Sexual dimorphism of structures showing indeterminate growth: tusks of American mastodons (Mammut americanum)

Paleobiology ◽  
2011 ◽  
Vol 37 (2) ◽  
pp. 175-194 ◽  
Author(s):  
Kathlyn M. Smith ◽  
Daniel C. Fisher
Keyword(s):  
Sexual Dimorphism ◽  
Great Lakes Region ◽  
Ontogenetic Changes ◽  
Indeterminate Growth ◽  
Opposite Sex ◽  
Determinate Growth ◽  
Components Analysis ◽  
The Relationship ◽  
Mammut Americanum ◽  
External Form

Documenting sexual dimorphism for structures that exhibit indeterminate growth can be more difficult than for structures exhibiting determinate growth. Most proboscidean tusks are ever-growing structures that change size and shape throughout life. Sexual dimorphism is pronounced in tusks of mature individuals, but the external form of tusks offers no clear evidence of maturation, and it is difficult to distinguish a young male's tusk from that of an older female. Thus, with previous approaches, knowledge of age was often required to assess sex from tusk measurements. This study examines sexual dimorphism of American mastodon (Mammut americanum) tusks through principal components analysis to determine which aspects of tusk form contribute most strongly to the variance among measurements and to explore the relationship between tusk form and individual age and sex. Twenty-one mastodon tusks from the Great Lakes region were evaluated in two analyses, the first focusing on geometrically distinct aspects of tusk form and the second adding measurements that reflect ontogenetic changes in a single aspect of morphology (circumference). Both analyses separated mastodons by sex (PC-I) and sorted them by age (PC-II). The distribution of tusks on the PC-II versus PC-I plane provides better discrimination of sex than univariate or bivariate methods because tusks of similar size and opposite sex appear near opposite ends of an age spectrum. The second analysis enhances sorting by age, thereby clarifying assessment of sex. This work contributes to studies of mastodon paleobiology by presenting a reliable method for assessing the sex of an individual from tusk measurements without requiring independent knowledge of age.

The relationship between bud scale morphology and indeterminate and determinate growth patterns in Acer (Aceraceae)

1990 ◽  
Vol 68 (1) ◽  
pp. 144-148 ◽  
Author(s):  
Satoki Sakai
Keyword(s):  
Growth Pattern ◽  
Growth Patterns ◽  
Species Loss ◽  
Scale Morphology ◽  
Indeterminate Growth ◽  
Lateral Buds ◽  
Determinate Growth ◽  
Terminal Buds ◽  
The Relationship ◽  
Bud Morphology

Bud scale morphology was investigated for 18 species of Japanese Acer, including 12 species that exhibit indeterminate growth and 6 that exhibit determinate growth. The bud scales of the inner pairs of terminal buds and all bud scales of lateral buds exhibited different patterns of development in the two types of species. In the indeterminate species, the formation of rudimentary laminae was observed, whereas no laminae formation was observed in the determinate species. Loss of laminae could have occurred over the course of the evolutionary specialization of bud scales, since the bud scales of the indeterminate species are assumed to be more primitive than those of the determinate species. A consideration of the bud morphology of Dipteronia, an outgroup of Acer, supported this view. This study then suggests that in Acer a determinate growth pattern actually evolved from a pattern of indeterminate growth. It seems likely that for some member(s) of the genus Acer, sites of regeneration began to shift from sites containing less shady area to those containing more, and that this shift was associated with the evolution from indeterminate to determinate growth.

