Reduced Stem Length Research Articles

WAKL8 Regulates Arabidopsis Stem Secondary Wall Development.

Wall-associated kinases/kinase-likes (WAKs/WAKLs) are plant cell surface sensors. A variety of studies have revealed the important functions of WAKs/WAKLs in regulating cell expansion and defense in cells with primary cell walls. Less is known about their roles during the development of the secondary cell walls (SCWs) that are present in xylem vessel (XV) and interfascicular fiber (IF) cells. In this study, we used RNA-seq data to screen Arabidopsis thaliana WAKs/WAKLs members that may be involved in SCW development and identified WAKL8 as a candidate. We obtained T-DNA insertion mutants wakl8-1 (inserted at the promoter region) and wakl8-2 (inserted at the first exon) and compared the phenotypes to wild-type (WT) plants. Decreased WAKL8 transcript levels in stems were found in the wakl8-2 mutant plants, and the phenotypes observed included reduced stem length and thinner walls in XV and IFs compared with those in the WT plants. Cell wall analysis showed no significant changes in the crystalline cellulose or lignin content in mutant stems compared with those in the WT. We found that WAKL8 had alternative spliced versions predicted to have only extracellular regions, which may interfere with the function of the full-length version of WAKL8. Our results suggest WAKL8 can regulate SCW thickening in Arabidopsis stems.

Total Hip Arthroplasty Performed with a Novel Design Type 1 Femoral Stem: A Retrospective Minimum 5-Year Follow-up Study.

BackgroundThe Bencox M stem is a mid-short type 1 stem with additional unique design features. It has a reduced stem length and a lateral shoulder to facilitate minimally invasive surgery, as well as an angular lateral shoulder and a trapezoidal neck to minimize stem-liner impingement. There have been many mid-term reports on type 1 stems, but no results have been reported so far on this novel design type 1 femoral stem. This study presents the clinical and radiological outcomes of total hip arthroplasty performed with the M stem after a minimum 5-year follow-up.MethodsFrom July 2014 to February 2015, 125 primary total hip arthroplasties using the M cementless femoral stem were performed on 112 patients in our hospital. Among them, 94 patients (106 hips) were eligible for the study and were followed up for more than 5 years. Our primary outcome was clinical results, which were evaluated by the Harris Hip Score (HHS), thigh pain, noise, and other complications. Secondary outcome was radiological outcomes. Seventy-seven hips were evaluated radiologically with attention to implant fixation, migration, loosening of component, degree of stress shielding, radiolucent lines, focal osteolysis, heterotopic ossification, and the evidence of impingement between the stem and liner.ResultsThe average HHS improved from 54.6 points (range, 24–67 points) to 96.8 points (range, 91–100 points) at the latest follow-up. Three hips (2.8%) had intermittent thigh pain, which was tolerable without medication. Five hips (4.7%) had ceramic-related noise. There were no other complications such as infection, nerve injury, dislocation, or revision. All implants showed radiographic evidence of stable fixation by bone ingrowth without migration. Fifty-seven hips (74%) showed mild femoral stress shielding. Distal cortical hypertrophy was detected in 7 hips (9%), and heterotopic ossification was observed in 17 hips (22%). No implant demonstrated focal osteolysis and notching of the femoral neck or shoulder on radiographs.ConclusionsThe minimum 5-year results of total hip arthroplasty performed with the M cementless femoral stem were encouraging clinically and radiologically. A long-term follow-up will be necessary to evaluate its longevity.

Effects of low and high red to far-red light ratio on tomato plant morphology and performance of four arthropod herbivores

