Mean Stem Length Research Articles

A comprehensive morphometric analysis of superior and inferior mesenteric arteries using cadaveric dissection and MDCT angiography

BackgroundSuperior mesenteric artery (SMA) and inferior mesenteric artery (IMA) are vital vascular structures supplying the majority of the intestinal tract. Despite their clinical significance, comprehensive morphometric studies combining traditional cadaveric dissection with modern imaging techniques are scarce in literature. This study aimed to provide a detailed morphometric analysis of the SMA and IMA using both cadaveric dissection and multi-detector computed tomography (MDCT) angiography. MethodsThe study utilized a dual approach, combining cadaveric dissection (30 formalin-fixed cadavers) and MDCT angiography (images from 50 patients). Measurements including stem lengths, diameters at origin, and distances from the aortic bifurcation were taken, along with assessment of vertebral levels of origin and branching patterns. Data from both components were analyzed using descriptive statistics. ResultsKey findings for SMA include: Mean stem length: 3.19 ± 0.72 cm (cadaveric) vs. 2.53 ± 0.53 cm (MDCT); Mean diameter at origin: 0.93 ± 0.22 cm (cadaveric) vs. 0.57 ± 0.10 cm (MDCT); Most common vertebral level of origin: Upper border of L1 (78 % of cases); Branching pattern variations observed in 23.3 % of cadaveric specimens, which included the origin of the inferior pancreaticoduodenal artery from the first jejunal artery, a common trunk for right colic and ileocolic arteries, and absence of middle colic artery. For IMA: Mean stem length: 3.61 ± 1.29 cm (cadaveric) vs. 3.41 ± 0.69 cm (MDCT); Mean diameter at origin: 0.50 ± 0.11 cm (cadaveric) vs. 0.26 ± 0.05 cm (MDCT); Most common vertebral level of origin: Upper border of L3 (40 % of cases). No variations observed in branching pattern. ConclusionsThe detailed measurements, frequency of variations, and comparison between traditional and modern assessment techniques offer a nuanced understanding of mesenteric vascular anatomy. This study bridges the gap between classical anatomical knowledge and contemporary imaging capabilities, potentially improving surgical planning, interventional procedures, and radiological interpretation.

Population-Based Evidence of Climate Change Adaptation in an Endangered Plant Endemic to a Biodiversity Hotspot.

Climate change is expected to impact both the population structure and geographic distribution of plants. Species distribution models are widely used to assess range shifts and the vulnerability of plants to climate change. Despite the abundance of modeling studies, little is known about how existing populations respond to climate change. We investigated the demographic structure and vulnerability to climate change in Anemone moorei, a sub-shrub with a highly restricted distribution in a biodiversity hotspot. We improved the distribution knowledge through intensive field work. We conducted a census of stem length as a proxy for age for all known populations. We used ensemble forecasting to project distributions considering 10 future climate scenarios and developed a novel climate change vulnerability index for the species' distribution. We found that the mean stem length decreases and the proportion of young plants increases, while the size of fruiting plants decreases as A. moorei faces greater climate change vulnerability. We interpret these results as evidence for the onset of recent adaptation to climate change, consisting of reduced adult longevity and an earlier onset of reproduction. As a result of these changes, the proportion of juveniles in the population increases.

Level of osteotomy is relevant to obtain better union and clinical results in patients with severe hip dysplasia operated on with total hip arthroplasty and shortening osteotomy using a cementless, rectangular femoral component.

Total hip arthroplasty with rectangular femoral component and transverse osteotomy for patients with Crowe type 3 or 4 dysplasia yields successful results with varying radiological findings. This study aims to investigate the surgery and patient related factors associated with successful clinical and radiological results. Fifty hips of 41 patients were retrospectively examined. Length and percentage of the stem passing the osteotomy level and canal fill ratio were measured. Radiological findings such as radiolucent lines (RL) around the stem, hypertrophic callus or an identifiable osteotomy line on X-ray images were assessed. All clinical and radiological results were analyzed for any significant association. Mean stem length and percentage passing the osteotomy level were 6.4cm (± 0.7)and 51% (± 6). Presence of an identifiable osteotomy line was positively associated with the increasing length of the stem passing the osteotomy level and with a lower HHS (p < 0.05). RL around the stem were associated with a lesser reduction in VAS score (p < 0.05). Rectangular femoral stem conveniently accommodate the proximal femur in severely dysplastic hips. An upper limit for the femoral stem exists to obtain better bony union and higher HHS. RL around the stem are clinically relevant and is associated with a worse VAS score at the latest follow-up.

