Arabinogalactan Proteins as Interactors along the Crosstalk between the Pollen Tube and the Female Tissues

Arabinogalactan proteins (AGPs) have long been considered to be implicated in several steps of the reproductive process of flowering plants. Pollen tube growth along the pistil tissues requires a multiplicity of signaling pathways to be activated and turned off precisely, at crucial timepoints, to guarantee successful fertilization and seed production. In the recent years, an outstanding effort has been made by the plant reproduction scientific community in order to better understand this process. This resulted in the discovery of a fairly substantial number of new players essential for reproduction, as well as their modes of action and interactions. Besides all the indications of AGPs involvement in reproduction, there were no convincing evidences about it. Recently, several studies came out to prove what had long been suggested about this complex family of glycoproteins. AGPs consist of a large family of hydroxyproline-rich proteins, predicted to be anchored to the plasma membrane and extremely rich in sugars. These two last characteristics always made them perfect candidates to be involved in signaling mechanisms, in several plant developmental processes. New findings finally relate AGPs to concrete functions in plant reproduction. In this review, it is intended not only to describe how different molecules and signaling pathways are functioning to achieve fertilization, but also to integrate the recent discoveries about AGPs along this process

Strength training effects on pre-pubertal boys

There are some incongruent results in strength training effects on pre-pubertal boys. Vrijens (1979) shows that prepubescent boys were incapable of increasing strength or muscle cross-sectional area of the extremities following a program of resistance training. Various recent studies have shown that prepubescent boys are capable of making strength gains following an appropriate training program (Ramsay, et al., 1990). However the mechanisms underling strength gains following resistance strength training programs is not well clarified. There is some evidence that the gains are associated with neuromuscular adaptations with no muscle hypertrophy, but this later issue is an unresolved question. The purpose of this study is to investigate the resistance strength training effects on pre-pubertal boys, that is, the enhancement of strength and its correlates, namely the changes in muscular mass and neuro-muscular activity. The sample comprises 11 boys, aged 9,52±0,55 years, divided in an experimental group (EG) (n=6) and in a control group (CG) (n=5). All boys were in stage 1 according to Tanner’s scale of sexual maturation. The sample was evaluated in serum testosterone level, and all boys were above the level of 50 ng*dl-1,wich is considered to be within the normal range for pre-pubertal boys (Winter, 1978). The EG group was submitted to a training program with callisthenic exercises three sessions a week for 10 weeks. In each session the training comprised the following exercises: push-ups, modified pull-ups and the 2 exercises with elastics (elbows flexion and extension and extension of the arms above the head) until exhaustion. The training volume was being gradually adapted from 3 series between the 1st and 3rd week to 4 series between the 4th and 6th week and to 5 series between the 7th and 10th week. The sample was evaluated in pre and in post-test in maximal isometric voluntary force (MIVF), muscle mass, and in EMG. The MIVF was evaluated during the Shoulder Press (SP), the Arm Curl (AC) and the Triceps Press (TP). The MIVF was measured using a dynamometer (TST 121C from Biopac Systems Inc.). We also evaluated the maximal number of push ups (PU) and modified pull ups (MPU), and the distance in over arm throw with roller-skate hockey ball (THW). The EMG signals were acquired during the MIVF exercises (SP, AC, and TP). During the AC exercise, one surface electrode (TSD 150A from Biopac Systems Inc.) was attached to each biceps. During the SP and TP, one surface electrode was attached to the vastus medialis of each of the triceps. A ground electrode was attached to the elbow. The EMG signals were amplified through a differential amplifier with 2MW, a gain of 1000 and a bandwidth between 15-450Hz. The EMG signals were full-wave rectified and smoothed, allowing to determinate the integral (iEMG) and the amplitude (aEMG) of the EMG signal. The iEMG was standardised according to the duration of the contraction. Both aEMG and iEMG results of both arm in each exercise were summed. The muscle thickness of the biceps and of the triceps of both arms were measured by B-mode ultrasonography, using real-time electronic scanner with 7.5MHz scanning head (Ecocamera Aloca SSD-500). The data were analysed using the ANOVA repeated measures (group x training program). In THW the results indicate a significant interaction effect (F(1, 9) = 7,814; p = 0,021), with an increase of 22% in EG and a slight decrease in CG. In PU the results indicate a significant main effect (F(1, 9) = 15,537; p = 0,003), and a significant interaction effect (F(1, 9) = 16,61; p = 0,003), with an increase of 150% in EG and no changes in CG. In MPU the results indicate a significant main effect (F(1, ) = 8,006; p = 0,019), and a significant interaction effect (F(1, 9) = 17,667; p = 0,002), with an increase of 120,9% in EG and a slight decrease in CG. There were no significant changes in the three tests of MIVF and in iEMG, aEMG, or in the muscle mass. These results indicate that pre-pubertal boys could increase the resistance strength after a training program that include callisthenic exercises, but seems that the isometric strength could not be enhanced. The increase in resistance strength is not accompanied by an increase in muscle mass. Although in this study we only evaluated the neuro-muscular factors in MIVF, it seems that the factors underlying the enhanced strength might be neuro-muscular.info:eu-repo/semantics/publishedVersio