Changing the spectral composition of light has numerous advantages for the production and quality of horticultural crops. However, changing the light spectrum to stimulate growth can have negative consequences for plant responses to biotic stress. Especially changes in the ratio between red and far-red light (R:FR) have an important effect on plant-herbivore interactions. A low R:FR is indicative of shading and competition for light and induces strong growth responses which are known as shade avoidance responses, including stem elongation and leaf hyponasty. Exposure to low R:FR also inhibits plant defensive responses against biotic agents and increases the performance of pests and pathogens. In this study we tested whether an increase in R:FR, through the supplementation of red light LEDs can be used to reduce the performance of arthropod herbivores. Tomato plants (Solanum lycopersocum) were exposed to three different R:FR ratios; 0.5 (shading), 1.2 (sunlight) and 5.2 (artificial) and infested with either caterpillars (Manduca sexta), spider mites (Tetranychus urticae), aphids (Myzus persicae) or whiteflies (Trialeurodes vaporariorum). Plants exposed to a low R:FR showed clear stem elongation and leaf hyponasty consistent with the shade-avoidance responses, while plants exposed to high R:FR showed reduced stem length and reduced hyponasty. The performance of all four herbivore species was significantly increased after exposure to low R:FR, although the strength of this effect varied between phloem feeding and tissue feeding herbivores. Increasing the R:FR only reduced the performance of the caterpillars and did not significantly affect the other herbivore species. These results indicate that herbivore species with different feeding strategies respond differently to changes in light quality. These findings have implications for the use of LEDs in greenhouse horticulture.

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We identified the phytochemicals in Withania somnifera L, a multipurpose medicinal plant of the Himalayan región using TLC, FTIR and HPLC. Eleven formulations were made by mixing in different ratios of Withania leaf extract, wood ash and distilled wáter. Wood chips and twigs of 3-years old Pinus roxburghii tree were completely burnt till ashes was used as Wood ash. The 11-formulationss were i.e. formulation I (Withania leaf extract 100%)), formulation II (75:25 concentration (Withania leaf extract: Distilled water)), formulation III (50:50 concentration (Withania leaf extract: Distilled water), formulation IV (25:75 concentration (Withania leaf extract: Distilled water)), formulation V (75:25 concentration (Withania leaf extract: Wood ash)), formulation VI (50:50 concentration (Withania leaf extract: Wood ash)), formulation VII (25:75concentration (Withania leaf extract: Wood ash)), formulation VIII (Wood ash 100%)), formulation IX (75:25 concentration (Wood ash: Distilled water)), formulation X (50:50 concentration (Wood ash:Distilled water)), formulation XI (25:75concentration (Wood ash: Distilled water)). The herbicidal activity of formulations was earlier studied against Cannabis sativa L. (banned narcotic plant). Their herbicidal activity was tested on seeds germination and seedlings growth of Cannabis sativa L weed and 2 crops: Hordeum vulgare L and Cicer arietinum L. In Pot culture, the formulation V spray caused maximum reduction in root length of Cannabis (53 %) > Hordeum (23 %) and Cicer (22 %) than control. The formulations were also tested on crops for their herbicidal effects. In Petri plate bioassy, the formulation V (75:25 concentration (Withania leaf extract: Wood ash) showed maximum reduction in seed germination and seedling growth of C. sativa weed, but had little effect on growth of test crops. The reduction in stem length was maximum (55 %) in Cannabis > Hordeum (20 %) > Cicer (19 %) than control. Glyphosate decreased the stem length of Cicer (80 %) > Hordeum (58 %) and Cannabis (16 %) over control. While the reduction in root length was in Cicer (75 %) > Hordeum (73 %) > Cannabis (18 %) than control. The root and stem extract formulations were more phytotoxic to Cannabis sativa. Formulation V (75:25 concentrations (Withania leaf extract: wood ash)) reduced the number of leaves, number of shoot, root branches and stem and root length of Cannabis sativa.

Effect of water stress induced by polyethylene glycol 6000 on the somatic embryos conversion into whole plantlets in cocoa (Theobroma cacao L.)

Rainfall scarcity due to climate change is a major constraint that limits cocoa productivity in Côte d'Ivoire. This work aims to regenerate cocoa plants tolerant to water stress using in vitro methods. Staminode and petal explants of the genotypes C1, C9, C14, C15, C16, C18 and C20 were used to produce somatic embryos through two methods. Firstly, somatic embryos were induced under stressfull conditions on media containing different concentrations of polyethylene glycol (PEG) 6000 (0; 25; 50; 75; 100 and 125 g/l) and secondly; under non-stressed conditions. Somatic embryos were placed on a conversion medium in the same stress condition. The number of regenerants decreased with the increase in the concentration of PEG with all genotypes. Only genotypes C1 and C15 regenerated plantlets under water stress conditions. The sensitive genotypes C9, C14, C16, C18 and C20 have not developed plantlets on media containing PEG. The plantlets produced under water deficit conditions exhibited a reduction in stem length and leaves number and an increase in length or offset of the high number of roots. The survival rate of regenerants during acclimatization was higher on the sandsubstrate. The selected genotypes could be used in an improvement program of cocoa production.Keywords: Climate change; plant regeneration; genotype; tolerance; drought; in vitro

Fasciclin-Like Arabinogalactan-Protein 16 (FLA16) Is Required for Stem Development in Arabidopsis.