An Allometric Growth Estimation of Grapes (&amp;lt;i&amp;gt;Vitis vinifera&amp;lt;/i&amp;gt; L) from High Mountainous Region of Gilgit-Baltistan, Pakistan

Grapes (<i>Vitis vinifera</i>), besides their medicinal and health importance, plays an important role in livelihood of poor populations living across mighty mountain ranges of Himalaya, Karakoram and Hindukush. Allometric study is necessary to understand quantitative correlations of tree growth. Hundred plant samples (n=100) from ten populations (N=10) were studied at an elevation of 1854 meters asl. Ten (N=10) different population studied revealed that mean leaf length is 10.9 cm (max. 13.4, min. 9.1 cm) followed by mean leaf width 8.4 cm (max. 9.3, min. 7.1 cm). total mean leaf area was 92.2 cm² (max. 122.6, min. 70.9 cm²). Mean stem length recorded was 26.8 feet (max. 35, min. 16 feet) followed by mean stem width 8.44 cm (max. 12.8, min. 3.1 cm). one thousand seeds were measured and mean seed weight recorded was 0.043 mg (max. 0.047, min. 0.039). similarly mean weight of hundred (n=100) seeds recorded was 4.29 g. research was summarized with the fact that stem length grows 98.97% faster than its width increase. Which means 1 cm with increase corresponds almost 100 cm increase in length. Similarly, leaf length increase is 23% higher to its growth in width. Ignorance towards a rich varietal base is on erosion.

Principles for Predicting RNA Secondary Structure Design Difficulty

Designing RNAs that form specific secondary structures is enabling better understanding and control of living systems through RNA-guided silencing, genome editing and protein organization. Little is known, however, about which RNA secondary structures might be tractable for downstream sequence design, increasing the time and expense of design efforts due to inefficient secondary structure choices. Here, we present insights into specific structural features that increase the difficulty of finding sequences that fold into a target RNA secondary structure, summarizing the design efforts of tens of thousands of human participants and three automated algorithms (RNAInverse, INFO-RNA and RNA-SSD) in the Eterna massive open laboratory. Subsequent tests through three independent RNA design algorithms (NUPACK, DSS-Opt and MODENA) confirmed the hypothesized importance of several features in determining design difficulty, including sequence length, mean stem length, symmetry and specific difficult-to-design motifs such as zigzags. Based on these results, we have compiled an Eterna100 benchmark of 100 secondary structure design challenges that span a large range in design difficulty to help test future efforts. Our in silico results suggest new routes for improving computational RNA design methods and for extending these insights to assess “designability” of single RNA structures, as well as of switches for in vitro and in vivo applications.

Sexual differences in morphology and aboveground biomass allocation in relation to branch number in Morus alba saplings

The effect of branch number on crown size and biomass accumulation has been reported for many trees, but knowledge about sexual differences in growth and aboveground biomass allocation related to branch number is still limited. Morus alba L. is a dioecious plant of economic importance, and was employed as a model species in our study. Thirty male and 30 female 1-month-old M. alba saplings with single or multiple (five) primary branches were cultivated for one growing season. Sexual differences in gas exchange, morphology, biomass accumulation and allocation, and relationships among morphological and biomass traits were investigated. Branch multiplication significantly increased the total leaf number, total leaf area, total leaf mass, aboveground mass, leaf : stem biomass ratio and specific leaf area at the plant level but decreased net photosynthetic rate (Pn), leaf number, mean single-leaf area, stem length, basal diameter and branch biomass at the branch level. Five-branch male saplings exhibited a significantly higher Pn, total leaf number, total leaf area, total leaf mass and aboveground biomass than did female ones. No such between plant sex differences were found in single-branch saplings. Further, branch number was positively correlated with aboveground mass in male saplings only. Our results demonstrate that branch multiplication might result in sexual differences in morphology and biomass accumulation and male saplings may allocate greater resources than females to aboveground parts for vegetative growth.

