Subsequent Growth Period Research Articles

Mechanisms Underlying the Differential Sensitivity to Mesotrione in Sweet Corn

Mesotrione is a widely used post-emergence herbicide for maize. The toxicity of mesotrione to maize (especially sweet corn) has been widely reported, and some sweet corn varieties are highly sensitive to mesotrione, which affects subsequent plant growth periods. However, the molecular mechanisms responsible for the differences in susceptibility to mesotrione are not known. By comparing changes in the transcriptome of mesotrione-tolerant line 301 and mesotrione-sensitive line 276 after mesotrione treatment, we found that the genes coding light-harvesting chlorophyll protein complex were induced in 301, and the genes coding loosening cell walls were overrepresented in 276. The net photosynthetic rate, maximum photochemical efficiency of leaf PSII, photochemical quenching of chlorophyll fluorescence, and the electron transport rate were significantly higher in 301 than in 276 after mesotrione treatment, and these effects became more severe as time passed. In addition, oxidative balance was also affected by mesotrione. Compared with 301, SOD, POD, and CAT activities were significantly reduced with longer exposure time in 276. The results suggested that sweet corn can mitigate herbicide mesotrione toxicity by improving photosynthesis, ROS scavenging, and cell wall synthesis.

Cannabis Retail Market Indicators in Five Legal States in the United States: A Public Health Perspective

Adult-use cannabis markets are operating in multiple US states and abroad. Sales and licensing data for alcohol and tobacco are often used to understand consumption patterns and evaluate policy changes. Cannabis market data may provide similar insights, although these newly legal markets are complex and evolving, and the state data structures can differ. This study describes variations in market indicators and discusses the utility of cannabis market metrics from a public health perspective. We collected data from 5 early-adopting adult-use cannabis states: Alaska, Colorado, Massachusetts, Oregon, and Washington. Analyses focused on licensed retail outlets and retail sales revenues (pretax). Monthly data were collected from the opening of each state's adult-use market through June 2022. Joinpoint software was used to assess state trends and identify points of inflection in trends. Average sales per retailer for June 2019 and June 2022 were compared. Also described are retailers and revenue per population for 2022. All states showed 4 distinct periods of growth in retail licensee numbers. The greatest increases typically occurred in the first 3 to 4 months. Growth rates slowed to <1% per month for Colorado, Oregon, and Washington at months 25, 24, and 34, respectively. The number of cannabis retailers per 100,000 residents in June 2022 ranged widely, from 16.8 in Oregon to 3.0 in Massachusetts. Colorado, Oregon, and Washington each showed 4 distinct trend periods in adult-use retail sales: early rapid growth lasting <1 year, subsequent varied growth periods, and then declining sales in the most recent months, following early coronavirus disease 2019 period increases. Sales in Alaska and Massachusetts displayed more stable, consistent growth patterns. Sales per state resident for July 2021 to June 2022 also ranged widely, from $382.97 in Alaska to $180.94 in Washington. We found some consistencies and some variations in both point-in-time measures and trends in states' adult-use cannabis markets. Differences may relate to varied state policies and general contexts (eg, economies). Market data can be useful for public health monitoring, including understanding the effects of policies intended to protect health and safety. States providing publicly accessible cannabis market data create opportunities for such use. Our results underscore the importance of considering individual state regulatory frameworks and implementation timelines in studies of cannabis legalization.

