Effects of 17β-Estradiol on Growth, Primary Metabolism, Phenylpropanoid-Flavonoid Pathways and Pathogen Resistance in Arabidopsis thaliana

Mammalian sex hormones are spread in the environment from natural and anthropogenic sources. In the present study, the effect of estradiol on Arabidopsis thaliana growth primary metabolism, phenylpropanoid and flavonoid pathways and pathogen resistance were investigated. Treatments of Arabidopsis plants with 10 and 100 nM 17β-estradiol resulted in enhanced root growth and shoot biomass. In addition, treated plants had an increased rate of photosynthesis with a concomitant increase in carbohydrate and protein accumulation. Plants exposed to higher concentrations of 17β-estradiol (10 μM) had significantly lower root growth, biomass, photosynthesis rate, primary metabolite and phenylpropanoid and flavonoid contents indicating a toxic effect of estradiol. Treatments with increasing estradiol concentrations (10 nM, 100 nM and 10 μM) resulted in the downregulation of phenylpropanoid-flavonoid pathway genes (PAL1, PAL4, CHI and ANS) and subsequent decreased accumulation of phenolics, flavonoids and anthocyanins. Estradiol-treated plants were inoculated with Pseudomonas syringae pv. Tomato DC3000 and basal resistance was determined. Estradiol treatments rendered plants susceptible to the pathogen, thus compromising the plant defense mechanisms. These results indicate that at low concentrations, estradiol functions as a biostimulant of growth, yield and primary metabolism of Arabidopsis. However, estradiol functions as a potential transcriptional regulator of the phenylpropanoid pathway genes in Arabidopsis, having a negative effect on the phenylpropanoid and flavonoid biosynthetic pathways.

Using distance education in teaching orthotic fabrication to occupational therapy students

Occupational therapy (OT) education requires educators to provide students with entry level skills in orthotic fabrication. These skills have been taught in a traditional face-to-face classroom and labs. The concept of distance education (DE) has evolved over the years with the advancement of the technology. DE started with print media, radio broadcasting, and progressed to utilizing video conferencing. Currently DE relies heavily on using the internet to deliver quality, cost-effective and convenient education. DE Literature focused on teaching basic knowledge, however, no research was found that compared DE to traditional education in teaching skills or the application of knowledge. This pilot study investigated the effectiveness of using DE pedagogy in teaching OT students the skills of splint making, and to compare effectiveness of DE to that of traditional classroom. Forty OT students participated in the study, they self-selected to be in the experimental, or control group. The experimental group received training on splint making via the Blackboard?, while the control group received similar training the traditional way. The quality of splints was evaluated;Mann-Whitney concluded that the difference between the means of the two groups was no significant, indicating that the quality of the splints were equivalent.

The impact of the coronavirus disease 2019 pandemic on physical activity in U.S. children

Background:Daily moderate-to-vigorous physical activity(MVPA)is vital to the physical,mental,and social well-being of children.Early restrictions during the coronavirus disease 2019(COVID-19)pandemic included the closure of schools and physical activity(PA)amenities across the US.This study aimed to examine the impact of the pandemic on the PA and play behavior of U.S.children and to provide evidencebased recommendations to improve their PA.Methods:A cross-sectional,online,parent-reported survey was conducted of children aged 318 years between April and June 2020 to assess light PA and MVPA using a modified Godin Leisure-Time Exercise Questionnaire.Additional items included family/child socioeconomic demographics,child adaptability to the pandemic,and community access.The survey was shared through social media and snowball sampling distribution.Results:Analysis of 1310 surveys indicated child PA scores declined significantly during the pandemic(from 56.6 to 44.6,max 119,p<0.001).Specifically,MVPA score decreased(from 46.7 to 34.7,max 98,p<0.001)while light PA remained the same.Age-based changes were seen in the quantity,variety,and intensity of PA,with the lowest pandemic-related impact seen in preschoolers and the highest in high schoolers(4.7 vs.17.2,p<0.001).Community-based peer PA decreased across all age groups.Conclusion:This study shows decreased PA levels in U.S.children,according to parent reporting,during the COVID-19 pandemic.Recommendations for community leaders,educators,and parents to improve PA in children are provided.With continued spread of COVID-19,these results and recommendations may be imperative to the physical well-being of U.S.children.

