scholarly journals Pollen limitation and autonomous selfing ability interact to shape variation in outcrossing rate across a species range

2019 ◽  
Vol 106 (9) ◽  
pp. 1240-1247 ◽  
Author(s):  
Matthew H. Koski ◽  
Laura F. Galloway ◽  
Jeremiah W. Busch
Keyword(s):  
Pollen Limitation ◽  
Outcrossing Rate ◽  
Species Range ◽  
Shape Variation ◽  
Selfing Ability

The critical role of honeyeaters in the pollination of the catspaw Anigozanthos humilis (Haemodoraceae)

2019 ◽  
Vol 67 (4) ◽  
pp. 281
Author(s):  
Tayla van der Kroft ◽  
David G. Roberts ◽  
Siegfried L. Krauss
Keyword(s):  
Seed Set ◽  
Environmental Changes ◽  
Pollen Limitation ◽  
Critical Role ◽  
Outcrossing Rate ◽  
Camera Traps ◽  
Visitation Rates ◽  
Flowering Season ◽  
Hand Pollination ◽  
Study Population

The pollination biology of Anigozanthos humilis (Haemodoraceae) was studied within a Banksia woodland reserve using a combination of field techniques and genetic analysis. Motion-triggered cameras were deployed on 25 flowering plants to identify visitors to flowers, quantify visitation rates and assess visitor behaviour. Entire A. humilis plants were caged to exclude potential floral visitors with six treatments: (i) bird and honey possum exclusion, allowing access by insects; (ii) bird and insect exclusion, allowing access by honey possums; (iii) total animal exclusion; (iv) open, allowing access by birds, insects and honey possums; (v) hand-pollination with cross-pollen; and (vi) hand-pollination with self-pollen. Open pollinated seed were genotyped to assess mating system parameters including outcrossing rate. From 23424 h of surveillance with camera traps, 109 visits were recorded, 106 (97%) of which were western spinebills (Acanthorhynchus superciliosus), with three visits by brown honeyeaters (Lichmera indistincta). We recorded an average of 8 (±4) visits per plant, equivalent to one visit every eleven days over the 2016 flowering season (mean = 63 days). Mean seed set per fruit was negligible (0.2–0.3 seed per fruit) for all pollination treatments except open- and hand-pollination with cross pollen. Mean seed set per fruit for hand cross-pollinated flowers (37.1 seed per fruit) was 37 times that of open pollinated flowers (1.0 seed per fruit). Outcrossing rate estimates were not significantly different to one. Our results indicate that at least for the study population and season, A. humilis was largely dependent on western spinebills for delivery of outcross pollen and resulting seed set, but visitation rates were low and pollen limitation was severe. Given the known sensitivity of western spinebills to habitat fragmentation, our results suggest flow on effects that may negatively impact on reproduction, and means that A. humilis may be particularly vulnerable to environmental changes that impact on bird pollinators.

Learning body shape variation in physics-based characters

2019 ◽  
Vol 38 (6) ◽  
pp. 1-12 ◽  
Author(s):  
Jungdam Won ◽  
Jehee Lee
Keyword(s):  
Body Shape ◽  
Shape Variation

The assessment of the impact of mask pattern shape variation on the OPC-modeling by using SEM-Contours from wafer and mask

2011 ◽  
Author(s):  
Daisuke Hibino ◽  
Yutaka Hojyo ◽  
Hiroyuki Shindo ◽  
Thuy Do ◽  
Aasutosh Dave ◽  
...  
Keyword(s):  
Mask Pattern ◽  
Shape Variation ◽  
Pattern Shape ◽  
The Impact

scholarly journals Exploring palatal and dental shape variation with 3D shape analysis and geometric deep learning

2021 ◽  
Author(s):  
Nele Nauwelaers ◽  
Harold Matthews ◽  
Yi Fan ◽  
Balder Croquet ◽  
Hanne Hoskens ◽  
...  
Keyword(s):  
Deep Learning ◽  
Shape Analysis ◽  
Shape Variation ◽  
3D Shape ◽  
3D Shape Analysis

scholarly journals Carbon-chain molecules in molecular outflows and Lupus I region – new producing region and new forming mechanism

2019 ◽  
Vol 488 (1) ◽  
pp. 495-511
Author(s):  
Yuefang Wu ◽  
Xunchuan Liu ◽  
Xi Chen ◽  
Lianghao Lin ◽  
Jinghua Yuan ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Molecular Cloud ◽  
Carbon Chain ◽  
Species Range ◽  
Chain Molecules ◽  
Forming Mechanism ◽  
Molecular Outflows ◽  
Chemical Models ◽  
Cloud Complex

Abstract Using the new equipment of the Shanghai Tian Ma Radio Telescope, we have searched for carbon-chain molecules (CCMs) towards five outflow sources and six Lupus I starless dust cores, including one region known to be characterized by warm carbon-chain chemistry (WCCC), Lupus I-1 (IRAS 15398-3359), and one TMC-1 like cloud, Lupus I-6 (Lupus-1A). Lines of HC3N J = 2 − 1, HC5N J = 6 − 5, HC7N J = 14 − 13, 15 − 14, 16 − 15, and C3S J = 3 − 2 were detected in all the targets except in the outflow source L1660 and the starless dust core Lupus I-3/4. The column densities of nitrogen-bearing species range from 1012 to 1014 cm−2 and those of C3S are about 1012 cm−2. Two outflow sources, I20582+7724 and L1221, could be identified as new carbon-chain-producing regions. Four of the Lupus I dust cores are newly identified as early quiescent and dark carbon-chain-producing regions similar to Lup I-6, which together with the WCCC source, Lup I-1, indicate that carbon-chain-producing regions are popular in Lupus I which can be regard as a Taurus-like molecular cloud complex in our Galaxy. The column densities of C3S are larger than those of HC7N in the three outflow sources I20582, L1221, and L1251A. Shocked carbon-chain chemistry is proposed to explain the abnormal high abundances of C3S compared with those of nitrogen-bearing CCMs. Gas-grain chemical models support the idea that shocks can fuel the environment of those sources with enough S+ thus driving the generation of S-bearing CCMs.