Visual Evoked-Response Correlates of Speechreading Performance in Normal-Hearing Adults

1983 ◽  
Vol 26 (1) ◽  
pp. 2-9 ◽  
Author(s):  
Vincent J. Samar ◽  
Donald G. Sims
Keyword(s):  
Multiple Correlation Coefficient ◽  
Evoked Response ◽  
Multiple Correlation ◽  
Potential Significance ◽  
Visual Evoked Response ◽  
Latency Measure ◽  
Two Measures ◽  
Components Analysis ◽  
The Relationship ◽  
Visual Evoked

The relationship between the latency of the negative peak occurring at approximately 130 msec in the visual evoked-response (VER) and speechreading scores was investigated. A significant product-moment correlation of -.58 was obtained between the two measures, which confirmed the fundamental effect but was significantly weaker than that previously reported in the literature (-.90). Principal components analysis of the visual evoked-response waveforms revealed a previously undiscovered early VER component, statistically independent of the latency measure, which in combination with two other components predicted speechreading with a multiple correlation coefficient of S4. The potential significance of this new component for the study of individual differences in speechreading ability is discussed.

The Two Components of Social Desirability and their Relations to Resting Frontal Brain Asymmetry

2005 ◽  
Vol 26 (1) ◽  
pp. 29-42 ◽  
Author(s):  
Cornelia A. Pauls ◽  
Jan Wacker ◽  
Nicolas W. Crost
Keyword(s):  
Impression Management ◽  
Big Five ◽  
Hemispheric Asymmetry ◽  
Incentive Motivation ◽  
Blink Rate ◽  
Frontal Brain ◽  
Self Reports ◽  
Opposite Sex ◽  
The Relationship ◽  
Α Band

Abstract. The aim of the present study was to investigate the relationships between resting frontal hemispheric asymmetry (FHA) in the low α band (8-10.25 Hz) and the two components of socially desirable responding, i.e., self-deceptive enhancement (SDE) and impression management (IM), in an opposite-sex encounter. In addition, Big Five facets, self-reports of emotion, and spontaneous eye blink rate (BR), a noninvasive indicator of functional dopamine activity, were assessed. SDE as well as IM were related to relatively greater right-than-left activity in the low α band (i.e., relative left frontal activation; LFA) and to self-reported positive affect (PA), but only SDE was related to BR. We hypothesized that two independent types of motivational approach tendencies underlie individual differences in FHA and PA: affiliative motivation represented by IM and agentic incentive motivation represented by SDE. Whereas the relationship between SDE and PA was mediated by BR, the relationship between SDE and FHA was not.

Menguji Kepuasan Hubungan Melalui Intimasi dan Perasaan Cemburu pada Pelaku Hubungan Friends with Benefits

2020 ◽  
Vol 10 (2) ◽  
pp. 114
Author(s):  
Putu Yunita Trisna Dewi ◽  
M. Arief Sumantri
Keyword(s):  
Relationship Satisfaction ◽  
Romantic Relationship ◽  
Descriptive Analysis ◽  
Friends With Benefits ◽  
Opposite Sex ◽  
Social Intimacy ◽  
Relationship Assessment ◽  
The Relationship ◽  
Assessment Scales

