scholarly journals Individual based genetic analyses support asexual hydrochory dispersal in Zostera noltei

2018 ◽  
Author(s):  
Buga Berković ◽  
Nelson Coelho ◽  
Licínia Gouveia ◽  
Ester A. Serrão ◽  
Filipe Alberto
Keyword(s):  
Clonal Plants ◽  
Genetic Identification ◽  
Spatially Explicit ◽  
Causal Mechanism ◽  
Zostera Noltei ◽  
Two Samples ◽  
Local Patch ◽  
Southern Portugal ◽  
Important Means ◽  
Large Clone

AbstractDispersal beyond the local patch in clonal plants was typically thought to result from sexual reproduction via seed dispersal. However, evidence for the separation, transport by water, and re-establishment of asexual propagules (asexual hydrochory) is mounting suggesting other important means of dispersal in aquatic plants. Using an unprecedented sampling size and microsatellite genetic identification, we describe the distribution of seagrass clones along tens of km within a coastal lagoon in Southern Portugal. Our spatially explicit individual-based sampling design covered 84 km2 and collected 3 185 Zostera noltei ramets from 803 sites. We estimated clone age, assuming rhizome elongation as the only mechanism of clone spread, and contrasted it with paleo-oceanographic sea level change. We also studied the association between a source of disturbance and the location of large clones. A total of 16 clones were sampled more than 10 times and the most abundant one was sampled 59 times. The largest distance between two samples from the same clone was 26.4 km and a total of 58 and 10 clones were sampled across more than 2 and 10 km, respectively. The number of extremely large clone sizes, and their old ages when assuming the rhizome elongation as the single causal mechanism, suggests other processes are behind the span of these clones. We discuss how the dispersal of vegetative fragments in a stepping-stone manner might have produced this pattern. We found higher probabilities to sample large clones away from the lagoon inlet, considered a source of disturbance. This study corroborates previous experiments on the success of transport and re-establishment of asexual fragments and supports the hypothesis that asexual hydrochory is responsible for the extent of these clones.

scholarly journals A comparative evaluation of biological activities and bioactive compounds of the seagrasses Zostera marina and Zostera noltei from southern Portugal

2015 ◽  
Vol 30 (6) ◽  
pp. 724-728 ◽  
Author(s):  
Luísa Custódio ◽  
Simona Laukaityte ◽  
Aschwin H. Engelen ◽  
Maria João Rodrigues ◽  
Hugo Pereira ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Zostera Marina ◽  
Comparative Evaluation ◽  
Biological Activities ◽  
Zostera Noltei ◽  
Southern Portugal

scholarly journals Nested Socio-Ecological Maps as a Spatial Planning Instrument for Estuary Conservation and Ecosystem-Based Management

2021 ◽  
Vol 8 ◽  
Author(s):  
Cristina Galván ◽  
Araceli Puente ◽  
José A. Juanes
Keyword(s):  
Potential Distribution ◽  
Management Education ◽  
Conservation Management ◽  
Ecological Systems ◽  
Distribution Model ◽  
Spatially Explicit ◽  
Ecological Change ◽  
Cumulative Impacts ◽  
Abiotic Conditions ◽  
Zostera Noltei

Estuaries are socio-ecological systems that can be represented as a holistic combination of biotic and abiotic conditions in spatially explicit units defined by: (i) the ecotope, as the integration of the physiotope (abiotic-homogeneous units) and the biotope (biotic-homogeneous units), and (ii) the anthrotope, synthesizing data on human drivers of ecological change. Nested physiotopes were identified in an estuary using a hierarchical approach that integrates information about eight abiotic, and biologically meaningful, variables. The biotope of Zostera noltei was delimited using a potential distribution model of species and overlapped with the physiotope map to characterize the ecotopes. The anthrotope was estimated as the cumulative impacts of anthropic activities over the ecotopes. The diversity of Z. noltei ecotopes was compared with the anthrotope map to estimate the potential impacts of human pressures on this species. The hierarchical methodology and resulting maps provide flexible and interdisciplinary tools for conservation, management, education and research.

