereas it had very similar performance to combined programs with up to 60% of cows receiving AI after ED and 30% CR. The factor with the greatest relative contribution to the differences among programs was income over feed cost, followed by replacement and reproductive costs. Adjusting

  9. Reproductive Failure

    African Journals Online (AJOL)

    The need for the establishment of a Reproductive Failure. Clinic at Groote Schuur Hospital was considered long overdue, as it was felt that there were a number of high risk pregnancies continually being lost among the large volume of pregnant women attending the routine, busy and overcrowded antenatal clinics,. Various ...

  10. Franchising reproductive health services.

    Science.gov (United States)

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

    2004-12-01

    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. 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. 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. 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.

  11. A survey of basic reproductive ratios in vector-borne disease transmission modeling

    Science.gov (United States)

    Soewono, E.; Aldila, D.

    2015-03-01

    Vector-borne diseases are commonly known in tropical and subtropical countries. These diseases have contributed to more than 10% of world infectious disease cases. Among the vectors responsible for transmitting the diseases are mosquitoes, ticks, fleas, flies, bugs and worms. Several of the diseases are known to contribute to the increasing threat to human health such as malaria, dengue, filariasis, chikungunya, west nile fever, yellow fever, encephalistis, and anthrax. It is necessary to understand the real process of infection, factors which contribute to the complication of the transmission in order to come up with a good and sound mathematical model. Although it is not easy to simulate the real transmission process of the infection, we could say that almost all models have been developed from the already long known Host-Vector model. It constitutes the main transmission processes i.e. birth, death, infection and recovery. From this simple model, the basic concepts of Disease Free and Endemic Equilibria and Basic Reproductive Ratio can be well explained and understood. Theoretical, modeling, control and treatment aspects of disease transmission problems have then been developed for various related diseases. General construction as well as specific forms of basic reproductive ratios for vector-borne diseases are discusses here.

  12. Geographic parthenogenesis in a consumer-resource model for sexual reproduction.

    Science.gov (United States)

    Song, Yixian; Scheu, Stefan; Drossel, Barbara

    2011-03-21

    The phenomenon of geographic parthenogenesis is closely tied to the question of why sexual reproduction is the dominant mode of reproduction in animals and plants. Geographic parthenogenesis describes the fact that many species reproduce asexually at the boundaries of their range. We present a mathematical model that derives the dominance of sexuals at the center and the dominance of asexuals at the boundary of a species' range from exactly the same mechanism. Our model is based on a set of resources that regrow slowly and that can be consumed only by those individuals that have a suitable genotype. Genotype is implemented by a multilocus model with two alleles at each locus, and with free recombination during production of sexual offspring. The model is tailored to seasonal species with intermittent mixis and low survival of offspring, such as Daphnia and aphids. Several patches of resources are arranged in a row, with a gradient of those parameters that typically vary through the range of species. By letting sexually and asexually reproducing populations compete, we obtain the typical patterns of geographic parthenogenesis. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. A Cyberspace Command and Control Model (Maxwell Paper, Number 47)

    Science.gov (United States)

    2009-08-01

    Norbert Wiener , Cyber- netics: Or the Control and Communication in the Animal and the Machine [Cambridge, MA: MIT Press, 1948]; and Ludwig von Bertalanffy...or external change has successfully aligned with the system’s goal. Cybernetic Model The Basic Cybernetic Model (sources: Wiener , 1948; von... Wiener , 1948) EMERGED OUT OF WWII AND IS THE FOUNDATION OF THE OVERWHELMING MAJORITY OF C2 MODELS Figure 4 The Cybernetic Model. (Adapted from

  14. DOSE DEPENDENT EFFECTS OF SILVER NANOPARTICLES ON REPRODUCTION AND DEVELOPMENT OF DIFFERENT BIOLOGICAL MODELS

    Directory of Open Access Journals (Sweden)

    Carla Falugi

    2012-07-01

    Full Text Available The aim of this study was to investigate the possible impact of silver nanoparticles (Ag-NPs on reproduction and development of different model organisms, such as sea urchins, barnacles, brine shrimps and zebrafish. In vivo toxicological tests were performed; the biological models were exposed to serial dilutions of commercial Ag-NPs. Our findings revealed that: i all tests were suitable to verify the impact of Ag-NPs on models in term of exposure; ii all tests can provide an idea of the role of NPs on environmental health; iii an integrated interdisciplinary approach, using several model organisms, is recommended in order to have an overview of the effects of NPs on water environment.

  15. Modelling of high-enthalpy, high-Mach number flows

    International Nuclear Information System (INIS)

    Degrez, G; Lani, A; Panesi, M; Chazot, O; Deconinck, H

    2009-01-01

    A review is made of the computational models of high-enthalpy flows developed over the past few years at the von Karman Institute and Universite Libre de Bruxelles, for the modelling of high-enthalpy hypersonic (re-)entry flows. Both flows in local thermo-chemical equilibrium (LTE) and flows in thermo-chemical non-equilibrium (TCNEQ) are considered. First, the physico-chemical models are described, i.e. the set of conservation laws, the thermodynamics, transport phenomena and chemical kinetics models. Particular attention is given to the correct modelling of elemental (LTE flows) and species (chemical non-equilibrium-CNEQ-flows) transport. The numerical algorithm, based on a state-of-the-art finite volume discretization, is then briefly described. Finally, selected examples are included to illustrate the capabilities of the developed solver. (review article)

  16. Intergenerational conflicts may help explain parental absence effects on reproductive timing: a model of age at first birth in humans

    Directory of Open Access Journals (Sweden)

    Cristina Moya

    2014-08-01

    Full Text Available Background. Parental absences in childhood are often associated with accelerated reproductive maturity in humans. These results are counterintuitive for evolutionary social scientists because reductions in parental investment should be detrimental for offspring, but earlier reproduction is generally associated with higher fitness. In this paper we discuss a neglected hypothesis that early reproduction is often associated with parental absence because it decreases the average relatedness of a developing child to her future siblings. Family members often help each other reproduce, meaning that parents and offspring may find themselves in competition over reproductive opportunities. In these intergenerational negotiations offspring will have less incentive to help the remaining parent rear future half-siblings relative to beginning reproduction themselves.Method. We illustrate this “intergenerational conflict hypothesis” with a formal game-theoretic model.Results. We show that when resources constrain reproductive opportunities within the family, parents will generally win reproductive conflicts with their offspring, i.e., they will produce more children of their own and therefore delay existing offsprings’ reproduction. This is due to the asymmetric relatedness between grandparents and grandchildren (r = .25, compared to siblings (r = 0.5, resulting in greater incentives for older siblings to help rear younger siblings than for grandparents to help rear grandchildren. However, if a parent loses or replaces their partner, the conflict between the parent and offspring becomes symmetric since half siblings are as related to one another as grandparents are to grandchildren. This means that the offspring stand to gain more from earlier reproduction when their remaining parent would produce half, rather than full, siblings. We further show that if parents senesce in a way that decreases the quality of their infant relative to their offspring

  17. Study and discretization of kinetic models and fluid models at low Mach number

    International Nuclear Information System (INIS)

    Dellacherie, Stephane

    2011-01-01

    This thesis summarizes our work between 1995 and 2010. It concerns the analysis and the discretization of Fokker-Planck or semi-classical Boltzmann kinetic models and of Euler or Navier-Stokes fluid models at low Mach number. The studied Fokker-Planck equation models the collisions between ions and electrons in a hot plasma, and is here applied to the inertial confinement fusion. The studied semi-classical Boltzmann equations are of two types. The first one models the thermonuclear reaction between a deuterium ion and a tritium ion producing an α particle and a neutron particle, and is also in our case used to describe inertial confinement fusion. The second one (known as the Wang-Chang and Uhlenbeck equations) models the transitions between electronic quantified energy levels of uranium and iron atoms in the AVLIS isotopic separation process. The basic properties of these two Boltzmann equations are studied, and, for the Wang-Chang and Uhlenbeck equations, a kinetic-fluid coupling algorithm is proposed. This kinetic-fluid coupling algorithm incited us to study the relaxation concept for gas and immiscible fluids mixtures, and to underline connections with classical kinetic theory. Then, a diphasic low Mach number model without acoustic waves is proposed to model the deformation of the interface between two immiscible fluids induced by high heat transfers at low Mach number. In order to increase the accuracy of the results without increasing computational cost, an AMR algorithm is studied on a simplified interface deformation model. These low Mach number studies also incited us to analyse on cartesian meshes the inaccuracy at low Mach number of Godunov schemes. Finally, the LBM algorithm applied to the heat equation is justified

  18. Parker's sneak-guard model revisited: why do reproductively parasitic males heavily invest in testes?

    Science.gov (United States)

    Ota, Kazutaka; Kohda, Masanori; Hori, Michio; Sato, Tetsu

    2011-10-01

    Alternative reproductive tactics are widespread in males and may cause intraspecific differences in testes investment. Parker's sneak-guard model predicts that sneaker males, who mate under sperm competition risk, invest in testes relatively more than bourgeois conspecifics that have lower risk. Given that sneakers are much smaller than bourgeois males, sneakers may increase testes investment to overcome their limited sperm productivity because of their small body sizes. In this study, we examined the mechanism that mediates differential testes investment across tactics in the Lake Tanganyika cichlid fish Lamprologus callipterus. In the Rumonge population of Burundi, bourgeois males are small compared with those in other populations and have a body size close to sneaky dwarf males. Therefore, if differences in relative testis investment depend on sperm competition, the rank order of relative testis investment should be dwarf males > bourgeois males in Rumonge = bourgeois males in the other populations. If differences in relative testis investment depend on body size, the rank order of relative testes investment should be dwarf males > bourgeois males in Rumonge > bourgeois males in the other populations. Comparisons of relative testis investment among the three male groups supported the role of sperm competition, as predicted by the sneak-guard model. Nevertheless, the effects of absolute body size on testes investment should be considered to understand the mechanisms underlying intraspecific variation in testes investment caused by alternative reproductive tactics.

  19. A Reproductive Threat-Based Model of Evolved Sex Differences in Jealousy

    Directory of Open Access Journals (Sweden)

    Brad J. Sagarin

    2012-07-01

    Full Text Available Although heterosexual women and men consistently demonstrate sex differences in jealousy, these differences disappear among lesbians and gay men as well as among heterosexual women and men contemplating same-sex infidelities (infidelities in which the partner and rival are the same sex. Synthesizing these past findings, the present paper offers a reproductive threat-based model of evolved sex differences in jealousy that predicts that the sexes will differ only when the jealous perceivers' reproductive outcomes are differentially at risk. This model is supported by data from a web-based study in which lesbians, gay men, bisexual women and men, and heterosexual women and men responded to a hypothetical infidelity scenario with the sex of the rival randomly determined. After reading the scenario, participants indicated which type of infidelity (sexual versus emotional would cause greater distress. Consistent with predictions, heterosexual women and men showed a sex difference when contemplating opposite-sex infidelities but not when contemplating same-sex infidelities, whereas lesbians and gay men showed no sex difference regardless of whether the infidelity was opposite-sex or same-sex.

  20. A reproductive threat-based model of evolved sex differences in jealousy.

    Science.gov (United States)

    Sagarin, Brad J; Becker, D Vaughn; Guadagno, Rosanna E; Wilkinson, Wayne W; Nicastle, Lionel D

    2012-08-10

    Although heterosexual women and men consistently demonstrate sex differences in jealousy, these differences disappear among lesbians and gay men as well as among heterosexual women and men contemplating same-sex infidelities (infidelities in which the partner and rival are the same sex). Synthesizing these past findings, the present paper offers a reproductive threat-based model of evolved sex differences in jealousy that predicts that the sexes will differ only when the jealous perceivers' reproductive outcomes are differentially at risk. This model is supported by data from a web-based study in which lesbians, gay men, bisexual women and men, and heterosexual women and men responded to a hypothetical infidelity scenario with the sex of the rival randomly determined. After reading the scenario, participants indicated which type of infidelity (sexual versus emotional) would cause greater distress. Consistent with predictions, heterosexual women and men showed a sex difference when contemplating opposite-sex infidelities but not when contemplating same-sex infidelities, whereas lesbians and gay men showed no sex difference regardless of whether the infidelity was opposite-sex or same-sex.

  1. Naloxone affects reproductive system in a rat model with polycystic features

    Directory of Open Access Journals (Sweden)

    Manizheh Karami

    2015-03-01

    Conclusion: Aspect of rat reproductive system may be linked with the cystic characteristic of ovary. This study involves opioid receptors in the naloxone efficacy on reproductive agents of rat with polycystic aspect.

  2. Animal models of physiologic markers of male reproduction: genetically defined infertile mice

    Energy Technology Data Exchange (ETDEWEB)

    Chubb, C.

    1987-10-01

    The present report focuses on novel animal models of male infertility: genetically defined mice bearing single-gene mutations that induce infertility. The primary goal of the investigations was to identify the reproductive defects in these mutant mice. The phenotypic effects of the gene mutations were deciphered by comparing the mutant mice to their normal siblings. Initially testicular steroidogenesis and spermatogenesis were investigated. The physiologic markers for testicular steroidogenesis were steroid secretion by testes perifused in vitro, seminal vesicle weight, and Leydig cell histology. Spermatogenesis was evaluated by the enumeration of homogenization-resistant sperm/spermatids in testes and by morphometric analyses of germ cells in the seminiferous epithelium. If testicular function appeared normal, the authors investigated the sexual behavior of the mice. The parameters of male sexual behavior that were quantified included mount patency, mount frequency, intromission latency, thrusts per intromission, ejaculation latency, and ejaculation duration. Females of pairs breeding under normal circumstances were monitored for the presence of vaginal plugs and pregnancies. The patency of the ejaculatory process was determined by quantifying sperm in the female reproductive tract after sexual behavior tests. Sperm function was studied by quantitatively determining sperm motility during videomicroscopic observation. Also, the ability of epididymal sperm to function within the uterine environment was analyzed by determining sperm capacity to initiate pregnancy after artificial insemination. Together, the experimental results permitted the grouping of the gene mutations into three general categories. They propose that the same biological markers used in the reported studies can be implemented in the assessment of the impact that environmental toxins may have on male reproduction.

  3. The Baryon Number Two System in the Chiral Soliton Model

    International Nuclear Information System (INIS)

    Mantovani-Sarti, V.; Drago, A.; Vento, V.; Park, B.-Y.

    2013-01-01

    We study the interaction between two B = 1 states in a chiral soliton model where baryons are described as non-topological solitons. By using the hedgehog solution for the B = 1 states we construct three possible B = 2 configurations to analyze the role of the relative orientation of the hedgehog quills in the dynamics. The strong dependence of the inter soliton interaction on these relative orientations reveals that studies of dense hadronic matter using this model should take into account their implications. (author)

  4. The Number of Atomic Models of Uncountable Theories

    OpenAIRE

    Ulrich, Douglas

    2016-01-01

    We show there exists a complete theory in a language of size continuum possessing a unique atomic model which is not constructible. We also show it is consistent with $ZFC + \\aleph_1 < 2^{\\aleph_0}$ that there is a complete theory in a language of size $\\aleph_1$ possessing a unique atomic model which is not constructible. Finally we show it is consistent with $ZFC + \\aleph_1 < 2^{\\aleph_0}$ that for every complete theory $T$ in a language of size $\\aleph_1$, if $T$ has uncountable atomic mod...

  5. Realistic Matematic Approach through Numbered Head Together Learning Model

    Science.gov (United States)

    Sugihatno, A. C. M. S.; Budiyono; Slamet, I.

    2017-09-01

    Recently, the teaching process which is conducted based on teacher center affect the students interaction in the class. It causes students become less interest to participate. That is why teachers should be more creative in designing learning using other types of cooperative learning model. Therefore, this research is aimed to implement NHT with RMA in the teaching process. We utilize NHT since it is a variant of group discussion whose aim is giving a chance to the students to share their ideas related to the teacher’s question. By using NHT in the class, a teacher can give a better understanding about the material which is given with the help of Realistic Mathematics Approach (RMA) which known for its real problem contex. Meanwhile, the researcher assumes instead of selecting teaching model, Adversity Quotient (AQ) of student also influences students’ achievement. This research used the quasi experimental research. The samples is 60 students in junior high school, it was taken by using the stratified cluster random sampling technique. The results show NHT-RMA gives a better learning achievement of mathematics than direct teaching model and NHT-RMA teaching model with categorized as high AQ show different learning achievement from the students with categorized as moderate and low AQ.

  6. Increased mast cell numbers in a calcaneal tendon overuse model

    DEFF Research Database (Denmark)

    Pingel, Jessica; Wienecke, Jacob; Kongsgaard Madsen, Mads

    2013-01-01

    Tendinopathy is often discovered late because the initial development of tendon pathology is asymptomatic. The aim of this study was to examine the potential role of mast cell involvement in early tendinopathy using a high-intensity uphill running (HIUR) exercise model. Twenty-four male Wistar ra...

  7. Transmission of a heterologous clade C Symbiodinium in a model anemone infection system via asexual reproduction

    Directory of Open Access Journals (Sweden)

    Wan-Nan U. Chen

    2016-08-01

    Full Text Available Anemones of genus Exaiptasia are used as model organisms for the study of cnidarian-dinoflagellate (genus Symbiodinium endosymbiosis. However, while most reef-building corals harbor Symbiodinium of clade C, Exaiptasia spp. anemones mainly harbor clade B Symbiodinium (ITS2 type B1 populations. In this study, we reveal for the first time that bleached Exaiptasia pallida anemones can establish a symbiotic relationship with a clade C Symbiodinium (ITS2 type C1. We further found that anemones can transmit the exogenously supplied clade C Symbiodinium cells to their offspring by asexual reproduction (pedal laceration. In order to corroborate the establishment of stable symbiosis, we used microscopic techniques and genetic analyses to examine several generations of anemones, and the results of these endeavors confirmed the sustainability of the system. These findings provide a framework for understanding the differences in infection dynamics between homologous and heterologous dinoflagellate types using a model anemone infection system.

  8. The effect of DNA repair defects on reproductive performance in nucleotide excision repair (NER) mouse models: an epidemiological approach

    NARCIS (Netherlands)

    Tsai, P.S.; Nielen, M.; Horst, G.T.J. van der; Colenbrander, B.; Heesterbeek, J.A.P.; Fentener van Vlissingen, J.M.

    2005-01-01

    In this study, we used an epidemiological approach to analyze an animal database of DNA repair deficient mice on reproductive performance in five Nucleotide Excision Repair (NER) mutant mouse models on a C57BL/6 genetic background, namely CSA, CSB, XPA, XPC [models for the human DNA repair disorders

  9. The reproduction accuracy for stereolithographic model of the thyroid gland derived from the visible human dataset.

    Science.gov (United States)

    Kapakin, Samet; Demiryurek, Deniz

    2009-07-01

    To investigate reproduction accuracy of the rapid prototyping technique by comparing 3-dimensional computer-aided design (CAD) (virtual) model with stereolithographic (solid) replica of the thyroid gland. The Visible Human Dataset was used as the input imaging data. The Surfdriver software package was applied on these images to reconstruct the thyroid gland as 3-dimensional Data Exchange File (DXF) models. These models were post-processed in Cinema 4D and 3D-Doctor software for Virtual Reality Modeling Language (VRML) and Standard Triangulation Language (STL) formats. Stereolithographic replica was manufactured in the rapid prototyping machine using STL format. This study was conducted between June 1-30, 2008 at the Department of Anatomy, Hacettepe University, Ankara, Turkey. An excellent agreement was found in comparing the maximal dimensions of the CAD model of the thyroid gland and the corresponding stereolithographic model. Visual and tactile examination of the thyroid gland model allowed correct depiction of the thyroid gland anatomy. The accuracy of the stereolithographic model was attained by comparing wih the CAD model. Dimensional analysis showed that an average difference between the measurements on the virtual and the solid model was 0.09 mm (p=0.06), ranging from 0.07-0.92 mm. Thyroid volume and surface area were calculated to be 25393.9 mm3 and 8242.8 mm2 using 3D-Doctor software, which were agreement with those obtained from Brunn's formula. Stereolithographic biomodeling is a state-of-the-art and reliable method of visualizing anatomoclinical structures and abnormalities.

  10. Caenorhabditis elegans as a Model for Toxic Effects of Nanoparticles: Lethality, Growth, and Reproduction.

    Science.gov (United States)

    Maurer, Laura L; Ryde, Ian T; Yang, Xinyu; Meyer, Joel N

    2015-11-02

    The nematode Caenorhabditis elegans is extensively utilized in toxicity studies. C. elegans offers a high degree of homology with higher organisms, and its ease of use and relatively inexpensive maintenance have made it an attractive complement to mammalian and ecotoxicological models. C. elegans provides multiple benefits, including the opportunity to perform relatively high-throughput assays on whole organisms, a wide range of genetic tools permitting investigation of mechanisms and genetic sensitivity, and transparent bodies that facilitate toxicokinetic studies. This unit describes protocols for three nanotoxicity assays in C. elegans: lethality, growth, and reproduction. This unit focuses on how to use these well-established assays with nanoparticles, which are being produced in ever-increasing volume and exhibit physicochemical properties that require alteration of standard toxicity assays. These assays permit a broad phenotypic assessment of nanotoxicity in C. elegans, and, when used in combination with genetic tools and other assays, also permit mechanistic insight. Copyright © 2015 John Wiley & Sons, Inc.

  11. Separated shear-layer instability reproduction by a Reynolds stress model of turbulence

    Science.gov (United States)

    Jakirlic, Suad; Maduta, Robert

    2013-11-01

    A boundary layer separating from a solid wall transforms into a `separated shear layer' exhibiting a broader frequency range. Such a highly-unsteady shear layer separating the mean stream from the flow reversal is dominated by the organized, large-scale coherent structures, influencing to a large extent the overall flow behavior. Unlike in the case of a flat-plate boundary layer separating at a fixed point characterizing a backward-facing step geometry, which can be reasonably well captured by a statistical model of turbulence, the separation process pertinent to continuous curved surfaces as well as some fence- or rib-shaped configurations is beyond the reach of any RANS (Reynolds-Averaged Navier Stokes) model independent of the modeling level. The latter issue motivated the present work, dealing with an appropriate extension of a near-wall Second-Moment Closure (SMC) model towards an instability-sensitive formulation. The production term in the corresponding scale-supplying equation is selectively enhanced through introduction of the ratio of the first to the second derivative of the velocity field, the latter representing the integral part of the von Karman length scale, enabling appropriate capturing of the fluctuating turbulence and accordingly the reproduction of the separated shear-layer instability. The analysis is performed by simulating the flow separated from a fence, an axisymmetric hill and a cylinder configuration.

  12. [Integrated Quality Management System (IQMS): a model for improving the quality of reproductive health care in rural Kenya].

    Science.gov (United States)

    Herrler, Claudia; Bramesfeld, Anke; Brodowski, Marc; Prytherch, Helen; Marx, Irmgard; Nafula, Maureen; Richter-Aairijoki, Heide; Musyoka, Lucy; Marx, Michael; Szecsenyi, Joachim

    2015-01-01

    To develop a model aiming to improve the quality of services for reproductive health care in rural Kenya and designed to measure the quality of reproductive health services in such a way that allows these services to identify measures for improving their performance. The Integrated Quality Management System (IQMS) was developed on the basis of a pre-existing and validated model for quality promotion, namely the European Practice Assessment (EPA). The methodology for quality assessment and feedback of assessment results to the service teams was adopted from the EPA model. Quality assessment methodology included data assessment through staff, patient surveys and service visitation. Quality is assessed by indicators, and so indicators had to be developed that were appropriate for assessing reproductive health care in rural Kenya. A search of the Kenyan and international literature was conducted to identify potential indicators. These were then rated for their relevance and clarity by a panel of Kenyan experts. 260 indicators were rated as relevant and assigned to 29 quality dimensions and 5 domains. The implementation of IQMS in ten facilities showed that IQMS is a feasible model for assessing the quality of reproductive health services in rural Kenya. IQMS enables these services to identify quality improvement targets and necessary improvement measures. Both strengths and limitations of IQMS will be discussed. Copyright © 2015. Published by Elsevier GmbH.

  13. Red jungle fowl (Gallus gallus) as a model for studying the molecular mechanism of seasonal reproduction.

    Science.gov (United States)

    Ono, Hiroko; Nakao, Nobuhiro; Yamamura, Takashi; Kinoshita, Keiji; Mizutani, Makoto; Namikawa, Takao; Iigo, Masayuki; Ebihara, Shizufumi; Yoshimura, Takashi

    2009-06-01

    Photoperiodism is an adaptation mechanism that enables animals to predict seasonal changes in the environment. Japanese quail is the best model organism for studying photoperiodism. Although the recent availability of chicken genome sequences has permitted the expansion from single gene to genome-wide transcriptional analysis in this organism, the photoperiodic response of the domestic chicken is less robust than that of the quail. Therefore, in the present study, we examined the photoperiodic response of the red jungle fowl (Gallus gallus), a predecessor of the domestic chicken, to test whether this animal could be developed as an ideal model for studying the molecular mechanisms of seasonal reproduction. When red jungle fowls were transferred from short-day- to long-day conditions, gonadal development and an increase in plasma LH concentration were observed. Furthermore, rapid induction of thyrotropin beta subunit, a master regulator of photoperiodism, was observed at 16 h after dawn on the first long day. In addition, the long-day condition induced the expression of type 2 deiodinase, the key output gene of photoperiodism. These results were consistent with the results obtained in quail and suggest that the red jungle fowl could be an ideal model animal for the genome-wide transcriptional analysis of photoperiodism.

  14. A dynamic-bioenergetics model to assess depth selection and reproductive growth by lake trout (Salvelinus namaycush).

    Science.gov (United States)

    Plumb, John M; Blanchfield, Paul J; Abrahams, Mark V

    2014-06-01

    We coupled dynamic optimization and bioenergetics models to assess the assumption that lake trout (Salvelinus namaycush) depth distribution is structured by temperature, food availability, and predation risk to maximize reproductive mass by autumn spawning. Because the model uses empirical daily thermal-depth profiles recorded in a small boreal shield lake (lake 373 at the Experimental Lakes Area, northwestern Ontario) during 2 years of contrasting thermal stratification patterns, we also assessed how climate-mediated changes in lakes may affect the vertical distribution, growth, and fitness of lake trout, a cold-water top predator. The depths of acoustic-tagged lake trout were recorded concurrently with thermal-depth profiles and were compared to model output, enabling an assessment of model performance in relation to the observed fish behavior and contrasting thermal conditions. The depths and temperatures occupied by simulated fish most closely resembled those of the tagged fish when risk of predation was included in the model, indicating the model may incorporate the most important underlying mechanisms that determine lake trout depth. Annual differences suggest less use of shallow (warm), productive habitats, resulting in markedly less reproductive mass, during the year with the warm stratification pattern. Mass for reproduction may be lower in warmer conditions because of reduced reproductive investment, yet survival may be inadvertently higher because risky surface waters may be avoided more often in warmer, shallower, and metabolically costly conditions. At a minimum our study suggests that lake trout reproductive mass and fitness may be expected to change under the anticipated longer and warmer stratification patterns.

  15. Reproductive Health Education Model in Early Childhood through Education Film "Damar Wulan"

    Science.gov (United States)

    Zahrulianingdyah, Atiek

    2015-01-01

    Reproductive health education for early childhood it has been the time to teach, because the demand of the changing times and will affect the child's life when he/she is a teenager. During this time, the reproductive health education, which is in it there is sex education, considered taboo among some communities. They argue that the reproductive…

  16. Reproductive endocrinology of vitamin D

    DEFF Research Database (Denmark)

    Lorenzen, Mette; Boisen, Ida Marie; Mortensen, Li Juel

    2017-01-01

    Vitamin D is a versatile hormone with several functions beyond its well-established role in maintenance of skeletal health and calcium homeostasis. The effects of vitamin D are mediated by the vitamin D receptor, which is expressed together with the vitamin D metabolizing enzymes...... in the reproductive tissues. The reproductive organs are therefore responsive to and able to metabolize vitamin D locally. The exact role remains to be clarified but several studies have suggested a link between vitamin D and production/release of reproductive hormones into circulation, which will be the main focus...... of this review. Current evidence is primarily based on small human association studies and rodent models. This highlights the need for randomized clinical trials, but also functional animal and human in vitro studies, and larger, prospective cohort studies are warranted. Given the high number of men and women...

  17. Mental models in journalistic discourse and on Facebook: the (reproduction of knowledge about #OcupeEstelita

    Directory of Open Access Journals (Sweden)

    Laura Jorge Nogueira Cavalcanti

    2016-07-01

    Full Text Available In this study we analyzed the comments written in response to a post by the action #OcupeEstelita on Facebook, and two newspaper stories in order to understand the cognitive-discursive relations established between distinct social groups. We adopted Van Dijk’s socio-cognitive perspective (2010, 2012, analyzing the categorization (LAKOFF, 1987; LANGACKER, 1987, the nominalization, and referentiation (MONDADA; DUBOIS, 2003 processes, as well as the manner how information is organized in news pieces (VAN DIJK, 1988, in order to recover the mental models created about the action, its representatives, and the social issues in question. We observed that the journalistic media tends to develop a pejorative conceptualization of the action; that the action places itself as the guardian of social-democratic interests; and that comments on Facebook tend to reproduce the same event models developed by the journalistic media. We realized, thus, that the role of conceptualization through discourse in the (reproduction of socially relevant knowledge is at stake in this discursive clash.

  18. Peningkatan Hasil Belajar PKn Materi Organisasi melalui Model Numbered Head Together di Kelas V

    Directory of Open Access Journals (Sweden)

    Endah Tri Wahyuni

    2017-11-01

    Full Text Available Penelitian peningkatan hasil belajar pendidikan kewarganegaraan melalui model Numbered Heads Together bertujuan untuk mendeskripsikan penerapan model Numbered Heads Together dalam pendidikan kewarganegaraan dengan materi organisasi dan menggambarkan peningkatan hasil belajar siswa dengan menggunakan model Numbered Heads Together. Ini akan sangat berguna bagi siswa dan guru dalam belajar. Model Numbered Heads Together juga dapat meningkatkan aktivitas guru dan siswa. Penelitian ini merupakan penelitian tindakan kelas. Hasil penelitian menunjukkan (1 Penerapan model pembelajaran Numbered Heads Together pada pembelajaran PKn dilaksanakan guru dengan baik dan sesuai dengan langkah-langkah pembelajaran Numbered Heads Together, (2 siklus I, ketuntasan belajar klasikal mengalami peningkatan sebesar 67% dengan kualifikasi cukup dan pada siklus II ketuntasan klasikal meningkat menjadi 92% dengan kualifikasi sangat baik.

  19. Number-average size model for geological systems and its application in economic geology

    Directory of Open Access Journals (Sweden)

    Q. F. Wang

    2011-07-01

    Full Text Available Various natural objects follow a number-size relationship in the fractal domain. In such relationship, the accumulative number of the objects beyond a given size shows a power-law relationship with the size. Yet in most cases, we also need to know the relationship between the accumulative number of the objects and their average size. A generalized number-size model and a number-average size model are constructed in this paper. In the number-average size model, the accumulative number shows a power-law relationship with the average size when the given size is much less than the maximum size of the objects. When the fractal dimension Ds of the number-size model is smaller than 1, the fractal dimension Ds of the number-average size model is almost equal to 1; and when Ds > 1, the Dm is approximately equal to Ds. In mineral deposits, according to the number-average size model, the ore tonnage may show a fractal relationship with the grade, as the cutoff changes for a single ore deposit. This is demonstrated by a study of the relationship between tonnage and grade in the Reshuitang epithermal hot-spring gold deposit, China.

  20. Reproduction and evaluation of a rat model of inhalation lung injury caused by black gunpowder smog

    Directory of Open Access Journals (Sweden)

    Yi-fan LIU

    2013-09-01

    Full Text Available Objective To reproduce and evaluate a rat model of inhalation lung injury caused by black gunpowder smog. Methods The smog composition was analyzed and a rat model of inhalation lung injury was reproduced. Forty two healthy male Wistar rats were randomly divided into normal control (NC group and 1h, 2h, 6h, 24h, 48h and 96h after inhalation group (n=6. The arterial blood gas, wet to dry weight ratio (W/D of lung, leukocyte count, and protein concentration in broncho-alveolar lavage fluid (BALF were determined. Macroscopic and microscopic changes in lung tissue were observed. Results The composition of black gunpowder smog was composed mainly of CO2 and CO, and their concentrations remained stable within 12 minutes. Smog inhalation caused a significant hypoxemia, the concentration of blood COHb reached a peak value 1h, and the W/D of lung reached peak value 2h after inhalation (P<0.05. The amount of leukocytes and content of protein in BALF increased significantly within 24h after inhalation (P<0.05. Histopathological observation showed diffuse hemorrhage, edema and inflammatory cell infiltration in lung tissue as manifestations of acute lung injury, and the injury did not recover at 96h after inhalation. Conclusion The rat model of inhalation lung injury can be reproduced using black gunpowder smog, and it has the advantages of its readiness for reproduction, reliability and stability, and it could be used for the experiment of inhalation injury in a battlefield environment.

  1. Effect of Nigella sativa on reproductive system in experimental menopause rat model

    Directory of Open Access Journals (Sweden)

    Saadat Parhizkar

    2016-01-01

    Full Text Available Objective: Menopause is the condition when regular menstrual periods cease and may be accompanied by psychological and physical symptoms. The purpose of current study was to determine Nigella sativa effects on reproductive system in experimental menopause animal models. Materials and Methods: A series of experiments wasconducted to investigate the effects of different dosages of N. sativa (first experiment, various extracts of N. sativa (second experimentand some of its ingredients (third experiment on selected menopausal parameters of ovariectomized (OVX rats. Forty different OVX rats were equally divided into 5 groups and administered with one of the following treatments for 21 days: conjugated equine estrogen (positive control, distilled water or olive oil (negative control, treatment groups  (N. sativa300, 600 and 1200 mg/kg in the first experiment, (300mg/kg methanol, hexane and SFE extracts of N. sativa in the second experiment and (linoleic acid 50 mg/kg, gamma linolenic acid 10mg/kg, and thymoquinone 15mg/kg in the third experiment. Results: The results demonstrated that N.sativa exert estrogenic effect were exhibited through uterotrophic assay and vaginal cell cornification as well as blood estrogen level. Furthermore, low dose N. sativa, methanol extract and linoleic acid had prominent estrogenic like effects which were significantly different from those of control group (p

  2. Simulation of a directed random-walk model: the effect of pseudo-random-number correlations

    OpenAIRE

    Shchur, L. N.; Heringa, J. R.; Blöte, H. W. J.

    1996-01-01

    We investigate the mechanism that leads to systematic deviations in cluster Monte Carlo simulations when correlated pseudo-random numbers are used. We present a simple model, which enables an analysis of the effects due to correlations in several types of pseudo-random-number sequences. This model provides qualitative understanding of the bias mechanism in a class of cluster Monte Carlo algorithms.

  3. Reproductive endocrinology of vitamin D.

    Science.gov (United States)

    Lorenzen, Mette; Boisen, Ida Marie; Mortensen, Li Juel; Lanske, Beate; Juul, Anders; Blomberg Jensen, Martin

    2017-09-15

    Vitamin D is a versatile hormone with several functions beyond its well-established role in maintenance of skeletal health and calcium homeostasis. The effects of vitamin D are mediated by the vitamin D receptor, which is expressed together with the vitamin D metabolizing enzymes in the reproductive tissues. The reproductive organs are therefore responsive to and able to metabolize vitamin D locally. The exact role remains to be clarified but several studies have suggested a link between vitamin D and production/release of reproductive hormones into circulation, which will be the main focus of this review. Current evidence is primarily based on small human association studies and rodent models. This highlights the need for randomized clinical trials, but also functional animal and human in vitro studies, and larger, prospective cohort studies are warranted. Given the high number of men and women suffering from reproductive problems and abnormal endocrinology research addressing the role of vitamin D in reproductive endocrinology may be of clinical importance. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Cardiometabolic and reproductive benefits of early dietary energy restriction and voluntary exercise in an obese PCOS-prone rodent model.

    Science.gov (United States)

    Diane, Abdoulaye; Kupreeva, Maria; Borthwick, Faye; Proctor, Spencer D; Pierce, W David; Vine, Donna F

    2015-09-01

    Polycystic ovary syndrome (PCOS) is one of the most common endocrine-metabolic disorders in women of reproductive age characterized by ovulatory dysfunction, hyperandrogenism and cardiometabolic risk. The overweight-obese PCOS phenotype appears to have exacerbated reproductive dysfunction and cardiometabolic risk. In overweight-obese adult women with PCOS, exercise and energy restricted diets have shown limited and inconsistent effects on both cardiometabolic indices and reproductive outcomes. We hypothesized that an early lifestyle intervention involving exercise and dietary energy restriction to prevent or reduce the propensity for adiposity would modulate reproductive indices and cardiometabolic risk in an obese PCOS-prone rodent model. Weanling obese PCOS-prone and Lean-Control JCR:LA-cp rodents were given a chow diet ad libitum or an energy-restricted diet combined with or without voluntary exercise (4  h/day) for 8 weeks. Dietary energy restriction and exercise lowered total body weight gain and body fat mass by 30% compared to free-fed sedentary or exercising obese PCOS-prone animals (PPCOS-prone animals compared to free-fed and exercise or sedentary groups. The energy restriction and exercise combination in obese PCOS-prone animals significantly increased plasma sex-hormone binding globulin, hypothalamic cocaine-and amphetamine-regulated transcript (CART) and Kisspeptin mRNA expression to levels of the Lean-Control group, and this was further associated with improvements in estrous cyclicity. The combination of exercise and dietary energy restriction when initiated in early life exerts beneficial effects on cardiometabolic and reproductive indices in an obese PCOS-prone rodent model, and this may be associated with normalization of the hypothalamic neuropeptides, Kisspeptin and CART. © 2015 Society for Endocrinology.

  5. National collection of embryo morphology data into Society for Assisted Reproductive Technology Clinic Outcomes Reporting System: associations among day 3 cell number, fragmentation and blastomere asymmetry, and live birth rate.

    Science.gov (United States)

    Racowsky, Catherine; Stern, Judy E; Gibbons, William E; Behr, Barry; Pomeroy, Kimball O; Biggers, John D

    2011-05-01

    To evaluate the validity of collecting day 3 embryo morphology variables into the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System (SART CORS). Retrospective. National database-SART CORS. Fresh autologous assisted reproductive technology (ART) cycles from 2006-2007 in which embryos were transferred singly (n=1,020) or in pairs (n=6,508) and embryo morphology was collected. None. Relationship between live birth, maternal age, and morphology of transferred day 3 embryos as defined by cell number, fragmentation, and blastomere symmetry. Logistic multiple regressions and receiver operating characteristic curve analyses were applied to determine specificity and sensitivity for correctly classifying embryos as either failures or successes. Live birth rate was positively associated with increasing cell number up to eight cells (8 cells: 16.2%), but was negatively associated with maternal age, increasing fragmentation, and asymmetry scores. An area under the receiver operating curve of 0.753 (95% confidence interval 0.740-0.766) was derived, with a sensitivity of 45.0%, a specificity of 83.2%, and 76.4% of embryos being correctly classified with a cutoff probability of 0.3. This analysis provides support for the validity of collecting morphology fields for day 3 embryos into SART CORS. Standardization of morphology collections will assist in controlling for embryo quality in future database analyses. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  6. Sensible biological models to be exposed to VDT (Video Display Terminal) radiations in human male reproduction

    International Nuclear Information System (INIS)

    Tritto, J.; North, M.-O.; Laverdure, A.M.; Surbeck, J.

    1999-01-01

    Temperature and environmental effects, particularly endocrine disrupters and EMF radiations, are actively investigated in human and non-human reproduction experimental models. Sensitivity and specificity of the different cell types of the testes seminiferous tubules in animals and in human are evaluated, showing a specific responsiveness of spermatogonia (SPG) and resting pachytene spermatocytes (SPC). At 32 o C the 24 h short-term cultures of biopsies of normal human testis show an expected low occurrence of apoptotic SPG (1 %) that increases to 3,4 % in peer samples exposed to VDT for the same period, with the appearance of apoptotic SPC (4,6 %). In samples from a thermically-impaired testis of the same subject the apoptotic occurrence of SPG is 2,6 % with 15,4 % for SPC after 24 h cultures. After 24 h exposure to VDT the apoptotic score is 7,6 % for SPG and 18,5 % for SPC in thermically impaired peer samples. With EMF-bioshields the apoptotic score for SPG is 0,8 % in normal 2,2 % for SPG and 13,8 % for SPC in T-impaired peer-samples. NMRS of the cultures fluids show a proportional production of lactate, corresponding to the different degrees of histopathological impairment of the samples. IVOS (Integrated Visual Optic System) analysis of sperm samples from thermically-impaired, not-repaired and repaired testes exposed to VDT shows sensible variations on straightness (STR), linearity (LIN) and lateral head displacement (LHD) parameters. To evaluate the thermic and non-thermic potential bioeffects of VDT on human spermatogenesis the specificity, the sensitivity and the reproducibility of the biological models on one side and the specificity of the methodologies on the other side must be provided. (author)

  7. Surface detail reproduction and dimensional accuracy of stone models: influence of disinfectant solutions and alginate impression materials.

    Science.gov (United States)

    Guiraldo, Ricardo Danil; Borsato, Thaís Teixeira; Berger, Sandrine Bittencourt; Lopes, Murilo Baena; Gonini, Alcides; Sinhoreti, Mário Alexandre Coelho

    2012-01-01

    This study compared the surface detail reproduction and dimensional accuracy of stone models obtained from molds disinfected with 2% sodium hypochlorite, 2% chlorhexidine digluconate or 0.2% peracetic acid to models produced using molds which were not disinfected, with 3 alginate materials (Cavex ColorChange, Hydrogum 5 and Jeltrate Plus). The molds were prepared over matrix containing 20-, 50-, and 75-µm lines, performed under pressure with perforated metal tray. The molds were removed following gelation and either disinfected (using one of the solutions by spraying followed by storage in closed jars for 15 min) or not disinfected. The samples were divided into 12 groups (n=5). Molds were filled with dental gypsum Durone IV and 1 h after the start of the stone mixing the models were separated from the tray. Surface detail reproduction and dimensional accuracy were evaluated using optical microscopy on the 50-µm line with 25 mm in length, in accordance with the ISO 1563 standard. The dimensional accuracy results (%) were subjected to ANOVA. The 50 µm-line was completely reproduced by all alginate impression materials regardless of the disinfection procedure. There was no statistically significant difference in the mean values of dimensional accuracy in combinations between disinfectant procedure and alginate impression material (p=0.2130) or for independent factors. The disinfectant solutions and alginate materials used in this study are no factors of choice regarding the surface detail reproduction and dimensional accuracy of stone models.

  8. Mutual tolerance or reproductive competition? Patterns of reproductive skew among male redfronted lemurs (Eulemur fulvus rufus)

    OpenAIRE

    Kappeler, Peter M.; Port, Markus

    2008-01-01

    The social organization of gregarious lemurs significantly deviates from predictions of the socioecological model, as they form small groups in which the number of males approximately equals the number of females. This study uses models of reproductive skew theory as a new approach to explain this unusual group composition, in particular the high number of males, in a representative of these lemurs, the redfronted lemur (Eulemur fulvus rufus). We tested two central predictions of “concession”...

  9. Toward a model framework of generalized parallel componential processing of multi-symbol numbers.

    Science.gov (United States)

    Huber, Stefan; Cornelsen, Sonja; Moeller, Korbinian; Nuerk, Hans-Christoph

    2015-05-01

    In this article, we propose and evaluate a new model framework of parallel componential multi-symbol number processing, generalizing the idea of parallel componential processing of multi-digit numbers to the case of negative numbers by considering the polarity signs similar to single digits. In a first step, we evaluated this account by defining and investigating a sign-decade compatibility effect for the comparison of positive and negative numbers, which extends the unit-decade compatibility effect in 2-digit number processing. Then, we evaluated whether the model is capable of accounting for previous findings in negative number processing. In a magnitude comparison task, in which participants had to single out the larger of 2 integers, we observed a reliable sign-decade compatibility effect with prolonged reaction times for incompatible (e.g., -97 vs. +53; in which the number with the larger decade digit has the smaller, i.e., negative polarity sign) as compared with sign-decade compatible number pairs (e.g., -53 vs. +97). Moreover, an analysis of participants' eye fixation behavior corroborated our model of parallel componential processing of multi-symbol numbers. These results are discussed in light of concurrent theoretical notions about negative number processing. On the basis of the present results, we propose a generalized integrated model framework of parallel componential multi-symbol processing. (c) 2015 APA, all rights reserved).