The predominant Fascilin 1 (FAS1)-containing proteins in plants belong to the Fasciclin-Like Arabinogalactan-protein (FLA) family of extracellular glycoproteins. In addition to FAS1 domains, these multi-domain FLA proteins contain glycomotif regions predicted to direct addition of large arabinogalactan (AG) glycans and many contain signal sequences for addition of a glycosylphosphatidylinositol (GPI)-anchor to tether them to the plasma membrane. FLAs are proposed to play both structural and signaling functions by forming a range of interactions in the plant extracellular matrix, similar to FAS1-containing proteins in animals. FLA group B members contain two FAS1 domains and are not predicted to be GPI-anchored. None of the group B members have been functionally characterized or their sub-cellular location resolved, limiting understanding of their function. We investigated the group B FLA16 in Arabidopsis that is predominantly expressed in inflorescence tissues. FLA16 is the most highly expressed FLA in the stem after Group A members FLA11 and FLA12 that are stem specific. A FLA16-YFP fusion protein driven by the endogenous putative FLA16 promoter in wild type background showed expression in cells with secondary cell walls, and FLA16 displayed characteristics of cell wall glycoproteins with moderate glycosylation. Investigation of a fla16 mutant showed loss of FLA16 leads to reduced stem length and altered biomechanical properties, likely as a result of reduced levels of cellulose. Immuno-labeling indicated support for FLA16 location to the plasma-membrane and (apoplastic) cell wall of interfascicular stem fiber cells. Together these results indicate FLA16, a two-FAS1 domain FLAs, plays a role in plant secondary cell wall synthesis and function.

Phytohormone responses in pepper (Capsicum annuum L.) leaves under a high density of aphid infestation.

The time course response of selected phytohormones has been evaluated in sweet pepper plants (Capsicum annuum L.) submitted to a high density (200 aphids/plant) of aphid (Myzus persicae Sulzer) infestation. Abscisic acid (ABA), salicylic acid (SA), indole-3-acetic acid (IAA), and jasmonates (JAs), including jasmonic acid (JA), jasmonoyl-l-isoleucine (JA-Ile), and cis-OPDA have been simultaneously identified and quantitated by UHPLC-MS/MS in pepper leaf tissue harvested at 3, 8 hours post-infestation (hpi), 1, 2, 4 and 7 days post-infestation (dpi). Infested plants showed a reduction in stem length at 7 dpi and in the number of leaves and leaf width from 4 dpi onwards. JA and JA-Ile significantly increased very early (from 3 hpi) while SA only accumulated at 7 dpi. Despite the high density of infestation, the aphid-induced accumulation of JAs was much lower than the burst typically induced by chewing herbivores. On the other side, ABA peaked in aphid-infested plants at 2 and 4 dpi, while IAA content did not change significantly at any time point. Growth inhibition may be partially explained by the high levels of JAs found in aphid-infested plants. The possibility that the obtained results support the hypothesis of the aphid manipulation of plant metabolism is discussed.

