Lateral outward growth of single-crystal diamond by two different structures of microwave plasma reactors

On a semi-open holder, the homoepitaxial lateral growth of single-crystal diamond (SCD) was carried out via microwave plasma chemical vapor deposition (MPCVD). By tuning and optimizing two different structures of...

Taxonomic history, comparative morphology, and variation in Astrophytum myriostigma and its subspecies tulense (Cactaceae)

Astrophytum myriostigma subsp. myriostigma and subsp. tulense are distinguished by both vegetative and reproductive characters. The stem of the nominotypical subspecies is broad and depressed becoming broadly cylindrical in age, reaching a known maximum height of ca. 52 cm. In subsp. tulense, the stem is relatively slen-der and columnar and can reach a maximum height of ca. 90 cm. Both taxa show variation in the angle and profile of the ribs. In the nominotypical subspecies, the ribs are usually obtuse with a rounded or angular profile, or moderately acute with an angular profile. In subsp. tulense, the ribs are typically moderately to very acute with an angular profile. There are exceptions to these generalities. Both taxa have a modal number of five ribs, and both have the tendency to insert additional ribs with age, although the tendency seems more pronounced in subsp. tulense. The flower of the nominotypical subspecies differs from that of subsp. tulense in having a significantly larger mean perianth diameter (P <= 0.01), a significantly higher mean number of stigma lobes (P <= 0.05), and more tepal rows (3–5 vs. 1–3). The color of the tepals is pale yellow to whitish yellow in subsp. tulense, but brighter yellow or golden yellow in the nominotypical subspecies. The seeds of the nominotypical subspecies are significantly larger (P <= 0.01) than the seeds of subsp. tulense. Morphological variation was studied in nine populations of the subsp. myriostigma and six populations of the subsp. tulense. The nominotypical subspecies displays rib angle and rib profile differences among individual plants within a population. Plants with a depressed stem and obtuse, rounded ribs are predominant at some localities. At other localities, plants with more moderately acute, angular ribs are predominant, or at least common. Populations of subsp. tulense show individual variation in stem morphology. The stem varies from attenuated (tapered) to non-attenuated and from relatively slender (diameter ca. 20% of height) to relatively broad (diameter ca. 77% of height). The plants from near Mama León and adjacent localities in Tamaulipas, have very robust stems and are the least typical of the columnar subspecies. The rela-tionships of this population to other columnar populations warrant further study. The population near Las Tablas, San Luis Potosí, shows considerable variation in the stem and rib morphology. Some plants resemble the nominotypical subspecies whereas others are similar morphologically to subsp. tulense. The perianth diameter is intermediate between those of the two subspecies. The evidence suggests that this is an area of past or ongoing hybridization between the two taxa; the question of hybridization warrants further investigation. Attenuated and non-attenuated stems are the result of differential rates of vertical and lateral growth due to cellular activity in the apical and lateral meristems, respectively. The attenuated (tapered) stem is produced by a gradually increasing lateral growth rate which remains slower than the vertical rate. A non-attenuated stem is produced by the lateral growth rate exceeding the vertical rate early in development, then stabilizing at some point and not surpassing the vertical rate.

Aerial high-throughput phenotyping of peanut leaf area index and lateral growth

Leaf area index (LAI) is the ratio of the total one-sided leaf area to the ground area, whereas lateral growth (LG) is the measure of canopy expansion. They are indicators for light capture, plant growth, and yield. Although LAI and LG can be directly measured, this is time consuming. Healthy leaves absorb in the blue and red, and reflect in the green regions of the electromagnetic spectrum. Aerial high-throughput phenotyping (HTP) may enable rapid acquisition of LAI and LG from leaf reflectance in these regions. In this paper, we report novel models to estimate peanut (Arachis hypogaea L.) LAI and LG from vegetation indices (VIs) derived relatively fast and inexpensively from the red, green, and blue (RGB) leaf reflectance collected with an unmanned aerial vehicle (UAV). In addition, we evaluate the models’ suitability to identify phenotypic variation for LAI and LG and predict pod yield from early season estimated LAI and LG. The study included 18 peanut genotypes for model training in 2017, and 8 genotypes for model validation in 2019. The VIs included the blue green index (BGI), red-green ratio (RGR), normalized plant pigment ratio (NPPR), normalized green red difference index (NGRDI), normalized chlorophyll pigment index (NCPI), and plant pigment ratio (PPR). The models used multiple linear and artificial neural network (ANN) regression, and their predictive accuracy ranged from 84 to 97%, depending on the VIs combinations used in the models. The results concluded that the new models were time- and cost-effective for estimation of LAI and LG, and accessible for use in phenotypic selection of peanuts with desirable LAI, LG and pod yield.

Modeling of abnormal grain growth in (111) oriented and nanotwinned copper

Uni-modal, not bi-modal, of abnormal grain growth has been observed in (111) oriented and nano-twinned Cu films. Because of the highly anisotropic microstructure, our kinetic analysis and calculation showed that it is the mobility which dominates the uni-modal growth, in which the lateral growth rate can be two orders of magnitude higher than the vertical growth rate. As a consequence, the abnormal grain growth has been converted from bi-modal to uni-modal.

A longitudinal cohort study of adolescent elite footballers and controls investigating the development of cam morphology

Cam morphology describes an asphericity of the femoral head that develops during adolescence, is highly prevalent in athletes, and predisposes individuals to future osteoarthritis. However, it’s aetiology remains poorly understood. The aim of this study was to perform 3-year longitudinal follow-up of a control population and football club academy cohort to compare the change in hip and growth plate anatomy between athletes and controls. MRI and questionnaires were used to characterise change in hip and growth plate anatomy and quantify activity levels. 121 male academy footballers and 107 male and female controls participated at baseline. Footballers experienced significantly greater increases in femoral head asphericity (4.83 degrees (95% CI: 2.84 to 6.82), p < 0.001) than controls. A positive correlation existed between activity levels and change in femoral head morphology (coefficient 0.79, p ≤ 0.001). Greatest morphological change occurred in individuals aged 11–12 years at baseline, with no significant change in individuals aged 14 years and older at baseline. Cam morphology development was secondary to soft tissue hypertrophy and lateral growth plate extension. In conclusion, excessive loading of the hip joint through exercise prior to 14 years of age may result in growth plate adaptations causing cam morphology. Potential interventions may include training type and load modification in young adolescent football players.

Southward growth of Mauna Loa’s dike-like magma body driven by topographic stress

Space-geodetic observations of a new period of inflation at Mauna Loa volcano, Hawaii, recorded an influx of 0.11 km3 of new magma into it’s dike-like magma body during 2014–2020. The intrusion started after at least 4 years of decollement slip under the eastern flank creating > 0.15 MPa opening stresses in the rift zone favorable for magma intrusion. Volcanoes commonly respond to magma pressure increase with the injection of a dike, but Mauna Loa responded with lateral growth of its magma body in the direction of decreasing topographic stress. In 2017, deformation migrated back, and inflation continued at the pre-2015 location. Geodetic inversions reveal a 8 × 8.5, 10 × 3 and 9 × 4 km2 dike-like magma body during the 2014–2015, 2015–2018 and 2018–2020 periods, respectively, and an average decollement slip of ~ 23 cm/year along a 10 × 5 km2 fault. The evolution of the dike-like magma body including the reduction in vertical extent is consistent with a slowly ascending dike propagating laterally when encountering a stress barrier and freezing its tip when magma influx waned. Overall, the magma body widened about 4.5 m during 2002–2020.