  10. Normal Female Reproductive Anatomy

    Science.gov (United States)

    ... an inner lining called the endometrium. Normal female reproductive system anatomy. Topics/Categories: Anatomy -- Gynecologic Type: Color, Medical Illustration Source: National Cancer Institute Creator: Terese Winslow (Illustrator) AV Number: CDR609921 Date Created: November 17, 2014 Date Added: ...

  11. Environment, epigenetics and reproduction.

    Science.gov (United States)

    Skinner, Michael K

    2017-07-01

    A conference summary of the third biannual Kenya Africa Conference "Environment, Epigenetics and Reproduction" is provided. A partial special Environmental Epigenetics issue containing a number of papers in Volume 3, Issue 3 and 4 are discussed.

  12. Theories of Socio-Cultural Reproduction.

    Science.gov (United States)

    Passeron, Jean-Claude

    1986-01-01

    Examines various sociological theories of socio-cultural reproduction, devoting special attention to the role of education. Differentiates historical repetition from social reproduction and develops a social-reproduction model. (JDH)

  13. Optimization model using Markowitz model approach for reducing the number of dengue cases in Bandung

    Science.gov (United States)

    Yong, Benny; Chin, Liem

    2017-05-01

    Dengue fever is one of the most serious diseases and this disease can cause death. Currently, Indonesia is a country with the highest cases of dengue disease in Southeast Asia. Bandung is one of the cities in Indonesia that is vulnerable to dengue disease. The sub-districts in Bandung had different levels of relative risk of dengue disease. Dengue disease is transmitted to people by the bite of an Aedesaegypti mosquito that is infected with a dengue virus. Prevention of dengue disease is by controlling the vector mosquito. It can be done by various methods, one of the methods is fogging. The efforts made by the Health Department of Bandung through fogging had constraints in terms of limited funds. This problem causes Health Department selective in fogging, which is only done for certain locations. As a result, many sub-districts are not handled properly by the Health Department because of the unequal distribution of activities to prevent the spread of dengue disease. Thus, it needs the proper allocation of funds to each sub-district in Bandung for preventing dengue transmission optimally. In this research, the optimization model using Markowitz model approach will be applied to determine the allocation of funds should be given to each sub-district in Bandung. Some constraints will be added to this model and the numerical solution will be solved with generalized reduced gradient method using Solver software. The expected result of this research is the proportion of funds given to each sub-district in Bandung correspond to the level of risk of dengue disease in each sub-district in Bandung so that the number of dengue cases in this city can be reduced significantly.

  14. Recreating the female reproductive tract in vitro using iPSC technology in a linked microfluidics environment

    OpenAIRE

    Laronda, Monica M; Burdette, Joanna E; Kim, J Julie; Woodruff, Teresa K

    2013-01-01

    The female reproductive tract produces hormones for reproductive function and cardiovascular, bone and sexual health; the tract supplies a finite number of gametes, and it supports fetal development. Diseases that affect each of the female reproductive tract organs, along with treatments that have direct, deleterious effects on the reproductive tract (for example, chemotherapeutics), are understudied due to the lack of model systems that phenocopy in vivo function. This review describes a pat...

  15. Reproductive Science for High School Students: A Shared Curriculum Model to Enhance Student Success.

    Science.gov (United States)

    Castle, Megan; Cleveland, Charlotte; Gordon, Diana; Jones, Lynda; Zelinski, Mary; Winter, Patricia; Chang, Jeffrey; Senegar-Mitchell, Ericka; Coutifaris, Christos; Shuda, Jamie; Mainigi, Monica; Bartolomei, Marisa; Woodruff, Teresa K

    2016-07-01

    The lack of a national reproductive biology curriculum leads to critical knowledge gaps in today's high school students' comprehensive understanding of human biology. The Oncofertility Consortium developed curricula that address the basic and clinical aspects of reproductive biology. Launching this academy and creating easy-to-disseminate learning modules allowed other universities to implement similar programs across the country. The expansion of this informal, extracurricular academy on reproductive health from Northwestern University to the University of California, San Diego, Oregon Health & Science University, and the University of Pennsylvania magnifies the scope of scientific learning to students who might not otherwise be exposed to this important information. To assess the experience gained from this curriculum, we polled alumni from the four centers. Data were collected anonymously from de-identified users who elected to self-report on their experiences in their respective reproductive science academy. The alumni survey asked participants to report on their current academic standing, past experiences in the academy, and future academic and career goals. The results of this national survey suggest the national oncofertility academies had a lasting impact on participants and may have contributed to student persistence in scientific learning. © 2016 by the Society for the Study of Reproduction, Inc.

  16. Influence of alginate impression materials and storage time on surface detail reproduction and dimensional accuracy of stone models.

    Science.gov (United States)

    Guiraldo, Ricardo D; Moreti, Ana F F; Martinelli, Julia; Berger, Sandrine B; Meneghel, Luciana L; Caixeta, Rodrigo V; Sinhoreti, Mário A C

    2015-01-01

    This study compared the surface detail reproduction and dimensional accuracy of stone models obtained from molds prepared using different alginate impression materials (Cavex ColorChange, Hydrogum 5, or Jeltrate Plus) and with different storage times (1, 3, and 5 days) to models from molds that were filled immediately with no storage time. The molds were prepared over a matrix containing 50-μm line, (ISO 1563 standard) under pressure with a perforated metal tray. The molds were removed 2 minutes after loss of sticky consistency and either filled immediately or stored in closed jars at 100% relative humidity and 37°C for 1, 3, or 5 days. The molds were filled with dental plaster (Durone IV). Surface detail reproduction and dimensional accuracy were evaluated using optical microscopy on the 50-μm wide line, which was 25 mm in length, according to ISO 1563 standard. The dimensional accuracy results (%) were subjected to analysis of variance. The 50-μm wide line (ISO 1563 standard) was completely reproduced by all alginate impression materials regardless of the storage time. There was no statistically significant difference in the mean dimensional accuracy values of stone models made from molds composed of different alginate impression materials and with different storage times (p = 0.989). In conclusion, storing the mold for five days prior to filling did not change the surface detail reproduction or dimensional accuracy of the alginates examined in this study.

  17. An Instructional Model for Teaching Proof Writing in the Number Theory Classroom

    Science.gov (United States)

    Schabel, Carmen

    2005-01-01

    I discuss an instructional model that I have used in my number theory classes. Facets of the model include using small group work and whole class discussion, having students generate examples and counterexamples, and giving students the opportunity to write proofs and make conjectures in class. The model is designed to actively engage students in…

  18. The Effect of Latitudinal Variation on Shrimp Reproductive Strategies.

    Science.gov (United States)

    van de Kerk, Madelon; Jones Littles, Chanda; Saucedo, Omar; Lorenzen, Kai

    2016-01-01

    Reproductive strategies comprise the timing and frequency of reproductive events and the number of offspring per reproductive event, depending on factors such as climate conditions. Therefore, species that exhibit plasticity in the allocation of reproductive effort can alter their behavior in response to climate change. Studying how the reproductive strategy of species varies along the latitudinal gradient can help us understand and predict how they will respond to climate change. We investigated the effects of the temporal allocation of reproductive effort on the population size of brown shrimp (Farfantepenaeus aztecus) along a latitudinal gradient. Multiple shrimp species exhibit variation in their reproductive strategies, and given the economic importance of brown shrimp to the commercial fishing sector of the Unites States, changes in the timing of their reproduction could have significant economic and social consequences. We used a stage-based, density-dependent matrix population model tailored to the life history of brown shrimp. Shrimp growth rates and environmental carrying capacity were varied based on the seasonal climate conditions at different latitudes, and we estimated the population size at equilibrium. The length of the growing season increased with decreasing latitude and the reproductive strategy leading to the highest population size changed from one annual birth pulse with high reproductive output to continuous low-output reproduction. Hence, our model confirms the classical paradigm of continuous reproduction at low latitudes, with increased seasonality of the breeding period towards the poles. Our results also demonstrate the potential for variation in climate to affect the optimal reproductive strategy for achieving maximum population sizes. Certainly, understanding these dynamics may inform more comprehensive management strategies for commercially important species like brown shrimp.

  19. Baryon-number generation in supersymmetric unified models: the effect of supermassive fermions

    International Nuclear Information System (INIS)

    Kolb, E.W.; Raby, S.

    1983-01-01

    In supersymmetric unified models, baryon-number-violating reactions may be mediated by supermassive fermions in addition to the usual supermassive bosons. The effective low-energy baryon-number-violating cross section for fermion-mediated reactions is sigma/sub DeltaB/approx.g 4 /m 2 , where g is a coupling constant and m is the supermassive fermion mass, as opposed to sigma/sub DeltaB/approx.g 4 s/m 4 for scalar- or vector-mediated reactions (√s is the center-of-mass energy). Since the fermion-mediated cross section is larger at low energy, it is more effective at damping the baryon number produced in decay of the supermassive particles. In this paper we calculate baryon-number generation in models with fermion-mediated baryon-number-violating reactions, and discuss implications for supersymmetric model building

  20. Refined open intersection numbers and the Kontsevich-Penner matrix model

    International Nuclear Information System (INIS)

    Alexandrov, Alexander; Buryak, Alexandr; Tessler, Ran J.

    2017-01-01

    A study of the intersection theory on the moduli space of Riemann surfaces with boundary was recently initiated in a work of R. Pandharipande, J.P. Solomon and the third author, where they introduced open intersection numbers in genus 0. Their construction was later generalized to all genera by J.P. Solomon and the third author. In this paper we consider a refinement of the open intersection numbers by distinguishing contributions from surfaces with different numbers of boundary components, and we calculate all these numbers. We then construct a matrix model for the generating series of the refined open intersection numbers and conjecture that it is equivalent to the Kontsevich-Penner matrix model. An evidence for the conjecture is presented. Another refinement of the open intersection numbers, which describes the distribution of the boundary marked points on the boundary components, is also discussed.

  1. Refined open intersection numbers and the Kontsevich-Penner matrix model

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrov, Alexander [Center for Geometry and Physics, Institute for Basic Science (IBS),Pohang 37673 (Korea, Republic of); Centre de Recherches Mathématiques (CRM), Université de Montréal,Montréal (Canada); Department of Mathematics and Statistics, Concordia University,Montréal (Canada); Institute for Theoretical and Experimental Physics (ITEP),Moscow (Russian Federation); Buryak, Alexandr [Department of Mathematics, ETH Zurich, Zurich (Switzerland); Tessler, Ran J. [Institute for Theoretical Studies, ETH Zurich,Zurich (Switzerland)

    2017-03-23

    A study of the intersection theory on the moduli space of Riemann surfaces with boundary was recently initiated in a work of R. Pandharipande, J.P. Solomon and the third author, where they introduced open intersection numbers in genus 0. Their construction was later generalized to all genera by J.P. Solomon and the third author. In this paper we consider a refinement of the open intersection numbers by distinguishing contributions from surfaces with different numbers of boundary components, and we calculate all these numbers. We then construct a matrix model for the generating series of the refined open intersection numbers and conjecture that it is equivalent to the Kontsevich-Penner matrix model. An evidence for the conjecture is presented. Another refinement of the open intersection numbers, which describes the distribution of the boundary marked points on the boundary components, is also discussed.

  2. Numerical modeling of the impact of regenerator housing on the determination of Nusselt numbers

    DEFF Research Database (Denmark)

    Nielsen, Kaspar Kirstein; Nellis, G.F.; Klein, S.A.

    2013-01-01

    It is suggested that the housing of regenerators may have a significant impact when experimentally determining Nusselt numbers at low Reynolds and large Prandtl numbers. In this paper, a numerical model that takes the regenerator housing into account as a domain that is thermally coupled to the r...

  3. Prospectus: towards the development of high-fidelity models of wall turbulence at large Reynolds number

    Science.gov (United States)

    Klewicki, J. C.; Chini, G. P.; Gibson, J. F.

    2017-01-01

    Recent and on-going advances in mathematical methods and analysis techniques, coupled with the experimental and computational capacity to capture detailed flow structure at increasingly large Reynolds numbers, afford an unprecedented opportunity to develop realistic models of high Reynolds number turbulent wall-flow dynamics. A distinctive attribute of this new generation of models is their grounding in the Navier–Stokes equations. By adhering to this challenging constraint, high-fidelity models ultimately can be developed that not only predict flow properties at high Reynolds numbers, but that possess a mathematical structure that faithfully captures the underlying flow physics. These first-principles models are needed, for example, to reliably manipulate flow behaviours at extreme Reynolds numbers. This theme issue of Philosophical Transactions of the Royal Society A provides a selection of contributions from the community of researchers who are working towards the development of such models. Broadly speaking, the research topics represented herein report on dynamical structure, mechanisms and transport; scale interactions and self-similarity; model reductions that restrict nonlinear interactions; and modern asymptotic theories. In this prospectus, the challenges associated with modelling turbulent wall-flows at large Reynolds numbers are briefly outlined, and the connections between the contributing papers are highlighted. This article is part of the themed issue ‘Toward the development of high-fidelity models of wall turbulence at large Reynolds number’. PMID:28167585

  4. Dynamic model of cage induction motor with number of rotor bars as parameter

    Directory of Open Access Journals (Sweden)

    Gojko Joksimović

    2017-05-01

    Full Text Available A dynamic mathematical model, using number of rotor bars as parameter, is reached for cage induction motors through the use of coupled-circuits and the concept of winding functions. The exact MMFs waveforms are accounted for by the model which is derived in natural frames of reference. By knowing the initial motor parameters for a priori adopted number of stator slots and rotor bars model allows change of rotor bars number what results in new model parameters. During this process, the rated machine power, number of stator slots and stator winding scheme remain the same. Although presented model has a potentially broad application area it is primarily suitable for the analysis of the different stator/rotor slot combination on motor behaviour during the transients or in steady-state regime. The model is significant in its potential to provide analysis of dozen of different number of rotor bars in a few tens of minutes. Numerical example on cage rotor induction motor exemplifies this application, including three variants of number of rotor bars.

  5. A POD reduced order unstructured mesh ocean modelling method for moderate Reynolds number flows

    Science.gov (United States)

    Fang, F.; Pain, C. C.; Navon, I. M.; Gorman, G. J.; Piggott, M. D.; Allison, P. A.; Farrell, P. E.; Goddard, A. J. H.

    Herein a new approach to enhance the accuracy of a novel Proper Orthogonal Decomposition (POD) model applied to moderate Reynolds number flows (of the type typically encountered in ocean models) is presented. This approach develops the POD model of Fang et al. [Fang, F., Pain, C.C., Navon, I.M., Piggott, M.D., Gorman, G.J., Allison, P., Goddard, A.J.H., 2008. Reduced-order modelling of an adaptive mesh ocean model. International Journal for Numerical Methods in Fluids. doi:10.1002/fld.1841] used in conjunction with the Imperial College Ocean Model (ICOM), an adaptive, non-hydrostatic finite element model. Both the velocity and vorticity results of the POD reduced order model (ROM) exhibit an overall good agreement with those obtained from the full model. The accuracy of the POD-Galerkin model with the use of adaptive meshes is first evaluated using the Munk gyre flow test case with Reynolds numbers ranging between 400 and 2000. POD models using the L2 norm become oscillatory when the Reynolds number exceeds Re=400. This is because the low-order truncation of the POD basis inhibits generally all the transfers between the large and the small (unresolved) scales of the fluid flow. Accuracy is improved by using the H1 POD projector in preference to the L2 POD projector. The POD bases are constructed by incorporating gradients as well as function values in the H1 Sobolev norm. The accuracy of numerical results is further enhanced by increasing the number of snapshots and POD bases. Error estimation was used to assess the effect of truncation (involved in the POD-Galerkin approach) when adaptive meshes are used in conjunction with POD/ROM. The RMSE of velocity results between the full model and POD-Galerkin model is reduced by as much as 50% by using the H1 norm and increasing the number of snapshots and POD bases.

  6. Reproductive Hazards

    Science.gov (United States)

    ... and the ability to have children. Something that affects reproductive health is called a reproductive hazard. Examples include: Radiation Metals such as lead and mercury Chemicals such as pesticides Cigarettes Some viruses Alcohol For men, a reproductive hazard can affect the ...

  7. Modelling predicts that tolerance to drought during reproductive development will be required for high yield potential and stability of wheat in Europe

    Science.gov (United States)

    Semenov, Mikhail A.; Stratonovitch, Pierre; Paul, Matthew J.

    2017-04-01

    Short periods of extreme weather, such as a spell of high temperature or drought during a sensitive stage of development, could result in substantial yield losses due to reduction in grain number and grain size. In a modelling study (Stratonovitch & Semenov 2015), heat tolerance around flowering in wheat was identified as a key trait for increased yield potential in Europe under climate change. Ji et all (Ji et al. 2010) demonstrated cultivar specific responses of yield to drought stress around flowering in wheat. They hypothesised that carbohydrate supply to anthers may be the key in maintaining pollen fertility and grain number in wheat. It was shown in (Nuccio et al. 2015) that genetically modified varieties of maize that increase the concentration of sucrose in ear spikelets, performed better under non-drought and drought conditions in field experiments. The objective of this modelling study was to assess potential benefits of tolerance to drought during reproductive development for wheat yield potential and yield stability across Europe. We used the Sirius wheat model to optimise wheat ideotypes for 2050 (HadGEM2, RCP8.5) climate scenarios at selected European sites. Eight cultivar parameters were optimised to maximise mean yields, including parameters controlling phenology, canopy growth and water limitation. At those sites where water could be limited, ideotypes sensitive to drought produced substantially lower mean yields and higher yield variability compare with tolerant ideotypes. Therefore, tolerance to drought during reproductive development is likely to be required for wheat cultivars optimised for the future climate in Europe in order to achieve high yield potential and yield stability.

  8. Establishing Reproductive Health Education and Counseling in Military Services: The Turkish Model for Male Involvement

    Directory of Open Access Journals (Sweden)

    Anne Brigitte Albrectsen

    2008-04-01

    Full Text Available Ministry of Health, Mother and Child Health and Family Planning General Directorate; Turkey Field Office of UNFPA, and Gulhane Military Medical Academy (GMMA of Turkish Armed Forces have been conducting a program to increase male concern and participation in sexual and reproductive health in a positive and supporting way. Specialist physicians and nurses from military hospitals were trained by Ministry of Health as trainers (October 2002- September 2003 by one-week courses on interactive training skills. Primary physicians, nurses and medical petty officers were trained as field trainers and counselors (March 2003-April 2004. Training rooms with standardized training material were established in all of the military garrisons. Soldiers were given the one-day participatory course. Trained medical staff also provided individual counseling and services. All training rooms were coded and connected to Reproductive Health Network established within the Intranet of Army. Reproductive Health activities were included in the regular supervision scheme of the army. Since April 2004 740.000 soldiers were given the one-day course. A total of 4000 military medical staff was educated as Trainers. A total of 580 training rooms were established. Twenty of Military Hospitals became a center of reproductive health training and service delivery. Since large-scale intervention is necessary to reach male population, the army seems to be the best possible venue in Turkey. [TAF Prev Med Bull 2008; 7(2.000: 97-106

  9. The African catfish, Clarias gariepinus, a model for the study of reproductive endocrinology in teleosts

    NARCIS (Netherlands)

    Oordt, P.G.W.J. van; Goos, H.J.Th.

    1987-01-01

    In their natural habitat African catfish, Clarias gariepinus, show a discontinuous reproductive cycle. This cycle follows changes in the gonadotropic activity of the pituitary. Gonadotropin release has been shown to be under dual hypothalamic control, i.e. a gonadotropin-releasing hormone (GnRH) and

  10. Multiscale Systems Modeling of Male Reproductive Tract Defects: from Genes to Populations (SOT)

    Science.gov (United States)

    The reproductive tract is a complex, integrated organ system with diverse embryology and unique sensitivity to prenatal environmental exposures that disrupt morphoregulatory processes and endocrine signaling. U.S. EPA’s in vitro high-throughput screening (HTS) database (ToxCastDB...

  11. Usefulness of bovine and porcine IVM/IVF models for reproductive toxicology

    NARCIS (Netherlands)

    Santos, Regiane R; Schoevers, Eric J; Roelen, Bernard Aj

    2014-01-01

    Women presenting fertility problems are often helped by Assisted Reproductive Techniques (ART), such as in vitro fertilization (IVF) programs. However, in many cases the etiology of the in/subfertility remains unknown even after treatment. Although several aspects should be considered when assisting

  12. Pierre Bourdieu's Model of Cultural Reproduction: The Role of Teachers in Sustaining Traditional Power Systems

    Science.gov (United States)

    Savage, Lawrence E.

    2011-01-01

    The purpose of this study was to determine whether or not teachers would predict differing educational outcomes for students based on cultural and social capital measures--drawn from the work of Pierre Bourdieu and the field of cultural reproduction theory. To this end, surveys were distributed within a large urban district within North Carolina.…

  13. Application of random number generators in genetic algorithms to improve rainfall-runoff modelling

    Science.gov (United States)

    Chlumecký, Martin; Buchtele, Josef; Richta, Karel

    2017-10-01

    The efficient calibration of rainfall-runoff models is a difficult issue, even for experienced hydrologists. Therefore, fast and high-quality model calibration is a valuable improvement. This paper describes a novel methodology and software for the optimisation of a rainfall-runoff modelling using a genetic algorithm (GA) with a newly prepared concept of a random number generator (HRNG), which is the core of the optimisation. The GA estimates model parameters using evolutionary principles, which requires a quality number generator. The new HRNG generates random numbers based on hydrological information and it provides better numbers compared to pure software generators. The GA enhances the model calibration very well and the goal is to optimise the calibration of the model with a minimum of user interaction. This article focuses on improving the internal structure of the GA, which is shielded from the user. The results that we obtained indicate that the HRNG provides a stable trend in the output quality of the model, despite various configurations of the GA. In contrast to previous research, the HRNG speeds up the calibration of the model and offers an improvement of rainfall-runoff modelling.

  14. Prediction Model of Interval Grey Numbers with a Real Parameter and Its Application

    Directory of Open Access Journals (Sweden)

    Bo Zeng

    2014-01-01

    Full Text Available Grey prediction models have become common methods which are widely employed to solve the problems with “small examples and poor information.” However, modeling objects of existing grey prediction models are limited to the homogenous data sequences which only contain the same data type. This paper studies the methodology of building prediction models of interval grey numbers that are grey heterogeneous data sequence, with a real parameter. Firstly, the position of the real parameter in an interval grey number sequence is discussed, and the real number is expanded into an interval grey number by adopting the method of grey generation. On this basis, a prediction model of interval grey number with a real parameter is deduced and built. Finally, this novel model is successfully applied to forecast the concentration of organic pollutant DDT in the atmosphere. The analysis and research results in this paper extend the object of grey prediction from homogenous data sequence to grey heterogeneous data sequence. Those research findings are of positive significance in terms of enriching and improving the theory system of grey prediction models.

  15. Low Mach and Peclet number limit for a model of stellar tachocline and upper radiative zones

    Directory of Open Access Journals (Sweden)

    Donatella Donatelli

    2016-09-01

    Full Text Available We study a hydrodynamical model describing the motion of internal stellar layers based on compressible Navier-Stokes-Fourier-Poisson system. We suppose that the medium is electrically charged, we include energy exchanges through radiative transfer and we assume that the system is rotating. We analyze the singular limit of this system when the Mach number, the Alfven number, the Peclet number and the Froude number approache zero in a certain way and prove convergence to a 3D incompressible MHD system with a stationary linear transport equation for transport of radiation intensity. Finally, we show that the energy equation reduces to a steady equation for the temperature corrector.

  16. The effect of reproductive performance on the dairy cattle herd value assessed by integrating a daily dynamic programming model with a daily Markov chain model.

    Science.gov (United States)

    Kalantari, A S; Cabrera, V E

    2012-10-01

    The objective of this study was to determine the effect of reproductive performance on dairy cattle herd value. Herd value was defined as the herd's average retention payoff (RPO). Individual cow RPO is the expected profit from keeping the cow compared with immediate replacement. First, a daily dynamic programming model was developed to calculate the RPO of all cow states in a herd. Second, a daily Markov chain model was applied to estimate the herd demographics. Finally, the herd value was calculated by aggregating the RPO of all cows in the herd. Cow states were described by 5 milk yield classes (76, 88, 100, 112, and 124% with respect to the average), 9 lactations, 750 d in milk, and 282 d in pregnancy. Five different reproductive programs were studied (RP1 to RP5). Reproductive program 1 used 100% timed artificial insemination (TAI; 42% conception rate for first TAI and 30% for second and later services) and the other programs combined TAI with estrus detection. The proportion of cows receiving artificial insemination after estrus detection ranged from 30 to 80%, and conception rate ranged from 25 to 35%. These 5 reproductive programs were categorized according to their 21-d pregnancy rate (21-d PR), which is an indication of the rate that eligible cows become pregnant every 21 d. The 21-d PR was 17% for RP1, 14% for RP2, 16% for RP3, 18% for RP4, and 20% for RP5. Results showed a positive relationship between 21-d PR and herd value. The most extreme herd value difference between 2 reproductive programs was $77/cow per yr for average milk yield (RP5 - RP2), $13/cow per yr for lowest milk yield (RP5 - RP1), and $160/cow per yr for highest milk yield (RP5 - RP2). Reproductive programs were ranked based on their calculated herd value. With the exception of the best reproductive program (RP5), all other programs showed some level of ranking change according to milk yield. The most dramatic ranking change was observed in RP1, which moved from being the worst ranked

  17. Reproductive sharing among queens in the ant Formica fusca

    OpenAIRE

    Minttumaaria Hannonen; Liselotte Sundstro¨m

    2003-01-01

    Reproductive sharing among cobreeders, in which reproductive shares may vary from equal contribution (low reproductive skew) to reproductive dominance by one individual (high reproductive skew), is a fundamental feature of animal societies. Recent theoretical work, the reproductive skew models, has focused on factors affecting the degree to which reproduction is skewed within a society. We used the parameters provided by skew models as a guideline to study determinants of reproductive sharing...

  18. Baryon number fluctuations and the phase structure in the PNJL model

    Science.gov (United States)

    Shao, Guo-yun; Tang, Zhan-duo; Gao, Xue-yan; He, Wei-bo

    2018-02-01

    We investigate the kurtosis and skewness of net-baryon number fluctuations in the Polyakov loop extended Nambu-Jona-Lasinio (PNJL) model, and discuss the relations between fluctuation distributions and the phase structure of quark-gluon matter. The calculation shows that the traces of chiral and deconfinement transitions can be effectively reflected by the kurtosis and skewness of net-baryon number fluctuations not only in the critical region but also in the crossover region. The contour plot of baryon number kurtosis derived in the PNJL model can qualitatively explain the behavior of net-proton number kurtosis in the STAR beam energy scan experiments. Moreover, the three-dimensional presentations of the kurtosis and skewness in this study are helpful to understand the relations between baryon number fluctuations and QCD phase structure.

  19. Model for modulated and chaotic waves in zero-Prandtl-number ...

    Indian Academy of Sciences (India)

    The effects of time-periodic forcing in a few-mode model for zero-Prandtl-number convection with rigid body rotation is investigated. The time-periodic modulation of the rotation rate about the vertical axis and gravity modulation are considered separately. In the presence of periodic variation of the rotation rate, the model ...

  20. 438 Optimal Number of States in Hidden Markov Models and its ...

    African Journals Online (AJOL)

    In this paper, Hidden Markov Model is applied to model human movements as to facilitate an automatic detection of the same. A number of activities were simulated with the help of two persons. The four movements considered are walking, sitting down-getting up, fall while walking and fall while standing. The.

  1. Unsuppressed fermion-number violation at high temperature: An O(3) model

    International Nuclear Information System (INIS)

    Mottola, E.; Wipf, A.

    1989-01-01

    The O(3) nonlinear σ model in 1+1 dimensions, modified by an explicit symmetry-breaking term, is presented as a model for baryon- and lepton-number violation in the standard electroweak theory. Although arguments based on the Atiyah-Singer index theorem and instanton physics apply to the model, we show by explicit calculations that the rate of chiral fermion-number violation due to the axial anomaly is entirely unsuppressed at sufficiently high temperatures. Our results apply to unbroken gauge theories as well and may require reevaluation of the role of instantons in high-temperature QCD

  2. A pollution fate and transport model application in a semi-arid region: Is some number better than no number?

    Science.gov (United States)

    Özcan, Zeynep; Başkan, Oğuz; Düzgün, H Şebnem; Kentel, Elçin; Alp, Emre

    2017-10-01

    Fate and transport models are powerful tools that aid authorities in making unbiased decisions for developing sustainable management strategies. Application of pollution fate and transport models in semi-arid regions has been challenging because of unique hydrological characteristics and limited data availability. Significant temporal and spatial variability in rainfall events, complex interactions between soil, vegetation and topography, and limited water quality and hydrological data due to insufficient monitoring network make it a difficult task to develop reliable models in semi-arid regions. The performances of these models govern the final use of the outcomes such as policy implementation, screening, economical analysis, etc. In this study, a deterministic distributed fate and transport model, SWAT, is applied in Lake Mogan Watershed, a semi-arid region dominated by dry agricultural practices, to estimate nutrient loads and to develop the water budget of the watershed. To minimize the discrepancy due to limited availability of historical water quality data extensive efforts were placed in collecting site-specific data for model inputs such as soil properties, agricultural practice information and land use. Moreover, calibration parameter ranges suggested in the literature are utilized during calibration in order to obtain more realistic representation of Lake Mogan Watershed in the model. Model performance is evaluated using comparisons of the measured data with 95%CI for the simulated data and comparison of unit pollution load estimations with those provided in the literature for similar catchments, in addition to commonly used evaluation criteria such as Nash-Sutcliffe simulation efficiency, coefficient of determination and percent bias. These evaluations demonstrated that even though the model prediction power is not high according to the commonly used model performance criteria, the calibrated model may provide useful information in the comparison of the

  3. A cognitive model for multidigit number reading: Inferences from individuals with selective impairments.

    Science.gov (United States)

    Dotan, Dror; Friedmann, Naama

    2018-04-01

    We propose a detailed cognitive model of multi-digit number reading. The model postulates separate processes for visual analysis of the digit string and for oral production of the verbal number. Within visual analysis, separate sub-processes encode the digit identities and the digit order, and additional sub-processes encode the number's decimal structure: its length, the positions of 0, and the way it is parsed into triplets (e.g., 314987 → 314,987). Verbal production consists of a process that generates the verbal structure of the number, and another process that retrieves the phonological forms of each number word. The verbal number structure is first encoded in a tree-like structure, similarly to syntactic trees of sentences, and then linearized to a sequence of number-word specifiers. This model is based on an investigation of the number processing abilities of seven individuals with different selective deficits in number reading. We report participants with impairment in specific sub-processes of the visual analysis of digit strings - in encoding the digit order, in encoding the number length, or in parsing the digit string to triplets. Other participants were impaired in verbal production, making errors in the number structure (shifts of digits to another decimal position, e.g., 3,040 → 30,004). Their selective deficits yielded several dissociations: first, we found a double dissociation between visual analysis deficits and verbal production deficits. Second, several dissociations were found within visual analysis: a double dissociation between errors in digit order and errors in the number length; a dissociation between order/length errors and errors in parsing the digit string into triplets; and a dissociation between the processing of different digits - impaired order encoding of the digits 2-9, without errors in the 0 position. Third, within verbal production, a dissociation was found between digit shifts and substitutions of number words. A

  4. Modelling the fluid mechanics of cilia and flagella in reproduction and development.

    Science.gov (United States)

    Montenegro-Johnson, Thomas D; Smith, Andrew A; Smith, David J; Loghin, Daniel; Blake, John R

    2012-10-01

    Cilia and flagella are actively bending slender organelles, performing functions such as motility, feeding and embryonic symmetry breaking. We review the mechanics of viscous-dominated microscale flow, including time-reversal symmetry, drag anisotropy of slender bodies, and wall effects. We focus on the fundamental force singularity, higher-order multipoles, and the method of images, providing physical insight and forming a basis for computational approaches. Two biological problems are then considered in more detail: 1) left-right symmetry breaking flow in the node, a microscopic structure in developing vertebrate embryos, and 2) motility of microswimmers through non-Newtonian fluids. Our model of the embryonic node reveals how particle transport associated with morphogenesis is modulated by the gradual emergence of cilium posterior tilt. Our model of swimming makes use of force distributions within a body-conforming finite-element framework, allowing the solution of nonlinear inertialess Carreau flow. We find that a three-sphere model swimmer and a model sperm are similarly affected by shear-thinning; in both cases swimming due to a prescribed beat is enhanced by shear-thinning, with optimal Deborah number around 0.8. The sperm exhibits an almost perfect linear relationship between velocity and the logarithm of the ratio of zero to infinite shear viscosity, with shear-thickening hindering cell progress.

  5. Effects of calcium propionate by different numbers of applications in first week postpartum of dairy cows on hypocalcemia, milk production and reproductive disorders

    Directory of Open Access Journals (Sweden)

    Arda Kovanlıkaya

    2010-01-01

    Full Text Available This study was conducted to evaluate effects of calcium propionate on hypocalcemia, dry matter intake, body condition score, milk production and reproductive disorders in dairy cows. Twenty four multiparous Holstein cows were sorted by parity, body condition score (BCS in close-up period and season of calving and assigned to one of the three treatments. The cows in treatment 1 (T1 received two drenches at calving and 24h after calving. The cows in treatment 2 (T2 received three drenches at calving, 24h after calving and 7 days after calving. The cows in treatment 3 (T3 were the control. Each drench contained 143g of calcium as calcium propionate (0.68kg. Parameters studied were serum calcium, glucose and nonesterified fatty acid (NEFA concentrations, dry matter intake (DMI, BCS, milk production (MP, incidence of retained placenta (RP and metritis. Milk fever developed in 5 of 8 cows, in 3 of 8 cows and in 3 of 8 cows in T1, T2 and T3, respectively, at calving. There was no cow with milk fever in T1 and T2 at 4h after second drench (about 28h after calving but 3 of 8 cows in T3 had still milk fever at this time. The cows receiving two drenches recovered from milk fever in a shorter term as compared to the cows in T3. There were no differences among treatments for DMI, BCS, MP, RP, serum glucose and NEFA concentrations during the experimental period. There was no difference for metritis between T1 and T3 but incidence of metritis in T2 was significantly lower as compared to T3 (P<0.05. Two drenches of calcium propionate were beneficial in treating milk fever and three drenches of calcium propionate were considered to have had a preventive effect for metritis.

  6. The Influence of the Number of Different Stocks on the Levy-Levy-Solomon Model

    Science.gov (United States)

    Kohl, R.

    The stock market model of Levy, Levy, Solomon is simulated for more than one stock to analyze the behavior for a large number of investors. Small markets can lead to realistic looking prices for one and more stocks. A large number of investors leads to a semi-regular fashion simulating one stock. For many stocks, three of the stocks are semi-regular and dominant, the rest is chaotic. Aside from that we changed the utility function and checked the results.

  7. [Prediction model of meteorological grade of wheat stripe rust in winter-reproductive area, Sichuan Basin, China].

    Science.gov (United States)

    Guo, Xiang; Wang, Ming Tian; Zhang, Guo Zhi

    2017-12-01

    The winter reproductive areas of Puccinia striiformis var. striiformis in Sichuan Basin are often the places mostly affected by wheat stripe rust. With data on the meteorological condition and stripe rust situation at typical stations in the winter reproductive area in Sichuan Basin from 1999 to 2016, this paper classified the meteorological conditions inducing wheat stripe rust into 5 grades, based on the incidence area ratio of the disease. The meteorological factors which were biologically related to wheat stripe rust were determined through multiple analytical methods, and a meteorological grade model for forecasting wheat stripe rust was created. The result showed that wheat stripe rust in Sichuan Basin was significantly correlated with many meteorological factors, such as the ave-rage (maximum and minimum) temperature, precipitation and its anomaly percentage, relative humidity and its anomaly percentage, average wind speed and sunshine duration. Among these, the average temperature and the anomaly percentage of relative humidity were the determining factors. According to a historical retrospective test, the accuracy of the forecast based on the model was 64% for samples in the county-level test, and 89% for samples in the municipal-level test. In a meteorological grade forecast of wheat stripe rust in the winter reproductive areas in Sichuan Basin in 2017, the prediction was accurate for 62.8% of the samples, with 27.9% error by one grade and only 9.3% error by two or more grades. As a result, the model could deliver satisfactory forecast results, and predicate future wheat stripe rust from a meteorological point of view.

  8. Prediction of the lifetime productive and reproductive performance of Holstein cows managed for different lactation durations, using a model of lifetime nutrient partitioning

    DEFF Research Database (Denmark)

    Gaillard, Charlotte; Martin, O; Blavy, P

    2016-01-01

    The GARUNS model is a lifetime performance model taking into account the changing physiological priorities of an animal during its life and through repeated reproduction cycles. This dynamic and stochastic model has been previously used to predict the productive and reproductive performance...... of various genotypes of cows across feeding systems. In the present paper, we used this model to predict the lifetime productive and reproductive performance of Holstein cows for different lactation durations, with the aim of determining the lifetime scenario that optimizes cows' performance defined...... by lifetime efficiency (ratio of total milk energy yield to total energy intake) and pregnancy rate. To evaluate the model, data from a 16-mo extended lactation experiment on Holstein cows were used. Generally, the model could consistently fit body weight, milk yield, and milk components of these cows...

  9. Randomized evaluation and cost-effectiveness of HIV and sexual and reproductive health service referral and linkage models in Zambia

    Directory of Open Access Journals (Sweden)

    Paul C. Hewett

    2016-08-01

    Full Text Available Abstract Background Provision of HIV prevention and sexual and reproductive health services in Zambia is largely characterized by discrete service provision with weak client referral and linkage. The literature reveals gaps in the continuity of care for HIV and sexual and reproductive health. This study assessed whether improved service delivery models increased the uptake and cost-effectiveness of HIV and sexual and reproductive health services. Methods Adult clients 18+ years of age accessing family planning (females, HIV testing and counseling (females and males, and male circumcision services (males were recruited, enrolled and individually randomized to one of three study arms: 1 the standard model of service provision at the entry point (N = 1319; 2 an enhanced counseling and referral to add-on service with follow-up (N = 1323; and 3 the components of study arm two, with the additional offer of an escort (N = 1321. Interviews were conducted with the same clients at baseline, six weeks and six months. Uptake of services for HIV, family planning, male circumcision, and cervical cancer screening at six weeks and six months were the primary endpoints. Pairwise chi-square and multivariable logistic regression statistical tests assessed differences across study arms, which were also assessed for incremental cost-efficiency and cost-effectiveness. Results A total of 3963 clients, 1920 males and 2043 females, were enrolled; 82 % of participants at six weeks were tracked and 81 % at six months; follow-up rates did not vary significantly by study arm. The odds of clients accessing HIV testing and counseling, cervical cancer screening services among females, and circumcision services among males varied significantly by study arm at six weeks and six months; less consistent findings were observed for HIV care and treatment. Client uptake of family planning services did not vary significantly by study arm. Integrated services were found

  10. The importance of modeling nonhydrostatic processes for dense water reproduction in the Southern Adriatic Sea

    Science.gov (United States)

    Bellafiore, Debora; McKiver, William J.; Ferrarin, Christian; Umgiesser, Georg

    2018-05-01

    Dense water (DW) formation commonly occurs in the shallow Northern Adriatic Sea during winter outbreaks, when there is a combination of the cooling of surface waters by the winds and high salinity as a result of reduced river inputs. These DWs subsequently propagate southwards over a period of weeks/months, eventually arriving in the Southern Adriatic Sea. The investigation is based on a new nonhydrostatic (NH) formulation of the 3D finite element model SHYFEM that is validated for a number of theoretical test cases. Subsequently this model is used to simulate, through high-resolution numerical simulations, an extreme DW event that occurred in the Adriatic Sea in 2012. We perform both hydrostatic (HY) and NH simulations in order to explicitly see the impact of NH processes on the DW dynamics. The modeled results are compared to observations collected in the field campaign of March-April 2012 in the Southern Adriatic Sea. The NH run correctly reproduces the across isobath bottom-trapped gravity current characterizing the canyon DW pathways. It also more accurately captures the frequency and intensity of dense water cascading pulsing events, as the inclusion of NH processes produces stronger currents with different DW mixing characteristics. Finally, the NH run simulates internal gravity waves (IGW), generated during the cascading at the edge of the canyon, which propagate downslope. This IGW activity is not captured in the HY case.

  11. Particle-number-projected Hartree-Fock-Bogoliubov study with effective shell model interactions

    Science.gov (United States)

    Maqbool, I.; Sheikh, J. A.; Ganai, P. A.; Ring, P.

    2011-04-01

    We perform the particle-number-projected mean-field study using the recently developed symmetry-projected Hartree-Fock-Bogoliubov (HFB) equations. Realistic calculations have been performed in sd- and fp-shell nuclei using the shell model empirical interactions, USD and GXPFIA. It is demonstrated that the mean-field results for energy surfaces, obtained with these shell model interactions, are quite similar to those obtained using the density functional approaches. Further, it is shown that particle-number-projected results, for neutron-rich isotopes, can lead to different ground-state shapes in comparison to bare HFB calculations.

  12. Comparison of models for genetic evaluation of number of inseminations to conception in Danish Holstein cows.

    Science.gov (United States)

    Guo, Gang; Hou, Yali; Zhang, Yuan; Su, Guosheng

    2017-04-01

    Number of inseminations to conception (NINS), an important fertility trait, requires appropriate approaches for genetic evaluation due to its non-normal distribution and censoring records. In this study, we analyzed NINS in 474 837 Danish Holstein cows at their first lactation by using seven models which deal with the categorical phenotypes and censored records in different manners, further assessed these models with regard to stability, lack of bias and accuracy of prediction. The estimated heritability from four models based on original NINS specified as a linear Gaussian model, categorical threshold model, threshold linear model and survival model were similar (0.031-0.037). While for the other three models based on the binary response derived from NINS, referred as threshold model (TM), logistic and probit models (LOGM and PROM), the heritability were estimated as 0.027, 0.063 and 0.027, respectively. The model comparison concluded that different models could lead to slightly different sire rankings in terms of breeding values; a more complicated model led to less stability of prediction; the models based on the binary response derived from NINS (TM, LOGM and PROM) had slightly better performances in terms of unbiased and accurate prediction of breeding values. © 2016 Japanese Society of Animal Science.

  13. Development of a Statistical Model for Seasonal Prediction of North Atlantic Hurricane Numbers

    Science.gov (United States)

    Davis, K.; Zeng, X.

    2014-12-01

    Tropical cyclones cause more financial distress to insurance companies than any other natural disaster. From 1970-2002, it is estimated that hurricanes caused 44 billion dollars in damage, greater than 2.5 times the the next costliest catastrophe. Theses damages do not go without effect. A string of major catastrophes from 1991-1994 caused nine property firms to bankrupt and caused serious financial strain on others. The public was not only affected by the loss of life and property, but the increase in tax dollars for disaster relief. Providing better seasonal predictions of North Atlantic hurricane activity farther in advance will help alleviate some of the financial strains these major catastrophes put on the nation. A statistical model was first developed by Bill Gray's team to predict the total number of hurricanes over the North Atlantic in 1984, followed by other statistical methods, dynamic modeling, and hybrid methods in recent years. However, all these methods showed little to no skill with forecasts made by June 1 in recent years. In contrast to the relatively small year-to-year change in seasonal hurricane numbers pre-1980, there has been much greater interannual changes since, especially since the year 2000. For instance, while there were very high hurricane numbers in 2005 and 2010, 2013 was one of the lowest in history. Recognizing these interdecadal changes in the dispersion of hurricane numbers, we have developed a new statistical model to more realistically predict (by June 1 each year) the seasonal hurricane number over the North Atlantic. It is based on the Multivariate ENSO Index (MEI) conditioned by the Atlantic Multidecadal Oscillation (AMO) index, the zonal wind stress and sea surface temperature over the Atlantic. It provides both the deterministic number and the range of hurricane numbers. The details of the model and its performance from 1950-2014 in comparison with other methods will be presented in our presentation.