Year-round Greenhouse Production of Cut Sunflowers in the Rocky Mountain West

The objective of this study was to determine the potential for year-round greenhouse production of specialty cut sunflowers (Helianthus annuus) in Wyoming. Over a 14-month period, we produced cut sunflowers in a nontraditional, transplant-based, potted method using natural light intensity and daylength conditions in Laramie, WY. Three cultivars of annual sunflowers, Dafna, ProCut Bicolor, and Sunbright Supreme, were grown from seeds sown at 2-week intervals starting on 16 Nov. 2011. Each planting consisted of four replications of four plants each. Seedlings were transplanted into 550-mL square plastic pots 15 days after sowing and were placed on greenhouse benches in blocks according to sow date. Flowers were cut at soil level when ray florets opened. Data collected included days to harvest and stem length for each stem. Results indicated significant cultivar by sow date interactions for days to harvest and stem lengths, indicating the importance of cultivar selection. Mean days to harvest ranged from 57 days (‘Sunbright Supreme’) to 103 days (‘ProCut Bicolor’). Mean stem lengths ranged from 43 cm (‘Dafna’) to 153 cm (‘Sunbright Supreme’). Overall, the results of this study show potential for year-round production of cut sunflowers and can help guide producers in the Rocky Mountain west to choose cultivars that best fit the needs of their business and market demand.

Growth Rates of Edge-on Lamellar Crystals Confined in Polymer Thin Films

The growth rates of edge-on lamellar polymer crystals in variable thickness films were investigated in terms of dynamic Monte Carlo (MC) simulations. The growth rates linearly decreased with decreasing film thickness for the thinner films and were nearly constant for the thicker films. The mean stem lengths (crystal thickness) were also constant in different thickness films. The crystal widths parallel to the film thickness increased more slowly with increasing film thickness in the thinner films than that in the thicker films, indicating they were restrained by the film thickness. We propose that the growth rate of edge-on lamellar crystals in thin films is dominanted by the crystal width in the thinner films and by the crystal thickness in the thicker films; the variation of the film thickness can change the three-dimensional shape of the crystal growth front, also affecting the growth rate of the edge-on lamellar crystal.

Crystallization Kinetics of Lamellar Crystals Confined in Polymer Thin Films

We used dynamic Monte Carlo simulations to investigate the crystallization kinetics of flat-on lamellar polymer crystals in variable thickness films. We found that the growth rates linearly reduced with decreasing film thickness for the films thinner than a transition thickness dt , while they were constant for the films thicker than dt . Moreover, the mean stem lengths (crystal thickness) we calculated decreased with film thickness in a similar way to the growth rates, and the intramolecular crystallinities we calculated confirmed the film thickness dependence of the crytsal thickness. Besides, the crystal melting rates in thin films were calculated and increased with decreasing film thickness. We proposed a new interpretation on the film thickness dependence of the crystal growth rate in thin films, suggesting that it is dominated by the crystal thickness in terms of the driving force term (l–l min) expressed by Sadler, rather than the chain mobility based on experiments. The crystal thickness can determine whether a crystal grows or melts in a thin film at a fixed temperature, indicating the reversibility between the crystal growth and melting.

Effects of moisture, nitrogen, grass competition and simulated browsing on the survival and growth of Acacia karroo seedlings

AbstractThe effects of irrigation, nitrogen fertilization, grass competition and clipping were investigated for one growing season at the research farm of the University of Fort Hare in the Eastern Cape Province of South Africa. The aim of the experiment was to assess the short‐term performance of Acacia karroo seedlings under different environmental conditions and the implications of such factors on the long‐term recruitment of plant species in savanna rangelands. There were no significant treatment effects on the survival of A. karroo seedlings. Using stem length and basal diameter as growth parameters, it was observed that irrigation enhanced both variables, while nitrogen fertilization did not have any significant effects. Clipping, grass competition and their interaction greatly suppressed the growth of the seedlings. Clipping increased the mean stem length when they were irrigated and fertilized. Control and fertilized plants had the highest stem length in the absence of grass competition, while grass competition combined with clipping resulted in the lowest stem length in both irrigated and nonirrigated plants. It was concluded that in the presence of grass competition, controlled browsing could be a viable solution to the problem of bush encroachment in savanna rangelands.