Exogenous application of coronatine and alginate oligosaccharide to maize seedlings enhanced drought tolerance at seedling and reproductive stages

Plant growth regulators (PGRs) play crucial roles in maize drought tolerance. However, most of the studies are focused on seedling stage under greenhouse conditions, little is known on the effects of grain yields at later growth stage under field environment. It is hypothesized that exogenous application of PGRs can increase maize drought tolerance at different growth stages under field conditions. Here we used alginate oligosaccharide (AOS) and coronatine (COR) to investigate the effects of these two PGRs on maize drought tolerance in a two-year field experiment. The results showed that both COR and AOS treatments reduced leaf water loss and significantly increased the relative leaf water content by 12.6% and 13.0%, thus significantly decreasing superoxide anion accumulation by 49% and 42% in maize seedlings. There was no big difference between these two treatments in the seedling stage. In the subsequent reproductive growth period, although both COR and AOS treatments significantly increased leaf photosynthesis and above-ground growth, including photosynthetic rate by 41% and 33%, relative chlorophyll content (SPAD value) by 8.0% and 6.5%, leaf area by 22% and 15%, plant height by 8.3% and 5.9%, dry matter accumulation by 23% and 17%, respectively, under drought conditions, the effect of COR was superior to the AOS, as evidenced by membership function values of COR treatment were 0.12 and 0.08 larger than that of AOS treatment in 2020 and 2021, respectively. Ultimately, COR and AOS treatments significantly increased the grain yields by 21.7% and 16.2% in 2020, 22.3% and 15.7% in 2021, respectively, under drought conditions. Path analysis showed both PGRs increased final grain yields by increasing thousand-kernel weight (TKW). While the TKW increase with COR treatment was mainly due to the increase of relative chlorophyll content (SPAD value), AOS treatment mainly increased dry matter accumulation under drought conditions.

In−situ measurements of dendrite tip shape selection in a metallic alloy

The size and shape of the primary dendrite tips determine the principal length scale of the microstructure evolving during solidification of alloys. In-situ X-ray measurements of the tip shape in metals have been unsuccessful so far due to insufficient spatial resolution or high image noise. To overcome these limitations, high-resolution synchrotron radiography and advanced image processing techniques are applied to a thin sample of a solidifying Ga-35wt.%In alloy. Quantitative in-situ measurements are performed of the growth of dendrite tips during the fast initial transient and the subsequent steady growth period, with tip velocities ranging over almost two orders of magnitude. The value of the dendrite tip shape selection parameter is found to be $\sigma^* = 0.0768$, which suggests an interface energy anisotropy of $\varepsilon_4 = 0.015$ for the present Ga-In alloy. The non-axisymmetric dendrite tip shape amplitude coefficient is measured to be $A_4 \approx 0.004$, which is in excellent agreement with the universal value previously established for dendrites.

Get up early: Revealing behavioral responses of sandeel to ocean warming using commercial catch data.

Warming of the oceans and shifts in the timing of annual key events are likely to cause behavioral changes in species showing a high degree of site fidelity. While this is well studied in terrestrial systems, there are fewer examples from the marine environment. Sandeel (Ammodytes marinus) is a small eel‐shaped teleost fish with strong behavioral attachment to sandy habitats in which they are buried from late summer through winter. When spring arrives, the sandeel emerge to feed during the day for several of months before returning to the sand for overwintering refuge.Using fisheries data from the North Sea, we investigated whether catch rates reflect the timing of emergence and if seasonal patterns are related to temperature and primary production.Catch per unit effort (CPUE) was used to describe sandeel emergence. We developed indicators of the relative timing of the emergence from the winter sand refuge and the subsequent growth period. Different modeling approaches were used to investigate the relationship with bottom temperature and primary production.Variation in emergence behavior was correlated with variation in sea bottom temperature. Warmer years were characterized by earlier emergence. Significant warming over the last three decades was evident in all sandeel habitats in the North Sea throughout most of their adult life history, though no net shift in the phenology of emergence was detected. Minimum temperature during spring was a better predictor of emergence behavior than, for example, degree days.This study emphasizes how temperature‐induced changes in behavior may have implications for predators and fisheries of sandeel. The method can be applied to other species for which the timing of exploitation (i.e., fisheries) and species life history are well matched.

Perspectives on Drought Preconditioning Treatments With a Case Study Using Western Larch.