Alleviation of Drought Stress in Arabidopsis thaliana by 17β-Estradiol Application

Animal steroidal hormones, including estrogens, are being introduced into the agricultural soil and water supply from increased pharmaceutical and farm waste. Considering the current levels of xenoestrogen contamination of plant environments in view of the climate change induced drought conditions, this study was designed to understand the effect of estradiol (ES) application on Arabidopsis drought stress responses. Estradiol treatment (10 nM, 100 nM) of plants subjected to drought stress conditions by withholding water for 7 days resulted in increased tolerance to drought stress reflected in the significantly higher plant survival rates of 74% and 78%, respectively compared to control plants’ survival rates of 36% (no treatment) and 40% (mock treatment). Estradiol application significantly increased the content of glutathione, proline and H2O2 and significantly enhanced the transcription of the stress responsive genes GSTU3, GER5, HSP101, and HSP70b. A high concentration of ES (10 μM) did not protect plants against drought stress and proved to be toxic. These results provide new insight into the effect of ES on drought-stress responses in Arabidopsis with possible practical agricultural applications regarding the effect of environmental estrogens on crop plants.

Whole Body Vibration:The Effect of Position and Frequency on Perceived Exertion in Healthy,Active Adults

Whole Body Vibration(WBV)is a new exercise trend in fitness and performance enhancement.WBV platforms oscillate over a range of frequencies and amplitudes;however no study to date has examined the experience of perceived exertion with differences in vibration frequency and static or dynamic body position,nor examined the difference between sexes based on position and frequency during WBV.The purpose of this study was to assess the effects of position and frequency on perceived exertion during WBV in healthy,active adults.A convenience sample of 39 healthy young adults who participated in moderated exercise was blinded and randomly allocated to six WBV conditions composed of different frequency and position combinations.The participants received instruction,provided informed consent,participated in a warm-up session,and then reported rating of perceived exertion for each WBV condition.A 2×3 within-subjects multivariate approach ANOVA was conducted against an alpha of 0.05.A statistically significant main effect of position(p=0.004)and significant main effect of frequency(p=0.025)were found.Significant marginal means were found between the frequencies of 0 Hz and 50 Hz(p=0.007).Statistically significant differences were found between sexes for all combinations.

Volume Change of the Random Coil to Folded Conformational Transition of <i>Thermomyces</i><i>lanuginosus</i>Xylanase at 24&#176C and pH = 7.0 via Application of the Clausius-Clapeyron Equation

A partial phase diagram characterizing the conformational change that occurs in Thermomyces lanuginosus xylanase as it is slowly heated in 150 mM sodium phosphate (pH = 7.0) has been con-structed from slow-scan-rate differential scanning calorimetry measurements. The Clausius-Clapeyron equation was applied to determine an associated volume change of -205 L·mol-1 at 24°C, the equilibrium transition temperature at 1.0 atm pressure. This value is in excellent agreement with that predicted using a previously published [1] empirical equation for calculating the hydro-dynamic radius if the transition is regarded as from a random coil to a functional, folded state and with the assumption that the hydrodynamic radius is a good approximation of the true random coil radius. The existence of a low-temperature random coil is confirmed by circular dichroism and dynamic light scattering measurements. Thus, at 24°C and 1.0 atm pressure the enzyme appears to fold from a random coil to a functional, folded form as it is slowly heated.

A single base permutation in any loop of a folded intramolecular quadruplex influences its structure and stability

The human telomere sequence (TTAGGG)4 folds into an unusual conformation possessing three G-tetrads linked by TTA loops. The first loop is a propeller loop while the second and third loops are transverse loops. Using Circular Dichroism (CD) spectroscopy, we have investigated the effect of sequence context on the structures and stabilities of intramolecular G-quadruplexes related to the human telomere sequence by considering all permutations of T and A within the loops. The results indicate that changing only one base in any one loop can have a dramatic effect on the conformation of the quadruplex as well as its melting temperature, Tm. Thus, each sequence studied has a unique CD spectrum and Tm. In general, variants with a modified second loop are the most stable while the wild type sequence is the least stable. The observed difference in CD spectra and melting temperature are discussed in terms of base stacking within the loop and stacking of the loop bases with adjacent G-tetrads.