  14. Reproductive emergencies.

    Science.gov (United States)

    Jutkowitz, L Ari

    2005-03-01

    The emergency clinician is frequently called on to manage problems relating to the female reproductive tract. Because owners sel-dom have the medical knowledge needed to differentiate normal from abnormal reproductive behaviors, they frequently look to the emergency veterinarian for guidance and information during and after parturition. For this reason, it is essential that the veterinarian have a good understanding of the normal reproductive cycle as well as the common emergencies that may occur. This article reviews the events surrounding normal parturition in the dog and cat and the reproductive emergencies seen most commonly in practice.

  15. One Model Fits All: Explaining Many Aspects of Number Comparison within a Single Coherent Model-A Random Walk Account

    Science.gov (United States)

    Reike, Dennis; Schwarz, Wolf

    2016-01-01

    The time required to determine the larger of 2 digits decreases with their numerical distance, and, for a given distance, increases with their magnitude (Moyer & Landauer, 1967). One detailed quantitative framework to account for these effects is provided by random walk models. These chronometric models describe how number-related noisy…

  16. PREDICTIVE CAPACITY OF INSOLVENCY MODELS BASED ON ACCOUNTING NUMBERS AND DESCRIPTIVE DATA

    Directory of Open Access Journals (Sweden)

    Rony Petson Santana de Souza

    2012-09-01

    Full Text Available In Brazil, research into models to predict insolvency started in the 1970s, with most authors using discriminant analysis as a statistical tool in their models. In more recent years, authors have increasingly tried to verify whether it is possible to forecast insolvency using descriptive data contained in firms’ reports. This study examines the capacity of some insolvency models to predict the failure of Brazilian companies that have gone bankrupt. The study is descriptive in nature with a quantitative approach, based on research of documents. The sample is omposed of 13 companies that were declared bankrupt between 1997 and 2003. The results indicate that the majority of the insolvency prediction models tested showed high rates of correct forecasts. The models relying on descriptive reports on average were more likely to succeed than those based on accounting figures. These findings demonstrate that although some studies indicate a lack of validity of predictive models created in different business settings, some of these models have good capacity to forecast insolvency in Brazil. We can conclude that both models based on accounting numbers and those relying on descriptive reports can predict the failure of firms. Therefore, it can be inferred that the majority of bankruptcy prediction models that make use of accounting numbers can succeed in predicting the failure of firms.

  17. Modeling both of the number of pausibacillary and multibacillary leprosy patients by using bivariate poisson regression

    Science.gov (United States)

    Winahju, W. S.; Mukarromah, A.; Putri, S.

    2015-03-01

    Leprosy is a chronic infectious disease caused by bacteria of leprosy (Mycobacterium leprae). Leprosy has become an important thing in Indonesia because its morbidity is quite high. Based on WHO data in 2014, in 2012 Indonesia has the highest number of new leprosy patients after India and Brazil with a contribution of 18.994 people (8.7% of the world). This number makes Indonesia automatically placed as the country with the highest number of leprosy morbidity of ASEAN countries. The province that most contributes to the number of leprosy patients in Indonesia is East Java. There are two kind of leprosy. They consist of pausibacillary and multibacillary. The morbidity of multibacillary leprosy is higher than pausibacillary leprosy. This paper will discuss modeling both of the number of multibacillary and pausibacillary leprosy patients as responses variables. These responses are count variables, so modeling will be conducted by using bivariate poisson regression method. Unit experiment used is in East Java, and predictors involved are: environment, demography, and poverty. The model uses data in 2012, and the result indicates that all predictors influence significantly.

  18. A Comparison of Three Random Number Generators for Aircraft Dynamic Modeling Applications

    Science.gov (United States)

    Grauer, Jared A.

    2017-01-01

    Three random number generators, which produce Gaussian white noise sequences, were compared to assess their suitability in aircraft dynamic modeling applications. The first generator considered was the MATLAB (registered) implementation of the Mersenne-Twister algorithm. The second generator was a website called Random.org, which processes atmospheric noise measured using radios to create the random numbers. The third generator was based on synthesis of the Fourier series, where the random number sequences are constructed from prescribed amplitude and phase spectra. A total of 200 sequences, each having 601 random numbers, for each generator were collected and analyzed in terms of the mean, variance, normality, autocorrelation, and power spectral density. These sequences were then applied to two problems in aircraft dynamic modeling, namely estimating stability and control derivatives from simulated onboard sensor data, and simulating flight in atmospheric turbulence. In general, each random number generator had good performance and is well-suited for aircraft dynamic modeling applications. Specific strengths and weaknesses of each generator are discussed. For Monte Carlo simulation, the Fourier synthesis method is recommended because it most accurately and consistently approximated Gaussian white noise and can be implemented with reasonable computational effort.

  19. Probability modeling of the number of positive cores in a prostate cancer biopsy session, with applications.

    Science.gov (United States)

    Serfling, Robert; Ogola, Gerald

    2016-02-10

    Among men, prostate cancer (CaP) is the most common newly diagnosed cancer and the second leading cause of death from cancer. A major issue of very large scale is avoiding both over-treatment and under-treatment of CaP cases. The central challenge is deciding clinical significance or insignificance when the CaP biopsy results are positive but only marginally so. A related concern is deciding how to increase the number of biopsy cores for larger prostates. As a foundation for improved choice of number of cores and improved interpretation of biopsy results, we develop a probability model for the number of positive cores found in a biopsy, given the total number of cores, the volumes of the tumor nodules, and - very importantly - the prostate volume. Also, three applications are carried out: guidelines for the number of cores as a function of prostate volume, decision rules for insignificant versus significant CaP using number of positive cores, and, using prior distributions on total tumor size, Bayesian posterior probabilities for insignificant CaP and posterior median CaP. The model-based results have generality of application, take prostate volume into account, and provide attractive tradeoffs of specificity versus sensitivity. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  20. A new method to determine the number of experimental data using statistical modeling methods

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jung-Ho; Kang, Young-Jin; Lim, O-Kaung; Noh, Yoojeong [Pusan National University, Busan (Korea, Republic of)

    2017-06-15

    For analyzing the statistical performance of physical systems, statistical characteristics of physical parameters such as material properties need to be estimated by collecting experimental data. For accurate statistical modeling, many such experiments may be required, but data are usually quite limited owing to the cost and time constraints of experiments. In this study, a new method for determining a rea- sonable number of experimental data is proposed using an area metric, after obtaining statistical models using the information on the underlying distribution, the Sequential statistical modeling (SSM) approach, and the Kernel density estimation (KDE) approach. The area metric is used as a convergence criterion to determine the necessary and sufficient number of experimental data to be acquired. The pro- posed method is validated in simulations, using different statistical modeling methods, different true models, and different convergence criteria. An example data set with 29 data describing the fatigue strength coefficient of SAE 950X is used for demonstrating the performance of the obtained statistical models that use a pre-determined number of experimental data in predicting the probability of failure for a target fatigue life.

  1. Reproductive strategies in snakes.

    Science.gov (United States)

    Shine, Richard

    2003-05-22

    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.

  2. Diffusion Processes in the A-Model of Vector Admixture: Turbulent Prandtl Number

    Science.gov (United States)

    Jurčišinová, Eva; Jurčišin, Marián; Remecky, Richard

    2018-02-01

    Using analytical approach of the field theoretic renormalization-group technique in two-loop approximation we model a fully developed turbulent system with vector characteristics driven by stochastic Navier-Stokes equation. The behaviour of the turbulent Prandtl number PrA,t is investigated as a function of parameter A and spatial dimension d > 2 for three cases, namely, kinematic MHD turbulence (A = 1), the admixture of a vector impurity by the Navier-Stokes turbulent flow (A = 0) and the model of linearized Navier-Stokes equation (A = -1). It is shown that for A = -1 the turbulent Prandtl number is given already in the one-loop approximation and does not depend on d while turbulent Prandt numbers in first two cases show very similar behaviour as functions of dimension d in the two-loop approximation.

  3. Reduction of the number of parameters needed for a polynomial random regression test-day model

    NARCIS (Netherlands)

    Pool, M.H.; Meuwissen, T.H.E.

    2000-01-01

    Legendre polynomials were used to describe the (co)variance matrix within a random regression test day model. The goodness of fit depended on the polynomial order of fit, i.e., number of parameters to be estimated per animal but is limited by computing capacity. Two aspects: incomplete lactation

  4. Modelling the number of viable vegetative cells of Bacillus cereus passing through the stomach

    NARCIS (Netherlands)

    Wijnands, L.M.; Pielaat, A.; Dufrenne, J.B.; Zwietering, M.H.; Leusden, van F.M.

    2009-01-01

    Aims: Model the number of viable vegetative cells of B. cereus surviving the gastric passage after experiments in simulated gastric conditions. Materials and Methods: The inactivation of stationary and exponential phase vegetative cells of twelve different strains of Bacillus cereus, both mesophilic

  5. Dependence of the number of dealers in a stochastic dealer model

    Science.gov (United States)

    Yamada, Kenta; Takayasu, Hideki; Takayasu, Misako

    2010-04-01

    We numerically analyze an artificial market model consisted of N dealers with time dependent stochastic strategy. Observing the change of market price statistics for different values of N, it is shown that the statistical properties are almost same when the dealer number is larger than about 30.

  6. Representational Flexibility and Problem-Solving Ability in Fraction and Decimal Number Addition: A Structural Model

    Science.gov (United States)

    Deliyianni, Eleni; Gagatsis, Athanasios; Elia, Iliada; Panaoura, Areti

    2016-01-01

    The aim of this study was to propose and validate a structural model in fraction and decimal number addition, which is founded primarily on a synthesis of major theoretical approaches in the field of representations in Mathematics and also on previous research on the learning of fractions and decimals. The study was conducted among 1,701 primary…

  7. Exceptional longevity in female Rottweiler dogs is not encumbered by investment in reproduction.

    Science.gov (United States)

    Kengeri, S S; Maras, A H; Suckow, C L; Chiang, E C; Waters, D J

    2013-12-01

    To better understand the potential trade-off between female reproductive investment and longevity in an emerging model of human healthspan, we studied pet dogs to determine whether intensity of reproduction (total number of offspring) encumbered the likelihood of exceptional longevity. This hypothesis was tested by collecting and analyzing lifetime medical histories, including complete reproductive histories, for a cohort of canine "centenarians"--exceptionally long-lived Rottweiler dogs that lived more than 30% longer than the breed's average life expectancy. Reproductive intensity (number of litters, total number of pups) and tempo of reproductive effort (age at first reproduction, mean interbirth interval, age at last reproduction) in 78 exceptionally long-lived female Rottweilers (>13 years old) were compared to a cohort of 97 female Rottweilers that had usual longevity (age at death 8.0-10.75 years). We found no evidence that a mother's physiological investment in offspring was associated with disadvantaged longevity. Instead, similar to some studies in women, our data showed an inverted U-shaped trend, suggesting that moderate investment in reproduction may promote longevity. Late reproductive success, a much-studied surrogate of maternal fitness in women, was not a strong predictor of longevity in this canine cohort. Instead, independent of reproductive investment, the duration of lifetime ovary exposure was significantly associated with highly successful aging. Our results from exceptionally long-lived pet dogs provide rationale for further investigative efforts to understand the ovary-sensitive biological factors that promote healthy longevity in women and pet dogs.

  8. Daphnia as a model organism in limnology and aquatic biology: some aspects of its reproduction and development

    Directory of Open Access Journals (Sweden)

    Adam Petrusek

    2011-08-01

    Full Text Available Invertebrates comprise the overwhelming majority of all animal species - around 95% of described species, not including substantial cryptic variation. As it is an extremely diverse and heterogeneous group, research on various invertebrate taxa often follows parallel trajectories, with little interaction among experts on different groups. To promote sharing of knowledge within as well as across taxa, the International Society of Invertebrate Reproduction and Development (ISIRD was established in 1975 in Calicut, India. Since that time, the ISIRD has organised international conferences at three-year intervals where various aspects of invertebrate biology are presented and discussed, naturally with the focus on reproduction and development. Traditionally, marine invertebrate groups have been well represented at all ISIRD congresses, but freshwater invertebrates have often been relatively overlooked at these meetings. The 12th ISIRD congress took place between August 16 and 20, 2010 in Prague, the Czech Republic. Several different Czech institutions collaborated on the organisation of this meeting. As aquatic invertebrate research has a long tradition in the country, we decided to include a section dedicated to popular model organisms in aquatic ecology and evolutionary biology, the "water fleas", cladocerans of the genus Daphnia. The section entitled "Daphnia and other cladocerans as model organisms" was open to any aspects of cladoceran biology directly or indirectly related to their reproduction or development. Unfortunately, the timing of the Prague congress completely overlapped the triennial congress of the International Society of Theoretical and Applied Limnology (SIL in Cape Town, South Africa. This large meeting in a very attractive setting attracted many cladocerologists from all over the world, including Europe. Therefore, the Daphnia section of the Prague ISIRD meeting remained moderate in size, attracting 13 contributions (eight talks

  9. Transgenic mouse models in the study of reproduction: insights into GATA protein function.

    Science.gov (United States)

    Tevosian, Sergei G

    2014-07-01

    For the past 2 decades, transgenic technology in mice has allowed for an unprecedented insight into the transcriptional control of reproductive development and function. The key factor among the mouse genetic tools that made this rapid advance possible is a conditional transgenic approach, a particularly versatile method of creating gene deletions and substitutions in the mouse genome. A centerpiece of this strategy is an enzyme, Cre recombinase, which is expressed from defined DNA regulatory elements that are active in the tissue of choice. The regulatory DNA element (either genetically engineered or natural) assures Cre expression only in predetermined cell types, leading to the guided deletion of genetically modified (flanked by loxP or 'floxed' by loxP) gene loci. This review summarizes and compares the studies in which genes encoding GATA family transcription factors were targeted either globally or by Cre recombinases active in the somatic cells of ovaries and testes. The conditional gene loss experiments require detailed knowledge of the spatial and temporal expression of Cre activity, and the challenges in interpreting the outcomes are highlighted. These studies also expose the complexity of GATA-dependent regulation of gonadal gene expression and suggest that gene function is highly context dependent. © 2014 Society for Reproduction and Fertility.

  10. Baryon number fluctuations in chiral effective models and their phenomenological implications

    Science.gov (United States)

    Almási, Gábor András; Friman, Bengt; Redlich, Krzysztof

    2017-07-01

    We study the critical properties of net-baryon-number fluctuations at the chiral restoration transition in a medium at finite temperature and net baryon density. The chiral dynamics of quantum chromodynamics (QCD) is modeled by the Polyakov-loop extended quark-meson Lagrangian that includes the coupling of quarks to vector meson and temporal gauge fields. The functional renormalization group is employed to properly account for the O (4 ) criticality at the phase boundary. We focus on the properties and systematics of ratios of the net-baryon-number cumulants χBn, for 1 ≤n ≤6 , near the phase boundary. The results are presented in the context of the recent experimental data of the STAR Collaboration on fluctuations of the net proton number in heavy-ion collisions at RHIC. We show that the model results for the energy dependence of the cumulant ratios are in good overall agreement with the data, with one exception. At center-of-mass energies below 19.6 GeV, we find that the measured fourth-order cumulant deviates considerably from the model results, which incorporate the expected O (4 ) and Z (2 ) criticality. We assess the influence of model assumptions and in particular of repulsive vector-interactions, which are used to modify the location of the critical end point in the model, on the cumulants ratios. Finally, we discuss a possibility to test to what extent the fluctuations are affected by nonequilibrium dynamics by comparing certain ratios of cumulants.

  11. Fish reproduction

    National Research Council Canada - National Science Library

    Rocha, Maria João; Arukwe, Augustine; Kapoor, B. G

    2008-01-01

    ... of reproductive systems is essential for such studies. Fishes comprise over 28,000 species, with a remarkable variability in morphology, physiology and environmental adaptation. Knowledge on fish reproduction is scattered across numerous sources that shows a dynamic research field. The Editors believe it to be an opportune moment for a...

  12. Net-baryon number fluctuations in the hybrid quark-meson-nucleon model at finite density

    Science.gov (United States)

    Marczenko, Michał; Sasaki, Chihiro

    2018-02-01

    We study the mean-field thermodynamics and the characteristics of the net-baryon number fluctuations at the phase boundaries for the chiral and deconfinement transitions in the hybrid quark-meson-nucleon model. The chiral dynamics is described in the linear sigma model, whereas the quark confinement is manipulated by a medium-dependent modification of the particle distribution functions, where an additional scalar field is introduced. At low temperature and finite baryon density, the model predicts a first-, second-order chiral phase transition, or a crossover, depending on the expectation value of the scalar field, and a first-order deconfinement phase transition. We focus on the influence of the confinement over higher-order cumulants of the net-baryon number density. We find that the cumulants show a substantial enhancement around the chiral phase transition; they are not as sensitive to the deconfinement transition.

  13. Studies on reproductive stress caused by candidate Gram positive and Gram negative bacteria using model organism, Caenorhabditis elegans.

    Science.gov (United States)

    Sharika, Rajasekharan; Subbaiah, Priya; Balamurugan, Krishnaswamy

    2018-04-05

    Microbial association with a host using model system C. elegans have been widely studied based on factors such as host survival, the mode of infection, disease pathogenesis and the role of various players regulated during infection. The influence of pathogenic microorganism on reproduction and associated issues has not been explored fully. The present study focuses on the impact of bacterial infection on male reproductive parameters such as spermatogenesis and spermiogenesis, including physiological aspects like tail morphology defect and underlying molecular mechanisms that have been perturbed. In order to compare the consequence of infection caused by Gram positive and negative bacteria, Staphylococcus aureus and Vibrio alginolyticus were chosen as candidate pathogens, respectively. Microscopic observations revealed notable changes in tail morphology during 24 h of infection, as along with change in sperm size and activation. The Real Time-PCR results suggest the plausible down regulation of DBL-1/TGF-β pathway suggesting the morphological change in the tail. Shotgun proteomics further lead to the identification of MAG-1, Magonashi Protein a candidate regulatory player that affects spermatogenesis and HIF-1 that regulate during stress in both Gram positive and Gram negative infection. The protein-protein interaction with detected proteins revealed RACK-1 protein and mTOR pathway in S. aureus and V. alginolyticus respectively interacting with MAG-1 protein, which plays an important role in spermatogenesis termination in hermaphrodites during L4 to adult switch. This study paves a way to understand the candidate players that regulate reproduction during bacterial infection. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Unraveling estradiol metabolism and involvement in the reproductive cycle of non-vertebrate animals: The sea urchin model.

    Science.gov (United States)

    Silvia, Mercurio; Paolo, Tremolada; Nobile, Maria; Denise, Fernandes; Cinta, Porte; Michela, Sugni

    2015-12-01

    Estradiol (E2) is a well-known hormone in vertebrates whereas in invertebrates its unambiguous presence was verified only in some species. Weather this presence is also associated to similarly conserved roles in animal phylogeny is similarly uncertain. Due to their phylogenetic position, echinoderms represent ideal experimental models to provide evolutionary insights into estrogen appearance and function. Therefore, in this research, we investigated if E2 is truly present and has a role in the reproductive biology of the sea urchin Paracentrotus lividus. Presence of 17β estradiol in body fluids was confirmed by liquid chromatography-mass spectrometry. By immunological methods (RIA) we evaluated the physiological circulating E2 levels of adult specimens and, on the basis of these, we directly administered E2 to study its metabolism and its putative effects on gonad development at physiological doses. Although different E2 tested concentrations, a correspondent dose-dependent increase of hormone levels was not found in both body fluids and gonads, suggesting the presence of potent homeostatic/detoxification mechanisms. These latter do not involve enzymes such as aromatase-like, sulfotransferase-like and acyltransferase-like, whose activities were not affected by E2 administration. Despite the increase of endogenous E2, the treatment did not induce significant variations in none of the considered reproductive parameters. Overall, this research (1) provides definitive evidence of E2 presence in sea urchin tissues and (2) demonstrate that, differently from vertebrates and starfish, E2 does not play a key role in sea urchins reproductive processes. Intra-phylum differences suggest the existence of class-specific hormonal mechanisms and highlight the risk of Phylum generalization. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Periodontal Dressing-containing Green Tea Epigallocathechin gallate Increases Fibroblasts Number in Gingival Artifical Wound Model

    Directory of Open Access Journals (Sweden)

    Ardisa U. Pradita

    2014-04-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Green tea leaf (Camellia sinensis is one of herbal plants that is used for traditional medicine. Epigallocatechin gallate (EGCG in green tea is the most potential polyphenol component and has the strongest biological activity. It is known that EGCG has potential effect on wound healing. Objective: This study aimed to determine the effect of adding green tea EGCG into periodontal dressing on the number of fibroblasts after gingival artificial wound in animal model. Methods: Gingival artifical wound model was performed using 2mm punch biopsy on 24 rabbits (Oryctolagus cuniculus. The animals were divided into two groups. Periodontal dressing with EGCG and without EGCG was applied to the experimental and control group, respectively. Decapitation period was scheduled at day 3, 5, and 7 after treatment. Histological analysis to count the number of fibroblasts was performed. Results: Number of fibroblasts was significantly increased in time over the experimental group treated with EGCG periodontal dressing compared to control (p<0.05. Conclusion: EGCG periodontal dressing could increase the number of fibroblast, therefore having role in wound healing after periodontal surgery in animal model.DOI: 10.14693/jdi.v20i3.197

  16. A predictive model for high-quality blastocyst based on blastomere number, fragmentation, and symmetry.

    Science.gov (United States)

    Yu, Cheng-He; Zhang, Ruo-Peng; Li, Juan; A, Zhou-Cun

    2018-03-03

    The aim of this study was to create a predictive model for high-quality blastocyst progression based on the traditional morphology parameters of embryos. A total of 1564 embryos from 234 women underwent conventional in vitro fertilization and were involved in the present study. High-quality blastocysts were defined as having a grade of at least 3BB, and all embryos were divided based on the development of high-quality blastocysts (group HQ) or the failure to develop high-quality blastocysts (group NHQ). A retrospective analysis of day-3 embryo parameters, focused on blastomere number, fragmentation, the presence of a vacuole, symmetry, and the presence of multinucleated blastomeres was conducted. All parameters were related to high-quality blastocysts (p quality blastocysts. Parameters are indicated by s_bn (blastomere number), s_f (fragmentation), s_pv (presence of a vacuole), s_s (symmetry), and s_MNB (multinucleated blastomeres). Subsequently, univariate and multivariate logistic regression analyses were conducted to explore their relationship. In the multivariate logistic regression analysis, a predictive model was constructed, and a parameter Hc was created based on the s_bn, s_f, and s_s parameters and their corresponding odds ratios. The value of Hc in group HQ was significantly higher than that in group NHQ. A receiver operating characteristic curve was used to test the effectiveness of the model. An area under the curve of 0.790, with a 95% confidence interval of 0.766-0.813, was calculated. A dataset was used to validate the predictive utility of the model. Moreover, another dataset was used to ensure that the model can be applied to predict the implantation of day-3 embryos. A predictive model for high-quality blastocysts was created based on blastomere number, fragmentation, and symmetry. This model provides novel information on the selection of potential embryos.

  17. Development of a stochastic agent-based model to evaluate surveillance strategies for detection of emergent porcine reproductive and respiratory syndrome strains.

    Science.gov (United States)

    Arruda, A G; Poljak, Z; Knowles, D; McLean, A

    2017-06-12

    The objective of the current study was to develop a stochastic agent-based model using empirical data from Ontario (Canada) swine sites in order to evaluate different surveillance strategies for detection of emerging porcine reproductive and respiratory syndrome virus (PRRSV) strains at the regional level. Four strategies were evaluated, including (i) random sampling of fixed numbers of swine sites monthly; (ii) risk-based sampling of fixed numbers, specifically of breeding sites (high-consequence sites); (iii) risk-based sampling of fixed numbers of low biosecurity sites (high-risk); and (iv) risk-based sampling of breeding sites that are characterized as low biosecurity sites (high-risk/high-consequence). The model simulated transmission of a hypothetical emerging PRRSV strain between swine sites through three important industry networks (production system, truck and feed networks) while considering sites' underlying immunity due to past or recent exposure to heterologous PRRSV strains, as well as demographic, geographic and biosecurity-related PRRS risk factors. Outcomes of interest included surveillance system sensitivity and time to detection of the three first cases over a period of approximately three years. Surveillance system sensitivities were low and time to detection of three first cases was long across all examined scenarios. Traditional modes of implementing high-risk and high-consequence risk-based surveillance based on site's static characteristics do not appear to substantially improve surveillance system sensitivity. Novel strategies need to be developed and considered for rapid detection of this and other emerging swine infectious diseases. None of the four strategies compared herein appeared optimal for early detection of an emerging PPRSV strain at the regional level considering model assumptions, the underlying population of interest, and absence of other forms of surveillance.

  18. Number of Clusters and the Quality of Hybrid Predictive Models in Analytical CRM

    Directory of Open Access Journals (Sweden)

    Łapczyński Mariusz

    2014-08-01

    Full Text Available Making more accurate marketing decisions by managers requires building effective predictive models. Typically, these models specify the probability of customer belonging to a particular category, group or segment. The analytical CRM categories refer to customers interested in starting cooperation with the company (acquisition models, customers who purchase additional products (cross- and up-sell models or customers intending to resign from the cooperation (churn models. During building predictive models researchers use analytical tools from various disciplines with an emphasis on their best performance. This article attempts to build a hybrid predictive model combining decision trees (C&RT algorithm and cluster analysis (k-means. During experiments five different cluster validity indices and eight datasets were used. The performance of models was evaluated by using popular measures such as: accuracy, precision, recall, G-mean, F-measure and lift in the first and in the second decile. The authors tried to find a connection between the number of clusters and models' quality.

  19. Universal reduction of effective coordination number in the quasi-one-dimensional Ising model

    Science.gov (United States)

    Todo, Synge

    2006-09-01

    Critical temperature of quasi-one-dimensional general-spin Ising ferromagnets is investigated by means of the cluster Monte Carlo method performed on infinite-length strips, L×∞ or L×L×∞ . We find that in the weak interchain coupling regime the critical temperature as a function of the interchain coupling is well-described by a chain mean-field formula with a reduced effective coordination number, as the quantum Heisenberg antiferromagnets recently reported by Yasuda [Phys. Rev. Lett. 94, 217201 (2005)]. It is also confirmed that the effective coordination number is independent of the spin size. We show that in the weak interchain coupling limit the effective coordination number is, irrespective of the spin size, rigorously given by the quantum critical point of a spin- 1/2 transverse-field Ising model.

  20. A new modeling and solution approach for the number partitioning problem

    Directory of Open Access Journals (Sweden)

    Bahram Alidaee

    2005-01-01

    Full Text Available The number partitioning problem has proven to be a challenging problem for both exact and heuristic solution methods. We present a new modeling and solution approach that consists of recasting the problem as an unconstrained quadratic binary program that can be solved by efficient metaheuristic methods. Our approach readily accommodates both the common two-subset partition case as well as the more general case of multiple subsets. Preliminary computational experience is presented illustrating the attractiveness of the method.

  1. A continuous-index hidden Markov jump process for modeling DNA copy number data.

    Science.gov (United States)

    Stjernqvist, Susann; Rydén, Tobias

    2009-10-01

    The number of copies of DNA in human cells can be measured using array comparative genomic hybridization (aCGH), which provides intensity ratios of sample to reference DNA at genomic locations corresponding to probes on a microarray. In the present paper, we devise a statistical model, based on a latent continuous-index Markov jump process, that is aimed to capture certain features of aCGH data, including probes that are unevenly long, unevenly spaced, and overlapping. The model has a continuous state space, with 1 state representing a normal copy number of 2, and the rest of the states being either amplifications or deletions. We adopt a Bayesian approach and apply Markov chain Monte Carlo (MCMC) methods for estimating the parameters and the Markov process. The model can be applied to data from both tiling bacterial artificial chromosome arrays and oligonucleotide arrays. We also compare a model with normal distributed noise to a model with t-distributed noise, showing that the latter is more robust to outliers.

  2. Testing a model of componential processing of multi-symbol numbers-evidence from measurement units.

    Science.gov (United States)

    Huber, Stefan; Bahnmueller, Julia; Klein, Elise; Moeller, Korbinian

    2015-10-01

    Research on numerical cognition has addressed the processing of nonsymbolic quantities and symbolic digits extensively. However, magnitude processing of measurement units is still a neglected topic in numerical cognition research. Hence, we investigated the processing of measurement units to evaluate whether typical effects of multi-digit number processing such as the compatibility effect, the string length congruity effect, and the distance effect are also present for measurement units. In three experiments, participants had to single out the larger one of two physical quantities (e.g., lengths). In Experiment 1, the compatibility of number and measurement unit (compatible: 3 mm_6 cm with 3 mm) as well as string length congruity (congruent: 1 m_2 km with m 2 characters) were manipulated. We observed reliable compatibility effects with prolonged reaction times (RT) for incompatible trials. Moreover, a string length congruity effect was present in RT with longer RT for incongruent trials. Experiments 2 and 3 served as control experiments showing that compatibility effects persist when controlling for holistic distance and that a distance effect for measurement units exists. Our findings indicate that numbers and measurement units are processed in a componential manner and thus highlight that processing characteristics of multi-digit numbers generalize to measurement units. Thereby, our data lend further support to the recently proposed generalized model of componential multi-symbol number processing.

  3. Advanced Daily Prediction Model for National Suicide Numbers with Social Media Data.

    Science.gov (United States)

    Lee, Kyung Sang; Lee, Hyewon; Myung, Woojae; Song, Gil-Young; Lee, Kihwang; Kim, Ho; Carroll, Bernard J; Kim, Doh Kwan

    2018-04-01

    Suicide is a significant public health concern worldwide. Social media data have a potential role in identifying high suicide risk individuals and also in predicting suicide rate at the population level. In this study, we report an advanced daily suicide prediction model using social media data combined with economic/meteorological variables along with observed suicide data lagged by 1 week. The social media data were drawn from weblog posts. We examined a total of 10,035 social media keywords for suicide prediction. We made predictions of national suicide numbers 7 days in advance daily for 2 years, based on a daily moving 5-year prediction modeling period. Our model predicted the likely range of daily national suicide numbers with 82.9% accuracy. Among the social media variables, words denoting economic issues and mood status showed high predictive strength. Observed number of suicides one week previously, recent celebrity suicide, and day of week followed by stock index, consumer price index, and sunlight duration 7 days before the target date were notable predictors along with the social media variables. These results strengthen the case for social media data to supplement classical social/economic/climatic data in forecasting national suicide events.

  4. Reproductive physiology of a humanized GnRH receptor mouse model: application in evaluation of human-specific analogs.

    Science.gov (United States)

    Tello, Javier A; Kohout, Trudy; Pineda, Rafael; Maki, Richard A; Scott Struthers, R; Millar, Robert P

    2013-07-01

    The human GnRH receptor (GNRHR1) has a specific set of properties with physiological and pharmacological influences not appropriately modeled in laboratory animals or cell-based systems. To address this deficiency, we have generated human GNRHR1 knock-in mice and described their reproductive phenotype. Measurement of pituitary GNRHR1 transcripts from homozygous human GNRHR1 knock-in (ki/ki) mice revealed a severe reduction (7- to 8-fold) compared with the mouse Gnrhr1 in wild-type mice. ¹²⁵I-GnRH binding assays on pituitary membrane fractions corroborated reduced human GNRHR1 protein expression in ki/ki mice, as occurs with transfection of human GNRHR1 in cell lines. Female homozygous knock-in mice displayed normal pubertal onset, indicating that a large reduction in GNRHR1 expression is sufficient for this process. However, ki/ki females exhibited periods of prolonged estrous and/or metestrous and reduced fertility. No impairment was found in reproductive maturity or adult fertility in male ki/ki mice. Interestingly, the serum LH response to GnRH challenge was reduced in both knock-in males and females, indicating a reduced GNRHR1 signaling capacity. Small molecules targeting human GPCRs usually have poor activities at homologous rodent receptors, thus limiting their use in preclinical development. Therefore, we tested a human-specific GnRH1 antagonist, NBI-42902, in our mouse model and demonstrated abrogation of a GnRH1-induced serum LH rise in ki/ki mice and an absence of effect in littermates expressing the wild-type murine receptor. This novel model provides the opportunity to study the human receptor in vivo and for screening the activity of human-specific GnRH analogs.

  5. Determination model for cetane number of biodiesel at different fatty acid composition: a review

    Directory of Open Access Journals (Sweden)

    Michal Angelovič

    2014-05-01

    Full Text Available The most accepted definition of biodiesel is stated at the EU technical regulation EN 14214 (2008 or in the USA in ASTM 6751-02. As a result of this highly strict description only methyl esters of fatty acids conform to these definitions, nevertheless the term ‘‘biodiesel’’ is spread out to other alkyl fatty esters. Some countries have adopted bioethanol for replacement of methanol in biodiesel transesterification and thus assuring a fully biological fuel. Of course, such position brings some problems in fulfilling technical requirements of EN 14214 or ASTM 6751-02. Biodiesel is actually a less complex mixture than petrodiesel, but different feedstock origins and the effect of seasonality may impose difficulties in fuel quality control. Since biodiesel is an alternative diesel fuel derived from the transesterification of triacylglycerol comprised materials, such as vegetable oils or animal fats, with simple alcohols to furnish the corresponding mono-alkyl esters, its composition depends on the raw material used, the cultivated area location, and harvest time. The choice of the raw material is usually the most important factor for fluctuations of biodiesel composition, because different vegetable oils and animal fats may contain different types of fatty acids. Important properties of this fuel vary significantly with the composition of the mixture. Cetane number, melting point, degree of saturation, density, cloud point, pour point, viscosity, and nitrogen oxides exhaust emission (NOx, for instance, deserve to be mentioned. One of the most important fuel quality indicators is the cetane number; however its experimental determination may be an expensive and lengthy task. To weaken situation concerning biodiesel, the availability of data in the literature is also scarce. In such scenario, the use of reliable models to predict the cetane number or any other essential characteristic may be of great utility. We reviewed available literature to

  6. Implications of hormonal influences on sexual behavior for demographic models of reproduction.

    Science.gov (United States)

    Campbell, B C; Udry, J R

    1994-02-18

    In exploring the implications of hormonal influences on sexual behavior for reproduction, we have focused on androgens because of the convincing evidence for androgenic effects on female sexual motivation. We have been guided by the simple idea, based on clinical findings among hyperandrogenic women, that higher testosterone levels will increase female sexual motivation which in turn will result in increased coital frequency. However, careful consideration of the evidence fails to confirm such a role for testosterone in sexual behavior among normal women at any point in the reproductive span. While some amount of testosterone appears to be important in maintaining female sexual motivation, there is little evidence that variation in testosterone within the normal range is associated with variation in sexual motivation. Reported associations between testosterone and sexual behavior among married women cannot be interpreted as resulting from androgenic effects on sexual motivation. Thus we are left with the task of explaining why testosterone does not appear to play the same role in libido among hyperandrogenic and normal women. As mentioned earlier, some of the difference may attributable to the much higher levels of testosterone among hyperandrogenic women. Sherwin points out that the levels of sexual motivation decline with declining testosterone levels even while testosterone is well above normally occurring levels. It is possible that the brain is simply not sensitive to the variation in testosterone levels found in normal women. Other evidence suggests that the presence of intact ovaries may be equally important. A recent study of androgen replacement in naturally post-menopausal women failed to find a dramatic effect of testosterone on sexual motivation and behavior, despite levels similar to those in studies on surgically menopausal women, pointing to the importance of other factors associated with the presence of ovaries. A similar point can be made with

  7. Gene Copy Number Analysis for Family Data Using Semiparametric Copula Model

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    Ao Yuan

    2008-01-01

    Full Text Available Gene copy number changes are common characteristics of many genetic disorders. A new technology, array comparative genomic hybridization (a-CGH, is widely used today to screen for gains and losses in cancers and other genetic diseases with high resolution at the genome level or for specific chromosomal region. Statistical methods for analyzing such a-CGH data have been developed. However, most of the existing methods are for unrelated individual data and the results from them provide explanation for horizontal variations in copy number changes. It is potentially meaningful to develop a statistical method that will allow for the analysis of family data to investigate the vertical kinship effects as well. Here we consider a semiparametric model based on clustering method in which the marginal distributions are estimated nonparametrically, and the familial dependence structure is modeled by copula. The model is illustrated and evaluated using simulated data. Our results show that the proposed method is more robust than the commonly used multivariate normal model. Finally, we demonstrated the utility of our method using a real dataset.

  8. Basic reproduction number of coxsackievirus type A6 and A16 and enterovirus 71: estimates from outbreaks of hand, foot and mouth disease in Singapore, a tropical city-state.

    Science.gov (United States)

    Lim, C T K; Jiang, L; Ma, S; James, L; Ang, L W

    2016-04-01

    Coxsackievirus A6 (CV-A6), coxsackievirus A16 (CV-A16) and enterovirus 71 (EV-A71) were the major enteroviruses causing nationwide hand, foot and mouth disease (HFMD) epidemics in Singapore in the last decade. We estimated the basic reproduction number (R 0) of these enteroviruses to obtain a better understanding of their transmission dynamics. We merged records of cases from HFMD outbreaks reported between 2007 and 2012 with laboratory results from virological surveillance. R 0 was estimated based on the cumulative number of reported cases in the initial growth phase of each outbreak associated with the particular enterovirus type. A total of 33 HFMD outbreaks were selected based on the inclusion criteria specified for our study, of which five were associated with CV-A6, 13 with CV-A16, and 15 with EV-A71. The median R 0 was estimated to be 5·04 [interquartile range (IQR) 3·57-5·16] for CV-A6, 2·42 (IQR 1·85-3·36) for CV-A16, and 3·50 (IQR 2·36-4·53) for EV-A71. R 0 was not significantly associated with number of infected children (P = 0·86), number of exposed children (P = 0·94), and duration of the outbreak (P = 0·05). These enterovirus-specific R 0 estimates will be helpful in providing insights into the potential growth of future HFMD epidemics and outbreaks for timely implementation of disease control measures, together with disease dynamics such as severity of the cases.

  9. VARIATIONS IN REPRODUCTIVE TOXICANT IDENTIFICATION

    Energy Technology Data Exchange (ETDEWEB)

    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. Keefektifan Model Pembelajaran Number Head Together Berbantuan Metode Discovery terhadap Hasil Belajar Matematika

    Directory of Open Access Journals (Sweden)

    Ari Bintari

    2017-12-01

    Full Text Available Low mathematics learning outcomes and student activeness due to lack of effective learning model in optimizing students’ ability and motivation. The formulation of this research problem is whether the learning model Number Head Together (NHT with the help of effective discovery method to the result of student learning class III. This study aims to determine the effectiveness of the model with the help of the method of discovery of learning mathematics class III SDN Mewek. Pre-experimental method used in this research, which tests, documentation study, and observation sheet as its instruments. Based on the results of the final analysis that has been done visible from the percentage of mastery learning aiswa show learning without using learning model NHT as 5 students who completed with 25% percent and 15 students have not completed with the percentage 75%. Whereas after being given (posttest treatment using NHT learning model and pizza media fractions that complete 16 students with percentage 80% and 4 students have not completed with percentage 20%. It is reinforced by t-test, that students’ achievement has been increased significantly by NHT model.

  11. Scoping review identifies significant number of knowledge translation theories, models and frameworks with limited use.

    Science.gov (United States)

    Strifler, Lisa; Cardoso, Roberta; McGowan, Jessie; Cogo, Elise; Nincic, Vera; Khan, Paul A; Scott, Alistair; Ghassemi, Marco; MacDonald, Heather; Lai, Yonda; Treister, Victoria; Tricco, Andrea C; Straus, Sharon E

    2018-04-13

    To conduct a scoping review of knowledge translation (KT) theories, models and frameworks that have been used to guide dissemination or implementation of evidence-based interventions targeted to prevention and/or management of cancer or other chronic diseases. We used a comprehensive multistage search process from 2000-2016, which included traditional bibliographic database searching, searching using names of theories, models and frameworks, and cited reference searching. Two reviewers independently screened the literature and abstracted data. We found 596 studies reporting on the use of 159 KT theories, models or frameworks. A majority (87%) of the identified theories, models or frameworks were used in five or fewer studies, with 60% used once. The theories, models and frameworks were most commonly used to inform planning/design, implementation and evaluation activities, and least commonly used to inform dissemination and sustainability/scalability activities. Twenty-six were used across the full implementation spectrum (from planning/design to sustainability/scalability) either within or across studies. All were used for at least individual-level behavior change, while 48% were used for organization-level, 33% for community-level and 17% for system-level change. We found a significant number of KT theories, models and frameworks with a limited evidence base describing their use. Copyright © 2018. Published by Elsevier Inc.

  12. An Architecturally Constrained Model of Random Number Generation and its Application to Modelling the Effect of Generation Rate

    Directory of Open Access Journals (Sweden)

    Nicholas J. Sexton

    2014-07-01

    Full Text Available Random number generation (RNG is a complex cognitive task for human subjects, requiring deliberative control to avoid production of habitual, stereotyped sequences. Under various manipulations (e.g., speeded responding, transcranial magnetic stimulation, or neurological damage the performance of human subjects deteriorates, as reflected in a number of qualitatively distinct, dissociable biases. For example, the intrusion of stereotyped behaviour (e.g., counting increases at faster rates of generation. Theoretical accounts of the task postulate that it requires the integrated operation of multiple, computationally heterogeneous cognitive control ('executive' processes. We present a computational model of RNG, within the framework of a novel, neuropsychologically-inspired cognitive architecture, ESPro. Manipulating the rate of sequence generation in the model reproduced a number of key effects observed in empirical studies, including increasing sequence stereotypy at faster rates. Within the model, this was due to time limitations on the interaction of supervisory control processes, namely, task setting, proposal of responses, monitoring, and response inhibition. The model thus supports the fractionation of executive function into multiple, computationally heterogeneous processes.

  13. The role of reproductive hormones in postpartum depression.

    Science.gov (United States)

    Schiller, Crystal Edler; Meltzer-Brody, Samantha; Rubinow, David R

    2015-02-01

    Despite decades of research aimed at identifying the causes of postpartum depression (PPD), PPD remains common, and the causes are poorly understood. Many have attributed the onset of PPD to the rapid perinatal change in reproductive hormones. Although a number of human and nonhuman animal studies support the role of reproductive hormones in PPD, several studies have failed to detect an association between hormone concentrations and PPD. The purpose of this review is to examine the hypothesis that fluctuations in reproductive hormone levels during pregnancy and the postpartum period trigger PPD in susceptible women. We discuss and integrate the literature on animal models of PPD and human studies of reproductive hormones and PPD. We also discuss alternative biological models of PPD to demonstrate the potential for multiple PPD phenotypes and to describe the complex interplay of changing reproductive hormones and alterations in thyroid function, immune function, hypothalamic-pituitary-adrenal (HPA) axis function, lactogenic hormones, and genetic expression that may contribute to affective dysfunction. There are 3 primary lines of inquiry that have addressed the role of reproductive hormones in PPD: nonhuman animal studies, correlational studies of postpartum hormone levels and mood symptoms, and hormone manipulation studies. Reproductive hormones influence virtually every biological system implicated in PPD, and a subgroup of women seem to be particularly sensitive to the effects of perinatal changes in hormone levels. We propose that these women constitute a "hormone-sensitive" PPD phenotype, which should be studied independent of other PPD phenotypes to identify underlying pathophysiology and develop novel treatment targets.

  14. Instanton-mediated baryon number violation in non-universal gauge extended models

    Science.gov (United States)

    Fuentes-Martín, J.; Portolés, J.; Ruiz-Femenía, P.