As the demand for drought hardy tree seedlings rises alongside global temperatures, there is a need to optimize nursery drought preconditioning methods to improve field performance of planted seedlings. This perspective article advocates for a more holistic approach to drought preconditioning research that considers the moderating role of plant developmental stage on the effects of drought preconditioning. We identify discrepancies in past studies of root growth potential (RGP) responses to drought preconditioning and highlight studies that suggest such discrepancies may result from inconsistencies among studies in the timing of drought preconditioning implementation. We then illustrate our perspective by presenting original research from an aeroponic RGP trial of 1st-year western larch (Larix occidentalis Nutt.) seedlings exposed to three soil moisture contents for 6months. We evaluated whether drought preconditioning could be used to increase the ratio of root: foliar tissue mass or enhance seedling physiological vigor during a subsequent growth period. Drought preconditioning was found to increase the ratio of root: foliar tissue mass and enhance seedling physiological vigor. Specifically, soil moisture content related negatively with new root biomass, positively with new foliar biomass, and negatively with the length and number of new roots (p<0.001). Meanwhile, the mass of lateral root production following drought preconditioning, but prior to aeroponic growth, correlated weakly to the mass, count, and length of new roots produced during aeroponic growth. We propose that evaluating the importance of the timing of drought preconditioning treatments constitutes an important research frontier in plant science.

Determinants of economic growth: Different time different answer?

Almost all studies that use Bayesian model averaging to identify robust growth determinants focus on the growth period between 1960 and the 1990s. We apply Bayesian Model Averaging to a rolling time window of 20 and 35 years using a newly compiled dataset with 37 growth determinants for the years 1960 to 2010. Our findings indicate instabilities in the inferences on growth determinants across growth periods. In line with prior research, we find support for robust ambiguity in early growth periods, that is, cross-country growth regressions provide little support for some growth determinants being more important than others. However, determinants related to demography, education, trade, investment and to some extent religion seem to matter in the subsequent growth periods with education and demography being most important in recent growth periods.

Use of Taxonomic and Trait-Based Approaches to Evaluate the Effects of Transgenic Cry1Ac Corn on the Community Characteristics of Soil Collembola.

Nontarget soil fauna in fields planted with transgenic Bt crops may be influenced by the Bt protein following crop establishment. Here, we investigated the effects of transgenic Cry1Ac corn Bt-799 on soil Collembola using both taxonomic and trait-based approaches in an experimental field in northeast China from 2014 to 2015. The relationship between the collembolan community and environmental variables (including corn type) was investigated using redundancy analysis (RDA). In May 2015, we found that collembolan species richness, Shannon-Wiener's index, and all trait values examined in transgenic Cry1Ac corn (Event Bt-799, Bt corn) were lower than in its near isoline (Zheng 58, non-Bt corn). However, this significant influence did not persist in the subsequent corn growth period. For all other sampling periods over 2-yr study, all indices based on taxonomic (abundance, species richness, and Shannon-Wiener's index) and trait-based (number of ocelli, body size, pigmentation, furcula development, and antennae length) approaches in Bt corn were not significantly different from non-Bt corn. The results showed no significant difference between the two corn types in the repeated-measures analysis of variance (ANOVA). Moreover, redundancy analysis (RDA) showed that corn type only explained 1% of the variation in the collembolan community. These results suggested that Bt corn did not affect collembolan community characteristics in the short term.