Habitual physical activity pattern of prepubescent boys and girls

The propose of this study is to identify the pattern physical activity of boys and girls during a week. The sample comprises 14 girls and 11 boys of 9.5 years of age. Physical activity was evaluated thought the computer science and applications (CSA - 7164) activity monitor, during 4 days - two-week days (Monday and Friday), and during the weekend (Saturday and Sunday). The activity monitor was worn in wrist of the non-dominant arm. After de data collection it was calculated the mean of activity per min in each day. The repeatedmeasuresMANOVAwasusedtoanalysedthechangesbetweenday's activity,and the gender differences. The results indicated a significant main effects of days, meaning that the pattern of activity change over days. The differences occurred between the Friday and Saturday, and between Saturday and Sunday. In the weekend it was registered less physical activity than in weekdays in booth boys and girls. There's no significant main effect for gender, meaning that the physical activity of boys and girls are similar. Also there's no interaction between gender and days, meaning that the changes in activity pattern was similar for booth boys and girls.info:eu-repo/semantics/publishedVersio

Comparison of muscle morphology, electromyographic activity and force production between prepubertal boys and girls

The purpose of this research was to compare the maximal voluntary isometric force (MVIF), the electromyographic activity (EMG) and the muscle thickness between pre-pubertal boys and girls. The sample comprises 27children (12 boys and 15 girls) with 9.5W.52 years old. The M V F and the EMG signal were acquired when the subjects made a single exercise of arm curl and triceps press. To evaluate the MVIF was used a dynamometer (TSD121C from Biopac Systems Znc.). During the arm curl exercise, one surface electrode (TSD 150A from Biopac Systems Znc.) was attached in each biceps. During the triceps press, one surface electrode was attached to the vastus lateralis and other to the vastus medialis of the each triceps. Ground electrode was attached to the elbow. The EMG signals were amplified by a differential amplifier with 2MW, a gain of 1000 and a bandwidth between 15-450Hz. The EMG signals were full-wave rectified and smoothed, allowing to determinate the integral of the EMG signal (iEMG). The iEMG was relativized according to the duration of the contraction. The muscle thickness of the biceps and of the triceps of both arms were measured by B-mode ultrasonography, using real-time electronic scanner with 7.5MHz scanning head (Ecocamera Aloca SSD-500). For comparison of those variables between gender was used the ANOVA factorial and Scheffe as post-hoc test (p< 0.05). There was no significant differences on the MVIF between boys and girls doing the arm curl exercise F(1; 25)=4.128, p=0.0529] or the triceps press exercise F(1; 25)=0.003, p=0.9554]. In the same way, there were no significant differences according to gender on the thickness of the triceps of the left arm F(1; 25)= 0.075, p=0.7859] of the triceps of the right arm F(1;25)=0.925, p=0.3454] of the bicep sof the left arm F(1;25)=0.257, p=0.6166] and of the biceps of the right arm F(1; 25)= 0.016, p=0.8989]. The EMG parameters also didn't present significant differences according to gender for the vastus lateralis of both arms, for the vastus medialis of both arms and for the biceps of the right and of the left arm. Therefore, we might conclude that apparently there are no significant differences on the muscle morphology, electromyographic activity and force production between pre-pubertal boys and girls.info:eu-repo/semantics/publishedVersio