Electron energy-loss near-edge structure in silicate minerals

1992 ◽  
Vol 50 (2) ◽  
pp. 1258-1259
Author(s):  
D W McComb ◽  
R S Payne ◽  
P L Hansen ◽  
R Brydson
Keyword(s):  
Solid State ◽  
Energy Loss ◽  
Electron Energy ◽  
State Energy ◽  
Local Environment ◽  
Edge Structure ◽  
Silicate Minerals ◽  
Two Samples ◽  
Electron Energy Loss ◽  
Careful Processing

Electron energy-loss near-edge structure (ELNES) is an effective probe of the local geometrical and electronic environment around particular atomic species in the solid state. Energy-loss spectra from several silicate minerals were mostly acquired using a VG HB501 STEM fitted with a parallel detector. Typically a collection angle of ≈8mrad was used, and an energy resolution of ≈0.5eV was achieved.Other authors have indicated that the ELNES of the Si L2,3-edge in α-quartz is dominated by the local environment of the silicon atom i.e. the SiO4 tetrahedron. On this basis, and from results on other minerals, the concept of a coordination fingerprint for certain atoms in minerals has been proposed. The concept is useful in some cases, illustrated here using results from a study of the Al2SiO5 polymorphs (Fig.l). The Al L2,3-edge of kyanite, which contains only 6-coordinate Al, is easily distinguished from andalusite (5- & 6-coordinate Al) and sillimanite (4- & 6-coordinate Al). At the Al K-edge even the latter two samples exhibit differences; with careful processing, the fingerprint for 4-, 5- and 6-coordinate aluminium may be obtained.

Mental representation of economic crisis in Italian and Swiss samples 1The authors would like to thank Maurizio Mistri for his help in the construction of items. This research was supported by a grant from the Italian Murst (ex 40%).

2001 ◽  
Vol 60 (1) ◽  
pp. 11-14 ◽  
Author(s):  
Lucia Savadori ◽  
Eraldo Nicotra ◽  
Rino Rumiati ◽  
Roberto Tamborini
Keyword(s):  
Economic Crisis ◽  
Mental Representation ◽  
Mental Representations ◽  
Social Contexts ◽  
Raw Material ◽  
National Context ◽  
Cluster Procedure ◽  
Total N ◽  
Two Samples ◽  
Important Symptom

The content and structure of mental representation of economic crises were studied and the flexibility of the structure in different social contexts was tested. Italian and Swiss samples (Total N = 98) were compared with respect to their judgments as to how a series of concrete examples of events representing abstract indicators were relevant symptoms of economic crisis. Mental representations were derived using a cluster procedure. Results showed that the relevance of the indicators varied as a function of national context. The growth of unemployment was judged to be by far the most important symptom of an economic crisis but the Swiss sample judged bankruptcies as more symptomatic than Italians who considered inflation, raw material prices and external accounts to be more relevant. A different clustering structure was found for the two samples: the locations of unemployment and gross domestic production indicators were the main differences in representations.

Men Are Hierarchical, Women Are Egalitarian: An Implicit Gender Stereotype

2004 ◽  
Vol 63 (2) ◽  
pp. 107-111 ◽  
Author(s):  
Marianne Schmid Mast
Keyword(s):  
Empirical Evidence ◽  
Implicit Association Test ◽  
Gender Stereotype ◽  
Association Test ◽  
Implicit Association ◽  
Two Samples

The goal of the present study was to provide empirical evidence for the existence of an implicit hierarchy gender stereotype indicating that men are more readily associated with hierarchies and women are more readily associated with egalitarian structures. To measure the implicit hierarchy gender stereotype, the Implicit Association Test (IAT, Greenwald et al., 1998) was used. Two samples of undergraduates (Sample 1: 41 females, 22 males; Sample 2: 35 females, 37 males) completed a newly developed paper-based hierarchy-gender IAT. Results showed that there was an implicit hierarchy gender stereotype: the association between male and hierarchical and between female and egalitarian was stronger than the association between female and hierarchical and between male and egalitarian. Additionally, men had a more pronounced implicit hierarchy gender stereotype than women.