    2015-01-01

    Instanton solutions of non-abelian Yang-Mills theories generate an effective action that may induce lepton and baryon number violations, namely Δ B = Δ L = n f , being n f the number of families coupled to the gauge group. In this article we study instanton mediated processes in a SU(2) ℓ ⊗SU(2) h ⊗U(1) extension of the Standard Model that breaks universality by singularizing the third family. In the construction of the instanton Green functions we account systematically for the inter-family mixing. This allows us to use the experimental bounds on proton decay in order to constrain the gauge coupling of SU(2) h . Tau lepton non-leptonic and radiative decays with Δ B = Δ L = 1 are also analysed.

  15. Reproductive biology and its impact on body size: comparative analysis of mammalian, avian and dinosaurian reproduction.

    Science.gov (United States)

    Werner, Jan; Griebeler, Eva Maria

    2011-01-01

    Janis and Carrano (1992) suggested that large dinosaurs might have faced a lower risk of extinction under ecological changes than similar-sized mammals because large dinosaurs had a higher potential reproductive output than similar-sized mammals (JC hypothesis). First, we tested the assumption underlying the JC hypothesis. We therefore analysed the potential reproductive output (reflected in clutch/litter size and annual offspring number) of extant terrestrial mammals and birds (as "dinosaur analogs") and of extinct dinosaurs. With the exception of rodents, the differences in the reproductive output of similar-sized birds and mammals proposed by Janis and Carrano (1992) existed even at the level of single orders. Fossil dinosaur clutches were larger than litters of similar-sized mammals, and dinosaur clutch sizes were comparable to those of similar-sized birds. Because the extinction risk of extant species often correlates with a low reproductive output, the latter difference suggests a lower risk of population extinction in dinosaurs than in mammals. Second, we present a very simple, mathematical model that demonstrates the advantage of a high reproductive output underlying the JC hypothesis. It predicts that a species with a high reproductive output that usually faces very high juvenile mortalities will benefit more strongly in terms of population size from reduced juvenile mortalities (e.g., resulting from a stochastic reduction in population size) than a species with a low reproductive output that usually comprises low juvenile mortalities. Based on our results, we suggest that reproductive strategy could have contributed to the evolution of the exceptional gigantism seen in dinosaurs that does not exist in extant terrestrial mammals. Large dinosaurs, e.g., the sauropods, may have easily sustained populations of very large-bodied species over evolutionary time.

  16. Reproductive biology and its impact on body size: comparative analysis of mammalian, avian and dinosaurian reproduction.

    Directory of Open Access Journals (Sweden)

    Jan Werner

    Full Text Available Janis and Carrano (1992 suggested that large dinosaurs might have faced a lower risk of extinction under ecological changes than similar-sized mammals because large dinosaurs had a higher potential reproductive output than similar-sized mammals (JC hypothesis. First, we tested the assumption underlying the JC hypothesis. We therefore analysed the potential reproductive output (reflected in clutch/litter size and annual offspring number of extant terrestrial mammals and birds (as "dinosaur analogs" and of extinct dinosaurs. With the exception of rodents, the differences in the reproductive output of similar-sized birds and mammals proposed by Janis and Carrano (1992 existed even at the level of single orders. Fossil dinosaur clutches were larger than litters of similar-sized mammals, and dinosaur clutch sizes were comparable to those of similar-sized birds. Because the extinction risk of extant species often correlates with a low reproductive output, the latter difference suggests a lower risk of population extinction in dinosaurs than in mammals. Second, we present a very simple, mathematical model that demonstrates the advantage of a high reproductive output underlying the JC hypothesis. It predicts that a species with a high reproductive output that usually faces very high juvenile mortalities will benefit more strongly in terms of population size from reduced juvenile mortalities (e.g., resulting from a stochastic reduction in population size than a species with a low reproductive output that usually comprises low juvenile mortalities. Based on our results, we suggest that reproductive strategy could have contributed to the evolution of the exceptional gigantism seen in dinosaurs that does not exist in extant terrestrial mammals. Large dinosaurs, e.g., the sauropods, may have easily sustained populations of very large-bodied species over evolutionary time.

  17. Patient specific respiratory motion modeling using a limited number of 3D lung CT images.

    Science.gov (United States)

    Cui, Xueli; Gao, Xin; Xia, Wei; Liu, Yangchuan; Liang, Zhiyuan

    2014-01-01

    To build a patient specific respiratory motion model with a low dose, a novel method was proposed that uses a limited number of 3D lung CT volumes with an external respiratory signal. 4D lung CT volumes were acquired for patients with in vitro labeling on the upper abdominal surface. Meanwhile, 3D coordinates of in vitro labeling were measured as external respiratory signals. A sequential correspondence between the 4D lung CT and the external respiratory signal was built using the distance correlation method, and a 3D displacement for every registration control point in the CT volumes with respect to time can be obtained by the 4D lung CT deformable registration. A temporal fitting was performed for every registration control point displacements and an external respiratory signal in the anterior-posterior direction respectively to draw their fitting curves. Finally, a linear regression was used to fit the corresponding samples of the control point displacement fitting curves and the external respiratory signal fitting curve to finish the pulmonary respiration modeling. Compared to a B-spline-based method using the respiratory signal phase, the proposed method is highly advantageous as it offers comparable modeling accuracy and target modeling error (TME); while at the same time, the proposed method requires 70% less 3D lung CTs. When using a similar amount of 3D lung CT data, the mean of the proposed method's TME is smaller than the mean of the PCA (principle component analysis)-based methods' TMEs. The results indicate that the proposed method is successful in striking a balance between modeling accuracy and number of 3D lung CT volumes.

  18. Multistate models for estimation of survival and reproduction in the Grey-headed Albatross (Thalassarche chrysostoma)

    Science.gov (United States)

    Converse, Sarah J.; Kendall, William L.; Doherty, Paul F.; Ryan, Peter G.

    2009-01-01

    Reliable information on demography is necessary for conservation of albatrosses, the most threatened family of pelagic birds. Albatross survival has been estimated using mark-recapture data and the Cormack-Jolly-Seber (CJS) model. However, albatross exhibit skipped breeding, violating assumptions of the CJS model. Multistate modeling integrating unobservable states is a promising tool for such situations. We applied multistate models to data on Grey-headed Albatross (Talassarche chrysostoma) to evaluate model performance and describe demographic patterns. These included a multistate equivalent of the CJS model (MS-2), including successful and failed breeding states and ignoring temporary emigration, and three versions of a four-state multistate model that accounts for temporary emigration by integrating unobservable states: a model (MS-4) with one sample per breeding season, a robust design model (RDMS-4) with multiple samples per season and geographic closure within the season, and an open robust design model (ORDMS-4) with multiple samples per season and staggered entry and exit of animals within the season. Survival estimates from the MS-2 model were higher than those from the MS-4 model, which resulted in apparent percent relative bias averaging 2.2%. The ORDMS-4 model was more appropriate than the RDMS-4 model, given that staggered entry and exit occurred. Annual survival probability for Greyheaded Albatross at Marion Island was 0.951 ± 0.006 (SE), and the probability of skipped breeding in a subsequent year averaged 0.938 for successful and 0.163 for failed breeders. We recommend that multistate models with unobservable states, combined with robust-design sampling, be used in studies of species that exhibit temporary emigration.

  19. MODEL PEMBELAJARAN NUMBERED HEAD TOGETHER (NHT UNTUK MENINGKATKAN PERAN AKTIF SISWA BELAJAR MATA PELAJARAN SISTEM REM

    Directory of Open Access Journals (Sweden)

    Subur Riyono

    2016-12-01

    Full Text Available The Implementation of Numbered Head Together (NHT learning model to Enhance the students Active Role in Learning the Brake System. A thesis of Machine Engginering Education Study Program Faculty of Teacher Training and Educatioon of Sarjanawiyata Tamansiswa University Yogyakarta, 2016.The type of this research is action research including three cycles. Each cycle is conducted by four stages including 1. Planning 2. Implementing 3. Observing and 4. Reflexting. In collecting the Data, the researcher appied test, observation as well as document. The technique used in analyzing the observation sheet and test is quantitive deskriptive.  The result of this research showed that the implementation of Numbered Head Together (NHT learning model had enhanched both the students learning Active Role and the students’ learning results of the brake system subject to each cycle. It is proved by the increasing result of the observation sheet of the students learning Active Role from which the first cycle 44,57% having increased to the second cycle 16,57% becoming 61,14% and in the third cycle having increased 25,57% becoming 86,71%. Furthermore, based on the learning result test  of the first cycle gave the average grade of the pre test 62,28%, the average grade of the post test then 60,71%, the average grade 69,57% so the learning result increased 8,86% and in the second cycle gave the average grade of pretest 62,28% and the average post test then 75,42% increased the learning result 13,14% and the the test of the third cycle, the average pre test 65,14% and the average post test 83,42%.. Due to the research findings, it can be concluded that the implementation of the Numbered Head Together (NHT learning model can enhance the students learning Active Role as well as the results of the students learning in the brake system.

  20. Evaluation of Control Strategies for Porcine Reproductive and Respiratory Syndrome (PRRS) in Swine Breeding Herds Using a Discrete Event Agent-Based Model

    Science.gov (United States)

    Arruda, Andréia Gonçalves; Friendship, Robert; Carpenter, Jane; Greer, Amy; Poljak, Zvonimir

    2016-01-01

    The objective of this study was to develop a discrete event agent-based stochastic model to explore the likelihood of the occurrence of porcine reproductive and respiratory syndrome (PRRS) outbreaks in swine herds with different PRRS control measures in place. The control measures evaluated included vaccination with a modified-live attenuated vaccine and live-virus inoculation of gilts, and both were compared to a baseline scenario where no control measures were in place. A typical North American 1,000-sow farrow-to-wean swine herd was used as a model, with production and disease parameters estimated from the literature and expert opinion. The model constructed herein was not only able to capture individual animal heterogeneity in immunity to and shedding of the PRRS virus, but also the dynamic animal flow and contact structure typical in such herds under field conditions. The model outcomes included maximum number of females infected per simulation, and time at which that happened and the incidence of infected weaned piglets during the first year of challenge-virus introduction. Results showed that the baseline scenario produced a larger percentage of simulations resulting in outbreaks compared to the control scenarios, and interestingly some of the outbreaks occurred over long periods after virus introduction. The live-virus inoculation scenario showed promising results, with fewer simulations resulting in outbreaks than the other scenarios, but the negative impacts of maintaining a PRRS-positive population should be considered. Finally, under the assumptions of the current model, neither of the control strategies prevented the infection from spreading to the piglet population, which highlights the importance of maintaining internal biosecurity practices at the farrowing room level. PMID:27875546

  1. Evaluation of Control Strategies for Porcine Reproductive and Respiratory Syndrome (PRRS) in Swine Breeding Herds Using a Discrete Event Agent-Based Model.

    Science.gov (United States)

    Arruda, Andréia Gonçalves; Friendship, Robert; Carpenter, Jane; Greer, Amy; Poljak, Zvonimir

    2016-01-01

    The objective of this study was to develop a discrete event agent-based stochastic model to explore the likelihood of the occurrence of porcine reproductive and respiratory syndrome (PRRS) outbreaks in swine herds with different PRRS control measures in place. The control measures evaluated included vaccination with a modified-live attenuated vaccine and live-virus inoculation of gilts, and both were compared to a baseline scenario where no control measures were in place. A typical North American 1,000-sow farrow-to-wean swine herd was used as a model, with production and disease parameters estimated from the literature and expert opinion. The model constructed herein was not only able to capture individual animal heterogeneity in immunity to and shedding of the PRRS virus, but also the dynamic animal flow and contact structure typical in such herds under field conditions. The model outcomes included maximum number of females infected per simulation, and time at which that happened and the incidence of infected weaned piglets during the first year of challenge-virus introduction. Results showed that the baseline scenario produced a larger percentage of simulations resulting in outbreaks compared to the control scenarios, and interestingly some of the outbreaks occurred over long periods after virus introduction. The live-virus inoculation scenario showed promising results, with fewer simulations resulting in outbreaks than the other scenarios, but the negative impacts of maintaining a PRRS-positive population should be considered. Finally, under the assumptions of the current model, neither of the control strategies prevented the infection from spreading to the piglet population, which highlights the importance of maintaining internal biosecurity practices at the farrowing room level.

  2. Number-conserving interacting fermion models with exact topological superconducting ground states

    Science.gov (United States)

    Wang, Zhiyuan; Xu, Youjiang; Pu, Han; Hazzard, Kaden R. A.

    2017-09-01

    We present a method to construct number-conserving Hamiltonians whose ground states exactly reproduce an arbitrarily chosen BCS-type mean-field state. Such parent Hamiltonians can be constructed not only for the usual s -wave BCS state, but also for more exotic states of this form, including the ground states of Kitaev wires and two-dimensional topological superconductors. This method leads to infinite families of locally interacting fermion models with exact topological superconducting ground states. After explaining the general technique, we apply this method to construct two specific classes of models. The first one is a one-dimensional double wire lattice model with Majorana-like degenerate ground states. The second one is a two-dimensional px+i py superconducting model, where we also obtain analytic expressions for topologically degenerate ground states in the presence of vortices. Our models may provide a deeper conceptual understanding of how Majorana zero modes could emerge in condensed matter systems, as well as inspire novel routes to realize them in experiment.

  3. Equivalent Alkane Carbon Number of Live Crude Oil: A Predictive Model Based on Thermodynamics

    Directory of Open Access Journals (Sweden)

    Creton Benoit

    2016-09-01

    Full Text Available We took advantage of recently published works and new experimental data to propose a model for the prediction of the Equivalent Alkane Carbon Number of live crude oil (EACNlo for EOR processes. The model necessitates the a priori knowledge of reservoir pressure and temperature conditions as well as the initial gas to oil ratio. Additionally, some required volumetric properties for hydrocarbons were predicted using an equation of state. The model has been validated both on our own experimental data and data from the literature. These various case studies cover broad ranges of conditions in terms of API gravity index, gas to oil ratio, reservoir pressure and temperature, and composition of representative gas. The predicted EACNlo values reasonably agree with experimental EACN values, i.e. determined by comparison with salinity scans for a series of n-alkanes from nC8 to nC18. The model has been used to generate high pressure high temperature data, showing competing effects of the gas to oil ratio, pressure and temperature. The proposed model allows to strongly narrow down the spectrum of possibilities in terms of EACNlo values, and thus a more rational use of equipments.

  4. Acoustic model order reduction for the lowest condition number in inverse method

    Science.gov (United States)

    Madoliat, Reza; Nouri, Nowrouz Mohammad; Rahrovi, Ali

    2017-06-01

    Acoustic sources with wide surfaces can be broken down in a fluid environment into smaller acoustic sources. In this study, a general model is presented, indicating the type, number, direction, position and strength of these sources in such a way that the main sound and the sound of the equivalent sources match each other acceptably. When the position and direction of the source is determined, the strength of the source can be found using the inverse method. However, since the solution is not unique in the inverse method, a different acoustic strength is obtained for the sources if different positions are selected. By selecting an arrangement of general sources and using an optimization algorithm, the least possible mismatch between the main sound and the sound of equivalent sources can be achieved. In the inverse method, it is important to reduce the effects of measurement errors. The sensor placement and acoustic model order reduction (AMOR) are studied for reducing these effects.

  5. Blocking probability in the hose-model optical VPN with different number of wavelengths

    Science.gov (United States)

    Roslyakov, Alexander V.

    2017-04-01

    Connection setup with guaranteed quality of service (QoS) in the optical virtual private network (OVPN) is a major goal for the network providers. In order to support this we propose a QoS based OVPN connection set up mechanism over WDM network to the end customer. The proposed WDM network model can be specified in terms of QoS parameter such as blocking probability. We estimated this QoS parameter based on the hose-model OVPN. In this mechanism the OVPN connections also can be created or deleted according to the availability of the wavelengths in the optical path. In this paper we have considered the impact of the number of wavelengths on the computation of blocking probability. The goal of the work is to dynamically provide a best OVPN connection during frequent arrival of connection requests with QoS requirements.

  6. 32 CFR 2103.41 - Reproduction controls.

    Science.gov (United States)

    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. ...

  7. 32 CFR 2700.43 - Reproduction controls.

    Science.gov (United States)

    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 of...

  8. Assisted Reproductive Technologies : Implications for Women's ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Assisted Reproductive Technologies : Implications for Women's Reproductive Rights and Social Citizenship. There is a general perception that assisted reproductive technologies (ARTs) affect only a small number of affluent women in India. However, the ART industry - tied as it is to the vigorously pushed medical tourism ...

  9. Retrieving infinite numbers of patterns in a spin-glass model of immune networks

    Science.gov (United States)

    Agliari, E.; Annibale, A.; Barra, A.; Coolen, A. C. C.; Tantari, D.

    2017-01-01

    The similarity between neural and (adaptive) immune networks has been known for decades, but so far we did not understand the mechanism that allows the immune system, unlike associative neural networks, to recall and execute a large number of memorized defense strategies in parallel. The explanation turns out to lie in the network topology. Neurons interact typically with a large number of other neurons, whereas interactions among lymphocytes in immune networks are very specific, and described by graphs with finite connectivity. In this paper we use replica techniques to solve a statistical mechanical immune network model with “coordinator branches” (T-cells) and “effector branches” (B-cells), and show how the finite connectivity enables the coordinators to manage an extensive number of effectors simultaneously, even above the percolation threshold (where clonal cross-talk is not negligible). A consequence of its underlying topological sparsity is that the adaptive immune system exhibits only weak ergodicity breaking, so that also spontaneous switch-like effects as bi-stabilities are present: the latter may play a significant role in the maintenance of immune homeostasis.

  10. Breeding or Assisted Reproduction? Relevance of the Horse Model Applied to the Conservation of Endangered Equids

    NARCIS (Netherlands)

    Smits, K.; Hoogewijs, M.; Woelders, H.; Daels, P.; Soom, van A.

    2012-01-01

    Many wild equids are at present endangered in the wild. Concurrently, increased mechanization has pushed back the numbers of some old native horse breeds to levels that are no longer compatible with survival of the breed. Strong concerns arose in the last decade to preserve animal biodiversity,

  11. Implementing the Serial Number Tracking model in telecommunications: a case study of Croatia

    Directory of Open Access Journals (Sweden)

    Neven Polovina

    2012-01-01

    Full Text Available Background: The case study describes the implementation of the SNT (Serial Number Tracking model in an integrated information system, as a means of business support in a Croatian mobile telecommunications company. Objectives: The goal was to show how to make the best practice of the SNT implementation in the telecommunication industry, with referencing to problems which have arisen during the implementation. Methods/Approach: the case study approach was used based on the documentation about the SNT model and the business intelligence system in the Croatian mobile telecommunications company. Results: Economic aspects of the effectiveness of the SNT model are described and confirmed based on actual tangible and predominantly on intangible benefits. Conclusions: Advantages of the SNT model are multiple: operating costs for storage and transit of goods were reduced, accuracy of deliveries and physical inventory was improved; a new source of information for the business intelligence system was obtained; operating processes in the distribution of goods were advanced; transit insurance costs decreased and there were fewer cases of fraudulent behaviour.

  12. Network modeling of the transcriptional effects of copy number aberrations in glioblastoma

    Science.gov (United States)

    Jörnsten, Rebecka; Abenius, Tobias; Kling, Teresia; Schmidt, Linnéa; Johansson, Erik; Nordling, Torbjörn E M; Nordlander, Bodil; Sander, Chris; Gennemark, Peter; Funa, Keiko; Nilsson, Björn; Lindahl, Linda; Nelander, Sven

    2011-01-01

    DNA copy number aberrations (CNAs) are a hallmark of cancer genomes. However, little is known about how such changes affect global gene expression. We develop a modeling framework, EPoC (Endogenous Perturbation analysis of Cancer), to (1) detect disease-driving CNAs and their effect on target mRNA expression, and to (2) stratify cancer patients into long- and short-term survivors. Our method constructs causal network models of gene expression by combining genome-wide DNA- and RNA-level data. Prognostic scores are obtained from a singular value decomposition of the networks. By applying EPoC to glioblastoma data from The Cancer Genome Atlas consortium, we demonstrate that the resulting network models contain known disease-relevant hub genes, reveal interesting candidate hubs, and uncover predictors of patient survival. Targeted validations in four glioblastoma cell lines support selected predictions, and implicate the p53-interacting protein Necdin in suppressing glioblastoma cell growth. We conclude that large-scale network modeling of the effects of CNAs on gene expression may provide insights into the biology of human cancer. Free software in MATLAB and R is provided. PMID:21525872

  13. The use of multilevel models to evaluate sources of variation in reproductive performance in dairy cattle in Reunion Island

    DEFF Research Database (Denmark)

    Dohoo, I.R.; Tillard, E.; Stryhn, H.

    2001-01-01

    Sources of variation in measures of reproductive performance in dairy cattle were evaluated using data collected from 3207 lactations in 1570 cows in 50 herds from five geographic regions of Reunion Island (located off the cast coast of Madagascar). Three continuously distributed reproductive...

  14. Modeling the spatio-temporal dynamics of porcine reproductive & respiratory syndrome cases at farm level using geographical distance and pig trade network matrices.

    Science.gov (United States)

    Amirpour Haredasht, Sara; Polson, Dale; Main, Rodger; Lee, Kyuyoung; Holtkamp, Derald; Martínez-López, Beatriz

    2017-06-07

    Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically devastating infectious diseases for the swine industry. A better understanding of the disease dynamics and the transmission pathways under diverse epidemiological scenarios is a key for the successful PRRS control and elimination in endemic settings. In this paper we used a two step parameter-driven (PD) Bayesian approach to model the spatio-temporal dynamics of PRRS and predict the PRRS status on farm in subsequent time periods in an endemic setting in the US. For such purpose we used information from a production system with 124 pig sites that reported 237 PRRS cases from 2012 to 2015 and from which the pig trade network and geographical location of farms (i.e., distance was used as a proxy of airborne transmission) was available. We estimated five PD models with different weights namely: (i) geographical distance weight which contains the inverse distance between each pair of farms in kilometers, (ii) pig trade weight (PT ji ) which contains the absolute number of pig movements between each pair of farms, (iii) the product between the distance weight and the standardized relative pig trade weight, (iv) the product between the standardized distance weight and the standardized relative pig trade weight, and (v) the product of the distance weight and the pig trade weight. The model that included the pig trade weight matrix provided the best fit to model the dynamics of PRRS cases on a 6-month basis from 2012 to 2015 and was able to predict PRRS outbreaks in the subsequent time period with an area under the ROC curve (AUC) of 0.88 and the accuracy of 85% (105/124). The result of this study reinforces the importance of pig trade in PRRS transmission in the US. Methods and results of this study may be easily adapted to any production system to characterize the PRRS dynamics under diverse epidemic settings to more timely support decision-making.

  15. A multi-model assessment of the impact of sea spray geoengineering on cloud droplet number

    Directory of Open Access Journals (Sweden)

    K. J. Pringle

    2012-12-01

    Full Text Available Artificially increasing the albedo of marine boundary layer clouds by the mechanical emission of sea spray aerosol has been proposed as a geoengineering technique to slow the warming caused by anthropogenic greenhouse gases. A previous global model study (Korhonen et al., 2010 found that only modest increases (< 20% and sometimes even decreases in cloud drop number (CDN concentrations would result from emission scenarios calculated using a windspeed dependent geoengineering flux parameterisation. Here we extend that work to examine the conditions under which decreases in CDN can occur, and use three independent global models to quantify maximum achievable CDN changes. We find that decreases in CDN can occur when at least three of the following conditions are met: the injected particle number is < 100 cm−3, the injected diameter is > 250–300 nm, the background aerosol loading is large (≥ 150 cm−3 and the in-cloud updraught velocity is low (< 0.2 m s−1. With lower background loadings and/or increased updraught velocity, significant increases in CDN can be achieved. None of the global models predict a decrease in CDN as a result of geoengineering, although there is considerable diversity in the calculated efficiency of geoengineering, which arises from the diversity in the simulated marine aerosol distributions. All three models show a small dependence of geoengineering efficiency on the injected particle size and the geometric standard deviation of the injected mode. However, the achievability of significant cloud drop enhancements is strongly dependent on the cloud updraught speed. With an updraught speed of 0.1 m s−1 a global mean CDN of 375 cm−3 (previously estimated to cancel the forcing caused by CO2 doubling is achievable in only about 50% of grid boxes which have > 50% cloud cover, irrespective of the amount of aerosol injected. But at stronger updraft speeds (0

  16. Reproduction of the model of plateau hypoxia in different degrees in gestational sheep

    Directory of Open Access Journals (Sweden)

    Jie HU

    2015-06-01

    Full Text Available Objective To reproduce the model of plateau hypoxia in different degrees in pregnant sheep by using hypobaric chamber for the evaluation of oxygenation status and oxidative damage in these models. Methods Twenty-four pregnant sheep conceived by successful artificial insemination were randomly divided into three groups (8 each: low altitude control group (LAC, mild hypoxia exposure group (MHE and severe hypoxia exposure group (SHE. Sheep in the latter two groups were fed in hypobaric chamber, and the models were reproduced by adjusting the temperature, humidity, pressure and oxygen content simulating environment of different altitudes of northwest China. The degree of oxygenation, vital signs, behavior pattern and oxidative damage biomarkers were dynamically determined before modeling and 7, 15, 30, 90, 120 days after modeling, respectively. Results Thirty and 90 days after modeling, the arterial blood gas parameters of sheep in MHE and SHE group met the diagnostic criteria. Ninety days after modeling, the respiratory frequency decreased (P<0.05, the heart rate increased (P<0.05, and lassitude were found in MHE and SHE groups than in LAC group; the consumption of feeding decreased in SHE group than in MHE group (P<0.05. One hundred and twenty days after modeling, the CO and MDA increased significantly in MHE and SHE groups than those in LAC group (P<0.05, also in SHE group compared with that in MHE group (P<0.05. Conclusion Different degrees of hypoxia models of pregnant sheep have been successfully reproduced by using hypobaric chamber, and the results showed that the hypoxic environment in high altitude regions may cause oxidative stress injury of gestational sheep. DOI: 10.11855/j.issn.0577-7402.2015.05.05

  17. Reproductive endocrinology of Syngnathidae.

    Science.gov (United States)

    Scobell, S K; Mackenzie, D S

    2011-06-01

    Few studies have examined the underlying hormonal mechanisms that mediate reproductive cyclicity, male pregnancy and reproductive behaviour in syngnathids. Progress in these areas has been hampered by the small size of most species in the family and a lack of validated techniques for assessing endocrine function. Research on a relatively small number of species has suggested that androgens are likely regulators of spermatogenesis and the development of the male brood pouch prior to pregnancy whereas prolactin and corticosteroids synergistically promote brood pouch function during pregnancy. No evidence supports a reversal of reproductive steroid hormone function in sex-role reversed behaviour, but neuropeptides such as arginine vasotocin or isotocin should be examined for their role in regulating parturition and mating behaviour. The diversity of reproductive patterns exhibited by syngnathids suggests that they will provide a unique opportunity to assess how hormonal regulation of integumentary function, gametogenesis and reproductive behaviour have evolved within a teleost lineage. Additionally, their coastal distribution and embryo retention make them potentially important subjects for studies on the effect of endocrine disruption on fitness. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

  18. Reproductive epidemiology

    DEFF Research Database (Denmark)

    Olsen, Jørn; Nøhr, Ellen Aagaard

    2010-01-01

    Reproductive health covers a broad category of health and disease conditions, according to the Cairo Statement. This chapter focuses on subfecundity fertility, fetal death, malformations, pregnancy complications, sexual health, and diseases that may have their origin in fetal life, but which will...

  19. THE ANTICIPATION OF THE NUMBER OF TOURISTS ARRIVED IN MAMAIA USING THE TYPE OF MODELS ARIMA

    Directory of Open Access Journals (Sweden)

    Kamer Ainur M. AIVAZ

    2016-06-01

    Full Text Available The Mamaia station is, at the moment, the biggest and the most looked for touristic station from the Romanian seaside of the Black Sea. From the analysis of the evolution of the main indicators of touristic circulation from the last 10 years (2006-2015, we can notice a significant increase, but we are also interested in knowing the tendency of their modification in the near future. For this reason, in the present study, we wanted to test the contribution of the models ARIMA to the elaboration of an anticipation regarding the indicators: arrivals of tourists, totally and structurally: Romanians and foreigners, for Mamaia station. We consider that the results obtained in this study may contribute to the defining of the strategy of development of the station and ensuring the necessary conditions for hosting a significant greater number of tourists, in the following years.

  20. A Novel Letrozole Model Recapitulates Both the Reproductive and Metabolic Phenotypes of Polycystic Ovary Syndrome in Female Mice1

    Science.gov (United States)

    Kauffman, Alexander S.; Thackray, Varykina G.; Ryan, Genevieve E.; Tolson, Kristen P.; Glidewell-Kenney, Christine A.; Semaan, Sheila J.; Poling, Matthew C.; Iwata, Nahoko; Breen, Kellie M.; Duleba, Antoni J.; Stener-Victorin, Elisabet; Shimasaki, Shunichi; Webster, Nicholas J.; Mellon, Pamela L.

    2015-01-01

    Polycystic ovary syndrome (PCOS) pathophysiology is poorly understood, due partly to lack of PCOS animal models fully recapitulating this complex disorder. Recently, a PCOS rat model using letrozole (LET), a nonsteroidal aromatase inhibitor, mimicked multiple PCOS phenotypes, including metabolic features absent in other models. Given the advantages of using genetic and transgenic mouse models, we investigated whether LET produces a similar PCOS phenotype in mice. Pubertal female C57BL/6N mice were treated for 5 wk with LET, which resulted in increased serum testosterone and normal diestrus levels of estradiol, similar to the hyperandrogenemia and follicular phase estrogen levels of PCOS women. As in PCOS, ovaries from LET mice were larger, polycystic, and lacked corpora lutea versus controls. Most LET females were acyclic, and all were infertile. LET females displayed elevated serum LH levels and higher Lhb mRNA in the pituitary. In contrast, serum FSH and Fshb were significantly reduced in LET females, demonstrating differential effects on gonadotropins, as in PCOS. Within the ovary, LET females had higher Cyp17, Cyp19, and Fsh receptor mRNA expression. In the hypothalamus, LET females had higher kisspeptin receptor mRNA expression but lower progesterone receptor mRNA levels. LET females also gained more weight than controls, had increased abdominal adiposity and adipocyte size, elevated adipose inflammatory mRNA levels, and impaired glucose tolerance, mirroring the metabolic phenotype in PCOS women. This is the first report of a LET paradigm in mice that recapitulates both reproductive and metabolic PCOS phenotypes and will be useful to genetically probe the PCOS condition. PMID:26203175

  1. Genotype copy number variations using Gaussian mixture models: theory and algorithms.

    Science.gov (United States)

    Lin, Chang-Yun; Lo, Yungtai; Ye, Kenny Q

    2012-10-12

    Copy number variations (CNVs) are important in the disease association studies and are usually targeted by most recent microarray platforms developed for GWAS studies. However, the probes targeting the same CNV regions could vary greatly in performance, with some of the probes carrying little information more than pure noise. In this paper, we investigate how to best combine measurements of multiple probes to estimate copy numbers of individuals under the framework of Gaussian mixture model (GMM). First we show that under two regularity conditions and assume all the parameters except the mixing proportions are known, optimal weights can be obtained so that the univariate GMM based on the weighted average gives the exactly the same classification as the multivariate GMM does. We then developed an algorithm that iteratively estimates the parameters and obtains the optimal weights, and uses them for classification. The algorithm performs well on simulation data and two sets of real data, which shows clear advantage over classification based on the equal weighted average.

  2. Modeling energy and reproductive costs in caribou exposed to low flying military jet aircraft

    Directory of Open Access Journals (Sweden)

    B.R. Luick

    1996-01-01

    Full Text Available We used simulation modeling to estimate the effect of low-flying military jet aircraft on the productivity of caribou. The base model (CARIBOU, CWS Whitehorse, Yukon Territory uses daily intake and expenditure of energy to assess the condition of female caribou throughout the annual cycle. The activity budget of the model caribou was adjusted based on field observations of responses to noise disturbance. A subroutine was added that predicted the likelihood of conception based on fall body fat weight. Caribou responses to overflights were evaluated by equipping free-ranging caribou with radio collars and activity sensors that could distinguish between resting and active periods. Collared animals were exposed to 110 overflights by A-10, F-15 and F- 16 jet aircraft during late-winter, post-calving and the insect season. Noise exposure levels for individual animals either were measured directly with collar-mounted dosimeters or were estimated based on the proximity of the caribou to the aircraft during the overflight. A Time-averaged Sound Level (LT was calculated from the total daily noise exposure for each animal and linear regression was used to evaluate the influence of daily noise exposure on daily hours spent resting. Results of these analyses then were used to modify the time budgets in the CARIBOU model. That is, if time spent resting declined, then time spent in the two rest classes (lying and standing were proportionately redistributed into the three active classes (foraging, walking and running. Model simulations indicated that caribou increased forage intake in response to increased noise exposure, but it also predicted that increased noise exposure would cause a reduced accumulation of body fat. Because body fat in fall has successfully been used to predict the probability of pregnancy (see Gerhart et al, 1993, this relationship was used in the model. Preliminary model simulations indicate that increased noise exposure decreases the

  3. Flower diversity and bee reproduction in an arid ecosystem

    Directory of Open Access Journals (Sweden)

    Jimena Dorado

    2016-07-01

    Full Text Available Background: Diverse flower communities are more stable in floral resource production along the flowering season, but the question about how the diversity and stability of resources affect pollinator reproduction remains open. High plant diversity could favor short foraging trips, which in turn would enhance bee fitness. In addition to plant diversity, greater temporal stability of floral resources in diverse communities could favor pollinator fitness because such communities are likely to occupy the phenological space more broadly, increasing floral availability for pollinators throughout the season. In addition, this potential effect of flower diversity on bee reproduction could be stronger for generalist pollinators because they can use a broader floral spectrum. Based on above arguments we predicted that pollinator reproduction would be positively correlated to flower diversity, and to temporal stability in flower production, and that this relationship would be stronger for the most generalized pollinator species. Materials and Methods: Using structural equation models, we evaluated the effect of these variables and other ecological factors on three estimates of bee reproduction (average number of brood cells per nest per site, total number of brood cells per site, and total number of nests per site, and whether such effects were modulated by bee generalization on floral resources. Results: Contrary to our expectations, flower diversity had no effect on bee reproduction, stability in flower production had a weakly negative effect on one of the bee reproductive variables, and the strength of the fitness-diversity relationship was unrelated to bee generalization. In contrast, elevation had a negative effect on bee reproduction, despite the narrow elevation range encompassed by our sites. Discussion: Flower diversity did not affect the reproduction of the solitary bees studied here. This result could stem from the context dependence of the

  4. A Poisson hierarchical modelling approach to detecting copy number variation in sequence coverage data

    KAUST Repository

    Sepúlveda, Nuno

    2013-02-26

    Background: The advent of next generation sequencing technology has accelerated efforts to map and catalogue copy number variation (CNV) in genomes of important micro-organisms for public health. A typical analysis of the sequence data involves mapping reads onto a reference genome, calculating the respective coverage, and detecting regions with too-low or too-high coverage (deletions and amplifications, respectively). Current CNV detection methods rely on statistical assumptions (e.g., a Poisson model) that may not hold in general, or require fine-tuning the underlying algorithms to detect known hits. We propose a new CNV detection methodology based on two Poisson hierarchical models, the Poisson-Gamma and Poisson-Lognormal, with the advantage of being sufficiently flexible to describe different data patterns, whilst robust against deviations from the often assumed Poisson model.Results: Using sequence coverage data of 7 Plasmodium falciparum malaria genomes (3D7 reference strain, HB3, DD2, 7G8, GB4, OX005, and OX006), we showed that empirical coverage distributions are intrinsically asymmetric and overdispersed in relation to the Poisson model. We also demonstrated a low baseline false positive rate for the proposed methodology using 3D7 resequencing data and simulation. When applied to the non-reference isolate data, our approach detected known CNV hits, including an amplification of the PfMDR1 locus in DD2 and a large deletion in the CLAG3.2 gene in GB4, and putative novel CNV regions. When compared to the recently available FREEC and cn.MOPS approaches, our findings were more concordant with putative hits from the highest quality array data for the 7G8 and GB4 isolates.Conclusions: In summary, the proposed methodology brings an increase in flexibility, robustness, accuracy and statistical rigour to CNV detection using sequence coverage data. 2013 Seplveda et al.; licensee BioMed Central Ltd.

  5. Variance of the number of tumors in a model for the induction of osteosarcoma by alpha radiation

    International Nuclear Information System (INIS)

    Groer, P.G.; Marshall, J.H.

    1976-01-01

    An earlier report on a model for the induction of osteosarcoma by alpha radiation gave differential equations for the mean numbers of normal, transformed, and malignant cells. In this report we show that for a constant dose rate the variance of the number of cells at each stage and time is equal to the corresponding mean, so the numbers of tumors predicted by the model have a Poisson distribution about their mean values

  6. Male Reproductive System

    Science.gov (United States)

    ... Videos for Educators Search English Español Male Reproductive System KidsHealth / For Parents / Male Reproductive System What's in ... your son's reproductive health. About the Male Reproductive System Most species have two sexes: male and female. ...

  7. An Optimization Model for Design of Asphalt Pavements Based on IHAP Code Number 234

    Directory of Open Access Journals (Sweden)

    Ali Reza Ghanizadeh

    2016-01-01

    Full Text Available Pavement construction is one of the most costly parts of transportation infrastructures. Incommensurate design and construction of pavements, in addition to the loss of the initial investment, would impose indirect costs to the road users and reduce road safety. This paper aims to propose an optimization model to determine the optimal configuration as well as the optimum thickness of different pavement layers based on the Iran Highway Asphalt Paving Code Number 234 (IHAP Code 234. After developing the optimization model, the optimum thickness of pavement layers for secondary rural roads, major rural roads, and freeways was determined based on the recommended prices in “Basic Price List for Road, Runway and Railway” of Iran in 2015 and several charts were developed to determine the optimum thickness of pavement layers including asphalt concrete, granular base, and granular subbase with respect to road classification, design traffic, and resilient modulus of subgrade. Design charts confirm that in the current situation (material prices in 2015, application of asphalt treated layer in pavement structure is not cost effective. Also it was shown that, with increasing the strength of subgrade soil, the subbase layer may be removed from the optimum structure of pavement.

  8. Efficiency evaluation of a small number of DMUs: an approach based on Li and Reeves's model

    Directory of Open Access Journals (Sweden)

    João Carlos Correia Baptista Soares de Mello

    2009-04-01

    Full Text Available This paper deals with the evaluation of Decision Making Units (DMU when their number is not large enough to allow the use of classic Data Envelopment Analysis (DEA models. To do so, we take advantage of the TRIMAP software when used to study the Li and Reeves MultiCriteria DEA (MCDEA model. We introduce an evaluation measure obtained with the integration of one of the objective functions along the weight space. This measure allows the DMUs joint evaluation. This approach is exemplified with numerical data from some Brazilian electrical companies.Este artigo trata da avaliação de Unidades Produtivas (Decision Making Units - DMUs quando seu número é inferior ao recomendado na Análise Envoltória de Dados (Data Envelopment Analysis - DEA. Para isso é explorado o uso do software TRIMAP no modelo MCDEA (MultiCriteria DEA de Li e Reeves. É proposto um índice de avaliação de desempenho baseado nos valores assumidos por uma das funções objetivo do modelo MCDEA. Estes valores, obtidos pelo TRIMAP, são integrados ao longo de todo o espaço dos pesos. O índice obtido permite uma avaliação de conjunto das DMUs avaliadas. O modelo é ilustrado com um exemplo numérico de avaliação de empresas distribuidoras de energia elétrica.

  9. Use of medaka (Oryzias latipes) as a model teleost to identify reproductive endpoints indicative of exposure to endocrine disrupting chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Papoulias, D.M.; Tillitt, D.; Jones, S. [National Biological Service, Columbia, MO (United States); Noltie, D. [Univ. of Missouri, Columbia, MO (United States)

    1995-12-31

    The purpose of this research is to identify effects of endocrine disrupting chemicals on the reproductive system of fish at various stages of sexual differentiation and development. The model teleost used was the d-rR strain of medaka (Oryzias latipes) which has a heritable sex-linked color gene. In medaka, sex differences are first detected at the cellular level at hatch. In males, the mitotic activity of the primordial germ cells (PGC) is arrested while the PGCs of the females continue to divide. The germ cells of the gonochoristic medaka have been demonstrated to be totipotent with respective to gonia production. Because endogenous sex steroid hormones are believed to regulate this early process of sexual differentiation, the authors have hypothesized that mitotic activity in males and females exposed to endocrine disrupting chemicals will be different than unexposed individuals. Results are presented for tests conducted by injecting medaka eggs within 36 hours post-hatch with 3 doses of 2,3,7,8-TCDD (nominally 2.3, 1.3, 0.2 pg/embryo), a known anti-estrogen, dissolved in triolein.

  10. Maternal investment in reproduction and its consequences in leatherback turtles.

    Science.gov (United States)

    Wallace, Bryan P; Sotherland, Paul R; Tomillo, Pilar Santidrian; Reina, Richard D; Spotila, James R; Paladino, Frank V

    2007-05-01

    Maternal investment in reproduction by oviparous non-avian reptiles is usually limited to pre-ovipositional allocations to the number and size of eggs and clutches, thus making these species good subjects for testing hypotheses of reproductive optimality models. Because leatherback turtles (Dermochelys coriacea) stand out among oviparous amniotes by having the highest clutch frequency and producing the largest mass of eggs per reproductive season, we quantified maternal investment of 146 female leatherbacks over four nesting seasons (2001-2004) and found high inter- and intra-female variation in several reproductive characteristics. Estimated clutch frequency [coefficient of variation (CV) = 31%] and clutch size (CV = 26%) varied more among females than did egg mass (CV = 9%) and hatchling mass (CV = 7%). Moreover, clutch size had an approximately threefold higher effect on clutch mass than did egg mass. These results generally support predictions of reproductive optimality models in which species that lay several, large clutches per reproductive season should exhibit low variation in egg size and instead maximize egg number (clutch frequency and/or size). The number of hatchlings emerging per nest was positively correlated with clutch size, but fraction of eggs in a clutch yielding hatchlings (emergence success) was not correlated with clutch size and varied highly among females. In addition, seasonal fecundity and seasonal hatchling production increased with the frequency and the size of clutches (in order of effect size). Our results demonstrate that female leatherbacks exhibit high phenotypic variation in reproductive traits, possibly in response to environmental variability and/or resulting from genotypic variability within the population. Furthermore, high seasonal and lifetime fecundity of leatherbacks probably reflect compensation for high and unpredictable mortality during early life history stages in this species.

  11. Navigating the complexities of qualitative comparative analysis: case numbers, necessity relations, and model ambiguities.

    Science.gov (United States)

    Thiem, Alrik

    2014-12-01

    In recent years, the method of Qualitative Comparative Analysis (QCA) has been enjoying increasing levels of popularity in evaluation and directly neighboring fields. Its holistic approach to causal data analysis resonates with researchers whose theories posit complex conjunctions of conditions and events. However, due to QCA's relative immaturity, some of its technicalities and objectives have not yet been well understood. In this article, I seek to raise awareness of six pitfalls of employing QCA with regard to the following three central aspects: case numbers, necessity relations, and model ambiguities. Most importantly, I argue that case numbers are irrelevant to the methodological choice of QCA or any of its variants, that necessity is not as simple a concept as it has been suggested by many methodologists, and that doubt must be cast on the determinacy of virtually all results presented in past QCA research. By means of empirical examples from published articles, I explain the background of these pitfalls and introduce appropriate procedures, partly with reference to current software, that help avoid them. QCA carries great potential for scholars in evaluation and directly neighboring areas interested in the analysis of complex dependencies in configurational data. If users beware of the pitfalls introduced in this article, and if they avoid mechanistic adherence to doubtful "standards of good practice" at this stage of development, then research with QCA will gain in quality, as a result of which a more solid foundation for cumulative knowledge generation and well-informed policy decisions will also be created. © The Author(s) 2014.

  12. Long-term impacts of selective logging on two Amazonian tree species with contrasting ecological and reproductive characteristics: inferences from Eco-gene model simulations.