Effects of a 10 weeks training programs on prepubescent girls

The purpose of this study was to investigate effects of a training program on the development of the maximal isometric strengths, the push-ups, the pull-ups and the throw of the roller-skate hockey ball. The sample was composed by 16 girls, at the age of 9,5 years and in the maturation stage I according to Tanner's Scale. The sample was divided into two different groups, the experimental one (EG, n = 11) and the control one (CG, n = 5). The EG group was submit- ted to a training program with callisthenic exercises three times a week (90 min each session) during 10 weeks. The program comprised the training of push-ups, modified pull-ups and the 2 exercises with elastics (elbows flexion and extension and extension of the arms above the head) until exhaustion. The training volume has been gradually adapted from 3 series between the 1st and 3rd week to 4 series between the 4th and 6th week and to 5 series between 7th and 10th week. The maximal isometric voluntary force (MIVF) was evaluated during the Shoulder Press (SHPRES) exercise, the Arm Curl (ARMCURL) exercise and de Triceps Press (TRIPES) exercise. The MIVF was measured using a dynamometer (TST 121C from Biopac Systems Inc.). We also evaluated the maximal number of push ups and modified pull ups that each girl could do. Finally, we measured the distance made by the roller-skate hockey ball after being thrown (THRW). For the comparison between the two measurements (before and after the training program) was raised the "Paired Simple Test" in each group (p < 0.05). It compared the minimum values between the two moments on the e.g., the THRW (p = 0.006), the PULL (p=0.010), and the PUSH (p= 0.014), presented significant increases. However, the TRIPES (p = 0.096), the ARMCURL (p = 0.403), and the SHPRES (p = 0.066) didn't present significant differences. On the CG the only significant difference was found in the TRIPES (p = 0.003).info:eu-repo/semantics/publishedVersio

Spironolactone treatment attenuates vascular dysfunction in type 2 diabetic mice by decreasing oxidative stress and restoring NO/GC signaling

Type 2 diabetes (DM2) increases the risk of cardiovascular disease. Aldosterone, which has pro-oxidative and pro-inflammatory effects in the cardiovascular system, is positively regulated in DM2. We assessed whether blockade of mineralocorticoid receptors (MR) with spironolactone decreases reactive oxygen species (ROS)-associated vascular dysfunction and improves vascular nitric oxide (NO) signaling in diabetes. Leptin receptor knockout [LepRdb/LepRdb (db/db)] mice, a model of DM2, and their counterpart controls [LepRdb/LepR+, (db/+) mice] received spironolactone (50 mg/kg body weight/day) or vehicle (ethanol 1%) via oral per gavage for 6 weeks. Spironolactone treatment abolished endothelial dysfunction and increased endothelial nitric oxide synthase (eNOS) phosphorylation (Ser1177) in arteries from db/db mice, determined by acetylcholine-induced relaxation and Western Blot analysis, respectively. MR antagonist therapy also abrogated augmented ROS-generation in aorta from diabetic mice, determined by lucigenin luminescence assay. Spironolactone treatment increased superoxide dismutase-1 and catalase expression, improved sodium nitroprusside and BAY 41-2272-induced relaxation, and increased soluble guanylyl cyclase (sGC) β subunit expression in arteries from db/db mice. Our results demonstrate that spironolactone decreases diabetes-associated vascular oxidative stress and prevents vascular dysfunction through processes involving increased expression of antioxidant enzymes and sGC. These findings further elucidate redox-sensitive mechanisms whereby spironolactone protects against vascular injury in diabetes

Effects of exercise programs on phase angle in older adults: a systematic review and meta-analysis.