The effect of short-stem humeral component sizing on humeral bone stress

Several humeral stem design modifications for shoulder arthroplasty, including reduced stem length, changes to metaphyseal geometry, and alterations to implant surface texture, have been introduced to reduce stress shielding. However, the effect of changes in the diametral size of short-stem humeral components remains poorly understood. The purpose of this finite element study was to quantify the effect of varying the size of short-stem humeral components on the changes in bone stress from the intact state to the reconstructed state. Three-dimensional models of 8 male cadaveric humeri (mean age, 68 ± 6 years; all left-sided humeri) were constructed from computed tomographydata using Mimics software. Each humerus was then reconstructed with 2 short-stem components (Exactech Preserve), one having a larger diametral size (SH+) and one having a smaller diametral size (SH-). Modeling was conducted for loading states consistent with 45° and 75° of abduction, and the resulting changes in bone stress compared with the intact state and the expected bone response were determined. The smaller (SH-) short-stem implant produced humeral cortical and trabecular bone stresses that were closer to the intact state than the larger (SH+) short-stem implant at several locations beneath the humeral head resection (P ≤ .032). A similar trend was observed for expected bone response, where the smaller (SH-) short-stem implant had a smaller proportion of bone that was expected to resorb following reconstruction compared with the larger (SH+) short-stem implant for several slice depths in the medial quadrant (P ≤ .02). These findings may indicate that smaller short-stem components are favorable in terms of stress shielding.

Physiological and Structural Modifications in Snail Medic (Medicago scutellata L.) Plants Exposed to Salinity

Seeds of snail medic (Medicago scutellata L.) were assessed for their response to salt at the germination and seedling stages. NaCl at concentrations 86 and 170 mM decreased the final germination percentage. Embryonic axis length, water content and dry weight of embryonic axis and cotyledons were also reduced by salt treatment. Furthermore, 28-d-old plants were grown hydroponically with different NaCl concentrations (0, 86 and 170 mM). After 7 days of treatment, growth, water content and development of the different organs of M. scutellata plant were affected especially at the highest NaCl concentration (170 mM). However, NaCl did not affect root length and the number of stem shoots but reduced stem length and total leaf area. Salt treatment increased markedly the concentration of Na+ in leaf and root tissues while reduced that of K+ only in root and stem tissues. Lipid peroxidation revealed the damage of the membranes of roots and leaves. Moreover, showed a more intense suberization and lignification at the cambial zone of roots of M. scutellata, were observed under the effect of NaCl.

Fine Mapping of the brachytic Locus on the Tomato Genome

Mechanization of farm work is increasingly demanded for the current system of fresh-market tomato (Solanum lycopersicum) production. One essential element for the adoption of mechanical harvest of fresh-market tomatoes is modification of plant architecture so that the crop can be grown without staking. To address this in the current production system, the stem length should be reduced. The tomato brachytic (br) locus has been shown to be a primary source of reducing stem length. To improve the effectiveness of marker-assisted selection (MAS) for the br-mediated trait and to provide resources for cloning this gene, we fine-mapped br to the tomato genome. Fine mapping of br to chromosome 1 was initiated by a survey of genome-wide single-nucleotide polymorphisms (SNPs) shown to be polymorphic between the br phenotype and normal using the tomato array, identifying the interval that harbors br. Genetic markers that flank the locus further permitted saturation of the interval. Twenty-six fixed homozygous recombinant lines were identified together in two different populations and tested with those markers. These efforts resulted in the first report that the br is fine-mapped to a 763-kb physical interval of tomato reference genome. The identified markers close to the br in the present study will be significant resources for MAS and gene cloning research.

Total Hip Intraoperative Femur Fracture: Do the Design Enhancements of a Second-Generation Tapered-Wedge Stem Reduce the Incidence?

BackgroundIntraoperative femur fracture (IFF) is a well-known complication in primary uncemented total hip arthroplasty (THA). Variations in implant instrumentation design and operative technique may influence the risk of IFF. This study investigates IFF between a standard uncemented tapered-wedge femoral stem and its second-generation successor with the following design changes: size-specific medial curvature, proportional incremental stem growth, modest reduction in stem length, and distal lateral relief. MethodsA single experienced surgeon's patient database was retrospectively queried for IFF occurring during primary uncemented THA using a standard tapered-wedge femoral stem system or a second-generation stem. All procedures were performed using soft tissue preserving anatomic capsule repair and posterior approach. The primary outcome measure was IFF. A z-test of proportions was performed to determine significant difference between the 2 stems with respect to IFF. Patient demographics, Dorr classification, and implant characteristics were also examined. ResultsForty-one of 1510 patients (2.72%) who received a standard tapered-wedge femoral stem sustained an IFF, whereas 5 of 800 patients (0.63%) using the second-generation stem incurred an IFF. No other significant associations were found. ConclusionA standard tapered-wedge femoral stem instrumentation system resulted in greater than 4 times higher incidence of IFF than its second-generation successor used for primary uncemented THA. Identifying risk factors for IFF is necessary to facilitate implant system improvements and thus maximize patient outcomes.