    Science.gov (United States)

    Vinson, C C; Kanashiro, M; Sebbenn, A M; Williams, T C R; Harris, S A; Boshier, D H

    2015-08-01

    The impact of logging and subsequent recovery after logging is predicted to vary depending on specific life history traits of the logged species. The Eco-gene simulation model was used to evaluate the long-term impacts of selective logging over 300 years on two contrasting Brazilian Amazon tree species, Dipteryx odorata and Jacaranda copaia. D. odorata (Leguminosae), a slow growing climax tree, occurs at very low densities, whereas J. copaia (Bignoniaceae) is a fast growing pioneer tree that occurs at high densities. Microsatellite multilocus genotypes of the pre-logging populations were used as data inputs for the Eco-gene model and post-logging genetic data was used to verify the output from the simulations. Overall, under current Brazilian forest management regulations, there were neither short nor long-term impacts on J. copaia. By contrast, D. odorata cannot be sustainably logged under current regulations, a sustainable scenario was achieved by increasing the minimum cutting diameter at breast height from 50 to 100 cm over 30-year logging cycles. Genetic parameters were only slightly affected by selective logging, with reductions in the numbers of alleles and single genotypes. In the short term, the loss of alleles seen in J. copaia simulations was the same as in real data, whereas fewer alleles were lost in D. odorata simulations than in the field. The different impacts and periods of recovery for each species support the idea that ecological and genetic information are essential at species, ecological guild or reproductive group levels to help derive sustainable management scenarios for tropical forests.

  13. Reproduction of a model of lung injury induced by depleted uranium inhalation in canine

    Directory of Open Access Journals (Sweden)

    Bin ZHANG

    2011-02-01

    Full Text Available Objective To reproduce a canine model of subacute lung injury induced by depleted uranium inhalation.Methods Twenty-six dogs were randomized into the control group(CG,n=6,low-dose group(LG,n=10.and high-dose group(HG,n=10.All of them underwent tracheal intubation.In control group,0.2ml/kg of normal saline was intratracheally given.In low dosage group,10mg/kg of depleted uranium(LG,and in high dose group 100mg/ml of depleted uranium(HG was introduced.The survival time of animals was observed in one month after intratracheal introduction of various agents,and chest CT scan was performed in the survived animals.They were sacrificed for pathological examination of lung tissues on the 31st day post of them intratracheal introduction of various agents.Results During the observation period,no animal died in CG,one dog in LG died on the 22nd day and 9 of them survived longer than 30 days.All the animals in HG group died within 30 days with a mean survival time of 11.2±8.9 days(median=12d.In comparison with the HG,significant difference on survival time was found between LG and CG,while no significant difference was found between the latter 2 groups(P=0.439.Pathologically,changes were noted in lung tissue of LG,such as escape of inflammatory cells into alveoli,hemorrhage and hyaline membrane formation in alveolar space,dilatation and congestion of alveolar capillaries,and infiltration of inflammatory cells in interstitial tissue.CT scanning revealed patchy effusion and solid consolidation in the left lung.Conclusion The canine model of subacute lung injury induced by a dose of 2mg/kg depleted uranium introduced through tracheal intubation is suitable for the study of subacute toxicity induced by depleted uranium.

  14. Quantitative analysis of porcine reproductive and respiratory syndrome (PRRS) viremia profiles from experimental infection: a statistical modelling approach.

    Science.gov (United States)

    Islam, Zeenath U; Bishop, Stephen C; Savill, Nicholas J; Rowland, Raymond R R; Lunney, Joan K; Trible, Benjamin; Doeschl-Wilson, Andrea B

    2013-01-01

    Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically significant viral diseases facing the global swine industry. Viremia profiles of PRRS virus challenged pigs reflect the severity and progression of infection within the host and provide crucial information for subsequent control measures. In this study we analyse the largest longitudinal PRRS viremia dataset from an in-vivo experiment. The primary objective was to provide a suitable mathematical description of all viremia profiles with biologically meaningful parameters for quantitative analysis of profile characteristics. The Wood's function, a gamma-type function, and a biphasic extended Wood's function were fit to the individual profiles using Bayesian inference with a likelihood framework. Using maximum likelihood inference and numerous fit criteria, we established that the broad spectrum of viremia trends could be adequately represented by either uni- or biphasic Wood's functions. Three viremic categories emerged: cleared (uni-modal and below detection within 42 days post infection(dpi)), persistent (transient experimental persistence over 42 dpi) and rebound (biphasic within 42 dpi). The convenient biological interpretation of the model parameters estimates, allowed us not only to quantify inter-host variation, but also to establish common viremia curve characteristics and their predictability. Statistical analysis of the profile characteristics revealed that persistent profiles were distinguishable already within the first 21 dpi, whereas it is not possible to predict the onset of viremia rebound. Analysis of the neutralizing antibody(nAb) data indicated that there was a ubiquitous strong response to the homologous PRRSV challenge, but high variability in the range of cross-protection of the nAbs. Persistent pigs were found to have a significantly higher nAb cross-protectivity than pigs that either cleared viremia or experienced rebound within 42 dpi. Our study provides

  15. Experimental reproduction of tumbleweed shield lichen (Xanthoparmelia chlorochroa) poisoning in a domestic sheep model.

    Science.gov (United States)

    Dailey, Rebecca N; Montgomery, Donald L; Ingram, James T; Siemion, Roger; Raisbeck, Merl F

    2008-11-01

    Xanthoparmelia chlorochroa, commonly called tumbleweed lichen, is found throughout the Rocky Mountain region. This particular species of lichen was incriminated in the poisoning of cattle and sheep in Wyoming during the 1930s. More than 70 years elapsed before another case was reported. There is virtually no information in the veterinary literature regarding toxicity of this lichen. This report describes X. chlorochroa poisoning in domestic sheep fed lichen collected from different locales and at different times of the year. Affected animals voided red urine and displayed incoordination. A transient spike in serum creatine kinase activity occurred in all ewes during the course of the feeding trial. Histologically, necrosis of a few individual appendicular skeletal myocytes was observed in 1 ewe, but grossly discernible myonecrosis was absent. The severity of clinical signs varied depending on the location and/or time of year the lichen was collected, indicating that toxicity of the lichen may be influenced by environmental conditions. Results demonstrate that domestic sheep are a useful model for further investigation of X. chlorochroa intoxication. The current study should act as a starting point for elucidating the pathogenesis of X. chlorochroa poisoning and aid in the development of a diagnostic assay to confirm lichen poisoning.

  16. Utilizing a rat delayed implantation model to teach integrative endocrinology and reproductive biology.

    Science.gov (United States)

    Geisert, Rodney D; Smith, Michael F; Schmelzle, Amanda L; Green, Jonathan A

    2018-03-01

    In this teaching laboratory, the students are directed in an exercise that involves designing and performing an experiment to determine estrogen's role in regulating delayed implantation (diapause) in female rats. To encourage active participation by the students, a discussion question is provided before the laboratory exercise in which each student is asked to search the literature and provide written answers to questions and to formulate an experiment to test the role of ovarian estrogen in inducing implantation in female rats. One week before the laboratory exercise, students discuss their answers to the questions with the instructor to develop an experiment to test their hypothesis that estrogen is involved with inducing implantation in the rat. A rat delayed implantation model was established that utilizes an estrogen receptor antagonist (ICI 182,780), which inhibits the action of ovarian estrogens. Groups of mated females are treated with either carrier (control) or ICI 182,780 (ICI) every other day, starting on day 2 postcoitus (pc) until day 8 pc. One-half of the females receiving ICI are injected with estradiol-17β on day 8 pc to induce implantation 4 days after the controls. If the ICI-treated females are not administered estradiol, embryo implantation occurs spontaneously ~4 days after the last ICI injection on day 8. This is a very simple protocol that is very effective and provides an excellent experiment for student discussion on hormone action and the use of agonists and antagonists.

  17. Systems Toxicology of Male Reproductive Development ...

    Science.gov (United States)

    Adverse trends in male reproductive health have been reported for increased rates of testicular germ cell tumor, low semen quality, cryptorchidism, and hypospadias. An association with prenatal environmental exposure has been inferred from human and animal studies underlying male reproductive developmental defects. The present study established the links between environmental chemicals, molecular targets, and adverse outcomes using U.S. EPA animal study (ToxRefDB) and high-throughput screening (ToxCast) databases. This systems-based approach revealed a phenotypic hierarchy across 63 chemicals and a pleiotropic in vitro bioactivity profile. Although estrogenic and anti-androgenic activities have been extensively studied in male reproductive developmental toxicity, the present study showed these receptor targets to be only a subset of the potential landscape of molecular targets. A variety of chemical (e.g. phthalates, conazoles, carbamates, and phenol compounds) and bioactivity (e.g. nuclear receptors, vascular remodeling proteins, and cytochrome-P450 reductases) clusters further suggested multiple pathways leading to the adverse outcomes. This points to the need for multi-scale systems models to predict whether the occurrence of one adverse outcome may predict the risk of another. Imbalances in androgen and estrogen signaling have been a general focus in male reproductive toxicology research. While a number of recent studies have demonstrated that both hormonal

  18. Rethinking reproductive "tourism" as reproductive "exile".

    Science.gov (United States)

    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.

  19. Women Reproductive Rights in India: Prospective Future

    Directory of Open Access Journals (Sweden)

    Srinivas Kosgi

    2011-04-01

    Full Text Available Reproductive rights were established as a subset of the human rights. Parents have a basic human right to determine freely and responsibly the number and the spacing of their children. Issues regarding the reproductive rights are vigorously contested, regardless of the population’s socioeconomic level, religion or culture. Following review article discusses reproductive rights with respect to Indian context focusing on socio economic and cultural aspects. Also discusses sensitization of government and judicial agencies in protecting the reproductive rights with special focus on the protecting the reproductive rights of people with disability (mental illness and mental retardation.

  20. The effect of a number of selective points in modeling of polymerization reacting Monte Carlo method: studying the initiation reaction

    CERN Document Server

    Sadi, M; Dabir, B

    2003-01-01

    Monte Carlo Method is one of the most powerful techniques to model different processes, such as polymerization reactions. By this method, without any need to solve moment equations, a very detailed information on the structure and properties of polymers are obtained. The number of algorithm repetitions (selected volumes of reactor for modelling which represent the number of initial molecules) is very important in this method. In Monte Carlo method calculations are based on the random number of generations and reaction probability determinations. so the number of algorithm repetition is very important. In this paper, the initiation reaction was considered alone and the importance of number of initiator molecules on the result were studied. It can be concluded that Monte Carlo method will not give accurate results if the number of molecules is not satisfied to be big enough, because in that case , selected volume would not be representative of the whole system.

  1. Simulation of between-farm transmission of porcine reproductive and respiratory syndrome virus in Ontario, Canada using the North American Animal Disease Spread Model.

    Science.gov (United States)

    Thakur, Krishna K; Revie, Crawford W; Hurnik, Daniel; Poljak, Zvonimir; Sanchez, Javier

    2015-03-01

    Porcine reproductive and respiratory syndrome (PRRS), a viral disease of swine, has major economic impacts on the swine industry. The North American Animal Disease Spread Model (NAADSM) is a spatial, stochastic, farm level state-transition modeling framework originally developed to simulate highly contagious and foreign livestock diseases. The objectives of this study were to develop a model to simulate between-farm spread of a homologous strain of PRRS virus in Ontario swine farms via direct (animal movement) and indirect (sharing of trucks between farms) contacts using the NAADSM and to compare the patterns and extent of outbreak under different simulated conditions. A total of 2552 swine farms in Ontario province were allocated to each census division of Ontario and geo-locations of the farms were randomly generated within the agriculture land of each Census Division. Contact rates among different production types were obtained using pig movement information from four regions in Canada. A total of 24 scenarios were developed involving various direct (movement of infected animals) and indirect (pig transportation trucks) contact parameters in combination with alternating the production type of the farm in which the infection was seeded. Outbreaks were simulated for one year with 1000 replications. The median number of farms infected, proportion of farms with multiple outbreaks and time to reach the peak epidemic were used to compare the size, progression and extent of outbreaks. Scenarios involving spread only by direct contact between farms resulted in outbreaks where the median percentage of infected farms ranged from 31.5 to 37% of all farms. In scenarios with both direct and indirect contact, the median percentage of infected farms increased to a range from 41.6 to 48.6%. Furthermore, scenarios with both direct and indirect contact resulted in a 44% increase in median epidemic size when compared to the direct contact scenarios. Incorporation of both animal

  2. Estimating quasi-loglinear models for a Rasch table if the numbers of items is large

    NARCIS (Netherlands)

    Kelderman, Henk

    1987-01-01

    The Rasch Model and various extensions of this model can be formulated as a quasi loglinear model for the incomplete subgroup x score x item response 1 x ... x item response k contingency table. By comparing various loglinear models, specific deviations of the Rasch model can be tested. Parameter

  3. Numerical Investigation of Transitional Flow over a Backward Facing Step Using a Low Reynolds Number k-ε Model

    DEFF Research Database (Denmark)

    Skovgaard, M.; Nielsen, Peter V.

    In this paper it is investigated if it is possible to simulate and capture some of the low Reynolds number effects numerically using time averaged momentum equations and a low Reynolds number k-f model. The test case is the larninar to turbulent transitional flow over a backward facing step...

  4. Growth and reproductive effects from dietary exposure to Aroclor 1268 in mink (Neovison vison), a surrogate model for marine mammals.

    Science.gov (United States)

    Folland, William R; Newsted, John L; Fitzgerald, Scott D; Fuchsman, Phyllis C; Bradley, Patrick W; Kern, John; Kannan, Kurunthachalam; Remington, Richard E; Zwiernik, Matthew J

    2016-03-01

    Polychlorinated biphenyls (PCBs) from the commercial mixture Aroclor 1268 were historically released into the Turtle-Brunswick River estuary (southeastern Georgia, USA) from industrial operations. Sum PCBs (ΣPCBs) in blubber samples from Turtle-Brunswick River estuary bottlenose dolphins (Tursiops truncatus) have been reported at concentrations more than 10-fold higher than those observed in dolphins from adjacent regional estuaries. Given that toxicity data specific to Aroclor 1268 and applicable to marine mammals are limited, predicting the toxic effects of Aroclor 1268 in dolphins is uncertain, particularly because of its unique congener profile and associated physiochemical characteristics compared with other PCB mixtures. American mink (Neovison vison) were chosen as a surrogate model for cetaceans to develop marine mammalian PCB toxicity benchmarks. Mink are a suitable surrogate species for cetaceans in toxicity studies because of similarities in diet and taxonomic class, and a characteristic sensitivity to PCBs provides a potential safety factor when using mink toxicology data for cross-species extrapolations. Effects of dietary exposure to Aroclor 1268 on reproduction, growth, and mortality in mink were compared with both a negative control and a positive control (3,3',4,4',5-pentachlorobiphenyl, PCB 126). Aroclor 1268 dietary ΣPCB concentrations ranged from 1.8 µg/g feed wet weight to 29 µg/g feed wet weight. Whelp success was unaffected by Aroclor 1268 exposure at any level. Treatment mean litter size, kit growth, and kit survival were adversely affected relative to the negative control at dietary ΣPCB concentrations of 10.6 µg/g feed wet weight and greater. © 2015 SETAC.

  5. Discovering Genes Essential to the Hypothalamic Regulation of Human Reproduction Using a Human Disease Model: Adjusting to Life in the "-Omics" Era.

    Science.gov (United States)

    Stamou, M I; Cox, K H; Crowley, William F

    2016-02-01

    The neuroendocrine regulation of reproduction is an intricate process requiring the exquisite coordination of an assortment of cellular networks, all converging on the GnRH neurons. These neurons have a complex life history, migrating mainly from the olfactory placode into the hypothalamus, where GnRH is secreted and acts as the master regulator of the hypothalamic-pituitary-gonadal axis. Much of what we know about the biology of the GnRH neurons has been aided by discoveries made using the human disease model of isolated GnRH deficiency (IGD), a family of rare Mendelian disorders that share a common failure of secretion and/or action of GnRH causing hypogonadotropic hypogonadism. Over the last 30 years, research groups around the world have been investigating the genetic basis of IGD using different strategies based on complex cases that harbor structural abnormalities or single pleiotropic genes, endogamous pedigrees, candidate gene approaches as well as pathway gene analyses. Although such traditional approaches, based on well-validated tools, have been critical to establish the field, new strategies, such as next-generation sequencing, are now providing speed and robustness, but also revealing a surprising number of variants in known IGD genes in both patients and healthy controls. Thus, before the field moves forward with new genetic tools and continues discovery efforts, we must reassess what we know about IGD genetics and prepare to hold our work to a different standard. The purpose of this review is to: 1) look back at the strategies used to discover the "known" genes implicated in the rare forms of IGD; 2) examine the strengths and weaknesses of the methodologies used to validate genetic variation; 3)substantiate the role of known genes in the pathophysiology of the disease; and 4) project forward as we embark upon a widening use of these new and powerful technologies for gene discovery. (Endocrine Reviews 36: 603-621, 2015).

  6. Discovering Genes Essential to the Hypothalamic Regulation of Human Reproduction Using a Human Disease Model: Adjusting to Life in the “-Omics” Era

    Science.gov (United States)

    Stamou, M. I.; Cox, K. H.

    2015-01-01

    The neuroendocrine regulation of reproduction is an intricate process requiring the exquisite coordination of an assortment of cellular networks, all converging on the GnRH neurons. These neurons have a complex life history, migrating mainly from the olfactory placode into the hypothalamus, where GnRH is secreted and acts as the master regulator of the hypothalamic-pituitary-gonadal axis. Much of what we know about the biology of the GnRH neurons has been aided by discoveries made using the human disease model of isolated GnRH deficiency (IGD), a family of rare Mendelian disorders that share a common failure of secretion and/or action of GnRH causing hypogonadotropic hypogonadism. Over the last 30 years, research groups around the world have been investigating the genetic basis of IGD using different strategies based on complex cases that harbor structural abnormalities or single pleiotropic genes, endogamous pedigrees, candidate gene approaches as well as pathway gene analyses. Although such traditional approaches, based on well-validated tools, have been critical to establish the field, new strategies, such as next-generation sequencing, are now providing speed and robustness, but also revealing a surprising number of variants in known IGD genes in both patients and healthy controls. Thus, before the field moves forward with new genetic tools and continues discovery efforts, we must reassess what we know about IGD genetics and prepare to hold our work to a different standard. The purpose of this review is to: 1) look back at the strategies used to discover the “known” genes implicated in the rare forms of IGD; 2) examine the strengths and weaknesses of the methodologies used to validate genetic variation; 3) substantiate the role of known genes in the pathophysiology of the disease; and 4) project forward as we embark upon a widening use of these new and powerful technologies for gene discovery. PMID:26394276

  7. Reproductive performance in East Greenland polar bears (Ursus maritimus) may be affected by organohalogen contaminants as shown by physiologically-based pharmacokinetic (PBPK) modelling.

    Science.gov (United States)

    Sonne, Christian; Gustavson, Kim; Rigét, Frank F; Dietz, Rune; Birkved, Morten; Letcher, Robert J; Bossi, Rossana; Vorkamp, Katrin; Born, Erik W; Petersen, Gitte

    2009-12-01

    Polar bears (Ursus maritimus) feed mainly on ringed seal (Phoca hispida) and consume large quantities of blubber and consequently have one of the highest tissue concentrations of organohalogen contaminants (OHCs) worldwide. In East Greenland, studies of OHC time trends and organ system health effects, including reproductive, were conducted during 1990-2006. However, it has been difficult to determine the nature of the effects induced by OHC exposures on wild caught polar bears using body burden data and associated changes in reproductive organs and systems. We therefore conducted a risk quotient (RQ) evaluation to more quantitatively evaluate the effect risk on reproduction (embryotoxicity and teratogenicity) based on the critical body residue (CBR) concept and using a physiologically-based pharmacokinetic (PBPK) model. We applied modelling approaches to PCBs, p,p'-DDE, dieldrin, oxychlordane, HCHs, HCB, PBDEs and PFOS in East Greenland polar bears based on known OHC pharmacokinetics and dynamics in laboratory rats (Rattus rattus). The results showed that subcutaneous adipose tissue concentrations of dieldrin (range: 79-1271 ng g(-1) lw) and PCBs (range: 4128-53,923 ng g(-1) lw) reported in bears in the year 1990 were in the range to elicit possible adverse health effects on reproduction in polar bears in East Greenland (all RQs > or = 1). Similar results were found for PCBs (range: 1928-17,376 ng g(-1) lw) and PFOS (range: 104-2840 ng g(-1) ww) in the year 2000 and for dieldrin (range: 43-640 ng g(-1) lw), PCBs (range: 3491-13,243 ng g(-1) lw) and PFOS (range: 1332-6160 ng g(-1) ww) in the year 2006. The concentrations of oxychlordane, DDTs, HCB and HCHs in polar bears resulted in RQspolar bears correlated to OHC exposure are supported by the present study. This study also indicates that PBPK models may be a supportive tool in the evaluation of possible OHC-mediated health effects for Arctic wildlife.

  8. Culture and religious beliefs in relation to reproductive health.

    Science.gov (United States)

    Arousell, Jonna; Carlbom, Aje

    2016-04-01

    An increasing number of contemporary research publications acknowledge the influence of religion and culture on sexual and reproductive behavior and health-care utilization. It is currently hypothesized that religious influences can partly explain disparities in sexual and reproductive health outcomes. In this paper, we will pay particular attention to Muslims in sexual and reproductive health care. This review reveals that knowledge about devout Muslims' own experience of sexual and reproductive health-care matters is limited, thus providing weak evidence for modeling of efficient practical guidelines for sexual and reproductive health care directed at Muslim patients. Successful outcomes in sexual and reproductive health of Muslims require both researchers and practitioners to acknowledge religious heterogeneity and variability, and individuals' possibilities to negotiate Islamic edicts. Failure to do so could lead to inadequate health-care provision and, in the worst case, to suboptimal encounters between migrants with Muslim background and the health-care providers in the receiving country. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. modelling for optimal number of line storage reservoirs in a water

    African Journals Online (AJOL)

    user

    reservoirs and the source of pipe network both increase, while the costs of the demand pipe network decreases. Consequently, a trade-off exits between the storage reservoir and source network cost and the demand network costs. The optimal number of storage reservoirs is that number which gives a system of least total ...

  10. Age-growth models for tilapia Oreochromis aureus (Perciformes, Cichlidae of the Infiernillo reservoir, Mexico and reproductive behaviour

    Directory of Open Access Journals (Sweden)

    Lourdes Jiménez-Badillo

    2006-06-01

    Full Text Available In presence of a decrease in the catch from Infiernillo reservoir, Michoacán-Guerrero, México, age and growth of tilapia Oreochromis aureus (Steindachner 1864 were estimated, as indispensable attributes for fishery management. Evaluations included scales and opercular bones readings and length frequency analysis. The population structure was determined too. Due to the great variation of tilapia individual growth and with the objective to have reliable growth estimations, linearized, non-parametric and non-linear methods were used and their applicability discussed. Comparison of ages determined from these methods revealed that opercular bones readings had advantages over scales. Reproduction and competition for space and food were considered as responsible factors for ring-formation on tilapia hard structures. The non-linear method was considered the best for modelling populations highly variable, which is characteristic of tilapia and tropical fish with multiple spawns. The growth parameters estimated were L∞ = 479 mm, K = 0.46/yr, t o = -0.055 yr. The tilapia population in Infiernillo reservoir is dominated by juveniles less than 1.5 years old. The fishery activity is affecting the tilapia population growth because are caught when they have not yet spawned. Therefore, this fishery is in urgent need of regulation. Increasing the mesh size of the gill nets might contribute to protect the reproductive potential of the stock. Rev. Biol. Trop. 54(2: 577-588. Epub 2006 Jun 01.Ante el continuo decremento en las capturas de tilapia de la presa Infiernillo, Michoacán- Guerrero, México, se estimó la edad y crecimiento de Oreochromis aureus (Steindachner 1864 que son atributos indispensables que deben conocerse para realizar el manejo de la pesquería. La evaluación incluyó la lectura de marcas de crecimiento en escamas y opérculos, y el análisis de frecuencia de tallas. También se estimó la estructura de edad de la población. Debido a la

  11. Quantum distance and the Euler number index of the Bloch band in a one-dimensional spin model.

    Science.gov (United States)

    Ma, Yu-Quan

    2014-10-01

    We study the Riemannian metric and the Euler characteristic number of the Bloch band in a one-dimensional spin model with multisite spins exchange interactions. The Euler number of the Bloch band originates from the Gauss-Bonnet theorem on the topological characterization of the closed Bloch states manifold in the first Brillouin zone. We study this approach analytically in a transverse field XY spin chain with three-site spin coupled interactions. We define a class of cyclic quantum distance on the Bloch band and on the ground state, respectively, as a local characterization for quantum phase transitions. Specifically, we give a general formula for the Euler number by means of the Berry curvature in the case of two-band models, which reveals its essential relation to the first Chern number of the band insulators. Finally, we show that the ferromagnetic-paramagnetic phase transition in zero temperature can be distinguished by the Euler number of the Bloch band.

  12. Reproductive Health Policy in Tunisia

    Science.gov (United States)

    Goicolea, Isabel; Hernandez, Alison

    2016-01-01

    Abstract Although Tunisia is regarded as a pioneer in the Middle East and North Africa in terms of women’s status and rights, including sexual and reproductive health and rights, evidence points to a number of persisting challenges. This article uses the Health Rights of Women Assessment Instrument (HeRWAI) to analyze Tunisia’s reproductive health policy between 1994 and 2014. It explores the extent to which reproductive rights have been incorporated into the country’s reproductive health policy, the gaps in the implementation of this policy, and the influence of this policy on gender empowerment. Our results reveal that progress has been slow in terms of incorporating reproductive rights into the national reproductive health policy. Furthermore, the implementation of this policy has fallen short, as demonstrated by regional inequities in the accessibility and availability of reproductive health services, the low quality of maternal health care services, and discriminatory practices. Finally, the government’s lack of meaningful engagement in advancing gender empowerment stands in the way as the main challenge to gender equality in Tunisia. PMID:28559685

  13. Model for modulated and chaotic waves in zero-Prandtl-number ...

    Indian Academy of Sciences (India)

    KCD) [20] for thermal convection in zero-Prandtl-number fluids in the presence of Coriolis force showed the possibility of self-tuned temporal quasiperiodic waves at the onset of thermal convection. However, the effect of modulation when the.

  14. Turbulence Models: Data from Other Experiments: Shock Wave / Turbulent Boundary Layer Flows at High Mach Numbers

    Data.gov (United States)

    National Aeronautics and Space Administration — Shock Wave / Turbulent Boundary Layer Flows at High Mach Numbers. This web page provides data from experiments that may be useful for the validation of turbulence...

  15. Model Experiments with Low Reynolds Number Effects in a Ventilated Room

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Filholm, Claus; Topp, Claus

    The flow in a ventilated room will not always be a fully developed turbulent flow . Reduced air change rates owing to energy considerations and the application of natural ventilation with openings in the outer wall will give room air movements with low turbulence effects. This paper discusses...... the isothermal low Reynolds number flow from a slot inlet in the end wall of the room. The experiments are made on the scale of 1 to 5. Measurements indicate a low Reynolds number effect in the wall jet flow. The virtual origin of the wall jet moves forward in front of the opening at a small Reynolds number......, an effect that is also known from measurements on free jets. The growth rate of the jet, or the length scale, increases and the velocity decay factor decreases at small Reynolds numbers....

  16. Study efficacy of new model of derivative clonazepam on hypnotic, sedative, blood hematology and evaluation reproductive function in male mice

    Directory of Open Access Journals (Sweden)

    Adnan M. Jassim

    2016-12-01

    Conclusion clonazepam (T1 and 88 compound (T3 with high dose 50 mg/kg have good hypnotic action with complete muscle relaxant. In addition to all, agents have good analgesic effect but T2 showed prominent result. Finally, clonazepam and its related agent 88, 89 compound reveal adverse effect on reproductive function but may be very slightly in 94 compound.

  17. The importance of socio-economic context for social marketing models for improving reproductive health: evidence from 555 years of program experience.

    Science.gov (United States)

    Meekers, Dominique; Rahaim, Stephen

    2005-01-27

    Over the past two decades, social marketing programs have become an important element of the national family planning and HIV prevention strategy in several developing countries. As yet, there has not been any comprehensive empirical assessment to determine which of several social marketing models is most effective for a given socio-economic context. Such an assessment is urgently needed to inform the design of future social marketing programs, and to avoid that programs are designed using an ineffective model. This study addresses this issue using a database of annual statistics about reproductive health oriented social marketing programs in over 70 countries. In total, the database covers 555 years of program experience with social marketing programs that distribute and promote the use of oral contraceptives and condoms. Specifically, our analysis assesses to what extent the model used by different reproductive health social marketing programs has varied across different socio-economic contexts. We then use random effects regression to test in which socio-economic context each of the models is most successful at increasing use of socially marketed oral contraceptives and condoms. The results show that there has been a tendency to design reproductive health social marketing program with a management structure that matches the local context. However, the evidence also shows that this has not always been the case. While socio-economic context clearly influences the effectiveness of some of the social marketing models, program maturity and the size of the target population appear equally important. To maximize the effectiveness of future social marketing programs, it is essential that more effort is devoted to ensuring that such programs are designed using the model or approach that is most suitable for the local context.

  18. The importance of socio-economic context for social marketing models for improving reproductive health: Evidence from 555 years of program experience

    Directory of Open Access Journals (Sweden)

    Rahaim Stephen

    2005-01-01

    Full Text Available Abstract Background Over the past two decades, social marketing programs have become an important element of the national family planning and HIV prevention strategy in several developing countries. As yet, there has not been any comprehensive empirical assessment to determine which of several social marketing models is most effective for a given socio-economic context. Such an assessment is urgently needed to inform the design of future social marketing programs, and to avoid that programs are designed using an ineffective model. Methods This study addresses this issue using a database of annual statistics about reproductive health oriented social marketing programs in over 70 countries. In total, the database covers 555 years of program experience with social marketing programs that distribute and promote the use of oral contraceptives and condoms. Specifically, our analysis assesses to what extent the model used by different reproductive health social marketing programs has varied across different socio-economic contexts. We then use random effects regression to test in which socio-economic context each of the models is most successful at increasing use of socially marketed oral contraceptives and condoms. Results The results show that there has been a tendency to design reproductive health social marketing program with a management structure that matches the local context. However, the evidence also shows that this has not always been the case. While socio-economic context clearly influences the effectiveness of some of the social marketing models, program maturity and the size of the target population appear equally important. Conclusions To maximize the effectiveness of future social marketing programs, it is essential that more effort is devoted to ensuring that such programs are designed using the model or approach that is most suitable for the local context.

  19. The importance of socio-economic context for social marketing models for improving reproductive health: Evidence from 555 years of program experience

    Science.gov (United States)

    Meekers, Dominique; Rahaim, Stephen

    2005-01-01

    Background Over the past two decades, social marketing programs have become an important element of the national family planning and HIV prevention strategy in several developing countries. As yet, there has not been any comprehensive empirical assessment to determine which of several social marketing models is most effective for a given socio-economic context. Such an assessment is urgently needed to inform the design of future social marketing programs, and to avoid that programs are designed using an ineffective model. Methods This study addresses this issue using a database of annual statistics about reproductive health oriented social marketing programs in over 70 countries. In total, the database covers 555 years of program experience with social marketing programs that distribute and promote the use of oral contraceptives and condoms. Specifically, our analysis assesses to what extent the model used by different reproductive health social marketing programs has varied across different socio-economic contexts. We then use random effects regression to test in which socio-economic context each of the models is most successful at increasing use of socially marketed oral contraceptives and condoms. Results The results show that there has been a tendency to design reproductive health social marketing program with a management structure that matches the local context. However, the evidence also shows that this has not always been the case. While socio-economic context clearly influences the effectiveness of some of the social marketing models, program maturity and the size of the target population appear equally important. Conclusions To maximize the effectiveness of future social marketing programs, it is essential that more effort is devoted to ensuring that such programs are designed using the model or approach that is most suitable for the local context. PMID:15676068

  20. Development of QSAR models using artificial neural network analysis for risk assessment of repeated-dose, reproductive, and developmental toxicities of cosmetic ingredients.

    Science.gov (United States)

    Hisaki, Tomoka; Aiba Née Kaneko, Maki; Yamaguchi, Masahiko; Sasa, Hitoshi; Kouzuki, Hirokazu

    2015-04-01

    Use of laboratory animals for systemic toxicity testing is subject to strong ethical and regulatory constraints, but few alternatives are yet available. One possible approach to predict systemic toxicity of chemicals in the absence of experimental data is quantitative structure-activity relationship (QSAR) analysis. Here, we present QSAR models for prediction of maximum "no observed effect level" (NOEL) for repeated-dose, developmental and reproductive toxicities. NOEL values of 421 chemicals for repeated-dose toxicity, 315 for reproductive toxicity, and 156 for developmental toxicity were collected from Japan Existing Chemical Data Base (JECDB). Descriptors to predict toxicity were selected based on molecular orbital (MO) calculations, and QSAR models employing multiple independent descriptors as the input layer of an artificial neural network (ANN) were constructed to predict NOEL values. Robustness of the models was indicated by the root-mean-square (RMS) errors after 10-fold cross-validation (0.529 for repeated-dose, 0.508 for reproductive, and 0.558 for developmental toxicity). Evaluation of the models in terms of the percentages of predicted NOELs falling within factors of 2, 5 and 10 of the in-vivo-determined NOELs suggested that the model is applicable to both general chemicals and the subset of chemicals listed in International Nomenclature of Cosmetic Ingredients (INCI). Our results indicate that ANN models using in silico parameters have useful predictive performance, and should contribute to integrated risk assessment of systemic toxicity using a weight-of-evidence approach. Availability of predicted NOELs will allow calculation of the margin of safety, as recommended by the Scientific Committee on Consumer Safety (SCCS).

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

    Science.gov (United States)

    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. Published by Elsevier B.V.

  2. 511, America's traveler information number. Deployment assistance report #1, Business models and cost considerations

    Science.gov (United States)

    2002-01-01

    Business models and cost recovery are the critical factors for determining the sustainability of the traveler information service, and 511. In March 2001 the Policy Committee directed the 511 Working Group to investigate plausible business models and...

  3. Minimum required number of specimen records to develop accurate species distribution models

    NARCIS (Netherlands)

    Proosdij, van A.S.J.; Sosef, M.S.M.; Wieringa, J.J.; Raes, N.

    2016-01-01

    Species distribution models (SDMs) are widely used to predict the occurrence of species. Because SDMs generally use presence-only data, validation of the predicted distribution and assessing model accuracy is challenging. Model performance depends on both sample size and species’ prevalence, being

  4. Minimum required number of specimen records to develop accurate species distribution models

    NARCIS (Netherlands)

    Proosdij, van A.S.J.; Sosef, M.S.M.; Wieringa, Jan; Raes, N.

    2015-01-01

    Species Distribution Models (SDMs) are widely used to predict the occurrence of species. Because SDMs generally use presence-only data, validation of the predicted distribution and assessing model accuracy is challenging. Model performance depends on both sample size and species’ prevalence, being

  5. Assisted Reproductive Technology (ART)

    Science.gov (United States)

    ... Share Facebook Twitter Pinterest Email Print Assisted Reproductive Technology (ART) ART refers to treatments and procedures that ... American Society for Reproductive Medicine. (2015). Assisted reproductive technologies: A guide for patients . Retrieved May 31, 2016, ...

  6. Reproduction, physiology and biochemistry

    Science.gov (United States)

    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...

  7. Estimating multilevel logistic regression models when the number of clusters is low: a comparison of different statistical software procedures.

    Science.gov (United States)

    Austin, Peter C

    2010-04-22

    Multilevel logistic regression models are increasingly being used to analyze clustered data in medical, public health, epidemiological, and educational research. Procedures for estimating the parameters of such models are available in many statistical software packages. There is currently little evidence on the minimum number of clusters necessary to reliably fit multilevel regression models. We conducted a Monte Carlo study to compare the performance of different statistical software procedures for estimating multilevel logistic regression models when the number of clusters was low. We examined procedures available in BUGS, HLM, R, SAS, and Stata. We found that there were qualitative differences in the performance of different software procedures for estimating multilevel logistic models when the number of clusters was low. Among the likelihood-based procedures, estimation methods based on adaptive Gauss-Hermite approximations to the likelihood (glmer in R and xtlogit in Stata) or adaptive Gaussian quadrature (Proc NLMIXED in SAS) tended to have superior performance for estimating variance components when the number of clusters was small, compared to software procedures based on penalized quasi-likelihood. However, only Bayesian estimation with BUGS allowed for accurate estimation of variance components when there were fewer than 10 clusters. For all statistical software procedures, estimation of variance components tended to be poor when there were only five subjects per cluster, regardless of the number of clusters.

  8. Generating a lexicon without a language model: Do words for number count?

    Science.gov (United States)

    Spaepen, Elizabet; Coppola, Marie; Flaherty, Molly; Spelke, Elizabeth; Goldin-Meadow, Susan

    2013-11-01

    Homesigns are communication systems created by deaf individuals without access to conventional linguistic input. To investigate how homesign gestures for number function in short-term memory compared to homesign gestures for objects, actions, or attributes, we conducted memory span tasks with adult homesigners in Nicaragua, and with comparison groups of unschooled hearing Spanish speakers and deaf Nicaraguan Sign Language signers. There was no difference between groups in recall of gestures or words for objects, actions or attributes; homesign gestures therefore can function as word units in short-term memory. However, homesigners showed poorer recall of numbers than the other groups. Unlike the other groups, increasing the numerical value of the to-be-remembered quantities negatively affected recall in homesigners, but not controls. When developed without linguistic input, gestures for number do not seem to function as summaries of the cardinal values of the sets ( four ), but rather as indexes of items within a set ( one-one-one-one ).

  9. Comparative Study of Fatigue Damage Models Using Different Number of Classes Combined with the Rainflow Method

    Directory of Open Access Journals (Sweden)

    S. Zengah

    2013-06-01

    Full Text Available Fatigue damage increases with applied load cycles in a cumulative manner. Fatigue damage models play a key role in life prediction of components and structures subjected to random loading. The aim of this paper is the examination of the performance of the “Damaged Stress Model”, proposed and validated, against other fatigue models under random loading before and after reconstruction of the load histories. To achieve this objective, some linear and nonlinear models proposed for fatigue life estimation and a batch of specimens made of 6082T6 aluminum alloy is subjected to random loading. The damage was cumulated by Miner’s rule, Damaged Stress Model (DSM, Henry model and Unified Theory (UT and random cycles were counted with a rain-flow algorithm. Experimental data on high-cycle fatigue by complex loading histories with different mean and amplitude stress values are analyzed for life calculation and model predictions are compared.

  10. Female reproductive disorders

    DEFF Research Database (Denmark)

    Crain, D Andrew; Janssen, Sarah J; Edwards, Thea M

    2008-01-01

    To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive disrupti......To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive...

  11. Assisted Reproductive Technology: MedlinePlus Health Topic

    Science.gov (United States)

    ... can be prevented or minimized by limiting the number of embryos that are put into the woman's body. Learn More Assisted Reproductive Technologies (American Society for Reproductive Medicine) - PDF Also ...

  12. Costs of integrating demand-based reproductive health commodity model into the Government and NGO service delivery systems in Bangladesh: a supply side perspective.

    Science.gov (United States)

    Islam, Ziaul; Sarker, Abdur Razzaque; Anwar, Shahela; Kabir, Humayun; Gazi, Rukhsana

    2015-01-01

    To estimate additional total cost and average cost of integrating the demand-based reproductive health commodity model into the existing Government and NGO facilities in Bangladesh. Activity based cost analysis was conducted during 2006-2008 in two low performing rural sub-districts (Nabigong and Raipur sub-district) and one urban slum area in Dhaka city, Bangladesh. Activity-based cost data were collected using ingredient approach, which comprised of listing all types of inputs by activity, quantities and prices for each input. Total cost was presented according to capital and recurrent items. The supply side perspective was considered for entire analysis. The total cost of integrating demand-based reproductive health commodity (DBRHC) model into the Government and NGO service delivery system was estimated to BDT 18,667,634 (US$274,524). The proportion of capital cost was 59 % and the recurrent cost was 41 % of the total cost. The average cost per beneficiaries was BDT 230 (US$3.38) only for introducing this model into the existing health system. The built-in interventions of DBRHC model were doable at low-cost at the selected Government and NGO settings at the grass-root level. The model has potential of further cost containment during scaling up-if the intervention costs are adjusted with the existing functionaries of the Government and NGOs.

  13. DTIC Review: Human, Social, Cultural and Behavior Modeling. Volume 9, Number 1 (CD-ROM)

    National Research Council Canada - National Science Library

    2008-01-01

    ...: Human, Social, Cultural and Behavior (HSCB) models are designed to help understand the structure, interconnections, dependencies, behavior, and trends associated with any collection of individuals...

  14. Multilook SAR Image Segmentation with an Unknown Number of Clusters Using a Gamma Mixture Model and Hierarchical Clustering.

    Science.gov (United States)

    Zhao, Quanhua; Li, Xiaoli; Li, Yu

    2017-05-12

    This paper presents a novel multilook SAR image segmentation algorithm with an unknown number of clusters. Firstly, the marginal probability distribution for a given SAR image is defined by a Gamma mixture model (GaMM), in which the number of components corresponds to the number of homogeneous regions needed to segment and the spatial relationship among neighboring pixels is characterized by a Markov Random Field (MRF) defined by the weighting coefficients of components in GaMM. During the algorithm iteration procedure, the number of clusters is gradually reduced by merging two components until they are equal to one. For each fixed number of clusters, the parameters of GaMM are estimated and the optimal segmentation result corresponding to the number is obtained by maximizing the marginal probability. Finally, the number of clusters with minimum global energy defined as the negative logarithm of marginal probability is indicated as the expected number of clusters with the homogeneous regions needed to be segmented, and the corresponding segmentation result is considered as the final optimal one. The experimental results from the proposed and comparing algorithms for simulated and real multilook SAR images show that the proposed algorithm can find the real number of clusters and obtain more accurate segmentation results simultaneously.

  15. Women Reproductive Rights in India: Prospective Future.

    OpenAIRE

    Kosgi, S; Hegde, VN; Rao, S; Bhat, US; Pai, N

    2011-01-01

    Reproductive rights were established as a subset of the human rights. Parents have a basic human right to determine freely and responsibly the number and the spacing of their children. Issues regarding the reproductive rights are vigorously contested, regardless of the population’s socioeconomic level, religion or culture. Following review article discusses reproductive rights with respect to Indian context focusing on socio economic and cultural aspects. Also discusses sensitization of gover...

  16. Long-acting neuroleptic use for reproductive management of non-domestic ungulates using the domestic goat (Capra hircus) as a model.

    Science.gov (United States)

    Weiss, Rachael B; Schook, Mandi W; Wolfe, Barbara A

    2014-01-01

    Fluphenazine decanoate is a long-acting phenothiazine neuroleptic that attenuates the stress response and may be useful during intensive handling for reproductive procedures in non-domestic ungulates. However, phenothiazines are also associated with elevated serum prolactin, which can suppress fertility in some species. For this study, 10 female domestic goats were used as a model for non-domestic caprids to test effects of fluphenazine decanoate on serum cortisol and reproductive cyclicity following estrus synchronization. Two identical trials were conducted during the breeding season, employing a random crossover design. First, females underwent estrus synchronization using a 14-day treatment with progesterone (330 mg; CIDR). After 7 days of CIDR exposure, the treatment group (n = 5) received fluphenazine decanoate (1.0 mg/kg IM) and controls (n = 5) received an equivalent volume of 0.9% saline IM. At CIDR withdrawal (Day 14), animals received 125 mg cloprostenol sodium to lyse any luteal tissue and synchronize estrus. Blood was collected every 2 hr from 36 hr after CIDR withdrawal until 24 hr after standing estrus, or up to 5 days to monitor stress and reproductive hormones. Serum cortisol, prolactin, luteinizing hormone (LH) and progesterone concentrations were determined by enzyme immunoassay. While treatment with fluphenazine was associated with lower cortisol concentrations compared to controls (P = 0.001), 4 of the 10 treated animals experienced elevated serum prolactin, suppression of the LH surge and inhibition of ovulation. These findings suggest that long-acting neuroleptic drugs reduce the adrenal stress response, but may interfere with reproductive responses and negatively influence breeding success. © 2014 Wiley Periodicals, Inc.

