Degree Of Selfing Research Articles

The role of ‘shared representations’ in social perception and empathy: An fMRI study

Evidence suggests that we use the same mechanisms for both producing and perceiving actions. Such ‘shared representations’ may also underlie social perception and empathy. However, this idea raises some important and as yet unresolved questions: (i) how do we distinguish other-orientated empathic responses from a self-orientated reactions such as personal distress and (ii) what are the neural substrates underpinning these processes? We employed event-related functional magnetic resonance imaging (fMRI) to explore whether ‘shared representations’ were recruited to decode dynamic social stimuli in 12 healthy volunteers. We used an adapted version of the Profile of Non-Verbal Sensitivity (Rosenthal, H., Hall, J.A., DiMatteo, M.R., Rogers, P.L., Archer, D., (1979). Sensitivity to nonverbal communication: the PONS test. The Johns Hopkins University Press, Baltimore) which taps social perception using brief silent video clips. Participants chose one of two words that best described the state conveyed by the actor, or in the control condition using the same clips, the word describing which parts of the body were visible (non-social labelling). Off-line self-report measures of empathy and personal distress engendered by thoughts about others, were also given along with an experimentally-derived index of the degree of self–other overlap during social perception. Brain activation specific to the main experimental condition was found in the inferior frontal gyrus (BA44) and premotor areas (BA6) consistent with the use of ‘shared representations’. Somatosensory areas such as the insula and supramarginal gyrus (BA40) were also activated suggesting that participants constructed a qualitative representation of the target state. Activity in the rostral anterior cingulate was associated with self-reports of personal distress and increased blood flow to the anterior cingulate (BA24) and inferior parietal cortex (BA40) was related to self–other overlap.

Selfing and inbreeding depression in seeds and seedlings of Neobalanocarpus heimii (Dipterocarpaceae)

We evaluated the degree of selfing and inbreeding depression at the seed and seedling stages of a threatened tropical canopy tree, Neobalanocarpus heimii, using microsatellite markers. Selection resulted in an overall decrease in the level of surviving selfed progeny from seeds to established seedlings, indicating inbreeding depression during seedling establishment. Mean seed mass of selfed progeny was lower than that of outcrossed progeny. Since the smaller seeds suffered a fitness disadvantage at germination in N. heimii, the reduced seed mass of selfed progeny would be one of the determinants of the observed inbreeding depression during seedling establishment. High selfing rates in some mother trees could be attributed to low local densities of reproductive individuals, thus maintenance of a sufficiently high density of mature N. heimii should facilitate regeneration and conservation of the species.

Processes of Recovery in Serious Mental Illness: Findings from a Multinational Study

ABSTRACT As part of a growing literature describing processes of recovery in psychotic disorders, this report presents findings of an intensive, international study. Open-ended qualitivite interviews were conducted in Italy, Norway, Sweden, and the United States with a total of twelve individuals who have experience of recovery in psychosis. All interviews were translated into English and transcribed. Investigators from each of these countries collaborated in analyzing the interviews and identifying common elements across the twelve narratives. Themes were identified in each of the following areas: 1) how the individual deals with his or her difficulties; 2) the role of material resources; 3) the various roles of formal and informal health systems; 4) the roles, and absence, of significant others; and 5) the roles of social and cultural factors. Salient themes included the person's determination to get better, establishing a degree of self–control, and struggling to achieve a normal life; the need for mat...

Breeding system and graft compatibility in Prosopis cineraria and Prosopis juliflora

The floral buds began to appear in mid March and started to open from first week of April in Prosopis cineraria. From mid April to mid May was the peak period of flowering. In P. juliflora, on the other hand, floral buds began to appear in early March and began to open by end of march. Pollen viability of fresh pollen was more than 85 per cent in both the species. Observations on breeding behavior found predominance of cross fertilization; the degree of selfing was far below 1 per cent (in muslin cloth bags). Reciprocal crosses showed poor success, ranging fro 0.08 per cent in P. juliflora as female parent to 0.62 per cent on P. cineraria as seed parent. Reciprocal grafting using P. juliflora as scion showed cleft method somewhat better (16.1% successful), while T-budding was the poorest. However, grafts failed to sprout using P. cineraria as scion.