Climate-sensitive radial increment model of Norway spruce in Tyrol based on a distributed lag model with penalized splines for year-ring time series

A novel methodological framework is presented for climate-sensitive modeling of annual radial stem increment using year-ring width time series. The approach is based on a generalized additive model with penalized regression splines together with a distributed time lag model taking into account smooth nonlinear effects of a series of monthly temperature and precipitation values, as well as their interactions. Climate effects are also assumed to vary smoothly with time lag. The model framework enables both the detrending of the individual time series and the regression modeling to be performed simultaneously in a single model step. The approach is applied to year-ring width time series of Norway spruce (Picea abies (L.) H. Karst.) trees in Tyrol, Austria. The marginal response curves show that tree growth is mainly promoted by high temperatures in late spring and early summer and by precipitation in fall and winter. Summer drought does not have a negative influence on the current year’s radial increment; however, when it is associated with high temperatures, it lowers the increment in the subsequent growth period. Higher winter precipitation in conjunction with lower temperatures has a positive effect. A significant non-climate related long-term growth trend is demonstrated, probably reflecting NOx and SO2 emission trends in Austria.

Effects of wheat straw mulch application and nitrogen management on rice root growth, dry matter accumulation and rice quality in soils of different fertility

The root is the most sensitive part of the plant. This study examined the effects of wheat straw mulch, nitrogen (N) management and soil fertility on rice root morphology, dry matter accumulation, grain yield and rice quality and explored the correlation between root morphology and rice quality indexes. Wheat straw mulch had an obvious inhibitory effect on rice root morphology, especially on the total root length and total root surface area at 20 days after transplanting in the high- and low-fertility soil. The low-fertility soil treatments had higher levels of inhibition. However, straw mulch significantly promoted root growth, increased dry matter accumulation in the subsequent growth periods and improved the grain yield and rice quality, which mainly reduced the percentage of chalky kernels and the chalkiness degree. Increasing the nitrogen fertilizer percentage applied as a basal or tillering fertilizer reduced the inhibition in the early growth period; for balanced rice root growth, dry matter accumulation, grain yield and rice quality, 30% as basal fertilizer, 30% as tillering fertilizer and 40% as panicle fertilizer were the best N management strategy. Correlation analysis showed that the rice quality was extremely significantly positively correlated (r = 0.30–0.59, P < 0.05) with the root morphology indexes of the brown rice and protein contents and was significantly or extremely negatively correlated (r = − 0.73 to − 0.28, P < 0.05) with the length–width ratio, percentage of chalky kernels, chalkiness degree and amylose content.

QCM-D for non-destructive real-time assessment of Pseudomonas aeruginosa biofilm attachment to the substratum during biofilm growth

Quartz crystal microbalance with dissipation monitoring (QCM-D) was used to investigate initial adhesion and subsequent biofilm growth of wild-type Pseudomonas aeruginosa PAO1 and a pili-deficient (ΔpilA) mutant PAO1 strain. Clean, sterilized, silica-coated QCM-D crystals were pre-coated with lysogeny broth (LB), seeded with a PAO1 strain and allowed to grow for 20h at 37°C in fresh LB injected at 100μL/min. QCM-D signals obtained for the wild-type PAO1 strain during the seeding period depict a large positive frequency shift that returns to baseline after ∼20min that is absent in the ΔpilA mutants, suggesting a dynamic pili-mediated attachment event for the wild-type PAO1 strain. During the subsequent growth period, significant and characteristic differences in the acquired QCM-D signals were observed between the wild-type and the ΔpilA mutant. Confocal laser scanning microscopy (CLSM) of the biofilm on the crystal surface showed that these differences could not be explained by differences in the extent of biofilm growth alone. When interpreted according to a coupled resonance model, the QCM-D observations suggest that pili are essential for coupling the developing biomass to the sensor surface. Total internal reflection fluorescence microscopy (TIRF) supports the hypothesis that the characteristic QCM-D signal is indicative of a dynamic attachment event, mediated by pili cell surface appendages pulling the wild-type PAO1 closer to the surface during the seeding period. We show that QCM-D offers direct, non-disruptive, in situ measurements of biofilm-substrate attachment. This technique has the potential to improve the current understanding of biofilm formation phenomena.