  17. Modelling Problem-Solving Situations into Number Theory Tasks: The Route towards Generalisation

    Science.gov (United States)

    Papadopoulos, Ioannis; Iatridou, Maria

    2010-01-01

    This paper examines the way two 10th graders cope with a non-standard generalisation problem that involves elementary concepts of number theory (more specifically linear Diophantine equations) in the geometrical context of a rectangle's area. Emphasis is given on how the students' past experience of problem solving (expressed through interplay…

  18. Comparison of the 1981 INEL dispersion data with results from a number of different models

    Energy Technology Data Exchange (ETDEWEB)

    Lewellen, W S; Sykes, R I; Parker, S F

    1985-05-01

    The results from simulations by 12 different dispersion models are compared with observations from an extensive field experiment conducted by the Nuclear Regulatory Commission at the Idaho National Engineering Laboratory in July, 1981. Comparisons were made on the bases of hourly SF/sub 6/ samples taken at the surface, out to approximately 10 km from the 46 m release tower, both during and following 7 different 8-hour releases. Comparisons are also made for total integrated doses collected out to approximately 40 km. Three classes of models are used. Within the limited range appropriate for Class A models this data comparison shows that neither the puff models or the transport and diffusion models agree with the data any better than the simple Gaussian plume models. The puff and transport and diffusion models do show a slight edge in performance in comparison with the total dose over the extended range approximate for class B models. The best model results for the hourly samples show approximately 40% calculated within a factor of two when a 15/sup 0/ uncertainty in plume position is permitted and it is assumed that higher data samples may occur at stations between the actual sample sites. This is increased to 60% for the 12 hour integrated dose and 70% for the total integrated dose when the same performance measure is used. None of the models reproduce the observed patchy dose patterns. This patchiness is consistent with the discussion of the inherent uncertainty associated with time averaged plume observations contained in our companion reports on the scientific critique of available models.

  19. Modeling the Transverse Shell-side Mass Transfer in Hollow Fiber Membrane Contactors at Low Reynolds Numbers

    Science.gov (United States)

    Kirsch, V. A.; Volkov, V. V.; Bildukevich, A. V.

    A method for calculating the external mass transfer in a contactor with a transverse confined flow of a viscous incompressible liquid (gas) past hollow fibers at low Reynolds numbers is proposed. The method is based on the concept of regular arrays of parallel fibers with a well-defined flowfield. As a simplest model system, a row of parallel fibers is considered, for which dependences of a drag force and an efficiency of a solute retention on the inter-fiber distance, membrane mass transfer coefficient, Peclet and Reynolds numbers are computed. The influence of the fluid inertia on the mass transport is studied. It is shown that a linear Stokes equations can be used for as higher Re numbers, as denser is the fiber array. In this case the flow field is independent on the Re number, and analytical solutions for the flowfield and fiber sorption efficiency (fiber Sherwood number) can be used.

  20. Pseudorandom numbers: evolutionary models in image processing, biology, and nonlinear dynamic systems

    Science.gov (United States)

    Yaroslavsky, Leonid P.

    1996-11-01

    We show that one can treat pseudo-random generators, evolutionary models of texture images, iterative local adaptive filters for image restoration and enhancement and growth models in biology and material sciences in a unified way as special cases of dynamic systems with a nonlinear feedback.

  1. The effects of food availability on growth and reproduction of Daphnia magna exposed to silver nanoparticles

    DEFF Research Database (Denmark)

    Mackevica, Aiga; Skjolding, Lars Michael; Gergs, A.

    offspring, and number of neonates produced. The data obtained from the chronic tests are intended for modeling using the Dynamic Energy Budget (DEB) theory, which will hopefully provide information on growth and reproduction strategy of the test animals. The concentrations of silver in the test medium over......The number of available studies on the acute effects of silver nanoparticles (AgNP) on aquatic organisms has increased dramatically in recent years, but there is still very limited information available on chronic effects. In this study, a series of Daphnia magna 21-days reproduction test (OECD 211...... exposed to 10 μgAg/L showed enhanced reproduction compared to controls, however the toxic effects on growth and reproduction appeared in concentrations above 20 μgAg/L. A reference test was performed with silver nitrate in concentrations ranging from 0.25 to 1.5 μgAg/L. Mortality was increasing...

  2. MODEL-OBSERVATION COMPARISONS OF ELECTRON NUMBER DENSITIES IN THE COMA OF 67P/CHURYUMOV–GERASIMENKO DURING 2015 JANUARY

    Energy Technology Data Exchange (ETDEWEB)

    Vigren, E.; Edberg, N. J. T.; Eriksson, A. I.; Johansson, F.; Odelstad, E. [Swedish Institute of Space Physics, Uppsala (Sweden); Altwegg, K.; Tzou, C.-Y. [Physikalisches Institut, University of Bern, Bern (Switzerland); Galand, M. [Department of Physics, Imperial College London, London (United Kingdom); Henri, P.; Valliéres, X., E-mail: erik.vigren@irfu.se [Laboratoire de Physique et Chimie de l’Environnement et de l’Espace, Orleans (France)

    2016-09-01

    During 2015 January 9–11, at a heliocentric distance of ∼2.58–2.57 au, the ESA Rosetta spacecraft resided at a cometocentric distance of ∼28 km from the nucleus of comet 67P/Churyumov–Gerasimenko, sweeping the terminator at northern latitudes of 43°N–58°N. Measurements by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis/Comet Pressure Sensor (ROSINA/COPS) provided neutral number densities. We have computed modeled electron number densities using the neutral number densities as input into a Field Free Chemistry Free model, assuming H{sub 2}O dominance and ion-electron pair formation by photoionization only. A good agreement (typically within 25%) is found between the modeled electron number densities and those observed from measurements by the Mutual Impedance Probe (RPC/MIP) and the Langmuir Probe (RPC/LAP), both being subsystems of the Rosetta Plasma Consortium. This indicates that ions along the nucleus-spacecraft line were strongly coupled to the neutrals, moving radially outward with about the same speed. Such a statement, we propose, can be further tested by observations of H{sub 3}O{sup +}/H{sub 2}O{sup +} number density ratios and associated comparisons with model results.

  3. Reproductive risk factors assessment for anaemia among pregnant women in India using a multinomial logistic regression model.

    Science.gov (United States)

    Perumal, Vanamail

    2014-07-01

    To assess reproductive risk factors for anaemia among pregnant women in urban and rural areas of India. The International Institute of Population Sciences, India, carried out third National Family Health Survey in 2005-2006 to estimate a key indicator from a sample of ever-married women in the reproductive age group 15-49 years. Data on various dimensions were collected using a structured questionnaire, and anaemia was measured using a portable HemoCue instrument. Anaemia prevalence among pregnant women was compared between rural and urban areas using chi-square test and odds ratio. Multinomial logistic regression analysis was used to determine risk factors. Anaemia prevalence was assessed among 3355 pregnant women from rural areas and 1962 pregnant women from urban areas. Moderate-to-severe anaemia in rural areas (32.4%) is significantly more common than in urban areas (27.3%) with an excess risk of 30%. Gestational age specific prevalence of anaemia significantly increases in rural areas after 6 months. Pregnancy duration is a significant risk factor in both urban and rural areas. In rural areas, increasing age at marriage and mass media exposure are significant protective factors of anaemia. However, more births in the last five years, alcohol consumption and smoking habits are significant risk factors. In rural areas, various reproductive factors and lifestyle characteristics constitute significant risk factors for moderate-to-severe anaemia. Therefore, intensive health education on reproductive practices and the impact of lifestyle characteristics are warranted to reduce anaemia prevalence. © 2014 John Wiley & Sons Ltd.

  4. Baryon number and lepton universality violation in leptoquark and diquark models

    Directory of Open Access Journals (Sweden)

    Nima Assad

    2018-02-01

    Full Text Available We perform a systematic study of models involving leptoquarks and diquarks with masses well below the grand unification scale and demonstrate that a large class of them is excluded due to rapid proton decay. After singling out the few phenomenologically viable color triplet and sextet scenarios, we show that there exist only two leptoquark models which do not suffer from tree-level proton decay and which have the potential for explaining the recently discovered anomalies in B meson decays. Both of those models, however, contain dimension five operators contributing to proton decay and require a new symmetry forbidding them to emerge at a higher scale. This has a particularly nice realization for the model with the vector leptoquark (3,12/3, which points to a specific extension of the Standard Model, namely the Pati–Salam unification model, where this leptoquark naturally arises as the new gauge boson. We explore this possibility in light of recent B physics measurements. Finally, we analyze also a vector diquark model, discussing its LHC phenomenology and showing that it has nontrivial predictions for neutron–antineutron oscillation experiments.

  5. On Spatial Resolution in Habitat Models: Can Small-scale Forest Structure Explain Capercaillie Numbers?

    Directory of Open Access Journals (Sweden)

    Ilse Storch

    2002-06-01

    Full Text Available This paper explores the effects of spatial resolution on the performance and applicability of habitat models in wildlife management and conservation. A Habitat Suitability Index (HSI model for the Capercaillie (Tetrao urogallus in the Bavarian Alps, Germany, is presented. The model was exclusively built on non-spatial, small-scale variables of forest structure and without any consideration of landscape patterns. The main goal was to assess whether a HSI model developed from small-scale habitat preferences can explain differences in population abundance at larger scales. To validate the model, habitat variables and indirect sign of Capercaillie use (such as feathers or feces were mapped in six study areas based on a total of 2901 20 m radius (for habitat variables and 5 m radius sample plots (for Capercaillie sign. First, the model's representation of Capercaillie habitat preferences was assessed. Habitat selection, as expressed by Ivlev's electivity index, was closely related to HSI scores, increased from poor to excellent habitat suitability, and was consistent across all study areas. Then, habitat use was related to HSI scores at different spatial scales. Capercaillie use was best predicted from HSI scores at the small scale. Lowering the spatial resolution of the model stepwise to 36-ha, 100-ha, 400-ha, and 2000-ha areas and relating Capercaillie use to aggregated HSI scores resulted in a deterioration of fit at larger scales. Most importantly, there were pronounced differences in Capercaillie abundance at the scale of study areas, which could not be explained by the HSI model. The results illustrate that even if a habitat model correctly reflects a species' smaller scale habitat preferences, its potential to predict population abundance at larger scales may remain limited.

  6. Model for modulated and chaotic waves in zero-Prandtl-number ...

    Indian Academy of Sciences (India)

    c + 2q2)/8, f7 = αβη(3π2 − q2)/2, f8 = αη(4π2β − q2)/4, f9 = (3 + α2). 2.3 Results and discussion. The above dynamical system (eqs (7)–(19)) is now integrated using standard fourth- order Runge–Kutta scheme. The external parameters are Rayleigh number R,. Pramana – J. Phys., Vol. 71, No. 3, September 2008. 549 ...

  7. Comparative study of measured and modelled number concentrations of nanoparticles in an urban street canyon

    DEFF Research Database (Denmark)

    Kumar, Prashant; Garmory, Andrew; Ketzel, Matthias

    2009-01-01

    Pollution Model (OSPM) and Computational Fluid Dynamics (CFD) code FLUENT. All models disregarded any particle dynamics. CFD simulations have been carried out in a simplified geometry of the selected street canyon. Four different sizes of emission sources have been used in the CFD simulations to assess...... simulations showed that selection of the source size was critical to determine PNC distributions. A source size scaling the vehicle dimensions was found to better represent the measured PNC profiles in the lowest part of the canyon. The OSPM and Box model produced similar shapes of PNC profile across...... differences were largest between idealised (CFD and Box) and operational (OSPM) models at upper sampling heights; these were attributed to weaker exchange of air between street and roof-above in the upper part of the canyon in the CFD calculations. Possible reasons for these discrepancies are given....

  8. Total cross sections of hadron interactions at high energies in low constituents number model

    International Nuclear Information System (INIS)

    Abramovskij, V.A.; Radchenko, N.V.

    2009-01-01

    We consider QCD hadrons interaction model in which gluons density is low in initial state wave function in rapidity space and real hadrons are produced from color strings decay. In this model behavior of total cross sections of pp, pp bar, π ± p, K ± p, γp, and γγ interactions is well described. The value of proton-proton total cross section at LHC energy is predicted

  9. Modeling and designing of variable-period and variable-pole-number undulator

    Directory of Open Access Journals (Sweden)

    I. Davidyuk

    2016-02-01

    Full Text Available The concept of permanent-magnet variable-period undulator (VPU was proposed several years ago and has found few implementations so far. The VPUs have some advantages as compared with conventional undulators, e.g., a wider range of radiation wavelength tuning and the option to increase the number of poles for shorter periods. Both these advantages will be realized in the VPU under development now at Budker INP. In this paper, we present the results of 2D and 3D magnetic field simulations and discuss some design features of this VPU.

  10. Occupancy Models, Bell-Type Polynomials and Numbers and Applications to Probability.

    Science.gov (United States)

    1983-06-01

    expressed in terms of such ratios. These recurrences bypass the computational difficulties which come from the fact that the numbers themselves (but not the...biisic properties and rec’u-ruees for r(Tr;nj,r) hrld fac) itat( tlair computation . Remark 2.1 . In tesqlin order t.o avoid unnv e!1.bry cui-l i...Sobel, . , Uppuluri, Y.R.R. and Frankowski, K. (71977). Dirichlet distributions- type 1. In S.lected tables in Mathenatical Statistics, Vol.4

  11. Improving smallholder cattle reproductive efficiency in Cambodia to address expanding regional beef demand.

    Science.gov (United States)

    Olmo, L; Ashley, K; Young, J R; Suon, S; Thomson, P C; Windsor, P A; Bush, R D

    2017-01-01

    This study aimed to identify factors associated with cattle reproductive output in rural smallholder farms in Cambodia in order to determine the main causes of reproductive failure and design efficient interventions for improvement. The majority of the nation's beef is produced on smallholder farms where productivity is constrained by poor animal reproductivity reflected in the recent livestock population decline of approximately 13 % from 2009 to 2013. Farmers (n = 240) from 16 villages from five provinces were surveyed in mid-2015 to determine their baseline knowledge, attitude and practices (KAP) associated with cattle reproduction. In addition, 16 case studies from three of these provinces were conducted to provide a more detailed assessment of current cattle reproductive husbandry practices. In order to assess the reproductive impact of previously implemented interventions, an endpoint KAP survey and longitudinal health and husbandry study from three Cambodian provinces conducted between 2008 and 2013 were also analysed. Three multivariable prediction models (two KAP and one longitudinal) identified the following significant factors associated with the reproductive outcomes 'number of calves born' or probability that cows 'gave birth': target feeding (P = 0.074), growing vegetables (P = 0.005), attitudes towards cattle vaccination (P = 0.010), improving bull selection (P = 0.032), local breed use (P = 0.005), number of joining attempts (P meat demand in South-East Asia and China.

  12. An efficient method for computing genus expansions and counting numbers in the Hermitian matrix model

    International Nuclear Information System (INIS)

    Alvarez, Gabriel; Martinez Alonso, Luis; Medina, Elena

    2011-01-01

    We present a method to compute the genus expansion of the free energy of Hermitian matrix models from the large N expansion of the recurrence coefficients of the associated family of orthogonal polynomials. The method is based on the Bleher-Its deformation of the model, on its associated integral representation of the free energy, and on a method for solving the string equation which uses the resolvent of the Lax operator of the underlying Toda hierarchy. As a byproduct we obtain an efficient algorithm to compute generating functions for the enumeration of labeled k-maps which does not require the explicit expressions of the coefficients of the topological expansion. Finally we discuss the regularization of singular one-cut models within this approach.

  13. Artificial Neural Network to Modeling Zero-inflated Count Data: Application to Predicting Number of Return to Blood Donation.

    Science.gov (United States)

    Haghani, Shima; Sedehi, Morteza; Kheiri, Soleiman

    2017-09-02

    Traditional statistical models often are based on certain presuppositions and limitations that may not presence in actual data and lead to turbulence in estimation or prediction. In these situations, artificial neural networks (ANNs) could be suitable alternative rather than classical statistical methods.  A prospective cohort study. The study was conducted in Shahrekord Blood Transfusion Center, Shahrekord, central Iran, on blood donors from 2008-2009. The accuracy of the proposed model to prediction of number of return to blood donations was compared with classical statistical models. A number of 864 donors who had a first-time successful donation were followed for five years. Number of return for blood donation was considered as response variable. Poisson regression (PR), negative binomial regression (NBR), zero-inflated Poisson regression (ZIPR) and zero-inflated negative binomial regression (ZINBR) as well as ANN model were fitted to data. MSE criterion was used to compare models. To fitting the models, STATISTICA 10 and, R 3.2.2 was used RESULTS: The MSE of PR, NBR, ZIPR, ZINBR and ANN models was obtained 2.71, 1.01, 1.54, 0.094 and 0.056 for the training and 4.05, 9.89, 3.99, 2.53 and 0.27 for the test data, respectively. The ANN model had the least MSE in both training, and test data set and has a better performance than classic models. ANN could be a suitable alternative for modeling such data because of fewer restrictions.

  14. Student standpoints relevant for future reproductive behavior

    Directory of Open Access Journals (Sweden)

    Kuburović Ankica

    2003-01-01

    Full Text Available This paper deals with the various standpoints of students on their motivation for parenthood, planning and deciding on birth giving, influence between marriage and parenthood, parent role complexity and responsibility, on the knowledge of effect and consequences of the problem of insufficient birth giving, with an aim of getting to know the main characteristics of their possible reproductive behavior. The analyzed standpoints are part of a more comprehensive and inclusive research, carried out on a sample of 1494 surveyed persons (1000 secondary-school pupils and 494 students in four biggest regional centers - Belgrade, Novi Sad, Kragujevac and Niš. The orientation only to student’s standpoints had an aim to more completely analyze the already abundant empirical material, which is acceptable due to the fact that students are closer to beginning of birth giving according to their age-situation characteristic. The willingness and desire of the students to become parents is significant, but this is only one of their varied life aspirations (importance of partnership, professional engagement…. The intention is to bring into accordance the realization of the most important roles, which actually indicates to a fairly uniform importance in satisfying the basic individual needs. Apart from that, the need for parenthood is dominantly emotional and altruistic, which can be satisfied by having only one child. Possible reproductive norms - which are directed to having two children, whereby they are higher than the current fertility rates, but also somewhat lower normatively determined expectations in relation to the desired number of children, as well as a significant orientation towards marriage and parenthood and the existence of the knowledge on the problem of the impossibility of simple reproduction and conscience of social need for population reproduction - represent a gap for realization of measures for motivating birth giving and parenthood

  15. Numberical Calculations of Atmospheric Conditions over Tibetan Plateau by Using WRF Model

    International Nuclear Information System (INIS)

    Qian, Xuan; Yao, Yongqiang; Wang, Hongshuai; Liu, Liyong; Li, Junrong; Yin, Jia

    2015-01-01

    The wind field, precipitable water vapor are analyzed by using the mesoscale numerical model WRF over Tibetan Plateau, and the aerosol is analyzed by using WRF- CHEM model. The spatial and vertical distributions of the relevant atmospheric factors are summarized, providing truth evidence for selecting and further evaluating an astronomical site. It has been showed that this method could provide good evaluation of atmospheric conditions. This study serves as a further demonstration towards astro-climate regionalization, and provides with essential database for astronomical site survey over Tibetan Plateau. (paper)

  16. Increased numbers of orexin/hypocretin neurons in a genetic rat depression model

    DEFF Research Database (Denmark)

    Mikrouli, Elli; Wörtwein, Gitta; Soylu, Rana

    2011-01-01

    The Flinders Sensitive Line (FSL) rat is a genetic animal model of depression that displays characteristics similar to those of depressed patients including lower body weight, decreased appetite and reduced REM sleep latency. Hypothalamic neuropeptides such as orexin/hypocretin, melanin-concentra......The Flinders Sensitive Line (FSL) rat is a genetic animal model of depression that displays characteristics similar to those of depressed patients including lower body weight, decreased appetite and reduced REM sleep latency. Hypothalamic neuropeptides such as orexin/hypocretin, melanin...

  17. Reproductive performance of artificially inseminated dairy cows ...

    African Journals Online (AJOL)

    The objectives of the study were to generate a reliable field data set and analyze it to determine reproductive parameters/indices. A total of 280 and 400 households keeping 158 and 709 cows and heifers in Rwanda and Tanzania respectively were studied. Reproductive events: dates of heat, AI or NS, service number, sire ...

  18. Growth and reproductive attributes of radionuclide phytoremediators ...

    African Journals Online (AJOL)

    The study reveals that growth attributes including relative growth rate, net assimilation rate, leaf are index and specific leaf area, dry matter allocated to stem and leaves and number of reproductive organs decreased with the increase of radionuclide content of the plant, while the dry matter allocated to root and reproductive ...

  19. A Validated All-Pressure Fluid Drop Model and Lewis Number Effects for a Binary Mixture

    Science.gov (United States)

    Harstad, K.; Bellan, J.

    1999-01-01

    The differences between subcritical liquid drop and supercritical fluid drop behavior are discussed. Under subcritical, evaporative high emission rate conditions, a film layer is present in the inner part of the drop surface which contributes to the unique determination of the boundary conditions; it is this film layer which contributes to the solution's convective-diffusive character. In contrast, under supercritical condition as the boundary conditions contain a degree of arbitrariness due to the absence of a surface, and the solution has then a purely diffusive character. Results from simulations of a free fluid drop under no-gravity conditions are compared to microgravity experimental data from suspended, large drop experiments at high, low and intermediary temperatures and in a range of pressures encompassing the sub-and supercritical regime. Despite the difference between the conditions of the simulations and experiments (suspension vs. free floating), the time rate of variation of the drop diameter square is remarkably well predicted in the linear curve regime. The drop diameter is determined in the simulations from the location of the maximum density gradient, and agrees well with the data. It is also shown that the classical calculation of the Lewis number gives qualitatively erroneous results at supercritical conditions, but that an effective Lewis number previously defined gives qualitatively correct estimates of the length scales for heat and mass transfer at all pressures.

  20. Sensitivity of a Riparian Large Woody Debris Recruitment Model to the Number of Contributing Banks and Tree Fall Pattern

    Science.gov (United States)

    Don C. Bragg; Jeffrey L. Kershner

    2004-01-01

    Riparian large woody debris (LWD) recruitment simulations have traditionally applied a random angle of tree fall from two well-forested stream banks. We used a riparian LWD recruitment model (CWD, version 1.4) to test the validity these assumptions. Both the number of contributing forest banks and predominant tree fall direction significantly influenced simulated...

  1. Magnetic Helicity Estimations in Models and Observations of the Solar Magnetic Field. III. Twist Number Method

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Y. [School of Astronomy and Space Science and Key Laboratory of Modern Astronomy and Astrophysics in Ministry of Education, Nanjing University, Nanjing 210023 (China); Pariat, E.; Moraitis, K. [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Université, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, F-92190 Meudon (France); Valori, G. [University College London, Mullard Space Science Laboratory, Holmbury St. Mary, Dorking, Surrey, RH5 6NT (United Kingdom); Anfinogentov, S. [Institute of Solar-Terrestrial Physics SB RAS 664033, Irkutsk, P.O. box 291, Lermontov Street, 126a (Russian Federation); Chen, F. [Max-Plank-Institut für Sonnensystemforschung, D-37077 Göttingen (Germany); Georgoulis, M. K. [Research Center for Astronomy and Applied Mathematics of the Academy of Athens, 4 Soranou Efesiou Street, 11527 Athens (Greece); Liu, Y. [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States); Thalmann, J. K. [Institute of Physics, Univeristy of Graz, Universitätsplatz 5/II, A-8010 Graz (Austria); Yang, S., E-mail: guoyang@nju.edu.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2017-05-01

    We study the writhe, twist, and magnetic helicity of different magnetic flux ropes, based on models of the solar coronal magnetic field structure. These include an analytical force-free Titov–Démoulin equilibrium solution, non-force-free magnetohydrodynamic simulations, and nonlinear force-free magnetic field models. The geometrical boundary of the magnetic flux rope is determined by the quasi-separatrix layer and the bottom surface, and the axis curve of the flux rope is determined by its overall orientation. The twist is computed by the Berger–Prior formula, which is suitable for arbitrary geometry and both force-free and non-force-free models. The magnetic helicity is estimated by the twist multiplied by the square of the axial magnetic flux. We compare the obtained values with those derived by a finite volume helicity estimation method. We find that the magnetic helicity obtained with the twist method agrees with the helicity carried by the purely current-carrying part of the field within uncertainties for most test cases. It is also found that the current-carrying part of the model field is relatively significant at the very location of the magnetic flux rope. This qualitatively explains the agreement between the magnetic helicity computed by the twist method and the helicity contributed purely by the current-carrying magnetic field.

  2. The Caribbean News Agency: Third World Model. Journalism Monographs Number 71.

    Science.gov (United States)

    Cuthbert, Marlene

    This monograph is a history of the Caribbean News Agency (CANA), which is jointly owned by private and public mass media of its region and independent of both governments and foreign news agencies. It is proposed that CANA may provide a unique model of an independent, regional third-world news agency. Sections of the monograph examine (1) CANA's…

  3. A new model for Assessment and Optimization of Number of Spare Transformers and their Locations in Distribution Systems

    Directory of Open Access Journals (Sweden)

    M Sedaghati

    2015-12-01

    Full Text Available In this paper, a new model has been presented to determine the number of spare transformers and their locations for distribution stations. The number of spare transformers must be so that they need minimum investment. Furthermore, they must be sufficient for replacing with transformers that have been damaged. For this reason, in this paper a new purpose function has been presented to maximize profit in distribution company’s budgeting and planning. For determining the number of spares that must be available in a stock room, this paper considers the number of spares and transformer’s fault at the same time. The number of spare transformers is determined so that at least one spare transformer will be available for replacing with the failed transformers. This paper considers time required for purchasing or repairing a failed transformer to determine the number of required spare transformers. Furthermore, whatever the number of spare equipment are increased, cost of maintenance will be increased, so an economic comparison must be done between reduced costs from reducing of outage time and increased costs from spare transformers existence.

  4. Model and scenario variations in predicted number of generations of Spodoptera litura Fab. on peanut during future climate change scenario.

    Science.gov (United States)

    Rao, Mathukumalli Srinivasa; Swathi, Pettem; Rao, Chitiprolu Anantha Rama; Rao, K V; Raju, B M K; Srinivas, Karlapudi; Manimanjari, Dammu; Maheswari, Mandapaka

    2015-01-01

    The present study features the estimation of number of generations of tobacco caterpillar, Spodoptera litura. Fab. on peanut crop at six locations in India using MarkSim, which provides General Circulation Model (GCM) of future data on daily maximum (T.max), minimum (T.min) air temperatures from six models viz., BCCR-BCM2.0, CNRM-CM3, CSIRO-Mk3.5, ECHams5, INCM-CM3.0 and MIROC3.2 along with an ensemble of the six from three emission scenarios (A2, A1B and B1). This data was used to predict the future pest scenarios following the growing degree days approach in four different climate periods viz., Baseline-1975, Near future (NF) -2020, Distant future (DF)-2050 and Very Distant future (VDF)-2080. It is predicted that more generations would occur during the three future climate periods with significant variation among scenarios and models. Among the seven models, 1-2 additional generations were predicted during DF and VDF due to higher future temperatures in CNRM-CM3, ECHams5 & CSIRO-Mk3.5 models. The temperature projections of these models indicated that the generation time would decrease by 18-22% over baseline. Analysis of variance (ANOVA) was used to partition the variation in the predicted number of generations and generation time of S. litura on peanut during crop season. Geographical location explained 34% of the total variation in number of generations, followed by time period (26%), model (1.74%) and scenario (0.74%). The remaining 14% of the variation was explained by interactions. Increased number of generations and reduction of generation time across the six peanut growing locations of India suggest that the incidence of S. litura may increase due to projected increase in temperatures in future climate change periods.

  5. Model and scenario variations in predicted number of generations of Spodoptera litura Fab. on peanut during future climate change scenario.

    Directory of Open Access Journals (Sweden)

    Mathukumalli Srinivasa Rao

    Full Text Available The present study features the estimation of number of generations of tobacco caterpillar, Spodoptera litura. Fab. on peanut crop at six locations in India using MarkSim, which provides General Circulation Model (GCM of future data on daily maximum (T.max, minimum (T.min air temperatures from six models viz., BCCR-BCM2.0, CNRM-CM3, CSIRO-Mk3.5, ECHams5, INCM-CM3.0 and MIROC3.2 along with an ensemble of the six from three emission scenarios (A2, A1B and B1. This data was used to predict the future pest scenarios following the growing degree days approach in four different climate periods viz., Baseline-1975, Near future (NF -2020, Distant future (DF-2050 and Very Distant future (VDF-2080. It is predicted that more generations would occur during the three future climate periods with significant variation among scenarios and models. Among the seven models, 1-2 additional generations were predicted during DF and VDF due to higher future temperatures in CNRM-CM3, ECHams5 & CSIRO-Mk3.5 models. The temperature projections of these models indicated that the generation time would decrease by 18-22% over baseline. Analysis of variance (ANOVA was used to partition the variation in the predicted number of generations and generation time of S. litura on peanut during crop season. Geographical location explained 34% of the total variation in number of generations, followed by time period (26%, model (1.74% and scenario (0.74%. The remaining 14% of the variation was explained by interactions. Increased number of generations and reduction of generation time across the six peanut growing locations of India suggest that the incidence of S. litura may increase due to projected increase in temperatures in future climate change periods.

  6. Female reproductive disorders

    DEFF Research Database (Denmark)

    Crain, D Andrew; Janssen, Sarah J; Edwards, Thea M

    2008-01-01

    To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive...... disruptions warrant evaluation of the impact of EDCs on female reproductive health....

  7. Large Prandtl number finite-amplitude thermal convection with Maxwell viscoelasticity. [earth mantle rheological model

    Science.gov (United States)

    Ivins, E. R.; Unti, T. W. J.; Phillips, R. J.

    1982-01-01

    It has long been known that the earth behaves viscoelastically. Viscoelasticity may be of importance in two aspects of mantle convection, including time-dependent behavior and local storage of recoverable work. The present investigation makes use of thermal convection in a box as a prototype of mantle flow. It is demonstrated that recoverable work can be important to the local mechanical energy balance in the descending lithosphere. It is shown that, even when assuming large viscoelastic parameters, an inherent time-dependence of viscoelastic convection appears only in local exchanges of mechanical energy. There is no strong exchange between buoyant potential energy and recoverable strain energy in the Rayleigh number range investigated. The investigation is mainly concerned with viscoelastic effects occurring on a buoyant time scale. It is found that viscoelastic effects have a negligible influence on the long term thermal energetics of mantle convection.

  8. Reproductive Medicine in Amphibians.

    Science.gov (United States)

    Chai, Norin

    2017-05-01

    Reproduction of amphibians includes ovulation, spermiation, fertilization, oviposition, larval stage and development, and metamorphosis. A problem at any stage could lead to reproductive failure. To stimulate reproduction, environmental conditions must be arranged to simulate changes in natural habits. Reproductive life history is well documented in amphibians; a thorough knowledge of this subject will aid the practitioner in diagnosis and treatment. Technologies for artificial reproduction are developing rapidly, and some protocols may be transferable to privately kept or endangered species. Reproductive tract disorders are rarely described; no bacterial or viral diseases are known that specifically target the amphibian reproductive system. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Naturalness and lepton number/flavor violation in inverse seesaw models

    Energy Technology Data Exchange (ETDEWEB)

    Haba, Naoyuki [Graduate School of Science and Engineering, Shimane University,1060, Nishikawatsu, Matsue, Shimane (Japan); Ishida, Hiroyuki [Graduate School of Science and Engineering, Shimane University,1060, Nishikawatsu, Matsue, Shimane (Japan); Physics Division, National Center for Theoretical Sciences,101, Section 2 Kuang Fu Road, Hsinchu, 300 Taiwan (China); Yamaguchi, Yuya [Graduate School of Science and Engineering, Shimane University,1060, Nishikawatsu, Matsue, Shimane (Japan); Department of Physics, Faculty of Science, Hokkaido University,Kita 9 Nishi 8, Kita-ku, Sapporo, Hokkaido (Japan)

    2016-11-02

    We introduce three right-handed neutrinos and three sterile neutrinos, and consider an inverse seesaw mechanism for neutrino mass generation. From naturalness point of view, their Majorana masses should be small, while it induces a large neutrino Yukawa coupling. Then, a neutrinoless double beta decay rate can be enhanced, and a sizable Higgs mass correction is inevitable. We find that the enhancement rate can be more than ten times compared with a standard prediction from light neutrino contribution alone, and an analytic form of heavy neutrino contributions to the Higgs mass correction. In addition, we numerically analyze the model, and find almost all parameter space of the model can be complementarily searched by future experiments of neutrinoless double beta decay and μ→e conversion.

  10. Cerebellar plasticity and motor learning deficits in a copy-number variation mouse model of autism.

    Science.gov (United States)

    Piochon, Claire; Kloth, Alexander D; Grasselli, Giorgio; Titley, Heather K; Nakayama, Hisako; Hashimoto, Kouichi; Wan, Vivian; Simmons, Dana H; Eissa, Tahra; Nakatani, Jin; Cherskov, Adriana; Miyazaki, Taisuke; Watanabe, Masahiko; Takumi, Toru; Kano, Masanobu; Wang, Samuel S-H; Hansel, Christian

    2014-11-24

    A common feature of autism spectrum disorder (ASD) is the impairment of motor control and learning, occurring in a majority of children with autism, consistent with perturbation in cerebellar function. Here we report alterations in motor behaviour and cerebellar synaptic plasticity in a mouse model (patDp/+) for the human 15q11-13 duplication, one of the most frequently observed genetic aberrations in autism. These mice show ASD-resembling social behaviour deficits. We find that in patDp/+ mice delay eyeblink conditioning--a form of cerebellum-dependent motor learning--is impaired, and observe deregulation of a putative cellular mechanism for motor learning, long-term depression (LTD) at parallel fibre-Purkinje cell synapses. Moreover, developmental elimination of surplus climbing fibres--a model for activity-dependent synaptic pruning--is impaired. These findings point to deficits in synaptic plasticity and pruning as potential causes for motor problems and abnormal circuit development in autism.

  11. Baryon number generation in a flipped SU(5) x U(1) model

    International Nuclear Information System (INIS)

    Campbell, B.; Hagelin, J.; Nanopoulos, D.V.; Olive, K.A.

    1988-01-01

    We consider the possibilities for generating a baryon asymmetry in the early universe in a flipped SU(5) x U(1) model inspired by the superstring. Depending on the temperature of the radiation background after inflation we can distinguish between two scenarios for baryogenesis: (1) After reheating the original SU(5) x U(1) symmetry is restored, or there was no inflation at all; (2) reheating after inflation is rather weak and SU(5) x U(1) is broken. In either case the asymmetry is generated by the out-of-equilibrium decays of a massive SU(3) x SU(2) x U(1) singlet field φ m . In the flipped SU(5) x U(1) model, gauge symmetry breaking is triggered by strong coupling phenomena, and is in general accompanied by the production of entropy. We examine constraints on the reheating temperature and the strong coupling scale in each of the scenarios. (orig.)

  12. Land use regression models for total particle number concentrations using 2D, 3D and semantic parameters

    Science.gov (United States)

    Ghassoun, Yahya; Löwner, Marc-Oliver

    2017-10-01

    Total particle number concentration (TNC) was studied in a 1 × 2 km area in Berlin, the capital of Germany by three Land Use Regression models (LUR). The estimation of TNC was established and compared using one 2D-LUR and two 3D-LUR models. All models predict total number concentrations TNC by using urban morphological (2D resp. 3D) and additional semantical parameters. 2D and semantical parameters were derived from Open Street Map data (OSM) whereas 3D parameters were derived from a CityGML-based 3D city model. While the models are capable to depict the spatial variation of TNC across the study area, the two 3D-LUR showed better results than the 2D-LUR. The 2D-LUR model explained 74% of the variance of TNC for the full data set with root mean square error (RMSE) of 4014 cm-3 while the 3D-LUR explained 79% of the variance with an RMSE of 3477 cm-3. The further introduction of a new spatial parameter, the Frontal Area Index (FAI) that represents the dynamic factor wind direction enhanced the 3D-LUR to explain 82% of the variance with RMSE of 3389 cm-3. Furthermore, the semantical parameters (e.g. streets type) played a significant role in all models.

  13. Reproductive Disorders in Snakes.

    Science.gov (United States)

    Di Girolamo, Nicola; Selleri, Paolo

    2017-05-01

    Reproduction of snakes is one of the challenging aspects of herpetology medicine. Due to the complexity of reproduction, several disorders may present before, during, or after this process. This article describes the physical examination, and radiographic, ultrasonographic, and endoscopic findings associated with reproductive disorders in snakes. Surgical techniques used to resolve reproductive disorders in snakes are described. Finally, common reproductive disorders in snakes are individually discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Application of random number generators in genetic algorithms to improve rainfall-runoff modelling

    Czech Academy of Sciences Publication Activity Database

    Chlumecký, M.; Buchtele, Josef; Richta, K.

    2017-01-01

    Roč. 553, October (2017), s. 350-355 ISSN 0022-1694 Institutional support: RVO:67985874 Keywords : genetic algorithm * optimisation * rainfall-runoff modeling * random generator Subject RIV: DA - Hydrology ; Limnology OBOR OECD: Hydrology Impact factor: 3.483, year: 2016 https://ac.els-cdn.com/S0022169417305516/1-s2.0-S0022169417305516-main.pdf?_tid=fa1bad8a-bd6a-11e7-8567-00000aab0f27&acdnat=1509365462_a1335d3d997e9eab19e23b1eee977705

  15. Autism spectrum disorder model mice: Focus on copy number variation and epigenetics.

    Science.gov (United States)

    Nakai, Nobuhiro; Otsuka, Susumu; Myung, Jihwan; Takumi, Toru

    2015-10-01

    Autism spectrum disorder (ASD) is gathering concerns in socially developed countries. ASD is a neuropsychiatric disorder of genetic origin with high prevalence of 1%-2%. The patients with ASD characteristically show impaired social skills. Today, many genetic studies identify numerous susceptible genes and genetic loci associated with ASD. Although some genetic factors can lead to abnormal brain function linked to ASD phenotypes, the pathogenic mechanism of ASD is still unclear. Here, we discuss a new mouse model for ASD as an advanced tool to understand the mechanism of ASD.

  16. Application of random number generators in genetic algorithms to improve rainfall-runoff modelling

    Czech Academy of Sciences Publication Activity Database

    Chlumecký, M.; Buchtele, Josef; Richta, K.

    2017-01-01

    Roč. 553, October (2017), s. 350-355 ISSN 0022-1694 Institutional support: RVO:67985874 Keywords : genetic algorithm * optimisation * rainfall-runoff modeling * random generator Subject RIV: DA - Hydrology ; Limnology OBOR OECD: Hydrology Impact factor: 3.483, year: 2016 https://ac.els- cdn .com/S0022169417305516/1-s2.0-S0022169417305516-main.pdf?_tid=fa1bad8a-bd6a-11e7-8567-00000aab0f27& amp ;acdnat=1509365462_a1335d3d997e9eab19e23b1eee977705

  17. Chronic stress is associated with reduced circulating hematopoietic progenitor cell number: A maternal caregiving model.

    Science.gov (United States)

    Aschbacher, Kirstin; Milush, Jeffrey M; Gilbert, Amanda; Almeida, Carlos; Sinclair, Elizabeth; Epling, Lorrie; Grenon, S Marlene; Marco, Elysa J; Puterman, Eli; Epel, Elissa

    2017-01-01

    Chronic psychological stress is a risk factor for cardiovascular disease and mortality. Circulating hematopoietic progenitor cells (CPCs) maintain vascular homeostasis, correlate with preclinical atherosclerosis, and prospectively predict cardiovascular events. We hypothesize that (1) chronic caregiving stress is related to reduced CPC number, and (2) this may be explained in part by negative interactions within the family. We investigated levels of stress and CPCs in 68 healthy mothers - 31 of these had children with an autism spectrum disorder (M-ASD) and 37 had neurotypical children (M-NT). Participants provided fasting blood samples, and CD45 + CD34 + KDR + and CD45 + CD133 + KDR + CPCs were assayed by flow cytometry. We averaged the blom-transformed scores of both CPCs to create one index. Participants completed the perceived stress scale (PSS), the inventory for depressive symptoms (IDS), and reported on daily interactions with their children and partners, averaged over 7 nights. M-ASD exhibited lower CPCs than M-NT (Cohen's d=0.83; p⩽0.01), controlling for age, BMI, and physical activity. Across the whole sample, positive interactions were related to higher CPCs, and negative interactions to lower CPCs (allp'scaregivers, child-related interpersonal stress appears to be a key psychological predictor of stress-related CVD risk. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Psychological stress and reproductive aging among pre-menopausal women.

    Science.gov (United States)

    Bleil, M E; Adler, N E; Pasch, L A; Sternfeld, B; Gregorich, S E; Rosen, M P; Cedars, M I

    2012-09-01

    Life history models suggest that biological preparation for current versus longer term reproduction is favored in environments of adversity. In this context, we present a model of reproductive aging in which environmental adversity is proposed to increase the number of growing follicles at the cost of hastening the depletion of the ovarian reserve over time. We evaluated this model by examining psychological stress in relation to reproductive aging indexed by antral follicle count (AFC), a marker of total ovarian reserve. We hypothesized that stress would be related to (i) higher AFC in younger women, reflecting greater reproductive readiness as well as (ii) greater AFC loss across women, reflecting more accelerated reproductive aging. In a multi-ethnic, community sample of 979 participants [ages 25-45 (mean (standard deviation) = 35.2 (5.5)); 27.5% Caucasian] in the Ovarian Aging study, an investigation of the correlates of reproductive aging, the interaction of age-x-stress was assessed in relation to AFC to determine whether AFC and AFC loss varied across women experiencing differing levels of stress. Stress was assessed by the perceived stress scale and AFC was assessed by summing the total number of antral follicles visible by transvaginal ultrasound. In linear regression examining AFC as the dependent variable, covariates (race/ethnicity, socio-economic status, menarcheal age, hormone-containing medication for birth control, parity, cigarette smoking, bodymass index, waist-to-hip ratio) and age were entered on step 1, stress on step 2 and the interaction term (age-x-stress) on step 3. On step 3, significant main effects showed that older age was related to lower AFC (b = -0.882, P = 0.000) and greater stress was related to higher AFC (b = 0.545, P = 0.005). Follow-up analyses showed that the main effect of stress on AFC was present in the younger women only. A significant interaction term (b = -0.036, P = 0.031) showed the relationship between age and AFC

  19. A theoretical model of a wake of a body towed in a stratified fluid at large Reynolds and Froude numbers

    Directory of Open Access Journals (Sweden)

    Y. I. Troitskaya

    2006-01-01

    Full Text Available The objective of the present paper is to develop a theoretical model describing the evolution of a turbulent wake behind a towed sphere in a stably stratified fluid at large Froude and Reynolds numbers. The wake flow is considered as a quasi two-dimensional (2-D turbulent jet flow whose dynamics is governed by the momentum transfer from the mean flow to a quasi-2-D sinuous mode growing due to hydrodynamic instability. The model employs a quasi-linear approximation to describe this momentum transfer. The model scaling coefficients are defined with the use of available experimental data, and the performance of the model is verified by comparison with the results of a direct numerical simulation of a 2-D turbulent jet flow. The model prediction for the temporal development of the wake axis mean velocity is found to be in good agreement with the experimental data obtained by Spedding (1997.