Phenotypic effect of substitution of allelic variants for a histone H1 subtype specific for growing tissues in the garden pea (Pisum sativum L.).

In pea, subtype H1-7 of histone H1 is specific for young actively growing tissues and disappears from chromatin of mature tissues. We sequenced the alleles coding for three main variants, numbered according to the increase of the electrophoretic mobility. Allele 1 differs from the most common allele 2 by eight nucleotide substitutions, two of them associated with amino acid replacements, His->Tyr in the globular domain and Ala->Val in the C-terminal domain. Allele 3 differs from alleles 1 and 2 by a 24-bp deletion in the part coding for the C-terminal domain. In three greenhouse experiments, we compared quantitative traits in nearly isogenic lines differing by these H1-7 variants. In experiment 1, three lines bearing either of the three allelic variants were compared, the other experiments involved pairs of lines bearing variants 1 and 3. In all experiments, statistically significant differences between the lines were registered, mostly related to the plant size. The most prominent effect was associated with plant growth dynamics. Plants of line 3, carrying the 8-amino acid deletion in histone H1-7, on average grew slower. In two experiments, the differences of the mean stem length persisted throughout plant growth while in experiment 2 differences disappeared upon maturity. The H1-7 subtype is supposed to be related to maintenance of chromatin state characteristic for cell growth and division.

Production System Impacts Quality of Cut Poinsettia Stems

The development of the Renaissance series of cut poinsettias, Euphorbia pulcherrima, presents unique opportunities and challenges to cut flower producers. This series has curled bracts, long stem length, excellent vase life and is highly marketable. Literature indicates that this crop is suited for pot or bed production, but does not compare methods. This study assessed the impact of production system on final stem quality. Uniform rooted cuttings of `Renaissance Red' obtained from a commercial supplier were transplanted into 30.5-cm pots or a 1.2-× 2.4-m bed containing a soilless media to obtain 2 plants per 0.9 m2. A total of 56 cuttings were used for each production system and grown using standard production techniques. Transplanting occurred on 11 Aug. 11 2003 with plants reaching market stage, two cyathia shedding pollen, about 17 weeks later. To minimize border effects, plants in the outside rows of each production system were discarded. Thus, stem length, stem diameter, bract diameter, floral development, and number of axillary shoots were determined for 30 interior plants in each system. The production systems differentially impacted stem length and number of axillary shoots. Mean stem length in the bed system (89.7 cm) was greater than that observed in the pot system (71.4 cm). Plants in the bed system had significantly fewer axillary branches per plant (0.5) than plants in the pots (2.0). Stem diameters were similar for both systems (11.5 mm and 10.9 mm for bench and pot, respectively) as were bract diameters (14.3 cm and 13.4 cm for pot and bench, respectively). Both systems produced marketable stems; however, stems produced in the bed system had longer stems, fewer axillary branches, and were more uniform than those in the pot system.

Inheritance of Seed Set, Germination, and Day Neutrality/Heat Delay Insensitivity of Garden Chrysanthemums (Dendranthema ×grandiflora) under Glasshouse and Field Conditions

Commercial chrysanthemums are short day (SD) plants. Recently, several day neutral (DN) garden genotypes have been identified. Both glasshouse and garden cultivars vary in heat delay insensitivity (HDI). This research analyzed yield components (seed set, germination, yield potential) and tested a DN/HDI ideotype for its effectiveness. Progeny from a 6 × 6 diallel were embryo rescued, clonal ramats were grown in two environments (glasshouse—long days; field—long to short days) and evaluated for flowering, early flowering response groups, thermozero temperature response, low long day leaf number (LDLN), high leaf initiation rates, and low mean stem lengths of the terminal shoot. Self seed set ranged from 0% to 8% while outcross seed set was 0% to 92%. General and specific combining ability were highly significant for seed set, the reciprocals, and their interactions. Germination averaged 67%, while yield potential was 44%. Cotyledon pigmentation in embryo rescued seedlings was 7% albinos, 15% anthocyanin (transposable elements), and 78% normal (green). SD parents did not flower in either photoperiod although PPSL-10 carried alleles for DN. SD x DN crosses produced some DN progeny and fit a 1:3 chi square ratio (DN:SD), indicating DN to be recessive. However, DN x DN crosses also fit a 3:1 chi square ratio, due to HDI. No progeny flowered within the 3 to 6 week ideotype; visible bud date had a heritability of h2 = 0.50. Most progeny were within the LDLN range (h2 = 0.72). Several leaf initiation rates exceeded the ideotype (h2 = 0.003); plant height also matched the ideotype (h2 = 0.66). Both visible bud and flowering dates require significant improvement before progeny match the DN/HDI ideotype.