Friends with Benefits (FWB) is a friendship of the opposite sex that involves sexual activity without commitment, feelings of love and encouragement to continue the relationship toward a romantic relationship. This study aims to determine the role of intimacy and jealousy towards the relationship satisfaction of individuals undergoing the FWB and the role of jealousy towards intimacy, and describing the emotions and views of participants on their FWB relationships. The subjects were 304 people undergoing FWB relationship in the last two years. Data were collected using Miller Social Intimacy, Multidimensional Jealousy, and Relationship Assessment Scales. Hierarchical linear regression and descriptive analysis were used to analyze data. Participants’ experiences of their FBW relationship were also collected and analyzed qualitatively. The result showed that intimacy and jealousy significantly predicted the relationship satisfaction both simultaneously and partially. Jealousy also significantly influences intimacy. A qualitative analysis reveals three categories that describe the emotions and views of the participants towards their FWB  relationships, namely feeling satisfied and happy, feeling less satisfied and regretful, and feeling happy but regretful.Keywords : friends with benefits, intimacy, jealousy, relationship satisfaction. Abstrak: Friends with Benefits (FWB) adalah hubungan pertemanan lawan jenis yang melibatkan hubungan seksual tanpa komitmen, perasaan cinta dan dorongan untuk melanjutkan ke hubungan yang romantis. Penelitian ini bertujuan untuk menguji peranan intimasi dan perasaan cemburu terhadap kepuasan hubungan partisipan yang menjalani hubungan FWB, peranan perasaan cemburu terhadap intimasi, serta mendeskripsikan gambaran emosi dan pandangan partisipan saat menjalani hubungan FWB. Partisipan penelitian berjumlah 304 partisipan, yang menjalani hubungan FWB dalam kurun waktu dua tahun terakhir. Data dikumpulkan dengan skala Miller Social Intimacy, Multi-dimensional Jealousy, dan Relationship Assesment. Data dianalisis menggunakan regresi linier berjenjang. Data kualitatif juga dikumpulkan dan dianalisis secara deskriptif untuk mendalami perasaan dan pandangan partisipan terhadap FWB yang dijalani. Hasil penelitian menunjukkan intimasi dan perasaan cemburu secara signifikan mempengaruhi kepuasan hubungan baik secara simultan maupun parsial. Perasaan cemburu juga secara signifikan memberi pengaruh terhadap intimasi. Secara kualitatif, ditemukan tiga kategori yang menggambarkan emosi dan pandangan partisipan dalam menjalani hubungan FWB, yaitu merasa puas dan senang, kurang puas hingga menyesal, dan merasa senang namun ada penyesalan.

scholarly journals Twin Study of the Relationship between Childhood Negative Emotionality and Hyperactivity/Inattention Problems

2021 ◽  
Vol 24 (1) ◽  
pp. 7-13
Author(s):  
Yoon-Mi Hur ◽  
Hoe-Uk Jeong
Keyword(s):  
Genetic Factors ◽  
Environmental Influences ◽  
Model Fitting ◽  
Negative Emotionality ◽  
Phenotypic Correlation ◽  
Environmental Correlation ◽  
South Korean ◽  
Telephone Interviews ◽  
Opposite Sex ◽  
The Relationship

AbstractThe present study aimed to determine the genetic and environmental etiology of the association between childhood negative emotionality (NE) and hyperactivity/inattention problems (HIP) using South Korean elementary school twins (mean age = 10.19 years, SD = 1.79 years). Telephone interviews were given to mothers of 919 twins (229 monozygotic males: 112 pairs and 5 individuals; 148 dizygotic males: 73 pairs and 2 individuals; 180 monozygotic females: 87 pairs and 6 individuals; 103 dizygotic females: 50 pairs and 3 individuals; 259 opposite-sex dizygotic twins: 127 pairs and 5 individuals) to assess their children’s NE and HIP. Consistent with prior studies, the phenotypic correlation between NE and the HIP was moderate (r = .29; 95% CI = .24, .34). Model-fitting analysis revealed that additive genetic and nonshared environmental influences on NE were .45 (95% CI [.34, .54]) and .55 (95% CI [.46, .66]), respectively, and that additive and nonadditive genetic, and nonshared environmental influences on HIP were .08 (95% CI [.03, .26]), .41 (95% CI [.21, .51]) and .51 (95% CI = .42, .61), respectively. In addition, the additive genetic correlation between NE and HIP was 1.0 (95% CI [.52, 1.00]), indicating that additive genetic factors are entirely shared between the two phenotypes. Nonadditive genetic influences were unique to HIP and not responsible for the NE-HIP association. Nonshared environmental correlation was significant but modest (re = .18, 95% CI [.06, .30]).