  20. Cerebellar Plasticity and Motor Learning Deficits in a Copy Number Variation Mouse Model of Autism

    Science.gov (United States)

    Piochon, Claire; Kloth, Alexander D; Grasselli, Giorgio; Titley, Heather K; Nakayama, Hisako; Hashimoto, Kouichi; Wan, Vivian; Simmons, Dana H; Eissa, Tahra; Nakatani, Jin; Cherskov, Adriana; Miyazaki, Taisuke; Watanabe, Masahiko; Takumi, Toru; Kano, Masanobu; Wang, Samuel S-H; Hansel, Christian

    2014-01-01

    A common feature of autism spectrum disorder (ASD) is the impairment of motor control and learning, occurring in a majority of children with autism, consistent with perturbation in cerebellar function. Here we report alterations in motor behavior and cerebellar synaptic plasticity in a mouse model (patDp/+) for the human 15q11-13 duplication, one of the most frequently observed genetic aberrations in autism. These mice show ASD-resembling social behavior deficits. We find that in patDp/+ mice delay eyeblink conditioning—a form of cerebellum-dependent motor learning—is impaired, and observe deregulation of a putative cellular mechanism for motor learning, long-term depression (LTD) at parallel fiber-Purkinje cell synapses. Moreover, developmental elimination of surplus climbing fibers—a model for activity-dependent synaptic pruning—is impaired. These findings point to deficits in synaptic plasticity and pruning as potential causes for motor problems and abnormal circuit development in autism. PMID:25418414

  1. Fibrous Synovium Releases Higher Numbers of Mesenchymal Stem Cells Than Adipose Synovium in a Suspended Synovium Culture Model.

    Science.gov (United States)

    Katagiri, Kenta; Matsukura, Yu; Muneta, Takeshi; Ozeki, Nobutake; Mizuno, Mitsuru; Katano, Hisako; Sekiya, Ichiro

    2017-04-01

    To develop an in vitro model, the "suspended synovium culture model," to demonstrate the mobilization of mesenchymal stem cells (MSCs) from the synovium into a noncontacted culture dish through culture medium. In addition, to examine which synovium, fibrous synovium or adipose synovium, released more MSCs in the knee with osteoarthritis. Human synovial tissue was harvested during total knee arthroplasty from knee joints of 34 patients with osteoarthritis (28 patients: only fibrous synovium, 6 patients: fibrous and adipose synovium). One gram of synovium was suspended with a thread in a bottle containing 40 mL of culture medium and a 3.5-cm-diameter culture dish at the bottom. After 7 days, the culture dish in the bottle was examined. For the cells harvested, multipotentiality and surface epitopes were analyzed. The numbers of colonies derived from fibrous synovium and adipose synovium were also compared. Colonies of spindle-shaped cells were observed in the culture dish in all 28 donors. Colonies numbered 26 on average, and the cells derived from colony-forming cells had multipotentiality for chondrogenesis, adipogenesis, calcification, and surface epitopes similar to MSCs. The number was colonies was significantly higher in fibrous synovium than in adipose synovium (P < .05, n = 6). We developed a suspended synovium culture model. Suspended synovium was able to release MSCs into a noncontacted culture dish through medium in a bottle. Fibrous synovium was found to release greater numbers of MSCs than adipose synovium in our culture model. CLINICAL RELEVANCE: This model could be a valuable tool to screen drugs capable of releasing MSCs from the synovium into synovial fluid. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  2. WaveCNV: allele-specific copy number alterations in primary tumors and xenograft models from next-generation sequencing.

    Science.gov (United States)

    Holt, Carson; Losic, Bojan; Pai, Deepa; Zhao, Zhen; Trinh, Quang; Syam, Sujata; Arshadi, Niloofar; Jang, Gun Ho; Ali, Johar; Beck, Tim; McPherson, John; Muthuswamy, Lakshmi B

    2014-03-15

    Copy number variations (CNVs) are a major source of genomic variability and are especially significant in cancer. Until recently microarray technologies have been used to characterize CNVs in genomes. However, advances in next-generation sequencing technology offer significant opportunities to deduce copy number directly from genome sequencing data. Unfortunately cancer genomes differ from normal genomes in several aspects that make them far less amenable to copy number detection. For example, cancer genomes are often aneuploid and an admixture of diploid/non-tumor cell fractions. Also patient-derived xenograft models can be laden with mouse contamination that strongly affects accurate assignment of copy number. Hence, there is a need to develop analytical tools that can take into account cancer-specific parameters for detecting CNVs directly from genome sequencing data. We have developed WaveCNV, a software package to identify copy number alterations by detecting breakpoints of CNVs using translation-invariant discrete wavelet transforms and assign digitized copy numbers to each event using next-generation sequencing data. We also assign alleles specifying the chromosomal ratio following duplication/loss. We verified copy number calls using both microarray (correlation coefficient 0.97) and quantitative polymerase chain reaction (correlation coefficient 0.94) and found them to be highly concordant. We demonstrate its utility in pancreatic primary and xenograft sequencing data. Source code and executables are available at https://github.com/WaveCNV. The segmentation algorithm is implemented in MATLAB, and copy number assignment is implemented Perl. lakshmi.muthuswamy@gmail.com Supplementary data are available at Bioinformatics online.

  3. Genomic imprinting and assisted reproduction

    Directory of Open Access Journals (Sweden)

    Chaillet J Richard

    2004-10-01

    Full Text Available Abstract Imprinted genes exhibit a parent-of-origin specific pattern of expression. Such genes have been shown to be targets of molecular defects in particular genetic syndromes such as Beckwith-Wiedemann and Angelman syndromes. Recent reports have raised concern about the possibility that assisted reproduction techniques, such as in vitro fertilization or intracytoplasmic sperm injection, might cause genomic imprinting disorders. The number of reported cases of those disorders is still too small to draw firm conclusions and the safety of these widely used assisted reproduction techniques needs to be further evaluated.

  4. The percentage of macrophage numbers in rat model of sciatic nerve crush injury

    Directory of Open Access Journals (Sweden)

    Satrio Wicaksono

    2016-02-01

    Full Text Available ABSTRACT Excessive accumulation of macrophages in sciatic nerve fascicles inhibits regeneration of peripheral nerves. The aim of this study is to determine the percentage of the macrophages inside and outside of the fascicles at the proximal, at the site of injury and at the distal segment of rat model of sciatic nerve crush injury. Thirty male 3 months age Wistar rats of 200-230 g were divided into sham-operation group and crush injury group. Termination was performed on day 3, 7, and 14 after crush injury. Immunohistochemical examination was done using anti CD68 antibody. Counting of immunopositive and immunonegative cells was done on three representative fields for extrafascicular and intrafascicular area of proximal, injury and distal segments. The data was presented as percentage of immunopositive cells. The percentage of the macrophages was significantly increased in crush injury group compared to the sham-operated group in all segments of the peripheral nerves. While the percentage of macrophages outside fascicle in all segments of sciatic nerve and within the fascicle in the proximal segment reached its peak on day 3, the percentage of macrophages within the fascicles at the site of injury and distal segments reached the peak later at day 7. In conclusions, accumulation of macrophages outside the nerve fascicles occurs at the beginning of the injury, and then followed later by the accumulation of macrophages within nerve fascicles

  5. Heparin for assisted reproduction.

    Science.gov (United States)

    Akhtar, Muhammad A; Sur, Shyamaly; Raine-Fenning, Nick; Jayaprakasan, Kannamannadiar; Thornton, Jim G; Quenby, Siobhan

    2013-08-17

    heterogeneity). There was also a significant improvement in the clinical pregnancy rate with use of LMWH (OR 1.61, 95% CI 1.03 to 2.53, three studies, 386 women, I(2) = 29%, very low quality evidence with low heterogeneity).However these findings should be interpreted with extreme caution as they were dependent upon the choice of statistical method: they were no longer statistically significant when a random-effects model was used.Adverse events were poorly reported in all included studies, with no comparative data available. However, LMWH did cause adverse effects including bruising, ecchymosis, bleeding, thrombocytopenia and allergic reactions. It appeared that these adverse effects were increased if heparin therapy was used over a longer duration. The results of this Cochrane review of three randomised controlled trials with a total of 386 women suggested that peri-implantation LMWH in assisted reproduction treatment (ART) cycles may improve the live birth rate in women undergoing assisted reproduction. However, these results were dependent on small low quality studies with substantial heterogeneity, and were sensitive to the choice of statistical model. There were side effects reported with use of heparin, including bruising and bleeding, and no reliable data on long-term effects. The results do not justify this use of heparin outside well-conducted research trials.These findings need to be further investigated with well-designed, adequately powered, double-blind, randomised, placebo-controlled, multicentre trials. Further investigations could also focus on the effects of the local (uterine) and not systemic application of heparin during ART.

  6. Reproductive toxicity: Male and female reproductive systems as targets for chemical injury

    Energy Technology Data Exchange (ETDEWEB)

    Mattison, D.R.; Plowchalk, D.R.; Meadows, M.J.; Al-Juburi, A.Z.; Gandy, J.; Malek, A. (Univ. of Arkansas for Medical Sciences, Little Rock (USA))

    1990-03-01

    On the basis of current knowledge of reproductive biology and toxicology, it is apparent that chemicals affecting reproduction may elicit their effects at a number of sites in both the male and the female reproductive system. This multiplicity of targets is attributable to the dynamic nature of the reproductive system, in which the hypothalamic-pituitary-gonadal axis is controlled by precise positive and negative feedback mechanisms among its components. Interference by a xenobiotic at any level in either the male or the female reproductive system may ultimately impair hypothalamic or pituitary function. Normal gonadal processes such as spermatogenesis or oogenesis, ejaculation or ovulation, hormone production by Leydig or granulosa cells, and the structure or function of the accessory reproductive structures (e.g., epididymis, fallopian tube) also appear vulnerable to xenobiotics. The reproductive system is a complex one that requires local and circulating hormones for control. This brief review illustrates a system for characterizing the mechanism of action of reproductive toxicants, as well as for defining the sites available for disruption of reproduction. Unfortunately, at present, data addressing the actual vulnerability of reproduction are sorely lacking. However, when experiments have been conducted and combined with epidemiologic data or clinical observation, it has been possible to demonstrate impairment of reproductive processes by xenobiotics. The role of environmental exposure to xenobiotics in the increase in infertility that has been observed remains to be defined. 87 references.

  7. Past performance of assisted reproduction technologies as a model to predict future progress: a proposed addendum to Moore's law.

    Science.gov (United States)

    Cohen, Jacques; Alikani, Mina; Bisignano, Alexander

    2012-12-01

    The ultimate goal of IVF is to achieve healthy, single, live births following each single-embryo transfer. A timeline for this eventuality has never been defined. National implantation rates from 2003-2010 provided by the Society for Assisted Reproductive Technologies (SART) in the USA were evaluated. Regression analysis was applied to the annual trends. A high correlation was noted showing a linear increase from year to year ranging between 0.3% and 1.5% when maternal age was not higher than 42. This relationship can be retrospectively applied to earlier SART data reports. This incline may be partly technology driven and resembles Moore's law, which describes annual improvements in microchip performance. Based on the assumption that technology will continue to drive progress, the length of time required to reach 100% implantation was calculated. The interval varied between 43 years (AD 2053) for the youngest age group (Assisted Reproductive Technologies (SART; www.sart.org). Through SART, individual clinic's outcomes may be assessed. Although live birth and pregnancy are considered the gold standard of success, the investigators took the approach that those outcomes are often biased due to transfer of multiple embryos. The present analysis was therefore performed on individual embryos, by using the implantation rate to compare national and individual clinic datasets. National implantation rates show a linear increase from year to year ranging between 0.3% and 1.5% for patients aged technology driven. This is an intriguing effect also seen in the computer industry where there has been a doubling of computer speed and memory for the past 47 years, a phenomenon anticipated by Moore's law. We predict that the annual increase in implantation will also continue as new technologies become available. Based on current trends, the length of time for 100% implantation rates was calculated. Time to achieving 100% implantation varied between 43 years (AD 2053) for the youngest

  8. Modeling a Conventional Electroporation Pulse Train: Decreased Pore Number, Cumulative Calcium Transport and an Example of Electrosensitization.

    Science.gov (United States)

    Son, Reuben S; Gowrishankar, Thiruvallur R; Smith, Kyle C; Weaver, James C

    2016-03-01

    Pulse trains are widely used in electroporation (EP) for both general biomedical research and clinical applications such as nonthermal tumor ablation. Here we use a computational method based on a meshed transport network to investigate a cell system model's response to a train of identical, evenly spaced electric field pulses. We obtain an unexpected result: the number of membrane pores decreases during the application of twenty 1.0 kV/cm, 100 μs pulses, delivered at 1 Hz. This pulse train initially creates 13,000 membrane pores, but pore number decreases by a factor of 15 to about 830 pores throughout subsequent pulses. We conclude that pore number can greatly diminish during a train of identical pulses, with direct consequences for the transport of solutes across an electroporated membrane. Although application of additional pulses is generally intended to increase the effects of EP, we show that these pulses do not significantly enhance calcium delivery into the cell. Instead, calcium delivery can be significantly increased by varying inter-pulse intervals. We show that inserting a 300-s interruption midway in a widely used eight-pulse train (a protocol for electrosensitization) yields a ∼ twofold delivery increase. Overall, our modeling shows support for electrosensitization, in which multiple pulse protocols that maximize pore number over time can yield significant increase of transport of calcium compared to standard pulse trains.

  9. Bayesian Nonparametric Hidden Markov Models with application to the analysis of copy-number-variation in mammalian genomes.

    Science.gov (United States)

    Yau, C; Papaspiliopoulos, O; Roberts, G O; Holmes, C

    2011-01-01

    We consider the development of Bayesian Nonparametric methods for product partition models such as Hidden Markov Models and change point models. Our approach uses a Mixture of Dirichlet Process (MDP) model for the unknown sampling distribution (likelihood) for the observations arising in each state and a computationally efficient data augmentation scheme to aid inference. The method uses novel MCMC methodology which combines recent retrospective sampling methods with the use of slice sampler variables. The methodology is computationally efficient, both in terms of MCMC mixing properties, and robustness to the length of the time series being investigated. Moreover, the method is easy to implement requiring little or no user-interaction. We apply our methodology to the analysis of genomic copy number variation.

  10. Generalization techniques to reduce the number of volume elements for terrain effect calculations in fully analytical gravitational modelling

    Science.gov (United States)

    Benedek, Judit; Papp, Gábor; Kalmár, János

    2018-04-01

    Beyond rectangular prism polyhedron, as a discrete volume element, can also be used to model the density distribution inside 3D geological structures. The calculation of the closed formulae given for the gravitational potential and its higher-order derivatives, however, needs twice more runtime than that of the rectangular prism computations. Although the more detailed the better principle is generally accepted it is basically true only for errorless data. As soon as errors are present any forward gravitational calculation from the model is only a possible realization of the true force field on the significance level determined by the errors. So if one really considers the reliability of input data used in the calculations then sometimes the "less" can be equivalent to the "more" in statistical sense. As a consequence the processing time of the related complex formulae can be significantly reduced by the optimization of the number of volume elements based on the accuracy estimates of the input data. New algorithms are proposed to minimize the number of model elements defined both in local and in global coordinate systems. Common gravity field modelling programs generate optimized models for every computation points ( dynamic approach), whereas the static approach provides only one optimized model for all. Based on the static approach two different algorithms were developed. The grid-based algorithm starts with the maximum resolution polyhedral model defined by 3-3 points of each grid cell and generates a new polyhedral surface defined by points selected from the grid. The other algorithm is more general; it works also for irregularly distributed data (scattered points) connected by triangulation. Beyond the description of the optimization schemes some applications of these algorithms in regional and local gravity field modelling are presented too. The efficiency of the static approaches may provide even more than 90% reduction in computation time in favourable

  11. Eksperimentasi Model Numbered Heads Together Dengan Make a Match (Nht Mm) Dan Numbered Heads Together Dengan Bamboo Dancing (Nht Bd) Ditinjau Dari Kecerdasan Interpersonal

    OpenAIRE

    Dewi, Arianti Puspita; Kusmayadi, Tri Atmojo; Usodo, Budi

    2014-01-01

    The purposes of this research were to determine: (1) which students mathematics achievement would be better, student given NHT MM, NHT BD, or direct learning model, (2) which students mathematics achievement would be better, student with interpersonal intelligence of high, medium or low, (3) which students mathematics achievement would be better, student with interpersonal intelligence of high, medium, or low on each learning model, (4) which student mathematics achievement would be better, ...

  12. Medical Updates Number 5 to the International Space Station Probability Risk Assessment (PRA) Model Using the Integrated Medical Model

    Science.gov (United States)

    Butler, Doug; Bauman, David; Johnson-Throop, Kathy

    2011-01-01

    The Integrated Medical Model (IMM) Project has been developing a probabilistic risk assessment tool, the IMM, to help evaluate in-flight crew health needs and impacts to the mission due to medical events. This package is a follow-up to a data package provided in June 2009. The IMM currently represents 83 medical conditions and associated ISS resources required to mitigate medical events. IMM end state forecasts relevant to the ISS PRA model include evacuation (EVAC) and loss of crew life (LOCL). The current version of the IMM provides the basis for the operational version of IMM expected in the January 2011 timeframe. The objectives of this data package are: 1. To provide a preliminary understanding of medical risk data used to update the ISS PRA Model. The IMM has had limited validation and an initial characterization of maturity has been completed using NASA STD 7009 Standard for Models and Simulation. The IMM has been internally validated by IMM personnel but has not been validated by an independent body external to the IMM Project. 2. To support a continued dialogue between the ISS PRA and IMM teams. To ensure accurate data interpretation, and that IMM output format and content meets the needs of the ISS Risk Management Office and ISS PRA Model, periodic discussions are anticipated between the risk teams. 3. To help assess the differences between the current ISS PRA and IMM medical risk forecasts of EVAC and LOCL. Follow-on activities are anticipated based on the differences between the current ISS PRA medical risk data and the latest medical risk data produced by IMM.

  13. Chemosignals, hormones, and amphibian reproduction.

    Science.gov (United States)

    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. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. ROLE OF SEROTONIN IN FISH REPRODUCTION

    Directory of Open Access Journals (Sweden)

    Parvathy ePrasad

    2015-06-01

    Full Text Available 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 behaviours, gonadotropin release and gonadotropin-release hormone (GnRH secretion. However, the serotonin system in teleost may 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.

  15. Predictors of the number of under-five malnourished children in Bangladesh: application of the generalized poisson regression model.

    Science.gov (United States)

    Islam, Mohammad Mafijul; Alam, Morshed; Tariquzaman, Md; Kabir, Mohammad Alamgir; Pervin, Rokhsona; Begum, Munni; Khan, Md Mobarak Hossain

    2013-01-08

    Malnutrition is one of the principal causes of child mortality in developing countries including Bangladesh. According to our knowledge, most of the available studies, that addressed the issue of malnutrition among under-five children, considered the categorical (dichotomous/polychotomous) outcome variables and applied logistic regression (binary/multinomial) to find their predictors. In this study malnutrition variable (i.e. outcome) is defined as the number of under-five malnourished children in a family, which is a non-negative count variable. The purposes of the study are (i) to demonstrate the applicability of the generalized Poisson regression (GPR) model as an alternative of other statistical methods and (ii) to find some predictors of this outcome variable. The data is extracted from the Bangladesh Demographic and Health Survey (BDHS) 2007. Briefly, this survey employs a nationally representative sample which is based on a two-stage stratified sample of households. A total of 4,460 under-five children is analysed using various statistical techniques namely Chi-square test and GPR model. The GPR model (as compared to the standard Poisson regression and negative Binomial regression) is found to be justified to study the above-mentioned outcome variable because of its under-dispersion (variance variable namely mother's education, father's education, wealth index, sanitation status, source of drinking water, and total number of children ever born to a woman. Consistencies of our findings in light of many other studies suggest that the GPR model is an ideal alternative of other statistical models to analyse the number of under-five malnourished children in a family. Strategies based on significant predictors may improve the nutritional status of children in Bangladesh.

  16. Random forest predictive modeling of mineral prospectivity with small number of prospects and data with missing values in Abra (Philippines)

    Science.gov (United States)

    Carranza, Emmanuel John M.; Laborte, Alice G.

    2015-01-01

    Machine learning methods that have been used in data-driven predictive modeling of mineral prospectivity (e.g., artificial neural networks) invariably require large number of training prospect/locations and are unable to handle missing values in certain evidential data. The Random Forests (RF) algorithm, which is a machine learning method, has recently been applied to data-driven predictive mapping of mineral prospectivity, and so it is instructive to further study its efficacy in this particular field. This case study, carried out using data from Abra (Philippines), examines (a) if RF modeling can be used for data-driven modeling of mineral prospectivity in areas with a few (i.e., individual layers of evidential data. Furthermore, RF modeling can handle missing values in evidential data through an RF-based imputation technique whereas in WofE modeling values are simply represented by zero weights. Therefore, the RF algorithm is potentially more useful than existing methods that are currently used for data-driven predictive mapping of mineral prospectivity. In particular, it is not a purely black-box method like artificial neural networks in the context of data-driven predictive modeling of mineral prospectivity. However, further testing of the method in other areas with a few mineral occurrences is needed to fully investigate its usefulness in data-driven predictive modeling of mineral prospectivity.

  17. A high-throughput method for assessing chemical toxicity using a Caenorhabditis elegans reproduction assay

    International Nuclear Information System (INIS)

    Boyd, Windy A.; McBride, Sandra J.; Rice, Julie R.; Snyder, Daniel W.; Freedman, Jonathan H.

    2010-01-01

    The National Research Council has outlined the need for non-mammalian toxicological models to test the potential health effects of a large number of chemicals while also reducing the use of traditional animal models. The nematode Caenorhabditis elegans is an attractive alternative model because of its well-characterized and evolutionarily conserved biology, low cost, and ability to be used in high-throughput screening. A high-throughput method is described for quantifying the reproductive capacity of C. elegans exposed to chemicals for 48 h from the last larval stage (L4) to adulthood using a COPAS Biosort. Initially, the effects of exposure conditions that could influence reproduction were defined. Concentrations of DMSO vehicle ≤ 1% did not affect reproduction. Previous studies indicated that C. elegans may be influenced by exposure to low pH conditions. At pHs greater than 4.5, C. elegans reproduction was not affected; however below this pH there was a significant decrease in the number of offspring. Cadmium chloride was chosen as a model toxicant to verify that automated measurements were comparable to those of traditional observational studies. EC 50 values for cadmium for automated measurements (176-192 μM) were comparable to those previously reported for a 72-h exposure using manual counting (151 μM). The toxicity of seven test toxicants on C. elegans reproduction was highly correlative with rodent lethality suggesting that this assay may be useful in predicting the potential toxicity of chemicals in other organisms.

  18. Human reproduction: current status.

    Science.gov (United States)

    Izzo, Carlos Roberto; Monteleone, Pedro Augusto Araújo; Serafini, Paulo C

    2015-01-01

    The concern about the maintenance of the human species has existed since the earliest civilizations. Progress in the diagnosis and treatment of infertility has led to the development of assisted reproductive techniques (ART) which, along with the evolution of genetics and molecular biology studies, have contributed in a concrete way to the management of infertile couples. Classic in vitro fertilization was initially developed 35 years ago for the treatment of women with tubal blockage, however, it remains inaccessible to a significant proportion of infertile couples around the world. This can be explained by the lack of specialized clinics in some countries and by the high cost of the procedures. Efforts have been employed to increase the number of treatment cycles for assisted reproduction, as for example, the creation of low-cost programs. Even today, infertility remains a problem of global proportions, affecting millions of couples. The estimate of the incidence of infertility is uncertain, mainly because of the criteria used for its definition. This article aims to review the most important aspects, succinctly, regarding the incidence, etiology, and treatment options available to infertile couples.

  19. Rare hybrid swarm of Pilosella polymastix × P. officinarum: cytotype structure and modes of reproduction

    Czech Academy of Sciences Publication Activity Database

    Krahulec, František; Krahulcová, Anna; Hlaváček, R.

    2014-01-01

    Roč. 86, č. 2 (2014), s. 179-192 ISSN 0032-7786 R&D Projects: GA ČR GAP506/10/1363; GA ČR GA206/08/0890 Institutional support: RVO:67985939 Keywords : chromosome numbers * hybrid swarm composition * reproductive models Subject RIV: EF - Botanics Impact factor: 4.104, year: 2014

  20. Population dynamics with a mixed type of sexual and asexual reproduction in a fluctuating environment

    Science.gov (United States)

    2012-01-01

    Background Carassius gibelio, a cyprinid fish from Eurasia, has the ability to reproduce both sexually and asexually. This fish is also known as an invasive species which colonized almost all continental Europe, most likely originating from Asia and Eastern Europe. Populations of both sexually and asexually reproducing individuals exist in sympatry. In this study we try to elucidate the advantages of such a mixed type of reproduction. We investigate the dynamics of two sympatric populations with sexual and asexual reproduction in a periodically fluctuating environment. We define an individual-based computational model in which genotypes are represented by L loci, and the environment is composed of L resources for which the two populations compete. Results Our model demonstrates advantageous population dynamics where the optimal percentage of asexual reproduction depends on selection strength, on the number of selected loci and on the timescale of environmental fluctuations. We show that the sexual reproduction is necessary for "generating" fit genotypes, while the asexual reproduction is suitable for "amplifying" them. The simulations show that the optimal percentage of asexual reproduction increases with the length of the environment stability period and decrease with the strength of the selection and the number of loci. Conclusions In this paper we addressed the advantages of a mixed type of sexual and asexual reproduction in a changing environment and explored the idea that a species that is able to adapt itself to environmental fluctuation can easily colonize a new habitat. Our results could provide a possible explanation for the rapid and efficient invasion of species with a variable ratio of sexual and asexual reproduction such as Carassius gibelio. PMID:22489797

  1. Children's Concepts of Reproduction

    Science.gov (United States)

    Moore, James E.; Kendall, Diane G.

    1971-01-01

    Results of this study provide little support for either Freudian or Piagetian theorizing about what the young child thinks of reproduction. Implications for sex education and reproduction information are presented. (Author/CJ)

  2. Reproductive Aging in Women

    Science.gov (United States)

    ... Cell Research SART's FAQs about In Vitro Fertilization REPRODUCTIVE HEALTH TOPICS Topics Index NEWS AND PUBLICATIONS Publications ... of the links in the navigation bar. FAQs Reproductive Health Topics News and Publications Resources About ASRM ...

  3. Assisted Reproductive Technologies

    Science.gov (United States)

    ... and Research Fertility and Sterility Journal of Assisted Reproduction and Genetics Ethics Committee Opinions and Webinars Practice ... Donate copyright 1996 - 2018 ASRM, American Society for Reproductive Medicine. All Rights Reserved. ASRM Non Discrimination Policy ...

  4. Society of Reproductive Surgeons

    Science.gov (United States)

    ... About Officers Mission Statement Fellowship The Role of Reproductive Surgeons Bylaws Membership Benefits FAQ Registry Discussion Directory Publications Fertility and Sterility Journal of Assisted Reproduction and Genetics (JARG) Newsletters Participate Post a Message ...

  5. Squalus cubensis Reproduction Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Reproductive data from Squalus cubensis (Cuban dogfish) were opportunistically collected from 2005-2012. Data include those necessary to examine reproductive cycle,...

  6. Comparison of INAR(1)-Poisson model and Markov prediction model in forecasting the number of DHF patients in west java Indonesia

    Science.gov (United States)

    Ahdika, Atina; Lusiyana, Novyan

    2017-02-01

    World Health Organization (WHO) noted Indonesia as the country with the highest dengue (DHF) cases in Southeast Asia. There are no vaccine and specific treatment for DHF. One of the efforts which can be done by both government and resident is doing a prevention action. In statistics, there are some methods to predict the number of DHF cases to be used as the reference to prevent the DHF cases. In this paper, a discrete time series model, INAR(1)-Poisson model in specific, and Markov prediction model are used to predict the number of DHF patients in West Java Indonesia. The result shows that MPM is the best model since it has the smallest value of MAE (mean absolute error) and MAPE (mean absolute percentage error).

  7. Bounds on the number of bound states in the transfer matrix spectrum for some weakly correlated lattice models

    International Nuclear Information System (INIS)

    O’Carroll, Michael

    2012-01-01

    We consider the interaction of particles in weakly correlated lattice quantum field theories. In the imaginary time functional integral formulation of these theories there is a relative coordinate lattice Schroedinger operator H which approximately describes the interaction of these particles. Scalar and vector spin, QCD and Gross-Neveu models are included in these theories. In the weakly correlated regime H=H o +W where H o =−γΔ l , 0 l is the d-dimensional lattice Laplacian: γ=β, the inverse temperature for spin systems and γ=κ 3 where κ is the hopping parameter for QCD. W is a self-adjoint potential operator which may have non-local contributions but obeys the bound ‖W(x, y)‖⩽cexp ( −a(‖x‖+‖y‖)), a large: exp−a=β/β o (1/2) (κ/κ o ) for spin (QCD) models. H o , W, and H act in l 2 (Z d ), d⩾ 1. The spectrum of H below zero is known to be discrete and we obtain bounds on the number of states below zero. This number depends on the short range properties of W, i.e., the long range tail does not increase the number of states.

  8. The effect of numbered heads together (NHT) cooperative learning model on the cognitive achievement of students with different academic ability

    Science.gov (United States)

    Leasa, Marleny; Duran Corebima, Aloysius

    2017-01-01

    Learning models and academic ability may affect students’ achievement in science. This study, thus aimed to investigate the effect of numbered heads together (NHT) cooperative learning model on elementary students’ cognitive achievement in natural science. This study employed a quasi-experimental design with pretest-posttest non-equivalent control group with 2 x 2 factorial. There were two learning models compared NHT and the conventional, and two academic ability high and low. The results of ana Cova test confirmed the difference in the students’ cognitive achievement based on learning models and general academic ability. However, the interaction between learning models and academic ability did not affect the students’ cognitive achievement. In conclusion, teachers are strongly recommended to be more creative in designing learning using other types of cooperative learning models. Also, schools are required to create a better learning environment which is more cooperative to avoid unfair competition among students in the classroom and as a result improve the students’ academic ability. Further research needs to be conducted to explore the contribution of other aspects in cooperative learning toward cognitive achievement of students with different academic ability.

  9. The Effect of Sample Size and Data Numbering on Precision of Calibration Model to predict Soil Properties

    Directory of Open Access Journals (Sweden)

    H Mohamadi Monavar

    2017-10-01

    Full Text Available Introduction Precision agriculture (PA is a technology that measures and manages within-field variability, such as physical and chemical properties of soil. The nondestructive and rapid VIS-NIR technology detected a significant correlation between reflectance spectra and the physical and chemical properties of soil. On the other hand, quantitatively predict of soil factors such as nitrogen, carbon, cation exchange capacity and the amount of clay in precision farming is very important. The emphasis of this paper is comparing different techniques of choosing calibration samples such as randomly selected method, chemical data and also based on PCA. Since increasing the number of samples is usually time-consuming and costly, then in this study, the best sampling way -in available methods- was predicted for calibration models. In addition, the effect of sample size on the accuracy of the calibration and validation models was analyzed. Materials and Methods Two hundred and ten soil samples were collected from cultivated farm located in Avarzaman in Hamedan province, Iran. The crop rotation was mostly potato and wheat. Samples were collected from a depth of 20 cm above ground and passed through a 2 mm sieve and air dried at room temperature. Chemical analysis was performed in the soil science laboratory, faculty of agriculture engineering, Bu-ali Sina University, Hamadan, Iran. Two Spectrometer (AvaSpec-ULS 2048- UV-VIS and (FT-NIR100N were used to measure the spectral bands which cover the UV-Vis and NIR region (220-2200 nm. Each soil sample was uniformly tiled in a petri dish and was scanned 20 times. Then the pre-processing methods of multivariate scatter correction (MSC and base line correction (BC were applied on the raw signals using Unscrambler software. The samples were divided into two groups: one group for calibration 105 and the second group was used for validation. Each time, 15 samples were selected randomly and tested the accuracy of

  10. Selective Reproduction

    DEFF Research Database (Denmark)

    Svendsen, Mette N.

    2015-01-01

    This article employs a multi-species perspective in investigating how life's worth is negotiated in the field of neonatology in Denmark. It does so by comparing decision-making processes about human infants in the Danish neonatal intensive care unit with those associated with piglets who serve...... as models for the premature infants in research experiments within neonatology. While the comparison is unusual, the article argues that there are parallels across the decision-making processes that shape the lives and deaths of infants and pigs alike. Collectivities or the lack thereof as well...

  11. Reduced synapse and axon numbers in the prefrontal cortex of rats subjected to a chronic stress model for depression

    DEFF Research Database (Denmark)

    Csabai, Dávid; Wiborg, Ove; Czéh, Boldizsár

    2018-01-01

    Stressful experiences can induce structural changes in neurons of the limbic system. These cellular changes contribute to the development of stress-induced psychopathologies like depressive disorders. In the prefrontal cortex of chronically stressed animals, reduced dendritic length and spine loss...... have been reported. This loss of dendritic material should consequently result in synapse loss as well, because of the reduced dendritic surface. But so far, no one studied synapse numbers in the prefrontal cortex of chronically stressed animals. Here, we examined synaptic contacts in rats subjected...... to an animal model for depression, where animals are exposed to a chronic stress protocol. Our hypothesis was that long term stress should reduce the number of axo-spinous synapses in the medial prefrontal cortex. Adult male rats were exposed to daily stress for 9 weeks and afterward we did a post mortem...

  12. Estimation of genetic parameters for reproductive traits in alpacas.

    Science.gov (United States)

    Cruz, A; Cervantes, I; Burgos, A; Morante, R; Gutiérrez, J P

    2015-12-01

    One of the main deficiencies affecting animal breeding programs in Peruvian alpacas is the low reproductive performance leading to low number of animals available to select from, decreasing strongly the selection intensity. Some reproductive traits could be improved by artificial selection, but very few information about genetic parameters exists for these traits in this specie. The aim of this study was to estimate genetic parameters for six reproductive traits in alpacas both in Suri (SU) and Huacaya (HU) ecotypes, as well as their genetic relationship with fiber and morphological traits. Dataset belonging to Pacomarca experimental farm collected between 2000 and 2014 was used. Number of records for age at first service (AFS), age at first calving (AFC), copulation time (CT), pregnancy diagnosis (PD), gestation length (GL), and calving interval (CI) were, respectively, 1704, 854, 19,770, 5874, 4290 and 934. Pedigree consisted of 7742 animals. Regarding reproductive traits, model of analysis included additive and residual random effects for all traits, and also permanent environmental effect for CT, PD, GL and CI traits, with color and year of recording as fixed effects for all the reproductive traits and also age at mating and sex of calf for GL trait. Estimated heritabilities, respectively for HU and SU were 0.19 and 0.09 for AFS, 0.45 and 0.59 for AFC, 0.04 and 0.05 for CT, 0.07 and 0.05 for PD, 0.12 and 0.20 for GL, and 0.14 and 0.09 for CI. Genetic correlations between them ranged from -0.96 to 0.70. No important genetic correlations were found between reproductive traits and fiber or morphological traits in HU. However, some moderate favorable genetic correlations were found between reproductive and either fiber and morphological traits in SU. According to estimated genetic correlations, some reproductive traits might be included as additional selection criteria in HU. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Hyperprolactinemia and male reproductive functions

    NARCIS (Netherlands)

    R.F.A. Weber (Robert)

    1983-01-01

    textabstractIn this thesis some effects of PRL on reproductive functions have been investigated PRL-secreting pituitary adenoma. animal model has been used: For in men with a comparison an In. rats hyperprolactinemia has been induced by sub-cutaneous inoculation of a PRL- and

  14. Reproductive effort in viscous populations

    NARCIS (Netherlands)

    Pen, Ido

    Here I study a kin selection model of reproductive effort, the allocation of resources to fecundity versus survival, in a patch-structured population. Breeding females remain in the same patch for life. Offspring have costly, partial long-distance dispersal and compete for breeding sites, which

  15. Law of large numbers for the SIR model with random vertex weights on Erdős-Rényi graph

    Science.gov (United States)

    Xue, Xiaofeng

    2017-11-01

    In this paper we are concerned with the SIR model with random vertex weights on Erdős-Rényi graph G(n , p) . The Erdős-Rényi graph G(n , p) is generated from the complete graph Cn with n vertices through independently deleting each edge with probability (1 - p) . We assign i. i. d. copies of a positive r. v. ρ on each vertex as the vertex weights. For the SIR model, each vertex is in one of the three states 'susceptible', 'infective' and 'removed'. An infective vertex infects a given susceptible neighbor at rate proportional to the production of the weights of these two vertices. An infective vertex becomes removed at a constant rate. A removed vertex will never be infected again. We assume that at t = 0 there is no removed vertex and the number of infective vertices follows a Bernoulli distribution B(n , θ) . Our main result is a law of large numbers of the model. We give two deterministic functions HS(ψt) ,HV(ψt) for t ≥ 0 and show that for any t ≥ 0, HS(ψt) is the limit proportion of susceptible vertices and HV(ψt) is the limit of the mean capability of an infective vertex to infect a given susceptible neighbor at moment t as n grows to infinity.

  16. Development of a Watershed-Scale Long-Term Hydrologic Impact Assessment Model with the Asymptotic Curve Number Regression Equation

    Directory of Open Access Journals (Sweden)

    Jichul Ryu

    2016-04-01

    Full Text Available In this study, 52 asymptotic Curve Number (CN regression equations were developed for combinations of representative land covers and hydrologic soil groups. In addition, to overcome the limitations of the original Long-term Hydrologic Impact Assessment (L-THIA model when it is applied to larger watersheds, a watershed-scale L-THIA Asymptotic CN (ACN regression equation model (watershed-scale L-THIA ACN model was developed by integrating the asymptotic CN regressions and various modules for direct runoff/baseflow/channel routing. The watershed-scale L-THIA ACN model was applied to four watersheds in South Korea to evaluate the accuracy of its streamflow prediction. The coefficient of determination (R2 and Nash–Sutcliffe Efficiency (NSE values for observed versus simulated streamflows over intervals of eight days were greater than 0.6 for all four of the watersheds. The watershed-scale L-THIA ACN model, including the asymptotic CN regression equation method, can simulate long-term streamflow sufficiently well with the ten parameters that have been added for the characterization of streamflow.

  17. Integer linear models with a polynomial number of variables and constraints for some classical combinatorial optimization problems

    Directory of Open Access Journals (Sweden)

    Nelson Maculan

    2003-01-01

    Full Text Available We present integer linear models with a polynomial number of variables and constraints for combinatorial optimization problems in graphs: optimum elementary cycles, optimum elementary paths and optimum tree problems.Apresentamos modelos lineares inteiros com um número polinomial de variáveis e restrições para problemas de otimização combinatória em grafos: ciclos elementares ótimos, caminhos elementares ótimos e problemas em árvores ótimas.

  18. Tomography of atomic number and density of materials using dual-energy imaging and the Alvarez and Macovski attenuation model

    International Nuclear Information System (INIS)

    Paziresh, M.; Kingston, A. M.; Latham, S. J.; Fullagar, W. K.; Myers, G. M.

    2016-01-01

    Dual-energy computed tomography and the Alvarez and Macovski [Phys. Med. Biol. 21, 733 (1976)] transmitted intensity (AMTI) model were used in this study to estimate the maps of density (ρ) and atomic number (Z) of mineralogical samples. In this method, the attenuation coefficients are represented [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)] in the form of the two most important interactions of X-rays with atoms that is, photoelectric absorption (PE) and Compton scattering (CS). This enables material discrimination as PE and CS are, respectively, dependent on the atomic number (Z) and density (ρ) of materials [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)]. Dual-energy imaging is able to identify sample materials even if the materials have similar attenuation coefficients at single-energy spectrum. We use the full model rather than applying one of several applied simplified forms [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976); Siddiqui et al., SPE Annual Technical Conference and Exhibition (Society of Petroleum Engineers, 2004); Derzhi, U.S. patent application 13/527,660 (2012); Heismann et al., J. Appl. Phys. 94, 2073–2079 (2003); Park and Kim, J. Korean Phys. Soc. 59, 2709 (2011); Abudurexiti et al., Radiol. Phys. Technol. 3, 127–135 (2010); and Kaewkhao et al., J. Quant. Spectrosc. Radiat. Transfer 109, 1260–1265 (2008)]. This paper describes the tomographic reconstruction of ρ and Z maps of mineralogical samples using the AMTI model. The full model requires precise knowledge of the X-ray energy spectra and calibration of PE and CS constants and exponents of atomic number and energy that were estimated based on fits to simulations and calibration measurements. The estimated ρ and Z images of the samples used in this paper yield average relative errors of 2.62% and 1.19% and maximum relative errors of 2.64% and 7.85%, respectively. Furthermore, we demonstrate that the method accounts for the beam hardening effect in density (

  19. Energy: reproduction

    International Nuclear Information System (INIS)

    Velasquez Penagos, J.G.

    1993-01-01

    The ovulatory activity in the livestock depends on the readiness of nutritious energy with relationship to its use for the nursing. During the early nursing the cup of increment in the production of milk exceeds to the consumption of food, the difference in the energy consumption of the diet with relationship to the energy used for production is a negative energy balance. During the first weeks of nursing this reaches their maximum and it diminishes slowly with the increment in the consumption of dry matter. This first metabolic sign is in an increment in the pulses of hormone luteinizant that acts as and stimulate for the ovary and that with a great readiness of insulin, it takes to the ovarian follicles to respond to the stimulus. The sub-alimentation seems to affect the hypothalamic function and ovarian. The return to the positive energy balance in cows highly producers can be accelerated by the consumption of protected fat. The functions of the lipids are to provide energy for normal maintenance and production, to serve as source of essential fatty acids and eat payee of liposoluble vitamins. The importance of the addition of vegetable fat is that this is not degraded in the rumen but rather it is digested in its entirety in abomasa and absorbed in intestine. The addition of a source of Ca to diets with fats promotes the formation of insoluble soaps achieving that the fat doesn't inhibit the fiber fermentation; the chloride of Ca to be of high solubility in water it is completely ionized in rumen and it is more efficient in the formation of insoluble soaps of Ca. The addition of fat in the diet bears increase in the production of N microbial, inhibition of methane formation, increase and change in population of bacteria and mushrooms. The efficiency of the fat is superior when sources of fatty acids of long chain are used, the employment of these, in its protected form, in a diet, stimulates the number of follicles and it increases its size. The linolic acid is

  20. Reproduction of World Ocean Circulation by the CORE-II Scenario with the Models INMOM and INMIO

    Science.gov (United States)

    Volodin, E. M.; Gusev, A. V.; Diansky, N. A.; Ibrayev, R. A.; Ushakov, K. V.

    2018-01-01

    The results of simulations performed by the CORE-II scenario using the two Russian OGCMs, INMOM and INMIO, are presented. The models use different coordinate systems in the basic set of primitive equations and different numerical techniques. Both models are used as oceanic components of the INM RAS coupled models. Simulations have shown that reproducing ocean circulation using both models agrees with observations and simulations by other models. In general, the INMOM slightly underestimates the meridional heat transport in the ocean when compared to the INMIO model and climatic estimations. However, the INMIO yields a higher bias in temperature than the INMOM.

  1. A simple testable model of baryon number violation: Baryogenesis, dark matter, neutron-antineutron oscillation and collider signals

    Science.gov (United States)

    Allahverdi, Rouzbeh; Dev, P. S. Bhupal; Dutta, Bhaskar

    2018-04-01

    We study a simple TeV-scale model of baryon number violation which explains the observed proximity of the dark matter and baryon abundances. The model has constraints arising from both low and high-energy processes, and in particular, predicts a sizable rate for the neutron-antineutron (n - n bar) oscillation at low energy and the monojet signal at the LHC. We find an interesting complementarity among the constraints arising from the observed baryon asymmetry, ratio of dark matter and baryon abundances, n - n bar oscillation lifetime and the LHC monojet signal. There are regions in the parameter space where the n - n bar oscillation lifetime is found to be more constraining than the LHC constraints, which illustrates the importance of the next-generation n - n bar oscillation experiments.

  2. The effect of the number of condensed phases modeled on aerosol behavior during an induced steam generator tube rupture sequence

    International Nuclear Information System (INIS)

    Bixler, N.E.; Schaperow, J.H.