The purpose of this study was to calculate the effects of exercise programs on phase angle (PhA) in older people. A systematic review was undertaken in multiple electronic databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement guidelines for the purposes of selecting randomized controlled trials that measured the effects of the exercise programs on PhA in older adults on 31 March 2022. We carried out a random-effect meta-analysis for the effects of exercise programs on PhA. Additionally, we analysed the differences between subgroups in terms of weekly frequency, number of sets and repetitions, and duration of interventions. Studies were methodological assessed through the PEDro scale where one had excellent, ten had good, and three had poor methodological quality. For the purposes of the study, fourteen studies met the criteria for inclusion. However, four studies did not have enough information to be included in the quantitative analysis. The remaining ten articles revealed moderate effects on PhA in favour of intervention groups (p=0.009, SMD=0.72 [0.46–0.99], I2=54%). The meta-analysis also showed that interventions lasting twelve weeks are more successful in generating positive effects on PhA as opposed to eight weeks (SMD’s=0.79 vs. 0.64, respectively). These results indicate that resistance training (RT) is an effective and safe to improve PhA in the older people, especially through RT programs lasting from eight to twelve weeks. A novel finding of this study was that RT is the most used type of exercise by authors when assessing the PhA in older adults

Linking the beneficial effects of current therapeutic approaches in diabetes to the vascular endothelin system

The rising epidemic of diabetes worldwide is of significant concern. Although the ultimate objective is to prevent the development and find a cure for the disease, prevention and treatment of diabetic complications is very important. Vascular complications in diabetes, or diabetic vasculopathy, include macro- and microvascular dysfunction and represent the principal cause of morbidity and mortality in diabetic patients. Endothelial dysfunction plays a pivotal role in the development and progression of diabetic vasculopathy. Endothelin-1 (ET-1), an endothelial cell-derived peptide, is a potent vasoconstrictor with mitogenic, pro-oxidative and pro-inflammatory properties that are particularly relevant to the pathophysiology of diabetic vasculopathy. Overproduction of ET-1 is reported in patients and animal models of diabetes and the functional effects of ET-1 and its receptors are also greatly altered in diabetic conditions. The current therapeutic approaches in diabetes include glucose lowering, sensitization to insulin, reduction of fatty acids and vasculoprotective therapies. However, whether and how these therapeutic approaches affect the ET-1 system remain poorly understood. Accordingly, in the present review, we will focus on experimental and clinical evidence that indicates a role for ET-1 in diabetic vasculopathy and on the effects of current therapeutic approaches in diabetes on the vascular ET-1 system

The length and depth of real algebraic groups

Let $G$ be a connected real algebraic group. An unrefinable chain of $G$ is a chain of subgroups $G=G_0>G_1>...>G_t=1$ where each $G_i$ is a maximal connected real subgroup of $G_{i-1}$. The maximal (respectively, minimal) length of such an unrefinable chain is called the length (respectively, depth) of $G$. We give a precise formula for the length of $G$, which generalises results of Burness, Liebeck and Shalev on complex algebraic groups and also on compact Lie groups. If $G$ is simple then we bound the depth of $G$ above and below, and in many cases we compute the exact value. In particular, the depth of any simple $G$ is at most $9$

Epidemiology of autism spectrum disorder in Portugal: prevalence, clinical characterization, and medical conditions

The objective of this study was to estimate the prevalence of autistic spectrum disorder (ASD) and identify its clinical characterization, and medical conditions in a paediatric population in Portugal. A school survey was conducted in elementary schools, targeting 332,808 school-aged children in the mainland and 10,910 in the Azores islands. Referred children were directly assessed using the Diagnostic and Statistical Manual of Mental Disorders (4th edn), the Autism Diagnostic Interview-Revised, and the Childhood Autism Rating Scale. Clinical history and a laboratory investigation was performed. In parallel, a systematic multi-source search of children known to have autism was carried out in a restricted region. The global prevalence of ASD per 10,000 was 9.2 in mainland, and 15.6 in the Azores, with intriguing regional differences. A diversity of associated medical conditions was documented in 20%, with an unexpectedly high rate of mitochondrial respiratory chain disorders