The major aliphatic glucosinolate content in Korean radish during vegetative and reproductive growth

Glucosinolates (GSLs) are secondary metabolites abundant in Brassica vegetables and the interest on this compound has been grown due to their health benefits. The amounts of major aliphatic GSLs, glucoraphasatin (GRH), and glucoraphenin (GRE) were measured in five radish cultivars during their vegetative and reproductive growth. The GRE content was higher in seed (ranging from 16.5 to 19.4 mg·g−1 dry weight) than that of leaves or roots in all five genotypes. The GRE content sharply declined during germination and remained stable at the basal level for the subsequent vegetative growth period. In contrast, the amount of GRH, an immediate precursor of the GRE, steadily increased during the early growth period up to 8 weeks and remained at a similar level thereafter. As growth of seedlings progressed, the inner leaves contained higher amounts of GRH than the outer leaves. In roots, smaller amounts of GRE were found, as compared to other tissues. However, the GRH was abundant in roots and mature inner leaves. The GRE tended to accumulate in reproductive organs, while GRH was found primarily in the roots and the inner leaves at the mature stage.

Effect of Seed Size, Suspension Recycling and Substrate Pre-Treatment on the CVD Growth of Diamond Coatings

CVD growth of uniform conformal polycrystalline diamond (PCD) coatings over complex three dimensional structures is very important material processing technique. It has been found that the nucleation and subsequent growth period is very critical for successful development of CVD diamond based technologies. There are many methods of enhancing diamond nucleation on foreign substrates-ultrasonic treatment with diamond seed suspension being the best among them. A combination of ultrasonic seeding (US) technique with prior treatment (PT) of the substrate under CVD diamond growth conditions for brief period of time, has found to be very effective in enhancing the diamond nucleation during CVD growth—together they are known as NNP. But successive usage of the same seeding suspension up to ten cycles deteriorates the seeding efficiency. 6th seeding cycle onwards the silicon substrates are barely get covered by diamond crystallites. Five different diamond micron grits were used for seeding the silicon substrates and it is observed that US with the sub-micron particles (0.25 μm) is very effective in efficient nucleation of PCD on Si substrates. PT of the substrate somewhat negates the effect of successive use of the same seeding slurry but it is best to avoid recycling of the same seeding suspension using micron size diamond grits.

Tracking changes in the vraSR and graSR two component regulatory systems during the development and loss of vancomycin non-susceptibility in a clinical isolate

We investigated changes in regulatory genes, vraS and graR, during development of vancomycin non-susceptibility in a patient with methicillin-resistant Staphylococcus aureus who failed therapy and following in-vitro vancomycin exposure and a subsequent drug-free growth period. Minimum Inhibitory Concentration (MICs) were determined and genes sequenced at each stage. After 30 days of vancomycin exposure, the strain attained maximum MIC (20 mg/L) and was resistant to all antibiotics. Reversion to vancomycin susceptibility occurred 21 days after removal. We observed mutations in vraS and graR during non-susceptibly development and novel stop codons in the reverted strain. Mutations in graR appear important for development of intermediate susceptibility to vancomycin. The results suggest that monitoring of vancomycin therapy could allow earlier change to appropriate agents.

DYNAMICS OF FABA BEAN GROWTH AND NUTRIENT UPTAKE AND THEIR CORRELATION WITH GRAIN YIELD

Growth parameters and nutrient uptake of faba bean with 12 different genotypes were studied at the end of four subsequent growth periods, viz. first vegetative (V1), second vegetative (V2), first reproductive (R1) and second reproductive (R2) periods for two years and correlated with final grain yield. All parameters including plant height, leaf number, leaf area index (LAI), above ground plant dry matter (DM) and root DM, nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) uptake and concentration of N, P, K, Ca, and Mg showed different patterns with advancement of the growth period. All the mentioned parameters were fitted in either quadratic or linear equations. Significant correlations were found among nutrients, growth parameters and grain yield during different growth stages. On the basis of these experiments it was clear that nutrient uptake was directly related to biomass. In V2 and R1 biomass production was greatest resulting in high nutrient uptake. Among the growth parameters, biomass and LAI showed the highest significant correlation with grain yield. The findings especially models derived from two year data across twelve genotypes can be used for better fertilizer management of faba bean.