Self-Focused Attention and the Self-Regulation of Attention: Implications for Personality and Pathology

The ability to shift attention away from the self may increase self–conscious individuals' vulnerability to negative affective states. Participants' ability to shift their attention away from themselves was assessed by how quickly they could shift attention to an external stimulus when thinking about themselves relative to their reaction time when thinking about someone else. This measure of attentional flexibility was not related to the degree of self–focus. Consistent with previous research, individuals high in private self–focused attention were more dysphoric. Being low in attentional flexibility magnified the effects of private self–focused attention. Participants high in private self–awareness who could not stop thinking about themselves experienced more dysphoria and generalized anxiety than those lower in self–consciousness or those who could better regulate attention. A similar effect was found for public self–awareness and social anxiety.

Effects of Animal Pollination on Pollen Dispersal, Selfing, and Effective Population Size of Tropical Trees: A Simulation Study

ABSTRACTAnimals, especially insects, are principal pollen vectors of tropical trees and have behavior patterns that affect gene dispersal. Here, we explore complex pollination systems using a new simulation model Eco‐Gene and considering, among other factors, flowering synchrony, spatial distribution of trees, degree of selfing, population densities, pollinator flight distances, pollen deposition, and pollinator response to floral display size. Sensitivity analyses using two contrasting tree data sets (Jacaranda copaia and Dipteryx odorata) determined the importance of each parameter on three response variables: the proportion of seeds from self‐pollination, effective population size, and pollen dispersal. Spatial considerations and attractiveness of floral displays were prominent features determining the population genetic result of pollinators, and some biological implications of the results are discussed.RESUMENAnimales, insectos en particular, son los vectores principals del polen de los arboles tropicales y como consecuencia su comportamiento afecta dispersión genética. Aquí se examina sistemas de la polinización en su totalidad, aplicando un nuevo programa de simulacro Eco‐Gene, que se toma en cuenta, entre otros factores, sincronicidad de floración, distribución de arboles, grado de auto‐fecundación, densidad poblacional, distancia de vuelo, polen deposición, respuesta comportamiental de polenizadores al tamaño del anuncio floral. Sensitivity análisis con datos contrastantes de dos arboles (Jacaranda copaia y Dipteryx odorata) evaluó la importancia de cada parametro y su resultado respeto a: la proporcion de semillas producidas por autofecundación, tamano poblacional efectivo, y distancia de dispersión del polen. Las cualidades espaciales de poblaciones, y la atractividad del anuncio floral determinaban fuertemente las consecuencias de polinizacion, y se considera implicaciones biológicas y genéticas de los resultados.

Causal relationships between inbreeding, seed characteristics and plant performance in leek (Allium porrum L.)

Leek (Allium porrum L.) is an important outdoor vegetable in West Europe, where it is cultivated on about 30,000 ha. Most commercial cultivars of leek are open pollinated. One of the major problems with the crop is poor uniformity. Leek is an outbreeding species with up to 20% self-fertilisation. Much of the variation of open pollinated cultivars is explained by the strong sensitivity to in breeding depression after selfing. In this study we attempt to analyse in a systematic way the relationship between degree of selfing and agricultural performance in leek. The results obtained confirm a negative correlation between selfing and somea gricultural aspects important for vigour such as seedling emergence, plant growth and plant fresh yield. Also negative correlations between degree of selfing and seed individual weight and between selfing and seed individual size were found. The negative relationship between inbreeding and plant weight at harvest is further confirmed in an experiment in which the origin (cross-pollination orself-pollination) of each individual offspring plant analysed was determined using AFLP-markers. Finally, the correlation between chlorophyll deficiency genes and the loss of vigour that follows selfing was investigated. The results obtained demonstrate a significant decrease of pigment content in two generations of selfing.