Thigmomorphogenesis: changes in morphology, biochemistry, and levels of transcription in response to mechanical stress inAcacia koa

Acacia koa A. Gray, an economically important timber-wood tree growing in the Hawaiian Islands, is affected by many environmental stresses, including drought, strong wind, heavy rain, and infection by fungal pathogens. Previous studies have shown that some morphological and biochemical changes that take place as a result of environmental stresses in plants can be also induced by mechanical stresses such as touching and bending. We studied morphological and biochemical changes and levels of gene transcription in A. koa plants due to mechanical stress. For a mechanical stress treatment, A. koa seedlings were gently bent in four cardinal directions daily for 2–6 months, after which morphological and biochemical changes were quantified. The stressed A. koa had significantly increased stem diameter, number of xylem cells, and anthocyanin and lignin contents and significantly reduced stem length. The gene expression analyses showed that 53 genes, including the genes for calcium signaling, ethylene biosynthesis, abscisic acid degradation, stress-related transcriptional regulation, and disease resistance, were induced more than twofold within 10–60 min following mechanical stress. The observation that the genes for disease resistance such as NBS-LRR can be induced by mechanical stress suggests that strong wind and rain in the natural forest may also induce disease resistance in trees.

Characterization of Transgenic Kalanchoë and Petunia with Organ-Specific Expression of GUS or GA 2 ox Genes Led by the Deletion BOX-I Version (dBI) of the PAL1 Promoter

In the present work, transgenic Kalanchoe blossfeldiana and Petunia hybrida with overexpression of Nicotiana GA 2 ox inserted in pCAMBIA1303 T-DNA are investigated. To avoid possible adverse effects of constitutive overexpression a modified Pisum PAL1 promoter was used, in which the BOX-I AC-rich motif had been deleted (dBI—deletion BOX-I). To investigate the tissue-specificity of the dBI and PAL1 promoters, their sequences were fused with the GUS gene, cloned into two types of vectors (pCAMBIA1303 and p6N) and introduced by Agrobacterium-mediated transformation into both species. GUS-transgenic lines were tested for the GUS mRNA in stems, leaves, and roots with the use of RT-PCR and GUS-stained tissues were visualized and compared with the use of light microscopy. The dBI promoter leads to expression of GUS mRNA and GUS activity in stems and petioles but not in roots or leaves, whereas the PAL1 promoter is less specific. All transgenic lines were tested for transgene copy number using Southern blot analysis. Transgenic Kalanchoe plants with Nicotiana GA 2 ox exhibited more than twofold reduction in stem length but no reduction of the number of internodes. Similarly, in Petunia transgenic plants, the stem length was reduced threefold. The leaves of the transgenic Kalanchoe plants were smaller, as convex as those of the youngest leaves of the non-transgenic control plants, and had reduced petiole length. The leaves from transgenic Petunia plants were similar in shape to those of the non-transgenic control plants but significantly smaller.

Characterization of Femoral Component Initial Stability and Cortical Strain in a Reduced Stem-Length Design

BackgroundShort-stemmed femoral components facilitate reduced exposure surgical techniques while preserving native bone. A clinically successful stem should ideally reduce risk for stress shielding while maintaining adequate primary stability for biological fixation. We asked (1) how stem-length changes cortical strain distribution in the proximal femur in a fit-and-fill geometry and (2) if short-stemmed components exhibit primary stability on par with clinically successful designs. MethodsCortical strain was assessed via digital image correlation in composite femurs implanted with long, medium, and short metaphyseal fit-and-fill stem designs in a single-leg stance loading model. Strain was compared to a loaded, unimplanted femur. Bone-implant micromotion was then compared with reduced lateral shoulder short stem and short tapered-wedge designs in cyclic axial and torsional testing. ResultsFemurs implanted with short-stemmed components exhibited cortical strain response most closely matching that of the intact femur model, theoretically reducing the potential for proximal stress shielding. In micromotion testing, no difference in primary stability was observed as a function of reduced stem length within the same component design. ConclusionOur findings demonstrate that within this fit-and-fill stem design, reduction in stem length improved proximal cortical strain distribution and maintained axial and torsional stability on par with other stem designs in a composite femur model. Short-stemmed implants may accommodate less invasive surgical techniques while facilitating more physiological femoral loading without sacrificing primary implant stability.