Evaluation of yield and physiological attributes of high-yielding rice varieties under aerobic and flood-irrigated management practices in mid-hills ecosystem

Abstract In the valley land of North-East Hill (NEH) ecosystems of India, about 70% area under rice ( Oryza sativa L.) is transplanted. Physiological attributes and yield performance of aerobic rice over conventional flood-irrigated rice need to be assessed while promoting water saving technology. A field experiment was conducted at the experimental farm, ICAR Research Complex for NEH Region, Umiam (950 m msl), Meghalaya during rainy seasons of 2006 and 2007 under aerobic and flooded conditions with aerobic rice variety collected from IRRI, Philippines. Some important high-yielding varieties (HYVs) recommended for the region were also included in the study. The objectives of this study were (i) to evaluate the influence of frequent mid-season drainage as a measure of water saving technique besides inducing the pre-conditioning effect on genotypes to withstand water stress during the subsequent growth period of crop ontogeny, (ii) to compare crop performance between aerobic and flooded rice management practices, and (iii) to identify attributes responsible for the yield gap between aerobic and flooded rice. The results revealed that the yield difference between aerobic (average yield, 1.67 t/ha) and flooded rice (average yield, 2.31 t/ha) ranged from 18.4 to 37.8% ( P 0.05) depending on varieties, highest difference being observed with rice hybrid DRRH 1. Cultivation of rice under aerobic condition resulted in 27.5% yield reduction over flooded rice. Among the yield components assessed, sink size (spikelets per panicle) contributed more to the yield and is considered to be most important factor responsible for yield gap between aerobic and flooded rice. The study suggests that, variety Sahsarang 1 with its moderate values of photosynthesis rate, transpiration rate and water use efficiency (WUE) along with higher grain yield seems to be better choice for both stress (aerobic) as well as normal (flooded) condition. Aerobic rice varieties with minimum yield gap compared to flooded rice is the key for success of aerobic rice cultivation.

Can iron be teratogenic?

Several kinds of evidence indicate that elevated iron during the 3-8 week embryonic (organogenesis) period of human gestation may be teratogenic. (1) In the embryonic period, the natural maternal absorption of food iron is 30% below the estimated daily iron loss. (2) As compared with maternal serum, embryonic fetal coelomic fluid contains only one-fourth as much iron but nearly six times the quantity of the iron withholding protein, ferritin. (3) In the embryonic period, intraplacental oxygen pressure is 2-3 times lower than in the subsequent fetal growth period. (4) Iron is a strong inducer of emesis which peaks in the embryonic period. (5) In a murine gestation model, iron was neurotoxic at a sharp peak of 8-9 days. Thus it would be prudent, in human pregnancy, to delay any needed iron supplementation until the embryonic period has been completed.

The influence of soil water deficit imposed during various developmental phases on physiological processes of tef ( Eragrostis tef)

Physiological responses of tef ( Eragrostis tef (Zucc.)) to water stress during establishment, vegetative, flag leaf-1 and grain filling developmental stages were studied under glasshouse conditions in 2007 at Henfaes Research Centre, University of Wales, Bangor, UK using a “near-factorial” randomised complete block design. During each phenological phase plants were subjected to three levels of soil moisture tension viz., FC (−0.12 MPa), 50%FC (−1.06 MPa) and 25%FC (−1.51 MPa) until the completion of the specific phases and during the preceding and subsequent growth periods the stressed plants were irrigated to field capacity (FC). A maximum net CO 2 assimilation (12.15 μmol m −2 s −1) and transpiration (3.88 mmol m −2 s −1) rates were recorded in the control treatment. Both levels of water stress during flag leaf-1 and grain filling development stages reduced these rates significantly. Severe water stress imposed during grain filling stage produced the lowest rates in both CO 2 assimilation (−2.80 μmol m −2 s −1) and transpiration (0.15 mmol m −2 s −1). Response curves of CO 2 assimilation rates to PAR levels showed that initial photosynthetic efficiency (at light saturation point) of severely stressed tef was less (0.013 μmol CO 2/μmol photons) than the corresponding efficiencies of other treatments ( P < 0.001). The grain filling stage of tef was the most sensitive to water stress and severe water stress caused significant reduction in physiological performance of tef. The low yielding nature of tef could be associated with its low light use efficiency which perhaps related to its leaf size and orientation. Therefore, improving tef light use efficiency should be a national agenda to improve its yielding potential.