Aerosol Retrievals from the Multiyear Multisatellite AVHRR Pathfinder Atmosphere (PATMOS) Dataset for Correcting Remotely Sensed Sea Surface Temperatures

Eight-year (1990–98), two-satellite (NOAA-11 and -14), global daily ∼(110 km)2 gridded observations from the Advanced Very High Resolution Radiometer (AVHRR) Pathfinder Atmosphere (PATMOS) dataset have been previously merged with the Pathfinder Matchup Database (PFMDB) and used to develop the Phase I aerosol correction for sea surface temperatures (SSTs) from AVHRR. In this study, this unique PATMOS–BUOY matchup dataset (N = 105 831) is used to derive and quality control an advanced set of aerosol parameters to be used in the Phase II algorithm: aerosol optical depths in channels 1 (λ1 = 0.63 μm) and 2 (λ2 = 0.83 μm), τ1 and τ2, and Ångström exponent α = −ln(τ1/τ2)/ln(λ1/λ2). Inaccurate retrievals at low sun and outliers are removed from the data. PATMOS global, multiyear, multisatellite aerosol properties, derived from cloud-free portions of the (110 km)2 grid, resemble many features previously observed in the space–time-restricted, (8 km)2 resolution Aerosol Observation (AEROBS) operational retrievals, in spite of a different spatial resolution, cloud screening, and sampling. Histograms of τ and α are accurately fit by lognormal and normal probability density functions, respectively. Retrievals of τ2 are consistent with τ1 at low τ, but reveal high multiplicative bias, resulting in a low additive bias in α. Random errors in α are inversely proportional to τ, with signal-to-noise ratio well approximated as η = τ1/τ1o. Parameter τ1o (τ threshold at which signal in α compares to its noise, i.e., η = 1) in PATMOS data (τ1o ∼ 0.11 ± 0.01) is less than in AEROBS (τ1o ∼ 0.18 ± 0.02), since noise is suppressed by the additional spatial averaging in PATMOS. The effect of cloud screening and sampling is also quantified. PATMOS τ1, τ2, and α reveal a strong trend against cloud amount, which is not fully understood, and some residual artificial time/angle trends, due to undercorrected calibration errors and remaining algorithm problems. But overall, they show a high degree of self- and interconsistency, thus providing a superior set of aerosol predictors to be used in the Phase II SST aerosol correction algorithm.

Differentiation in the status of self-incompatibility among Calibrachoa species (Solanaceae).

The overall status of self-incompatibility, as assessed by the rate of capsule-set after self-pollination, was investigated in the genus Calibrachoa (Solanaceae). Thirty-two species were surveyed using a total of 655 individuals collected in 102 different native populations in Argentina, Brazil, Mexico, and Uruguay. The rate of capsule-set in 278 voucher specimens collected from the same native habitats was also measured to obtain additional information to assess the degree of self-(in)compatibility. Only one species, Calibrachoa parviflora, was self-compatible (SC, autogamous) and the other 31 species were found to be self-incompatible (SI). A mixed population (SI and SC individuals in the same population) was not found. The differentiation of C. parviflora as an autogamous species is associated with a successful occupation of different (riparian) habitats within a larger range of geographic distribution compared to the rest of the species in the principally SI genus of Calibrachoa.

Gametocyte sex ratio of a malaria parasite: experimental test of heritability.