Growth analysis of nine multipurpose woody legumes native from southern Mexico

The growth of nine multipurpose woody legumes was evaluated in nursery conditions. These species, belonging to the genera Acacia, Leucaena, Lysiloma, Prosopis and Pithecellobium, inhabit both primary and secondary tropical deciduous and thorn forests. The total length of the experiments was 165 days. At a variable frequency, the following four variables were measured: (1) relative growth rate (RGR), (2) root/shoot ratio (R/S), (3) root length/root dry weight ratio (RL/RDW), and (4) stem length (SL). The temporal behavior of these variables differed greatly among species. A direct relationship between seed weight and initial biomass production was initially found; however, the effect of seed size on biomass production was lost as plants aged. At the initial harvest, RGR values did not differ significantly among species, but they did at the end of the experiment; Pithecellobium dulce had the lowest final RGR. The three Acacia species had the highest biomass productions and highest R/S ratios but the lowest RL/RDW ratios; A. farnesiana and Lysiloma divaricata had the largest mean SL, whereas the smallest mean SL corresponded to the two Leucaena species and to Lysiloma acapulcensis. Several recommendations concerning the management of plants in the nursery and the optimal timing for transplanting the seedlings to reforestation sites are provided.

Structural variation in current-year shoots of broad-leaved evergreen tree saplings under forest canopies in warm temperate Japan

Stem length and leaf area of current-year shoots were measured in saplings of eight broad-leaved evergreen tree species growing under a forest canopy. Stem length varied over a range of one to two orders of magnitude within each species. In all species, both the number of leaves and the mean stem length between successive leaves were greater in longer shoots. Mean leaf size and stem length were not correlated in six of eight species, and only weakly positively correlated in the other two species. Thus, total leaf area per stem increased with stem length, but not in direct proportion: leaf area per stem length was smaller in shoots with long stems and larger in shoots with short stems. I conclude that the within-species variation in the leaf-stem balance of current-year shoots is related to variation in shoot functional roles, as has been observed for long and short shoots in many deciduous tree species: shoots with long stems are extension oriented and contribute to the framework of the crown, whereas shoots with short stems serve mainly for leaf display. Among species, large differences were found in the leaf area per stem length ratio. In the species with larger leaf area per stem length ratios, leaves had narrower blades or longer petioles, or both, resulting in a reduction of mutual shading among the leaves on the shoot.

Growth and morphological responses of four helophyte species in an experimental water-depth gradient

The distribution on shorelines of four helophyte species (two gramineous species, viz. Phalaris arundinacea L. and Phragmites australis (Cav.) Trin. ex Steudel and two cyperacean species, viz. Scirpus maritimus L. and S. lacustris L.) was studied in relation to growth responses in the water-depth gradient. Stands of S. lacustris were found at lower depths relative to the mean water level (average fringe depth 69 ± 19 cm) than stands of Phragmites australis (av. 45 ± 20 cm), S. maritimus (av. 36 ± 8 cm) and Phalaris arundinacea (av. 25 ± 8 cm). The growth responses to a gradient of water depth were studied by planting the four species at five distinct water depths in outdoor basins, and determining morphological parameters and biomass distributions of the species grown for two consecutive years. The biomass of Phalaris arundinacea was reduced below 30 cm water depth, while Phragmites australis and S. maritimus showed reduced biomass at 80 cm water depth. S. lacustris showed no biomass reduction even at 80 cm water depth. An increased above-ground: below-ground biomass ratio in deeper water was demonstrated for each of the species under study; however, the modification of biomass distribution in the gramineous species occurred abruptly in very shallow water contrary to the cyperacean species. Mean basal stem diameter increased with water depth in all four species. Mean stem length increased with water depth in three of the four species. Stem elongation with increasing water depth was strongest in the cyperacean species. The gramineous species showed enhanced formation of adventitious roots at submerged nodes. The similarity of responses to water depth was greatest within each of the groups of gramineous and cyperacean species. The responses reflect the zonation of the species along the water-depth gradient: S. lacustris in relatively deep water, Phragmites australis and S. maritimus in shallower water, and Phalaris arundinacea in very shallow water.