Flooding Effects on Plants Recovering from Defoliation in Paspalum dilatatum and Lotus tenuis

Flooding and grazing are major disturbances that simultaneously affect plant performance in many humid grassland ecosystems. The effects of flooding on plant recovery from defoliation were studied in two species: the grass Paspalum dilatatum, regrowing primarily from current assimilation; and the legume, Lotus tenuis, which can use crown reserves during regrowth. Plants of both species were subjected to intense defoliation in combination with 15 d of flooding at 6 cm water depth. Plant recovery was evaluated during a subsequent 30-d growth period under well-watered conditions. Plant responses in tissue porosity, height, tiller or shoot number and biomass of the different organs were assessed. Flooding increased porosity in both P. dilatatum and L. tenuis, as expected in flood-tolerant species. In P. dilatatum, defoliation of flooded plants induced a reduction in plant height, thus encouraging the prostrated-growth response typical of defoliated plants rather than the restoration of contact with atmospheric oxygen, and most tillers remained submerged until the end of the flooding period. In contrast, in L. tenuis, plant height was not reduced when defoliated and flooded, a high proportion of shoots being presented emerging above water (72 %). In consequence, flooding plus defoliation did not depress plant recovery from defoliation in the legume species, which showed high sprouting and use of crown biomass during regrowth, whereas in the grass species it negatively affected plant recovery, achieving 32 % lower biomass than plants subjected to flooding or defoliation as single treatments. The interactive effect of flooding and defoliation determines a reduction in the regrowth of P. dilatatum that was not detected in L. tenuis. In the legume, the use of crown reserves seems to be a key factor in plant recovery from defoliation under flooding conditions.

Early Onset Scoliosis: Future Directions

The management of children with severe, progressive early onset scoliosis has been greatly advanced in the last decade, yet there is considerably more research to be accomplished in the future. In this concluding article, we review some of the major issues for future research with regard to this rare but potentially fatal disease. Despite the similar clinical appearances of the various forms of early onset scoliosis, the etiologies are different; however, little is known regarding etiology, particularly with regard to genetic defects. Further research is necessary to distinguish the various types of early onset scoliosis. Only by understanding the etiology can true advances be made in altering the natural history of early onset scoliosis. Research in the area of etiology will require increased funding through the National Institutes of Health and other agencies. Due to its low prevalence, early onset scoliosis currently does not have a high priority with these agencies. ### Growing Rods #### Single and Dual Growing Rods As discussed throughout this symposium, posterior instrumentation without fusion, with the use of single or dual growing rods, has been used to treat progressive early onset scoliosis in young children. The goals of treatment have been to achieve correction of the spinal deformity, maintain correction during the subsequent growth period, allow spinal growth and lung development, and avoid or eliminate the need for definitive fusion of the spine at an early age. A recent study has demonstrated improved surgical results with use of the dual growing rod technique1. These improvements are primarily due to the ability to achieve a more stable construct and to the performance of more frequent lengthening procedures. The results of a recent long-term study that examined the outcomes of the dual growing rod technique have confirmed that there is significantly better correction of scoliosis (p = 0.0256) and better achievement of growth1 …