Physiological responses of two tomato (Lycopersicun esculentum M.) cultivars to Azomite fertilizer under drought stress.

This study was conducted in order to investigate the effect of drought stress and Azomite fertilizer on some physiological traits of two tomato (Lycopersicon esculentum M.) cultivars (izmir and Izabella). A randomized complete design with factorial arrangement with three replications was used. Treatments consisted of three levels of irrigation including FC (control), FC (mild drought stress), and FC (severe drought stress)] along with four levels of Azomite (0,‌ 25, ‌50 and 100g/pot). Results showed that drought stress reduced stem length, plant dry and fresh biomass, relative growth rate (RGR), net assimilation rate (NAR), relative water content (RWC), total chlorophyll, carotenoid, nitrogen, phosphorus and potassium in leaves. Azomite fertilizer increased the stem length, plant dry and fresh biomass, RGR, NAR, RWC, total chlorophyll, carotenoid, nitrogen, phosphorus, and potassium in leaves in comparison with control plants in both cultivars. Interaction effect of drought stress and Azomite had a significant effect on increasing plant fresh biomass, RGR, NAR, RWC, total chlorophyll, carotenoid, nitrogen, phosphorus, and potassium. Interaction effect of drought stress and cultivar showed significant effect on increasing plant fresh biomass, NAR, RWC, total chlorophyll, and phosphorus. Moreover, the results indicated that the interaction effect of Azomite and cultivar had a significant effect on plant fresh biomass, RGR, RWC, and phosphorus in leaves. In general, Azomite was effective on drought stress tolerance of tomato plant.

EFFECT OF SOME GROWTH RETARDANTS ON GROWTH AND FLOWERING OF HELIANTHUS ANNUUS L. CV. SUNRICH ORANGE SUMMER 981V PLANTS A- EFFECT OF FOLIAR SPRAY TREATMENTS WITH ANCYMIDOL, DAMINOZIDE AND ETHEPHON

Pot experiments were carried out at the nursery of Hort. Res. Inst, Giza, Egypt throughout the two successive seasons of 2014 and 2015. The work embodied in this paper was to study the influence of some growth regulators (daminozide, ancymidol and ethephon) on sunflower (Helianthus annuus L. cv. Sunrich Orange Summer 981V) plant for achieving the hope of producing dwarf plant of good quality, suitable for using as a pot plant. Results indicated that most treatments reduced stem length of the treated plants with the superiority of 2450 ppm daminozide treatment which induced 50% reduction in such trait, compared to the control plants in the two seasons. However, stem diameter and number of internodes/stem were improved in response to all the used treatments. Internode length, stem fresh and dry weights were decreased with few exceptions, but the greatest decrease in these criteria was attained by daminozide treatment at any rate and ethephon one at 250 ppm. Number of leaves/plant were increased by the various treatments. Root length increased over control with few exceptions in both seasons. However, the highest averages in most measurements were achieved by ancymidol, especially at 20 ppm level. A significant flowering earliness in the two seasons was noticed in plants sprayed with ethephon at 250 ppm. The least number of days from flower bud appearance to opening was obtained by the 20 ppm ancymidol treatment, but the plants treated with the other treatments took longer time to anthesis. Ethephon treatments elevated the mean number of lateral buds/stem to the maximum, while ancymidol ones gave the largest flower heads. Number of ray flowers/head, disc diameter and flower head fresh and dry weights were improved due to most treatments. Content of photosynthetic pigments were slightly improved with few exceptions. Total phenols content reached the maximum by ancymidol treatments, followed by the ethephon ones. However, total indoles content was not affected by most of the used treatments. In addition, the percent of total soluble sugars was increased by ancymidol at 5 ppm, daminozide at 2450 ppm and ethephon at 500 ppm treatments, while other treatments declined it. On the other hand, the percent of N, P and K was generally decreased in response to the various treatments, with few exceptions as compared to control.