Symptoms of Alcohol Dependence Predict Suicide Ideation Among Alaskan Undergraduates

Crisis ◽  
2016 ◽  
Vol 37 (3) ◽  
pp. 232-235 ◽  
Author(s):  
Christopher R. DeCou ◽  
Monica C. Skewes
Keyword(s):  
Depressive Symptoms ◽  
Alcohol Consumption ◽  
Alcohol Dependence ◽  
Suicide Ideation ◽  
Alcohol Problems ◽  
Future Research ◽  
Causal Mechanism ◽  
Students At Risk ◽  
The Relationship ◽  
Alcohol Related Problems

Abstract. Background: Previous research has demonstrated an association between alcohol-related problems and suicidal ideation (SI). Aims: The present study evaluated, simultaneously, alcohol consequences and symptoms of alcohol dependence as predictors of SI after adjusting for depressive symptoms and alcohol consumption. Method: A sample of 298 Alaskan undergraduates completed survey measures, including the Young Adult Alcohol Consequences Questionnaire, the Short Alcohol Dependence Data Questionnaire, and the Beck Depression Inventory – II. The association between alcohol problems and SI status was evaluated using sequential logistic regression. Results: Symptoms of alcohol dependence (OR = 1.88, p < .05), but not alcohol-related consequences (OR = 1.01, p = .95), emerged as an independent predictor of SI status above and beyond depressive symptoms (OR = 2.39, p < .001) and alcohol consumption (OR = 1.08, p = .39). Conclusion: Alcohol dependence symptoms represented a unique risk for SI relative to alcohol-related consequences and alcohol consumption. Future research should examine the causal mechanism behind the relationship between alcohol dependence and suicidality among university students. Assessing the presence of dependence symptoms may improve the accuracy of identifying students at risk of SI.

Question Wording Effects in the Assessment of Global Self-Esteem

2000 ◽  
Vol 16 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Martin Dunbar ◽  
Graeme Ford ◽  
Kate Hunt ◽  
Geoff Der
Keyword(s):  
Reading Ability ◽  
Factor Model ◽  
Self Esteem ◽  
Reading Scores ◽  
Poor Reading ◽  
Method Effect ◽  
Two Samples ◽  
Positive Item ◽  
Method Effects ◽  
Best Fit

Summary: Marsh (1996) produced evidence that method effects associated with negatively worded items might be responsible for the results of earlier factor analytic studies that reported finding positive and negative self-esteem factors in the Rosenberg Global self-esteem scale ( Rosenberg, 1965 ). He analyzed data collected from children using a 7-item self-esteem measure. This report details attempts to replicate Marsh 's analysis in data collected from two samples of adults who completed the full 10-item Global Self-Esteem (GSE) scale. The results reported here are similar to those given by Marsh in so much as a correlated uniquenesses model produced a superior fit to the data than the simple one factor model (without correlated uniquenesses) or the often reported two factor (positive and negative self-esteem) model. However, whilst Marsh reported that the best fit was produced by allowing negative item uniquenesses to correlate with each other, the model that produced the best fit to these data was one that contained correlated positive item uniquenesses. Supporting his claim that differential responding to negative and positive self-esteem items reflects a method effect associated with reading ability, Marsh also showed that factors associated with negative and positive items were most distinct among children who had poor reading scores. We report a similar effect among a sample of older adults where the correlation between these factors was compared across two groups who were selected according to their scores on a test of verbal reasoning.

Spearman's Law of Diminishing Returns

2006 ◽  
Vol 27 (4) ◽  
pp. 199-207 ◽  
Author(s):  
Peter Hartmann
Keyword(s):  
Principal Axis ◽  
Age Groups ◽  
Principal Component ◽  
Longitudinal Survey ◽  
Male And Female ◽  
Two Samples ◽  
Diminishing Returns ◽  
The One ◽  
Armed Services ◽  
Principal Axis Factor