Social identity, rationality, creativity

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Anna-Maria Kanzola ◽  
Konstantina Papaioannou ◽  
Panagiotis E. Petrakis
Keyword(s):  
Social Identity ◽  
Social Identity Theory ◽  
Identity Theory ◽  
Content Type ◽  
The Social ◽  
Social Theories ◽  
Seeking Behavior ◽  
Life Improvement ◽  
Components Analysis ◽  
The Relationship

PurposeThis study examines the relationship between rationality and creativity by means of social identity theory for the Greek society (2019–2020).Design/methodology/approachThe outline of the social identity was given through self-categorization via a distributed questionnaire. The types of behavior (rational, nonrational and loss-averse) were determined by using questions based on the Allais paradox. Principal components analysis (PCA) is used to extract the causal relationships.FindingsThe study findings demonstrate that rational individuals are more prompt to creative personality than nonrational individuals. Rational individuals are motivated to pursue creativity through life-improvement goals. Loss-averse individuals are driven through the contradictive incentive of adventure-seeking behavior without, however, being willing to easily give up their established assets.Originality/valueThis article contributes by explaining creativity among rational, nonrational and loss-averse individuals as a product of social identity theory. This contributes to the literature, by proposing that the application of social theories in economics could constitute a different foundation for economics. This refers to the notion of the social microfoundations of the political economy and macroeconomics.

Face Recognition Algorithm Based on Kernel Collaborative Representation

2013 ◽  
Vol 756-759 ◽  
pp. 3590-3595
Author(s):  
Liang Zhang ◽  
Ji Wen Dong
Keyword(s):  
Face Recognition ◽  
Principal Components Analysis ◽  
Principal Components ◽  
Recognition Algorithm ◽  
Experimental Results ◽  
Collaborative Representation ◽  
Nonlinear Structures ◽  
Components Analysis ◽  
Kernel Principal Components Analysis ◽  
The Relationship

Aiming at solving the problems of occlusion and illumination in face recognition, a new method of face recognition based on Kernel Principal Components Analysis (KPCA) and Collaborative Representation Classifier (CRC) is developed. The KPCA can obtain effective discriminative information and reduce the feature dimensions by extracting faces nonlinear structures features, the decisive factor. Considering the collaboration among the samples, the CRC which synthetically consider the relationship among samples is used. Experimental results demonstrate that the algorithm obtains good recognition rates and also improves the efficiency. The KCRC algorithm can effectively solve the problem of illumination and occlusion in face recognition.

Birthweight and Adult Health in a Population-Based Sample of Norwegian Twins

2005 ◽  
Vol 8 (2) ◽  
pp. 148-155 ◽  
Author(s):  
Andrej M. Grjibovski ◽  
Jennifer R. Harris ◽  
Per Magnus
Keyword(s):  
Health Outcomes ◽  
Population Based ◽  
Adult Health ◽  
Brain Disorder ◽  
Full Sample ◽  
Intraclass Correlations ◽  
Opposite Sex ◽  
Lower Birthweight ◽  
The Relationship ◽  
Pair Analysis

AbstractPopulation-based twin data were used to test (a) whether lower birthweight confers a greater risk of adult health disorders, and (b) whether within-pair birthweight differences in twins explain discordance for health outcomes. The sample consisted of 1201 monozygotic (MZ) male twins, 1048 dizygotic (DZ) male twins, 1679 MZ female twins, 1489 DZ female twins, and 2423 opposite-sex DZ twins, born in Norway between 1967 and 1979. The relationship between birthweight and self-reported health outcomes were studied using multivariable logistic regression. In the full sample (n= 7840), birthweight was negatively associated with risk for nearsightedness (odds ratio OR = 0.76, 95% CI: 0.65 – 0.92) and minimal brain disorder (OR = 0.27, 95% CI: 0.16–0.44) when adjusted for gestational age, sex, zygosity, age, education and body mass index after correction for intraclass correlations and multiple comparisons. Within-pair analysis of 159 MZ and 224 DZ pairs revealed that myopic twins were on average 2 g (p= .966) and 64 g (p= .040) lighter than nonmyopic twins in MZ and DZ pairs respectively, suggesting that genetic factors may play an important role in the associations between birthweight and nearsightedness. Within-pair analysis of twins discordant for a minimal brain disorder indicated that affected twins were 80 g (p= .655) and 85 g (p= .655) lighter than their healthy co-twins in MZ and DZ pairs respectively, although there were only 2 MZ and 2 DZ discordant pairs.

Sign in / Sign up

Export Citation Format

Share Document