SMXL5 attenuates strigolactone signaling in Arabidopsis thaliana by inhibiting SMXL7 degradation

Hormone-activated proteolysis is a recurring theme of plant hormone signaling mechanisms.In strigolactone signaling,the enzyme receptor DWARF14(D14)and an F-box protein,MORE AXILLARY GROWTH2(MAX2),mark SUPPRESSOR OF MAX21-LIKE(SMXL)family proteins SMXL6,SMXL7,and SMXL8 for rapid degradation.Removal of these transcriptional corepressors initiates downstream growth responses.The homologous proteins SMXL3,SMXL4,and SMXL5,however,are resistant to MAX2-mediated degradation.We discovered that the smxl4 smxl5 mutant has enhanced responses to strigolactone.SMXL5 attenuates strigolactone signaling by interfering with AtD14-SMXL7 interactions.SMXL5 interacts with AtD14 and SMXL7,providing two possible ways to inhibit SMXL7 degradation.SMXL5 function is partially dependent on an ethylene-responsive-element binding-factor-associated amphiphilic repression(EAR)motif,which typically mediates interactions with the TOPLESS family of transcriptional corepressors.However,we found that loss of the EAR motif reduces SMXL5-SMXL7 interactions and the attenuation of strigolactone signaling by SMXL5.We hypothesize that integration of SMXL5 into heteromeric SMXL complexes reduces the susceptibility of SMXL6/7/8 proteins to strigolactone-activated degradation and that the EAR motif promotes the formation or stability of these complexes.This mechanism may provide a way to spatially or temporally fine-tune strigolactone signaling through the regulation of SMXL5 expression or translation.

d-δ-三烯生育酚对人鼻咽癌CNE2细胞株增殖和凋亡的影响

目的探讨d-δ-三烯生育酚对人鼻咽癌细胞增殖与凋亡的影响。方法实验设对照组和不同d-δ-三烯生育酚浓度(40、50、60μmol/L)处理的实验组,采用Hoechst荧光染料染色和显微镜观察细胞的形态。3-(4,5二甲基噻唑-2)-2,5-二苯基四氮唑溴蓝(MTT)实验、流式细胞术分析d-δ-三烯生育酚对CNE2细胞的增殖、周期和凋亡的影响。结果 d-δ-三烯生育酚处理CNE2细胞48 h后,随d-δ-三烯生育酚的浓度升高,细胞生长抑制率明显增加,分别为(27.71±1.01)%、(57.09±0.56)%和(95.04±0.17)%,与对照组相比,差异具有统计学意义(P<0.01);细胞核或细胞浆内出现致密浓染的颗粒状或条块状荧光的凋亡细胞明显增多,实验组细胞凋亡率分别为(9.18±1.86)%、(34.97±1.01)%和(52.97±2.77)%,与对照组(1.58±0.48)%比较,随浓度升高,凋亡细胞率增加,差异具有统计学意义(P<0.01);实验组S期的细胞百分率分别为(25.40±1.93)%、(35.83±3.74)%和(47.13±2.49)%,与对照组(19.63±1.46)%比较,细胞呈S期阻滞,差异具有统计学意义(P<0.05)。结论 d-δ-三烯生育酚具有抗鼻咽癌CNE2细胞的生物学活性。

骨密度测量中精密度的重要性

骨密度测定 ,不论采取何特殊技术 ,即使严格地按照厂家建议的操作程序 ,也常常不能达到完美的重复性。必须确定每台骨密度仪不同骨骼部位的精确度。精密度 ,如标准差平均方根或变异系数平均方根 ,被用来确定骨密度的变化 ,即精密度决定最小显著性变化值和随访需要的至少时间间隔。除非确定了精密度 ,否则就不能确定任何水平的统计可信度最小显著性变化值 。