Spearman's Law of Diminishing Returns (SLODR) with regard to age was tested in two different databases from the National Longitudinal Survey of Youth. The first database consisted of 6,980 boys and girls aged 12–16 from the 1997 cohort ( NLSY 1997 ). The subjects were tested with a computer-administered adaptive format (CAT) of the Armed Services Vocational Aptitude Battery (ASVAB) consisting of 12 subtests. The second database consisted of 11,448 male and female subjects aged 15–24 from the 1979 cohort ( NLSY 1979 ). These subjects were tested with the older 10-subtest version of the ASVAB. The hypothesis was tested by dividing the sample into Young and Old age groups while keeping IQ fairly constant by a method similar to the one developed and employed by Deary et al. (1996) . The different age groups were subsequently factor-analyzed separately. The eigenvalue of the first principal component (PC1) and the first principal axis factor (PAF1), and the average intercorrelation of the subtests were used as estimates of the g saturation and compared across groups. There were no significant differences in the g saturation across age groups for any of the two samples, thereby pointing to no support for this aspect of Spearman's “Law of Diminishing Returns.”

Structuring Assessments of Psychopathology

2006 ◽  
Vol 27 (2) ◽  
pp. 87-92 ◽  
Author(s):  
Willem K.B. Hofstee ◽  
Dick P.H. Barelds ◽  
Jos M.F. Ten Berge
Keyword(s):  
Principal Components ◽  
Personality Assessment ◽  
Clinical Sample ◽  
Principal Component ◽  
Normal Sample ◽  
Normative Sample ◽  
Assessment Data ◽  
Obsessive Compulsive ◽  
Oblique Rotation ◽  
Two Samples

Hofstee and Ten Berge (2004a) have proposed a new look at personality assessment data, based on a bipolar proportional (-1, .. . 0, .. . +1) scale, a corresponding coefficient of raw-scores likeness L = ΢XY/N, and raw-scores principal component analysis. In a normal sample, the approach resulted in a structure dominated by a first principal component, according to which most people are faintly to mildly socially desirable. We hypothesized that a more differentiated structure would arise in a clinical sample. We analyzed the scores of 775 psychiatric clients on the 132 items of the Dutch Personality Questionnaire (NPV). In comparison to a normative sample (N = 3140), the eigenvalue for the first principal component appeared to be 1.7 times as small, indicating that such clients have less personality (social desirability) in common. Still, the match between the structures in the two samples was excellent after oblique rotation of the loadings. We applied the abridged m-dimensional circumplex design, by which persons are typed by their two highest scores on the principal components, to the scores on the first four principal components. We identified five types: Indignant (1-), Resilient (1-2+), Nervous (1-2-), Obsessive-Compulsive (1-3-), and Introverted (1-4-), covering 40% of the psychiatric sample. Some 26% of the individuals had negligible scores on all type vectors. We discuss the potential and the limitations of our approach in a clinical context.

Development and Psychometric Evaluation of a Revised Sense of Coherence Scale

2018 ◽  
Vol 34 (3) ◽  
pp. 206-215 ◽  
Author(s):  
Rahel Bachem ◽  
Andreas Maercker
Keyword(s):  
Posttraumatic Growth ◽  
Factor Structure ◽  
Sense Of Coherence ◽  
Psychological Health ◽  
Psychometric Evaluation ◽  
Health Indicators ◽  
Structure Stability ◽  
Confirmatory Factor Analyses ◽  
Reliability Factor ◽  
Two Samples

Abstract. The present study introduces a revised Sense of Coherence (SOC) scale, a new conceptualization and operationalization of the resilience indicator SOC. It outlines the scale development and aims for testing its reliability, factor structure, and validity. Literature on Antonovsky’s SOC (SOC-A) was critically reviewed to identify needs for improving the scale. The scale was investigated in two samples. Sample 1 consisted of 334 bereaved participants, Sample 2 of 157 healthy controls. The revised SOC Scale, SOC-A, and theoretically relevant questionnaires were applied. Explorative and confirmatory factor analyses established a three-factor structure in both samples. The revised SOC Scale showed significant but discriminative associations with related constructs, including self-efficacy, posttraumatic growth, and neuroticism. The revised measure was significantly associated with psychological health indicators, including persistent grief, depression, and anxiety, but not to the extent as the previous SOC-A. Stability over time was sufficient. The study provides psychometric support for the revised SOC conceptualization and scale. It has several advantages over the previous SOC-A scale (unique variance, distinct factor structure, stability). The scale could be used for clinical and health psychological testing or research into the growing field of studies on resilience over the life span.

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