scholarly journals A developmentally descriptive method for quantifying shape in gastropod shells

2020 ◽  
Vol 17 (163) ◽  
pp. 20190721
Author(s):  
J. Larsson ◽  
A. M. Westram ◽  
S. Bengmark ◽  
T. Lundh ◽  
R. K. Butlin
Keyword(s):  
Empirical Studies ◽  
Three Dimensional ◽  
Shell Shape ◽  
Large Set ◽  
Littorina Saxatilis ◽  
Shape Variation ◽  
Gastropod Shell ◽  
Geometric Morphometric ◽  
Wide Range ◽  
Descriptive Method

The growth of snail shells can be described by simple mathematical rules. Variation in a few parameters can explain much of the diversity of shell shapes seen in nature. However, empirical studies of gastropod shell shape variation typically use geometric morphometric approaches, which do not capture this growth pattern. We have developed a way to infer a set of developmentally descriptive shape parameters based on three-dimensional logarithmic helicospiral growth and using landmarks from two-dimensional shell images as input. We demonstrate the utility of this approach, and compare it to the geometric morphometric approach, using a large set of Littorina saxatilis shells in which locally adapted populations differ in shape. Our method can be modified easily to make it applicable to a wide range of shell forms, which would allow for investigations of the similarities and differences between and within many different species of gastropods.

scholarly journals Meta-analysis reveals severe pollen limitation for the flowering plants growing in East Himalaya-Hengduan Mountains region

BMC Ecology ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Xianfeng Jiang ◽  
Yanping Xie
Keyword(s):  
Confidence Interval ◽  
Pollen Limitation ◽  
Meta Analysis ◽  
Flowering Plants ◽  
Biodiversity Hotspot ◽  
Clear Relationship ◽  
Hengduan Mountains ◽  
Independent Data ◽  
The World ◽  
Global Biodiversity

Abstract Background Pollen limitation occurs widely and has an important effect on flowering plants. The East Himalaya-Hengduan Mountains region is a global biodiversity hotspot. However, to our knowledge, no study has synthetically assessed the degree of pollen limitation in this area. The present study aims to reveal the degree of pollen limitation for the flowering plants growing on East Himalaya-Hengduan Mountains and to test whether the reproductive features or the elevation is closely correlated with the degree of pollen limitation in this area. Results We complied data from 76 studies, which included 96 species and 108 independent data records. We found that the flowering plants in this area undergo severe pollen limitation [overall Hedges’ d = 2.004, with a 95% confidence interval (1.3264, 2.6743)] that is much higher than that of the flowering plants growing in many other regions around the world. The degree of pollen limitation was tested to determine the correlation with the capacity for autonomous self-reproduction and with the pollination pattern (generalized vs. specialized pollination) of plants. In addition, we found a clear relationship between elevation and the degree of pollen limitation, which indicates that plants might undergo more severe pollen limitation in relatively high places. Conclusions This paper is the first to address the severe pollen limitation of the flowering plants growing in East Himalaya-Hengduan Mountains region. Moreover, we reveal the positive correlation between elevation and the degree of pollen limitation.

scholarly journals Variation of the Three-Dimensional Femoral J-Curve in the Native Knee

2021 ◽  
Vol 11 (7) ◽  
pp. 592
Author(s):  
Sonja A. G. A. Grothues ◽  
Klaus Radermacher
Keyword(s):  
Geometric Parameter ◽  
Knee Kinematics ◽  
Size Variation ◽  
Principal Component ◽  
Parameter Analysis ◽  
Patient Specific ◽  
3D Analysis ◽  
Relative Location ◽  
Shape Variation ◽  
J Curve

The native femoral J-Curve is known to be a relevant determinant of knee biomechanics. Similarly, after total knee arthroplasty, the J-Curve of the femoral implant component is reported to have a high impact on knee kinematics. The shape of the native femoral J-Curve has previously been analyzed in 2D, however, the knee motion is not planar. In this study, we investigated the J-Curve in 3D by principal component analysis (PCA) and the resulting mean shapes and modes by geometric parameter analysis. Surface models of 90 cadaveric femora were available, 56 male, 32 female and two without respective information. After the translation to a bone-specific coordinate system, relevant contours of the femoral condyles were derived using virtual rotating cutting planes. For each derived contour, an extremum search was performed. The extremum points were used to define the 3D J-Curve of each condyle. Afterwards a PCA and a geometric parameter analysis were performed on the medial and lateral 3D J-Curves. The normalized measures of the mean shapes and the aspects of shape variation of the male and female 3D J-Curves were found to be similar. When considering both female and male J-Curves in a combined analysis, the first mode of the PCA primarily consisted of changes in size, highlighting size differences between female and male femora. Apart from changes in size, variation regarding aspect ratio, arc lengths, orientation, circularity, as well as regarding relative location of the 3D J-Curves was found. The results of this study are in agreement with those of previous 2D analyses on shape and shape variation of the femoral J-Curves. The presented 3D analysis highlights new aspects of shape variability, e.g., regarding curvature and relative location in the transversal plane. Finally, the analysis presented may support the design of (patient-specific) femoral implant components for TKA.

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