    1998-06-01

    VICTORIA is a mechanistic computer code designed to analyze fission product behavior within a nuclear reactor coolant system (RCS) during a severe accident. It provides detailed predictions of the release of radioactive and nonradioactive materials from the reactor core and transport and deposition of these materials within the RCS. A recently completed independent peer review of VICTORIA, while confirming the overall adequacy of the code, recommended a number of modeling improvements. One of these recommendations, to model three rather than a single condensed phase, is the focus of the work reported here. The recommendation has been implemented as an option so that either a single or three condensed phases can be treated. Both options have been employed in the study of fission product behavior during an induced steam generator tube rupture sequence. Differences in deposition patterns and mechanisms predicted using these two options are discussed

  3. Analysis of the physical properties of trehalose-water-lithium iodide based on the bond strength coordination number fluctuation model

    International Nuclear Information System (INIS)

    Sahara; Jean L Ndeugueu; Masaru Aniya

    2010-01-01

    The temperature dependence of the viscosity of trehalose-water-lithium iodide system has been investigated by the mean of the Bond Strength Coordination Number Fluctuation (BSCNF) model. The result indicates that by increasing the trehalose content, maintaining the content of LiI constant, the fragility decreases due to the increase of the connectivity between the structural units. Our analysis suggests also that the fragility of the system is controlled by the amount of water in the composition. By increasing the water content, the total bond strength decreases and its fluctuation increases, resulting in the increase of the fragility. Based on the analysis of the obtained parameters of the BSCNF model, a physical interpretation of the VFT parameters reported in a previous study has been given. (author)

  4. Female reproductive decline is determined by remaining ovarian reserve and age.

    Directory of Open Access Journals (Sweden)

    Pawel Wilkosz

    Full Text Available The early decline and loss of female fertility in humans and other species represents an evolutionary paradox. Despite being born with a vast stock of oocytes, females encounter an exhaustion of ovarian reserve and sterility half way through their natural lives. Female reproductive ageing has been proposed to proceed as an ongoing decline in ovarian reserve, determined by remaining ovarian follicle number. However, despite extensive modelling, the respective contributions of intra-, inter-, and extra-ovarian signalling have not been fully characterised. It remains unclear whether reproductive ageing progresses simply as a pre-determined function of remaining ovarian follicles, or as an age-dependent process in humans. Here, we have analysed ovarian response to hormonal stimulation in women who have undergone surgical removal of a single ovary, in order to investigate the relative contributions of intra-, inter, and extra-ovarian signalling on reproductive ageing. Our data show that in unilaterally oophorectomised women, ovarian response to follicle stimulating hormone (FSH declines beyond levels predicted by a total ovarian follicle pool model of reproductive ageing. Maintenance of ovarian function later in reproductive life, despite the removal of half of the total ovarian reserve, suggests a role for an extra-ovarian age-dependent regulation of reproductive decline. This highlights the need for further work to identify signalling factors that communicate age-related signals between the soma and the germline.

  5. Physiologically-based pharmacokinetic modelling of immune, reproductive and carcinogenic effects from contaminant exposure in polar bears (Ursus maritimus) across the Arctic.

    Science.gov (United States)

    Dietz, Rune; Gustavson, Kim; Sonne, Christian; Desforges, Jean-Pierre; Rigét, Frank F; Pavlova, Viola; McKinney, Melissa A; Letcher, Robert J

    2015-07-01

    Polar bears (Ursus maritimus) consume large quantities of seal blubber and other high trophic marine mammals and consequently have some of the highest tissue concentrations of organohalogen contaminants (OHCs) among Arctic biota. In the present paper we carried out a risk quotient (RQ) evaluation on OHC-exposed polar bears harvested from 1999 to 2008 and from 11 circumpolar subpopulations spanning from Alaska to Svalbard in order to evaluate the risk of OHC-mediated reproductive effects (embryotoxicity, teratogenicity), immunotoxicity and carcinogenicity (genotoxicity). This RQ evaluation was based on the Critical Body Residue (CBR) concept and a Physiologically-Based Pharmacokinetic Modelling (PBPK) approach using OHC concentrations measured in polar bear adipose or liver tissue. The range of OHC concentrations within polar bear populations were as follows for adipose, sum polychlorinated biphenyls ∑PCBs (1797-10,537 ng/g lw), sum methylsulphone-PCB ∑MeSO2-PCBs (110-672 ng/g lw), sum chlordanes ∑CHLs (765-3477 ng/g lw), α-hexachlorocyclohexane α-HCH (8.5-91.3 ng/g lw), β-hexachlorocyclohexane β-HCH (65.5-542 ng/g lw), sum chlorbenzenes ∑ClBzs (145-304 ng/g lw), dichlorodiphenyltrichloroethane ∑DDTs (31.5-206 ng/g lw), dieldrin (69-249 ng/g lw), polybrominated diphenyl ethers ∑PBDEs (4.6-78.4 ng/g lw). For liver, the perfluorooctanesulfonic acid (PFOS) concentrations ranged from 231-2792 ng/g ww. The total additive RQ from all OHCs ranged from 4.3 in Alaska to 28.6 in East Greenland bears for effects on reproduction, immune health and carcinogenicity, highlighting the important result that the toxic effect threshold (i.e. RQ>1) was exceeded for all polar bear populations assessed. PCBs were the main contributors for all three effect categories, contributing from 70.6% to 94.3% of the total risk and a RQ between 3.8-22.5. ∑MeSO2-PCBs were the second highest effect contributor for reproductive and immunological effects (0.17polar bears. We therefore

  6. Dietary folate and reproductive success among women undergoing assisted reproduction.

    Science.gov (United States)

    Gaskins, Audrey J; Afeiche, Myriam C; Wright, Diane L; Toth, Thomas L; Williams, Paige L; Gillman, Matthew W; Hauser, Russ; Chavarro, Jorge E

    2014-10-01

    To prospectively evaluate the associations of folate with assisted reproductive technology outcomes within a population in the United States. This analysis included women (n=232) in a prospective cohort study at the Massachusetts General Hospital Fertility Center. Diet was assessed before assisted reproductive technology treatment using a validated food frequency questionnaire. Intermediate and clinical endpoints of assisted reproductive technology were abstracted from medical records. Generalized linear mixed models with random intercepts to account for multiple cycles per woman were used to evaluate the association of folate intake with assisted reproductive technology outcomes adjusting for calorie intake, age, body mass index, race, smoking status, infertility diagnosis, and protocol type. Among the 232 women (median age 35.2 years, median folate intake 1,778 micrograms/day), higher folate intake was associated with higher rates of implantation, clinical pregnancy, and live birth. The adjusted percentage (95% confidence interval [CI]) of initiated assisted reproductive technology cycles resulting in a live birth for women in increasing quartiles of folate intake were 30% (95% CI 21-42%), 47% (95% CI 35-59%), 42% (95% CI 30-35%) and 56% (95% CI 43-67%) (P for trend=0.01). Live birth rates were 20% (95% CI 8-31%) higher among women in the highest quartile of supplemental folate intake (more than 800 micrograms/day) than among women in the lowest quartile (less than 400 micrograms/day). Higher supplemental folate intake was associated with higher fertilization rates and lower cycle failure rates before embryo transfer (P for trend=0.03 and 0.02). Higher intake of supplemental folate was associated with higher live birth rates after assisted reproductive technology treatment. : II.

  7. African Journal of Reproductive Health - Vol 4, No 2 (2000)

    African Journals Online (AJOL)

    African Journal of Reproductive Health. ... African Journal of Reproductive Health - Vol 4, No 2 (2000). Journal Home > Archives > Vol 4, No 2 (2000). Log in or Register to get access to full text downloads. ... Editorial: Female Genital Mutilation: A Model for Research on Sexual and Reproductive Rights. OA Olatunbosun ...

  8. Bounds on the number of bound states in the transfer matrix spectrum for some weakly correlated lattice models

    Energy Technology Data Exchange (ETDEWEB)

    O' Carroll, Michael [Departamento de Matematica Aplicada e Estatistica, ICMC-USP, C.P. 668,13560-970 Sao Carlos, Sao Paulo (Brazil)

    2012-07-15

    We consider the interaction of particles in weakly correlated lattice quantum field theories. In the imaginary time functional integral formulation of these theories there is a relative coordinate lattice Schroedinger operator H which approximately describes the interaction of these particles. Scalar and vector spin, QCD and Gross-Neveu models are included in these theories. In the weakly correlated regime H=H{sub o}+W where H{sub o}=-{gamma}{Delta}{sub l}, 0 < {gamma} Much-Less-Than 1 and {Delta}{sub l} is the d-dimensional lattice Laplacian: {gamma}={beta}, the inverse temperature for spin systems and {gamma}={kappa}{sup 3} where {kappa} is the hopping parameter for QCD. W is a self-adjoint potential operator which may have non-local contributions but obeys the bound Double-Vertical-Line W(x, y) Double-Vertical-Line Less-Than-Or-Slanted-Equal-To cexp ( -a( Double-Vertical-Line x Double-Vertical-Line + Double-Vertical-Line y Double-Vertical-Line )), a large: exp-a={beta}/{beta}{sub o}{sup (1/2)}({kappa}/{kappa}{sub o}) for spin (QCD) models. H{sub o}, W, and H act in l{sub 2}(Z{sup d}), d Greater-Than-Or-Slanted-Equal-To 1. The spectrum of H below zero is known to be discrete and we obtain bounds on the number of states below zero. This number depends on the short range properties of W, i.e., the long range tail does not increase the number of states.

  9. Reduced Synapse and Axon Numbers in the Prefrontal Cortex of Rats Subjected to a Chronic Stress Model for Depression.

    Science.gov (United States)

    Csabai, Dávid; Wiborg, Ove; Czéh, Boldizsár

    2018-01-01

    Stressful experiences can induce structural changes in neurons of the limbic system. These cellular changes contribute to the development of stress-induced psychopathologies like depressive disorders. In the prefrontal cortex of chronically stressed animals, reduced dendritic length and spine loss have been reported. This loss of dendritic material should consequently result in synapse loss as well, because of the reduced dendritic surface. But so far, no one studied synapse numbers in the prefrontal cortex of chronically stressed animals. Here, we examined synaptic contacts in rats subjected to an animal model for depression, where animals are exposed to a chronic stress protocol. Our hypothesis was that long term stress should reduce the number of axo-spinous synapses in the medial prefrontal cortex. Adult male rats were exposed to daily stress for 9 weeks and afterward we did a post mortem quantitative electron microscopic analysis to quantify the number and morphology of synapses in the infralimbic cortex. We analyzed asymmetric (Type I) and symmetric (Type II) synapses in all cortical layers in control and stressed rats. We also quantified axon numbers and measured the volume of the infralimbic cortex. In our systematic unbiased analysis, we examined 21,000 axon terminals in total. We found the following numbers in the infralimbic cortex of control rats: 1.15 × 10 9 asymmetric synapses, 1.06 × 10 8 symmetric synapses and 1.00 × 10 8 myelinated axons. The density of asymmetric synapses was 5.5/μm 3 and the density of symmetric synapses was 0.5/μm 3 . Average synapse membrane length was 207 nm and the average axon terminal membrane length was 489 nm. Stress reduced the number of synapses and myelinated axons in the deeper cortical layers, while synapse membrane lengths were increased. These stress-induced ultrastructural changes indicate that neurons of the infralimbic cortex have reduced cortical network connectivity. Such reduced network connectivity is

  10. Reduced Synapse and Axon Numbers in the Prefrontal Cortex of Rats Subjected to a Chronic Stress Model for Depression

    Science.gov (United States)

    Csabai, Dávid; Wiborg, Ove; Czéh, Boldizsár

    2018-01-01

    Stressful experiences can induce structural changes in neurons of the limbic system. These cellular changes contribute to the development of stress-induced psychopathologies like depressive disorders. In the prefrontal cortex of chronically stressed animals, reduced dendritic length and spine loss have been reported. This loss of dendritic material should consequently result in synapse loss as well, because of the reduced dendritic surface. But so far, no one studied synapse numbers in the prefrontal cortex of chronically stressed animals. Here, we examined synaptic contacts in rats subjected to an animal model for depression, where animals are exposed to a chronic stress protocol. Our hypothesis was that long term stress should reduce the number of axo-spinous synapses in the medial prefrontal cortex. Adult male rats were exposed to daily stress for 9 weeks and afterward we did a post mortem quantitative electron microscopic analysis to quantify the number and morphology of synapses in the infralimbic cortex. We analyzed asymmetric (Type I) and symmetric (Type II) synapses in all cortical layers in control and stressed rats. We also quantified axon numbers and measured the volume of the infralimbic cortex. In our systematic unbiased analysis, we examined 21,000 axon terminals in total. We found the following numbers in the infralimbic cortex of control rats: 1.15 × 109 asymmetric synapses, 1.06 × 108 symmetric synapses and 1.00 × 108 myelinated axons. The density of asymmetric synapses was 5.5/μm3 and the density of symmetric synapses was 0.5/μm3. Average synapse membrane length was 207 nm and the average axon terminal membrane length was 489 nm. Stress reduced the number of synapses and myelinated axons in the deeper cortical layers, while synapse membrane lengths were increased. These stress-induced ultrastructural changes indicate that neurons of the infralimbic cortex have reduced cortical network connectivity. Such reduced network connectivity is likely

  11. Phenotypic consequences of copy number variation: insights from Smith-Magenis and Potocki-Lupski syndrome mouse models.

    Directory of Open Access Journals (Sweden)

    Guénola Ricard

    2010-11-01

    Full Text Available A large fraction of genome variation between individuals is comprised of submicroscopic copy number variation of genomic DNA segments. We assessed the relative contribution of structural changes and gene dosage alterations on phenotypic outcomes with mouse models of Smith-Magenis and Potocki-Lupski syndromes. We phenotyped mice with 1n (Deletion/+, 2n (+/+, 3n (Duplication/+, and balanced 2n compound heterozygous (Deletion/Duplication copies of the same region. Parallel to the observations made in humans, such variation in gene copy number was sufficient to generate phenotypic consequences: in a number of cases diametrically opposing phenotypes were associated with gain versus loss of gene content. Surprisingly, some neurobehavioral traits were not rescued by restoration of the normal gene copy number. Transcriptome profiling showed that a highly significant propensity of transcriptional changes map to the engineered interval in the five assessed tissues. A statistically significant overrepresentation of the genes mapping to the entire length of the engineered chromosome was also found in the top-ranked differentially expressed genes in the mice containing rearranged chromosomes, regardless of the nature of the rearrangement, an observation robust across different cell lineages of the central nervous system. Our data indicate that a structural change at a given position of the human genome may affect not only locus and adjacent gene expression but also "genome regulation." Furthermore, structural change can cause the same perturbation in particular pathways regardless of gene dosage. Thus, the presence of a genomic structural change, as well as gene dosage imbalance, contributes to the ultimate phenotype.

  12. Phenotypic consequences of copy number variation: insights from Smith-Magenis and Potocki-Lupski syndrome mouse models.

    Science.gov (United States)

    Ricard, Guénola; Molina, Jessica; Chrast, Jacqueline; Gu, Wenli; Gheldof, Nele; Pradervand, Sylvain; Schütz, Frédéric; Young, Juan I; Lupski, James R; Reymond, Alexandre; Walz, Katherina

    2010-11-23

    A large fraction of genome variation between individuals is comprised of submicroscopic copy number variation of genomic DNA segments. We assessed the relative contribution of structural changes and gene dosage alterations on phenotypic outcomes with mouse models of Smith-Magenis and Potocki-Lupski syndromes. We phenotyped mice with 1n (Deletion/+), 2n (+/+), 3n (Duplication/+), and balanced 2n compound heterozygous (Deletion/Duplication) copies of the same region. Parallel to the observations made in humans, such variation in gene copy number was sufficient to generate phenotypic consequences: in a number of cases diametrically opposing phenotypes were associated with gain versus loss of gene content. Surprisingly, some neurobehavioral traits were not rescued by restoration of the normal gene copy number. Transcriptome profiling showed that a highly significant propensity of transcriptional changes map to the engineered interval in the five assessed tissues. A statistically significant overrepresentation of the genes mapping to the entire length of the engineered chromosome was also found in the top-ranked differentially expressed genes in the mice containing rearranged chromosomes, regardless of the nature of the rearrangement, an observation robust across different cell lineages of the central nervous system. Our data indicate that a structural change at a given position of the human genome may affect not only locus and adjacent gene expression but also "genome regulation." Furthermore, structural change can cause the same perturbation in particular pathways regardless of gene dosage. Thus, the presence of a genomic structural change, as well as gene dosage imbalance, contributes to the ultimate phenotype.

  13. Female gonadal hormones and reproductive behaviors as key determinants of successful reproductive output of breeding whooping cranes (Grus americana)

    Science.gov (United States)

    Brown, Megan E; Converse, Sarah J.; Chandler, Jane N.; Shafer, Charles; Brown, Janine L; Keefer, Carol L; Songsasen, Nucharin

    2016-01-01

    Reproductive success of endangered whooping cranes (Grus americana) maintained ex situ is poor. As part of an effort to identify potential causes of poor reproductive success in a captive colony, we used non-invasive endocrine monitoring to assess gonadal and adrenal steroids of bird pairs with various reproductive outcomes and evaluated the relationships of hormones and behaviors to reproductive performance. Overall, reproductively successful (i.e., egg laying) females had significantly higher mean estrogen levels but lower mean progestogen concentrations than did unsuccessful females. Other hormones, including glucocorticoids and androgens, were not significantly different between successful and unsuccessful individuals. Observations of specific behaviors such as unison calling, marching, and the number of copulation attempts, along with overall time spent performing reproductive behaviors, were significantly higher in successful pairs. Our findings indicate that overall reproductive performance of whooping crane pairs is linked to female gonadal hormone excretion and reproductive behaviors, but not to altered adrenal hormone production.

  14. Female gonadal hormones and reproductive behaviors as key determinants of successful reproductive output of breeding whooping cranes (Grus americana).

    Science.gov (United States)

    Brown, Megan E; Converse, Sarah J; Chandler, Jane N; Shafer, Charles; Brown, Janine L; Keefer, Carol L; Songsasen, Nucharin

    2016-05-01

    Reproductive success of endangered whooping cranes (Grus americana) maintained ex situ is poor. As part of an effort to identify potential causes of poor reproductive success in a captive colony, we used non-invasive endocrine monitoring to assess gonadal and adrenal steroids of bird pairs with various reproductive outcomes and evaluated the relationships of hormones and behaviors to reproductive performance. Overall, reproductively successful (i.e., egg laying) females had significantly higher mean estrogen levels but lower mean progestogen concentrations than did unsuccessful females. Other hormones, including glucocorticoids and androgens, were not significantly different between successful and unsuccessful individuals. Observations of specific behaviors such as unison calling, marching, and the number of copulation attempts, along with overall time spent performing reproductive behaviors, were significantly higher in successful pairs. Our findings indicate that overall reproductive performance of whooping crane pairs is linked to female gonadal hormone excretion and reproductive behaviors, but not to altered adrenal hormone production. Published by Elsevier Inc.

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

    Science.gov (United States)

    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)

  16. Projection of Breast Cancer Burden due to Reproductive/Lifestyle Changes in Korean Women (2013-2030) Using an Age-Period-Cohort Model.

    Science.gov (United States)

    Lee, Joo Eun; Lee, Sang Ah; Kim, Tae Hyun; Park, Sohee; Choy, Yoon Soo; Ju, Yeong Jun; Park, Eun-Cheol

    2018-01-22

    The aim of this study was to estimate the burden of breast cancer that can be attributed to rapid lifestyle changes in South Korea in 2013-2030. An age-period-cohort model was used to estimate the incidence and mortality. The Global Burden of Disease Study Group method was used to calculate the years of life lost and years lived with disability in breast cancer patients using a nationwide cancer registry. The population attributable risks were calculated using meta-analyzed relative risk ratios and by assessing the prevalence of risk factors. Women's reproductive/lifestyle changes, including advanced maternal age at first childbirth (from 37 to 85 disability-adjusted life years [DALYs] per 100,000 person-years), total period of breastfeeding (from 22 to 46 DALYs per 100,000 person-years), obesity (from 37 to 61 DALYs per 100,000 person-years), alcohol consumption (from 19 to 39 DALYs per 100,000 person-years), oral contraceptive use (from 18 to 27 DALYs per 100,000 person-years), and hormone replacement therapy use (from 2 to 3 DALYs per 100,000 person-years) were identified as factors likely to increase the burden of breast cancer from 2013 to 2030. Approximately, 34.2% to 44.3% of the burden of breast cancer could be avoidable in 2030 with reduction in reproductive/lifestyle risk factors. The rapid changes of age structure and lifestyle in South Korea during the last decade are expected to strongly increase the breast cancer burden over time unless the risk factors can be effectively modified.

  17. Developing biological resource banks as a supporting tool for wildlife reproduction and conservation The Iberian lynx bank as a model for other endangered species.

    Science.gov (United States)

    Leon-Quinto, Trinidad; Simon, Miguel A; Cadenas, Rafael; Jones, Jonathan; Martinez-Hernandez, Francisco J; Moreno, Juan M; Vargas, Astrid; Martinez, Fernando; Soria, Bernat

    2009-06-01

    This work presents a Biological Resource Bank generated as a complementary supporting tool for the reproduction and the in situ and ex situ conservation of the Iberian lynx. In its design we prioritized the preservation of a maximum of the current genetic and biological diversity of the population, and the harmless collection of the samples. To provide future reproductive opportunities through any possible technique, we processed and cryopreserved germinal cells and tissues from dead animals, 7 males and 6 females, as well as somatic cells and tissues from 69 different individuals. This somatic cell reserve reflects a very important fraction of the population biodiversity which, furthermore, will allow the development of a wide variety of studies that can be easily extrapolated to the majority of the population. We have developed a new non-destructive method to isolate cells with stem-cell-like properties. If considered convenient in the future, and after proper research, such cells could permit therapeutic applications and perhaps be a good source to be used in somatic cell nuclear transfer. Samples of whole blood and its derivatives, hairs, urine and feces from many different individuals were also preserved. Proper storage of such samples is required to allow epidemiological studies to be performed for the testing of different etiological hypotheses or, in general, to develop any bio-sanitary study to improve conservation strategies within the natural habitat. This work describes the main aspects involved in the practical implementation of the Iberian lynx Biological Resource Bank, as a model that could be useful for the development of similar banks for other endangered species.

  18. A two-angle model of dynamic wetting in microscale capillaries under low capillary numbers with experiments.

    Science.gov (United States)

    Lei, Da; Lin, Mian; Li, Yun; Jiang, Wenbin

    2018-03-01

    An accurate model of the dynamic contact angle θ d is critical for the calculation of capillary force in applications like enhanced oil recovery, where the capillary number Ca ranges from 10 -10 to 10 -5 and the Bond number Bo is less than 10 -4 . The rate-dependence of the dynamic contact angle under such conditions remains blurred, and is the main target of this study. Featuring with pressure control and interface tracking, the innovative experimental system presented in this work achieves the desired ranges of Ca and Bo, and enables the direct optical measurement of dynamic contact angles in capillaries as tiny as 40 × 20 (width × height) μm and 80 × 20 μm. The advancing and receding processes of wetting and nonwetting liquids were tested. The dynamic contact angle was confirmed velocity-independent with 10 -9  < Ca < 10 -5 (contact line velocity V = 0.135-490 μm/s) and it can be described by a two-angle model with desirable accuracy. A modified two-angle model was developed and an empirical form was obtained from experiments. For different liquids contacting the same surface, the advancing angle θ adv approximately equals the static contact angle θ o . The receding angle θ rec was found to be a linear function of θ adv , in good agreement with our and other experiments from the literature. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Effort variation regularization in sound field reproduction

    DEFF Research Database (Denmark)

    Stefanakis, Nick; Jacobsen, Finn; Sarris, Ioannis

    2010-01-01

    In this paper, active control is used in order to reproduce a given sound field in an extended spatial region. A method is proposed which minimizes the reproduction error at a number of control positions with the reproduction sources holding a certain relation within their complex strengths......), and adaptive wave field synthesis (AWFS), both under free-field conditions and in reverberant rooms. It is shown that effort variation regularization overcomes the problems associated with small spaces and with a low ratio of direct to reverberant energy, improving thus the reproduction accuracy...... in the listening room....

  20. Molecular biology and reproduction.

    Science.gov (United States)

    McDonough, P G

    1999-03-01

    Modern molecular biology has provided unique insights into the fundamental understanding of reproductive disorders and the detection of microorganisms. The remarkable advances in DNA diagnostics have been expedited by the development of polymerase chain reaction (PCR) and the ability to isolate DNA and RNA from many different sources such as blood, saliva, hair roots, microscopic slides, paraffin-embedded tissue sections, clinical swabs, and even cancellous bone. These technical advances have been bolstered by the development of an increasing number of effective screening techniques to scan genomic DNA for unknown point mutations. The continued development of technology will ultimately result in automated DNA (desoxyribonucleic acid) diagnosis for the practicing clinician. The continuing expansion of information concerning the human genome will place an increasing emphasis on bioinformatics and the use of computer software for analyzing DNA sequences. With the automation of DNA diagnosis and the use of small samples (500 nanograms), the direct examination of the DNA of a patient, fetus, or microorganism will emerge as a definitive means of establishing the presence of the specific genetic change that causes disease. A knowledge of the precise pathology at the molecular level has and will provide important insights into the biochemical basis for many human diseases. A firm knowledge of the DNA alterations in disease and expression patterns of specific genes will provide for more directed therapeutic strategies. The refinement of vector technology and nuclear transplantion techniques will provide the opportunity for directed gene therapy to the early human embryo. This presentation is designed to acquaint the reader with current techniques of testing at the DNA level, prototype mutations in the reproductive sciences, new concepts in the molecular mechanisms of disease that affect reproduction, and therapeutic opportunities for the future. It is hoped that future

  1. Root-lesion nematodes suppress cabbage aphid population development by reducing aphid daily reproduction

    Directory of Open Access Journals (Sweden)

    W. H. Gera eHol

    2016-02-01

    Full Text Available Empirical studies have shown that belowground feeding herbivores can affect the performance of aboveground herbivores in different ways. Often the critical life-history parameters underlying the observed performance effects remain unexplored. In order to better understand the cause for the observed effects on aboveground herbivores, these ecological mechanisms must be better understood. In this study we combined empirical experiments with a modelling approach to analyse the effect of two root feeding endoparasitic nematodes with different feeding strategies on the population growth of the aboveground feeding specialist aphid Brevicoryne brassicae on Brassica nigra. The aim was to test whether emerging differences in life history characteristics (days until reproduction, daily reproduction would be sufficient to explain observed differences in aphid population development on plants with and without two species of nematodes. Aphid numbers were lower on plants with Pratylenchus penetrans in comparison to aphid numbers on plants with Meloidogyne spp. A dedicated experiment showed that aphid daily reproduction was lower on plants with P. penetrans (3.08 offspring per female per day in comparison to both uninfested plants and plants with Meloidogyne spp. (3.50 offspring per female per day. The species-specific reduction of aphid reproduction appeared independent of changes in amino acids, soluble sugars or the glucosinolate sinigrin in the phloem. An individual-based model revealed that relatively small differences in reproduction rate per female were sufficient to yield a similar difference in aphid populations as was found in the empirical experiments.

  2. Fragmenting Fatherhood: The Regulation of Reproductive Technologies

    OpenAIRE

    Sheldon, Sally

    2005-01-01

    Reproductive technologies offer the potential to break down parenthood into a number of constituent parts. These disruptive possibilities mean that the regulation of reproductive technologies holds important potential for study, providing a significant resource that has been little analysed with regard to fatherhood. This study attempts to remedy that lacuna through consideration of a range of recent developments in this area of English law. It reaches two general conclusions. First, while th...

  3. A multichain polymer slip-spring model with fluctuating number of entanglements for linear and nonlinear rheology

    Energy Technology Data Exchange (ETDEWEB)

    Ramírez-Hernández, Abelardo, E-mail: abelardo@anl.gov; Pablo, Juan J. de, E-mail: depablo@uchicago.edu [Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637 (United States); Peters, Brandon L.; Andreev, Marat; Schieber, Jay D., E-mail: schieber@iit.edu [Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637 (United States)

    2015-12-28

    A theoretically informed entangled polymer simulation approach is presented for description of the linear and non-linear rheology of entangled polymer melts. The approach relies on a many-chain representation and introduces the topological effects that arise from the non-crossability of molecules through effective fluctuating interactions, mediated by slip-springs, between neighboring pairs of macromolecules. The total number of slip-springs is not preserved but, instead, it is controlled through a chemical potential that determines the average molecular weight between entanglements. The behavior of the model is discussed in the context of a recent theory for description of homogeneous materials, and its relevance is established by comparing its predictions to experimental linear and non-linear rheology data for a series of well-characterized linear polyisoprene melts. The results are shown to be in quantitative agreement with experiment and suggest that the proposed formalism may also be used to describe the dynamics of inhomogeneous systems, such as composites and copolymers. Importantly, the fundamental connection made here between our many-chain model and the well-established, thermodynamically consistent single-chain mean-field models provides a path to systematic coarse-graining for prediction of polymer rheology in structurally homogeneous and heterogeneous materials.

  4. A multichain polymer slip-spring model with fluctuating number of entanglements for linear and nonlinear rheology

    Science.gov (United States)

    Ramírez-Hernández, Abelardo; Peters, Brandon L.; Andreev, Marat; Schieber, Jay D.; de Pablo, Juan J.

    2015-12-01

    A theoretically informed entangled polymer simulation approach is presented for description of the linear and non-linear rheology of entangled polymer melts. The approach relies on a many-chain representation and introduces the topological effects that arise from the non-crossability of molecules through effective fluctuating interactions, mediated by slip-springs, between neighboring pairs of macromolecules. The total number of slip-springs is not preserved but, instead, it is controlled through a chemical potential that determines the average molecular weight between entanglements. The behavior of the model is discussed in the context of a recent theory for description of homogeneous materials, and its relevance is established by comparing its predictions to experimental linear and non-linear rheology data for a series of well-characterized linear polyisoprene melts. The results are shown to be in quantitative agreement with experiment and suggest that the proposed formalism may also be used to describe the dynamics of inhomogeneous systems, such as composites and copolymers. Importantly, the fundamental connection made here between our many-chain model and the well-established, thermodynamically consistent single-chain mean-field models provides a path to systematic coarse-graining for prediction of polymer rheology in structurally homogeneous and heterogeneous materials.

  5. Estimation of expected number of accidents and workforce unavailability through Bayesian population variability analysis and Markov-based model

    International Nuclear Information System (INIS)

    Chagas Moura, Márcio das; Azevedo, Rafael Valença; Droguett, Enrique López; Chaves, Leandro Rego; Lins, Isis Didier

    2016-01-01

    Occupational accidents pose several negative consequences to employees, employers, environment and people surrounding the locale where the accident takes place. Some types of accidents correspond to low frequency-high consequence (long sick leaves) events, and then classical statistical approaches are ineffective in these cases because the available dataset is generally sparse and contain censored recordings. In this context, we propose a Bayesian population variability method for the estimation of the distributions of the rates of accident and recovery. Given these distributions, a Markov-based model will be used to estimate the uncertainty over the expected number of accidents and the work time loss. Thus, the use of Bayesian analysis along with the Markov approach aims at investigating future trends regarding occupational accidents in a workplace as well as enabling a better management of the labor force and prevention efforts. One application example is presented in order to validate the proposed approach; this case uses available data gathered from a hydropower company in Brazil. - Highlights: • This paper proposes a Bayesian method to estimate rates of accident and recovery. • The model requires simple data likely to be available in the company database. • These results show the proposed model is not too sensitive to the prior estimates.

  6. Increased reproductive success of women after prenatal undernutrition

    NARCIS (Netherlands)

    Painter, Rebecca C.; Westendorp, Rudi G. J.; de Rooij, Susanne R.; Osmond, Clive; Barker, David J. P.; Roseboom, Tessa J.

    2008-01-01

    BACKGROUND: Prenatal exposure to the Dutch famine is associated with an increased risk of chronic degenerative disease. We now investigate whether prenatal famine exposure affected reproductive success. METHODS: We assessed reproductive success (number of children, number of twins, age at delivery,

  7. The reproductive biology of intertidal klipfish (Perciformes: Clinidae ...

    African Journals Online (AJOL)

    Up to nine broods of eggs and embryos of different ages were found in the gonads at one time, although there was no relationship between the number of broods and fish size. The total number of reproductive elements (eggs and embryos), however, increased with fish mass in all species. Reproductive potential, calculated ...

  8. Fuzzy model to estimate the number of hospitalizations for asthma and pneumonia under the effects of air pollution.

    Science.gov (United States)

    Chaves, Luciano Eustáquio; Nascimento, Luiz Fernando Costa; Rizol, Paloma Maria Silva Rocha

    2017-06-22

    Predict the number of hospitalizations for asthma and pneumonia associated with exposure to air pollutants in the city of São José dos Campos, São Paulo State. This is a computational model using fuzzy logic based on Mamdani's inference method. For the fuzzification of the input variables of particulate matter, ozone, sulfur dioxide and apparent temperature, we considered two relevancy functions for each variable with the linguistic approach: good and bad. For the output variable number of hospitalizations for asthma and pneumonia, we considered five relevancy functions: very low, low, medium, high and very high. DATASUS was our source for the number of hospitalizations in the year 2007 and the result provided by the model was correlated with the actual data of hospitalization with lag from zero to two days. The accuracy of the model was estimated by the ROC curve for each pollutant and in those lags. In the year of 2007, 1,710 hospitalizations by pneumonia and asthma were recorded in São José dos Campos, State of São Paulo, with a daily average of 4.9 hospitalizations (SD = 2.9). The model output data showed positive and significant correlation (r = 0.38) with the actual data; the accuracies evaluated for the model were higher for sulfur dioxide in lag 0 and 2 and for particulate matter in lag 1. Fuzzy modeling proved accurate for the pollutant exposure effects and hospitalization for pneumonia and asthma approach. Prever o número de internações por asma e pneumonia associadas à exposição a poluentes do ar no município em São José dos Campos, estado de São Paulo. Trata-se de um modelo computacional que utiliza a lógica fuzzy baseado na técnica de inferência de Mamdani. Para a fuzzificação das variáveis de entrada material particulado, ozônio, dióxido de enxofre e temperatura aparente foram consideradas duas funções de pertinência para cada variável com abordagem linguísticas: bom e ruim. Para a variável de saída número interna

  9. Developing and Testing TernCOLONY 1.0: An Individual-based Model of Least Tern Reproduction

    Science.gov (United States)

    2013-06-01

    it produces for display in the web interface, are stored in a relational database. The database is implemented in PostgreSQL software...GIS) software. From GIS, the input is entered into the PostgreSQL database. The TernCOLONY model software reads its input from, and writes output to...Model  inputs in  PostgreSQL   database Input  prepar‐ ation Output in  database Model  runs •Graphical  display in  interface •Statistical  analysis

  10. Allocation to reproduction and relative reproductive costs in two species of dioecious Anacardiaceae with contrasting phenology.

    Science.gov (United States)

    Matsuyama, Shuhei; Sakimoto, Michinori

    2008-06-01

    The cost of reproduction in dioecious plants is often female-biased. However, several studies have reported no difference in costs of reproduction between the sexes. In this study, the relative reproductive allocation and costs at the shoot and whole-plant levels were examined in woody dioecious Rhus javanica and R. trichocarpa, in order to examine differences between types of phenophase (i.e. physiological stage of development). Male and female Rhus javanica and R. trichocarpa were sampled and the reproductive and vegetative allocation of the shoot were estimated by harvesting reproductive current-year shoots during flowering and fruiting. Measurements were made of the number of reproductive and total current-year shoots per whole plant, and of the basal area increment (BAI). The numbers of reproductive and total current-year shoots per 1-year-old shoot were counted in order to examine the costs in the following year at the shoot level. A female-biased annual reproductive allocation was found; however, the ratio of reproductive current-year shoots per tree and the BAI did not differ between sexes in Rhus javanica and R. trichocarpa. The percentage of 1-year-old shoots with at least one reproductive current-year shoot was significantly male-biased in R. trichocarpa, but not in R. javanica, indicating that there was a relative cost at the shoot level only in R. trichocarpa. The female-biased leaf mass per shoot, an indicator of compensation for costs, was only found in R. javanica. Relative reproductive costs at the shoot level were detected in Rhus trichocarpa, which has simultaneous leafing and flowering, but not in R. javanica, which has leafing followed by flowering. However, the costs for the whole-plant level were diminished in both species. The results suggest that the phenophase type may produce the different costs for R. javanica and R. trichocarpa through the development of a compensation mechanism.

  11. Baryon and lepton number violating effective operators in a non-universal extension of the standard model

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes-Martín, J. [Instituto de Física Corpuscular, CSIC - Universitat de València, Apt. Correus 22085, E-46071 València (Spain)

    2016-01-22

    It is well known that non-abelian Yang-Mills theories present non-trivial minima of the action, the so-called instantons. In the context of electroweak theories these instanton solutions may induce violations of baryon and lepton number of the form ΔB = ΔL = n{sub f}, with n{sub f} being the number of families coupled to the gauge group. An interesting feature of these violations is that the flavor structure of the gauge couplings is inherited by the instanton transitions. This effect is generally neglected in the literature. We will show that the inclusion of flavor interactions in the instanton solutions may be interesting in certain theoretical frameworks and will provide an approach to include these effects. In particular we will perform this implementation in the non-universal SU (2){sub l} ⊗SU (2){sub h} ⊗U (1){sub Y} model that singularizes the third family. Within this framework, we will use the instanton transitions to set a bound on the SU (2){sub h} gauge coupling.

  12. Maillard reaction products from highly heated food prevent mast cell number increase and inflammation in a mouse model of colitis.

    Science.gov (United States)

    Al Amir, Issam; Dubayle, David; Héron, Anne; Delayre-Orthez, Carine; Anton, Pauline M

    2017-12-01

    Links between food and inflammatory bowel diseases (IBDs) are often suggested, but the role of food processing has not been extensively studied. Heat treatment is known to cause the loss of nutrients and the appearance of neoformed compounds such as Maillard reaction products. Their involvement in gut inflammation is equivocal, as some may have proinflammatory effects, whereas other seem to be protective. As IBDs are associated with the recruitment of immune cells, including mast cells, we raised the hypothesis that dietary Maillard reaction products generated through heat treatment of food may limit the colitic response and its associated recruitment of mast cells. An experimental model of colitis was used in mice submitted to mildly and highly heated rodent food. Adult male mice were divided in 3 groups and received nonheated, mildly heated, or highly heated chow during 21 days. In the last week of the study, each group was split into 2 subgroups, submitted or not (controls) to dextran sulfate sodium (DSS) colitis. Weight variations, macroscopic lesions, colonic myeloperoxidase activity, and mucosal mast cell number were evaluated at the end of the experiment. Only highly heated chow significantly prevented DSS-induced weight loss, myeloperoxidase activity, and mast cell number increase in the colonic mucosa of DSS-colitic mice. We suggest that Maillard reaction products from highly heated food may limit the occurrence of inflammatory phases in IBD patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Evaluation and modelling of the size fractionated aerosol particle number concentration measurements nearby a major road in Helsinki ─ Part I: Modelling results within the LIPIKA project

    Directory of Open Access Journals (Sweden)

    M. Ketzel

    2007-08-01

    Full Text Available A field measurement campaign was conducted near a major road "Itäväylä" in an urban area in Helsinki in 17–20 February 2003. Aerosol measurements were conducted using a mobile laboratory "Sniffer" at various distances from the road, and at an urban background location. Measurements included particle size distribution in the size range of 7 nm–10 μm (aerodynamic diameter by the Electrical Low Pressure Impactor (ELPI and in the size range of 3–50 nm (mobility diameter by Scanning Mobility Particle Sizer (SMPS, total number concentration of particles larger than 3 nm detected by an ultrafine condensation particle counter (UCPC, temperature, relative humidity, wind speed and direction, driving route of the mobile laboratory, and traffic density on the studied road. In this study, we have compared measured concentration data with the predictions of the road network dispersion model CAR-FMI used in combination with an aerosol process model MONO32. For model comparison purposes, one of the cases was additionally computed using the aerosol process model UHMA, combined with the CAR-FMI model. The vehicular exhaust emissions, and atmospheric dispersion and transformation of fine and ultrafine particles was evaluated within the distance scale of 200 m (corresponding to a time scale of a couple of minutes. We computed the temporal evolution of the number concentrations, size distributions and chemical compositions of various particle size classes. The atmospheric dilution rate of particles is obtained from the roadside dispersion model CAR-FMI. Considering the evolution of total number concentration, dilution was shown to be the most important process. The influence of coagulation and condensation on the number concentrations of particle size modes was found to be negligible on this distance scale. Condensation was found to affect the evolution of particle diameter in the two smallest particle modes. The assumed value of the concentration of

  14. MODELING THE ANOMALY OF SURFACE NUMBER DENSITIES OF GALAXIES ON THE GALACTIC EXTINCTION MAP DUE TO THEIR FIR EMISSION CONTAMINATION

    Energy Technology Data Exchange (ETDEWEB)

    Kashiwagi, Toshiya; Suto, Yasushi; Taruya, Atsushi; Yahata, Kazuhiro [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan); Kayo, Issha [Department of Physics, Toho University, Funabashi, Chiba 274-8510 (Japan); Nishimichi, Takahiro, E-mail: kashiwagi@utap.phys.s.u-tokyo.ac.jp [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8568 (Japan)

    2015-02-01

    The most widely used Galactic extinction map is constructed assuming that the observed far-infrared (FIR) fluxes come entirely from Galactic dust. According to the earlier suggestion by Yahata et al., we consider how FIR emission of galaxies affects the SFD map. We first compute the surface number density of Sloan Digital Sky Survey (SDSS) DR7 galaxies as a function of the r-band extinction, A {sub r,} {sub SFD}. We confirm that the surface densities of those galaxies positively correlate with A {sub r,} {sub SFD} for A {sub r,} {sub SFD} < 0.1, as first discovered by Yahata et al. for SDSS DR4 galaxies. Next we construct an analytical model to compute the surface density of galaxies, taking into account the contamination of their FIR emission. We adopt a log-normal probability distribution for the ratio of 100 μm and r-band luminosities of each galaxy, y ≡ (νL){sub 100} {sub μm}/(νL) {sub r}. Then we search for the mean and rms values of y that fit the observed anomaly, using the analytical model. The required values to reproduce the anomaly are roughly consistent with those measured from the stacking analysis of SDSS galaxies. Due to the limitation of our statistical modeling, we are not yet able to remove the FIR contamination of galaxies from the extinction map. Nevertheless, the agreement with the model prediction suggests that the FIR emission of galaxies is mainly responsible for the observed anomaly. Whereas the corresponding systematic error in the Galactic extinction map is 0.1-1 mmag, it is directly correlated with galaxy clustering and thus needs to be carefully examined in precision cosmology.

  15. Sagan numbers

    OpenAIRE

    Mendonça, J. Ricardo G.

    2012-01-01

    We define a new class of numbers based on the first occurrence of certain patterns of zeros and ones in the expansion of irracional numbers in a given basis and call them Sagan numbers, since they were first mentioned, in a special case, by the North-american astronomer Carl E. Sagan in his science-fiction novel "Contact." Sagan numbers hold connections with a wealth of mathematical ideas. We describe some properties of the newly defined numbers and indicate directions for further amusement.

  16. Fibonacci numbers

    CERN Document Server

    Vorob'ev, Nikolai Nikolaevich

    2011-01-01

    Fibonacci numbers date back to an 800-year-old problem concerning the number of offspring born in a single year to a pair of rabbits. This book offers the solution and explores the occurrence of Fibonacci numbers in number theory, continued fractions, and geometry. A discussion of the ""golden section"" rectangle, in which the lengths of the sides can be expressed as a ration of two successive Fibonacci numbers, draws upon attempts by ancient and medieval thinkers to base aesthetic and philosophical principles on the beauty of these figures. Recreational readers as well as students and teacher

  17. Reproductive strategies in snakes.

    OpenAIRE

    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 thermoreg...

  18. Number names and number understanding

    DEFF Research Database (Denmark)

    Ejersbo, Lisser Rye; Misfeldt, Morten

    2014-01-01

    through using mathematical names for the numbers such as one-ten-one for 11 and five-ten-six for 56. The project combines the renaming of numbers with supporting the teaching with t