The gametocyte sex ratio of Plasmodium mexicanum, a malaria parasite of western fence lizards, was studied in a modified garden experiment. Each of 6 naturally infected lizards was used to initiate 20 replicate-infections in naive western fence lizards. A significant donor effect was observed for the sex ratios of recipient infections at their maximal parasitemia, and this effect was associated with the sex ratio of the donor infection. In 20 infections in which sex ratio was followed during the course of the infection, 9 revealed constant sex ratios and 11 showed an increase in proportion of males over time. Recipient sex ratio was correlated with another life-history trait, a composite of rate of asexual replication and peak parasitemia, such that higher Rate-Peak scores were associated with infections with less female-biased sex ratios. These results are placed into the context of sex ratio theory that concludes that the degree of selfing of parasite genotypes (number of parasite clones) within the vector will influence the evolution of gametocyte sex ratio. The theory predicts that the sex ratio should be under some genetic control and thus be heritable as observed in the experiment. Clonal diversity should also influence the life-history trait, Rate-Peak, which was found to be correlated with sex ratio.

Aerosol Retrievals from Individual AVHRR Channels. Part II: Quality Control, Probability Distribution Functions, Information Content, and Consistency Checks of Retrievals

This second part of a two-part study evaluates retrievals of aerosol optical depths, τ1 and τ2, in Advanced Very High Resolution Radiometer (AVHRR) channels 1 and 2 centered at λ1 = 0.63 and λ2 = 0.83 μm, and an effective Ångström exponent, α, derived therefrom as α = −ln(τ1/τ2)/ln(λ1/λ2). The retrievals are made with the Second Simulation of the Satellite Signal in the Solar Spectrum (6S) radiative transfer model from four NOAA-14 AVHRR datasets, collected between February 1998 and May 1999 in the latitudinal belt of 5°–25°S. A series of quality control (QC) checks applied to the retrievals to identify outliers are described. These remove a total of ∼1% of points, which presumably originate from channel misregistration, residual cloud in AVHRR cloud-screened pixels, and substantial deviations from the assumptions used in the retrieval model (e.g., bright coastal and high altitude inland waters). First, from examining histograms of the derived parameters it is found that τ and α are accurately fit by lognormal and normal probability distribution functions (PDFs), respectively. Second, the scattergrams τ1 versus τ2 are analyzed to see if they form a coherent pattern. They do indeed converge at the origin, as expected, but frequently are outside of the expected domain in τ1–τ2 space, defined by two straight lines corresponding to α = 0 and α = 2. This results in a low bias in α, which tends to fill in an interval of α ∈ [−1, 1] rather than α ∈ [0, 2]. Third, scattergrams of α versus τ are used to empirically confirm a previously drawn theoretical conclusion that errors in α are inversely proportional to τ. More in-depth quantitative analyses suggest that the AVHRR-derived Ångström exponent becomes progressively more meaningful when τ > 0.2. Geographical trends are studied to demonstrate that the selected ocean area is reasonably uniform to justify application of consistency checks to reveal angular trends in the retrievals. These checks show that in most cases, the artifacts in the retrieved τ and α are statistically insignificant. On average, the analyses suggest that the retrieved τ1, τ2, and α show a high degree of self- and interconsistency, with the exception of a troublesome May 1999 dataset. The most prominent problem noticed so far is the inconsistency between τ1 and τ2, persistent from one dataset to another, which calls for fine-tuning some (not aerosol-model related) elements of the retrieval algorithm. These adjustments will be discussed elsewhere.

The extent of linkage disequilibrium in Arabidopsis thaliana.

Linkage disequilibrium (LD), the nonrandom occurrence of alleles in haplotypes, has long been of interest to population geneticists. Recently, the rapidly increasing availability of genomic polymorphism data has fueled interest in LD as a tool for fine-scale mapping, in particular for human disease loci. The chromosomal extent of LD is crucial in this context, because it determines how dense a map must be for associations to be detected and, conversely, limits how finely loci may be mapped. Arabidopsis thaliana is expected to harbor unusually extensive LD because of its high degree of selfing. Several polymorphism studies have found very strong LD within individual loci, but also evidence of some recombination. Here we investigate the pattern of LD on a genomic scale and show that in global samples, LD decays within approximately 1 cM, or 250 kb. We also show that LD in local populations may be much stronger than that of global populations, presumably as a result of founder events. The combination of a relatively high level of polymorphism and extensive haplotype structure bodes well for developing a genome-wide LD map in A. thaliana.