Comparison of proximal humeral bone stresses between stemless, short stem, and standard stem length: a finite element analysis

The stem lengths of humeral components used in shoulder arthroplasty vary; however, the literature on these devices is limited. This finite element study investigates the effect of humeral component length on stresses in the proximal humerus. Intact and 3 reconstructed (standard length, short, and stemless implants) finite element models were created from shoulder computed tomography scan data (N = 5). Loading was simulated at varying abduction angles (15°, 45°, and 75°). The average bone stress (represented as a percentage of intact values) was reported at 8 transverse slices. In addition, the overall average change in cortical and trabecular bone stresses was quantified. Cortical bone stresses in the most proximal slice for the standard (58% ± 12%) and short (78% ± 10%) stem models were significantly reduced compared with the intact (100%) and stemless (101% ± 6%) models (P = .005). These reductions persisted in the second cortical slice for the standard stem compared with the intact, stemless, and short models (P = .025). Interestingly, stresses in the trabecular bone within these proximal slices were significantly elevated when stemless implants were used compared with all other implants (P < .001), regardless of abduction angle. Reducing stem length produced humeral stresses that more closely matched the intact stress distribution in proximal cortical bone. Opposing trends presented in the proximal trabecular bone, probably because of differences in load transfer when shorter stems are used. Accordingly, the results suggest that implant stem length is 1 variable that can be modified in an attempt to better mimic intact bone stresses during humeral component insertion, provided stem fixation is adequate.

The Effect of Paclobutrazol Application Time and Variety on Growth, Yield, and Quality of Potato (Solanum tuberosumL.)

An experiment was set up to investigate the effect of time of paclobutrazol application and variety on growth, yield, and quality of potato in a greenhouse at 34°C (±3) and 21°C (±3) day and night temperatures, respectively, with 60% relative humidity. The experiment was set up as a 2 × 4 factorial design in a CRD with 3 replications. The first factor was potato variety and the levels were BP1 and Diamond. The second factor was paclobutrazol application time and the levels were 28 (Days After Planting) DAP, 35 DAP, and 42 DAP and no paclobutrazol applied (control). Early application of paclobutrazol reduced stem length, number of tubers per plant, and sugar content of potato; furthermore, it increased starch content and yield compared to late application and no paclobutrazol treatments. Early application of paclobutrazol at 28 DAP is recommended in high temperature zones as it increased the yield by 108% and quality of potato.

Trade-off between stress shielding and initial stability on an anatomical cementless stem shortening: in-vitro biomechanical study

Shortened cementless femoral stems have become popular with the advent of minimally invasive total hip arthroplasty (THA). Successful THA requires initial stem stability and prevention of stress shielding-mediated bone loss, although the effect of stem shortening is controversial. Here we experimentally examined whether stem shortening affects stress shielding and initial stability. Anatomical stems (length, 120 mm) were cut to an 80 mm or 50 mm length. Ten tri-axial strain gauges measured the cortical strain on each stem-implanted femur to evaluate stress shielding. Two transducers measured axial relative displacement and rotation under single-leg stance loading. The 50 mm stem increased the equivalent strains with respect to the original stem in the proximal calcar region (31.0% relative to intact strain), proximal medial region (63.1%), and proximal lateral region (53.9%). In contrast, axial displacement and rotation increased with a decreasing stem length. However, the axial displacement of the 50 mm stem was below a critical value of 150 µm for bone ingrowth. Our findings indicate that, with regard to a reduction in stem length, there is a tradeoff between stress shielding and initial stability. Shortening the stem up to 50 mm can promote proximal load transfer, but bone loss would be inevitable, even with sufficient initial stability for long-term fixation.

Stem morphology and vascular anatomy of Fagopyrum esculentum Moench. under retardant chlormequat chloride action

Effects of different concentrations of retardant chlormequat chloride on hypocotyl and first internode lengths of common buckwheat (Fagopyrum esculentum Moench.) were investigated. It was established that treatment of buckwheat plants with chlormequat chloride before presowing led to: reduction of stem length, activation of early and intensive lignification of vascular and mechanical elements, increasing number and size of vascular bundles in correlation with functional reconstructions on donor-acceptor connections of plant organs.