Seed Source Affects Seedling Development and Nitrogen Fixation of Maackia amurensis

Abstract Seeds of Maackia amurensis Rupr. &amp; Maxim. were obtained from 38 sources, and 2,393 seedlings were examined for variation in plant growth and development. Mean stem length and number of leaves per plant after 21 months ranged from 10 to 40 cm (4 to 16 in) and from 6 to 13, respectively, among seedlings from different sources. The mean product of length and width of a representative leaflet was 362 to 1510 mm2 (0.6 to 2.3 in2) among sources. A subset of seven seed sources was used to determine how seedling growth, root nodulation, and N content of shoots are influenced by applied N and inoculation with Bradyrhizobium. Plants from the seven sources varied in nodule dry mass and shoot N. Mean stem length, laminar area, and dry mass of plants provided N and grown in uninoculated medium were higher than those of plants not provided N regardless of inoculation. When N was not provided, inoculation increased N in shoots but did not affect growth. Nodule dry mass of plants in inoculated medium was correlated positively with surface area of lamina. Variation among seedlings provides a basis for selecting genotypes that produce high nodule mass and grow rapidly.

PERFORMANCE OF `NELLIE WHITE' EASTER LILIES IN ROOT MEDIA CONTAINING COAL BOTTOM ASH

Easter lilies (Lilium longiflorum Thunb. `Nellie White') were forced in root media composed of 1 peat: 1 vermiculite (v/v) mixed with coal bottom ash (CBA) at rates of 0%, 25%, 50%, 75%, or 100% CBA. Lilies in all levels of CBA were equal in mean per plant flower bud numbers, fresh and dry weights, and numbers of yellow or brown lower stem leaves. Lilies in 100% CBA were significantly lower in mean stem length than plants in 0% or 50% CBA. Plants in 100% CBA required more frequent irrigation than plants in all other media. Media pH and solution electrical conductivity increased with increase in percent CBA. Analysis of leaf tissue showed no difference in nutrient levels between plants in 0% or 100% CBA.

Shoot morphological response to interactions betweenDactylis glomerataandVeronica persica

AbstractShoot morphological response to intra- and interspecific interactions between Dactylis glomerata L. and Veronica persica Poir. was examined in greenhouse experiments. We measured the shoot growth and morphology of one target plant for each species, surrounded by six conspecific (monoculture) or heterospecific (mixed culture) neighbours planted at different distances from the target plant. There were no significant effects of either species of neighbour or distance between plants on the above-ground dry mass of target plants, in both species. However, the mean stem length of D. glomerata targets was significantly greater in monoculture than in mixed culture, resulting in taller plants when they were set up with conspecific neighbours. V. persica targets showed a significant change in the coefficient of variation for the angles between terminal internodes and the soil surface, indicating the fact that this angle varied more in mixed culture than in monoculture. These findings suggest that the plasti...

LEAF, STEM, AND FLOWER CHARACTERISTICS OF ROSA HYBRIDA L. UNDER DIFFERENT CO2 CONCENTRATIONS

Two greenhouses received ambient CO2 and two were enriched between 1000 and 1200 ppm CO2 when vents were closed. Two-year-old Rosa hybrida L. `Royalty', `Emblem', and `Samantha' plants growing in each house were pinched 20 Oct. and 28 Dec. 1992 for Christmas and Valentine's Day crops. All temperature set points were 22C/17C day/night. At flowering, 5 shoots from each bench location were destructively sampled for stem diameter, stem length, and fresh and dry weights of stem, leaves, and flower bud.At flowering for the Christmas 1992 crop, shoots in the enriched houses tended to have larger stem, leaf, and flower fresh weights, and larger stem diameters. Analysis of variance found stem lengths of combined cultivars to be longer (p &lt; .05) in the CO2 enriched houses. Mean stem lengths were 68.8 cm and 63.9 cm for flower stems in CO2 enriched and ambient houses, respectively. Dry weight data from the Christmas crop, and results from the 1993 Valentine's crop will be presented.