Physical Basis, Premises, and Self-Consistency Checks of Aerosol Retrievals from TRMM VIRS

This paper outlines the processing stream for aerosol retrievals over oceans from the visible and infrared scanner [VIRS; a five-channel radiometer similar to the National Oceanic and Atmospheric Administration’s Advanced Very High Resolution Radiometer (AVHRR)] aboard the Tropical Rainfall Measuring Mission (TRMM) satellite, launched in November 1997. Emphasis is on 1) the applying the previously developed AVHRR second-generation aerosol retrieval algorithm to VIRS data to derive an aerosol parameter, indicative of particle size; 2) removing the unwanted “thermal leak” signal in the 1.61-μm channel; 3) giving examples of the first aerosol retrievals from space at this wavelength; and 4) assessing the accuracy of the retrievals with theoretical error analyses and empirical self- and interconsistency checks. Aerosol optical depths τA1 and τA2 are retrieved from reflected solar radiances in VIRS channels 1 and 2 centered at wavelengths λ1 = 0.63 and λ2 = 1.61 μm, using two independent lookup tables. When τA1 and τA2 exceed a certain threshold τAmin an effective Ångström exponent α related to particle size is derived as α = −ln(τA1/τA2)/ln(λ1/λ2). Channel 2 is contaminated by a thermal leak, originating from a secondary spectral response peak centered at ∼5.2 μm. If uncorrected, it leads to errors in τA2 of 100% or more. To minimize this error, nighttime VIRS “dark” radiances in channel 2 have been related empirically to radiances in channels 4 and 5 (10.8 and 12 μm, respectively), and view angle through regression analyses. The reflected component in channel-2 daytime measurements is estimated by subtracting the empirically derived thermal component from the total signal and is used in the retrieval of τA2. Theoretical error analysis is used to identify the limitations of the VIRS retrieval algorithm, whereas actual retrievals are preliminarily evaluated using a set of specially developed empirical checks. The checks show, on average, a high degree of self- and interconsistency but also identify problems with the retrievals, the most noteworthy being trends in retrieved optical depths with viewing and illumination angles. These problems will be tackled in the next-generation aerosol retrieval algorithm.

The Audience in Media Activism

The Audience in Media Activism

No evidence for killer sperm or other selective interactions between human spermatozoa in ejaculates of different males in vitro.

This study examines one of the possible mechanisms of sperm competition, i.e. the kamikaze sperm hypothesis. This hypothesis states that sperm from different males interact to incapacitate each other in a variety of ways. We used ejaculates from human donors to compare mixes of semen in vitro from the same or different males. We measured the following parameters: (i) the degree of sperm aggregation, velocity and proportion of morphologically normal sperm after 1 and 3 h incubation in undiluted semen samples, (ii) the proportion of viable sperm plus the same parameters as in (i) in 'swim-up' sperm suspensions after 1 and 3 h incubation, (iii) the degree of self and non-self sperm aggregation using fluorescent dyes to distinguish the sperm of different males, and (iv) the extent of sperm capacitation and acrosome-reacted sperm in mixtures of sperm from the same and different males. We observed very few significant changes in sperm aggregation or performance in mixtures of sperm from different males compared with mixtures from the same male and none that were consistent with previously reported findings. The incapacitation of rival sperm therefore seems an unlikely mechanism of sperm competition in humans.

Variation in the sexual behaviour of Achnanthes longipes (Bacillariophyta). II. Inbred monoecious lineages

This paper continues a series of studies of the allogamous raphid diatom Achnanthes longipes, which has a complex reproductive system combining unisexual, bisexual and monoecious behaviour. Following earlier work on the effects of inbreeding in the progeny of crosses between two unisexual clones, we studied the progeny of clones that are capable of a high degree of selfing in monoclonal culture (‘monoecious clones’). Three generations of selfed progeny were examined. In addition, we investigated the F1 generation obtained after crossing two different monoecious clones. Monoecious clones produced monoecious or, more rarely, bisexual progeny, but did not give rise to unisexual progeny. As in inbred lineages made by crossing closely related unisexual clones, inbreeding in monoecious lineages leads to a reduction in the number of gametes formed by the gametangia, from two to one. Inbred clones exhibit marked inbreeding depression and only three inbred generations were possible in monoecious lineages. In the third, final inbred generation, monoecious sexual reproduction was initiated in monoclonal cultures but gametes rarely fused and none of the auxospores and initial cells that were formed were viable ; this also occurred when the inbred clones were crossed with any of the other clones available. The significance of inbreeding and other aspects of the breeding system in A. longipes is discussed.

Variation in the sexual behaviour of Achnanthes longipes (Bacillariophyta). II. Inbred monoecious lineages

This paper continues a series of studies of the allogamous raphid diatom Achnanthes longipes, which has a complex reproductive system combining unisexual, bisexual and monoecious behaviour. Following earlier work on the effects of inbreeding in the progeny of crosses between two unisexual clones, we studied the progeny of clones that are capable of a high degree of selfing in monoclonal culture (‘monoecious clones’). Three generations of selfed progeny were examined. In addition, we investigated the F1 generation obtained after crossing two different monoecious clones. Monoecious clones produced monoecious or, more rarely, bisexual progeny, but did not give rise to unisexual progeny. As in inbred lineages made by crossing closely related unisexual clones, inbreeding in monoecious lineages leads to a reduction in the number of gametes formed by the gametangia, from two to one. Inbred clones exhibit marked inbreeding depression and only three inbred generations were possible in monoecious lineages. In the third, final inbred generation, monoecious sexual reproduction was initiated in monoclonal cultures but gametes rarely fused and none of the auxospores and initial cells that were formed were viable ; this also occurred when the inbred clones were crossed with any of the other clones available. The significance of inbreeding and other aspects of the breeding system in A. longipes is discussed.

Stabilization of Mixed-Mating Systems by Differences in the Magnitude of Inbreeding Depression for Male and Female Fitness Components

Stabilization of Mixed-Mating Systems by Differences in the Magnitude of Inbreeding Depression for Male and Female Fitness Components

Termination of Nutrition and Hydration in the Minimally Conscious State: Contrasting Clinical Views

Many ethical issues arise when treating individuals in the minimally conscious state. In large part, this is attributable to the fact that these individuals have severe physical and cognitive impairment yet retain some degree of self- and environmental awareness. This article presents a point-counterpoint discussion regarding termination of treatment in a hypothetical case involving the minimally conscious state. The opinions presented reflect the personal perspectives of a general neurologist and a neurorehabilitation specialist.

Assessing population genetic structure and variability with RAPD data: Application to Vaccinium macrocarpon (American Cranberry)

AbstractA method for estimating and comparing population genetic variation using random amplified polymorphic DNA (RAPD) profiling is presented. An analysis of molecular variance (AMOVA) is extended to accomodate phenotypic molecular data in diploid populations in Hardy‐Weinberg equilibrium or with an assumed degree of selfing. We present a two step strategy: 1) Estimate RAPD site frequencies without preliminary assumptions on the unknown population structure, then perform significance testing for population substructuring. 2) If population structure is evident from the first step, use this data to calculate better estimates for RAPD site frequencies and sub‐population variance components. A nonparametric test for the homogeneity of molecular variance (HOMOVA) is also presented. This test was designed to statistically test for differences in intrapopulational molecular variances (heteroscedasticity among populations). These theoretical developments are applied to a RAPD data set in Vaccinium macrocarpon (American cranberry) using small sample sizes, where a gradient of molecular diversity is found between central and marginal populations. The AMOVA and HOMOVA methods provide flexible population analysis tools when using data from RAPD or other DNA methods that provide many polymorphic markers with or without direct allelic data.